KR100520352B1 - Muffler for reducing the reverse pressure - Google Patents

Abstract

According to the present invention, an opening and closing blade is installed around the hole of the exhaust gas outlet pipe to control the area where the exhaust gas passes when the engine bouncing occurs in the low speed region, thereby improving noise, and controlling the opening and closing blade and the variable valve in the high speed region to control the back pressure. It relates to a back pressure reducing muffler that can be reduced.

The back pressure reducing muffler of the present invention is divided into a plurality of closed spaces (4, 5, 6) using a plurality of partitions (2, 3), and then through an inflow pipe (7) having holes (7a) formed from the engine. In the muffler which injects exhaust gas and discharges gas using the divert pipe 8 with the variable valve 10 attached thereto and the outflow pipe 9 with the hole 9a formed therein, Variable valve opening and closing part 16 for adjusting the opening and closing degree, opening and closing blade operation part 12 for closing the hole 9a stepwise by moving the opening and closing blade 21, and the rotational speed and throttle opening degree of the vehicle engine And an ECU 11 for measuring the rate and controlling the opening and closing degree of the opening and closing blade 21 of the variable valve 10 and the opening and closing blade operating unit 12 of the variable valve opening and closing portion 16 according to the amount of exhaust gas. It is characterized by.

Description

Muffler for reducing the reverse pressure}

The present invention relates to a back pressure reducing muffler, and more particularly, an opening and closing blade is mounted around a hole of an exhaust gas outlet pipe to control an area in which exhaust gas passes when an engine boom occurs in a low speed region, thereby improving noise, The present invention relates to a back pressure reducing muffler that can reduce the back pressure by controlling the opening and closing blades and the variable valve.

An engine used as a power generating means of a vehicle burns fuel at high temperature and converts the explosive force generated at this time into a rotational motion. The exhaust gas generated by combustion in the engine is collected by the exhaust manifold and then discharged to the outside through the exhaust pipe and the muffler. The muffler is a device for reducing exhaust noise by lowering the temperature and pressure of the exhaust gas discharged from the engine.

1 illustrates a structure of a semi active muffler used in the related art. The muffler manufactures the muffler case 1 from a steel plate of about 1 mm, and divides the interior of the muffler case 1 into a plurality of closed spaces 4, 5, 6 using a plurality of partitions 2, 3. Afterwards, the exhaust gas is introduced from the engine through the exhaust gas inlet pipe 7, and the gas is discharged into the atmosphere by using the diverter pipe 8 and the exhaust gas outlet pipe 9.

In particular, a plurality of holes (7a, 9a) are formed on the surface of the inlet pipe (7) and the outlet pipe (9), one side end of the diverter pipe (8) to maintain a closed state by a spring (not shown) The variable valve 10 is mounted.

The muffler reduces the booming noise of the engine while the exhaust gas is discharged to a plurality of holes 7a formed on the surface of the inlet pipe 7 in a state where the variable valve 10 is closed due to the low exhaust gas discharge rate in the low speed region. Let's do it. The exhaust gas discharged through the hole 7a is discharged through the hole 9a of the outflow pipe 9.

On the other hand, in the high speed region, the exhaust flow rate of the exhaust gas is large, and accordingly the pressure acts largely, so the pressure of the exhaust gas overcomes the elastic force of the spring of the variable valve 10 and the back pressure is reduced as the variable valve 10 is opened. The exhaust gas is discharged through the outflow pipe 9.

The following problems occurred during the conventional muffler tuning. The tuning of the conventional muffler as shown in FIG. 1 adjusts the back pressure using the diameter of the exhaust gas inlet and outlet pipes 7 and 9 and the elastic force of the spring of the variable valve. However, in the case of booming noise in the low speed region, it is possible to improve the booming noise in the low speed region by tuning in the direction of reducing the diameter of the inflow and outflow pipe in order to reduce it. The exhaust gas is not discharged smoothly, which causes an adverse effect of increasing the back pressure. Therefore, unlike the basic purpose of the conventional semi-active muffler, only the back pressure is increased.

