JP7434103B2 - work equipment - Google Patents

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JP7434103B2
JP7434103B2 JP2020137176A JP2020137176A JP7434103B2 JP 7434103 B2 JP7434103 B2 JP 7434103B2 JP 2020137176 A JP2020137176 A JP 2020137176A JP 2020137176 A JP2020137176 A JP 2020137176A JP 7434103 B2 JP7434103 B2 JP 7434103B2
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threshold
running
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travel
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JP2022033076A (en
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祐史 福田
昂平 長尾
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Kubota Corp
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Description

本発明は、例えば、スキッドステアローダ、コンパクトトラックローダ、バックホー等の作業機に関するものである。 The present invention relates to working machines such as skid steer loaders, compact track loaders, and backhoes.

従来、作業機において減速及び増速を行う技術として特許文献１に示されているものがある。特許文献１の作業機は、エンジンを含む原動機と、原動機の動力により作動し且つ、作動油を吐出する油圧ポンプと、作動油の圧力に応じて第１速度と、第１速度よりも高速である第２速度とに速度が変更可能な走行油圧装置と、走行油圧装置に作用する作動油の圧力を変更可能な作動弁と、作動油の圧力を検出可能な測定装置と、を備え、作動弁は、測定装置から検出された作動油の圧力である検出圧力が、第２速度に対応する設定圧から所定圧以下に低下した場合に、走行油圧装置に作用する作動油の圧力を減圧して、走行油圧装置を第１速度に減速している。 BACKGROUND ART Conventionally, there is a technique disclosed in Patent Document 1 as a technique for decelerating and increasing speed in a working machine. The working machine of Patent Document 1 includes a prime mover including an engine, a hydraulic pump that operates by the power of the prime mover and discharges hydraulic oil, and a first speed and a higher speed than the first speed depending on the pressure of the hydraulic oil. A traveling hydraulic device capable of changing the speed to a certain second speed, an operating valve capable of changing the pressure of hydraulic oil acting on the traveling hydraulic device, and a measuring device capable of detecting the pressure of the hydraulic oil. The valve reduces the pressure of the hydraulic oil acting on the travel hydraulic system when the detected pressure, which is the pressure of the hydraulic oil detected by the measuring device, decreases from the set pressure corresponding to the second speed to a predetermined pressure or less. The travel hydraulic system is then decelerated to the first speed.

特開２０１７－１７９９２３号公報JP 2017-179923 Publication

特許文献１の作業機では、走行中に走行装置に供給される作動油の圧力が所定以上である場合に、第２速度から第１速度に自動減速することができる。しかしながら、作業機（走行装置）の走行状態（超信地旋回、信地旋回、直進）によって、不用意に減速をしてしまうことがある。
本発明は、上記したような従来技術の問題点を解決すべくなされたものであって、作業機の走行に応じてスムーズに減速を行うことができる作業機を提供することを目的とする。 In the working machine of Patent Document 1, when the pressure of hydraulic oil supplied to the traveling device while traveling is equal to or higher than a predetermined value, the work machine can automatically decelerate from the second speed to the first speed. However, depending on the running state of the work machine (traveling device) (super pivot turn, pivot turn, straight ahead), the speed may be inadvertently decelerated.
The present invention has been made to solve the problems of the prior art as described above, and an object of the present invention is to provide a working machine that can smoothly decelerate in accordance with the running of the working machine.

技術的課題を解決するために本発明が講じた技術的手段は、以下の通りである。
本発明の作業機は、機体と、前記機体の左側に設けられた左走行装置と、前記機体の右側に設けられた右走行装置と、前記左走行装置に動力を伝達可能な左走行モータと、前記右走行装置に動力を伝達可能な右走行モータと、前記左走行モータの第１回転数を検出する第１回転検出装置と、前記右走行モータの第２回転数を検出する第２回転検出装置と、前記左走行モータに作動油を供給する左走行ポンプと、前記右走行モータに作動油を供給する右走行ポンプと、少なくとも前記左走行ポンプ及び前記右走行ポンプのいずれかの操作を行う走行操作装置と、前記左走行モータ及び前記右走行モータが第１速度よりも高速な第２速度である場合に、前記第２速度から前記第１速度に自動的に減速する自動減速を行う制御装置と、を備え、前記制御装置は、前記第１回転検出装置が検出した前記第１回転数と前記第２回転検出装置が検出した前記第２回転数との回転差又は回転比率に基づいて、前記自動減速を行う減速閾値として、直進閾値を設定する。 The technical means taken by the present invention to solve the technical problems are as follows.
The working machine of the present invention includes a machine body, a left running device provided on the left side of the machine body, a right running device provided on the right side of the machine body, and a left running motor capable of transmitting power to the left running device. , a right travel motor capable of transmitting power to the right travel device, a first rotation detection device that detects a first rotation speed of the left travel motor, and a second rotation detection device that detects a second rotation speed of the right travel motor. a detection device, a left running pump that supplies hydraulic oil to the left running motor , a right running pump that supplies hydraulic oil to the right running motor, and at least one of the left running pump and the right running pump; a travel operating device that performs the operation ; and an automatic deceleration that automatically decelerates from the second speed to the first speed when the left travel motor and the right travel motor are at a second speed higher than the first speed. and a control device configured to detect a rotation difference or a rotation ratio between the first rotation speed detected by the first rotation detection device and the second rotation speed detected by the second rotation detection device. Based on this, a straight-ahead threshold is set as a deceleration threshold for performing the automatic deceleration.

本発明の一態様では、前記制御装置は、前記回転差が大きくなるにつれて前記直進閾値
を高く、前記回転差が小さくなるにつれて前記直進閾値を低く設定する。
また、本発明の一態様では、前記制御装置は、前記回転比率の差が大きくなるにつれて前記直進閾値を高く、前記回転比率の差が小さくなるにつれて前記直進閾値を低く設定する。 In one aspect of the present invention, the control device sets the straight-line threshold to be high as the rotational difference increases, and sets the straight-line threshold to be low as the rotational difference decreases.
Further, in one aspect of the present invention, the control device sets the straight-line threshold to be high as the difference in the rotation ratios becomes larger, and sets the straight-line threshold to be lower as the difference in the rotation ratios becomes smaller .

また、本発明の一態様では、前記作業機は、前記左走行ポンプと前記左走行モータとを接続する第１循環油路と、前記右走行ポンプと前記右走行モータとを接続する第２循環油路と、前記左走行モータの第１ポート側に設けられ且つ前記左走行モータの回転時の前記第１循環油路に作用する作動油の圧力を第１走行圧として検出する第１圧力検出装置と、前記左走行モータの第２ポート側に設けられ且つ前記左走行モータの回転時の前記第１循環油路に作用する作動油の圧力を第２走行圧として検出する第２圧力検出装置と、前記右走行モータの第３ポート側に設けられ且つ前記右走行モータの回転時の前記第２循環油路に作用する作動油の圧力を第３走行圧として検出する第３圧力検出装置と、前記右走行モータの第４ポート側に設けられ且つ前記右走行モータの回転時の前記第２循環油路に作用する作動油の圧力を第４走行圧として検出する第４圧力検出装置と、を備え、前記制御装置は、前記機体が直進であって前進する場合は、前記第１走行圧及び前記第３走行圧のいずれかが前記直進閾値以上であるときに、前記自動減速を行う。
また、本発明の他態様では、前記制御装置は、前記機体が直進であって前進する場合は、前記第１走行圧から前記第２走行圧を減算した第１差圧及び前記第３走行圧から前記第４走行圧を減算した第３差圧のいずれかが前記直進閾値以上であるときに、前記自動減速を行う。 Further, in one aspect of the present invention, the work machine includes a first circulation oil passage connecting the left running pump and the left running motor, and a second circulation oil passage connecting the right running pump and the right running motor. and a first pressure detection that detects, as a first running pressure, the pressure of hydraulic oil that is provided on the first port side of the left running motor and acts on the first circulation oil passage when the left running motor rotates. and a second pressure detection device that is provided on the second port side of the left travel motor and detects the pressure of hydraulic oil acting on the first circulation oil path when the left travel motor rotates as a second travel pressure. and a third pressure detection device that is provided on the third port side of the right travel motor and detects the pressure of the hydraulic oil acting on the second circulation oil path when the right travel motor rotates as a third travel pressure. , a fourth pressure detection device that is provided on the fourth port side of the right travel motor and detects the pressure of hydraulic oil acting on the second circulation oil passage when the right travel motor rotates as a fourth travel pressure; The control device performs the automatic deceleration when either the first running pressure or the third running pressure is equal to or higher than the straight-line threshold when the aircraft is moving straight ahead.
Further, in another aspect of the present invention, when the aircraft is traveling straight ahead, the control device includes a first differential pressure obtained by subtracting the second running pressure from the first running pressure and the third running pressure. The automatic deceleration is performed when any of the third differential pressures obtained by subtracting the fourth running pressure from the vehicle is equal to or greater than the straight-ahead threshold.

本発明によれば、作業機の走行に応じてスムーズに減速を行うことができる。 According to the present invention, it is possible to smoothly decelerate the work machine according to its travel.

作業機の油圧システム（油圧回路）を示す図である。It is a diagram showing a hydraulic system (hydraulic circuit) of a work machine. 走行操作部材の操作方向等を示す図である。FIG. 6 is a diagram illustrating the operation direction of the traveling operation member. 第１回転数ＬＭRPM、第１左閾値ＳＴ１L、第２左閾値ＳＴ２Lの関係を示す図である。It is a figure which shows the relationship between 1st rotation speed LMRPM , 1st left threshold value ST1 L , and 2nd left threshold value ST2 L. 第１回転数ＬＭRPM、第１右閾値ＳＴ１R、第２右閾値ＳＴ２Rの関係を示す図である。It is a figure which shows the relationship of 1st rotation speed LM RPM , 1st right threshold value ST1 R , and 2nd right threshold value ST2 R. 回転差ΔＭＰ、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sの関係を示す図である。FIG. 3 is a diagram showing the relationship between the rotational difference ΔMP, the first straight-line threshold SF1 S , and the second straight-line threshold SF2 S. 比率差ΔＤＰ、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２の関係を示す図である。FIG. 3 is a diagram showing the relationship among the ratio difference ΔDP, the first straight-line threshold SF1 S , and the second straight-line threshold SF2. 比率ΔＤＱ、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sの関係を示す図である。FIG. 3 is a diagram showing the relationship among the ratio ΔDQ, the first straight-line threshold SF1 S , and the second straight-line threshold SF2 S. 第１回転数ＬＭRPM、第２回転数ＲＭRPM、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sの関係を示す図である。It is a figure which shows the relationship of 1st rotation speed LM RPM , 2nd rotation speed RM RPM , 1st straight-line threshold SF1 S , and 2nd straight-line threshold SF2 S. 操作装置をジョイスティック等の電気的に作動する操作装置に変更した変形例を示す図である。FIG. 7 is a diagram showing a modification in which the operating device is changed to an electrically operated operating device such as a joystick. 作業機の一例であるトラックローダを示す側面図である。It is a side view showing a track loader which is an example of a work machine.

以下、本発明に係る作業機の油圧システム及びこの油圧システムを備えた作業機の好適な実施形態について、適宜図面を参照しながら説明する。
図９は、本発明に係る作業機の側面図を示している。図９では、作業機の一例として、コンパクトトラックローダを示している。但し、本発明に係る作業機はコンパクトトラックローダに限定されず、例えば、スキッドステアローダ等の他の種類のローダ作業機であってもよい。また、ローダ作業機以外の作業機であってもよい。 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a hydraulic system for a working machine according to the present invention and a working machine equipped with this hydraulic system will be described with reference to the drawings as appropriate.
FIG. 9 shows a side view of the working machine according to the present invention. In FIG. 9, a compact track loader is shown as an example of a work machine. However, the working machine according to the present invention is not limited to a compact track loader, but may be another type of loader working machine, such as a skid steer loader. Moreover, a work machine other than a loader work machine may be used.

作業機１は、図９に示すように、作業機１は、機体２と、キャビン３と、作業装置４と、一対の走行装置５Ｌ、５Ｒとを備えている。本発明の実施形態において、作業機１の運転席８に着座した運転者の前側（図９の左側）を前方、運転者の後側（図９の右側）を後方、運転者の左側（図９の手前側）を左方、運転者の右側（図９の奥側）を右方として説明する。また、前後の方向に直交する方向である水平方向を機体幅方向として説明する。機体２の中央部から右部或いは左部へ向かう方向を機体外方として説明する。言い換えれば、機体外方とは、機体幅方向であって、機体２から離れる方向である。機体外方とは反対の方向を、機体内方として説明する。言い換えれば、機体内方とは、機体幅方向であって、機体２に近づく方向である。 As shown in FIG. 9, the work machine 1 includes a body 2, a cabin 3, a work device 4, and a pair of traveling devices 5L and 5R. In the embodiment of the present invention, the front side of the driver seated in the driver's seat 8 of the work equipment 1 (left side in FIG. 9) is forward, the rear side of the driver (right side in FIG. 9) is rearward, and the left side of the driver (right side in FIG. 9) is the left side, and the driver's right side (the back side of FIG. 9) is the right side. In addition, the horizontal direction, which is a direction perpendicular to the front-rear direction, will be described as the fuselage width direction. The direction from the center of the fuselage 2 toward the right or left side will be described as the outward direction of the fuselage. In other words, the outside of the fuselage is the width direction of the fuselage, and is the direction away from the fuselage 2. The direction opposite to the outside of the fuselage will be described as inside the fuselage. In other words, the inside of the fuselage is the width direction of the fuselage, and the direction approaching the fuselage 2.

キャビン３は、機体２に搭載されている。このキャビン３には運転席８が設けられている。作業装置４は機体２に装着されている。一対の走行装置５Ｌ、５Ｒは、機体２の外側に設けられている。機体２内の後部には、原動機３２が搭載されている。
作業装置４は、ブーム１０と、作業具１１と、リフトリンク１２と、制御リンク１３と、ブームシリンダ１４と、バケットシリンダ１５とを有している。 Cabin 3 is mounted on fuselage 2. This cabin 3 is provided with a driver's seat 8. The working device 4 is attached to the machine body 2. The pair of traveling devices 5L and 5R are provided on the outside of the fuselage 2. A prime mover 32 is mounted at the rear inside the aircraft body 2.
The work device 4 includes a boom 10, a work implement 11, a lift link 12, a control link 13, a boom cylinder 14, and a bucket cylinder 15.

ブーム１０は、キャビン３の右側及び左側に上下揺動自在に設けられている。作業具１１は、例えば、バケットであって、当該バケット１１は、ブーム１０の先端部（前端部）に上下揺動自在に設けられている。リフトリンク１２及び制御リンク１３は、ブーム１０が上下揺動自在となるように、ブーム１０の基部（後部）を支持している。ブームシリンダ１４は、伸縮することによりブーム１０を昇降させる。バケットシリンダ１５は、伸縮することによりバケット１１を揺動させる。 The boom 10 is provided on the right and left sides of the cabin 3 so as to be vertically swingable. The work tool 11 is, for example, a bucket, and the bucket 11 is provided at the tip (front end) of the boom 10 so as to be vertically swingable. The lift link 12 and the control link 13 support the base (rear part) of the boom 10 so that the boom 10 can swing vertically. The boom cylinder 14 moves the boom 10 up and down by expanding and contracting. The bucket cylinder 15 swings the bucket 11 by expanding and contracting.

左側及び右側の各ブーム１０の前部同士は、異形の連結パイプで連結されている。各ブーム１０の基部（後部）同士は、円形の連結パイプで連結されている。
リフトリンク１２、制御リンク１３及びブームシリンダ１４は、左側と右側の各ブーム１０に対応して機体２の左側と右側にそれぞれ設けられている。
リフトリンク１２は、各ブーム１０の基部の後部に、縦向きに設けられている。このリフトリンク１２の上部（一端側）は、各ブーム１０の基部の後部寄りに枢支軸１６（第１枢支軸）を介して横軸回りに回転自在に枢支されている。また、リフトリンク１２の下部（他端側）は、機体２の後部寄りに枢支軸１７（第２枢支軸）を介して横軸回りに回転自在に枢支されている。第２枢支軸１７は、第１枢支軸１６の下方に設けられている。 The front parts of the left and right booms 10 are connected to each other by an irregularly shaped connecting pipe. The bases (rear parts) of each boom 10 are connected to each other by a circular connecting pipe.
The lift link 12, the control link 13, and the boom cylinder 14 are provided on the left and right sides of the fuselage 2, corresponding to the left and right booms 10, respectively.
The lift link 12 is provided vertically at the rear of the base of each boom 10. The upper part (one end side) of this lift link 12 is rotatably supported around a horizontal axis via a pivot shaft 16 (first pivot shaft) near the rear of the base of each boom 10. Further, the lower part (the other end side) of the lift link 12 is rotatably supported near the rear of the body 2 via a pivot shaft 17 (second pivot shaft) around a horizontal axis. The second pivot shaft 17 is provided below the first pivot shaft 16.

ブームシリンダ１４の上部は、枢支軸１８（第３枢支軸）を介して横軸回りに回転自在に枢支されている。第３枢支軸１８は、各ブーム１０の基部であって、当該基部の前部に設けられている。ブームシリンダ１４の下部は、枢支軸１９（第４枢支軸）を介して横軸回りに回転自在に枢支されている。第４枢支軸１９は、機体２の後部の下部寄りであって第３枢支軸１８の下方に設けられている。 The upper part of the boom cylinder 14 is rotatably supported around a horizontal axis via a pivot shaft 18 (third pivot shaft). The third pivot shaft 18 is provided at the base of each boom 10 and at the front of the base. The lower part of the boom cylinder 14 is rotatably supported around a horizontal axis via a pivot shaft 19 (fourth pivot shaft). The fourth pivot shaft 19 is provided near the bottom of the rear portion of the body 2 and below the third pivot shaft 18 .

制御リンク１３は、リフトリンク１２の前方に設けられている。この制御リンク１３の一端は、枢支軸２０（第５枢支軸）を介して横軸回りに回転自在に枢支されている。第５枢支軸２０は、機体２であって、リフトリンク１２の前方に対応する位置に設けられている。制御リンク１３の他端は、枢支軸２１（第６枢支軸）を介して横軸回りに回転自在に枢支されている。第６枢支軸２１は、ブーム１０であって、第２枢支軸１７の前方で且つ第２枢支軸１７の上方に設けられている。 The control link 13 is provided in front of the lift link 12. One end of this control link 13 is rotatably supported around a horizontal axis via a pivot shaft 20 (fifth pivot shaft). The fifth pivot shaft 20 is provided in the body 2 at a position corresponding to the front of the lift link 12. The other end of the control link 13 is rotatably supported around a horizontal axis via a pivot shaft 21 (sixth pivot shaft). The sixth pivot shaft 21 is provided in the boom 10 in front of and above the second pivot shaft 17 .

ブームシリンダ１４を伸縮することにより、リフトリンク１２及び制御リンク１３によって各ブーム１０の基部が支持されながら、各ブーム１０が第１枢支軸１６回りに上下揺動し、各ブーム１０の先端部が昇降する。制御リンク１３は、各ブーム１０の上下揺動に伴って第５枢支軸２０回りに上下揺動する。リフトリンク１２は、制御リンク１３の上下揺動に伴って第２枢支軸１７回りに前後揺動する。 By expanding and contracting the boom cylinder 14, each boom 10 swings up and down around the first pivot shaft 16 while the base of each boom 10 is supported by the lift link 12 and control link 13, and the tip of each boom 10 goes up and down. The control link 13 swings up and down about the fifth pivot shaft 20 as each boom 10 swings up and down. The lift link 12 swings back and forth around the second pivot shaft 17 as the control link 13 swings up and down.

ブーム１０の前部には、バケット１１の代わりに別の作業具が装着可能とされている。別の作業具としては、例えば、油圧圧砕機、油圧ブレーカ、アングルブルーム、アースオーガ、パレットフォーク、スイーパー、モア、スノウブロア等のアタッチメント（予備アタッチメント）である。
左側のブーム１０の前部には、接続部材５０が設けられている。接続部材５０は、予備アタッチメントに装備された油圧機器と、ブーム１０に設けられたパイプ等の第１管材とを接続する装置である。具体的には、接続部材５０の一端には、第１管材が接続可能で、他端には、予備アタッチメントの油圧機器に接続された第２管材が接続可能である。これにより、第１管材を流れる作動油は、第２管材を通過して油圧機器に供給される。 Another work tool can be attached to the front of the boom 10 instead of the bucket 11. Examples of other working tools include attachments (preliminary attachments) such as hydraulic crushers, hydraulic breakers, angle brooms, earth augers, pallet forks, sweepers, mowers, and snow blowers.
A connecting member 50 is provided at the front of the boom 10 on the left side. The connecting member 50 is a device that connects the hydraulic equipment installed on the preliminary attachment and a first pipe material such as a pipe provided on the boom 10. Specifically, a first pipe member can be connected to one end of the connecting member 50, and a second pipe member connected to a hydraulic device as a preliminary attachment can be connected to the other end. Thereby, the hydraulic oil flowing through the first pipe material passes through the second pipe material and is supplied to the hydraulic equipment.

バケットシリンダ１５は、各ブーム１０の前部寄りにそれぞれ配置されている。バケットシリンダ１５を伸縮することで、バケット１１が揺動される。
一対の走行装置５Ｌ、５Ｒのうち、走行装置５Ｌは機体２の左側に設けられ、走行装置５Ｒは機体２の右側に設けられている。一対の走行装置５Ｌ、５Ｒは、本実施形態ではクローラ型（セミクローラ型を含む）の走行装置が採用されている。なお、前輪及び後輪を有する車輪型の走行装置を採用してもよい。以下、説明の便宜上、走行装置５Ｌのことを左走行装置５Ｌ、走行装置５Ｒのことを右走行装置５Ｒということがある。 The bucket cylinders 15 are arranged near the front of each boom 10, respectively. By expanding and contracting the bucket cylinder 15, the bucket 11 is swung.
Of the pair of traveling devices 5L and 5R, the traveling device 5L is provided on the left side of the body 2, and the traveling device 5R is provided on the right side of the body 2. In this embodiment, the pair of traveling devices 5L and 5R are crawler type (including semi-crawler type) traveling devices. Note that a wheel-type traveling device having front wheels and rear wheels may be employed. Hereinafter, for convenience of explanation, the traveling device 5L may be referred to as the left traveling device 5L, and the traveling device 5R may be referred to as the right traveling device 5R.

