JP7553766B2 - lathe - Google Patents

Description

The present invention relates to a lathe that uses a tool to machine a workpiece held by a spindle.

An NC (numerically controlled) lathe is equipped with a headstock with a spindle that grips a workpiece, a tool rest to which a tool is attached either directly or via a tool holder, and a drive unit that moves at least one of the driven objects, the headstock or the tool rest. In addition, to prevent the driven object from interfering with other structures, the NC lathe controls the drive unit so that the driven object does not enter a no-entry area set in the structure. For example, if the driven object is the headstock, the movement of the headstock is controlled so that the spindle does not enter a no-entry area set in the tool rest.

To improve the machining accuracy of a workpiece, it is preferable to attach a tool to the tool rest or tool holder so that the length of the tool protruding from the tool rest or tool holder is as short as possible. However, the shorter the protruding length of the tool is, the closer the spindle and tool rest must be, and the more likely it is that the spindle and tool rest cannot be brought closer due to a no-entry area. The numerical control device disclosed in Patent Document 1 simulates a machining program, and if interference occurs between the tool or tool holder and another structure, it changes the tool or tool holder and repeats the simulation of the machining program again.

JP 2012-218111 A

However, repeating a simulation of a machining program requires time-consuming and cumbersome work.
The present invention discloses a lathe that allows the projection length of a tool to be easily adjusted without performing a simulation.

The lathe of the present invention comprises: a headstock having a spindle for gripping a workpiece;
a tool rest portion to which a tool for machining the workpiece held by the spindle can be attached;
a drive unit that moves at least one of the headstock and the tool rest in a drive axis direction in which a distance from the workpiece to the tool changes;
A storage unit that stores entry-prohibited area information that indicates an entry-prohibited area of the driving object;
a distance display unit that calculates and displays a distance from the driven object to the no-entry area in the drive axis direction based on a current position of the driven object in the drive axis direction and the no-entry area information;
a tool position information display unit that displays tool position information representing a position of the tool in the drive shaft direction ,
The tool position information display unit has a configuration in which, when a setting key for acquiring the position where the workpiece and the tool contact in the drive shaft direction is operated while the spindle is gripping the workpiece, the tool position information display unit acquires the position where the workpiece and the tool contact in the drive shaft direction, and updates and displays the tool position information based on the acquired position .
The lathe of the present invention further comprises a headstock having a spindle for gripping a workpiece;
a tool rest portion to which a tool for machining the workpiece held by the spindle can be attached;
a drive unit that moves at least one of the headstock and the tool rest in a drive axis direction in which a distance from the workpiece to the tool changes;
A storage unit that stores entry-prohibited area information that indicates an entry-prohibited area of the driving object;
a distance display unit that calculates and displays a distance from the driven object to the no-entry area in the drive axis direction based on a current position of the driven object in the drive axis direction and the no-entry area information;
a tool position information display unit that displays tool position information representing a position of the tool in the drive shaft direction,
The tool position information display unit has a configuration in which, when a setting key for acquiring the position where the spindle and the tool contact in the drive shaft direction is operated while the spindle is not gripping the workpiece, the tool position information display unit acquires the position where the spindle and the tool contact in the drive shaft direction, and updates and displays the tool position information based on the acquired position.
Furthermore, the lathe of the present invention includes a headstock having a spindle for gripping a workpiece;
a tool rest portion to which a tool for machining the workpiece held by the spindle can be attached;
a drive unit that moves at least one of the headstock and the tool rest in a drive axis direction in which a distance from the workpiece to the tool changes;
A storage unit that stores entry-prohibited area information that indicates an entry-prohibited area of the driving object;
a distance display unit that calculates and displays a distance from the driven object to the no-entry area in the drive axis direction based on a current position of the driven object in the drive axis direction and the no-entry area information;
a mode reception unit that receives either a gripping mode in which the spindle grips the workpiece or a non-grip mode in which the spindle does not grip the workpiece;
a tool position information display unit that displays tool position information representing a position of the tool in the drive shaft direction,
The tool position information display unit includes:
When the mode is the gripping mode, when a setting key for acquiring a contact position between the workpiece and the tool in the drive shaft direction is operated in a state in which the spindle is gripping the workpiece, the contact position between the workpiece and the tool in the drive shaft direction is acquired, and the tool position information is updated and displayed based on the acquired position;
When the mode is the non-gripping mode, when the spindle is not gripping the workpiece and a setting key for acquiring the position where the spindle and the tool contact in the drive axis direction is operated, the position where the spindle and the tool contact in the drive axis direction is acquired, and the tool position information is updated and displayed based on the acquired position.

The present invention provides a lathe that allows the tool protrusion length to be easily adjusted without the need for simulation.

FIG. 2 is a plan view showing a schematic configuration example of a lathe. FIG. 2 is a block diagram illustrating a schematic configuration example of an electric circuit of a lathe. FIG. 2 is a front view illustrating a schematic example of an operation panel. FIG. 11 is a plan view showing a schematic example of a no-entry area and various parameters. FIG. 11 is a plan view showing an example of various parameters according to the position of a driven object. 13 is a flowchart showing an example of a tool mounting assist process performed on a lathe. FIG. 13 is a diagram illustrating an example of a tool selection screen in a grip mode. 13 is a diagram illustrating an example of a tool selection screen in a non-gripping mode. FIG. FIG. 13 is a diagram illustrating an example of a tool selection screen having a handle key. FIG. 13 is a diagram illustrating an example of a handle mode screen. FIG. 13 is a diagram illustrating an example of an updated screen including shape correction G. FIG. 13 is a plan view showing a schematic diagram of a modified example in which the main tool rest is the driving target. FIG. 13 is a plan view showing a schematic example of a lathe immediately after a temporary fixing operation of a target tool is performed. 11 is a plan view showing a schematic example of contacting an end face of a workpiece with a tip of a target tool. FIG. FIG. 11 is a plan view showing a schematic example of an example in which the back headstock advances until the machine coordinate Pm reaches the no-entry position Pa.

The following describes embodiments of the present invention. Of course, the following embodiments are merely examples of the present invention, and not all of the features shown in the embodiments are necessarily essential to the solution of the invention.

(1) Overview of the technology included in the present invention:
First, an overview of the technology included in the present invention will be described with reference to the examples shown in Figures 1 to 15. Note that the figures in this application are diagrams showing examples in a schematic manner, and the magnification ratios in each direction shown in these figures may differ, and the figures may not be consistent with each other. Of course, each element of the present technology is not limited to the specific example shown by the symbol.

[Aspect 1]
A lathe 1 according to an aspect of the present technology includes a headstock 10, a tool rest unit U1, a drive unit U2, a memory unit U3, and a distance display unit U4. The headstock 10 is provided with a spindle 11 for gripping a workpiece W1. A tool T1 for machining the workpiece W1 gripped by the spindle 11 can be attached to the tool rest unit U1. The drive unit U2 moves at least one of the driven objects 50 of the headstock 10 and the tool rest unit U1 in a drive axis direction 3 in which a distance from the workpiece W1 to the tool T1 (for example, O1-F shown in FIG. 4) changes. The memory unit U3 stores entry-prohibited area information IN1 representing an entry-prohibited area A1 of the driven object 50. As illustrated in Figures 6 and 10, the distance display unit U4 calculates and displays the distance Lot that the driven object 50 reaches the no-entry area A1 in the drive shaft direction 3 based on the current position (e.g., machine coordinates Pm) of the driven object 50 in the drive shaft direction 3 and the no-entry area information IN1.

In the above embodiment, the distance Lot from the driven object 50 to the no-entry area A1 in the drive shaft direction 3 is known numerically, so that the operator can adjust the protruding length Lt of the tool T1 based on a specific value of the distance Lot. Therefore, the above embodiment can provide a lathe that allows the protruding length of the tool to be easily adjusted without performing a simulation.
The no-entry area refers to an area in which the amount of movement is limited to prevent interference, and an area in which movement is not possible due to mechanical factors such as the length of the ball screw.

