JP2010185314A - Supercharging control device - Google Patents

Abstract

A turbocharging pressure can be increased by avoiding occurrence of surging even in a surging region.
A branch pipe 18 is connected in parallel to an intake pipe 17 downstream of a compressor section 20 of a turbocharger 19, and an electric rotary valve 36 is provided in the middle of the branch pipe 18. When the electric rotary valve 36 is operated, intake pulsation occurs in the gas supply passage upstream of the electric rotary valve 36. An intercooler 41 is provided in the parallel part 171 of the intake pipe 17 with respect to the branch pipe 18, and an electromagnetic switching valve 42 is provided in a branch part between the parallel part 171 upstream of the intercooler 41 and the intake pipe 17. . When the electromagnetic switching valve 42 is demagnetized, the air sent out from the compressor unit 20 of the turbocharger 19 can flow into the parallel unit 171 and cannot flow through the intercooler 41. In the engine low speed region, the electromagnetic switching valve 42 is demagnetized and the electric rotary valve 36 is operated.
[Selection] Figure 1

Description

  The present invention relates to a supercharging control device that supplies air from a turbocharger via a gas supply passage.

  As a supercharger that increases the intake efficiency of an internal combustion engine, an exhaust-drive supercharger (turbocharger) that performs supercharging using the flow of exhaust flow is frequently used (for example, see Patent Documents 1 and 2). ). Among turbochargers, there is a variable nozzle type turbocharger in which a vane provided on the turbine side is opened and closed to adjust the flow rate of exhaust gas, and the supercharging pressure can be adjusted by adjusting the flow rate.

If the pressure ratio between the upstream side and the downstream side of the compressor in the turbocharger becomes too high, surging occurs that the intake air flows backward.
In the invention disclosed in Patent Document 2, a turbocharger that supplies air to the engine and an electric supercharger are provided side by side. Before entering the surging region, control is performed to return a part of the intake air to the recirculation piping to make use of the power generation function of the electric supercharger, and surging is avoided by such control. In this case, it is necessary to prevent the intake air that is returned to the circulation pipe from returning to the turbocharger side. For this reason, in Patent Document 2, a check valve is provided downstream of the compressor portion of the turbocharger.

Japanese Patent Laid-Open No. 4-1422 JP 2007-77854 A

  However, in the method of returning a part of the intake air to the recirculation pipe before entering the surging area, the surging is not canceled when the supercharging state enters the surging area. It is not expected to increase the supercharging pressure at the plant.

  An object of the present invention is to avoid the occurrence of surging even in the surging region and to increase the supercharging pressure.

  A supercharging control device according to a first aspect of the present invention is provided on the gas supply passage, and is provided with a supercharger that pressurizes and supplies gas, and is provided downstream of the supercharger in the gas supply passage. An intake pulsation generating means for generating an intake pulsation with a period earlier than a surging period in the gas supply passage on the downstream side of the turbocharger, and the supercharged state of the supercharger may be located in a surging region The intake pulsation generating means generates intake pulsation when the supercharged state of the supercharger is at least in the surging region.

  While the time-average supercharging state is located in the surging area, the actual supercharging state repeatedly straddles the boundary between the surging area and the non-surging area at a period earlier than the surging period. The supercharged state is represented by the flow rate of air passing through the turbocharger and the pressure ratio between the upstream side and the downstream side of the turbocharger with respect to the air supply passage. If the supercharging state repeatedly crosses the boundary between the surging region and the non-surging region, surging does not occur even if the supercharging state enters the surging region. In this case, it is desirable that the repetition period when the supercharging state repeatedly crosses the boundary between the surging area and the non-surging area is shorter than the surging period.

In addition, since patent document 1 does not describe controlling so that the supercharging state by a supercharger may be located in a surging area | region, it is not contained in Claim 1.
In a preferred example, the supercharger is a turbocharger provided in an internal combustion engine, and the intake pulsation generating means is provided in a gas supply passage extending from the turbocharger to a combustion chamber of the internal combustion engine. It has been.

