JPH0687617U - Silencer - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a silencer, in which a plurality of silencing center frequencies can be set in one resonance chamber by opening and closing a valve that opens and closes an exhaust gas flow path. It is an object of the present invention to provide a simple muffler having a structure that does not require electronic valve opening / closing control as described above. In a muffler in which a resonance chamber is provided by partitioning an outer cylinder inside 1 whose both ends are closed by end plates 3 and 5 with a partition plate 9 into which a resonance tube 21 is inserted, A valve for partitioning and forming a plurality of pipelines by partitioning by a partition member extending in the axial direction and opening and closing the pipelines in other pipelines except one pipeline by pulsating pressure ejected from the cylinder of the engine. It is characterized by wearing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a silencer mounted on a vehicle exhaust system.

[0002]

[Prior art]

 In order to improve comfort, which is one of the commercial characteristics of automobiles, there is a demand for reduction of vehicle interior noise, and a demand for lower exhaust noise to the exhaust noise suppression system in order to improve quietness inside the vehicle year by year. Is getting stronger.

“Muffled noise” is a problem in enhancing quietness of vehicle interior noise. The muffled noise is the noise generated when a relatively low-frequency noise is generated and resonates by forming a standing wave due to the reflection between the front and rear windows in the passenger compartment only in a certain vehicle speed range while driving. However, as the level increases, the passengers will feel a sense of pressure.

Therefore, in order to reduce exhaust noise when the vehicle is running, conventionally, a silencer as disclosed in Japanese Utility Model Laid-Open No. 59-100912 is attached to a vehicle exhaust system to provide a relatively low frequency component. Exhaust noise is reduced by the resonance damping effect in the resonance chamber.

In addition, recently, as in the control type silencer disclosed in Japanese Utility Model Laid-Open No. 62-24007, two tail tubes are attached to the silencer, and when the engine is operated in the middle and high rotation speeds. A control valve that opens the exhaust gas flow path is installed on one side of the tail tube to reduce pulsating noise when the engine is running at low speeds, and to reduce airflow noise when the engine is running at high or low speeds. Equipment is installed in many vehicles.

[0006]

[Problems to be solved by the device]

 However, in the above-mentioned conventional silencer, the silencing center frequency is limited depending on the volume of the resonance chamber, the length of the resonance tube, and the pipe diameter, so that the engine's low-rotation region can be operated at medium to high rotation speeds. There was a problem that low frequency components in a wide range over the area could not be efficiently reduced.

Further, in the conventional control type silencer as disclosed in Japanese Utility Model Laid-Open No. 62-24007, engine information is input to the control means to electronically control the opening and closing of the control valve. However, the structure is extremely complicated and the cost is very high.

The present invention has been devised in view of such a situation, and it is possible to set a plurality of silencing center frequencies in one resonance chamber by opening and closing a valve that opens and closes an exhaust gas passage. It is an object of the present invention to provide a simple silencer having a structure that does not require the electronic opening / closing control of a valve as in the past.

[0009]

[Means for Solving the Problems]

 In order to achieve such an object, a muffler according to claim 1 is a muffler in which a resonance chamber is provided by partitioning the inside of an outer cylinder whose both end openings are closed by end plates with a partition plate into which a resonance tube is inserted. In the above, the resonance pipe is partitioned by a partition member extending in the axial direction to partition and form a plurality of pipes, and the pipes are ejected from the cylinder of the engine to other pipes except one pipe. It is equipped with a valve that opens and closes the flow path by pulsating pressure.

In the silencer according to claim 2, the resonance pipe is divided into three or more pipe lines by a partition member, and the weight of the silencer is changed so that the valve sequentially opens and closes according to the pulsating pressure. Is characterized by.

