JP2002066799A - Press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press capable of minutely controlling the load, position and speed of the cylinder rod of fluid pressure cylinder equipment. SOLUTION: A press 1 has fluid pressure cylinder equipment 2, a fluid circuit system 16 for driving the fluid pressure cylinder equipment 2, and a control system for controlling the load, position and speed of the cylinder rod 4 of the fluid pressure cylinder equipment 2 according to a predetermined program and for making the cylinder rod 4 perform a pressure increasing or reducing action. The control system performs analog control of the load, position and speed of the cylinder rod 4 by controlling a pump unit 8, and performs digital control of a pressure relief valve 24 so as to perform ultra-low speed control and ultra-low load control of the cylinder rod 4. When the control value of the cylinder rod 4 is consistent with the target value of the program, the action of detecting the load, position and speed of the cylinder rod 4 and the comparison operation of the detected data continue, while all the actions of the fluid apparatuses belonging to the fluid circuit system 16 are brought to a stopped state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press device capable of arbitrarily controlling the load, position and speed of a cylinder rod of a hydraulic cylinder device.

[0002]

2. Description of the Related Art A fluid pressure control device capable of arbitrarily changing the pressing force of an actuator such as a cylinder rod of a fluid pressure cylinder device during operation of the cylinder rod has been developed. For example, the pulsed fluid pressure control device disclosed in Japanese Patent Publication No. 7-109255 has the following configuration. That is, the pressure fluid supplied from the pump to the actuator having the large-diameter piston is also supplied to the block in which the small-diameter actuator is inserted, and presses the actuator while pressing the actuator by the pressure spring of the elasticity conversion device. Is balanced by a counter spring which opposes the pressurization of the pressure spring and the weight of other components, thereby making it possible to reduce the pressing force of the actuator to zero. Therefore, the pressure applied to the actuator by the pressure spring of the elasticity conversion device can be changed from zero to an arbitrary magnitude.

In this fluid pressure control device, the position where the pressing force becomes zero or the minimum is set as the origin of the position support member, the on-off valve is closed at the origin position, and the on-off valve is moved when the actuator presses the pressing spring to move. After adjusting to open, the pressing force of the pressure spring is adjusted manually or by a control device. Then, by moving the actuator plate with a small-diameter actuator against the set pressure of the pressure spring, the on-off valve is opened and closed, and fluid pressure is supplied to the actuator in a pulsed manner.

Therefore, according to this fluid control device, the pressure of the fluid supplied to the actuator is maintained, and
Based on the pressure sensor signal and the specified pressure value,
The pressing force of the pressure spring can be changed and controlled to control the pressing force of the large-diameter actuator. In addition, a leak valve is provided in a fluid path for maintaining pressure, and when the fluid pressure is reduced, the fluid is discharged from the leak valve, so that the pressure reducing operation can be performed at a higher speed.

[0005] However, the above-mentioned conventional fluid pressure control device is configured so that the pressing force of the actuator is made zero by using the pressurization of the mechanical elasticity conversion device. It is difficult to maintain a precise control operation, and since the fluid pressure supplied to the actuator changes in a pulsed manner, there is a problem that a fine control operation cannot always be obtained.

[0006] In general, servo control is sometimes used for hydraulic equipment. Servo control has very high dynamic characteristics and is advantageous when a large cylinder device or the like is operated at high speed. However, when the pump and the servo valve are controlled using the hydraulic servo control, the pump and the servo valve cannot be stopped, so that the energy loss of the entire apparatus increases. Further, in the control by the servo valve, since the servo valve is operated by using the differential pressure while always supplying the hydraulic pressure, the circuit efficiency is about 20 to 30% and the energy loss is large. Further, the servo valve control has a large device body and requires a cooling system and an oil conditioner for managing a large filter device.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to control the pressure of fluid supplied to and discharged from a hydraulic cylinder device by using both digital control and analog control. Press equipment that enables fine control of load, position, and speed, and that can reduce the size and weight of fluid equipment by using ultra-high pressure, and can also save power. Is to provide.

