RU50308U1 - EXHAUST GAS REMOTE SYSTEM FOR A DYNAMIC STAND WITH RUNNING DRUMS USED FOR ACOUSTIC TESTS OF VEHICLES - Google Patents

Abstract

The utility model relates to remote exhaust systems of the exhaust system of the exhaust gas of an internal combustion engine (hereinafter ICE) of a vehicle during bench vibroacoustic tests.

The device, in particular, contains a ventilation unit for forced exhaust extraction, pipelines of the technological exhaust system, technological silencers, an open conical socket mounted at a certain distance from the exhaust pipe cut.

What is new is that in the space of a semi-anechoic chamber, the remote suction system is equipped with a rotary connecting element in the form of a tubular elbow with flanges connected to the exhaust exhaust channel; the inlet portion of the tubular elbow is inserted into the pipeline of the suction process system, the mounting flange of the rotary connecting element contacts the floor of the test chamber through a sealing vibration-isolating element, while the rotary connecting element is mounted to rotate around its vertical axis to establish a predetermined oriented direction of the exhaust exhaust channel; the outlet channel is made in the form of a perforated metal pipe lined with fiberglass, while the outer surface of the pipe is covered by a sound-absorbing cover made of porous, fibrous or open-cell foam material, lined, in turn, with a protective, soundproof, gas-tight layer; the outlet channel contains flanges for connection, on the one hand, with a cylindrical nozzle of an open conical socket, and on the other hand, with a rotatable connecting element, while part of the outlet channel is made in the form of a flexible section, for example, a hose.

Thanks to the utility model, it has become possible to provide an effective low-noise exhaust gas exhaust for the ICE of the vehicle under study, while eliminating the occurrence of gas contamination in the test chamber.

Description

The utility model relates to remote exhaust systems of the exhaust system of the exhaust gas of an internal combustion engine (hereinafter ICE) of a vehicle during bench vibroacoustic tests. In this case, the tail pipe section of the exhaust silencer is free and exhaust is emitted, the sound of the exhaust is emitted directly into the open space of the room in which the vehicle under investigation is installed on the stand. The application of such a test execution concept is related to the need to measure the exhaust noise produced by an open cut of the tail pipe of the muffler of the vehicle exhaust system. Such a procedure, in turn, requires the use of an exhaust gas suction system that is sufficiently efficient in terms of productivity and low noise emission with a device for collecting these gases located near the cutoff zone of the tail pipe and the measuring microphone of the sound level meter (frequency analyzer).

A known element of the exhaust ventilation system of high pressure (application Germany No. 3832030, IPC 5 G 10 K 11/16, publ. 03/29/90 No. 13) using several interconnected and blocked pipes and a sound-absorbing panel, characterized by complexity, relatively high hydraulic resistance and limited application .

Known noise suppression element, built into the route of the blower (application Germany No. 3830346, IPC 5 G 10 K 11/16, F 16 L 55/02, 32 V 3/24, 5/18, publ. March 15, 90 No. 11), characterized by the use of open-cell foam, corrugated perforated hose, fitted with a sound-absorbing mat. The device is applicable only to systems

air supply, is not protected from the effects of particulate matter and condensate contained in the exhaust gases of the internal combustion engine, and is not able to carry out effective (remote - at a distance from the source) exhaust gas exhaust.

Known sound-absorbing system for ventilation and degassing ducts described in the application of Germany No. 3544022, MKI 4 G 10 K - 11/16, F 24 F 13/00, publ. 06/87/19 No. 25, containing a fibrous body and shutters made of mineral fibers and offset one from another. The use of the fibrous structure of the housing and the blinds allows to reduce the noise of the gas flow transported through the system. However, the geometric shape of the device does not allow it to be used as an effective remote intake of gases, and the absence of a special protective film on the surfaces of the housing and the blinds does not allow to avoid the loss of sound-absorbing qualities of the device during long-term operation, due to its coking by particles of condensate and soot contained in the exhaust gases ICE.

