JPS6230346B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow control valve, and more particularly to reducing the leakage flow rate of a spool-type flow control valve.

Conventionally, in spool-type flow control valves, due to the structure of the valve mechanism, the spool slides on the sleeve, so an appropriate clearance is required between both parts, resulting in fluid leakage from the spool-type valve mechanism. It is well known that fluid leakage from a poppet type valve mechanism is larger than that from a poppet type valve mechanism, and fluid leakage from a spool type flow control valve causes problems such as shortening the flow rate control range.

Therefore, the technical object of the present invention is to eliminate fluid leakage from the valve portion of a spool-type flow control valve with a simple structure.

The technical measures taken to solve the above-mentioned technical problems consist of a housing having an inlet and an outlet for the spool-type fluid control valve, and a sleeve part protruding from the inner wall of the housing and communicating its inner cavity with the outlet. and a valve spool slidably fitted to the outer periphery of the sleeve portion, the outer diameter of the distal end portion of the sleeve portion being smaller than the outer diameter of the portion on which the valve spool slides, The valve spool is formed in the housing to define a chamber from which the sleeve portion protrudes, and to communicate with and shut off a passage constantly communicating with the inlet by sliding the valve spool. When the valve spool is slid, the valve spool is brought into contact with the distal end surface of the sleeve portion and blocks communication between the inlet and the outlet.
A valve disengaged from the distal end surface upon engagement with the spool is arranged to completely stop fluid flow from the inlet to the outlet when the valve spool assumes a position blocking the passageway from the chamber. It was configured as follows.

As mentioned above, the valve that opens and closes the inlet and outlet is placed in a chamber formed by the valve spool, which is normally closed by a spring, and opened by engagement with the valve spool when the valve spool slides. The simple valve arrangement eliminates fluid leakage from the clearance required between the valve spool and the sleeve in a spool-type flow control valve.

In the embodiment shown in the drawings, air is supplied into the intake manifold of the engine according to the level of negative pressure within the intake manifold of the engine in order to prevent the afterburn phenomenon when the vehicle is decelerated.
The flow control valve 10 includes a housing 11, a sleeve 12 protruding from the inner wall of the housing, a valve spool 13 that is slidably fitted on the outer circumference of the sleeve 12, and a negative valve that controls the sliding of the valve spool 12. A pressure actuator 14 is provided. The housing 11 has an atmospheric pressure introduction port 11c for the negative pressure actuator 14 in addition to an inlet 11a and an outlet 11b. The cover 15 joined to the upper end of the housing 11 has a negative pressure introduction port 15a.
is provided. Housing 11 and cover 15
The space defined by the piston 16 and the diaphragm 17 is divided into an upper chamber 18 communicating with the port 15a and a lower chamber 19 communicating with the port 11c. A biasing spring 20 is provided. piston 1
Reference numeral 6 denotes a rod portion 16 that protrudes from the lower surface of the rod portion 16 and slidably extends through the partition wall portion 11d of the housing 11.
It has a. The port 15a is a negative pressure outlet port 21 of the engine intake manifold 21.
a, and the port 11c is connected to the air passage 24 between the carburetor bench lily portion 22 and the air cleaner 23.
(always at approximately atmospheric pressure).

The internal cavity of the sleeve 12 communicates with the outlet 11b, and the distal end 1 of the sleeve 12 communicates with the outlet 11b.
The outer diameter of 2a is the portion 12 that slides on the valve spool 13.
It is formed smaller than the outer diameter of b. A recess 13a is provided in the upper part of the valve spool 13, and a cover 25 is hermetically fitted and fixed in the recess 13a to define a chamber 26 from which the distal end 12a of the sleeve 12 projects. Disposed within this chamber 26 are a valve 27 that comes into contact with and leaves the distal end surface of the sleeve 12, and a spring 28 that urges the valve 27 to come into contact with the distal end surface of the sleeve 12. The valve spool 13 has a passage 1 that constantly communicates with the inlet 11a.
3b is formed so as to communicate with and shut off from the chamber 26 by sliding the valve spool 13. The valve spool 13 is attached to the bottom of the recess 13a of the valve spool 13.
A suitable number of protrusions 13c are provided for forcibly separating the valve 27 from the distal end surface of the sleeve 12 when the valve 27 occupies a position communicating the passage 13b with the chamber 26. A spring 29 for sliding the valve spool 13 upward in the drawing is stretched between the valve spool 13 and the inner wall surface of the housing 11.
The tip of the rod portion 16a of the piston 16 is brought into contact with the cover 25 so as to be slid against the piston 9.
The inlet 11a and the outlet 11b communicate with the passage 24 and the intake manifold 21, respectively.

