Turbocharger

Abstract

To provide a turbocharger capable of reducing variation of flow rate characteristics in a region where an opening of a variable nozzle unit is large.SOLUTION: A turbocharger includes a turbine wheel 4, a variable nozzle unit 20, a drive lever 31, a drive shaft 32, a drive actuator 40, a rod 50 and a link 60. The drive actuator 40 includes an actuator body 42 and an actuator lever 44. The rod 50 includes an actuator side end part 51 and a link side end part 52. The link 60 includes a drive shaft connection part 61 and a rod connection part 62. At least one of the actuator lever 44, the rod 50 and the link 60 includes a change part capable of changing a ratio of length between the drive shaft 32 and the link side end part 52 to length between an output shaft 42a and the actuator side end part 51.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a turbocharger. [Background technology]

[0002] Conventionally, turbochargers capable of adjusting flow rate have been known. For example, Japanese Patent Application Laid-Open Publication No. 2013-124581 discloses a variable geometry turbocharger including an exhaust turbine, a variable nozzle, an arm, a power transmission member, an actuator, and a stopper member. The opening of the variable nozzle is set to be smallest at the position where the arm abuts against the stopper member. In this turbocharger, the abutment position between the arm and the stopper member is adjusted to adjust the variation in the point where the opening of the variable nozzle is smallest (full closure point). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-124581 Summary of the Invention [Problem to be solved by the invention]

[0004] In turbochargers such as that described in JP 2013-124581 A, there are individual differences in the flow characteristics of the variable nozzle (the ratio of the increase in flow rate to the increase in the opening of the variable nozzle), and the variation in flow characteristics may increase as the opening of the variable nozzle increases. For this reason, there is a concern that simply adjusting the contact position (full closure point) between the arm and the stopper member may not be enough to absorb the variation in flow characteristics, especially in the region where the opening of the variable nozzle is large.

[0005] An object of the present invention is to provide a turbocharger that can reduce variations in flow characteristics in a range where the opening degree of the variable nozzle unit is large. [Means for solving the problem]

[0006] A turbocharger according to one aspect of the present disclosure includes a turbine wheel, a variable nozzle unit capable of adjusting the size of a flow path area of ​​an exhaust flow path for exhaust gas, a drive lever that drives the variable nozzle unit, a drive shaft connected to the drive lever and rotating together with the drive lever about a central axis of the drive shaft, a drive actuator for driving the variable nozzle unit, a rod connected to the drive actuator, and a link that connects the rod and the drive shaft, wherein the drive actuator includes an actuator body having an output shaft, and an actuator connected to the output shaft and rotatable about the output shaft. and a actuator lever, wherein the rod has an actuator side end connected to the actuator lever so as to be rotatable relative to the actuator lever, and a link side end connected to the link so as to be rotatable relative to the link, the link including a drive shaft connection portion connected to the drive shaft and a rod connection portion connected to the link side end, and at least one of the actuator lever, the rod, and the link includes a change portion that can change the ratio of the length between the drive shaft and the link side end to the length between the output shaft of the actuator body and the actuator side end. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a turbocharger that can reduce variations in flow characteristics in a range where the opening degree of the variable nozzle unit is large. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a turbocharger according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view schematically showing a configuration of a part of the turbocharger. [Figure 3]FIG. [Figure 4] 10 is a diagram schematically showing the relationship between the length between the output shaft and the actuator side end of the actuator body and the length between the drive shaft and the link side end. FIG. [Figure 5] FIG. 10 is a diagram schematically illustrating a modified example of the rod. [Figure 6] FIG. 10 is a diagram schematically illustrating a modified example of the actuator lever. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] Fig. 1 is a diagram schematically showing the configuration of a turbocharger according to one embodiment of the present disclosure. As shown in Fig. 1, the turbocharger 1 includes a compressor wheel 2, a compressor housing 3, a turbine wheel 4, a turbine housing 5, a shaft 6, a bearing 7, and a bearing housing 8. The turbocharger 1 is mounted on a vehicle such as an automobile.

[0011] The compressor wheel 2 compresses gas such as atmospheric air. The compressor housing 3 houses the compressor wheel 2 therein.

[0012] The turbine wheel 4 is rotationally driven by exhaust gas discharged from an engine (not shown). The turbine housing 5 accommodates the turbine wheel 4.

[0013] The shaft 6 connects the compressor wheel 2 and the turbine wheel 4. Therefore, the rotational driving force of the turbine wheel 4 is transmitted to the compressor wheel 2. The bearing 7 supports the shaft 6. The bearing housing 8 accommodates the shaft 6 and the bearing 7. The bearing housing 8 is disposed between the compressor housing 3 and the turbine housing 5.

