JP4181340B2 - Compressor protection method and protection structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a protection method and a protection structure for a compressor to which an electromagnetic clutch is attached , which is suitable for use in an air conditioner or the like .
[0002]
[Prior art]
In general, a refrigeration circuit of an air conditioner is provided with a compressor to which an electromagnetic clutch is attached. And after a refrigerant | coolant is compressed within a compressor, this refrigerant | coolant is sent to a refrigerating circuit system. The compressor is operated and stopped by turning on and off the electromagnetic clutch. Also, when the compressor is stopped, more or less refrigerant remains in the compressor. However, if the compressor is stopped and left in a low temperature state for a long time, a large amount of liquid refrigerant may accumulate in the compressor (so-called liquid refrigerant stagnation occurs). In particular, in cold districts or in winter, the ambient temperature in the compressor is lowered, so that a liquid refrigerant stagnation phenomenon is likely to occur.
[0003]
If the temperature decreases or the liquid refrigerant stagnation occurs in the compressor, the sealing performance in the compressor may decrease. If the compressor is restarted in a state where a large amount of liquid refrigerant is present in the compressor, the liquid refrigerant is compressed (by so-called liquid compression), and excessive pressure is applied to each component in the compressor, causing damage to the compressor. There is a risk.
[0004]
Therefore, conventionally, the compressor is provided with means for detecting the temperature of the compressor (for example, a thermistor), a heater, and heater energization control means for energizing the heater (for example, band heater), and the compressor temperature is below a predetermined value. Measures are taken to prevent it from dropping. In JP-A-5-312158 and JP-A-9-119389, proposals have already been made to provide a relief passage having a relief valve in the compression chamber of the scroll compressor to prevent excessive pressure rise in the compression chamber. ing.
[0005]
[Problems to be solved by the invention]
However, in the method of mounting a band heater or the like on the compressor, it is necessary to mount a dedicated heater, which may cause a decrease in productivity and an increase in cost.
[0006]
On the other hand, since the structure is complicated in the method of mounting the relief valve, there is a possibility that the productivity, the cost and the performance may be lowered similarly. Moreover, there is a possibility that the pressure reducing effect in the compressor cannot be sufficiently obtained. Furthermore, it may not be easily applicable to existing compressors.
[0007]
An object of the present invention is to prevent a decrease in the reliability of the compressor while preventing a decrease in productivity, an increase in cost, and a decrease in performance, and also protects the compressor by preventing liquid compression, and further It is an object of the present invention to provide a compressor protection method and a protection structure that can be easily applied to other compressors.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the compressor protection method of the present invention is such that when the compressor temperature is below a predetermined temperature when the compressor to which the electromagnetic clutch is attached is stopped, the core of the electromagnetic clutch is energized as a heater. The method is characterized in that the compressor is heated to raise the temperature of the compressor to a predetermined temperature or higher.
[0009]
Further, in order to solve the above problems, the compressor protection structure of the present invention has a means for detecting the temperature in the compressor to which the electromagnetic clutch is attached, and when the detected temperature becomes a predetermined value or less, Core energization control means for energizing the core of the electromagnetic clutch to function as a heater for heating the compressor is provided.
[0010]
It is preferable to arrange a heat transfer member from the core to the compressor body at the joint between the core of the electromagnetic clutch and the compressor body. The heat transfer member can be arbitrarily selected from materials having high heat transfer properties. For example, a metal, resin, etc. can be mentioned.
[0011]
In the compressor protection method and structure as described above, the compressor temperature detected by the means for detecting the compressor temperature (for example, the internal temperature of the compressor body) when the compressor is stopped is determined in advance. When the temperature is lower than the predetermined temperature, the core energization control means energizes the core of the electromagnetic clutch, the core is heated, and the heat rises as the heat is transferred to the compressor side. That is, when the compressor temperature decreases and the liquid refrigerant accumulates, the core of the electromagnetic clutch functions as a heater so that the compressor temperature is raised to a predetermined temperature or more, so that the liquid refrigerant is prevented from accumulating. So-called liquid compression is prevented during restart, and the compressor can be reliably protected.
[0012]
Further, the compressor protecting method as described above includes a means for detecting the temperature of the compressor, and when the detected temperature falls below a predetermined temperature, the core of the electromagnetic clutch is energized and the core It can be implemented using a protective structure provided with a core energization control means that functions as a heater. In other words, as a means for detecting the temperature while providing a function as a heater to the core of the electromagnetic clutch and detecting the temperature, a means for detecting the temperature used in a conventional band heater of a compressor, etc. In addition, since the heater energization control means of the conventional compressor can be used as the core energization control means as it is, an increase in the number of parts can be prevented, and a decrease in productivity and an increase in cost can be prevented. In addition, the present invention can be easily applied to an existing compressor only by making a simple modification.
