JP3368710B2 - Mounting mechanism of thermo-responsive element - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for mounting a heat responsive element to a compressor and a method therefor. For example, in a refrigerant compressor mounted on an automobile, the temperature of discharged refrigerant is sensed and the power to the compressor is detected. The present invention relates to mounting of a thermal responsive element that outputs a signal for turning on and off an electromagnetic clutch for transmission.

[0002]

2. Description of the Related Art Conventionally, for mounting a heat responsive element to this type of equipment, for example, Japanese Utility Model Laid-Open No. 57-124942.
Known are those disclosed in Japanese Patent Laid-Open Publication No. Hei 2-135640 and the like.

In Japanese Utility Model Laid-Open No. 57-124942, there is described a protective switch body which is hermetically attached to a through hole provided in a container of a refrigerant compressor.

In Japanese Unexamined Patent Publication No. 2-135640, a container of a compressor has a cover for a discharge refrigerant passage, and this cover also serves as a case for a heat responsive element, and a bimetal is formed in the recess. Parts such as the above are housed to form a thermoresponsive element.

In either of the above-mentioned conventional examples, the compressor container and the compressor cover are made of metal, for example, aluminum die-cast and have good thermal conductivity, so that the temperature of the discharged refrigerant is the heat-sensitive part of the protection switch. There were various reasons that were not accurately reflected in. That is, there is a problem that the temperature of the heat-sensitive part of the protection switch is taken by the container of the compressor, and particularly in a vehicle-mounted compressor, there is a great influence due to external temperature and external disturbances such as winds received during traveling.

In order to facilitate the assembly of the compressor, there are those in which both the discharge passage and the suction passage of the refrigerant are provided in the container itself, or both the discharge passage and the suction passage are integrally molded in the cover. In such a case, the heat on the discharge side is taken to the suction side through the container and the cover, so that it becomes more difficult to accurately detect the refrigerant temperature in the conventional mounting mechanism.

As a solution to these problems, Japanese Patent Application Laid-Open No. 6-257903 proposes a mounting mechanism for thermally insulating the heat responsive element from the cover of the compressor. This attachment mechanism will be described with reference to FIG.
Reference numeral 101 is a partial cross-sectional view showing the vicinity of a refrigerant discharge passage 102 and a suction passage 103 of a refrigerant compressor used for a car air conditioner or the like. The discharge passage 102 and the suction passage 103 are
It is composed of a compressor body 104 and a cover 105. A through hole 105 is provided on the discharge passage 102 side of the cover 105.
A is provided in the through hole 105A.
6 is attached and is airtightly held by a packing 106A such as an O-ring attached to the outer periphery of the plug body. Two lead terminal pins 107 are airtightly and electrically and thermally insulated and fixed to the plug body 106 by glass or the like, and a temperature sensitive element 108 connected inside the cover 105.
And the lead wire 109 connected to the outside are electrically connected. According to this attachment mechanism, the temperature sensitive element 108 is the plug body 1.
Since the cover 105 is thermally insulated from the cover 105, the heat received from the refrigerant is not taken away, and the refrigerant can be quickly overheated. The reason is that the lead terminal pin 107 fixed to the plug body 106 by a material having a low thermal conductivity such as glass is attached to the terminal 1 of the temperature sensitive element 108.
This is because 11 is fitted and fixed.

In the mounting mechanism disclosed in Japanese Patent Laid-Open No. 6-257903, after the plug 106 is mounted in the through hole 105A from the inner side of the cover 105, a metal fixing device 110 such as a C-shaped snap ring is mounted in the same direction. Through hole 1
The plug body 106 is fixed by being attached to the groove 105B provided in 05A. However, according to this fixing method, when the packing 106A crosses the groove when the plug body 106 is mounted, the corner of the groove may be damaged and the airtightness may be deteriorated. Further, in this case, it is necessary to remove the plug 106 and replace the packing 106A, but in this case, the fixing device 110 must be removed, and this removal work requires a dedicated tool in a limited space. It is very troublesome and troublesome.

