JPH08163830A - Protector for hermetic motor compressor - Google Patents

Abstract

PURPOSE: To obtain a highly reliable protector for hermetic motor compressor which can be fixed easily and rigidly. CONSTITUTION: The protector 10 comprises an internal protector 13 and an insulating cluster socket 12. The protector 13 constitute an airtight container defined by a metal cover plate 13D and a container 13C wherein the fringe part of the cover plate serves as a flange part 13E having a parallel part. A lead wire 13A of the protector is bonded to a connection terminal 14 and the cluster socket 12 has a terminal inserting part 12C and a protector holding part 12G. The protector is loaded to the cluster socket by inserting the connection terminal 14 into the terminal inserting part 12C and sliding the flange part 13E into the protector holding part 12G. Since the protector can be secured rigidly without being covered by the cluster socket or the like, the terminal is protected against damage thus enhancing the thermal sensitivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective device for an electric compressor, which is attached to the inside of a hermetic housing of an airtight terminal in a hermetic electric compressor or the like and detects overheating of a coil or a refrigerant of the electric motor.

[0002]

2. Description of the Related Art There are various conventional protective devices for hermetic electric compressors in which an airtight internal protector (hereinafter referred to as "protector") is arranged in a hermetically sealed housing of the electric motor. Recently, a structure in which it is mounted on an airtight terminal of a hermetic housing has been proposed. For example, in Japanese Utility Model Laid-Open No. 5-27291, one lead terminal of a protector is connected to one of lead wires from an electric motor, and a connection terminal is fixed to the other lead terminal, and the connection terminal is housed in a cluster socket. It is described that the protector is fixedly held on the side surface of the cluster socket, and the cluster socket is attached to the airtight terminal. According to this method, it is easy to attach the protector, but since the protector is fixed to the cluster socket with only one connecting terminal, the lead wire from the motor is pulled when the cluster socket is attached to the airtight terminal. If the protector is damaged, an unreasonable force is applied to the protector, especially a force in the twisting direction, which may deform and damage the connection terminal and the lead terminal.

On the other hand, Japanese Patent Laid-Open No. 3-156183 discloses a protector mounted on a cluster socket and then integrally covered with a heat-shrinkable insulating tube (hereinafter referred to as a tube). . In this example, by fixing the protector to the cluster socket with a tube, even if the lead wire from the motor is pulled when the cluster socket is attached to the airtight terminal, excessive force will not be applied to the protector terminal. Has been done.

[0004]

[Patent Document 1] Japanese Unexamined Patent Application Publication No.
In the example of Japanese Laid-Open Patent Publication No. 156183, heating is difficult because the number of parts is increased and the tube must be contracted while the protector and the cluster socket are connected to the electric motor, and the conductive terminal of the airtight terminal is connected. There is a problem that the workability is significantly deteriorated due to the directionality at the time of mounting because the hole for opening is formed in the tube. Further, both of the conventional examples have a drawback that the protector is not directly exposed to the flow of the refrigerant because it is wrapped in the tube, and the thermal response is impaired.

As described above, it has heretofore been difficult to achieve both robustness and easiness of attaching the protector to the cluster socket and good responsiveness to ambient temperature.

[0006]

Therefore, in the protective device for a hermetic electric compressor according to the present invention, there is provided an internal protector which constitutes an airtight container by a metal container and a cover plate, and a cluster socket constituted by an insulator. A cover plate of the protector has a flange portion having a portion substantially parallel to the peripheral portion, and a connecting terminal is fixedly connected to the protector,
The cluster socket is provided with a connection terminal insertion part and a protector holding part, insert the connection terminal of the internal protector into a predetermined position of the insertion part of the cluster socket, and slide the flange part of the internal protector to the protector holding part. By storing and holding the internal protector, the heat-sensitive part of the internal protector is firmly held in a predetermined posture and position without hiding or holding it, and most of the heat-sensitive part of the electric compressor is not covered by the cluster socket. The feature is that it is exposed to the refrigerant in the housing.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a so-called high-pressure housing hermetic electric compressor that houses the protective device of the present invention, and FIG. 2 is a cross-sectional view of the hermetic electric compressor of FIG. Is. This hermetic electric compressor 1 has a lid 2
The lower container 3 constitutes a closed container, and an electric motor 4 and a compressor 5 having a well-known structure are housed and fixed in the closed container. A suction pipe 6 for introducing a refrigerant sent from a heat exchanger (not shown) is connected to the compressor 5 through the hermetically sealed container, and the refrigerant compressed by the compressor 5 is stored in the hermetically sealed container. It is discharged and flows around the electric motor, and is sent again from the discharge pipe 7 to the heat exchanger. A through hole 2A is provided in a part of the closed container, for example, the lid 2, and a glass sealed terminal 8 for connecting the electric motor 4 inside the closed container to an external power source is hermetically fixed by welding or the like in this through hole. There is.
Lubricating oil 9 for the electric motor 4 and the compressor 5 is enclosed in the closed container.

