JPH0610682A - Intake air controller of engine with mechanical type supercharger - Google Patents

Abstract

PURPOSE:To prevent any excessive increase in the temperature on the discharge side of a supercharger so as to secure reliability of the supercharger, even at the failure generation time of generation of such a trouble as rejecting operation of a control valve in response to an operational condition. CONSTITUTION:A control valve 15 which operates in response to any variation of a pressure inside an intake passage is provided in a recirculation passage 11 for relief and the control valve 15 is maintained in its condition to be opened to a constant opening by an energizing means serving as a failsafe means formed of one pair of springs 27, 28, at the time of full closed deceleration during malfunction of the control valve 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a relief passage that connects the intake passage downstream side and the supercharger upstream side.
The present invention relates to an intake control device for an engine with a mechanical supercharger, in which a control valve that operates according to operating conditions is provided in the relief passage.

[0002]

2. Description of the Related Art Conventionally, as disclosed in, for example, Japanese Patent Laid-Open No. 3-222819, a mechanical supercharger is provided downstream of a throttle valve in an intake passage, and a downstream side and an upstream side of the supercharger are communicated with each other. A relief passage (bypass passage) is formed, and a control valve (bypass valve) is provided in this passage. When the load is low, the control valve is opened to relieve the supercharger discharge pressure, and when the load is high, the control valve is opened. An intake control device for an engine with a mechanical supercharger is known in which the supercharging pressure is increased by closing the.

The control valve responds to the pressure in the intake passage corresponding to the engine load. According to the structure disclosed in the above publication, the control valve is provided with a valve body and a diaphragm connected to the valve body and is provided downstream of the supercharger. Supercharging pressure acts to balance the valve body and the diaphragm, the valve body is biased in the closing direction by the spring, and the intake negative pressure upstream of the supercharger acts on the valve body downstream of the throttle valve. It is supposed to do. The valve is opened by the negative pressure when the intake negative pressure is large (absolute pressure is small) and is closed by the biasing force of the spring when the intake negative pressure is small (close to atmospheric pressure). .

[0004]

By the way, according to the conventional intake control device as described above, when a failure such as a breakage of the diaphragm or a clogging of a passage for pressure introduction occurs, the pressure is normally applied to the diaphragm or the like. In some cases, the control valve opening actuation force may not be obtained and the control valve opening actuation force may not be sufficiently obtained when the load is low. In this case, the control valve is closed by the biasing force of the spring in the valve closing direction. In this case, the ratio of the pressure on the discharge side of the supercharger to the pressure on the discharge side of the supercharger increases remarkably during deceleration of the fully closed state where the throttle valve is closed and decelerated from the high speed operation state. Since the supercharger discharge side temperature depends on the pressure ratio, there is a problem that the supercharger discharge side temperature rises excessively as the pressure ratio increases, which adversely affects the reliability of the supercharger. there were.

In view of the above circumstances, the present invention prevents the supercharger discharge side temperature from rising excessively even when a failure occurs such that the control valve does not operate normally according to the operating state. An object of the present invention is to provide an intake control device for an engine with a mechanical supercharger, which can ensure the reliability of the supercharger.

[0006]

In order to achieve the above-mentioned object, a first invention (claim 1) is provided with a mechanical supercharger in the intake passage and at the downstream side of the supercharger in the intake passage. A mechanical passage that forms a relief passage that communicates with the upstream side of the turbocharger, and that is provided with a control valve that operates according to the operating conditions so that the relief passage opens in the low load region and closes in the high load region. In an engine with a supercharger, when there is a malfunction in operation according to the operating state of the control valve, and at least when the ratio of the discharge side pressure to the suction side pressure of the supercharger exceeds a predetermined value A fail-safe means for forcibly opening the relief passage is provided.

A second invention (claim 2) is the first invention, wherein the mechanical supercharger is connected to the engine output shaft so as to be constantly driven.

According to a third invention (claim 3), in the first invention, the mechanical supercharger is connected to the engine output shaft via the clutch means so that the mechanical supercharger is operated in an operating region of a predetermined engine speed or more. It is connected.

