WO2021070736A1 - Construction machine - Google Patents

Construction machine Download PDF

Info

Publication number
WO2021070736A1
WO2021070736A1 PCT/JP2020/037478 JP2020037478W WO2021070736A1 WO 2021070736 A1 WO2021070736 A1 WO 2021070736A1 JP 2020037478 W JP2020037478 W JP 2020037478W WO 2021070736 A1 WO2021070736 A1 WO 2021070736A1
Authority
WO
WIPO (PCT)
Prior art keywords
hydraulic pump
hydraulic
tilt
pump
flow rate
Prior art date
Application number
PCT/JP2020/037478
Other languages
French (fr)
Japanese (ja)
Inventor
宇田川　勉
櫻井　茂行
山本　純司
幸仁 鈴木
Original Assignee
日立建機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立建機株式会社 filed Critical 日立建機株式会社
Publication of WO2021070736A1 publication Critical patent/WO2021070736A1/en

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/26—Indicating devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B51/00—Testing machines, pumps, or pumping installations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems

Definitions

  • the present invention relates to a construction machine such as a hydraulic excavator or a crane equipped with a one-sided tilt type variable displacement hydraulic pump.
  • Patent Document 1 is known as a method for diagnosing a failure of a conventional pump.
  • the pump tilt amount is increased with the hydraulic circuit of the hydraulic pump closed, and the pump tilt amount when the discharge pressure of the hydraulic pump reaches the set pressure is compared with the failure determination value.
  • the amount of tilt of the pump is equal to or greater than the failure judgment value, a failure signal is output, so there is no need to bother to disconnect the hydraulic piping and install a hydraulic tester, and failure diagnosis can be performed automatically and quickly at all times. ..
  • the discharge flow rate of the pump is increased with the hydraulic circuit closed, and the pump tilt amount when the discharge pressure of the hydraulic pump reaches the set pressure is compared with the failure determination value.
  • the pump discharge flow rate is equal to or higher than the failure judgment value, a failure signal is output, so it is considered that it is not necessary to rearrange the hydraulic circuit etc. and it can be dealt with automatically and quickly, but like a construction machine. There are cases where it cannot be applied to devices that use multiple pumps.
  • the pump discharge amount can be set to zero, but in a construction machine such as a hydraulic excavator, in order to drive a single rod cylinder, one piece has an open circuit configuration. In most cases, a tilting pump is used.
  • ⁇ Since the direction switching valve is located between the pump and the actuator, it is not necessary to reduce the tilt amount to zero. ⁇ A certain amount of pump flow rate is required even when the actuator is not operating to ensure responsiveness when the actuator is started. ⁇ Since a certain amount of pump flow rate is required for lubrication and cooling of circuit equipment installed downstream of the pump, a certain amount of flow rate (hereinafter referred to as standby flow rate) is maintained even when the lever is neutral, such as when the actuator is not operating. It is usually configured to discharge from a tilting pump. The minimum tilt amount of the one-side tilt pump is determined according to this standby flow rate.
  • the standby flow rate is set to about 1/5 of the maximum discharge flow rate, and the maximum discharge flow rate is 200 L / min, the standby flow rate is also about 40 L / min.
  • the one-sided tilting pump is not configured to discharge a minute flow rate, even if the diagnostic method of Patent Document 1 is applied to a system using the one-sided tilting pump, a minute leakage flow rate is applied. Cannot be detected or evaluated.
  • the present invention comprises a prime mover, a tank for storing hydraulic oil, and a unilateral tilting variable displacement hydraulic pump driven by the prime mover and discharging hydraulic oil sucked from the tank.
  • a direction switching that is connected to a plurality of hydraulic actuators and a discharge oil passage to which the discharge oil of the hydraulic pump is supplied and controls the flow of hydraulic oil supplied from the hydraulic pump to at least a part of the plurality of hydraulic actuators.
  • the controller includes a pressure sensor for detecting the discharge pressure of the hydraulic pump, and the controller is the discharge oil passage.
  • the rotation speed of the prime mover is changed so that the load can be operated.
  • the discharge pressure of the hydraulic pump is measured, and the leakage flow rate of the hydraulic pump is calculated based on the rotation speed of the prime mover and the tilt for diagnosis when the discharge pressure of the hydraulic pump reaches a predetermined pressure.
  • the communication between the discharge oil passage of the hydraulic pump and the tank is cut off, and the tilt of the hydraulic pump is held at the diagnostic tilt smaller than the standby tilt.
  • It is a functional block diagram of the controller shown in FIG. It is a figure which shows the measurement flow of the pump leakage flow rate executed by the controller shown in FIG.
  • It is a circuit diagram of the hydraulic drive device in the 2nd Example of this invention.
  • FIG. 1 is a side view of the hydraulic excavator according to the first embodiment of the present invention.
  • the hydraulic excavator 100 includes a traveling body 101, a swivel body 102 rotatably mounted on the traveling body 101, and a working device 103 rotatably mounted on the front side of the swivel body 102 in the vertical direction. And have.
  • the working device 103 includes a boom 104 rotatably attached to the front side of the swivel body 102 in the vertical direction, an arm 105 rotatably attached to the tip of the boom 104 in the vertical or vertical direction, and the arm.
  • a bucket 106 that is rotatably attached to the tip of the 105 in the vertical or front-rear direction is provided.
  • the boom 104 is driven by the boom cylinder 107, which is a hydraulic actuator
  • the arm 105 is driven by the arm cylinder 108, which is a hydraulic actuator
  • the bucket 106 is driven by the bucket cylinder 109, which is a hydraulic actuator.
  • a driver's cab 110 on which the operator is boarded is provided on the front side of the swivel body 102.
  • the hydraulic drive system 200 includes an engine 20 as a prime mover, a one-sided tilt type variable displacement hydraulic pump 21 driven by the engine 20, and a pump push-out volume of the hydraulic pump 21 (hereinafter, pump tilt).
  • a hydraulic pilot type tilt control device 22 that controls qp, and an electromagnetic proportional valve 23 that outputs the pilot pressure generated by reducing the primary pressure from the pilot hydraulic source (not shown) to the tilt control device 22.
  • the direction switching valve unit 24 is connected to a discharge oil passage (hereinafter, pump discharge oil passage) 28 connected to the discharge port of the hydraulic pump 21, and is connected to the hydraulic pump 21 in response to an operation of an operating device (not shown). It controls the flow of pressure oil supplied to the hydraulic actuators 107 to 109.
  • pump discharge oil passage hereinafter, pump discharge oil passage
  • the bleed-off closing valve 25 is provided on the upstream side of the direction switching valve unit 24 of the pump discharge oil passage 28, opens and closes in response to a control signal from the controller 40, and communicates or shuts off the pump discharge oil passage 28.
  • Pp pressure in the pump discharge oil passage 28
  • Pr pressure in the pump discharge oil passage 28
  • the pressure sensor 27 is provided on the upstream side of the bleed-off closing valve 25 of the pump discharge oil passage 28, converts the pressure of the pump discharge oil passage 28 (pump discharge pressure Pp) into a pressure signal, and outputs it to the controller 40.
  • the controller 40 receives a command for measuring the pump leakage flow rate, controls the bleed-off closing valve 25, the engine rotation speed (hereinafter referred to as engine rotation speed) Neng, and the pump tilt qp, and discharges the pump detected by the pressure sensor 27.
  • the leakage flow rate Qleak of the hydraulic pump 21 is calculated based on the pressure Pp.
  • Axial piston type pumps are often used as hydraulic pumps for construction machinery, and there are diagonal shaft type and swash plate type as variable capacitance mechanism. In both cases, the variable capacitance is realized by changing the stroke process of the piston to change the push-out volume.
  • variable displacement oblique shaft hydraulic pump 21 As an example of the unilateral tilt type variable displacement hydraulic pump 21, the structure of the variable displacement oblique shaft hydraulic pump is shown in FIG.
  • the tubular casing 1 is composed of a substantially cylindrical casing main body 1A having a bearing portion on one end side and a head casing 1B in which the other end side of the casing main body 1A is closed.
  • the rotating shaft 2 is rotatably provided in the casing body 1A.
  • the cylinder block 3 is located in the casing body 1A and rotates together with the rotating shaft 2.
  • a plurality of cylinders 4 are bored in the cylinder block 3 in the axial direction thereof.
  • a piston 5 is slidably provided in each cylinder 4, and a connecting rod 6 is attached to each piston 5.
  • a spherical portion 6A is formed at the tip of each connecting rod 6, and each spherical portion 6A is swingably supported by a drive disk 7 formed at the tip of the rotating shaft 2.
  • the cylinder block 3 is arranged together with the valve plate 8 described later with a tilt angle ⁇ as a tilt amount with respect to the rotation shaft 2, and the pump push-off capacity is determined by this tilt angle ⁇ .
  • the cylinder block 3 is in sliding contact with the one side end surface of the valve plate 8, and the other side end surface of the valve plate 8 is in sliding contact with the concavely curved tilting sliding surface 9 formed in the head casing 1B.
  • a through hole 8A is bored in the center of the valve plate 8, and the tip portions of the center shaft 10 and the swing pin 15, which will be described later, are inserted into the through hole 8A from both sides.
  • a pair of supply / discharge ports (not shown) that intermittently communicate with each cylinder 4 when the cylinder block 3 rotates are bored in the valve plate 8 and opens to the tilting sliding surface 9 of the head casing 1B.
  • a pair of supply / discharge passages (not shown) communicate with these supply / discharge ports regardless of the tilt position (tilt angle ⁇ ) of the valve plate 8.
  • the center shaft 10 supports the cylinder block 3 between the drive disk 7 and the valve plate 8.
  • a spherical portion 10A is formed on one end side of the center shaft 10, and the spherical portion 10A is swingably supported at the axial center position of the drive disk 7.
  • the other end side of the center shaft 10 protruding through the center of the cylinder block 3 is slidably inserted into the through hole 8A of the valve plate 8 so that the cylinder block 3 is centered with respect to the valve plate 8. It has become.
  • the tilting mechanism 11 tilts the valve plate 8 along the tilting sliding surface 9.
  • the tilting mechanism 11 is slidably inserted into the cylinder chamber 12 which is formed in the head casing 1B and has oil passage holes 12A and 12B on both ends in the axial direction, and is slidably inserted in the cylinder chamber 12.
  • the servo piston 14 defining the hydraulic chambers 13A and 13B and the base end side are fixed to the servo piston 14, and the tip side becomes a spherical tip portion 15A and is swingably inserted into the through hole 8A of the valve plate 8. It is composed of a swing pin 15 and a cylinder.
  • the control unit 16 tilts and controls the valve plate 8 via the tilting mechanism 11.
  • the control unit 16 is provided on the outside of the head casing 1B, and includes a throttle switching valve (neither shown) that feedback-controls the amount of pressure oil supplied / discharged from the pilot pump (pilot pressure).
  • a sleeve (not shown) is provided on the throttle switching valve, and the sleeve and the servo piston 14 are integrally connected by a feedback pin 17 inserted into a long hole 1C of the head casing 1B.
  • the pressure oil (piston pressure) corresponding to the switching operation amount at this time is tilted from the pilot pump via the oil passage holes 12A and 12B.
  • the servo piston 14 is supplied and discharged into the hydraulic chambers 13A and 13B of the rolling mechanism 11, and the servo piston 14 is slidably displaced by the pressure difference between the hydraulic chambers 13A and 13B, so that the servo piston 14 is valved via the swing pin 15.
  • the plate 8 and the cylinder block 3 are tilted in the direction of arrow A with a tilt angle ⁇ .
  • the sleeve of the throttle switching valve is displaced according to the displacement of the servo piston 14, so that the pressure oil amount from the pilot pump is feedback-controlled, and the displacement amount of the servo piston 14 is the switching operation amount of the throttle switching valve. Hold in the state corresponding to.
  • the swash plate or the swash plate tilt amount (hereinafter referred to as tilt) can be changed in the swash plate pump to change the tilt amount per rotation.
  • the discharge flow rate of the pump can be made variable by changing the amount of push-out of the piston. Therefore, it is possible to control the pump discharge amount by controlling the tilt amount of the swash plate or the swash plate, and the posture of the pump mechanism is controlled.
  • the double tilt type pump it is necessary for the double tilt type pump to swing the tilt angle in both directions, which may increase the functional aspect, and the structure is significantly different and the number of parts increases, which is cost effective. Will also be expensive.
  • the double tilt type pump has poor suction performance and is not preferable in terms of use, and a charge circuit is required for circulation and lubrication of oil to the auxiliary device. Therefore, it is not practical to use a double tilt pump in one tilt, and it is natural to use a single tilt pump type if the machine meets the specifications with a single tilt pump such as a shovel. It has become.
  • Qpref Theoretical pump discharge flow rate
  • Qleak Pump leak flow rate
  • Qrelief Relief flow rate
  • Qcb Center bypass flow rate (bleed-off flow rate)
  • B Volume modulus
  • V Pump discharge volume
  • the pump discharge pressure Pp when the pump discharge pressure Pp is lower than the relief set pressure Pr, the relief flow rate Qrelief becomes zero. Further, when the bleed-off closing valve 25 is closed, the center bypass flow rate Qcb becomes zero. Further, when the pump discharge pressure Pp is stable, the rate of change dPp / dt of the pump discharge pressure Pp becomes sufficiently small. In such a circuit state, the theoretical pump discharge flow rate Qpref is equal to the pump leak flow rate Qleak. Therefore, the pump leakage flow rate Qleak can be measured by calculating the theoretical pump discharge flow rate Qpref in such a circuit state.
  • Patent Document 1 targets a double tilting pump, the pump discharge flow rate can be freely changed from zero.
  • the standby flow rate of the single tilting pump described above is 50 L / min
  • This is equivalent to 5 times the pump tilt (5 cm 3 / rev) for measuring the leak flow rate of 5%.
  • the standby tilt is the minimum tilt
  • the discharge flow rate of the one-side tilt type pump cannot be reduced to the equivalent of a leakage flow rate of 5%.
  • the minimum tilt of the pump is configured to be switched between normal operation and leak diagnosis as follows.
  • the diagnostic tilt qpd satisfies the following conditions with respect to the minimum engine speed Neng_min (usually idling speed) and the measurable minimum leakage flow rate Qleak_min that can be operated under hydraulic load of construction machinery. There is a need.
  • the pump discharge flow rate can be suppressed to the minimum leakage flow rate Qleak_min or less by lowering the engine speed Neng to the minimum rotation speed Neng_min, so the minimum leakage flow rate Qleak_min is measured. It becomes possible to do.
  • FIG. 4 shows the functional block of the controller 40. In FIG. 4, only the configuration related to the measurement of the leakage flow rate of the hydraulic pump 21 is shown, and the configuration related to the driving of the actuators 107 to 109 is omitted.
  • the hydraulic pump 21 is in a state where the communication between the discharge oil passage 28 of the hydraulic pump 21 and the tank 29 is cut off (a state in which the bleed-off flow rate and the relief flow rate are zero).
  • the tilt qp was held in the diagnostic tilt qpd smaller than the standby tilt qps, the flow rate Neng of the prime mover 20 was raised from the minimum flow rate Neng_min, and the discharge pressure Pp of the hydraulic pump 21 reached a predetermined pressure Ps.
  • the leakage flow rate Qleak of the hydraulic pump 21 can be measured in a minute flow rate range smaller than the standby flow rate. As a result, the predictive diagnosis of the hydraulic pump 21 becomes possible.
  • the bleed-off closing valve 25 (shown in FIG. 2) provided on the upstream side of the directional control valve unit 24, the bleed-off closing valve provided on the downstream side of the directional switching valve units 24a and 24b It differs from the first embodiment in that it includes 25a and 25b.
  • directional switching valves 24a1, 24b1 for controlling the flow of pressure oil supplied to the actuator are provided in parallel with the supply ports of each pump, and from these directional switching valves 24a1, 24b1.
  • the leakage of pressure oil affects the drive of the actuator in the same way as the leakage of the pump.
  • the total flow rate of the pump leakage flow rate Qleak and the direction switching valve leakage flow rate Qcv is calculated as the theoretical pump discharge flow rate Qpref, and the entire pressure oil supply system including the hydraulic pumps 21a and 21b and the direction switching valve units 24a and 24b It is possible to measure the leakage flow rate of.
  • the leakage flow rate of the entire pressure oil supply system can be measured from a minute flow rate region, the bleed-off flow rate is zero, and the relief flow rate is reduced.
  • the leakage flow rate of the pressure oil supply system is accurately measured through the theoretical pump discharge flow rate Qleak when the pump discharge pressure gradually exceeds the threshold (30 MPa) under the condition of zero, and the pressure oil supply of construction machinery is supplied. It becomes possible to evaluate the degree of damage as a source.
  • the hydraulic excavator 100 in this embodiment is provided on bypass lines 60a and 60b connecting the direction switching valve units 24a and 24b and the tank 29, and is a bleed-off closing valve 25a and 25b that opens and closes in response to a control signal from the controller 40.
  • the controller 40 shuts off the communication between the discharge oil passages 28a and 28b and the tank 29 by closing the bleed-off closing valves 25a and 25b.
  • the purpose of this embodiment is to provide a method for evaluating and diagnosing the amount of leakage when the evaluation and comparison of measurement results are inappropriate when the measurement environment is significantly different from the normal measurement environment.
  • the oil temperature may be very low, such as ⁇ 20 ° C.
  • the flow rate leaking from the annular gap of the pump is generally affected by the viscosity of the oil, etc., so it is assumed that the temperature environment affects the degree of leakage.
  • the temperature differs greatly depending on whether the hydraulic oil is warmed up or not, it is not appropriate to quantitatively evaluate the leak flow rate calculated for each pump.
  • a method of calculating a leak flow rate suitable for evaluation will be described when the measurement environment is significantly different.
  • left and right traveling motors 120L and 120R exist, so that two hydraulic pumps having the same specifications are provided in order to obtain left-right equivalence. Is customary. If these two hydraulic pumps are not damaged and have similar leakage flow rate characteristics, the leakage flow rates of the two hydraulic pumps 21a and 21b will be high even if the environment such as temperature is significantly different from usual. Should be equivalent. Conversely, when the leakage flow rates of the two hydraulic pumps 21a and 2b are significantly different, it can be considered that the hydraulic pump having the larger leakage flow rate is more damaged than the other hydraulic pump.
  • the hydraulic excavator 100 in this embodiment is driven by a prime mover 20 and is supplied with a uni-tilt variable displacement type second hydraulic pump 21b for discharging hydraulic oil sucked from a tank 29 and discharge oil for the second hydraulic pump 21b.
  • a second direction switching valve unit 24b which is connected to the second discharge oil passage 28b and controls the flow of hydraulic oil supplied from the second hydraulic pump 21b to the plurality of hydraulic actuators 107 to 109, and a second hydraulic pump 21b.
  • a second pressure sensor 27b for detecting the discharge pressure of the hydraulic oil and a temperature sensor 30 for detecting the temperature of the hydraulic oil are further provided, and the controller 40 cuts off the communication between the second discharge oil passage 29b and the tank 29.
  • the discharge pressure of the second hydraulic pump 21b is measured while increasing the rotation speed Neng of the prime mover 20 from the minimum rotation speed Neng_min, and the second The leakage flow rate Qleak2 of the second hydraulic pump 21b is calculated based on the rotation speed Neng of the prime mover 20 when the discharge pressure of the hydraulic pump 21b reaches a predetermined pressure Ps and the tilt qp0 for diagnosis, and the temperature of the hydraulic oil is adjusted to Qleak2.
  • the calculated values of the leakage flow rates Qleak1 and Qleak2 of the first hydraulic pump 21a and the second hydraulic pump 21b are corrected.
  • the rotation speed Neng of the prime mover 20 when measuring the discharge pressure of the second hydraulic pump 21b, the rotation speed Neng of the prime mover 20 is controlled to be increased from the minimum rotation speed Neng_min, but the rotation speed of the prime mover 20 is controlled.
  • the method is not limited to this, and for example, control may be performed to reduce the maximum rotation speed from Neng_max.
  • Engine (motor), 21 ... Hydraulic pump (first hydraulic pump), 21a ... Hydraulic pump (first hydraulic pump), 21b ... Hydraulic pump (second hydraulic pump), 22, 22a, 22b ... Tilt control device, 23 ... Electromagnetic proportional valve, 24 ... Direction switching valve unit (first direction switching valve unit) ), 24a ... Direction switching valve unit (first direction switching valve unit), 24b ... Direction switching valve unit (second direction switching valve unit), 25, 25a, 25b ... Bleed-off closing valve, 26 ... Relief valve, 27 ... Pressure sensor (first pressure sensor), 27a ... pressure sensor (first pressure sensor), 27b ... pressure sensor (second pressure sensor), 28 ... pump discharge oil passage (first discharge oil passage), 28a ...