Here, the tool rest portion may be a combination of a tool rest and a tool holder when the tool is attached to the tool rest via a tool holder, or may be a tool rest alone when the tool is attached directly to the tool rest, such as a comb-shaped tool rest.
The driven object may be the headstock, the tool rest section, or both the headstock and the tool rest section. In other words, the drive section may move the headstock without moving the tool rest section, may move the tool rest section without moving the headstock, or may move both the headstock and the tool rest section.
The above remarks also apply to the following aspects.

[Aspect 2]
4, the tool rest U1 may be capable of mounting a plurality of the tools T1 at different positions on a virtual plane 4 intersecting with the drive shaft direction 3. The lathe 1 may further include a switching drive unit U5 (for example, the X2-axis motor M4 shown in FIG. 2) that switches the tool T1 for machining the workpiece W1 from among the plurality of tools T1 mounted on the tool rest U1.
The above embodiment allows for the use of multiple tools.

[Aspect 3]
The lathe 1 may further include a target tool receiving unit U6 (for example, an input unit 81 shown in FIG. 2) that receives a selection of a target tool T2, the protrusion length of which is to be adjusted, from among the plurality of tools T1 attached to the tool rest unit U1. The distance display unit U4 may calculate and display a distance Lot to the no-entry area A1 based on the current position (Pm) and the no-entry area information IN1 when the target tool T2 faces the workpiece W1 in the drive shaft direction 3.
In the above embodiment, since the distance Lot in the drive shaft direction 3 from the driven object 50 to the no-entry area A1 for each of the multiple tools T1 attached to the tool rest U1 is known numerically, the operator can adjust the protruding length Lt of the multiple tools T1 based on an appropriate specific value of the distance Lo to the no-entry area A1. Therefore, the above embodiment can provide a lathe that can easily adjust the protruding length of the multiple tools attached to the tool rest.

Here, the switching drive unit may switch tools by moving the headstock, may switch tools by moving the tool rest unit, or may switch tools by moving both the headstock and the tool rest unit. Also, if the tool rest unit includes a turret tool rest, the switching drive unit may switch tools by rotating the tool rest unit.
The above remarks also apply to the following aspects.

[Aspect 4]
As illustrated in Fig. 7 and the like, the lathe 1 may include a mode receiving unit U7 that receives either one of a gripping mode 521 in which the spindle 11 grips the workpiece W1 and a non-grip mode 522 in which the spindle 11 does not grip the workpiece W1. As illustrated in Fig. 11 and the like, the lathe 1 may further include a tool position information display unit U8 that displays tool position information IN2 that represents the position (e.g., shape correction G) of the tool T1 in the drive shaft direction 3. When the mode is the gripping mode 521, the tool position information display unit U8 may acquire a position (e.g., workpiece coordinate Pw in the contact state ST2 shown in Fig. 5) where the workpiece W1 and the tool T1 contact each other in the drive shaft direction 3 in a state in which the spindle 11 grips the workpiece W1, and display the tool position information IN2 based on the acquired position. In addition, when the mode is the non-gripping mode 522, the tool position information display unit U8 may acquire the position where the spindle 11 and the tool T1 contact each other in the drive shaft direction 3 when the spindle 11 is not gripping the workpiece W1, and display the tool position information IN2 based on the acquired position.

In the above embodiment, the attachment position (G) of the tool T1 can be determined numerically whether the spindle 11 is gripping the workpiece W1 or not, making it possible to provide a lathe that allows for even easier adjustment of the protruding length of the tool attached to the tool rest.

[Aspect 5]
The tool position information display unit U8 may receive an input of a machining length (e.g., end chamfering allowance F shown in FIG. 7) for machining the end face W1a of the workpiece W1 in the drive shaft direction 3. When the mode is the gripping mode 521, the tool position information display unit U8 may update the tool position information IN2 based on the acquired position (Pw) and the machining length (F). When the mode is the non-grip mode 522, the tool position information display unit U8 may update the tool position information IN2 without using the machining length (F).

In the above embodiment, the machining length (F) of the end face W1a of the workpiece W1 is taken into account in the position (G) of the tool T1, so a lathe can be provided that makes it even easier to adjust the protruding length of the tool attached to the tool rest.

(2) Specific examples of lathe configurations:
Fig. 1 shows a schematic configuration of a spindle-moving type NC (numerically controlled) lathe 1 as an example of a lathe. Fig. 2 shows a schematic configuration of an electric circuit of the NC lathe 1. Note that the explanation of the positional relationship of each part is merely an example. Therefore, the present technology also includes changing the left-right direction to the up-down direction or the front-back direction, changing the up-down direction to the left-right direction or the front-back direction, changing the front-back direction to the left-right direction or the up-down direction, changing the rotation direction to the opposite direction, etc. Also, the identity of the direction, position, etc. is not limited to strict agreement, but includes deviation from strict agreement due to an error.

The lathe 1 shown in FIG. 1 is equipped with a headstock 10, a guide bush 15, a support table 30, a tool rest 40, an NC device 70, etc., on a base 2. Here, the headstock 10 collectively refers to the front headstock 10A and the back headstock 10B, and the tool rest 40 collectively refers to the main tool rest 40A and the back tool rest 40B. The NC device 70 controls the operation of the headstock 10 and its drive unit (for example, the Z1-axis motor M1, the X2-axis motor M4, and the Z2-axis motor M5 shown in FIG. 2), the main tool rest 40A and its drive unit (for example, the X1-axis motor M2 and the Y1-axis motor M3 shown in FIG. 2), etc. The lathe 1 has the X1, Y1, Z1, X2, and Z2 axes as control axes. The Y1 axis is oriented perpendicular to the paper surface in FIG. 1. The X1, Y1, Z1, X2, and Z2 axis directions refer to directions along the X1, Y1, Z1, X2, and Z2 axes. Of course, the lathe 1 may have a control axis such as the Y2 axis in addition to the five axes mentioned above.

The front headstock 10A, which is provided with the front spindle 11A, is movable in the Z1-axis direction along the center line AX1 of the front spindle 11A relative to the base 2. The front spindle is also called the main spindle, and the front spindle stock is also called the main spindle stock. The NC device 70 controls the position of the front spindle stock 10A in the Z1-axis direction via the Z1-axis motor M1 and the feed mechanism 10z. The front spindle 11A releasably grips the cylindrical (rod-shaped) workpiece W1 inserted in the Z1-axis direction with a collet (not shown), and rotates the workpiece W1 around the center line AX1 along the longitudinal direction of the workpiece W1.

The guide bush 15 is attached to a support stand 30 located in front of the front spindle 11A. The guide bush 15, located in front of the front spindle 11A, supports the elongated workpiece W1 that passes through the front spindle 11A so that it can slide in the Z1 axis direction, and is driven to rotate around the center line AX1 of the front spindle 11A in synchronization with the front spindle 11A. In other words, the guide bush 15 supports the workpiece W1 through the workpiece W1 that protrudes from the front spindle 11A. The presence of the guide bush 15 suppresses bending of the elongated workpiece W1, allowing for high-precision machining.

The back spindle table 10B, which is provided with the back spindle 11B, is movable relative to the base 2 in the Z2 axis direction along the center line AX2 of the back spindle 11B, and in the X2 axis direction perpendicular to the center line AX2. The back spindle is also called the sub-spindle, and the back spindle table is also called the sub-spindle table. The Z2 axis direction is along the Z1 axis direction. The back spindle 11B is located opposite the front spindle 11A via the guide bush 15. The NC device 70 controls the position of the back spindle table 10B in the Z2 axis direction via the Z2 axis motor M5 and the feed mechanism 20z, and controls the position of the back spindle table 10B in the X2 axis direction via the X2 axis motor M4 and the feed mechanism 20x. The back spindle 11B receives the workpiece W1 from the front spindle 11A at a position opposite the front spindle 11A via the guide bush 15, and releasably holds the workpiece W1 inserted in the Z2 axis direction with a collet (not shown). For example, when the front-machined workpiece W1 is separated from the long workpiece by a cut-off bit held on the main tool rest 40A, the back spindle 11B rotates the front-machined workpiece W1 around a center line AX2 along the longitudinal direction of the front-machined workpiece W1.

