JPH04101012A - Control structure during acceleration for automobile control type exhaust device - Google Patents

Abstract

PURPOSE:To fully exhibit the engine output efficiency by forcedly opening a control valve to operate when a signal is outputted from a kickdown switch in the case of opening and operating a control valve to lower exhaust pressure when engine speed and supercharging pressure become a specified value or more. CONSTITUTION:One end parts of exhaust gas pipes 6,7 on both the rear sides partially kept communication with one side of a pre-muffler 5 communicate respectively with one side parts of a first main muffler 8 and a second main muffler 9. A control valve 10 is mounted at a position (l) length down the pre-muffler 5 in the halfway part of the second rear side exhaust pipe 7. An actuator 14 is linked to the control valve 10, and operation of the actuator 14 is controlled by a controller 15. In this case, the control valve 10 is opened in response to the output signal from a kickdown switch 18 outputting a down- shift signal for shifting down gears of transmission in the controller 15.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention controls the opening and closing of a control valve installed in the exhaust system of the engine, thereby adjusting the output characteristics of the engine and the silencing characteristics of the exhaust system. This invention relates to a controlled exhaust system with variable settings.

[Prior Art] Conventionally, exhaust systems used in automobiles include, for example,
The method disclosed in Japanese Utility Model Application Publication No. 183012/1983 has been proposed. This exhaust system has two tail pipes protruding from the rear end of the muffler that guide exhaust scum to the outside, and one of the tail pipes is provided with a control valve.

The control valve is driven to open and close based on an output signal from the controller 22, and the controller 22, when priority is given to silencing, closes the control valve and closes the one tail pipe. is closed, and when output is prioritized, the control valve is opened to open the one tail pipe.

Therefore, when priority is given to silencing, the other tail pipe,
In other words, exhaust gas is discharged through only one tailpipe, which increases exhaust resistance and improves noise reduction performance. Furthermore, when the output is prioritized, exhaust gas is discharged through the two tail pipes, thereby reducing exhaust resistance and increasing the output efficiency of the engine.

However, in such conventional exhaust systems, the tail pipe is closed by the control valve, and the silencing effect relies solely on the increased exhaust resistance, which naturally limits the silencing performance. However, it was not possible to obtain the desired sound silencing effect.

For this reason, the inventor of the present invention has improved the silencing performance by effectively utilizing the exhaust passage closed by the control valve as a resonator when the control valve is closed, instead of simply relying on an increase in exhaust resistance. A controlled exhaust system has been proposed (Utility Application No. 2-10811).

In this control type exhaust system, when the engine speed and boost pressure exceed the set values (for example, set speed - 2.50 Orpm, set boost pressure = 50 mmHg), the vehicle accelerates. It is assumed that the vehicle is traveling, and at this time the control valve is opened to reduce exhaust resistance and increase the output efficiency of the engine. In other cases, the control valve is maintained in a closed state, and the noise reduction performance is improved not only by increasing the exhaust resistance as described above, but also by effectively using the exhaust passage as a resonator.

[Problem to be solved by the invention] In this way, the controlled exhaust system is configured to open the control valve when the engine speed and boost pressure reach predetermined values. However, when accelerating by rapidly depressing the accelerator pedal to enter a highway or overtake, for example, even if the accelerator pedal is suddenly depressed, it takes time for the engine speed to reach a predetermined value or higher. Furthermore, since boost pressure changes while following the engine speed with an unavoidable time lag, in order for both engine speed and boost pressure to exceed the predetermined values, it is necessary to press the accelerator further. A time lag occurs from the moment the barrel is stepped on.

Therefore, if the control valve is simply opened when the engine speed and boost pressure reach a predetermined value, it will not be possible to start the sudden acceleration. The control valve may be maintained in a closed state from the time when the accelerator is depressed until the engine speed and boost pressure satisfy the conditions.

For this reason, when performing sudden acceleration, it is not possible to reliably reduce the exhaust pressure from the moment the accelerator pedal is pressed to maximize the engine's output capability, and the engine has excellent output performance. Despite this, there have been cases where it has been impossible to perform accelerated driving that makes full use of this ability.

