The present invention relates to a method for manufacturing a supercharger compressor housing, and to a supercharger compressor housing.
As an auxiliary apparatus configured to efficiently compress an intake air sucked into an internal combustion engine, a supercharger is used. The supercharger includes a compressor housing, a compressor impeller supported inside the compressor housing so as to be freely rotatable, and driving means connected to the compressor impeller by way of a shaft. As the driving means, there has been used a turbine impeller, which is rotated by an exhaust gas discharged from the internal combustion engine, the internal combustion engine, an electric motor, or other means.
When the compressor impeller is rotated by the driving means, the intake air is fed into the internal combustion engine after being compressed. At this time, a plurality of blades that are formed on an edge portion of the compressor impeller to extend along an inner wall surface (shroud surface) of an intake passage in the compressor housing suck and forcibly feed the intake air. Therefore, in order to improve compression efficiency for the intake air, a gap that is formed between the shroud surface of the compressor housing and distal ends of the blades of the compressor impeller is required to be reduced as much as possible.
However, when the gap is reduced, for example, contact of the blade with the shroud surface due to vibration, inclination of a rotary shaft of the compressor impeller, and other factors may cause the damage of the compressor impeller. Therefore, as the supercharger compressor housing, there has hitherto been used a compressor housing in which an abradable seal made of a resin material or other materials, which is softer than the blades, is used as a member forming the shroud surface.
There have hitherto been proposed various types of compressor housings using the abradable seal described above. The compressor housings are mainly classified into the following three types in terms of manufacturing processes:
(1) Thermal Spraying Method
A compressor housing including a thermally sprayed layer functioning as the abradable seal, which is formed directly on a compressor housing main body portion by thermal spraying (see, for example, PTL 1);
(2) Insert-Molding Method
A compressor housing including an abradable seal, which is formed directly on a compressor housing main body portion by insert-molding (see, for example, PLT 2); and
(3) Press-Fitting Method
A compressor housing including an abradable seal, which is formed and processed into a predetermined shape in advance and is fixed to an inner peripheral portion of a compressor housing main body portion by press-fitting or other methods (see, for example, PLT 3).
[PTL 1] JP 03-068529 U
[PTL 2] JP 2004-299381 A
[PTL 3] WO 2016-136037 A1
However, when the compressor housing is manufactured by the thermal spraying method or the insert-molding method, an expensive and large-size manufacturing facility such as a thermal spraying apparatus or an injection-molding apparatus is required. Further, when the press-fitting method is employed, the press-fitted abradable seal is deformed due to creeping, with the result that drop or detachment of the abradable seal or other failures are liable to occur.
Meanwhile, as exemplified in Patent Literature 3, an anchor effect can be attained by causing a bulging portion formed on an outer peripheral portion of the abradable seal to bulge into a groove portion having a center axis parallel to a radial direction of the compressor housing main body portion through compression-expansion deformation of the abradable seal. However, even in this case, a bulging amount of the bulging portion (length of the bulging portion located inside the groove portion) cannot be increased by a large amount. The reason is as follows. When the bulging amount is increased so as to attain a higher anchor effect, the press-fitting of the abradable seal into the inner peripheral portion of the compressor housing main body portion becomes difficult. In addition, the abradable seal is deformed or damaged by a pressure applied at the time of press-fitting.
The present invention has been made in view of the circumstances described above, and an object of this invention is to provide a method for manufacturing a supercharger compressor housing, which enables manufacture of a compressor housing including an abradable seal with a simpler manufacturing facility in comparison to a thermal spraying apparatus or an injection-molding apparatus and enables forming of a projecting portion having a larger length in an axial direction of a groove portion by deforming part of the abradable seal between the groove portion formed on a compressor housing main body portion side and the abradable seal. Another object of this invention is to provide a supercharger compressor housing manufactured thereby.
The above-mentioned object is achieved by embodiments of the present invention to be described below. That is:
According to the present invention, provided is a method for manufacturing a supercharger compressor housing, comprising at least: a local heating step for heating a heating target region locally, the heating target region being part of an abradable seal; and a mounting and fixing step for mounting and fixing the abradable seal onto a mounting and fixing surface of a compressor housing main body portion, wherein, in the mounting and fixing step, the heating target region, which has been heated locally, is inserted into a groove portion formed in the mounting and fixing surface while being deformed.
In one embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that the local heating step is carried out through use of an infrared welding machine.
In another embodiment of the method for manufacturing the supercharger compressor housing for according to the present invention, it is preferred that the local heating step is carried out through use of an ultrasonic welding machine.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that the heating target region includes a projecting portion projecting from a main body portion of the abradable seal.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that the groove portion comprises a radial groove portion having a center axis with an angle equal to or larger than −45 degrees and equal to or smaller than 60 degrees with respect to a radial direction of the compressor housing main body portion, and that, in the mounting and fixing step, the heating target region, which has been heated locally, is inserted into the radial groove portion while being deformed.
