JP2008185019A - Variable turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable turbocharger capable of easily coping with different mounting style and preventing component management from being complicated. <P>SOLUTION: The variable turbocharger 1 includes a center housing 7 supporting a turbo shaft 6 and is provided with a slide mechanism 20 as a nozzle opening adjusting mechanism adjusting nozzle opening and a hydraulic servo drive device 30 as a drive device driving a drive shaft 21 of the slide mechanism 20. The center housing 7 is provided with a pair of mounting surfaces 130A, 130B which are provided on opposing positions with the turbo shaft 6 put therebetween and on which the hydraulic servo drive device 30 is mounted, and an insertion through hole 119 which penetrates the mounting surfaces 130A, 130B and through which the drive shaft 21 is inserted. The hydraulic servo drive device 30 is mounted on either of the pair of mounting surfaces 130A, 130B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable turbocharger, and more particularly to an attachment structure for an actuator that drives a variable turbo.

  2. Description of the Related Art Conventionally, there is known a variable turbocharger that can adjust an opening area of a nozzle portion that ejects exhaust gas to an exhaust turbine (Patent Document 1). According to this variable turbocharger, in the low-speed rotation region of an engine with a small amount of exhaust gas, the opening area can be reduced by narrowing the gap between the exhaust introduction walls forming the nozzle portion. Since the flow velocity of the exhaust gas flowing into the exhaust turbine increases, the rotational energy of the turbine wheel increases, and the supercharging capability of the air supply compressor can be increased.

  On the other hand, it is known that not only the variable turbocharger but also the use of a turbocharger complicates the handling of the exhaust pipe and the intake pipe (Patent Document 2). FIG. 11 is a perspective view of an engine with a turbocharger disclosed in Patent Document 2. FIG. In this figure, two turbochargers 140 and 141, large and small, are used, but there is no difference in complexity even when there is only one turbocharger.

  Especially when a variable turbocharger is used as a turbocharger, an adjustment mechanism for adjusting the opening area of the nozzle portion is provided inside the variable turbocharger, and a drive device for driving the adjustment mechanism is required. However, since such a drive device is attached to the outside of the housing constituting the variable turbocharger by means of bolts or the like, the arrangement space with other parts is generated, and the arrangement of the parts is further complicated. In addition, as shown in FIG. 11, when an EGR (Exhaust Gas Recirculation) device 142 is provided, an EGR pipe 143 for returning a part of the exhaust gas from the exhaust pipe to the intake pipe, an EGR valve 144, Since the EGR cooler 145 and the like are provided, it becomes more complicated.

Japanese Patent Laid-Open No. 11-72008 JP 2006-70878 A

  By the way, even when using a variable turbocharger with the same capacity, depending on the engine specifications and the specifications of the vehicle on which the engine is mounted, the arrangement of parts, such as the routing of piping around the engine, may vary. As a result, the mounting direction or mounting position of the variable turbocharger with respect to the engine body may be varied. In particular, when the direction of the variable turbocharger with respect to the engine is reversed, if the mounting position of the drive device with respect to the housing in the variable turbocharger is uniform, it will interfere with other parts or dissipate heat from the exhaust manifold. There is a problem of being affected. Therefore, for the variable turbocharger, it is necessary to change the mounting position of the drive device with respect to the housing according to each specification.

  However, if a variable turbocharger with a different mounting position of the drive unit relative to the housing was designed exclusively for each specification, the number of types of variable turbochargers increased, and each component such as a housing It is necessary to prepare a plurality of types according to the specifications, and parts management becomes complicated when manufacturing a variable turbocharger.

  An object of the present invention is to provide a variable turbocharger that can easily cope with different mounting forms and can prevent complication of parts management.

  A variable turbocharger according to a first aspect of the present invention includes a center housing that supports a turbo shaft, a nozzle opening adjusting mechanism that adjusts the nozzle opening, and a drive shaft of the nozzle opening adjusting mechanism. The center housing is provided at a position opposite to the turbo shaft so that the drive device is attached to the center housing, and the drive shaft is inserted through the attachment surfaces. The drive device is attached to any one of the pair of attachment surfaces.

  The variable turbocharger according to claim 2 of the present invention is the variable turbocharger according to claim 1, wherein bushes into which the drive shaft is inserted are respectively provided on both sides of the insertion hole, The assembling dimensions from each mounting surface to the outer side end of the bush close to the mounting surface are the same.

  A variable turbocharger according to a third aspect is the variable turbocharger according to the first or second aspect, wherein the nozzle opening adjustment mechanism is a link mechanism, and the drive device is a hydraulic servo drive. It is a device.

