JPH0832379B2 - Load control device for work support servo cylinder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a workpiece supporting servo for supporting a workpiece at a predetermined pressure position in a machine for applying pressure processing to a workpiece, which is used in a production facility for making a forged product, a test facility or the like. The present invention relates to a load control device for a cylinder.

[0002]

2. Description of the Related Art As shown in FIG. 2, a multi-axis machining apparatus, which is a machine for performing pressure machining, uses a hydraulic control type servo cylinder 20, 20 'whose load is controlled by a load control device so that an arbitrary same load is applied. The work 21 is held at a predetermined position on a working table (not shown) by applying force, and then the work 21 is vertically deformed by the force of the vertical cylinder 22.

Conventionally, as shown in FIG. 2, the servo cylinder 20 is used as a load control device 23 for controlling the load on both servo cylinders 20 and 20 'in order to hold the workpiece 21 under the same load. A servo amplifier 24 for operating the
A signal processor 25 for processing to send a load command signal to the servo amplifier 24, a load detector 26 and a displacement detector 27 attached to the servo cylinder 20, and a signal processor for the value detected by the load detector 26. A control unit 29 including a load amplifier 28 for sending to 25 is provided in each of the servo cylinders 20 and 20 '. Alternatively, as shown in FIG. 3, it is generally known that one servo amplifier 24 in one control unit 29 controls two servo cylinders 20 and 20 '.

[0004]

However, the problem with the conventional load control device described above is that the cylinder 20,
The holding position of the work 21 held by the force of 20 'fluctuates with time, and the vertical cylinder 22 may not be able to apply the force from directly above the work 21. The position variation of the work 21 is caused by holding the cylinders 20 and 20 'under load control, but this load control method is usually performed by the following method.

That is, the cylinder 20 uses the load detector 26,
In addition, the cylinder 20 'uses the load detector 26 to perform independent closed-loop control to individually apply load to the work 21 (see FIG. 2), and the cylinder 20 uses the load detector 26 to perform closed-loop control. The cylinder 20 'performs load control by inputting a signal from a servo amplifier 24 for driving the cylinder 20 in parallel, and load control is performed by one-sided dependent control (see FIG. 3) that applies a load to the work 21.

In the load control by these methods, the so-called
Since there is no position compensation function, position variation may occur for the following reasons. That is, the output error of the load detector 26 and the input / output error of other controllers. Or servo cylinder 20
Manufacturing error (including servo valve). Furthermore, it is the flow rate error of hydraulic oil (pipe resistance, viscosity change).

[0007] Then, when the position fluctuation occurs, after the load is applied to the work 21, a stopper is provided to prevent the cylinder 20 from moving beyond a certain range, or a signal value for controlling one cylinder 20 is controlled. There is a method such as doing. However, in the former case, the stopper must be changed each time depending on the shape of the work 21. And in the latter,
It is necessary to adjust each time according to an unspecified position change.

The present invention was devised in view of the above-mentioned circumstances, and an object thereof is to easily and reliably perform accurate holding of a work at a pressurizing position when pressurizing the work. (EN) Provided is a load control device for a work supporting servo cylinder.

[0009]

A load control device for controlling a pressing load applied to both servo cylinders for supporting a work according to the present invention is provided with both control units respectively provided in both servo cylinders and the servo cylinders. A load detector and a displacement detector which are provided. The one control unit includes a servo amplifier that operates the servo cylinder, a signal processor that processes to send an operation command signal to the servo amplifier, and a weight amplifier that sends a detection value of the load detector to the signal processor. The other control unit is composed of a servo amplifier and a signal processor similar to the one control unit, and a displacement amplifier for sending the detection value of the displacement detector to the signal processor. Further, a load command signal is sent as an operation command signal to the signal processor in the one control section, and an operation command signal is sent to the signal processor in the other control section, which is detected by the displacement detector in one control section. It is configured to send a displacement command signal that is a value.

One of the servo cylinders is controlled by one of the control units on the basis of the load command signal and its own load value, and the other servo cylinder is controlled by a displacement command signal which is a displacement detection value of one of the servo cylinders. To be able to control based on its own displacement value.

From this, by simply sending a load command signal to one servo cylinder, the load values of both servo cylinders are always commanded by the load information of one servo cylinder and the displacement information of one and the other servo cylinder. Therefore, it is possible to easily and surely hold the work accurately by the both servo cylinders at a predetermined position (pressurization position).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A load control device for a work supporting servo cylinder according to the present invention will be described below with reference to the illustrated embodiments.

The work 2 is attached to both servo cylinders 3 and 3 arranged so as to be able to press and support the opposite parts of the work 2.
The load control device 1 (see FIG. 1) that controls the pressing load applied to support the servo cylinder 3 at a predetermined position is provided on both servo cylinders 3 and 3 and on both control parts 9 and 9 '. It is provided with a load detector 6 and a displacement detector 7 attached thereto.