原動機３２は、ディーゼルエンジン、ガソリンエンジン等の内燃機関、電動モータ等である。この実施形態では、原動機３２は、ディーゼルエンジンであるが限定はされない。
次に、作業機の油圧システムについて説明する。
図１に示すように、作業機の油圧システムは、第１油圧ポンプＰ１と、第２油圧ポンプＰ２とを備えている。第１油圧ポンプＰ１は、原動機３２の動力によって駆動するポンプであって、定容量型のギヤポンプによって構成されている。第１油圧ポンプＰ１は、タンク２２に貯留された作動油を吐出可能である。特に、第１油圧ポンプＰ１は、主に制御に用いる作動油を吐出する。説明の便宜上、作動油を貯留するタンク２２のことを作動油タンクということがある。また、第１油圧ポンプＰ１から吐出した作動油のうち、制御用として用いられる作動油のことをパイロット油、パイロット油の圧力のことをパイロット圧ということがある。 The prime mover 32 is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or the like. In this embodiment, prime mover 32 is, but is not limited to, a diesel engine.
Next, the hydraulic system of the work machine will be explained.
As shown in FIG. 1, the hydraulic system of the working machine includes a first hydraulic pump P1 and a second hydraulic pump P2. The first hydraulic pump P1 is a pump driven by the power of the prime mover 32, and is a constant displacement gear pump. The first hydraulic pump P1 can discharge hydraulic oil stored in the tank 22. In particular, the first hydraulic pump P1 discharges hydraulic oil mainly used for control. For convenience of explanation, the tank 22 that stores hydraulic oil may be referred to as a hydraulic oil tank. Further, among the hydraulic oil discharged from the first hydraulic pump P1, the hydraulic oil used for control may be referred to as pilot oil, and the pressure of the pilot oil may be referred to as pilot pressure.

第２油圧ポンプＰ２は、原動機３２の動力によって駆動するポンプであって、定容量型のギヤポンプによって構成されている。第２油圧ポンプＰ２は、タンク２２に貯留された作動油を吐出可能であって、例えば、作業系の油路に作動油を供給する。例えば、第２油圧ポンプＰ２は、ブーム１０を作動させるブームシリンダ１４、バケットを作動させるバケットシリンダ１５、予備油圧アクチュエータを作動させる予備油圧アクチュエータを制御する制御弁（流量制御弁）に作動油を供給する。 The second hydraulic pump P2 is a pump driven by the power of the prime mover 32, and is a constant displacement gear pump. The second hydraulic pump P2 is capable of discharging hydraulic oil stored in the tank 22, and supplies the hydraulic oil to, for example, an oil path of a working system. For example, the second hydraulic pump P2 supplies hydraulic oil to the boom cylinder 14 that operates the boom 10, the bucket cylinder 15 that operates the bucket, and the control valve (flow control valve) that controls the preliminary hydraulic actuator that operates the preliminary hydraulic actuator. do.

また、作業機の油圧システムは、一対の走行モータ３６Ｌ、３６Ｒと、一対の走行ポンプ５３Ｌ、５３Ｒと、を備えている。一対の走行モータ３６Ｌ、３６Ｒは、一対の走行装置５Ｌ、５Ｒに動力を伝達するモータである。一対の走行モータ３６Ｌ、３６Ｒのうち、一方の走行モータ３６Ｌは、走行装置（左走行装置）５Ｌに回転の動力を伝達し、他方の走行モータ３６Ｒは、走行装置（右走行装置）５Ｒに回転の動力を伝達する。 Further, the hydraulic system of the work machine includes a pair of travel motors 36L, 36R, and a pair of travel pumps 53L, 53R. The pair of travel motors 36L and 36R are motors that transmit power to the pair of travel devices 5L and 5R. Of the pair of travel motors 36L and 36R, one travel motor 36L transmits rotational power to the travel device (left travel device) 5L, and the other travel motor 36R rotates to the travel device (right travel device) 5R. transmits power.

一対の走行ポンプ５３Ｌ、５３Ｒは、原動機３２の動力によって駆動するポンプであって、例えば、斜板形可変容量アキシャルポンプである。一対の走行ポンプ５３Ｌ、５３Ｒは、駆動することによって、一対の走行モータ３６Ｌ、３６Ｒのそれぞれに作動油を供給する。一対の走行ポンプ５３Ｌ、５３Ｒのうち、一方の走行ポンプ５３Ｌは、走行ポンプ５３Ｌに作動油を供給し、他方の走行ポンプ５３Ｒは、走行ポンプ５３Ｒに作動油を供給する。 The pair of traveling pumps 53L and 53R are pumps driven by the power of the prime mover 32, and are, for example, swash plate type variable displacement axial pumps. When driven, the pair of travel pumps 53L, 53R supply hydraulic oil to each of the pair of travel motors 36L, 36R. Among the pair of traveling pumps 53L and 53R, one traveling pump 53L supplies hydraulic oil to the traveling pump 53L, and the other traveling pump 53R supplies hydraulic oil to the traveling pump 53R.

以下、説明の便宜上、走行ポンプ５３Ｌのことを左走行ポンプ５３Ｌ、走行ポンプ５３Ｒのことを右走行ポンプ５３Ｒ、走行モータ３６Ｌのことを左走行モータ３６Ｌ、走行モータ３６Ｒのことを右走行モータ３６Ｒということがある。
左走行ポンプ５３Ｌ及び右走行ポンプ５３Ｒには、第１油圧ポンプＰ１からの作動油（パイロット油）の圧力（パイロット圧）が作用する受圧部５３ａと受圧部５３ｂとを有している、受圧部５３ａ、５３ｂに作用するパイロット圧によって斜板の角度が変更される。斜版の角度を変更することによって、左走行ポンプ５３Ｌ及び右走行ポンプ５３Ｒの出力（作動油の吐出量）や作動油の吐出方向を変えることができる。 Hereinafter, for convenience of explanation, the traveling pump 53L will be referred to as the left traveling pump 53L, the traveling pump 53R will be referred to as the right traveling pump 53R, the traveling motor 36L will be referred to as the left traveling motor 36L, and the traveling motor 36R will be referred to as the right traveling motor 36R. Sometimes.
The left running pump 53L and the right running pump 53R have a pressure receiving part 53a and a pressure receiving part 53b to which the pressure (pilot pressure) of the hydraulic oil (pilot oil) from the first hydraulic pump P1 acts. The angle of the swash plate is changed by pilot pressure acting on 53a and 53b. By changing the angle of the slant plate, the output (discharge amount of hydraulic oil) and the discharge direction of hydraulic oil of the left traveling pump 53L and the right traveling pump 53R can be changed.

左走行ポンプ５３Ｌと左走行モータ３６Ｌとは、接続油路（第１循環油路）５７ｈによって接続され、左走行ポンプ５３Ｌが吐出した作動油が左走行モータ３６Ｌに供給される。右走行ポンプ５３Ｒと右走行モータ３６Ｒとは、接続油路（第２循環油路）５７ｉによって接続され、右走行ポンプ５３Ｒが吐出した作動油が右走行モータ３６Ｒに供給される。 The left travel pump 53L and the left travel motor 36L are connected by a connecting oil passage (first circulation oil passage) 57h, and the hydraulic oil discharged by the left travel pump 53L is supplied to the left travel motor 36L. The right traveling pump 53R and the right traveling motor 36R are connected by a connecting oil passage (second circulation oil passage) 57i, and the hydraulic oil discharged by the right traveling pump 53R is supplied to the right traveling motor 36R.

左走行モータ３６Ｌは、左走行ポンプ５３Ｌから吐出した作動油により回転が可能であり、作動油の流量によって、回転速度（回転数）を変更することができる。左走行モータ３６Ｌには、斜板切換シリンダ３７Ｌが接続され、当該斜板切換シリンダ３７Ｌを一方側或いは他方側に伸縮させることによっても左走行モータ３６Ｌの回転速度（回転数）を変更することができる。即ち、斜板切換シリンダ３７Ｌを収縮した場合には、左走行モータ３６Ｌの回転数は低速（第１速度）に設定され、斜板切換シリンダ３７Ｌを伸長した場合には、左走行モータ３６Ｌの回転数は高速（第２速度）に設定される。つまり、左走行モータ３６Ｌの回転数は、低速側である第１速度と、高速側である第２速度とに変更が可能である。 The left travel motor 36L can be rotated by hydraulic oil discharged from the left travel pump 53L, and the rotation speed (number of revolutions) can be changed depending on the flow rate of the hydraulic oil. A swash plate switching cylinder 37L is connected to the left travel motor 36L, and the rotational speed (rotation number) of the left travel motor 36L can also be changed by extending and contracting the swash plate switching cylinder 37L to one side or the other side. can. That is, when the swash plate switching cylinder 37L is retracted, the rotation speed of the left travel motor 36L is set to a low speed (first speed), and when the swash plate switching cylinder 37L is extended, the rotation speed of the left travel motor 36L is set to a low speed (first speed). The number is set to high speed (second speed). That is, the rotation speed of the left travel motor 36L can be changed between a first speed, which is a low speed, and a second speed, which is a high speed.

右走行モータ３６Ｒは、右走行ポンプ５３Ｒから吐出した作動油により回転が可能であり、作動油の流量によって、回転速度（回転数）を変更することができる。右走行モータ３６Ｒには、斜板切換シリンダ３７Ｒが接続され、当該斜板切換シリンダ３７Ｒを一方側或いは他方側に伸縮させることによっても右走行モータ３６Ｒの回転速度（回転数）を変更することができる。即ち、斜板切換シリンダ３７Ｒを収縮した場合には、右走行モータ３６Ｒの回転数は低速（第１速度）に設定され、斜板切換シリンダ３７Ｒを伸長した場合には、右走行モータ３６Ｒの回転数は高速（第２速度）に設定される。つまり、右走行モータ３６Ｒの回転数は、低速側である第１速度と、高速側である第２速度とに変更が可能である。 The right travel motor 36R can be rotated by hydraulic oil discharged from the right travel pump 53R, and the rotation speed (number of revolutions) can be changed depending on the flow rate of the hydraulic oil. A swash plate switching cylinder 37R is connected to the right traction motor 36R, and the rotational speed (rotation speed) of the right traction motor 36R can also be changed by extending or contracting the swash plate switching cylinder 37R to one side or the other. can. That is, when the swash plate switching cylinder 37R is retracted, the rotation speed of the right travel motor 36R is set to a low speed (first speed), and when the swash plate switching cylinder 37R is extended, the rotation speed of the right travel motor 36R is set to a low speed (first speed). The number is set to high speed (second speed). In other words, the rotation speed of the right travel motor 36R can be changed between a first speed, which is a low speed, and a second speed, which is a high speed.

図１に示すように、作業機の油圧システムは、走行切換弁３４を備えている。走行切換弁３４は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）の回転速度（回転数）を第１速度にする第１状態と、第２速度にする第２状態とに切換可能である。走行切換弁３４は、第１切換弁７１Ｌ、７１Ｒと、第２切換弁７２と、を有している。
第１切換弁７１Ｌは、左走行モータ３６Ｌの斜板切換シリンダ３７Ｌに油路を介して接続されていて、第１位置７１Ｌ１及び第２位置７１Ｌ２に切り換わる二位置切換弁である。第１切換弁７１Ｌは、第１位置７１Ｌ１である場合、斜板切換シリンダ３７Ｌを収縮し、第２位置７１Ｌ２である場合、斜板切換シリンダ３７Ｌを伸長する。 As shown in FIG. 1, the hydraulic system of the working machine includes a travel switching valve 34. The travel switching valve 34 can be switched between a first state in which the rotational speed (rotational speed) of the travel motors (left travel motor 36L, right travel motor 36R) is set at a first speed, and a second state in which the rotation speed is set at a second speed. be. The travel switching valve 34 includes first switching valves 71L, 71R and a second switching valve 72.
The first switching valve 71L is a two-position switching valve that is connected to the swash plate switching cylinder 37L of the left traveling motor 36L via an oil passage and switches to a first position 71L1 and a second position 71L2. The first switching valve 71L contracts the swash plate switching cylinder 37L when it is in the first position 71L1, and extends the swash plate switching cylinder 37L when it is in the second position 71L2.

第１切換弁７１Ｒは、右走行モータ３６Ｒの斜板切換シリンダ３７Ｒに油路を介して接続されていて、第１位置７１Ｒ１及び第２位置７１Ｒ２に切り換わる二位置切換弁である。第１切換弁７１Ｒは、第１位置７１Ｒ１である場合、斜板切換シリンダ３７Ｒを収縮し、第２位置７１Ｒ２である場合、斜板切換シリンダ３７Ｒを伸長する。
第２切換弁７２は、第１切換弁７１Ｌ及び第１切換弁７１Ｒを切り換える電磁弁であって、励磁により第１位置７２ａと第２位置７２ｂとに切り換え可能な二位置切換弁である。第２切換弁７２、第１切換弁７１Ｌ及び第１切換弁７１Ｒは、油路４１により接続されている。第２切換弁７２は、第１位置７２ａである場合に第１切換弁７１Ｌ及び第１切換弁７１Ｒを第１位置７１Ｌ１、７１Ｒ１に切り換え、第２位置７２ｂである場合に第１切換弁７１Ｌ及び第１切換弁７１Ｒを第２位置７１Ｌ２、７１Ｒ２に切り換える。 The first switching valve 71R is a two-position switching valve that is connected to the swash plate switching cylinder 37R of the right travel motor 36R via an oil passage and switches to a first position 71R1 and a second position 71R2. The first switching valve 71R contracts the swash plate switching cylinder 37R when in the first position 71R1, and extends the swash plate switching cylinder 37R when in the second position 71R2.
The second switching valve 72 is a solenoid valve that switches between the first switching valve 71L and the first switching valve 71R, and is a two-position switching valve that can be switched between a first position 72a and a second position 72b by excitation. The second switching valve 72, the first switching valve 71L, and the first switching valve 71R are connected by an oil passage 41. The second switching valve 72 switches the first switching valve 71L and the first switching valve 71R to the first positions 71L1 and 71R1 when the second switching valve 72 is in the first position 72a, and switches the first switching valve 71L and the first switching valve 71R to the first position 71L1 and 71R1 when the second switching valve 72 is in the second position 72b. The first switching valve 71R is switched to the second position 71L2, 71R2.

つまり、第２切換弁７２が第１位置７２ａ、第１切換弁７１Ｌが第１位置７１Ｌ１、第１切換弁７１Ｒが第１位置７１Ｒ１である場合に、走行切換弁３４は第１状態になり、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）の回転速度を第１速度にする。第２切換弁７２が第２位置７２ｂ、第１切換弁７１Ｌが第２位置７１Ｌ２、第１切換弁７１Ｒが第２位置７１Ｒ２である場合に、走行切換弁３４は第２状態になり、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）の回転速度を第２速度にする。 That is, when the second switching valve 72 is in the first position 72a, the first switching valve 71L is in the first position 71L1, and the first switching valve 71R is in the first position 71R1, the travel switching valve 34 is in the first state, The rotation speed of the travel motors (left travel motor 36L, right travel motor 36R) is set to the first speed. When the second switching valve 72 is in the second position 72b, the first switching valve 71L is in the second position 71L2, and the first switching valve 71R is in the second position 71R2, the travel switching valve 34 is in the second state, and the travel motor The rotational speeds of (left travel motor 36L, right travel motor 36R) are set to the second speed.

したがって、走行切換弁３４によって、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を低速側である第１速度と、高速側である第２速度とに切り換えることができる。
操作装置（走行操作装置）５４は、走行操作部材５９を操作したときに、走行ポンプ（左走行ポンプ５３Ｌ、右走行ポンプ５３Ｒ）の受圧部５３ａ、５３ｂに作動油を作用させる装置であり、走行ポンプの斜板の角度（斜板角度）を変更可能である。操作装置５４は、走行操作部材５９と、複数の操作弁５５とを含んでいる。 Therefore, the travel switching valve 34 can switch the travel motors (left travel motor 36L, right travel motor 36R) between a first speed, which is a low speed, and a second speed, which is a high speed.
The operating device (travel operating device) 54 is a device that applies hydraulic oil to the pressure receiving parts 53a and 53b of the traveling pumps (left traveling pump 53L, right traveling pump 53R) when the traveling operation member 59 is operated. The angle of the swash plate of the pump (swash plate angle) can be changed. The operating device 54 includes a travel operating member 59 and a plurality of operating valves 55.

走行操作部材５９は、操作弁５５に支持され、左右方向（機体幅方向）又は前後方向に揺動する操作レバーである。即ち、走行操作部材５９は、中立位置Ｎを基準とすると、中立位置Ｎから右方及び左方に操作可能であると共に、中立位置Ｎから前方及び後方に操作可能である。言い換えれば、走行操作部材５９は、中立位置Ｎを基準に少なくとも４方向に揺動することが可能である。尚、説明の便宜上、前方及び後方の双方向、即ち、前後方向のことを第１方向という。また、右方及び左方の双方向、即ち、左右方向（機体幅方向）のことを第２方向ということがある。 The traveling operation member 59 is an operation lever that is supported by the operation valve 55 and swings in the left-right direction (body width direction) or the front-rear direction. That is, the traveling operation member 59 can be operated rightward and leftward from the neutral position N, and can be operated forward and backward from the neutral position N. In other words, the traveling operation member 59 can swing in at least four directions with the neutral position N as a reference. For convenience of explanation, the forward and backward directions, that is, the front-rear direction will be referred to as the first direction. In addition, the right and left directions, that is, the left-right direction (body width direction) may be referred to as a second direction.

また、複数の操作弁５５は、共通、即ち、１本の走行操作部材５９によって操作される。複数の操作弁５５は、走行操作部材５９の揺動に基づいて作動する。複数の操作弁５５には、吐出油路４０が接続され、当該吐出油路４０を介して、第１油圧ポンプＰ１からの作動油（パイロット油）が供給可能である。複数の操作弁５５は、操作弁５５Ａ、操作弁５５Ｂ、操作弁５５Ｃ及び操作弁５５Ｄである。 Further, the plurality of operation valves 55 are operated in common, that is, by one traveling operation member 59. The plurality of operation valves 55 are operated based on the swing of the traveling operation member 59. A discharge oil passage 40 is connected to the plurality of operation valves 55, and hydraulic oil (pilot oil) from the first hydraulic pump P1 can be supplied through the discharge oil passage 40. The plurality of operating valves 55 are an operating valve 55A, an operating valve 55B, an operating valve 55C, and an operating valve 55D.

操作弁５５Ａは、前後方向（第１方向）のうち、走行操作部材５９を前方（一方）に揺動した場合（前操作した場合）に、前操作の操作量（操作）に応じて出力する作動油の圧力が変化する。操作弁５５Ｂは、前後方向（第１方向）のうち、走行操作部材５９を後方（他方）に揺動した場合（後操作した場合）に、後操作の操作量（操作）に応じて出力する作動油の圧力が変化する。左右方向（第２方向）のうち、操作弁５５Ｃは、走行操作部材５９を右方（一方）に揺動した場合（右操作した場合）に、右操作の操作量（操作）に応じて出力する作動油の圧力が変化する。操作弁５５Ｄは、左右方向（第２方向）のうち、走行操作部材５９を、左方（他方）に揺動した場合（左操作した場合）に、左操作の操作量（操作）に応じて出力する作動油の圧力が変化する。 The operation valve 55A outputs an output according to the amount of operation (operation) of the previous operation when the traveling operation member 59 is swung forward (on one side) in the front-rear direction (first direction) (when the front operation is performed). Hydraulic oil pressure changes. The operation valve 55B outputs an output according to the amount of operation (operation) of the rear operation when the traveling operation member 59 is swung backward (on the other side) in the front-rear direction (first direction) (when the rear operation is performed). Hydraulic oil pressure changes. In the left-right direction (second direction), when the traveling operation member 59 is swung to the right (one side) (when the right operation is performed), the operation valve 55C outputs an output according to the operation amount (operation) of the right operation. The pressure of the hydraulic fluid changes. When the travel operation member 59 is swung to the left (the other side) in the left-right direction (second direction) (when operated to the left), the operation valve 55D is operated according to the operation amount (operation) of the left operation. The pressure of the output hydraulic oil changes.

