JPH08266016A - Heat-operated switch for sealed electric compressor - Google Patents

Abstract

PURPOSE: To eliminate a heating process and at the same time facilitate the work of fitting an electrically insulating cover onto a heat-operated switch by fixing an airtight container in the state that an adhesive material is applied to the surface of the airtight container side of the electrically insulating cover. CONSTITUTION: A heat-operated switch 11 is composed of a switch main body having a metallic airtight container 3 and an insulating cover 12. The insulating cover 12 is folded in two so that an adhesive surface 12A is positioned on the inside and is applied to the airtight container 3 of the heat-operated switch 11, thereby packing and fixing the switch. At that time, the direction in which the airtight container 3 is held between the insulating covers 12 can be a longitudinal direction to the airtight container or a lateral direction thereto. As a result, the positioning of the metal-made sealed container of the switch is facilitated and since the work of shrinking the insulating cover becomes unnecessary, the work of covering the metal-made sealed container of the switch with the insulating cover can be facilitated, so that it my be automated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-actuated switch used in a hermetic electric compressor.

[0002]

2. Description of the Related Art In order to protect the electric motor from burnout during abnormal operation such as overload operation of the hermetic electric compressor, an overcurrent of the electric motor and an abnormal temperature of the electric motor and the refrigerant are stored in the container of the hermetic electric compressor. A heat-responsive switch that operates in response to is installed. FIG. 6 is a cross-sectional view showing an example of the hermetic electric compressor to which the heat-responsive switch is attached.
FIG. 7 is a cross-sectional view taken along the line AA of the hermetic electric compressor of FIG. 6.
In this hermetic electric compressor 101, a heat responsive switch 106 covered with an electrically insulating coating 105 is attached by a binding string 107 in contact with the surface of a coil end 104 of an electric motor 103 housed in a hermetic container 102. There is. The heat-responsive switch 106 thus mounted on the coil end 104 can quickly respond to a change in the coil surface temperature, and because the heat-responsive switch 106 is exposed to the refrigerant in the closed container 102, the refrigerant temperature change. You can quickly respond to.

FIG. 8 shows a conventional heat-responsive switch 106. The switch portion of the heat-responsive switch 106 is composed of a pressure-resistant metal airtight container 108, and the surface of the pressure-resistant container as a charging part and an electric motor. In order to insulate the coil from the coil, an electrically insulating coating 105 such as a tubular polyester film is covered and fixed by a method such as heat shrinking so as not to be displaced from a predetermined position.

[0004]

However, in the conventional heat-responsive switch 106, it is difficult to automate the work of inserting the airtight container 108 into the tubular electrically insulating coating 105 and arranging the airtight container 108 at a predetermined position. Met. The cause is that the air-tight container 108 of the heat-responsive switch is covered with the electrically insulating coating 1
If the inner diameter of the electrically insulating coating is increased to make it easier to insert into 05, the position of the airtight container may be displaced before the heat shrinking work. It was very difficult to insert a thermo-responsive switch having a circular cross section, and the workability was extremely poor not only in automation but also in manual work.

The end portion 105A of the electrically insulating coating 105 is also provided.
Since it retains a cylindrical shape even after thermal contraction and is in a hollow state, the binding string 10 to the coil end 104 of the electric motor is
In the case of fixing with 7, it is not sufficiently fixed unless the end portion 105A is crushed so as to crush the cylindrical shape of the end portion 105A, and a relatively hard material such as a polyester film is used as the electrically insulating coating 105. To tie it in that way requires a stronger force than other parts, leading to deterioration of workability.

In addition, in the heating process for heat-shrinking the electrically insulating coating 105, not only the electrically insulating coating portion but also the entire heat responsive switch 106 including the lead wire is heated. The electrically insulative coating on the lead wire can cause dimensional changes.

[0007]

Therefore, in the heat-actuated switch for a hermetically-sealed electric compressor according to the present invention, an airtight container made of metal is provided, and an adhesive material is applied to the surface of the electrically insulating coating on the airtight container side. It is characterized by enclosing and fixing the airtight container in a sealed state, and it is possible to omit the heating process in the installation work of the electrically insulating coating and facilitate the automation of the installation work of the electrically insulating coating to the thermal switch. It was done.

Further, by using a cloth-like, non-woven cloth-like or paper-like sheet such as glass cloth, glass non-woven cloth, aramid paper or the like as the electric insulating covering, a flexible electric insulating covering can be obtained.

