JP3134046B2 - Control method of transport device in production line and its device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method of a transfer device for transferring a work between a plurality of machine tools and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, a transfer device on a production line is provided with a transfer bar which is disposed so as to penetrate between work stations such as machine tools and is operated to transfer a large number of works at once by one drive source. The transport device used;
There are two types of transport devices, which are disposed between the stations and are individually transported by independent drive sources. The former transfer device facilitates work transfer, that is, drive control of the transfer bar, but cannot be used unless the pitch between machine tools is generally the same. Has the disadvantage of poor flexibility. Further, there is a disadvantage that only in-line type transfer, in which works of all the work stations are simultaneously transferred, can be performed in accordance with the cycle time of the work station having the longest cycle time.
(See Japanese Patent Application Laid-Open No. 60-161060) On the other hand, in the latter transfer device, the control of the individual drive sources is troublesome, but the unloading of the work and the transfer of the work to be processed next are independent of each machine tool. And can be used for independent transfer performed individually, and the efficiency of the transfer operation can be improved. In addition, it is suitable for rearrangement of machine tools and flexibility at the time of process composition. (See JP-A-7-148636)

[0003]

However, in a production line using the latter independent transfer device, the following problems occur. That is, since each transport device operates individually, the transport devices may interfere with each other.

[0004] In order to avoid the above-mentioned interference, a control method for sequentially transporting the works one by one by a transport device is considered. For example, there is a case where the transfer device of the work unloading side confirms that the transfer of the work between the stations is completed, and the transfer device in the preceding process starts the transfer operation of the work, and this operation is sequentially repeated. However, the control method has a problem in that the cycle time of the entire transfer operation is extended and the operation efficiency is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems existing in the prior art described above, and has as its object to provide an inline type transfer device provided between a plurality of processing stations. It is an object of the present invention to provide a method of controlling a transfer device in a production line and a device thereof, which can prevent interference between transfer devices without lengthening the cycle time when used for transfer.

[0006]

According to the first aspect of the present invention,
In order to achieve the above object, in the production line, the work holding members of each transport device are moved backward from the initial position almost simultaneously toward the work receiving of the machine tool in the previous process, and the work is received by each holding member. After the completion of the work receiving step, the work holding member of the transfer device on the unloading side is moved forward, and immediately after confirming the start of the movement, the work holding member of the transfer device in the preceding process is moved forward. A step of sequentially performing the checking and advancing operations to the transfer device on the loading side, and sequentially transferring the work of each holding member to the work receiving of the next machine tool, and a transferring device on the loading side after the completion of the above-described work transferring process. The reversing operation of the work holding member is performed. Immediately after confirming the start of the reversing operation, the reversing operation of the work holding member of the transfer device in the next process is performed. Sequentially go to, and a step of returning each holding member to the initial position.

According to the first aspect of the present invention, the work holding members of each of the transfer devices are moved backward from the initial position substantially simultaneously toward the work receiving of the machine tool in the preceding process, and the work is received by each holding member. After the completion of the work receiving step, the forward movement of the work holding member of the transfer device on the unloading side is performed, and immediately after the start of the forward movement is confirmed, the forward movement of the work holding member of the transfer device of the previous process is performed. Advance / Confirm /
The advancing operation is sequentially performed to the transfer device on the loading side, and the work of each holding member is sequentially transferred to the work receiver of the machine tool in the next process. For this reason, mutual interference at the time of the forward movement of the work holding member is avoided without increasing the cycle time.

Next, after the completion of the work transfer process, the backward movement of the work holding member of the transfer apparatus on the loading side is performed, and immediately after the start of the backward movement is confirmed, the backward movement of the work holding member of the transfer apparatus in the next step is performed. Is performed. The reverse / confirmation / reverse operations are sequentially performed on the transport device on the carry-out side, and each holding member is returned to the initial position. For this reason, mutual interference at the time of backward movement of the work holding member is avoided without increasing the cycle time.

According to the second aspect of the present invention, the first aspect is provided.
The start of the forward movement of the work holding member of the transfer device is confirmed by the presence or absence of the forward start signal of the transfer servo motor provided in each transfer device, and the start of the backward movement of the work holding member is checked by each transfer servo. This is performed according to the presence / absence of the reverse start signal of the motor.

