Dilator performance test bench

Abstract

The application is a dilator performance test bench, which overcomes the technical function problems of low test precision, poor tool adaptability and inability to simultaneously measure bilateral thrust and displacement in the prior art. The application comprises a base platform, a left force base, a right force base, a dilator fixing base, a gas-liquid pressure boosting system, a sensor system, a safety shield and a measurement and control system. The left force base and the right force base are symmetrically arranged and have the same structure, and are respectively driven by a left electric cylinder and a right electric cylinder to move along a slide rail arranged on the base platform. The dilator fixing base is arranged between the left force base and the right force base. The gas-liquid pressure boosting system comprises a gas-liquid pressure boosting cylinder and a manual switching valve, and is used for providing pneumatic and hydraulic test power. The sensor system comprises a left force sensor, a left displacement sensor, a right force sensor and a right displacement sensor arranged on the left force base and the right force base respectively, and a force sensor and a displacement sensor arranged on the dilator fixing base. The safety shield is arranged on the base platform and has a safety interlocking function.

Description

Technical Field

[0001] This invention belongs to the field of automotive braking system testing technology, and relates to a test device for detecting the output thrust, displacement and performance relationship between the expander and brake chamber of the braking system of heavy truck vehicles. Background Technology

[0002] Wedge brakes, as a key component of heavy-duty truck braking systems, are gradually replacing traditional cam drum brakes due to their high efficiency and lightweight advantages. The expander, as a core braking component, directly determines the reliability, response speed, and service life of the braking system. This component can independently adjust the clearance based on the wear of the leading and trailing shoe friction pads, and efficiently convert the linear thrust of the brake chamber into an expanding force on the brake shoes, generating braking torque. Different expander structures produce different leverage ratios, resulting in significant differences in the thrust generated on the brake shoes; therefore, accurate testing of its output characteristics is crucial.

[0003] Currently, performance testing of expanders in the industry suffers from limitations and deficiencies. Traditional testing methods rely heavily on simple tooling fixtures and discrete measuring instruments, such as handheld push-pull gauges and dial indicators, which cannot achieve synchronous, real-time acquisition of thrust and displacement on both sides of the expander during dynamic operation. This data acquisition method is not only inefficient and prone to human error, but also fails to capture the continuous relationship between thrust and displacement changes and the dynamic curve representation, making it difficult to comprehensively and accurately reflect the dynamic working characteristics of the expander. Due to differences in structural dimensions and installation interfaces among expanders of different vehicle models and specifications, existing expander performance testing equipment is mostly dedicated to specific applications, lacking universal, universally applicable, and quickly adjustable clamping mechanisms. This leads to frequent changes or even redesign and manufacturing of tooling when changing test products, resulting in long preparation cycles, poor flexibility, and an inability to meet the needs of multi-variety, batch-type R&D, testing, and quality inspection. Existing equipment has a low degree of automation; the entire testing process, including product clamping, alignment, loading, and data recording, heavily relies on manual operation. This leads to difficulties in ensuring the repeatability and consistency of test results, increases the workload of operators, and reduces testing efficiency. Furthermore, some equipment lacks adequate safety measures, such as the absence of safety shields and other safety facilities around the equipment, neglecting the protection of users and resulting in low safety. Most existing equipment can only perform tests on a single power source, such as purely pneumatic systems, and cannot integrate performance and sealing tests of components such as pneumatic and hydraulic brake cylinders on the same equipment. In addition, there is a lack of effective simulation of the expander return process after braking, resulting in discrepancies between the test conditions and the actual on-vehicle operating conditions, reducing the authenticity and engineering guidance value of the test results. The equipment lacks necessary safety protection devices and software safety linkage functions, posing safety hazards during high-pressure testing. Test data processing relies on manual recording, lacking automated data storage, analysis, and report generation capabilities, and lacking product quality traceability and statistical analysis of system test data.

[0004] Therefore, developing a test bench for expandinger performance testing with features such as high precision, synchronous measurement, rapid adaptation, system integration, multi-functionality, wide applicability, high automation, intelligent control, and safety and reliability is of great urgent need and significance for improving the testing technology, product development level, production process quality control, and ensuring the safety of vehicles at the end of the braking system. Summary of the Invention