[0008]

According to the present invention, there is provided a press apparatus comprising: a hydraulic cylinder device; a hydraulic circuit system for driving the hydraulic cylinder device;
According to a predetermined program, control the load, position and speed of the cylinder rod of the hydraulic cylinder device,
A control system for causing the cylinder rod to perform a desired pressurizing operation or a depressurizing operation, wherein the fluid circuit system supplies and discharges a working fluid so as to operate the fluid pressure cylinder device steplessly. A pump, a driving device for the pump, and a pressure relief valve, wherein the control system controls the driving device for the pump to perform analog control of a load, a position, and a speed of the cylinder rod; Digitally controlling the pressure relief valve to perform speed control and ultra-low load control, and furthermore, when the control value of the cylinder rod matches the target value of the program, the fluid device belonging to the fluid circuit system While the operations are all stopped, the detection operation of the load, the position, and the speed and the comparison operation of the detection data are continued.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. The press device 1 of the present invention has a press frame 3 provided with a double-acting hydraulic cylinder device 2, and has a cylinder rod 4 of the double-acting hydraulic cylinder device 2. Cylinder rod 4
A stroke detector 5 for detecting a displacement of the cylinder rod 4 is connected to an upper end of the cylinder rod 4, and a load cell 6 for measuring a load is attached to a lower end of the cylinder rod 4. The press frame 3 is mounted on a base housing 7,
The hydraulic pump unit 8 is housed inside the base housing 7. An electric control unit housing 9 is juxtaposed with the base housing 7, and a control unit 10 including a control computer is arranged on the electric control unit housing 9. In FIG. 1, 11 is a touch panel display, 12 is an operation panel,
Shown respectively.

FIG. 4 shows a hydraulic system of the double-acting hydraulic cylinder device 2. The hydraulic pump unit 8 has a high-pressure hydraulic pump 8a and a low-pressure hydraulic pump 8b, and these pumps 8a, 8b
Is connected to the motor 8c. The motor 8c is controlled by the inverter 8d. The hydraulic pump unit 8 includes a high-pressure hydraulic pump 8a, a low-pressure hydraulic pump 8b, a motor 8c,
It is constituted by an inverter 8d. High pressure hydraulic pump 8
The oil reservoir 13 is disposed below the oil reservoir 13 and the low-pressure hydraulic pump 8b. These pumps 8a and 8b filter the oil (not shown) stored in the oil reservoir 13 into the oil filter 1.
The hydraulic fluid is supplied to the hydraulic circuit 16 via 4 and 15.

The hydraulic circuit 16 is configured as shown in FIG. The hydraulic circuit 16 includes a high-pressure relief valve 17, a low-pressure relief valve 18, an electromagnetic switching valve 19, check valves 20, 21, 2,
2. Special pressure relief valve 23, high pressure hydraulic pressure adjustment valve (digital pressure control valve) 24, rotation angle control motor 25, pressure sensor 2
6, 27 and solenoid valves 28 and 29. In the figure, 30
Is a pressure indicator of the special pressure relief valve 23.

FIG. 5 shows an electric control diaphragm of the double-acting hydraulic cylinder device 2. As shown in FIG.
6 and 27, the detection signal of the load sensor 6, and the detection signal of the position sensor 5 are amplifier / A / D converters 31, 3
2 and 33 are input to the I / O interface of the microcomputer control device 34. The hydraulic pump motor 8c is
The microcomputer controller 34 via the PWM inverter 35
Is input to the I / O interface. Similarly, the digital pressure control valve motor 25 includes a driver unit 36
Is input to the I / O interface of the microcomputer control device 34 via the. The microcomputer control device 34 operates by receiving power from an AC power supply of 100 volts. The microcomputer control device 34 is connected to the personal computer 37 and the touch panel display 10 via the external interface 11.

