JPS595260Y2 - Temperature detection type switching valve - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a temperature detection type switching valve having the functions of two three-way valves.

Conventionally, as shown in FIG. 4, two three-way valves 30 and 40 are used, and the first three-way valve 30 connects the first actuator A to either the first or second signal source B or C. Switch and connect,
The second three-way valve 40 connects the second actuator D to the first
It is configured to switch and connect to either the third signal source B or E.

Since this conventional type uses two switching valves, the installation space becomes large.

The present invention aims to reduce the installation space by obtaining the functions of the two three-way valves with one switching valve.

In the present invention, a valve element that moves between two seat surfaces, another valve element that comes into contact with and separates from this valve element, and still another valve element that follows and operates in accordance with this other valve element are placed in a pressure chamber. place,
By bringing the valve body into contact with and separating from the two seat surfaces, the connection relationship of the three ports is switched to obtain the function of the first three-way valve, and by bringing the valve body into contact with and separating from the other valve body, the connection relationship between the three ports is changed. Among the ports, the port that always communicates with the pressure chamber (common port) and other ports are opened and closed, and further ports that open into the pressure chamber and communicate with the above common port are opened and closed between the above-mentioned further ports. It is opened and closed by a valve body to obtain the function of a second three-way valve, so only one switching valve is required, and the installation space can be reduced.

Embodiments of the present invention shown in the drawings will be described below.

In the first embodiment shown in FIG. 1, 1 is a first housing, and 1a is a first seat surface provided on the first housing 1, which represents the lower end surface of the first housing 1 in the figure. .

2 is a second housing fixed to the first housing 1 by tightening, and 2a is a second housing provided on the second housing 2.
The sheet surface faces the first sheet surface 1a.

3 is a thermal expansion member made of thermowax, for example, whose coefficient of thermal expansion increases rapidly when the temperature reaches a set temperature; 4 is a housing member that stores the thermal expansion member 3; It is fixed and exposed in the object to be detected (cooling water of an automobile engine, not shown here).

5 is a diaphragm attached to the opening of the storage member 4;
A semi-fluid substance 6 is housed in a chamber formed by the second housing 2 and the diaphragm 5, and the semi-fluid substance 6 has a property that its volume does not change due to compression.

7 is a piston made of rubber, 8 is a sheet made of Teflon, 9 is a shaft made of metal, and seat 8 is the piston 7.
This prevents the shaft 9 from coming into direct contact with the shaft 9.

The piston 7 also serves as a seal for the semi-liquid substance 6.

10 is a first pressure chamber formed by the first housing 1; 11 is a diaphragm chamber of a secondary air switching valve (not shown) that controls air that is secondarily supplied to an engine (not shown); and the first pressure chamber 10. a first pressure port communicating with the
A second pressure port 12 communicates the atmosphere with the first pressure chamber 10 via an air filter (not shown), and its lower end in the figure projects into the first pressure chamber 10 .

The tip of the protruding portion is the third sheet surface 12a.

13 is a first compression coil spring installed in the first pressure chamber 10; 14 is a first valve body that comes into contact with the shaft 9 and moves within the first pressure chamber 10 following the shaft 9; do.

Reference numeral 15 denotes a cylindrical support member that is installed in the first pressure chamber 10 and is held in contact with the first valve body 14 by a first compression coil spring 13, and the opening at the upper end in the figure is a second port. The diameter is difficult enough to insert the protruding part of 12,
The diameter of the cylindrical portion is larger than the diameter of the opening.

Further, this support member 15 is displaced following the first valve body 14.

16 is a second valve body installed inside the support member 15, the outer diameter of which is smaller than the inner diameter of the cylindrical portion of the support member 15;
larger than the diameter of the opening.

16a is a fourth seat surface, which represents the upper end surface of the second valve body 16 in the figure.

Reference numeral 17 denotes a second compression coil spring installed inside the support member 15, which presses the second valve body 16 upward in the figure.

1B is a third valve body provided with a through hole in the center for passing the shaft 9. Even if the through hole passes through the shaft 9, gas does not flow between the inner wall of the through hole and the outer peripheral surface of the shaft 9. It is large enough to pass through.

Further, the third valve body 18 has an outer peripheral portion having a larger diameter than the outer diameter of the first valve body 14 .

18a is a fifth seat surface, which represents the upper end surface of the outer peripheral portion of the third valve body 18 in the drawing.

Reference numeral 18b denotes a sixth seat surface, which represents the lower end surface of the outer peripheral portion of the third valve body 18 in the drawing.

