JP3137801B2 - Engine supercharger - Google Patents

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 having a turbocharger.

[0002]

2. Description of the Related Art In general, an engine equipped with a turbocharger tends to have a lower starting acceleration than an engine without a turbocharger. This is because the engine rotation speed at the time of starting is insufficient, so that the amount of exhaust gas that drives the compressor and turbine of the turbocharger with the torque that can obtain the desired acceleration is not obtained, and the turbocharger by the turbocharger This is because the output torque is rather lowered because the compression ratio of the engine is set lower by the amount.

Therefore, conventionally, for example, Japanese Patent Laid-Open No.
As shown in Japanese Patent Publication No. 29, a hydraulic turbine is mounted on a shaft connecting a compressor wheel and a turbine wheel, and hydraulic oil discharged from the hydraulic pump is directed toward the hydraulic turbine under predetermined conditions such as starting acceleration. A supercharging device has been proposed in which the shaft is integrally driven with the hydraulic turbine by injecting the hydraulic fluid through the through hole to thereby increase the output of the turbocharger.

[0004]

In the above-mentioned engine, it is required to improve responsiveness not only when acceleration is started from a stopped state or a constant speed operation state, but also when re-acceleration is performed from a deceleration state. In this case, if the energy released from the engine during the deceleration is collected and applied to the supercharging power source during the re-acceleration, the acceleration performance during the re-acceleration can be more efficiently improved.

The present invention has been made in view of such a point. By recovering the energy at the time of deceleration of the engine and using the recovered energy, the acceleration at the time of re-acceleration can be efficiently improved. It is intended to provide a supercharging device for an engine.

[0006]

According to the present invention, an auxiliary drive turbine is provided on a connecting shaft for interconnecting a compressor provided in an intake passage and a turbine provided in an exhaust passage in a turbocharger. In a supercharger for an engine configured to auxiliary-drive the connection shaft by supplying a fluid discharged from an engine accessory to a turbine, a relief state in which supercharging by the turbocharger is relieved and a non-relief in which relief is not performed. A supercharged relief device that is switched to a state, and when the engine is decelerated and is in a predetermined operation region, a load generated by driving the engine accessory is increased to accelerate the connection shaft, and the supercharged relief device is brought into a relief state. Switching, the supercharging relief means is switched to a non-relief state during engine acceleration It is obtained by a pressure control means (claim 1).

The predetermined region is preferably a fuel cut region (claim 2).

Further, according to the present invention, in the supercharging device, the connecting shaft is divided into a compressor side shaft and a turbine side shaft which are arranged coaxially with each other, and the compressor side shaft and the turbine side shaft rotate in conjunction with each other. A clutch means that can be switched between a connected state in which the clutch is connected to the engine and a disengaged state in which the clutch is separated so as to rotate relative to each other. The auxiliary drive turbine is provided on the compressor side shaft, and the clutch means is switched in accordance with the operating state of the engine. The above-mentioned supercharging control means is constituted (claim 3).

[0009] The specific contents of the switching control include switching the clutch means to the disengaged state when the engine is decelerating and in a predetermined operating range (claim 4), or switching the engine when the engine is decelerating and operating in a predetermined operation range. The clutch means is switched to the connected state when the engine is in the range, and the clutch means is switched to the disengaged state at the start of engine acceleration (claim 5). Preferably, the clutch means is switched to the disengaged state until the lapse of time, the clutch means is switched to the connected state after a lapse of a predetermined time, and the clutch means is switched to the disengaged state at the start of acceleration (claim 6).

The clutch means includes a fluid pressure clutch which is switched by a fluid discharged from the engine accessory and a clutch switching means which is switched between a state in which the fluid is guided to the fluid pressure clutch and a state in which the fluid is disconnected. It is more preferable to provide (Claim 7).

[0011]

According to the first aspect of the present invention, the engine load for the engine accessory is increased when the engine is decelerated and is in a predetermined operating range (hereinafter, referred to as "predetermined deceleration"). By accelerating the connecting shaft and relieving the supercharging air, the discharge energy at the time of deceleration can be stored as the rotational energy of the turbocharger while avoiding an excessive increase in the supercharging pressure. Then, by stopping the relief at the time of re-acceleration, the boost pressure is rapidly increased by utilizing the stored energy, and acceleration with high responsiveness can be performed. In addition, the effect of the engine brake during deceleration increases as the engine load increases due to the driving of the engine accessory.

[0012] In particular, in the device according to the second aspect, when the operating state of the engine is in a preset fuel cut area as the predetermined operating area, that is, when the running load is extremely low, the driving of the engine accessory is performed. Since the load is increased, the turbocharger can be accelerated without lowering the fuel efficiency of the engine.

