JP2016223404A - Compressor housing for supercharger and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor housing for a supercharger and a method of manufacturing the same, which can reduce the number of components and costs.SOLUTION: A compressor housing 1 for a supercharger has a housing body 20 configured to house an impeller 10 and formed with an inner peripheral recess 21 which is annular along the outer periphery of the impeller 10 and is concave in the inner peripheral surface, and an annular slide member 30 which is disposed in the inner peripheral recess 21 and has the inner peripheral surface forming a shroud surface 31 opposed to the impeller 10. The housing body 20 has a diffuser surface 24 which is formed to continue to the shroud surface 31 on the outer peripheral side of the shroud surface 31. At the boundary 101 between the outer peripheral end of the slide member 30 and the inner peripheral end of the diffuser surface 24 of the housing body 20, a junction 4 is formed, at which the housing body 20 and the slide member 30 are joined by friction stir welding.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a compressor housing for a supercharger and a method for manufacturing the same.

  A compressor (compressor) used in a turbocharger of an automobile turbocharger is configured to be able to accommodate an impeller, and is formed in the circumferential direction on the outer peripheral side of the impeller, and an intake port that sucks air toward the impeller And a compressor housing having a scroll chamber for introducing the air discharged from the impeller and a shroud surface facing the impeller.

In the compressor having the above-described configuration, the compression efficiency of the compressor can be increased by making the gap between the impeller blade and the shroud surface of the compressor housing as small as possible.
However, if this gap is reduced, the impeller may be damaged when the blades of the impeller come into contact with the shroud surface of the compressor housing, for example, due to vibration or vibration of the impeller rotation shaft.

Therefore, a structure in which a sliding member made of a resin softer than an impeller blade is attached to a portion of the compressor housing that forms the shroud surface has been proposed (Patent Document 1).
According to this, even if the blade of the impeller contacts the shroud surface of the compressor housing due to vibration or the swing of the impeller rotating shaft, the sliding member attached to the portion that forms the shroud surface is only scraped. Without any breakage, the clearance between the impeller blades and the shroud surface of the compressor housing remains small.

JP-A-9-170442

  However, in the said patent document 1, in order to fix a sliding member to a shroud part, the sliding member is expanded to the diffuser part which does not oppose an impeller. The sliding member is fastened and fixed to the main body (housing main body) of the compressor housing by a screw member through a screw insertion hole provided in the enlarged portion. For this reason, the sliding member is increased in size by enlarging the portion. Since the sliding member generally needs to use a material that is more expensive than the housing body, the cost of the entire compressor housing increases with an increase in the size of the sliding member.

  In addition, when the screw member is used as in the configuration of Patent Document 1, not only the number of parts is increased, but also the screw hole processing formed in the housing body and the screw insertion hole formed in the sliding member are required. . Also from this viewpoint, the manufacturing cost tends to be high.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a compressor housing for a supercharger and a method for manufacturing the same, which can reduce the number of parts and the cost.

One aspect of the present invention is configured to be capable of accommodating an impeller, and has a housing body in which a concave inner peripheral recess is formed on an inner peripheral surface forming an annular shape along the outer periphery of the impeller;
An annular sliding member which is disposed in the inner circumferential recess and whose inner circumferential surface forms a shroud surface facing the impeller;
The housing body has a diffuser surface formed to be continuous with the shroud surface on the outer peripheral side of the shroud surface,
At the boundary portion between the outer peripheral end portion of the sliding member and the inner peripheral end portion of the diffuser surface of the housing body, a joint portion is formed by joining the housing body and the sliding member by friction stir welding. It is in the compressor housing for superchargers characterized by this.

Another aspect of the present invention is a method of manufacturing a compressor housing for the supercharger,
An assembling step of assembling the sliding member into the inner peripheral recess of the housing body;
Next, by performing friction stir welding at the boundary between the outer peripheral end of the sliding member and the inner peripheral end of the diffuser surface of the housing body, a friction stir welding step for forming the joint,
Next, by cutting the sliding member and the housing body, a cutting process for forming the shroud surface and the diffuser surface is performed.
In the cutting process, together with the formation of the shroud surface and the diffuser surface, the surface of the joint is cut so that the surface is smoothly continuous with the diffuser surface and the shroud surface. It is in the manufacturing method of the compressor housing for superchargers.

