JP3796792B2 - Magnetic switch for starter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a magnet switch (electromagnetic switch) attached to an electric starter for starting an engine of an automobile or the like.
[0002]
[Prior art]
A magnet switch attached to a starter for an engine of an automobile receives air containing moisture and dust, splash of muddy water, and the like while the automobile is running. The magnet switch suddenly rises in temperature when the engine starts, and the temperature rises rapidly due to heat conduction from the adjacent starter. On the contrary, the magnet switch is not used when the vehicle is traveling and the temperature gradually decreases, so that the internal pressure is lower than the surroundings during traveling. At this time, if muddy water or the like adheres to the outer wall of the starter, muddy water or the like may be sucked from a slight gap in the casing due to a pressure difference between the inside and outside of the magnet switch. Since moisture and various contaminants sucked into the magnet switch can cause failure, it is desirable to prevent such suction. Also, once the moisture has entered, it evaporates to increase the humidity of the internal space, and if the magnet switch is cooled as it is, it will condense on a metal part or the like that is easily cooled, and water droplets will be generated.
[0003]
For the above reasons, conventionally, a ventilation hole has been provided in a magnet switch. For example, as shown in FIG. 4, there is a magnet switch in which a ventilation pipe 9 is attached to the lower part of the case body 11. The vent pipe 9 is formed with a vent hole 90 that opens into the space in the case 1 at the upper end and communicates with the outside from the vent 91 at the lower end. Therefore, when a pressure difference with the outside air is generated in the internal space formed by the case 1, the ventilation pipe 9 is naturally ventilated.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional magnet switch, when a strong water flow is applied due to the splashing of muddy water by the wheels while the vehicle is running, contaminants such as moisture invade through the ventilation hole 90 of the ventilation pipe 9. There was a possibility. It is not preferable that contaminants enter the internal space of the magnet switch, but even if it is divided, entry into the contact chamber 40 is directly connected to malfunctions such as contact failure of the magnet switch, so it has to be prevented by all means. .
[0005]
Accordingly, an object of the present invention is to provide a starter magnet switch that communicates with the outside only when the magnet switch is in operation, and closes the vent hole to prevent entry of contaminants when the magnet switch is not in operation. This is based on the idea that the contaminants enter the magnet switch because the air holes are always open.
[0006]
[Means for solving the problems and their functions and effects]
In order to solve the above problems, the inventors have invented the following means.
(First means)
The first means of the present invention is the starter magnet switch according to claim 1. In this means, the shielding member opens and closes the vent hole when driven by the plunger. That is, only when the electromagnetic coil is energized and the plunger moves and the switch contact is closed, the shielding member is removed from the vent hole, and the internal space communicates with the outside through the vent hole. Normally, when the magnet switch is activated, the vehicle is stopped, so that the wheels can be safely communicated to the outside without splashing water. Conversely, when the armature coil is not energized, the plunger retracts and returns, and the switch contact is open, the shielding member closes the vent hole to prevent entry of contaminants from the outside.
[0007]
Therefore, according to this means, there is an effect that intrusion of contaminants such as moisture from the vent hole can be prevented even under adverse conditions such as flooding after the starter is driven. As a result, the reliability of the starter magnet switch is improved and it can be used in a worse environment.
Note that this means has a very simple structure, and since the shielding member is driven by the plunger, it can be implemented with little cost increase.
[0008]
(Second means)
The second means of the present invention is the starter magnet switch according to claim 2.
In this means, since the vent hole (discharge hole) opens at the bottom of the internal space (the lowest part or recess in the ground direction with the starter mounted on the vehicle), contaminants such as moisture condensed in the internal space However, it naturally gathers in the discharge hole by gravity. The vibration of the vehicle has the effect of promoting the collection of pollutants in the discharge holes, and is even more convenient.
[0009]
Therefore, according to this means, in addition to the effect of the first means described above, there is an effect that the pollutant can be efficiently discharged using gravity and vibration, and the pollutant is less likely to stay in the internal space. As a result, problems due to contamination entering the internal space of the magnet switch are prevented, and the reliability of the magnet switch is further improved.
(Third means)
The third means of the present invention is the starter magnet switch according to claim 3.
[0010]
In this means, the shielding member comprises a shielding part and a connecting part. Since the shielding part opens and closes the vent hole, and the connecting part connects the shielding part and the plunger, the plunger drives the shielding part via the connecting part.
Therefore, according to the present means, in addition to the effect of the first means described above, there is an effect that the degree of freedom increases in the place where the air hole is provided in the case.
