JPH0357823A - Intake control device of engine with supercharger - Google Patents

Abstract

PURPOSE:To prevent a drop down of torque by controlling an intake relief valve so as to be early closed at the time of transfer to a high intake amount region from a low intake amount region, in the case of an engine in which a plurality of superchargers are provided with some of them inoperative in accordance with an intake amount. CONSTITUTION:In an engine in which the first and second turbosuperchargers 204, 206 are parallelly arranged, an exhaust cut valve 223 in an exhaust passage 203, in which a turbine 207 of the second supercharger 206 is arranged, is opened only in a high intake amount region, and the second supercharger 206 is actuated. Here in an exhaust leak passage 228 which bypasses the exhaust cut valve 223, an exhaust snifting valve 230, opened only at the time of transfer to the high intake amount region, is interposed. While in a relief passage 234 for bypassing a blower 213, an intake relief valve 235, opened at the time of transfer to the high intake amount region, is provided. A control is performed such that the lower in a speed shift is a shift position the earlier the timing of closing the intake relief valve 235, during the time from opening the exhaust snifting valve 230 to opening the exhaust cut valve 223, is advanced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention includes a plurality of superchargers, and operates or disables some of the exhaust turbo superchargers depending on the intake air amount of the engine. The present invention relates to an air intake control device for a supercharged engine.

(Prior Art) Conventionally, in this type of supercharged engine, turbines of a primary exhaust turbo supercharger and a secondary exhaust turbo supercharger are arranged in parallel in an exhaust passage, as disclosed in, for example, Japanese Utility Model Application Publication No. 178329/1983. The floors of these two exhaust turbo superchargers are connected to the intake passage of the engine, and an exhaust cut valve is installed in the exhaust passage on the upstream side of the turbine of the secondary turbo supercharger, so that the intake air amount is lower than the set value. When the exhaust gas is low, the exhaust gas cut valve is closed to disable the secondary turbocharger, and the exhaust gas from the exhaust passage is intensively supplied to the turbine of the primary turbocharger to ensure high boost pressure. When the amount exceeds the set value, the exhaust cut valve is opened to operate the secondary turbo supercharger, and the exhaust gas from the exhaust passage is supplied to the turbines of the two exhaust turbo superchargers to ensure the intake absorption amount. However, there is a known system that obtains an appropriate boost pressure.

(Problem to be Solved by the Invention) Incidentally, in such a supercharged engine, an exhaust leakage passage that bypasses an exhaust cut valve is provided in the exhaust passage, and an exhaust leakage valve is provided in the exhaust leakage passage to reduce intake air intake. Transition from the air amount region to the high intake air amount region In particular, by opening the exhaust leak valve and guiding a part of the exhaust gas supplied to the turbine of the primary turbo supercharger to the turbine of the secondary turbo supercharger, the exhaust gas can be reduced. The relief adjusts the supercharging pressure characteristics of the primary turbo supercharger, and the exhaust gas runs up the secondary turbo supercharger to give it 1,000 revolutions, improving the start-up of the secondary turbo supercharger in high intake air volume ranges. What is done is done.

In that case, the blower of the secondary turbo supercharger performs work due to the 1,000 revolutions of the secondary turbo supercharger, and the blower becomes hot. Therefore, an intake relief passage is provided in the intake passage dedicated to the secondary turbocharger by bypassing the blower of the secondary turbocharger, and an intake relief valve is installed in the intake relief passage, thereby changing the range from low intake air amount to high intake air amount. At the time of transition to this region, the intake relief valve is opened to circulate air through the blower to prevent the blower from becoming hot.

On the other hand, in such a supercharged engine, when the secondary turbo supercharger switches from inoperation to operation during a transition from a low intake air amount region to a high intake air amount region, such as during acceleration, the secondary turbo supercharger There is a need to build up supercharging pressure from a turbocharger as quickly as possible, eliminate torque drop, reduce torque shock, and improve acceleration response.

The present invention has been made with attention to these points,
The purpose of this is to close the intake relief valve early from the pre-rotation of the secondary turbocharger when transitioning from the low intake air amount area to the high intake air amount area. Increase the rotation and pressure of
The purpose is to quickly build up boost pressure from the secondary turbocharger.

In that case, when the transmission is shifted to a low gear position, the engine speed increases rapidly, so even if the intake relief valve is closed early as described above, the rotation of the secondary turbo supercharger and There is a risk that the pressure will not rise sufficiently.