In the compressor housing for the supercharger, the joint is formed at the boundary between the outer peripheral end of the sliding member and the inner peripheral end of the diffuser surface of the housing body. That is, the housing body and the sliding member are joined by friction stir welding. Therefore, it is not necessary to provide the sliding member with a portion for engaging a fixing member such as a screw member, and the sliding member can be downsized. That is, the cost can be reduced by downsizing the sliding member that tends to have a relatively high material cost.
Further, by using friction stir welding, there is no need for a fixing member for fixing the housing body and the sliding member, so that the number of parts can be reduced.

  As described above, according to the present invention, it is possible to provide a compressor housing for a supercharger and a method for manufacturing the same, which can reduce the number of parts and the cost.

FIG. 5 is a cross-sectional view of a turbocharger including a compressor housing for a supercharger in Embodiment 1, and is a cross-sectional view corresponding to a cross-section taken along the line I-I in FIG. 4. FIG. 2 is an enlarged cross-sectional view in the vicinity of the shroud surface of the compressor housing in the first embodiment, and is a partial enlarged cross-sectional view of FIG. 1. FIG. 5 is an enlarged cross-sectional view in the vicinity of the shroud surface of the compressor housing in the first embodiment, corresponding to the cross-section taken along the line III-III in FIG. 4. FIG. 3 is a plan view of a part of the compressor housing as viewed from the diffuser surface side in the first embodiment. FIG. 3 is an enlarged plan view of a joint portion viewed from the diffuser surface side in the first embodiment. Sectional explanatory drawing of the state just before the assembly | attachment of the housing main body and a sliding member in Embodiment 1. FIG. Sectional explanatory drawing of the sub assembly which assembled | attached the housing main body and the sliding member in Embodiment 1. FIG. The expanded sectional view of the boundary part in Embodiment 1, and explanatory drawing of a rotation tool. The expanded sectional view showing the state immediately after the friction stir welding process in Embodiment 1.

(Embodiment 1)
A compressor housing for a supercharger and a manufacturing method thereof will be described with reference to FIGS.
As shown in FIG. 1, the compressor housing 1 for a supercharger according to this embodiment includes a housing body 20 and a sliding member 30.

The housing main body 20 is configured to be able to accommodate the impeller 10, and a concave inner peripheral recess 21 is formed on the inner peripheral surface forming an annular shape along the outer periphery of the impeller 10.
The sliding member 30 is an annular member that is disposed in the inner peripheral recess 21 of the housing main body 20 and that has an inner peripheral surface that forms a shroud surface 31 that faces the impeller 10.

The housing body 20 has a diffuser surface 24 formed to be continuous with the shroud surface 31 on the outer peripheral side of the shroud surface 31.
As shown in FIGS. 1, 2, 4, and 5, the housing body 20 is connected to the boundary 101 between the outer peripheral end of the sliding member 30 and the inner peripheral end of the diffuser surface 24 of the housing main body 20 by friction stir welding. And the sliding member 30 are joined to each other. The friction stir welding will be described later.

As shown in FIG. 1, the compressor housing 1 forms an outer shell of a compressor (compressor) used in a turbocharger (supercharger) of an automobile.
The housing body 20 is made of, for example, an aluminum gravity cast product, and includes an intake port 11, an intake passage 12, and a scroll chamber 13, as shown in FIG.
The intake port 11 and the intake passage 12 are formed by a cylindrical portion 23 having a cylindrical shape. The scroll chamber 13 is formed in the circumferential direction on the outer peripheral side of the impeller 10 and is configured to introduce the air discharged from the impeller 10.

  The inner peripheral recess 21 is formed along the outer periphery of the sliding member 30 on the inner peripheral surface of the housing body 20. And the inner periphery recessed part 21 is along the cylindrical 1st recessed part 210 formed concavely along the cylindrical sliding member main-body part 310 in the below-mentioned sliding member 30, and the enlarged diameter part 311 in the sliding member 30. And a cylindrical second concave portion 220 formed in a concave shape from the first concave portion 210 to the outer peripheral side. Thereby, the inner periphery recessed part 21 is comprised so that the sliding member 30 can be arrange | positioned.

  The sliding member 30 can be formed of a member that has thermoplasticity and is elastically deformable. For example, the sliding member 30 is made of a thermoplastic polyimide resin. An example of the thermoplastic polyimide resin is Aurum (registered trademark) manufactured by Mitsui Chemicals. The material for forming the sliding member 30 is not limited to this, and, for example, a Bespel (registered trademark) TP series manufactured by DuPont may be employed.

