JPS62126217A - Exhaust gas muffler for car - Google Patents

Abstract

PURPOSE:To reduce the exhaust gas loss in an acceleration and the like and secure the engine output property, by converting the switching point of a switch valve of an exhaust gas muffler to the lower load or lower rotation side when a kick down signal or a power mode signal of an automatic transmission is detected. CONSTITUTION:At a muffler 3 of the exhaust system of an engine 1, is furnished a switch valve 4 to increase the muffler function when it is closed, and to reduce the exhaust gas resistance when it is opened. To a muffler controller 11, signals are input from a kick down switch 7 and a gear change mode converting switch 9 as well as signals from a throttle sensor 8 and a rotation sensor 10. In an ordinary running, the switch valve 4 is opened only when the kick down switch 7 is off at a high speed and in a high load condition, but in an uphill running and the like the switch valve 4 is opened when the mode converting switch 9 is on to convert to the power mode side, or the kick down switch 7 is on, provided that only the lowest value of the rotation exceeds the standard value.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in an exhaust silencing device for an automobile equipped with an automatic transmission.

(Prior art) A silencer is installed in the exhaust system of a car to muffle the exhaust noise.This muffler reduces noise by dissipating the energy of the exhaust gas, and generally increases the muffling effect. The more you try, the more exhaust pressure will inevitably rise.

An increase in exhaust pressure affects the engine's output performance and fuel efficiency as an exhaust loss, so the silencing performance of the muffler must be determined based on the relationship between engine output and noise. However, in recent years, emphasis has been placed on reducing exhaust noise, and as a result, the exhaust pressure increases when accelerating the Ennon, which can reduce acceleration performance, so it is necessary to satisfy both demands at the same time. This is quite difficult.

Therefore, in the past, for example, in Japanese Utility Model Application No. 59-73518 and No. 59-62218, the silencing performance of a silencer was changed according to the engine speed and load, and when driving in urban areas where the engine speed and load are relatively low. A system has been proposed in which the emphasis is placed on silencing performance when the output is high, and the exhaust pressure is reduced even if the silencing performance is somewhat inferior when the output is high.

For example, as shown in FIG.
In addition to the ports 23A and 23B, there is a port 2 in the bulkhead 21.22.
4A, 24B are provided, and switching valves 25A, 25B are provided to open and close these ports 24A, 24B.
The actuator 26 that controls the operation of the silencer 25B opens the switching valves 25A and 25B at high output when the engine speed and load exceed a predetermined value, and the exhaust gas flowing into the muffler main body 20 from the upstream exhaust W27 is parallel outlet 24A,
By flowing to the downstream exhaust pipe 28 through 24B, 25A, and 25B, the increase in exhaust pressure is suppressed and exhaust loss is reduced.In contrast, in the normal operating range of the engine where the rotation speed and load are not so high, the switching valve By closing 25A and 25B, the exhaust energy is sufficiently dissipated in each chamber between the partition walls 21 and 22, thereby improving the silencing performance.

(Problem to be solved by the invention) However, in conventional devices like this, the engine output is maximized when accelerating suddenly or climbing up a slope, as in a car with an automatic transmission. driving pattern,
Even if you try to run as quietly as possible during general driving, the rotation speed and load value at which the switching valve operates are set to the same value without changing, so it is not enough to handle sudden acceleration. There were times when Ennon output could not be extracted.

Generally, automatic transmissions lower the gear position by one gear when the accelerator pedal is pressed all at once, such as during sudden acceleration.
A Kinfuguan mechanism (for example, see Japanese Unexamined Patent Publication No. 52-81469) that enables output operation, and a shift mode switch that allows the driver to change the gear shift point and select between power mode and stun gate mode. (for example, see Japanese Patent Laid-Open No. 157767/1983), and when these mechanisms operate, high output is required.

However, as mentioned above, in the past, regardless of these operations, the rotation speed and load value at which the switching valve is operated are fixed, and when high output is required, for example when accelerating from a start. The ventilation resistance of the muffler remains high during the early stages of acceleration, when the rotational speed does not increase that much, and is switched to the side where the ventilation resistance is low only in the later stages of acceleration, so acceleration performance cannot be improved as expected due to exhaust resistance during the early stages of acceleration. There was a problem like this.

