JP2015031160A - Exhaust turbosupercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust turbosupercharger for enabling finely supercharging operation depending on the operating condition of an engine.SOLUTION: The exhaust turbosupercharger includes an exhaust inlet 4, an exhaust turbosupercharger, an exhaust outlet 5, and a bypass passage 8. A valve chest 11 is formed between the exhaust inlet 4 and the bypass passage 8, and a waste gate valve part 12a is arranged which can enter into both the exhaust inlet 4 and the valve chest 11. In the waste gate valve part 12a, a flow rate control valve 12b is integrally provided which can project into the exhaust inlet 4. The waste gate valve part 12a enters into the valve chest 11 in the state that the exhaust inlet 4 is fully opened, and then the flow rate control valve 12b projects into the exhaust inlet 4 to increase the flow rate of exhaust gas. The leakage of the exhaust gas to the bypass passage 8 and a change of the flow rate to adjust the output of an exhaust turbine 2 can be actualized by one actuator 15.

Description

  The present invention relates to an exhaust turbocharger used in an internal combustion engine for a vehicle or the like.

  The exhaust turbocharger is provided with a bypass passage that leads exhaust gas to the exhaust outlet without passing through the turbine chamber to prevent supercharging. The exhaust gas bypass amount is adjusted by a wastegate valve. Has been.

  In this regard, even if a wastegate valve is provided, the turbine outlet pressure is excessively increased at a high engine speed if the scroll area is reduced in order to improve the turbine characteristics at a low engine speed. A technique is disclosed in which a movable cover that rotates in the radial direction is provided at the start end of the chamber, and an appropriate supercharging output is obtained in accordance with the rotational speed by adjusting the cross-sectional area of the exhaust gas flow path.

JP-A-58-10117

  Patent Document 1 is the same as adjusting the flow rate of exhaust gas flowing into the turbine chamber (or adjusting the capacity), and the engine speed and load while driving the exhaust turbocharger. It can be said that it is reasonable to adjust the supercharging output by changing the flow rate of the exhaust gas according to the above.

  In Patent Document 1, the wastegate valve is abolished and replaced with adjustment of the flow path cross-sectional area, and the exhaust turbocharger is always driven. Exhaust gas purification catalyst that the exhaust resistance increases by driving the turbocharger and the fuel consumption deteriorates, and that the exhaust gas flows into the turbine chamber even when the engine is started, and the temperature drop of the exhaust gas is promoted. There is a concern that the activity of the exhaust gas is delayed and the exhaust gas purification becomes insufficient.

  That is, it can be said that appropriate adjustment is difficult only by adjusting the cross-sectional area of the flow path. Regarding this point, it can be said that a waste gate valve may be provided in addition to the movable lid of Patent Document 1. However, if the waste gate valve and the movable lid are driven by separate actuators, the structure becomes complicated and the cost increases accordingly. Will be up.

  The present invention has been made in view of such a current situation, and is intended to realize fine adjustment and control of an exhaust turbocharger with a simple structure.

  In the exhaust turbocharger of the present invention, an exhaust inlet communicates with an upstream side of a turbine chamber in which an exhaust turbine is disposed, and an exhaust outlet communicates with a downstream side. In the first aspect of the invention, a wastegate valve that adjusts the amount of exhaust gas flowing from the exhaust introduction port to the bypass passage, and the exhaust gas in a state in which the bypass passage is fully closed. A flow rate adjusting valve that adjusts the flow rate of the exhaust gas by changing the flow passage area of the inlet is provided so as to be driven by a single actuator.

  According to a second aspect of the present invention, in the first aspect, the waste gate valve and the flow rate adjusting valve are integrated as a valve plate that rotates together around a rotation axis perpendicular to the flow direction of the exhaust gas. The pivot axis is located between one end and the other end of the valve plate and at the edge of the exhaust inlet, so that the upstream side of the pivot axis is the wastegate valve section. The downstream side of the rotation axis is the flow rate adjusting valve part.

