CN111577660A

CN111577660A - Compressor housing for turbocharger and method for manufacturing same

Info

Publication number: CN111577660A
Application number: CN201911313551.2A
Authority: CN
Inventors: 矶谷知之
Original assignee: Odex GmbH
Current assignee: Odex GmbH
Priority date: 2019-02-18
Filing date: 2019-12-19
Publication date: 2020-08-25
Anticipated expiration: 2039-12-19
Also published as: JP2020133465A; US20200263701A1; CN111577660B; JP7228402B2

Abstract

The invention provides a compressor housing for a turbocharger, which can prevent the adhesion of deposits, has good assembly workability, can be easily molded by die casting, and has low cost for maintaining, improving the performance and increasing the supercharging pressure. A compressor housing (1) for a turbocharger has a refrigerant flow path (5) and a return portion (6), and is divided into a scroll member (2) and a sleeve member (3). The refrigerant flow path (5) is an annular space (50) formed by fitting a first flow path forming portion (51) and a second flow path forming portion (52) formed in the two members (2, 3). In the refrigerant flow path (5), the first press-fitting section (53b) of the sleeve member (3) is press-fitted into the first press-fitting section (53a) of the scroll member (2) at the inner peripheral seal section (53), and the second press-fitting section (54b) of the sleeve member (3) is press-fitted into the second press-fitting section (54a) of the scroll member (2) at the outer peripheral seal section (54). The return section (6) returns a part of the intake air that has reached the sleeve section (20) to the upstream of the compressor impeller (13).

Description

Compressor housing for turbocharger and method for manufacturing same

Technical Field

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

Background

A turbocharger mounted on an internal combustion engine of an automobile or the like has a compressor impeller and a turbine impeller, which are accommodated in a housing. The compressor impeller is disposed in an air flow path formed inside the casing. The air flow path includes an intake port for taking in air to the compressor impeller, a diffuser passage through which compressed air discharged from the compressor impeller passes, 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, as an internal combustion engine such as an automobile, there is known an internal combustion engine equipped with a blowby gas recirculation device (hereinafter, referred to as PCV) for recirculating blowby gas generated in a crankcase to an intake passage and purifying the crankcase or a head cover. In this case, there is a case where oil (oil mist) contained in blowby gas flows out from the PCV into the intake passage on the upstream side of the compressor in the turbocharger.

In this case, since the air temperature of the compressor is also increased when the outlet air pressure of the compressor is high, there is a problem that the oil flowing out of the PCV is condensed and highly viscous by evaporation, and thus deposits are formed and accumulated on a diffusion surface of the compressor housing for the turbocharger, a surface of the bearing housing facing the diffusion surface, or the like. Further, the accumulated deposits may 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, in order to prevent the deposition of the deposits in the diffusion passage as described above, the outlet air temperature of the compressor has been suppressed to some extent. 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 diffusion passage, a refrigerant flow passage is provided in the compressor housing for a turbocharger, and a refrigerant is caused to flow through the refrigerant flow passage, whereby a temperature rise of compressed air passing through the air flow passage in the housing is suppressed. In the structure disclosed in patent document 1, a compressor housing for a turbocharger is formed of a first member, a second member, and a third member, and the two members are assembled to define a refrigerant flow path.

[ Prior art documents ]

[ patent document ]

[ patent document 1 ] Japanese patent laid-open publication No. 2016-176353

Disclosure of Invention

Problems to be solved by the invention

However, in the structure disclosed in patent document 1, in order to ensure the liquid-tightness of the refrigerant flow path, it is necessary to form a holding portion for holding an O-ring as a sealing member between the first member and the second member, fit the sealing member into the holding portion, and further sandwich the sealing member between the first member and the second member. This leads to an increase in cost and a decrease in assembly workability due to an increase in the number of components.

In the structure disclosed in patent document 1, in order to mold each member by die casting, a shape without undercut is formed in consideration of mold release. Accordingly, the cross-sectional shape of the scroll chamber is greatly different from a circular shape, and therefore, the compression efficiency of the supplied air is reduced.

In addition, as a method of molding the refrigerant flow path in the compressor housing for a turbocharger, gravity casting using a sand core is considered. This method has a high degree of freedom in shape and can cope with even a complicated shape. However, in this method, since the casting cycle is long, it is necessary to perform a sand-falling operation for removing the sand core and an inspection operation for checking the remaining sand, and therefore, the number of manufacturing processes increases, and the production efficiency decreases.

Further, according to the structure of patent document 1, the refrigerant flow path is provided to prevent deposition, so that the compressor impeller can be increased in flow rate to improve the maximum output of the engine by high supercharging pressure, but when the compressor impeller is increased in flow rate, the low-speed torque of the engine is greatly reduced due to the difference in the cross-sectional shape of the scroll chamber.