The present invention has been made in view of the above-mentioned problems, and provides a control type exhaust system for an automobile that maximizes the output performance of the engine in a timely manner when performing sudden acceleration. The purpose is to provide a time control structure.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, a control valve is inserted in the exhaust system of the Ennon, and a detection means for detecting the engine speed and supercharging pressure is provided. When the engine rotation speed and the boost pressure detected by the detection means are equal to or higher than a predetermined value, for example, the engine rotation speed is 2.500 rpm or more and the boost pressure is 50 mmHg or higher,
The controlled exhaust system opens the control valve to lower the exhaust pressure of the exhaust system, and is provided with a kickdown switch that outputs a signal to shift the automatic transmission into gear. Control means are provided for forcing the control valve open in response to the signal from the down switch.

[Operation] In the above configuration, during normal driving with the kickdown switch in the OFF state, if the engine speed is less than 250 rpm or the boost pressure is less than 50 mmHg, the control valve closes, thereby increasing the exhaust pressure. By doing so, the silencing performance can be improved. Also, the engine speed is 2.
When the engine speed reaches 50 rpm or more and the boost pressure reaches 50 mmHg or more, the control valve opens, thereby reducing the exhaust pressure and increasing the output efficiency of the engine.

When a driver performs a driving operation to perform sudden acceleration, the kickdown switch is turned on, and the kickdown switch outputs a downshift signal, which is a signal for shifting the automatic transmission into gear shift. The automatic transmission performs a gear shift town operation.

At the same time, the control means forcibly opens the control valve in response to the soft down signal. Therefore, when the automatic transmission shifts gears and accelerates suddenly, the control valve opens and exhaust pressure decreases, regardless of engine speed or boost pressure, maximizing engine output efficiency. A state is formed in which it can be exerted to the maximum extent possible.

[Example 1] An example of the present invention will be described below with reference to the drawings. That is, the vehicle according to this embodiment is an automobile equipped with an automatic transmission (hereinafter referred to as an A/T vehicle), and as shown in FIG. One end is connected to the front exhaust pipes 2 and 3, and catalysts 4 and 4 are interposed therein, respectively, and the other end is communicated with one side of a bridge muffler 5. One end of a first rear exhaust pipe 6 and a second rear exhaust pipe 7 are connected to the other side of the brim muffler 5, and the rain rear exhaust pipes 6 and 7 are bent and formed to have a symmetrical shape. has been done. In the middle part of the second rear exhaust pipe 7,
A control valve 10 is interposed at a position downstream from the brim muffler 5 by a length a, and the control valve 10 is operated to open or close to open or close the passage of the second rear exhaust pipe 7. It is configured.

The other end portions of the rain rear exhaust pipes 6 and 7 are connected to one side of the first main muffler 8 and the second main muffler 9, respectively, and two main mufflers 8 and 9 are connected to one side of the first main muffler 8 and the second main muffler 9, respectively. A book tail pipe 12, 13 is provided protrudingly. Note that from the front exhaust pipes 2 and 3 to the eleventh second main muffler 8,
9 constitutes the exhaust system 11 in this embodiment.

An actuator 14 is linked to the control valve IO, and the actuator 14 has a circuit configuration so that its operation is controlled by an output signal from a controller 15 serving as a control means. The controller 15 is configured to receive the engine rotation speed R per unit time from a rotation speed sensor 16, which is an engine rotation speed detection means, and output from a boost sensor 17, which is a supercharging pressure detection means. The supercharging pressure P is input.

Further, a kickdown switch 18 is connected to the input port of the controller 15, and as is well known, the kickdown switch 18 is activated when the gear position of an automatic transmission (not shown) is in a high gear position of 2nd gear or higher. , is configured to turn on when the accelerator is suddenly stepped on. When the kick-down switch 18 is turned on, a shift-down signal S is output to shift down the automatic transmission. , is also input to the previous controller 15.

