TW202245968A - lathe - Google Patents

Abstract

Provided is a lathe that can eliminate the need for a device dedicated to detection of breakage of a parting tool. A lathe 1 is provided with a spindle (11), a counter spindle (16), a tool rest 30, a stopper 40, a driving unit (31), and a control unit (70). The stopper 40 positions a bar material B1 at an advanced position P1 where the bar material B1 pushed forward by a material feeding machine 20 from the spindle (11) having released the bar material B1 bumps, and is retractable from the advanced position P1. After completion of an operation of cutting off a workpiece W1 by a parting tool TO3 in a state where the stopper 40 is retracted from the advanced position P1, the control unit (70) carries out a control of causing the driving unit (31) to move the stopper 40 to a position (P3) between the bar material B1 grasped by the spindle (11) and the workpiece W1 grasped by the counter spindle (16), and, when a torque generated by the driving unit (31) exceeds reference torque for detecting the bump of the stopper 40 against the bar material B1, carries out a process (S124) for a case in which the parting tool TO3 is broken.

Description

lathe

The present invention relates to a lathe for processing bar material supplied by a material feeder and equipped with a mechanism for detecting breakage of a cutting knife.

As a lathe, there is known an NC (Numerical Control: Numerical Control) lathe that cuts a workpiece from a bar supplied by a feeder to form a product. When the material feeding machine is installed on the front spindle of the NC lathe to insert the bar from the rear direction, it is necessary to determine the position to hold the bar on the front spindle. Therefore, a stopper for positioning the bar pushed forward by the main shaft is provided on the NC lathe. The NC lathe with the stopper first inserts the bar from the rear to the front spindle with the feeder, and the bar pushed out from the front spindle abuts against the stopper for positioning, and the positioned bar is held by the front spindle. Retract the stopper from the moving path of the bar. Then, the NC lathe processes the front end of the bar held by the front spindle by the tool installed on the tool post, and the front end of the bar processed by the front is controlled by the back spindle, and the cutting tool installed on the tool post Cut off the rod. In this way, the front processed workpiece held by the back spindle is cut from the bar. Furthermore, the NC lathe processes the back side of the workpiece with the tool installed on the tool post, and discharges the obtained product.

If the cutting knife is damaged, the workpiece cannot be cut from the bar. Therefore, the NC lathe has a mechanism for detecting breakage of the cutting blade. The tool post of the automatic lathe disclosed in Patent Document 1 is provided with a breakage detection device for a cutting blade including a drive plate, a detection rod, and a proximity sensor. When the tool holder moves from the end position of the cutting process to the start position of the process through the front reset of the guide sleeve, if the workpiece remains, the detection rod contacts the workpiece, and the driving plate rotates. The proximity sensor detects the rotation of the driving plate as a breakage detection of the cutter. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-90158

[Problem to be solved by the invention]

In the above-mentioned automatic lathe, a special breakage detection device for the cutting blade is required to detect the breakage of the cutting blade. In the lathe, it seeks to detect the breakage of the cutting knife, and on the other hand, it also seeks to save space or reduce costs.

The present invention discloses a lathe that does not need a special device for detecting the breakage of the cutting knife. [Technical means to solve the problem]

The lathe of the present invention has the following aspects. It is a lathe for processing bars supplied by a material supply machine, and has: The main shaft, which can freely hold the above-mentioned bar inserted from the rear; facing the main shaft, which can freely hold the front end of the above-mentioned bar protruding forward from the above-mentioned main shaft; A knife holder, which is equipped with a cutting knife for cutting the workpiece including the front end of the above-mentioned bar held by the opposing spindle from the above-mentioned bar; The stopper is used to position the bar at the advanced position before the bar is pushed forward by the main shaft after the bar is released by the material feeding machine, and can retreat from the advanced position; a driving part which moves the above-mentioned stopper; and A control unit that moves the stopper to the spindle gripped by the drive unit when the operation of cutting the workpiece with the cutting knife is completed while the stopper is retracted from the advanced position. The control of the position between the above-mentioned bar and the above-mentioned workpiece grasped by the above-mentioned counter-spindle is performed when the torque generated by the above-mentioned drive part exceeds the reference torque for detecting whether the above-mentioned stopper is in contact with the above-mentioned bar. Handling of broken knives. [Effect of Invention]

According to the present invention, it is possible to provide a lathe that does not require a dedicated device for detecting breakage of the cutting blade.

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 shown in the embodiments are not necessarily essential to the solution means of the invention.

(1) Summary of the technology included in the present invention: First, the outline of the technology included in the present invention will be described with reference to the examples shown in FIGS. 1 to 12 . In addition, the diagrams in this case are diagrams showing typical examples, and sometimes the magnification ratios in each direction shown in these diagrams are different, and sometimes the diagrams do not match. Of course, each element of this technology is not limited to the specific example shown by a code|symbol.

