JP3010935B2 - Idle air flow control system for automotive engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile engine
Regarding dollar air amount control device, especially solenoid mechanism and air
Idle air by combination of pressure servo mechanism
It relates to controlling a quantity control valve.

[0002]

2. Description of the Related Art An idle air amount control valve for an automobile engine known from Japanese Patent Application Laid-Open No. 3-290056 discloses a rod-shaped shaft on which a valve is mounted, which is advanced and retracted in an axial direction by a driving force source such as an electromagnetic solenoid. The valve is opened and closed to control the flow rate of the fluid. The idle air flow control valve has a pneumatic servo mechanism such that both shafts perform the same operation via the diaphragm instead of the rod-shaped shaft with the valve attached and the shaft that moves forward and backward by the electromagnetic solenoid. I have. Although there is a minute gap in the shaft bearing, the servo mechanism easily causes the shaft to vibrate and tilt in the direction perpendicular to the shaft due to engine vibration, and causes the flow characteristics to deteriorate. The spring material is pressed and the frictional force is used to limit the movement of the shaft in the direction perpendicular to the axis.

[0003]

In the prior art, a metal spring material is used for a sliding member for restricting movement of a rod-shaped shaft to which a valve is attached in a direction perpendicular to the axis, and the metal shaft is used for the shaft. Because the spring material was pressed, the area of the sliding part that generates frictional force was very small and the surface pressure increased, and the sliding part of the shaft progressed quickly, causing scratches due to wear. The frictional force changes as the spring material catches on the wear scar,
There is a problem that vibration in the direction perpendicular to the axis cannot be suppressed.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, a material of a sliding member which generates a frictional force which restricts the movement of a rod-shaped shaft on which a valve is mounted in a direction perpendicular to the axis is provided. An elastomer such as rubber or plastic was used.

[0005]

[Effects] Elastomers such as rubber and plastic have a lower elastic modulus than metals and can be made into any shape by injection molding using a mold, so that they gradually deform from the contact part to the base. Can be made in any shape. As a result, the contact portion between the shaft and the sliding member can be brought into surface contact, a stable frictional force can be obtained, and vibration of the shaft in a direction perpendicular to the axis can be suppressed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below. This embodiment is an example of an idle air amount control valve of an automobile engine having a pneumatic servo mechanism. The idle air amount control valve is located in a flow path that bypasses the upstream and downstream of a main flow path in which a throttle valve that controls the intake air amount of the engine is provided. A valve of the idle air amount control valve is opened and closed by a signal from a control unit for controlling an operation state, and the idle speed is controlled.

The main structure of the idle air amount control valve will be described with reference to FIG. The passage 2 of the valve case 1 communicates downstream of the throttle valve, and the passage 3 communicates upstream of the throttle valve. A central shaft 5 formed at the center of the valve 4 is held by a bearing 6 fixed to the valve case 1 so as to be movable in the axial direction. The valve 4 can completely close the space between the passage 2 and the passage 3 by contacting the valve seat portion 1a inside the valve case 1. A caulking member 26 is fixed to the central shaft 5, and the plate 8 and the plate 9 are caulked and fixed by the caulking member 26, and the inner ring portion of the diaphragm 10 is interposed between the plate 8 and the plate 9. It is attached. Plates 8 and 9 are provided with orifices 11 leading to passage 3. The outer ring of the diaphragm 10 is sandwiched between the valve case 1 and the solenoid case 12. The bearing plate 29 is fixed to the solenoid case 12 and is a cylindrical portion at the center thereof.
Is receiving. A solenoid assembly 16 is housed and fixed in the solenoid case 12. The solenoid assembly 16
A plunger 14 that can move in the same direction as the center axis 5, a core 15 that sucks the plunger 14, and an annular coil 2 formed so as to surround the core 15 and the plunger 14.
8, a shaft 17 fixed to the plunger 14,
It comprises a spring 18 for pushing the plunger 14 toward the valve 4 and an adjusting screw 19 for adjusting the set load of the spring 18 and supporting the shaft 17 in the center bearing hole. Have been. A control valve 21 made of rubber is fixed to the plunger 14. Furthermore, bearing plate 2
A spring 13 for pushing the plunger 14 toward the adjusting screw 19 is provided between the plunger 9 and the plunger 14.