Known silencer for installation at the inlet and outlet ends of the flow channel for transporting a gaseous medium (application Germany No. 3432049, MKI 4 G 10 K 11/16, F 16 L 55/02, publ. 13.03.86 No. 11), containing a large number of partitions from sound-absorbing material suspended from special bearing rods. The disadvantage of this device is its bulkiness, which causes an additional noise-reflecting effect, undesirable for devices for remote exhaust gas.

A device is known in the form of a tip of a sound-absorbing pipe (French patent No. 2644923, IPC 5 G 10 K 11/16, F 24 F 7/06, 13/24, publ. 09/28/90 No. 39), in which sound-absorbing partitions are located. The partitions are perpendicular to the flow, which allows to increase the sound-absorbing effect with small dimensions of the device. An obvious disadvantage of the device is its increased hydraulic resistance, which is unacceptable in the area of the open intake of exhaust gases of the internal combustion engine emitted into the surrounding space by a free cut of the exhaust pipe of the vehicle engine.

Known silencer for the channel of the expiration of a gaseous medium (application Germany No. 3401210, MKI 4 G 10 K 11/16, F 02 M 35/12, F 01 N 1/24, publ. 25.07.85 No. 30), comprising a body of sound-absorbing material . An annular channel is made inside the housing and the perimeter of the channel cross section expands from the zone

gas outflow. This design allows you to increase the sound absorption effect from the use of a large area of sound absorption in a cone-shaped annular channel. However, a large contact surface area of pulsating gas transported through the device in a narrow slotted annular channel, in the case of its large mass (volume) flow, causes a significant increase in the hydraulic resistance of the tract. Also, the considered device cannot be used for the purposes of effective remote gas suction by installation from a gas outflow zone with a certain distance.

A device is known according to the application of Japan No. 62-55160 MKI 4 G 10 K 11/16, 04 C 3/00, publ. 11/18/87 No. 6-1379, designed to suppress noise and remove foreign particles from the gas stream and used in research and development work on bench test installations such as a wind tunnel. The device contains a special channel for introducing (sucking) gas and directing it along a spiral path further along the space of the cylindrical body, the walls of which are lined with sound-absorbing material. The disadvantage of the device are:

- a large sound-reflecting effect from the outer surface of the wall casing, distorting the sound field in the area of the measuring microphone, close to the casing;

- increased hydraulic resistance caused by a change in the direction of transportation of the sucked gas stream through the device body (sharp turns of the stream).

A known design of a device for remote exhaust gas during bench vibration tests of a vehicle, which is described in the certificate of the Russian Federation for utility model No. 20399. A device for remote exhaust exhaust during vibro-acoustic bench tests of a car on a dynamometer with running drums is mounted in the exhaust pipe cut-off area of the main silencer of the car exhaust system and connected to the exhaust system of the exhaust ventilation system, made in the form of a truncated mobile suction bell shaped like a truncated open half cone, the outer and inner walls of which are lined with sound-absorbing material ohm, lined with a protective film and installed at a certain distance from the cut of the exhaust pipe, and

equipped with a cylindrical connecting nozzle for connecting the exhaust hose of the exhaust system of the exhaust ventilation system technological system, while the mobile remote bell is mounted on a supporting frame, which is additionally equipped with a condensate accumulator, a brake device, a control handle and wheels for transportation. This device for remote exhaust suction can mitigate the negative impact on the external and internal noise of a car by the rigid installation of a removable exhaust hose of a technological exhaust suction hose to the tail pipe of a vehicle exhaust system, and reduce the entry of chemically active condensate contained in exhaust gases into the process line suction systems. A disadvantage of the design of the known device for remote exhaust exhaust suction during vibro-acoustic bench tests of a car on a dynamometer with running drums is the insufficient degree of noise suppression of the fan system used in the exhaust gas suction bench technology. The noise generated by the fan unit and distributed along the portion of the exhaust pipe of the vehicle engine exhaust from the fan unit towards the flexible exhaust hose and the open conical socket located in the open section of the tail pipe of the exhaust silencer of the vehicle engine exhaust system mounted on the stand, ultimately emitted into the space of a semi-anechoic test chamber in the installation area of the measuring microphone, it thus hampering holding quality acoustic research and, primarily, to make an objective assessment of characteristics shumozaglushayuschih silencing the exhaust noise of the test vehicle due to the reduction of the dynamic range of measurements, caused by an increase in the level of background noise generated by the fan installation system exhaust suction. Also, in known constructions, an additional “spurious” noise background can be emitted from the side of the engine room through the wall of the flexible suction hose installed in the technological opening of the floor of the test chamber.