  Further, when the valve plate is rotated in one direction on the basis of the posture in which the valve plate is substantially parallel to the flow direction of the exhaust gas and the bypass passage is fully closed, the waste gate valve becomes the exhaust inlet. The flow rate adjusting valve protrudes into the exhaust inlet while being separated from the exhaust inlet, thereby increasing the flow rate of the exhaust gas. When the valve plate is rotated in the other direction, the flow rate adjusting valve is retracted from the exhaust inlet. Thus, the amount of the exhaust gas flowing into the bypass passage through the waste gate valve portion is adjusted.

  According to a third aspect of the present invention, in the second aspect of the present invention, in the flow rate adjusting valve in the valve plate, the rotation is performed so as to enter the inside of the exhaust introduction port at the edge on the opposite side of the wastegate valve across the rotation axis. In this state, an arc-shaped seal rib is provided to prevent exhaust gas from flowing into the bypass passage.

  In the present invention, exhaust gas can be leaked into the bypass passage when supercharging is not required, so that the flow resistance of the exhaust gas can be suppressed as much as possible to contribute to improvement of fuel consumption, and the exhaust gas can be cooled as much as possible during warm-up operation. It can lead to the catalyst for purification without causing it to contribute to the early activation of the catalyst.

  Since the cross-sectional area of the flow path to the turbine chamber can be adjusted by the flow rate adjustment valve, the turbine output can be adjusted according to the engine speed, load, etc. Although the machine can be finely adjusted and controlled, since the wastegate valve and the flow rate adjusting valve are operated by one actuator, it is possible to suppress the increase in cost and to prevent the increase in space and the increase in weight.

  According to the second aspect of the present invention, the waste gate valve and the flow rate adjusting valve are integrated as a valve plate, so that the structure is further simplified and the cost can be reduced. Further, when the configuration of claim 3 is adopted, there is an advantage that the exhaust gas heading toward the turbine chamber can be prevented from leaking into the bypass passage with a simple structure.

It is sectional drawing of 1st Embodiment, (A) is AA sectional view (plane sectional drawing) of (B), (B) is exhausted by BB sectional drawing (side sectional drawing) of (A). It is a figure of the state which has fully closed the inlet. FIG. 2A is a sectional view taken along the line IIA-IIA of FIG. 1B, and FIG. 2B is a diagram of a reference state (neutral state) in which the bypass passage is fully closed and the flow rate adjustment valve is also retracted. It is a figure of the throttling state where the bypass passage was fully closed and the flow rate adjustment valve protruded. (A) is a typical perspective view of 2nd Embodiment, (B) is a principal part plane sectional view of 3rd Embodiment.

(1) Structure of First Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. First, the structure of the first embodiment shown in FIGS. The present embodiment is applied to an exhaust turbocharger mounted on an internal combustion engine for a vehicle, and has a housing 1 and an exhaust turbine 2 incorporated in the housing 1 as main elements, as in the prior art. The housing 1 has a turbine chamber (vortex chamber) 3 in which an exhaust turbine 2 is accommodated, an exhaust introduction port 4 continuous to the start end of the turbine chamber 3, and an exhaust outlet 5 continuous to the end of the turbine chamber 3. Yes.

  The exhaust introduction port 4 extends in the direction of one tangent on the outer periphery of the turbine chamber 3, and the start end of the exhaust introduction port 4 is connected to an exhaust upstream pipe 6 such as an exhaust manifold by a flange joint or the like. The exhaust outlet 5 extends in the direction of the rotational axis of the turbine chamber 3, so that the exhaust gas flows into the turbine chamber 3 from the circumferential direction and is discharged in the axial direction. An exhaust passage such as an exhaust pipe or a catalyst case is connected to the exhaust outlet 5 by a flange joint or the like.

  The exhaust turbine 2 has a large number of blades, a rotating shaft 7 is fixed to the shaft center, and a compressor blade (not shown) is fixed to the rotating shaft. Although the housing 1 is composed of a plurality of members, it is shown in a single structure for convenience in this figure.

