TWI809223B

TWI809223B - lathe

Info

Publication number: TWI809223B
Application number: TW108142268A
Authority: TW
Inventors: 賀来則夫
Original assignee: 日商星精密股份有限公司
Priority date: 2018-11-27
Filing date: 2019-11-21
Publication date: 2023-07-21
Also published as: JP7323759B2; JP2020082276A; TW202023714A; WO2020110573A1

Abstract

本發明提供一種可提高製品之尺寸精度之車床。車床1具備：第一主軸台(11)、第二主軸台(21)、使該第二主軸台(21)向第二主軸(22)之中心線方向移動之伺服裝置(MZ2)、以及控制固持部13、23之開閉動作及經由伺服裝置(MZ2)之第二主軸台(21)之移動的控制部U1。控制部U1於打開第二固持部23且將伺服裝置(MZ2)限制於低於最大轉矩之轉矩之狀態下使第二主軸台(21)向第一主軸台(11)移動，對伺服裝置(MZ2)賦予特定之轉矩變動並檢測第二主軸之中心線方向上之第二主軸台(21)之位置之變化(ΔZi)，基於在第二固持部23固持工件W0之範圍內所檢測到之位置之變化(ΔZi)，判別第二固持部23與工件W0之間有無異物800。The invention provides a lathe capable of improving the dimensional accuracy of products. The lathe 1 is provided with: a first headstock (11), a second headstock (21), a servo device (MZ2) for moving the second headstock (21) toward the center line of the second spindle (22), and a control The control unit U1 for the opening and closing action of the holding parts 13 and 23 and the movement of the second headstock (21) via the servo device (MZ2). The control part U1 moves the second headstock (21) to the first headstock (11) under the condition that the second holding part 23 is opened and the servo device (MZ2) is limited to a torque lower than the maximum torque. The device (MZ2) imparts a specific torque variation and detects the change (ΔZi) of the position of the second headstock (21) in the direction of the center line of the second spindle, based on the position within the range where the second holding part 23 holds the workpiece W0 The detected position change (ΔZi) determines whether there is a foreign object 800 between the second holding portion 23 and the workpiece W0.

Description

車床lathe

本發明係關於一種使相互對向之兩個主軸固持工件之車床。The present invention relates to a kind of lathe with two spindles facing each other holding workpieces.

作為車床，已知有對固持於正面主軸之工件進行正面加工且將正面加工後之工件交付至背面主軸進行背面加工的NC(數值控制)車床。正面主軸與背面主軸具有筒夾等固持工件之固持部。NC車床進行如下處理：使背面主軸向固持於正面主軸之固持部之正面加工後之工件移動而使背面主軸之固持部固持該工件。此處，於碎屑等異物進入正面加工後之工件與背面主軸之固持部之間之情形時，有產生工件之不良或固持部之破損等問題之可能性。例如，若固持工件之背面主軸之主軸中心線方向上之位置發生偏移，則有產生工件之全長不良之情況。若工件傾斜地固持於背面主軸之固持部，則有產生工件之形狀不良或固持部之破損之情況。因此，進行於正面加工後之工件與背面主軸之固持部之間是否存在異物之判別。As a lathe, there is known an NC (Numerical Control) lathe that processes the front side of a workpiece held on a front spindle, and transfers the front-machined workpiece to a rear spindle for rear machining. The front spindle and the rear spindle have holding parts such as collets for holding workpieces. The NC lathe performs a process in which the back spindle is moved to the front-processed workpiece held by the holding portion of the front spindle, and the workpiece is held by the holding portion of the back spindle. Here, when foreign matter such as chips enters between the workpiece processed on the front side and the holding portion of the back spindle, problems such as defects in the workpiece or damage to the holding portion may occur. For example, if the position of the back spindle holding the workpiece in the direction of the spindle center line is shifted, the overall length of the workpiece may be defective. If the workpiece is held obliquely on the holding portion of the back spindle, the shape of the workpiece may be defective or the holding portion may be damaged. Therefore, it is judged whether there is a foreign object between the workpiece after front processing and the holding part of the back spindle.

於專利文獻1中揭示有一種確認第二主軸頭之夾頭正常地固持有在第一主軸頭經加工之工件的車床之工件更換方法。該車床將控制第二主軸頭之進給之伺服馬達設為轉矩限制狀態，使第二主軸頭向第一主軸頭之方向進給，於第二主軸頭之移動完成之時間點，調查經編程之第二主軸頭之位置與實際之位置的差即誤差量，藉由使誤差量為特定值以下，而確認第二主軸頭之夾頭正常地固持工件。 [先前技術文獻] [專利文獻]Patent Document 1 discloses a workpiece replacement method for a lathe for confirming that the chuck of the second spindle head is normally holding the workpiece processed on the first spindle head. In this lathe, the servo motor that controls the feed of the second spindle head is set to a torque-limited state, so that the second spindle head is fed in the direction of the first spindle head. At the time when the movement of the second spindle head is completed, the investigation process The difference between the programmed position of the second spindle head and the actual position is the error amount. By keeping the error amount below a certain value, it is confirmed that the chuck of the second spindle head is normally holding the workpiece. [Prior technical literature] [Patent literature]

[專利文獻1]日本專利第2702575號公報[Patent Document 1] Japanese Patent No. 2702575

[發明所欲解決之問題][Problem to be solved by the invention]

但是，若第二主軸頭等受衝擊等干擾因素影響，則有伺服馬達之輸出轉矩急遽地上升而錯誤地偵測到第二主軸頭之移動已完成。於是，即便於工件與第二主軸頭之間無異物，第二主軸頭固持工件之位置亦產生誤差，相應地，製品之尺寸精度降低。再者，如上所述之問題存在於各種車床。However, if the second spindle head is affected by disturbance factors such as impact, the output torque of the servo motor rises sharply and it is erroneously detected that the movement of the second spindle head has been completed. Therefore, even if there is no foreign matter between the workpiece and the second spindle head, an error occurs in the position of the second spindle head holding the workpiece, and correspondingly, the dimensional accuracy of the product is reduced. Furthermore, the above-mentioned problems exist in various lathes.

本發明揭示一種可提高製品之尺寸精度之車床。 [解決問題之技術手段]The invention discloses a lathe capable of improving the dimensional accuracy of products. [Technical means to solve problems]

本發明之車床具有如下態樣，其具備：第一主軸台，其設置有具有固持工件之第一固持部之第一主軸；第二主軸台，其設置有與上述第一主軸對向且具有固持上述工件之第二固持部之第二主軸；伺服裝置，其使該第二主軸台向上述第二主軸之中心線方向移動；及控制部，其控制上述第一固持部及上述第二固持部之開閉動作、以及經由上述伺服裝置進行之上述第二主軸台之移動；上述控制部於打開上述第二固持部且將上述伺服裝置限制於低於最大轉矩之轉矩之狀態下，使上述第二主軸台向上述第一主軸台移動，對上述伺服裝置賦予特定之轉矩變動並檢測上述中心線方向上之上述第二主軸台之位置之變化，基於在上述第二固持部固持上述工件之範圍內所檢測到之位置之變化，判別上述第二固持部與上述工件之間有無異物。 [發明之效果]The lathe of the present invention has the following aspect, which has: a first headstock, which is provided with a first spindle having a first holding part for holding a workpiece; a second headstock, which is provided with a the second main shaft of the second holding part holding the workpiece; the servo device, which moves the second headstock to the centerline direction of the second main shaft; and the control part, which controls the first holding part and the second holding part The opening and closing action of the above-mentioned servo device and the movement of the above-mentioned second headstock through the above-mentioned servo device; The above-mentioned control part is in the state where the above-mentioned second holding part is opened and the above-mentioned servo device is limited to a torque lower than the maximum torque. The second headstock moves toward the first headstock, imparts a specific torque variation to the servo device and detects a change in the position of the second headstock in the direction of the center line, based on holding the The detected position change within the range of the workpiece determines whether there is a foreign object between the second holding portion and the workpiece. [Effect of Invention]

根據本發明，可提供一種提高製品之尺寸精度之車床。According to the present invention, it is possible to provide a lathe with improved dimensional accuracy of products.

以下，對本發明之實施形態進行說明。當然，以下之實施形態僅為例示本發明者，實施形態中所揭示之所有特徵對於發明之解決手段而言未必為必需。Embodiments of the present invention will be described below. Of course, the following embodiments are merely examples of the present invention, and all the features disclosed in the embodiments are not necessarily essential to the solution means of the invention.

(1)本發明中所包含之技術之概要：首先，參照圖1～9所示之例對本發明中所包含之技術之概要進行說明。再者，本案之圖係模式性地表示示例之圖，該等圖所示之各方向之放大率有時不同，各圖有時不匹配。當然，本技術之各要素並不限定於符號所示之具體例。又，本案中，數值範圍「Min～Max」意指最小值Min以上且最大值Max以下。(1) Outline of technology included in the present invention: First, an overview of technology included in the present invention will be described with reference to examples shown in FIGS. 1 to 9 . Furthermore, the diagrams in this application are diagrams schematically showing examples, and the magnification ratios in each direction shown in these diagrams may be different, and the diagrams may not match each other. Of course, each element of this technology is not limited to the specific example shown by a code|symbol. Also, in this case, the numerical range "Min~Max" means above the minimum value Min and below the maximum value Max.

