JP3780914B2 - Water resistant micro switch device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention has a minute contact gap formed between a fixed contact and a movable contact, and a snap action mechanism, and a contact mechanism that opens and closes with a specified movement and a specified force is covered with a switch case, On the other hand, it relates to a micro switch device in which a push button operated by the movement of an external operation body is projected from the switch case to the outside, and in particular, an operation that applies an operating force to the push button by contacting the tip of the push button. The present invention relates to a water-resistant microswitch having a water-resistant structure in which a body faces a liquid.
[0002]
[Prior art]
A conventional microswitch device will be described with reference to FIG.
The micro switch M includes a box-shaped switch case 50, a fixed contact, a movable contact disposed opposite to the fixed contact, a movable piece made of a spring material having a snap action function for switching between the fixed contact and the movable contact, A push button 51 is provided as an actuator for operating the movable piece by an external force.
The push button protrudes outward from the switch case 50 because it receives an external force by an operating body described later.
Reference numeral 52 denotes a device for operating the push button 51 of the micro switch M or an operation body on the apparatus side. The operation body 52 is housed and disposed in an operation body case 53.
The operating body 52 in this example is a rotating body that can be rotated by a shaft 52A, and a cam 52B is formed on the outer periphery thereof.
The microswitch M is screwed to one of the mounting members 54 and the other is screwed to the operating body case 53. At this time, the push button 51 of the microswitch M is drilled in the operating body case 53. The push button guide hole 53A is supported so as to protrude into the operation body case 53.
At this time, the tip 51 </ b> A of the push button 51 is disposed inside the operation body case 53 and faces the cam 52 </ b> B of the operation body 52.
[0003]
According to the microswitch device configured as described above, when the operating body 52 is rotationally displaced, the cam 52B rotates, the tip 51A of the push button 51 comes into contact with the cam 52B, and the push button 51 moves to the left in FIG. The microswitch M switches electrical contacts (opens / closes an electrical circuit or switches an electrical circuit).
More specifically, referring to FIG. 3, the tip 51A of the push button 51 is arranged facing the escape portion 52C of the operating body 52 in the state shown in the figure, and the push button 51 is at the rightmost position. In this first state, the movable contact is brought into contact with the fixed contact by the movable piece, and both the contacts maintain the connection state.
When the operating body 52 is rotated clockwise from the first state, the tip 51A of the push button 51 comes into contact with the cam 52B from the escape portion 52C. According to this, the push button 51 is moved to the left in FIG. The second state is maintained by displacing to the second position.
In this second state, the movable contact is separated from the fixed contact by the movable piece, and both the contacts are held open.
[0004]
[Problems to be solved by the invention]
According to such a conventional microswitch device, fluid such as liquid, a mixture of liquid and gas, or vapor flows in the operation body case 53, and the operation body 52 and the push button 51 are connected to the fluid in the operation body case 53. When placed inside, the following problems occur.
In other words, the fluid in the operating body case 53 is provided with the first gap S1 and the switch formed between the push button guide hole 53A opened in the operating body case 53 and the outer periphery of the push button 51. There is a risk of entering the micro switch M through the second gap S2 formed between the push button guide hole 50A formed in the case 50 and the outer periphery of the push button 51. (The first gap S1 and the second gap S2 are gaps necessary to allow the push button 51 to move laterally.)
According to the above, the contact portion between the fixed contact and the movable contact disposed in the switch case 50 of the micro switch M is corroded, and there is a possibility that the switch function may be hindered particularly when used for a long period of time.
[0005]
FIG. 4 shows another microswitch device.
(Note that the same structural parts as those in FIG.
That is, an annular seal ring 55 formed of a rubber material or a synthetic resin material is pressed in the first gap S1 formed between the outer periphery of the push button 51 and the push button guide hole 53A of the operating body case 53. Be placed.
When the seal ring 55 is disposed in a pressed state in the first gap S1, the fluid in the operation body case 53 is prevented from flowing outward from the first gap S1 by the seal ring 55. Thus, the above-mentioned problem that the fluid in the operating body case 53 enters the micro switch case 50 is solved.
