JPH0434242Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a fluid pressure circuit for transporting a heavy object using an actuator used in a pneumatic circuit.

[Conventional technology]

When transporting a heavy object from a predetermined stroke of a cylinder that is an actuator, the stroke (no-load state) up to the heavy object should be driven at high speed, and after reaching the heavy object, it should be driven at a certain predetermined low speed. is important from the viewpoint of work efficiency, and a pneumatic circuit as shown in FIG. 6 has been conventionally used.

To explain FIG. 6, the piston 32 of the cylinder 31 moves to the right in the figure, and the solenoid valves 36 to 31 move through the solenoid valve 35 as shown in the figure to the limit switch 34 disposed just before the heavy object 33. Since the air in the rod side chamber 37 is directly exhausted, the rod can be driven at high speed. Next, the piston rod 3 of the cylinder 31
When the dog 39 attached to the tip of the valve 8 hits the limit switch 34, the solenoid valve 35 is switched, and the flow rate is controlled by the speed controller 40 for low-speed driving (meter-out control).

[Problem that the invention attempts to solve]

According to the conventional example above, a large number of devices and pneumatic piping,
The difficulty was that the electrical wiring etc. became complicated and the cost increased significantly.

[Means for solving problems]

Here, this invention is a fluid pressure circuit in which a piston is slidably fitted into a cylinder of an actuator, and fluid pressure is switched and supplied to each of two chambers partitioned by the piston. , supplying fluid to each chamber;
A flow control valve with a rapid exhaust valve having a rapid exhaust function and a flow rate control function is installed in the passage communicating with the chamber on the rod side among the exhaust passages, and the cylinder internal pressure is set by the rapid exhaust valve section. By proposing a fluid pressure circuit that rapidly exhausts the cylinder when the pressure is higher than the set pressure, and drives the cylinder at a high speed, and when the cylinder pressure is lower than the set pressure, the flow control drives the cylinder at a predetermined low speed. It is integrated into a single device, and instead of being controlled by an external signal from a limit switch as in the conventional case, it detects changes in the air pressure inside the cylinder and switches the throttle to control the speed. This makes it possible to simplify the process, and also eliminates the need for electrical wiring, allowing for significant cost reductions.

[Effect]

Next, this invention will be explained with reference to the drawings.

1 and 2 are a fluid pressure circuit diagram and its characteristic curve diagram. In the figure, 1 is an actuator, 2 is a cylinder of the actuator 1, and 3 is a piston that partitions the inside of this cylinder 2 into two chambers 4 and 5. A flow control valve 8 with a quick exhaust valve is arranged in a passage 7 that communicates a directional control valve (not shown) with a chamber 4 on the rod 6 side of the piston 3 that is slidably fitted in the cylinder 2. A speed controller 10 is disposed within a passage 9 which communicates the head side chamber 5 with the directional control valve.

The flow control valve 8 with rapid exhaust valve has an actual structure as shown in FIG. 3, for example. That is, the main body 11 is provided with an inlet/outlet port 12 that communicates with the chamber 4 on the rod 6 side, and a supply port 13 that communicates with the directional switching valve.
13, inside the main body 11, a flow rate control valve 14 consisting of a check valve and a throttle part such as a needle valve, and a pressure regulating valve 15 having a rapid exhaust function are arranged in parallel. Of these,
The flow rate control valve 14 has a valve body 17 seated on a valve seat 16.
and a valve culm 19 that is loosely inserted into a center hole 18 formed in this valve body 17, and this valve culm 19 extends and protrudes outside the main body 11, and is connected to a screw hole 20 formed in this main body 11. Since the valve culm 19 is connected by screwing, the tip of a screwdriver or the like is inserted into the groove 21 formed on the end face of the valve culm 19 and rotated to move the valve culm 19 forward or backward.
As a result, the gap 2 between the valve body 17 and the valve seat 16
2 can be changed and adjusted. That is, this flow control valve 14 is closed as a check valve when it goes from port 13 to port 12, and performs a throttling action as a needle valve when it goes from port 12 to port 13.

