JPH0753335B2 - Machine Tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention enables a plurality of gang heads (hereinafter simply referred to as shaft heads) to be engaged and disengaged around a revolving structure supported by an indexing device by moving in the rotational axis direction. The present invention relates to a machine tool in which a shaft head that is supported and indexed at a predetermined position by an index device is mounted on the tip of a drive unit, and the drive unit is advanced in the rotational axis direction to machine a workpiece.

[Prior Art] In a machine tool of this type, the shaft head is replaced according to the cycle diagram shown in FIG. That is, first, the drive unit in the original processing position is retracted to a predetermined exchange position, and the shaft head clamped at the tip of the drive unit is engaged with and supported by the revolving structure. Then, after unclamping the shaft head, the revolving unit is rotated by the index device to move the unclamped shaft head and index a new shaft head in front of the drive unit. Next, after the shaft head is clamped to the tip of the drive unit, the drive unit is advanced to the original position for machining and further advanced according to the machining command to perform machining. Such control was performed by the sequence controller.

[Problems to be solved by the invention]

However, in the conventional technique, since each operation for shaft head replacement is performed in series in time, there is a problem that the time required for replacement becomes long and the productivity cannot be improved. The present invention is intended to solve such a problem.

[Means for solving problems]

For this purpose, the machine tool according to the present invention, as illustrated in FIGS. 1 to 5, has an index device 20 that rotatably supports the revolving structure 23 and indexes the revolving structure 23 at a predetermined angle. Each shaft head is provided at an angle of
A plurality of guide supports 24 for supporting the revolving structure 30 by the movement of the revolving structure in the rotation axis direction, and the index device 20.
A machine tool including a drive unit 15 that clamps the shaft head 30 indexed to the front position by a clamping device 40 at its front end to drive the coaxial head and advances in the rotation axis direction to machine a workpiece. In the machine, the drive unit
Based on the position detector 56 that detects the position of 15, and the detection result of this position detector, the drive unit 15 retracts from a predetermined processing original position and the shaft head 30 with respect to the guide support 24.
When the engagement length of the clamp device 40 reaches a safety engagement range of a predetermined value or more, unclamping of the clamp device 40 is started, and the clamp device 40 for the shaft head 30 indexed to the front position of the drive unit 15 is started. A control device 50 is provided for starting the forward movement of the drive unit before and after the start of the clamping, and for stopping the forward movement of the drive unit if the safe engagement range is disengaged before the completion of the clamping of the clamp device. It is a thing.

[Action]

When replacing the shaft head 30, first, the drive unit 15 starts retreating from the original processing position, the shaft head 30 clamped at the tip of the drive unit 15 engages with the guide support 24, and its engagement length is predetermined. If the safe engagement range that is more than the value is reached, the controller 50
Starts the unclamping of the clamp device 40, and performs the unclamping of the shaft head 30 in parallel with the backward movement of the drive unit 15.
After the unclamping is completed and the drive unit 15 is retracted to the predetermined replacement position, the revolving structure 23 is moved by the index device 20.
Rotate to move the shaft head 30 until then, and
To the front of the drive unit 15. Then, the clamp device 40 starts clamping, and before and after this, the control device 50 starts the advance of the drive unit 15, and in parallel with the advance of the drive unit 15, the new shaft head 30 is clamped. This clamp is completed before the shaft head 30 moves out of the safe engagement range, the drive unit 15 further advances, reaches the original processing position, and enters the processing standby state. If the shaft head 30 has not been clamped within the safe engagement range due to some abnormality, the control device 50 stops the forward movement of the drive unit 15 and attaches the shaft head 30 to the drive unit 15. It prevents the shaft head 30 from slipping off or coming off.

〔effect〕

As described above, according to the present invention, the clamping and unclamping of the shaft head with respect to the drive unit are performed in parallel with the backward movement and forward movement of the drive unit. As a result, the time required to replace the shaft head can be reduced, and the machining cycle time can be shortened accordingly, thus improving productivity. Even if the shaft head is not completely clamped within the safety engagement range due to some abnormality, there is no possibility that the mounting position of the shaft head shifts or the shaft head falls off.

