JPS60261699A - Method for controlling inclination of movable frame in press - Google Patents

Abstract

PURPOSE:To control the inclination of a movable frame of an extrusion press operated by plural hydraulic cylinders within a permissible range and to improve the shape accuracy of a pressed product by detecting the inclination of the movable frame and adjusting the pressure oil flow to the specific hydraulic cylinder. CONSTITUTION:The pull back type extrusion press is constituted of the movable frame 1 moved on a pair of guides 2 by rams 4C-7C fixed to the pistons 5B of the hydraulic cylinders 4-7 to be actuated by hydraulic pumps 10-13 and a cylinder frame 3. The inclination of the movable frame 1 is detected by detectors 20-23 when the movable frame tilts during the press operation with such press. The shape of the pressed product is defective when the detected values exceed the permissible value and therefore the pressure oil flow to the specific pump among the pumps 10-13 is adjusted by a programmable controller PC38 to control the inclination of the frame 1 within the permissible range, by which the decrease in the shape accuracy of the pressed product is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling the inclination of a movable frame in a press such as an extrusion press.

(Prior Art and Problems Therewith) For example, in some extrusion presses, a movable frame is moved by a plurality of hydraulic cylinders supplied with pressure oil from a plurality of hydraulic pumps.

By the way, in the above-mentioned extrusion press, due to the difference in the discharge amount of the hydraulic pump and the difference in the operating resistance of the hydraulic cylinder, the movable frame (rolling) occurs, but in the past, the control device We have adopted a method of correcting the inclination of the movable frame. Therefore, in the past, the movable frame may extend significantly, and in that case, the movable frame may no longer move smoothly or the press may experience vibrations. In some cases, a high-precision product could not be obtained due to the occurrence of problems or the application of unreasonable force.

(Means for Solving the Problems) An object of the present invention is to provide a method for controlling the inclination of a movable frame in a press, which allows the first stroke of the movable frame to be within an allowable value and allows a product with high precision to be obtained. shall be.

In order to achieve this objective, the features of the present invention are as follows:
The inclination of the movable frame is detected by the detection means, and the control means increases or decreases the operating speed of the hydraulic cylinder by adjusting the amount of pressure oil supplied to the hydraulic cylinder when the inclination detected by the detection means is greater than or equal to the allowable value. This allows the inclination of the movable frame to be within the permissible value.

(Example) Hereinafter, a first example in which the present invention is applied to a 4-cylinder, 4-pump type pull-hack type extrusion press will be explained based on the drawings of Figs. 1 and 2. Fig. 1 shows the extrusion press. In Fig. 1, reference numeral 1 denotes an upright movable frame whose lower ends on both the left and right sides are provided with a pair of left and right guides 2 disposed in the front-rear direction so as to be slidable in the front-rear direction. There is.

Reference numeral 3 denotes a cylinder frame, which is erected on the rear side of the movable frame 1, with both frames 1.3 facing each other, and an extrusion mechanism (not shown) having a container etc. is disposed between both frames 1.3. has been done.

4 to 7 are four double-acting hydraulic cylinders, and movable frame 1
are moved in the front and back direction to operate the extrusion mechanism, and are arranged as a pair of upper and lower sides in the front and back direction on both the left and right sides between both frames 1.3, and are arranged in a square shape when viewed from the front. Each of the hydraulic cylinders 4 to 7 has tubes 4A, 5A, 6^ fixedly installed on the cylinder frame 3.
, 7^, piston 5B, rams 4C, 5C, 6C17
C, and rams 4C, 5C, and 6C.

The tip of 7C is fixed to the movable frame 1 with a nut 8.

10 to 13 are variable displacement hydraulic pumps, each pump 10 to 13 is a variable displacement hydraulic pump.
13 independently supplies pressure oil to each of the hydraulic cylinders 4 to 7 to operate each of the hydraulic cylinders 4 to 7.

The discharge amount of each pump 10-13 is controlled by an electro-hydraulic servo amplifier 15-18.

Detectors 20 to 23 detect the respective rams 4C and 5C from the amount of movement of each corner of the upper and lower ends of the left and right sides of the movable frame 1.

It detects the movement amount of 6C and 7C, and the movable frame 1
Rank 2OA, 21A, 228, 23A extending rearward from each corner of the upper and lower ends of the left and right sides of
, 2LA.

Binions 20B, 21B interlock with 22A, 23A,
22B, 23B and pinions 20B, 21B, 22B,
Pulse encoder 20C, 2IC, 2 interlocked with 23B
It is equipped with 2C, 23C, etc.