[0011]
(Fourth means)
The fourth means of the present invention is the starter magnet switch according to claim 4.
In this means, since the connecting portion is formed of a wire, the plunger drives the shielding portion via the connecting portion made of a wire.
Therefore, according to this means, in addition to the effect of the above-mentioned third means, there is an effect that the degree of freedom is further increased with respect to the place where the ventilation hole is provided in the case.
[0012]
(5th means)
The fifth means of the present invention is the starter magnet switch according to claim 5 at the time of filing .
In this means, the vent hole is formed as a gap with the shaft hole of the case, and the shielding member is coaxially fixed to the plunger. Therefore, with the movement of the plunger, the shielding member opens and closes the vent hole as if the lid was opened and closed.
[0013]
Therefore, according to this means, in addition to the effect of the first means described above, the configuration of the shielding member is extremely simple, and the shaft hole is used as a vent hole, so there is no increase in cost (or very little). There is an effect. In addition, since the configuration is simple, there is an effect that the occurrence of failures and malfunctions is reduced. In addition, since the vent is opened at the position farthest from the contact chamber where water and dust are abolished, even if contaminants enter the vent, it prevents malfunction such as poor contact. be able to.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the magnet switch for starter of the present invention will be described clearly and sufficiently in the following examples and the like so that a person skilled in the art can understand that the embodiment can be implemented.
[Example 1]
(Configuration of Example 1)
As shown in FIG. 1, the starter magnet switch according to the first embodiment of the present invention includes a case 1 that forms an internal space, an electromagnetic coil 2 that is fixed in the case 1, and an inside of the electromagnetic coil 2. And a movable plunger 3. The magnet switch according to the present embodiment is characterized by a vent hole (discharge hole) 5 formed in the bottom of the case 1 that becomes the ground direction when the vehicle is mounted, and a shielding member 6 that is driven by the plunger 3 to open and close the vent hole 5. It is in having.
[0015]
The case 1 includes a case body 11 that forms a space 100 therein, a front lid 12 that divides the internal space 100 in the axial direction and supports the electromagnetic coil 2, and one end (rear end) of the case 1. And a back cover 13 that closes the door. The case body is a cylindrical member made of an aluminum alloy and forms the side surface of the case 1. The front lid 12 is a cutting member made of mild steel formed in a substantially disc shape, and the shaft hole 10 communicates with the front and rear in the center. The back cover 13 is a sheet metal member made of mild steel press-molded in a substantially rotationally symmetric shape, and a concave portion with which the rear end portion of the plunger 3 abuts is formed at the center portion. The back cover 13 is fixed to the rear end of the case body 11 with a plurality of bolts 14.
[0016]
The electromagnetic coil 2 is fixed to the case 1 by a yoke (not shown) that forms a magnetic path together with the front lid 12, and is accommodated in the internal space 100. In the electromagnetic coil 2, the axis of the electromagnetic coil 2 coincides with the axis of the case 1, and the inner peripheral surface of the electromagnetic coil 2 is formed in a cylindrical surface so that it is covered with a material that has little friction and is difficult to wear. It has been broken.
The plunger 3 is a rotationally symmetric member, is supported coaxially with the case 1 and the electromagnetic coil 2, and can move in a predetermined range in the front-rear direction (left-right direction in the figure). The plunger 3 includes a plunger shaft 31, a plunger body 32, a contact conductor 33, and a rear end member 34 in order from the front (left side in the figure). The plunger shaft 31 is joined to the front end portion of the plunger main body 32 with a round bar-shaped strength member, and the tip of the plunger shaft 31 protrudes from the front end surface of the case 1 through the shaft hole 30 of the case front lid 12. . The plunger main body 32 is a cylindrical member made of a soft magnetic material, and slides back and forth along the inner peripheral surface of the electromagnetic coil 2 described above. The contact conductor 33 is a disk-shaped member made of a copper alloy joined to the rear end of the plunger main body 32. The rear end member 34 is a member that is joined to the plunger main body 32 and the contact conductor 33 and forms the rear end portion of the plunger 3. The rear outer peripheral surface of the rear end member 34 is formed in a conical surface shape, and abuts against the inner peripheral surface of the concave portion of the rear lid 13 to restrict the retracted position of the plunger 3.
[0017]
Here, a contact chamber 40 is formed as a part of the internal space 100 behind the rear end surface of the electromagnetic coil 2, and switch electrodes 41 and 42 are provided on the outer periphery of the first half in the contact chamber 40. 2 is fixed to the rear end. One of the switch electrodes 41 and 42 is electrically connected to a battery (not shown), and the other is electrically connected to a starter (not shown).
