JPS62129538A - Supporting construction for throttle valve - Google Patents

Abstract

PURPOSE:To ensure smooth action of a valve, by supporting both end parts of a throttle shaft to a throttle body through rolling bearings and designing the method of mounting inner and outer rings of each bearing so that the throttle valve is prevented from moving in a thrust direction. CONSTITUTION:A throttle shaft 14 is formed by inserting a throttle valve 12 into a slit 16 to be fixed by stop screws 18, and both ends of the throttle shaft 14 are rotatably supported to a throttle body 10 by ball bearings 20, 22. An adapting part 26 and an adjusting screw thread (adapting part) 30 are adapted to inner rings 20a, 22a of the ball bearings 20, 22 while the ball bearings adapt an outer ring 20b to a body wall surface 10c through a spring (wave washer) 32 and an outer ring 22b directly to the body wall surface 10c. And the both inner rings 20a, 22a are moved approaching each other by tightening the adjusting screw thread 30 screwed to a threaded part 28 of the throttle shaft 14, further tightening force of the screw thread 30 is transmitted to the outer ring 22b through the inner ring 20a.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a support structure for a throttle valve of an internal combustion engine.

[Conventional technology]

Conventionally, as shown in FIG. 2, a throttle valve 12 was attached to a throttle shaft 14, and the throttle shaft 14 was fitted into a throttle body 10. In such a conventional structure, the throttle shaft 14 was able to move in the thrust direction. In order to prevent such movement of the throttle shaft in the thrust direction, FIG. This dust cover is pushed by a spring. Further, in FIG. 5 of the same publication, a ball bearing is press-fitted into only one end of the throttle shaft, and its outer ring is fixed to the throttle body using a fixing plug.

[Problem that the invention seeks to solve]

Although the configuration described in the above-mentioned publication can prevent the throttle shaft from moving in the thrust direction to some extent, a clearance remains inside the ball bearing. Generally, in ball bearings, the clearance in the thrust direction is considerably larger than the clearance in the radial direction, and the inner JI! ! If a resonance phenomenon of the throttle rotating member occurs in the thrust direction under severe vibration conditions of the engine, it will cause significant damage to the internal rolling surface of the ball bearing, causing problems in the opening and closing operations of the throttle valve.

[Means for solving problems]

The support structure for a throttle valve according to the present invention is such that both ends of a throttle shaft to which a throttle valve is attached are supported on a throttle body wall by rolling bearings, and an axis line provided on the throttle shaft is oriented such that the inner rings of these rolling bearings face each other. At the same time, the outer rings of the rolling bearings can engage with engaging parts fixedly provided on the throttle body wall in the axial direction so as to face the abutting parts. a spring is disposed between the outer ring of at least one of the rolling bearings and the corresponding engaging portion, and further, one of the abutting portion and the engaging portion is fastened to the throttle shaft or the throttle body wall. It is characterized in that it is formed as an adjusting screw, and the set load of the spring is adjusted and the set load acts between the inner ring and the outer ring.

〔Example〕

In Figure 1, inside! ! ! A throttle body 10 disposed in the intake system of an engine has an insertion through hole 10a for mounting a throttle shaft 14 orthogonally to the intake cylinder.
and a cylindrical protruding wall 10b for mounting a bearing. The throttle valve 12 is connected to the throttle shaft 14
It is inserted into a slit 16 provided in and fixed with a set screw 18.

The throttle shaft 14 is connected to the throttle body 1 by ball bearings 20 and 22 fitted to both ends thereof.
Supported by 0. In this case, the term "end" does not mean the outermost end, but rather the outside of the intake pipe. In fact, a throttle lever 24 is fixed to the outermost end of the throttle shaft 14, and a return spring (not shown) is engaged with the other end. As is well known, the ball bearings 20 and 22 have inner rings 2Qa and 22a and outer rings 20b and 22b. The inner ring 20a of the ball bearing 20 on the left side in FIG.

This stepped abutment 26 can be formed as an enlarged diameter portion of the throttle shaft 14 or as a spacer that abuts the throttle lever 24 . The inner ring 22a of the right ball bearing 22 is loosely fitted into the throttle shirt l-14 and abuts against an adjustment screw 30 that is fastened to the threaded portion 28 of the throttle shaft 14. Therefore, by tightening the adjustment screw 30, both inner rings 20a are adjusted.

22a are subjected to a force that causes them to approach each other in the axial direction. Therefore, in this case, both optical contact portions 26 and 30 are provided in such a manner that they face each other inwardly.

