JPH0474536B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a throttle valve opening/closing mechanism for controlling the intake flow rate of an internal combustion engine.

[Conventional technology]

FIG. 7 shows a conventional example of this type of throttle valve opening/closing mechanism. In the figure, 1 is an intake body (throttle body), 2 is a throttle valve shaft, and 3 is a throttle valve fixed to the throttle valve shaft 2. . The throttle valve shaft 2 is rotatably supported via ball bearings 4 and 5 arranged on both sides of the intake body 1, and one end of the throttle valve shaft 2 is provided with a return spring (not shown) or a rotation force from the accelerator pedal. A mechanism for transmitting force is installed, and the opening of the throttle valve 3 is controlled by receiving this rotational force. Generally, when assembling this type of throttle valve opening/closing mechanism, first one of the ball bearings 4 is press-fitted onto the throttle valve shaft 2 via the inner ring 4a of this bearing, and the throttle valve shaft 2 with this bearing 4 is connected to the intake air. Then, the other ball bearing 5 is fitted onto the throttle valve shaft 2, and then the sealing material 7 and the bearing retainer 8 are attached to each of the bearing mounting parts 6 and 6', and finally the throttle valve shaft is inserted into the barrel 1. A throttle valve 3 is attached to 2.

In this type of throttle valve shaft bearing system,
When attaching the ball bearing 5 to the throttle valve shaft 2 by press-fitting it in the same way as the ball bearing 4, it is difficult to completely align the bearing mounting parts 4 and 5 with each other due to the machining accuracy of the intake cylinder, etc., and as a result, the centering If the inner ring 5a on the ball bearing 5 side is forced into the inner ring 5a with a misalignment, the throttle valve shaft 2 will be bent and the movement of the throttle valve shaft 2 will become unsmooth. Therefore, measures are taken to ensure a small gap S between the throttle valve shaft 2 and the inner ring 5a to avoid the influence of misalignment. A conventional technique in which such a minute gap S is provided is disclosed in, for example, Japanese Utility Model Publication No. 60-26201. In addition, normally each ball bearing 4,
The fit between the outer ring 5 and the inner periphery of the bearing mounting portion 6 is a loose fit in order to avoid the influence of dimensional tolerances and deformation of the ball bearing outer ring.

[Problem that the invention seeks to solve]

As mentioned above, in the throttle valve opening/closing mechanism of the type in which the throttle valve shaft is supported by a ball bearing, various considerations such as providing a small gap S between the throttle valve shaft 2 and the inner ring 5a of at least one of the ball bearings 4 and 5 are taken. is being done. By the way, when a high level of mechanical vibration is applied to the throttle valve shaft 2 supported by such a bearing structure,
Due to the structure of the clearance S between the inner ring 5a of one ball bearing 5 and the throttle valve shaft 2 and the loose fit between the outer ring 4b of the other ball bearing 4 and the inner periphery of the bearing mounting part 6, the throttle valve shaft 2 is Vibrations occur within the gap S using the ball bearing 4 as a fulcrum, and as a result, the throttle valve shaft 2 and the ball bearing inner ring 5a collide with each other, causing wear in this part and the intake body made of aluminum alloy or the like. The inner periphery A of the bearing mounting portion 6 of No. 1 sometimes wore out due to rattling of the bearing outer ring 4b. If such a wear phenomenon progresses, the throttle valve shaft may run out, and in the worst case, the throttle valve may fail to return.

The present invention has been made in view of the above points, and an object of the present invention is to effectively suppress vibrations of the throttle valve shaft and ball bearings supported by ball bearings, and It is an object of the present invention to provide a throttle valve opening/closing mechanism that can prevent the occurrence of wear on a mounting part and stabilize the throttle valve opening/closing operation.

[Means for solving problems]

In order to achieve the above object, the present invention takes the following measures. Hereinafter, in order to facilitate understanding of the content of the present invention, the configuration of the present invention will be described with reference to the reference numerals in FIG.