  In the above, according to the first aspect of the present invention, since the mounting surfaces of the drive device are provided on the opposite sides of the center housing, even if the position or orientation of the variable turbocharger changes depending on the engine specifications, the engine The mounting surface on the superior side can be selected in consideration of the connection with the surrounding parts, and the drive device can be easily mounted on the turbo body. Moreover, even when the drive device is mounted on any mounting surface side, by using a configuration in which components such as a drive shaft driven by the drive device are used in common, there is no fear of increasing the types of components, and complicated component management is required. There is no risk of instability.

  According to the second aspect of the present invention, since the pair of bushes are arranged in advance in the insertion hole of the center housing with the same mounting dimension from each mounting surface, the drive shaft is fitted in accordance with the mounting position of the driving device. The drive shaft can be reliably supported by each bush even when inserted from either side.

  According to the third aspect of the present invention, since the nozzle opening degree adjusting mechanism constituted by the link mechanism is hydraulically driven by the hydraulic servo drive device, it can be driven more precisely with a larger driving force. Therefore, even if the length of the part functioning as a lever in the link mechanism is shortened, the nozzle opening degree adjusting mechanism can be driven reliably, and by shortening the part, the nozzle opening degree adjusting mechanism and thus the variable turbocharger can be driven. Can be downsized.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a variable turbocharger 1 according to this embodiment. 2 and 3 are a sectional view taken along line II-II and a sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. Although an illustration of the engine on which the variable turbocharger 1 is mounted is omitted, an engine with an EGR device with a complicated arrangement of parts is assumed.

  In FIG. 1, the variable turbocharger 1 is configured to include a turbine on the right side and a compressor on the left side in the drawing, and is provided in an unillustrated engine body. A turbine wheel 3 is accommodated in the turbine housing 2 on the turbine side, and a compressor impeller 5 is accommodated in the compressor housing 4 on the compressor side. The turbine wheel 3 is integrally provided with a turbo shaft 6, and a compressor impeller 5 is attached to the tip of the turbo shaft 6. Therefore, the rotation of the turbine wheel 3 rotated by the exhaust gas is transmitted to the compressor impeller 5 through the turbo shaft 6, and the intake air is compressed and supercharged by the rotation of the compressor impeller 5.

  The turbine housing 2 is provided with a volute-like exhaust introduction path 10 for introducing exhaust gas from the engine body. In the exhaust introduction path 10, a nozzle portion 11 for ejecting exhaust gas to the turbine wheel 3 side is continuously provided in the circumferential direction, and the exhaust gas ejected from the nozzle portion 11 rotates the turbine wheel 3. Later, the air is exhausted from the exhaust outlet 12. The nozzle portion 11 is formed by a pair of exhaust introduction walls 13 and 14 that face each other.

  One exhaust introduction wall 13 is formed by a side surface 16 of a movable ring 15 having a U-shaped cross section and an annular shape. The movable ring 15 is accommodated in an annular accommodating portion 8 provided in the center housing 7. A plurality of nozzle vanes 17 protruding toward the other exhaust introduction wall 14 are attached to the side surface 16 of the movable ring 15 at equal circumferential intervals. The exhaust introduction wall 14 is provided with a recess 18 that is continuous in the circumferential direction, and the tip side of each nozzle vane 17 is accommodated in the recess 18. In such a structure, by moving the movable ring 15 forward and backward by a slide mechanism 20 (see FIG. 2) described later, the exhaust introduction wall 13 is moved closer to and away from the exhaust introduction wall 14 and the opening area of the nozzle portion 11 is increased. change.

  A bearing portion 110 that supports the turbo shaft 6 is provided inside the center housing 7, and the turbo shaft 6 is inserted and supported in the bearing portion 110 via a journal bearing 111. Further, an oil inflow portion 112 for taking in oil from the engine body side is provided above the bearing portion 110 in the drawing. Part of the oil that has flowed into the oil inflow portion 112 is supplied from the branch flow passage 114 into the bearing portion 110 through the internal flow passage 113 in the center housing 7, and the rotating portion of the turboshaft 6 is lubricated. The oil flows out from the outflow part 116 of the part 110 to the oil return chamber 117 in the center housing 7. The other part lubricates the compressor-side thrust bearing 115 and then flows down into the oil return chamber 117 below. The oil that has flowed down into the oil return chamber 117 is drained to the engine body from the return port 118 provided at the bottom of the center housing 7.

  The configuration on the compressor side is the same as that of a normal turbocharger, and is well known, so detailed description thereof is omitted here. Hereinafter, the slide mechanism 20 as the nozzle opening degree adjusting mechanism will be described in detail.

