JPH09329103A - Hydraulic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic device which can be driven and controlled by directly connecting a plurality of hydraulic actuators to a single hydraulic pump. SOLUTION: A hydraulic pump 1 is used which is driven by an electric motor 6 and can be rotated in both directions according to its forward or backward rotation. Ports 15 to 20 of each of the hydraulic actuators 12 to 14 are connected in parallel to both ports 2 and 4 of the hydraulic pump 1 through pipe lines 8 and 10, and electromagnetic valves 22 to 24 are provided in the pipe line 8 for each of the hydraulic actuators 12 to 14. The hydraulic actuators 12 to 14 to be driven are controlled by opening/closing of each of the electromagnetic valves 22 to 24, and the operating direction of the hydraulic actuators 12 to 14 is controlled by forward/backward rotation of the electric motor 6. Moreover, a positional sensor 36 is provided for detecting displacement of the single hydraulic actuator 12, and the electric motor 6 is controlled based on its signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic device for driving a hydraulic actuator with a hydraulic fluid from a hydraulic pump driven by an electric motor.

[0002]

2. Description of the Related Art Conventionally, a drive device which is directly driven by a servomotor has been used. However, when a large driving force is required, the hydraulic fluid from a hydraulic pump driven by the motor is used as a hydraulic actuator. Is used to obtain a large driving force by a hydraulic actuator. However, in hydraulic equipment, electric motors, hydraulic pumps,
A hydraulic tank, a control valve, and other hydraulic equipment are required, resulting in an increase in size. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 63-23002, a hydraulic pump capable of discharging a pressurized liquid by rotating in both directions is used, and the port of the hydraulic pump is directly connected to the port of the hydraulic actuator to drive the hydraulic pump. It is also known that the electric motor for controlling the electric motor is controlled to reduce the size.

[0003]

However, in such a conventional apparatus, although one hydraulic actuator can be driven by the electric motor and the hydraulic pump, when a plurality of hydraulic actuators are required. However, there is a problem in that a hydraulic pump and an electric motor must be provided for each hydraulic actuator, and the size of the device is rather increased.

An object of the present invention is to provide a hydraulic device in which a plurality of hydraulic actuators are directly connected to one hydraulic pump and the drive can be controlled.

[0005]

The present invention employs the following means in order to solve the above problems. That is, in a hydraulic device in which a plurality of hydraulic actuators are driven in a preset operation sequence by a hydraulic liquid supplied from one hydraulic pump, the hydraulic pumps are driven by an electric motor to rotate in forward and reverse directions. According to the pump that can rotate in both directions, both ports of each hydraulic actuator and both ports of the hydraulic pump are connected in parallel via a pipe line, and each hydraulic actuator is connected in the pipe line. An electromagnetic opening / closing valve is interposed and a control circuit is provided for controlling the hydraulic actuator to be driven by opening / closing each of the electromagnetic opening / closing valves and controlling the operating direction of the hydraulic actuator by forward / reverse rotation of the electric motor. That is a hydraulic device characterized in that.

A position sensor for detecting the displacement of one specific actuator among the plurality of hydraulic actuators is provided, and the control circuit further controls the electric motor based on a signal from the position sensor. You may.

Further, the hydraulic actuator is a hydraulic cylinder, and a hydraulic tank corresponding to the volume of the cylinder rod is provided, and the hydraulic tank and both ports of the hydraulic pump are connected via a pilot check valve. May be.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes a hydraulic pump which is rotatable in both directions. When the pump is rotated forward, hydraulic fluid is sucked from a first port 2 side and discharged to a second port 4 side. When the rotation is reversed, the hydraulic fluid is sucked in from the second port 4 side and discharged from the first port 2 side. The hydraulic pump 1 is connected so as to be driven to rotate by an electric motor 6 such as a servomotor.

A first pipe line 8 and a second pipe line 10 are connected to the first port 2 and the second port 4, respectively, and the second pipe line 10 has a plurality of hydraulic actuators, three in this embodiment. First to third hydraulic actuators 1 using the above hydraulic cylinders
The head side ports 15 to 17 of 2 to 14 are respectively branched and connected. The first to third hydraulic actuators 12 to 14 are not limited to hydraulic cylinders, and hydraulic motors can be used in the same manner.

Further, the first conduit 8 is connected to the rod side ports 18 to 20 of the first to third hydraulic actuators 12 to 14 via the first to third electromagnetic on-off valves 22 to 24, and the liquid The pressure pump 1 includes first to third hydraulic actuators 12 to 14
Are connected in parallel. First to third solenoid on-off valves 22 to
Reference numeral 24 denotes an open position 22a to 24a which communicates the first pipeline 8 when an excitation signal is input, and a closed position 2 which shuts off the first pipeline 8 by a spring biasing force when no excitation signal is input.
2b to 24b.

