JP4853171B2 - switch - Google Patents

Description

  The present invention relates to a switch such as a micro switch, a limit switch, or a push button switch suitable for detecting the position of an operating member in various mechanical devices and various facilities.

As a switch, for example, a micro switch, a switching mechanism is incorporated in a switch case, and a movable piece in the switching mechanism is snapped by a displacement operation of a push button as an actuator to switch conduction between terminals. Is widely used (see, for example, Patent Document 1).
JP 2000-215751 A

  In such a micro switch, a movable piece having a movable contact at the free end is formed of a rigid material that is not elastically deformed. A coil spring is applied to the movable piece, and the movable piece is snapped by expansion and contraction of the coil spring. There is one configured to perform the continuity switching.

  Such a coil spring type switching mechanism is relatively easy to manage the elastic characteristics of the coil spring, and has almost no risk of inadvertently plastically deforming the coil spring during assembly. Since the movable piece having high rigidity is used, when the contact is switched by the snap operation, the movable contact provided at the free end of the movable piece slides relative to the surface of the fixed contact. The wiping operation cannot be performed, and the progress of the welding of the contacts cannot be avoided in advance, and therefore, there is a problem that an expensive material having high hardness and melting temperature must be used as the contact material. is there.

  The present invention has been made paying attention to such a situation, and an object thereof is to provide a switch that enables a wiping operation while utilizing a coil spring type switching mechanism that is easy to manufacture.

(1) In the switch of the present invention, the movable piece of the switching mechanism is snap-operated by the displacement operation of the actuator to switch the conduction between the terminals, and the switching mechanism is provided with a movable contact at the free end. fixed contacts facing the movable piece, the receiving member for swingably supporting the base end of the movable piece with coupled to the terminal, the free end portion of the movable piece with is connected to the other terminal with A fixed piece comprising: an operating piece that is swingably supported by the receiving member and is operated to swing by the actuator; and a coil spring that spans the operating piece and the movable piece, comprising a displacement allowable portion free end of the movable piece by the tension variation of the coil spring is allowed to displace the movable piece longitudinally connecting point of the coil spring to the movable piece, the strange Lies between said permitting portion movable contact.

  According to the present invention, when the movable piece snaps up and down to switch the contact, the coil spring is deformed and the spring tension is changed, so that the displacement allowable portion is slightly operated, and thereby the free end side of the movable piece is movable. Displacement is performed in the longitudinal direction, relative sliding of the movable contact to the fixed contact (wiping operation) is performed, and welding between the contacts is avoided in advance.

  According to this embodiment, since the base end of the movable piece is supported by the receiving member and its position is fixed, only the free end side of the movable piece is displaced in the longitudinal direction of the movable piece, so the position and orientation of the movable piece is stable. Then, an accurate snap operation is performed.

  (3) In a preferred embodiment of the switch of the present invention, the entire movable piece is formed of a spring plate material, and a bent portion is formed between a base end of the movable piece and a connection point of the coil spring to the movable piece. The bent portion is used as the displacement allowable portion.

  According to this embodiment, it is possible to displace the free end side from the bent portion in the longitudinal direction by elastically deforming the bent portion as the displacement allowing portion by the spring tension, and the material setting of the movable piece and simple shape change The desired function can be obtained.

  In this case, the shape accuracy of the bent portion itself is such that the contact position between the movable contact and the fixed contact is affected, and the snap action of the movable piece is not directly involved, and the movable piece can be easily manufactured and assembled. .

  (4) In another embodiment of the switch of the present invention, the receiving member is provided with a receiving piece for locking the base end of the movable piece, and the receiving piece is configured to be elastically deformable to serve as the displacement allowing portion. .

  According to this embodiment, for example, by configuring the receiving member with a spring plate material, it is possible to displace the entire movable piece in its longitudinal direction by elastically deforming the receiving piece as a displacement allowing portion by spring tension, The desired function can be obtained by changing the material of the receiving member and changing the shape of the receiving member.

  According to the present invention, it is possible to perform a wiping operation while using a coil spring type switching mechanism that is easy to manufacture, and it is not necessary to use an expensive contact material as in the prior art, and the cost can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a longitudinal front view of a microswitch according to the present invention, and FIG. 2 shows a perspective view of a state in which the terminal cover 8 is removed and the inside thereof is exposed.