The aforementioned drawback is eliminated in the design of a system for remote exhaust exhaust suction during vibro-acoustic bench tests of a car on a dynamometer stand with running drums,

placed in an acoustic semi-anechoic chamber, presented in the patent for utility model of the Russian Federation No. 30986, IPC G 01 M 19/00, publ. 07/10/2003, BI No. 19, accepted as a PROTOTYPE. The known system for remote exhaust extraction contains, in particular, a ventilation unit for forced exhaust extraction, a ventilation duct with exhaust gases to the atmosphere, pipelines of the exhaust system, process silencers, a flexible exhaust hose with an open conical socket installed at a certain distance from exhaust pipe cut. At the same time, the remote suction system contains a special receiver-silencer of a spherical shape, mounted on the pipeline section of the exhaust exhaust system. A disadvantage of the known remote exhaust suction system is a decrease in its performance caused by the use of a discharge hose and inlet and outlet pipes of the receiver-silencer and the creation of additional gas-hydrodynamic resistances with a spherical silencer mounted in the space of the semi-anechoic chamber. The low performance of the suction system can lead to excessive gas contamination of the test room with exhaust gases and contamination of the surface of the sound-absorbing wall and ceiling linings with solid exhaust particles (soot), which ultimately degrades the sound-absorbing characteristics of the liners and their aesthetic appearance. Also, resonant noise amplification is possible due to the excitation of the lower eigenmodes by the exhaust exhaust hose of the technological system of the exhaust ventilation installation.

The technical result of the utility model is to provide effective low-noise exhaust gas exhaust of the internal combustion engine of the investigated vehicle and to eliminate the occurrence of gas contamination in the room of the test chamber.

The specified technical result in the implementation of the utility model is achieved by the fact that in the known system of remote exhaust exhaust for a dynamic stand with running drums used in acoustic tests of vehicles in a semi-anechoic chamber, containing, in particular, a ventilation unit for forced exhaust exhaust, pipelines of the technological system exhaust, technological silencers, open conical bell mounted at a certain distance from the exhaust cut th pipe in space

in a semi-anechoic chamber, the remote suction system is equipped with a rotary connecting element in the form of a tubular elbow with flanges connected to the exhaust exhaust channel; the inlet section of the tubular elbow is inserted into the pipeline of the suction technological system, the mounting flange of the rotary connecting element contacts the floor of the test chamber through a sealing vibration-isolating element, while the design of the rotary connecting element has the ability to rotate around its vertical axis to establish a predetermined oriented direction of the exhaust exhaust channel; the outlet channel is made in the form of a perforated metal pipe lined with fiberglass, while the outer surface of the pipe is covered by a sound-absorbing cover of porous, fibrous or open-cell foam material, lined, in turn, with a thin protective, sound-transparent, gas-tight layer; the outlet channel contains flanges for connection on the one hand with a cylindrical nozzle of an open conical socket, and on the other hand with a rotary connecting element.

Comparison of scientific, technical and patent documentation on the priority date in the main and related sections of the MKI shows that the set of essential features of the claimed solution was not previously known, therefore, it meets the patentability condition of “novelty”.

The proposed technical solution is industrially applicable, because can be manufactured industrially, efficiently, feasibly and reproducibly, therefore, meets the patentability condition "industrial applicability.

