JPH0515578Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an idle speed control valve for an internal combustion engine.

<Prior art> In order to control the rotational speed during idling operation (hereinafter referred to as idle speed) of an internal combustion engine equipped with an intake throttle valve in the intake passage, a bypass is provided between upstream and downstream of the intake throttle valve. There is one in which the degree of opening of the passage can be changed. Furthermore, conventional idle speed control valves that control the idle speed of the engine by changing the opening degree of the bypass passage in this way (see, for example, Japanese Utility Model Application Publication No. 113575/1983) are shown in FIGS. 2 and 3, for example. There is something like the one shown below.

To explain this, a valve seat 3 with a part of the cylindrical surface as a sealing surface is formed in a housing 2 in which a bypass passage 1 is formed to bypass between the upstream and downstream sides of an intake throttle valve (not shown). Bypass passage 1 upstream and downstream of the valve seat 3 via the opening 3a
communicate. Further, a valve body 4 whose sealing surface is a part of the cylindrical surface corresponding to the valve seat 3 is fixed to a hollow shaft 5, and this hollow shaft 5 is connected to a fixed shaft 6 and bearings 7, 8.
It is rotatably supported by the housing 2 via. As a result, the valve body 4 becomes rotatable about the central axis of the cylinder, and as the valve body 4 rotates, the opening area of the opening 3a formed in the valve seat 3 is increased or decreased, and the bypass passage 1 is The engine idle speed is controlled by increasing or decreasing the flow rate of intake air supplied to the combustion chamber of the engine through the engine.

<Problems to be solved by the invention> By the way, according to such a conventional idle speed control valve, as shown in FIG. There is one location on the circumference centered around the axis of rotation.
For this reason, a large load generated by the difference in intake pressure between the upstream and downstream sides of the valve body 4 acts only in one direction on the rotation axis of the valve body 4, causing a shift in the rotation center and resulting in rotation failure. There were problems such as uneven wear of the sliding contact parts.

The present invention was developed in view of the above problems, and its purpose is to avoid applying a large load in one direction to the rotating shaft of the valve body of the idle speed control valve, and to solve the above problems. do.

<Means for Solving the Problems> Therefore, the present invention provides a housing that forms a bypass passage that bypasses between upstream and downstream of an intake throttle valve installed in an intake passage of an engine, and a negative pressure side of the bypass passage of the housing. A valve seat provided in a negative pressure side opening opening to the valve seat, and a valve body that changes the opening area of the negative pressure side opening by rotating around a predetermined rotation axis while slidingly contacting the valve seat. , in an idle speed control valve for an internal combustion engine that controls the amount of intake air passing through the bypass passage by changing the opening area of the negative pressure side opening, the negative pressure side opening is substantially symmetrical about the rotation axis of the valve body. A plurality of them were arranged at different locations, and the atmosphere side openings were opened at positions approximately equidistant from each of the plurality of negative pressure side openings.

<Function> According to the idle speed control valve having such a configuration, a plurality of negative pressure side openings in which valve seats are formed are distributed at substantially symmetrical positions with respect to the rotation axis of the valve body. The load of negative pressure applied in the radial direction of the rotating shaft of the rotating shaft can be canceled out, and since the atmospheric side openings are provided at equal distances from each negative pressure side opening, the negative pressure generated by each negative pressure side opening can be canceled out. It is possible to substantially equalize the loads on the valve body and maintain a highly accurate load balance in the radial direction of the valve body.

<Example> An example of the present invention will be described below based on FIG. 1.

10 in the figure is a housing according to the present invention,
Cylindrical cavity 10a provided in this housing 10
Valve seats 11a, 11 with a part of the inner surface as a sealing surface
b are distributed at approximately symmetrical positions with respect to the central axis (rotation axis) of the cylinder, one each. Negative pressure side passages 13a and 13b are provided in communication with openings 12a and 12b (negative pressure side openings) opened in the valve seats 11a and 11b, respectively, and negative pressure side passages 13a and 13b are provided in the cylindrical cavity 10a from the cylindrical axial direction. Atmospheric side passage 14 opens at a position approximately equidistant from each of the openings 12a and 12b.
(atmosphere side opening) is provided, and the bypass passage that bypasses between the upstream and downstream of the intake throttle valve (not shown) includes the atmosphere side passage 14, the cylindrical cavity 10a,
Openings 12a, 12b and negative pressure side passages 13a, 1
3b.

A valve body 15 whose sealing surface is a part of the cylindrical surface corresponding to the two valve seats 11a and 11b.
a and 15b are fixed to a hollow shaft 16, and this hollow shaft 16 is rotatably supported by the housing 10 via a fixed shaft 17 and the like.

According to this configuration, the intake air introduced into the cylindrical cavity portion 10a from the atmosphere side passage 14 flows through the hollow shaft 1.
They are divided into substantially opposite directions around the six-axis center and supplied to the combustion chamber of the engine through negative pressure side passages 13a and 13b, respectively. At this time, the valve body 15
A differential pressure is generated between the upstream and downstream of the openings 12a and 12b whose opening areas are increased and decreased by the openings a and 15b,
The load due to this pressure difference is applied to the hollow shaft 16 and the fixed shaft 17.
However, since the differential pressure is generated at symmetrical positions across the shaft and in opposite directions, the loads acting on the hollow shaft 16 and the fixed shaft 17 are canceled out. However, each opening 12a,
Since the distances to 12b are approximately equal, the loads acting in opposite directions across the rotating shaft are balanced, and the load substantially acting on the shaft can be sufficiently reduced.
Therefore, the centers of rotation of the valve bodies 15a, 15b do not shift due to the influence of the pressure difference, good rotatability can be maintained, and occurrence of uneven wear is also prevented.

<Effects of the invention> As explained above, according to the invention, the load due to the difference in intake pressure is applied at approximately the same level in both directions in the radial direction of the rotation axis of the valve body of the idle speed control valve. This has the effect that the applied load can be sufficiently reduced by canceling out each other, and the valve body can be rotated in a good and stable manner.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the idle speed control valve for an internal combustion engine according to the present invention;
The figure is a sectional view showing an example of a conventional idle speed control valve, and FIG. 3 is a sectional view taken along the line AA in FIG. 10...Housing, 10a...Cylindrical cavity, 11a, 11b...Valve seat, 12a, 12b...
...opening, 13a, 13b...negative pressure side passage, 14
...Atmosphere side passage, 15a, 15b...Valve body, 16
...Hollow shaft.

Claims (1)

[Claims for Utility Model Registration] A housing that forms a bypass passage that bypasses between the upstream and downstream sides of an intake throttle valve installed in an intake passage of an engine, and a negative pressure side opening of the housing that opens on the negative pressure side of the bypass passage. a valve seat provided in the negative pressure side opening, and a valve body that changes the opening area of the negative pressure side opening by rotating around a predetermined rotation axis while slidingly contacting the valve seat, and the valve body changes the opening area of the negative pressure side opening. In an idle speed control valve for an internal combustion engine that controls the amount of intake air passing through the bypass passage by changing the opening area, the negative pressure side openings are distributed at substantially symmetrical positions about the rotation axis of the valve body. What is claimed is: 1. An idle speed control valve for an internal combustion engine, characterized in that a plurality of idle speed control valves are provided, and the atmosphere side openings of the bypass passages are opened at positions approximately equidistant from each of the plurality of negative pressure side openings.