阅读说明：本技术 涡轮增压器用压缩机壳体及其制造方法 (Compressor housing for turbocharger and method for manufacturing same ) 是由 矶谷知之 丹羽哲也 大须贺龙 于 2020-03-26 设计创作，主要内容包括：本发明提供一种在降低成本的同时能实现密封性的提高的涡轮增压器用压缩机壳体。涡轮增压器用压缩机壳体(1)被分割为包括涡旋构件(2)和护罩构件(3)的多个构件。涡旋构件(2)和护罩构件(3)通过将设置于护罩构件(3)的压入部(53b)压入设置于涡旋构件(2)的被压入部(53a)而相互组装。进一步地,在设置于涡旋构件(2)和护罩构件(3)中的一方的被压接部(541a、542a)压接设置于涡旋构件(2)和护罩构件(3)中的另一方的压接部(541b、542b)并使压接部(541b、542b)发生塑性流动而形成将两者间密封的密封部(541、542)。(The invention provides a compressor housing for a turbocharger, which can reduce cost and improve sealing performance. A compressor housing (1) for a turbocharger is divided into a plurality of members including a scroll member (2) and a shroud member (3). The scroll member (2) and the shroud member (3) are assembled to each other by press-fitting a press-fitting portion (53b) provided in the shroud member (3) into a press-fitting portion (53a) provided in the scroll member (2). Furthermore, pressure-bonded sections (541a, 542a) provided on one of the scroll member (2) and the shroud member (3) are pressure-bonded to pressure-bonded sections (541b, 542b) provided on the other of the scroll member (2) and the shroud member (3), and the pressure-bonded sections (541b, 542b) are plastically fluidized to form sealing sections (541, 542) that seal between the two.)

1. A compressor housing for a turbocharger, which accommodates a compressor wheel, wherein,

the compressor housing for a turbocharger includes:

an air inlet forming part which forms an air inlet for sucking air towards the compressor impeller;

a shroud portion that circumferentially surrounds the compressor wheel and has a shroud surface that opposes the compressor wheel;

a diffuser portion that is formed on an outer peripheral side of the compressor impeller in a circumferential direction and that forms a diffuser passage through which compressed air discharged from the compressor impeller passes; and

a scroll chamber forming portion which forms a scroll chamber for guiding the compressed air passing through the diffusion passage to the outside,

the compressor housing for a turbocharger is divided into a plurality of members including: a scroll member having at least the suction port forming portion and a part of the scroll chamber forming portion; and a shroud member having at least a part of the scroll chamber forming portion, a part of the diffuser portion, and the shroud portion,

the scroll member and the shroud member are assembled to each other by press-fitting a press-fitting portion provided in the shroud member into a press-fitting portion provided in the scroll member, and a seal portion for sealing between the scroll member and the shroud member is formed by pressure-bonding a pressure-receiving portion provided in one of the scroll member and the shroud member to a pressure-receiving portion provided in the other of the scroll member and the shroud member and causing plastic flow in the pressure-receiving portion.

2. The compressor housing for a turbocharger according to claim 1,

the compressor housing for a turbocharger includes a refrigerant passage formed in a circumferential direction along the diffuser portion and through which a refrigerant that cools the diffuser portion flows,

the refrigerant passage is formed as an annular space formed by a first refrigerant passage forming portion and a second refrigerant passage forming portion formed at portions of the scroll member and the shroud member which face each other,

the sealing portion includes an inner peripheral sealing portion for sealing an inner peripheral side of the refrigerant passage and an outer peripheral sealing portion for sealing an outer peripheral side of the refrigerant passage,

the inner peripheral seal portion is formed by crimping a crimp portion formed at an inner periphery of one of the scroll member and the shroud member to an inner periphery of the other of the scroll member and the shroud member and causing plastic flow of the inner periphery crimp portion,

the outer peripheral seal portion is formed by crimping an outer peripheral crimping portion formed on one of the scroll member and the shroud member to an outer peripheral crimping portion formed on the other of the scroll member and the shroud member by a crimping portion and causing plastic flow of the outer peripheral crimping portion.

3. The compressor housing for a turbocharger according to claim 1 or 2, wherein the seal portion is located on a press-in direction terminal end side of the press-in portion.