According to the second aspect of the present invention, since the forward or backward start of the work holding member is confirmed by the forward or backward start signal of the transport servomotor, the confirmation can be performed reliably and promptly.

According to the third aspect of the present invention, the second aspect is provided.
In, when there is a forward start signal of each transport servo motor, a flag is set in the storage means of the control device of the production line, and the forward operation of the work of the transport device in the previous process is started by confirming this flag, Each flag is set in the storage means when there is a backward start signal of each transport servo motor, and the backward operation of the work of the transport device in the next process is started by confirming the flag.

According to the third aspect of the present invention, since the start of the forward or backward operation of the work holding member is confirmed by the start signal of the transport servomotor and the flag is set, the forward or backward operation of the work holding member is confirmed. Is performed reliably and quickly.

[0013] In the fourth aspect of the invention, the first aspect is provided.
In any one of (1) to (3), the reverse movement of the work holding member from the initial position is performed by moving up from the initial position by a predetermined distance, and then moving backward to a position below the work receiving position of the machine tool in the previous process, and thereafter moving upwardly from the work receiving position. A step of moving up to the work receiving position, the forward movement of the work holding member is advanced from the receiving position to above the work receiving position of the machine tool in the next step,
Thereafter, the work holding member is lowered to a work delivery position below the work reception, and the backward movement of the work holding member from the work delivery position is caused to move backward from the delivery position to above the initial position, and then to the height of the initial position. It consists of a step of being lowered.

According to the fourth aspect of the present invention, the work holding member is raised, moved backward, raised, moved forward, lowered, moved backward, from the initial position.
Since the work holding member is returned to the initial position by the downward cycle operation, the distance between the work holding member and the machine tool can be set large at the initial position. Therefore, it is possible to easily take measures to avoid the coolant and the cutting chips of the work holding member.

According to a fifth aspect of the present invention, a transfer device for transferring a work from a machine tool in a previous process to a machine tool in a next process is provided at an intermediate position between a plurality of machine tools arranged at a predetermined interval. In the arranged production line, the production line includes a main control device that integrally controls each of the transfer devices, and a plurality of sub-control devices that respectively control the transfer operation of each of the transfer devices. Means for confirming the start of the forward operation of the transfer device in the next process with respect to the transfer device, and the forward operation of the transfer device in the preceding process when the start of the forward operation of the transfer device in the next process is confirmed by the means for checking the start of the forward operation. Forward commanding means for sequentially instructing the transfer device, means for confirming the start of the backward movement of the transfer device in the preceding process for each transfer device, and When the operation start is confirmed, it includes a backward command means for sequentially commanding the reverse operation of the transport device of the next step.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for controlling a transfer device in a production line according to the present invention will be described below with reference to the drawings.

First, an outline of the production line will be described with reference to FIG. 1. For example, first to third machine tools 11 to 13 for performing various kinds of processing such as drilling a work W such as a cylinder block of an engine are provided with a predetermined number. They are arranged in series at intervals. On the workpiece loading side of the first machine tool 11, a loader 14 having a conveyor 15 for loading and waiting the workpiece W at a predetermined interval is disposed. An unloader 16 having a conveyor 17 for unloading the processed workpiece W to the next line at a predetermined interval is provided on the workpiece unloading side of the third machine tool 13. In this embodiment, the loader 1
4. The machine tools 11 to 13 and the unloader 16 are
These are referred to as fifth work stations S1 to S5.

The first to fifth stations S1 to S5
Between them, first to fourth transfer devices 21 to 24 for independently transferring the work W are provided, and the work W can be transferred from the work loading side station to the work unloading side station. is there.

The work mounting jigs 11a to 13a in the first to third machine tools 11 to 13 are configured in substantially the same manner. The configuration of the work mounting jigs 11a to 13a will be briefly described. A fixed table 26a or an index table 26b having substantially the same outer shape is supported on a machine base 25, and the index table 26b is moved in a horizontal plane by a horizontal rotation servomotor 27. It is indexed and rotated within. A support 28 is supported on the upper surfaces of the tables 26a and 26b.
A fixed table 2 having substantially the same outer shape is provided on the support base 28.
9a or the tilt table 29b is supported, and the tilt table 29b is supported by a vertical rotation servomotor 30 so as to be positionable in a vertical plane. The upper surface of the tilt table 29b has a work receiver 31a, and a gripper 31 for positioning and clamping the work W on the work receiver 31a is attached.