In still another embodiment of the method for manufacturing the supercharger compressor housing f according to the present invention, it is preferred that the groove portion includes the radial groove portion and an axial groove portion formed at a position in proximity to the radial groove portion and having a center axis with an angle larger than −30 degrees and smaller than 30 degrees with respect to an axial direction of the compressor housing main body portion, and that, in the mounting and fixing step, the single heating target region, which has been heated locally, is inserted into both the radial groove portion and the axial groove portion while being deformed.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that a sealing member arrangement step is carried out to arrange at least one sealing member selected from an O-ring and a sealing material on at least one surface selected from the mounting and fixing surface and a part of the surface of the abradable seal facing to the mounting and fixing surface, before the mounting and fixing step is carried out.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that a fine groove forming step is carried out to form a fine groove by radiating a laser beam onto at least part of an inner wall surface of the groove portion while scanning the laser beam, before the mounting and fixing step is carried out.
According to the present invention, provided is the supercharger compressor housing, including at least: an abradable seal having a ring shape; and a compressor housing main body portion having a ring shape and a mounting and fixing surface as part of an inner wall surface, the abradable seal being mounted and fixed on the mounting and fixing surface, wherein a groove portion is formed in the mounting and fixing surface, and wherein a projecting portion forming a part of the abradable seal, is arranged in the groove portion.
In one embodiment of the supercharger compressor housing according to the present invention, it is preferred that the projecting portion is a thermally deformed projecting portion.
In another embodiment of the supercharger compressor housing according to the present invention, it is preferred that, in an entire interface formed by the mounting and fixing surface and a part of the surface of the abradable seal facing to the mounting and fixing surface, a first interface region is formed by a first region of an inner wall surface of the groove portion, where the first region closely contacts with a surface of the projecting portion, and a second region of the surface of the projecting portion, where the second region closely contacts with the inner surface, in the first interface region, a surface roughness shape of the mounting and fixing surface matches a surface roughness shape of a part of the surface of the abradable seal facing to the mounting and fixing surface, and that in a second interface region obtained by excluding the first interface region from the entire interface, the second interface region includes a portion in which the surface roughness shape of the mounting and fixing surface does not match the surface roughness shape of a part of the surface of the abradable seal facing to the mounting and fixing surface.
In still another embodiment of the supercharger compressor housing according to the present invention, it is preferred that the abradable seal includes a thermally deformed portion and a non-thermally deformed portion.
In still another embodiment of the supercharger compressor housing f according to the present invention, it is preferred that a length L of the projecting portion arranged in the groove portion is equal to or larger than 0.15 mm.
In still another embodiment of the supercharger compressor housing according to the present invention, it is preferred that a distal end of the projecting portion and a bottom of the groove portion be separated from each other, and that a surface of the distal end has a surface texture different from that of a portion of the surface of the abradable seal facing the mounting and fixing surface excluding the surface of the distal end.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that the groove portion include a radial groove portion having a center axis with an angle equal to or larger than −45 degrees and equal to or smaller than 60 degrees with respect to a radial direction of the compressor housing main body portion.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that the groove portion include the radial groove portion and an axial groove portion, which is formed at a position in proximity to the radial groove portion and has a center axis with an angle larger than −30 degrees and smaller than 30 degrees with respect to an axial direction of the compressor housing main body portion.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that at least one sealing member selected from an O-ring and a sealing material be arranged at an interface between the compressor housing main body portion and the abradable seal.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that the groove portion include a radial groove portion having a center axis with an angle equal to or larger than −45 degrees and equal to or smaller than 45 degrees with respect to the radial direction of the compressor housing, and that at least one sealing member selected from an O-ring and a sealing material be arranged at the interface between the compressor housing main body portion and the abradable seal.
In still another embodiment of the method for manufacturing the supercharger compressor housing according to the present invention, it is preferred that a fine groove be formed in at least part of the inner wall surface of the groove portion.
According to the present invention, it is possible to provide a method for manufacturing a supercharger compressor housing, which enables manufacture of a compressor housing including an abradable seal with a simpler manufacturing facility in comparison to a thermal spraying apparatus or an injection-molding apparatus and enables forming of a projecting portion having a larger length in an axial direction of a groove portion by deforming part of the abradable seal between the groove portion formed on a compressor housing main body portion side and the abradable seal, and it is possible to provide a supercharger compressor housing, which is manufactured by this method.
With a method for manufacturing a supercharger compressor housing (hereinafter sometimes simply referred to as “compressor housing”) according to an embodiment, a supercharger compressor housing is manufactured at least through a local heating step of locally heating a heating target region being part of an abradable seal and a mounting and fixing step of mounting and fixing the abradable seal onto a mounting and fixing surface of a compressor main body portion. In the mounting and fixing step, the heating target region, which has been locally heated, is inserted into a groove portion formed in the mounting and fixing surface while being deformed.
In the local heating step, as a local heating apparatus to be used for local heating of the heating target region being the part of the abradable seal, any apparatus can be used as long as an apparatus can selectively heat only the heating target region being the part of the abradable seal. For example, an apparatus such as an infrared welding machine, which selectively applies thermal energy emitted from a heat source (such as an infrared lamp or an electric heater) onto a portion that is desired to be locally heated to heat the portion or an apparatus such as an ultrasonic welding machine, which selectively focuses vibrational energy on a portion that is desired to be locally heated to generate heat in the portion, can be used. Further, the application of the thermal energy to the portion that is desired to be heated may be direct application through air conduction or radiation or indirect application through a heat transfer member such as an iron plate, which is previously heated by the heat source.
The above-mentioned local heating apparatus are all simple and inexpensive as compared to thermal spraying apparatus and injection-molding apparatus. Therefore, the method for manufacturing a supercharger compressor housing according to this embodiment enables manufacture of the compressor housing with a simpler manufacturing facility as compared to related-art methods for manufacturing a compressor housing using a thermal spraying method and an insert-molding method.
