JP2004335283A - Switch for parking brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switch for parking brake for which the number of parts required is decreased, which can be mounted in both of the right and left directions and which has been reduced in cost. <P>SOLUTION: In the switch for parking brake, its outer shell is formed of a switch case 30. The switch case 30 is provided with a switch stem 31 which performs switching operation by force exerted from outside, and a return spring 36 is mounted at a lower face side of the switch stem 31 so that the switch stem 31 may slide upward and downward. A movable contact 32 is fitted to the switch stem 31, and the movable contact 32 moves according to vertical sliding motion of the switch stem 31 to come into contact with or be disconnected from fixed contacts 37, 38. The switch is characterised in that, one of the fixed contacts can function also as an attaching tool for the switch. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a parking brake switch, and more particularly to an improvement of a parking brake switch with a reduced number of components.
[0002]
[Prior art]
In a vehicle such as an automobile, when a mounted brake lever or parking brake pedal is operated, a lamp of a parking brake operation notification circuit is turned on / off according to the operation. A parking brake switch is used to perform such lamp switching.
[0003]
A conventional parking brake switch has a structure as shown in FIGS. 4, 5 and 6, for example. Here, FIG. 4 is an exploded perspective view of a conventional parking brake switch, FIG. 5 is a schematic sectional view for explaining a structure of a movable contact in the conventional parking brake switch, and FIG. 6 is a conventional parking brake switch. FIG. 2 is a schematic cross-sectional view for explaining a structure of a contact portion of a switch.
[0004]
The conventional parking brake switch has a switch case 10 having an outer shell. The switch case 10 includes a movable contact 14 including a switch shaft 11, a movable contact 12, and a movable contact fixing spring 13, and a fixed contact including a body ground fixed contact 17 and a connector terminal fixed contact 18. 19 are installed.
[0005]
As shown in FIG. 5, the movable contact 14 is fitted with a movable contact 12 in an opening 11 a of the switch shaft 11, and the movable contact 12 is attached to a movable contact fixing spring installed inside the switch shaft 11. 13 for fixing. The movable contact 14 thus formed is supported on its lower surface by a pressing member 15 and a return spring 16, and can be slid in the vertical direction by the elastic force of the return spring 16.
[0006]
The fixed contact 19 is provided at a position where the movable contact 14 is sandwiched between the fixed contact 17 for body ground and the fixed contact 18 for the connector terminal from both sides. The body ground fixed contact 17 has a hole 17a for inserting a bolt. The hole 17a is used for fixing a parking brake switch, and is fixed to a vehicle body or the like by using a bolt (not shown) and a nut 20. The body ground fixed contact 17 also functions as a ground when it comes into contact with a vehicle body or the like. On the other hand, the fixed contact 18 for the connector terminal is formed with a terminal 18a for contacting with a connector or the like and electrically connecting to a device outside the parking brake switch, protruding from the main body of the fixed contact 18 for the connector terminal.
[0007]
Finally, the movable contact 14, the holding member 15, the return spring 16, and the fixed contact 19 are inserted into the switch case 10, and the switch cover 21 covers the lower surface of the switch case 10 to complete the assembly of the parking brake switch. . The switch cover 21 also serves as a support for supporting the lower portion of the return spring 16.
[0008]
The switching operation of the parking brake switch thus configured will be described with reference to FIG. When the switch shaft 11 receives no external force, the movable contact 14 is located at the top of the openings 17 b and 18 b of the fixed contact 19 due to the urging force of the return spring 16. At this time, the movable contact 12 of the movable contact 14 and the fixed contact 19 are in contact with each other and are electrically connected, so that the parking brake switch is turned on (see FIG. 6A). On the other hand, when the switch shaft 11 receives an external force and slides downward against the urging force of the return spring 16, the lower surfaces of the openings 17 b and 18 b of the fixed contact 19 are located outside the movable contact 14. Since the movable contact 12 and the fixed contact 19 are separated from each other, the electrical connection is released. Therefore, the parking brake switch is turned “OFF” (see FIG. 6B).
[0009]
As a form other than the above-described parking brake switch, for example, there is a structure disclosed in Patent Literature 1 below, but the number of parts and the basic structure are almost the same.
[0010]
[Patent Document 1]
JP-A-11-67001
[Problems to be solved by the invention]
In recent years, the manufacturing industry has been required to reduce the number of parts due to demands for cost reduction. Parking brake switches are no exception, and there has been a demand for a product that reduces the number of components and realizes cost reduction while maintaining quality.
[0012]
Further, in the case of the parking brake switch described in the related art, bolts and nuts are used for mounting, but since the mounting position is limited due to its structure, for example, it is called right mounting and left mounting. It was necessary to prepare two types of parking brake switches. This also causes an increase in cost, and there has been a demand for a parking brake switch that can be mounted in both left and right directions with one type of model.
[0013]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and a parking brake switch that can be mounted in both the left and right directions while reducing the number of components and that also achieves cost reduction. To provide.