Therefore, an object of the present invention is to reliably obtain the effect of early closing of the intake relief valve regardless of the shift position.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a short period between the opening of the exhaust leakage valve and the opening of the exhaust cut valve at the time of transition from the low intake air amount region to the high intake air amount region. During this period, the intake relief valve is closed, and the lower the shift position is, the earlier the intake relief valve closes.

Specifically, the solution taken by the present invention is to arrange a plurality of superchargers including an exhaust turbo supercharger in parallel in the intake passage, and at least one of the exhaust turbo superchargers is connected to a secondary turbo supercharger. Equipped with a supercharger that is equipped with an exhaust cut valve in the exhaust passage dedicated to the secondary turbo supercharger as a feeder, and opens the exhaust cut valve only in the high intake air volume region of the engine to operate the secondary turbo supercharger. Assuming an engine. In contrast, there is an exhaust leakage passage provided in the exhaust passage bypassing the exhaust cut valve, and an exhaust gas provided in the exhaust leakage passage that opens when transitioning from a low intake air amount area to a high intake air amount area. A leakage valve, an intake relief passage provided in the intake passage dedicated to the secondary turbocharger by bypassing the blower of the secondary turbocharger, and an intake relief passage provided in the intake relief passage, which bypasses the blower of the secondary turbocharger and is provided in the intake relief passage, which allows high intake air to flow from a low intake air amount region to a high intake air amount. The intake relief valve opens when transitioning from the low intake air volume range to the high intake air volume range, and the intake relief valve closes between the opening of the exhaust leak valve and the opening of the exhaust cut valve when transitioning from the low intake air volume range to the high intake air volume range. a shift position detecting means for detecting a shift position of the transmission; and an intake air relief system which receives the output of the shift position detecting means, and provides intake relief during the period from when the exhaust leak valve opens to when the exhaust cut valve opens as the shift position becomes lower. The structure includes a correction means for correcting the control means so that the valve closes at an earlier timing.

(Function) With the above configuration, in the present invention, when transitioning from a low intake air amount region to a high intake air amount region, the exhaust leakage valve opens and a part of the exhaust gas supplied to the turbine of the primary turbocharger is released. The exhaust gas is guided to the turbine of the secondary turbocharger, where the exhaust gas is relieved and the secondary turbocharger is pre-rotated.

At that time, the intake relief valve opens and air circulates through the blower, preventing the floor from becoming too hot.

In that case, the intake relief valve closes under the control of the control means between when the exhaust leakage valve opens and when the exhaust cut valve opens, so that the intake relief valve remains open for a predetermined period after the exhaust leakage valve opens and the intake air is The relief valve ensures the blower's ability to prevent overheating. Moreover, since the intake relief valve closes early during the pre-rotation of the secondary turbo supercharger before the exhaust cut valve opens, when the rotation and pressure of the secondary turbo supercharger increases and the exhaust cut valve opens, Boost pressure builds up quickly from the secondary turbocharger,
There is no drop in torque, reducing torque shock and increasing acceleration response.

Furthermore, the control means is corrected by the correction means based on the detection by the shift position detection means, so that the lower the shift position, the timing of closing the intake relief valve between when the exhaust leak valve opens and when the exhaust cut valve opens. Even when downshifting to a low speed gear where the engine speed increases quickly, the intake relief valve closes at 1,000 rotations of the secondary turbocharger, and the closing time of the secondary turbocharger is ensured. The rotation and pressure increase sufficiently, the boost pressure from the secondary turbocharger rises quickly, there is no drop in torque, the torque shock is reduced, and the acceleration response is increased.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a device equipped with an intake control device according to an embodiment of the present invention.
This figure shows a rotary piston engine with a rotary type supercharger. In FIG. 1, 201 is an engine, and exhaust passages 202 and 203 are provided independently of each other. And these two exhaust passages 202, 203
On one side is the turbine 2 of the primary turbocharger 204.
05, and a secondary turbo supercharger 206 on the other side.
turbines 207 are respectively arranged. That is, in this engine 201, each exhaust passage 202,
203 is independently connected to primary and secondary exhaust turbo superchargers 204, 206 and turbines 205, 207.
By guiding both exhaust turbo superchargers 204, 206
The exhaust dynamic pressure is applied to both turbines 205 in the region where supercharging is performed by
, 207 to improve supercharging efficiency. The two exhaust passages 202 and 203 merge into one exhaust passage 224 downstream of both turbines 205 and 207.

