JPS61201782A - Swash plate type compressor - Google Patents

Abstract

PURPOSE:To prevent the seizure of a shoe and to decrease driving power loss by forming the spherical-shaped sliding surface of a shoe of a lubricating film surface contg. a solid lubricating material and forming the plane-shaped sliding surface of the shoe of a hard layer surface. CONSTITUTION:A swash plate type compressor is constituted of a cylinder block 12 having plural pieces of cylinder ores 18 provided in parallel with a shaft 13, a swash plate 16 rotated by the shaft 13 therein, a piston 19 fitted freely slidably in the cylinder bores 18 and the shoe 24 which is interposed between the piston 19 or the ball sliding with the piston 19 and the sliding surface of the swash plate 16 and has the spherical-shaped sliding surface on one surface to move back and forth the piston 19 and the plane surface on the other surface. The spherical-shaped sliding surface of the shoe 24 is formed of the lubricating film surface contg. the solid lubricating agent and the plane- shaped sliding surface is formed of the hard layer surface having >=1,300 Vickers hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a swash plate compressor, particularly to an improvement of a shoe.

(Prior Art) Conventionally, for example, a self-help air conditioning system includes a cylinder block having a plurality of cylinder bores provided in parallel with an axis, a swash plate rotated by a rotating shaft within the cylinder block, and the like. A swash plate comprising a piston slidably fitted into the cylinder bore, and a shoe interposed between the piston and a sliding surface of the swash plate to cause the piston to reciprocate by rotation of the swash plate. A plate compressor is used. In this compressor, the swash plate swings and rotates due to the rotation of the rotating shaft, which causes the piston to reciprocate and compress the refrigerant in the cylinder.

In such conventional swash plate type compressors, in the case of a hemispherical shoe, the convex spherical vibrating surface is in sliding contact with the concave spherical surface of the piston, or in the case of a plate shoe, the concave spherical sliding surface is in sliding contact with the convex spherical surface of the pole. The surface is 1lW containing solid lubricant.
It is known that one film is formed on the surface of a single film (Japanese Patent Application Laid-open No.
7-146070) However, in a swash plate compressor, the circumferential speed on the flat sliding surface side of the shoe is usually 2 Qs at the maximum.
/5eC1, and the load received by the shoe is approximately 100~1
It has a large weight of 60 kg/ca+2, and even the conventional swash plate compressor described above has the disadvantage that its seizure resistance and abrasion resistance are not sufficiently good.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a swash plate type compressor with less power loss and improved seizure resistance.

(Means for Solving the Problems) In the swash plate compressor of the present invention, the cylinder block, swash plate, piston, etc. constituting the swash plate compressor may be the same as those of a conventional swash plate compressor.

One of the characteristics of the shoe that characterizes the swash plate compressor of the present invention is that the spherical sliding surface of the shoe is coated with a lubricating film containing a solid lubricant, as shown in FIGS. It is formed by the surface 4.41.

As the solid lubricant, molybdenum disulfide (MO82
), graphite (GR), boron nitride (BN), tungsten disulfide (WS t ), polytetrafluoroethylene resin (PTFE), and various other materials can be used. As is well known, most of the solid rIJ lubricants have a layered or flaky structure, and the lubricating effect is achieved by the slipperiness between the layers, but it is necessary to select the optimal lubricant depending on the usage conditions, purpose, etc.

The above-mentioned lubricating film is usually formed by coating the above-mentioned solid AlWj agent with a phenol resin, which is a thermosetting resin, as a binder on a desired sliding surface. Moreover, a film of soft metal such as lead or bismuth can also be used as this lubricating film. The thickness of this lubricating film is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less.

The surface of the lubricating film may be formed only on the spherical sliding surface of the shoe, for example, as shown in FIG. 2, or may be formed over the entire surface of the shoe.

The lubricating film may be formed on the surface of the base film 6 as shown in FIG.

This base film may be a chemical conversion film of not only manganese phosphate but also zinc phosphate or chromate, or a nitride film formed by soft nitriding treatment such as the tuftride method. Furthermore, as shown in FIG. 3, it is also possible to omit this base film itself.

The method for forming the above-mentioned lubricating film can be as follows.

First, the object to be treated is degreased with an alkaline solution or the like, and then a base film such as a manganese phosphate chemical conversion film is formed on its surface. In this case, add an accelerator as necessary to process rf
Aim to shorten lWl. After that, the coating material is applied by spraying, tamping, dipping, brushing, etc.
A lubricating film is formed by firing under predetermined conditions. The thickness of this lubricating film, together with the thickness of the base film, must be adjusted to a predetermined value or less in order to prevent operational noise caused by gaps created by this film. is preferred.