The present invention aims to solve the above-mentioned problem by shifting the switching timing of the switching valve to lower rotation and lower load during high output operation in connection with the Kirafugukun +91 FJ or the transmission mode switching mechanism. do.

(Method #y for solving the problem) That is, the present invention provides a muffler configured such that exhaust resistance can be switched via a switching valve, a means for detecting engine speed and load, and a means for detecting engine speed and load. Or, in an automatic transmission equipped with a control means for switching the switching valve to a low exhaust pressure side when the engine speed and load rise above a predetermined value, and an automatic transmission having a kick mode switching mechanism or a transmission mode switching mechanism, The present invention includes means for detecting the input of the kickdown signal or the power mode signal, and means for changing the switching point of the serious crime switching valve to a low load or low rotation side upon detection.

(Function) Therefore, during normal driving such as when driving in a city, the silencing performance of the silencer is enhanced to enable eIM driving, but during high output driving when a kickdown signal or power mode signal is input, The switching valve that switches the performance of the silencer shifts to a lower rotation speed and lower load compared to normal conditions, so during sudden acceleration, for example, the exhaust resistance caused by the silencer can be reduced from the beginning of acceleration, which improves engine performance. Improvements are peeling off.

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

In Fig. 1, 1 is an engine, 2 is an automatic transmission that automatically changes the output rotation of the engine 1 and transmits it to the driving wheels, and 3 is an exhaust pressure switching type muffler installed in the exhaust system of the engine 1. , 4 is a switching valve for switching the silencer 3, and the switching valve 4
It has a known configuration in which the silencing function increases when it is closed, and the exhaust resistance decreases when it is open.

5 is an accelerator pedal, 7 is a throttle sensor that detects the opening position of the accelerator pedal 5, 8 is a kick-down switch that is activated when the opening position of the accelerator pedal 5 exceeds a predetermined value, and 9 is a transmission mode changeover switch. Upon receiving the signals from both switches 8 and 9, the controller 6 automatically shifts gears 8.
! Controls the second gear shifting operation. In other words, when the kick-down switch 8 is turned on, the gear position is lowered one step to accelerate, and in the power mode when the transmission mode changeover switch 9 is turned on, the gear shift up point is relatively shifted to the high rotation and high load side. Run at high output.

Reference numeral 11 denotes a 77 controller which is a key component of the present invention, and is used to control a solenoid drive circuit 12 that drives the switching valve 4 in response to input signals from the sensors, switches 7, 8, 9, and rotational speed sensor 10. The excitation current is controlled to open and close the switching valve 4 in association with the automatic transmission 2.

FIG. 2 shows a specific circuit configuration of the 77 controller 11, in which the output of the rotation speed sensor 10 is transmitted to the waveform shaping circuit 1.
0A''C, is converted into a voltage value proportional to the frequency by the F/V converter 1OB, and is compared with a comparison reference value corresponding to a predetermined engine rotation speed N2 in the comparison circuit 14. This rotation speed N2 at 15
The comparison circuit 14.15 outputs a high level signal when the rotation speed is higher than the reference value in either case.

Here, the rotational speed N is made to match the maximum throttle rotational speed of the automatic transmission 2 (the engine rotational speed determined by the turbine/pump characteristics of the torque converter when the 111th station is zero and full throttle). For example, 2.degree. 500 rpm, and the rotation speed N2 is the low noise engine switching rotation speed, which is set to, for example, 3,000 rpm.

Note that the comparator circuit 15 has a large hysteresis so that even if the input voltage value instantaneously becomes smaller than the comparison reference value, the output does not change.

On the other hand, the output voltage of the throttle sensor 8 is compared with a comparison reference value corresponding to a predetermined throttle opening degree θ in a comparison circuit 13, and a high-level signal is output when the sensor output is larger than the reference value.

The output of this comparator circuit 13 is inputted via an OVER circuit 16 to an AND circuit 17 into which the output of the comparator circuit 14 is input.

