JPH1061575A - Blade for compressor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily get a blade in/from a spiral groove, and to improve the sliding characteristic, abrasion resistance and sealing property by forming a space inside of a spiral blade made of fluororesin, which forms a compressing element of a compressor, along the spiral direction thereof, and communicating a part of this space with a compression chamber. SOLUTION: A compressing element of a helical blade compressor is formed of a spiral blade 12, which is made of PTFE resin and which is arranged along the inner peripheral surface of a cylindrical cylinder 11, and a piston 14 having a spiral groove 13, in which the blade is to be fitted, and the pitch of the spiral groove 13 is formed so as to be gradually reduced from a coolant inlet side toward the coolant outlet side. In this case, the blade 12 is formed into the hollow structure having a square cross section having a space 16 inside thereof, and a part of the space 16 is opened to a high-pressure Pd side, and while formed into the closed-shape at a low-pressure Ps side. Flexibility is thereby increased by providing the space 16 in the blade 12, and the blade can be easily get in/from the spiral groove 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical blade constituting a compression element of a helical blade compressor applied as, for example, a compressor for compressing a refrigerant gas in a refrigeration cycle apparatus, and a method of manufacturing the same.

[0002]

2. Description of the Related Art With reference to FIGS. 17 to 22, a prior art of this type of compressor blade and a method of manufacturing the same will be described.

FIG. 17 is a sectional view showing a compression element in a helical blade compressor. The compression element is provided in a casing as a single type or a twin type, and a cylindrical cylinder 1, a spiral blade 2 arranged along the inner peripheral surface of the cylinder 1, and the blade 2 are fitted. A piston 4 having a spiral groove 3, and the blade 2 is configured to rotate by rotation or revolution. The pitch of the spiral groove 3 is gradually reduced from the refrigerant inlet side to the refrigerant outlet side, and the refrigerant gas flows from the low pressure (Ps) side to the high pressure (Pd) in the compression chamber 5 surrounded by the cylinder 1, the blade 2 and the piston 4. ) Compressed while flowing towards the side.

FIG. 18A shows a blade 2 shown in FIG.
FIG. 2B is a right side view of FIG. FIG. 19 is a perspective view of the blade 2 partially shown in section, and FIG. 20 is an enlarged sectional view showing the contact state between the blade 3 and the edge 3 a of the spiral groove 3. As shown in these figures, the blade 2 is formed in a helical shape with a constant pitch, and has a solid rectangular cross section. Conventionally, as a constituent material of the blade 2, a fluorine-based resin having excellent characteristics such as flexibility, sealability, sliding characteristics, and environmental friendliness (temperature, oil, refrigerant), for example, a tetrafluoroethylene resin (PTFE resin), perfluoroalkoxy resin (PFA resin), and the like are often used. For the purpose of improving the wear resistance, a composite material containing an inorganic fiber filler such as glass fiber or carbon fiber, a solid lubricant, an organic filler, or the like may be used.

[0005] As a processing method of the blade 2, when a material such as ethylene tetrafluoride resin (PTFE resin) that cannot be melt-formed is used, cutting is applied, for example, cutting from a round bar material. Created by In this case, since it is difficult to work at an irregular pitch corresponding to the shape of the spiral groove 3 shown in FIG. 1, it is formed into a spiral with a constant pitch in the manufacturing stage as shown in FIG.

On the other hand, perfluoroalkoxy resin (PF)
In the case of using a melt-moldable fluororesin represented by (A resin), a spiral blade having a constant pitch or an irregular pitch is formed by a normal injection molding method.

Since the fluororesin greatly changes its dimensions due to thermal expansion, swelling due to refrigerant gas, etc., as shown in FIG. 20, the edge 3a of the spiral groove 3 of the piston 4 and the blade fitted thereto It is necessary to take a certain amount of clearance c between them.

[0008]

SUMMARY OF THE INVENTION The aforementioned blade 2
From the viewpoint of assemblability, strength, and the like, it is preferable to manufacture by injection molding capable of processing an irregular pitch shape corresponding to the spiral shape shown in FIG. However, when the solid-shaped blade 2 is manufactured by general injection molding, as shown in FIG.
Is cooled and solidified, the interior 7 is in a molten state, and the interior solidifies with a delay. Therefore, as shown in FIG.
Shrinkage at the time of internal solidification causes a sinker a, and there are problems such as a dimensional defect, a density distribution due to a pressure gradient, and a dimensional change with time due to a residual stress. In injection molding, it is desirable to increase the filling speed as a molding condition.However, since fluorocarbon resin has high viscoelastic properties due to its high melting clay, the shear stress at the interface between the mold surface and the resin is reduced in ordinary injection molding. In addition, there have been problems such as peeling of the surface layer (skin layer) and the inside (core layer) and the sliding characteristics being significantly impaired due to a phenomenon (delamination) such as surface roughness.

