JP4807271B2 - Variable capacity turbocharger - Google Patents

Description

  The present invention relates to a variable displacement supercharger, and more particularly to a variable displacement supercharger that variably sets a gas flow rate flowing into a turbine by a rotatable nozzle vane.

  As a turbocharger used in vehicles such as automobiles, a variable capacity that variably sets the gas flow rate (flow velocity) flowing into the turbine by changing the flow passage cross-sectional area of the nozzle throat (throttle part) with a rotatable nozzle vane A type of turbocharger is known.

Such a variable capacity supercharger has, on the gas inlet side of the turbine, a first annular side wall surface concentric with the center of rotation of the turbine impeller of the turbine and facing each other at a predetermined interval in the axial direction. An annular gas inlet space is defined by the second annular sidewall surface, and a plurality of nozzle vanes are respectively sandwiched between the first annular sidewall surface and the second annular sidewall surface in the gas inlet space. The nozzle throat portion is formed between the adjacent nozzle vanes, and the gas flow rate flowing into the turbine is variably set according to the rotation angle of the nozzle vanes (for example, Patent Document 1). .
JP 2003-27951 A

  Generally, the side surface of the nozzle vane and the first and second annular side wall surfaces are parallel surfaces facing each other over the entire region, and between the side surface of the nozzle vane and the first and second annular side wall surfaces. Is set with a gap (side clearance) necessary for the rotation of the nozzle vane. This gap is set to a value as small as possible because it causes a decrease in gas flow rate setting accuracy and a decrease in turbine efficiency due to a gas leak.

  However, on the other hand, the supercharger nozzle vane is exposed to severe conditions due to high-temperature exhaust gas, and the fitting tolerance between the support shaft provided in the nozzle vane and the bearing hole provided on the support member side, Due to thermal deformation of the nozzle vane and peripheral members, the rotation center axis of the nozzle vane may be tilted from the normal posture. When the nozzle vane is tilted, the gap is narrow, so that the side surface of the nozzle vane contacts and interferes with the first annular side wall surface and the second annular side wall surface, and the nozzle vane cannot rotate properly due to the sticking. There is a risk that the flow rate cannot be controlled correctly.

  On the other hand, if the gap is set wide, the amount of gas leak increases, the setting accuracy of the gas flow rate flowing into the turbine is lowered, and the turbine efficiency is also lowered. This becomes a problem particularly when the flow rate of gas flowing into the turbine is reduced.

  The present invention has been made in view of the above problems, and provides an appropriate gap between the side surface of the nozzle vane and the first and second annular side wall surfaces, without increasing the amount of gas leakage, or gas leakage. To provide a variable capacity supercharger that minimizes the volume and avoids nozzle vane sticking, and particularly achieves both high operating reliability at high temperatures and no increase in gas leakage at low flow rates. For the purpose.

According to the first aspect of the present invention, a first annular side wall surface concentric with a rotation center of the turbine impeller of the turbine and opposed to each other at a predetermined interval in the axial direction is provided on the gas inlet side of the turbine. An annular gas inlet space is defined by the annular side wall surface, and a plurality of nozzle vanes are respectively sandwiched between the first annular side wall surface and the second annular side wall surface in the gas inlet space. And a variable capacity supercharger that variably sets the flow rate of gas flowing into the turbine by the nozzle vane, the nozzle vane having support shafts that protrude outward from both side surfaces of the nozzle vane. Each support shaft is fitted in a bearing hole formed in each of the first member constituting the first annular side wall surface and the second member constituting the second annular side wall surface. According to the first A support member is rotatably supported by the member and the second member, and a flange portion having an outer flange surface on the same plane as the side surface of the nozzle vane is formed concentrically with the support shaft on both side portions of the nozzle vane. and has, toward the outer peripheral side of the from the rotation center side of the nozzle vane gas inlet space, the the other side of the gap and the nozzle vane of the first side surface and said first annular side wall surface of the nozzle vane first Rotation of the nozzle vane excluding a region corresponding to the flange portion of the first annular side wall surface and the second annular side wall surface so that a gap between the second annular side wall surface is enlarged. The outer peripheral side from the center position is a conical inclined surface, and the region corresponding to the flange portion of the first annular side wall surface and the second annular side wall surface is the outer side surface. In a plane parallel to the surface And wherein the are.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the one side surface of the nozzle vane and the first side are arranged from the rotation center side of the nozzle vane toward the inner peripheral side of the gas inlet space. The first annular side wall surface and the second annular side wall surface so that the gap between the second annular side wall surface and the other side surface of the nozzle vane and the second annular side wall surface are enlarged. Of these, the inner peripheral side of the nozzle vane excluding the region corresponding to the flange is a conical inclined surface .

