JP2570865B2 - Throttle valve device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a throttle valve device constituting a throttle mechanism for controlling an intake air amount in an internal combustion engine.

[Prior art] In a throttle valve, a butterfly plate is set in a bore in which an air flow is set.
The butterfly plate is mounted on a rotatably supported shaft.

Such a throttle valve is disclosed, for example, in Japanese Patent Application Laid-Open No. 62-12 / 1987.
It is supported by a support mechanism as shown in JP-A-9538. That is, in this throttle valve support mechanism, both ends of a throttle shaft on which a butterfly plate acting as a throttle valve is mounted are supported by ball bearings, and resonance of a throttle rotating member occurs due to vibration of the internal combustion engine. In order to prevent the internal rolling surface of the ball bearing from being seriously damaged at the time of the rotation, a gap between the bearings is eliminated by a disc spring.

FIG. 2 shows a conventional throttle valve device having such a support mechanism. A throttle shaft 12 having a butterfly plate 11 attached thereto has a bore 13 through which an intake air flow flows.
Is rotatably supported by the throttle body 14 formed with the holes. That is, both ends of the throttle shaft 12 are supported by the throttle body 14 by the ball bearings 151 and 152, respectively.

Further, a disc spring 17 is interposed between one of the ball bearings 151 and the engagement surface 16 formed on the throttle body 14 to prevent the shaft 12 from moving in the thrust direction with a certain rated load. . Here, a nut 18 is attached to the tip of the shaft 12 so that the load of the disc spring 17 set between the bearing 151 and the engagement surface 16 of the throttle body 14 can be obtained at a specified rated load. The nut 18 is used to adjust the length of the disc spring 17 to be adjusted. That is, the throttle shaft
If the related dimensions of the ball bearings 151, 152, and the throttle body 14 change, the length of the disc spring 17 will change.
It is adjusted by tightening.

In particular, since the disc spring 17 has a structure with a high spring constant, a mechanism for adjusting the set load of the spring 17 is required. Further, as compared with the spring constant, the outer race of the ball bearing 151 and the corresponding mechanism are adjusted. It is difficult to make the distance from the mating surface 16 a constant value due to the manufacturing relationship of such a throttle valve. Therefore, in order to keep the set load of the disc spring 17 constant, an adjusting mechanism using the nut 18 is required.
Inevitably, the throttle valve support mechanism has a complicated configuration.
In addition, when assembling the throttle valve, it is necessary to adjust the load using the nut 18.

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and enables not only to simplify the structure for supporting the throttle valve in particular and to reduce the size in the thrust direction. No work such as load adjustment is required at the time of assembly, and the movement of the throttle shaft in the thrust direction is reliably prevented by the specified rated load, and vibration of the mechanism for transmitting torque to the throttle shaft, etc. Therefore, it is an object of the present invention to provide a throttle valve device in which the operation stability is easily ensured while the throttle valve device is easily suppressed.

[Means for Solving the Problems] In a throttle valve device according to the present invention, both ends of a throttle shaft are rotatably supported on a throttle body by ball bearings, respectively. During this time, a compression coil spring is interposed so as to prevent the throttle shaft from moving in the thrust direction.

[Operation] In the throttle valve device configured as described above, the movement of the throttle shaft in the thrust direction is prevented by the compression coil spring. Therefore, for example, due to manufacturing variations of the throttle valve device,
Even if the distance between the outer ring of the ball bearing and the engagement surface of the throttle body changes, the amount of change in the set load is small because the spring constant of the compression coil spring is low. For this reason, the set load of the compression coil spring remains almost constant even when the distance between the outer ring of the ball bearing and the engagement surface of the throttle body changes. In particular, a mechanism for adjusting the distance becomes unnecessary, and the throttle The structure of the valve support mechanism is reduced in size and simplified.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional configuration of the throttle body 21. The throttle body 21 has a bore 22 through which intake air flows. Inside the bore 22 of the throttle body 21,
The butterfly plate 23 is set, and this butterfly plate 23
The reference numeral 23 is attached to a throttle shaft 24, and is rotated in the bore 22 with the rotation of the shaft 24, thereby changing the area of the air circulation passage so that the intake air amount is variably controlled.

