JP3082993B2 - Variable capacity swash plate 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 variable displacement swash plate type compressor used in a vehicle air conditioner or the like.

[0002]

2. Description of the Related Art A conventional variable displacement type swash plate type compressor (hereinafter, referred to as a swash plate type compressor).
It is simply called a compressor. ).
The one disclosed in Japanese Patent Publication No. 2 is known. In this compressor, a rotary support is fitted and fixed to a drive shaft in a crank chamber, and an elongated hole is formed in a support arm protruding from the rotary support. A connecting pin is slidably guided in the elongated hole, and a rotary driving body is connected via the connecting pin so as to be tiltable in the front-rear direction. A swash plate is slidably attached to the rotary driver, and a piston rod is interposed between the swash plate and each of the pistons housed in the plurality of cylinder bores. Thus, in this compressor, the rotational motion of the drive shaft is converted into the oscillating motion of the swash plate via the rotational motion of the rotary driver, and the oscillating motion of the swash plate is converted into the reciprocating linear motion of each piston. It has become. Further, the inclination angle of the swash plate is controlled by the pressure in the crank chamber, whereby the stroke of the piston is changed, and thus the compression capacity is changed. At this time, since the tilting operation of the rotary driving body and the swash plate is regulated by the long holes formed in the support arm of the rotary support, the top clearance of the piston is always kept substantially constant at the end of the final compression stroke, The top position of the swash plate is prevented from being displaced back and forth regardless of the change in the inclination angle of the swash plate.

[0003]

However, in the conventional compressor, the swash plate acts on the swash plate via the piston and the piston rod when the inclination angle of the swash plate is maximized and the displacement of the compressor is maximized. The position of the point of action of the compression reaction force on the swash plate and the position of the fulcrum of the compression reaction force via the connecting pin in the elongated hole formed in the support arm of the rotary support are located on a straight line parallel to the drive shaft. It is designed to be. Therefore, as the inclination angle of the swash plate decreases, the fulcrum position of the compression reaction force via the connecting pin moves downward in the elongated hole, and the action point position on the swash plate receives the compression reaction force of the piston at the top position. Moves upward relative to the fulcrum position. As a result, the position of the point of action of the compression reaction force via the piston at the top position is farther from the drive shaft than the position of the fulcrum of the compression reaction force via the connecting pin, so the inclination angle of the swash plate is reduced based on the compression reaction force. Further, a moment for reducing the pressure is generated, and the operation of reducing the discharge capacity becomes sensitive due to the influence of the moment. On the other hand, since the operation of the swash plate in the direction of increasing the inclination angle is hindered by the moment, the operation of increasing the discharge capacity becomes dull, and the controllability of the discharge capacity as a whole is not always good.

In order to improve the controllability of the discharge capacity while maintaining the top clearance of the piston substantially constant, the inventors of the present application have developed a compressor having a hinge mechanism in which the fulcrum of the compression reaction force is not displaced. (Japanese Patent Application No. 3-241998). As shown in FIG. 7, the proposed hinge mechanism includes a pair of support arms 41A, 41B provided on a rotary support 42 so as to protrude rearward in a crank chamber formed by a cylinder block 45 and the like.
And a pair of guide arms 43A and 43B whose base ends are rotatably gripped in the front-rear direction and whose legs are slidably inserted into a pair of guide holes 43A and 43B provided on the swash plate side. And the guide pins 44A and 44B. The fulcrum position P ₁ in such a hinge mechanism,
P ₂ is present at the base end of the guide pins 44A, 44B rotatably gripped by the support arms 41A, 41B and does not displace.

[0005] By the way, there is no known compressor which has a damping action to perform a tilt displacement of a swash plate. In the above-described compressor, the guide holes 43A, 4
3B attaches the legs of the guide pins 44A and 44B to the crank chamber 4
The guide pins 44A and 44B are provided in the guide holes 43A and 43B when the swash plate returns to the maximum tilt angle and when the tilt angle is reduced from the maximum tilt angle.
With no resistance from B, the swash plate is likely to quickly return to the maximum tilt angle, or to rapidly decrease the tilt angle from the maximum tilt angle. Therefore, when the drive shaft 46 is rotated at a high speed and the capacity is controlled at a large capacity change speed, the capacity is returned to the maximum capacity and the capacity is reduced from the maximum capacity rapidly. Therefore, when this compressor is incorporated in a vehicle air conditioner, for example, hunting of the air conditioner occurs, and the control of the discharge temperature of the evaporator and the capacity of the compressor becomes unstable, making suitable air conditioning difficult. In some cases, the durability of the air conditioner including the compressor is impaired, and the driving feeling is sometimes deteriorated.