Further, in the mounting and fixing step, the heating target region being locally heated is inserted into the groove portion formed in the mounting and fixing surface while being deformed. Thus, with the method for manufacturing a supercharger compressor housing according to this embodiment, an engaging portion having a larger length in an axial direction of the groove portion can be remarkably easily formed by thermally deforming part (heating target region) of the abradable seal between the groove portion formed on the compressor housing main body portion side and the abradable seal at the time of manufacture, as compared to a related-art method for manufacturing a compressor housing using press-fitting.
For the local heating step and the mounting and fixing step, the mounting and fixing step may be carried out after the local heating step is carried out, or the local heating step and the mounting and fixing step may be substantially simultaneously carried out.
In the drawings referred to below, an X direction and a Y direction are orthogonal to each other. The X direction is a direction parallel to a radial direction of the abradable seal, the compressor housing main body portion, and the compressor housing, whereas the Y direction is a direction parallel to an axial direction of the abradable seal, the compressor housing main body portion, and the compressor housing. A Y1 direction is an intake-air outlet side of the abradable seal, the compressor housing main body portion, and the compressor housing, whereas a Y2 direction is an intake-air inlet side of the abradable seal, the compressor housing main body portion, and the compressor housing. An X1 direction is one radial side (right side in each of the drawings) of the abradable seal and the compressor housing main body portion, whereas an X2 direction is another radial side (left side in each of the drawings) of the abradable seal and the compressor housing main body portion. For a shape and a structure in the embodiment, which are illustrated in the drawings without indication of the X direction and the Y direction, a direction is not limited to a specific direction in terms of a relationship of the X direction and the Y direction.
The reference symbol A1 denotes a center axis or the axial direction of the abradable seal. The reference symbol A2 denotes a center axis or the axial direction of the compressor housing main body portion. The reference symbol D2 denotes the radial direction of the compressor housing main body portion. The reference symbol GA denotes a center axis or an axial direction of the groove portion.
First, as illustrated in
Further, in the abradable seal 10A, as illustrated in
The inner peripheral surface 20 forms part of an inner wall surface (shroud surface) of an intake passage of the compressor housing when the abradable seal 10 is mounted and fixed into the compressor housing main body portion. Further, the surfaces (the end surface 30 and the outer peripheral surface 40 in the example illustrated in
In the local heating step, an infrared welding machine 300 is used. The infrared welding machine 300 includes a casing 310 having a disc-like shape and an infrared lamp 320 having a ring shape, which is arranged inside the casing 310. An opening slit 312 having a ring shape, which is continuous in the circumferential direction, is formed in one surface of the casing 310 so as to correspond to the infrared lamp 320.
For the local heating, the infrared welding machine 300 is arranged on the intake-air inlet side (Y2 direction side) of the abradable seal 10A so that the opening slit 312 of the infrared welding machine 300 and the projecting portion 50 of the abradable seal 10A are facing to each other. Then, under this state, only the projecting portion 50 being a heating target region HT is selectively heated. Heating conditions for the selective heating are suitably selected so that a resin material that forms the projecting portion 50 of the abradable seal 10A is sufficiently softened and the projecting portion 50 becomes easily deformable in the mounting and fixing step.
After completion of the local heating step, the abradable seal 10A is mounted onto the mounting and fixing surface of the compressor housing so as to carry out the mounting and fixing step. At this time, first, as illustrated in
The compressor housing main body portion 100A includes an inlet opening portion 110, which has a ring shape and is formed on the intake-air inlet side, and an outlet opening portion 120 formed on the intake-air outlet side. An inner wall surface 130 that is continuous from the inlet opening portion 110 to the vicinity of a periphery of the outlet opening portion 120 includes a first region 130A being substantially parallel to the center axis A2 and extending from the inlet opening portion 110 toward an intake-air discharge port side, a second region 130B being substantially flush with an opening surface of the outlet opening portion 120 and surrounding a periphery of the outlet opening portion 120, and a third region 130C being a boundary portion between the first region 130A and the second region 130B and being positioned in the vicinity of the outlet opening portion 120. In the compressor housing main body portion 100A exemplified in
The mounting and fixing surface 140 includes a first surface 140A extending radially outward from a boundary portion between the first region 130A and the third region 130C, a second surface 140B extending from an outer peripheral end side of the first surface 140A to the Y1 direction side, a third surface 140C extending radially outward from an end of the second surface 140B on the Y1 direction side, a fourth surface 140D extending from a boundary portion between the second region 130B and the third region 130C in the Y2 direction, and a groove portion 142 being formed at a boundary portion between the third surface 140C and the fourth surface 140D and having a groove bottom projecting toward a radially outer side. The groove portion 142 is formed continuously in the circumferential direction.
In the mounting and fixing step, first, as illustrated in
In the example illustrated in
Next, the abradable seal 10A under the state illustrated in
The mounting and fixing step may be carried out under a reduced-pressure environment. Further, in order to improve productivity, forcible cooling may be carried out with a blow of an air at an ambient temperature or a cooled air, or other methods substantially simultaneously with the end of deformation of the heating target region HT.