The present invention has been made to solve the above problems, an object of the present invention is to install the opening and closing blades around the hole of the exhaust gas outflow pipe to control the area through which the exhaust gas passes when the engine bouncing occurs in the low speed region noise The present invention provides a back pressure reducing muffler that can reduce the back pressure by controlling the opening and closing blades and the variable valve in the high speed region.

Another object of the present invention is to provide a back pressure reducing muffler that can be applied to all vehicles regardless of the vehicle type by changing only the control program without changing the structure of the muffler itself.

In order to achieve the above object, a back pressure reducing muffler of the present invention divides into a plurality of closed spaces by using a plurality of partition walls, and then introduces exhaust gas through an inlet pipe having a hole formed from an engine, and has a variable valve attached thereto. In the muffler for discharging gas by using the outflow pipe formed with the switching pipe and the hole, the variable valve opening and closing portion for adjusting the opening and closing degree of the variable valve, and the opening and closing blade operation for closing the hole in stages by moving the opening and closing blades And an ECU for measuring the rotational speed and the throttle opening ratio of the vehicle engine and controlling the opening and closing degree of the opening and closing blades of the variable valve opening and closing blade operation unit according to the exhaust gas amount according to the exhaust gas amount.

Hereinafter, a back pressure reducing muffler of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a side cross-sectional view showing the structure of the back pressure reducing muffler according to the present invention, a variable valve operated by a control signal from the ECU 11 on the side of a conventional muffler variable valve 10 as shown in FIG. The opening / closing part 16 is provided, and is also used to shield the hole 9a by using the opening / closing blade 21 around the hole 9a of the outflow pipe 9 and is also operated by the control signal of the ECU 11. The opening and closing blade operation unit 12 is installed. The ECU 11 may be configured by using an ECU mounted on a conventional vehicle or by using another one-chip microcomputer.

Looking at the structure of the variable valve opening and closing portion 16, the operating rod 17 and the one end is connected to the outer surface of the variable valve 10, the spring 19 is connected to the other end of the operation rod 17 and The other end of the spring 19 is connected to a connection terminal 20 to which a wire to which a control signal is transmitted from the ECU 11 is connected, and is installed on an outer circumferential surface of the operation rod 17 and the connection terminal 20. It includes a solenoid coil 18 for generating a magnetic force by the current (pulse-type control signal) supplied through the wire connected with. Although not shown in detail, the variable valve opening and closing portion 16 may be embedded in one case.

In the standby state in which the engine is not operated, the variable valve 10 blocks the inlet of the direction change pipe 8. In this state, when high speed and high negative pressure (high speed area) are applied, the control signal (pulse signal) is output from ECU11. The control signal input through the electric wire passes through the solenoid coil 18 connected to the connection terminal 20, thereby generating a magnetic force. By the magnetic force, the operating rod 17 inserted into the solenoid coil 18 is moved to open the variable valve 10. At this time, the control signal should supply sufficient current so that sufficient force acts in consideration of the elastic force of the spring 19.

In the ECU 11 which outputs the control signal, the opening and closing degree is determined by measuring the RPM of the engine. At this time, the opening and closing degree (valve opening duty) can be adjusted by varying the magnetic force in accordance with the control signal from the ECU 11. However, if the engine rotation speed (RPMth) (3,500 RPM in the present invention) is greater than or equal to 2, It can also be configured in stages and these can be changed according to the vehicle to which the present invention is applied.

In addition, the opening and closing blade operation unit 12 is to rotate the opening and closing blade 21 along the outer circumferential surface of the outflow pipe 9 to open or shield the hole 9a, and also in accordance with a control signal from the ECU 11. It works.

For a detailed structure of the opening and closing blade operation unit 12, referring to the AA line cut surface of Figure 2, the outer body is installed so that the holes (9a) are exposed in the portion where the hole (9a) of the outflow pipe (9) is located. 13, a solenoid coil 14 which is provided adjacent to one end of the inner surface of the outer body 13 and generates magnetic force in accordance with a control signal from the ECU 11, and from the solenoid coil 14; It is rotated according to the generated magnetic force to block the hole (9a), one side end includes a opening and closing blade 21 is fixed to the inner end of the outer body 13 by a spring (15). Although not shown in detail, the opening and closing blade 21 is guided by a guide formed in the outer body 13 and is configured to close the surface of the hole 9a to shield the holes 9a.