The first pipeline 8 is connected to the hydraulic tank 30 via a first pilot check valve 32, and the first pilot check valve 32 introduces the hydraulic pressure of the second pipeline 10 as a pilot pressure, When the hydraulic pressure in the second pipeline 10 rises, the valve is opened to connect the first pipeline 8 and the hydraulic tank 30 to each other.

Further, the second pipeline 10 is connected to the hydraulic tank 30 via a second pilot check valve 34,
The second pilot check valve 34 introduces the hydraulic pressure of the first pipeline 8 as pilot pressure, and opens when the hydraulic pressure of the first pipeline 8 rises, and the second pilot check valve 34 opens the second pipeline 10 and the hydraulic tank 30. Are connected to communicate with each other.

In this embodiment, one first hydraulic actuator 12 among the three first to third hydraulic actuators 12 to 14 is a specific actuator 12, and a position for detecting the displacement of the specific actuator 12 is determined. A sensor 36 is provided. The position sensor 36 is connected to a control circuit 38, which controls the first to third electromagnetic on-off valves 22-2.
4 is connected so that an excitation signal can be output.

Next, a case where the hydraulic device of this embodiment is applied to a pipe bending device will be described with reference to FIG. The pipe bending apparatus includes a bending die 42 formed according to the bending radius of the pipe 40, and the pipe 40 has an outer periphery of the bending die 42.
A groove 44 corresponding to the diameter of the groove is formed. The bending die 42 is rotatably supported together with a bending arm 46, and the bending arm 46 is mounted so as to be rotationally driven by the specific actuator 12. As shown in FIG. 1, the rotation angle of the bending arm 46 is detected by the position sensor 36 using an encoder and is output to the control circuit 38.

A clamping die 48 is slidably supported on the bending arm 46 so as to face the bending die 42.
Is driven by the second hydraulic actuator 13 so that the pipe 40 can be clamped by the bending die 42 and the clamping die 48. A wiper die 50 is arranged close to the bending die 42, and a pressure die 52 is slidably supported on a main body (not shown) so as to face the wiper die 50. The pressure die 52 is configured to be driven by the third hydraulic actuator 14 and applied to the pipe 40 so as to receive a reaction force during bending.

Next, regarding the operation of the hydraulic device of the present embodiment described above, the case where it is applied to a pipe bending apparatus will be taken as an example.
It will be described together with the bending control processing shown in FIG. 3 performed in the control circuit 38. First, the pipe 40 is supplied between the bending die 42 and the tightening die 48, and then the electric motor 6 is normally rotated to drive the hydraulic pump 1. Therefore, the hydraulic pump 1 sucks the hydraulic fluid from the first port 2 side and discharges it from the second port 4 side. Further, an excitation signal is output from the control circuit 38 to the second electromagnetic opening / closing valve 23 to switch the second electromagnetic opening / closing valve 23 to the open position 23a (step 100).

Therefore, from the rod side port 19 of the second hydraulic actuator 13 to the second electromagnetic on-off valve 23 and the first conduit 8
The working fluid is sucked into the first port 2 of the hydraulic pump 1 via the. Then, pressure fluid is supplied from the second port 4 to the second hydraulic actuator 13 via the second conduit 10 and the head-side port 16.

At this time, there is a difference in volume of the cylinder rod between the amount of hydraulic fluid discharged from the rod side port 19 and the amount of pressurized fluid supplied from the head side port 16. The first pilot check valve 32 is opened by the action of the pilot pressure from the second pipe 10 and the hydraulic fluid of the difference is supplemented from the hydraulic tank 30 via the first pipe 8.
When the first to third hydraulic actuators 12 to 14 are double rod hydraulic cylinders, the hydraulic tank 30 is not always necessary. In this way, the second hydraulic actuator 13 is driven, the fastening die 48 is slid toward the bending die 42, and the pipe 40 is moved by the bending die 42 and the fastening die 48.
Is pinched.

Next, an excitation signal is output to the third solenoid on-off valve 24 to switch to the open position 24a (step 11).
0). Thus, similarly to the above, the rod side port 20 of the third hydraulic actuator 14 and the third solenoid on-off valve 2
4. The liquid is sucked from the first port 2 of the hydraulic pump 1 via the first pipe 8, and is supplied to the head side port 17 via the second port 4 and the second pipe 10. Therefore, the third hydraulic actuator 14 is driven, the pressure die 52 is slid toward the pipe 40, and the pressure die 52 is applied to the pipe 40.

Next, an excitation signal is output to the first electromagnetic on-off valve 22 to switch to the open position 22a, and the rod side port 18, the first electromagnetic on-off valve 22, the first port 2 via the first pipe line 8. Then, the pressurized liquid is supplied through the second port 4, the second conduit 10, and the head side port 15 (step 120).