The posture of the work gripper 31 can be changed to a desired position by the index table 26b and the tilt table 29b in accordance with the processing at each station, and predetermined processing such as drilling holes on the work is performed. Will be When the processing on the work is completed, the gripper 31
Is returned to the original position and stopped.

The first to fourth transfer devices 21 to 24 have the same configuration. FIGS. 2 to 5 show the configuration of this transfer device.
The T-shaped lifting frame 42 is mounted on the upper portion of the base 41 so as to be vertically reciprocable along a lifting guide 41a. The lifting frame 42 has a nut member 42a, and is moved up and down by a lifting servomotor 43 and a ball screw 44 provided on the base 41 side.

A first table 45 is provided above the elevating frame 42 by a guide mechanism (not shown).
In FIGS. 3 and 4, the left direction is movably supported in the forward direction, and the right direction is referred to as the rear direction. A first rack 46 is formed below the first table 45, and a first pinion 47 supported by the lifting frame 42 is engaged with the rack 46. A transport servomotor 48 is fixed to the lifting frame 42, and a drive gear 49 is connected to an output shaft of the motor 48, and the gear 49 is meshed with the first pinion 47. Accordingly, when the drive gear 49 is rotated forward (arrow in FIG. 2) by the motor 48, the first pinion 47 is rotated, and the first pinion 47 and the first pinion 47 are rotated.
The first table 45 is moved rearward (to the right in FIG. 2) via the rack 46. In addition, the first to fourth transfer devices 21
When each of the servo motors 48 to 24 is referred to individually, 4
8A, 48B, 48C, and 48D.

Above the first table 45, a second table 50 is provided so as to be able to reciprocate by a guide mechanism (not shown) provided on the first table 45. A second rack 51 is provided below the second table 50, and a fixed rack 52 is attached to a predetermined position of the lifting frame 42. On the first table 45, a pinion 53 meshed with the fixed rack 52 is supported.
Similarly, a pinion 54 engaged with the second rack 51 is supported on the table 45. As shown in FIG. 4, the pinion 53 is
The pinion 53a is engaged with the pinion 54. Then, the first table 4 is rotated via the rotation of the servomotor 48 and the gear 49 and the pinion 47.
When 5 is moved rearward (to the right in FIG. 2), one pinion 53, 53a is rotated by the fixed rack 52, and this rotation is transmitted to the other pinion 54. For this reason,
The second rack 51 meshing with the pinion 54 is moved rearward, and the second table 50 is moved rearward at a speed twice the moving speed of the first table 45. On the upper surface of the second table 50, a holding member 55 for holding the work W is provided. When each of the work holding members 55 of the first to fourth transfer devices 21 to 24 is individually referred to, 55A, 55A
B, 55C and 55D.

The first table 45 and the second table 50 are moved in the forward direction by rotating the drive gear 49 in the reverse direction (in the direction opposite to the arrow in FIG. 2) by the servo motor 48. The reverse operation is performed.

The work holding members 55 of the above-described first to fourth transfer devices 21 to 24 are operated by the elevation servomotor 43 and the transfer servomotor 48 as shown in FIG. 5 to transfer the work. That is, the initial position P1 indicated by a solid line in FIG. 5 is, for example, an intermediate position between the third station S3 and the fourth station S4, and after rising from the initial position P1 to a predetermined height position, a predetermined distance, that is, It moves backward to the position below the work receiver 31a of the third station S3 in the process, further moves up a predetermined distance, receives the work W from the work receiver 31a of the station S3, and is moved above the work receiving position P2 above the work receiver 31a. . afterwards,
After the holding member 55 is advanced with the work W to a predetermined distance, that is, above the work receiver 31a of the fourth station S4 in the next step, the holding member 55 is further lowered by a predetermined distance to transfer the work W to the work receiver 31a of the station S4. It is lowered to the work delivery position P3 below the receiving 31a. Thereafter, the holding member 55 is moved backward to above the initial position P1, and then is lowered to the height of the initial position P1 and stopped. The forward movement of the holding member 55 is performed once in one cycle, but the ascending, retreating, and descending are each performed twice. Therefore, in FIGS. "2" is attached.

