JP3573928B2 - Compressor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a compressor capable of easily performing uniform fixing without using a flux or the like when a suction pipe or the like made of a material having a different melting point is fixed to a case or the like accommodating a compression mechanism.
[0002]
[Prior art]
The refrigeration system is used in various technical fields, and has a compressor, a condenser, an expansion valve, an evaporator and the like as main components, and operates a refrigeration cycle and a heat pump. For example, in a refrigeration cycle, a refrigerant is compressed by a compressor into hot gas, and then the hot gas is heat-exchanged with outside air or the like by a condenser to become a liquefied refrigerant. Then, the liquefied refrigerant is expanded by an expansion valve to lower the temperature, and exchanges heat with a load in an evaporator. Thereby, the load is cooled.
[0003]
FIG. 5 is a perspective view showing the external appearance of the compressor 1. The refrigerant is sucked into the compressor 1 through a suction pipe 2, and the compressed refrigerant is discharged through a discharge pipe 3 to the above-described condenser or the like. Is discharged.
[0004]
In general, the suction pipe 2 and the discharge pipe 3 are made of copper, and the case 4 of the compressor 1 is made of iron. The case 4 is formed with a hole having substantially the same diameter as the external dimensions of the suction pipe 2 and the like. The suction pipe 2 and the like are fixed thereto by silver brazing. FIG. 6 is a cross-sectional view when the suction pipe 2 is brazed to the case 4 with a silver braze 5.
[0005]
When performing silver brazing, a flux is used. The flux penetrates into a sliding portion or a compressed portion to damage the sliding surface, or ether oil or lubricating oil used for lubricating the compressor 1 is used. Since there is a disadvantage that the ester oil or the like is decomposed, it is removed by washing after brazing.
[0006]
[Problems to be solved by the invention]
However, since the flux after brazing is firmly attached to the brazing surface, it cannot be removed merely by washing, but is removed by using brushing or the like. Therefore, there is a problem that the flux remains in the inside of the case 4 or in a small gap where it is difficult to perform brushing.
[0007]
Also, the flux penetrated between the suction pipe 2 and the case 4 during the brazing step, and the flux was removed by subsequent washing or the like.
[0008]
In addition, silver brazing generally has many pinholes, making it difficult to keep the inside of the case 4 airtight and causing many problems such as leak failure.
[0009]
For such silver brazing, it is conceivable to use arc welding or the like which does not require a flux and is suitable for confidentiality. However, such a method is to melt members having greatly different melting points almost simultaneously. Therefore, it cannot be used for welding between the members.
[0010]
Accordingly, an object of the present invention is to provide a highly reliable compressor that can be welded by a method that allows for confidentiality without using flux when connecting members made of metals having different melting points. And
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a hole is formed in at least one of a case for accommodating a compression mechanism, a bottom serving as a bottom of the case, and an end cap to be fixed to an end cap serving as a head of the case. In a compressor in which a pipe-shaped fixed object made of a material having a different melting point from the material of the fixed object is fixed in a hole, the fixed object is subjected to plastic working (for example, buckling buckling, etc.) to form a flat surface. And forming a hole in the plane portion. In addition, pulse welding is performed in a state where the adhered object and the adhered object are uniformly in close contact with each other.
[0012]
According to a second aspect of the present invention, a hole is formed in at least one of a case accommodating the compression mechanism, a bottom serving as a bottom of the case, and an end cap serving as a head of the case. The hole is formed by burring in a compressor in which a pipe-shaped fixed object made of a material having a different melting point from the above material is fixed to the hole. At this time, an annular rib is formed like a burr around the hole simultaneously with the formation of the hole. Therefore, the present invention is characterized in that the fixed material is urged against the rib with a predetermined force to perform pulse welding.
[0013]
When a hole is formed by burring, a rib is formed at the same time as the hole, and the root of the rib inside the hole has a predetermined curvature. Therefore, during pulse welding, the electrode surface of the electrode connected to the object to be fixed is made to have the same curvature as the curvature of the root to support a predetermined urging force on the object and reduce the contact resistance between the electrode and the rib. And a uniform resistance.