[Form 1] As shown in Figures 1, 5, 7, etc., a lathe 1 of an aspect of the present technology is a lathe 1 for processing a bar B1 supplied by a material supply machine 20, and is equipped with a main shaft (such as a front main shaft 11), an opposite main shaft (for example, the back spindle 16 ), the tool post 30 , the stopper 40 , a driving unit (for example, the tool post driving unit 31 ), and a control unit (for example, the NC device 70 ). The above-mentioned main shaft (11) can freely hold the above-mentioned rod B1 inserted from behind. The facing main shaft (16) can releasably hold the front end B1a of the bar B1 protruding forward from the main shaft (11). A cutting tool TO3 for cutting the workpiece W1 including the front end B1a of the bar B1 held by the counter spindle (16) from the bar B1 is mounted on the tool post 30 . The above-mentioned stopper 40 positions the above-mentioned bar B1 on the forward position P1 before the above-mentioned bar B1 is pushed forward by the above-mentioned main shaft (11) after the above-mentioned bar B1 is released by the above-mentioned material feeding machine 20, and the above-mentioned bar B1 can be moved from the above-mentioned The advance position P1 retreats. The drive unit (31) moves the stopper 40. As shown in Figures 8 to 10, etc., the control unit (70) performs the following operations when the operation of cutting the workpiece W1 with the cutting knife TO3 is completed while the stopper 40 is retracted from the advanced position P1. The driving unit (31) controls the movement of the stopper 40 to the position (P3) between the bar B1 held by the main shaft (11) and the workpiece W1 held by the counter main shaft (16), When the torque generated by the drive unit (31) exceeds the reference torque for detecting the abutment of the stopper 40 on the bar B1, the processing of the breakage of the cutting knife TO3 is performed (for example, step S124 shown in FIG. 8 . processing).

The bar B1 pushed forward by the main shaft (11) of the feeder 20 is positioned by the stopper 40 present at the advance position P1. The front end B1a of the bar B1 protruding forward from the main shaft (11) is held by the opposing main shaft (16). If the cutting tool TO3 is not damaged, the workpiece W1 including the front end B1a of the bar B1 held by the opposing spindle (16) is cut from the bar B1. When the workpiece W1 is not cut from the bar B1, the cutting tool TO3 is broken. In this case, as shown in FIG. 10 , when the stopper 40 in the retracted state from the forward position P1 moves toward the gap between the bar B1 held by the main shaft (11) and the workpiece W1 held by the opposing main shaft (16). When the position (P3) side moves, it comes into contact with the bar B1. In this way, the torque generated by the drive unit (31) exceeds the reference torque, thereby performing processing for the breakage of the cutting blade TO3 (S124). Through the above, the breakage of the cutting knife TO3 can be detected by positioning the stopper 40 of the bar B1 pushed out from the main shaft (11) by the feeder 20 and the driving part (31) of the stopper 40 . Therefore, the above-mentioned aspect can provide a lathe that does not require a dedicated device for detecting breakage of the cutting blade. As a result, there is no need to arrange a space for a dedicated device for detecting breakage of the cutting blade, and the cost for the dedicated device is also eliminated.

Here, the position between the bar held by the main shaft and the workpiece held by the counter-spindle means the position between the bar and the work in a state where the work is cut from the bar. If the workpiece is not cut from the bar, the position where the stopper abuts against the bar (including the workpiece) may be the same position as the forward position or a different position from the forward position. The driving part that moves the stopper may be a driving part that moves the knife rest on which the cutting blade is mounted, or may be different from the driving part that moves the blade rest on which the cutting blade is mounted. The torque generated by the driving part is expressed by the current value flowing through the servo motor of the driving part that moves the stopper, the relative value of the current value flowing through the servo motor of the driving part, etc., and can also be output from the servo amplifier to the servo motor in the driving part Indicates the value of the torque command. The above postscript also applies to the following aspects.

[Form 2] As shown in FIGS. 5, 12 and the like, the above-mentioned stopper 40 can be attached to the tool post 30 on which the tool TO1 is attached. The said drive part (31) can also move the said stopper 40 by moving the said knife rest 30. This aspect can provide a kind of lathe, because it can move the stopper 40 by the driving part (31) of the tool rest 30, so there is no need for a dedicated driving part to move the stopper. Here, the knife holder on which the stopper is attached may be a knife holder on which a cutting knife is attached as shown in FIG. 5 etc., or may be different from the knife holder 30A on which a cutting knife is attached as shown in FIG. 12 .

(2) Specific examples of the composition of the lathe: FIG. 1 is a front view schematically illustrating the configuration of a lathe 1 equipped with a guide bush 14. As shown in FIG. FIG. 2 is a front view schematically illustrating the configuration of the lathe 1 with the guide bush 14 removed. Fig. 3 is a plan view schematically illustrating a state in which the bar material B1 is cut by the cutting blade TO3. FIG. 4 is a top view schematically illustrating the state in which the bar B1 is positioned by the stopper 40 . FIG. 5 schematically illustrates the tool holder 30 , the guide sleeve 14 and the bar B1 in a state where the stopper 40 is in the advanced position P1 . In FIG. 5 , the rod B1 is hatched for easy understanding of the display. In Figs. 6, 11, and 12, bar B1 is also shaded.

In FIGS. 1 to 5 etc., the symbol D81 shows the upward direction, the symbol D82 shows the downward direction, the symbol D83 shows the left direction, the symbol D84 shows the right direction, the symbol D85 shows the front direction, and the symbol D86 shows the deep direction. Note that these directions are based on the direction in which the lathe 1 shown in FIG. 1 is viewed. The control axes of the lathe 1 include an X axis indicated by "X", a Y axis indicated by "Y", and a Z axis indicated by "Z". The Z-axis direction is a horizontal direction along the main shaft centerline AX1 which becomes the rotation center of the bar B1. The X-axis direction is a horizontal direction perpendicular to the Z-axis. The Y-axis direction is a vertical direction perpendicular to the Z-axis. In addition, the Z-axis and the X-axis may not be orthogonal if they intersect, the Z-axis and the Y-axis may not be orthogonal, and the X-axis and the Y-axis may not be orthogonal. In addition, the drawing referred to in this specification shows only the example for explaining this technology, and does not limit this technology. The description of the positional relationship of each part is just an example. Therefore, reversing the left and right, or reversing the direction of rotation, etc. are also included in this technique. Identicalness in direction or position is not limited to exact agreement, but includes deviation from strict agreement due to errors.