Hereinafter, the operation of the press apparatus 1 of the present invention will be described with reference to the production of a press-fitted part shown in FIG. 3 as an example. FIG.
, The dry-met bush 38 which is a press-fitting shaft
Attached to the lower end of the mandrel 39 as a pressure jig,
The press-fit body 40 is press-fitted into the press-fit hole 41. Mandrel 39
Is fixed to the cylinder rod 4 of the double-acting hydraulic cylinder device 2 via the load cell 6.

The press-fit body 40 is installed below the double-acting hydraulic cylinder device 2 of the press device 1 and the mandrel 39 is connected to the press-fit body 4.
Align with the press-fit hole 41 of No. 0 and attach it below the load cell 6. The drymet bush 38 is attached to the lower end of the mandrel 39, and both the high-pressure hydraulic pump 8a and the low-pressure hydraulic pump 8b are operated. The discharge amount of the hydraulic pumps 8a and 8b can be arbitrarily selected according to the rotation speed of the motor 8c determined by the inverter 8d. Therefore,
By controlling the rotation speed of the motor 8c, the operation speed of the cylinder rod 4 of the double-acting hydraulic cylinder device 2 can be changed steplessly.

Until the drymet bush 38 moves directly above the press-fit hole 41, both the high-pressure hydraulic pump 8a and the low-pressure hydraulic pump 8b are rotated to lower the cylinder rod 4 at high speed. By opening and closing the electromagnetic switching valve 19,
The hydraulic oil discharged from the low-pressure hydraulic pump 8b can be prevented from being supplied to the double-acting hydraulic cylinder device 2.
That is, when hydraulic oil is supplied from the low-pressure hydraulic pump 8b to the double-acting hydraulic cylinder device 2, the solenoid valve SV3 of the electromagnetic switching valve 19 is excited to open the electromagnetic switching valve 19. Thus, the hydraulic oil discharged from the low-pressure hydraulic pump 8b flows through the check valve 20 into the head-side chamber 2a of the double-acting hydraulic cylinder device 2. When the electromagnetic switching valve 19 is closed, the hydraulic oil discharged from the low-pressure hydraulic pump 8 b does not flow to the check valve 20, but is returned to the oil reservoir 13 through the low-pressure relief valve 18. In a state where the electromagnetic switching valve 19 is opened, the high-pressure hydraulic pump 8a is also operating, so that the hydraulic oil discharged from the high-pressure hydraulic pump 8a passes through the check valve 21 to the head side of the double-acting hydraulic cylinder device 2. The cylinder rod 4 flows into the chamber 2a and merges with the hydraulic oil discharged from the low-pressure hydraulic pump 8c, so that the cylinder rod 4 can be pushed down at a high speed.

The operation stroke, that is, the position of the cylinder rod 4 is determined by a displacement sensor linked to the cylinder rod 4,
That is, the stroke can be detected from the absolute origin position by the stroke detector 5. Various control operations of the press device 1 are performed at predetermined stroke positions.
That is, the cylinder rod 4 is
The cylinder rod 4 can be operated at a high speed until the cylinder rod 4 approaches 8, and the operation of the cylinder rod 4 can be reduced by, for example, 0.5 mm before the cylinder rod 4 comes into contact with the drymet bush 38. Cylinder rod 4
When the cylinder switch 4 is at an arbitrary position, the hydraulic oil from the low-pressure hydraulic pump 8b is supplied to the double-acting hydraulic cylinder device 2 by holding the electromagnetic switching valve 19 at the neutral position. Can be stopped. When the low-pressure hydraulic pump 8b is in such an operation stop state, only the high-pressure hydraulic pump 8a is operating alone, and the cylinder rod 4 operates at a very low speed. At this time, by further controlling the inverter 8d to control the rotation speed of the motor 8c, the cylinder rod 4
Can be operated at a very low speed. Cylinder rod 4
The ultra-small speed operation of the
This is necessary in order to prevent problems such as galling between the drymet bush 38 and the press-fitting hole 41 when the press-fitting is performed. The elements required for the so-called slow touch to prevent the occurrence of galling or the like between the drymet bush 38 and the press-fitting hole 41 are such an ultra-slow operation of the cylinder rod 4 and a cylinder. Thrust control of the rod 4 with a very low load is roughly classified into two types.