[0014] Fig. 2 is a plan view that schematically shows the configuration of a portion of the turbocharger. As shown in Fig. 2, the turbocharger 1 further includes a variable nozzle unit 20, a drive lever 31, a drive shaft 32, a drive actuator 40, a rod 50, a link 60, and a stopper member 70. Note that the variable nozzle unit 20 and other components are omitted from Fig. 1.

[0015] The variable nozzle unit 20 is disposed inside the turbine housing 5. The variable nozzle unit 20 is capable of adjusting the size of the flow path area of ​​the exhaust flow path for exhaust gas. Specifically, the variable nozzle unit 20 has a pair of plates (not shown), a plurality of nozzle vanes 21, a plurality of vane arms 22, and a unison ring 23.

[0016] Each nozzle vane 21 is held by a pair of plates so as to be rotatable relative to the pair of plates. An exhaust flow passage is formed between the pair of plates. Each nozzle vane 21 is disposed between the pair of plates. Each nozzle vane 21 rotates around its rotary shaft 21a together with the rotary shaft 21a, thereby changing the size of the flow passage area of ​​the exhaust flow passage.

[0017] Each vane arm 22 is connected (for example, welded) to an end of each rotary shaft portion 21a. Each vane arm 22 rotates each rotary shaft portion 21a around its central axis.

[0018] The unison ring 23 is a member that rotates all of the vane arms 22 simultaneously around the respective rotary shaft portions 21a. The unison ring 23 is supported by a pair of plates so that it can rotate relatively around the central axis of the plates. Each vane arm 22 is engaged with the unison ring 23. Therefore, when the unison ring 23 rotates relative to the pair of plates, each vane arm 22 and the rotary shaft portion 21a rotate integrally around the central axis of the rotary shaft portion 21a. This changes the posture of each nozzle vane 21, thereby changing the flow path area of ​​the exhaust flow path.

[0019] The drive lever 31 is engaged with the unison ring 23. The drive lever 31 rotates the unison ring 23 around its central axis.

[0020] The drive shaft 32 is connected to the drive lever 31. The drive shaft 32 rotates together with the drive lever 31 around the central axis of the drive shaft 32. In other words, when the drive shaft 32 rotates, the unison ring 23 rotates via the drive lever 31, and the attitude of each nozzle vane 21 (the flow path area of ​​the exhaust flow path) changes.

[0021] The drive actuator 40 generates a rotational force that rotates the drive shaft 32. The drive actuator 40 is disposed at a position spaced apart from the drive shaft 32 in a direction perpendicular to the axial direction of the drive shaft 32. The drive actuator 40 has an actuator body 42 and an actuator lever 44.

[0022] The actuator body 42 has an output shaft 42a.

[0023] The actuator lever 44 is connected to the output shaft 42a and is rotatable around the output shaft 42a. The actuator lever 44 has a shaft connection portion 45 and a pin 46.

[0024] The shaft connecting portion 45 is connected to the output shaft 42a. The shaft connecting portion 45 is configured as a hole through which the output shaft 42a is inserted. The hole is shaped to prohibit relative rotation of the output shaft 42a with respect to the shaft connecting portion 45.

[0025] The pin 46 is provided at a position spaced apart from the output shaft 42a. The pin 46 extends in a direction parallel to the output shaft 42a. The pin 46 is formed in a cylindrical shape. The pin 46 is connected to a rod 50.

[0026] The rod 50 is connected to the drive actuator 40. The rod 50 constitutes part of a mechanism that transmits the rotational force of the drive actuator 40 to the variable nozzle unit 20. The rod 50 has an actuator side end 51 and a link side end 52.

[0027] The actuator side end 51 is configured as one end of the rod 50. The actuator side end 51 is connected to the actuator lever 44 so as to be rotatable relative to the actuator lever 44. Specifically, the actuator side end 51 is connected to the pin 46 of the actuator lever 44. The actuator side end 51 is configured as a hole through which the pin 46 is inserted.

[0028] The link side end 52 is formed at the other end of the rod 50. The link side end 52 is connected to the link 60 so as to be rotatable relative to the link 60. The link side end 52 is formed as a cylindrical protrusion.

[0029] The link 60 connects the rod 50 and the drive shaft 32. The link 60 constitutes part of a mechanism that transmits the rotational force of the drive actuator 40 to the variable nozzle unit 20. The link 60 is rotatable around the drive shaft 32 together with the drive shaft 32. Figure 3 is a plan view of the link. As shown in Figures 2 and 3, the link 60 has a drive shaft connecting portion 61 (see Figure 3), a rod connecting portion 62, and an abutment portion 63.

