JPH0435615Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a joint, and particularly relates to a fitting structure between a boss portion of the joint and a rotating shaft.

[Conventional technology]

Conventionally, the fitting structure of the boss part of a gear is, for example, as shown in Figures 555 and 821 of "Description Design Method (Volume 2)" by Yoshiro Ogawa published by Sangyo Tosho Co., Ltd. One surface that fits is a single tapered surface.

The structure of a gear having such a configuration is shown in FIG.

However, in a gear having a fitting surface of the boss portion formed of only a single tapered surface, when used fixed to the rotating shaft 1, the small diameter portion 8b is formed at the tip of the rotating shaft 8. The nut 4 is screwed into the threaded part 8c cut between the holes and firmly tightened to fix the nut 4. Due to this tightening, the tapered shaft part 8a of the rotary shaft 8 moves to the left in the figure, and as a result, the boss part The tapered surface that comes into contact with the tapered shaft portion 8a is subjected to a force exerted by the outer circumferential surface of the tapered shaft portion 8a to spread the tapered surface outward. On the other hand, since the small diameter portion 8b of the rotating shaft 8 does not come into contact with the tapered surface, no force that tries to widen the tapered surface toward the outer circumference is applied to the tapered surface corresponding to the small diameter portion 8b. Therefore, when used in this state for a long time, the tapered surface may become stepped in shape due to compositional deformation at the boundary between the portion that contacts the tapered shaft portion 8a and the portion that opposes the small diameter portion 8b. In that case, when the joint 1 is removed and fixed to the rotary shaft 8 again, there is a problem that play occurs in the tapered fitting portion and it cannot be fixed accurately.

In addition, as a connection between the rotating shaft and the boss part,
In the conventional example described in Publication No. 91924, the rotating shaft has a tapered part and a straight part, and the boss part also has a tapered surface facing the tapered part of the rotating shaft and a straight surface facing the straight part of the rotating shaft. is formed.

However, even with the structure described in JP-A-58-91924, if the boundary between the tapered part and the straight part of the rotating shaft faces the tapered surface of the boss part due to manufacturing errors, etc. In this case, there is a risk that the stepped portion on the tapered surface of the boss will be plastically deformed due to the boundary, and the same problem as described above still remains unsolved.

[The problem that the idea attempts to solve]

The present invention has been devised in view of the above points, and is a joint having a boss part that fits on a rotating shaft having a tapered shaft part and a small diameter part, and the joint boss part has the taper shaft part and a small diameter part. The object of the present invention is to prevent the composition of the stepped portion from being deformed due to the boundary between the stepped portion and the portion.

〔composition〕

In order to achieve the above object, the joint of the present invention has a tapered surface that contacts the tapered shaft of the rotating shaft except for the small diameter end of the boss, and a tapered surface that is provided on the small diameter end side of the tapered surface of the rotating shaft. A configuration is adopted in which a straight surface is formed facing the small-diameter end of the tapered shaft and the small-diameter portion of the rotating shaft.

[Effect]

By adopting the above configuration, the joint of the present invention can:
Since the boundary between the tapered shaft part and the small diameter part of the rotary shaft always faces the straight part of the boss part, even if the relative position between the boundary of the rotary shaft and the boss part changes due to assembly, the above boundary Compositional deformation of the boss portion due to this can be reliably prevented.

[Effect of idea]

Therefore, according to the joint of the present invention, even when the boss section is removed from the rotating shaft and then reassembled, the tapered surface of the boss section always comes into close contact with the rotating shaft, which prevents looseness during assembly. do not have.

Furthermore, in the present invention, by forming a fitting inner surface that discharges in the axial direction on one end surface of the joint, and forming a fitting outer surface that fits and fits with the fitting inner surface of the adjacent joint on the other end surface, a large number of It is possible to hold the joints stacked on top of each other at once. In that case, it is possible to significantly improve the production efficiency of processing such as gear cutting.