Next, with reference to FIG. 6, a description will be given of a control device of the transfer device in the production line described above. The main control device 60 controls the entire production line, and the main control device 60 also has a function of a first sub-control device 61 that independently controls the operations of the loader 14 and the first transfer device 21. . The operations of the machine tool 11 and the second transfer device 22 are independently controlled by the second sub-control device 62. Similarly, the operation of the machine tool 12 and the third transfer device 23 is independently controlled by the third sub-control device 63, and the operation of the machine tool 13 and the fourth transfer device 24 are independently controlled by the fourth sub-control device 64. 2nd
The fourth sub-control devices 62 to 64 are constituted by, for example, a sequencer, and can perform various operations of the corresponding machine tool and the transfer device based on a preset program. The second to fourth sub-control devices 62 to 64 are connected to a main control device 60, and the signals from the main control device 60 control the entire transport operation of the transport devices 21 to 24. The control function of the unloader 16 is
The main control device 60 shares the same functions as the first sub-control device.

The main control unit 60 includes a central processing unit (CPU) 65, a read-only memory (ROM) 66 in which an operation control program is stored in advance, and various types of data that are temporarily stored and readable by a random access memory (ROM). A memory (RAM) 67 is provided. The CPU 6
5 is the loader 1 via the input / output interface 68.
4, the first transport device 21, the second to fourth sub-control devices 62 to
64 and the unloader 16.

The CPU 65 is provided with means for confirming the start of forward operation for confirming the presence or absence of a forward rotation (work advance) start signal of the transport servo motors 48A to 48D of the first to fourth transport devices 21 to 24. The circuit 69 is connected to a discriminating circuit 70 which constitutes a means for confirming the start of a reverse operation for confirming the presence or absence of a reverse rotation (work reverse) start signal of the servo motors 48A to 48D. Further, the RAM 67 is provided with a forward flag register 71 and a reverse flag register 72 as storage means for setting a flag when the start of the forward operation or the start of the reverse operation of each transport device is confirmed.

The CPU 65 determines whether or not there is a flag in the forward (or reverse) flag register 71 (or 72), confirms the start of forward (or reverse) operation, and executes the preceding step (or next step). ) Is provided with a function as forward (or reverse) command means for sequentially instructing the forward (or reverse) operation of the transfer device.

Next, the control operation of the first to fourth transfer devices 21 to 24 in the production line configured as described above will be described. Now, when an operation signal is output to the first to fourth sub-control devices 61 to 64 based on a control program stored in advance in the ROM 66 of the main control device 60, the first to fourth sub-control devices 61 to 64 cause the first ~ 4th conveyance device 21-24
Are respectively started. Then, as shown in FIG. 7, the first to fourth transport devices 21 to 24
After the workpiece holding members 55A to 55D are simultaneously raised to a predetermined height from the initial position P1 shown in FIG. 5, each of the workpiece holding members 55A to 55D is moved backward and is respectively moved backward to a station position corresponding to a loader or a machine tool on the work loading side. The work W is raised to the predetermined height position and stopped at the receiving position P2, and the respective works W are received on the holding members 55A to 55D, respectively.

Thereafter, the first to fourth transfer devices 21 to 24
The forward movement of the workpiece holding members 55A to 55D is sequentially performed from the fourth transporting device 24 on the unloading side to the first transporting device 21 on the loading side as follows. That is, when the transport servomotor 48D of the fourth transporting device 24 on the unloading side is rotated forward and the forward movement of the work holding member 55D is started, the forward rotation start signal “present” is determined by the main controller 60. been confirmed by circuit 69, is vertical flag F ₁ indicating that the forward flag register 71 of RAM67 from CPU65 fourth workpiece holding member 55D has started forward. The presence or absence of the flag F ₁ is determined by the CPU 65 and the flag F ₁
When it is confirmed that there is a signal, a start signal is output from the main control device 60 to the transport servomotor 48C of the third transport device 23, and the work holding member 55C of the third transport device 23 is moved forward. Here, the forward rotation start signal is determined by the determination circuit 69 of the main controller 60, and the third signal is sent from the CPU 65 to the forward flag register 71 of the RAM 67.
> Chromatography click holding member 55C is flagged F ₂ indicating that it has started to move forward. Presence or absence of the flag F ₂ is CPU6
5 is determined from, if it is confirmed that the flag F _2, the main control from the apparatus 60 to the feeding servo motor 48B of the second transport device 22 is output start signal, the second transfer device 2
The second work holding member 55B is moved forward.

