JPS62148219A - Injection molding of gear - Google Patents

Abstract

PURPOSE:To average the orientation of a molding material and to improve the accuracy of shape dimension by setting more than one theft parts and ribs on a molded gear and more than one gates between ribs at every two intervals. CONSTITUTION:Theft convex parts 5, 5' and more than one ribs 6, 6 are radially set at a specified interval on both sides between a fixed tube 2 of the center and a ring part 4 having mating gears 3 on its outer circumference. More than one gates 7 are set at every two intervals between ribs 6, 6 set on the theft parts 5, 5'. When a molding material filled with additives such as glass and carbon fiber is packed in the cavity of a mold in molding of a gear, the flow of molten material is thereby branched and controlled to average the orientation.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention particularly relates to thermal O2 containing additives such as glass and carbon fibers.
This invention relates to a method for injection molding gears using T-plastic.

[Conventional technology]

In conventional injection molding, as shown in Figs.
A multi-point gate (C) is used to perform molding.

[Problem that the invention seeks to solve]

However, when forming a gear by the above conventional method, the fusion molding material containing glass and carbon fiber M'4 (as shown in Fig. 7) does not shrink due to orientation. , the spiral flow direction contracts. In particular, in the case of molding materials containing glass, carbon fibers, etc., there are problems such as increased deformation in the outer diameter in the direction between the gates and in the direction of the gates due to the orientation of the material itself. Prevention is extremely difficult.

The present invention aims to solve the above-mentioned problem, and aims to average out the orientation of the molding material and improve the accuracy of shape, size, etc.

[Means for resolving errors]

In order to achieve the above purpose, the invention is constructed as follows.

That is, the present invention provides heat 1 containing foil additives such as glass and carbon fibers.
In the injection molding of gears using plastic plastic materials, deformation of the gear external shape caused by the flow of the plasticized bath melt material in the metal and the orientation of its additives 1, fitting error #l 'Mi, in order to reduce the force, 4i number of fillets and ribs were provided on the molded gear, and (11 gates were set at 1t distance between each rib, and the shape of the m wheel was deformed.) This is an injection molding method for gears that is characterized by the fact that the flow of molten material is controlled in separate flows without shadows.

[Effect]

In injection molding of gears, when molding materials containing additives such as glass and carbon fibers are filled into the mold cavity, the flow of the bath melting material is controlled to be divided to equalize the orientation as shown in Figure 9. let

〔Example〕

In Figs. 1 to 3, the reference numeral (1) indicates a gear manufactured by the method of the present invention, which has an annular g (41) having a fixed tube part (2) provided in the center and meshing teeth (3) on the outer periphery. The number of ribs t61 + 61 (151 + t h y in the illustrated example) of meat stealing (!l!) are provided radially on the sides for a predetermined period of time.And in the present invention, Recess % (Each rib t6116 provided in 51151
A plurality of gates (77 (in the illustrated example, S) are provided at every other position between 1 and 2. Fig. This is a graph showing each deformation rate of gears manufactured using a 5-point gate.The graph shows the deformation rate of gears manufactured using a 5-point gate. The solid line indicates that of the present invention.

〔Effect of the invention〕

According to the present invention, the orientation of the molding material can be made uniform by providing the molded gear with a number of inner ribs and by setting the number of gates at every other position between the ribs. , a molded product that is satisfactory in terms of shape, functionality, and dimensions?
It is something that can be produced.

[Brief explanation of drawings]

Fig. 1 is a front view of a gear molded by the molding method according to the present invention, Figs. - and 3 are M/Fig. Orientation of molding material? :
Fig. 5 shows the correct UiI of the gear produced by the conventional molding method, and Fig. 6 shows the Fig. 5 ■-ffl gland.
FIG. 7 is a diagram showing the orientation of the molding material according to the conventional molding method, and FIG. G is a graph showing the deformation rate of molded products according to the present invention and the conventional example. (1) ~Gear, +51151 A-[! Part 1, (6)~
Rib, (7) ~ gate.

Claims (1)

[Claims] In the injection molding of gears using thermoplastic materials containing additives such as glass and carbon fibers, deformation of the outer shape of the gear and interference caused by the flow of the plasticized molten material within the mold and the orientation of the additive. In order to minimize errors, the molded gear is provided with multiple thin holes and ribs, and multiple gates are set at every other position between the ribs, so that the gear shape is melted so that it is not affected by deformation. A method for injection molding gears, characterized in that the flow of material is controlled in separate flows.