JP2004249341A - Workpiece transporting device for press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contribute to improve the operation rate of a press line by totally eliminating an origin setting or magnetic pole detecting operation when a power source is turned off. <P>SOLUTION: A rack 20 is provided on the fixed part 10 side of a linear motor 18; a pinion 21 engaging with this rack 20 is provided on the movable part 14 side of the linear motor 18; and an absolute type encoder 24 is mounted on the output shaft 23 of the pinion 21 to detect the position of the linear motor 18. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a work transfer device for a press machine that transfers a work using a linear motor as a drive source.
[0002]
[Prior art]
Conventionally, in a transfer press in which press working is performed at substantially the same time in a plurality of processing steps, work transfer for loading and unloading a work to be processed to and from a processing position in conjunction with continuous multi-step press working. Equipment is provided. In this case, the larger the size of the work to be processed, the longer the work transfer distance becomes. Therefore, in conjunction with the high-speed operation of the press, the work can be moved at high speed by using a linear motor as the drive source of the work transfer device. Attempts have been made to transport them.
[0003]
On the other hand, in a tandem press line in which a plurality of press machines are arranged in a line in the work transfer direction and press work is performed sequentially, there is a demand for a higher work transfer speed. Has proposed a work transfer device using a linear motor as a drive source (Japanese Patent Application No. 2001-400849). The work transfer device of the invention of the prior application provides a lift beam that can move up and down in parallel with the work transfer direction, and a carrier and a subcarrier that can move along the longitudinal direction of the lift beam. And a crossbar having a work holding means, and a linear motor is used as a moving means for moving the carrier.
[0004]
By the way, in a transfer system using this linear motor, an incremental type linear encoder is generally used to detect the position information of the linear motor.
[0005]
[Problems to be solved by the invention]
However, in general, an incremental encoder can detect the amount of movement of a movable body in a linear motor, in other words, position information by counting the number of pulses, but the position information is lost when the power is turned off. Therefore, it is necessary to use a limit switch or the like to find the origin of the movable body every time the power is turned off, which is extremely complicated and causes a decrease in the operation rate of the press line. is there.
[0006]
In addition, the magnetic pole detection of the linear motor also needs to be performed every time the control power supply to the servo amplifier is turned on, and there is also a problem that the operation is extremely complicated.
[0007]
The present invention has been made in order to solve such a problem, and there is no need to set an origin and detect a magnetic pole when a power supply is turned off, thereby eliminating the need for a press machine capable of contributing to an improvement in press line operation rate. It is an object to provide a work transfer device.
[0008]
[Means for Solving the Problems and Functions / Effects]
In order to achieve the above object, a work transfer device for a press machine according to the present invention includes:
A rack is provided on the fixed portion side of the linear motor, and a pinion that meshes with the rack is provided on the movable portion side of the linear motor, and an absolute encoder is mounted on the output shaft of the pinion to detect the position of the linear motor. It is characterized by performing.
[0009]
According to the present invention, the linear motion of the movable portion of the linear motor is converted into the rotational motion by the rack-pinion mechanism, and the rotational motion of the pinion is detected by the encoder to detect the position information of the movable portion. Therefore, it is possible to use a rotary absolute encoder instead of the conventional incremental encoder. Therefore, it is possible to effectively use the characteristic inherent in the absolute encoder, which is to output the absolute position data, and to set the origin of the movable body and the magnetic pole each time the power is turned off as in the conventional case. It is not necessary to perform the detection, and the operation rate of the press line can be improved.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a specific embodiment of a work transfer device for a press machine according to the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a partial front view of a tandem press line according to an embodiment of the present invention, and FIG. 2 is a side view of FIG. FIG. 3 is a sectional view taken along line AA of FIG.
[0012]
A plurality of tandem press lines 1 of the present embodiment are arranged in series from the upstream side (left side in FIG. 1) to the downstream side at a predetermined interval from each other (only two are shown in FIG. 1). Work transfer device (hereinafter, referred to as "feeder") 4 for transferring (unloading / loading) a work (not shown) between the processing stations of the presses 2 and 3 arranged adjacent to each other. It is configured with.
[0013]
Each of the presses 2 and 3 includes an upright 5 serving as a main body frame, an upper frame 6 disposed above the upright 5 and having a built-in driving force transmission mechanism, and supported by the upright 5 so as to be vertically movable. A slide 7 that is moved up and down via a driving force transmission mechanism; and a bolster 9 that is disposed opposite to the slide 7 and that is provided on a bed 8. The workpiece is machined by a lower mold mounted on the upper end of the workpiece.
[0014]
