JP2006310226A - Microswitch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microswitch having a large operation stroke and a long service life. <P>SOLUTION: The microswitch is composed of fixed contact points 6b and 7b fixed at specified points and a leaf spring, and has a contact spring 9 having a movable contact point 9d contacting a fixed contact point 6b by its own restoring force or a movable contact point 9c contacting a fixed contact point 7b when deformed due to resisting a restoring force, and an operation knob 3 which moves toward a direction crossing the axis of movement of the contact points 9c, 9d and slides and contacts the contact spring 9, and an energizing part 8 which energizes the operation knob b in a direction which allows the restoration of the contact spring. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a microswitch.

In recent years, in order to reduce the noise of an apparatus, a microswitch of a type that restores to an initial state when an operation force is released by avoiding a microswitch having a snap mechanism with an operation sound is often used. Examples of such microswitches are described in US Pat.
JP-A-11-260201 Japanese Patent Laid-Open No. 2001-184994 JP-A-2001-297660 Japanese Patent Laid-Open No. 2004-185925

  The microswitch described in Patent Documents 1 to 3 is provided with a contact spring having a movable contact that is made of a conductive leaf spring housed in a case and that can be brought into contact with a fixed contact at an end thereof. Thus, the contact spring is deformed against the restoring force, so that the movable contact is slid on the inner wall of the case to abut or separate from the fixed contact.

  Such a micro switch has a short life because the movable contact of the contact spring slides, and the contact is likely to be worn. In addition, there may be a problem that the contacts are short-circuited by the wear powder generated by the wear of the contacts.

  The microswitch described in Patent Document 4 is provided with a contact spring having a movable contact made of a leaf spring and abutting on a fixed contact arranged in its own restoring direction in a case. Then, the contact spring is deformed by the operating member in the direction in which the movable contact is separated from the fixed contact, and the contact is separated by the operating member.

  Such a microswitch has a problem that since the moving distance of the movable contact is small, the operation stroke is small and a good operation feeling cannot be obtained.

  In view of the above problems, an object of the present invention is to provide a microswitch having a long operation stroke and a long life.

  In order to solve the above problems, a microswitch according to the present invention comprises a fixed contact fixed at a fixed position and a leaf spring, and abuts against the fixed contact by its own restoring force or resists the restoring force. A contact spring having a movable contact that comes into contact with the fixed contact when deformed in a deformed manner, and moving in a direction intersecting the moving direction of the movable contact and slidingly contacting the contact spring, thereby restoring the restoring force of the contact spring. And an urging member that urges the operation member in a direction to restore the contact spring.

  According to this configuration, since the restoring force of the contact spring for pressure contact or separation with respect to the fixed contact of the movable contact is not used for returning the operation member, the operation member is returned to the initial position by the separately provided biasing member. The moving direction of the movable contact of the contact spring is different from the moving direction of the operating member. Accordingly, since the contact spring and the operation member are in sliding contact with each other, the movement amount of the operation member is larger than the movement amount of the movable contact, although the leaf contact mechanism does not slide. For this reason, although it is a small microswitch, the operation stroke is large, and it is possible to provide a good operation feeling that allows the user to feel the operation of the switch. Further, since the movable contact does not slide, the wear of the contact is slight, the life is long, and a short circuit due to wear powder does not occur.

  In the microswitch of the present invention, if the operation member moves in a direction substantially orthogonal to the movement direction of the movable contact, the operation member movement amount with respect to the deformation amount of the contact spring becomes larger. The operation stroke is long and the operation feel is good.

  In the microswitch of the present invention, if the operation member has an operation surface that is parallel to the moving direction and that is in sliding contact with the contact spring, the operation surface of the operation member is in sliding contact with the contact spring. Does not change the amount of deformation of the contact spring. For this reason, when the contact spring is deformed by the operation member and the movable contact is brought into contact with the fixed contact, so-called A contact is configured, the surplus stroke of the operation member after the movable contact comes into contact with the fixed contact can be lengthened. The operation feeling is improved. In addition, since it contacts the fixed contact in a wide range of the operation surface, the operation member will not be partially worn, the operation stroke will not change, and the deformation amount of the contact spring will not be insufficient, causing malfunction. .

  In the microswitch of the present invention, if the contact spring has a passive surface parallel to the moving direction of the operation member in a state where the contact spring is most deformed by the operation member in sliding contact, the operation member is on the passive surface. The amount of deformation of the contact spring does not change while sliding. For this reason, when the contact spring is deformed by the operation member and the movable contact is brought into contact with the fixed contact, so-called A contact is configured, the surplus stroke of the operation member after the movable contact comes into contact with the fixed contact can be lengthened. The operational feeling becomes even better.