According to the third aspect of the invention, when the compressor side shaft and the turbine side shaft are connected by the clutch means, the exhaust gas energy is recovered by the turbine and this energy is used in the same manner as in a normal turbocharger. The compressor can be driven to perform supercharging.On the other hand, if the compressor-side shaft is separated from the turbine-side shaft in the clutch means, and only the compressor-side shaft is driven by the engine accessory, the auxiliary drive turbine, and the auxiliary drive means, , It is possible to obtain a higher compressor rotation speed than when both the compressor and the turbine are driven auxiliary.

As a specific switching control in the device, in the device according to the fourth aspect, the supercharging control is performed such that the clutch means is switched to a disengaged state at the time of the predetermined deceleration (that is, only the compressor is auxiliary-driven). Since the means is configured, compared to the case where the compressor and the turbine are connected at the time of predetermined deceleration and both are auxiliary-driven,
The compressor rotation speed at the time of the predetermined deceleration can be maintained at a higher rotation speed. Therefore, when the acceleration is started during the period in which the auxiliary drive is continued after shifting to the predetermined deceleration, by stopping the relief of the supercharged air,
Full-scale supercharging by the compressor can be started from a higher compressor rotation speed.

Further, since only the compressor is rotationally driven at the time of the predetermined deceleration, the increase in the engine load due to the driving of the engine accessories is small, so that the sudden increase in the engine load due to the driving of the engine accessories can be avoided.

On the other hand, in the apparatus according to the fifth aspect, the clutch means is switched to the connected state at the time of the predetermined deceleration (that is, both the compressor and the turbine are driven), and the clutch means is disengaged at the start of engine acceleration. Since the state is switched, the moment of inertia of the rotating body to be subjected to the auxiliary drive can be further increased as compared with the case where the compressor and the turbine are separated and the compressor is auxiliary-driven at the time of predetermined deceleration.
Therefore, after the shift at the predetermined deceleration, when the operation state goes out of the predetermined region and the auxiliary driving by the engine auxiliary equipment is stopped or the auxiliary driving force is reduced, the rotation of the compressor accompanying the stop or reduction of the auxiliary driving is reduced. A decrease in the number can be suppressed. Therefore, at the start of the subsequent acceleration, the compressor is separated from the turbine, and the compressor alone is auxiliary-driven by the power of the engine auxiliary equipment, thereby quickly increasing the compressor rotation speed from a higher rotation speed to a desired rotation speed. Can be.

Further, in the apparatus according to the sixth aspect, the clutch means is switched to the disengaged state until a predetermined time elapses after the engine decelerates and enters a predetermined operation range, and after the predetermined time elapses, the clutch is disengaged. Since the means is switched to the connected state and the clutch means is switched to the disengaged state at the start of acceleration, the auxiliary drive is continued before the predetermined time has elapsed since the transition to the predetermined deceleration and before the predetermined time has elapsed. When acceleration is started at an early point, the turbocharger relief is stopped from a state in which the compressor rotation speed is maintained at a high level by the auxiliary drive of only the compressor. The supply pressure can be increased more quickly.

On the other hand, after the predetermined time has passed since the shift to the predetermined deceleration, the operating state is out of the predetermined region after connecting the compressor and the turbine, and the auxiliary driving by the engine auxiliary equipment is stopped or the auxiliary driving is stopped. When the force is reduced, a decrease in the rotational speed of the compressor can be suppressed by an increase in the moment of inertia due to the connection between the compressor and the turbine.In this case, when acceleration is started thereafter, By separating the compressor and the turbine from each other and auxiliary-driving only the compressor with the power of an engine accessory, the rotation speed of the compressor is increased from a higher rotation speed to a desired rotation speed in a short time as in the device according to claim 5. Can be pulled up.

Further, as the clutch means in each of the above-mentioned devices, a fluid pressure clutch switched by a fluid discharged from the engine auxiliary machine, and a state in which the fluid is guided to the fluid pressure clutch and shut off. According to the apparatus provided with clutch switching means for switching between the compressor side shaft and the turbine side shaft, the auxiliary drive fluid is used and the clutch switching means alone is used for switching. It can be carried out.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

A common intake pipe 14 is connected to each cylinder of the engine 10 shown in FIG. In the middle of the common intake pipe 14, a throttle valve 15, an intercooler 16, and a turbocharger (actually, a turbocharger also having a function as a supercharger that receives auxiliary driving as described later) 2
4. An air cleaner 18 and the like are provided. In the common intake pipe 14, the upstream portion and the downstream portion of the turbocharger 24 are separated from each other by the turbocharger 24.
Are connected by a bypass passage 17 which bypasses the intake passage.
1 is provided. The intake bypass valve 21 is configured by an electromagnetic switching valve or the like, and is configured to be switched between a state in which the bypass passage 17 is opened and a state in which the bypass passage 17 is shut off in response to an external signal.