Therefore, in the patent application dated February 3, 1995, the applicant of the present invention has a metal fixing device having a contact portion whose tip expands in a direction opposite to the mounting direction, and The inner wall is provided with a locking portion of the fixing device, and the locking portion has a taper portion on one side and an inverse taper portion on the other side with an intermediate portion having the largest inner diameter sandwiched therebetween, and the inverse taper portion is the fixing device. Of the abutment part of the fixing device is inserted in the reverse taper part of the locking part by inserting the fixing device into the through hole in the direction pushing the plug into the through hole. We proposed a mounting mechanism for a thermo-responsive element that attaches and holds a plug by abutting it. According to this mounting mechanism, the packing is not damaged at the time of mounting, and in particular, the sum of the angle of the reverse taper portion of the locking portion with respect to the inner wall of the through hole and the angle of the contact portion of the fixing device with respect to the inner wall of the through hole is 45 °. By making the angle less than 75 °, the stopper can be prevented from coming off in a normal state without using a fixture having rigidity as high as that of the conventional one.
By appropriately selecting the rigidity of the fixture, the plug can be removed by applying a predetermined force when necessary without using a special jig or the like.

[0010]

However, since the mounting mechanism uses a fixture made of metal, for example, iron or phosphor bronze, the through hole of the cover made of aluminum die-cast at the time of attachment / detachment thereof. There is a problem that the inner wall of the car may be slightly damaged. In addition, a tapered groove-shaped engaging portion must be provided in the through-hole of the cover in order to mount and hold the fixing device, which complicates processing of the cover.

[0011]

Therefore, in the mounting mechanism of the thermal actuator of the present invention, the discharge passage of the aluminum cover fixed to the container of the automobile refrigerant compressor and the outside of the compressor penetrate. In a case where a through hole is provided and the stopper is attached and held so as to hermetically close the through hole from the refrigerant passage side of the cover by a fixing device that does not move against a predetermined external force, the fixing device is at least a part thereof. Is made of an electrically insulating material having oil resistance and refrigerant resistance.

Another feature is that the fixing device is locked in the through hole by elasticity or fitting.

Another feature is that the electrically insulating material forming the fixing device is a resin such as engineering plastic.

Still another feature is that the fixing device covers at least the surface of the electrically insulative filler of the inner surface of the stopper of the compressor inside with the electrically insulative material.

[0015]

In the present invention, since the fixing device to be fitted into the through hole is made of resin, the plug body can be easily attached / detached, and at the time of attachment / detachment, the inner wall of the through hole is different from the conventional metal fixing device. It does not hurt. In addition, by covering the inner surface of the plug inside the compressor with a fixing device made of electrically insulating resin, it is possible to prevent conductive foreign substances from adhering to the surface of the electrically insulating filler of the plug sufficiently. A good insulation distance can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. A compressor 1 shown in FIG. 1 is a vehicle-mounted compressor used in a car air conditioner or the like, and FIG. 2 is a partially enlarged view of the compressor 1 near a mounting portion of a heat responsive element. The container 2 of the compressor 1 is configured to substantially cover the entire compression element 3, and is closed by a lid 2A in a state where a rotary shaft (not shown) of the compression element 3 is connected to an electromagnetic clutch described later. The pulley 4 is connected to an engine (not shown) by a belt or the like, and the compression element 3 receives the rotational force from the pulley 4 from the rotary shaft via the electromagnetic clutch 5 and is driven to compress the refrigerant.

The container 2 has an opening whose surface is substantially parallel to the axis of rotation of the compression element 3 described above, and a suction chamber 7A which forms a part of a refrigerant suction passage together with a cover 6 which abuts on this opening, and a discharge. A discharge chamber 7B forming a part of the passage is configured. The cover 6 is provided with a through hole 6A, and a plug body 9 is attached so as to close the through hole 6A, and the heat responsive element 8 is entirely discharged through the plug body 9 into the discharge chamber 7B. It is mounted so that it is exposed to the refrigerant passing through the chamber.