In the conventional solid-shaped blade 2, since the elastic deformation is small, the contact area at the edge 3a of the helical groove 3 is reduced to generate concentrated stress and increase the surface pressure. And the wear was easy to increase. on the other hand,
When a filler is combined to improve the frictional characteristics, the rigidity of the material is increased, and the property of entering and exiting the spiral groove 3 may be poor. The fluororesin composite material containing the filler decreases the fluidity of the resin in injection molding, and the decrease in the fluidity deteriorates the moldability, thereby causing dimensional defects.

Further, when the clearance c is set large considering the thermal expansion of the blade 2 and the amount of swelling due to the refrigerant, the amount of swelling is small in the initial stage of use and the temperature is low when the compressor is started. As a result, there is a problem that the sealing performance is deteriorated and a predetermined compressor performance cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide high elasticity, good access to a spiral groove, high sliding characteristics, abrasion resistance and sealing properties, and compressor performance. Another object of the present invention is to provide a compressor blade capable of improving reliability.

Another object of the present invention is to make it possible to easily form the blade, to reduce the residual stress, and to obtain a blade having high dimensional accuracy without sinking. In addition, it is an object of the present invention to provide a method for manufacturing a compressor blade, which can improve the productivity by improving the material yield and shortening the molding cycle.

[0013]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a helical fluorine resin blade constituting a compression element of a compressor, wherein a helical fluorine resin blade is provided along the helical direction. Provided is a compressor blade having a space, and having a configuration in which a part of the space communicates with a compression chamber.

According to a second aspect of the present invention, there is provided a blade for a compressor, wherein the space has a non-communication structure with at least one of a high pressure side and a low pressure side of the compression chamber.

According to the third aspect of the present invention, the porosity of the space portion is
A compressor blade having a volume ratio of 40% or less with respect to the blade cross section is provided.

According to a fourth aspect of the present invention, there is provided a compressor blade in which a space is formed continuously from a suction side to a discharge side and has a configuration closed at an end on the suction side.

According to a fifth aspect of the present invention, a blade is formed by injection molding by applying a melt-type fluororesin as a blade material, and the injection molding is performed by a gas assist for injecting a high-pressure inert gas from a molding nozzle or a mold. Provided is a method for manufacturing a blade to be formed.

According to a sixth aspect of the present invention, there is provided a compressor blade manufactured by the blade manufacturing method, wherein the blade material is a molten type fluororesin, an inorganic fibrous filler, a solid lubricant, an organic filler. And a compressor blade made of a composite material filled with at least one of the above.

In the present invention, PFA resin, perfluoroethylene propylene resin (FEP resin), ethylene tetrafluoroethylene resin (ETFE resin) and the like are preferable as the melt type fluororesin.

The fillers include inorganic fibers, solid lubricants, and organic fillers. Specifically, glass fibers, carbon fibers (PAN, pitch), graphite fibers, alumina fibers, wollastonite, potassium titanate whiskers, carbon whiskers, silicon carbide whiskers, and the like can be used as the inorganic fibers.

Further, as a solid lubricant, molybdenum disulfide, graphite, carbon, boron nitride, bronze, etc., and as an organic filler, a wholly aromatic polyester resin, a polyimide resin, a bismaleimide resin, a silicon resin, a phenol resin. And the like.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(First Embodiment) FIG. 1 is a sectional view showing the structure of a compression element in a helical blade compressor. As shown in FIG. 1, the compression element of the helical blade compressor includes a cylindrical cylinder 11, a helical blade 12 arranged along the inner peripheral surface of the cylinder 11, and the blade 12 fitted. And a piston 14 having a spiral groove 13. Spiral groove 1
3 is formed gradually smaller from the refrigerant inlet side to the refrigerant outlet side, and the refrigerant gas is compressed in the compression chamber 1 formed between the cylinder 11, the blade 12 and the piston 14.
At 5, the fluid is compressed while flowing from the low pressure (Ps) side to the high pressure (Pd) side.