Embodiments of the present invention will now be described with reference to the drawings.
1 and 2 are a front view and an exploded perspective view of a microswitch 1 according to one embodiment of the present invention. The micro switch 1 includes a resin case 2 that houses other components, a resin operation member 3 that protrudes from the case 2 at one end, a resin base 4 that seals the opening of the case 2, a base Metal common electrode 5, A contact terminal 6 and B contact terminal 7, which are inserted and fixed respectively at the time of molding 4; return spring 8 which urges operation member 3 in the direction of projecting from case 2, and metal Of the U-shaped leaf spring and a rubber dust cap 10 that seals the opening of the case 2 through which the operation member 3 passes.

  3 and 4 show the relationship among the common electrode 5, the A contact terminal 6, the B contact terminal 7, and the contact spring 8. FIG. FIG. 3 shows a state in which the respective contacts 5, 6, 7 are fixed to the base 4, and FIG. 4 also shows a structure of a portion hidden by the base 4 of each electrode 5, 6, 7. The base 4 supports the electrodes 5, 6, and 7 so as not to be in direct contact with each other, and is provided with a spring seat 4 a with which one end of the return spring 8 is engaged. The plate-like electrodes 5, 6, 7 are arranged on the same plane outside the case 2, but are bent inside the base 4, and inside the case 2, contact support portions located on mutually different parallel surfaces 5a, 6a, 7a. The contact support portion 6a of the A contact terminal 6 is provided with a fixed contact 6b made of a copper member on the surface of the B contact terminal 7 on the contact support portion 7a side, and the contact support portion 7a of the B contact terminal 7 has a contact A fixed contact 7b made of a copper member is provided on the surface of the support portion 6a. Further, one end of the contact spring 9 is fixed to the contact support portion 5 a of the common electrode 5. The contact spring 9 is a substantially U-shaped leaf spring having an unfixed free end extending between the contact support portion 6a and the contact support portion 7a. The contact spring 9 is protruded outward by an inclined portion 9a in the vicinity of the free end. A planar passive surface 9b. The free end of the contact spring 9 is provided with a movable contact 9c made of a copper member at a position facing the fixed contact 7b and a movable contact 9c made of a copper member at a position facing the fixed contact 6b. Yes. The contact spring 9 has a restoring force in a direction in which the free end moves away from the contact support portion 5a, and the movable contact 9c is in pressure contact with the fixed contact 7b.

  Next, FIG. 5 shows the operation member 3 in an enlarged manner. The operating member 3 includes a shaft portion 3a protruding from the case 2, a moving body portion 3b provided at a lower end portion of the shaft portion 3a, and an operating projection portion protruding sideways from the moving body portion 3b and contacting the contact spring 9. 3c. Sliding grooves 3d and 3d parallel to the shaft portion 3a are provided on the front and back surfaces of the movable body portion 3b facing each other. The operation protrusion 3c has an operation surface 3e that contacts the contact spring 9 and is parallel to the shaft 3a.

  Further, FIG. 6 shows the inside of the case 2. The inner wall of the case 2 is provided with a guide portion 2a that engages with the sliding groove 3d of the operation member 3 and guides the operation member 3 to linearly move in the axial direction. Moreover, the groove | channel 2b which reaches a ceiling surface is arranged in parallel at the corner of the inner wall and both sides of the guide portion 2a. The groove 2b is configured so that when the base 4 is fitted into the case 2 and a permeable sealing agent is poured into the gap between the two, even if the sealing agent enters along the corner of the inner wall of the case 2, the moving body The relief of the sealing agent is provided so that the sealing agent does not adhere to 3b.

  FIG. 7 shows an AA cross section of the microswitch 1 of FIG. The movable body portion 3b of the operation member 3 has a box shape with an open bottom, and a spring seat 3f with which the upper end of the return spring 8 is engaged is provided inside.

Next, the operation of the microswitch 1 having the above configuration will be described.
In FIG. 7, when the upper end of the operation member 3 is pressed, the sliding groove 3 d is guided by the guide 2 a of the case 2, and moves straight downward against the urging force of the return spring 8. At this time, the dust cover 10 is freely deformed to seal the gap between the operation member 3 and the case 2. When the force to depress the operating member 3 is removed, the return spring 8 pushes up the operating member 3 so as to protrude from the case 2 as shown in FIG.

  Next, FIG. 8 shows a normal BB cross section in which the operation member 3 of the microswitch 1 of FIG. 1 is not pressed. At this time, due to the restoring force of the contact spring 9, the movable contact 9 c is pressed against the fixed contact 7 b connected to the B contact terminal, and the movable contact 9 d is separated from the fixed contact 6 b connected to the A contact terminal 6. In this state, the A contact terminal 6 is not electrically connected to the shared electrode 5, and the B contact terminal 7 is electrically connected to the shared electrode 5 via the contact spring 9.

