JPS6053196B2 - Swash plate type compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compressor, and in particular to a swash plate type compressor that has recently become widely used for car coolers, and its main purpose is to provide higher performance than conventional compressors of this type. Our goal is to provide compressors with a long service life.

As shown in FIG. 1, a swash plate compressor generally includes a swash plate 5 that is attached to a shaft 4 disposed within a cylinder block 1 and rotates with the shaft 4;
The rotary movement of the shaft 4 is controlled by the piston 3 moored across the swash plate 5 by the shoe 6 which slides while contacting the swash plate 5 and the ball 7 which keeps the movement of the shoe 6 in a free state.
is converted into a reciprocating motion.

In this basic structure, the medium to be compressed, such as refrigerant gas, which circulates in the refrigeration circuit and returns to the compressor, is compressed to high pressure in the cylinder bore 2 by the piston 3 and sent to the compressor (not shown). There, after being cooled and liquefied, it is sent to an evaporator to evaporate and remove latent heat of vaporization from the surroundings to cool the indoor air, while the removed heat is released into the air (atmosphere) while passing through the condenser. They are made to do it repeatedly. However, when such a swash plate compressor is used for a car cooler, the operating conditions are extremely severe.

In other words, the drive source is an internal combustion engine such as gasoline or diesel, and the structure is such that the rotation speed is almost the same as that of the internal combustion engine due to the purpose of making the compressor smaller and lighter, and the compressor capacity. . Therefore,
The rotation speed of the swash plate compressor is subject to conditions ranging from approximately 500 rpm, which is the rotation speed of the internal combustion engine when it is idling, to approximately 6000 rpm, such as when driving at high speed or during rapid acceleration. Additionally, although this problem is not limited to swash plate compressors, as vehicles become lighter in recent years, the compressor itself is required to be smaller and lighter, and the oil pump inside the compressor is removed. As the amount of lubricating oil is reduced in order to improve performance, friction and wear are becoming more likely to occur on the sliding parts within the compressor.

Furthermore, the increase in temperature in the engine room due to the installation of various devices in the engine room in recent years, such as exhaust gas control devices and devices to reduce fuel consumption, has an adverse effect on the lubricating oil in the compressor. It's getting harder to get rid of.

In a swash plate compressor used under these conditions, the part most adversely affected by the above conditions is the sliding portion between the swash plate 5 and shoe 6 shown in FIG. The sliding speed is approximately 2 to 3 mIsec when the engine is idling, and 20 to 25TrL1Se at approximately 6000 rpm at maximum rotation.
This is because they are slid at an extremely high speed of about 7 to 15 ml sec even during normal running. In addition to such high-speed sliding motion, a load acts on the shoe to compress the medium to be compressed, such as refrigerant, and the magnitude of the load is 60 to 130k9/Clt, and the sliding speed and pressure It is rare that both are the maximum combination, but the PV value (pressure Pk9/Cltl speed ■T
rl, ISeC) may often exceed 2000. Moreover, this is repeated in relation to the rotational speed. The load that the shoe receives from this repetition becomes an impact load, especially at high rotation speeds, and the extremely harsh conditions of receiving such impact load and sliding at high speed are extremely harsh on the sliding part between the swash plate and the shoe. will occur.
Also, when looking at the sliding situation between the swash plate and shoes from the lubrication perspective, with the removal of the oil pump as mentioned above, the lubricating oil supplied to the sliding parts is supplied in a slightly gaseous state by mixing with refrigerant gas. It will only be done.