[態樣1] 本技術之一態樣之車床1具備第一主軸台(例如正面主軸台11)、第二主軸台(例如背面主軸台21)、伺服裝置(例如Z2軸馬達MZ2)、及控制部U1。上述第一主軸台(11)設置有具有固持工件W0之第一固持部13之第一主軸(例如正面主軸12)。上述第二主軸台(21)設置有與上述第一主軸(12)對向且具有固持上述工件W0之第二固持部23之第二主軸(例如背面主軸22)。上述伺服裝置(MZ2)使上述第二主軸台(21)向上述第二主軸(22)之中心線方向(例如Z軸方向)移動。上述控制部U1控制上述第一固持部13及上述第二固持部23之開閉動作、以及經由上述伺服裝置(MZ2)之上述第二主軸台(21)之移動。上述控制部U1於打開上述第二固持部23且將上述伺服裝置(MZ2)限制於低於最大轉矩之轉矩之狀態下使上述第二主軸台(21)向上述第一主軸台(11)移動，對上述伺服裝置(MZ2)賦予特定之轉矩變動並檢測上述中心線方向上之上述第二主軸台(21)之位置之變化(例如變動幅度ΔZi)，基於在上述第二固持部23固持上述工件W0之範圍內所檢測到之位置之變化(ΔZi)，判別上述第二固持部23與上述工件W0之間有無異物800。[Aspect 1] The lathe 1 of one aspect of this technology has a first headstock (such as the front headstock 11), a second headstock (such as the back headstock 21), a servo device (such as a Z2-axis motor MZ2), and Control unit U1. The above-mentioned first headstock (11) is provided with a first spindle (eg front spindle 12) having a first holding portion 13 for holding the workpiece W0. The second headstock (21) is provided with a second spindle (eg back spindle 22) facing the first spindle (12) and having a second holding portion 23 for holding the workpiece W0. The servo device (MZ2) moves the second headstock (21) in the direction of the center line of the second spindle (22) (for example, the Z-axis direction). The control unit U1 controls the opening and closing operations of the first holding unit 13 and the second holding unit 23, and the movement of the second headstock (21) via the servo device (MZ2). The control unit U1 moves the second headstock (21) toward the first headstock (11) in a state where the second holding part 23 is opened and the servo device (MZ2) is limited to a torque lower than the maximum torque. ) movement, giving a specific torque variation to the servo device (MZ2) and detecting the change in the position of the second headstock (21) in the direction of the center line (for example, the variation range ΔZi), based on the above-mentioned second holding part 23 to determine whether there is a foreign object 800 between the second holding part 23 and the workpiece W0 according to the detected position change (ΔZi) within the range of holding the workpiece W0.

於上述態樣1中，基於由伺服裝置(MZ2)之特定之轉矩變動所引起之第二主軸台(21)之位置之變化(ΔZi)，判別將固持於第一主軸(12)之固持部13之工件W0利用第二主軸(22)之固持部23固持時第二主軸(22)之固持部23與工件W0之間有無異物800。藉此，可精度良好地判別第二主軸(22)之固持部23與工件W0之間有無異物800。因此，本態樣可提供一種提高製品之尺寸精度之車床。In the above-mentioned aspect 1, based on the change (ΔZi) of the position of the second headstock (21) caused by the specific torque variation of the servo device (MZ2), it is judged that the holding of the first main shaft (12) will be held When the workpiece W0 of part 13 is held by the holding part 23 of the second spindle (22), whether there is a foreign object 800 between the holding part 23 of the second spindle (22) and the workpiece W0. Thereby, it is possible to accurately determine whether there is a foreign object 800 between the holding portion 23 of the second spindle (22) and the workpiece W0. Therefore, this aspect can provide a lathe with improved dimensional accuracy of products.

此處，上述控制部開始對上述伺服裝置賦予特定之轉矩變動之時點可為成為上述第二固持部固持上述工件之範圍之後，亦可為成為上述第二固持部固持上述工件之範圍之前。於後者之情形時，上述控制部開始檢測上述中心線方向上之上述第二主軸台之位置之變化之時點可為成為上述第二固持部固持上述工件之範圍之後，亦可為成為上述第二固持部固持上述工件之範圍之前。Here, the timing at which the control unit starts to apply a specific torque variation to the servo device may be after the second holding unit holds the workpiece or before the second holding unit holds the workpiece. In the latter case, the timing at which the control unit starts to detect the change in the position of the second headstock in the direction of the center line may be after the range in which the second holding unit holds the workpiece, or it may be the second headstock position. The holding part holds the front of the range of the workpiece.

[態樣2] 又，本車床1亦可進而具備清掃裝置40，該清掃裝置40可對固持於上述第一固持部13之上述工件W0與自該工件W0離開之上述第二固持部23之至少一者進行清掃。上述控制部U1亦可為，若於判別上述第二固持部23與上述工件W0之間有無異物800之異物判別處理(例如圖6所示之步驟S102～S108)中判別為上述第二固持部23與上述工件W0之間存在異物800，則使上述第二主軸台(21)向遠離上述第一主軸台(11)之方向移動而使上述清掃裝置40進行清掃(參照例如圖7)，並再次進行上述異物判別處理。本態樣係若判別為第二主軸(22)之固持部23與工件W0之間存在異物800則對第二主軸(22)之固持部23及工件W0之至少一者進行清掃，因此若藉由清掃而去除異物800，則於下一異物判別處理中判別為第二主軸(22)之固持部23與工件W0之間不存在異物800。因此，本態樣可提供一種對工件連續地進行加工之適宜之車床。[Aspect 2] In addition, this lathe 1 may further be equipped with a cleaning device 40, which can clean the gap between the above-mentioned workpiece W0 held by the above-mentioned first holding part 13 and the above-mentioned second holding part 23 separated from the work W0. At least one of them cleans. The above-mentioned control unit U1 may also be, if it is determined that the second holding unit is the second holding unit in the foreign matter discrimination process (such as steps S102-S108 shown in FIG. If there is a foreign object 800 between 23 and the workpiece W0, the second headstock (21) is moved away from the first headstock (11) to clean the cleaning device 40 (see, for example, FIG. 7 ), and The above-mentioned foreign matter discrimination processing is performed again. In this aspect, if it is determined that there is a foreign object 800 between the holding portion 23 of the second spindle (22) and the workpiece W0, at least one of the holding portion 23 of the second spindle (22) and the workpiece W0 will be cleaned. If the foreign matter 800 is removed by cleaning, it is judged that there is no foreign matter 800 between the holding portion 23 of the second spindle ( 22 ) and the workpiece W0 in the next foreign matter identification process. Therefore, this aspect can provide a suitable lathe for continuously processing workpieces.

(2)車床之構成之具體例：圖1模式性地例示正面主軸12移動之主軸移動型NC(數值控制)車床1之構成作為車床之例。圖1僅例示為了說明本技術而簡化之一例，並非限定本技術。再者，各部之位置關係之說明僅為例示。因此，將左右方向變更為上下方向或前後方向、或將上下方向變更為左右方向或前後方向、或將前後方向變更為左右方向或上下方向、或將旋轉方向變更為相反方向等亦包含於本技術。又，方向或位置等相同並不限定於嚴格之一致，包含因誤差而偏離嚴格之一致之情況。(2) A specific example of the configuration of the lathe: FIG. 1 schematically illustrates the configuration of a spindle-moving type NC (numerical control) lathe 1 in which the front spindle 12 moves as an example of the lathe. FIG. 1 only illustrates an example simplified for describing the present technology, and does not limit the present technology. In addition, the description of the positional relationship of each part is an example only. Therefore, changing the left-right direction to the up-down direction or the front-rear direction, or changing the up-down direction to the left-right direction or the front-rear direction, or changing the front-rear direction to the left-right direction or the up-down direction, or changing the rotation direction to the opposite direction are also included in this document. technology. In addition, the same direction, position, etc. are not limited to strict coincidence, but include deviations from strict coincidence due to errors.

圖1所示之車床1具備：NC裝置70、設置於經固定之基座10之正面主軸台11、設置於經固定之基座20之背面主軸台21、設置於經固定之基座30之刀架31、清掃裝置40等。NC裝置70控制上述各部11、21、31、40等之動作。The lathe 1 shown in Fig. 1 has: NC device 70, the front headstock 11 that is arranged on the fixed base 10, the back headstock 21 that is arranged on the fixed base 20, the headstock that is arranged on the fixed base 30. Knife rest 31, cleaning device 40 etc. The NC device 70 controls the operations of the above-mentioned respective units 11, 21, 31, 40 and the like.

正面主軸台11設為可向沿主軸中心線AX1之Z軸方向移動。NC裝置70經由圖2所例示之Z1軸馬達MZ1等驅動部而控制正面主軸台11於Z軸方向上之位置。設置於正面主軸台11之正面主軸12具有筒夾等第一固持部13，利用第一固持部13將向Z軸方向***之圓柱狀(棒狀)之工件W1可釋放地固持。NC裝置70經由旋轉馬達15等驅動部而使正面主軸12以沿工件W1之長度方向之主軸中心線AX1為中心旋轉。藉此，正面主軸12使工件W1以主軸中心線AX1為中心旋轉。The front headstock 11 is configured to be movable in the Z-axis direction along the spindle center line AX1. The NC device 70 controls the position of the front headstock 11 in the Z-axis direction through a driving unit such as the Z1-axis motor MZ1 illustrated in FIG. 2 . The front spindle 12 provided on the front headstock 11 has a first holding portion 13 such as a collet, and the cylindrical (rod-shaped) workpiece W1 inserted in the Z-axis direction is releasably held by the first holding portion 13 . The NC device 70 rotates the front spindle 12 about the spindle centerline AX1 along the longitudinal direction of the workpiece W1 via a drive unit such as the rotary motor 15 . Thereby, the front spindle 12 rotates the workpiece W1 about the spindle center line AX1.

如圖1中兩點鏈線所示，亦可於正面主軸12之前方配置有導引軸套18。該情形時之導引軸套18配置於正面主軸12之前方，將貫通正面主軸12之長條狀工件W1可向Z軸方向滑動地支持，與正面主軸12同步地以主軸中心線AX1為中心旋轉驅動。As shown by the chain line of two dots in FIG. 1 , a guide bushing 18 may also be arranged in front of the front main shaft 12 . In this case, the guide bush 18 is arranged in front of the front main shaft 12 to support the long workpiece W1 penetrating the front main shaft 12 so as to slide in the Z-axis direction, and is centered on the main shaft center line AX1 synchronously with the front main shaft 12. Rotary drive.

背面主軸台21設為可向沿主軸中心線AX2之Z軸方向、及與該Z軸方向正交(交叉)之Y軸方向移動。NC裝置70經由圖2所例示之Z2軸馬達MZ2或Y2軸馬達MY2等驅動部控制背面主軸台21於Z軸方向及Y軸方向上之位置。設置於背面主軸台21之背面主軸22具有筒夾等第二固持部23，利用第二固持部23將於主軸中心線AX1、AX2彼此對準之狀態下向Z軸方向***之正面加工後之工件W2可釋放地固持。NC裝置70經由旋轉馬達25等驅動部以主軸中心線AX2為中心使背面主軸22旋轉。藉此，背面主軸22以主軸中心線AX2為中心使工件W2旋轉。背面主軸22就與正面主軸對向之含義而言有時稱為對向主軸。再者，將正面加工前之工件W1與正面加工後之工件W2統稱為工件W0，將自正面主軸12之固持部13交接至背面主軸22之工件稱為工件W0。The back headstock 21 is movable in the Z-axis direction along the spindle center line AX2 and in the Y-axis direction perpendicular (intersecting) to the Z-axis direction. The NC device 70 controls the positions of the back headstock 21 in the Z-axis direction and the Y-axis direction through a driving unit such as the Z2-axis motor MZ2 or the Y2-axis motor MY2 illustrated in FIG. 2 . The back spindle 22 installed on the back headstock 21 has a second holding part 23 such as a collet, and the front surface is processed by inserting the spindle centerlines AX1 and AX2 in the Z-axis direction with the second holding part 23 aligned with each other. The workpiece W2 is releasably held. The NC device 70 rotates the back spindle 22 about the spindle center line AX2 via a driving unit such as the rotary motor 25 . Thereby, the back spindle 22 rotates the workpiece W2 around the spindle center line AX2. The rear main axis 22 is sometimes referred to as an opposing main axis in the sense that it is opposed to the front main axis. Furthermore, the workpiece W1 before front machining and the workpiece W2 after front machining are collectively called workpiece W0, and the workpiece handed over from the holding part 13 of the front spindle 12 to the back spindle 22 is called workpiece W0.

