JP2010281281A - Supercharger and multistage supercharging device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharger capable of suppressing an increase in the size of an overall supercharging device, and also provide a multistage supercharging device having the supercharger. <P>SOLUTION: This high-pressure supercharger 3 includes a housing 40 in which a high-pressure side compressor chamber 70 for compressing the air sucked therein is formed and a compressor wheel 52 installed in the compressor chamber 70. The high-pressure side compressor chamber 70 includes a suction chamber 71 for supplying the air sucked into the high-pressure supercharger 3 toward the compressor wheel 52 and a diffuser chamber 73 for reducing the flow velocity of the air discharged from the compressor wheel 52. The housing 40 includes a first communication part 41d and a second communication part 42e which communicate with the diffuser chamber 73 separately from the suction chamber 71. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a supercharger including a compressor chamber that compresses air, and a compressor wheel that is accommodated in the compressor chamber, and a multistage supercharger including the same.

  For the purpose of improving the supercharging characteristics, high-pressure and low-pressure compressor wheels are provided in series in the intake passage in the intake passage, and the high-pressure and low-pressure turbine wheels are provided in the exhaust passage in the exhaust passage. What is provided with what is called a multistage supercharging device provided in series with respect to is known. An example of such a multistage supercharging device is that disclosed in Patent Document 1.

With reference to FIG. 7, a multistage supercharger having a conventional structure including that described in Patent Document 1 will be described.
As shown in FIG. 7, in the internal combustion engine 200, air is supplied to a combustion chamber (not shown) provided in the internal combustion engine 200 via an intake manifold 211 provided in the intake passage 210. Then, the air-fuel mixture combusted in the combustion chamber is discharged as exhaust gas to the exhaust passage 230 via the exhaust manifold 212.

  A low-pressure compressor chamber 251 of the low-pressure supercharger 250 is connected to the intake passage 210 through a first connection pipe 240, and the high-pressure supercharger 260 is connected to the intake downstream side of the compressor chamber 251 through a second connection pipe 241. A high-pressure side compressor chamber 261 is connected. A third connection pipe 242 for connecting to the intake manifold 211 is provided on the intake downstream side of the compressor chamber 261. The second connection pipe 241 is provided with a fourth connection pipe 243 that is a bypass pipe that branches from the second connection pipe 241 and bypasses the high-pressure side compressor chamber 261 and connects to the third connection pipe 242. Yes. The fourth connection pipe 243 is provided with a switching valve 270 that switches between a state in which the intake air from the low pressure side compressor chamber 251 is supplied to the high pressure side compressor chamber 261 and a state in which the intake air is supplied to the fourth connection pipe 243. .

JP 2005-98250 A

  By the way, in such a multistage supercharging device, the high-pressure supercharger and the low-pressure supercharger are connected by many connection pipes such as the fourth connection pipe 243 provided with the switching valve 270. The connection structure has become complicated and has led to an increase in size. Further, such a problem is not limited to the multistage supercharging device, and may occur in a supercharging device including a plurality of superchargers.

  This invention is made | formed in view of the said situation, The objective is to provide the supercharger which can suppress the enlargement of the whole supercharging device, and a multistage supercharging device provided with the same.

In the following, means for achieving the above object and its effects are described.
(1) The invention described in claim 1 is a supercharger comprising a housing in which a compressor chamber for compressing air is formed and a compressor wheel provided in the compressor chamber. A suction chamber that supplies inflowing air toward the compressor wheel and a diffuser chamber that decelerates the flow velocity of the air sent from the compressor wheel are provided, and the housing communicates with the diffuser chamber. The gist of the present invention is that a bypass route is formed in which the inflowing air bypasses the compressor wheel and flows into the diffuser chamber, and a switching valve for switching the open / close state is provided in the bypass route.

  According to the present invention, since the bypass is provided in the turbocharger housing, when a plurality of superchargers are connected to each other, the supercharger is separately provided in comparison with the configuration in which the housing and the bypass are provided separately. Connection pipes connecting the machines to each other can be omitted. In addition, since a switching valve is provided in the bypass, an external passage for connecting the switching valve and the bypass can be omitted. As a result, the overall size of the supercharging device can be suppressed.

  (2) The invention according to claim 2 is the supercharger according to claim 1, wherein the housing is provided with a suction side connection portion constituting the suction chamber, and the suction side connection portion is An inner connecting portion that defines a suction chamber and an outer connecting portion that surrounds the inner connecting portion from the rotational radial direction of the compressor wheel are provided, and the bypass route includes an outer surface of the inner connecting portion and an outer connecting portion of the outer connecting portion. The gist is that it is constituted by a space formed between the inner surface and the inner surface.

  (3) The invention according to claim 3 is the supercharger according to claim 2, wherein the suction side connection portion is provided in a mode extending in a rotation axis direction of the compressor wheel, and the bypass is The gist is to be provided in a manner extending in the rotation axis direction.

  According to the present invention, since the suction side connection portion is provided in a mode extending in the rotation axis direction of the compressor wheel and the bypass route is provided in a mode extending in the rotation axis direction, the diffuser is provided from the inlet of the compressor chamber via the bypass route. The flow path to the chamber can be formed without bending. Therefore, an increase in the turbulence of the air flow passing through the detour can be suppressed.

  (4) The invention according to claim 4 is the supercharger according to claim 2 or 3, wherein the bypass is formed in an annular shape surrounding the rotation shaft of the compressor wheel. To do.

  According to the present invention, in a configuration in which a plurality of superchargers are connected in series in the air flow direction, the supercharger on the downstream side in the air flow direction is discharged from the supercharger on the upstream side in the air flow direction. The air flow includes a swirl flow along the inner wall surface of the connecting pipe that connects the upstream turbocharger and the downstream turbocharger. Therefore, by using the configuration of the present invention for the turbocharger downstream in the air flow direction, an air flow including the swirling flow is formed in the detour connected to the connection pipe, and the air flow is detoured. It will be sent to the diffuser chamber along the inner wall surface. Therefore, by forming the detour in an annular shape, an air flow including a swirl flow can be efficiently fed into the diffuser chamber through the detour.

