JPH11311367A - Flow rate control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate control valve capable of improving startability at the time of engine low temperature without increasing the number of parts. SOLUTION: This control valve opens and closes a valve element 10 in accordance with temperature change of an engine as a temperature sensing part 11 directly senses temperature change of the engine by connecting an air passage pipe 20 to the upstream side of a throttle valve, connecting an air passage pipe 21 to the neighbourhood of a nozzle of an injector, connecting an air passage pipe 22 to an intake manifold and installing a case 11b in which wax 11a is stored in a cooling water passage of the engine. Consequently, air valve 100 is capable of carrying out air assist to promote atomization of injecting fuel at the time of engine low temperature and adjusting first idle rotation and improving startability at the time of engine low temperature. Additionally, as the air valve 100 does not require special parts such as a circuit, a harness, etc., to open and close the valve element 10, it is possible to reduce the number of the part items.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a flow control valve,
In particular, an internal combustion engine (hereinafter, an "internal combustion engine" is referred to as an engine)
The present invention relates to a flow control valve suitable for controlling a flow rate of air in the bypass passage by providing a bypass passage for bypassing the throttle valve.

[0002]

2. Description of the Related Art Conventionally, in an engine equipped with an electronically controlled fuel injection device (hereinafter referred to as "fuel injection device"), a bypass passage is provided to bypass a throttle valve, and an air flow rate in the bypass passage is provided. A flow control valve for controlling pressure is known.
No. 0473 has proposed a flow control valve.

[0003]

In the above-mentioned conventional flow control valve, air assist which opens and closes the valve body by an electric signal and supplies air near the nozzle of the injector to promote atomization of the injected fuel is possible. At the same time, air is supplied to the intake manifold to adjust the first idle rotation.

However, in the flow control valve disclosed in Japanese Patent Application Laid-Open No. 4-140473, it is necessary to send an electric signal to the valve body. For example, when the valve body is opened and closed according to the temperature of the engine, a detector such as a sensor for detecting the temperature of the engine is provided, and the temperature detected by the detector is converted into an electric signal, and a circuit for sending the electric signal to the valve body is provided. There is a problem in that parts such as a motor and a harness are required, and the number of parts increases.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a flow control valve capable of improving the startability at a low engine temperature without increasing the number of parts. . It is another object of the present invention to provide a flow control valve that can be mounted on various types of engines with minor component changes.

It is still another object of the present invention to provide a flow control valve capable of performing air assist even when the engine temperature is high.

[0007]

According to the flow control valve of the present invention, an inlet port, a plurality of outlet ports,
And a valve body provided in a housing having a fluid passage communicating with the inlet port and the plurality of outlet ports, and changes the opening ratio of the fluid passage according to the reaction of the temperature sensing portion that senses and reacts to the temperature change. For this reason, for example, one of a plurality of outlet ports is connected near the nozzle of the injector, and a temperature sensing portion is attached at a position where the engine temperature is transmitted, such as a cooling water passage of the engine, so that a temperature change of the engine can be directly detected. Then, the valve body is opened and closed in accordance with a change in the temperature of the engine, and air assist for the injector is performed when the engine temperature is low, so that the startability of the engine can be improved. Furthermore, since a special circuit for opening and closing the valve element and parts such as a harness are not required, the number of parts can be reduced.

According to the flow control valve according to the second aspect of the present invention, the housing includes a casing having an inlet port,
Since the cover can be divided into a cover having a plurality of outlet ports, the cover is changed according to the type of the engine to which the flow control valve is to be assembled, so that the flow control valve can be assembled to various types of engines with a slight change of parts. Can be attached. The cover can be fixed to the casing by screws or press-fitting. When the cover is fixed to the casing by press-fitting, the degree of freedom in assembling the flow control valve to the engine, such as the direction of the outlet port to the engine, is improved.

According to the flow control valve according to the third aspect of the present invention, since the valve body has the hole communicating the inlet port and the plurality of outlet ports, air is supplied to the vicinity of the nozzle of the injector even when the engine is at a high temperature. This makes it possible to promote the atomization of the injected fuel when the engine temperature is high, and to improve the exhaust emission when the engine temperature is high.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIGS. 1 and 2 show a first embodiment in which the present invention is applied to an air valve of an engine. The air valve of the first embodiment divides the air introduced into the air valve into two systems, bypassing the throttle valve of the engine, and sends out the air from two ports. 1 and 2 show a state at the time of low temperature of the engine.