FIG. 2A is a front view showing the external shape of the blade 12 shown in FIG. 1, and FIG.
FIG. 3C is a right side view. FIG. 3 is a perspective view of the blade 12 partially shown in section, and FIG. 4 is an enlarged sectional view showing a contact state between the blade 12 and the edge 13 a of the spiral groove 13. As shown in these figures, the blade 1
Numeral 2 is formed, for example, in a helical shape with a constant pitch, and has a hollow structure with a rectangular cross section having a space 16 inside. The space 16 of the blade is partially open, for example, facing the high pressure (Pd) side, and is closed on the low pressure (Ps) side. That is, the space 16 communicates with the high-pressure side pressure chamber, but is not in communication with the low-pressure side pressure chamber.

The material of the blade 12 has a density of 2.1.
(G / cm ³ ) PTFE resin (trade name: Mitsui / Dupont Fluorochemical, 7-J). The manufacturing method is to extrude a hollow square material having an internal space, then wind it around a mold and heat-mold it. The method was adopted.

The blade 12 of the present embodiment has the space portion 16 so that flexibility is increased, and the blade 12 can easily enter and exit the spiral groove 13. Also, as shown in FIG.
The blade 12 was deformed along the R-plane of the edge portion 13a of the spiral groove 13 in the form of the side wall movement, thereby increasing the contact area. Therefore, the surface pressure applied to the blade 12 was reduced, and the reliability of the blade 12 was improved. Also, the space 16 communicates with the pressure chamber on the high pressure side, so that the space 16
It was confirmed that the internal pressure according to the usage conditions of the compressor acted on the blade 12, and the cross-sectional shape of the blade 12 was not deformed by the pressure, and a constant shape was maintained. With the above functions, the compressor of this embodiment has improved compressor performance and improved reliability.

As a comparative example, as shown in FIG. 8, a blade having a space 16 shielded from the outside was prepared and a function comparison was performed. And it was recognized that the blade cross-sectional shape was deformed by pressure.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention. In the present embodiment, the space 16 of the blade 12 is open at the low-pressure end and the high-pressure end, but the space 16 is closed at substantially the middle in the length direction of the blade 12. In addition, as shown in FIG. 6, as a comparative example, a blade 17 in which the space 16 was opened to the outside at the low pressure side end and the high pressure side end was prepared.

In the blade 12 of this embodiment shown in FIG. 5, the high-pressure gas and the low-pressure gas in the compression chamber 15 are guided to the intermediate position where the space 16 is closed. Does not leak refrigerant gas, and the sealing function between the rooms is not impaired. However, the blade 17 of the comparative example shown in FIG.
Since the gas on the side was guided to the low pressure (Ps) side, the leakage of the refrigerant gas was remarkable, and the compressor performance was reduced.

In this embodiment, the space 16
Are formed at both ends of the blade 12, but it is also possible to form them on the sealing surface in the middle of the spiral. However, since the outer peripheral surface and the side surface of the blade 12 are slid, the opening is preferably formed on the inner peripheral surface of the blade 12. In this case, if the formation of the open portion on the seal surface is 2 or more, the open portion of the space portion 16 communicates with the compression chamber 15, and the refrigerant gas leaks as in the comparative example shown in FIG. Since a decrease is caused, it is desirable to set it to 1.

(Third Embodiment) In the present embodiment, in the blade 12 similar to the first embodiment shown in FIG. 1, the sectional area of the space 16 with respect to the sectional area of the blade is 10 to 50.
% And the compressor performance was measured and compared with the conventional blade 2 without space. That is, the compressor coefficient of performance was compared with the refrigerating machine oil (trade name: 4GSD) using HCFC22 refrigerant at a motor rotation speed of 60 rps.

Table 1 shows that the coefficient of performance of the conventional blade is 10
The measurement results are shown in the relative ratio when 0 is set. As shown in Table 1, the peak of the case where the area of the space 16 is 30%, the compressor coefficient of performance decreases, and
At 0%, the result was remarkably reduced, and the result was inferior to the conventional blade.

When the blade 12 having 50% of the space portion was taken out and observed, deformation occurred such that the surface dropped to the space portion 16 as shown in FIG. This is the space 1
It is considered that the cross-sectional strength of the blade 12 decreased due to the increase in the cross-sectional area of the blade 6, and the blade 12 buckled and deformed due to the pressure difference. However, when the area of the space portion 16 is 40% or less, a higher coefficient of performance than that of the conventional blade is obtained. It is considered that the friction loss at the time of the reduction was reduced. That is,
An effective effect is exhibited when the space area is 40% or less, and particularly preferably 20 to 30%.