[0014]
[Means for Solving the Problems]
In order to solve the above-described problems, a parking brake switch according to the present invention includes a switch shaft, a movable contact that is installed on the switch shaft by receiving a biasing force of a return spring, and a contact and separation between the movable contact and the movable contact. A fixed contact is fixedly installed at a possible position. The fixed contact and the movable contact perform a switching operation when the switch shaft is pressed and released from the outside according to the operation of the parking brake. In the parking brake switch according to the present invention, the fixed contact is composed of two members, a fixed contact for a connector terminal and a fixed contact for a body ground, which are installed at substantially the same distance from the movable contact. The fixed contact for ground has a function as a mounting device for a switch for parking brake by being formed of a nut made of a conductive metal, and further, the movable contact receives a biasing force from a return spring to form a switch shaft. By being attached to the fixed contact, it is possible to stably contact the fixed contact.
[0015]
Further, another parking brake switch according to the present invention is fixedly installed at a position where the switch shaft, a movable contact that is installed by receiving a biasing force of a return spring on the switch shaft, and a movable contact with the movable contact. When the switch shaft is pressed and released from the outside according to the operation of the parking brake, the fixed contact and the movable contact perform a switching operation. In such another parking brake switch according to the present invention, the fixed contact is composed of two members, a fixed contact for a connector terminal and a fixed contact for body ground, which are installed at substantially the same distance from the movable contact, The body ground fixed contact has a function as a mounting device for a parking brake switch by being formed of a conductive metal nut, and the movable contact is formed of a spring having a diameter different from that of a return spring. By doing so, it is possible to stably contact the fixed contact.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
Hereinafter, a parking brake switch according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is an exploded perspective view of the parking brake switch according to the present embodiment, and FIG. 2 is a schematic cross-sectional view illustrating the structure of the parking brake switch according to the present embodiment.
[0017]
The switch for parking brake according to the embodiment of the present invention has an outer shell formed by a switch case 30. In the switch case 30, a switch shaft 31 that performs a switching operation by receiving an external force, and a return spring 36 that is installed on the lower surface side of the switch shaft 31 so that the switch shaft 31 can slide vertically. Have been. A movable contact 32 is provided on the switch shaft 31 under the biasing force of the return spring 36. The movable contact 32 moves in accordance with the vertical sliding of the switch shaft 31.
[0018]
The switch shaft 31 slides in the insertion direction of the switch case 30 against the biasing force of the return spring 36 when pressed from the outside, and switches by the biasing force of the return spring 36 when released from the outside. It will protrude from case 30.
[0019]
Here, a feature of the parking brake switch according to the present embodiment is that one of the fixed contacts also serves as a mounting device for the parking brake switch. One of the fixed contacts shown in FIGS. 1 and 2 is a metal plate made of a conductive metal, and is used as a fixed contact 38 for a connector terminal. The other fixed contact is a conductive nut and is used as the body ground fixed contact 37. Therefore, the parking brake switch according to the present embodiment replaces the two members, the body ground fixed contact 17 and the nut 20 as the mounting device, which are required in the parking brake switch shown in the prior art with the fixed contact. Since it is composed of a single member (nut) of the body grounding fixed contact 37, which also serves as a mounting device, the number of parts can be reduced.
[0020]
Further, it is preferable to use a nut as the body ground fixed contact 37 in that the parking brake switch can be mounted in both directions. A nut serving as the body ground fixed contact 37 is fixedly attached to the inner wall of the switch case 30, and mounting holes 30a are provided on both sides of the switch case 30, so that bolts can be installed from both sides. Accordingly, the parking brake switch can be mounted from two directions. By adopting such a structure, in the parking brake switch shown in the prior art, two types, that is, right mounting and left mounting, had to be prepared. The parking brake switch according to the embodiment can be dealt with by one type of model. Therefore, according to the parking brake switch according to the present embodiment, it is possible to reduce the manufacturing cost.
[0021]
Finally, the switch shaft 31, the movable contact 32, the return spring 36, the fixed contact 37 for the body ground, and the fixed contact 38 for the connector terminal are installed in the switch case 30, and the switch cover 41 covers the lower surface of the switch case 30. This completes the assembly of the parking brake switch. The switch cover 41 also serves as a support for supporting the lower portion of the return spring 36.
[0022]
Next, an operation mechanism of the parking brake switch according to the present embodiment will be described with reference to FIG. 2A shows the “ON state” and FIG. 2B shows the “OFF state”.
[0023]
In FIG. 2A, since no external force acts on the switch shaft 31, the switch shaft 31 is positioned upward by the urging force of the return spring 36. Therefore, since the movable contact 32 and the fixed contacts 37 and 38 are in contact with each other and are electrically connected, the parking brake switch is turned on. Here, the movable contact 32 which is a metal plate needs to be stably contacted with two types of fixed contacts, that is, a fixed contact 37 for a body ground which is a nut and a fixed contact 38 for a connector terminal which is a metal plate. Therefore, the structure adopted in the parking brake switch according to the present embodiment is that the connection between the switch shaft 31 and the movable contact 32 which is a metal plate is not completely fixed, but has a degree of freedom. Further, since the urging force of the return spring 36 is applied to the fulcrum (X), which is a connecting portion having a degree of freedom of movement, the movable contact 32 is centered on the fulcrum (X) with respect to the switch shaft 31. As a result, a tiltable movement can be obtained. By employing such a structure, the movable contact 32 can make stable contact with both the left and right fixed contacts 37 and 38. With this ingenuity, it was possible to change the structure of the parking brake switch without deteriorating the product quality, and thus it was possible to reduce costs by reducing parts.
