JPH0979131A - Swash plate type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve installing performance, set work accuracy low, reduce a clearance, and reduce vibration and a noise. SOLUTION: A connecting mechanism R of a swash plate type compressor connected so as to convert miso braying rotary motion of a swash plate 11 into reciprocating rectilinear motion of a piston 13, is composed of a sliding shoe 15 having a spherical projecting surface 15b and a flat surface 15a to be fitted to a spherical recessed surface of an engaging member 18 and a contact bar 50 which is installed on an engaging member 19 and is formed as a spherical projecting surface so that the tip comes into contact with an end surface 11a of the swash plate 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate compressor, and more particularly to improvement of a connecting mechanism for connecting a swash plate and a piston.

[0002]

2. Description of the Related Art Conventionally, there is a swash plate compressor as a compressor used in an air conditioner for an automobile. This swash plate compressor is configured to reciprocally move a piston in an axial direction by a swash plate that makes a slurry rotational motion to compress a refrigerant.
There are a fixed-capacity type in which the inclination angle of the swash plate is fixed with respect to the drive shaft, and a variable-capacity type in which the inclination angle of the swash plate is changed with respect to the drive shaft.

A swash plate compressor with a variable capacity is shown in FIG.
As shown in FIG.
Is provided in the crank chamber 12 with a variable tilt angle, and the swash plate 11
The piston 13 and the rear end portion 14 of the piston 13 are connected via a connecting mechanism R having sliding shoes 15, 16, etc., and the swash-rotating motion of the swash plate 11 is converted into a reciprocating linear motion of the piston 13 in the cylinder chamber 17. At this time, the inclination angle of the swash plate 11 is changed, thereby adjusting the stroke amount of the piston 13 and changing the discharged refrigerant amount.

The sliding shoe 1 of this connecting mechanism R
As shown in FIG. 4, reference numerals 5 and 16 have flat surfaces 15a and 16a, respectively, which abut on both end surfaces 11a of the swash plate 11, and convex surfaces 15b and 16b which bulge into a substantially hemispherical shape. The flat surfaces 15a and 16a sandwich both end surfaces 11a of the swash plate 11, and the substantially hemispherical convex surfaces 15b and 16b are spherical recesses 18a and 19a of the engaging members 18 and 19 provided on the rear end 14 of the piston 13. Swash plate 1
The shaving rotation motion of 1 is converted into a reciprocating linear motion of the piston 13.

Therefore, the sliding shoes 15,
Since 16 must slide smoothly with respect to both front and rear end surfaces 11a of the swash plate 11, and the relationship between the piston 13 and the engaging members 18 and 19 must be maintained in the engaged state. It is molded with high precision of micron order.
Further, it is said that the sliding shoes 15 and 16 preferably have the same shape for ease of manufacturing.

[0006] Such sliding shoes 15, 1
In order for 6 to smoothly convert the swash rotation motion of the swash plate 11 into the reciprocating linear motion of the piston 13, both sliding shoes 15 and 16 have a point O on the central axis of the swash plate 11 as the center O. It is said that they must be arranged so as to substantially form a sphere (Japanese Patent Publication No. 64-1668).
Reference).

[0007]

However, both sliding shoes 15 and 16 are attached to the engaging member 18 of the piston 13.
Between 19 points, a point on the central axis of the swash plate 11 is centered O
Assembling so as to form a substantially spherical body is extremely troublesome work.

In addition, the connecting mechanism R of the swash plate 11 and the piston 13 has a pair of sliding shoes 15 and 16
And both end surfaces 11a of the swash plate 11 and the engaging members 18 and 19
There is also a problem in that a large number of spherical concave portions 18a and 19a must be molded with high precision.

Further, the swash plate 11 and the sliding shoe 1
When 5 and 16 are assembled between the engaging members 18 and 19, it is unavoidable that a certain amount of clearance is generated there, and this clearance also causes generation of abnormal noise.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a swash plate type compressor which has a good assembling property, can be set with a low processing accuracy, has a small gap, and can reduce vibration and noise. Especially.

