JPH0218372Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to the improvement of resin gear devices, particularly those constructed by molding a polymer synthetic resin by filling and fixing a sleeve metal to the boss portion.

[Prior art]

Conventionally, there have been devices of this type as shown in FIGS. 2 to 7. In the figure, 1 is an internal gear device manufactured by the resin molding method as described later in FIGS. 3 a, b or 4 a, b, 2 is an internal gear gear,
3 is a boss portion to which the sleeve metal 4 is fixed with filler metal. The internal gear 1 may be formed by a multi-point gate resin molding method as shown in FIGS. 3a and 3b. In FIG. 3, reference numeral 5 indicates gates for resin molding provided at a plurality of locations, and after removing these portions, the internal gear device 1 shown in FIG. 2 is obtained. Next, FIGS. 4a and 4b show the case where the internal gear device 1 is manufactured using the direct gate method, in which a resin molding material is injected from the direct gate port 6, and the part is cut and removed. Thus, the internal gear device 1 is manufactured. Above, Figure 3 a, b
In addition to the shape shown in FIG. 5a, the sleeve metal 4 to be fixed with filler metal in FIGS. 4a and 4b has the shape shown in FIG. 5b. A sleeve metal 8 having parallel grooves 8a as shown in FIG. 5c has also been devised. Note that the protruding portion 7a and the groove 8a have a function of improving the adhesion with the resin and stopping the rotation direction of the supported rotating shaft. The sleeve metal 4, 7 or 8 is fixed to the boss portion 3a with filler metal as illustrated in FIG. 6, and the mold burrs at parts A and B shown in the figure are gradually removed to manufacture the internal gear device 1. and a case where the internal gear device 1 is obtained by removing the end face (direct gate opening) of the sleeve metal 4, 7 or 8 fixed to the boss portion 3a with filler metal (deletion of the direct gate opening) as explained in Fig. 7. There is.

The conventional device is as described above, and is shown in Fig. 4 a and b.
In the case of the direct gate method explained in , the pressurizing force of the resin, sleeve metal 4 [or 7,
8] Axial length tolerance (for metal molded products, ±
0.15mm/10mm (required per length), etc., if the gap in the mold is large, the resin may wrap around the metal edge, and as a result, it may not be possible to remove it sufficiently by single edge processing (Figure 7). Furthermore, in the example shown in Fig. 7, the axial adhesion between the sleeve metal 4 and the boss portion 3b is insufficient, causing the sleeve metal 4 to come off in the axial direction (toward the right in the figure). It had the drawback of falling. Furthermore, as shown in FIG. 6, when a step is provided to prevent the sleeve metal 4 from coming off in the axial direction, there are drawbacks such as the need for machining of this portion.

[Summary of the idea]

This idea was made to improve the above-mentioned drawbacks of the conventional technology, and was developed by extending grooves that do not reach both ends of the sleeve metal from both ends, as described below. The aim is to provide something with excellent effects.

[Example of idea]

An embodiment of this invention will be described below. In FIGS. 1a and 1b, 9 is a sleeve metal that is fixed with a filler metal when manufacturing a product similar to the internal gear device 1 by the direct gate method explained in FIG. Concave grooves 9a and 9b, which are parallel to the axial direction and do not reach both ends, are arranged on the surface so as to equally divide the circumference (in six places in the figure). The grooves 9a and 9b are formed in opposite directions and are arranged so as not to intersect with each other.

By doing this, when the internal gear device is resin molded using the direct gate method, the concave grooves 9a, 9
Resin is injected into b, and the resin in this part ensures that the sleeve metal 9 does not come off in the axial direction.Also, the gate removal process in the post-processing process can be done in a single process, making it inexpensive and reliable. This has the effect of producing an excellent molded product.

[Effect of idea]

As described above, according to this invention, a concave groove is provided on the outer circumferential surface of the sleeve metal that is molded and fixed to the gear device, and the resin mold is constructed using a direct gate method. This provides extremely excellent effects such as reliable stopping, easy fabrication of the device, low cost, and excellent reliability.

[Brief explanation of the drawing]

1a and 1b are a side view and a front view showing the appearance of the sleeve metal according to the embodiment of this invention, respectively, FIG. 2 is a sectional view of the conventional device, and FIG. 3a is the second
Figure 3b is a sectional view of Figure 3a, Figure 4a is a side view of another manufacturing method, and Figure 4b is a cross-sectional view of Figure 3a. 5a is a sectional view of the main components of the device shown in FIG. 2, FIGS. 6 and 7 are sectional views showing the main parts of the internal gear device for explaining the manufacturing method of the device shown in FIG. 2. In the figure, 1 is an internal gear device, 2 is an internal gear,
3 is the boss part, 4, 7, 8, 9 are sleeve metals,
5 is a gate, 9 is a direct gate opening, 7a is a protrusion, and 8a, 9a, and 9b are grooves. In addition,
In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] In a resin gear device integrally molded with a resin mold material and having a sleeve metal molded and fixed to a boss portion, the sleeve metal is provided on the outer peripheral surface of the sleeve metal and is parallel to and opposite to each other in the axial direction from both ends,
A resin gear device characterized by having a concave groove disposed halfway in the axial direction.