刀架31安裝有用以對工件W0進行加工之複數個工具T0，且設為可向X軸方向及Z軸方向移動。此處，X軸方向係與Z軸方向及Y軸方向正交(交叉)之方向。NC裝置70經由圖2所例示之X3軸馬達MX3或Z3軸馬達MZ3等驅動部控制刀架31於X軸方向及Z軸方向上之位置。複數個工具T0包含用以對固持於兩主軸12、22之固持部13、23之工件W0進行切割之切割工具T1。刀架可使用轉塔刀架、梳狀刀架等。亦可於車床設置有複數種刀架。又，各部11、21、31等之移動方向並不限定於圖1所示之方向。The tool post 31 is provided with a plurality of tools T0 for processing the workpiece W0, and is movable in the X-axis direction and the Z-axis direction. Here, the X-axis direction is a direction perpendicular (intersecting) to the Z-axis direction and the Y-axis direction. The NC device 70 controls the positions of the tool post 31 in the X-axis direction and the Z-axis direction through a driving unit such as the X3-axis motor MX3 or the Z3-axis motor MZ3 illustrated in FIG. 2 . The plurality of tools T0 includes a cutting tool T1 for cutting the workpiece W0 held on the holding portions 13 , 23 of the two spindles 12 , 22 . The tool holder can use a turret tool holder, a comb tool holder, etc. Multiple types of tool holders may also be provided on the lathe. In addition, the moving direction of each part 11, 21, 31 etc. is not limited to the direction shown in FIG.

清掃裝置40具有：噴嘴41，其用以向固持於正面主軸12之固持部13之工件W0之前端噴出流體；及噴嘴42，其用以向自工件W0離開之背面主軸22之固持部23噴出流體。流體可為空氣(氣體)，亦可為冷卻劑(液體)。清掃裝置40依照NC裝置70之控制自噴嘴41、42噴出流體或停止自噴嘴41、42噴出流體。於噴嘴41、42噴出作為流體之空氣之情形時，於空氣可被吹送至固持於固持部13之工件W0之前端之位置配置噴嘴41，於空氣可被吹送至位於Z軸方向上之特定位置的背面主軸22之固持部23之位置配置噴嘴42。於噴嘴41、42噴出作為流體之冷卻劑之情形時，於冷卻劑可被澆淋至固持於固持部13之工件W0之前端之位置配置噴嘴41，於冷卻劑可被澆淋至位於Z軸方向上之特定位置的背面主軸22之固持部23之位置配置噴嘴42。The cleaning device 40 has: a nozzle 41 for spraying fluid to the front end of the workpiece W0 held on the holding portion 13 of the front spindle 12; and a nozzle 42 for spraying fluid to the holding portion 23 of the back spindle 22 separated from the workpiece W0 fluid. The fluid can be air (gas) or coolant (liquid). The cleaning device 40 ejects the fluid from the nozzles 41 and 42 or stops ejecting the fluid from the nozzles 41 and 42 according to the control of the NC device 70 . When the nozzles 41 and 42 eject air as a fluid, the nozzle 41 is arranged at a position where the air can be blown to the front end of the workpiece W0 held in the holding part 13, and the air can be blown to a specific position in the Z-axis direction. The nozzle 42 is arranged at the position of the holding portion 23 of the back spindle 22 . In the case where the nozzles 41 and 42 spray coolant as a fluid, the nozzle 41 is arranged at a position where the coolant can be poured to the front end of the workpiece W0 held in the holding part 13, and the coolant can be poured to the position located on the Z axis. The nozzle 42 is arranged at the position of the holding portion 23 of the back spindle 22 at a specific position in the direction.

圖2模式性地例示NC車床1之電路之構成。於圖2所示之車床1中，於NC裝置70連接有操作面板80、Z1軸馬達MZ1、Y2軸馬達MY2、Z2軸馬達MZ2、X3軸馬達MX3、Z3軸馬達MZ3、使正面主軸12旋轉驅動之旋轉馬達15、使背面主軸22旋轉驅動之旋轉馬達25、使正面主軸12之固持部13開閉之致動器14、使背面主軸22之固持部23開閉之致動器24、清掃裝置40等。NC裝置70具有CPU(Central Processing Unit，中央處理單元)71、作為半導體記憶體之ROM(Read Only Memory，唯讀記憶體)72、作為半導體記憶體之RAM(Random Access Memory，隨機存取記憶體)73、計時器電路74、I/F(介面)75等。圖2中，將操作面板80、伺服馬達MZ1，MY2、MZ2、MX3、MZ3、旋轉馬達15、25、致動器14、24、及清掃裝置40之I/F彙總表示為I/F75。ROM72中寫入有用以解釋並執行加工程式P2之解釋執行程式P1。RAM73中可重寫地記憶有使用者製作之加工程式P2。加工程式亦稱為NC程式。CPU71將RAM73用作工作區，執行ROM72中記錄之解釋執行程式P1，藉此使電腦作為NC裝置70發揮功能。當然，亦可使藉由解釋執行程式P1實現之功能之一部分或全部藉由ASIC(Application Specific Integrated Circuit，特殊應用積體電路)等其他單元實現。FIG. 2 schematically illustrates the circuit configuration of the NC lathe 1 . In the lathe 1 shown in FIG. 2 , an operation panel 80 , a Z1-axis motor MZ1 , a Y2-axis motor MY2 , a Z2-axis motor MZ2 , an X3-axis motor MX3 , and a Z3-axis motor MZ3 are connected to the NC device 70 to rotate the front spindle 12 The rotary motor 15 for driving, the rotary motor 25 for driving the back main shaft 22 to rotate, the actuator 14 for opening and closing the holding part 13 of the front main shaft 12, the actuator 24 for opening and closing the holding part 23 of the back main shaft 22, and the cleaning device 40 wait. The NC device 70 has a CPU (Central Processing Unit, central processing unit) 71, a ROM (Read Only Memory, read-only memory) 72 as a semiconductor memory, and a RAM (Random Access Memory, random access memory) as a semiconductor memory. ) 73, timer circuit 74, I/F (interface) 75, etc. In FIG. 2 , the I/Fs of the operation panel 80 , servomotors MZ1 , MY2 , MZ2 , MX3 , MZ3 , rotary motors 15 , 25 , actuators 14 , 24 , and cleaning device 40 are collectively shown as I/F75 . An interpreted execution program P1 for interpreting and executing the processing program P2 is written in the ROM 72 . The processing program P2 created by the user is rewritably memorized in the RAM 73 . Processing program is also called NC program. The CPU 71 uses the RAM 73 as a work area, and executes the interpreted execution program P1 recorded in the ROM 72 , whereby the computer functions as the NC device 70 . Of course, part or all of the functions realized by interpreting and executing the program P1 may also be realized by other units such as ASIC (Application Specific Integrated Circuit).

操作面板80具備輸入部81及顯示部82，作為NC裝置70之使用者介面發揮功能。輸入部81例如包含用以自操作員受理操作輸入之按鈕或觸控面板。顯示部82例如包含顯示自操作員受理操作輸入之各種設定之內容或NC車床1相關之各種資訊的顯示器。操作員可使用操作面板80或外部電腦使加工程式P2記憶於RAM73。The operation panel 80 includes an input unit 81 and a display unit 82 , and functions as a user interface of the NC device 70 . The input unit 81 includes, for example, buttons or a touch panel for receiving operation input from an operator. The display unit 82 includes, for example, a display that displays the contents of various settings received from an operator and various information related to the NC lathe 1 . The operator can use the operation panel 80 or an external computer to store the processing formula P2 in the RAM 73 .

Z1軸馬達MZ1依照來自NC裝置70之指令使正面主軸台11向Z軸方向移動。Y2軸馬達MY2依照來自NC裝置70之指令使背面主軸台21向Y軸方向移動。Z2軸馬達MZ2係本技術之伺服裝置之例，依照來自NC裝置70之指令使背面主軸台21向Z軸方向移動。X3軸馬達MX3依照來自NC裝置70之指令使刀架31向X軸方向移動。Z3軸馬達MZ3依照來自NC裝置70之指令使刀架31向Z軸方向移動。各伺服馬達MZ1、MY2、MZ2、MX3、MZ3具有產生與驅動對象11、21、31之位置對應之基準角脈衝之編碼器，基於編碼器之產生脈衝使驅動對象11、21、31之位置與來自NC裝置70之指令一致。圖2中示有Z2軸馬達MZ2之編碼器EN。編碼器EN產生與背面主軸台21之Z軸方向上之位置對應之基準角脈衝，Z2軸馬達MZ2基於編碼器EN產生脈衝使背面主軸台21之Z軸方向上之位置與指令一致。The Z1-axis motor MZ1 moves the front headstock 11 in the Z-axis direction according to a command from the NC device 70 . The Y2-axis motor MY2 moves the back headstock 21 in the Y-axis direction in accordance with a command from the NC device 70 . The Z2-axis motor MZ2 is an example of the servo device of this technology, and moves the back headstock 21 in the Z-axis direction according to the command from the NC device 70 . The X3-axis motor MX3 moves the tool post 31 in the X-axis direction according to the command from the NC device 70 . The Z3-axis motor MZ3 moves the tool post 31 in the Z-axis direction according to the command from the NC device 70 . Each servo motor MZ1, MY2, MZ2, MX3, MZ3 has an encoder that generates a reference angle pulse corresponding to the position of the driven object 11, 21, 31, based on the pulse generated by the encoder, the position of the driven object 11, 21, 31 is aligned with The commands from the NC device 70 agree. Figure 2 shows the encoder EN of the Z2-axis motor MZ2. The encoder EN generates a reference angle pulse corresponding to the position of the back headstock 21 in the Z-axis direction, and the Z2-axis motor MZ2 generates pulses based on the encoder EN to make the position of the back headstock 21 in the Z-axis direction consistent with the command.

