JPH0322529Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a return device for a throttle valve of an internal combustion engine.

<Prior Art> The amount of intake air taken into the combustion chamber of an internal combustion engine is controlled by the opening degree of a throttle valve in a throttle chamber provided in an intake passage. A conventional example of such a throttle valve return device is shown in FIGS.
There is one shown in Figure 3.

That is, a throttle valve (not shown) provided in the throttle chamber 1 is fixed to a throttle shaft 2, and an end of the throttle shaft 2 projects from the outer wall of the throttle chamber 1. A throttle drum 3 is fixed to the end of the throttle shaft 2.

Then, by using a throttle wire (not shown), the throttle drum 3 is rotated clockwise in FIG. 1, and the throttle valve is opened via the throttle shaft 2.

Further, in order to close the throttle valve, the throttle shaft 2 between the throttle drum 3 and the outer wall of the throttle chamber 1 has small and large diameter return springs 4 and 5 coaxially arranged as torsion coil springs. It is installed in a shape. That is, a small-diameter return spring 4 is installed inside a cylindrical sleeve 6 attached to the throttle drum 3, and a large-diameter return spring 5 is installed outside the sleeve 6, and one end of these return springs 4, 5 is installed. is locked to a fixing pin 7 attached to the outer wall of the throttle chamber 1.
The other end of the small diameter return spring 4 is locked in a locking hole 6a formed in the sleeve 6, and the other end of the large diameter return spring 5 is locked in the shoulder of the throttle drum 3. I've let it happen.

The elastic force of these return springs 4 and 5 causes the throttle drum 3 to rotate counterclockwise in FIG. 1, thereby closing the throttle valve.

Here, the throttle drum 3 and sleeve 6 are attached to the throttle shaft 2 together with a spacer 8 and a spring receiver 9 by being tightened together with a nut 10.

However, in such a conventional throttle valve return device, the large-diameter return spring 5 contacts the small-diameter return spring 4 protruding from the locking hole 6a of the sleeve 6, and the large-diameter return spring 5 If the throttle drum is tilted as shown in the figure, interference occurs between the lines of the return spring 5 and the elastic force of the return spring 5 does not act smoothly on the throttle drum 3, which affects the control of the throttle valve. Ta.

<Purpose of the invention> In view of these conventional problems, the present invention prevents the occurrence of stiffness in the spring by preventing contact between the other end of the small diameter torsion coil spring and the large diameter torsion coil spring. The purpose is to

<Structure of the invention> For this reason, the present invention locates the locking hole of the sleeve in which the other end of the small-diameter torsion coil spring is locked near the coil winding end position on the other end of the large-diameter torsion coil spring. Therefore, it is formed so as to face the extension side in the winding direction.

<Example> The present invention will be described below based on an example shown in FIGS. 4 and 5. Note that the same elements as in the conventional example will be described with the same reference numerals as in FIGS. 1 to 3.

In the figure, a cylindrical sleeve 6 is attached to a throttle drum 3 attached to the end of the throttle shaft 2 coaxially with the throttle shaft 2, as in the prior art. A small diameter return spring 11 made of a torsion coil spring is disposed inside the sleeve 6, and a large diameter return spring 12 made of a torsion coil spring is disposed outside the sleeve 6. The ends of these small-diameter and large-diameter return springs 11, 12 are engaged with pins 7 provided upright in a throttle chamber (not shown), as shown in FIG. The other end of the large-diameter return spring 12 is secured to the shoulder of the throttle drum 3.

Further, the other end of the small diameter return spring 11 is locked in a locking hole 6a of the sleeve 6. This hole 6a is opened at a position shifted by θ degrees from the position where the large-diameter return spring 12 is locked to the throttle drum 3 toward the extension side in the winding direction of the large-diameter return spring 12.

According to the return device having such a configuration, the other end of the small-diameter return spring 11 is disposed within a predetermined angle θ° on the extension side of the other end of the large-diameter return spring 12 at the winding end position of the coil. Therefore, since the other end of the small diameter return spring 11 is located in the gap between the large diameter return spring 12 and the throttle drum 3, it is possible to prevent the large diameter return spring 12 from coming into contact with the small diameter return spring 11. . Therefore, the large-diameter return spring 12 does not come into contact with the other end of the small-diameter return spring 12, so the large-diameter return spring 11 does not tilt, thereby preventing interference between the lines of the return springs 12. This prevents coil stiffness. As a result, the elastic force of the return spring 11 is applied to the throttle drum 3.
The throttle valve operates smoothly and the control performance of the throttle valve is improved.

<Effects of the invention> As explained above, in the present invention, the locking hole of the sleeve is formed near the winding end position of the coil on the other end side of the large diameter coil spring and on the extended side in the winding direction. Therefore, since the other end of the small-diameter coil spring is located in the gap between the ends of the large-diameter coil spring, contact between the other end of the small-diameter coil spring and the large-diameter coil spring can be prevented. Therefore, interference between the wires of the coil springs can be prevented, so that the coils can be prevented from stiffening, and the elastic force of the coil spring can be smoothly applied to the throttle drum, improving the control performance of the throttle valve.

[Brief explanation of the drawing]

Fig. 1 is a front view of main parts showing a conventional example of a throttle valve return device, Fig. 2 is a view taken in the direction of - arrow in Fig. 1, Fig. 3 is a view taken in the direction of Fig. 1, and Fig. 4 is a FIG. 5 is a front view of essential parts showing an embodiment of the invention, and is a view taken along the arrow in FIG. 4. 1... Throttle chamber, 2... Throttle shaft, 3... Throttle drum, 6... Sleeve, 6
a... Locking hole, 11... Small diameter return spring,
12...Large diameter return spring.

Claims (1)

[Scope of utility model registration request] A throttle drum connected to the throttle wire is attached to the end of the throttle shaft protruding from the outer wall of the throttle chamber main body, and a cylindrical sleeve on the inner side of the throttle chamber side of the throttle drum is connected to the throttle shaft. They are installed coaxially, with a small diameter torsion coil spring arranged inside the sleeve and a large diameter torsion coil spring arranged outside the sleeve, with one end of each spring protruding from the throttle chamber body. The other end of the large-diameter torsion coil spring is fixed to the throttle drum, and the other end of the small-diameter torsion coil spring is formed on the peripheral wall of the sleeve near the throttle drum. In a return device for a throttle valve of an internal combustion engine, the locking hole of the sleeve is connected to the other end of the large-diameter torsion coil spring near the end of the coil winding, and then A return device for a throttle valve of an internal combustion engine, characterized in that it is formed so as to face an extension side.