JPS63147976A - Swash plate type motion converting device - Google Patents

Abstract

PURPOSE:To reduce noise by forming a slidable member cooperating with a piston, of aluminum-silicon group alloy so that the difference in thermal expansion coefficient between the swash plate material and the piston material is set to be less than 20%. CONSTITUTION:A piston 5 is reciprocated by a swash plate 2 attached to the piston, a slipper 3 and a ball 4. The slipper 3 is made of aluminum-silicon group alloy containing 8-18wt% of silicon which is made into eutectic silicon particles having an averaged particle size of less than 5mum by plastic working. The difference in thermal expansion coefficient between the material of the swash plate 2 and the material of the piston 5 is set to be less than 20%. Accordingly, it is possible to reduce noise.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a swash plate type motion conversion device for converting rotational motion into reciprocating motion, particularly to a compressor for a car cooler, and relates to a swash plate material of the device and a material in contact with the swash plate. This invention relates to a novel combination of sliding members (slippers) that slide on each other and transmit rotational motion of a swash plate to a piston.

[Background of the invention]

BACKGROUND ART Some types of refrigerator compressors, hydraulic equipment, and the like employ a swash plate type transmission mechanism as a means for converting motion from a rotational drive source into reciprocating motion of a screwdriver or the like.

FIG. 1 shows a model diagram of a swash plate compressor.

A piston 5 reciprocates left and right by a swash plate 2, a slipper 3, and a ball 4, which are obliquely attached to a rotating compressor shaft I-1.

At this time, the slipper is restrained by the ball on one side and slides on the swash plate at high speed on the other side. Therefore, the swash plate and slipper material are provided with reciprocating pistons,
Mechanical stiffness and fatigue strength for compressing gas bodies,
There are many requirements such as sliding wear resistance. Furthermore, uniformity of material quality and workability are also important factors to ensure reliability.

In a compressor for a refrigeration cycle, such as a conventional refrigerator or refrigerator, its operation is driven by a constant speed electric motor, and a mixture of refrigerant and lubricating oil is circulated through the compressor in a steady state. However, compressors for car coolers require extremely harsh conditions, which are not easy to meet. That is, in a swash plate compressor for a car cooler, its driving engine is a gasoline engine or a diesel engine, and the compressor is connected to the engine by a belt. Therefore, the rotation speed of the compressor was 60 Or, p, m when it was idling, but it decreased to 6,0 O after 10 to 20 seconds due to sudden acceleration after the first start.
Reach 98m. Furthermore, the vehicle started rapidly from a stopped state and reached 6.00 Or, 1.0 in 10 to 20 seconds. In some cases, the number may reach 4,000 to 5,000 m, and if the driver is inexperienced, the number may reach 4,000 to 5,000 within a few seconds from a stopped state due to so-called idling.
A situation may occur in which the compressor rotational speed is rapidly accelerated to Or, p, m. In this case, the slipper moves on the swash plate at a speed of 2.3 m/s when the engine is idling.
, 6 at maximum rotation + OOOr, p, m, 23
The sliding motion is performed at a speed of m/s, and the contact pressure that the slipper receives in order to further compress the refrigerant is 130 kg/aJ at idling and 40 kg/aJ at maximum rotation.
It becomes a#. In other words, the conditions required for the swash plate and slipper are a pressure of p (kg/aJ) and a speed of V (m
/S), it will be as follows.

At idle = 2,3x130 = 290 at maximum rotation
=23x40=920 Car cooler compressors, which are subject to rapid fluctuations in debt, use a mixture of Freon refrigerant and paraffinic or naphthenic refrigeration oil as a lubricant.
The lubricating properties of the lubricant are also not sufficient, and when instantaneous acceleration is performed from the compressor mechanism, the supply of lubricant to the sliding surfaces may be significantly reduced or interrupted. Therefore, when starting up, the lubricant may slide for several tens of seconds or, in the worst case, several minutes, with an incomplete supply of lubricant. In such a state, there is a drawback that welding and seizing occurs between the swash plate and the slipper, and between the slipper and the ball.

Noise is a major problem during compressor operation.

This is most strongly affected by the gap between the swash plate and the slipper.
Other factors that come into play include the finish roughness of the sliding surface and the damping capacity of the constituent materials. In particular, the problem caused by gaps is the amount of wear.

It was found that the difference in thermal expansion coefficients of the constituent materials has a large effect.