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

Provided is a construction machine that can measure a minute leakage flow rate of a unilateral tilt-type variable displacement hydraulic pump.　In a state in which communication between a discharge oil passage of the hydraulic pump and a tank is cut off and the tilt of the hydraulic pump is held at a diagnostic tilt set smaller than a standby tilt, a controller measures the discharge pressure of the hydraulic pump while changing the rotation speed of a prime mover, and calculates the leakage flow rate of the hydraulic pump on the basis of the rotation speed of the prime mover and the diagnostic tilt when the discharge pressure of the hydraulic pump reaches a predetermined pressure.

Description

建設機械Construction machinery
　本発明は、片傾転型可変容量式油圧ポンプを搭載した油圧ショベルやクレーン等の建設機械に関する。 The present invention relates to a construction machine such as a hydraulic excavator or a crane equipped with a one-sided tilt type variable displacement hydraulic pump.
　従来ポンプの故障を診断する方法として例えば特許文献１が知られている。 For example, Patent Document 1 is known as a method for diagnosing a failure of a conventional pump.
　特許文献１では、油圧ポンプの油圧回路を閉じた状態でポンプ傾転量を増加していき、油圧ポンプの吐出圧が設定圧に達したときのポンプ傾転量を故障判定値と比較し、ポンプ傾転量が故障判定値以上である場合、故障信号を出力するようにしたので、わざわざ油圧配管を切離して油圧テスタを取り付ける必要はなく、常時自動的かつ迅速に故障診断を行うことができる。 In Patent Document 1, the pump tilt amount is increased with the hydraulic circuit of the hydraulic pump closed, and the pump tilt amount when the discharge pressure of the hydraulic pump reaches the set pressure is compared with the failure determination value. When the amount of tilt of the pump is equal to or greater than the failure judgment value, a failure signal is output, so there is no need to bother to disconnect the hydraulic piping and install a hydraulic tester, and failure diagnosis can be performed automatically and quickly at all times. ..
特公平６－９４８６８号公報Special Fair 6-94868 Gazette
　特許文献１の診断方法においては、油圧回路を閉じた状態でポンプの吐出流量を増加していき、油圧ポンプの吐出圧が設定圧に達したときのポンプ傾転量を故障判定値と比較し、ポンプ吐出流量が故障判定値以上の場合、故障信号を出力するようにしたので、油圧回路等の組替え等が不要で自動的かつ迅速に対応できるように考慮されているが、建設機械のようなポンプを複数利用する装置においては適用することができない場合が存在する。 In the diagnostic method of Patent Document 1, the discharge flow rate of the pump is increased with the hydraulic circuit closed, and the pump tilt amount when the discharge pressure of the hydraulic pump reaches the set pressure is compared with the failure determination value. , When the pump discharge flow rate is equal to or higher than the failure judgment value, a failure signal is output, so it is considered that it is not necessary to rearrange the hydraulic circuit etc. and it can be dealt with automatically and quickly, but like a construction machine. There are cases where it cannot be applied to devices that use multiple pumps.
　また、特許文献１では両傾転型ポンプを対象としているのでポンプ吐出量をゼロにすることができるが、油圧ショベルのような建設機械では片ロッドシリンダを駆動するために、オープン回路構成で片傾転型ポンプを採用していることがほとんどである。 Further, in Patent Document 1, since the target is a bi-tilt type pump, the pump discharge amount can be set to zero, but in a construction machine such as a hydraulic excavator, in order to drive a single rod cylinder, one piece has an open circuit configuration. In most cases, a tilting pump is used.
　片傾転型ポンプを用いたシステムでは、
　・ポンプとアクチュエータの間に方向切換弁が介在するため傾転量をゼロにする必要はないこと
　・アクチュエータ始動時の応答性確保のために、アクチュエータ非動作時もある程度のポンプ流量が必要なこと
　・ポンプの下流に設けられた回路機器の潤滑やクーリングのためにある程度のポンプ流量が必要なこと
　等からアクチュエータ非動作時などのレバー中立のときにおいてもある程度の流量（以下、スタンバイ流量）を片傾転ポンプから吐出するように構成しているのが通常である。このスタンバイ流量に応じて片傾転ポンプの最小傾転量が決定される。 In a system using a unidirectional pump,
・ Since the direction switching valve is located between the pump and the actuator, it is not necessary to reduce the tilt amount to zero. ・ A certain amount of pump flow rate is required even when the actuator is not operating to ensure responsiveness when the actuator is started.・ Since a certain amount of pump flow rate is required for lubrication and cooling of circuit equipment installed downstream of the pump, a certain amount of flow rate (hereinafter referred to as standby flow rate) is maintained even when the lever is neutral, such as when the actuator is not operating. It is usually configured to discharge from a tilting pump. The minimum tilt amount of the one-side tilt pump is determined according to this standby flow rate.
　ここで、スタンバイ流量が最大吐出流量の１／５程度に設定されていた場合、最大吐出流量が２００Ｌ／ｍｉｎとすると、スタンバイ流量は４０Ｌ／ｍｉｎ程度にもなる。このように、片傾転型ポンプは微小流量を吐出するようには構成されていないため、片傾転型ポンプを用いたシステムに特許文献１の診断方法を適用しても、微小な漏れ流量の検知や評価を行うことができない。 Here, when the standby flow rate is set to about 1/5 of the maximum discharge flow rate, and the maximum discharge flow rate is 200 L / min, the standby flow rate is also about 40 L / min. As described above, since the one-sided tilting pump is not configured to discharge a minute flow rate, even if the diagnostic method of Patent Document 1 is applied to a system using the one-sided tilting pump, a minute leakage flow rate is applied. Cannot be detected or evaluated.
　本発明は、上記の課題に鑑みてなされたものであり、その目的は、片傾転型可変容量式油圧ポンプの微小な漏れ流量を測定することが可能な建設機械を提供することにある。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a construction machine capable of measuring a minute leakage flow rate of a unilateral tilting variable displacement hydraulic pump.
　上記目的を達成するために、本発明は、原動機と、作動油を貯留するタンクと、前記原動機によって駆動され、前記タンクから吸い込んだ作動油を吐出する片傾転型可変容量式の油圧ポンプと、複数の油圧アクチュエータと、前記油圧ポンプの吐出油が供給される吐出油路に接続され、前記油圧ポンプから前記複数の油圧アクチュエータの少なくとも一部に供給される作動油の流れを制御する方向切換弁ユニットと、前記原動機の回転数および前記油圧ポンプの傾転を制御するコントローラとを備えた建設機械において、前記油圧ポンプの吐出圧力を検出する圧力センサを備え、前記コントローラは、前記吐出油路と前記タンクとの連通を遮断し、かつ前記油圧ポンプの傾転をスタンバイ傾転よりも小さく設定された診断用傾転に保持した状態で、前記原動機の回転数を負荷運転可能な変化させつつ前記油圧ポンプの吐出圧力を計測し、前記油圧ポンプの吐出圧力が所定の圧力に達したときの前記原動機の回転数と前記診断用傾転とに基づいて前記油圧ポンプの漏れ流量を算出するものとする。 In order to achieve the above object, the present invention comprises a prime mover, a tank for storing hydraulic oil, and a unilateral tilting variable displacement hydraulic pump driven by the prime mover and discharging hydraulic oil sucked from the tank. , A direction switching that is connected to a plurality of hydraulic actuators and a discharge oil passage to which the discharge oil of the hydraulic pump is supplied and controls the flow of hydraulic oil supplied from the hydraulic pump to at least a part of the plurality of hydraulic actuators. In a construction machine including a valve unit and a controller for controlling the rotation speed of the prime mover and the tilt of the hydraulic pump, the controller includes a pressure sensor for detecting the discharge pressure of the hydraulic pump, and the controller is the discharge oil passage. While the communication between the hydraulic pump and the tank is cut off and the tilt of the hydraulic pump is held at the diagnostic tilt set smaller than the standby tilt, the rotation speed of the prime mover is changed so that the load can be operated. The discharge pressure of the hydraulic pump is measured, and the leakage flow rate of the hydraulic pump is calculated based on the rotation speed of the prime mover and the tilt for diagnosis when the discharge pressure of the hydraulic pump reaches a predetermined pressure. And.
　以上のように構成した本発明によれば、油圧ポンプの吐出油路とタンクとの連通を遮断し、かつ油圧ポンプの傾転をスタンバイ傾転よりも小さい診断用傾転に保持した状態で、原動機の回転数を変化させ、油圧ポンプの吐出圧力が所定の圧力に達したときの理論吐出流量を算出することにより、スタンバイ流量よりも小さい微小流量の範囲で油圧ポンプの漏れ流量を測定することが可能となる。 According to the present invention configured as described above, the communication between the discharge oil passage of the hydraulic pump and the tank is cut off, and the tilt of the hydraulic pump is held at the diagnostic tilt smaller than the standby tilt. To measure the leakage flow rate of the hydraulic pump in a minute flow rate smaller than the standby flow rate by changing the rotation speed of the prime mover and calculating the theoretical discharge flow rate when the discharge pressure of the hydraulic pump reaches a predetermined pressure. Is possible.
　本発明に係る建設機械によれば、片傾転型可変容量式油圧ポンプの微小な漏れ流量を測定することが可能となる。 According to the construction machine according to the present invention, it is possible to measure a minute leakage flow rate of a unilateral tilting type variable displacement hydraulic pump.
本発明の第１の実施例に係る油圧ショベルの側面図である。It is a side view of the hydraulic excavator which concerns on 1st Example of this invention. 図１に示す油圧ショベルに搭載された油圧駆動装置の概略構成図である。It is a schematic block diagram of the hydraulic drive device mounted on the hydraulic excavator shown in FIG. 可変容量型斜軸式油圧ポンプの構造図である。It is a structural drawing of the variable capacity type oblique shaft type hydraulic pump. 図２に示すコントローラの機能ブロック図である。It is a functional block diagram of the controller shown in FIG. 図２に示すコントローラによって実行されるポンプ漏れ流量の測定フローを示す図である。It is a figure which shows the measurement flow of the pump leakage flow rate executed by the controller shown in FIG. 本発明の第２の実施例における油圧駆動装置の回路図である。It is a circuit diagram of the hydraulic drive device in the 2nd Example of this invention. 本発明の第３の実施例における油圧駆動装置の概略構成図である。It is a schematic block diagram of the hydraulic drive system in 3rd Example of this invention. 本発明の第３の実施例におけるポンプ漏れ流量の補正演算処理を示す図である。It is a figure which shows the correction calculation process of the pump leakage flow rate in the 3rd Example of this invention.
　以下、本発明の実施の形態に係る建設機械として油圧ショベルを例に挙げ、図面を参照して説明する。なお、各図中、同等の部材には同一の符号を付し、重複した説明は適宜省略する。 Hereinafter, a hydraulic excavator will be taken as an example as a construction machine according to an embodiment of the present invention, and will be described with reference to the drawings. In each figure, the same members are designated by the same reference numerals, and duplicate description will be omitted as appropriate.
　図１は、本発明の第１の実施例に係る油圧ショベルの側面図である。 FIG. 1 is a side view of the hydraulic excavator according to the first embodiment of the present invention.
　図１において、油圧ショベル１００は、走行体１０１、この走行体１０１上に旋回可能に取り付けられた旋回体１０２と、この旋回体１０２の前側に上下方向に回動可能に取り付けられた作業装置１０３とを備えている。 In FIG. 1, the hydraulic excavator 100 includes a traveling body 101, a swivel body 102 rotatably mounted on the traveling body 101, and a working device 103 rotatably mounted on the front side of the swivel body 102 in the vertical direction. And have.
　作業装置１０３は、旋回体１０２の前側に上下方向に回動可能に取り付けられたブーム１０４と、このブーム１０４の先端部に上下または前後方向に回動可能に取り付けられたアーム１０５と、このアーム１０５の先端部に上下または前後方向に回動可能に取り付けられたバケット１０６とを備えている。ブーム１０４は、油圧アクチュエータであるブームシリンダ１０７によって駆動され、アーム１０５は油圧アクチュエータであるアームシリンダ１０８によって駆動され、バケット１０６は油圧アクチュエータであるバケットシリンダ１０９によって駆動される。旋回体１０２の前側には、オペレータが搭乗する運転室１１０が設けられている。 The working device 103 includes a boom 104 rotatably attached to the front side of the swivel body 102 in the vertical direction, an arm 105 rotatably attached to the tip of the boom 104 in the vertical or vertical direction, and the arm. A bucket 106 that is rotatably attached to the tip of the 105 in the vertical or front-rear direction is provided. The boom 104 is driven by the boom cylinder 107, which is a hydraulic actuator, the arm 105 is driven by the arm cylinder 108, which is a hydraulic actuator, and the bucket 106 is driven by the bucket cylinder 109, which is a hydraulic actuator. A driver's cab 110 on which the operator is boarded is provided on the front side of the swivel body 102.
　図２に油圧ショベル１００に搭載された油圧駆動装置の概略構成を示す。 FIG. 2 shows a schematic configuration of a hydraulic drive device mounted on the hydraulic excavator 100.
　図２において、油圧駆動装置２００は、原動機としてのエンジン２０と、エンジン２０によって駆動される片傾転型可変容量式の油圧ポンプ２１と、油圧ポンプ２１のポンプ押しのけ容積（以下、ポンプ傾転）ｑｐを制御する油圧パイロット式の傾転制御装置２２と、パイロット油圧源（図示せず）からの一次圧を減圧して生成したパイロット圧を傾転制御装置２２に出力する電磁比例弁２３と、油圧アクチュエータ１０７～１０９と、方向切換弁ユニット２４と、ブリードオフ閉鎖バルブ２５と、リリーフ弁２６と、圧力センサ２７と、モニタ５０と、エンジン２０、電磁比例弁２３、ブリードオフ閉鎖バルブ２５、モニタ５０等を制御するコントローラ４０とを備えている。 In FIG. 2, the hydraulic drive system 200 includes an engine 20 as a prime mover, a one-sided tilt type variable displacement hydraulic pump 21 driven by the engine 20, and a pump push-out volume of the hydraulic pump 21 (hereinafter, pump tilt). A hydraulic pilot type tilt control device 22 that controls qp, and an electromagnetic proportional valve 23 that outputs the pilot pressure generated by reducing the primary pressure from the pilot hydraulic source (not shown) to the tilt control device 22. Hydraulic actuators 107 to 109, direction switching valve unit 24, bleed-off closing valve 25, relief valve 26, pressure sensor 27, monitor 50, engine 20, electromagnetic proportional valve 23, bleed-off closing valve 25, monitor. It includes a controller 40 that controls 50 and the like.
　方向切換弁ユニット２４は、油圧ポンプ２１の吐出ポートに接続された吐出油路（以下、ポンプ吐出油路）２８に接続され、操作装置（図示せず）の操作に応じて、油圧ポンプ２１から油圧アクチュエータ１０７～１０９に供給される圧油の流れを制御する。 The direction switching valve unit 24 is connected to a discharge oil passage (hereinafter, pump discharge oil passage) 28 connected to the discharge port of the hydraulic pump 21, and is connected to the hydraulic pump 21 in response to an operation of an operating device (not shown). It controls the flow of pressure oil supplied to the hydraulic actuators 107 to 109.
