JP2001012346A - Reciprocating compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a thrust bearing and reduce the power loss by regulating the pressure of a crank chamber according to the sliding quantity of a drive shaft, and controlling the relation of the pressure of a cylinder bore with the pressure of the crank chamber so as to keep the average value of the thrust fluctuating load at zero. SOLUTION: In a single head reciprocating fixed displacement type compressor, an axially forward thrust fluctuating load acts on a drive shaft 16 through a piston 35 and a swash plate 31 according to the intermittent compressing motion of coolant gas, and the load is received by a thrust bearing 32. On the other hand, the blowby from a cylinder bore 33 or a high-pressure coolant gas passed through feed passages 18, 12a, 44 is supplied to a crank chamber 15, and its pressure works an axially backward thrust load to the drive shaft 16. The relation of the pressure of the cylinder bore 33 with the pressure of the crank chamber 15 is controlled by a control valve device 46 having a valve part 47 so as to keep the average value of the thrust fluctuating load at zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston type compressor for compressing refrigerant gas, for example, used in a vehicle air conditioner.

[0002]

2. Description of the Related Art As this type of piston compressor (hereinafter simply referred to as a compressor), for example, there is one as shown in FIG. That is, the housing 101 has a crankcase
A drive shaft 103 is rotatably held while a partition 102 is formed. Lip seal 104 is housing 101
To seal the drive shaft 103. Swash plate 105
Are fixed to a drive shaft 103 in a crank chamber 102. The thrust bearing 106 is interposed between the front end (left side in the drawing) of the swash plate 105 and the inner wall surface of the housing 101 in the crank chamber 102.

[0003] Cylinder bore 107, suction chamber 108 and discharge chamber
109 are formed in the housing 101, respectively. The single-headed piston 110 is reciprocally housed in the cylinder bore 107 and connected to the swash plate 105. The valve / port forming body 111 is disposed in the housing 101, and separates the cylinder bore 107 and the suction chamber 108 and the cylinder bore 107 and the discharge chamber 109 which are adjacent to each other.

Then, the rotational movement of the drive shaft 103 is converted into a reciprocating movement of a piston 110 via a swash plate 105,
Suction port 111a and suction valve 111b of valve / port forming body 111
Suction of refrigerant gas from the suction chamber 108 into the cylinder bore 107, compression of the suction refrigerant gas, and discharge of the refrigerant gas through the discharge port 111c and the discharge valve 111d of the valve / port forming body 111.
The compression cycle of discharging the compressed refrigerant gas to the discharge chamber 109 is repeated.

[0005]

With the above-described intermittent refrigerant gas compression operation, a thrust fluctuating load is applied to the drive shaft 103 toward the front of the axis L via the piston 110 and the swash plate 105. Have been. This cylinder bore 10
The fluctuating thrust load applied based on the pressure of 7
Thrust bearing 106 between 105 and housing 101
Received by The greater the peak of this thrust fluctuation load, the more the durability of the thrust bearing 106 becomes a problem. Thrust bearings for this problem
The large capacity (larger size) of 106 had to be dealt with, which was a factor in increasing the size of the compressor.

On the other hand, high pressure refrigerant gas is supplied to the crank chamber 102 by a blow-by from a cylinder bore 107. The blow-by gas is a main factor for increasing the pressure in the crank chamber 102. This crankcase 10
2 is applied to the drive shaft via the piston 110 and the swash plate 105.
A thrust load directed toward the rear of the axis L (to the right in the drawing) is applied to 103. That is, the thrust load based on the pressure in the crank chamber 102 acts on the drive shaft 103 so as to offset the thrust fluctuation load based on the pressure in the cylinder bore 107. Therefore, the load on the thrust bearing 106 can be reduced by increasing the amount of the blow-by gas.

However, the relationship between the pressure in the cylinder bore 107 and the pressure in the crank chamber 102 is constantly changed in accordance with the operating condition of the compressor. For example, the suction pressure is changed in accordance with the cooling load, the discharge pressure is changed in accordance with the change in the condensing capacity in the refrigeration circuit, and the rotation speed of the drive shaft 103 is changed. Therefore, the average value of the thrust fluctuation load applied to the thrust bearing 106 is constantly changed. The compressor shown in FIG.
It is not possible to set and maintain the average value of the thrust fluctuating load applied to the thrust bearing 106 to be zero because it does not have a configuration for positively adjusting the pressure of 102. .

