JPH07189721A - Supercharging device for engine - Google Patents

Abstract

PURPOSE:To improve engine output by supercharging while suppressing knocking effectively. CONSTITUTION:A supercharging device auxiliary-drives a turbosuper-charger 24 by injecting oil discharged from an oil pump 108, into the hydraulic turbine of a turbo rotating shaft, or the like. In this case, the open period of an intake port and that of an exhaust port are partially overlapped, and auxiliary driving is performed in the case of engine load being the fixed value or more in the area of the engine speed being the preset lower limit rotating speed or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharger for an engine equipped with a turbocharger.

[0002]

2. Description of the Related Art Conventionally, as a supercharger for an engine having a turbocharger, for example, one disclosed in Japanese Patent Publication No. 59-51649 is known. In this device, a compressor provided on the intake side and a turbine provided on the exhaust side are connected by a turbo rotary shaft, the turbo rotary shaft is rotatably supported by a slide bearing, and a fluid is provided in the middle of the turbo rotary shaft. A turbine is provided and oil is injected into the fluid turbine at a constant flow rate to assist driving of the turbo rotating shaft. More specifically, it is possible to switch between the auxiliary drive state and the auxiliary drive stop state by operating the control valve, and when the pressure of the compressed air output from the compressor becomes a predetermined value or less, the auxiliary drive stop state is changed. Control to switch to the auxiliary drive state and further accelerate the turbo rotary shaft is performed.

[0003]

In the engine with a supercharger described above, a countermeasure against knocking is an important issue. That is, when the supercharging pressure is increased by the turbocharger, the maximum temperature and the maximum pressure in the cylinder are increased, and knocking is likely to occur especially in a high load state.Therefore, there is a limit to the increase of the supercharging pressure. The increase in engine output will also be suppressed.

In view of such circumstances, it is an object of the present invention to provide a supercharging device capable of improving engine output while avoiding knocking during high load operation.

[0005]

As a means for solving the above problems, the present invention provides a turbocharger having a compressor, a turbine, and a turbo rotary shaft connecting these,
In a supercharging device for an engine, comprising: an auxiliary drive means for auxiliary-driving the turbo rotating shaft by energy other than exhaust energy, an intake port open period and an exhaust port open period opened in a cylinder of the engine are set to be equal to each other. The auxiliary drive control means is provided for overlapping the parts and for performing the auxiliary drive when the engine load is equal to or higher than a predetermined value in a region where the engine speed is equal to or higher than a preset lower limit speed (claim 1). .

In this apparatus, the auxiliary drive may be performed only in a region where the engine speed is equal to or lower than the upper limit speed, which is higher than the lower limit speed (claim 2).

Further, the turbo rotary shaft is divided into a compressor side shaft and a turbine side shaft, and in a region where the engine speed is less than a predetermined speed, the compressor side shaft and the turbine side shaft are relatively rotatably separated from each other. In a region where the number of revolutions is a predetermined number or more, a connection switching means for connecting the compressor side shaft and the turbine side shaft is provided, and the compressor side shaft is auxiliary driven in a region where the compressor side shaft and the turbine side shaft are disconnected. By configuring the auxiliary drive control means as described above, a more excellent effect as described below can be obtained (claim 3).

In each of the above devices, in the region where the auxiliary drive is performed, in the region where the engine speed is equal to or higher than the preset rotational speed, the auxiliary driving force is reduced so as to be lower than the region where the engine speed is lower than the rotational speed. It is more preferable to configure the drive control means (claim 4).

Particularly, in the device according to the third aspect, in the region where the compressor side shaft and the turbine side shaft are connected to each other in the region where the auxiliary drive is performed, the region where the compressor side shaft and the turbine side shaft are separated from each other. It is more preferable to configure the auxiliary drive control means so as to lower the auxiliary drive force (claim 5).

As a concrete means for auxiliary driving, an injection means for injecting a fluid into the turbocharger, and the energy of the fluid injected from the injection means is used as the rotational energy of the rotary shaft of the turbocharger. A fluid turbine for conversion and a variable displacement pump for supplying fluid to the injection means are provided, and a displacement control means for controlling the displacement of the variable displacement oil pump is preferably provided as the auxiliary drive control means. (Claim 6).