Further, the intake passage 209 is divided into two downstream of an air cleaner (not shown), and the blower 211 of the primary turbo supercharger 204 is in the middle of the first branch passage 210, and the blower 211 of the primary turbo supercharger 204 is in the middle of the second branch passage 212. The blower 213 of the secondary turbo supercharger 206 is installed. These branch passages 210 and 212 are formed so as to face each other at the branch part and extend substantially in a straight line on both sides. Also,
The two branch passages 210 and 212 are connected to each blower 211, 21.
It rejoins downstream of 3. Then, an intercooler 214 is disposed in the intake passage 209, which has become one again, and a surge tank 215 is disposed downstream of the intercooler 214, and a throttle valve 216 is disposed between the intercooler 214 and the surge tank 215. It is set up. Further, the downstream end of the intake passage 209 branches into two independent intake passages 217 and 218 corresponding to each section of the engine 201, and is connected to each intake port (not shown). Each of these independent intake passages 217 and 218 has a fuel injection valve 219,
220 are arranged.

On the upstream side of the intake passage 209, an air flow meter 221 is provided upstream of the branch of the first and second branch passages 210, 212 to detect the amount of intake air.

The two exhaust passages 202, 203 are communicated with each other by a relatively small diameter communication passage 222 upstream of both the primary and secondary turbo superchargers 204, 205. In the exhaust passage 203 in which the secondary turbine 207 is disposed, an exhaust cut valve 223 is provided immediately downstream of the opening position of the communication passage 222. Further, a turbine 205, which extends from the middle of the communication path 222,
A waste gate passage 225 is formed which communicates with the combined exhaust passage 224 downstream of 207, and the waste gate passage 22
5 is provided with a waste gate valve 227 to which a diaphragm type actuator 226 is linked. An exhaust leakage passage 228 is formed that communicates the wastegate valve 227 upstream part of the wastegate passage 225 with the exhaust cut valve 223 downstream of the exhaust passage 203 connected to the secondary turbine 207. Diaphragm actuator 2
An exhaust leak valve 230 linked to 29 is provided.

The exhaust cut valve 223 is linked to a diaphragm type actuator 231. On the other hand, the branch passage 2 in which the blower 213 of the secondary turbocharger 206 is disposed
12, an intake cut valve 232 is provided downstream of the floor 213. This intake cut valve 232 is composed of a butterfly valve, and is also driven by a diaphragm type actuator 2.
33. Further, a relief passage 234 is formed in the branch passage 212 on the secondary side so as to bypass the blower 213.
4 is provided with a diaphragm type intake relief valve 235.

The actuator 22 that operates the exhaust leak valve 230
The pressure chamber 9 is connected via a conduit 236 to a branch passage 21 in which a blower 211 of a brimary turbo supercharger 204 is disposed.
It is connected downstream of the blower 211 of No. 0. This Bro72
When the pressure on the downstream side of No. 11 exceeds a predetermined value, the actuator 229 operates and the exhaust leakage valve 230 opens, thereby allowing a small amount of exhaust gas to pass through the exhaust leakage passage 228 when the exhaust cut valve 223 is closed. It flows and is supplied to the turbine 207 on the secondary side. Therefore, the secondary turbo supercharger 206 has the exhaust cut valve 223
Starts rotation before opening.

The actuator 23 that operates the intake cut valve 232
The pressure chamber No. 3 is connected to an output port of an electromagnetic solenoid type three-way valve 238 by a conduit 237. Further, the actuator 231 that operates the exhaust cut valve 223 is
Another three-way valve 240 of the electromagnetic solenoid type is connected to the conduit 239.
connected to the output port of the Furthermore, the pressure chamber of the actuator 241 that operates the intake relief valve 235 is
Another three-way valve 243 of electromagnetic solenoid type is connected to the conduit 242.
connected to the output boat. Intake relief valve 235
The relief passage 234 is kept open until a predetermined time before the exhaust cut valve 223 and the intake cut valve 232 open. Thereby, when the secondary turbo supercharger 206 is pre-rotated by the exhaust gas flowing through the exhaust leakage passage 228, air is circulated through the blower 213 of the secondary turbo supercharger 206, thereby preventing the blower 7213 from becoming too hot. , the pressure upstream of the intake cut valve 232 is prevented from rising and entering the surging region.

The actuator 226 that operates the wastegate valve 227 is connected by a conduit 244 to the output port of another three-way valve 245 of the electromagnetic solenoid type.