The inner peripheral surface 20 of the abradable seal 10A that is mounted and fixed into the compressor housing main body portion 100 forms an inner wall surface 220 of the compressor housing 200 together with the first region 130A and the second region 130B, which form the inner wall surface 130 of the compressor housing main body portion 100. When a supercharger is assembled using the compressor housing 200, distal ends of blades of a compressor impellor are positioned in proximity to the inner wall surface 20 of the abradable seal 10.
First, as illustrated in
Then, under the state illustrated in
Next, the abradable seal 10A with the projecting portion 50 (heating target region HT) being easily deformable is further inserted toward the compressor housing main body portion 10A side while the pressure is being applied thereto. At this time, the projecting portion 50 (heating target region HT) of the abradable seal 10A, which has been made easily deformable by the local heating through the application of the ultrasonic wave, is pressed hard against the third surface 140C of the mounting and fixing surface 140 to be deformed so as to expand to both radial sides. As a result, the gaps G formed between the mounted and fixed surface 60 and the mounting and fixing surface 140 are eliminated. At the same time, part of the deformed projecting portion 50 (heating target region HT) penetrates into the groove portion 142 to form the engaging portion 210 at which the projecting portion 50 is engaged with the groove portion 142. In this manner, the compressor housing 200A illustrated in
In the method for manufacturing a compressor housing according to this embodiment, which involves use of the ultrasonic welding machine, the local heating step and the mounting and fixing step are carried out substantially simultaneously. The local heating step and the mounting and fixing step may be carried out under a reduced-pressure environment. Further, in order to improve productivity, the forcible cooling may be carried out with a blow of an air at an ambient temperature or a cooled air, or other methods substantially simultaneously with the end of deformation of the heating target region HT.
The heating target region HT can be suitably selected in accordance with a combination of the shape of the mounted and fixed surface 60 of the abradable seal 10 and the shape of the mounting and fixing surface 140 of the compressor housing main body portion 100 as long as the heating target region HT is a portion including a region of the mounted and fixed surface 60 of the abradable seal 10. Therefore, the heating target region HT is not limited to the projecting portion having the distal end with a sharply and narrowly pointed shape on the XY cross section as exemplified in
When the local heating is carried out through conversion of the vibrational energy into thermal energy as in the case of the ultrasonic welding machine or other machines, it is preferred that the heating target region HT formed on the mounted and fixed surface 60 of the abradable seal 10 be selected from the projecting portion and the angular portion. It is more preferred that the projecting portion be selected, and is further preferred that the projecting portion including the distal end having a sharply pointed shape be selected. This is because the vibrational energy can be more easily selectively focused on the vicinity of the heating target region HT when the heating target region HT has the narrowly pointed shape.
The heating target region HT may be a continuous region or a non-continuous (discrete) region in the circumferential direction. The continuous region or the discrete region in the circumferential direction can be suitably selected as the heating target region HT in accordance with a kind of a local heating apparatus to be used and a circumferential position of forming of the groove portion 142 formed in the compressor housing main body portion 100. In terms of the local heating apparatus to be used, (1) when the infrared welding machine is used, the heating target region HT can be selected based on a shape and a structure of the infrared welding machine, and (2) when the ultrasonic welding machine is used, the heating target region HT can be selected based on a shape and a structure of the abradable seal 10. For example, when the infrared welding machine 300 illustrated in
As described above, with the method for manufacturing a compressor housing according to this embodiment, the compressor housing 200A as exemplified in
The projecting portion 70 is also a thermally deformed projecting portion DFP that forms a thermally deformed portion DF formed by thermal deformation of the heating target region HT. In the manufacture example illustrated in
The thermally deformed portion DF of the abradable seal 10 in a state of being mounted and fixed to the compressor housing main body portion 100 is a portion formed by plastic fluidization and subsequent cooling and solidification of the resin material that forms the abradable seal 10 at the time of mounting and fixation. Therefore, there is formed a portion in which a surface of the thermally deformed portion DF and the mounting and fixing surface 140 are held in close contact with each other without a gap. The reason is as follows. In a process in which the heating target region HT is thermally deformed and then cooled and solidified again, a surface roughness shape of the mounting and fixing surface 140 is thermally transferred onto the surface of the thermally deformed portion DF. Meanwhile, in an interface region INT2a formed between a portion of the mounted and fixed surface 60 of the abradable seal 10 except for the surface of the thermally deformed portion DF and the mounting and fixing surface 140, the above-mentioned transfer of the surface roughness shape does not occur. Therefore, in the interface region INT2a, the surface roughness shape of the mounting and fixing surface 140 and a surface roughness shape of the mounted and fixed surface 60 do not correspond to each other.
Specifically, in the compressor housing 200 according to this embodiment, in an entire interface formed by the mounting and fixing surface 140 and a part of the surface of the abradable seal 10 facing to the mounting and fixing surface 140, a first interface region INT1 is formed by a first region of an inner wall surface of the groove portion 142, where the first region closely contacts with a surface of the projecting portion 70, and a second region of the surface of the projecting portion 70, where the second region closely contacts with the inner surface. In the first interface region INT1, the surface roughness shape of the mounting and fixing surface 140 and the surface roughness shape of the mounted and fixed surface 60 have a relationship of corresponding to each other. More specifically, the relationship in which the surface roughness shapes correspond to each other is a relationship in which surface recesses and projections of one of the surfaces correspond to surface recesses and projections of another surface without a gap by being thermally transferred onto the another surface.