[0011]

In the device according to claim 1, since the open period of the intake port and the open period of the exhaust port partially overlap, the supercharged air introduced into the cylinder from the intake port during this overlap period. With the so-called scavenging action of expelling the combustion gas through the exhaust port, it is possible to lower the temperature in the cylinder and avoid knocking. Here, in a general supercharged engine, it is difficult to sufficiently obtain the above-mentioned scavenging action because the supercharging pressure and the exhaust side pressure increase as the engine speed increases. In the device described above, the turbocharger is auxiliary driven by energy other than exhaust energy during high load operation in the region where the engine speed is equal to or higher than the preset lower limit speed, and therefore the boost pressure is exhausted by this auxiliary drive. Above atmospheric pressure, sufficient scavenging action is maintained.

On the other hand, in the medium / high speed / low load operation region where knocking is unlikely to occur, the fuel consumption is reduced by stopping the auxiliary drive. Particularly, in the device according to the second aspect, the fuel consumption is further reduced by stopping the auxiliary drive during high speed operation in which knocking is relatively unlikely to occur even under a heavy load.

According to the third aspect of the present invention, the turbo rotary shaft is divided into a compressor side shaft and a turbine side shaft, and the compressor side shaft and the turbine side shaft are opposed to each other in a region where the engine speed is less than a predetermined speed. Since the compressor side shaft is rotatably separated and the compressor side shaft is auxiliary driven in this separated state, the auxiliary drive force required to raise the boost pressure is less than when the entire turbo rotary shaft is auxiliary driven. Fuel consumption is saved.

In the turbocharger described above, when the engine speed is low, a relatively high auxiliary driving force is required to increase the speed of the turbo rotating shaft to a sufficient speed.
When the exhaust energy rises as the engine speed increases, this exhaust energy can cover most of the drive energy required for engine supercharging. For auxiliary drive, the supercharging pressure can be raised above the exhaust pressure. Only a small driving force is needed. Therefore, as described in claim 4, in the region where the engine speed is equal to or higher than a preset engine speed in the region where the auxiliary drive is performed, the auxiliary driving force is reduced as compared with the region where the engine speed is lower than the engine speed. By configuring the auxiliary drive control means, wasteful consumption of the auxiliary drive force is prevented and fuel consumption is reduced.

In the turbocharger having the divisible turbo rotary shaft as described in claim 3, when the compressor side shaft and the turbine side shaft are connected as the engine speed increases, the exhaust energy Since the driving force required for engine supercharging can be covered by use, the auxiliary drive control means should be configured so that the auxiliary driving force is lower than the region where the compressor side shaft and the turbine side shaft are separated as described in claim 5. As a result, wasteful consumption of the auxiliary driving force is prevented, and fuel consumption is reduced.

[0016] Here, in the apparatus according to the sixth aspect, the auxiliary drive is performed by injecting the pressure fluid supplied from the variable displacement pump to the fluid turbine of the turbo rotary shaft by the injection means, and the variable displacement type The auxiliary driving force is controlled by the change in the capacity of the pump.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

The engine body 10 in this embodiment is provided with a plurality of cylinders 2 arranged side by side as shown in FIG. An intake port 3 and an exhaust port 4 are opened in the combustion chamber of each cylinder 2 and a spark plug 5 is faced, and the intake port 3 and the exhaust port 4 are opened and closed by an intake valve and an exhaust valve (not shown), respectively. It is like this. Both valves are driven to open and close by a valve operating mechanism (not shown), and their open periods are set as shown in FIG. That is, the exhaust valve opens from near the piston bottom dead center to near the piston top dead center,
The intake valve is configured to open from near the piston rising point to near the piston bottom dead center, and between the opening periods of both valves, a predetermined overlap period is secured near the piston top dead center. (The mesh part in Fig. 3).

A common intake pipe 14 is connected to each cylinder 2 through an intake manifold 12 as shown in FIG.
An injector 8 is provided in the intake manifold 12. An air cleaner 18, a compressor of the turbocharger 24 (described later in detail), an intercooler 16, a throttle valve 15 and the like are provided in this order from the upstream side in the middle of the common intake pipe 14. A common exhaust pipe 20 is connected to each of the cylinders 2 via an exhaust manifold 19, and a turbine of the turbocharger 24 (described later in detail), an exhaust gas purifying catalyst 22 and the like are provided in the middle thereof. There is.

