JPH01219319A - Supercharging pressure control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent damage to the engine by controlling the pressure acting on a pressure chamber of an actuator of a waste gate valve through a control valve so that the supercharging pressure converges on a preset value. CONSTITUTION:A waste gate valve 38 is provided in a bypass passage 32 bypassing an exhaust gas turbine 8 of a supercharger 4. The pressure on the downstream side of a compressor 6 of the supercharger 4 is adapted to act through a pressure-conducting passage 56 on a pressure chamber 46 of an actuator of the waste gate valve 38. A pressure control valve 60 is provided in the pressure-conducting passage 56 to control the acting pressure so that the supercharging pressure converges on a preset value. Excessive supercharging pressure can be prevented when the temperature is low, and engine damage can thus be avoided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a boost pressure control device for an internal combustion engine, and is used to prevent boost pressure (intake air amount) from becoming unnecessarily high, especially at low temperatures. At the same time, the capacity of intake and exhaust system components including fuel injection valves and air flow meters can be reduced (and the cost can be reduced).
Moreover, the present invention relates to a boost pressure control system for an internal combustion engine that can easily determine the capacity and specifications of intake and exhaust system components.

[Conventional technology]

In a supercharger that pressure-feeds intake air to an internal combustion engine in order to improve the output of the engine, if the supercharging pressure (amount of intake air) increases too much, it will cause damage to the supercharger and the internal combustion engine. Conventionally, when the boost pressure reaches a set value determined by outside air temperature, engine speed, etc., a portion of the intake air downstream of the turbocharger compressor is relieved upstream to adjust the set value. There are systems that control the temperature so that it does not exceed a set value, and systems that bypass a part of the exhaust gas on the upstream side of the exhaust turbine of the supercharger to the downstream side, as shown in FIG. 6, so as not to exceed a set value. That is, in FIG. 6, 2 is an internal combustion engine, 4 is a supercharger, 10 is an intake passage, and 12 is an exhaust passage. The supercharger 4 rotates a compressor 6 provided facing the intake passage 12 by an exhaust turbine 8 provided facing the exhaust passage 12, and pumps air taken in from the air cleaner 16. From the compressor 6 to the combustion chamber 2 of the internal combustion engine 2
An intake throttle valve 18 is provided in the intake passage 10 leading to the intake passage 6. Note that 14 is an air flow meter for detecting the amount of air, 20 is a surge tank, and 30 is a fuel injection valve.

A bypass passage 32 is provided that bypasses the exhaust turbine 8 of the supercharger 4 of the internal combustion engine 2 and communicates with the exhaust passage 12. The bypass passage 32 has an opening end at an inlet 34 provided in the first exhaust passage 12-1 on the upstream side of the exhaust turbine 8, and
An open end is provided at the outlet 36 provided in the second exhaust passage 12-2 on the downstream side of the exhaust turbine 8. This bypass passage 12 is provided with a swing type wastegate valve 38 that opens and closes the inlet 34.

Wastegate valve 38 is actuated by actuator 40 . The actuator 40 has a pressure chamber 46 and an atmospheric chamber 4 defined by a diaphragm 44 in the main body 42.
8. One end side of a loft 50 is connected to the diaphragm 44, and the other end side of this rod 50 is connected to a rotating lever 52 of the waste gate valve 38. The pressure chamber 46 includes a second pressure chamber on the downstream side of the compressor 6.
A pressure guiding passage 56 is provided in the intake passage 10-1 with an open end and an open end. Further, in the atmospheric chamber 48 defined by the diaphragm 44, a spring 54 is provided to bias the pressure chamber 46 in the direction of contraction.

As a result, the actuator 40 is activated by the actuating rod 5 due to the supercharging pressure acting on the pressure chamber 46 and the biasing force of the spring.
By pushing and retiring the operating rod 50, the waste gate valve 38 is opened and closed to bypass a portion of the exhaust gas, thereby controlling the supercharging pressure to a set value.

