JP2007207712A - Double action switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double action switch whose structure of a first switch being operated in accordance with a pushing operation of an operation part to a first pushing position is improved and whose operation strokes can be reduced. <P>SOLUTION: In the double action switch, a first switch operation and a second switch operation are conducted each in accordance with a pushing operation of the operation part 17e to a first pushing position and a second pushing position. In accordance with the pushing operation of the operation part 17e, the first switch operation is conducted as a magnetic shielding member 22 is located between a magnet 20 and a magnetic detecting element 21 and shields magnetic field. Unlike in a conventional double action switch, an operation stroke to apply an contact pressure so that first fixed contact points can be bridged firm even after a first movable contact point contacts with first fixed contact points is dispensed with and, thus, operation strokes can be reduced and an operator friendliness can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a double action switch having an improved structure for performing a first switch operation in response to a pressing operation to a first pushing position of an operation unit.

Conventionally, for example, a double action switch used to operate a vehicle navigation system such as an automobile, a power window, an electric mirror, or a general camera has a first push-in position from the source position and a second push-in switch ahead of the first push-in position. An operation unit that is operated to be pressed to the pushing position is provided, and the first switch operation and the second switch operation are respectively performed in response to the pressing operation of the operation unit to the first pushing position and the second pushing position. It is what you do.
FIG. 4A shows a conventional structure of such a double action switch, and an operation member 2 is provided on a circuit board 1. The circuit board 1 has first fixed contacts 3 and 4 spaced apart from each other on the upper surface, and second fixed contacts 5 and 6 between them.

On the other hand, the operating member 2 has a ring-shaped base portion 2a at the lowermost portion, and has a first elastic deformation portion 2b formed of a skirt-like thin portion on the base portion 2a, and a thick ring on the first elastic deformation portion 2b. The portion 2c is further provided with a second elastic deformation portion 2d composed of a thin skirt-like portion having a diameter smaller than that of the first elastic deformation portion 2b, and an operation portion 2e having a substantially cylindrical shape on the top portion. have. Thus, the operation member 2 as a whole is made of an elastic material such as rubber, the ring-shaped first movable contact 7 is provided on the lower surface of the ring portion 2c, and the disk-shaped second is formed on the lower surface of the operation portion 2e. A movable contact 8 is provided.
The operation member 2 is fixed to the circuit board 1 by the base portion 2a, the first movable contact 7 is opposed to the first fixed contacts 3 and 4, and the second movable contact 8 is fixed to the second. The contacts 5 and 6 are opposed to each other.

In this configuration, the operation section 2e from the source position shown in FIG. 3 (a), when pressed, as shown by the arrow X ₁ in FIG. 3 (b), initially the first elastic deformation portion 2b is elastically The first movable contact 7 is deformed to come into contact with the first fixed contacts 3 and 4 and bridges between the first fixed contacts 3 and 4. This position is the first pushing position, and the bridge between the first fixed contacts 3 and 4 by the first movable contact 7 at this time is the first switch operation.

Then, when further pressed as indicated by the arrow X ₂ in FIG. 3 (c) the operation section 2e, a second movable contact 8 second elastic deformation portion 2d is elastically deformed second fixed contact 5 6 and the second fixed contacts 5 and 6 are bridged. This position is the second pushing position, and the bridge between the second fixed contacts 5 and 6 by the second movable contact 8 at this time is the second switch operation (see, for example, Patent Document 1).
JP-A-8-111134

  FIG. 5 shows the relationship between the first and second switch operations and operation strokes and the operation load in the conventional double action switch. In the figure, point A is the source position, and point B ′ is the first pushing position. Specifically, the first movable contact 7 comes into contact with the first fixed contacts 3 and 4 at a point B before the point B ′ by Δs in the operation stroke. In order to reliably bridge the first fixed contacts 3 and 4 with the first movable contact 7 in contact with each other, a contact pressure obtained by adding an operation load corresponding to an operation stroke of Δs is required. The first fixed contacts 3 and 4 are reliably bridged (ON) at the point B ′ after the operating stroke of Δs from the point B. Specifically, for example, the operation stroke s from point A to point B is 0.3 [mm], and the operation stroke Δs from point B to point B ′ is about 0.2 [mm].

