JPH0810940Y2 - Coupling structure of bobbin and yoke of small plunger - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to, for example, aperture control and shutter control of cameras, tape rotation direction control and start and stop control of audio equipment and VCRs, home appliances and other power supplies. The present invention relates to a coupling structure of a bobbin and a yoke in a small plunger having a structure in which a part of the yoke is inserted into the bobbin, which is used in a device requiring the.

(Problems to be Solved by Conventional Techniques and Inventions) FIG. 10 is a cross-sectional view showing an example of a fastening structure of a bobbin 1 and a yoke 2 in a conventional small plunger, in which a foot portion 2b of the yoke 2 is attached to the bobbin 1. The yoke 2 and the bobbin 1 are fastened by being inserted into the yoke insertion cylinder portion 1a having a rectangular cross section at the center and adhering the portion of the yoke 2 opposite to the movable piece 3 suction surfaces 2a and 2i with the adhesive 4. Was there. The movable piece 3 made of a magnetic material is used in combination with a link, a lever, a pin, and the like. To describe an example of a usage mode, the coil 5 wound around the bobbin 1 is energized to attract the movable piece 3. When the energization is stopped from the state in which the movable piece 3 is attracted by the force of the spring 6,
When some work is performed apart from 2a and 2i and the movable piece 3 is brought closer to the suction surface 2a by an external force while the coil 5 is energized, the movable piece 3 is re-sucked. In the figure, 7 is a mounting hole for the yoke 2 through which a screw or the like is inserted, and 8 is a terminal for connecting both ends of the coil 5 and a lead wire.

However, if the yoke 2 and the bobbin 1 are fastened with the adhesive 4 as shown in FIG. 10, the yoke 2 may come off the bobbin 1 and cause a failure due to variations in the amount of the adhesive 4 and the application place. There was a problem. If an adhesive having a large fluidity is used in order to reduce the variation, the adhesive moves through the gap between the yoke 2 and the yoke insertion tube portion 1a of the bobbin 1 due to the permeation action. There is a problem in that it flows out to the one-sided adsorption surface 2a and causes defective adsorption characteristics.

Further, when the adhesive 4 is used, it takes time and a heating device to dry the adhesive 4 (for example, it is heated at 80 ° C. for 30 minutes), and after the bonding with the adhesive, the work such as inspection cannot be performed immediately. However, there was a problem that it was inefficient.

In order to solve the above problems, the present inventors have developed a fastening structure shown in FIGS.
It was disclosed as No. 11. In this fastening structure, a through hole or a concave portion 1f is formed in the collar 1c on the side opposite to the movable side of the bobbin 1, and a convex portion 2e is provided near the end of the insertion portion of the yoke 2 into the cylindrical portion 1a. From the state, the yoke 2 is pushed into the cylindrical portion 1a of the bobbin 1 in the direction of the arrow b, and at the same time, the folded-back portion 2c of the yoke 2 is pushed into the groove 1d provided in the bobbin 1, and accordingly, the convex portion 2e is formed. Fit into the through hole or recess 1f,
The yoke 2 is fastened to the bobbin 1 by elastically locking the convex portion 2e to the plate-shaped portion 1h forming the concave portion 1f.

However, for example, the thickness (L dimension in Fig. 11 (B)) is 3 mm.
If you try to realize such a small thing, the convex part 2e and the concave part
The size of 1f is inevitably small, which causes a problem that it is difficult to secure a predetermined bonding strength and pin 8 pull-out strength.

The present invention solves the above-mentioned problems and provides a bobbin-yoke coupling structure for a small-sized plunger that enables easy and reliable coupling between the bobbin and the yoke even when a smaller-sized plunger is realized. The purpose is to

(Means for Solving the Problem) In order to achieve this object, the present invention provides a small plunger in which one or both of the legs of a U-shaped yoke are inserted into one or a pair of cylindrical portions of a resin bobbin. In the above-mentioned bobbin, a flange on which the folded-back portion of the yoke is fitted is provided in the collar on the side opposite to the movable side, and a projection is provided on at least one of the opening-side facing wall surfaces of the groove, and the folded-back portion of the yoke is It is characterized in that it is pushed into the groove and the shoulder portion of the yoke return portion is locked to the projection.

(Operation) In the present invention, when the yoke is pushed into the bobbin, the folded-back portion of the yoke pushes open both sides of the groove of the bobbin to deflect the portions, and the protrusion formed on the wall facing the groove is folded back. When the folded-back portion is passed over and the folded-back portion is housed in the groove, both sides of the groove are elastically restored and the protrusions engage with the shoulders of the yoke, preventing the yoke from coming off the bobbin. Is done.

(Embodiment) FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG.
A sectional view corresponding to FIG. 2, showing a state in which the yoke is pushed into the bobbin, is a front view and a bottom view of the bobbin of the embodiment, respectively. 1 to 5, the same reference numerals as those in FIGS. 10 and 11 indicate parts or portions having the same function.