複数の操作弁５５と、走行ポンプ（左走行ポンプ５３Ｌ，右走行ポンプ５３Ｒ）とは、走行油路４５によって接続されている。言い換えれば、走行ポンプ（左走行ポンプ５３Ｌ，右走行ポンプ５３Ｒ）は、操作弁５５（操作弁５５Ａ、操作弁５５Ｂ、操作弁５５Ｃ、操作弁５５Ｄ）から出力した作動油によって作動可能な油圧機器である。
走行油路４５は、第１走行油路４５ａ、第２走行油路４５ｂ、第３走行油路４５ｃ、第４走行油路４５ｄと、第５走行油路４５ｅとを有している。第１走行油路４５ａは、左走行ポンプ５３Ｌの受圧部（第１受圧部）５３ａに接続された油路であり、走行操作部材５９を操作したときに受圧部（第１受圧部）５３ａに作用する作動油を通過させる油路である。第２走行油路４５ｂは、左走行ポンプ５３Ｌの受圧部（第２受圧部）５３ｂに接続され油路であり、走行操作部材５９を操作したときに受圧部（第２受圧部）５３ｂに作用する作動油を通過させる油路である。第３走行油路４５ｃは、右走行ポンプ５３Ｒの受圧部（第３受圧部）５３ａに接続され油路であり、走行操作部材５９を操作したときに受圧部（第３受圧部）５３ａに作用する作動油を通過させる油路である。第４走行油路４５ｄは、右走行ポンプ５３Ｒの受圧部（第４受圧部）５３ｂに接続され油路であり、走行操作部材５９を操作したときに受圧部（第４受圧部）５３ｂに作用する作動油を通過させる油路である。第５走行油路４５ｅは、操作弁５５、第１走行油路４５ａ、第２走行油路４５ｂ、第３走行油路４５ｃ、第４走行油路４５ｄを接続する油路である。 The plurality of operation valves 55 and the running pumps (left running pump 53L, right running pump 53R) are connected by running oil passage 45. In other words, the running pumps (left running pump 53L, right running pump 53R) are hydraulic devices that can be operated by hydraulic fluid output from the operating valves 55 (operating valves 55A, operating valves 55B, operating valves 55C, operating valves 55D). be.
The oil passage 45 includes a first oil passage 45a, a second oil passage 45b, a third oil passage 45c, a fourth oil passage 45d, and a fifth oil passage 45e. The first traveling oil passage 45a is an oil passage connected to the pressure receiving part (first pressure receiving part) 53a of the left traveling pump 53L, and when the traveling operation member 59 is operated, the first traveling oil passage 45a is an oil passage connected to the pressure receiving part (first pressure receiving part) 53a of the left traveling pump 53L. This is an oil passage through which working hydraulic oil passes. The second traveling oil passage 45b is an oil passage connected to the pressure receiving part (second pressure receiving part) 53b of the left traveling pump 53L, and acts on the pressure receiving part (second pressure receiving part) 53b when the traveling operation member 59 is operated. This is an oil passage that allows hydraulic oil to pass through. The third traveling oil passage 45c is an oil passage connected to the pressure receiving part (third pressure receiving part) 53a of the right traveling pump 53R, and acts on the pressure receiving part (third pressure receiving part) 53a when the traveling operation member 59 is operated. This is an oil passage that allows hydraulic oil to pass through. The fourth traveling oil passage 45d is an oil passage connected to the pressure receiving part (fourth pressure receiving part) 53b of the right traveling pump 53R, and acts on the pressure receiving part (fourth pressure receiving part) 53b when the traveling operation member 59 is operated. This is an oil passage that allows hydraulic oil to pass through. The fifth oil passage 45e is an oil passage that connects the operation valve 55, the first oil passage 45a, the second oil passage 45b, the third oil passage 45c, and the fourth oil passage 45d.

第５走行油路４５ｅには、複数の高圧選択弁４７ａ、４７ｂ、４７ｃ、４７ｄが設けられている。複数の高圧選択弁４７ａ、４７ｂ、４７ｃ、４７ｄは、第１走行油路４５ａ、第２走行油路４５ｂ、第３走行油路４５ｃ及び第４走行油路４５ｄに接続され、作動油の圧力（パイロット圧）が高い方に作動油を流す。
走行操作部材５９を前方（図１、図２では矢印Ａ１方向）に揺動させると、操作弁５５Ａが操作されて該操作弁５５Ａからパイロット圧が出力される。このパイロット圧は、第１走行油路４５ａを介して左走行ポンプ５３Ｌの受圧部５３ａに作用すると共に第３走行油路４５ｃを介して右走行ポンプ５３Ｒの受圧部５３ａに作用する。これにより、左走行ポンプ５３Ｌ及び右走行ポンプ５３Ｒの斜板角度が変更され、左走行モータ３６Ｌ及び右走行モータ３６Ｒが正転(前進回転）して作業機１が前方に直進する。 A plurality of high-pressure selection valves 47a, 47b, 47c, and 47d are provided in the fifth oil passage 45e. The plurality of high pressure selection valves 47a, 47b, 47c, and 47d are connected to a first running oil passage 45a, a second running oil passage 45b, a third running oil passage 45c, and a fourth running oil passage 45d, and are connected to the hydraulic oil pressure ( Flow the hydraulic oil to the side with higher pilot pressure.
When the traveling operation member 59 is swung forward (in the direction of arrow A1 in FIGS. 1 and 2), the operating valve 55A is operated and pilot pressure is output from the operating valve 55A. This pilot pressure acts on the pressure receiving part 53a of the left running pump 53L via the first running oil passage 45a, and acts on the pressure receiving part 53a of the right running pump 53R via the third running oil passage 45c. As a result, the swash plate angles of the left traveling pump 53L and the right traveling pump 53R are changed, the left traveling motor 36L and the right traveling motor 36R rotate normally (forward rotation), and the work implement 1 moves straight forward.

また、走行操作部材５９を後方（図１、図２では矢示Ａ２方向）に揺動させると、操作弁５５Ｂが操作されて該操作弁５５Ｂからパイロット圧が出力される。このパイロット圧は、第２走行油路４５ｂを介して左走行ポンプ５３Ｌの受圧部５３ｂに作用すると共に第４走行油路４５ｄを介して右走行ポンプ５３Ｒの受圧部５３ｂに作用する。これにより、左走行ポンプ５３Ｌ及び右走行ポンプ５３Ｒの斜板角度が変更され、左走行モータ３６Ｌ及び右走行モータ３６Ｒが逆転（後進回転）して作業機１が後方に直進する。 Further, when the traveling operation member 59 is swung rearward (in the direction of arrow A2 in FIGS. 1 and 2), the operation valve 55B is operated and pilot pressure is output from the operation valve 55B. This pilot pressure acts on the pressure receiving part 53b of the left running pump 53L via the second running oil passage 45b, and acts on the pressure receiving part 53b of the right running pump 53R via the fourth running oil passage 45d. As a result, the swash plate angles of the left travel pump 53L and the right travel pump 53R are changed, the left travel motor 36L and the right travel motor 36R are reversed (reverse rotation), and the work implement 1 moves straight backward.

また、走行操作部材５９を右方（図１、図２では矢示Ａ３方向）に揺動させると、操作弁５５Ｃが操作されて該操作弁５５Ｃからパイロット圧が出力される。このパイロット圧は、第１走行油路４５ａを介して左走行ポンプ５３Ｌの受圧部５３ａに作用すると共に第４走行油路４５ｄを介して右走行ポンプ５３Ｒの受圧部５３ｂに作用する。これにより、左走行ポンプ５３Ｌ及び右走行ポンプ５３Ｒの斜板角度が変更され、左走行モータ３６Ｌが正転し且つ右走行モータ３６Ｒが逆転して作業機１が右側にスピンターン（超信地旋回）する。 Further, when the traveling operation member 59 is swung to the right (in the direction of arrow A3 in FIGS. 1 and 2), the operating valve 55C is operated and pilot pressure is output from the operating valve 55C. This pilot pressure acts on the pressure receiving part 53a of the left running pump 53L via the first running oil passage 45a, and acts on the pressure receiving part 53b of the right running pump 53R via the fourth running oil passage 45d. As a result, the swash plate angles of the left travel pump 53L and right travel pump 53R are changed, the left travel motor 36L rotates in the normal direction, and the right travel motor 36R rotates in the reverse direction, causing the work equipment 1 to spin turn to the right. )do.

また、走行操作部材５９を左方（図１、図２では矢示Ａ４方向）に揺動させると、操作弁５５Ｄが操作されて該操作弁５５Ｄからパイロット圧が出力される。このパイロット圧は第３走行油路４５ｃを介して右走行ポンプ５３Ｒの受圧部５３ａに作用すると共に第２走行油路４５ｂを介して左走行ポンプ５３Ｌの受圧部５３ｂに作用する。これにより、左走行ポンプ５３Ｌ及び右走行ポンプ５３Ｒの斜板角度が変更され、左走行モータ３６Ｌが逆転し且つ右走行モータ３６Ｒが正転して作業機１が左側にスピンターン（超信地旋回）する。 Further, when the traveling operation member 59 is swung to the left (in the direction of arrow A4 in FIGS. 1 and 2), the operating valve 55D is operated and pilot pressure is output from the operating valve 55D. This pilot pressure acts on the pressure receiving part 53a of the right running pump 53R via the third running oil passage 45c, and acts on the pressure receiving part 53b of the left running pump 53L via the second running oil passage 45b. As a result, the swash plate angles of the left travel pump 53L and the right travel pump 53R are changed, the left travel motor 36L is reversed, the right travel motor 36R is rotated forward, and the work equipment 1 is rotated to the left. )do.

また、走行操作部材５９を斜め方向（図２では矢示Ａ５方向）に揺動させると、受圧部５３ａと受圧部５３ｂとに作用するパイロット圧の差圧によって、左走行モータ３６Ｌ及び右走行モータ３６Ｒの回転方向及び回転速度が決定され、作業機１が前進又は後進しながら右へ信地旋回又は左へ信地旋回する。
すなわち、走行操作部材５９を左斜め前方に揺動操作すると該走行操作部材５９の揺動角度に対応した速度で作業機１が前進しながら左旋回し、走行操作部材５９を右斜め前方に揺動操作すると該走行操作部材５９の揺動角度に対応した速度で作業機１が前進しながら右旋回し、走行操作部材５９を左斜め後方に揺動操作すると該走行操作部材５９の揺動角度に対応した速度で作業機１が後進しながら左旋回し、走行操作部材５９を右斜め後方に揺動操作すると該走行操作部材５９の揺動角度に対応した速度で作業機１が後進しながら右旋回する。 Furthermore, when the traveling operation member 59 is swung in the diagonal direction (direction of arrow A5 in FIG. 2), the differential pressure between the pilot pressures acting on the pressure receiving portion 53a and the pressure receiving portion 53b causes the left traveling motor 36L and the right traveling motor to The rotational direction and rotational speed of 36R are determined, and the working machine 1 rotates to the right or to the left while moving forward or backward.
That is, when the traveling operating member 59 is operated to swing diagonally forward to the left, the work implement 1 moves forward at a speed corresponding to the swinging angle of the traveling operating member 59 and turns to the left, and the traveling operating member 59 is swung diagonally forward to the right. When operated, the work implement 1 moves forward and turns to the right at a speed corresponding to the swing angle of the travel operation member 59, and when the travel operation member 59 is swung diagonally backward to the left, the work implement 1 rotates to the right at a speed corresponding to the swing angle of the travel operation member 59. When the work equipment 1 turns to the left while moving backward at a corresponding speed and swings the travel operation member 59 diagonally backward to the right, the work equipment 1 turns to the right while moving backward at a speed corresponding to the swing angle of the travel operation member 59. Turn.

図１に示すように、作業機１は、制御装置６０を備えている。制御装置６０は、作業機１の様々な制御を行うもので、ＣＰＵ、ＭＰＵ等の半導体、電気電子回路等から構成されている。制御装置６０には、モードスイッチ６６と、速度切換スイッチ６７、複数の回転検出装置６８とが接続されている。
モードスイッチ６６は、自動減速を有効又は無効に切り換えるスイッチである。例えば、モードスイッチ６６は、ＯＮ／ＯＦＦに切り換え可能なスイッチであり、ＯＮである場合に自動減速を有効に切り換え、ＯＦＦである場合には自動減速を無効に切り換える。 As shown in FIG. 1, the work machine 1 includes a control device 60. The control device 60 performs various controls on the work machine 1, and is composed of semiconductors such as a CPU and MPU, electric and electronic circuits, and the like. A mode switch 66 , a speed changeover switch 67 , and a plurality of rotation detection devices 68 are connected to the control device 60 .
The mode switch 66 is a switch that enables or disables automatic deceleration. For example, the mode switch 66 is a switch that can be switched ON/OFF, and when it is ON, it enables automatic deceleration, and when it is OFF, it disables automatic deceleration.

速度切換スイッチ６７は、運転席８の近傍に設けられ、運転者（オペレータ）が操作可能である。速度切換スイッチ６７は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第１速度及び第２速度のいずれかに手動で切り換えることができるスイッチである。例えば、速度切換スイッチ６７は、第１速度側と第２速度側とに切り換えるシーソスイッチであり、第１速度側から第２速度側とに切り換える増速操作と、第２速度から第１速度に切り換える減速操作とを行うことができる。 The speed changeover switch 67 is provided near the driver's seat 8 and can be operated by a driver (operator). The speed changeover switch 67 is a switch that can manually switch the travel motors (left travel motor 36L, right travel motor 36R) to either the first speed or the second speed. For example, the speed changeover switch 67 is a seesaw switch that switches between a first speed side and a second speed side, and a speed increase operation that changes from the first speed side to the second speed side, and a speed increase operation that changes from the second speed side to the first speed side. It is possible to perform switching and deceleration operations.

複数の回転検出装置６８は、回転数を検出するセンサ等で構成されていて、現在の走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）の回転数であるモータ回転数を検出する。複数の回転検出装置６８は、左走行モータ３６Ｌのモータ回転数（第１回転数）を検出する第１回転検出装置６８ａと、右走行モータ３６Ｒのモータ回転数（第２回転数）を検出する第２回転検出装置６８ｂとを有している。 The plurality of rotation detection devices 68 are composed of sensors and the like that detect rotation speed, and detect the motor rotation speed which is the current rotation speed of the travel motors (left travel motor 36L, right travel motor 36R). The plurality of rotation detection devices 68 include a first rotation detection device 68a that detects the motor rotation speed (first rotation speed) of the left travel motor 36L, and a first rotation detection device 68a that detects the motor rotation speed (second rotation speed) of the right travel motor 36R. It has a second rotation detection device 68b.

制御装置６０は、自動減速部６１を備えている。自動減速部６１は、制御装置６０に設けられた電気電子回路等、当該制御装置６０に格納されたプログラム等である。
自動減速部６１は、自動減速が有効である場合には自動減速制御を行い、自動減速が無効である場合には自動減速制御を行わない。
自動減速制御では、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度である場合において所定の条件（自動減速条件）を満たしたときに、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第２速度から第１速度に自動的に切り換える。自動減速制御では、少なくとも走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度である状況において、自動減速条件を満たすと、制御装置６０は、第２切換弁７２のソレノイドを消磁することで、当該第２切換弁７２を第２位置７２ｂから第１位置７２ａに切り換えることにより、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第２速度から第１速度に減速する。つまり、制御装置６０は、自動減速制御において、自動減速を行う際は、左走行モータ３６Ｌと右走行モータ３６Ｒとの両方を、第２速度から第１速度に減速する。 The control device 60 includes an automatic deceleration section 61. The automatic deceleration unit 61 is an electric/electronic circuit provided in the control device 60, a program stored in the control device 60, or the like.
The automatic deceleration unit 61 performs automatic deceleration control when automatic deceleration is valid, and does not perform automatic deceleration control when automatic deceleration is invalid.
In automatic deceleration control, when the travel motors (left travel motor 36L, right travel motor 36R) are at the second speed and a predetermined condition (automatic deceleration condition) is satisfied, the travel motors (left travel motor 36L, right travel motor 36R) are set to the second speed. The motor 36R) is automatically switched from the second speed to the first speed. In the automatic deceleration control, when the automatic deceleration condition is satisfied in a situation where at least the travel motors (left travel motor 36L, right travel motor 36R) are at the second speed, the control device 60 demagnetizes the solenoid of the second switching valve 72. By switching the second switching valve 72 from the second position 72b to the first position 72a, the travel motors (left travel motor 36L, right travel motor 36R) are decelerated from the second speed to the first speed. That is, in the automatic deceleration control, when performing automatic deceleration, the control device 60 decelerates both the left traveling motor 36L and the right traveling motor 36R from the second speed to the first speed.

なお、自動減速部６１は、自動減速を行った後、復帰条件を満たすと、第２切換弁７２のソレノイドを励磁することで、当該第２切換弁７２を第１位置７２ａから第２位置７２ｂに切り換えることにより、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第１速度から第２速度に増速、即ち、走行モータの速度を復帰させる。つまり、制御装置６０は、第１速度から第２速度に復帰する場合は、左走行モータ３６Ｌと右走行モータ３６Ｒとの両方を、第１速度から第２速度に増速する。 Note that when the automatic deceleration unit 61 satisfies the return conditions after automatic deceleration, the automatic deceleration unit 61 energizes the solenoid of the second switching valve 72 to move the second switching valve 72 from the first position 72a to the second position 72b. By switching to , the speed of the travel motors (left travel motor 36L, right travel motor 36R) is increased from the first speed to the second speed, that is, the speed of the travel motor is restored. That is, when returning from the first speed to the second speed, the control device 60 increases the speed of both the left travel motor 36L and the right travel motor 36R from the first speed to the second speed.

制御装置６０は、自動減速が無効である場合に、速度切換スイッチ６７の操作に応じて、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第１速度及び第２速度のいずれかに切り換える手動切換制御を行う。手動切換制御では、速度切換スイッチ６７が第１速度側に切り換えられた場合は、第２切換弁７２のソレノイドを消磁することで、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第１速度にする。また、手動切換制御では、速度切換スイッチ６７が第２速度側に切り換えられた場合は、第２切換弁７２のソレノイドを励磁することで、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）を第２速度にする。なお、制御装置６０は、自動減速が有効である場合も速度切換スイッチ６７の操作を介入することによって、手動切換制御により、第１速度及び第２速度のいずれかにも切り換えてもよい。 When automatic deceleration is disabled, the control device 60 switches the travel motors (left travel motor 36L, right travel motor 36R) to either the first speed or the second speed in accordance with the operation of the speed changeover switch 67. Performs manual switching control. In manual switching control, when the speed selector switch 67 is switched to the first speed side, the solenoid of the second switching valve 72 is demagnetized to switch the travel motors (left travel motor 36L, right travel motor 36R) to the first speed side. speed. In addition, in manual switching control, when the speed selector switch 67 is switched to the second speed side, the solenoid of the second switching valve 72 is energized to control the travel motors (left travel motor 36L, right travel motor 36R). Set to second speed. Note that even when automatic deceleration is effective, the control device 60 may switch to either the first speed or the second speed by manual switching control by operating the speed changeover switch 67.

さて、制御装置６０には、原動機３２の目標回転数を設定するアクセル６５が接続されている。アクセル６５は、運転席８の近傍に設けられている。アクセル６５は、揺動自在に支持されたアクセルレバー、揺動自在に支持されたアクセルペダル、回転自在に支持されたアクセルボリューム、スライド自在に支持されたアクセルスライダー等である。なお、アクセル６５は、上述した例に限定されない。また、制御装置６０には、原動機３２の実回転数を検出する第３回転検出装置６９が接続されている。第３回転検出装置６９によって、制御装置６０は、原動機３２の実回転数を把握することができる。制御装置６０は、アクセル６５の操作量に基づいて、目標回転数を設定して、設定した目標回転数になるように実回転数を制御する。 Now, an accelerator 65 for setting a target rotation speed of the prime mover 32 is connected to the control device 60 . The accelerator 65 is provided near the driver's seat 8. The accelerator 65 includes a swingably supported accelerator lever, a swingably supported accelerator pedal, a rotatably supported accelerator volume, a slidably supported accelerator slider, and the like. Note that the accelerator 65 is not limited to the example described above. Further, a third rotation detection device 69 that detects the actual rotation speed of the prime mover 32 is connected to the control device 60 . The third rotation detection device 69 allows the control device 60 to grasp the actual rotation speed of the prime mover 32 . The control device 60 sets a target rotation speed based on the amount of operation of the accelerator 65, and controls the actual rotation speed to reach the set target rotation speed.

さて、制御装置６０は、循環油路５７ｈ、５７ｉの圧力に基づいて自動減速を行う。循環油路５７ｈ、５７ｉには、複数の圧検出装置８０が接続されている。複数の圧検出装置８０は、第１圧力検出装置８０ａ、第２圧力検出装置８０ｂ、第３圧力検出装置８０ｃ、第４圧力検出装置８０ｄを含んでいる。第１圧力検出装置８０ａは、循環油路５７ｈにおいて、左走行モータ３６Ｌの第１ポートＰ１１側に設けられ、第１ポートＰ１１側の圧力を第１走行圧Ｖ１として検出する。第２圧力検出装置８０ｂは、循環油路５７ｈにおいて、左走行モータ３６Ｌの第２ポートＰ１２側に設けられ、第２ポートＰ１２側の圧力を第２走行圧Ｖ２として検出する。第３圧力検出装置８０ｃは、循環油路５７ｉにおいて、右走行モータ３６Ｒの第３ポートＰ１３側に設けられ、第３ポートＰ１３側の圧力を第３走行圧Ｖ３として検出する。第４圧力検出装置８０ｄは、循環油路５７ｉにおいて、右走行モータ３６Ｒの第４ポートＰ１４側に設けられ、第４ポートＰ１４側の圧力を第４走行圧Ｖ４として検出する。なお、第１圧力検出装置８０ａ、第２圧力検出装置８０ｂ、第３圧力検出装置８０ｃ、第４圧力検出装置８０ｄの設置位置は限定されず、左走行ポンプ５３Ｌのポート側、右走行ポンプ５３Ｒのポート側に設けてもよい。 Now, the control device 60 performs automatic deceleration based on the pressure in the circulation oil passages 57h and 57i. A plurality of pressure detection devices 80 are connected to the circulation oil passages 57h and 57i. The plurality of pressure detection devices 80 include a first pressure detection device 80a, a second pressure detection device 80b, a third pressure detection device 80c, and a fourth pressure detection device 80d. The first pressure detection device 80a is provided on the first port P11 side of the left travel motor 36L in the circulation oil passage 57h, and detects the pressure on the first port P11 side as the first travel pressure V1. The second pressure detection device 80b is provided on the second port P12 side of the left travel motor 36L in the circulation oil passage 57h, and detects the pressure on the second port P12 side as the second travel pressure V2. The third pressure detection device 80c is provided on the third port P13 side of the right travel motor 36R in the circulation oil passage 57i, and detects the pressure on the third port P13 side as the third travel pressure V3. The fourth pressure detection device 80d is provided on the fourth port P14 side of the right travel motor 36R in the circulation oil passage 57i, and detects the pressure on the fourth port P14 side as the fourth travel pressure V4. Note that the installation positions of the first pressure detection device 80a, the second pressure detection device 80b, the third pressure detection device 80c, and the fourth pressure detection device 80d are not limited; It may also be provided on the port side.