The main tool rest 40A is a comb-shaped tool rest to which a plurality of tools T1 such as cutting tools are directly attached, and a tool such as a rotary drill may be attached via a tool holder. The main tool rest 40A is supported on the side portion 31 facing the back spindle 11B in the support base 30 so as to be movable in the X1 and Y1 axis directions perpendicular to the center line AX1 of the front spindle 11A. The X1 axis direction is along the X2 axis direction and perpendicular to the Z1 axis direction. The Y1 axis direction is perpendicular to the Z1 axis direction and the X1 axis direction. The NC device 70 controls the position of the main tool rest 40A in the X1 axis direction via the X1 axis motor M2 and the feed mechanism 40x, and controls the position of the main tool rest 40A in the Y1 axis direction via the Y1 axis motor M3 and the feed mechanism 40y. The main tool rest 40A is an example of a tool rest part U1 to which a tool T1 for machining the workpiece W1 held by the spindle 11 can be attached.

The support table 30 is fixed between the front spindle stock 10A and the rear spindle stock 10B so as not to move relative to the base 2, and extends upward from the base 2 in the X1 axis direction. The support table 30 holds a guide bush 15 through which the workpiece W1 protruding from the front spindle 11A passes. The side portion 31 of the support table 30 facing the rear spindle 11B supports the main tool rest 40A so that it can be moved in the X1 and Y1 axis directions, and fixes the attached back tool rest 40B so that it cannot move.

A plurality of tools T1, such as drill tools, are attached to the back tool rest 40B fixed to the support base 30 via tool holders TU1. By moving the back spindle stock 10B, which is provided with the back spindle 11B gripping the workpiece W1, in the X2 axis direction, it is possible to make any one of the plurality of tools T1 attached to the back tool rest 40B face the workpiece W1. The combination of the back tool rest 40B and the plurality of tool holders TU1 is an example of a tool rest section U1 to which a tool T1 for machining the workpiece W1 gripped by the spindle 11 can be attached.
In addition, the lathe 1 may be provided with tool rests other than the main tool rest 40A and the back tool rest 40B.

The headstock 10, guide bush 15, support table 30, tool rest 40, and main parts of the tool T1 can be made of, for example, metal.

In the lathe 1 shown in FIG. 2, the NC device 70 is connected to an operation panel 80, a Z1-axis motor M1, an X1-axis motor M2, a Y1-axis motor M3, an X2-axis motor M4, a Z2-axis motor M5, a rotary motor for the front spindle 11A (not shown), a rotary motor for the back spindle 11B (not shown), a rotary motor for the rotary drill (not shown), and the like. The NC device 70 has a CPU (Central Processing Unit) 71, a ROM (Read Only Memory) 72 which is a semiconductor memory, a RAM (Random Access Memory) 73 which is a semiconductor memory, a timer circuit 74, an I/F (interface) 75, and the like. In FIG. 2, the I/Fs for the operation panel 80 and the servo motors (M1 to M5) are collectively referred to as I/F 75.

The ROM 72 is written with an interpretation execution program P1 for interpreting and executing the machining program P2, and entry-prohibited area information IN1 representing the entry-prohibited area of the driven object. The ROM 72 is an example of a storage unit U3 that stores the entry-prohibited area information IN1. The ROM 72 may include a rewritable non-volatile memory such as a flash memory. If the entry-prohibited area information IN1 is written in the rewritable non-volatile memory, the entry-prohibited area information IN1 can be updated as appropriate. The RAM 73 stores a machining program P2 created by a user. The machining program is also called an NC program. The CPU 71 uses the RAM 73 as a work area and executes the interpretation execution program P1 recorded in the ROM 72 to cause the computer to function as an NC device 70. Of course, some or all of the functions realized by the interpretation execution program P1 may be realized by other means such as an ASIC (Application Specific Integrated Circuit).

The Z1-axis motor M1 moves the front headstock 10A including the front headstock 11A in both directions along the Z1-axis via the feed mechanism 10z shown in FIG. 1. The X1-axis motor M2 moves the main tool rest 40A in both directions along the X1-axis via the feed mechanism 40x shown in FIG. 1. The Y1-axis motor M3 moves the main tool rest 40A in both directions along the Y1-axis via the feed mechanism 40y shown in FIG. 1. The X2-axis motor M4 moves the back headstock 10B in both directions along the X2-axis via the feed mechanism 20x shown in FIG. 1. The Z2-axis motor M5 moves the back headstock 10B in both directions along the Z2-axis via the feed mechanism 20z shown in FIG. 1. The feed mechanisms 10z, 40x, 40y, 20x, and 20z can be a slidable fitting structure between a rail and a guide member, a slidable fitting structure between a dovetail groove and a dovetail, or the like.

FIG. 3 illustrates a schematic front view of the operation panel 80. As shown in FIG.
The operation panel 80 includes an input unit 81 and a display unit 82 , and functions as a user interface for the NC device 70 .

The input unit 81 is composed of hard keys 81a, a changeover switch 81b, a handle 83, buttons 84, and a touch panel (screen 82a of the display unit 82) for receiving operation input from the operator. The hard keys 81a include a control axis key 81c for selecting a control axis for manual handle feed from multiple control axes, a cursor key 81d for moving the cursor on the screen 82a, a character key 81e for typing characters such as alphabets and numbers, and an input key 81f for inputting typed characters. The changeover switch 81b is an operation unit for switching various operations, such as switching between discharging cutting oil and stopping the discharge. The handle 83 is an operation unit for manually moving the driven object. The buttons 84 include a START button used to select a target tool for adjusting the protrusion length. The screen 82a is provided with soft keys 81g as the input unit 81. The input unit 81 is an example of a target tool reception unit U6 that receives a selection of a target tool for which the protrusion length is to be adjusted from among the multiple tools T1 attached to the tool rest unit U1, and a mode reception unit U7 that receives either the G132 mode or the G130 mode (see Figures 7 to 11). The G132 mode is an example of a grip mode 521 in which the spindle 11 grips the workpiece W1. The G130 mode is an example of a non-grip mode 522 in which the spindle 11 does not grip the workpiece W1.

The display unit 82 is composed of a display (e.g., a liquid crystal display) that displays on a screen 82a the contents of various settings that have been input by the operator and various information related to the NC lathe 1. The screen 82a includes a tool selection screen 500, a handle mode screen 501, an update screen 502, and the like, which are shown in Figs. 7 to 11. The display unit 82 is an example of a distance display unit U4 (see Fig. 10) that calculates and displays the distance in the drive shaft direction until the driven object reaches the no-entry area, and a tool position information display unit U8 that displays tool position information that indicates the position of the tool T1 in the drive shaft direction.

Figure 4 shows a schematic example of the no-entry area A1 and various parameters when the driven object 50 is the back spindle 10B and the interference object 55 is the tool rest part U1 which combines the back tool rest 40B and multiple tool holders TU1. The multiple tools T1 shown in Figure 4 are drill tools. The back spindle 10B, which is provided with the back spindle 11B that grips the workpiece W1, moves in the X2-axis direction by the X2-axis motor M4 and moves in the Z2-axis direction by the Z2-axis motor M5 as shown in Figure 2. The workpiece W1 gripped by the back spindle 11B is machined by one of the multiple tools T1 attached to the tool rest part U1 including the back tool rest 40B. In Figure 4, the left direction along the Z2 axis is the positive direction, and the right direction along the Z2 axis is the negative direction. In the example shown in FIG. 4, the drive axis direction 3 along which the distance from the workpiece W1 to the tool T1 changes is the Z2 axis direction, the drive unit U2 that moves the driven object 50 is the Z2 axis motor M5, and the switching drive unit U5 that switches the tool T1 is the X2 axis motor M4.