That is, the present invention has a minute gap S between the inner ring 5a of at least one of the ball bearings 4 and 5 supporting the throttle valve shaft 2, and the throttle valve shaft 2, A stopper 10 is fixedly arranged to face one surface of the ball bearing 5 having a minute gap S, and a stopper 10 is provided between the stopper 10 and the ball bearing inner ring 5a having a minute gap S, and a stopper 10 is provided to cooperate with the stopper 10 and the throttle valve shaft 2. An elastic member 11 that applies elastic force in the axial direction to each ball bearing 4, 5 is interposed, and the outer ring 4b, 5b of each ball bearing 4, 5 is pushed into the bearing mounting portion 6, 6' by this elastic force in the axial direction. Part A,
A' to restrict the relative movement between the outer rings of these ball bearings 4, 5 and the bearing mounting parts 6, 6', and to convert the elastic force in the axial direction into a force in the radial direction of the throttle valve shaft (the means In Figure 1, the spring 11 and the inner ring 5
a and the frictional force between the spring 11 and the stopper 10), the relative movement in the radial direction between the ball bearing inner ring 5a having a minute gap S and the throttle valve shaft 2 is restricted.

[Effect]

According to the present invention having such a configuration, the elastic force of the elastic member 11 works together with the stopper 10 and the throttle valve shaft 2 to generate a force in the axial direction of the throttle valve shaft (in the direction of arrows X and Y in the drawing). The elastic force in the direction of arrow X acts on the inner ring 5a on the ball bearing 5 side and the outer ring 5b via the balls, and this force presses the outer ring 5b against the inner part A' of the bearing mounting part 6', and The elastic force in the direction of the arrow Y acts on the outer ring 4b on the ball bearing 4 side (in the example in FIG. 1, the elastic force of the spring member 11 in the direction of the arrow Y acts on the stopper 10, the throttle valve shaft 2, and the ball bearing 4 side (acting on the outer ring 4b via the inner ring 4a and balls of the ball bearings), this force presses the outer ring 4b against the inner part A of the bearing mounting part 6, and these actions cause the outer rings 4a, 5a of the ball bearings 4, 5 and the bearing Mounting part 6, 6'
regulates the relative movement of Further, the elastic force of the elastic member 11 is converted from the axial direction to a force in the radial direction of the throttle valve shaft, thereby regulating the relative movement of the ball bearing inner ring 5a and the throttle valve shaft 2 in the radial direction. Since the force acts to give preload to the ball bearing, the inherent looseness of the ball bearing itself is also eliminated.

Therefore, according to the present invention, even when high vibration is applied to the throttle valve shaft 2 due to the synergistic effect of each of the above-mentioned actions, the ball having the clearance S between the throttle valve shaft 2 and the ball, which is particularly prone to wobbling, is The rattling between the bearing inner rings 5a and the rattling of the outer ring 4b of the ball bearing 4 in the bearing mounting portion 6 are eliminated, and as a result, collisions between these members are eliminated, and the throttle valve shaft, bearing, and bearing mounting are eliminated. The wear resistance of the throttle valve shaft has been improved, and the center runout of the throttle valve shaft has been improved.
The occurrence of malfunctions such as malfunctions can be effectively prevented.

〔Example〕

Embodiments of the present invention will be explained based on FIGS. 1 to 6.

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, and in the figure, the same reference numerals as in the conventional example of FIG. 7 indicate the same or common elements.

That is, in the figure, 1 is an intake cylinder, and bearing mounting parts 6, 6' are provided on both sides of the main body of the intake cylinder 1, and an outer ring, an inner ring, and a ball are formed inside each of the bearing mounting parts 6, 6'. Ball bearings 4 and 5 are disposed, and the throttle valve shaft 2 with the throttle valve 3 is rotatably supported via the ball bearings 4 and 5, and a seal member 7 and a seal member 7 are provided in the bearing mounting portions 6 and 6', respectively. Bearing holders 8, 8' are press-fitted and attached.

In such a throttle valve shaft bearing structure, the inner ring 4a of the bearing 4 of the ball bearings 4 and 5 is press-fitted into the throttle valve shaft 2 before the throttle valve shaft 2 is inserted into the intake cylinder 1. is fixed on the throttle valve shaft 2 by. This press-fitting is performed with a force that resists a pull-out force of at least about 200 kgf. The position of the throttle valve 3 with respect to the air passage is determined by this press-fitted ball bearing 4.
Further, on the bearing 5 side, after the throttle valve shaft 2 is inserted into the intake cylinder 1, the throttle valve shaft 2 is inserted through the inner ring 5a, and between the inner ring 5a and the throttle valve shaft 2,
As described in detail in the [Prior Art] section, a small gap S is ensured for the accuracy and convenience of assembling the throttle valve. In addition, the outer rings 4b and 5b of each ball bearing 4 and 5 are attached to the bearing mounting portion 6, in order to prevent the occurrence of states king phenomenon of the ball bearing itself.
6', and the outer rings 4b and 5b of the ball bearings 4 and 5 are respectively fitted to the inner circumferences of the bearing holders 8 and 6'.
It is held down by 8'.