As a result, in a situation where the average value of the fluctuating thrust load applied to the thrust bearing 106 is shifted forward from zero, the load on the thrust bearing 106 increases and the problem of durability can be solved. Is hard to say. Conversely, in a situation where the average value of the thrust fluctuation load applied to the thrust bearing 106 is shifted rearward from zero, for example, the following problem has occurred.

(1) The drive shaft 103, which is not restricted by the movement of the thrust bearing 106, slides largely toward the rear side of the axis L. Therefore, the sliding position with the lip seal 104 may greatly deviate from a predetermined position called a contact line. On the outer peripheral surface of the drive shaft 103,
Foreign matter, such as sludge, often adheres to portions off the contact line. For this reason, lip seal
In the case of 104, the sludge was caught between the drive shaft 103 and the shaft, so that the shaft sealing performance was deteriorated and a problem such as gas leakage occurred.

(2) When the drive shaft 103 slides greatly toward the rear side of the axis L, the piston 110 connected to the drive shaft 103 via the swash plate 105 slides rearward in the cylinder bore 107. And the dead point is
An attempt is made to largely shift to the port forming body 111 side. Therefore,
When the piston 110 is located at the top dead center, the valve / port formation
There has been a problem such as a collision with the shock absorber 111, vibration and noise caused by the collision, and breakage of at least one of the piston 110 and the valve / port forming body 111.

To solve such a problem, for example,
As shown by a two-dot chain line in FIG. 7, an urging member 112 such as a spring for urging the drive shaft 103 forward of the axis L is required, which has caused a problem of high cost due to an increase in the number of parts. However, the provision of the biasing member 112 is intended for a situation in which the average value of the thrust fluctuation load applied to the thrust bearing 106 is shifted rearward from zero.
If the average value of the fluctuating thrust load is deviated forward from zero, the thrust bearing 106
The problem of the durability of the device is further exacerbated.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems existing in the prior art, and has as its object to appropriately maintain the relationship between the pressure in the cylinder bore and the pressure in the crank chamber. It is to provide a piston type compressor.

[0013]

According to the first aspect of the present invention, a crank chamber and a cylinder bore are formed in a housing, and a drive shaft is rotatable so as to pass through the crank chamber. A cam plate is connected to the drive shaft so as to be integrally rotatable in the crank chamber, a single-headed piston connected to the cam plate is reciprocally housed in the cylinder bore, and the housing corresponds to the cylinder bore. A valve / port forming body having a suction port, a suction valve, a discharge port, and a discharge valve is disposed so as to close the cylinder bore with the piston, and the rotational movement of the drive shaft causes the piston to reciprocate via the cam plate. In the piston type compressor in which gas is compressed in the cylinder bore by being converted into motion, The chamber and the discharge pressure region are communicated via an air supply passage, and the crank chamber and the suction pressure region are communicated via a bleed passage, and supply is performed based on the amount of sliding movement of the drive shaft back and forth in the axial direction. A control valve device that adjusts the opening degree of at least one of the air passage or the bleed passage, wherein the control valve device slides in a direction in which the drive shaft moves the piston closer to the valve / port forming body, The opening degree of at least one of the air supply passage or the bleed passage is adjusted to the side that lowers the pressure in the crank chamber, and the drive shaft controls the valve of the piston.
When sliding in the direction away from the port forming body, the opening degree of at least one of the air supply passage or the bleed passage is adjusted to increase the pressure in the crank chamber.

[0014] In this configuration, the control valve device changes the relationship between the pressure in the crank chamber and the pressure in the cylinder bore in accordance with the amount of sliding movement of the drive shaft from a certain reference position back and forth in the axial direction. Accordingly, the opening degree of at least one of the air supply passage and the bleed passage is adjusted to positively change the pressure in the crank chamber. Therefore, for example, the relationship between the pressure in the cylinder bore and the pressure in the crank chamber can be suitably maintained by changes in the suction pressure, the discharge pressure, the rotation speed of the drive shaft, and the like.

According to the second aspect of the present invention, the control valve device includes:
At least the air supply passage is opened and closed. In this configuration, the control valve device handles the high-pressure refrigerant gas for adjusting the pressure of the crankcase, and for example, handles the refrigerant gas having a lower pressure than that of the control valve device. Can be changed to

According to the third aspect of the present invention, the control valve device includes:
It is characterized in that it comprises a valve body that is integrally slidably connected to the drive shaft and that adjusts the opening of at least one of the air supply passage and the bleed passage.

In this configuration, the control valve device autonomously adjusts the opening of at least one of the air supply passage or the bleed passage in accordance with the sliding movement amount of the drive shaft. So, for example,
Compared with the invention of claim 4 described below, the configuration of the control valve device can be simplified by the amount that there is no need to provide an electrical configuration.