Here, when attention is paid to the operation of the push button 51 of the micro switch M, the left movement of the push button 51 is mechanically pressed by the cam 52B of the operating body 52 and moved.
On the other hand, the push button 51 is moved to the right by the spring force of a spring (not shown) disposed in the switch case 50.
According to the above, the pressing force to the outer periphery of the push button 51 by the seal ring 55 needs to be set and held always weaker than the spring force of the spring, and the pressing force of the seal ring 55 is kept constant over a long period of time. In order to hold it, it is necessary to accurately manage the dimensional accuracy in the seal portion.
If the seal ring 55 is made of a rubber material and the micro switch M is left in an inoperative state for a long time, the seal ring and the outer periphery of the push button 51 may be loosened. The smooth operation of the button 51 is hindered.
[0006]
A high-temperature fluid such as a high-temperature liquid, a high-temperature gas, or high-temperature steam flows through the operation body case 53, and the operation body 52 and the push button 51 are disposed in the high-temperature fluid of the operation body case 53. In this case, the push button 51 is heated by the fluid temperature in the operation body case 53 and greatly increases in temperature, and the heat of the push button 51 acts on the movable piece, the fixed contact, the movable contact, the terminal and the like constituting the micro switch M. In addition, the switch function may be hindered.
[0007]
Here, in order to solve the problem, a micro switch M as shown in FIG. 5 is used. According to this, the length of the push button 51 is made sufficiently long, and the distance between the operating body case 53 and the micro switch M is increased. Those with a large separation are used.
By using such a micro switch M, even if the tip 51A of the push button 51 is heated by the high-temperature fluid in the operating body case 53, the temperature of the push button 51 decreases toward the rear end of the push button 51. Inhibition of the switch function by the fluid can be suppressed.
However, according to the microswitch, a new long pushbutton 51 is required, and a commercially available general-purpose microswitch cannot be used. Further, the microswitch M protrudes greatly to the side. This causes a malfunction.
[0008]
The microswitch device according to the present invention has been made in view of the above problems, and its purpose is to provide a liquid, a mixture of liquid and gas, a fluid such as steam, and a liquid, mixture, and gas in a high temperature state. An object of the present invention is to provide a water-resistant microswitch device suitable for use in high-temperature fluid such as steam.
[0009]
[Means for solving the problems]
In order to achieve the above object, the microswitch device according to the present invention includes a fixed contact, a movable contact facing the fixed contact, a movable piece for switching the contact, and a push button for operating the movable piece in response to an external force. A microswitch comprising:
An operating body that is disposed in the operating body case and applies a mechanical external force toward the push button; a detection rod that detects the movement of the operating body at its tip and transmits it to the push button through the rear end; With
It is the first that the detection rod is movably supported by the central portion of the flexible member whose outer peripheral portion is sandwiched between the opposing surfaces of the one-side housing and the other-side housing that movably accommodates the detection rod. It is characterized by.
[0010]
According to the present invention, in addition to the first feature, the first chamber facing the front end surface side of the flexible member is recessed in the one side housing, and the rear end surface side of the flexible member is disposed on the other side housing. The second feature is that the second chamber that faces is recessed.
[0011]
Furthermore, in addition to the first feature, the third feature of the present invention is that the one-side casing is integrally formed with an operating body case.
[0012]
[Action]
According to the first feature of the water-resistant microswitch device of the present invention, the fluid in the operating body case that goes from the inside of the operating body case to the inside of the microswitch through the gap between the outer periphery of the detection rod and the push button guide hole is Since it is blocked by the flexible member attached to the detection rod, components placed in the switch case of the microswitch are not corroded by the fluid, and a stable switch function can be maintained for a long period of time.
In addition, when the operating body is arranged facing the high temperature fluid, the heat of the high temperature fluid acts on the detection rod to heat the detection rod, but the detection rod drops in temperature from the front end to the rear end in the longitudinal direction. Therefore, the high temperature of the fluid does not directly act on the push button, and the switch function is prevented from being lowered by the high temperature fluid.
