JPS634038B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a sliding member, such as a swash plate of a swash plate compressor or a vane of a vane compressor, which is made of an aluminum-silicon alloy and comes into sliding contact with two or more members having different hardnesses. In general, a swash plate compressor has a swash plate 3 fitted onto a drive shaft 2 which is rotatably supported in a housing 1 as shown in FIG. A piston 5 is installed inside the piston 5 so as to be able to reciprocate, and a pair of hemispherical shoes 6 and 7 are engaged with spherical parts 5a and 5b, which are recessed to face each other inside the piston 5. The slopes 3a and 3b of the swash plate 3 are brought into sliding contact with the flat parts 6a and 7a, and the outer peripheral surface 3c of the swash plate 3 is connected to the end face 5d of a connecting part 5c connecting the head of the piston 5 as shown in FIG. It was in sliding contact with 5e. When the swash plate 3 is rotated by the drive shaft 2, the piston 5
is reciprocated within the cylinder bore 4 to effect compression. On the other hand, the swash plate 3 and the spherical parts 5a and 5b of the piston 5
The pair of shoes 6 and 7 interposed between them receive a large force during compression, so their Bitkers hardness H _v
Hard bearing steel (SUJ2) with a hardness of 650 or higher (hereinafter simply referred to as hardness _Hv ), tungsten-based high-speed steel (SKH9)
The swash plate 3 and the piston 5 are made of steel materials such as
are formed of an aluminum-silicon alloy containing 16% silicon (containing an aluminum base material 8, primary silicon grains 9, and eutectic silicon grains 9' as shown in FIGS. 3a and 3b).
Furthermore, the surface of the piston 5 is coated with a tetrafluoroethylene coating 1.
0 is coated, and the spherical parts 5a, 5b
Alternatively, wear of the end faces 5d and 5e is minimized to improve durability. However, the conventional swash plate 3 has high hardness (hardness H _v 1300～
1500), the exposure degree of the primary silicon grains was the same, so the conditions could not be said to be suitable for each member in mutual contact. In other words, if the degree of exposure of the primary silicon grains of the swash plate 3 is reduced to match the coating 10 of the piston 5, and the amount of exposed aluminum base material on the outer circumferential surface 3c and slopes 3a, 3b is increased, the hardness will decrease when lubrication is insufficient. Seizing occurs between the shoes with high hardness and the aluminum base material with low hardness, and in order to properly maintain the sliding movement between the shoes 6 and 7 and the swash plate 3, the degree of exposure of the primary silicon grains on the swash plate 3 is relatively reduced. When the temperature is increased, the coating 10 is easily scratched by the hard silicon grains and is easily worn, and after the coating is broken, the piston base material is damaged. Note that there is also a piston 5 in which the coating 10 is omitted, but in this case as well, the end surface 5
There was a defect that the wear and surface roughness of d and 5e became severe. The present invention was proposed in order to solve the above-mentioned conventional contradictions, and its purpose is to provide a compressor swash plate etc. made of an aluminum-silicon alloy that comes into sliding contact with two or more types of members having different hardness. An object of the present invention is to provide a sliding member that can improve seizure resistance and wear resistance by changing the degree of exposure of primary silicon grains depending on the hardness of the member that contacts the sliding surface of the sliding member. . Hereinafter, a first embodiment in which the present invention is embodied in a swash plate of a swash plate type compressor will be described with reference to FIGS. 1 to 3. In this embodiment, the degree of exposure of the primary silicon grains 9 on the slopes 3a, 3b which are in sliding contact with the shoes 6, 7 of the swash plate 3 is set to 60% as shown in FIG. The degree of exposure of the primary silicon grains 9 on the outer circumferential surface 3c in sliding contact is set to 10% or less, as shown in FIG. 3b. In addition, the surface hardness _Hv of Shoes 6 and 7 is
700 bearing steel (SUJ2), the piston is made of an aluminum-silicon alloy containing 12% silicon, and the outer circumferential surface is coated with an ethylene tetrafluoride coating 10, but this may be omitted. be. By the way, since the degree of exposure of the primary silicon grains 9 of the swash plate 3 cannot be changed during molding of the swash plate base material, it is processed to the above-mentioned ratio when finishing the base material. That is, in this embodiment, after machining the slopes 3a and 3b with a lathe, the machining allowance for final processing such as superfinishing is approximately 20μ to 40μ.
The degree of exposure of the primary silicon grains 9 is set to 10 to 60%, and the finishing allowance of the outer circumferential surface 3c is set to about 5 μ to 20 μ, so that the degree of exposure of the outer circumferential surface is 10% or less. Here, it is necessary to empirically know in advance the relationship between the finish machining allowance and the degree of exposure of the silicon grains, by taking advantage of the tendency that the silicon grains 9 tend to peel off when the finishing machining allowance is increased. Pre-processing may include milling in addition to lathe processing, and final finishing may include super-finishing, polishing,
There is paper polishing etc. Furthermore, when intermediate finishing and top finishing processes are included, the machining allowance for final finishing can be reduced. The slopes 3a, 3b of the swash plate 3 and the shoes 6, 7 with the above structure slide at high speed and under a high load, but even if metal contact occurs due to lack of lubrication, the primary silicon grains 9, which are harder than aluminum, can absorb the load. Because of this, the aluminum base material 8 is less likely to experience surface roughness or wear.
Furthermore, since the shoes 6 and 7 have sufficiently high hardness, surface roughness and wear caused by the primary silicon grains 9 are extremely reduced. Furthermore, the outer circumferential surface 3c of the swash plate 3 has end surfaces 5d and 5e.
Although it slides against the coating 10 at high speed and under a low load, the primary silicon grains are hardly exposed, so the coating 10 is not scratched and there is little wear. In this way, in the swash plate compressor of the above embodiment, the wear resistance or seizure resistance of the swash plate 3, piston 5, shoes 6, 7, and coating 10 is improved.
In order to prove this, a conventional compressor in which the degree of exposure of the primary silicon grains on the sliding surface of the swash plate 3 was kept constant everywhere, and a compressor according to the present invention were tested under the same conditions shown in Table 1. When tested, the results shown in Table 2 were obtained. In addition, in order to obtain results in a short time, this test is shown in Table 1.
As shown in Figure 2, by reducing the amount of oil and increasing the amount of gas compared to normal tests, and allowing the liquid to back up without any cooling load, the oil viscosity is extremely low, and the system is temporarily lubricated immediately after startup. It was carried out under extremely harsh conditions. As is clear from Table 2 below, the slope 3 of the swash plate
a,