制御装置６０（自動減速部６１）は、第１圧力検出装置８０ａが検出した第１走行圧Ｖ１、第２圧力検出装置８０ｂが検出した第２走行圧Ｖ２、第３圧力検出装置８０ｃが検出した第３走行圧Ｖ３、第４圧力検出装置８０ｄが検出した第４走行圧Ｖ４に基づいて、自動減速を行う。
制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、左方向へ信地旋回する場合、右側の右走行モータ３６Ｒに対応する第３走行圧Ｖ３、第４走行圧Ｖ４を参照し、第３走行圧Ｖ３又は第４走行圧Ｖ４が第１左閾値ＳＴ１L以上であれば、自動減速を行う。また、制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、右方向へ信地旋回する場合、左走行モータ３６Ｌに対応する第１走行圧Ｖ１、第２走行圧Ｖ２を参照し、第１走行圧Ｖ１又は第２走行圧Ｖ２が第１右閾値ＳＴ１R以上であれば、自動減速を行う。 The control device 60 (automatic deceleration unit 61) has a first running pressure V1 detected by the first pressure detection device 80a, a second running pressure V2 detected by the second pressure detection device 80b, and a second running pressure V2 detected by the third pressure detection device 80c. Automatic deceleration is performed based on the third running pressure V3 and the fourth running pressure V4 detected by the fourth pressure detection device 80d.
When the travel motors (left travel motor 36L, right travel motor 36R) are at the second speed and the aircraft body 2 (left travel device 5L, right travel device 5R) makes a turn to the left, the control device 60 controls the right Referring to the third running pressure V3 and the fourth running pressure V4 corresponding to the running motor 36R, if the third running pressure V3 or the fourth running pressure V4 is equal to or higher than the first left threshold value ST1L , automatic deceleration is performed. Furthermore, when the traveling motors (left traveling motor 36L, right traveling motor 36R) are at the second speed and the aircraft body 2 (left traveling device 5L, right traveling device 5R) makes a pivot turn to the right, the control device 60 controls the left Referring to the first running pressure V1 and the second running pressure V2 corresponding to the running motor 36L, if the first running pressure V1 or the second running pressure V2 is equal to or higher than the first right threshold value ST1 R , automatic deceleration is performed.

ここで、信地旋回する場合とは、走行操作部材５９が信地旋回に対応する方向に操作されたとき、或いは、機体２が信地旋回をする挙動を示したときである。図２に示した走行操作部材５９の操作方向は、当該走行操作部材５９の操作方向を検出する操作検出装置（センサ）を設けたり、走行操作部材５９の操作によって作動油の圧力（パイロット圧）が変化する走行油路４５（第１走行油路４５ａ、第２走行油路４５ｂ、第３走行油路４５ｃ、第４走行油路４５ｄ）のパイロット圧を圧力検出装置で検出して、検出されたパイロット圧の変化によって検出してもよく、限定はされない。 Here, the case of a pivot turn is when the traveling operation member 59 is operated in a direction corresponding to a pivot turn, or when the aircraft 2 exhibits a behavior of making a pivot turn. The operation direction of the travel operation member 59 shown in FIG. The pilot pressure of the running oil passage 45 (the first running oil passage 45a, the second running oil passage 45b, the third running oil passage 45c, and the fourth running oil passage 45d) in which the pressure changes is detected by a pressure detection device. It may also be detected by a change in the pilot pressure, and is not limited to this.

即ち、制御装置６０は、前進で且つ左方向への信地旋回、前進で且つ右方向への信地旋回、後進で且つ左方向への信地旋回、後進で且つ右方向への信地旋回のときに、走行圧を参照しながら自動減速を行うか否かを判断する。
上述した実施形態では、左方向への信地旋回である場合、第３走行圧Ｖ３又は第４走行圧Ｖ４が第１左閾値ＳＴ１L以上、右方向への信地旋回である場合、第１走行圧Ｖ１又は第２走行圧Ｖ２が第１右閾値ＳＴ１R以上である場合に自動減速を行うか否かを判断しているが、これに代えて、有効の走行圧に基づいて自動減速を行うか否かを判断してもよい。 That is, the control device 60 controls a pivot turn to the left while moving forward, a pivot turn to the right while moving forward, a pivot turn to the left while traveling in reverse, and a pivot turn to the right while moving astern. At this time, it is determined whether or not to perform automatic deceleration while referring to the running pressure.
In the embodiment described above, when the pivot turn is to the left, the third running pressure V3 or the fourth running pressure V4 is equal to or higher than the first left threshold value ST1 L , and when the pivot turn is to the right, the first It is determined whether or not to perform automatic deceleration when the running pressure V1 or the second running pressure V2 is equal to or higher than the first right threshold value ST1 R , but instead of this, automatic deceleration is determined based on the effective running pressure. You may decide whether or not to do so.

制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、左方向へ信地旋回する場合、右側の右走行モータ３６Ｒに対応する有効の第３走行圧（第３走行圧Ｖ３から第４走行圧Ｖ４を減算した第３差圧ΔＶ３）、右走行モータ３６Ｒに対応する有効の第４走行圧（第４走行圧Ｖ４から第３走行圧Ｖ３を減算した第４差圧ΔＶ４）を演算し、第３差圧ΔＶ３又は第４差圧ΔＶ４が第２左閾値ＳＴ２L以上であれば、自動減速を行う。 When the travel motors (left travel motor 36L, right travel motor 36R) are at the second speed and the aircraft body 2 (left travel device 5L, right travel device 5R) makes a turn to the left, the control device 60 controls the right The effective third running pressure corresponding to the running motor 36R (the third differential pressure ΔV3 obtained by subtracting the fourth running pressure V4 from the third running pressure V3), the effective fourth running pressure corresponding to the right running motor 36R (the fourth running pressure A fourth differential pressure ΔV4) obtained by subtracting the third running pressure V3 from the running pressure V4 is calculated, and if the third differential pressure ΔV3 or the fourth differential pressure ΔV4 is greater than or equal to the second left threshold ST2L , automatic deceleration is performed.

制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、右方向へ信地旋回する場合、左側の左走行モータ３６Ｌに対応する有効の第１走行圧（第１走行圧Ｖ１から第２走行圧Ｖ２を減算した第１差圧ΔＶ１）、左側の左走行モータ３６Ｌに対応する有効の第２走行圧（第２走行圧Ｖ２から第１走行圧Ｖ１を減算した第２差圧ΔＶ２）を演算し、第１差圧ΔＶ１又は第２差圧ΔＶ２が第２右閾値ＳＴ２R以上であれば、自動減速を行う。 When the travel motors (left travel motor 36L, right travel motor 36R) are at the second speed and the aircraft body 2 (left travel device 5L, right travel device 5R) makes a pivot turn to the right, the control device 60 controls the left An effective first running pressure corresponding to the running motor 36L (first differential pressure ΔV1 obtained by subtracting the second running pressure V2 from the first running pressure V1), an effective second running pressure corresponding to the left running motor 36L ( A second differential pressure ΔV2) is calculated by subtracting the first running pressure V1 from the second running pressure V2, and if the first differential pressure ΔV1 or the second differential pressure ΔV2 is greater than or equal to the second right threshold ST2 R , automatic deceleration is performed. conduct.

さて、制御装置６０は、左方向への信地旋回時に使用する左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）、右方向への信地旋回時に使用する右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）の回転数に基づいて設定する。つまり、制御装置６０は、自動減速の減速を判断するための減速閾値として、左閾値と右閾値とを走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）の回転数に基づいて設定する。 Now, the control device 60 controls the left thresholds (first left threshold ST1 L , second left threshold ST2 L ) used when turning to the left, the right threshold (first threshold) used when turning to the right. The right threshold value ST1 R and the second right threshold value ST2 R ) are set based on the rotation speed of the travel motors (left travel motor 36L, right travel motor 36R). That is, the control device 60 sets a left threshold value and a right threshold value as deceleration threshold values for determining deceleration in automatic deceleration based on the rotation speed of the travel motors (left travel motor 36L, right travel motor 36R).

以下、説明の便宜上、左走行モータ３６Ｌの回転数は、「第１回転数ＬＭRPM」、右走行モータ３６Ｒの回転数を「第２回転数ＲＭRPM」とする。
図３は、左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）と第２回転数ＲＭRPMとの関係を示している。なお、図３は説明の便宜上、第２回転数ＲＭRPMに対して、第１左閾値ＳＴ１L、第２左閾値ＳＴ２Lの２つの左閾値を示しているが、制御装置６０は、第１左閾値ＳＴ１L、第２左閾値ＳＴ２Lのどちらか一方を設定すればよい。
図３に示すように、制御装置６０は、左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）を、第２回転数ＲＭRPMが低くなるにつれて低く設定し、第２回転数ＲＭRPMが高くなるにつれて高く設定する。図３に示すように、制御装置６０は、第２回転数ＲＭRPMと左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）との関係を示すラインＬ１、Ｌ２に、第２回転検出装置６８ｂによって検出した第２回転数ＲＭRPMを適用することにより、左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）を設定してもよい。或いは、第２回転数ＲＭRPMと第１左閾値ＳＴ１L、第２左閾値ＳＴ２Lとの関係を示す式、テーブル等の制御データを予め記憶部６３に記憶しておき、制御装置６０は、第２回転検出装置６８ｂによって検出した第２回転数ＲＭRPMに対応する第１左閾値ＳＴ１L、第２左閾値ＳＴ２Lを抽出することで、左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）を設定してもよい。 Hereinafter, for convenience of explanation, the rotation speed of the left travel motor 36L will be referred to as a "first rotation speed LM RPM ", and the rotation speed of the right travel motor 36R will be referred to as a "second rotation speed RM RPM ".
FIG. 3 shows the relationship between the left threshold values (first left threshold value ST1 L , second left threshold value ST2 L ) and the second rotation speed RM RPM . For convenience of explanation, FIG. 3 shows two left thresholds, the first left threshold ST1 L and the second left threshold ST2 L , with respect to the second rotation speed RM RPM . Either one of the left threshold ST1 L and the second left threshold ST2 L may be set.
As shown in FIG. 3, the control device 60 sets the left thresholds (first left threshold ST1 L , second left threshold ST2 L ) lower as the second rotation speed RM RPM becomes lower, and Set higher as RPM increases. As shown in FIG. 3, the control device 60 adds lines L1 and L2 indicating the relationship between the second rotation speed RM RPM and the left threshold (first left threshold ST1 L , second left threshold ST2 L ) to the second rotation speed RM RPM. The left threshold values (first left threshold value ST1 L , second left threshold value ST2 L ) may be set by applying the second rotation speed RM RPM detected by the detection device 68b. Alternatively, control data such as equations and tables showing the relationship between the second rotation speed RM RPM and the first left threshold ST1 L and the second left threshold ST2 L are stored in advance in the storage unit 63, and the control device 60 By extracting the first left threshold ST1 L and second left threshold ST2 L corresponding to the second rotation speed RM RPM detected by the second rotation detection device 68b, the left threshold (first left threshold ST1 L , second left threshold ST1 L A threshold value ST2 L ) may be set.

また、図４は、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）と第１回転数ＬＭRPMとの関係を示している。なお、図３は説明の便宜上、第１回転数ＬＭRPMに対して、第１右閾値ＳＴ１R、第２右閾値ＳＴ２Rの２つの右閾値を示しているが、制御装置６０は、第１右閾値ＳＴ１R、第２右閾値ＳＴ２Rのどちらか一方を設定すればよい。
図４に示すように、制御装置６０は、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を、第１回転数ＬＭRPMが低くなるにつれて低く設定し、第１回転数ＬＭRPMが高くなるにつれて高く設定する。図４に示すように、制御装置６０は、第１回転数ＬＭRPMと右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）との関係を示すラインＬ３、Ｌ４に、第１回転検出装置６８ａによって検出した第１回転数ＬＭRPMを適用することにより、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を設定してもよい。或いは、第１回転数ＬＭRPMと、第１右閾値ＳＴ１R、第２右閾値ＳＴ２Rとの関係を示す式、テーブル等の制御データを予め記憶部６３に記憶しておき、制御装置６０は、第１回転検出装置６８ａによって検出した第１回転数ＬＭRPMに対応する第１右閾値ＳＴ１R、第２右閾値ＳＴ２Rを抽出することで、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を設定してもよい。 Moreover, FIG. 4 shows the relationship between the right threshold value (first right threshold value ST1 R , second right threshold value ST2 R ) and the first rotation speed LM RPM . For convenience of explanation, FIG. 3 shows two right thresholds, the first right threshold ST1 R and the second right threshold ST2 R , with respect to the first rotation speed LM RPM . Either one of the right threshold ST1 R and the second right threshold ST2 R may be set.
As shown in FIG. 4, the control device 60 sets the right thresholds (first right threshold ST1 R , second right threshold ST2 R ) lower as the first rotation speed LM RPM becomes lower, and Set higher as RPM increases. As shown in FIG. 4, the control device 60 adds lines L3 and L4 indicating the relationship between the first rotation speed LM RPM and the right threshold (first right threshold ST1 R , second right threshold ST2 R ) to the first rotation speed LM RPM. The right threshold values (first right threshold value ST1 R , second right threshold value ST2 R ) may be set by applying the first rotation speed LM RPM detected by the detection device 68a. Alternatively, control data such as equations and tables showing the relationship between the first rotation speed LM RPM , the first right threshold ST1 R , and the second right threshold ST2 R may be stored in the storage unit 63 in advance, and the control device 60 may , by extracting the first right threshold ST1 R and the second right threshold ST2 R corresponding to the first rotation speed LM RPM detected by the first rotation detection device 68a, the right threshold (first right threshold ST1 R , second right threshold ST1 R A right threshold ST2 R ) may be set.

つまり、制御装置６０は、左方向への信地旋回時には、左走行モータ３６Ｌとは反対側の右走行モータ３６Ｒの第２回転数ＲＭRPMによって設定された左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）により自動減速を行い、右方向への信地旋回時には、右走行モータ３６Ｒとは反対側の左走行モータ３６Ｌの第１回転数ＬＭRPMによって設定された右閾値（第１右閾値ＳＴ１R、第２左閾値ＳＴ２L）により自動減速を行う。 In other words, when turning to the left, the control device 60 controls the left threshold (first left threshold ST1 L , Automatic deceleration is performed according to the second left threshold ST2 L ), and when turning to the right, the right threshold ( ST2 Automatic deceleration is performed using the first right threshold ST1 R and the second left threshold ST2 L .

詳しくは、制御装置６０は、左方向への信地旋回時は、第２回転数ＲＭRPMを参照して、第１左閾値ＳＴ１Lの設定を行う。第１左閾値ＳＴ１Lの設定後、制御装置６０は、第３走行圧Ｖ３又は第４走行圧Ｖ４が第１左閾値ＳＴ１L以上である場合には、自動減速を行う。或いは、制御装置６０は、左方向への信地旋回時は、第２回転数ＲＭRPMを参照して、第２左閾値ＳＴ２Lの設定を行う。第２左閾値ＳＴ２Lの設定後、制御装置６０は、第３差圧ΔＶ３又は第４差圧ΔＶ４が第２左閾値ＳＴ２L以上である場合には、自動減速を行う。 Specifically, during a pivot turn to the left, the control device 60 refers to the second rotation speed RM RPM and sets the first left threshold ST1 L. After setting the first left threshold ST1 L , the control device 60 performs automatic deceleration if the third running pressure V3 or the fourth running pressure V4 is equal to or higher than the first left threshold ST1 L. Alternatively, when making a pivot turn to the left, the control device 60 refers to the second rotation speed RM RPM and sets the second left threshold ST2 L. After setting the second left threshold ST2 L , the control device 60 performs automatic deceleration if the third differential pressure ΔV3 or the fourth differential pressure ΔV4 is equal to or greater than the second left threshold ST2 L.

また、制御装置６０は、右方向への信地旋回時は、第１回転数ＬＭRPMを参照して、第１右閾値ＳＴ１Rの設定を行う。第１右閾値ＳＴ１Rの設定後、制御装置６０は、第１走行圧Ｖ１又は第２走行圧Ｖ２が第１右閾値ＳＴ１R以上である場合には、自動減速を行う。或いは、制御装置６０は、右方向への信地旋回時は、第１回転数ＬＭRPMを参照して、第２右閾値ＳＴ２Rの設定を行う。第２右閾値ＳＴ２Rの設定後、制御装置６０は、第１差圧ΔＶ１又は第２差圧ΔＶ２が第２右閾値ＳＴ２R以上である場合には、自動減速を行う。 Furthermore, during a rightward turn, the control device 60 refers to the first rotation speed LM RPM and sets the first right threshold ST1 R. After setting the first right threshold ST1 R , the control device 60 performs automatic deceleration if the first running pressure V1 or the second running pressure V2 is equal to or higher than the first right threshold ST1 R. Alternatively, when making a pivot turn to the right, the control device 60 refers to the first rotation speed LM RPM and sets the second right threshold ST2 R. After setting the second right threshold ST2 R , the control device 60 performs automatic deceleration if the first differential pressure ΔV1 or the second differential pressure ΔV2 is greater than or equal to the second right threshold ST2 R.

なお、制御装置６０は、原動機３２の回転数に応じて左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を変更してもよい。
また、上述した実施形態では、図３，４に示すように、第１回転数ＬＭRPM、第２回転数ＲＭRPMに基づいて、左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を設定していたが、第１回転数ＬＭRPM、第２回転数ＲＭRPMが閾値Ｍ３０以上で大きいとき、即ち、最大回転数から閾値Ｍ３０であるときは、自動減速を行わないようにしてもよい。なお、説明の便宜上、第１回転数ＬＭRPM、第２回転数ＲＭRPMにおける左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）、右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）の設定は、閾値Ｍ３０以下で行っている（ラインＬ１、Ｌ２が閾値Ｍ３０までになっている）が、左閾値及び右閾値の演算は、閾値Ｍ３０以上で行っても問題はない。 Note that the control device 60 controls the left threshold value (first left threshold value ST1 L , second left threshold value ST2 L ) and right threshold value (first right threshold value ST1 R , second right threshold value ST2 R ) according to the rotation speed of the prime mover 32. may be changed.
In addition, in the embodiment described above, as shown in FIGS. 3 and 4, the left threshold values (first left threshold ST1 L , second left threshold ST2 L ), right thresholds (first right threshold ST1 R , second right threshold ST2 R ) were set, but when the first rotation speed LM RPM and the second rotation speed RM RPM are larger than the threshold M30, that is, the maximum When the rotational speed is at the threshold value M30, automatic deceleration may not be performed. For convenience of explanation, the left threshold (first left threshold ST1 L , second left threshold ST2 L ) , right threshold (first right threshold ST1 R , second The right threshold ST2 R ) is set below the threshold M30 (lines L1 and L2 are up to the threshold M30), but there is no problem even if the left and right thresholds are calculated above the threshold M30. do not have.

制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、左方向又は右方向へ超信地旋回する場合、第１走行圧Ｖ１、第２走行圧Ｖ２、第３走行圧Ｖ３、第４走行圧Ｖ４のいずれかが、第１超信地閾値ＳＴ１P以上であれば、自動減速を行う。
或いは、制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が、左方向又は右方向へ超信地旋回する場合、第１差圧ΔＶ１、第２差圧ΔＶ２、第３差圧ΔＶ３、第４差圧ΔＶ４のいずれかが、第２超信地閾値ＳＴ２P以上であれば、自動減速を行う。 The control device 60 controls when the traveling motors (left traveling motor 36L, right traveling motor 36R) are at the second speed and the aircraft body 2 (left traveling device 5L, right traveling device 5R) makes a sharp turn to the left or right. , the first running pressure V1, the second running pressure V2, the third running pressure V3, and the fourth running pressure V4 are greater than or equal to the first super-strength threshold ST1P , automatic deceleration is performed.
Alternatively, the control device 60 controls whether the travel motors (left travel motor 36L, right travel motor 36R) are at the second speed and the aircraft body 2 (left travel device 5L, right travel device 5R) is set to the travel motor (left travel motor 36L, right travel motor 36R). When the motor 36R) is at the second speed and the aircraft 2 (left traveling device 5L, right traveling device 5R) makes a sharp turn to the left or right, the first differential pressure ΔV1, the second differential pressure ΔV2, and the third If either the differential pressure ΔV3 or the fourth differential pressure ΔV4 is equal to or greater than the second super-strength threshold ST2P , automatic deceleration is performed.

制御装置６０は、機体が超信地旋回する場合に減速閾値である超信地閾値（第１超信地閾値ＳＴ１P、第２超信地閾値ＳＴ２P）を、上述した左閾値及び右閾値よりも低い値に設定する。
なお、制御装置６０は、左走行モータ３６Ｌの第１回転数ＬＭRPMと右走行モータ３６Ｒの第２回転数ＲＭRPMとのうち、高い方の回転数に応じて超信地閾値を設定してもよい。 The control device 60 sets super pivot thresholds (first super pivot threshold ST1 P , second super pivot threshold ST2 P ), which are deceleration thresholds when the aircraft makes a super pivot turn, based on the left threshold and right threshold described above. Set to a value lower than .
Note that the control device 60 sets the super-spin threshold according to the higher rotation speed of the first rotation speed LM RPM of the left travel motor 36L and the second rotation speed RM RPM of the right travel motor 36R. Good too.