[0005] The purpose of this invention is to provide a test bench for testing the performance of expanders, which overcomes the technical problems of low testing accuracy, poor tooling adaptability, inability to simultaneously measure bilateral thrust and displacement, and poor safety protection performance in existing technologies. This invention, with its high-precision automated testing, can perform tests on the thrust and displacement of the expander brake chamber under pneumatic and hydraulic combined operating conditions; expander assembly return performance testing; and pressure holding and sealing performance testing of the hydraulic brake wheel cylinder. It also features adaptability to various types and specifications, data visualization, and safety protection functions.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An expander performance testing bench, characterized in that it includes a base platform, a left force measuring base, a right force measuring base, an expander fixing base, a gas-liquid pressurization system, a sensor system, and a measurement and control system; The left force measuring base and the right force measuring base have the same structure and are arranged symmetrically. They are driven to move along slide rail one and slide rail two on the foundation platform by the left electric cylinder and the right electric cylinder, respectively. The expander fixing base is located between the left force measuring base and the right force measuring base, and its upper part is provided with a transition flange and a clamping device for installing the expander and the brake air chamber; the gas-hydraulic booster system includes a gas-hydraulic booster cylinder and a manual switching valve for providing pneumatic and hydraulic test power. The sensor system includes a left force sensor, a left displacement sensor and a right force sensor and a right displacement sensor respectively installed on the left force measuring base and the right force measuring base, as well as a force sensor and a displacement sensor installed on the expander fixing base; The safety cover is composed of profile components, is set on the base platform, covers the entire test area, and includes a protective cover door and magnetic buckles, with a safety interlock function.

[0007] The measurement and control system includes an industrial computer and a data acquisition card, which are used to control the test process, acquire sensor data, and generate test reports.

[0008] The left force measuring base and the right force measuring base respectively include a left bearing arm, a right bearing arm, a left cylinder, and a right cylinder; the extended ends of the left cylinder and the right cylinder pass through the left bearing arm and the right bearing arm, and are detachably connected to the ends of the left transition plate and the right transition plate.

[0009] The bottom of the left and right transition plates cooperates with slide rail one and slide rail two on the base platform to achieve linear sliding; the ends of the left and right transition plates are provided with left and right pull plates, which cooperate with left and right displacement sensors to measure displacement.

[0010] The expander fixed base is provided with a bearing arm, the bottom of which is slidably connected to the base platform through slide rail three and slide rail four; the bearing arm is provided with a force sensor and a displacement sensor, and the displacement sensor is connected to the brake air chamber through a pull plate.

[0011] The distance adjustment device includes a left electric cylinder, a right electric cylinder, and a multi-screw locking mechanism; the screw locking mechanism includes multiple screws and locking nuts located between the left and right bearing arms, used to lock the left and right force measuring bases after position adjustment.

[0012] The outer sides of the left and right load-bearing arms are connected to the extended ends of the left and right electric cylinders, respectively, and the bottoms of the left and right load-bearing arms slide on the top of the foundation platform.

[0013] The left and right cylinders are thin cylinders. The left and right cylinders press the left and right transition plates against the expander. When the brake returns to its original position, the simulated return spring causes the push rods at both ends of the expander to return to their original position. When the expander is reset, the left and right cylinders push out to reset the expander top seat together with the expander. At the same time, the left and right displacement sensors provide feedback on the displacement.

[0014] The bottom of the support arm slides on the top of the foundation platform; the support arm slides linearly within slide rails three and four; a force sensor and a displacement sensor are installed at the connection between the expander and the brake chamber; a pull plate two is installed at the front end of the expander, and the displacement sensor two is installed between the brake chamber and the pull plate two to detect the output force and displacement of the brake chamber under a certain air pressure.

[0015] The test bench base is equipped with a detachable safety cover, which is assembled from profiles and covers the entire equipment base platform, providing safety protection during testing. The safety cover has four pairs of opening and closing protective doors, and each door is equipped with a magnetic snap fastener. After the equipment is ready, closing the four pairs of protective doors will cause the magnetic snap fasteners to engage, and the test can begin. If any pair of protective doors is opened during the test, causing the magnetic snap fasteners to separate, the equipment will immediately and automatically stop the test, providing an interlocking protection function.

[0016] A method for implementing an expander performance testing bench, characterized by the following steps: First, the expander to be tested and the brake chamber are installed and fixed on the support arm. Then, the measurement and control software is opened, and the corresponding preset test parameters are entered in the parameter input interface. After checking whether the equipment installation and preset parameters are correct, the protective door of the safety guard is closed, and the test is started. Subsequently, the preset parameters are entered into the data acquisition card, and the signal is sent to the cylinder and electric cylinder to be controlled through the data acquisition card. After the test starts, the measurement and control system first controls the left and right electric cylinders to synchronously drive the left and right force measuring bases to move towards each other along slide rail one and slide rail two to the preset displacement. Then, the locking nuts on the multiple screws connected between the left and right support arms are tightened to firmly lock the entire force measuring mechanism and ensure the rigidity of the test system. According to the preset test mode, the gas-liquid pressurization system starts to work: if a pneumatic test is performed, the set air pressure is input into the brake chamber; if a hydraulic test is performed, the pressure is increased by switching the valve. The air circuit introduces the air-hydraulic booster cylinder, generating high-pressure hydraulic oil which is then delivered to the hydraulic brake air chamber. Under pressure, the push rod of the brake air chamber extends outward, and its end directly acts on the force sensor to measure the output thrust in real time. Simultaneously, the displacement sensor drives the pull plate to record the push rod displacement in real time. At the same time, driven by the thrust of the air chamber, the left and right push rods of the expander push the left and right transition plates to slide along the slide rails respectively. The left and right force sensors directly measure the output thrust on both sides of the expander, while the left and right displacement sensors monitor the extension displacement of the push rod in real time through the left and right pull plates, achieving synchronous and accurate acquisition of thrust and displacement. After a single loading test is completed, the system releases pressure, and the left and right cylinders extend to push the left and right transition plates and expander push rods back to their original positions, simulating the return process during actual braking. The displacement sensor monitors the smoothness and completeness of the return process throughout. During the entire process, any equipment malfunction, safety accident, or need to terminate the test can be stopped by pressing the emergency stop button on the measurement and control software interface. All sensor signals are transmitted to the data acquisition card in real time, and the measurement and control software displays and records the thrust-displacement curve and pressure-time curve data synchronously. After the test, each actuator automatically resets, and the measurement and control software automatically generates a test report containing key parameters, graphs, and performance conclusions based on the collected data.