Therefore, in this embodiment, a space 9 in which a stopper 10 and a disc spring 11, which will be described later, are accommodated is provided inside the bearing presser 8' on the ball bearing 5 side, which has a minute gap S.
will be established. The stopper 10 is fixed on the throttle valve shaft 2 so as to face one surface of the ball bearing 5, and a disc spring 1 generates a spring force of about several tens of kgf between the stopper 10 and the inner ring 5a side of the ball bearing 5.
1 is interposed. The disc spring 11 has a structure in which one end is in direct contact with the inner ring 5a and the other end is in direct contact with the stopper 10.

Since the assembly procedure of this throttle valve opening/closing mechanism is carried out as follows, galling will not occur between the throttle valve 3 and the intake passage (inner periphery of the intake cylinder). First, the ball bearing 4 is press-fitted and fixed to the throttle valve shaft 2 via the inner ring 4a. Next, the throttle valve shaft 2 to which the ball bearing 4 is attached is inserted into the intake cylinder 1, and the sealing material 7 on the bearing 4 side and the bearing retainer 8 are attached to the bearing mounting portion 6. Next, the ball bearing 5 is inserted into the intake cylinder 1 while being inserted into the throttle valve shaft 2. Next, after the elastic member 11 is inserted into the throttle valve shaft 2, the stopper 10 is fixed to the throttle valve shaft 2. Next, the sealing material 7 on the bearing 5 side and the bearing retainer 8'
Attach it to the bearing mounting part 6'. Finally, the throttle valve 3 is attached to the valve shaft 2. Since the throttle valve 3 is attached to the throttle valve shaft 2 after the throttle valve shaft 2 has been completely positioned in the axial direction in this manner, no galling occurs between the throttle valve and the intake passage.

With this structure, the disc spring 11 cooperates with the stopper 10 and the throttle valve shaft 2 to apply the following preload to the ball bearing elements 4a, 4b and 5a, 5b. That is, (1) the elastic force of the disc spring 11 urges the inner ring 5a of the ball bearing 5 in the direction of arrow X, and this force is transmitted to the outer ring 5b side via the balls of the bearing 5 itself, and the outer ring 5b (2) Also, the elastic force acts on the throttle valve shaft 2 in the direction of arrow Y through the stopper 10, and the force of this throttle valve shaft 2 is The pressure is transmitted to the outer ring 4b side through the inner ring 4a and balls press-fitted into the throttle valve shaft 2, and one surface of the outer ring 4b is pressed against the inner part A of the bearing mounting part 6, and due to the elastic pressing force in the axial direction. The rattling between each ball bearing 4, 5 and the bearing mounting portion 6, 6' is regulated, and each ball bearing 4, 5 is connected from the inner ring 4a, 5a to the outer ring 4.
When transmitting force to b, 5b, a couple acts on each inner ring and outer ring, so that the play inherent in each ball bearing 4, 5 itself is also eliminated. (3) Furthermore, the elastic force of the disc spring 11 is caused by the elastic force between the inner ring 5a of the ball bearing 5 and the spring 11.
The contact portion between the spring 11 and the stopper 10 converts into frictional force, and this frictional force restricts the relative movement in the radial direction between the throttle valve shaft 1 and the ball bearing inner ring 5a having a minute gap S.

According to such a bearing structure, when high vibration is applied to the throttle valve shaft 2, the gap S between the ball bearing inner ring 5a and the throttle valve shaft 2, the outer ring 4b of the ball bearing 4, and the bearing The loose fit between the throttle valve shaft 2 and the ball bearings 4 and 5 due to the loose fitting structure with the mounting portion 6 and the inherent wobbling of the bearings.
The above-mentioned regulating actions (1) to (3) have solved the problem of wear between the throttle valve shaft 2 and the ball bearing inner ring 5a, and the bearing mounting part 6 and the bearing outer ring 4b, which were problems that should be improved in the past.
Effectively prevents wear between the parts. As a result, the wear resistance of members such as the throttle valve shaft can be significantly improved, and it is possible to effectively prevent the core runout of the throttle valve shaft and the occurrence of defects such as failure of the throttle valve to return to the throttle valve.