[0011]

The invention according to claim 1 which achieves the above object, is connected to a crank chamber, a swash plate arranged in the crank chamber, and the swash plate rotated by a shaft, respectively. A plurality of pistons that are linearly reciprocally provided in the cylinder chamber, and a bifurcated engagement member that is formed at the rear end of the piston and in which the swash plate is located.
In a swash plate compressor of a single-headed piston having a coupling mechanism that couples the engaging member and the swash plate so as to convert the swash plate sledding rotational movement into reciprocating linear motion of the piston, the coupling mechanism is An abutting rod, which is attached to one of the engaging members and has a spherical convex surface so that its tip abuts one end surface of the swash plate, and a spherical concave surface formed on the other of the engaging members. It is characterized by comprising a spherical convex surface and a sliding shoe having a flat surface slidably in contact with the other end surface of the swash plate.

According to a second aspect of the present invention, in the connecting mechanism, the contact rod is attached to one of the engaging members so as to be movable back and forth. According to a third aspect of the present invention, in the coupling mechanism, a spherical convex surface formed at a tip of the contact rod contacts an end surface of the swash plate opposite to the compression side end surface, and the sliding shoe contacts the compression side end surface. The feature is that they are in contact with each other. According to a fourth aspect of the present invention, the swash plate is supported by the shaft via a hinge mechanism so that the inclination angle changes within a predetermined range according to the pressure in the crank chamber adjusted by the pressure adjusting means. It is characterized by

[0013]

According to the present invention having the above-mentioned structure, the contact rod and the contact rod are fitted with the sliding shoe fitted to the spherical concave surface of the engaging member formed at the rear end of the piston. If the swash plate is attached to the sliding shoe so that the swash plate is located between the sliding shoe and the sliding shoe, the connecting mechanism can be assembled without dropping the sliding shoe, and the assembling workability is significantly improved. In this case, as in the invention described in claim 2, when the contact rod is attached to one of the engaging members so as to be movable back and forth, for example, by screwing the contact rod into the engaging member, Since the sliding shoe fitted in the spherical concave surface can be pressed through the swash plate, the assembling work of the connecting mechanism is further facilitated, and there is no gap between the engaging member, the sliding shoe and the swash plate. Vibration and noise caused by the gap can be significantly reduced. If the generation of the gap can be prevented, it is not necessary to finish the spherical concave portion, the sliding shoe, the swash plate, and the like of the engaging member forming the coupling mechanism with extremely high precision, and the precision can be lowered to some extent. Further, as in the invention described in claim 3, the sliding shoe contacts the compression-side end surface so that the spherical convex surface of the contact rod tip contacts the anti-compression-side end surface of the end surface of the swash plate. Then, when the swash plate is rotated and the piston is linearly moved back and forth, the compression reaction force, which is a large force, is supported by the sliding shoe having a relatively large area, and the piston inertia force of a small force is generated by the contact rod. I will support you. Even when the connecting mechanism is incorporated in the compressor of variable capacity in which the inclination angle of the swash plate changes as described in claim 4, the swash plate is supported without a gap by the spherical convex surface of the contact rod tip and the sliding shoe. As a result, it is also easy to assemble, the machining accuracy can be set to a low level, and it can be assembled without gaps.As a result, vibration and noise can be reduced, sliding shoes do not fall off, and swash plate rotation is possible. Can be smoothly converted into the reciprocating motion of the piston.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a variable displacement swash plate compressor according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of FIG. 1. The same members as those shown in FIGS. The code is attached.

The variable capacity swash plate compressor shown in FIG. 1 has a cylinder chamber 17 on the right end side of the cylinder casing 20.
A cylinder block 21 in which is formed is provided, and a front housing 22 is provided in an opening portion on the left end side. A through hole 23 for inserting the shaft 10 is formed in a central portion of the front housing 22, and a radial bearing 24 for rotatably supporting the shaft 10 is press-fitted into the through hole 23 and is in close proximity thereto. Then, the oil seal 25 is arranged.

A crank chamber 12 is provided between the inner wall of the front housing 22 and the cylinder block 21, and the shaft 10 in the crank chamber 12 is provided with a long hole 26b at a front end portion thereof on the front housing side. The arm 26 is fitted.

