JP2024032457A - Machine tools and machine tool control methods - Google Patents

Abstract

[Problem] A machine tool and machine tool that automatically adjusts the gap between the rotary guide bush and the bar when the opening degree of the rotary guide bush is adjusted by an adjustment nut and the rotary guide bush rotates synchronously with the main shaft. To provide a method for controlling machines. [Solution] A control device rotates the rotary guide bush drive motor based on the rotation angle of the rotary guide bush drive motor when the main shaft is rotated with the main shaft holding a bar material and the rotary guide bush drive motor is not excited. Guide bush opening degree is determined based on the rotation angle of the spindle drive motor when the guide bush body of the rotary guide bush is rotated with the bar held in place and the spindle drive motor not energized. It has a department. [Selection diagram] Figure 1

Description

The present invention relates to a machine tool that adjusts the gap between a bar and a rotary guide bush, and a method for controlling the machine tool.

2. Description of the Related Art Conventionally, machine tools are known that include a guide bush that is disposed in front of a main spindle to support and guide a bar held by the main spindle.
In order to process the bar material stably and with high precision, it is necessary to adjust the size of the gap between the bar material and the guide bush (also called guide bush opening adjustment). A technique for automatically performing adjustment is known (for example, Patent Document 1).

Japanese Patent Application Publication No. 7-328804

The machine tool described in Patent Document 1 uses an adjustment nut (also referred to as a drawbar) that is screwed into the guide bush when adjusting the opening degree of the guide bush.
Here, in Patent Document 1, the guide bush does not rotate synchronously with the main shaft, but in addition to preventing the bar from sticking to the guide bush, the guide bush is synchronized with the main shaft in order to avoid deterioration of the surface quality of the bar. Even in the case of a rotating rotary guide bush, it is desirable to automatically adjust the gap between the rotary guide bush and the bar in order to stably process the bar with high precision.

Therefore, the present invention solves the problems of the prior art as described above, and the purpose of the present invention is to adjust the opening degree of the rotary guide bush with an adjustment nut and to rotate the rotary guide bush synchronously with the main shaft. It is an object of the present invention to provide a machine tool and a control method for the machine tool that automatically adjust the gap between the rotary guide bush and the bar in the case of a structure in which

The invention according to claim 1 includes a main shaft that rotatably holds a bar, a main shaft drive motor that rotationally drives the main shaft, and a main shaft that rotates the bar advanced from the main shaft around a rotation axis and in the direction of the rotation axis. A rotary guide bush that allows and supports movement and rotates synchronously with the main shaft, a rotary guide bush drive motor that drives the rotary guide bush, and a rotation angle of the rotary guide bush drive motor or the main shaft drive motor. A machine tool comprising: an encoder; and a control device for controlling operations of the main shaft and the rotary guide bush; A guide bush main body that supports the bar by allowing rotation around the rotation axis and movement in the direction of the rotation axis while being freely rotatable, and a The guide bush main body is rotated to adjust the size of the gap, and the controller includes an adjustment nut that is threadedly engaged with the guide bush main body, and the control device holds the bar material with the main shaft and controls the rotation of the rotary guide bush. Based on the rotation angle of the rotary guide bush drive motor when the main shaft is rotated without exciting the drive motor, or a state in which the rotary guide bush holds the bar and the main shaft drive motor is not excited. The above-mentioned guide bush opening determining section determines the adjustment amount of the gap based on the rotation angle of the main shaft drive motor when the guide bush main body of the rotary guide bush is rotated. It is something that solves problems.

The invention according to claim 2 is, in addition to the configuration of the machine tool described in claim 1, wherein the encoder detects the rotation angle of the rotary guide bush drive motor, and the guide bush opening degree determining section detects the rotation angle of the rotary guide bush drive motor. The above-mentioned problem is solved by determining the adjustment amount of the gap based on the rotation angle of the rotary guide bush drive motor.

The invention according to claim 3 provides, in addition to the configuration of the machine tool according to claim 1 or 2, a rotating jig that engages with and rotates the adjustment nut of the rotary guide bush, By being attached to the bar, the above-mentioned problem is further solved.

The invention according to claim 4 has a main shaft that rotatably holds a bar, a main shaft drive motor that rotationally drives the main shaft, and a main shaft that rotates the bar advanced from the main shaft around a rotation axis and in the direction of the rotation axis. a rotary guide bush that allows and supports movement and rotates synchronously with the main shaft; a rotary guide bush drive motor that drives the rotary guide bush; an encoder that detects a rotation angle of the rotary guide bush drive motor; and the main shaft. and a control device that controls the operation of the rotary guide bush, wherein the rotary guide bush includes a guide bush holder fixed to a guide bush support base, and a guide bush holder that allows the rotary guide bush to freely rotate with respect to the guide bush holder while holding the rod. When adjusting the gap between the guide bush main body that allows rotation around the rotation axis and movement in the direction of the rotation axis, and the bar and the guide bush main body, the guide bush main body is rotated to adjust the gap. A method for controlling a machine tool having an adjustment nut that adjusts the size and is screwed into the guide bush main body, the method comprising: holding the bar on the main shaft; and rotating the main shaft around a rotation axis. a step of measuring the rotation angle of the rotary guide bush drive motor in a non-excited state caused by rotating the main shaft with the encoder; a step of determining the adjustment amount of the gap based on the determined amount of adjustment of the gap; and a step of rotating the main shaft around the rotation axis and rotating the guide bush body relative to the adjustment nut so as to achieve the determined adjustment amount of the gap. and, thereby solving the above-mentioned problems.

The invention according to claim 5 has a main shaft that rotatably holds a bar, a main shaft drive motor that rotationally drives the main shaft, and a main shaft that rotates the bar advanced from the main shaft around a rotation axis and in the direction of the rotation axis. a rotary guide bush that allows and supports movement and rotates synchronously with the main shaft; a rotary guide bush drive motor that drives the rotary guide bush; an encoder that detects the rotation angle of the main shaft drive motor; a control device for controlling the operation of a rotary guide bush, the rotary guide bush is configured to include a guide bush holder fixed to a guide bush support base, and a rotation axis of the bar while being rotatable relative to the guide bush holder; When adjusting the gap between the guide bush body that supports the guide bush body by allowing rotation around it and movement in the direction of the rotation axis, and the bar and the guide bush body, the size of the gap is adjusted by rotating the guide bush body. A control method for a machine tool having an adjusting nut threadedly engaged with the guide bush main body, the method comprising: holding the bar on the main shaft; and rotating the guide bush main body around a rotation axis. a step of measuring, with the encoder, a rotation angle of the spindle drive motor in a non-excited state caused by rotating the guide bush main body; , determining the adjustment amount of the gap, and rotating the guide bush main body around the rotation axis to rotate the guide bush main body with respect to the adjustment nut so that the determined gap adjustment amount is achieved. By including these, the above-mentioned problem is solved.

According to the machine tool of the invention according to claim 1, the rotation angle of the rotary guide bush drive motor when the control device rotates the main shaft in a state where the main shaft holds the bar and does not excite the rotary guide bush drive motor. Or, based on the rotation angle of the spindle drive motor when the guide bush body of the rotary guide bush is rotated with the bar stock held by the rotary guide bush and the spindle drive motor not energized. A main shaft drive motor or a rotary guide bush drive motor that is rotatable when either the main shaft drive motor or the rotary guide bush drive motor is rotationally driven by having a guide bush opening degree determining section that determines the amount of the guide bush opening. Since the variation in the rotation angle of the other is based only on the rotation of the bar accompanying the rotational drive of one of the spindle drive motor or rotary guide bush drive motor, when the spindle holding the bar is rotationally driven by the spindle drive motor, Compared to the case where the size of the gap between the rotary guide bush and the bar is adjusted based on the load of the main shaft drive motor, the signal-to-noise ratio is increased, and the opening degree of the rotary guide bush is adjusted by the adjustment nut, and the rotary guide bush is In the case of a structure that rotates synchronously with the main shaft, the gap between the rotary guide bush and the bar can be automatically adjusted with high precision.

According to the machine tool of the invention according to claim 2, in addition to the effects produced by the machine tool of the invention according to claim 1, the encoder detects the rotation angle of the rotary guide bush drive motor, and the guide bush opening degree determining section However, by determining the clearance adjustment amount based on the rotation angle of the rotary guide bush drive motor, the clearance adjustment amount is determined using the rotation angle of the guide bush body, which has a smaller moment of inertia than the main shaft. Therefore, the gap adjustment amount can be determined with higher accuracy than when the gap adjustment amount is determined based on the rotation angle of the main shaft drive motor.

According to the machine tool of the invention according to claim 3, in addition to the effects produced by the machine tool of the invention according to claim 1 or claim 2, the machine tool engages with the adjustment nut of the rotary guide bush and rotates this adjustment nut. Since the rotating jig is attached to the bar, the adjusting nut of the rotary guide bush rotates when the bar is rotated while the rotating jig is engaged with the adjustment nut. The gap between the bar and the bar can be adjusted automatically and with high precision.

According to the method for controlling a machine tool of the invention according to claim 4, the steps of holding the bar by the main shaft, rotating the main shaft around the rotation axis, and controlling the non-excited state caused by rotating the main shaft are performed. A step of measuring the rotation angle of the rotary guide bush drive motor with an encoder, a step of determining the gap adjustment amount based on the rotation angle of the rotary guide bush drive motor measured with the encoder, and a step of determining the determined gap adjustment amount. The rotary guide bush drive is rotatable when rotating the main shaft drive motor by including a step of rotating the main shaft around the rotation axis and rotating the guide bush body relative to the adjustment nut. Since the variation in the rotation angle of the motor is based only on the rotation of the bar accompanying the rotational drive of the spindle drive motor, the rotary Compared to the case where the size of the gap between the guide bush and the bar is adjusted, the signal-to-noise ratio is higher, and the opening degree of the rotary guide bush is adjusted with an adjustment nut, and the rotary guide bush rotates synchronously with the main shaft. , the gap between the rotary guide bush and the bar can be automatically adjusted with high precision.