The present invention has been made in view of the above-described background, and provides a compressor housing for a turbocharger that can prevent adhesion of deposits, has good assembly workability, can be easily molded by die casting, can maintain performance on the low air flow side at low cost, and can improve performance on the high air flow side.

One mode of the present invention is a compressor housing for a turbocharger that houses a compressor wheel, wherein,

the compressor housing for a turbocharger includes:

an air inlet forming portion that forms an air inlet that sucks air into the compressor impeller;

a sleeve portion having a sleeve face circumferentially surrounding and opposing the compressor wheel;

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

a scroll chamber forming portion that forms a scroll chamber that guides the compressed air that has passed through the diffuser passage to the outside;

a refrigerant flow path formed along the diffuser portion in the circumferential direction and through which a refrigerant for cooling the diffuser portion flows; and

a backflow portion configured to return a part of the intake air sucked from the intake port and reaching the sleeve portion to an upstream of the compressor impeller,

the compressor housing for a turbocharger is divided into a scroll member having at least a part of the intake port formation portion and at least a part of the scroll chamber formation portion, and a sleeve member having at least a part of the scroll chamber formation portion, the diffuser portion, and the sleeve portion, and being pressed into an inner side of the scroll member in an axial direction,

the refrigerant flow path is formed as an annular space divided by a first flow path forming portion and a second flow path forming portion formed at mutually opposing portions in the scroll member and the sleeve member, respectively,

the first flow passage forming portion and the second flow passage forming portion are fitted to each other at an inner peripheral sealing portion that seals an inner peripheral side of the refrigerant flow passage and at an outer peripheral sealing portion that seals an outer peripheral side of the refrigerant flow passage,

a first press-fitting portion formed in the sleeve member of the inner peripheral seal portion is press-fitted into a first press-fitting portion formed in the scroll member,

a second press-fitting portion formed in the sleeve member of the outer peripheral seal portion is press-fitted into a second press-fitting portion formed in the scroll member,

the reflow part has: a backflow chamber that is a space divided by a first backflow chamber forming portion and a second backflow chamber forming portion, the first backflow chamber forming portion and the second backflow chamber forming portion being formed at mutually opposing portions in the scroll member and the sleeve member, respectively; a communicating portion that is open at the sleeve surface and communicates with the return chamber; and a discharge portion that is open at a position upstream of the compressor impeller in the scroll member or the sleeve member and communicates with the return chamber.

According to the compressor housing for a turbocharger of the one aspect described above, the compressor housing for a turbocharger is formed separately, and the refrigerant flow path is formed by the first flow path forming portion and the second flow path forming portion formed at the mutually facing portions in the scroll member and the sleeve member, respectively. The inner and outer peripheries of the refrigerant flow path are sealed by an inner and outer sealing portions. In the inner peripheral seal portion, the first press-fitting portion of the sleeve member is press-fitted into the first press-fitting portion of the scroll member, and in the outer peripheral seal portion, the second press-fitting portion of the sleeve member is press-fitted into the second press-fitting portion of the scroll member. The return chamber in the return portion is formed by a space defined by a first return chamber forming portion and a second return chamber forming portion formed in mutually facing portions of the scroll member and the sleeve member, respectively. Thus, the return portion can be formed and the inner and outer peripheral sides of the refrigerant flow path can be sealed only by press-fitting the sleeve member into the scroll member, and the assembly workability is good without the need to sandwich the O-ring between the first flow path forming portion and the second flow path forming portion. Further, since no O-ring is required, the number of parts can be reduced. Further, the compressor housing for a turbocharger has a refrigerant flow path, and therefore, deposition of deposits in the diffuser passage can be suppressed, and high supercharging can be achieved on the high airflow side of the compressor (high rotation side of the engine), and the maximum output of the engine can be improved.

Further, the return portion may return a part of the intake air reaching the sleeve portion to the upstream side of the compressor impeller, thereby constituting a so-called casing process. Thus, even if the compressor impeller is increased in flow rate in response to an increase in the supercharging pressure, the operating range on the low air flow rate side can be maintained, and a decrease in low-speed torque can be prevented. That is, according to the compressor housing for a turbocharger, it is possible to achieve both the retention of the low-speed torque based on the retention of the operation range of the low air flow rate side by the return portion and the improvement of the maximum output based on the high supercharging by the refrigerant flow path.

Further, the compressor housing for a turbocharger is formed separately, and has a scroll member and a sleeve member, and the scroll chamber is formed by assembling at least two members to each other. Thus, the cross-sectional shape of the scroll chamber can be formed into a circular shape, and the scroll chamber forming portion can be formed into a shape without undercut. As a result, the compression efficiency of the supplied air can be improved, and the molding can be easily performed by die casting.

As described above, according to the present invention, it is possible to provide a compressor housing for a turbocharger which is excellent in assembling workability while preventing adhesion of deposits, can be easily molded by die casting, and can achieve high supercharging pressure at low cost.