The present invention is a further improvement based on the above-mentioned proposal, which prevents the capacity control from being hindered by the moment based on the compression reaction while maintaining the piston top clearance substantially constant, and reduces the maximum capacity. It is an object of the present invention to solve the problem of slowly restoring and reducing the capacity from the maximum capacity.

[0007]

In order to solve the above-mentioned problems, a compressor according to the present invention comprises, as the hinge mechanism, a support arm provided on the rotary support so as to protrude rearward, and a grip of the support arm. And a guide pin whose base is slidably inserted into a guide hole provided on the swash plate side, and the guide hole is provided in the crank chamber. And a damping chamber having a pore communicating with the damping chamber and having a volume change caused by sliding of the guide pin.

[0008]

According to the compressor of the present invention, the guide pin is rotated in the front-rear direction with respect to the rotary support while the inclination angle of the swash plate is changed based on the pressure difference between the pressure in the crank chamber and the suction pressure. The swash plate tilts while sliding on the drive shaft so that its top position is maintained at a fixed position. Thus, the top clearance of the piston is always kept substantially constant regardless of the inclination angle of the swash plate.

In this compressor, since the base end of the guide pin is gripped by the support arm, the fulcrum position of the compression reaction force on the rotary support does not change even if the inclination angle of the swash plate changes. Therefore, a moment based on the compression reaction force via the piston can be prevented from being generated with respect to the swash plate, and the inhibition of the capacity control due to the moment based on the compression reaction force is prevented.

Furthermore, in this compressor, since the guide hole has a fine hole communicating with the crank chamber and has a damping chamber which causes a volume change by sliding of the guide pin, when the swash plate returns to the maximum inclination angle, At the time of decreasing the inclination from the maximum inclination, the guide pin receives the resistance force by discharging the refrigerant in the damping chamber from the small hole or sucking the refrigerant in the crank chamber into the small damping chamber through the small hole. As a result, the swash plate gradually returns to the maximum tilt angle, and gradually reduces the tilt angle from the maximum tilt angle. Therefore, even when the capacity control is performed at a large capacity change speed by rotating the drive shaft at a high speed, the return to the maximum capacity and the capacity reduction from the maximum capacity are performed slowly.

Incidentally, since there is a proportional relationship between the speed of change of the capacity and the resistance force of the damping chamber, if the drive shaft is rotated at a low speed and the capacity is controlled at a small speed of changing the capacity, the capacity of the damping chamber is reduced. There is little resistance and no hysteresis in the variable characteristics. For this reason, if the capacity change speed is low, excellent responsiveness is secured.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to FIGS. As shown in FIG. 1, a front housing 2 is joined to one end of a cylinder block 1,
A rear housing 3 is joined to the other end via a valve plate 4. A drive shaft 6 is accommodated in a crank chamber 5 formed by the cylinder block 1 and the front housing 2, and the drive shaft 6 is rotatably supported by a bearing 7. A plurality of cylinder bores 8 are bored at positions surrounding the drive shaft 6 in the cylinder block 1, and pistons 9 are fitted into the respective cylinder bores 8. The central axis of the piston 9 is parallel to the axis of the drive shaft 6.

In the crank chamber 5, a rotary support 10 is supported by the drive shaft 6 so as to be able to rotate synchronously with the drive shaft 6, and a spherical sleeve 11 is rotatably and slidably supported. A pressing spring 12 is interposed between the rotary support 10 and the spherical sleeve 11, and the pressing spring 12
Urges the spherical sleeve 11 toward the rear housing 3. On the spherical sleeve 11, a rotary driving body 13 formed in an annular shape so as to surround the spherical sleeve 11 is supported so as to be able to swing back and forth. When the pressing spring 12 shown in FIG. 1 is in the most contracted state, the contact surface 13a formed obliquely on the lower back surface of the rotary driving member 13 comes into contact with the rotary supporting member 10, and the inclination angle increases. Further tilt is regulated.