Next, the operation of this embodiment according to the above configuration will be explained according to the control flowchart of the controller 15 shown in FIG. In other words, this flowchart is
The process starts when the engine 1 is started, and first, it is determined whether or not the kickdown switch 18 is turned on (step 101).

If this determination is NO and the kickdown switch 18 is in the OFF state, there is no sudden action by the driver to press the accelerator pedal, that is, an action to start sudden acceleration driving, and normal driving other than sudden acceleration is performed. It means there is. Therefore, in this case, it is first determined whether the engine rotation speed R is 2,500 rpm or more (step 102).

If this determination is No, the engine speed is 2°500.
If the rpm is below, the controller 15 controls the control valve 1
An electric signal is output to the actuator 14 to close the control valve 10, thereby operating the actuator 14 and maintaining the control valve 10 in the closed state (step 105).
).

When the control valve 10 is maintained in the closed state in this way, the second rear exhaust pipe 7 is closed, and the exhaust residue from the engine 1 is allowed to flow from the pre-muffler 5 into the first rear exhaust pipe 6. and is discharged only from the first main muffler 8. Therefore, compared to the case where exhaust gas is discharged from both the first and second rear exhaust pipes 6, 7 and both the first and second main mufflers 8.9, the exhaust resistance increases, thereby achieving a noise reduction effect. be able to.

Further, when the second rear exhaust pipe 7 is closed by the control valve lO at a position with a length Q from the pre-muffler 5, the second rear exhaust pipe 7 is communicated with the pre-muffler 5 and the length Q is
It functions as a branch pipe consisting of. The branch pipe formed by the second rear exhaust pipe 7 having this length Q is:
Based on its length and volume, it acts as a resonator for sounds of a predetermined frequency and muffles the sounds inside the pre-muffler 5.

Therefore, when the control valve 10 is closed, the exhaust system 11 is set to have a silencing characteristic that can significantly reduce exhaust noise not only due to the silencing effect due to the exhaust resistance but also due to the silencing effect due to acting as the resonator. Ru.

In theory, when the control valve 10 is open, the exhaust resistance increases and the output efficiency of the engine 1 decreases, causing the engine 1 to have a suppressed output characteristic. Become.

On the other hand, if the determination in step 102 is YES and the engine speed is 2.50 rpm or more, it is further determined whether the engine boost pressure P is 50 mm)1 g or more (step 103). If this determination is No and the boost pressure P is less than 50 mmHg, the control valve 10 is maintained in the closed state as described above (step 105).
, and the above determination is YES and the supercharging pressure P is 50 mm.
If it is above Hg, the control valve 10 is opened (step 104).

Then, when the control valve 10 is opened in this way,
The second rear exhaust pipe 7 is opened, and the exhaust gas from the engine 1 is passed from the pre-muffler 5 through the first rear exhaust pipe 6 and the second rear exhaust pipe 7 to the first main muffler 8 and the second main muffler. It is discharged from both sides of the muffler 9. Therefore, control valve 1
When the control valve 10 is operated to open, the exhaust resistance is significantly reduced compared to when the control valve 10 is maintained in the closed state.
This increases the output efficiency of the engine 1, and provides output characteristics that fully demonstrate the performance of the engine 1.

On the other hand, if the accelerator pedal is suddenly depressed, for example to enter a highway or overtake, the kickdown switch 18 is turned on and the determination in step +01 is YES.
becomes. At this time, the automatic transmission signal S is input from the automatic transmission signal S to the controller 15, and the automatic transmission signal S is inputted from the automatic transmission signal S to the controller 15.
A gear down operation such as from overdrive to 3rd gear or from 3rd gear to 2nd gear is performed.

At the same time, the controller 15 responds to the /ft town signal S and forcibly opens the control valve 10 regardless of the fft rotation speed R or the boost pressure P (step 104). This makes it possible to lower the exhaust pressure by opening the control valve 10 to maximize the output efficiency of the engine when gearing down and suddenly accelerating in an A/T vehicle. or is formed.