(Fourth Embodiment) In the present embodiment, the blade 12 similar to the first embodiment shown in FIG. 1 has a space area ratio of 30 continuously from the high pressure side end to the low pressure side end.
% Of the space 16 was formed, and the low pressure side was closed at the end so as not to communicate with the compression chamber. As a comparative example,
Although not shown, a blade having a high pressure side end closed and a conventional solid blade 2 were prepared, and the compressor performance was measured. Measurement and configuration conditions were the same as in the third embodiment.

Table 2 shows that the coefficient of performance of the conventional blade is 10%.
The measurement results are shown in the relative ratio when 0 is set. As shown in Table 2, the blade 12 of the present embodiment has the highest coefficient of performance of the compressor and high efficiency.
This is presumably because the high pressure gas is led to the low pressure side to expand the blade cross section by utilizing the differential pressure, thereby improving the sealing performance. As described above, if the clearance is increased in consideration of the thermal expansion of the fluororesin and the swelling due to the refrigerant gas, a predetermined compressor performance cannot be obtained at the time of starting or the like. In particular, the large pitch on the suction side is the blade 1
The elastic deformation when the 2 enters and exits the spiral groove 13 is large, and the sealing property is an important part. Blade 12 of the present embodiment
Then, the lower the pressure side, the greater the differential pressure, and sufficient sealing performance can be obtained.

On the other hand, in the blade of the comparative example in which the open end of the space 16 is reversed to that of the present embodiment, the low-pressure gas is guided to the high-pressure side, so that the blade deforms in the direction in which the blade contracts on the high-pressure side. And the sealing performance is reduced. However, the hollow effect was obtained, and the compressor performance was improved as compared with the conventional blade.

(Fifth Embodiment) FIGS. 9 to 11 are explanatory views showing an embodiment of a blade manufacturing method according to the present invention. In this embodiment, blade forming is performed by gas assist molding. FIG. 9 shows a type having two resin filling ports (gates) 20 (two-gate method).
A method of injecting an inert gas, for example, a nitrogen gas (N ₂ ) from a nozzle 25 of an injection molding machine 24 having a screw 23 using the mold 21 and the core 22 of FIG. FIG.
0 uses the mold 21 and the core 22 of the 1 gate method,
A method of injecting nitrogen gas from the end of the blade 12 on the mold fixing side is shown. FIG. 11 shows a method of injecting nitrogen gas from the end of the blade 12 on the mold fixed side using a one-gate mold 21 and a core 22.

The gas assist molding in the present embodiment
9 to 1 by connecting the unit to a normal injection molding machine 24.
In this method, high-pressure nitrogen gas (max. 300 kg / cm ² ) is injected into the product part from the inside of the nozzle 25 and the mold 21 as shown in FIG. By using the gas assist molding, the space 16 described above can be easily formed in the blade 12.

In order to compare the dimensional accuracy obtained by this gas assist molding, the gas assist molding method of FIG. 9 in which the resin is filled from both ends of the blade and the gas assist molding method of FIG. 10 in which the resin is filled from one end of the blade. Thus, each blade 12 was prepared. In contrast to this, other blades were prepared by ordinary injection molding, and the respective dimensions were measured. FIG. 12 and FIG. 13 show the undercut (the difference between the inner and outer circumferences and the center of the width) of the cross section of the blade created by gas assist molding and normal injection molding.

The material used is a PFA resin (trade name: Mitsui DuPont Fluorochemical, 340-J) having a density of 2.1 (g / cm ³ ) and a melt flow rate of 13 (g / 10 minutes). Specifically, the molding machine uses 80 ton (Toshiba Machine Co., IS80EPN), and the molding conditions are molding temperature 3
80 ° C., mold temperature 200 ° C., filling speed 3 cm / sec (screw position).
g / cm ² . In gas assist molding, a resin equivalent to 70% of the amount of resin used is filled, and the gas pressure is reduced to 18%.
The condition was 0 kg / cm ² .