[0018]
While the electromagnetic coil 2 is not energized, the plunger 3 is in a position retracted in the case 1 as shown.
When the electromagnetic coil 2 is energized by a predetermined amount, the electromagnetic coil 2 forms a magnetic field and attracts the plunger main body 32 with a magnetic force, so that the plunger 3 moves forward (leftward in the figure). The forward position of the plunger 3 is regulated by the front end surface of the plunger main body 32 coming into contact with the rear end surface of the front lid 12. When the plunger 3 moves forward, the contact conductor 33 comes into contact with the switch electrodes 41 and 42 and the switch electrodes 41 and 42 are electrically connected. As a result, a starter (not shown) is driven, and an engine (not shown) is started via a pinion gear (not shown) pushed out by the plunger 3.
[0019]
On the contrary, when the energization to the electromagnetic coil 2 is interrupted, the plunger 3 is retracted by the repulsive force of a spring (not shown) inserted in the magnet switch and returns to the original position. At the same time, since the contact conductor 33 leaves the switch electrodes 41 and 42, conduction between the switch electrodes 41 and 42 is lost.
Now, one end of the vent hole 5 is opened in the outer wall of the case body 11, the other end of the vent hole 5 is opened in the bottom of the internal space 100, and the vent hole 5 communicates the internal space 100 with the outside. ing.
[0020]
On the other hand, the shielding member 6 is integrally formed of a synthetic resin, which is a nonmagnetic material, from a shielding portion 61 that covers the one end of the vent hole 5 from the internal space 100 and a connecting portion 62 that is fixed to the plunger shaft 31. Is formed. Therefore, since the shielding portion 61 is joined to the plunger shaft 31 by the connecting portion 62, the shielding portion 61 moves back and forth according to the back and forth movement of the plunger 3, opens the vent hole 5 when the magnet switch is operated, and passes when the magnet switch is not operated. The pore 5 is closed.
[0021]
(Operational effect of Example 1)
In the starter magnet switch of this embodiment, the shielding member 6 opens and closes the vent hole 5 when driven by the plunger 3. That is, only when the electromagnetic coil 2 is energized to move the plunger 3 and the switch contacts 41 and 42 are closed, the shielding member 6 is detached from the vent hole 5, and the internal space 100 is exposed to the outside through the vent hole 5. Communication and ventilation are performed to eliminate the pressure difference between the inside and outside air. Also, in the unlikely event that contaminants such as moisture have entered the internal space 100, these contaminants are discharged when the vent hole 5 communicates. On the contrary, when the electromagnetic coil 2 is not energized and the plunger 3 is retracted and the switch contacts 41 and 42 are opened, the shielding member 6 closes the vent hole 5 to prevent entry of contaminants from the outside. To prevent.
[0022]
Therefore, according to the present embodiment, even if the magnet switch is exposed to contaminants such as water, dust, sand dust, and oil after the starter is driven, contaminants can enter from the vent hole 5. It has the effect of being prevented.
Even when moisture enters and the humidity in the internal space 100 increases, the air hole 5 communicating with the internal space 100 is opened when the magnet switch is operated, so that the air in the internal space 100 passes through the air hole 5. Ventilated. As a result, the humidity of the internal space 100 decreases to a humidity close to the outside air, so that it is difficult for water droplets due to condensation in the internal space 100 to be formed. Furthermore, since the vent hole 5 is open at the bottom of the internal space 100 (lower in the direction of gravity when mounted on the vehicle), even if there is moisture that has entered the internal space 100, the vent hole 5 naturally forms due to gravity. It gathers in the vicinity.
[0023]
Therefore, according to the present embodiment, the pollutant that is incurred during vehicle operation does not enter the internal space 100 of the magnet switch, and on the contrary, the pollutant can be discharged and the humid air can be ventilated very efficiently when the magnet switch is operated. There is an effect that contaminants hardly stay in the internal space 100.
As a result, in the starter magnet switch of this embodiment, the probability of occurrence of a malfunction such as poor contact is drastically reduced, the reliability is further improved, and it can be used in a worse environment.
[0024]
In the present embodiment, the vent hole 5 is formed in the case main body 11 and the shielding member 6 is simply fixed to the plunger shaft 31. Moreover, the shielding member 6 includes the shielding portion 61 and the connecting portion 62 integrated with synthetic resin. Since it is manufactured by molding, its configuration is very simple. Further, since the shielding member 6 is driven by the plunger 3, there is an advantage that it is not necessary to separately provide a driving means and can be implemented with almost no cost increase as compared with the prior art.