  The microswitch includes a base 1 made of an insulating resin material, three terminals 2, 3, and 4 that are insert-fixed to the base 1, a resin cover case 5 that is externally fitted to the base 1, and the base 1 and the cover case. 5 is a snap-actuated switching mechanism 6 incorporated in a space surrounded by 5, a plastic push button 7 as an actuator slidably mounted on the cover case 5, and a detachable outer part of the base 1. The resin terminal cover 8 is fitted and attached, and the rubber conductive wire seal 9 is attached to one end of the terminal cover 8.

  The terminals 2, 3, and 4 are insert-fixed when the base 1 is molded, and external conductors are connected by terminal screws 10, 11, and 12 attached to the outer ends thereof.

  The switching mechanism 6 includes a receiving member 13 made of a brass thick plate material that is caulked and connected to the inner end portion of the terminal 2 that is a common terminal, and a brass member that is caulked and connected to the inner end portion of the terminal 3 that is a normally closed terminal. A fixed piece 14 made of a thick plate material, a fixed piece 15 made of a thick plate material made of brass caulked and connected to the inner end of the terminal 4 serving as a normally open terminal, and a forward facing of the receiving piece 13a bent up from the front end of the receiving member 13 Stainless steel whose rear end is locked to a rearward notch 18 of a pair of left and right support protrusions 13b bent upright from the base of the receiving member 13 and a movable piece 17 having a bifurcated planar shape whose rear end is locked to the notch 16 It comprises a working piece 19 made of steel, and a coil spring 21 made of stainless steel stretched between a front end portion of the working piece 19 and a spring connecting hole 20 provided at an intermediate position in the longitudinal direction of the movable piece 17. Have .

  The pair of fixed pieces 14 and 15 are arranged so as to be opposed to the free end portion of the movable piece 17 that can swing up and down with a locking point p with the forward notch 16 shown in FIG. Fixed contacts 23 and 24 facing the upper and lower movable contacts 22 provided at the free end of the piece 17 are provided on the respective fixed pieces 14 and 15, and the movable piece 17 swings up and down so that the movable contact 22 is fixed. The contact state between the terminal 2 and the terminal 3 or the conduction state between the terminal 2 and the terminal 4 can be obtained by contacting the contact point 23 or the fixed contact 24.

  The push button 7 is arranged so that the inner end thereof opposes the free end portion of the operating piece 19 from above, and when the push button 7 is pushed and displaced from the outside, the operating piece 19 is notched backwardly as shown in FIG. It is designed to swing downward with a locking point q with 18 as a fulcrum. A rubber seal 25 is mounted across the button mounting portion of the cover case 5 and the push button 7 to prevent dust or liquid from entering the switch.

  The switching mechanism 6 is configured as described above, and when the push button 7 is pushed and an external force does not act normally, as shown in FIGS. 1 and 3A, the tension of the coil spring 21 installed with the initial tension The locking point q of the operating piece 19, the spring receiving point r of the operating piece 17, and the spring receiving point s of the movable piece 17 are positioned on a straight line. At this time, the spring receiving point r of the operating piece 19 is positioned above an imaginary line L passing through the locking point p of the movable piece 17 and the spring receiving point s of the movable piece 17, and the movable piece 17 is locked. Oscillating upward with the point p as a fulcrum, the movable contact 22 of the movable piece 17 is pressed against the fixed contact 23 of the fixed piece 14 and the terminal 2 and the terminal 3 are in a conductive state.

  When the push button 7 is pushed and displaced by an external force from the state shown in FIG. 3A, the operating piece 19 is swung downward about the locking point q, and the coil spring 21 is extended and the spring of the movable piece 17 is extended. It is swung downward about the receiving point s. As soon as the spring receiving point r of the operating piece 19 passes through a virtual line (dead point) L passing through the locking point p of the movable piece 17 and the spring receiving point s, the tension of the coil spring 21 causes the moving piece 17 to move to the movable piece 17. The applied swinging action is reversed from upward to downward, the movable piece 17 is swung downward instantaneously, the movable contact 22 is brought into contact with the fixed contact 24 of the fixed piece, and contact switching is performed instantaneously.

  When the push-in operation of the push button 7 is released, the operating piece 19 is in a free state, and the tension q of the operating piece 19, the spring receiving point r of the operating piece 19, and the operating piece 17 are stabilized by the tension of the coil spring 21. When the spring receiving point r of the operating piece 19 passes above the dead point, the movable piece 17 is again subjected to the upward swinging action, and the original posture shown in FIG. Return to, and contact switching is performed.

  The above configuration is basically the same as that of a micro switch having a specification that performs a snap operation using a coil spring, but in this embodiment, the movable piece 17 is modified as follows.