In contrast, a second interface region INT2 obtained by excluding the first interface region INT1 from the entire interface includes a portion (interface region INT2a) in which the surface roughness shape of the mounting and fixing surface 140 does not correspond to the surface roughness shape of the mounted and fixed surface 60.
As described above, in the engaging portion 210 of the compressor housing 200 according to this embodiment, the interface at which the surface of the projecting portion 70 and the inner wall surface of the groove portion 142 are held in close contact with each other is formed. The same substantially similarly applies to a case in which an engaging portion is formed by insert molding. Therefore, as compared to a case in which the projecting portion and the groove portion are simply mechanically engaged with each other, a remarkably large bonding strength can be obtained at the engaging portion 210.
Meanwhile, in a case in which the engaging portion is formed by causing a bulging portion formed on an outer peripheral portion of the abradable seal to bulge into the groove portion by a press-fitting method exemplified in Patent Literature 3, a larger bonding strength can be easily obtained as compared to a case in which the engaging portion formed by causing the bulging portion to bulge is not formed. At the time of press-fitting, however, a pressure is applied to the abradable seal or the vicinity of the bulging portion to generate a residual stress. As a result, creeping inevitably occurs. With the method for manufacturing a compressor housing according to this embodiment, however, the engaging portion 210 is formed by the thermal deformation. Therefore, in comparison to the related-art manufacturing method using the press-fitting, the residual stress is scarcely generated in the main body portion and the projecting portion 70 of the abradable seal 10 at the time of manufacture and after the manufacture of the compressor housing 200 according to this embodiment. Thus, the occurrence of creeping can be prevented.
For reference, with the press-fitting method exemplified in Patent Literature 3, a surface of the bulging portion and the mounting and fixing surface are firmly held in close contact with each other at an interface therebetween. However, the interface portion is simply formed only by mechanical press-fitting. Therefore, as compared to a case in which the resin material that forms the heating target region HT is softened by heating and is firmly brought into close contact with the inner wall surface of the groove portion 142, there is a tendency that an extremely small gap is formed at the interface or fine wrinkles, cracks, and other defects due to a mechanical strain in the vicinity of the surface of the bulging portion is formed by the pressure applied at the time of press-fitting. Further, with the thermal spraying method or the insert-molding method, the mounting and fixing surface and the mounted and fixed surface are held in close contact with each other over the entire interface. Specifically, the above-mentioned interface structure is peculiar to the compressor housing 200 according to this embodiment, and is not found in the related-art compressor housings. Further, in the compressor housing 200 according to this embodiment, the abradable seal 10 includes the thermally deformed portion DF formed by the thermal deformation at the time of manufacture and the portion (non-thermally deformed portion) other than the thermally deformed portion DF. Such a structure is also peculiar, and is not found in the related-art compressor housings manufactured by the thermal spraying method, the insert-molding method, or the press-fitting method.
Next, other variations of the structure of the vicinity of the engaging portion 210 are described.
A groove portion 142D (142) illustrated in
The engaging portion 210 formed by the radial groove portion 142D and the projecting portion 70 (thermally deformed projecting portion DFP) arranged in the radial groove portion 142D can effectively prevent drop or detachment of the abradable seal 10 caused by slide of the abradable seal 10 in the Y1 direction. For the manufacture of the compressor housing 200, in terms of further facilitation of deep insertion of the heating target region HT, which has become easily deformable by heating, into the radial groove portion 142D without a gap while deforming the heating target region HT, a lower limit value of the angle α is preferably equal to or larger than 0 degrees, more preferably, equal to or larger than 10 degrees. In terms of further reliable prevention of the drop or the detachment of the abradable seal 10, an upper limit value of the angle α is preferably equal to or smaller than 40 degrees, more preferably, equal to or smaller than 30 degrees.
A groove portion 142A (142) illustrated in
The engaging portion 210 formed by the axial groove portion 142A and the projecting portion 70 (thermally deformed projecting portion DFP) arranged in the axial groove portion 142A can effectively prevent a positional deviation of the abradable seal 10 caused by slide of the abradable seal 10 in the X direction. For the manufacture of the compressor housing 200, in terms of further facilitation of deep insertion of the heating target region HT, which has become easily deformable by heating, into the axial groove portion 142A without a gap while deforming the heating target region HT, the angle β preferably falls within a range of from −10 degrees to 10 degrees, more preferably, is 0 degrees.