The invention according to claim 3 is characterized in that, in addition to the configuration of the invention according to claim 1 or 2, the inclined surface is a linearly inclined tapered surface or a convex curved surface .

According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects , the nozzle vanes adjacent to each other among the first annular side wall surface and the second annular side wall surface. The region corresponding to the nozzle throat portion formed therebetween is a plane parallel to the side surface of the nozzle vane .

  In the variable capacity supercharger according to the present invention, the outer peripheral side of each of the first annular side wall surface and the second annular side wall surface from the rotation center position of the nozzle vane is a conical inclined surface. Since the gap between the side surface of the nozzle vane and the first and second annular side wall surfaces increases from the rotation center side of the nozzle vane toward the outer peripheral side of the gas inlet space, the rotation center axis of the nozzle vane is regular. Even if the nozzle vane is inclined from the posture, it is possible to avoid the contact interference between the nozzle vane and the first and second annular side wall surfaces, and the operation reliability at high temperature is improved.

  When the flow rate is small, the elevation angle of the nozzle vane is small, and the nozzle vane posture is in a posture along the arc direction of the first and second annular side wall surfaces, so the side surface of the nozzle vane and the first and second annular side wall surfaces There is no large gap between them, and the amount of gas leakage at a small flow rate does not increase. This prevents a decrease in gas flow rate setting accuracy and a decrease in turbine efficiency at a small flow rate.

  One embodiment of a variable capacity supercharger according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the variable displacement supercharger 1 includes a bearing housing 17, a compressor housing 19 integrally assembled on one end side of the bearing housing 17, and the other end portion of the bearing housing 17. A housing (housing) 3 is formed by a turbine housing 21 integrally assembled on the side.

  A centrifugal compressor 5 is provided on one end side of the housing 3, and a radial turbine 7 is provided on the other end side.

  The bearing housing 17 located between the radial turbine 7 and the centrifugal compressor 5 supports the rotary shaft member 9 penetrating the bearing housing 17 by the bearing portion 11 so as to be rotatable.

  A compressor impeller 13 that is in the compressor housing 19 and constitutes the centrifugal compressor 5 is integrally fixed to one end of the rotary shaft member 9.

  A turbine impeller 15 that forms the radial turbine 7 in the turbine housing 21 is integrally formed at the other end of the rotating shaft member 9.

  The turbine housing 21 is provided with a scroll passage 23 having a gas inlet (not shown) at one end. An annular gas inlet space (gas passage) 25 for the turbine impeller 15 is formed on the inner peripheral side of the scroll passage 23 (between the scroll passage 23 and the turbine impeller 15).

  Exhaust gas coming out of the engine of the automobile passes through the scroll passage 23 and the gas inlet space 25 and is supplied to the radial turbine 7 to rotate the turbine impeller 15. The rotation of the turbine impeller 15 is transmitted to the compressor impeller 13 by the rotating shaft member 9, and the compression of the air is performed in the centrifugal compressor 5 by the rotation of the compressor impeller 13.