Moreover, since the detection rod is centered and supported by the flexible film, the detection rod can be moved smoothly.
[0013]
According to the second feature of the present invention, since the first chamber and the second chamber as the space are formed in the flexible film, the heat conduction from the front end to the rear end of the detection rod is Since the cooling is effectively performed by the space portions of the first chamber and the second chamber, the influence of the heat acting on the microswitch from the detection rod can be further effectively reduced.
[0014]
Further, according to the third feature of the present invention, the housing on one side is formed integrally with the operating body case, and this can be formed simultaneously with the injection molding of the operating body case.
According to this, the protrusion of the micro switch to the side can be suppressed and the housing on one side as a part can be eliminated, and the micro switch device can be miniaturized and effective in reducing the manufacturing cost.
[0015]
【Example】
An embodiment of a water-resistant microswitch device according to the present invention will be described below with reference to FIG.
The micro switch M includes a box-shaped switch case 1, a fixed contact, a movable contact opposed to the fixed contact, a movable piece having a snap action function for switching between the fixed contact and the movable contact, and a movable piece by an external force. And a push button 2 as an actuator for operating.
The push button 2 is movably disposed in a push button guide hole 1A formed in the switch case 1, and the tip 2A of the push button 2 is disposed so as to protrude from the switch case 1. In this example, the push button guide It is arranged to protrude rightward from the right end of the cylindrical portion 1B.
Since the microswitch M itself is a general-purpose microswitch that is generally used conventionally, internal structures such as a movable contact and a fixed contact are omitted.
[0016]
Reference numeral 3 denotes a device for operating the push button 2 of the micro switch M or an operation body on the apparatus side. The operation body 3 is accommodated in the operation body case 4.
The operating body 3 in this example is a rotatable rotating body, and the operating body 3 having a disk shape is rotatably supported by the shaft 3A, and includes an escape portion 3B and a cam 3C on an outer peripheral portion thereof. A first push button guide hole 4B is formed through the operation body case 4 from the inner side toward the left mounting surface 4A, and a detection rod, which will be described later, is formed in the first push button guide hole 4B. It is inserted and arranged so that it can move freely.
[0017]
Reference numeral 5 denotes a detection rod extending in a bar shape in the longitudinal direction, and a disc-shaped flange portion 5C extending in a lateral direction is integrally formed at a substantially intermediate portion between the front end 5A and the rear end 5B.
Reference numeral 6 denotes a flexible member made of a diaphragm made of a rubber material. A central portion 6A of the flexible member 6 is fixed on a flange portion 5C of the detection rod 5 via a retainer 7.
That is, the central portion 6A of the flexible member 6 is disposed on the left end of the flange portion 5C, and then the retainer 7 is press-fitted and disposed toward the central portion 6A of the flexible member 6.
The method for fixing the central portion 6A of the flexible member 6 to the detection rod 5 is not limited to the above, and other methods may be used.
As described above, the central portion 6 </ b> A of the flexible member 6 is fixedly disposed at the intermediate portion of the detection rod 5.
[0018]
The detection rod 5 is movably disposed on the casing. Reference numeral 8 denotes a one-side casing. The detection rod 5 is provided with an opposing surface 8A having an annular flat surface at the left end thereof, and is arranged to the right from the opposing surface 8A. A bottomed recessed portion 8B is provided, and a second push button guide hole 8C is formed through the bottom portion toward the right mounting surface 8D.
Reference numeral 9 denotes the other housing, which is provided with a facing surface 9A that forms an annular flat surface at the right end thereof, and a second bottomed recessed portion 9B is provided to the left of the facing surface 9A, and further from the bottom to the left. A third push button guide hole 9 </ b> C is formed to penetrate therethrough.