The tool holders TU1 of the tool rest U1 are attached to the facing surface 41 of the back tool rest 40B facing the back spindle 11B. A tool T1 is attached to each tool holder TU1. Therefore, the tool rest U1 can attach multiple tools T1 at different positions on a virtual plane 4 intersecting the Z2-axis direction. The X2-axis motor M4 moves the back spindle 10B in the X2-axis direction in accordance with the control of the NC device 70 so that the workpiece W1 held by the back spindle 11B faces one of the multiple tools T1 in the Z2-axis direction. This allows the tool facing the workpiece W1 to be switched from the multiple tools T1 attached to the tool rest U1. The adjustment of the protruding length Lt of the tool T1 from the tool holder TU1 is performed in a state in which the tool T1 faces the workpiece W1. The tool of the multiple tools T1 whose protruding length Lt is adjusted is called the target tool T2. The Z2-axis motor M5 moves the back spindle 10B, which is provided with the back spindle 11B that grips the workpiece W1, in the Z2-axis direction under the control of the NC device 70. This changes the distance from the workpiece W1 to the opposing tool T1.

In order to prevent interference between the back spindle 11B and the tool rest U1, the lathe 1 has a no-entry area A1 set according to the shape of the tool rest U1. When the control position (corresponding to machine coordinate Pm) of the end face 11c of the back spindle 11B approaching the tool rest U1 on the Z2 axis reaches the boundary A1b (corresponding to the no-entry position Pa) of the no-entry area A1, the NC device 70 stops the movement of the back spindle stock 10B. As shown in FIG. 4, the position of the boundary A1b of the no-entry area A1 on the Z2 axis may differ depending on the tool T1 used to machine the workpiece W1.

Now, with reference to FIG. 5 as well, various parameters according to the position of the back headstock 10B on the Z2 axis will be described. The upper part of FIG. 5 shows various parameters in state ST1 where the machine coordinate Pm on the Z2 axis is 0. The lower part of FIG. 5 shows various parameters in state ST2 where the workpiece W1 and the target tool T2 are in contact in the Z2 axis direction.

First, the point (Z2=0) specific to the machine that is the reference point of the machine on the Z2 axis is set as the machine origin. The machine origin Z2=0 is also the origin position of the end face 11c of the back spindle 11B on the Z2 axis. The machine coordinate Pm indicates the position of the end face 11c on the Z2 axis with the machine origin Z2=0 as the base point, and is a positive value when the end face 11c is to the left of the machine origin Z2=0 in Figures 4 and 5. The machine coordinate Pm is an example of the current position of the driven object 50.
The workpiece coordinate Pw is a coordinate used for machining the workpiece W1, and is the coordinate of the end face of the product on the Z2 axis. When cutting the end face W1a of the workpiece W1 to produce a product, the position is the position excluding the end chamfer allowance F. The end chamfer allowance F is an example of the machining length for machining the end face W1a of the workpiece W1 in the Z2 axis direction, and is a positive value. When there is an end chamfer allowance F, the workpiece coordinate Pw is the coordinate of the end face W1a of the workpiece W1 excluding the end chamfer allowance F.

The correction amount (O) is an offset value for calculating the workpiece coordinate Pw from the machine coordinate Pm, and is the amount of shift from the machine origin Z2=0. The correction amount O is the sum of the distance O1 from the tip T1a of the target tool T2 facing the workpiece W1 in the Z2-axis direction to the end face of the product, and the distance O2 from the end face 11c of the back spindle 11B to the machine origin Z2=0 in the Z2-axis direction. The workpiece coordinate Pw is the value obtained by subtracting the correction amount O from the machine coordinate Pm.
Pw=Pm-O...(1)
In the G132 mode in which the back spindle 11B grips the workpiece W1, when the end face of the product is to the right of the tip T1a of the target tool T2 in FIGS.

The shape correction G is an example of the position of the target tool T2 on the Z2 axis, and is the distance from the tool attachment reference position Pb to the tip T1a of the target tool T2 on the Z2 axis. The tool attachment reference position Pb shown in Figures 4 and 5 is the machine origin Z2 = 0. Therefore, the shape correction G is usually a positive value.
The protrusion registration length K is the length by which the product held by the back spindle 11B protrudes from the end face 11c of the back spindle 11B in the Z-axis direction, and is the positive value obtained by subtracting the gripping length Lg of the workpiece W1 from the length Lp of the product in the Z2-axis direction. When the end face W1a of the workpiece W1 is cut to produce a product, the protrusion registration length K is the length of the workpiece W1 before back machining minus the end chamfering allowance F and the gripping length Lg. In the G130 mode, in which the back spindle 11B does not grip the workpiece W1, the protrusion registration length K can be treated as 0 in the following formula.

In the G130 mode in which the back spindle 11B does not grip the workpiece W1, the correction amount O is equal to the shape correction G.
O = G ... (2)
From equations (1) and (2), the workpiece coordinate Pw is the value obtained by subtracting the shape correction G from the machine coordinate Pm.
Pw=Pm-G...(3)

In the G132 mode in which the back spindle 11B grips the workpiece W1, the correction amount O is a value obtained by subtracting the protrusion registration length K from the shape correction G.
O = G - K ... (4)
From the formulas (1) and (4), the workpiece coordinate Pw is calculated by subtracting the shape correction G from the machine coordinate Pm and adding the registered protrusion length K to it.
Pw=Pm-(G-K)=Pm-G+K...(5)

When the target tool T2 is reattached to the tool rest U1, the shape correction G is updated based on the calculated shape correction G. A calculation formula for updating the shape correction G will be described below.
In the G132 mode in which the back spindle 11B grips the workpiece W1, the shape correction after update is calculated so that the workpiece coordinate Pw becomes -F in the state ST2 in which the tip T1a of the target tool T2 and the end face W1a of the workpiece W1 are in contact as shown in the lower part of Fig. 5. Note that "c" is added to the parameter representing the value before the update, and "n" is added to the parameter representing the value after the update. For example, the shape correction G is represented as Gc before the update, and as Gn after the update. As will be described later, the shape correction G is updated at the timing when the Z setting key 540 shown in Fig. 10 is operated.

From equation (1), the workpiece coordinate Pwc before the update is the value obtained by subtracting the correction amount Oc before the update from the machine coordinate Pm.
Pwc=Pm-Oc...(6)
Furthermore, from equation (1), the updated workpiece coordinate Pwn is the machine coordinate Pm minus the updated correction amount On, which is −F.
Pwn=Pm-On=-F...(7)

When the machine coordinate Pm is eliminated from the formulas (6) and (7), the post-update correction amount On becomes the sum of the pre-update correction amount Oc and the end chamfer allowance F to the pre-update workpiece coordinate Pwc.
On=Pwc+Oc+F...(8)
From the formulas (4) and (8),
Gn-K=Pwc+(Gc-K)+F
Therefore, the updated shape correction Gn is equal to the value obtained by adding the pre-update shape correction Gc and the end chamfer allowance F to the pre-update workpiece coordinate Pwc.
Gn=Pwc+Gc+F...(9)

In the G130 mode in which the rear spindle 11B does not grip the workpiece W1, the protrusion registration length K is 0 and the end chamfer allowance F is 0, so the updated shape correction Gn is the value obtained by adding the pre-update workpiece coordinate Pwc to the pre-update shape correction Gc.
Gn=Pwc+Gc...(10)

To improve the machining accuracy of the workpiece W1, it is preferable to shorten the protruding length Lt of the tool T1 from the tool holder TU1 as much as possible. However, the shorter the protruding length Lt of the tool T1, the more it is necessary to bring the back spindle 11B and the tool rest U1 closer together, and the more likely it is that the no-entry area A1 will prevent the back spindle 11B and the tool rest U1 from being able to come closer together. Here, if interference between the tool or tool holder and the spindle occurs during simulation of the machining program, changing the tool or tool holder and repeating the simulation of the machining program again requires time-consuming and cumbersome work.

