JP3301159B2 - Lubrication method and lubrication structure for clutchless compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating method and a lubricating structure for a clutchless compressor.

[0002]

2. Description of the Related Art In a variable displacement swinging swash plate compressor disclosed in Japanese Patent Application Laid-Open No. 3-143725, an electromagnetic clutch is provided for connecting and disconnecting power transmission between an external drive source and a rotary shaft of the compressor. Not used. Eliminating the electromagnetic clutch can eliminate the drawback of poor physical feeling due to the ON-OFF shock particularly in a vehicle-mounted configuration, and can reduce the weight and cost of the entire compressor.

In the variable displacement type swinging swash plate type compressor disclosed in the above-mentioned conventional publication, the pressure in the crank chamber accommodating the swash plate is rapidly increased so that the swash plate tilt angle approaches 0 °, thereby substantially reducing the discharge capacity. It is designed to drop to zero. By making the discharge capacity substantially zero, the cooling capacity becomes zero.
The load on the compressor decreases sharply due to the sudden decrease in the discharge capacity. When a compressor is mounted on a vehicle, it is desirable to direct all of the vehicle engine output to driving the vehicle when the vehicle is accelerating or climbing a hill. In such a case, the load on the compressor is rapidly reduced. Will be

[0004]

In a clutchless compressor, a rotating shaft is constantly rotating, and a sliding contact portion in the compressor is always in a heat generating state. In the normal capacity control state, the refrigerant circulates through the external refrigerant circuit, and the lubricating oil returns to the compressor. Therefore, a lubricating oil film is always formed at the sliding contact portion, and no seizure occurs at the sliding contact portion. However,
When the discharge capacity becomes substantially zero, the flow rate of the refrigerant circulating in the external refrigerant circuit is almost zero, and the lubricating oil does not return to the compressor. If the lubricating oil does not return to the compressor, poor lubrication occurs in the compressor, and seizure occurs at the sliding contact portion.

An object of the present invention is to ensure good lubrication in a clutchless compressor.

[0006]

According to the first aspect of the present invention, a swash plate tilt angle is variable and a swash plate tilt angle is forcibly held at a minimum tilt angle, and a swash plate tilt angle is reduced to a minimum tilt angle. The present invention is directed to a clutchless compressor having a swash plate tilt angle forcible change means that can be switched to a capacity return holding state that holds a swash plate to an increased capacity return state, detects the temperature of the compressor body and the outside air temperature, When the difference between the detected temperatures is equal to or greater than a predetermined value, the swash plate inclination compulsory changing means is set to the capacity return holding state to circulate the refrigerant.

According to the second aspect of the present invention, the first temperature detecting means for detecting the temperature of the compressor body, the second temperature detecting means for detecting the outside air temperature, and the first temperature detecting means. When the difference between the detected temperature and the temperature detected by the second temperature detecting means is equal to or more than a predetermined value, the capacity control means for circulating the refrigerant by setting the swash plate inclination compulsory changing means to the capacity return holding state. The lubrication structure provided was constructed.
According to the invention described in claim 3, the temperature of the compressor body is sensitive.
The first bimetal that bends and displaces in response to the outside temperature
A second bimetal that bends and displaces.
The amount of bending displacement of the metal and the bending displacement of the second bimetal.
If there is a difference between the temperature of the compressor and the
Assuming that the difference from the temperature has reached a predetermined value or more, the swash plate tilt angle
Set the control change means to the capacity return holding state and circulate the refrigerant
A lubrication structure was constructed.

[0008]

When the difference between the detected temperature of the compressor body and the detected outside air temperature becomes equal to or more than a predetermined value, the swash plate forcible angle changing means enters the capacity return holding state, and the swash plate enters the inclined state larger than the minimum inclination. In this inclined state, the refrigerant circulates through the external refrigerant circuit,
Lubricating oil returns to the compressor. Therefore, the oil film does not break at the sliding contact portion in the compressor.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
A description will be given based on FIG. As shown in FIG. 1, a front housing 2 is joined to a front end of a cylinder block 1 which is a part of a housing of the entire clutchless compressor. A rear housing 3 is joined and fixed to the rear end of the cylinder block 1 via a valve plate 4, valve forming plates 5A and 5B, and a retainer forming plate 6.