[0024]
On the other hand, when an external force is applied to the switch shaft 31, the switch shaft 31 moves downward against the urging force of the return spring 36 as shown in FIG. 37 and 38 become non-contact. Therefore, the parking brake switch is in the “OFF state”.
[0025]
Embodiment 2
Next, a parking brake switch according to another embodiment different from the first embodiment will be described with reference to FIG. 3A shows the “ON state”, and FIG. 3B shows the “OFF state”. Note that members that are the same as or similar to the members described in Embodiment 1 described above are given the same reference numerals, and descriptions thereof are omitted.
[0026]
What is characteristic in the present embodiment is that the movable contact 52 is formed of a spring having a diameter different from that of the return spring 36. By employing springs having different diameters, the contact between the movable contact 52 and the fixed contacts 37 and 38 can be performed more stably. Also, depending on the structure of the parking brake switch and the positional relationship between the movable contact 52 and the fixed contacts 37 and 38, a spring having an appropriate spring constant can be easily adopted for the movable contact 52. It is possible to apply to.
[0027]
In the above-described two embodiments, the case where the nut is used as the member that also serves as the fixed contact for the body ground and the mounting tool has been described. However, the member serving both as the earthing fixed contact and the mounting tool used in the present invention is not limited to the nut illustrated in the above-described embodiment, and may be, for example, a grounding fixed contact such as a clip made of a conductive metal. It is also possible to use a member that can exhibit two types of functions, that is, a mounting device.
[0028]
【The invention's effect】
As described above, according to the present invention, a nut that has been conventionally installed as a mounting device and a fixed contact that has also been used as a body ground have been used as a common member for fixing a parking brake switch. As a result, the number of parts can be reduced. In addition, by devising a mounting position of a member (for example, a nut or a clip) having both a function as a fixed contact and a function as a mounting tool, the mounting direction of the parking brake switch can be in both left and right directions. Therefore, it is possible to provide a parking brake switch that realizes cost reduction as compared with the conventional parking brake switch.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a parking brake switch according to a first embodiment.
FIGS. 2A and 2B are schematic cross-sectional views illustrating the structure of the parking brake switch according to the first embodiment, where FIG. 2A illustrates an “ON state” and FIG. 2B illustrates an “OFF state”.
3A and 3B are schematic cross-sectional views illustrating the structure of a parking brake switch according to a second embodiment, in which FIG. 3A illustrates an “ON state” and FIG. 3B illustrates an “OFF state”.
FIG. 4 is an exploded perspective view of a conventional parking brake switch.
FIG. 5 is a schematic cross-sectional view illustrating a structure of a movable contact in a conventional parking brake switch.
6A and 6B are schematic cross-sectional views illustrating the structure of a contact portion of a conventional parking brake switch. FIG. 6A illustrates an “ON state”, and FIG. 6B illustrates an “OFF state”.
[Explanation of symbols]
10, 30 switch case, 11, 31 switch shaft, 12 movable contact, 13 movable contact fixing spring, 14, 32, 52 movable contact, 15 holding member, 16, 36 return spring, 17, 37 body ground fixing Contact, 17a hole, 17b, 18b opening, 18, 38 fixed contact for connector terminal, 18a terminal, 19 fixed contact, 21, 41 switch cover, 30a mounting hole.

Claims (2)

A switch shaft,
A movable contact installed on the switch shaft under the biasing force of a return spring;
A fixed contact fixedly installed at a position that can be separated from and contacted with the movable contact,
Has,
A parking brake switch in which a fixed contact and a movable contact perform a switching operation when a switch shaft is pressed and released from the outside according to an operation of a parking brake,
The fixed contact is composed of two members, a fixed contact for a connector terminal and a fixed contact for body ground, which are installed at substantially the same distance from the movable contact,
The body ground fixed contact has a function as a mounting device for a parking brake switch by being configured with a nut made of a conductive metal, and further,
The movable contact can be stably contacted with the fixed contact by being attached to the switch shaft so as to be tiltable by receiving a biasing force from a return spring;
A parking brake switch characterized by the above-mentioned. A switch shaft,
A movable contact installed on the switch shaft under the biasing force of a return spring;
A fixed contact fixedly installed at a position that can be separated from and contacted with the movable contact,
Has,
A parking brake switch in which a fixed contact and a movable contact perform a switching operation when a switch shaft is pressed and released from the outside according to an operation of a parking brake,
The fixed contact is composed of two members, a fixed contact for a connector terminal and a fixed contact for body ground, which are installed at substantially the same distance from the movable contact,
The body ground fixed contact has a function as a mounting device for a parking brake switch by being configured with a nut made of a conductive metal, and further,
The movable contact is configured by a spring having a diameter different from that of the return spring, so that the movable contact can be stably contacted with the fixed contact.
A parking brake switch characterized by the above-mentioned.

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