JP6156995B2 - Exhaust turbocharger - Google Patents

Description

  The present invention relates to an exhaust turbocharger used for an internal combustion engine, and particularly, an exhaust turbocharger used for an internal combustion engine for vehicles (for automobiles).

  In general, an exhaust turbocharger has a bypass passage that allows exhaust gas to escape to the outlet without passing through the turbine chamber. A flow control valve controls the amount of exhaust gas that flows to the turbine chamber and the amount of exhaust gas that escapes to the bypass passage. By adjusting at, the supercharging pressure is adjusted by adjusting the driving torque of the compressor blade (output of the turbine blade).

  And in the supercharging pressure control device, there are many diaphragm systems that use negative pressure or positive pressure of intake air as the drive source of the flow control valve, but this diaphragm system requires a vacuum pump in the case of a negative pressure system, so that much While there is a problem that the structure is complicated, there is a problem that the positive pressure type does not operate unless the supercharging pressure is increased. In this regard, a step motor is also used as a drive source, but there is a problem that the cost is increased because the step motor is expensive. In addition, there remains anxiety about whether high durability can be secured in harsh environments exposed to high temperatures.

  On the other hand, the applicant of the present application proposed in Patent Document 1 that the actuator of the supercharging pressure control device is a hydraulic type that drives the flow rate control valve with the pressure oil sent from the oil pump. Since this hydraulic actuator can reliably drive the flow control valve and uses pressure oil, which is an essential element for the internal combustion engine, it can also reduce costs compared to using a step motor. There are advantages.

Japanese Patent Publication No.59-51650

  Although Patent Document 1 has the above-mentioned advantages, it is necessary to newly provide an oil feed pipe for guiding oil to the hydraulic actuator and an oil drain pipe for discharging oil from the hydraulic actuator, so that the piping structure is complicated. There is a problem that there is a limit to cost control.

  The present invention has been made in view of such a current situation, and the use of a hydraulic actuator in a supercharging pressure control device aims to simplify the piping structure while following Patent Document 1. To do.

  The exhaust turbocharger of the present invention includes a turbine blade driven by exhaust gas, a compressor blade that pressurizes intake air, a rotary shaft that connects these, and a housing in which the turbine blade, the compressor blade, and the rotary shaft are incorporated. The rotating shaft is lubricated with oil in a lubrication chamber provided in the housing, and the driving torque of the turbine blade is adjusted by a supercharging pressure control device.

  In the basic configuration of the first aspect of the present invention, in the basic configuration, the supercharging pressure control device includes a valve device that controls a flow rate or a direction of exhaust gas toward the turbine blade, and a hydraulic actuator that drives the valve device; The hydraulic actuator has a structure in which hydraulic oil continues to flow into the drain passage, and the oil is lubricated via a boost pressure control device by connecting the drain passage to the lubrication chamber. Led to the room.

  According to a second aspect of the present invention, in the first aspect, the hydraulic actuator includes a spool valve whose forward and backward movement in the axial direction is controlled by an electromagnetic solenoid, and the spool valve is disposed in parallel with the rotary shaft, The electromagnetic solenoid is disposed on the opposite side of the turbine blade with the spool valve interposed therebetween.

  According to a third aspect of the present invention, in the first or second aspect, when the engine temperature is higher than a preset reference temperature, the oil of the hydraulic actuator flows down from the drain passage as the engine is stopped, and the engine temperature is reduced. When the temperature is equal to or lower than the reference temperature, the oil is controlled to be held inside the hydraulic actuator as the engine is stopped.

  According to the present invention, since the oil for the supercharging pressure control device is used for lubrication of the rotating shaft, the piping for the hydraulic actuator and the piping for lubricating the rotating shaft can be integrated. That is, the supercharging pressure can be controlled and the rotating shaft can be lubricated by a single system of oil supply pipe and oil discharge pipe. For this reason, although it is an internal combustion engine provided with the exhaust turbo supercharger which can perform control of supercharging pressure and lubrication of a rotating shaft reliably, piping structure can be simplified and cost can be suppressed.