As shown in FIG. 12, it is recognized that the gas-assisted molding hardly loses the thickness, but that the normal injection molding causes a large thickness loss in the center of the blade 12. Similarly, in the case shown in FIG. 13, the thickness of the end opposite to the gate 20 in the normal injection molding was large, and was larger than that of the blade 12 filled from both ends.

As shown in FIGS. 21 and 22, the mechanism of the occurrence of meat thinning is that the inside is cooled after the blade surface is individualized, and the surface is pulled inward by volume shrinkage at that time. by. In particular, since the fluororesin has a characteristic that the molding shrinkage is large, the flesh is remarkably exhibited. The helical blade 12 has a sealing surface on the front surface due to its function, and a gate 20 filled with resin.
When the spiral is provided in the middle of the spiral, the smoothness of the surface is impaired. Therefore, it is necessary to install the gate 20 at the end of the blade as described above. As a result, the flow length of the resin is increased, and a situation occurs in which the filling pressure is not sufficiently transmitted to the terminal, which causes a further increase in the thickness of the portion opposite to the gate 20. I have.

On the other hand, in the case of gas-assist molding, high-pressure gas is injected into the blade 12, which is a molded product, and the blade 12 is held and cooled by the gas pressure from the inside. Further, in the case of gas assist molding, the pressure gradient is smaller than in normal injection molding, and the pressure becomes almost uniform at any position of the spiral, and low pressure molding becomes possible. In addition, the flow length of the gas in gas assist is largely affected by the flow characteristics of the material and the volume shrinkage (the gas is injected by an amount corresponding to the volume shrinkage). It can be said that the material is suitable for gas assist molding.

Next, molding was carried out by a two-gate method shown in FIG. 9 at a filling pressure of 900 kg / cm ² and a filling speed of 6 cm / sec for the purpose of improving the sink by ordinary injection molding. FIG.
Indicates the effect on the above molding conditions in comparison with both the ground meat.

In this method, as shown in FIG. 14, the amount of minced meat decreased. However, peeling between the skin layer and the core layer was observed, and irregularities were generated on the surface, resulting in impaired smoothness. In other words, for the blade 12 that requires a large flow length of the resin and requires a high degree of dimensional accuracy, the injection molding using the fluororesin is limited in terms of conditions, and it is difficult to obtain the sink and surface smoothness. . On the other hand, the surface defect is caused by the shear stress between the mold surface and the fluid resin. In the gas assist molding, the solid resin is molded at low pressure by the gas pressure inside the cross section, and the shear stress near the surface is reduced. Therefore, there is an advantage that surface defects are less likely to occur.

Next, the blade 12 compared with the amount of lightening shown in FIG. 12 was aged at 200 ° C. for 24 hours, and the size was measured again assuming a temporal change of the blade size (to avoid the effect of lightening). , Perimeter dimensions).
FIG. 15 shows a dimensional change amount (a dimensional comparison between after molding and after aging).

As shown in FIG. 15, it can be seen that the size near the gate 20 is increased in the ordinary injection molding. On the other hand, almost no dimensional change is recognized in the gas assist molding. This is due to the pressure gradient of the filling pressure,
Resin density distribution and residual stress are reduced by aging,
It is considered to lead to dimensional change, which is the effect of the equal pressure and low pressure molding of gas assist molding.

That is, the blade 12 formed by gas-assist molding using a molten fluororesin can easily form a space, and is excellent in dimensional accuracy, surface smoothness, and dimensional stability. It is.

(Sixth Embodiment) In the present embodiment, the suitability of gas assist molding is examined. That is, as described above, for the purpose of improving the abrasion resistance of the blade 12, a fluororesin composite material containing a filler is used, but these composite materials reduce the fluidity of the resin in injection molding. Let it. A decrease in fluidity deteriorates the moldability and causes dimensional defects. Therefore, in the present embodiment, the suitability of the gas assist molding according to the present invention for these problems was examined.

The material was a PFA resin (trade name, Mitsui DuPont Fluorochemical, 340-J) having a density of 2.1 (g / cm ³ ) and a melt flow rate of 13 (g / 10 minutes), and carbon fiber (trade name). , Toray Milled Fiber Trading Card MLD
-30) was blended in an amount of 5% by weight and 10% by weight, and a molding experiment was performed by a two-gate method shown in FIG. The molding conditions were in accordance with the fifth embodiment. Table 3 shows the melt flow rate which is a measure of the moldability of the material.