  (5) The invention according to claim 5 is the turbocharger according to any one of claims 1 to 4, wherein the switching valve has a predetermined interval in a rotational circumferential direction of the compressor wheel. The gist is to switch the open / closed state of the detour by rotation of the plurality of valve bodies.

  (6) A sixth aspect of the present invention is the supercharger comprising a plurality of superchargers, wherein the supercharger is one of the plurality of superchargers. The gist is to provide the supercharger according to any one of the above.

  (7) In the invention according to claim 7, the high-pressure supercharger having a small capacity is connected to the low-pressure supercharger having the larger capacity than the high-pressure supercharger, the high-pressure supercharger, and the low-pressure supercharger. In the multistage supercharger comprising a connection passage, the compressor chamber of the high pressure supercharger and the compressor chamber of the low pressure supercharger are connected in series in the air flow direction, and the high pressure supercharger It is provided in the downstream of the same air circulation direction of a low pressure supercharger, and makes it a summary to comprise the supercharger as described in any one of Claims 1-5 as said high pressure supercharger.

  According to the present invention, since the detour is formed in the housing of the high-pressure turbocharger provided on the downstream side in the air flow direction, the air from the detour flows into the diffuser chamber so that the static pressure is reduced from the dynamic pressure. The pressure is converted to pressure. Therefore, the supercharging characteristic of the multistage supercharging device can be improved.

  (8) The invention according to claim 8 is the multistage turbocharger according to claim 7, wherein the switching valve is in a closed state when the low-pressure supercharger is stopped, and the low-pressure supercharger is The gist is that the valve is opened when the machine is in a driving state.

  According to the present invention, when the low pressure supercharger is stopped, the valve is closed so that the air discharged from the low pressure supercharger is sent to the compressor wheel via the suction chamber of the high pressure supercharger. Become. Therefore, the high pressure supercharger can efficiently perform supercharging. In addition, when the low-pressure supercharger is in a driving state, the air discharged from the low-pressure supercharger is sent to the diffuser chamber of the high-pressure supercharger via a bypass, so that the low-pressure supercharger The dynamic pressure of the discharged air is converted to static pressure, and supercharging by the low pressure supercharger can be performed efficiently.

The schematic diagram which shows typically the structure of the multistage supercharging apparatus provided with the supercharger of this invention. Sectional drawing which shows the cross-section of a high voltage | pressure supercharger about the supercharger of the embodiment. About the turbocharger of the embodiment, (a) a sectional view showing a sectional structure along line BB in FIG. 2, (b) a sectional view showing a sectional structure along line CC in FIG. 4 (a). Figure. The top view which shows the planar structure seen from the arrow A direction of FIG. 2 about the supercharger of the same embodiment is shown, (a) The top view which shows the planar structure when the switching valve is in the valve closing state, (b) ) A plan view showing a planar structure when the switching valve is in an open state. Sectional drawing which shows the cross-section of a low voltage | pressure supercharger about the supercharger of the embodiment. The top view which shows the planar structure of the supercharger about other embodiment which actualized the supercharger of this invention. The schematic diagram which shows typically the structure of the conventional multistage supercharging device.

  1 to 5, an embodiment in which a multistage supercharger equipped with a supercharger according to the present invention is embodied as a multistage supercharger mounted on a diesel engine (hereinafter referred to as “engine 1”). A form is demonstrated.

  As shown in FIG. 1, the engine 1 has an intake passage 23 that supplies intake air taken into the engine 1 from the outside to the combustion chamber 11 of the engine 1, and exhausts exhausted from the combustion chamber 11 to the outside. The exhaust passage 33 is connected to each other. A mixture of intake air and fuel injected from the fuel injection valve is supplied to the combustion chamber 11, and the engine 1 obtains a driving force by burning the mixture in the combustion chamber 11. Each of the intake passage 23 and the exhaust passage 33 is provided with a multistage supercharging device 2 that supercharges the intake air in the intake passage 23 by the exhaust gas flowing through the exhaust passage 33.

  The intake passage 23 is provided with an intake manifold 22 that supplies intake air from the intake passage 23 to each cylinder of the engine 1. In the intake passage 23, an air cleaner 24 that captures foreign matters such as dust contained in the outside air in order from the upstream side of the intake air, an intercooler 25 that cools the intake air, and diesel that adjusts the amount of intake air supplied to the combustion chamber 11. A throttle 26 is provided.

The exhaust passage 33 is provided with an exhaust manifold 32 into which exhaust from the combustion chamber 11 flows in order from the exhaust upstream side, and an exhaust purification device 34 for purifying the exhaust.
The multistage supercharger 2 includes a high-pressure supercharger 3 and a low-pressure supercharger 4, an intake-side supercharge passage 90 and an exhaust-side supercharge passage 100 that connect the high-pressure supercharger 3 and the low-pressure supercharger 4 to each other. It is comprised by. The low pressure supercharger 4 is set larger than the high pressure supercharger 3 and has a larger capacity. The high pressure supercharger 3 is connected in series with the low pressure supercharger 4 in the intake air flow direction, and is provided on the intake downstream side of the low pressure supercharger 4.

  The intake side supercharging passage 90 is provided between the air cleaner 24 and the intercooler 25 in the intake passage 23. The exhaust side supercharging passage 100 is provided between the exhaust manifold 32 and the exhaust purification device 34 in the exhaust passage 33.

  A high pressure side turbine chamber 80 and a high pressure side compressor chamber 70 are formed in the housing 40 of the high pressure supercharger 3. The high-pressure side turbine chamber 80 is provided with a turbine wheel 53 that rotates by exhaust. The high-pressure side compressor chamber 70 is provided with a compressor wheel 52 that supercharges intake air. These wheels are connected to each other by a rotor shaft 51.

  In the housing 40A of the low pressure supercharger 4, a low pressure side turbine chamber 80A and a low pressure side compressor chamber 130 are formed. The low-pressure turbine chamber 80A is provided with a turbine wheel 53A that rotates by exhaust. The low pressure side compressor chamber 130 is provided with a compressor wheel 52A for supercharging intake air. These wheels are connected to each other by a rotor shaft 51A.