  In a preferred example, the engine comprises a rotation speed detection means for detecting the rotation speed of the internal combustion engine and a control means for controlling the intake pulsation generation means, wherein the control means detects the rotation speed detected by the rotation speed detection means. When is less than a preset reference rotational speed, the intake pulsation generating means performs control to generate intake pulsation.

The supercharging pressure can be increased while avoiding the occurrence of surging when the engine is in a low engine speed state.
In a preferred example, a supercharging state specifying means for specifying a supercharging state by the supercharger and a control means for controlling the intake pulsation generating means are provided, and the control means is specified by the supercharging state specifying means. Based on the supercharged state, the control for generating the intake pulsation by the intake pulsation generating means and the control for not generating the intake pulsation are switched.

The supercharging state specification may be a detection of a supercharging state or an estimation thereof.
In a preferred example, the apparatus includes a supercharging state adjusting unit that adjusts a supercharging state by the supercharger, and a control unit that controls the intake pulsation generating unit, wherein the control unit controls the supercharging state adjusting unit. And the control function which adjusts so that the supercharging state by the said supercharger may be located in a surging area | region is provided.

  In a preferred example, the gas supply passage branches in parallel to a first passage and a second passage, and a first supply state in which gas can be supplied from the supercharger only to the first passage, Supply switching means capable of switching to a second supply state in which intake air can be supplied from the turbocharger is provided only in the second passage, and the intake pulsation generating means is provided in the first passage. When the intake pulsation generating means generates the intake pulsation, the supply switching means is controlled to be switched to the first supply state.

  If the internal combustion engine is in the first supply state when the engine speed is low and the second supply state is when the internal combustion engine is at the high engine speed, the intake pulsation generating means is set to the pulsation generating state to supercharge without causing surging. be able to.

In a preferred example, an intercooler is provided in the second passage, and the intercooler cools the air flowing through the second passage.
When the internal combustion engine is at a high speed, the supercharging pressure is increased and the intake air temperature is increased. If the internal combustion engine is in the second supply state when the engine speed is high, the intake air at the time of the high engine speed is cooled by the intercooler, and a decrease in air supply efficiency is avoided.

  In a preferred example, the intake pulsation generating means is an open / close switching valve that is switched between an open state in which gas can flow and a closed state in which gas cannot flow, and is repeatedly switched between the open state and the closed state. Inspiratory pulsation is generated.

The open / close switching valve is convenient for setting the repetition cycle (open / close cycle) appropriately.
In a preferred example, the intake pulsation generating means is a Roots pump.
The non-turbo type pump is in a state in which air cannot flow when the operation is stopped, and the non-turbo type pump is stopped when the air supply passage branches in parallel to the first passage and the second passage. If it will be in a state, the gas distribution in the 1st passage can be intercepted.

In a preferred example, the supercharger is a twin entry turbine type turbocharger having a pair of scroll passages.
In a preferred example, there is provided switching means capable of switching communication / blocking between the pair of scroll passages.

  The present invention has an excellent effect that the supercharging pressure can be increased by avoiding the occurrence of surging even in the surging region.

1 shows a first embodiment, and (a) is an overall configuration diagram of an internal combustion engine. FIG. (B) is a graph for explaining supercharging control. (A) is a sectional side view of the electric rotary valve 36. (B) is the sectional view on the AA line of Fig.2 (a). FIG. 3 is a side sectional view of the turbocharger 19. (B) is the BB sectional drawing of Fig.3 (a). Control block diagram. The flowchart showing a surging prevention control program. The whole internal combustion engine block diagram which shows 2nd Embodiment. A 3rd embodiment is shown and (a) is a whole lineblock diagram of an internal-combustion engine. (B) is sectional drawing of the turbocharger 19A.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1A, a diesel engine 10 (internal combustion engine) includes a plurality of pistons (not shown) and a plurality of combustion chambers 11A, 11B, 11C, and 11D defined by the pistons. A fuel injection nozzle 13 is attached to each of the combustion chambers 11A, 11B, 11C, and 11D on a cylinder head 12 connected to a cylinder (not shown) that forms the combustion chambers 11A, 11B, 11C, and 11D. The fuel (light oil) is supplied to the fuel injection nozzle 13 via the fuel pump 14 and the common rail 15, and the fuel injection nozzle 13 injects the fuel into each combustion chamber 11A, 11B, 11C, 11D.