  The slide mechanism 20 has a structure for moving the above-described movable ring 15 forward and backward by rotationally driving a drive shaft 21 inserted through the lower side of the center housing 7. The principal part of such a slide mechanism 20 is shown by FIGS. 2 to 4, a yoke 22 (see FIG. 3) extending in an arc shape upward is fixed at a midway position of the drive shaft 21 with a bolt 22 </ b> A. Pins 23 that protrude outward in the horizontal direction are attached to both ends of the yoke 22, and sliders 24 are fitted into the pins 23. The slider 24 is slidably fitted in a sliding groove 26 on the base end side of the support rod 25 parallel to the turbo shaft 6 described above. The tip of the support rod 25 is fixed to the back side of the movable ring 15.

  Therefore, when the drive shaft 21 is rotated, the yoke 22 swings along the axial direction of the turboshaft 6, so that the support rod 25 moves and moves the movable ring 15, and one exhaust introduction wall 13 moves to the other. It advances and retreats with respect to the exhaust introduction wall 14. In such a slide mechanism 20, the support rod 25 having the yoke 22, the pin 23, the slider 24, and the sliding groove 26 converts the rotational movement of the drive shaft 21 into the forward / backward movement of the exhaust introduction wall 13. Means.

  The drive shaft 21 of the slide mechanism 20 is rotationally driven by a hydraulic servo drive device 30 via a lever 27 provided at the end thereof. Hereinafter, the hydraulic servo drive device 30 will be described in detail.

  As shown in FIGS. 3 to 5, the hydraulic servo drive device 30 basically has a structure for rotating the drive shaft 21 by moving the servo piston 31 up and down. For this purpose, a sliding groove 32 perpendicular to the axial direction is provided on the outer periphery of the servo piston 31, and a pin 28 protruding toward the sliding groove 32 is provided on the lever 27 on the drive shaft 21 side. A slider 29 is fitted into the pin 28, and the slider 29 is slidably fitted into the sliding groove 32.

  That is, in the present embodiment, another conversion means that includes the sliding groove 32, the slider 29, the pin 28, and the lever 27 and converts the advance / retreat movement of the servo piston 31 into the rotation movement of the drive shaft 21 is configured. . When the servo piston 31 is moved up and down, the slider 29 moves up and down along with it and slides along the slide groove 32. The movement of the slider 29 and the rotation of the pin 28 allow the lever 27 to move in an arc. The lever 27 can be rotated.

  The conversion means and the conversion means in the center housing 7 are both link mechanisms, and the entire slide adjustment mechanism 20 is constituted by a link mechanism. Since such a link mechanism is driven by a large driving force of the hydraulic servo drive device 30 that operates with pressure oil, the length of the lever 27 in the link mechanism and the length of the arm portion of the yoke 22 are shortened. However, the slide mechanism 20 can be reliably driven, the slide mechanism 20 can be made compact, and the variable turbocharger 1 can be reduced in size.

  Here, the lever 27 side of the drive shaft 21 is accommodated in an oil reservoir chamber 33 </ b> B provided in the housing 33 of the hydraulic servo drive device 30. The oil reservoir chamber 33B is a chamber in which the pressure oil used for the operation of the servo piston 31 is discharged and accumulated, and continuously in the circumferential direction of the housing 33 so as to surround the outer periphery of the servo piston 31 with a predetermined width. Is formed.

  The oil reservoir chamber 33 </ b> B and the oil return chamber 117 in the center housing 7 communicate with each other through a drain channel 7 </ b> A formed in the center housing 7. That is, one end side of the drain flow path 7A opens to the oil reservoir chamber 33B, and the other end side opens to the oil return chamber 117. Accordingly, the pressure oil that has flowed into the oil reservoir 33B flows out into the center housing 7 through the drain passage 7A, passes through the drain circuit 75 (see FIG. 9) from the return port 118, and is drained to the engine body. . The drain flow path 7A is provided to return the pressure oil from the oil reservoir 33B through the turbo body, but is easy to process and has a high degree of design freedom such as the flow path diameter. There is a merit.

  Further, the drive shaft 21 enters the oil reservoir 33B through the opening 33A. The drive shaft 21 is inserted through an insertion hole 119 provided in the center housing 7. Bushings 120 are disposed at both ends (only one end side is shown in FIG. 4) in the insertion hole 119, and both sides of the drive shaft 21 are supported while passing through these bushings 120. While the bush 120 is press-fitted into the insertion hole 119, a gap is formed between the bush 120 and the drive shaft 21 to the extent that an oil film is formed. That is, since this gap functions as another drain channel 21B, the pressure oil in the oil reservoir chamber 33B flows to the center housing 7 side even through the drain channel 21B, so that the periphery of the drive shaft 21 is improved. Can be lubricated.

