JP2007018805A - Switch device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switch device capable of improving changeover accuracy between a non-detection state and a detection state of a magnetic detection element, and of appropriately protecting the magnetic detection element from influence of a disturbance magnetic field. <P>SOLUTION: When a permanent magnet 5 is moved to a slide hole 7 equivalent to a first position, a magnetic circuit B1 is formed by a frame-like magnetic body 3 and the permanent magnet 5, and the magnetic field of the permanent magnet 5 is intensively given to the frame-like magnetic body 3. When the permanent magnet 5 is moved to an opening 8 equivalent to a second position so as to be inserted therein, a magnetic circuit is formed by plate-like magnetic bodies 4a and 4b, a Hall element 2 and the permanent magnet 5, and the magnetic field of the permanent magnet 5 is intensively given to the Hall element 2. Since the Hall element 2 is surrounded by the frame-like magnetic body 3, it is protected by the frame-like magnetic body 3 even when a disturbance magnetic field is generated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a switch device configured to switch a magnetic detection element between a non-detection state and a detection state by moving a permanent magnet toward and away from the magnetic detection element.

  This type of switch device is movable with respect to the magnetic detection element in conjunction with, for example, a magnetic detection element arranged in a fixed state on a control board for controlling an in-vehicle device, and an operation element of the switch device. And a permanent magnet provided. When the permanent magnet is moved away from or close to the magnetic detection element in accordance with the operation of the operation element, the strength of the magnetic field applied from the permanent magnet to the magnetic detection element (in other words, the magnetic detection element detects the magnetic field). The strength of the magnetic field to be changed). The magnetic detection element is in a non-detection state if the strength of the applied magnetic field is less than or equal to a predetermined threshold value, and is in a detection state if the strength of the applied magnetic field is greater than or equal to the predetermined threshold value. Thus, the switch device is configured to perform the switch function based on which state the magnetic detection element is in (see, for example, Patent Document 1).

Since the switch device having the above-described configuration has excellent durability without being able to perform the switch function due to wear between the contacts as in the switch device having a mechanical contact structure, the vehicle is particularly required to have durability. It is used in switch devices for equipment.
Further, in the switch device having such a configuration, the magnetic detection element is surrounded by a magnetic body in order to prevent the magnetic detection element from detecting a disturbance magnetic field generated from the outside of the switch device and malfunctioning. In some cases, the magnetic detection element is protected from the influence of a disturbance magnetic field.
JP 2003-115229 A

By the way, in recent years, there is a tendency for the switch device itself to be miniaturized, and accordingly, the moving distance of the permanent magnet with respect to the magnetic detection element is shortened, and the distance between the magnetic detection element and the magnetic material protecting it is also narrowed. ing.
However, such a configuration has the following drawbacks.
Since the moving distance of the permanent magnet with respect to the magnetic detection element is short, even if the permanent magnet is moved, the amount of change in the strength of the magnetic field applied to the magnetic detection element is small and There are cases where a magnetic field below or above a predetermined threshold cannot be properly applied. In addition, since the gap between the magnetic detection element and the magnetic body is narrow, the magnetic field of the permanent magnet is attracted not to the magnetic detection element side but to the magnetic body side, so that a sufficient magnetic field is not applied to the magnetic detection element. There is. For this reason, the switching accuracy between the non-detection state and the detection state of the magnetic detection element may be deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the switching accuracy between the non-detection state and the detection state of the magnetic detection element, and to prevent the magnetic detection element from being affected by a disturbance magnetic field. It is an object of the present invention to provide a switch device that can be appropriately protected from the influence.

  In order to achieve the above-described object, the switch device according to the present invention is configured such that when the permanent magnet is moved to the first position separated from the magnetic detection element, the magnetic detection element is in a non-detection state, while the permanent magnet is In the switch device configured such that when the magnetic detection element is moved to the second position close to the magnetic detection element, the magnetic detection element is disposed so as to surround the magnetic detection element, and the permanent magnet is disposed in the first position. When the permanent magnet is moved to the second position, the first magnetic body that forms a magnetic circuit together with the permanent magnet and the magnetic detection element are disposed between the first magnetic body and the permanent magnet. It has the characteristics provided with the 2nd magnetic body which forms a magnetic circuit with an element and the said permanent magnet.