[0013]
In the compressor protective structure, it is necessary to efficiently transfer heat from the core of the electromagnetic clutch functioning as a heater to the compressor body. Therefore, it is preferable to arrange a heat transfer member between the core and the compressor body. That is, when the joint surface between the core and the compressor body is microscopically observed, the actual contact area is small because the joint surface between the core and the compressor body is not formed on a completely flat surface. For this reason, since an actual contact area can be expanded if a heat-transfer member is arrange | positioned between both contact surfaces, the heat-transfer efficiency from a heater to a compressor main body can be improved. A metal can be used as the heat transfer member. Further, even if a resin is used, the actual contact area can be expanded. Therefore, a resin (for example, silicon rubber) can be used for the heat transfer member.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a compressor protective structure of the present invention will be described with reference to the drawings.
1 and 2 show a compressor (a scroll compressor) having a protective structure according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a scroll type compressor. The compressor 1 has a front housing 2 and a casing 3.
[0015]
A drive shaft 5 is rotatably inserted into the front housing 2 via bearings 4a and 4b. A crank mechanism 6 is provided at one end of the drive shaft 5, and a crank pin 6 a of the crank mechanism 6 is inserted into an eccentric bush 7 provided at a position eccentric from the rotation center (axial center) of the drive shaft 5. Has been.
[0016]
The eccentric bush 7 is rotatably inserted into the inner ring of the drive bearing 9 fixed (press-fitted) into the annular protrusion 8 of the movable scroll 10.
[0017]
The movable scroll 10 includes a bottom plate 11 and a spiral body 12 fixed to the bottom plate 11. A groove 14 extending along the spiral shape of the spiral body 12 is formed on the tip surface 13 of the spiral body 12, that is, the surface facing the bottom plate 17 of the fixed scroll. A chip seal 15 is fitted as a seal member.
[0018]
The spiral body 12 of the movable scroll 10 is engaged with the spiral body 18 of the fixed scroll 16 at an angle. The fixed scroll 16 has a bottom plate 17 and a spiral body 18, and the spiral body 18 is fixed to the bottom plate 17. A groove 20 extending along the spiral shape of the spiral body 18 is formed on the front end surface 19 of the spiral body 18 facing the bottom plate 11 of the movable scroll, and a chip seal 21 is fitted in the groove 20. Has been.
[0019]
The bottom plate 17 of the fixed scroll 16 has a discharge hole 23 communicating with the discharge chamber 22. A discharge valve 24 is provided in the discharge hole 23, and the lift amount of the discharge valve 24 abuts on the retainer 25 and is regulated.
[0020]
An electromagnetic clutch 26 is attached to the front end portion 28 of the front housing 2 of the compressor 1 via a bearing 29. The electromagnetic clutch 26 has a core 31 having a coil portion 30 formed therein. The core 31 has a core cover 32 and a plate 33 fixed to the cover 32.
[0021]
The compressor 1 is provided with a thermistor 34 as means for detecting the temperature inside the compressor. The thermistor 34 is electrically connected to the core energization control means 35. When the temperature detected by the thermistor 34 becomes a predetermined value or lower (for example, −10 ° C. or lower), the core 31 is energized by the core energization control means 35. The core energization control means 35 and the core 31 are connected by a lead wire 36.
[0022]
The plate 33 of the core 31 is in contact with the housing 2 of the compressor 1. A heat transfer member 37 is provided between the joint surface of the plate 33 and the housing 2 as shown in FIG. Resin (for example, silicon rubber) or metal can be used for the heat transfer member 37. When the joint surface between the plate 33 and the housing 2 is viewed microscopically, there are innumerable minute irregularities as shown in FIG. For this reason, although an actual contact area becomes small, the actual contact area can be sufficiently ensured by interposing the heat transfer member 37.
[0023]
Then, when the core 31 is heated by being energized by the core energization control means 35, the heat is transferred to the housing 2 through the plate 33 and the heat transfer member 37, and the temperature inside the compressor is raised. . That is, in the present embodiment, the core portion 31 functions as a compressor heating heater. When the temperature inside the compressor is raised to a predetermined temperature or higher, the temperature rise is detected by the thermistor 34, and energization by the core energization control means 35 is stopped.
[0024]
In the compressor according to this embodiment, for example, a driving force from a driving source (not shown) such as an engine or a driving motor is transmitted to the driving shaft 5 via the clutch mechanism 26. Further, the eccentric bush 7 is rotated by the crank pin 6 a of the crank mechanism 6, and a turning motion is given to the movable scroll 10 whose rotation is prevented by the ball coupling 27.
