JPH035742Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pilot operated fluid control valve which is arranged in a fluid circuit and controls the flow of fluid with a small pilot operating force.

[Conventional technology]

Conventionally, this type of pilot operated fluid control valve is
As shown in FIG. 3, an inflow passage leads to a valve body 35, which is provided in a communication passage that communicates between a fluid inflow passage 32 and an outflow passage 33. At the same time, the fluid in the action chamber 37 formed at the back of the valve element, which communicates with the inflow passage side via the throttle passage 36, and the spring 38 are made to act in the seating direction, and the pilot valve element 39 By the actuation operation, the action chamber 37 is communicated with the outflow passage side, and the valve body 35 is moved away from the valve seat 34 by the difference in the action force generated on both ends thereof.

[Problem that the invention attempts to solve]

However, since the throttle passage 36 is formed with a small diameter hole and a large pressure difference occurs between the two end faces of the fitting part of the valve body 35, fluids such as cutting oil that are easily contaminated by fine chips and external dust When controlling the flow of
The throttle passage 36 of the small diameter hole may be blocked by foreign matter in the fluid, or the foreign matter may be pushed into the fitting portion of the valve body 35 due to the pressure difference between its two ends.
It had the disadvantage that malfunctions occurred frequently and it could not be used satisfactorily.

The present invention eliminates these drawbacks, and is a pilot operating fluid control system that maintains approximately the same pressure between both ends of the valve body fitting part, reduces the influence of foreign matter mixed in the fluid, and achieves good operation. The purpose is to provide a valve.

[Means for solving problems]

The structure of the present invention, which was created to solve this problem, is such that a fluid is inserted into the hole so as to sit on or leave the valve seat formed in the communication path that communicates between the fluid inflow path and the fluid outflow path. The valve is actuated by the action force of the valve body urged in the seating direction by a spring provided in conjunction with the valve seat, and the pilot fluid that flows into the action chamber formed at the back and located opposite the valve body through the valve seat. A piston that lifts its body from the valve seat, a pilot valve element installed in a pilot passage communicating between an inflow passage and an action chamber on the back of the piston to open and close the pilot passage, and an operation installed on the valve body side to operate the pilot valve element. A filter is provided in the pilot passage on the side of the inflow passage from the pilot valve body, and a throttle passage is communicated with the working chamber so that the pilot fluid that has flowed in is throttled and distributed along the outer periphery of the piston to the outflow passage. It is characterized by having a configuration.

[Effect]