A rotary shaft 7 is rotatably supported between the front housing 2 and the cylinder block 1 via radial bearings 8 and 13. The front end of the rotating shaft 7 protrudes outside from the crank chamber 2a in the front housing 2, and a pulley 9 is screwed to the protruding end. The pulley 9 is operatively connected to a vehicle engine via a belt 10. A lip seal 11 is interposed between the front end of the rotating shaft 7 and the front housing 2. The lip seal 11 prevents pressure leakage in the crank chamber 2a.

A rotating support 18 and a position regulating ring 12 are fixed to the rotating shaft 7. A swash plate support 14 having a spherical shape is slidably supported on the rotating shaft 7, and a swash plate 15 is supported on the swash plate support 14 so as to be tiltable in the axial direction of the rotating shaft 7.

The maximum inclination angle of the swash plate 15 is regulated by the contact between the inclination regulating protrusion 18 b of the rotary support 18 and the swash plate 15. The minimum inclination angle of the swash plate 15 is regulated by the contact between the swash plate support 14 and the position regulating ring 12. This minimum tilt angle is not zero.

The connecting pieces 16A and 16B are fixed to the swash plate 15. As shown in FIG. 2, a pair of guide pins 17A, 17B are fixed to the connecting pieces 16A, 16B.
A support arm 18a protrudes from the rotary support 18. As shown in FIG. 2, a support pin 1 is provided on the support arm 18a.
9 is rotatably supported through in a direction perpendicular to the rotating shaft 7. The pair of guide pins 17A and 17B are slidably fitted at both ends of the support pin 19. The swash plate 15 can be tilted about the swash plate support 14 in the axial direction of the rotation shaft 7 and rotated integrally with the rotation shaft 7 by the cooperation of the support pin 19 on the support arm 18a and the pair of guide pins 17A and 17B. It is possible.

The tilting of the swash plate 15 is guided by the slide guide relationship between the support pin 19 and the guide pins 17A and 17B, the sliding action of the swash plate support 14, and the support action of the swash plate support 14.

A single-headed piston 20 is accommodated in a cylinder bore 1b penetrating through the cylinder block 1 so as to be connected to the crank chamber 2a. A pair of shoes 21 is fitted into the neck 20a of the single-headed piston 20. Swash plate 1
The peripheral edge of 5 enters between the two shoes 21, and the end faces of both shoes 21 contact both surfaces of the swash plate 15. Therefore, the swash plate 15
Is converted into a reciprocating swing of the single-headed piston 20 via the shoe 21, and the single-headed piston 20 moves back and forth in the cylinder bore 1b.

As shown in FIGS. 1 and 3, a suction chamber 3a and a discharge chamber 3b are defined in the rear housing 3. A suction port 4a and a discharge port 4b are formed on the valve plate 4. A suction valve 5a is formed on the valve forming plate 5A, and a discharge valve 5b is formed on the valve forming plate 5B. Refrigerant gas in the suction chamber 3a is supplied to the suction port 4a
, The suction valve 5a is pushed away and flows into the cylinder bore 1b. The refrigerant gas flowing into the cylinder bore 1b is discharged by the forward movement of the single-headed piston 20 from the discharge port 4b to the discharge valve 5b to the discharge chamber 3b. Discharge valve 5b
Abuts on the retainer 6 a on the retainer forming plate 6 to regulate the opening.

The stroke of the single-headed piston 20 changes according to the pressure difference between the pressure in the crank chamber 2a and the suction pressure in the cylinder bore 1b through the single-headed piston 20. That is, the inclination angle of the swash plate 15 which affects the compression capacity changes. The pressure in the crank chamber 2a is controlled by a control valve 25 attached to a lower part of the rear housing 3. The control valve 25 changes the valve opening based on the fluctuation of the suction pressure reflecting the cooling load, and controls the amount of refrigerant gas discharged from the discharge chamber 3b to the crank chamber 2a.