[0014]
According to a third aspect of the present invention, the inside of the welded portion of the fixed object is chamfered into a tapered shape that becomes thinner toward the tip, and the fixed object and the object are in point contact with each other at the start of pulse welding. In addition, the molten material at the point contact portion protrudes laterally (outside) by the force applied to the adhered material, thereby suppressing the generation of spatters and burrs on the inside and performing welding with uniform strength. I do.
[0015]
The invention according to claim 4 is characterized in that the diameter of the hole is set to be larger than the inner diameter of the fixed object and smaller than the outer diameter, so as not to cause extra flow resistance of the refrigerant gas.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Prior to the description of embodiments of the present invention, a welding technique used in the present invention will be described. The welding technique used in the present invention is called pulse welding, in which a workpiece is urged to a workpiece with a predetermined force, and a pulse current of 4 to 12 milliseconds / tens of thousands of amperes is applied during the welding to perform welding. It is a type of resistance welding, and has the characteristic that different metals can be welded because the metal melts instantaneously.
[0017]
In each of the embodiments described later, a case where a suction pipe (weld) is welded to a case (weld) will be described. However, the present invention is not limited to this. The present invention is also applicable to a case where a pipe of a dissimilar metal is welded to a bottom or an end cap.
[0018]
In general, iron or the like is used as the material of the case, and copper is used as the material of the pipe. However, the present invention is not limited to these materials, but requires that the metal be a dissimilar metal.
[0019]
Further, in the following description, a hole formed in a workpiece is described as a perfect circle, but the present invention is not limited to a perfect circle, and an elliptical hole, a square hole or the like does not lose generality. The same can be said for weldments. Therefore, in this specification, the term “hole” includes all holes such as a perfect circular hole, an elliptical hole, and a square hole.
[0020]
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view including a suction pipe 14 in a compressor 10 according to the present embodiment, in which a motor and the like disposed inside are not shown.
[0021]
The case 11 is burred from the inside to the outside of the case 11 to form a hole 12. By the burring process, an annular rib 13 is formed around the hole 12. At this time, a peripheral portion 15 of the rib 13 inside the case 11 has a predetermined curvature.
[0022]
Then, one electrode of the pulse welding is brought into contact with the periphery of the hole 12 from the inside of the case 11, and a pulse current flows between the case 11 and the suction pipe 14 while pressing the suction pipe 14 with a predetermined force. Thereby, these contact surfaces are melted and welded.
[0023]
At this time, if the electrode to be brought into contact with the inside of the case 11 is in contact with a place far from the hole 12, the case 11 other than the welded portion is heated, which is not preferable from the viewpoint of effective use of electric power. Further, if the contact between the electrode and the case 11 is a point contact or the contact area is small, the current density in the portion becomes high and the electrode itself may be welded.
[0024]
From these circumstances, it is necessary to make the electrode uniformly contact the periphery of the hole 12, and it is preferable to perform pulse welding using the electrode 16 as shown in FIG. The electrode 16 shown in the figure has an electrode surface 17 set to the same curvature as the curvature of the peripheral portion 15 inside the case 11 of the hole 12 formed by burring.
[0025]
When such an electrode 16 is addressed to the hole 12, the electrode 16 is inserted into the hole 12, and the peripheral portion 15 of the hole 12 comes into surface contact with the electrode surface 17. And the case 11 can have a small contact resistance and a uniform resistance distribution. Further, the force applied to the suction pipe 14 can be favorably supported by the electrode 16 which is in surface contact with the rib 13.
[0026]
When the ribs 13 are formed by burring, the end surfaces 13a of the ribs 13 have a saddle-shaped shape depending on the case 11, since the case 11 has a cylindrical shape. Therefore, when the welding surface of the suction pipe 14 is flat, the rib 13 and the suction pipe 14 come into point contact at the start of welding. Such a situation also occurs when one of the welding surfaces of the workpiece and the workpiece is a curved surface, and when pulse welding is performed in such a point contact state, there is a concern that a distribution of welding strength may occur. .