As shown in FIG. 2, the air valve 100 is
A casing 23, a cover 24, the temperature sensitive section 11,
It is constituted by a valve body 10 and is attached to a cooling water pipe 30 of the engine via an O-ring 19 provided in a casing 23. The casing 23 has a substantially cylindrical shape, and has an air passage pipe 20 connected to an upstream side of a throttle valve (not shown). An air passage 23 a as a fluid passage is formed inside the casing 23. The air passage pipe 20 is provided integrally with the casing 23, and an air inlet passage 20 a as an inlet port is formed inside the air passage pipe 20.

The cover 24 has a bottomed cylindrical shape,
An air passage 24 a as a fluid passage is formed inside the cover 24 by being fixed to the casing 23 by screws or press-fitting via a seal 25. Also cover 2
4 has an air passage pipe 21 connected to the vicinity of a nozzle of an injector (not shown) and an air passage pipe 22 connected to an intake manifold (not shown). The air passage pipe 21 is fitted into the cover 24, and an air outlet passage 21 a as an outlet port is formed inside the air passage pipe 21. The air passage pipe 22 is fitted into the cover 24, and is provided inside the air passage pipe 22 as an air outlet passage 22a as an outlet port.
Are formed. The air passage pipe 21 and the air passage pipe 22 have substantially the same inner diameter. Here, the casing 23 and the cover 24 constitute a housing.

The temperature sensitive section 11 has a case 11b, a wax 11a, a seal 11c, and a piston 12. The case 11 b has a cylindrical shape with a bottom and is mounted in a cooling water passage 30 a inside the cooling water pipe 30 so as to protrude from the casing 23. Therefore, case 11b is constantly exposed to engine cooling water in cooling water passage 30a. Wax 11a is stored in case 11b, and wax 11a changes from a solid phase to a liquid phase at a predetermined temperature, and undergoes volume expansion accompanying a phase change from the solid phase to the liquid phase. In addition, above a predetermined temperature, volume expansion occurs in accordance with the temperature rise. The piston 12 is provided on the opening end side of the case 11b via a seal 11c, and is located inside the casing 23. The distal end portion 12a of the piston 12 on the side opposite to the case is in contact with a sleeve 13 of the valve body 10 described later. The piston 12
It moves upward in FIG. 2 with the expansion of the volume of the wax 11a stored in the case 11b. Therefore,
The temperature responsive unit 11 directly detects a change in the temperature of the engine,
It is configured to be able to respond to changes in engine temperature.

As shown in FIG. 1, the valve body 10 includes a large retainer 18, a valve member 16, a bias spring 17,
It is composed of a sleeve 13, a small retainer 15, and a hold spring 14. The large retainer 18 is fixed in the casing 23 and is formed in a stepped cylindrical shape. The large retainer 18 includes a small diameter portion 18c and a large diameter portion 1c.
8d, a step 18e is formed on the inner wall between the small-diameter portion 18c and the large-diameter portion 18d, and an opening 18b is formed at an end face of the small-diameter portion 18c on the side opposite to the large-diameter portion. A valve seat 18a is formed on an inner peripheral wall between the opening 18e and the opening 18b.

The valve member 16 has a cylindrical shape with a bottom.
It is provided inside the large retainer 18 and has a bottom portion 26, a small diameter portion 16b, a medium diameter portion 16c, and a large diameter portion 16d. The outer diameter of the small diameter portion 16b is equal to the opening 1 of the large retainer 18.
The bottom 26 protrudes from the opening 18b to the outside of the large retainer 18.
A contact portion 16a having a conical tapered surface is formed between the small diameter portion 16b and the middle diameter portion 16c, and the contact portion 16a can be seated on the valve seat 18a of the large retainer 18. When the contact portion 16a is seated on the valve seat 18a, the air passage 23a and the air passage 24a are shut off.
6a is separated from the valve seat 18a, so that the air passage 23
a and the air passage 24a communicate with each other. Since the outer diameter of the middle diameter part 16c is formed smaller than the inner diameter of the small diameter part 18c of the large retainer 18, the seating property of the contact part 16a on the valve seat 18a is ensured. A flange 16e is formed on the opening end side of the large diameter portion 16d. A step 16f is formed on the inner wall between the small diameter portion 16b and the middle diameter portion 16c.