The utility model is illustrated by drawings, where

Figure 1 shows a semi-anechoic acoustic chamber with a dynamic stand with running drums for acoustic research of vehicles, with a remote exhaust exhaust system installed therein, claimed as a utility model.

The positions in figure 1 are indicated:

1 - semi-anechoic acoustic chamber;

2 - sound-absorbing backstage;

3 - vibration damping springs;

4 - vibration base of the stand;

5 - running drums;

6 - electric winch;

7 - vehicle;

8 - fixing cable;

9 - mounting racks;

10 - supply and exhaust ventilation;

11 - video monitoring system;

12 - floor of the test chamber;

13 - rotary connecting element;

14 - exhaust channel exhaust exhaust;

15 - open conical bell;

16 - measuring microphone;

17 - measuring amplifier;

18 - recording device;

19 - pipeline technological system exhaust exhaust;

20 - technological silencer;

21 - ventilation duct;

22 - centrifugal ventilation installation;

23 - an exhaust pipe.

The installation of the inner shell of the semi-anechoic chamber 1 and the vibration base of the stand 4 on special springs 3, the facing of the wall and ceiling surfaces of the chamber with sound-absorbing wings 2, the technological noise mufflers 20 contribute to a low noise background in the test chamber. The elements of the dynamic stand, indicated by pos. 5, 6, 8, 9, 10, 11 are involved in ensuring the functioning of the technology of conducting acoustic tests of the vehicle. The elements indicated by pos.16-18, provide registration of acoustic signals of the test object under test.

Figure 2 presents a top view of a semi-anechoic acoustic chamber with a dynamic stand with running drums for acoustic research of vehicles, with different oriented directions of the constituent elements of the remote exhaust exhaust system claimed as a utility model depending on the position of the open cut of the tail of the exhaust pipe of the exhaust system exhaust gas of a vehicle engine (car).

Figure 3-4 presents fragments of the design of the inventive remote exhaust system for exhaust gases during bench acoustic tests of the car.

The remote exhaust gas suction system during acoustic bench tests of a vehicle contains a centrifugal ventilation unit 22 (see Fig. 1), which exhausts (exhausts) the exhaust gases through a process pipe 19, a ventilation duct 21 with their subsequent discharge into the external environment (atmosphere). To reduce noise from the ventilation unit and, accordingly, to reduce the transmission of noise generated by it through the ventilation duct and pipes of the suction system in the direction of the open cut of the conical socket 15 (measuring zone) into the space of the test chamber 1, with the measuring microphone 16 installed, into the path of the remote suction system technological silencers 20 are mounted. The design of technological silencers 20, on the one hand, should effectively drown out the fan noise, the noise of the exhaust stream internal combustion gases of the internal combustion engine, and on the other hand, to provide low hydraulic resistance of the pipe branches of the exhaust gas exhaust, damping elements and, accordingly, provide an effective (high-performance) exhaust gas used by the fan unit. These features are, for example, silencers, the designs of which are presented in the patents of the Russian Federation for utility model No. 43073, 43074, 43099, 43100.

Directly in the space of the semi-anechoic chamber, the remote exhaust exhaust system is equipped with a rotary connecting element 13, made in the form of a tubular metal elbow. On the one hand, the tubular elbow contains a connecting flange 24 for connecting to the exhaust gas duct 14, and on the other hand, a mounting flange 25 for installing the rotary connecting element 13 on the floor of the test chamber 12 at the outlet of the pipe section 19 of the exhaust system. The input section 26 of the element 13 is connected to the pipeline 19 without interference, which makes it possible to rotate the connecting element 13 around its vertical axis to establish a predetermined oriented direction of the attached exhaust channel 14 depending on the position of the open cut of the tail of the exhaust pipe of the vehicle exhaust system,