In addition, the reference signs placed between parentheses in the claims and the summary of the invention indicate the correspondence with the specific components described in the following embodiments, and do not limit the technical scope of the present invention.

Drawings

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

Fig. 2 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in embodiment 1.

Fig. 3 is a sectional perspective view of the scroll member in embodiment 1.

Fig. 4 is a perspective view of a sleeve member in embodiment 1.

Fig. 5 is a sectional perspective view of the sleeve member in embodiment 1.

Fig. 6 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in embodiment 1.

Fig. 7 is a partially enlarged sectional view of a compressor housing for a turbocharger according to embodiment 1.

Fig. 8 is a sectional view of a compressor housing for a turbocharger in modification 1.

Fig. 9 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in modification 1.

Fig. 10 is another conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in modification 1.

Fig. 11 is a conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in modification 2.

Fig. 12 is another conceptual diagram for explaining a method of manufacturing a compressor housing for a turbocharger in modification 2.

Detailed description of the invention

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 an imaginary circle centered on the rotation shaft of the compressor impeller, and radially outward is a direction of a straight line extending from the center of the imaginary circle to a circumference.

Preferably, the scroll member and the sleeve member have contact portions that are brought into contact with each other in an axial direction to position the scroll member and the sleeve member at the time of pressing. In this case, since the axial direction Y in the press-fitting direction of the scroll member and the sleeve member is positioned by the contact portion, the assembling accuracy of the scroll member and the sleeve member can be improved.

The method for manufacturing a compressor housing for a turbocharger preferably includes: a molding step of molding the scroll member and the sleeve member by die casting, molding the first pressed portion and the second pressed portion in the scroll member by machining, and molding the first pressed portion, the second pressed portion, and the communication portion in the sleeve member; and an assembling step of forming the refrigerant flow path and the return portion by press-fitting the first press-fitting portion into the first press-fitting portion to form the inner peripheral seal portion and press-fitting the second press-fitting portion into the second press-fitting portion to form the outer peripheral seal portion, and assembling the sleeve member to the scroll member. In this case, the scroll member and the sleeve member are molded by die casting in the molding step, the first press-fitting portion and the second press-fitting portion are molded in the scroll member by machining, and the first press-fitting portion, the second press-fitting portion, and the communication portion are molded in the sleeve member. Further, since no O-ring is required, the number of parts can be reduced.

[ examples ] A method for producing a compound

(example 1)

Hereinafter, an embodiment of the compressor housing for a turbocharger will be described with reference to fig. 1 to 7.

As shown in fig. 1, a compressor housing 1 for a turbocharger accommodates a compressor impeller 13, and includes an intake port formation portion 10, a sleeve portion 20, a diffuser portion 30, a scroll chamber formation portion 120, a refrigerant flow path 5, and a return portion 6.

The air inlet forming portion 10 is formed with an air inlet 11 that sucks air into the compressor impeller 13.

The sleeve portion 20 has a sleeve face 21 that circumferentially surrounds the compressor wheel 13 and opposes the compressor wheel 13.

The diffuser 30 is formed on the outer peripheral side of the compressor impeller 13 in the circumferential direction, and is formed with a diffuser passage 15 through which the compressed air discharged from the compressor impeller 13 passes.

The scroll chamber forming portion 120 forms the scroll chamber 12 that guides the compressed air that has passed through the diffuser passage 15 to the outside.

The refrigerant flow path 5 is formed along the diffuser portion 30 in the circumferential direction, and circulates a refrigerant that cools the diffuser portion 30.

The recirculation portion 6 is configured to return a part of the intake air sucked from the intake port 11 and reaching the sleeve portion 20 to the upstream of the compressor impeller 13.

The compressor housing 1 for a turbocharger is divided into a scroll member 2 and a sleeve member 3, the scroll member 2 having at least a part of the intake port forming portion 10 and at least a part of the scroll chamber forming portion 120, and the sleeve member 3 having at least a part of the scroll chamber forming portion 120, the diffuser portion 30, and the sleeve portion 20 and being inserted inside the scroll member 2.

As shown in fig. 1 and 3, the refrigerant flow path 5 is formed as an annular space 50 divided by a first flow path forming portion 51 and a second flow path forming portion 52 formed in mutually facing portions of the scroll member 2 and the sleeve member 3, respectively.

The first flow channel formation part 51 and the second flow channel formation part 52 are fitted to each other at an inner peripheral sealing part 53 that seals the inner peripheral side of the refrigerant flow channel 5 and an outer peripheral sealing part 54 that seals the outer peripheral side of the refrigerant flow channel 5.

The inner peripheral seal portion 53 is formed by press-fitting a first press-fitting portion 53b formed in the sleeve member 3 into a first press-fitting portion 53a formed in the scroll member 2.