4. A method for manufacturing a compressor housing for a turbocharger according to any one of claims 1 to 3,

the manufacturing method comprises the following steps:

a die-casting step of forming the scroll member and the shroud member by die-casting;

a machining step of forming the pressure-receiving portion in one of the scroll member and the shroud member and forming the pressure-bonding portion in the other of the scroll member and the shroud member by machining; and

and an assembling step of press-fitting the press-fitting portion into the press-fitted portion, press-contacting the pressure-bonding section to the pressure-bonded section, and causing plastic flow to form the seal portion, thereby assembling the shroud member to the scroll member.

5. The method of manufacturing a compressor housing for a turbocharger according to claim 4, wherein in the machining step, the pressure-bonding section is machined so as to have a radially protruding mountain shape in a cross section including a rotation shaft of the compressor impeller, and has a starting-end-side inclined surface located on a starting end side in a pressing direction and a terminating-end-side inclined surface located on a terminating end side in the pressing direction, and in the cross section, an angle on an acute angle side of an angle formed by the terminating-end-side inclined surface and the rotation shaft is larger than an angle on an acute angle side of an angle formed by the starting-end-side inclined surface and the rotation shaft.

Technical Field

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

Background

A turbocharger mounted in an internal combustion engine of an automobile or the like has a compressor impeller (impeller) and a turbine impeller (turbine), which are accommodated in a housing. The compressor impeller is disposed in an air flow path formed inside the compressor housing. The air flow path includes an intake port for taking in air toward the compressor impeller, a diffuser passage for passing compressed air discharged from the compressor impeller, and a discharge scroll chamber into which the compressed air having passed through the diffuser passage flows. The discharge scroll chamber discharges compressed air to the engine side.

Further, some internal combustion engines such as automobiles include a blowby gas recirculation device (hereinafter referred to as PCV) that recirculates blowby gas generated in a crankcase to an intake passage to clean the crankcase and a head cover. In this case, oil (oil mist) contained in the blowby gas may flow out from the PCV to the intake passage on the upstream side of the compressor in the turbocharger.

At this time, since the air temperature of the compressor is also increased when the outlet air pressure of the compressor is high, the oil flowing out of the PCV may be condensed and highly viscous due to evaporation to form deposits on the diffuser surface of the compressor housing for the turbocharger, the surface of the bearing housing facing the diffuser surface, and the like, and the deposits may be accumulated. Further, the accumulated deposits narrow the diffusion passage, which may cause a reduction in the performance of the turbocharger and a reduction in the output of the internal combustion engine.

Conventionally, the outlet air temperature of the compressor has been suppressed to some extent in order to prevent the deposition of the deposits in the diffusion passage as described above. Therefore, the performance of the turbocharger cannot be sufficiently exhibited, and the output of the internal combustion engine cannot be sufficiently increased.

Patent document 1 discloses the following structure: in order to prevent deposits from accumulating in the diffuser passage, a refrigerant flow path is provided in the compressor housing for the turbocharger, and a refrigerant is circulated through the refrigerant flow path, thereby suppressing a temperature increase of the compressed air passing through the air flow path in the housing. In the structure disclosed in patent document 1, the compressor housing for the turbocharger is divided into a scroll member (piece) and a shroud member, and the refrigerant passage is defined by assembling the two members.

Disclosure of Invention

Problems to be solved by the invention

In the structure disclosed in patent document 1, the refrigerant flow path prevents the refrigerant from leaking by a seal portion formed by pressing the shroud member into the scroll member. In order to sufficiently improve the sealing performance of the seal portion, it is conceivable to apply a sealing material to the seal portion of the shroud member and the scroll member at the time of press-fitting. However, since a pretreatment such as sealing and degreasing is required for applying the sealing material, the cost is increased and the workability is also poor. On the other hand, in order to reduce the cost and improve the workability, it is conceivable to form the seal portion only on the press-fitting surface of the scroll member by press-fitting the shroud member without using a sealing material, but in this case, a fine gap may be generated in the seal portion to cause leakage of the refrigerant, and a leakage failure may occur. Although the leak failure is detected in the leak inspection after the assembly and does not flow to the market, the yield is reduced, resulting in high cost.

