Torque verification tool for bidirectional hydraulic dynamometer

Abstract

A tool for verifying the torque of a bidirectional hydraulic dynamometer relates to the technical field of machinery and comprises a force application plate, a base and a cushion block. An upper circular hole of the force application plate is used for being connected with a dynamometer shell, and a lower square neutral position is used for being matched with a base to place a pressure sensor. The upper part of the base is a hollow square frame with a through side surface, a square hole in the top of the square frame is used for enabling the force application plate to go deep into the base, and a lower circular hole is used for being connected with a dynamometer base. The cushion block is installed in the trapezoid groove of the square empty space of the force application plate, is made of materials with high yield strength and is used for reducing the pressure intensity borne by the force application plate. And the pressure sensor is used for measuring the force applied by the device to the dynamometer shell. When the checking tool is used for checking, the pressure sensor can be placed on the upper portion of the base or inside the base so as to achieve torque checking of the dynamometer in the pressing direction and the pulling direction, the checking process is simplified, the reversing time of the dynamometer is saved, and the purchasing and checking cost of a bidirectional sensor is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical testing and calibration, and particularly to a torque calibration tool for a two-way hydraulic dynamometer, which is particularly applicable to the forward and reverse torque accuracy calibration of hydraulic dynamometers in scenarios such as diesel engines and marine power systems. Background Art

[0002] In the production process of diesel engines, a hydraulic dynamometer is usually used to simulate the working scenario of the diesel engine, so as to quantify the power generated by the operation of the diesel engine. The working principle of the hydraulic dynamometer is as follows: The hydraulic dynamometer consists of a rotor, a housing, a base, and a pressure sensor. The housing is installed on the base through rolling bearings and can rotate freely relative to the base. The pressure sensor is installed between the housing and the base. The rotor is installed inside the housing through bearings and can rotate freely relative to the housing. The outside of the rotor and the inside of the housing are both covered with blades. Connect the rotor of the hydraulic dynamometer to the crankshaft of the diesel engine, inject flowing water into the housing of the hydraulic dynamometer. When the crankshaft of the diesel engine rotates, it drives the rotor of the dynamometer to rotate together. At this time, the rotor does work on the water inside the dynamometer to drive the water to rotate, and the rotation of the water exerts a force on the housing of the dynamometer in the same direction as the rotation direction, so that the stator exerts a force on the pressure sensor installed between the stator and the base of the dynamometer. The control module of the dynamometer processes the received analog signal and converts it into the power output by the diesel engine in this state. Usually, the sensors used in hydraulic dynamometers can only measure pressure, so the power can only be measured in a single rotation direction state. Therefore, when measuring diesel engines with different rotation directions, a commutation operation is required. The two-way hydraulic dynamometer uses a sensor that can detect both tension and pressure, avoiding repetitive operations such as lifting and positioning caused by frequent commutation of the dynamometer.

[0003] With the development of technology, two-way hydraulic dynamometers are gradually adopted, which avoid the problem of frequent commutation by integrating two-way sensors (which can detect both pressure and tension). However, such dynamometers need to be strictly calibrated for torque before being put into use to ensure that the torque value displayed by the control module is consistent with the theoretical value. Currently, there are two major problems in the calibration of two-way sensors:

[0004] Lack of calibration equipment: There is no special calibration tool in China that is suitable for two-way sensors, resulting in the calibration work relying on imported equipment, which is costly and inconvenient to maintain;

[0005] Complex process: Existing calibration methods require the use of special two-way sensors, and the sensors and adjustment tooling need to be repeatedly disassembled and assembled during calibration, resulting in low efficiency. Summary of the Invention

[0006] In view of the above problems, the present invention provides a torque calibration tool for a two-way hydraulic dynamometer, aiming to overcome the cumbersome use of a single-way dynamometer and the difficult calibration of a two-way dynamometer. This tool can flexibly configure a single-way pressure sensor at different positions to achieve two-way calibration in the pressing and pulling directions, making the calibration of the two-way dynamometer more convenient, expanding the selection range of the dynamometer, and solving the problems raised in the above background technology.

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions: A torque calibration tool for a two-way hydraulic dynamometer, including a base, characterized in that: the base is connected to the hydraulic dynamometer base through a lower round hole, the upper part of the base is a hollow square box, the side is used to place the pressure sensor, and the top square hole is used to pass through the force application plate. The force application plate is connected to the hydraulic dynamometer housing through an upper round hole, and there are 2 trapezoidal notches in the lower empty space of the force application plate for installing the cushion blocks. The base and the force application plate act on each other through the pressure sensor. When the pressure sensor is placed inside the square box of the base, the device can measure the pulling force applied to the dynamometer housing; when the pressure sensor is placed on the upper part of the square box of the base, the device can measure the pushing force applied to the dynamometer housing.