According to a fourth invention (claim 4), in any one of the first to third inventions, the control valve has a valve body and a pressure responsive portion located in a relief passage. The control valve is configured to operate in response to a change in the intake passage pressure corresponding to the engine load, and the control valve is provided with a predetermined opening degree when the operation fails in response to the change in the intake passage pressure. An urging means for urging the door to open is provided as a fail-safe means.

According to a fifth invention (claim 5), in the fourth invention, a diaphragm is provided in the pressure responsive portion, and the biasing means is constituted by a pair of springs pressing the diaphragm from both sides. There is something.

According to a sixth aspect of the present invention (claim 6), in the first aspect, a passage for bypassing the control valve and a sub valve for opening and closing the passage are provided in the relief passage, and the control valve is provided. The fail-safe means for opening the sub-valve is operated when the operation is defective according to the operating state, and at least when the ratio of the discharge side pressure to the suction side pressure of the supercharger exceeds the predetermined value. It is configured.

According to a seventh invention (claim 7), in the first or sixth invention, the fail-safe means determines the abnormal state by the calculation based on the detection of the suction side pressure and the discharge side pressure of the supercharger. It has a judgment means and a control means for opening the relief passage based on this judgment.

[0013]

According to the present invention, the fail-safe means can increase the ratio of the discharge side pressure to the discharge side pressure of the supercharger even in the case of a failure in which the operation according to the operating state of the control valve is not normally performed. It is possible to obtain the effect of suppressing the rise in the discharge side temperature of the supercharger.

In particular, when the mechanical supercharger is always driven or the mechanical supercharger is operated in an operating range of a predetermined engine speed or more, at the time of the above failure, at the time of fully closing deceleration. The rise of the discharge side temperature of the supercharger, which is likely to occur, is suppressed.

If the control valve is provided with an urging means for urging the valve body to open to a predetermined opening when the control valve malfunctions, the control valve itself has a fail-safe function to ensure the operation. The above effect is obtained.

The above operation can also be obtained by a structure in which a sub-valve for opening and closing a passage bypassing the control valve is provided and the sub-valve is opened when the control valve malfunctions.

[0017]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the overall structure of an intake system for a supercharged engine according to an embodiment of the present invention. In the figure, 1 is an engine body having a plurality of cylinders 2 and 3 is an intake passage for the engine body 1. The intake passage 3 is provided with a supercharger 4 for supplying intake air under pressure. This supercharger 4
Is a mechanical supercharger such as a Risholm type supercharger, and a transmission portion 4a such as a pulley provided at an end of a rotation shaft thereof is connected to an engine output shaft (not shown) via a belt or the like. Is driven by the engine output shaft. Further, the intake valve provided in the intake port of each cylinder 2 of the engine body 1 is set to a late closing so that the closing timing is considerably delayed compared to the normal engine, thereby reducing pumping loss at low load. As well as
When the load is high, the charging efficiency is effectively increased by the effects of intake supercharging, intake cooling and intake valve late closing.

Upstream of the supercharger 4 in the intake passage 3,
A throttle valve 5 whose opening is adjusted by operating the accelerator pedal or the like is provided, and an air cleaner 6 is arranged on the upstream end side of the intake passage 3. In addition, the intake passage 3
An intercooler 7 for cooling the supercharged air is provided downstream of the supercharger 4 in FIG. A surge tank 8 is formed in the intake passage 3 downstream of the intercooler 7, and a branch intake passage 9 downstream of the surge tank 8 is connected to the intake port of each cylinder 2 of the engine body 1.

Further, a relief passage communicating between the downstream side and the upstream side of the supercharger 4 in the intake passage 3 is formed, and the relief passage is provided with a control valve 15 that opens when the engine load is low. . As the relief passage, in this embodiment, a recirculation passage 11 having a control valve 15 is formed, and an auxiliary passage 12 that bypasses the control valve 15 is formed, and a sub valve 30 is formed in the auxiliary passage 12. It is provided. Further, an intercooler bypass passage 13 is provided.

The structure of the intake system will be described in detail with reference to FIG. 1 and FIG. 2 which is an enlarged view of the main parts. The recirculation passage 11 and the intercooler bypass passage 13 are the supercharger of the intake passage 3. 4 and the intercooler 7 branch from each other via a common passage portion 14,
These are arranged so that the outflow side end of the recirculation passage 11 reaches the upstream side of the supercharger 4 of the intake passage 3 while the downstream end of the intercooler bypass passage 13 reaches the downstream portion of the intercooler 7 of the intake passage 3. Passages 11 and 13 are formed. Then, the recirculation passage 11
Is provided with a control valve 15. Also, the common passage part 1
An opening / closing valve 40 is provided at 4.

