JPH0331854Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a positioning pin device for axially positioning a rotating shaft.

<Prior art> In the intake system of an internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 58-195011, etc., a primary side carburetor that guides air-fuel mixture from a primary side carburetor and a secondary side carburetor to two intake valves of each cylinder, respectively. The passage and the secondary passage are provided with a primary control valve and a secondary control valve that open and close in response to increases and decreases in load, and the primary control valve and the secondary control valve penetrate the primary passage and the secondary passage. It is fixed to a control rod installed in such a manner.

Conventionally, such a control rod, that is, a rotating shaft, is positioned in the axial direction and prevented from coming off by a positioning pin device as shown in FIGS. 5 and 6.

These positioning pin devices are provided with an annular groove 3 on the circumference of the rotating shaft 2 in the bearing portion 1, respectively.
The positioning pins 6 and 7 are press-fitted into the positioning pin mounting holes 4 and 5 and inserted into the groove 3.

<Problems to be solved by the invention> By the way, in such a positioning pin device, when the rotating shaft 2 receives an axial load, that is, a thrust load, the inner surface of the groove 3 of the rotating shaft 2 and the positioning pin 6, 7 is in line contact, there is a problem that the surface pressure is high and the degree of wear of the groove 3 and the positioning pins 6 and 7 on the contact surface is high.

As a result, the material for forming the positioning pins 6 and 7 has to be made of a material with excellent wear resistance, resulting in an increase in manufacturing costs.

The present invention was devised in view of these conventional problems, and it solves the above conventional problems by implementing a planar contact between the inner surface of the groove of the rotary shaft and the locating pin. It is an object of the present invention to provide a positioning pin device for a rotating shaft that can be attached to a proper position in a groove of the rotating shaft.

<Means for Solving the Problems> For this reason, the present invention provides a groove around the rotating shaft in the bearing, and a groove is provided at the tip of the positioning pin that is press-fitted into the positioning pin mounting hole of the bearing. While forming a plane part that makes plane contact with the inner surface of the groove,
A key groove extending in the axial direction of the positioning pin and having approximately the same width as the groove on the circumference of the rotating shaft is provided on the inner circumferential surface of the positioning pin mounting hole, and the flat part of the positioning pin is enlarged to fit into the key groove. A guide part to be inserted is provided.

<Function> When the positioning pin is installed, the guide part of the flat part of the pin is inserted into the keyway of the pin installation hole and the positioning pin is press-fitted into the pin installation hole, so that the flat part is attached to the circumferential part of the rotating shaft. is properly positioned in the groove and comes into planar contact with the inner surface of the groove.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4.

In FIG. 1, an annular groove 12 is formed around the rotating shaft 11 within the bearing portion 10. As shown in FIG. This groove 1
2, that is, the shaft portion 12 having a smaller diameter than the rotating shaft 11.
a is formed concentrically with the rotating shaft 11. A positioning pin mounting hole 13 is formed in the bearing portion 10 and extends perpendicularly to the center of the rotating shaft 11 from an outer peripheral position corresponding to the groove 12 . The inner peripheral surface of this positioning pin mounting hole 13 has a positioning pin 1 which will be described later.
A key groove 15 is provided which extends in the axial direction of the rotary shaft 11 and has substantially the same width as the groove 12 around the rotating shaft 11. As shown in FIG. 2, the positioning pin 14 that is press-fitted into the positioning pin mounting hole 13 is composed of a shaft portion 14A having a circular cross section and serving as a press-fit portion, and a flat portion 14B formed at the tip of the shaft portion 14A.

A flange portion 14a having a larger diameter than the shaft portion 14A is formed at the rear end of the shaft portion 14A, and when the positioning pin 14 is press-fitted, the flange portion 14a is locked to the outer peripheral surface of the bearing portion 10 for positioning. pin 14
The press-fit position is now regulated. The flat portion 14B is formed in the groove 1 when the positioning pin 14 is press-fitted.
2 and is in planar contact with the inner surface of the groove 12, and is formed in a substantially U-shape with a notch groove 14b into which the shaft portion 12a forming the inner bottom of the groove 12 is inserted with a gap. There is.

One of the two opposing sides of the U-shape of the flat portion 14B is provided as a guide portion 14c that is enlarged outward and fitted into the keyway 15.

In this configuration, when attaching the positioning pin 14, the groove 12 on the circumference of the rotary shaft 11 is correctly set at the center of the positioning pin attachment hole 13, and the guide portion 14c of the positioning pin 14 is fitted into the keyway 15 and inserted. When the shaft portion 14A reaches the positioning pin mounting hole 13, the positioning pin 1
4, the flat portion 14B is inserted into the groove 12 and makes plane contact with the inner surface of the groove 12.

According to the above configuration, the positioning pin 14 and the groove 1
2. Since it is possible to make plane contact with the inner surface,
Groove 1 on the contact surface can reduce surface pressure.
2 and the positioning pin 14 can be prevented from being worn out.

As a result, aluminum, resin, or sintered alloy can be used as the material for forming the positioning pin 14, making it easy to manufacture and reducing cost.