  The housing of the exhaust turbocharger has a complicated internal structure. For this reason, a turbine housing that covers the turbine blades, a compressor housing that covers the compressor blades, and a center housing disposed between the turbine housing and the compressor housing, However, in this case, the lubrication chamber for lubricating the rotating shaft is provided in the center housing, while in claim 2, the hydraulic actuator is provided in the center housing. For example, the drain passage provided in the casing of the hydraulic actuator can be directly communicated with the oil supply hole provided in the center housing, and therefore, further simplification and compactness of the structure can be achieved.

  According to the second aspect of the present invention, since the actuator is disposed on the side far from the turbine housing, the actuator hardly receives the radiant heat of the turbine housing. Therefore, thermal damage can be prevented and the durability of the actuator can be improved.

  Now, since oil circulates through each part of the engine, the temperature of the oil also increases in proportion to the temperature of the engine. Since the turbine chamber of the exhaust turbocharger is exposed to the exhaust gas, heat is also transmitted to the lubrication chamber and the hydraulic actuator, and the temperature of these also increases in proportion to the temperature of the engine.

  The lubrication chamber of the exhaust turbocharger is usually designed so that the oil will fall off when the engine stops, but the oil remains in the hydraulic actuator when it is hot. If so, the oil accumulated inside the hydraulic actuator receives heat from the components of the hydraulic actuator and deteriorates, which may adversely affect the lubrication of the entire engine.

  In this regard, when the structure of claim 3 is adopted, if the engine temperature is high enough to cause the deterioration of the oil, the oil of the hydraulic actuator is dropped by the stop of the engine, thereby preventing the deterioration of the oil due to the stop of the engine. be able to. Therefore, it is particularly useful in the case of an internal combustion engine that stops operation when idling. If there is no risk of oil deterioration even when the engine is stopped, the oil remains accumulated in the hydraulic actuator, so the valve device can be driven quickly at the next start-up and has excellent responsiveness. ing.

(A) is the front view of the whole exhaust gas turbocharger which concerns on embodiment, (B) is a partially broken partial front view, (C) is a front view which shows a link mechanism. It is a typical front sectional view of an important part.

(1). Basic Configuration of Structure Next, an embodiment of the present invention will be described with reference to the drawings. As schematically shown in FIG. 1, the exhaust turbocharger includes a turbine blade 1 and a compressor blade 2 arranged concentrically. The turbine blade 1 is disposed in the turbine chamber 2, and the compressor blade 2 is disposed in the compressor chamber 4. The turbine chamber 3 and the compressor chamber 4 are scroll chambers whose sectional areas gradually change. The turbine blade 1 and the compressor blade 2 are connected by a rotating shaft 5.

  The exhaust turbocharger includes a center housing 6, a turbine housing 7 that is overlapped and fixed on one side thereof, and a compressor housing 8 that is overlapped and fixed on the other side of the center housing 6. The turbine chamber 3 is formed on the mating surface of the turbine housing 7, and the compressor chamber 4 is formed on the mating surface of the center housing 6 and the compressor housing 8.

  Needless to say, the turbine housing 6 is inserted in the exhaust system. For example, the exhaust gas inlet 9 is connected to the upstream part of the exhaust system as much as possible (upstream side of the catalytic converter) like a collecting pipe of the exhaust manifold.

  The turbine housing 7 is provided with an exhaust gas inlet 9 through which exhaust gas flows into the turbine chamber 2 and an exhaust gas outlet 10 through which exhaust gas that has passed through the turbine chamber 2 is discharged. In the present embodiment, the exhaust gas inlet 9 faces upward in the direction orthogonal to the rotation axis of the turbine blade 1, and the exhaust gas outlet 10 faces in the axial direction (horizontal direction) of the turbine blade 1.

  The exhaust gas inlet 9 and the exhaust gas outlet 10 are connected by a bypass passage 11 so that the exhaust gas can escape without passing through the turbine chamber 2, and a supercharging pressure control device is configured at the exhaust gas inlet 9. As an example of the valve device, the flow control valve 12 that adjusts the flow rate of the exhaust gas that passes through the exhaust gas inlet 9 is arranged so as to rotate about the axis of the central shaft 13 in plan view.