The above work holding members 55D, 55C, 5
Check 5B forward and the - forward movement and in the same manner, when the forward flag F ₃ of the second conveying device 22 workpiece holding member 55B is confirmed, forward motion of the workpiece holding member 55A of the first transfer device 21 is started You. And all the transfer devices 21 to
The forward movement of 24 works is performed to the station position of the next process. Further, the lifting / lowering servomotor 43 of each transport device is started to activate each of the work holding members 55D to 55D.
5A is moved down to transfer the work W to the work 31a and moved to the transfer position P3. In this way, the work W of each of the transfer devices 24 to 21 is
6. The workpieces are sequentially delivered to the workpiece receivers 31a of the machine tools 13, 12, 11.

The backward movement of the work holding members 55A to 55D of the first to fourth transfer devices 21 to 24 is sequentially performed from the first transfer device 21 on the loading side to the fourth transfer device 24 on the discharge side as follows. Will be This reverse operation is similar to the forward operation,
Work holding members 55A-5 of third transfer devices 21-23
When the reverse rotation start of 5C servomotor 48A~48C is confirmed by the determination circuit 70, the reverse flag F ₄ to F ₆ are built in the register 72. The flags are sequentially checked, and the backward movement of the work holding members 55B, 55C, and 55D is sequentially performed.

In the timing chart shown in FIG. 7, the work W is delivered to the work receiver 31a of the first to third machine tools 11 to 13 by the lowering of the work W by the first to third transfer devices 21 to 23. Then, the gripper 31 clamps after positioning (locating) the work W.
Next, for example, in the station S2, in order to provide the tilt table 29b, the station S2 is rotated at a predetermined inclination angle in a vertical plane by the servo motor 30, and processing such as drilling is performed. After processing is completed, the servo motor 30 is rotated in the reverse direction,
The work W is returned to the original posture. Thereafter, the gripper 31 releases the positioning and clamping of the work W. In the station S3, since the index table 26b is provided, the servo motor 27 is rotated by a predetermined angle in a horizontal plane to perform processing such as drilling. After processing is completed,
The servo motor 27 is rotated in the reverse direction, and the work W is returned to the original posture (tilt return). Thereafter, the gripper 31 releases (unlocates, unclamps) the positioning and clamping of the work W. In the station S4, processing such as drilling is performed immediately without changing the posture of the work W. After processing is completed, the gripper 31 releases the positioning and clamping of the work W. While the above operation is being performed for each station S2, S3, S4, the loader 1
The work is carried into the unloader 4, and the work of the unloader 16 is carried out. When the above operation is completed in all the stations, the next work transfer operation is performed as described above.

Next, the operation and effect of the transfer device in the production line of the embodiment will be described. (A) the forward movement of the workpiece W in the third transfer device 23 of the work loading side after confirming the flag F ₁ indicating the start of forward movement of the fourth transporting device 24 of the unloading side in the embodiment is performed, the Since the forward / confirmation / forward operations are sequentially performed to the transfer device on the work loading side, the following effects are obtained.

Without increasing the cycle time, the fourth
Work holding members 55D to 5 of first transfer devices 24 to 21
Interference at the time of the forward movement of the 5A can be prevented. (B) above embodiments backward operation of the workpiece W of the second transport device 22 of the work unloading side is performed after checking the flag F ₄ indicating the start of the reverse operation of the first transfer device 21 of the carry-in side, the The reverse, confirmation, and reverse operations are sequentially performed to the transfer device on the work unloading side, and the following effects are obtained.

Without increasing the cycle time, the first
Work holding members 55A to 55 of fourth transfer devices 21 to 24
It is possible to prevent interference during 5D reverse operation. (C) In the above embodiment, the first table 45 and the second table 50 are used to form a double-speed moving mechanism.
The stroke of the work holding member 55 can be longer than the width of the transfer device.