[0030] The drive shaft connecting portion 61 is connected to the drive shaft 32. The drive shaft connecting portion 61 is configured as a hole through which the drive shaft 32 is inserted. This hole is shaped to prohibit relative rotation of the drive shaft 32 with respect to the drive shaft connecting portion 61.

[0031] The rod connection portion 62 is connected to the link side end portion 52. The rod connection portion 62 is configured as a hole through which the link side end portion 52 is inserted.

[0032] The abutment portion 63 is the portion that abuts against the stopper member 70. It is set so that the opening degree of the variable nozzle unit 20 is smallest (fully closed) when the abutment portion 63 abuts against the stopper member 70. As the abutment portion 63 moves away from the stopper member 70 (in FIG. 2, the link 60 rotates counterclockwise around the drive shaft 32), the opening degree of the variable nozzle unit 20 gradually increases. The stopper member 70 is fixed to the bearing housing 8, for example.

[0033] At least one of the actuator lever 44, rod 50, and link 60 includes a change portion that can change the ratio of the length L2 (see FIG. 4) between the drive shaft 32 and the link side end 52 to the length L1 (see FIG. 4) between the output shaft 42a of the actuator body 42 and the actuator side end 51. Increasing the ratio of length L2 to length L1 decreases the flow characteristics (flow sensitivity) of the variable nozzle unit 20. Conversely, decreasing the ratio of length L2 to length L1 increases the flow characteristics (flow sensitivity) of the variable nozzle unit 20.

[0034] In addition, the length L1 between the output shaft 42a and the actuator side end 51 means the length between the center of the output shaft 42a and the center of the actuator side end 51, and the length L2 between the drive shaft 32 and the link side end 52 means the length between the center of the drive shaft 32 and the center of the link side end 52.

[0035] In this embodiment, the rod connection portion 62 of the link 60 constitutes the modified portion. As shown in Fig. 3, the rod connection portion 62 includes a plurality of connection portions 62a to 62c, each of which can be connected to the link-side end portion 52. In the example shown in Fig. 3, the rod connection portion 62 has three connection portions 62a to 62c. However, the number of connection portions is not limited to three.

[0036] The lengths between the connection portions 62a to 62c and the drive shaft connection portion 61 are different from one another. Specifically, the length between the connection portion 62b and the drive shaft connection portion 61 is longer than the length between the connection portion 62a and the drive shaft connection portion 61. The length between the connection portion 62c and the drive shaft connection portion 61 is shorter than the length between the connection portion 62a and the drive shaft connection portion 61.

[0037] For example, when the link side end 52 is connected to the connecting portion 62a, if it is desired to lower the flow characteristics (flow sensitivity) of the variable nozzle unit 20 when the link 60 moves away from the stopper member 70, the link side end 52 can be connected to the connecting portion 62b. Conversely, when the link side end 52 is connected to the connecting portion 62a, if it is desired to increase the flow characteristics (flow sensitivity) of the variable nozzle unit 20 when the link 60 moves away from the stopper member 70, the link side end 52 can be connected to the connecting portion 62c.

[0038] As described above, in the turbocharger 1 of this embodiment, the link 60 includes a changing portion, so it is possible to adjust the flow characteristics of the variable nozzle unit 20 by changing the ratio of the length L2 between the drive shaft 32 and the link-side end 52 to the length L1 between the output shaft 42a and the actuator-side end 51. This makes it possible to reduce variations in the flow characteristics in the region where the nozzle vanes 21 of the variable nozzle unit 20 have a large opening.

[0039] Modifications of the above embodiment will be described below. The configurations of the following modifications can also be applied to the above embodiment in addition to the above embodiment.

[0040] <First Modification> 5, the actuator-side end 51 may constitute the variable portion. The actuator-side end 51 includes a plurality of connection portions 51a to 51c, each of which can be connected to the pin 46 of the actuator lever 44. The lengths between the connection portions 51a to 51c and the link-side end 52 are different from one another.

[0041] <Second Modification> 6, the variable portion may be formed by the shaft connection portion 45 of the actuator lever 44. The shaft connection portion 45 includes a plurality of connection portions 45a to 45c, each of which is connectable to the output shaft 42a of the actuator body 42. The lengths between the pin 46 and each of the connection portions 45a to 45c are different from one another.