[0025]
(Modification of Example 1)
In the above-described embodiment, a filter may be provided in the vent hole 5. As the filter, a synthetic fiber, an activated carbon filter, a synthetic paper filter, or the like can be used. If the filter is provided, it is possible to prevent entry of contaminants jumping into the vent hole 5 from the outside at the moment when the vent hole 5 is opened when the magnet switch is operated. Note that a protrusion may be provided at the rear end portion of the shielding portion 61, and a filter may be provided on the protrusion so that the filter covers the vent hole 5 when the magnet switch is activated.
[0026]
Moreover, you may form a part or all of the shielding part 61 with a filter. If the portion of the shielding portion 61 that closes the vent hole 5 is formed of a filter, a predetermined air permeability is ensured through the vent hole 5 even when the magnet switch is not operated (when the starter is not turned). The As a result, the introduction of air through the filter has an effect that condensation in the internal space 100 is suppressed to some extent, rather than high-humidity air that has not been filtered by the filter enters the internal space 100.
[0027]
The material 6 of the shielding member is not limited to the synthetic resin, and may be FRP, light alloy, other alloy, non-metallic material, or the like.
Further, when it is difficult to form the vent hole 5 at the bottom of the internal space 100 due to the arrangement with surrounding equipment (starter, engine, etc.), the vent hole may be provided at another position. In this case, the degree of freedom of design is further expanded.
[0028]
[Example 2]
(Configuration of Example 2)
As shown in FIG. 2, the starter magnet switch according to the second embodiment of the present invention is characterized in that the connecting portion 66 of the shielding member 6 ′ is formed of a wire.
[0029]
That is, in this embodiment, the shielding member 6 ′ includes a shielding part 63 that covers the vent hole (discharge hole) 5, a return spring 64, a guide member 65, and a wire connecting part 66. The guide member 65 is an alloy member that is bonded and fixed to the inner side surface of the case main body 11 ′, and accommodates the return spring 64 along the axial length direction. The guide member 65 accommodates the rear end portion (right end portion in the drawing) of the shielding portion 63 in contact with the front end (left end portion in the drawing) of the spring 64 and guides the shielding portion 63 in the front-rear direction (left and right in the drawing). It is slidably supported. One end of the connecting portion 66 made of a wire is connected to the rear end member of the plunger 3, and the other end is connected to the shielding member 63. The intermediate portion is in contact with the guide pin 651 of the guide member 65.
[0030]
(Effect of Example 2)
In this embodiment, since the connecting portion 66 is formed of a wire, the plunger 3 drives the shielding portion 63 via the wire 66 that is the connecting portion.
That is, when the electromagnetic coil 2 is energized and the plunger 3 moves forward (to the left in the figure), one end of the wire 66 that is a connecting portion is pulled by the rear end member 34, and the shielding portion 63 slides on the outer periphery of the pin 651. The other end connected to is moved backward (rightward in the figure). Then, the shielding part 63 is pulled by the wire 66 which is a connecting part and moves rearward, opens the vent hole 5 and compresses the spring 64. The vent hole 5 is formed in the case main body 11 ′ and opens at the bottom of the internal space 100, so that contaminants that have entered the internal space 100 are quickly discharged from the vent hole 5.
[0031]
On the contrary, when the energization to the electromagnetic coil 2 is interrupted and the plunger 3 is retracted, the wire 66 forming the connecting portion is loosened, and the shielding portion 64 is advanced by the repulsive force of the compressed spring 64 and the vent hole is formed. 5 is closed. Therefore, even when the vehicle equipped with the magnet switch is covered with a contaminant such as muddy water or dust, the contaminant is prevented from entering the internal space 100 of the magnet switch of this embodiment.
[0032]
The advantage of the magnet switch of the present embodiment is that the shielding portion 63 is driven via the wire 66 as the connecting portion, and therefore the degree of freedom is further increased in the place where the vent hole 5 is provided in the case 1 ′.
(Modification of Example 2)
Also in the present embodiment, modified embodiments corresponding to the modified embodiments of the first embodiment are possible.