Lathe 1 is an NC lathe that includes a front headstock 10 , a front headstock drive unit 13 , a back headstock 15 , a back headstock drive unit 18 , a support table 25 , a tool post 30 , a tool post drive unit 31 , and a stopper 40 , NC (Numerical Control) device 70 and the like. Here, the tool post driving unit 31 is an example of a driving unit that moves the stopper 40 , and the NC device 70 is an example of a control unit. The front spindle 11 is incorporated in the front spindle base 10 as an example of a spindle that can freely hold the bar B1 inserted from the rear by the material feeding machine 20 . The front end 11 a of the front main shaft 11 faces the rear main shaft 16 , and the rear end 11 b of the front main shaft 11 faces the material feeder 20 . The front main shaft 11 has a through hole 11h penetrating along the main shaft centerline AX1. The rod B1 is inserted into the through-hole 11h from the rear. In the back headstock 15, the back main shaft 16 is incorporated as an example of the facing main shaft which can releasably hold the front end B1a of the bar B1 protruding forward from the front end 11a of the front main shaft 11. The front end 16 a of the rear main shaft 16 faces the front end 11 a of the front main shaft 11 . That is, the front main shaft 11 and the back main shaft 16 face each other. In addition, the front relative to the front spindle 11 refers to the direction in which the bar B1 is pushed out from the front spindle 11, which is the right direction D84 in the example shown in FIG. 1 . The rear side relative to the front main shaft 11 means the direction from the front main shaft 11 to the material feeder 20 , which is the left direction D83 in the example shown in FIG. 1 . The front relative to the rear main shaft 16 means the direction in which the back main shaft 16 faces the front main shaft 11 side, which is the left direction D83 in the example shown in FIG. 1 . In the installation hole 26 of the supporting table 25, the guide sleeve 14 can be installed as shown in FIG. 1 , and can be inserted into the front part of the front main shaft 11 as shown in FIG. 2 . Therefore, the lathe 1 is a movable-spindle lathe that can switch between the presence and absence of the guide bush 14 .

The front main shaft 11 is equipped with a holding part 12 that can releasably hold the bar B1 at the part including the front end 11a, and the bar B1 can be releasably held by the holding part 12, and can be centered on the main shaft center line AX1 together with the bar B1 rotate. The NC device 70 controls the gripping state of the gripping unit 12 by driving the gripping actuator 12 a illustrated in FIG. 7 . The holding part 12 can be comprised by the chuck etc., for example. The NC device 70 controls the rotation of the front main shaft 11 by a servo motor not shown (for example, a built-in motor). The front headstock driving unit 13 moves the front headstock 10 incorporated in the front spindle 11 in the Z-axis direction according to the command from the NC device 70 .

The back spindle 16 is provided with a gripping portion 17 that can releasably grip the front end B1a of the bar B1 after front processing at the portion including the front end 16a, and the front end B1a of the bar B1 can be releasably gripped by the gripping portion 17, and can Together with the bar B1, it rotates around the spindle centerline AX1. The workpiece W1 to be a product is a portion including the front end portion B1a of the bar B1, that is, a portion cut out from the bar B1 by the cutting tool TO3. The NC device 70 controls the gripping state of the gripping unit 17 by driving the gripping actuator 17 a illustrated in FIG. 7 . The holding part 17 can be comprised by the chuck etc., for example. The NC device 70 controls the rotation of the back spindle 16 by a servo motor not shown (for example, a built-in motor). The back headstock driving unit 18 moves the back headstock 15 incorporated in the back spindle 16 in the Z-axis direction in accordance with commands from the NC device 70 . The back headstock driving unit 18 can also move the back headstock 15 incorporated in the back spindle 16 in at least one of the X-axis direction and the Y-axis direction. The workpiece W1 cut from the bar B1 becomes a product through back processing.

The material feeding machine 20 for supplying the bar material B1 to the front main shaft 11 includes, for example, an unshown rail along the main shaft centerline AX1, and a not-shown rail for moving the bar B1 on the rail to the front main shaft 11 side (right direction D84). The drive unit and the like shown insert the bar B1 into the through hole 11h of the front main shaft 11 from behind. For the material feeding machine 20, a finger-type bar supply device that holds a bar and feeds it into the front main shaft, a push-pull type bar supply device that only presses a bar from the rear and feeds it into the front main shaft, etc. can be used. The bar B1 is not limited to solid materials such as long cylindrical materials, and may also be hollow materials such as long cylindrical materials.

The support table 25 is located between the front headstock 10 and the back headstock 15 in the Z-axis direction, and has a mounting hole 26 penetrating in the Z-axis direction. When using the guide sleeve as shown in FIG. 1 , the guide sleeve 14 is inserted into the mounting hole 26 and detachably installed on the supporting platform 25 . The guide bush 14 supports the bar B1 protruding forward from the through hole 11h of the front spindle 11 to slide in the Z-axis direction. The part protruding from the guide bush 14 to the back spindle 16 side (rightward direction D84 ) of the bar B1 is processed by the tool TO1 . When the guide sleeve is not used as shown in FIG. 2 , the front part of the front main shaft 11 is inserted into the installation hole 26 . The part protruding forward (rightward direction D84) from the front spindle 11 in the bar B1 is machined by the tool TO1.