  An intake manifold 16 is connected to the cylinder head 12. An intake pipe 17 is connected to the intake manifold 16, and a compressor unit 20 of a turbocharger 19 is provided in the middle of the intake pipe 17. The turbocharger 19 is a variable nozzle type turbocharger that is operated by an exhaust gas flow. Air in the intake pipe 17 upstream from the compressor unit 20 of the turbocharger 19 is sucked into the compressor unit 20 and sent out. .

  An exhaust manifold 23 is connected to the cylinder head 12. An exhaust pipe 24 is connected to the exhaust manifold 23. Exhaust gas discharged from the combustion chambers 11A, 11B, 11C, and 11D is released to the atmosphere via the exhaust manifold 23, the turbine portion 21 of the turbocharger 19, and the exhaust pipe 24.

  FIG. 3A shows the internal structure of the turbocharger 19. The compressor unit 20 includes a compressor housing 30 and a compressor wheel 27 fixed to the rotor shaft 25, and the turbine unit 21 includes a turbine housing 31 and a turbine wheel 26 fixed to the rotor shaft 25. The compressor housing 30 and the turbine housing 31 are connected via the center housing 22.

  Exhaust gas discharged from the combustion chambers 11A, 11B, 11C, and 11D to the exhaust pipe 24 is sent to the scroll passage 311 and the swirl passage 312 in the turbine housing 31, and blown to the blades 261 of the turbine wheel 26. The rotor shaft 25 and the compressor wheel 27 rotate integrally. The rotating compressor wheel 27 introduces air in the intake pipe 17 upstream from the compressor section 20 into the compressor passage 301 in the compressor housing 30 and sends it out to the intake pipe 17 downstream from the compressor section 20. A plurality of nozzle vanes 29 are arranged in the middle of the turning passage 312.

  As shown in FIG. 3B, the nozzle vane 29 is rotatably supported by the nozzle ring 28. The nozzle vane 29 can change the flow path cross-sectional area between the adjacent nozzle vanes 29.

  As shown in FIG. 3A, an arm 37 is fixed to a support shaft 48 that can rotate with respect to the nozzle ring 28, and the unison ring 32 is engaged with the arm 37 so as not to be detached. . A support shaft 33 is rotatably supported on the center housing 22, and a drive arm 34 is fixed to one end of the support shaft 33. The drive arm 34 is engaged with the unison ring 32, and when the drive arm 34 rotates about the support shaft 33, the unison ring 32 rotates.

  The drive lever 35 fixed to the other end of the support shaft 33 is rotated about the support shaft 33 by the operation of an actuator (not shown). When the drive lever 35 is rotated, the drive arm 34 and the unison ring 32 are rotated, and the nozzle vane 29 is rotated. That is, the vane opening degree is changed. Increasing the vane opening results in a decrease in turbine rotational speed, and the air flow rate decreases. Decreasing the vane opening results in an increase in turbine rotation speed and an increase in air flow rate.

  As shown in FIG. 1A, an air flow meter 43 is provided in the intake pipe 17 upstream of the compressor unit 20 of the turbocharger 19. The air flow meter 43 detects the flow rate F of air flowing through the intake pipe 17 upstream from the compressor unit 20. The intake manifold 16 is provided with a pressure detector 44. The pressure detector 44 detects the pressure in the intake manifold 16 (supercharging pressure P1). Information on the air flow rate F detected by the air flow meter 43 and information on the supercharging pressure P1 detected by the pressure detector 44 are sent to the control computer C.