After that, by continuing the pressing operation of the operation portion 2e, the operation load continues to increase, and when the point C is reached, the second elastic deformation portion 2d is elastically deformed and buckles, and then the operation load is reduced. A click feeling is obtained at this time. Then, at the point D, the second movable contact 8 comes into contact with the second fixed contacts 5 and 6. In order to reliably bridge between the second fixed contacts 5 and 6 by the contacted second movable contact 8, a contact pressure to which an operation load corresponding to an operation stroke of Δt is added is necessary. The second fixed contacts 5 and 6 are reliably bridged (ON) at the point D ′ after the operating stroke of Δt from the point. That is, the point D ′ is the second pushing position.
Thereafter, if the pressing operation of the operation unit 2e is continued, the operation load increases.

  As described above, in the conventional double action switch, the operation stroke of Δs is necessary after the first movable contact 7 comes into contact with the first fixed contacts 3 and 4, and the second movable contact 8 is Even after contacting the second fixed contacts 5 and 6, an operation stroke of Δt is necessary, and the entire operation stroke is required correspondingly.

  The present invention has been made in view of the above circumstances, and therefore an object of the present invention is to provide a double action switch capable of reducing the operation stroke.

  In order to achieve the above object, a double action switch according to the present invention comprises an operation unit that is operated to be pressed from a source position to a first pushing position and a second pushing position ahead of the first pushing position. In the first switch operation and the second switch operation in response to the pressing operation to the first push position and the second push position, respectively, the first switch action is a magnet, A magnetic detection element that detects magnetism by the magnet, and a magnetic shielding member that is located between the magnet and the magnetic detection element and shields magnetically in accordance with a pressing operation to the first pushing position of the operation unit. It is characterized by having done.

  According to the above means, in the first switch operation, the magnetic shielding member is located between the magnet and the magnetic detection element in accordance with the pressing operation to the first pushing position of the operation unit, and performs magnetic shielding. In order to ensure bridging between the first fixed contacts even after the first movable contact contacts the first fixed contact, which is necessary for the conventional double action switch. Therefore, the operation stroke can be reduced and the operability can be improved.

Hereinafter, an embodiment (one embodiment) of the present invention will be described with reference to FIGS.
First, FIG. 2 shows a configuration including an outer shell of a double action switch, which includes a base 11, a cover 12 attached to the base 11, and a push button 13 incorporated in the cover 12 so as to be able to reciprocate up and down. The outer shell 14 is composed.

  A double action switch 15 is incorporated in the outer shell 14, and the double action switch 15 includes a circuit board 16 and an operation member 17. Among them, the circuit board 16 is embedded in the base 11 with only the upper surface exposed, and fixed contacts 18 and 19 are provided close to the upper surface.

  On the other hand, as shown in FIG. 3, the operating member 17 has a ring-shaped base portion 17a at the lowermost portion, and has a first elastic deformation portion 17b formed of a skirt-like thin portion on the base portion 17a. Further, a thick ring portion 17c is formed thereon, a second elastic deformation portion 17d comprising a skirt-like thin portion having a diameter smaller than that of the first elastic deformation portion 17b, and a top portion above the second elastic deformation portion 17d. A substantially cylindrical operation portion 17e is provided.

  The operation member 17 is made of an elastic material such as rubber as a whole, and the base portion 17a has a magnet 20 embedded in one side (left side in the drawing) opposed to the left and right, and the other side (right side in the drawing). ) Is embedded with the magnetic sensing element 21. In this case, the magnet 20 is a permanent magnet, and the magnetic sensing element 21 is, for example, a GMR (Giant Magnetic Resistance) element. In addition, the magnet 20 may be an electromagnet, and the magnetic detection element 21 may be a Hall element or an MR element.

  A magnetic shielding member 22 is embedded in the ring portion 17c. The magnetic shielding member 22 is made of a magnetic material, in particular, a ferromagnetic material such as iron or nickel. Specifically, for example, four convex portions 22b are arranged at equal intervals on the uppermost portion of the main portion 22a having a short cylindrical shape. The main portion 22a is entirely inserted into the ring portion 17c, and the convex portion 22b is fitted into the groove portion 23 formed at the uppermost portion of the ring portion 17c by means of adhesion or the like. It is stuck. The magnetic shielding member 22 may be fixed to the ring portion 17c by inserting the magnetic shielding member 22 and molding the ring portion 17c (insert molding).

