RU2296979C1 - Device for measuring adhesion qualities of road cover and pneumatic wheel in zone of contact with varying speed of movement and specific pressures on surface - Google Patents

Abstract

FIELD: tool-making industry.

SUBSTANCE: device for measuring adhesion qualities of road cover contains supporting frame, imitator of tire with standard protector samples and their tightening weights, triggering mechanism. Supporting frame is made of telescopic sections entering one another with one central and two jointed swiveling side posts with possible fastening in T-like position. Posts contains extendible pins, holding the frame on the surface of road cover during measurements. Tire imitator and a set of flat tightening weights are combined in common body with water reservoir and dispensing mechanism for sprinkling it onto road cover. Spring engine for moving tire imitator is made with possible cocking thereof by manual drive through a reducer, is also equipped with controller of spring pre-tightness and variable-speed gear for movement speed and traction force of moving branch of pulley block. End of chain of moving branch of pulley block is held in variable-speed gear in accordance to required movement speed of tire imitator on road cover, determined by means of stopwatch with automatic enabling/disabling, performed simultaneously with start-stop of rotation of replaceable circular diagram of automatic recorder with dynamometer, built into immobile branch of pulley block and measuring the value of traction force.

EFFECT: possible measurement of forces of sliding friction and friction of rest in longitudinal and transverse directions of motorway road cover in tire contact zone.

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Description

The invention relates to technical means for ensuring the functioning of the transport complex: driver - car - road by monitoring each of the constituent elements by the established road safety standard. A significant number of accidents (traffic accidents) are associated with slippery surfaces of roads and streets, the quality of car tires, the design of braking devices and driving skills by car drivers.

The bodies of the State Automobile Inspection (STSI) and the forensic autotechnical examination, in the interests of finding out the reasons and the culprits, are obliged to make an instrumental measurement of the kof. clutch at the scene of an accident.

However, the SDA (Rules of the Road) regulates the standards for deceleration rates for vehicles of various weight categories only from the start speed of braking at 40 km / h, while modern rolling stock is highly dynamic and in the vast majority of cases of road accidents, braking occurs at a speed of 100-150 km / h or more.

The standards for the coupling qualities of roads, both newly built and in operation, govern the value of kof. traction along the road at a speed of not more than 60 km / h.

At the same kof. road adhesion in the transverse direction of the coating, which ensures the stability and controllability of cars when performing maneuvers on turns, turns, overtaking, etc., is not measured and not standardized at all, which does not provide road safety requirements.

According to the statistics of road accidents, 75-80% of their cases occur due to human factors - drivers. When driving, the most dangerous driving effect is the process of braking the car, especially at high speeds and in difficult road conditions: in rain, icing, contamination of the road surface with leaves, soil removal, snow cover, etc. Therefore, duplication and automation are provided in many vehicle designs the braking process by using the anti-lock braking system ABS, which ensures the braking process is optimized even by an inept driver.

The main function of the ABS is to exclude braking ″ use ″, i.e. sliding wheels on the road surface, the friction force of which is measured when determining kof. longitudinal coupling currently available devices. The length of the braking track ″ use ″ in an accident is the main artifact, the size and nature of which is intermittent, solid, etc. - the technical expertise determines the technical condition of the cars, the driving skills of the accomplices and the culprit of the accident. However, cars equipped with ABS (and from 01.01.2005, all cars must be produced with ABS) when it is in good condition, should not leave traces of “use” on the road when braking. The serviceability of the ABS can only be determined by measuring the magnitude of the friction of the rest forces in the contact of the tire and the road, the value of which is available for measuring the kof. road coating adhesion is not measured.

The lack of instruments for objective control of the actual values of kof. the clutch does not ensure the objectivity of all subsequent proceedings of the circumstances of an accident in identifying the culprit and the defendant for compensation for material damage, his administrative or criminal liability in accordance with the Law on Compulsory Insurance of all car owners that has already entered into force. Given the current number of car owners in the Russian Federation - over 24.5 million with an annual growth rate of 1.0 million over the past 7 years and 200-250 thousand traffic accidents annually, the waves of the auto tsunami will cover all legal institutions of the state in the near future.

As a prototype, the invention according to A.S. SU 1730327 A1 ″ Device for evaluating the adhesion of road surfaces ″.

Functional nodes of the prototype are inherent in a number of disadvantages that do not allow the measurement of kof. the clutch over the entire range of actual braking start speeds, since the possible speed of the tire simulator 5 with the load 13 is limited by the free fall speed of the composite load 8, not exceeding 9.8 m / s ² or 36 km / h.

