JP2698142B2 - Engine turbocharger control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a turbocharger control device for an engine in which a plurality of superchargers are arranged in parallel.

(Prior Art) Conventionally, for example, Japanese Utility Model Publication No. Sho 57-12177, Japanese Patent Laid-Open No. Sho 60-259
As described in Japanese Patent Publication No. 722, etc., two turbochargers, a primary and a secondary, are arranged in parallel in an engine, and an exhaust cut valve and an intake valve are provided on a turbine inlet side and a blower outlet side of a secondary turbocharger. Providing each cut valve,
By opening and closing these cut valves, the turbocharger on the primary side only in the low flow rate region performs supercharging, and the turbocharger on the secondary side operates in the high flow rate region. Engines called formulas are known.

(Problems to be Solved by the Invention) By the way, in the control of the turbocharger in this type of engine, when the secondary turbocharger is shifted from the non-operation state to the operation state, the control of the secondary supercharger is performed. In order to avoid a torque shock or the like due to a response delay, the secondary supercharger is driven before switching. That is, the pre-rotation is conventionally performed. In such a case, the pre-rotation of the secondary-side supercharger is usually performed by opening the exhaust cut valve with the intake relief valve opened and flowing exhaust gas to the secondary-side turbine. However, if the pre-rotation of the secondary turbine is performed by opening the exhaust cut valve with the intake relief valve opened, a large amount of exhaust gas already flows to the secondary side by opening the exhaust cut valve. And the rotation of the primary side drops,
The pre-rotation region cannot be made long enough. Therefore, in such a conventional pre-rotation method, it is difficult to sufficiently increase the rotation speed of the secondary turbocharger before switching to the region where supercharging is performed by the secondary-side supercharger. The torque shock at the time could not be reliably prevented.

The present invention has been made in view of the above problems,
An object of the present invention is to provide a sufficient pre-rotation when switching a turbocharger operated in a high flow rate region from a non-operation state to an operation state, and to reliably reduce torque shock at the time of switching.

(Means for Solving the Problems) In order to achieve the above object, a solution of the present invention according to claim 1 is a first supercharger that operates at least in a low flow rate region of the intake air amount and operates in a high flow rate region. An exhaust cut valve that opens and closes an exhaust passage in which a turbine of the second turbocharger is interposed, in a turbocharged engine in which a second turbocharger of an exhaust turbo type is arranged in parallel. An intake cut valve that opens and closes an intake passage in which a blower of the second supercharger is provided. Further, an operating state detecting means for detecting an operating state of the engine, and receiving the output of the operating state detecting means, opening the exhaust cut valve and the intake cut valve in a high flow rate region and disabling the second supercharger. Switching control means for switching from a non-operation state to an operation state of the second supercharger, pre-rotation means for performing pre-rotation control of the second supercharger, and An intake relief valve for releasing pressure of an intake passage between the intake cut valve and the second supercharger during pre-rotation control of the second supercharger. An intake relief valve control means for closing the intake relief valve before opening the exhaust cut valve and switching the second supercharger to the operating state is provided.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a setting changing means for changing the setting of the closing operation condition of the intake relief valve so as to hasten the closing operation of the intake relief valve during acceleration is provided. And Further, in the invention of claim 3, it is assumed that the first and second superchargers in claim 1 are both turbochargers of an exhaust turbo type. Further, in the invention according to claim 4, the pre-rotation by the pre-rotation means in claim 3 is performed by passing a small amount of exhaust gas through the second supercharger. In addition, in the invention of claim 5, in claim 4, a small amount of exhaust gas passes through the second supercharger by the pre-rotation passage and the pre-rotation control valve provided separately from the exhaust cut valve. Control. According to the invention of claim 6, the opening timing of the intake / exhaust cut valve at the time of the switching operation according to claim 1 is as follows:
It is assumed that the exhaust cut valve is set to open earlier than the intake cut valve.

Further, a solution of the invention according to claim 7 is that an exhaust turbo type first engine operated at least in a low flow rate region of an intake air amount.
Turbocharger and second turbocharged exhaust system operated in high flow rate region
A turbocharger engine in which a first exhaust passage in which a turbine of the first supercharger is interposed and a turbine of the second supercharger are interposed. Second
An exhaust exhaust passage, a communication passage that communicates the upstream of the first supercharger of the first exhaust passage with the upstream of the second supercharger of the second exhaust passage, and a downstream of the communication passage. An exhaust cut valve that opens and closes a second exhaust passage, a first intake passage in which a blower of the first supercharger is interposed, and a second intake passage in which a lower of the second supercharger is interposed And an intake cut valve that opens and closes a second intake passage downstream of the blower of the second supercharger. Further, an operating state detecting means for detecting an operating state of the engine, and receiving the output of the operating state detecting means, opening the exhaust cut valve and the intake cut valve in a high flow rate region and disabling the second supercharger. Switching control means for switching from a non-operation state to an operation state of the second supercharger, pre-rotation means for performing pre-rotation control of the second supercharger, and An intake relief valve for releasing pressure in a second intake passage between the intake cut valve and the second supercharger during pre-rotation control of the second supercharger.
An intake relief valve control means for closing the intake relief valve before opening the exhaust cut valve and switching the second supercharger to the operating state is provided.

