JP2007120332A - Oil film formation failure detecting method of swash plate type compressor and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil film formation failure detecting method of a swash plate type compressor and its device, capable of accurately detecting formation failure of an oil film when operating the compressor, capable coping even with various operation conditions, and also capable of detecting the formation failure without having influence on performance of the compressor. <P>SOLUTION: This swash plate type compressor is provided with a first conductive means electrically continued with a shoe 22 of a piston 20 and a second conductive means electrically continued with a swash plate 30. Since the formation failure of the coil film between the shoe 22 and the swash plate 30 is detected by measuring a voltage value of a voltage impressing circuit 54 by a voltage measuring apparatus 55 by impressing voltage of the predetermined size from an external part on the respective shoes 22 and the swash plate 30 by the voltage impressing circuit 54, the formation failure of the oil film can be surely detected by a simple structure without requiring to arrange precision mechanical equipment such as a sensor, a camera or a transmitter inside a compressor body 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an oil film formation defect detection method and apparatus for a swash plate compressor used in a refrigerant circuit of a vehicle air conditioner, for example.

  In general, this type of swash plate compressor includes a plurality of cylinders that are circumferentially spaced apart from each other in the compressor body, a plurality of pistons that reciprocate in each cylinder, and one end of each piston. A swash plate that is slidably engaged with the swash plate, and a drive shaft that rotates the swash plate. One end of each piston is slidable on the swash plate via a pair of shoes facing each other. What was made to contact is known (for example, refer patent document 1).

Further, in the compressor, an oil film of lubricating oil is formed between each shoe and the swash plate. However, since the shoe and the swash plate slide at a high speed, the lubrication conditions are severe and the oil film is cut off. There is a problem that seizure between metals tends to occur. Therefore, in order to detect the formation failure of the oil film between the shoe and the swash plate, a method of measuring the clearance with the shoe by embedding a sensor in the swash plate, a method of directly monitoring the sliding portion with a high speed camera, A method has been proposed in which an optical signal or a radio signal is output and detected externally when the shoe and the swash plate come into contact with each other.
Japanese Utility Model Publication No. 4-125682

  However, in each of the detection methods, a precision device such as a sensor, a camera, or a transmitter is installed inside the compressor, so that it can be accurately detected when the compressor is in operation, or it corresponds to various operating conditions. There have been various problems in practical use, such as whether the detection can be performed without affecting the performance of the compressor.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to accurately detect the formation of an oil film during operation of the compressor and to cope with various operating conditions. Furthermore, another object of the present invention is to provide a method and apparatus for detecting an oil film formation failure of a swash plate compressor that can detect without affecting the performance of the compressor.

  In order to achieve the above object, the present invention provides a plurality of cylinders that are circumferentially spaced apart from each other in the compressor body, pistons that reciprocate in the cylinders, and slidable on one end side of the pistons. A swash plate type that includes a swash plate that engages with the swash plate and a drive shaft that rotates the swash plate, and one end of the piston is slidably engaged with the swash plate via a pair of shoes facing each other. In the method of detecting an oil film formation failure of a compressor, a voltage of a predetermined constant voltage power source is applied from the outside to a conductive means connected to the shoe and swash plate of the piston by a voltage application circuit, and the voltage value of the voltage application circuit is Measurement is performed to determine whether or not the value of the measured voltage is equal to or greater than a predetermined reference value.

  As a result, when the power supply voltage of the voltage application circuit is applied to the shoe and the swash plate, the gap due to the oil film between the shoe and the swash plate becomes an electrical resistance, and the value of the voltage application circuit becomes the value of the constant voltage power supply. If the oil film thickness decreases, the electrical resistance decreases and the voltage value increases, so when the oil film runs out or close to the oil film, the voltage value of the voltage application circuit is almost constant voltage power supply. Is equal to the voltage value of. Thereby, when the voltage value of the voltage application circuit becomes equal to or higher than the reference voltage value, it is determined that the value of the measured voltage is equal to or higher than the reference voltage value. Therefore, an oil film formation failure is detected based on the determination result. It becomes possible. Therefore, it is possible to detect an oil film formation failure without installing a precision device such as a sensor, a camera, or a transmitter inside the compressor body.