An atmospheric pressure detector 45 is signal-connected to the control computer C. Detection information of the atmospheric pressure Po obtained by the atmospheric pressure detector 45 is sent to the control computer C.
Surging in the turbocharger 19 is a phenomenon in which the air flow separates from the blades 271 of the compressor wheel 27 (see FIG. 3A) and the air flows backward at the separation portion. FIG. 1B is a graph showing the presence or absence of surging. The horizontal axis in the graph of FIG. 1B represents the air flow rate F, and the vertical axis represents the ratio P1 / Po (supercharging state) between the supercharging pressure P1 and the atmospheric pressure Po. Region E represents a non-surging region where no surging occurs, and region G represents a surging region where surging occurs. A curve L represents a boundary between the non-surging region E and the surging region G.

The atmospheric pressure detector 45, the pressure detector 44, and the control computer C constitute supercharging state specifying means for specifying the supercharging state by the turbocharger 19.
The operating line K is a line indicating the transition of the supercharging state by the turbocharger 19, and the supercharging when the engine speed increases as the distance from the intersection of the vertical axis and the horizontal axis in FIG. Indicates the state. In the present embodiment, as shown by the operation line K in FIG. 1B, the turbocharger 19 has a high supercharging rate so that the supercharging state is within the surging region G when the engine is running at a low speed. Drive.

  As shown in FIG. 1A, a branch pipe 18 is connected in parallel to the intake pipe 17 downstream of the compressor unit 20 of the turbocharger 19, and an electric rotary valve 36 is provided in the middle of the branch pipe 18. It has been. The intake pipe 17 and the branch pipe 18 constitute a gas supply passage from the turbocharger 19 to the combustion chambers 11A, 11B, 11C, and 11D.

  FIG. 2A shows the internal structure of the electric rotary valve 36 as intake pulsation generating means. The electric rotary valve 36 includes a variable speed electric motor 38, a cylindrical valve body 39 fixed to an output shaft 381 of the electric motor 38, and a valve housing 40 that rotatably accommodates the valve body 39. An inlet 401 and an outlet 402 are formed in the peripheral portion of the valve housing 40, and a plurality of valve holes 391 are formed in the cylindrical valve body 39 so as to be connectable to the inlet 401 and the outlet 402. When the valve body 39 rotates, one of the plurality of valve holes 391 is intermittently connected to the inlet 401 and another one of the plurality of valve holes 391 is intermittently connected to the outlet 402. When one of the plurality of valve holes 391 is connected to the inlet 401, another one of the valve holes 391 is connected to the outlet 402. In this state, air in the branch pipe 18 upstream from the electric rotary valve 36 flows to the branch pipe 18 downstream from the electric rotary valve 36 via the inlet 401, the cylindrical valve body 39 and the outlet 402.

The electric rotary valve 36 is an open / close switching valve that can be switched between an open state in which gas can flow and a closed state in which gas cannot flow.
As shown in FIG. 1A, the electric motor 38 of the electric rotary valve 36 that is an open / close switching valve is subjected to rotation control by the control computer C.

  An intercooler 41 is provided in the parallel part 171 of the intake pipe 17 with respect to the branch pipe 18, and an electromagnetic switching valve 42 is provided in a branch part between the parallel part 171 upstream of the intercooler 41 and the branch pipe 18. . When the electromagnetic switching valve 42 is excited, the air sent out from the compressor unit 20 of the turbocharger 19 can flow through the intercooler 41 and cannot flow into the branch pipe 18. When the electromagnetic switching valve 42 is demagnetized, the air sent out from the compressor unit 20 of the turbocharger 19 can flow into the branch pipe 18 and cannot flow through the intercooler 41. The demagnetization state of the electromagnetic switching valve 42 is a first supply state in which air sent from the compressor unit 20 is supplied only to the branch pipe 18 (first passage), and the excitation state of the electromagnetic switching valve 42 is from the compressor unit 20. This is a second supply state in which the delivered air is supplied only to the parallel part 171 (second passage).