(Operation) According to the first to seventh aspects of the present invention, when the engine reaches a predetermined high flow rate region, the exhaust cut valve and the intake cut valve are opened, and the second turbocharger of the exhaust turbo type operates. I do. At this time, the second turbocharger is pre-rotated with the intake relief valve opened before the exhaust cut valve opens. For example, it is pre-rotated by a small amount of exhaust gas passing through the turbine of the second supercharger. This pre-rotation continues until the intake relief valve closes, and the second supercharger operates by opening the exhaust cut valve and the intake cut valve when the rotation is sufficiently increased. Also, during this time, the intake relief valve is closed and the second supercharger is positively jumped into the surging region (flow rate 0), thereby reducing the work of the blower, and in particular, opening the exhaust cut valve and then opening the intake cut valve. By this time, the rotation of the second supercharger is accelerated.

According to the second aspect of the present invention, in addition to the above-described operation, it is possible to quickly jump into the surging region at the time of acceleration to compensate for a delay in rotation increase of the second supercharger.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 3 is a system diagram showing a first embodiment of the present invention applied to a two-rotor rotary piston engine.

In this embodiment, one of the two exhaust passages 4, 5 extending almost straight from the pair of exhaust ports 2, 3 of the rotary piston engine 1 has a first exhaust passage 4 which operates in the entire supercharging region. A turbine 8 of a primary turbocharger 6 as a charger and a turbine 9 of a secondary turbocharger 7 as a second turbocharger that operates only in a high flow rate region in the other second exhaust passage 5. Are arranged respectively. The two exhaust passages 4, 5 merge into a single stream downstream of the turbines 8, 9, and are connected to a silencer (not shown). Also, at the position downstream of the air cleaner 10, the intake passage 11
Is divided into two, a blower 13 of the primary turbocharger 6 is provided in the middle of the first branch passage (first intake passage) 12, and is provided in a middle of the second branch passage (second intake passage) 14. Is provided with a blower 15 of the secondary turbocharger 7. The two branch passages 12 and 14 merge again downstream of the respective blowers 13 and 15 and are connected to the surge tank 17 via the intercooler 16. The downstream side of the surge tank 17 is connected to an intake port (not shown). A throttle valve 18 is provided upstream of the surge tank 17. An air flow meter 19 is provided downstream of the air cleaner as operating state detecting means for detecting the amount of intake air.

At a position immediately downstream of the pair of exhaust ports 2, 3, the two exhaust passages 4, 5 are communicated with each other by a relatively small-diameter communication passage 20 extending in a direction substantially perpendicular to the passages 4, 5.
An exhaust cut valve 21 is provided in the second exhaust passage 5 in which the secondary-side turbine 9 is provided, immediately downstream of the opening position of the communication passage 20. A bypass passage 23 extending from the communication passage 20 and communicating with a combined exhaust passage 22 downstream of the turbines 8 and 9 is provided.In the bypass passage 23, a waste gate valve 25 linked to a diaphragm type actuator 24 is provided. It is arranged. The pressure on the primary side downstream of the blower 6 is introduced into the pressure chamber of the actuator 24 of the waste gate valve 25. Furthermore, the communication passage 20
From the secondary turbine 9 downstream of the exhaust cut valve 21.
A leakage passage 26 communicating with the upstream second exhaust passage 5 is provided, and the leakage passage 26 is provided with an exhaust leakage valve 28 linked to a diaphragm type actuator 27. The pressure downstream of the primary blower 6 is also introduced into the pressure chamber of the actuator 27.

The exhaust cut valve 21 is a diaphragm type actuator 29
The working pressure introduction passage 30 has a solenoid valve 31
Is provided. On the other hand, the secondary turbocharger 7
The intake cut valve 32 is disposed downstream of the blower 15 in the branch passage 14 in which is disposed. The intake cut valve 32 is also linked to another diaphragm-type actuator 33, and an electromagnetic valve 35 is provided in the working pressure introducing passage 34. A blower 15 is provided in the branch passage 14 on the secondary side.
A relief passage 36 for releasing the pressure on the discharge side to the upstream side is provided, and an intake relief valve 37 having a diaphragm-type actuator 37a is provided in the relief passage 36. An electromagnetic valve 39 is also provided in the working pressure introduction passage 38 of the intake relief valve 37. The exhaust cut valve 21, the intake cut valve 32, and the intake relief valve 37 are controlled by the control unit 40 via the respective solenoid valves 31, 35, and 39.