[0042] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0043] [Aspect 1] A turbine wheel; a variable nozzle unit capable of adjusting the size of a flow path area of ​​an exhaust gas flow path; a drive lever that drives the variable nozzle unit; a drive shaft connected to the drive lever, the drive shaft rotating together with the drive lever around a central axis of the drive shaft; a drive actuator for driving the variable nozzle unit; a rod connected to the drive actuator; a link connecting the rod and the drive shaft, The drive actuator is an actuator body having an output shaft; an actuator lever connected to the output shaft and rotatable around the output shaft, The rod is an actuator side end portion connected to the actuator lever so as to be rotatable relative to the actuator lever; a link-side end portion connected to the link so as to be rotatable relative to the link; The link is: a drive shaft connection portion connected to the drive shaft; a rod connection portion connected to the link side end portion, A turbocharger, wherein at least one of the actuator lever, the rod, and the link includes a change portion that can change the ratio of the length between the drive shaft and the link side end to the length between the output shaft and the actuator side end of the actuator body.

[0044] In this turbocharger, at least one of the actuator lever, rod, and link includes a variable portion, so that the flow characteristics of the nozzle unit can be adjusted by changing the ratio of the length between the drive shaft and the link end to the length between the output shaft and the actuator end of the actuator body, thereby reducing variations in the flow characteristics in the large opening range of the variable nozzle unit.

[0045] [Aspect 2] The rod connection portion constitutes the change portion, the rod connection portion includes a plurality of connection portions each connectable to the link-side end portion, A turbocharger according to aspect 1, wherein lengths between each of the plurality of connection portions and the drive shaft connection portion are different from one another.

[0046] [Aspect 3] the actuator-side end portion constitutes the change portion, the actuator side end portion includes a plurality of connection portions each connectable to the actuator lever, A turbocharger according to aspect 1 or 2, wherein lengths between each of the plurality of connection portions and the link-side end portion are different from one another.

[0047] [Aspect 4] The actuator lever a shaft connection portion connected to the output shaft; a pin connected to the actuator side end, the shaft connection portion constitutes the change portion, the shaft connection portion includes a plurality of connection portions each connectable to the output shaft of the actuator body, A turbocharger according to any one of aspects 1 to 3, wherein lengths between each of the plurality of connection portions and the pin are different from one another.

[0048] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0049] 1 turbocharger, 2 compressor wheel, 3 compressor housing, 4 turbine wheel, 5 turbine housing, 6 shaft, 7 bearing, 8 bearing housing, 20 variable nozzle unit, 21 nozzle vane, 22 vane arm, 23 unison ring, 31 drive lever, 32 drive shaft, 40 drive actuator, 42 actuator body, 42a output shaft, 44 actuator lever, 45 shaft connection portion, 46 pin, 50 rod, 51 actuator side end (modified portion), 52 link side end, 60 link, 61 drive shaft connection portion, 62 rod connection portion (modified portion), 63 abutment portion, 70 stopper member.

Claims

1. A turbine wheel; a variable nozzle unit capable of adjusting the size of a flow path area of ​​an exhaust gas flow path; a drive lever that drives the variable nozzle unit; a drive shaft connected to the drive lever, the drive shaft rotating together with the drive lever around a central axis of the drive shaft; a drive actuator for driving the variable nozzle unit; a rod connected to the drive actuator; a link connecting the rod and the drive shaft, The drive actuator is an actuator body having an output shaft; an actuator lever connected to the output shaft and rotatable around the output shaft, The rod is an actuator side end portion connected to the actuator lever so as to be rotatable relative to the actuator lever; a link-side end portion connected to the link so as to be rotatable relative to the link; The link is: a drive shaft connection portion connected to the drive shaft; a rod connection portion connected to the link side end portion, A turbocharger, wherein at least one of the actuator lever, the rod, and the link includes a change portion that can change the ratio of the length between the drive shaft and the link side end to the length between the output shaft and the actuator side end of the actuator body.

2. The rod connection portion constitutes the change portion, the rod connection portion includes a plurality of connection portions each connectable to the link-side end portion, The turbocharger according to claim 1 , wherein lengths between each of the plurality of connection portions and the drive shaft connection portion are different from one another.

3. the actuator-side end portion constitutes the change portion, the actuator side end portion includes a plurality of connection portions each connectable to the actuator lever, The turbocharger according to claim 1 , wherein lengths between each of the plurality of connection portions and the link-side end portion are different from one another.

4. The actuator lever a shaft connection portion connected to the output shaft; a pin connected to the actuator side end, the shaft connection portion constitutes the change portion, the shaft connection portion includes a plurality of connection portions each connectable to the output shaft of the actuator body, The turbocharger according to claim 1 , wherein lengths between each of the plurality of connection portions and the pin are different from one another.

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