In this specific example, when the operator operates the handle 83 to manually move the driven object 50 of the target control axis, the distance Lot that the driven object 50 reaches into the no-entry area A1 is displayed, as shown in the example of FIG. 10. This makes it possible to easily adjust the protruding length Lt of the tool T1 when attaching the tool T1 to the tool rest U1 without having to simulate the machining program. Below, an example of the tool attachment assistance process performed on the lathe 1 will be described with reference to FIGS. 6 to 11.

(3) Examples of tool installation assistance processes:
6 shows an example of a tool attachment assist process executed by the lathe 1 when the operator attaches the tool T1 to the tool rest U1. The tool attachment assist process is mainly performed by the NC device 70, and is started after front machining, for example. FIGS. 7 to 11 show schematic examples of screens displayed on the display unit 82.
Before performing the tool attachment assistance process, the operator sets the protruding length of the tool T1 to a short length and temporarily fixes the tool T1 to the tool rest U1.
In this specific example, a case will be described in which the Z2 axis is selected by the control axis key 81c shown in FIG. 3 as the control axis for performing manual handle feed.

First, the operator attaches the tool T1 to the tool holder TU1 attached to the back tool rest 40B in a temporary position, and adjusts the position of the back spindle 10B on the X2 axis using the input unit 81 so that the back spindle 11B faces the tool T1 whose protrusion length Lt is to be adjusted. When the tool attachment assistance process starts, the NC device 70 acquires the product length Lp and the gripping length Lg of the workpiece W1 (step S102). For example, the NC device 70 may accept the input of the product length Lp through the input unit 81, or may read or calculate the gripping length Lg from the machining program P2 shown in FIG. 2. If the machining program P2 includes the product length Lp, the NC device 70 may read or calculate the product length Lp from the machining program P2.

The calculation of the protrusion registration length K is performed automatically before execution, just like the other values. As a simple example, the protrusion registration length K may be calculated by subtracting the grip length Lg from the product length Lp.

Then, the NC device 70 displays a tool selection screen 500 as shown in FIG. 7 on the display unit 82 (step S104). The tool selection screen 500 shown in FIG. 7 has a work coordinate display section 511, a shape correction display section 512, a tool list display section 513, a mode display section 520, soft keys 81g, and the like. The tool selection screen 500 also has a cursor 510. The position of the cursor 510 can be changed by operating the cursor key 81d shown in FIG. 3.

The work coordinate display section 511 displays the work coordinates on the X1, Y1, Z1, X2, and Z2 axes, for example, the coordinates of the end face of the product in the case of the Z2 axis. When the work W1 held by the back spindle 11B is machined by the tool T1 attached to the back tool rest 40B, the work coordinate Pw on the Z2 axis is displayed on the work coordinate display section 511. The work coordinate Pw is a value obtained by adding the protrusion registration length K to the machine coordinate Pm.
The shape correction display section 512 displays information on the shape correction G. When the workpiece W1 gripped by the back spindle 11B is machined with the tool T1 attached to the back tool rest 40B, the shape correction G of the Z axis, i.e., tool position information IN2 representing the position of the target tool T2 in the Z2 axis direction, is displayed in the shape correction display section 512, as in the update screen 502 shown in Fig. 11. The initial value of the shape correction G is 0. The shape correction display section 512 is an example of the tool position information display section U8 that displays the tool position information IN2.

A list of the tools T1 attached to the back tool rest 40B is displayed in the tool list display section 513. Four types of tools T20, T21, T22, and T23 are shown in FIG.
The mode display section 520 displays "G132" indicating the grip mode 521 in which the back spindle 11B grips the workpiece W1, and "G130" indicating the non-grip mode 522 in which the back spindle 11B does not grip the workpiece W1. The * mark displayed on the mode display section 520 indicates a mode selected from the G132 mode and the G130 mode. In the tool selection screen 500 shown in FIG. 7, the * mark is added to "G132", which indicates that the G132 mode is selected. The G132 mode and the G130 mode are switched by operating the mode switching key 523 included in the soft key 81g. The mode display section 520 is an example of a mode reception section U7 that receives either the grip mode 521 or the non-grip mode 522.

When the G132 mode is selected as shown in FIG. 7, the NC device 70 displays, on the tool selection screen 500, a protrusion registration length display section 514 including the protrusion registration length K calculated in step S104, and an end chamfer allowance display section 515 including the end chamfer allowance F. The end chamfer allowance F displayed initially may be a default value, a value described in the machining program P2, or a value calculated from the machining program P2.

When the G130 mode is selected as shown in Figure 8, the protrusion registration length display section 514 and the end chamfer allowance display section 515 are not displayed on the tool selection screen 500.

Next, the NC device 70 accepts various operations through the input unit 81 based on the tool selection screen 500 (step S106).
In the mode display section 520 shown in Fig. 7 and 8, a process is performed in which either the G132 mode or the G130 mode is accepted by the mode switching key 523. The input section 81 capable of executing this process is an example of the mode acceptance section U7. In the end chamfer allowance display section 515 shown in Fig. 7, a process is performed in which the input of the end chamfer allowance F is accepted by the character keys 81e, the input key 81f, etc. This process corresponds to the tool position information display section U8 accepting an input of the machining length for machining the end face W1a of the workpiece W1 in the drive shaft direction 3.

In the tool list display section 513 shown in Fig. 7 and 8, a process is performed to accept the selection of the target tool T2 for which the protrusion length Lt is adjusted from among the multiple tools T1 attached to the tool rest section U1 by using the cursor key 81d or button 84 shown in Fig. 3. The input section 81 capable of executing this process is an example of the target tool receiving section U6. The NC device 70 monitors the pressing of the START button included in the button 84 and waits until the pressing of the START button is received by the input section 81 (step S108). When the pressing of the START button is received, the screen switches to the tool selection screen 500 as shown in Fig. 9. In addition, when the START button is pressed, the calculation process of the workpiece coordinate Pw is performed according to the formula (5) and displayed. If the selected target tool T2 does not face the workpiece W1, the NC device 70 may drive the X2-axis motor M4 to move the back headstock 10B in the X2-axis direction so that the selected target tool T2 faces the workpiece W1. The tool selection screen 500 shown in FIG. 9 has soft keys 81g including a handle key 530. The handle key 530 is an operation unit for switching to a handle mode in which manual handle feed is performed.

Then, the NC unit 70 waits until it receives operation of the handle key 530 (step S110), and when it receives operation of the handle key 530, it proceeds to step S112. In step S112, the NC unit 70 calculates the distance Lot that the rear spindle 11B reaches the no-entry area A1 in the Z2-axis direction based on the machine coordinate Pm of the rear spindle 11B in the Z2-axis direction and the no-entry area information IN1 that represents the no-entry area A1.

4, the distance Lot from the machine coordinate Pm, which indicates the position of the end face 11c of the back spindle 11B on the Z2 axis, to the boundary A1b of the entry-prohibited area A1 may differ depending on the position of the center line AX2 of the back spindle 11B on the X2 axis. Therefore, the NC device 70 acquires the position on the X2 axis of the center line AX2, which is the machine coordinate of the back spindle 11B on the X2 axis, obtains the entry-prohibited position Pa, which is the Z2 position of the boundary A1b of the entry-prohibited area A1 at the position of the center line AX2 on the X2 axis, from the entry-prohibited area information IN1, and calculates the distance Lot by subtracting the machine coordinate Pm from the entry-prohibited position Pa.
Lot=Pa-Pm...(11)
From the above, when the target tool T2 faces the workpiece W1 in the Z2 axis direction, the distance Lot to the entry-prohibited area A1 is calculated based on the machine coordinates Pm and the entry-prohibited area information IN1.