[0011]

[Action]

 According to the inventions according to each claim, the pulsating pressure force ejected from the cylinder when the engine is driven is transmitted to the muffler, but when the pulsating pressure does not have enough momentum to open the valve such as when the engine is running at low speed. Since the valve closes its flow path, the initial silencing center frequency was tuned in advance by the mounting position of the partitioning member that partitions the inside of the resonance tube, that is, the diameter and length of the conduit without the valve installed. The exhaust noise of a specific low frequency component, which is determined by the volume of the resonance chamber and the capacity of the resonance chamber, is silenced.

Then, when the engine shifts to the middle / high speed region and the pulsating pressure increases, the valve opens due to the pressure and the flow path is opened. Further, according to the invention of claim 2, the valves are sequentially opened. Since it is opened, the exhaust noise of a specific low frequency component, which is determined by the diameter and length of the open conduit of the flow path and the volume of the resonance chamber, is deviated due to the deviation of the silencing center frequency.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a silencer according to a first embodiment of the present invention, in which 1 is an outer cylinder whose both end openings are closed by end plates 3 and 5, and the inside of the outer cylinder 1 has two sheets. With the partition plates 7 and 9, three chambers, that is, a first chamber 11, a second chamber 13, and a third chamber 15 are defined from the upstream end plate 3 side.

An exhaust gas introduction pipe 17 is inserted into the upstream end plate 3 so as to penetrate the partition plate 7, and the exhaust gas introduction pipe 17 has an insertion side end opening into the second chamber 13. ing. Further, an exhaust lead-out pipe 19 is inserted into the downstream end plate 5 so as to penetrate both partition plates 7 and 9, and the exhaust lead-out pipe 19 has its insertion side end opened to the first chamber 11. ing.

Further, a resonance pipe 21 that connects the second chamber 13 and the third chamber 15 is inserted into the partition plate 9, and one communication pipe 23 is inserted into both partition plates 7 and 9. It is worn. A plurality of small holes 25 are formed in the peripheral wall of the communication pipe 23 located in the second chamber 13, so that the first chamber 11 and the second chamber 13 function as expansion chambers, and the third chamber 15 The pipe end of the communication pipe 23 located at is plugged with the plug 27 so that the third chamber 15 functions as a resonance chamber.

As shown in FIG. 2, the resonance tube 21 has two pipe lines 31 and 33 defined by one partition member 29 extending in the axial direction. At the downstream end of the pipe 33, a valve 35 that opens and closes the flow passage by pulsating pressure ejected from the cylinder of the engine is installed.

As shown in FIG. 3, the valve 35 is a semicircular plate having the same circular arc as the inner circumference of the resonance tube 21, and is attached to a single spindle 37 that penetrates the resonance tube 21 in the diameter direction. There is. Then, the valve 35 closes the conduit 33 as shown in FIG. 3 when the engine pulsating pressure ejected from the cylinder of the engine is low and the pulsating pressure is low. As shown in FIGS. 2 and 4, the valve 35 is opened by the pressure to open the flow path of the conduit 35.

As shown in FIG. 2, a stopper 39 is attached to one end of a spindle 37 protruding to the outer circumference of the communication pipe 23. The stopper 39 rotates in the direction of the arrow around the spindle 37 as the center of rotation when the valve 35 is opened and closed. However, the stopper 39 has two stopper receivers 41 on the outer periphery of the communication pipe 23 on the pipe end side. , 43 are provided at a predetermined interval, and when the valve 35 moves to a position substantially parallel to the partition member 29 as shown in FIG. 2 due to the pulsating pressure, the stopper 39 comes into contact with the stopper receiver 41 and the valve When the movement of the valve is regulated and the stopper 39 closes the conduit 33 as shown in FIG. 4, the stopper 39 similarly contacts the stopper receiver 43 to regulate the movement of the valve.

In addition, reference numeral 45 in the drawing denotes a bushing case of the spindle 37. Since the muffler according to the present embodiment is configured in this way, the pulsating pressure ejected from the cylinder due to the driving of the engine is propagated into the muffler through the exhaust introduction pipe 17, but Since the pulsating pressure at the time of rotation does not have enough momentum to open the valve 35, the valve 35 continues to close the conduit 33 of the resonance tube 21 as shown in FIG.

