JP2000018399A - Flow control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow control valve capable of reducing leakage from the valve. SOLUTION: An adjusting screw 25 is provided with a flange part 35, and a wave washer 55 with a sufficiently stronger energizing force than the energizing force of a spring 27 is placed between the flange part 35 and a housing 11. Therefore, when an ISC valve (flow control valve) 10 is adjusted, the adjusting screw 25 is pressed in the opposite direction to screwing direction so as to absorb a backlash at a screw part 36 to prevent helical motion and inclination of the adjusting screw 25. Therefore, the interior wall of a shaft support hole 39a and one end of a shaft 30 are prevented from sticking together and tilting of the shaft 30 and a valve portion 41 is prevented whereby valve leakage can be reduced.

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, and more particularly, to a flow control valve provided with a bypass passage for bypassing a throttle valve of an internal combustion engine (hereinafter referred to as an "internal combustion engine"). The present invention relates to a flow control valve suitable for performing

[0002]

2. Description of the Related Art Conventionally, in an engine equipped with an electronically controlled fuel injection device (hereinafter, "fuel injection device" is referred to as an injector), a bypass passage for bypassing a throttle valve is provided, and an air flow rate in this bypass passage is provided. (Hereinafter, an "idle speed control valve" is referred to as an ISC valve) is known. As such an ISC valve, for example, JP-A-8-326915
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. H10-209, an apparatus using an electromagnetic valve has been proposed.

[0003]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 8-32691
In the ISC valve disclosed in Japanese Patent Laid-Open Publication No. 5 (1995) -2005, when energization of a coil portion of an electromagnetic valve is turned off, a biasing force of a spring urges a valve member as a mover in a valve closing direction to close a bypass passage, When power is supplied to the portion, the valve member is sucked against the urging force of the spring to open the bypass passage. An adjusting screw is screwed into the housing in which the bypass passage is formed, a shaft supporting the valve member is slidably supported by the adjusting screw, and the adjusting screw is screwed into the housing by changing the screwing amount of the adjusting screw. The lift position of the valve member can be adjusted by adjusting the urging force of the valve member.

However, in the above-mentioned conventional ISC valve, the adjusting screw serves as both a bearing means for the shaft and a means for adjusting the urging force of the spring. Therefore, when adjusting the ISC valve, the screw portion of the adjusting screw is required. Helical movement, that is, the rattling of the thread,
The adjusting screw is inclined by the biasing force of the spring, and the sliding portion between the adjusting screw and the shaft is twisted, the shaft and the valve member are inclined, and the contact portion of the valve member and the valve seat formed on the inner wall of the housing. A gap may be formed between them, and so-called valve leakage may occur. Since the valve leakage is an uncontrollable flow rate, there is a problem that if the valve leakage is large, the idle speed of the engine cannot be set low, the fuel consumption increases, and the exhaust emission deteriorates.

[0005] Therefore, (a) reducing the play of the screw of the adjusting screw to reduce the helical movement of the adjusting screw, and (b) increasing the clearance of the sliding portion between the adjusting screw and the shaft. ,
It is conceivable to prevent the sliding portion between the adjusting screw and the shaft from being twisted. However, since the adjusting screw's thread is coated with a fixing agent for fixing the adjusting screw to the housing, (a) There has been a problem that the agent drops off, making it difficult to fix the adjusting screw to the housing, and causing leakage.
(B) If the clearance of the sliding portion between the adjusting screw and the shaft is increased, the characteristics of the ISC valve deteriorate, and it is difficult to control the air flow rate in the bypass passage. The present invention has been made to solve such a problem, and has as its object to provide a flow control valve capable of reducing valve leakage.

[0006]

According to the flow control valve of the present invention, the holding means fixed to the housing biases the valve seat in a direction in which the valve member is separated from the valve seat. The first urging means is capable of adjusting the urging force of the first urging means, and the second urging means provided between the holding means and the housing prevents the holding means from tilting. I do.
Therefore, when adjusting the flow control valve, the inclination of the holding member can be prevented, so that the inclination of the valve member can be prevented. Therefore, it is possible to prevent a gap from being formed between the contact portion of the valve member and the valve seat portion, so that so-called valve leakage can be reduced.

According to the flow control valve according to the second aspect of the present invention, since the holding means has a flange, the flow control can be performed by disposing the second urging means between the flange and the housing. Tilt of the valve member during valve adjustment can be easily prevented. Therefore, valve leakage can be easily reduced.