The distal end side (the right side in FIG. 1) of the detection rod 5 is inserted into the second push button guide hole 8C of the one-side casing 8 and the distal end surface side 6B of the flexible member 6 is the one-side casing 8. On the other hand, the rear end side (the left side in FIG. 1) of the detection rod 5 is inserted into the third push button guide hole 8C of the other housing 9 and is a flexible member. 6 is arranged so that the rear end surface side 6 </ b> C faces the facing surface 9 </ b> A of the other housing 9. In this state, the one-side housing 8 and the other-side housing 9 are screwed and fixed with screws N on the facing surfaces 8A and 9A.
According to the above, the outer peripheral portion 6D forming the annular flat plate of the flexible member 6 is sandwiched between the facing surfaces 8A and 9A of the one-side housing 8 and the other-side housing 9, and the tip end side of the detection rod 5 is the one-side housing. The body 8 is supported in the second push button guide hole 8C, and the tip 5A of the body 8 is arranged to protrude rightward in FIG. 1 from the second push button guide hole 8C.
On the other hand, the rear end side of the detection rod 5 is supported in the third push button guide hole 9C of the other housing 9, and the rear end 5B is arranged to project leftward from the third push button guide hole in FIG. .
Also, according to the above, the first chamber R1 is formed by the front end surface side 6B of the flexible member 6 and the first bottomed recess 8B of the one-side housing 8, and the rear end surface side 6C and the other side of the flexible member 6 are formed. A second chamber R2 is formed by the second bottomed recess 9B of the housing 9.
Therefore, the front end side of the detection rod 5 is disposed in the first chamber R1, and the front end 5A projects rightward of the one-side housing 8 through the second push button guide hole 8C, and the rear end side of the detection rod 5 Is disposed in the second chamber R2, and its rear end 5B protrudes to the left of the other housing 9 through the third push button guide hole 9C.
According to the above, the detection rod 5 is supported between the one-side housing 8 and the other-side housing 9 via the flexible member 6, and the distal end side of the detection rod 5 is the second push button of the one-side housing 8. The detection rod 5 is movably disposed in the guide hole 8C, the rear end side of the detection rod 5 is movably disposed in the third push button guide hole 9C of the other housing 9, and the distal end 5A of the detection rod 5 is on one side. The rear end 5B of the detection rod 5 is disposed so as to protrude leftward from the other housing 9 and is protruded rightward from the housing 8.
[0019]
The right-side mounting surface 8D of the one-side housing 8 including the detection rod 5 is disposed on the left-side mounting surface 4A of the operating body case 4. In this state, the one-side housing 8 is attached to the operating body case 4 with a screw N. Screwed on.
According to the above, the distal end side of the detection rod 5 is disposed in the first push button guide hole 4B of the operation body case 3, and the distal end 5A is disposed to protrude into the operation body case 4, and the escape portion 3B and the cam 3C. It is arrange | positioned facing.
[0020]
Next, the micro switch M is attached to the other housing 9 via the mounting stay 10, and one side of the mounting stay 10 is screwed to the housing via the screw N, and the other of the mounting stay 10 is attached. The side is attached to the microswitch M via a screw N.
According to the above, the rear end 5B of the detection rod 5 that protrudes to the left from the other housing 9 has the tip 2A of the push button 2 of the micro switch M that protrudes to the right from the push button guide tube portion 1B of the switch case 1. The abutment is arranged.
[0021]
The microswitch device constructed as described above performs electrical switching control as follows. The first state is the state shown in FIG. 1, and in this state, the tip 5A of the detection rod 5 is located facing the escape portion 3B of the operating body 3, and the detection rod 5 is the most in FIG. It is in the position moved to the right. According to the above, the tip 2A of the push button 2 of the micro switch M is held in contact with the rear end 5B of the detection rod 5 in such a state, and the push button 2 is held at a position displaced to the rightmost. Thus, for example, the movable contact in the microswitch M is separated from the fixed contact by the movable piece, and the electric circuit is held open.
[0022]
Next, a second state in which the operating body 3 is rotated clockwise in FIG. 1 from the first state will be described.
