JPH088503Y2 - Heat-responsive switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermally responsive switch such as a bimetal energization type in which a bowl-shaped portion operates in a reverse direction.

[Background Art] Conventionally, as a bimetal energization type thermal response switch,
As shown in FIGS. 7 to 10, a spherical inverted bowl-shaped portion 31
There is one using a bimetal heat-responsive plate 31 composed of a and a tip plate-shaped portion 31b and a base end plate-shaped portion 31c extending on both sides in the diametrical direction. The inverted bowl-shaped portion 31a responds to heat and performs an inversion operation on the contrary to the concavity and convexity. The base plate portion 31c is a fixed plate 32.
And the movable plate 33 is welded to the tip plate portion 31b. As the movable contact 33, as shown in FIG. 10, a button type is used which has a point projection 34 'for resistance welding in the center of the back surface. This is for the following reason. That is, when the inverted bowl-shaped portion 31a is inverted, the tip plate-shaped portion 31b is also curved as shown in FIG. Therefore, if the movable contact 34 is welded to the tip plate-shaped portion 31b on the entire back surface, the bending of the tip plate-shaped portion 31b is hindered,
The operating temperature at which the inverted bowl-shaped portion 31a is inverted changes. Also, the operating temperature varies depending on the welding state.
Therefore, in order to reduce the influence on the inverted bowl-shaped portion 31a,
The movable contact 33 is welded only by the point-like projection 34 '.

However, since it has a structure in which the dot-shaped protrusions 34 'are provided only at the center of the movable contact 33, it is necessary to mold the movable contacts 33 one by one when manufacturing them. Therefore, the movable contact has low productivity and high cost, and the cost of the entire switch increases. In addition, the joint between the heat responsive plate 31 and the movable contact is a pointed protrusion.
Since 34 'is point-jointed, the junction resistance is high. Therefore, during normal use, heat may be generated at the dot-shaped joint portion 34, and an error may occur in the operating temperature of the heat responsive plate 31.

[Purpose of device]

It is an object of the present invention to provide a heat responsive switch whose movable contact is easy to manufacture and whose operating temperature is stable.

[Disclosure of device]

The heat-actuated switch of the present invention comprises an inverted bowl-shaped portion that responds to heat and reverses the concavo-convex direction, and a tip plate-shaped portion and a base plate-shaped portion that extend in a predetermined diameter direction of the inverted bowl-shaped portion. And a conductive heat responsive plate fixedly supported by the base end plate-like portion,
A movable contact attached to the tip plate portion of the heat responsive plate,
In the heat-responsive switch having a fixed contact in contact with the movable contact, the movable contact has a linear joint formed in a direction by a linear protrusion, and the linear joint is provided along the predetermined diameter direction. It is joined to the tip plate portion.

According to the configuration of the present invention, the reversing bowl-shaped portion of the heat responsive plate responds to heat and reverses the concavo-convex direction, so that the warped state of the tip plate-shaped portion changes and the movable contact comes in contact with and separates from the fixed contact. Switch operation.

In this case, since the movable contact is provided not on the inverted bowl-shaped portion but on the tip plate-shaped portion, it is possible to separate the range subjected to the stress due to the joining of the linear joints from the inverted bowl-shaped portion, so that the operation of the inverted bowl-shaped portion The influence of temperature can be avoided, and since the range where stress is generated in the linear joint extends greatly in the direction perpendicular to the linear direction, by joining the linear joint in the specified diameter direction, it is possible to join in the direction perpendicular to it. Compared with the case where it does, it is not necessary to make the tip plate-like portion large in order to avoid the influence of the operating temperature, and it can be made small.

Further, since the linear joint portion is formed by the linear protrusion, the bending of the tip plate portion is not obstructed when the reversing bowl-shaped portion is inverted, and in comparison with the point contact portion provided on the movable contact, A movable contact having a linear protrusion can be manufactured by simply cutting a material in which the linear protrusion is continuously formed over the entire length into a predetermined length. Therefore, the movable contact can be easily manufactured and the cost can be reduced. Further, since the linear joint is joined to the tip plate-like portion, the junction resistance for energization is smaller than that of the conventional dot-like joint, and it is difficult to generate heat. No, the operating temperature is stable.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 5. This heat-responsive switch is composed of an inverted bowl-shaped portion 1a which responds to heat and reverses the concavo-convex shape, and a tip plate-shaped portion 1b and a base end plate-shaped portion 1c extending in a predetermined diameter direction of the inverted bowl-shaped portion 1a.
And a conductive heat-responsive plate 1 fixedly supported by a fixed plate 2 by a base plate 1c, a movable contact 3 attached to a tip plate 1b of the heat-responsive plate 1, and a movable contact 3 In the heat responsive switch having a fixed contact (not shown) in contact with the movable contact 3, the movable contact 3 forms a linear joint 4 on the surface by a linear projection, and the linear joint 4 is formed in the predetermined diametrical direction. It is joined to the tip plate portion 1b along the center line L.

The heat responsive plate 1 is made of bimetal, trimetal, shape memory alloy, or the like. The inverted bowl-shaped portion 1a has a spherical shape centered on the point O. The movable contact 3 is formed by cutting a hoop-shaped material 1'having a linear protrusion 4'along the entire length in the center of the back surface thereof into a predetermined length m as shown in FIG. The linear protrusion 4 ′ becomes the linear joint 4 by resistance welding to the heat responsive plate 1.