〔Example〕

The present invention will be described below with reference to the embodiments shown in FIGS.

First, the mechanical structure of the machine tool of this embodiment will be described with reference to FIGS. 2 and 3. As shown in the drawing, an index device 20 is provided above the bed 10 by means of a gate-shaped strut 12, and a revolving structure is provided at the tip of a rotary shaft 22 supported by a main body 21 thereof.
23 is fixed. Bed under index device 20
A drive unit 15 is guided and supported by a base 11 fixed on the base 10 so as to be movable in a direction parallel to the axis of a rotary shaft 22, and a reciprocating feed is given by a servo motor 16.

As shown in FIG. 3, the revolving structure 23 has a square shape when viewed from the axial direction, and the guide supporting members 24 are provided on the four outer peripheral surfaces thereof.
Is fixed. Each guide support 24 is provided with a pair of grooves 24a parallel to the axis of the rotary shaft 22 inwardly while one side of the shaft head 30 equipped with at least one rotary tool is provided with a groove 24a.
An engaging member having a pair of protrusions 33a slidably engaged with a
33 is fixed, and the shaft head 30 slidably engages the protrusion 33a with the groove 24a in the axial direction of the rotary shaft 22 so that it can be engaged and disengaged.
Supported by 3. The revolving unit 23 is revolvingly driven by the indexing drive mechanism 25 via the rotary shaft 22, and a predetermined shaft head 30 used for the next machining is positioned in the exchange position CP shown in FIG. To find out. As shown in FIG. 2, a pair of engagement plates 31 and 32, which are opposed to each other and project radially outward and inward, are fixed to the rear surface of each shaft head 30,
The tips of the engagement plates 31, 32 are formed in an arc shape concentric with the rotary shaft 22. An input shaft 34 having a clutch at its tip is provided between the engagement plates 31 and 32.

As shown in FIGS. 2 and 3, the index device main body 21
A pair of side guides are provided on both sides of the front of the
35 and the upper guide body 36 are fixed, and guide grooves 37, which are concentric with the rotary shaft 22 and inward, are continuously formed in the respective guide bodies 35, 36. Each shaft head 30 has a guide groove at the tip of an engaging plate 31 on the inner side thereof, except when it is indexed in front of the drive unit 15.
It is rotatably engaged with 37 and is restrained from moving in the axial direction.

As shown in FIGS. 2 and 3, the drive unit 15 is provided with a clamp device 40 for mounting the shaft head 30 on the front surface thereof. The clamp device 40 is provided at the front of the drive unit 15 and has a forward / backward movement shaft 42 that reciprocates in the X direction parallel to the rotary shaft 22 by a hydraulic drive mechanism 41, and a guide locking body fixed to the tip of the forward / backward movement shaft 42. It is composed of 43. Guide grooves 43a and 43b are provided on the upper and lower edges of the guide locking body 43 concentrically with the rotary shaft 22, so that the drive unit 15 can be replaced at the replacement position CP (the front end surfaces 15a and 15b of the drive unit 15 as shown in FIG. 2). (Shown by the position) and the guide locking body 43 is advanced, the guide groove 43a at the upper edge is continuous with the guide groove 37, and the guide grooves 43a and 43b are indexed in front of the drive unit 15. Engagement plate 3 of shaft head 30
Engage rotatably with the tips of 1,32. In this way the engagement plate 3
When the guide locking body 43 is retracted via the advancing / retreating shaft 42 by the hydraulic drive mechanism 41 in a state where the 1, 32 are engaged with the guide grooves 43a, 43b, the rear surface of the shaft head 30 becomes the front end surfaces 15a, 15b. The shaft head 30 is pressed and clamped at the front end of the drive unit 15, and the guide head 43 is advanced to unclamp the shaft head 30. The drive shaft 17 provided coaxially with the advancing / retreating shaft 42 has a clutch at its tip engaged with a clutch of the input shaft 34 of the clamped shaft head 30 to rotate the shaft head 30.