According to a fourth aspect of the present invention, the control valve device comprises:
An external control valve for adjusting the opening of at least one of the air supply passage or the bleed passage by electric drive, a movement amount detection sensor for detecting a slide movement amount of the drive shaft, and a drive shaft detected by the movement amount detection sensor And a valve control means for controlling power supply to the external control valve based on the amount of slide movement of the valve.

In this configuration, the control valve device is configured to adjust the opening of at least one of the air supply passage and the bleed passage by external control. For this reason, in the air supply passage or the bleed passage that is not affected by the position of the drive shaft as in the third aspect of the invention, the degree of freedom in setting the position of the air supply passage or the bleed passage increases.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to third embodiments of the present invention which are embodied in a single-head piston type compressor used in a vehicle air conditioner will be described. In the second and third embodiments, only differences from the first embodiment will be described, and the same members will be denoted by the same reference numerals and description thereof will be omitted.

(First Embodiment) As shown in FIG. 1, a front housing 11 is joined and fixed to a front end of a cylinder block 12 as a center housing. The rear housing 13 is joined and fixed to the rear end of the cylinder block 12 via a valve / port forming body 14. valve·
The port forming body 14 includes a suction valve forming plate 14b on the front side of the port forming plate 14a, a discharge valve forming plate 14c on the rear side,
A retainer forming plate 14d is superposed on the rear side of the discharge valve forming plate 14c. The front housing 1
1, the cylinder block 12 and the rear housing 13 constitute a compressor housing. In addition, let the left of FIG. 1 be the front of a compressor, and let the right be the back.

The crank chamber 15 is defined by being surrounded by the front housing 11 and the cylinder block 12. The drive shaft 16 is disposed so as to pass through the crank chamber 15, and is rotatably supported between the front housing 11 and the cylinder block 12.

The front end of the drive shaft 16 is supported by the front housing 11 via a radial bearing 17. The accommodation chamber 12 a is provided through the center of the cylinder block 12. The rear end side of the drive shaft 16 is the accommodation chamber 12a
Radial bearing 1 which is inserted into the shaft and consists of roller bearings
8 is supported. The rear opening of the storage chamber 12 a is closed by the valve / port forming body 14.

The front end of the drive shaft 16 projects through the front housing 11 to the outside. Drive shaft 1
A lip seal 22 is used as the shaft sealing device 6, and the lip seal 22 is interposed between the front end of the drive shaft 16 and the front housing 11. The lip seal 22 seals the drive shaft 16 by pressing against the outer peripheral surface of the drive shaft 16 with a lip ring 22a.

The electromagnetic friction clutch 23, which will not be described in detail,
It is interposed between the vehicle engine Eg as an external drive source and the drive shaft 16. When the friction clutch 23 is turned on while the vehicle engine Eg is operating, the driving force of the vehicle engine Eg is transmitted to the drive shaft 16 via the belt 26 and the friction clutch 23. When the friction clutch 23 is turned off from this transmission state, transmission of the driving force from the vehicle engine Eg to the drive shaft 16 is interrupted.

The swash plate 31 serving as a cam plate is housed in the crank chamber 15 and is externally fitted and fixed to the drive shaft 16 through a boss 31a integrally formed at the center thereof. The bearing seat 11 a protrudes from the inner wall surface of the front housing 11 in the crank chamber 15 so as to surround the drive shaft 16. Thrust bearing 32
Are the front end face of the boss 31a of the swash plate 31 and the bearing seat 1
It is arranged to be sandwiched between the front end face of the main body 1a.

A plurality (only one appears in the drawing)
The cylinder bore 33 is formed in the cylinder block 12. The single-headed piston 35 is provided in each cylinder bore 3
3 housed. The cylinder bore 33 includes the piston 3
5 and the front surface of the valve / port forming body 14 are closed front and rear. The piston 35 is moored on the outer peripheral portion of the swash plate 31 via a shoe 36. And the drive shaft 16
Is converted into a reciprocating motion of the piston 35 in the cylinder bore 33 via the swash plate 31 and the shoe 36.

A suction chamber 37 serving as a suction pressure area is defined on the outer peripheral side of the rear housing 13. The discharge chamber 38 as a discharge pressure region is defined in the rear housing 13 on the inner peripheral side of the suction chamber 37. The suction chamber 37 and the discharge chamber 38 are respectively adjacent to the cylinder bore 33 via the valve / port forming body 14. The suction port 39 and the discharge port 40 are connected to the valve / port forming body 1.
The four port forming plates 14a are formed corresponding to the cylinder bores 33, respectively. The suction valve 41 is formed on the suction valve forming plate 14b so as to correspond to the suction port 39. The discharge valve 42 is formed corresponding to the discharge port 40 on the discharge valve forming plate 14c. The retainer 43 is formed on the retainer forming plate 14d so as to correspond to the discharge valve 42. The retainer 43 regulates the maximum opening of the discharge valve 42.