The throttle shaft 24 has a ball bearing 25 and
26 is rotatably supported by the throttle body 21.

The throttle body is opposed to the outer ring of one ball bearing 25 supporting the throttle shaft 24.
An engagement surface 27 is formed on the engagement 21, and a compression coil spring 28 is interposed between the engagement surface 27 and the outer ring of the ball bear link 25. The coil spring 28 is made of, for example, a stainless steel wire.

Here, the throttle shaft 24 to which the butterfly plate 23 is attached is coupled to the actuator 30 via gears 291 and 292. The actuator 30 is driven by, for example, depressing an accelerator pedal (not shown), and the butterfly plate 23 is rotated according to the operation amount of the pedal. The amount of air passing through the bore 22 is changed by the rotation of the butterfly plate 23, and the output of an engine (not shown) to which the air passing through the bore 22 is supplied is controlled.

Note that oil seals 31 and 32 are mounted inside the ball bearings 25 and 26, respectively, in order to prevent leakage of air passing through the bore 22 as described above. In this case, the oil seal 31 is disposed so as to enter the inside of the cylindrical center hole of the compression coil spring 28, and the length of the throttle shaft 24 in the thrust direction corresponding to the thickness of the oil seal 31 is not required. The length of the portion of the body 21 along the shaft 24 can be reduced.

That is, in the throttle valve device configured as described above, a compression coil spring 28 having a sufficiently smaller spring constant than the conventional disc spring is provided between the ball bearing 25 and the engagement surface 27 of the throttle body 21. The compression coil spring 28 is interposed and prevents the throttle shaft 24 from moving in the thrust direction.

As a result, even if the assembly length of the compression coil spring 28 changes, the amount of change in the set load of the coil spring 28 becomes small. Therefore, in order to set the load of the compression coil spring 28 to the specified set load, it is not necessary to particularly adjust the installation length thereof, and an adjusting means such as a conventional nut is unnecessary. Therefore, the nut is not required, and the adjusting operation is not required, and the mounting operation is simplified. Further, since an appropriate load is applied to the coupling mechanism such as the gears 291 and 292 that transmits the rotational force to the throttle shaft 24 by the compression coil spring 28, the coupling mechanism exists in this coupling mechanism. The rattling is absorbed, and wear due to the friction can be effectively suppressed.

Further, as shown in FIG. 2, the direction of assembling of a conventional disc spring used is determined. However, in the compression coil spring 28, the mounting direction is arbitrary and the mounting operation is simplified, and the compression coil spring 28 can be arranged outside the oil seal 31 as well. Therefore, in addition to the fact that the adjusting nut is not required, it is effective to avoid the enlargement of the throttle body 21.

In addition, as the material of the compression coil spring 28 used here, a spring steel material such as a spring steel material, a hard steel material, a piano wire, an oil-tempered wire, or the like can be used.

[Effect of the Invention] As described above, according to the throttle valve device of the present invention, the compression coil spring is used to prevent the throttle shaft from moving in the thrust direction. The assembly can be set without any special adjustment of the load, and not only can the configuration be simplified, but also the assembly workability is simplified, and the effect of suppressing the enlargement of the throttle body can be exerted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a throttle valve device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a conventional throttle valve device. 21: Throttle body, 22: Bore, 23: Butterfly plate, 24: Throttle shaft, 25, 26: Ball bearing, 27: Engagement surface, 28: Compression coil spring.

Claims (2)

(57) [Claims] A throttle shaft integrally provided with a butterfly plate set in a bore; ball bearings provided at both ends of the throttle shaft for supporting the shaft on a throttle body; and the throttle of the ball bearing An oil seal set on the inner side in the thrust direction of the shaft; and a compression interposed between the one ball bearing and an engagement surface formed on the throttle body so as to surround the outer side of the oil seal. A throttle valve device comprising: a coil spring; wherein the compression coil spring is set coaxially with the shaft and is set so as to apply a thrust force to the shaft. 2. An actuator mechanism for driving the throttle shaft is coupled to the shaft via an operating force transmitting mechanism, and the compression coil spring is applied to the transmitting mechanism via the throttle shaft. Item 3. The throttle valve device according to Item 1.