JPH04359643A - Resin-molded bobbin - Google Patents

Abstract

PURPOSE:To facilitate flow of resin into a pole inserting hole, generation of a gap of a boundary between a bobbin and the resin, and managements of size, molding conditions of the bobbin upon generation of the gap. CONSTITUTION:One or several grooves 1e are formed on a periphery of holes 1c for inserting poles at both outer sidewalls of a bobbin 1, and flow of resin 3 to the holes 1c, generation of a gap of a boundary 1d between the bobbin l and the resin 3 are prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded bobbin for a molded motor in which a bobbin is used to wind wires and then molded.

0002

2. Description of the Related Art In general, various efforts have been made to reduce the number of defective products and improve workability during molding of resin mold bobbins.

[0003] The conventional technology will be explained below with reference to FIG. As shown in the figure, the bobbin 1 is wound with a wire 2 and then set in a lower die 6 of a molding die, then clamped by an upper die 5, and resin 3 is injected and molded. Here, when setting the bobbin with the winding loose on the lower die 6, the bobbin 1 is positioned on the guide post 6a provided on the lower die 6.
This is done by fitting and setting the magnetic pole insertion holes 1c of both outer walls 1a and 1b of the , but in order to improve workability, a clearance 4 should be provided between the guide post 6a and the magnetic pole insertion hole 1c of the bobbin 1. is necessary. On the other hand, in molding, the clearance 4 of the magnetic pole insertion hole c of the bobbin 1
If resin flows into the mold, it will be difficult to insert the magnetic pole after molding. Therefore, in order to prevent this, the total length of the bobbin 1 is made larger than the mold dimensions as shown in the dashed line in advance, and the bobbin 1 is molded under pressure by the mold during molding. The resin is prevented from flowing into the clearance 4 by the molding pressure from the boundary surface 1d between the mold and the mold.

0004

However, in the conventional configuration described above, it is very difficult to set the overall length 1h' of the bobbin 1. In other words, if the total length 1h' is made too large, resin can be prevented from flowing into the clearance 4, but since the bobbin 1 is deformed under pressure by the mold more than necessary, the upper mold 5 is
When the bobbin is opened, the pressurized portion of the bobbin tends to return to its original state, that is, springback occurs, so that the bobbin 1 and the resin 3 are not brought into close contact with each other at the boundary 1d, resulting in problems such as a gap. Furthermore, if the overall length 1h' of the bobbin 1 is too small, the pressure applied to the mold will be weakened, and the resin will flow in due to the molding pressure and reach the clearance 4, which will impede the insertion of the magnetic pole as described above. Therefore, strict control is required for the bobbin total length 1h', including dimensional variations and selection of materials, and strict control is also required for molding conditions such as molding pressure.If the conditions cannot be satisfied, the above There is a problem that such problems occur.

[0005] The present invention solves the above-mentioned problems, and provides a resin that facilitates the flow of resin into the magnetic pole insertion hole during molding, the generation of a gap at the boundary between the bobbin and the resin, and the various management associated therewith. The purpose is to provide mold bobbins.

[0006]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a resin molded bobbin in which a bobbin with a wire wound thereon is molded in resin. One or several grooves are provided around the periphery.

[0007]

[Operation] In the above structure, the present invention provides a groove around the magnetic pole insertion hole of the bobbin, so that even if resin flows from the boundary, it will flow into the groove and be absorbed, thereby preventing it from flowing into the clearance. can. Furthermore, since the overall length of the bobbin can be made smaller than before, the springback of the bobbin can be reduced and the generation of gaps between the bobbin and the resin can be prevented.

[0008]

Embodiment An embodiment of the present invention will be described below with reference to FIG. Note that the same numbers are used for the same constituent members as those explained in the conventional example.

As shown in the figure, both outer walls 1a of the bobbin 1
, 1b, except that one or more grooves 1e are provided around the hole 1c into which the magnetic poles of the magnetic poles 1b are inserted.

By providing the groove 1e in the bobbin 1, even if the resin 3 flows from the boundary part 1d during pressure molding, the groove 1e
Since it flows into the interior and is absorbed, it is possible to prevent it from flowing up to the clearance 4. In addition, since the total length 1h of the bobbin 1 can be made smaller than before, the springback of the bobbin 1 due to pressurization can be reduced, and the bobbin 1 and the resin 3
It is also possible to prevent the generation of gaps between the two.

[0011]

As is clear from the above description of the embodiments, the present invention provides grooves at one or several places around the holes in both outer walls of the bobbin into which the magnetic poles are inserted, thereby making it possible to connect the bobbin to the mold. Even if resin flows from the boundary, it will be absorbed into this groove, thereby preventing it from flowing into the clearance. In addition, taking this into consideration, the overall length of the bobbin can be made smaller in advance than before, which reduces the springback of the bobbin after molding, and prevents the occurrence of a gap between the bobbin and the resin. Therefore, there is an effect that there is more leeway in managing the dimensions of the bobbin and molding conditions than in the past, making it easier to manage.

[Brief explanation of the drawing]

[Fig. 1] Cross-sectional view of a resin mold bobbin according to an embodiment of the present invention when the mold is set

[Figure 2] Cross-sectional view of a conventional resin mold bobbin when the mold is set

[Explanation of symbols]

1 Bobbin 1c Hole for inserting magnetic pole 1e Groove 2 Winding wire 3 Resin

Claims (1)

[Claims] [Claim 1] A hole for inserting a magnetic pole is formed in the center,
A bobbin that is wound and resin-molded,
A resin molded bobbin having one or several grooves around the hole into which the magnetic pole of the bobbin is inserted.