According to the method for controlling a machine tool of the invention according to claim 5, the steps of holding the bar by the main shaft, rotating the guide bush body around the rotation axis, and controlling the excitation generated by rotating the guide bush body are performed. a step of measuring the rotation angle of the spindle drive motor with an encoder in a state where the spindle drive motor is not open; a step of determining the gap adjustment amount based on the rotation angle of the spindle drive motor measured with the encoder; and a step of determining the gap adjustment amount. By including the step of rotating the guide bush main body around the rotation axis and rotating the guide bush main body relative to the adjustment nut, the rotary guide bush drive motor can be rotated freely when the rotary guide bush drive motor is rotationally driven. Since the variation in the rotation angle of the spindle drive motor is based only on the rotation of the bar due to the rotational drive of the rotary guide bush drive motor, the load on the spindle drive motor when the spindle holding the bar is rotated by the spindle drive motor. Compared to the case where the size of the gap between the rotary guide bush and the bar is adjusted based on In the case of a structure, the gap between the rotary guide bush and the bar can be automatically adjusted with high precision.

1 is a schematic configuration diagram of an automatic lathe that is an embodiment of a machine tool according to the present invention. FIG. 3 is a configuration diagram of a rotary guide bush, a front main shaft, and a back main shaft. FIG. 3 is a perspective view of the adjustment nut shown in FIG. 2; FIG. 3 is a perspective view of the holding jig shown in FIG. 2; FIG. 3 is a perspective view of the rotating jig shown in FIG. 2; A flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush. 6A is a flowchart showing the preparation process shown in FIG. 6A. Flowchart showing the gap adjustment process shown in FIG. 6A. Schematic diagram showing the state in which the bar is inserted into the front main shaft. Schematic diagram showing the rod inserted into the rotary guide bush. FIG. 3 is a schematic diagram showing a state in which the front main shaft is advanced and the rotating jig and the adjustment nut are engaged. FIG. 3 is a schematic diagram showing a state in which the rotation jig and the adjustment nut are disengaged. FIG. 9 is a schematic diagram of the rotating jig and bar material shown in FIG. 8 viewed from behind. FIG. 3 is a schematic diagram showing a state in which the front main shaft is advanced and the rotating jig and the adjustment nut are engaged. FIG. 3 is a schematic diagram illustrating the process of adjusting the size of the gap between the bar and the guide bush body by rotating the front main shaft. A flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush. 11A is a flowchart showing the gap adjustment process shown in FIG. 11A. A flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush. 12A is a flowchart showing the preparation process shown in FIG. 12A. 12A is a flowchart showing the gap adjustment process shown in FIG. 12A. Schematic diagram showing the state in which the bar is inserted into the front main shaft. Schematic diagram showing the state in which the bar is inserted all the way to the back main shaft. FIG. 3 is a schematic diagram showing a state in which the back main shaft is retreated and the rotation jig and the adjustment nut are engaged. FIG. 3 is a schematic diagram showing a state in which the rotation jig and the adjustment nut are disengaged. FIG. 15 is a schematic diagram of the rotating jig and bar material shown in FIG. 14 viewed from the rear. FIG. 3 is a schematic diagram showing a state in which the back main shaft is retreated and the rotation jig and the adjustment nut are engaged. A schematic diagram illustrating the process of adjusting the size of the gap between the bar and the guide bush body by rotating the back main shaft. A flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush. 17A is a flowchart showing the gap adjustment process shown in FIG. 17A. A flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush. 18A is a flowchart showing the gap adjustment process shown in FIG. 18A. FIG. 3 is a schematic diagram showing a state in which the rotation jig and the adjustment nut are disengaged. FIG. 20 is a schematic diagram of the rotating jig and bar material shown in FIG. 19, viewed from the rear. FIG. 3 is a schematic diagram showing a state in which the back main shaft is retreated and the rotation jig and adjustment nut are engaged. FIG. 3 is a schematic diagram illustrating the process of adjusting the size of the gap between the bar and the guide bush body by rotating the front main shaft. A flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush. 23A is a flowchart showing the preparation process shown in FIG. 23A. 23A is a flowchart showing the gap adjustment process shown in FIG. 23A. FIG. 3 is a schematic diagram showing a state in which the rotation jig and the adjustment nut are disengaged. FIG. 24 is a schematic diagram of the rotating jig and bar material shown in FIG. 23 viewed from behind. FIG. 3 is a schematic diagram showing a state in which the front main shaft is advanced and the rotating jig and the adjustment nut are engaged. A schematic diagram illustrating the process of adjusting the size of the gap between the bar and the guide bush body by rotating the back main shaft.

The present invention includes a main shaft that rotatably holds a bar, a main shaft drive motor that rotationally drives the main shaft, and a support that allows the bar advanced from the main shaft to rotate around the rotation axis and move in the direction of the rotation axis. A rotary guide bush that rotates in synchronization with the main shaft, a rotary guide bush drive motor that drives this rotary guide bush, an encoder that detects the rotation angle of this rotary guide bush drive motor or the main shaft drive motor, and the main shaft and rotary guide bush. A machine tool comprising: a control device for controlling the operation of a rotary guide bush; a guide bush holder fixed to a guide bush support base; When adjusting the gap between the guide bush main body that allows rotation around the shaft and movement in the rotation axis direction, and the bar and the guide bush main body, the guide bush main body is rotated to adjust the size of the gap. The rotation of the rotary guide bush drive motor when the control device rotates the main shaft in a state in which the main shaft holds a bar and does not excite the rotary guide bush drive motor. The gap is determined based on the rotation angle of the spindle drive motor when the guide bush body of the rotary guide bush is rotated with the bar held by the rotary guide bush and the spindle drive motor not energized. Any specific embodiment may be used as long as it has a guide bush opening determining section that determines the amount of adjustment and automatically adjusts the gap between the rotary guide bush and the bar. do not have.

In addition, in the above machine tool, the step of holding the bar with the spindle, the step of rotating the spindle around the rotation axis, and the rotation angle of the rotary guide bush drive motor in the non-excited state caused by rotating the spindle. a step of measuring with an encoder, a step of determining the gap adjustment amount based on the rotation angle of the rotary guide bush drive motor measured with the encoder, and a step of rotating the main shaft around the rotation axis so that the determined gap adjustment amount is achieved. and a step of rotating the guide bush main body relative to the adjustment nut, and the gap between the rotary guide bush and the bar material is automatically adjusted. It doesn't matter if it's something.
Alternatively, in the above-mentioned machine tool, the step of holding the bar with the main shaft, the step of rotating the guide bush body around the rotation axis, and the step of rotating the main shaft drive motor in the non-excited state caused by rotating the guide bush main body. A step of measuring the rotation angle with an encoder, a step of determining the amount of gap adjustment based on the rotation angle of the spindle drive motor measured with the encoder, and a step of rotating the guide bush body to achieve the determined amount of gap adjustment. As long as it includes a step of rotating the guide bush body relative to an adjustment nut by rotating it around an axis, and automatically adjusts the gap between the rotary guide bush and the bar, what is the specific embodiment of it? It doesn't matter if it's something.

Hereinafter, a machine tool 100 that is an embodiment of the present invention will be described based on FIGS. 1 to 25B.

<1. Overview of machine tools＞
First, an overview of the machine tool 100 will be explained based on FIGS. 1 to 5.
FIG. 1 is a schematic diagram of an automatic lathe, which is an embodiment of a machine tool according to the present invention.

The machine tool 100 is an automatic lathe, and as shown in FIG. 1, includes a bed 110 placed on a floor F and having a rectangular shape in plan view.
Hereinafter, the direction perpendicular to the bed 110 will be referred to as the "Y direction," the longitudinal direction of the bed 110 in plan view will be referred to as the "Z direction," and the lateral direction of the bed 110 in plan view will be referred to as the "X direction."

The bed 110 includes a front main shaft 120 that rotatably holds the bar material W, a front main shaft feeding mechanism 130 that feeds the front main shaft 120 in the Z1 direction parallel to the Z direction, and a front main shaft 120 that rotates the bar material W advanced from the front main shaft 120. A rotary guide bush 140 that supports rotation about the rotation axis L and movement in the direction of the rotation axis L, a guide bush support 150 that is installed in front of the front main shaft 120 and supports the rotary guide bush 140, and a front A back main shaft 160 that is arranged to face the main shaft 120 and the rotary guide bush 140 and rotatably holds the bar W; and a back main shaft that sends the back main shaft 160 in the Z2 direction parallel to the Z direction and in the X2 direction parallel to the X direction. A feeding mechanism 170 is placed therein.

Here, the front main shaft 120 and the bar W are movable forward and backward in the Z1 direction, and "forward" in the front main shaft 120 and the bar W means the direction in which the front main shaft 120 and the bar W approach the back main shaft 160, “Backward” in the front main shaft 120 and the bar W means the direction in which the front main shaft 120 and the bar W move away from the back main shaft 160.
Further, "front" in the rotary guide bush 140 means a direction in which the rotary guide bush 140 approaches the back main shaft 160, and "rear" in the rotary guide bush 140 means a direction in which the rotary guide bush 140 moves away from the back main shaft 160. do.
The back main shaft 160 is movable forward and backward in the X2 direction and also in the Z2 direction, and "forward" in the back main shaft 160 means the direction in which the back main shaft 160 approaches the front main shaft 120, "Backwards" means the direction in which the back main axis 160 moves away from the front main axis 120.

The bar material W to be machined by the machine tool 100 is a long workpiece in the shape of a round bar, and is fed from the rear end of the front main spindle 120 using a push arrow of a bar feeder (not shown), and is fed through the front main spindle 120. It is rotatably supported around the rotation axis L by the rotary guide bush 140 and sent toward the back main shaft 160.
Note that a finger chuck for gripping the rear end of the bar material W is provided at the tip of the push arrow of the bar feeder.