FIG. 4 is a side view showing the structure of the supercharging system of this embodiment. In the case of a two-rotor rotary piston engine, two exhaust ports are arranged side by side and open directly to the rotor housing. Therefore, as shown in FIG. 3, the two primary and secondary turbochargers 6, 7 are integrated. A simple layout that is connected to the engine and directly attached to the engine is possible. The discharge side intake pipe 41 connected to each of the blowers 13 and 15 is connected to an intercooler (not shown) as one pipe. Inlet opening 4 of each blower 13,15
2, 43 are connected to an air cleaner (not shown) via an intake pipe 44. The connected turbochargers 6, 7 are provided with a cooling water pipe 45 which enters from the primary side, passes through to the secondary side, and is connected to a water pump (not shown). An oil pipe 46 for supplying oil is provided. Oil pipe
In 46, a check valve 47 is provided at an inlet position to the secondary turbocharger. In FIG. 4, reference numeral 48 denotes an intake manifold, and reference numeral 49 denotes a junction with an isosource manifold.

In the supercharging system of this embodiment, as shown in FIG. 5, the exhaust cut valve 21 and the intake cut valve 32 are closed in a low flow rate region where the intake air amount is Qa ₁ and the engine speed is rpm _1. As a result, the intake relief valve 37 is open. And Qa
When the line at ₁ , rpm ₁ is reached, the intake relief valve 37 is closed. During this time, the supercharging pressure reaches a predetermined value and the exhaust leakage valve
When 28 opens, a portion of the exhaust enters the secondary turbine 9 and pre-rotates it. And the intake air amount is Qa ₂ ,
When the engine speed reaches the rpm ₂ line, the exhaust cut valve 21 is opened and further accelerated. When the intake air amount reaches Qa ₃ and the engine speed reaches the rpm ₃ line, the intake cut valve 32 opens. Thus, the pre-rotation of the secondary turbocharger
This is performed by a part of the exhaust gas leaking around the exhaust cut valve 21, and by closing the intake relief valve 37 before opening the exhaust cut valve 21, a sufficient pre-rotation period is ensured before switching. The rotation of the secondary turbocharger can be sufficiently increased.

In the case of this embodiment, since the exhaust of each cylinder is guided straight to the primary turbine 8 and the secondary turbine 9 through the separate exhaust passages 4 and 5, there is little exhaust interference. Therefore, especially in the high flow rate region, the exhaust pulse can be used to the maximum, and both the primary turbine and the secondary turbine can be efficiently rotated. Further, in the low flow rate region, the exhaust gases of both cylinders merge through the communication passage 20 and the primary turbine 8 is driven by all the exhaust gases. Therefore, the primary turbine 8 having a sufficiently large capacity is used. , And a small high-speed turbine 9 can be combined. Therefore, the switching frequency in the normal operation range can be suppressed, and the responsiveness at the time of switching on the high flow rate side can be enhanced. Further, since the bypass passage 23 having the wastegate valve 25 is formed so as to extend from the communication passage 20 as described above, the influence of exhaust pulsation on the wastegate valve 25 can be reduced.

Next, a flowchart for executing the control of this embodiment will be described with reference to FIG.

It starts and reads the operating state signals of the engine, such as the amount of intake air and the engine speed.

Then, first, whether the flag 1 is set, that is, the previous state is over the line of Qa ₁ and rpm ₁ shown in FIG.
It is determined whether the line is between Qa ₂ and rmp ₂ .

If the flag 1 is not set, then it is determined whether or not the flag 2 is set, that is, whether the previous state was between the line of Qa ₂ and rpm _{2 and} the line of Qa ₃ and rpm _3. If the flag 2 is not set, whether the flag 3 is set, that is, if the previous state is Qa ₃ ,
It is determined whether or not the area exceeds rpm ₃ . Then, the flag 1 is also the term flag 2 are also flags 3 nor standing, then, beyond Qa ₁ current intake air amount Qa is determined whether the engine speed rpm exceeds the rpm ₁ to, return it if NO, the flags 1 if YES, the closing of the intake relief valve _{S 2 (S 2 = 0)} .