In addition, as a boost pressure control device for such an internal combustion engine,
For example, it is disclosed in Japanese Patent Publication No. 60-5773.

What is described in this bulletin is a supercharging pressure adjustment device that adjusts the boost pressure downstream of the supercharger, and a supercharging pressure adjustment device that adjusts the boost pressure downstream of the supercharger. By controlling the supercharging pressure adjustment device so that it remains constant and gradually decreases as the engine speed increases in the engine's high speed range, it is possible to improve the This prevents the supercharging pressure from becoming abnormally high even during low- to medium-speed rotation and high-load operation, thereby preventing knocking.

[Problem that the invention seeks to solve]

By the way, in the boost pressure control device, as shown in Fig. 7, the fully open air amount is set (S line) when the outside temperature is 25 degrees Celsius, which is approximately normal temperature, and the boost pressure is adjusted according to the engine speed. (intake air amount) has been determined. In other words, in Fig. 7, when the outside temperature is 25°C, the boost pressure rises above the S line when accelerating from M, but this boost pressure goes back to the S line immediately after exceeding the S line. This prevents boost pressure from increasing.

However, as shown in Figure 8, when the outside air temperature is low (-20°C), the air density increases
With the spring load of the spring 54 of the actuator 40 shown in FIG. 6 set by the line, the amount of exhaust gas discharged from the bypass passage 32 is almost the same as when the outside air temperature is set at 25°C, so the boost pressure (intake air amount) There was a problem that the internal combustion engine would become unnecessarily high, and in the worst case, it would damage the internal combustion engine, so there was a desire for an improvement.

In addition, considering the possibility that the amount of intake air increases, that is, the boost pressure increases, at low temperatures, etc., it is necessary to increase the capacity of intake and exhaust system components including fuel injection valves and air flow meters, which is expensive. In addition, there was an inconvenience that it became difficult to determine the capacity and specifications of the intake and exhaust system components.

[Purpose of the invention]

Therefore, the purpose of this invention is to eliminate the above-mentioned disadvantages (
A pressure control valve is provided to adjust the pressure in the intake passage downstream of the compressor that acts on the pressure chamber of the actuator that operates the wastegate valve, and the supercharging pressure supplied to the internal combustion engine is maintained at the set value regardless of the intake air temperature state. By controlling the operation so as to converge, it is possible to prevent boost pressure from increasing unnecessarily even at low temperatures, thereby avoiding damage to the internal combustion engine, as well as improving the performance of intake and exhaust components including fuel injection valves and air flow meters. An object of the present invention is to realize a boost pressure control device for an internal combustion engine that has a small capacity, is inexpensive, and can easily determine the capacity and specifications of intake and exhaust system components.

[Means for solving problems]

In order to achieve this object, the present invention provides an internal combustion engine turbocharger that controls the boost pressure supplied to the internal combustion engine using a wastegate valve provided in a bypass passage that bypasses the exhaust turbine of the turbocharger and communicates with the exhaust passage. The supply pressure control device includes an actuator that operates the wastegate valve,
A pressure control valve is provided to adjust the pressure in the intake passage downstream of the compressor of the supercharger that acts on the pressure chamber of the actuator, and the pressure control valve is supplied to the internal combustion engine regardless of the temperature state of the intake air to the internal combustion engine. The present invention is characterized in that a control means is provided for controlling the operation so that the supercharging pressure is converged to a set value.

