JPS5917078A - Flow rate control valve - Google Patents

Abstract

PURPOSE:To balance two balance chambers with each other through offsetting of the biassing forces of a liquid pressure exerted on a valve body, by constituting a valve such that a piston having the same pressure receiving area as that of a valve body for closing an internal hole is secured to a part outside the internal hole of the coupling rod of a pneumatic pressure servo-motor between the pneumatic servo-motor and the valve body, and two balance chambers are formed at both sides of the piston. CONSTITUTION:In a flow rate control valve for controlling cooling water of a water cooled type internal combustion engine for vehicle, the position of a valve body 40 is controlled through a vacuum pressure applied to a part 20a of a pneumatic pressure servo-motor 20 and the elastic force of a coil spring 50 to control the quantity of cooling water flowing from an inlet hole 10a to an outlet hole 10b. A piston 60, having the approximately same pressure receiving area as that of the valve body 40, is secured to a spot positioned outside an internal hole 10c of a rod 30, and balance chambers R1 and R2 are formed above and below the piston 60. Where a flow rate is controlled, a liquid pressure, exerted on the underside of the valve body 40, is exerted on the upper side of the piston 60, and the liquid pressure, exerted on the upper side of the valve body 40, is exerted on the underside of the piston 60 to balance them with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow control valve in which a valve body is driven by a pneumatic servo motor to control the flow rate of liquid such as water or oil in accordance with the pressure applied to the pneumatic servo motor.

This type of flow control valve is used, for example, to control the cooling water of a water-cooled internal combustion engine, and includes a housing that has an inlet port and an outlet port, and an inner hole that communicates both ports. a pneumatic servo motor coaxially assembled with the inner hole on one side; a rod connected at one end to the drive section of the pneumatic servo motor and having the other end positioned within the inner hole and movable in the axial direction; A valve body fixed to a portion of the rod located in the inner hole and a valve seat formed in the middle of the inner hole to control the flow rate of liquid flowing from the inlet port to the outlet port, and driving the air pressure servomorph. A spring is provided to bias the rod and the valve body against the force.

By the way, in the conventional flow rate control valve of this type, when controlling the flow rate, the valve body is pushed in the axial direction by the pressing force generated by the difference in hydraulic pressure acting on both sides of the valve body, so the air pressure servo is It is difficult to accurately control the flow rate of liquid in response to the pressure applied to the motor.

The present invention was made in view of the above circumstances, and its purpose is to balance the pressing force of the liquid pressure acting on the valve body and adjust the flow rate of the liquid according to the pressure applied to the pneumatic servo motor. It is about precise control. In order to achieve this object, in the present invention, a piston having approximately the same pressure receiving area as the valve body is fixed to a portion located outside the inner hole of the lot between the pneumatic servo motor and the valve body. A first balance chamber communicating with a chamber in which one side of the valve body is exposed and a second balance chamber communicating with a chamber in which the other side of the valve body is exposed are formed on both sides of the piston. In the flow control valve configured in this way, it is possible to apply approximately the same hydraulic pressure to both sides of the piston as the hydraulic pressure acting on both sides of the valve body, and the pressing force of the hydraulic pressure acting on the piston causes the valve body to It is possible to cancel out the pressure force of the hydraulic pressure that acts on the system and achieve balance. Therefore, the valve body is not pushed in the axial direction by the pressing force of the hydraulic pressure, and the flow rate of the liquid can be accurately controlled according to the pressure applied to the pneumatic surfomotor. In addition, in this flow control valve, the pressing force of the hydraulic pressure acting on the valve body is canceled out and balanced, so a large driving force is not required to drive the valve body, making the pneumatic servo motor smaller and lighter. It is possible,
Cost reduction can be achieved. Furthermore, by downsizing the pneumatic servo motor, the amount of gas flowing in and out of the pneumatic servo motor is reduced, improving operational responsiveness.