The opening and closing blade operation unit 12 is controlled by using a control program preset by the ECU 11 by measuring the rotational speed of the engine and the opening degree of the throttle valve (not shown). In other words, the fuel consumption in the engine (consequently the exhaust gas amount) changes according to the opening ratio of the throttle (valve). In the low speed region below the set speed (RPMth), the hole 9a is moved in the direction of decreasing noise. By adjusting the opening and closing degree (blade closing duty) of the opening and closing blades 21 to block the noise can be reduced by maintaining an optimal state. At this time, the variable valve 10 is kept below the set rotation speed because it is. Above the set rotation speed, all of the holes 9a are operated to open.

In the present invention, the variable valve opening and closing unit 16 and the opening and closing blade operating unit 12 is operated in an independent state from each other, the variable valve opening and closing unit 16 is operated based on the number of revolutions of the engine, the opening and closing blade operating unit 12 Is operated by referring to the rotational speed and the opening degree of the throttle valve. The rotation speed and the throttle opening rate are detected by the ECU 11 of the conventional vehicle.

The operating state of the back pressure reducing muffler of the present invention having the configuration as described above is as follows.

First, the operation of the opening and closing blade operating unit 12 will be described with reference to FIG. 5. After the driving of the vehicle is started, the ECU 11 measures the engine speed RPM and the throttle opening rate% / s. It is determined whether the rotation speed exceeds the set rotation speed (RPMth). The set rotation speed (RPMth) is a high speed region which is greatly affected by the back pressure, and the rotation speed is an area of 3500 RPM or more. Of course, it is apparent that this set rotation speed (RPMth) can be changed depending on the vehicle.

When the measured rotation speed exceeds the set rotation speed (RPMth), the ECU 11 opens the open / close blade 21 completely to discharge the exhaust gas. This state is shown in FIG. 3A. At this time, the independently operated variable valve opening and closing portion 16 is also opened to reduce the back pressure by discharging the exhaust gas.

If the measurement speed is less than the set speed (RPMth), it is determined whether the throttle opening rate (% / s) exceeds the upper limit of the opening rate. The upper limit of the opening rate is the maximum allowable muffler to prevent noise generation in the low speed region, and if the throttle opening rate exceeds the upper limit of the opening rate, the opening and closing blade 21 is completely opened to exhaust the exhaust gas in the low speed region. In this low speed region, the variable valve opening and closing portion 16 is closed.

However, if the throttle opening rate is lower than the upper limit of the opening rate, the closing ratio of the opening / closing blade 21, that is, the blade closing duty is calculated according to the throttle opening rate. The blade closing duty may be expressed as f (throttle opening rate), which is a throttle opening rate function, and becomes a linearly changing function. After the blade closing duty is calculated by the ECU 11 as described above, the ECU 11 outputs a control signal to move the opening / closing blade 21 according to the calculated duty value. At this time, the throttle opening rate can be divided into several stages, and the opening stage can be subdivided according to the calculated duty value.

3a-3c shows the operating state of the opening and closing blade 21 operated by the opening and closing blade operation unit 12, Figure 3a is a state in which the opening and closing blade 21 is completely open, Figure 3b is slightly closed, 3C shows the almost closed state, respectively. The movement of the opening / closing blade 21 is performed by the magnetic force generated by the solenoid coil 14 by a control signal (pulse signal) output from the ECU 11. The magnetic force should be set to apply a force large enough to allow the opening and closing blade 21 to move in consideration of the elastic force of the spring 15.

On the other hand, as shown in Figure 6, the operating state of the variable valve opening and closing unit 16, the rotation speed is measured in the ECU 11, if the measured rotation speed does not exceed the set rotation speed (RPMth) variable valve 10 Remains closed. In the state in which the variable valve 10 is closed, only the opening and closing blade 21 by the opening and closing blade operating unit 12 is operated to exhaust the exhaust gas and reduce noise.