In this structure of the present invention, when the pilot valve body is opened, a portion of the fluid in the inflow passage is filtered as pilot fluid and flows into the action chamber through the pilot passage to actuate the piston, and the valve body is pressed against the spring by the piston. It resists and is pushed and leaves the valve seat. When the pilot valve body is closed, the pilot fluid in the working chamber is flowing through the throttle passage to the outflow passage, so the pressure force of the piston to press the valve body is released and the valve body is seated on the valve seat by the spring. The piston is returned to its original position. Therefore, it is possible to maintain substantially the same pressure between both ends of the valve body fitting part, and a large gap is created in the fitting part, eliminating the possibility of foreign matter being pushed in. Moreover, the pilot fluid flowing into the piston side that operates the valve body is It is cleaned by a filter to reduce the effects of foreign matter in the fluid and ensure good operation.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIGS. 1 and 2, 1 is a valve body, which is composed of a main body 1A and a sub-body 1B that are integrally connected. The main body 1A includes a fluid inflow passage 2 and an outflow passage 3.
A communication passage 4 is provided inside so that both passages 2 and 3 communicate with each other. Reference numeral 5 denotes a cylindrical body press-fitted and fixed into a communication hole 6 forming a communication passage 4, and a valve seat 7 is formed at the open end on the inflow passage 2 side. Reference numeral 8 denotes a valve body for opening and closing the communication passage 4, which is slidably inserted into a guide hole 9 coaxially connected to the communication hole 6, and its tapered tip portion is seated on the valve seat 7 for sealing engagement. It has been set up so that it can be achieved. The valve body 8 has a flat notch 10 in the axial direction on the outer periphery of the fitting portion, and communicates an action chamber 11 formed at the back with the communication passage 4 on the side of the inflow passage 2 from the valve seat 7. A spring 12 is housed in the action chamber 11 and biases the valve body 8 in the seating direction. 13 is a piston that presses the valve body 8 and presses the valve body 8 through the valve seat 7.
A fitting hole 1 is connected coaxially with the flow hole 6 at a position opposite to the flow hole 6.
The valve body 8 is slidably inserted into the valve body 8, and its tip portion formed to have a small diameter extends into the communication hole 6 and the cylinder body 5, and is disposed close to the tip surface of the valve body 8. A throttle passage 16 is provided inside the piston 13 so that fluid in a working chamber 15 formed at the back of the piston 13 flows along the outer periphery of the piston 13. 17 is a pilot valve body disposed in a pilot passage 18 formed to communicate between the inflow passage 2 and the working chamber 15 at the back of the piston 13;
Large diameter hole 2 of bush 19 fixed between 1B
0, and the spherical portion of a steel ball 21 press-fitted into the tip is seated on the pilot valve seat 22. A cutout groove 23 is provided in the axial direction on the outer periphery of the fitting portion of the pilot valve body 17 to communicate between both ends. 24 is a spring that urges the pilot valve body 17 in the seating direction, and 25 is a tip that urges the pilot valve body 17.
This is a push rod that presses the steel ball 21 in the unseating direction, and the other end is provided to extend outside the sub-body 1B. Reference numeral 26 denotes an electromagnetic device as an operating device consisting of a fixed core 27, a coil 28, and a movable core 29. It is attached to the side of the sub-body 1B where the push rod 25 extends, and when the coil 28 is energized, the fixed core 27 is activated. The pilot valve body 17 is moved away from the pilot valve seat 22 via the push rod 25 by the acting force of the movable iron core 29 that is attracted. Reference numeral 30 denotes a filter device having a cylindrical filter 31, which is provided in a cartridge shape on the inflow passage 2 side of the pilot passage 18 from the pilot valve body 17 so that it can be easily attached and detached from the outside of the main body 1A.

Next, the operation of this configuration will be explained.

In the illustrated state of FIGS. 1 and 2, it is assumed that the inflow passage 2 is connected to the fluid pressure source side, and the outflow passage 3 side is connected to the low pressure side. now,
When the coil 28 of the electromagnetic device 26 is energized to attract the movable iron core 29, the pilot valve body 17 is pushed by the push rod 25 so as to be separated from the valve seat 22 against the spring 24, and the pilot passage 18 is opened. do. A portion of the fluid supplied to the inflow passage 2 when the pilot passage 18 is open is filtered to remove foreign matter by the filter 31, and is then passed through the outer circumferential cutout groove 23 of the pilot valve body 17.
It flows into the action chamber 15 through the valve seat 22 and the piston 1
3 and is throttle-controlled by the throttle passage 16 to flow to the small-diameter tip of the piston 13 and into the outflow passage 3. The piston 13 slides downward in FIG. 2 due to the acting force of the pilot fluid flowing into the action chamber 15, and presses the valve body 8 away from the valve seat 7 against the spring 12, causing the fluid in the inflow passage 2 to be pushed away from the valve seat 7. flows to the outflow passage 3 via the communication passage 4 and the valve seat 7.
When the valve body 8 slides in the unseating direction, the fluid in the working chamber 11 flows out to the communicating path 4 side through the notch 10 on the outer periphery of the valve body with small resistance, and the valve body 8 can operate smoothly and quickly.

Then, when the current to the coil 28 is cut off, the pilot valve body 17 is biased by the spring 24 and the steel ball 2
1 on the pilot valve seat 22 and the pilot path 1
8 to the closed state. The force exerted by the pilot fluid on the piston 13 when the pilot passage 18 is closed is due to the fact that the pilot fluid in the action chamber 15 is in the throttle passage 1.
Since it is flowing out from 6 to the outflow passage 3, it is solved,
The valve body 8 is urged by the spring 12 and seats on the valve seat 7 to close the communication passage 4, and the piston 13 is urged by the spring via the valve body 8 and returns to its original position.

