JPH0224962Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control valve suitable for use in controlling the speed of an actuator such as a cylinder.

[Conventional technology]

When a cylinder is driven by fluid pressure, it must be started slowly to prevent the danger of sudden ejection, and stopped slowly to provide a buffer when returning. There are many cases where this is not the case.

Slow starting and slow stopping of such cylinders can be performed by controlling the flow rate of pressure fluid supplied to and discharged from the cylinder during starting and stopping, but it is possible to perform slow starting and slow stopping of the cylinder by controlling the flow rate of pressure fluid supplied to and discharged from the cylinder during starting and stopping. By simply switching the flow path on and off, it is not possible to control the flow rate of the pressure fluid at startup and shutdown, and therefore it is not possible to slowly start and stop the cylinder.

There is a method to control the flow rate by connecting a speed controller between the switching valve and the cylinder, but in order to control the flow rate both at startup and stop, it is necessary to use a four-way valve, as shown in Figure 5. A plurality of speed controllers 52, 53 having different opening areas and a plurality of on/off valves 54 are provided between the cylinder 50 and the cylinder 51.
-56, and these four-way valves 50 and on/off valves 54-56 must be configured to be switched according to the time chart shown in FIG.
The circuit configuration and piping become complicated. Moreover, since the cross-sectional area of the flow path changes rapidly due to switching, smooth speed control cannot be performed.

[Problems to be solved by the invention] The problem of the invention is to switch the main valve body using pilot fluid pressure and the biasing force of a spring without using the speed controller mentioned above, which tends to have complicated circuit configurations and piping. By using an electromagnetic pilot type control valve, the main valve body is slowly driven and returned by controlling the supply flow rate and discharge flow rate of pilot fluid to the pilot chamber, thereby reducing the pressure on the actuator. The purpose of the present invention is to control the supply flow rate and discharge flow rate of fluid so that slow start and slow stop of an actuator can be realized by smooth speed control.

[Means for solving problems]

In order to solve the above problems, in this invention,
A main valve element that controls the opening amount of the flow path between the ports is arranged in the main valve part equipped with a pressure fluid supply port and an output port, and a pilot through hole is provided at the end of the main valve element to connect the supply port to the main valve part. A pilot chamber is formed into which pilot fluid pressure for driving the main valve body is introduced from the main valve body through the pilot valve part, and a set spring is compressed at the other end of the main valve body, and the pilot valve part is provided with a set spring.
A valve chamber into which a supply hole, an output hole, and a discharge hole are opened is provided, and a pilot valve is disposed in the valve chamber to selectively communicate the supply hole and the discharge hole with the output hole. The passage hole and the supply side pilot passage hole are communicated via a supply control needle whose opening amount can be adjusted, and the output passage hole and the pilot chamber are directly communicated, and the discharge passage hole and the pilot valve part are opened to the outside. A technical measure has been taken in which the pilot valve is connected to a discharge port via a discharge control needle whose opening amount can be adjusted, and an electromagnetic drive mechanism is attached to the pilot valve.

[Effect]

When pilot fluid is supplied to the pilot chamber by switching the pilot valve, the main valve body is driven against the biasing force of the set spring, bringing the supply port into electrical continuity with the output port. Since the flow rate is controlled by the supply control needle, the main valve body moves slowly and the flow path between both ports opens slowly. Therefore,
Pressure fluid with a flow rate limited according to the opening amount will flow between both ports, and the actuator connected to this control valve will be started slowly due to the gradual pressure rise. The driving speed of the main valve body can be adjusted by a supply control needle.

When the pilot chamber communicates with the discharge port by switching the pilot valve, and the fluid pressure at the supply port decreases, the main valve body is urged by the set spring and returns to its original position due to the decrease in internal pressure in the pilot chamber as the pilot fluid is discharged, and the supply is resumed. The port and the output port are shut off, but at this time, the discharge flow rate of the pilot fluid is limited by the discharge control needle, so the main valve body gradually returns to its original state, and the flow path between both ports is slowly closed. be done. Therefore, the actuator connected to this control valve is brought to a slow stop by controlling the flow rate at the end of the stroke. The return speed of the main valve body can be adjusted by a discharge control needle.