In this state, the tip 5A of the detection rod 5 is in contact with the cam 3C of the operating body 3, and the detection rod 5 moves to the left according to the height of the cam 3C. According to this, the rear end 5B of the detection rod 5 moves the push button 2 to the left synchronously according to the movement. According to the above, the movable contact in the microswitch M is made to contact the fixed contact by the movable piece. In contact, the electrical circuit is kept closed.
In the above description, the electrical opening / closing control action of the microswitch M by the movement of the push button 2 is the same as the conventional one, and the opening / closing of the electric circuit and the switching of the electric circuit by the movement of the push button 2 are limited by the above. It is not what is done.
[0023]
As described above, according to the microswitch device of the present invention having an electrical opening / closing action, a water-resistant microswitch device suitable for using fluids such as liquid, air-fuel mixture, and steam can be provided.
That is, when the fluid is present in the operating body case 4, the fluid in the operating body case 4 is the outer periphery of the first push button guide hole 8 </ b> C, the second push button guide hole 8 </ b> C, and the distal end side of the detection rod 5. The flexible member 6 attached to the detection rod 5 is directed from the front end 5A to the rear end 5B of the detection rod 5 through the gap formed by the first and second chambers R1. Since the flow of the fluid is blocked, the fluid in the operating body case 4 does not flow into the micro switch M through the gap formed between the push button guide hole 1A and the push button 2.
Therefore, the switch function in the microswitch M can be stably maintained over a long period of time.
[0024]
Focusing on the support of the detection rod 5, the front end side of the detection rod 5 is movably supported by the first push button guide hole 4B and the second push button guide hole 8C, and the rear end side of the detection rod 5 is the third push button. Since the intermediate portion of the detection rod 5 is supported by the guide hole 9C and is supported by the central portion of the flexible member 6 whose outer peripheral portion is sandwiched between the one-side housing 8 and the other-side housing 9. The lateral movement of the detection rod 5 in the longitudinal axis direction is not hindered and can be held well.
[0025]
In addition, a first chamber R1 facing the front end surface side 6B of the flexible member 6 is recessed in the one side housing 8, and a second chamber R2 facing the rear end surface 6C of the flexible member 6 is recessed in the other side housing 9. According to the provision, a water-resistant microswitch device suitable for using a high-temperature fluid such as a high-temperature liquid, a high-temperature mixture, a high-temperature gas, or a high-temperature steam can be provided.
That is, the heat of the high-temperature fluid existing in the operating body case 4 is transmitted from the front end 5A of the detection rod 5 toward the rear end 5B, and in particular, the front end side of the detection rod 5 is cooled by the gas in the first chamber R1. Then, since the rear end side of the detection rod 5 is cooled by the gas in the second chamber R2 and radiated, the temperature transmitted from the rear end 5B of the detection rod 5 toward the front end 2A of the push button 2 is transmitted. Can be effectively reduced.
In addition, when the cooling effect with respect to the detection rod 5 of 1st chamber R1 and 2nd chamber R2 is seen, the cooling effect of 2nd chamber R2 into which air | atmosphere is always introduced is high.
On the other hand, there is an action of heat transfer by the high-temperature fluid in the operating body case 4 from the one side housing 8 toward the other side housing 9, which can be sandwiched between the opposing surfaces 8A and 9A. It is blocked by the outer periphery of the flexible member 6. That is, the flexible member 6 performs a heat insulating action.
[0026]
As described above, the microswitch device according to the present invention can provide a water-resistant microswitch device having both water resistance and heat resistance.
Further, the operating body 3 according to the present embodiment is rotationally supported by the shaft 3A. However, the operating body may be reciprocally interlocked at the time, and at this time, the relief portion and the cam are formed along the direct moving direction. The tip of the detection rod is arranged facing the escape portion and the cam.
[0027]
FIG. 2 shows another embodiment of the water-resistant microswitch device of the present invention.
In addition, about the same structure part as FIG. 1, the description is abbreviate | omitted using the same code | symbol.