FIG. 16 shows a comparison between the blade 12 produced by the gas-assist molding method and the blade molded by the usual injection molding method. As shown in FIG. 16, the normal injection molding blade has a large sink in the center, and the greater the carbon fiber content, the greater the sink. This is because, as can be seen from the mail flow rate in Table 3, the fluidity is poor, so that the flow resistance between the resin and the mold surface increases, the pressure loss increases, and the transmission of pressure to the terminal ends increases. It deteriorated, and as a result, the undercut became large, resulting in dimensional defects.

On the other hand, in the gas assist molding, as described in the fifth embodiment, since the pressure is uniformly formed from the inside of the spiral by the flow of the gas, the influence of the fluidity of the material is smaller than in the ordinary injection molding. With small advantages. Therefore, by using the gas assist molding, high dimensional accuracy can be obtained even if a filler is added for the purpose of improving the wear resistance of the material, and the sealing property, which is a function of the blade 12, can be secured. Further, although the rigidity of the material is increased by the blending of the filler, the ingress and egress properties are improved by the formation of the space, and the surface pressure of the edge portion 13a of the spiral groove 13 is reduced, so that high compressor performance and reliability are achieved. can get.

As the filler, inorganic fibers, solid lubricants and organic fillers can be used. Specifically, glass fibers, carbon fibers (PAN, pitch), graphite fibers, alumina fibers, wollastonite, potassium titanate whiskers, carbon whiskers, silicon carbide whiskers, and the like can be used as the inorganic fibers. In addition, as a solid lubricant, difluidized molybdenum, graphite, carbon,
Organic fillers such as boron nitride and bronze include wholly aromatic polyester-based resins, polyimide-based resins, bismaleimide-based resins, silicone resins, phenolic resins, and the like.

In the method of the present invention, the cooling of the cross section is accelerated by the gas assist molding, which leads to shortening of the molding cycle. In addition, the hollow material has a large productivity effect such as an improvement in material yield.

According to the above embodiment, by providing the space 16 which is partially communicated with the compression chamber 15 in the helical direction of the blade 12, it is easy to enter and exit the helical groove 13. The concentrated stress received at the edge portion 13a of the thirteen decreases due to an increase in the contact area due to elastic deformation, and wear of the blade can be reduced. In addition, by introducing the refrigerant gas on the high pressure side to the space 16, the cross section can be expanded by utilizing the differential pressure, and the sealing performance can be improved.

According to the manufacturing method, the space 16 can be easily formed by using the gas assist molding, and the cross-sectional thinning caused by the heat shrinkage second characteristic, which is a defect of the fluororesin, can be reduced. The uniformity of the density distribution and the effect of the reduction of the residual stress by the low-pressure / uniform-pressure molding provide high dimensional accuracy and minimize the dimensional change over time. Further, productivity can be improved, such as improvement of material yield and shortening of molding cycle.

On the material side, the space portion is easily formed on the contrary due to the large heat shrinkage of the fluororesin. In addition, since fluorocarbon resin has high viscoelastic properties due to its high melting clay, in normal injection molding, the surface (skin layer) and the inside (core layer) are peeled off due to the shear stress between the mold surface and the resin. Although phenomena such as roughness (delamination) occur, sliding characteristics are impaired. However, according to the above molding method, pressure molding can be performed with nitrogen gas, so that flow on the mold surface is small and shear stress is minimized. The above phenomenon can be prevented.

In addition to the above-mentioned helical compressor, the present invention can be applied to a tip seal of a scroll compressor having a function similar to a spiral blade, a tip seal of a recently proposed 3D scroll compressor, and the like. These do not enter or exit the helical groove as in a helical compressor, but they are common in that they are slid by a seal member, have a long seal length, and require dimensional accuracy. That is, the effect of using gas-assist molding for the purpose of obtaining dimensional accuracy is the same as that of the material made of molten fluororesin.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

As described in detail in the above embodiment, according to the compressor blade according to the present invention, the helical direction is provided by providing a space partly communicating with the compression chamber in the helical direction of the fluorine resin blade. The groove can be easily moved in and out, and the concentrated stress applied to the edge of the spiral groove due to the differential pressure is reduced by the increase in the contact area due to the elastic deformation, and the wear of the blade can be reduced. In addition, by introducing the refrigerant gas on the high pressure side to the space, the cross section can be expanded by utilizing the differential pressure, and the sealing performance can be improved.