In this configuration, the solenoid is a linear solenoid, and the displacement has a linear property with respect to the current. As the current increases, the plunger 14 moves toward the core 15 and the control valve 21 moves together with the plunger 14, so that the control valve 21 is separated from the end of the central shaft 5. Then passage 2
Is introduced into the chamber 23 between the diaphragm 10 and the solenoid case 12 through the hole 22, the passage 31 in the central shaft 5 and the orifice 32 at the tip. Although the negative pressure is slightly released through the orifice 11, the amount of the introduced negative pressure is large, so that the pressure in the chamber 23 becomes lower than the pressure in the passage 3, and the pressure difference between the passage 3 and the diaphragm 10 causes the diaphragm 10 to move to the left in the drawing. To open the valve 4 via the central shaft 5. The balance between the negative pressure leaking from the orifice 11 and the negative pressure introduced from the control valve 21 causes the orifice 32 at the tip of the central shaft 5 to move in close contact with the control valve 21. When the orifice 32 closes, the pressure tries to balance through the orifice 11. At the same time, the diaphragm 10 is displaced to the right in the drawing, the orifice 32 is opened, and the negative pressure of the passage 2 is again introduced into the chamber 23, and the diaphragm 10
Moves to the left of the drawing. Thus, the valve 4 moves following the moved position of the plunger 14 and is held at that position.

The springs 13, 18, and 30 have an effect of preventing the valve 4 and the control valve 21 from moving due to vibration or the like, and an adjusting screw 19 provided at the rear end of the shaft 17 movable together with the plunger 14 is provided with a spring. 18 has the effect of adjusting the variation in the load on production and assembly.

In this apparatus, the valve 4 is fully closed when no power is supplied, so that the valve 4 is closed even if the diaphragm 10 is broken . The valve 4 is not open as long as the co <br/> cement roll valve 21 be clogged orifice 11 is closed. Therefore, when each part breaks down, there is an effect that the valve 4 is closed.

What is important here is that the center shaft 5 is supported by the bearing 6 and the bearing plate 29 and is urged in the axial direction by the above-mentioned spring 13, 18 or 30, but the pneumatic servo as in this embodiment is used. In the idle air amount control valve having the mechanism, the vibration of the valve 4 and the center shaft 5 in the radial direction cannot be suppressed by itself.

Therefore, in this embodiment, the bush 24 shown in FIGS. 2 to 4 is formed of a fluorine-based rubber and added as a vibration suppressing member. 2 shows a front view, FIG. 3 shows a side view, and FIG. 4 shows a perspective view. The bush 24 has eight convex portions 24a.
, And each projection 24a is inclined in the same circumferential direction, and is inclined by about 30 ° with respect to the normal direction.

In FIG. 1, a bush 24 is pressed against a plate 27 fixed to the valve case 1 by a washer 25, and the washer 25 is fixed by bending a claw of the plate 27. Eight convex portions 24a of the bush 24
Presses the outer periphery of the central shaft 5, thereby generating a frictional force when the central shaft 5 slides, and the frictional force attenuates the vibration generated on the central shaft 5.

In this embodiment, the material of the bush 24 is made of fluorine rubber, but the surface may be coated with Teflon. Thereby, it is possible to prevent the smooth sliding of the sliding portion from being hindered by the adhesiveness specific to rubber. The same effect can be obtained by using a low-adhesive or non-adhesive fluorine-based rubber. Further, a Teflon-based resin may be used.

FIGS. 5 and 6 show a second embodiment of the present invention. FIG. 5 is a front view and FIG. 6 is a longitudinal sectional view. After the bush 24 and the washer 25 are directly baked, the center shaft 5
The assembly process of the idle air amount control valve can be simplified.