FIG. 2 is a block diagram showing the inclination control means of the movable frame 1.
Digital type speed setting device 25 for setting the discharge amount of rams 4C, 5C, and 6C.

Deviation of stroke amount (travel amount) of 7C (movable frame 1
A digital type deviation tolerance value setter 26 for setting the tolerance value of the slope (inclination of
Calculation of travel amount of 5C, 6C, 7C, electro-hydraulic servo amplifier 1
From input/output cards 31 to 36, etc., which exchange signals between the computer section and the outside for calculation of control variables 5 to 18, calculation of signals to the speed indicator 28, and sequence control processing of the press. The programmable controller 38 consists of a position indicator 27 and a speed indicator 28 that digitally display the position and speed of the movable frame 1.

Hereinafter, programmable controller (hereinafter referred to as PC)
The contents processed in step 38 will be explained. Note that the input/output cards 31 to 36 of the PC 3B are printed circuit boards for matching the level of external signals taken into the PC 3B or signals with external equipment outputted from the PC 38 to the outside.

First, in the PC 3B, the press sequence control unit 40 processes signals inputted from various detection switches 41 and various operation switches 42 via the sequence input card 33, and outputs the signals to the press solenoid valves and the like via the sequence output card 36. Output to external equipment 43 such as relays and lamps.

Next, the method of controlling the inclination of the movable frame 1 will be explained.
In addition to setting the allowable value of the deviation of the stroke amount of 6C07C, the reference speed of the movable frame 1 is set using the speed setting device 25. These set values are read by the data input card 31 of the PC 38, and the reference speed read by the data input card 31 is processed by the PC 3B and input to the electro-hydraulic servo amplifiers 15 to 18 via the analog output card 34. , the discharge amount of the hydraulic pumps 10 to 13 is determined, the operating speed of the rams 4C95C, 6C, and 7C of the hydraulic cylinders 4 to 7 is determined, and the set speed of the movable frame 1 is obtained.

Here, due to the difference in the discharge amount of each hydraulic pump lO to 13 and the difference in the operating resistance of each hydraulic cylinder 4 to 7, the movement amount of the ram 4C of the hydraulic cylinder 4 serving as a reference and the other /11] pressure cylinder 5 are determined. .6.7 If there is a difference in the amount of movement of the rams 5C, 6C, and VC, the movable frame 1 will tilt.

The processing in this case will be explained below.

That is, the amount of movement of each ram 4G, 5C, 6C, 7C is determined by the pulse encoder 20C, 21C, 21C of each detector 20-23.
22C, 23C pulse integration]・As the amount, P
It is read into the PC 38 via the counter input card 32 of C38.
, IC movement start signal is received.

When the movement of each ram 4C, 5C, 6C, and 7C starts, and there is a difference between the movement amount of the reference ram 4C and the movement amount of the other rams 5C, 6C, and 7C, addition and subtraction are performed inside the PC 38.

That is, inside the PC 38, between the cumulative count NC of the pulses of the pulse encoder 20C serving as a reference and the cumulative counts of pulses of the other pulse encoders 2IC, 22C, 23C, B, F, (C+D), (C±E),
(C±F) to calculate the deviation, the deviation value G,
■1, get ■.

Next, the deviation values G, H, and I are determined by the deviation tolerance value setter 26.
A comparison calculation is made with the deviation tolerance value A set in . That is,
Addition and subtraction are performed on (A±G), (A±H), and (A±I), and as a result, J and L are obtained.

Then, between this J, , L and the reference speed B set by the speed setting device 25, (B±J), (B0K), (
A comparison operation of B±L) is performed, and as a result, M, N, and P are obtained.

Then, until M and NP become zero, the electro-hydraulic servo amplifier 1
A signal is output on 6.17.18, and each hydraulic pump 11.
The discharge amount of 12.13 is controlled and the reference ram 4C
The operating speeds of the rams 5C, 6C, and 7C are increased or decreased, and the inclination of the movable frame 1 is corrected so that the amount of movement of the ram matches the amount of movement of the other rams 5G, 6C, and 7C.

Then, when the above values M, N, and P become zero, the output signal to each electro-hydraulic servo amplifier 16, 17, and 18 becomes the reference speed B, and the movement amount of the ram 4C as a reference and the other rams 5C,
The moving amounts of 6C and 7G match within the deviation tolerance value A, and the inclination of the movable frame 1 is within the tolerance value.

