JPH0224192Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention relates to an electromagnetic switch, and particularly relates to a mounting structure for an electromagnetic coil and a fixed core.

[Prior art and its problems]

In this type of electromagnetic switch, the electromagnetic coil is often replaced with a new electromagnetic coil or an electromagnetic coil that meets the rating when the electromagnetic coil burns out during use or when the operating voltage is changed. In such a case, in a conventional electromagnetic switch, when the electromagnetic coil is removed for replacement, the pressing spring that presses down the fixed iron core may fall off together with the electromagnetic coil, and in some cases may be lost. This type of conventional device is shown in Figs. 7 to 9, in which Fig. 7 is a front sectional view of the electromagnetic switch, Fig. 8 is a side sectional view of the same, and Fig. 9 is a centering view of the same restraining spring. FIG. In the figure, 1 is a movable contact support, 2 is a connecting plate, 3 is a movable iron core, 4 is an electromagnetic coil, 5 is a pressing spring, 6 is a connecting rod, 7 is a fixed iron core, 8 is a lower case, and 11 is an upper case. As is clear from FIG. 9, the pressing spring 5 connects the electromagnetic coil 4 with the connecting rod 6.
It is inserted between the lower case 8 and the fixed iron core 7 to press it against the lower case 8, but when the electromagnetic coil 4 is pulled upward, the pressing spring 5 also easily falls off. Furthermore, a connecting rod 6 is used to fix the fixed iron core 7 and the fixed iron core to the lower case 8 when the pressing spring 5 falls off.
There was a drawback that the electromagnetic coil 4 was easily separated and the replacement work of the electromagnetic coil 4 was extremely complicated.

Tokkosho proposed a way to eliminate the above-mentioned difficulties.
It is disclosed in the specification of No. 55-46613. That is, according to the specification, as shown in FIGS. 10 and 11, in order to press and hold the fixed core 7 of the electromagnetic switch against the bottom of the lower case 8, a hole is provided in the lower part of the fixed core 7. The final turn or end turn 5a, which has a larger diameter than the rest of the pressing spring 5 and acts on the connecting rod 6 passing through it, is located at the tips of a pair of mutually opposing projecting pieces 9 formed as a retaining device in the lower case 8. A spring 5 is inserted behind the hook-shaped process 10 and pressed.
is shown to be held in such a way that it cannot be detached from the holding device 9. Therefore, according to this proposal, even if the electromagnetic coil 4 is removed for replacement, it is possible to prevent the electromagnetic coil 4 and the pressing spring 5 from falling off, thereby preventing the fixed iron core 7, the connecting rod 6, etc. from becoming separated.

However, in the means disclosed in the specification of Japanese Patent Publication No. 55-46613, the hook-shaped projections 10 at the tips of the pair of protruding pieces 9 formed on the lower case 8 are located on the same horizontal plane. Although a conical inclined surface is formed inside the upper part of the protrusion 10 to make it easier to slip when inserting the presser spring 5, it is difficult to insert the end turn 5a of the presser spring 5 into the back side of the hook-shaped protrusion 10. The disadvantage is that a very large force is required because the pressing spring 5 has high rigidity. In order to overcome this drawback, the means disclosed in the specification of Japanese Patent Publication No. 55-46613 is to hold the presser spring 5 inside a special presser spring inserter 13 as shown in FIG. Press-fit protrusion 14 at the tip of 13
It has been proposed to bend the end turn 5a as shown by the dotted line in the figure while lowering it between the hook-shaped protrusions 10 and insert it in a snap-type manner. Although it is possible to achieve the purpose by such means, it is extremely inconvenient and uneconomical to use the above-mentioned special insertion tool to insert the end winding of the presser spring into the holding device. I can't escape it.

[Purpose of invention]

This invention eliminates the drawbacks of the conventional device mentioned above,
To provide an electromagnetic switch which prevents parts from falling off or scattering when an electromagnetic coil is removed for replacement, and which can be easily attached and detached without using special tools.

[Key points of the idea]

In order to achieve the above object, the present invention is an electromagnetic switch in which a fixed iron core is attached to a lower case and an electromagnetic coil is sandwiched between the lower case and the upper case. a fixed iron core having a through hole whose lower end is in contact with the elastic body and into which the wire spring is inserted; an inclined surface integrally formed in the lower case on which the wire spring slides; and a fixed iron core connected to the inclined surface to hold the wire spring. A pair of left and right hook portions having hooks and an electromagnetic coil attached to the fixed iron core are provided, and both ends of a wire spring inserted into a through hole of the fixed iron core are engaged with respective hooks of the pair of left and right hook portions. A fixed iron core is supported by a wire spring, and a lower end of an electromagnetic coil attached to the fixed iron core is brought into contact with the elastic body.