  The electromagnetic switching valve 42 has a first supply state in which air can be supplied from the turbocharger 19 only to the first passage (branch pipe 18), and air from the turbocharger 19 only to the second passage (parallel portion 171). Is a supply switching means capable of switching to a second supply state capable of supplying. The electromagnetic switching valve 42 is subjected to excitation / demagnetization control by the control computer C.

A throttle valve 47 is provided in the middle of the intake pipe 17. The throttle valve 47 is for adjusting the flow rate of air sent to the combustion chambers 11A, 11B, 11C, and 11D.
A crank angle detector 46 is signal-connected to the control computer C. The crank angle detector 46 detects a rotation angle (crank angle) of a crankshaft (not shown). The crank angle information detected by the crank angle detector 46 is sent to the control computer C. The control computer C calculates the engine speed N based on the crank angle information detected by the crank angle detector 46. The control computer C and the crank angle detector 46 constitute rotation speed detection means for detecting the rotation speed of the internal combustion engine.

  The control computer C performs the anti-surging control based on the anti-surging control program shown in the flowchart of FIG. Hereinafter, the surging prevention control will be described based on the flowchart of FIG.

  The control computer C takes in information on the atmospheric pressure Po obtained by the atmospheric pressure detector 45, information on the supercharging pressure P1 obtained by the pressure detector 44, and information on the air flow rate F obtained by the air flow meter 43. At the same time, the engine speed N is calculated (step S1). The control computer C compares the engine rotational speed N with a preset reference rotational speed No (step S2).

  The reference rotational speed No is set to a rotational speed at which surging is assumed not to occur as the engine rotational speed N increases. Specifically, in FIG. 1 (b), as the engine speed N rises, it proceeds along the operating line K along the direction away from the origin, and exceeds the boundary L when the engine speed N exceeds a certain speed. To enter the non-surging area E on the right side. Thus, the engine speed N estimated to enter the non-surging region beyond the boundary L is set as the reference speed No.

  When the engine speed N is equal to or higher than the reference speed No (YES in step S2), the control computer C sets the electromagnetic switching valve 42 to the second supply state and does not operate the electric rotary valve 36 (pulsation generation stop state) ) Perform control (step S3). Thereby, the air sent out from the turbocharger 19 is sent to the intercooler 41.

  Then, the control computer C performs normal supercharging control based on the ratio P1 / Po between the atmospheric pressure Po and the supercharging pressure P1 and the air flow rate F (step S4). In normal supercharging control, the supercharging state (hereinafter referred to as supercharging state (P1 / Po, F)) represented by a set (P1 / Po, F) of the ratio P1 / Po and the air flow rate F is not. As shown in the surging region E (shown in FIG. 1B), the vane opening in the turbocharger 19 is increased or decreased.

  In the case of NO in step S2 (when the engine speed N is less than the reference speed No), the control computer C sets the electromagnetic switching valve 42 to the first supply state and operates the electric rotary valve 36 (pulsation generation). State) control is performed (step S5). As a result, the electric rotary valve 36 is intermittently opened and closed, and the air sent from the turbocharger 19 is sent to the branch pipe 18, and the air sent to the branch pipe 18 burns through the electric rotary valve 36. It is sent to the chambers 11A, 11B, 11C, 11D.

  When the electric rotary valve 36 is actuated, intake pulsation is generated upstream of the electric rotary valve 36. The intake pulsation repeatedly increases or decreases the supercharging pressure between the compressor unit 20 and the electric rotary valve 36, and when the supercharging pressure P1 is reduced, the ratio P1 / Po is reduced and the air flow rate F is increased. As a result, the supercharging state (P1 / Po, F) enters the non-surging region E. When the supercharging pressure P1 increases due to the generation of the intake pulsation, the ratio P1 / Po increases and the air flow rate F decreases. As a result, the supercharging state (P1 / Po, F) enters the surging region G (shown in FIG. 1B). That is, in the supercharging state (P1 / Po, F), a boundary L (shown in FIG. 1B) between the non-surging region E and the surging region G is generated by the intake pulsation generated by the operation of the electric rotary valve 36. It will be repeated repeatedly. As an example, by moving left and right on the curve Y in FIG. 1B, the supercharging state (P1 / Po, F) repeats the boundary L between the non-surging region E and the surging region G due to the generation of intake pulsation. Straddle. However, by setting the period of the intake pulsation to be shorter than the surging period, no surging occurs even if the supercharging state (P1 / Po, F) enters the surging region G.

