JP2732039B2 - Protection device for hermetic electric compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection device for an electric compressor, which is mounted inside a hermetically sealed terminal of a hermetic 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 types of conventional protective devices for hermetically sealed electric compressors in which an airtight internal protector (hereinafter referred to as a protector) is arranged in a hermetically sealed housing of the electric motor. A structure which is mounted on an airtight terminal of a sealed housing has recently been proposed. For example, in Japanese Unexamined Utility Model Publication No. 5-27291, one lead terminal of a protector is connected to one lead wire from an electric motor, and a connection terminal is fixed to the other lead terminal, and this connection terminal is housed in a cluster socket. In this case, the protector is fixed and held on the side surface of the cluster socket, and the cluster socket is attached to the airtight terminal. According to this method, the protector can be easily mounted, but since the protector is fixed to the cluster socket with only one connection terminal, the lead wire from the electric motor is pulled when the cluster socket is mounted on the airtight terminal. For example, an excessive force, in particular, a force in the torsion direction may be applied to the protector to deform and damage the connection terminals and the lead terminals.

On the other hand, Japanese Patent Application Laid-Open No. Hei 3-156183 discloses a case where a protector is attached to a cluster socket and then both are integrally covered with a heat-shrinkable insulating tube (hereinafter referred to as a tube). . In this example, the protector is fixed to the cluster socket with a tube so that no excessive force is applied to the terminal of the protector even if the lead wire from the motor is pulled when the cluster socket is attached to the airtight terminal. Have been.

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open
In the example of JP-A-156183, heating is difficult because not only the number of parts is increased but also the tube must be contracted in a state where the protector and the cluster socket are connected to the electric motor, and the conductive terminals of the hermetic terminals are connected. However, there is a problem in that since the holes for the holes are formed in the tube, there is a directivity at the time of mounting, and the workability is remarkably deteriorated. Further, in both of the conventional examples, there is a disadvantage that the protector is not directly exposed to the flow of the refrigerant due to being wrapped by the tube, and the thermal responsiveness is impaired.

As described above, it has conventionally been difficult to achieve both robustness and ease of attachment of the protector to the cluster socket and good responsiveness to ambient temperature.

[0006]

SUMMARY OF THE INVENTION Therefore, in a protection device for a hermetic electric compressor according to the present invention, an internal protector forming an airtight container by a metal container and a lid plate and a cluster socket formed by an insulator are provided. The cover plate of the protector has a flange portion having a portion substantially parallel to a peripheral edge portion, and the cover plate or the lid of the internal protector has a flange portion.
The mode pin connected fixed metallic connection terminals conductively, the cluster socket is provided with a connection terminal insertion portion and the protector holding portion, the protector holding portion the Intana
Structure that holds the flange of the protector from both sides.
The connection terminal of the internal protector.
At the insertion part of the raster socket, and the flange part
Simultaneously slide to the specified position on the protector holder
Insert almost all of the metal case of the Case
By holding and holding it toward the side opposite to the bracket, the heat-sensitive part of the internal protector is firmly held in a predetermined position and location without covering or holding, and most of this heat-sensitive part is connected to the cluster socket. It is characterized in that it is exposed to the refrigerant in the housing of the electric compressor without being covered.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of a so-called high-pressure housing hermetic electric compressor accommodating the protection device of the present invention, and FIG. 2 is a cross-sectional view of the hermetic electric compressor of FIG. It is. The hermetic electric compressor 1 includes a lid 2
And the lower container 3 constitute a closed container, in which a motor 4 and a compressor 5 having a known structure are housed and fixed. A suction pipe 6 for introducing a refrigerant sent from a heat exchanger (not shown) is connected to the compressor 5 through the closed container, and the refrigerant compressed by the compressor 5 is stored in the closed container. The discharged gas 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 supply is hermetically fixed by welding or the like in this through hole. I have.
A lubricating oil 9 for the electric motor 4 and the compressor 5 is sealed in the sealed container.