The internal structure of the turbocharger 24 is shown in FIG. The turbocharger 24 includes a compressor 26 and a turbine 28, which are connected to each other by a turbo rotating shaft 35, similarly to a normal turbocharger. The compressor 26 is housed in a compressor housing 30, and the turbine 28 is housed in a turbine housing 32. The compressor housing 30 is the common intake pipe 14 described above.
The turbine housing 32 is incorporated in the middle of the common exhaust pipe 20. The two housings 30 and 32 are connected to each other via a substantially cylindrical main body housing 34, and the turbo rotary shaft 35 is rotatably supported by the main body housing 34.

In the turbocharger 24, the turbo rotary shaft 35 is divided into a compressor side shaft 36 and a turbine side shaft 37, and a centrifugal clutch (connection switching means) is provided between them.
60 is provided. The centrifugal clutch 60 disengages the turbine-side shaft 37 and the compressor-side shaft 36 from each other so that the turbine-side shaft 37 and the compressor-side shaft 36 can rotate relative to each other when the rotation speed of the turbine-side shaft 37 is less than a certain value. The centrifugal force connects the turbine-side shaft 37 and the compressor-side shaft 36 so that they rotate together, and a known centrifugal clutch or the like can be applied.

A hydraulic turbine (fluid turbine) 38 is provided at an appropriate position on the compressor side shaft 36. The hydraulic turbine 38 is formed with blades shaped to convert the energy of the working oil flow having a circumferential component from the compressor side (the right side in FIG. 1) to the rotational energy of the turbo rotary shaft 35. . On the other hand, an oil supply nozzle (injection means) 62 penetrating the side wall of the main body housing 34 in the radial direction is fixed, and an injection port 40 of the oil supply nozzle 62 is connected to the hydraulic turbine 38 in the main body housing 34. It is directed.

Reference numeral 42 in FIG. 4 denotes an oil discharge pipe for guiding the oil in the turbocharger 24 to the outside of the machine as appropriate.

As shown in FIG. 1, the engine 10
An oil pump 108 is connected to the crankshaft 102 via a drive transmission mechanism 104. The oil pump 108 is configured to operate by receiving the driving force of the crankshaft 102, and pressure-feed the lubricating oil in the engine 10 to the oil supply nozzle 62 as operating oil.

The structure of this oil pump 108 is shown in FIG. The oil pump 108 is of a variable displacement type, and includes an outer housing 44 and a rotor housing 46 that slides inside the outer housing 44.
On the side wall of the outer housing 44, an oil intake port 44
a and the oil discharge port 44b are formed, and the oil suction port 4
4a is connected to the engine body 10, while the oil discharge port 44b is connected to the oil supply nozzle 62 of the turbocharger 24. In the rotor housing 46,
An oil suction groove 46a and an oil discharge groove 46b are formed. Within the sliding range of the rotor housing 46, the oil suction port 44a and the inside of the rotor housing 46 are communicated with each other via the oil suction groove 46a. The oil discharge port 44b and the inside of the rotor housing 46 are communicated with each other via the discharge groove 46b.

A rotor 50 is supported on the outer housing 44 side so as to be rotatable around a rotor rotation shaft 48,
A plurality of vanes 52 are mounted on the outer peripheral portion of the rotor 50 so as to be movable in the radial direction, and the rotor 50 and the vanes 52 are housed in a rotor housing 46. The shaft 48 is connected to the drive transmission mechanism 104, and the rotor housing 46 slides with respect to the outer housing 44 while the shaft 48 and the rotor 50 are rotationally driven, whereby the oil discharge capacity is increased. Is changing. Specifically, as the amount of eccentricity between the rotor housing 46 and the shaft 48 increases (that is, the rotor housing 46 slides leftward from the position in FIG. 5), the pump capacity also increases.

A rod 44c is extended from the rotor housing 46 in the sliding direction, and the rod 44c is a slide driving device (constituting capacity control means) 80.
Are linked to. The slide driving device 80 includes a stepping motor and a ball screw mechanism, and is configured to slide the rotor housing 46 by operating the stepping motor.

Further, this engine includes a throttle sensor 116 for detecting a throttle opening θ, an engine speed sensor 117 for detecting an engine speed Ne, and an intake pressure B.
An ECU (engine control unit; constituting capacity control means) 120 including various sensors such as a negative pressure sensor 118 for detecting an oost and a microcomputer is provided, and the slide drive device 80 is operated by a control signal output from the ECU 120. Control, that is, pump displacement control is executed.