The tool post 30 is equipped with a plurality of tools TO1 for processing the bar B1, and can move in the X-axis direction and the Y-axis direction. The tool post driving unit 31 moves the tool post 30 in the X-axis direction and the Y-axis direction according to commands from the NC device 70 . The tool post driving unit 31 can also move the tool post 30 in the Z-axis direction. The knife rest 30 can be a comb-shaped knife rest as shown in FIG. 5 , or a hexagonal knife rest. The lathe 1 may also be provided with a tool holder for backside machining for machining the backside of the workpiece W1 held by the backside spindle 16 . A plurality of tools TO1 include a tool TO2 including a cutting tool TO3, a rotary tool such as a rotary drill or an end mill, and the like. The tool post 30 shown in FIG. 5 includes the cutting tool TO3 arranged at the lowermost part, and a plurality of tools TO2 are installed in a state protruding toward the spindle centerline AX1 side (depth direction D86). As shown in FIG. 3 , the cutting tool TO3 cuts the bar B1 between the front spindle 11 and the back spindle 16 , thereby cutting the workpiece W1 including the front end B1a of the bar B1 held by the back spindle 16 from the bar B1 .

Fig. 3 shows the condition that the cutting tool TO3 cuts the workpiece W1 from the bar B1 when the guide bush is not used. In FIG. 3 , "closed" of the gripping parts 12 and 17 shows that the gripping parts 12 and 17 are tightened by the gripping actuators 12 a and 17 a shown in FIG. 7 to grip the bar B1 . The state ST1 shown in FIG. 3 is a state in which the gripping portion 17 of the back spindle 16 grips the workpiece W1 including the front end B1a of the bar B1 while the gripping portion 12 of the front spindle 11 grips the bar B1. The NC device 70 performs control such that the front end TO3a of the cutting knife TO3 and the tool post 30 are placed between the front spindle 11 and the back spindle 16 while the front spindle 11 and the back spindle 16 holding the bar B1 are rotated. Move to the X-axis direction (depth direction D86) until the spindle center line AX1. This results in a state ST2 in which the bar B1 is cut between the front spindle 11 and the back spindle 16 , that is, a state ST2 in which the workpiece W1 held by the back spindle 16 is cut from the bar B1 .

In the knife holder 30 shown in FIG. 5 , a stopper 40 is installed with a screw SC1 on the upper side of the plurality of knives TO2 installed. The stopper 40 of this specific example is a member installed on the tool post 30 on which the cutting tool TO3 is installed, and can move in the X-axis direction and the Y-axis direction together with the tool post 30 . The stopper 40 is attached to the tool post 30 shown in FIG. 5 in a state protruding toward the spindle center line AX1 side (depth direction D86). As shown in FIG. 4 , the stopper 40 positions the bar B1 at the advance position P1 before the bar B1 pushed forward from the front spindle 11 of the liberated bar B1 by the feeder 20 abuts the bar B1, and can be moved from the forward position P1 retreat. The stopper 40 may be formed of, for example, metal, or may be formed of lightweight materials such as carbon or ceramics.

FIG. 4 shows the situation where the bar B1 is positioned by the stopper 40 when the guide sleeve is not used. In FIG. 4 , "opening" of the gripping part 12 indicates that the fastening of the gripping part 12 is released and the bar B1 is released from gripping. The state ST3 shown in FIG. 4 is a state in which the cutting tool TO3 retreats from between the workpiece W1 and the bar B1 and the gripping portion 12 of the front spindle 11 releases the bar B1 from gripping. Back processing is performed on the workpiece W1 held by the holding portion 17 of the back spindle 16 . In states ST4 and ST5 shown in FIG. 4 , the rear headstock 15 is not shown. The state ST4 shown in FIG. 4 is a state in which the front headstock 10 is retracted and the stopper 40 is advanced to the advanced position P1. The advancing position P1 only needs to be the position where the stopper 40 enters the range shown by the chain line of two dots in FIG. 4 . Even if the front spindle 11 frees the bar B1 from gripping, there is still friction between the front spindle 11 and the bar B1, whereby the bar B1 retreats to some extent when the front headstock 10 retreats. Since the receding degree of the bar B1 is not fixed, the positional relationship between the front spindle 11 and the bar B1 is not fixed. The state ST5 shown in FIG. 4 is that the front end B1a of the bar B1 is pushed forward from the front spindle 11 of the liberated bar B1 by the drive of the material feeding machine 20, and the front end B1a of the bar B1 abuts against the stopper 40 and is held by the front spindle 11 The part 12 grasps the state of the bar B1. Thereby, the bar B1 is positioned with respect to the front spindle 11, and the next front processing can be performed.

In addition, when the guide bush is used, the guide bush 14 holds the bar B1, so that the position of the bar B1 is fixed relative to the guide bush 14 even if the front spindle 11 that holds and releases the bar B1 retreats. Therefore, when using the guide sleeve, the stopper 40 does not need to be used. In this way, when the stopper 40 is not used for detecting the breakage of the cutter, it only has the function of opening the gripping portion 12 of the front spindle 11 to press against the bar B1 after cutting the bar when the guide sleeve is not used.

