JP2000215751A - Micro-switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To be friendly to a human body and environment, facilitate its assembling work, and reduce the cost by forming a compression spring member applying a snap action to a movable contact piece constituting a contact opening/ closing mechanism of phosphor bronze alloy or stainless steel treated by cold rolling. SOLUTION: A compression spring member 9 is composed of phosphor bronze alloy and a projection part 9c is formed in its base end part 9b side. The compression spring member is formed by bending a projection part 9d in the rear side of the trapezoidal top part so as to improve spring performance in mechanism and disperse a local compulsory stress energized by the spring member 9, thereby attaining the long life. Stainless steel treated by cold rolling can be also used as a material for the compression spring member 9. The compression spring member 9 is erected across a common fixing terminal piece 2 and a movable contact piece 8 so that the both ends 9a, 9b are detachable locked, and the both ends 10a, 10b of the receiver member 10 are erected across the common fixing terminal piece 2 and the movable contact piece 8 so as to be detachably locked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro switch having a snap action function.

[0002]

2. Description of the Related Art Conventionally, as a micro switch of this type,
For example, as shown in FIG. 5, the common fixed terminal piece 2, the normally open fixed terminal piece 3, and the normally closed fixed terminal piece 4 are fixed to the switch case 1, and are fixed to the distal ends of the fixed terminal pieces 3, 4. The movable contact 7 which comes into contact with and separates from the fixed contacts 5 and 6 is fixed to the tip 8a of the movable contact piece 8, and the one end 9a of the compression spring member 9 is locked to the tip of the movable contact piece 8;
A base end portion 9b of the compression spring member 9 is locked in a locking groove 2b formed in a bent portion 2a of the common fixed terminal piece 2, and a distal end portion 10a is rotatable on the common fixed terminal piece 2. The base end portion 10b of the locked receiving member 10 is locked to the base end portion 8b of the movable contact piece 8, and the movable contact piece 8 is pressed by the operating body 11, so that the movable contact piece 8 is snapped. A device that performs an opening and closing operation is known.

In the above construction, when the operating body 11 is pressed, the movable contact piece 8 is pushed in a predetermined amount via the base end portion 10b of the receiving member 10 against the spring force of the compression spring member 9, and the compression spring With the instantaneous operation of the snap action in response to the spring reaction force of the member 9, the movable contact 7 reverses and the contact state can be switched from the normally closed fixed contact 6 to the normally open fixed contact 5.

Conventionally, the compression spring member 9 has
It is made of beryllium copper (Be-Cu) alloy because it has good spring properties and operability and has a long life. Generally, a beryllium alloy is a ternary alloy of copper Cu-
A beryllium-be-cobalt-co alloy, with a large amount of Be, has a high strength, while a small amount has good electrical and thermal conductivity, and is extremely ductile and has good workability in an annealed state. Precipitation treatment (so-called quenching) increases the strength and hardness by age hardening. Addition of Co suppresses crystal growth and enhances uniform heat treatment performance to conduct electricity and heat. As well as being able to enhance the properties, it has a variety of properties and advantages such as being excellent in corrosion resistance and abrasion resistance by forming a surface film of beryllium oxide BeO, and having little dimensional change and being strong against fatigue and inexpensive. At present, it is applied not only to electrical components such as spring members, contacts and electrodes, but also to special applications, and its application range is extremely wide.

[0005]

However, as beryllium-copper alloys having many advantages are widely used in industry, beryllium-be or salts thereof contained in the beryllium-copper alloys adversely affect the tracheal system, especially the lungs. give,
Not only manufacturing factories, but also environmental issues are not only social issues, but their use is being regulated, for example, in Europe and the United States.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a microswitch which is friendly to the human body and the environment, inexpensive, and easy to assemble while ensuring various properties of electric components as much as possible. .

[0007]

According to a first aspect of the present invention, there is provided a microswitch, wherein a compression spring member for applying a snap action to a movable contact piece constituting a contact opening / closing mechanism is formed of a phosphor bronze alloy. I do. Claim 2
In the microswitch according to the invention, the compression spring member for providing a snap action to the movable contact piece constituting the contact opening / closing mechanism is formed of cold-rolled stainless steel. According to a third aspect of the present invention, there is provided a microswitch comprising the above-mentioned phosphor bronze alloy containing copper (C
u) contains 0.03 to 0.35% by weight of phosphorus (P) and 7.0 to 9.0% by weight of tin (Sn) and is 0.05% or less of lead (Pb), 0.10% by weight. Weight percent iron (F
e) and zinc (Zn) of 0.20% by weight or less are added, and this is subjected to a low-temperature annealing treatment.