Furthermore, as another method for forming a lubricating film, for example,
There is also a method in which a diffusion layer of hexagonal iron sulfide with interwall properties is formed on the surface by low-temperature sulfurization treatment.

Further, the spherical sliding surface may be provided with a hole approximately at its center, as shown in FIG.

Another feature of the shoe that characterizes the swash plate compressor of the present invention is that, as shown in FIG. 2, the flat sliding surface 2 of the shoe is formed of a hard layer having a Vickers hardness of 1300 or more. ing.

This hard layer is formed by subjecting the base material to treatments such as boron-immersion, titanium carbide, vanadium carbide, etc.

It is preferable that the hardness is as large as possible. This hardness is greater than the hardness of the mating material. That is, the mating material is usually an aluminum-silicon alloy containing primary silicon having a hardness of f-1v 1000 to 1200.

The above-mentioned various curing methods are not particularly limited, but for example, boron-immersed treatment involves placing the product to be treated in powder or granules made by adding silicon carbide, potassium boron tetrafluoride, etc. to boron carbide (Ba C) and carbon. It is buried and heated at a predetermined temperature for a predetermined period of time.

The thickness of the hard layer is not particularly limited, but is usually 10 to
It is about 100μ.

The shape of the shoe may be a hemispherical shoe like the conventional one as shown in FIG. 1, or a flat plate member 25 as shown in FIG. It may be. This hemispherical shoe may be formed by cutting a steel ball into a hemispherical shape, or may be formed into a hemispherical shape by forging. The plate-shaped shoe is forged,
It may be formed by cutting, or may be formed by combining with a sintered body.

The flat surface of the shoe may be provided with a central hole 7.71 in its center, as shown in FIGS. 5 and 6, for example.

As shown in FIG. 7, this central hole is connected to the flat sliding surface 2 of the shoe and is formed by an opening surface 7a that expands into a funnel shape and an inner wall surface 7b that is connected to the opening surface 7a. Moreover, this central hole may have a bottom surface 7C that does not penetrate therethrough and is connected to the inner wall surface 7b as shown in FIG. 7, or it may penetrate therethrough. The former is advantageous in terms of oil retention.

[To form a central hole in the center of the IW sliding surface] of the shoe means to exclude the case where a large number of holes are dispersed and formed over almost the entire surface of the flat sliding surface of the shoe.

As shown in FIG. 7, the central hole 7 has a longitudinal magnification of 1
000, on a diagram showing the height of the flat sliding surface measured at a lateral magnification of 10, the flat sliding surface straight line m connecting the highest flat sliding surface on the cough diagram, and the flat sliding surface height measured at a lateral magnification of 10. Passing through the intersection of the straight line m', which is 20 mm lower in the figure and the wall surface 7b of the central hole, and parallel to the sliding surface straight line -, the intersection B between the flat side straight line m and the perpendicular axial straight line n, and the figure A ring-shaped space 9 having a cross section in which the reference distance connecting the intersection point C of the tangent M having an inclination of 45 degrees to the opening surface 7a above and the axial straight line n is 3III mm or more on the drawing. It is possible to have the following.

The above reference distance is 3IIIR or more, more preferably 4
■-That's it.

The shape of this opening surface may be, for example, a flat cross-sectional shape 71a as shown in FIG. 8, or a swollen curved shape 7 mm8 as shown in FIG. There may be.

Further, for example, the opening surface forming the central hole of the shoe and the inner wall surface may be smoothly continuous. In any case, the flat sliding surface 2 and the opening surface 7a can be smoothly continuous.

The central hole of the shoe is located at the center of the flat sliding surface of the shoe, and preferably has a bottomed space that is recessed from the flat sliding surface, but it may penetrate through the hole. This central hole primarily serves as a space for an oil reservoir. The size of the opening of the hole is determined in consideration of the width of the flat sliding surface of the shoe, the applied load, etc. The wider the opening of the central hole, the more convenient it is to supply lubricating oil to the flat sliding surface from the central hole.

Furthermore, if the center portion of the shoe is abnormally heated due to friction, the protrusion of the center portion due to thermal expansion is suppressed. but,
The wider the opening of the center hole, the smaller the opening area will be.
The load per unit sliding area increases. The opening area of the central hole is preferably about 1% to 20% of the flat vibration area.