  The flow control valve 12 has a horizontal shape (front and rear) at a portion of the inner surface of the exhaust gas inlet 9 that is close to the bypass passage 11 and close to the front edge of the bypass passage 11 in the exhaust gas flow direction. (Longitudinal) center shaft 13, and by rotating the flow rate control valve 12 by rotating the center shaft 13 with a hydraulic actuator 14, the exhaust gas inlet 9 is fully opened and the bypass passage 11 is fully closed. From this state, the exhaust gas inlet 9 can be fully closed and the bypass passage 11 can be opened in a stepless manner (a two-step adjustment method of full opening and full closing can also be adopted). In the present embodiment, the flow control valve 12 and the hydraulic actuator 14 constitute a supercharging pressure control device.

  The flow control valve 12 has a quadrangular shape. Therefore, the area in which the flow control valve 12 moves in the exhaust gas inlet 9 is also square. The flow control valve 12 may be disposed in the bypass passage 11. Alternatively, a valve chamber communicating with the exhaust gas inlet 9 and the bypass passage 11 may be provided, and a flow rate control valve may be provided in the valve chamber.

  The compressor housing 8 is provided with a cylindrical intake inlet 15 through which intake air (fresh air) flows, and a cylindrical intake outlet 16 through which pressurized intake air is discharged. The intake inlet 15 faces in the direction (horizontal direction) of the rotation axis of the compressor blade 2, and the intake outlet 17 faces downward (tangential direction) perpendicular to the rotation axis of the compressor blade 2. The posture of the compressor housing 8 (posture viewed from the axial direction) can be arbitrarily set.

  As shown in FIG. 2, the center housing 5 is provided with a lubrication chamber 18 in which a part of the rotary shaft 5 is immersed, and the floating metal 19 in which a part of the rotary shaft 5 is fitted in the lubrication chamber 18 is made non-rotatable. Has been placed. Oil layers (gap) are formed between the lubrication chamber 18 and the floating metal 19 and between the floating metal 19 and the rotating shaft 5. Accordingly, the rotary shaft 5 is held via oil in the floating metal 19 that floats in the lubrication chamber 18, and is rotatably held with the shaft center moving freely.

  Flange 5a, 5b provided in the rotating shaft 5 is arranged on both sides of the lubrication chamber 18, and oil is provided between the flanges 5a, 5b and the floating metal 19 in the cavity of the center housing 6 (not shown). Flow into. The flange 5b on the compressor blade 2 side is manufactured from a member different from the rotating shaft 5. In the center housing 6, an inlet hole 20 through which oil flows is opened in a front portion of the lubrication chamber 18 (portion located on the front side in FIG. 1), and the oil flowing down from the inlet hole 20 to the center housing 6 is Then, the oil returns to the oil pan 24 through the return pipe 23 from the cavity of the center housing 6. In FIG. 2, the entrance hole 20 is opened upward for convenience, but actually, it is opened toward the front as shown in FIG.

(2). Hydraulic Actuator The hydraulic actuator 14 includes a casing 26 fixed to the front surface of the center housing 5 via a bracket 25, a drive rod 27 mounted horizontally on the casing 26, and an axial direction. A spool valve 28 that can move forward and backward is provided, and the spool valve 28 moves forward and backward by electromagnetic solenoid 29 on both sides of the neutral position. The drive rod 27 and the spool valve 28 are arranged in parallel with the rotation shaft 5, the spool valve 28 is arranged in front of the rotation shaft 5, and the drive rod 27 is arranged on the spool valve 28. Yes. The spool valve 28 is disposed at a position slightly higher than the rotating shaft 5.