The bias spring 17 has one end in contact with the stepped portion 18e of the large retainer and the other end in the flange 1 of the valve member 16.
6e. The bias spring 17 urges the valve member 16 in a direction in which the contact portion 16a separates from the valve seat 18a. The sleeve 13 has a bottomed cylindrical shape with a protruding head 13c, and a flange 13a formed at an open end.
And an inner bottom portion 13b and a jaw portion 13 formed on the head portion 13c
d, and the inner bottom portion 13b is in contact with the tip portion 12a of the piston 12. The small retainer 15 is
b, and a disc shape having a flange portion 15a formed around the concave portion 15b. The flange portion 15a contacts the step 16f of the valve member 16, and the concave portion 15a
3 is in contact with the jaw 13d. Hold spring 1
4 has one end in contact with the flange 13 a of the sleeve 13 and the other end in contact with the flange 15 a of the small retainer 15. The hold spring 14 biases the sleeve 13 and the small retainer 15 in a direction in which the flange 13 a of the sleeve 13 is separated from the small retainer 15, that is, in a direction in which the jaw 13 d of the sleeve 13 is in close contact with the concave portion 15 a of the small retainer 15. I have. Therefore, the sleeve 13, the hold spring 1
4. The small retainer 15 and the valve member 16
It is configured to be able to be interlocked integrally with the movement of.

Next, regarding the operation of the air valve 100,
This will be described with reference to FIGS. FIG. 3 shows the relationship between the temperature of the engine and the flow rate of air supplied to each of the air outlet passages 21a and 22a. (1) At a low temperature immediately after the start of the engine, the temperature of the cooling water of the engine is low, so that the wax 11a is contracted, and as shown in FIGS. The contact portion 16a is separated from the valve seat 18a. Therefore, the air passage 23a and the air passage 24
a communicates with the air inlet passage 20a and the air outlet passages 21a and 22a. Therefore, the air bypassing the throttle valve is introduced into the air valve 100 from the air inlet passage 20a, is supplied to the vicinity of the injector nozzle from the air outlet passage 21a through the air passages 23a and 24a, and from the air outlet passage 22a. It is also supplied to the intake manifold. At this time, the opening ratio of the air passage formed by the abutting portion 16a and the valve seat 18a is maximized.
As shown in (1), the flow rate of air supplied from the air valve 100 to the vicinity of the nozzle of the injector and to the intake manifold becomes maximum. Further, since the inner diameter of the air passage pipe 21 and the inner diameter of the air passage pipe 22 are substantially the same,
The flow rate of air supplied to the vicinity of the nozzle of the injector is substantially the same as the flow rate of air supplied to the intake manifold.

(2) During the warm-up operation of the engine, if the temperature of the cooling water of the engine exceeds a predetermined temperature, the wax 11a changes from a solid phase to a liquid phase, so that the wax 11a expands, and accordingly, the piston 12 Is moved upward in FIG. 1, the sleeve 13, the hold spring 14, the small retainer 15, and the valve member 16 are moved upward in FIG. 1 against the biasing force of the bias spring 17. For this reason, the opening ratio of the air passage formed by the contact portion 16a and the valve seat 18a is smaller than immediately after the start of the engine.
As shown in FIG.
From 0, the flow rate of air supplied to the vicinity of the nozzle of the injector and to the intake manifold decreases as the temperature rises.

(3) After the engine is warmed up, if the temperature of the engine cooling water becomes high, the wax 11a expands in accordance with the temperature rise, and the piston 12 moves further upward, so that the sleeve 1
3. When the hold spring 14, the small retainer 15, and the valve member 16 move further upward, the contact portion 16a is seated on the valve seat 18a, so that the air passage 23a and the air passage 24a are shut off. Then, as shown in FIG.
When the temperature of the engine is high, air is not supplied from the air valve 100 to the vicinity of the nozzle of the injector and to the intake manifold. At this time, since the wax 11a continues to expand due to a rise in temperature, the temperature sensitive portion 11 generates an extremely large load, and the case 11b may be damaged. However, in the first embodiment, the load acting on the piston 12 more than necessary is absorbed by the bending of the hold spring 14, and it is possible to prevent an excessive increase in stress.

In the first embodiment, the air passage pipe 2
0 is connected to the throttle valve upstream side, and the air passage pipe 21 is connected near the nozzle of the injector,
By connecting the air passage pipe 22 to the intake manifold and mounting the case 11b containing the wax 11a in the cooling water passage 30a of the engine, the temperature sensing section 11 directly senses the temperature change of the engine, and the engine temperature change. The valve body 10 is opened and closed in accordance with. Therefore, the air valve 100 can perform the air assist for promoting the atomization of the injected fuel at the time of the engine low temperature and can adjust the first idle rotation, thereby improving the startability at the time of the engine low temperature. it can.