The thrust control of the cylinder rod 4 with a very low load is performed by a special pressure relief valve 23. This special pressure relief valve 23
Functions to control a low pressure that cannot be compensated by pressure control by a high-pressure hydraulic adjustment valve (digital pressure control valve) 24 that controls a high load (that is, a high pressure). The high-pressure hydraulic adjustment valve (digital pressure control valve) 24 is servo-controlled by a rotation angle control motor 25, and controls the flow rate of hydraulic oil discharged from the high-pressure hydraulic pump 8a. On the other hand, the control operation of the special pressure relief valve 23 is a kind of digital control, and is ON / OF.
The pressure is controlled by F control. Press device 1 of the present invention
As shown in FIG. 4, the pump unit 8 controls the discharge amount by an inverter 8d. Therefore, the control of the hydraulic oil amount discharged from the pump unit 8 is performed by the inverter 8d.
And a digital control by the special pressure relief valve 23.
In this fuzzy control, as shown in FIG. 4, an analog signal obtained by the pressure sensors 26 and 27, the load sensor 6, and the position sensor 5 is converted into a digital signal by an A / D converter, and then the microcomputer controller 34 A voltage signal of the hydraulic pump motor 8c is input to the microcomputer controller 34 via the PWM inverter 35, and a rotation angle control motor 25 for the digital pressure control valve 24 is input.
Are input to the microcomputer control device 34 via the driver unit 36, and these signal values are subjected to high-speed comparison calculation with the control value in the microcomputer control device 34. The correction coefficient and the control output signal after the calculation are
The double-acting hydraulic cylinder device 2 is controlled by the motor 8c of the hydraulic pump unit 8 and the motor 25 of the digital pressure control valve 24 at optimum values. In this control, the control value and the data value are compared in real time, and the corrected correction coefficient and the control output signal are subjected to high-speed feedback control.

The cylinder rod 4, which is controlled so that the drymet bush 38 soft-touches the press-fit hole 41, is controlled by the control system described above with a target set value programmed in advance. In this control, speed control, position control, and load control of the cylinder rod 4 can be managed and controlled. These control elements can be controlled alone or in combination with some control elements. By the way, dry met bush 38
Soft-touches the press-fit hole 41, the drymet bush 38 is inserted into the press-fit hole 41 under the condition of the pre-programmed press-fit pattern. In the case of this embodiment, a speed control mode and a load control mode are used. For example, in the first step after soft touch, press-fit speed is 1mm
/ Sec, press-fit load is 10KN, insertion depth is programmed to 5mm. In the second step following the first step, press-fit speed is 5mm / sec, press-fit load is 50KN, press-fit bottom depth is 50.0 Can be programmed with mm. Specifically, the high-pressure hydraulic pump 8a is controlled at 1 mm / sec, the displacement is detected by the stroke detector (displacement sensor) 5, and the speed is converted by the microcomputer control device 34, whereby the current speed of the cylinder rod 4 is reduced. Is calculated. Then, the speed is corrected until the speed matches the set value.

The speed correction control of the cylinder rod 4 is performed by controlling the inverter 8d to variably adjust the discharge amount of the high-pressure hydraulic pump 8a. The numerical values of the sampling time and the correction output accuracy of the data processing can be changed as appropriate by inputting the numerical values through the personal computer 37 or the touch panel 10.

The press-fit load of 10 KN can be controlled by a high-pressure hydraulic pressure control valve (digital pressure control valve) 24 for controlling a high load (high pressure) and a rotation angle control motor 25. At this time, it is not necessary to operate the special pressure relief valve 23 that performs the ultra-low load control, and the special pressure relief valve 23 is OFF. The load at the time of press-fitting is determined by the processing accuracy, frictional resistance, press-fitting speed and the like of the drymet bush 38 and the press-fitting hole 41. The press device 1 operates so as to regulate the maximum load of 10 KN by the high-pressure hydraulic adjustment valve (digital pressure control valve) 24 so that the cylinder rod 4 is in a standby state while maintaining the upper limit load. be able to.