Further, high heat resistance can be obtained by using polyamide, polyimide or glass fiber as the electrically insulating coating.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermoresponsive switch for a hermetic electric compressor of the present invention (hereinafter simply referred to as a thermoresponsive switch) will be described below with reference to the drawings. FIG. 1 shows a thermoresponsive switch 1 according to the present invention, which has an electrically insulating coating (hereinafter referred to as an insulating coating) 2
Shows the state in which the airtight container of the switch body is covered. FIG. 2 shows a state immediately before the heat-responsive switch 1 of FIG. 1 is covered with the insulating coating 2. The metal airtight container 3 of the switch body has a substantially cylindrical housing 4 with one end closed and this housing. 4 and a cover plate 5 which is airtightly fixed to the open end of the cover plate 4. A conductive lead pin 6 penetrates through the cover plate near the center of the cover plate 5 and is hermetically insulated by a filler 7 such as glass. It is fixed. Lead wires 8A and 8B are conductively fixed to the lead pin 6 and the housing 4, respectively, and the lead wires 8A and 8B are electrically connected to a switch mechanism inside the airtight container.

The insulating coating 2 is made of, for example, a so-called adhesive tape having a base material of glass cloth or the like using glass fiber and having an adhesive surface 2A to which an adhesive material is applied in advance. The airtight container 3 is enclosed and fixed in the insulating coating 2 by winding the insulating coating 2 around the airtight container 3 with the adhesive surface 2A inside.

Since the thermoresponsive switch of the present invention is used inside the closed container of the closed type electric compressor, the material of the insulation coating 2 is not limited to the above glass cloth, but may be polyamide such as nylon or aramid, polyimide, or the like. It has oil and refrigerant resistance like conventional polyester film, and
A material that can be used at a high temperature of 50 ° C. or higher is preferable. As the adhesive material, various adhesive materials such as rubber-based, silicon-based, and acrylic-based materials can be used, but it is needless to say that a material excellent in oil / refrigerant resistance is preferable.

The thermoresponsive switch 1 is mounted on the coil end 103 of the electric motor in the closed container of the electric compressor by a binding cord 9 as shown in FIG. By using a paper-like material, a flexible insulating coating can be obtained as compared with a film-like one, and as shown in FIG. The work is easy because the installation does not require an excessive force. Examples of such insulating coating include glass cloth using glass fiber, glass non-woven fabric, polyester non-woven fabric, Nomex paper which is an aromatic polyamide (aramid), etc., and obtain a flexible insulating coating that cannot be obtained with a film-like sheet. This makes it easier to handle the insulation coating and also to secure the switch to the closed container.

Further, in the above-mentioned example, an example in which the insulating coating is wound around the airtight container of the switch has been described, but in addition to this, the insulating coating like the thermal responsive switch 11 shown in FIGS. 4A and 4B, for example. Alternatively, the switch 12 may be folded and folded in two so that the adhesive surface 12A faces inward, the airtight container 3 of the switch is sandwiched, and at least the peripheral portion 12B thereof is attached to fix the switch. In this case, insulation coating 1
Needless to say, the direction in which the airtight container 3 is sandwiched by 2 may be either vertical or horizontal with respect to the airtight container.

Further, as shown in FIG. 5, the insulating coating 22 is divided into an upper coating 22A and a lower coating 22B, and the airtight container 3 of the switch is sandwiched by both coatings, and the peripheral portions of the upper and lower coatings are adhered to each other to fix the switch. You may. In this case, the thickness and material of the upper coating 22A and the lower coating 22B can be changed.

An insulating coating having a thickness of 0.15 mm or more must be provided between the switch and the coil of the electric motor in consideration of the withstand voltage performance. However, when handling such a thickness, for example, a polyester film is used. However, it is very difficult to sandwich the switch with one sheet of insulating coating because the insulating coating becomes rigid and inferior in flexibility. Therefore flexible thickness, for example 0.05mm
It is necessary to achieve both flexibility and dielectric strength performance by stacking multiple insulation coatings of a certain degree.

However, according to the example of FIG. 5, for example, the lower coating 22B which is required to have a high withstand voltage has a thickness of 0.15 mm or more, and the upper coating 22A is thinner in consideration of flexibility. By using one, it becomes easy to sandwich the switch between both coatings even when using a film that becomes stiffer as the thickness increases.