[0033]
[Example 3] (Corresponding to claim 5 at the time of filing, the initial procedure amendment will be outside the scope of the claim)
(Configuration of Example 3)
In the starter magnet switch according to the third embodiment of the present invention, as shown in FIG. 3, the vent hole is formed as a gap between the plunger shaft 31 and the shaft hole 10 of the front lid 12 of the case 1 ″ passing through the shaft 31. The shielding member 6 ″ includes an O-ring 67 and a fixing bracket 68 that are coaxially fixed to the plunger shaft 31. The fixing metal 68 is a disk-shaped member having a flat rear end surface, is welded to the plunger shaft 31, and is in contact with the front end surface of the O-ring 67. When the plunger 3 is retracted, the fixing metal 68 presses the O-ring 67 around the shaft hole 10 of the front lid 12 from the front to close the shaft hole 10 as a ventilation hole, and at the peripheral portion, the front surface of the front lid 12 is closed. The vicinity of the central portion of the O-ring 67 is also sealed to prevent contamination near the O-ring 67.
[0034]
(Effect of Example 3)
In the starter magnet switch of the present embodiment, the vent hole is formed as a gap between the shaft hole 10 of the front lid 12 of the case 1 ″ and the plunger shaft 31, and the shielding member 6 ″ is fixed coaxially to the plunger shaft 31. ing. Therefore, as the plunger 3 moves, the shielding member 6 ″ opens and closes the vent hole (shaft hole 10) so that the lid opens and closes.
[0035]
Therefore, according to the present embodiment, the configuration of the shielding member 6 ″ is extremely simple, and the shaft hole 10 is used as a ventilation hole, so that the cost increase associated with the installation of the ventilation hole and the shielding member 6 ″ is minimized. There is an effect that it can be suppressed. In addition, since the configuration is simple, there is an effect that the occurrence of failures and malfunctions is reduced.
Further, since the vent hole (shaft hole 10) is opened at the position farthest from the contact chamber 40 that is most unfavorable for contamination, even if contaminants enter from the vent hole, malfunction such as poor contact is caused. Can be prevented.
[0036]
In addition, the front end surface of the starter magnet switch usually faces the housing (such as the clutch chamber) of the starter motor, and does not directly face the external space. Therefore, there is an effect that the intrusion of contaminants such as dust and muddy water from the vent hole (shaft hole 10) is finally reduced.
In addition, when the shaft hole 10 also serves as a vent hole as in the present embodiment, there is an effect that the air resistance accompanying the movement of the plunger is reduced and the operation of the magnet switch can be performed more quickly.
[0037]
(Modification of Example 3)
Also in the present embodiment, modified embodiments corresponding to the modified embodiments of the first embodiment are possible.
[Brief description of the drawings]
FIG. 1 is a sectional side view of a starter magnet switch of Example 1. FIG. 2 is a sectional side view of a starter magnet switch of Example 2. FIG. 3 is a sectional side view of a starter magnet switch of Example 3. 4] Side sectional view of the prior art starter magnet switch [Explanation of symbols]
1: Case 11, 11 ': Case body 12: Front lid 13: Rear lid 14: Bolt 10: Shaft hole 100: Internal space 2: Electromagnetic coil 3: Plunger 31: Plunger shaft 32: Plunger body 33: Contact conductor 34: Rear end member 40: contact chamber 41, 42: switch electrode 5: vent hole (discharge hole)
6, 6 ', 6 ": Shielding member 61: Shielding part 62: Connecting part 63: Shielding part 64: Return spring 64 65: Guide member 651: Guide pin 66: Wire 67 as connecting part: O-ring 68: Fixing bracket 9: Ventilation pipe 90: Vent 91: Vent

Claims (7)

In a starter magnet switch having a case forming an internal space, an electromagnetic coil fixed in the case, and a plunger that is attracted and driven by the magnetic force of the coil,
A vent hole that opens in the outer wall of the case and communicates the internal space with the outside ;
A shielding member that is driven by the plunger to open and close the vent hole;
The starter magnet switch is characterized in that the vent hole is opened by the shielding member when the plunger is sucked and closed when the plunger is returned.   2. The starter magnet switch according to claim 1, wherein the vent hole is a discharge hole opened in a bottom portion of the internal space in a ground direction when the vehicle is mounted. The shielding member is
A shield that opens and closes the vent;
A connecting part for connecting the shielding part and the plunger;
The starter magnet switch according to claim 1, comprising:   The starter magnet switch according to claim 3, wherein the connecting portion is formed of a wire. The shielding part has a protruding part, and the protruding part is provided with a filter that covers the vent hole when the magnet switch is operated.
The starter magnet switch according to claim 3. Of the shielding part, at least a part for closing the vent is formed by a filter,
The starter magnet switch according to claim 3. The vent is provided with a filter.
The starter magnet switch according to claim 1.

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