When the flag 1 is set, that is, when the previous time was between the line of Qa ₁ and rpm ₁ and before the line of Qa ₂ and rpm ₂ , next, this time, Qa> Qa ₂ , rpm> rpm ₂ Determine if there is. If YES, it means that the vehicle has shifted to the acceleration side beyond the line of Qa ₂ and rpm ₂ this time.
The upright, open the exhaust cutoff valve _{S 1 (S 1 = 1)} . If NO, it is determined whether Qa <Qa ₁ and rpm <rpm ₁ . If Qa <Qa ₁ , rpm <rpm ₁ , this means that the line of Qa ₁ , rpm ₁ has been shifted to the deceleration side, the flag 0 is set, and the intake relief valve S ₂ is opened (S ₂ =
1).

When it is determined that the flag 2 is on, Qa
> Qa ₃ , rpm> rpm ₃ is determined. And Y
If ES, namely the fact that the transition to this Qa _3, during acceleration beyond the line of rpm _3, flagged 3, opening the intake cut valve S ₃ (S = 1). If NO, then Qa <Qa ₂ , rp
m <whether it is a rpm _2, in other words, to look at whether the transition to the deceleration side beyond the Qa _2, rpm ₂ line, this time Qa _2, rpm ₂
If you have crossed the line, set the flag 1,
The exhaust cut-off valve S ₁ is closed (S ₁ = 0).

When it is determined that the flag 3 is set, it is next determined whether or not Qa> Qa ₃ and rpm> rpm ₃ this time. If YES, do nothing, if NO, this time Q
a <a Qa _3, rpm <that have migrated line of rpm ₃ the deceleration side, this time flags 2 to close the exhaust cutoff valve _{S 1 (S 1 = 0)} .

FIG. 7 is an overall system diagram of a second embodiment of the present invention.

In this embodiment, an engine 101 is a reciprocating two-cylinder engine, and exhaust passages 102 and 103 are provided independently of each other for each cylinder. The turbine 105 of the primary turbocharger 104 is disposed in one of the two exhaust passages 102 and 103, and the turbine 107 of the secondary turbocharger 106 is disposed in the other.
The two exhaust passages 102 and 103 merge into a single stream downstream of the turbines 105 and 107 and are connected to a silencer (not shown). Further, the intake passage 109 is divided into two downstream of an air cleaner (not shown), a blower 111 of the primary turbocharger 104 is provided in the middle of the first branch passage 110, and is provided in a middle of the second branch passage 112. Is provided with a blower 113 of the secondary turbocharger 107. These branch passages
110 and 112 are formed so as to face each other at the branch portion and extend substantially straight on both sides. Further, the two branch passages 110 and 112 merge again downstream of the respective blowers 111 and 113. Then, an intercooler 114 is disposed in the intake passage 109 that has become one again, and a surge tank 115 is disposed downstream of the intercooler 114, and a throttle valve 116 is disposed between the intercooler 114 and the surge tank 115. Has been established. Also, intake passage 1
The downstream end of 09 branches into two independent intake passages 117 and 118 corresponding to each cylinder of the engine 101, and is connected to each intake port (not shown). In addition, fuel injection valves 119 and 120 are disposed in these independent intake passages 117 and 118, respectively.

An air flow meter 121 that detects the amount of intake air is provided upstream of the intake passage 109 at a position upstream of a branch portion of the first and second branch passages 110 and 112.

The two exhaust passages 102 and 103 are communicated with each other by a relatively small-diameter communication passage 122 upstream of both the primary and secondary turbochargers 104 and 105. The exhaust passage 1 in which the secondary turbine 107 is disposed
In 03, an exhaust cut valve 123 is provided immediately downstream of the opening position of the communication passage 122. A bypass passage 125 extending from the middle of the communication passage 122 and communicating with a combined exhaust passage 124 downstream of the turbines 105 and 107 is provided. The bypass passage 125 has a wastegate valve 127 linked to a diaphragm-type actuator 126. Are arranged. A leakage passage 128 is provided for communicating the upstream portion of the waste gate valve 127 of the bypass passage 125 and the exhaust cut valve 123 downstream of the exhaust passage 103 connected to the secondary turbine 107, and the leakage passage 128 has a diaphragm type. An exhaust leak valve 130 linked to the actuator 129 is provided.

The exhaust cut valve 123 is a diaphragm type actuator 1
It is linked to 31. On the other hand, an intake cut valve 132 is provided downstream of the blower 113 in the branch passage 112 where the blower 113 of the secondary turbocharger 106 is provided. The intake cut valve 132 is constituted by a butterfly valve, and is also linked to a diaphragm type actuator 133. Further, a relief passage 134 is provided in the branch passage 112 on the secondary side so as to bypass the blower 113, and a diaphragm-type intake relief valve 135 is disposed in the relief passage 134.