FIG. 3 shows the relationship of forces at the contact portion between the ball bearing inner ring 5a and the disc spring 11 of the throttle valve opening/closing mechanism according to the first embodiment. An elastic force F in the axial direction is applied to the contact portion with the inner ring 5a and the contact portion between the disc spring 11 and the stopper 10. Therefore, frictional forces μF and μ′F are generated in this contact portion due to the static friction coefficients μ and μ′ of these contact portions, and this force causes the friction between the throttle valve shaft 2 and the ball bearing inner ring 5a to Relative motion is regulated.

Here, a specific example of the allowable range of the load applied to the disc spring 11 will be explained based on numerical values.

As a prerequisite, the total weight of the throttle valve shaft to be used (including the bearing attached to the throttle valve shaft, the throttle valve, and throttle drive system parts) is 0.2 kg, and the throttle valve shaft has a height of about 50 G (peak value). Assume that vibration is applied. Further, the coefficient of static friction between the ball bearing inner ring 5a and the disc spring 11 is 0.4, the diameter of the intake body is 4.5 cm, and the diameter of the throttle valve shaft is 1.0 cm.

Under these conditions, the excitation G (weight acceleration)
The external force applied to the throttle valve shaft 2 is as follows: In the radial direction, 0.2Kg (total weight of the throttle valve shaft) x 50G = 10 (Kgf)...(1) In the thrust direction, 0.2Kg x 50G = 10 (Kgf)...(2) ) Also, the external force applied to the throttle valve shaft based on the force due to the negative pressure applied to the throttle valve (suction negative pressure) is: 2.25 ²・π (intake cylinder area) cm ² × 1 (maximum value of suction negative pressure) In other words, the throttle valve is fully closed when the engine is rotating) =
15.9 (Kgf) ...(3) The thrust direction is 0, and if you total the above, in the radial direction of the throttle valve shaft, 10 + 15.9 = 25.9 (Kgf) ... (4) In the thrust direction, 10 + 0 = 10 (Kgf) …(5) External force is applied.

Therefore, when the static friction coefficient between the ball bearing inner ring and the disc spring is 0.4, the force F required to suppress the force applied in the radial direction (surface pressure = elastic force) is F = 25.9 / 0.4 = 64.75 ≒65 (Kgf) …(6) is the minimum required.

Further, the maximum value under the elastic force is naturally not allowed to exceed the pull-out force of the ball bearing inner ring 4a on the side press-fitted into the throttle valve shaft 2. Here, when the minimum value of the tightness of the press-fitted part to the ball bearing inner ring 4a is set to 0.004 mm, the pull-out force F ₁ between the ball bearing inner ring on the press-fit side and the shaft is normally F ₁ = 192 (Kgf)...( 7) Therefore, the elastic force is approximately 65 (Kgf) as shown above.
If so, the ball bearing inner ring will not be pulled out from the throttle valve shaft 2.

From the above, under the above conditions, the disc spring 11
The force applied (tolerable range) may be in the range of 65 to 192 (Kgf).

5 and 6a and 6b show a specific embodiment of the stopper 10 used in the above embodiment.The stopper 10 in this embodiment is formed by using a split nut with a locking function. It is screwed onto the throttle valve shaft 2 and is locked by tightening the locking screw 12 and bending the spring receiving portion 10b in the direction of arrow C.

2 and 4 show a second embodiment of the present invention.

In the symbols of this embodiment, the same parts as those of the first embodiment indicate the same or common elements.
A particular feature of this embodiment is that a wedge-shaped member 13 is fitted between the throttle valve shaft 2 and the ball bearing inner ring 5a having a minute gap S.
is biased in the direction of arrow X by the force of a disc spring 11 disposed between the ball bearing 5 and the stopper 10. According to this embodiment, the elastic force applied in the axial direction of the throttle valve shaft 2 is applied to the wedge-shaped member 13.
As shown in Fig. 4, it is decomposed into an axial force F and a radial force F' with respect to the throttle shaft 2,
The axial force F in this component causes the outer ring 5b on the ball bearing 5 side to press against the inner part A' of the bearing mounting portion 6' via the inner ring 5a and the balls. () Further, the radial component force F' generated in the wedge-shaped member 13 restricts the relative movement of the ball bearing inner ring 5a and the throttle valve shaft 2 in the radial direction (Z direction). () Further, the spring force of the disc spring 11 presses the outer ring 4b on the ball bearing 4 side against the inner part A on the bearing mounting portion 6 side via the stopper 10, the throttle valve shaft 2, the press-fit inner ring 4a, and the balls. Therefore, as in the first embodiment, the joint action of () to () above eliminates looseness between the throttle valve shaft 2 and ball bearings 4 and 5, and significantly improves the wear resistance of these parts. It is possible to prevent problems such as center runout of the throttle valve shaft and failure of the throttle valve to return.

