JPS643156Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic switch device mainly applied to a starter motor for an engine.

Conventionally, this type of device has housed a coil assembly consisting of a coil bobbin that holds a coil, a yoke plate in front of it, and an end plate behind it in a frame housing-like yoke extending rearward from a front bracket. A cover is applied to the end to constitute the electromagnetic switch body, and a movable iron core having a contact plate at the tail end facing the terminal contact extending forward from the cover is retreated against the spring as the coil is excited. A type of movable cover is known, but in this case, the cover is generally made airtight through rubber packing to prevent foreign matter from entering, and in such a case, the space in front of the cover is Since the inside of the space is kept airtight, when the iron core moves backward as described above, the inside of the space becomes a positive pressure, which tends to hinder the movement to some extent. Next, when it is rapidly cooled by muddy water, etc., the air inside expands and then contracts, and as a result, moisture from the outside is sucked in from the mating surfaces of the packing, etc., and this condenses on the internal contacts, damaging them. It comes with inconveniences such as winning.

The purpose of the present invention is to obtain a device free from such inconveniences, and includes a coil bobbin 4 that holds a coil 3 in a frame housing-like yoke 2 that is fixed to a front bracket 1 and extends rearward, and The electromagnetic switch main body is constructed by accommodating the yoke plate 5 and the rear end plate 6 overlapping each other, and applying a cover 7 to the tail end thereof, and a terminal contact 8 extending forward from the cover 7 inside the electromagnetic switch body. . Space behind 1
2, a through hole 13a is formed on the side surface of the rear end plate 6 and is located inward from the outermost diameter of the coil bobbin 4, and grooves 13b and 13c are formed on the front and rear surfaces of the coil bobbin 4, respectively. and a through hole 13d formed on the side surface of the front yoke plate 5 so as to be located inward from the outermost diameter of the coil bobbin 4. A space 14 in front of the movable core 10 is formed inside the switch body through a ventilation passage 13 that is open on the side surface and whose other end is recessed to a position at least communicating with the through holes 13a and 13c.
It is characterized by communicating with the inside.

The drawing shows a case where the application is applied to an engine starter motor, and the space 14 includes a movable iron core 10.
It accommodates a shift lever 22 that is to be engaged with to shift the front pinion 21, and communicates with the front space 16 and the interior space 18a of the motor 18 through the front and side ventilation holes 15a, 15b. death,
Furthermore, both spaces 16 and 18a communicate with the atmosphere through drain holes 15c and 15d located on the lower side in the drawing when installed.

Furthermore, the space 16 described above is comprised of a gear chamber in front of the bracket 1, and a gear 17 therein is connected to a gear 2 on an output shaft 19 extending from a motor 18 on the side thereof.
0 so that it can be driven by the motor 18. The details of the ventilation passage 13 are as clearly shown in FIG. The grooves 13b, 13b, the grooves 13c, 13c formed on the front surface thereof, and the yoke plate 5.
The ventilation passages 13 are connected to a pair of left and right through holes 13e, 13e on the back surface of the yoke 2 through the through holes 13d, 13d formed in the yoke 2, so that the two ventilation passages 13 on the left and right are arranged in parallel. .

To explain its operation, when the coil 3 is energized, the movable core 10 moves backward against the spring 11 along with the contact plate 9, thereby closing the contacts 8, 8 at both terminals. is not particularly different from the conventional one, but
During such operation, the air in the space 12 behind the iron core 10 flows through the air passage 13 into the space 14 in front of it.
In this way, positive pressure is not generated in the space 12 due to air compression, and the movement of the iron core 10 can be made light and heat generation of the coil 3 can be suppressed. Furthermore, when the air in the space 12 contracts due to temperature changes, the air in front of the space 12 is guided through the air passage 13, so that water from outside is not sucked in.

In this way, according to the present invention, the inside of the space 12 behind the movable iron core 10 is communicated with the space 14 in front of the movable iron core 10 via the air passage 13 formed in the end plate 6, the coil bobbin 4, and the yoke plate 5. Since the movement of the movable iron core 10 is not hindered, damage to the contacts in the space 12 due to dew condensation can be prevented.
3 is a coil bobbin 4 on the side of the end plate 6.
The through hole 13 is formed to be located inward from the outermost diameter of the
a, grooves 13b and 13c recessed in the front and rear surfaces of the coil bobbin 4, and the side surface of the yoke plate 5,
It consists of a through hole 13a formed inside the outermost diameter of the coil bobbin 4, and a concave groove 13 therein.
b, 13c have one end opened at the outermost surface of the coil bobbin 4, and the other end at least through holes 13a, 1
3c, the outer diameter of the yoke 2 is determined based on the coil 3 and the movable core 10 even though it forms an air passage, and it is almost necessary to consider the air passage structure. Since there are no holes, miniaturization is possible, and each through hole 13a, 13b of the end plate 6 and yoke plate 5 can be formed to the minimum necessary diameter regardless of the outer diameter of the coil bobbin 4, so that a magnetic path can be secured. Both plates 5,
This has the advantage that the ventilation passage 13 can be formed without increasing the diameter of the air passage 6.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view of an example of the device of the present invention, and FIG. 2 is an exploded perspective view of the main parts thereof. 1...Front bracket, 2...Yoke, 3
... Coil, 4 ... Coil bobbin, 5 ... Yoke plate, 6 ... End plate, 7 ... Cover,
8, 8...Terminal contact, 9...Contact plate, 10
...Movable contact, 11...Spring, 12...Space, 1
3...Air passage, 14...Space.

Claims (1)

[Scope of utility model registration request] A coil bobbin 4 that holds a coil 3 within a frame housing-like yoke 2 that is fixed to a front bracket 1 and extends rearward, and a yoke plate 5 in front of the coil bobbin 4.
The electromagnetic switch main body is constructed by overlapping and housing the rear end plates 6 and a cover 7 on the tail end thereof, and inside the electromagnetic switch body there are contacts facing the terminal contacts 8, 8 extending forward from the cover 7. In a device in which a movable core 10 having a plate 9 at its tail end is movable against a spring 11 as the coil 3 is energized, a space 12 behind the movable core 10 formed within the switch body is provided. A through hole 13a is formed on the side surface of the rear end plate 6 and is located inward from the outermost diameter of the coil bobbin 4, and a groove 1 is formed on the front and rear surfaces of the coil bobbin 4, respectively.
3b, 13c, and a through hole 13d formed on the side surface of the front yoke plate 5 so as to be located inward from the outermost diameter of the coil bobbin 4.
b, 13c have one end opened at the outermost surface of the coil bobbin 4, and the other end at least through the through hole 13.
An electromagnetic switch device characterized by communicating with a space 14 in front of the movable core 10 formed within the switch body through a ventilation path 13 recessed to a position communicating with the movable iron core 10.