The outer peripheral seal portion 54 is formed by press-fitting a second press-fitting portion 54b formed in the sleeve member 3 into a second press-fitting portion 54a formed in the scroll member 2.

Further, as shown in fig. 1, the return portion 6 includes a return chamber 60, a communication portion 63, and a discharge portion 64, the return chamber 60 being a space divided by a first return chamber forming portion 61 and a second return chamber forming portion 62 formed at mutually opposing portions of the scroll member 2 and the sleeve member 3, respectively, the communication portion 63 being open at the sleeve surface 21 and communicating with the return chamber 60, and the discharge portion 64 being open at a position upstream of the compressor impeller 13 in the scroll member 2 or the sleeve member 3 and communicating with the return chamber 60.

The compressor housing 1 for a turbocharger of this example will be described in detail below.

As shown in fig. 1, a compressor housing 1 for a turbocharger is formed separately from a scroll member 2 and a sleeve member 3 which are formed as separate members. The compressor housing 1 for a turbocharger is attached to a flange portion of a bearing housing (not shown) that houses a bearing mechanism that supports the shaft 14, and the compressor impeller 13 is attached to one end of the shaft 14, or a seal plate 40 in the case of a separate structure.

As shown in fig. 1 and 3, the scroll member 2 includes an intake port forming portion 10, a first scroll chamber forming portion 121, an outer peripheral portion 125, a first flow path forming portion 51, a first return chamber forming portion 61, and a discharge portion 64. The intake port forming portion 10 is formed in a cylindrical shape and is formed to penetrate in the axial direction Y. The first scroll chamber forming portion 121 constitutes a wall surface of the intake side Y1 in the scroll chamber 12. As shown in fig. 1, the outer peripheral portion 125 is located on the opposite side Y2 of the intake side Y1 of the first scroll chamber forming portion 121, and forms the outer peripheral portion 125 of the compressor housing 1 for a turbocharger. A seal plate 40 is attached to the inner side of the outer peripheral portion 125.

As shown in fig. 1, a first flow passage forming portion 51 in the scroll member 2 forms a refrigerant flow path 5 together with a second flow passage forming portion 52 to be described later. As shown in fig. 3, the first flow path forming portion 51 has a first wall surface 511 which is a wall surface of the intake side Y1 in the refrigerant flow path 5. In this example, the first wall surface 511 is formed as a surface parallel to the radial direction. The first wall surface 511 need not be a flat surface, but may be a concave surface that is concave toward the intake side Y1.

As shown in fig. 1 and 2, a first press-fitting portion 53a is formed on the inner peripheral side of the first flow path forming portion 51, and a first press-fitting portion 53b of the sleeve member 3, which will be described later, is press-fitted into the first press-fitting portion 53 a. The inner peripheral seal portion 53 is formed by press-fitting the first press-fitting portion 53b into the first press-fitting portion 53 a. As shown in fig. 2, the first press-fitting portion 53a and the first press-fitting portion 53b abut against each other in the entire circumferential direction.

As shown in fig. 1, an outer peripheral portion of a second flow passage forming portion 52 in a sleeve member 3, which will be described later, is pressed into an inner peripheral side of a first scroll chamber forming portion 121 in a scroll member 2. Thereby, the second press-fitting portion 54b, which is the outer peripheral portion of the second flow path forming portion 2, is press-fitted into the second press-fitting portion 54a, which is the inner peripheral portion of the first scroll chamber forming portion 121, to form the outer peripheral seal portion 54. As shown in fig. 3, the second press-fitting portion 54a and the second press-fitting portion 54b abut against each other over the entire circumferential direction. The interference of the inner peripheral seal portion 53 and the outer peripheral seal portion 54 is not particularly limited, and may be appropriately determined in consideration of stress generated in the inner peripheral seal portion 53 and the outer peripheral seal portion 54, and in the present example, the interference of both is the same.

A sealing material may be interposed between one or both of the inner peripheral sealing portion 53 and the outer peripheral sealing portion 54. The kind of the sealing material is not particularly limited, but is preferably quick-drying. For example, a sealing material used as a liquid gasket may be used.

As shown in fig. 1 and 2, the scroll member 2 includes a refrigerant supply portion 58 and a refrigerant discharge portion 59 formed of through holes penetrating the first flow path forming portion 51 and communicating with the refrigerant flow path 5. The refrigerant supply portion 58 supplies the refrigerant to the refrigerant flow path 5, and the refrigerant discharge portion 59 discharges the refrigerant. In this example, as shown in fig. 1, the refrigerant supply portion 58 and the refrigerant discharge portion 59 extend from the first wall surface 511 in parallel with the axial direction Y toward the intake side Y1.

As shown in fig. 1 and 7, the scroll member 2 has a first contact surface 561 on the radially outer side of the outer peripheral seal portion 54 and on the radially inner side of the scroll chamber 12, and the first contact surface 561 is a wall surface parallel to the radial direction.