The pressure chamber of the actuator 129 that operates the exhaust leak valve 130 is connected to the primary turbocharger 1 via a conduit 136.
The blower 111 is connected to the downstream side of the blower 111 of the branch passage 110 in which the blower 111 is disposed. When the pressure downstream of the blower 111 becomes equal to or higher than a predetermined value, the actuator 129 is operated to open the exhaust leak valve 130, thereby causing the exhaust cut 123
A small amount of exhaust gas when bypass is closed
It flows through 128 and is supplied to the secondary side turbine 107. Therefore, secondary turbocharger 106 starts rotating before exhaust cut valve 123 opens. During this time, the rotation of the secondary turbocharger 106 is increased by opening the intake relief valve as described later, the transient response when the exhaust cut valve is opened is improved, and the torque shock is reduced.

The pressure chamber of the actuator 133 for operating the intake cut valve 132 is connected by a conduit 137 to the output port of an electromagnetic solenoid type three-way valve 138. Also, the exhaust cut valve 123
Is connected to the output port of another three-way valve 140 of the electromagnetic solenoid type via a conduit 139. Further, the pressure chamber of the actuator 141 that operates the intake relief valve 135 is connected to an output port of another three-way valve 143 of an electromagnetic solenoid type by a conduit 142.
The intake relief valve 135 is connected to the exhaust cut valve 123 as described later.
The relief passage 134 is kept open until a predetermined time before the intake cut valve 132 is opened. Thus, when the secondary turbocharger 106 is pre-rotated by the exhaust gas flowing through the leakage passage 128, the pressure upstream of the intake cut valve 132 is suppressed from rising and entering the surging region. Increase rotation.

The actuator 1 for operating the wastegate valve 127
26 is another three-way valve 145 of the electromagnetic solenoid type by a conduit 144
The output port is connected.

The above four electromagnetic solenoid type three-way valves 138,140,143,145
Is controlled by a control unit 146 configured using a microcomputer. To the control unit 146, in addition to the engine speed R and the intake air amount Q, the throttle opening TVO, the supercharging pressure P1 downstream of the primary-side blower 111, and the like are input, and based on these, the following control is performed.

One input port of the electromagnetic solenoid type three-way valve 138 for controlling the intake cut valve 132 is connected to a negative pressure tank 148 via a conduit 147, and the other input port is connected to a differential pressure detection valve described later via a conduit 149. It is connected to 150 output ports 170. The intake negative pressure downstream of the throttle valve 116 is introduced into the negative pressure tank 148 via a check valve 151. Further, one input port of the three-way valve 140 for controlling the exhaust cut valve is open to the atmosphere, and the other input port is connected to the conduit 15.
2, the conduit 14 connected to the negative pressure tank 148.
Connected to 7. On the other hand, one input port of the three-way valve 143 for controlling the intake relief valve 135 is connected to the negative pressure tank 148, and the other input port is opened to the atmosphere via a conduit 153. Also, one input port of the three-way valve 145 for controlling the wastegate valve 127 is open to the atmosphere,
The other input port is connected by a conduit 154 to the conduit 136 which communicates with the primary side blower 111 downstream.

As shown in FIG. 8, the differential pressure detecting valve 150 has a casing 161 in which two first and second diaphragms 16 are provided.
It is divided into three chambers 164,165,166 by 2,163.
A first input port 167 is opened in the first chamber 164 on one end side, and a compression spring 168 is disposed between the inner surface of the end of the casing 161 and the first diaphragm 162. . A second input port 169 is opened in the middle second chamber 165, an output port 170 is provided in the center of the end wall of the casing 161, and a third input port 169 is provided in the third chamber 166 on the other end side. The atmosphere release port 171 is open. And the first
Of the third chamber 166 extends toward the output port 170 of the third chamber 166.
172 is fixed.

As shown in FIG. 7, the first input port 167 is connected to the downstream side of the intake cut valve 132 by a conduit 173, and the supercharging pressure P1 downstream of the primary side blower 111 is supplied to the first chamber 164.
To be introduced. Also, the second input port 169 is connected by a conduit 174 upstream of the intake cut valve 132, thus
The pressure P2 on the upstream side of the intake cut valve 132 when the intake cut valve 132 is closed is introduced. When the difference between the pressures P1 and P2 introduced from the two input ports 167 and 169 is equal to or greater than a predetermined value, the valve element 172 opens the output port 170. This output port 170 is connected via a conduit 149 to one of the input ports of a three-way valve 138 for controlling the intake cut valve 132.
Therefore, in a state where the three-way valve 138 connects the conduit 137 connected to the pressure chamber of the actuator 133 for operating the intake cut valve 132 to the conduit 149 connected to the output port of the differential pressure detection valve 150, the differential pressure P2-P1 Becomes larger than a predetermined value,
Air is introduced into the actuator 133, and the intake cut valve 132 is opened. Also, the three-way valve 138 is
When the conduit 137 on the third side is communicated with the conduit 147 connected to the negative pressure tank 148, a negative pressure is supplied to the actuator 133, and the intake cut valve 132 is closed.

