JPH0950730A - Push button switch - Google Patents

Abstract

(57) [Summary] [Purpose] Always reliably perform emergency stop of the load by pressing the push button. [Structure] The pushing force is transmitted to the push rod 5 when the push button 2 is pushed, and the pushing force of the push rod 5 which has received the spring force exceeds the predetermined value. It is assumed that an engaging structure is provided which is held occasionally at the end of the push rod 5 after the movement and prevents the push rod 5 from returning to the pre-pressing position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push button switch whose contacts are opened and closed by pressing a push button, and more particularly to a push button switch used for emergency stop of a load.

[0002]

2. Description of the Related Art As a push button switch used for an emergency stop of a load, one having a structure shown in, for example, FIG. 6 is conventionally known (see Japanese Patent Application No. 5-108621). With this structure, the push button switch is fixed to the operation panel 12 and is formed by a cylindrical frame 1, a push button 2 arranged at the front end of the frame 1, and a push button 2 which is pushed downward. The push rod 7 that is pushed down to turn the contact of the switch unit 10 off or on is configured as a main component. The central portion of the push button 2 is formed in a hollow cylindrical shape, and the two projections 16a formed on the upper end portion of the push rod 7 are fitted into the two concave portions 18a formed on the inner wall surface of the hollow cylinder, respectively, and then the cap is formed. 19 is inserted and the push rod 7 is tightened with a screw on the outer peripheral surface of the tip end of the cap 19, whereby the push button 2 and the push rod 7 are firmly integrated, and the relative position around the shaft of the push button 2 and the push rod 7 is predetermined. Held in position. Reference numeral 20 denotes a return spring, which is a position before the push button 2 is pressed, that is, the contact portion 17a of the lock device 17 fixed to the inside of the frame 1.
And the protrusion 13b of the push rod 7 come in contact with each other.

In the push button switch constructed as described above,
When the push rod 7 is pushed down by pushing the push button 2, the contact of the switch unit 10 is turned off or turned on. However, the protrusion 13 formed on the push rod 7 at a position immediately before the push rod 7 is completely pushed down.
d is deformed by pressing the taper surface on the lower surface side by the taper surface on the upper surface side of the protrusion (not shown) on the lock portion 17 side, and by further pressing the push rod 7, the protrusion 13d is locked by the lock portion 1.
7, the push rod 7 is locked at a position where both the protrusions are engaged, and the contact of the switch portion 10 is held in the off state or the on state.

The return of the push button switch to the state before the push operation is performed by rotating the push button 2 around the axis and disengaging the projection 13d from the projection of the lock portion 17.

[0005]

In the push button switch constructed as described above, the contact of the switch section is turned off or turned on before the push bar reaches the end point of movement by the push operation of the push button, and the load is stopped. Is displayed on the panel, etc., so it is possible to accidentally let go of the pressing operation before the push bar is pressed all the way down, and the push bar returns to its original position without being locked at the end point of movement and the load is restarted. There was a possible problem.

An object of the present invention is to provide a structure of a push button switch which can always reliably perform an emergency stop of load operation by pushing a push button.

[0007]

In order to solve the above problems, in the present invention, a frame made of a cylindrical body attached to an operation panel, a push button arranged at the front end of the frame, and a push button According to a first aspect of the present invention, there is provided a push button switch including a push rod that slides in a frame to open and close a contact of a switch portion by an operation, and pressure transmission to the push rod when the push button is pushed through a spring. The push rod is moved by a spring force when the spring force exceeds a predetermined value, and after the movement, the push rod is locked at its moving end position to the pre-pressing position. The engaging structure is provided to prevent the return of the.

In this case, in the engaging structure, as described in claim 2, when the push rod moves, the protrusion formed on the inner side of the frame made of the cylindrical body is deformable around the push rod. It is preferable to adopt a structure in which the convex portion formed on the surface is overridden. Further, the push button switch having the above-mentioned engagement structure is provided with an engagement portion between the push button and the push rod, which allows the relative movement in the axial direction of the push button and the push rod and disables the relative movement in the circumferential direction. A coil-shaped return spring for returning the push button to the position before the pressing operation after the pressing force on the push button disappears is provided coaxially with the frame between the frame and the push button so that one end of the coil is in the frame and the other end is in the other end. Is fixed to the push button, and by rotating the push button around the axis,
It is preferable to use a switch that releases the engagement between the push rod and the frame after the push button is moved by the pressing operation and returns the push button to the position before the pressing operation.

[0009]

As described above, the pressure transmission to the push rod when the push button is pressed is performed through the spring, and when the movement of the push rod which receives the spring force exceeds the predetermined value. If it is provided with an engagement structure that locks the push rod at its moving end position after movement and prevents it from returning to the pre-pressing position, the push rod that has started moving will accumulate until then. It moves all at once to the end point of movement with the spring force
Further, since the contact is locked at the movement end point, the contact that is turned off (or turned on) in the middle of the movement remains in the off (or on) state as it is, and the load that has once been emergency stopped will not be restarted.