  The exhaust inlet 4 and the exhaust outlet 5 communicate with each other through a curved bypass passage 8. In this case, as shown in FIG. 1B, the turbine chamber 3 is located in the direction perpendicular to the rotational axis 9 of the exhaust turbine 2 and the axis 10 of the exhaust inlet 4 in the inner peripheral portion of the exhaust inlet 4. A valve chamber 11 communicating with the exhaust introduction port 4 is formed on the opposite side of the valve chamber 11, and a bypass passage 8 is opened in a portion of the valve chamber 11 far from the exhaust introduction port 4. Therefore, the exhaust gas flows into the bypass passage 8 via the valve chamber 11.

  A rotating valve plate 12 is arranged in a space formed by the valve chamber 11 and the exhaust inlet 4. The valve plate 12 is a band plate-like single structure, and is arranged so as to rotate around the axis of the drive shaft 13 parallel to the rotation axis 9 of the exhaust turbine 2. In this case, the drive shaft 13 is provided in a portion of the valve plate 12 that is closer to the downstream side as viewed from the flow direction of the exhaust gas, so that a portion of the valve plate 12 upstream of the drive shaft 13 is waisted. A portion of the valve plate 12 on the downstream side of the drive shaft 13 is formed with the flow rate adjusting valve portion 13b.

  The start end portion of the exhaust introduction port 4 and the start end portion of the turbine chamber 3 are circular in cross section, but the space constituted by the area where the valve plate 12 rotates in the exhaust introduction port 4 and the valve chamber 11 is In order to allow the valve plate 12 to rotate, the valve plate 12 has a square cross section. Therefore, the upper and lower inner surfaces of the exhaust introduction port 4 and the upper and lower inner surfaces of the valve chamber 11 are continuous on the same plane.

  The upstream portion of the inner peripheral surface of the valve chamber 11 is a front curved portion 11a that allows the tip edge of the wastegate valve portion 12a in the valve plate 12 to rotate in the vicinity, A downstream portion of the inner peripheral surface of the valve chamber 11 is a rear curved portion 11a that allows the tip edge of the flow rate adjusting valve portion 12b in the valve plate 12 to rotate in proximity. In addition, the leading edge of the flow rate adjusting valve portion 12 b in the valve plate 12 is integrally provided with a seal rib 14 extending toward the bypass passage 8 when viewed from the axial direction of the drive shaft 13. The seal rib 14 is curved in an arc shape and is close to the rear curved portion 11 a of the housing 1.

  The drive shaft 13 is driven by an actuator 15. The actuator 15 is preferably one that can arbitrarily control the rotation amount of a step motor or the like. In addition to or in addition to providing the seal rib 14 on the flow rate adjusting valve portion 12b in the valve plate 12, as shown by a one-dot chain line in FIG. It is also possible to provide a wall plate 16 that extends toward the pivot axis.

(2). Description of Movement FIG. 1B shows a state in which the exhaust inlet 4 is fully closed by the valve plate 12, and in this state, the exhaust gas does not flow into the turbine chamber 3, but the entire amount is in the valve plate. 12 to the bypass passage 8. Therefore, when it is not necessary to drive the exhaust turbocharger, for example, during warm-up operation, this mode can contribute to stable rotation and early activation of the catalyst. Further, exhaust resistance can be suppressed by using this mode even in a low rotation / low load region.

  Although not shown in the figure, the opening degree of the exhaust inlet 4 can be arbitrarily set. Therefore, by adjusting the amount of exhaust gas flowing into the turbine chamber 3 and the amount of escape to the bypass passage 8 according to the engine speed and load, it is possible to adjust to an appropriate supercharging pressure.

  FIG. 2B shows a reference state (neutral state) in which the bypass passage 8 is fully closed and the exhaust inlet 4 is fully open. In this state, the entire amount of exhaust gas flows into the turbine chamber 3, but since the cross-sectional area of the exhaust inlet 4 is maximum, the flow rate of the exhaust gas is the lowest reference speed. For example, when a moderate supercharging pressure is sufficient as in the case of medium rotation and medium load, an appropriate supercharging effect can be obtained by using this mode.