For a shoe with a large flat sliding surface, such as a large swash plate compressor, a ring-shaped ring 10 is formed concentrically with the central hole, as shown in Figure 12. Good too. Alternatively, grooves 101 extending radially from the central hole 71 may be formed as shown in FIG. 13, the sliding surface of which is shown. However, as mentioned above, these grooves reduce the sliding area of this sliding surface, so care must be taken.

When forming the shoe by forging, the method for forming the center hole of the shoe is to provide a protrusion corresponding to the hole in a forging die, and form the hole at the same time as the shoe is forged and formed. be able to.

Alternatively, after the shoe is molded, the holes may be formed by pressing a press die in post-processing. Further, other drilling methods may be used such as cutting using a drill or lathe.

The shoe can be made from conventional structural materials such as metals and ceramics. Generally, the shoe is made of bearing steel (SLJJ2)
etc. are made from steel materials.

〔Example〕

The present invention will be explained below using examples.

(1) Evaluation of seizure load and power loss In this example, as shown in Table 1, a lubricating film was applied to the convex spherical sliding surface of the hemispherical shoe, and a lubricating film was applied to the convex spherical sliding surface of the flat-faced spherical shoe as shown in Figure 4. A hard layer 4 is formed over the entire shoe, and the hard layer 4 is
A base film 6 of manganese phosphate is formed on the convex spherical side of 4, and a lubricating film 5 containing molybdenum disulfide is formed on the base film 6.

Furthermore, as shown in FIG. 7, the hemispherical shoes of Nos. 091 to 3 have a diameter of 2 mm at the center of the flat sliding surface of the shoe.
．． It has a bottomed central hole 7 with a depth of 5 mm, a depth of mm mm, and a reference distance of 4 ms. Furthermore, the flat sliding surfaces of the No. 1 to 30 hemispherical shoes have a bulge with the middle high point located on the center hole side (approximately 1/3 a point), as shown in FIG. Note that 845G was used as the base material in all cases.

The method for forming the above-mentioned hard layer, base film, and lubricating film is as follows.

First, the hard layer of shoe No. 1 was formed by boron immersion treatment. That is, the base material was buried in a powder obtained by adding silicon carbide, potassium boron tetrafluoride KBF4, etc. to boron carbide BaCl carbon, and heated to 800 to 1000 DEG C. for 3 to 5 hours. This boron immersion treatment makes the outer layer boride-iron FeB,
As the inner layer, a surface layer (approximately 50 μm) consisting of 2 mm of diiron boride FezB was formed. The hardness of this hardened layer is Hv130
It was 0. In shoe No. 2, a hard layer (approximately 6μ
, HV2800). In the case of x-N013, a hard m (approximately 8μ, HV3500) was formed from vanadium carbide (VC) by a salt bath treatment method.

The method for forming the base film is as follows: First, the shoe to be treated is placed in an alkaline solution such as caustic soda at 60 to 70°C.
Degrease with water, then wash with hot water to remove alkali adhering to the surface. If only the convex spherical sliding surface of the degreased workpiece is immersed in an aqueous manganese phosphate solution at 85 to 95 DEG C., a manganese phosphate conversion coating (approximately 2 .mu.m) is formed on the surface as a base coating.

The method for forming the rIl slip coating is that once the manganese phosphate conversion coating is formed, it is washed and dried with hot water, and then molybdenum disulfide diluted with an appropriate diluent is applied to the convex spherical sliding surface. A coating material consisting of (Mo S t ), graphite, phenolic resin, etc. is applied by spraying. Then heat this at 180℃ for 30 minutes or 1
The desired lubricating film was formed by firing at 50° C. for 1 hour.

As shown in Table 1, Comparative Examples No. 0 mm to 4 were made using various materials of the flat vibrating surface having a predetermined hardness and shoes having a convex spherical sliding surface with or without the above-mentioned AM coating. Using.

The shoes of Examples Nos. 1 to 3 and Comparative Examples Nos. 091 to 4 shown in Table 1 above were tested for power loss and seizure load, and the results are shown in Table 1.

The above power loss measurement is based on a total displacement of 150cc/rev8.
It was actually installed in a swash plate type compressor and operated with the regular amount of refrigerant gas and lubricating oil.

The unit of this power loss value is expressed in horsepower per 1 ton of refrigeration.