  In order to achieve the above object, the present invention provides a plurality of cylinders provided in the compressor body at intervals in the circumferential direction, pistons that reciprocate in the cylinders, and one end of the piston that slides on one end side. A swash plate that is movably engaged and a drive shaft that rotates the swash plate are provided, and one end side of the piston is slidably engaged with the swash plate via a pair of shoes facing each other. In the oil film formation failure detection device of the swash plate compressor, the first conductive means conducting to the shoe of the piston, the second conductive means conducting to the swash plate, and the first and second conductive means are connected from the outside. A voltage applying circuit for applying a voltage of a predetermined magnitude to the first and second conducting means, a voltage measuring means for measuring the voltage value of the voltage applying circuit, and a value of the measurement voltage of the voltage measuring means. Determining means for determining whether or not a predetermined reference value or more; It is provided.

  As a result, when the power supply voltage of the voltage application circuit is applied to the shoe and the swash plate via the first and second conductive means, the gap formed by the oil film between the shoe and the swash plate becomes an electric resistance. The value of the voltage application circuit is smaller than the voltage of the constant voltage power supply, but if the oil film thickness decreases, the electrical resistance decreases and the voltage value increases. The voltage value of the application circuit is substantially equal to the voltage value of the constant voltage power supply. Thereby, when the voltage value of the voltage application circuit becomes equal to or higher than the reference voltage value, the determination means determines that the measured voltage value of the voltage measuring means is equal to or higher than the reference voltage value. Thus, it is possible to detect an oil film formation failure. Therefore, it is possible to detect an oil film formation failure without installing a precision device such as a sensor, a camera, or a transmitter inside the compressor body.

  According to the present invention, an oil film formation failure can be detected without installing a precision device such as a sensor, a camera, or a transmitter inside the compressor body, so the oil film formation failure is reliably detected with a simple structure. can do. Therefore, it is possible to accurately detect oil film formation failure during compressor operation, and to handle various operating conditions, and to detect oil film formation failure without affecting the compressor performance. This is extremely advantageous for practical use.

  FIG. 1 to FIG. 6 show an embodiment of the present invention. FIG. 1 is a schematic side view of an oil film formation defect detection device, FIG. 2 is a cross-sectional view of its main part, and FIG. 4 is a side view of the piston, FIG. 5 is a partially exploded side view thereof, and FIG. 6 is a graph showing the relationship between the voltage and the gap.

  The swash plate type compressor shown in the figure is slidably engaged with a compressor body 10 for sucking and discharging refrigerant, a plurality of pistons 20 provided in the compressor body 10 and one end side of each piston 20. And a drive shaft 40 that rotates the swash plate 30.

  The compressor body 10 includes a housing 11, a cylinder block 12, a cylinder head 13, and a valve plate 14, which are connected to each other in the axial direction by bolts (not shown).

  The housing 11 is formed in a cylindrical shape with one end side closed, and the other end side opens to the cylinder block 12 side.

  The cylinder block 12 has a plurality of cylinders 12a extending in the axial direction of the compressor body 10, and both ends of each cylinder 12a are opened to the housing 11 side and the valve plate 14 side, respectively.

  The cylinder head 13 has a refrigerant discharge chamber 13a and a refrigerant suction chamber 13b, and each of the refrigerant discharge chamber 13a and the refrigerant suction chamber 13b opens to the cylinder block 12 side. The refrigerant discharge chamber 13a is provided at the center of the cylinder head 13 and communicates with an external discharge port (not shown). The refrigerant suction chamber 13b is provided around the refrigerant discharge chamber 13a and communicates with an external suction port (not shown).