　ブリードオフ閉鎖バルブ２５は、ポンプ吐出油路２８の方向切換弁ユニット２４よりも上流側に設けられ、コントローラ４０から制御信号に応じて開閉し、ポンプ吐出油路２８を連通または遮断する。 The bleed-off closing valve 25 is provided on the upstream side of the direction switching valve unit 24 of the pump discharge oil passage 28, opens and closes in response to a control signal from the controller 40, and communicates or shuts off the pump discharge oil passage 28.
　リリーフ弁２６は、ポンプ吐出油路２８の圧力を制限する安全弁であり、ポンプ吐出油路２８のブリードオフ閉鎖バルブ２５よりも上流側に設けられ、ポンプ吐出油路２８の圧力（＝ポンプ吐出圧力Ｐｐ）が所定の圧力（以下、リリーフ設定圧）Ｐｒを超えると開弁し、ポンプ吐出油路２８の圧油をタンク２９に排出する。 The relief valve 26 is a safety valve that limits the pressure in the pump discharge oil passage 28, and is provided on the upstream side of the bleed-off closing valve 25 in the pump discharge oil passage 28, and the pressure in the pump discharge oil passage 28 (= pump discharge pressure). When Pp) exceeds a predetermined pressure (hereinafter, relief set pressure) Pr, the valve is opened and the pressure oil in the pump discharge oil passage 28 is discharged to the tank 29.
　圧力センサ２７は、ポンプ吐出油路２８のブリードオフ閉鎖バルブ２５よりも上流側に設けられ、ポンプ吐出油路２８の圧力（ポンプ吐出圧力Ｐｐ）を圧力信号に変換し、コントローラ４０に出力する。 The pressure sensor 27 is provided on the upstream side of the bleed-off closing valve 25 of the pump discharge oil passage 28, converts the pressure of the pump discharge oil passage 28 (pump discharge pressure Pp) into a pressure signal, and outputs it to the controller 40.
　コントローラ４０は、ポンプ漏れ流量の測定指令を受けて、ブリードオフ閉鎖バルブ２５、エンジン２０の回転数（以下、エンジン回転数）Ｎｅｎｇ、ポンプ傾転ｑｐを制御し、圧力センサ２７で検出したポンプ吐出圧力Ｐｐに基づいて、油圧ポンプ２１の漏れ流量Ｑｌｅａｋを算出する。 The controller 40 receives a command for measuring the pump leakage flow rate, controls the bleed-off closing valve 25, the engine rotation speed (hereinafter referred to as engine rotation speed) Neng, and the pump tilt qp, and discharges the pump detected by the pressure sensor 27. The leakage flow rate Qleak of the hydraulic pump 21 is calculated based on the pressure Pp.
　建設機械用の油圧ポンプとしてはアキシャルピストンタイプのポンプが多く用いられており、可変容量機構として斜軸タイプと斜板タイプとがある。どちらもピストンのストローク工程を変化させて押しのけ容積を変化させることで可変容量を実現している。 Axial piston type pumps are often used as hydraulic pumps for construction machinery, and there are diagonal shaft type and swash plate type as variable capacitance mechanism. In both cases, the variable capacitance is realized by changing the stroke process of the piston to change the push-out volume.
　片傾転型可変容量式の油圧ポンプ２１の一例として、図３に可変容量型斜軸式油圧ポンプの構造を示す。 As an example of the unilateral tilt type variable displacement hydraulic pump 21, the structure of the variable displacement oblique shaft hydraulic pump is shown in FIG.
　図３において、筒状のケーシング１は、一端側が軸受部分となった略円筒状のケーシング本体１Ａと、ケーシング本体１Ａの他端側を閉塞したヘッドケーシング１Ｂとから構成されている。 In FIG. 3, the tubular casing 1 is composed of a substantially cylindrical casing main body 1A having a bearing portion on one end side and a head casing 1B in which the other end side of the casing main body 1A is closed.
　回転軸２は、ケーシング本体１Ａ内に回転可能に設けられている。シリンダブロック３は、ケーシング本体１Ａ内に位置して回転軸２と共に回転する。シリンダブロック３には、その軸方向に複数のシリンダ４が穿設されている。そして、各シリンダ４内にはそれぞれピストン５が摺動可能に設けられ、各ピストン５にはコネクティングロッド６が取り付けられている。 The rotating shaft 2 is rotatably provided in the casing body 1A. The cylinder block 3 is located in the casing body 1A and rotates together with the rotating shaft 2. A plurality of cylinders 4 are bored in the cylinder block 3 in the axial direction thereof. A piston 5 is slidably provided in each cylinder 4, and a connecting rod 6 is attached to each piston 5.
　また、各コネクティングロッド６の先端には球形部６Ａが形成され、各球形部６Ａは回転軸２の先端に形成されたドライブディスク７に揺動自在に支持されている。ここで、シリンダブロック３は後述の弁板８と共に回転軸２に対し傾転量としての傾転角θをもって配設され、この傾転角θによってポンプ押しのけ容量が決定される。 Further, a spherical portion 6A is formed at the tip of each connecting rod 6, and each spherical portion 6A is swingably supported by a drive disk 7 formed at the tip of the rotating shaft 2. Here, the cylinder block 3 is arranged together with the valve plate 8 described later with a tilt angle θ as a tilt amount with respect to the rotation shaft 2, and the pump push-off capacity is determined by this tilt angle θ.
　弁板８は、その一側端面にシリンダブロック３が摺接し、弁板８の他側端面はヘッドケーシング１Ｂに形成された凹湾曲状の傾転摺動面９に摺接している。 The cylinder block 3 is in sliding contact with the one side end surface of the valve plate 8, and the other side end surface of the valve plate 8 is in sliding contact with the concavely curved tilting sliding surface 9 formed in the head casing 1B.
　また、弁板８の中心には貫通孔８Ａが穿設され、貫通孔８Ａには後述するセンタシャフト１０と揺動ピン１５の各先端部が両側からそれぞれ挿入されている。そして、弁板８にはシリンダブロック３の回転時に各シリンダ４と間歇的に連通する一対の給排ポート（図示せず）が穿設され、ヘッドケーシング１Ｂの傾転摺動面９に開口する一対の給排通路（図示せず）はこれらの給排ポートに弁板８の傾転位置（傾転角θ）の如何に拘らず連通するようになっている。 Further, a through hole 8A is bored in the center of the valve plate 8, and the tip portions of the center shaft 10 and the swing pin 15, which will be described later, are inserted into the through hole 8A from both sides. A pair of supply / discharge ports (not shown) that intermittently communicate with each cylinder 4 when the cylinder block 3 rotates are bored in the valve plate 8 and opens to the tilting sliding surface 9 of the head casing 1B. A pair of supply / discharge passages (not shown) communicate with these supply / discharge ports regardless of the tilt position (tilt angle θ) of the valve plate 8.
　センタシャフト１０は、ドライブディスク７と弁板８との間でシリンダブロック３を支持する。センタシャフト１０の一端側には球形部１０Ａが形成され、球形部１０Ａはドライブディスク７の軸中心位置に揺動自在に支持されている。一方、シリンダブロック３の中心を貫通して突出したセンタシャフト１０の他端側は弁板８の貫通孔８Ａ内に摺動可能に挿入され、シリンダブロック３を弁板８に対してセンタリングするようになっている。 The center shaft 10 supports the cylinder block 3 between the drive disk 7 and the valve plate 8. A spherical portion 10A is formed on one end side of the center shaft 10, and the spherical portion 10A is swingably supported at the axial center position of the drive disk 7. On the other hand, the other end side of the center shaft 10 protruding through the center of the cylinder block 3 is slidably inserted into the through hole 8A of the valve plate 8 so that the cylinder block 3 is centered with respect to the valve plate 8. It has become.
　傾転機構１１は、傾転摺動面９に沿って弁板８を傾転させる。傾転機構１１は、ヘッドケーシング１Ｂ内に形成され、軸方向両端側に油通孔１２Ａ，１２Ｂを有したシリンダ室１２と、シリンダ室１２内に摺動可能に挿嵌され、シリンダ室１２内に液圧室１３Ａ，１３Ｂを画成したサーボピストン１４と、基端側がサーボピストン１４に固着され、先端側が球形状先端部１５Ａとなって弁板８の貫通孔８Ａに揺動可能に挿嵌された揺動ピン１５とから構成されている。 The tilting mechanism 11 tilts the valve plate 8 along the tilting sliding surface 9. The tilting mechanism 11 is slidably inserted into the cylinder chamber 12 which is formed in the head casing 1B and has oil passage holes 12A and 12B on both ends in the axial direction, and is slidably inserted in the cylinder chamber 12. The servo piston 14 defining the hydraulic chambers 13A and 13B and the base end side are fixed to the servo piston 14, and the tip side becomes a spherical tip portion 15A and is swingably inserted into the through hole 8A of the valve plate 8. It is composed of a swing pin 15 and a cylinder.
　制御部１６は、傾転機構１１を介して弁板８を傾転制御する。制御部１６は、ヘッドケーシング１Ｂの外側に設けられ、パイロットポンプから給排される圧油量（パイロット圧）をフィードバック制御する絞り切換弁（いずれも図示せず）を備えている。そして、この絞り切換弁にはスリーブ（図示せず）が設けられ、このスリーブとサーボピストン１４とは、ヘッドケーシング１Ｂの長孔１Ｃに挿通されたフィードバックピン１７によって一体的に連結されている。 The control unit 16 tilts and controls the valve plate 8 via the tilting mechanism 11. The control unit 16 is provided on the outside of the head casing 1B, and includes a throttle switching valve (neither shown) that feedback-controls the amount of pressure oil supplied / discharged from the pilot pump (pilot pressure). A sleeve (not shown) is provided on the throttle switching valve, and the sleeve and the servo piston 14 are integrally connected by a feedback pin 17 inserted into a long hole 1C of the head casing 1B.
　ここで、制御部１６の絞り切換弁を操作レバー等で切換操作すると、このときの切換操作量に応じた圧油（パイロット圧）が前記パイロットポンプから前記油通孔１２Ａ，１２Ｂを介して傾転機構１１の液圧室１３Ａ，１３Ｂ内に給排され、液圧室１３Ａ，１３Ｂ間の圧力差でサーボピストン１４を摺動変位させることにより、サーボピストン１４は揺動ピン１５を介して弁板８およびシリンダブロック３を傾転角θをもって矢示Ａ方向に傾転させる。そして、前記絞り切換弁のスリーブはサーボピストン１４の変位に追従して変位することにより、前記パイロットポンプからの圧油量をフィードバック制御し、サーボピストン１４の変位量を絞り切換弁の切換操作量に対応させた状態に保持する。 Here, when the throttle switching valve of the control unit 16 is switched by an operation lever or the like, the pressure oil (piston pressure) corresponding to the switching operation amount at this time is tilted from the pilot pump via the oil passage holes 12A and 12B. The servo piston 14 is supplied and discharged into the hydraulic chambers 13A and 13B of the rolling mechanism 11, and the servo piston 14 is slidably displaced by the pressure difference between the hydraulic chambers 13A and 13B, so that the servo piston 14 is valved via the swing pin 15. The plate 8 and the cylinder block 3 are tilted in the direction of arrow A with a tilt angle θ. Then, the sleeve of the throttle switching valve is displaced according to the displacement of the servo piston 14, so that the pressure oil amount from the pilot pump is feedback-controlled, and the displacement amount of the servo piston 14 is the switching operation amount of the throttle switching valve. Hold in the state corresponding to.
　このような構成を備えたアキシャルピストンタイプの可変容量型油圧ポンプにおいては、斜軸、または斜板ポンプにおいては斜板の傾き量（以下、傾転）を変更可能とすることにより１回転当たりのピストンの押しのけ量を変更して、ポンプの吐出流量を可変とすることができる。よってこの斜軸または斜板の傾転量の制御でポンプ吐出量を制御することが可能で、そのポンプ機構の姿勢が制御される。 In the axial piston type variable displacement hydraulic pump having such a configuration, the swash plate or the swash plate tilt amount (hereinafter referred to as tilt) can be changed in the swash plate pump to change the tilt amount per rotation. The discharge flow rate of the pump can be made variable by changing the amount of push-out of the piston. Therefore, it is possible to control the pump discharge amount by controlling the tilt amount of the swash plate or the swash plate, and the posture of the pump mechanism is controlled.
　一方、図示は省略するが、両傾転型ポンプは傾転角を両方向に振れるようにすることが必要で、機能的な面も増えることもあり、大きく構造が異なり部品が増えてコスト的にも高価なものになる。さらに、両傾転型ポンプは吸い込み性能も悪く利用上好ましくない面もあり、また補器への油の循環・潤滑のためにチャージ回路が必要になる。したがって両傾転型ポンプを片傾転で使用するようなことは実用上行われず、ショベルのように片傾転型ポンプで仕様を満たす機械であれば片傾転ポンプ型を使用するのが当然となっている。 On the other hand, although not shown, it is necessary for the double tilt type pump to swing the tilt angle in both directions, which may increase the functional aspect, and the structure is significantly different and the number of parts increases, which is cost effective. Will also be expensive. Further, the double tilt type pump has poor suction performance and is not preferable in terms of use, and a charge circuit is required for circulation and lubrication of oil to the auxiliary device. Therefore, it is not practical to use a double tilt pump in one tilt, and it is natural to use a single tilt pump type if the machine meets the specifications with a single tilt pump such as a shovel. It has become.
　次に、ポンプの吐出漏れについて説明する。 Next, the discharge leakage of the pump will be described.
　ポンプの主要な可動部、摺動部としては上述したように、軸受けや各ピストン５と各シリンダ４との摺動、シリンダブロック３と弁板８の摺動部、弁板８とヘッドケーシング１Ｂとの摺動等が挙げられる。ポンプからの吐出油はこのシリンダブロック３から弁板８を経由して吐出ポート（図示しない）に移送されることになり、これら摺動部が摺動に際して潤滑不良等が起きると摩耗等が発生して傾転摺動面の隙間が大きくなる。この隙間が追加され部品間クリアランスが正常時の規定量よりも大きくなることになりポンプの吐出油がその隙間から低圧部へ流れ出る（漏れる）ことになる。その結果、ポンプの吐出流量が正常時の吐出流量よりも漏れ流量分減少してしまうことになる。 As described above, the main moving parts and sliding parts of the pump are bearings, sliding parts of each piston 5 and each cylinder 4, sliding parts of cylinder block 3 and valve plate 8, valve plate 8 and head casing 1B. Sliding with and the like can be mentioned. The oil discharged from the pump is transferred from the cylinder block 3 to the discharge port (not shown) via the valve plate 8, and if these sliding parts slide and lubrication failure occurs, wear or the like occurs. As a result, the gap between the tilting and sliding surfaces becomes large. This gap is added, and the clearance between parts becomes larger than the specified amount at the normal time, and the discharged oil of the pump flows out (leaks) from the gap to the low pressure part. As a result, the discharge flow rate of the pump is reduced by the leakage flow rate from the normal discharge flow rate.
　理論ポンプ吐出流量、漏れ流量、およびポンプ吐出圧力の関係について以下に説明する。ここでいう理論ポンプ吐出流量とは、ポンプの漏れ流量がゼロと仮定した場合のポンプ吐出流量である。 The relationship between the theoretical pump discharge flow rate, leakage flow rate, and pump discharge pressure will be explained below. The theoretical pump discharge flow rate referred to here is a pump discharge flow rate assuming that the leakage flow rate of the pump is zero.
　油圧駆動装置２００内の各流量とポンプ吐出圧力Ｐｐとの関係は、以下の式で表される。 The relationship between each flow rate in the hydraulic drive device 200 and the pump discharge pressure Pp is expressed by the following equation.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
Qpref：理論ポンプ吐出流量
Qleak：ポンプ漏れ流量
Qrelief：リリーフ流量
Qcb：センタバイパス流量（ブリードオフ流量）
B：体積弾性係数
V：ポンプ吐出部容積
　また、理論ポンプ吐出流量Ｑｐｒｅｆは、以下の式で表される。 Qpref: Theoretical pump discharge flow rate
Qleak: Pump leak flow rate
Qrelief: Relief flow rate
Qcb: Center bypass flow rate (bleed-off flow rate)
B: Volume modulus