旋轉馬達15以依照來自NC裝置70之指令之旋轉速度使正面主軸12旋轉驅動。旋轉馬達25以依照來自NC裝置70之指令之旋轉速度使背面主軸22旋轉驅動。再者，旋轉速度亦稱為轉數，意指每單位時間之旋轉次數。The rotation motor 15 rotates and drives the front spindle 12 at a rotation speed in accordance with a command from the NC device 70 . The rotation motor 25 rotates and drives the back spindle 22 at a rotation speed in accordance with a command from the NC device 70 . Furthermore, the rotational speed is also referred to as the number of revolutions, which means the number of revolutions per unit time.

致動器14依照NC裝置70之控制，經由套筒構件等動力傳遞機構使正面主軸12之固持部13開閉。若打開固持部13，則工件可向Z軸方向移動，若關閉固持部13，則工件被固持於固持部13。致動器24依照NC裝置70之控制，經由套筒構件等動力傳遞機構使背面主軸22之固持部23開閉。若打開固持部23，則將正面加工後之工件向Z軸方向***至固持部23或自固持部23將製品向Z軸方向排出，若關閉承收正面加工後之工件之固持部23，則工件被固持於固持部23。致動器14、24可使用包含線性馬達之伺服馬達、氣缸、油壓缸等。致動器14、24亦可包含滾珠螺桿機構之類的減速機構等。The actuator 14 opens and closes the holding part 13 of the front spindle 12 through a power transmission mechanism such as a sleeve member according to the control of the NC device 70 . If the holding portion 13 is opened, the workpiece can move in the Z-axis direction, and if the holding portion 13 is closed, the workpiece is held by the holding portion 13 . The actuator 24 opens and closes the holding part 23 of the back spindle 22 through a power transmission mechanism such as a sleeve member according to the control of the NC device 70 . If the holding part 23 is opened, the workpiece after the front processing is inserted into the holding part 23 in the Z-axis direction or the product is discharged from the holding part 23 in the Z-axis direction. If the holding part 23 for receiving the workpiece after the front processing is closed, The workpiece is held by the holding portion 23 . Actuators 14 and 24 can use servo motors including linear motors, air cylinders, hydraulic cylinders, and the like. The actuators 14 and 24 may also include a reduction mechanism such as a ball screw mechanism.

清掃裝置40具有開閉連結於噴嘴41、42之流路之電磁閥，藉由依照NC裝置70之控制驅動上述電磁閥而對連結於噴嘴41、42之流路進行開閉。若打開流路，則自噴嘴41、42噴出流體，若關閉流路，則停止自噴嘴41、42噴出流體。The cleaning device 40 has a solenoid valve for opening and closing the flow path connected to the nozzles 41 and 42 , and the flow path connected to the nozzles 41 and 42 is opened and closed by driving the solenoid valve according to the control of the NC device 70 . When the flow path is opened, the fluid is ejected from the nozzles 41 and 42 , and when the flow path is closed, the ejection of the fluid from the nozzles 41 and 42 is stopped.

本具體例中，正面主軸台11為第一主軸台之例，正面主軸12為第一主軸之例，背面主軸台21為第二主軸台之例，背面主軸22為第二主軸之例。又，NC裝置70及對背面主軸台21之Z軸方向上之位置進行檢測之Z2軸馬達MZ2為控制部U1之例。In this specific example, the front headstock 11 is an example of the first headstock, the front headstock 12 is an example of the first headstock, the back headstock 21 is an example of the second headstock, and the back headstock 22 is an example of the second headstock. Also, the NC device 70 and the Z2-axis motor MZ2 that detects the position of the back headstock 21 in the Z-axis direction are examples of the control unit U1.

(3)工件接收處理之具體例：首先，參照圖3、4，對背面主軸22接收固持於正面主軸12之固持部13之正面加工後之工件W0之工件接收處理之例進行說明。圖3模式性地例示背面主軸22向正面加工後之工件W0移動之情況。圖4模式性地例示異物800進入正面加工後之工件W0與背面主軸22之固持部23之間之情況。圖3、4中示有未使用導引軸套之車床之工件接收處理，但於使用導引軸套之情形時，亦進行背面主軸22接收固持於正面主軸12之固持部13之正面加工後之工件W0之工件接收處理。(3) Specific example of workpiece receiving process: First, with reference to FIGS. 3 and 4 , an example of workpiece receiving process in which the rear spindle 22 receives the workpiece W0 after front processing and is held by the holding portion 13 of the front spindle 12 will be described. FIG. 3 schematically illustrates the movement of the back spindle 22 to the workpiece W0 after front processing. FIG. 4 schematically illustrates a situation where a foreign matter 800 enters between the workpiece W0 after front processing and the holding portion 23 of the back spindle 22 . Figures 3 and 4 show the receiving process of a lathe that does not use a guide bush, but in the case of using a guide bush, the back spindle 22 receives and holds the holding part 13 of the front spindle 12 after the front processing. The workpiece receiving process of the workpiece W0.

於工件W0之正面加工時，背面主軸22與工件W0於Z軸方向上分離。為了使背面主軸22固持正面加工後之工件W0，於固持部23打開之狀態下使包含背面主軸22之背面主軸台21向Z軸方向靠近。若於固持部23碰觸工件W0時，Z2軸馬達MZ2欲使背面主軸台21向正面主軸台11移動，則Z2軸馬達MZ2之輸出轉矩增大。以輸出轉矩不會變得過大之方式將Z2軸馬達MZ2之輸出轉矩限制於低於最大轉矩之特定之低轉矩。於該狀態下，若Z2軸馬達MZ2之輸出轉矩成為與特定之低轉矩一致之規定之轉矩幅度，且成為所指定之Z位置(Z軸方向上之位置)之範圍內，則NC裝置70判斷為固持部23與工件W0接觸、即固持部23充分地壓抵於工件W0，而進行關閉固持部23而繼續進行切割加工等加工之控制。When machining the front side of the workpiece W0, the back spindle 22 is separated from the workpiece W0 in the Z-axis direction. In order for the back spindle 22 to hold the workpiece W0 after front processing, the back headstock 21 including the back spindle 22 is brought closer to the Z-axis direction with the holding portion 23 opened. If the Z2-axis motor MZ2 intends to move the rear headstock 21 to the front headstock 11 when the holding part 23 touches the workpiece W0, the output torque of the Z2-axis motor MZ2 increases. The output torque of the Z2-axis motor MZ2 is limited to a specific low torque lower than the maximum torque so that the output torque does not become excessive. In this state, if the output torque of the Z2-axis motor MZ2 becomes the specified torque range consistent with the specified low torque, and falls within the range of the specified Z position (position in the Z-axis direction), then NC The device 70 determines that the holding portion 23 is in contact with the workpiece W0, that is, the holding portion 23 is sufficiently pressed against the workpiece W0, and performs control to close the holding portion 23 and continue processing such as cutting.

於在工件W0附著有碎屑或汙物等異物800之情形時，於背面主軸22之固持部23固持工件W0時，有於Z軸方向上固持工件W0之位置發生偏移、或工件W0傾斜地固持於固持部23之可能性。圖4表示因在工件W0附著有異物800而導致背面主軸22之固持部23固持工件W0之Z位置發生偏移而產生ΔEr之情況。若固持工件W0之位置發生偏移，則工件W0之全長產生誤差，若工件W0傾斜地固持於固持部23，則工件W0之形狀產生誤差。若誤差較大而導致固持部23之Z位置、即背面主軸台21之Z位置成為壓抵檢測之指定範圍外，則進行重新壓抵檢測之處理、或輸出警告而停止連續加工運轉。When a foreign object 800 such as debris or dirt is attached to the workpiece W0, when the workpiece W0 is held by the holding portion 23 of the back spindle 22, the position of holding the workpiece W0 in the Z-axis direction is shifted, or the workpiece W0 is tilted. Possibility of holding on the holding part 23. FIG. 4 shows a situation in which ΔEr is generated due to a deviation of the Z position where the holding portion 23 of the back spindle 22 holds the workpiece W0 due to a foreign object 800 attached to the workpiece W0. If the position where the workpiece W0 is held deviates, an error occurs in the overall length of the workpiece W0, and if the workpiece W0 is obliquely held on the holding portion 23, an error occurs in the shape of the workpiece W0. If the error is large enough to cause the Z position of the holding part 23, that is, the Z position of the back headstock 21 to fall outside the specified range of the compression detection, the processing of the compression detection is performed again, or a warning is output to stop the continuous processing operation.

於關閉固持部23而繼續進行運轉之條件僅為上述壓抵檢測之情形時，有進行錯誤之壓抵檢測之可能性。其原因在於，若背面主軸台21等受衝擊等干擾因素影響，則有Z2軸馬達MZ2之輸出轉矩急遽地上升而誤偵測到背面主軸台21向Z軸方向之移動已完成之情況。又，即便地震或加壓機之振動等來自外部之振動對背面主軸台21等造成影響，亦同樣如此。若進行錯誤之壓抵檢測，則即便背面主軸22之固持部23與工件W0之間無異物，固持部23固持工件W0之位置亦產生誤差，相應地，製品之尺寸精度降低。又，若於錯誤之壓抵檢測時，背面主軸台21之Z位置為指定範圍外，則進行重新壓抵檢測之處理、或輸出警告而停止連續加工運轉。因此，產生因錯誤之壓抵檢測而導致工件加工之週期時間變長或運轉停止等時間之損失，使製造效率降低。When the holding part 23 is closed and the condition for continuing the operation is only the above-mentioned pressure detection, there is a possibility of false pressure detection. The reason is that if the back headstock 21 is affected by disturbance factors such as impact, the output torque of the Z2-axis motor MZ2 may rise sharply, and it may be falsely detected that the movement of the back headstock 21 in the Z-axis direction has been completed. The same applies even if external vibrations such as earthquakes or vibrations of a press machine affect the rear headstock 21 and the like. If the wrong pressing detection is performed, even if there is no foreign object between the holding portion 23 of the back spindle 22 and the workpiece W0, the position where the holding portion 23 holds the workpiece W0 will still be wrong, and accordingly, the dimensional accuracy of the product will be reduced. Also, if the Z position of the back headstock 21 is out of the specified range during the wrong contact detection, the processing of the contact detection is performed again, or a warning is output to stop the continuous machining operation. Therefore, due to erroneous pressure detection, the cycle time of workpiece processing is lengthened or time loss such as stoppage of operation occurs, which reduces manufacturing efficiency.