This is because a swash plate compressor with an oil pump removed is generally lubricated by refrigerant gas containing oil being skillfully circulated around each sliding part within the compressor, but in this case This is because the amount of oil and the cooling capacity are inversely proportional to each other, so reducing the amount of oil is an effective means of increasing the cooling capacity of the swash plate compressor. From another perspective, it is the lubrication conditions that have the most influence on the life of the sliding parts of the swash plate and the shoes, and in particular, the amount of lubricating oil has the most influence.
Therefore, among these conflicting relationships, what is particularly considered when designing a swash plate type compressor is the materials of the swash plate and shoes that can meet the harshest sliding conditions. Furthermore, since the sliding motion between the swash plate and the shoes is a thrust sliding motion in which it is difficult to obtain a sufficient lubrication effect even if sufficient oil is supplied, the sliding surfaces must always be under boundary lubrication. , or there is solid contact there.As a phenomenon that occurs because the swash plate compressor for a car cooler performs unsteady rotational movement that is inevitable in its use, there is a phenomenon in which the sliding surface between the swash plate and the shoe In this case, lubricating oil is not supplied for several tens of seconds or even several minutes after startup, and therefore, during this period, the swash plate and shoes are completely unlubricated and operated in solid contact. becomes. This situation occurs when refrigerant leaks from the pipes and the amount of refrigerant contained in the refrigeration cycle decreases,
This problem also occurs when the amount of refrigerant returned to the compressor is reduced by operating the evaporation pressure regulating device attached to the evaporator. Therefore,
Among the various troubles that have arisen in swash plate compressors to date, the most common is the seizure described above that occurs without lubrication from the time of startup, and the wear that occurs without lubrication can become a fatal defect. This caused burn-in.

Traditionally, swash plates have been made of structural materials that have mechanical rigidity, fatigue strength, and wear resistance, as materials that can withstand the above-mentioned lubrication conditions, as well as materials that can withstand the high surface pressure and impact loads mentioned above. Alloy steels such as nickel-chromium steel, nickel-molybdenum steel, chromium-molybdenum steel, and spheroidal graphite cast iron were used, and the surface layer was hardened.

In addition, materials such as high carbon chromium steel were used mainly for the holes in order to withstand high loads. As the shoe material, Algyl alloy, phosphor bronze, copper-lead-tin alloy, brass, high-strength brass alloy, bronze alloy, aluminum bronze alloy, Babbitt metal, oil-impregnated bearing alloy, etc. have been considered. However, none of the materials known to date have been able to fully satisfy the aforementioned extremely harsh operating conditions unique to swash plate compressors for car coolers. In regards to
Previously, the applicants found that a bimetallic material made by sintering a copper-lead-tin alloy powder onto a steel plate was the only material that could extend the lifespan, and filed the patent application as Japanese Patent Application No. 109856-1983. , Even if the material related to this application is made smaller,
This is not necessarily sufficient for swash plate type compressors, which require high performance, and under more severe conditions, the shoes often seize. There is a desire to develop materials with a long lifespan that have properties that are even better than those of conventional materials, such as excellent properties.

In view of the above-mentioned circumstances, the inventors of the present invention have conducted various research and development and have found that the sliding speed is 2 to 25 m1sec.
It can withstand repeated operations and repeated shock loads of 130 to 140 kg/cl of surface pressure, and the supply of lubricating oil is extremely small, in the form of a mixed gas with refrigerant, and there is no lubrication for several seconds to several minutes after startup. The present invention was completed by discovering an excellent alloy material that can sufficiently withstand sliding under pressure and applying it to shoe materials for swash plate compressors, particularly car coolers. That is, the present invention is made of a copper alloy that has been strengthened to the extent that the thermal conductivity is not significantly reduced, has little decrease in hardness especially at high temperatures, and has good sliding properties.

The purpose of the present invention is to provide a shoe that solves all of the conventional problems described above.
Mainly U, plus 1 to 8% (by weight, the same applies hereinafter)
Manganese Mn. ．． O. 1 to 4% silicon Si, and further 0.5 to 15% lead Pb or 0.5 to 15%
% of Pb and less than 5% (not including zero) of tin and Sn. Mn and Sj used in the present invention are additive elements that are mainly dissolved in Cu to improve mechanical strength, but when they are added to Cu at the same time, Mn. Precipitates are formed by compounds with 5Si, and based on the solid solution and precipitation effects of these elements, Cu
This effectively strengthens the structure and improves wear resistance.