  The gas inlet space 25 is formed by a shroud (first member) 26 that is concentric with the rotation center of the turbine impeller 15 and faces the blade tip of the turbine impeller 15 at a predetermined interval on the gas inlet side of the radial turbine 7. The first annular side wall surface 51 and the second annular side wall surface 52 defined by the nozzle support ring (second member) 28 are defined.

  The shroud 26 and the nozzle support ring 28 are fixedly connected to each other at a predetermined interval in the axial direction by a plurality of interval setting pins 47 which are caulked to these. A fixed coupling body of the shroud 26 and the nozzle support ring 28 is fixedly supported by the mounting member 49 from the housing 3.

  In the gas inlet space 25, a plurality of strip-shaped nozzle vanes 31 are rotatably provided in a manner sandwiched between a first annular side wall surface 51 and a second annular side wall surface 52, respectively. The nozzle vane 31 integrally includes support shafts 53 and 54 that protrude outward from both side surfaces of the nozzle vane 31, and the support shaft 53 is fitted into a bearing hole 55 formed in the shroud 26, and the support shaft 54 is a nozzle. By being rotatably fitted in a bearing hole 55 formed in the support ring 28, both are supported so as to be rotatable about the support shafts 53 and 54 as a rotation center, and the radial turbine 7 is rotated according to the rotation angle. The flow rate of gas flowing into The rotation center axis line (center axis line of the support shafts 53 and 54) CL2 (see FIG. 2) of each nozzle vane 31 is parallel to the center axis line CL1 of the rotary shaft member 9.

As shown in FIG. 2, the nozzle vane 31 has circular flange portions 57 and 58 having outer flange surfaces 57A and 58A that are flush with the side surfaces 31A and 31B of the nozzle vane 31, respectively (see FIG. 2). There is integrally formed with the support shaft 53, 54 concentric. The outer flange surfaces 57A and 58A are opposed to the first annular side wall surface 51 and the second annular side wall surface 52 with a small gap therebetween, and between the support shafts 53 and 54 and the bearing holes 55 and 56, respectively. It has a seal that reduces gas leakage from the air gap.

  As shown in FIG. 1, the support shafts 54 of the nozzle vanes 31 are connected to each other by a connection link 43, and the connection link 43 is connected to a drive lever 45 by a drive shaft 39. When the connecting link 43 is driven by the drive lever 45, the support shafts 54 of the nozzle vanes 31 are simultaneously rotated in the same rotation direction by the same rotation angle. Thereby, the rotation angles (elevation angles) of all the nozzle vanes 31 are set to be the same at the same time.

  For example, the nozzle vane 31 is configured to rotate between a rotation posture indicated by a solid line in FIG. 3 and a rotation posture indicated by a two-dot chain line. When each nozzle vane 31 is in the rotational posture shown by the solid line in FIG. 3, the flow passage cross-sectional area (gas flow passage width) of the nozzle throat portion t formed between the adjacent nozzle vanes 31 is the smallest and the minimum flow rate is set. When each nozzle vane 31 is in the rotational posture indicated by the phantom line in FIG. 3, the flow passage cross-sectional area (gas flow passage width) of the nozzle throat portion t is the largest and the maximum flow rate is set.

  Thus, by rotating the nozzle vanes 31 in the same manner, the size of the nozzle flow path (nozzle throat portion t) can be changed, and the flow velocity of the gas flowing into the radial turbine 7 (nozzle throat portion t is changed). The gas flow rate (passing through) can be continuously changed.

As shown in FIG. 2, the rotation of the nozzle vane 31 excluding the regions 51C and 52C corresponding to the flange portions 57 and 58 of the first annular side wall surface 51 and the second annular side wall surface 52. The gap Ga between the one side surface 31A of the nozzle vane 31 and the first annular side wall surface 51 and the nozzle vane 31 extend from the center position toward the outer periphery side of the gas inlet space 25 from the rotation center side of the nozzle vane 31. Conical inclined surfaces (taper surfaces) 51A and 52A are formed so that the gap Gb between the other side surface 31B and the second annular side wall surface 52 is enlarged.