A ring-shaped support rail 14 centered on the axis of the drive shaft 6 is provided on both sides of the outer periphery of the rotary drive 13.
The swash plate 14 having a and 14a is fitted. Semi-cylindrical inner shoes 15, 15 having an axis in the circumferential direction are engaged with the support rails 14a, 14a.
The displacement of the swash plate 5 and 15 in the radial direction is restricted. A semi-cylindrical outer shoe 16, which is hollowed into a semi-cylindrical shape on the outer peripheral surface of the inner shoes 15,
The outer surfaces of the outer shoes 16 and 16 are engaged with opposed cylindrical hollow surfaces of the swash plate passage grooves 9 a formed in the neck of the piston 9. . Thus, the inner shoes 15, 15 are placed on the swash plate 14.
A plurality of pistons 9 moored via the outer shoes 16, 16 are housed in each cylinder bore 8 so as to be able to reciprocate.

On the other hand, as shown in FIG. 2, a substantially U-shaped bracket 17 protrudes from the rear surface of the rotary driving body 13 with the driving shaft 6 interposed therebetween. On the upper front surface of the rotary support 10, a pair of support arms 18 A, 18 B constituting a pair of hinge mechanisms K, K protrude rearward in the axial direction so as to face each end of the bracket 17. It is provided symmetrically with respect to the top dead center position. This support arm 1
8A and 18B each have a substantially rectangular gripping portion 1
8a, 18b are formed, and each gripper 18a, 18b is formed.
b has a circular hole 18c penetrating in the vertical direction at the center thereof,
8d are formed. The outer ring bush 1 having spherical concave portions 19a, 19b on the inner periphery in the circular holes 18c, 18d.
9A and 19B are prevented from coming off by the circlips 20A and 20B, and are fitted respectively. Each outer ring bush 1
Spherical concave portions 19a, 19b of 9A, 19B have spherical portions 21a, 21 as base ends of guide pins 21A, 21B.
b is rotatably and irremovably gripped by spherical contact.

Further, guide holes 22a and 22b are formed at the tip of the bracket 17 so that the bottom communicates with the crank chamber 10 through small holes 22c and 22d. Guide pins 21A and 21B are formed in these guide holes 22a and 22b. The rod-like portions 21c and 21d as the leg portions are slidably inserted. Each of the guide holes 22a and 22b has an attenuation chamber 22e or 22 at the lower end of which a volume change is caused by sliding of the rod portions 21c and 21d of the guide pins 21A and 21B.
f is formed.

As shown in FIG. 1, the inside of the rear housing 3 is divided into a suction chamber 24 and a discharge chamber 25 by a partition wall 23. A suction port 26 and a discharge port 27 are formed in the valve plate 4 so as to correspond to the respective cylinder bores 8.
The compression chamber 28 formed between the piston 9 and the suction port 2
6 and the discharge port 27 are connected to the suction chamber 24 and the discharge chamber 25. A suction valve 2 is provided at each suction port 26 and discharge port 27.
9 and a discharge valve 30 are provided, respectively.
Open and close. In addition, the rear housing 3 is provided with control valves 31 for adjusting the pressure of the crank chamber 5.

In the compressor configured as described above,
When the swash plate 14 rotates with the driving of the drive shaft 6, the inner shoes 15, 15 that engage with the pistons 9 via the outer shoes 16, 16, support the swash plate 14 with support rails 14a, 14a.
a in the circumferential direction, each piston 9
The refrigerant gas is reciprocated in the cylinder chamber 8, whereby the refrigerant gas is sucked from the suction chamber 24 into the cylinder bore 8, and the refrigerant gas is compressed.
It is discharged to the discharge chamber 25. At this time, the compression capacity of the refrigerant gas discharged to the discharge chamber 25 is controlled by adjusting the pressure in the crank chamber 5 by the control valves 31, 31.

That is, for example, if the pressure in the crank chamber 5 is reduced by adjusting the pressures of the control valves 31, 31, the back pressure acting on the piston 9 is reduced, and the inclination angle of the swash plate 14 is increased. That is, the spherical portions 21a, 21b of the guide pins 21A, 21B in each of the hinge mechanisms K, K slide on the spherical concave portions 19a, 19b of the outer race bushes 19A, 19B to swing the guide pins 21A, 21B forward. , The rotation driving body 13 swings forward around the spherical sleeve 11 and the spherical sleeve 11
And the guide pins 21A and 21B slide in a direction to enter the guide holes 22a and 22b, and the inclination angle of the swash plate 14 increases.