10, the NC device 70 causes the display unit 82 to display a handle mode screen 501 including the distance Lot to the entry-prohibited area A1 (step S114). The handle mode screen 501 shown in FIG. 10 displays the distance Lot to the entry-prohibited area A1, such as "distance to OT: 46.001 mm". In this manner, the distance display unit U4 calculates and displays the distance Lot to the entry-prohibited area A1 based on the current position of the driven object 50 and the entry-prohibited area information IN1 when the target tool T2 faces the workpiece W1 in the drive shaft direction 3. When the operator operates the handle 83 (see FIG. 3) while the handle mode screen 501 is displayed, the back headstock 10B moves in the Z2-axis direction in response to the operation of the handle 83.
In addition, the handle mode screen 501 is provided with soft keys 81g including a Z setting key 540. The Z setting key 540 is an operation unit for updating the shape correction G that represents the position of the target tool T2 on the Z2 axis. In the G132 mode, the Z setting key 540 is operated when the end face W1a of the workpiece W1 comes into contact with the tip T1a of the target tool T2, and in the G130 mode, the Z setting key 540 is operated when the end face 11c of the back spindle 11B comes into contact with the tip T1a of the target tool T2.

Now, referring to Figures 13 to 15, an example of adjusting the protruding length Lt of the target tool T2 will be described. Figure 13 shows a schematic example of the tool rest U1 and the back headstock 10B immediately after the target tool T2 has been temporarily fixed. Figure 14 shows a schematic example of the end face W1a of the workpiece W1 being brought into contact with the tip T1a of the target tool T2. Figure 15 shows a diagram of the target tool T2 performing drilling of the maximum machining length Ld, and shows a schematic example of the back headstock 10B moving forward until the machine coordinate Pm reaches the machining position of the maximum machining length Ld. For convenience of illustration, Figures 13 to 15 show the lengths of the workpiece W1 and the target tool T2 in an exaggerated manner. When the allowance length is α, the machine coordinate Pm is Pa-α, which is obtained by subtracting the allowance length α from the no-entry position Pa.

15, distance Lft is the distance from the opposing surface 41 of the back tool rest to the tip T1a of the target tool T2, and distance Lfb is the distance from the opposing surface 41 of the back tool rest to the tool attachment reference position Pb. For convenience of explanation, the difference Lfb-Lft between distances Lfb and Lft, and the calculation formula for distance Lfb are shown below.
The difference Lfb-Lft between the distances Lfb and Lft is expressed by the following formula using the no-entry position Pa, the registered protrusion length K, the maximum machining length Ld from the end face of the part of the workpiece W1 excluding the end chamfering allowance F, and the margin length α. The margin length α is optimally about 1 to 2 mm.
Lfb-Lft=Pa+K-Ld-α...(12)
The distance Lft that minimizes the protrusion length Lt of the target tool T2 is expressed by the following calculation formula based on formula (12).
Lft=Lfb-Pa-K+Ld+α...(13)
In this specific example, the operator does not need to perform the calculations of the above-mentioned expressions (12) and (13).

In this specific example, the protrusion length Lt of the target tool T2 can be adjusted as follows.
First, Fig. 13 is a diagram before adjusting the protruding length Lt of the target tool T2. In a state in which the target tool T2 and the workpiece W1 are separated as shown in Fig. 13, the operator performs a temporary fixing operation of the target tool T2 and advances the Z2 axis by operating the handle 83. Then, the operator determines that the distance Lo to the no-entry area A1 is Lot = Ld + F + α (14)
The Z2 axis is advanced by operating the handle 83 until the value represented by

Figure 14 shows the state in which the back headstock 10B has been moved forward to a position where the protruding length Lt of the target tool T2 is adjusted. The operator moves the target tool T2, which is temporarily fixed as shown in Figure 14, so that it contacts the end face W1a of the workpiece W1, and tightens the cap TU1c to fix the target tool T2 to the tool unit TU1. Before being fixed, the target tool T2 can move in a direction along the Z2 axis. If the target tool T2 is not temporarily fixed but is already attached, the distance Lot to the no-entry area A1 when the target tool T2 contacts the end face W1a of the workpiece W1 is confirmed, and if the protruding length Lt of the target tool T2 is short, it is adjusted by reattaching it.

Here is an example with concrete numbers.
First, the protrusion registration length K is 20.0 mm, the maximum machining length Ld is 15.0 mm, the end chamfering allowance F is 0.1 mm, and the margin length α is 2.0 mm. The maximum value Lot_max of the distance Lot to the no-entry area A1 is Lot_max = 46.0 mm. If the target distance Lot when the above numbers are applied is Lot_min, then from equation (14), Ld + F + α = 15.0 mm + 0.1 mm + 2.0 mm = 17.1 mm.
In Fig. 13, the relationship of the distance Lot is Lot_max ≥ Lot ≥ Lot_min, and the Z2 axis of the back headstock 10B is advanced by operating the handle 83 so that Lot = Lot_min = 17.1 mm in the position shown in Fig. 14. In this state, the target tool T2 is moved so as to contact the end face W1a of the workpiece W1, and the cap TU1c is tightened to fix the target tool T2 to the tool unit TU1. This makes it possible to easily set the target tool T2 to an appropriate length without using simulations or the like.

As a comparative example, an example in which an operator calculates the distance Lft in the above-mentioned formula (13) will be described.
The calculation of the distance Lft in the above formula (13) is tedious since it requires multiple parameters, for the following reasons.
First, the distance Lfb and the no-entry position Pa are not displayed on the screen because they are inherent values of the machine and are not values that the operator takes into consideration. Also, since a lathe is a collection of cylindrical shapes with different diameters, it is difficult to measure the distance Lft with a vernier caliper, and it is necessary to create a dedicated jig. When the tool T1 is a drill tool, the tool T1 is fixed to the tool unit TU1 by tightening the cap TU1c. The protruding length Lt of the tool T1 changes depending on whether the cap TU1c is tightened, and therefore cannot be measured before the tool T1 is attached.

In contrast, in this specific example, the formula (14) calculated by the operator has few parameters and can be calculated easily. This is because the maximum machining length Ld included in the formula (14) can be read from the machining program P2 or the machining drawing.

Next, the NC device 70 branches the process depending on whether the Z setting key 540 has been operated (step S116). If the Z setting key 540 has not been operated, the process returns to step S112. Therefore, when the position of the end face 11c of the back spindle 11B, i.e., the machine coordinate Pm, changes, a new distance Lot is calculated in step S112 and displayed on the handle mode screen 501 in step S114. Therefore, the operator can adjust the mounting position of the target tool T2 relative to the tool holder TU1 while visually checking the display of the distance Lot leading to the no-entry area A1. For example, when the G132 mode in which the back spindle 11B grips the workpiece W1 is selected, the operator can specifically determine whether the distance Lot leading to the no-entry area A1 is appropriate in the state ST2 (see the lower part of FIG. 5) in which the end face W1a of the workpiece W1 is brought into contact with the tip T1a of the target tool T2 by operating the handle 83. If the operator determines that the distance Lot is not appropriate, he or she can adjust the mounting position of the target tool T2 relative to the tool holder TU1. When the G130 mode is selected, which does not allow the back spindle 11B to grip the workpiece W1, the operator can specifically determine whether the distance Lot, which reaches the no-entry area A1 while the end face 11c of the back spindle 11B is in contact with the tip T1a of the target tool T2 by operating the handle 83, is appropriate. If the operator determines that the distance Lot is not appropriate, he or she can adjust the mounting position of the target tool T2 relative to the tool holder TU1.

When the Z setting key 540 is operated, the NC device 70 calculates the shape correction G according to the above-mentioned formula (9) or (10) (step S118). In this case, the calculated shape correction G is set in the shape correction display section 512.

