JP3139127B2 - Switch structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type switch structure used for detecting the position of an object.

[0002]

2. Description of the Related Art Conventional switch structures of this type include:
Although those using an inversion mechanism or those using leaf contacts are provided, all of them use a leaf spring, and thus have a disadvantage that the operating positions of the contact portions vary widely.

[0003] Japanese Open Akira as to mitigate such disadvantages 6
There is a switch disclosed in 1-1118916.

This switch is composed of a fixed contact fixed inside a casing, a plunger having a tip protruding outward and slidably mounted on the casing in an axial direction, and orthogonally slidably perpendicular to the plunger. It is composed of a cylindrical movable contact attached, and return means for elastically urging the movable contact so as to press the fixed contact with the fixed contact. As shown, a lead frame 31 is formed by etching,
A semi-annular portion 32 having one contact 35 separated therefrom
9 and 11 are fixed to a support 33 made of synthetic resin by insert molding as shown in FIGS. 9 to 11, and grooves 34 are formed in upper and lower portions of the support 33, and contact points are formed at the bottoms of these grooves 34. 35 is shown.

[0005]

However, in the above-described conventional switch structure, the manufacturing process of the fixed contact 30 includes a process of forming the lead frame 31 by etching and inserting the lead frame 31 into the support base 33. Since this is a two-step process with the molding process for molding, a loss of time and cost has occurred, and since the fixed contact 30 is small, burrs at the joint of the mold cannot be eliminated. And a contact failure due to the molding powder occurred.

In addition, there is a problem that the repeatability, which is a basic characteristic of the switch, is deteriorated due to the influence of the quality of parts (variation in molding conditions, unstable factors due to the movement from etching to molding).

The present invention has been made in view of the above-mentioned problems, and has as its object to reduce the time and cost by reducing the manufacturing process of the fixed contact into one process. Since there is no molding step for insert molding the lead frame on the support base, no burrs are generated on the molded part, no molding powder is generated due to the burrs, and no contact failure is caused by the molding powder. Another object of the present invention is to provide a switch structure that can eliminate the disadvantage that the repeatability, which is a basic characteristic of the switch, is deteriorated.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a fixed contact fixed in a casing and an axially slidable casing having a tip protruding outward. a plunger mounted, a cylindrical movable contact mounted slidably to perpendicular to the plunger, and configured to have a return means for resiliently urging the movable contactor to the fixed contactor side the fixed contact is annular portion of the central portion
And lead pieces respectively formed on both sides of the annular portion.
Flexible substrate, and both ring
A conductor pattern is formed between each end of the
To form a fixed contact, and the plunger
Is movably inserted to form a conductor constituting the fixed contact.
It is characterized in that the pattern and the movable contact are configured to be able to contact and separate from each other.

[0009]

According to this structure, the manufacturing process of the fixed contact becomes a single process, so that time and cost are not lost, and since there is no molding process for insert-molding the lead frame on the support, burrs are formed on the molded portion. In addition, the generation of molding powder due to the burrs is eliminated, the contact failure due to the molding powder is not caused, and the influence of parts quality (variation in molding conditions, unstable element due to etching → movement during molding), etc. Therefore, it is possible to eliminate the disadvantage that the repeatability, which is the basic characteristic of the switch, is deteriorated.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a main part of a switch structure according to the present invention, FIG. 2 is a cross-sectional view of the switch structure in two directions, and FIG.
4 is a perspective view of the fixed contact, FIG. 4 is a plan view of the fixed contact, FIG. 5 is a side view thereof, and FIG. 6 is a rear view thereof.

The switch structure according to the present invention includes an inner case 1, a fixed contact 2, a plunger 3, a movable contact 4, a bearing 5, a return spring 6 serving as a return means, an outer case 7, a packing 8, an end plate 9, and the like. Is composed of
The outer cases 1 and 7 and the bearing 5 constitute a casing.

The inner case 1 is suitably molded integrally with a synthetic resin, is inserted and fixed in an outer case 7, and an end plate 9 is attached to a rear end portion thereof through a packing 8. Through holes 10 and 11 are formed in the packing 8 and the end plate 9, and after assembling the packing 8 and the end plate 9, the resin 12 filled in the rear space of the outer case 7 enters the inside. This is to prevent

As shown in FIGS. 3 to 6, the fixed contact 2 is formed of a flexible substrate having lead pieces 15 and 16 formed on the left and right sides of an annular portion 14 at the center. That is, this flexible substrate is a base (made of polyimide)
17, and the surface of the base 17 has the annular portion 1.
4 from one side (the lower part in FIG. 4)
5. Conductor pattern (copper foil) 18 and annular portion 14 leading to the end of
From the other side (the upper part in FIG. 4)
And a conductive film (made of polyimide) 20 is provided on the surface portion of the base 17.
Numeral 0 denotes inner end portions (grid line portions) 18a and 19a of the conductor patterns 18 and 19 in the annular portion 14 and the lead piece 1
Except for the outer end portions (grid line portions) 18b and 19b of the conductor patterns 18 and 19 at the end portions of the conductor patterns 18 and 19, the conductor patterns 18 and 19 are covered. Gold plating is applied to 19a, 18b and 19b, and the fixed contact 23 is formed. Further, a reinforcing film (made of polyimide) 21 is provided on the back side of the annular portion 14.