The feeder 4 is provided with a pair of lift beams 10 which are arranged on both left and right sides in the work transfer direction so as to be separated from each other. A rod 11 extending upward along the upright 5 is attached to an upper portion of the lift beam 10. A rack is engraved on the rod 11, and the rack meshes with a pinion which is drivingly connected to an output shaft of a lift shaft servomotor 12 via a power transmission mechanism. 10 is moved up and down.
[0015]
Below each of the left and right lift beams 10, a carrier 14 movable along the longitudinal direction (work transfer direction) of the lift beam 10 is arranged. Below the carrier 14, the work transfer direction along the carrier 14 is provided. , A movable subcarrier 15 is arranged. A pair of sub-carriers 15 facing each other are connected by a crossbar 16, and a plurality of vacuum cups 17 are mounted on the lower surface of the crossbar 16, and the vacuum cup 17 sucks a work. It has become.
[0016]
As shown in FIG. 3, a linear motor 18 is disposed between the lower surface of each of the left and right lift beams 10 and the upper surface of the carrier 14 facing the lift beam 10 as moving means for moving the carrier 14 along the lift beam 10. In addition, on both sides of the linear motor 18, linear guides 19 for guiding the movement of the carrier 14 with respect to the lift beam 10 are arranged. Here, the linear motor 18 includes a magnet 18a disposed on the lower surface of the lift beam 10 along the transport direction (longitudinal direction), and an upper surface of the carrier 14 facing the magnet 18a along the transport direction (longitudinal direction). The armature (carrier 14) having the coil 18b is linearly moved by a change in the magnetic field generated on the stator (lift beam 10) having the magnet 18a. I have.
[0017]
Although not shown in detail in the figure, a linear moving means for moving the subcarrier 15 along the carrier 14 is also provided between the lower surface of the carrier 14 and the upper surface of the subcarrier 15 opposed thereto. A motor is provided.
[0018]
In the feeder 4 configured as described above, the lift beam 10 is moved up and down by driving the lift axis servomotor 12, so that the vacuum cup 17 is moved up and down via the carrier 14, the subcarrier 15 and the crossbar 16. be able to. Further, by driving the linear motor 18 to move the carrier 14 along the longitudinal direction of the lift beam 10, and by driving a subcarrier moving linear motor (not shown), the subcarrier 15 is offset in the moving direction of the carrier 14. The cross bar 16 and the vacuum cup 17 can be moved in the work transfer direction. In this way, by controlling the position of two orthogonal drive shafts in the vertical direction and / or the transport direction, it is possible to control the movement trajectory of the vacuum cup 17, in other words, the workpiece transport trajectory.
[0019]
A rack 20 is attached to the side surface of the lift beam 10 (fixed portion side of the linear motor 18) along the longitudinal direction of the lift beam 10, and a pinion 21 is engaged with the rack 20. The pinion 21 is fixed to one end of an output shaft 23 rotatably supported by an L-shaped stay 22 attached to an end of the carrier 14 (the movable portion side of the linear motor 18). At the other end, an absolute encoder 24 is mounted. Thus, when the carrier 14 travels along the longitudinal direction of the lift beam 10, the pinion 21 meshing with the rack 20 rotates, and the current position (absolute position) of the rotation shaft (output shaft 23) is detected by the absolute encoder 24. can do. Therefore, the position information of the linear motor 18, in other words, the position information of the carrier 14 can be detected.
[0020]
In the above description, the case where the position information of the carrier 14 is detected by the absolute encoder 24 when the carrier 14 is moved by the linear motor 18 has been described. The position information may be detected by an encoder.
[0021]
Conventionally, since there is no absolute type linear encoder, it has been difficult to detect the absolute position information of the linear motor in a system using this type of linear motor. The linear motion of the carrier 14 (or the subcarrier 15), which is a movable part of the above, is converted into a rotary motion by a rack-pinion mechanism, and the rotary motion of this pinion is detected by an absolute type rotary encoder. An extremely simple configuration has an excellent effect that the absolute position information of the movable part linearly moved by the linear motor can be reliably detected. Therefore, the setting of the origin of the movable body and the detection of the magnetic pole need only be performed when the system is started or when the motor is replaced, and there is an advantage that it is not necessary to perform it every time the power is turned off as in the related art.
[0022]
In the present embodiment, an example in which the present invention is applied to a feeder of a tandem press line has been described. Needless to say.
[Brief description of the drawings]
FIG. 1 is a partial front view of a tandem press line according to an embodiment of the present invention.
FIG. 2 is a side view of FIG. 1;
FIG. 3 is a sectional view taken along line AA of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tandem press line 2, 3 Press 4 Feeder 10 Lift beam 14 Carrier 15 Subcarrier 18 Linear motor 20 Rack 21 Pinion 22 Stay 23 Output shaft 24 Absolute encoder

Claims (1)

A work transfer device for a press machine that transfers a work using a linear motor as a drive source,
A rack is provided on the fixed portion side of the linear motor, and a pinion that meshes with the rack is provided on the movable portion side of the linear motor, and an absolute encoder is mounted on the output shaft of the pinion to detect the position of the linear motor. A work transfer device for a press machine, characterized in that the transfer is performed.

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