As shown in fig. 1, the first return chamber forming portion 61 in the scroll member 2 is constituted by a groove that is recessed toward the intake side Y1 at an opposing portion that opposes the sleeve member 3 in the axial direction Y. The discharge portion 64 is open on the inner side of the scroll member 2 and communicates with the first return chamber forming portion 61. The plurality of first reflow chamber forming portions 61 and the plurality of ejection portions 64 are provided, respectively, and are arranged in the circumferential direction.

On the other hand, as shown in fig. 2, the sleeve member 3 includes a second scroll chamber forming portion 122, the sleeve portion 20, the first diffuser portion 35, the second flow passage forming portion 52, the second return chamber forming portion 62, and a communication portion 63. The sleeve member 3 is formed in a tubular shape, and the first press-fitting portion 53b and the second press-fitting portion 54b of the sleeve member 3 are press-fitted into the first press-fitting portion 53a and the second press-fitting portion 54a of the scroll member 2.

As shown in fig. 1, the second scroll chamber forming portion 122 in the sleeve member 3 forms a wall surface on the inner peripheral side in the scroll chamber 12. The sleeve portion 20 forms a sleeve face 21 opposite the compressor wheel 13. The first diffuser portion 35 is formed with a diffuser surface 34 extending from the sleeve surface 21 toward the scroll chamber 12.

As shown in fig. 1, the second flow passage forming portion 52 of the sleeve member 3 forms the refrigerant flow passage 5 together with the first flow passage forming portion 51, and is provided on the intake side Y1 of the first diffuser portion 35. As shown in fig. 5, the second flow path forming portion 52 has a concave second wall surface 521 that is recessed toward the side Y2 opposite to the intake side Y1. In this example, the second wall surface 521 has a U-shape in a cross section parallel to the axial direction Y, and, as shown in fig. 4, an annular recess extending in the circumferential direction is formed radially outward of the sleeve surface 21. As shown in fig. 1 and 9, the second flow path forming portion 52 has a second contact surface 562 as a wall surface parallel to the radial direction on the radial direction outer side of the second wall surface 521. As shown in fig. 1, the second abutment surface 562 abuts the first abutment surface 561 of the turbine member 2 as described above. The refrigerant flow path 5 is formed as an annular space 50 between the first flow path forming portion 51 and the second flow path forming portion 52.

As shown in fig. 2, the second return chamber forming portion 62 in the sleeve member 3 is constituted by a groove that is recessed toward the opposite side Y2 of the intake side Y1 at an opposite portion of the sleeve member 3 that is opposite to the scroll member 2 in the axial direction Y. The communication portion 63 opens in a slit shape on the sleeve surface 21 and communicates with the first return chamber forming portion 61. The plurality of first reflow chamber forming portions 61 and the communication portions 63 are provided and arranged in the circumferential direction.

As shown in fig. 2, by fitting the sleeve member 3 to the scroll member 2, the first and second return

chamber forming portions

61 and 62 face each other to form the return chamber 60 as a space defined by the first and second return

chamber forming portions

61 and 62, as shown in fig. 1. The communication portion 63 opens at the sleeve surface 21 and communicates with the return chamber 60, and the blowing portion 64 is located upstream of the compressor impeller 13 and communicates with the return chamber 60. Thus, the recirculation portion 6 draws a part of the intake air reaching the sleeve portion 20 into the recirculation chamber 60 through the communication portion 63, and returns the intake air from the discharge portion 64 to the upstream side of the compressor impeller 13, thereby functioning as a casing process. The configuration of the return unit 6 is not particularly limited, and a known configuration having a casing processing function may be adopted.

As shown in fig. 1, the seal plate 40 includes a third scroll chamber forming portion 123, a seal plate insertion portion 41, and a second diffuser portion 36. The third scroll chamber forming portion 123 forms a wall surface on the outer peripheral side in the scroll chamber 12. The seal plate insertion portion 41 is inserted inside the outer peripheral portion 125. The second diffusion portion 36 forms the diffusion portion 30 together with the first diffusion portion 35. The second diffusion portion 36 has an opposing surface 37 opposing the diffusion surface 34 of the first diffusion portion 35 at a predetermined distance. And, the space between the diffusion surface 34 and the opposing surface 37 forms the diffusion path 15.

Next, a method for manufacturing the compressor housing 1 for a turbocharger of the present example will be described.

The method of manufacturing the compressor housing 1 for a turbocharger includes a molding step S1 and an assembling step S2. First, in the molding step S1, as shown in fig. 2, the turbine member 2 and the sleeve member 3 are each independently produced by die casting. Then, the first press-fitting portion 53a and the second press-fitting portion 54a are formed in the turbine member 2 by machining, and the first press-fitting portion 53b, the second press-fitting portion 54b, and the communication portion 63 are formed in the sleeve member 3.