According to a fourth aspect of the present invention, there is provided the microswitch, wherein the compression spring member for applying a snap action to the movable contact piece constituting the contact opening / closing mechanism is formed by bending a protruding portion at a substantially trapezoidal top. Features. According to a fifth aspect of the present invention, there is provided the microswitch, wherein a compression spring member for applying a snap action to the movable contact piece constituting the contact opening / closing mechanism is formed by bending a protruding portion toward the rear side of the substantially trapezoidal top. A stopper structure is provided in which the protruding portion is brought into contact with the inner end of the common fixed terminal piece to which the compression spring member is detachably engaged.

[0009]

According to the first and second aspects of the present invention, since the compression spring member is formed of a phosphor bronze alloy or stainless steel, it is possible to provide an inexpensive microswitch that is friendly to the human body and the environment. According to the third aspect of the present invention, a high-performance spring member having extremely high strength and hardness and excellent spring properties can be obtained.

According to the fourth aspect of the present invention, the protruding portion is bent at the top of the compression spring member, so that the spring property is mechanically enhanced, and the compression spring member is locally biased by the spring member. The stress can be dispersed to achieve a longer life. According to the fifth aspect of the present invention, a contact portion is opened and closed by forming a projecting portion on the top of the compression spring member so as to abut the projecting portion on the inner end of the common fixed terminal piece. Work efficiency can be improved by avoiding disassembly during assembly of the mechanism as much as possible.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of a microswitch according to the present invention. 5, the same or corresponding parts as those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, the difference from the conventional micro switch shown in FIG. 5 lies in the material and the shape of the compression spring member 9. That is, the compression spring member 9 is characterized in that the material is made of a phosphor bronze alloy instead of the conventional beryllium copper alloy, and a protruding portion 9c is formed on the base end 9b side.

Phosphor bronze alloy is made of copper (Cu) and tin (Sn)
A small amount of phosphorus (P) is added to tin bronze, which is an alloy of the above, to enhance its various properties. For example, a phosphor bronze alloy containing 0.03 to 0.35% by weight of phosphorus (P) and 3.0 to 9.0% by weight of tin (Sn) has excellent ductility, corrosion resistance, and fatigue resistance. Further, 0.03 to 0.35% by weight of phosphorus (P) and 5.5 to 5% of tin (Sn) are used.
Phosphor bronze alloys containing 9.0% by weight have extremely high strength and hardness and are excellent in spring properties.

Therefore, the compression spring member 9 is made of a phosphor bronze alloy containing 0.03 to 0.35% by weight of phosphorus (P) and 5.5 to 9.0% by weight of tin (Sn). Is recommended. Further, phosphorus (P) is set to 0.03 to 0.
It is preferable that a phosphor bronze alloy containing 35% by weight and 7.0 to 9.0% by weight of tin (Sn) be used as the compression spring member 9 in order to further enhance the above-mentioned properties. In that case, the phosphor bronze alloy containing 0.03 to 0.35% by weight of phosphorus (P) and 7.0 to 9.0% by weight of tin (Sn) is, for example, a trace amount of lead of 0.05% by weight or less. (Pb), 0.10% by weight or less of iron (Fe) and 0.1% by weight.
By adding a trace amount of zinc (Zn) of 20% by weight or less and subjecting this to low-temperature annealing, a high-performance spring member can be obtained. By using such a phosphor bronze alloy as a constituent material of the compression spring member 9, it is possible to provide an inexpensive microswitch that is friendly to the human body and the environment.

However, in general, there is a problem that the phosphor bronze alloy is inferior in the spring property and the life as compared with the conventionally used beryllium alloy. As a means for improving this, for example, it is recommended that the shape of the compression spring member 9 be devised. That is, the conventional compression spring member 9 is bent substantially in a trapezoidal shape as shown by a virtual line and a solid line in FIG. By bending the protruding portion 9d on the rear side of the top portion 9c, the spring property is mechanically enhanced, and a locally unreasonable stress applied to the spring member 9 is dispersed to extend the life. Can be achieved.