The above seizure load test was conducted at: (1) Sliding speed was 15m7se.
(2) The load should be increased by 20 kg, and each load stage should last for 20 minutes. (3) The lubricating oil was 1 part refrigeration oil to 9 parts light oil, and the lubrication method was approximately 0
．． (4) The mating material is Al-16~18%5t-4~5%Cu-0,
45~0.65Mg arsyl alloy, straightness 2μ
Below, the roughness must be 0.6±0.2μ, (5
) The straightness of the shoe was 1 μ, and the roughness was 0.2 to 0.68.

According to the above test results (Table 1), this example No.
Shoe No. 3 has less power loss and larger seizure load than the shoes of Comparative Examples N001 to No. 4. That is, those having a hard layer with Hv of 1300 or more on the flat sliding surface (N
o, the seizure load of 1 to 3) is 52 o to 600 kg,
Each comparative example No. of Hv550.800, 1.2 (28
(0 to 400 kg). Moreover, the power loss of those having the above-mentioned lubricating film on the convex spherical sliding surface (No. 1 to 3) is 2.40.200 O at 1000 rpa+.
rpm is 2.63 to 2.65, and Comparative Example No. 33,4 which does not have this lubricating film (2.50 at 1000 rpm)
~2.52.200 Oram 2.75~2゜80)
significantly smaller compared to

The above examples and comparative examples all have a central hole, but the seizure load of the shoe without a central hole is approximately 360 ko, and the position of the mid-high point on the flat vibrating surface is:
Even around the point 1/3a shown in FIG. 10 or closer to the center hole, it shows similar good performance.

(2) Swash plate compressor The sectional view of the swash plate compressor according to the embodiment of the present invention is shown in the 14th
As shown in the figure. In FIG. 14, 12 is a cylinder block, and a rotating shaft 13 is rotatably supported in this cylinder block 12 via bearings 14 and 15, and a swash plate 16 is connected and fixed to this rotating shaft 13. has been done. The cylinder block 12 has a plurality of cylinder bores 18.
A piston 19 is slidably fitted into each bore 18 . The left end opening of the cylinder block 12 is closed by a valve plate 20 and a front cylinder head 21, and the right end opening is closed by a valve plate 22 and a rear cylinder head 23.

A spherical concave portion 19a is formed in the center portion of the piston 19. 24 is a hemispherical shoe, which has a convex spherical sliding surface j that connects to the spherical concave portion 19a of the piston 19, and a flat sliding surface that has a central hole 7 that is welded to the sliding surface of the swash plate 16. It has a surface 2. The above configuration is basically the same as that of a conventional swash plate compressor. The above (1) is applied to the convex spherical sliding surface of this shoe.
It has a lubricating film of No. 1, and the flat sliding surface of the cough shoe has No. 1 as described above.

When a sliding surface having a flat sliding surface shape such as a flat sliding surface is used, power loss is small and seizure resistance is good.

The shoe may be a hemispherical shoe as in the swash plate compressor of the above embodiment, but it may also be made up of a plate shoe 25 and a pole 26 as shown in FIG. 15. In this swash plate compressor, a plate member 25 is in sliding contact with the swash plate 16, and a pawl 26 is interposed between the spherical recess 19a of the piston 19 and the spherical recess of the plate member 25.

In this example, as in the previous embodiment, a lubricating film is formed on the concave spherical sliding surface of the plate member 25 of the shoe, and a central hole 71 for an oil reservoir is formed in the center of the flat sliding surface. is formed. Therefore, when a swash plate compressor is used in conditions where there is little lubricating oil, a certain amount of lubricating oil is supplied to the flat sliding surface of the shoe, and furthermore, when the swash plate compressor is operated for a long time under severe conditions, Even when the central part of the shoe becomes high temperature intensively and the flat sliding surface of the shoe protrudes due to thermal expansion, the central hole according to the present invention absorbs the thermal expansion and the flat sliding surface of the shoe protrudes. Reduce protrusion. This makes it difficult for local high loads to be applied to the center of the shoe. This makes it less likely to seize.