When the swash plate 14 returns to the maximum inclination angle, the guide pins 21A and 21B receive a resistance force due to the rod portions 21c and 21d discharging the refrigerant in the damping chambers 22e and 22f from the fine holes 22c and 22d. . Thereby, the swash plate 14
Gently returns to the maximum inclination as shown in FIG.
The outer shoes 16, 16 slide in the circumferential direction with respect to the inner shoes 15, 15, and also slide in the center direction in the swash plate passage groove 9a of the piston 9. For this reason, the stroke of the piston 9 is extended and the compression capacity is increased. Therefore, even if the capacity control is performed at a large capacity change speed by rotating the drive shaft 6 at a high speed, the return to the maximum capacity is performed gently. Then, when the inclination angle of the swash plate 14 is maximized, the compressor continues to operate at the maximum capacity.

Conversely, when the control valves 31, 31 shown in FIG. 1 close the crank chamber 5 and the suction chamber 24 to increase the pressure in the crank chamber 5 by blow-by gas, the piston 9
When the back pressure acting on the swash plate 14 increases, the inclination angle of the swash plate 14 decreases. That is, the spherical portions 21a, 21b of the guide pins 21A, 21B in each of the hinge mechanisms K, K slide on the spherical concave portions 19a, 19b of the outer race bushes 19A, 19B to swing the guide pins 21A, 21B backward. , The rotary driving body 13 swings rearward around the spherical sleeve 11 and the spherical sleeve 11
2 and the guide pins 21A, 21B
Slides in a direction to come out of the guide holes 22a and 22b,
The inclination angle of the swash plate 14 is reduced.

When the swash plate 14 reduces the inclination from the maximum inclination, the guide pins 21A and 21B are connected to the rods 21c and 21c.
d receives a resistance force by sucking the refrigerant in the crank chamber 5 into the damping chambers 22e and 22f through the fine holes 22c and 22d. Thereby, the swash plate 14 gradually reduces the inclination from the maximum inclination as shown in FIG. And
The outer shoes 16, 16 slide in the circumferential direction with respect to the inner shoes 15, 15, and slide outward in the swash plate passage groove 9a of the piston 9. For this reason, the stroke of the piston 9 is shortened, and the compression capacity is reduced. Therefore, even when the capacity is controlled at a large capacity change speed by rotating the drive shaft 6 at a high speed, the capacity is gradually decreased from the maximum capacity. Then, when the inclination angle of the swash plate 14 is minimized, the compressor continues to operate with the minimum capacity.

During each of these capacity operations, as shown in FIG.
Since there is a proportional relationship between the rate of change in capacity and the resistance force caused by the damping chambers 22e and 22f, if the drive shaft 6 is rotated at a low speed to perform capacity control at a small rate of change in capacity, the damping chamber 22e, The resistance force of 22f acts only slightly, and no hysteresis occurs in the variable characteristics. Therefore, if the rate of change in capacitance is low, excellent responsiveness is ensured.

At the time of each of these capacity operations, the guide pins 21A and 21B rotate in the front-rear direction with respect to the rotary support 10, and at the same time, the guide holes 22a and 22
The swash plate 14 is tilted while sliding on the drive shaft 6 so that the top position thereof is kept at a fixed position in order to slide in the inside b. Thereby, regardless of the inclination angle of the swash plate 14, the top clearance of the piston 9 is always kept substantially constant.

Further, since the spherical portions 21a, 21b of the guide pins 21A, 21B are gripped by the gripping portions 18a, 18b of the support arms 18A, 18B, even if the inclination angle of the swash plate 14 changes, the rotating support 10 Does not change. Therefore, no moment is generated on the swash plate 14 based on the compression reaction force via the piston 9, and the inhibition of the capacity control by the moment based on the compression reaction force is prevented.

In addition, in this compressor, the bracket 17
Are formed in a substantially U-shape on the back surface of the rotary driving body 13, so that the dynamic imbalance caused by the rotation of the rotary driving body 13 is appropriately absorbed by the bracket 17. Therefore, no vibration or the like occurs due to the change in the load balance, and the rotation of the rotary driving body 13 and the swash plate 14 is stabilized.