再者，為了判別於壓抵檢測時異物是否進入工件與背面主軸之固持部之間，考慮將對工件與背面主軸之固持部之間隙供給空氣之氣隙感測器設置於車床。若不存在異物，則工件與背面主軸之固持部之間隙變小而於空氣之供給時，空氣之內壓上升，若存在異物，則工件與背面主軸之固持部之間隙變大而於空氣之供給時，空氣之內壓幾乎不上升。因此，藉由在空氣之供給時對空氣之內壓進行檢測，可更確實地檢測出異物之有無。但是，需要用以設置氣隙感測器之空間，且為了氣隙感測器而需要於背面主軸形成空氣之通道，因此背面主軸之構造變得複雜。因此，車床本身之成本升高。又，必須於每次使背面主軸之固持部靠近工件時供給空氣而對空氣之內壓進行檢測，因此相應地，工件加工之週期時間變長。Furthermore, in order to determine whether foreign matter has entered between the workpiece and the holding portion of the back spindle during the press detection, it is considered to install an air gap sensor that supplies air to the gap between the workpiece and the holding portion of the back spindle in the lathe. If there is no foreign object, the gap between the workpiece and the holding part of the back spindle becomes smaller, and when the air is supplied, the internal pressure of the air rises. If there is a foreign object, the gap between the workpiece and the holding part of the back spindle becomes larger, and the air When supplied, the internal pressure of air hardly rises. Therefore, by detecting the internal pressure of the air when the air is supplied, the presence or absence of foreign matter can be detected more reliably. However, a space for installing the air gap sensor is required, and an air passage needs to be formed on the back spindle for the air gap sensor, so the structure of the back spindle becomes complicated. Therefore, the cost of the lathe itself increases. Also, it is necessary to supply air to detect the internal pressure of the air every time the holding part of the back spindle is brought close to the workpiece, and accordingly, the cycle time of workpiece processing becomes longer.

本具體例中，對Z2軸馬達MZ2賦予特定之轉矩變動並檢測Z軸方向上之背面主軸台21之位置之變化，基於所檢測到之位置之變化，判別背面主軸22之固持部23與工件W0之間有無異物800。藉此，無需於車床設置氣隙感測器之類的專用構造，可縮短工件加工之週期時間，而且可提高工件之加工位置之精度，提高製品之尺寸精度。In this specific example, a specific torque variation is given to the Z2-axis motor MZ2 and the change in the position of the back headstock 21 in the Z-axis direction is detected. Whether there is foreign matter 800 between workpieces W0. Thereby, there is no need to install a special structure such as an air gap sensor on the lathe, the cycle time of workpiece processing can be shortened, and the accuracy of the machining position of the workpiece can be improved, and the dimensional accuracy of the product can be improved.

圖5模式性地例示於將固持部23充分地壓抵於工件W0後對Z2軸馬達MZ2賦予之轉矩變動、背面主軸台21之Z位置之變化、及背面主軸台21之變動幅度ΔZ。此處，曲線G1表示對Z2軸馬達MZ2賦予之轉矩M之時間變化，曲線G2表示不存在異物之情形時之背面主軸台21之Z位置之時間變化，曲線G3按時間順序表示自曲線G2獲得之變動幅度ΔZi，曲線G4表示存在異物之情形時之背面主軸台21之Z位置之時間變化，曲線G5按時間順序表示自曲線G4獲得之變動幅度ΔZi。各曲線G1～G5之橫軸表示時間t。此處，於Z軸方向上，將背面主軸22之固持部23壓抵於工件W0之方向設為+Z方向，將固持部23自工件W0離開之方向設為-Z方向。5 schematically illustrates the variation in torque applied to the Z2-axis motor MZ2, the change in the Z position of the back headstock 21, and the variation range ΔZ of the back headstock 21 after the holding portion 23 is sufficiently pressed against the workpiece W0. Here, the curve G1 represents the time change of the torque M given to the Z2-axis motor MZ2, the curve G2 represents the time change of the Z position of the back headstock 21 when there is no foreign object, and the curve G3 represents the time sequence from the curve G2 The obtained variation range ΔZi, the curve G4 represents the time change of the Z position of the back headstock 21 when there is a foreign object, and the curve G5 represents the variation range ΔZi obtained from the curve G4 in chronological order. The horizontal axis of each of the graphs G1 to G5 represents time t. Here, in the Z-axis direction, the direction in which the holding portion 23 of the back spindle 22 is pressed against the workpiece W0 is referred to as the +Z direction, and the direction in which the holding portion 23 separates from the workpiece W0 is referred to as the −Z direction.

藉由Z2軸馬達MZ2產生之轉矩與供給至Z2軸馬達MZ2之電流之大小成比例。因此，對Z2軸馬達MZ2賦予之轉矩M可藉由對Z2軸馬達MZ2賦予之電流值進行控制。對Z2軸馬達MZ2賦予之轉矩變動係以固持部23壓抵工件W0時之平均轉矩Mmean為中心，以最大值Mmax與最小值Mmin交替地出現之方式進行控制。平均轉矩Mmean與最大值Mmax之差之絕對值、及平均轉矩Mmean與最小值Mmin之差之絕對值為轉矩變動之振幅。最大值Mmax小於Z2軸馬達MZ2之最大轉矩。若藉由進行如曲線G1所示之轉矩控制，異物未進入背面主軸22之固持部23與工件W0之間，則背面主軸台21之Z位置如曲線G2所示般變化。大致為，當對Z2軸馬達MZ2賦予最大值Mmax之轉矩時，背面主軸台21向+Z方向發生位移，當對Z2軸馬達MZ2賦予最小值Mmin之轉矩時，背面主軸台21向-Z方向發生位移。曲線G2所示之變動幅度ΔZi意指背面主軸台21之Z位置之最大值與最小值之差，成為表示自中心值之最大位移之振幅之2倍。曲線G2中示有i=1～6之變動幅度ΔZ1～ΔZ6，該等變動幅度ΔZ1～ΔZ6示於曲線G3中。於異物未進入固持部23與工件W0之間之情形時，各變動幅度ΔZi成為相對穩定之值。The torque generated by the Z2-axis motor MZ2 is proportional to the magnitude of the current supplied to the Z2-axis motor MZ2. Therefore, the torque M given to the Z2-axis motor MZ2 can be controlled by the current value given to the Z2-axis motor MZ2. The torque variation applied to the Z2-axis motor MZ2 is controlled so that the maximum value Mmax and the minimum value Mmin appear alternately around the average torque Mmean when the holding portion 23 is pressed against the workpiece W0. The absolute value of the difference between the average torque Mmean and the maximum value Mmax, and the absolute value of the difference between the average torque Mmean and the minimum value Mmin are the amplitude of the torque variation. The maximum value Mmax is smaller than the maximum torque of the Z2-axis motor MZ2. If foreign matter does not enter between the holding portion 23 of the back spindle 22 and the workpiece W0 by performing the torque control shown in the curve G1, the Z position of the back headstock 21 changes as shown in the curve G2. Roughly, when the torque of the maximum value Mmax is given to the Z2-axis motor MZ2, the back headstock 21 is displaced in the +Z direction, and when the torque of the minimum value Mmin is given to the Z2-axis motor MZ2, the back headstock 21 moves to - A displacement occurs in the Z direction. The variation range ΔZi shown in the curve G2 means the difference between the maximum value and the minimum value of the Z position of the rear headstock 21, and is twice the amplitude representing the maximum displacement from the center value. Curve G2 shows variation ranges ΔZ1 to ΔZ6 for i=1 to 6, and these variation ranges ΔZ1 to ΔZ6 are shown in curve G3. When foreign matter does not enter between the holding portion 23 and the workpiece W0, each variation range ΔZi becomes a relatively stable value.

於異物進入背面主軸22之固持部23與工件W0之間之情形時，背面主軸台21之Z位置如曲線G4所示般變化。曲線G4所示之變動幅度ΔZ1～ΔZ6示於曲線G5中。於異物進入固持部23與工件W0之間之情形時，與異物未進入之情形相比，包含固持部23及工件W0之系統整體之剛性變低。其結果為，變動幅度ΔZi整體上變大，各變動幅度ΔZi成為不均相對較多之值。When a foreign matter enters between the holding portion 23 of the back spindle 22 and the workpiece W0, the Z position of the back spindle table 21 changes as shown by the curve G4. The variation ranges ΔZ1 to ΔZ6 shown in the curve G4 are shown in the curve G5. When a foreign matter enters between the holding portion 23 and the workpiece W0 , the rigidity of the entire system including the holding portion 23 and the workpiece W0 becomes lower compared to a case where the foreign matter does not enter. As a result, the variation width ΔZi becomes large as a whole, and each variation width ΔZi becomes a value with relatively large variations.

因此，藉由基於異物未進入背面主軸22之固持部23與工件W0之間之情形時之主資料D1，設定變動幅度ΔZi之容許之上限值ΔZmax，可判別有無異物。於如曲線G3所示變動幅度ΔZi成為上限值ΔZmax以下之情形時，可判別為異物未進入固持部23與工件W0之間。於如曲線G5所示變動幅度ΔZi超過上限值ΔZmax之情形時，可判別為異物進入固持部23與工件W0之間。Therefore, by setting the allowable upper limit value ΔZmax of the variation range ΔZi based on the master data D1 when foreign matter does not enter between the holding portion 23 of the back spindle 22 and the workpiece W0, the presence or absence of foreign matter can be determined. When the range of variation ΔZi is equal to or less than the upper limit ΔZmax as shown by the curve G3, it can be determined that foreign matter has not entered between the holding portion 23 and the workpiece W0. When the range of variation ΔZi exceeds the upper limit ΔZmax as shown by the curve G5, it can be determined that a foreign object has entered between the holding portion 23 and the workpiece W0.

再者，對Z2軸馬達MZ2賦予之轉矩變動之振幅例如於異物未進入背面主軸22之固持部23與工件W0之間之情形時可設為變動幅度ΔZi成為1～10 μm左右之振幅。轉矩變動之頻率f1例如可設為1～1000 Hz左右。例如於f1=500 Hz之情形時，於0.1秒間對變動幅度ΔZi進行50次取樣。藉由使取樣次數增加，可於短時間內取樣多個變動幅度ΔZi，可精度良好地判別有無異物。又，於判別有無異物時，藉由在短時間內取樣多個變動幅度ΔZi，亦可減少突發性地產生之外在干擾因素之影響。Furthermore, the amplitude of torque fluctuations applied to the Z2-axis motor MZ2 can be set such that the fluctuation range ΔZi is about 1 to 10 μm when foreign matter does not enter between the holding portion 23 of the back spindle 22 and the workpiece W0. The frequency f1 of the torque fluctuation can be set to about 1 to 1000 Hz, for example. For example, in the case of f1=500 Hz, the variation range ΔZi is sampled 50 times within 0.1 second. By increasing the number of sampling times, a plurality of fluctuation ranges ΔZi can be sampled in a short time, and the presence or absence of foreign matter can be judged with high accuracy. In addition, when judging whether there is a foreign object, by sampling a plurality of fluctuation ranges ΔZi in a short time, the influence of sudden external interference factors can also be reduced.