When the cylinder rod 4 matches the target value determined by the program, all the hydraulic devices are stopped. However, the signal system for various data detection always performs a comparison operation process with a control value.
The operation of these signal systems is continued without stopping.

High pressure hydraulic pressure control valve (digital pressure control valve) 2
4 has a poppet check type structure, so that the pressure in the hydraulic circuit can be maintained with almost no leakage from the inside. During stoppage, in order to maintain and maintain the pressure in the hydraulic circuit without operating the pump unit 8, the set value of the high-pressure hydraulic adjustment valve (digital pressure control valve) 24 is set higher than the target pressure by the rotation angle control motor 25. Is also set slightly higher. However, the double-acting hydraulic cylinder device 2
The hydraulic pressure inside the head side chamber 2a is controlled so as to be the same as the set value of the target value when passing through the high pressure hydraulic pressure adjusting valve (digital pressure control valve) 24. Also,
The high-pressure hydraulic adjustment valve (digital pressure control valve) 24 detects the pressure at which the pump unit 8 stops or the load on the cylinder rod 4, and operates so as to increase the pressure to a position where internal leakage is eliminated. This operation is controlled by the microcomputer controller 34. The rotation angle control motor 25 is restrained by an electromagnetic brake (not shown), and the rotation angle at the stop position is maintained. Since the high-pressure hydraulic pressure adjusting valve (digital pressure control valve) 24 is also provided with a rotation angle holding mechanism (not shown), it is necessary to hold the set pressure without using the electromagnetic brake of the rotation angle control motor 25. Can be. The speed control and load control in the press-fitting process are performed as described above. The operation state of each step is written in the memory of the microcomputer control device 34, and control abnormalities during the operation and the process of the step can be stored as digital data.

The press-fitting operation in the second step is performed in the same manner as in the first step. In the second step, the press-in speed is 5 mm / sec, the press-in load is 50 KN, and the depth with the press-in bottom is 50.0 mm. However, in the second step, the bottom of the press-fitted part is confirmed by the load and the position. In order to determine whether the drymet bush 38 has been incorporated into the press-fit hole 41 with a correct positional relationship, it is necessary to confirm the position and the load, and the predicted bottomed stroke 50.0 mm is determined, and the predicted press-fit load is determined. Is also determined. Therefore, the press-fit state can be determined by controlling these two parameters and measuring actual data. That is, the measurement of the bottomed load can be performed by the load cell 6 attached at a position where the thrust of the cylinder can be measured. Load cell 6
Can measure not only the bottomed load but also the load in all the steps when the load is applied. These measured data are written to the memory of the microcomputer control device 34. The stroke is detected from the absolute reference value by the stroke detector (displacement sensor) 5 of the double-acting hydraulic cylinder device 2 as described above. This measurement data is also stored in the microcomputer controller 3
4 is written to the memory. The values of these actually measured data can be changed by the personal computer 37 or the touch panel 10 depending on the data length. For example, it is possible to compare whether the sample pattern stored in the memory in advance matches the current process pattern, or whether the specified press-fitting accuracy has been reached.

The above is an example in which the press apparatus 1 of the present invention is operated in the press-fitting step. The press apparatus 1 can perform load control, position control, and speed control not only on the pressurizing side but also on the depressurizing side. it can. Control on the decompression side is required when pressing materials such as powder and glass. Since the load attenuation pattern has a large effect on the crystal of the molding material, it is necessary to make the load attenuation pattern appropriate depending on the properties of the crystal of the material. Basically, the same applies to the pressurized side, but the press device 1 has a function that can be controlled by both.