Therefore, the initial silencing center frequency at the time of low engine speed is tuned in advance by the mounting position of the partition member 29 that partitions the inside of the resonance tube 21, that is, the diameter of the conduit 31 and its length, and Therefore, the exhaust noise of a specific low frequency component determined by the capacity of the third chamber 15 and the like is silenced.

When the engine shifts to the middle / high speed region and the pulsating pressure increases, the valve 35 is opened by the pressure and the flow path of the pipe 33 is opened as shown in FIGS. 2 and 4. Thus, the center frequency of the noise reduction shifts, and the exhaust noise of a specific low frequency component determined by the total diameters of the two conduits 31 and 33 of the resonance tube 21 and the length thereof, and the capacity of the third chamber 15 is suppressed. Will be done.

As described above, according to the present embodiment, by opening / closing the valve 35 by the pulsating pressure, it is possible to set two silencing center frequencies ranging from the low rotation region to the middle / high rotation region of the engine, thereby reducing exhaust noise. Low frequency components can be reduced to reduce vehicle interior noise (“muffled noise”).

FIG. 5 shows the difference in the silencing effect between the conventional silencer and the silencer according to the present embodiment, in which the horizontal axis represents the engine speed and the vertical axis represents the discharge noise. Thus, as is clear from such a graph, the silencer according to this embodiment can set two silencing center frequencies from the low rotation region to the medium and high rotation regions.

However, according to this embodiment, since the valve 35 is opened and closed by the pulsating pressure as described above, the engine information is input to the control means as in the conventional control silencer described above. Since it is not necessary to open and close the control valve by electronic control, the cost can be reduced.

FIG. 6 is a perspective view of a downstream pipe end of a resonance pipe used in a muffler according to a second embodiment of the present invention. The configuration except the devised portion is the same as that of the first embodiment. Therefore, the description of them will be omitted here, and only the devised part will be explained. The same parts as those in the first embodiment are designated by the same reference numerals.

In FIG. 6, reference numeral 47 denotes a resonance tube inserted into the partition plate 9, and the resonance tube 47 in the present embodiment is formed by a partition member 49 extending in the axial direction and having a substantially Y-shaped cross section. It is divided into two parts, and thereby, three conduits 51, 53, 55 having a fan-shaped cross section with a central angle of 120 ° are formed.

Then, as shown in the drawing, valves 57 and 59 for opening and closing the flow passages by the pulsating pressure ejected from the cylinder of the engine are respectively provided at the downstream end portions of the two pipelines 53 and 55, respectively. It is attached via 61.

Both valves 57 and 59 are fan-shaped plates having the same cross-sectional shape as the pipe lines 53 and 55. The plate thickness and the specific gravity are set so that the valve 57 opens and closes first when the pulsating pressure increases. The weight is adjusted to be different.

Further, as shown in FIG. 7, back springs 63 are arranged on the surfaces of the hinges 61, respectively, and when the pulsating pressure becomes low, the valves 57 and 59 return by the restoring force of the back springs 63. Then, the respective pipelines 53 and 55 are closed.

Since the muffler according to the second embodiment is provided with the resonance pipe 47 having such a configuration, the pulsating pressure ejected from the cylinder by the drive of the engine enters the muffler through the exhaust introduction pipe 17. Although transmitted, the pulsating pressure at the time of low engine speed does not have enough momentum to open the valves 57 and 59, so that the valves 57 and 59 continue to close the respective conduits 53 and 55.

Therefore, as for the initial muffling center frequency at the time of low engine speed, the exhaust noise of a specific low frequency component determined by the diameter and the length of the conduit 51, the capacity of the third chamber 15, etc. is muffled. The Rukoto.