In the present embodiment, the glass sealed terminal 8 has three conductive terminals 8A, and each conductive terminal is hermetically fixed through an electrically insulating material such as glass. A protective device 10 is attached to the inside of the closed casing of the conductive terminal 8A, and each conductive terminal is connected to each of a plurality of lead wires 11 from the winding of the electric motor via the protective device 10. .

The protection device 10 will be described with reference to FIGS. 3 to 6. FIG. 3 is a perspective view of the protective device 10 of the present invention. The protective device 10 is composed of a cluster socket 12 and an internal protector 13. The cluster socket 12 is made of an insulating material such as synthetic resin, and has a shape shown in FIG. 4 (A) on the front surface and in FIG. 4 (B) on the back surface. Further, the internal protector 13 shown in FIG. 5 has a well-known structure in which an opening / closing mechanism using a heat responsive body such as bimetal is provided inside a metal hermetic container, and the description of the internal structure will be omitted. For example, JP-A-2-227928 and JP-A-5-363.
The structure is as shown in Japanese Patent Publication No. 35-35, and it is a structure for transmitting heat from the outside to the heat responsive body via the metal container. FIG. 6 is a plan view in which only the cluster socket of the protection device 10 is cut, and FIG. 7 is a side view seen from the direction of arrow B in FIG.

The cluster socket 12 has terminal insertion portions 12A, 12B, 1 for holding connection terminals having a well-known structure inside.
Although not shown in the drawings, a connecting terminal attached to the tip of the lead wire 11 from one end of the main winding and the auxiliary winding of the motor winding is provided in 12A and 12B of the terminal insertion portion. Inserted and held up to the positions of the through holes 12D, 12E for inserting the conductive terminal 8A of the airtight terminal 8 described above,
Further, the connection terminal 14 fixed to one lead terminal 13A of the protector 13 is inserted into the terminal insertion portion 12C and is similarly held at the position of the through hole 12F. The connection terminal 14 is fixed to the lead terminal 13A by a method such as welding via a connecting fitting having a shape having an L-shaped angle portion, for example. The tab terminal 15 is also fixed to the other lead terminal 13B by welding or the like. Although not shown, the tab terminal 15 is inserted into a connection terminal such as a receptacle attached to the tip of the lead wire 11 from the motor winding.

The protector 13 constitutes an airtight container by a metal container 13C and a lid plate 13D, and has a flange portion 13E having a portion substantially parallel to the peripheral edge portion of the lid plate 13D. Since the airtight container of the protector 13 has a structure capable of withstanding the high pressure in the closed housing of the electric compressor, a relatively thick metal plate is used for the lid plate 13D, and the container 13C enhances thermal conductivity to the inside. Therefore, instead of using a metal plate that is thinner than the lid plate, a dome shape is used to ensure pressure resistance.

In the present invention, a protector holding portion 12G is provided on the side of the cluster socket 12 having the protector. The protector holding portion 12G has a structure in which a flange portion 13E having a large diameter is held from both sides as a welded portion of the metal container 13C and the cover plate 13D of the protector, and the protector 13 holds the connection terminal 14 at the terminal insertion portion. 12C and the flange portion 13E is slidably inserted into the protector holding portion 12G to be securely fixed. At this time, the metal container 13C of the protector 13 is mounted so that almost the entire metal container 13C faces away from the cluster socket 12. 12H is protector 1
3 is a notch for inserting the lead terminals 13A and 13B into the partition of the cluster socket so that 3 can be mounted by sliding.

As shown in FIGS. 1 and 2, when the protective device 10 thus constructed is mounted on the airtight terminal 8 of the hermetic electric compressor 1, the conductive terminals 8A of the airtight terminal 8 are respectively described above. Through holes 12D, 12E of the cluster socket 12 of
By inserting into the 12F, the connection terminal is securely fitted and fixed to the conductive terminal of the airtight terminal. Since the protector 13 is securely held by the cluster socket 12 as described above, even if the lead wire from the electric motor is pulled, an unreasonable force in the twisting direction is not applied to the protector. 14 and the lead terminal 13A are not deformed and damaged.

The operation of this protection device will be described below.
Normally, the temperature of the refrigerant in the hermetically sealed housing is below a certain value, and by keeping the operating temperature of the thermal actuator in the protector at a temperature slightly higher than this value, the power supply to the electric motor will not be interrupted. If any abnormality occurs and the electric motor is restrained or overloaded during operation, the winding temperature of the electric motor abnormally rises and the refrigerant temperature also rises. At this time, by detecting an increase in the temperature of the refrigerant, the thermal responsive body in the protector operates to open the contacts of the opening / closing mechanism, so that the energization is surely interrupted before the winding of the electric motor is burnt. Further, in the protective device of the present invention, most of the metal airtight container of the protector, especially the metal container side is directly exposed to the flow of the refrigerant, so that the refrigerant is retained despite the structure that reliably holds the airtight container. It is possible to secure a quick thermal response without sacrificing the heat conduction to the thermal actuator with respect to the rise in temperature.