Incidentally, if the cutting tool TO3 is damaged, the workpiece W1 cannot be cut from the bar B1. Therefore, it is desired to detect breakage of the cutting blade TO3. However, in order to install a dedicated cutting blade damage detection device on the lathe 1, the lathe 1 needs a space for disposing the cutting blade damage detection device, and also consumes the cost for the cutting blade damage detection device. In this specific example, the stopper 40 for positioning the bar material B1 is used for the detection of the breakage of the cutting blade, and a dedicated device for detecting the breakage of the cutting blade TO3 is not required. Since the stopper 40 and the knife rest driving part 31 have both the function of pressing against the bar B1 and the function of detecting the breakage of the cutting knife, the effects of space saving and cost reduction are obtained. Hereinafter, detection of breakage of the cutting blade using the stopper 40 will be described.

FIG. 6 schematically illustrates the upper surface of the tool holder 30 on which the stopper 40 and the cutting tool TO3 are installed, the guide bush 14 and the bar B1. In the lower part of FIG. 6 , an enlarged view of the stopper 40 and the cutting knife TO3 is shown. As shown in FIG. 6 , at the part protruding from the tool holder 30 in the depth direction D86, the left side 40L of the stopper 40 is located about 1 to 2 mm to the right of the left side TO3L of the cutting knife TO3, and the stopper 40 The right side 40R is located on the left side of the right side TO3R of the cutting blade TO3. That is, in the Z-axis direction, the range of the protruding portion of the stopper 40 is within the range of the protruding portion of the cutting blade TO3, and is smaller than the range of the protruding portion of the cutting blade TO3. When the tool holder 30 does not move in the Z-axis direction, the stopper 40 is used for the detection of the breakage of the cutting knife. It is preferable that the range of the protruding part of the stopper 40 is within the range of the protruding part of the cutting knife TO3 Inside.

FIG. 7 schematically illustrates the configuration of an electrical circuit of a lathe 1 equipped with an NC device 70 . The NC device 70 is connected to the operation unit 80, the material feeder 20, the front headstock drive unit 13, the rotation drive unit (not shown) of the front main shaft 11, the gripping actuator 12a, the back headstock drive unit 18, The rotation driving part (not shown) of the back main shaft 16, the actuator 17a for grasping, the tool rest driving part 31, etc. are shown. The gripping actuator 12a drives the gripping portion 12 of the front spindle 11 shown in FIGS. 1 to 4 . The gripping actuator 17a drives the gripping portion 17 of the back spindle 16 shown in FIGS. 1 to 4 . The tool post drive unit 31 includes servo amplifiers 32 , 33 and servo motors 34 , 35 . The NC device 70 includes a CPU (Central Processing Unit: Central Processing Unit) 71 that is a processor, a ROM (Read Only Memory: Read Only Memory) 72 that is a semiconductor memory, and a RAM (Random Access Memory: Random Access Memory) that is a semiconductor memory. body) 73, a clock circuit 74, an I/F (Interface: interface) 75, and the like. In FIG. 7, the centralized operation unit 80, the material feeder 20, the front headstock drive unit 13, the holding actuator 12a, the back headstock drive unit 18, the holding actuator 17a, the tool post drive unit 31, etc. I/F is displayed as I/F75. In ROM72, control program PR1 for interpreting and executing processing program PR2 is written. The ROM 72 can also be a rewritable semiconductor memory. The processing formula PR2 created by the operator is rewritably stored in RAM 73 . Processing program is also called NC program. CPU71 uses RAM73 as a work area, and executes the control program PR1 recorded in ROM72, thereby realizing the function of NC device 70.

The operation unit 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 is constituted by, for example, buttons or a touch panel for receiving an operation input from an operator. The display unit 82 is constituted by, for example, a display that displays the contents of various settings received from an operator and various information related to the lathe 1 . The operator can use the operation unit 80 or an external computer (not shown) to store the processing formula PR2 in the RAM 73 .

The tool post drive unit 31 includes a servo amplifier 32 connected to the NC device 70 and a servo motor 34 connected to the servo amplifier 32 to move the tool post 30 along the X-axis. In addition, the tool post driving unit 31 includes a servo amplifier 33 connected to the NC device 70 and a servo motor 35 connected to the servo amplifier 33 in order to move the tool post 30 along the Y axis.

The servo amplifier 32 controls the position and moving speed of the tool post 30 in the X-axis direction according to the command from the NC device 70 . The servo amplifier 33 controls the position and moving speed of the tool post 30 in the Y-axis direction according to the command from the NC device 70 . The servo motor 34 is provided with an encoder 36, rotates according to the instruction|command from the servo amplifier 32, and moves the tool post 30 in the X-axis direction via the feed mechanism and guide which are not shown in figure. The servo motor 35 is provided with an encoder 37, rotates according to the instruction|command from the servo amplifier 33, and moves the tool post 30 in the Y-axis direction via the feed mechanism and guide which are not shown in figure. As the feed mechanism, a mechanism using a ball screw or the like can be used. For guides, sliding guides with a combination of dovetail tenon and dovetail tenon groove can be used.

(3) Specific examples of processing: FIG. 8 schematically illustrates the processing performed when the processing formula PR2 is executed. Machining is performed by the NC device 70 executing the control program PR1. As an initial state, the stopper 40 and the cutting blade TO3 are arranged so as not to interfere with the bar material B1. When the guide sleeve is not used, the NC device 70 first moves the tool rest driving part 31 to move the tool rest 30, so that the stopper 40 advances to the advance position P1 before the bar B1 pushed forward from the front spindle 11 abuts (step S102). For example, the NC device 70 can align the position of the front end 41 of the stopper 40 with the position of the spindle centerline AX1 in the Y-axis direction, and then move the stopper 40 to the forward position P1 in the X-axis direction. Next, the stopper 40 after the processing of step S102 exists in the advance position P1 shown in FIG. 4 (state ST4 ) and FIG. 5 . When using the guide bush, the process of advancing the stopper 40 is not performed.