In particular, the amounts of each of the solid solution additive elements N4n and Si added to Cu according to the present invention are as follows:
It will be determined taking into account the following: That is, first of all, Si is used in the range of 0.1 to 4%, preferably 0.3 to 2.0%, and if it is less than 0.1%, the amount of Si in solid solution is insufficient as a solid solution strengthening element for Marix, and it is not sufficient. Moreover, if it is added in an amount exceeding 4%, the intermetallic compound or the precipitated alloy will become brittle. Moreover, Mn is 1 to 8%, preferably 1
．． It is necessary to add at a rate of 5 to 5%, especially 4 to 5%.
It's also good. This is because although Mn alone can mechanically improve the structure through solid solution, when Mn is added together with S1, an ideal eutectic silicide is obtained and excellent wear resistance is obtained. However, if the amount of Mn added is less than 1%, it becomes a hypoeutectic silicide, and sufficient wear resistance cannot be obtained.On the other hand, if it exceeds 8%, the hardness of the matrix becomes too high and wears the mating material. This is because lead (Pb), which is added to Cu along with Mn and Si, is a low-melting point material that does not dissolve in the Cu base material.
(melting point: 400° C. or lower), and by adding Pb or P metal mainly composed of Pb, which is a low melting point material, the sliding properties of the shoe, especially the conformability and slipperiness, can be significantly improved. It is.

Due to this effect, various troubles caused by the shoes sliding under no lubrication during startup and under boundary lubrication during operation, which are unique to high-performance swash plate compressors, can be more effectively eliminated. You will get it. In addition, in order to fully exhibit the effect of adding Pb, it is necessary to
An addition amount of 15% is required, and if the addition amount is less than 0.5%, the desired sufficient compatibility cannot be obtained;
If it exceeds %, it is difficult to uniformly disperse it in the alloy, necessitating the use of special manufacturing methods, and further reducing the strength of the matrix, which is not preferable. Furthermore, in addition to these additive elements, Cu
Sn added to Cu has a different effect from that of Pb, and not only strengthens the matrix by being dissolved in Cu, but also lowers the coefficient of friction in terms of sliding properties.
Moreover, this friction coefficient is a low friction coefficient that is stable even at high temperatures, and as a result, it exhibits an excellent effect on seizure resistance especially under high temperature conditions.

However, since such added Sn dissolves in Cu as described above, it tends to reduce the thermal conductivity of the alloy, and therefore the range of its addition is limited. In this sense, 5% is adopted as the upper limit of its addition, therefore Sn is 5%
The amount to be added is determined as appropriate within a range of less than 1 (of course not including zero), and the preferred amount to be added is 1.
~3% is most desirable. Therefore, according to the present invention, Cu is used as a base material, and Mn, Si and low melting point materials (
An alloy to which Sn is added together with Pb) has an alloy composition that has excellent characteristics as a shoe material.

However, the most important issue with swash plate type compressor shoes for car coolers when the amount of lubricating oil is small is the shoe's thermal conductivity, and what has the greatest effect on that thermal conductivity is the additive elements, and the friction The magnitude of the coefficient is the direct cause of heat generation. Therefore, how to strengthen the matrix and improve conformability with as few additive elements as possible is the key to whether or not it can be better adapted as a swash plate type compressor shoe for high-performance car coolers. Because there is. Since a certain amount of lubricating oil is supplied during so-called normal operation, although it is relatively small, it is important to have good thermal conductivity and effectively dissipate heat, especially for the shoe material, rather than focusing on conformability. Also, minimizing the decrease in hardness under high temperatures and minimizing changes in structure affect the smoothness of the shoe. In this sense, the combined use of Mn and Si or the addition of Sn together with them has an important effect, but on the other hand, Pb, which is a low melting point material added mainly for the purpose of improving conformability, has an important effect. does not have a very noticeable effect during normal operation. However, on the other hand, when the engine is operated under conditions that are closer to no lubrication than at the time of startup, the conformability effect of the low melting point material Pb is greatly exhibited. In addition, even if the swash plate compressor for high-performance car coolers is designed to eliminate these problems in a short time by improving the no-lubrication situation at startup, it is impossible to eliminate them completely. In addition, reductions in the amount of oil and refrigerant gas occasionally occur during normal operation, and shoe materials that can cope with these various conditions are required to have various performances.