The machine tool 100 also includes a control device 180 that controls the operations of the front spindle 120, the rotary guide bush 140, and the back spindle 160.

<2. Components of machine tools＞
Next, each component of the machine tool 100 described above will be explained in detail based on FIGS. 1 to 5.
FIG. 2 is a configuration diagram of the rotary guide bush, the front main shaft, and the back main shaft, FIG. 3 is a perspective view of the adjustment nut shown in FIG. 2, and FIG. 4 is a perspective view of the holding jig shown in FIG. 5 is a perspective view of the rotating jig shown in FIG. 2.

<2.1. Front spindle＞
As shown in FIG. 1, the front spindle 120 includes a headstock 121 that is mounted on the front spindle feed mechanism 130 and is movable in the Z1 direction, a front spindle main body 122 that is rotatably supported by the headstock 121, and a front spindle main body 122 that is rotatably supported by the headstock 121. It has a front main shaft drive motor 123 that rotationally drives the front main shaft main body 122, and an encoder 124 that detects the rotation angle of the front main shaft drive motor 123.

The front spindle main body 122 is supported by the headstock 121 with the Z1 direction shown in FIG. 1 as its axis, and as shown in FIG. It is possible.
The chuck 122a is arranged concentrically with the front main shaft body 122 and rotates together with the front main shaft main body 122.
That is, the rotation axis L of the bar W coincides with the rotation center of the front main shaft 120.

The front main shaft drive motor 123 is a so-called "electric motor" that has a stator and a rotor, generates a magnetic field by changing the rotation of either of them, and generates a driving force by the change in the magnetic field.

<2.2. Front spindle feed mechanism>
The front spindle feed mechanism 130 includes a Z1 rail 131 fixed to the bed 110 and extending in the Z1 direction, a Z1 slider 132 attached to the Z1 rail 131 and slidable along the Z1 direction, and a Z1 slider 132 that slides. Z1 motor 133.
A headstock 121 of the front spindle 120 is installed on the Z1 slider 132.

<2.3. Rotary guide bush>
As shown in FIG. 1, the rotary guide bush 140 is inserted into a guide bush support 150 having a rotary guide bush insertion hole 150a concentric with the front main shaft 120.

As shown in FIG. 2, the rotary guide bush 140 includes a hollow cylindrical guide bush holder 141 that is inserted and fixed into the rotary guide bush insertion hole 150a of the guide bush support 150, and the guide bush holder 141. a guide bush sleeve 142 inserted into the guide bush holder 141, a bearing 143 that is disposed between the guide bush holder 141 and the guide bush sleeve 142 and rotatably supports the guide bush sleeve 142 with respect to the guide bush holder 141; A cylindrical guide bush main body 144 inserted into the sleeve 142, an adjustment nut 145 screwed into a male thread 144a formed at the rear end portion of the guide bush main body 144, and an adjustment nut 145 inserted into the rear end side of the guide bush holder 141. a timing pulley 146 that is rotatable relative to the guide bush holder 141; a retaining nut 147 that engages with the guide bush sleeve 142 to prevent the timing pulley 146 from coming off; It has a flange 148 that prevents the pulley 146 from coming off, and a rotary guide bush drive motor 149 that rotationally drives the guide bush main body 144.

The guide bush holder 141 includes a hollow cylindrical guide bush holder main body 141a that is inserted into the rotary guide bush insertion hole 150a of the guide bush support stand 150, and a guide bush holder that is attached to the rear end side of the guide bush holder main body 141a. It has an annular bearing presser 141b that positions the bearing 143 in the front-rear direction together with the main body 141a.

A taper 142a is formed on the inner peripheral side of the front end portion of the guide bush sleeve 142, and the inner diameter gradually decreases toward the rear.
The guide bush sleeve 142 also has a through hole 142c formed in the radial direction into which a set screw 142b is screwed.
Furthermore, a key 142d that engages with the timing pulley 146 is embedded in the outer peripheral side of the rear end portion of the guide bush sleeve 142.

As shown in FIG. 2, the guide bush main body 144 supports and guides the bar W so as to allow rotation around the rotation axis L and movement in the direction of the rotation axis L.
A slot 144b extending in the Z direction is formed in the front end portion of the guide bush main body 144.

Further, a taper 144c corresponding to the taper angle of the taper 142a of the guide bush sleeve 142 is formed on the outer peripheral side of the front end portion of the guide bush main body 144, the outer diameter of which gradually decreases toward the rear.
A groove 144d extending rearward is formed at the rear of this taper 144c.
This groove 144d is formed to become gradually deeper toward the rear, and extends until it reaches the male thread 144a.

Further, a set screw 142b screwed into the through-hole 142c of the guide bushing sleeve 142 is inserted into the groove 144d.
Therefore, the set screw 142b and the groove 144d are engaged, and the guide bush main body 144 can move forward and backward relative to the guide bush sleeve 142 only in the Z direction, and the guide bush main body 144 is moved along the rotation axis L axis together with the guide bush sleeve 142. It can be rotated around.
That is, the guide bush main body 144 becomes rotatable with respect to the guide bush holder 141 when the set screw 142b and the groove 144d are engaged.

The adjustment nut 145 (also referred to as a drawbar) has a hollow cylindrical shape, is provided at the rear of the guide bush main body 144, and is rotatable with respect to the guide bush sleeve 142.
As shown in FIG. 2, a female thread 145a with a predetermined pitch is formed on the inner circumferential side of the front end portion of the adjustment nut 145. It matches.

Therefore, by rotating the adjustment nut 145 around the rotation axis L, the guide bush main body 144 moves forward and backward relative to the guide bush sleeve 142.
When the guide bush main body 144 retreats with respect to the guide bush sleeve 142, the taper 144c is pushed by the taper 142a, and the front end portion of the guide bush main body 144 is bent toward the bar W side by the slot 144b, so that the guide bush The opening degree of the front end portion of the main body 144 becomes smaller.
On the other hand, when the guide bush main body 144 moves forward relative to the guide bush sleeve 142, the pressure by the taper 142a is released and the front end portion of the guide bush main body 144 expands outward, so that the opening degree of the front end portion of the guide bush main body 144 becomes large. Become.

That is, the amount of displacement of the guide bush main body 144 in this embodiment (the opening degree of the rotary guide bush 140 and the opening degree of the front end portion of the guide bush main body 144) is determined by the amount of rotation with respect to the adjustment nut 145.
In other words, when adjusting the gap between the bar W and the guide bush main body 144, the adjustment nut 145 can rotate the guide bush main body 144 to adjust the size of the gap.

Further, as shown in FIG. 3, a plurality (for example, three) of engagement holes 145b1 are formed in the rear surface 145b of the adjustment nut 145.

The timing pulley 146 has a cylindrical shape, and is rotatably inserted into the rear end side of the bearing retainer 141b of the guide bush holder 141, as shown in FIG.

A keyway 146a that engages with a key 142d of the guide bushing sleeve 142 is formed on the inner peripheral side of the front end portion of the timing pulley 146.
Further, a belt positioning groove 146b is formed on the outer periphery of the timing pulley 146, and a timing belt V is wound around the belt positioning groove 146b.

A female thread formed on the inner circumferential side of the retaining nut 147 is threadedly engaged with a male thread formed on the outer circumferential side of the rear end portion of the guide bushing sleeve 142.
The female thread of the retaining nut 147 and the male thread of the guide bushing sleeve 142 are screwed together to prevent the timing pulley 146 from coming off rearward, as shown in FIG.

The flange 148 is an annular member, and as shown in FIG. 2, is fixed to the guide bush support base 150 with fixing bolts B.

The rotary guide bush drive motor 149 is an electric motor like the front main shaft drive motor 123, and has an encoder 149a that detects the rotation angle of the rotary guide bush drive motor 149.
Further, a timing pulley 149b around which a timing belt V is wound is attached to the tip of the rotary guide bush drive motor 149.

Therefore, when the rotary guide bush drive motor 149 rotates, the timing pulley 146 of the rotary guide bush 140 rotates via the timing belt V, the guide bush sleeve 142 rotates via the key 142d that engages with the timing pulley 146, and the guide The guide bush main body 144 rotates via a set screw 142b attached to the bush sleeve 142.

<2.4. Guide bush support stand>
Guide bush support stand 150 is fixed to bed 110.
As shown in FIG. 1, this guide bush support base 150 houses therein a timing pulley 149b attached to the tip of the rotary guide bush drive motor 149.

Further, a tool rest moving mechanism 151 on which a tool rest 152 is mounted is provided on the back main shaft 160 side of this guide bush support stand 150.
The turret moving mechanism 151 is capable of moving the turret 152 in the X direction and the Y direction.
A cutter 152a is mounted on the tool rest 152 with its tip facing the rotation axis L.
Therefore, by moving the front main shaft 120 in the direction of the rotation axis L and moving the tool rest 152 in the X direction or the Y direction, the bar material W can be processed with the cutter 152a.

<2.5. Rear spindle>
As shown in FIG. 1, the back spindle 160 includes a headstock 161 that is mounted on a back spindle feed mechanism 170 and is movable in the Z2 direction and the X2 direction, and a back spindle main body 162 that is rotatably supported by the headstock 161. , a back main shaft drive motor 163 that rotationally drives this back main shaft main body 162, and an encoder 164 that detects the rotation angle of this back main shaft drive motor 163.

The back spindle main body 162 is supported by the headstock 161 with the axis in the Z2 direction parallel to the Z1 direction shown in FIG. 1, and rotatably grips (holds) the bar W via the chuck 162a, as shown in FIG. It is possible.
The chuck 162a is configured concentrically with the back main shaft body 162, and is freely rotatable together with the back main shaft main body 162.

As shown in FIG. 2, a holding jig 165 for holding the bar W is removably attached to the chuck 162a.
As shown in FIGS. 2 and 4, this holding jig 165 includes a C-shaped annular main spindle mounting tool 165a that is attached to the back main spindle main body 162, and a C-shaped annular bar holder 165b that holds the bar W. , and a connecting bolt 165c that connects the main shaft mounting tool 165a and the bar holder 165b, and is a C-shaped member when viewed from the front main shaft 120 side.