In addition, the load 13 does not allow simulating the specific pressure on the friction samples in the tire simulator 5 in accordance with the actual load on each of the axles of the car (road train). The friction conditions in the tire simulator 5 are limited either by the dry surface of the road surface or previously wetted by preliminary irrigation from the irrigation machine, after which it is impossible to create real conditions and the thickness of the film of water on the surface during its wetting by the rain of rain, provoking the effect of aquaplaning - complete separation of the pneumatic wheel from the surface of the road.

The spatial structure of the support frame 1 in the form of a rigid triangle, in which the functional units of the prototype are located, do not satisfy the conditions of portability and the ability to measure at the smallest linear dimensions on the greatest possible extent of the road surface, especially in the cross section of the roadway, since the road surface is under the left and the right wheels of the car has (track of the roadway) different kof. adhesion under the influence of operating factors, which creates a difference in the forces of rolling resistance of the wheels, the occurrence of torque during braking, resulting in skidding of the car, its emissions into the oncoming lane, and other phenomena of loss of stability and controllability.

The result of the invention is the provision of the possibility of objective measurements of the actual values of the sliding and resting friction forces in the longitudinal and transverse directions of the road coating in the tire contact zone (specimens of its tread) in a wide range of speeds and specific loads (axial weight) that occur during operation land transport, especially automobiles, modeling of these forces under conditions of dry or dosed wetting of the road surface with an assessment of their compliance with the norm nym values of CFU-F. couplings from the Rules for the maintenance and operation of roads.

The goal is also the portable layout of the functional units of the measuring instrument, since the determination of the actual value of the kof. cohesion is a mandatory step in compiling a protocol on an accident event (and the Instruction on the performance of a forensic automotive technical examination prohibits the use of tabular data on the cohesion clutch at the scene of an accident, as well as judges are forbidden to take tabular data into account in litigation in an accident) use of the device by traffic police inspectors, commissioners of motor insurance companies, automotive technical experts, road foremen and technical maintenance services of highways, etc., fulfilling their uzhebnye function by moving the place of accident to the vehicle or motorcycle with sidecar.

The essence of the invention - these goals are achieved in that, to ensure portability, the support frame is made of telescopic sections sliding into one another with central and two hinged side racks with the possibility of mounting in a T-shaped position, the racks contain retractable spikes that secure the frame to the surface road surface when taking measurements.

To expand the range of speeds of the tire simulator on the road surface in accordance with the real speeds and start braking of modern highly dynamic cars, the friction specimen mover is spring-loaded with a preliminary adjustable spring preload in combination with a multi-stage variator of the drive torque and the linear speed of the tire simulator along the coating surface highways.

The plunger of the spring propulsion is carried out by a manual drive through a gearbox and a controlled coupling-disconnect it from the drive, which ensures independence from other sources of energy except for the muscular efforts of the measurement performer.

Real specific loads in the contact zone of the simulator with the road coating are created by a set of weights for the load, depending on the axial loads of the means of transport and the air pressure in the tires, combined in one unit with a water tank and the dosed irrigation mechanism of the friction zone of the tire simulator along the road surface, which allows modeling water film on the coating, depending on the intensity of the rain during the accident.

The potential traction force accumulated by the spring mover when it is cocked is recorded on a removable paper chart after 5 or 10 kG using a dynamometer integrated with the recorder and integrated into the stationary chain-link chain, while the chart's mounting disk is integrated into the mobile chain-link chain and starts to rotate simultaneously with the beginning of the movement of the tire simulator on the road surface.

With this movement, part of the thrust force of the propulsion device is spent on overcoming the friction forces in the contact zone of the tire simulator and the road cover, which is recorded by the recorder on a paper chart.

Simultaneously with the rotation of the chart recorder, the stopwatch automatically turns on, which fixes the time the tire simulator moves across the coating and turns on when it stops, which allows you to determine the actual speed of the simulator in km / h.

In the operating state, the meter frame is fixed on the coating area where measurements are made using retractable pins located inside the frame support posts in its transport position, which excludes the possibility of movement under the influence of reactive forces and ensures the identity of multiple measurements to obtain an average value.