As the heat responsive element 8, for example, Japanese Patent Laid-Open No. 3-2
As shown in the perspective views from the front and the side in FIGS. 4 (A) and 4 (B), a sealed container 8 made of metal having high pressure resistance and good thermal conductivity is used.
A conductive terminal pins 14A and 14B are airtightly insulated and fixed from the container by an electrically insulative filling material such as glass, and each conductive terminal pin has a terminal 15
A and 15B are conductively fixed by a method such as welding.
The heat responsive element 8 receives the plug 9 through the terminals 15A and 15B.
Are attached to the tip ends of the lead terminal pins 11A and 11B on the discharge chamber side. By holding the heat responsive element 8 at the predetermined position in this way, when the cover 6 is attached to the container 2 by a predetermined method, the heat responsive element 8 does not come into direct contact with the cover 6 or the container 2, and the inside of the discharge chamber 7B is prevented. Is placed so that the whole is exposed to the refrigerant. Further, after the cover 6 is attached to the container 2, the lead terminal pins 11A and 11B of the plug body are
Lead wires 17A and 17B held by a connector 16 which is a waterproof means are attached to the. The lead wires 17A and 17B are connected to a controller of a compressor (not shown), and the electromagnetic clutch 5 and the like are controlled by a signal from the heat responsive element.

As described above, since the heat responsive element 8 does not come into direct contact with the cover 6 and the container 2,
The influence of heat from the container or the outside is suppressed to a minimum, and the entire heat responsive element 8 is directly exposed to the discharged refrigerant, so that a good heat exchange relationship with the refrigerant is obtained and accurate and responsive temperature detection is performed. It can be carried out.

This mounting mechanism will be described with reference to FIG.
Two through-holes are formed in the plug body 9 of the embodiment, and the lead-terminal pins 11A and 11B are hermetically sealed in each of the through-holes by a filling material 10 such as glass having an electrically insulating property and a low thermal conductivity. It is fixed. In this way, the lead terminal pins 11A and 11B of the plug 9 are filled with the filler 10 made of a material having low thermal conductivity.
Since it is fixed by, the influence of heat from the container or the outside through the conductive portion on the heat responsive element 8 can be further suppressed.

A groove 9A is provided in the peripheral portion of the stopper 9, and a packing 12 having sufficient heat resistance and refrigerant resistance, in the case of the embodiment, a so-called O-ring is held. The plug body 9 having the packing 12 attached thereto is attached to the through hole 6A penetrating the discharge chamber 7B of the cover 6 and the outside of the compressor from the discharge chamber side. In this embodiment, the inner wall of the through hole is not provided with a locking portion, but in order to more securely hold the fixing device 13 described later, for example, as shown in FIG. 6, a groove-shaped locking portion 6C. May be provided. It should be noted that it is preferable that the locking portion 6C be a tapered groove so as not to damage the packing during mounting.

By fixing the fixing device 13 into the through hole 6A with the stopper 9 being applied to the shelf 6B, the stopper 9 is prevented from coming off and the packing 12 provides airtightness. Reserved. This fixture 13
Shows a plan view in FIG. 5 (A), and has a shape as shown in FIG. 5 (B) in the direction of arrow AA, and is an electrically insulating material excellent in oil / refrigerant resistance, for example, A plurality of convex contact portions 13A for locking are provided on the periphery of a substantially disk-shaped resin plate made of a resin such as so-called engineering plastic such as polyphenylene sulfide (PPS). In the embodiment, the slit 1 is formed inside the contact portion 13A.
3B is provided to provide a predetermined elasticity near the contact portion 13A. In addition, a stopper 9 is provided near the center of the fixture 13.
Through holes 13C, 1 for inserting lead terminal pins of
3D is provided.

The force required to attach and detach the plug 9 is determined by the dimensional relationship between the diameter of the through hole and the contact portion of the fixing device, and the elasticity or rigidity given to this contact portion. According to the experiment, in the embodiment, the plug 9 is inserted from the outside of the cover.
Since a force of about 5 kgf is applied when attaching the terminals to the lead terminal pins 11A and 11B, it must be set so as not to come off with a force less than this. It is also necessary to consider the force applied to the plug when decompressing the inside of the compressor for the airtight inspection, but in the case of the embodiment, the diameter is about 18 mm and it is less than 3 kgf, so it is set to withstand terminal installation. If no problem. This force can be adjusted by appropriately selecting the material and thickness of the fixing device. Of course, if necessary, the force for removing the stopper can be changed by changing the number of contact portions.

According to the present invention, the plug does not come off with a force as much as the attaching force of the terminal, and a predetermined force is applied when necessary without using a special jig. Can be removed, and furthermore, no metal scrap is generated by attaching the fixing device.