  With this configuration, in the state where the permanent magnet is moved to the first position and the magnetic circuit is formed together with the first magnetic body, the magnetic field of the permanent magnet forms the first part of the magnetic circuit. Of magnetic material. Therefore, the magnetic detection elements not involved in the formation of the magnetic circuit are not applied with a magnetic field of a predetermined threshold value or more and are not detected. On the other hand, in the state where the permanent magnet is moved to the second position and the magnetic circuit is formed together with the second magnetic body and the magnetic detecting element, the magnetic field of the permanent magnet forms a part of the magnetic circuit. It is given intensively to the element. Therefore, the magnetic detection element is appropriately given a magnetic field equal to or greater than a predetermined threshold value to enter a detection state.

  According to the switching device of the present invention, in the state where the permanent magnet is moved to the first position, the magnetic field of the permanent magnet has little or no effect on the magnetic detection element, while the permanent magnet is in the second position. When moved to the position, the magnetic field of the permanent magnet acts on the magnetic detection element efficiently. Thereby, the switching accuracy between the non-detection state and the detection state of the magnetic detection element can be improved. In addition, since the first magnetic body is arranged so as to surround the magnetic detection element, the magnetic detection element can be appropriately protected from the influence of the disturbance magnetic field.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2, the switch device 1 of the present invention includes a Hall element 2 (corresponding to a magnetic detection element), a frame-like magnetic body 3 (corresponding to a first magnetic body), and a pair of plate-like magnetic bodies 4a and 4b. (Corresponding to a second magnetic body) and a permanent magnet 5.

The Hall element 2 is arranged in a fixed state on, for example, a control board 6 for controlling an in-vehicle device, and is in a non-detection state if the applied magnetic field strength is equal to or less than a predetermined threshold value. If the strength of the magnetic field is equal to or greater than a predetermined threshold value, the detection state is set. The switch device 1 can perform a switch function based on which state of the Hall element 2 is.
The frame-shaped magnetic body 3 has a rectangular frame shape as a whole, and is arranged in a fixed state on the control board 6 so as to surround the Hall element 2 described above. Further, a slide hole 7 opened in the direction of arrows A1 and A2 in the drawing is provided on one end side (right side in the drawing) of the frame-like magnetic body 3. The slide hole 7 corresponds to the first position in the present invention.
Each of the plate-like magnetic bodies 4a and 4b has a rectangular plate shape as a whole, and a part (the left portion in the drawing) sandwiches the above-described Hall element 2 and is on the control board 6 described above. Arranged in a fixed state. Further, the remaining part (the right part in the drawing) of the plate-like magnetic bodies 4a and 4b protrudes from the Hall element 2 in the direction of the arrow A2 in the drawing to form an opening 8 that faces the slide hole 7 described above. . The opening 8 corresponds to the second position in the present invention.

  The permanent magnet 5 is disposed in a fixed state at the end portion (left end portion in the drawing) of the shaft portion 9a of the slider 9 that functions as an operator of the switch device 1. Then, as the slider 9 is reciprocated in the directions of arrows A1 and A2 in the drawing in a manner in which the shaft portion 9a is inserted into the slide hole 7 described above, the permanent magnet 5 has the first position shown in FIG. It is provided so as to be able to reciprocate between the second position shown in FIG. Further, the permanent magnet 5 is urged together with the slider 9 in the direction of the arrow A2 by the compression coil spring 10 wound around the shaft portion 9a of the slider 9. The permanent magnet 5 is magnetized in a direction substantially perpendicular to the moving direction of the slider 9 (the vertical direction in the drawing, in this case, the upper side is N pole and the lower side is S pole). The width a in the magnetization direction of the permanent magnet 5 is set slightly smaller than the opening width b of the slide hole 7 and the opening width c of the opening 8 (see FIG. 1).

Next, the operation of the above configuration will be described.
In FIG. 1, the permanent magnet 5 is moved to a first position separated from the Hall element 2. In this state, the width a in the magnetization direction of the permanent magnet 5 is set slightly smaller than the opening width b of the slide hole 7, so that the frame-shaped magnetic body 3 and the permanent magnet 5 are in close proximity. Thus, the frame-shaped magnetic body 3 forms a magnetic circuit B1 together with the permanent magnet 5. In the magnetic circuit B1, the magnetic field of the permanent magnet 5 flows in the order of the N pole of the permanent magnet 5 → the frame-shaped magnetic body 3 → the S pole of the permanent magnet 5, and forms a part of the magnetic circuit B1. The concentrated magnetic body 3 is given intensively. Therefore, the Hall element 2 that is not involved in the formation of the magnetic circuit B1 is not applied with a magnetic field of a predetermined threshold value or more and is in a non-detected state.