In this example, the one-side casing is formed integrally with the operating body case 4 and does not require the one-side casing as a single component.
For example, when the operation body case 4 is injection-molded, the one-side housing portion may be formed integrally.
According to the above, it is not necessary to prepare a special one-side casing, and it is not necessary to attach the one-side casing to the operating body case 4, reducing the number of parts, reducing the number of assembly steps, and screw holes. Since processing such as processing can be reduced, the manufacturing cost of the microswitch device can be greatly reduced.
In addition, if the one-side housing is not specially prepared, the microswitch device can be arranged close to the operation body case 4, and the side of the operation body case including the microswitch device can be made compact. The degree of design freedom has been improved.
[0028]
The operating body case 4 refers to a device or device for storing and arranging the operating body 3, and the operating body 3 applies operating force and operating stroke to the push button 2 of the micro switch M. It is not limited to the disclosed structure.
[0029]
【The invention's effect】
As described above, according to the water-resistant microswitch device according to the present invention, in the switch case, the fixed contact, the movable contact facing it, the movable piece for switching the contact, and the push button for operating the movable piece under external force A microswitch comprising:
An operating body that is disposed in the operating body case and applies a mechanical external force toward the push button; a detection rod that detects the movement of the operating body at its tip and transmits it to the push button through the rear end; With
Since the detection rod is movably supported by the central portion of the flexible member, the outer peripheral portion of which is sandwiched between the opposing surfaces of the one-side housing and the other-side housing that movably accommodates the detection rod. It is possible to completely prevent the fluid, mixture, vapor, etc. flowing in the operating body case where it is stored and placed from entering the micro switch through the push button guide hole that supports the push button. It is possible to provide a water-resistant microswitch device that can maintain a good switching function.
In addition, the temperature of the high-temperature fluid flowing in the operation body case does not directly act on the push button, and the temperature can be lowered by the detection rod and the flexible member. Can be provided.
In addition, the first chamber facing the front end surface side of the flexible member is recessed in the one side housing, and the second chamber facing the rear end surface side of the flexible member is recessed in the other side housing. The rod can be more effectively cooled by the first chamber and the second chamber.
Furthermore, according to the one-side housing being integrally formed with the operating body case, the number of parts and the number of assembly steps can be reduced, and the manufacturing cost can be reduced. Further, the water-resistant microswitch device provided with the operating body case Can be made compact.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a water-resistant microswitch device according to the present invention.
FIG. 2 is a longitudinal sectional view of an essential part showing another embodiment of the water-resistant microswitch device according to the present invention.
FIG. 3 is a longitudinal sectional view of an essential part showing a first example of a conventional microswitch.
FIG. 4 is a longitudinal sectional view of an essential part showing a second example of a conventional microswitch.
FIG. 5 is a longitudinal sectional view of an essential part showing a third example of a conventional microswitch.
[Explanation of symbols]
M Micro switch R1 1st chamber R2 2nd chamber 2 Push button 3 Operating body 4 Operating body case 5 Detection rod 6 Flexible member 8 One side housing 9 Other side housing

Claims (3)

A microswitch M provided with a fixed contact and a movable contact facing the fixed contact, a movable piece for switching the contact, and a push button 2 for operating the movable piece under external force;
An operating body 3 which is arranged in the operating body case and applies a mechanical external force toward the push button;
A detection rod 5 that detects the movement of the operating body at its front end and transmits it to the push button via its rear end;
The detection rod is movably supported by the central portion of the flexible member 6 whose outer peripheral portion is sandwiched between opposing surfaces of the one-side housing 8 and the other-side housing 9 that house the detection rod 5 movably. A water-resistant microswitch device characterized by that. A first chamber R1 facing the front end surface 6B side of the flexible member 6 is recessed in the one side housing, and a second chamber R2 facing the rear end surface 6C side of the flexible member 6 is recessed in the other side housing 9. The water-resistant microswitch device according to claim 1, wherein The water-resistant microswitch device according to claim 1, wherein the one-side casing is integrally formed with the operating body case.

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