As shown in FIG. 2, the spindle mounting tool 165a has an inner diameter that is approximately equal to the outer diameter of the back spindle main body 162.
In addition, as shown in FIG. 4, this spindle mounting tool 165a has a screw hole facing the through hole, which is inserted into a tightening bolt 165d through a through hole formed in a direction perpendicular to the circumferential direction of the main shaft mounting tool 165a. It is tightened to the back main shaft main body 162 by screwing it together with the main shaft body 162.
Thereby, the spindle mounting tool 165a rotates integrally with the back spindle main body 162.

A through hole extending in the Z2 direction is formed in the bar holder 165b.
The bar holder 165b is integrated with the spindle mounting tool 165a by inserting the coupling bolt 165c through this through hole and screwing into the screw hole formed in the front surface 165a1 of the spindle mounting tool 165a.
Furthermore, since the bar holder 165b is a C-shaped ring, the inner diameter φ of the bar holder 165b is variable, as shown in FIG.
The inner diameter of the bar holder 165b is such that the adjustment bolt 165e is inserted into a through hole formed in a direction perpendicular to the circumferential direction of the bar holder 165b and screwed into a threaded hole 165b1 facing the through hole. is adjusted.

The back main shaft drive motor 163 is an electric motor like the front main shaft drive motor 123.

<2.6. Rear spindle feed mechanism＞
As shown in FIG. 1, the back main shaft feeding mechanism 170 is composed of an X2 direction feeding structure 171 placed on the bed 110 and a Z2 direction feeding structure 172 placed on this X2 direction feeding structure 171. .

The X2 direction feeding structure 171 includes an X2 rail 171a that is fixed to the bed 110 and extends in the X2 direction, an X2 slider 171b that is attached to the X2 rail 171a and is slidable along the X2 direction, and slides the X2 slider 171b. It has an X2 motor 171c.

The Z2 direction feeding structure 172 includes a Z2 rail 172a fixed to the X2 slider 171b and extending in the Z2 direction, a Z2 slider 172b attached to the Z2 rail 172a and slidable along the Z2 direction, and a Z2 slider 172b that slides the Z2 slider 172b. It has a Z2 motor 172c to
A headstock 161 of the back spindle 160 is installed on the Z2 slider 172b.

<2.7. Control device＞
The rotation of the front main shaft 120, the rotary guide bush 140, and the back main shaft 160, and the movement of the front main shaft feeding mechanism 130 and the back main shaft feeding mechanism 170 are controlled by a control device 180.
The control device 180 includes a control unit 181 and an input unit 182, which are connected via a bus.

The control unit 181 includes a CPU, a memory, etc., and loads various programs and data stored in, for example, a ROM into a RAM, and executes the programs.
That is, the operation of the machine tool 100 is controlled by a program loaded into the control unit 181.
Note that the rotation of the front spindle 120, rotary guide bush 140, and back spindle 160, the movement of the front spindle feed mechanism 130, and the back spindle feed mechanism 170, etc. can be set by a program or by input to the input unit 182. .

Further, the control unit 181 includes a motor control section 181a, a guide bush opening determining section 181b, and a data table 181c.

For example, when adjusting the gap between the bar W and the rotary guide bush 140 (that is, the guide bush main body 144), the motor control unit 181a controls the front main shaft drive motor 123, the back main shaft drive motor 163, and the rotary guide bush drive motor. 149, controls the operation of Z1 motor 133 and Z2 motor 172c.
Further, the motor control unit 181a of the control device 180 synchronizes the rotational drive of the front main shaft drive motor 123 or the rotational drive of the back main shaft drive motor 163 with the rotational drive of the rotary guide bush drive motor 149.

The guide bush opening determination unit 181b determines the rotation angle of the front main shaft drive motor 123 measured by the encoder 124, the rotation angle of the rotary guide bush drive motor 149 measured by the encoder 149a, or the rotation angle of the rear main shaft drive motor 163 measured by the encoder 164. Based on any one of the rotation angles, the amount of adjustment of the gap between the bar W and the guide bush main body 144 is determined with reference to the data table 181c.
More specifically, the guide bush opening determining unit 181b determines the rotation angle of the front main shaft drive motor 123, the rotary guide bush drive motor 149, or the rear main shaft drive motor 163. The size of the gap between the bar material W and the guide bush main body 144 is estimated, the amount of difference between the estimated value of the size of this gap and the optimal size of the gap is calculated, and the rotation of the back main shaft 160 is performed based on this amount of difference. In other words, the adjustment amount of the gap between the bar material W and the guide bush main body 144 is determined.

The data table 181c contains any one of the rotation angle of the front spindle drive motor 123, the rotation angle of the rotary guide bush drive motor 149, or the rotation angle of the back spindle drive motor 163, depending on the material and diameter of the bar W. , data corresponding to the size of the gap between the bar W and the guide bush main body 144 are stored.

<2.8. Rotating jig>
As shown in FIG. 2, the machine tool 100 includes a rotating jig 190 that rotates an adjustment nut 145 that adjusts the size of the gap between the bar W and the guide bush main body 144.

The rotating jig 190 has a C-shaped annular shape as shown in FIG. 5, and a bar W is inserted therein as shown in FIG.
The rotating jig 190 has a variable inner diameter, similar to the bar holder 165b.
The inner diameter of the rotating jig 190 is adjusted by inserting a tightening bolt 191 into a through hole formed in a direction perpendicular to the circumferential direction of the rotating jig 190 and screwing it into a screw hole 190a facing the through hole. Ru.

Furthermore, an engagement pin 192 that engages with the engagement hole 145b1 of the adjustment nut 145 of the rotary guide bush 140 is provided on the front surface 190b of the rotating jig 190.

<3. Gap adjustment procedure>
Next, based on FIGS. 1 to 25B, the size of the gap between the bar W and the rotary guide bush 140, that is, the gap between the bar W and the guide bush main body 144, is determined by the machine tool 100 according to an embodiment of the present invention. The adjustment procedure will be explained using six specific examples.
Note that each specific example shown below is just an example, and the procedure for adjusting the size of the gap between the bar material W and the guide bush main body 144 is not limited to the following specific examples.

<3.1. First example: Using the rotation angle of the rotary guide bush drive motor>
First, a first specific example using the front main shaft 120 and the rotary guide bush 140 of the machine tool 100 will be described based on FIGS. 6A to 10B.
FIG. 6A is a flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush, FIG. 6B is a flowchart showing the preparation process shown in FIG. 6A, and FIG. 6C is a flowchart showing the gap adjustment process shown in FIG. 6A. FIG. 7A is a schematic diagram showing a state in which the bar is inserted into the front main shaft, FIG. 7B is a schematic diagram in which the bar is inserted up to the rotary guide bush, and FIG. 7C is a schematic diagram in which the front main shaft is advanced. FIG. 8 is a schematic diagram showing a state in which the rotating jig and the adjusting nut are engaged, FIG. 8 is a schematic diagram showing a state in which the rotating jig and the adjusting nut are disengaged, and FIG. FIG. 10A is a schematic diagram showing the rotating jig and the bar material shown in FIG. FIG. 2 is a schematic diagram illustrating a process of adjusting the size of the gap between the bar and the guide bush main body by rotating the front main shaft.

<3.1.1. Preparation process>
(Step S10)
First, the machine tool 100 performs a preparation process shown in FIG. 6B.

(Step S11)
In the preparation process, the bar material W is inserted from the rear end of the front main shaft 120 using a push arrow of a bar feeder (not shown) (see FIG. 7A), and then inserted into the rotating jig 190 and the rotary guide bush 140 in this order.
At this time, the rotation center of the front main shaft 120 is made to coincide with the rotation center of the rotary guide bush 140 (guide bush main body 144).

(Step S12)
Next, as shown in FIG. 7B, the rotating jig 190 is tightened and fixed to the bar W, and the rotating jig 190 and the bar W are rotated around the rotation axis L as a unit.
Note that when the rotating jig 190 is fixed to the bar W, the bar W projects forward from the rotary guide bush 140.

(Step S13)
Next, as shown in FIG. 7C, the front main shaft 120 grips (holds) the bar W, moves the front main shaft 120 forward, and connects the engagement pin 192 of the rotating jig 190 to the adjustment nut 145 of the rotary guide bush 140. into the engagement hole 145b1.
By inserting the engagement pin 192 of the rotating jig 190 into the engagement hole 145b1 of the adjustment nut 145 of the rotary guide bush 140, the orientation of the adjustment nut 145, that is, the position in the rotational direction of the guide bush main body 144 and the front main axis The rotational direction position of 120 is determined at a predetermined position (hereinafter referred to as "reference angular position").

Note that when the front main shaft 120 moves forward, if the engagement hole 145b1 of the adjustment nut 145 and the engagement pin 192 of the rotation jig 190 are misaligned in the rotational direction, the engagement hole 145b1 of the adjustment nut 145 and the rotation jig 190 are misaligned. The bar W (i.e., the front main shaft 120 holding the bar W) or the adjustment nut 145 (i.e., the guide bush main body 144) is rotated until the engagement pin 192 of the tool 190 directly faces each other.

(Step S14)
Next, the front main shaft 120 is retreated from the rotary guide bush 140 until the rotating jig 190 is disengaged from the adjustment nut 145, resulting in the state shown in FIG. 8.

<3.1.2. Inspection process＞
(Step S20)
Next, in this state, the excitation of the rotary guide bush drive motor 149 is cut off.
Therefore, the guide bush main body 144 is rotatable with respect to the bar W.

(Step S21)
Then, the front main shaft 120 is rotated by a predetermined angle in a predetermined direction.
That is, the front main shaft 120 is rotated to rotate the bar W by a predetermined angle θ from the reference angular position P to the angular position P1, as shown in FIG.