[0017] Compared with the prior art, the advantages and effects of the present invention are as follows: 1. By setting force sensors and displacement sensors at the left and right ends of the expander and at the connection with the brake chamber, the present invention achieves synchronous and accurate measurement of the output force and displacement of the brake chamber and the output force and displacement of both sides of the expander. This invention can comprehensively reflect the overall performance of the expander under braking conditions and overcomes the shortcomings of existing technologies that have single data and cannot be measured synchronously.

[0018] 2. This invention achieves rapid and precise positioning and mounting of expanders of different specifications by automatically aligning the left and right force-measuring bases with an electric cylinder, combined with a lead screw locking mechanism. The measurement and control system integrates automatic control and data acquisition, completing the test function and generating a report with one click, greatly improving testing efficiency and reducing human error.

[0019] 3. This invention adopts a modular design. Through replaceable transition devices, adapter flanges and adjustable sliding bases, the test bench can be quickly adapted to various models and specifications of expanders and brake chambers, realizing performance testing of all types of expanders, expanding capacity and multi-functional use with one machine.

[0020] 4. This invention integrates two power systems, pneumatic and hydraulic, which can be used to test the performance of pneumatically driven expanders as well as the sealing and performance of hydraulic brake wheel cylinders, thus meeting the testing needs of various components of automotive braking systems and expanding the application range of the test bench.

[0021] 5. This invention is equipped with an overall safety protective cover and has a safety interlock function. The control system has built-in overload protection, emergency stop and power failure protection programs, which ensure the safety of operators and equipment from both mechanical and electrical perspectives, and comply with relevant national safety standards.

[0022] 6. The key connection parts of this invention adopt a high coaxiality design. The base is guided by slide rails and locked by screws, which ensures the accuracy of force transmission and the rigidity of the system during the test, so that the test results have accurate repeatability and reliability.

[0023] 7. The measurement and control software of this invention can display the thrust-displacement curve in real time, record the data of the whole process, and has the functions of historical data query, printing and sensor calibration, providing intuitive and powerful data support for product performance analysis, quality control and R&D improvement.

[0024] 8. The present invention designs a simulated return mechanism with a reset cylinder, which can realistically simulate the return process of the expander after braking ends, making the test conditions closer to the actual vehicle condition, and the test results have more engineering guidance value. Attached Figure Description

[0025] Figure 1 This is a top view of the overall structure of the present invention; Figure 2 This is a front view of the overall structure of the present invention; Figure 3 This is a left-side view of the overall mechanism of the present invention; Figure 4 This is a schematic diagram of the distance adjustment device of the present invention; Figure 5 This is a schematic diagram of the load-bearing arm structure; Figure 6Top view of the safety shield: Figure 7 This is a flowchart of the present invention.

[0026] In the diagram: 1. Expander; 2. Brake chamber; 3. Base platform; 4. Left bearing arm; 5. Right bearing arm; 6. Slide rail one; 7. Slide rail two; 8. Left cylinder; 9. Right cylinder; 10. Left electric cylinder; 11. Right electric cylinder; 12. Left force sensor; 13. Right force sensor; 14. Left displacement sensor; 15. Right displacement sensor; 16. Left pull plate; 17. Right pull plate; 18. Bearing arm; 19. Slide rail three; 20. Slide rail four; 21. Force sensor; 22. Displacement sensor; 23. Pull plate; 24. Lead screw; 25. Left transition plate; 26. Right transition plate; 27. Locking nut; 28. Left force measuring base; 29. ​​Right force measuring base; 30. Expander fixing base; 31. Distance adjustment device; 32. Safety guard; 33. Guard door; 34. Magnetic buckle. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] The test bench mechanism of this invention includes a left force-measuring base, a right force-measuring base, and a middle expander fixing base. The left force-measuring base is equipped with a 10T force sensor and a displacement sensor. A cylinder push rod connects the sensor to the top of the expander. A displacement sensor moving pull plate is installed on the expander head. When the expander extends under force, it pushes the displacement sensor to measure the displacement, and the displacement signal is simultaneously fed back to the computer. The force is also transmitted to the force sensor through the top of the expander. When the expander resets, the cylinder pushes out, resetting the expander top and the expander together, while the displacement sensor provides displacement feedback. When adjusting the expander's extension displacement, the screw nut around the force sensor base can be loosened, followed by the base nut. Then, the force-measuring base is moved by an electric cylinder. The displacement is displayed on the displacement sensor monitoring interface. After adjusting the position, the base nut is locked, and then the screw nut is locked, completing the expander displacement adjustment. The left force-measuring base has the same function as the right one. In addition to fixing the expander, the intermediate expander mounting base also includes a transition sleeve. This sleeve connects the expander and the air chamber with a coaxiality of less than 0.05mm. This ensures the air chamber push rod is exposed and the connection is vertical, allowing for the installation of a displacement sensor pull plate and a force sensor. When the air chamber pushes the push rod downwards, the force sensor measures the thrust of the air chamber, while the pull plate moves to measure the displacement of the push rod. A transition plate is installed between the expander and the intermediate base to accommodate expanders of different sizes. An auxiliary support seat is provided at the expander end, and the auxiliary support is adjusted between the seat and the expander using nuts. The expander sample to be tested is installed in the mounting position of the testing device on the base platform. Test information and parameters are entered according to the test requirements, and the test begins.