  The intake side supercharging passage 90 includes an inlet side intake passage 91, an outlet side intake passage 92, a low pressure side intake passage 93, a communication intake passage 94, and a bypass passage 95. The bypass passage 95 is provided with an intake side switching valve 110. Note that the intake side switching valve 110 and the bypass passage 95 in which the intake side switching valve 110 is provided are actually provided in the housing 40 of the high-pressure supercharger 3, but in FIG. Show.

  The inlet side intake passage 91 connects the air cleaner 24 and the low pressure side compressor chamber 130. The outlet side intake passage 92 connects the high pressure side compressor chamber 70 and the intercooler 25. The low-pressure side intake passage 93 and the communication intake passage 94 connect the low-pressure side compressor chamber 130 and the high-pressure side compressor chamber 70. The bypass passage 95 branches from the communication intake passage 94 and is connected to the outlet side intake passage 92. The intake side switching valve 110 supplies the intake air in the communication intake passage 94 to the compressor wheel 52 of the high-pressure side compressor chamber 70 and bypasses the compressor wheel 52 by the bypass passage 95 and supplies it directly to the intercooler 25. And switch.

  The exhaust side supercharging passage 100 includes an inlet side exhaust passage 101, a high pressure side exhaust passage 102, a low pressure side exhaust passage 103, a communication exhaust passage 104, and an outlet side exhaust passage 105. In addition, an exhaust side switching valve 106 is provided in the low pressure side exhaust passage 103.

  One end of the inlet side exhaust passage 101 is connected to the exhaust manifold 32. The high pressure side exhaust passage 102 connects the other end of the inlet side exhaust passage 101 and the high pressure side turbine chamber 80. The low pressure side exhaust passage 103 connects the other end of the inlet side exhaust passage 101 and the low pressure side turbine chamber 80A. The communication exhaust passage 104 connects the high-pressure turbine chamber 80 and the low-pressure turbine chamber 80A. The exhaust side switching valve 106 switches between a state in which the exhaust gas in the inlet side exhaust passage 101 is supplied to the high pressure side turbine chamber 80 and a state in which the exhaust side switching valve 106 is directly supplied to the low pressure side turbine chamber 80A without passing through the turbine chamber 80. Further, the communication exhaust passage 104 is connected to the low pressure side exhaust passage 103 on the exhaust downstream side of the exhaust side switching valve 106 of the low pressure side intake passage 93.

Next, the flow of exhaust and intake air in the exhaust side supercharging passage 100 and the intake side supercharging passage 90 according to the engine load state will be described.
When the engine load is low, the exhaust side switching valve 106 and the intake side switching valve 110 are each maintained in a closed state. As a result, exhaust and intake air flow in the multistage turbocharger 2 as follows.

  That is, the exhaust from the exhaust manifold 32 is supplied to the turbine chamber 80 of the high-pressure supercharger 3 through the inlet side exhaust passage 101 as shown by the solid line arrow in the figure. The exhaust from the turbine chamber 80 is supplied to the turbine chamber 80A of the low-pressure supercharger via the communication exhaust passage 104. The exhaust from the turbine chamber 80A flows out to the exhaust downstream side (that is, the exhaust purification device 34 side) of the multistage supercharger 2.

  On the other hand, the intake air from the air cleaner 24 is supplied to the low-pressure compressor chamber 130 of the low-pressure supercharger 4 via the inlet-side intake passage 91 as indicated by the solid line arrow in the figure. The intake air discharged from the compressor chamber 130 is supplied to the compressor chamber 70 of the high pressure supercharger 3 through the low pressure side intake passage 93 and the communication intake passage 94. The intake air discharged from the compressor chamber 70 is supplied to the intercooler 25 via the outlet side intake passage 92.

  When the engine load is low, the exhaust gas is supplied to the high-pressure supercharger 3 before being supplied to the low-pressure supercharger 4, and the kinetic energy of the exhaust gas is consumed in the high-pressure supercharger 3. The turbine wheel 53A of the machine 4 is almost stopped. On the other hand, the high pressure supercharger 3 is driven by exhaust gas passing through the turbine wheel 53. In particular, since the high pressure supercharger 3 is small in size, the turbine wheel 53 is driven even when the flow rate of the exhaust gas at the time of low load is small. As a result, the compressor wheel 52 connected by the rotor shaft 51 is driven as the turbine wheel 53 is driven, so that supercharging is performed only by the high-pressure supercharger 3.

  When the engine load is a medium load and a high load, the exhaust side switching valve 106 and the intake side switching valve 110 are each maintained in an open state. As a result, exhaust and intake air flow in the multistage turbocharger 2 as follows.

  That is, the exhaust from the exhaust manifold 32 is supplied to the turbine chamber 80A of the low-pressure supercharger 4 through the inlet-side exhaust passage 101 as indicated by the broken line arrow in the figure. The exhaust discharged from the turbine chamber 80A flows out to the exhaust passage 33 on the exhaust downstream side (that is, the exhaust purification device 34 side) of the multistage supercharging device 2.

  On the other hand, the intake air from the air cleaner 24 is supplied to the low-pressure compressor chamber 130 of the low-pressure supercharger 4 through the inlet-side intake passage 91 as indicated by the broken-line arrows in the drawing. The intake air discharged from the compressor chamber 130 is supplied to the outlet side intake passage 92 through the low pressure side intake passage 93 and the bypass passage 95. That is, the intake air discharged from the low pressure side compressor chamber 130 is supplied to the outlet side intake passage 92 without passing through the high pressure side compressor chamber 70. The intake air supplied to the outlet side intake passage 92 is supplied to the intercooler 25.

  When the engine load is a medium load and a high load, exhaust gas is supplied only to the low-pressure supercharger 4, so that the turbine wheel 53 </ b> A of the low-pressure supercharger 4 is driven. Therefore, when the engine load is medium load and high load, supercharging by the low pressure supercharger 4 is performed. As described above, the engine 1 can obtain the supercharging characteristic of the multistage supercharging device 2 according to the engine load state.

  Next, a detailed structure of the high-pressure supercharger 3 will be described with reference to FIGS. 3 and 4, a part of the first compressor housing 41, the compressor wheel 52, and the rotor shaft 51 are omitted. Hereinafter, the direction in which the rotor shaft 51 extends is referred to as “axial direction”, the side in which the high pressure side compressor chamber 70 is formed in the axial direction is referred to as “compressor side”, and the side in which the high pressure side turbine chamber 80 is formed is referred to as “turbine side”. " In addition, a direction perpendicular to the axial direction is defined as a “radial direction”, a direction approaching the rotor shaft 51 is defined as “inside”, and a direction away from the rotor shaft 51 is defined as “outside”.