In the present embodiment, the opening / closing cycle of the electric rotary valve 36 (the cycle of the generated intake pulsation) is set to a cycle shorter than the surging cycle.
The control computer C performs control for controlling the electric rotary valve 36 to generate a pulsation generation state so that the supercharging state by the turbocharger 19 repeatedly crosses the boundary L between the surging region G and the non-surging region E. It is.

In the first embodiment, the following effects can be obtained.
(1) Since the supercharging state (P1 / Po, F) reciprocates between the surging region G and the non-surging region E in a cycle shorter than the surging cycle, the supercharging state (P1 / Po, F) enters the surging region G. Even if it enters, surging does not occur. Therefore, even when the engine speed is a low speed that conventionally causes surging, it is possible to avoid the occurrence of surging and increase the boost pressure, and the output torque in the engine low speed region is improved. Fuel consumption is improved.

  The inventor of the present application generates an intake air pulsation and reciprocates the surcharge region (P1 / Po, F) between the surging region G and the non-surging region E in a cycle shorter than the surging cycle. The presence or absence of a surging sound when 1250 rpm and the time-average pressure ratio P1 / Po is 1.45 was confirmed by hearing, but it was confirmed that no surging sound was generated when surging occurred.

  (2) When the engine speed N is equal to or higher than the reference speed No (when the internal combustion engine is at a high speed), the supercharging pressure is increased and the intake air temperature is increased, but the intake air at the high speed is It is sent to the intercooler 41. Therefore, the intake air when the internal combustion engine is at a high rotational speed is cooled by the intercooler, and a decrease in air supply efficiency is avoided.

  (3) The period of the intake pulsation generated by the electric rotary valve 36 can be easily set by adjusting the rotational speed of the electric rotary valve 36. Such an electric rotary valve 36 is simple in setting the period of intake pulsation appropriately.

Next, a second embodiment of FIG. 5 will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In the second embodiment, a Roots pump 49 is used as the intake pulsation generating means, and an electromagnetic opening / closing valve 52 is provided in the parallel portion 171 of the intake pipe 17. The electromagnetic on-off valve 52 is subjected to excitation / demagnetization control by the control computer C. When the electromagnetic on-off valve 52 is excited, the air sent from the compressor unit 20 is supplied to the intercooler 41. When the electromagnetic on-off valve 52 is demagnetized, the air sent from the compressor unit 20 is sent to the intercooler 41. Not supplied.

  The roots pump 49 includes an electric motor 50, and the rotors 491 and 492 in the rotor housing 51 of the roots pump 49 are rotated in opposite directions by the operation of the electric motor 50. The suction chamber 501 defined in the rotor housing 51 by the rotors 491 and 492 communicates with the branch pipe 18 upstream from the roots pump 49, and the discharge chamber 502 defined in the rotor housing 51 by the rotors 491 and 492 The branch pipe 18 communicates downstream from the roots pump 49. When the Roots pump 49 is operated, the air sent out from the compressor unit 20 is sent to the combustion chambers 11A, 11B, 11C, and 11D via the branch pipe 18.

  The volume of the suction chamber 501 varies with the rotors 491 and 492, and when the roots pump 49 is operated, intake pulsation is generated in the intake pipe 17 upstream of the roots pump 49. When the roots pump 49 is operated, the electromagnetic on-off valve 52 is demagnetized.

  The period of the intake pulsation generated by the roots pump 49 is set to be shorter than the surging period, and the intake pulsation generated by the roots pump 49 is not surging as in the first embodiment. The supercharging state (P1 / Po, F) is changed so as to repeatedly cross the boundary L between the region E and the surging region G.