A valve housing 41 is fitted and fixed in the housing hole 1a on the end face of the cylinder block 1. A valve seat 42 and a ball valve 43 are housed in the valve housing 41. A closing spring 45 is interposed between the spring seat 44 fixed to the valve housing 41 and the valve seat 42. The ball valve 43 is provided in the valve hole 41 on the valve housing 41.
The spring action of the closing spring 45 is received in the direction of closing the opening a. The housing hole 1a is connected to the crank chamber 2a through the pressure passage 46.
Is in communication with

[0019] The radial center of the rear housing 3 as shown in FIG. 3 discharge pressure region 3b ₁ are formed to extend from the discharge chamber 3b, the discharge pressure region from a portion of the valve housing 41 accommodating hole 1a and projects to 3b _1. Valve hole 4
1a are familiar to the discharge pressure region 3b ₁ via a pressure passage 41b.

At the radial center of the rear housing 3, there is provided an electromagnetic solenoid 47 which constitutes a forcible inclination changing means. A forcible angle change spring 48 is interposed between the fixed iron core 47b and the movable iron core 47c which are excited by energizing the coil 47a. When the electromagnetic solenoid 47 is excited, the movable iron core 47c overcomes the spring force of the tilt angle forcible change spring 48 and is attracted to the fixed iron core 47b. A pressing rod 49 is fixed to the movable iron core 47c. The pressing rod 49 slidably penetrates through the valve housing 41, and the front end of the pressing rod 49 contacts the ball valve 43 through the valve hole 41a.

The electromagnetic solenoid 47 is a control computer C
Under the excitation demagnetization control. An air conditioner operation switch 37 and an air conditioner stop switch 38 are signal-connected to the control computer C. The control computer C instructs the excitation of the electromagnetic solenoid 47 by turning on the air conditioner operation switch 37, and demagnetizes the electromagnetic solenoid 47 by turning on the air conditioner stop switch 38.

As shown in FIGS. 1 and 3, a discharge flange 22 is formed on the upper surface of the cylinder block 1, and a discharge port 1c is provided in the discharge flange 22. An inlet 1d for introducing the refrigerant gas into the suction chamber 3a and an outlet 1c for discharging the refrigerant gas from the discharge chamber 3b are connected by an external refrigerant circuit 33. The discharge port 1c communicates with the discharge chamber 3b via the discharge passage 23. On the external refrigerant circuit 33, a condenser 34, an expansion valve 35, and an evaporator 36 are interposed.

As shown in FIGS. 1 and 4, a first temperature sensor 39 is mounted on the peripheral wall of the front housing 2. The first temperature sensor 39 detects the temperature of the sliding contact portion between the single-headed piston 20 and the front housing 2.
A second temperature sensor 40 is provided at a location away from the compressor body.
Is installed. The second temperature sensor 40 detects an outside air temperature. The detection signals of the two temperature sensors 39 and 40 are sent to the control computer C.

The control computer C serves as capacity control means for controlling the excitation and demagnetization of the electromagnetic solenoid 47 based on the capacity return control program shown in the flowchart of FIG. FIG.
In the state of, the air conditioner operation switch 37 is ON,
The electromagnetic solenoid 47 is in an excited state. The excited state of the electromagnetic solenoid 47 and the ball valve 43 closes the valve hole 41a, the discharge pressure region 3b ₁ of the high-pressure refrigerant gas crankcase 2
a. Therefore, the pressure in the crank chamber 2a is controlled by the control valve 25, and the swash plate inclination is variably controlled according to the suction pressure reflecting the cooling load.