  Of the first annular side wall surface 51 and the second annular side wall surface 52, the inner peripheral side of the rotation center position of the nozzle vane 31 includes a region corresponding to the nozzle throat portion t, and the side surface 31 </ b> A of the nozzle vane 31. , 31B and vertical planes 51B and 52B parallel to each other with a minute gap. The vertical planes 51B and 52B are enlarged to areas 51C and 52C (see FIG. 4) corresponding to the flanges 57 and 58.

  Accordingly, the inclined surfaces 51A and 52A are limited to the region indicated by cross hatching in FIG.

  As described above, since the inclined surfaces 51A and 52A are set, the gaps Ga and Gb between the side surfaces 31A and 31B of the nozzle vane 31 and the first and second annular side wall surfaces 51 and 52 are rotated by the rotation of the nozzle vane 31. Since the nozzle vane 31 is enlarged from the moving center side toward the outer peripheral side of the gas inlet space 25, even if the rotation center axis CL2 of the nozzle vane 31 is tilted from the normal posture shown in FIG. Contact interference with the second annular side wall surfaces 51 and 52 is avoided, and the nozzle vane 31 is prevented from sticking. Thereby, the operation reliability at high temperature is improved.

  When the flow rate is small, as shown by the solid line in FIG. 3, the elevation angle of the nozzle vane 31 is small, and the nozzle vane posture is the first and second annular shapes as compared with the case of the large flow rate indicated by the phantom line in FIG. Since the side wall surfaces 51 and 52 are in a posture along the arc direction, there is no large gap between the side surfaces 31A and 31B of the nozzle vane 31 and the first and second annular side wall surfaces 51 and 52. The amount of gas leak does not increase. This prevents a decrease in gas flow rate setting accuracy and a decrease in turbine efficiency at a small flow rate.

  Further, the nozzle throat portion t is formed on the inner peripheral side of the gas inlet space 25 from the center of rotation of the nozzle vane 31 when viewed from the gas flow flowing through the nozzle, so that the outer periphery of the gas inlet space 25 on the upstream side of the nozzle throat portion t. On the side, the gap between the side surface of the nozzle vane and the first and second annular side wall surfaces is enlarged from the rotation center side of the nozzle vane toward the outer peripheral side of the gas inlet space, and the amount of gas leakage at this portion increases. However (because the gas flow rate is determined by the nozzle throat portion t), the gas flow setting accuracy is not lowered and the turbine efficiency is not lowered.

  And among the 1st annular side wall surface 51 and the 2nd annular side wall surface 52, the inner peripheral side from the rotation center position of the nozzle vane 31 includes the area | region corresponding to the nozzle throat part t, Since the vertical planes 51B and 52B are parallel to the side surfaces 31A and 31B with a minute gap, the amount of gas leakage at the nozzle throat portion t is small, and high-accuracy and accurate gas flow rate setting is performed at the nozzle throat portion t. .

  Further, since the vertical planes 51B and 52B of the first annular side wall surface 51 and the second annular side wall surface 52 are expanded to the regions 51C and 52C corresponding to the flange portions 57 and 58, the first circle The sealing effect by the annular side wall surface 51, the second annular side wall surface 52, and the outer flange surfaces 57A, 58A is kept good.

  The inclination of the inclined surface 51A and the inclination of the inclined surface 52A are different in the amount of thermal deformation between the shroud 26 and the nozzle support ring 28, and the nozzle vane 31 is inclined to either the shroud 26 side or the nozzle support ring 28 side. Considering whether it is easy or the like, different appropriate values may be set.

  Another embodiment of the variable capacity supercharger according to the present invention will be described with reference to FIGS. 5 to 7, portions corresponding to those in FIGS. 2 to 4 are denoted by the same reference numerals as those in FIGS. 2 to 4, and description thereof is omitted.