  In the second embodiment, the same effect as in the first embodiment can be obtained. The roots pump 49, which is a non-turbo type pump, is in a state where air flow is not possible when the operation is stopped, and the air flow in the branch pipe 18 can be interrupted if the roots pump 49 is set to the operation stop state.

  In addition, the roots pump 49 does not supercharge air and merely opens and closes the passage intermittently as in the electric rotary valve 36 of the first embodiment. It is rotated with a very small force compared to an electric turbocharger or supercharger.

Next, a third embodiment shown in FIGS. 6A and 6B will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
As shown in FIG. 6B, the turbocharger 19A is a twin-entry turbine type having a pair of scroll passages 313 and 314. The end portions of the scroll passages 313 and 314 have interference switching vanes 53, 54 is provided.

  The exhaust gas discharged from the combustion chambers 11A and 11D is sent to the scroll passage 313 via the exhaust pipes 24A and 24D (see FIG. 6A), and the exhaust gas discharged from the combustion chambers 11B and 11C is exhausted. It is sent to the scroll passage 314 via the pipes 24B and 24C (see FIG. 6A). As indicated by the chain line, if the interference switching vanes 53 and 54 are opened, the exhaust pulsation on the scroll passage 313 side and the exhaust pulsation on the scroll passage 314 side can be made to interfere with each other.

  In the engine low engine speed region where the output is small, the interference switching vanes 53 and 54 are closed to increase the turbine driving force and increase the supercharging pressure, and the exhaust pulsation on the scroll passage 313 side and the exhaust pulsation on the scroll passage 314 side To prevent interference.

  In the high engine speed region where the exhaust pulsation is large, the turbine section 21 side may choke and the turbine efficiency may deteriorate. In such a case, the exhaust pulsation on the scroll passage 313 side and the exhaust pulsation on the scroll passage 314 side interfere with each other to attenuate the exhaust pulsation, so that the turbine can be driven using the normal static pressure of the exhaust. it can.

In the present invention, the following embodiments are also possible.
In the first embodiment, when the intercooler 41 is not used, the second passage (parallel portion 171) is eliminated, and the electric rotary valve 36 is operated in the low engine speed range, so that the high engine speed is increased. In the region, the electric rotary valve 36 may be kept open.

A rotary valve or a roots pump that obtains driving force from the engine via an electromagnetic clutch may be used as the intake pulsation generating means.
○ Based on factors other than engine speed, detect or infer the relationship between the supercharging state and the surging area, and if the supercharging state enters the surging area or if it is about to enter the surging area, the intake pulsation generating means is The operation may generate an intake pulsation, and when the supercharged state enters a non-surging region, the generation of the intake pulsation by the intake pulsation generation unit may be stopped.

  In the first embodiment, it is not always necessary to generate the intake pulsation when the engine is running at a low speed. For example, even when the engine is running at a low speed, a control that generates an intake pulsation and operates in a surging region, and a control that operates in a non-surging region by driving a vane of a supercharger so that the supercharging pressure is lowered. May be switched according to a predetermined condition.

  The means for adjusting the opening degree of the vane of the supercharger is a supercharging state adjusting means, and the control computer C is a control means for controlling the adjusting state of the supercharging state adjusting means. That is, the control computer C has a control function of controlling the supercharging state adjusting means so as to adjust the supercharging state by the supercharger to be located in the surging region.

O The supercharging state may be controlled by a wastegate valve or the like in addition to the adjustment by the vane opening.
O If a supercharger having a characteristic that originally enters the surging region without particularly adjusting the supercharging state, a mechanism for adjusting the supercharging state may not be provided.

The electric rotary valve is repeatedly opened and closed. However, the intake pulsation may be generated by repeatedly opening and closing the passage.
O The intake pulsation generating means may be controlled so as to generate an intake pulsation having a cycle earlier than the specified surging cycle by specifying a surging cycle.