  As shown in FIG. 4, the sliding member 30 has an annular shape, and the entire inner peripheral surface thereof forms a shroud surface 31 facing the impeller 10 (FIG. 1). Further, as shown in FIGS. 1 to 3, the sliding member 30 is formed to have a cylindrical sliding member main body portion 310 and the diameter of the sliding member main body portion 310 is increased radially outward on the opposite side of the air inlet 11 in the sliding member main body portion 310. And an enlarged diameter portion 311. The enlarged diameter portion 311 is formed over the entire circumference of the sliding member 30. The sliding member 30 is disposed in the inner circumferential recess 21 with the sliding member main body 310 positioned in the first recess 210 in the inner circumferential recess 21 and the diameter-enlarged portion 311 positioned in the second recess 220.

  The sliding member 30 is press-fitted into the inner peripheral recess 21 in a state where the outer peripheral surface of the enlarged diameter portion 311 is in pressure contact with the inner peripheral surface of the second recess 220. Further, the outer diameter of the sliding member main body 310 is smaller than the inner diameter of the first recess 210, and the outer peripheral surface of the sliding member main body 310 is not in contact with the inner peripheral surface of the first recess 210.

  As shown in FIG. 4, when the compressor housing 1 is viewed from the diffuser surface 24 side in the axial direction X, the boundary portion 101 between the housing body 20 and the sliding member 30, that is, the boundary portion 101 between the diffuser surface 24 and the shroud surface 31 is It is formed in a circular shape. The joint portion 4 is formed at a part of the boundary portion 101. As shown in FIGS. 2 and 5, the center of the joint portion 4 is located on the outer peripheral side with respect to the boundary portion 101. Here, the center of the joint 4 means the center of the joint 4 in the radial direction of the compressor housing 1. That is, the joint 4 has a dimension b that protrudes to the housing body 20 (the shroud surface 24 side: the outer periphery side) rather than the dimension a that protrudes to the sliding member 30 side (inner periphery side) with reference to the boundary portion 101. Is bigger.

  In the present embodiment, as shown in FIG. 4, the joint portions 4 are formed at four locations on the circular boundary portion 101. The joining parts 4 are arranged at equal intervals. However, the number of the joint portions 4 is not particularly limited. Further, the joint portion 4 may be formed over the entire circumference of the boundary portion 101.

  As shown in FIG. 1, when the turbocharger is configured using the compressor housing 1, the bearing housing of the impeller 10 or the end surface 70 of the back plate is located on the opposite side of the housing body 20 from the intake port 11. A diffuser portion 14 serving as a fluid passage leading from the impeller 10 side to the sucrose chamber 12 is formed between the end surface 70 and the diffuser surface 24 of the housing body 20.

  As shown in FIG. 1, the impeller 10 is disposed on the inner peripheral surface (the shroud surface 31) side of the sliding member 30 of the housing body 20, and is attached so as to be rotatable about the rotation shaft 15. Further, the impeller 10 includes a hub 16 and a plurality of blades 17 that protrude in the circumferential direction from the outer peripheral surface thereof. The plurality of blades 17 are arranged to face the shroud surface 31 of the sliding member 30.

  In the compressor including the compressor housing 1 for the supercharger of the present embodiment, as shown in FIG. 1, the air sucked from the intake port 11 through the intake passage 12 by the rotation of the impeller 10 is caused by the blade 17 of the impeller 10. Accelerated and sent to the diffuser section 14. Then, the air is pressurized in the diffuser unit 14 and sent into the scroll chamber 13.

Next, the manufacturing method of the compressor housing 1 of this embodiment is demonstrated.
As shown in FIGS. 6 and 7, the present manufacturing method performs an assembling process for assembling the sliding member 30 to the inner peripheral recess 21 of the housing body 20, a friction stir welding process described below, and a cutting process.
In the friction stir welding step, as shown in FIGS. 8 and 9, friction stir welding is performed at the boundary portion 101 between the outer peripheral end portion of the sliding member 30 and the inner peripheral end portion of the diffuser surface 24 of the housing body 20. Thereby, the junction part 4 is formed.