Conventionally, the swash plate was made of nickel chromium 1 (J), a structural alloy steel.
ISG4102), nickel chromium molybdenum steel (J
ISG4103) or chromium molybdenum steel (JI
SG4105) is used, and the sliding surface with the slipper is hardened by carburizing and quenching. Phosphor bronze for slippers, 2
0% silicon-aluminum alloy castings, copper-zinc alloys, etc. are used, and 20% silicon-aluminum alloy castings are generally used.

High carbon chromium steel (JIS G4805) is used for the ball. The piston is made of aluminum-silicon alloy casting (JISACaA).

If the swash plate is made of alloy steel, its thermal expansion coefficient is 10 to 12X.
10-4, the coefficient of thermal expansion is significantly smaller than that of the aluminum-silicon alloy casting of the piston, which is approximately 20X10-%.Therefore, the difference in the coefficient of thermal expansion between the two is extremely large, resulting in a temperature rise during operation. At the same time, there is a drawback that the gap in the activity plane becomes large and noise is generated. In addition, in a silicon-aluminum alloy casting having a slipper material of 20%, large initial silicon crystals are precipitated in the structure, resulting in poor machinability, resulting in a rough finished surface and increased noise. Also, phosphor bronze has low wear resistance, and gaps quickly become large, creating noise.

Another major problem is the problem of cracking of the swash plate or slipper due to the reciprocating motion of the piston.

[Purpose of the invention]

An object of the present invention is to provide a swash plate type motion conversion device that has low noise, excellent strength and wear resistance, and is difficult to break.

[Summary of the invention]

The present invention includes a rotating shaft, a swash plate that is fixed at an angle with respect to the axial direction of the shaft, a sliding member that slides in contact with both sides of the swash plate, and a rotational movement of the shaft through the sliding member. In a swash plate type motion conversion device, the sliding member contains 8 to 18% by weight of silicon, and is made of eutectic material by plastic working. The present invention relates to a swash plate type motion conversion device that is made of an aluminum-silicon alloy with an average silicon particle size of 5 μm or less, and in which the difference in thermal expansion coefficient between the swash plate material and the piston material is 20% or less.

The present invention is based on a conventional device (using aluminum as the piston material).
This was due to the discovery of the fact that the reason why silicon alloy castings are used and low-alloy steel is used as the swash plate material is that the noise is large is due to the large difference in coefficient of thermal expansion between the two. It has been confirmed through many experiments that when the difference in the thermal expansion coefficients exceeds 20%, the noise suddenly increases.

Furthermore, the invention is based on the discovery that slippers made of aluminum-silicon based alloy castings are very susceptible to cracking due to compression during the reciprocating movement of the piston. It has been found that the presence of casting defects significantly reduces fatigue strength and makes the product susceptible to cracking, and that eliminating casting defects through plastic working improves fatigue strength and makes it less likely to crack.

In the present invention, in particular, the sliding member has a coefficient of thermal expansion of approximately 20×101, and is made of 8% to 18% silicon and 1% copper by weight.
~4% magnesium, 0.1~0.6% magnesium, and the balance aluminum and impurities, and when subjected to plastic working, it is best to use an alloy in which the eutectic silicon grains have an average grain size of 5 μm or less. Are suitable. This material has high strength, and the PIAQ alloy has large grain boundary internal friction, so it has a large vibration damping ability and is highly effective in reducing noise. Therefore, it is highly effective as a sliding member.

Silicon needs to be at least 8% by weight in terms of wear resistance and workability, but if it exceeds 18% by weight, silicon crystals in the initial product will increase, reducing toughness and workability, so the upper limit is 18%.
It is heavy. When the amount of silicon reaches 20% by weight, primary silicon crystallizes into angular and coarse crystals, making it impossible to perform plastic processing and causing many casting defects. For this reason, when plastic working is performed, cracks occur in the primary silicon portion. When a piece with such cracks is cut, the primary silicon is ripped off and falls off, creating a hole where wear debris accumulates.

The accumulation of this abrasion powder damages the mating material, making the finished surface rough and producing noise.

