RU28772U1 - Dynamic research bench with running drums - Google Patents

Description

DYNAMIC RESEARCH STAND WITH RUNNING

The utility model relates to devices used in the technique of experimental design work (R&D) during the research and development of wheeled vehicles, in particular automobiles.

During bench tests for the study of noise, as well as in determining the power and economic characteristics of a car in a semi-anechoic acoustic chamber on a dynamic bench with running drums, a special car fastening system is used to keep the car from its spatial movements (hereinafter the fastening system). Known fastening systems are, in particular, a set of holding flexible cables with a tension mechanism in the form of four electric winches installed under the camera floor in the engine room of the test chamber. A car mounted on a dynamic stand, in this case, is fixed by cables to towing hooks (eyes, hooks). Cables, performing the function of tensioning elements, are installed on the drums of the winches through the original mounting racks and the swivel plates of the stand winches mounted on the floor. Known applied vehicle fastening systems and methods for mounting a car on a stand do not ensure the safety of the test process in the event of spontaneous weakening of the tensile force (or break) of one of the fastening cables at high speeds of rotation of the drums (simulating a high speed of a car). When one of the fastening cables loosens (breaks), lateral withdrawal of the vehicle immediately occurs, which can lead to a loss of stability of the test object on the running drums of the stand and, as a result, to damage both the vehicle itself and the expensive equipment of the dynamic stand. In addition, this problem is associated with safe working conditions for operators.

DRUMS.

involved in the process of testing a car. An operator located in the vehicle’s interior, in the event of an emergency in the form of a weakening (break) of the mounting cable, is not insured against injury.

From the application DE No. 19916699 A1, IPC G01M 17/00, publ. 30.112000, the applicant f. AUDI AG is a known holding device for bench tests of cars on running drums, which provides for a fixed position of the car on running drums, eliminating both longitudinal and lateral displacements, which is achieved through the use of rigid longitudinal and transverse couplers containing threaded adjusting inserts, rods with screw part and locking units with swivel joints. The hinge thrust housings are rigidly mounted in the floor structure of the test room in which the stand is located. The disadvantage of this design is the use of rigid (without compliant elastic and damping elements) restrictive connections between the vibrating body (body) of the car and the chamber floor, distorting the vibro-acoustic characteristics of the body, which is undesirable for their use in acoustic semi-anechoic test chambers. In this case, the dynamic excitation (vibration) from the power frame of the body, the elements of the car’s undercarriage is transmitted from the towing hooks through the vibroconductive elements of the restrictive fixing connections to the camera floor, causing its dynamic excitation (vibration) and the corresponding spurious noise radiation, distorting the real acoustic field of the investigated object (car). On the other hand, the imposition of rigid force-limiting constraints and their effect on the power frame of the body changes the real vibro-acoustic characteristics of the body, which is undesirable when conducting high-quality vibro-acoustic studies of a car in an acoustic chamber equipped with running drums. In addition, the absence of flexible damping links in the structure of restrictive bonds does not allow for the following compensating maintenance of a constant effort to keep the car on the bench (tracking reaction) at unsteady test modes (acceleration, braking) of the car, which often leads to additional impulse loads, as on the test vehicle, as well as on the elements of the vehicle mounting device on the stand, which is ultimately associated with a change in the vibro-acoustic characteristics of the test The object (car).

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in US patent No. 3520180, IPC G01M 7/00, 17/04, publ. 07/14/1970, a system for fastening a car to a dynamic stand with running drums is described, containing, in particular, six racks with electric winches kinematically connected via flexible elements (cable extensions) to the car body. Racks designed to exclude the vertical component of the power load from the fastening system due to the horizontal installation of the branches of the fasteners (cables) that close the vertical blocks with towing hooks of the car (one rack located at the front and rear of the car) and to eliminate the cross-section of the car in two pairs racks - located to the right and left of the car body in the areas of the front and rear bumpers, designed to exclude lateral removal of the car. The latter are located in the areas of the planes of the front and rear bumpers of the car, i.e. in areas of direct direct sound emission by tires, the engine compartment and the exhaust pipe cut (in the planes of the bumpers). This creates additional sound-reflecting effects from the massive surfaces of the racks and distortion of the real sound field of a moving car on a motorway, which is undesirable for high-quality objective measurements of the external and internal noise of the car in an acoustic semi-anechoic chamber with running drums on which the car under study is installed. On the other hand, such a system for fastening a car to a drum stand requires the use of a large number of links for adjusting the cable tension - six electric winch with the corresponding brake devices.

As a prototype, the system of fastening a car on a dynamic stand with running drums, described in the utility model certificate of the Russian Federation No. 23503, was adopted. A known system for mounting a car on a dynamic stand with running drums, comprising a vehicle mounted on running drums, equipped with towing hooks front and rear, the spatial movement of which is limited by holding flexible elements fixed in mounting devices mounted on the floor of the stand made in the form of two pairs of fixed vertical rotary racks located in pairs relative to the front and rear parts of the car body, and one pair of movable in the direction of the axis of the car racks; fixed vertical rotary racks are equipped with blocks rotating in horizontally located axes, and

loct / e-f axes of the blocks are mounted with the possibility of selective sampling and fixing along the height of the rack; movable racks are mounted in front of the car, in groove rails, the distance between which exceeds the width of the car body, with the possibility of selective installation and rigid fixation and are equipped with blocks rotating in the vertical axes, and the blocks have the ability to be fixedly moved along the height of the rack; branches of flexible elements are fixed in front and behind the car to a single towing hook; movable racks are located between the towing hook and the stationary racks, so that the branches of the flexible elements form an obtuse angle with the apex in the vertical axis of the movable rack block. The disadvantage of this car mounting system is the lack of safety restrictive elements that impede and prevent the further development of lateral withdrawal (lateral displacement) of the car in case of spontaneous weakening of the pulling force (or break) of one of the fastening cables at high speeds of rotation of the drums, which can lead to an emergency in the process of testing. In addition, the lack of protective deposition in the area of rotating running drums adversely affects the safety of working conditions of the stand operators, increases the risk of accidental access of the tester to rotating surfaces, which is unacceptable from the point of view of labor protection.

The essence of the utility model is that the well-known dynamic stand with running drums, containing a car mounted on running drums, equipped with towing hooks front and rear, the spatial movement of which is limited by holding flexible stand elements fixed in fixing devices mounted on the stand floor, is additionally equipped with a protective a device made in the form of a rigid sound-transparent mesh deposition, mounted with the possibility of targeted movement positioning and fixing opposite to the rotating wheels of the car depending on its specific base, while the protective device contains a thrust limiter roller that purposefully moves and locks in the required position depending on the track of the tested car, and prevents the development of lateral drive-off of the car (lateral displacement) spontaneous weakening of the tension (break) of one of the cables. The named mesh fence is located opposite the axes of rotation, along

fjX) Uf-f C of at least one of the steered wheels of the test vehicle. Mesh fences are placed in special grooved guides made on both sides of the car. Mesh fences are made in the form of rigid mesh structures (for example, from a wire with a diameter of 1.5 ... 3 mm), with the ability to move and lock in the required position depending on the vehicle base, interlocked in a single protective modules with persistent restrictive rollers, freely rotating on rigidly axles fixed to the base of the rollers, moreover, the base of the rollers are mounted together with mesh fencing with the help of groove fastening systems that allow selective selection and fixation of the position of the thrust limiting roller, depending on the test track car. The essence of the utility model is illustrated in the drawings.

In FIG. 1 shows the inventive dynamic research stand with running drums with a test vehicle mounted on it (top view).

Figure 2 shows a side view of a car mounted on the inventive dynamic stand with running drums.

The positions in Fig 1-2 are indicated:

1- semi-anechoic acoustic chamber;

2- sound-absorbing backstage of the acoustic chamber;

3- cable holding flexible elements of the stand;

4- test vehicle;

5-running stand drums;

6- guiding elements of the stand for mounting an additional protective device of the stand;

7 - additional protective device of the stand;

8-thrust restrictive roller of the protective device of the stand;

13 - the base of the mesh deposition of the protective device of the stand;

14 - mesh fence protective device stand.

On Fig 3 presents a fragment of the design of a dynamic stand with running drums, illustrating the essence of the utility model. The stop limiter roller 8, made of a metal material, for example, stainless steel and freely rotating on its axis 9 by means of two radial ball bearings 10 (for example, 6304-2RS1 and 6205-2RS1). The axis 9 is rigidly fixed to the locking support 11 by a welding seam. Retainer 11

has special grooves 12 for the fixed movement and fastening of the locking support 11 to the base 13 of the mesh fence 14 with the help of clamping bolts 15. Thanks to the groove system of fastening the stop restrictive rollers, the latter have the ability to move and lock in the desired position at a predetermined certain distance from the wheel (tire) depending on the track of the vehicle under investigation. In turn, the base 13 mesh deposition 14 is attached to the standard universal guides of the stand 6 (see Fig. 1), which allows you to move the protective fence 7 along the car, i.e. vary your location depending on the base of the investigated object. The mesh protective fence of the stand 14 is made, for example, of a thin steel bar with a diameter of 1.5 ... 3 mm, in the form of a rigid sound-transparent mesh structure, which, thus, allows not only to perform a protective (safety) function, but also to exclude the presence in the measurement zones acoustic

cameras of additional sound-reflecting surfaces that distort the real sound field of the studied object (car), in particular in the area of noise emissions by tires.

Persistent nachitelny rollers of the protective device of the stand are installed directly opposite the axis of rotation of each at least the front (driving, driven) wheel of the vehicle being used. When the tensile force of one of the fixing cables, for example, is weakened, and as a result of the lateral withdrawal of the car from the rotating surfaces of the running drums, the side surface of the wheel tire comes into contact with a thrust limiter roller that limits lateral displacement and which, due to the contact reaction with the sidewall of the rotating tire rotating on its rigidly mounted axis, it frustrates the further displacement of the car on the running drums and excludes the further process of driving the car.

The proposed dynamic research bench with running drums allows you to limit the lateral withdrawal of the vehicle, prevent accidental operator access to the rotating running drums, and thus significantly increase the safety level of the vehicle test process on a dynamic bench.

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Claims (1)

A dynamic research stand with running drums, comprising a vehicle mounted on running drums, equipped with towing hooks at the front and rear, the spatial movement of which is limited by retaining flexible elements fixed in fixing devices mounted on the floor of the stand, characterized in that the stand is additionally equipped with protective guards placed in special grooved guides, at least opposite to the axis of rotation of each steered wheel of the test vehicle, At the same time, the protective guards are made in the form of rigid mesh structures interlocked into single protective modules with stop restrictive rollers freely rotating on axes rigidly fixed to the base of the rollers, and the roller bases being mounted together with the mesh guards using grooved mounting systems with the possibility of movement and fixing in the required position depending on the track of the car.