V: Pump discharge volume The theoretical pump discharge flow rate Qpref is expressed by the following equation.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　式（１）において、ポンプ吐出圧力Ｐｐがリリーフ設定圧Ｐｒより低い状態では、リリーフ流量Ｑｒｅｌｉｅｆはゼロになる。また、ブリードオフ閉鎖バルブ２５を閉じた状態では、センタバイパス流量Ｑｃｂはゼロになる。さらに、ポンプ吐出圧力Ｐｐが安定した状態ではポンプ吐出圧力Ｐｐの変化率ｄＰｐ／ｄｔは十分に小さくなる。このような回路状態では、理論ポンプ吐出流量Ｑｐｒｅｆはポンプ漏れ流量Ｑｌｅａｋに等しくなる。従って、そのような回路状態における理論ポンプ吐出流量Ｑｐｒｅｆを算出することにより、ポンプ漏れ流量Ｑｌｅａｋを測定することができる。 In the formula (1), when the pump discharge pressure Pp is lower than the relief set pressure Pr, the relief flow rate Qrelief becomes zero. Further, when the bleed-off closing valve 25 is closed, the center bypass flow rate Qcb becomes zero. Further, when the pump discharge pressure Pp is stable, the rate of change dPp / dt of the pump discharge pressure Pp becomes sufficiently small. In such a circuit state, the theoretical pump discharge flow rate Qpref is equal to the pump leak flow rate Qleak. Therefore, the pump leakage flow rate Qleak can be measured by calculating the theoretical pump discharge flow rate Qpref in such a circuit state.
　ここで測定したい漏れ流量Ｑｌｅａｋの程度について補足する。建設機械等で用いられる一般的なアキシャルピストンポンプでの容積効率ηｖは定格運転時でおよそ８５～９５％程度であり、漏れの少ない良好なポンプを想定して容積効率ηｖを９５％とすると、２０ｔ級油圧ショベルのポンプ吐出流量は約２００Ｌ／ｍｉｎであるからその漏れ流量は、
　２００Ｌ／ｍｉｎ×５％＝１０Ｌ／ｍｉｎ
となる。 Here, the degree of leakage flow rate Qleak to be measured is supplemented. The volumetric efficiency ηv of a general axial piston pump used in construction machinery is about 85 to 95% at the time of rated operation, and assuming a good pump with little leakage, the volumetric efficiency ηv is 95%. Since the pump discharge flow rate of the 20t class hydraulic excavator is about 200L / min, the leakage flow rate is
200L / min x 5% = 10L / min
Will be.
　エンジン回転数を定格回転数（２０００ｒｐｍ）とすると、５％の漏れ流量相当を吐出するためのポンプ傾転は、
　１０Ｌ／ｍｉｎ／２０００ｒｐｍ×１０００ｃｍ３／Ｌ＝５ｃｍ３／ｒｅｖ
となる。 Assuming that the engine speed is the rated speed (2000 rpm), the pump tilt for discharging the equivalent of 5% leakage flow rate is
10L / min / 2000rpm x 1000cm 3 / L = 5cm 3 / rev
Will be.
　ここで、エンジン回転数を最小回転数（例えば１０００ｒｐｍ）まで低下させると、５％の漏れ流量相当を吐出するためのポンプ傾転は、
　１０Ｌ／ｍｉｎ／１０００ｒｐｍ×１０００ｃｍ３／Ｌ＝１０ｃｍ３／ｒｅｖ
となり、定格回転数の場合よりの大きくなる。 Here, when the engine speed is reduced to the minimum speed (for example, 1000 rpm), the pump tilt for discharging a leakage flow rate equivalent to 5% is increased.
10L / min / 1000rpm x 1000cm 3 / L = 10cm 3 / rev
It becomes larger than the case of the rated rotation speed.
　しかし、このようにエンジン回転数を最小回転数まで低下させても、５％の漏れ流量相当を吐出するためのポンプ傾転は、最大傾転（１００ｃｍ３／ｒｅｖ）の１／１０まで抑える必要がある。 However, even if the engine speed is reduced to the minimum speed in this way, the pump tilt for discharging the equivalent of 5% leakage flow rate needs to be suppressed to 1/10 of the maximum tilt (100 cm 3 / rev). There is.
　特許文献１では、両傾転型ポンプを対象としているため、ポンプ吐出流量をゼロから自在に変化させることができるが、先に述べた片傾転型ポンプのスタンバイ流量を５０Ｌ／ｍｉｎとすると、エンジン定格運転時（２０００ｒｐｍ）にスタンバイ流量を吐出するための傾転（スタンバイ傾転）は、
　５０Ｌ／ｍｉｎ／２０００ｒｐｍ×１０００ｃｍ３／Ｌ＝２５ｃｍ３／ｒｅｖ
となり、５％の漏れ流量を測定するためのポンプ傾転（５ｃｍ３／ｒｅｖ）の５倍に相当する。また、エンジン回転数をアイドリング回転数（１０００ｒｐｍ）まで落としたとしても、５％の漏れ流量を測定するための傾転（１０ｃｍ３／ｒｅｖ）の２．５倍に相当する。従って、スタンバイ傾転を最小傾転とするシステムでは、片傾転型ポンプの吐出流量を５％の漏れ流量相当まで低下させることはできない。 Since Patent Document 1 targets a double tilting pump, the pump discharge flow rate can be freely changed from zero. However, assuming that the standby flow rate of the single tilting pump described above is 50 L / min, The tilt (standby tilt) for discharging the standby flow rate during engine rated operation (2000 rpm) is
50L / min / 2000rpm x 1000cm 3 / L = 25cm 3 / rev
This is equivalent to 5 times the pump tilt (5 cm 3 / rev) for measuring the leak flow rate of 5%. Further, even if the engine speed is reduced to the idling speed (1000 rpm), it corresponds to 2.5 times the tilt (10 cm 3 / rev) for measuring the leakage flow rate of 5%. Therefore, in a system in which the standby tilt is the minimum tilt, the discharge flow rate of the one-side tilt type pump cannot be reduced to the equivalent of a leakage flow rate of 5%.
　そこで本実施の形態では、ポンプの最小傾転を以下のように通常運転時と漏れ診断時で切り替えられるように構成する。 Therefore, in the present embodiment, the minimum tilt of the pump is configured to be switched between normal operation and leak diagnosis as follows.
　通常運転時　　　　最小傾転（スタンバイ傾転）ｑｐｓ＝２５ｃｍ３／ｒｅｖ
　漏れ診断運転時　　最小傾転（診断用傾転）ｑｐｄ＝１０ｃｍ３／ｒｅｖ
　以上の関係をまとめると、診断用傾転ｑｐｄは、建設機械の油圧負荷運転可能な最小エンジン回転数Ｎｅｎｇ＿ｍｉｎ（通常はアイドリング回転数）および測定可能な最小漏れ流量Ｑｌｅａｋ＿ｍｉｎに対し、以下の条件を満たす必要がある。 Minimum tilt (standby tilt) qps = 25cm 3 / rev during normal operation
Minimum tilt during leak diagnosis operation (diagnosis tilt) qpd = 10 cm 3 / rev
Summarizing the above relationship, the diagnostic tilt qpd satisfies the following conditions with respect to the minimum engine speed Neng_min (usually idling speed) and the measurable minimum leakage flow rate Qleak_min that can be operated under hydraulic load of construction machinery. There is a need.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　このように診断用傾転ｑｐｄを設定することにより、エンジン回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎまで低下させることでポンプ吐出流量を最小漏れ流量Ｑｌｅａｋ＿ｍｉｎ以下に抑えることができるため、最小漏れ流量Ｑｌｅａｋ＿ｍｉｎを測定することが可能となる。 By setting the diagnostic tilt qpd in this way, the pump discharge flow rate can be suppressed to the minimum leakage flow rate Qleak_min or less by lowering the engine speed Neng to the minimum rotation speed Neng_min, so the minimum leakage flow rate Qleak_min is measured. It becomes possible to do.
　図４にコントローラ４０の機能ブロックを示す。なお、図４中、油圧ポンプ２１の漏れ流量の測定に係わる構成のみを示し、アクチュエータ１０７～１０９の駆動に係わる構成は省略している。 FIG. 4 shows the functional block of the controller 40. In FIG. 4, only the configuration related to the measurement of the leakage flow rate of the hydraulic pump 21 is shown, and the configuration related to the driving of the actuators 107 to 109 is omitted.
　図４において、コントローラ４０は、測定制御部４１と、バルブ制御部４２と、エンジン回転数制御部４３と、ポンプ傾転制御部４４と、ポンプ流量算出部４５と、ポンプ圧力計測部４６と、漏れ流量算出部４７とを備えている。 In FIG. 4, the controller 40 includes a measurement control unit 41, a valve control unit 42, an engine rotation speed control unit 43, a pump tilt control unit 44, a pump flow rate calculation unit 45, a pump pressure measurement unit 46, and the like. It is provided with a leak flow rate calculation unit 47.
　測定制御部４１は、漏れ流量Ｑｌｅａｋの測定を開始する測定指令を受けて、バルブ制御部４２、エンジン回転数制御部４３、およびポンプ傾転制御部４４を制御する。測定指令は、運転室１１０に配置されたスイッチ等の入力装置（図示せず）の操作を介して生成させても良いし、油圧ショベル１００のエンジン２０が始動してコントローラ４０の電源が入った直後に自動的に生成させても良い。 The measurement control unit 41 controls the valve control unit 42, the engine speed control unit 43, and the pump tilt control unit 44 in response to the measurement command for starting the measurement of the leakage flow rate Qleak. The measurement command may be generated via the operation of an input device (not shown) such as a switch arranged in the driver's cab 110, or the engine 20 of the hydraulic excavator 100 is started and the power of the controller 40 is turned on. Immediately after that, it may be automatically generated.
　バルブ制御部４２は、測定制御部４１からの指令に基づいて、ブリードオフ閉鎖バルブ２５を開閉する。 The valve control unit 42 opens and closes the bleed-off closing valve 25 based on a command from the measurement control unit 41.
　エンジン回転数制御部４３は、測定制御部４１からの指令に基づいて、エンジン回転数Ｎｅｎｇが所望の値となるようにエンジン２０を制御する。 The engine speed control unit 43 controls the engine 20 so that the engine speed Neng becomes a desired value based on a command from the measurement control unit 41.
　ポンプ傾転制御部４４は、測定制御部４１からの指令に基づいて、油圧ポンプ２１の傾転ｑｐが所望の値となるように、電磁比例弁２３の開度を調節し、傾転制御装置２２を駆動する。 The pump tilt control unit 44 adjusts the opening degree of the electromagnetic proportional valve 23 so that the tilt qp of the hydraulic pump 21 becomes a desired value based on the command from the measurement control unit 41, and the tilt control unit 44 adjusts the opening degree of the electromagnetic proportional valve 23. Drive 22.
　ポンプ流量算出部４５は、エンジン回転数制御部４３からのエンジン回転数Ｎｅｎｇとポンプ傾転制御部４４からのポンプ傾転量ｑｐとに基づいて、理論ポンプ吐出流量Ｑｐｒｅｆを算出し、漏れ流量算出部４７に出力する。 The pump flow rate calculation unit 45 calculates the theoretical pump discharge flow rate Qpref based on the engine speed Neng from the engine speed control unit 43 and the pump tilt amount qp from the pump tilt control unit 44, and calculates the leakage flow rate. Output to unit 47.
　ポンプ圧力計測部４６は、圧力センサ２７からの圧力信号を油圧ポンプ２１のポンプ吐出圧力Ｐｐに変換し、漏れ流量算出部４７に出力する。 The pump pressure measuring unit 46 converts the pressure signal from the pressure sensor 27 into the pump discharge pressure Pp of the hydraulic pump 21 and outputs it to the leakage flow rate calculation unit 47.
　漏れ流量算出部４７は、ポンプ流量算出部４５からの理論ポンプ吐出流量Ｑｐｒｅｆとポンプ圧力計測部４６からのポンプ吐出圧力Ｐｐとに基づいて漏れ流量Ｑｌｅａｋを算出し、運転室１１０に配置されたモニタ５０等に出力する。なお、漏れ流量Ｑｌｅａｋは、運転室１１０の作業者に限らず、車両管理者やサービス部門等に通知されるように構成しても良い。 The leakage flow rate calculation unit 47 calculates the leakage flow rate Qleak based on the theoretical pump discharge flow rate Qpref from the pump flow rate calculation unit 45 and the pump discharge pressure Pp from the pump pressure measurement unit 46, and monitors arranged in the cab 110. Output to 50 mag. The leak flow rate Qleak may be configured to be notified not only to the worker in the driver's cab 110 but also to the vehicle manager, the service department, and the like.
　図５にコントローラ４０によって実行されるポンプ漏れ流量の測定フローを示す。コントローラ４０は、ポンプ漏れ流量の測定指令が入力されると、通常の制御フロー（図示せず）を中断し、当該測定フローに移行する。以下、当該測定フローを構成する各ステップについて順に説明する。 FIG. 5 shows the measurement flow of the pump leakage flow rate executed by the controller 40. When the pump leakage flow rate measurement command is input, the controller 40 interrupts the normal control flow (not shown) and shifts to the measurement flow. Hereinafter, each step constituting the measurement flow will be described in order.
　コントローラ４０は、先ず、ポンプ傾転ｑｐをスタンバイ傾転ｑｐｓよりも小さい診断用傾転ｑｐｄに設定し、エンジン回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎに設定する（ステップＳ１）。これにより、油圧ポンプ２１の吐出流量は微小流量（正常な油圧ポンプの漏れ流量相当）になる。 First, the controller 40 sets the pump tilt qp to the diagnostic tilt qpd smaller than the standby tilt qps, and sets the engine speed Neng to the minimum speed Neng_min (step S1). As a result, the discharge flow rate of the hydraulic pump 21 becomes a minute flow rate (corresponding to the leakage flow rate of the normal hydraulic pump).
　ステップＳ１に続き、ブリードオフ閉鎖バルブ２５を閉じる（ステップＳ２）。これにより、ポンプ吐出油路２８が遮断され、油圧ポンプ２１から方向切換弁ユニット２４への圧油の供給が停止する。すなわち、油圧ポンプ２１からタンク２９に排出されるブリードオフ流量はゼロになる。 Following step S1, the bleed-off closing valve 25 is closed (step S2). As a result, the pump discharge oil passage 28 is shut off, and the supply of pressure oil from the hydraulic pump 21 to the directional control valve unit 24 is stopped. That is, the bleed-off flow rate discharged from the hydraulic pump 21 to the tank 29 becomes zero.
　ステップＳ２に続き、エンジン回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから最大回転数Ｎｅｎｇ＿ｍａｘまで緩やかに上昇させる制御を開始する（ステップＳ３）。ここでいう「緩やかに上昇」とは、式（１）における各流量の変動によるポンプ吐出圧力Ｐｐの変化率ｄＰｐ／ｄｔが十分に小さくなるような上昇速度であり、例えば数十秒程度の時間をかけてエンジン回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから最大回転数Ｎｅｎｇ＿ｍａｘまで上昇させることである。これにより、油圧ポンプ２１の吐出流量が緩やかに増加する。 Following step S2, control for gradually increasing the engine speed Neng from the minimum speed Neng_min to the maximum speed Neng_max is started (step S3). The "gradual rise" referred to here is a rise speed at which the rate of change dPp / dt of the pump discharge pressure Pp due to the fluctuation of each flow rate in the equation (1) becomes sufficiently small, for example, a time of about several tens of seconds. The engine speed Neng is increased from the minimum speed Neng_min to the maximum speed Neng_max. As a result, the discharge flow rate of the hydraulic pump 21 gradually increases.
　ステップＳ３に続き、ポンプ吐出圧力Ｐｐを計測する（ステップＳ４）。 Following step S3, the pump discharge pressure Pp is measured (step S4).
　ステップＳ４に続き、ポンプ吐出圧力Ｐｐが所定の閾値Ｐｓ以上か否かを判定する（ステップＳ５）。ここで、閾値Ｐｓは、リリーフ弁２６のリリーフ設定圧Ｐｒ（例えば３５ＭＰａ）よりも小さくかつ比較的大きい値（例えば３０ＭＰａ）に設定することが望ましい。閾値Ｐｓを比較的大きい値に設定することにより、測定時の回路圧力が安定し、また、傾転摺動面９の隙間が小さい場合でも漏れ流量Ｑｌｅａｋが大きくなるため、漏れ流量Ｑｌｅａｋの測定精度を向上させることができる。 Following step S4, it is determined whether or not the pump discharge pressure Pp is equal to or higher than a predetermined threshold value Ps (step S5). Here, it is desirable that the threshold value Ps is set to a value (for example, 30 MPa) that is smaller and relatively larger than the relief set pressure Pr (for example, 35 MPa) of the relief valve 26. By setting the threshold value Ps to a relatively large value, the circuit pressure at the time of measurement is stable, and the leakage flow rate Qleak is large even when the gap between the tilting sliding surfaces 9 is small, so that the measurement accuracy of the leakage flow rate Qleak is large. Can be improved.
　ステップＳ５でポンプ吐出圧力Ｐｐが所定の閾値Ｐｓ未満である（Ｎｏ）と判定した場合は、ステップＳ４に戻る。 If it is determined in step S5 that the pump discharge pressure Pp is less than the predetermined threshold value Ps (No), the process returns to step S4.
　ステップＳ５でポンプ吐出圧力Ｐｐが所定の閾値Ｐｓ以上である（Ｙｅｓ）と判定した場合は、ステップＳ３で開始したエンジン回転数Ｎｅｎｇを緩やかに上昇させる制御を停止する（ステップＳ６）。 When it is determined in step S5 that the pump discharge pressure Pp is equal to or higher than the predetermined threshold value Ps (Yes), the control for gradually increasing the engine speed Neng started in step S3 is stopped (step S6).