[Effect]

According to the configuration of the present invention, when the air density is high at low temperatures, etc., the control means is configured to apply pressure to the pressure chamber of the actuator so that the wastegate valve opens the bypass passage regardless of the intake air temperature state. Controls the operation of the pressure control valve. As a result, the boost pressure is lowered, and damage to the internal combustion engine can be avoided. In addition, the capacity of intake and exhaust valve components including fuel injection valves and air flow meters does not need to take into account the increase in supercharging pressure at low temperatures, so the capacity of intake and exhaust system components can be reduced. It becomes easy to determine the capacity and specifications of intake and exhaust system components.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

1 to 5 show embodiments of this invention. In the figure, 2 is an internal combustion engine, 4 is a supercharger composed of a compressor 6 and an exhaust turbine 8, IO is an intake passage,
12 is an exhaust passage. An air cleaner 16 is provided in the first intake passage 10-1 on the upstream side of the compressor 6 of the supercharger 4 via an air flow meter 14.
A surge tank 20 is provided in the second intake passage 10-2 on the downstream side via an intake throttle valve 18. The third intake passage 10 - 3 on the downstream side of the surge tank 20 communicates with the intake port 22 . This intake port 22 is connected to the intake valve 2
4 to the combustion chamber 26 of the internal combustion engine 2. Further, this combustion chamber 26 communicates with the first exhaust passage 12-1 via an exhaust valve 28. This first exhaust passage 12-1
An exhaust turbine 8 of the supercharger 4 is provided on the downstream side, and a second exhaust passage 12-2 communicates with the downstream side of the exhaust turbine 8.

Further, a fuel injection valve 30 is provided facing the intake port 22.

The first exhaust passage 1 bypasses the exhaust turbine 8 of the supercharger 4.
2-1 and the second exhaust passage 12-2. A bypass passage 32 is provided. The bypass passage 32 has one end connected to an inlet 34 that opens into the first exhaust passage 12-1. , the other end side is connected to an outlet 36 that opens into the second exhaust passage 12-1.
The inlet 34 is opened and closed by a wastegate valve 38. This wastegate valve 38 is connected to the actuator 4
0.

A pressure chamber 46 and an atmospheric chamber 48 are defined in this actuator 40 by a diaphragm 44 within a main body 42 . One end of an actuating rod 50 is connected to one surface of the diaphragm 44, and the other end of the actuating rod 50 is connected to a rotating lever 52 connected to the waste gate valve 38.

Further, the atmospheric chamber 48 of the main body 42 of the actuator 40
A spring 54 is disposed to bias the diaphragm 44 in the direction in which the pressure chamber 46 is contracted.

The pressure chamber 46 of the actuator 40 is opened at the other end of a pressure guiding passage 56, one end of which opens into the second intake passage 10-2 on the downstream side of the supercharger 4.

A pressure control passage 58 is connected to the pressure passage 56 midway through the pressure passage 56, and the other end is open to the pressure passage 56 and the other end communicates with the first intake passage 10-1 on the upstream side of the supercharger 4. There is.

A pressure control valve 60 is provided in the middle of this pressure control passage 58 to adjust the pressure acting on the pressure chamber 46 of the actuator 40 from the pressure guiding passage 56. Further, in the pressure control passage 58, a throttle 61 having a predetermined opening area is provided on the pressure control passage 56 side of the pressure control valve 60 in order to adjust the pressure acting on the pressure control valve 60 from the pressure control passage 56 to a predetermined value. is provided.

A control means 62 is connected to the pressure control valve 60 to control the operation of the pressure control valve 60 so that the boost pressure supplied to the internal combustion engine 2 converges to a set value regardless of the temperature state, for example, the outside air temperature. There is.

This control means 62 includes an air flow meter 14 to detect the amount of intake air, a throttle sensor 64 to detect the opening degree and acceleration state of the intake throttle valve 18, and a surge tank 20 to detect the boost pressure. Pressure sensor 6 installed in
6, and a water temperature sensor 6 that detects the temperature of the cooling water of the internal combustion engine 2.
8, an intake air temperature sensor 70 provided on the first intake road 10-1 near the air cleaner 16 to detect the intake air temperature;
And it is in communication with the fuel injection valve 30.

