JPH07241699A - Method and device for correcting bottom dead center displacement of press machine - Google Patents

Abstract

PURPOSE:To correct the bottom dead center displacement due to temp. change so as to enable high precision press work. CONSTITUTION:The bottom dead center displacement correcting device of press machine is provided with a slide displacement sensor 10 to detect a displacement of bottom dead center at each stroke and to output a displacement detected signal, a proportional electromagnetic pressure control valve 14 to control a pressure of pressurized oil supplied to a hydraulic jack extending/retracting a frame 13 and a control means which controls the proportional electromagnetic pressure control valve 14 based on the displacement detected signal from the slide displacement sensor 10 and corrects a displacement of the bottom dead center by extending/retracting the frame 13 in axial direction while varying a jack force of the hydraulic jack 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank press machine used for press sheet metal working such as drawing, punching and bending. More specifically, it corrects bottom dead center displacement due to temperature change of the press machine. The present invention relates to a device and a method thereof.

[0002]

2. Description of the Related Art Conventionally, in a crank type press machine used for press sheet metal working such as drawing, punching, bending, etc., a frame is affected by a change in ambient temperature, heat generated by a press drive unit and the like. , The slide expands and contracts, and the bottom dead center of each stroke is displaced, so it is difficult to maintain quality in the press processing of products that require high accuracy, so it is necessary to inspect the press products during the process. It is necessary to adjust the height of the mold with shims as necessary.

[0003]

In the above-mentioned conventional crank press machine, since the bottom dead center is displaced due to the thermal effect, it is necessary to maintain the quality of products requiring high accuracy during the machining process. Since it is necessary to inspect the pressed product and frequently adjust the height of the mold with a shim or the like, there is a problem that there is a limit to improvement in productivity and yield.

[0004]

In order to solve the above problems, the present invention presses the upper die and the lower die when the slide is moved up and down by the crank mechanism and operates the hydraulic jack to form the frame. A bottom dead center displacement correction device configured to expand and contract in the axial direction, a displacement sensor that detects a displacement at the bottom dead center and outputs a displacement detection signal, and pressure oil that is supplied to the hydraulic jack. Pressure adjusting means for adjusting the pressure of the hydraulic jack and the pressure adjusting means on the basis of the displacement detection signal from the displacement sensor to vary the jack force of the hydraulic jack to expand and contract the frame. And a control means for correcting the displacement of the dead point.

Alternatively, when the slide is moved up and down by the crank mechanism, the upper die and the lower die are pressed, and the frame is expanded and contracted in the axial direction by the hydraulic jack. A displacement sensor that detects the displacement of the top dead center and outputs a displacement detection signal
A pressure adjusting means for adjusting the pressure of the pressure oil supplied to the hydraulic jack, and the pressure adjusting means is controlled based on a displacement detection signal from the displacement sensor to vary the jack force of the hydraulic jack. And a control means for correcting the displacement of the bottom dead center by expanding and contracting the frame.

[0006]

According to the bottom dead center displacement compensating device of the above-mentioned press, the control means has the bottom dead center or the top dead center from the displacement sensor caused by the expansion and contraction of the frame and the slide accompanying the temperature change. The pressure adjusting means is controlled on the basis of the point displacement detection signal, the jack force of the hydraulic jack is varied, and the frame is expanded and contracted to correct the displacement of the bottom dead center during press working.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing a state before molding of the crank press, and FIG. 2 shows a state after molding of the crank press and a hydraulic pressure and control system of the same. As shown in FIG. 1, a slide drive motor 25 is attached to the upper portion of the press body 1, and when the slide drive motor 25 is driven, the connecting rod 9 is driven by a crank mechanism. The slide 5 attached to the connecting rod 9 is moved up and down.

An upper die 7 is attached to the slide 5, and when the slide 5 is lowered, the upper die 7 and the frame 1
The material to be pressed is pressed between the lower die 8 fixed to the bolster 6 and attached to the bed surface of No. 3.