制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が直進であって前進する場合は、第１走行圧Ｖ１及び第３走行圧Ｖ３のいずれかが第１直進閾値ＳＦ１S以上であるとき、自動減速を行う。
或いは、制御装置６０は、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）が第２速度且つ機体２（左走行装置５Ｌ、右走行装置５Ｒ）が直進であって前進する場合は、第１差圧ΔＶ１及び第３差圧ΔＶ３のいずれかが第２直進閾値ＳＦ２S以上であるとき、自動減速を行う。ここで、直進する場合とは、走行操作部材５９が直進に対応する方向に操作されたとき、或いは、機体２が直進をする挙動を示したときである。なお、走行操作部材５９による直進の操作は、上述した信地旋回と同様に、操作検出装置（センサ）、圧力検出装置等で検出することができる。また、制御装置６０は、走行操作部材５９の操作が信地旋回側から直進側に向けて操作が変化したときも、直進閾値によって自動減速を行うか否かを判断する。また、走行操作部材５９における直進の操作は、図２に示したように、前方側及び後方側にそれぞれ走行操作部材５９を傾けたときであり、走行操作部材５９の操作方向は、斜めであったとしても、直進として許容される所定範囲内であれば、直進の操作に含まれる。 When the traveling motors (left traveling motor 36L, right traveling motor 36R) are at the second speed and the aircraft body 2 (left traveling device 5L, right traveling device 5R) is traveling straight ahead, the control device 60 controls the first traveling pressure. Automatic deceleration is performed when either V1 or third running pressure V3 is equal to or higher than first straight-line threshold SF1 S.
Alternatively, when the traveling motors (left traveling motor 36L, right traveling motor 36R) are at the second speed and the aircraft 2 (left traveling device 5L, right traveling device 5R) is moving straight ahead, the control device 60 controls the first speed. When either the differential pressure ΔV1 or the third differential pressure ΔV3 is greater than or equal to the second straight-line threshold SF2 S , automatic deceleration is performed. Here, the case of going straight is when the traveling operation member 59 is operated in a direction corresponding to going straight, or when the aircraft body 2 exhibits a behavior of going straight. Note that the straight-ahead operation using the traveling operation member 59 can be detected by an operation detection device (sensor), a pressure detection device, etc., similarly to the above-mentioned turn. Further, the control device 60 also determines whether or not to perform automatic deceleration based on the straight-ahead threshold value when the operation of the traveling operation member 59 changes from the turning side to the straight-ahead side. Further, as shown in FIG. 2, the straight-ahead operation of the travel operation member 59 is performed when the travel operation member 59 is tilted forward and backward, and the operation direction of the travel operation member 59 is oblique. However, as long as it is within a predetermined range that is allowed as going straight, it is included in the operation of going straight.

制御装置６０は、第１回転検出装置６８ａが検出した第１回転数ＬＭRPMと、第２回転検出装置が検出した第２回転数ＲＭRPMとの回転差ΔＭＰに基づいて、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を設定する。なお、回転差ΔＭＰは、第１回転数ＬＭRPMから第２回転数ＲＭRPMを減算した値であっても、第２回転数ＲＭRPMから第１回転数ＬＭRPMであってもよい。また、回転差ΔＭＰは、マイナス値になる場合は、絶対値となる。 The control device 60 sets a straight -line threshold (first A straight-line threshold SF1 S and a second straight-line threshold SF2 S are set. Note that the rotational difference ΔMP may be a value obtained by subtracting the second rotational speed RM RPM from the first rotational speed LM RPM , or may be a value obtained by subtracting the second rotational speed RM RPM from the second rotational speed RM RPM . Moreover, when the rotational difference ΔMP becomes a negative value, it becomes an absolute value.

図５は、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）と、回転差ΔＭＰとの関係を示している。なお、図５は説明の便宜上、回転差ΔＭＰに対して、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sの２つの直進閾値を示しているが、制御装置６０は、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sのどちらか一方を設定すればよい。
図５に示すように、制御装置６０は、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を、回転差ΔＭＰが大きくなるにつれて高く設定し、回転差ΔＭＰが小さくなるにつれて低く設定する。図５に示すように、制御装置６０は、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sと回転差ΔＭＰとの関係を示すラインＬ５、Ｌ６に、演算した回転差ΔＭＰを適用することにより、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。或いは、回転差ΔＭＰと第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sとの関係を示す式、テーブル等の制御データを予め記憶部６３に記憶しておき、制御装置６０は、演算した回転差ΔＭＰに対応する第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを抽出することで、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。 FIG. 5 shows the relationship between the straight-ahead thresholds (first straight-ahead threshold SF1 S , second straight-ahead threshold SF2 S ) and the rotational difference ΔMP. For convenience of explanation, FIG. 5 shows two straight-line thresholds, the first straight-line threshold SF1 S and the second straight-line threshold SF2 S , with respect to the rotational difference ΔMP. S or the second straight-travel threshold SF2 S may be set.
As shown in FIG. 5, the control device 60 sets the straight-ahead thresholds (first straight-ahead threshold SF1 S , second straight-ahead threshold SF2 S ) higher as the rotation difference ΔMP increases, and sets them lower as the rotation difference ΔMP decreases. Set. As shown in FIG. 5, the control device 60 applies the calculated rotational difference ΔMP to lines L5 and L6 indicating the relationship between the first straight-line threshold SF1 S , the second straight-line threshold SF2 S and the rotational difference ΔMP. , a first straight-line threshold SF1 S , and a second straight-line threshold SF2 S may be set. Alternatively, control data such as equations and tables showing the relationship between the rotational difference ΔMP and the first straight-line threshold SF1 S and second straight-line threshold SF2 S may be stored in advance in the storage unit 63, and the control device 60 may calculate the calculated rotation. The first straight-line threshold SF1 S and the second straight-line threshold SF2 S may be set by extracting the first straight-line threshold SF1 S and second straight-line threshold SF2 S corresponding to the difference ΔMP.

つまり、制御装置６０は、直進、即ち、前進時には、第１回転数ＬＭRPMと、第２回転数ＲＭRPMとの回転差ΔＭＰによって設定された直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）により自動減速を行う。
詳しくは、制御装置６０は、前進時は、第１回転数ＬＭRPMと第２回転数ＲＭRPMとを参照して、回転差ΔＭＰを演算し、演算した回転差ΔＭＰにより、第１直進閾値ＳＦ１Sの設定を行う。第１直進閾値ＳＦ１Sの設定後、制御装置６０は、第１走行圧Ｖ１又は第３走行圧Ｖ３が第１直進閾値ＳＦ１S以上である場合には、自動減速を行う。或いは、制御装置６０は、前進時は、回転差ΔＭＰを演算し、演算した回転差ΔＭＰにより、第２直進閾値ＳＦ２Sの設定を行う。第２直進閾値ＳＦ２Sの設定後、制御装置６０は、第１差圧ΔＶ１又は第３差圧ΔＶ３が第２直進閾値ＳＦ２S以上である場合には、自動減速を行う。 In other words, when traveling straight, that is, when moving forward, the control device 60 sets a straight traveling threshold (a first straight traveling threshold SF1 S , a second straight traveling threshold SF1 S , a second straight traveling threshold SF1 S , a second straight traveling threshold Automatic deceleration is performed based on the threshold value SF2 S ).
Specifically, when moving forward, the control device 60 refers to the first rotation speed LM RPM and the second rotation speed RM RPM , calculates the rotation difference ΔMP, and uses the calculated rotation difference ΔMP to set the first straight-line threshold SF1. Configure S. After setting the first straight-ahead threshold SF1 S , the control device 60 performs automatic deceleration if the first running pressure V1 or the third running pressure V3 is equal to or higher than the first straight-ahead threshold SF1 S. Alternatively, during forward movement, the control device 60 calculates the rotational difference ΔMP, and sets the second straight-travel threshold SF2 S based on the calculated rotational difference ΔMP. After setting the second straight-line threshold SF2 S , the control device 60 automatically decelerates if the first differential pressure ΔV1 or the third differential pressure ΔV3 is equal to or higher than the second straight-line threshold SF2 S.

上述した実施形態では、回転差ΔＭＰに基づいて、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを求めていたが、これに代えて、回転比率の比率差ΔＤＰに基づいて、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを求めてもよい。回転比率の比率差ΔＤＰは、第１回転数ＬＭRPMから第２回転数ＲＭRPMを除算した第１比率と、第２回転数ＲＭRPMから第１回転数ＬＭRPMを除算した第２比率との差である。比率差ΔＤＰがマイナス値になる場合は、絶対値を適用する。 In the embodiment described above, the first straight-line threshold SF1 S and the second straight-line threshold SF2 S are determined based on the rotational difference ΔMP. The threshold value SF1 S and the second straight-line threshold value SF2 S may also be determined. The ratio difference ΔDP in the rotation ratio is the first ratio obtained by dividing the second rotation speed RM RPM from the first rotation speed LM RPM , and the second ratio obtained by dividing the first rotation speed LM RPM from the second rotation speed RM RPM . It's the difference. If the ratio difference ΔDP is a negative value, the absolute value is applied.

制御装置６０は、第１回転数ＬＭRPMと第２回転数ＲＭRPMとを用いて、比率差ΔＤＰを求め、比率差ΔＤＰに基づいて、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を設定する。
図６Ａは、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）と比率差ΔＤＰとの関係を示している。なお、図６は説明の便宜上、比率差ΔＤＰに対して、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sの２つの直進閾値を示しているが、制御装置６０は、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sのどちらか一方を設定すればよい。 The control device 60 uses the first rotation speed LM RPM and the second rotation speed RM RPM to determine the ratio difference ΔDP, and based on the ratio difference ΔDP, the straight-line threshold (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) is set.
FIG. 6A shows the relationship between the straight-ahead thresholds (first straight-ahead threshold SF1 S , second straight-ahead threshold SF2 S ) and the ratio difference ΔDP. For convenience of explanation, FIG. 6 shows two straight-line thresholds, the first straight-line threshold SF1 S and the second straight-line threshold SF2 S , with respect to the ratio difference ΔDP. S or the second straight-travel threshold SF2 S may be set.

図６Ａに示すように、制御装置６０は、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を、比率差ΔＤＰが大きくなるにつれて高く設定し、比率差ΔＤＰが小さくなるにつれて低く設定する。図６Ａに示すように、制御装置６０は、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sと比率差ΔＤＰとの関係を示すラインＬ７、Ｌ８に、演算した比率差ΔＤＰを適用することにより、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。或いは、比率差ΔＤＰと第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sとの関係を示す式、テーブル等の制御データを予め記憶部６３に記憶しておき、制御装置６０は、演算した比率差ΔＤＰに対応する第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを抽出することで、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。 As shown in FIG. 6A, the control device 60 sets the straight-ahead thresholds (first straight-ahead threshold SF1 S , second straight-ahead threshold SF2 S ) higher as the ratio difference ΔDP increases, and sets them lower as the ratio difference ΔDP decreases. Set. As shown in FIG. 6A, the control device 60 applies the calculated ratio difference ΔDP to lines L7 and L8 indicating the relationship between the first straight-line threshold SF1 S , the second straight-straight threshold SF2 S , and the ratio difference ΔDP. , a first straight-line threshold SF1 S , and a second straight-line threshold SF2 S may be set. Alternatively, control data such as equations and tables showing the relationship between the ratio difference ΔDP and the first straight-line threshold SF1 S and second straight-line threshold SF2 S may be stored in advance in the storage unit 63, and the control device 60 may calculate the calculated ratio. The first straight-line threshold SF1 S and the second straight-line threshold SF2 S may be set by extracting the first straight-line threshold SF1 S and second straight-line threshold SF2 S corresponding to the difference ΔDP.

つまり、制御装置６０は、前進時には、第１回転数ＬＭRPMと第２回転数ＲＭRPMとの回転比率の差ΔＤＰによって設定された直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）により自動減速を行う。
詳しくは、制御装置６０は、前進時は、第１回転数ＬＭRPMと第２回転数ＲＭRPMとを参照して、回転比率の差ΔＤＰを演算し、演算した回転比率の差ΔＤＰにより、第１直進閾値ＳＦ１Sの設定を行う。第１直進閾値ＳＦ１Sの設定後、制御装置６０は、第１走行圧Ｖ１又は第３走行圧Ｖ３が第１直進閾値ＳＦ１S以上である場合には、自動減速を行う。或いは、制御装置６０は、前進時は、回転比率の差ΔＤＰを演算し、演算した回転比率の差ΔＤＰにより、第２直進閾値ＳＦ２Sの設定を行う。第２直進閾値ＳＦ２Sの設定後、制御装置６０は、第１差圧ΔＶ１又は第３差圧ΔＶ３が第２直進閾値ＳＦ２S以上である場合には、自動減速を行う。 In other words, when moving forward, the control device 60 controls the straight-line thresholds (first straight-line threshold SF1 S , second straight- line threshold SF2 S ) to automatically decelerate.
Specifically, during forward movement, the control device 60 refers to the first rotation speed LM RPM and the second rotation speed RM RPM , calculates the rotation ratio difference ΔDP, and uses the calculated rotation ratio difference ΔDP to calculate the rotation ratio difference ΔDP. 1. Set the straight-line threshold SF1 S. After setting the first straight-ahead threshold SF1 S , the control device 60 performs automatic deceleration if the first running pressure V1 or the third running pressure V3 is equal to or higher than the first straight-ahead threshold SF1 S. Alternatively, during forward movement, the control device 60 calculates the rotation ratio difference ΔDP, and sets the second straight-ahead threshold SF2 S based on the calculated rotation ratio difference ΔDP. After setting the second straight-line threshold SF2 S , the control device 60 automatically decelerates if the first differential pressure ΔV1 or the third differential pressure ΔV3 is equal to or higher than the second straight-line threshold SF2 S.

なお、上述した実施形態では、比率差ΔＤＰに基づいて、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を設定していたが、第１回転数ＬＭRPMと第２回転数ＲＭRPMとの比率ΔＤＱに基づいて、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を求めてもよい。
図６Ｂに示すように、制御装置６０は、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を、比率ΔＤＱが小さくなるにつれて高く設定し、比率ΔＤＱが大きくなるにつれて低く設定する。図６Ｂに示すように、制御装置６０は、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sと比率ΔＤＱとの関係を示すラインＬ９、Ｌ１０に、演算した比率ΔＤＱを適用することにより、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。或いは、比率ΔＤＱと第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sとの関係を示す式、テーブル等の制御データを予め記憶部６３に記憶しておき、制御装置６０は、演算した比率ΔＤＱに対応する第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを抽出することで、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。 In the embodiment described above, the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) were set based on the ratio difference ΔDP, but the first rotation speed LM RPM and the second rotation speed The straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) may be determined based on the ratio ΔDQ to RM RPM .
As shown in FIG. 6B, the control device 60 sets the straight-ahead thresholds (first straight-ahead threshold SF1 S , second straight-ahead threshold SF2 S ) higher as the ratio ΔDQ becomes smaller, and lower as the ratio ΔDQ becomes larger. . As shown in FIG. 6B, the control device 60 applies the calculated ratio ΔDQ to lines L9 and L10 indicating the relationship between the first straight-line threshold SF1 S , the second straight-line threshold SF2 S and the ratio ΔDQ. A first straight-line threshold SF1 S and a second straight-line threshold SF2 S may be set. Alternatively, control data such as equations and tables showing the relationship between the ratio ΔDQ and the first straight-line threshold SF1 S and second straight-line threshold SF2 S may be stored in advance in the storage unit 63, and the control device 60 may calculate the calculated ratio ΔDQ. The first straight-line threshold SF1 S and the second straight-line threshold SF2 S may be set by extracting the first straight-line threshold SF1 S and second straight-line threshold SF2 S corresponding to .

つまり、制御装置６０は、前進時には、第１回転数ＬＭRPMと第２回転数ＲＭRPMとの比率ΔＤＱによって設定された直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）により自動減速を行う。
詳しくは、制御装置６０は、前進時は、第１回転数ＬＭRPMと第２回転数ＲＭRPMとを参照して、比率ΔＤＱを演算し、演算した比率ΔＤＱにより、第１直進閾値ＳＦ１Sの設定を行う。第１直進閾値ＳＦ１Sの設定後、制御装置６０は、第１走行圧Ｖ１又は第３走行圧Ｖ３が第１直進閾値ＳＦ１S以上である場合には、自動減速を行う。或いは、制御装置６０は、前進時は、比率ΔＤＱを演算し、演算した比率ΔＤＱにより、第２直進閾値ＳＦ２Sの設定を行う。第２直進閾値ＳＦ２Sの設定後、制御装置６０は、第１差圧ΔＶ１又は第３差圧ΔＶ３が第２直進閾値ＳＦ２S以上である場合には、自動減速を行う。 In other words, when moving forward, the control device 60 automatically uses the straight-line threshold (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) set by the ratio ΔDQ of the first rotation speed LM RPM and the second rotation speed RM RPM . Perform deceleration.
Specifically, when moving forward, the control device 60 refers to the first rotation speed LM RPM and the second rotation speed RM RPM , calculates the ratio ΔDQ, and uses the calculated ratio ΔDQ to set the first straight-line threshold SF1 S. Make settings. After setting the first straight-ahead threshold SF1 S , the control device 60 performs automatic deceleration if the first running pressure V1 or the third running pressure V3 is equal to or higher than the first straight-ahead threshold SF1 S. Alternatively, when the vehicle is moving forward, the control device 60 calculates the ratio ΔDQ, and sets the second straight-travel threshold SF2 S based on the calculated ratio ΔDQ. After setting the second straight-line threshold SF2 S , the control device 60 automatically decelerates if the first differential pressure ΔV1 or the third differential pressure ΔV3 is equal to or higher than the second straight-line threshold SF2 S.

上述した実施形態では、回転差ΔＭＰ、回転比率の比率差ΔＤＰに基づいて、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを求めていたが、これに代えて、第１回転数ＬＭRPM、第２回転数ＲＭRPMに基づいて、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを求めてもよい。
図７に示すように、制御装置６０は、直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を、第１回転数ＬＭRPM、第２回転数ＲＭRPMが大きくなるにつれて低く設定し、第１回転数ＬＭRPM、第２回転数ＲＭRPMが小さくなるにつれて高く設定する。図７に示すように、制御装置６０は、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sと第１回転数ＬＭRPM、第２回転数ＲＭRPMとの関係を示すラインＬ１１、Ｌ１２に、第１回転検出装置６８ａが検出した第１回転数ＬＭRPM、第２回転検出装置６８ｂが検出した第２回転数ＲＭRPMを適用することにより、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。或いは、第１回転数ＬＭRPM、第２回転数ＲＭRPMと第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sとの関係を示す式、テーブル等の制御データを予め記憶部６３に記憶しておき、制御装置６０は、第１回転数ＬＭRPM、第２回転数ＲＭRPMに対応する第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを抽出することで、第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２Sを設定してもよい。 In the embodiment described above, the first straight-line threshold SF1 S and the second straight-line threshold SF2 S are determined based on the rotation difference ΔMP and the rotation ratio ratio difference ΔDP, but instead of this, the first rotation speed LM RPM , the first straight-line threshold SF1 S and the second straight-line threshold SF2 S may be determined based on the second rotational speed RM RPM .
As shown in FIG. 7, the control device 60 sets the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) to be lower as the first rotation speed LM RPM and the second rotation speed RM RPM become larger. However, as the first rotation speed LM RPM and the second rotation speed RM RPM become smaller, they are set higher. As shown in FIG. 7, the control device 60 creates lines L11 and L12 indicating the relationship between the first straight-line threshold SF1 S and the second straight-line threshold SF2 S and the first rotation speed LM RPM and the second rotation speed RM RPM . By applying the first rotation speed LM RPM detected by the first rotation detection device 68a and the second rotation speed RM RPM detected by the second rotation detection device 68b, the first straight-line threshold SF1 S and the second straight-line threshold SF2 S may be set. Alternatively, control data such as equations and tables showing the relationship between the first rotation speed LM RPM , the second rotation speed RM RPM and the first straight-line threshold SF1 S and second straight-line threshold SF2 S may be stored in the storage unit 63 in advance. Then, the control device 60 extracts the first straight-line threshold SF1 S and the second straight-line threshold SF2 S corresponding to the first rotation speed LM RPM and the second rotation speed RM RPM . A threshold value SF2 S for going straight ahead may be set.

つまり、制御装置６０は、前進時には、第１回転数ＬＭRPM、第２回転数ＲＭRPMによって設定された直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）により自動減速を行う。
詳しくは、制御装置６０は、前進時は、第１回転数ＬＭRPM、第２回転数ＲＭRPMを参照し、第１回転数ＬＭRPM、第２回転数ＲＭRPMから第１直進閾値ＳＦ１Sの設定を行う。第１直進閾値ＳＦ１Sの設定後、制御装置６０は、第１走行圧Ｖ１と第３走行圧Ｖ３との両方が継続して第１直進閾値ＳＦ１S以上である場合には、自動減速を行う。より詳しくは、第１走行圧Ｖ１と第３走行圧Ｖ３との両方が第１直進閾値ＳＦ１S以上である時間（経過時間）の長さが第１判定時間以上であるとき、自動減速を行う。制御装置６０は、第１判定時間を、第１回転数ＬＭRPM、第２回転数ＲＭRPMが大きくなるにしたがって短く設定し、第１回転数ＬＭRPM、第２回転数ＲＭRPMが小さくなるにしたがって長く設定する。 That is, when moving forward, the control device 60 automatically decelerates using the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) set by the first rotation speed LM RPM and the second rotation speed RM RPM.
Specifically, when moving forward, the control device 60 refers to the first rotation speed LM RPM and the second rotation speed RM RPM , and determines the first straight-line threshold SF1 S from the first rotation speed LM RPM and the second rotation speed RM RPM . Make settings. After setting the first straight-ahead threshold SF1 S , the control device 60 automatically decelerates if both the first running pressure V1 and the third running pressure V3 are continuously equal to or higher than the first straight-ahead threshold SF1 S. . More specifically, automatic deceleration is performed when the length of time (elapsed time) during which both the first running pressure V1 and the third running pressure V3 are equal to or greater than the first straight-line threshold SF1 S is equal to or greater than the first determination time. . The control device 60 sets the first determination time to be shorter as the first rotation speed LM RPM and the second rotation speed RM RPM become larger, and as the first rotation speed LM RPM and the second rotation speed RM RPM become smaller, the first determination time is set shorter. Therefore, set it long.