[0029] The present invention will now be described in detail: This invention employs a comprehensive performance testing device for the brake chamber. Under different chamber thrust, gas, and hydraulic pressure conditions, it has the function of simultaneously measuring thrust and displacement on both sides, accurately testing the changes in loading force and displacement of the expander push rod. The test bench includes a force measuring base arranged symmetrically on both sides, an expander fixing base, a gas and hydraulic pressurization system, a distance adjustment device system, a sample clamping device, a safety guard, and a measurement and control system. The left and right force-measuring bases are driven by electric cylinders to move along linear slide rails, completing rapid alignment with expanders of different specifications; the expander fixing base is equipped with an adapter flange and a transition sleeve to ensure coaxiality with the brake chamber; the air and hydraulic pressurization system provides pneumatic and hydraulic power sources; under a given air pressure, the loading force and displacement of the expander's left and right push rods under the drive of the brake chamber are accurately tested, as well as the expander assembly return performance test; the pressure holding performance and sealing performance test of the hydraulic brake wheel cylinder; simulating and verifying the smooth and thorough return of the expander after brake release; the safety guard has a safety interlock function to ensure the safety and reliability of the test; this invention has high testing accuracy, strong adaptability, and is suitable for the expansion force performance testing, type testing, and scheme testing of expanders in heavy truck braking systems.

[0030] It includes a basic platform, a left force measuring base, a right force measuring base, an expander fixing base, a gas-liquid pressurization system, a distance adjustment device, a sensor system, a safety protective cover, and a measurement and control system.

[0031] The base platform serves as the installation foundation for the entire device, and its surface is equipped with slide rail one, slide rail two, slide rail three, and slide rail four. The left and right force-measuring bases cooperate with slide rail one and slide rail two on the base through the sliders at their bottoms, and can move in opposite directions or in the opposite direction under the drive of the left and right electric cylinders, thereby achieving rapid alignment and positioning with expanders of different width specifications.

[0032] The left and right force-measuring bases are identical in structure and symmetrically arranged, each including a left support arm, a left cylinder, a left force sensor, a left displacement sensor, and a right support arm, a right cylinder, a right force sensor, and a right displacement sensor. Left and right force sensors are respectively installed on the inner sides of the left and right support arms for directly measuring the output thrust of the expander push rod. The extended ends of the left and right cylinders pass through the left and right support arms respectively and are connected to a replaceable transition end. The left and right cylinders mainly function as reset devices; after a single braking test, the left and right cylinders extend, pushing the transition and the expander push rod in contact with them back to their original positions, simulating the return spring function in an actual braking system. The bottom of the transition engages with the base slide rail to ensure its straightness of movement. A displacement sensor pull plate is provided at the end of the transition, interacting with the displacement sensor fixed on the support arm. During operation, when the expander push rod extends, it pushes the transition and pull plate to move, allowing the displacement sensor to measure the extension displacement of the push rod in real time.

[0033] The expander fixing base is located between the left and right force-measuring bases, and its upper part is equipped with an adapter flange and clamping device for mounting the expander body and brake chamber. A support arm is slidably connected to slide rails three and four on the base via a slider at the bottom. A force sensor and a displacement sensor are mounted on the support arm. The push rod of the brake chamber extends out, and its end directly acts on the force sensor to measure the output force of the chamber. At the same time, the push rod drives the displacement sensor through a pull plate to measure the push rod displacement of the chamber in real time.

[0034] The core of the distance adjustment device consists of two sets of electric cylinders and a lead screw locking mechanism. When it is necessary to adjust the extension displacement of the expander, the electric cylinders are activated to drive the left and right force measuring bases to move to the predetermined positions. After adjustment, the locking nuts on the multiple lead screws connected between the two bearing arms are rotated to firmly lock the bases onto the foundation platform, ensuring that the entire force measuring system maintains high rigidity and stability during subsequent tests with large thrust.