On the other hand, a plurality of hydraulic jacks 2 are mounted on the top of the press body 1. The hydraulic jack 2 has a mechanism for restraining the frame 13 together with the tie rod 3 and the nut 4.

The bracket 1 is attached to the bed surface of the frame 13.
0A is fixed, and a slide displacement sensor-10 that detects displacement of the bottom dead center of the slide 5 is attached to the upper portion of the bracket 10A. On the other hand, a dog 11 is attached to the side surface of the slide 5, and the slide displacement sensor 10 detects the position of the dog 11 when the slide 5 reaches the bottom dead center, thereby detecting the bottom dead center displacement amount. It is configured to be able to.

Next, the hydraulic system and the control system will be described with reference to FIG. As shown in FIG. 2, the slide displacement sensor 10 is connected to an amplifier 19, and the amplifier 19 is connected to a digital panel meter 20. This digital panel meter 20
The analog signal output from the amplifier 19 is converted into a digital signal and output.

A hydraulic source of a hydraulic circuit for supplying required pressure oil to the plurality of hydraulic jacks 2 is a pump 16 driven by a motor M, and the pressure oil sent from the pump 16 is a system. -Supplied to each hydraulic jack 2 under pressure control by the proportional electromagnetic pressure control valve 14 via the can valve 15.

On the other hand, the control circuit of the press control device 32 (see FIG. 3), which will be described later, excites the jack pressure release solenoid valve 21 to open the jack pressure pilot check valve 22 to open oil in the pressure release cylinder 27. When it is confirmed that the pressure release cylinder reverse limit switch 24 is turned on, the pressure release cylinder opening solenoid valve 28 is excited to open the pressure release cylinder pilot check valve 29, and Let the oil escape to the tank and adjust the pressure of the hydraulic jack 2.

FIG. 3 is a pressure control block diagram of the hydraulic jack 2 for correcting the bottom dead center displacement. As shown in FIG. 3, a processor CPU is used as the center of pressure control of the hydraulic jack 2, and the processor CPU has a random access memory RAM and a read only memory ROM.
And are connected. Also, a slide displacement sensor-1 via the amplifier 19 and the digital panel meter-20.
An input interface 30 for inputting signals from 0 and various operation signals from the press controller 32, and an output interface 31 for outputting signals from the processor CPU to the outside. Are connected.

A press control device 32 for driving the main body of the press machine 1 is connected to the input interface 30, and a pressure control start signal from the press control device 32 is input thereto. A press controller 32 is also connected to the output interface 31, and a processor CPU outputs an operation preparation signal and the like to the press controller 32 via the output interface 31. The press control device 32 includes the jack pressure release solenoid valve 21,
A pressure release cylinder 27, a pressure release cylinder release solenoid valve 28, etc. are built in.

FIG. 4 is a flow chart for controlling the pressure of the hydraulic jack 2. In step S1, the power of the press control device 32 that drives the main body of the press machine 1 is turned on and the power is supplied to the processor CPU, whereby the system is initialized. In step S2, it is determined whether or not the operation of the processor CPU is normal. If the operation is abnormal, in step S3 the defect is removed and corrected to normal. In step S4, the press operation is started.

In step S5, the signal from the slide displacement sensor 10 is input to the peak hold of the bottom dead center of the slide 5 for each stroke. In step S6, the corrected jack pressure is calculated based on the variation of the bottom dead center of each stroke, and the jack pressure is output to the pressure controller 17 as a digital value.

In step S7, the pressure controller 17 receives the pressure detection signal from the pressure sensor 18 as a signal.
When the proportional electromagnetic pressure control valve 14 is energized while being driven back, as shown in step S8, the proportional electromagnetic pressure control valve 1
4, the hydraulic jack 2 expands and contracts the frame 13 so as to converge the variation of the bottom dead center.