A common exhaust pipe 20 is connected to each of the cylinders via an exhaust manifold 19. The turbocharger 24, the exhaust gas purifying catalyst 22, and the like are provided in the middle of the common exhaust pipe 20. It is connected via a gate 23.

The internal structure of the turbocharger 24 is shown in FIGS. The turbocharger 24 includes a compressor 26 and a turbine 28 as in 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 installed in the middle of the common intake pipe 14,
The turbine housing 32 is incorporated in the middle of the common exhaust pipe 20, and the two housings 30, 32 are connected via a substantially cylindrical main body housing.

The compressor 26 is made of a relatively lightweight material such as aluminum and has a relatively small thickness, whereas the turbine 28 is made of a relatively heavy material such as an iron-based material to withstand the high heat of the exhaust gas. It is formed thick. Therefore, the moment of inertia of the turbine 28 is much larger than the moment of inertia of the compressor 26.

A compressor side shaft 36 and a turbine side shaft 38 are housed coaxially in the center of the main body housing 34. And the compressor side shaft 36
Outside end (right end in FIG. 1) of the compressor 2
6, and the outer end (left end in FIG. 1) of the turbine shaft 38 is fixed to the center of the turbine 28.

An inner end (left end in FIG. 1) of the compressor side shaft 36 has a cylindrical portion 37 opening toward the front end.
An inner end (right end in FIG. 1) of the turbine shaft 38 is a small-diameter fitting portion 39 which is fitted into the cylindrical portion 37 so as to be relatively rotatable.

An outer cylinder 41 is externally fitted to the compressor shaft 36 in the radial direction outside in a state of rotating integrally therewith.
In the outer cylinder 41, a portion from the turbine side (FIG. 1)
A hydraulic turbine (auxiliary driving turbine) 43 is integrally formed in a portion from the left side (a portion substantially at the center in the left-right direction in the main body housing 34). In this embodiment, the hydraulic turbine 43 is formed in the shape of a Pelton wheel, and a hydraulic oil is sprayed from a predetermined direction on an outer peripheral portion thereof so that the hydraulic turbine 43 is driven to rotate integrally with the outer cylinder 41 and the compressor shaft 36. It is configured.

A cylindrical bearing housing 40 extending substantially over the entire area in the axial direction is fitted inside the main body housing 34. And, in this bearing housing 40,
Both the outer cylinder 41 outside the compressor-side shaft 36 and the turbine-side shaft 38 are rotatably supported via bearings 42. An oil passage forming ring 45 is provided beside each bearing 42.

A hydraulic clutch 44 as shown in FIG. 2 is provided between the compressor side shaft 36 and the turbine side shaft 38. The hydraulic clutch 44 includes an oil passage forming block 46, a sleeve 48, an outer clutch member 50, an inner clutch unit 52, a spring 58, and the like.

The oil passage forming block 46 is formed with an oil passage for a hydraulic clutch hydraulic oil, which will be described later, and has a cylindrical shape as a whole. The portion of the oil passage forming block 46 from the turbine is a large-diameter portion 46a almost in sliding contact with the inner peripheral surface of the bearing housing 40, and the portion from the compressor is a small-diameter portion 46b smaller in diameter than the large-diameter portion 46a. In addition, the entire oil passage forming block 46 is externally fitted and fixed to the turbine shaft 38. In addition, this oil passage forming block 46
A ring 55 is fixed to the boundary between the large diameter portion 46a and the small diameter portion 46b.

The outer clutch member 50 is connected to the turbine shaft 3
8 has a cylindrical portion having an inner diameter larger than the outer diameter of the oil passage forming block 8, and is fixed to an intermediate portion of the turbine shaft 38 in a state of being sandwiched between the nut 51 and the oil passage forming block 46. The cylindrical portion is open toward the compressor-side shaft 36, and a peripheral inner peripheral surface of the open end has a tapered inner peripheral surface whose diameter decreases toward the back of the cylindrical portion (left side in FIG. 2). 53
It has been.

On the other hand, the inner clutch portion 52 is formed integrally with the end of the cylindrical portion 37 of the compressor shaft 36, and has a cylindrical shape. The outer peripheral surface of the inner clutch portion 52 is a tapered outer peripheral surface 54 that can be pressed against the tapered inner peripheral surface 53 of the outer clutch member 50 from inside.

The sleeve 48 is provided with the outer clutch member 5.
0 is slidably contacted from the outside with the inner clutch portion 52 at the compressor side end (the right end in FIG. 2).
Is fixed from the compressor side. Further, a flange 49 is formed from an appropriate position of the sleeve 48 toward the oil passage forming block 46 on the inner side, and a hydraulic chamber 59 is formed between the flange 49 and the ring 55. I have.

