JP2002349725A - Flow control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow control valve 1 that can prolong a product life to a valve lockup owing to a widened clearance between a seat portion 7 of a valve 4 and a housing sealing surface 6. SOLUTION: The flow control valve 1 adopts an offset arrangement of an operational center axis (shaft 5) of the valve 4 for controlling an opening area of a bypass passage 2 formed in a housing 3 and a center axis 9 of the housing sealing surfaces 6, so that a wide clearance is formed between the seat portion 7 of the valve 4 and the housing sealing surfaces 6. An allowable deposition amount of a corrosion product can be increased, and then a product life to a valve lockup can be prolonged. If the flow control valve 1 is used as an engine speed control valve, the valve 4 can be held closed during normal travel to set a low engine speed, improve fuel economy and solve the disadvantage that speed is increased against a driver's intention.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve for controlling a flow rate of a fluid, and more particularly to an idle control valve for controlling an intake air amount bypassing a throttle valve in order to maintain an idle speed of an engine at a predetermined value. It relates to a rotation speed control valve.

[0002]

2. Description of the Related Art As a prior art, as shown in FIGS. 2 and 3, there is an idle speed control valve 100 for controlling an intake air amount bypassing a throttle valve when an engine is idling. The idle speed control valve 100 includes an aluminum housing 102 mounted on an outer wall surface of a throttle body 101 that forms an intake passage to an engine, and a valve 103 that opens and closes a bypass passage 110 formed in the housing 102. And bearings 105 and 106 for rotatably supporting both ends of a shaft 104 of the valve 103, and a motor actuator 107 for driving the shaft 104 of the valve 103.

[0003] The motor actuator 107 includes a yoke housing and a stator core for generating a magnetic field, a rotor magnet 108 integrally provided at the left end of the shaft 104 in the figure, and a field coil 109 for exciting the stator core. I have. And the valve 103
When the first current value flows through the field coil 109 built in the motor actuator 107, the motor is rotated by the magnetomotive force of the field coil 109 to close the bypass passage 110, as shown in FIG. When a second current value smaller than the first current value flows through the field coil 109, the bypass passage 11
The opening area of 0 is expanded to a predetermined value. In the conventional idle rotation speed control valve 100, when the operation center axis of the valve 103 and the center axis of the housing seal surface 121 are substantially coincident with each other and the field coil 109 is not energized, FIG.
As shown in (b), the seat portion 131 of the valve 103
The gap formed between the housing and the housing seal surface 121 is very small.

[0004]

However, in the conventional idle rotation speed control valve 100, if the valve 103 is left in a half-open state for a long period of time such as half a year to one year, the seat portion 131 of the valve 103 becomes inactive. A gap formed between the housing seal surface 121 and the housing seal surface 121 is small.
Are corroded and corrosion products are clogged in the gaps.
As a result, the valve 103 locks and the amount of intake air that bypasses the throttle valve cannot be controlled. Further, when the valve 103 is locked at the position shown in FIG. 3B, the valve 103 opens the bypass passage 110 even during normal traveling, so that the engine speed is set to be high, fuel efficiency is deteriorated, and (driver)
However, there is a problem that the running speed of the vehicle is increased contrary to the intention of the above.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flow control valve capable of extending the life of a product that reaches a valve block by increasing the clearance between a valve seat portion and a housing sealing surface. .

[0006]

According to the first aspect of the present invention, the center axis of the valve for adjusting the opening area of the fluid passage formed in the housing is shifted from the center axis of the housing sealing surface. With this arrangement, the gap formed between the seat portion of the valve and the housing sealing surface increases. As a result, the allowable amount of deposition of corrosion products can be increased, and the product life up to the valve block can be extended.

According to a second aspect of the present invention, the valve is a rotary valve that swings about an operation center axis of the valve. According to the third aspect of the present invention, the flow control valve is used as the engine speed control valve for controlling the amount of intake air bypassing the throttle valve of the engine. State, the engine speed is set high,
It is possible to solve the problems that the fuel efficiency is deteriorated and the running speed of the vehicle is increased against the driver's intention.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Structure of Embodiment] An embodiment of the present invention will be described based on an embodiment with reference to the drawings. here,
FIG. 1A shows a fully closed state of the flow control valve.
(B) is the figure which showed the half open state of the flow control valve.

The flow control valve 1 of this embodiment is an idle speed control valve (idle speed control valve) for controlling the amount of intake air that bypasses a throttle valve (not shown) of the engine when the engine is idling. A control valve (ISCV), which is used as a housing 3 having a bypass passage 2, a valve (valve element) 4 for adjusting the opening area of the bypass passage 2, and is integrated with the valve 4 through an operating center of the valve 4. It is composed of a shaft 5 that rotates likewise and a motor actuator (not shown) that drives the shaft 5.