When the air conditioner stop switch 38 is turned on, the electromagnetic solenoid 47 is demagnetized as shown in FIG. 4, and the movable iron core 47c is separated from the fixed iron core 47b by the spring action of the inclination changing force spring 48. The ball valve 43 opens the valve hole 41a by the movement of the movable iron core 47c. The valve opening pressure high-pressure refrigerant gas in the discharge pressure region 3b ₁ a passage 41
b, 46, and flows into the crank chamber 2a. Due to the inflow of the high-pressure refrigerant gas, the pressure in the crank chamber 2a rapidly rises to the discharge pressure, and the inclination angle of the swash plate 15 is minimized. That is,
The swash plate support 14 is moved and arranged at a position where the swash plate support 14 comes into contact with the position regulating ring 12. Accordingly, the discharge capacity becomes small, and in the clutchless compressor of this embodiment, a state close to a compressor no-load state when the clutch is disconnected in the clutch mounted type compressor can be obtained.

That is, the ball valve 43 and the electromagnetic solenoid 4
Reference numeral 7 denotes a swash plate tilt forcible switchable between a minimum tilt holding state in which the swash plate tilt angle is forcibly held at the minimum tilt angle and a capacity return holding state for holding the swash plate 15 in a capacity return state in which the swash plate tilt angle is increased from the minimum tilt angle. Configure the change means.

Even if the clutchless compressor is operated with the swash plate 15 at the minimum inclination angle (> 0), the discharge capacity does not become zero and the refrigerant gas pressure in the clutchless compressor does not become uniform. . Therefore, the pressure in the crank chamber 2a can be reduced, and the swash plate 15 can be tilted from the minimum tilt angle. That is, in the present embodiment, the minimum inclination angle of the swash plate 15 is set to an angle capable of restoring the inclination angle of the swash plate, and the swash plate 15 is inclined from the minimum inclination angle by exciting the electromagnetic solenoid 47.

In such a clutchless compressor, when the electromagnetic solenoid 47 is in the demagnetized state, the swash plate 15 is at the minimum inclination angle, but the swash plate 15 is constantly rotating. For this reason, heat is generated in the sliding contact portion such as between the swash plate 15 and the shoe 21, and the temperature of the compressor body is rising.

The first temperature sensor 39 detects the temperature near the sliding contact between the swash plate 15 and the shoe 21.
The second temperature sensor 40 detects the outside air temperature in the surroundings that is not affected by the temperature of the compressor body. Control computer C
Is the detected temperature Tx obtained from the first temperature sensor 39.
(Tx−Ty) between the detected temperature Ty obtained from the second temperature sensor 40 and a predetermined value ΔT Is compared with. (Tx−Ty) is a predetermined value ΔT Does not reach, the control computer C maintains the current demagnetized state of the electromagnetic solenoid 47 unless the air conditioner operation switch 37 or the air conditioner stop switch 38 is turned ON.

(Tx−Ty) is a predetermined value ΔT In this case, when the electromagnetic solenoid 47 is in the excited state, the control computer C maintains this excited state. When the electromagnetic solenoid 47 is in the demagnetized state, the control computer C excites the electromagnetic solenoid 47. The excitation by the discharge refrigerant gas inflow is stopped from the discharge pressure region 3b ₁ to the crank chamber 2a, the swash plate 15 receives a normal tilt control of the control valve 25. That is, the inclination angle of the swash plate 15 increases from the minimum inclination angle and the capacity is restored, and the flow rate of the refrigerant circulating in the external refrigerant circuit 33 increases. This increase in the flow rate of the circulating refrigerant causes the lubricating oil to flow back to the compressor, thereby avoiding oil film breakage at a required lubrication site in the compressor. Therefore, seizure due to oil film shortage at the sliding contact portion is prevented.