On the other hand, in a compressor housing for a turbocharger which does not have a refrigerant passage, when a scroll member and a shroud member are separately formed and assembled by press-fitting both members, improvement of sealing performance may be required for press-fitting portions of both members. In this case, if the sealing material is used as described above, the cost is high and the workability is deteriorated.

The present invention has been made in view of the above problems, and an object thereof is to provide a compressor housing for a turbocharger, which can improve sealing performance while reducing cost.

Means for solving the problems

One aspect of the present invention relates to a compressor housing for a turbocharger that houses a compressor impeller, the compressor housing for a turbocharger including:

an air inlet forming part which forms an air inlet for sucking air towards the compressor impeller;

a shroud portion that circumferentially surrounds the compressor wheel and has a shroud surface that opposes the compressor wheel;

a diffuser portion that is formed on an outer peripheral side of the compressor impeller in a circumferential direction and that forms a diffuser passage through which compressed air discharged from the compressor impeller passes; and

a scroll chamber forming portion which forms a scroll chamber for guiding the compressed air passing through the diffusion passage to the outside,

the compressor housing for a turbocharger is divided into a plurality of members including: a scroll member having at least the suction port forming portion and a part of the scroll chamber forming portion; and a shroud member having at least a part of the scroll chamber forming portion, a part of the diffuser portion, and the shroud portion,

the scroll member and the shroud member are assembled to each other by press-fitting a press-fitting portion provided in the shroud member into a press-fitting portion provided in the scroll member, and a seal portion for sealing between the scroll member and the shroud member is formed by pressure-bonding a pressure-receiving portion provided in one of the scroll member and the shroud member to a pressure-receiving portion provided in the other of the scroll member and the shroud member and causing plastic flow in the pressure-receiving portion.

Effects of the invention

According to the compressor housing for a turbocharger of the above-described one aspect, the seal portion between the scroll member and the shroud member is formed by pressure-contacting the pressure-contacted portion provided on one of the scroll member and the shroud member to the pressure-contacted portion provided on the other of the scroll member and the shroud member and causing plastic flow of the pressure-contacted portion. Thus, since the pressure-bonding section plastically flows in the seal portion to fill the fine gap, the sealing property can be improved as compared with a case where the seal portion is formed only by press-fitting both. Further, since the coating of a separate sealing material is not required in the sealing portion, cost reduction can be achieved.

As described above, according to the present embodiment, it is possible to provide a compressor housing for a turbocharger that can improve sealing performance while reducing cost.

Drawings

Fig. 1 is a sectional view of a compressor housing for a turbocharger in a first embodiment.

Fig. 2 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in the first embodiment.

FIG. 3 is a cutaway perspective view of the scroll member in the first embodiment.

Fig. 4 is a perspective view of a shroud member in the first embodiment.

Fig. 5 is a cut-away perspective view of a shield member in a first embodiment.

Fig. 6 is an enlarged conceptual view of a main part for explaining a method of manufacturing a compressor housing for a turbocharger in the first embodiment.

Fig. 7 is an enlarged conceptual view of a main part for explaining a method of manufacturing a compressor housing for a turbocharger in the first embodiment.

Fig. 8 is a sectional view of a compressor housing for a turbocharger in a first modification.

Fig. 9 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in the first modification.

Fig. 10 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in the first modification.

Fig. 11 is an enlarged conceptual view of a main part for explaining a method of manufacturing a compressor housing for a turbocharger in the second embodiment.

Fig. 12 is an enlarged conceptual view of a main part for explaining a method of manufacturing a compressor housing for a turbocharger in the second embodiment.

Description of the reference numerals

1: a compressor housing for a turbocharger;

2: a scroll member;

3: a shroud member;

5: a refrigerant flow path;

51: a first refrigerant flow path forming part;

52: a second refrigerant flow path forming part;

53 a: a pressed-in part;

53 b: a press-in part;

541: an inner peripheral seal portion;

541 a: an inner periphery crimped portion;

541 b: an inner circumference crimping part;

542: an outer peripheral seal portion;

542 a: an outer periphery crimped portion;

542 b: an outer periphery crimping part;

545. 547: a starting end side inclined plane;

546. 548: terminal side inclined plane.