[0035] The pneumatic-hydraulic booster system includes a pneumatic-hydraulic booster cylinder and a manual switching valve, used to provide power for pneumatic and hydraulic tests. When performing pneumatic pressure tests, compressed air directly drives the brake chamber; when testing the hydraulic brake wheel cylinder, the switching valve directs the air path to the pneumatic-hydraulic booster cylinder, which converts low-pressure air into high-pressure hydraulic oil and delivers it to the brake wheel cylinder through a quick-connect coupling, with an oil pressure reaching 15 MPa.

[0036] The sensor system is integrated into the aforementioned mechanical structure, including force and displacement sensors mounted on the left and right force-measuring bases, as well as force and displacement sensors mounted on the expander fixing base. All these sensors operate synchronously, acquiring real-time data on the thrust and displacement of both sides of the expander, as well as the output thrust and displacement of the braking chamber.

[0037] The safety cover, assembled from profiles, covers the entire equipment base platform and provides safety protection during testing. The safety cover has four pairs of opening and closing protective doors, each with a magnetic latch at the closing point. Once the equipment is ready, closing all four pairs of doors causes the magnetic latches to engage, allowing the test to begin. If any pair of doors opens during the test, causing the magnetic latches to disengage, the equipment will immediately and automatically stop the test.

[0038] The measurement and control system includes an industrial computer, a data acquisition card, and dedicated measurement and control software. Test parameters are set on the software, and commands are issued via the dedicated software to control the pressure regulating valve in the gas-liquid booster system, outputting the set pressure and controlling the electric cylinder for automatic alignment. After pressure is applied to the brake chamber and the expander, the sensors feed back the measured force and displacement signals to the data acquisition card in real time. Example

[0039] like Figures 1 to 5As shown, this expander test bench includes a base platform 3, a distance adjustment device 31, an expander fixing base 30, a gas-liquid pressurization system, and a safety guard 33.

[0040] The base platform 3 is equipped with an expander 1 and a brake chamber 2, which are connected. A left force sensor 12 and a left displacement sensor 14, a right force sensor 13, and a right displacement sensor 15 are respectively installed at the left and right ends of the expander 1 and at the connection point between the expander 1 and the brake chamber 2. A left transition plate 25 and a right transition plate 26 are respectively installed on the left and right sides of the expander 1. The bottoms of the left transition plates 25 and 26 slide on the top of the base platform 3. The left transition plates 25 and 26 can be replaced according to different specifications of the expander 1. The base platform 3 is equipped with slide rails that match the sliding bottoms of the left transition plates 25 and 26, allowing for linear sliding.

[0041] Two sets of distance adjustment devices 31 are provided. The two sets of distance adjustment devices 31 respectively include a left bearing arm 4, a left electric cylinder 10, a right bearing arm 5, and a right electric cylinder 11. The outer sides of the left bearing arm 4 and the right bearing arm 5 are connected to the extended ends of the left electric cylinder 10 and the right electric cylinder 11, respectively. The bottom of the left bearing arm 4 and the right bearing arm 5 slides on the top of the foundation platform 3. The foundation platform 3 is provided with a slide rail 1 6 and a slide rail 2 7. The left bearing arm 4 and the right bearing arm 5 slide linearly within the slide rail 1 6 and the slide rail 2 7. It also includes a left cylinder 8 and a right cylinder 9, the extended ends of which pass through the left support arm 4 and the right support arm 5 respectively, and are detachably connected to the ends of the left transition plate 25 and the right transition plate 26. The left cylinder 8 and the right cylinder 9 are thin cylinders, which can press the left transition plate 25 and the right transition plate 26 against the expander 1. During braking and return, they can simulate a return spring, causing the push rods at both ends of the expander 1 to return to their original positions. When the expander 1 is reset, the left cylinder 8 and the right cylinder 9 push out to reset the top seat of the expander 1 together with the expander 1. At the same time, the left displacement sensor 14 and the right displacement sensor 15 provide feedback on the displacement. A left force sensor 12 and a left displacement sensor 14 are respectively installed on the left bearing arm 4 and the right bearing arm 5, and a right force sensor 13 and a right displacement sensor 15 are respectively installed on the left transition plate 25 and the right transition plate 26. A left pull plate 16 and a right pull plate 17 are respectively installed on the ends of the left transition plate 25 and the right transition plate 26. The left displacement sensor 14 and the right displacement sensor 15 are respectively installed between the left bearing arm 4 and the left pull plate 16, and between the right bearing arm 5 and the right pull plate 17. When the expander 1 is extended under force, it pushes the left displacement sensor 14 and the right displacement sensor 15 to measure the displacement. At the same time, the force is transmitted to the left force sensor 12 and the right force sensor 13 through the expander 1 to measure the output force.