It is also conceivable to judge whether or not to return the capacity based on only the detected temperature Tx of the compressor body. Detection temperature Tx
When the temperature exceeds a predetermined temperature, the capacity is restored, but this does not guarantee high detection accuracy of abnormal heat generation due to oil film shortage. The temperature Tx of the compressor body is affected by the outside air temperature Ty. That is, if the outside air temperature Ty is high, the temperature Tx of the compressor body also becomes high, and if the outside air temperature Ty is low, the temperature Tx of the compressor body becomes low accordingly. In such a situation, it is difficult to properly set the predetermined temperature, which is a measure for avoiding oil film shortage, and depending on the setting, the capacity may be restored even in the state of heat generation of the compressor body where there is no risk of oil film shortage. . Such a malfunction is caused by the evaporator 36.
Affects the occurrence of frost in Under environmental conditions where the outside air temperature is near the freezing point, frost is likely to occur in the evaporator 36, and an unnecessary capacity return state enhances heat exchange in the evaporator 36 to cause frost.

In this embodiment, whether the capacity is restored is determined by the difference (Tx-Ty) between the detected temperature Tx of the compressor body and the outside air temperature Ty, and the outside air temperature Ty affecting the temperature state of the compressor body. Are excluded from the detected temperature Tx. Difference (Tx-
Ty) accurately reflects the degree of heat generation from the inside of the compressor body, and is a predetermined value ΔT for determining the state of the oil film at the sliding contact portion. Can be set appropriately. Therefore,
The capacity return is not performed in the heat generation state of the compressor body where there is no risk of running out of the oil film, and if the risk of running out of the oil film starts to occur, the capacity is recovered and the lubrication is performed well.

In the above embodiment, two temperature sensors 39, 4
0 is used to detect the heat generation state of the compressor, which reflects the lubrication state at the sliding contact portion in the compressor.
Using a single temperature sensor 24 as shown in FIG. 9, the lubrication state at the sliding contact portion in the compressor can be accurately grasped.

As shown in FIG. 7, this temperature sensor 24
A pair of bimetals 27 housed above and below the case 26
A, 27B and a pair of elastically displaceable electrode terminals 28A,
28B and a pair of displacement transmitting rods 29A and 29B. Both the bimetals 27A and 27B are bent and displaced in a direction approaching the peripheral wall of the front housing 2 to which the temperature sensor 24 is attached as the temperature rises.
The bending of the bimetals 27A and 27B is the displacement transmission rod 29.
The signal is transmitted to the electrode terminals 28A, 28B via the terminals A, 29B, and the electrode terminals 28A, 28B are displaced in a curved manner in a direction approaching the peripheral wall of the front housing 2.

The isolator 26a constituting the case 26 is made of a material having low thermal conductivity. The bimetal 27A is responsive exclusively to the outside air temperature, and the bimetal 27B is responsive exclusively to the temperature of the front housing 2. The temperature Tx of the front housing 2 and the outside air temperature Ty are constant temperature conditions (Tx = Ty =
In the case of T ₀ ), the bimetals 27A and 27B are in a parallel state without being curved.

As shown in FIG. 6, the temperature sensor 24, the DC power supply 30, and the air conditioner switch 31 form a series circuit. In the state of FIG. 6, the electrode terminals 28A and 28B are in contact, and the air conditioner switch 31 is ON. Therefore, the series circuit forms a closed circuit, and the electromagnetic solenoid 47 is in an excited state.

The bimetal 27A is bent and displaced in a direction approaching the peripheral wall of the front housing 2 according to the outside air temperature Ty.
According to x, it is curved and displaced in a direction approaching the peripheral wall of the front housing 2. The bending displacement ratio of the bimetal 27A is larger than the bending displacement ratio of the bimetal 27B.
Therefore, even when the temperature Tx of the front housing 2 rises, the difference (Tx-Ty) between the temperatures Tx and Ty becomes the predetermined value Δ
When the temperature does not reach T, the electrode terminals 28A and 28B maintain the contact state as shown in FIG. However, the temperatures Tx, T
When the difference y (Tx-Ty) exceeds a predetermined value ΔT, the electrode terminals 28A and 28B separate as shown in FIG. 9, and the electromagnetic solenoid 47 is demagnetized. The predetermined value ΔT is a value for both bimetals 27.
A and 27B depend on the ratio of the bending displacement ratio.

