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CN-121977852-A - Complete machine heat balance test method, medium and equipment for hydrostatic transmission engineering equipment

CN121977852ACN 121977852 ACN121977852 ACN 121977852ACN-121977852-A

Abstract

The invention relates to the technical field of engineering machinery, in particular to a complete machine heat balance test method, medium and equipment of hydrostatic transmission engineering equipment, wherein the method comprises the following steps of configuring a test vehicle, wherein a power transmission chain of the test vehicle comprises an engine, a hydraulic pump, a hydraulic pipeline, a control valve group, an electric control variable hydraulic motor, a controller, a speed reducer, an axle and wheels; when in a heat balance test, the vehicle accelerator is controlled to enable the engine to be kept at a rated rotation speed or a maximum torque rotation speed, the controller receives signals in real time, automatically calculates the required motor displacement by combining preset parameters such as a test demand load rate and the like, and then sends corresponding motor displacement signals to the electric control variable hydraulic motor, so that the motor displacement can be fed back and adjusted in real time, and the engine load rate is always kept near a preset value to meet the load requirement of the heat balance test. The invention solves the technical problems of complex tooling, high cost, high operation difficulty and low safety of the traditional heat balance test method.

Inventors

  • ZHOU ZHIXI

Assignees

  • 中国铁建重工集团股份有限公司

Dates

Publication Date
20260505
Application Date
20260122

Claims (8)

  1. 1. The complete machine heat balance test method for the hydrostatic transmission engineering equipment is characterized by comprising the following steps of: The method comprises the steps that a test vehicle is configured, a power transmission chain of the test vehicle comprises an engine, a hydraulic pump, a hydraulic pipeline, a control valve group, an electric control variable hydraulic motor, a controller, a speed reducer, an axle and wheels, the engine is connected with the hydraulic pump, the hydraulic pump is connected with the electric control variable hydraulic motor through the hydraulic pipeline and the control valve group, the controller is connected between the engine and the electric control variable hydraulic motor, the electric control variable hydraulic motor is connected with the speed reducer, the speed reducer is connected with the axle through transmission of a transmission shaft, the wheels are fixed on the axle, and the test vehicle is further configured with a vehicle speed sensor, an acceleration sensor and a gradient sensor; The method comprises the steps of acquiring real-time rotating speed of an engine through a controller, calculating required working power of a hydraulic pump according to external characteristic power parameters corresponding to preset engine rotating speed and test required load rate, and then calculating working pressure of a hydraulic motor by combining hydraulic pump displacement and hydraulic system pressure drop; And during the heat balance test, the driver controls the throttle of the test vehicle to keep the engine at the rated speed or the maximum torque speed, and the controller sends a corresponding motor displacement signal to the electric control variable hydraulic motor according to the calculation result, so that the load factor of the engine is always kept at a preset value. When the rotation speed of the engine fluctuates, the motor displacement is regulated in real time through the controller.
  2. 2. The method for testing the heat balance of the whole hydrostatic transmission engineering equipment according to claim 1, wherein when the required working power of the hydraulic pump is calculated through the external characteristic power parameters corresponding to the real-time rotating speed of the engine and the preset rotating speed of the engine and the test required load factor, the calculation formula is as follows: ; Wherein: For the power output from the engine to the hydraulic pump, For the external characteristic power at the current rotational speed of the engine, The load factor was required for the test and, Power for engine accessories.
  3. 3. The method for testing the thermal balance of a hydrostatic transmission engineering equipment complete machine according to claim 2, wherein when working pressure of an electrically controlled variable hydraulic motor is calculated by combining displacement of a hydraulic pump, the calculation formula is as follows: ; ΔR; Wherein: For the working pressure of the hydraulic pump, For the mechanical efficiency of the hydraulic pump, For the current rotational speed of the engine, For the displacement of the hydraulic pump, Is the hydraulic motor operating pressure, ΔR is the hydraulic system pressure drop.
  4. 4. The method for testing the thermal balance of the hydrostatic transmission engineering equipment as set forth in claim 3, wherein the preset parameters of the test vehicle include a vehicle weight, a tire rolling resistance coefficient, a transmission total speed ratio, a total transmission efficiency, a wheel rolling radius, an acceleration resistance coefficient, an air resistance coefficient, a total windward area and a transmission efficiency, and when the motor driving moment is calculated according to the real-time vehicle speed, the acceleration, the climbing gradient and the preset parameters of the test vehicle, the calculation formula is as follows: ; ; Wherein: in order to test the running resistance moment of the vehicle, For the rolling radius of the wheel, In order to test the mass of the vehicle, The acceleration of the gravity is that, In order to climb the slope of the road, The tire rolling resistance coefficient, a is the acceleration of the test vehicle, u is the acceleration resistance coefficient, C is the air resistance coefficient, S is the windward area of the whole vehicle, v is the running speed of the test vehicle, For the driving moment of the motor, For the overall speed ratio of the transmission system, Is the total transmission efficiency.
  5. 5. The method for testing the thermal balance of a hydrostatic transmission engineering equipment as set forth in claim 4, wherein when calculating the required motor displacement from the motor drive torque and the motor operating pressure, the calculation formula is as follows: ; Wherein: for the displacement of the motor, Is the mechanical efficiency of the motor.
  6. 6. The method for testing the heat balance of the whole hydrostatic transmission engineering equipment according to claim 1, wherein when the rotation speed of the engine fluctuates, the feedback of the rotation speed of the engine is received in real time through the controller, and the motor displacement is regulated, particularly when the rotation speed of the engine rises, the external characteristic power rises, the power of the hydraulic pump is increased to keep the real-time load rate unchanged, the motor displacement is regulated to reduce through the controller, and when the rotation speed of the engine decreases, the external characteristic power falls, the power of the hydraulic pump is reduced to keep the real-time load rate unchanged, and the motor displacement is regulated to increase through the controller.
  7. 7. A readable storage medium, characterized in that it stores a computer program adapted to be loaded by a processor and to perform the hydrostatic transmission engineering equipment complete machine thermal balance test method of any one of claims 1-6.
  8. 8. A computer device, characterized in that it comprises a memory and a processor, said memory storing a computer program which, when executed by said processor, runs the hydrostatic transmission engineering equipment complete machine thermal balance test method of any one of claims 1-6.