Thus, the magnetic shielding member 22 is provided in the ring portion 17c. Therefore, the ring portion 17c is a magnetic shielding member holding portion, and on the other hand, a disk-shaped movable contact 24 is provided on the lower surface of the operation portion 17e.
As shown in FIG. 2, the operation member 17 is fixed to the circuit board 16 by a base portion 17a, and the movable contact 24 is opposed to the fixed contacts 18 and 19 in the vertical relationship. The push button 13 is located on the operation portion 17e, and the operation member 17 pushes up the push button 13 as a whole.

Next, the operation of the above configuration will be described.
First, FIG. 2 and FIG. 1A show the source state. In this state (source position), the magnetic shielding member 22 is retracted from between the magnet 20 and the magnetic detection element 21 or above the heel. Therefore, although the magnetism by the magnet 20 (indicated by the arrow Z) is partly shielded by the magnetic shielding member 22, most of the magnetism reaches the magnetic sensing element 21, thereby causing a “strong” signal from the magnetic sensing element 21. Is output.

From this state, then when pressed as indicated by the arrow Y ₁ the operation portion 17e in shown in FIG. 1 (b) with pushbutton 13, the first elastically deformable portion 17b is moved down the ring portion 17c is elastically deformed . Then, the magnetic shielding member 22 is positioned between the magnet 20 and the magnetic sensing element 21 so as to almost shield between them, and thus the magnetism by the magnet 20 is almost shielded by the magnetic shielding member 22, thereby The magnetic detection element 21 outputs a “weak” signal. This position is the first pushing position, and the output of the “weak” signal from the magnetic sensing element 21 at this time is the first switch operation. Therefore, at this time, the magnet 20, the magnetic detection element 21, and the magnetic shielding member 22 function as first switch means that performs a first switch operation.

And further, when pressed, as shown by the arrow _{Y 2} in the FIG. 1 (c) an operation portion 17e pushbutton 13, the movable contact 24 second elastically deformable portion 17d is elastically deformed fixed contacts 18 and 19 , And bridges between the fixed contacts 18 and 19. This position is the second pushing position, and the bridge between the fixed contacts 18 and 19 by the movable contact 24 at this time is the second switch operation. Accordingly, at this time, the fixed contacts 18 and 19 and the movable contact 24 function as second switch means for performing a second switch operation.

  The second elastic deformation portion 17d is buckled when elastically deformed as described above, thereby reducing the subsequent operation load, and a click feeling is obtained at this time. Further, the buckling of the second elastically deforming portion 17d generally occurs after the ring portion 17c contacts the circuit board 16, but may be configured to occur before contacting.

  Thus, in this configuration, the first switch operation is performed when the magnetic shielding member 22 is positioned between the magnet 20 and the magnetic detection element 21 in accordance with the pressing operation to the first pressing position of the operation unit 17e. The first fixed contact after the first movable contact 7 comes into contact with the first fixed contacts 3 and 4, which is accomplished by magnetic shielding and is necessary in the conventional double action switch. Since there is no need for an operation stroke to apply contact pressure in order to bridge between 3 and 4 with certainty, the operation stroke can be reduced correspondingly and the operability can be improved.

Note that the second switch operation is not limited to the bridge between the fixed contacts 18 and 19 by the movable contact 24. For example, the degree of magnetic shielding by the magnetic shielding member 22 is made different from the first switch operation. Alternatively, it may be performed by other means such as a change in the degree of arrival of light from the light emitting element to the light receiving element.
In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view of the principal part which shows one Example of this invention, (a) is a figure of a source state, (b) is a figure of a 1st pushing state, (c) is a figure of a 2nd pushing state. Overall longitudinal section Plan view of main parts 1 equivalent diagram showing a conventional example The figure which showed the 1st and 2nd switch operation | movement of a prior art example, and the relationship between operation stroke and operation load.

Explanation of symbols

  In the drawing, 15 is a double action switch, 17e is an operation unit, 18 and 19 are fixed contacts, 20 is a magnet, 21 is a magnetic sensing element, 22 is a magnetic shielding member, and 24 is a movable contact.

Claims (1)

An operation unit that is pressed from the source position to the first push position and the second push position ahead of the first push position is provided, and the operation unit is operated to push the first push position and the second push position. In response to each of the first switch operation and the second switch operation,
The first switch operation is
A magnet,
A magnetic detecting element for detecting magnetism by the magnet;
A double action switch characterized in that it is operated by a magnetic shielding member that is located between the magnet and the magnetic sensing element and shields magnetically in accordance with a pressing operation to the first pushing position of the operation portion. .

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