  The drive rod 27 includes a piston 31 housed in a cylinder chamber 30 of the casing 26, and one end of the piston 31 and one end of the cylinder chamber 30 are connected by a spring 32. The spring 32 is both compressed and stretched around the free length. When the piston 31 is in a neutral position located in the middle portion of the cylinder chamber 30, the spring 32 has a free length. ing. Accordingly, the piston 31 is biased to the neutral position by the spring 32. Further, the drive rod 27 is provided with a front stopper 33 and a rear stopper portion 34 on both sides of the piston 31, and the stroke S of the drive rod 27 is regulated when these stoppers 33, 34 hit the end surface of the cylinder chamber 30. ing.

  One end of the drive rod 27 protrudes to the outside of the casing 26, and one end of the first link 35a is fixed to the central shaft 13 of the flow control valve 12. The first link 35a is connected to the second link 35b and the third link 35c. Are connected to the drive rod 27 via The third link 35c is connected to the bracket 25 so as to rotate about one end 35c 'thereof, and the tip of the drive rod 27 is connected to the intermediate portion of the third link 35c by a pin. The other end of 35c and the other end of the 1st link 35a are connected by the 2nd link 35b so that relative rotation is possible.

  When the piston 31 (drive rod 27) is in the neutral position, the flow control valve 12 is half open, and when the piston 31 (drive rod 27) moves forward from the neutral position, the first link 35a rotates counterclockwise in the figure. By moving, the flow control valve 12 rotates in a direction to close the exhaust gas inlet 9. On the contrary, when the piston 31 (drive rod 27) retreats from the neutral position, the first link 35a rotates clockwise in the figure, and the flow control valve 12 rotates in a direction to open the exhaust gas inlet 9.

  In the embodiment, the half-open state of the flow control valve 12 is set as the origin (neutral position), but the fully closed state or the fully open state of the exhaust gas inlet 9 can be set as the origin. Further, the relationship between the stroke S of the piston 31 (drive rod 27) and the rotation stroke of the flow control valve 12 can be arbitrarily adjusted by changing the connection position of the drive rod 27 with respect to the third link 35c, for example. In order to allow the rotation of the third link 35c, the pin hole for connecting the drive rod 27 is a long hole.

  The hydraulic actuator 14 includes a guide cylinder 37 into which a spool valve 28 is slidably inserted. The guide cylinder 37 is fitted into the casing 26 from the side opposite to the turbine blade 1. The guide cylinder 37 is provided with a solenoid chamber 38 exposed to the outside of the casing 26 on the side opposite to the turbine blade 1. An electromagnetic solenoid 29 is disposed inside the solenoid chamber 38, and the spool valve 28 is disposed inside the electromagnetic solenoid 29. The plunger (movable iron core) 40 provided in the is disposed. By controlling energization to the electromagnetic solenoid 29, the spool valve 28 can be changed to the neutral position, the forward position, and the backward position.

  The spool valve 28 is formed with a center notch 41, a front notch 42 positioned on the front end side sandwiching the center notch 41, and a rear notch 43 positioned on the electromagnetic solenoid side sandwiching the center notch 41. The guide cylinder 37 and the casing 26 are provided with an oil feed port 44, a front drain passage 45 located on the tip side with the oil feed port 44 in between, and a rear drain located on the electromagnetic solenoid side with the oil feed port 44 in between. A passage 46 is opened.

  The front drain passage 45 and the rear drain passage 46 are connected to the inlet hole 20 of the lubrication chamber 18 through the discharge passage 47. An oil supply pipe 49 connected to the discharge passage of the oil pump 48 is connected to the oil supply port 44. The discharge passage 47 may be formed of a pipe or a tube, but the structure is simplified if it is formed integrally with the center housing 5.

  The guide cylinder 37 and the casing 26 have a front passage 50 communicating with the front portion of the cylinder chamber 30 on the upper side of the oil feed port 44 and drain passages 45 and 46 with the spool valve 28 interposed therebetween, and a cylinder chamber. A rear passage 51 communicating with the rear portion of the 30 is opened.

  In FIG. 2, the oil feed port 44 and the drain passages 45 and 46 are arranged side by side for convenience, but in actuality, as shown in FIG. 6 is open to communicate with the inlet hole 20 of the center housing 6. In this case, two inlet holes 20 may be provided corresponding to the two drain passages 45, 46, or the two drain passages 45, 46 are combined into one and communicated with one inlet hole 20. Also good.

