JPH048268Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention A-1. Field of Industrial Application The present invention relates to a throttle valve operating device in an internal combustion engine.

A-2 Prior Art Conventionally, as a bearing structure for a throttle valve in an internal combustion engine, a bearing hole with a smooth inner circumference is generally formed in the throttle body, and a throttle shaft with a smooth outer circumference is rotatably fitted into the bearing hole. The throttle shaft is supported by surface contact between the throttle shaft and the bearing hole when negative pressure in the intake pipe is applied.

Also, as a return spring for the throttle valve, one end of it is connected to the fixed side and the other end is fixed directly to the throttle lever, so that the return load of the return spring is applied to the opening from the idle opening of the throttle valve. There is one that increases the amount in proportion to the amount.

E-3 Problems to be solved by the present invention By the way, the force that opposes the opening force of the throttle valve is determined by the area of the throttle valve x the negative intake pressure x the frictional resistance of the bearing + the return spring load. In the conventional bearing structure, which supports the throttle shaft by surface contact, the frictional resistance of the bearing is large, and therefore the opening operation force of the throttle valve is inevitably large. In particular, for the purpose of improving the acceleration performance of automobiles, the inner diameter of the intake cylinder and the throttle valve diameter are increased in multi-cylinder, one-intake valve type engines, and the one-cylinder, one-intake valve type (e.g., Publication No. 101725)
In a device that increases the amount of intake air, the differential pressure between the downstream and upstream parts of the throttle valve becomes extremely high at the start of pressing the accelerator pedal, where the throttle valve begins to open from the idle opening. The frictional resistance of the bearings becomes particularly large, and the opening operating torque of the throttle valve becomes large, making it difficult to press the accelerator pedal and making it difficult for the throttle valve to return when decelerating, deteriorating drivability. There's a problem.

In such a thing, as in the conventional case,
If a return spring is used that increases from the idle opening of the throttle valve in proportion to the idle opening, a larger return spring load will be applied in the region where the frictional resistance of the bearing is greatest as described above, and the throttle The opening actuation torque of the valve further increases, further exacerbating the above-mentioned problem.

Therefore, the present invention reduces the return load of the return spring of the throttle valve to a small value in the region where the accelerator pedal starts to be depressed, where the throttle valve begins to open from the idle opening, without increasing in proportion to the opening of the throttle valve. maintain on load;
It is an object of this invention to solve the above-mentioned problem by making it possible to increase the opening degree proportionally as usual in the subsequent opening range.

B. Structure of the invention B-1. Means for solving the problems In order to solve the above-mentioned problems, the present invention forms an engagement groove 5 in the throttle lever 4 and a guide groove 7 on the throttle body 1 side. The formed guide cam 6 is fixed, and the fulcrum at one end of the return spring 9 is fixed to the throttle body 1 side, and the fulcrum at the other end is commonly engaged with both the grooves 5 and 7, so that the throttle valve 2 is opened. This is characterized in that the fulcrum at the other end of the return spring 9 is displaced by the combination of the two grooves 5 and 7 depending on the degree of rotation, thereby changing the load on the return spring 9.

Lo-2 Action When the engagement groove 5 formed in the throttle lever 4 is displaced according to the opening degree of the throttle valve 2, the return spring 9, which is commonly engaged with the engagement groove 5 and the guide groove 7, is moved. The fulcrum at the other end is displaced by the combination of the engagement groove 5 and the guide groove 7. Therefore, the shapes of both grooves 5 and 7 are combined so that the fulcrum at the other end of the return spring 9 does not extend the return spring 9 in the opening range of the throttle valve from the idle opening degree. By setting it to shift, it is possible to prevent an increase in the load of the return spring 9 in this opening range, thereby preventing an increase in the opening operating torque of the throttle valve due to the return spring load. In addition, in a region where the opening degree increases from this opening degree region, both grooves 5 and 7 are set so that the fulcrum of the other end of the return spring 9 moves by extending the return spring 9. The load on the return spring 9 can be increased in proportion to the degree of rotation.

RO-3 Embodiment Next, a first embodiment of the present invention shown in FIGS. 1 to 4 will be described.