When the engine shifts to the medium / high speed region and the pulsating pressure gradually increases, the valve 57 is opened and the flow path of the pipe line 53 is opened, so that the silencing center frequency is shifted. The exhaust noise of a specific low frequency component determined by the total diameter of the pipe lines 51 and 53 and the length thereof, the capacity of the third chamber 15 and the like is silenced. When the pulsating pressure is further increased, the valve 59 is opened and the flow path of the pipe line 55 is also opened. Therefore, the sound deadening center frequency is deviated, and the total diameter of the pipe lines 51, 53, 55 and the resonance pipe 47 Exhaust noise of a specific low frequency component determined by the length and the capacity of the third chamber 15 is silenced.

As described above, according to the present embodiment, by opening and closing the valves 57 and 59 by the pulsating pressure, as shown in FIG. 5, there are three silencing centers from the low rotation region to the middle and high rotation regions of the engine. Since the frequency can be set, it is possible to reduce low-frequency components of exhaust noise and reduce vehicle interior noise.

Of course, according to the present embodiment as well, it is not necessary to open and close the control valve by electronic control unlike the conventional control type silencer, so that the cost can be reduced. In the first embodiment, the partition tube 29 divides the resonance pipe 21 into two conduits 31 and 33. In the second embodiment, the partition member 49 separates the resonance tube 47 into three conduits 51 and 33. Although it is divided into 53 and 55, if the resonance tube is further subdivided and valves are attached to the other conduits except one conduit, these are opened sequentially according to the pulsating pressure. Multiple resonance center frequencies can be set in one resonance chamber.

[0035]

[Effect of device]

 As described above, according to the invention described in each claim, it is possible to set a plurality of silencing center frequencies in one resonance chamber by opening and closing the valve and dividing the inside of the resonance tube. It is possible to reduce low-frequency components of exhaust noise in the range from the middle to high rotation range, and it is possible to reduce vehicle interior noise.

According to the invention described in each claim, it is unnecessary to open and close the control valve by electronic control unlike the conventional control type silencer, so that the cost can be reduced. .

[Brief description of drawings]

FIG. 1 is a sectional view of a silencer according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway sectional view of a resonance tube.

FIG. 3 is a front view of the downstream tube end of the resonance tube with the valve closed.

FIG. 4 is a front view of the downstream tube end of the resonance tube with the valve opened.

FIG. 5 is a graph comparing the difference in the silencing effect between the conventional silencer and the silencers according to the first and second embodiments of the present invention.

FIG. 6 is a perspective view of a downstream tube end of a resonance tube according to a second embodiment of the present invention.

7 is a cross-sectional view of a main part of the resonance tube shown in FIG.

[Explanation of symbols]

 1 Outer Cylinder 3,5 End Plate 7,9 Partition Plate 11 First Chamber 13 Second Chamber 15 Third Chamber 17 Exhaust Inlet Pipe 19 Exhaust Outlet Pipe 21,47 Resonance Pipe 23 Communication Pipe 29,49 Partition Member 31,33, 51, 53, 55 Pipe line 35, 57, 59 Valve 37 Spindle 39 Stopper 41, 43 Stopper holder 61 Hinges

Claims (2)

[Scope of utility model registration request] 1. A resonance chamber is provided by partitioning an inside of an outer cylinder (1) whose both openings are closed by end plates (3, 5) with a partition plate (9) into which a resonance tube (21, 47) is inserted. In the muffler, the resonance pipe (21) is partitioned by a partition member (29) extending in the axial direction to partition and form a plurality of pipe lines (31, 33) and one pipe line (31). A silencer characterized in that a valve (35) that opens and closes the flow passage by pulsating pressure ejected from the cylinder of the engine is attached to the other pipelines (33) other than the above. 2. The resonance pipe (47) is divided into three or more pipe lines (51, 53, 55) by a partition member (49), and the valves (57, 59) are sequentially arranged in accordance with the pulsating pressure. The silencer according to claim 1, wherein the silencers have different weights so as to open and close.