Further, in the example of FIG. 5, if the performance of the adhesive is sufficient, it is not always necessary to apply the adhesive to the inside of both coatings, and only one of the coatings is coated with the adhesive. You can leave it. For example, the adhesive is applied only to the adhesive surface 22B1 of the lower coating 22B shown as the upper surface in FIG.
After mounting the closed vessel 3 of the switch on the adhesive surface 22B1, the peripheral edge of the adhesive surface 22B1 of the lower coating 22B is brought into contact with the peripheral edge of the upper coating 22A for adhesion, thereby encapsulating and fixing the switch between both coatings. You can

As the material of the insulating coating, polyphenylene sulfide (PPS), fluororesin, etc. may be used in addition to the above-mentioned polyester, polyamide such as nylon and aramid, polyimide, glass fiber. In addition, since non-woven fabric or cloth-like insulation coating has fine pores due to its structure, sufficient withstand voltage cannot be obtained at the same thickness compared to film-like one, and the thickness as a sheet increases as it is. I have no choice. In this case, by using a sheet having a composite structure in which a sheet such as a non-woven fabric and a thin film are bonded together in advance as an insulating coating, a thin insulating coating with high withstand voltage performance can be obtained with almost no loss of flexibility. I can do things.

In the embodiment, the lead wires of the switch body and the housing are directly conductively fixed to the lead wires, but the lead wires are connected via terminals such as tab terminals. It goes without saying that the same effect can be obtained even with the one. Further, although the description has been given by taking as an example the case where the heat responsive switch is fixed to the coil end with the binding string, the heat responsive switch may be fixed with, for example, a binding band made of nylon or the like and having a ratchet mechanism instead of the binding string.

[0021]

According to the heat-actuated switch of the present invention, it becomes easier to position the metal closed container of the switch as compared with the conventional one, and the heat shrinking work of the insulating coating which has been conventionally performed becomes unnecessary. Therefore, the work of covering the metal closed container of the switch with the insulating coating becomes easy, and this work can be automated. Furthermore, by using a flexible insulating coating, it is easy to attach the heat-responsive switch to the electric motor.

[Brief description of drawings]

FIG. 1 is an embodiment of a heat-actuated switch for a hermetic electric compressor according to the present invention.

FIG. 2 shows a state of the thermoresponsive switch of FIG. 1 immediately before being covered with an insulating coating.

FIG. 3 shows a state in which the thermal switch of FIG. 1 is attached.

FIG. 4 is another embodiment of the thermal switch of the present invention.

FIG. 5 is another embodiment of the thermal switch of the present invention.

FIG. 6 is a cross-sectional view showing an example of a hermetic electric compressor to which a conventional heat responsive switch is attached.

7 is a sectional view of the hermetic electric compressor of FIG. 6 taken along the line AA.

FIG. 8 is an example of a conventional thermal response switch.

FIG. 9 shows a state in which the thermal switch of FIG. 8 is attached.

[Explanation of symbols]

 1, 11: Heat-responsive switch 2, 12, 22: Insulation coating 2A, 12A, 22B1: Adhesive surface 22A: Upper coating 22B: Lower coating 3: Metal airtight container 4: Housing 5: Lid plate 6: Lead pin 7: Filling Material 8A, 8B: Lead wire

Claims (8)

[Claims] 1. Used in a container of a hermetic electric compressor,
It has a metal airtight container, and the surface of this airtight container is covered with an electrically insulative coating, and the airtight container is enclosed in a state in which an adhesive material is applied to the surface of this electrically insulative coating on the airtight container side. Thermally-actuated switch for hermetically-sealed electric compressors that is fixed. 2. The heat-actuated switch for a hermetic electric compressor according to claim 1, wherein the electrically insulating coating is made of a flexible material that can be covered along the shape of the airtight container. 3. The heat-responsive switch for a hermetically-sealed electric compressor according to claim 2, wherein the electrically insulating coating is cloth-shaped. 4. The heat-responsive switch for a hermetically-sealed electric compressor according to claim 2, wherein the electrically insulating coating is a non-woven fabric. 5. The heat-responsive switch for a hermetically-sealed electric compressor according to claim 2, wherein the electrically insulating coating is paper-shaped. 6. A heat-actuated switch for a hermetic electric compressor according to claim 1, wherein the material of the electrically insulating coating is polyamide. 7. The heat-actuated switch for a hermetic electric compressor according to claim 1, wherein the material of the electrically insulating coating is polyimide. 8. A heat-actuated switch for a hermetic electric compressor according to claim 1, wherein the material of the electrically insulating coating is glass fiber.