From the above, when the amount of silicon reaches 20% by weight, it must be used in casting without plastic working, and since angular and coarse primary crystal silicon and long and thin eutectic silicon exist,
The machinability is poor, the finished surface becomes rough, and noise is generated. And! A decrease in strength due to structural defects is unavoidable, and cracks are likely to occur due to compression during reciprocating movement of the piston. It has been confirmed through many experiments that when the amount of silicon is 18% by weight or less, the primary silicon becomes fine and cracks do not occur even when plastic working is performed. Moreover, it was confirmed that the plastic working improved the strength and made it less likely to crack under compression caused by the reciprocating motion of the piston. In the present invention, it is preferable to contain copper and magnesium in order to ensure the mechanical properties of the member. In this case, the content of copper is 1% by weight or more in terms of strength and wear resistance, and 4% by weight or less in order to prevent cracking during casting of the alloy material. The content of magnesium is 0.1% by weight or more in terms of increasing strength, and 0.6% by weight or less in terms of toughness and workability. By rapidly solidifying a molten aluminum-silicon alloy having such a composition range at a cooling rate of 5°C/second or more, the initial silicon grains are refined to an average grain size of 5 μm or less, and the silicon grains are further refined into plastic particles. By processing, the silicon grain size of the eutectic structure can be reduced to an average grain size of 5 μm or less. Then, if necessary, heat treatment such as hardening, annealing, and tempering is performed, and the product is processed.

Internal friction can be further increased by making the crystal grains finer by setting the silicon grain size to an average grain size of 5 μm or less. By making the crystal grains finer in this way, wear resistance and workability are also improved.

Swashplates need strength and wear resistance. It can be used even if it is machined from a material that has been heat-treated after finely dispersing silicon grains using the cooling rate and processing conditions described above, but in order to make it stronger, the surface of the swash plate member must be On the other hand, it is preferable to perform cold or hot forming to arrange the silicon grains in the processing direction. on the other hand,
In the case of slippers, sufficient strength can be obtained by manufacturing them from the above-mentioned materials by cutting.

Further, by coating the surfaces of the swash plate and slipper with a wear-resistant alloy layer, the life of the swash plate and slipper can be further improved. Coating methods include thermal spraying of metals, ceramics, plastics, etc.

Plating method, ionization plating method, sputtering.

Welding, pressure welding, two-way bonding methods, etc. can be used. The thickness of the coating varies slightly depending on the coating material, but is approximately 5 μm.
The above is necessary.

(Embodiments of the invention) Example 1 As a swash plate material and a slipper material, 11.7% silicon (Si), 2.3% copper (Cu), 0.3% magnesium (Mg), and 0.21% iron (by weight) were used. F e) and the balance aluminum (AQ) are melted into a synthetic aluminum alloy, and a diameter of 100 mm and a length of 2,000 m is made by continuous casting.
An ingot was produced. Note that iron is an impurity. 40 ingots
Preheated to 0°C, extrusion was carried out on 18 nn and 45 m diameter blanks.

The material with a diameter of 45 mm was further preheated to 400° C., warm forged and formed, and then subjected to T and J treatments. Thereafter, the swash plate shown in FIG. 1 was manufactured by mechanical finishing. The material extruded to a diameter of 18 mm was subjected to T and S treatments, and slippers were manufactured by machining. As a result of observing these products under a microscope, it was found that the eutectic silicon particles were uniformly dispersed with an average particle size of 5 μm or less. Its tensile strength was approximately 45 kg/+anFj.

The table below shows a strength comparison between the slipper of the present invention and a conventional 20% by weight silicon-aluminum alloy cast slipper.

Regarding the slipper, its fracture strength in combination with a ball was compared with that of a conventional 20% silicon-aluminum alloy cast slipper. Most conventional products break at 4 to 6 tons,
Approximately 1% of them were seen to be destroyed at less than 3 tons. All of the slippers of the present invention could withstand more than 20 tons, and were extremely excellent in both strength and stability.

FIG. 2 shows the crushing strength and its distribution for the slipper of the present invention and the conventional aluminum-silicon alloy cast slipper. As a result, the slippers of the present invention have a lower limit of about 1
It is clear that it is a ton expensive.

Next, a severe test was conducted in a car cooler using the slippers of the present invention and the conventional slippers, and using JISAC8A alloy for the piston.

The test was started - surface pressure 40kg/alt, rotation speed 600゜r.
, 9.111.9 hours 5 h - surface pressure 100 k gla
i, number of rotations: 400 Or, p, m, time: 10 h - repeating the cycle of stop and start, the test was conducted for 2000 hours, and the noise before and after the start of the test was determined atq. Noise measurements were taken at a location 30C11 away from the car cooler itself.