The above six electromagnetic solenoid type three-way valves 238, 240, 2
43, 245 and the two fuel injection valves 219, 220 are controlled by a control unit 246 configured using a microcomputer. The control unit 246 includes an output signal of the engine rotation speed sensor,
In addition to the output signal of the air flow meter 221, the throttle opening, the supercharging pressure P1 downstream of the blower 211, and the like are input. Further, a transmission (not shown) is connected to the engine 201, and the transmission is provided with a shift sensor 253 as a shift position detection means for detecting the shift position of the transmission. The signal from this shift sensor 253 is also input manually to the control unit 246. Based on these signals, control as described below is performed.

One manual boat of the electromagnetic solenoid type three-way valve 238 for controlling the intake cut valve 232 is connected to a negative pressure tank 248 via a conduit 247, and the other input boat is connected to a negative pressure tank 248 via a conduit 247.
49 to the output port 27 of the differential pressure detection valve 250, which will be described later.
Connected to 0.

Intake negative pressure downstream of the throttle valve 216 is introduced into the negative pressure tank 248 via a check valve 251 . Further, one input port of the three-way valve 240 for controlling the exhaust cut valve is open to the atmosphere, and the other input port is
It is connected via a conduit 252 to the conduit 247 which is connected to the negative pressure tank 248 . On the other hand, one input port of the three-way valve 243 for controlling the intake relief valve 235 is connected to the negative pressure tank 248, and the other input port is open to the atmosphere. In addition, the waste gate valve 227
One input port of the three-way control valve 245 is open to the atmosphere, and the other input port is connected by a conduit 254 to the conduit 236 that communicates with the downstream side of the prower 211 on the blooming side.

As shown in FIG. 2, the differential pressure detection valve 250 has three chambers 264, 265, and
It is divided into 66 sections. A first input port 267 is opened in the first chamber 264 at one end, and the inner surface of the end of the casing 261 and the first diaphragm 26
A compression spring 268 is disposed between the two. In addition, a second manual port 269 is provided in the second chamber 265 in the middle.
In the third chamber 266 on the other end side, an output port 270 is opened in the center of the end wall of the casing 261, and an atmosphere release boat 271 is opened in the side wall. The first diaphragm 262 includes a second diaphragm 26.
A valve body 272 is fixedly provided, passing through the third chamber 266 and extending toward the output port 270 of the third chamber 266.

The first input port 267 is connected to the second input port 267 by a conduit 273.
As shown in the figure, it is connected to the downstream side of the intake cut valve 232, and introduces the supercharging pressure P1 downstream of the intake blower 7211 into the first chamber 264.

The second input boat 269 is also connected upstream of the intake cut valve 232 by a conduit 274, so that the second input boat 269 is connected upstream of the intake cut valve 232 when the intake cut valve 232 is closed.
The upstream pressure P2 is introduced. Pressures Pi and P introduced from these two-man powered boats 267 and 269
2 (P2-PI) exceeds a predetermined value, the valve body 27
2 opens output port 270. This output port 270 is connected via a conduit 249 to one of the input ports of a three-way valve 238 for controlling the intake cut valve 232. Therefore, when the three-way valve 238 is turned on, the conduit 2 connected to the pressure chamber of the actuator 233 for operating the intake cut valve 232
37 is in communication with the conduit 249 connected to the output port of the differential pressure detection valve 250, the intake cut valve 232
When the upstream pressure, that is, the supercharging pressure P2 on the secondary side approaches the supercharging pressure P1 on the primary side, the differential pressure P1-P2 disappears, and further, when the differential pressure P2-PL becomes larger than a predetermined value, the actuator 233 Atmospheric air is introduced into the air, and the intake cut valve 232 is opened. Also, the three-way valve 238 is OF
When the conduit 237 on the actuator 233 side is connected to the conduit 247 connected to the negative pressure tank 248 at F, negative pressure is supplied to the actuator 233,
Intake cut valve 232 is closed.

On the other hand, when the exhaust cut valve 22'3 control three-way valve 240 is OFF, the exhaust cut valve 223 operating actuator 231 connects to the conduit 239 that connects to the pressure chamber.
When connected to the conduit 252 on the negative pressure tank 248 side,
The actuator 231 is closed by supplying negative pressure.

Further, when the three-way valve 240 is turned on and the conduit 239 on the output side is released to the atmosphere, the exhaust cut valve 223 is opened and supercharging by the secondary turbo supercharger 206 is performed.