The collar 49 and the outer clutch member 5
A spring (press-contact means) 58 is press-fitted between the positions 0 and 0. The spring 58 urges the sleeve 48 and the ring 56 toward the turbine with its elastic force.
By this resilient force, the compressor side shaft 36 is pressed toward the turbine side while being held by the ring 56 from the compressor side, and this pressing normally causes the outer tapered surface 54 of the inner clutch portion 52 to move toward the outer clutch member. The inner side 50 is pressed against the inner tapered surface 53 from the inside, and the pressed side of the tapered surfaces 53 and 54 allows the compressor side shaft 36 and the turbine side shaft 38 to be coaxially and non-rotatably connected.

Next, the oil passage of the working oil formed in the turbocharger 24 will be described. In this embodiment, a lubricating oil bearing for the bearing 42 is used in common for the hydraulic oil.

A hydraulic oil supply port 62 is formed at an appropriate position on the side wall of the main body housing 34.
Numeral 2 communicates with the bearing housing 40 via a hydraulic oil supply path 64. On the side wall of the bearing housing 40, a groove 65 communicating with the hydraulic oil supply path 64 is formed all around. A plurality of hydraulic oil injection ports 63 communicating with the groove 65 and the inside of the bearing housing 40 are formed. The position of each hydraulic oil injection port 63 is such that hydraulic oil injected from the injection port 63 is sprayed on the outer peripheral portion of the hydraulic turbine 43,
Thus, the hydraulic turbine 43 is formed at a position where the hydraulic turbine 43 is driven to rotate.

On the side wall of the main housing 34, a hydraulic oil supply port 66 is provided at a position different from the hydraulic oil supply port 62. The hydraulic oil supply port 66 is opened at a position different from the groove 65 in the bearing housing 40. ing. A groove 69 is formed over the entire periphery of the bearing housing 40 at a portion facing the opening.
A plurality of hydraulic oil supply ports 67 are formed to communicate the groove 69 with the outer peripheral surface of the large diameter portion 46a of the oil passage forming block 46 in the bearing housing 40.

At the center of the turbine side shaft 38, a working oil passage 70 is formed along the center axis. In the large-diameter portion 46a of the turbine shaft 38 and the oil passage forming block 46, there are formed oil passages 71 and 68 that radially connect the oil supply port 67 and the oil passage 70 in the radial direction. Further, a hydraulic oil that radially communicates the hydraulic oil passage 70 and the hydraulic chamber 59 to a portion of the turbine shaft 38 closer to the compressor than the hydraulic oil passage 71 and to a small diameter portion 46b of the oil passage forming block 46. Paths 73 and 72 are formed.

When the operating oil is supplied from the operating oil passages 73 and 72 into the hydraulic chamber 59, the sleeve 48 and the ring 56 are spring-loaded by the oil pressure.
(See the two-dot chain line in FIG. 2) against the resilience of the compressor, whereby the pressure contact between the tapered surfaces 53 and 54 is released, and the compressor shaft 36 and the turbine shaft 38 can rotate relative to each other. Is to be cut off.

Hydraulic oil recovery passages 81 and 82 communicating with the inside of the bearing housing 40 are formed in the main body housing 34, and these merge into a hydraulic oil discharge port 84.

In the main body housing 34, at a position different from the hydraulic oil supply port 62, a lubricating oil supply port 8 is provided.
6 are formed. The lubricating oil supply port 86 is connected to lubricating oil supply passages 88 and 9 formed in the main body housing 34.
4 communicates with the outer peripheral surface of the bearing housing 40.

On the outer peripheral surface of the bearing housing 40, grooves 89 and 96 are formed all around the position connecting to the lubricating oil supply passages 88 and 94, and the bearing housing 40 and the oil passage forming ring 45 are formed. Are formed with lubricating oil passages 90 and 98 communicating with the grooves 89 and 96, respectively. Each lubricating oil passage 90, 9
8 are formed, and the lubricating oil injected from the oil jets 92, 99 is oriented in the direction of each of the oil jets 92, 99.
2 is provided to be supplied to the sliding portion.

The main body housing 34 has a lubricating oil recovery passage 80 communicating with the openings at both ends of the bearing housing 40.
83 are formed, and these merge with the hydraulic oil discharge port 84.

In FIG. 2, reference numeral 78 denotes a stopper for securing a passage, and reference numeral 100 denotes a water jacket formed in the main housing 34.

As shown in FIG. 3, a hydraulic pump 10 serving as an engine accessory is attached to a crankshaft 102 of the engine 10 via a drive transmission mechanism 104 and a pump clutch 106.
8 are connected. The hydraulic pump 108 has a pressure regulating valve 110
Are connected to both of the hydraulic oil supply ports 62 and 66 via the.

The pump clutch 106 is switched between an on state in which the drive transmission mechanism 104 and the hydraulic pump 108 are connected and an off state in which the drive transmission mechanism 104 and the hydraulic pump 108 are disconnected. In the on state, the driving force of the crankshaft 102 is transmitted to the drive transmission mechanism 104.
The hydraulic pump 108 is configured to operate by transmitting the hydraulic pressure to the hydraulic pump 108 via the
The operation of the hydraulic pump 108 causes the engine 1
The lubricating oil in 0 is supplied as hydraulic oil to the hydraulic oil supply ports 62 and 66 through the pressure regulating valve 110 under pressure.