A signal from the speed change mode changeover switch 9 is input to this OFF circuit 16 via the switch processing circuit 9A, and therefore the OFF circuit 16 is activated when the comparison circuit 13 outputs a high level or when the changeover switch 9 is in the power mode. A high level signal is output to the AND circuit 17.

18 is a switch circuit, which normally outputs the output of the AND circuit 17 as it is to the slide/ide drive circuit 12, but when the kick-down switch 7 is turned on, the output of the AND circuit 17 is output to the switch processing circuit 7A.
When the output from the comparator circuit 15 is input to the terminal a, the output of the comparator circuit 15 is switched to be output to the solenoid drive circuit 12.

The system is constructed as described above, and its operation will be explained next.

During normal operation, the kick-down switch 7 is OFF, and the switch circuit 18 in FIG. 2 outputs the input from the terminal C side as it is (no input is from the terminal C side). Therefore, in the standard mode with the shift mode selector switch 9 OFF, as shown in Fig. The output of the circuit 17 is turned on, the switching valve 4 is opened via the solenoid drive circuit 12, and the silencer 3 is switched to reduce the exhaust resistance. However, at other times, in order to reduce exhaust noise, the drive circuit 12 is kept OFF, the switching valve 4 is closed, and the muffler 3 is kept in a state with a high silencing function.

On the other hand, when the driver turns on the gear change mode changeover switch 9 and the automatic transmission 2 is switched to the power mode when climbing a mountain road etc., regardless of the output of the throttle sensor 8, the overclocking circuit 16 becomes high level, and the AND circuit 17 outputs an output to the solenoid drive circuit 12 via the switch circuit 18 to open the switching valve 4 and eliminate the exhaust resistance of the muffler 3 as long as the engine speed reaches N2 or higher. and ensure engine output performance.

On the other hand, when a car accelerates suddenly, such as when entering a highway, the highest output is required from the Ennon, and in such cases the kickdown switch 7 is activated as the accelerator pedal is depressed. The switch circuit 18 is turned on, and the switch circuit 18 outputs the input from the terminal C to the solenoid drive circuit 12 as it is (in this case, no input is received from the terminal C side).

Therefore, as long as the rotation speed becomes higher than N1, which is the comparison base value, in the comparison circuit 15, the switching valve 4
is opened to reduce exhaust resistance. In this case, the basic value N1 is lower than N2, and therefore, during sudden acceleration when the kickdown switch 7 is turned on, the ventilation resistance of the silencer 3 is further reduced from the low rotation range. Good acceleration performance can be obtained from the initial stage of acceleration. In this case, since the hysteresis caused by the comparator circuit 15 is large, even if the rotational speed momentarily drops by N due to shift amplification during acceleration, the switching valve 4 remains unchanged.
The valve is kept open.

(Effects of the Invention) As described above, according to the present invention, the operating point of the silencer switching valve is changed in relation to the kickdown mechanism and the transmission mode switching mechanism. In driving conditions where maximum engine output is desired, such as this, exhaust loss is minimized to ensure engine performance, and when driving around town, the performance of the muffler is increased to ensure quiet driving. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 2 is a 7
3 is an explanatory diagram showing the operation mode, and FIG. 4 is an explanatory diagram of the configuration of a conventional silencer. 1... Engine, 2... Automatic transmission, 3... Silencer, 4... Selector valve, 5... Accelerator pedal, 6...
・Controller, 7...Kickdown switch, 8・
. . . Throttle sensor, 9 . . . Shift mode changeover switch, 10 .
15...Comparison circuit, 16...Owa circuit, 17...
AND circuit, 18... switch circuit. Patent applicant: Japan Radiator Co., Ltd., as follows: 1. ′・−
Figure 1 11 (Muffler controller) Figure 3

Claims (1)

[Claims] a silencer configured to be able to switch exhaust resistance via a switching valve; means for detecting engine speed and load; In an automobile equipped with a control means for switching to a low exhaust pressure side, and an automatic transmission having a kickdown mechanism or a transmission mode switching mechanism, means for detecting the input of the kickdown signal or the power mode signal; An exhaust muffling device for an automobile, comprising means for changing a switching point of a switching valve to a low load or low rotation side.