(4)由NC裝置進行之工件接收處理之例：圖6例示由執行解釋執行程式P1之NC裝置70進行之工件接收處理。該處理係於NC裝置70讀取到加工程式P2中所記載之工件接收指令時開始。使用者製作實現如圖5所示之轉矩變動之加工程式並不容易。因此，設為執行解釋執行程式P1之NC裝置70實現Z2軸馬達MZ2之轉矩變動，將其例示於圖6。此處，步驟S102～S108之處理係判別背面主軸22之固持部23與工件W0之間之異物的異物判別處理之例。以下，亦參照圖2～5，對圖6所示之工件接收處理進行說明。(4) Example of workpiece reception processing performed by NC device: FIG. 6 exemplifies workpiece reception processing performed by NC device 70 that executes interpreted execution program P1. This process starts when the NC device 70 reads the workpiece reception command described in the machining formula P2. It is not easy for the user to create a processing program to realize the torque variation as shown in Fig. 5 . Therefore, it is assumed that the NC device 70 that executes the interpreted execution program P1 realizes the torque variation of the Z2-axis motor MZ2, and an example thereof is shown in FIG. 6 . Here, the processing of steps S102 to S108 is an example of a foreign object identification process for identifying a foreign object between the holding portion 23 of the back spindle 22 and the workpiece W0. In the following, the workpiece receiving process shown in FIG. 6 will be described with reference to FIGS. 2 to 5 as well.

若開始工件接收處理，則NC裝置70控制圖2所示之致動器24而預先將背面主軸22之固持部23設為打開之狀態，且將Z2軸馬達MZ2限制於特定之低轉矩，於該狀態下驅動Z2軸馬達MZ2而使背面主軸台21向正面主軸台11移動(步驟S102)。若將固持部23壓抵於固持於正面主軸12之工件W0，則由於Z2軸馬達MZ2欲使背面主軸台21向正面主軸台11移動，故而Z2軸馬達MZ2之輸出轉矩上升。When the workpiece receiving process is started, the NC device 70 controls the actuator 24 shown in FIG. 2 to set the holding portion 23 of the back spindle 22 in an open state in advance, and limits the Z2-axis motor MZ2 to a specific low torque, In this state, the Z2-axis motor MZ2 is driven to move the back headstock 21 toward the front headstock 11 (step S102 ). If the holding portion 23 is pressed against the workpiece W0 held on the front spindle 12, the output torque of the Z2-axis motor MZ2 increases because the Z2-axis motor MZ2 intends to move the back headstock 21 to the front headstock 11.

因此，NC裝置70自Z2軸馬達MZ2取得輸出轉矩之值與背面主軸台21之Z位置，使輸出轉矩之值處於規定之轉矩幅度，且判斷背面主軸台21是否進入由加工程式P2指定之Z位置之範圍內(步驟S104)。由加工程式P2指定之Z位置之範圍係背面主軸22之固持部23固持工件W0之範圍。當然，固持部23固持工件W0之範圍亦可藉由NC裝置70由利用加工程式P2所指定之目標之Z位置求出。於在特定期間，輸出轉矩之值處於規定之轉矩幅度，而背面主軸台21進入指定範圍內之情形時，NC裝置70使處理進入步驟S106。於儘管輸出轉矩之值處於規定之轉矩幅度但不滿足步驟S104之條件之情形時、或儘管背面主軸台21進入指定範圍內但不滿足步驟S104之條件之情形時，使處理進入步驟S112。再者，於步驟S104之判斷處理中，為了去除因干擾因素所產生之輸出轉矩之突出值，NC裝置70亦可進行如下判斷：自於特定期間所獲得之複數個輸出轉矩值去除最大值、或按由大至小之順序去除2個以上之特定數之值後，是否處於規定之轉矩幅度。Therefore, the NC device 70 obtains the value of the output torque and the Z position of the back headstock 21 from the Z2-axis motor MZ2, makes the value of the output torque fall within a specified torque range, and judges whether the back headstock 21 enters the processing formula P2 Within the range of the specified Z position (step S104). The range of the Z position specified by the machining formula P2 is the range where the holding part 23 of the back spindle 22 holds the workpiece W0. Of course, the range where the holding part 23 holds the workpiece W0 can also be obtained by the NC device 70 from the target Z position specified by the machining formula P2. When the value of the output torque is within the specified torque range and the back headstock 21 is within the specified range during the specified period, the NC device 70 advances the process to step S106. When the condition of step S104 is not satisfied although the value of the output torque is within the specified torque range, or the condition of step S104 is not satisfied even though the back headstock 21 is within the specified range, the process proceeds to step S112 . Furthermore, in the judgment process of step S104, in order to remove the outstanding value of output torque due to disturbance factors, the NC device 70 may also make the following judgment: remove the maximum value, or after removing two or more specific numbers in descending order, whether it is within the specified torque range.

步驟S106中，NC裝置70將如圖5之曲線G1所示之特定之轉矩變動賦予至Z2軸馬達MZ2而自Z2軸馬達MZ2取得背面主軸台21之Z位置，求出背面主軸台21之Z位置之變動幅度ΔZi、即Z位置之變化。其次，NC裝置70判斷背面主軸台21之Z位置之變動幅度是否為所容許之上限值ΔZmax以下(步驟S108)。與上限值ΔZmax進行對比之變動幅度可為變動幅度ΔZi之最大值，可為自變動幅度ΔZi去除最大值、或按由大至小之順序去除2個以上之特定數之值後之最大值，亦可為變動幅度ΔZi之平均值。In step S106, the NC device 70 applies a specific torque variation as shown in the curve G1 of FIG. The variation range ΔZi of the Z position, that is, the change of the Z position. Next, the NC device 70 judges whether or not the variation range of the Z position of the back headstock 21 is equal to or less than the allowable upper limit value ΔZmax (step S108 ). The fluctuation range compared with the upper limit value ΔZmax can be the maximum value of the fluctuation range ΔZi, or the maximum value obtained by subtracting the maximum value from the fluctuation range ΔZi, or removing two or more specific numbers in descending order. , It can also be the average value of the variation range ΔZi.

於如圖5之曲線G3所示變動幅為上限值ΔZmax以下之情形時，檢測出背面主軸22之固持部23與工件W0之間無異物。於該情形時，NC裝置70以關閉背面主軸22之固持部23之方式使致動器24驅動，繼續進行連續加工運轉(步驟S110)，使工件接收處理結束。When the fluctuation range is below the upper limit ΔZmax as shown in the curve G3 of FIG. 5 , it is detected that there is no foreign object between the holding portion 23 of the back spindle 22 and the workpiece W0. In this case, the NC device 70 drives the actuator 24 to close the holding portion 23 of the back spindle 22, continues the continuous machining operation (step S110), and completes the workpiece receiving process.

於如圖5之曲線G5所示變動幅度超出上限值ΔZmax之情形時，如圖4所示，檢測出背面主軸22之固持部23與工件W0之間存在異物800。於該情形時，NC裝置70使處理進入步驟S112。When the fluctuation range exceeds the upper limit ΔZmax as shown in the curve G5 of FIG. 5 , as shown in FIG. 4 , it is detected that there is a foreign object 800 between the holding portion 23 of the back spindle 22 and the workpiece W0. In this case, the NC device 70 advances the process to step S112.

步驟S112之處理係於步驟S104、108中條件不成立之情形時進行。於步驟S112中，NC裝置70關於步驟S102～S108之異物判別處理判斷是否進行由加工程式P2指定之次數之重試。當然，重試之次數不取決於加工程式P2，亦可為由解釋執行程式P1等決定之次數。於重試未達到指定次數之情形時，NC裝置70進行特定之清掃處理(步驟S114)，使處理返回至步驟S102。於重試達到指定次數之情形時，NC裝置70輸出表示無法繼續進行工件之連續加工運轉之警告，使工件之連續加工運轉停止(步驟S116)，使工件接收處理結束。警告之輸出包含在圖2所示之顯示部82顯示警告、自未圖示之聲頻輸出裝置輸出警告音等。The processing of step S112 is performed when the conditions in steps S104 and S108 are not satisfied. In step S112, the NC device 70 judges whether or not to perform retries for the number of times specified by the machining formula P2 with respect to the foreign matter discrimination processing in steps S102 to S108. Of course, the number of retries does not depend on the processing program P2, and can also be determined by interpreting and executing the program P1. When the number of retries has not reached the designated number of times, the NC device 70 performs a specific cleaning process (step S114), and returns the process to step S102. When the number of retries reaches the specified number of times, the NC device 70 outputs a warning indicating that the continuous machining operation of the workpiece cannot be continued, stops the continuous machining operation of the workpiece (step S116), and ends the workpiece receiving process. The output of the warning includes displaying a warning on the display unit 82 shown in FIG. 2 , outputting a warning sound from an audio output device not shown, and the like.

圖7模式性地例示步驟S114中進行之清掃處理。若開始清掃處理，則NC裝置70使圖2所示之Z2軸馬達MZ2驅動而使背面主軸台21向遠離正面主軸台11之方向移動。若背面主軸22之固持部23使背面主軸台21退避至成為噴嘴42之前端之位置，則NC裝置70於一定期間使清掃裝置40驅動，自噴嘴41對工件W0噴出清掃用流體，自噴嘴42對固持部23噴出清掃用流體。將該狀態示於圖7。於流體為空氣之情形時，自噴嘴41對工件W0吹送空氣而藉由空氣將異物800自工件W0吹飛，自噴嘴42對固持部23吹送空氣而藉由空氣將異物自固持部23吹飛。於流體為冷卻劑之情形時，自噴嘴41將冷卻劑澆淋至工件W0而藉由冷卻劑沖洗異物800，自噴嘴42將冷卻劑澆淋至固持部23而藉由冷卻劑沖洗異物。FIG. 7 schematically illustrates the cleaning process performed in step S114. When the cleaning process is started, the NC device 70 drives the Z2-axis motor MZ2 shown in FIG. 2 to move the back headstock 21 in a direction away from the front headstock 11 . When the holding portion 23 of the back spindle 22 retracts the back spindle base 21 to a position where it becomes the front end of the nozzle 42, the NC device 70 drives the cleaning device 40 for a certain period of time, and the cleaning fluid is ejected from the nozzle 41 to the workpiece W0, and the cleaning fluid is sprayed from the nozzle 42. The cleaning fluid is ejected to the holding portion 23 . This state is shown in FIG. 7 . When the fluid is air, the air is blown from the nozzle 41 to the workpiece W0, and the foreign matter 800 is blown away from the workpiece W0 by the air, and the air is blown from the nozzle 42 to the holding part 23, and the foreign matter is blown away from the holding part 23 by the air. . When the fluid is coolant, the coolant is poured from the nozzle 41 onto the workpiece W0 to flush the foreign object 800 with the coolant, and the coolant is poured from the nozzle 42 to the holding portion 23 to flush the foreign object with the coolant.