On the other hand, the exhaust cut valve 123 has a three-way valve 140 for controlling the exhaust cut valve 123 and an actuator 131 for operating the exhaust cut valve 123.
When the conduit 139 leading to the pressure chamber is connected to the conduit 152 on the negative pressure tank 148 side, the actuator 131 is closed by supplying a negative pressure. Also, the three-way valve 140
When the exhaust gas releases the conduit 139 to the atmosphere, the exhaust cut valve 123 is opened, and supercharging is performed by the secondary turbocharger 106.

FIG. 9 is a control map showing the open / closed state of the intake cut valve 132, the exhaust cut valve 123, the intake relief valve 135, and the wastegate valve 127 together with the open / closed state of the exhaust leak valve 130. This map is stored in the control unit 146, and based on this map, the above-mentioned four electromagnetic solenoid type three-way valves 138, 140, 143, 145 are controlled.

In a region where the engine speed R is low or the intake air amount Q is small, the intake relief valve 135 is opened, and the exhaust leakage 130 is opened, so that the secondary turbocharger 106 is pre-rotated. Then, when the engine speed reaches R2 or the intake air amount reaches the line of Q2,
The intake relief valve 135 is closed, and then the exhaust cut valve 1
Until 23 opens, the pressure downstream of the secondary blower 113 increases. Then, when the exhaust gas reaches the Q4-R4 line, the exhaust cut valve 123 opens, and then reaches the Q6-R6 line and opens the intake cut valve 132, so that the secondary turbocharger 1
The supercharging by 06 starts and enters the supercharging area by both the primary and secondary turbochargers at the Q6-R6 line.

The intake cut valve 132, the exhaust cut valve 123, and the intake relief valve 135 have some hysteresis from the high flow side to the low flow side, that is, Q5-R5, Q-3- shown by broken lines in FIG.
It switches on each line of R3, Q1-R1.

The broken portion of each line is on a so-called no-load line or load-load line.

The wastegate valve 127 is opened when the engine speed R and the throttle opening TVO are equal to or higher than a predetermined value, and when the supercharging pressure P1 downstream of the primary blower is equal to or higher than a predetermined value.

Further, in this embodiment, the timing of closing the intake relief valve 135 is accelerated with respect to the normal transition at the time of acceleration, that is, as shown by the dashed line in FIG. 9, the Q2-R2 line is shifted to the low flow rate side, As a result, the discharge pressure on the secondary side is increased to just before the surging region during the pre-rotation. Accordingly, supercharging control with excellent transient response and less torque shock is performed.

FIGS. 10 and 11 are flowcharts for executing the above control of the intake cut valve 123, the exhaust cut valve 132 and the intake relief valve 135 in the second embodiment. S indicates each step. Further, F is a flag, and the meaning of this flag state (F = 1 to 6) is as shown in FIG. 9, and the previous transition is Q, respectively.
1-The transition from the high flow side to the low flow side of the R1 line (F = 1), Q2- The transition from the low flow side to the high flow side of the R2 line (F = 2), Q3- The transition from the high flow side to the low flow side of the R3 line (F = 3), and the transition from the low flow side to the high flow side of the Q4-R4 line (F =
4) The transition from the high flow rate side of the Q5-R line to the low flow rate side (F = 5), and the transition from the low flow rate side to the high flow rate side of the Q6-R6 line (F = 6) , Respectively. Hereinafter, description will be made step by step.

First, in FIG. 10, the process is started, and initialization (initialization) is performed in S1. At this time, the flag is set to 1.

Next, at S2, the intake air amount Q and the engine speed R are input. Then, map values Q1 to Q6 and R1 to R6 are read in S3.

Next, in S4, the change rate dQ / dt of the intake air amount Q is set to a predetermined value A.
Acceleration determination is performed depending on whether the value is greater than the value.

If dQ / dt> A, that is, during acceleration, then S
Going to 5, the Q2 and R2 corresponding to the closing timing of the intake relief valve 135 are reduced and corrected by predetermined ΔQ2 and ΔR2. Nothing is done except when accelerating. Then, go to S6.

In S6, it is checked whether or not the flag F is 1, that is, whether or not the previous transition was from the high flow side to the low flow side of the Q1-R1 line. Note that initially F = 1, so this determination is YES.

If F = 1, then enter S7, this time Q
Is greater than Q2, if NO, then
In S8, it is checked whether R is larger than R2 this time. And S7
If YES in S8 or YES in S8, the process proceeds to S9, where the flag F is set to 2, and in S10, the intake relief valve is controlled to be closed (a positive pressure is introduced into the actuator). Also, S7 and
If the determination in S8 is NO, the process returns.