As described above, when the processor CPU recognizes that there is a variation in the bottom dead center from the signal from the slide displacement sensor 10 for each stroke, the variation with respect to the pressure controller 17 is detected. In order to output jack pressure data that converges the pressure, the pressure controller 17 feeds back the pressure detection signal from the pressure sensor 18 and energizes the proportional electromagnetic pressure control valve 14,
The pressure of the hydraulic jack 2 is corrected and the frame 13 is expanded and contracted so that the variation of the bottom dead center is reduced.

Next, the slide displacement sensor 10 detects the top dead center of the slide 5 for each stroke, and the slide 5
The control of the second embodiment in which the pressure of the hydraulic jack 2 is corrected according to the variation of the top dead center and the frame 13 is expanded and contracted so that the variation of the bottom dead center during the press working is reduced will be described.

Generally, when press working with a press machine, the working force is not constant due to the structure of the upper die 7 and the lower die 8 or the plate thickness of the press material or the variation of the material, and it varies within a certain range. Happens. That is, the bottom dead center is likely to vary from press to press. This means that the amount of heat generated in the bearing such as the crankshaft changes depending on the magnitude of the working force, and as a result, the bottom dead center displacement during press working due to thermal displacement is promoted. Therefore, when the above load conditions are not constant, the slide 5 detects the slide position at the top dead center (upper limit position) that is not affected by the load, as a means for correcting the bottom dead center displacement during press working due to heat. Then, the pressure of the hydraulic jack 2 is corrected according to the variation of the top dead center of the slide 5, and the frame 13 is expanded and contracted so that the variation of the bottom dead center during the press working is reduced.

As shown in FIG. 5, a bracket 10A is fixed to the bed surface of the frame 13 of the press body 1, and a slide for detecting the displacement of the top dead center of the slide 5 is mounted on the upper portion of the bracket 10A. A displacement sensor-10 is attached. On the other hand, a dog 11 is attached to the side surface of the slide 5, and the slide displacement sensor 10 detects the position of the dog 11 when the slide 5 reaches the top dead center, thereby detecting the top dead center displacement amount. It is configured to be able to.

FIG. 6 is a control flowchart of the processor CPU that corrects the pressure of the hydraulic jack 2 according to the variation of the top dead center of the slide 5 and converges the variation of the bottom dead center. This control will be described below with reference to the same flow chart. In step S1, the power of the press control device 32 that drives the main body of the press machine 1 is turned on and the power is supplied to the processor CPU, whereby the system is initialized. In step S2, it is determined whether or not the operation of the processor CPU is normal. If the operation is abnormal, in step S3 the defect is removed and corrected to normal. In step S4, the press operation is started.

In step S5, the peak position of the top dead center of the slide 5 for each stroke is determined by inputting a signal from the slide displacement sensor 10. In step S6, the corrected jack pressure is calculated based on the variation of the top dead center of each stroke, and the jack pressure is output to the pressure controller 17 as a digital value.

In step S7, the pressure controller 17 receives the pressure detection signal from the pressure sensor 18 as a signal.
When the proportional electromagnetic pressure control valve 14 is energized while being driven back, as shown in step S8, the proportional electromagnetic pressure control valve 1
4, the hydraulic jack 2 expands and contracts the frame 13 so as to converge the variation of the bottom dead center of the slide.

As described above, when the processor CPU recognizes that there is a variation in the top dead center of the slide 5 from the top dead center detection signal from the slide displacement sensor 10 for each stroke, the pressure controller. In order to output the jack pressure data that converges the variation to the pressure sensor 17, the pressure controller 17 controls the proportional electromagnetic pressure control valve 14 while feeding back the pressure detection signal from the pressure sensor 18. The energization is controlled, the pressure of the hydraulic jack 2 is corrected, and the frame 13 is expanded and contracted so that the variation of the bottom dead center of the slide 5 during press working is reduced.