Also, in the above explanation, as can be easily understood, the movable frame 1
After the start of movement, the difference between the movement amount of the reference ram 4C and the movement amount of the other rams 5C, 6C, and 7C is always within the deviation tolerance value, and the tilt of the movable frame 1 is within the tolerance value. , the output signal to each electro-hydraulic servo amplifier 15 to 18 is reference speed B, and each ram 4C, 5C, 6G,
The operating speeds of 7C are similar.

FIG. 3 shows a second embodiment in which the present invention is applied to a 4-cylinder, 2-pump type pullback extrusion press, in which a hydraulic pump 11 is connected to an upper hydraulic cylinder 5.6 and a lower hydraulic cylinder 4.7. Pressure oil is supplied from a hydraulic pump 10, respectively. Furthermore, the two detectors 20 and 21 detect the amount of movement of the upper right corner and the lower left corner of the movable frame 1, respectively.

FIG. 4 shows a third embodiment in which the present invention is applied to a three-cylinder, three-pump type pullback extrusion press. Further, hydraulic cylinders 4 are respectively interposed in the lower lateral central portion, and pressure oil is supplied to each hydraulic cylinder 4, 5, 6 from each hydraulic pump 10, 11, 12. Furthermore, the three detectors 20, 21, and 22 detect the amount of movement of the upper right corner and the lower left and right corners of the movable frame 1.

FIG. 5 shows a fourth embodiment in which the present invention is applied to a two-cylinder, two-pump type pullback extrusion press.
A pair of upper and lower hydraulic cylinders 4.5 are interposed between the movable frame 1 and the cylinder frame 3, and pressure oil is supplied to each hydraulic cylinder 4.5 from each hydraulic pump 10.11, respectively. Furthermore, the two detectors 20 and 21 detect the amount of movement of the upper right corner and the lower left corner of the movable frame 1, respectively.

Note that in the second to fourth embodiments described above, the same control as in the first embodiment is performed.

In the embodiment, each setter and each pulse encoder are of digital type, but the same processing can be performed even if they are of analog type. In addition, various calculations were performed using the calculation function of the PC, but this is an example of using a PC for sequence control of a press, and even if each calculation was performed by an independent calculation unit, good. Furthermore, in the embodiment, the cumulative count of pulses of one pulse encoder is used as a reference value, and this is compared with the cumulative count of pulses of other pulse encoders, but the reference value cannot be set externally. Then, this reference value may be compared with the cumulative count of pulses of each pulse encoder. In addition, in the embodiment, the hydraulic pump is of a variable displacement type in order to control the amount of pressure oil supplied to the hydraulic cylinder. It may also be provided with a flow rate regulating valve.

Further, the present invention is applicable to various presses other than pull-hack type extrusion presses.

As described in detail above, the present invention detects the inclination of the movable frame by the detection means, and adjusts the amount of pressure oil supplied to the hydraulic cylinder by the control means when the inclination detected by the detection means is equal to or greater than an allowable value. By increasing or decreasing the operating speed of the hydraulic cylinder, the inclination of the movable frame can be kept within the allowable value, so the inclination of the movable frame can be kept within the allowable value, and the movable frame can be moved smoothly, making it easier for the press. It is possible to prevent the occurrence of vibration or the application of unreasonable force, and it is possible to obtain a product with high precision. The present invention has the following advantages and is of great practical benefit.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a simplified perspective view of an extrusion press without also showing the control system, and FIG.
The figure is a block diagram showing the inclination control means of the movable frame, and each figure of FIGS. 3 to 5 is a simplified perspective view of an extrusion press also showing the control system showing each of the second to fourth embodiments of the present invention. be. 1-movable frame, 2-guide, 3-cylinder frame, 4-7-hydraulic cylinder, 10-13-hydraulic pump,
15-18-Electro-hydraulic servo amplifier, 20-23-Detection 1 exit, 25-Speed setter, 26-Deviation tolerance value setter, 3
8- Programmable controller (PC). Patent applicant Kobe Co., Ltd.! ! Steelworks 2

Claims (1)

[Claims] 1. In a press in which a movable frame is moved by a plurality of hydraulic cylinders supplied with pressure oil from a plurality of hydraulic pumps, the inclination of the movable frame is detected by a detection means, and the inclination of the movable frame is detected by a control means. A movable frame in a press characterized in that the inclination of the movable frame is kept within the allowable value by adjusting the amount of pressure oil supplied to the hydraulic cylinder and increasing/decreasing the operating speed of the hydraulic cylinder when the inclination is above the allowable value. Tilt control method.