Even if a metal fixing device is used as in the prior art, it is possible to remove the fixing device and the plug body by applying a force in the opposite direction to the mounting as in the present invention. However, especially when the locking part is not provided in the through hole, if the rigidity of the fixing device is increased so that the plug does not fall off during normal operation, the fixing device is made of metal and has high hardness, so it will come into contact with each other during mounting and removal. The part scrapes the inner wall of the through hole, and the metal scraps generated at this time may enter the compressor and damage the inside, or in the worst case, restrict the motion of the compressor.

In contrast, the present invention covers the fixing device 6
Since the resin is molded with a resin having a hardness lower than that of the metal used in the above, it is possible to obtain sufficient holding strength without cutting the inside of the through hole at the time of attachment and detachment. Therefore, metal scraps are not generated or mixed in the compressor.

In such a compressor, it is difficult to completely eliminate the conductive foreign matter such as metal powder smaller than the above-mentioned metal scraps generated by the assembling work or the pipe connecting work from remaining inside. Is. For example, even if the foreign matter is not large enough to restrain the compressor, if it adheres to the surface of the filling material 10 of the plug 9, the insulation distance between the metal plate of the plug and the lead terminal pin becomes small. Therefore, there is a possibility that insulation failure may occur and control by the thermoresponsive element may become impossible.

However, since the fixing device 13 of the embodiment is an electrical insulator and covers the inside of the plug body 9, conductive foreign matter such as metal powder remains in the compressor for some reason. However, it does not adhere to the surface of the filler.

In the above-described embodiment, the plug 9 is covered with the cover 6.
Although the fixing tool is inserted after being inserted into the through hole 6A, the plug 9 and the fixing tool 13 may be inserted into the through hole 6A at the same time. Further, the fixing device 13 is attached to the plug body 9 in advance, and the lead terminal pin 11 of the plug body is attached.
By attaching the terminals 15A and 15B of the thermal responsive element 8 to A and 11B, the plug 9, the fixture 13 and the thermal responsive element 8 can be integrally handled, and the plug 9 to the through hole 6A can be easily handled. Since the fixing device 13 and the fixing device 13 can be inserted at the same time, workability is further improved.

The fixture is not limited to the shape shown in FIG. 5, but the attachment strength can be adjusted by changing the number of slits or abutting portions, for example. That is, the attachment strength may be selected to an appropriate value by providing the abutting portion 23A at the tip of the cantilever 23B like the fixing device 23 shown in FIG. 7. Further, although not shown, the slit is eliminated. As the shape, the attachment strength may be selected as an appropriate value depending on the dimensional relationship between the inner diameter of the through hole 6A and the contact portion.

Further, in the above-described embodiment, the fixing device formed of an electrically insulating material such as resin has been described as an example, but in addition to this, the fixing device 3 shown in FIGS. 8A and 8B.
The elastic portion 33B is provided on the metal base portion 33A as shown in FIG.
At least the contact portion 33C at the tip of the elastic portion that contacts the inside of the through hole 6A may be made of an electrically insulating material such as resin. Further, even in the case where the fixing device 43 shown in FIGS. 8C and 8D has the metallic elastic portion 43A and the electrically insulating abutting portion 43B, the shield 43C made of the electrically insulating material is used. By adopting a structure that covers the surface of the electrically insulating filler of the plug body, it is possible to prevent the conductive foreign matter from adhering to the surface of the filler.

[0032]

As described above, according to the present invention, the fixing device to be fitted into the through hole is made of an electrically insulating material having a low thermal conductivity and a hardness lower than that of the cover 6, so that the fixing device is attached to the inner wall of the through hole. The structure may be such that the engaging portion is fixed to the through hole only by the strength of the fitting without providing the engaging portion, and the inner wall of the through hole is not scratched unlike the conventional metal fixing device. Further, since the fixing device has a structure in which the surface of the electrically insulating filler of the plug is covered, conductive foreign matter does not adhere to the surface of the filler, and it is possible to prevent uncontrollability due to poor insulation.