The outer rings of both ball bearings 20 and 220 are loosely fitted into the inner diameter holes of the cylindrical protruding wall 10b, and the wall surface I of the throttle body 10 is perpendicular to the throttle shaft 14.
They are arranged to sandwich the OC. These wall surfaces 10c face the abutting portions 26, 30 of the throttle shaft 14, respectively, and serve as engaging portions facing outward. A spring 32 is arranged between the outer ring 20b of the left ball bearing 20 and the corresponding wall surface 10C. This spring 32 is formed of a wave washer and has convex portions and concave portions alternately in the circumferential direction. Such a wave washer can be placed in a space with a smaller width than a coil spring and can withstand a large compressive load.

In the above configuration, when the adjustment screw 30 is tightened, the inner rings 20a, 22a of both ball bearings 20, 22 move closer to each other, and the right ball bearing 22 moves closer to each other.
The outer ring 22b of the throttle body 10 contacts the wall surface 10c of the throttle body 10. When it is subsequently tightened, the force of the tightening is transmitted to the outer ring 20b of the left ball bearing 20 via the inner ring 20a. Therefore, the adjusting screw 30 can adjust the set load of the spring 32. This set load acts between the inner ring 20a (22a) and the outer ring 20b (22b), thereby causing the inner ring 20a (22
a) and the outer ring 20b (22b) to maintain the clearance in the thrust direction at zero. spring 3
Adjustment of the set load in step 2 absorbs variations between individual parts, prevents the throttle shaft 14 from moving in the thrust direction, and prevents the ball bearings 20 and 2 from moving in the thrust direction.
This is done to ensure smooth rotation of 2.

FIG. 3 shows an embodiment in which tapered roller bearings 40 and 42 are used instead of the ball bearings 20 and 22 in FIG.
The other configurations are the same as in FIG. 1. FIG. 4 shows yet another embodiment, in which the relationship between the abutting portion and the engaging portion is different from that in FIG. 1. Inner ring 20a of ball bearing 20°22
, 22a is 0.7 mm).
These step portions 10d face outward and face each other.

The engagement portions for the outer rings 2Qb, 22b of the ball bearings 20, 22 consist of a snap ring 44 fitted in an annular groove in the inner diameter portion of the cylindrical protruding wall 10b of the throttle body IO on one side (left side), and on the other side (on the left side). On the (right side), the adjustment screw lOe is similarly fastened to the threaded portion toe of the inner diameter portion of the cylindrical projecting wall 10b. This adjustment screw 46
A spring 32 made of a wave washer is disposed between the ball ring 22 and the outer ring 22b of the ball ring 22. Also in this embodiment, by tightening the adjustment screw 46, the spring 32 pushes the outer ring 22b of the right ball hair ring 22, and the force is transmitted through the inner ring 22a of the right ball hair ring 22 and the throttle shaft 14. It is transmitted to the inner ring 20a of the left ball bearing 20. Therefore, the inner ring 20a of the left ball bearing 20 tries to move to the left, but the outer ring 20a of the ball bearing 20
Since 0b is engaged with the snap ring 44, its movement to the left is restricted, and therefore a predetermined spring force acts between the inner ring 20a and the outer ring 20b. Similarly, the inner ring 22a and outer ring 2 of the ball bearing 22 on the right side are
2b, a predetermined spring force acts between them.

〔Effect of the invention〕

As explained above, according to the present invention, movement of the throttle valve in the thrust direction can be prevented, thereby eliminating galling of the throttle body wall surface by the throttle valve, and furthermore, eliminating backlash inside the bearing, thereby improving the durability of the bearing. will improve. Further, in the present invention, there is no need to press fit the bearing, so assembly and disassembly can be facilitated.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a conventional structure, FIG. 3 is a diagram showing another embodiment, and FIG. 4 is a diagram showing still another embodiment. . lO... Throttle body, 12... Throttle shaft, 20, 22... Ball bearing, 26... Contact portion, 30... Adjustment screw, 32
···spring.

Claims (1)

[Claims] Both ends of the throttle shaft to which the throttle valve is attached are supported on the throttle body wall by rolling bearings, and the inner rings of the rolling bearings are brought into contact with axial contact portions provided on the throttle shaft in opposing directions. , the outer rings of both of the rolling bearings are capable of engaging with axial engaging portions fixedly provided on the throttle body wall so as to face the contact portions, and the outer rings of at least one of the rolling bearings A spring is arranged between the outer ring and the corresponding engagement part, and further, one of the abutment part and the engagement part is formed as an adjusting screw fastened to the throttle shaft or the throttle body wall, and the setting of the spring is A support structure for a throttle valve, characterized in that a load is adjusted and the set load is applied between an inner ring and an outer ring.