As shown in FIG. 4, the control means 62 also includes a fully open air amount (A line) at an outside temperature of 25° C. as a set value for boost pressure, and a boost pressure control determination value as a determination value for boost pressure control. The air amount (B line) and the boost pressure control air amount during acceleration (C line) are set as a determination value during acceleration. In other words, Fig. 4 shows the state when the boost pressure is not controlled, and when there is sudden acceleration from the position rOJ, the boost pressure (intake air amount) rises beyond the A line and the B line, but immediately Converged to the A line, and again? If you accelerate slowly from rPJ, the boost pressure slightly exceeds the A line, but soon
converges to the line.

Furthermore, as shown in FIG. 5, the ASBSC line is set in the control means 62 as in the case of FIG. The pressure control air amount (D line) is set. That is, FIG. 5 shows the supercharging pressure control, and during the supercharging pressure control, supercharging is controlled between the A line and 8947.

Next, the operation of this embodiment will be explained based on the flowchart in FIG. 3 and the diagram showing the relationship between engine speed and boost pressure (intake air amount) in FIG. 4.5.

For example, in FIG. 4.5, when the engine suddenly accelerates from position "0", the boost pressure changes as indicated by the broken line X. Then, when the program starts in the control means 62 (step 102), first, the boost pressure (intake air amount) Qa>
The fully open air amount A when the outside temperature is 25° C. is determined (step 104).

If Qa<A and No in this step 104, this judgment state is continued.

On the other hand, if Qa>A and YES in step 104, that is, when the boost pressure exceeds the A line and the B line in FIG.
w>Warm-up Judgment Cooling water temperature T w 1 is judged (step 106). In other words, it is determined whether the internal combustion engine 2 has been warmed up.

In this step 106, 'l' vt > T w
If NO in 1, it is determined that supercharging pressure Qa>supercharging pressure control determination air amount B (step 108). This step 1
If Qa<B and NO in step 08, the process returns to step 104.

Also, in Figure 4.5, when slow acceleration is performed from position rPJ, the supercharging pressure changes as shown by the broken line Y, and after crossing the A line or B line, the supercharging pressure quickly converges to the A line. be done.

If Qa>B and YES in step 108, the pressure control valve 60 (VSV) is closed (step 11O). By closing the pressure control valve 60 in this manner, the pressure acting on the pressure chamber 46 of the actuator 40 is increased, and the operating rod 50 and the rotating lever 52 are
The wastegate valve 38 is moved away from the inlet 34 via the inlet 34 to allow exhaust gas to exit the bypass passage 32 and reduce the boost pressure.

Next, in step 112, it is determined whether the fully open air amount A is when the supercharging pressure Q a <the outside temperature 25° C. This step 1
If Qa>A and No in step 12, the process returns to step 110.

On the other hand, if Qa<A and YES in step 112, the pressure control valve 60 is opened (step 11
4). That is, the pressure control valve 60 opens the pressure control passage 58 and directs a portion of the pressure from the pressure guiding passage 56 to the first intake passage 1.
By flowing to the 0-1 side, the actuator 40
In order to reduce the pressure acting on the pressure chamber 46 and close the inlet 34, the wastegate valve 38 is operated to increase the supercharging pressure. After the pressure control valve 60 is opened in step 114, the process proceeds to step 130, which will be described later.

On the other hand, in step 106, Tw > Twl and Y
In the case of ES, that is, when the internal combustion engine 2 is warmed up, it is determined that intake throttle valve change amount/time ΔTH>acceleration determination intake throttle valve change amount/time ΔTHI (step 116)
. In other words, after warming up, A
The amount of change in the intake throttle valve 18 and the amount of change in intake air within a certain period of time before crossing the line are determined.

In this step 116, ΔTH<ΔTH.

If the answer is No, the supercharging pressure Qa is increased in step 118.
>Determine the air amount B for determining the boost pressure control (step 11)
8).

In this step 118, if Qa<B and No, the process returns to step 116.

On the other hand, if Qa>B in step 118, the process proceeds to step 124, which will be described later, and the pressure control valve 60
to be closed.

