JPH0541361U - Resin mold bobbin - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent cracks from occurring in the molding resin when integrally molding a wound bobbin. [Structure] After the molding, when the upper die 4 and the lower die 5 are opened, the springback force of the bobbin 1 is applied by the knockout pins 6 and 7 applied to the protrusions 1b and 1c formed on both end surfaces of the bobbin 1. receive. Therefore, the force due to the spring back is not applied to the mold resin 3 and the generation of cracks can be prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a resin mold bobbin for a molded motor.

[0002]

[Prior Art]

 A conventional resin mold bobbin will be described with reference to FIGS. 2 and 3 by taking a stator of a mold motor as an example.

FIG. 2 is a sectional view of a molding die showing a state in which a resin mold bobbin is integrally molded, and FIG. 3 is a sectional view of the resin mold bobbin with a part cut away.

In FIG. 3, a conventional resin mold bobbin has a winding 2 formed on a bobbin 1 having a U-shaped cross section, in which annular projections 1a are formed on the front and rear of the inner peripheral portion, and the outer periphery of the bobbin 1 is covered with the molding resin 3. It is integrally molded so that

In FIG. 2, in order to mold the resin mold bobbin configured as described above, the bobbin 1 having the winding wire 2 is fixed between the upper die 4 and the lower die 5 of the molding die. . In order to prevent the molding resin 3 from flowing out at the time of molding, the depth of the cavity shown by the dimension line H is suppressed to be slightly lower than the free height of the bobbin 1. After molding, press both sides of the mold resin 3 with the knockout pins (Knock-0ut-Pin: mold releasing pin) 6 and 7 provided on the upper mold 4 and the lower mold 5, to form the upper mold 4 and the lower mold 5. Open, and then knockout pins 6 and 7 are opened to take out the resin-molded bobbin molded.

[0006]

[Problems to be solved by the device]

 However, in the structure as described above, when the mold is opened after molding, the bobbin 1 compressed between the upper mold 4 and the lower mold 5 springs back (in the direction of the arrow) and is provided on one upper mold 4. Since the knockout pin 6 thus pressed holds down the mold resin 3, the mold resin 3 is distorted, and cracks 3a are generated in the mold resin 3 at the corners of the annular protrusion 1a as shown in the side view of the resin mold bobbin shown in FIG. There was a problem that occurred. Incidentally, K in FIG. 4 is a knockout pin mark.

An object of the present invention is to solve the above problems and provide a resin mold bobbin in which cracks do not occur in the mold resin.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention provides protrusions at both end surfaces of the bobbin which the knockout pins hit during molding.

[0009]

[Action]

 According to the above configuration, since the protrusion of the bobbin is received by the knockout pin, the springback force of the bobbin at the time of molding does not act on the molding resin, so that cracking can be prevented.

[0010]

【Example】

 An embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a cross-sectional view of a mold showing a state in which the resin mold bobbin of this embodiment is integrally molded, and the members corresponding to those described with reference to FIG. The present embodiment, which is not described in detail, is different from the conventional example shown in FIG. 2 on both end surfaces of the bobbin 1 facing the knockout pins 6 and 7 of the upper mold 4 and the lower mold 5, respectively. The point is that the protrusions 1b and 1c having a height substantially equal to the thickness of the molding resin 3 are formed.

The behavior of integrally molding the resin mold bobbin thus configured will be described. When the upper die 4 and the lower die 5 are opened after molding, the force that the bobbin 1 tries to spring back (in the direction of the arrow A) is received by the knockout pins 6 and 7 of the protrusions 1b and 1c. No power is applied to 3. After that, the knockout pins 6 and 7 are opened, and the integrally molded resin mold bobbin is taken out.

As described above, according to the present embodiment, since the force due to the spring back of the bobbin 1 at the time of molding is not applied to the mold resin 3, it is possible to suppress the occurrence of the crack 3a as shown in FIG.

[0014]

[Effect of the device]

 As described above, according to the present invention, since the protrusion of the bobbin is received by the knockout pin, cracks in the mold resin due to springback during molding are prevented, and a resin mold bobbin with good yield is provided. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold for molding a resin mold bobbin according to the present invention.

FIG. 2 is a cross-sectional view of a metal mold during molding of a conventional resin mold bobbin.

FIG. 3 is a sectional view showing a resin mold bobbin with a part cut away.

FIG. 4 is a side view of the resin mold bobbin of FIG.

[Explanation of symbols]

1 ... Bobbin, 1a ... Annular projection, 1b, 1c ... Projection part,
2 ... Winding, 3 ... Mold resin, 4 ... Upper mold, 5 ...
Lower mold, 6, 7 ... Knockout pin.

Claims (1)

[Scope of utility model registration request] 1. A resin mold bobbin obtained by integrally molding a wound bobbin with a resin, wherein protrusions are provided at both end surface portions of the bobbin that hit the knockout pins during molding.