In particular, the guide portion 14 of the positioning pin 14
Since the positioning pin 14 is press-fitted while guiding the positioning pin 14 into the key groove 15, the plane part 14B and the inner surface of the groove 12 are kept correctly parallel, and the plane part 14B and the groove 1
2 and the inner surface are in proper planar contact, the above-mentioned wear prevention effect can be further enhanced, and reliability is high.

Next, another embodiment of the present invention is shown in FIGS. 3 and 4.

These embodiments differ from the conventional examples shown in FIGS. 5 and 6 in that the shaft portion forming the inner bottom of the groove 3 of the rotating shaft 2 is concentric with the rotating shaft 2 and formed to have a uniform circular cross section. This was done in order to solve the problem that the rotary shaft 2 is bent and torsionally deformed due to the fact that it is weak in strength.

That is, in FIG. 3, the rotating shaft 21 rotates within a rotation angle range of approximately 90 degrees. The inner bottom surface of the groove 22 on the circumference of the rotating shaft 21 is approximately parallel to the axial direction of the positioning pin 24 at the rotation end position of the rotating shaft 21 in the rotation range.

In this case, the groove 22 is formed by cutting out an approximately 270° angle range on the outer peripheral surface of the rotating shaft 21 in a substantially crescent shape, and the inner bottom of the groove 22 is a flat surface at the rotation end position of the rotating shaft 21. a plane a that is close to and parallel to the inner surface of the notch groove 24b of the portion 24B on the guide portion 24c side;
b, and an arcuate surface c that is formed concentrically with the center of the rotating shaft 21 and continues to the planes a and b.

According to this configuration, the cross-sectional area of the shaft portion 22a remaining after the groove 22 is formed in the rotating shaft 21 can be increased, and it is possible to prevent the rotating shaft 21 from bending or torsionally deforming. .

In the case shown in FIG. 4, the flat surfaces a and b of the inner bottom surface of the groove 22 are the guide portion 2 of the notched groove 24b of the flat portion 24B.
4c side inner surface, and in this case, a circular arc surface c continuous to the planes a and b is machined at a center eccentric with respect to the center of the rotating shaft 21.

According to this configuration, the rotating shaft 21 is at the rotation end position, and the planes a and b are in the guide portion 2 of the notched groove 24b.
Since the rotating shaft 21 is positioned in the rotational direction by contacting the inner surface on the 4c side, there is an advantage that positioning operation in the rotational direction outside the rotating shaft 21 can be eliminated.

<Effects of the invention> As explained above, according to the invention, a flat part is formed at the tip of the locating pin that is press-fitted into the locating pin mounting hole of the bearing section, making plane contact with the inner surface of the groove on the circumference of the rotating shaft. Since the positioning pin and the inner surface of the groove can be brought into plane contact with each other, the surface pressure can be lowered, and wear of the groove and the positioning pin on the contact surface can be prevented, and as a result, The manufacturing cost associated with forming the positioning pins can be reduced.

In particular, since the positioning pin is press-fitted while the guide part of the positioning pin is guided into the key groove, the flat part and the inner surface of the groove come into proper planar contact, and the above-mentioned wear prevention effect can be further enhanced. This has a great practical effect of increasing reliability.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a positioning pin device for a rotating shaft according to the present invention, where A is a front sectional view and B is a sectional view.
2 is a perspective view showing the structure of the positioning pin in the above device, and FIGS. 3 and 4 show other embodiments of the present invention, respectively. In the figures showing examples, A is a side sectional view and B is a side sectional view, respectively.
5 is a diagram showing an example of a conventional positioning pin device for a rotating shaft, and FIG.
A is a front sectional view, B is a perspective view showing the structure of the positioning pin, and FIG. 6 is a diagram showing another conventional example, A is a front sectional view, and B is a EE sectional view of A. 10... Bearing part, 11, 21... Rotating shaft, 1
2, 22... Groove, 12a... Shaft, 13... Locating pin mounting hole, 14, 24... Locating pin,
14A...Shaft part, 14B, 24B...Plane part, 1
4c, 24c...guide section, 15...keyway.

Claims (1)

[Claims for Utility Model Registration] (1) A groove is provided on the circumference of the rotating shaft in the bearing, and the inner surface of the groove on the circumference of the rotating shaft is provided at the tip of the locating pin that is press-fitted into the locating pin mounting hole of the bearing. A key groove is formed on the inner circumferential surface of the positioning pin mounting hole and extends in the axial direction of the positioning pin and has approximately the same width as the groove on the circumference of the rotating shaft. 1. A positioning pin device for a rotary shaft, characterized in that a guide portion is provided by enlarging a plane portion and fitting into the keyway. (2) The rotary shaft rotates in a rotation angle range of approximately 90°, and at the rotation end position of the rotary shaft in the rotation range, the bottom surface of the groove on the circumference of the rotary shaft is approximately parallel to the axial direction of the positioning pin. Utility model registration claim No. 1 characterized in that they are constructed in parallel
The positioning pin device for the rotating shaft described in (1).