　ステップＳ６に続き、診断用傾転ｑｐｄおよび現在のエンジン回転数Ｎｅｎｇに基づいて理論ポンプ吐出流量Ｑｐｒｅｆを算出し、漏れ流量Ｑｌｅａｋとしてモニタ５０等に出力する（ステップＳ７）。 Following step S6, the theoretical pump discharge flow rate Qpref is calculated based on the diagnostic tilt qpd and the current engine speed Neng, and is output to the monitor 50 or the like as the leak flow rate Qleak (step S7).
　ステップＳ７に続き、ブリードオフ閉鎖バルブ２５を開き（ステップＳ８）、当該フローを終了する（通常の制御フローに復帰する）。 Following step S7, the bleed-off closing valve 25 is opened (step S8) to end the flow (return to the normal control flow).
　本実施例では、原動機２０と、作動油を貯留するタンク２９と、原動機２０によって駆動され、タンク２９から吸い込んだ作動油を吐出する片傾転型可変容量式の油圧ポンプ２１と、複数の油圧アクチュエータ１０７～１０９と、油圧ポンプ２１の吐出油が供給される吐出油路２８に接続され、油圧ポンプ２１から複数の油圧アクチュエータ１０７～１０９に供給される作動油の流れを制御する方向切換弁ユニット２４と、原動機２０の回転数Ｎｅｎｇおよび油圧ポンプ２１の傾転ｑｐを制御するコントローラ４０とを備えた建設機械１００において、油圧ポンプ２１の吐出圧力Ｐｐを検出する圧力センサ２７を備え、コントローラ４０は、吐出油路２８とタンク２９との連通を遮断し、かつ油圧ポンプ２１の傾転ｑｐをスタンバイ傾転ｑｐｓよりも小さく設定された診断用傾転ｑｐｄに保持した状態で、原動機２０の回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから上昇させつつ油圧ポンプ２１の吐出圧力Ｐｐを計測し、油圧ポンプ２１の吐出圧力Ｐｐが所定の圧力Ｐｓに達したときの原動機２０の回転数Ｎｅｎｇと診断用傾転ｑｐｓとに基づいて油圧ポンプ２１の漏れ流量Ｑｌｅａｋを算出する。 In this embodiment, a prime mover 20, a tank 29 for storing hydraulic oil, a unilateral tilting type variable displacement hydraulic pump 21 driven by the prime mover 20 and discharging hydraulic oil sucked from the tank 29, and a plurality of hydraulic pumps. A direction switching valve unit that is connected to the actuators 107 to 109 and the discharge oil passage 28 to which the discharge oil of the hydraulic pump 21 is supplied and controls the flow of hydraulic oil supplied from the hydraulic pump 21 to the plurality of hydraulic actuators 107 to 109. In the construction machine 100 including the 24 and the controller 40 for controlling the rotation speed Neng of the prime mover 20 and the tilt qp of the hydraulic pump 21, the controller 40 includes a pressure sensor 27 for detecting the discharge pressure Pp of the hydraulic pump 21. , The rotation speed of the prime mover 20 in a state where the communication between the discharge oil passage 28 and the tank 29 is cut off and the tilt qp of the hydraulic pump 21 is held at the diagnostic tilt qpd set smaller than the standby tilt qps. The discharge pressure Pp of the hydraulic pump 21 is measured while raising the Neng from the minimum rotation speed Neng_min, and the rotation speed Neng of the prime mover 20 and the tilt qps for diagnosis when the discharge pressure Pp of the hydraulic pump 21 reaches a predetermined pressure Ps. Based on the above, the leakage flow rate Qleak of the hydraulic pump 21 is calculated.
　以上のように構成された本実施例によれば、油圧ポンプ２１の吐出油路２８とタンク２９との連通を遮断した状態（ブリードオフ流量およびリリーフ流量がゼロの状態）で、油圧ポンプ２１の傾転ｑｐをスタンバイ傾転ｑｐｓよりも小さい診断用傾転ｑｐｄに保持し、原動機２０の回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから上昇させ、油圧ポンプ２１の吐出圧力Ｐｐが所定の圧力Ｐｓに達したときの吐出流量を算出することにより、スタンバイ流量よりも小さい微小流量の範囲で油圧ポンプ２１の漏れ流量Ｑｌｅａｋを測定することができる。これにより、油圧ポンプ２１の予兆診断が可能となる。また、原動機２０の回転数Ｎｅｎｇを緩やかに上昇させることにより、漏れ流量Ｑｌｅａｋの測定精度を向上させることができる。なお、本実施例では、油圧ポンプ２１の吐出圧力を計測する際に、原動機２０の回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから上昇させる制御を行うこととしたが、原動機２０の回転数の制御方法はこれに限定されず、例えば最大回転数Ｎｅｎｇ＿ｍａｘから低下させる制御を行っても良い。 According to the present embodiment configured as described above, the hydraulic pump 21 is in a state where the communication between the discharge oil passage 28 of the hydraulic pump 21 and the tank 29 is cut off (a state in which the bleed-off flow rate and the relief flow rate are zero). The tilt qp was held in the diagnostic tilt qpd smaller than the standby tilt qps, the flow rate Neng of the prime mover 20 was raised from the minimum flow rate Neng_min, and the discharge pressure Pp of the hydraulic pump 21 reached a predetermined pressure Ps. By calculating the discharge flow rate at that time, the leakage flow rate Qleak of the hydraulic pump 21 can be measured in a minute flow rate range smaller than the standby flow rate. As a result, the predictive diagnosis of the hydraulic pump 21 becomes possible. Further, by gradually increasing the rotation speed Neng of the prime mover 20, the measurement accuracy of the leakage flow rate Qleak can be improved. In this embodiment, when measuring the discharge pressure of the hydraulic pump 21, the rotation speed Neng of the prime mover 20 is controlled to be increased from the minimum rotation speed Neng_min, but the control method of the rotation speed of the prime mover 20 is The present invention is not limited to this, and for example, control may be performed to reduce the maximum rotation speed from Neng_max.
　本発明の第２の実施例について、第１の実施例との相違点を中心に説明する。 The second embodiment of the present invention will be described focusing on the differences from the first embodiment.
　第１の実施例では、ブリードオフ閉鎖バルブ２５が油圧ポンプ２１のすぐ下流に位置しているため、方向切換弁ユニット２４等の影響を受けることなく油圧ポンプ２１の漏れ流量を測定することができる。しかし、油圧ポンプ２１の吐出油でアクチュエータ１０７～１０９を駆動する建設機械１００においては、油圧ポンプ２１単体ではなく方向切換弁ユニット２４も含めて漏れを評価することが好ましい場合もある。これは、油圧アクチュエータ１０７～１０９への圧油供給には油圧ポンプ２１だけでなく方向切換弁ユニット２４も大きく関わるからである。 In the first embodiment, since the bleed-off closing valve 25 is located immediately downstream of the hydraulic pump 21, the leakage flow rate of the hydraulic pump 21 can be measured without being affected by the direction switching valve unit 24 or the like. .. However, in the construction machine 100 in which the actuators 107 to 109 are driven by the discharge oil of the hydraulic pump 21, it may be preferable to evaluate the leakage including the direction switching valve unit 24 instead of the hydraulic pump 21 alone. This is because not only the hydraulic pump 21 but also the directional control valve unit 24 is greatly involved in the supply of pressure oil to the hydraulic actuators 107 to 109.
　図６は、本実施例における油圧駆動装置の回路図である。 FIG. 6 is a circuit diagram of the hydraulic drive device in this embodiment.
　図６において、油圧駆動装置２００は、エンジン（原動機）２０により駆動される可変容量式の第１および第２油圧ポンプ２１ａ，２１ｂと、第１油圧ポンプ２１ａの吐出側にパラレル接続される複数の方向切換弁２４ａ１からなる第１方向切換弁ユニット２４ａと、第２油圧ポンプ２１ｂの吐出側にパラレル接続される複数の方向切換弁２４ｂ１からなる第２方向切換弁ユニット２４ｂとを備えている。 In FIG. 6, the hydraulic drive system 200 is connected to a plurality of variable displacement type first and second hydraulic pumps 21a and 21b driven by the engine (motor) 20 in parallel to the discharge side of the first hydraulic pump 21a. It includes a first direction switching valve unit 24a composed of a direction switching valve 24a1 and a second direction switching valve unit 24b composed of a plurality of direction switching valves 24b1 connected in parallel to the discharge side of the second hydraulic pump 21b.
　第１方向切換弁ユニット２４ａを構成する複数の方向切換弁２４ａ１、および第２方向切換弁ユニット２４ｂを構成する複数の方向切換弁２４ｂ１はそれぞれ油圧アクチュエータ１０７～１０９，１２０Ｌ，１２０Ｒ，１２１のいずれかに接続されている。そして、各方向切換弁２４ａ１，２４ｂ１はパイロット方式（油圧式または電磁式）で切り換わるように構成されており、その切り換え操作は運転室１１０内に設けられた操作レバーや操作ペダル等の操作手段により行われる。また、第１および第２油圧ポンプ２１ａ，２１ｂからの圧油をタンク２９にバイパスするバイパスライン６０ａ，６０ｂには、第１および第２ブリードオフ閉鎖バルブ２５ａ，２５ｂが設けられている。第１および第２ブリードオフ閉鎖バルブ２５ａ，２５ｂは、コントローラ４０（図４に示す）からの指令によって第１および第２油圧ポンプ２１ａ，２１ｂからタンク２９にバイパスされる流量（以下、ブリードオフ流量）を制御する。 The plurality of directional switching valves 24a1 constituting the first directional switching valve unit 24a and the plurality of directional switching valves 24b1 constituting the second directional switching valve unit 24b are any of the hydraulic actuators 107 to 109, 120L, 120R, 121, respectively. It is connected to the. The direction switching valves 24a1, 24b1 are configured to be switched by a pilot method (hydraulic type or electromagnetic type), and the switching operation is performed by operating means such as an operating lever or an operating pedal provided in the driver's cab 110. Is done by. Further, the bypass lines 60a and 60b for bypassing the pressure oil from the first and second hydraulic pumps 21a and 21b to the tank 29 are provided with the first and second bleed- off closing valves 25a and 25b. The first and second bleed- off closing valves 25a and 25b are bypassed from the first and second hydraulic pumps 21a and 21b to the tank 29 by a command from the controller 40 (shown in FIG. 4) (hereinafter, bleed-off flow rate). ) Is controlled.
　ここで、油圧ショベル１００に設けられる油圧アクチュエータは、油圧モータからなる左右の走行モータ１２０Ｒ，１２０Ｌ及び旋回モータ１２１と、ブーム１０４を駆動するブームシリンダ１０７と、アーム１０５を駆動するアームシリンダ１０８と、バケット１０６を駆動するバケットシリンダ１０９とを含む。これら油圧アクチュエータのうち、ブームシリンダ１０７およびアームシリンダ１０８については、第１および第２油圧ポンプ２１ａ，２１ｂからの圧油を合流させて供給できるようにしている。なお、本実施例に係る油圧駆動装置２００は２台の油圧ポンプ２１ａ，２１ｂを備えているが、油圧ポンプの数は作業負荷等に応じて適宜変更可能である。 Here, the hydraulic actuators provided in the hydraulic excavator 100 include left and right traveling motors 120R and 120L composed of hydraulic motors, a swivel motor 121, a boom cylinder 107 for driving the boom 104, and an arm cylinder 108 for driving the arm 105. Includes a bucket cylinder 109 that drives the bucket 106. Among these hydraulic actuators, the boom cylinder 107 and the arm cylinder 108 are provided so that the pressure oils from the first and second hydraulic pumps 21a and 21b can be combined and supplied. The hydraulic drive system 200 according to this embodiment includes two hydraulic pumps 21a and 21b, but the number of hydraulic pumps can be appropriately changed according to the work load and the like.
　第１および第２油圧ポンプ２１ａ，２１ｂとタンク２９との間には、油圧回路の最高圧力を規制するためのリリーフ弁２６が設けられており、これにより油圧回路を構成する各部の保護が図られる。 A relief valve 26 for regulating the maximum pressure of the hydraulic circuit is provided between the first and second hydraulic pumps 21a and 21b and the tank 29, thereby protecting each part constituting the hydraulic circuit. Be done.
　本実施例は、方向切換弁ユニット２４の上流側に設けられたブリードオフ閉鎖バルブ２５（図２に示す）に代えて、方向切換弁ユニット２４ａ，２４ｂの下流側に設けられたブリードオフ閉鎖バルブ２５ａ，２５ｂを備えている点で第１の実施例と異なる。図６に示すように、アクチュエータへ供給される圧油の流れを制御する方向切換弁２４ａ１，２４ｂ１が各ポンプの供給ポートに対して並列に設けられており、これら方向切換弁２４ａ１，２４ｂ１からの圧油の漏れがポンプの漏れと同様にアクチュエータの駆動に影響を与える形となっている。 In this embodiment, instead of the bleed-off closing valve 25 (shown in FIG. 2) provided on the upstream side of the directional control valve unit 24, the bleed-off closing valve provided on the downstream side of the directional switching valve units 24a and 24b It differs from the first embodiment in that it includes 25a and 25b. As shown in FIG. 6, directional switching valves 24a1, 24b1 for controlling the flow of pressure oil supplied to the actuator are provided in parallel with the supply ports of each pump, and from these directional switching valves 24a1, 24b1. The leakage of pressure oil affects the drive of the actuator in the same way as the leakage of the pump.
　本実施例における油圧駆動装置２００の各流量とポンプ吐出圧力Ｐｐの関係は、以下の式で表される。 The relationship between each flow rate of the hydraulic drive device 200 and the pump discharge pressure Pp in this embodiment is expressed by the following equation.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
Qpref：理論ポンプ吐出流量
Qleak：ポンプ漏れ流量
Qrelief：リリーフ流量
Qcb：センタバイパス流量（ブリードオフ流量）
Qcv：方向切換弁漏れ流量
B：体積弾性係数
V：ポンプ吐出部容積
　ポンプ漏れ流量Ｑｌｅａｋの測定時に第１の実施例と同様に回路を制御した場合、式（４）は以下のようになる。 Qpref: Theoretical pump discharge flow rate
Qleak: Pump leak flow rate
Qrelief: Relief flow rate
Qcb: Center bypass flow rate (bleed-off flow rate)
Qcv: Direction switching valve leak flow rate
B: Volume modulus
V: Pump discharge volume When the circuit is controlled in the same manner as in the first embodiment when measuring the pump leakage flow rate Qleak, the equation (4) becomes as follows.
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　これよりポンプ漏れ流量Ｑｌｅａｋと方向切換弁漏れ流量Ｑｃｖの合計流量が理論ポンプ吐出流量Ｑｐｒｅｆとして算出されることになり、油圧ポンプ２１ａ，２１ｂおよび方向切換弁ユニット２４ａ，２４ｂを含む圧油供給系統全体の漏れ流量を測定することが可能となる。 From this, the total flow rate of the pump leakage flow rate Qleak and the direction switching valve leakage flow rate Qcv is calculated as the theoretical pump discharge flow rate Qpref, and the entire pressure oil supply system including the hydraulic pumps 21a and 21b and the direction switching valve units 24a and 24b It is possible to measure the leakage flow rate of.
　測定時の動作は第１の実施例と同様であるため説明を省略するが、これにより、圧油供給系統全体の漏れ流量を微小流量領域から測定できると共に、ブリードオフ流量がゼロ、リリーフ流量がゼロとなっている状況の下でポンプ吐出圧力が閾値（３０ＭＰａ）を緩やかに超えた時の理論ポンプ吐出流量Ｑｌｅａｋを通じて圧油供給系統の漏れ流量が精度良く測定され、建設機械の圧油の供給源としての損傷具合を評価することが可能となる。 Since the operation at the time of measurement is the same as that of the first embodiment, the description thereof will be omitted. However, by this, the leakage flow rate of the entire pressure oil supply system can be measured from a minute flow rate region, the bleed-off flow rate is zero, and the relief flow rate is reduced. The leakage flow rate of the pressure oil supply system is accurately measured through the theoretical pump discharge flow rate Qleak when the pump discharge pressure gradually exceeds the threshold (30 MPa) under the condition of zero, and the pressure oil supply of construction machinery is supplied. It becomes possible to evaluate the degree of damage as a source.
　本実施例における油圧ショベル１００は、方向切換弁ユニット２４ａ，２４ｂとタンク２９とを接続するバイパスライン６０ａ，６０ｂに設けられ、コントローラ４０からの制御信号に応じて開閉するブリードオフ閉鎖バルブ２５ａ，２５ｂを備え、コントローラ４０は、ブリードオフ閉鎖バルブ２５ａ，２５ｂを閉じることにより吐出油路２８ａ，２８ｂとタンク２９との連通を遮断する。 The hydraulic excavator 100 in this embodiment is provided on bypass lines 60a and 60b connecting the direction switching valve units 24a and 24b and the tank 29, and is a bleed- off closing valve 25a and 25b that opens and closes in response to a control signal from the controller 40. The controller 40 shuts off the communication between the discharge oil passages 28a and 28b and the tank 29 by closing the bleed- off closing valves 25a and 25b.