  Here, when the upper end of the operation member 3 is pushed down, the operation protrusion 3 c comes into contact with the inclined portion 9 a of the contact spring 8. The operation protrusion 3c slides on the contact spring 9 so as to push the inclined portion 9a and then the operation surface 9b, and descends while bending the contact spring 9 little by little. In the microswitch 1, for example, when the operation member 3 is pushed down about 0.5 mm from the state of FIG. 8, the movable contact 9 c is separated from the fixed contact 7 b, and the common electrode 5 becomes non-conductive with the B contact terminal. Further, in the microswitch 1, when the operation member 3 is pushed down by 0.3 mm and a total of 0.8 mm from the state of FIG. 8, the movable contact 9d comes into contact with the fixed contact 6b, and the common electrode 5 passes through the contact spring 9. To the A contact terminal 6. During this time, the movable contacts 9c and 9d move about 0.2 mm in a direction substantially perpendicular to the moving direction of the operation member 3.

  As shown in FIG. 9, when the operation member 3 is further lowered, the U-shaped portion of the contact spring 9 is further compressed, but the portion beyond the passive surface 9b is expanded by the fixed contact 6b. Due to the elastic deformation of the tip, a contact pressure of the movable contact 9d against the fixed contact 6b is generated. At this time, the passive surface 9b is designed to be substantially parallel to the moving direction of the operation member 3, and as shown in the figure, the operation surface 3e of the operation member 3 and the passive surface 9b of the contact spring 9 are in a wide range. Touch with. Further, as shown in FIG. 10, even when the operation member 3 is pushed down to the maximum, the operation surface 3e and the passive surface 9b are in sliding contact with each other, and the shape of the operation member 3 hardly changes during this time, and the movable contact 9d The contact pressure between the fixed contact 6b and the fixed contact 6b is constant. Therefore, in the microswitch 1, from the state of FIG. 8 to the state of FIG. 10, the operation member 3 can be pushed down by about 3 mm at the maximum, and after the common electrode 5 and the A contact terminal 6 are conducted, about 2.2 mm. There is an extra stroke.

  When the external force that pushes down the operation member 3 is removed, the operation member 3 is pushed up to the position shown in FIG. 8 by the urging force of the return spring 8. As the operation protrusion 3c moves backward, the contact spring 9 is restored so as to widen the U-shape by the restoring force of itself, and the movable contact 9d moves away from the fixed contact 6b, and the movable contact 9c. Contacts the fixed contact 7b. In other words, the shared electrode 5 becomes non-conductive with the A contact terminal 6 and becomes conductive with the B contact terminal.

  As described above, in the microswitch 1, the operator feels a sufficient operational feeling as the operation stroke of the operation member 3 even though the moving distance of the movable contacts 9c and 9d is only 0.2 mm. As a whole, 3 mm is secured. In addition, it is easy to change the invalid stroke from when the operation member 3 starts to be pushed down until the change in the contact state occurs, and the extra stroke after the contact state is changed, depending on the design.

  Further, since the movable contacts 9c and 9d do not slide with respect to the fixed contacts 6b and 7b, there is little wear, the life is long, and there is no possibility of short circuit due to wear powder. Furthermore, since the deformation amount of the contact spring 9 is small, the life of the contact spring 9 is also long. Moreover, since the resin-made operation member 3 is slidably contacted with the contact spring 9 by the operation surface 3e, there is an advantage that the local wear is small and the life is long.

The front view of the microswitch of this invention. The disassembled perspective view of the microswitch of FIG. The perspective view of the base which shows the relationship between the movable contact of FIG. 2, and a fixed contact. The perspective view which shows the relationship between each electrode of FIG. 2, a fixed contact, and a fixed contact. The expansion perspective view of the operation member of FIG. The perspective view which shows the inner side of the case of FIG. FIG. 2 is an AA cross-sectional view of the microswitch of FIG. 1. The BB cross-sectional arrow view of the normal time of the microswitch of FIG. The BB cross-sectional arrow figure at the time of operation | movement of the microswitch of FIG. The BB cross-sectional arrow figure after the operation | movement of the microswitch of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Micro switch 2 Case 3 Operation member 3a Operation protrusion part 3c Operation surface 4 Base 5 Shared electrode 6 A contact terminal 6b Fixed contact 7 B Contact terminal 7b Fixed contact 8 Return spring 9 Contact spring 9b Passive surface 9c Movable contact 9d Movable contact 10 Dustproof cap

Claims (4)

A fixed contact fixed in place;
A contact spring comprising a leaf spring and having a movable contact that abuts against the fixed contact by its own restoring force or abuts against the fixed contact when deformed against the restoring force;
An operation member that moves in a direction intersecting with the moving direction of the movable contact and slidably contacts the contact spring, thereby deforming the contact spring against a restoring force;
A biasing member that biases the operating member in a direction to restore the contact spring;
A microswitch characterized by comprising:   The microswitch according to claim 1, wherein the operation member moves in a direction substantially orthogonal to a moving direction of the movable contact.   The microswitch according to claim 1, wherein the operation member has an operation surface that is parallel to a moving direction thereof and that is in sliding contact with the contact spring.   4. The microswitch according to claim 1, wherein the contact spring has a passive surface parallel to a moving direction of the operation member in a state where the contact spring is most deformed by the operation member in sliding contact. .

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