[Effect of idea]

Since the supply flow rate and discharge flow rate of the pilot fluid are controlled by needles, the main valve body can be operated slowly during both drive and return strokes, thereby allowing the actuator to slowly start and return. A slow stop can be realized.

In addition, since the speed of the actuator can be controlled by a single control valve and multiple speed controllers are not required, the configuration and piping of the control circuit can be greatly simplified. Speed control can be performed more smoothly than in the case of

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail based on the drawings. In FIG. 1, 1 is a main valve part, 2 is a pilot valve part, and a body 1a in the main valve part 1 is a body 1a of the pressure fluid. A supply port 3 and an output port 4 are provided inside the body, and a supply opening 3a and an output opening 4a communicating with each of the ports 3 and 4 are provided inside the body.
A sleeve 5 with a
A spool valve 6 as a main valve body for controlling the opening amount of a flow path between the two is slidably inserted, and one end of the spool valve 6 is connected to a pilot valve part 2 from a supply port 3.
A pilot chamber 7 is formed through which a pilot passage hole 8 is opened, and a set spring 9 is compressed between the other end of the spool valve 6 and a needle screw 10 screwed onto the body 1a. , the needle screw 10 can be moved forward and backward by rotation of the knob 10a.

Further, the pilot valve section 2 is connected to the supply hole 1.
1. It has a body 2a equipped with an output passage hole 12 and a discharge passage hole 13, and a valve chamber 14 in which each of the above-mentioned passage holes 11 to 13 opens is provided in the body 2a, and
A supply valve seat 15 and a discharge valve seat 16 are provided between the output passage hole 12 and the supply passage hole 11 and the discharge passage hole 13, respectively, and a poppet-shaped pilot valve 17 that opens and closes these valve seats 15 and 16 alternately. The valve chamber 14
A solenoid section 18 serving as an electromagnetic drive mechanism is connected to one side of the pilot valve 17.

The supply passage hole 11 is communicated with the supply pilot passage hole 8a via a supply control needle 19 which is attached so that its opening amount can be adjusted from the outside, and the output passage hole 12 is connected to the output pilot passage hole 8a. The hole 8b communicates directly with the pilot chamber 7, and the discharge hole 13 communicates with a discharge hole 21 provided in the body 2a and open to the outside through a discharge control needle 20 that can be adjusted from the outside. ing.

In addition, 22 and 23 in the figure are the pilot valves 17.
and a spring that biases the needle screw 10.

Next, the operation of the control valve having the above configuration will be explained.

In the switching state shown in FIG. 1, when pressure fluid such as compressed air is supplied to the supply port 3, this fluid is blocked in the main valve portion 1 by closing the output opening 4a, while the pilot passage hole 8 It also reaches the pilot valve section 2 through the valve, but it is also shut off here by closing the supply valve seat 15 by the pilot valve 17.

Here, when the pilot valve 17 is moved to the left by energizing the solenoid part 18, the supply valve seat 15 is opened and the discharge valve seat 16 is closed, so that the supply passage hole 11 and the output passage hole 12 are communicated with each other. However, the pilot fluid flows into the pilot chamber 7. The flow rate of the pilot fluid at this time is restricted by the supply control needle 19, so the fluid pressure in the pilot chamber 7 rises relatively slowly, and the spool valve 6 is set due to the acting force accompanying this rise. Because it moves slowly to the left against the spring 9, the output opening 4a
is opened at a corresponding speed, and fluid from the supply port 3 flows to the output port 4 according to the opening amount. The switching speed of the spool valve 6 can be arbitrarily set by adjusting the opening amount of the supply control needle 19.

