JPH01331A - Fluid control valve for controlling idling speed of internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a fluid valve used in a step motor type idle speed control valve (S/MISCV) of an engine. Regarding the structure of the stop.

[Conventional technology]

In modern engines, in order to secure a predetermined amount of intake air and obtain a predetermined idle rotation speed during idling operation,
It is known that a bypass passage is formed by bypassing a throttle valve in an intake passage, and a step motor type idle speed control valve (S/MISCV) is provided in this bypass passage. .

This will be explained based on FIGS. 8 to 10.

Figure 8 shows the intake system of the engine, where the air taken in from the air cleaner 1 is measured by the air flow meter 2, passed through the throttle valve 3 and S/M・l5CV4, and then led to the surge tank 5. , is inhaled from Gishu 6 to Betsuma 7. In the branch guard 6, the injector 8 injects fuel corresponding to the amount of air measured by the air flow meter 2, and mixes this fuel with the air to create a mixed gas.
This mixed gas is supplied to interstage 1.

The S/M 15CV4 installed in the bypass passage 9 that bypasses the throttle valve 3 bypasses the valve by increasing or decreasing the passage area of the valve part in accordance with signals from the computer 10h1 such as the engine rotation speed at idle. The amount of air is adjusted to achieve a predetermined idle speed.

As shown in FIG. 9, the S/M-ISCV4 uses a step motor 11 as a drive unit, and the rotational movement of a rotor 13 rotated by a fixed coil 12 is controlled by a bolt (valve shaft 14) and a nut (rotation). 13), the structure is such that the valve shaft 14 is converted into an axial reciprocating motion. A profile valve body 15 is integrally fixed to the tip of the valve shaft 14, and by reciprocating the valve body 15 in the axial direction, the opening area with respect to the valve seat 17 formed in the valve housing 16 can be changed. is now possible.

In such a (& construction), the rotation of the rotor 13, which acts as a nut and is rotated by the step motor 11, is
If the valve shaft 14 is caused to rotate without the bolt action, the valve shaft 14 will no longer reciprocate in the axial direction, so it is necessary to stop the valve shaft 14 from rotating.

Conventionally, as shown in FIG. 10, the valve @ 14 is made into a slit-shaped cross section, and the insertion hole 19 of the bearing member 18 that supports the valve shaft 14 is made into a 0-shaped hole. The valve shaft 14 is prevented from rotating by inserting the shaft 14 into the insertion hole 19 of the bearing member 18, which has a cross-sectional shape. The valve stem 14 is prevented from rotating by having a shape other than circular.

[Problem that the invention seeks to solve]

However, in such a rotation stopper structure, the cross-sectional shape of the valve stem 14 and the insertion hole 19 of the bearing member 18 are both irregularly shaped, so the shape is complicated and requires time and effort to process, making it impossible to use standard bearings. Certain things lead to increased costs. Further, there are problems such as poor workability when assembling the valve shaft 14 to the bearing member 18 and a decrease in the strength of the valve shaft 14.

Furthermore, the valve @ 14 and the bearing member 18 inevitably move relative to each other when the valve body 15 is operated, and this sliding surface wears out and the resistance to activity increases. Since the initial output of the motor 11 must be set, the step motor 11 has been forced to be larger.

In addition, a gap is required for the valve stem 14 and the bearing part (No. 18) to move relatively once, and this gap causes backlash in the circumferential direction and the Plij direction, so a certain amount of mass is required. The movable parts consisting of the valve stem 14 and the valve body 15 move when subjected to engine vibrations, and this rattle increases due to wear, further increasing the movement, resulting in this vicious cycle. By repeating this, the anti-rotation capability is significantly reduced, which causes the problem that the hysteresis of the flow characteristics increases when the operation of the uJ drive section is reversed.

In order to prevent the movable part from wobbling in the axial direction, a spring 20 is incorporated that presses the movable part in one direction with a set load equal to or greater than the short time of the movable part x the camera resistance acceleration (G). ,
Spring 20 results in an increase in parts.

In addition, in order to reduce the resistance caused by the 1st habit,
Methods such as pouring PS resin, oil-impregnated metal, or Teflon coating have also been adopted, but such structures are costly because they use expensive materials and require precision machining.

The present invention provides a fluid control valve for controlling the idling rotational speed of an internal combustion engine that is non-sliding, does not cause looseness in the circumferential direction and radial direction, has a simple structure, and has a safe rotation stop mechanism. Write the purpose.

(Means for solving the problem) In the present invention, in the fluid control valve as described above,
A thin plate spring member is fixed to the housing, and a valve body or a valve shaft is attached to the thin plate spring member, and the valve body can freely move in a straight direction by elastic deformation of the thin plate spring member, and Waiting refers to being restrained from being rotated in the rotational direction by being fixed to the spring member.