(3) Summary In the above configuration, in the state of FIG. 2, the spool valve 28 is in a neutral position by a spring (not shown), and in this state, the pressure oil stops at the center notch 41, It does not flow into the passages 50 and 51. Accordingly, the drive rod 27 is held in the neutral position by the spring 32, and based on this, the flow control valve 12 is in a posture in which the exhaust gas inlet 9 and the bypass passage 11 are half-opened.

  In this neutral state, the center cutout 41, the front cutout 42, and the rear cutout 43 communicate with each other with a slight cross-sectional area, so that oil is discharged through the front cutout 42 and the rear cutout 43. The oil flows into the passage 47, flows into the lubrication chamber 18 from here, lubricates the rotary shaft 5, and then returns to the oil pan 24 through the return line 23. That is, the oil is always supplied in an amount larger than the amount necessary to drive the drive rod 27, and the overflowed oil always flows into the lubrication chamber 18. Therefore, the rotation shaft 5 is lubricated without any trouble.

  When the spool valve 28 is retracted in the direction of the black arrow from the state of FIG. 2, the pressure oil flows from the oil feed port 44 through the center notch 41 to the rear passage 51 and flows into the rear portion of the cylinder chamber 30. When the front passage 50, the front notch 42, and the front drain passage 45 communicate with each other, the oil accumulated in the front portion of the cylinder chamber 30 escapes to the lubrication chamber 18. As a result, the flow control valve 12 rotates from the half-open state in a direction in which the exhaust gas inlet 9 is opened and the bypass passage 11 is closed.

  When the spool valve 28 moves backward and returns to the neutral position, the oil cannot escape from either the front or rear of the cylinder chamber 30, so that the piston 31 (drive rod 27) is held so as not to move back and forth, and the flow control valve 12. The posture is also maintained. The time for which the flow control valve 12 rotates in the direction to open the exhaust gas inlet 9 is proportional to the retracting time of the spool valve 28. When the spool valve 28 remains in the retracted state for a predetermined time or more, the flow control valve 12 is exhausted. The gas inlet 9 is fully opened and the bypass passage 11 is fully closed, and the state is stabilized in that state.

  When the spool valve 28 advances in the direction of the white arrow from the state of FIG. 2, the pressure oil flows from the oil feed port 44 via the center notch 41 to the front passage 50 and flows into the front portion of the cylinder chamber 30. The rear passage 51, the rear cutout 43 and the rear drain passage 46 communicate with each other, so that the oil accumulated in the rear portion of the cylinder chamber 30 escapes to the lubrication chamber 18. As a result, the flow control valve 12 rotates from the half-open state in a direction in which the exhaust gas inlet 9 is closed and the bypass passage 11 is opened.

  The opening time of the flow control valve 12 is proportional to the advance time of the spool valve 28. Therefore, when the spool valve 28 continues to advance for a predetermined time or longer, the flow control valve 12 shifts to a state where the exhaust gas inlet 9 is fully closed and the bypass passage 11 is fully opened. When the spool valve 28 slightly advances and returns to the neutral position, the flow control valve 12 stops in the rotated posture.

  In this way, by controlling the forward and backward movement of the spool valve 28 and the return to the neutral position, the opening degree of the flow control valve 12 can be arbitrarily adjusted, and the supercharging pressure can be adjusted steplessly. .

  When the engine is at a high temperature exceeding the reference temperature, when the engine stops due to idling stop or the like, the spool valve 28 is fully advanced, so that oil is drawn from the inside of the casing 26 and the guide cylinder 37 and directed toward the oil pan. Is set to return. Thereby, it is possible to prevent the oil from staying in the high-temperature casing 26 and the guide cylinder 37 and deteriorating (when the oil pump 48 is stopped, the oil feed pipe 49 functions as a drain pipe, so that the oil in the casing 26 is fed into the oil feed pipe 49. Also falls off.)