[0042] A support arm 18 is provided at the base 30 of the expander, and the bottom of the support arm 18 slides on the top of the base platform 3. A slide rail 3 19 and a slide rail 4 20 are provided on the base platform 3, and the support arm 18 slides linearly within the slide rail 3 19 and the slide rail 4 20. A force sensor 21 and a displacement sensor 22 are provided at the connection between the expander 1 and the brake chamber 2. A pull plate 23 is provided at the front end of the expander 1, and the displacement sensor 22 is located between the brake chamber 2 and the pull plate 23, which can detect the output force and displacement of the brake chamber 2 under a certain air pressure. Multiple lead screws 24 are provided between the left support arm 4 and the right support arm 5, and both ends are evenly fixed by locking nuts 27; there are four lead screws 24; when it is necessary to adjust the extension displacement of the expander 1, loosen the locking nuts 27 on the lead screws 24, then loosen the locking nuts 27 on the left support arm 4 and the right support arm 5, and then drive it to move through the left electric cylinder 10 and the right electric cylinder 11. After the position is adjusted, lock the locking nuts 27 on the left support arm 4 and the right support arm 5, and then lock the locking nuts 27 on the lead screws 24. The extension displacement adjustment of the expander 1 is completed. It is suitable for the operation of expanders 1 of different specifications; the pressure output port of the hydraulic system booster cylinder in the gas-liquid booster system is connected to the hydraulic cylinder of the brake chamber 2 to provide the power source for the brake chamber.

[0043] The safety cover 32 is assembled from profiles and covers the entire equipment base platform 3, providing safety protection during testing. The safety cover 32 has four pairs of opening and closing protective doors 33, and each protective door 33 is equipped with a magnetic buckle 34 at its closing point. After the equipment is ready, the four pairs of protective doors 33 are closed, and the magnetic buckles 34 are attracted together, allowing the test to begin. If any pair of protective doors 33 is opened during the test, causing the magnetic buckles to separate, the equipment will immediately and automatically stop the test, providing an interlocking protection function.

[0044] During the test, to measure the extension displacement of the expander 1, first loosen the locking nut 27 on the lead screw 24, then loosen the locking nuts 27 on the left bearing arm 4 and the right bearing arm 5. Drive the left bearing arm 4 and the right bearing arm 5 to slide on the slide rail 1 6 and the slide rail 2 7 respectively, using the left electric cylinder 10 and the right electric cylinder 11, to the appropriate positions, and adjust the extension displacement of the expander 1. After adjustment, close the protective cover door 33, and the magnetic buckle 34 engages to start the test. The brake chamber 2 provides pressure to the expander 1 according to the set program. When the expander 1 extends under force, it pushes the left transition plate 25 and the right transition plate. Displacement is generated by 26. The left pull plate 16 and the right pull plate 17 on the left transition plate 25 and the right transition plate 26 respectively push the left displacement sensor 14 and the right displacement sensor 15 to measure the displacement. At the same time, the displacement signal is fed back to the computer. Simultaneously, the force is transmitted to the left force sensor 12 and the right force sensor 13 through the top of the expander 1, thereby completing one test and measuring the extension displacement and extension force of the expander 1. When the expander 1 is reset, the left cylinder 8 and the right cylinder 9 push out to reset the top seat of the expander 1 together with the expander 1. At the same time, the left displacement sensor 14 and the right displacement sensor 15 feed back the displacement.

[0045] The measurement and control software of this invention has functions including parameter setting, sensor calibration, data acquisition, curve plotting, report generation, and emergency stop. See also... Figure 7The working steps of this invention are as follows: First, the expander and brake chamber to be tested are installed and fixed on the support arm. Then, the measurement and control software is opened, and the corresponding preset test parameters are entered in the parameter input interface. After checking whether the equipment installation and preset parameters are correct, the protective door of the safety guard is closed, and the test is started. Subsequently, the preset parameters are entered into the data acquisition card, and the signal is sent to the cylinders, electric cylinders, etc. to be controlled through the data acquisition card. After the test starts, the measurement and control system first controls the left and right electric cylinders to synchronously drive the left and right force measuring bases to move towards each other along slide rail one and slide rail two to the preset displacement. Then, the locking nuts on the multiple screws connected between the left and right support arms are tightened to firmly lock the entire force measuring mechanism and ensure the rigidity of the test system. According to the preset test mode, the air-hydraulic booster system starts to work: if a pneumatic test is performed, the set air pressure is input into the brake chamber; if a hydraulic test is performed, the air circuit is introduced into the air-hydraulic booster cylinder through the switching valve to generate high-pressure hydraulic oil and deliver it to the hydraulic brake chamber. Under pressure, the push rod of the brake chamber extends outward, and its end directly acts on the force sensor to measure the output thrust in real time. At the same time, the displacement sensor drives the pull plate to record the displacement of the push rod in real time. Meanwhile, driven by the thrust of the air chamber, the left and right push rods of the expander push the left and right transition plates to slide along the slide rails respectively. The left and right force sensors directly measure the output thrust on both sides of the expander, while the left and right displacement sensors monitor the extension displacement of the push rod in real time through the left and right pull plates, realizing synchronous and accurate acquisition of thrust and displacement. After a single loading test is completed, the system releases pressure, and the left and right cylinders extend to push the left and right transition plates and expander push rods back to their original positions, simulating the return process during actual braking. The displacement sensor monitors the smoothness and completeness of the return process throughout. During the entire process, any equipment malfunction, safety accident, or need to terminate the test can be stopped by pressing the emergency stop button on the measurement and control software interface. All sensor signals are transmitted to the data acquisition card in real time, and the measurement and control software displays and records data such as thrust-displacement curves and pressure-time curves. After the test, each actuator automatically resets, and the measurement and control software automatically generates a test report containing key parameters, graphs, and performance conclusions based on the collected data.