  Next, when the slider 9 is pressed against the urging force of the compression coil spring 10 and moved in the direction of the arrow A1 in FIG. 1 from this state, the permanent magnet 5 is opened in conjunction with the movement of the slider 9. 8 and is moved to a second position close to the Hall element 2 (see FIG. 2). In this state, since the width a in the magnetization direction of the permanent magnet 5 is set slightly smaller than the opening width c of the opening 8, the plate-like magnetic bodies 4 a and 4 b and the permanent magnet 5 are in close proximity. Thereby, the plate-like magnetic bodies 4 a and 4 b together with the Hall element 2 and the permanent magnet 5 form a magnetic circuit B 2. In the magnetic circuit B2, the magnetic field of the permanent magnet 5 is recirculated in the order of the N pole of the permanent magnet 5 → the plate-like magnetic body 4a → the Hall element 2 → the plate-like magnetic body 4b → the S pole of the permanent magnet 5. It is given intensively to the Hall element 2 that forms part of the magnetic circuit B2. Therefore, the Hall element 2 is appropriately detected with a magnetic field equal to or greater than a predetermined threshold.

  As described above, according to the present embodiment, when the permanent magnet 5 is moved to the first position separated from the Hall element 2, the magnetic field of the permanent magnet 5 is little or not at the Hall element 2. On the other hand, when the permanent magnet 5 is moved to the second position close to the Hall element 2, the magnetic field of the permanent magnet 5 efficiently acts on the Hall element 2. Thereby, the switching accuracy between the non-detection state and the detection state of the Hall element 2 can be improved. In addition, since the frame-shaped magnetic body 3 is disposed so as to surround the Hall element 2, the Hall element 2 can be appropriately protected from the influence of the disturbance magnetic field.

In addition, this invention is not limited only to above-described embodiment, It can deform | transform or expand as follows.
The magnetic detection element is not limited to the Hall element 2 described above, and operates by applying a magnetic field such as an MR (magnetoresistive effect) element, a GMR (giant magnetoresistive effect) element, or a reed switch. I just need it.
What is necessary is just to comprise as a 1st magnetic body and a 2nd magnetic body by what has the property magnetized in a magnetic field like iron, nickel, cobalt, a ferrite, an amorphous magnetic body, etc., for example. Further, the shape is not limited to the above-described frame shape or plate shape, and may be any shape that can form the magnetic circuit at the first position and the second position.

The magnetization direction of the permanent magnet 5 is not limited to the direction substantially orthogonal to the moving direction of the slider 9, but is magnetized in a direction in which a magnetic circuit can be formed at the first position and the second position. Anything is fine.
The switch device 1 according to the present invention can be used in various switches such as a buckle switch, a courtesy switch, a stop lamp switch, a push start switch, and a neutral position switch by appropriately changing the type of the control board 6 and the shape of the slider 9. It can be applied to the device.

Sectional drawing which shows one Embodiment of this invention and shows the state by which the permanent magnet was moved to the 1st position Sectional drawing which shows the state by which the permanent magnet was moved to the 2nd position

Explanation of symbols

  In the drawings, 1 is a switching device, 2 is a Hall element (magnetic detection element), 3 is a frame-like magnetic body (first magnetic body), 4a and 4b are plate-like magnetic bodies (second magnetic body), 5 is A permanent magnet is shown.

Claims (1)

When the permanent magnet is moved to a first position separated from the magnetic detection element, the magnetic detection element is in a non-detection state, while when the permanent magnet is moved to a second position close to the magnetic detection element. In the switch device configured so that the magnetic detection element is in a detection state,
A first magnetic body disposed surrounding the magnetic detection element and forming a magnetic circuit with the permanent magnet when the permanent magnet is moved to the first position;
The magnetic detection element is disposed so as to sandwich the magnetic detection element, and includes the second magnetic body that forms a magnetic circuit together with the magnetic detection element and the permanent magnet when the permanent magnet is moved to the second position. A switch device characterized.

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