  FIG. 6 shows a longitudinal section of the entire hydraulic servo drive device 30. In FIG. 6, the hydraulic servo drive device 30 includes the servo piston 31, the housing 33 that slidably accommodates the servo piston 31, and partly having an opening 33 </ b> A, and the axial direction of the servo piston 31. And a pilot spool 36 which is accommodated in the center hole 34 penetrating through and is slid by the pilot pressure, and is attached to the center housing 7 of the variable turbocharger 1 via an O-ring 100 which seals around the opening 33A. ing.

  First, a cylindrical cylinder 35 penetrating vertically is provided inside the housing 33, and the servo piston 31 is accommodated in the cylinder 35. The upper and lower ends of the cylinder 35 are sealed by closing members 37 and 38 via O-rings 101 and 102. A connection portion 39 between the drive shaft 21 and the servo piston 31 is provided at a position corresponding to the opening portion 33 </ b> A of the housing 33. Accordingly, the sizes of the opening 33A and the oil reservoir 33B are set in consideration of the sliding amount of the servo piston 31 and the slider 29, the flow rate of the discharged pressure oil, and the like.

  On the side surface of the housing 33 opposite to the opening 33A, for example, a pilot port 41 for supplying pilot pressure from a proportional solenoid valve 95 (FIG. 9) located away from the variable turbocharger 1, a booster pump A pump port 42 for supplying pressure oil from 92 (FIG. 9) is provided. The booster pump 92 and the proportional solenoid valve 95 are installed in the same engine body (not shown) on which the variable turbocharger 1 of the present embodiment is mounted.

  In the cylinder 35 of the housing 33, a part where the servo piston 31 slides and a part above the part are partitioned by a partition member 44. The partition member 44 is in contact with a stepped portion provided on the inner peripheral surface of the cylinder 35, and an O-ring 103 for sealing a portion partitioned by the partition member 44 is provided in the vicinity of the contact portion. It has been. The partition member 44 is provided with a cylindrical portion 45 that hangs downward. The cylindrical portion 45 enters the upper side of the center hole 34 of the servo piston 31. The upper chamber partitioned by the partition member 44 is a pilot hydraulic chamber 46, and the pilot hydraulic chamber 46 and the pilot port 41 communicate with each other.

  On the other hand, the lower chamber partitioned by the partition member 44 is a first hydraulic chamber 47 formed between the partition member 44 and the upper end surface of the servo piston 31. In other words, the pilot hydraulic chamber 46 is displaced axially outward (upward in this embodiment) with respect to the first hydraulic chamber 47, and this arrangement increases the diameter of the entire hydraulic servo drive device 30. Is suppressed. Further, a second hydraulic chamber 48 is formed between the lower end surface of the servo piston 31 and the lower closing member 38.

  Next, the servo piston 31 will be described. The servo piston 31 is provided with a pressure port 51 that allows the center hole 34 and the pump port 42 of the housing 33 to communicate with each other and allows pressure oil from the pump to flow into the center hole 34. The outside of the pressure port 51 is open to a groove portion formed to face in the radial direction, and the groove portion has a predetermined vertical dimension, so that the pressure port 51 and the pump port are within the stroke of the servo piston 31. 42 always communicates.

  Further, the servo piston 31 is provided with a return port 52 that allows the center hole 34 and the oil reservoir chamber 33B of the housing 33 to communicate with each other and allows the pressure oil in the center hole 34 to flow into the center housing 7 of the turbo body. Yes. The outside of the return port 52 opens in a groove formed on the outer periphery of the servo piston 31, and the return port 52 and the oil reservoir 33B are always in communication with each other within the stroke of the servo piston 31. Further, in the present embodiment, the return port 52 is provided so as to penetrate the servo piston 31 in the radial direction, and a part of the drained pressure oil remains as it is from the sliding groove 32 side in which the slider 29 is fitted. It flows out to the reservoir 33B.

  In addition to the servo piston 31, as indicated by a dotted line in FIG. 6, a first piston port 53 that connects the center hole 34 and the upper first hydraulic chamber 47 and a second hydraulic chamber below the center hole 34. A second piston port 54 for communicating with 48 is provided. At this time, the opening portion on the center hole 34 side of the first piston port 53 is positioned below the opening portion of the pressure port 51, and the opening portion on the center hole 34 side of the second piston port 54 is located on the pressure port 51. It is located above the opening. The first and second piston ports 53 and 54 are provided so as to be shifted to positions that do not communicate with the pressure port 51 and the return port 52, respectively.