However, when the rotation speed exceeds the set rotation speed (RPMth), the ECU 11 calculates the valve opening ratio, that is, the valve opening duty. The valve opening duty is expressed as f (rpm), which is a rotational function, and is a linearly varying function. As described above, the variable valve 10 is opened in accordance with the change in rotational speed, so that a large amount of exhaust gas is released, thereby reducing the back pressure. The blade closing duty or the valve opening duty are not fixed values but may have different values depending on the vehicle.

Due to this feature, the back pressure reducing muffler according to the present invention does not need to change the pipe diameter of the muffler or the spring force of the spring according to the type of the vehicle, and the blade closing duty or the valve opening duty value required by each vehicle is tested by experiment. The optimum point can be set and applied to the ECU 11.

As described above, according to the present invention, a movable opening and closing blade is installed around the outlet pipe hole to control the area where the exhaust gas passes when the engine is bouncing, to improve noise, and to control the opening and closing of the valve at high speed and high load. There is an effect that can reduce the back pressure.

1 is a side cross-sectional view showing the structure of a conventional muffler;

Figure 2 is a side cross-sectional view showing the structure of the muffler for back pressure reduction of the present invention.

3a-3c is an operating state of the opening and closing blades of the muffler of the present invention,

4 is a cross-sectional view taken along the line A-A of FIG.

5 is an operating state of the opening and closing blade operation unit installed in the outflow pipe,

6 is an operating state diagram of the variable valve opening and closing portion installed in the variable valve.

※ Explanation of code for main part of drawing ※

1: muffler case 2, 3: partition wall

4,5,6: Closed space 7: (Exhaust gas) Inflow pipe

7a, 9a: Hole 8: diverting pipe

9: (exhaust gas) outflow pipe 10: variable valve

11: ECU 12: opening and closing blade operating part

13: outer body 14, 18: solenoid coil

15,19: spring 16: variable valve opening

17: Operating rod 20, 20a: Connection terminal

21: opening and closing blade

Claims (4)

After partitioning into a plurality of closed spaces (4, 5, 6) using a plurality of partitions (2, 3), the exhaust gas flows in through the inlet pipe (7) in which the hole (7a) is formed from the engine, and the variable valve ( In the muffler which discharges gas by using the divert pipe (8) attached and the outflow pipe (9) in which the hole (9a) is formed, A variable valve opening / closing unit 16 for adjusting the opening / closing degree of the variable valve 10, an opening / closing blade operating unit 12 for closing the hole 9a in steps by moving the opening / closing blade 21, and a vehicle Measuring the engine speed and the throttle opening degree and controlling the opening and closing degree of the opening and closing blades 21 of the variable valve 10 and the opening and closing blade operating portion 12 of the variable valve opening and closing portion 16 according to the exhaust gas amount according to the exhaust gas amount. ECU 11, The opening and closing blade operation unit 12, the outer body 13 is installed so that the holes (9a) are exposed in the portion where the hole (9a) of the outflow pipe (9), and the inner surface of the outer body (13) It is installed adjacent to one end and rotated according to the magnetic force generated from the solenoid coil 14 and the solenoid coil 14 to generate a magnetic force in accordance with the control signal from the ECU 11 for blocking the hole 9a. Muffler for reducing the back pressure, characterized in that one side end includes an opening and closing blade 21 is fixed to the inner end of the outer body 13 by a spring (15). delete The method of claim 1, The variable valve opening and closing portion 16 is the operating rod 17 is connected to the outer surface and one end of the variable valve 10, the spring 19 is connected to the other end of the operating rod 17, the spring 19 Is connected to the other end of the terminal and connected to the connection terminal 20 to which the control signal is transmitted from the ECU 11 and the wire connected to the connection terminal 20 and installed on the outer circumferential surface of the operation rod 17. A muffler for reducing the back pressure, comprising a solenoid coil (18) for generating a magnetic force by a supplied current (pulse control signal). The method of claim 1, The back pressure reducing muffler is classified into a low speed region and a high speed region on the basis of a set rotational speed (RPMth), and a set back rotational speed (RPMth) is set to 3500 RPM.