JPS6213555B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a pneumatic actuator that controls the speed or position of a pneumatic actuator operated by pneumatic pressure, such as a pneumatic cylinder or a pneumatic motor. Regarding a control device.

"Prior Art" Conventionally, for example, in order to control the speed of a pneumatic cylinder in multiple stages, a directional control valve C for supply/discharge switching is installed between a pneumatic cylinder A and a compressed air supply source B, as shown in FIG. At the same time, on the exhaust side of this directional control valve C, a throttle valve D for multi-stage adjustment and a directional control valve E were connected in parallel for the number of stages.

``Problem to be solved by the invention'' Therefore, the number of throttle valves D and directional control valves E is required depending on the stage of adjustment, which requires a large amount of installation space and assembly man-hours, and also has the drawback that equipment costs are high. It was hot. Furthermore, since the stepwise control is performed using a plurality of throttle valves D and the same number of directional control valves E, not only is control adjustment very troublesome, but delicate continuous control is not possible. If D or even one directional control valve E malfunctions, there are problems such as the overall speed control being deviated even if the other valves are normal.

First, an object of the present invention is to perform speed control or position control using one directional control valve and one proportional solenoid valve, without using a plurality of throttle valves and directional control valves as in the past. The second objective is to make it possible to perform both multi-step and stepless continuous control.The second objective is to facilitate the control adjustment.The third objective is to enable delicate continuous control to be performed easily. Fourth, ensure operation.

"Means for solving the problem" In order to achieve such an object, in the present invention, a directional control valve C for controlling the direction of operation is connected to a port of a pneumatic actuator such as a pneumatic cylinder, and A two-way flow rate control type proportional solenoid valve F is connected to the exhaust port or air supply port of the directional control valve C. The proportional solenoid valve F
is a valve seat 10 provided between an inlet 3 and an outport 4 in the valve body 1, and a coil 1.
3, and a plunger 14 slidably provided between the valve seat 10 and the fixed iron core 12. The plunger 14 is provided with a spring receiving recess 19 that is long in the axial direction, and a spring adjustment rod 23 that can be moved forward and backward in the axial direction is mounted through the fixed core 12 with a screw. Between this spring adjustment rod 23 and the blind end of the spring receiving recess 19, two strong and weak coil springs 20 and 21 are arranged in series in the spring receiving recess 19, and the spring force causes the plunger 14 to move. The tip of the valve is pressed against the valve seat 10.

"Function" Therefore, in one two-way flow rate control type proportional solenoid valve, the gap between the valve seat 10 and the plunger 14 is adjusted by the current supplied to the coil 13, and the gap between the valve seat 10 and the plunger 14 is adjusted from the inlet 3 to the outport. By changing the flow rate flowing to 4 in multiple steps or continuously, the operating speed or operating position of a pneumatic actuator such as a pneumatic cylinder can be adjusted continuously in multiple steps or steplessly. Since the plunger 14 is biased toward the valve seat 10 by two strong and weak coil springs 20 and 21 arranged in series within the receiving recess 19, the stronger coil spring 20 is used mainly for return and the weaker coil spring 20 is used for the return. The other coil spring 21 presses against the valve seat 10. Therefore, the gap between the plunger 14 and the valve seat 10 can be finely adjusted. The spring force of these coil springs 20, 21 is controlled by the spring adjustment rod 23.
It can be adjusted by turning the coil 13.
The relationship between the current supplied to the gap and the flow rate determined by the gap can be finely adjusted manually.

"Example" Examples of the present invention will be described below.

2 and 3 are pneumatic circuit diagrams of a first embodiment and a second embodiment of the present invention, respectively. first,
The two-way flow rate control type proportional solenoid valve F used in both of these embodiments will be explained. It has a single-piece structure in which a solenoid assembly 2 is installed on a valve body 1.