或いは、制御装置６０は、前進時は、第１回転数ＬＭRPM、第２回転数ＲＭRPMを参照し、第１回転数ＬＭRPM、第２回転数ＲＭRPMから第２直進閾値ＳＦ２Sの設定を行う。第２直進閾値ＳＦ２Sの設定後、制御装置６０は、第１差圧ΔＶ１と第３差圧ΔＶ３との両方が継続して第２直進閾値ＳＦ２S以上である場合には、自動減速を行う。より詳しくは、第１差圧ΔＶ１と第３差圧ΔＶ３との両方が第２直進閾値ＳＦ２S以上である時間（経過時間）の長さが第２判定時間以上であるとき、自動減速を行う。制御装置６０は、第２判定時間を、第１回転数ＬＭRPM、第２回転数ＲＭRPMが大きくなるにしたがって短く設定し、第１回転数ＬＭRPM、第２回転数ＲＭRPMが小さくなるにしたがって長く設定する。 Alternatively, when moving forward, the control device 60 refers to the first rotation speed LM RPM and the second rotation speed RM RPM , and sets the second straight-line threshold SF2 S from the first rotation speed LM RPM and the second rotation speed RM RPM . I do. After setting the second straight-line threshold SF2 S , the control device 60 performs automatic deceleration if both the first differential pressure ΔV1 and the third differential pressure ΔV3 are continuously equal to or higher than the second straight-line threshold SF2 S. . More specifically, when the length of time (elapsed time) during which both the first differential pressure ΔV1 and the third differential pressure ΔV3 are equal to or greater than the second straight-line threshold SF2 S is equal to or greater than the second determination time, automatic deceleration is performed. . The control device 60 sets the second determination time to be shorter as the first rotation speed LM RPM and the second rotation speed RM RPM become larger, and as the first rotation speed LM RPM and the second rotation speed RM RPM become smaller, the second determination time is set shorter. Therefore, set it long.

上述した実施形態において、制御装置６０は、走行操作部材５９の操作が機体２を前進させる方向に操作され且つ左走行モータ３６Ｌ及び右走行モータ３６Ｒが機体２の後進に対応する方向に回転している場合、即ち、逆転している場合、自動減速を行わない。
制御装置６０は、左走行モータ３６Ｌの第１回転数ＬＭRPMが所定回転数以上、又は、右走行モータ３６Ｒの第２回転数ＲＭRPMが所定回転以上である場合に、自動減速を行わない。例えば、制御装置６０は、左走行モータ３６Ｌの第１回転数ＬＭRPMが左走行モータ３６Ｌの動力で回転する第１最大回転数以上である場合に自動減速を行わない。制御装置６０は、右走行モータ３６Ｒの第２回転数ＲＭRPMが右走行モータ３６Ｒの動力で回転する第２最大回転数以上である場合に自動減速を行わない。これによれば、第１回転数ＬＭRPM及び第２回転数ＲＭRPMが高い領域にあるときに、自動減速を行わないようにすることで作業性を向上させることができる。 In the embodiment described above, the control device 60 operates such that the travel operation member 59 is operated in a direction to move the aircraft 2 forward, and the left travel motor 36L and the right travel motor 36R are rotated in a direction corresponding to the backward movement of the aircraft 2. In other words, if the vehicle is in reverse, automatic deceleration is not performed.
The control device 60 does not perform automatic deceleration when the first rotation speed LM RPM of the left travel motor 36L is equal to or higher than a predetermined rotation speed, or when the second rotation speed RM RPM of the right travel motor 36R is equal to or higher than a predetermined rotation speed. For example, the control device 60 does not perform automatic deceleration when the first rotation speed LM RPM of the left travel motor 36L is equal to or higher than the first maximum rotation speed of the left travel motor 36L. The control device 60 does not perform automatic deceleration when the second rotation speed RM RPM of the right travel motor 36R is equal to or higher than the second maximum rotation speed of the right travel motor 36R. According to this, when the first rotation speed LM RPM and the second rotation speed RM RPM are in a high range, automatic deceleration is not performed, thereby improving work efficiency.

上述した実施形態では、走行操作装置５４は、操作弁５５によって走行ポンプ（第１走行ポンプ５３Ｌ，第２走行ポンプ５３Ｒ）に作用するパイロット圧を変更する油圧式であったが、図８に示すように、走行操作装置５４は、電気的に作動する装置であってもよい。
図８に示すように、走行操作装置５４は、左右方向（機体幅方向）又は前後方向に揺動する操作部材５９と、電磁比例弁から構成された操作弁５５（操作弁５５Ａ、５５Ｂ、５５Ｃ、５５Ｄ）とを備えている。制御装置６０は、操作部材５９の操作量及び操作方向を検出する操作検出センサが接続されている。制御装置６０は、操作検出センサが検出した操作量及び操作方向に基づいて、操作弁５５（操作弁５５Ａ、５５Ｂ、５５Ｃ、５５Ｄ）を制御する。 In the embodiment described above, the traveling operation device 54 is a hydraulic type that changes the pilot pressure acting on the traveling pumps (first traveling pump 53L, second traveling pump 53R) using the operating valve 55, but as shown in FIG. As such, the driving operation device 54 may be an electrically operated device.
As shown in FIG. 8, the travel operation device 54 includes an operation member 59 that swings in the left-right direction (body width direction) or the front-rear direction, and operation valves 55 (operation valves 55A, 55B, 55C) that are composed of electromagnetic proportional valves. , 55D). An operation detection sensor that detects the amount and direction of operation of the operation member 59 is connected to the control device 60 . The control device 60 controls the operation valves 55 (operation valves 55A, 55B, 55C, and 55D) based on the operation amount and operation direction detected by the operation detection sensor.

制御装置６０は、操作部材５９が前方（Ａ１方向、図１参照）に操作されると、操作弁５５Ａ及び操作弁５５Ｃに制御信号を出力し、第１走行ポンプ５３Ｌ及び第２走行ポンプ５３Ｒの斜板を正転（前進）の方向に揺動させる。
制御装置６０は、操作部材５９が後方（Ａ２方向、図１参照）に操作されると、操作弁５５Ｂ及び操作弁５５Ｄに制御信号を出力し、第１走行ポンプ５３Ｌ及び第２走行ポンプ５３Ｒの斜板を逆転（後進）の方向に揺動させる。 When the operating member 59 is operated forward (A1 direction, see FIG. 1), the control device 60 outputs a control signal to the operating valve 55A and the operating valve 55C, and controls the first traveling pump 53L and the second traveling pump 53R. Swing the swash plate in the normal (forward) direction.
When the operating member 59 is operated backward (A2 direction, see FIG. 1), the control device 60 outputs a control signal to the operating valve 55B and the operating valve 55D, and controls the first traveling pump 53L and the second traveling pump 53R. Swing the swash plate in the reverse (reverse) direction.

制御装置６０は、操作部材５９が右方（Ａ３方向、図１参照）に操作されると、操作弁５５Ａ及び操作弁５５Ｄに制御信号を出力し、第１走行ポンプ５３Ｌの斜板を正転の方向に揺動させ、第２走行ポンプ５３Ｒの斜板を逆転の方向に揺動させる。
制御装置６０は、操作部材５９が左方（Ａ４方向、図１参照）に操作されると、操作弁５５Ｂ及び操作弁５５Ｃに制御信号を出力し、第１走行ポンプ５３Ｌの斜板を逆転の方向に揺動させ、第２走行ポンプ５３Ｒの斜板を正転の方向に揺動させる。 When the operating member 59 is operated to the right (A3 direction, see FIG. 1), the control device 60 outputs a control signal to the operating valve 55A and the operating valve 55D, and causes the swash plate of the first traveling pump 53L to rotate in the normal direction. The swash plate of the second traveling pump 53R is swung in the reverse direction.
When the operating member 59 is operated to the left (direction A4, see FIG. 1), the control device 60 outputs a control signal to the operating valve 55B and the operating valve 55C, and rotates the swash plate of the first traveling pump 53L in the reverse direction. The swash plate of the second traveling pump 53R is swung in the direction of normal rotation.

作業機１は、機体２と、機体２の左側に設けられた左走行装置５Ｌと、機体２の右側に設けられた右走行装置５Ｒと、左走行装置５Ｌに動力を伝達可能な左走行モータ３６Ｌと、右走行装置５Ｒに動力を伝達可能な右走行モータ３６Ｒと、左走行モータ３６Ｌの第１回転数ＬＭRPMを検出する第１回転検出装置６８ａと、右走行モータ３６Ｒの第２回転数ＲＭRPMを検出する第２回転検出装置６８ｂと、作動油を受圧する第１受圧部５３ａ及び第２受圧部５３ｂを有し且つ、少なくとも第１受圧部５３ａ及び第２受圧部５３ｂのいずれかに作動油が作用したときに左走行モータ３６Ｌに作動油を供給する左走行ポンプ５３Ｌと、作動油を受圧する第３受圧部５３ａ及び第４受圧部５３ｂを有し且つ、少なくとも第３受圧部５３ａ及び第４受圧部５３ｂのいずれかに作動油が作用したときに右走行モータ３６Ｒに作動油を供給する右走行ポンプ５３Ｒと、走行操作部材５９を操作したときに、少なくとも第１受圧部５３ａ、第２受圧部５３ｂ、第３受圧部５３ａ及び第４受圧部５３ｂのいずれかに作動油を作用させる走行操作装置５４と、左走行モータ３６Ｌ及び右走行モータ３６Ｒが第２速度である場合に、第２速度から第１速度に自動的に減速する自動減速を行う制御装置６０と、を備え、制御装置６０は、右走行モータ３６Ｒの第２回転数ＲＭRPMに基づいて自動減速の減速閾値として機体２が左方向へ信地旋回する場合の左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）を設定し、自動減速の減速閾値として左走行モータ３６Ｌの第１回転数ＬＭRPMに基づいて機体２が右方向へ信地旋回する場合の右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を設定する。 The work machine 1 includes a body 2, a left traveling device 5L provided on the left side of the body 2, a right traveling device 5R provided on the right side of the body 2, and a left traveling motor capable of transmitting power to the left traveling device 5L. 36L, a right travel motor 36R capable of transmitting power to the right travel device 5R, a first rotation detection device 68a that detects the first rotation speed LM RPM of the left travel motor 36L, and a second rotation speed of the right travel motor 36R. It has a second rotation detection device 68b that detects RM RPM , a first pressure receiving part 53a and a second pressure receiving part 53b that receive pressure of hydraulic oil, and at least one of the first pressure receiving part 53a and the second pressure receiving part 53b It has a left traveling pump 53L that supplies hydraulic oil to the left traveling motor 36L when the hydraulic oil is applied, and a third pressure receiving part 53a and a fourth pressure receiving part 53b that receive pressure of the hydraulic oil, and at least the third pressure receiving part 53a. and a right travel pump 53R that supplies hydraulic oil to the right travel motor 36R when hydraulic oil acts on either of the fourth pressure receiving portions 53b, and at least the first pressure receiving portion 53a when the travel operation member 59 is operated. When the travel operation device 54 applies hydraulic oil to any of the second pressure receiving portion 53b, the third pressure receiving portion 53a, and the fourth pressure receiving portion 53b, and the left travel motor 36L and the right travel motor 36R are at the second speed, a control device 60 that performs automatic deceleration to automatically decelerate from the second speed to the first speed ; The left threshold (first left threshold ST1 L , second left threshold ST2 L ) when the aircraft 2 makes a left turn is set, and the first rotation speed LM RPM of the left travel motor 36L is set as the deceleration threshold for automatic deceleration. Based on this, right threshold values (first right threshold value ST1 R , second right threshold value ST2 R ) are set when the aircraft 2 makes a pivot turn to the right.

これによれば、例えば、左方向へ信地旋回した場合は、左走行モータ３６Ｌの第１回転数ＬＭRPMに比べて右走行モータ３６Ｒの第２回転数ＲＭRPMが速く、右方向へ信地旋回した場合は、右走行モータ３６Ｒの第２回転数ＲＭRPMに比べて左走行モータ３６Ｌの第１回転数ＬＭRPMが速くなる。つまり、旋回方向に対して、反対側の走行モータの回転数が速くなることから、当該走行モータの回転数に基づいて、自動減速の減速閾値（左閾値、右閾値）を設定することにより、左方向への信地旋回時又は右方向への信地旋回時に対応した自動減速をスムーズに行うことができる。言い換えれば、左方向への信地旋回時又は右方向への信地旋回時に不用意に自動減速をしてしまうことを防止することができ、必要な時だけ、自動減速を行うことができる。 According to this, for example, when a turn is made to the left, the second rotation speed RM RPM of the right travel motor 36R is faster than the first rotation speed LM RPM of the left travel motor 36L, and the turn is made to the right. When turning, the first rotation speed LM RPM of the left travel motor 36L becomes faster than the second rotation speed RM RPM of the right travel motor 36R. In other words, since the rotation speed of the travel motor on the opposite side to the turning direction becomes faster, by setting the deceleration thresholds (left threshold, right threshold) for automatic deceleration based on the rotation speed of the travel motor, Automatic deceleration corresponding to when turning to the left or turning to the right can be smoothly performed. In other words, it is possible to prevent automatic deceleration from being inadvertently performed when turning to the left or to the right, and automatic deceleration can be performed only when necessary.

制御装置６０は、第２回転数ＲＭRPMが低くなるにつれて左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）を低く、第２回転数ＲＭRPMが高くなるにつれて左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）を高く、第１回転数ＬＭRPMが低くなるにつれて右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を低く、第１回転数ＬＭRPMが高くなるにつれて右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を高くする。 The control device 60 lowers the left threshold value (first left threshold value ST1 L , second left threshold value ST2 L ) as the second rotation speed RM RPM becomes lower, and lowers the left threshold value (first left threshold value ST2 L ) as the second rotation speed RM RPM increases. The left threshold ST1 L , second left threshold ST2 L ) are set high, and the first rotation speed LM As RPM becomes lower, the right threshold (first right threshold ST1 R , second right threshold ST2 R ) is lowered, and the first rotation speed LM As the RPM increases, the right thresholds (first right threshold ST1 R , second right threshold ST2 R ) are increased.

これによれば、左方向への信地旋回時又は右方向への信地旋回時に対応した自動減速をスムーズに行うことができる。言い換えれば、左方向への信地旋回時又は右方向への信地旋回時に不用意に自動減速をしてしまうことを抑制することができ、必要な時だけ、自動減速を行うことができる。
作業機１は、左走行ポンプ５３Ｌと左走行モータ３６Ｌとを接続する第１循環油路５７ｈと、右走行ポンプ５３Ｒと右走行モータ３６Ｒとを接続する第２循環油路５７ｉと、左走行モータ３６Ｌの第１ポートＰ１１側に設けられ且つ左走行モータ３６Ｌの回転時の第１循環油路５７ｈに作用する作動油の圧力を第１走行圧Ｖ１として検出する第１圧力検出装置８０ａと、左走行モータ３６Ｌの第２ポートＰ１２側に設けられ且つ左走行モータ３６Ｌの回転時の第１循環油路５７ｈに作用する作動油の圧力を第２走行圧Ｖ２として検出する第２圧力検出装置８０ｂと、右走行モータ３６Ｒの第３ポートＰ１３側に設けられ且つ右走行モータ３６Ｒの回転時の第２循環油路５７ｉに作用する作動油の圧力を第３走行圧Ｖ３として検出する第３圧力検出装置８０ｃと、右走行モータ３６Ｒの第４ポートＰ１４側に設けられ且つ右走行モータ３６Ｒの回転時の第２循環油路５７ｉに作用する作動油の圧力を第４走行圧Ｖ４として検出する第４圧力検出装置８０ｄと、を備え、制御装置６０は、機体２が左方向へ信地旋回する場合には、第３走行圧Ｖ３又は第４走行圧Ｖ４が左閾値（第１左閾値ＳＴ１L）以上であるときに自動減速を行い、機体２が右方向へ信地旋回する場合には、第１走行圧Ｖ１又は第２走行圧Ｖ２が右閾値（第１右閾値ＳＴ１R）以上であるときに自動減速を行う。 According to this, it is possible to smoothly perform automatic deceleration corresponding to a pivot turn to the left or a pivot turn to the right. In other words, it is possible to prevent inadvertent automatic deceleration during a pivot turn to the left or to the right, and automatic deceleration can be performed only when necessary.
The work equipment 1 has a first circulation oil passage 57h that connects the left running pump 53L and the left running motor 36L, a second circulation oil passage 57i that connects the right running pump 53R and the right running motor 36R, and a left running motor. A first pressure detection device 80a is provided on the first port P11 side of the left travel motor 36L and detects the pressure of the hydraulic oil acting on the first circulation oil path 57h when the left travel motor 36L is rotated as the first travel pressure V1; a second pressure detection device 80b that is provided on the second port P12 side of the travel motor 36L and detects the pressure of the hydraulic oil acting on the first circulation oil path 57h when the left travel motor 36L rotates as a second travel pressure V2; , a third pressure detection device that is provided on the third port P13 side of the right travel motor 36R and detects the pressure of the hydraulic oil acting on the second circulation oil path 57i when the right travel motor 36R rotates as a third travel pressure V3. 80c, and a fourth pressure that is provided on the fourth port P14 side of the right travel motor 36R and detects the pressure of the hydraulic oil acting on the second circulation oil passage 57i when the right travel motor 36R rotates as the fourth travel pressure V4. and a detection device 80d, and the control device 60 determines that when the aircraft 2 makes a left turn, the third running pressure V3 or the fourth running pressure V4 is equal to or higher than the left threshold (first left threshold ST1 L ). When automatic deceleration is performed and the aircraft 2 makes a turn to the right, when the first running pressure V1 or the second running pressure V2 is equal to or higher than the right threshold (first right threshold ST1 R ) Perform automatic deceleration.

これによれば、機体２が左方向へ信地旋回をしたときは、右走行モータ３６Ｒに対応する走行圧（第３走行圧Ｖ３、第４走行圧Ｖ４）が左閾値（第１左閾値ＳＴ１L）以上であるときに自動減速を行うことができ、機体２が右方向へ信地旋回をしたときは、左走行モータ３６Ｌに対応する走行圧（第１走行圧Ｖ１、第２走行圧Ｖ２）が左閾値（第１右閾値ＳＴ１R）以上であるときに自動減速を行うことができる。 According to this, when the aircraft 2 makes a pivot turn to the left, the running pressure (third running pressure V3, fourth running pressure V4) corresponding to the right running motor 36R becomes the left threshold (first left threshold ST1). L ) or above, automatic deceleration can be performed, and when the aircraft 2 makes a turn to the right, the running pressure (first running pressure V1, second running pressure V2) corresponding to the left running motor 36L ) is greater than or equal to the left threshold (first right threshold ST1 R ), automatic deceleration can be performed.

制御装置６０は、機体２が左方向へ信地旋回する場合には、第３走行圧Ｖ３から第４走行圧Ｖ４を減算した第３差圧ΔＶ３、又は、第４走行圧Ｖ４から第３走行圧Ｖ３を減算した第４差圧ΔＶ４が左閾値（第２左閾値ＳＴ２L）以上であるときに自動減速を行い、機体２が右方向へ信地旋回する場合には、第１走行圧Ｖ１から第２走行圧Ｖ２を減算した第１差圧ΔＶ１、又は、第２走行圧Ｖ２から第１走行圧Ｖ１を減算した第２差圧ΔＶ２が右閾値（第２右閾値ＳＴ２R）以上であるときに自動減速を行う。 When the aircraft 2 makes a pivot turn to the left, the control device 60 uses a third differential pressure ΔV3 obtained by subtracting the fourth running pressure V4 from the third running pressure V3, or a third running pressure ΔV3 obtained by subtracting the fourth running pressure V4 from the fourth running pressure V4. When automatic deceleration is performed when the fourth differential pressure ΔV4 obtained by subtracting the pressure V3 is equal to or higher than the left threshold value (second left threshold value ST2 L ), and the aircraft 2 makes a turn to the right, the first running pressure V1 The first differential pressure ΔV1 obtained by subtracting the second running pressure V2 from the second running pressure V2 or the second differential pressure ΔV2 obtained by subtracting the first running pressure V1 from the second running pressure V2 is greater than or equal to the right threshold (second right threshold ST2 R ). Sometimes automatic deceleration is performed.

これによれば、機体２が左方向へ信地旋回をしたときは、右走行モータ３６Ｒに対応する有効の走行圧（第３差圧ΔＶ３、第４差圧ΔＶ４）が左閾値（第２左閾値ＳＴ２L）以上であるときに自動減速を行うことができ、機体２が右方向へ信地旋回をしたときは、左走行モータ３６Ｌに対応する有効の走行圧（第１差圧ΔＶ１、第２差圧ΔＶ２）が左閾値（第２右閾値ＳＴ２R）以上であるときに自動減速を行うことができる。 According to this, when the aircraft 2 makes a pivot turn to the left, the effective running pressure (third differential pressure ΔV3, fourth differential pressure ΔV4) corresponding to the right running motor 36R becomes the left threshold value (second left Automatic deceleration can be performed when the threshold value ST2 L ) or more is exceeded, and when the aircraft 2 makes a pivot turn to the right, the effective running pressure (first differential pressure ΔV1, first differential pressure ΔV1, Automatic deceleration can be performed when the second differential pressure ΔV2) is greater than or equal to the left threshold (second right threshold ST2 R ).

