JPH0477921B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an actuator control device that controls an actuator using fluid pressure such as oil pressure or pneumatic pressure, and particularly relates to an actuator control device that controls an actuator using fluid pressure such as oil pressure or air pressure. The present invention relates to an actuator control device that can accurately and quickly control the force applied to the load of the actuator.

2. Description of the Related Art A conventional actuator control device will be described with reference to FIG.

Pressure source 51 and pressure chamber 53 of actuator 52
are connected by a main line 54. main line 5
A spool valve 55 is disposed at 4. Spool valve 55
A pressure detector 56 detects the pressure of the main line 54a between the pressure chamber 53 of the actuator 52 and the pressure chamber 53 of the actuator 52.
will be established. The opening degree of the spool valve 55 is controlled by a controller 57. The controller 57 receives a detected pressure signal 58 from the pressure detector 56 and a target pressure signal 59.
is input, and a control signal 60 is supplied to the spool valve 55 based on the comparison value with both signals to control the opening degree. That is, the pressure in the main line 54a is controlled by pressure feedback control via the main line 54a. Based on such pressure control, the force applied to the load on the actuator 52 is controlled.

Problems to be Solved by the Present Invention In this case, there is a problem that the force applied to the load of the actuator 52 cannot be controlled quickly and accurately. This is because the responsiveness and controllability of the pressure supplied to the pressure chamber 53 of the actuator 52 is poor. That is, the pressure is controlled as a result of controlling the opening degree of the spool valve 55 to control the flow rate, and since the relationship between the opening degree and pressure is non-linear, the target pressure signal 59 and the pressure detector 56 detect the pressure. Detection pressure signal 5
This is because the opening degree of the spool valve 55 must be gradually controlled while comparing the opening degree of the spool valve 55. This results in poor responsiveness and complicated control. Control using linear approximation not only allows control only under limited conditions but also becomes inaccurate.

Therefore, the technical problem of the present invention is to improve the responsiveness and control of the pressure supplied to the pressure chamber of the actuator, so that the actuation amount of the actuator can be controlled quickly and accurately.

Means for Solving the Problems The technical means of the present invention aimed at solving the above technical problems is to connect the secondary side of the pressure reducing valve to the pressure chamber of the actuator and adjust the set pressure of the pressure reducing valve. The actuator's piston rod is connected to the piston rod of the actuator via a connecting member to control the force applied to the actuator's load.

Effect The operation of the above technical means is as follows.

The pressure reducing valve has a pressure self-adjustment function, and there is a linear relationship between the set pressure and the amount of adjustment by the adjustment means. Further, since there is a linear relationship between the set pressure of the pressure reducing valve and the force of the actuator against the load, there is a linear relationship between the adjustment amount of the adjusting means of the pressure reducing valve and the force of the actuator against the load. Since the means for adjusting the set pressure of the pressure reducing valve and the piston rod of the actuator are connected by the connecting member, the piston rod and the connecting member are displaced in response to the load acting on the piston rod, thereby displacing the adjusting means. The set pressure of the pressure reducing valve, ie, the pressure introduced into the pressure chamber of the actuator, is adjusted by the displacement of this adjusting means, and the force applied to the load of the actuator is controlled. Therefore, based on the load acting on the piston rod, the adjusting means is caused to be displaced all at once by the connecting means, so that the set pressure of the pressure reducing valve is quickly set, and the setting is easy and accurate, and the force against the load of the actuator is quickly applied. and accurately controlled.

Effects of the Invention As described above, according to the present invention, the force applied to the load of the actuator can be controlled quickly and accurately, so it can also be used in fields that require high-performance control such as actuators of robots. can.

Furthermore, since the adjusting means is operated via the connecting member, electrical parts such as a controller are not required, and the device can be manufactured at low cost and can be used in explosion-proof areas.

Embodiment An embodiment illustrating a specific example of the above technical means will be described (see FIG. 1).

A pressure source 1 and a pressure chamber 3 of an actuator 2 are connected via a main line 4 and a pressure reducing valve 5. Actuator 2 and pressure reducing valve 5 are directly connected.

The casing of the pressure reducing valve 5 consists of a spring case 7 housing a pressure setting spring 6, a valve case 9 in which a pilot valve 8 is arranged, and a main body 11 in which a main valve 10 is arranged.

A diaphragm 12 is sandwiched between a spring case 7 and a valve case 9. A diaphragm disk 13 is brought into contact with the upper surface of the diaphragm 12, and a relief valve seat 14 is screwed to the diaphragm disk 13 to connect and fix the diaphragm 12, diaphragm disk 13, and relief valve seat 14.

The lower end of the pressure setting spring 6 housed in the spring case 7 abuts against the upper surface of the diaphragm 12 via the diaphragm disk 13. The upper end of the pressure setting spring 6 abuts against the lower surface of the spring seat 15. An adjustment screw 17 as an adjustment means is arranged on the upper surface of the spring seat 15 via a hard ball 16. The spring case 7 that comes into contact with the adjustment screw 17 is not provided with a screw, but is merely guided. The upper space of the diaphragm 12 is connected to the outside air through a passage 18, and the lower space is connected to an outlet passage 20 described below through a passage 19.