The valve body 1 has an inlet 3 and an outport 4 on opposite sides thereof, and a valve seat 6 is fitted into an inner recess 5 communicating with these ports.
The upper end protrusion 10 of this valve seat body 6 protrudes into an outer recess 7 which is a valve chamber of the valve body 1. On the valve seat 6,
A vertical hole 8 is bored, and the upper end of the vertical hole 8 serves as a valve port 9 that opens at the center of the upper surface of the protrusion 10 .

On the other hand, the electromagnet assembly 2 has a fixed core 12 fitted and fixed to the upper end of a guide pipe 11 made of a non-magnetic material, a coil 13 wound around the outside of the guide pipe 11 and the fixed core 12, and a plunger 14. It is slidably fitted into the guide pipe 11 between the fixed iron core 12 and the valve seat 6. This electromagnet assembly 2 has a lower end portion of its guide pipe 11 fixed to the valve body 1 so that the guide pipe 11 communicates with the outer recess 7 of the valve body 1.

The plunger 14 has a seal member 16 made of an elastic material such as rubber fitted into a recess 15 on its lower surface. This sealing member 16 is prevented from being pulled out from the recess 15 by a pin 17 passing through it. Further, the plunger 14 has a vertical groove 18 forming a fluid passage on its outer circumferential surface, and a vertically elongated spring receiving recess 19 on its upper surface. Inside this spring receiving recess 19, there are two strong and weak coil springs 2.
0 and 21 are arranged vertically in series with a spring receiver 22 interposed between them. The upper strong coil spring 20 is pressed down from above by the lower end flange 24 of the spring adjustment rod 23 that vertically passes through the fixed iron core 12, and the lower weak coil spring 21 is held down by the upper coil spring 20 and the spring. It is pressed against the blind end of the spring receiving recess 19 via the receiving body 22. Therefore, the plunger 14 is urged downward, and the seal member 16 at its lower end is pressed against the valve seat 1.
Press it to 0.

The spring adjustment rod 23 has a male threaded portion 2 at its upper end.
5 is screwed into a screw hole 26 of the fixed core 12, and can be moved up and down relative to the fixed core 12 by turning it from the outside with a screwdriver or the like.

A thin annular plate 28 made of non-magnetic material is attached to the lower surface of the fixed iron core 12, and a lock nut 2 is attached to the male threaded portion 25 of the spring adjustment rod 23 to lock it.
9 are screwed together. Furthermore, a lock nut 2 is attached to the male threaded portion 30 that protrudes from the upper end of the fixed core 12.
9 and a cap 32 that covers the upper end of the screw adjustment rod 23 are screwed together.

In such a proportional solenoid valve F, the coil 13
In the normal state in which the coil spring 20 is demagnetized, the strong coil spring 20 is almost fully expanded and the weak coil spring 21 is compressed, as shown. Therefore, the plunger 14 is normally urged toward the valve seat 10 mainly by the weak spring action of the coil spring 21, and presses the seal member 16 against the valve seat 10 to close the valve port 9. At this time, the weak coil spring 21 is compressed, so even if the sealing member 16 is worn and the entire proportional solenoid valve F is subjected to impact, the valve port 9 can be kept properly closed.

When a current is applied to the coil 13, the plunger 14 is attracted toward the fixed iron core 12 by an attractive force corresponding to the current. At the initial stage of suction, plunger 1
4 rises while compressing the weak coil spring 13, and after the coil spring 13 is compressed to the limit, it rises while compressing the strong coil spring 20, and stops when the attractive force is balanced with the coil spring 20.

Therefore, by changing the current flowing through the coil 13, the gap between the plunger 14 and the valve seat 6 can be adjusted, and the flow rate from the inlet 3 to the outport 4 can be adjusted. In this case, since the plunger 14 can balance the suction force with the spring force of the weak coil spring 21 until the strong coil spring 20 is compressed, delicate flow rate adjustment is possible. It is also possible to manually adjust the spring force of the coil springs 20, 21 by turning the spring adjustment rod 23.

