JPH04368739A - Thermostat and manufacture thereof - Google Patents

Abstract

PURPOSE:To simplify the structure of a thermostat and make the assembling easy. CONSTITUTION:A groove is formed in a case 1 and one end of a bimetal 2 is inserted into it. A switch part composed of a pair of lead terminals 5, 6, a movable arm 7, a fixed contact 8, and a movable contact 9 is previously united with a cover part 4 of the case 1. The bimetal 2 is inserted into the case 1 and then a cover part 4 to which the switch part is attached is fixed and thus the assembling of a thermistor is completed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermostat that is simple in structure and easy to assemble, and a method for manufacturing the same.

0002

2. Description of the Related Art Thermostats are used in various fields to open and close contacts using the curvature of a bimetal caused by temperature changes.

0003

However, in the conventional thermostat, one end of the bimetal is fixed, so the structure is complicated and assembly is troublesome.

[0004] Accordingly, an object of the present invention is to provide a thermostat with a simple structure. Another object of the present invention is to provide a method for easily manufacturing a thermostat.

[0005]

Means for Solving the Problems The invention according to claim 1 for achieving the above object includes an insulating case, a bimetal, first and second lead terminals, and a tip portion of the first lead terminal. or a fixed contact made of a conductor fixed here, a movable arm having elasticity with one end fixed to the tip of the second lead terminal, and a conductive member fixed to the other end of the movable arm or here. a movable contact consisting of a body, the case having a space for accommodating the bimetal, the tip portions of the first and second lead terminals, the fixed contact, the movable arm, and the movable contact, The bimetal also has a groove for supporting one end of the bimetal, and the bimetal is deformably disposed at a predetermined position in the case using the groove, and when the bimetal is operated, the bimetal is bent. and press the movable arm by the free end portion of the bimetal, or release the pressure on the movable arm to bring the movable contact into contact with the fixed contact or to separate the movable contact from the fixed contact. The present invention relates to a thermostat characterized by the following configuration. The invention according to claim 2 is the method for manufacturing a thermostat according to claim 1, in which the bimetal, the tip portions of the first and second lead terminals, the fixed contact, the movable arm, and the movable contact are accommodated. preparing a case having a space for supporting one end of the bimetal and a groove for supporting one end of the bimetal;
and preparing a switch partial assembly in which a switch portion including a second lead terminal, the movable arm, the fixed contact, and the movable contact is integrated, and one end of the bimetal is positioned in the groove. The present invention relates to a method of manufacturing a thermostat, comprising the steps of inserting the bimetal into the case and mounting the switch subassembly to the case.

[0006]

[Operation] The bimetal according to claims 1 and 2 is not fixed to the case with a special fixing member. However, the position is limited by the groove provided in the case, so
It does not fall outside the specified range. According to claim 2, the lid of the case includes first and second lead terminals, a movable arm,
If an assembly is formed in advance that integrates the switch portion consisting of a fixed contact and a movable contact, the assembly can be completed by simply attaching the bimetal and the switch portion assembly to the case, making manufacturing extremely easy.

[0007]

Embodiment Next, a thermostat and a method for manufacturing the same according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. The thermostat of this embodiment includes an insulating synthetic resin case 1, a bimetal 2, and a switch subassembly 3 shown in FIG.
and are obtained by assembling as shown in FIG. The switch subassembly 3 includes an insulating synthetic resin cover 4 of the case 1.
First and second lead terminals 5 made of thick metal plates are provided.
, 6, a movable arm 7 made of a thin elastic metal plate that can be elastically deformed, a fixed contact 8, and a movable contact 9 are integrated. The lid portion 4 is formed to fit into a rectangular opening 10 of the case 1, and is formed to abut against a positioning step portion 11 of the case 1. The first and second lead terminals 5 and 6 are integrated into a lid portion 4 having a rectangular planar shape, and penetrate from the outside to the inside, where a switch portion is provided. As is clear from FIG. 3, the movable arm 7 having spring properties extends in a direction perpendicular to the first and second lead terminals 5 and 6, and one end of the movable arm 7 is welded to the tip of the second lead terminal 6. The other end is the free end (
(Yutan). A movable contact 9 is fixed to the other end (free end) of the movable arm 7. The fixed contact 8 is fixed to the tip of the first lead terminal 5. This thermostat has a normally open contact configuration, in which the movable contact 9 at the free end of the movable arm 7 having spring properties is normally separated from the fixed contact 8 as shown in FIG. 5, and when the temperature rises, it comes into contact as shown in FIG. do.