Then, the refrigerant gas in the suction chamber 37 moves from the top dead center side of the piston 35 to the bottom dead center side, and then moves through the suction port 39 and the suction valve 41 to the cylinder bore 33.
Inhaled to. The refrigerant gas sucked into the cylinder bore 33 is compressed to a predetermined pressure by moving from the bottom dead center side to the top dead center side of the piston 35 and discharged to the discharge chamber 38 through the discharge port 40 and the discharge valve 42. Is done.

Next, a characteristic configuration of the present embodiment will be described. As shown in FIG. 1, the housing chamber 12 a is provided with a crank chamber 1 through a roller gap of a radial bearing 18.
5 is connected. The communication hole 44 is the valve / port forming body 1
4 is formed through the center. The communication hole 44 connects the discharge chamber 38 and the storage chamber 12a. The roller gap of the radial bearing 18, the accommodation chamber 12a and the communication hole 44
Constitutes an air supply passage. Therefore, the discharge chamber 38 and the crank chamber 15 are communicated via the air supply passage (18, 12a, 44). The bleed passage 45 includes the crank chamber 15 and the suction chamber 3.
7 is communicated. The bleed passage 45 has a fixed throttle in the middle.

The control valve device 46 is connected to the air supply passage (18, 1).
2a, 44). The control valve device 46 is
The air supply passages (18, 12a, 4) are based on the amount of slide movement of the drive shaft 16 from a certain reference position back and forth in the direction of the axis L.
4) Adjust the opening. Hereinafter, the control valve device 46 will be described in detail.

As shown in FIG. 2, the rear end of the drive shaft 16 extends to the vicinity of the valve / port forming body 14 in the accommodation chamber 12a. That is, the drive shaft 16 is
In comparison with the conventional compressor shown in FIG. The rear end of the drive shaft 16 forms a valve part 47 as a valve body, and the rear end face of the valve / port forming body 14 (suction valve forming plate 14b) facing the front end face is the valve part 47.
Side blocking surface 47a. Valve / port forming body 14
The shutoff surface 48 on the side is formed in the suction valve forming plate 14b exposed to the storage chamber 12a so as to face the shutoff surface 47a on the valve unit 47 side. The communication hole 44 is opened at the center (axis L) of the blocking surface 48 on the valve / port forming body 14 side in the housing chamber 12a.

As shown in an enlarged manner in FIG.
7 and the valve / port forming body 14 side both blocking surfaces 47a, 4
8, a lubricating film 49 is formed. The lubricating film 49 is made of, for example, a solid lubricant made of a fluororesin such as polytetrafluoroethylene.

Next, the characteristic operation of this embodiment will be described. Along with the above-described intermittent compression operation of the refrigerant gas, a thrust fluctuation load directed toward the front of the axis L is applied to the drive shaft 16 via the piston 35 and the swash plate 31. The thrust fluctuation load applied based on the pressure of the cylinder bore 33 is received by the thrust bearing 32 between the swash plate 31 and the front housing 11.

On the other hand, blow-by from the cylinder bore 33 and the supply passages (18, 12)
a, 44), high-pressure refrigerant gas is supplied. The refrigerant gas in the crank chamber 15 is constantly discharged to the suction chamber 37 via the bleed passage 45. The pressure in the crank chamber 15 is determined by the relationship between the supply amount of the high-pressure refrigerant gas and the amount of the refrigerant gas released to the suction chamber 37. The pressure in the crank chamber 15 causes a thrust load toward the rear side of the axis L to act on the drive shaft 16 via the piston 35 and the swash plate 31. That is, the drive shaft 16
The thrust load based on the pressure in the crank chamber 15 acts so as to cancel the fluctuating thrust load based on the pressure in the cylinder bore 33. Therefore, the thrust bearing 32 is subjected to the thrust variation load based on the pressure in the cylinder bore 33 weakened by the thrust load based on the pressure in the crank chamber 15.