When the G132 mode is selected, it is assumed that the end face W1a of the workpiece W1 is in contact with the tip T1a of the target tool T2 in state ST2 as shown in the lower part of FIG. 5. The operator operates the Z setting key 540 in state ST2 shown in the lower part of FIG. 5. In this case, the updated shape correction Gn is calculated according to formula (9), that is, Gn=Pwc+Gc+F. The NC device 70 acquires the workpiece coordinate Pwc indicating the position where the workpiece W1 and the tool T1 contact in the Z2 axis direction when the back spindle 11B is gripping the workpiece W1, and calculates the updated shape correction Gn based on this workpiece coordinate Pwc. Note that when the shape correction Gn is calculated for the first time after the tool attachment assistance process shown in FIG. 6 is started, the shape correction Gn is the value obtained by adding the end chamfer allowance F to the workpiece coordinate Pwc before the update, since the shape correction Gc before the update is an initial value 0.
Gn=Pwc+F...(9)'

When the G130 mode is selected, it is assumed that the end surface 11c of the back spindle 11B is in contact with the tip T1a of the target tool T2. The operator operates the Z setting key 540 under this assumption. In this case, the updated shape correction Gn is calculated according to the formula (10), that is, Gn = Pwc + Gc. When the back spindle 11B is not gripping the workpiece W1, the NC device 70 acquires the workpiece coordinate Pwc indicating the position where the back spindle 11B and the tool T1 contact in the Z2 axis direction, and calculates the updated shape correction Gn based on the workpiece coordinate Pwc without using the end chamfering allowance F. Note that when the shape correction Gn is calculated for the first time after the tool attachment assistance process shown in FIG. 6 is started, the shape correction Gn becomes the workpiece coordinate Pwc before the update, since the shape correction Gc before the update is an initial value 0.
Gn=Pwc...(10)'

As shown in FIG. 11, the NC device 70 also displays the update screen 502 including the tool position information IN2 representing the updated shape correction Gn on the display unit 82 (step S120). The shape correction Gn indicates the position of the target tool T2 in the Z2-axis direction. When the G132 mode is selected, the tool position information display unit U8 that displays the tool position information IN2 acquires the work coordinate Pw, which is the position where the workpiece W1 and the tool T1 contact in the Z2-axis direction when the back spindle 11B is gripping the workpiece W1, and displays the tool position information IN2 based on this work coordinate Pw. According to formula (9), the tool position information IN2 is updated based on the work coordinate Pw and the end chamfering allowance F. When the G130 mode is selected, the tool position information display unit U8 acquires the work coordinate Pw, which is the position where the back spindle 11B and the tool T1 contact in the Z2-axis direction, and displays the tool position information IN2 based on this work coordinate Pw.

The processing of steps S106 to S120 in FIG. 6 is performed for all tools T1 attached to the tool rest U1. When the processing of displaying the updated screen 502 including the tool position information IN2 on the display unit 82 (step S120) is completed, the NC device 70 ends the tool attachment assistance processing.

When the tool attachment assistance process is performed, the distance Lot in the Z2-axis direction by which the back spindle 11B reaches the entry-prohibited area A1 is displayed on the handle mode screen 501 as shown in FIG. 10. If the distance Lot is not displayed, the operator must perform the troublesome task of calculating the protruding length Lt by himself so that the back spindle 11B does not reach the entry-prohibited area A1 and attaching the tool T1 to the tool rest U1. If it is difficult to calculate the protruding length Lt, it may be found that the back spindle 11B reaches the entry-prohibited area A1 when mass production processing is actually started, and at the time of finding out, it becomes necessary to reattach the tool T1. In this specific example, since the distance Lot to the entry-prohibited area A1 can be found numerically by looking at the handle mode screen 501, the operator can easily determine whether the back spindle 11B can machine the workpiece W1 without entering the entry-prohibited area A1 at the current attachment position of the tool T1. The operator can also determine whether the protruding length Lt of the tool T1 is longer than necessary. Therefore, the operator can appropriately adjust the protrusion length Lt of the tool T1 based on the specific value of the distance Lot. In addition, since the target tool T2 for which the protrusion length Lt is to be adjusted can be switched on the tool selection screen 500 shown in Figures 7 and 8, the protrusion length Lt can be adjusted for all tools T1 attached to the tool rest U1 based on the specific value of the distance Lot. Therefore, in this specific example, the protrusion length of the tool can be easily adjusted without simulating the machining program.
Furthermore, the distance Lot to the no-entry area A1 is displayed, the position of the Z2 axis for fixing the tool T1 is displayed, and the eigenvalues of the machine have already been calculated by the NC unit 70, so the operator need only consider the shape he or she wishes to machine.

Furthermore, the operator can see the updated shape correction Gn, which indicates the mounting position of the target tool T2 on the Z2 axis, numerically whether the G132 mode is used, in which the back spindle 11B grips the workpiece W1, or the G130 mode, in which the back spindle 11B does not grip the workpiece W1.

(4) Modifications:
The present invention contemplates various modifications.
For example, the lathe to which the present technology can be applied is not limited to a type equipped with a guide bush, but may be a type without a guide bush, or a type in which the use of a guide bush can be switched on and off.Furthermore, the lathe to which the present technology can be applied is not limited to a moving spindle type lathe, but may be a fixed spindle type lathe in which the front headstock does not move.

In the above-described specific example, the back headstock 10B moves in the Z2-axis direction, but the back tool rest 40B may move in the Z2-axis direction without moving the back headstock 10B. In this case, the tool rest unit U1 including the back tool rest 40B becomes the driven object 50. In addition, when both the back headstock 10B and the back tool rest 40B move in the Z2-axis direction, both the back headstock 10B and the tool rest unit U1 may be treated as the driven object 50.
Furthermore, in the above-mentioned specific example, the back headstock 10B moves in the X2-axis direction, but the back tool rest 40B may move in the X2-axis direction without moving the back headstock 10B. In this case, the X2-axis drive motor that moves the back tool rest 40B in the X2-axis direction becomes the switching drive unit U5. Also, when both the back headstock 10B and the back tool rest 40B move in the X2-axis direction, the drive motors for both the back headstock 10B and the tool rest unit U1 can be treated as the switching drive unit U5.

The headstock to which the present technology can be applied is not limited to the rear headstock 10B, but may be the front headstock 10A.
The tool rest section to which the present technology can be applied is not limited to the combination of the back tool rest 40B and the tool holder TU1, but may be a combination of a turret tool rest and a tool holder, a comb tool rest for selecting multiple tools, etc. When the tool rest section includes a turret tool rest, the drive section that rotates the turret may be treated as a switching drive section.

Figure 12 shows a schematic example of the no-entry area A1 and various parameters when the driven object 50 is the tool rest U1 including at least the main tool rest 40A and the interference object 55 is the front spindle stock 10A. The tool T1 shown in Figure 12 is a tool bit, but the tool attached to the tool rest U1 may include a rotary drill or the like. As shown in Figure 2, the main tool rest 40A moves in the X1-axis direction by the X1-axis motor M2 and moves in the Y1-axis direction by the Y1-axis motor M3. The workpiece W1 held by the front spindle 11A is machined by one of the multiple tools T1 attached to the tool rest U1 including at least the main tool rest 40A. In Figure 12, the upward direction along the X1 axis is the positive direction, and the downward direction along the X1 axis is the negative direction. In the example shown in FIG. 12, the drive axis direction 3 in which the distance from the workpiece W1 to the tool T1 changes is the X1 axis direction, the drive unit U2 that moves the driven object 50 is the X1 axis motor M2, and the switching drive unit U5 that switches the tool T1 is the Y1 axis motor M3.

The main tool rest 40A can mount multiple tools T1 at different positions on a virtual plane 4 that intersects with the X1-axis direction. The Y1-axis motor M3, under the control of the NC device 70, moves the main tool rest 40A in the Y1-axis direction so that the side of the workpiece W1 held by the front spindle 11A faces one of the multiple tools T1 in the X1-axis direction. This allows the tool facing the workpiece W1 to be switched from the multiple tools T1 attached to the main tool rest 40A. The adjustment of the protruding length Lt of the tool T1 from the main tool rest 40A is performed in a state in which the tool T1 faces the workpiece W1. The X1-axis motor M2, under the control of the NC device 70, moves the main tool rest 40A in the X1-axis direction. This changes the distance Lot from the workpiece W1 to the facing tool T1.

In order to prevent interference between the front headstock 10A and the main tool rest 40A, a no-entry area A1 is set on the lathe 1 according to the shape of the front headstock 10A. When the control position (corresponding to the machine coordinate Pm) of the main tool rest 40A approaching the front headstock 11A on the X1 axis reaches the boundary A1b (corresponding to the no-entry position Pa) of the no-entry area A1, the NC device 70 stops the movement of the main tool rest 40A.