mounted on running drums, which, therefore, allows you to easily mount the exhaust channel 14 to the open conical bell of the remote exhaust gas 15. The mounting flange 25 contacts the floor 12 of the test chamber through a sealing vibration-soundproofing element in the form of an elastic-damping cuff 27 made of porous rubber, which allows to weaken the transmission of vibration by the hard way to the floor 12 of the test chamber and to reduce the emission of air "spurious" noise background from innogo compartment through the thin wall portion of the pipeline structure of the suction exhaust gases. The discharge channel 14 is made in the form of a metal pipe 28, the walls of which are perforated with holes. The perforated structure of the walls of the pipe of the outlet channel makes it possible to reduce their vibrational excitation and, accordingly, to reduce the emission of additional structural noise due to the formation of conditions for a short acoustic circuit through the perforation holes between the front and back sides of the walls. On the other hand, the perforated structure of the walls of the pipe of the outlet channel avoids amplification of the resonant transmission of sound energy in eigenmodes of oscillation of the air volume (column) enclosed in the space of the pipe of the outlet channel and, thus, eliminates the transmission of increased acoustic radiation into the space of the test chamber. To prevent the penetration of gases into the space of the test chamber, the outer surface of the perforated wall of the pipe 28 is lined with fiberglass 29, and is also covered by a sound-absorbing cover 30 of porous, fibrous or open-cell foam material, lined, in turn, with a thin protective sound-transparent gas-tight layer 31 (for example, heat-resistant moisture-proof soundproof foil). The connection of the sound-absorbing cover with the pipe of the outlet channel is carried out by adhesion due to the presence of a sticky adhesive layer in the composition of the sound-absorbing material. The external lining of the surface of the outlet channel with a sound-absorbing cover makes it possible to weaken not only the noise energy transported through the hose, but also to weaken the process of reflection of sound waves from the outside of the hose due to the absorption effect of sound waves propagating in the premises of an acoustic semi-anechoic chamber. In addition, structural sound radiation produced directly by the vibrating shell is further reduced.

a channel excited by both sound waves and gas-dynamic pulsations of the gas and sound exhaust streams transported through the hose and gas pulsations generated by a suction centrifugal ventilation unit. The ends of the pipe of the outlet channel contain flanges 32 and 33 for connecting it on the one hand with the docking flange 24 of the rotary connecting element 13, and on the other hand with the flange 34 of the cylindrical connecting nozzle 35 of the open conical socket 15. Reliable fixation of these connections is carried out by bolting. At least part of the outlet channel contains a flexible portion, for example, a hose (not shown in FIG.).

Thanks to the utility model, it has become possible to provide an effective low-noise exhaust gas exhaust for the ICE of the vehicle under study, while eliminating the occurrence of gas contamination in the test chamber.

Of course, the utility model is not limited to the described method of its implementation, shown in the attached figures. It remains possible to change various elements, or to replace them with technically equivalent ones, not going beyond the scope of the present utility model.

Claims (1)

Remote exhaust exhaust system for a dynamic stand with running drums, used for acoustic tests of vehicles in a semi-anechoic chamber, containing, in particular, a forced exhaust exhaust ventilation system, pipelines of the exhaust system, process silencers, an open cone mounted on a specific distance from the cut of the exhaust pipe, characterized in that in the space of the semi-anechoic chamber the remote suction system rudovannaya connecting element in the form of a tubular elbow with flanges connected to the exhaust channel of the exhaust gases, the inlet portion of the tubular elbow is inserted into the pipeline of the suction system, the mounting flange of the rotary connecting element is in contact with the floor of the test chamber through a sealing vibration-isolating element, while the rotary connecting element is installed rotatable around its vertical axis to establish a given oriented direction the exhaust exhaust channel, the exhaust channel is made in the form of a perforated metal pipe lined with fiberglass, while the outer surface of the pipe is covered by a sound-absorbing cover made of porous, fibrous or open-cellular foam material, lined in turn with a protective, sound-transparent, gas-tight layer, the exhaust channel contains flanges for connecting, on the one hand, with a cylindrical nozzle of an open conical socket, and on the other hand, with a rotary connecting element, with this part of the outlet channel is made in the form of a flexible section, such as a hose.