In each of the above embodiments, a disc spring 11 is used as an elastic member for restricting the movement of a throttle valve, a bearing, etc., but an appropriate elastic material such as a coil spring or a rubber material may be used instead. . In addition, in a ball bearing having a small gap S, not only the bearing 5 on one side but also the bearing 4 on the other side may be provided with a gap S instead of being press-fitted. In this case, the gap S may be provided in the mounting portion of each ball bearing. If the elastic member 11, stopper 10, etc. are arranged,
The force of each elastic member 11 applies preload to each ball bearing 4,5.

〔Effect of the invention〕

As described above, according to the present invention, the vibration of the throttle valve shaft and bearings supported by ball bearings is effectively suppressed, the occurrence of wear on the throttle valve shaft and the bearing mounting portion is prevented, and the throttle valve opening/closing operation is prevented. It is possible to provide a throttle valve opening/closing mechanism that can achieve stability.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a first embodiment of the present invention, Fig. 2 is a sectional view showing a second embodiment of the invention, and Fig. 3 is a sectional view of essential parts explaining the operation of the first embodiment. ,
FIG. 4 is a sectional view of a main part explaining the operation of the second embodiment, FIG. 5 is a partially omitted sectional view showing a specific aspect of the stopper used in the first embodiment, and FIGS. 6a and b 7 is a front view and a sectional view of the stopper, and FIG. 7 is a sectional view showing a conventional throttle valve opening/closing mechanism. 1... Intake cylinder, 2... Throttle valve shaft, 3... Throttle valve, 4, 5... Ball bearing, 4a, 5a... Inner ring, 4b, 5b... Outer ring, 6, 6'... Bearing mounting part , 10... Stopper, 11... Elastic member, 13
... Wedge-shaped member, A, A' ... Part of the bearing mounting part, S ... Minute gap.

Claims (1)

[Scope of Claims] 1. Bearing mounting parts are provided on both sides of the intake cylinder body, and ball bearings consisting of an outer ring, an inner ring, and balls are fixedly arranged in each of the bearing mounting parts, and the throttle valve is connected through the ball bearings. In the throttle valve opening/closing mechanism, the throttle valve shaft is supported, and the throttle valve shaft has a minute gap between the inner ring of at least one of the ball bearings and the throttle valve shaft. A stopper is fixedly arranged to face one surface of the ball bearing having the ball bearing, and between the stopper and the inner ring of the ball bearing having the minute gap, there is provided a shaft that cooperates with the stopper and the throttle valve shaft to support each of the ball bearings. An elastic member that applies an elastic force in the axial direction is interposed, and the outer ring of each ball bearing is pressed against a part of the inside of the bearing mounting part by the elastic force in the axial direction, so that the outer ring of these ball bearings and the bearing mounting part are connected to each other. The radial relative movement between the ball bearing inner ring having the minute gap and the throttle valve shaft is controlled through a means for regulating the relative movement of the ball bearing inner ring having the minute gap and converting the elastic force in the axial direction into a force in the radial direction of the throttle valve shaft. A throttle valve opening/closing mechanism characterized by being configured to restrict movement. 2. In claim 1, the means for converting the elastic force in the axial direction into the force in the radial direction of the throttle valve shaft includes elastically contacting the elastic member with one end of the inner ring of the ball bearing having the minute gap. The throttle valve opening/closing mechanism is constructed using the frictional force generated by this elastic contact. 3. In claim 1, the means for converting the elastic force in the axial direction into a force in the radial direction converts the force of the elastic member between the ball bearing inner ring having the minute gap and the throttle valve shaft. A throttle valve opening/closing mechanism consisting of a wedge-shaped member that is fitted so as to be disassembled in the axial and radial directions. 4. The throttle valve opening/closing mechanism according to any one of claims 1 to 3, wherein the elastic member is a disc spring. 5. The throttle valve opening/closing mechanism according to any one of claims 1 to 3, wherein the elastic member is made of a rubber material.