Therefore, in this compressor, the piston 9
In addition to preventing the capacity control from being hindered by the moment based on the compression reaction force while keeping the top clearance of the cylinder approximately constant, it is possible to return to the maximum capacity and maximize the capacity by means of a structurally simple means without installing special equipment. The capacity can be gradually reduced from the capacity. Although the small holes 22c and 22d are formed in the bracket 17 in the above embodiment, as shown in FIG. 6, a small hole 32a is formed in the guide pin 32, and the crank chamber 5 and the damping chamber 2 are formed by the small holes 32a.
2e may be communicated.

Further, both the inner and outer shoes 15, 1
6 instead of the connecting mechanism using the swash plate 14 and each piston 9
May be connected by a piston rod. Further, in the above-described embodiment, a compressor in which the swash plate 14 rotates in synchronization with the rotation of the drive shaft 6 is employed. The present invention can also be applied to a compressor of a type that employs a non-oscillating swash plate.

[0029]

As described above in detail, in the compressor of the present invention, the support arm is provided on the rotary support so as to protrude rearward, and the base of the support arm is rotated in the front-rear direction. Since the hinge mechanism is constituted by a guide pin slidably inserted into a guide hole provided on the side of the swash plate and movably gripped, the top clearance of the piston is kept substantially constant while the compression is maintained. Disturbance of capacity control due to the moment based on the reaction force can be prevented.

Further, in this compressor, since the guide hole of the hinge mechanism has a hole communicating with the crank chamber and has a damping chamber in which the volume changes due to sliding of the guide pin,
The return to the maximum capacity and the decrease in capacity from the maximum capacity can be performed gently. Therefore, when this compressor is incorporated in, for example, a vehicle air conditioner, hunting of the air conditioner is effectively suppressed. For this reason, the control of the blow-out temperature of the evaporator and the capacity of the compressor are stable, suitable air conditioning is facilitated, the durability of the air conditioner including the compressor is improved, and a suitable operation feeling is obtained. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a compressor according to an embodiment.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1 according to the compressor of the embodiment.

FIG. 3 is a cross-sectional view showing a hinge mechanism and the like at the time of a maximum tilt angle according to the compressor of the embodiment.

FIG. 4 is a cross-sectional view showing a hinge mechanism and the like at the time of a minimum inclination angle according to the compressor of the embodiment.

FIG. 5 is a graph showing a relationship between a capacity change speed and a resistance according to the compressor of the embodiment.

FIG. 6 is a cross-sectional view similar to FIG. 4, according to a compressor of another embodiment.

FIG. 7 is a sectional view similar to FIG. 2, according to the proposed compressor.

[Explanation of symbols]

1: Cylinder block 2: Front housing
3. Rear housing 5. Crank chamber 6. Drive shaft
8 ... Cylinder bore 9 ... Piston 10 ... Rotation support
13 ... Rotating drive 14 ... Swash plate K ... Hinge mechanism
11 Spherical sleeve 15, 16 Inner / outer shoe (connection mechanism) 17 Bracket 18A, 18B Support arm 18a, 18b
Holding parts 21A, 21B ... guide pins 21a, 21b ...
Spherical part (base end) 21c, 21d ... Rod-like part (leg) 22a, 22b ...
Guide holes 22c, 22d ... Pores 22e, 22f ...
Damping chamber

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04B 27/08 F04B 27/14

Claims (1)

(57) [Claims] A cylinder block is formed in a cylinder block, and a piston is housed in each cylinder bore so as to be able to reciprocate, and a rotation support member located in a crank chamber is synchronized with a drive shaft supported by a housing. The swash plate is rotatably supported, and the swash plate is pivotally supported via a hinge mechanism between the swash plate and the drive shaft via a sleeve between the swash plate and the piston. A coupling mechanism for converting the swinging motion of the swash plate into a reciprocating motion of each piston is interposed, and the compression capacity is changed by controlling the tilt angle of the swash plate by the pressure in the crank chamber. In the variable displacement type swash plate type compressor, the hinge mechanism may include a support arm provided on the rotary support so as to protrude rearward, and a grip portion of the support arm whose base end is rotatable in the front-rear direction. And a guide pin slidably inserted into a guide hole provided on the swash plate side, and the guide hole has a small hole communicating with the crank chamber and has a small hole. A variable displacement type swash plate compressor having a damping chamber in which a volume is changed by a slide.