  The lower side of the center hole 34 is hermetically sealed by screwing the contact member 55 to the servo piston 31 via the O-ring 104, and the servo piston 31 contacts the closing member 38 via the contact member 55. The contacted and contacted position is the lowest position of the servo piston 31. In the second hydraulic chamber 48, a coil spring 56 is disposed between the closing member 38 and the contact member 55 to assist the upward movement of the servo piston 31. Even when there is no pressure oil in the pipe connected to the hydraulic servo drive device 30 due to a failure of the booster pump 92, the nozzle opening of the variable turbocharger 1 is opened by the spring force of the coil spring 56 (preferably fully open). ) To be maintained.

  The pilot spool 36 includes two first and second spool lands 61 and 62 at a substantially central portion. A return flow path 63 that opens downward is provided inside the pilot spool 36, and the upper groove portion of the first spool land 61 communicates with the return flow path 63, and the lower side of the second spool land 62 Similarly, the groove portion and the return flow path 63 communicate with each other. Furthermore, since the lower side of the return flow path 63 is opened, the return flow path 63, the return port 52, and the oil reservoir chamber 33B communicate with each other.

  The pilot spool 36 can slide up and down in the center hole 34 of the servo piston 31 through the cylindrical portion 45 of the partition member 44, and the upper end portion of the pilot spool 36 is screwed into a holding member 64 disposed in the pilot hydraulic chamber 46. Are held together. In the pilot hydraulic chamber 46, the holding member 64 is urged upward by a coil spring 65, and the pilot spool 36 moves downward by the pilot pressure against the urging force of the coil spring 65, so that the pilot pressure oil returns ( Although not shown, the drain flow path is moved upward by the biasing force of the coil spring 65 by being drained to the oil pan 80 on the electromagnetic valve 95 side.

  In the hydraulic servo drive device 30 having such a configuration, when the pilot spool 36 rises with respect to the servo piston 31, the servo piston 31 rises accordingly, and when the pilot spool 36 descends, the servo piston 31 follows. Descend. At this time, since the pilot spool 36 only slides in the axial direction within the servo piston 31, the driving load when the movable ring 15 advances and retreats acts on the servo piston 31 via the slide mechanism 20. It does not act on the spool 36 at all.

  For this reason, in this embodiment, the position of the pilot spool 36 is controlled, and thus the position of the servo piston 31 is controlled, and the movable ring 15 is moved forward and backward to change the opening area of the nozzle portion 11. The position control of the pilot spool 36 can be performed regardless of the driving load, and load drift can be eliminated. Therefore, even in the case of an exhaust turbo whose fluid pressure due to exhaust gas is not constant, that is, the variable turbocharger 1 as in this embodiment, the opening area of the nozzle portion 11 can be easily controlled, and the emission can be accurately controlled. . Further, since the position control can be performed accurately, the response time can be shortened by changing the control method from feedback control to feedforward control, for example, and it is possible to cope with transients with high accuracy.

  Next, the movement of the hydraulic servo drive device 30 will be specifically described with reference to FIGS. In FIG. 6, the pilot pressure exceeding the urging force of the coil spring 65 is supplied, so that both the pilot spool 36 and the servo piston 31 are in the lowest position. Therefore, in this state, the lower end of the pilot spool 36 is in contact with the upper end of the contact member 55, and the lower end of the contact member 55 is in contact with the closing member 38. Further, at this position, the first spool land 61 on the upper side of the pilot spool 36 is shifted downward from the second piston port 54, the second piston port 54 communicates with the return port 52 through the return flow path 63, and the second The pressure oil in the hydraulic chamber 48 is drained.

  On the other hand, the lower second spool land 62 is also shifted downward with respect to the first piston port 53, and the pressure port 51 and the first piston port 53 communicate with each other. For this reason, pressure oil is supplied to the first hydraulic chamber 47 through the pressure port 51 and the first piston port 53.

  A part of the pressure oil supplied to the pilot hydraulic chamber 46 may be a slight gap formed between the cylindrical portion 45 of the partition member 44 and the holding member 64 or the upper end of the cylindrical portion 45 and the pilot spool 36. A portion defined below through a slight gap formed between the outer peripheral portion, that is, the inner periphery of the center hole 34 of the servo piston 31, the outer periphery of the pilot spool 36, and the lower end of the cylindrical portion 45 Enter the part that is partitioned by.

  From this state, as shown in FIG. 7, when the pressure oil in the pilot hydraulic chamber 46 is returned and lowered to a predetermined pilot pressure, the pilot spool 36 rises to a position where the pilot pressure and the coil spring 65 are balanced. At this time, since the upper first spool land 61 is displaced above the second piston port 54, the second piston port 54 and the pressure port 51 communicate with each other, and pressure oil is supplied to the second hydraulic chamber 48.