The movement of the push rod is
If the protrusion formed on the inner surface of the frame made of a tubular body is overcome by the protrusion formed on the peripheral surface of the push rod made of a deformable material, the push rod can be moved in only one direction. Since the mating is performed, there is an advantage that the engaging structure is simple and the push button switch is not complicated.

Further, as a structure for releasing the engagement between the push rod and the frame after the movement, an engaging portion is provided between the push button and the push rod for permitting relative movement of both in the axial direction and prohibiting relative movement in the circumferential direction. A coil-shaped return spring is provided coaxially with the frame between the frame and the push button to return the push button to the position before the pressing operation after the pressing force on the push button disappears. The end of the push button is fixed to the push button, and the push button is rotated about its axis to release the engagement between the push rod and the frame after the push button is moved. A twisting force is applied to the coiled return spring that is already in the stored state at the time of rotation, the push button is rotated to release the engagement, and then the hand is released from the push button. Depending on the turning force, the push button To return to the position before the pressing operation.

[0012]

1 shows an embodiment of a push button switch structure constructed according to the present invention. The push button 2 arranged at the front end portion of the frame 1 formed in a tubular body has a hollow cylindrical center portion, and has a convex portion formed at the lower end portion of the inner peripheral surface of the cylinder and an outer peripheral surface of the rotary cylinder 4. The formed recess is fitted into the press-fitted state, and the push button 2 and the rotary cylinder 4 are firmly integrated.
Therefore, the rotary cylinder 4 can be regarded as a part of the push button 2. The open upper end surface of the rotary cylinder 4 is closed by screwing the cap 3 into the rotary cylinder 4. On the other hand, in the vicinity of the lower end of the inner peripheral surface of the frame 1, a guide cylinder 6 whose structure will be described below is press-fitted and firmly integrated with the frame 1. Therefore, the guide tube 6 can be regarded as a part of the frame 1. As shown in FIG. 4, the guide cylinder 6 has convex portions 61 and concave portions 62 formed alternately on the inner peripheral surface in the circumferential direction. Reference numeral 5 denotes a push rod formed in a cylindrical shape, and convex portions 51 and concave portions 52 are alternately formed on the outer peripheral surface near the lower end in the circumferential direction, and a flange 54 is provided at the lower end, and a notch is provided near the upper end. The portion 53 is formed. These, rotary cylinder 4
Assembly of the push button switch using the push button 2 in which the above is integrated, the frame 1 in which the guide tube 6 is integrated, and the push rod 5 is performed as follows.

First, the push rod 5 is inserted from below the frame 1 so that the convex portion 51 of the outer peripheral surface thereof does not hit the convex portion 61 of the inner peripheral surface of the guide cylinder 6, and then the push rod 5 is slightly rotated around the axis. The convex portion 51 is moved to be placed on the convex portion 61 of the guide cylinder 6. Next, the coil spring 8 for driving the push rod is attached to the push rod 5.
The return spring 20 is placed on the spring seat formed on the outer peripheral surface of the frame 1, and the return spring 20 is mounted on the stepped portion 11 on the inner peripheral surface side of the frame 1. When the return spring 20 is mounted, the lower end of the spring is bent outward in the axial direction of the spring. The part is inserted into the hole of the frame 1. In this state, the upper end surfaces of the coil spring 8 and the return spring 20 are located higher than the upper end surface of the push rod 5, and the bottom surface of the rotary cylinder 4 is placed on these springs. When mounting, the mooring portion formed by bending the upper end of the return spring 20 outward in the axial direction is inserted into the hole on the bottom surface. While compressing the coil spring 8 and the return spring 20 on the bottom surface of the rotary cylinder 4, the notch portion 53 of the push rod 5 is formed on the convex portion 41 formed at the lower end of the inner peripheral surface of the rotary cylinder 4.
Fit in. In the fitted state, the convex portion 41 and the notch portion 53 can move in the axial direction, but cannot move in the circumferential direction. The ring having a V-shaped cross section fitted on the upper surface of the bottom surface of the rotary cylinder 4 is a dustproof seal.

The operation of the push button switch will be described below. When the push button 2 is pressed downward to stop the load in an emergency, the coil spring 8 and the return spring 20 are simultaneously compressed on the bottom surface of the rotary cylinder 4, and the push button switch changes from the state of FIG. 1 to the state of FIG. When the push button 2 is sufficiently pressed and the spring force stored in the coil spring 8 exceeds a predetermined value, the convex portion 51 of the push rod 5 gets over the convex portion 61 of the guide cylinder 6, and the movable contact of the switch 10 is in the process of getting over. Is driven to open and the load stops. The movable amount of the movable contact is 5
Since it is set to be larger than the sliding length in the axial direction of 1, 61, the convex portion 51 passes over the convex portion 61 and slightly overshoots, and then stops by hitting the push rod 5 against a stopper (not shown), When the hand is released, the convex portion 51 is engaged with the convex portion 61 by the restoring force of the return spring 20, and the push button switch stands still in the state of FIG. This series of operations is shown in FIG. In the state where the push rod 5 is pressed as shown in FIGS. 5A and 5B, the contact is closed without the push rod 5 being locked, but as shown in FIG. At the same time when the circuit is opened, the push rod 5 is locked.