　以上のように構成した本実施例によれば、油圧ポンプ２１ａ，２１ｂの漏れ流量Ｑｌｅａｋと方向切換弁ユニット２４ａ，２４ｂの漏れ流量Ｑｃｖとの合計流量が算出されるため、油圧ポンプ２１ａ，２１ｂおよび方向切換弁ユニット２４ａ，２４ｂを含む圧油供給系統全体の微小な漏れ流量を測定することが可能となる。 According to the present embodiment configured as described above, the total flow rate of the leakage flow rate Qlake of the hydraulic pumps 21a and 21b and the leakage flow rate Qcv of the direction switching valve units 24a and 24b is calculated. It is possible to measure a minute leakage flow rate of the entire pressure oil supply system including the direction switching valve units 24a and 24b.
　本発明の第３の実施例について、第１の実施例との相違点を中心に説明する。
説明する。 The third embodiment of the present invention will be described focusing on the differences from the first embodiment.
explain.
　本実施例は通常の測定環境とは大きく異なる場合に、測定結果の評価、比較が不適当な場合における漏れ量の評価診断方法を提供することを目的としている。例えば具体的な例としては、極寒地での極寒状態で診断を実施した場合では油温が－２０℃などと非常に低い場合もある。この場合、ポンプの環状すきま等から漏れる流量は一般的に油の粘度等の影響を受けるので温度環境が漏れ具合に影響することが想定される。このように作動油の暖気の有無等でも大きく温度が異なる場合では、ポンプ毎に算出された漏れ流量を定量的に評価することは適切ではない。本実施例では、このように測定環境が大きく異なる場合において、評価に適した漏れ流量を算出する方法を説明する。 The purpose of this embodiment is to provide a method for evaluating and diagnosing the amount of leakage when the evaluation and comparison of measurement results are inappropriate when the measurement environment is significantly different from the normal measurement environment. For example, as a specific example, when the diagnosis is performed in a frigid state in a frigid region, the oil temperature may be very low, such as −20 ° C. In this case, the flow rate leaking from the annular gap of the pump is generally affected by the viscosity of the oil, etc., so it is assumed that the temperature environment affects the degree of leakage. When the temperature differs greatly depending on whether the hydraulic oil is warmed up or not, it is not appropriate to quantitatively evaluate the leak flow rate calculated for each pump. In this embodiment, a method of calculating a leak flow rate suitable for evaluation will be described when the measurement environment is significantly different.
　図６の油圧回路構成に示すように、油圧ショベルのような建設機械においては左右の走行モータ１２０Ｌ，１２０Ｒが存在するため、左右の等価性を得るために同一仕様の２つの油圧ポンプを備えるのが通例である。これら２つの油圧ポンプが損傷等がなく同様な漏れ流量特性を持っている場合であれば、温度等の環境が普段と大きく異なった場合であっても２つの油圧ポンプ２１ａ，２１ｂの漏れ流量は同等になるはずである。逆にいえば、２つの油圧ポンプ２１ａ，２ｂの漏れ流量が大きく異なる場合は、漏れ流量の大きい方の油圧ポンプが他方の油圧ポンプよりも損傷していると捉えることができる。 As shown in the hydraulic circuit configuration of FIG. 6, in a construction machine such as a hydraulic excavator, left and right traveling motors 120L and 120R exist, so that two hydraulic pumps having the same specifications are provided in order to obtain left-right equivalence. Is customary. If these two hydraulic pumps are not damaged and have similar leakage flow rate characteristics, the leakage flow rates of the two hydraulic pumps 21a and 21b will be high even if the environment such as temperature is significantly different from usual. Should be equivalent. Conversely, when the leakage flow rates of the two hydraulic pumps 21a and 2b are significantly different, it can be considered that the hydraulic pump having the larger leakage flow rate is more damaged than the other hydraulic pump.
　従って、このように温度環境が普段と大きく異なっている場合は、２つの油圧ポンプの各漏れ流量を算出する際に２つの油圧ポンプの漏れ流量の偏差の影響を加味することにより、各漏れ流量に対する温度環境の変化による影響を抑えることができより適切な漏れ診断が行えるようになる。 Therefore, when the temperature environment is significantly different from usual, each leak flow rate is calculated by taking into account the influence of the deviation of the leak flow rates of the two hydraulic pumps when calculating each leak flow rate of the two hydraulic pumps. The influence of changes in the temperature environment can be suppressed, and more appropriate leak diagnosis can be performed.
　図７に本実施例における油圧駆動装置２００の概略構成を示し、図８に本実施例における油圧ポンプ２１ａ，２１ｂの漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２の補正演算処理を示す。なお、油圧ポンプ２１ａ，２１ｂの漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２の算出方法は第１の実施例で説明した通りである。 FIG. 7 shows a schematic configuration of the hydraulic drive device 200 in this embodiment, and FIG. 8 shows a correction calculation process for the leakage flow rates Qleak1 and Qleak2 of the hydraulic pumps 21a and 21b in this embodiment. The calculation method of the leakage flow rates Qleak1 and Qleak2 of the hydraulic pumps 21a and 21b is as described in the first embodiment.
　図８に示す例では、漏れ流量Ｑｌｅａｋ１と漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２の偏差（＝Ｑｌｅａｋ１－Ｑｌｅａｋ２）の絶対値との加重平均を補正後の漏れ流量Ｑｌｅａｋ１として算出し、漏れ流量Ｑｌｅａｋ２と漏れ流量Ｑｌｅａｋ２，Ｑｌｅａｋ１の差分（＝Ｑｌｅａｋ２－Ｑｌｅａｋ１）の絶対値との加重平均を油圧ポンプ２１ａの補正後の漏れ流量Ｑｌｅａｋ２として算出する。 In the example shown in FIG. 8, the weighted average of the deviation (= Qleak1-Qleak2) of the leakage flow rate Qleak1 and the leakage flow rate Qleak1 and Qleak2 is calculated as the corrected leakage flow rate Qleak1, and the leakage flow rate Qleak2 and the leakage flow rate Qleak2 The weighted average of the difference (= Qleak2-Qleak1) of Qleak1 with the absolute value is calculated as the corrected leakage flow rate Qleak2 of the hydraulic pump 21a.
　漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２の比重を決定する係数Ｋ１および漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２の偏差の絶対値の比重を決定する係数Ｋ２は、Ｋ１＋Ｋ２＝１の条件を満たし、かつ標準温度ＴＮにおいてＫ１が支配的（例えば０．９）であり、温度が低下するに従って係数Ｋ２が支配的（例えば０．９）になるように設定されている。 The coefficient K1 that determines the specific gravity of the leak flow rates Qleak1 and Qleak2 and the coefficient K2 that determines the specific gravity of the absolute value of the deviations of the leakage flow rates Qleak1 and Qleak2 satisfy the condition of K1 + K2 = 1, and K1 is dominant at the standard temperature TN. (For example, 0.9), and the coefficient K2 is set to become dominant (for example, 0.9) as the temperature decreases.
　本実施例における油圧ショベル１００は、原動機２０によって駆動され、タンク２９から吸い込んだ作動油を吐出する片傾転型可変容量式の第２油圧ポンプ２１ｂと、第２油圧ポンプ２１ｂの吐出油が供給される第２吐出油路２８ｂに接続され、第２油圧ポンプ２１ｂから複数の油圧アクチュエータ１０７～１０９に供給される作動油の流れを制御する第２方向切換弁ユニット２４ｂと、第２油圧ポンプ２１ｂの吐出圧力を検出する第２圧力センサ２７ｂと、作動油の温度を検出する温度センサ３０とを更に備え、コントローラ４０は、第２吐出油路２９ｂとタンク２９との間の連通を遮断し、かつ第２油圧ポンプ２１ｂの傾転を診断用傾転ｑｐｄに保持した状態で、原動機２０の回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから上昇させつつ第２油圧ポンプ２１ｂの吐出圧力を計測し、第２油圧ポンプ２１ｂの吐出圧力が所定の圧力Ｐｓに達したときの原動機２０の回転数Ｎｅｎｇと診断用傾転ｑｐ０とに基づいて第２油圧ポンプ２１ｂの漏れ流量Ｑｌｅａｋ２を算出し、作動油の温度に応じて、第１油圧ポンプ２１ａおよび第２油圧ポンプ２１ｂの各漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２の算出値を補正する。なお、本実施例では、第２油圧ポンプ２１ｂの吐出圧力を計測する際に、原動機２０の回転数Ｎｅｎｇを最小回転数Ｎｅｎｇ＿ｍｉｎから上昇させる制御を行うこととしたが、原動機２０の回転数の制御方法はこれに限定されず、例えば最大回転数Ｎｅｎｇ＿ｍａｘから低下させる制御を行っても良い。 The hydraulic excavator 100 in this embodiment is driven by a prime mover 20 and is supplied with a uni-tilt variable displacement type second hydraulic pump 21b for discharging hydraulic oil sucked from a tank 29 and discharge oil for the second hydraulic pump 21b. A second direction switching valve unit 24b, which is connected to the second discharge oil passage 28b and controls the flow of hydraulic oil supplied from the second hydraulic pump 21b to the plurality of hydraulic actuators 107 to 109, and a second hydraulic pump 21b. A second pressure sensor 27b for detecting the discharge pressure of the hydraulic oil and a temperature sensor 30 for detecting the temperature of the hydraulic oil are further provided, and the controller 40 cuts off the communication between the second discharge oil passage 29b and the tank 29. In addition, while the tilt of the second hydraulic pump 21b is held in the diagnostic tilt qpd, the discharge pressure of the second hydraulic pump 21b is measured while increasing the rotation speed Neng of the prime mover 20 from the minimum rotation speed Neng_min, and the second The leakage flow rate Qleak2 of the second hydraulic pump 21b is calculated based on the rotation speed Neng of the prime mover 20 when the discharge pressure of the hydraulic pump 21b reaches a predetermined pressure Ps and the tilt qp0 for diagnosis, and the temperature of the hydraulic oil is adjusted to Qleak2. Correspondingly, the calculated values of the leakage flow rates Qleak1 and Qleak2 of the first hydraulic pump 21a and the second hydraulic pump 21b are corrected. In this embodiment, when measuring the discharge pressure of the second hydraulic pump 21b, the rotation speed Neng of the prime mover 20 is controlled to be increased from the minimum rotation speed Neng_min, but the rotation speed of the prime mover 20 is controlled. The method is not limited to this, and for example, control may be performed to reduce the maximum rotation speed from Neng_max.
　以上のように構成した本実施例によれば、作動油の温度に応じて油圧ポンプ２１ａ，２１ｂの漏れ流量Ｑｌｅａｋ１，Ｑｌｅａｋ２を補正することにより、温度環境によらず適切な漏れ診断を行うことが可能となる。 According to the present embodiment configured as described above, it is possible to perform an appropriate leak diagnosis regardless of the temperature environment by correcting the leak flow rates Qleak1 and Qleak2 of the hydraulic pumps 21a and 21b according to the temperature of the hydraulic oil. It will be possible.
　以上、本発明の実施例について詳述したが、本発明は、上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は、本発明を分かり易く説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施例の構成に他の実施例の構成の一部を加えることも可能であり、ある実施例の構成の一部を削除し、あるいは、他の実施例の一部と置き換えることも可能である。 Although the examples of the present invention have been described in detail above, the present invention is not limited to the above-mentioned examples, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. It is also possible to add a part of the configuration of another embodiment to the configuration of one embodiment, delete a part of the configuration of one embodiment, or replace it with a part of another embodiment. It is possible.
　１…ケーシング、１Ａ…ケーシング本体、１Ｂ…ヘッドケーシング、１Ｃ…長孔、２…回転軸、３…シリンダブロック、４…シリンダ、５…ピストン、６…コネクティングロッド、６Ａ…球形部、７…ドライブディスク、８…弁板、８Ａ…貫通孔、９…傾転摺動面、１０…センタシャフト、１１…傾転機構、１２…シリンダ室、１２Ａ，１２Ｂ…油通孔、１３Ａ，１３Ｂ…液圧室、１４…サーボピストン、１５…揺動ピン、１５Ａ…球形状先端部、１６…制御部、１７…フィードバックピン、２０…エンジン（原動機）、２１…油圧ポンプ（第１油圧ポンプ）、２１ａ…油圧ポンプ（第１油圧ポンプ）、２１ｂ…油圧ポンプ（第２油圧ポンプ）、２２，２２ａ，２２ｂ…傾転制御装置、２３…電磁比例弁、２４…方向切換弁ユニット（第１方向切換弁ユニット）、２４ａ…方向切換弁ユニット（第１方向切換弁ユニット）、２４ｂ…方向切換弁ユニット（第２方向切換弁ユニット）、２５，２５ａ，２５ｂ…ブリードオフ閉鎖バルブ、２６…リリーフ弁、２７…圧力センサ（第１圧力センサ）、２７ａ…圧力センサ（第１圧力センサ）、２７ｂ…圧力センサ（第２圧力センサ）、２８…ポンプ吐出油路（第１吐出油路）、２８ａ…ポンプ吐出油路（第１吐出油路）、２８ｂ…ポンプ吐出油路（第２吐出油路）、２９…タンク、３０…温度センサ、４０…コントローラ、４１…測定制御部、４２…バルブ制御部、４３…エンジン回転数制御部、４４…ポンプ傾転制御部、４５…ポンプ流量算出部、４６…ポンプ圧力計測部、４７…漏れ流量算出部、５０…モニタ、６０ａ，６０ｂ…バイパスライン、１００…油圧ショベル（建設機械）、１０１…走行体、１０２…旋回体、１０３…作業装置、１０４…ブーム、１０５…アーム、１０６…バケット、１０７…ブームシリンダ（油圧アクチュエータ）、１０８…アームシリンダ（油圧アクチュエータ）、１０９…バケットシリンダ（油圧アクチュエータ）、１１０…運転室、１２０Ｌ，１２０Ｒ…走行モータ（油圧アクチュエータ）、１２１…旋回モータ（油圧アクチュエータ）、２００…油圧駆動装置。 1 ... Casing, 1A ... Casing body, 1B ... Head casing, 1C ... Long hole, 2 ... Rotating shaft, 3 ... Cylinder block, 4 ... Cylinder, 5 ... Piston, 6 ... Connecting rod, 6A ... Spherical part, 7 ... Drive Disc, 8 ... Valve plate, 8A ... Through hole, 9 ... Tilt sliding surface, 10 ... Center shaft, 11 ... Tilt mechanism, 12 ... Cylinder chamber, 12A, 12B ... Oil passage hole, 13A, 13B ... Hydraulic pressure Chamber, 14 ... Servo piston, 15 ... Swing pin, 15A ... Spherical tip, 16 ... Control, 17 ... Feedback pin, 20 ... Engine (motor), 21 ... Hydraulic pump (first hydraulic pump), 21a ... Hydraulic pump (first hydraulic pump), 21b ... Hydraulic pump (second hydraulic pump), 22, 22a, 22b ... Tilt control device, 23 ... Electromagnetic proportional valve, 24 ... Direction switching valve unit (first direction switching valve unit) ), 24a ... Direction switching valve unit (first direction switching valve unit), 24b ... Direction switching valve unit (second direction switching valve unit), 25, 25a, 25b ... Bleed-off closing valve, 26 ... Relief valve, 27 ... Pressure sensor (first pressure sensor), 27a ... pressure sensor (first pressure sensor), 27b ... pressure sensor (second pressure sensor), 28 ... pump discharge oil passage (first discharge oil passage), 28a ... pump discharge oil Road (first discharge oil passage), 28b ... Pump discharge oil passage (second discharge oil passage), 29 ... Tank, 30 ... Temperature sensor, 40 ... Controller, 41 ... Measurement control unit, 42 ... Valve control unit, 43 ... Engine speed control unit, 44 ... Pump tilt control unit, 45 ... Pump flow rate calculation unit, 46 ... Pump pressure measurement unit, 47 ... Leakage flow rate calculation unit, 50 ... Monitor, 60a, 60b ... Bypass line, 100 ... Hydraulic excavator (Construction machinery), 101 ... Running body, 102 ... Swing body, 103 ... Working device, 104 ... Boom, 105 ... Arm, 106 ... Bucket, 107 ... Boom cylinder (Flood control actuator), 108 ... Arm cylinder (Flood control actuator), 109 ... Bucket cylinder (flood control actuator), 110 ... Driver's cab, 120L, 120R ... Travel motor (flood control actuator), 121 ... Swirling motor (flood control actuator), 200 ... Hydraulic drive device.