Further, as shown in FIG.
An electromagnetic clutch valve (clutch switching means) 111 is provided between the secondary side of the valve 10 and the hydraulic oil supply port 66. The clutch valve 111 is switched between a state in which the pressure regulating valve 110 communicates with the hydraulic oil supply port 66 and a state in which the pressure control valve 110 and the hydraulic oil supply port 66 are disconnected by an external signal input.

As shown in FIG. 3, the engine includes a compressor speed sensor 112 for detecting the speed Nc of the compressor 26 per unit time, and the turbine 2
8, a turbine speed sensor 114 for detecting a speed Nt per unit time, and a throttle opening θ of the throttle valve 15.
Sensor 116 for detecting the engine speed N
The engine includes an engine speed sensor 117 for detecting e, an engine intake pipe boost sensor 118 for detecting an intake pipe pressure, and the like. These sensors are connected to an ECU (control unit; drive control means) 120. The ECU 120 controls the fuel injection in the engine 10 and the pump clutch 106 based on the detection signal of each sensor.
ON / OFF control, intake bypass valve 21 and clutch valve 1
11 is configured to perform opening / closing control and the like.

Next, the control operation performed by the ECU 120 and the operation of the entire apparatus will be described with reference to the flowchart of FIG.

First, the ECU 120 calculates the throttle opening θ
Is monitored, and it is determined whether the acceleration / deceleration operation is currently performed.

If the deceleration operation is being performed (NO in step S1 and YES in step S2), the current engine speed Ne and engine load Pe are further determined.
It is determined whether or not is in a preset fuel cut region (a region where fuel injection is not performed; for example, a region where the engine speed Ne is equal to or more than a certain value and the engine load Pe is equal to or less than a certain value) (step S3).

If it is in the fuel cut region (YES in step S3), fuel injection by a fuel injection valve (not shown) is stopped in order to save fuel and prevent emission deterioration. At this time, the pump clutch 106 is turned on, and the intake bypass valve 21 is opened (step S4).
When the pump clutch 106 is turned on, the hydraulic pump 108
Is operated, the lubricating oil in the engine 10 is regulated to a constant pressure by the pressure regulating valve 110, and then supplied to the hydraulic oil supply port 66 of the turbocharger 24. This hydraulic oil is supplied to the groove 65
Through the hydraulic oil injection port 63, the oil is injected into the hydraulic turbine 43 of the outer cylinder 41, whereby the compressor shaft 36 and the compressor 26 are auxiliary-rotated and integrated with the outer cylinder 41 to be accelerated. On the other hand, when the intake bypass valve 21 is opened, a part of the intake air bypasses the compressor 26 and is directly introduced into the cylinder of the engine 10 (that is, supercharged).
, The excessive increase of the supercharging pressure can be avoided.

Here, until the preset time elapses after entering the fuel cut area (N in step S5).
O), the ECU 120 opens the clutch valve 111 (step S6). Therefore, the hydraulic oil from the pressure regulating valve 110 is supplied to the groove 69, the hydraulic oil supply port 67, the hydraulic oil passages 68, 71,
70, 73, and 72 are sequentially introduced into the hydraulic chamber 59, and push the sleeve 48 back to the compressor side (the right side in FIG. 2) against the elastic force of the spring 58. As a result, the force of the spring 58 pushing the inner clutch portion 52 into the inside of the outer clutch member 50 via the ring 56 by the spring force is released, and accordingly, the outer tapered surface of the inner clutch portion 52 is released. 53 and outer clutch member 5
The pressure contact with the 0 inner tapered surface 54 is also released. Therefore, the compressor-side shaft 36 and the turbine-side shaft 38 that have been connected to each other by the frictional force caused by the pressure contact force are separated from each other so as to be rotatable relative to each other.

That is, by the supply of the hydraulic oil, the compressor-side shaft 36 and the turbine-side shaft 38 are separated from each other almost simultaneously with the rotational drive of the hydraulic turbine 43. As a result, only the compressor 26 and the compressor shaft 36 having a small moment of inertia are auxiliary-rotated, so that the energy released during the deceleration is stored as the rotational energy of the compressor 26, and the compressor 26 is driven by the turbine 28 having a large moment of inertia. Turbine side shaft 3
8, the rotation speed of the compressor 26 is further increased.