若進行清掃處理，則進行圖6之步驟S102～S108之異物判別處理。若於步驟S102中背面主軸台21向正面主軸台11移動，則如圖8所例示般背面主軸22之固持部23壓抵於工件W0。此處，若去除異物800，則固持部23固持工件W0之Z位置之偏移ΔEr變少。又，於圖6之步驟S106中所取得之變動量ΔZi整體上變少，背面主軸台21之Z位置之變動量成為上限值ΔZmax以下，而繼續進行連續加工運轉。If the cleaning process is performed, the foreign matter discrimination process of steps S102 to S108 in FIG. 6 is performed. If the back headstock 21 moves toward the front headstock 11 in step S102 , the holding portion 23 of the back headstock 22 is pressed against the workpiece W0 as illustrated in FIG. 8 . Here, if the foreign matter 800 is removed, the shift ΔEr in the Z position where the holding portion 23 holds the workpiece W0 becomes smaller. Also, the amount of variation ΔZi acquired in step S106 of FIG. 6 decreases as a whole, and the amount of variation in the Z position of the back headstock 21 becomes below the upper limit value ΔZmax, and the continuous machining operation is continued.

如以上所說明，藉由基於在對Z2軸馬達MZ2賦予了特定之轉矩變動之狀態下對背面主軸台21所檢測出之Z位置之變化，判別背面主軸22之固持部23與工件W0之間有無異物，可獲得各種有用之效果。本具體例由於無需設置如氣隙感測器之專用構造，故而可抑制車床之大型化及成本上升，亦可縮短工件加工之週期時間。又，由於可減少衝擊等干擾因素之影響，故而可精度良好地判別固持部23與工件W0之間有無異物。因此，本具體例可提高工件之加工位置之精度，從而可提高製品之尺寸精度。As described above, the distance between the holding portion 23 of the back spindle 22 and the workpiece W0 is determined based on the change in the Z position detected by the back headstock 21 in a state where a specific torque variation is applied to the Z2-axis motor MZ2. With or without foreign matter in between, various useful effects can be obtained. In this specific example, since there is no need to install a special structure such as an air gap sensor, the increase in size and cost of the lathe can be suppressed, and the cycle time of workpiece processing can be shortened. In addition, since the influence of disturbance factors such as impact can be reduced, it is possible to accurately determine whether there is a foreign object between the holding portion 23 and the workpiece W0. Therefore, this specific example can improve the accuracy of the machining position of the workpiece, thereby improving the dimensional accuracy of the product.

(5)變化例：本發明可考慮各種變化例。例如可應用本技術之車床並不限定於主軸移動型車床，亦可為正面主軸不移動之主軸固定型車床等。(5) Variations: The present invention can consider various variations. For example, the lathes to which this technology can be applied are not limited to lathes with movable spindles, but can also be fixed-spindle lathes with non-moving front spindles.

上述清掃裝置40具有工件清掃用噴嘴41及第二固持部清掃用噴嘴42兩者，但亦可省略噴嘴41、42之一者。即便省略噴嘴41、42之一者，亦有去除異物之可能性，因此可應用本技術。當然，可自噴嘴41吹出空氣而自噴嘴42噴出冷卻劑，亦可自噴嘴41噴出冷卻劑而自噴嘴42吹出空氣。再者，清掃裝置40之噴嘴41、42亦可組入至正面主軸12或背面主軸22之內部。The cleaning device 40 has both the workpiece cleaning nozzle 41 and the second holding portion cleaning nozzle 42 , but either of the nozzles 41 and 42 may be omitted. Even if one of the nozzles 41 and 42 is omitted, there is a possibility of removing foreign matter, so this technique can be applied. Of course, the air may be blown out from the nozzle 41 and the coolant may be blown out from the nozzle 42 , or the coolant may be blown out from the nozzle 41 and the air may be blown out from the nozzle 42 . Furthermore, the nozzles 41 and 42 of the cleaning device 40 can also be incorporated into the front main shaft 12 or the back main shaft 22 .

於圖6之步驟S108中判斷背面主軸台21之Z位置之變動幅度是否為上限值ΔZmax以下的處理可為將變動幅度ΔZi之移動平均值與上限值ΔZmax進行對比之處理，亦可為利用相對於圖5所示之主資料D1之圖案匹配之處理。In step S108 of FIG. 6 , the process of judging whether the variation range of the Z position of the back headstock 21 is below the upper limit ΔZmax may be a process of comparing the moving average value of the variation range ΔZi with the upper limit value ΔZmax, or may be Process using pattern matching with respect to master data D1 shown in FIG. 5 .

於將變動幅度ΔZi之移動平均值與上限值ΔZmax進行對比之情形時，將取得移動平均值之數設為N(N為2以上之整數)，如下所述將變動幅度之N個移動平均值與上限值ΔZmax進行對比。首先，按照變動幅度ΔZ1、ΔZ2、…之順序將N個之平均值與上限值ΔZmax進行對比。其次，按照變動幅度ΔZ2、ΔZ3、…之順序將N個之平均值與上限值ΔZmax進行對比。以下，將逐一地使變動幅度偏移所得之N個之平均值與上限值ΔZmax進行對比。因此，即便各變動幅度ΔZi中某一變動幅度因衝擊等干擾因素而被較大地檢測出，由於將連續之複數個變動幅度ΔZi進行平均而與上限值ΔZmax進行對比，故而干擾因素對有無異物之判別之影響亦變小。When comparing the moving average of the fluctuation range ΔZi with the upper limit value ΔZmax, set the number of moving averages to be N (N is an integer greater than 2), and divide the N moving averages of the fluctuation range as follows The value is compared with the upper limit value ΔZmax. First, compare the average value of N items with the upper limit value ΔZmax in the order of the variation range ΔZ1, ΔZ2, .... Next, compare the average value of N pieces with the upper limit value ΔZmax in the order of variation range ΔZ2, ΔZ3, . . . Hereinafter, the average value of N pieces obtained by shifting the fluctuation range one by one is compared with the upper limit value ΔZmax. Therefore, even if a certain fluctuation range among the fluctuation ranges ΔZi is detected largely due to interference factors such as impacts, since the continuous plural fluctuation ranges ΔZi are averaged and compared with the upper limit value ΔZmax, the interference factors have no effect on the presence or absence of foreign objects. The influence of judgment is also reduced.

於利用相對於主資料D1之圖案匹配之情形時，藉由使用主資料D1及背面主軸台21之Z位置之檢測資料(例如圖5所示之資料D2)，可如下所述判別異物之有無。此處，將相對於主資料D1與檢測資料D2之一致度(設為C)之閾值設為TH(TH＞0)。首先，設為將背面主軸22之固持部23壓抵於工件W0並對Z2軸馬達MZ2賦予特定之轉矩變動之狀態，NC裝置70取得表示藉由Z2軸馬達MZ2而關於背面主軸台21所檢測到之Z位置之變化的檢測資料D2。其次，NC裝置70進行主資料D1與檢測資料D2之圖案匹配，求出主資料D1與檢測資料D2之一致度C。於一致度C為閾值TH以上之情形時，可判別為無異物，於一致度C未達閾值TH之情形時，可判別為有異物。圖案匹配係針對背面主軸台21之Z位置使用多個檢測資料D2，因此即便背面主軸台21之Z位置之某一檢測值因干擾因素而成為異常值，整體上亦成為極小之差異，干擾因素對有無異物之判別之影響減小。In the case of using pattern matching with respect to the main data D1, by using the main data D1 and the detection data of the Z position of the back headstock 21 (such as the data D2 shown in FIG. 5 ), the presence or absence of foreign matter can be judged as follows . Here, the threshold value of the coincidence degree (set as C) with respect to the master data D1 and the detection data D2 is set to TH (TH>0). First, it is assumed that the holding portion 23 of the back spindle 22 is pressed against the workpiece W0 and a specific torque variation is given to the Z2-axis motor MZ2, and the NC device 70 obtains the information indicating that the Z2-axis motor MZ2 is operating on the back headstock 21. Detection data D2 of the detected change in the Z position. Next, the NC device 70 performs pattern matching of the master data D1 and the detection data D2 to obtain the degree of consistency C between the master data D1 and the detection data D2. When the degree of coincidence C is equal to or greater than the threshold TH, it can be judged that there is no foreign matter, and when the degree of coincidence C is less than the threshold TH, it can be judged that there is a foreign matter. Pattern matching uses a plurality of detection data D2 for the Z position of the back headstock 21. Therefore, even if a certain detection value of the Z position of the back headstock 21 becomes an abnormal value due to interference factors, the overall difference is extremely small. The interference factors The impact on the judgment of whether there is foreign matter is reduced.

進而，於工件接收處理中，對Z2軸馬達MZ2開始賦予轉矩變動之時點亦可為背面主軸22之固持部23壓抵於工件W0之前。Furthermore, in the workpiece receiving process, the timing at which torque variation is started to be applied to the Z2-axis motor MZ2 may be that the holding portion 23 of the back spindle 22 is pressed in front of the workpiece W0.