After the processing in step S102, the NC device 70 is in a state where the gripping of the front spindle 11 is closed, that is, the bar B1 is supplied from the rear to the front spindle 11 in a state where the bar B1 is released from the grip of the gripping part 12. The feeding machine 20 is driven by inserting (step S104). In this way, as shown in the lower part of FIG. 4 (state ST5), the front end B1a of the bar B1 protruding forward from the front headstock 10 abuts against the stopper 40 to position the bar B1. When the front end B1a of the bar B1 is in contact with the stopper 40 for a sufficient time, the NC device 70 opens the grip of the front spindle 11 (step S106). That is, the NC device 70 causes the gripping unit 12 to grip the bar B1. This state is state ST5 shown in FIG. 4 . In this state ST5, the position of the bar B1 with respect to the front spindle 11 is fixed.

After the bar B1 is grasped, when the guide bush is not used, the NC device 70 moves the tool post 30 by the tool post driving unit 31, thereby retracting the stopper 40 from the advanced position P1 (step S108). For example, the NC device 70 can also move the stopper 40 in the X-axis direction from the advanced position P1 to a position where it does not interfere with the bar B1. When using the guide bush, the process of retracting the stopper 40 is not performed. After the processing in step S108, the NC device 70 makes the tool post driving unit 31 move the tool post 30 and the front headstock driving unit 13 moves the front headstock 10 as necessary to process the front side of the bar B1 (step S110) .

After processing the front side of the bar B1, the NC device 70 moves the back headstock driving part 18 to move the back headstock 15, so that the holding part 17 of the back spindle 16 holds the front end of the bar B1 protruding forward from the front headstock 10 B1a (step S112). This state is the state ST1 shown in FIG. 3 . After the front end B1a of the bar B1 is gripped by the back spindle 16, the NC device 70 rotates the front spindle 11 and the back spindle 16 at the same speed, and cuts off the bar B1 including the front end of the bar B1 by the cutting tool TO3. In the manner of the workpiece W1 of B1a, the tool post driver 31 is moved to the tool post 30 (step S114). In step S114, the cutting blade TO3 operates so as to cut the bar B1, that is, to cut the workpiece W1 from the bar B1. The state in which the operation of cutting the workpiece W1 by the cutting tool TO3 is completed is the state ST2 shown in FIG. 3 . The stopper 40 attached to the position different from the cutting blade 30 with respect to the blade holder 30 is the state retracted from the advancing position P1.

When the operation of cutting the workpiece W1 by the cutting tool TO3 is completed, the NC device 70 performs the following control, that is, the stopper 40 is moved to the front spindle 11 by moving the tool post 30 by the tool post driving part 31. The target position P3 between the gripped bar B1 and the workpiece W1 gripped by the back spindle 16 (step S116 ). For example, the NC device 70 can also keep the cutting tool TO3 away from the bar B1 in the X-axis direction, and align the position of the front end 41 of the stopper 40 with the position of the spindle centerline AX1 in the Y-axis direction (shown in FIG. 9 State ST6 shown), and then move the stopper 40 to the advanced position P1 in the X-axis direction. FIG. 9 schematically illustrates a state in which the stopper 40 advances to the target position P3 between the bar B1 and the workpiece W1 when cutting is completed. In state ST6, the stopper 40 is located at the retracted position P2 retracted from the advanced position P1. The target position P3 only needs to be the position where the stopper 40 enters the position between the bar B1 and the workpiece W1. As shown in FIG. , 5 shows the same position as the forward position P1.

When the workpiece W1 is cut from the bar B1 as shown in FIG. 9 , the stopper 40 does not contact the bar B1 and the stopper 40 reaches the target position P3 in a state ST7. If the cutting tool TO3 is damaged, the workpiece W1 cannot be normally cut from the bar B1. FIG. 10 schematically illustrates a state where the stopper 40 abuts against the bar B1 when the cutting blade is broken. FIG. 11 schematically illustrates the tool holder 30 in a state where the stopper 40 abuts against the bar B1 when the guide bush is used. The upper part of Fig. 10 shows a state ST8 in which the workpiece W1 held by the back spindle 16 is connected to the bar B1 after the cutting operation is completed. In this state ST8, when the stopper 40 moves to the target position P3, the stopper 40 abuts on the bar material B1 (state ST9). In this way, the torque generated by the tool post driving part 31, that is, the torque applied from the tool post driving part 31 to the tool post 30 on which the stopper 40 is installed is too large. It can be said that it is the same when using a guide bush as shown in FIG. 11 . Therefore, the torque value indicating the torque generated by the tool rest driving part 31 is taken as TR1, and if the torque value TR1 is greater than the reference torque value TR2 indicating the reference torque for detecting that the stopper 40 abuts against the bar B1, then it can be judged that the tool has been cut. The broken knife TO3 is broken.