Reference numeral 19 denotes a third pressure port provided in the second housing 2, which connects the second pressure chamber 20 and a diaphragm chamber of an exhaust gas control valve (not shown) that controls exhaust gas recirculated to the intake system of the engine (not shown). are communicating.

Reference numeral 21 denotes a fourth pressure port provided in the second housing 2, which communicates with an EGR port of a carburetor (not shown).
EGR port negative pressure of the carburetor is introduced into the pressure chamber 22 of the engine.

Reference numeral 23 denotes a fifth pressure port provided in the second housing 2, which introduces negative intake pressure of an engine (not shown) into the fourth pressure chamber 24.

25 has an opening at one end connected to the third valve body 18 and an opening at the other end connected to the second valve body 18.
The third pressure chamber 22 and the fourth pressure chamber 24 are separated from each other by a cylindrical soft sealing member such as a bellows that is in close contact with the housing 2 .

Reference numeral 26 denotes a third compression coil spring, one end of which contacts the third valve body 18 and the other end of which contacts the sealing member 25 via a stopper 27.
The sealing member 25 comes into contact with the outer peripheral portion of the second housing 2 and acts to press the sealing member 25 onto the second housing 2 .

The stopper 27 serves to prevent the third compression coil spring 26 from coming into direct contact with the sealing member 25.

28 is a sealing member that seals between the first housing 1 and the second housing 2.

Next, the operation of the present invention having the above configuration will be explained.

When the engine cooling water temperature is below the set temperature, the thermal expansion of the thermal expansion member 3 is small, and as shown in FIG.
Valve body 18, shaft 9, support member 15, second valve body 1
6 is displaced downward in the figure, so that the sixth seat surface 18b and the second seat surface 2a, the first valve body 14 and the third valve body 18 are in close contact with each other, and the fifth seat surface 18
Since the diaphragm chamber of the secondary air switching valve is separated from the first pressure port 11.a and the first seat surface 1a, and the third seat surface 12a and the fourth seat surface 16a are separated from each other. The diaphragm chamber 10 of the exhaust gas control valve communicates with the second pressure port 12 through the gap between the third seat surface 12a and the fourth seat surface 16H, and the diaphragm chamber of the exhaust gas control valve communicates with the third pressure port 19, Second pressure chamber 20, fifth seat surface 18a
and the first pressure chamber 10 through the gap between the first seat surface 1a and the first seat surface 1a.
The diaphragm chambers of both the exhaust gas control valve and the secondary air switching valve are connected to the second pressure port 12 through the gap between the third seat surface 12a and the fourth seat surface 16H. It is released to the atmosphere through a filter.

In addition, the intake negative pressure and the EGR port negative pressure reach the fourth pressure chamber 24 or the third pressure chamber 22, respectively, but the third pressure chamber 22 is separated by the third valve body 1B and the soft seal member 25. The fourth pressure chamber 24 is also sealed with the first valve body 14, the third valve body 1B and the soft sealing member 25.
Since it is sealed from other pressure chambers by
GR port negative pressure is 1st to 3rd pressure capo) 11.12
．． It can't reach 19.

Therefore, neither the secondary air switching valve nor the exhaust gas control valve opens, and secondary air injection and exhaust gas recirculation are not performed.

When the engine cooling water temperature exceeds the set temperature, the coefficient of thermal expansion of the thermal expansion member 3 rapidly increases and the thermal expansion member 3 expands rapidly. The first valve body 14 overcomes the resistance of the first compression coil spring 13 and is displaced upward in the figure.

Further, the third valve body 18 is also displaced upward in the figure following the first valve body 14 due to the pressing force of the third compression coil spring 26, and the sixth seat surface 18b and the second seat surface 2a At the same time as they are separated, the fifth sheet surface 18a and the first sheet surface 1a come into close contact with each other.

Moreover, since the second valve body 16 also follows the first valve body 14 and is displaced upward, the fourth seat surface 16 a and the third seat surface 12 a come into close contact.

Since the first valve body 14 is further displaced upward in the figure, the first valve body 14
The valve body 14 and the third valve body 18 are separated.