Here, one control unit 9 includes a servo amplifier 4 for operating the servo cylinder 3 and the servo amplifier 4
A signal processor 5 for processing to send an operation command signal to the signal processor 5, and a load amplifier 8 for sending the detected value by the load detector 6 to the signal processor 5. The other control unit 9'includes the same servo amplifier 4 and signal processor 5 as the one control unit 9.
And a displacement amplifier 10 for sending the value detected by the displacement detector 7 to the signal processor 5.

A load command signal is sent as an operation command signal to the signal processor 5 in one control unit 9 and an operation command signal is sent to the signal processor 5 in the other control unit 9'as one control unit 9 '. It is configured to send a displacement command signal which is a value detected by the displacement detector 7 in.

With this configuration, the load control of both servo cylinders 3, 3 for eliminating the position fluctuation of the work 2 is
Do the following: That is, the servo cylinder 3 controlled by the one control unit 9 performs the closed loop control using the load detector 6. Further, the servo cylinder 3 controlled by the other control unit 9 ′ inputs the output of the displacement detector 7 attached to the servo cylinder 3 controlled by the one control unit 9 as a displacement command signal, and By performing the closed loop control (displacement control) using the displacement detector 7, the load control device 1 as a whole performs the load control, and the load is applied to the work 2.

The control operation of the work supporting servo cylinders 3, 3 using the load control device 1 having such a structure is performed as described below (see FIG. 1).

First, the servo cylinder 3 controlled by the one control unit 9 is actuated by the input of the load command signal to the servo amplifier 4 to apply a load to the work 2. That is, the servo cylinder 3 controlled by one control unit 9 advances.

Next, at the same time as the operation of the servo cylinder 3 controlled by one control unit 9, the servo cylinder 3 controlled by the other control unit 9 ′ is operated by the servo amplifier 4 of the displacement command signal of the displacement detector 7. Is actuated by the input to and moves forward toward the work 2 to apply a load.

Next, if an excessive load is applied to the work 2 by the operation of the servo cylinder 3 controlled by the other control unit 9 ', the servo cylinder 3 controlled by the one control unit 9'
However, an operation is performed to move back by the error as much as the command value. At the same time, the servo cylinder 3 controlled by the other control unit 9'is also retracted.

Next, when the load on the work 2 is reduced by the operation of both servo cylinders 3 and 3 as described above, both servo cylinders 3 and 3 again move forward by an error.

By repeating the operations of both servo cylinders 3 and 3, the load of the command value on the work 2 for holding the work 2 at a predetermined position (pressurizing position by the vertical cylinder 11) is held. It will be.

[0023]

In order to grasp and fix the workpiece with a constant load, it is possible to grasp the workpiece with a constant load by simply controlling the respective loads of the two facing servo cylinders, but the position is compensated. Since it has no function, the work piece gradually changes and cannot be fixed at a predetermined position. For this reason, it was not possible to perform machining that causes vertical deformation of the work by the servo cylinder located directly above the work.

By controlling the load of both servo cylinders by the load control device of the present invention, it is possible to apply an arbitrary same load without position fluctuation to the work, and the work can be performed from directly above the work by a vertical cylinder or the like. You can surely apply force.

Moreover, as shown in FIG. 1, an input signal from the outside should be given to the signal processing unit of the servo cylinder controlled by the other control unit at the same time as the displacement command signal of the displacement detector of the one control unit. You can

Therefore, it is possible to move the workpiece to any position while applying the load by the above load control. In addition, it is possible to correct the position of the work before and after applying the force on the vertical cylinder, if necessary.

[Brief description of drawings]

FIG. 1 is a schematic view showing a load control device for a work supporting servo cylinder of the present invention.

FIG. 2 is a schematic view showing a conventional load control device.

FIG. 3 is a schematic view showing another aspect of the conventional load control device.

[Explanation of symbols]

1 ... Load control device, 2 ... Work, 3,3 '... Servo cylinder, 4 ... Servo amplifier, 5 ... Signal processor, 6 ... Load detector, 7 ... Displacement detector, 8 ... Load amplifier, 9,9' ... control unit,
10 ... Displacement amplifier, 11 ... Vertical cylinder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Kanesawa 3-4-5 Toyosu, Koto-ku, Tokyo Tomoe-Gumi Giken Co., Ltd. (56) Reference JP 62-9799 (JP, A) Special features Kaihei 3-303 (JP, A)

Claims (1)

[Claims] 1. A load control device for controlling a pressing load applied to support the work at a predetermined position on both servo cylinders arranged so as to press and support opposite parts of the work. Each of the control units is provided in each cylinder, and a load detector and a displacement detector attached to the servo cylinder. The one control unit includes a servo amplifier for operating the servo cylinder and the servo amplifier. To a signal processor for sending an operation command signal to the signal processor, and a load amplifier for sending a value detected by the load detector to the signal processor, and the other control unit is the same servo amplifier as one control unit and A signal processor and a displacement amplifier that sends a detection value from the displacement detector to the signal processor, and an operation command is sent to the signal processor in the one control unit. As a signal, a load command signal is sent, and a displacement command signal which is a detection value by a displacement detector in one control unit is sent to the signal processor in the other control unit as an operation command signal. Load control device for supporting servo cylinders.