〔Example〕

Hereinafter, the present invention will be explained based on examples. Figures 2 and 4 relate to the first embodiment of the present invention; Figure 2 is a sectional view taken along the central axis during gear cutting of the present invention; Figure 4 is a sectional view of the central axis during use of the present invention. FIG.

First, the configuration will be explained. In FIG. 2, a boss portion 2 located at the center of a steel joint 1
has a conical tapered surface that fits with, for example, a tapered shaft portion of a camshaft of an injection pump, and a straight surface 3 having a width of about 4 mm.

In addition, in FIG. 2, a state in which a plurality of joints are held and fixed by a processing jig during gear cutting is shown by imaginary lines.

FIG. 4 shows the state in which the joint 1 is attached to the rotating shaft 8. When the joint 1 is used, the tapered surface of the boss part fits and fits with the tapered shaft part 8a, and the straight surface 3 of the boss part fits on the rotating shaft part 8a. The small diameter portion 8b and the boundary between the small diameter portion 8b and the tapered shaft portion 8a are fitted to correspond to each other.

Next, the effect will be explained. In FIG. 2, the processing jig has a cylindrical supporting cylindrical shaft 5a that is slidably fitted to the straight surface 3 of the joint 1 without any gaps, and the straight surface 3 of the joint 1 is attached to the supporting cylindrical shaft 5a. By fitting, centering of the joint can be ensured. After sandwiching a plurality of joints 1 (usually about 5 to 7 pieces depending on the capacity of the gear cutting plates), the supporting cylindrical shaft 5a
After the nut 4 is screwed into the screw attached to the tip of the joint and tightened to securely fix the joint, gear cutting is performed using a gear cutting plate to form a tooth surface 1a on the outer periphery of the joint.

In FIG. 4, the nut 4 is strongly tightened to the threaded portion 8c at the tip of the rotating shaft 8 while being fitted with the tapered surface of the boss portion and the tapered surface 8a of the rotating shaft 8. is fixed to the rotating shaft. Therefore, since the small diameter portion 8b of the rotating shaft 8 always faces the position of the straight surface 3, the tapered surface is prevented from being formed into a stepped shape due to tightening.

Next, the illustration in FIG. 3 will be explained. FIG. 3 is a sectional view taken along the central axis of the second embodiment, and the imaginary line shows the state in which it is held and fixed by the processing jig 5 during gear cutting. In this example, a fitting inner surface 6 and a fitting outer surface 7 are provided to ensure that the joint 1 is overlapped and held.

[Brief explanation of drawings]

Figure 1 is a sectional view along the central axis of a conventional joint, Figure 2 is a sectional view along the central axis during processing of the first embodiment of the present invention, and Figure 3 is the center of the second embodiment of the present invention. It is a cross-sectional view taken along the axis, and the imaginary line shows the state in which it is held and fixed by a processing jig during processing.
FIG. 4 is a sectional view taken along the central axis of the first embodiment of the present invention in use. 1...Joint, 2...Tapered surface, 3...Straight surface, 8...Rotating shaft.

Claims (1)

[Claims for Utility Model Registration] (1) Fitted onto a rotating shaft having a tapered shaft portion 8a and a small-diameter portion 8b provided at the small-diameter end of this tapered shaft portion, and rotationally driven by the rotating shaft. The joint has a boss portion formed on its inner periphery with a fitting surface with the rotating shaft, and the small diameter end of the boss portion is connected to the tapered shaft portion 8a of the rotating shaft. a straight surface 3 provided at the small-diameter end of the tapered surface 2 and facing the small-diameter end of the tapered shaft portion 8a of the rotating shaft and the small-diameter portion 8b of the rotating shaft; A joint characterized by forming. (2) The joint is characterized in that one end surface thereof is formed with a fitting inner surface that protrudes in the axial direction, and the other end surface thereof is formed with a fitting outer surface that fits and fits with the fitting inner surface of the adjacent joint. A joint according to claim 1 of the utility model registration claim.