As a result, a swash plate made of nickel-chromium steel (
The difference in thermal expansion coefficient (40% or more) with the piston was 60 decibels, whereas the one of the present invention was 50 decibels, which was significantly superior. Furthermore, the noise level after the test was approximately 10 horns higher with the present invention than before the test, whereas it was approximately 25 horns higher with the conventional material.

After the test, the compressor was disassembled and the wear conditions of the slipper and swash plate were compared.

The slipper using a nickel-chromium alloy steel swash plate had many scratches on the sliding surface of the slipper, some of which were as deep as LOOμm.

On the other hand, in the present invention, there were few flaws, and the depth of the flaws was 50 μm or less. Comparing the amount of wear between slippers, the conventional product is 1
It was 0 to 15 μm, but in one product of the present invention, it was 5 to 8 μm,
It was extremely good.

Example 2 17% by weight 5i-1,7ffli%C as slipper material
Using u-0, 20% by weight M g -A Q alloy, a material was manufactured in the same process as in Example 1, and slippers were manufactured by cutting.

The swash plate is made of an alloy with the same composition as in Example 1, and has an alloy of 200 to 30
It was manufactured by cutting after forging at 0°C.

Moreover, JISAC8A was used for the piston. Furthermore, in this example, both sides of the swash plate are grid blasted, and 3% by weight carbon steel is applied to the surface by plasma spraying to approximately 0.2%
A thermally sprayed version with a thickness of 5 vans was also produced. Similarly, the sliding surface of the slipper with the swash plate is made of stellite alloy, tungsten carbide (WC) and 12% by weight cobalt (Co).
), 3 wt% carbon steel-molybdenum (Mo) was sprayed to a thickness of 0.1 mm by plasma spraying, and polished to a thickness of approximately 30 μm.
A thermal sprayed layer with a thickness of .

The following combinations were subjected to a severe test using a car cooler for 2,000 hours in the same manner as in Example 1.
The noise and wear conditions before and after the test were examined.

(1) Swash plate made of carburized and quenched chromium molybdenum steel (JIS G4105), 20 wt% 5i-AQ alloy casting sleeve (2) Swash plate made of AQ-5i alloy of Example 1, WC-12 wt% Co sprayed AQ-3i alloy slipper of Example 2 - (3) AQ-5i alloy swash plate of Example 1, AQ-S i alloy slipper of Example 2 coated with Stellite alloy (4) To of Example 1 〇-3i alloy swash plate, AQ-3i alloy slipper of Example 2 with 3 wt% carbon steel-Mo sprayed (5) Swash plate with 3 wt% carbon steel sprayed on Al11-5i alloy of Example 1, As a result of tests on combinations of AQ-8i alloy slippers and above in Example 2, the noise of the car cooler according to the present invention in (2) to (5) was very low at 50 decibels, and the noise of the car cooler according to the present invention in (2) to (5) was extremely low, and it was found that the noise of the car cooler according to the present invention in (2) to (5) was very low, and that The level was 60 decibels.

It was also observed that the wear conditions of the materials according to the present invention were approximately 0% less than those using conventional materials.

〔Effect of the invention〕

According to the present invention, excellent effects can be obtained in that the noise of a swash plate type motion conversion device, particularly a compressor for a car cooler, can be significantly reduced, and cracking of the slipper due to the reciprocating movement of the piston can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram of the swash plate type motion conversion device, and FIG. 2 is a characteristic diagram showing the crushing strength and strength distribution of the slipper. 1. Rotating shirt 1-52... Swash plate, 3... Slippers, 4... Ball, 5... Piston.

Claims (2)

[Claims] 1. A rotating shaft, a swash plate fixed at an angle with respect to the shaft axis direction, a sliding member sliding in contact with both side surfaces of the swash plate, and rotation of the shaft via the sliding member. In a swash plate type motion conversion device, the sliding member contains 8 to 18% by weight of silicon and is plastically worked. made of an aluminum-silicon alloy with a eutectic silicon grain size of 5 μm or less, and the difference in thermal expansion coefficient between the swash plate material and the piston material is 20% or less. A swash plate type motion conversion device featuring: 2. In claim 1, the sliding member is made of 8 to 18% silicon, 1 to 4% copper, and 0 magnesium by weight.
．． It is characterized by being made of an aluminum-silicon alloy having a chemical composition of 1% to 0.6%, the balance being aluminum and impurities, and having an average grain size of eutectic silicon grains of 5 μm or less through plastic working. Swash plate type motion conversion device.