  FIG. 3 shows a state where the bypass passage 8 is fully closed and the exhaust inlet 4 is narrowed. In this state, the exhaust gas flows into the turbine chamber 3, and the flow rate of the exhaust gas is increased by the narrowing of the cross-sectional area of the flow path at the end portion of the exhaust inlet 4. The dynamic pressure acting on the exhaust gas increases, and the output of the exhaust turbine 2 also increases. Accordingly, the supercharging pressure is higher than that in the reference state.

  When a large amount of fuel is required for the engine, such as in a medium speed / high load state such as running on a slope, high torque can be obtained by using this mode. Needless to say, the throttle amount of the exhaust inlet 4 can be arbitrarily set by adjusting the opening of the valve plate 11.

  In this state, since the seal rib 14 is provided on the flow rate adjustment valve 12b in the valve plate 12, the exhaust gas does not flow into the bypass passage 8 even if the flow rate adjustment valve 12b protrudes into the exhaust introduction port 4. In this case, the backflow of the exhaust gas can be dealt with by providing the wall plate 16 as shown in FIG. 1B. However, the vortex flow is generated only by providing the wall plate 16, and the smooth rotation of the exhaust turbine 2 is impaired. There is a risk of being. On the other hand, when the seal rib 14 is provided, the exhaust gas smoothly flows into the turbine chamber 3 without generating a vortex, so that there is an advantage that smooth rotation of the exhaust turbine 2 can be ensured.

(3). Other Embodiments The first embodiment described above is a case where the waste gate valve portion 12a and the flow rate adjustment valve 12b are integrated, but in the present invention, the waste gate valve portion 12a and the flow rate adjustment valve 12b. It is also possible to have different structures. An example is shown in FIG.

  Of these, in the second embodiment shown in FIG. 4 (A), first, the drive shaft 13a of the waste gate valve portion 12a is formed into a hollow structure, and the drive shaft 13b of the flow rate adjusting valve 12b is inserted into the drive shaft 13a. The part 12a and the flow rate adjusting valve 12b can be independently rotated around a concentric axis. The drive shaft 13a of the waste gate valve portion 12a is notched between one end and the other end, and the flow rate adjusting valve 12b is fixed to the drive shaft 13b at the notch.

  The wastegate valve portion 12 a hits the stepped portion 17 of the housing 1 with the exhaust introduction port 4 fully opened so as not to enter the valve chamber 11. On the other hand, the flow rate adjusting valve 12b is urged to a closed posture that does not protrude from the exhaust inlet 4 by a spring (not shown).

  The drive shafts 13a and 13b are provided with crank-like pushing portions 13a 'and 13b' exposed to the outside of the housing 1, and are driven by the actuator 15 on the pushing portions 13a 'and 13b'. The operation ring 18 is fitted.

  The operation ring 18 has first and second holes 19 and 20 into which the pushing portions 13a 'and 13b' are fitted, but a second hole 20 into which the pushing portion 13b 'of the flow rate adjusting valve 12b is fitted. Is an arc-shaped elongated hole, and the torque of the operation ring 18 does not act on the flow rate adjusting valve 12b when the wastegate valve portion 12a opens and closes the exhaust introduction port 4. That is, the operation ring 18 is used to open and close only the wastegate valve portion 12a.

  The first hole 19 into which the pushing portion 13a 'of the waste gate valve portion 12a is fitted is also an arc-shaped elongated hole. The first hole 19 has a pushing portion 13a' in the waste gate valve portion 12a. Is slidably disposed in the direction of the solid arrow, and the stopper 21 is urged in the direction of the solid arrow by a spring (not shown).

  Accordingly, when the pushing portion 13a ′ is pushed while being supported by the spring, the wastegate valve portion 12a rotates in the direction in which the exhaust introduction port 4 is opened (the direction in which the bypass passage 8 is closed). The wastegate valve portion 12a rotates to a posture in which the exhaust inlet 4 is fully opened. When the operation ring 18 is further rotated in the direction of the solid arrow, the wastegate valve portion 12a stops rotating, and the stopper 21 escapes against the spring while the pushing portion 13b 'of the flow rate adjusting valve 12b is moved. By being pushed by the operation ring 18, the flow rate adjustment valve 12 b protrudes into the exhaust inlet 4.