The case 1 has a housing space 12 for the switch portion at the tip of the switch subassembly 3 and the bimetal 2, as shown in FIG. This case 1 has a tapered groove 13 into which one end of the bimetal 2 is inserted, and a semicylindrical protrusion 14 extending inward from the entrance at the center of the lower surface. The height of the protrusion 14 is approximately the same as the height of the curved center of the bimetal 2 at room temperature. The groove 13 of the case 1 becomes narrower as it approaches the side wall of the case 1.
The lower surface of the partition-like protrusion 15 for obtaining the shape of the bimetal 2 is inclined so as not to restrict the curvature of the bimetal 2 at room temperature. Note that the partition-like protrusion 15 protrudes to an extent that substantially coincides with the right end of the second lead terminal 6 so as not to restrict the movement of the movable arm 7. The arrangement of the bimetal 2 at room temperature is approximately symmetrical about the protrusion 14, as shown in FIG.

When assembling the thermostat, the case 1, the bimetal 2, and the switch subassembly 3 are prepared, and the bimetal 2 is first inserted into the case 1. Groove 13
extends from the entrance of the accommodation space 12 toward the back,
One end of the bimetal 2 is easily inserted into the groove 13. The other end of the bimetal 2 is a free end. Next, the switch subassembly 3 is inserted into the case 1. Since the switch portion is supported by the lid portion 4, when the lid portion 4 is attached to a predetermined position on the case 1, a predetermined positional relationship between the switch portion and the bimetal 2 is automatically set. Opening 10 of case 1
Since it is closed by the lid part 4, it becomes a closed type thermostat. Note that the lid part 4 may be integrated with the case 1 only by fitting, or may be integrated with an adhesive,
They may be integrated by mutual welding.

As the temperature of the thermostat rises, the bimetal 2 bends less, and as the temperature rises further, it bends in the opposite direction. When the temperature rises and the bimetal 2 curves, the downward displacement of the center of the bimetal 2 is restricted by the central protrusion 14, and the free end of the bimetal 2 is displaced using the protrusion 14 as a fulcrum. Therefore, due to the relatively small amount of deformation of the bimetal 2, the free end of the bimetal 2 pushes up the free end of the movable arm 7, causing the movable contact 9 to move upward from the fixed contact 8.
can be brought into contact with.

[0011]

[Modifications] The present invention is not limited to the above-described embodiments, but can be modified, for example, as follows. (1) The present invention can also be applied to a case where the switch section is configured so that the fixed contact 8 and the movable contact 9 are in contact with each other at room temperature and are separated when the temperature rises. This normally closed contact structure (
In the case of a thermostat with a break contact structure), the configuration shown in FIG. 6 is used at room temperature. With this configuration, the state shown in FIG. 5 will occur when the temperature rises. (2) The tip of the first lead terminal 5 can also be used as a contact. The tip of the movable arm 7 can be used as a contact point.

0012

As is clear from the above, according to the present invention, the bimetal can be easily attached and the structure can be simplified. Further, by integrating the first and second lead terminals and the like with the lid portion in advance, manufacturing of the thermostat becomes easier.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a thermostat according to an embodiment.

FIG. 2 is a perspective view showing the thermostat after assembly.

FIG. 3 is a plan view of the switch subassembly of FIG. 1;

FIG. 4 is a cross-sectional view of the case.

FIG. 5 is a cross-sectional view of FIG. 2 showing the thermostat at normal temperature.

FIG. 6 is a sectional view of the same part as FIG. 5, showing the thermostat during temperature rise.

[Explanation of symbols]

1 case 2 Bimetal 3 Switch subassembly 13 Groove

Claims (2)

[Claims] [Claim 1] An insulating case, a bimetal, and a first
and a second lead terminal, and a fixed contact consisting of a tip portion of the first lead terminal or a conductor fixed thereto;
The case includes a movable arm having elasticity, one end of which is fixed to the tip of the second lead terminal, and a movable contact made of a conductor fixed to the other end of the movable arm or to the other end of the movable arm. The bimetal has a space for accommodating the tip portions of the first and second lead terminals, the fixed contact, the movable arm, and the movable contact, and has a groove for supporting one end of the bimetal. The bimetal is deformably disposed at a predetermined position in the case using the groove, and when the bimetal is operated, the bimetal curves and the free end portion of the bimetal presses the movable arm. A thermostat characterized in that the thermostat is configured to either release the pressure of the movable arm and bring the movable contact into contact with the fixed contact, or to separate the movable contact from the fixed contact. 2. The thermostat manufacturing method according to claim 1, wherein a space accommodates the bimetal, the tip portions of the first and second lead terminals, the fixed contact, the movable arm, and the movable contact. and preparing a case having a groove for supporting one end of the bimetal, and attaching the first and second lead terminals, the movable arm, and the fixing to the insulating lid of the case. a step of preparing a switch partial assembly in which a switch portion consisting of a contact and the movable contact is integrated; inserting the bimetal into the case so that one end of the bimetal is located in the groove; A method of manufacturing a thermostat, comprising the step of mounting a subassembly in the case.