JP3063375B2 - 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. ) Is disclosed in
The one disclosed in Japanese Patent Publication No. 2 is known. In this compressor, the rotary drive is connected to the rotary support fitted and fixed to the drive shaft via a connecting pin so as to be tiltable in the front-rear direction, and a swash plate is attached to the rotary drive. ing. A piston rod is interposed between each of the pistons housed in the plurality of cylinder bores and the swash plate, and converts the rotational motion of the rotary driving body into a reciprocating linear motion of each piston.

[0003] The support arm protruding from the rotating support has:
An elongated hole for slidingly guiding the connecting pin is formed.
Thereby, the tilting operation of the rotary driving body and the swash plate is allowed, and at the end of the final compression stroke, the top clearance of the piston is always kept substantially constant, and the top position of the swash plate is changed regardless of the change in the tilt angle of the swash plate. It is not displaced back and forth.

[0004]

In the above conventional compressor, when the dimensional accuracy of the arc-shaped long hole for guiding the hinge pin is low, the top clearance of the piston cannot be kept substantially constant, and the long hole and the hinge pin cannot be maintained. If the gap between the holes is large, abnormal noise is generated, but it is difficult to further increase the dimensional accuracy of the long holes.

However, in the conventional compressor, when the inclination angle of the swash plate is maximized and the displacement of the compressor is maximized, the swash plate of the compression reaction force acting on the swash plate via the piston and the piston rod. It is designed such that the position of the action point above and the fulcrum position of the compression reaction force via the hinge pin in the elongated hole are located on a straight line parallel to the drive shaft. Therefore, as the inclination angle of the swash plate decreases, the fulcrum position of the compression reaction force via the hinge pin moves downward in the elongated hole, and the action point position on the swash plate that receives the compression reaction force of the piston at the top position is changed. It 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 hinge pin. Moment occurs in order to further reduce the inclination angle, and the operation of reducing the discharge capacity becomes excessive due to the influence of this 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.

Therefore, the inventors of the present application have found that the top clearance of the piston can be kept substantially constant without causing the problem of abnormal noise and the like, and the fulcrum position of the compression reaction force has been improved in order to improve the controllability of the discharge capacity. Proposed a compressor equipped with a hinge mechanism that prevents the position from being displaced (Japanese Patent Application No. 3-24 / 1990).
1998 (not disclosed at the time of filing of the present application). As shown in FIG. 7, the proposed hinge mechanism includes a pair of support arms 41 provided on a rotating support (not shown) so as to protrude rearward.
A, 41B and a pair of guide holes 43A, 43 whose upper ends are rotatably held in the front-rear direction by the support arms 41A, 41B and whose lower ends are provided on the swash plate 42 side.
A pair of guide pins 44 slidably inserted through B
A, 44B. The fulcrum positions P ₁ and P ₂ in this hinge mechanism are located at the upper ends of the guide pins 44A and 44B rotatably gripped by the support arms 41A and 41B, and do not displace. In addition, guide pins 44A, 4
Since the upper end of 4B does not protrude outward from the support arms 41A and 41B, the support arms 41A and 41B and the inner wall of the cylinder block 45 can be provided close to each other, thereby reducing the body diameter of the compressor. It is possible to do.

However, since the reduction of the body diameter of the compressor directly leads to advantageous aspects such as downsizing and weight reduction of the compressor, the hinge mechanism is not sufficient from this point of view. Miniaturization is desired. The present invention is further improved based on the above proposal, and aims to improve the controllability of the discharge amount, and to solve the problem that the body diameter of the compressor can be further reduced. It is assumed that.

[0009]

In order to solve the above-mentioned problems, the present invention provides a hinge mechanism comprising: a support arm provided on a rotary support so as to protrude rearward; A guide pin slidably inserted into a guide hole provided on the swash plate side at a lower end thereof, and the hinge mechanism is configured so that the grip portion is located at a top dead center position of the swash plate. The gripping portion is formed so as to be symmetrical with respect to the left and right, and the gripping portion, which is substantially rectangular in the projection plane in the axial direction, is inclined so as to follow the arc drawn from the driving axis through the gripping portion. Is adopted.