FIG. 3 shows a protective device with a fuse which incorporates this thermal switch. The heat responsive plate 1 is joined at its base end to the fuse bimetal terminal 6 on the base 5, and the fixed contact 7 in contact with the movable contact 3 is provided integrally with the bimetal side external terminal 8. The fuse-side external terminal 9 is integrally formed with the fuse terminal 10, and the fuse terminal 10 and the fuse bimetal terminal 6 are formed.
Are connected with a fuse 11. The fuse 11 is located below the heat responsive plate 1, and the movable contact 3 of the heat responsive plate 1 is in constant contact with the fixed contact 7. Therefore, the fuse 11 and the contact portion of the thermoresponsive switch are connected in series between the fuse-side external terminal 9 and the bimetal-side external terminal 8.

Operation In the configuration shown in FIG. 3, when a large overcurrent flows between the fuse side external terminal 9 and the bimetal side external terminal 8, the fuse 11 is blown. In the case of an overcurrent that does not blow the fuse 11, the concavo-convex inversion operation is performed when the inverted bowl-shaped portion 1a of the thermal responsive plate 1 reaches a predetermined temperature due to heat generation of the fuse 11 or heat from the outside of the thermal responsive switch. Therefore, the movable contact 3 and the fixed contact 7 are separated from each other, and the circuit is cut off. When the heat responsive plate 1 is cooled, the movable contact 3 and the fixed contact 7 come into contact again.

Although it operates as described above, according to this configuration, since the movable contact 3 is joined to the heat responsive plate 1 by the linear joint portion 4,
The movable contact 1 is obtained only by cutting the hoop-shaped material 1'shown in FIG. 2 into a predetermined length m. Therefore, the movable contact 1
Can be easily manufactured and the cost can be reduced.

Since the linear joint portion 4 is along the center line L of the heat responsive plate 1, it does not hinder the bending of the tip plate portion 1b when the inverted bowl portion 1a is inverted. Therefore, the influence on the reversing operation temperature is small.
This will be described in detail. As shown in FIG. 4 and FIG. 5, when the linear joint portion 4 is along the direction of the center line L of the heat responsive plate 1, the slightly curved tip plate portion 1 b is the linear joint portion 4 of the linear joint portion 4. A dent d is produced by joining. The chain line in FIG. 5 shows the state before joining. The shaded area Q in FIG. 4 indicates the area where the stress is generated. However, this stress does not act on the inverted bowl-shaped portion 1a that performs the inversion operation, and therefore does not affect the operating temperature of the inverted bowl-shaped portion 1a.

As shown in FIG. 6, when the linear joint portion 4 ′ is oriented in the direction orthogonal to the center line L, the stress due to the joining of the linear joint portion 4 ′ is as shown by the chain line range Q ′ in the same figure. Inverted bowl 1a
Spread to Therefore, the operating temperature of the inverted bowl-shaped portion 1a is affected, and the operating temperature becomes unstable. Therefore, in order to avoid this, it is necessary to lengthen the tip plate portion 1b.

Further, since the heat-responsive switch of this structure is joined by the linear joint portion 4, the joint resistance for energization is smaller than that of the conventional dot joint portion, and it is difficult to generate heat. Therefore, the switch operating temperature is not deviated by the heat generated at the joint, and the operating temperature is stable.

In addition, although the said Example demonstrated the case where the linear joining part 4 was welded, you may join by other methods, such as caulking. That is, it may be a straight line and a direction along the center line L.

[Effect of device]

Since the thermal contact switch of the present invention has the movable contact on the tip plate-like portion instead of the reversing bowl-shaped portion, the range receiving the stress due to the joining of the linear joint can be separated from the reversing bowl-shaped portion. The influence of the operating temperature of the bowl-shaped part can be avoided, and especially the range where stress is generated in the linear joint greatly extends in the direction perpendicular to the straight line direction. Compared with the case of joining in a right angle direction, it is not necessary to increase the size of the tip plate portion in order to avoid the influence of operating temperature, and it is possible to reduce the size.

Further, since the linear joint portion is formed by the linear protrusion, the bending of the tip plate portion is not obstructed when the reversing bowl-shaped portion is inverted, and in comparison with the point contact portion provided on the movable contact, A movable contact having a linear protrusion can be manufactured by simply cutting a material in which the linear protrusion is continuously formed over the entire length into a predetermined length. Therefore, the movable contact can be easily manufactured and the cost can be reduced. Further, since the linear joint is joined to the tip plate-like portion, the junction resistance for energization is smaller than that of the conventional dot-like joint, and it is difficult to generate heat. The effect is that the operating temperature is stable.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a perspective view of the material of the movable contact, and FIG. 3 is a plan view of a protective device with a fuse incorporating the thermal switch, and FIG. Is an operation explanatory view showing a partial upper surface of the heat responsive plate, FIG. 5 is a partial sectional view of the heat responsive plate, FIG. 6 is an operation explanatory view of a comparative example, FIG. 7 is a plan view of a conventional example, 8 is a sectional view thereof, FIG. 9 is an exploded perspective view taken along line IX-IX of FIG. 7,
FIG. 10 is a perspective view of the movable contact. 1 ... Thermal response plate, 1a ... Inverted bowl-shaped part, 1b ... Tip plate-shaped part, 1c ... Base plate-shaped part, 3 ... Movable contact, 4 ... Linear joint part

Claims (1)

[Scope of utility model registration request] 1. A base comprising: an inverted bowl-shaped portion that performs a reversing operation in response to heat in a reverse manner, and a tip plate-shaped portion and a base end plate-shaped portion extending in a predetermined diameter direction of the inverted bowl-shaped portion. A heat-responsive switch provided with a conductive heat-responsive plate fixedly supported by an end plate-like portion, a movable contact attached to the tip plate-like portion of the heat-responsive plate, and a fixed contact in contact with the movable contact, The movable contact has a linear joint formed on the surface by a linear projection, and the linear joint is joined to the tip plate portion along the predetermined diameter direction.