The intake relief valve 235 is activated when the three-way valve 243 for controlling the intake relief valve 235 is OFF and the conduit 242 connected to the pressure chamber of the actuator 241 for operating the intake relief valve 235 is communicated with the negative pressure tank 248 side. opens by supplying negative pressure to the
When the three-way valve 243 is turned on and the conduit 242 connected to the pressure chamber of the actuator 241 is released to the atmosphere, it is closed.

In addition, the actuator 2 for operating the waste gate valve 227
26 is a three-way valve 245 for controlling the waste gate valve 227
When the three-way valve 245 is turned on, it communicates with the downstream side of the primary side blower 211 via the conduits 254 and 236, and when the three-way valve 245 is turned off, it is released to the atmosphere.

In this embodiment, hysteresis is provided in the opening and closing operations of the exhaust cut valve 223, the intake cut valve 232, and the intake relief valve 235, as will be described later. In addition, in order to prevent intake air from flowing backward into the secondary floor when the exhaust cut valve 223 closes and the intake cut valve 232 remains open during the transition from the high intake air amount area to the low intake air amount area, this area is The intake cut valve 232 is forcibly closed after a predetermined time (for example, 2 seconds) has elapsed starting from the time when the exhaust cut valve 223 is closed.

FIG. 3 shows an intake cut valve 232, an exhaust cut valve 223,
It is a control map showing the opening/closing control of the intake relief valve 235 and the waste gate valve 227 together with the opening/closing control of the exhaust leak valve 230. This map is stored in the control unit 246, and based on this map, the four electromagnetic solenoid type three-way valves 238, 240, 243, 2
45 controls are performed.

When transitioning from a low intake air amount region to a high intake air amount region, the intake relief valve 235 is open in a region where the engine speed R is low or the intake air amount Q is small.
The opening of the exhaust leak valve 230 causes the secondary turbocharger 206 to rotate 1,000 revolutions. Then, when the engine speed reaches R2 or the intake air amount reaches the line Q2, the solenoid type three-way valve 243 for controlling the intake relief valve 235 is turned on and the intake relief valve 235 is closed.

When the Q4-R4 line is reached, the solenoid type three-way valve 240 for controlling the exhaust cut valve 223 is turned ON and the exhaust cut valve 223 is opened, and then the Q6-R6 line is reached, and the solenoid type three-way valve 240 for controlling the exhaust cut valve 223 is turned on. When the solenoid type three-way valve 238 is turned on and the intake cut valve 232 is opened, supercharging by the secondary turbo supercharger 206 starts.

In other words, the engine enters the supercharging region using both the primary and secondary superchargers at the Q6-R6 line.

That is, since the intake relief valve 235 closes between the time when the exhaust leakage valve 230 opens and the time when the exhaust cut valve 223 opens, the intake relief valve 235 remains open for a predetermined period after the exhaust leakage valve 230 opens. 235
Therefore, the function of preventing the blower 213 from becoming high temperature is ensured. Moreover, since the intake relief valve 235 closes early from the pre-rotation of the secondary turbocharger before the exhaust cut valve 223 opens, the rotation and pressure of the secondary turbocharger 206 increase, causing the exhaust cut valve 223 to close. When opened, supercharging pressure quickly rises from the secondary side blower 213, eliminating drop in torque, reducing torque shock and increasing acceleration response.

Furthermore, the intake relief valve 23 during the period after the exhaust leak valve 230 opens until the exhaust cut valve 223 opens.
The closing timing of No. 5 is set earlier as the shift position is lower. Therefore, even when shifting to a low speed gear where the engine speed increases quickly, the time for closing the intake relief valve 235 when the secondary turbocharger 206 rotates is sufficiently secured, and the secondary turbocharger 206
The rotation and pressure of the secondary blower 207 increase sufficiently, the boost pressure from the secondary blower 207 rises quickly, the torque does not drop, the torque shock is reduced, and the acceleration response is enhanced.

Note that the actuator 23 that drives the intake shutoff valve 232
3 is not only controlled by the operation of the solenoid 238, but also because atmospheric pressure, which is the pressure source that opens the intake cut valve 232, is supplied via the differential pressure detection valve 250, the actual operation of the intake cut valve 232 is The opening operation will be delayed relative to the operation of the solenoid 238. Therefore, the above Q6 and R6 lines for turning the intake cut valve 232 control solenoid 238 from OFF to ON are set in consideration of the delay caused by the differential pressure detection valve 250, and as a result, the Q6R6 line is used to control the exhaust cut valve 223. Solenoid 240 is OFF
It is assumed that the line is close to the line of Q4 and R4, which are turned ON. Further, these Q6, R6 and Q4, R4 can also be made to match.