As a result, at the same time as the accelerator pedal is depressed, the exhaust pressure decreases, making it possible to maximize the output performance of the engine 1. This allows sufficient acceleration performance to be ensured, such as when entering a highway. It becomes possible to overtake safely.

In addition, in A/T vehicles equipped with a turbocharger, the first factor is torque converter slip,
Due to the synergistic effect of the second factor, the time lag between boost pressure and build-up, there is a large time lag between when the accelerator pedal is depressed and when acceleration actually occurs, and this time lag causes the driver to feel an acceleration discomfort. occurs.

However, at the same time as the switch 18 is turned on, that is, at the same time as the accelerator pedal is depressed, the control valve l
As the exhaust pressure decreases due to the opening operation, the efficiency of increasing the rotation of the turbocharger increases, and the supercharging pressure also increases with a steep rise characteristic. Therefore, the time lag of the supercharging pressure, which is the second cause of acceleration delay in an A/T vehicle equipped with a turbocharger, can be reduced, thereby making it possible to reduce the discomfort of acceleration.

Moreover, the rotation speed sensor 16 and the boost sensor 17,
Since the kick-down switch 18 and the like are existing members mounted on the vehicle, by effectively utilizing these existing members, it is possible to implement the system at low cost.

In addition, each real value of the engine rotation speed R1 and the supercharging pressure P shown in the above-described flowchart is a negative example, and appropriate values are used in consideration of the performance of the engine 1 and the like.

In addition, as in the embodiment shown in FIG. 3, a first rear exhaust pipe 6 and a second rear exhaust pipe 7 are branched on the downstream side of the catalyst 4, and the rain rear exhaust pipes 6 and 7 are formed separately. Even if the control valve 10 is connected to one main muffler 19 and is inserted into the first rear exhaust pipe 6, the control valve 10 can be controlled in the same manner as in the embodiment described above. It is possible to achieve the following effects.

[Effects of the Invention] As explained above, the present invention provides a controlled exhaust system that opens a control valve to reduce exhaust pressure when the engine speed and boost pressure exceed predetermined values. When a signal is output from Inochi, the control valve is forcibly opened. Therefore, A/T
When rapidly accelerating a car, the exhaust pressure can be lowered by opening a control valve to create a state in which the output efficiency of the engine can be maximized. Therefore, when an A/T vehicle suddenly accelerates, the engine's output performance can be maximized in a timely manner, ensuring sufficient acceleration performance to allow the vehicle to enter the expressway or overtake. This can be done safely.

In addition, the control valve opens at the same time as the cow pull-down switch is turned on, lowering the exhaust pressure, making it possible to make the supercharging pressure have a steep rise characteristic. It is possible to reduce the time lag of the supercharging pressure, which is a cause of acceleration delay in a T-vehicle, and to reduce the sense of discomfort in acceleration caused to the driver due to this.

In addition, the necessary detection means can be implemented effectively at a low cost because members such as kickdown snouts can be effectively used.

[Brief explanation of the drawing]

FIG. 1 is an overall conceptual diagram showing one embodiment of the present invention, FIG. 2 is a flowchart showing control details of the same embodiment, and FIG. 3 is an overall conceptual diagram showing another embodiment of the present invention. be. 1... Engine, 10... Control valve, 11...
Exhaust system, 15.: Controller (control means), 16.
... Rotation speed sensor (engine rotation speed detection means), 17.
...Boost sensor (supercharging pressure detection means), 18...Kinoku down pressure, R...Engine speed, P.
...Supercharging pressure, S.../ftdown signal.

Claims (1)

[Claims] (1) A control valve is inserted in the exhaust system of the engine, and a detection means for detecting engine speed and boost pressure is provided, and the engine speed and boost pressure detected by the detection means are In a controlled exhaust system that opens the control valve to reduce the exhaust pressure in the exhaust system when the pressure exceeds a predetermined value, a kickdown switch is provided that outputs a signal to downshift the automatic transmission. . A control structure during acceleration of a controlled exhaust system for an automobile, characterized in that a control means for forcibly opening the control valve in response to the signal from the kickdown switch is provided.