The gap between the valve portion 47 (the shut-off surface 47a and the shut-off surface 48 on the valve / port forming body 14 side in the state shown by the solid line in FIG. 2 is, for example, 0.1 to 0.5 mm;
The drawings are exaggerated in each drawing) when the compressor is in a certain operation state, specifically, for example, when the suction pressure, the discharge pressure, the rotation speed of the drive shaft 16 and the like have a certain value, respectively.
The supply passages (18, 12) are adjusted so that the average value of the thrust fluctuation load applied to the thrust bearing 32 becomes zero.
a, 44), that is, the pressure of the crank chamber 15 is adjusted. When the suction pressure, the discharge pressure, the number of revolutions of the drive shaft 16 and the like change from this state, the pressure in the cylinder bore 33 immediately changes, and the thrust bearing 32
The average value of the thrust fluctuation load applied to the vehicle shifts forward or backward from zero.

As shown by the two-dot chain line X1 in the graph of FIG.
For example, in a situation where the average value of the thrust fluctuation load applied to the thrust bearing 32 is shifted rearward from zero (the state shown by the solid line in the graph), the drive shaft 16 is slid rearward. As shown by a two-dot chain line in FIG. 2, when the drive shaft 16 slides rearward, the valve part 47 integrated therewith is moved to the valve / port forming body 14.
Close to. Therefore, the shutoff surface 47a on the valve part 47 side narrows the interval between the shutoff surface 48 on the valve / port forming body 14 side, and the cross-sectional area of the passage of the refrigerant gas between the communication hole 44 and the storage chamber 12a, That is, the air supply passages (18, 12a, 4
4) The opening degree is reduced.

As described above, the air supply passages (18, 12a,
When the opening degree of 44) is reduced, the supply amount of the high-pressure refrigerant gas from the discharge chamber 38 to the crank chamber 15 through the air supply passages (18, 12a, 44) is reduced. Therefore, the pressure in the crank chamber 15 is reduced, and the thrust load applied to the drive shaft 16 based on this pressure is reduced. As a result, the average value of the thrust fluctuation load applied to the thrust bearing 32 is returned to the zero side.

As shown by the two-dot chain line X2 in the graph of FIG.
Conversely, in a situation where the average value of the thrust fluctuation load applied to the thrust bearing 32 is shifted forward from zero, the drive shaft 16 is slid forward. As shown by a two-dot chain line in FIG. 2, when the drive shaft 16 slides forward, the valve portion 47 separates from the valve / port forming body 14. Accordingly, the gap between the shut-off surface 47a on the valve portion 47 side and the shut-off surface 48 on the valve / port forming body 14 side is increased, and the air supply passages (18, 12a, 4) are formed.
4) The opening degree is increased.

When the opening of the air supply passage (18, 12a, 44) is increased, the supply of high-pressure refrigerant gas from the discharge chamber 38 to the crank chamber 15 through the air supply passage (18, 12a, 44) The amount increases. Accordingly, the pressure in the crank chamber 15 is increased, and the thrust load applied to the drive shaft 16 is increased based on the pressure. As a result, the average value of the thrust fluctuation load applied to the thrust bearing 32 is returned to the zero side.

The present embodiment having the above configuration has the following effects. (1) The control valve device 46 adjusts the pressure in the crank chamber 15 in accordance with the amount of sliding movement of the drive shaft 16, so as to maintain a suitable relationship between the pressure in the cylinder bore 33 and the pressure in the crank chamber 15, ie, The thrust bearing 32 is operated to maintain the average value of the thrust fluctuation load applied to the thrust bearing 32 at zero. Therefore, the load on the thrust bearing 32 can be reduced,
2 improves durability and reduces power loss.

On the other hand, the large sliding movement of the drive shaft 16 to the rear side is performed when the rear end of the
Is regulated by contact with Therefore, the sliding position between the drive shaft 16 and the lip seal 22 greatly deviates from the contact line, or the piston 35 and the valve / port forming body 14
Can be avoided.

However, the rear end of the drive shaft 16 and the valve
If the state in which the port forming body 14 is strongly pressed continues for a long time, problems such as deterioration of wear and increase in power loss due to sliding between the two members 16 and 14 newly arise. However, in the present embodiment, when the rear end portion of the drive shaft 16 (the blocking surface 47a of the valve portion 47) is in contact with the valve / port forming body 14 (the blocking surface 48), the air supply passages (18, 12a) are provided. , 44) are fully closed. As a result, the pressure in the crank chamber 15 is reliably reduced, and the average value of the thrust fluctuation load applied to the thrust bearing 32 is returned to zero, so that the rear end of the drive shaft 16 and the valve / port forming body 14 Is immediately released.