Therefore, it is necessary to fully consider the selection and amount of additive elements according to the present invention, the resulting degree of reinforcement, and thermal conductivity.
The most appropriate combination is Cu, Mn, Si, and P.
It is desirable to add both B and Sn.

In particular, in addition to strengthening the entire matrix and improving wear resistance due to solid solution, too much solid solution elements can cause harm due to intermetallic compounds, resulting in uneven structure and decreased thermal conductivity.
In order to eliminate the brittleness caused by over-hardening of the matrix, it is possible to strengthen it without causing much harm as described above.
If an additional element capable of forming precipitates is used in combination according to the present invention, it is possible to expect resistance to seizure and wear resistance due to the precipitates, and it is possible to achieve this without significantly reducing thermal conductivity.

Note that when selecting a sliding material, the selection of a mating material is also important, and when the conditions are particularly severe, the mating material is also more limited. Even under such circumstances, conventional sliding materials have a mating material of Cr.
Steel and Mn steel are relatively good, but spheroidal graphite cast iron has poor sliding properties and is unsuitable as a mating material. However, it has been confirmed that the shoe material made of the Cu alloy according to the present invention can withstand even when the mating material is spheroidal graphite cast iron. Additionally, according to the inventors' study, the thermal conductivity required for a shoe material that can be used in a swash plate compressor for a high-performance car cooler is 0.2ca11c1t.
・It is desirable that the temperature is Sec・℃ or more, and furthermore, 0.4c.
a11c71!・It has become clear that it is more preferable to have a hardness of Sec・℃ or higher, and that it is desirable to have a Vickers hardness (Hv) of 80 or higher at a high temperature of 300℃. However, all of the Cu alloys according to the present invention have such desirable thermal conductivity and hardness, and thus exhibit excellent effects. Next, preferable alloy structures according to the present invention include those in which Mn, Si, and Pb are added to Cu.

When Mn, Si and Pb are added, the matrix is strengthened due to partial solid solution of Mn and Sl, wear resistance is improved due to the precipitation of a compound of Mn and Si, and conformability and boundary lubrication are improved due to the addition of Pb. Therefore, a material with good smoothness can be obtained under
nl. 5-5%, SiO. By selecting 3 to 2% of Pb and 5 to 10% of Pb, properties are imparted such that the thermal conductivity is not reduced and the hardness decreases little at high temperatures, thereby exhibiting excellent effects. In addition, when Sn is further added to these element combinations (that is, Mn, S
i, Pb and Sn), Sn
Since it is extremely easy to form a solid solution in Cu, this causes the S
In addition to the effects of the n-free Cu alloy, it is possible to obtain a shoe material that has sufficient mechanical strength, is more stable even at high temperatures, and has a lower coefficient of friction.

In this case, the preferred addition ratio is Mnl. 5-5%, Si
O. 3 to 2%, Pb to 5 to 10%, and Snl to 3%.
Incidentally, the addition of Sn is also effective in improving castability. As a result, the following effects can be recognized in the Cu alloy according to the present invention.