[0010]

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

Unlike the conventional case, even if the inclination angle of the swash plate changes, the fulcrum position of the compression reaction force on the rotary support does not change. Therefore, the point of action of the compression reaction force on the swash plate and the position of the fulcrum can be set to be substantially the same distance from the drive shaft, and based on the compression reaction force via the piston with respect to the swash plate. Moment can be prevented from occurring. Therefore, the tilting of the swash plate in both the increasing and decreasing directions becomes smooth, and the control of the discharge capacity is improved.

Further, in the compressor of the present invention, the holding portion of the support arm constituting the hinge mechanism is obliquely inclined so as to follow the arc drawn through the holding portion from the drive shaft center. The distance from the drive shaft is substantially equal at both ends of the grip portion on both sides in the direction. Therefore, the inner wall of the cylinder block disposed outside the grip portion can be made closer to the grip portion, thereby making it possible to further reduce the body diameter of the compressor.

Further, the hinge mechanism is provided so that the gripping portions of the support arm are symmetrical with respect to the swash plate with respect to the top dead center position. The position of the other fulcrum is set within the range where each piston is located in the intermediate suction stroke.
Therefore, at one fulcrum position, each piston receives the resultant force of the compression reaction force acting on the swash plate, and at the other fulcrum position, each piston supports the suction force acting on the swash plate. Since each fulcrum position is not displaced in the rotation direction of the swash plate, the fulcrum position supports the resultant force of the compression reaction force and the suction force in cooperation. That is, the fulcrum positions cooperate and appropriately support the compression reaction force and the suction force while dividing the compression reaction force and the suction force. Therefore, no bending moment is generated due to the displacement of the swash plate in the rotation direction, and no unbalanced load acts on the sleeve.

[0014]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. As shown in FIG. 1, a front housing 2 is joined to one end of the cylinder block 1, and 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. The drive shaft 6 is mounted on the cylinder block 1.
A plurality of cylinder bores 8 are formed at positions surrounding the cylinder bores, 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 on 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. As shown in FIGS. 1 to 4, a rotary driving body 13 formed in an annular shape so as to surround the spherical sleeve 11 is supported on the spherical sleeve 11 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 13 a 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 increasing direction increases. Further tilt is regulated.

A ring-shaped support rail 14 centered on the axis of the drive shaft 6 is provided on both surfaces 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, a pair of brackets 17A and 17B are provided on the upper rear surface of the rotary driving body 13 so as to project in symmetrical positions with respect to the driving shaft 6. On the upper front surface of the rotary support 10, a pair of support arms 18A, 18B constituting a pair of hinge mechanisms K, K protrude rearward in the axial direction so as to face the brackets 17A, 17B. It is provided symmetrically with respect to the dead center position T. At each of the distal ends of the support arms 18A and 18B, grips 18a and 18b, which are substantially rectangular in the projection plane in the axial direction, are formed in an arc drawn from the axis of the drive shaft 6 through the grips 18a and 18b. It is formed obliquely to imitate. Each grip 18a, 18
b, a circular hole 18c penetrating in the vertical direction at the center thereof,
An outer ring bush 19A, 19B having spherical concave portions 19a, 19b on its inner periphery is fitted in the circular holes 18c, 18d, respectively, while being prevented from coming off by the circlips 20A, 20B. The spherical portions 21a, 21b of the guide pins 121, 21B are rotatably and irremovably gripped by spherical contact in the spherical concave portions 19a, 19b of the outer ring bushes 19A, 19B. Bosses 22A, 22B are provided at the distal ends of the brackets 17A, 17A of the rotary driving body 13, and guide holes 22a, 22B formed in the bosses 22A, 22B.
b, the rod portions 21c and 21d of the guide pins 21A and 21B
Are slidably inserted. Thus, the rotation support 10 and the rotation driving body 13 are connected to be able to rotate periodically via the two guide pins 21A and 21B regardless of the position of the spherical sleeve 11 on the driving shaft 6 and the inclination angle of the rotation driving body 13. Have been.