[Example of idea]

Examples of this invention will be described below based on the drawings. Fig. 1 is a front sectional view of an electromagnetic switch which is an embodiment of this invention, and Fig. 2 is a front sectional view of the same.
Components that are the same as those of the conventional device shown in FIGS. 7 to 9 are given the same reference numerals, and explanations thereof will be omitted. This embodiment differs from the conventional device in the holding structure of the fixed core and the electromagnetic coil. That is, the fixed iron core 7 is located opposite to the moving direction of the movable iron core 3, and the wire spring 1
2, the lower case 8 is pressed and held by the lower case 8.
The electromagnetic coil 4 is attached between the movable core 3 and the fixed core 7, and has one end 4a extending from the protrusion 11a of the upper case 11, and the other end 4b extending from one end of the buffer rubber plate 13 of the fixed core 7. It is held between the lower case 8 via the protrusion 13a. In order to assemble the fixed core 7 in such a configuration, as shown in FIG.
Next, the fixed iron core 7 with the spring 12 inserted into the through hole 7a
When the wire spring 12 is inserted into the lower case 8, the wire spring 12 comes into contact with the inclined surface 14b of the hook portion 14, as shown in FIG. , descends while curving as shown in FIG. If you press it further, the 6th
As shown in the figure, the restoring force of the wire spring 12 allows it to be engaged with the hook 14a in a snap manner, completing the assembly of the lower case portion. Next, to incorporate the electromagnetic coil 4, insert the electromagnetic coil 4 into the lower case 8, cover it with the upper case 11, and connect one end 4a of the electromagnetic coil 4 to the protrusion 11a of the upper case 11, and the other end. 4b is brought into contact with the tongue-like protrusion 13a of the buffer rubber plate 13 and pressed and clamped using the elasticity of the rubber, and the upper case 11 and the lower case 8 are connected with screws, etc., thereby assembling the electromagnetic switch. Complete. Therefore, when replacing the electromagnetic coil 4, the assembly work described above is reversed, and the replacement is extremely simple.

Note that the electromagnetic coil 4 may be held between the upper case 11 and the lower case 8, but in this case, the gap H (the first ) will occur, and the parts that come into contact, such as one end 4a of the electromagnetic coil 4 and the protrusion 11a of the upper case 11, will be worn out or damaged due to slight movement of the electromagnetic coil 4 caused by the operational impact of the electromagnetic switch. The problem is that it is easy. However, according to the present invention, a tongue-like protrusion 13a is provided on the buffer rubber plate 13 which is sandwiched between the fixed core 7 and the lower case 11, and the elasticity of the rubber is used to press and hold the upper case 11. You can solve the problems mentioned above without increasing your score.

Although the embodiment according to this invention has been described with respect to an electromagnetic switch, this structure can also be applied to an electromagnetic contactor or the like.

[Effect of idea]

In this invention, a rod-shaped wire spring is used as a pressing spring that presses the fixed iron core against the lower case, and a hook part is provided with a hook that engages with the wire spring and an inclined surface that guides the wire spring to the hook. The fixed iron core with a wire spring inserted into the through hole of the fixed iron core can be inserted into the lower case and engaged with the hook in a snap manner by simply pushing the wire spring downward. There is no need for any special tools and it can be easily removed using an ordinary screwdriver. In addition, the electromagnetic coil has one end in contact with the upper case and the other end in contact with the lower case through an elastic body such as a cushioning rubber plate, so that there is a gap between the electromagnetic coil and the upper case and the lower case. It is possible to prevent wear and damage of the end of the electromagnetic coil and the portion that comes into contact with the protrusion of the upper case, which is caused by slight movement due to impact during operation of the electromagnetic switch.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of an electromagnetic switch which is an embodiment of this invention, Fig. 2 is a side sectional view of the same, and Fig. 3 is a sectional view of the electromagnetic switch.
The figure is a perspective view showing the combination of the fixed core, wire spring, buffer rubber plate, and lower case. Figures 4, 5, and 6 are partial plane views showing the assembly order of the lower case and wire spring. Fig. 7 is a front sectional view of an electromagnetic switch with a conventional structure, Fig. 8 is a side sectional view of the same as above, Fig. 9 is a partial side sectional view of the same as above, centering on the pressure spring; FIG. 10 is a front cross-sectional view of the same as above, and FIGS. 11 and 12 are partial cross-sectional views showing the relationship between a conventional pressure spring and its holding device. 4: Electromagnetic coil, 4a: One end of the electromagnetic coil,
4b: The other end of the electromagnetic coil, 7: Fixed iron core, 7
a: Through hole, 8: Lower case, 11: Upper case, 11a: Projection of upper case, 12: Wire spring, 13: Elastic body such as rubber (buffer rubber plate), 1
4: hook portion, 14a: hook, 14b: inclined surface.

Claims (1)

[Scope of utility model registration request] In an electromagnetic switch in which a fixed iron core is attached to a lower case and an electromagnetic coil is sandwiched between the lower case and the upper case, an elastic body placed on the lower case,
A fixed iron core having a through hole whose lower end is in contact with the elastic body and into which the wire spring is inserted; an inclined surface formed integrally with the lower case on which the wire spring slides; and a fixed iron core connected to the inclined surface to hold the wire spring. A pair of left and right hook portions having hooks that are connected to each other and an electromagnetic coil attached to the fixed iron core are provided, and both ends of a wire spring inserted into a through hole of the fixed iron core are engaged with respective hooks of the pair of left and right hook portions. An electromagnetic switch characterized in that a fixed iron core is supported by a wire spring, and a lower end of an electromagnetic coil attached to the fixed iron core is brought into contact with the elastic body.