[0046] 4.1 Maximum air pressure: 1.4 MPa 4.2 Maximum oil pressure: 15MPa 4.3 Maximum thrust per side: 100 kN 4.4 Maximum thrust of the air chamber: 50KN 4.5 Expander displacement range: 100mm 4.6 Air chamber movement range: 100mm 4.7 Maximum pressure of hydraulic system: 15MPa The expander performance test bench of this invention is a novel test bench developed to meet the development requirements of high efficiency and lightweight wedge brakes in current heavy-duty vehicle braking systems, and to test the output characteristics and expansion performance of their expanders. This invention utilizes a multi-specification, highly adaptable, universal, universally applicable, and rapidly adjustable test fixture. With instantaneous response speed, it completes tests on the thrust and displacement of the expander brake chamber under pneumatic and hydraulic combined operating conditions; expander assembly return performance testing; and pressure holding and sealing performance testing of the hydraulic brake wheel cylinder. It is currently the first expander performance testing bench in China with high precision, synchronous measurement, rapid adaptation, system integration, intelligent control, and safety and reliability. This test bench is suitable for testing the expansion force performance, type testing, and scheme testing of expanders in heavy-duty truck braking systems. It has a very urgent development need and driving effect on improving the testing technology, R&D level, production process quality control, and end-point driving safety of the brake industry.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. All equivalent structural changes made based on the description and drawings of the present invention should be included within the scope of patent protection of the invention. Contents not described in detail in this invention are prior art.

Claims

1. A test bench for testing the performance of an expander, characterized in that: It includes a base platform (3), a left force measuring base (28), a right force measuring base (29), an expander fixing base (30), a gas-liquid pressurization system, a sensor system, a safety protective cover (32), and a measurement and control system; The left force measuring base (28) and the right force measuring base (29) have the same structure and are arranged symmetrically. They are driven by the left electric cylinder (10) and the right electric cylinder (11) to move along the slide rail one (6) and slide rail two (7) set on the base platform (3); The expander fixing base (30) is located between the left force measuring base (28) and the right force measuring base (29), and its upper part is provided with a transition flange and a clamping device for installing the expander (1) and the brake air chamber (2); the gas-liquid booster system includes a gas-liquid booster cylinder and a manual switching valve for providing pneumatic and hydraulic test power; The sensor system includes a left force sensor (12), a left displacement sensor (14), a right force sensor (13), and a right displacement sensor (15) respectively disposed on the left force measuring base (28) and the right force measuring base (29), and a force sensor (21) and a displacement sensor (22) disposed on the expander fixing base (30). The safety shield (32) is composed of profile parts, is set on the base platform (3), covers the entire test section, and includes a shield door (33) and a magnetic buckle (34), and has a safety interlock function; The measurement and control system includes an industrial computer and a data acquisition card, which are used to control the test process, acquire sensor data, and generate test reports.

2. The basic platform for testing the performance of the expander according to claim 1, characterized in that: The left force measuring base (28) and the right force measuring base (29) respectively include a left bearing arm (4), a right bearing arm (5), a left cylinder (8), and a right cylinder (9); the extended ends of the left cylinder (8) and the right cylinder (9) pass through the left bearing arm (4) and the right bearing arm (5), and are detachably connected to the ends of the left transition plate (25) and the right transition plate (26).

3. The expander performance testing bench according to claim 2, characterized in that: The bottom of the left transition plate (25) and the right transition plate (26) cooperate with the slide rail one (6) and slide rail two (7) on the base platform (3) to achieve linear sliding; the ends of the left transition plate (25) and the right transition plate (26) are provided with a left pull plate (16) and a right pull plate (17), which cooperate with the left displacement sensor (14) and the right displacement sensor (15) to measure displacement.

4. The expander performance testing bench according to claim 3, characterized in that: The expander fixing base (30) is provided with a bearing arm (18), the bottom of which is slidably connected to the base platform (3) through slide rail three (19) and slide rail four (20); the bearing arm (18) is provided with a force sensor (21) and a displacement sensor (22), and the displacement sensor (22) is connected to the brake air chamber (2) through a pull plate (23).