Further, in the present invention, the structure is such that the plug body is attached to the cover and the thermoresponsive element is attached to the lead terminal pin by the terminal. Therefore, even if the plug body or the thermoresponsive element is inconvenient, only the cover portion is provided. It can be replaced with a good product relatively easily by removing. Furthermore, by appropriately setting the attachment strength of the fixing device, the stopper can be prevented from coming off in a normal state, and a predetermined force is applied when necessary, without using a special jig or the like. Can be removed.

Further, by attaching the plug body to the cover from the discharge chamber side, it is possible to make the structure sufficiently resistant to the pressure rise in the discharge chamber, and it is possible to easily obtain the sealed structure only by fitting. Further, since the heat-responsive element of the airtight metal container with high pressure resistance is directly arranged in the discharge refrigerant passage, the temperature of the refrigerant can be detected quickly and accurately, and the compressor can be used for the heat-responsive element. Since it is placed so that there is almost no effect of heat from the container or cover, the refrigerant temperature can be reliably detected even in the case where the discharge passage and the suction passage are integrally molded, and the mounting of the fixing device is easy. It is possible to achieve both reliable holding of the stopper.

Further, according to the present invention, since the fixing device and the heat responsive element are attached to the plug body in advance, they can be handled as a unit, so that the plug body and the fixing device can be easily handled, and the heat Workability at the time of attaching the response element to the compressor is improved.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of a compressor to which a heat responsive element is attached according to the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of a mounting mechanism for a thermoresponsive element according to the present invention.

FIG. 3 is a development view of a mounting mechanism of the thermoresponsive element shown in FIG.

FIG. 4 is a perspective view of a thermoresponsive element mounted according to the present invention.

5 is an example of a fixing device used in the mounting mechanism of the thermoresponsive element of FIG.

FIG. 6 is a sectional view showing another embodiment of the mounting mechanism of the thermoresponsive element of the present invention.

FIG. 7 is another embodiment of the fixture used in the mounting mechanism of the thermoresponsive element of the present invention.

FIG. 8 is another embodiment of the fixture used in the mounting mechanism of the thermoresponsive element of the present invention.

FIG. 9 is a partial cross-sectional view of a compressor showing a conventional heat-responsive element mounting mechanism.

[Explanation of symbols]

1: Compressor 2: Container 5: Electromagnetic clutch 6: Cover 6A: Through hole 7A: Inhalation chamber 7B: Discharge chamber 8: Thermal response element 8A: Airtight container 9: Plug 9A: groove 10: Filler 11A, 11B: Lead terminal pin 12: Packing 13, 23: Fixture 13A, 23A: contact part 13B: slit 13C, 13D: Through hole 14A, 14B: Conductive terminal pin 15A, 15B: Terminal 33, 43: Fixing device 33A: Base 33B, 43A: Elastic part 33C, 43B: abutting part 43C: Shield

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F25B 49/02 510

Claims (5)

(57) [Claims] 1. A refrigerant discharge passage and a suction passage are formed in a cover fixed to a container of an automobile refrigerant compressor, and a through hole penetrating the discharge passage of the cover and the outside of the compressor is provided,
The stopper is attached and held by a fixing device that does not move against a predetermined external force from the refrigerant passage side of the cover so as to hermetically close the through hole, and electrically conductive lead terminal pins are electrically insulated from this stopper. Air-tightly fixed with a conductive filler, and the heat-responsive element having a metal container with airtightness and pressure resistance at the tip of the lead terminal pin protruding into the discharge-side refrigerant passage does not heat the cover and the container. Are attached so as to be electrically insulated and have a good heat exchange relationship with the discharged refrigerant, and a lead wire connected to the controller of the compressor is attached to the side of the lead terminal pin protruding to the outside of the compressor. In this structure, the fixing device is at least partially formed of an electrically insulating material having oil and refrigerant resistance, and a mounting mechanism for a thermal responsive element. 2. The mounting mechanism for a thermoresponsive element according to claim 1, wherein the fixing device is elastically locked in the through hole. 3. The mounting mechanism for a thermoresponsive element according to claim 1, wherein the fixing device is locked in the through hole by fitting. 4. The mounting mechanism for a thermoresponsive element according to claim 1, wherein the electrically insulating material forming the fixing device is a resin. 5. The heat responsive element according to claim 1, wherein the fixing device is configured such that at least the surface of the electrically insulative filler of the inner surface of the stopper of the compressor is covered with the electrically insulative material. Mounting mechanism.