GB2055496A - Compressor circuit of a vehicle- mounted air conditioner - Google Patents

Compressor circuit of a vehicle- mounted air conditioner Download PDF

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Publication number
GB2055496A
GB2055496A GB8019561A GB8019561A GB2055496A GB 2055496 A GB2055496 A GB 2055496A GB 8019561 A GB8019561 A GB 8019561A GB 8019561 A GB8019561 A GB 8019561A GB 2055496 A GB2055496 A GB 2055496A
Authority
GB
United Kingdom
Prior art keywords
compressor
switch
air conditioner
relay
fuse
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8019561A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Publication of GB2055496A publication Critical patent/GB2055496A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/275—Control of temperature characterised by the use of electric means with sensing element expanding, contracting, or fusing in response to changes of temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
    • B60H1/00—Heating, cooling or ventilating [HVAC] devices
    • B60H1/32—Cooling devices
    • B60H1/3204—Cooling devices using compression
    • B60H1/3225—Cooling devices using compression characterised by safety arrangements, e.g. compressor anti-seizure means or by signalling devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/10—Other safety measures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D43/00—Automatic clutches
    • F16D43/02—Automatic clutches actuated entirely mechanically
    • F16D43/25—Automatic clutches actuated entirely mechanically controlled by thermo-responsive elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D48/00—External control of clutches
    • F16D48/06—Control by electric or electronic means, e.g. of fluid pressure
    • F16D48/064—Control of electrically or electromagnetically actuated clutches
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/005—Arrangement or mounting of control or safety devices of safety devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/10—System to be controlled
    • F16D2500/102—Actuator
    • F16D2500/1021—Electrical type
    • F16D2500/1022—Electromagnet
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/10—System to be controlled
    • F16D2500/104—Clutch
    • F16D2500/10406—Clutch position
    • F16D2500/10418—Accessory clutch, e.g. cooling fan, air conditioning
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/30—Signal inputs
    • F16D2500/316—Other signal inputs not covered by the groups above
    • F16D2500/3168—Temperature detection of any component of the control system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/50—Problem to be solved by the control system
    • F16D2500/51—Relating safety
    • F16D2500/5108—Failure diagnosis
    • F16D2500/511—Leak detection
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/50—Problem to be solved by the control system
    • F16D2500/51—Relating safety
    • F16D2500/5114—Failsafe
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/70—Details about the implementation of the control system
    • F16D2500/704—Output parameters from the control unit; Target parameters to be controlled
    • F16D2500/70402—Actuator parameters
    • F16D2500/7041—Position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/22—Preventing, detecting or repairing leaks of refrigeration fluids
    • F25B2500/222—Detecting refrigerant leaks

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Thermal Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Electromagnetism (AREA)
  • Fluid Mechanics (AREA)
  • Air-Conditioning For Vehicles (AREA)
  • Control Of Positive-Displacement Pumps (AREA)

Abstract

A compressor circuit of an air conditioner wherein an electro- magnetic clutch (5) of the compressor is disengaged when the refrigerant leaks. A fuse (8) is connected with a relay coil (6b) for a relay switch (6a) that controls a power circuit for engagement of the electro-magnetic clutch. A detector switch (7) is further provided in series with the fuse and detects the abnormal condition of the system. When the detector switch closes, the fuse is blown to stop operation of the compressor. <IMAGE>