With this operation, when the valve body 8 is seated on or removed from the valve seat 7, the pressure between the communication passage 4 and the action chamber 11 at both ends of the fitting portion of the valve body 8 is approximately the same. Often, the fitting portion is sufficient to hold the valve body 8 in the guide hole 9, and a large gap can be obtained at the fitting portion of the valve body 8, thereby eliminating the possibility of foreign matter being forced into the fluid. In addition, since the pilot fluid flowing into the action chamber 15 side of the piston 13 that operates the valve body 8 is made clean by the filter 31, the throttle passage 16 is blocked by foreign matter that has entered the piston 13.
It is possible to prevent the fluid from malfunctioning, and to obtain good operation with reduced effects of foreign matter mixed in the fluid.

Furthermore, since the filter 31 filters a small flow rate of the pilot fluid, the filter 31 has a small passage capacity, so even if it is used for a long period of time, the filtration effect does not deteriorate much and maintenance can be simplified. Furthermore, the pilot fluid that has flowed into the working chamber 15 of the piston 13 is passed through the throttle passage 16 along the outer periphery of the piston 13 to the outflow passage 3.
Therefore, the inflow and outflow passages 2 and 3 are formed on the inner peripheral surface of the fitting hole 14 into which the piston 13 is fitted.
It is possible to prevent foreign matter in the fluid flowing between them from adhering, and the influence of foreign matter on the piston 13 can be further reduced.

[Effect of idea]

As described above, according to the pilot-operated fluid control valve of the present invention, the pilot-operated fluid control valve is fitted into the hole so as to be seated on or removed from the valve seat formed in the communication passage that communicates between the fluid inflow passage and the fluid outflow passage. The valve body is actuated by the action force of the valve body urged in the seating direction by a spring provided in the valve seat, and the pilot fluid that flows into the action chamber formed at the back of the valve body, which is disposed opposite to the valve body through the valve seat. A piston that is unseated from a valve seat, a pilot valve element that is installed in a pilot passage that communicates between an inflow passage and an action chamber on the back of the piston to open and close the pilot passage, and an operating device that is installed on the valve body side and operates the pilot valve element. A filter is provided in the pilot passage on the side of the inflow passage from the pilot valve body, and a throttle passage is provided in communication with the working chamber so that the pilot fluid that has flowed in is throttled and distributed along the outer circumference of the piston to the outflow passage. As a result, the influence of foreign matter mixed in the fluid is reduced, and good operation of the valve body and piston can be obtained, and the valve body and the piston can be disposed and used in fluid circuits for a wide range of applications.

Further, since the flow rate of the pilot fluid passing through the filter is small, even if a filter with a small passage capacity is used for a long period of time, the decrease in filtration effect can be minimized, and maintenance management is easy. Moreover, since the pilot fluid in the action chamber at the back of the piston is passed from the throttle passage to the outflow passage along the outer circumference of the piston, foreign matter in the fluid flowing between the inflow and outflow passages is prevented from adhering to the actuating part of the piston. It has features such as being able to prevent foreign matter from entering the piston and further reducing the effects of foreign matter entering the piston.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a pilot operating fluid control valve showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the line - in Fig. 1, and Fig. 3 is a pilot operating fluid control valve showing a conventional example. FIG. 2 is a partially omitted vertical cross-sectional view of the valve. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Inflow passage, 3... Outflow passage, 7... Valve seat, 8... Valve body, 13... Piston, 11, 15... Action chamber, 16... Throttle passage,
31...Filter.

Claims (1)

[Scope of utility model registration request] a valve body fitted into a hole and biased in the seating direction by a spring so as to be seated on or separated from a valve seat formed in a communication passage that communicates between a fluid inflow passage and an outflow passage; A piston is disposed opposite to the valve body through the valve seat, and is actuated by the action of the pilot fluid that flows into the action chamber formed at the back of the piston to unseat the valve body from the valve seat. It has a pilot valve body installed in a pilot passage that communicates between the working chambers to open and close the pilot passage, and an operating device attached to the valve body side to operate the pilot valve body, and a pilot valve body is provided on the inflow passage side from the pilot valve body of the pilot passage. A pilot operating fluid control valve comprising a filter and a throttle passage communicating with the working chamber so that the pilot fluid flowing into the working chamber is throttled and distributed along the outer periphery of the piston to the outflow passage.