The control valve 15 operates in response to a change in the pressure in the intake passage corresponding to the engine load, and has a valve body 17 located in a valve chamber 16 provided in the recirculation passage 11. The pressure responsive portion 18 is provided with a diaphragm 20 connected to the valve body 17 via a rod 19.
A first pressure chamber 21 and a second pressure chamber 22 are formed on both sides of. Then, the intake pressure P ₂ downstream of the supercharger acts on the valve body 17 from one side in the valve opening direction, and
From the opposite side, the pressure P ₁ downstream of the throttle valve acts upstream of the supercharger, while the intake pressure P ₂ downstream of the supercharger flows through the first pressure chamber 21 inside the rod 19. It is introduced through 23. In addition, the second pressure chamber 22
Is selectively communicated with the intake passage 3 upstream of the throttle valve 5 and the vacuum tank 26 via the passage 24 and the three-way solenoid valve 25. Normally, the pressure P ₀ upstream of the throttle valve corresponding to atmospheric pressure is Although it is introduced into the second pressure chamber 22, a negative pressure is introduced into the second pressure chamber 22 at the time of forced full closure described later.

Further, when the operation of the control valve 15 is defective according to the operating state, and at least when the ratio of the pressure on the discharge side to the pressure on the discharge side of the supercharger 4 exceeds a predetermined value, an abnormal state occurs. A fail-safe means for opening the relief passage is provided, and in the present embodiment, a pair of springs 27 and 28 for pressing the diaphragm 20 from both sides are provided in the pressure chambers 21 and 22, respectively.
The fail-safe means is constituted by the biasing means composed of 7, 28.

According to the structure of the control valve 15, the pressure P ₂ downstream of the supercharger acts on the valve body 17 from one side and is introduced into the first pressure chamber 21 to act on the diaphragm 20 as well, whereby it is canceled. . Therefore, when in the state in which the pressure P ₀ of the throttle valve upstream to the second pressure chamber 22 is introduced, and the pressure P _0, the pressure P ₁ downstream of the throttle valve which acts on the valve body 17, valve body 17 From the pressure receiving area S of the diaphragm 20, the opening direction displacement amount x of the valve body 17 based on the position where the load of the springs 27 and 28 becomes 0, and the spring constant k of the springs 27 and 28, the following relationship is obtained. The formula holds.

(P ₀ −P ₁ ) S = k · x ... FIG. 3 shows the relationship between the engine load (represented by the intake pressure P ₂ downstream of the supercharger) and the opening of the control valve. As described above, when the load is low (when the intake pressure P ₂ is low), the control valve 15 is fully opened because the pressure difference between the pressure P ₀ upstream of the throttle valve and the pressure P ₁ downstream of the throttle valve is large, and the predetermined load ( When the intake pressure is Pa) or higher, the pressure difference (P ₀ −P ₀ ) increases as the engine load increases (the throttle valve opening increases).
_{As 1} ) becomes smaller, the control valve 15 is gradually closed. Further, when the intake pressure downstream of the supercharger reaches a high load range equal to or higher than a predetermined high pressure Pb higher than the atmospheric pressure, a second signal is output from the control unit (ECU) 40.
The three-way solenoid valve 25 is switched so that a negative pressure is introduced from the vacuum tank 26 into the pressure chamber 22, whereby the control valve 15 is forcibly closed.

Further, the pair of springs 27, 28 constituting the biasing means as the fail-safe means are provided with the valve body 17
Is set in advance so that the pressing force of both springs 27 and 28 cancels each other and the spring load becomes 0 when the valve has a predetermined clearance c (about 0.5 mm) with respect to the valve seat. (See FIG. 4). Therefore, the diaphragm 20
When the operation corresponding to the pressure difference (P ₀ −P ₁ ) is not normally performed due to damage of the control valve 15 or the like, the control valve 15 is kept open for the gap c.