(D) In the above embodiment, the work holding member 5
5 is moved forward and backward by the transportable servomotor 48 which can be numerically controlled, so that the moving stroke of the holding member 55 in the front-back direction can be arbitrarily set.

(E) In the above embodiment, since the work holding member 55 is raised from the initial position and then moved backward and ascended, the machine tool 11 is moved in the state where the work holding member 55 is at the initial position P1. 13, the holding member 55 can be held at a position distant from 〜13, and measures for avoiding coolant and cutting chips can be easily taken. In addition, index tables 26b, 29b and tilt table 29b can be provided on the machine tool, and the machine tool can be easily changed.

Each of the machine tools 11 to 13 can be manually operated independently. When it is confirmed from the work presence / absence signal that there is no work in the machine tool on the work unloading side, the transfer device in the preceding process is manually transferred independently. The machine tool is operated after the transfer device after the machine tool operated alone is operated.

In the event of an abnormality, the work W of the machine tool in the next process is carried out and adjusted as in the case of the single operation. The present invention is not limited to the configuration of each of the embodiments described above. For example, the configuration of each unit can be arbitrarily changed and embodied as follows. (1) In the above embodiment, the fourth and second transfer devices 24 to 22
F ₁ to F for confirming the start of the forward movement of the workpiece W
₃ was to make a, work instead of this, a rotation detection signal of the rotation sensor of the conveying servomotor 48D～48B (not shown) are input to the main controller 60, a predetermined time after it detects the signal To move the workpiece holding member on the loading side forward. (2) In the above embodiment, the confirmation signals for the start of the forward operation and the start of the reverse operation of each work holding member 55 are obtained from the start signals of the transport servomotors 48A to 48D, respectively. A dog is provided on the member 55 side, for example, on each second table 50 supporting each work holding member 55, and a sensor such as a limit switch facing the dog is provided on each of the work mounting jigs 11a to 13a. By detecting the actual movement of 55,
To obtain a confirmation signal of the start of the forward operation and the start of the reverse operation. (3) The lifting 1 and the falling 2 of the work holding members 55A to 55D of the above embodiment are omitted. (4) An index table 26b and a tilt table 29b are provided on all work mounting jigs of each station. Alternatively, fixed tables 26a, 29 according to the processing
It should be configured by appropriately combining with a.

The technical ideas other than the claims that can be grasped from the above embodiment will be described below together with their effects.
6. The control device for a transfer device in a production line according to claim 5, wherein the work holding members 55 of the transfer devices 21 to 24 are supported by a second table 50 operated by a double speed mechanism in a front-rear direction.

In the case of this device, the lifting frame 42 of the transfer devices 21 to 24 can be reduced in size, and the installation space for the machine tool can be increased accordingly.

[0044]

As described above, according to the first or fifth aspect of the present invention, the cycle time is lengthened when the transfer devices disposed between a plurality of machine tools are used for in-line transfer. There is an excellent effect that the interference between the transfer devices can be prevented without the need.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the forward or backward start of the work holding member is confirmed by the forward or backward start signal of the transport servo motor. Confirmation can be performed reliably and quickly.

According to the third aspect of the invention, in addition to the effect of the second aspect of the present invention, the start of the forward or backward operation of the work holding member is confirmed by the start signal of the transport servomotor and the flag is set. Thus, it is possible to reliably and promptly confirm the start of the forward or backward operation of the work holding member.

According to a fourth aspect of the present invention, in addition to the effects of the first to third aspects, the work holding member is raised, moved backward, raised, advanced, lowered, moved backward from the initial position.
Since the work holding member is returned to the initial position by the downward cycle operation, the distance between the work holding member and the machine tool can be set large at the initial position, and measures for avoiding coolant and cutting chips of the work holding member can be easily performed. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an embodiment of the present invention.

FIG. 2 is a schematic front view of the transfer device.

FIG. 3 is a schematic front view of the transfer device.

FIG. 4 is a partial cross-sectional view of the transfer device.

FIG. 5 is a view for explaining the operation of a workpiece gripper.

