JP2002089439A - Swash plate compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swash plate compressor realizing weight reduction. SOLUTION: This compressor is provided with a housing 1, 2, 4 formed with a cylinder bore 1a, a crank chamber 2a, a suction chamber 4a, and a delivery chamber 4b partitioned in the inside, a piston 6 received movably to reciprocate in the cylinder bore 1a, a drive shaft 5 driven by an external drive source to be supported rotatably to the housing 1, 2, 4, a swash plate 8 supported synchronously rotatably relating to the drive shaft 5, and a shoe 9a, 9b paired before/behind the swash plate 8 to make the piston 6 driven. The shoe 9a, 9b is mainly constituted by a magnesium system material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type compressor used for a vehicle air conditioning system or the like.

[0002]

2. Description of the Related Art A refrigerating circuit used in an air conditioning system for a vehicle incorporates a compressor for compressing a refrigerant gas. The compressor includes a fixed displacement type compressor and a variable displacement type compressor. More specifically, the fixed displacement compressor includes a one-side swash plate type and a double-head swash plate type. Variable displacement compressors include one-sided swash plate type and double-headed swash plate type.

[0003] Of these compressors, a general swash plate type compressor has a cylinder bore, a crank chamber,
A suction chamber and a discharge chamber are defined, and a piston is accommodated in each cylinder bore so as to reciprocate. The drive shaft rotatably supported by the housing is driven by an external drive source such as an engine, and a swash plate is supported on the drive shaft so as to be synchronously rotatable. A pair of shoes for driving the piston are provided before and after the swash plate.

If the swash plate is provided at a constant inclination with respect to the drive shaft, it is a fixed displacement swash plate compressor. Further, if a swash plate is provided so that the inclination angle can be displaced with respect to the drive shaft, and if the inclination can be displaced by adjusting the pressure in the crank chamber by the control valve, the discharge capacity can be adjusted, then it is a variable displacement type inclination It is a plate type compressor. On the other hand, if the piston is a single-headed piston having a head only at one of the front and rear sides of the swash plate, it is a one-sided swash plate compressor, and if the piston is a double-headed piston having a head at both front and rear of the swash plate, It is a double-headed swash plate compressor.

In such a swash plate compressor, when the drive shaft is driven by an external drive source, the swash plate rotates synchronously, so that the piston reciprocates in the cylinder bore via the shoe. As a result, the cylinder bore forms a compression chamber between the piston and the head of the piston. Therefore, when the compression chamber is in the suction stroke, low-pressure refrigerant gas is supplied to the compression chamber from the suction chamber connected to the evaporator of the refrigeration circuit. When the compression chamber is in the compression stroke, high-pressure refrigerant gas is discharged from the compression chamber to the discharge chamber. The discharge chamber is connected to the condenser of the refrigeration circuit, and the refrigeration circuit is used for air conditioning of the vehicle as a vehicle air conditioning system. During this time, in the swash plate type compressor, the slidability of a sliding contact portion such as between the swash plate and the shoe is ensured by the mist-like lubricating oil contained in the refrigerant gas.

[0006]

However, the conventional swash plate type compressor has a disadvantage that the shoe is mainly made of an iron-based material such as SUJ2 of JIS, so that the weight is large. Such a defect is the same regardless of whether the compressor is a fixed displacement type swash plate type compressor or a variable displacement type swash plate type compressor. The same applies to a single-sided swash plate type compressor using a single-headed piston or a double-headed swash plate type compressor using a double-headed piston.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and has as an object to solve the problem of providing a swash plate type compressor which realizes weight reduction.

[0008]

SUMMARY OF THE INVENTION A swash plate compressor according to the present invention includes a housing defining therein a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber, a piston reciprocally housed in the cylinder bore. A drive shaft driven by an external drive source and rotatably supported by the housing; a swash plate supported rotatably in synchronization with the drive shaft; Swash plate type compressor comprising: a shoe for driving the shoe; and wherein the shoe is mainly formed of a magnesium-based material.

The swash plate compressor of the present invention has a small weight because the shoe is mainly made of a magnesium-based material.