Conversely, when transitioning from a high intake air amount region to a low intake air amount region, each solenoid type three-way valve 238, 240, 243 that controls the intake cut valve 232, the exhaust cut valve 223, and the intake relief valve 235 has hysteresis. Third
Q5-R5 and Q3-R3, respectively, as shown by broken lines in the figure.
, Ql-Rl. In other words, when transitioning from a high intake air amount area to a low intake air amount area, when the line Q3, R3 is reached, the exhaust cut valve 2
The intake cut valve 232 is closed when the closing control of 23 is performed, and when the transition to the low intake air amount region reaches the line Q5 and R5, the intake cut valve 232 is closed.
The intake relief valve 23 is closed after a delay.
5 opening control is performed.

In this way, by closing the intake cut valve 232 later than the exhaust cut valve 223, surging is prevented from occurring when transitioning to the low intake air amount region.

In addition, in this embodiment, the line that turns on and off the solenoid type three-way valve 245 for controlling the waste gate valve 227 is the line that turns on and off the solenoid type three-way valve 245 for controlling the waste gate valve 227.
, Q4R4, and Q3-R3, which are OFF lines.

In addition, in FIG. 3, the bent portions of each of the above lines are on the so-called no-load line or load-load line.

Therefore, in the above embodiment, when the engine is in a lower intake air amount region than line Q6-R6, the introduction of exhaust gas to the secondary turbo supercharger 206 is stopped, so only the secondary turbo supercharger 204 is operated. When activated, high boost pressure can be obtained quickly. On the other hand, when the engine is in a higher intake air amount region than the above line Q6-R6, both the primary turbo supercharger 204 and the secondary turbo supercharger 206 operate to ensure the intake flow rate and maintain appropriate supercharging pressure. You will get it.

Figure 4 shows the relationship between the solenoid operating state of each valve and the transition of the operating state (the left side of the horizontal axis is the low intake air amount region, and the right side is the high intake air amount region) based on the characteristic diagram in Figure 3 above. This is what I saw. As can be seen from this figure, the hysteresis of the opening/closing operation of the exhaust cut valve 223 is completely included in the hysteresis of the opening/closing operation of the intake cut valve 232. Note that even if the intake cut valve 232 control solenoid 238 is turned on at Q6 and R6, the actual opening operation of the intake cut valve 232 is delayed due to the action of the differential pressure detection valve 250, as shown by the broken line in the figure. Therefore, this Q6. As described above, R6 is a line close to or the same line as Q4 and R4 for controlling the opening of the exhaust cut valve 223. On the other hand, the intake cut valve 23
The closing operation of No. 2 does not involve the above-mentioned delay with respect to the operation of the solenoid 238, so the setting line Q
5, R5 must satisfy Q5<Q3, R5<R3.

Next, control of each valve based on the characteristics shown in FIG. 3 will be explained using a control circuit shown in FIG. 5. The intake relief valve operating solenoid 243 is connected to the first comparison circuit 11 shown at the top of the figure.
1 and the output of the second comparison circuit 112 shown below it are controlled by the output of the first OR circuit 121 which is manually operated. Here, the first comparison circuit 111 compares the intake air ffiQ, which is the detection signal of the air flow meter 221, with the output value of the first addition circuit 131, which is a reference value. Then, the first addition circuit 131
The setting value Q1 corresponding to the Q1 line in the figure is input, and the value Q' 1 for this Q1 (however, Q+
+Q' + -Qz) is input through the l-th gate 141, and when the first gate 141 is opened, the first comparison circuit uses Q+ +Q'1-Q2 as a reference value. 111 and also the first gate 14
When Q1 is closed, Q1 is output to the first comparison circuit 111 as a reference value. And this first gate 14
1 is opened and closed by the output of the first OR circuit 121.

The second comparison circuit 112 compares the engine rotation speed R detected by the engine rotation speed sensor with the output value of the second addition circuit 132, which is a reference value. The second adder circuit 132 has a setting value R1 corresponding to the R1 line in FIG. The second gate 142 is configured to be manually operated via the gate 142, and the second gate 142 has a force {R when opened, 10R',
−． It outputs R2 as a reference value to the second comparator circuit 112, and when the second gate 142 is closed, R1
is output to the second comparison circuit 112 as a reference value. Second
The gate 142 is also opened and closed by the output of the first OR circuit 121.