(Step S22)
When the bar W is rotated by a predetermined angle θ from the reference angular position P to the angular position P1, the guide bush main body 144 can freely rotate with respect to the bar W because the rotary guide bush drive motor 149 is de-energized. It becomes.

Therefore, as described above, if the gap between the bar W and the guide bush main body 144 is narrow when the bar W rotates by the predetermined angle θ from the reference angular position P to the angular position P1, the bar W and the guide bush main body 144, and this contact with the bar W may cause the guide bush main body 144 to rotate with the bar W.
As the guide bush main body 144 rotates, the guide bush sleeve 142, which is integrated with the guide bush main body 144 by a set screw 142b, rotates, and the timing pulley 146 engages with a key 142d embedded in the guide bush sleeve 142. rotates.
Then, the rotation of the timing pulley 146 is transmitted from the timing belt V to the timing pulley 149b of the rotary guide bush drive motor 149, and the rotary guide bush drive motor 149 rotates.
Conversely, if the gap between the bar W and the guide bush main body 144 is too large when the bar W rotates by the predetermined angle θ from the reference angular position P to the angular position P1, the bar W and the guide bush main body 144 may There may be no contact and the guide bush main body 144, that is, the rotary guide bush drive motor 149 may not rotate.

Therefore, in step S22, while the front main shaft 120 holds the bar W and the excitation of the rotary guide bush drive motor 149 is cut off, the rotation angle of the guide bush main body 144, that is, the rotary guide bush drive motor 149 is set to a predetermined angle. Determine whether it is within the range.

When the rotation angle of the rotary guide bush drive motor 149 falls within a predetermined angle range, the gap between the bar W and the guide bush main body 144 is assumed to be the optimal gap size, and the gap between the bar W and the guide bush The adjustment of the size of the gap with the main body 144 is completed.

On the other hand, if the rotation angle of the rotary guide bush drive motor 149 is less than the lower limit of the predetermined angle range, the gap between the bar W and the guide bush body 144 is too large, and the gap between the bar W and the guide bush body 144 is too large. Since it is necessary to adjust the size of the gap, the process advances to step S23.
Further, if the rotation angle of the rotary guide bush drive motor 149 exceeds the upper limit of the predetermined angle range, the size of the gap between the bar W and the guide bush body 144 is too small. Since it is necessary to adjust the size of the gap, the process advances to step S23.

(Step S23)
In step S23, the front main shaft 120 is rotated to rotate the bar W from the angular position P1 until it returns to the reference angular position P (that is, rotated in the opposite direction to step S21).

(Step S24)
Next, the rotary guide bush drive motor 149 is excited.
As a result, a holding torque acts on the rotary guide bush drive motor 149, and this holding torque affects the timing pulley 146 of the rotary guide bush 140, so that even if an attempt is made to rotate the timing pulley 146, it will not rotate.

(Step S25)
Next, the rotary guide bush drive motor 149 is rotated, and the position of the guide bush main body 144 in the rotation direction is set at the reference angle determined in step S13 so that the rotation jig 190 can be inserted into the adjustment nut 145 of the rotary guide bush 140. Return to position.

<3.1.3. Gap adjustment process＞
(Step S30)
Next, the process proceeds to step S30, and various steps of a gap adjustment process for adjusting the size of the gap between the bar W and the guide bush main body 144 shown in FIG. 6C are performed.

(Step S31)
First, the front main shaft 120 is advanced until the rotating jig 190 is inserted into the adjustment nut 145 of the rotary guide bush 140 to bring it into the state shown in FIG. 10A.

(Step S32)
In this state, as shown in FIG. 10B, the front main shaft 120 is rotated by a predetermined amount in a predetermined direction based on the output result from the guide bush opening determining section 181b.
This rotation of the front main shaft 120 rotates the bar W, and a rotating jig 190 fixed to the bar W is rotated by a predetermined amount in a predetermined direction.

Here, since the timing pulley 146 does not rotate, the guide bush sleeve 142 that is engaged with the timing pulley 146 through the key 142d and the guide bush main body 144 that is engaged with this guide bush sleeve 142 through the set screw 142b also do not rotate. .
However, when the rotating jig 190 rotates, the adjusting nut 145 that engages with the rotating jig 190 rotates, and since the adjusting nut 145 cannot move in the Z direction due to the guide bush sleeve 142 and the rotating jig 190, this adjusting nut The guide bush body 144 screwed into the guide bush body 145 moves forward and backward in the Z direction with respect to the guide bush sleeve 142 and the adjustment nut 145 in accordance with the rotational direction of the adjustment nut 145, thereby reducing the gap between the bar W and the guide bush body 144. The size of is adjusted.

(Step S33)
After the size of the gap between the bar W and the guide bush main body 144 has changed by a predetermined amount, the front main shaft 120 is moved back, the rotating jig 190 is separated from the adjustment nut 145 of the rotary guide bush 140, and the process returns to step S20. .

Thereafter, the steps described above are repeated as appropriate until the rotation angle of the rotary guide bush drive motor 149 falls within the predetermined angle range.

<3.2. Second specific example: Using the rotation angle of the front spindle drive motor>
Next, a second specific example using the front main shaft 120 and the rotary guide bush 140 of the machine tool 100 will be described based on FIGS. 8, 11A, 11B, etc.
FIG. 11A is a flowchart showing a procedure for adjusting the size of the gap between the bar and the rotary guide bush, and FIG. 11B is a flowchart showing the gap adjustment process shown in FIG. 11A.
Note that the second specific example includes some of the same steps as the first specific example, so the description of the steps similar to the first specific example will be omitted by using the same step numbers as the first specific example. do.

<3.2.1. Inspection process>
(Step S20A)
After the preparation process (step S10), the state shown in FIG. 8 is reached.
In this state, the excitation of the front main shaft drive motor 123 is cut off.
Therefore, the front main shaft main body 122 and the front main shaft drive motor 123 are rotatable with respect to the bar W.

(Step S21A)
Then, the rotary guide bush drive motor 149 is driven to rotate the guide bush main body 144 of the rotary guide bush 140 in a predetermined direction by a predetermined angle (that is, by a predetermined angle θ from the reference angular position P to the angular position P1).

(Step S22A)
If the gap between the bar W and the guide bush main body 144 is narrow when the guide bush main body 144 rotates by a predetermined angle θ from the reference angular position P to the angular position P1, the bar W and the guide bush main body 144 may come into contact with each other. Due to this contact with the bar W, the bar W may be rotated with the guide bush main body 144.
This rotation of the bar W causes the front spindle body 122 that grips the bar W to rotate, and the front spindle drive motor 123 that rotates the front spindle body 122 to rotate.
Conversely, if the gap between the bar W and the guide bush main body 144 is too large when the guide bush main body 144 rotates by the predetermined angle θ from the reference angular position P to the angular position P1, the bar W and the guide bush main body 144 may may not make contact and the bar W, that is, the front main shaft drive motor 123 may not rotate.

Therefore, in step S22A, the rotation angle of the front main shaft drive motor 123 is within a predetermined angle range while the bar W is held by the guide bush main body 144 of the rotary guide bush 140 and the excitation of the front main shaft drive motor 123 is cut off. Determine whether or not.

When the rotation angle of the front main shaft drive motor 123 falls within a predetermined angle range, the gap between the bar W and the guide bush main body 144 is assumed to be the optimum gap size, and the gap between the bar W and the guide bush main body 144 is The adjustment of the size of the gap with 144 is completed.

On the other hand, if the rotation angle of the front main shaft drive motor 123 is less than the lower limit of the predetermined angle range, the gap between the bar W and the guide bush body 144 is too large. Since the gap size needs to be adjusted, the process advances to step S23A.
Furthermore, if the rotation angle of the front main shaft drive motor 123 exceeds the upper limit of the predetermined angle range, the size of the gap between the bar W and the guide bush body 144 is too small. Since the gap size needs to be adjusted, the process advances to step S23A.

(Step S23A)
In step S23A, the rotary guide bush drive motor 149 is rotated to rotate the guide bush main body 144 from the angular position P1 until it returns to the reference angular position P (that is, rotated in the opposite direction to step S21A).

(Step S24A)
Next, the front main shaft drive motor 123 is excited.
As a result, a holding torque acts on the front main shaft drive motor 123 and the rotary guide bush drive motor 149, and even if the front main shaft drive motor 123 is driven, the bar W is rotated by the holding torque of the rotary guide bush drive motor 149. Even if I try to turn it, it won't rotate.

(Step S25A)
Next, the front main shaft drive motor 123 is rotated to position the front main shaft 120 in the rotational direction at the reference angular position P determined in step S13 so that the rotating jig 190 can be inserted into the adjustment nut 145 of the rotary guide bush 140. Return to .

<3.2.2. Gap adjustment process>
(Step S30A)
Next, the process proceeds to step S30A, and various steps of the gap adjustment step shown in FIG. 11B are performed.

(Step S32A)
After carrying out step S31, the guide bush main body 144 is rotated by a predetermined amount in a predetermined direction based on the output result from the guide bush opening determining section 181b.

Here, since the bar W is no longer rotating, the rotating jig 190 is also not rotating, and therefore the adjusting nut 145 is also not rotating.
Therefore, when the guide bush main body 144 is rotated by a predetermined amount in a predetermined direction, the guide bush main body 144 advances and retreats in the Z direction with respect to the guide bush sleeve 142 and the adjustment nut 145 in accordance with the rotation direction of the adjustment nut 145, and the rod The size of the gap between the material W and the guide bush main body 144 is adjusted.

After carrying out step S33, the above-described steps are repeated as appropriate until the rotation angle of the front main shaft drive motor 123 falls within a predetermined angle range.

