A device for measuring maximum slope parking braking force of a mine trackless rubber-tyred vehicle

Abstract

This utility model discloses a device for measuring the maximum braking force of a trackless rubber-tired mining vehicle on a slope, including a tension sensor, a measuring platform, and a drive system. The measuring platform comprises a flat plate, longitudinal beams, transverse beams, vertical beams, and an inclined beam. The flat plate, longitudinal beams, and transverse beams are fixedly connected; the vertical beams are fixedly connected to the longitudinal beams, adjacent vertical beams are fixedly connected via transverse beams, and the inclined beams are fixedly connected to the longitudinal and vertical beams to improve the connection strength between the vertical and longitudinal beams. One end of the platform is hinged to a column. A drive system is located beneath the platform, comprising a hydraulic cylinder, a motor, a pump, and an oil tank. One end of the plunger in the hydraulic cylinder is hinged to a support fixed to the ground, and the other end of the hydraulic cylinder is hinged to the underside of the longitudinal beams. The motor, pump, and oil tank are sequentially connected and fixed to the ground. By measuring the tilt angle of the platform, the maximum braking force of the vehicle on a slope is calculated, resulting in high measurement efficiency, high accuracy, and a small footprint.

Description

Technical Field

[0001] This utility model belongs to the field of measurement, specifically relating to the measurement of the mechanical performance of trackless rubber-tired mining vehicles. Background Technology

[0002] Maximum ramp braking force is a crucial performance indicator for ensuring the stable stopping of trackless rubber-tired vehicles in coal mine roadways. Special working conditions and harsh environments can easily damage the braking system of trackless rubber-tired vehicles, severely affecting their stable stopping in sloping roadways. Therefore, it is essential to test and ensure that the maximum ramp braking force of the trackless rubber-tired vehicle meets the requirements. Existing testing methods primarily involve using another vehicle with greater traction capacity to tow the vehicle under test, parked on a level test site. The two vehicles are connected by a tension sensor with a large measuring range. During the measurement process, the traction force of the towing vehicle is gradually increased until the vehicle under test begins to move. The measured value of the tension sensor between the two vehicles at this moment is recorded. Then, according to relevant coal industry standards, this value is compared with the vehicle's theoretical maximum ramp braking force to determine whether the vehicle's performance is up to standard. However, because the measurement is performed on a level site, the existing method does not directly measure the vehicle's maximum ramp braking force, thus relying on indirect evaluation. Furthermore, this method suffers from low measurement efficiency, low accuracy, and a large footprint. Summary of the Invention

[0003] The purpose of this invention is to provide a device for measuring the maximum braking force of a trackless rubber-tired mining vehicle on a slope. By measuring the tilt angle of the measuring platform, the maximum braking force of the vehicle on a slope can be calculated. The device has high measurement efficiency, high measurement accuracy, and occupies little measurement space.

[0004] The technical solution of this utility model is a measuring device for the maximum slope stopping braking force of a trackless rubber-tired mining vehicle, comprising a tension sensor, a measuring platform, and a drive system. The measuring platform includes a flat plate, longitudinal beams, transverse beams, vertical beams, and inclined beams. The flat plate, longitudinal beams, and transverse beams are fixedly connected. The vertical beams are fixedly connected to the longitudinal beams, and adjacent vertical beams are fixedly connected through transverse beams. The inclined beams are fixedly connected to the longitudinal beams and vertical beams to improve the connection strength between the vertical beams and the longitudinal beams. One end of the platform is hinged to a column. A drive system is provided under the platform, which includes a hydraulic cylinder, an electric motor, a pump, and an oil tank, as well as an electromagnetic reversing valve, a first overflow valve, and a second overflow valve. One end of the plunger in the hydraulic cylinder is hinged to a support fixed on the ground, and the other end of the hydraulic cylinder is hinged to the underside of the longitudinal beam. The electric motor, pump, and oil tank are sequentially connected and fixed to the ground.

[0005] Furthermore, a vehicle stopper is fixed on the flat plate to limit the position of the vehicle under test on the platform.

[0006] Furthermore, the tension sensor is equipped with strong hooks on both sides, one side of which is connected to the vehicle under test, and the other side is connected to the vertical beam.

[0007] Furthermore, the hydraulic cylinder is connected to a solenoid directional valve, which is also connected to the pump and a second relief valve. The other end of the second relief valve is connected to the oil tank, and one end of the first relief valve is connected to the pump, while the other end is connected to the oil tank. Furthermore, an angular displacement sensor is installed at the hinge between the platform and the column.