For example, the slide drive device 80 is operated by the output of the control signal, and the rotor housing 46 is slid to a position where the eccentric amount between the rotor rotary shaft 48 and the rotor housing 46 is minimized as shown in FIG. In this case, the capacity of the oil pump 44 is suppressed to the minimum minute amount, and the auxiliary drive is substantially not performed. On the other hand, the output of the control signal causes the slide drive device to slide the rotor housing 46 from the position shown in the left direction in the figure to increase the eccentric amount between the rotor rotation shaft 48 and the rotor housing 46, whereby the oil pump 44 Capacity is increased and the auxiliary driving force is increased.

Here, the ECU 120 is configured to perform auxiliary drive control as shown in FIG. 6 according to the operating state of the engine. The contents are summarized below.

I) An operating range (hereinafter, referred to as "the engine speed Ne" below a preset lower limit engine speed (rotational speed at which the centrifugal clutch 60 starts connecting the compressor side shaft 36 and the turbine side shaft 37)) It is referred to as a low speed region.): The slide drive device 80 is designed to maximize the capacity of the oil pump 108 regardless of the engine load Pe.
Operate. That is, only the compressor 26 and the compressor side shaft 36 are auxiliary driven by a large auxiliary driving force.

Ii) Operating range in which the engine speed Ne is equal to or higher than the lower limit speed N1 and lower than a preset upper limit speed N2 (> N1) (hereinafter referred to as a medium speed range): the engine load Pe is preset. When the load is less than the applied load P1, the capacity of the oil pump 108 is minimized to substantially stop the auxiliary drive. That is, only turbocharging is performed. On the other hand, when the engine load P1 is a high load equal to or higher than the load P1, the auxiliary drive is performed, but the capacity of the oil pump 108 at this time is made smaller than in the case of i) to suppress the auxiliary drive force. That is, the auxiliary drive of the entire turbo rotary shaft 35 is performed with a small auxiliary drive force.

Iii) Operating range in which the engine speed Ne is equal to or higher than the upper limit speed N2 (hereinafter referred to as high speed range):
Regardless of the engine load Pe, the capacity of the oil pump 108 is minimized to substantially stop the auxiliary drive. That is, only turbocharging is performed.

Next, the operation of this device will be described.

First, when the engine body 10 is started,
Since the engine speed Ne is sufficiently low, the turbocharger 24
The inner centrifugal clutch 60 is in the off state, and the compressor-side shaft 36 and the turbine-side shaft 37 are rotatable independently of each other. On the other hand, in this low speed region, the slide drive device 80 receives the control signal of the ECU 120 and maximizes the capacity of the oil pump 108. Therefore, when the oil pump 108 operates by receiving the driving force of the crankshaft 102 of the engine body 10, the oil in the engine 10 is discharged at a sufficient amount.
2 is supplied to the hydraulic turbine 38 from the nozzle injection port 40.
Is jetted toward. As a result, the compressor side shaft 36 is rotationally driven integrally with the hydraulic turbine 38 by a strong auxiliary driving force, and the boost pressure is rapidly increased.

When the acceleration is proceeded in this way and the engine speed Ne enters the medium speed range of the lower limit speed N1 or more,
The rotational speeds of the turbine 28 and the turbine-side shaft 37 are also sufficiently increased, and the centrifugal force causes the centrifugal clutch 60 to operate, connecting the turbine-side shaft 37 and the compressor-side shaft 36 so that they rotate together. With this connection, the compressor side shaft 36 is driven by the exhaust energy.

Here, conventionally, particularly in a high load state,
Although there is a disadvantage that knocking is likely to occur due to an increase in supercharging pressure, in this embodiment, the exhaust valve opening period and the intake valve opening period overlap as shown in FIG. Moreover, in the high load region where the engine load Pe is equal to or higher than the constant load P1 (the region where knocking is likely to occur), the auxiliary drive is continued similarly to the low speed region, so that the supercharging pressure is sufficiently higher than the exhaust pressure. In the overlap period, it is possible to sufficiently secure the so-called scavenging action that expels the combustion gas in the cylinder to the outside of the cylinder through the exhaust port 4 by the supercharging introduced from the intake port 3, thereby lowering the maximum temperature in the cylinder and knocking. Can be suppressed. That is, the combination of ensuring the overlap of the intake and exhaust periods and the auxiliary drive of the turbocharger 24 effectively suppresses knocking, and the maximum boost pressure is relaxed by that amount, and the output of the engine is improved. Is achieved.