Description

SPECIFICATION Compressor circuit of a vehicle-mounted air conditioner The present invention relates to a compressor circuit of an air conditioner, and more particularly to a compressor circuit for an automobile by which an electro-magnetic clutch of the compressor disengaged when the amount of the refrigerant gas reduces.
An air conditioner for an automobile has a compressor driven by an engine via an electromagnetic clutch that is operatively disposed between the compressor shaft and a pulley assembly which is continually driven by the engine.
According to the invention, there is provided a compressor circuit of an air conditioner having a compressor comprising: a source of electric power; a relay switch; an electro-magnetic clutch of the compressor, the electro-magnetic clutch being connected in series with said relay switch with respect to said source of electric power; a detector switch which closes upon detection of a reduction in refrigerant in the air conditioner; a fuse connected in series with the detector switch with respect to said source of electric power; and a relay coil for actuation of the relay switch, the relay coil being connected in parallel with the detector switch with respect to the source of electric power.
An object of the invention is therefore to provide a compressor circuit of an air conditioner in which an electromagnetic clutch is disengaged upon detection of a reduction in refrigerant in the air conditioner to prevent the compressor from seizing-up.
In the accompanying drawings:- Fig. 1 is a circuit diagram of a prior compressor circuit of an air conditioner; and Fig. 2 is a circuit diagram of a compressor circuit of an air conditioner according to the present invention.
Before entering into the discussion of the invention, reference is first made to Fig. 1 to clarify a problem, encountered heretofore, which has been solved by the invention.
Referring to Fig. 1, a prior compressor circuit of an air conditioner for an automobile is shown wherein there is provided a source of electric power 1. A main switch 2 such as an ignition switch, an air conditioner switch 4, a temperature setting switch 3 and an electro-magnetic clutch 5 are connected in series with respect to the source of electric power 1. When all of the switches 2, 4 and 3 are closed, electric current passes through the electromagnetic clutch 5, causing the clutch to engage, transmitting the driving force of the engine to drive the compressor (not shown). Then, the compressor begins to compress the refrigerant in the heat cycle. The refrigerant is then condensed to a liquid form and transmitted to an evaporator in the heat cycle, thereby issuing cool air into a vehicle compartment.When the temperature in the compartment falls to a predetermined value, the temperature setting switch 3 opens, preventing a further reduction in temperature, and subsequently, when the temperature in the compartment rises again to a predetermined value, the temperature setting switch 3 closes again to cause a shift to a cooling mode operation. The setting of the temperature value can be variably adjusted by the temperature setting switch 3. It may be preferable for the air conditioner switch 4 to be kept open during the winter season to stop or prevent operation of the compressor to relieve the engine of the load by the compressor.
In the case of a compressor controlled by this prior compressor circuit, since refrigerant circulates through a heat cycle along with lubricant oil to prevent seizure of the compressor, leakage of refrigerant, if it occurs, will stop lubrication, causing seizure of the compressor.
With the prior compressor circuit, the compressor is likely to operate even if refrigerant has leaked with the lubricant oil, resulting in insufficient lubrication of the parts of the compressor. This is derived from the fact that the temperature setting switch 3 remains closed when detecting a rise in temperature in the vehicle compartment as a result of reduction in the cooling power af the air conditioner owing to the leakage of the refrigerant.
The object of the present invention, based on the recognition of the above-mentioned problem, is to provide a compressor circuit of an air conditioner in which a fuse is connected to a switch which detects abnormal rise in temperature of the compressor or abnormal drop in pressure of the refrigerant so as to allow burnout of the fuse when such abnormal condition is detected, cutting off the supply of current to an electro-magnetic clutch of the compressor.
Referring to Fig. 2, an embodiment of the present invention will now be described. There is shown a compressor circuit in Fig. 2. The same reference numerals as used in Fig. 1 are used here to designate equivalent elements. A relay 6 comprises a relay switch 6a and a relay coil Sb for controlling the activation of the compressor, wherein the relay switch 6a is connected in series with a temperature setting switch 3 and an electro-magnetic clutch 5. One terminal of the relay coil 6b is connected to the temperature setting switch 3 and the other terminal of the relay coil 6b is connected through a fuse 8 to earth. A main switch 2 and an air conditioner switch 4 are interposed between an electric power supply 1 and the temperature setting switch 3.
Furthermore, to this relay coil Sb, a series circuit of a detector switch in the form of a temperature sensing switch 7 and a current-limit-resistor 9 is connected in parallel. The rating of the fuse 8 and the resistance of the resistor 9 are selected such that normal current through the relay coil Sb does not blow the fuse 8, but the fuse 8 is blown by abnormal current passing therethrough when the temperature sensing switch 7 closes.
The operation of the above circuit will now be explained. The operation is initiated by closure of the main switch 2, an air conditioner switch 4 and the temperature setting switch 3. Then, a current is permitted to flow through these switches 2, 4, 3, to the relay coil 6b and the fuse 8, causing the relay switch 6a to close. This permits current to pass through the electro-magnetic clutch 5, putting the compressor into its cooling operation.
As far as the air conditioner operates normally, the actuation of the compressor is controlled by the turning on and turning off of the temperature setting switch 3 to maintain the compartment temperature within the predetermined range. If the refrigerant leaks from the heat cycle, the temperature of the compressor rises because of the heat produced by the friction. When the temperature rises to a predetermined value, the temperature rise of the compressor is detected by the temperature sensing switch 7. More specifically, when the temperature of the compressor rises to a predetermined value, the temperature sensing switch 7 closes, thereby closing the series circuit of the temperature sensing switch 7 and the resistor 9. As a result, the fuse 8 is blown by the Joule heat produced by the current flowing through it.Then, the current through the relay coil 6b is cut off, causing the relay switch 6a to open, and cutting off the current supply to the electro-magnetic clutch 5.
Consequently, the compressor ceases to operate, thus damage to the compressor, which otherwise might have occurred, is avoided.
It should be noted that the detector switch 7 may take the form of a pressure switch which is closed upon detection of the leaking of the refrigerant. With such a pressure switch, the same effect as described above can be obtained for preventing the seizure of the compressor.
It will now be appreciated from the foregoing that, according to the present invention, the compressor is prevented from seizing-up by the use of a temperature sensing switch, a relay and a fuse since the electro-magnetic clutch is disengaged as a result of the blowing of the fuse when the temperature sensing switch senses the overheating of the compressor or when a pressure switch detects a drop in the pressure in the refrigerant.
It will further be appreciated that, the compressor circuit of the present invention is very simple and can be manufactured without any substantial cost increase.