Next, in the assembling step S2, as shown by an arrow P in fig. 2, the sleeve press-fitting portion 31 of the sleeve member 3 is press-fitted into the intake port forming portion 10 of the scroll member 2, and the second contact surface 562 of the sleeve member 3 is brought into contact with the first contact surface 561 of the scroll member 2. As a result, as shown in fig. 6, the refrigerant flow path 5 is formed as an annular space 50 between the first flow path forming portion 51 and the second flow path forming portion 52. At the same time, a return chamber 60 is formed between the first return chamber forming portion 61 of the scroll member 2 and the second return chamber forming portion 62 of the sleeve member 3, and the return chamber 60 communicates with the communication portion 63 and the discharge portion 64 to form the return portion 6. Further, as shown in fig. 1, a slight gap C is present between the first flow passage forming portion 51 in the scroll member 2 and the second return chamber forming portion 62 in the sleeve member 3 without abutting against each other. Thereby, the first abutment surface 561 and the second abutment surface 562 reliably abut.

Then, the sleeve member 3 is press-fitted into the scroll member 2, whereby the first press-fitting portion 53b of the sleeve member 3 is press-fitted into the first press-fitting portion 53a of the scroll member 2 to form the inner peripheral seal portion 53, and the second press-fitting portion 54b of the sleeve member 3 is press-fitted into the second press-fitting portion 54a of the scroll member 2 to form the outer peripheral seal portion 54. Thereby, in the refrigerant flow path 5, the space between the first flow path forming portion 51 and the second flow path forming portion 52 is sealed. In this example, the sleeve surface 21 is machined to ensure molding accuracy. Thereby, the compressor housing 1 for a turbocharger shown in fig. 1 is manufactured.

In the compressor housing 1 for a turbocharger, a refrigerant introduction pipe and a refrigerant discharge pipe, not shown, are connected to the refrigerant supply portion 58 and the refrigerant discharge portion 59 that communicate with the refrigerant flow path 5 shown in fig. 1 and 2, and the refrigerant flows through the refrigerant flow path 5 via the refrigerant introduction pipe and the refrigerant discharge pipe, whereby the diffuser surface 34 can be cooled.

After the molding step S1, the sealing material may be applied to the first press-fitting-target portion 53a or the first press-fitting portion 53b, and then the assembly step S2 may be performed to interpose the sealing material between the inner peripheral sealing portion 53. Similarly, after the molding step S1, the sealing material may be interposed in the outer peripheral sealing portion 54 by applying the sealing material to the second press-fitting portion 54a or the second press-fitting portion 54b and then performing the assembling step S2.

Next, the operation and effects of the compressor housing 1 for a turbocharger of the present example will be described in detail.

According to the compressor housing 1 for a turbocharger of the present example, the compressor housing 1 for a turbocharger is formed separately, and the refrigerant flow path 5 is formed by the first flow path forming portion 51 and the second flow path forming portion 52 formed at the mutually facing portions of the scroll member 2 and the sleeve member 3, respectively. The inner and outer peripheries of the refrigerant flow path 5 are sealed by an inner sealing portion 53 and an outer sealing portion 54. The inner peripheral seal portion 53 is formed by press-fitting the first press-fitting portion 53b of the sleeve member 3 into the first press-fitting portion 53a of the scroll member 2, and the outer peripheral seal portion 54 is formed by press-fitting the second press-fitting portion 54b of the sleeve member 3 into the second press-fitting portion 54a of the scroll member 2. The return chamber 60 in the return portion 6 is formed of a space divided by a first return chamber forming portion 61 and a second return chamber forming portion 62, and the first return chamber forming portion 61 and the second return chamber forming portion 62 are formed in mutually opposing portions of the scroll member 2 and the sleeve member 3, respectively. Thus, the return portion 6 can be formed and the inner and outer peripheral sides of the refrigerant flow path 5 can be sealed only by press-fitting the sleeve member 3 into the scroll member 2, and the assembly workability is good without interposing an O-ring between the first flow path forming portion 51 and the second flow path forming portion 52. Further, since no O-ring is required, the number of parts can be reduced. Further, the compressor housing 1 for a turbocharger is provided with the refrigerant flow path 5, so that deposition of deposits in the diffuser passage 15 can be suppressed, and high supercharging can be achieved on the high rotation side of the engine, and the maximum output of the engine can be improved.

Further, the compressor housing 1 for a turbocharger has a recirculation portion 6 capable of returning a part of intake air that has reached the sleeve portion 20 to the upstream side of the compressor impeller 13. The recirculation unit 6 constitutes a so-called casing process, and even if the compressor impeller 13 is increased in flow rate in response to an increase in the supercharging pressure, the operating range on the low air flow rate side can be maintained, and a decrease in the low speed torque can be prevented. That is, according to the compressor housing 1 for a turbocharger of the present embodiment, it is possible to achieve both the retention of the low-speed torque based on the retention of the operating range on the low air flow rate side by the return portion 6 and the improvement of the maximum output based on the high supercharging pressure by the refrigerant flow path 5.