  As shown in FIG. 2, the housing 40 of the high-pressure supercharger 3 includes a first compressor housing 41 to a third compressor housing 43 that form a high-pressure side compressor chamber 70, and a first turbine housing that forms a high-pressure side turbine chamber 80. 44 and the second turbine housing 45, and a bearing housing 46 that forms a bearing chamber 50. The bearing housing 46 is provided between the first compressor housing 41 to the third compressor housing 43 and the first turbine housing 44 and the second turbine housing 45 in the axial direction.

  The bearing housing 46 is provided with a bearing mechanism 60 that rotatably supports the rotor shaft 51. The bearing mechanism 60 includes a first bearing mechanism 61 provided on the compressor side in the axial direction and a second bearing mechanism 62 provided on the turbine side in the axial direction.

  The first compressor housing 41 is provided with a substantially cylindrical first suction side connection portion 41 a that is connected to the communication intake passage 94. On the turbine side in the axial direction of the first suction side connection portion 41a, a substantially annular first scroll portion 41b extending from the first suction side connection portion 41a to the outside in the radial direction is provided. The first scroll portion 41b is provided with a discharge side connection portion 41c extending toward the outlet side intake passage 92.

  The second compressor housing 42 is provided with a second suction side connection portion 42 a that is attached to the inner peripheral surface of the first suction side connection portion 41 a and that is disposed in the vicinity of the compressor wheel 52. A substantially annular first diffuser portion 42b extending from the second suction side connection portion 42a to the outside in the radial direction is provided on the turbine side in the axial direction of the second suction side connection portion 42a. The connection portion between the second suction side connection portion 42a and the first diffuser portion 42b is formed in a curved shape that is bent outward in the radial direction toward the turbine chamber side in the axial direction. This curved surface shape is a shape along the upper surface shape of the blades of the compressor wheel 52. Further, a second scroll portion 42d having a curved shape that is smoothly connected to the first scroll portion 41b is provided on the axial compressor side in the radially outer portion of the first diffuser portion 42b. The second scroll portion 42d is formed in a curved surface shape that is inclined outward in the radial direction toward the turbine side in the axial direction.

  The third compressor housing 43 is provided with a wheel accommodating portion 43a that faces the second suction side connecting portion 42a in the axial direction and accommodates a part of the compressor wheel 52. A second diffuser portion 43b that is formed of a substantially annular flat plate and is opposed to the first diffuser portion 42b in the axial direction is provided outside the wheel housing portion 43a in the radial direction. A scroll connection portion 43c that is connected to the first scroll portion 41b is provided on the outer side in the radial direction of the second diffuser portion 43b.

  The first turbine housing 44 is provided with a substantially cylindrical first discharge side connection portion 44 a that is connected to the communication exhaust passage 104. On the compressor side in the axial direction of the first discharge side connection portion 44a, a first exhaust flow passage portion 44b extending outward from the first discharge side connection portion 44a in the radial direction is provided. A substantially annular first scroll portion 44c is provided outside the first exhaust passage portion 44b in the radial direction. The first scroll portion 44 c is provided with a suction side connection portion 44 d extending toward the high pressure side exhaust passage 102.

  The second turbine housing 45 is formed in a substantially annular shape. The second turbine housing 45 is provided with a second exhaust passage portion 45a that faces the first exhaust passage portion 44b in the axial direction.

  The bearing housing 46 is provided with a substantially cylindrical portion 46a extending along the axial direction. On the compressor side in the axial direction of the cylindrical portion 46a, a fixing portion 46b fixed to the third compressor housing 43 with a bolt B is provided. A first bearing holding portion 46c that holds the first bearing mechanism 61 is provided inside the fixing portion 46b in the radial direction. A second bearing holding portion 46d for holding the second bearing mechanism 62 is provided on the turbine side in the axial direction of the first bearing holding portion 46c. On the turbine chamber side in the axial direction of the second bearing holding portion 46d, a wheel accommodating portion 46e that forms an end portion on the turbine side in the axial direction of the cylindrical portion 46a and accommodates the turbine wheel 53 is provided. Further, in the cylindrical portion 46a, at the substantially same position in the axial direction as the second bearing holding portion 46d, it extends outward in the radial direction, and the compressor side surface of the first turbine housing 44 and the second turbine housing 45 in the axial direction. The bearing holding part 46f which contacts is provided.

Here, the high-pressure side compressor chamber 70 and the high-pressure side turbine chamber 80 are configured as follows.
That is, the high-pressure side compressor chamber 70 is composed of a suction chamber 71, a wheel storage chamber 72, a diffuser chamber 73, a scroll chamber 74, and a discharge chamber 75 from the intake upstream side.

  The suction chamber 71 is configured by a passage in the first suction side connection portion 41 a of the first compressor housing 41. The wheel storage chamber 72 is configured as a space surrounded in the axial direction and the radial direction by the second suction side connection portion 42 a of the second compressor housing 42 and the wheel storage portion 43 a of the third compressor housing 43. The diffuser chamber 73 is configured as a space surrounded in the axial direction between the first diffuser portion 42 b of the second compressor housing 42 and the second diffuser portion 43 b of the third compressor housing 43. The scroll chamber 74 is formed as a space surrounded by the first scroll portion 41 b of the first compressor housing 41 and the second scroll portion 42 d of the second compressor housing 42. The discharge chamber 75 is constituted by a passage in the discharge side connection portion 41c.

  With the above configuration, the intake air sucked into the suction chamber 71 flows toward the compressor wheel 52 along the axial direction. The air sent out from the compressor wheel 52 is converted from dynamic pressure to static pressure in the diffuser chamber 73 and sent out toward the discharge chamber 75 by the scroll chamber 74. The intake air that has flowed out of the discharge chamber 75 flows into the outlet side intake passage 92.