Here, the point (X1=0) specific to the machine that is the reference point of the machine on the X1 axis is set as the machine origin. The machine origin X1=0 shown in FIG. 12 is aligned with the center line AX1 of the front spindle 11A. The machine coordinate Pm indicates the position on the X1 axis of the main tool rest 40A with the machine origin X1=0 as the base point. The machine coordinate Pm shown in FIG. 12 is the position on the X1 axis of the virtual plane 4 with the machine origin X1=0 as the base point, and is a positive value when it is above the machine origin X1=0. The machine coordinate Pm is an example of the current position of the driven object 50.
The workpiece coordinate Pw is the coordinate of the tip T1a of the target tool T2 on the X1 axis. The radius d of the workpiece W1 is a parameter that replaces the above-mentioned protrusion registration length K. The position on the X1 axis of the side surface of the workpiece W1 that faces the target tool T2 is d. The radius d of the workpiece W1 can be read out or calculated from the machining program P2. The distance Lot from the main tool rest 40A to the no-entry area A1 is the value obtained by subtracting the machine coordinate Pm from the no-entry position Pa, as shown in the above-mentioned formula (11). The distance Lot shown in FIG. 12 is a negative value. The NC device 70 displays the distance Lot, which is a negative value, on the handle mode screen, similar to the handle mode screen 501 shown in FIG. 10.

The operator can see the distance Lot to the no-entry area A1 in numerical form by looking at the handle mode screen, and can adjust the protruding length Lt of the tool T1 based on the specific value of the distance Lot. Therefore, in the example shown in Figure 12, the protruding length of the tool can be easily adjusted without simulating the machining program.

(5) Conclusion:
As described above, according to the present invention, it is possible to provide a technology for a lathe or the like that allows the protruding length of a tool to be easily adjusted without performing a simulation, through various aspects. Of course, even if the technology is composed only of the constituent elements according to the independent claims, the basic functions and effects described above can be obtained.
In addition, configurations in which the configurations disclosed in the above examples are substituted with each other or the combination is changed, configurations in which the configurations disclosed in the publicly known techniques and the above examples are substituted with each other or the combination is changed, etc. The present invention also includes these configurations.

1... lathe, 3... drive shaft direction, 4... virtual plane,
10... Headstock, 10A... Front headstock, 10B... Back headstock,
11... Main shaft, 11A... Front main shaft, 11B... Back main shaft, 11c... End surface,
40... tool rest, 40A... main tool rest, 40B... back tool rest, 41... opposing surface,
50 ... driven object, 55 ... interference object,
70...NC device, 72...ROM,
80: Operation panel, 81: Input unit, 82: Display unit, 82a: Screen, 83: Handle,
500...tool selection screen, 501...handle mode screen, 502...update screen,
511: workpiece coordinate display section; 512: shape correction display section; 513: tool list display section;
514: Protrusion registration length display section; 515: End chamfer allowance display section;
520: Mode display section, 521: Holding mode, 522: Non-holding mode,
523: mode switching key, 530: handle key, 540: Z setting key,
A1...Prohibited area, A1b...Boundary,
AX1, AX2...center line,
F: End chamfering allowance (example of machining length), G: Shape correction (example of tool position),
IN1...Prohibited area information, IN2...Tool position information,
Lg: gripping length of workpiece; Lot: distance to no-entry area;
Lt: tool protrusion length, Lp: product length,
K: extension registration length,
M1...Z1 axis motor, M2...X1 axis motor, M3...Y1 axis motor,
M4...X2 axis motor, M5...Z2 axis motor,
Pa...No entry position, Pb...tool installation reference position,
Pm: Machine coordinates (an example of the current position of the driven object),
Pw: workpiece coordinates (example of the coordinates of the end surface of the workpiece),
T1...tool, T1a...tip, T2...target tool, TU1...tool holder,
U1: Tool rest unit, U2: Drive unit, U3: Memory unit, U4: Distance display unit,
U5: switching drive unit, U6: target tool receiving unit, U7: mode receiving unit,
U8...Tool position information display section,
W1...workpiece, W1a...end surface.

Claims (6)

A headstock having a spindle for gripping a workpiece;
a tool rest portion to which a tool for machining the workpiece held by the spindle can be attached;
a drive unit that moves at least one of the headstock and the tool rest in a drive axis direction in which a distance from the workpiece to the tool changes;
A storage unit that stores entry-prohibited area information that indicates an entry-prohibited area of the driving object;
a distance display unit that calculates and displays a distance from the driven object to the no-entry area in the drive axis direction based on a current position of the driven object in the drive axis direction and the no-entry area information;
a tool position information display unit that displays tool position information representing a position of the tool in the drive shaft direction ,
When a setting key for acquiring the position where the workpiece and the tool contact in the drive shaft direction is operated while the spindle is gripping the workpiece, the tool position information display unit acquires the position where the workpiece and the tool contact in the drive shaft direction, and updates and displays the tool position information based on the acquired position . A headstock having a spindle for gripping a workpiece;
a tool rest portion to which a tool for machining the workpiece held by the spindle can be attached;
a drive unit that moves at least one of the headstock and the tool rest in a drive axis direction in which a distance from the workpiece to the tool changes;
A storage unit that stores entry-prohibited area information that indicates an entry-prohibited area of the driving object;
a distance display unit that calculates and displays a distance from the driven object to the no-entry area in the drive axis direction based on a current position of the driven object in the drive axis direction and the no-entry area information;
a tool position information display unit that displays tool position information representing a position of the tool in the drive shaft direction,
When a setting key for acquiring the contact position between the spindle and the tool in the drive shaft direction is operated while the spindle is not gripping the workpiece, the tool position information display unit acquires the contact position between the spindle and the tool in the drive shaft direction, and updates and displays the tool position information based on the acquired position. A headstock having a spindle for gripping a workpiece;
a tool rest portion to which a tool for machining the workpiece held by the spindle can be attached;
a drive unit that moves at least one of the headstock and the tool rest in a drive axis direction in which a distance from the workpiece to the tool changes;
A storage unit that stores entry-prohibited area information that indicates an entry-prohibited area of the driving object;
a distance display unit that calculates and displays a distance from the driven object to the no-entry area in the drive axis direction based on a current position of the driven object in the drive axis direction and the no-entry area information;
a mode reception unit that receives either a gripping mode in which the spindle grips the workpiece or a non-grip mode in which the spindle does not grip the workpiece;
a tool position information display unit that displays tool position information representing a position of the tool in the drive shaft direction,
The tool position information display unit includes:
When the mode is the gripping mode, when a setting key for acquiring a contact position between the workpiece and the tool in the drive shaft direction is operated in a state in which the spindle is gripping the workpiece, the contact position between the workpiece and the tool in the drive shaft direction is acquired, and the tool position information is updated and displayed based on the acquired position;
When the mode is the non-gripping mode, when a setting key for acquiring the contact position between the spindle and the tool in the drive shaft direction is operated while the spindle is not gripping the workpiece, the lathe acquires the contact position between the spindle and the tool in the drive shaft direction, and updates and displays the tool position information based on the acquired position. the tool rest portion is capable of mounting a plurality of tools at different positions on a virtual plane intersecting the drive shaft direction,
The lathe according to any one of claims 1 to 3 , further comprising a switching drive unit that switches a tool for machining the workpiece from among the plurality of tools attached to the tool rest unit. a target tool receiving unit that receives a selection of a target tool to have its projection length adjusted from among the plurality of tools attached to the tool rest unit,
5. The lathe according to claim 4, wherein the distance display unit calculates and displays a distance to the no-entry area based on the current position and the no-entry area information when the target tool faces the workpiece in the drive shaft direction. 4. The lathe according to claim 3, wherein the tool position information display unit accepts an input of a machining length for machining the end face of the workpiece in the drive axis direction, and when the mode is the gripping mode, updates the tool position information based on the acquired position and the machining length.

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