The fixed contact 2 constructed as described above is inserted into the inner case 1, and the plunger 3 is movably inserted into the annular portion 14 thereof, and is positioned at the end face of the bearing 5. The lead pieces 15 and 16 are bent at their bases, and the ends thereof pass through the through holes 10 and 11 of the packing 8 and the end plate 9 so that the external cord 2
4 is connected to the lead wire 25.

The plunger 3 has a bearing 5
Are mounted so as to be slidable in the axial direction, and the front end portion projects forward of the outer case 7. The movable contact 4 is obtained by cutting the round bar to a predetermined length, the movable contact 4 is loosely fitted into a hole 26 bored in the rear end portion of the plunger 3.
The hole 26 is formed by coaxially drilling a tapered hole from the upper and lower surfaces, and the movable contact 4 is supported by line contact at a narrow central portion of the hole 26. In addition, the movable contact 4 is guided by guide grooves 27 formed on the inner peripheral surface of the inner case 1 at the upper and lower portions, and is movable together with the plunger 3 in the left and right directions in FIG. The upper and lower portions contact the fixed contact 23 of the fixed contact 2.

The return spring 6 is located in the inner case 1 and is stretched between the back of the case 1 and the movable contact 4 in a compressed state, and the plunger 3 is moved through the movable contact 4 in FIG. It is biased to the left. Therefore, the movable contact 4 is always in contact with the fixed contact 23 of the fixed contact 2.

Next, the operation of the above embodiment will be described. In the switch, the movable contact 4 is always pressed against the fixed contact 2 by the spring force of the return spring 6 to keep the switch closed. Plunger 3
When the front end of the movable contact 4 is pressed rightward in FIG. 2, the movable contact 4 moves rightward together with the plunger 3 against the spring force of the return spring 6, and the fixed contact 2 is separated.

According to the above embodiment, the fixed contact 2 is
It is composed of a flexible substrate having a shape in which lead pieces 15 and 16 are formed on the left and right sides of the annular portion 14 at the center, and outer and inner end portions 18 of the conductor patterns 18 and 19 of the flexible substrate.
a, 19a, 18b, and 19b were plated with gold, and these inner end portions 18a and 19a were fixed contacts 23.
The manufacturing process of the fixed contact 2 is a single process, and there is no loss of time and cost. Also, since there is no molding process for insert molding the lead frame on the support base, there is no burrs on the molded portion. No molding powder is generated, no contact failure is caused by the molding powder, and there is no influence on parts quality (variation in molding conditions, unstable elements due to etching → movement during molding), etc. The disadvantage that the repetition accuracy, which is the characteristic, is deteriorated can be eliminated.

[0019]

As described above, according to the present invention, since the fixed contact uses the flexible board and the conductor pattern of the flexible board is the fixed contact, the manufacturing process of the fixed contact becomes one step, and the time is reduced. There is no cost loss and there is no molding step for insert molding the lead frame on the support base, so there is no burrs on the molding part, and no molding powder is generated due to the burrs. It is possible to eliminate the problem that the failure does not occur, and that there is no influence of parts quality (variation of molding conditions, unstable elements due to etching → molding movement), etc., and that the repeatability, which is the basic characteristic of the switch, is deteriorated. it can.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a switch structure according to the present invention.

FIG. 2 is a cross-sectional view of the switch structure in two directions.

FIG. 3 is a perspective view of a fixed contact.

FIG. 4 is a plan view of a fixed contact.

FIG. 5 is a side view of the same.

FIG. 6 is a rear view of the same.

FIG. 7 is a plan view of a lead frame in a conventional switch structure.

FIG. 8 is a cross-sectional view along the line AA of FIG. 7;

FIG. 9 is a plan view of a fixed contact in a conventional switch structure.

FIG. 10 is a sectional view taken along the line 9B-B in FIG.

FIG. 11 is a sectional view taken along the line CC in FIG. 9;

[Explanation of symbols]

 2 Fixed contact 14 Ring part 15 Lead piece 16 Lead piece 18 Conductor pattern 19 Conductor pattern 23 Fixed contact

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-118916 (JP, A) JP-A-58-10334 (JP, U) JP-A-61-171139 (JP, U) JP-A-61-171139 35431 (JP, U) Hira 4-29127 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01H 1/22 H01H 13/18

Claims (1)

(57) [Claims] 1. A fixed contact fixed inside a casing, a plunger having a tip protruding outward and slidably mounted on the casing in an axial direction, and mounted to the plunger so as to be slidably perpendicular to the plunger. a cylindrical movable contact, and configured to have a return means for resiliently urging the movable contactor to the fixed contactor side, the fixed contact is annular portion of the central portion
And lead pieces respectively formed on both sides of the annular portion.
Flexible substrate, and both ring
A conductor pattern is formed between each end of the
To form a fixed contact, and the plunger
Is movably inserted to form a conductor constituting the fixed contact.
A switch structure wherein a pattern and the movable contact are configured to be able to contact and separate from each other.