If ΔTH>THI and YES in step 116, determine intake air change amount/time ΔQa>acceleration determination intake air change amount/time ΔQ a 1 (step 1
20).

In this step 120, ΔQ a <ΔQa1 and N
If O, the process returns to step 118.

In step 120, ΔQa>ΔQ a 1 and Y
In the case of ES, that is, in the case of sudden acceleration, the supercharging pressure Qa
>Judge the air amount C for control determination during acceleration (step 122
). If Qa<C and NO in step 122, the process returns to step 116.

If Q a > C is YES in the step 122, that is, if the C line is exceeded, the pressure control valve 60 is closed (step 124).

Next, in step 126, the fully open air amount A when boost pressure Qa<outside temperature 25° C. is determined. In other words, it is determined whether the boost pressure has fallen below the A line.

If Qa>A and NO in step 126, the process returns to step 124 and the pressure control valve 60 is closed.

On the other hand, if Qa<A and YES in step 126, the pressure control valve 60 is opened (step 128).
).

Next, in step 130, supercharging pressure Qa>outside temperature 2
Determine the fully open air amount A at 5°C. In other words, intake throttle valve 1
8 is left fully open or decelerated. If Qa<A and No in step 130, the process returns to step 116. In other words, it is determined that the internal combustion engine 2 is decelerating.

If Qa>A and YES in step 130, it is determined whether supercharging pressure Qa>supercharging pressure control air amount (step 132). In this step 132, Q a <
If No in D, the process returns to step 130.

On the other hand, in step 132, Q a > D and Y
In the case of ES, in step 134 the pressure control valve 6
0 and then returns to step 126 above. That is, while the intake throttle valve 18 is fully open, the pressure control valve 62 is repeatedly turned ON and OFF between the A line and the D line, and the pressure acting on the pressure chamber 46 of the actuator 40 is increased or decreased. As a result, the pressure in the pressure guiding passage 56 acting on the pressure chamber 46 of the actuator 40 is adjusted, the operating loft 50 and the rotation lever 52 are operated, and the waste gate valve 38 is operated.
Operate opening and closing.

As a result, it is possible to prevent the supercharging pressure from increasing unnecessarily, and to eliminate the risk of damage to the internal combustion engine 2, especially when the air density is high, such as at low temperatures.

In addition, the capacity of the fuel injection valve 30, which is a component of the intake and exhaust system, can be set small because there is no need to take into account an increase in the amount of intake air at low temperatures, that is, an increase in supercharging pressure. It can be done.

Furthermore, when testing and determining the capacity settings of intake and exhaust system components such as the fuel injection valve 30 and air flow sensor 14,
Since there is no need to take into account the increase in the amount of intake air at low temperatures, it is possible to determine the requirements at room temperature, which simplifies the determination of the capacities and specifications of the intake and exhaust system components, which is advantageous in practice.

In addition, in this embodiment, the intake air amount has been explained as an example of control, but in addition, the output voltage of the pressure sensor, the load data of the control means 62, and the injection time from the control means 62 to the fuel injection valve 30 are also used. It goes without saying that the same control can be performed even if it is replaced with, etc.

Further, according to this embodiment, the maximum boost pressure and the 0N-OFF control air amount of the pressure control valve 60 can be set for each engine speed, and the first operating air amount of the pressure control valve 60 can be set. and the ON-OF I control air amount can be set separately, and furthermore, the operating air amount of the pressure control valve 60 during rapid acceleration and slow acceleration can be set separately.

Furthermore, during sudden acceleration, the operation of the pressure control valve 60 can be delayed to prevent the pressure control valve 60 from operating frequently.

Furthermore, the operating air amount of the pressure control valve 60 before and after warming up is set separately, and the difference in the operating air amount of the pressure control valve 60 after 0N-OFF control is set to 0.5 kg/ aJ or less, which has significant practical effects.

