RU22329U1 - LOW NOISE ACOUSTIC MOTOR STAND - Google Patents

Description

LOW NOISE ACOUSTIC MOTOR STAND.

The utility model relates to control and diagnostic equipment, in particular, to a test bench for conducting vibroacoustic bench studies of internal combustion engines (hereinafter - ICE).

To determine the main technical parameters of the internal combustion engine, special test benches equipped with various devices and measuring equipment are used.

As the basic equipment, the ICE test bench contains:

-autonomous (vibration-insulated) foundation for absorbing vibrations arising from the action of unbalanced forces and moments of inertia in the engine;

- foundation plate (groove) for installing the investigated engine and brake;

-Racks for installing and fixing ICE on a foundation plate; - load brake (hydraulic, electric) for absorption

developed ICE power with a torque measuring device on the motor shaft (brakes);

-shaft and special couplings for connecting the ICE crankshaft to the brake shaft;

-devices and communications for supplying a cooled lubricating oil, engine coolant to the engine cooling engine, exhaust into the atmosphere of exhaust and crankcase gases of the engine;

-devices and communications for powering the engine with fuel and air with appropriate sensors and devices for measuring flow, temperature, air and fuel pressures;

-special devices for regulating and determining individual parameters that affect the working process and ICE indicators (ignition timing, composition of the mixture, timing of the start of injection);

-systems providing regulation and control of ICE in the process of testing;

- remote control with the start-up and control elements of the engine;

-devices for monitoring the operation of the engine and devices for recording measured values;

-additional devices and devices intended for special studies in order to determine the individual parameters of the internal combustion engine (toxicity, smoke, noise, vibration, thermal stress, deformation of individual parts, etc.).

For conducting vibroacoustic bench research and development work on internal combustion engines, specialized load stands installed in special acoustic (semi-muffled or anechoic) chambers are widely used.

A well-known example of the use of a semi-muffled acoustic camera company Chrysler (USA), see publication Adam Gavine. The American Way. Testing Technology International, November, 2000, p. 28 ... 31 (attached), and the acoustic motor stand of the central avtopolygon GUP NITSIAMT (Dmitrov, Moscow region) with a hard sound-reflecting floor, on the groove plate of which with the help of special racks the ICE under investigation is fixed, see GUP NITSIAMT “Acoustic Center will execute :. Automotive Industry, 2000, No. 11, p. 1 (attached). In these examples, the braking (or driving — in the engine scrolling modes without implementing the workflow in it) bench installations (there are 2 of them) are at the same level outside the acoustic chamber and are located outside the chamber walls in the adjacent room (machine room). The ICE under study with a brake balancing machine is connected using special drive shafts (power take-off shafts), which provide transmission of torque or braking torque between the engine and the brake. The end sections of the drive shafts are installed in the bearing units and secured with

using special racks to the groove plate and directly to the surface of the chamber floor. Pipelines and various communication elements of the power supply, cooling, and exhaust gases are removed from the space of the acoustic chamber through special soundproof openings in the floor (groove plate) or chamber walls to the machine room of the stand, equipped with various technological systems and units for ensuring the functioning of the stand.

In the publication of Peter Gutzmer und Reimer Pilgrim. Motorakustische Versuchsund Meptechnik bei Porsche. MTZ, Motortechnische Zeitschrift, 48 (1987), 2, b. 47 ... 50 (attached), presents the concept of an acoustic motor stand used in the research center of Porsche (Germany). In this case, it provides for the use of a brake (nafuzochny) stand mounted in the center of the chamber below the floor surface of a completely muffled anechoic acoustic chamber. The transmission of torque (braking) is carried out with an endless flexible connection - smoothly belt drive. In this case, the floor of the acoustic chamber is made completely vibration-proof from the autonomous foundation, on which the drive (brake) stand is installed, and its surface (floors) is covered with effective noise-absorbing material (special

sound-absorbing wedges).

For the prototype adopted well-known from the patent of the Russian Federation No. 2107175, IPC F02B 79/00, G01M 15/00, publ. 03/20/98, a technical solution for the execution of a stand for running-in and testing an internal combustion engine, containing a base, a load (brake) and connecting devices. On the base are fixed longitudinal guides on which a frame is made, made in the form of autonomous beams. Beams are installed with the possibility of movement along the longitudinal guides and fixing relative to them. Transverse guides are fixed on the beams, on which racks are installed with the possibility of moving along them and fixing. The racks are fixed lodges for placing the engine with the ability to move and fix in a selected spatial direction.

high vibrational excitability and vibration conductivity. in particular, the used all-metal racks, tool holders, transverse and longitudinal guides, autonomous frame beams provide intensive vibration transfer of dynamic excitation from a working internal combustion engine (from unbalanced forces and moments of inertia) to the mating zones of the groove plate and the chamber floor, causing noise spurious radiation from the plate and floor, which reduces the accuracy and objectivity of acoustic measurements. The used all-metal massive elements (longitudinal and transverse guides, lodgements, autonomous frame beams) are easily excited by the dynamic forces generated by both the internal combustion engine and the drive (brake) units of the stand, vibrate and emit structural noise. In particular, a strong negative effect of spurious noise radiation of these elements of the stand occurs in the resonant modes of bending vibrations of the longitudinal and transverse guide beams. These design flaws of the ICE mounting devices on the motor stand make it difficult to conduct high-quality, high-quality vibro-acoustic bench studies of ICE.

The proposed technical solution can significantly eliminate the above disadvantages.