Detailed Description

In the present specification, "circumferential direction" refers to a rotation direction of the compressor impeller, "axial direction" refers to a direction of a rotation shaft of the compressor impeller, "radial direction" refers to a radial direction of a virtual circle centered on the rotation shaft of the compressor impeller, and radially outward refers to a direction of a straight line extending from the center of the virtual circle to the circumference.

The compressor housing for a turbocharger includes a refrigerant passage formed in a circumferential direction along the diffuser portion and through which a refrigerant that cools the diffuser portion flows,

the refrigerant passage is formed as an annular space formed by a first refrigerant passage forming portion and a second refrigerant passage forming portion formed at portions of the scroll member and the shroud member which face each other,

the sealing portion includes an inner sealing portion for sealing an inner peripheral side of the refrigerant passage and an outer sealing portion for sealing an outer peripheral side of the refrigerant passage,

the inner peripheral seal portion is formed by pressure-bonding an inner peripheral pressure-bonding portion formed on one of the scroll member and the shroud member to an inner peripheral pressure-bonding portion formed on the other of the scroll member and the shroud member by a pressure-bonding portion and causing plastic flow in the inner peripheral pressure-bonding portion,

the outer peripheral seal portion is formed by a pressure-contact portion formed on one outer periphery of one of the scroll member and the shroud member being pressure-contacted to the other outer periphery pressure-contact portion of the other of the scroll member and the shroud member, and causing plastic flow in the outer periphery pressure-contact portion. According to this configuration, in the compressor housing for a turbocharger provided with the refrigerant passage, the sealing performance of the inner peripheral seal portion and the outer peripheral seal portion of the refrigerant passage can be improved while reducing the cost.

Preferably, the seal portion is located on a terminal side in a press-fitting direction of the press-fitting portion. In this case, when the shield member is assembled to the scroll member, the pressure-bonding section is pressed against the pressure-bonded section after the press-fitting section is press-fitted, and therefore, the dispersion of the plastic flow portion in the seal section can be prevented. This can reliably improve the sealing property.

Another aspect of the present invention is a method for manufacturing a compressor housing for a turbocharger described above, wherein,

the manufacturing method comprises the following steps:

a die-casting step of forming the scroll member and the shroud member by die-casting;

a machining step of forming the pressure-bonded section in one of the scroll member and the shroud member and forming the pressure-bonded section in the other of the scroll member and the shroud member by machining; and

and an assembling step of assembling the shroud member to the scroll member by press-fitting the press-fitting portion into the press-fitted portion, and press-contacting the pressure-bonding section to the pressure-bonded section to cause plastic flow to form the seal portion.

Thereby, the compressor housing for a turbocharger described above can be manufactured. Further, since the pressure-bonding section and the pressure-receiving section are formed by machining in the machining step, the surfaces can be roughened to some extent as compared with the surface of a casting by die casting, and therefore, the pressure-bonding section is easily caused to plastically flow in the assembling step, and the sealing property can be further improved.

Preferably, in the machining step, the pressure-bonding section is machined so as to have a radially protruding mountain shape in a cross section including a rotating shaft of the compressor impeller, and to have a starting end side inclined surface located on a starting end side in a pressing direction and a terminating end side inclined surface located on a terminating end side in the pressing direction, and an angle on an acute angle side of an angle formed by the terminating end side inclined surface and the rotating shaft is larger than an angle on an acute angle side of an angle formed by the starting end side inclined surface and the rotating shaft in the cross section. In this case, since the terminal-side inclined surface is made to rise more than the starting-side inclined surface with respect to the rotation axis by the machining in the machining step, the width of the pressure-bonding section can be narrowed while maintaining the inclination angle of the starting-side inclined surface and the projecting amount of the pressure-bonding section. Thus, the pressure-bonding section is easily plastically fluidized without deteriorating the assembling property in the assembling step. As a result, the fine gaps can be more reliably filled in the respective sealing portions formed in the assembly step, and the sealing performance can be further improved. Alternatively, by narrowing the width of the pressure-bonding section while maintaining the amount of plastic flow in the pressure-bonding section, dimensional tolerances of the pressure-bonding section and the pressure-receiving section can be relaxed in the machining step, and therefore productivity can be improved and cost reduction can be achieved.