FIG. 6 is a block diagram showing a control circuit of the transfer device.

FIG. 7 is a diagram illustrating a transport operation of the transport device.

[Explanation of symbols]

11 to 13: first to third machine tools, 11a to 13a: work mounting jigs, 21 to 24: first to fourth transfer devices, 31
... work gripper, 31a ... work receiver, 42 ... elevation frame, 43 ... elevation servomotor, 45 ... first table,
48A to 48D: transport servo motor, 50: second table, 55A to 55D: work holding member, 60: main control device, 61 to 64: first to fourth auxiliary control devices, 65: forward command means and reverse command CPU, 69 (7
0)... A discriminating circuit for the rotation start signals of the motors 48A to 48D constituting the means for confirming the start of the forward (reverse) operation, 71 (7
2) ... forward (backward) the forward as a storage means constituting the means of confirming the operation start (reverse) flag register, P1 ... initial position, P2 ... receiving position, P3 ... delivery position, F ₁ to F ₆
…flag.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-148636 (JP, A) JP-A-62-208852 (JP, A) JP-A-6-3054851 (JP, A) JP-A-59-1984 124615 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B23Q 7/14 B23Q 41/02

Claims (5)

(57) [Claims] 1. A production line in which a transfer device for transferring a work from a machine tool in a previous process to a machine tool in a next process is arranged between a plurality of machine tools arranged at a predetermined interval. The work holding member of the transfer device is moved backward at the same time from the initial position to the work receiving position of the machine tool in the previous process.
A step of receiving a work to each holding member, and after the completion of the work receiving step, the work holding member of the transfer device on the unloading side is moved forward, and immediately after confirming the start of the movement, the work holding member of the transfer device in the preceding process is checked. The forward, confirming, and forward operations are sequentially performed to the transfer device on the loading side, and the work of each holding member is sequentially transferred to the work receiving of the next machine tool. After the process is completed, the reversing operation of the work holding member of the transfer device on the loading side is performed, and immediately after confirming the start of the reversing operation, the reversing operation of the work holding member of the conveying device of the next process is performed. And sequentially returning the holding members to the initial position, thereby controlling the transfer device in the production line. 2. The method according to claim 1, wherein the start of the forward movement of the work holding member of the transfer device is confirmed by the presence or absence of a forward start signal of a transfer servomotor provided in each transfer device. A method for controlling a transfer device in a production line, wherein the start is confirmed by the presence or absence of a reverse start signal of each transfer servomotor. 3. The transfer device according to claim 2, wherein each flag is set in the storage means of the control device of the production line when the forward start signal of each transfer servomotor is present. The forward movement of the work is started,
Each flag is set in the storage means when there is a reverse start signal of each transfer servo motor, and the reverse operation of the work of the transfer device in the next process is started by confirming the flag. A method for controlling a transfer device in a line. 4. The reverse movement of the work holding member according to any one of claims 1 to 3, wherein the work holding member is moved backward from the initial position by a predetermined distance to a position below the work receiving position of the machine tool in the preceding process. , After which, the work holding member is advanced from the receiving position to a position above the work receiving position of the machine tool of the next process, and thereafter, is moved downward to the work receiving position above the work receiving position. The backward movement of the work holding member from the work transfer position includes a step of moving backward from the transfer position to above the initial position, and then lowering to the height of the initial position. A method of controlling a transport device in a production line, characterized by comprising: 5. A production line in which a transfer device for transferring a work from a machine tool in a previous process to a machine tool in a next process is arranged at an intermediate position between a plurality of machine tools arranged at a predetermined interval. A main control unit that controls each of the transfer units; and a plurality of sub-control units that control the transfer operation of each of the transfer units. The main control unit transfers the next process to each of the transfer units. Means for confirming the start of the forward operation of the apparatus; and forward command means for sequentially instructing the forward operation of the transport apparatus in the preceding step when the forward operation of the transport apparatus in the next process is confirmed by the means for confirming the start of the forward operation. Means for confirming the start of the backward operation of the transport device in the preceding process for each of the transport devices; and when the start of the backward operation of the transport device in the preceding process is confirmed by the means for confirming the start of the backward operation. And a reverse command means for sequentially commanding the reverse operation of the transfer device in the next step.