圖9表示由NC裝置70進行之工件接收處理之另一例。圖9所示之工件接收處理與圖6所示之工件接收處理相比，步驟S104～S106被替換為步驟S202～S206。若NC裝置70將背面主軸22之固持部23設為打開之狀態，且將Z2軸馬達MZ2限制於特定之低轉矩，於該狀態下，使背面主軸台21向正面主軸台11移動(步驟S102)，則開始對Z2軸馬達MZ2賦予特定之轉矩變動之處理(步驟S202)。開始步驟S202之處理之時點設為背面主軸台21移動至於Z軸方向上固持部23壓抵於工件W0之前的特定位置之時點。再者，亦可於在Z軸方向上使背面主軸台21開始移動後立即進行步驟S202之處理。FIG. 9 shows another example of the workpiece receiving process performed by the NC device 70 . In the workpiece receiving process shown in FIG. 9 , steps S104 to S106 are replaced with steps S202 to S206 compared with the workpiece receiving process shown in FIG. 6 . If the NC device 70 sets the holding part 23 of the back spindle 22 to an open state, and limits the Z2-axis motor MZ2 to a specific low torque, in this state, the back headstock 21 is moved toward the front headstock 11 (step S102), then start the process of giving specific torque variation to the Z2-axis motor MZ2 (step S202). The point at which the process of step S202 is started is defined as the point at which the back headstock 21 moves to a specific position before the holding portion 23 presses against the workpiece W0 in the Z-axis direction. Furthermore, the process of step S202 may be performed immediately after the back headstock 21 starts to move in the Z-axis direction.

其次，NC裝置70判斷背面主軸台21是否進入由加工程式P2指定之Z位置之範圍內(步驟S204)。於在特定期間，背面主軸台21進入指定範圍內之情形時，NC裝置70使處理進入步驟S206。於不滿足步驟S204之條件之情形時，使處理進入步驟S112。Next, the NC device 70 judges whether the back headstock 21 is within the range of the Z position specified by the machining formula P2 (step S204). When the back headstock 21 is within the specified range during the specific period, the NC device 70 advances the process to step S206. When the condition of step S204 is not satisfied, the process proceeds to step S112.

於步驟S206中，由於已對Z2軸馬達MZ2賦予特定之轉矩變動，故而NC裝置70自Z2軸馬達MZ2取得背面主軸台21之Z位置，求出背面主軸台21之Z位置之變動幅度ΔZi、即Z位置之變化。其次，NC裝置70判斷背面主軸台21之Z位置之變動幅度是否為所容許之上限值ΔZmax以下(步驟S108)。於變動幅度為上限值ΔZmax以下之情形時，NC裝置70以關閉背面主軸22之固持部23之方式使致動器24驅動，而繼續進行連續加工運轉(步驟S110)，使工件接收處理結束。於變動幅度超出上限值ΔZmax之情形時，進行包含清掃處理之上述處理(步驟S112～S116)。In step S206, since a specific torque variation has been given to the Z2-axis motor MZ2, the NC device 70 obtains the Z position of the back headstock 21 from the Z2-axis motor MZ2, and obtains the variation range ΔZi of the Z position of the back headstock 21 , That is, the change of Z position. Next, the NC device 70 judges whether or not the variation range of the Z position of the back headstock 21 is equal to or less than the allowable upper limit value ΔZmax (step S108 ). When the variation range is below the upper limit ΔZmax, the NC device 70 drives the actuator 24 to close the holding portion 23 of the back spindle 22, and continues the continuous machining operation (step S110), and the workpiece receiving process ends. . When the fluctuation range exceeds the upper limit value ΔZmax, the above-mentioned processing including cleaning processing is performed (steps S112 to S116).

即便進行圖9所示之工件接收處理，亦可精度良好地判別固持部23與工件W0之間有無異物，可抑制車床之大型化及成本上升，縮短工件加工之週期時間。Even if the workpiece receiving process shown in FIG. 9 is performed, the presence or absence of foreign matter between the holding portion 23 and the workpiece W0 can be judged with high accuracy, and the increase in size and cost of the lathe can be suppressed, and the cycle time for workpiece processing can be shortened.

(6)總結：如以上所說明，根據本發明，藉由各種態樣，可提供能夠提高製品之尺寸精度之車床等技術。當然，即便為僅由獨立請求項之構成要件構成之技術，亦可獲得上述基本之作用、效果。又，亦可實施將上述例中所揭示之各構成相互替換或變更組合後之構成、將公知技術及上述例中所揭示之各構成相互替換或變更組合後之構成等。本發明亦包含該等構成等。(6) Summary: As explained above, according to the present invention, technologies such as lathes capable of improving the dimensional accuracy of products can be provided through various aspects. Of course, even if it is a technology composed of only the constituent elements of the independent claims, the above-mentioned basic functions and effects can also be obtained. In addition, it is also possible to implement a configuration in which the respective configurations disclosed in the above examples are mutually replaced or modified and combined, and a configuration in which known techniques and the respective configurations disclosed in the above examples are mutually replaced or modified and combined may be implemented. The present invention also includes these constitutions and the like.

1:車床 10:基座 11:正面主軸台(第一主軸台之例) 12:正面主軸(第一主軸之例) 13:固持部 14:致動器 15:旋轉馬達 18:導引軸套 20:基座 21:背面主軸台(第二主軸台之例) 22:背面主軸(第二主軸之例) 23:固持部 24:致動器 25:旋轉馬達 30:基座 31:刀架 40:清掃裝置 41:噴嘴 42:噴嘴 70:NC裝置 71:CPU 72:ROM 73:RAM 74:計時器電路 75:I/F(介面) 80:操作面板 81:輸入部 82:顯示部 800:異物 AX1:主軸中心線 AX2:主軸中心線 EN:編碼器 MX3:X3軸馬達 MY2:Y2軸馬達 MZ1:Z1軸馬達 MZ2:Z2軸馬達(伺服裝置之例) MZ3:Z3軸馬達 T0:工具 T1:切割工具 U1:控制部 W0:工件 W1:工件 W2:工件1: lathe 10: Base 11: Front headstock (example of the first headstock) 12: Front spindle (example of the first spindle) 13: Holding part 14: Actuator 15:Rotary motor 18: Guide bushing 20: base 21: Rear headstock (example of the second headstock) 22: Rear spindle (example of the second spindle) 23: Holding part 24: Actuator 25:Rotary motor 30: base 31: Knife holder 40: cleaning device 41: Nozzle 42: Nozzle 70:NC device 71:CPU 72: ROM 73: RAM 74: Timer circuit 75: I/F (interface) 80: Operation panel 81: input part 82: Display part 800: foreign body AX1: spindle centerline AX2: spindle centerline EN:encoder MX3: X3 axis motor MY2: Y2 axis motor MZ1: Z1 axis motor MZ2: Z2-axis motor (example of servo device) MZ3: Z3 axis motor T0: Tool T1: Cutting tool U1: control unit W0: Workpiece W1: Workpiece W2: Workpiece

圖1係模式性地表示車床之構成例之圖。圖2係模式性地表示車床之電路之構成例之方塊圖。圖3係模式性地表示第二主軸向正面加工後之工件移動之例的圖。圖4係模式性地表示異物進入正面加工後之工件與第二固持部之間之例的圖。圖5係模式性地表示對伺服裝置賦予之轉矩變動、第二主軸台之位置之變化、及第二主軸台之變動幅度之例的圖。圖6係表示由數值控制裝置進行之工件接收處理之例之流程圖。圖7係模式性地表示使第二主軸自工件離開而進行清掃之例的圖。圖8係模式性地表示於清掃後使第二主軸向工件移動之例的圖。圖9係表示由數值控制裝置進行之工件接收處理之另一例的流程圖。FIG. 1 is a diagram schematically showing a configuration example of a lathe. Fig. 2 is a block diagram schematically showing an example of a circuit configuration of a lathe. Fig. 3 is a diagram schematically showing an example of movement of the second spindle to the workpiece after front machining. Fig. 4 is a diagram schematically showing an example in which foreign matter enters between the workpiece after front processing and the second holding part. FIG. 5 is a diagram schematically showing an example of a variation in torque applied to the servo device, a change in the position of the second headstock, and a variation range of the second headstock. Fig. 6 is a flow chart showing an example of workpiece reception processing performed by the numerical controller. Fig. 7 is a diagram schematically showing an example of cleaning by separating the second spindle from the workpiece. Fig. 8 is a diagram schematically showing an example of moving the second spindle to the workpiece after cleaning. Fig. 9 is a flow chart showing another example of workpiece reception processing performed by the numerical controller.

Claims

一種車床，其具備：第一主軸台，其設置有具有固持工件之第一固持部之第一主軸；第二主軸台，其設置有與上述第一主軸對向且具有固持上述工件之第二固持部之第二主軸；伺服裝置，其使該第二主軸台向上述第二主軸之中心線方向移動；及控制部，其控制上述第一固持部及上述第二固持部之開閉動作、以及經由上述伺服裝置進行之上述第二主軸台之移動；且上述控制部於打開上述第二固持部且將上述伺服裝置限制於低於最大轉矩之轉矩之狀態下，使上述第二主軸台向上述第一主軸台移動，對上述伺服裝置賦予特定之轉矩變動並檢測上述中心線方向上之上述第二主軸台之位置之變動幅度或位置之圖案，基於在上述第二固持部固持上述工件之範圍內所檢測到之位置之變動幅度或位置之圖案，判別上述第二固持部與上述工件之間有無異物。 A lathe comprising: a first headstock, which is provided with a first spindle having a first holding portion for holding a workpiece; a second headstock, which is provided with a second spindle facing the first spindle and having a second spindle for holding the workpiece. The second spindle of the holding part; the servo device, which moves the second headstock to the centerline direction of the second spindle; and the control part, which controls the opening and closing of the first holding part and the second holding part, and The movement of the second headstock via the servo device; and the control part makes the second headstock in a state where the second holding part is opened and the servo device is limited to a torque lower than the maximum torque. Move to the first headstock, apply a specific torque variation to the servo device and detect the variation range or position pattern of the second headstock in the direction of the center line, based on holding the above-mentioned The variation range or position pattern of the detected position within the range of the workpiece is used to determine whether there is a foreign object between the second holding portion and the workpiece.

如請求項1之車床，其中此車床進而具備清掃裝置，該清掃裝置可對固持於上述第一固持部之上述工件及自該工件離開之上述第二固持部中之至少一者進行清掃，上述控制部若於判別上述第二固持部與上述工件之間有無異物之異物判別處理中，判別為於上述第二固持部與上述工件之間存在異物，則使上述第二主軸台向遠離上述第一主軸台之方向移動而使上述清掃裝置進行清掃，並再次進行上述異物判別處理。 The lathe according to claim 1, wherein the lathe is further equipped with a cleaning device that can clean at least one of the above-mentioned workpiece held in the above-mentioned first holding part and the above-mentioned second holding part separated from the workpiece, the above-mentioned If the control unit judges that there is a foreign object between the second holding portion and the workpiece during the foreign object determination process for determining whether there is a foreign object between the second holding portion and the workpiece, the control unit moves the second headstock away from the first headstock. The headstock is moved in one direction so that the cleaning device cleans up, and the foreign matter discrimination process is performed again.