Embodiments of the present invention will be described below based on the drawings. FIG. 1 shows a first embodiment of the present invention, in which a flow control valve V1 shown here is used to control cooling water of a water-cooled internal combustion engine for a vehicle, and a housing 10
, pneumatic servo motor 20 , rod 30 , and valve body 40
and a coil spring 50. The housing 10 includes a main body 11, a cap 12, and joints 13 and 14.
The inlet boat 10a is connected to the cooling water outlet of the water-cooled internal combustion engine, and the outlet boat 10b is connected to the cooling water inlet of the radiator.
It also has a stepped inner hole 10C that allows both ports 10a and 10b to communicate with each other. Atmospheric pressure servo motor 2
0 is assembled coaxially with the inner hole 10c on the upper side of the housing 10, and a diaphragm piston 21 as a driving section is disposed inside. The diaphragm piston 21 divides the inside of the pneumatic servo motor 20 into an upper chamber 20a and a lower chamber 20b, so that vacuum pressure as a control signal is applied to the upper chamber 20a through the boat 22, and to the lower chamber 20b. It is configured so that atmospheric pressure is always applied. The rod 30 is composed of a hollow rod body 31 and a pair of upper and lower plugs 32, 33, etc., and is connected to the diaphragm piston 21 at the upper end, and moves up and down (
i.e., in the axial direction). A guide 34 is fixed (screwed) to the lower end of this rod 30, and this guide 34 is fitted into an inner hole 12a formed in the cap 12 so as to be slidable in the axial direction. Note that the inner hole 12a of the cap 12 and the inner hole 10C of the housing 10 pass through a sling l-34a formed in the guide 34.

The valve body 40 is fixed to the lower part of the rod 30, and controls the flow rate of cooling water flowing from the inlet boat 10a to the outlet boat 10b by a valve seat 10d (i.e., a step) formed in the middle part of the inner hole lOC. do.

The coil spring 50 is disposed in the upper chamber 20a of the pneumatic servo motor 20, and acts against the driving force of the pneumatic servo motor 20 (the upward force obtained by the differential pressure between the two chambers 20a, 20b). In order to bias the rod 30, valve body 40, etc., the diaphragm piston 21. The rod 30, the valve body 40, etc. are urged downward.

In the flow rate control valve (1) configured as described above, the position of the valve body 40 is controlled by the vacuum pressure applied to the upper chamber 20a of the pneumatic servo motor 20 and the elastic force of the coil spring 50, and the position of the valve body 40 is controlled from the inlet boat 10a to the outlet port 10a. The flow rate of the cooling water flowing into the boat 10b is controlled according to the no. 1 cum pressure.

Therefore, in this embodiment, the pneumatic servo motor 20
A piston 60 having approximately the same pressure receiving area as the valve body 40 is fixed to the inner hole 10c of the rod 30 between the valve body 40 and the valve body 40, and a balance chamber R3°R2 is formed on both the upper and lower sides of the piston 60. has been done. Upper balance room R
1 is a hole 31a bored in the upper part of the mouth/throat body 31;

It communicates with the chamber Ra where the lower side of the valve body 40 is exposed through the inner hole 31b of the rod body 31 and the hole 3LC drilled in the lower part of the rod body 31, and the lower chamber 20b of the pneumatic servo motor 20 is connected to the seal member 15. Separated by The lower balance chamber R2 is connected to the valve body 4 through the small diameter part of the inner hole 10C.
It communicates with chamber Rb where the upper side of 0 is exposed.

Therefore, in this embodiment, when controlling the flow rate of the flow rate control valve V1, the hydraulic pressure acting on the lower side of the valve body 40 acts on the upper side of the piston 60, and the hydraulic pressure acting on the upper side of the valve body 40 acts on the lower side of the piston 60. Therefore, a pressing force of approximately the same magnitude as the upward pressing force due to the difference in hydraulic pressure acting on both the upper and lower surfaces of the valve body 40 acts downward on the piston 60, and the pressing force of the hydraulic pressure acting on the rod 30 is canceled out and balanced. Therefore, in the flow rate control valve (1), the valve body 40 is not pushed upward by the pressure of the cooling water flowing in the inner hole 10c, and is cooled according to the vacuum pressure applied to the pneumatic servo motor 20. Water flow rate can be precisely controlled. In addition, the flow control valve ■1
In the above, since the pressing force of the hydraulic pressure acting on the valve body 40 is canceled out and balanced, a large driving force is not required to drive the valve body 40, and the pneumatic servo motor 20 can be made smaller and lighter. It is possible to reduce costs. Further, by downsizing the pneumatic servo motor 20, the amount of gas flowing in and out of each chamber 20a, 20b of the pneumatic servo motor 20 is reduced, improving operational responsiveness.

FIG. 2 shows a second embodiment of the present invention, and in the flow control valve 2 shown here, a second outlet boat 10e connected to the cooling water inlet of the water-cooled internal combustion engine is attached to the cap 12A. It is formed. Also, rod 30A
The threaded portion 33a of the lower plug 33A is formed long, and the second valve body 70 is attached to the threaded portion 33a so as to be movable in the axial direction. Second valve body 7
0 constitutes an on-off valve with a valve seat 10f formed on the cap 12A, and is biased downward by a coil spring 71 whose upper end is engaged with the valve body 40. Since the other configurations are the same as those of the flow control valve (1) described above, the same reference numerals are given and the explanation thereof will be omitted.