The bimetal 27B serves as first temperature detecting means corresponding to the temperature sensor 39 of the embodiment shown in FIG. 1, and the bimetal 27A serves as second temperature detecting means corresponding to the temperature sensor 40 of the embodiment shown in FIG. Such a temperature sensor 23
Is adopted, the control computer C used in the embodiment of FIG. 1 becomes unnecessary, and the configuration of the control circuit is simplified.

[0039]

As described above in detail, according to the present invention, when the difference between the detected temperature of the compressor body and the detected outside air temperature exceeds a predetermined value, the capacity is restored. This provides an excellent effect that the sliding portion in the compressor can be accurately lubricated.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an entire clutchless compressor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a side sectional view of the compressor showing a state where a swash plate tilt angle is minimum.

FIG. 5 is a flowchart showing a capacity return control program.

FIG. 6 is a side sectional view of the entire clutchless compressor using a temperature sensor of another example.

FIG. 7 is an enlarged sectional view showing a state where electrode terminals of the temperature sensor are in contact with each other.

FIG. 8 is an enlarged sectional view showing a state where electrode terminals of the temperature sensor are in contact with each other.

FIG. 9 is an enlarged sectional view showing a state in which electrode terminals of the temperature sensor are separated from each other.

[Explanation of symbols]

Reference numeral 15: swash plate, 27A: bimetal serving as second temperature detecting means of another example, 27B ... bimetal serving as first temperature detecting means of another example, 39: first temperature sensor, 40: second temperature sensor Reference numeral 43 denotes a ball valve that constitutes a swash plate inclination forcible change unit; 47, an electromagnetic solenoid that constitutes a swash plate inclination forcible change unit;

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masanori Sonobe 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (56) References JP-A-3-143725 (JP, A) JP-A Heihei 4-3255871 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27/08 F04B 27/14

Claims (3)

(57) [Claims] A swash plate tilt angle is variable, and a swash plate is held in a minimum tilt holding state in which the swash plate tilt angle is forcibly held at the minimum tilt angle and a swash plate is held in a capacity reset state in which the swash plate tilt angle is increased from the minimum tilt angle. A clutch-less compressor provided with a swash-plate-inclination forcible change means that can be switched to a state in which the temperature of the compressor body and the outside air temperature are detected. A method of lubricating a clutchless compressor in which a refrigerant is circulated with a change means in a capacity return holding state. 2. A swash plate with a variable swash plate tilt angle, wherein a swash plate is held in a minimum tilt holding state in which the swash plate tilt angle is forcibly held at the minimum tilt angle and a swash plate is held in a capacity reset state in which the swash plate tilt angle is increased from the minimum tilt angle. A clutchless compressor including a swash plate forcible angle changing means for switching to a state, a first temperature detecting means for detecting a temperature of the compressor body, a second temperature detecting means for detecting an outside air temperature, When the difference between the temperature detected by the first temperature detecting means and the temperature detected by the second temperature detecting means becomes equal to or greater than a predetermined value, the swash plate inclination compulsory changing means is set to the capacity return holding state and the refrigerant is set. Lubrication structure in a clutchless compressor provided with capacity control means for circulating oil. 3. The swash plate tilt angle is variable, and the swash plate tilt angle is minimized.
The minimum tilt holding state forcibly holding the tilt and the swash plate tilt angle
Capacity to hold the swash plate in the capacity return state increased from a small tilt angle
Swash plate tilt angle compulsory change means that can be switched to the return holding state
In the clutchless compressor provided with the first, the first bi-medium that bends and displaces in response to the temperature of the compressor body.
And a second bimetal that bends and displaces in response to the outside temperature.
The bending displacement of the first bimetal and the second bar
When there is a difference between the bending displacement of the metal and the
Assume that the difference between the temperature of the main unit and the outside
The forced swash plate inclination changing means to the capacity return holding state.
-Less compression characterized by circulating refrigerant
Lubrication structure in the machine.