For example, in the conventional compressor shown in FIG. 7, even when the rear end of the drive shaft 103 is extended toward the valve / port forming body 111, the same as in the present embodiment,
The sliding position between the drive shaft 103 and the lip seal 104 can be prevented from greatly deviating from the contact line, and the state where the piston 110 and the valve / port forming body 111 collide can be avoided. However, since the compressor of FIG. 7 does not have the control valve device 46 as in the present embodiment, the pressure in the crank chamber 102 cannot be positively changed.
Therefore, the pressure state between the rear end of the drive shaft 103 and the valve / port forming body 111 is prolonged, and the above-mentioned new problem occurs.

(2) The control valve device 46 is connected to the air supply passage (18, 18).
12a, 44). That is, the control valve device 46 handles the high-pressure refrigerant gas for adjusting the pressure of the crank chamber 15, and, for example, handles the refrigerant gas having a lower pressure than that of opening and closing only the bleed passage 45. The pressure can be changed quickly.

(3) The valve body (valve portion 47) provided in the control valve device 46 is provided so as to be integrally slidable on the drive shaft 16. That is, the control valve device 46 autonomously supplies the air supply passage (1) in accordance with the sliding movement amount of the drive shaft 16.
8, 12a, 44) is adjusted. Therefore, for example, as compared with a second embodiment described later, the electromagnetic unit 52b,
There is no need to provide an electrical configuration such as the movement amount detection sensor 53 and the control computer C, and the configuration of the control valve device 46 can be simplified.

(4) The rear end of the drive shaft 16 is extended and used as the valve portion 47. Therefore, the number of parts can be reduced as compared with a configuration in which a valve body is provided separately from the drive shaft 16 and they are connected by any connecting member.

(5) The lubricating film 49 is formed on both the shut-off surfaces 47a and 48 on the valve portion 47 side and the valve / port forming body 14 side, respectively. Therefore, the rear end of the drive shaft 16 and the valve
Problems such as wear deterioration and increase in power loss of the compressor due to contact with the port forming body 14 can be more effectively solved.

(Second Embodiment) FIG. 4 shows a second embodiment. In the present embodiment, the configuration of the control valve device 51 is different from that of the first embodiment.

That is, the air supply passage 54 directly communicates the discharge chamber 38 and the crank chamber 15 without passing through the storage chamber 12a. That is, in the present embodiment, the drive shaft 16
They do not expect to function as a valve.
An external control valve 52 composed of an electromagnetic valve includes a valve body 52a that opens and closes an air supply passage 54, and an electromagnetic unit 52b that drives the valve body 52a.
It consists of The movement amount detection sensor 53 is provided in the accommodation room 1.
In 2a, it is arranged so as to face the drive shaft 16, and detects the sliding movement amount of the drive shaft 16 from a certain reference position. The control computer C as the valve control means controls the power supply to the electromagnetic unit 52b of the external control valve 52 based on the sliding movement amount of the drive shaft 16 detected by the movement amount detection sensor 53, and operates the valve body 52a to supply power. The opening degree of the air passage 54 is adjusted.

Also in this embodiment, the control valve device 51
The thrust bearing 32 is operated so as to maintain the average value of the thrust fluctuation load applied to the thrust bearing 32 at zero. Therefore,
The same effects as (1) and (2) of the first embodiment can be obtained. In addition, since the control valve device 51 is configured to externally adjust the opening degree of the air supply passage 54, the air supply passage 54 that is not affected by the arrangement position of the drive shaft 16 has a degree of freedom in setting the arrangement position. Increase.

(Third Embodiment) The piston type compressor of this embodiment is different from the first embodiment in that the discharge capacity can be changed.

That is, as shown in FIGS. 5 and 6, the rotary support 56
6 fixed. The swash plate 31 is supported by the drive shaft 16 so as to be tiltable and slidable in the direction of the axis L. The hinge mechanism 57 includes the swash plate 31 and the rotation support 56.
And is interposed between them. The swash plate 31 includes a rotating support 56.
Is hinged via a hinge mechanism 57 with respect to the drive shaft 16 so as to be able to rotate integrally with the drive shaft 16 and change the inclination angle. The thrust bearing 32 is interposed between the inner wall surface of the front housing 11 and the rotating support 56.

The minimum inclination angle defining section 58 is provided with the drive shaft 16.
Is provided between the swash plate 31 and the cylinder block 12. As shown in FIG. 6, the minimum inclination angle of the swash plate 31 is defined by contact with the minimum inclination angle defining part 58.