[0008] Preferably, after the base and the force application plate are installed on the dynamometer, the bottom end of the force application plate is suspended inside the upper square box of the base, and the lower empty space of the force application plate is divided into 2 parts by the base, and calibration pressure sensors can be placed in both parts. After assembly, the distance from the center of the lower round hole of the base to the center of the upper round hole of the force application plate is 422 mm.

[0009] Preferably, the trapezoidal vacancy on the force application plate is adapted to the size of the cushion block, and through calculation, its contact area can effectively reduce the torque received by the force application plate. Under the limit torque, the pressure received by the force application plate will be reduced to within the yield limit of the material used.

[0010] Preferably, the materials selected for the base and the force application plate are 2030 aluminum alloy. Under the limit torque, according to the force analysis, the tensile and shear forces received by the minimum cross-section of each of the force application plate and the base are less than the yield strength of 2030 aluminum alloy.

[0011] Preferably, the cushion block is made of alloy steel with a yield strength greater than 1000 MPa after heat treatment, which can withstand the pressure applied under the limit state.

[0012] The present invention provides a torque calibration tool for a two-way hydraulic dynamometer, which has the following beneficial effects:

[0013] 1. This torque calibration tool for a two-way hydraulic dynamometer changes the connection state of the dynamometer through a special tooling, so that only a single-way pressure sensor can be used to complete the calibration. The cost of purchasing and sending a two-way pressure sensor for inspection is reduced.

[0014] 2. The torque calibration tool for the two-way hydraulic dynamometer simplifies the calibration method of the two-way dynamometer by calculating the connection dimensions of the tooling, avoids frequent disassembly and assembly when using a special calibration sensor, and greatly improves the labor production efficiency. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram after the overall assembly of the present invention;

[0016] Figure 2 It is a schematic structural diagram of the base of the present invention;

[0017] Figure 3 It is a schematic structural diagram of the force application plate of the present invention;

[0018] Figure 4 It is a schematic structural diagram of the cushion block of the present invention;

[0019] Figure 1 In the figure: 1. Base; 2. Force application plate; 3. Cushion block. Detailed Embodiment

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0021] A torque calibration tool for a two-way hydraulic dynamometer includes:

[0022] Base 1, as Figure 2 shown, is divided into upper and lower parts. The upper part of the base is composed of 4 aluminum alloy plates welded into a hollow square box with a through side. A square through hole (the size is adapted to the thickness of the force application plate 2) is opened at the top for passing through the force application plate 2. The side opening of the square box is convenient for placing the pressure sensor. The lower part is a circular connection plate, with a circular hole machined in the center (bolted to the base of the hydraulic dynamometer) and fixed to the bottom plate of the square box by bolts. When installing the base 1, it is necessary to ensure that the circular hole in its lower part is aligned with the base of the dynamometer and keep it horizontal after the bolts are tightened.

[0023] Force application plate 2, as Figure 3As shown, it is a flat and elongated aluminum alloy plate, divided into upper and lower parts: the upper part is processed with a circular through-hole and connected to the shell of the hydraulic dynamometer through bolts to ensure the rigid fixation of the force application plate 2 and the shell. The lower part is provided with a rectangular gap, and symmetrical trapezoidal notches are processed at the upper and lower edges of the gap (for installing the spacer block 3). When the force application plate (2) is inserted into the square hole at the top of the base (1), its gap is divided into upper and lower regions by the base (1): the upper half region is used to place the pressure sensor during the compression calibration. The lower half region is used to place the pressure sensor during the tension calibration. After the force application plate (2) is inserted into the base (1), it is necessary to ensure that its lower end is suspended inside the base square and the gap with the inner wall of the base is uniform.

[0024] The spacer block 3, as Figure 4 shown, is a trapezoidal block structure, made of heat-treated alloy steel with a yield strength > 1000 MPa. Its shape fits tightly with the trapezoidal notch of the force application plate (2) and is embedded in the notch through interference fit, used to disperse the local pressure of the force application plate (2) under the ultimate torque. After the spacer block (3) is installed, it needs to completely fill the trapezoidal notch without looseness or deviation. The spacer block is made of high-strength alloy steel, and by increasing the contact area, the local pressure of the force application plate is reduced below the material yield limit to avoid plastic deformation.