As shown in FIG. 1, the control device 50 for controlling the operation of the machine tool comprises a microprocessor 51, a memory 52 and a data input device 53. The microprocessor 51 is provided in the drive unit 15 and detects its position. Servo unit that controls the absolute position detector 56 such as a linear encoder or magnescale and the servo motor 16 for moving the drive unit 15
57 are connected to each other via an interface, and an indexing drive mechanism of the index device 20 via a sequence controller 55, a high-power circuit 58, and a hydraulic control circuit 59.
25 and the hydraulic drive mechanism 41 of the clamp device 40 are connected. When replacing the shaft head 30, the controller 50 drives the drive unit 15 (the position of the shaft head 30 is OQ) at the processing original position OP (shown by the positions of the front end faces 15a and 15b of the drive unit 15) shown in FIG.
And the engagement length between the engagement member 33 of the shaft head 30 and the guide support 24 of the revolving structure 23 is a predetermined value (for example, about 1/4 of the total engagement length).
When the safety position SP (the position of the shaft head 30 is SQ) is exceeded, the sequence controller 55 is instructed to start the unclamping of the clamp device 40, and when the replacement position CP shown by the solid line is reached, the drive unit 15 is stopped and If the sequence controller 55 is commanded to index the revolving structure 30 and the index completion signal is received from the sequence controller 55, the drive unit 15
Is moved forward, and the drive unit 15 is stopped when the processing original position OP is reached. During this forward movement, the control device 50 receives a signal indicating the completion of clamping of the clamp device 40 from the sequence controller 55, and when the drive unit 15 does not receive this signal even if it exceeds the safe position SP, the drive unit 15 is brought to an emergency stop. The sequence controller 55 starts the unclamping of the clamp device 40 by the command from the control device 50, and when this unclamping is completed, the revolving structure 30 is indexed by the command from the control device 50, and after the indexing is completed. The clamp device 40 is started to clamp at the same time when the index completion signal is output to the control device 50. The control program for the controller 50 to perform such an operation is stored in the memory 52.
Remembered in. In addition, the memory 52 has a data input device.
Data such as the processing original position OP, the safety position SP, and the exchange position CP input from 53 are stored.

Next, the operation of this embodiment will be described with reference to the flow chart of the control program shown in FIG. 4 and the cycle diagram shown in FIG.

The microprocessor 51 starts executing the control program shown in FIG. 4 in response to the command signal for shaft head replacement. First step
In 100, the microprocessor 51 operates the servo motor 16 to start the retreat of the drive unit 15 in the processing original position OP, and the current position detected by the absolute position detector 56.
The value of RP is read every moment and stored in a predetermined register. In the following step 101, the microprocessor 51 compares the value of the current position RP with the value of the stable position SP, and if RP ≦ SP, proceeds to step 102 and commands the sequence controller 55 to start unclamping the shaft head 30. . As described above, as shown in the cycle diagram of FIG. 5, the drive unit 15 is retracted from the processing original position OP and the engagement length of the shaft head 30 with respect to the guide support 24 of the revolving structure 23 becomes equal to or more than the predetermined value. When the range is reached, the shaft head 30 is unclamped in parallel with the backward movement of the drive unit 15. This unclamping is completed before the drive unit retracts to the conversion position CP.

In the following step 103, the microprocessor 51 compares the value of the current position RP with the value of the exchange position CP, and if RP ≦ CP, the drive unit 15 is stopped in step 104, and the signal from the sequence controller 55 in the following step 105. After confirming that the unclamping of the shaft head 30 has been completed, the sequence controller 55 is instructed to operate the index device 20, move the used shaft head 30, and move the new shaft head 30 to be used next. Start indexing. As described above, shaft head indexing in the cycle diagram shown in FIG. 5 is performed.