<3.3. Third specific example: Using the rotation angle of the rotary guide bush drive motor>
Next, a third specific example using the back main shaft 160 and the rotary guide bush 140 of the machine tool 100 will be described based on FIGS. 12A to 16B.
FIG. 12A is a flowchart showing a procedure for adjusting the size of the gap between the bar and the rotary guide bush, FIG. 12B is a flowchart showing the preparation process shown in FIG. 12A, and FIG. 12C is a flowchart showing the gap adjustment process shown in FIG. 12A. FIG. 13A is a schematic diagram showing a state in which a bar is inserted into the front main shaft, FIG. 13B is a schematic diagram in a state in which the bar is inserted up to the back main shaft, and FIG. 13C is a schematic diagram in which the back main shaft is retreated. FIG. 14 is a schematic diagram showing a state in which the rotating jig and the adjusting nut are engaged, FIG. 14 is a schematic diagram showing a state in which the rotating jig and the adjusting nut are disengaged, and FIG. FIG. 16A is a schematic diagram showing the rotating jig and the bar material shown in FIG. It is a schematic diagram explaining the process of rotating the back main shaft and adjusting the size of the gap between the bar and the guide bush main body.
Note that the third specific example includes some of the same steps as the first specific example, so the description of the steps similar to the first specific example will be omitted by using the same step numbers as the first specific example. do.

<3.3.1. Preparation process>
(Step S100)
First, the machine tool 100 performs a preparation process shown in FIG. 12B.

(Step S110)
In the preparation process, the bar W is pushed by a bar feeder (not shown) while the rotation center of the back main shaft 160 is aligned with the rotation center of the front main shaft 120 and the rotation center of the rotary guide bush 140 (guide bush main body 144). Using an arrow, insert from the rear end of the front main shaft 120 (see FIG. 13A), and then insert the rotating jig 190, rotary guide bush 140, and back main shaft 160 in this order.

(Step S130)
After carrying out step S12, as shown in FIG. 13B, the holding jig 165 is tightened to the bar W by the adjustment bolt 165e of the holding jig 165 of the back main shaft 160, and is gripped (held) by the back main shaft 160.

(Step S140)
Next, as shown in FIG. 13C, with the back main shaft 160 gripping the bar W, the back main shaft 160 is moved backward and the engagement pin 192 of the rotating jig 190 is engaged with the adjustment nut 145 of the rotary guide bush 140. Insert into matching hole 145b1.
By inserting the engagement pin 192 of the rotating jig 190 into the engagement hole 145b1 of the adjustment nut 145 of the rotary guide bush 140, the orientation of the adjustment nut 145, that is, the position of the guide bush main body 144 in the rotational direction and the back main axis. 160 in the rotational direction is determined at a predetermined position (hereinafter referred to as "reference angular position").

Note that when the back main shaft 160 retreats, if the engagement hole 145b1 of the adjustment nut 145 and the engagement pin 192 of the rotation jig 190 are misaligned in the rotational direction, the engagement hole 145b1 of the adjustment nut 145 and the rotation jig 190 are out of alignment. Rotate the bar W (i.e., the back main shaft 160 holding the bar W) or the adjustment nut 145 (i.e., the guide bush main body 144) until the engagement pin 192 of the tool 190 directly faces each other.

(Step S150)
Next, the back main shaft 160 is advanced toward the rotary guide bush 140 until the rotating jig 190 is disengaged from the adjustment nut 145, resulting in the state shown in FIG. 14.

<3.3.2. Inspection process>
(Step S210)
Next, after carrying out step S20, the back main shaft 160 is rotated by a predetermined angle in a predetermined direction.
That is, by rotating the back main shaft 160, the bar W is rotated by a predetermined angle θ from the reference angular position P to the angular position P1, as shown in FIG.

(Step S220)
When the bar W is rotated by a predetermined angle θ from the reference angular position P to the angular position P1, the guide bush main body 144 can freely rotate with respect to the bar W because the rotary guide bush drive motor 149 is de-energized. It becomes.

In this state, as in the first specific example, the rotation of the bar W may cause the rotary guide bush drive motor 149 to rotate or not.
Therefore, in step S220, the rotation angle of the guide bush main body 144, that is, the rotary guide bush drive motor 149 is set to a predetermined angle while the bar W is held by the back main shaft 160 and the excitation of the rotary guide bush drive motor 149 is cut off. Determine whether it is within the range.

When the rotation angle of the rotary guide bush drive motor 149 falls within a predetermined angle range, the gap between the bar W and the guide bush main body 144 is assumed to be the optimal gap size, and the gap between the bar W and the guide bush The adjustment of the size of the gap with the main body 144 is completed.

On the other hand, if the rotation angle of the rotary guide bush drive motor 149 is less than the lower limit of the predetermined angle range, and if the rotation angle of the rotary guide bush drive motor 149 exceeds the upper limit of the predetermined angle range, the first specific example Similarly, it is necessary to adjust the size of the gap between the bar W and the guide bush main body 144, and the process proceeds to step S230.

(Step S230)
In step S230, the back main shaft 160 is rotated to rotate the bar W from the angular position P1 until it returns to the reference angular position P (that is, rotated in the opposite direction to step S210).
After that, the process advances to step S24 and step S25.

<3.3.3. Gap adjustment process＞
(Step S300)
Next, the process proceeds to step S300, and various steps of a gap adjustment process for adjusting the size of the gap between the bar W and the guide bush main body 144 shown in FIG. 12C are performed.

(Step S310)
First, the back main shaft 160 is moved back until the rotating jig 190 is inserted into the adjustment nut 145 of the rotary guide bush 140, resulting in the state shown in FIG. 16A.

(Step S320)
Then, as shown in FIG. 16B, while the bar W is held by the back main shaft 160, the back main shaft 160 is rotated by a predetermined amount in a predetermined direction based on the output result from the guide bush opening determining section 181b.
The rotation of the back main shaft 160 causes the bar W to rotate, and the rotating jig 190 fixed to the bar W to rotate by a predetermined amount in a predetermined direction, and as in the first example, the bar W and the guide The size of the gap with the bush main body 144 is adjusted.

(Step S330)
After the size of the gap between the bar W and the guide bush main body 144 changes by a predetermined amount, the back main shaft 160 is advanced to disengage the rotating jig 190 from the adjustment nut 145 of the rotary guide bush 140, and the process returns to step S200. .

Thereafter, the steps described above are repeated as appropriate until the rotation angle of the rotary guide bush drive motor 149 falls within the predetermined angle range.

<3.4. Fourth example: Using the rotation angle of the back spindle drive motor>
Next, a fourth specific example using the back main shaft 160 and the rotary guide bush 140 of the machine tool 100 will be described based on FIGS. 14, 17A, 17B, etc.
FIG. 17A is a flowchart showing a procedure for adjusting the size of the gap between the bar and the rotary guide bush, and FIG. 17B is a flowchart showing the gap adjustment process shown in FIG. 17A.
Note that the fourth specific example includes a part of the same steps as the second specific example and the third specific example, so the steps similar to the second specific example and the third specific example will be explained in the second specific example. As the step numbers are the same as those in the specific example and the third specific example, the explanation will be omitted.

<3.4.1. Inspection process>
(Step S200A)
After the preparation process (step S100), the state shown in FIG. 14 is reached.
In this state, the excitation of the back main shaft drive motor 163 is cut off.
Therefore, the back main shaft main body 162 and the back main shaft drive motor 163 are rotatable with respect to the bar W.
Next, step S21A is performed.

(Step S220A)
If the gap between the bar W and the guide bush main body 144 is narrow when the guide bush main body 144 rotates by the predetermined angle θ from the reference angular position P to the angular position P1 in step S21A, the bar W and the guide bush main body 144 This contact with the bar W may cause the bar W to rotate with the guide bush main body 144 .
This rotation of the bar W causes the back main shaft main body 162 that grips the bar W to rotate, and the back main shaft drive motor 163 that rotationally drives the back main shaft main body 162 rotates.
Conversely, if the gap between the bar W and the guide bush main body 144 is too large when the guide bush main body 144 rotates by the predetermined angle θ from the reference angular position P to the angular position P1, the bar W and the guide bush main body 144 may may not make contact and the bar W, that is, the back main shaft drive motor 163 may not rotate.

Therefore, in step S220A, the rotation angle of the back main shaft drive motor 163 falls within a predetermined angle range while the bar W is held by the guide bush main body 144 of the rotary guide bush 140 and the excitation of the back main shaft drive motor 163 is cut off. Determine whether or not.

When the rotation angle of the back main shaft drive motor 163 falls within a predetermined angle range, the gap between the bar W and the guide bush main body 144 is assumed to be the optimal gap size, and the gap between the bar W and the guide bush main body 144 is The adjustment of the size of the gap with 144 is completed.

On the other hand, if the rotation angle of the back main shaft drive motor 163 is less than the lower limit of the predetermined angle range, the gap between the bar W and the guide bush main body 144 is too large. Since the gap size needs to be adjusted, the process advances to step S23A.
Furthermore, if the rotation angle of the back main shaft drive motor 163 exceeds the upper limit of the predetermined angle range, the size of the gap between the bar W and the guide bush body 144 is too small. Since the gap size needs to be adjusted, the process advances to step S23A.

(Step S240A)
Next to step S23A, the back main shaft drive motor 163 is excited.
As a result, a holding torque acts on the back main shaft drive motor 163 and the rotary guide bush drive motor 149, and even if the back main shaft drive motor 163 is driven, the bar W is rotated by the holding torque of the rotary guide bush drive motor 149. Even if I try to turn it, it won't rotate.

(Step S250A)
Next, the back main shaft drive motor 163 is rotated to bring the rotational position of the back main shaft 160 to the initial position determined in step S130 so that the rotating jig 190 can be inserted into the adjustment nut 145 of the rotary guide bush 140. return.

<3.4.2. Gap adjustment process＞
(Step S300A)
Next, the process proceeds to step S300A, and various steps of the gap adjustment step shown in FIG. 17B are performed.

After performing steps S310, S32A, and S330, the above-described steps are repeated as appropriate until the rotation angle of the back main shaft drive motor 163 falls within a predetermined angle range.