The essence of the proposed utility model lies in the fact that in the known acoustic motor stand containing the ICE mounting system on the stand, made in the form of two longitudinal guide beams rigidly fixedly installed by means of a weld on the supporting frame, and two transverse guide beams, which are possible in the process mounting the internal combustion engine on a stand to move along the longitudinal rails and be fixed in the required position by means of fasteners (for example, pressure plates and tightening bolts) and mouldering a closed metal rectangular profile with a hollow section, the inner space of the profile of the guide beams is filled with loose vibrodamping substance (for example, quartz sand, lead, cast iron, or a combination of these substances in a mixture in predetermined proportions); the upper surfaces of the guide beams have longitudinal grooves designed to move along them and fix in the required position the transverse guides and vertical racks, closed with removable protective vibration-damping rubber seals;

the ends of the beams are closed by removable covers, the inner surface of which is lined with a volumetric elastic damping element, and the side surfaces of the cover have grooves that allow the cover to be fixedly fixed after being installed in the end of the beam using threaded elements (for example, a clamping bolt and washer).

The device of the utility model is illustrated graphically.

In FIG. 1 shows a completely muffled anechoic acoustic chamber 1, with a drive (brake) balancing asynchronous (or direct current) machine 3 mounted below the floor surface 2 on an autonomous foundation vibration-proofed by special springs 4 5. The inner concrete shell 6 of chamber 1 is installed around the perimeter of floor 7 on special springs 8, and is completely isolated from the outer concrete shell 9 (the principle of construction is “chamber in chamber”). The floor 10 of the acoustic chamber 1 is vibration-insulated from the foundation 5, on which a balancing asynchronous machine 3 is installed, with rubber seals 11. The surface of the floor 10, walls 6 and ceiling 12 of the chamber 1 is covered with special sound-absorbing wedges 13. The balancing asynchronous machine 3 transmits torque (braking) moment through lower shaft 14 installed in the housing 15 of the lower support bearing assembly, drive belt 16, upper shaft 18, closed by a protective casing 19. The rotation area of the drive belt 16 is closed by a protective casing 17. The test object is ICE 2 0 is mounted through special elastic rubber-metal supports 21 on vertical racks 22, which are able to move along the transverse rails 23 and be fixed in the required position during the installation of ICE on the stand. The transverse rails 23, in turn, freely move and are fixed along the longitudinal rails 24 in an unsecured state 24. The longitudinal rails 24 of the ICE fastening system, struts 25 of the protective casing 19, the housing 26 of the upper support bearing assembly are mounted on a load-bearing frame 27. The floor of the test chamber 1 is a soundproof grilles 28, vibration-insulated from the frame 29 of the supporting power frame 27. The air cavity of the chamber 1 is ventilated by a high-performance supply 30 and exhaust 31 valves tion.

two on the motor stand in the form of two longitudinal guides 24 fixed by means of a weld on the supporting frame 29, and two transverse guides 23, which are able to move along the longitudinal guides 24 and be fixed in the required position by means of pressure plates 32 during the installation of ICE on the stand and tightening bolts 33. The transverse 23 and longitudinal 24 guide beams have a metal closed, with a hollow section, rectangular profile 34, which subsequently allows you to fill the inner space This profile is an effective loose vibrodamping substance 35 (for example, quartz sand, lead, cast iron, or a combination of these substances in mixtures in predetermined proportions) to provide a high noise vibration damping effect in the structure of beams. The upper surface of the guides 23 and 24 has a longitudinal groove closed by a removable protective and vibration-damping rubber seal 36. The use in the design of the guide beams 23 and 24 of the grooves is caused by the need to ensure the possibility of a given movement and fixation in the required position of the transverse guides 23 and vertical racks 22 during mounting and centering work when setting a specific ICE model on a stand. After completing the installation and alignment work, the longitudinal grooves are closed with a rubber seal 36, which seals and prevents the vibration-damping substance 35 from spilling out, and, in addition, it additionally damps the structural vibration that occurs at the individual resonant modes of the bench operation. and transverse 23 guide beams are closed by removable covers 37, the inner surface of which is lined with a volumetric, elastic, damping element 38, which allows not only to suppress the vibration of the end surfaces of the covers 37, but also to perform the additional function of a seal of the vibration damping substance 35 in the cavities of the guide beams 23 and 24, which, thus, increases the efficiency of use of the damping bulk material 35. The side surfaces of the end removable covers 37 have grooves 39, which make it possible to reliably fix the lid 37 securely after its installation in the end of the beam 23 or 24 using the clamping bolt 40 and washer 41. The use of the internal combustion engine mounting system on the stand is removable end caps provides

Wl / UL

the possibility of free removal of vibration damping granular material 35 to facilitate installation and alignment work during installation of various ICE models on a stand, or, if necessary, replacing vibration damping substance 35.

Practical implementation of the proposed design can significantly reduce spurious structural noise emitted by vibro-loaded elements of the ICE mounting system on the stand, ensure high acoustic quality to the stand and, thus, increase the accuracy and objectivity of bench-top vibroacoustic tests of ICE.

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Claims (1)

A low-noise acoustic motor stand containing an ICE mounting system on a stand made in the form of two longitudinal guide beams rigidly fixedly installed by means of a weld on the supporting frame, and two transverse guide beams that can move along the longitudinal guides during installation of the ICE on the stand and be fixed in the required position by means of fasteners, while the transverse and longitudinal guide beams have a metal closed rectangular profile from voids an empty cross-section, characterized in that the inner space of the profile of the guide beams is filled with a loose vibration damping substance; the upper surface of the guides has a longitudinal groove closed by a removable protective and vibration-damping rubber seal, the ends of the beams are closed by removable covers, the inner surface of which is lined with a volumetric elastic damping element, and the lateral surfaces of the covers are provided with grooves in which the cover is secured to the end of the beam using threaded elements.