  In this embodiment, the outer peripheral side of the first annular side wall surface 51 and the second annular side wall surface 52 from the rotational center position of the nozzle vane 31 is a conical inclined surface 51A, 52A, respectively. In addition, the inner circumferential side of the rotation center position of the nozzle vane 31 moves from the rotation center side of the nozzle vane 31 toward the inner circumferential side of the gas inlet space 25 and the one side surface 31A of the nozzle vane 31 and the first circle. The conical inclined surfaces (tapered surfaces) 51D and 52D are respectively formed so that the gap Gc with the annular side wall surface 51 and the gap Gd between the other side surface 31B of the nozzle vane 31 and the second annular side wall surface 52 are enlarged. It has become.

  Of the first annular side wall surface 51 and the second annular side wall surface 52, the rotation center position portion of the nozzle vane 31 is an area corresponding to the nozzle throat portion t and an area 51C corresponding to the flange portions 57 and 58. , 52C (see FIG. 7), the flat surfaces 51B and 52B are parallel to the side surfaces 31A and 31B of the nozzle vane 31 with a small gap therebetween.

  Thereby, inclined surface 51A, 52A, 51D, 52D is restricted to the area | region shown by cross hatching in FIG.

  In this embodiment, inclined surfaces 51A and 52A are set, and the gaps Ga and Gb between the side surfaces 31A and 31B of the nozzle vane 31 and the first and second annular side wall surfaces 51 and 52 are from the rotation center side of the nozzle vane 31. In addition to being enlarged toward the outer peripheral side of the gas inlet space 25, inclined surfaces 51D and 52D are set, and the side surfaces 31A and 31B of the nozzle vane 31 and the first and second annular side wall surfaces 51 and 52, The gaps Gc and Gd of the nozzle vane 31 are enlarged from the rotation center side of the nozzle vane 31 toward the inner peripheral side of the gas inlet space 25. Therefore, even if the rotation center axis CL2 of the nozzle vane 31 is inclined from the normal posture, the nozzle vane 31 Contact interference with the first and second annular side wall surfaces 51 and 52 is more reliably avoided, and the nozzle vane 31 is more securely fixed. It is avoided. Thereby, the operation reliability at high temperature is further improved.

  Of the first annular side wall surface 51 and the second annular side wall surface 52, the region corresponding to the nozzle throat portion t is a vertical plane 51B parallel to the side surfaces 31A and 31B of the nozzle vane 31 with a small gap. 52B, the amount of gas leakage at the nozzle throat portion t is small, and a highly accurate and accurate gas flow rate setting is performed at the nozzle throat portion t.

  Also in this embodiment, the vertical planes 51B and 52B of the first annular side wall surface 51 and the second annular side wall surface 52 are expanded to the regions 51C and 52C corresponding to the flange portions 57 and 58, respectively. The sealing effect by the first annular side wall surface 51, the second annular side wall surface 52, and the outer flange surfaces 57A, 58A is kept good.

The inclinations of the inclined surfaces 51A, 52A, 51D, and 52D are also different in the amount of thermal deformation between the shroud 26 and the nozzle support ring 28, the difference in the amount of thermal deformation between the inlet side and the outlet side of the gas inlet space 25, and the nozzle vane. In consideration of which side of the shroud 26 side and the nozzle support ring 28 side is liable to be inclined 31 or the like, the respective inclined surfaces 51A, 52A, 51D, and 52D may be set to different appropriate values. In this embodiment, the taper surface is linearly inclined, but may be a convex curved surface as shown in FIG. This convex curved surface is not a round surface having a convex arc slope shape but a convex curved surface and includes splines.

  In FIG. 8, parts corresponding to those in FIG. 5 are denoted by the same reference numerals as those in FIG. 5, and description thereof is omitted.