The main body 11 is formed with an inlet passage 21 and an outlet passage 20. The inlet passage 21 and the outlet passage 20 are connected to the main valve seat 2
It is connected through the main valve port 23 provided in 2. Main valve 1
0 is located below the main valve port 23 and its upper end is connected to the piston 24. The piston 24 slides within a cylinder 25 attached to the inner periphery of the main body 11. Two annular grooves are provided around the outer circumference of the piston 24 to accommodate piston rings, and a passage 26 connecting the upper and lower surfaces is opened.

The pilot valve 8 is connected to the passage 2 which communicates with the inlet passage 21.
7 and a passage 28 communicating with the space above the piston 24, a pilot valve element 29 slides within a pilot valve seat 30 to open and close the pilot valve port from below. The pilot valve body 29 is urged upward by a spring 31 from below. The upper end portion of the pilot valve body 29 also serves as a relief valve body that approaches and separates from the relief valve seat 14 to open and close the relief valve port.

The actuator 2 includes a cylinder 32 and a piston 33 disposed in the cylinder 32 so as to be able to slide back and forth.
, a piston rod 34 having one end fixed to the piston 33 and the other end extending outside the cylinder 32 , a spring 35 disposed inside the cylinder 32 to return the piston 33 , and a space between the outer periphery of the piston 33 and the piston rod 34 and the cylinder 32 . It consists of sealing means 36, 37 arranged in the cylinder 32, a passage 38 opened in the cylinder 32 and communicating with the outside air, and a passage 39 connecting the outlet passage 20 and the pressure chamber 3. cylinder 3
A flange is formed at the upper end of 2 and connected to a flange at the lower end of the main body 11 of the pressure reducing valve 5 .

Attach the disc 40 to the adjustment screw 17 and the piston rod 3.
Attach the disk 41 to 4. A screw is provided on the disc 40 so that the adjusting screw 17 can move forward and backward. The disk 41 is fixed to the piston rod 34. Disc 4
0 and 41 are connected and fixed with a connecting rod 42. Connecting rod 4
2 is drawn only on the right side of the drawing, but it is also provided on the left side.

Depending on the load acting on the piston rod 34,
Piston rod 34, disk 40, connecting rod 4
2. The adjustment screw 17 connected via the disc 41 is displaced up and down. This displacement of the adjusting screw 17 causes the spring seat 15 to move up and down, and the elastic force of the pressure setting spring 6 is adjusted, thereby adjusting the elastic force acting on the diaphragm 12. When the diaphragm 12 is displaced downward, the pilot valve body 29 is pushed down, and the fluid in the inlet passage 21 is introduced into the space above the piston rod 24 through the passages 27 and 28.
The main valve 10 is pushed down by the piston 24, the main valve port 23 is opened, and the fluid in the inlet passage 21 is transferred to the outlet passage 2.
Flows to 0. Since the outlet passage 20 is connected to the space below the diaphragm 12 through the passage 19, the diaphragm 12 is pushed back upward by the fluid flowing into the outlet passage 20, and the pilot valve is opened at a position balanced with the elastic force of the pressure setting spring 6. The body 29 is pushed up by the spring 31 to close the passage 27, and the main body 10 also closes the main valve port 23. Conversely, when the diaphragm 12 is displaced upward, the upper end of the pilot valve body 29, which also serves as a relief valve body, touches the relief valve seat 14.
The relief valve port is opened, and the fluid in the outlet passage 20 is discharged to the outside air through the passage 19, the relief valve opening, and the passage 18, and the pressure in the space below the diaphragm 12 is reduced.
That is, the pressure in the outlet passage 20 decreases, the diaphragm 12 is pushed back downward, and the relief valve port is closed at a position where the elastic force of the pressure setting spring 6 and the pressure in the outlet passage 20 are balanced. In this way, the pressure in the outlet passage 20 of the pressure reducing valve 5 is regulated. Since the outlet passage 20 is connected to the pressure chamber 3 of the actuator 2, the pressure of the outlet passage 20 is introduced into the pressure chamber 3 of the actuator 2, and the pressure of the outlet passage 20 is introduced into the pressure chamber 3 of the actuator 2.
The force on the load acting on the piston rod 34 is controlled.

Further, when changing the output position of the piston rod 34, it is done by rotating the adjusting screw 17 left and right.

In this embodiment, since the pressure reducing valve 5 and the actuator 2 are directly connected, there is no time delay in pressure control of the pressure chamber 3, and the responsiveness of the actuator 2 is improved.

Although a pilot type pressure reducing valve is used as the pressure reducing valve 5, a direct acting type may also be used.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an actuator control device according to an embodiment of the present invention, and FIG. 2 is a mechanical diagram of a conventional actuator control device. 1: Pressure source, 2: Actuator, 3: Pressure chamber, 5: Pressure reducing valve, 6: Pressure setting spring, 12: Diaphragm, 17: Adjustment screw, 20: Outlet passage, 2
1: Entrance passage, 42: Connecting rod.

Claims (1)

[Claims] 1 The secondary side of the pressure reducing valve is connected to the pressure chamber of the actuator, and the means for adjusting the set pressure of the pressure reducing valve and the piston rod of the actuator are connected via a connecting member to control the force applied to the load on the actuator. Actuator control device.