According to the flow control valve according to the third aspect of the present invention, since the second urging means has an annular shape, the urging force of the second urging means is reduced by the urging force of the first urging means. By making it larger, it is possible to prevent the inclination of the valve member at the time of adjusting the flow control valve with a simple configuration. Therefore, valve leakage can be reduced with a simple configuration.

According to the flow control valve of the fourth aspect of the present invention, since the second urging means has a dish shape, the urging force of the second urging means is smaller than the urging force of the first urging means. The inclination of the valve member at the time of adjusting the flow control valve can be prevented with a simple configuration by increasing the height. Therefore, valve leakage can be reduced with a simple configuration.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 to 5 show a first embodiment in which the flow control valve of the present invention is applied to an ISC valve. As shown in FIG.
The ISC valve 10 is used for controlling an engine idle speed, and controls an air flow rate in a bypass passage 2 that bypasses the throttle valve 1 during idling. The bypass passage 2 has an inlet 2 a connected to the intake duct 3 and an outlet 2 b connected to the surge tank 4. The air whose flow rate is controlled by the ISC valve 10 through the intake duct is supplied to an engine (not shown) through the surge tank 4.

As shown in FIG. 1, an air passage 60 is formed in the housing 11 of the ISC valve 10. The air passage 60 has a U-shaped cross section, and has an inlet 61 and an outlet 62. The inflow port 61 communicates with the inlet side 2a of the bypass passage 2 shown in FIG.
Is connected to the outlet side 2b of the bypass passage 2 shown in FIG. On the inner wall of the housing 11 between the inflow port 61 and the outflow port 62 of the air passage 60, there is formed a valve seat 11a to which a valve section 41 as a valve member to be described later can contact. Housing 1
1 accommodates a valve portion 41, a bellows 40, an electromagnetic actuator 20, and the like.

The valve portion 41 is for opening and closing the air passage 60, and is disposed closer to the outlet port 62 than the valve seat portion 11a of the air passage 60, and can be seated on the valve seat portion 11a. A contact portion 41a is provided. The valve portion 41 includes a valve portion 41.
Is supported by a shaft 30 that penetrates through the center portion, and is movable in the axial direction together with the shaft 30.

One end of the shaft 30 slides on an inner wall forming a shaft support hole 39a of the adjusting screw 25, which will be described later, and the other end of the shaft 30
It is supported by a leaf spring 31 for centering zero. The outer peripheral portion of the leaf spring 31 is sandwiched between a bellows 40 and a magnetic plate 44 of the electromagnetic actuator 20 described later. The shaft 30 reciprocates together with the movable core 26 and the valve portion 41 of the electromagnetic actuator 20 described later.

The bellows 40 is provided integrally with the valve portion 41, and the bellows portion 4 connected to the outlet 62 side of the valve portion 41 is provided.
2 and the bellows part 42 and the bellows part 42
And a flange portion 43 having a larger diameter than the flange portion 43. The bellows 40 is sandwiched between the magnetic plate 44 and the step portion 11 b formed on the inner peripheral wall of the housing 11 together with the leaf spring 31 on the outer periphery of the flange portion 43. The inside of the bellows 40 and the inflow side of the air passage 60 communicate with each other through a through hole 41 b provided in the valve portion 41. Therefore, the pressure difference between the inside of the bellows 40 and the inflow side of the air passage 60 is canceled, so that the force applied to the valve portion 41 by the pressure difference between the upstream and downstream of the air flow can be canceled.

The adjusting screw 25 is screwed to the housing 11 and slidably supports one end of the shaft 30. As shown in FIGS. 3 and 4, the adjusting screw 25 includes a large-diameter flange portion 35, a screw portion 36, a cylindrical portion 37, a step portion 38,
And a cylindrical tip portion 39, each of which is formed continuously in the above order. For example, a pentagonal hole 35a is formed at an end of the flange portion 35, and the adjusting screw 25 is formed by a special tool such as a pentagonal wrench.
Can be screwed into the housing 11. Hole 3
5a extends from the end of the flange portion 35 to the inside of the screw portion 36. The screw portion 36 has a smaller diameter than the flange portion 35, and is coated with a fixing agent (not shown) for fixing the adjusting screw 25. Tube part 37
Is smaller in diameter than the threaded portion 36 and is continuous with the tube tip portion 39 via the step portion 38. The tube tip 39 has a smaller diameter than the tube 38, and the tube tip 39 has a shaft support hole 39 for slidably supporting one end of the shaft 30.
The shaft support hole 39a extends from the tube tip 39 to the inside of the tube 37. A clearance is formed between the inner wall of the shaft support hole 39 a and one end of the shaft 30 so that one end of the shaft 30 can slide. By changing the screwing amount of the adjusting screw 25, the spring 2
7 can be controlled, and the lift position of the movable core 26 can be controlled. Here, the adjusting screw 25 constitutes a holding unit.