  The valve plate 14 is disposed between the cylinder block 12 and the cylinder head 13 and has a plurality of refrigerant discharge holes 14a and refrigerant suction holes 14b communicating with each cylinder 12a. A discharge side plate 14c is arranged on one surface side (cylinder head 13 side) of the valve plate 14, and the discharge side plate 14c is provided with a discharge valve (not shown) for opening and closing each refrigerant discharge hole 14a. . Further, a suction side plate 14d is disposed on the other surface side (cylinder block 12 side) of the valve plate 14, and a suction valve (not shown) for opening and closing each refrigerant suction hole 14b is provided on the suction side plate 14d. ing.

  Each piston 20 is slidably provided in each cylinder 12a, and an engaging portion 21 that engages with the swash plate 30 is formed at one end thereof. The engaging portion 21 has a pair of hemispherical surfaces facing each other, and a hemispherical shoe 22 is slidably provided between the hemispherical surfaces.

  The swash plate 30 is provided so as to be tiltable with respect to the axial direction of the drive shaft 40, and an engaging portion 21 of each piston 20 is slidably engaged with a peripheral portion thereof via a shoe 22. The swash plate 30 is tiltably connected to a rotating plate 31 that rotates integrally with the drive shaft 40. The swash plate 30 is rotated about the drive shaft 40 by the rotating plate 31, and each piston 20 is moved by a stroke amount corresponding to the inclination angle. It is designed to reciprocate. An oil film is formed between the shoes 22 and the swash plate 30 by the lubricating oil circulating in the compressor body 10. In this case, the non-compressed surface of the swash plate 30 (the surface that does not receive the reaction force of the piston 20) is covered with a thin film-like insulating material 30a, and the non-compressed surface of the swash plate 30 and one shoe 22 are connected. It is electrically insulated by the insulating material 30a. As a result, only the compression surface of the swash plate 30 (the surface that receives the reaction force of the piston 20) and the other shoe 22 are electrically connected. Instead of the insulating member 30a, a surface treatment made of an insulating coating may be applied to the compression surface of the swash plate 30.

  One end side of the drive shaft 40 is rotatably supported by the housing 11 via a bearing 41, and the other end side is rotatably supported by the cylinder block 12 via a bearing 42.

  Next, the oil film formation defect detection device of this embodiment will be described. The oil film formation defect detection device 50 includes a terminal 51 provided on the outer surface side of the housing 11, a conductive member 52 provided on the side of the piston 20, and a contact pin 53 as a contact member provided on the piston 20. The voltage application circuit 54 that applies a predetermined voltage to each shoe 22 and the swash plate 30, the voltage measurement device 55 that measures the voltage value of the voltage application circuit 54, and the measurement voltage of the voltage measurement device 55 are The determination processing unit 56 determines whether or not the reference value is equal to or greater than a predetermined reference value, and the terminal 51, the conductive member 52, and the contact pin 53 are provided on both sides of the piston 20 in the width direction.

  The terminal 51 has a screw hole 51a for screwing and is connected to a not-shown conductor of the voltage application circuit 54.

  The conductive member 52 is made of a metal member extending in the sliding direction of the piston 20, and is fastened to the housing 11 by a bolt 52 a that is screwed into the terminal 51. In this case, the bolt 52a is inserted into the through hole 11a provided in the housing 11 and screwed into the terminal 51, and a sleeve 52b for insulating the bolt 52a and the housing 11 is inserted into the through hole 11a. Yes. An insulating coating 52c is formed on the inner peripheral surface of the housing 11, and the conductive member 52 and the housing 11 are insulated by the insulating coating 52c.

  The contact pin 53 is made of a conductive metal, and is slidably inserted into a hole 20 a provided on the side surface of the piston 20. In this case, a spring 53a is provided in the hole 20a, and the contact pin 53 is pressed against the side surface of the conductive member 52 by the spring 53a.