In the present invention, a protector having a flange portion having a portion substantially parallel to the peripheral portion of the cover plate is used. For example, other protectors include a circular lid plate and a substantially cylindrical metal container. However, in such a cylindrical shape, when the flange around the cover plate of the protector is slid and attached as in the present invention, there is little substantial holding portion and the container is rotatable with respect to the central axis of the container. Therefore, the stability is poor and the connection terminals may be damaged. Also, if this cylindrical metal container is structured to be held by a cluster socket, stability is increased, but there is a possibility of damage to the connection terminal because it is still rotatable with respect to the center axis of the container.
Further, most of the surface of the metal container is not directly exposed to the flow of the refrigerant, so that the heat following property is deteriorated.

However, in the protective device of the present invention, a protector having a portion substantially parallel to the flange portion is used, and the substantially parallel flange portion is sandwiched between the cluster sockets to hold the protector and a metal container of the protector. The entire metal container, which is the main heat-sensitive part and is thinner than the lid plate, is directly exposed to the flow of refrigerant in the electric compressor by adopting a structure in which almost the entire part is mounted facing away from the cluster socket. Since it is possible to transmit the temperature change to the internal thermo-responsive body quickly, the thermal response is good.

In the present embodiment, the protective device is attached to the hermetically-sealed electric compressor of the so-called high-pressure housing, which is attached to the hermetically-sealed terminal provided near the refrigerant discharge pipe.
The protective device of the present invention may be attached to a so-called low pressure housing hermetic electric compressor at a position where the change of the refrigerant temperature due to the rise of the coil temperature at the time of abnormality can be reliably grasped.

Further, the internal protector has been described by taking a two-pin type in which two lead terminals insulated from a metal container are fixed to the connection terminals, but in addition to this, for example, one connection terminal is used as a cover plate. Needless to say, it may be a fixed one-pin type, or may have a structure in which the lead wire is directly fixed to the lead terminal without the connection terminal on the connection side with the motor winding.

[0019]

According to the protective device for a hermetic type electric compressor of the present invention, it is necessary to add the simple structure to the cluster socket so as to take the labor and extra parts as in the conventional protective device. You can easily and securely hold the internal protector, and even if the lead wire from the motor is pulled, the protector's lead terminal and connection terminal will not be subjected to excessive force in the twisting direction, and the connection terminal will not be deformed. It can have a structure that prevents damage.

Further, the protector is not limited to the shape shown in the figure, but a protector having a portion substantially parallel to the flange portion is used, and the protector is held by the flange portion. In order to hold a protector such as the one described above, the heat sensitive part is not covered and firmly held in a predetermined posture and position, and the entire metal container, which is the main heat sensitive part, is directly exposed to the flow of the refrigerant in the electric compressor. As a result, temperature changes can be quickly transmitted to the internal thermal actuator, and thermal response can be improved, and the protection performance can be dramatically improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a hermetic electric compressor to which an embodiment of a protection device of the present invention is attached.

FIG. 2 is a sectional view of the hermetic electric compressor of FIG.

FIG. 3 is a perspective view of an embodiment of a protective device for a hermetic electric compressor according to the present invention.

4 is a perspective view of a cluster socket used in the protection device of FIG.

5 is a perspective view of an internal protector used in the protection device of FIG.

6 is a partial cross-sectional view of the protection device of FIG.

FIG. 7 is a side view of the protection device of FIG. 3 viewed from the direction of arrow B.

[Explanation of symbols]

 1: Hermetic electric compressor 8: Glass sealed terminal 8A: Conductive terminal 10: Protective device 11: Lead wire 12: Cluster socket 12A, 12B, 12C: Terminal insertion part 12G: Protector holding part 13: Internal protector 13A, 13B : Lead terminal 13C: Metal container 13D: Lid plate 13E: Flange portion 14: Connection terminal 15: Tab terminal

Claims (1)

[Claims] 1. A protective device which is attached to an airtight terminal provided in an airtight housing of a hermetic electric compressor and is used in the airtight housing, wherein the airtight container is composed of a metal container and a cover plate. There is a protector and a cluster socket made of an insulating material, the cover plate of the internal protector has a flange portion having a portion substantially parallel to the peripheral portion, and the connection terminal is fixedly connected to the internal protector, The cluster socket is provided with a connection terminal insertion part and a protector holding part, insert the connection terminal of the internal protector into a predetermined position of the insertion part of the cluster socket, and slide the flange part of the internal protector to the protector holding part. By storing and holding it, most of the heat-sensitive part of the internal protector is clustered. A protective device for a hermetic electric compressor that is exposed to the refrigerant in the housing of the electric compressor without being covered by the compressor.