5. The expander performance testing bench according to claim 4, characterized in that: The distance adjustment device (31) includes a left electric cylinder (10), a right electric cylinder (11) and a locking mechanism for multiple lead screws (24); the locking mechanism for the lead screws (24) includes multiple lead screws (24) and locking nuts (27) located between the left bearing arm (4) and the right bearing arm (5), which are used to lock the left force measuring base (28) and the right force measuring base (29) after the position is adjusted.

6. The expander performance testing bench according to claim 5, characterized in that: The outer sides of the left bearing arm (4) and the right bearing arm (5) are connected to the extended ends of the left electric cylinder (10) and the right electric cylinder (11) respectively, and the bottom of the left bearing arm (4) and the right bearing arm (5) slides on the top of the foundation platform (3).

7. The expander performance testing bench according to claim 6, characterized in that: The left cylinder (8) and the right cylinder (9) are thin cylinders. The left cylinder (8) and the right cylinder (9) press the left transition plate (25) and the right transition plate (26) against the expander (1). When the brake returns to its original position, the simulated return spring causes the push rods at both ends of the expander (1) to return to their original position. When the expander (1) is reset, the left cylinder (8) and the right cylinder (9) push out to reset the top seat of the expander (1) together with the expander (1). At the same time, the left displacement sensor (14) and the right displacement sensor (15) provide feedback on the displacement.

8. The expander performance testing bench according to claim 7, characterized in that: The bottom of the support arm (18) slides on the top of the foundation platform (3); the support arm (18) slides linearly in the slide rail three (19) and slide rail four (20); a force sensor (21) and a displacement sensor (22) are set at the connection between the expander (1) and the brake chamber (2); a pull plate two (23) is set at the front end of the expander (1), and the displacement sensor two (22) is set between the brake chamber (2) and the pull plate two (23) to detect the output force and displacement of the brake chamber (2) under a certain air pressure.

9. The expander performance testing bench according to claim 8, characterized in that: The test bench base is provided with a detachable safety cover (32). The safety cover (32) is assembled from profiles and covers the entire equipment base platform (3). It plays a safety protection role during the test. The safety cover (32) is provided with four pairs of opening and closing protective doors (33). The closing part of the protective door (33) is provided with a magnetic buckle (34). After the equipment is ready, the four pairs of protective doors (33) are closed and the magnetic buckle (34) is attracted together, and the test can begin. If any pair of protective doors (33) is opened during the test, the magnetic buckle will be separated and the equipment will immediately stop the test automatically, which plays an interlocking protection function.

10. The method for implementing the expander performance testing bench according to claim 1, characterized in that: Includes the following steps: First, install and fix the expander and brake chamber to be tested onto the support arm. Then, open the measurement and control software, input the corresponding preset test parameters in the parameter input interface, check whether the equipment installation and preset parameters are correct, close the protective door of the safety guard, and click "Start Test". Subsequently, the preset parameters are entered into the data acquisition card, and the signal is sent to the cylinder and electric cylinder to be controlled through the data acquisition card. After the test starts, the measurement and control system first controls the left and right electric cylinders to synchronously drive the left and right force measuring bases to move towards each other along slide rail one and slide rail two to the preset displacement. Then, tighten the locking nuts on the multiple screws connected between the left and right support arms to firmly lock the entire force measuring mechanism and ensure the rigidity of the test system. According to the preset test mode, the gas-liquid pressurization system starts to work: if a pneumatic test is to be performed, the set air pressure is input into the brake chamber. For hydraulic testing, the air circuit is introduced into the air-hydraulic booster cylinder via a switching valve to generate high-pressure hydraulic oil, which is then delivered to the hydraulic brake chamber. Under pressure, the push rod of the brake chamber extends outwards, its end directly acting on a force sensor to measure the output thrust in real time. Simultaneously, a displacement sensor, driven by a pull plate, records the push rod displacement in real time. Meanwhile, driven by the thrust of the air chamber, the expander's left and right push rods push the left and right transition plates along the slide rails. The left and right force sensors directly measure the output thrust on both sides of the expander, while the left and right displacement sensors monitor the push rod extension displacement in real time via the left and right pull plates, achieving synchronous and accurate acquisition of thrust and displacement. After a single loading test, the system releases pressure, and the left and right cylinders extend, pushing the left and right transition plates and the expander push rods back to their original positions, simulating the return process during actual braking. The displacement sensors monitor the smoothness and completeness of the return process throughout. entire During the process, if any equipment malfunctions, safety accidents occur, or the test needs to be terminated, the test can be paused by pressing the emergency stop button on the measurement and control software interface; all sensor signals are transmitted to the data acquisition card in real time, and the measurement and control software synchronously displays and records the thrust-displacement curve and pressure-time curve data; after the test, each actuator automatically resets, and the measurement and control software automatically generates a test report containing key parameters, curves and graphs, and performance conclusions based on the collected data.

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