[Effect]

According to the configuration of the present invention, the valve body is movable in the straight direction due to elastic deformation of the thin plate spring member, and rotation in the rotational direction is restrained by being fixed to the temporary spring member. It prevents rotation while allowing movement. Therefore, there are no sliding parts and no looseness occurs in the circumferential direction and the radial direction. Furthermore, since the thin plate spring member provides a biasing force to eliminate axial play by its spring action, this thin plate spring member alone serves both as a rotation stopper and as the open surface of a conventional spring, reducing the number of parts. Furthermore, since variations in the BIN spring member can be corrected in parts when it is attached to the housing, high accuracy of the valve body and thin plate spring member is not required, and machining is easy.

〔Example〕

The present invention will be explained below based on a first embodiment shown in FIGS. 1 to 3.

FIG. 1 is a sectional view of the S/MiSCV, and 30 is a housing. The housing 30 is constructed by connecting a motor housing 31 and a valve housing 32 with screws 33.

A step motor 11 is attached to the motor housing 31 as a drive unit, as in the conventional case, and a fixed coil 12 drives a rotor 13 to rotate.

The rotor 13 has both ends facing away from the motor housing 31.
It is rotatably supported by bearings 34a and 34b.

A valve shaft 14 is protruded from one end of the rotor 13, and a male threaded portion 35 is formed at the tip of the valve shaft 14.

A profile valve body 15 is attached to the tip of the valve shaft 14. In the case of this embodiment, the valve body 15 leaks through a fitting shaft portion 36 extending in the axial direction, and a female threaded hole 37 is provided in the fitting shaft portion 36.
It is formed. The male threaded portion 35 of the valve shaft 14 is screwed into this female threaded hole 37, so that the valve body 15 is screwed into the female threaded hole 37.
and the valve stem 14 are threadedly engaged. For this reason, the bolt (
Due to the relationship between the valve shaft 14> and the nut (valve body 15), when the valve shaft 14, which corresponds to a bolt, rotates, the valve body 15, which corresponds to a nut, reciprocates in the axial direction according to its screw lead angle.

When the valve body 15 moves in the axial direction, the valve housing 32
The opening area of the valve hole 38 is changed by moving toward and away from the valve seat 17 formed in the valve seat 17 .

Note that 39 is a suction port connected to a bypass passage, and 40 is a discharge port connected to a surge tank.

The valve body 15 is supported by the thin plate spring member 45 and is movable in the axial direction, but is prevented from rotating.

As shown in FIG. 2, the thin plate spring member 45 has an approximately circular shape as a whole, has a peripheral fixing 7 flange 45a, and is provided with a holding portion 45b in the center. 45b is integrally connected to the connecting portion 45c extending in a spiral shape. The center holding part 4
51) is opened with a fitting support hole 46, into which the fitting shaft portion 36 of the valve body 15 is fixed by press fitting without sliding.

Note that the fixed flange 45a of the thin plate spring member 45 is
It is held between the abutting surfaces of the motor housing 31 and the valve housing 32, and is kept airtight by an O-ring 47 or the like.

The operation of an embodiment having such a structure will be explained.

When the rotor 13 is rotated by the step motor 11,
The valve stem 14 is also rotated together.

At this time, the valve body 15 does not rotate because the fitting shaft portion 36 is press-fitted into the fitting support hole 46 of the thin plate spring member 45 . Therefore, between the rotated valve shaft 14 and the valve body whose rotation is prevented, the valve body 15 is actuated in the axial direction by the screw rotation action of the male threaded portion 35 and the female threaded hole 37. At this time, the thin plate spring member 45 has a central holding portion 45b connected to a peripheral fixed 7 flange 45a via a spiral connecting portion 45c.
Since the center holding part 45b can be freely elastically deformed in the plate thickness direction, that is, in the axial direction, the valve body 1 supported by the center holding part 45b can be elastically deformed freely.
5 is moved in the axial direction.

Therefore, the opening area of the valve hole 38 of the valve body 15 changes, and the amount of intake air increases by 1111 points.

According to the first embodiment having such a configuration, the valve shaft 14 and the valve body 15 may have a circular cross section, and the thin plate spring member 45
The shape of the fitting support hole 46 is also circular.

Easy to process. Further, since the valve stem 14 has a circular cross section, there is no problem such as a decrease in strength.

Further, the valve body 15 and the thin plate spring member 45 do not have relative force, so that there is no wear and no rattling.

For this reason, it is necessary to set the initial output of the step motor 11 large in consideration of the change in durability due to increased friction.
1M, making it possible to downsize the step motor 11.

Furthermore, since there is no backlash between the valve body 15 and the thin plate spring member 45, a certain amount of mass can be applied to the fitting shaft portion 36.
The rate at which the linear movable section consisting of the valve body 15 vibrates due to engine vibration is reduced, and the problem that occurs when the hysteresis of the flow characteristics increases when the operation of the linear movable section is reversed is also resolved. Ru.