The high-pressure side turbine chamber 80 includes a suction chamber 81, a scroll chamber 82, an annular exhaust passage chamber 83, a wheel storage chamber 84, and a discharge chamber 85 from the exhaust upstream side.
The suction chamber 81 is configured by a passage in the suction side connection portion 44 d of the first turbine housing 44. The scroll chamber 82 is configured by a passage in the first scroll portion 44 c of the first turbine housing 44. The annular exhaust passage chamber 83 is configured as a space surrounded in the axial direction between the first exhaust passage portion 44 b of the first turbine housing 44 and the second exhaust passage portion 45 a of the second turbine housing 45. The wheel storage chamber 84 is configured as a space surrounded by the compressor side portion of the first discharge side connection portion 44 a of the first turbine housing 44 and the wheel storage portion 46 e of the bearing housing 46. The discharge chamber 85 is configured by a passage in the turbine side portion in the axial direction of the first discharge side connection portion 44 a of the first turbine housing 44.

  With the above configuration, the exhaust gas flowing into the suction chamber 81 flows toward the scroll chamber 82 along the direction perpendicular to the axial direction. The exhaust gas fed into the scroll chamber 82 flows toward the turbine wheel 53 of the wheel storage chamber 84 via the annular exhaust flow channel chamber 83. The exhaust gas sent into the wheel housing chamber 84 flows into the discharge chamber 85 along the axial direction by the rotation of the turbine wheel 53. The exhaust gas flowing out from the discharge chamber 85 flows out into the communication exhaust passage 104.

  By the way, the intake-side supercharging passage 90 connecting the high-pressure supercharger 3 and the low-pressure supercharger 4 of the multistage supercharging device 2 requires five types of passages, that is, the inlet-side intake passage 91 to the bypass passage 95, When this is formed by separate pipes, the arrangement of the pipes becomes complicated, and there is a problem that the multistage supercharger 2 becomes large as a whole apparatus.

  In that respect, in this embodiment, by providing the bypass passage 95 in the housing 40 of the high-pressure supercharger 3 among the above-described passages, the number of pipes is reduced, and the entire multistage supercharger 2 is configured as a whole. The increase in size is suppressed. Details of the structure will be described below with reference to FIGS.

  The first suction side connection part 41a is divided into a first inner connection part 41e and a first outer connection part 41f. The first inner connection portion 41e is located on the radially inner side of the first suction side connection portion 41a, and the second suction side connection portion 42a of the second compressor housing 42 is attached thereto. The first outer connecting portion 41f is located on the outer side in the radial direction of the first suction side connecting portion 41a and is connected to the first scroll portion 41b. The first compressor housing 41 of the housing 40 is formed with a first communication portion 41d that is partitioned by the outer surface of the first inner connection portion 41e and the inner surface of the first outer connection portion 41f and extends in the axial direction. .

  The second suction side connection part 42a is divided into a second inner connection part 42f and a second outer connection part 42g. The second compressor housing 42 is formed with a second communication portion 42e that is partitioned by the outer surface of the second inner connection portion 42f and the inner surface of the second outer connection portion 42g and extends in the axial direction. The radial width H1 of the first communication portion 41d and the radial width H2 of the second communication portion 42e are set to be equal to each other.

  The second inner connection portion 42 f is a portion on the radially inner side of the second suction side connection portion 42 a and is attached to the first inner connection portion 41 e of the first compressor housing 41.

  The second outer connecting portion 42g is located on the outer side in the radial direction of the second suction side connecting portion 42a and is attached to the first outer connecting portion 41f of the first compressor housing 41. The second outer connecting portion 42g is composed of a first diffuser portion 42b and a second scroll portion 42d.

  The second communication part 42e is provided in the first diffuser part 42b. Thus, the passage in the second communication portion 42 e communicates with the diffuser chamber 73. In particular, the passage in the second communication portion 42 e communicates with the radially inner side of the diffuser chamber 73.

  Here, the bypass passage 95 includes a first communication portion 41d and a second communication portion 42e. That is, the bypass passage 95 is configured by a space between the outer surfaces of the first inner connection portion 41e and the second inner connection portion 42f, and the inner surfaces of the first outer connection portion 41f and the second outer connection portion 42g in the radial direction. Yes. As a result, the bypass passage 95 communicates with the diffuser chamber 73. The first communication part 41d and the second communication part 42e are provided in an annular shape centering on the axis. With these configurations, the bypass passage 95 is provided in such a manner as to surround the suction chamber 71 from the outside in the radial direction.

  As shown in FIG. 3A, the first inner connecting portion 41e and the first outer connecting portion 41f are connected to each other by four first connecting ribs 41g provided at substantially equal angular intervals in the circumferential direction. Yes. Although not shown, the second inner connecting portion 42f and the second outer connecting portion 42g are connected to each other by four second connecting ribs provided at substantially equal angular intervals in the circumferential direction. The first connection rib 41g and the second connection rib are provided in a state of being separated from each other in the axial direction, and the second connection rib is provided closer to the turbine side in the axial direction than the first connection rib 41g.

  As shown in FIG.3 (b), the 1st connection rib 41g is formed in the shape which inclines in the circumferential direction with respect to the turbine side of an axial direction. The same applies to the second connection rib. The first connection rib 41g and the second connection rib are formed so as to have shapes along the flow direction of the intake air flowing through the first communication portion 41d and the second communication portion 42e, respectively.

  As shown in FIG. 4, an intake side switching valve 110 is provided in the first communication part 41d. The intake side switching valve 110 includes 12 circular arc-shaped valve bodies 111 arranged in the circumferential direction, and a shaft 112 that is inserted into each valve body 111 and that allows the valve body 111 to rotate. The valve body 111 and the actuator mechanism 113 for driving the shaft 112 are configured. The actuator mechanism 113 includes a link mechanism 114 provided on each shaft 112, a ring body 115 that connects the link mechanism 114 to each other, and an actuator body 116 that allows the ring body 115 to move in the circumferential direction. Yes. The actuator body 116 is driven by a valve opening / closing command signal from the control device of the engine 1.

  As shown in FIG. 4 (a), when the intake side switching valve 110 is closed, each valve element 111 is controlled in a direction along the radial direction. Specifically, the actuator body 116 that receives the valve closing command signal is driven to move the ring body 115 in the circumferential direction. As the ring body 115 moves in the circumferential direction, each link mechanism 114 acts to rotate each shaft 112. Thereby, each valve body 111 attached to each shaft 112 rotates as the shaft 112 rotates. In this case, each valve body 111 rotates so as to be in a direction along the radial direction.