Claims (4)

1. A compressor circuit of an air conditioner having a compressor comprising: a source of electric power; a relay switch; an electro-magnetic clutch of the compressor, said electro-magnetic clutch being connected in series with said relay switch with respect to said source of electric power; a detector switch which closes upon detection of a leakage of refrigerant in the air conditioner; a fuse connected in series with said detector switch with respect to said source of electric power; and a relay coil for actuation of said relay switch, said relay coil being connected in parallel with said detector switch with respect to said source of electric power.
2. A compressor circuit as claimed in Claim 1, -wherein said detector switch is in the form of a pressure switch which closes upon detection of a drop in pressure in the refrigerant.
3. A compressor circuit as claimed in Claim 1, wherein said detector switch is in the form of a temperature sensing switch which closes upon detection of a rise in temperature of the compressor.
4. A compressor circuit constructed and arranged substantially as described herein with reference to and illustrated in Fig. 2 of the accompanying drawings.
GB8019561A 1979-06-15 1980-06-16 Compressor circuit of a vehicle- mounted air conditioner Withdrawn GB2055496A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1979082417U JPS56314U (en) 1979-06-15 1979-06-15

Publications (1)

Publication Number Publication Date
GB2055496A true GB2055496A (en) 1981-03-04

Family

ID=13774007

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8019561A Withdrawn GB2055496A (en) 1979-06-15 1980-06-16 Compressor circuit of a vehicle- mounted air conditioner

Country Status (4)

Country Link
JP (1) JPS56314U (en)
DE (1) DE3022283A1 (en)
FR (1) FR2459428A1 (en)
GB (1) GB2055496A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0598121A1 (en) * 1992-06-12 1994-05-25 Kabushiki Kaisha Yunikura Power cutoff device in automobile
US5507152A (en) * 1990-12-17 1996-04-16 Kabushiki Kaisha Yunikara Power separating apparatus in automobile
EP2175135A1 (en) * 2007-07-31 2010-04-14 Ubukata Industries Co., Ltd Sealed electric compressor

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2823560B2 (en) * 1987-09-05 1998-11-11 サンデン株式会社 Compressor protector
DE4012841A1 (en) * 1990-04-23 1991-10-24 Behr Gmbh & Co Air conditioning or cooling system esp. for motor vehicle - has coolant level detector responding differently to liquid and gas
CN110864494B (en) * 2019-11-20 2021-06-15 合肥美菱物联科技有限公司 Variable frequency compressor control method and device and refrigerator

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2978879A (en) * 1958-06-30 1961-04-11 Gen Motors Corp Refrigerating apparatus
US3102677A (en) * 1959-09-17 1963-09-03 Smith Corp A O Safety circuit for compressor drive
US3695054A (en) * 1971-05-25 1972-10-03 Carrier Corp Control circuit for an air conditioning system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5507152A (en) * 1990-12-17 1996-04-16 Kabushiki Kaisha Yunikara Power separating apparatus in automobile
EP0598121A1 (en) * 1992-06-12 1994-05-25 Kabushiki Kaisha Yunikura Power cutoff device in automobile
EP0598121A4 (en) * 1992-06-12 1995-01-11 Yunikura Kk Power cutoff device in automobile.
EP2175135A1 (en) * 2007-07-31 2010-04-14 Ubukata Industries Co., Ltd Sealed electric compressor
EP2175135A4 (en) * 2007-07-31 2013-02-27 Ubukata Ind Co Ltd Sealed electric compressor

Also Published As

Publication number Publication date
JPS56314U (en) 1981-01-06
DE3022283A1 (en) 1980-12-18
FR2459428A1 (en) 1981-01-09

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)