If the determination in S6 is NO, the process proceeds to S11 and the flag F
Is an even number, that is, whether the previous transition has occurred on any line from the low flow rate side to the high flow rate side.

If YES in S11, the flow goes to S12 to determine whether or not F = 2, that is, whether or not the previous shift was from the low flow rate side to the high flow rate side of the Q2-R2 line.
If so, go to S13.

In S13, it is determined whether or not Q is greater than Q4 this time. If NO, then in S14, it is checked whether or not R this time is greater than R4. And either S13 or S14 is YE
If it is S, go to S15, set the flag F to 4, and
Control to open the exhaust cut in step 6 (introduce negative pressure to the actuator).

Also, when both determinations of S13 and S14 are NO,
Go to S17 to see if Q is less than Q1 this time.

If YES in S17, it is checked in S18 whether R is smaller than R1 this time. If YES, the process proceeds to S19, where the flag F is set to 1, and control is performed to open the intake relief valve in S20 (a negative pressure is introduced into the actuator). If the determinations in S17 and S18 are both NO, the process returns.

If the determination in S12 is NO, the process proceeds to S21 and the flag F is set to 4
That is, it is determined whether the previous transition was a transition from the low flow rate side to the high flow rate side of the Q4-R4 line.

If YES in S21, it is checked in S22 whether this time Q is larger than Q6. If NO, then in S23, it is checked whether this time R is larger than R6. If YES in either S22 or S23, the flow proceeds to S24, where the flag F is set to 6, and in S25, control is performed to open the intake cut valve (the actuator is connected to the differential pressure detection valve side).

If NO in S23, the process goes to S26 to determine whether Q is smaller than Q3. If YES, it is determined in S27 whether R is smaller than R3. And if YES in S27,
The flow goes to S28 to set the flag F to 3, and in S29, control to close the exhaust cut valve is performed (atmosphere is introduced into the actuator).

When the determination in S21 is NO, F = 6, that is, the previous transition is a transition from the low flow rate side to the high flow rate side of the Q6-R6 line. Q
Is smaller than Q5, and if YES, then in S31, it is determined whether this time R is smaller than R5.
If YES, the process proceeds to S32, where the flag F is set to 5, and control is performed to close the intake cut valve in S33 (a negative pressure is introduced into the actuator). If NO in either S30 or S31, the process returns.

Next, the flow when the determination in S11 is NO will be described with reference to FIG.

If NO in S11, the flow proceeds to S41 to determine whether or not the flag F is 3, that is, whether or not the previous transition was from the high flow side to the low flow side of the Q3-R3 line. If YES, then it is determined in S42 whether or not the current Q is smaller than Q1, and if YES, it is determined in S43 whether or not R this time is smaller than R1. And if YES, S44
To set the flag F to 1, and then control to open the exhaust cut valve in S45.

If NO in either S42 or S43, go to S46, see if Q is greater than Q4, if NO, go to S4
At 7, it is determined whether R is greater than R4. And S46
Alternatively, if YES in any of S47, the flow proceeds to S48 to set the flag F to 4, and then in S49, control is performed to open the exhaust cut valve. If NO in S47, the process returns.

If NO in S41, it means that F = 5. In this case, go to S50 to determine whether Q is smaller than Q3. If YES, determine whether R is smaller than R3 in S51. I do. If YES in S51, the flag F is set to 3 in S52, and then control is performed to close the exhaust cut valve in S53.

If NO in S50 or S51, S54
To determine whether Q is greater than Q6. If NO, then in S55, check if R is greater than R6.
If YES in S54 or S55, S56
To set the flag F to 6, and then control to open the intake cut valve in S57.

 If NO in S55, the routine returns.

Note that, in both of the above embodiments, the case where the exhaust leak valve is disposed in the leak passage that allows the exhaust gas to pass to the turbine on the secondary side has been described, but the present invention is directed to the case where such an exhaust leak valve is not provided. Can also be applied. Further, in both of the above embodiments, a butterfly valve operated by an actuator is used as the intake cut valve, but the present invention can also be applied to a valve using a check valve type intake cut valve. is there.

The present invention can be implemented in various other modes.

(Effects of the Invention) Since the inventions of claims 1 to 7 are configured as described above, when the turbocharger to be operated in the high flow rate region is switched from the non-operation state to the operation state, the turbocharger is set in advance. The rotation of the machine can be sufficiently increased, and the torque shock at the time of switching can be reliably reduced.

According to the second aspect of the invention, in addition to the above effects,
By accelerating the closing operation of the intake relief valve during acceleration, it is possible to sufficiently increase the discharge side pressure of the turbocharger before switching the turbocharger to the operating state, thereby improving the transient response.