  Since the flow rate adjusting valve 12b is biased to the closed position by a spring, when the operation ring 18 is rotated in the direction of the dotted arrow, the flow rate adjusting valve 12b is rotated in the closing direction by the spring. Therefore, the flow passage area of the exhaust inlet 4 can be freely adjusted by rotating the operation ring 18.

  In the third embodiment shown in FIG. 4B, a semicircular drive member 22 is arranged in the valve chamber 11, and the drive member 22 individually pushes the wastegate valve portion 12a and the flow rate adjustment valve 12b from the back side. The waste gate valve portion 12a and the flow rate adjustment valve 12b can be individually rotated.

  In this embodiment, the wastegate valve portion 12 a and the flow rate adjustment valve 12 b are biased by a spring in a closed posture (reference posture) extending along the inner peripheral edge of the exhaust inlet 4. Moreover, the rotation fulcrum of the wastegate valve part 12a, the drive member 22, and the flow rate adjustment valve 12b is mutually separated, and the rotation fulcrum of the wastegate valve part 12a is located on both sides of the drive member 22 and the rotation fulcrum. And the rotation fulcrum of the flow rate adjusting valve 12b are located.

  Although not shown in the drawing, a pressure portion corresponding to the drive member 22 is provided on the back surface of the wastegate valve portion 12a, and the flow rate adjustment valve 12b is introduced into the exhaust gas by pressing the flow rate adjustment valve 12b from the back side with the pressure portion. It is also possible to protrude toward the inside of the mouth 4 (in this case, the wastegate valve portion 12a needs to enter the inside of the valve chamber 11 as in the first embodiment).

  The present invention can be embodied in various ways other than the above-described embodiment. For example, the waste gate valve and the flow rate adjustment valve are not limited to a rotary type, and a shutter type or the like can also be employed. As the actuator, various types such as a hydraulic type, an electromagnetic solenoid type, or a type using pneumatic pressure (positive pressure or negative pressure) can be adopted.

  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 Housing 2 Exhaust turbine 3 Turbine chamber 4 Exhaust inlet 5 Exhaust outlet 8 Bypass passage 11 Valve chamber 12 Valve plate 12a Wastegate valve part 12b Flow rate adjustment valve part 13 Drive shaft 14 Seal rib 15 Actuator

Claims (3)

An exhaust inlet communicates with the upstream side of the turbine chamber where the exhaust turbine is disposed, and an exhaust outlet communicates with the downstream side. The exhaust inlet and the exhaust outlet are connected by a bypass passage. And
A wastegate valve that adjusts the amount of exhaust gas flowing from the exhaust inlet to the bypass passage, and a flow rate that adjusts the flow velocity of the exhaust gas by changing the flow passage area of the exhaust inlet with the bypass passage fully closed The control valve is provided to be driven by one actuator;
Exhaust turbocharger. The waste gate valve and the flow rate adjustment valve are integrated as a valve plate that rotates together around a rotation axis perpendicular to the flow direction of the exhaust gas, and the rotation axis is connected to one end of the valve plate and the other. By positioning it between the ends and at the edge of the exhaust introduction port, the upstream side with respect to the rotation axis is formed as a wastegate valve part, and the downstream side with respect to the rotation axis is defined as a flow rate adjustment valve part. And
When the valve plate is rotated in one direction on the basis of a posture in which the valve plate is substantially parallel to the exhaust gas flow direction and the bypass passage is fully closed, the wastegate valve is separated from the exhaust inlet. However, when the flow rate adjustment valve protrudes into the exhaust introduction port, the flow rate of the exhaust gas becomes high, and when the valve plate is rotated in the other direction, the flow rate adjustment valve unit moves backward from the exhaust introduction port and The amount of exhaust gas flowing into the bypass passage by the wastegate valve section entering the exhaust inlet is adjusted,
The exhaust turbocharger according to claim 1. The exhaust gas is moved to the bypass passage side in a state of being rotated so as to enter the inside of the exhaust introduction port at the edge on the opposite side to the wastegate valve across the rotation axis among the flow rate adjusting valves in the valve plate. An arc-shaped seal rib is provided to prevent inflow,
The exhaust turbocharger according to claim 2.

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