The first and second comparison circuits 111 and 112 convert the detected intake air ffiQ and engine rotation speed R into a first
and the respective reference values, which are the outputs of the second adder circuit, and turn ON when Q or R exceeds the reference value.
A signal is output to the intake relief valve operating solenoid 243 (when turned ON, the intake relief valve 235 is closed). First and second games 1141, . 142 is the first OR circuit 1
It is closed when the output signal 21 is ON, and is opened when the OR circuit signal is OFF. Therefore, at the time of transition from the low intake air amount area to the high intake air amount area, the output signal of the first OR circuit 121 is OFF, so each gate 14
1,142 are opened and the first and second comparison circuits 111.
112, Q2 and R2 are entered manually as reference values. Therefore, when the line 021R2 in FIG. 3 is reached, an ON signal is issued and the intake relief valve 235 is opened. Also, this ON signal causes the first and second gates 141, 1
42 is closed, so that the radical $ values of Q and R become Ql and Rl, respectively. In other words, the line is set with hysteresis corresponding to Q'1 and R'l in preparation for a transition in the opposite direction.

The exhaust cut valve actuation solenoid 240 is also controlled by a similar control circuit. In other words, the intake air ffiQ
A third comparison circuit 113 is provided for the engine rotation speed R, and a fourth comparison circuit 114 is provided for the engine rotation speed R, and the outputs of these comparison circuits 113 and 114 are provided to the second OR circuit 12.
2 to the solenoid 240. Similarly, a third addition circuit 133 is provided for the third comparison circuit 113, and a fourth addition circuit 134 is provided for the fourth comparison circuit 114. The set value Q3 is input to the third adder circuit 133, and Q'3 (Q3+Q'3=Q4) is also input via the third gate 143. Similarly, the fourth addition circuit 134 has a set value R
3 and R′3 (where R
3 +R' 3 =R4) is manually performed. Similarly, the fourth
The adder circuit 134 contains the set value R3 and the fourth gate 1.
R'3 via 44 (where R3 +R' 3 =
R+) is manually operated. This circuit is connected to the first and second circuits described above.
It operates in the same way as the comparison circuit, and as a result, the exhaust cut valve 223 is opened based on the Q4 and R4 lines in Figure 3 when transitioning to the high intake air amount area, and when transitioning to the low intake air amount area. When transitioning to Q3. The valve 223 is operated to close by the R3 line. Furthermore, the wastegate valve actuation solenoid 245 is also simultaneously controlled by the control signal output to the exhaust cut valve actuation solenoid 240.

For the intake cut valve operating solenoid 238, the fifth
and the outputs of the sixth comparator circuits 115 and 116 are connected to the third O
A similar control circuit is provided which feeds through R circuit 123. This control circuit includes each comparison circuit 115
, 116, the fifth and sixth adder circuits 135, 13
6, and also includes fifth and sixth gates 145, 146 for each adder circuit 135, 136. The basic operation is the same as the circuit for each valve described above. In other words, when transitioning to the high intake air amount area, Q61R6
The intake cut valve opening control is performed by the lines Qs and Rs, and the intake cut valve closing control is performed by the lines Qs and Rs when transitioning to the low intake air amount region. Here, Q6 and R6 are similarly Qs +Q' s =Q6, R5 +R' s-R
It is set in the form of s.

However, in the case of this intake cut valve control circuit, a seventh gate 147 is connected to the output side of the third OR circuit 123, and a control signal is sent to the solenoid 238 via this gate 147.

and the second OR circuit 12 for operating the exhaust cut valve.
A timer 150 is provided that starts counting up from when the output of 2 changes from ON to OFF.
A seventh comparison circuit 117 is provided that issues an ON signal when the count value of this timer 150 exceeds a set value (for example, a value corresponding to 2 seconds), and the ON signal is output from this seventh comparison circuit 117. At this time, the seventh gate 147 is closed to forcibly close the intake cut valve 232, and at the same time, the reference values of Q and R are changed to Q6 and Ra, and the timer 150 is reset. . Once the seventh gate 147 closes, the output of the seventh comparison circuit 117 turns OFF, but since the reference value, which is the switching line, has been changed to Qs and Rs as described above, The intake cut valve operating solenoid 238 is maintained in a closed operating state. This prevents surging from occurring due to the intake cut valve solenoid 240 remaining in the ON state for a long time while the exhaust cut valve solenoid 238 is in the OFF state during the transition to the low intake air amount region.