Description

Complete machine heat balance test method, medium and equipment for hydrostatic transmission engineering equipment Technical Field The invention relates to the technical field of engineering machinery, in particular to a complete machine heat balance test method, medium and equipment for hydrostatic transmission engineering equipment. Background The hydrostatic transmission system is widely applied to engineering machinery, and the transmission principle is that an engine drives a hydraulic pump to convert mechanical energy into hydraulic pressure energy, pressure oil enters a hydraulic motor through a control element, and the hydraulic motor converts the pressure energy into mechanical energy to drive a speed reducer, an axle and wheels. The whole machine heat balance test verifies the maximum heat radiation performance and reliability of the cooling system by simulating the extreme load working condition, and ensures that the vehicle can still work normally under the extreme working conditions such as high temperature, high load and the like. The test has important significance for evaluating and improving the performance of the whole machine. The simulated extreme load conditions are typically achieved by connecting the test vehicle to a resistance loading device, such as a trailer device or a dedicated loading device, passing the trailer and braking continuously in the prior related patents (such as CN113984390a and CN117147177 a), the load test equipment is a set of complete engineering chassis, and comprises a cab, a frame, a power transmission system, axle wheels, a brake or retarder and a heat dissipation system. The test vehicle is required to pull the load equipment to continuously run the vehicle for a long time during the test, the speed adjustment of the test vehicle and the braking force adjustment of the rear vehicle are difficult to match, and the safety risk is high. The patent CN118010376A simulates a limit load through a special loading test bed to perform a heat balance test, and a whole set of loading platform and loading unit are required to be built, so that the test device of the method has complex design and higher cost. Disclosure of Invention The invention mainly aims to provide a complete machine heat balance test method, medium and equipment for hydrostatic transmission engineering equipment, and aims to solve the technical problems of complex tooling, high cost, high operation difficulty and low safety of the existing heat balance test method. In order to achieve the purpose, the invention provides a complete machine heat balance test method for hydrostatic transmission engineering equipment, which comprises the following steps: the power transmission chain of the test vehicle comprises an engine, a hydraulic pump, a hydraulic pipeline, a control valve group, an electric control variable hydraulic motor, a controller, a speed reducer, an axle and wheels, wherein the engine is connected with the hydraulic pump, the hydraulic pump is connected with the electric control variable hydraulic motor through the hydraulic pipeline and the control valve group, the controller is connected between the engine and the electric control variable hydraulic motor, the electric control variable hydraulic motor is connected with the speed reducer, the speed reducer is connected with the axle through transmission of a transmission shaft, and the wheels are fixed on the axle. The test vehicle is also provided with an electric module such as a vehicle speed sensor, an acceleration sensor, a gradient sensor and the like. The controller is used for collecting the real-time rotating speed of the engine, calculating the required working power of the hydraulic pump according to the external characteristic power parameter corresponding to the rotating speed of the engine and the test required load factor, and then calculating the working pressure of the hydraulic motor by combining the displacement of the hydraulic pump and the pressure drop of the hydraulic system. Parameters such as the speed, acceleration, climbing gradient and the like of the whole vehicle are collected through the controller, and the motor driving moment is calculated according to preset parameters of the test vehicle. The required motor displacement can be calculated by integrating the motor driving moment and the working pressure. During the heat balance test, a driver controls a test vehicle accelerator to keep the engine at the rated rotation speed or the maximum torque rotation speed, and the controller sends a corresponding motor displacement signal to the electric control variable hydraulic motor according to the calculation result to keep the engine load rate at the preset value all the time. When the rotation speed of the engine fluctuates, the motor displacement can be regulated in real time through the controller, so that the test load requirement of the whole vehicle is met, and the normal running of the whole vehicle can