Further, the compressor housing 1 for a turbocharger is formed separately, has a scroll member 2 and a sleeve member 3, and forms a scroll chamber 12 by assembling at least two members to each other. Thus, the cross-sectional shape of the scroll chamber 12 can be formed into a circular shape, and the scroll chamber forming portion 120 can be formed into a shape that can be released from the mold without undercut. As a result, the compression efficiency of the supplied air can be improved, and the molding can be easily performed by die casting.

Further, the refrigerant flow path 5 in the compressor housing 1 for a turbocharger of the present embodiment can be easily applied to a conventional compressor housing for a turbocharger because it is not necessary to significantly change the basic structure of the turbine member and the sleeve member in the conventional compressor housing for a turbocharger.

In the present embodiment, the turbine member 2 includes the refrigerant supply portion 58 formed of through holes communicating with the refrigerant passage 5 to supply the refrigerant to the refrigerant passage 5, and the refrigerant discharge portion 59 formed of through holes communicating with the refrigerant passage 5 to discharge the refrigerant from the refrigerant passage 5. This makes it possible to easily form the refrigerant supply portion 58 and the refrigerant discharge portion 59, and to reliably circulate the refrigerant through the refrigerant flow path 5.

In this example, a sealing material for sealing between the turbine member 2 and the sleeve member 3 may be interposed between at least one of the inner peripheral sealing portion 53 and the outer peripheral sealing portion 54. This improves the sealing performance of at least one of the inner peripheral seal portion 53 and the outer peripheral seal portion 54, prevents the refrigerant from leaking from the refrigerant passage 5, and improves the reliability.

In this example, the scroll member 2 and the sleeve member 3 have contact portions 56 that are opposed to each other in the axial direction Y and contact each other to perform positioning at the time of press-fitting. Thus, the contact portion 56 positions the scroll member 2 and the sleeve member 3 in the axial direction Y, which is the press-fitting direction, and therefore, the assembly accuracy of the scroll member 2 and the sleeve member 3 can be improved.

The method of manufacturing the compressor housing 1 for a turbocharger of this example includes a molding step S1 and an assembling step S2, wherein the scroll member 2 and the sleeve member 3 are molded by die casting in the molding step S1, the first press-fitting portion 53a and the second press-fitting portion 54a are molded in the scroll member 2 by machining, the first press-fitting portion 53b, the second press-fitting portion 54b, and the communicating portion 63 are molded in the sleeve member 3, and the refrigerant flow path 5 and the return portion 6 each including the annular space 50 are formed and the sleeve member 3 is assembled to the turbine member 2 by forming the inner peripheral seal portion 53 by press-fitting the first press-fitting portion 53b into the first press-fitting portion 53a and forming the outer peripheral seal portion 54 by press-fitting the second press-fitting portion 54b into the second press-fitting portion 54a in the assembling step S2. Thus, as described above, in the forming step S1, the scroll member 2 and the sleeve member 3 are formed by die-casting, the first press-fitting portion 53a and the second press-fitting portion 54a are formed in the scroll member 2 by machining, and the first press-fitting portion 53b, the second press-fitting portion 54b, and the communication portion 63 are formed in the sleeve member 3, and thereafter, in the assembling step S2, the backflow portion 6 can be formed and the inner peripheral side and the outer peripheral side of the refrigerant flow path 5 can be sealed only by press-fitting the sleeve member 3 into the scroll member 2, so that it is not necessary to sandwich an O-ring between the first flow path forming portion 51 and the second flow path forming portion 52, and the assembling workability is good. Further, since no O-ring is required, the number of parts can be reduced.

Further, in this example, the compressor housing 1 for a turbocharger is configured as two members including the scroll member 2 and the sleeve member 3, but may be configured as three members including the scroll member 2, the sleeve member 3, and the outer annular member 4 as in modification 1 shown in fig. 8. The outer annular member 4 is formed in an annular shape, and has a third scroll chamber forming portion 123 and an outer annular member insertion portion 410. The outer peripheral ring member insertion portion 410 is press-fitted into the outer peripheral portion 125 to form the press-fitting portion 42. In modification 1, the same components as those in embodiment 1 are denoted by the same reference numerals, and descriptions thereof are omitted.