〔Effect of the invention〕

As is clear from the above detailed description, according to the present invention,
A pressure control valve is provided to adjust the pressure in the intake passage downstream of the compressor that acts on the pressure chamber of the actuator that operates the wastegate valve, and the supercharging pressure supplied to the internal combustion engine is maintained at the set value regardless of the intake air temperature state. By providing a control means that controls the operation to converge, it is possible to prevent the supercharging pressure from increasing unnecessarily at low temperatures, thereby avoiding damage to the internal combustion engine, and also to reduce the capacity of the intake and exhaust system components (
This is advantageous in practice because it is inexpensive, and the capacity and specifications of the intake and exhaust system components can be easily determined.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention, FIG. 1 is a schematic diagram of a boost pressure control device, FIG. 2 is an enlarged view of main parts of the boost pressure control device in FIG. 1, and FIG. 3 is a schematic diagram of a boost pressure control device. A flowchart explaining the operation of this embodiment, Fig. 4 is a diagram showing the relationship between engine speed and supercharging pressure (intake air amount) when supercharging pressure is not controlled, and Fig. 5 is a diagram showing the relationship between supercharging pressure (intake air amount) when supercharging pressure is not controlled. FIG. 3 is a diagram showing the relationship between engine speed and boost pressure (intake air amount). Figure 6 is a schematic diagram of a conventional boost pressure control device, Figure 7 is a diagram showing the relationship between engine speed and boost pressure (intake air amount) when the outside air temperature is 25°C, and Figure 8 is the outside air temperature. FIG. 2 is a diagram showing the relationship between engine speed and supercharging pressure (intake air amount) at -20°C. In the figure, 2 is an internal combustion engine, 4 is a supercharger, 10 is an intake passage, 18 is an intake throttle valve, 30 is a fuel injection valve, 32 is a bypass passage, 34 is an inlet, 36 is an outlet, 38 is a wastegate valve, 40 is an actuator, 46 is a pressure chamber, 56
58 is a pressure control passage, 60 is a pressure control valve, 61 is a throttle, 62 is a control means, 60 is a throttle sensor, 66 is a pressure sensor, 68 is a water temperature sensor, and 70
is the intake temperature sensor. Patent applicant: Suzuki Motor Co., Ltd. Agent, Patent attorney Yoshi Saigo
(ytohQl-za”c,) iku meat n rin grain →
Hemokuguchi 1 Turning of grains - Procedural master book 1 issue) April 11, 1985 1, Indication of the case Patent application No. 1983-046412 2, Name of the invention Internal combustion engine supercharging pressure control device 3, Amendment Relationship with the case of a person who does
(208) Suzuki Motor Co., Ltd. Representative Suzuki
4, Agent 101 7n 03-292-4
411 (Representative) Address: Saigo Patent Building (2), 2-8 Kanda Ogawamachi, Chiyoda-ku, Tokyo Figures 4 and 5 of the drawings are amended as shown in the attached sheet. Fig. 1 Fig. 2rM Fig. 3 Fig. 4 Tank Seki rotation teaching → Fig. 5 Kaima rotation] Arrow -

Claims (1)

[Claims] 1. A boost pressure control device for an internal combustion engine that controls boost pressure supplied to the internal combustion engine by a wastegate valve provided in a bypass passage that bypasses an exhaust turbine of a supercharger and communicates with an exhaust passage, wherein the wastegate An actuator for operating the valve is provided, and a pressure control valve is provided for adjusting the pressure in the intake passage on the downstream side of the compressor of the supercharger that is applied to the pressure chamber of the actuator, and the pressure control valve is provided to adjust the pressure in the intake passage downstream of the compressor of the supercharger, regardless of the temperature state of the intake air to the internal combustion engine. A supercharging pressure control device for an internal combustion engine, comprising a control means for controlling the operation of a control valve so that the supercharging pressure supplied to the internal combustion engine converges to a set value.