In FIG. 1, the auxiliary passage 12 described above is used.
The sub-valve 30 provided in the main valve is used to relieve the supercharged air mainly when the pressure P ₂ downstream of the supercharger rises excessively, and is located in the auxiliary passage 12 and the pressure P downstream of the supercharger. _A valve body 31 for receiving ₂ , a diaphragm 32 connected thereto via a rod, a pressure chamber 33 formed on one side thereof, and a spring for urging the valve body 31 in a valve closing direction with a relatively large set load. And 34. Negative pressure and atmospheric pressure from the vacuum tank 26 are selectively introduced into the pressure chamber 33 via the three-way solenoid valve 35. Normally, the pressure P ₀ in the intake passage upstream of the throttle valve is maintained in a state of being introduced into the pressure chamber 33, and when the pressure acting on the valve body 31 excessively rises above the pressure set by the spring 34, the sub valve Thirty is open. Further, in addition to such an excessive increase in pressure, when the negative pressure is introduced into the pressure chamber 33 by switching the three-way solenoid valve 35, the sub valve 30 is opened, and the sub valve 30 is forcibly opened as necessary. You can also do it.

The on-off valve 40 provided in the common passage portion 14 is connected to an actuator 41 composed of a diaphragm device, and a negative pressure and an atmospheric pressure from the vacuum tank 26 are connected to the actuator 41 via a three-way solenoid valve 42. And are introduced selectively. And
Three-way solenoid valve 42 according to the operating state by the ECU 45
By the control described above, the on-off valve 40 is opened when the load is low and closed when the load is high.

The ECU 45 receives signals from a throttle opening sensor 46 for detecting the opening of the throttle valve 5, a rotation speed sensor 47 for detecting the engine speed, and the like,
A control signal is output to each of the three-way solenoid valves 25, 35, 42.

The operation of the intake control device of this embodiment as described above will be described below.

When the control valve 15 is normal, it operates according to the pressure difference (P ₀ -P ₁ ) and the opening degree of the control valve 15 changes with the characteristics shown in FIG. This control valve 1
By the operation of No. 5 and the operation of the opening / closing valve 40, the intake air supply state is properly adjusted according to the engine load and the like.

That is, in the low load region, the control valve 1
When 5 is opened, a part of the intake air discharged from the supercharger 4 is returned to the upstream of the supercharger 4 through the recirculation passage 11. As a result, the pressure downstream of the supercharger is relieved, and the pressure downstream of the supercharger (discharge side pressure) P ₂
To the pressure upstream of the turbocharger (pressure on the suction side) P ₁ (P
₂ / P ₁ ) becomes smaller, and the energy loss in the supercharger 4 is reduced. Further, in the low load region, the opening / closing valve 40 is also opened, so that the intake air sent from the supercharger 4 to the engine is divided into the intercooler 7 and the intercooler bypass passage 13 to prevent supercooling (broken line in FIG. 2). Arrow).

Above a predetermined load, the opening of the control valve 15 gradually becomes smaller and the relief is adjusted. Also, when the load reaches a certain level, the opening / closing valve 40 is closed, and when the control valve 15 is open in this state, a part of the intake air that has passed from the supercharger 4 through the intercooler 7 and the intercooler bypass passage 13 and the recirculation. It is returned to the upstream of the supercharger through the aeration passage 11 (solid arrow in FIG. 2).

In the high load region near the fully open throttle valve,
The control valve 15 of the recirculation passage 11 is closed, the opening / closing valve 40 is also closed, and the relief valve 30 is closed as long as the supercharging pressure does not exceed the relief pressure. The discharged intake air is supplied to each cylinder 2 of the engine body 1 through the intercooler 7, and the supercharging performance is enhanced.

On the other hand, when the control valve 15 does not operate normally in accordance with the engine load as described above, the control valve 15 is opened by at least the gap c as shown in FIG. Especially when fully decelerating,
The temperature on the discharge side of the supercharger is prevented from rising excessively.