The surface of the projecting portion 70 may be held in close contact with the entire inner wall surface of the groove portion 142, as exemplified in
The reason is as follows. First, the abradable seal 10 is generally formed by injection molding. Therefore, the surface of the abradable seal 10 is a smooth surface obtained by transfer of an inner wall surface (generally, a smooth surface) of a die used at the time of injection molding. Meanwhile, when the surface of the abradable seal 10 made of the resin material is simply heated, roughness of the surface of the heated portion increases to such a degree that the roughness is easily visible as compared to roughness before heating. Thus, the smooth surface turns into a rough surface (rough surface having irregularly formed fine surface recesses and projections). For the manufacture of the compressor housing 200, however, the heating target region HT is deformed while being pressed against the mounting and fixing surface 140 generally being the smooth surface. Therefore, a portion of the surface of the thermally deformed portion DF, where the portion is held in close contact with the mounting and fixing surface 140, becomes a smooth surface obtained by the transfer of the mounting and fixing surface 140. However, when there is formed a portion in which the projecting portion 70 that forms the thermally deformed portion DF and the inner wall surface of the groove portion 142, which includes the mounting and fixing surface 140, cannot be held in close contact with each other and are separated from each other as illustrated in
A depth D of the groove portion 142 is not particularly limited. However, in terms of facilitation of the forming of the engaging portion 210 having a large bonding force, the depth D is preferably equal to or larger than 0.3 mm, more preferably, equal to or larger than 0.5 mm, and further preferably, equal to or larger than 1.0 mm. Meanwhile, although an upper limit of the depth D is not particularly limited. Thus, although the upper limit of the depth D may be equal to or smaller than 5.0 mm in terms of processability, the upper limit of the depth D is preferably equal to or smaller than 2.0 mm in practical use because a deep groove is required to be processed. In this case, it is preferred that a length L (length in a direction parallel to the center axis GA) of the projecting portion 70 arranged in the groove portion 142 fall within a range of from 0.5×D to D. When a relationship of length L<depth D is satisfied, the distal end 70T of the projecting portion 70 is separated from the bottom 142BT of the groove portion 142, as exemplified in
Further, with the method for manufacturing a compressor housing according to this embodiment, the projecting portion 70 is formed by thermally deforming the heating target region HT. Therefore, as compared to the case in which the bulging portion is formed by the press-fitting method as exemplified in Patent Literature 3, the length L of the projecting portion 70 can be easily increased to be significantly larger than a bulging length (bulging amount) of the bulging portion. In terms of facilitation of the forming of the engaging portion 210 having a large bonding force, the length L of the projecting portion 70 has a practically impossible value for the bulging amount when the bulging portion is formed by the press-fitting method as exemplified in Patent Literature 3, specifically, is preferably equal to or larger than 0.15 mm, more preferably, equal to or larger than 0.25 mm. An upper limit value of the length L is only required to be equal to or smaller than the depth D.
Next, another example of the method for manufacturing a compressor housing and the compressor housing manufactured by the method according to this embodiment are further described.
In an abradable seal 10B (10) to be used for the manufacture of a compressor housing 200B (200) illustrated in
Meanwhile, in a compressor housing main body portion 100B (100) to be used for the manufacture of the compressor housing 200B, a total of three groove portions 142 including two radial groove portions 142D (142) and one axial groove portion 142A (142) is formed in the mounting and fixing surface 140. One radial groove portion 142D (radial groove portion 142D on the outlet side) of the two radial groove portions 142 is formed on the Y1 direction side, whereas another radial groove portion 142D (radial groove portion 142D on the inlet side) is formed on the Y2 direction side. The axial groove portion 142A is formed at a position in proximity to the radial groove portion 142D on the outlet side.
Under a state immediately before the welding, the projecting portion 50 on the outlet side is positioned so as to face to the radial groove portion 142D on the outlet side and the axial groove portion 142A, whereas the projecting portion 50 on the inlet side is positioned so as to face to the projecting portion 50 on the inlet side, as illustrated in
The projecting portion 70 arranged in the radial groove portion 142D is sometimes referred to as “radial projecting portion 70D”, and the projecting portion 70 arranged in the axial groove portion 142A is sometimes referred to as “axial projecting portion 70A”. When the number of the heating target regions HT, the number of groove portions 142, the number of projecting portions 70 (thermally deformed projecting portions DFP), and the number of engaging portions 210 are counted, a region or a portion which is present at each different position on a plane that is parallel to both the axial direction A2 and the radial direction D2 of the compressor housing main body portion 100 and a plane (XY plane) that is parallel to both the axial direction A1 and the radial direction of the abradable seal 10 is counted as one region or portion. Therefore, regardless of whether the heating target region HT, the groove portion 142, the projecting portion 70 (thermally deformed projecting portion DFP), or the engaging portion 210, which is present at one position, is formed continuously or non-continuously (discretely) in the circumferential direction on the XY plane, the above-mentioned region or portion is counted as one region or portion.
In an abradable seal 10C (10) to be used for the manufacture of a compressor housing 200C (200) illustrated in
Meanwhile, in a compressor housing main body portion 100C (100) to be used for the manufacture of the compressor housing 200C, a total of two groove portions 142 including one radial groove portion 142D (142) and one axial groove portion 142A (142) is formed in the mounting and fixing surface 140. The axial groove portion 142A is formed at a position in proximity to the radial groove portion 142D. On the Y2 direction side of those two groove portions 142, an auxiliary groove portion 144 is further formed.
Under the state immediately before the welding, as illustrated in
In an abradable seal 10D (10) to be used for manufacture of a compressor housing 200D (200) illustrated in
Meanwhile, in a compressor housing main body portion 100D (100) to be used for the manufacture of the compressor housing 200D, one radial groove portion 142D (142) is formed in the mounting and fixing surface 140. Further, the auxiliary groove portion 144 is formed on the Y2 direction side of the radial groove portion 142D.
Under the state immediately before the welding, the angular portion 52 is positioned so as to face to the radial groove portion 142D, as illustrated in
For the manufacture of the compressor housing 200D, the angular portion 52 being the heating target region HT is inserted into the radial groove portion 142D while being thermally deformed. At this time, the angular portion 52 is thermally deformed to penetrate into the radial groove portion 142D. At the same time, the O-ring 400 is sandwiched between the groove portion 80 formed in the mounted and fixed surface 60 and the mounting and fixing surface 140 facing to the groove portion 80, while the auxiliary projecting portion 82 is arranged in the auxiliary groove portion 144 to be engaged therewith.