制御装置６０は、原動機の回転数に応じて左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）及び右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）を変更する。これによれば、原動機の負荷によって変化する原動機の回転数に応じて、左閾値、右閾値を変更することができるため、負荷に応じた自動減速を行うことができる。
制御装置６０は、左走行モータ３６Ｌの第１回転数ＬＭRPMと右走行モータ３６Ｒの第２回転数ＲＭRPMとのうち、速い方の回転数に応じて超信地閾値（第１超信地閾値ＳＴ１P、第２超信地閾値ＳＴ２P）を設定する。これによれば、超信地旋回を行っている場合に回転差が生じたときには、必要なときに自動減速を行うことができる。 The control device 60 changes the left threshold (first left threshold ST1 L , second left threshold ST2 L ) and right threshold (first right threshold ST1 R , second right threshold ST2 R ) according to the rotation speed of the prime mover. . According to this, the left threshold value and the right threshold value can be changed according to the rotation speed of the prime mover, which changes depending on the load on the prime mover, so that automatic deceleration can be performed according to the load.
The control device 60 sets a super confidence threshold (a first super confidence threshold) according to the faster rotation speed of the first rotation speed LM RPM of the left travel motor 36L and the second rotation speed RM RPM of the right travel motor 36R. A threshold value ST1 P and a second super-strength threshold value ST2 P ) are set. According to this, when a rotation difference occurs during a super pivot turn, automatic deceleration can be performed when necessary.

制御装置６０は、機体２が超信地旋回する場合に自動減速の減速閾値として、左閾値（第１左閾値ＳＴ１L、第２左閾値ＳＴ２L）及び右閾値（第１右閾値ＳＴ１R、第２右閾値ＳＴ２R）よりも低い超信地閾値（第１超信地閾値ＳＴ１P、第２超信地閾値ＳＴ２P）を設定する。これによれば、超信地旋回をした場合に、必要な時にスムーズに自動減速を行うことができる。 The control device 60 sets a left threshold (first left threshold ST1 L , second left threshold ST2 L ) and a right threshold (first right threshold ST1 R , The super-position thresholds (first super-position threshold ST1 P , second super-position threshold ST2 P ) lower than the second right-hand threshold ST2 R ) are set. According to this, when the vehicle makes a sharp turn, automatic deceleration can be smoothly performed when necessary.

制御装置６０は、機体２が超信地旋回する場合に、第１走行圧Ｖ１、第２走行圧Ｖ２、第３走行圧Ｖ３、第４走行圧Ｖ４のいずれかが、超信地閾値（第１超信地閾値ＳＴ１P）以上であるときに自動減速を行う。これによれば、第１走行圧Ｖ１、第２走行圧Ｖ２、第３走行圧Ｖ３、第４走行圧Ｖ４の圧力に応じて、超信地旋回時に自動減速を行うか否かを判断することができ、第１走行圧Ｖ１、第２走行圧Ｖ２、第３走行圧Ｖ３、第４走行圧Ｖ４のいずれかが、超信地閾値（第１超信地閾値ＳＴ１P）以上のときだけ、自動減速を行うことができる。 The control device 60 is configured such that when the aircraft 2 makes a super turning turn, any one of the first running pressure V1, the second running pressure V2, the third running pressure V3, and the fourth running pressure V4 reaches a super turning pressure (a super turning pressure). Automatic deceleration is performed when the value is equal to or higher than the 1-super-strength threshold ST1 P ). According to this, it is determined whether or not to perform automatic deceleration during a corner turn, depending on the pressures of the first running pressure V1, the second running pressure V2, the third running pressure V3, and the fourth running pressure V4. is possible, and only when any one of the first running pressure V1, second running pressure V2, third running pressure V3, and fourth running pressure V4 is equal to or higher than the super-stability threshold (first super-stability threshold ST1 P ), Automatic deceleration can be performed.

制御装置６０は、機体２が超信地旋回する場合に、第１走行圧Ｖ１から第２走行圧Ｖ２を減算した第１差圧ΔＶ１、第２走行圧Ｖ２から第１走行圧Ｖ１を減算した第２差圧ΔＶ２、第３走行圧Ｖ３から第４走行圧Ｖ４を減算した第３差圧ΔＶ３、第４走行圧Ｖ４から第３走行圧Ｖ３を減算した第４差圧ΔＶ４のいずれかが超信地閾値（第２超信地閾値ＳＴ２P）以上であるときに自動減速を行う。これによれば、第１差圧ΔＶ１、第２差圧ΔＶ２、第３差圧ΔＶ３、第４差圧ΔＶ４の圧力に応じて、超信地旋回時に自動減速を行うか否かを判断することができ、第１差圧ΔＶ１、第２差圧ΔＶ２、第３差圧ΔＶ３、第４差圧ΔＶ４のいずれかが超信地閾値（第２超信地閾値ＳＴ２P）以上のときだけ、自動減速を行うことができる。 When the aircraft 2 makes a sharp turn, the control device 60 subtracts the first running pressure V1 from the first running pressure V1, and subtracts the first running pressure V1 from the second running pressure V2. If any of the second differential pressure ΔV2, the third differential pressure ΔV3 obtained by subtracting the fourth running pressure V4 from the third running pressure V3, or the fourth differential pressure ΔV4 obtained by subtracting the third running pressure V3 from the fourth running pressure V4 exceeds Automatic deceleration is performed when the position is equal to or higher than the position threshold (second position threshold ST2 P ). According to this, it is determined whether or not to perform automatic deceleration during a super turn, depending on the pressures of the first differential pressure ΔV1, the second differential pressure ΔV2, the third differential pressure ΔV3, and the fourth differential pressure ΔV4. is automatically activated only when any of the first differential pressure ΔV1, second differential pressure ΔV2, third differential pressure ΔV3, and fourth differential pressure ΔV4 is greater than or equal to the super confidence threshold (second super confidence threshold ST2 P ). Can be decelerated.

作業機１は、機体２と、機体２の左側に設けられた左走行装置５Ｌと、機体２の右側に設けられた右走行装置５Ｒと、左走行装置５Ｌに動力を伝達可能な左走行モータ３６Ｌと、右走行装置５Ｒに動力を伝達可能な右走行モータ３６Ｒと、左走行モータ３６Ｌの第１回転数ＬＭRPMを検出する第１回転検出装置６８ａと、右走行モータ３６Ｒの第２回転数ＲＭRPMを検出する第２回転検出装置６８ｂと、作動油を受圧する第１受圧部５３ａ及び第２受圧部５３ｂを有し且つ、少なくとも第１受圧部５３ａ及び第２受圧部５３ｂのいずれかに作動油が作用したときに左走行モータ３６Ｌに作動油を供給する左走行ポンプ５３Ｌと、作動油を受圧する第３受圧部５３ａ及び第４受圧部５３ｂを有し且つ、少なくとも第３受圧部５３ａ及び第４受圧部５３ｂのいずれかに作動油が作用したときに右走行モータ３６Ｒに作動油を供給する右走行ポンプ５３Ｒと、走行操作部材５９を操作したときに、少なくとも第１受圧部５３ａ、第２受圧部５３ｂ、第３受圧部５３ａ及び第４受圧部５３ｂのいずれかに作動油を作用させる走行操作装置５４と、左走行モータ３６Ｌ及び右走行モータ３６Ｒが第２速度である場合に、第２速度から第１速度に自動的に減速する自動減速を行う制御装置６０と、を備え、制御装置６０は、第１回転検出装置６８ａが検出した第１回転数ＬＭRPMと第２回転検出装置６８ｂが検出した第２回転数ＲＭRPMとの回転差ΔＭＰ又は回転比率の比率差ΔＤＰに基づいて、自動減速を行う減速閾値として、機体２が直進する場合の直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を設定する。例えば、機体２が信地旋回である状態から直進状態に移行するときには、第１回転数ＬＭRPMと第２回転数ＲＭRPMとに差が生じてしまうことになるため、このようなときは、回転差ΔＭＰ又は回転比率の比率差ΔＤＰによって直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を設定することによって、機体２を第２速度の状態に維持することができる。つまり、機体２が信地旋回である状態から直進状態に移行するときは、自動減速を行わずに、機体２の直進が安定したときに、必要に応じて自動減速を行うことができる。 The work machine 1 includes a body 2, a left traveling device 5L provided on the left side of the body 2, a right traveling device 5R provided on the right side of the body 2, and a left traveling motor capable of transmitting power to the left traveling device 5L. 36L, a right travel motor 36R capable of transmitting power to the right travel device 5R, a first rotation detection device 68a that detects the first rotation speed LM RPM of the left travel motor 36L, and a second rotation speed of the right travel motor 36R. It has a second rotation detection device 68b that detects RM RPM , a first pressure receiving part 53a and a second pressure receiving part 53b that receive pressure of hydraulic oil, and at least one of the first pressure receiving part 53a and the second pressure receiving part 53b It has a left traveling pump 53L that supplies hydraulic oil to the left traveling motor 36L when the hydraulic oil is applied, and a third pressure receiving part 53a and a fourth pressure receiving part 53b that receive pressure of the hydraulic oil, and at least the third pressure receiving part 53a. and a right travel pump 53R that supplies hydraulic oil to the right travel motor 36R when hydraulic oil acts on either of the fourth pressure receiving portions 53b, and at least the first pressure receiving portion 53a when the travel operation member 59 is operated. When the travel operation device 54 applies hydraulic oil to any of the second pressure receiving portion 53b, the third pressure receiving portion 53a, and the fourth pressure receiving portion 53b, and the left travel motor 36L and the right travel motor 36R are at the second speed, A control device 60 that automatically decelerates from the second speed to the first speed, and the control device 60 detects the first rotation speed LM RPM detected by the first rotation detection device 68a and the second rotation speed. Based on the rotation difference ΔMP with the second rotation speed RM RPM or the rotation ratio ratio difference ΔDP detected by the device 68b, the straight-line threshold when the aircraft 2 moves straight (first straight-line threshold SF1) is used as the deceleration threshold for automatic deceleration. S , the second straight-line threshold SF2 S ) is set. For example, when the aircraft 2 transitions from a turning state to a straight-ahead state, there will be a difference between the first rotational speed LM RPM and the second rotational speed RM RPM , so in such a case, By setting the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) based on the rotational difference ΔMP or the rotation ratio ratio difference ΔDP, the aircraft 2 can be maintained at the second speed. In other words, when the aircraft 2 shifts from a turning state to a straight-ahead state, automatic deceleration is not performed, but automatic deceleration can be performed as necessary when the straight-ahead movement of the aircraft 2 is stabilized.

制御装置６０は、回転差ΔＭＰが大きくなるにつれて直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を高く、回転差ΔＭＰが小さくなるにつれて直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を低く設定する。これによれば、信地旋回の状態に近いとき（回転差ΔＭＰが大きいとき）には、自動減速を行い難くして、直進の状態に近いとき（回転差ΔＭＰが小さいとき）には、自動減速を行い易くすることができる。 The control device 60 increases the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) as the rotation difference ΔMP increases, and increases the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF1 S ) as the rotation difference ΔMP decreases. 2 straight-ahead threshold value SF2 S ) is set low. According to this, automatic deceleration is made difficult to perform when the state is close to a pivot turn (when the rotational difference ΔMP is large), and automatic deceleration is made difficult when the state is close to a straight-ahead turning state (when the rotational difference ΔMP is small). This makes it easier to decelerate.

制御装置６０は、回転比率の比率差ΔＤＰが大きくなるにつれて直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を高く、回転比率の比率差ΔＤＰが小さくなるにつれて直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を低く設定する。これによれば、信地旋回の状態に近いとき（比率差ΔＤＰが大きいとき）には、自動減速を行い難くして、直進の状態に近いとき（比率差ΔＤＰが小さいとき）には、自動減速を行い易くすることができる。 The control device 60 increases the straight-line threshold (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) as the rotation ratio difference ΔDP increases, and increases the straight-line threshold (first straight-line threshold SF1 S ) as the rotation ratio difference ΔDP decreases. The straight-line threshold SF1 S and the second straight-line threshold SF2 S are set low. According to this, automatic deceleration is made difficult to perform when the state is close to a pivot turn (when the ratio difference ΔDP is large), and automatic deceleration is made difficult when the state is close to a straight-ahead situation (when the ratio difference ΔDP is small). This makes it easier to decelerate.

作業機１は、左走行ポンプ５３Ｌと左走行モータ３６Ｌとを接続する第１循環油路５７ｈと、右走行ポンプ５３Ｒと右走行モータ３６Ｒとを接続する第２循環油路５７ｉと、左走行モータ３６Ｌの第１ポートＰ１１側に設けられ且つ左走行モータ３６Ｌの回転時の第１循環油路５７ｈに作用する作動油の圧力を第１走行圧Ｖ１として検出する第１圧力検出装置８０ａと、左走行モータ３６Ｌの第２ポートＰ１２側に設けられ且つ左走行モータ３６Ｌの回転時の第１循環油路５７ｈに作用する作動油の圧力を第２走行圧Ｖ２として検出する第２圧力検出装置８０ｂと、右走行モータ３６Ｒの第３ポートＰ１３側に設けられ且つ右走行モータ３６Ｒの回転時の第２循環油路５７ｉに作用する作動油の圧力を第３走行圧Ｖ３として検出する第３圧力検出装置８０ｃと、右走行モータ３６Ｒの第４ポートＰ１４側に設けられ且つ右走行モータ３６Ｒの回転時の第２循環油路５７ｉに作用する作動油の圧力を第４走行圧Ｖ４として検出する第４圧力検出装置８０ｄと、を備え、制御装置６０は、機体２が直進であって前進する場合は、第１走行圧Ｖ１及び第３走行圧Ｖ３のいずれかが直進閾値（第１直進閾値ＳＦ１S）以上であるとき、自動減速を行う。これによれば、機体２が前進したときは、左走行モータ３６Ｌに対応する走行圧（第１走行圧Ｖ１）と、右走行モータ３６Ｒに対応する走行圧（第３走行圧Ｖ３）とによって、直進閾値（第１直進閾値ＳＦ１S）以上であるときに、自動減速を行うことができる。 The work equipment 1 has a first circulation oil passage 57h that connects the left running pump 53L and the left running motor 36L, a second circulation oil passage 57i that connects the right running pump 53R and the right running motor 36R, and a left running motor. A first pressure detection device 80a is provided on the first port P11 side of the left travel motor 36L and detects the pressure of the hydraulic oil acting on the first circulation oil path 57h when the left travel motor 36L is rotated as the first travel pressure V1; a second pressure detection device 80b that is provided on the second port P12 side of the travel motor 36L and detects the pressure of the hydraulic oil acting on the first circulation oil path 57h when the left travel motor 36L rotates as a second travel pressure V2; , a third pressure detection device that is provided on the third port P13 side of the right travel motor 36R and detects the pressure of the hydraulic oil acting on the second circulation oil path 57i when the right travel motor 36R rotates as a third travel pressure V3. 80c, and a fourth pressure that is provided on the fourth port P14 side of the right travel motor 36R and detects the pressure of the hydraulic oil acting on the second circulation oil passage 57i when the right travel motor 36R rotates as the fourth travel pressure V4. A detection device 80d is provided, and the control device 60 determines that when the aircraft 2 is traveling straight and moving forward, either the first traveling pressure V1 or the third traveling pressure V3 is a straight traveling threshold (first straight traveling threshold SF1 S ). When this is the case, automatic deceleration is performed. According to this, when the aircraft body 2 moves forward, the running pressure corresponding to the left running motor 36L (first running pressure V1) and the running pressure corresponding to the right running motor 36R (third running pressure V3), Automatic deceleration can be performed when the speed is equal to or higher than the straight-line threshold (first straight-line threshold SF1 S ).

制御装置６０は、機体２が直進であって前進する場合は、第１走行圧Ｖ１から第２走行圧Ｖ２を減算した第１差圧ΔＶ１及び第３走行圧Ｖ３から第４走行圧Ｖ４を減算した第３差圧ΔＶ３のいずれかが直進閾値（第２直進閾値ＳＦ２S）以上であるとき、自動減速を行う。これによれば、機体２が前進したときは、左走行モータ３６Ｌに対応する有効の走行圧（第１差圧ΔＶ１）と、右走行モータ３６Ｒに対応する有効の走行圧（第３差圧ΔＶ３）とによって、直進閾値（第２直進閾値ＳＦ２S）以上であるときに、自動減速を行うことができる。 When the aircraft 2 is moving straight ahead, the control device 60 subtracts the first differential pressure ΔV1, which is obtained by subtracting the second running pressure V2 from the first running pressure V1, and the fourth running pressure V4 from the third running pressure V3. When either of the third differential pressures ΔV3 is equal to or higher than the straight-line threshold (second straight-line threshold SF2 S ), automatic deceleration is performed. According to this, when the aircraft body 2 moves forward, the effective running pressure (first differential pressure ΔV1) corresponding to the left running motor 36L and the effective running pressure (third differential pressure ΔV3) corresponding to the right running motor 36R are applied. ), it is possible to perform automatic deceleration when the speed is equal to or higher than the straight-line threshold (second straight-line threshold SF2 S ).

作業機１は、機体２と、機体２の左側に設けられた左走行装置５Ｌと、機体２の右側に設けられた右走行装置５Ｒと、左走行装置５Ｌに動力を伝達可能な左走行モータ３６Ｌと、右走行装置５Ｒに動力を伝達可能な右走行モータ３６Ｒと、左走行モータ３６Ｌの第１回転数ＬＭRPMを検出する第１回転検出装置６８ａと、右走行モータ３６Ｒの第２回転数ＲＭRPMを検出する第２回転検出装置６８ｂと、作動油を受圧する第１受圧部５３ａ及び第２受圧部５３ｂを有し且つ、少なくとも第１受圧部５３ａ及び第２受圧部５３ｂのいずれかに作動油が作用したときに左走行モータ３６Ｌに作動油を供給する左走行ポンプ５３Ｌと、作動油を受圧する第３受圧部５３ａ及び第４受圧部５３ｂを有し且つ、少なくとも第３受圧部５３ａ及び第４受圧部５３ｂのいずれかに作動油が作用したときに右走行モータ３６Ｒに作動油を供給する右走行ポンプ５３Ｒと、走行操作部材５９を操作したときに、少なくとも第１受圧部５３ａ、第２受圧部５３ｂ、第３受圧部５３ａ及び第４受圧部５３ｂのいずれかに作動油を作用させる走行操作装置５４と、左走行モータ３６Ｌ及び右走行モータ３６Ｒが第２速度である場合に、第２速度から第１速度に自動的に減速する自動減速を行う制御装置６０と、を備え、制御装置６０は、第１回転検出装置６８ａが検出した第１回転数ＬＭRPM、第２回転検出装置６８ｂが検出した第２回転数ＲＭRPMと基づいて、自動減速を行う減速閾値として、機体２が直進する場合の直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を設定する。 The work machine 1 includes a body 2, a left traveling device 5L provided on the left side of the body 2, a right traveling device 5R provided on the right side of the body 2, and a left traveling motor capable of transmitting power to the left traveling device 5L. 36L, a right travel motor 36R capable of transmitting power to the right travel device 5R, a first rotation detection device 68a that detects the first rotation speed LM RPM of the left travel motor 36L, and a second rotation speed of the right travel motor 36R. It has a second rotation detection device 68b that detects RM RPM , a first pressure receiving part 53a and a second pressure receiving part 53b that receive pressure of hydraulic oil, and at least one of the first pressure receiving part 53a and the second pressure receiving part 53b It has a left traveling pump 53L that supplies hydraulic oil to the left traveling motor 36L when the hydraulic oil is applied, and a third pressure receiving part 53a and a fourth pressure receiving part 53b that receive pressure of the hydraulic oil, and at least the third pressure receiving part 53a. and a right travel pump 53R that supplies hydraulic oil to the right travel motor 36R when hydraulic oil acts on either of the fourth pressure receiving portions 53b, and at least the first pressure receiving portion 53a when the travel operation member 59 is operated. When the travel operation device 54 applies hydraulic oil to any of the second pressure receiving portion 53b, the third pressure receiving portion 53a, and the fourth pressure receiving portion 53b, and the left travel motor 36L and the right travel motor 36R are at the second speed, A control device 60 that performs automatic deceleration to automatically decelerate from a second speed to a first speed, and the control device 60 detects the first rotation speed LM RPM detected by the first rotation detection device 68a and the second rotation speed. Based on the second rotational speed RM RPM detected by the device 68b, straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) when the aircraft 2 moves straight are set as deceleration thresholds for automatic deceleration. .

例えば、機体２の車速が低い状態から加速したとき、機体２が停止した状態から加速したときなど、左走行モータ３６Ｌの第１回転数ＬＭRPM及び右走行モータ３６Ｒの第２回転数ＲＭRPMが上昇することになる（高くなる）。このような場合は、自動減速が行われることを抑制しつつ、機体２の直進が安定したときに、自動減速を行うことができる。
制御装置６０は、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが小さい場合は直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を低く、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが大きい場合は直進閾値（第１直進閾値ＳＦ１S、第２直進閾値ＳＦ２S）を高く設定する。 For example, when the vehicle speed of the aircraft 2 is accelerated from a low state or when the aircraft 2 is accelerated from a stopped state, the first rotation speed LM RPM of the left travel motor 36L and the second rotation speed RM RPM of the right travel motor 36R are It will rise (become higher). In such a case, automatic deceleration can be performed when the straight ahead movement of the aircraft 2 is stabilized while suppressing automatic deceleration from being performed.
When the first rotation speed LM RPM or the second rotation speed RM RPM is small, the control device 60 sets the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) low, and sets the first rotation speed LM RPM or the second rotation speed RM RPM to a low value. When the second rotation speed RM RPM is large, the straight-line thresholds (first straight-line threshold SF1 S , second straight-line threshold SF2 S ) are set high.

