JPH0366771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rotary switch used for electrically opening and closing electrical appliances such as room air conditioners, refrigerators, dehumidifiers, etc., and particularly relates to a moderation mechanism.

[Prior art]

A conventional rotary switch will be explained with reference to FIGS. 1 to 4. Reference numeral 1 denotes a switch body made of an insulating material such as synthetic resin, which houses parts to be described later.
Reference numeral 2 denotes a cam, which is integrally formed by vertically stacking a switch operation cam part 2a and a positioning cam part 2b. The switch operation cam part 2a has cam surfaces 2a ₁ , 2a ₂ , 2 for operating four movable terminals to be described later.
a ₃ and 2a ₄ , and the positioning cam portion 2b has a curved tip and a star shape. Reference numeral 3 denotes a rotating shaft that passes through the center of the cam 2 and is fixed to the cam 2. The rotating shaft 3 is connected to the hole 1a of the main body 1 and the lid 1 which will be described later.
It is inserted into the hole 12a of No. 2 and is rotatably supported. 4 to 7 are movable terminals and contacts 4a, 5a, 6
a, 7a, and some protrusions 4b, 5b, 6b,
7b. These movable terminals 4 to 7 are housed in the main body 1 so that their protrusions 4b, 5b, 6b, and 7b operate on the cam surfaces 2a ₁ , 2a ₂ , 2a ₃ , and 2a ₄ of the cam 2, respectively. ing. 8 is a fixed terminal, and contacts 4a and 5 of the movable terminals 4 to 7
It has a contact 8a (partially not shown) opposite to a, 6a, and 7a. Reference numeral 9 denotes an insulating plate having a hole 9a slightly larger than the positioning cam part 2b of the cam 2, and is brought into contact with the upper surface of the switch operating cam part 2a. Reference numeral 10 denotes a rectangular movable piece, the upper and lower width dimensions of which are approximately the same as the upper and lower inner diameters of the main body 1, and the left and right width dimensions set smaller than the left and right inner diameters of the main body 1. Therefore, the square-shaped movable piece 10 is arranged to slide left and right. Two recesses 10a are formed above and below the left end surface of the square-shaped movable piece 10, and a circular arc-shaped projection 10b is integrally formed on the left inner surface. Reference numeral 11 denotes a coil spring, which is disposed within the recess 10a and is adapted to constantly press the movable piece 10 to the right. Further, at this time, the circular arc-shaped protrusion 10b comes into contact with the positioning cam 2b. 12
is a lid that closes the upper opening of the main body 1.

In the rotary switch having such a structure, when the rotating shaft 3 is rotated, the cam 2 is also rotated at the same time, and the peak _2b1 of the positioning cam portion 2b is also moved in the rotational direction. As this mountain _2b1 moves, the square-shaped movable piece 10
slides to the left while compressing the coil spring 11. In the position shown in FIG. 2, the coil spring 11 is in its maximum compression state. When the ridge 2b ₁ passes the apex of the arc-shaped protrusion 10b, a force is applied to the arc-shaped protrusion 10b to move it to the right side due to the elastic force of the coil spring 11, and the ridge 2b ₁ and the circle Solitary protrusion 1
A sliding force acts between the curved surfaces of 0b, causing the positioning cam 2b to rotate. At the position shown in FIG. 3 at the end of rotation, the coil spring 11 is in a minimum compression state.

Also, during this time, the protrusions 4b and 5 of the movable terminals 4 to 7 are
b, 6b, and 7b are designed to make a predetermined contact and separation from the cam surfaces 2a ₁ , 2a ₂ , 2a ₃ , and 2a ₄ of the switch operation cam portion 2a.

In the rotary switch having the structure and operation described above, the square-shaped movable piece 10 slides back and forth from side to side between the position shown in FIG. 3 and the position shown in FIG. In order for this sliding to occur smoothly, the upper and lower inner walls 1b of the main body 1,
1c and the upper and lower side surfaces 10c, 1 of the square-shaped movable piece 10
0d requires an appropriate gap. This gap is the second
Since the main body 1 is made of an insulating synthetic resin material as shown in FIG. In particular, this inward warpage varies greatly due to variations in materials, variations in molding conditions, etc. even when molded with the same mold. Further, the portion where the inward warpage is maximum is the central portion of the inner walls 1b, 1c.

Therefore, if the related dimensions are determined by underestimating this inward warping, and if this prediction is wrong and a large inward warping occurs, the inner walls 1b, 1c of the main body 1 will narrow the sides 10c, 10d of the square-shaped movable piece 10. Penetration and sliding resistance increase. As a result, the rotation of the rotary shaft 3 is inhibited, resulting in a rotary switch that has poor sense of moderation and requires a large operating force.

In the worst case, the cam 2 does not rotate and stops at the position where the rotational force applied to the rotating shaft 3 is removed. the result,
There was a drawback that the conduction pattern of the contacts 4a, 5a, 6a, and 7a was broken and the function as a rotary switch was stopped.