【table】

[Table] In the case of a conventional swash plate in which the degree of exposure of primary silicon grains on both 3b and outer peripheral surface 3c is 60%, phenomena such as piston coating wear and an increase in streaks on the piston base material occur. Also, in the conventional swash plate in which the exposure degree of the slopes 3a, 3b and the outer circumferential surface 3c were both 10%, seizure occurred between the shoe and the swash plate. On the other hand, the swash plate of the present invention shows no abnormality, and even when the coating 10 was not applied to the piston, good results were obtained in that although there were some streaks on the outer peripheral surface 3c of the swash plate, there were no particular abnormalities. did it. Next, an embodiment in which the present invention is embodied in a vane compressor will be described with reference to FIGS. 4 and 5. Here, to describe the structure of the vane compressor, front and rear side plates 12 and 13 are fixedly connected to both end surfaces of a thick-walled horizontal cylindrical cylinder 11, and a front housing 14 is attached to the front surface of the front side plate 12. are fixedly connected to the front housing 14, and the cylinder 11 and both side plates 12, 13 are attached to the rear end surface of the front housing 14.
A rear housing 15 in the shape of a horizontal cylinder with a bottom is fixedly connected to the outer peripheral surface of the housing. A drive shaft 16 is rotatably supported at a position offset by a certain distance from the centers of the side plates 12, 13 and the front housing 14, and the drive shaft 16 has an intermediate portion that is partially connected to the inner peripheral surface of the cylinder 11. A cylindrical rotor 17 that slides in sliding contact with the inner surfaces of both side plates 12 and 13 is integrally fixed. A vane 18 is fitted into a plurality of vane grooves 17a provided on the outer circumferential surface of the rotor 17 so as to be retractable and protrusive, and the tip surface 18a of the vane 18 is in sliding contact with the inner circumferential surface of the cylinder 11, and both end surfaces 18b , 18c are side plates 1, respectively.
It is in sliding contact with the side surfaces of 2 and 13, and further has a ventral surface 18d,
The back surface 18e is in sliding contact with the plane of the vane groove 17a. On the other hand, the front side plate 12 has an inlet 1 provided through the outer periphery of the front housing 14.
A suction chamber 2 formed in the housing 14 from 9
The gas introduced into the cylinder 11, rotor 17, vane 18 and both side plates 12, 1
A suction hole 22 is provided therethrough to lead to a working chamber 21 formed by 3. Further, a discharge chamber 23 formed by cutting out the outer periphery of the cylinder 11 and the working chamber 21 communicate with each other through a discharge hole 24 and are normally closed by a check valve 25. The rear side plate 13 is provided with a passage 27 that communicates the discharge chamber 23 with the oil separation chamber 26 of the rear housing 15. , is transferred to the outside through a discharge port 29 provided on the outer periphery of the rear housing. Note that 30 is a passage for guiding oil to the end surface of the rotor 17. In this second embodiment, the vane 18 is a sliding member, and three types of members, the cylinder 11, both side plates 12 and 13, and the rotor 17, are in sliding contact with the vane 18. The composition and hardness _Hv of these members are as shown in Table 3.