Now, in the first embodiment of the present invention shown in FIG. 2, a directional control valve C for supply/exhaust switching is connected between a pneumatic cylinder A and a compressed air supply source B, and the exhaust side The proportional solenoid valve F described above is connected to. Then, the current supplied to the coil 13 of the proportional solenoid valve F is continuously varied in multiple stages or steplessly using a function generator or the like.

Therefore, since the opening degree of the proportional solenoid valve F is adjusted as described above, the amount of compressed air discharged from the pneumatic cylinder A is adjusted accordingly, regardless of the sliding movement of the piston in any direction. The speed can be automatically controlled continuously in multiple stages or steplessly. Further, by attaching a sensor to the pneumatic cylinder A to detect the position of the piston, and controlling the coil 13 of the proportional solenoid valve F based on the output of the sensor, the position of the piston can be controlled in multiple stages.

In the second embodiment shown in FIG. 3, a proportional solenoid valve F is connected between the air supply side of the directional control valve C and the compressed air supply source B, and the flow rate of compressed air supplied to the pneumatic cylinder A is proportionally adjusted. Control is performed in the same manner as above using electromagnetic valve F.

"Effects of the Invention" As is clear from the above description, the control device for a pneumatic actuator of the present invention has the following effects.

One directional control valve and one two-way flow rate control type proportional solenoid valve are used, and in the proportional solenoid valve, the gap between the valve seat and the plunger is adjusted by the current supplied to the coil. By changing the flow rate from the import to the out port in multiple stages or continuously, it is possible to control the speed or position of pneumatic actuators such as pneumatic cylinders in multiple stages or continuously, making the control much easier than before. It is easy to install, requires less space for installing the valve, and can simplify piping.

In a proportional solenoid valve, the plunger is biased toward the valve seat by two strong and weak coil springs arranged in series, with the stronger coil spring mainly returning the plunger and the weaker coil spring pushing it against the valve seat. Therefore, the gap between the plunger and the valve seat can be finely adjusted, and delicate speed control or position control is therefore possible.

Since the spring force of the above two strong and weak coil springs can be adjusted by turning the spring adjustment rod, the relationship between the current supplied to the coil and the flow rate determined by the above gap can be finely adjusted manually. Speed control or position control can also be fine-tuned manually.

[Brief explanation of the drawing]

Figure 1 is a pneumatic circuit diagram of a conventional example, Figures 2 and 3
The figures are pneumatic circuit diagrams of a first embodiment and a second embodiment of the present invention, respectively, and FIG. 4 is a sectional view of a proportional solenoid valve used therein. C... Directional control valve, F... Proportional solenoid valve, 1... Valve body, 3... Import, 4... Out port, 10...
Valve seat, 12...fixed iron core, 13...coil, 14...plunger, 20...strong coil spring, 21...weak coil spring, 23...spring adjustment rod.

Claims (1)

[Claims] 1 A directional control valve C is installed at the port of a pneumatic actuator such as a pneumatic cylinder to control its operating direction.
At the same time, one two-way flow rate control type proportional solenoid valve F is connected to the exhaust port or air supply port of the directional control valve C, and the proportional solenoid valve F is connected to the import 3 in the valve body 1. and outport 4
a fixed iron core 12 magnetized by a coil 13, and a valve seat 10 provided between the valve seats 10 and
and a plunger 14 that is slidably provided between the fixed core 12, and the plunger 14 is provided with a spring receiving recess 19 that is long in the axial direction. Spring adjustment rod 23 that can be moved forward and backward in the axial direction
The spring adjustment rod 23 and the blind end of the spring receiving recess 19 are fitted with two strong and weak coil springs 20 and 21 in the spring receiving recess 19.
A control device for a pneumatic actuator, characterized in that the plunger 14 is arranged in series, and its spring force presses the tip of the plunger 14 against the valve seat 10.