Examples of magnesium-based materials (magnesium and a magnesium alloy containing the largest amount of magnesium; hereinafter the same) are JIS AZ91, ZK60,
WE43 or the like can be adopted.

The shoe can be composed of a shoe base made of a magnesium-based material, and a coating formed on the surface of the shoe base to improve slidability. As this coating, the following (1) to (8) can be adopted. That is, (1) a sprayed layer of a metal such as a copper-based material or an aluminum-based material (which means aluminum and an aluminum alloy containing the largest amount of aluminum; the same applies hereinafter) and the like, and (2) a copper-based material , A sintered layer of a metal such as an aluminum-based material capable of improving the slidability,
(3) Polyamide imide (PAI), polyimide (P
1) such as polyetheretherketone (PEEK)
A solid lubricant such as molybdenum disulfide (MoS ₂ ), graphite, tungsten disulfide (WS ₂ ), boron nitride (BN), polytetrafluoroethylene (PTFE) is used in a resin having heat resistance at 30 ° C. or more. Dispersed coating layer, (4) tin plating, nickel-phosphorus plating, nickel-boron plating, nickel-phosphorus-boron plating, nickel-phosphorus-boron-tungsten plating, nickel-phosphorus-boron-tungsten-chromium plating, (5) titanium nitride (TiN), chromium nitride (CrN), titanium-aluminum-nitrite (TiAl)
N) and other materials capable of improving slidability by chemical vapor deposition (CV
D) or an ion plating layer formed by physical vapor deposition (PVD), (6) diamond-like carbon (DLC)
And (7) ceramic coat and (8) alumite. Such a coating has a flat portion that is in sliding contact with the swash plate,
The same may be the same as the spherical portion slidingly contacting the piston, or may be different. When a coating is not formed on the flat or spherical portion of the shoe base material, it is preferable that the flat or spherical portion is subjected to quench hardening or the like.

If a coating for improving the slidability is formed on the surface of the swash plate or the shoe seat of the piston, the coating formed on the shoe base may be selected from the above (1) to (8). Different ones can be adopted.

In the swash plate compressor according to the present invention, the swash plate is provided so as to be displaceable at an angle with respect to the drive shaft, and the displacement is adjusted by adjusting the pressure in the crank chamber with a control valve to thereby displace the inclination. This is particularly effective when the capacity is variable. That is, since the shoe is mainly made of a magnesium-based material, the inertial force of the shoe acting in the direction of increasing the inclination angle is reduced, and the high-speed controllability is improved.

The swash plate type compressor of the present invention is particularly effective when the piston is a single-headed piston having a head only at one of the front and rear sides of the swash plate, that is, a single-sided swash plate type compressor. In this case, whether the one-sided swash plate type compressor is a fixed displacement type compressor or a variable displacement type compressor, excellent durability can be exhibited under severe conditions.

That is, in the single-sided swash plate type compressor, as shown in FIG. 3, an inertial force F1 based on the weight of the shoe 92a is applied to the center of gravity G of the shoe 92a on the front surface located at the bottom dead center of the swash plate 91. Acts in the axial direction. For this reason, shoe 9
2a, a moment is generated around the front side edge A of the swash plate 91, and the shoe 92a is inclined by a small angle θ with respect to the front surface of the swash plate 91 due to the gap between the shoe 93 and the front shoe seat of the piston 93. Becomes As a result, the shoe 92a has an inertial force F1 from the center of gravity G, a normal force F2 acting vertically on the front side edge A shifted to the outer peripheral side of the swash plate 91 by Δ from the normal position, and a resultant force of these forces. Force F as reaction force
3 works. That is, the shoe 92a is the piston 9
3 receives a force F3 at a position B in contact with the shoe seat on the front side. Since the inertial force F1 varies depending on the specific gravity of the shoe 92a and the rotation speed of the drive shaft, the normal force F2 also varies depending on the specific gravity of the shoe 92a and the rotation speed of the drive shaft. For this reason, JIS SUJ2 with a large specific gravity
When the shoe 92a is mainly made of an iron-based material such as the above, the mass of the shoe 92a is large, and the swash plate 91 is easily worn especially at the front side edge A. When the swash plate 91 in which the coating for improving the slidability is formed on the swash plate base is used, the coating is easily worn. On the other hand, when the shoe 92a is mainly composed of a magnesium-based material having a small specific gravity, the mass of the shoe 92a is small, and the swash plate 91, especially the coating, is hardly worn.