The displacement control passage 59 communicates the discharge chamber 38 with the crank chamber 15. The capacity control valve 60 composed of an electromagnetic valve is interposed on the capacity control passage 59. The capacity control valve 60 adjusts the opening degree of the capacity control passage 59, whereby the amount of high-pressure discharge refrigerant gas introduced into the crank chamber 15 is adjusted, and the above-described blow-by gas and the air supply passages (18, 12a) are adjusted. , 44), the pressure of the crank chamber 15 is determined by the relationship between the amount of high-pressure refrigerant gas introduced from the discharge chamber 38 into the crank chamber 15 via the bleed passage 45 and the amount of refrigerant gas released into the suction chamber 37. Be changed. Accordingly, the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 33 via the piston 35 is changed, and the inclination angle of the swash plate 31 is changed. As a result, the stroke amount of the piston 35 is changed, and the discharge capacity is adjusted.

The variable displacement compressor provided with the displacement control valve 60 composed of an external control valve (electromagnetic valve) can control the discharge displacement irrespective of the magnitude of the cooling load. For example, a so-called acceleration cut or the like that reduces the load on the vehicle engine Eg by minimizing the discharge capacity during acceleration of the vehicle. When the acceleration cut is performed from a state where the cooling load is large (a state of the maximum discharge capacity), the capacity control valve 6
0 means that the capacity control passage 59 in the fully closed state is suddenly fully opened. Therefore, the refrigerant gas in the discharge chamber 38 is rapidly supplied to the crank chamber 15, and the bleed passage 45 cannot completely escape the rapid inflow of the refrigerant gas.
Pressure rises excessively. As a result, the differential pressure between the crank chamber 15 and the cylinder bore 33 is excessively enlarged, and the swash plate 31 having the minimum inclination angle is pressed against the minimum inclination angle defining portion 58 with excessive force, or the swash plate 31 is moved through the hinge mechanism 57. As a result, the rotary support 56 is strongly pulled. Therefore, drive shaft 1
6 largely slides rearward on the axis L.

However, the large sliding movement of the drive shaft 16 to the rear side is restricted by the rear end contacting the valve / port forming body 14. Therefore, it is possible to prevent the sliding position between the drive shaft 16 and the lip seal 22 from greatly deviating from the contact line, and to prevent the piston 35 from colliding with the valve / port forming body 14. The pressure state of the rear end of the drive shaft 16 and the valve / port forming body 14 is quickly increased by the control valve device 46 reliably reducing the pressure in the crank chamber 15 in the same manner as in the first embodiment. Will be released.

Here, the aforementioned air supply passages (18, 12)
If the pressure in the crank chamber 15 is too low due to the full closing of (a, 44), the drive shaft 16 is separated from the valve / port forming body 14, and furthermore, the swash plate 31 is separated from the minimum inclination angle defining portion 58. There is a risk. However, the control valve device 46
Increases the opening degree of the air supply passage (18, 12a, 44) in accordance with the forward sliding movement of the drive shaft 16. Therefore, before the swash plate 31 separates from the minimum inclination angle defining portion 58, the pressure in the crank chamber 15 is prevented from lowering more than necessary, and the swash plate 31 maintains the minimum inclination angle, and the compressor is operated as desired. Can be maintained.

The present invention can be implemented in the following modes without departing from the spirit of the present invention. In each of the above embodiments, the control valve devices 46 and 51 are configured to open and close only the bleed passage 45. In this case, the control valve devices 46 and 51 increase the opening of the bleed passage 45 when the drive shaft 16 slides rearward.
When the drive shaft 16 slides forward, the control valve devices 46 and 51 decrease the opening of the bleed passage 45.

In each of the above embodiments, the control valve device 4
6, 51 are configured to open and close both the air supply passages (18, 12a, 44), 54 and the bleed passage 45. In each of the above embodiments, the thrust bearing 32 is changed from a rolling bearing to a sliding bearing. Further, the thrust bearing 32 must be eliminated. That is,
By adopting the present invention, the thrust bearing 32
Since the capacity of the sliding bearing can be reduced, there is no problem even if it is changed to a sliding bearing which is assumed to have a smaller capacity than a rolling bearing with the same size. Furthermore, even if the thrust bearing 32 is deleted, for example, the inner wall surface of the front housing 11 (the front end surface of the bearing seat 11a) and the swash plate 31 (the front end surface of the boss portion 31a, which is rotatably supported in the third embodiment). The sliding problem between the front housing 11 and the swash plate 31 (rotary support 56) can be sufficiently solved by forming a lubricating coating made of a solid lubricant on each of the members 56).

In the first or second embodiment, the control valve device is arranged so that the average value of the thrust fluctuation load applied to the thrust bearing 32 is maintained at a value shifted by a predetermined value toward the front side or the rear side. Operate 46, 51.