Structurally, "Meter ..." contains the following components and parts:

Figure 1 is a main view of the meter;

Figure 2 is a top view - "-;

Figure 3 - view of the regulator preload spring propulsion;

where including:

1 - road coverage area;

2 - bus simulator;

3 - spike of fixing the meter frame on the road surface;

4 - a pedal of descent of a tire simulator;

5 - retractable central rack frame;

6 - pin stud fixing the meter frame;

7 - block tackle with bracket mounting it to the rack:

8 - the inner core of the spring propulsion;

9 - screw-in headband of the spring preload regulator;

10 - threaded part of the outer housing of the spring propulsion;

11 - clamp-clamp of the first sliding section of the frame;

12 - - ″ - the second - ″ - - ″ -;

13 - variable along the length of the mobile branch of the chain hoist;

14 - a variator of the speed of movement and traction force of the moving branch of the pulley block;

15 - elements of the sliding sections of the frame;

16 - mobile branch of the pulley block;

17 - disc compensator for the length of the movable chain hoist with a removable (paper) chart of the recorder;

18 - stopwatch;

19 - dynamometer with a recorder;

20 - a folding rack of a frame;

21 - the trigger trigger simulator tires;

22 - a handle for carrying a tire simulator with weights;

23 - tire simulator housing;

24 - regulator of the moistening mode of the friction surface zone on the road;

25 - reservoir of water supply;

26 - steel tape platoon spring propulsion;

27 - fixed block - "- -" - - "-;

28 - the outer housing of the spring propulsion;

29 - an arm of fastening of the motionless block of the spring mover;

30 - loop fastening hinged frame rack;

31 - traverse for mounting nodes and parts;

32 - fixed branch of the pulley block;

33 - mounting cross member hinged rack;

34 - spring;

35 - movable block tape platoon spring propulsion;

36 - block shock absorber;

37 - reducer platoon spring propulsion;

38 - gear drive handle with shaft;

39 - bracket mounting the handle;

40 - coupling;

41 - a pulley of a winding tape of a spring propulsion device;

42 - flat kettlebell weights of a tire simulator.

Operation of the meter - in the transport position, the meter is transported in the trunk of any car or motorcycle stroller, since it consists of two places: a frame with functional units fixed to it and a tire simulator block consisting of a body 23 and a set of flat weights 42 in it. The meter is placed on the surface of the road surface, on which it is necessary to measure the kof. clutch and depending on its type: longitudinal or transverse, the meter frame is oriented along the road surface or across the track lane.

The retractable stand 5 extends to the required length of the measurement zone and is fixed in this position by the clamps of sections 11 and 12. The hinged racks of the frame 20 are pushed to the sides, forming the letter T, and in this position they are automatically locked with special cuts in loops. Using a metal extension and a hammer, with a few strokes on the head end of the pins 6, the spikes 3 are driven into the asphalt concrete coating, fixing the position of the frame from possible displacements when exposed to reactive forces. In the case of measurements on a cobblestone pavement or cement concrete slabs, the spikes are clogged between the cobblestones or slabs, and for reliable fixation, it is sufficient to fix the frame with two spikes in any combination thereof. Then, a tire simulator is taken by the handle 22, the casing of which 23 has a U-shaped tunnel below the entire length, the width of which is slightly larger than the cross section of the thickest section of the frame. At the same time, spring-loaded obturators inside the tunnel record the simulator equally spaced in the initial position on the thinnest section of the frame, and the vertical height of the U-shaped tunnel in the body is slightly higher than the height of all the lower pipes of the frame sections in its working position - all fixing pins are clogged into the road surface , which ensures unhindered support of the tire simulator with fixed tread patterns only on the road surface.

The tire simulator is installed with a U-shaped tunnel on the thinnest section of the lower part of the frame 15 and is supported by the tread patterns of the tire 2 on the covering of the road 1, then, by moving to the rack 5, the hook 21 of the housing 23 is engaged with the hook of the pedal descent 4.

Excessive weights are removed from the housing 23 (according to the measurement conditions, according to the required specific gravity in kg / cm ² according to the available area of the tire tread), the remaining weights should be the same in the left and right pockets of the housing 23. Then the moistening mode dial 24 ( opening automatically with the beginning of the movement of the tread specimens) is set to the position required by the measurement task (the height of the water film in the rain of a certain intensity according to the help of the weather service at accidents accident) and in the reservoir of the reserve 25 pour water from a transportable container (canister).

The stocking of a flexible working body, made in the form of a small chain of oblong twisted or cylindrical links of circular cross-section, is performed starting from the fixing of the fixed branch of the chain block 32 to the movable element of the dynamometer 19, on the second end of which is also movable, a writing device in the form of a holder of a felt-tip pen or a speedograph is fixed (ball ampoules do not provide reliability of fixation), replaced with other colors for clarity of multiple measurements in the same place (usually at least three).