  At the same time, the lower second spool land 62 is also displaced above the first piston port 53, so that the first piston port 53 and the return flow path 63 communicate with each other, and the pressure oil in the first hydraulic chamber 47 is removed. A part is drained, so that the servo piston 31 rises so as to follow the pilot spool 36. The raising of the servo piston 31 ends when the first and second piston ports 53 and 54 are closed by the first and second spool lands 61 and 62, and the servo piston 31 corresponds to the stop position of the pilot spool 36. Stop at the same position. The servo piston 31 does not rise over the pilot spool 36.

  Subsequently, as shown in FIG. 8, in the state where the pilot pressure is completely released, the pilot spool 36 moves upward until the upper end of the holding member 64 comes into contact with the top surface of the pilot hydraulic chamber 46, The servo piston 31 following this movement rises until the upper end comes into contact with the partition member 44. In this state, the pilot spool 36 and the servo piston 31 are both in the uppermost position, and the first and second piston ports 53 and 54 are respectively in the first pressure oil chamber 48 filled with the pressure oil. The second spool lands 61 and 62 are closed. The pressure oil in the first pressure oil chamber 47 is discharged from the return port 52 to the oil reservoir chamber 33 </ b> B, and the drain flow formed by the drain passage 7 </ b> A provided in the center housing 7 and the gap around the drive shaft 21. The oil flows out into the oil return chamber 117 of the center housing 7 through the path 21B, and is drained to the oil pan 80 of the engine body from here.

  At this time, the pressure oil that has entered the portion defined by the inner periphery of the center hole 34 of the servo piston 31, the outer periphery of the pilot spool 36, and the lower end of the cylindrical portion 45 returns to the pilot hydraulic chamber 46 through the aforementioned gap. It will be.

  When the servo piston 31 is moved to a predetermined position below, a pilot pressure is supplied to lower the pilot spool 36 to a predetermined position. By doing so, the second piston port 54 communicates with the return flow path 63 again, a part of the pressure oil in the second hydraulic chamber 48 is drained, and the servo piston 31 is lowered. This descent is finished when the first and second piston ports 53 and 54 are closed by the first and second spool lands 61 and 62, and the servo piston 31 is at a position corresponding to the stop position of the pilot spool 36. Similarly stop. Of course, the servo piston 31 does not descend over the pilot spool 36. Then, after the pressure oil in the second pressure oil chamber 48 flows out from the return port 52 to the oil reservoir chamber 33B, it flows to the oil return chamber 117 through the drain passages 7A and 21B, and from there to the engine body. Is done.

  According to the hydraulic servo drive device 30 performing the above operation, the pressure oil drained with the operation of the servo piston 31 is drained through the turbo body while lubricating the periphery of the drive shaft 21. In addition to preventing seizure and abrasion, the durability of the bush 120 can be improved. Further, since a drain circuit that directly communicates with each other is not required between the hydraulic servo drive device 30 and the oil pan 80, the piping for the hydraulic circuit in a narrow engine room such as a construction machine can be routed. Easy to do.

  FIG. 9 schematically shows an engine lubrication circuit 70 in which the variable turbocharger 1 of the present embodiment is mounted. The lubrication circuit 70 is configured to pump the lubricating oil in the oil pan 80 with a hydraulic pump 81 and supply it to the main gallery 84 via an oil cooler 82 and an oil filter 83. With the lubricating oil from the main gallery 84, the crankshaft 85 and the camshaft 86 are mainly lubricated.

  Also, the lubrication circuit 70 is branched from the main gallery 84 to inject an injector side circuit 71 that lubricates the cam drive unit and the like in the fuel injector 87, and a transmission mechanism side that lubricates a power transmission mechanism 88 including a timing gear. A circuit 72, a rocker arm side circuit 73 that lubricates the rocker arm 89, a turbocharger side circuit 74 that lubricates the bearing 110 that supports the turbo shaft 6 of the variable turbocharger 1, the variable turbocharger 1 and fuel A drain circuit 75 for returning the lubricating oil from the injection device 87 to the oil pan 80 is provided. Furthermore, in the present embodiment, a pressure oil supply circuit 90 that supplies a part of the lubricating oil to the hydraulic servo drive device 30 as drive pressure oil is provided separately from the lubrication circuit 70, and the oil of the hydraulic servo drive device 30 is provided. As described above, the drain flow paths 7A and 21B for flowing the pressure oil from the reservoir chamber 33B to the turbo main body are provided. The drain flow paths 7A and 21B join the drain circuit 75.