In the cutting step, after the friction stir welding step, the sliding member 30 and the housing body 20 are cut to form the shroud surface 31 and the diffuser surface 24 as shown in FIG.
In the cutting process, the shroud surface 31 and the diffuser surface 24 are formed, and the surface of the joint portion 4 is cut so that the surface is smoothly continuous with the diffuser surface 24 and the shroud surface 31.

  In the stage before the cutting step, the sliding member 30 does not have the shroud surface 31 (see FIGS. 1 to 3), and the inner peripheral surface 32 is in the axial direction X as shown in FIGS. The shape is uniformly formed throughout. By inserting the sliding member 30 having such a shape into the inner peripheral recess 21 of the housing body 20 in the assembly step, as shown in FIG. 7, the sub-assembly includes the housing body 20 and the sliding member 30 assembled together. 100 is obtained.

  In the assembling step, the outer peripheral surface of the enlarged diameter portion 311 of the sliding member 30 is in contact with the inner peripheral surface of the second concave portion 220 in the inner peripheral concave portion 21 of the housing body 20, and the inner peripheral concave portion 21. Press fit. That is, the inner peripheral end portion of the diffuser surface 24 of the housing body 20 and the outer peripheral end portion of the sliding member 30 are in contact with each other. This contact portion is the boundary portion 101, and in the friction stir welding step, the joint portion 4 is formed so as to straddle the boundary portion 101.

Friction stir welding (FSW: Friction
Stir Welding) presses the rotating tool 5 that rotates at high speed against the vicinity of the boundary portion 101 (the portion to be processed) between the sliding member 30 and the housing body 20, and moves the rotating tool 5 along the boundary portion 101. The sliding member 30 and the housing body 20 are joined together. As shown in FIG. 8, the rotary tool 5 includes a columnar shoulder portion 51 and a small-diameter columnar probe portion 52 that protrudes from the distal end surface of the shoulder portion 51.

  Then, as shown by the arrow F in FIG. 8, the material of the sliding member 30 and the housing main body 20 (for example, polyimide resin and aluminum alloy) is generated by frictional heat generated when the rotating tool 5 is pressed against the processing target. ), Plastic flow occurs. Specifically, the material of the sliding member 30 and the housing main body 20 is agitated by the probe portion 52 pushed to a predetermined depth in the processing target portion, and flows so as to overflow to the surface. At the same time, the fluidized material of the sliding member 30 and the housing main body 20 is agitated while being pressed by the front end surface of the shoulder portion 51. As a result, the plastically flowed materials are fused and then solidified to form the joint portion 4 that joins the sliding member 30 and the housing body 20 to each other.

Further, in the friction stir welding process, the friction stir welding is performed so that the center of the rotary tool 5 pressed against the portion to be processed is positioned on the outer peripheral side with respect to the boundary portion 101. Thereby, the center of the joint portion 4 can be positioned on the outer peripheral side with respect to the boundary portion 101. That is, before the friction stir welding, the portion that was the housing main body 20 is subjected to friction stirring in a larger range than the portion that was the sliding member 30.
Moreover, as shown in FIG. 9, the surface of the junction part 4 obtained by the friction stir welding process is in a state without smoothness.

  In the cutting step, the subassembly 100 is cut in a region from the inner peripheral surface 32 of the sliding member 30 to the diffuser surface 24 of the housing body 20 to form a shroud surface 31 as shown in FIG. Then, the surface of the joint 4 is cut. And the surface of the junction part 4 is finished in the surface which has the smoothness which followed the diffuser surface 24 and the shroud surface 31. FIG. Thus, as shown in FIG. 1, the compressor housing 1 in which the sliding member 30 is fixed to the housing body 20 is obtained.

Next, the effect of this embodiment is demonstrated.
In the compressor housing 1 for the supercharger, a joint portion 4 is formed at a boundary portion 101 between the outer peripheral end portion of the sliding member 30 and the inner peripheral end portion of the diffuser surface 24 of the housing body 20. That is, the housing body 20 and the sliding member 30 are joined by friction stir welding. Therefore, it is not necessary to provide the sliding member 30 with a portion for engaging a fixing member such as a screw member, and the sliding member 30 can be downsized. That is, the cost can be reduced by downsizing the sliding member 30 that tends to have a relatively high material cost. In the friction stir welding, the sliding member 30 also needs a stirring margin, but the width of the stirring margin can be made sufficiently smaller than the width of the portion for engaging the fixing member.
Further, by using friction stir welding, a fixing member for fixing the housing main body 20 and the sliding member 30 is not necessary, and therefore the number of parts can be reduced.