After starting the control to advance the stopper 40 to the advance position P1, the NC device 70 obtains from the servo amplifier 32 a torque value TR1 indicating the torque generated by the servo amplifier 32 for the X axis, until the stopper 40 reaches the target position P3 The processing branches depending on whether the torque stop value TR1 exceeds the reference torque value TR2 (step S118). It can be said that the process of step S118 is a process of judging whether the torque generated by the tool post driving unit 31 exceeds the reference torque for detecting the contact of the stopper 40 to the bar B1. When the stopper 40 advances, the servo amplifier 32 outputs a torque command including a torque value TR1 to the servo motor 34, and the servo motor 34 moves the tool post 30 according to the torque command. When receiving an output command of a torque value from the NC device 70 , the servo amplifier 32 outputs the torque value TR1 included in the torque command to the NC device 70 . Thereby, the NC device 70 can obtain the torque value TR1 from the servo amplifier 32 .

As shown in FIG. 9 , when the workpiece W1 is cut from the bar B1, the torque value TR1 does not exceed the reference torque value TR2 until the stopper 40 reaches the target position P3. In this case, the NC device 70 starts machining of the back surface of the workpiece W1 (step S120). During back machining, the NC device 70 moves the tool post driving unit 31 to move the tool post 30 , and moves the back headstock driving unit 18 to move the back headstock 15 to perform back machining. In addition, when the lathe 1 has a tool post for back processing in addition to the tool post 30 on which the stopper 40 is installed, the NC device 70 can also perform control of back processing by moving the tool post for back processing. . In this case, the NC device 70 may leave the stopper 40 at the target position P3, or may move the stopper 40 from the target position P3 to the forward position P1 when the forward position P1 is different from the target position P3. Thereby, while processing the back surface of the workpiece W1, it is possible to perform front processing of the bar B1 which is the next workpiece W1.

After the processing of step S120, the NC device 70 branches the processing according to whether or not the continuous processing of the bar B1 is completed (step S122). When the cutting blade TO3 is not damaged, the processing of steps S102 to S122 is processing for one machining cycle. When the continuous machining ends, the NC device 70 ends the machining process. When performing the processing of the next machining cycle, the NC device 70 returns the processing to step S102. Thereby, when the guide bush is not used, the stopper 40 advances toward the advance position P1 before the bar B1 pushed forward from the front main shaft 11 abuts against in step S102. Afterwards, the grip of the front main shaft 11 is turned off and the front headstock 10 moves backward (state ST4 shown in FIG. 4 ), and the bar B1 pushed forward from the front main shaft 11 abuts against the stopper 40 and pushes the front headstock 10 forward. The main shaft 11 is gripped open (state ST5 shown in FIG. 4 ), and the stopper 40 retreats from the advanced position P1 when the guide bush is not used. Afterwards, front processing is performed, and the front end B1a of the bar B1 is gripped by the back spindle 16 (state ST1 shown in FIG. 3 ), the cutting operation is performed, and the stopper 40 moves to the target position P3.

When the workpiece W1 is not cut from the bar B1 as shown in FIG. 10 , the stopper 40 is in a state ST9 in contact with the bar B1, and the torque value TR1 exceeds the reference torque value TR2. In this case, the NC device 70 outputs a warning indicating that the cutting tool TO3 is broken, and stops the processing (step S124). The processing of step S124 is an example of the processing in the case where the cutting blade TO3 is broken. The process of outputting a warning can be a process of displaying a warning on the display unit 82 , a process of outputting a warning sound from a speaker not shown in the figure, a process of outputting a warning to a computer connected to the NC device 70 , and the like. In this case, the operator restarts the continuous processing of the bar material B1 by replacing the broken cutting blade with an unbroken cutting blade.

As described above, the breakage of the cutting tool TO3 can be detected by the stopper 40 for positioning the bar B1 pushed out from the front spindle 11 by the material feeder 20 and the tool rest driving part 31 for moving the stopper 40 . Thereby, there is no need to add special parts or functions for detecting breakage of the cutting blade. Therefore, this specific example does not require a special device for detecting the breakage of the cutting blade, does not require a space for a dedicated detection device for the damage of the cutting blade, and does not need the cost for a dedicated detection device for the damage of the cutting blade.

(4) Variation example: Various modifications are conceivable for the present invention. For example, the moving direction of the stopper 40 when it reaches the advancing position P1 is not limited to the X-axis direction, and may be various directions intersecting the Z-axis direction, such as the Y-axis direction. The moving direction of the stopper 40 when it reaches the target position P3 is not limited to the X-axis direction, and may be any direction intersecting the Z-axis direction, such as the Y-axis direction. The above-mentioned processing can be modified appropriately, such as changing the order. For example, the process of advancing the stopper 40 to the advanced position P1 in S102 may be performed after the bar supply process in S104 is started as long as the front end B1a of the bar B1 reaches in the Z-axis direction.

As shown in FIG. 12, the tool holder 40 mounted with the stopper 40 may be different from the tool holder 30A equipped with the cutting blade TO3. The tool holder 30 shown in FIG. 12 includes a tool holder 30A installed in a state where a plurality of tools TO2 including the cutting tool TO3 protrude toward the depth direction D86, and a plurality of tools TO1 are installed in a state where the plurality of tools TO1 protrude in the near direction D85. The knife holder 30B. The stopper 40 is attached to the tool post 30B to which the cutting tool TO3 is not attached. The tool post 30A is movable in the X-axis direction and the Y-axis direction by the tool post drive unit 31A. The tool post 30B is movable in the X-axis direction and the Y-axis direction by the tool post drive unit 31B. The tool holders 30A, 30B can move independently of each other at least in the X-axis direction.