[0025]
The refrigerant sucked into the compressor 1 from the suction port (not shown) is taken into the spiral body from the gaps at the distal ends of the spiral bodies 12 and 18. Then, the fluid pocket formed with the orbiting movement of the movable scroll 10 is moved toward the central portion while reducing the capacity thereof, and the compressed fluid is discharged from the discharge hole 23 into the discharge chamber 22, and a discharge port (illustrated). (Omitted) is sent to the outside of the compressor.
[0026]
By the way, when the compressor 1 stops, more or less refrigerant remains in the compressor. Especially in cold districts where the outside air temperature is low and in winter, liquid refrigerant tends to accumulate inside the compressor. Thus, when the operation of the compressor 1 is resumed in a state where a large amount of liquid refrigerant is present inside the compressor, liquid compression occurs and internal members of the compressor 1 (for example, spiral bodies 12, 18, the bottom plate 11, 17) or the like, and an internal member of the compressor 1 may be damaged sometimes.
[0027]
However, in this embodiment, when the compressor temperature (in this embodiment, the internal temperature of the compressor 1) is equal to or lower than a predetermined temperature (−10 ° C. in this embodiment) when the compressor is stopped. The core energization control means 35 energizes the core 31 of the electromagnetic clutch 26 and the core 31 is heated. Further, this heat is transferred to the housing 2 through the plate 33 and the heat transfer member 37. As the housing 2 is heated, the compressor temperature is raised. Therefore, accumulation of liquid refrigerant is prevented and the amount of liquid refrigerant in the compressor can be reduced, so that liquid compression is prevented and the internal members of the compressor 1 can be reliably protected.
[0028]
Further, the thermistor 34 that detects the temperature of the compressor 1 can be used as it is as a conventional thermistor band heater of the compressor. Further, the heater energization control means of the conventional compressor can be used as the core energization control means 35 as it is. Therefore, an increase in the number of parts can be prevented, and a decrease in productivity and an increase in cost can be prevented. Further, the protection mechanism of the compressor of the present invention can be easily applied only by making a simple improvement to the existing compressor.
[0029]
Further, since the heat transfer member 34 is disposed between the plate 33 of the core 31 and the housing 2, the actual contact area between the two can be increased. Therefore, the heat transfer efficiency from the core 31 side to the housing 2 side can be improved, and the temperature raising efficiency of the compressor 1 can be improved.
[0030]
In this embodiment, the internal temperature of the compressor 1 is detected by the thermistor 34 and the core 31 is energized by the core energization control means 35 based on the detected temperature. You may make it carry out energization control based on the signal of the sensor which detects distribution. It is also possible to control energization by a combination of a temperature switch and a timer.
[0031]
【The invention's effect】
As described above, according to the compressor protection method and protection structure of the present invention, it is possible to prevent an increase in the number of components, a decrease in productivity, and an increase in cost while preventing an increase in liquid refrigerant accumulated in the compressor. In addition to preventing a decrease in sealing performance, liquid compression is prevented when the compressor is restarted, and the compressor can be effectively protected.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a scroll compressor provided with a protective structure according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view showing a contact state between a core of an electromagnetic clutch and a housing of a compressor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2 Front housing 3 Casing 4a, 4b Bearing 5 Drive shaft 6 Crank mechanism 6a Crank pin 7 Eccentric bush 8 Annular projection 9 Drive bearing 10 Movable scroll 11 Bottom plate 12 Spiral wound body 13 End face 14 Groove 15 Chip seal 16 Fixed scroll 17 Bottom plate 18 Spiral wound body 19 Front end surface 20 Groove 21 Chip seal 22 Discharge chamber 23 Discharge hole 24 Discharge valve 25 Retainer 26 Electromagnetic clutch 27 Ball coupling 28 Front end portion 29 Bearing 30 Coil portion 31 Core 32 Core cover 33 Plate 34 Thermistor 35 Core energization control means 36 Reed wire 37 Heat transfer member

Claims (3)

When the compressor to which the electromagnetic clutch is attached is stopped, if the compressor temperature falls below a predetermined temperature, the electromagnetic clutch core is energized to function as a heater, and the compressor is heated to a predetermined temperature or higher. How to protect the compressor. Means for detecting the temperature of the compressor to which the electromagnetic clutch is attached, and a core energization control for energizing the core of the electromagnetic clutch to function as a heater for heating the compressor when the detected temperature falls below a predetermined value And a protective structure for the compressor. The protective structure according to claim 2, wherein a heat transfer member from the core to the compressor main body is disposed at a joint portion between the core and the compressor main body.

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