(Second Embodiment) A second embodiment in which a hole is formed in the bottom portion 26 of the valve member 16 of the first embodiment will be described with reference to FIG. The substantially same parts as those in the first embodiment shown in FIG. FIG. 5 shows the relationship between the engine temperature and the flow rate of air supplied to each air outlet passage.

As shown in FIG. 4, the bottom 26 of the valve member 16
Is formed with a hole 26a that connects the air passage 23a and the air passage 24a. For this reason, in the second embodiment, after the engine is warmed up, the cooling water of the engine becomes hot, the wax 11a expands in accordance with the temperature rise, and even if the contact portion 16a is seated on the valve seat 18a, The air passage 23a and the air passage 24a are not blocked. That is, the hole 26a
Thus, the air inlet passage 20a and the air outlet passages 21a and 22a are always in communication. Therefore, as shown in FIG. 5, it is possible to supply air from the air valve 100 to the vicinity of the nozzle of the injector even at a high temperature.

In the second embodiment, it is possible to perform air assist for supplying air to the vicinity of the injector nozzle even at a high engine temperature, to promote atomization of the injected fuel at a high engine temperature, It is possible to improve exhaust emissions at In the embodiments of the present invention described above, the valve 10
Since a special circuit or a component such as a harness for opening and closing the device is not required, the number of components can be reduced.

Further, in a plurality of embodiments of the present invention, members constituting the housing of the air valve are divided into a casing 23 and a cover 24, an air inlet passage 20a is formed in the casing 23, and an air outlet passage is formed in the cover 24. 2
Since the air valves 1a and 22a are formed, the air valve can be mounted on various types of engines by changing the cover according to the type of the engine on which the air valve is mounted, with a slight change of parts. The cover 2 is press-fitted.
By fixing 4 to casing 23, the degree of freedom in assembling the air valve to the engine, such as the direction of air outlet passages 21a and 22a to the engine, is improved.

In the above embodiments, the air passage pipe 2
1 and the inside diameter of the air passage pipe 22 are substantially the same. However, in the present invention, by changing the inside diameter of each pipe, the air flow supplied to the vicinity of the nozzle of the injector and the air supplied to the intake manifold are changed. It is possible to vary the flow rate. Further, in the above-described plurality of embodiments, the present invention is applied to the air valve 100 including the wax-type temperature-sensitive section 11 having the wax 11a. However, the present invention is applied to the air valve including the bimetal-type temperature-sensitive section. Is also good.

[Brief description of the drawings]

FIG. 1 shows a first embodiment in which the present invention is applied to an air valve of an engine.
FIG. 3, showing an example, is an enlarged view of a main part of FIG. 2.

FIG. 2 is a first view in which the present invention is applied to an air valve of an engine.
It is a longitudinal section showing an example.

FIG. 3 is a characteristic diagram showing a relationship between an engine temperature and a flow rate of air supplied to each air outlet passage in the first embodiment.

FIG. 4 shows a second embodiment in which the present invention is applied to an air valve of an engine.
It is a longitudinal section showing an example.

FIG. 5 is a characteristic diagram showing a relationship between an engine temperature and a flow rate of air supplied to each air outlet passage in the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Valve body 11 Temperature sensitive part 11a Wax 12 Piston 13 Sleeve 14 Hold spring 15 Small retainer 16 Valve member 16a Contact part 17 Bias spring 18 Large retainer 18a Valve seat 20a Air inlet passage (inlet port) 21a Air outlet passage (outlet port) 22a Air outlet passage (outlet port) 23 Casing (housing) 23a Air passage (fluid passage) 24 Cover (housing) 24a Air passage (fluid passage) 100 Air valve (flow control valve)

Claims (3)

[Claims] A housing having an inlet port, a plurality of outlet ports, and a fluid passage communicating with the inlet port and the outlet port; a temperature-sensitive portion that senses and reacts to a temperature change; and is provided in the housing. A valve body that varies an opening ratio of the fluid passage in accordance with a reaction of the temperature sensing unit. 2. The flow control valve according to claim 1, wherein the housing can be divided into a casing having the inlet port and a cover having the outlet port. 3. The flow control valve according to claim 1, wherein the valve body has a hole communicating the inlet port and the outlet port.