In the flow control valve (2) configured as described above, when high vacuum pressure is applied to the upper chamber 20a of the air pressure servomorph 20, the rod 30A moves upward and the valve body 40 moves toward the valve seat 1.
0d and the second valve body 70 is seated on the valve seat 10. f
The communication between the inlet boat 10a and the outlet boat 10b is cut off, and the inlet boat 10a and the second outlet boat 10e are communicated with each other.

In other cases, it is substantially the same as the flow control valve v1 described above, and communication between the inlet boat 10a and the second outlet boat 10e is cut off, and the air pressure servo motor 2
The flow rate of the cooling water flowing from the inlet boat 10a to the outre throat boat 1Ob is controlled in accordance with the vacuum pressure applied to the upper chamber 20a.

FIG. 3 shows a third embodiment of the present invention, and in the flow control valve shown here, the lower balance chamber R2 and the small diameter portion of the inner hole 10c are separated by a sealing member 16. . In addition, the rod 30B is connected to the hollow rotor main body 3.
1B and 1, a pair of upper and lower plugs 32B and 33B, a pair of upper and lower cup-shaped rubber bushings 34B and 35B, and a small diameter pipe 36B.

Therefore, in this embodiment, the mouth/7F main body 31B
, an annular passage P1 formed by the pipe 36B and both rubber bushes 34B and 35B, and the rod body 31B.
The lower balance chamber R2 and the chamber Rb where the upper side of the valve body 40 is exposed communicate through the through holes H formed by the holes drilled in the pair of upper and lower stoppers 31B and 38B fixed thereto, and the pipe 36B and both rubber bushes 3
A passage P2 formed by 4B and 35B and a pipe 3
6B1 Through hole H formed by the holes drilled in both rubber holes 34B, 35B and the rod body 31B.
2, the upper balance chamber R1 and the chamber Ra in which the lower side of the valve body 40 is exposed are in communication. Since the other configurations are substantially the same as those of the flow control valve (2) described above, the same reference numerals are given and the explanation thereof will be omitted.

In the flow rate control valve V configured in this way, the lower balance chamber R2 and chamber Rh communicate with the passage Pj through the through hole H1, and the hydraulic pressure acting on the upper side of the valve body 40 is transferred to the lower side of the piston 60. acts directly on Therefore, compared to both of the flow rate control valves V, V2 described above, the pressing force of the hydraulic pressure acting on the valve body 40 can be more accurately canceled out and balanced. The rest is the same as the flow control valve ■λ described above, so
The explanation will be omitted.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a flow control valve showing a first embodiment of the invention, FIG. 2 is a longitudinal sectional side view of a flow control valve showing a second embodiment of the invention, and FIG. 3 is a longitudinal sectional side view of a flow control valve showing a second embodiment of the invention. FIG. 7 is a vertical cross-sectional side view of a flow control valve showing a third embodiment. Explanation of symbols 10...Housing, 10a...Inlet/7 boat, 10b...Outlet port, 10C...
Inner hole, 10d... Valve seat, 20... Atmospheric pressure servo motor, 21... Diaphragm piston, 30... Rod, 40... Valve body, 50... Spring, 60...
Piston, Ra... Chamber where the lower side of the valve body is exposed, Rb.
... A chamber in which the upper side of the valve body is exposed, R1... A balance chamber formed above the piston, R2... A balance chamber formed below the piston. Applicant Aisin Seiki Co., Ltd. Agent Patent Attorney Teru Hase - Figure 2 IUe Figure 3

Claims (1)

[Claims] A housing having an inlet port and an outlet port as well as an inner hole communicating these ports, an example of a pneumatic servo motor assembled coaxially with the inner hole in the housing, 7 a drive section of the pneumatic servo motor; A rod that is connected at one end and whose other end is located within the inner hole and is movable in the axial direction, and a valve that is fixed to the portion of the rod that is located within the inner hole and formed in the middle of the inner hole. A flow control valve comprising a valve body that controls the flow rate of liquid flowing from the inlet port to the outlet port by a seat, and a spring that biases the rod and the valve body against the driving force of the pneumatic servo motor. , a piston having approximately the same pressure receiving area as the valve body is fixed to a portion of the rod located outside the inner hole between the pneumatic servo motor and the valve body, and one side of the valve body is exposed on both sides of the piston. A flow control valve comprising: a first balance chamber that communicates with a chamber in which the other side of the valve body is exposed; and a second balance chamber that communicates with a chamber in which the other side of the valve body is exposed.