JPH0422979Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention relates to an injection-molded integral structural member, and more specifically, a synthetic resin or similar injection-molded material is injected around a round bar serving as an axis. The present invention relates to an injection molded integral structural member in which both parts are molded and integrally connected.

[Prior Art] A conventional injection molded integral structural member has a structure as shown in FIG. 3, for example.

In FIG. 3, 11 is a round bar serving as a shaft, and 12 is an injection molding material such as synthetic resin that is injection molded around the round bar 11. In FIG. And, 11a is a D-cut portion processed into the round bar 11 so that the round bar 11 does not come off from the injection molding material 12 or rotates relative to the injection molding material 12.

[Problems to be solved by the invention] As mentioned above, in the conventional injection molded integral structure member, when processing the round bar 11, the outer diameter of the round bar 11 is cut using a lathe, and the D-cut portion is cut. In order to form the D-cut portion 11a, the D-cut portion 11a was cut using a separate cutting machine, resulting in an unavoidable increase in the number of processing steps and the accompanying cost.

The present invention attempts to solve these problems.

[Means for solving the problem] Spiral grooves in different directions were formed on the round bar serving as the shaft.

[Operation] According to the present invention, cutting of the outer diameter of the round bar and cutting of the spiral groove can be performed only by lathe machining, so that costs can be reduced.
In addition, since the spiral groove is oriented in different directions rather than in one direction, it is more effective than the conventional D-cut.
Ensures prevention of slippage and rotation.

[Embodiment] FIG. 1 shows a first embodiment of the present invention. In Fig. 1, 1 is a round bar serving as an axis, and 2 is the round bar 1.
It is an injection molded material such as synthetic resin that is injection molded around the . And, 1a is a spiral groove formed in the round bar 1 with different directions, and in this embodiment,
The cross-sectional shape of the groove 1a is chevron-shaped.

In the injection molded integral structure member constructed as shown in FIG.
Processing a can be carried out using a lathe, and the round bar 1 generates a drag force due to the unevenness of the groove 1a against the force in the thrust direction, that is, the pull-out force.
Against the force in the rotational direction, a resistance force is generated due to the taper of the groove 1a in both the right-handed and left-handed helical directions.
However, it is reliably prevented from coming off or rotating.

FIG. 2 shows a second embodiment of the invention. In FIG. 2, 1b is a spiral groove formed in the round bar 1 in different directions, and in this embodiment, the groove 1b
The cross-sectional shape of is rectangular. Even with this configuration, the functions and effects are the same as in the case of FIG. 1.

[Effect of the invention] Since the round bar in the injection molded integral structural member of the present invention has spiral grooves in different directions, the contact area between the round bar and the injection molding material per unit length of the round bar increases. , the resistance due to friction increases, and the effect of preventing the round bar from rotating and coming off is improved. Moreover, since the round bar can be processed only with a lathe, the cost is reduced compared to the conventional D-cut process.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the first embodiment of the present invention;
FIG. 2 is a cross-sectional view showing the second embodiment, and the third
The figure is a sectional view showing an example of a conventional technique. 1...Round bar, 1a, 1b...Groove, 2...Injection molding material.

Claims (1)

[Scope of utility model registration request] A round bar serving as an axis has spiral grooves in different directions, and an injection molding material is injection molded around the spiral groove of the round bar, so that the round bar and the injection molding material are integrated. An injection-molded monolithic structural member characterized by being joined together.