A spherical bush 28 is provided on the shaft 10 so as to be slidable on the shaft 10 via a spring 27 between the shaft 10 and the rotary arm 26. The inner peripheral surface 11b of the opened center hole 11a is slidably abutted.

Further, on the back surface of the swash plate 11, a rotary arm 2 is provided.
6 is provided with a driven arm 29 projecting toward the tip portion 26a, and a hole 29b corresponding to the elongated hole 26b is opened, and the pin 30 is inserted through the elongated hole 26b and the hole 29b. Are configured.

A thrust bearing 31t is provided between the inner wall surface of the front housing 22 and the rotary arm 26.

The other end of the shaft 10 is projected to the cylinder block 21 and is rotatably supported by a radial bearing 31r. Further, an adjusting screw 34 is provided on the end surface of the shaft 10 via a thrust bearing 32 and a leaf spring 33. Has been.

A plurality of pistons 13 are provided on the swash plate 11, and the swash plate 11 and each piston 13 are connected by a connecting mechanism R.

This connecting mechanism R is a flat surface 1 that is finished so as to slide on the compression-side end surface 11a of the swash plate 11.
5a and a sliding shoe 15 having a spherical convex surface 15b that engages with the engaging member 18 of the piston 13 in a concavo-convex manner,
The tip of the swash plate 11 is attached to the engaging member 19
The contact rod 50 has a spherical convex surface 50a that abuts a, and the swash plate 11 is adapted to convert the swaying rotary motion into a reciprocating linear motion of the piston.

That is, the rear end portion 14 of the piston 13 is provided with bifurcated engaging members 18 and 19, and as shown in FIG. 2, one engaging member 18 has a spherical recess 18a on its inner surface.
The semi-spherical convex surface 15b of the sliding shoe 15 is fitted into the spherical concave portion 18a, and the flat surface 15a of the sliding shoe 15 is fitted to the end surface 11 of the swash plate 11.
a. The other engaging member 19
Is provided with a screw hole 51 orthogonal to the engaging member 19,
The screw portion 52 of the contact rod 50 is screwed into the screw hole 51,
A nut 53 is screwed on the rear end of the contact rod 50 to hold the contact rod 50 in position.

The contact rod 50 is formed into a spherical convex surface 50a so that the tip thereof comes into point contact with the end surface 11a of the swash plate 11 on the side opposite to the compression side. The radius of curvature r1 of the spherical convex surface 50a is the sliding shoe 15 described above. It is considerably smaller than the radius of curvature r2 of.

The magnitudes of the radii of curvature r1 and r2 take into consideration the force received by the abutment rod 50 and the sliding shoe 15 from the piston 13. That is, the side that receives a large compression reaction force generated when the piston 13 moves forward and compresses the refrigerant (hereinafter referred to as the compression side) supports this with the sliding shoe 15 having a large area, and the relatively small amount that occurs when the piston retracts. The spherical convex surface 50a of the contact rod 50 supports the side that receives the piston inertial force (hereinafter, anti-compression side).

Generally, the force acting on the coupling mechanism is the compression reaction force generated when the piston 13 advances and compresses the refrigerant,
Although the piston inertial force generated when the piston retracts, the compression reaction force of the former is about 300 to 400.
While the force is as large as kg, the value of the piston inertial force is about 30 kg, which is about 1/10 of the compression reaction force.

Therefore, the compression side against a large compression reaction force is supported by the sliding shoe 15 having a large area, and the anti-compression side against a small piston inertia force is supported by the spherical convex surface 50a of the contact rod 50 having a small area. By doing so, the compressor that favorably supports the force received from the piston 13 is provided.

In order to smoothly convert the slewing rotary motion of the swash plate 11 on which such a force is applied to the reciprocating motion of the piston 13, the center of the radius of curvature r2 of the sliding shoe 15 and the spherical convex surface of the abutment rod 50 can be converted. It is preferable that the centers of the radii of curvature r1 of 54 are at the same point O.

Note that this center coincidence does not have to be a problem for a fixed displacement compressor.