In other words, since the amount of added elements is significantly smaller than conventional shoe materials, it has good thermal conductivity and can easily dissipate the frictional heat generated even in long periods without lubrication, and the shoe material remains stable even at high temperatures. There is no softening of the material, which makes it less likely to cause seizure. In addition, in the case of the present invention, there are fewer additive elements for strengthening than in the past, so it seems that sufficient strengthening has not been achieved compared to the conventional materials, but in the case of the conventional materials, Copper in this invention Although it was somewhat superior to alloys at room temperature, the overall strength was lower.On the other hand, the present invention does not have any additional reinforcing elements, but also has few compatibility-improving materials (elements). As a result, there is not much difference in strength compared to conventional materials. However, especially at high temperatures, the copper alloy of the present invention exhibits better values than conventional alloys. Furthermore, in the present invention, there is a small amount of conformability improving materials, and in addition, by adding solid solution elements such as Mn, Si, and Sn, which have little decrease in hardness even at high temperatures,
Even when the shoe becomes high temperature due to frictional heat, etc., the strength and hardness of the matrix do not decrease and are in an extremely stable state. Therefore, because of this extremely stable matrix state, it is uniformly dispersed. The compatibility improvement effect of Pb and the like is also more effectively exhibited. In addition, the Cu alloy of the present invention has other additive elements such as nickel, Ni, iron, Fe, tellurium, Tel, phosphorus, P, antimony, Sb.
It is possible to add a small proportion of arsenic, As, etc., which mainly has the effect of improving strength or making the matrix finer, but each has advantages and disadvantages in the effect of addition.
It has been confirmed that the performance is slightly lower than that of Mn, Si, Pb, and Sn.

However, it has been confirmed that it can withstand use under certain conditions. Below, in order to further facilitate understanding of the present invention,
A specific example of the present invention will be shown.

First, samples 1 to 6 were prepared using the casting method using the composition ratios shown in Table 1.
I got it.

As a casting method, the alloying elements Mn and S are cast at approximately 1250°C.
i, Sn. ．． A method of adding Pb in this order was adopted, and the resulting material was heat treated at about 700° C. for 2 hours to prevent segregation, to obtain a Cu alloy material. In order to conduct actual machine tests using these obtained materials, each material was made with a diameter of 18Wr! A shoe was obtained by processing to n1 thickness 4.5T1Un.

Further, this shoe has a spherical concave surface with a depth of about 3 in order so that a part of a ball having a diameter of about 14W11 is inscribed in the center. As comparison materials, Samples 11 to 18 having the alloy compositions shown in Table 2 were prepared by the same method as above, and compared with the shoe made of the Cu alloy according to the present invention. Also, sample 1
The hardness at the final processing at normal temperature of No. 6 to 6 all had a hardness of HvlOO or higher.

Furthermore, the thermal conductivity of each of the obtained samples was measured and shown in Table 3. As is clear from the table, all the samples made of the Cu alloy of the present invention had excellent thermal conductivity. There is. Experiment 1 An experiment was conducted using each of the samples shown in Tables 1 and 2 to measure the friction coefficient and the temperature at which the friction was generated.

The measurement method was to rotate a disk, press a shoe against it, and measure the friction coefficient and heat generation temperature of the shoe while gradually increasing the pressing load.

Conditions (1) Slip speed constant 13TrL/SeC (2
) Load 20k9/d from 40k9/Cll
gradual increase
Each load stage has 3 powders (3) Lubricating oil Low viscosity oil SSU7O'' (4) Lubrication method Felt application approx. 0.8 cc/min (5) Test piece Disc straightness 1 μm or less, roughness (large) 70.4 ~ 0
．． 6-S Shuuni straightness 1μm
Bottom, roughness (maximum)
0.4 to 0.6-S The results obtained are shown in FIGS. 2 and 3.

Note that Figures 2 and 3 are part of the experimental results. Similar results were obtained with the other μ materials 1, 3, 4, and 6, although the performance was slightly lower than that of 2 and 5. As is clear from FIG. 2, the sample based on the present invention has a lower coefficient of friction in all regions than the comparative material, and is stable even when the load is increased. Further, when looking at the heat generation temperature of the shoe from FIG. 3, it is found that the sample according to the present invention is lower in all regions than the comparative sample.

Furthermore, when these results are compared with the thermal conductivity of each sample in Table 3, all the samples of the present invention having a thermal conductivity above a certain level are good. From these facts, if the load is increased, the frictional resistance will naturally increase and heat generation will occur.
The structure of the material changes due to this heat generation, and the comparison sample with poor thermal conductivity tends to seize due to an increase in the coefficient of friction, but the sample of the present invention has a tendency to seize due to the increase in the coefficient of friction. Because of its excellent heat dissipation properties, the temperature of the entire shoe or the temperature near the sliding surface does not rise too much, so there is no phenomenon such as changes in structure or increase in the coefficient of friction, and it is stable in all areas. There is.