After such an operation state in the fuel cut region has continued for a predetermined time (YES in step S5), the EC
U120 closes the clutch valve 111 (step S
7). As a result, the supply of hydraulic oil into the hydraulic chamber 59 is stopped, and the tapered outer peripheral surface 54 of the inner clutch portion 52 is moved by the resilience of the spring 58 to the outer clutch member 50.
The compressor-side shaft 36 and the turbine-side shaft 38 are coaxially connected to each other in a non-rotatable manner by the frictional force caused by the press-contact. Therefore, the compressor 26 rotates integrally with the turbine 28, and the moment of inertia of the entire rotating body greatly increases as compared with the case where the compressor 26 rotates alone.

As described above, when the acceleration operation is performed in a state where the compressor 26 is auxiliary-driven while the compressor-side shaft 36 and the turbine-side shaft 38 are connected or disconnected in the fuel cut region (YE in step S1).
S), the ECU 120 closes the clutch valve 111 and the intake bypass valve 21 while keeping the pump clutch 106 on (step S8). Thereby, the compressor side shaft 3
In a state where the turbine 6 and the turbine side shaft 38 are connected, the supercharging relief through the bypass passage 17 is stopped. At this point, the compressor 26, which has been receiving the auxiliary rotation drive and has maintained a high rotation speed, quickly increases the supercharging pressure and realizes acceleration with high responsiveness.

Before the acceleration operation is obtained, if the operating state of the engine is out of the fuel cut region (NO in step S2 or NO in step S3), ECU 120 causes pump clutch 106 to operate. The air conditioner is switched off and the intake bypass valve 21 is closed (step S9). By turning off the pump clutch 106,
The operation of the hydraulic pump 108 stops, and the hydraulic oil supply port 6
Since the supply of the hydraulic oil to the compressor shafts 2 and 66 is stopped, the auxiliary driving of the compressor shaft 36 is stopped, and the compressor shaft 36 and the turbine shaft 38 are connected by the resilience of the spring 58. . Thereafter, when the acceleration operation is performed (YES in step S1), the pump clutch 106 is switched on again in the same manner as described above (step S8), and the compressor 26 is driven again together with the turbine 28.

According to such an apparatus, the following effects can be obtained.

(A) In the fuel cut region at the time of engine deceleration, the hydraulic pump 108, which is an engine accessory, is operated to assist the compressor-side shaft 36 of the turbocharger 24, and the intake bypass valve 21 is opened to overheat. Since the supply air is relieved (step S4), the energy released at the time of engine deceleration can be stored as rotational energy in the turbocharger 24 while avoiding an excessive increase in the supercharging pressure. Therefore, by closing the intake bypass valve 21 at the time of re-acceleration and stopping the relief (step S8), the supercharging pressure is increased by utilizing the stored energy (by the rotation of the compressor 26 which is preliminarily assisted at the time of deceleration). It is possible to increase the speed quickly and perform the acceleration with high responsiveness efficiently. Further, since the engine load is increased by the operation of the hydraulic pump 108, the effect of the engine brake at the time of deceleration is increased accordingly.

(B) Since the hydraulic pump 108, which is an engine auxiliary, is operated in the fuel cut region where the running load is extremely low (YES in step S3), the turbocharger 24 can be operated without lowering the fuel efficiency of the engine. Can be accelerated.

(C) Until a predetermined time elapses after entering the fuel cut region (NO in step S5), the clutch valve 111 is opened and the compressor side shaft 36 and the turbine side shaft 3 are opened.
8 are separated so as to be relatively rotatable (step S6), and since only the compressor 26 is driven alone,
As compared with a case where the compressor 26 and the turbine 28 having a large moment of inertia are integrally driven by connecting the compressors 6 and 38, the compressor rotation speed can be maintained at a higher rotation speed with the same driving load. Therefore, if acceleration is started within a relatively short time after entering the fuel cut area (that is, before entering the fuel cut area and leaving the same area and stopping auxiliary driving), the compressor is started. Full-scale supercharging can be started from a state in which the rotation speed of the compressor 26 is higher than in the case where the turbine 26 and the turbine 28 are connected, and the supercharging responsiveness can be improved accordingly.

On the other hand, after a lapse of a predetermined time after entering the fuel cut region (YES in step S5), the clutch valve 11
1 is closed and both shafts 36 and 38 are connected (step S7),
Since the compressor 26 and the turbine 28 are integrally driven by the auxiliary rotation, the inertia moment of the whole rotating body to be subjected to the auxiliary drive is more increased than the case where the compressor 26 is driven alone by the auxiliary rotation as described above. Can be bigger. Therefore, when a relatively long time has elapsed since the fuel cut-off area was entered, and during that time the operating state of the engine deviated from the fuel cut-off area and the auxiliary drive by the engine auxiliary equipment was stopped, It is possible to suppress a decrease in the compressor rotation speed. Therefore,
At the start of the subsequent acceleration (YES in step S1), the compressor rotation speed can be maintained higher. At the start of the acceleration, the compressor 26 and the turbine 28 are separated and only the compressor 26 is auxiliary-driven (step S8). Further, the compressor rotation speed can be increased to the predetermined rotation speed in a shorter time.