Next, a method for manufacturing the compressor housing 1 for a turbocharger of modification 1 will be described. First, as shown in fig. 9, in the molding step S1, the turbine member 2 is compression-molded in the same manner as in example 1. Further, an integral member 3a is die-cast, and the integral member 3a is formed by integrally connecting the outer peripheral portion of the sleeve member 3 and the inner peripheral portion of the outer peripheral annular member 4 having the outer shape of the outer peripheral annular member 4 via a connecting portion 4a in embodiment 1. Then, the first press-fitting portion 53a and the second press-fitting portion 54a are formed in the scroll member 2 by machining, and the first press-fitting portion 53b, the second press-fitting portion 54b, and the communication portion 63 are formed in the sleeve member 3. Thereafter, in the assembling step S2, the integrated member 3a is press-fitted into the scroll member 2 in the direction of the arrow P. Then, the connecting portion 4a shown in fig. 10 is cut, and the sleeve member 3 and the outer annular member 4 are separated from each other in a state where they are press-fitted into the scroll member 2. Thus, the compressor housing 1 for a turbocharger of modification 1 is manufactured.

The compressor housing 1 for a turbocharger of modification 1 can also exhibit the same operational effects as those of embodiment 1. The interference of the press-fitting portion 42 formed by press-fitting the outer annular member 4 is preferably smaller than the interference of the inner and

outer sealing portions

53 and 54. In this case, the operation of pushing the integrated member 3a into the scroll member 2 can be easily performed. In addition, misalignment between the press-fitting portion (the inner peripheral seal portion 53 and the outer peripheral seal portion 54) of the sleeve member 3 and the press-fitting portion 42 of the outer peripheral annular member 4 can be absorbed.

In the compressor housing 1 for a turbocharger of modification 1, as shown in fig. 8 and 10, in the assembling step S2, the portion of the outer annular member 4 of the integrated member 3a does not abut against the scroll member 2 in the axial direction, and a gap B is formed. Therefore, when the integrated member 3a is pressed, the first contact surface 561 can be brought into contact with the second contact surface 562. This enables the axial direction press-fitting position of the integrated member 3a to be determined with further high accuracy. That is, the final positioning of the sleeve member 3 in the axial direction can be performed with further high accuracy. After the assembling step S2, the outer annular member 4 separated from the integrated member 3a is further press-fitted into contact with the scroll member 2 in the axial direction, whereby the outer annular member 4 can be accurately positioned in the axial direction.

In example 1, the refrigerant flow path 5 is formed by die casting, but alternatively, as in modification 2 shown in fig. 11, the second flow path forming portion 52 may be formed by die casting at a predetermined depth in the forming step S1, and then the bottom portion of the second wall surface 521 that is recessed toward the Y2 side, that is, the cut portion 52a that is the portion of the second wall surface 521 closest to the Y2 side may be cut out, and the second flow path forming portion 52 may be formed into a deeper recessed shape as shown in fig. 12. In modification 2, as shown in fig. 11, the thickness of the diffuser portion 30 can be secured to some extent during die-casting, and hence formability can be improved. Furthermore, as shown in fig. 12, since the refrigerant flow path 5 can be formed at a position close to the diffuser surface 34, the cooling effect of the diffuser surface 34 can be improved, and the adhesion of the deposits can be further prevented. In addition, the same operational effects as in the case of embodiment 1 are obtained in this example. In addition, in modification 2, a three-member structure can be formed as in modification 1.

The present invention is not limited to the above-described embodiments and modifications, and can be applied to various embodiments and modifications without departing from the scope of the present invention.

[ description of reference ]

1 compressor housing for turbocharger

2 scroll Member

20 sleeve part

21 sleeve surface

3 Sleeve Member

30 diffusion part

5 refrigerant flow path

51 first channel forming part

52 second flow path forming part

53 inner peripheral seal part

53a first pressed part

53b first press-fitting part

54 peripheral seal portion

54a second pressed part

54b second press-fitting portion

56 abutting part

6 reflux part

60 reflow chamber

61 first reflow chamber forming part

62 second reflow chamber forming part

63 communication part

64 discharge part

Claims

1. A compressor housing for a turbocharger that houses a compressor wheel, wherein the compressor housing for a turbocharger has:

2. A compressor housing for a turbocharger according to claim 1, wherein said scroll member and said sleeve member have abutting portions that perform said positioning at the time of press-in by contacting each other oppositely in an axial direction.

3. A manufacturing method of manufacturing the compressor housing for turbochargers according to claim 1 or 2, wherein the manufacturing method of the compressor housing for turbochargers comprises:

a molding step of molding the scroll member and the sleeve member by die casting, molding the first pressed portion and the second pressed portion in the scroll member by machining, and molding the first pressed portion, the second pressed portion, and the communication portion in the sleeve member;

and an assembling step of forming the refrigerant flow path and the return portion by press-fitting the first press-fitting portion into the first press-fitting portion to form the inner peripheral seal portion and press-fitting the second press-fitting portion into the second press-fitting portion to form the outer peripheral seal portion, and assembling the sleeve member to the scroll member.