Claims (3)

  1. 　原動機と、
    　作動油を貯留するタンクと、
    　前記原動機によって駆動され、前記タンクから吸い込んだ作動油を吐出する片傾転型可変容量式の第１油圧ポンプと、
    　複数の油圧アクチュエータと、
    　前記第１油圧ポンプの吐出油が供給される第１吐出油路に接続され、前記第１油圧ポンプから前記複数の油圧アクチュエータに供給される作動油の流れを制御する第１方向切換弁ユニットと、
    　前記原動機の回転数および前記第１油圧ポンプの傾転を制御するコントローラとを備えた建設機械において、
    　前記第１油圧ポンプの吐出圧力を検出する第１圧力センサを備え、
    　前記コントローラは、
    　前記第１吐出油路と前記タンクとの連通を遮断し、かつ前記第１油圧ポンプの傾転をスタンバイ傾転よりも小さく設定された診断用傾転に保持した状態で、前記原動機の回転数を変化させつつ前記第１油圧ポンプの吐出圧力を計測し、
    　前記第１油圧ポンプの吐出圧力が所定の圧力に達したときの前記原動機の回転数と前記診断用傾転とに基づいて前記第１油圧ポンプの漏れ流量を算出する
    　ことを特徴とした建設機械。     The prime mover and
    A tank for storing hydraulic oil and
    A uni-tilt variable displacement type first hydraulic pump driven by the prime mover and discharging the hydraulic oil sucked from the tank, and
    With multiple hydraulic actuators,
    A first-direction switching valve unit that is connected to a first discharge oil passage to which the discharge oil of the first hydraulic pump is supplied and controls the flow of hydraulic oil supplied from the first hydraulic pump to the plurality of hydraulic actuators. ,
    In a construction machine provided with a controller for controlling the rotation speed of the prime mover and the tilt of the first hydraulic pump.
    A first pressure sensor for detecting the discharge pressure of the first hydraulic pump is provided.
    The controller
    The rotation speed of the prime mover in a state where the communication between the first discharge oil passage and the tank is cut off and the tilt of the first hydraulic pump is held at a diagnostic tilt set smaller than the standby tilt. Measure the discharge pressure of the first hydraulic pump while changing
    A construction machine characterized in that the leakage flow rate of the first hydraulic pump is calculated based on the rotation speed of the prime mover and the tilt for diagnosis when the discharge pressure of the first hydraulic pump reaches a predetermined pressure. ..
  2. 　請求項１に記載の建設機械において、
    　前記第１方向切換弁ユニットと前記タンクとを接続するバイパスラインに設けられ、前記コントローラからの制御信号に応じて開閉するブリードオフ閉鎖バルブを更に備え、
    　前記コントローラは、前記ブリードオフ閉鎖バルブを閉じることにより前記第１吐出油路と前記タンクとの連通を遮断する
    　ことを特徴とする建設機械。     In the construction machine according to claim 1,
    A bleed-off closing valve provided on the bypass line connecting the first-direction switching valve unit and the tank and which opens and closes in response to a control signal from the controller is further provided.
    The controller is a construction machine characterized in that the communication between the first discharge oil passage and the tank is cut off by closing the bleed-off closing valve.
  3. 　請求項１に記載の建設機械において、
    　前記原動機によって駆動され、前記タンクから吸い込んだ作動油を吐出する片傾転型可変容量式の第２油圧ポンプと、
    　前記第２油圧ポンプの吐出油が供給される第２吐出油路に接続され、前記第２油圧ポンプから前記複数の油圧アクチュエータに供給される作動油の流れを制御する第２方向切換弁ユニットと、
    　前記第２油圧ポンプの吐出圧力を検出する第２圧力センサと、
    　前記作動油の温度を検出する温度センサとを更に備え、
    　前記コントローラは、
    　前記第２吐出油路と前記タンクとの間の連通を遮断し、かつ前記第２油圧ポンプの傾転を前記診断用傾転に保持した状態で、前記原動機の回転数を変化させつつ前記第２油圧ポンプの吐出圧力を計測し、
    　前記第２油圧ポンプの吐出圧力が所定の圧力に達したときの前記原動機の回転数と前記診断用傾転とに基づいて前記第２油圧ポンプの漏れ流量を算出し、
    　前記作動油の温度に応じて、前記第１油圧ポンプおよび前記第２油圧ポンプの各漏れ流量の算出値を補正する
    　ことを特徴とした建設機械。     In the construction machine according to claim 1,
    A uni-tilt variable displacement type second hydraulic pump driven by the prime mover and discharging the hydraulic oil sucked from the tank, and
    A second direction switching valve unit that is connected to a second discharge oil passage to which the discharge oil of the second hydraulic pump is supplied and controls the flow of hydraulic oil supplied from the second hydraulic pump to the plurality of hydraulic actuators. ,
    A second pressure sensor that detects the discharge pressure of the second hydraulic pump, and
    Further equipped with a temperature sensor for detecting the temperature of the hydraulic oil,
    The controller
    The first, while changing the rotation speed of the prime mover, while blocking the communication between the second discharge oil passage and the tank and holding the tilt of the second hydraulic pump at the tilt for diagnosis. 2 Measure the discharge pressure of the hydraulic pump and
    The leakage flow rate of the second hydraulic pump is calculated based on the rotation speed of the prime mover and the tilt for diagnosis when the discharge pressure of the second hydraulic pump reaches a predetermined pressure.
    A construction machine characterized in that the calculated values of the leakage flow rates of the first hydraulic pump and the second hydraulic pump are corrected according to the temperature of the hydraulic oil.
PCT/JP2020/037478 2019-10-10 2020-10-01 Construction machine WO2021070736A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019187103A JP7324114B2 (en) 2019-10-10 2019-10-10 construction machinery
JP2019-187103 2019-10-10