〔Effect of the invention〕

In the swash plate compressor of the present invention, the spherical sliding surface of the shoe is formed of a surface of a lubricating film containing a solid lubricant, and the flat surface sliding surface of the shoe that comes into sliding contact with the swash plate, which has the most severe sliding conditions. The surface is formed of a hard layer having a Witzkers hardness of 1300 or more. Therefore, in the present swash plate compressor, seizure of the shoes is prevented and power loss is small.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hemispherical shoe used in the swash plate compressor of the present invention. FIG. 2 is an enlarged sectional view of a main part of the hemispherical shoe shown in FIG. 1. FIG. 3 is an enlarged sectional view of a main part of another embodiment of the hemispherical shoe shown in FIG. 1. FIG. 4 is an enlarged sectional view of the main part of the hemispherical shoe used in this example. FIG. 5 is a sectional view of a hemispherical shoe with a central hole used in the swash plate compressor of the present invention. FIG. 6 is a sectional view of a plate shoe used in the swash plate compressor of the present invention. FIG. 7 is a perspective view showing a cross-sectional state of a main part of a typical shoe used in the swash plate compressor of the present invention. FIG. 8 is a cross-sectional view of a main part of a shoe according to the present invention having a central hole according to one embodiment, and FIG. 9 is a cross-sectional view of a main part of a shoe according to the present invention having a central hole according to another embodiment. be. FIG. 10 is a sectional view of a hemispherical shoe having a medium-height flat sliding surface used in this embodiment. Fig. mm is a plan view showing a flat sliding surface of a shoe used in the swash plate compressor of the present invention, which has another embodiment of the central hole. FIG. 12 is a plan view showing the sliding surface of another shoe, and FIG. 13 is a plan view showing the sliding surface of still another shoe. FIG. 14 is a sectional view of a swash plate compressor shown in an embodiment of the present invention. FIG. 15 is a sectional view of a swash plate compressor having a flat shoe. 1... Hemispherical shoe 2... Flat sliding surface 3... Convex spherical sliding surface 31... Concave spherical sliding surface 4... Hard layer 5... Lubricating film 6... Base film 7... Center hole 7a... Opening surface 7b...
Inner wall surface 7C...Bottom surface 8...Central axis 9...Ring-shaped space 10...Groove...Tangential line with an inclination of 45 degrees touching the opening surface L...Sliding surface straight line
m'... Straight line n parallel to m... Axial straight line A... Intersection of k and m B... Intersection of m and n C... Intersection of sentence and n

Claims (7)

[Claims] (1) A cylinder block having a plurality of cylinder bores provided parallel to the axis, a swash plate rotated by a rotating shaft within the cylinder block, and a piston slidably fitted into the cylinder bore; Interposed between the piston or a pole that slides on the piston and the sliding surface of the swash plate, one surface of which causes the piston to reciprocate as the swash plate rotates is a spherical sliding surface, and the other surface is a flat surface. A swash plate compressor comprising a shoe having a sliding surface, the spherical sliding surface of the shoe being formed of a surface of a lubricating film containing a solid lubricant, and the flat sliding surface of the shoe The surface has a Vickers hardness of 1
A swash plate compressor characterized by being formed of 300 or more hard layer surfaces. (2) The lubricating film is composed of at least one solid lubricant selected from molybdenum disulfide, boron nitride, graphite, and polytetrafluoroethylene, and a thermosetting resin binder such as epoxy resin or phenolic resin. A swash plate compressor according to claim 1, which is formed by combining two parts. (3) The lubricating film is coated via a base treatment film such as a manganese phosphate chemical conversion film or a zinc phosphate chemical conversion film, and the total thickness of the lubricating film and the base film is 10 μm.
A swash plate compressor according to the following claim 1. (4) The hard layer constituting the flat sliding surface is made of impregnated boron.
The swash plate compressor according to claim 1, which is formed by processing titanium carbide or vanadium carbide. (5) The swash plate type compressor according to claim 1, wherein the flat sliding surface of the shoe that comes into sliding contact with the swash plate has a central portion that is higher in height than a peripheral portion. (6) The flat sliding surface has a central hole in its center that is connected to the flat sliding surface and is formed by an opening surface that expands in a funnel shape and an inner wall surface that is connected to the opening surface. , The central hole has at least the highest sliding surface on the drawing showing the height of the sliding surface measured at a vertical magnification of 1000 and a horizontal magnification of 10, passing through the central axis on the inside of the opening surface. and an axial straight line that is perpendicular to the sliding surface straight line and passes through the intersection of a straight line parallel to the sliding surface straight line and 20 mm lower in the drawing and the wall surface of the central hole, A patent comprising a ring-shaped space having a cross section in which the reference distance connecting the intersection of a tangent line with an inclination of 45 degrees to the opening surface and the axial straight line on the drawing is 3 mm or more on the drawing. A swash plate compressor according to claim 1. (7) The opening surface of the central hole has an area of 1 to 20% of the total sliding area of the flat sliding surface.
The swash plate compressor described in Section 1.