Further, the related dimensions are determined by specifying the maximum inward curvature, and when this prediction is exceeded and the inward curvature becomes small, the play of the square-shaped movable piece 10 becomes large and the square-shaped movable piece 10 tilts and slides. As a result, there was a drawback that the operating force for the rotating shaft 3 increased. Furthermore, the second
Depending on whether the process from the position shown in the figure to the position shown in FIG.
It changes as shown in 1 and 2 in the figure. At this time, the stopping angle of the D-cut surface 3a of the rotating shaft 3 changes at the same time. As a result, the stop angle of the camera 17, which is fixed with respect to the D-cut surface 3a, also changes in position, and if this deviation angle is large, there is a drawback in that it may lead to a design complaint.

As countermeasures against these problems, methods have been adopted such as applying lubricant to the sliding parts or increasing the load on the coil spring 11, but these methods have led to higher costs and lower operability.

[Purpose of the invention]

An object of the present invention is to simply and inexpensively provide a highly reliable rotary switch with excellent moderation sense without changing the basic structure of the conventional rotary switch.

[Summary of the invention]

That is, by providing a recess in one of the parts at the center of the sliding part that contacts the main body of the square-shaped movable piece, and by making this recess a non-contact part, the above-mentioned drawbacks have been eliminated.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 5 and 6. Items with the same symbols as conventional ones indicate the same items. The difference from the conventional one is the main body 1 of the square-shaped movable piece 10.
Recesses 10 are provided on both upper and lower side surfaces 10c and 10e that are in contact with
This is because c ₁ and 10e ₁ were provided. This recess 10
Due to the effects of c and 10e, the square-shaped movable piece 10 and the main body 1 are brought into a non-contact state at the center of the sliding part. As a result, even if the wall surfaces 1b, 1c of the main body 1 are warped inwardly, the square-shaped movable piece 10 will not come into contact with the warped portions and the sliding resistance will not increase. Further, this inward warpage is minimum at the corner portions 1d and 1e of the main body 1, and the sliding surface of the square-shaped movable contact piece 10 is also located near the corner portions 1d and 1e. the result,
It becomes possible to slide in a portion with little dimensional change, and the gap between the rectangular movable piece 10 and the main body 1 can be set to the minimum necessary range.

Therefore, the play of the square-shaped movable piece 10 is also reduced, and the change in the stopping angle of the D-cut surface 3a of the rotating shaft 3 is also reduced. As a result, a rotary switch with a small deviation in the stop angle of the camera 17 and an excellent design can be obtained.

According to the present invention, a rotary switch with high contact reliability and excellent moderation can be easily and inexpensively obtained without applying lubricant to the sliding parts or increasing the load of the coil spring 11. be.

FIG. 7 shows another embodiment in which recesses 1b 1 and 1c ₁ are provided in the center of the upper and lower inner walls _1b and 1c of the main body 1, and the same effect as that in FIG. 5 is obtained.

[Effects of the Invention] According to the present invention, due to the effect of the non-contact part provided at the center of the sliding part of the square-shaped movable piece 10 and the main body 1, the dimensional stability of the sliding part is increased, and the moderation sense is excellent and reliable. Easy and convenient rotary switch with high performance
It has the effect of being able to provide it at a low cost.

Moreover, since it can be easily obtained without changing the basic structure of the conventional rotary switch, it has great practical effects.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a conventional rotary switch, Figs. 2 and 3 are plan views explaining the operation of the conventional rotary switch after assembly with the lid removed, and Fig. 4 shows the rotary switch in the position shown in Fig. 3. FIG. 5 is an assembled and exploded perspective view of a rotary switch showing an embodiment of the present invention. FIG. 6 is a plan view of FIG. 5 with the lid removed after assembly. FIG. 7 is a plan view of another embodiment with the lid removed after assembly. DESCRIPTION OF SYMBOLS 1...Main body, 2...Cam, 2a...Cam section for switch operation, 2b...Cam section for positioning, 3...
Rotating shaft, 4 to 7...Movable terminal, 8...Fixed terminal,
10...R-shaped movable piece, 11...Coil spring, 1
2... Lid.

Claims (1)

[Scope of Claims] 1. A cam 2 having a switch operation cam 2a and a positioning cam portion 2b is rotatably mounted via a rotating shaft 3, and movable terminals 4 to 7 are connected in correspondence with the switch operation cam portion 2a. The fixed terminals 8 are arranged corresponding to the movable terminals 4 to 7, and the square-shaped movable piece 10 is arranged in the main body 1 so as to be movable left and right. A coil spring 11 is elastically loaded in the recess 10a in a compressed state, and a circular arc-shaped protrusion 10b is provided on the left inner surface of the square-shaped movable piece 10, and the circular arc-shaped protrusion 10b is connected to the positioning cam portion. 2b, the rotary switch is characterized in that a non-contact portion is provided at the center of the sliding portion of the rectangle-shaped movable piece 10 that contacts the main body 1. 2 Recess 1 in the center of the upper and lower inner walls 1b and 1c of the main body 1
The rotary switch according to claim 1, wherein b ₁ and 1c ₁ are provided. 3 Both upper and lower sides 10c, 10 of the square-shaped movable piece 10
e The rotary switch according to claim 1, wherein recesses 10c ₁ and 10e ₁ are provided in the central portion.