[Brief description of the drawings]

1 and 2 show the overall configuration of the present invention, FIG. 3 shows the overall system of the first embodiment of the present invention, FIG. 4 shows the structural view (side view) of the same embodiment, and FIG. FIG. 6 is a flow chart for executing the control of the embodiment, FIG. 7 is an overall system diagram of a second embodiment of the present invention, and FIG. 8 is a differential pressure detection in the embodiment. FIG. 9 is a cross-sectional view of the valve, FIG. 9 is a control characteristic diagram of the embodiment, and FIGS. 10 and 11 are flowchart diagrams for executing the control of the embodiment. 1,101… Engine, 6,104 …… Primary turbocharger, 7,106 …… Secondary turbocharger, 21,123 …… Exhaust cut valve, 29,33,37a, 131,133,141 …… Actuator, 32,132 …… Intake cut valve, 36,134… … Relief passage, 37,135 …… Intake relief valve, 40,146 …… Control unit.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasushi Niwa 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-59-145327 (JP, A) JP-A-61 -190121 (JP, A) JP-A-60-259722 (JP, A) JP-A-60-166716 (JP, A) JP-A-59-154827 (JP, U) JP-A-60-178329 (JP, U) ) Jinsho 57-12177 (JP, Y2)

Claims (7)

(57) [Claims] 1. A turbocharger having at least a first supercharger operated in a low flow rate region of an intake air amount and a second turbocharger of an exhaust turbo type operated in a high flow rate region. In the engine, an exhaust cut valve that opens and closes an exhaust passage in which a turbine of the second supercharger is provided, and an intake cut valve that opens and closes an intake passage in which a blower of the second supercharger is provided Operating state detecting means for detecting an operating state of the engine; receiving an output of the operating state detecting means, and opening the exhaust cut valve and the intake cut valve in a high flow rate region to move the second supercharger from an inoperative state. Switching control means for switching to an operation state; pre-rotation means for performing pre-rotation control of the second supercharger prior to switching from a non-operation state to an operation state of the second supercharger; Intake cut during turbocharger pre-rotation control An intake relief valve for releasing the pressure in an intake passage between the first supercharger and the second supercharger; and closing the intake relief valve before opening the exhaust cutoff valve and switching the second supercharger to an operating state. A turbocharger control device for an engine, comprising: intake relief valve control means. 2. A turbocharger for an engine according to claim 1, further comprising setting change means for changing a setting of a closing operation condition of the intake relief valve so as to hasten the closing operation of the intake relief valve during acceleration. Machine control device. 3. The turbocharger control apparatus for an engine according to claim 1, wherein both the first and second superchargers are turbochargers of an exhaust type. 4. The turbocharger control device for an engine according to claim 3, wherein the pre-rotation by the pre-rotation means is performed by passing a small amount of exhaust gas through the second supercharger. 5. A small amount of exhaust gas is controlled by a pre-rotation passage and a pre-rotation control valve provided separately from the exhaust cut valve so that a small amount of exhaust gas passes through the second supercharger. A turbocharger control device for an engine as described in the above. 6. The valve according to claim 1, wherein the opening timing of the intake / exhaust cut valve during the switching operation is set so that the exhaust cut valve is opened earlier than the intake cut valve.
A turbocharger control device for an engine as described in the above. 7. An exhaust turbo-type first supercharger operating at least in a low flow rate region of the intake air amount and a second exhaust turbo type supercharger operating in a high flow rate range are arranged in parallel. In the supercharged engine, a first exhaust passage in which a turbine of the first supercharger is provided, a second exhaust passage in which a turbine of the second supercharger is provided, 1 exhaust passage upstream of the first supercharger and the second
A communication passage communicating the exhaust passage with the upstream side of the second supercharger, an exhaust cut valve opening and closing a second exhaust passage downstream of the communication passage, and a blower of the first supercharger interposed therebetween A first intake passage, a second intake passage in which a blower of the second supercharger is interposed, and an intake cut valve for opening and closing a second intake passage downstream of the blower of the second supercharger. Operating state detecting means for detecting an operating state of the engine; receiving an output of the operating state detecting means, and opening the exhaust cut valve and the intake cut valve in a high flow rate region to move the second supercharger from an inoperative state. Switching control means for switching to an operation state; pre-rotation means for performing pre-rotation control of the second supercharger prior to switching from a non-operation state to an operation state of the second supercharger; The intake cut valve and the second supercharger during the pre-rotation control of the supercharger An intake relief valve that releases the pressure of the second intake passage between the intake air release valve and an intake relief valve control unit that closes the intake relief valve before opening the exhaust cut valve and switching the second supercharger to an operating state. A turbocharger control device for an engine, comprising: