RU2783582C1 - Stand for acoustic testing of electro-hydraulic apparatus integrated with hydraulic fluid tanks of vehicles - Google Patents

Abstract

FIELD: testing.

SUBSTANCE: stand relates to supporting means for studies of the acoustic noise of electro-hydraulic units built into hydraulic fluid tanks of vehicles. Stand comprises recording and testing equipment, a power source, measuring microphones, a suspension, and a parallelepiped-shaped frame including racks and bolts. The suspension is made in the form of a netted pocket with the fixed on the bolts of the frame and the netting formed so as to be able to retain various tanks from the number of tanks integrated in the vehicle with the tested electro-hydraulic apparatus in the space between the frame elements. The netting of the pocket is formed with mutually intersecting shock-absorbing cords connected so as not to form knots at the intersection points thereof. The stand is equipped with a pumping unit and a pumped fluid storage configured to store the fluid provided for by the test rules, as well as filling the tank with the fluid to the level set by the test rules indirectly by the pumping unit, wherein the stand is equipped with a meter and an indicator of the volume of fluid contained in the tank.

EFFECT: provided various acoustic tests of any electro-hydraulic apparatus built into the tanks of vehicles.

1 cl, 1 dwg

Description

The invention relates to means for providing laboratory studies of acoustic noise of electro-hydraulic units (devices) built into vehicles hydraulic fluid tanks, in particular, for studies of fuel pumps with electric drive integrated with fuel tanks of vehicles, which are a characteristic "small", but brightly distinguished source noise and vibration in the passenger compartment of the vehicle.

Improving the acoustic comfort in the passenger compartment is one of the important tasks of vehicle manufacturers, which requires large material, time and intellectual resources. Experimental studies carried out in bench / laboratory conditions and with the involvement of a variety of techniques for simulating operating modes are diverse and highly productive processes that ensure the refinement of the vibroacoustic parameters of vehicles and their individual components, at least to regulated levels.

For better reproducibility of test results, as well as in cases where acoustic studies are carried out using measuring microphones (receiver of signals of dynamic responses of the objects under study), and especially in cases of a low level of noise signal emitted directly by the test object (typical for small-sized electric motors and pumps), there is a need to ensure a low noise background and a minimum of distortion of the free acoustic field in the room where such studies are carried out. These conditions can best be ensured by conducting studies in a special acoustic anechoic chamber.

An anechoic (completely dampened) test chamber is an autonomous room, the internal enclosing surfaces of which are provided with a sound-absorbing coating, which is located on a vibration-isolated foundation, separated from the foundation of the main building. In an anechoic chamber, contextually necessary static and / or dynamic (with drive and / or load electric machines) stands can be and are placed.

One of the representatives of static stands used as part of an anechoic chamber is a stand for acoustic testing of small-sized mechanisms and systems equipped with a drive motor, according to patent RU 40795, IPC G01M 17/00, publ. 01/19/2004, containing recording and analyzing equipment located outside the anechoic chamber, a power source for an electric motor with a voltage level regulator, an elastic (elastic) suspension located in the anechoic chamber, measuring microphones and a frame that includes racks equipped with supports, as well as fixedly connected to racks, with the formation of a parallelepiped, runs located on the side of the supports, and crossbars located on the side of the ends of the racks remote from the supports. Where each of the supports of the racks is made with the possibility of fastening, using an elastic vibration-isolating substrate, to the floor of the anechoic chamber, an elastic suspension with the possibility of fastening on the frame crossbars and with the possibility of holding the research object in the space between the frame elements. At the same time, racks, girders and beams of the frame are made of plugged pipes, the cavities of which are filled with loose and/or foamed vibration-damping substance, and the outer surface of the frame is lined with a sound-absorbing coating, the reverberation sound absorption coefficient of which is not lower than 0.8 in the frequency range from 500 to 8000 Hz.

In the solution according to patent RU 40795, the suspension is made in the form of elastic / elastic strands located on the side of the object under study, the ends of which are equipped with easily removable S-shaped hooks. In the description of this solution, it is indicated that the stand kit includes a set of hooks of various sizes, situationally used depending on the geometric parameters of the research object, and a variant of the stand for the research process of an electrically driven fuel pump is illustrated, which is installed in a tank (hereinafter referred to as the tank), suspended, for the test period, on strands in the space between the frame elements, and filled with a fuel simulator (a dielectric, flame-retardant liquid, the viscosity of which is close to the viscosity of the medium normally pumped by the pump). At the same time, the preamble of the description indicates the possibility of using the stand for research, including electric washer fluid pumps. To designate the medium normally pumped by the pump of an electrohydraulic device, or its simulator, the term liquid is further used.

Known from the prior art:

- that electro-hydraulic devices (in relation to vehicles - pumps driven by an electric motor) are generators of elastic oscillations caused by the vibration of the mechanical elements of the pump and the pulsation of the medium pumped by the pump, the vibration of the moving elements of the electric motor, the dynamic forces arising in its windings, as well as those arising in the magnetic the electric motor system by magnetostrictive and electromagnetic forces, the amplitudes of which depend, among other things, on the magnitude of the supply voltage, and on the presence and level of high-frequency electrical interference wandering in the electrical network supplying the electric motor.

- that the walls of the tanks are vibro-excitable, structurally related to electro-hydraulic devices, structural elements of vehicles; that the tank can increase the sound level of the source (mainly in the region of low-frequency harmonics) both by increasing the sound radiation surface and by resonating the tank walls (depending, among other things, on the degree of tank filling); that the amplitude of vibration displacements depends, among other things, on the degree of filling of the tank, and on the design features of the tank, and on the distribution of mechanical stresses in the walls of the tank obtained during its manufacture.

It follows from the above note that it is advisable to perform acoustic studies of electro-hydraulic devices as part of tanks with which electro-hydraulic devices must be integrated as part of the vehicle, as well as with different filling of tanks, at different, within acceptable limits, levels of voltage supplying the electro-hydraulic device and , as an option, using modes that simulate the presence of high-frequency electrical interference with specified parameters in the supply network of the electro-hydraulic device.

In the context of the proposed stand, and also based on the conditions that it is desirable to implement in the process of conducting research, the following disadvantages can be distinguished in the stand according to patent RU 40795:

- Lack of a pump for filling the tank with liquid pumped by the electro-hydraulic device to the level specified by the test regulations, as well as for complete or partial removal of the liquid from the tank at the end of the research stage specified by the regulations.

- Lack of a meter (sensor) and a pointer (indicator) of the liquid level in the tank.

- The need to manufacture and fix on the tanks, at the stages preceding the research, hooks, which, as a rule, are initially (normally) absent, made with the possibility of interacting with the suspension hooks.

- The need for individual, at the stages preceding the study, adjustment of the length of the strands and their location on the crossbars of the frame in the case of studies involving different types of tanks.

- The possibility of introducing distortions into the free acoustic field of an anechoic chamber by the suspension ties, due to the vibroexcitability of the ties, which depends on the physical properties of the material from which the ties are made, and on the length of the ties, and on the degree of tension of the ties, which, in turn, varies depending on on the degree of filling the tank.

From the patent DE 10220496, IPC B60P 7/08, B60R 7/00, B60R 21/06, publ. November 27, 2003, and patent RU 52588, IPC B60R 7/00, B60R 21/06, publ. 04/10/2006 devices for holding objects in the luggage compartment of a car are known, any of which contains a frame and a mesh product fixed to the frame. The frame of the device according to DE 10220496 is made rigid, and the frame according to patent RU 52588 is elastic. Mesh product in the solution according to DE 10220496 is made in the form of an elastic mesh fabric with different, in the transverse and longitudinal directions, elasticity (the method of forming the mesh fabric is not specified); the mesh product in the solution according to patent RU 52588 is made by knotted weaving of elastic threads, formed in conjunction with the frame, or with the formation of a net fabric, or with the formation of a net pocket / bag. At the same time, from the patent RU 2233921, IPC D04G 1/00, D04C 1/06, publ. 08/10/2004, a mesh product is known, see Fig. 6 description, formed in the form of a mesh bag, made by the method of knotless weaving.

Explanations for the terms used:

Net fabric is the structural material of most fishing gear, formed by mutually intersecting flexible threads fastened at their intersection points. Net fabrics are divided into knotted and knotless. Net fabrics with a ratio of thread diameter to mesh pitch of less than 0.02 are called a net and are used for grouping fishing gear, with a ratio of more than 0.02 - delyu and are used in screening fishing gear - see page 223 of the book "Marine Encyclopedic Reference Book", volume 2 (O-Ya), edited by N.N. Isanina, L. Shipbuilding, 1987.

Purse - incl. mesh shell for catching fish (see p. 296 of the book "Explanatory Dictionary of the Russian Language", edited by S.I. Ozhegov, N.Yu. Shvedova, M. AZ 1995), or, incl., soft folding a basket, a wicker or knitted bag, a mesh bag (see p. 295 of the book “Explanatory Dictionary of the Living Great Russian Language”, V.I. Dal, volume 2 (I-O), M. “Astrel. AST” 2001, printed on the basis edition of 1955, which reproduced the 2nd edition of the dictionary of 1880-1882).

The objective of the proposed technical solution is to create a stand for acoustic testing of electro-hydraulic devices built into the tanks of vehicles. As a prototype, a decision was made on patent RU 40795.

The problem is solved in a bench for acoustic testing of electro-hydraulic devices built into the tanks of hydraulic fluids of vehicles, containing recording and analyzing equipment located outside the anechoic chamber, a power source with a voltage level regulator, a suspension located in the anechoic chamber, measuring microphones, and also made in the form a parallelepiped frame, including racks, girders and crossbars;

The problem is solved by:

- the suspension of the stand is made in the form of a net (mesh) purse, the mouth of which is fixedly fixed, with the possibility of dismantling, on the crossbars of the frame, and the del is formed with the possibility of holding in the space between the elements of the frame of various tanks from among those integrated into the vehicle with the investigated electro-hydraulic device,

- at the same time, the del purse is formed by intersecting shock-absorbing cords connected at the points of their intersection without the formation of knots,

- the stand is equipped with a transfer pump capable of filling the tank with liquid to the level specified by the test regulations, as well as for complete or partial removal of liquid from the tank at the end of the research stage specified by the regulations, and a storage of the pumped liquid, configured to store the liquid provided for by the test regulations, and also mediated by the transfer pump for supplying liquid to the tank and receiving liquid from the tank,

- the stand is made equipped with a meter and an indicator of the volume of liquid placed in the tank.

The invention is illustrated by a drawing (Fig. 1), illustrating the description of the proposed stand.

The positions in FIG. 1 shows:

1 - tank of the tested electro-hydraulic device.

2 - depreciation cords forming del purse (shown conditionally).

3 - investigated electro-hydraulic device; the drawing shows a variant of an electro-hydraulic device combined with a fuel level sensor.

4 - power source of the tested electro-hydraulic device, pointer and sensor (if any) of the fuel level; can be combined or additionally equipped with a voltage regulator and, as an option, a source of high-frequency electrical interference with the specified test schedule parameters. Transfer pump power supply not shown; it can be either a power source temporarily connected to the transfer pump for the electro-hydraulic device under test, or the electrical network of an anechoic chamber (not shown).

5 - transfer pump.

6 - fluid storage.

7 - indicator of the volume of liquid placed in the tank.

8 - frame racks.

9 - crossbars of the frame (runs are not indicated by positions).

10 - transfer pump and fluid storage hoses.

11 - measuring microphones.

The invention can be implemented in a stand located in an anechoic chamber (not shown), containing measuring microphones 11, recording and analyzing equipment associated with microphones (not shown), power supply 4 with a voltage level regulator (not shown) and, as an option, with a source (not shown) high-frequency electrical interference with the specified, test schedule, parameters, suspension, meter and indicator 7 of the volume of liquid placed in the tank, frame, and transfer pump 5, storage 6 of the pumped liquid and hoses 10 of the transfer pump and storage of liquid.

Recording and analyzing equipment, indicator 7 of the volume of liquid placed in the tank (when using translucent tanks, it may be absent as a functionally independent device), power supply 4 with a voltage level regulator and, as an option, with a source of high-frequency electrical noise with specified parameters, are made placed behind outside the anechoic chamber.

The frame, the suspension, the measuring microphones 11, the volume meter of the liquid placed in the tank (when using translucent tanks, it may be absent in the form of a functionally independent device) are made placed in an anechoic chamber.

The frame is formed by 8 posts, girders (drawn, but not indicated by positions) and crossbars 9, fixedly connected to form a parallelepiped. Each of the racks 8 is provided with supports (drawn, but not indicated by positions), formed with the possibility of fastening, using an elastic vibration-isolating substrate (not shown), to the floor of an anechoic chamber (not shown). Racks 8, girders and crossbars 9 of the frame are made of plugged pipes, the cavities of which are filled with loose and/or foamed vibration damping substance. The outer surface of the frame is made lined with a sound-absorbing coating (not shown), the reverberation sound absorption coefficient of which is not lower than 0.8 in the frequency range from 500 to 8000 Hz.

The transfer pump 5, the storage 6 of the pumped liquid, as well as the hoses 10 of the transfer pump and the storage of the liquid are preferably mobile, introduced (brought in/brought in) into the anechoic chamber at the preparatory stages preceding the study. If the presence in the anechoic chamber of the transfer pump 5, the storage 6 of the pumped liquid and their hoses 10 is provided for by the test regulations for the electro-hydraulic device, then the outer surfaces of at least the transfer pump and the storage of the pumped liquid are provided with sound-absorbing lining, the reverberation coefficient of sound absorption of which is not lower than 0.8 in the frequency range from 500 to 8000 Hz.

The stand is made equipped, for the period of testing, with the investigated electro-hydraulic device 3 and the tank 1, from among those with which the investigated electro-hydraulic device 3 can be integrated into the vehicle.

The suspension of the stand is made in the form of a net (mesh) purse, the mouth of which is fixedly fixed (with the possibility of dismantling upon completion of all tests of the investigated electro-hydraulic device) on the crossbars 9 of the frame. Where del (shown by a dotted line) of the purse is formed with the possibility of holding in the space between the frame elements of any of the tanks 1, the use of which is provided for by the regulation (regulations) for testing the investigated electro-hydraulic devices. At the same time, the purse is formed by intersecting shock-absorbing cords 2, connected at their intersection points, without the formation of knots, similar to those that occur when knitting nets from a fishing line / thread / cord.

For studies of electro-hydraulic devices of cars, in the most preferred embodiment, del purse can be formed with cells ranging in size from 160 to 200 mm with cords 2 with shock-absorbing diameters of 8 or 10 mm according to TU 38 105572-2011, with fixation of cords 2 at their intersections , tightening by heat-treated, preferably galvanized low-carbon steel wire according to GOST 3282-74 (not shown).

Known from the prior art. That the tanks of vehicles can be made either from a material that does not transmit light, or light-transparent. Light-impervious tanks must be made equipped with a volume meter placed in the tank of liquid (the drawing conventionally shows a meter combined with the studied electro-hydraulic device 3 - the solution is also known from the prior art). When using light-transparent tanks, the role of the volume meter of the liquid placed in the tank and, accordingly, of the pointer 7, can be performed by the transparent walls of the tank. As a meter and indicator of the volume of liquid placed in the tank, any known from the prior art flow meter (counter for the amount of liquid pumped by the pump for filling / emptying the tank of liquid) can also be used with performance and error parameters corresponding to the test regulations, built into the hydraulic line of one of the hoses 10 of the pump 5 and storage 6 of the pumped liquid.

In the best case, as a volume meter placed in the tank, the liquid can be used either integrated with the tank (option not shown in the drawing), or integrated with the investigated electro-hydraulic device 3, a liquid level sensor from among those normally used as part of the vehicle to which the object under study belongs. an electrohydraulic device, and as a pointer 7 - an electrodynamic or digital pointer with parameters corresponding to the meter.

Storage 6, transfer pump 5 and tank 1 of electro-hydraulic device 3 under investigation can be made connected by means of hoses 10 either during the entire research cycle or with the possibility of connection at preparatory stages of research prior to testing. In this case, the transfer pump 5 can be made fixedly connected to the storage 6 of the liquid.

The principle of operation of the stand, in principle, is clear from the drawing and the description above.

Tank 1 with the tested electro-hydraulic device 3 is made freely (without additional fastening to the body) laid on the body of the purse, located in the space between the frame elements, filled with liquid in the volume required by the research regulations (up to the required level). Filling / emptying of the tank 1 is carried out by the transfer pump 5 using the storage 6 of the pumped liquid, the degree of filling of the tank 1 is controlled by the pointer 7 of the volume of the liquid placed in the tank or, alternatively, by changing the appearance of the tank, if the latter is made translucent. Measuring microphones 13 are located at a distance of 0.25 m from the outer surface of the walls of the tank 1. Microphones 13 are electrically connected to the recording and analyzing equipment. Power source 4, voltage regulator (not shown) and, as an option, a source (not shown) of high-frequency electrical interference with the specified, test regulations, parameters are made electrically connected to the investigated electro-hydraulic device 3, pointer 7 and sensor (if any) volume ( level) placed in the liquid tank. For the period of filling the tank 1 with liquid (emptying the tank 1), the transfer pump 5 is electrically connected to a power source (not shown), which, depending on the electric drive of the pump, can be used either as a power source 4 of the tested electro-hydraulic device 3, or an anechoic electrical network cameras (not shown).

The cells of the deli provide free access to the tank 1, the investigated electro-hydraulic device 3 and the liquid level sensor, the contextually necessary electrical wires and one of the hoses 10 of the transfer pump 5, and do not prevent the propagation of acoustic noise generated by the investigated electro-hydraulic device 3 into the space of the anechoic chamber.

Cushioning cord 2 according to TU 38 105572-2011 includes a strand of elastic (elastic), square section, threads and a sheath (braid), initially formed by weaving cotton or synthetic threads, or threads of mixed fibers around a pre-stretched strand. The presence in the strand of a number of braided elastic threads provides sufficiently high vibration-damping qualities of the cord.

Suspension in the form of a purse, the del of which is formed by mutually intersecting shock-absorbing cords 2, fixedly connected at their intersection points, provides:

- laying and holding tanks of a fairly wide range without any preparatory actions,

- crushing del forming cords into sections limited by the size of the cell, the length of each of which is less than the length of the elastic / elastic strands of the suspension of the prototype stand, which reduces the vibration excitability of the cords in the low-frequency range,

- mutual damping by sections of the cords converging in each of the places of fixation of the cells, vibrations excited by the work of the electro-hydraulic device under study, on the sections of the cords forming the cells.

Knotless del, the cells of which are made fixed by binding by means of a thin steel wire, is characterized by a small surface area of any of the junctions of intersecting cords and, as a result, their low sound-reflecting ability, which minimizes the distortions introduced by the delju into the free acoustic field of the anechoic chamber room.

The stand provides acoustic tests, in all their diversity, of any electro-hydraulic devices built into the tanks of vehicles.

Claims (1)

Stand for acoustic testing of electro-hydraulic devices built into the tanks of hydraulic fluids of vehicles, containing recording and analyzing equipment located outside the anechoic chamber, a power source with a voltage level regulator, a suspension located in the anechoic chamber, measuring microphones, as well as a frame made in the form of a parallelepiped, including racks, girders and crossbars, characterized in that the suspension is made in the form of a net purse, the mouth of which is fixedly fixed, with the possibility of dismantling, on the crossbars of the frame, and the del is formed with the possibility of holding in the space between the elements of the frame of various tanks from among those integrated into as part of a vehicle with an electro-hydraulic device under study, the purse is formed by intersecting shock-absorbing cords connected at their intersection points without forming knots, the stand is equipped with a transfer pump and storage of the pumped liquid, made with the possibility of storing the liquid provided for by the test regulations, as well as the liquid supply to the tank mediated by the transfer pump to the level specified by the test regulations and the liquid intake from the tank, while the stand is equipped with a meter and an indicator of the volume of liquid placed in the tank.

Images