The pressure regulating valve 15 is provided in a passage 24 that is formed separately from the passage 23 that passes through the flow rate control valve 14. It is composed of an integrally formed piston-shaped partition wall 26' and a pressure regulating spring 28 compressed between the piston-shaped partition wall 26' and the pressure regulating member 27, so that the pressure on the port 12 side is When the pressure exceeds the value set by the pressure regulating spring 28, the valve body 26
The valve seat 25 is formed so as to be separated from the valve seat 25. In this pressure regulating valve 15 as well, by inserting the tip of a screwdriver or the like into a groove 28' cut into the end face of the pressure regulating member 27 and rotating it, the pressure regulating member 27 screwed into the main body 11 is moved forward and backward. Pressure adjustment spring 2
The set pressure can be changed by adjusting the force of 8.

Flow control valve 8 with rapid exhaust valve configured as above
is arranged in the passage 7 on the rod side, and on the other hand, a speed controller 10 (which is a normal type speed control valve consisting of a combination of a throttle valve and a check valve in parallel) is arranged in the passage 9 on the head side. Actuator 1
When a fluid pressure circuit is formed to each chamber 4 and 5 (Fig. 1), the pressure in chamber 4 is P _R , and the pressure in chamber 5 is
Figure 2 shows the transition of pressures P _{R and} P _H with respect to the movement (stroke) a of the piston, with the pressure inside P _H as the vertical axis and time on the horizontal axis. In the unloaded state until the rod 6 reaches the heavy object 14, the pressure on the port 12 side that acts above the valve body 26 of the pressure regulating valve 15 is high, so the valve body 26 resists the force of the pressure regulating spring 28. Since it is separated from the valve seat 25, the pressure P _R in the chamber 4 of the cylinder 2 is rapidly exhausted, and the piston 3 rapidly moves from b to c, but when the rod 6 hits the heavy object 14, the cylinder 2 As the pressure P _R in the chamber 4 further decreases, the pressure regulating valve 15 is moved forward by the force of the pressure regulating spring 28, and the valve body 26 is pressed against the valve seat 25, and the flow of fluid is cut off. One aisle 2
Flow is carried out through the gap between the valve body 17 and the valve seat 16 of the flow control valve 14, which is narrowed to a predetermined opening degree, and is driven at a low speed. is added, piston 3 rapidly
can be decelerated from c to d.

The circuit shown in FIG. 4 is used for the same purpose as that shown in FIG. The speed controller 29 is arranged in the passage 7 in series with the flow control valve 8 with a rapid exhaust valve. In this way, the speed control during no load is performed by the speed controller 29, and the load 3
After 0 is applied to the rod 6, the speed control is performed by the flow control valve 14 of the flow control valve 8 with a rapid exhaust valve, and the pressure in the chamber 4 is P _R and the pressure in the chamber 5 is P _H Figure 5 shows the fluctuations of each pressure P _R and P _H with respect to the movement a of the piston 3 when

[Effect of idea]

According to this idea, various functions are consolidated into a single device, and instead of being controlled by an external signal from a limit switch as in the conventional case, the change in air pressure inside the cylinder is detected and the speed is controlled by switching the throttle. This makes piping simple with a single device and eliminates the need for electrical wiring, making it possible to significantly reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a fluid pressure circuit diagram of this invention, Fig. 2 is a comparative characteristic curve thereof, Fig. 3 is a sectional view of a specific example of a flow control valve with a rapid exhaust valve used in the circuit of this invention, 4 and 5 are other fluid pressure circuit diagrams of this invention and comparative characteristic curve diagrams thereof, and FIG. 6 is an example of a conventional pneumatic circuit. In the figure, 1... actuator, 2...
...Cylinder, 3...Piston, 4, 5...Chamber, 6
... Rod, 7 ... Passage, 8 ... Flow control valve with rapid exhaust valve, 9 ... Passage, 10 ... Speed controller, 11 ... Main body, 12 ... Inlet/outlet port,
13... Supply port, 14... Flow rate control valve, 15
...It is a pressure regulating valve.

Claims (1)

[Scope of utility model registration request] In a fluid pressure circuit in which a piston is slidably fitted into the cylinder of an actuator and fluid pressure is switched and supplied to each of two chambers partitioned by the piston, Among the passages for supplying and discharging fluid,
A flow control valve with a rapid exhaust valve having a rapid exhaust function and a flow rate control function is installed in the passage communicating with the chamber on the rod side, and when the cylinder internal pressure is higher than the pressure set by the rapid exhaust valve part, A fluid pressure circuit that performs rapid exhaust to drive the cylinder at high speed, and when the cylinder internal pressure is lower than the set pressure, controls the flow rate to drive the cylinder at a predetermined low speed.