The technical idea that can be grasped from the above embodiment will be described. (1) The piston-type compressor according to claim 3, wherein a part of the drive shaft (16) is used as a valve body (47).

In this manner, the number of parts can be reduced as compared with a configuration in which a valve body is provided separately from the drive shaft 16 and these are connected by any connecting member.
(2) The end on the valve / port forming body 14 side of the drive shaft 16 forms a valve body 47, and the surface of the valve body 47 facing the valve / port forming body 14 forms a blocking surface 47a.
7a or at least one of the shut-off faces 48 on the valve / port forming body 14 side facing the shut-off face 47a.
9. The piston type compressor according to (1), wherein 9 is formed.

In this way, problems such as deterioration of wear and increase in power loss of the compressor due to contact between the end of the drive shaft 16 and the valve / port forming body 14 can be more effectively solved. be able to.

[0065]

According to the present invention having the above structure, it is possible to preferably maintain the relationship between the pressure in the cylinder bore and the pressure in the crank chamber.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a single-headed piston type fixed displacement compressor.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a graph showing a thrust fluctuation load applied to a thrust bearing based on an operation of a compressor.

FIG. 4 is a longitudinal sectional view of a single-headed piston fixed displacement compressor showing a second embodiment.

FIG. 5 is a longitudinal sectional view of a single-head piston type variable displacement compressor showing a third embodiment.

FIG. 6 is a diagram showing a minimum discharge capacity state.

FIG. 7 is a longitudinal sectional view of a conventional single-head piston fixed displacement compressor.

[Explanation of symbols]

11 front housing constituting the housing, 12
... Similar cylinder block, 12a ... Accommodation chamber constituting air supply passage, 13 ... Rear housing constituting housing, 14 ... Valve / port formed body, 15 ... Crank chamber, 16
... Driving shaft, 18 ... Radial bearing forming an air supply passage with roller gap, 31 ... Swash plate as cam plate, 33
... Cylinder bore, 35 ... Piston, 37 ... Suction chamber as suction pressure area, 38 ... Discharge chamber as discharge pressure area
39: suction port, 40: discharge port, 41: suction valve,
Reference numeral 42 denotes a discharge valve, 44 denotes a communication hole constituting an air supply passage, 45
... bleed passage, 46 ... control valve device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryo Matsubara 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Taku Yasiya 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. F term in Toyota Industries Corporation (reference) 3H045 AA04 BA12 CA01 CA02 CA03 DA25 EA33 3H076 AA06 BB32 BB34 CC12 CC16 CC17 CC20 CC83

Claims (4)

[Claims] 1. A crank chamber and a cylinder bore are formed in a housing, and a drive shaft is rotatably held so as to pass through the crank chamber. In the crank chamber, a cam plate is integrally rotatable with the drive shaft. A single-headed piston connected to a cam plate is reciprocally housed in the cylinder bore; and a valve / port formation having a suction port, a suction valve, a discharge port, and a discharge valve corresponding to the cylinder bore in the housing. The body is disposed so as to close the cylinder bore with the piston, and the rotation of the drive shaft is converted into the reciprocation of the piston via the cam plate, whereby the gas is compressed in the cylinder bore. In the piston type compressor, the crank chamber and the discharge pressure region are communicated via an air supply passage. A control valve device that communicates with the suction chamber and the suction pressure region through a bleed passage, and that adjusts at least one of the supply passage and the bleed passage based on the amount of sliding movement of the drive shaft in the axial direction back and forth. In the case where the drive valve slides in the direction in which the piston approaches the valve / port forming body, the control valve device includes at least one of an air supply passage or a bleed passage on the side where the pressure in the crank chamber is reduced. When the drive shaft slides in a direction to separate the piston from the valve / port formation body, at least one of the air supply passage or the bleed passage is opened to increase the pressure in the crank chamber. A piston type compressor that adjusts the degree. 2. The piston type compressor according to claim 1, wherein the control valve device is configured to open and close at least an air supply passage. 3. The control valve device according to claim 1, further comprising a valve body connected to the drive shaft so as to be slidable integrally with the drive shaft to adjust an opening of at least one of an air supply passage and a bleed passage. 3. The piston type compressor according to 1 or 2. 4. An external control valve for adjusting an opening of at least one of an air supply passage and a bleed passage by electric drive; a movement amount detection sensor for detecting a slide movement amount of the drive shaft; 3. The piston compressor according to claim 1, further comprising a valve control unit that controls power supply to an external control valve based on a slide movement amount of the drive shaft detected by the movement amount detection sensor. 4.