  ○ The maximum value of the surging period is obtained by experiment etc. without specifying the surging period, and the intake pulsation generating means is controlled so as to always generate a constant intake pulsation with a period earlier than the maximum value of the surging period. Also good.

The intake pulsation generating means is not particularly controlled, and an intake pulsation generating means that always generates a constant intake pulsation with a period earlier than the maximum value of the surging period may be used.
The present invention may be applied to a vehicle equipped with a fuel cell. In this case, air is sent to the fuel cell by an electric turbo compressor, and the intake pulsation generating means is provided in the gas supply passage downstream of the turbo compressor.

  -You may apply this invention to a gasoline engine.

  10: A diesel engine as an internal combustion engine. 11A, 11B, 11C, 11D ... combustion chambers. 19, 19A ... turbocharger. 17 ... Intake pipe. 171 ... A parallel section as the second passage. 18: A branch pipe as a first passage constituting the gas supply passage. 311, 313, 314... Scroll passage. 36: Electric rotary valve as an open / close switching valve which is an intake pulsation generating means. 41 ... Intercooler. 42 ... Electromagnetic switching valve as supply switching means. 49 ... Roots pump as an open / close switching valve. G: Surging area. E: Non-surging area. L ... Boundary. N: Engine speed. No: Reference rotation speed.

Claims (11)

A supercharger which is provided on the gas supply passage and supplies the gas under pressure;
An intake pulsation generating means that is provided downstream of the supercharger of the gas supply passage and generates an intake pulsation of a cycle earlier than a surging cycle in the gas supply passage downstream of the supercharger;
When the supercharged state of the supercharger may be located in a surging region, and when the supercharged state of the supercharger is at least in the surging region, the intake pulsation generating means generates intake pulsation Supercharge control device.   The turbocharger is a turbocharger provided in an internal combustion engine, and the intake pulsation generating means is provided in a gas supply passage extending from the turbocharger to a combustion chamber of the internal combustion engine. The supercharging control device according to 1. A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
Control means for controlling the intake pulsation generating means,
3. The supercharging according to claim 2, wherein the control unit performs control to generate an intake pulsation by the intake pulsation generation unit when the rotation number detected by the rotation number detection unit is equal to or less than a preset reference rotation number. Control device. Supercharging state specifying means for specifying a supercharging state by the supercharger;
Control means for controlling the intake pulsation generating means,
The control unit switches between control for generating an intake pulsation by the intake pulsation generating unit and control for not generating an intake pulsation based on the supercharging state specified by the supercharging state specifying unit. The supercharging control device according to any one of 2. Supercharging state adjusting means for adjusting a supercharging state by the supercharger;
Control means for controlling the intake pulsation generating means,
5. The control unit according to claim 1, further comprising a control function that controls the supercharging state adjusting unit to adjust the supercharging state of the supercharger so as to be located in a surging region. The supercharging control device according to item.   The gas supply passage is branched in parallel with the first passage and the second passage, the first supply state in which gas can be supplied from the supercharger only to the first passage, and only to the second passage. Supply switching means capable of switching to a second supply state in which intake air can be supplied from the turbocharger is provided, and the intake pulsation generation means is provided in the first passage, and the intake pulsation generation The supercharging control device according to any one of claims 2 and 3, wherein when the intake pulsation is generated by the means, the supply switching means is controlled to be switched to the first supply state.   The supercharging control device according to claim 6, wherein an intercooler is provided in the second passage, and the intercooler cools air flowing through the second passage.   The intake pulsation generating means is an open / close switching valve that can be switched between an open state in which gas can flow and a closed state in which gas cannot flow, and generates intake pulsation by repeatedly switching between the open state and the closed state. The supercharging control device according to any one of claims 1 to 5.   The supercharging control device according to any one of claims 1 to 5, wherein the intake pulsation generating means is a Roots pump.   The supercharging control device according to any one of claims 2 to 7, wherein the supercharger is a twin entry turbine type turbocharger having a pair of scroll passages.   The supercharging control device according to claim 10, further comprising switching means capable of switching communication / blocking between the pair of scroll passages.

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