Therefore, the specific actuator 12 is driven to rotate the bending die 42 together with the bending arm 46. The pipe 40 is bent so as to be wound around the groove 44 of the bending die 42. The rotation angle of the bending die 42 is detected by the position sensor 36, and when the rotation angle reaches a preset angle, it is determined that the bending is completed (step 13).
0). At this time, by controlling the number of revolutions of the electric motor 6, the operating speed of the specific actuator 12 can also be controlled.

Next, the output of the excitation signal to the first electromagnetic on-off valve 22 is stopped and switched to the closed position 22b, and the excitation signals are continuously output to the second and third electromagnetic on-off valves 23 and 24 to open. The positions are set to 23a and 24a, and the electric motor 6 is rotated in the reverse direction (step 140). Therefore, the head side ports 16, 1 of the second and third hydraulic actuators 13, 14 are
7, the hydraulic fluid is sucked into the hydraulic pump 1 from the second port 4 via the second pipeline 10, the first port 2, the first pipeline 8, the second and third electromagnetic on-off valves 23 and 24, and the rod. Side port 19,
20 through the second and third hydraulic actuators 13, 14
Liquid is supplied to. As a result, the clamping die 48 and the pressure die 52 are slid and separated from the pipe 40.

Then, after retracting the clamping die 48 and the pressure die 52, the output of the excitation signal to the second and third electromagnetic on-off valves 23 and 24 is stopped to switch to the closed positions 23b and 24b.
An excitation signal is output to the first electromagnetic on-off valve 22, and the working fluid is sucked through the head-side port 15, the second pipe line 10, and the second port 4 of the specific actuator 12, and the first port 2, the first pipe The pressurized liquid is supplied to the specific actuator 12 through the passage 8, the first electromagnetic opening / closing valve 22, and the rod side port 18 (step 150).

Accordingly, the specific actuator 12 is driven, the bending arm 46 is returned to the original position, and when the position sensor 36 detects the return to the original position (step 160), the drive of the electric motor 6 is stopped. As well as
The output of the excitation signal to the first solenoid on-off valve 22 is stopped,
The driving of all the actuators 12 to 14 is stopped (step 170).

As described above, the hydraulic device of this embodiment has the first
~ The first to third hydraulic actuators 12 to 14 to be operated are determined by switching the third electromagnetic on-off valves 22 to 24, and the operating directions of the first to third hydraulic actuators 12 to 14 are:
It is controlled by the rotation direction of the electric motor 6.

Therefore, simple first to third electromagnetic on-off valves 22 to 24 may be used without providing large electromagnetic valves such as a switching valve to each of the first to third hydraulic actuators 12 to 14. The pressure tank 30 may have a small capacity, and the device can be downsized. Moreover, by providing the position sensor 36 on the specific actuator 12, the operation of the specific actuator 12 can be controlled without using a large and precise valve such as a hydraulic servo valve.

As described above, the present invention is not limited to such an embodiment, and can be implemented in various modes without departing from the gist of the present invention.

[0028]

As described in detail above, in the hydraulic apparatus of the present invention, a plurality of hydraulic actuators directly connected to one hydraulic pump can be driven by the opening / closing control of the electromagnetic opening / closing valve and the drive control of the electric motor. Therefore, the device can be downsized. Further, by providing a position sensor on the specific actuator, the operation of the specific actuator can be controlled with a simple configuration without using a large and precise valve such as a hydraulic servo valve.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a hydraulic device as one embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of a pipe bending device to which the hydraulic device of this embodiment is applied.

FIG. 3 is a flowchart showing an example of bending control processing performed by the control circuit of the present embodiment.

[Explanation of symbols]

 1 ... Hydraulic pump 6 ... Electric motor 12, 13, 14 ... Hydraulic actuator 22, 23, 24 ... Electromagnetic on-off valve 30 ... Hydraulic tank 36 ... Position sensor 38 ... Control circuit

Claims (3)

[Claims] 1. A hydraulic device for driving a plurality of hydraulic actuators by a hydraulic fluid supplied from a single hydraulic pump in a preset operation sequence, wherein the hydraulic pump is driven by an electric motor, A pump capable of rotating in both directions in response to reverse rotation, connecting both ports of each hydraulic actuator and both ports of the hydraulic pump in parallel via a pipe line, and connecting each of the hydraulic actuators with the pipe. A control circuit in which an electromagnetic opening / closing valve is interposed in the path to control the hydraulic actuators to be driven by opening / closing each of the electromagnetic opening / closing valves, and to control the operating direction of the hydraulic actuators by forward / reverse rotation of the electric motor. A hydraulic device comprising: 2. One of the plurality of hydraulic actuators
The hydraulic device according to claim 1, further comprising a position sensor that detects a displacement of a specific actuator of the table, wherein the control circuit further controls the electric motor based on a signal from the position sensor. 3. The hydraulic actuator is a hydraulic cylinder, and a hydraulic tank corresponding to the volume of the cylinder rod is provided.
3. The hydraulic device according to claim 1, wherein the hydraulic tank and both ports of the hydraulic pump are connected via a pilot check valve.