[0027]

As described above, according to the present invention, when the slide is moved up and down by the crank mechanism, the upper die and the lower die press work, and the hydraulic jack allows the frame to expand and contract in the axial direction. In the configured press machine,
A displacement sensor that detects the displacement of the bottom dead center or the top dead center and outputs a displacement detection signal, a pressure adjusting unit that adjusts the pressure of the pressure oil supplied to the hydraulic jack, and the displacement sensor.
Control means for controlling the pressure adjusting means on the basis of a displacement detection signal from the control means, and varying the jacking force of the hydraulic jack to expand / contract the frame so as to correct the displacement of the bottom dead center during press working. Since it is equipped with a displacement sensor due to expansion and contraction due to temperature changes such as frames and slides
Control the pressure adjusting means based on the displacement detection signal from
By changing the jack force of the hydraulic jack to expand and contract the frame, it is possible to correct the displacement of the bottom dead center during press working.

[Brief description of drawings]

FIG. 1 is a front view showing a state before molding of a crank press according to a first embodiment.

FIG. 2 is a hydraulic system and control system diagram of the crank press machine of the first embodiment.

FIG. 3 is a block diagram of bottom dead center displacement correction control.

FIG. 4 is a flowchart of a bottom dead center displacement correction control flowchart of the first embodiment.

FIG. 5 is a front view showing a state before molding of the crank press of the second embodiment.

FIG. 6 is a bottom dead center displacement correction control flow chart of the second embodiment.

[Explanation of symbols]

 1 Pressing Machine Main Body 2 Hydraulic Jack 3 Tie Rod 4 Nut 5 Slide 6 Bolster 7 Upper Model 8 Lower Model 9 Connecting Rod 10 Slide Displacement Sensor-11 Dog 13 Frame 14 Proportional Electromagnetic Pressure Control Valve 15 Sequence Valve 16 Pump 17 Pressure Controller 18 Pressure sensor 19 Amplifier 20 Digital panel meter 21 Jack pressure release solenoid valve 22 Jack pressure pilot check valve 23 Pressure release cylinder forward end limit switch 24 Pressure release cylinder backward end limit switch 25 Slide drive mode 27 Pressure release cylinder 28 Pressure release cylinder release solenoid valve 29 Pressure release cylinder pilot check valve

Claims (5)

[Claims] 1. A press machine configured to press the upper die and the lower die when the slide is moved up and down by a crank mechanism and to expand and contract the frame in the axial direction by a hydraulic jack. Displacement sensor for detecting the displacement of the pressure sensor and outputting a displacement detection signal, pressure adjusting means for adjusting the pressure of the pressure oil supplied to the hydraulic jack, and the pressure adjustment based on the displacement detection signal from the displacement sensor. Bottom dead center displacement of the press machine, which comprises means for controlling the means and varying the jack force of the hydraulic jack to expand and contract the frame to correct the displacement of the bottom dead center. Correction device. 2. The bottom dead center displacement compensating device for a press machine according to claim 1, wherein the pressure adjusting means is a proportional electromagnetic pressure control valve. 3. A press machine configured to press the upper die and the lower die when the slide is moved up and down by a crank mechanism and to expand and contract the frame in the axial direction by a hydraulic jack. The bottom force of the press machine is corrected by controlling the jack force of the hydraulic jack in accordance with the displacement of the hydraulic jack to expand and contract the frame. 4. A press machine configured to press the upper die and the lower die when a slide is moved up and down by a crank mechanism and to expand and contract the frame in the axial direction by a hydraulic jack. Displacement sensor for detecting the displacement of the pressure sensor and outputting a displacement detection signal, pressure adjusting means for adjusting the pressure of the pressure oil supplied to the hydraulic jack, and the pressure adjustment based on the displacement detection signal from the displacement sensor. Bottom dead center displacement of the press machine, which comprises means for controlling the means and varying the jack force of the hydraulic jack to expand and contract the frame to correct the displacement of the bottom dead center. Correction device. 5. A press machine configured to press the upper die and the lower die when the slide is moved up and down by a crank mechanism and to expand and contract the frame in the axial direction by a hydraulic jack. The bottom force of the press machine is corrected by controlling the jack force of the hydraulic jack in accordance with the displacement of the hydraulic jack to expand and contract the frame.