  That is, in this embodiment, the movable piece 17 is formed by punching and pressing a leaf spring made of phosphor bronze, beryllium copper, or the like. As shown in FIGS. A portion between the base end of the movable piece 17 locked to the piece 13a and the spring connecting hole 20 is bent in a mountain shape. This bending portion 17a is a displacement allowing portion E that is elastically bent to displace the movable contact 22 provided at the free end portion in the longitudinal direction of the movable piece.

  According to this configuration, when the movable piece 17 snaps up and down to switch the contact, the displacement allowable portion E of the movable piece 17 slightly expands and contracts due to the change in the tension of the coil spring 21. As shown by an arrow A in FIG. 5, the free end side is displaced in the longitudinal direction of the movable piece, and relative sliding (wiping operation) of the movable contact 22 with respect to the fixed contacts 23 and 24 on the other side is performed. Fusion is avoided in advance.

  In this way, when the movable piece 17 snaps to perform contact switching, the movable piece 17 expands and contracts due to a change in tension of the coil spring 21, and the movable contact 22 at the free end thereof is relative to the fixed contacts 23 and 24. Since the wiping operation is performed by sliding, for example, when switching between contacts through which a high current flows, even if a phenomenon occurs in which melting occurs between the contacts and causes light welding, the above wiping operation between the contacts Therefore, the progress of welding can be avoided in advance, and it is not necessary to use an expensive contact material as in the prior art, and the cost can be reduced. In addition, the self-cleaning effect of purifying the contact surface can be achieved by the wiping operation.

(Other examples)
(1) As shown in FIG. 6, the movable piece 17 is made of a thick plate material made of brass, and the receiving member 13 is made of a leaf spring material to lock the base end of the movable piece 17. The piece 13a is an upward cantilevered displacement-allowing portion E, and the receiving piece 13a is elastically deformed back and forth by a change in the spring force applied to the movable piece 17 by the coil spring 21, whereby the entire movable piece 17 is made. It can be displaced in the longitudinal direction so that relative sliding is performed between the contacts, and an equivalent function can be exhibited.

  (2) The displacement permitting portion E formed by bending the spring plate material may be connected to the base end side of the movable piece 17 made of a thick plate material made of brass by caulking or spot welding or the like to exert an equivalent function. In this case, by changing the elastic deformation characteristics of the displacement allowable portion E by changing the plate thickness and bending state of the spring plate material, a switching mechanism with different wiping operation characteristics is formed, and micro-currents with different energization amounts are formed. Can correspond to a switch.

  (3) In each of the embodiments described above, the present invention is applied to a micro switch. However, the present invention is not limited to a micro switch, but can be applied to a limit switch, a push button switch, and other switches.

  The present invention is useful as various switches such as a micro switch, a limit switch, and a push button switch.

It is a vertical front view of a microswitch. It is a perspective view which shows the inside of a microswitch. It is the side view to which the principal part of the switching mechanism was expanded. It is a top view of a movable piece. It is a vertical front view of a movable piece. It is a vertical front view of the microswitch of another Example.

Explanation of symbols

2, 3, 4 Terminal 6 Switching mechanism 7 Actuator (push button)
DESCRIPTION OF SYMBOLS 13 Receiving member 14,15 Fixed piece 17 Movable piece 17a Bending part 19 Actuating piece 21 Coil spring 22 Movable contact 23, 24 Fixed contact E Displacement allowance part

Claims (3)

In the switch configured to snap the movable piece of the switching mechanism by the displacement operation of the actuator and switch the conduction between the terminals,
The switching mechanism, and the movable piece having a movable contact on the free end portion, and a receiving member for swingably supporting the base end of the movable piece with coupled to the terminal, while being connected to the other terminal A fixed piece having a fixed contact facing the free end of the movable piece, an operating piece supported by the receiving member so as to be swingable and operated to swing by the actuator, the working piece and the movable piece; With a coil spring installed over
Comprising a displacement permitting portion for allowing the free end of the movable piece is displaced movable piece longitudinally by the tension change of the coil spring,
The connection point of the coil spring to the movable piece is between the displacement allowing portion and the movable contact . The switch according to claim 1 , wherein
A switch in which the entire movable piece is formed of a spring plate material, a bent portion is formed between a base end of the movable piece and a connection point of the coil spring to the movable piece, and the bent portion is used as the displacement allowing portion. The switch according to claim 1, wherein
A switch provided with a receiving piece for locking the base end of the movable piece on the receiving member, and configured so that the receiving piece can be elastically deformed to serve as the displacement allowing portion.

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