In this manner, the projecting portion 70 (thermally deformed projecting portion DFP), which is newly formed by the thermal deformation, is arranged in the radial groove portion 142D. As a result, the compressor housing 200D including the single engaging portion 210 is obtained. The compressor housing 200D further includes an auxiliary engaging portion (auxiliary engaging portion 212) including the auxiliary projecting portion 82 formed by the simple insertion without using the thermal deformation and the auxiliary groove portion 144.
In an abradable seal 10E (10) to be used for manufacture of a compressor housing 200E (200) illustrated in
Meanwhile, in a compressor housing main body portion 100E (100) to be used for the manufacture of the compressor housing 200E, a total of two groove portions 142 including one radial groove portion 142D (142) and one axial groove portion 142A (142) is formed in the mounting and fixing surface 140. The axial groove portion 142A is formed at a position in proximity to the radial groove portion 142D. On the Y2 direction side of those two groove portions 142, the auxiliary groove portion 144 is further formed.
Under the state immediately before the welding, as illustrated in
In an abradable seal 10F (10) to be used for manufacture of a compressor housing 200F (200) illustrated in
Meanwhile, in a compressor housing main body portion 100F (100) to be used for the manufacture of the compressor housing 200F, a total of two groove portions 142 including one radial groove portion 142D (142) and one axial groove portion 142A (142) is formed in the mounting and fixing surface 140. The axial groove portion 142A is formed at a position in proximity to the radial groove portion 142D. On the Y2 direction side of those two groove portions 142, a corner portion 150 is further formed.
Under the state immediately before the welding, the elevated portion 54 is positioned so as to face to the radial groove portion 142D and the axial groove portion 142A, whereas the tapered portion 84 is positioned so as to face to the corner portion 150, as illustrated in
Although the compressor housing main body portion 100 to be used for the method for manufacturing a compressor housing according to this embodiment is only required to include one or more groove portion 142 formed in the mounting and fixing surface 140, it is particularly preferred that the radial groove portion 142D be included as the groove portion 142. In this case, in the mounting and fixing step, the locally heated heating target region HT is inserted into the radial groove portion 142D while being deformed. In this manner, the engaging portion 210 including the radial projecting portion 70D arranged in the radial groove portion 142D can be formed.
In the compressor housing 200 including the engaging portion 210 with the center axis GA of the groove portion 142 described above being oriented in the radial direction D2 of the compressor housing main body portion 100, the drop or the detachment of the abradable seal 10 mounted and fixed into the compressor housing main body portion 100 can be prevented. Therefore, a fixing member such as a C-ring, a pin, or a screw is not required to be used for the purpose of prevention of the drop or the detachment of the abradable seal 10. Further, in comparison to a case in which the engaging portion with the center axis of the groove portion being oriented in the radial direction is formed by the press-fitting method exemplified in Patent Literature 3 and other literatures, the engaging portion 210 formed by arranging the radial projecting portion 70D in the radial groove portion 142D allows easy forming of the radial projecting portion 70D having the larger length L in the axial direction GA of the radial groove portion 142D. Thus, an anchor effect produced at the engaging portion 210 can be increased. As a result, an extremely excellent effect of preventing the drop and the detachment of the abradable seal 10 can be obtained.
In order to further improve the effect of preventing the drop and the detachment of the abradable seal 10, two or more radial groove portions 142D may be formed in the mounting and fixing surface 140, as exemplified in
The axial groove portion 142A may be included as the groove portion 142. In this case, in the mounting and fixing step, the engaging portion 210 including the axial projecting portion 70A arranged in the axial groove portion 142A can be formed by inserting the locally heated heating target region HT into the axial groove portion 142A while deforming the heating target region HT. In the compressor housing 200 including the engaging portion 210 with the center axis GA of the groove portion 142 being oriented in the axial direction as described above, a positional deviation of the abradable seal 10 mounted and fixed into the compressor housing main body portion 100 in the radial direction can be suppressed.
It is further preferred that the radial groove portion 142D and the axial groove portion 142A formed at a position in proximity to the radial groove portion 142D be included as the groove portions 142. In this case, as exemplified in
The groove portion 142 formed in the mounting and fixing surface 140 may be the radial groove portion 142D alone. In this case, as exemplified in
Further, with the method for manufacturing a compressor housing according to this embodiment, as exemplified in
The compressor housing 200 having a structure in which another member such as the O-ring 400 or the sealing material (sealant) 410 is arranged at the interface between the compressor housing main body portion 100 and the abradable seal 10 cannot be manufactured by the insert-molding method and the thermal spraying method. The reason is as follows. At the time of insert-molding, when a resin in a molten state is injected to fill a space surrounded by a die for molding the abradable seal and the compressor housing main body portion, the another member such as the O-ring or the sealing material (sealant), which is arranged on the mounting and fixing surface of the compressor housing main body portion, is easily moved away. With the thermal spraying method, the O-ring or the sealing material (sealant) is, for example, thermally decomposed.