[0016] 7 to 8 show a third embodiment of the present invention, FIG. 7 is a front view, FIG. 8 is a longitudinal sectional view. As shown in FIG. 8, a plurality of convex portions 24a in contact with the central shaft 5 are arranged in a plurality of rows in the sliding direction of the central shaft 5, and the convex portions 24a are inclined in the sliding direction of the central shaft 5 to generate a frictional force. and, Ru dampen the vibrations this frictional force is generated to the central axis 5.

In addition, as shown in FIG.
A plurality of recesses 24b are inserted, and the size of the inclination of the convex portions 24a is large.
By adjusting the friction, you can change the friction force
You.

[0018]

According to the present invention, the amount of idle air is controlled.
In order to prevent vibration of the hollow shaft,
The member that pushes and causes frictional force is caught on this hollow shaft
Solves the problem that the control of idle air volume becomes unstable
It can be turned off and maintains an appropriate idle speed even after long-term use
A possible idle air amount control device was obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an idle air amount control valve using a first embodiment of the present invention.

FIG. 2 is a front view of the first embodiment of the present invention.

FIG. 3 is a side view of the first embodiment of the present invention.

FIG. 4 is a perspective view of the first embodiment of the present invention.

FIG. 5 is a front view of a second embodiment of the present invention.

FIG. 6 is a sectional view of a second embodiment of the present invention.

FIG. 7 is a front view of a third embodiment of the present invention.

FIG. 8 is a sectional view of a third embodiment of the present invention.

[Explanation of symbols]

5 ... Center axis, 24 ... Bushing, 24a ... Protrusion, 24b ...
Notch, 25 ... washer, 33 ... holder.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model 1-42928 (JP, U) Japanese Utility Model 61-119691 (JP, U) Japanese Utility Model 55-31291 (JP, Y2) (58) Field (Int.Cl. ⁷ , DB name) F02M 69/32 F16F 15/02 G05D 19/02

Claims (4)

(57) [Claims] An annular diaphragm whose outer periphery is sandwiched between an open end of a cylindrical valve case and a solenoid mechanism, and one end of a hollow shaft is provided at the center of the diaphragm in the solenoid mechanism. It is supported by a bearing plate, and the other end is guided by a bearing provided inside the cylindrical valve case, and is formed in the cylindrical valve case between the diaphragm and the inside of the cylindrical valve case. An air flow control unit is formed by the valve seat provided and a valve fixed to the hollow shaft. The cylindrical valve case has an air intake port on the diaphragm side with the air flow control unit interposed therebetween. The air discharge port is formed on the side of the diaphragm, and the air discharge port communicates with the space of the diaphragm on the solenoid mechanism side by the hollow shaft. Ri, the solenoid mechanism side end opening portion of the hollow shaft are closed by the control valve formed at the tip of the plunger of the solenoid mechanism,
The plunger is urged toward the diaphragm by a spring, and the hollow shaft is urged toward the plunger by another spring.When the solenoid of the solenoid mechanism is not energized, the plunger is disengaged. A force in a direction of pressing the valve against the valve seat against a force of a spring is configured to be applied, and the cylindrical valve case is provided at a position between the diaphragm and the valve. A plate having a hollow shaft passing through the center is fixed, and an elastomer bush is fixed to the plate. The bush presses the outer periphery of the hollow shaft, and when the hollow shaft advances and retreats in the axial direction. A plurality of elastomeric protrusions that generate frictional force between the hollow shaft and the hollow shaft are formed toward the center of the idle space of the automobile engine. The amount control device. 2. The idle air amount control device for an automobile engine according to claim 1, wherein said bush is formed of fluorine-based rubber. 3. The idle air amount control device for an automobile engine according to claim 1, wherein a surface of said bush is coated with Teflon. 4. The projection formed on the bush is inclined in a certain direction before being assembled.
Or the idle air amount control device for an automobile engine according to 2.