As shown in FIG. 1, the step 38 and the valve 41
A spring 27 as first urging means is disposed between the first and second springs. The spring 27 is connected to the contact portion 4 of the valve portion 41.
1a is separated from the valve seat 11a, that is, the valve 4
1 urges the valve portion 41 in the opening direction.

A wave washer 55 is disposed between the flange 35 and the housing 11 as second urging means. The wave washer 55 urges the adjusting screw 25 to the left in FIG. 1, that is, the direction opposite to the screwing direction of the adjusting screw 25. As shown in FIG. 5, the wave washer 55 has an annular shape, and has an outer peripheral portion 55a, an inner peripheral portion 55b, and a wave surface 55c. The outer diameter of the outer peripheral portion 55a is smaller than the outer diameter of the flange portion 35. The inner diameter of the inner peripheral portion 55b is larger than the outer diameter of the screw portion 36. The wave surface 55c is formed in a wave surface shape. The urging force of the wave washer 55 is the spring 2
7 is set larger than the urging force.

The direct-acting electromagnetic actuator 20 is provided on the inner periphery of the bobbin 22 and the coil portion 23 composed of a cylindrical yoke 21, a coil housed in a magnetic plate 44 and wound around the bobbin 22. Fixed core 2
4. A movable core 26 disposed reciprocally with respect to the fixed core 24, a spring 28 disposed between the fixed core 24 and the movable core 26, and a movable core 26 provided on one axial side of the bobbin 22. It consists of a disk-shaped plate 29. The magnetic plate 44, the yoke 21, the fixed core 24, and the plate 29 as the stator are each formed of a magnetic material such as iron, and form a fixed magnetic circuit.

The movable core 26 is formed of a magnetic material such as iron, and is press-fitted and fixed to a shaft 30, which will be described later, and inserted into the hollow portion of the yoke 21. The movable core 26 is urged by a spring 28 in a direction away from the fixed core 24, that is, in a direction in which the valve portion 41 closes the air passage 60. Since the urging force of the spring 28 is set to be greater than the urging force of the spring 27, the contact portion 41a of the valve portion 41 comes into contact with the valve seat portion 11a when the power supply to the coil portion 23 from the current supply means (not shown) is turned off. As shown in FIG. 1, the air passage 60 is closed. Also, the screwing amount of the adjusting screw 25 is changed to change the spring 27.
, The lift position of the movable core 26 can be controlled.

A current supply means (not shown) supplies
When power is supplied to the movable core 26, the magnetic force generated in the coil portion 23 against the urging force of the spring 28
Is attracted to the fixed core 24 side. A current is supplied to the coil unit 23 from a terminal 51 molded in the connector 50.

Next, an assembling method and an adjusting method of the ISC valve 10 having the above configuration will be described. (1) Valve portion 41, bellows 40, leaf spring 31, movable core 2
6 is inserted into the shaft 30 and assembled by press fitting. (2) Valve portion 41, bellows 40, leaf spring 31, movable core 2
6 is housed in the housing 11,
Press in the magnetic plate 44. (3) The yoke 21, bobbin 22, coil portion 23, fixed core 24, spring 28, plate 29, connector 50 and terminal 51 are connected to the movable core 26 in the housing 11.
Housed on the side.

(4) A provisional spring is inserted into one end of the shaft 30 on the valve portion 41 side, provisional assembly is performed using a provisional adjusting screw, and provisional mounting is performed by measuring provisional characteristics. Select a spring 27 according to the type of engine. Here, the temporary adjusting screw is equivalent to the adjusting screw 25. (5) Remove the temporary adjusting screw, insert the spring 27 into one end of the shaft 30, and remove the screw 3
The wave washer 55 is mounted on the adjusting screw 25 having the fixing agent applied to 6, and one end of the shaft 30 is inserted into the shaft support hole 39 a of the adjusting screw 25.