The housing 3 is made of, for example, aluminum die-cast or resin, and is connected to an outer wall surface of a throttle body (not shown). An air inlet (not shown) and an air outlet (not shown) of the bypass passage 2 are opened on the side wall surface (throttle body side end surface) of the housing 3, and the air inlet port is located upstream of the throttle valve. , The air outlet communicates with the intake passage (air passage) in the throttle body, and the air outlet communicates with the intake passage in the throttle body downstream of the throttle valve.

The bypass passage 2 has a substantially U shape between the air inlet and the air outlet. In the middle of the bypass passage 2, a convex housing seal surface (valve seat) 6 on which the valve 4 is seated is provided in an annular shape. The valve 4 is a rotary valve that swings about an operation center axis (shaft 5) of the valve 4, and has an arc-shaped seat portion 7 facing the housing seal surface 6 of the housing 3. The central axis of operation of the valve 4 is provided on a projecting piece 8 protruding in a substantially horizontal direction from the central axis 9 of the housing seal surface 6 of the housing 3. A substantially cylindrical shaft 5 penetrates the hole. The central axis 9 of the housing seal surface 6 of the housing 3 is offset from the central axis of operation of the valve 4 (the shaft 5).

The motor actuator includes a field coil controlled by an electronic control unit (ECU) (not shown), a magnetic path forming member (yoke housing and stator core) magnetized by a magnetomotive force of the field coil, and a shaft 5. And a rotor magnet (both not shown) integrally provided at the end. The field coil is wound around the outer periphery of the coil bobbin, and is electrically connected to a terminal molded on the connector.

[Operation of Embodiment] Next, the operation of the flow control valve 1 of the embodiment will be briefly described with reference to FIG. When the field coil is energized through the electronic control unit, the magnetic path forming member is magnetized to generate an attractive force. Then, since the rotor magnet is rotated by the attraction force corresponding to the current value of the field coil, the shaft 5 is rotated. Therefore, the valve 4 rotates around the operation center axis (the shaft 5). When the arc-shaped seat portion 7 of the valve 4 rotates to a position facing the housing seal surface 6 of the housing 3, the opening area of the bypass passage 2 becomes the smallest, and the bypass passage 2 is fully closed (FIG. 1 (a)). Further, when the energization of the field coil is stopped, the attractive force of the field coil is demagnetized and the shaft 5 rotates in the reverse direction, so that the valve 4 rotates in the reverse direction about the operation center axis (shaft 5). The opening area of the bypass passage 2 is the largest, and the bypass passage 2 is in a half-open state (see FIG. 1B).

[Effects of the Embodiment] As described above, the flow control valve 1 of the present embodiment has the operation center shaft of the valve 4 for adjusting the opening area of the bypass passage 2 formed in the housing 3 and the housing seal. The central axis 9 of the surface 6 was displaced. That is, since the operation center axis of the valve 4 and the center axis 9 of the housing sealing surface 6 are offset, the gap formed between the seat portion 7 of the valve 4 and the housing sealing surface 6 is increased. As a result, the allowable amount of deposition of the corrosion product can be increased, so that the corrosion product is less likely to be clogged in the gap, and the product life up to the valve block can be extended. And the flow control valve 1
Is used for an engine speed control valve that controls the amount of intake air that bypasses the throttle valve of the engine,
During normal running, the valve 4 is closed, the engine speed is set low, fuel efficiency can be improved, and the problem of speeding up against the driver's intention can be eliminated.

[Modification] In the present embodiment, the housing 3 of the idle speed control valve (ISCV) attached to the outer wall surface of the throttle body is used as the housing containing the valve. A throttle body may be used. Further, the present invention may be applied to other flow control valves and proportional control valves other than the idle rotation speed control valve (ISCV).

[Brief description of the drawings]

FIG. 1A is an explanatory view showing a fully closed state of a flow control valve, and FIG. 1B is an explanatory view showing a half open state of a flow control valve (Example).

FIGS. 2A and 2B are cross-sectional views showing an idle rotation speed control valve (prior art).

FIG. 3A is an explanatory view showing a fully closed state of an idle rotational speed control valve, and FIG. 3B is an explanatory view showing a half open state of the idle rotational speed control valve (prior art).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow control valve 2 Bypass passage 3 Housing 4 Valve 5 Shaft 6 Housing sealing surface 7 Valve seat 9 Central axis

Claims (3)

[Claims] A flow control valve for controlling a flow rate of a fluid flowing through a fluid passage formed in a housing, wherein the valve adjusts an opening area of the fluid passage, and the valve minimizes an opening area of the fluid passage. A flow control valve provided with a housing seal surface overlapping with a seat portion of the valve, wherein an operation center axis of the valve and a center axis of the housing seal surface are shifted from each other. 2. The flow control valve according to claim 1, wherein the valve is a rotary valve that swings about an operation center axis of the valve. 3. The flow control valve according to claim 1, wherein the flow control valve is an engine speed control valve that controls an intake air amount that bypasses a throttle valve of an engine.