If the new shaft head 30 is indexed in front of the drive unit 15 in step 107, the sequence controller 55 activates the clamping device 40 to start clamping the new shaft head 30, and at the same time sends a signal indicating completion of indexing to the microprocessor.
This signal is sent to the microprocessor 51, which causes the microprocessor 51 to activate the servomotor 16 in step 109 to start the forward movement of the drive unit 15. As described above, as shown in the cycle diagram of FIG. 5, the shaft head 30 is clamped in parallel with the forward movement of the drive unit 15, and the clamp is completed within the safe engagement range. In step 110, the microprocessor 51 compares the value of the current position RP with the value of the safe position SP, and if RP ≧ SP, the clamp of the shaft head 30 is completed by the signal from the sequence controller 55 in the next step 111. If the current position RP reaches the processing reference position OP in step 112, the process proceeds to step 113 and the drive unit 1
5 is stopped to stop the operation of the shaft head replacement according to the present embodiment. Thereafter, if a machining command is given, the microprocessor 51 further advances the drive unit 15 and drives the shaft head 30 via the drive shaft 17 to machine the workpiece W on the mount 13. If the shaft head 30 has not been clamped within the safe engagement range due to some abnormality, the control operation proceeds from step 111 to step 114 and the microprocessor proceeds.
51 emergency stops the drive unit 15.

As described above, according to this embodiment, the guide support 24 and the engaging member 33 engage with each other for a considerable length, and the shaft head 30 moves with respect to the drive unit 15, as is clear from the entire cycle diagram of FIG. Within the safety engagement range where there is no risk of falling off or falling off, the drive unit 15 is moved in parallel with the backward movement and forward movement of the drive unit 15.
Since the shaft head is clamped and unclamped, the time required to replace the shaft head 30 is reduced by the time when the parallel operation is performed, and the cycle time can be shortened and the productivity can be improved. If the shaft head 30 is not clamped within the safe engagement range due to some abnormality, the drive unit 15 will stop in an emergency.
There is no risk that the clamp position of the shaft head with respect to the shaft shifts or the shaft head 30 falls off.

In the present embodiment, the clamp device 40 and the drive unit 15 are started to be clamped at the same time, but the start timings of these operations may be slightly different.

[Brief description of drawings]

1 to 5 show one embodiment of a machine tool according to the present invention, FIG. 1 is an overall explanatory view, FIG. 2 is a partially cutaway side view showing a main mechanical structure, and FIG. Is a front view corresponding to FIG. 2, FIG. 4 is a flow chart of a control program, FIG. 5 is a cycle diagram showing the operation, and FIG. 6 is a cycle diagram of a conventional technique. Explanation of symbols 15 …… Drive unit, 20 …… Index device, 23 ……
Revolving body, 24 ... Guide support, 30 ... Shaft head, 40 ... Clamping device, 50 ... Control device, 56 ... Position detector (absolute position detector).

Claims (1)

[Claims] 1. An index device for rotatably supporting a revolving structure and indexing the revolving structure at a predetermined angle, and an index device provided at a predetermined angle on the outer periphery of the revolving structure, each having one shaft head, the rotation axis of the revolving structure. A plurality of guide supports that are detachably supported by movement in the direction, and the shaft head indexed to the front position by the index device is clamped at its front end by a clamp device to drive the coaxial head to rotate the rotation axis. In a machine tool including a drive unit that advances in a direction to machine a workpiece, a position detector that detects the position of the drive unit, and the drive unit performs a predetermined machining based on the detection result of the position detector. The unclamping of the clamping device is started when the engaging length of the shaft head with respect to the guide support is retracted from the original position to reach a safe engagement range of a predetermined value or more, and The same drive is started if the drive unit starts to move forward and backward before and after the start of clamping of the clamp device with respect to the shaft head indexed to the front position of the unit, and if it goes out of the safety engagement range before the completion of clamping of the clamp device. A machine tool having a control device for stopping the forward movement of the unit.