In order to attenuate the load in the press device 1, the pressure in the head side chamber 2a of the double-acting hydraulic cylinder device 2 is reduced. This is performed by operating the high-pressure hydraulic adjustment valve (digital pressure control valve) 24 on the pressure drop side to attenuate the pressure. As a result, the thrust of the cylinder rod 4 is attenuated, and the attenuation speed can be changed by controlling the speed of the rotation angle control motor 25 of the high-pressure hydraulic adjustment valve (digital pressure control valve) 24.

In order to stabilize the operation of the cylinder rod 4 when positioning the cylinder rod 4, a balance pressure can be used. That is, the operation in the direction in which the cylinder rod 4 extends can be achieved by increasing the discharge amount of the pump unit 8, but in order to correct the position of the cylinder rod 4 in the direction in which the cylinder rod 4 contracts, the electromagnetic switching valve 19 must be operated. Switching to the SV4 side causes the hydraulic oil to flow into the cylinder rod side chamber 2b of the double acting hydraulic cylinder device 2. When the pressure in the cylinder rod side chamber 2b increases, the pressing load on the cylinder rod 4 decreases, and the cylinder rod 4 is displaced in the contracting direction. Thereby, the minute displacement of the cylinder rod 4 can be controlled. On the other hand, when relatively large position control of 0.5 mm or more is performed, the discharge amount of the pump unit 8 is directly controlled without performing such balance control, and the high-pressure hydraulic adjustment valve (digital pressure control) is used. Valve 24). In FIG. 4, reference numerals 28 and 29 denote electromagnetic switching valves that return the hydraulic oil in the head-side chamber 2a and the cylinder-rod-side chamber 2b of the double-acting hydraulic cylinder device 2 to the oil reservoir 13 and perform a pressure holding function.

[0027]

As described above, according to the press apparatus of the present invention, the control of the fluid pressure supplied to and discharged from the hydraulic cylinder apparatus is performed by using both digital control and analog control. Load on the cylinder rod of the device,
Provided is a press device capable of finely controlling the position and speed, and also capable of reducing the size and weight of a fluid device by using an ultra-high pressure and reducing power consumption. can do.

[Brief description of the drawings]

FIG. 1 is an overall front view schematically showing a press device of the present invention.

FIG. 2 is a left side view of the press device of FIG.

FIG. 3 is a cross-sectional view of a dry-met bush and a press-fit hole for explaining an example of press-fitting a dry-met bush into a press-fit hole using the press device of the present invention.

FIG. 4 is a view showing one embodiment of a hydraulic circuit of the press device of the present invention.

FIG. 5 is a diagram showing one embodiment of a control system of the press device of the present invention.

[Description of reference numbers] 1 Press device 2 Double acting hydraulic cylinder device 4 Cylinder rod 5 Stroke detector 6 Load cell 8 Pump unit 10 Control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Isao Takahashi Inventor 1539, Kofunai, Sekijuku-cho, Higashi-Katsushika-gun, Chiba Prefecture F-term (reference) 4E088 JJ02 JJ04 4E089 EA01 EB01 EB02 EB03 EC01 ED03 EE01 EE04 EF02 FA01 FB03 FC03

Claims (1)

[Claims] 1. A fluid pressure cylinder device, a fluid circuit system for driving the fluid pressure cylinder device, and a load, a position and a speed of a cylinder rod of the fluid pressure cylinder device are controlled according to a predetermined program. A control system for causing the cylinder rod to perform a desired pressurizing operation or a depressurizing operation, wherein the fluid circuit system supplies and discharges a working fluid so as to operate the fluid pressure cylinder device steplessly. A pump, a driving device for the pump, and a pressure relief valve, wherein the control system controls the driving device for the pump to perform analog control of the load, position, and speed of the cylinder rod, and Digitally controlling the pressure relief valve so as to perform the slow speed control and the ultra-low load control, and furthermore, the control value of the cylinder rod coincides with the target value of the program. A press apparatus, wherein the operation of the fluid devices belonging to the fluid circuit system is all stopped, and the detection operation of the load, the position, and the speed and the comparison operation of the detection data are continued. .