  That is, in this embodiment, the pressure oil for driving the hydraulic servo drive device 30 is covered by part of the engine lubricating oil, but the circuit for supplying the pressure oil is branched from the front of the main gallery 84. This is a pressure oil supply circuit 90. A booster pump 92 is provided on the proximal end side of the pressure oil supply circuit 90, and the pressurized pressure oil is supplied to the pump port 42 of the hydraulic servo drive device 30 through the drive pressure circuit 93 on the distal end side. The discharge pressure at the hydraulic pump 81 is about 196 to 294 kN / m @ 2 (2 to 3 kg / cm @ 2), and the discharge pressure after boosting by the booster pump 92 is about 1470 kN / m @ 2 (15 kg / cm @ 2).

  The leading end side of the pressure oil supply circuit 90 is branched into the drive pressure circuit 93 supplied to the pump port 42 side and a pilot pressure circuit 94 that supplies pilot pressure to the pilot port 41 of the hydraulic servo drive device 30. For this reason, the pilot pressure circuit 94 is provided with a proportional solenoid valve 95 that generates a pilot pressure. By applying a predetermined current to the solenoid valve 95, a pilot pressure of 0 to 1470 kN / m 2 (0 to 15 kg / cm 2) corresponding to the current is generated, and the pilot spool 36 is moved to a position corresponding to the pilot pressure. Is possible.

  Although illustration is omitted, a water cooling circuit is also connected to the turbo body, and the turbo main body is cooled by cooling water flowing through the water cooling circuit. Further, in FIG. 9, the end on the return side of the drain circuit 75 is illustrated as being connected to the oil pan 80. However, in reality, the drain circuit 75 is connected to the engine body, and the oil is passed through the engine body. Returns to the oil pan 80.

  By the way, in the center housing 7 of the variable turbocharger 1 in this embodiment, as shown in FIGS. 3 and 4, an attachment surface 130 for attaching the hydraulic servo drive device 30 sandwiches the turbo shaft 6. They are provided on the left and right respectively. When the mounting direction or mounting position of the variable turbocharger 1 with respect to the engine body differs depending on the specifications of the engine, etc., consider the routing of the piping in the mounting form or the placement position of other parts, and the appropriate side The hydraulic servo drive device 30 is attached to the attachment surface 130 (130A, 130B) (see the two-dot chain line in the figure).

  In FIG. 3, the hydraulic servo drive device 30 is configured to rotate the drive shaft 21, but the insertion holes 119 for inserting the drive shaft 21 pass through the mounting surfaces 130 </ b> A and 130 </ b> B on both sides. Is provided. The insertion holes 119 that also penetrate the oil return chamber 117 of the center housing 7 have bearing portions 131 on both sides thereof, and the bush 120 described above is press-fitted into each bearing portion 131. At this time, only one side is shown in FIG. 4, but the length dimension L1 of the bearing 131 on both sides is the same. In addition, the same length L2 is used as the bush 120 in each bearing portion 131, and the mounting dimension from each mounting surface 130A, 130B to the outer end of the bush 120 adjacent to the mounting surface 130A, 130B. F is also the same, and the bush 120 is disposed in a symmetrical position.

  The drain channels 7A (see FIG. 3) described above are also provided at the left and right symmetrical positions of the mounting surfaces 130A and 130B, respectively. When the hydraulic servo drive device 30 is attached to one attachment surface 130A (130B), the drain channel 7A and the end of the insertion hole 119 opened to the other attachment surface 130B (130A) are plugs 132 or appropriate seals. It is blocked by a stop member 133 so that oil does not leak out.

  Further, a water jacket 134 (see FIGS. 1 and 2) into which cooling water for water cooling flows is formed in the center housing 7. An inflow port (not shown) for the cooling water is provided at the lower portion of the center housing 7, and an outflow port 136 is opened at the upper portion of the center housing 7.

  In the side view of the center housing 7 shown in FIG. 10, reference numeral 137 denotes a bolt hole for mounting the hydraulic servo drive device 30, and reference numeral 138 denotes a knock pin for positioning the hydraulic servo drive device 301 with respect to the center housing 7. It is. Although illustration of the attachment surface 130B in a front view is omitted, the attachment surface 130B is also provided with a bolt hole 137 and a knock pin 138 at symmetrical positions with respect to the attachment surface 130A. That is, the shapes of the mounting surfaces 130A and 130B are provided symmetrically (line symmetric) about the axis of the turbo shaft 6.