The operation of the above configuration will be explained next.
The state shown in the drawing shows a state where the car is running at a constant speed, and the negative pressure inside the engine intake manifold 21 is not as high as the negative pressure when the car is decelerating. Yotsute piston 1
The upward thrust in the drawing that acts on the spring 20
Therefore, the piston 16 pushes the valve spool 13 downward in the drawing, and this pushing force is greater than the force of the spring 29 and the valve spool 13
is positioned in the illustrated position to block the passage 13b from the chamber 26, and the valve 27 is brought into contact with the distal end surface of the sleeve 12 by a spring 28. Therefore,
Air on the inlet 11a side passes from the passage 13b through the relative sliding portion of the valve spool 13 and sleeve 12 to the chamber 26.
However, since the flow from the chamber 26 into the internal cavity of the sleeve 12 is completely stopped by the valve 27, the flow from the inlet 11a to the outlet 11b is completely stopped.
Air flow to is completely stopped.

As is well known, when an automobile decelerates, the negative pressure inside the intake manifold 21 becomes considerably high, so the thrust force acting on the piston 16 due to the pressure difference between the upper chamber 18 and the lower chamber 19 exceeds the mounting load of the spring 20, and the piston 16 Move upward in the drawing. Following this, the valve spool 13 is slid upward in the drawing by the spring 29, and at the same time the passage 13b communicates with the chamber 26, the valve 27
3c, it is pushed upward in the drawing and separated from the distal end surface of the sleeve 12. Therefore, the entrance 11a is the passage 1
3b, the chamber 26, and the internal cavity of the sleeve 12 are open to the public and communicate with the outlet 11b, and air purified by the air cleaner is supplied into the intake manifold 21 from the passage 24 via the flow control valve 10. The amount by which the valve spool 13 slides upward in the drawing during this operation responds to the height of the negative pressure within the intake manifold 21, and the amount by which the valve spool 13 slides upward in the drawing from the passage 13b to the chamber 17 increases. Since the passage area increases, the flow rate of air flowing from the inlet 11a to the outlet 11b is controlled according to the level of negative pressure within the intake manifold 21.

In the embodiment described above, the sliding movement of the valve spool 13 was controlled by the negative pressure actuator 14.
Control can also be provided by other means, for example by a solenoid.

As described above, according to the present invention, fluid leakage can be eliminated with an extremely simple configuration, the control characteristics of the spool type flow control valve can be improved, and the flow rate control area by the spool and the airtight area by the valve can be connected. can be arbitrarily adjusted by the height dimension of the protrusion, thereby providing effects such as being able to arbitrarily set the control characteristics of the spool type flow control valve.

[Brief explanation of the drawing]

The drawing is a sectional view of one embodiment of the present invention. 11...Housing, 11a...Inlet, 11b
... Outlet, 12 ... Sleeve, 13 ... Valve spool, 26 ... Chamber, 27 ... Valve, 28 ... Spring.

Claims (1)

[Claims] 1. A housing having an inlet and an outlet, a sleeve part protruding from an inner wall of the housing and communicating its internal cavity with the outlet, and a valve spool slidably fitted to the outer periphery of the sleeve part, The outer diameter of the distal end portion of the sleeve portion is formed to be smaller than the outer diameter of the sliding portion of the valve spool, and the valve spool defines a chamber in the housing from which the sleeve portion protrudes and constantly communicates with the inlet. A passage is formed in such a manner that it communicates with and is cut off from the chamber by sliding, and the valve spool in the chamber is normally brought into contact with the distal end surface of the sleeve portion by a spring to cut off communication between the inlet and the outlet and the valve spool slides. when a valve is disposed that is disengaged from the distal end surface by engagement with the valve spool to completely prevent fluid flow from the inlet to the outlet when the valve spool is in a position blocking the passageway from the chamber. A flow control valve characterized in that the flow rate is stopped at .