Each of the hinge mechanisms K, K thus constructed
Then, the fulcrum position P of the compression reaction force₁, P _Two(Fig. 1 shows the guide
The fulcrum position P corresponding to the pin 21A₁Only shows)
The spherical portions 21a, 21b of the doping pins 21A, 21B and the outer ring
With the spherical concave portions 19a, 19b of the brushes 19A, 19B.
A piston that is located between and corresponds to the top position of the swash plate 14
9 on the swash plate 14 via the compression force 9
And the fulcrum position P₁, P_TwoIs the center of the piston 9
Set to be located on the same virtual plane S including the axis
ing. That is, the fulcrum position corresponding to the guide pin 21A
Place P₁And a fulcrum position P corresponding to the guide pin 21B._TwoWhen
Of the piston 9 is always on the center axis of the piston 9.
It is set to be located in. Also, as shown in FIG.
U, one fulcrum position P₁Indicates that each piston 9 has an intermediate compression
And the other fulcrum position P_TwoIs
Each piston 9 is set within the range where it is located in the intermediate suction stroke.
Have been.

The interior of the rear housing 3 is partitioned by a partition wall 23 into a suction chamber 24 and a discharge chamber 25. 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. A compression chamber 28 formed between the valve plate 4 and the piston 9 is formed in the suction port 26.
And, it is communicated with the suction chamber 24 and the discharge chamber 25 through the discharge port 27. A suction valve 29 is provided at each suction port 26 and discharge port 27.
And a discharge valve 30, which open and close the suction port 26 and the discharge port 27 according to the reciprocating motion of the piston 9.

The rear housing 3 is provided with control valves 31 for adjusting the pressure in the crank chamber 5. In the compressor configured as described above, the drive shaft 6
When the swash plate 14 rotates with the driving of the inner shoe 15, the inner shoe 15, 1 engaged with each piston 9 via the outer shoe 16, 16.
5 slides circumferentially on the support rails 14a, 14a with respect to the swash plate 14, and each piston 9 reciprocates in the cylinder bore 8, whereby refrigerant gas is sucked from the suction chamber 24 into the cylinder bore 8, After the refrigerant gas is compressed, the discharge chamber 25
Is discharged to At this time, the compression capacity of the refrigerant gas discharged to the discharge chamber 25 is controlled by the control valves 31, 31.
It is controlled by adjusting the internal pressure.

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 hinge mechanism K, K slide on the spherical concave portions 19a, 19b of the outer race bushes 19A, 19B, thereby swinging the guide pins 21A, 21B forward. , The rotary driving body 13 swings forward around the spherical sleeve 11 and the spherical sleeve 11
2, 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. 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. Then, when the inclination angle of the swash plate 14 becomes maximum, the compressor continues to operate at the maximum capacity.

Conversely, if the pressure in the crank chamber 5 is increased by the blow-by gas due to the control valves 31, 31 closing the crank chamber 5 and the suction chamber 24, the back pressure acting on the piston 9 is increased. The inclination angle of the swash plate 14 is reduced. That is, the guide pin 2 in each hinge mechanism K, K
1A and 21B of the sphere portions 21a and 21b are the outer race bush 1
The guide pins 21A and 21B are swung rearward by sliding with the spherical concave portions 19a and 19b of 9A and 19B,
The rotation driving body 13 swings rearward around the spherical sleeve 11, and the spherical sleeve 11 retreats by the urging force of the pressing spring 12, and the guide pins 21A and 21B slide in a direction to come out of the guide holes 22a and 22b, The inclination angle of the swash plate 14 is reduced. The outer shoes 16, 16 slide in the circumferential direction with respect to the inner shoes 15, 15, and also 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. Then, when the inclination angle of the swash plate 14 becomes minimum, the compressor continues to operate with the minimum capacity.