It is a whole lineblock diagram showing one embodiment of a variable capacity type supercharger by this invention. It is an enlarged view of the principal part of one Embodiment of the variable capacity | capacitance supercharger by this invention. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 3 is a cross-sectional view in a state in which a nozzle vane along line III-III in FIG. 2 is removed. It is an enlarged view of the principal part of other embodiment of the variable capacity | capacitance supercharger by this invention. FIG. 6 is a cross-sectional view taken along line VI-V in FIG. 5. It is sectional drawing in the state which removed the nozzle vane along line VI-VI of FIG. It is an enlarged view of the principal part of one Embodiment of the variable capacity | capacitance supercharger by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable capacity supercharger 3 Housing 5 Centrifugal compressor 7 Radial turbine 9 Rotary shaft member 11 Bearing part 13 Compressor impeller 15 Turbine impeller 17 Bearing housing 19 Compressor housing 21 Turbine housing 23 Scroll path 25 Gas inlet space 26 Shroud 28 Nozzle support Ring 31 Nozzle vane 31A, 31B Side surface 39 Drive shaft 45 Drive lever 49 Mounting member 51 First annular side wall surface 51A Inclined surface 51B Vertical plane 51C Region 51D Inclined surface 52 Second annular side wall surface 52A Inclined surface 52B Vertical plane 52C Region 52D Inclined surface 53, 54 Support shaft 55, 56 Bearing hole 57, 58 collar 57A, 58A Outer collar

Claims (4)

Annulus is formed on the gas inlet side of the turbine by a first annular side wall surface and a second annular side wall surface that are concentric with the rotation center of the turbine impeller of the turbine and face each other at a predetermined interval in the axial direction. Gas inlet space is defined, and a plurality of nozzle vanes are rotatably provided in the gas inlet space in a manner sandwiched between the first annular side wall surface and the second annular side wall surface, respectively. A variable capacity supercharger that variably sets a flow rate of gas flowing into the turbine by the nozzle vane;
The nozzle vane has support shafts that protrude outward from both side surfaces of the nozzle vane, and each support shaft includes a first member that constitutes the first annular side wall surface and the second annular side wall surface. By being fitted into bearing holes formed respectively in the second member that constitutes, both the first member and the second member are rotatably supported by the first member,
On both sides of the nozzle vane, flanges each having an outer flange surface that is flush with the side surface of the nozzle vane are formed concentrically with the support shaft,
The gap between one side surface of the nozzle vane and the first annular side wall surface and the other side surface of the nozzle vane and the second circle as it goes from the rotation center side of the nozzle vane toward the outer peripheral side of the gas inlet space. From the rotation center position of the nozzle vane excluding the region corresponding to the flange portion of the first annular side wall surface and the second annular side wall surface so that the gap with the annular side wall surface is enlarged. Each outer peripheral side has a conical inclined surface ,
Of the first annular side wall surface and the second annular side wall surface, a region corresponding to the flange portion is a plane parallel to the outer flange surface. Feeder. The gap between one side surface of the nozzle vane and the first annular side wall surface and the other side surface of the nozzle vane and the second side as it goes from the rotation center side of the nozzle vane toward the inner peripheral side of the gas inlet space. An inner peripheral side of the nozzle vane excluding a region corresponding to the flange portion of each of the first annular side wall surface and the second annular side wall surface so that a gap with the annular side wall surface is enlarged. 2. The variable capacity supercharger according to claim 1, wherein the variable capacity supercharger has a conical inclined surface.   3. The variable capacity supercharger according to claim 1, wherein the inclined surface is a linearly inclined tapered surface or a convex curved surface. Of the first annular side wall surface and the second annular side wall surface, the region corresponding to the nozzle throat portion formed between the adjacent nozzle vanes is a plane parallel to the side surface of the nozzle vane. The variable capacity supercharger according to any one of claims 1 to 3 , wherein

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