(6) This characteristic is measured while screwing the adjusting screw 25 into the housing 11 using a special tool such as a pentagon wrench, and the urging force of the spring 27 is determined. At this time, since the urging force of the wave washer 55 is sufficiently stronger than the urging force of the spring 27, the adjusting screw 25 is pressed in the left direction in FIG. 1, that is, in the direction opposite to the screwing direction. For this reason, the backlash of the screw portion 36 is absorbed to prevent the adjusting screw 25 from spiraling and tilting, and the inner wall of the shaft support hole 39a and one end of the shaft 30 are prevented from being twisted. 30 and the valve portion 41 can be prevented from tilting. Therefore, a so-called valve leak, in which a gap is formed between the contact portion 41a of the valve portion 41 and the valve seat portion 11a, can be reduced.

Further, by selecting the spring 27 according to the type of the engine to be mounted, the ISC valve 10 can be easily provided.
Can be adjusted to accommodate various types of engines.

Next, the operation of the ISC valve 10 assembled and adjusted according to the above steps (1) to (6) will be described. (1) When the power supply to the coil unit 23 is turned off, as shown in FIG.
The contact portion 41a of the valve portion 41 contacts the valve seat portion 11a, and the air passage 60 is closed.

(2) When the power supply from the current supply means (not shown) to the coil unit 23 is turned on, the magnetic plate 4
4. A magnetic circuit is formed by the yoke 21, the fixed core 24, the plate 29, and the movable core 26, and an attractive force is generated between the fixed core 24 and the movable core 26. By this attraction force, the movable core 26 is attracted toward the fixed core 24 to a position where the biasing forces of the spring 27, the spring 28, and the leaf spring 31 are balanced, and the shaft 30 and the valve portion 41 move in the axial direction together with the movable core 26. Then, the contact portion 41a of the valve portion 41 is separated from the valve seat portion 11a, and air flows from the inlet 61 to the outlet 62 in the air passage 60. I mentioned earlier
By controlling the amount of current supplied to the coil unit 23 by the current supply unit when the power supply to the coil unit 23 is turned on in (2), the lift position of the movable core 26 is defined, and the intake flow rate in the air passage 60 is controlled. be able to.

Next, a comparative example in which the adjusting screw 25 of the first embodiment is not provided with the flange 35 and the wave washer 55 is not provided will be described with reference to FIG. The same components as those in the first embodiment shown in FIG.

In the comparative example, as shown in FIG. 8, the adjusting screw 75 is screwed to the housing 11, and slidably supports one end of the shaft 30. The adjusting screw 75 has a screw portion 76 for screwing to the housing 11, and a shaft support hole 77 for slidably supporting one end of the shaft 30 is formed in the distal end portion. I have. By changing the screwing amount of the adjusting screw 75 and adjusting the biasing force of the spring 27, the lift position of the valve portion 41 can be adjusted.

However, in the comparative example, the ISC
At the time of adjusting the valve, the adjusting screw 75 is inclined by the helical movement of the screw portion 76, that is, the play of the screw portion 76 and the urging force of the spring 27, and the inner wall of the shaft support hole 77 and one end of the shaft 30. The sliding part with is torn. For this reason, the shaft 30 and the valve portion 41 are tilted, a gap is formed between the contact portion 41a of the valve portion 41 and the valve seat portion 11a, and so-called valve leakage may occur.

(A) reducing the play of the screw portion 76 to reduce the spiral movement of the adjusting screw 75;
(b) It is possible to increase the clearance of the sliding portion between the inner wall of the shaft support hole 77 and one end of the shaft 30 so that the sliding portion is not twisted. However, since a fixing agent for fixing the adjusting screw 75 to the housing 11 is applied to the screw portion 76, (a) when the looseness of the screw portion 76 is reduced, the fixing agent drops off. Therefore, it is difficult to fix the adjusting screw 75 to the housing 11, and there is a possibility that the adjusting screw 75 may leak. (B) If the clearance of the sliding portion between the inner wall of the shaft support hole 77 and one end of the shaft 30 is increased, the characteristics of the ISC valve deteriorate, making it difficult to control the air flow rate in the bypass passage. Become.