[Table] Also, the tip surface 1 of the vane 18 that comes into sliding contact with the cylinder 11, side plates 12, 13, and rotor 17.
8a, both sides 18b, 18c and ventral (dorsal) surface 18
The experiment was conducted with the exposure degrees of the primary silicon grains in d and 18e as shown in Table 4. The tip surface 18a of the vane 18 is connected to the cylinder 11.
Since the pressure in the working chamber 21 and the pressure acting on the inner end surface of the vane cancel each other out, the vane slides into contact with the inner peripheral surface at high speed and with a low load. Therefore, even if the primary silicon grains are not exposed, there is little wear on the tip surface 18a, and the inner peripheral surface of the cylinder is also less likely to be damaged by the silicon grains. Also, the side surfaces 18b and 18c of the vane 18 are coated with the coating 1 of the front and rear side plates 12 and 13.
0 and sliding at high speed and low load, side surfaces 18b, 1
8c wear hardly occurs. Furthermore, since the degree of exposure of the primary silicon grains is low, the coating 10 is not damaged. Furthermore, the ventral (back) surfaces 18d, 18 of the vane 18
The point e slides at a low speed on the surface of the vane groove 17a of the rotor 17, but receives a large load, particularly at points P ₁ and P ₂ in FIG. 5, which are the edges. However, the vane belly (back) surfaces 18d and 18e
Since the degree of exposure of the primary silicon grains in is high, the large load can be received by the silicon grains and wear of the vane 18 can be reduced. Also, rotor 17
It is also very hard, so it won't be damaged by silicon particles. The vane compressor of this second embodiment and the conventional compressor in which the degree of exposure of the silicon grains of the vanes is the same in all parts are also under the conditions shown in Table 1 (however, the oil was 150 c.c.). When a test was conducted, the results shown in Table 4 were obtained.

[Table] It is clear from this result that the conventional vane (No.
), the cylinder, side plate, or belly (rear) surface of the vane is prone to wear, but the compressor using the vane of the present invention reduces wear on each part, improves durability, and prevents seizure. It can be seen that this can be prevented. In addition, in the first and second embodiments, the swash plate and vane of the compressor were described, but in addition to the compressor, a machine having a mechanism in which a member made of an aluminum-silicon alloy comes into sliding contact with two or more members of different hardness. If so, it is possible. In addition, if the silicon content percentage of the aluminum-silicon alloy is increased,
You can change the exposure amount throughout. As detailed above, the present invention provides two
By changing the degree of exposure of primary silicon grains on the sliding surface of a sliding member made of aluminum-silicon alloy that comes into sliding contact with more than one type of member, depending on the hardness of the member in relative contact with the sliding member and the sliding member. This has the effect of improving the wear resistance and seizure resistance of the members in contact with it.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical cross-sectional view of only the vicinity of the swash plate showing an example of a swash plate compressor, Fig. 2 is a cross-sectional view of the central part of the piston, and Fig. 3 a and b show the composition of the aluminum-silicon alloy. FIG. 4 is a longitudinal sectional view showing an embodiment of the present invention in a vane compressor, and FIG. 5 is a cross-sectional view of the same vane compressor. Swash plate...3, Slope...3a, 3b, Outer surface...
3c, Piston...5, Show...6,7, Aluminum base material...8, Primary silicon grains...9, Tetrafluoroethylene coating...10, Cylinder...1
1. Front and rear side plates...1
2, 13, Rotor...17, Vane groove...17
a, Vane...18, Tip surface...18a, Side end surface...18b, 18c, Ventral (dorsal) surface...18d, 1
8e.

Claims (1)

[Claims] 1. A sliding surface of a sliding member made of an aluminum-silicon alloy that comes into sliding contact with two or more types of members having different hardnesses, and varying the degree of exposure of primary silicon grains according to the hardness of the members in relative contact with each other. A sliding member that slides on two or more types of members in a compressor or the like. 2. The sliding member is a swash plate that slides on the piston and shoe of the swash plate compressor, and the degree of exposure of the primary silicon grains on the side surface of the swash plate that comes in sliding contact with the shoe is determined by A sliding member that slides with two or more types of members in a compressor or the like according to claim 1, wherein the exposure degree is higher than that of crystalline silicon grains. 3. The sliding member is a vane that comes into sliding contact with the cylinder, rotor, and side plate covering both end surfaces of the vane compressor, and the degree of exposure of the primary silicon grains on the sliding surface that comes into sliding contact with the rotor of the vane is determined by A sliding surface in sliding contact with two or more types of members in a compressor or the like according to claim 1, characterized in that the degree of exposure of the primary silicon grains on the sliding surface in sliding contact with the cylinder and the side plate is higher than that of the primary crystal silicon grains. Element.