What is particularly noteworthy in this case is that even though the oil lubrication was not sufficient, the samples of the present invention performed well, which is of great significance. Experiment 2 Next, an actual machine test was conducted under the most severe conditions for supplying lubricating oil, and the results obtained are shown in Table 4.

The test conditions are as follows. (1) Compressor Swash plate compressor (total displacement 150cc) (2) Rotation speed 4000 rpm (3) Discharge side gas pressure Pd = 4 ~ 5k9/Clt (4) Suction side gas pressure Ps = approx. -50TS1LHg (5) Operating time
20Hrs (6) Lubricating oil Refrigerator oil 15
0cc (7) Mating material Spheroidal graphite cast iron (8) Ga
As is clear from Table 4, all of the samples according to the present invention were in good condition with no seizure occurring at all.

In particular, since this experiment was conducted under the most severe lubrication conditions that occur under normal operating conditions, the fact that it was satisfied even under such conditions is proof of the superiority of the Cu alloy sample according to the present invention. It is. Experiment 3 Next, as a load life test, an actual machine test was conducted under conditions that are particularly likely to cause poor lubrication, and the results are shown in Table 5.

The test conditions are as follows. (1) Compressor Swash plate compressor (
Total displacement 150cc) (2) Rotation speed 5500r'Pm
(3) Discharge side gas pressure Pd=20k9/Clt (4) Suction side gas pressure Ps=3k9/Clt (5) Operating time
400Hrs (6) Lubricating oil and quantity Refrigerator oil,
150cc (7) Continuous operation 2 times, 5 seconds pause (8) Partner material Spheroidal graphite cast iron (9) Gas amount 1 kg 7 As is clear from Table 5, samples 1 to 6 according to the present invention are all compared. Compared to Samples 11 to 18, there was no seizure phenomenon and the amount of wear was small, and it was found that the samples could be used satisfactorily.

Since this experiment was conducted in a situation where almost no lubricating oil was present, the fact that it performed well indicates that seizure is unlikely.

As detailed above, the present invention can be applied to a compressor, especially a swash plate type compressor for a car cooler, even if there is very little lubricating oil and the sliding parts of the swash plate and shoes are not sufficiently supplied with oil. Even if it occurs,
Furthermore, even if the mating material is spheroidal graphite cast iron, which has poor sliding properties, the use of a shoe material made of a specific Cu alloy that is less likely to wear out and has excellent thermal conductivity allows it to be used for an extremely long time. This invention has great significance in that it has been able to provide a swash plate type compressor that can withstand high temperatures and has a long life, and has contributed greatly to improving the performance of compressors for car coolers in particular.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view for explaining a swash plate compressor, and FIGS. 2 and 3 are graphs showing the friction coefficient and heat generation temperature results obtained in Experiment 1, respectively. 1... Cylinder block, 2... Cylinder bore, 3
... Zestone, 4... Shaft, 5... Swash plate, 6.
・UyuIl7l●Bokol.

Claims (1)

[Scope of Claims] 1. A swash plate that is rotated by a rotating shaft within a cylinder block, and a piston that is moored to the swash plate via a shoe, and the piston moves into the cylinder bore according to the rotation of the swash plate. In the swash plate compressor, the shoe is mainly made of copper, which contains 1 to 8% manganese and 0.1 to 4% silicon, and further contains 0.5 to 15% of silicon. A swash plate compressor characterized by being made of a copper alloy containing % lead. 2 A swash plate that is rotated by a rotating shaft within a cylinder block, and a piston that is moored to the swash plate via a shoe, so that the piston reciprocates within the cylinder bore in response to the rotation of the swash plate. In the conventional swash plate compressor, the shoe is mainly made of copper, and
Characterized by a copper alloy containing ~8% manganese and 0.1-4% silicon, further containing 0.5-15% lead and less than 5% (not including zero) tin. Swash plate compressor.