The movable chain block 16 is stored in blocks 7 in accordance with the arrows in FIGS. 1-2 or the diagram in the operating instructions, and the variable-length branch 13 is fixed in the corresponding stream of the variator 14 according to the required speed of the tire immitator along the road surface 1. After making sure that the clutch 40 is in the "on" position and connects the variator pulley 14 to the gearbox 37, by rotating the cocking spring 38, the propeller is brought into working position, accumulating potential energy. The value of this energy is controlled by the readings of the dynamometer 19 and the mark marks on the removable paper chart of the recorder 17 after 5 or 10 kG.

When energy is accumulated, the value of which corresponds to the weight of the set of weights 42 in the tire simulator 23, the further spring charging 34 is stopped. If the weight of the set of weights exceeds the energy of a fully cocked spring 34, use a device for its preliminary compression by screwing the headband 9 into the threaded part 10 of the outer casing of the spring propulsion 28.

The operation of the spring propeller is based on reducing the length of the steel (or composite) tape, the branches of which are located on both sides of the spring 34, located inside its outer case 28 along its entire height to the threaded part 10. One of the ends is fixed to the body below the threaded part in a special slot the tape, and the middle part of it in the uncovered state of the spring 34 is supported by a movable rotating block 35, which is fixed in the slots of the stop of the inner rod 8, on which the lower part of the spring 34 is supported. The second end of the tape through a rotating, but the fixed block 27 and is secured to the pulley 41 of the variator 14. When the cocking handle 38 rotates the gear 37 and the tape is wound on the pulley 41, its length is reduced and the resulting reactive force compresses the spring 34, accumulating the potential energy of compression.

After making sure that all the preparatory operations are carried out in accordance with the instructions and in the working area of the meter on the road surface there are no foreign objects or limbs serving people, the operator puts the clutch 40 into the "disconnected" position, after which the force of the final energy value of the charged spring 34 of the drive branch 13, 16 and 32 are pulled, and moving and rotating nodes and parts are held alone only by a hook 21.

When the operator presses the release pedal 4, the hook 21 is released, the spring 34 is opened and acts on the belt 26 through its block 8 through the block 35. Since one end of the tape is fixed to the housing of the mover 28 motionless, and the second through the rotating block (but fixed motionless) is connected to the pulley the variator 41, then the force of the spring to press down through its inner rod 8 with a rotating and movable block 35 will unwind the previously wound tape and rotate the variator 14.

Since in one of the streams of the variator 14 the end of the chain of the moving branch 13 of the tackle is fixed, the latter will be wound along the stream and move the case 23 of the tire simulator with the weights of the load 42 along the surface of the road surface. At the same time, the reactive force of movement of the simulator along the road surface through the stationary branch of the pulley block 32, in which the dynamometer with the recorder 19 is structurally included, will be fixed on the paper diagram 17.

To obtain a weighted average value of the resting friction forces and the friction forces of the tire simulator on the road surface at the scene of an accident, the measurements are performed three times, without changing the position of the meter on the road, and on the same paper chart, but changing the colors of the recorder’s felt-tip pens for clarity measurement results.

Values of actual kof. adhesion is obtained by subsequent calculations from the ratio of average values of traction forces recorded by the recorder to the value of the total weight of weights in the tire simulator and its own weight, i.e. the pressing force of the tire simulator to the surface of the road surface.

Claims (1)

A grip indicator of the road surface containing a support frame, a tire simulator with tread patterns and their weight, a trigger mechanism, characterized in that the support frame is made of telescopic sections that slide into one another with central and two hinged side racks with the possibility of mounting in T-shaped, the racks contain retractable spikes that secure the frame to the surface of the road surface when taking measurements, a tire simulator and a set of flat weight weights are combined with a reservoir aroma for water and a dispenser for draining it onto the road surface, a spring mover for moving the tire simulator is made with the possibility of cocking it manually with a gearbox, equipped with a spring preload regulator and a variator of the movement speed and traction force of the moving chain hoist branch, the chain end of which is fixed in the variator according to the required speed of the tire simulator on the road surface, determined using a stopwatch with automatic on-off, carried out simultaneously with the beginning ohm-end rotation replaceable circular chart recorder with a dynamometer mounted into a fixed branch chain hoist and traction measurand.

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