In the medium speed and high load region, the turbo rotary shaft 35 is driven by the exhaust energy as described above,
Since driving with this exhaust energy can almost secure the supercharging pressure required to increase the engine output, unlike the low speed region where supercharging is performed only with auxiliary driving, the necessary auxiliary driving force secures the scavenging action. As much as possible, only a slight force is required to increase the boost pressure relatively to the exhaust pressure. Here, in the device of this embodiment, the ECU 120 is operated in the medium speed and high load region.
Control reduces the capacity of the oil pump 108 more than in the low speed region, and thus reduces fuel consumption.

On the other hand, in the medium-speed low-load region and the high-speed region where knocking is unlikely to occur, the capacity of the oil pump 108 is minimized and the auxiliary drive is substantially stopped,
Fuel economy is further reduced.

The present invention is not limited to such an embodiment, but the following modes can be adopted as an example.

(1) In the above embodiment, the turbo rotary shaft 35 is configured to be dividable, but instead of this, a conventional turbo rotary shaft integrally configured from the compressor 26 to the turbine 28 is used as in the conventional case. A turbocharger with a shaft may be used. In this case as well, in the low speed region, it is necessary to secure the boost pressure mainly for the auxiliary output to improve the engine output, whereas in the medium speed region where the exhaust energy is high, the turbo drive alone is sufficient to improve the engine output. Since the supply pressure can be almost secured and the auxiliary driving force only needs to be added by the amount that increases the supercharging pressure relative to the exhaust pressure, by lowering the auxiliary driving force in the medium speed / high load region than in the low speed region, Fuel efficiency can be reduced while ensuring sufficient engine output.

In this way, in the supercharger in which the turbo rotary shaft is integrated, the auxiliary drive may not be performed in the low speed region unless a particularly high engine output is required.

However, if the turbo rotary shaft 35 is divided into the compressor side shaft 36 and the turbine side shaft 37 in the low speed region as described above and only the compressor side shaft 36 is auxiliary driven, the turbine 28 having a large moment of inertia is obtained. Compared with the case where the entire turbo rotary shaft 35 is auxiliary driven with
There is an advantage that the required driving force can be reduced and the fuel consumption can be further reduced while ensuring good acceleration.

(2) Although the variable displacement oil pump 108 is used in the above embodiment, the auxiliary driving force is not increased or decreased according to the operating region as described above, and the auxiliary driving is not performed. When performing control only to switch to the state, it is not necessary to use the variable displacement oil pump 108. In this case, for example, a clutch may be interposed between the drive transmission mechanism 104 and the oil pump 108, and the on / off state of the clutch may switch the oil pump 108 between an operating state and a stopped state.

(3) In the above embodiment, the engine speed Ne
Although the auxiliary drive is stopped in the high speed region of the upper limit rotation speed N2 or more, the auxiliary drive may be performed also in this high speed region at the time of a high load in which knocking may occur.

(4) In the above embodiment, the centrifugal clutch 60 is used as the connection switching means so that the connection / disconnection can be automatically switched according to the engine speed. Instead of this, a normal hydraulic clutch may be used, and the on / off control of the hydraulic clutch may be performed by operating the actuator in accordance with the engine speed.

[0047]

As described above, according to the present invention, the open period of the intake port and the open period of the exhaust port are partially overlapped with each other, and the engine load is increased in the region where the engine speed is equal to or higher than the preset lower limit speed. When the above is a certain value or more, the turbocharger is auxiliary driven, so by increasing the supercharging pressure relative to the exhaust pressure by the auxiliary driving in the overlap period, A so-called scavenging action for expelling the combustion gas with the supercharged air introduced can be ensured, and thereby engine output can be improved while effectively suppressing knocking. On the other hand, in the medium / high speed / low load operation region where knocking is relatively unlikely to occur, fuel consumption can be reduced by stopping the auxiliary drive.

Particularly, in the device according to the second aspect, there is an effect that fuel consumption can be further reduced by stopping the auxiliary drive during high speed operation in which knocking is relatively unlikely to occur even under high load.

Further, in the apparatus according to the third aspect, the turbo rotary shaft is divided into a compressor side shaft and a turbine side shaft, and the compressor side shaft and the turbine side shaft are provided in a region where the engine speed is less than a predetermined speed. Is relatively rotatably separated, and the compressor side shaft is auxiliary driven in this separated state.Therefore, the auxiliary drive force required to raise the supercharging pressure is kept small compared to when the entire turbo rotary shaft is auxiliary driven. Therefore, there is an effect that fuel efficiency can be reduced while ensuring good acceleration.