In addition, as described above, the friction stir welding uses frictional heat between the rotary tool 5 and the portion to be processed, but the required energy is, for example, compared to, for example, nanoporous formation using a laser, small. Therefore, the manufacturing cost can be sufficiently suppressed.
Moreover, since the smoothing of the surface of the junction part 4 can be performed with the formation of the shroud surface 31 and the diffuser surface 24 in the cutting step, the manufacturing cost can be suppressed.

  Further, the center of the joint portion 4 is located on the outer peripheral side with respect to the boundary portion 101. Thereby, the further miniaturization of the sliding member 30 can be achieved. That is, even when performing friction stir welding, since the joint 4 is provided in a part of the sliding member 30, it is necessary to form the joint 4 at a position that does not face the impeller 10. There is. Therefore, a so-called stirring allowance for forming the joint portion 4 is provided at the outer peripheral end portion of the sliding member 30. By reducing the stirring allowance as much as possible, the outer diameter of the sliding member 30 can be made as small as possible. On the other hand, the width of the joint 4 (the dimension of the joint 4 in the radial direction of the compressor housing 1) depends on the diameter of the rotary tool 5, and the diameter of the rotary tool 5 is appropriate if it is not a certain size. It is difficult to perform proper friction stir welding.

  Therefore, the center of the joint 4 is positioned on the outer peripheral side of the boundary portion 101 in order to reduce the stirring margin of the sliding member 30 while ensuring the width of the joint 4. Thereby, the further miniaturization of the sliding member 30 can be achieved, and the compressor housing 1 at a lower cost can be obtained.

  Further, in order to easily realize this, in the friction stir welding process in the above manufacturing method, the friction stir is performed so that the center of the rotary tool 5 pressed against the processing target portion is located on the outer peripheral side with respect to the boundary portion 101. We are joining. In other words, compared with the material of the sliding member 30 (for example, polyimide resin), the portion that was the material of the housing body 20 (for example, aluminum alloy) is frictionally stirred in a larger range, so that the comparison is made. The material cost of the expensive sliding member 30 can be reduced.

  As described above, according to the present embodiment, it is possible to provide a compressor housing for a supercharger and a method for manufacturing the same, which can reduce the number of parts and the cost.

DESCRIPTION OF SYMBOLS 1 Compressor housing for turbochargers 101 Boundary part 20 Housing main body 21 Inner peripheral recessed part 24 Diffuser surface 30 Sliding member 31 Shroud surface 4 Joint part

Claims (4)

A housing main body configured to be capable of accommodating an impeller and having a concave inner peripheral recess formed on an inner peripheral surface forming an annular shape along the outer periphery of the impeller;
An annular sliding member which is disposed in the inner circumferential recess and whose inner circumferential surface forms a shroud surface facing the impeller;
The housing body has a diffuser surface formed to be continuous with the shroud surface on the outer peripheral side of the shroud surface,
At the boundary portion between the outer peripheral end portion of the sliding member and the inner peripheral end portion of the diffuser surface of the housing body, a joint portion is formed by joining the housing body and the sliding member by friction stir welding. Compressor housing for turbochargers.   The supercharger according to claim 1, wherein the joint portion is formed at a part of the boundary portion, and a center of the joint portion is located on an outer peripheral side with respect to the boundary portion. Compressor housing for A method for producing a compressor housing for a supercharger according to claim 1 or 2,
An assembling step of assembling the sliding member into the inner peripheral recess of the housing body;
Next, by performing friction stir welding at the boundary between the outer peripheral end of the sliding member and the inner peripheral end of the diffuser surface of the housing body, a friction stir welding step for forming the joint,
Next, by cutting the sliding member and the housing body, a cutting process for forming the shroud surface and the diffuser surface is performed.
The cutting step includes forming the shroud surface and the diffuser surface and cutting the surface of the joint so that the surface is smoothly continuous with the diffuser surface and the shroud surface. A method of manufacturing a compressor housing for a supercharger.   The friction stir welding is performed in the friction stir welding step so that the center of the rotary tool pressed against the processing target portion is positioned on the outer peripheral side with respect to the boundary portion. A method of manufacturing a compressor housing for a supercharger.

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