[0027]
However, the point contact portion instantaneously exceeds the melting point and is inhaled because the current density at the point contact portion is large, the thickness of the rib 13 is thin, and a predetermined force is applied to the suction pipe 14. The suction pipe 4 is easily spread in the radial direction (lateral direction) by the force applied to the pipe 4 and comes into a surface contact state. Therefore, the welding strength distribution can be regarded as substantially uniform over the entire welded portion.
[0028]
In order to ensure such a high degree of uniformity of the welding strength, a method of forming a taper in the welded portion of the rib 13 or the suction pipe 14 to accelerate the melting at the point contact portion may be used together. FIG. 3 shows such a method in which a welded portion 18 chamfered in a tapered shape in which the inside of the suction pipe 14 becomes thinner toward the tip is provided.
[0029]
The suction pipe 14 shown in the figure is a case where the inside of the welded portion 18 is chamfered. However, according to the purpose of the above description, the outside of the suction pipe 14 is chamfered, and has a tapered shape like a pencil lead. It is also possible to
[0030]
However, the point contact portion is melted first and then protrudes laterally by the force applied to the suction pipe 14, so that the melted portion protrudes inside the welded portion 18, ie, inside the suction pipe 14. Will be lost. This is not preferable because it acts as a flow resistance of the refrigerant flowing in the suction pipe 14. In addition, when used for a long time, the protruding part may be chipped and fall into a movable part such as the compressor 10 to damage the movable part.
[0031]
Therefore, in the present invention, the protruding molten portion is covered with the molten portion 18 or the welded portion 18 chamfered is restored to the shape before chamfering, with the configuration shown in FIG. . This makes it possible to reduce the work of removing the protruding molten portion.
[0032]
As described above, according to the above configuration, even if one of the surfaces to be welded is not flat and the members to be welded are not the same kind of metal, welding can be performed with uniform strength. The reliability and work efficiency are improved.
[0033]
Next, a second embodiment of the present invention will be described with reference to the drawings. In addition, about the same structure as 1st Embodiment, description is abbreviate | omitted suitably using the same code | symbol.
[0034]
In the first embodiment, the ribs 13 are formed by burring to make the welding strength and the like uniform, but in the present embodiment, the case 11 is pushed or pushed from the inside to the outside. Conversely, a flat portion is formed by buckling from the outside to the inside, a hole 12 is formed in the flat portion, and the suction pipe 14 is pulse-welded.
[0035]
That is, as shown in FIG. 4, a flat portion 23 is formed in the case 21 of the compressor 20 by being pushed from the inside to the outside of the case 21. A hole 24 is formed in the flat portion 23 by punching using a technique such as punching or punching.
[0036]
Since the ribs 13 generated by burring do not occur in the holes 24 formed in this manner, the entire welded portion of the suction pipe 22 can be brought into close contact with the flat portion 23 from the start of welding. Therefore, uniform welding can be performed.
[0037]
In this case, the electrode inside the case 21 may be a flat electrode surface instead of the electrode surface 17 having a predetermined curvature as described in the first embodiment. Therefore, the versatility of the electrode can be maintained.
[0038]
Further, as described in the first embodiment, the molten portion protrudes when the suction pipe 22 is pressed against the case 21. In this case, the diameter D3 of the hole 24 is set to be equal to the inner diameter D1 of the suction pipe 22. Intermediate size with the diameter D2, ie
D1 <D3 <D2 (1)
It is preferable to set
[0039]
Thereby, the region of D3-D2 becomes a welded portion, and the region of D3-D1 becomes a region for covering the protruding molten member.
[0040]
Of course, instead of such a configuration, a chamfered configuration as shown in FIG. 3 is also possible.
[0041]
As described above, in this specification, the hole is not limited to a perfect circle. Therefore, Equation 1 is a condition when the hole 24 is a perfect circle, and a general condition is to satisfy a dimensional relationship in which a hole is included in a cross section of a pipe-shaped welded product.