これによれば、機体２の車速が低い状態から加速したとき、機体２が停止した状態から加速したときなどに、自動減速が行われることを抑制しつつ、機体２の直進が安定したときに、自動減速を行うことができる。
作業機１は、左走行ポンプ５３Ｌと左走行モータ３６Ｌとを接続する第１循環油路５７ｈと、右走行ポンプ５３Ｒと右走行モータ３６Ｒとを接続する第２循環油路５７ｉと、左走行モータ３６Ｌの第１ポートＰ１１側に設けられ且つ左走行モータ３６Ｌの回転時の第１循環油路５７ｈに作用する作動油の圧力を第１走行圧Ｖ１として検出する第１圧力検出装置８０ａと、左走行モータ３６Ｌの第２ポートＰ１２側に設けられ且つ左走行モータ３６Ｌの回転時の第１循環油路５７ｈに作用する作動油の圧力を第２走行圧Ｖ２として検出する第２圧力検出装置８０ｂと、右走行モータ３６Ｒの第３ポートＰ１３側に設けられ且つ右走行モータ３６Ｒの回転時の第２循環油路５７ｉに作用する作動油の圧力を第３走行圧Ｖ３として検出する第３圧力検出装置８０ｃと、右走行モータ３６Ｒの第４ポートＰ１４側に設けられ且つ右走行モータ３６Ｒの回転時の第２循環油路５７ｉに作用する作動油の圧力を第４走行圧Ｖ４として検出する第４圧力検出装置８０ｄと、を備え、制御装置６０は、機体２が直進であって前進する場合は、第１走行圧Ｖ１と第３走行圧Ｖ３との両方が直進閾値（第１直進閾値ＳＦ１S）以上である時間が第１判定時間以上であるとき、自動減速を行う。 According to this, automatic deceleration is suppressed when the aircraft 2 accelerates from a low vehicle speed or when the aircraft 2 accelerates from a stopped state, and when the aircraft 2 stabilizes in a straight line. , can perform automatic deceleration.
The work equipment 1 has a first circulation oil passage 57h that connects the left running pump 53L and the left running motor 36L, a second circulation oil passage 57i that connects the right running pump 53R and the right running motor 36R, and a left running motor. A first pressure detection device 80a is provided on the first port P11 side of the left travel motor 36L and detects the pressure of the hydraulic oil acting on the first circulation oil path 57h when the left travel motor 36L is rotated as the first travel pressure V1; a second pressure detection device 80b that is provided on the second port P12 side of the travel motor 36L and detects the pressure of the hydraulic oil acting on the first circulation oil path 57h when the left travel motor 36L rotates as a second travel pressure V2; , a third pressure detection device that is provided on the third port P13 side of the right travel motor 36R and detects the pressure of the hydraulic oil acting on the second circulation oil path 57i when the right travel motor 36R rotates as a third travel pressure V3. 80c, and a fourth pressure that is provided on the fourth port P14 side of the right travel motor 36R and detects the pressure of the hydraulic oil acting on the second circulation oil passage 57i when the right travel motor 36R rotates as the fourth travel pressure V4. A detection device 80d is provided, and the control device 60 determines that when the aircraft 2 is traveling straight and moving forward, both the first traveling pressure V1 and the third traveling pressure V3 are set to a straight traveling threshold (first straight traveling threshold SF1 S ). When this time is longer than the first determination time, automatic deceleration is performed.

これによれば、機体２が前進したときにおいて、左走行モータ３６Ｌに対応する走行圧（第１走行圧Ｖ１）及び右走行モータ３６Ｒに対応する走行圧（第３走行圧Ｖ３）が直進閾値（第１直進閾値ＳＦ１S）以上であるときの経過した時間が第１判定時間以上であるときに、自動減速を行うことができる。つまり、第１走行圧Ｖ１、第３走行圧Ｖ３が一定時間、直進閾値（第１直進閾値ＳＦ１S）以上になった場合に、自動減速を行うことができる。 According to this, when the aircraft 2 moves forward, the running pressure (first running pressure V1) corresponding to the left running motor 36L and the running pressure (third running pressure V3) corresponding to the right running motor 36R are set to the straight-line threshold ( Automatic deceleration can be performed when the elapsed time when the first straight-ahead threshold SF1 S ) is equal to or greater than the first determination time. In other words, automatic deceleration can be performed when the first running pressure V1 and the third running pressure V3 are equal to or higher than the straight-line threshold value (first straight-line threshold value SF1 S ) for a certain period of time.

制御装置６０は、第１判定時間を、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが大きくなるにしたがって短く設定し、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが小さくなるにしたがって長く設定する。これによれば、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが小さく車速（走行速度）が遅いときは、第１判定時間が長くなるため、車速が遅い状態が長く続いたときだけ、自動減速を行うことができる。一方で、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが大きく車速（走行速度）が速いときは、必要なときに素早く自動減速を行うことができる。 The control device 60 sets the first determination time to be shorter as the first rotation speed LM RPM or the second rotation speed RM RPM increases, and sets the first determination time to be shorter as the first rotation speed LM RPM or the second rotation speed RM RPM becomes smaller. Therefore, set it long. According to this, when the first rotation speed LM RPM or the second rotation speed RM RPM is small and the vehicle speed (traveling speed) is slow, the first determination time becomes long, so only when the vehicle speed remains slow for a long time, Automatic deceleration can be performed. On the other hand, when the first rotation speed LM RPM or the second rotation speed RM RPM is large and the vehicle speed (traveling speed) is high, automatic deceleration can be performed quickly when necessary.

制御装置６０は、機体２が直進であって前進する場合は、第１走行圧Ｖ１から第２走行圧Ｖ２を減算した第１差圧ΔＶ１と、第３走行圧Ｖ３から第４走行圧Ｖ４を減算した第３差圧ΔＶ３との両方が直進閾値（第２直進閾値ＳＦ２S）以上である時間が第２判定時間以上であるとき、自動減速を行う。これによれば、機体２が前進したときにおいて、左走行モータ３６Ｌに対応する有効の走行圧（第１差圧ΔＶ１）及び右走行モータ３６Ｒに対応する有効の走行圧（第３差圧ΔＶ３）が直進閾値（第２直進閾値ＳＦ２S）以上であるときの経過した時間が第２判定時間以上であるときに、自動減速を行うことができる。つまり、有効の走行圧（第１差圧ΔＶ１）、有効の走行圧（第３差圧ΔＶ３）が一定時間、直進閾値（第２直進閾値ＳＦ２S）以上になった場合に、自動減速を行うことができる。 When the aircraft 2 is moving straight ahead, the control device 60 calculates a first differential pressure ΔV1 obtained by subtracting the second running pressure V2 from the first running pressure V1, and a fourth running pressure V4 from the third running pressure V3. When the time during which both the subtracted third differential pressure ΔV3 and the third differential pressure ΔV3 are equal to or greater than the straight-line threshold (second straight-travel threshold SF2 S ) is equal to or longer than the second determination time, automatic deceleration is performed. According to this, when the aircraft body 2 moves forward, the effective running pressure (first differential pressure ΔV1) corresponding to the left running motor 36L and the effective running pressure (third differential pressure ΔV3) corresponding to the right running motor 36R. Automatic deceleration can be performed when the elapsed time when is equal to or greater than the straight-line threshold (second straight-travel threshold SF2 S ) is equal to or longer than the second determination time. In other words, automatic deceleration is performed when the effective running pressure (first differential pressure ΔV1) and effective running pressure (third differential pressure ΔV3) exceed the straight-ahead threshold (second straight-ahead threshold SF2 S ) for a certain period of time. be able to.

制御装置６０は、第２判定時間を、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが大きくなるにしたがって短く設定し、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが小さくなるにしたがって長く設定する。これによれば、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが小さく車速（走行速度）が遅いときは、第１判定時間が長くなるため、車速が遅い状態が長く続いたときだけ、自動減速を行うことができる。一方で、第１回転数ＬＭRPM又は第２回転数ＲＭRPMが大きく車速（走行速度）が速いときは、必要なときに素早く自動減速を行うことができる。 The control device 60 sets the second determination time to be shorter as the first rotation speed LM RPM or the second rotation speed RM RPM increases, and sets the second determination time to be shorter as the first rotation speed LM RPM or the second rotation speed RM RPM becomes smaller. Therefore, set it long. According to this, when the first rotation speed LM RPM or the second rotation speed RM RPM is small and the vehicle speed (traveling speed) is slow, the first determination time becomes long, so only when the vehicle speed remains slow for a long time, Automatic deceleration can be performed. On the other hand, when the first rotation speed LM RPM or the second rotation speed RM RPM is large and the vehicle speed (traveling speed) is high, automatic deceleration can be performed quickly when necessary.

制御装置６０は、走行操作部材５９の操作が機体２を前進させる方向に操作され且つ、左走行モータ３６Ｌ及び右走行モータ３６Ｒが機体２の後進に対応する方向に回転している場合は、自動減速を行わない。これによれば、機体２が後進している状態から走行操作部材５９を、瞬時に前進側に操作した場合は、自動減速を行わないようにすることで、作業機１の後進を安定的させることができる。 When the travel operation member 59 is operated in a direction to move the aircraft 2 forward, and the left travel motor 36L and the right travel motor 36R are rotated in a direction corresponding to the backward movement of the aircraft 2, the control device 60 automatically Do not decelerate. According to this, when the traveling operation member 59 is instantaneously operated to the forward side while the machine body 2 is moving backward, automatic deceleration is not performed, so that the backward movement of the work equipment 1 is stabilized. be able to.

制御装置６０は、左走行モータ３６Ｌの第１回転数ＬＭRPMが所定回転数以上、又は、右走行モータ３６Ｒの第２回転数ＲＭRPMが所定回転以上である場合に、自動減速を行わない。これによれば、第１回転数ＬＭRPM及び第２回転数ＲＭRPMが高い領域にあるときに、自動減速を行わないようにすることで作業性を向上させることができる。
制御装置６０は、左走行モータ３６Ｌの第１回転数ＬＭRPMが当該左走行モータ３６Ｌの動力で回転する第１最大回転数以上、又は、右走行モータ３６Ｒの第２回転数ＲＭRPMが当該左走行モータ３６Ｌの動力で回転する第２最大回転数以上である場合に、自動減速を行わない。例えば、機体２が第２速度の状態で坂道を登っている状況下において、左走行モータ３６Ｌが第１速度状態であるときの第１最大回転数、右走行モータ３６Ｒが第１速度状態であるときの第２最大回転数を超えたとしても、自動減速を行わないにようにすることで、走行性を低下させることなく、機体２を走行させることができる。 The control device 60 does not perform automatic deceleration when the first rotation speed LM RPM of the left travel motor 36L is equal to or higher than a predetermined rotation speed, or when the second rotation speed RM RPM of the right travel motor 36R is equal to or higher than a predetermined rotation speed. According to this, when the first rotation speed LM RPM and the second rotation speed RM RPM are in a high range, automatic deceleration is not performed, thereby improving work efficiency.
The control device 60 is configured such that the first rotation speed LM RPM of the left travel motor 36L is equal to or higher than the first maximum rotation speed rotated by the power of the left travel motor 36L, or the second rotation speed RM RPM of the right travel motor 36R is set to the left travel motor 36L. Automatic deceleration is not performed when the rotation speed is equal to or higher than the second maximum rotation speed of the drive motor 36L. For example, in a situation where the aircraft 2 is climbing a slope at the second speed, the left travel motor 36L is at the first speed and the first maximum rotation speed is at the first speed, and the right travel motor 36R is at the first speed. Even if the second maximum rotational speed is exceeded, automatic deceleration is not performed, so that the aircraft 2 can be driven without deteriorating the running performance.

上述した実施形態では、左走行モータ３６Ｌ及び右走行モータ３６Ｒは、同時に第１速度、第２速度に切り換わり、自動減速も左走行モータ３６Ｌ及び右走行モータ３６Ｒに対して同時に行われる構成であったが、少なくとも左走行モータ３６Ｌ及び右走行モータ３６Ｒのいずれかが第１速度、第２速度に切り換わり、少なくとも左走行モータ３６Ｌ及び右走行モータ３６Ｒのいずれかが第２速度になっている状態で自動減速を行ってもよい。 In the embodiment described above, the left travel motor 36L and the right travel motor 36R are simultaneously switched to the first speed and the second speed, and automatic deceleration is also performed simultaneously for the left travel motor 36L and the right travel motor 36R. However, at least one of the left travel motor 36L and the right travel motor 36R is switched to the first speed and the second speed, and at least one of the left travel motor 36L and the right travel motor 36R is at the second speed. Automatic deceleration may be performed.

また、走行モータ（左走行モータ３６Ｌ、右走行モータ３６Ｒ）は、アキシャルピストンモータであってもラジアルピストンモータであってもよい。走行モータがラジアルピストンモータ、ラジアルピストンモータのいずれであっても、モータ容量が大きくなることで第１速に切り換えることができ、モータ容量が小さくなることで第２速に切り換えることができる。 Further, the travel motors (left travel motor 36L, right travel motor 36R) may be an axial piston motor or a radial piston motor. Regardless of whether the travel motor is a radial piston motor or a radial piston motor, it is possible to switch to the first speed by increasing the motor capacity, and it is possible to switch to the second speed by decreasing the motor capacity.

今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味及び範囲内での全ての変更が含まれることが意図される。 The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

１ ：作業機
２ ：機体
５Ｌ ：左走行装置
５Ｒ ：右走行装置
５３Ｌ ：左走行ポンプ
５３Ｒ ：右走行ポンプ
５４ ：操作装置（走行操作弁）
５７ｈ ：循環油路（第１循環油路）
５７ｉ ：循環油路（第２循環油路）
６０ ：制御装置
６８ａ ：第１回転検出装置
６８ｂ ：第２回転検出装置
８０ａ ：第１圧力検出装置
８０ｂ ：第２圧力検出装置
８０ｃ ：第３圧力検出装置
８０ｄ ：第４圧力検出装置 1: Work equipment 2: Machine body 5L: Left travel device 5R: Right travel device 53L: Left travel pump 53R: Right travel pump 54: Operating device (travel operation valve)
57h: Circulation oil path (first circulation oil path)
57i: Circulation oil path (second circulation oil path)
60: Control device 68a: First rotation detection device 68b: Second rotation detection device 80a: First pressure detection device 80b: Second pressure detection device 80c: Third pressure detection device 80d: Fourth pressure detection device

Claims (5)

機体と、
前記機体の左側に設けられた左走行装置と、
前記機体の右側に設けられた右走行装置と、
前記左走行装置に動力を伝達可能な左走行モータと、
前記右走行装置に動力を伝達可能な右走行モータと、
前記左走行モータの第１回転数を検出する第１回転検出装置と、
前記右走行モータの第２回転数を検出する第２回転検出装置と、
前記左走行モータに作動油を供給する左走行ポンプと、
前記右走行モータに作動油を供給する右走行ポンプと、
少なくとも前記左走行ポンプ及び前記右走行ポンプのいずれかの操作を行う走行操作装置と、
前記左走行モータ及び前記右走行モータが第１速度よりも高速な第２速度である場合に、前記第２速度から前記第１速度に自動的に減速する自動減速を行う制御装置と、
を備え、
前記制御装置は、前記第１回転検出装置が検出した前記第１回転数と前記第２回転検出装置が検出した前記第２回転数との回転差又は回転比率に基づいて、前記自動減速を行う減速閾値として、直進閾値を設定する作業機。 The aircraft and
a left traveling device provided on the left side of the aircraft;
a right traveling device provided on the right side of the aircraft;
a left travel motor capable of transmitting power to the left travel device;
a right travel motor capable of transmitting power to the right travel device;
a first rotation detection device that detects a first rotation speed of the left travel motor;
a second rotation detection device that detects a second rotation speed of the right travel motor;
a left travel pump that supplies hydraulic oil to the left travel motor;
a right travel pump that supplies hydraulic oil to the right travel motor;
a traveling operation device that operates at least one of the left traveling pump and the right traveling pump;
a control device that performs automatic deceleration to automatically decelerate from the second speed to the first speed when the left travel motor and the right travel motor are at a second speed higher than the first speed;
Equipped with
The control device performs the automatic deceleration based on a rotation difference or a rotation ratio between the first rotation speed detected by the first rotation detection device and the second rotation speed detected by the second rotation detection device. A work machine that sets a straight-line threshold as a deceleration threshold. 前記制御装置は、前記回転差が大きくなるにつれて前記直進閾値を高く、前記回転差が小さくなるにつれて前記直進閾値を低く設定する請求項１に記載の作業機。 The working machine according to claim 1, wherein the control device sets the straight-line threshold to be higher as the rotation difference becomes larger, and set the straight-line threshold to be lower as the rotation difference becomes smaller. 前記制御装置は、前記回転比率の差が大きくなるにつれて前記直進閾値を高く、前記回転比率の差が小さくなるにつれて前記直進閾値を低く設定する請求項１に記載の作業機。 The working machine according to claim 1, wherein the control device sets the straight-line threshold value to be higher as the difference in the rotation ratios increases, and sets the straight-line threshold value to be lower as the difference in the rotation ratios becomes smaller. 前記左走行ポンプと前記左走行モータとを接続する第１循環油路と、
前記右走行ポンプと前記右走行モータとを接続する第２循環油路と、
前記左走行モータの第１ポート側に設けられ且つ前記左走行モータの回転時の前記第１循環油路に作用する作動油の圧力を第１走行圧として検出する第１圧力検出装置と、
前記左走行モータの第２ポート側に設けられ且つ前記左走行モータの回転時の前記第１
循環油路に作用する作動油の圧力を第２走行圧として検出する第２圧力検出装置と、
前記右走行モータの第３ポート側に設けられ且つ前記右走行モータの回転時の前記第２循環油路に作用する作動油の圧力を第３走行圧として検出する第３圧力検出装置と、
前記右走行モータの第４ポート側に設けられ且つ前記右走行モータの回転時の前記第２循環油路に作用する作動油の圧力を第４走行圧として検出する第４圧力検出装置と、
を備え、
前記制御装置は、前記機体が直進であって前進する場合は、前記第１走行圧及び前記第３走行圧のいずれかが前記直進閾値以上であるときに、前記自動減速を行う請求項１～３のいずれかに記載の作業機。 a first circulation oil passage connecting the left running pump and the left running motor;
a second circulation oil path connecting the right running pump and the right running motor;
a first pressure detection device that is provided on a first port side of the left travel motor and detects, as a first travel pressure, the pressure of hydraulic oil that acts on the first circulation oil path when the left travel motor rotates;
The first port is provided on the second port side of the left travel motor and when the left travel motor is rotated.
a second pressure detection device that detects the pressure of hydraulic oil acting on the circulation oil path as a second running pressure;
a third pressure detection device that is provided on the third port side of the right travel motor and detects the pressure of hydraulic oil acting on the second circulation oil path when the right travel motor rotates as a third travel pressure;
a fourth pressure detection device that is provided on the fourth port side of the right travel motor and detects the pressure of hydraulic oil acting on the second circulation oil path when the right travel motor rotates as a fourth travel pressure;
Equipped with
The control device performs the automatic deceleration when either the first running pressure or the third running pressure is equal to or higher than the straight-line threshold when the aircraft is moving straight ahead. 3. The working machine according to any one of 3. 前記左走行ポンプと前記左走行モータとを接続する第１循環油路と、
前記右走行ポンプと前記右走行モータとを接続する第２循環油路と、
前記左走行モータの第１ポート側に設けられ且つ前記左走行モータの回転時の前記第１循環油路に作用する作動油の圧力を第１走行圧として検出する第１圧力検出装置と、
前記左走行モータの第２ポート側に設けられ且つ前記左走行モータの回転時の前記第１循環油路に作用する作動油の圧力を第２走行圧として検出する第２圧力検出装置と、
前記右走行モータの第３ポート側に設けられ且つ前記右走行モータの回転時の前記第２循環油路に作用する作動油の圧力を第３走行圧として検出する第３圧力検出装置と、
前記右走行モータの第４ポート側に設けられ且つ前記右走行モータの回転時の前記第２循環油路に作用する作動油の圧力を第４走行圧として検出する第４圧力検出装置と、
を備え、
前記制御装置は、前記機体が直進であって前進する場合は、前記第１走行圧から前記第２走行圧を減算した第１差圧及び前記第３走行圧から前記第４走行圧を減算した第３差圧のいずれかが前記直進閾値以上であるときに、前記自動減速を行う請求項１～３のいずれかに記載の作業機。 a first circulation oil passage connecting the left running pump and the left running motor;
a second circulation oil path connecting the right running pump and the right running motor;
a first pressure detection device that is provided on a first port side of the left travel motor and detects, as a first travel pressure, the pressure of hydraulic oil that acts on the first circulation oil path when the left travel motor rotates;
a second pressure detection device that is provided on the second port side of the left travel motor and detects, as a second travel pressure, the pressure of hydraulic oil that acts on the first circulation oil path when the left travel motor rotates;
a third pressure detection device that is provided on the third port side of the right travel motor and detects the pressure of hydraulic oil acting on the second circulation oil path when the right travel motor rotates as a third travel pressure;
a fourth pressure detection device that is provided on the fourth port side of the right travel motor and detects the pressure of hydraulic oil acting on the second circulation oil path when the right travel motor rotates as a fourth travel pressure;
Equipped with
When the aircraft is moving straight ahead, the control device subtracts the first differential pressure by subtracting the second running pressure from the first running pressure and the fourth running pressure from the third running pressure. The working machine according to any one of claims 1 to 3, wherein the automatic deceleration is performed when any one of the third pressure differences is equal to or greater than the straight-ahead threshold.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060156716A1 (en) 2004-12-31 2006-07-20 Doosan Infracore Co., Ltd. Travel control device for excavators
JP2008082130A (en) 2006-09-29 2008-04-10 Kubota Corp Hydraulic system of backhoe
JP2008248981A (en) 2007-03-29 2008-10-16 Kubota Corp Traveling system of work machine
JP2015064024A (en) 2013-09-24 2015-04-09 株式会社神戸製鋼所 Hydraulic travel unit of working machine
JP2017180695A (en) 2016-03-30 2017-10-05 株式会社クボタ Hydraulic system of working machine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060156716A1 (en) 2004-12-31 2006-07-20 Doosan Infracore Co., Ltd. Travel control device for excavators
JP2008082130A (en) 2006-09-29 2008-04-10 Kubota Corp Hydraulic system of backhoe
JP2008248981A (en) 2007-03-29 2008-10-16 Kubota Corp Traveling system of work machine
JP2015064024A (en) 2013-09-24 2015-04-09 株式会社神戸製鋼所 Hydraulic travel unit of working machine
JP2017180695A (en) 2016-03-30 2017-10-05 株式会社クボタ Hydraulic system of working machine

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