  As shown in FIG. 4B, when the intake-side switching valve 110 is opened, each valve body 111 is similarly controlled in a manner that is in a direction along the axial direction. As described above, the intake side switching valve 110 communicates and blocks the passages in the first communication portion 41d and the second communication portion 42e (that is, the low pressure side intake passage 93).

  Next, the structure of the low-pressure supercharger 4 will be described with reference to FIG. Note that the high-pressure supercharger 3 and the low-pressure supercharger 4 have substantially the same structure, and therefore, common members are denoted by “A” at the end of the reference numerals and description thereof is omitted. Hereinafter, the first compressor housing 121 to the third compressor housing 123 having different configurations will be described.

  As shown in FIG. 5, the housing 120 of the low-pressure supercharger 4 is provided with a first compressor housing 121 to a third compressor housing 123 that form a low-pressure side compressor chamber 130.

  The first compressor housing 121 is provided with a substantially cylindrical first suction side connection portion 121 a that is connected to the inlet side intake passage 91. On the turbine side in the axial direction of the first suction side connection portion 121a, a substantially annular first scroll portion 121b extending from the first suction side connection portion 121a to the outside in the radial direction is provided. The first scroll portion 121b is provided with a discharge side connection portion 121c extending toward the low pressure side intake passage 93.

  The second compressor housing 122 is provided with a second suction-side connection portion 122a that is attached to the inner peripheral surface of the first suction-side connection portion 121a and is disposed close to the compressor wheel 52A. On the turbine side in the axial direction of the second suction side connection portion 122a, a curved second scroll portion 122b extending outward in the radial direction from the second suction side connection portion 122a toward the turbine side in the axial direction is provided. Yes. The opposing surface 122c facing the compressor wheel 52A in the second scroll portion 122b is formed in a curved shape that bends radially outward toward the turbine chamber side in the axial direction. The curved surface shape of the facing surface 122c is formed in a shape along the upper surface shape of the blades of the compressor wheel 52A.

  The third compressor housing 123 is provided with a wheel accommodating portion 123a that faces the second suction side connecting portion 122a in the axial direction and accommodates a part of the compressor wheel 52A. A scroll connection portion 123b connected to the first scroll portion 121b is provided outside the wheel housing portion 123a in the radial direction.

Here, the low-pressure side compressor chamber 130 is configured as follows.
That is, the low-pressure side compressor chamber 130 is composed of a suction chamber 131, a wheel storage chamber 132, a scroll chamber 133, and a discharge chamber 134 from the intake upstream side. That is, the low-pressure side compressor chamber 130 has a diffuserless configuration in which the wheel storage chamber 132 and the scroll chamber 133 are in direct communication.

  The suction chamber 131 is configured by a passage in the first suction side connection part 121 a of the first compressor housing 121. The wheel storage chamber 132 is configured as a space surrounded in the axial direction and the radial direction by the second suction side connection portion 122 a and the opposing surface 122 c of the second compressor housing 122 and the wheel storage portion 123 a of the third compressor housing 123. ing. The scroll chamber 133 is formed as a space surrounded by the first scroll part 121 b of the first compressor housing 121 and the second scroll part 122 b of the second compressor housing 122. Further, the discharge chamber 134 is constituted by a passage in the discharge-side connecting portion 121c.

  With the above configuration, the intake air sucked into the suction chamber 131 flows toward the compressor wheel 52A along the axial direction. The air sent out from the compressor wheel 52 </ b> A is sent out toward the discharge chamber 134 by the scroll chamber 133. The intake air flowing out from the discharge chamber 134 flows out into the low pressure side intake passage 93.

According to the present embodiment, the following effects can be achieved.
(1) According to the present embodiment, the first communication portion 41 d and the second communication portion 42 e that configure the bypass passage 95 are provided in the housing 40 of the high-pressure supercharger 3. Thereby, the connection piping which connects a supercharger separately from each other can be omitted. Therefore, in the multistage supercharger 2, it is possible to suppress an increase in the size of the multistage supercharger 2 as a whole as compared with the case where the housing 40 and the pipes constituting the bypass passage 95 are separately provided. become able to.

  An intake side switching valve 110 is provided in the first communication part 41d. Thereby, the external channel | path for connecting the intake side switching valve 110 and the 1st communication part 41d is omissible. Therefore, compared to a configuration in which the intake side switching valve 110 is provided in a pipe different from the first communication portion 41d, the overall size of the multistage supercharging device 2 can be suppressed. .

  In particular, a bypass passage 95 is formed in the housing 40 of the high-pressure supercharger 3 and includes the first communication portion 41 d and the second communication portion 42 e and communicates with the diffuser chamber 73. Therefore, since the bypass passage 95 communicates with the diffuser chamber 73, the intake air from the bypass passage 95 flows into the diffuser chamber 73, so that the pressure is converted from dynamic pressure to static pressure. Therefore, the supercharging characteristic of the multistage supercharging device 2 can be improved.

  (2) According to the present embodiment, the first suction side connection portion 41a of the first compressor housing 41 constituting the suction chamber 71 in the housing 40 of the high-pressure supercharger 3 is provided in a substantially cylindrical shape, and the first communication is provided. Both the portion 41d and the second communication portion 42e are provided as a space shape extending in the axial direction. Accordingly, the pipe connected to the first suction side connection portion 41 a serves as both the communication intake passage 94 and the bypass passage 95. As a result, it becomes possible to reduce the number of pipes used for the multistage supercharger 2, and to suppress the increase in size of the multistage supercharger 2 as a whole.

  (3) Since the bypass passage 95 constituted by the first communication portion 41d and the second communication portion 42e communicates with the diffuser chamber 73 without being bent, the low pressure supercharger 4 through the communication intake passage 94 is connected. The intake air discharged toward the high pressure supercharger 3 can be efficiently supplied to the diffuser chamber 73. Therefore, an increase in turbulence of intake air in the bypass passage 95 can be suppressed.