(D) The hydraulic pump 108 is connected to both of the hydraulic oil supply ports 62 and 66 so that the hydraulic oil supply port 62
Since the clutch valve 111 is provided between the hydraulic pump 108 and the hydraulic pump 108, both the auxiliary drive and the clutch operation can be performed using the common hydraulic oil. Moreover, the connection / disconnection of the compressor shaft 36 and the turbine shaft 38 can be switched only by opening and closing the clutch valve 111.

Note that the present invention is not limited to such an embodiment, and the following embodiments can be adopted as examples.

(1) Hydraulic pump 1 during engine deceleration
The region where 08 is operated is not necessarily limited to the fuel cut region, and other regions may be appropriately set. However, setting the fuel cut region as described above has an advantage that the hydraulic pump 108 can be driven without lowering the fuel efficiency of the engine.

(2) In a predetermined area such as the fuel cut-off area, the clutch valve 111 is opened all the time and the compressor side shaft 3
6 and the turbine-side shaft 38 may be separated, or the clutch valve 111 may be closed all the time to connect the compressor-side shaft 36 and the turbine-side shaft 38. In the former case, when acceleration is started within a relatively short time from entering the fuel cut region to leaving the fuel cut region, in the latter case, the acceleration is relatively made after entering the fuel cut region. When the acceleration is started after a long time has elapsed and the auxiliary drive has been stopped outside the fuel cut region, there is an advantage that the compressor speed at the start of the acceleration can be further increased.

(3) In the above embodiment, the state is not during acceleration and is not in the fuel cut region (for example, a normal constant speed operation state;
(NO in steps S2 and S3) that stops the auxiliary drive of the hydraulic pump 108 at all is shown.
The auxiliary driving force by the hydraulic pump 108 may be reduced to a certain value or less.

[0068]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, at the time of predetermined deceleration, the load due to the driving of the engine accessory is increased to accelerate the connecting shaft of the turbocharger and relieve the supercharged air,
Since the relief is stopped at the time of re-acceleration, the discharge energy of the engine at the time of deceleration is stored as the rotational energy of the turbocharger while the boost pressure is not excessively increased at the time of the above-mentioned predetermined deceleration, and the subsequent acceleration is performed. At times, there is an effect that the acceleration response can be efficiently increased by using the stored energy. Also,
By increasing the load due to the driving of the engine accessory, the effectiveness of the engine brake can be further enhanced.

In particular, in the apparatus according to the second aspect, when the operating state of the engine is in a predetermined fuel cut-off area, that is, when the engine load for traveling is extremely low, the engine supplement is set as the predetermined operating area. Since the load for driving the machine is increased, there is an effect that the turbocharger can be accelerated without lowering the fuel efficiency of the engine.

Further, according to the device of the third aspect, by switching the connection / disconnection of the compressor side shaft and the turbine side shaft by the clutch means, only the compressor is auxiliary-driven in accordance with the operation state of the engine. State and
A state in which the turbine is connected to the compressor and the compressor is driven by exhaust energy can be freely switched.

As the specific switching control, in the device according to the fourth aspect, the compressor is separated from the turbine at the time of the predetermined deceleration and only the compressor is auxiliary-driven, so that the compressor and the turbine are connected at the predetermined speed reduction. The compressor rotation speed at the time of this predetermined deceleration can be maintained at a higher rotation speed as compared with the case where both are driven by auxiliary driving. Therefore, when the acceleration is started while the auxiliary drive is continued after the shift at the time of the predetermined deceleration, and the supercharging relief is accordingly stopped, the full-scale supercharging by the compressor is increased by the higher compressor. It can be started with the number of rotations, which has the effect of further improving the acceleration response.

Further, since only the compressor is rotationally driven at the time of the predetermined deceleration, the increase in the engine load due to the driving of the engine accessories is small, so that the sudden increase in the engine load due to the driving can be avoided.

On the other hand, in the apparatus according to the fifth aspect, the compressor and the turbine are connected at the time of the predetermined deceleration to increase the moment of inertia of the auxiliary drive target, and the two are separated at the start of acceleration of the engine so that the compressor has a small moment of inertia. Since only the auxiliary driving is performed, a relatively long time elapses after the shift to the predetermined deceleration, and the driving state is out of the predetermined region, that is, the auxiliary driving by the engine auxiliary equipment is stopped or the auxiliary driving is stopped. It is possible to suppress a decrease in the rotation speed of the compressor when the driving force is reduced. Accordingly, when only the compressor is auxiliary-driven at the start of the subsequent acceleration, full-scale supercharging can be started at a higher compressor rotation speed, and the acceleration responsiveness can be further improved.