  The piston 20 is provided with a conductive spring 57 as an elastic member that is electrically connected to the shoe 22, and the conductive spring 57 is fixed to the piston 20 so that one end is in contact with the other shoe 22.

  The voltage application circuit 54 is formed by connecting a constant voltage power supply 54a and a variable resistor 54b in series, and the constant voltage power supply 54a generates a DC voltage of a predetermined magnitude (for example, 2.0 [V]). The voltage application circuit 54 has one end side (variable resistor 54 b side) connected to the terminal 51 and the other end side (power supply 54 a side) connected to the housing 11 of the compressor body 10.

  The voltage measuring device 55 is connected to the voltage applying circuit 54 in parallel with the variable resistor 54b, and measures the voltage of the variable resistor 54b.

  The determination processing unit 56 is connected to the voltage measuring device 55 and determines whether or not the voltage value measured by the voltage measuring device 55 is a predetermined reference voltage value V (for example, 1.9 [V]) or more. ing.

  In the oil film formation defect detection device 50, the terminal 51, the conductive member 52, the contact pin 53, the piston 20 and the shoe 22 are sequentially conducted as the first conductive means, and the housing 11 of the compressor body 10 is provided. The drive shaft 40 and the swash plate 30 are sequentially conducted as the second conductive means. In this case, the piston 20 and the shoe 22 are also conducted by the conductive spring 57.

  In the compressor configured as described above, when the drive shaft 40 is rotated by a driving force from the outside, each piston 20 reciprocates in each cylinder 12 a according to the inclination angle of the swash plate 30. As a result, the refrigerant in the refrigerant suction chamber 13b is sucked into each cylinder 12a and discharged into the refrigerant discharge chamber 13a. At that time, the pressure in the housing 11 is adjusted by a pressure control means (not shown), and the pressure applied to the other end side (housing 11 side) of each piston 20 due to the differential pressure generated between the refrigerant suction chamber 13b and the housing 11. Accordingly, the inclination angle of the swash plate 30 changes. Thereby, the stroke amount of each piston 20 becomes large or small, and the discharge amount of the refrigerant changes.

  Further, in the oil film formation failure detection device 50 of the present embodiment, the voltage of the power source 54a of the voltage application circuit 54 is applied to each shoe 22 and the swash plate 30, and the voltage of the variable resistor 54b is changed by the voltage measuring device 55. Measured. At this time, since a gap is formed between the shoe 22 and the swash plate 30 by the oil film of the lubricating oil, this gap becomes an electric resistance, and the value of the measured voltage becomes smaller than the voltage of the power source 54a. That is, as shown in FIG. 5, if the thickness of the oil film is equal to or greater than a normal value (for example, 6 [μm]), the voltage value is almost 0 [V]. When the oil film runs out or is close to the oil film, the voltage value is substantially the voltage value of the power source 54a (for example, 2 [V]. At this time, the measured voltage value is the reference voltage value V (for example, 1 .9 [V]) or more is determined by the determination processing unit 56, and an oil film formation failure is detected based on the determination result, that is, the determination processing unit 56 sets the measured voltage value to the reference voltage value V or more. If it is determined that, for example, a predetermined abnormality processing operation is performed such as stopping the driving of the compressor or operating an alarm device (not shown).

  As described above, according to the present embodiment, a voltage of a predetermined magnitude is applied from the outside to each shoe 22 and swash plate 30 of the piston 20 by the voltage application circuit 54, and the voltage value of the voltage application circuit 54 is changed. By measuring with the voltage measuring instrument 55 and determining by the determination processing unit 56 whether or not the value of the measured voltage is equal to or greater than a predetermined reference value, the formation failure of the oil film between the shoe 22 and the swash plate 30 is detected. Therefore, there is no need to install a precision device such as a sensor, a camera, or a transmitter inside the compressor body 10, and the formation failure of the oil film can be reliably detected with a simple structure. Therefore, it is possible to accurately detect oil film formation failure during compressor operation, and to handle various operating conditions, and to detect oil film formation failure without affecting the compressor performance. This is extremely advantageous for practical use.