Further, in the apparatus according to the fourth aspect of the present invention, in the region where the auxiliary drive is performed, the region where the engine speed is equal to or higher than the preset number of revolutions, that is, the region where a high turbo drive force is obtained by the exhaust energy. Then, since the auxiliary driving force is reduced more than in the low speed region below the rotational speed, there is an effect that wasteful consumption of the auxiliary driving force can be prevented and fuel consumption can be further reduced.

Further, in the turbocharger having the turbo rotary shaft that can be divided as described above, in the device according to claim 5, in the region where the entire turbo rotary shaft is driven by the exhaust energy, the compressor side shaft and the turbine are Since the auxiliary driving force is set to be lower than the area where the side shaft is separated, there is an effect that wasteful consumption of the auxiliary driving force can be prevented and fuel consumption can be saved as in the device according to the fourth aspect.

Here, in the device according to the sixth aspect, there is an effect that the auxiliary driving force can be freely controlled only by changing the displacement of the variable displacement pump.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an engine according to an embodiment of the present invention.

FIG. 2 is a plan view showing a cylinder of the engine.

FIG. 3 is a diagram showing an intake valve open period and an exhaust valve open period set in the engine.

FIG. 4 is a sectional view of a turbocharger mounted on the engine.

FIG. 5 is a cross-sectional view of the variable displacement oil pump and the slide drive device thereof in the above embodiment.

FIG. 6 is a graph showing the contents of auxiliary drive control based on the operating state of the engine.

[Explanation of symbols]

 2 cylinders 3 intake port 4 exhaust port 10 engine body 14 intake passage 20 exhaust passage 24 turbocharger 26 compressor 28 turbine 35 turbo rotary shaft 36 compressor side shaft 37 turbine side shaft 38 hydraulic turbine (fluid turbine) 60 centrifugal clutch (connection) Switching means) 62 Oil supply nozzle (injection means) 80 Slide drive device (constituting capacity control means) 108 Oil pump (variable displacement oil pump) 120 ECU (constituting capacity control means)

Claims (6)

[Claims] 1. A supercharger for an engine, comprising: a turbocharger having a compressor, a turbine, and a turbo rotary shaft connecting them, and an auxiliary drive means for auxiliary driving the turbo rotary shaft by energy other than exhaust energy. In the device, the opening period of the intake port and the opening period of the exhaust port that open in the cylinder of the engine are partially overlapped, and the engine load is constant in a region where the engine speed is equal to or higher than a preset lower limit speed. An engine supercharging device comprising: an auxiliary drive control means for performing the auxiliary drive in the above case. 2. The supercharger for an engine according to claim 1, wherein the auxiliary drive control means is provided so that the auxiliary drive is performed only in a region where an engine speed is higher than the lower limit and equal to or lower than an upper limit. An engine supercharging device characterized by being configured. 3. The turbocharger for an engine according to claim 1, wherein the turbo rotary shaft is divided into a compressor side shaft and a turbine side shaft, and the compressor side is provided in a region where the engine speed is less than a predetermined speed. In the region where the shaft and the turbine side shaft are rotatably separated from each other and the engine speed is equal to or higher than a predetermined speed, a connection switching means that connects the compressor side shaft and the turbine side shaft is provided, and the compressor side shaft and the turbine side shaft are provided. A supercharger for an engine, characterized in that the auxiliary drive control means is configured so as to auxiliary drive the compressor side shaft in a region in which is separated. 4. The engine supercharger according to any one of claims 1 to 3, wherein in the region where the auxiliary drive is performed, the engine speed is equal to or higher than a preset engine speed. A supercharging device for an engine, wherein the auxiliary drive control means is configured so as to reduce the auxiliary drive force more than a region below. 5. The engine supercharger according to claim 3, wherein in the region where the compressor side shaft and the turbine side shaft are connected in the region where the auxiliary drive is performed, the compressor side shaft and the turbine side shaft are connected. A supercharger for an engine, characterized in that the auxiliary drive control means is configured so that the auxiliary drive force is lower than a region where is separated. 6. The engine supercharging device according to claim 4 or 5, wherein, as the auxiliary driving means, an injection means for injecting a fluid into the turbocharger and an energy of the fluid injected from the injection means are provided. The turbocharger includes a fluid turbine that converts the rotational energy of the rotary shaft into rotational energy, and a variable displacement pump that supplies fluid to the injection means, and the auxiliary drive control means has a capacity of the variable capacity oil pump. A supercharging device for an engine, comprising a capacity control means for controlling the engine.