[0023] During each of these displacement operation, receives a resultant force of the compression reaction force one support position P ₁ in which each piston 9 acts on the swash plate 14 via the two inner and outer shoes 15 and 16, the other support position P ₂ Each piston 9 has both inner and outer shoes 15, 16
Supports the suction force acting on the swash plate 14 via the swash plate. Since the fulcrum positions P ₁ and P ₂ are not displaced in the rotation direction of the swash plate 14, the fulcrum position supports the resultant force of the compression reaction force and the suction force in cooperation. That is, the fulcrum positions P ₁ and P ₂ cooperate and appropriately support the compression reaction force and the suction force while dividing the compression reaction force and the suction force. For this reason,
No bending moment is generated by the displacement of the swash plate 14 in the rotation direction, and no offset load acts on the spherical sleeve 11. That is, it is possible to smoothly swing the rotary driving body 13 that makes spherical contact with the outer peripheral surface. Therefore, in this compressor, unlike the conventional compressor, it is not necessary to receive the bending moment by the sleeve pin while oscillating the rotary driving body by the cylindrical contact by the sleeve pin, so that uneven wear of the spherical sleeve 11 can be avoided. Problems such as abnormal noise and durability can be solved.

The guide pins 21A and 21B rotate relative to the rotary support 10 while the guide holes 21A and 21B rotate with the inclination angle of the swash plate 14 based on the pressure difference between the pressure in the crank chamber 5 and the suction pressure. By sliding inside 22a, 22b,
The rotary driving body 13 tilts while sliding on the driving shaft 6 so that the top position of the swash plate 14 is maintained at a fixed position. Thereby, regardless of the inclination angle of the swash plate 14, the top clearance of the piston 9 is always kept substantially constant.

Even if the inclination angle of the swash plate 14 changes, the fulcrum positions P ₁ and P ₂ of the compression reaction force do not change in the radial direction of the drive shaft 6, so that the compression via the piston 9 at the top position. No rotational moment acting on the swash plate 14 based on the reaction force is generated. Thereby, the tilting of the swash plate 14 in both the increasing direction and the decreasing direction is smoothed, and the controllability of the discharge capacity is improved.

A centrifugal force acts on the guide pins 21A and 21B with the rotation of the drive shaft 6, and the centrifugal force is applied to the outer ring bush 19 where the spherical portions 21a and 21b come into spherical contact.
The swash plate 14 is not tilted in a specific direction due to the centrifugal force because the swash plate 14 is received by the support arms 18A and 18B via A and 19B. Therefore, the drive shaft 6
Even if the rotation speed increases and a large centrifugal force acts on the guide pins 21A and 21B, the controllability of the discharge capacity does not deteriorate. In particular, when this compressor is used as a compressor of an in-vehicle cooling device, in such a cooling device, as the rotation speed of the drive shaft 6 increases, the swash plate inclination angle is required to be reduced to reduce the discharge capacity. Also in this regard, preferable characteristics are obtained.

The guide pins 21A and 21B are formed such that the outer spherical portions 21a and 21b are supported by the support arms 18A and 18B.
B is rotatably held by B, and the inner rod portion 21b is configured to slide with respect to the guide holes 19a, 19b at a position as close to the drive shaft 6 as possible. The change in the load balance of the integrally rotating object of the drive shaft 6 due to the reciprocal sliding of 21B is extremely small. 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.

As described above, according to the compressor of the present embodiment, the guide pins 21A and 21B are supported by the support arms 18A and 18A.
8B is rotatably gripped by the gripping portions 18a, 18b, and does not protrude outward from the gripping portions 18a, 18b.
Each of the grips 18a, 18b is formed to be inclined so as to follow an arc drawn from the axis of the drive shaft 6 through the grips 18a, 18b, so that the grips 18a, 18b
, The inner wall of the cylinder block 1 can be arranged closer to the cylinder block 1, thereby further reducing the body diameter of the compressor.