[0008] Furthermore, during measurement, after the vehicle under test drives onto the platform, a magnetic chuck needs to be placed behind the vehicle on the platform. The magnetic chuck adheres tightly to the flat plate to prevent the vehicle from sliding backward and to ensure that it does not come into contact with the rear wheels of the vehicle under test.

[0009] This utility model has the following advantages: The dedicated measuring device provided by this utility model eliminates the need for a specially added tractor with greater traction to complete the testing work. The range of the tension sensor used is much smaller than that of the tension sensors used in traditional measuring methods. In this device, the tension value measured by the tension sensor is simply the difference between the component of the vehicle's weight along the inclined plane of the platform and the static friction. During the measurement process, as one end of the measuring platform is gradually raised, the component of the weight along the inclined plane gradually increases. When this component equals the maximum hill-start braking force, the vehicle begins to slowly slide down the inclined plane of the platform. At this time, the tension on the tension sensor gradually increases. When the tension of the tension sensor reaches the threshold set by the measuring system, the measurement ends. This threshold is less than the maximum hill-start braking force of the vehicle. The maximum hill-start braking force of the vehicle can be calculated by measuring the tilt angle of the platform. This method has high measurement efficiency, high measurement accuracy, and occupies little measurement space. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram showing the platform tilting during the measurement process; Figure 3 yes Figure 2 View A from the middle platform section; Figure 4 yes Figure 2 View B of the middle platform section; The reference numerals are as follows: 1. Column; 2. Longitudinal beam; 3. Flat plate; 4. Magnetic chuck; 5. Vehicle under test; 6. Tension sensor; 7. Vertical beam; 8. Inclined beam; 9. Vehicle stopper; 10. Hydraulic cylinder; 11. Electromagnetic directional valve; 12. Plunger; 13. First overflow valve; 14. Oil tank; 15. Pump; 16. Motor; 17. Angular displacement sensor; 18. Crossbeam; 19. Support; 20. Second overflow valve. Detailed Implementation

[0011] like Figure 1As shown, a device for measuring the maximum braking force of a trackless rubber-tired mining vehicle on a ramp includes a measuring platform and a drive system. The measuring platform includes a flat plate 3, longitudinal beams 2, transverse beams 18, vertical beams 7, and inclined beams 8. The flat plate 3, longitudinal beams 2, and transverse beams 18 are fixedly connected. The vertical beams 7 are fixedly connected to the longitudinal beams 2, and adjacent vertical beams 7 are fixedly connected via transverse beams 18. The inclined beams 8 are fixedly connected to the longitudinal beams 2 and 7 to improve the connection strength between the vertical beams 7 and the longitudinal beams 2. One end of the platform is hinged to a column 1. A vehicle stopper 9 is fixedly connected to the flat plate 3 to limit the position of the vehicle under test on the platform. A force sensor 6 has strong hooks on both sides, one side connected to the vehicle under test 5, and the other side connected to the vertical beam 7. A drive system is located under the platform (all drive devices are installed on the road surface). At a certain depth, the drive system includes a hydraulic cylinder 10, a motor 16, a pump 15, an oil tank 14, an electromagnetic directional valve 11, a first relief valve 13, and a second relief valve 20. One end of the plunger 12 in the hydraulic cylinder 10 is hinged to a support 19 fixed on the ground, and the other end of the hydraulic cylinder 10 is hinged to the underside of the longitudinal beam 2. The motor 16, pump 15, and oil tank 14 are connected in sequence and fixed on the ground. The hydraulic cylinder 10 is connected to the electromagnetic directional valve 11, which is also connected to the pump 15 and the second relief valve 20. The other end of the second relief valve 20 is connected to the oil tank 14. One end of the first relief valve 13 is connected to the pump 15, and the other end is connected to the oil tank 14. An angular displacement sensor 17 is installed at the hinge between the platform and the column 1.

[0012] Before measurement, the platform is in a horizontal position. After the vehicle to be tested 5 drives from the road onto the platform, the operator places the magnetic suction cup 4 behind the vehicle to be tested 5 to prevent the vehicle to be tested from sliding backward a large distance along the slope. The magnetic suction cup 4 is tightly attracted to the plate 3 by magnetic force. The slope of the magnetic suction cup 4 is kept 1cm-2cm away from the rear wheel and does not contact the rear wheel of the vehicle to be tested 5.