Further, on one end surface of the silicid chamber 17,
A valve in which a suction hole 35 for sucking the refrigerant and a discharge hole 36 for discharging the refrigerant are opened, and a suction valve and a discharge valve are formed so as to control the flow of the refrigerant to the suction hole 35 and the discharge hole 36. The plate 37 is provided, and the compressed refrigerant is
The return refrigerant is introduced from the discharge valve portion of the valve plate 37 into the discharge chamber 38, and the return refrigerant flows from the suction chamber 39 into the valve plate 3.
The suction valve portion 7 is introduced into the cylinder chamber 17.

Further, a control valve Cv for adjusting the pressure state in the crank chamber 12 and adjusting the inclination angle of the swash plate 11 is installed in the communication passage 40 of the cylinder block 21. The communication passage 40 communicates the suction chamber 39 with the crank chamber 12.

The control valve Cv is provided with a valve seat portion 41 on the crank chamber 12 side of the communication passage 40, and the valve seat portion 41 is a needle valve provided at the tip of a bellows 43 filled with gas of a predetermined pressure. It is designed to be opened and closed by 42.

Next, the operation will be described. First, in order to assemble the connecting mechanism R in the variable displacement compressor, the hemispherical convex surface 15b of the sliding shoe 15 is fitted to the spherical concave surface 18a of the engaging member 18 formed at the rear end portion 14 of the piston 13. , So that the swash plate 11 is located between the contact rod 50 and the sliding shoe 15.
When attached to, the sliding mechanism 15 can be assembled very easily without dropping the sliding shoe 15.

In this case, the contact rod 5 is engaged with the engaging member 19.
When 0 is temporarily set to the retracted position, and the sliding shoe 15 and the swash plate 11 are assembled and then moved forward, not only the sliding shoe 15 can be easily attached, but also the sliding shoe 15 and the swash plate 11 are attached. Alternatively, between the engaging members 18 and 19 of the piston 13, the swash plate 1
1 and the tip spherical convex surface 50a of the contact rod 50, there can be almost no gap, and operation with less vibration and noise is possible.

Next, the operation of the compressor will be described. An electromagnetic clutch (not shown) is turned on, and the shaft 10 causes the engine to pass through a belt and a pulley (both not shown).
When it is rotated by, the rotating arm 26 rotates accordingly, and the swash plate 11 also rotates via the hinge mechanism H. If the swash plate 11 is inclined with respect to the shaft 10, the swash plate 1
1, the piston 23 reciprocates, and the piston 23 reciprocates accordingly, and the refrigerant sucked into the cylinder chamber 17 from the suction hole 35 is compressed and discharged from the discharge hole 36 to the discharge chamber 38.
Is discharged.

It should be noted that the sliding shoe 15 and the contact rod 50 have the end surface 11 of the swash plate 11 even if the swash plate 11 rotates.
Since it only slides on a and 11a, the piston 13
The rotational force of the swash plate 11 is converted into the reciprocating motion of the piston 13 without transmitting the rotational force to the piston 13.

Here, the heat load in the cooling cycle is
When the temperature is higher than the preset temperature, the suction pressure of the refrigerant is high, the pressure of the refrigerant returning to the suction chamber 39 is also high, and the pressure in the communication passage 40 communicating with the suction chamber 39 is also high. Become.

Since the bellows 43 in the communication passage 40 is gas-filled so as to have a pressure slightly higher than the suction pressure corresponding to a predetermined set temperature, if the heat load is higher than the set temperature, The bellows 43 contracts, the needle valve 42 separates from the valve seat portion 41, the suction chamber 39 and the crank chamber 12 communicate with each other, and the pressure in the crank chamber 12 becomes substantially equal to the pressure in the suction chamber 27.

Therefore, even in the piston 13 in the suction process, there is almost no pressure difference between the front and rear, and the piston 13 can be smoothly retracted in the cylinder chamber 17, and the stroke of the piston 13 due to the moment around the hinge mechanism H. Increase.