<3.5. Fifth specific example: Using the rotation angle of the rotary guide bush drive motor>
Next, a fifth specific example using the front spindle 120, rotary guide bush 140, and back spindle 160 of the machine tool 100 will be described based on FIGS. 13, 18A to 21B.
FIG. 18A is a flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush, FIG. 18B is a flowchart showing the gap adjustment process shown in FIG. 18A, and FIG. FIG. 20 is a schematic diagram showing the rotating jig and bar shown in FIG. 19 viewed from the rear, and FIG. 21A is a schematic diagram showing the rotating jig and the bar shown in FIG. FIG. 21B is a schematic diagram showing a state in which the front main shaft is rotated to adjust the size of the gap between the bar and the guide bush main body.
Note that the fifth specific example includes some of the same procedures as the first specific example and the third specific example, so the steps similar to the first specific example and the third specific example are similar to those in the first specific example. As the step numbers are the same as those in the specific example and the third specific example, the explanation will be omitted.

<3.5.1. Preparation process＞
(Step S100)
First, the machine tool 100 performs a preparation step S100.

Note that when the back main shaft 160 moves backward, if the engagement hole 145b1 of the adjustment nut 145 and the engagement pin 192 of the rotating jig 190 are misaligned in the rotational direction, the grip of the bar W is moved from the back main shaft 160 to the front. Switch to the main shaft 120, and press the bar W (i.e., the front main shaft 120 holding the bar W) or the adjustment nut 145 ( That is, the guide bush main body 144) is rotated.

<3.5.2. Inspection process>
(Step S2100)
After step S100 is executed and the state shown in FIG. 19 is achieved, step S200 is executed, the grip of the bar W is switched from the back main shaft 160 to the front main shaft 120, and the front main shaft 120 is rotated by a predetermined angle in a predetermined direction. .
That is, the front main shaft 120 is rotated to rotate the bar W by a predetermined angle θ from the reference angular position P to the angular position P1, as shown in FIG.

Thereafter, the process proceeds to step S22, and if the rotation angle of the rotary guide bush drive motor 149 is within the predetermined angle range, it is assumed that the gap between the bar W and the guide bush main body 144 is the optimum gap size. , the adjustment of the size of the gap between the bar W and the guide bush main body 144 is completed.
In step S22, if the rotation angle of the rotary guide bush drive motor 149 is less than the lower limit of the predetermined angle range, and if the rotation angle of the rotary guide bush drive motor 149 exceeds the upper limit of the predetermined angle range, the first concrete As in the example, it is necessary to adjust the size of the gap between the bar W and the guide bush main body 144, and the process proceeds to steps S23, S24, and S25.

<3.5.3. Gap adjustment process>
(Step S3000)
After carrying out step S25, the process proceeds to step S3000, and various steps of a gap adjustment process for adjusting the size of the gap between the bar material W and the guide bush main body 144 shown in FIG. 18B are performed.

(Step S3100)
First, the grip of the bar W is switched from the front main shaft 120 to the back main shaft 160, and the back main shaft 160 is moved backward until the rotating jig 190 is inserted into the adjustment nut 145 of the rotary guide bush 140, and the state shown in FIG. 21A is obtained. do.

(Step S3200)
Then, as shown in FIG. 21B, the gripping of the bar W is switched from the back main shaft 160 to the front main shaft 120, and the front main shaft 120 is rotated by a predetermined amount in a predetermined direction based on the output result from the guide bush opening determining section 181b. let
This rotation of the front main shaft 120 causes the bar W to rotate, and the rotating jig 190 fixed to the bar W to rotate by a predetermined amount in a predetermined direction, and as in the first example, the bar W and the guide The size of the gap with the bush main body 144 is adjusted.

(Step S3300)
After the size of the gap between the bar W and the guide bush main body 144 changes by a predetermined amount, the grip of the bar W is switched from the front main shaft 120 to the back main shaft 160, and the back main shaft 160 is advanced to rotate the rotating jig 190. is removed from the adjustment nut 145 of the rotary guide bush 140, and the process returns to step S200.

Thereafter, the steps described above are repeated as appropriate until the rotation angle of the rotary guide bush drive motor 149 falls within the predetermined angle range.

<3.6. Sixth specific example: Using the rotation angle of the rotary guide bush drive motor>
First, a sixth specific example using the front spindle 120, rotary guide bush 140, and back spindle 160 of the machine tool 100 will be described based on FIGS. 22A to 25B.
FIG. 22A is a flowchart showing the procedure for adjusting the size of the gap between the bar and the rotary guide bush, FIG. 22B is a flowchart showing the preparation process shown in FIG. 23A, and FIG. 22C is a flowchart showing the gap adjustment process shown in FIG. 23A. 23 is a schematic diagram showing a state in which the engagement between the rotating jig and the adjustment nut is released, and FIG. 24 is a schematic diagram showing the rotating jig and the bar shown in FIG. 23 as viewed from the rear. 25A is a schematic diagram showing a state in which the front main shaft is advanced to engage the rotating jig and the adjustment nut, and FIG. 25B is a diagram showing the state in which the rear main shaft is rotated to adjust the size of the gap between the bar and the guide bush body. It is a schematic diagram explaining a process.
Note that the sixth specific example includes a part of the same procedure as the first specific example, the third specific example, and the fifth specific example, so The steps similar to those in the fifth specific example are given the same step numbers as those in the first, third, and fifth specific examples, and a description thereof will be omitted.

<3.6.1. Preparation process＞
(Step S1000A)
First, the machine tool 100 performs a preparation process shown in FIG. 23B.

(Step S1400A)
After performing steps S110, S12, and S130, the grip of the bar W is switched from the back main spindle 160 to the front main spindle 120, and the front main spindle 120 is moved while the front main spindle 120 grips (holds) the bar W. The rotary jig 190 is moved forward and the engagement pin 192 of the rotary jig 190 is inserted into the engagement hole 145b1 of the adjustment nut 145 of the rotary guide bush 140.
By inserting the engagement pin 192 of the rotating jig 190 into the engagement hole 145b1 of the adjustment nut 145 of the rotary guide bush 140, the orientation of the adjustment nut 145, that is, the orientation of the guide bush main body 144, is determined in a predetermined direction. It will be done.

Note that when the front main shaft 120 moves forward, if the engagement hole 145b1 of the adjustment nut 145 and the engagement pin 192 of the rotation jig 190 are misaligned in the rotational direction, the engagement hole 145b1 of the adjustment nut 145 and the rotation jig 192 are misaligned. Rotate the bar W (i.e., the back main shaft 160 holding the bar W) or the adjustment nut 145 (i.e., the guide bush main body 144) until the engagement pin 192 of the tool 190 directly faces each other.

(Step S1500A)
Next, the front main shaft 120 is retreated from the rotary guide bush 140 until the rotating jig 190 is disengaged from the adjustment nut 145, resulting in the state shown in FIG. 23.

<3.6.2. Inspection process>
(Step S2100A)
After carrying out step S200, the grip of the bar W is switched from the front main shaft 120 to the back main shaft 160, and the back main shaft 160 is rotated by a predetermined angle in a predetermined direction.
That is, by rotating the back main shaft 160, as shown in FIG. 24, the bar W is rotated by a predetermined angle θ from the reference angular position P to the angular position P1.

Thereafter, the process proceeds to step S22, and if the rotation angle of the rotary guide bush drive motor 149 is within the predetermined angle range, it is assumed that the gap between the bar W and the guide bush main body 144 is the optimum gap size. , the adjustment of the size of the gap between the bar W and the guide bush main body 144 is completed.
In step S220, if the rotation angle of the rotary guide bush drive motor 149 is less than the lower limit of the predetermined angle range, and if the rotation angle of the rotary guide bush drive motor 149 exceeds the upper limit of the predetermined angle range, the first concrete As in the example, it is necessary to adjust the size of the gap between the bar material W and the guide bush main body 144, and the process proceeds to step S230, step S24, and step S25.

<3.6.3. Gap adjustment process>
(Step S3000A)
After carrying out step S25, the process proceeds to step S3000A, and various steps of a gap adjustment process for adjusting the size of the gap between the bar material W and the guide bush main body 144 shown in FIG. 22C are performed.

(Step S3100A)
First, the grip of the bar W is switched from the back main shaft 160 to the front main shaft 120, and the front main shaft 120 is advanced until the rotating jig 190 is inserted into the adjustment nut 145 of the rotary guide bush 140, and the state shown in FIG. 25A is obtained. do.

(Step S3200A)
Then, the grip of the bar W is switched from the front main shaft 120 to the back main shaft 160, and while the bar W is held by the back main shaft 160, as shown in FIG. 25B, the output result by the guide bush opening degree determination unit 181b is Based on this, the back main shaft 160 is rotated by a predetermined amount in a predetermined direction.
The rotation of the back main shaft 160 causes the bar W to rotate, and the rotating jig 190 fixed to the bar W to rotate by a predetermined amount in a predetermined direction, and as in the first example, the bar W and the guide The size of the gap with the bush main body 144 is adjusted.

(Step S3300A)
After the size of the gap between the bar W and the guide bush main body 144 changes by a predetermined amount, the grip of the bar W is switched from the back main shaft 160 to the front main shaft 120, the front main shaft 120 is moved back, and the rotating jig 190 is moved. is removed from the adjustment nut 145 of the rotary guide bush 140, and the process returns to step S20.

Thereafter, the steps described above are repeated as appropriate until the rotation angle of the rotary guide bush drive motor 149 falls within the predetermined angle range.