When the NC apparatus 70 positions the bar material B1 by the stopper 40, what is necessary is just to perform the control which advances the stopper 40 to advance position P1 (refer FIG. 4) by moving the tool post 30B. When the NC device 70 cuts the bar material B1 with the cutting blade TO3, it is only necessary to perform control to move the tool post 30A. When the NC device 70 detects breakage of the cutting tool TO3 by the stopper 40, it is only necessary to perform control to advance the stopper 40 to the target position P3 (see FIG. 9 ) by moving the tool rest 30B. The example shown in FIG. 12 also does not require a special device for detecting the breakage of the cutting blade, does not require a space for a dedicated detection device for the damage of the cutting blade, and does not need to be used for the cost of a dedicated detection device for the damage of the cutting blade.

(5) Summary: As described above, according to the present invention, it is possible to provide technology such as a lathe that does not require a dedicated device for detecting breakage of the cutting blade through various aspects. Of course, the above-mentioned basic functions and effects can also be obtained in the technology including only the constituent elements of the independent claims. In addition, it is also possible to replace the respective structures disclosed in the above examples or the structures of modified combinations, to replace known techniques with each other or the structures disclosed in the above examples. The present invention also includes these constitutions and the like.

1: lathe 10: Front headstock 11: Front spindle (example of spindle) 11a: front end 11b: Backend 11h: Through hole 12: Control Department 12a: Actuator for handling 13: Front headstock drive unit 14: guide sleeve 15: Rear headstock 16: Rear spindle (example of opposite spindle) 16a: front end 17: Control Department 17a: Actuator for handling 18: Back headstock drive unit 20: Material supply machine 25: Support Desk 26: Mounting hole 30: knife holder 30A: knife holder 30B: knife holder 31: Tool holder driving part (example of driving part) 31A: Knife post driving part 31B: Knife post driving part 32: Servo amplifier 33: Servo amplifier 34:Servo motor 35:Servo motor 36: Encoder 37: Encoder 40: stopper 40L: left side 40R: right side 41: front end 70: NC device (example of control unit) 71:CPU 72: ROM 73: RAM 74: Clock circuit 75:I/F 80:Operation Department 81: input part 82: Display part AX1: spindle centerline B1: bar B1a: front end D81: up direction D82: down direction D83: left direction D84: right direction D85: near front direction D86: Depth direction P1: forward position P2: retreat position P3: target position PR1: Control Program PR2: Processing formula S102～S124: Steps SC1: screw ST1～ST9: Status TO1: Tools TO2: Knife TO3: cutting knife TO3a: front end TO3L: left side TO3R: right side TR1: Torque value TR2: Reference torque value W1: Workpiece

Fig. 1 is a front view schematically showing a configuration example of a lathe equipped with a guide bush. Fig. 2 is a front view schematically showing a configuration example of a lathe with a guide bush removed. Fig. 3 is a plan view schematically showing an example of cutting a rod by a cutting blade. Fig. 4 is a top view schematically showing an example of a stopper positioning bar. Fig. 5 is a view schematically showing an example of the tool holder in the state where the stopper is in the advanced position. Fig. 6 is a top view schematically showing an example of a tool holder with a stopper installed. Fig. 7 is a block diagram schematically showing a configuration example of an electrical circuit of a lathe. Fig. 8 is a flowchart schematically showing an example of processing. Fig. 9 is a plan view schematically showing an example in which the stopper advances to the target position between the bar and the workpiece when cutting is completed. Fig. 10 is a plan view schematically showing an example in which the stopper abuts against the bar when the cutting blade is broken. Fig. 11 is a diagram schematically showing an example of the tool holder in a state where the stopper is in contact with the bar. Fig. 12 is a diagram schematically showing another example of the tool holder on which the stopper is installed.

10: Front headstock

11: Front spindle (example of spindle)

11a: front end

11b: Backend

12: Control Department

15: Rear headstock

16: Rear spindle (example of opposite spindle)

17: Control Department

20: Material supply machine

30: knife holder

40: stopper

AX1: spindle centerline

B1: bar

B1a: front end

D83: left direction

D84: right direction

D85: near front direction

D86: Depth direction

P2: retreat position

P3: target position

ST8: Status

ST9: Status

W1: Workpiece

Claims (2)

A lathe, which is a lathe for processing bars supplied by a material supply machine, and has: The main shaft, which can freely hold the above-mentioned bar inserted from the rear; facing the main shaft, which can freely hold the front end of the above-mentioned bar protruding forward from the above-mentioned main shaft; A knife holder, which is equipped with a cutting knife for cutting the workpiece including the front end of the above-mentioned bar held by the opposing spindle from the above-mentioned bar; The stopper is used to position the bar at the advanced position before the bar is pushed forward by the main shaft after the bar is released by the material feeding machine, and can retreat from the advanced position; a driving part which moves the above-mentioned stopper; and A control unit for moving the stopper to the position held by the main shaft by the driving unit when the operation of cutting the workpiece with the cutting knife is completed while the stopper is retracted from the advanced position. The control of the position between the above-mentioned bar and the above-mentioned workpiece grasped by the above-mentioned counter-spindle is performed when the torque generated by the above-mentioned drive part exceeds the reference torque for detecting whether the above-mentioned stopper is in contact with the above-mentioned bar. Handling of broken knives. As the lathe of claim 1, wherein the above-mentioned stopper is installed on the tool holder on which the tool is installed, The drive unit moves the stopper by moving the tool post.

Images