  Here, even when the hydraulic servo drive device 30 is attached to either of the attachment surfaces 130A and 130B, the same hydraulic servo drive device 30 and the drive shaft 21 are used. In other words, when the hydraulic servo drive device 30 is attached to the attachment surface 130A, for example, the drive shaft 21 is inserted from the attachment surface 130A side as shown in FIG. Facing side) faces the turbine side. On the other hand, in the case where the hydraulic servo drive device 30 is attached to the attachment surface 130B, although not shown, the drive shaft 21 is inserted from the attachment surface 130B side, but the tip side of the lever 27 is also directed toward the turbine side. Become.

  By doing this, the drive shaft 21 can always be rotated in the direction of arrow A in FIG. 10 by raising the servo piston 31, and the yoke 22 can be tilted toward the compressor to increase the nozzle opening. Conversely, by lowering the servo piston 31, the drive shaft 21 can always be rotated in the direction of arrow B, and the yoke 22 can be tilted toward the turbine side to reduce the nozzle opening. That is, the control of the hydraulic servo drive device 30 when adjusting the nozzle opening can be made the same regardless of whether it is attached to either of the attachment surfaces 130A and 130B. Further, the type of the drive shaft 21 may be one, and the types of parts can be reduced, and management can be performed easily. Even when the drive shaft 21 is inserted from any of the attachment surfaces 130A and 130B, the arrangement position of the bush 120 is symmetrical, so there is no possibility of inconvenience in relation to the bush 120.

The best configuration, method, and the like for carrying out the present invention have been disclosed above, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of quantity and other detailed configurations.
Therefore, the description limited to the shape, quantity and the like disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

  For example, in the above-described embodiment, the slide mechanism 20 for moving the movable ring 15 back and forth is used as the nozzle opening degree adjusting mechanism according to the present invention. In the case of a swing vane type that adjusts the degree, a rotation mechanism that rotates the connection ring may be adopted. Even in such a case, the mounting surface for the driving device that drives the rotation mechanism is the If the structure of Claim 1 is satisfy | filled, it will be included in this invention.

  In the above-described embodiment, the hydraulic servo drive device 30 is employed as the drive device according to the present invention. However, the present invention is not limited to this, and a hydraulic drive device without servo control or presence / absence of servo control is used. Regardless, a pneumatic drive device or the like may be used. In addition to a hydraulic type or a pneumatic type, an electric actuator may be used.

  In the above embodiment, the drive shaft 21 has a length straddling the pair of bushes 120. However, the drive shaft 21 has a structure in which a short drive shaft is used and the yoke 22 is fixed to the end of the drive shaft. May be. In such a case, the bush 20 may be inserted only on the side where the drive shaft is inserted, and the bush on the side where the drive shaft is not inserted may be omitted.

  The variable turbocharger of the present invention can be suitably used for an engine having a complicated arrangement of parts, particularly an engine with an EGR device.

1 is a cross-sectional view of a variable turbocharger 1 according to an embodiment of the present invention. II-II sectional view taken on the line of FIG. III-III sectional view taken on the line of FIG. IV-IV sectional view taken on the line of FIG. The perspective view which shows the connection part of a drive shaft and a hydraulic servo drive device. Sectional drawing which shows a hydraulic servo drive device. Sectional drawing for demonstrating a motion of a hydraulic servo drive device. FIG. 6 is another cross-sectional view for explaining the movement of the hydraulic servo drive device. The schematic diagram which shows the lubrication circuit of an engine. The figure which shows a center housing. The perspective view which shows background art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Variable turbocharger, 6 ... Turbo shaft, 7 ... Center housing, 20 ... Slide mechanism which is nozzle opening adjustment mechanism, 21 ... Drive shaft, 30 ... Hydraulic servo drive device which is drive device, 119 ... Insertion hole , 120 ... bush, 130, 130A, 130B ... mounting surface, F ... assembly dimension, L2 ... length dimension.

Claims (3)

In variable turbocharger,
Having a center housing that supports the turboshaft;
A nozzle opening adjustment mechanism for adjusting the nozzle opening;
A drive device for driving the drive shaft of the nozzle opening adjustment mechanism,
The center housing includes a pair of mounting surfaces provided at opposed positions sandwiching the turbo shaft and to which the driving device is mounted, and insertion holes that pass through these mounting surfaces and through which the driving shaft is inserted,
The variable turbocharger, wherein the drive device is attached to any one of the pair of attachment surfaces. The variable turbocharger according to claim 1, wherein
Bushes through which the drive shaft is inserted are provided on both sides of the insertion hole,
The variable turbocharger is characterized in that the assembling dimensions from the respective mounting surfaces to the outer side end portion of the bush adjacent thereto are the same. In the variable turbocharger according to claim 1 or 2,
The variable turbocharger, wherein the nozzle opening adjustment mechanism is configured by a link mechanism, and the drive device is a hydraulic servo drive device.

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