Further, the rear shoe 92b is pressed against the swash plate 91 with a load corresponding to the rotation angle. At this time, a differential pressure based on a differential pressure between the pressure in the compression chamber and the pressure in the crank chamber is applied to the rear shoe 92b,
The inertial force based on the own weight of b is acting, and the resultant force of the differential pressure and the inertial force is the load. Although the differential pressure is not different depending on the specific gravity of the shoe 92b, the inertia force is
Since a difference occurs in the specific gravity of b, the load with which the rear shoe 92b is pressed against the swash plate 91 differs depending on the specific gravity of the shoe 92b. This load changes depending on the rotation angle, and as shown in FIG. 4, the load becomes 0 or minus (rearward) at the beginning of a certain angle range α between the top dead center T and the bottom dead center U. When the rear shoe 92b separates from the swash plate 91 and the load becomes plus (forward) at the end of the angle range α, the rear shoe 9b
2b collides with the swash plate 91. Here, the energy E at the time when the shoe 92b collides with the swash plate 91 is as follows, where m is the mass of the shoe 92b, and v is the speed of the shoe 92b.

[0017]

(Equation 1)

Thus, the energy E varies depending on the mass of the shoe 92b.

For this reason, SUJ2 of JIS having a large specific gravity
When the shoe 92b is mainly made of an iron-based material such as the above, since the mass of the shoe 92b is large, the energy when the shoe 92b collides with the swash plate 91 is large, and the swash plate, especially the coating, is easily worn. On the other hand, when the shoe 92b is mainly composed of a magnesium-based material having a small specific gravity, the mass of the shoe 92b is small, so that the energy when the shoe 92b collides with the swash plate 91 is small, and the swash plate, especially the coating is worn. hard.

Therefore, in this one side swash plate type compressor,
More excellent durability can be exhibited.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

The variable displacement single-sided swash plate type compressor (hereinafter, simply referred to as a compressor) of the embodiment is, as shown in FIG.
A front housing 2 is coupled to the front end of the cylinder block 1, and the cylinder block 1 and the front housing 2
A crank chamber 2a is formed therein. A rear housing 4 is connected to a rear end of the cylinder block 1 via a valve mechanism 3 including a suction valve, a valve plate, a discharge valve, and a retainer. In the rear housing 4, a suction chamber 4a and a discharge chamber 4b are formed. I have. The suction chamber 4a is connected to an evaporator not shown, and the evaporator is connected to a condenser not shown via an expansion valve not shown, and the condenser is connected to the discharge chamber 4b.

A drive shaft 5 is rotatably supported on the front housing 2 and the cylinder block 1 via bearing devices 2b, 1b. The drive shaft 5 is mounted on the cylinder block 1.
A plurality of cylinder bores 1a are formed in parallel with the axis of
A single-headed piston 6 is reciprocally accommodated in each cylinder bore 1a.

A rotor 7 is fixed to the drive shaft 5 so as to be rotatable in the crank chamber 2a through a bearing device 2c between the drive shaft 5 and the front housing 2. The rotor 7 has a pair of hinge mechanisms K
The swash plate 8 is provided so as to be able to swing through. The swash plate 8 is provided with a through hole 8a, and the drive shaft 5 is inserted into the through hole 8a while allowing the swash plate 8 to swing. The swash plate 8 is provided with a pair of front and rear shoes 9a and 9b, and the piston 6 is moored to each pair of shoes 9a and 9b.

The rear housing 4 has a suction chamber 4 therein.
a, a control valve 10 connected to the discharge chamber 4b and the crank chamber 2a. By adjusting the pressure in the crank chamber 2a by the control valve 10, the inclination of the swash plate 8 is displaced, so that the discharge capacity can be adjusted.