[0013] like Figure 2As shown, at the start of the measurement, the motor 16 is first turned on, driving the pump 15 to run. Then, the valve core of the solenoid directional valve 11 is controlled to be in the left position, connecting the oil circuit between the pump 15 and the hydraulic cylinder 10. The pump 15 injects hydraulic oil from the oil tank 14 into the hydraulic cylinder 10, thereby driving the plunger 12 to extend. The platform supporting the vehicle gradually rotates around the hinge point between the platform and the column 1, and the platform supporting the vehicle gradually tilts, with the tilt angle gradually increasing. The component of the weight of the vehicle under test 5 along the inclined plane gradually increases. When the tilt angle of the platform is small, the weight of the vehicle under test 5 and the column 1 gradually increase. The friction between the plates 3 is balanced by the component of the weight of the vehicle under test 5 along the inclined plane of the platform, allowing the vehicle under test 5 to remain stationary on the platform. As the plunger 12 gradually extends, the inclination angle of the platform gradually increases, and the component of the weight of the vehicle under test 5 along the inclined plane of the platform gradually increases accordingly. When this component equals the maximum static friction of the vehicle under test 5, the vehicle under test 5 begins to slide downwards along the inclined plane of the platform, and the tension acting on the tension sensor 6 begins to gradually increase. To adapt to the actual engineering measurement, the measurement system pre-sets the tension threshold of the tension sensor 6 to [value missing]. F 0; when the force applied to the tension sensor 6 reaches the threshold. F At 0, the valve core of the control solenoid directional valve 11 is in the neutral position, the plunger 12 stops extending, the platform stops lifting, and the measured value of the angular displacement sensor 17 is read. After the reading is completed, the valve core of the control solenoid directional valve 11 is in the right position, the hydraulic oil in the hydraulic cylinder 10 returns to the oil tank 14 through the second relief valve 20, the plunger 12 retracts, the platform returns to the horizontal position, and the motor 16 is turned off.

[0014] The maximum braking force for hill-start assist measured by this method is:

[0015] In the formula, m For the mass of the vehicle under test, g It is the acceleration due to gravity. α This represents the maximum tilt angle of the platform as measured.

Claims

1. A device for measuring the maximum braking force when stopping on a gradient for a trackless rubber-tired mining vehicle, characterized in that, The system includes a tension sensor (6), a measuring platform, and a drive system. The measuring platform includes a flat plate (3), a longitudinal beam (2), a transverse beam (18), a vertical beam (7), and an inclined beam (8). The flat plate (3), longitudinal beam (2), and transverse beam (18) are fixedly connected. The vertical beam (7) is fixedly connected to the longitudinal beam (2), and adjacent vertical beams (7) are fixedly connected through the transverse beam (18). The inclined beam (8) is fixedly connected to the longitudinal beam (2) and the vertical beam (7) to improve the connection strength between the vertical beam (7) and the longitudinal beam (2). One end of the platform is connected to a column. (1) Hinged; A drive system is provided under the platform, which includes a hydraulic cylinder (10), an electric motor (16), a pump (15) and an oil tank (14), as well as an electromagnetic reversing valve (11), a first relief valve (13) and a second relief valve (20); one end of the plunger (12) in the hydraulic cylinder (10) is hinged to a support (19) fixed on the ground, and the other end of the hydraulic cylinder (10) is hinged to the underside of the longitudinal beam (2). The electric motor (16), the pump (15) and the oil tank (14) are connected in sequence and fixed on the ground.

2. The maximum slope stopping braking force measuring device for trackless rubber-tired mining vehicles as described in claim 1, characterized in that, A vehicle stopper (9) is fixed on the flat plate (3) to limit the position of the vehicle under test (5) on the platform.

3. The maximum slope stopping braking force measuring device for trackless rubber-tired mining vehicles as described in claim 1, characterized in that, The tension sensor (6) has strong hooks on both sides, one side is connected to the vehicle to be tested (5), and the other side is connected to the vertical beam (7).

4. The maximum slope stopping braking force measuring device for trackless rubber-tired mining vehicles as described in claim 1, characterized in that, The hydraulic cylinder (10) is connected to the solenoid directional valve (11), which is simultaneously connected to the pump (15) and the second relief valve (20). The other end of the second relief valve (20) is connected to the oil tank (14). One end of the first relief valve (13) is connected to the pump (15), and the other end is connected to the oil tank (14).

5. The maximum slope stopping braking force measuring device for trackless rubber-tired mining vehicles as described in claim 1, characterized in that, An angular displacement sensor (17) is provided at the hinge between the platform and the column (1).

6. The maximum gradient stopping braking force measuring device for trackless rubber-tired mining vehicles as described in claim 1, characterized in that, During measurement, after the vehicle under test (5) drives onto the platform, the magnetic chuck (4) needs to be placed on the platform. The magnetic chuck (4) is tightly attracted to the flat plate (3) by magnetic force to prevent the vehicle under test from sliding backward. The magnetic chuck (4) does not contact the rear wheel of the vehicle under test.

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