That is, since the swash plate 11 is provided with a plurality of pistons 13 at equal angular intervals, a reaction force due to refrigerant compression is applied to the swash plate 11 from the piston 13 in the compression stroke, and each piston 13 is provided. A moment M1 acts around the hinge mechanism H by the reaction force acting on. Since this moment M1 is larger due to the piston 13 located farther from the pin 30 of the swash plate 11,
Acts clockwise at.

The moment M2 acts counterclockwise due to the elastic force of the spring 27. Furthermore, the crank chamber 12
There is also a moment M3 caused by the pressure difference between the suction chamber 39 and the suction chamber 39. However, this moment M3 can be ignored because the pressure in the suction chamber 39 and the pressure in the crank chamber 1a are almost equal.

Here, the elastic force of the spring 27 is M1> M2
Therefore, the tilt angle of the swash plate 11 is increased by the moment acting clockwise about the hinge mechanism H. The swash plate 10 is inclined until the pin 30 of the hinge mechanism H contacts the upper end of the elongated hole 26b.

As a result, the stroke of the piston 13 increases, the amount of discharged refrigerant increases, the amount of refrigerant circulating in the cooling cycle increases, and an appropriate amount of refrigerant is discharged according to the heat load, and the suction pressure of the compressor is increased. Will gradually fall, and will eventually be maintained at a constant suction pressure.

Next, when the heat load in the cooling cycle becomes small or the refrigerant becomes excessive due to the high-speed rotation of the compressor, the pressure of the return refrigerant is not sufficient to obtain a superheat amount, and the refrigerant is returned at a low pressure and sucked. The pressure in the chamber 39 decreases.

As a result, the pressure in the communication passage 40 also decreases, the bellows 43 expands, the needle valve 42 closes the valve seat portion 41, and the suction chamber 39 and the crank chamber 12 are shut off.

As a result, the pressure in the crank chamber 12 rises due to the blow-by gas leaking from the cylinder chamber 17 to the crank chamber 12 due to the compression of the compressor, and the above-mentioned moment becomes M1 <M2 + M3 at a certain point.
The tilt angle of the swash plate 11 decreases due to the moment acting counterclockwise about the hinge mechanism H. Therefore, the stroke of the piston 13 becomes smaller and the amount of discharged refrigerant decreases.

When the swash plate 11 is thus rotated to linearly move the piston back and forth, the compression-side end surface 11 of the swash plate 11 is moved.
The sliding shoe 15 is used to a.
If 1a is abutted and supported by the tip spherical convex surface 50a of the abutment rod 50, a large compression reaction force generated at the time of piston compression is mainly received by the sliding shoe 15, and a small piston inertia force generated at the time of piston retraction is mainly at the anti-compression side. The abutting rod 50 of the above is received, and the rotation of the swash plate 11 is smoothly converted into the reciprocating motion of the piston 13.

In this case, the contact rod 50 is pushed between the sliding shoe 15, the swash plate 11 and the engaging members 18 and 19 of the piston 13, and between the swash plate 11 and the tip spherical convex surface 50a of the contact rod 50. Because there is almost no gap due to pressure,
Operation with less vibration and noise is possible.

The present invention is not limited to the above-described embodiments, but can be variously modified within the scope of the claims. For example, the coupling mechanism according to the above-described embodiment relates to a variable displacement compressor, but not limited to this, a coupling mechanism for a fixed displacement compressor with a single-head piston can also be implemented.

Further, in the variable displacement compressor, a control valve having a structure in which a gas of a predetermined pressure is enclosed in the bellows is used as the adjusting means for adjusting the pressure in the crank chamber 12. The present invention is not limited to this, but the bellows expands and contracts according to the suction pressure, and this operation opens and closes the valve to introduce high-pressure discharge pressure into the crank chamber 12 and at the same time cut off communication to the suction chamber, Of reducing the discharge pressure of the crank chamber and communicating the crank chamber with the suction chamber to lower the pressure of the crank chamber, or a method of electronically controlling the pressure introduced into the crank chamber 12 according to the heat load of the refrigeration cycle. The thing etc. can also be used. Further, it is also possible to use a system in which the suction chamber and the crank chamber are always in communication with each other by an orifice and the amount of high pressure discharge pressure introduced into the crank chamber is controlled.