Further, in the apparatus according to the sixth aspect, the clutch means is switched to the disengaged state until a predetermined time elapses from the time when the engine enters a predetermined deceleration period which is within a predetermined operation range when the engine is decelerating. After the lapse of time, the clutch means is switched to the connected state, and at the start of acceleration, the clutch means is switched to the disengaged state. When the acceleration is started at a relatively early point in time, the acceleration responsiveness can be increased by the auxiliary drive of the compressor only, as in the device according to the fourth aspect, while the transition to the predetermined deceleration is made. After the above-mentioned predetermined time has elapsed, the driving state goes out of the above-mentioned predetermined region, and the acceleration after the auxiliary driving by the engine accessory is stopped or the auxiliary driving force is reduced. When it is started, there is an effect that can increase the acceleration response in the same manner as apparatus of the claim 5.

Further, in the device according to the seventh aspect, the clutch means includes a fluid pressure clutch switched by a fluid discharged from the engine auxiliary machine, and a state in which the fluid is guided to the fluid pressure clutch and a state in which the fluid is disconnected. Since it is provided with a clutch switching means that can be switched, it is possible to connect and connect the compressor side shaft and the turbine side shaft with a low-cost structure using the auxiliary driving fluid and with a simple operation of switching the clutch switching means. Separation can be performed.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a turbocharger according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is an overall configuration diagram of an engine including the turbocharger.

FIG. 4 is a diagram showing a connection state between a pressure regulating valve and both hydraulic oil supply ports in the engine.

FIG. 5 is a flowchart showing a control operation of an ECU provided in the engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Engine 14 Common intake pipe 17 Bypass passage (constituting supercharging relief means) 20 Common exhaust pipe 21 Intake bypass valve (constituting supercharging relief means) 24 Turbocharger 26 Compressor 28 Turbine 36 Compressor shaft 38 Turbine shaft 43 Hydraulic pressure Turbine (turbine for auxiliary drive) 44 Hydraulic clutch (fluid pressure clutch) 62, 66 Hydraulic oil supply port 102 Crankshaft (engine output shaft) 106 Pump clutch (pump clutch means) 108 Hydraulic pump (engine auxiliary equipment) 111 Clutch valve ( Clutch switching means) 120 ECU (supercharging control means)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02B 37/14 F02B 37/10 F02B 37/16 F02B 39/12

Claims (7)

(57) [Claims] In a turbocharger, an auxiliary drive turbine is provided on a connecting shaft interconnecting a compressor provided in an intake passage and a turbine provided in an exhaust passage, and the auxiliary drive turbine is discharged from an engine accessory to the auxiliary drive turbine. In a supercharger for an engine configured to auxiliary-drive the connection shaft by supplying a fluid to the engine, wherein the supercharged relief is switched between a relief state in which the supercharged air by the turbocharger is relieved and a non-relief state in which the supercharged air is not relieved. Means for increasing the load by driving the engine accessory when the engine is decelerating and in a predetermined operating range to accelerate the connecting shaft and switching the supercharging relief means to a relief state, and And supercharging control means for switching the relief means to a non-relief state. An engine supercharging device. 2. The supercharger according to claim 1, wherein when the operating state of the engine is in a preset fuel cut region, a load by driving the engine accessory is increased. A supercharger for an engine, comprising: 3. The supercharger for an engine according to claim 1, wherein the connecting shaft is divided into a compressor side shaft and a turbine side shaft which are arranged coaxially with each other, and the compressor side shaft and the turbine side shaft are separated from each other. A clutch means that is switched between a connection state in which the motors are connected so as to rotate in conjunction with each other and a disconnection state in which the motors are separated so as to rotate relative to each other is provided. A supercharging device for an engine, wherein the supercharging control means is configured to switch according to the following. 4. A supercharging device for an engine according to claim 3, wherein said supercharging control means is configured to switch said clutch means to a disengaged state when the engine is in a deceleration state and is in a predetermined operating range. Characteristic engine supercharging device. 5. The supercharger for an engine according to claim 3, wherein the clutch means is switched to a connected state when the engine is in a deceleration state and is in a predetermined operating range, and the clutch means is disengaged at the start of engine acceleration. A supercharging device for an engine, wherein the supercharging control means is configured to perform switching. 6. A supercharger for an engine according to claim 3, wherein said clutch means is switched to a disengaged state until a predetermined time elapses from a point in time when the engine decelerates and enters a predetermined operation range, and said predetermined time is maintained. A supercharging device for an engine, wherein the supercharging control means is configured to switch the clutch means to a connected state after a lapse of time, and to switch the clutch means to a disengaged state at the start of acceleration. 7. A supercharging device for an engine according to claim 3, wherein said clutch means includes a fluid pressure clutch switched by a fluid discharged from said engine accessory and a fluid pressure clutch. An engine supercharging device comprising: a clutch switching unit that switches between a state in which the fluid is introduced and a state in which the fluid is interrupted.