Further, the set value Q1 manually input to the adder circuit 131 and the set value R1 input to the adder circuit 132 are each corrected by correction circuits 161 and 162. The correction values of the correction circuits 161 and 162 change according to the output signal of the shift sensor 253. That is, the lower the shift position, the lower the set values Ql and R are corrected.

In the above circuit, the parts other than the correction circuits 161 and 162 allow the time between the opening of the exhaust leak valve 230 and the opening of the exhaust cut valve 223 at the time of transition from the low intake air amount region to the high intake air amount region. It constitutes a control means 301 that closes the intake relief valve 235. In addition, the correction circuit 16
1.162 receives the output of the shift sensor (shift position detection means) 253, and the lower the shift position, the closer the intake relief valve 235 closes between when the exhaust leak valve 230 opens and when the exhaust cut valve 223 opens. A correction means 302 is configured to correct the control means 301 so that the speed becomes faster.

Note that the primary side supercharger does not have to be an exhaust turbo type, and may be a mechanical supercharger. Moreover, there may be a plurality of primary side superchargers and a plurality of secondary turbo superchargers.

Furthermore, it does not matter whether the transmission is a manual type or an automatic type.

Further, although the above embodiments have been described with respect to a rotary piston engine, the present invention is not limited to this, and the present invention can also be applied to intake control devices of other types of supercharged engines, such as reciprocating engines. I can do it.

(Effects of the Invention) As explained above, according to the intake air control device for a supercharged engine of the present invention, when the transition from the low intake air amount region to the high intake air amount region is made, the exhaust leakage valve is opened. The intake relief valve is closed before the exhaust cut valve opens, and the lower the shift position, the earlier the intake relief valve close timing between the opening of the exhaust leakage valve and the opening of the exhaust cut valve is corrected. The intake relief valve is opened for a predetermined period of time after the exhaust leakage valve opens, and while the intake relief valve maintains the function of preventing the blower from becoming too hot, the secondary turbo supercharger is released when the exhaust cut valve opens regardless of the shift position. It is possible to build up boost pressure quickly, eliminate torque drop, reduce torque shock, and improve acceleration response.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the present invention, in which Fig. 1 is a general schematic diagram, Fig. 2 is a sectional view of the differential pressure detection valve, Fig. 3 is a control characteristic diagram, and Fig. 4 is an explanatory diagram of the operating state of the device. , FIG. 5 shows the control circuit. 202... Exhaust passage 203... Exhaust passage 204... Primary turbocharger 205... Turbine 206... Secondary turbocharger 207... Turbine 209... Intake passage 210... Branch passage 211... Blower 212... Branch passage 213... Proar 223... Exhaust cut valve 228... Exhaust leak passage 230... Exhaust leak valve 234... Intake relief passage 235... Intake relief valve 253...Shift sensor (shift position detection means) 30
1... Control means 302... Correction means 2 Fig. 4 Fig. 5

Claims (1)

[Claims] (1) A plurality of superchargers including an exhaust turbo supercharger are arranged in parallel in the intake passage, and at least one of the exhaust turbo superchargers is designated as a secondary turbo supercharger and is dedicated to the secondary turbo supercharger. In a supercharged engine that is equipped with an exhaust cut valve in the exhaust passage of the engine, and is configured to open the exhaust cut valve and operate the secondary turbo supercharger only in the high intake air amount region of the engine, the above exhaust cut valve can be bypassed. The exhaust leak passage provided in the exhaust passage, the exhaust leak valve provided in the exhaust leak passage and which opens when transitioning from the low intake air amount area to the high intake air amount area, and the blower of the secondary turbo supercharger are bypassed. an intake relief passage provided in the intake passage dedicated to the secondary turbo supercharger, an intake relief valve provided in the intake relief passage that opens when transitioning from a low intake air amount area to a high intake air amount area; A control means that closes the intake relief valve between the time when the exhaust leakage valve opens and the time when the exhaust cut valve opens when transitioning from the intake air amount region to the high intake air amount region, and a shift position detector that detects the shift position of the transmission. and correcting the control means based on the output of the shift position detection means so that the lower the shift position, the earlier the intake relief valve closes between when the exhaust leak valve opens and when the exhaust cut valve opens. An intake air control device for a supercharged engine, characterized in that it is provided with a correction means for.