  (4) The intake air discharged from the low-pressure supercharger 4 to the high-pressure supercharger 3 via the communication intake passage 94 includes a swirl flow by the rotation of the compressor wheel 52A. That is, the air flows toward the high-pressure supercharger 3 while turning in the communication intake passage 94. In that respect, according to the present embodiment, the first communication portion 41d and the second communication portion 42e are provided in an annular shape surrounding the suction chamber 71 from the radial direction. An air flow including a swirling flow is formed. Then, the air flow is sent into the diffuser chamber 73 along the inner peripheral surface of the first communication portion 41 d and the inner peripheral surface of the second communication portion 42 e constituting the inner wall surface of the bypass passage 95. Therefore, the intake air that is the air flow including the swirl flow can be efficiently supplied to the diffuser chamber 73.

  (5) According to this embodiment, the opening / closing operation of the intake side switching valve 110 is closed when the low-pressure supercharger 4 is stopped, and is opened when the low-pressure supercharger 4 is driven. . Therefore, when the low-pressure supercharger 4 is in a stopped state, the bypass passage 95 and the diffuser chamber 73 are blocked, so that the intake air from the low-pressure supercharger 4 flows toward the compressor wheel 52 of the high-pressure supercharger 3. become. Therefore, supercharging of the high-pressure supercharger 3 can be performed efficiently. On the other hand, when the low-pressure supercharger 4 is in a driving state, the bypass passage 95 and the diffuser chamber 73 are in communication with each other, so that the dynamic pressure of the intake air from the low-pressure supercharger 4 is converted into a static pressure, and the swirl flow The intake air containing the air can be efficiently supplied to the diffuser chamber 73.

  (6) According to the present embodiment, the second communication portion 42 e is provided so as to communicate with the inner side in the radial direction of the diffuser chamber 73. Therefore, the intake air passing through the bypass passage 95 is supplied to the diffuser chamber 73, whereby the flow velocity is reduced and the static pressure is improved. As a result, since the diffuser chamber 73 also serves as the diffuser chamber of the low-pressure supercharger 4, the diffuser chamber can be omitted in the low-pressure supercharger 4. Therefore, it is possible to reduce the size of the low-pressure side compressor chamber 130 of the low-pressure supercharger 4, and consequently, it is possible to suppress an increase in size of the multistage supercharger 2 as a whole.

  (7) According to the present embodiment, the first connection rib 41g and the second connection rib are both provided in a shape along the flow direction of the intake air. Accordingly, it is possible to reduce the loss of the intake air passing through the first connection rib 41g and the second connection rib, and to efficiently supply the intake air from the bypass passage 95 to the diffuser chamber 73.

(Other embodiments)
The specific configuration of the supercharger of the present invention and the multistage supercharger including the same is not limited to the configuration illustrated in the above-described embodiment, and can be modified as follows, for example. Further, the following modified examples are not applied only to the above-described embodiment, but can be applied to a case where different modified examples are combined with each other.

  In the present embodiment, the housing 40 includes three housings, the first compressor housing 41 to the third compressor housing 43, as the housing forming the compressor chamber 70, but the number of housings is not limited to this. Absent. For example, the first compressor housing 41 and the second compressor housing 42 can be configured as a single member. Also, the first compressor housing 41 to the third compressor housing 43 can be configured as a single member.

  In the present embodiment, the first communication portion 41d and the second communication portion 42e are each provided in an annular shape, but the shape of the first communication portion 41d and the second communication portion 42e (the bypass passage 95) is It is not limited to this. For example, as shown in FIG. 6, the shapes of the first communication portion 41 d and the second communication portion 42 e can be configured by a plurality of arc shapes. Thereby, the effect according to the effect (1)-(3), (5) and (7) of the said embodiment can also be show | played. In this case, the intake side switching valve 110 is provided in the arc shape. In addition, by making the first communication portion 41d and the second communication portion 42e communicate with the inner side in the radial direction of the diffuser chamber 73, it is possible to achieve an effect according to the effect (6) of the above embodiment.

  In the present embodiment, the intake side switching valve 110 is provided in the first communication portion 41d, but the position where the intake side switching valve 110 is provided is not limited to this. Since the intake side switching valve 110 only needs to have a structure provided in the bypass passage 95, the intake side switching valve 110 may be provided in the second communication portion 42e.

  In the present embodiment, the first connection rib 41g and the second connection rib are provided in an aspect that is separated in the axial direction, but the first connection rib 41g and the second connection rib are connected to each other in the axial direction. Can also be provided. In this case, it is desirable to form a smooth slope from the first connection rib 41g to the second connection rib. In other words, it is desirable that the first connection rib 41g and the second connection rib be an integral connection rib and be inclined in the circumferential direction toward the turbine side in the axial direction.

  -In this embodiment, although the 1st communication part 41d and the 2nd communication part 42e were the structures provided in the aspect along the axial direction, the aspect of the 1st communication part 41d and the 2nd communication part 42e is to this There is no limit. For example, the first communication portion 41d and the second communication portion 42e can be configured to bend in the radial direction on the intake upstream side of the communication portions 41d and 42e.

  In the present embodiment, the first communication part 41d and the second communication part 42e communicate with the inner side in the radial direction of the diffuser chamber 73, but the first communication part 41d and the second communication part 42e are the diffuser chamber. It can also be set as the aspect connected to the center or outer side of 73 radial direction. With this configuration, it is possible to achieve the effects according to the effects (1) and (3) to (5) of the above embodiment. In this case, the intake side switching valve 110 is provided in the first communication part 41d and the second communication part 42e.

  In the present embodiment, the bypass passage 95 is provided inside the high-pressure supercharger 3 of the multistage supercharger 2, but the supercharger provided with the bypass according to the present invention is applied to this device. It is not limited to only. For example, the supercharger can be used as one of a plurality of superchargers having the same compression ratio. Thereby, the effect according to the effect of this embodiment can also be produced.

-In the said embodiment, although applied to the multistage supercharger of a diesel engine, you may apply to the multistage supercharger of a gasoline engine, for example.
-Although it applied to the supercharger provided with several superchargers like the multistage supercharger 2 in the said embodiment, it can also be used, for example as a supercharger single-piece | unit. In this case, the bypass passage (bypass) of the supercharger can be applied as an introduction portion for PCV flow rate and an introduction portion for EGR gas.