That is, for example, due to a failure such as the diaphragm 20 being damaged and the first pressure chamber 21 and the second pressure chamber 22 being in communication with each other, the pressure is not substantially applied to the diaphragm 20. If so, the control valve 15 will not operate normally. In this state, the control valve 1
The difference between the supercharger downstream pressure P ₂ acting on the valve body 17 of _{No. 5} and the supercharger upstream pressure P ₁ acts in the opening operation direction, but especially when fully decelerated, for example, P ₁ = 60 mmHg in absolute pressure, P ₂ = 16
Since the difference is about 0 mmHg and the difference (P ₂ −P ₁ ) is small, the valve body 17 is fully closed when a relatively large spring load is applied in the valve closing direction as in the conventional case. Moreover, the pressure ratio (P ₂ / P ₁ ) at this time becomes extremely large. The temperature T ₂ on the discharge side of the supercharger is determined by the pressure ratio (P ₂ /
P ₁ ) and the supercharger suction side temperature (atmosphere temperature) T _1, and T ₂ = (P ₂ / P ₁ ) · T ₁ ..., so the pressure ratio (P ₂ / P ₁ ) Increases, the temperature T ₂ on the discharge side of the supercharger rises excessively.

In such a case, the apparatus of this embodiment is
A pair of springs 27, 2 as fail-safe means
The valve body 17 of the control valve 15 is kept open by the gap c by the urging means consisting of 8, and the pressure downstream of the supercharger is relieved to the upstream side of the supercharger through the gap. Therefore, the increase of the pressure ratio (P ₂ / P ₁ ) is avoided, and the rise of the temperature T ₂ on the discharge side of the supercharger is suppressed.

In the example shown by the solid line in FIG. 1, the rotary shaft of the mechanical supercharger 4 is directly connected to the transmission portion 4a and is always driven by the engine output shaft.
The mechanical supercharger 4 is operated in a high speed range above a predetermined engine speed and stopped in a low speed range by means of a clutch means 4b such as an electromagnetic clutch shown in FIG. 1 and a means for controlling the clutch means 4b. It may be one that has become.

In the above embodiment, the pair of springs 2 is used.
The fail-safe means is constituted by the urging means composed of 7, 28, but as shown in FIG. 5, a spring 50 is provided on one side of the diaphragm 20 to reduce the set load thereof to a fully closed deceleration at the time of failure as described above. The pressure ratio (P ₂ / P ₁ ) becomes large at the time of failure even if it is set to be sufficiently smaller than the force in the valve opening direction due to the difference between the pressures P ₁ and P ₂ that sometimes act on the valve element. The control valve 15 can be opened during deceleration to provide a fail-safe function.

As a further embodiment, as shown in FIG. 6, a three-way solenoid valve 35 provided for the sub-valve 30 of the auxiliary passage 12 is utilized, and the three-way solenoid valve 35 and the ECU 45 for controlling the same are used. Therefore, the fail-safe means may be configured to open the sub-valve 30 when the pressure ratio becomes large at the time of failure. That is, in this embodiment, the ECU 45 includes the pressure sensor 51 for detecting the pressure P ₁ on the upstream side of the supercharger and the pressure P ₁ on the downstream side of the supercharger.
_The pressure ratio (P ₂ / P ₁ ) is calculated based on the signal from the pressure sensor 52 which detects ₂ or these signals and the signal from the temperature sensor 53 which detects the intake air temperature on the upstream side of the supercharger. Based on the above, the supercharger discharge temperature T ₂ is calculated by the above equation. Then, so as to open to actuate the sub-valve 30 by the pressure ratio (P ₂ / P ₁₎ or the supercharger discharge temperature T ₂ controls the three-way solenoid valve 35 when the predetermined value or more.

Thus, when the pressure ratio (P ₂ / P ₁ ) or the discharge temperature T _{2 of the} supercharger is equal to or higher than a predetermined value, the temperature is judged and the control for fail-safe is performed. A solenoid or the like for operating the valve element according to the control signal is provided, and the control valve 1 is controlled by the control signal from the ECU.
5 may be opened.

[0041]

As described above, the present invention provides an engine with a mechanical supercharger having a control valve in a relief passage communicating between the downstream side and the upstream side of the mechanical supercharger. Fail-safe means for forcibly opening the relief passage is provided when the operation is defective, and at least when the ratio of the discharge side pressure to the suction side pressure of the supercharger exceeds a predetermined value. Therefore, even if the control valve fails, the discharge temperature of the supercharger can be prevented from rising excessively, and the reliability of the supercharger can be improved.