Meanwhile, although the engaging portion (engaging portion including the groove portion having the center axis oriented in the axial direction of the compressor housing main body portion) having a high effect of preventing the positional deviation of the abradable seal can be easily formed by the press-fitting method, it is in principle impossible or extremely difficult to form the engaging portion having the high effect of preventing the drop or the detachment of the abradable seal (engaging portion including the groove portion having the center axis oriented in the radial direction of the compressor housing main body portion). Even by the press-fitting method, the engaging portion having the function of preventing the drop and the detachment of the abradable seal can be formed by arranging part (bulging portion) of the abradable seal in the groove portion extending in the radial direction by the compression-expansion deformation, as exemplified in Patent Literature 3. Because of the use of the compression-expansion deformation, however, the bulging amount of the bulging portion is extremely limited. Therefore, the compressor housing disclosed in Patent Literature 3 is significantly inferior to the compressor housing including the engaging portion 210 formed by the combination of the radial groove portion 142D and the radial projecting portion 70D according to this embodiment in terms of the effect of preventing the drop and the detachment of the abradable seal.
Specifically, the compressor housing 200 including the engaging portion 210 having the radial groove portion 142D and the radial projecting portion 70D (thermally deformed projecting portion DFP) arranged in the radial groove portion 142D, and including at least one sealing member selected from the O-ring and the sealing material (sealant) arranged at the interface between the compressor housing main body portion 100 and the abradable seal, cannot be substantially manufactured by the related-art methods for manufacturing a compressor housing. As the compressor housing 200 having the above-mentioned structure, the compressor housings 200C, 200D, 200E, and 200F respectively illustrated in
For the manufacture of the compressor housing 200 according to this embodiment, a fixing member such as a pin or a member for the purpose of prevention of gas leakage, such as the O-ring, is not required to be used. Specifically, the compressor housing 20 may include only the compressor housing main body portion 100 and the abradable seal 10. In this case, the number of components used for the manufacture of the compressor housing 200 can be reduced. Hence, the structure can be simplified, and productivity can be further improved at the same time.
Further, with the method for manufacturing a compressor housing according to this embodiment, a fine groove forming step of forming a fine groove by radiating a laser beam onto at least part of the inner wall surface of the groove portion 142 while scanning the laser beam may be carried out before the mounting and fixing step is carried out. In this case, when the heating target region HT, which has been softened by heating, penetrates into the groove portion 142, also the fine groove formed by laser process is filled, without a gap, with the resin material that forms the heating target region HT. Therefore, a more excellent sealing function can be obtained. In addition, the sealing member such as the O-ring 400 is not required to be used to ensure the sealing function. The fine groove formed by the laser processing is formed by scanning the laser beam in a given regular pattern. Therefore, the surface of the inner wall surface of the groove portion 142 has regularly formed surface recesses and projections. Further, the fine groove formed in the fine groove forming step is formed by the injection molding, casting, cutting work, or other processing. A depth LD of the fine groove is only required to be relatively remarkably smaller than the depth D of the groove portion 142. For example, LD/D is preferably equal to or smaller than 0.1, more preferably, equal to or smaller than 0.05. Further, an absolute value of the depth LD of the fine groove can be suitably selected from a range in which LD/D falls within the above-mentioned range, for example, within a range of from about 10 μm to about 500 μm.
The engaging portion 210, and the groove portion 142 and the projecting portion 70 that form the engaging portion 210 may be formed continuously in the circumferential direction, but may also be formed non-continuously (discretely) in the circumferential direction. In the latter case, the abradable seal 10 can be prevented from rotating in the circumferential direction with respect to the compressor housing main body portion 100. This point applies to the auxiliary engaging portion 212, and the auxiliary projecting portion 82 and the auxiliary groove portion 144 that form the auxiliary engaging portion 212.
As a material for forming the abradable seal 10, a resin material containing a resin as a main component is used. The resin material may contain the resin alone. In general, however, it is preferred that the resin material contain the resin and a filler such as graphite. As the resin, any known resin may be used. It is preferred that the resin have an adequate heat resistance. In view of the heat resistance, for example, a thermoplastic polyimide resin may be exemplified. Further, for crystallinity and non-crystallinity of the resin, it is preferred that the resin be amorphous in view of a reduction in thermal expansion coefficient. When the filler is used, a compounding ratio of the filler is not particularly limited. For example, the compounding ratio can be set to fall within a range of from about 30% by mass to about 40% by mass to a total amount of the resin material. A composition of the resin material (kind and compounding ratio of each component) can be suitably selected in accordance with a material that forms the compressor housing main body portion 100 to be used in combination with the abradable seal 10 so as to obtain desired various property values or characteristics.
As a material for forming the compressor housing main body portion 100, a known material that is used as the material for forming the compressor housing main body portion 100 can be suitably used. For example, an aluminum alloy, a magnesium alloy, a phenol resin, a polyphenylene sulfide (PPS) resin are given.
The compressor housing main body portion 100A forming the compressor housing 200 according to this embodiment, which is illustrated in
For example, in the compressor housing main body portion 100, the core portion 500 and the scroll forming portion 520 may be different members. In this case, the compressor housing 200 can be manufactured through use of the compressor housing main body portion 100 including the core portion 500 and the inlet-side cylindrical portion 510, which are formed integrally with each other, and the abradable seal 10. When a supercharger is assembled with the compressor housing 200, the scroll forming portion 520 manufactured as a separate member from the compressor housing main body portion 100 including the core portion 500 and the inlet-side cylindrical portion 510, which are formed integrally with each other, can be mounted and fixed to the outer peripheral side of the core portion 500.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/020094 | 5/30/2017 | WO | 00 |