In this embodiment, the glass-sealed terminal 8 has three conductive terminals 8A, and each of the conductive terminals is air-tightly fixed by an electrically insulating material such as glass. A protective device 10 is mounted inside the closed container of the conductive terminal 8A, and each conductive terminal is connected to each of the 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. FIG. 3 is a perspective view of the protection device 10 of the present invention. The protection device 10 includes a cluster socket 12 and an internal protector 13. The cluster socket 12 is made of an insulating material such as a synthetic resin, and has a shape as shown in FIG. 4A for the front surface and FIG. 4B for the back surface. 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 a bimetal is provided inside a metal closed container, and the description of the internal structure is omitted. For example, JP-A-2-227928 and JP-A-5-363
It has a structure as disclosed in Japanese Patent Publication No. 35-35, in which heat from the outside is transmitted to the heat responsive body via the metal container. FIG. 6 is a plan view of the protection device 10 in which only the cluster socket is cut, and FIG. 7 is a side view as viewed from the direction of arrow B in FIG.

In the cluster socket 12, terminal insertion portions 12A, 12B, 1 for holding therein connection terminals having a well-known structure.
Although not shown, connection terminals attached to the ends of the lead wires 11 from one end of the main winding and the auxiliary winding among the motor windings are illustrated in 12A and 12B of the terminal insertion portions. The above-described hermetic terminal 8 is inserted and held up to the positions of the through holes 12D and 12E for inserting the conductive terminal 8A,
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 connection fitting 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 forms an airtight container with a metal container 13C and a cover plate 13D, and has a flange portion 13E having a portion substantially parallel to the peripheral edge of the cover plate 13D. The airtight container of the protector 13 has a structure that withstands high pressure in the sealed housing of the electric compressor, and a relatively thick metal plate is used for the cover plate 13D. The container 13C enhances the heat conductivity to the inside. Therefore, instead of using a metal plate 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 for holding a flange portion 13E having a large diameter as a welded portion between the metal container 13C of the protector and the cover plate 13D from both sides, and the protector 13 connects the connection terminal 14 to the terminal insertion portion. 12C, the flange 13E is securely fixed by sliding the flange 13E into the protector holder 12G. At this time, the metal container 13 </ b> C of the protector 13 is mounted so that substantially the entire metal container 13 </ b> C faces the side opposite to the cluster socket 12. 12H is protector 1
Notch for inserting lead terminals 13A, 13B into the partition wall of the cluster socket so that 3 can be mounted by sliding.

When the protective device 10 thus configured is mounted on the hermetic terminal 8 of the hermetic electric compressor 1 as shown in FIGS. 1 and 2, each of the conductive terminals 8A of the hermetic terminal 8 is described above. , Through holes 12D, 12E,
By inserting the connection terminal 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 and the connection terminal is not connected. 14 and the lead terminals 13A are not deformed and damaged.

The operation of the protection device will be described.
Normally, the temperature of the refrigerant in the closed housing is equal to or lower than a certain value, and the power supply to the electric motor is not interrupted by setting the operating temperature of the heat responsive body in the protector to a temperature slightly higher than this value. If the motor is restrained or overloaded during operation due to some abnormality, the winding temperature of the motor rises abnormally and the refrigerant temperature also rises. At this time, by detecting the rise in the refrigerant temperature, the thermal responsive element in the protector operates to open the contacts of the opening and closing mechanism, so that energization is reliably cut off before the winding of the electric motor is burned. Further, in the protection device of the present invention, most of the metal airtight container of the protector, particularly the metal container side is directly exposed to the flow of the refrigerant. Rapid thermal responsiveness can be ensured without sacrificing heat conduction to the thermal responsive body against a rise in temperature.