Publications (1)

Publication Number Publication Date
WO2021070736A1 true WO2021070736A1 (en) 2021-04-15

Family

ID=75436815

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/037478 WO2021070736A1 (en) 2019-10-10 2020-10-01 Construction machine

Country Status (2)

Country Link
JP (1) JP7324114B2 (en)
WO (1) WO2021070736A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10169604A (en) * 1996-12-10 1998-06-23 Hitachi Constr Mach Co Ltd Hydraulic circuit device for hydraulic work machine
JP2000046015A (en) * 1998-07-28 2000-02-15 Yutani Heavy Ind Ltd Self-diagnostic device of hydraulic circuit
JP2013072454A (en) * 2011-09-27 2013-04-22 Daikin Industries Ltd Hydraulic unit
JP2019049204A (en) * 2017-09-07 2019-03-28 日立建機株式会社 Hydraulic drive unit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10169604A (en) * 1996-12-10 1998-06-23 Hitachi Constr Mach Co Ltd Hydraulic circuit device for hydraulic work machine
JP2000046015A (en) * 1998-07-28 2000-02-15 Yutani Heavy Ind Ltd Self-diagnostic device of hydraulic circuit
JP2013072454A (en) * 2011-09-27 2013-04-22 Daikin Industries Ltd Hydraulic unit
JP2019049204A (en) * 2017-09-07 2019-03-28 日立建機株式会社 Hydraulic drive unit

Also Published As

Publication number Publication date
JP7324114B2 (en) 2023-08-09
JP2021063524A (en) 2021-04-22

Similar Documents

Publication Publication Date Title
WO2021124658A1 (en) Construction machine
JP5984165B2 (en) Hydraulic control device for work machine
JP6934454B2 (en) Construction machinery
JP6712578B2 (en) Hydraulic drive
US11781288B2 (en) Shovel
WO2015025818A1 (en) Hydraulic control device for work machine
JP6891079B2 (en) Hydraulic drive system for construction machinery
JP2015197185A (en) Hydraulic control device or work machine
JP6605316B2 (en) Drive device for work machine
WO2021070736A1 (en) Construction machine
WO2022102391A1 (en) Construction machine
WO2019159550A1 (en) Slewing-type work machine
US10883245B2 (en) Hydraulic driving apparatus of work machine
JP3629382B2 (en) Construction machine control equipment
JP2020133856A (en) Control device and construction machine
JP3705886B2 (en) Hydraulic drive control device
JP6901441B2 (en) Hydraulic drive
WO2021039926A1 (en) Construction machine
JP2021095728A (en) Construction machine
JP2022170467A (en) Work machine
JP2023150467A (en) working machine
JPH04203502A (en) Automatic engine speed regulator in load sensing system
JP2021021199A (en) Shovel

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20873665

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20873665

Country of ref document: EP

Kind code of ref document: A1