In this case, the distance between the pair of hinge mechanisms K, K can be set wider, and by increasing the distance, the distance between the two fulcrum positions P ₁ , P ₂ can be increased, and The swinging motion of the plate 14 can be made more stable and smooth. The mounting structure of the support arm 18A and the guide pin 21A is not limited to the above-described embodiment. For example, as shown in FIG. A dynamic support hole 33a is provided, and a support shaft 34A is mounted in the rotation support hole 33a.
Supporting hole 36 formed in spherical portion 35a of guide pin 35A
The guide pin 35A may be supported on the support shaft 34A so as to be rotatable in the front-rear direction via A.

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, the compressor in which the swash plate 14 rotates in synchronization with the rotation of the drive shaft 6 is employed. The present invention is also applicable to a compressor of a type that employs a swinging swash plate that does not rotate.

[0031]

As described above in detail, according to the compressor of the present invention, the hinge mechanism has a support arm provided on the rotary support so as to protrude rearward, and an upper end provided on the holding portion of the support arm. Is formed so as to be rotatable in the front-rear direction, and the lower end thereof is formed of a guide pin slidably inserted into a guide hole provided on the swash plate side, so that the top clearance of the piston can be kept substantially constant. As well as
The tilting operation of the swash plate when the discharge capacity is increased and when the discharge capacity is decreased is both smoothed, and the controllability of the discharge capacity can be improved.

Since the holding portion of the support arm constituting the hinge mechanism is obliquely inclined so as to follow an arc drawn through the holding portion from the drive shaft center, the body diameter of the compressor is further reduced. Can be changed. Further, the hinge mechanism is provided in a double-symmetrical manner so that the grip portion is bilaterally symmetrical with respect to the top dead center position of the swash plate. Therefore, the compression reaction force and the suction force can be suitably received by the hinge mechanism. The burden on the sleeve can be reduced. Therefore, when this compressor is used in, for example, a vehicle air conditioner, uneven wear of the sleeve can be avoided, and problems such as abnormal noise and durability can be solved.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a partial plan view showing the vicinity of a rotary support of the compressor according to the embodiment.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a diagram illustrating a relationship between time and a position of a piston in the compressor of the embodiment.

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

FIG. 7 is a sectional view corresponding to FIG. 2 of a compressor according to the prior art.

[Explanation of symbols]

1: Cylinder block 2: Front housing
3. Rear housing 5. Crank chamber 6. Drive shaft 8. Cylinder bore
9 ... Piston 10 ... rotary support 13 ... rotary drive member 14 ... swash plate 17A, 17B ... bracket 18A, 18B ... support arms 21A, 21B ... guide pins 22a, 22b ... guide hole K ... hinge mechanism P _1, P ₂ ... Fulcrum position Q: action point position T: top dead center position

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tohru Takeichi 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27 / 08

Claims (1)

(57) [Claims] A housing includes a crank chamber, a suction chamber, a discharge chamber, and cylinder bores connected thereto. Each of the cylinder bores has a piston reciprocally housed therein, and a drive supported by the housing. A rotating support positioned in the crank chamber is supported on the shaft so as to be synchronously rotatable, and a swash plate is displaced at an inclination angle via a hinge mechanism between the rotating support and the drive shaft via a sleeve. A swash plate and a piston are interposed between the swash plate and the piston, and a connecting mechanism for converting a swinging motion of the swash plate into a reciprocating motion of each piston is provided between the swash plate and the piston. In the variable displacement swash plate type compressor configured to change a compression capacity by controlling a tilt angle, the hinge mechanism includes a support arm provided to protrude rearward on the rotating support, The upper end of the arm is gripped rotatably in the front-rear direction, and the lower end of the arm comprises a guide pin slidably inserted into a guide hole provided on the swash plate side, and the hinge mechanism is provided with the grip portion. Are provided so as to be symmetrical with respect to the top dead center position of the swash plate, and the gripping portion, which is substantially rectangular in the axial projection plane, is drawn from the driving axis through the gripping portion. A swash plate type variable displacement compressor characterized in that it is inclined so as to follow a circular arc.