  B ... Bolt, 1 ... Engine, 2 ... Multistage supercharger, 3 ... High pressure supercharger, 4 ... Low pressure supercharger, 11 ... Combustion chamber, 22 ... Intake manifold, 23 ... Intake passage, 24 ... Air cleaner, 25 DESCRIPTION OF SYMBOLS ... Intercooler, 26 ... Diesel throttle, 32 ... Exhaust manifold, 33 ... Exhaust passage, 34 ... Exhaust purification device, 40 ... Housing, 41 ... First compressor housing, 41a ... First suction side connection (suction side connection) , 41b ... first scroll part, 41c ... discharge side connection part, 41d ... first communication part, 41e ... first inner connection part (inner connection part), 41f ... first outer connection part (outer connection part), 42 ... 2nd compressor housing, 42a ... 2nd suction side connection part (suction side connection part), 42b ... 1st diffuser part, 42d ... 2nd scroll part, 42e ... 2nd communication part, 4 f ... 2nd inner side connection part (inner side connection part), 42g ... 2nd outer side connection part (outer side connection part), 43 ... 3rd compressor housing, 43a ... Wheel accommodating part, 43b ... 2nd diffuser part, 43c ... Scroll connection 44a, 44A ... first turbine housing, 44a ... first discharge side connection, 44b ... first diffuser part, 44c ... first scroll part, 44d ... suction side connection, 45, 45A ... second turbine housing, 45a ... second diffuser portion, 46, 46A ... bearing housing, 46a ... cylindrical portion, 46b ... fixed portion, 46c ... first bearing holding portion, 46d ... second bearing holding portion, 46e ... wheel housing portion, 46f ... bearing holding 50, bearing chamber, 51, 51A ... rotor shaft, 52, 52A ... compressor wheel, 53, 53A ... turbine 60, 60A ... bearing mechanism, 61, 61A ... first bearing mechanism, 62, 62A ... second bearing mechanism, 70 ... high pressure side compressor chamber, 71 ... suction chamber, 72 ... wheel housing chamber, 73 ... diffuser chamber, 74 ... Scroll chamber, 75 ... Discharge chamber, 80, 80A ... Turbine chamber, 81, 81A ... Suction chamber, 82, 82A ... Scroll chamber, 83, 83A ... Annular exhaust passage chamber, 84, 84A ... Wheel housing chamber, 85 85A ... Discharge chamber, 90 ... Suction side supercharging passage (connection passage), 91 ... Inlet side supercharging passage, 92 ... Outlet side supercharging passage, 93 ... Low pressure side supercharging passage, 94 ... Communication supercharging passage, DESCRIPTION OF SYMBOLS 95 ... Detour passage (detour), 100 ... Exhaust side supercharging passage, 101 ... Inlet side exhaust passage, 102 ... High pressure side exhaust passage, 103 ... Low pressure side exhaust passage, 104 ... Communication exhaust passage, 105 ... Outlet side exhaust Aisle, 106 ... Exhaust side switching valve, 110 ... Intake side switching valve, 111 ... Valve element, 112 ... Shaft, 113 ... Actuator mechanism, 114 ... Link mechanism, 115 ... Ring body, 116 ... Actuator body, 120 ... Housing, 121 ... First Compressor housing, 121a ... first suction side connection portion, 121b ... first scroll portion, 121c ... discharge side connection portion, 122 ... second compressor housing, 122a ... second suction side connection portion, 122b ... second scroll portion, 122c Reference surface, 123 ... third compressor housing, 123a ... wheel accommodating portion, 130 ... compressor chamber, 131 ... suction chamber, 132 ... wheel accommodating chamber, 133 ... scroll chamber, 134 ... discharge chamber.

Claims (8)

In a supercharger comprising a housing in which a compressor chamber for compressing air is formed, and a compressor wheel provided in the compressor chamber,
The compressor chamber is provided with a suction chamber that supplies air flowing into the housing toward the compressor wheel, and a diffuser chamber that decelerates the flow rate of air sent from the compressor wheel.
In the housing, a bypass route is formed in which the air that flows into the diffuser chamber and flows into the housing bypasses the compressor wheel and flows to the diffuser chamber, and the open / close state is switched in the bypass route. A turbocharger characterized in that a switching valve is provided. The turbocharger according to claim 1, wherein
The housing is provided with a suction side connection portion that constitutes the suction chamber,
The suction side connection portion is provided with an inner connection portion that defines the suction chamber, and an outer connection portion that surrounds the inner connection portion from the rotational radial direction of the compressor wheel,
The detour is configured by a space formed between an outer surface of the inner connection portion and an inner surface of the outer connection portion. The turbocharger according to claim 2,
The suction side connection portion is provided in a mode extending in a rotation axis direction of the compressor wheel,
The detour is provided in a form extending in the rotation axis direction. In the supercharger according to claim 2 or claim 3,
The detour is formed in an annular shape surrounding a rotation shaft of the compressor wheel. In the supercharger as described in any one of Claims 1-4,
The switching valve includes a plurality of valve bodies arranged at predetermined intervals in a rotation circumferential direction of the compressor wheel, and a shaft capable of rotating the plurality of valve bodies, and the rotation of the plurality of valve bodies The supercharger characterized by switching the open / closed state of the detour by. In a supercharging device comprising a plurality of superchargers,
The supercharger provided with the supercharger as described in any one of Claims 1-5 as one supercharger of these superchargers. In a multistage supercharger comprising a high-pressure supercharger having a small capacity, a low-pressure supercharger having a larger capacity than the high-pressure supercharger, and a connecting passage connecting the high-pressure supercharger and the low-pressure supercharger to each other.
The compressor chamber of the high pressure supercharger and the compressor chamber of the low pressure supercharger are connected in series with each other in the air flow direction, and the high pressure supercharger is downstream of the low pressure supercharger in the air flow direction. Provided in
A multistage supercharger comprising the supercharger according to any one of claims 1 to 5 as the high-pressure supercharger. In the multistage supercharging device according to claim 7,
The multistage turbocharger, wherein the switching valve is closed when the low-pressure supercharger is stopped, and is opened when the low-pressure supercharger is driven.

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