As shown in FIG. 3, the compression spring member 9 is provided between the common fixed terminal piece 2 and the movable contact piece 8 so that both ends 9a and 9b are detachably locked.
In the case where both end portions 10a and 10b of the receiving member 10 are bridged between the common fixed terminal piece 2 and the movable contact piece 8 and detachably locked, and the contact opening / closing mechanism 12 is assembled and incorporated into the switch case 1, In this case, when an excessive force is applied to the movable contact piece 8 in the direction of arrow a, the assembly structure of the contact opening / closing mechanism 12 is disassembled. As described above, the rising piece 9e of the projecting portion 9d of the compression spring member 9 constitutes the stopper structure 13 in which the rising piece 9e comes into contact with the inner end 2c of the common fixed terminal piece 2.
Disassembly of the contact opening / closing mechanism 12 can be avoided as much as possible.

In the above embodiment, the case where a phosphor bronze alloy is used as the material of the compression spring member 9 has been described. For example, Fe containing 18 to 18% by weight of chromium Cr and 7 to 8% by weight of nickel Ni is used. -Ni-C
Austenitic stainless steel, which is an r-alloy, can be used as a spring-resistant stainless steel manufactured by cold rolling. Although the protrusion 9d formed on the compression spring member 9 is bent at the rear side of the substantially trapezoidal top 9c, the trapezoidal top 9c is formed.
Even if it is bent at the center portion or the front portion side or almost the entire area, the mechanical resilience can be enhanced, and the local stress can be dispersed to extend the life.

[0017]

As described above, claims 1 and 2
According to the invention, since the compression spring member is formed of a phosphor bronze alloy or stainless steel, it is friendly to the human body and the environment,
In addition, an inexpensive switch can be provided. Claim 3
According to the invention, a high-performance spring member having extremely high strength and hardness and excellent in spring properties can be obtained.

According to the fourth aspect of the present invention, the protruding portion is bent at the top of the compression spring member, so that the spring property is mechanically enhanced and the spring member is locally biased. The stress can be dispersed to achieve a longer life. According to the fifth aspect of the present invention, a contact portion is opened and closed by forming a projecting portion on the top of the compression spring member so as to abut the projecting portion on the inner end of the common fixed terminal piece. Work efficiency can be improved by avoiding disassembly during assembly of the mechanism as much as possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a microswitch according to the present invention.

FIG. 2 is a side view showing an example of a compression spring member incorporated in the switch.

FIG. 3 is a side view showing a main part of a contact opening / closing mechanism incorporated in the switch.

FIG. 4 is a side view showing an operation at the time of assembling the contact opening / closing mechanism.

FIG. 5 is a cross-sectional view illustrating an example of a conventional microswitch.

[Explanation of symbols]

 2 Common fixed terminal piece 2c Inner end 8 Movable contact piece 9 Compression spring member 9d Projection 12 Contact opening / closing mechanism 13 Stopper structure

Claims (5)

[Claims] 1. A microswitch, wherein a compression spring member for providing a snap action to a movable contact piece constituting a contact opening / closing mechanism is formed of a phosphor bronze alloy. 2. A microswitch, wherein a compression spring member for providing a snap action to a movable contact piece constituting a contact opening / closing mechanism is formed of cold-rolled stainless steel. 3. The phosphor bronze alloy contains copper (C) as a main component.
u) contains 0.03 to 0.35% by weight of phosphorus (P) and 7.0 to 9.0% by weight of tin (Sn) and is 0.05% or less of lead (Pb), 0.10% by weight. Weight percent iron (F
The microswitch according to claim 1, wherein e) and zinc (Zn) of 0.20% by weight or less are added, and this is subjected to a low-temperature annealing treatment. 4. A compression spring member for imparting a snap action to a movable contact piece constituting a contact opening / closing mechanism is formed by bending a projecting portion on a substantially trapezoidal top. The microswitch according to any one of the above. 5. A compression spring member for imparting a snap action to a movable contact piece constituting a contact opening / closing mechanism is formed by bending a protruding portion at a rear side of a substantially trapezoidal top, and attaching and detaching the compression spring member. The microswitch according to any one of claims 1 to 4, wherein the microswitch has a stopper structure in which the protruding portion is brought into contact with an inner end of the common fixed terminal piece which is locked as possible.