Further, in the above embodiment, the contact rod 50 is engaged with the engaging member 19 so as to be mounted so as to be movable back and forth in the axial direction. However, the contact rod 50 does not necessarily have to be movable back and forth. Instead, it may be fixed to the engaging member 19 by caulking or an adhesive agent.

[0052]

As described above, according to the present invention, the connecting mechanism can be assembled without dropping the sliding shoe, and the assembling workability is remarkably improved. According to the invention as set forth in claim 2, there is little gap between the engaging member, the sliding shoe, and the swash plate, and the vibration and noise caused by the gap can be significantly reduced. It is not necessary to finish the spherical concave portion, the sliding shoe, the swash plate, and the like with extremely high precision, and the precision can be lowered to some extent. According to the third aspect of the invention, the compressor has a preferable state of force received from the piston. According to the invention of claim 4,
Even when the connecting mechanism is incorporated in a variable displacement compressor whose tilt angle of the swash plate changes, the swash plate can be supported without gaps by the spherical convex surface of the abutting rod tip and the sliding shoe. It is easy to set, processing accuracy is low, and it can be assembled without gaps. As a result,
Vibration and noise can be reduced, and the rotation of the swash plate can be smoothly converted into the reciprocating motion of the piston without the sliding shoe falling off.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a variable capacity swash plate compressor according to an embodiment of the present invention.

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

FIG. 3 is a schematic cross-sectional view of a conventional variable displacement swash plate compressor.

FIG. 4 is an enlarged view of a main part of the compressor.

[Explanation of symbols]

10 ... Shaft, 11 ... Swash plate, 11a ... End face of swash plate, 12 ... Crank chamber, 13 ... Piston,
14 ... rear end of piston, 15 ... sliding shoe, 15a ... flat surface of sliding shoe, 1
5b ... Sliding shoe spherical convex surface, 17 ... Cylinder chamber, 18, 19 ... Engaging member, 18a ... Spherical concave surface, 50 ... Abutment rod, 50a ... Abutment rod spherical convex surface, Cv ... Pressure adjusting means, H ... Hinge mechanism,
O ... center, R ... connection mechanism.

Claims (4)

[Claims] 1. A crank chamber (12), a swash plate (11) arranged in the crank chamber (12), and a swash plate (11) rotated by a shaft (10), each of which is connected to a cylinder chamber. A plurality of pistons (13) provided for reciprocating linear movement in (17),
The swash plate is formed inside the piston (13) at the rear end (14).
A bifurcated engaging member (18, 19) in which (11) is located, and the engaging member (18, 19) and the swash plate (11) are rubbed only by the swash plate (11) to oscillate a rotary motion. (13) In a swash plate compressor of a single-headed piston having a connecting mechanism (R) for connecting so as to convert to a reciprocating linear motion, the connecting mechanism (R) is attached to one of the engaging members (18, 19). An abutting rod (50) which is attached and whose tip is a spherical convex surface (50a) so as to abut one end surface (11a) of the swash plate (11);
A spherical concave surface (18) formed on the other side of the engaging members (18, 19)
It is composed of a spherical convex surface (15b) fitted to (a) and a sliding shoe (15) having a flat surface (15a) slidably in contact with the other end surface (11a) of the swash plate (11). A swash plate compressor with a single-headed piston. 2. The slant according to claim 1, wherein the connecting mechanism (R) has the contact rod (50) attached to one of the engaging members (18, 19) so as to be movable back and forth. Plate compressor. 3. The connecting mechanism (R) has a spherical convex surface formed at the tip of the contact rod (50) on the end surface (11a) of the anti-compression side of the end surface (11a) of the swash plate (11). (50a) abuts, compression side end face
The swash plate compressor according to claim 1 or 2, wherein the sliding shoe (15) is in contact with the (11a). 4. The hinge mechanism for the swash plate (11) so that the inclination angle changes within a predetermined range according to the pressure in the crank chamber (12) adjusted by the pressure adjusting means (Cv).
The swash plate compressor according to any one of claims 1 to 3, which is supported by the shaft (10) through (H).