  Although it is possible to directly detect the temperature of the cylinder block or the cylinder head as the engine temperature detecting means, the temperature of the cooling water is proportional to the engine temperature. Therefore, in this embodiment, the water temperature sensor is used as the engine temperature sensor. Has been replaced. Therefore, in the present embodiment, a water temperature sensor, a sensor for detecting engine stoppage, and a control device for controlling the electromagnetic solenoid 29 based on signals from these sensors are provided.

  Since a water temperature sensor is provided in a normal internal combustion engine, it is not necessary to install a new one. In addition, since the engine stoppage is detected from the movement of the key, there is no need to newly install a sensor. The control device may be incorporated in an ECU (Engine Control Unit), and therefore, it is not necessary to newly install a control device, and only a necessary control map may be incorporated.

  The hydraulic actuator 14 of the above embodiment employs a three-port, three-cut-out, two-passage system, but the present invention can also employ a one-passage system, in which case two-port, two-cutting system is used. The missing type is sufficient.

  The amount of oil that overflows may be increased by providing a communication hole in the piston 31 of the above embodiment and communicating the front side cylinder chamber and the rear side cylinder chamber.

  The communication hole is provided with a pressure valve that opens when the hydraulic pressure in the cylinder chamber 30 exceeds a predetermined level after the stopper 33 or 34 hits the end surface of the cylinder chamber 30, thereby ensuring the response speed of the drive rod 27. It is possible to secure the amount of overflow oil.

  The drive device for the oil control means such as a spool valve is not limited to an electromagnetic solenoid, and an electric motor or the like can be used. Further, the oil control means is not limited to the spool valve type, and a rotary type or a needle type can also be used. As a means for controlling the output of the turbine blade, instead of (or in addition to) adjusting the amount of exhaust gas flowing into the turbine chamber, it is also possible to adjust the direction of the exhaust gas toward the turbine blade. It is.

  The present invention can actually be embodied in an exhaust turbocharger of an internal combustion engine. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Turbine blade 2 Compressor blade 3 Turbine chamber 4 Compressor chamber 5 Rotating shaft 6 Center housing 7 Turbine housing 8 Compressor housing 11 Bypass passage 12 Flow control valve as an example of valve device constituting supercharging pressure control device 13 Central shaft 14 Excess Hydraulic actuator constituting pressure supply control device 18 Lubrication chamber 20 Inlet hole 24 Oil pan 26 Casing 27 Drive rod 28 Spool valve 29 Electromagnetic solenoid 32 Neutral position return spring 35a to 35c Link 41, 42, 43 Notch 44 Oil feed Port 45, 46 Drain passage 47 Discharge passage 48 Oil pump 49 Oil supply pipe 50, 51 passage

Claims (3)

A turbine blade driven by exhaust gas, a compressor blade that pressurizes intake air, a rotating shaft that connects these, and a housing that includes the turbine blade, the compressor blade, and the rotating shaft. It is lubricated with oil in a lubrication chamber provided in the housing, and the output of the turbine blade is adjusted by a supercharging pressure control device,
The supercharging pressure control device includes a valve device that controls the flow rate or direction of exhaust gas toward the turbine blades, and a hydraulic actuator that drives the valve device. The structure continues to flow in the passage, and by connecting the drain passage to the lubrication chamber, oil is guided to the lubrication chamber via a boost pressure control device,
Exhaust turbocharger. The hydraulic actuator includes a spool valve whose axial movement is controlled by an electromagnetic solenoid. The spool valve is arranged in parallel with the rotary shaft, and the electromagnetic solenoid sandwiches the spool valve and the turbine blades. Arranged on the opposite side,
The exhaust turbocharger according to claim 1. When the engine temperature is higher than the preset reference temperature, the oil of the hydraulic actuator flows down from the drain passage when the engine is stopped, and when the engine temperature is lower than the reference temperature, the engine is stopped. Controlled to hold oil inside the hydraulic actuator,
The exhaust gas turbocharger according to claim 1 or 2.

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