  In this case, since the voltage application circuit 54 is connected to the compressor from the outside, it is possible to easily detect the formation failure of the oil film, so that the air conditioning for the vehicle is used for detecting the oil film formation failure of the compressor mounted on the vehicle. It is possible to easily detect an oil film formation failure by connecting the voltage application circuit 54 to the compressor at the time of factory shipment or maintenance even when not provided in the vehicle air conditioner. And versatility can be improved.

  In addition, a terminal 51 to which one end side of the voltage application circuit 54 can be connected is provided on the outer surface side of the compressor body 10, and a conductive member 52 that conducts to the terminal 51 is provided on the side of the piston 20. By providing the conductive contact pin 53 that slidably contacts the member 52, the terminal 51, the conductive member 52, the contact pin 53, the piston 20 and the shoe 22 are sequentially conducted. One end of the voltage application circuit 54 can be electrically connected to the shoe 22 simply by adding simple components such as 52 and the contact pin 53, which is extremely advantageous for cost reduction.

  Furthermore, since the compressor main body 10, the drive shaft 40, and the swash plate 30 are sequentially conducted, a dedicated conductive component is added by connecting the other end side of the voltage application circuit 54 to the compressor main body 10. The other end of the voltage application circuit 54 can be electrically connected to the swash plate 30 without any problem, which is extremely advantageous for cost reduction.

  Further, since each contact pin 53 is pressed against the conductive member 52 by the spring 53a, the contact pin 53 can be reliably brought into contact with the conductive member 52, and conduction between the conductive member 52 and the contact pin 53 is ensured. It can be carried out.

  In this case, since the conductive member 52 and the contact pin 53 are provided on both sides of the piston 20 in the width direction, even if the piston 20 is displaced in the width direction during the reciprocating operation, one of the conductive members 52 is always in contact with one of the conductive members 52. The pin 53 can be brought into contact, and conduction between the conductive member 52 and the contact pin 53 can be performed more reliably. Further, since the rotation of the piston 20 in the circumferential direction can be restricted by the respective conductive members 52 arranged on both sides in the width direction, the piston 20 is always reciprocated stably without providing a separate anti-rotation component. be able to.

  Further, the piston 20 is provided with a conductive spring 57 whose one end is in contact with the other shoe 22, and the piston 20 and the other shoe 22 are also electrically connected by the conductive spring 57. Can be more reliably conducted, and a decrease in conductivity due to an oil film between the piston 20 and the other shoe 22 can be reliably prevented.

  Furthermore, since the voltage value of the variable resistor 54b provided in the voltage application circuit 54 is measured by the voltage measuring device 55, the voltage shown in FIG. 6 can be obtained by adjusting the resistance value of the variable resistor 54b. The correlation with the gap between the swash plate / shoe can be arbitrarily set.

  Further, since one surface (non-compressed surface) of the swash plate 30 and one shoe 22 are insulated by the insulating material 30a, the other surface (compressed surface) of the swash plate 30 and the other shoe 22 are provided. , And the formation failure of the oil film on the compression surface side of the swash plate 30 that is severely lubricated can be reliably detected.

  In addition, although the conductive member 52 and the contact pin 53 of the oil film formation defect detection device 50 in the above embodiment may be provided for each piston 20, it may be provided only for a part of the pistons 20.

  Moreover, in the said embodiment, what showed insulation between one surface (uncompressed surface) of the swash plate 30 and the one shoe | hook 22 was shown, However, as shown in FIG. If the surface (compressed surface) and the other shoe 22 are insulated by the insulating material 30b, the formation failure of the oil film on the non-compressed surface of the swash plate 30 can be detected.