According to the blade manufacturing method of the present invention, the space can be easily formed by using the gas assist molding, and the cross-section thinning caused by the heat shrinkage second characteristic which is a drawback of the fluororesin. Can be reduced, high dimensional accuracy can be obtained by the effects of uniformizing the density distribution and reducing the residual stress by low-pressure / uniform-pressure molding, and the dimensional change over time can be minimized. Further, productivity can be improved, such as improvement of material yield and shortening of molding cycle.
On the material side, the space portion is easily formed on the contrary due to the large heat shrinkage of the fluororesin. In addition, since fluorocarbon resin has high viscoelastic properties due to its high melting clay, normal injection molding causes phenomena such as surface and internal peeling and surface roughness due to the shear stress between the mold surface and the resin. Although the sliding characteristics are impaired, according to the method of the present invention, since pressure molding can be performed with an inert gas gas, the flow on the mold surface is small, the shear stress can be minimized, and the above phenomenon is prevented. be able to.

[Brief description of the drawings]

FIG. 1 is an overall sectional view showing a first embodiment of a compressor blade according to the present invention.

2A is a diagram showing an external shape of the blade shown in FIG. 1, FIG. 2B is a left side view, and FIG. 2C is a right side view.

FIG. 3 is a perspective view showing a partial cross section of the blade shown in FIG. 2;

FIG. 4 is an enlarged sectional view showing a contact state between the blade shown in FIG. 1 and an edge of a spiral groove.

FIG. 5 is an overall sectional view showing a second embodiment of a compressor blade according to the present invention.

FIG. 6 is a sectional view showing a comparative example with respect to the embodiment.

FIG. 7 is an explanatory view showing a deformed state of the blade.

8A is a diagram showing a comparative example of the embodiment, FIG. 8B is a left side view, and FIG. 8C is a right side view.

FIG. 9 is an explanatory view showing an embodiment of a blade manufacturing method according to the present invention.

FIG. 10 is an explanatory view showing an embodiment of a blade manufacturing method according to the present invention.

FIG. 11 is an explanatory view showing an embodiment of a blade manufacturing method according to the present invention.

FIG. 12 is a characteristic diagram of the amount of meat reduction showing the effect of the present invention.

FIG. 13 is a characteristic diagram of the amount of thinning showing the effect of the present invention.

FIG. 14 is a characteristic diagram of the amount of thinning showing the effect of the present invention.

FIG. 15 is a characteristic diagram of a dimensional change showing the effect of the present invention.

FIG. 16 is a characteristic diagram of the amount of thinning showing the effect of the present invention.

FIG. 17 is a diagram showing a conventional blade configuration.

18A is a diagram showing an external shape of the blade shown in FIG. 17, and FIG. 18B is a right side view.

19 is a perspective view showing the blade shown in FIG. 18 in a partial cross section.

FIG. 20 is an enlarged cross-sectional view showing a contact state between the blade shown in FIG. 17 and an edge of a spiral groove.

FIG. 21 is a cross-sectional view showing a state during forming of a conventional blade.

FIG. 22 is a cross-sectional view showing a state in which a conventional blade is thinned.

[Explanation of symbols]

 11 Cylinder 12 Blade 13 Spiral Groove 14 Piston 15 Compression Chamber 16 Space

Claims (6)

[Claims] 1. A helical fluorine resin blade constituting a compression element of a compressor, wherein the helical fluorine resin blade has a space inside the helical direction, and a part of the space communicates with a compression chamber. A compressor blade characterized by the following. 2. The compressor blade according to claim 1, wherein the space has a non-communication structure with at least one of a high pressure side and a low pressure side of the compression chamber. 3. The blade for a compressor according to claim 1, wherein the porosity of the space is not more than 40% in volume ratio with respect to the cross section of the blade. 4. The compressor blade according to claim 1, wherein the space is formed continuously from the suction side to the discharge side, and is closed at an end on the suction side. For blades. 5. A method for manufacturing a compressor blade according to claim 1, wherein the blade is formed by injection molding using a molten type fluororesin as a blade material. A method for producing a blade, wherein the molding is gas-assist molding in which a high-pressure inert gas is injected from a molding nozzle or a mold. 6. The compressor blade according to any one of claims 1 to 4, which is manufactured by the blade manufacturing method according to claim 5, wherein the blade material is an inorganic fibrous resin in a molten type fluororesin. A compressor blade comprising a composite material filled with at least one of a filler, a solid lubricant, and an organic filler.