Especially when the mechanical supercharger is connected to the engine output shaft so as to be constantly driven (claim 2).
Alternatively, when the mechanical supercharger is connected to the engine output shaft through the clutch means so as to be operated in an operating range of a predetermined engine speed or more (claim 3), all the control valves are operated when the control valve fails. It is possible to prevent an excessive increase in the discharge temperature of the supercharger, which is likely to occur during the closing deceleration.

Further, in the present invention, the control valve configured to operate according to the change in the pressure in the intake passage is biased to open the valve body to a predetermined opening when the control valve malfunctions. If the means is provided (Claim 4) and the biasing means is constituted by, for example, a pair of springs that press the diaphragm from both sides (Claim 5), the control valve itself is provided with a fail-safe function, so that the control valve can be securely operated. It is possible to prevent an excessive rise in the discharge temperature of the feeder.

A passage for bypassing the control valve and a sub-valve for opening and closing the passage are provided, and
Even if the fail-safe means is configured to open the sub-valve in the abnormal state (claim 6), the effect of preventing an excessive rise in the discharge temperature of the supercharger can be obtained as described above.

The fail-safe means has a means for judging the above-mentioned abnormal state by a calculation based on the detection of the suction side pressure and the discharge side pressure of the supercharger, and a control means for opening the relief passage based on this judgment. Even in such a case (claim 7), the above effect can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an entire intake control device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part.

FIG. 3 is a diagram showing an opening characteristic of a control valve.

FIG. 4 is an explanatory diagram showing a state when a control valve is not operating properly.

FIG. 5 is an explanatory view showing a state when the control valve is in a malfunction state in the case of another embodiment.

FIG. 6 is a structural explanatory view of a main part showing still another embodiment.

[Explanation of symbols]

 1 Engine Main Body 3 Intake Passage 4 Supercharger 5 Throttle Valve 11 Recirculation Passage 12 Auxiliary Passage 15 Control Valves 27, 28 Pair of Springs 30 Bypass Means 30 Bypass Valve 45 ECU

Claims (7)

[Claims] 1. A mechanical supercharger is provided in the intake passage, and a relief passage is formed to connect a downstream side of the supercharger of the intake passage and an upstream side of the supercharger, and the engine passage is provided in the relief passage. In a mechanical supercharged engine provided with a control valve that operates according to the operating state so as to open in the load range and close in the high load range, at the time of defective operation according to the operating state of the control valve, and at least When a ratio of the pressure on the discharge side to the pressure on the discharge side of the supercharger exceeds a predetermined value, in an abnormal state, a failsafe means for forcibly opening the relief passage is provided. Intake control device for the engine with a feeder. 2. The intake control device for an engine with a mechanical supercharger according to claim 1, wherein the mechanical supercharger is connected to the engine output shaft so as to be constantly driven. 3. The engine with a mechanical supercharger according to claim 1, wherein the mechanical supercharger is connected to an engine output shaft through a clutch means so that the mechanical supercharger is operated in an operating range of a predetermined engine speed or more. Intake control device. 4. The control valve has a valve body and a pressure responsive portion located in a relief passage, and is configured to operate in response to a change in intake passage pressure corresponding to an engine load. At the same time, the control valve is provided with an urging means as a fail safe means for urging the valve body to open to a predetermined opening when the operation in accordance with the change in the pressure in the intake passage is defective. 4. An intake control device for an engine with a mechanical supercharger according to any one of 3 to 3. 5. The intake control of the engine with a mechanical supercharger according to claim 4, wherein a diaphragm is provided in the pressure responsive portion, and the biasing means is constituted by a pair of springs pressing the diaphragm from both sides. apparatus. 6. The relief passage is provided with a passage that bypasses the control valve and a sub-valve that opens and closes the passage, and at least when the operation is defective according to the operating state of the control valve and at least supercharging is performed. When the ratio of the discharge side pressure to the suction side pressure of the machine exceeds the specified value in an abnormal state,
The intake control device for an engine with a mechanical supercharger according to claim 1, wherein the fail-safe means is configured to open the sub-valve. 7. Fail-safe means includes means for determining the abnormal state by calculation based on detection of suction side pressure and discharge side pressure of the supercharger, and control means for opening the relief passage based on this determination. Claim 1 or 6 which has
An intake control device for an engine with a mechanical supercharger as described.