Next, when the power to the solenoid section 18 is cut off, the pilot valve 17 is returned by the spring 22 to open the discharge valve seat 16 and close the supply valve seat 15, so that the pilot fluid in the pilot chamber 7 is It flows from the passage hole 12 to the discharge passage hole 13 and is gradually discharged from the discharge port 21 while being subjected to flow rate restriction by the discharge control needle 20. Therefore, the return of the spool valve 6 by the set spring 9 is also slow, and the output opening 4a is closed at a corresponding speed. The return speed of the spool valve 6 can be arbitrarily set by adjusting the discharge control needle 20.

FIG. 2 shows the relationship between the pilot fluid pressure and time in the control valve described above, and the flow rate (opening amount) of the fluid flowing through the output opening 4a and time.
Arrows a and b indicate that the slope of that section can be varied by adjusting the feed control needle and the discharge control needle, respectively, and the dashed line
This shows the characteristics when the pilot valve section is constructed only by an on/off switching solenoid valve without a needle.

Further, FIG. 3 illustrates a control circuit for controlling the cylinder 24 using the control valve A described above, and since the operation of the control valve A is the same as in the case described above, the explanation will not be repeated. For the sake of avoidance, the same parts will be given the same reference numerals and their explanations will be omitted. In addition,
In the figure, reference numeral 25 indicates an electromagnetic switching valve, and reference numeral 26 indicates a pressure fluid source. By using this control valve A, the control circuit can be greatly simplified, and the cylinder 24 has the characteristics shown in FIG. Therefore, it can be controlled.

That is, as shown by the solid line in the figure, the cylinder 24
At the start of the stroke, the cylinder 24 starts slowly by slowly opening the output opening in the main valve part 1, and at the end of the return stroke of the cylinder, by slowly closing the output opening in the main valve part 1. The cylinder 24 stops slowly. Therefore, prevention of the cylinder from popping out at the start of the stroke and cushioning at the end of the stroke are performed.

In addition, what is shown by the broken line in FIG. 4 is the characteristic of the cylinder when a control valve whose switching speed cannot be controlled is used.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the control valve of the present invention, Fig. 2 is a diagram showing its characteristics, and Figs. 3 and 4 are cylinder diagrams showing an example of use of the control valve of the present invention. FIG. 5 is a control circuit diagram of a cylinder showing a conventional example, and FIG. 6 is an explanatory diagram of its operation. 1... Main valve part, 2... Pilot valve part, 3...
Supply port, 4... Output port, 6... Spool valve, 7... Pilot chamber, 8... Pilot passage hole, 8a... Supply side pilot passage hole, 8b... Output side pilot passage hole, 11... Supply Through hole, 12...
...output hole, 13...discharge hole, 14...valve chamber,
17...Pilot valve, 18...Solenoid part,
19... Needle for supply control, 20... Needle for discharge control, 21... Discharge port.

Claims (1)

[Scope of utility model registration request] A main valve element that controls the opening amount of the flow path between the ports is arranged in the main valve part equipped with a pressure fluid supply port and an output port, and a pilot through hole is provided at the end of the main valve element to connect the supply port to the main valve part. A pilot chamber is formed into which pilot fluid pressure for driving the main valve body is introduced through the pilot valve part, and a set spring is compressed at the other end of the main valve body, and a supply hole is provided in the pilot valve part. A valve chamber into which an output hole and a discharge hole open is provided, and a pilot valve for selectively communicating the supply hole and the discharge hole with the output hole is disposed within the valve chamber, and the pilot valve is arranged to switch the supply hole and the discharge hole into communication with the output hole. The side pilot passage hole is communicated with the supply control needle whose opening amount can be adjusted, and the output passage hole and the pilot chamber are directly communicated with each other, and the discharge port and the pilot valve part are provided with a discharge port that opens to the outside. A control valve, characterized in that the pilot valve is connected to the pilot valve through a discharge control needle whose opening amount can be adjusted, and an electromagnetic drive mechanism is attached to the pilot valve.