To return from the state of FIG. 3 to the state before the push operation of the push button, the push button 2 is rotated around the axis and the convex portions 51, 61 are rotated.
1 is released, and the push rod 5 is returned to the axial position of FIG. 1 by the restoring force of the return spring 20 in the axial direction. Then, when the hand is released from the push button 2, the push restoring force of the return spring 20 pushes the push button 2. Returns to the position before the operation.

[0016]

In the present invention, since the push button switch is based on the above-mentioned construction principle, the following effects can be obtained. According to the first aspect of the present invention, the pressing force is transmitted to the push rod when the push button is pressed, and the push rod moves in response to the spring force so that the spring force exceeds a predetermined value. Occasionally, and after the movement, the push rod is provided with an engaging structure that locks the push rod at its moving end position to prevent the push rod from returning to the pre-pressing position. Since the spring force accumulated up to the point moves all the way to the end point of movement and is locked at the end point of movement, the contact that was turned off (or turned on) in the middle of the movement will remain in the off (or on) state and will be temporarily stopped. The loaded load is not restarted, and the operational reliability of the pushbutton switch is improved.

According to a second aspect of the present invention, in the above-mentioned engagement structure, a convex portion formed inside a frame made of a cylindrical body is formed on a peripheral surface of the push rod made of a deformable material by the movement of the push rod. Since the structure is such that the convex portion is overcome, the engagement is performed only by moving the push rod in one direction, the engaging structure is simplified, and the structure of the push button switch can be made complicated. This made it possible to maintain the reliability of the push button switch.

According to a third aspect of the invention, as a structure for returning the push button switch after the operation to the state before the operation,
An engaging portion is provided between the push button and the push rod to permit relative movement in the axial direction of the push button and the relative movement in the circumferential direction, and to return the push button to the position before the pressing operation after the pressing force on the push button disappears. A coil-shaped return spring is provided coaxially with the frame between the frame and the push button so that one end of the coil is fixed to the frame and the other end is fixed to the push button. Since it was decided to release the engagement between the push rod and frame after movement by operation to return the push button to the position before the pressing operation, rotate the push button to release the engagement, and then from the push button When you let go
By the axial restoring force and the twisting force of the return spring, the push button automatically returns to the position before the pressing operation, and the push button switch can be a simple switch.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a push button switch structure according to the present invention in a push button waiting state for a push button.

2 is a cross-sectional view showing the state of the push button switch shown in FIG. 1 after the push button is pressed and immediately before the start of movement of the push rod.

FIG. 3 is a cross-sectional view showing a state of the push button switch shown in FIG. 1 after completion of operation by pressing the push button.

4A and 4B are views showing an engaging structure for locking the push rod at its moving end, wherein FIG. 4A is a sectional view taken along the line AA of FIG. 3, and FIG. Detailed view of part

5A and 5B are diagrams showing states of the push button switch shown in FIG. 1 at respective stages from before the operation is started to when the operation is completed.
Is a diagram showing a state before the start of operation while waiting for a push button pressing operation,
(B) a diagram showing a state in the middle of operation and immediately before the start of movement of the push rod, and (c) a diagram showing a state of completion of movement in which the push rod completes movement and is locked at the moving end

FIG. 6 is a sectional view showing an example of a conventional push button switch structure.

[Explanation of symbols]

 1 frame 2 push button 3 cap 4 rotating cylinder 41 convex portion 5 push rod 51 convex portion 52 concave portion 53 notch portion 54 flange 6 guide cylinder 61 convex portion 62 concave portion 7 push rod 8 coil spring 10 switch portion 20 return spring

Claims (3)

[Claims] 1. A frame made of a cylindrical body attached to an operation panel, a push button arranged at a front end portion of the frame, and a push operation of the push button sliding the frame to open and close a contact of a switch section. In a push button switch equipped with a push rod that operates, the pressure transmission to the push rod when the push button is pressed is performed via a spring, and the movement of the push rod receiving the spring force causes the spring force to exceed a predetermined value. The push button switch is characterized in that it has an engaging structure for locking the push rod at its moving end position and preventing the return to the pre-pressing position after the movement. 2. The push button switch according to claim 1, wherein
The engagement structure that allows the push rod to move when the spring force exceeds a predetermined value and locks the moved push rod at its moving end position is such that the movement of the push rod is formed inside the frame made of a tubular body. A push button switch, characterized in that the convex portion is formed so that the convex portion formed on the peripheral surface of a push rod made of a deformable material can ride over the convex portion. 3. The push button switch according to claim 2,
An engaging portion is provided between the push button and the push rod to permit relative movement in the axial direction of the push button and the relative movement in the circumferential direction, and to return the push button to the position before the pressing operation after the pressing force on the push button disappears. A coil-shaped return spring is provided coaxially with the frame between the frame and the push button so that one end of the coil is fixed to the frame and the other end is fixed to the push button. A push button switch, characterized in that the push button is returned to the position before the push operation by releasing the engagement between the push rod and the frame after the movement by the operation.