[0025] The operation steps of the calibration tool in this embodiment

[0026] 1. Tool installation

[0027] Fix the base 1 to the base of the hydraulic dynamometer through the lower round-hole bolts.

[0028] Fix the force application plate 2 to the shell of the dynamometer through the upper round-hole bolts, ensuring that the force application plate 2 is vertically inserted into the square hole at the top of the base 1 to form a rigid connection.

[0029] Embed the spacer block 3 into the trapezoidal notch of the force application plate 2 to ensure no gap at the contact surface.

[0030] 2. Sensor configuration

[0031] Compression calibration: Place the pressure sensor on the upper half region of the gap of the force application plate 2 on the top of the square of the base 1 (i.e., the upper part of the base square). At this time, the force application plate 2 is displaced downward under pressure, and the sensor measures the thrust signal.

[0032] Tension calibration: Place the pressure sensor on the lower half region of the gap of the force application plate (2) inside the square of the base 1 (i.e., the side opening of the base square). At this time, the force application plate (2) is displaced upward under tension, and the sensor measures the tension signal.

[0033] 3. Calibration execution

[0034] Start the control module of the dynamometer and apply a preset torque to the force application plate (2) (such as loading through a hydraulic cylinder).

[0035] Record the output value of the pressure sensor and compare it with the theoretical torque value to calibrate the display accuracy of the dynamometer control module.

[0036] After completing the one-way calibration, only move the position of the sensor, without disassembling the tool, and you can switch to the other direction for calibration.

[0037] When in use, install the base and the force application plate on the dynamometer base and the dynamometer housing respectively. Then, according to the need of the calibration direction, place the pressure sensor inside or outside the base square. Then, apply a specified torque to the sensor to achieve the purpose of simple and fast calibration in any direction.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. Moreover, the terms "include", "comprise" or any other variation thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0039] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A torque calibration tool for a bidirectional hydraulic dynamometer, comprising a base (1), a force application plate (2) and a cushion block (3), characterized in that: The lower part of the base (1) is provided with a circular connection hole for connecting to the base of the hydraulic dynamometer; the upper part of the base (1) is a hollow square frame with a through side; the side of the square frame is used to place a pressure sensor; the top of the square frame is provided with a square hole for passing a force application plate (2); The upper part of the force-applying plate (2) is provided with a circular connecting hole for fixing to the housing of the hydraulic dynamometer; the lower part of the force-applying plate (2) is provided with a rectangular gap, and the upper and lower edges of the gap are symmetrically processed with trapezoidal notches for installing a cushion block (3); The cushion block (3) is a trapezoidal block structure, adapted to be embedded in the trapezoidal notch of the force application plate (2) and used to disperse the local pressure; The pressure sensor can be selectively placed on the top or inside of the base (1) frame to respectively implement compressive or tensile torque calibration of the dynamometer housing.

2. The torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The base (1) and the force-applying plate (2) interact with each other via a pressure sensor; when the pressure sensor is placed in the base (1) frame, the device can measure the pulling force applied to the dynamometer housing; when the pressure sensor is placed on the upper part of the base (1) frame, the device can measure the thrust applied to the dynamometer housing.

3. A torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The upper part of the base (1) is welded from four alloy plates into a hollow square frame. The side opening of the square frame is used to place a pressure sensor. The size of the square through hole on the top of the square frame matches the thickness of the force plate (2), ensuring that a rigid connection is formed after the force plate (2) is vertically inserted.

4. A torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The rectangular space of the force-applying plate (2) is divided into upper and lower parts by the base (1); the upper part is used for placing a pressure sensor during compression calibration, and the lower part is used for placing a pressure sensor during tension calibration.

5. A torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The cushion block (3) is made of alloy steel with a yield strength greater than 1000 MPa, and its trapezoidal cross section is interference-fitted with the notch of the force-applying plate (2), and the contact area is optimized to reduce the local pressure of the force-applying plate (2).

6. The torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The base (1) and the force application plate (2) are made of 2030 aluminum alloy, and the tensile and shear stresses at the smallest cross-section are lower than the yield strength of the material.

7. The torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The distance between the center of the lower circular hole of the base (1) and the center of the upper circular hole of the force-applying plate (2) is 422 mm. This dimension is determined by moment balance calculation to ensure a standardized force arm length during calibration.

8. The torque calibration tool for a bidirectional hydraulic dynamometer according to claim 1, characterized in that: The pressure sensor is a unidirectional sensor, and by adjusting its position in the frame of the base (1), bidirectional calibration of the dynamometer in the compression direction and the tension direction can be achieved without replacing the sensor or disassembling tools.

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