Conventionally, in order to prevent the movable part from wobbling in the axial direction, a spring 20 is incorporated that presses and urges the movable part in one direction with a set load equal to or greater than the weight of the movable part x the vibration resistance acceleration (G). , the spring 20 increases the number of parts by 111J. On the other hand, the temporary spring member 45 of this factory example provides a biasing force to eliminate axial play by its spring action, so this thin plate spring member 45 alone can prevent rotation and perform the function of a conventional spring. can be used in parallel, reducing the number of parts.

The thin plate spring member 45 can be attached to the housing 31.32 of the fixed 7 flange 45a formed around the valve body 15 and the thin plate spring member 4, since variations can be corrected in parts.
It is easy to process without requiring high precision parts.

Note that the present invention is not limited to the first embodiment described above.

That is, FIG. 4 shows a second actual island example of the present invention.

In accordance with FIG. 4, in the second actual example, the shape of the fitting support hole 4G of the thin plate spring member 45 is changed to form teeth on the inner circumference like a tooth washer to strengthen the engagement force with the valve body 15. However, this prevents the valve body 15 from rotating.

In addition to the tooth washer-shaped fitting support hole 46, a thin plate spring member 45 may be insert-molded into a resin valve body and integrated into the valve body, or the valve body and the thin plate spring member may be bonded with adhesive. It may also be something.

Further, FIG. 5 shows a third embodiment of the present invention, in which the front and rear portions of the valve body 15 that are spaced apart in the axial direction are each supported by thin plate spring portions 1J45.45. Since the valve body 15 is supported by the thin plate spring members 45 and 45, the reliability of the support strength is increased and vibrations and the like are further reduced.

Furthermore, FIGS. 6 and 7 show a fourth embodiment of the present invention, in which a strip-shaped thin plate spring member is spirally used as a leaf spring member that prevents the valve body 15 from rotating. Spring 5
0, its inner end is connected to the valve body, and its outer end is fixed to the housing 32. Even with such a spiral spring 50, the same effect as in the first embodiment can be achieved.

〔Effect of the invention〕

As explained above, according to the present invention, the valve body is supported so as to be movable in the straight direction by elastic deformation of the thin plate spring member, and rotation in the rotational direction is restrained by being fixed to the thin plate spring member. is allowed to move in the axial direction, but is prevented from rotating. Therefore, P
There are no moving parts, and there is no backlash in both the circumferential and radial directions.

Furthermore, since the thin plate spring member provides a biasing force to eliminate axial play due to its spring action, this thin plate spring member alone serves both as a rotation stopper and the function of a conventional spring, and the number of parts can be reduced. Furthermore, since the thin plate spring member can correct for variations in the mounting part to the housing, there is no need for high component accuracy of the valve body and the thin plate spring member, and there are advantages such as ease of machining.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view of a fluid control valve, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. FIG. 4 is a perspective view of a valve body, FIG. 4 is a front view of a thin plate spring member showing a second embodiment of the present invention, FIG. 5 is a sectional view of a fluid control valve showing a third embodiment of the present invention, and FIG. 7 and 7 show a fourth embodiment of the present invention, FIG. 6 is a sectional view of the fluid control valve, FIG. 7 is a sectional view taken along line X-X in FIG. 9, and FIGS. The figures show the conventional technology: Fig. 8 is an explanatory diagram of the intake system of the internal combustion gland, Fig. 9 is a sectional view of the fluid control valve, and Fig. 10 is a sectional view taken along line X-X in Fig. 9. It is. 1... Air cleaner, 3... Throttle valve, 4...
・S/M-ISCV, 5...Surge tank, 7...
Opening/opening, 8... Injector, 9... Bypass passage,
11...Step motor, 12...Stator, 13.
...Rotor, 14...Valve stem, 15...Valve body, 17.
... Valve seat, 30... Housing, 31... Motor housing, 32... Valve housing, 35... Male threaded portion, 36... Fitting shaft portion, 37... Female threaded hole, 38...
...Valve hole, 45... Thin plate spring member, 45a... Fixed 7 langes, 45b... Center holding part, 45c... Connecting part, 46... Fitting support hole. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 8 J Figure 9 Itsumugi Bengi Figure 10

Claims (1)

[Scope of Claims] A bypass passage is branched from the intake passage upstream of the throttle valve, and this bypass passage joins the intake passage again downstream of the throttle valve, and intake air is sucked through the bypass passage when the engine is idling. This is an internal combustion engine in which the cross-sectional area of the bypass passage is controlled by a fluid control valve. In a device that controls the flow rate by changing the gap between the body and a valve seat provided in the housing, a thin plate spring member is fixed to the housing, a valve body or a valve shaft is attached to the thin plate spring member, and the valve Idling rotational speed control for an internal combustion engine, characterized in that the body can freely move in a straight direction by elastic deformation of the thin plate spring member, and is restrained from rotating in the rotational direction by being fixed to the thin plate spring member. Fluid control valve for use.