Therefore, the intake negative pressure is distributed between the fifth pressure port 23, the fourth pressure chamber 24, the inner wall of the through hole of the third valve body 18, and the shaft 9.
The gap, the first pressure chamber 10 and the first pressure port 11 act on the diaphragm chamber of the secondary air switching valve, while the EGR port negative pressure acts on the fourth pressure port 21. Acting on the diaphragm chamber of the exhaust gas control valve via the third pressure chamber 22, the gap between the sixth seat surface 18b and the second seat surface 2a, the second pressure chamber 20 and the third pressure port 19, Regular secondary air injection and exhaust gas recirculation takes place.

Also, at this time, between the second pressure port 12 and the first pressure chamber 10, there are the third seat surface 12a and the fourth seat surface 16H.
It is blocked by close contact.

FIG. 2 shows the main part of the second embodiment of the present invention.
The upper end of the valve body 16' in the figure is made to protrude from the opening of the support member 15, and the position of the third seat surface 12a is changed accordingly.

Operation is the same as in the previous embodiment.

FIG. 3 shows the main parts of the third embodiment of the present invention.
The valve body 14' has the function of integrating the first valve body 14 and the support part 15 in the first embodiment, and the second valve body 14' is made of a ring-shaped flexible member baked onto the first valve body 14'. Valve body 16″
has the function of the second valve body 16 in the first embodiment.

The second valve body 16'' is in close contact with the third seat surface 12a', thereby blocking the connection between the second pressure port 12 and the first pressure chamber 10.

In the above embodiment, the soft seal member 25 is arranged inside the third compression coil spring 26, but it is of course possible to reverse this arrangement, and the method for attaching the soft seal member 26 is also as follows. It is also possible to use adhesive, etc.
The present invention is not limited to the structure shown in the above embodiment.

Since the present invention has the above-described configuration, the following effects can be obtained.

(a) In the conventional device shown in FIG. 4, each valve 30.40 is actuated by a respective thermal expansion member, so there are two valves 30,
40 may occur, but in the present invention, the three valve bodies operate in response to a change in the volume of one thermal expansion member, so such a timing difference does not occur.

(b) Since one of the five ports is commonly used for each three-way valve, the number of ports is reduced by one, and the number of signal conduits is accordingly reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram showing a first embodiment of the switching valve of the present invention;
2 and 3 are sectional views of essential parts showing second and third embodiments of the present invention, and FIG. 4 is a sectional view of a conventional example. 1.2...first and second housings, 1a...first
seat surface, 2a... second seat surface, 3... thermal expansion member, 9... shaft, 10... pressure chamber, 11...
...first pressure port, 12...second pressure port,
14...first valve body, 16.1B', 16''...
Second valve body, 18... Third valve body, 19... Third pressure port, 21... Fourth pressure port, 23...
Fifth pressure port, 25... soft seal member.

Claims (1)

[Claims for Utility Model Registration] A thermal expansion member that is disposed at an end of a housing and whose volume changes according to the temperature of a detected object; and a shaft that changes inside the housing according to the volume change of the thermal expansion member. a first valve body whose one end surface abuts the tip of the shaft and which is displaced within a pressure chamber formed in the housing following the shaft; and a first valve body located on the other end surface side of the first valve body. , a second valve body that is displaced within the pressure chamber following the first valve body; and a second valve body that has a diameter larger than the diameter of the first valve body and that has the shaft in a through hole formed in a central portion. When the temperature of the object to be detected is below the set temperature, one end surface on the thermal expansion member side is in close contact with the second seat surface formed on the housing, and the other end surface is in close contact with the second seat surface formed on the housing. A third end surface that is in close contact with one end surface, and when the temperature is higher than a set temperature, the other end surface is in close contact with the first seat surface formed on the housing and is separated from the second seat surface and one end surface of the first valve body. a flexible seal member having a substantially cylindrical shape, through which the shaft is passed, one end opening of which is in close contact with one end surface of the third valve body, and the other end opening of the flexible seal member is in close contact with the housing; a first pressure port that always communicates with the pressure chamber; and a second pressure port that opens into the pressure chamber and that opens only when the temperature is equal to or higher than a set temperature.
a second pressure port that is closed by a valve body; and a second pressure port that communicates with the pressure chamber through a gap between the other end surface of the third valve body and the first seat surface only when the temperature is below the set temperature. a fourth pressure port that communicates with the third pressure port through a gap between one end surface of the third valve body and the second seat surface only when the temperature is higher than a set temperature; Only when the temperature is higher than the set temperature, the inner peripheral surface of the sealing member, the inside of the through hole of the third valve element, and the gap between one end surface of the first valve element and the other end surface of the third valve element are closed. a fifth pressure port that communicates with the pressure chamber through the temperature detection type switching valve.