1 is a throttle body, 2 is a throttle valve, 3 is a throttle shaft, and 4 is a throttle lever fixed to the throttle shaft 3, in which a radially long engagement groove 5 is formed. A guide cam 6 is fixed to the throttle body 1, and a guide groove 7 is formed in this guide cam. A common spring support pin 8 is slidably fitted into the guide groove 7 and the engagement groove 5. A return spring 9 has one end fixed to the spring support pin 8 and the other end fixed to a arm 10 fixed to the throttle body 1, and is installed so as to bias the throttle lever 4 in the closing direction. . The shape of the guide groove 7 is such that when the throttle lever 5 is rotated in the opening direction (rotation clockwise in the figure), the spring support pin 8 can be moved to an opening slightly wider than the idle opening of the throttle valve. In the area up to this point, there is a horizontal part 7a that is guided in the horizontal direction to maintain the load on the return spring 9 at a constant small load, and after this opening range, there is a horizontal part 7a that is guided downward and the load on the return spring 9 is proportional to the opening degree. It is formed by a vertical portion 7b which is increased in size.

Next, the operation of the embodiment shown in the drawings will be explained. FIG. 1 shows the throttle valve 2 in an idling opening state, and the spring support pin 8 is located in the horizontal portion 7a of the guide groove 7. Therefore, the return spring 9 is contracted and its return load is small. Next, from this state, when the accelerator pedal is depressed and the throttle lever 4 is rotated clockwise in the figure to increase the opening degree of the throttle valve 2, in the initial region, the spring support pin 8 moves into the guide groove 7. It transitions to a horizontal state along the horizontal portion 7a. Therefore, in this region, even if the opening degree of the throttle valve 2 increases, the return load of the return spring 9 is not increased, but is maintained at the same small load as described above, and the opening operating torque of the throttle valve is increased. The return spring load is not increased.

When the throttle valve 2 opens further than the above-mentioned opening range, the spring support pin 8 is guided by the vertical portion 7b of the guide groove 7 and descends, and when the throttle valve 2 is fully open, it is in the state shown in FIG. 3. .

The return spring 9 is expanded by the lowering of the spring support pin 8, and its return load increases in proportion to the opening degree of the throttle valve 2. In this region, the differential pressure of the intake pipe negative pressure decreases in proportion to the opening degree of the throttle valve 2, thereby reducing the bearing friction force of the throttle shaft.
Even if the load on the return spring 9 increases, there is no problem.

Further, the return from the fully open state to the fully closed state is performed by an operation opposite to the above-mentioned operation.

The shapes of the engagement groove 5 of the throttle lever 4 and the guide groove 7 of the guide cam 6 are set as desired depending on conditions such as the negative pressure in the intake pipe. That is, in the case where the negative pressure near full opening is high, the vertical portion 7b of the guide groove 7 may be shaped to be inclined forward to reduce the amount of increase in the load of the return spring 9.

FIG. 5 shows another embodiment in which the other end of the return spring 9 is connected to the engagement groove 5 of the throttle lever 4.
The bent portion 9 is bent and loosely fitted into the sleeve 11 which is loosely fitted in common with the guide groove 7b of the guide cam 6.
The retaining members 12 and 13 are fixed to both ends of the a, and the other structures are the same as those described above.

C. Effect of the invention As described above, according to the invention, by combining the engagement groove 5 and the guide groove 7, the load on the return spring 9 can be changed according to the opening degree of the throttle valve. In the region where the accelerator pedal starts to open from the idle opening, the return load of the return spring is maintained at a small value to reduce the opening operating torque of the throttle valve in this region, thereby improving the operability of the throttle valve. It is possible to reduce the driver's fatigue by improving the speed and reducing the need to press the accelerator pedal, and the load on the return spring can be increased as usual after the above-mentioned region.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the first embodiment of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a front view of the fully open state, Fig. 4 is an enlarged sectional view of the support part of the return spring, and Fig. 5 The figure is an enlarged sectional view showing another embodiment of the support part in the return spring. 1... Throttle body, 2... Throttle valve, 4... Throttle lever, 5... Engagement groove,
6... Guide cam, 7... Guide groove, 8... Spring support pin, 9... Return spring.

Claims (1)

[Scope of utility model registration request] An engagement groove 5 is formed in the throttle lever 4, and a guide cam 6 with a guide groove 7 is fixedly installed on the throttle body 1 side.The fulcrum of one end of the return spring 9 is fixed to the throttle body 1 side, and the other end of the return spring 9 is fixed to the throttle body 1 side. A fulcrum is commonly engaged with both the grooves 5 and 7, and depending on the opening degree of the throttle valve 2, the fulcrum at the other end of the return spring 9 is displaced by the combination of both the grooves 5 and 7, thereby forming a return spring. 9. An operating device for a throttle valve in an internal combustion engine, characterized in that the load of step 9 is changed.