The schematic side view of the oil film formation defect detection apparatus which shows one Embodiment of this invention Cross section of the main part of the oil film formation defect detection device Expanded cross-sectional view of the main part of the oil film formation defect detection device Piston side view Partially exploded side view of piston Graph showing the relationship between voltage and gap The partially exploded side view of the piston which shows other embodiment of this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Compressor main body, 11 ... Housing, 12a ... Cylinder, 20 ... Piston, 30 ... Swash plate, 40 ... Drive shaft, 50 ... Oil film formation defect detection apparatus, 51 ... Terminal, 52 ... Conductive member, 53 ... Contact pin, 53a ... Spring, 54 ... Voltage application circuit, 55 ... Voltage measuring device, 56 ... Determination processing unit, 57 ... Conduction spring.

Claims (10)

A plurality of cylinders provided in the compressor body at intervals in the circumferential direction, pistons that reciprocate in the cylinders, a swash plate that is slidably engaged with one end of the piston, and a swash plate In the oil film formation failure detection method of the swash plate compressor, which includes a drive shaft that rotates, and one end of the piston is slidably engaged with the swash plate via a pair of shoes facing each other between the swash plates.
Applying a voltage of a predetermined constant voltage power source to the conductive means conducting to the shoe and swash plate of the piston by a voltage application circuit,
A method of detecting an oil film formation failure in a swash plate compressor, comprising: measuring a voltage value of a voltage application circuit and determining whether or not the measured voltage value is equal to or greater than a predetermined reference value. A plurality of cylinders provided in the compressor body at intervals in the circumferential direction, pistons that reciprocate in the cylinders, a swash plate that is slidably engaged with one end of the piston, and a swash plate In the oil film formation defect detection device for a swash plate compressor, which includes a drive shaft that rotates, and one end of the piston is slidably engaged with the swash plate via a pair of shoes facing each other between the swash plates.
First conductive means conducting to the shoe of the piston;
A second conductive means conducting to the swash plate;
A voltage application circuit connected to the first and second conductive means from the outside and applying a voltage of a predetermined constant voltage power source to the first and second conductive means;
Voltage measuring means for measuring the voltage value of the voltage application circuit;
An oil film formation defect detection device for a swash plate compressor, comprising: a determination unit that determines whether or not a value of a measurement voltage of the voltage measurement unit is equal to or greater than a predetermined reference value. A terminal provided on the outer surface side of the compressor body, to which a voltage application circuit can be connected;
A conductive member provided on the side of the piston and conducting to the terminal;
A conductive contact member provided on the piston and slidably contacting the conductive member;
The oil film formation defect detection device for a swash plate compressor according to claim 2, wherein the first conductive means is formed such that a terminal, a conductive member, a contact member, a piston, and a shoe are sequentially conducted. The oil film formation defect detection device for a swash plate compressor according to claim 2 or 3, wherein the second conductive means is formed so that the compressor body, the drive shaft, and the swash plate are sequentially conducted. The oil film formation defect detection device for a swash plate compressor according to claim 2, wherein the contact member is provided in pressure contact with the conductive member by a spring. 6. The oil film formation defect detection device for a swash plate compressor according to claim 2, wherein the conductive member and the contact member are provided on both sides of the piston in the width direction. The oil film formation defect detection device for a swash plate compressor according to claim 6, wherein each of the conductive members is provided such that rotation of the piston in the circumferential direction is regulated by the conductive members. The slant according to claim 2, 3, 4, 5, 6 or 7, wherein the piston is provided with a conductive elastic member having one end fixed to the piston so that one end contacts the shoe. Oil film formation defect detection device for plate compressor. The oblique measurement according to claim 2, 3, 4, 5, 6, 7 or 8, wherein the voltage measuring means is configured to measure a voltage value of a variable resistor provided in a voltage application circuit. Oil film formation defect detection device for plate compressor. The oil film formation defect detection device for a swash plate compressor according to claim 2, wherein the swash plate and one shoe are insulated by an insulating material. .

Images