1 to 5, the bobbin 1 is made of a synthetic resin molded body and has a flange 1b at one end of a yoke insertion tubular portion 1a having a rectangular cross section and a wide flange 1c at the other end. The Tsuba 1c
The terminal 8 is planted in. The flange 1c has an opening corresponding to the inside of the cylindrical portion 1a, and has a yoke fitting groove 1d (fourth width) which is approximately the same width as the width W (see FIG. 3) inside the cylindrical portion 1a.
(See the figure) is formed. Further, on the opening side of the opposing wall surface of the groove 1d, there are formed protrusions 1j projecting from each other on their respective side wall surfaces. On the other hand, inclined surfaces (which may be R surfaces) 2j are formed on both sides of the inner surface of the folded-back portion 2c of the yoke 2 in order to facilitate pressing between the protrusions 1j.

In this configuration, as shown in FIG. 1, by inserting the foot portion 2b of the yoke 2 into the tubular portion 1a of the bobbin 1 and further pushing in the yoke 2 from the state of the two-dot chain line a as shown by the arrow b, As shown in FIG. 3, the folded-back portion of the yoke 2
2c pushes the projections 1j on the opposite wall surface of the groove 1d of the bobbin 1 toward both sides of the inclined surface 2j or the folded back portion 2c as shown by the arrow c to deflect both sides of the groove 1d, and then the groove 1d. When the folded-back portion 2c of the yoke 2 goes over the protrusion 1j formed on the opposing wall surface of the yoke 2 and the folded-back portion 2c is accommodated in the groove 1d, both side portions of the groove 1d are elastically restored and the yoke 2 By engaging the projection 1j with the shoulder 2k of the bobbin 1, the yoke 2 is prevented from coming off the bobbin 1.

In this way, when the protrusion 1j is provided on the opposing wall surface of the groove 1d and the protrusion 1j is joined by pushing the folded portion 2c of the yoke 2 while opening it, the portion where the protrusion 1j is formed is, so to speak, a free end. Since the push-opening can be easily performed, the height h (see FIG. 5) of the protrusion 1j can be increased by the amount of the push-opening. Therefore, when the protrusion 1j is returned, the yoke 2 The shoulder 2k of the projection 1j has a relatively large size.
Even if the plunger is small as a whole, it can be securely prevented from coming off. Also, the protrusion
It is not necessary to make the dimensional accuracy of the 1j, the groove 1d, etc. so high.

In the above-described embodiment, an example is shown in which the terminals 8 are attached so that the terminals 8 face the same direction with respect to the plane formed by the legs 2a and 2d of the yoke 2 and the folded-back portion 2c. As shown in the drawings (FIG. 6 is a side sectional view, FIG. 7 is a sectional view taken along line BB in FIG. 6, FIG. 8 is a bottom view of the bobbin, and FIG. 9 is a front view of the bobbin), The terminals 8 may be attached so that the terminals 8 are oriented in a direction perpendicular to the plane formed by the legs 2a and 2d of the yoke 2 and the folded-back portion 2c. Further, in the embodiment of FIGS. 6 to 9, the protrusion 1j is formed only on one of the opposing wall surfaces of the groove 1d, but since the protrusion 1j can be formed high, the protrusion 1j is provided only on one side. Even with this, a sufficient retaining effect can be exerted.

(Effects of the Invention) Since the bobbin-yoke fastening structure according to the present invention has a structure in which a groove is provided in the bobbin and the projection is joined by pushing it open at the folded-back portion of the yoke, The formed part is, so to speak, a free end, and push-opening can be performed easily, so the protrusion height of the protrusion can be increased,
Therefore, even if it is small, it can be securely prevented from coming off. In addition, since the protrusion height of the protrusion can be increased,
Even if there are some variations in product dimensions such as protrusions and grooves, a reliable yoke removal preventing effect can be obtained. Therefore, it is not necessary to make the dimensional accuracy so high, processing becomes easy, and it contributes to cost reduction.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 shows a state in which a yoke is pushed into a bobbin in the embodiment. 2 is a sectional view corresponding to FIG. 2, FIGS. 4 and 5 are front and bottom views of the bobbin of the embodiment, respectively, FIG. 6 is a side sectional view showing another embodiment of the present invention, and FIG. FIG. 8 is a sectional view taken along the line BB in FIG. 8, FIG. 8 and FIG. 9 are bottom views of the bobbin of the embodiment, respectively. FIG. 10 is a side sectional view showing an example of a conventional structure, and FIG. Side sectional view showing another example of the conventional structure, the same (B)
FIG. 3 is a front view of the same (A). 1: Bobbin, 1a: Cylindrical part, 1b, 1c: Tsuba, 1d: Groove, 1j: Protrusion, 2: Yoke, 2a, 2i: Adsorption surface, 2b, 2d: Foot part, 2c: Folding part, 2j : Inclined surface, 2k: Shoulder, 3: Movable piece, 5: Coil, 7: Mounting hole, 8: Terminal

Claims (1)

[Scope of utility model registration request] 1. One or both of the legs of the U-shaped yoke,
In a small plunger that is inserted into one or a pair of cylindrical parts of a resin bobbin, a groove on which the folded-back part of the yoke is fitted is provided in a flange of the bobbin opposite to the movable side, and the opening side of the groove is opposed. A bobbin and a yoke for a small plunger, characterized in that a protrusion is provided on at least one of the wall surfaces, the folded-back portion of the yoke is pushed into the groove, and the shoulder portion of the yoke-folded portion is locked to the protrusion. Bond structure.