In the compressor of the above embodiment, as shown in FIG. 2, the swash plate 8 is made of a swash plate base material 18 made of an iron-based material.
a and coatings 18b and 18c made of aluminum sprayed and resin-coated on the front and rear surfaces of the swash plate base 18a. The front and rear shoes 9a and 9b are
The shoe base 19a is made of a magnesium-based material, and the coatings 19b and 19c made of Ni-P-B-W-P plating are formed on the flat and spherical portions of the shoe base 19a. Further, the piston 6 has a piston base 16a made of an aluminum-based material and a coating 1 made of tin plating formed on a shoe seat of the piston base 16a.
6b.

Here, the iron-based material of the swash plate substrate 18a is S
UJ2. Aluminum spraying is a sprayed layer using an Al-Si alloy as an aluminum-based material. The resin coat is a coating layer in which MoS ₂ and graphite are dispersed in PAI. The symbol + indicates that the right coating is formed on the left coating. Further, the magnesium-based material of the shoe base 19a is an Mg-Al alloy, for example, AZ91. Further, the aluminum-based material of the piston base material 16a is an Al-Si alloy, for example, A403.
2. ADC12.

The compressor constructed as described above has a small weight because the shoes 9a and 9b are mainly composed of a magnesium-based material having a specific gravity of about 1.8.

In this compressor, the shoes 9a, 9b
Has a small energy when it collides with the swash plate 8 and the mass of the shoes 9a, 9b is small, so that the coatings 18b, 18c on the swash plate base 18a are not easily worn. For this reason, in this compressor, more excellent durability can be exhibited.

Further, in this compressor, the shoes 9a, 9
Since b is mainly made of a magnesium-based material, the shoes 9a and 9b act in a direction to increase the inclination angle.
Inertia force is small, and high-speed controllability is improved.

In this compressor, a shoe 9 sliding with a piston 6 mainly made of an aluminum material is used.
Since a and 9b are mainly composed of a magnesium-based material, it is possible to reliably prevent seizure due to a so-called scallop phenomenon.

[Brief description of the drawings]

FIG. 1 is a sectional view of a variable displacement single-sided swash plate type compressor according to an embodiment.

FIG. 2 is an enlarged sectional view of a main part of the variable displacement single-sided swash plate type compressor according to the embodiment.

FIG. 3 relates to a general variable displacement type one-sided swash plate type compressor;
It is a principal part enlarged explanatory view of a swash plate, a shoe, and a piston.

FIG. 4 relates to a general variable displacement single-sided swash plate type compressor;
It is the schematic plan view which looked at the swash plate from the axial back.

[Explanation of symbols]

1a: Cylinder bore 2a: Crank chamber 4a: Suction chamber 4b: Discharge chamber 1, 2, 4 ... Housing (1: cylinder block, 2 ...)
Front housing, 4 Rear housing) 6 Piston 5 Drive shaft 8 Swash plate 9a, 9b Shoe 19a Shoe base material 19b, 19c Film 10 Control valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Ajikawa 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside the Toyota Industries Corporation (72) Inventor Masahiro Kawaguchi 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Shares Inside Toyota Industries Corporation (72) Inventor Manabu Sugiura 2-1-1 Toyota-machi, Kariya City, Aichi Prefecture F-term inside Toyota Industries Corporation 3H076 AA06 BB38 CC12 CC20 CC33

Claims (4)

[Claims] 1. A housing defining therein a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber, a piston housed reciprocally in the cylinder bore, and driven by an external drive source to be rotatable by the housing. A swash plate compressor comprising: a drive shaft supported by a swash plate; a swash plate supported so as to be able to rotate synchronously with the drive shaft; The swash plate compressor, wherein the shoe is mainly formed of a magnesium-based material. 2. The shoe according to claim 1, wherein the shoe comprises a shoe base made of a magnesium-based material and a coating formed on the surface of the shoe base to improve slidability. Swash plate type compressor. 3. The swash plate is provided so as to be displaceable at an angle with respect to the drive shaft, and the displacement is adjustable by adjusting the pressure in the crank chamber by a control valve to adjust the displacement. The swash plate type compressor according to claim 1. 4. The piston according to claim 1, wherein the piston is a single-headed piston having a head only at one of front and rear sides of a swash plate.
4. The swash plate compressor according to 2 or 3.