In the present invention, a protector having a flange having a portion substantially parallel to the peripheral edge of the lid plate is used. For example, there is another protector having a circular lid plate and a substantially cylindrical metal container. However, in such a cylindrical type, if a structure is adopted in which the flange around the cover plate of the protector is slid and attached as in the present invention, the substantial holding portion is small and the container can be rotated with respect to the central axis of the container. Therefore, the stability is poor and the connection terminal may be damaged. When the cylindrical metal container is held by the cluster socket, the stability is increased, but the connection terminal may be damaged because the container can still rotate 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 followability is deteriorated.

However, in the protection 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 to provide a metal container for the protector. Almost the entire metal container, which is thinner than the lid plate and is the main heat-sensitive part, is directly exposed to the flow of the refrigerant in the electric compressor As a result, the temperature change can be quickly transmitted to the internal thermal responsive body, and the thermal responsiveness is good.

In this embodiment, the protection device is described as an example in which the protection device is mounted on a sealed terminal provided near a refrigerant discharge pipe of a hermetically sealed electric compressor in a so-called high-pressure housing.
The protection device of the present invention may be attached to a so-called low-pressure housing hermetic electric compressor as long as a change in the refrigerant temperature due to a rise in coil temperature or the like at the time of abnormality can be reliably detected.

In addition, a two-pin type in which a connection terminal is fixed to two lead terminals insulated from a metal container as an internal protector has been described as an example. In addition, for example, one connection terminal is provided on a cover plate. Needless to say, a fixed one-pin type may be used, or a structure may be used in which a lead wire is directly fixed to a lead terminal on the connection side to the motor winding without a connection terminal.

[0019]

According to the protective device for a hermetic electric compressor of the present invention, it is possible to add a simple structure to the cluster socket and to take time and extra parts as in the conventional protective device. The internal protector can be easily and securely held, and even if the lead wire from the motor is pulled, the lead terminal and the connection terminal of the protector are not subjected to excessive force in the twisting direction, and the connection terminal may be deformed or deformed. A structure that prevents breakage can be provided.

Further, the protector is not limited to the shape shown in the drawing, but may be a member having a portion substantially parallel to the flange portion, and the protector may be held by the flange portion. In order to hold the protector as described above, the heat sensitive part is firmly held in a predetermined posture and location without covering the heat sensitive part, and the entire metal container serving as the main heat sensitive part is directly exposed to the flow of the refrigerant in the electric compressor. As a result, the temperature change can be quickly transmitted to the internal thermal responsive element, and the protection performance can be improved dramatically with good thermal responsiveness.

[Brief description of the drawings]

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

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

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

FIG. 4 is a perspective view of a cluster socket used in the protection device of FIG. 3;

FIG. 5 is a perspective view of an internal protector used in the protection device of FIG. 3;

FIG. 6 is a partial sectional view of the protection device of FIG. 3;

FIG. 7 is a side view of the protection device of FIG. 3 as 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 portion 12G: Protector holding portion 13: Internal protector 13A, 13B : Lead terminal 13C: Metal container 13D: Cover plate 13E: Flange part 14: Connection terminal 15: Tab terminal

Claims (1)

(57) [Claims] 1. A protection device attached to a hermetic terminal provided in a hermetic housing of a hermetic electric compressor and used in the hermetic housing, wherein an internal hermetic container is constituted by a metal container and a lid plate. It has a protector and a cluster socket made of an insulator, and the cover plate of the internal protector has a flange portion having a portion substantially parallel to a peripheral portion, and the cover plate or the lead terminal of the internal protector has A metal connection terminal is conductively connected and fixed, a connection terminal insertion portion and a protector holding portion are provided in the cluster socket, and the protector holding portion has a structure for holding the flange portion of the internal protector from both sides. Insert the connection terminal of the internal protector into the insertion part of the cluster socket, and connect the flange part to the protector. Slide the slides into the holders at the same time to the predetermined positions, and hold almost all of the metal container of the protector facing away from the cluster socket, so that most of the heat-sensitive part of the internal protector is not covered by the cluster socket. A protection device for a hermetic electric compressor, wherein the device is exposed to a refrigerant in a housing of the electric compressor.