On the other hand, in the first embodiment, the adjusting screw 25 is provided with a flange portion 35, and a wave washer 55 having a sufficient biasing force than the spring 27 is disposed between the flange portion 35 and the housing 11. Has been established. For this reason, when adjusting the ISC valve 10, the adjusting screw 25 is pressed in the direction opposite to the screwing direction, and the play of the screw portion 36 is absorbed, thereby preventing the adjusting screw 25 from spiraling and tilting. Therefore, the inner wall of the shaft support hole 39a and the shaft 30
Of the shaft 30 and the valve portion 41 can be prevented from tilting, and valve leakage can be reduced.

Further, in the first embodiment, the ISC valve 10 can be easily adjusted by selecting the spring 27 according to the type of the engine to be mounted, and it is possible to cope with various types of engines. it can. Furthermore,
In the first embodiment, since assembly can be performed easily, the number of assembly steps during manufacturing can be reduced.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
And FIG. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the wave washer 55 of the first embodiment shown in FIG. 5 is changed to a dish shape. As shown in FIG. 7, the dish washer 65 as the second urging means is dish-shaped, and has an outer peripheral portion 65a, an inner peripheral portion 65b, and a conical surface 65c. As shown in FIG. 6, the outer diameter of the outer peripheral portion 65a is smaller than the outer diameter of the flange portion 35, and the inner diameter of the inner peripheral portion 65b is larger than the outer diameter of the screw portion 36. The urging force of the dish washer 65 is set to be larger than the urging force of the spring 27.

Also in the second embodiment, the adjusting screw 25 is provided with a flange 35,
A dish washer 65 having a sufficiently stronger urging force than the urging force is disposed between the flange portion 35 and the housing 11. Therefore, when adjusting the ISC valve, the adjusting screw 25 is pressed in the direction opposite to the screwing direction, and
The adjusting screw 25 absorbs rattling
Prevents spiral movement and tilting. Therefore, the inner wall of the shaft support hole 39a and one end of the shaft 30 can be prevented from being twisted, the shaft 30 and the valve portion 41 can be prevented from tilting, and valve leakage can be reduced.

In the embodiments of the present invention described above, an example in which the present invention is applied to the ISC valve for adjusting the intake air flow rate in the bypass passage 2 during idling operation has been described. It is possible to apply the present invention to a flow control valve that maintains a predetermined amount of fluid flow without closing the fluid passage even in the state where the fluid flow path is closed.

[Brief description of the drawings]

FIG. 1 is a first diagram in which a flow control valve of the present invention is applied to an ISC valve.
It is sectional drawing which shows an Example.

FIG. 2 is a schematic diagram showing a state in which an ISC valve according to a first embodiment of the present invention is provided in a bypass passage.

FIG. 3 is a perspective view showing an adjusting screw according to the first embodiment of the present invention.

FIG. 4 is a side view showing the adjusting screw according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a wave washer according to the first embodiment of the present invention.

FIG. 6 shows a second embodiment in which the flow control valve of the present invention is applied to an ISC valve.
It is sectional drawing which shows an Example.

FIG. 7 is a perspective view showing a dish washer according to a second embodiment of the present invention.

FIG. 8 is a sectional view showing an ISC valve of a comparative example.

[Explanation of symbols]

 Reference Signs List 2 bypass passage 10 ISC valve (flow control valve) 11 housing 11a valve seat 20 electromagnetic actuator 21 yoke 22 bobbin 23 coil unit 24 fixed core 25 adjusting screw 26 movable core 27 spring (first biasing means) 28 spring 29 Plate 30 Shaft 35 Flange part 36 Screw part 39a Shaft support hole 40 Bellows 41 Valve part (valve member) 41a Contact part 44 Magnetic plate 55 Wave washer (second urging means) 60 Air passage 65 Dish washer (second) Biasing means)

Claims (4)

[Claims] A housing provided with a valve seat on an inner wall forming a fluid passage; a fluid passage closed by sitting on the valve seat, and being separated from the valve seat to form the fluid passage. An opening valve member; first urging means for urging the valve member in a direction in which the valve member separates from the valve seat; and holding the first urging means fixed to the housing. Holding means capable of adjusting the urging force of the first urging means; and second urging means provided between the holding means and the housing to prevent the holding means from tilting. A flow control valve characterized in that: 2. The flow control valve according to claim 1, wherein said holding means has a flange portion. 3. The flow control valve according to claim 1, wherein the second urging means has an annular shape. 4. The flow control valve according to claim 1, wherein the second urging means has a dish shape.