[0042]
As described above, according to the above configuration, even if the work to be welded is not a flat surface, the work is pressed to form a flat surface, so that the workability of welding is facilitated and improved. Since welding can be performed with uniform strength, reliability is improved.
[0043]
【The invention's effect】
As described above, according to the first aspect of the present invention, a portion where a hole is formed is formed into a flat portion by plastic working, and a hole is formed in the flat portion to perform pulse welding. Even when the melting point of the workpiece and the workpiece is different, welding can be performed simply and efficiently with substantially uniform strength without using flux or the like.
[0044]
According to the second aspect of the present invention, the rib is formed at the same time as the drilling by burring, and the weld is urged to the rib with a predetermined force to perform pulse welding. The molten material at the contact portion protrudes, thereby making it possible to perform welding with uniform strength.
[0045]
Furthermore, since the shape of the electrode surface of the electrode connected to the workpiece during pulse welding is made the same as the curvature of the root of the rib, the contact resistance between the electrode and the rib during pulse welding can be reduced. In addition, the current density distribution can be improved, and the biasing force for the welded object can be suitably supported because the electrode is in surface contact with the rib, and welding with uniform strength can be easily performed.
[0046]
According to the third aspect of the present invention, since the inside of the welded portion of the welded article is formed to have a widened shape, even if the welded article and the workpiece are in point contact, the point applied by the force applied to the welded workpiece is reduced. The molten material at the contact portion protrudes and welding with uniform strength can be performed.
[0047]
According to the fourth aspect of the invention, since the diameter of the hole is set to be larger than the inner diameter and smaller than the outer diameter of the welded material, it is possible to prevent an extra flow resistance of the refrigerant gas from being generated, and to add to the welded material. The protruding molten material is covered by the side wall of the hole and the end face of the welded material inside the hole due to the applied force, and the removal of the protruding molten material becomes unnecessary, thereby reducing the cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a compressor applied to a description of a first embodiment of the present invention.
FIG. 2 is a side view of a pulse welding electrode.
FIG. 3 is a sectional view of a suction pipe.
FIG. 4 is a cross-sectional view of a compressor applied to a description of a second embodiment of the present invention.
FIG. 5 is an external perspective view of a compression applied to the description of the prior art.
FIG. 6 is a cross-sectional view of a compressor applied to a description of a problem of the related art.
[Explanation of symbols]
10, 20, 30 Compressors 12, 24, 33 Holes 11, 21, 31 Case 13 Ribs 14, 22, 32 Suction tube 15 Rib base 16 Electrode 17 Electrode surface 18, 34 Welded part 23 Flat part

Claims (4)

A hole is formed in at least one of a case for accommodating the compression mechanism, a bottom serving as a bottom of the case, and an end cap to be fixed to the end cap serving as a head of the case, and a material having a melting point different from that of the material of the fixed object. In a compressor having a pipe-like fixed substance consisting of
A compressor, wherein a flat portion is formed in the fixed object, the hole is formed in the flat portion, and the fixed object is pulse-welded to the hole. A hole is formed in at least one of a case for accommodating the compression mechanism, a bottom serving as a bottom of the case, and an end cap to be fixed to the end cap serving as a head of the case, and a material having a melting point different from that of the material of the fixed object. In a compressor having a pipe-like fixed substance consisting of
The hole is formed by burring, and a rib is formed around the hole at the same time as the hole is formed, and the fixed object is urged to the rib with a predetermined force to perform pulse welding.
The electrode connected to the object to be fixed at the time of the pulse welding has an electrode surface having the same curvature as the curvature of the inner root of the annular rib, and the electrode surface is brought into contact with the root of the rib. A compressor characterized by pulse welding. The compressor according to any one of claims 1 to 2, wherein the inside of the welded portion of the fixed object is chamfered in a tapered shape. The compressor according to any one of claims 1 to 3, wherein the diameter of the hole is set to be larger than the inner diameter of the fixed object and smaller than the outer diameter.

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