<4. Effects produced by the machine tool 100>
According to the machine tool 100 described above, the control device 180 controls the spindle (the front spindle 120 in the first specific example and the fifth specific example, and the back spindle in the third specific example and the sixth specific example). A guide bush that determines the gap adjustment amount based on the rotation angle of the rotary guide bush drive motor 149 when the main shaft is rotated while the main shaft 160 holds the bar W and the rotary guide bush drive motor 149 is not energized. By having the opening determination section 181b, the main shaft drive motor (the front main shaft drive motor 123 in the first and fifth specific examples, the front main shaft drive motor 123 in the third and sixth specific examples) For example, when rotating the rear main shaft drive motor 163), the variation in the rotation angle of the rotary guide bush drive motor 149, which is rotatable, is based only on the rotation of the bar W accompanying the rotation of the main shaft drive motor. Compared to the case where the size of the gap between the rotary guide bush and the bar is adjusted based on the load of the spindle drive motor when the spindle holding the material is rotated by the spindle drive motor, the S/N ratio is higher and the rotary guide In the case of a structure in which the opening degree of the bush 140 is adjusted by the adjustment nut 145 and the rotary guide bush 140 rotates synchronously with the main shaft, the gap between the rotary guide bush 140 and the bar W can be automatically adjusted with high precision. can.
Alternatively, the control device 180 may hold the bar W with the rotary guide bush 140 and drive the spindle drive motor (the front spindle drive motor 123 in the second specific example, the back spindle drive motor 163 in the fourth specific example). ) has a guide bush opening determination unit 181b that determines the gap adjustment amount based on the rotation angle of the main shaft drive motor when the guide bush main body 144 of the rotary guide bush 140 is rotated without being excited. Therefore, when rotating the rotary guide bush drive motor 149, the variation in the rotation angle of the rotatable main shaft drive motor is based only on the rotation of the bar W accompanying the rotation of one of the rotary guide bush drive motors 149. Therefore, the S/N ratio is higher than when the size of the gap between the rotary guide bush and the bar is adjusted based on the load on the spindle drive motor when the spindle holding the bar is rotated by the spindle drive motor. In the case of a structure in which the opening degree of the rotary guide bush 140 is adjusted by the adjustment nut 145 and the rotary guide bush 140 rotates synchronously with the main shaft, the gap between the rotary guide bush 140 and the bar W is automatically adjusted with high precision. can do.

Further, in the first specific example, third specific example, fifth specific example, and sixth specific example, the encoder 149a detects the rotation angle of the rotary guide bush drive motor 149, and detects the rotation angle of the rotary guide bush drive motor 149. 181b determines the gap adjustment amount based on the rotation angle of the rotary guide bush drive motor 149, thereby determining the gap adjustment amount using the rotation angle of the guide bush main body 144 whose moment of inertia is smaller than the moment of inertia of the main shaft. Therefore, the gap adjustment amount can be determined with higher accuracy than when the gap adjustment amount is determined based on the rotation angle of the spindle drive motor.

Furthermore, in the first specific example and the third specific example, the rotation of the bar W around the rotation axis and the movement in the direction of the rotation axis are performed by the same main shaft (in the first specific example, the front main shaft 120, In the third specific example, the rear main shaft 160) allows the gap between the rotary guide bush 140 and the bar W to be automatically adjusted with high accuracy with a minimum device configuration.

<Modified example>
Although a machine tool that is an embodiment of the present invention has been described above, the machine tool of the present invention is not limited to the machine tool of the embodiment described above.

For example, in the above-described embodiment, the front spindle drive motor 123 was mounted on the headstock 121, but the front spindle drive motor does not need to be provided on the headstock; for example, it may be mounted on a bed to operate the transmission mechanism. The front spindle main body may be rotationally driven through the main shaft.
The same applies to the rear main shaft drive motor and the rotary guide bush drive motor.

For example, in the embodiment described above, the machine tool 100 was equipped with the front main spindle 120 and the back main spindle 160, but the first specific example of the procedure for adjusting the size of the gap between the bar W and the guide bush main body 144 and When implementing the second embodiment, the machine tool does not have to have a back spindle.

100... Machine tool 110... Bed 120... Front spindle 121... Headstock 122... Front spindle main body 122a... Chuck 123... Front spindle drive motor 124... Encoder 130... ... Front spindle feed mechanism 131 ... Z1 rail 132 ... Z1 slider 133 ... Z1 motor 140 ... Rotary guide bush 141 ... Guide bush holder 141a ... Guide bush holder main body 141b ... Bearing retainer 142...Guide bush sleeve 142a...Taper 142b...Set screw 142c...Threaded through hole 142d...Key 143...Bearing 144...Guide bush body 144a...Male thread 144b ... Slot 144c ... Taper 144d ... Groove 145 ... Adjustment nut 145a ... Female thread 145b ... Rear surface 145b1 ... Engagement hole 146 ... Timing pulley 146a ... Keyway 146b... Belt positioning groove 147... Retaining nut 148... Flange 149... Rotary guide bush drive motor 149a... Encoder 149b... Timing pulley 150... Guide bush support stand 150a... - Rotary guide bush insertion hole 151 ... Turret moving mechanism 152 ... Tool rest 152a ... Cutting tool 160 ... Back main spindle 161 ... Headstock 162 ... Back main spindle body 162a ... Chuck 163 ... Rear spindle drive motor 164 ... Encoder 165 ... Holding jig 165a ... Main shaft mounting tool 165a1... Front 165b ... Material holder 165b1 ... Screw hole 165c ... Connection bolt 165d... Tightening bolt 165e... Adjustment bolt 170... Back main shaft feeding mechanism 171... X2 direction feeding structure 171a... X2 rail 171b... X2 slider 171c... X2 motor 172... - Z2 direction feeding structure 172a... Z2 rail 172b... Z2 slider 172c... Z2 motor 180... Control device 181... Control unit 181a... Motor control section 181b... Guide bush opening degree Determining section 181c...Data table 182...Input unit 190...Rotating jig 190a...Screw hole 190b...Front surface 191...Tightening bolt 192...Engaging pin

W... Bar material F... Floor surface L... Rotating axis φ... Inner diameter of bar material holder V... Timing belt D1... Distance from rotating jig to adjustment nut D2...・ Distance B from the bar to the holding jig ... Fixing bolt P ... Reference angle position

Claims (5)

A main shaft that rotatably holds the bar;
a main shaft drive motor that rotationally drives the main shaft;
a rotary guide bush that supports and allows rotation of the bar advanced from the main shaft around the rotation axis and movement in the direction of the rotation axis, and rotates in synchronization with the main shaft;
a rotary guide bush drive motor that drives the rotary guide bush;
an encoder that detects a rotation angle of the rotary guide bush drive motor or the main shaft drive motor;
A machine tool comprising: a control device that controls operations of the main shaft and the rotary guide bush;
The rotary guide bush has a guide bush holder fixed to a guide bush support base, and the rotary guide bush is rotatable relative to the guide bush holder and allows the rod to rotate around the rotation axis and move in the rotation axis direction. a supported guide bush main body, and an adjustment nut that rotates the guide bush main body to adjust the size of the gap when adjusting the gap between the bar and the guide bush main body, and is screwed into the guide bush main body. and has
Based on the rotation angle of the rotary guide bush drive motor when the control device rotates the main shaft in a state where the main shaft holds the bar and does not excite the rotary guide bush drive motor, or The adjustment amount of the gap is determined based on the rotation angle of the spindle drive motor when the guide bush main body of the rotary guide bush is rotated with the bar held by the rotary guide bush and the spindle drive motor not energized. A machine tool characterized by having a guide bush opening determining section that determines the opening degree of the guide bush. the encoder detects a rotation angle of the rotary guide bush drive motor;
The machine tool according to claim 1, wherein the guide bush opening determining unit determines the adjustment amount of the gap based on the rotation angle of the rotary guide bush drive motor. 3. The machine tool according to claim 1, wherein a rotating jig that engages with and rotates the adjusting nut of the rotary guide bush is attached to the bar. A main shaft that rotatably holds the bar;
a main shaft drive motor that rotationally drives the main shaft;
a rotary guide bush that supports and allows rotation of the bar advanced from the main shaft around the rotation axis and movement in the direction of the rotation axis, and rotates in synchronization with the main shaft;
a rotary guide bush drive motor that drives the rotary guide bush;
an encoder that detects the rotation angle of the rotary guide bush drive motor;
a control device that controls operations of the main shaft and the rotary guide bush;
The rotary guide bush has a guide bush holder fixed to a guide bush support base, and the rotary guide bush is rotatable relative to the guide bush holder and allows the rod to rotate around the rotation axis and move in the rotation axis direction. a supported guide bush main body, and an adjustment nut that rotates the guide bush main body to adjust the size of the gap when adjusting the gap between the bar and the guide bush main body, and is screwed into the guide bush main body. A method for controlling a machine tool, comprising:
holding the bar with the main shaft;
rotating the main shaft around a rotation axis;
measuring the rotation angle of the rotary guide bush drive motor in a non-excited state caused by rotating the main shaft with the encoder;
determining the amount of adjustment of the gap based on the rotation angle of the rotary guide bush drive motor measured by the encoder;
rotating the main shaft around a rotation axis to rotate the guide bush body relative to the adjustment nut so as to achieve the determined clearance adjustment amount;
Machine tool control methods, including: A main shaft that rotatably holds the bar;
a main shaft drive motor that rotationally drives the main shaft;
a rotary guide bush that supports and allows rotation of the bar advanced from the main shaft around the rotation axis and movement in the direction of the rotation axis, and rotates in synchronization with the main shaft;
a rotary guide bush drive motor that drives the rotary guide bush;
an encoder that detects the rotation angle of the main shaft drive motor;
a control device that controls operations of the main shaft and the rotary guide bush;
The rotary guide bush has a guide bush holder fixed to a guide bush support base, and the rotary guide bush is rotatable relative to the guide bush holder and allows the rod to rotate around the rotation axis and move in the rotation axis direction. a supported guide bush main body, and an adjustment nut that rotates the guide bush main body to adjust the size of the gap when adjusting the gap between the bar and the guide bush main body, and is screwed into the guide bush main body. A method for controlling a machine tool, comprising:
holding the bar with the main shaft;
rotating the guide bush main body around a rotation axis;
measuring the rotation angle of the spindle drive motor in a non-excited state caused by rotating the guide bush main body with the encoder;
determining the adjustment amount of the gap based on the rotation angle of the spindle drive motor measured by the encoder;
rotating the guide bush main body around a rotation axis to rotate the guide bush main body relative to the adjustment nut so as to achieve the determined clearance adjustment amount;
Machine tool control methods, including: