Test device for linear actuators

Abstract

The utility model belongs to robot spare part test technical field, concretely relates to a testing arrangement of linear actuator. When testing, the linear actuator (100) to be measured is fixed on first adapter (21) and second adapter (411) respectively at both ends. The measuring and controlling instrument (5) drives servo motor (3) to drive mobile seat (41) to move, and exerts pushing force or pulling force on the linear actuator (100) to be measured. At this time, the tension and compression force sensor (2) feeds back the stress signal to the measuring and controlling instrument (5), and the measuring and controlling instrument (5) analyzes the performance of the linear actuator (100) according to the preset program. In this way, the load simulation of the linear actuator (100) to be tested in the movement process, the real-time monitoring of the pushing and pulling force and the closed-loop test of the action control are realized, and the automation degree and the precision of the test are improved.

Description

Technical Field

[0001] This utility model belongs to the field of robot component testing technology, specifically relating to a testing device for a linear actuator. Background Technology

[0002] Linear actuators (such as electrically driven push rods and electric cylinders) are widely used in robotics, aerospace, automotive industries, and automation equipment. To ensure the reliability and accuracy of linear actuators in actual operation, their push-pull force, displacement accuracy, response speed, and load characteristics are usually rigorously tested before leaving the factory or during regular maintenance.

[0003] In existing technologies, some testing devices have introduced hydraulic or pneumatic pressurization systems. However, traditional hydraulic or pneumatic loading methods have slow response speeds, making it difficult to simulate complex dynamic load conditions. Furthermore, their control accuracy is poor in the small force range, which cannot meet the testing requirements of high-precision actuators. Utility Model Content

[0004] In view of this, the present invention proposes a testing device for linear actuators, which aims to improve the efficiency of testing linear actuators and the accuracy of test results.

[0005] The testing device for linear actuators provided by this utility model includes an operating table, a tension / compression sensor, a servo motor, a linear motion mechanism, and a measuring and control instrument. The operating table has a first support at one end of its top surface and a second support at the other end. The tension / compression sensor is mounted on the first support and axially connected to a first adapter, which is adapted to connect one end of the linear actuator to be tested. The servo motor is mounted on the second support. The linear motion mechanism includes a movable base, which is configured to move linearly under the drive of the servo motor. A second adapter is mounted on the movable base, adapted to connect the other end of the linear actuator to be tested. The measuring and control instrument is signal-connected to the servo motor and the tension / compression sensor, and has a communication interface for connecting to the linear actuator to be tested.

[0006] Thus, by incorporating tension and compression sensors, a servo motor-driven linear motion mechanism, and an integrated measurement and control instrument, closed-loop testing of the linear actuator under test—including load simulation, real-time monitoring of push and pull forces, and motion control—was achieved. The testing device features a rational structural layout, allowing for rapid loading of the test piece using the first and second adapters, demonstrating strong versatility. Furthermore, the communication interface enables synchronous acquisition and analysis of test data, improving the automation and accuracy of the testing process.

[0007] In a preferred embodiment of the testing device provided by this utility model, the linear motion mechanism further includes a base, a set of guide rails, a lead screw, and an internal threaded sleeve. The base includes a pad and an intermediate support. The pad is disposed on the operating table and connected to the lower end of the second support and the lower end of the intermediate support. A set of guide rails is arranged on the top surface of the pad, and the movable seat is slidably disposed on it. The lead screw is arranged parallel to the set of guide rails, and its two ends are rotatably supported on the intermediate support and the second support, respectively, with one end also connected to the output shaft of the servo motor. The internal threaded sleeve is sleeved on the lead screw and engages with the lead screw threaded transmission, and its outer wall is connected to the movable seat.

[0008] Thus, by employing a threaded transmission method of "lead screw + internal threaded sleeve" in conjunction with guide rail guidance, the rotational motion of the servo motor is precisely converted into the linear displacement of the moving seat. This structure features smooth transmission, high positioning accuracy, and strong load-bearing capacity, ensuring stable linear load or displacement compensation for the linear actuator during testing and reducing testing errors caused by vibration or mechanical backlash.

[0009] In a preferred embodiment of the testing device provided by this utility model, the testing device further includes a grating ruler and a reading head. The grating ruler is disposed on one side of the movable base; the reading head is disposed on the pad and faces the grating ruler, and the reading head is also connected to the measuring and control instrument for signal transmission.

[0010] Thus, a high-precision displacement detection system is constructed using a grating ruler and a reading head, enabling real-time feedback of the absolute position or stroke change of the moving seat (i.e., the output end of the linear actuator). Combined with a servo motor drive system, it allows for precise calibration of the linear actuator's stroke accuracy and eliminates backlash errors in the mechanical transmission chain.

[0011] In a preferred embodiment of the testing device provided by this utility model, the testing device further includes a baffle and multiple photoelectric sensors. The baffle is connected to the other end of the movable base; the multiple photoelectric sensors are disposed on the pad and configured to trigger a detection signal when the baffle moves with the movable base to a position corresponding to the photoelectric sensor; and the photoelectric sensors are also connected to the measuring and controlling instrument.

[0012] In this way, by using the baffle to trigger multiple photoelectric sensors, the device is provided with multiple protections, including travel limit and position sensing. This not only prevents the moving seat from exceeding its safe range and causing mechanical collisions, but also serves as a detection signal for the reference origin or specific travel nodes, improving the safety of the testing process.

[0013] In a preferred embodiment of the testing device provided by this utility model, the testing device further includes a mounting rail, a nut, and a positioning component. The mounting rail is disposed on the pad, the nut is secured to the inner side of the mounting rail and can move along the length of the mounting rail; the positioning component is equipped with a corresponding photoelectric sensor, and the photoelectric sensor is fixed at a certain position on the mounting rail by bolting it to the nut.

[0014] In this way, through the cooperation of the mounting rail, nut, and positioning components, the position of the photoelectric sensor can be flexibly adjusted and fixed along the guide rail. This allows the testing device to adapt to linear actuators of different lengths and stroke ranges, enhancing the equipment's compatibility and applicability.

[0015] In a preferred embodiment of the testing device provided by this utility model, an end cap is formed at one axial end of the internal threaded sleeve, and an axial mounting portion is formed at one end of the movable seat, with the end cap connected to the axial mounting portion.

[0016] Thus, the connection between the end cap and the axial mounting part makes the force transmission between the internal threaded sleeve and the moving seat more direct and conforms to the axial force characteristics. This connection method simplifies the assembly process, enhances the structural strength of the connection part, and ensures that the connection does not loosen during frequent reciprocating tests.

[0017] In a preferred embodiment of the testing device provided by this utility model, the testing device further includes a coupling seat and a coupling. One end of the coupling seat is connected to the second support, and the other end is connected to the servo motor. The coupling is disposed in the coupling seat, and one axial end of the coupling is connected to the output shaft of the servo motor, and the other end is connected to the lead screw.

[0018] In this way, the coupling housing provides a stable mounting space for the coupling, which can effectively absorb coaxiality deviations and minor vibrations between the servo motor output shaft and the lead screw. This avoids damage to the motor bearings and lead screw by radial forces, extends the service life of the transmission system, and ensures smooth motion transmission.

[0019] In a preferred embodiment of the testing device provided by this utility model, the testing device further includes a set of sliding rods and a protective cover. The set of sliding rods is disposed on both sides of the top surface of the operating table and parallel to the moving direction of the movable seat; at least one slider is connected to the bottom ends of both sides of the protective cover, and the slider is slidably disposed on the corresponding sliding rod.

[0020] Thus, the protective cover that can move along the sliding rod achieves physical isolation and protection of the test area. While ensuring the safety of operators (preventing pinching injuries or foreign object splashes), the sliding design facilitates the loading, unloading, and maintenance of the test piece, balancing safety and ease of operation.

[0021] In a preferred embodiment of the testing device provided by this utility model, the protective cover is made of transparent material or has multiple observation slits.

[0022] Thus, the transparent material or observation slit design allows operators to observe the internal testing status and the operation of the linear actuator in real time even with the protective cover closed. This facilitates the timely detection of phenomena such as oil leaks, smoke, or abnormal vibrations without interrupting testing or damaging the protective environment.

[0023] In a preferred embodiment of the testing device provided by this utility model, the first adapter is provided with a connecting rod and a hinge joint. The connecting rod passes through the tension and compression sensor and is connected to one end of the linear actuator.

[0024] Thus, by connecting to the linear actuator via a hinged joint, non-axial misalignment forces (lateral forces) that may exist during the extension and retraction of the linear actuator can be automatically compensated. This flexible connection method ensures that the force values ​​collected by the tension and compression sensors are entirely effective forces along the actuator's axial direction, significantly improving the accuracy of the test data. Attached Figure Description

[0025] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the above and other features and advantages of the present invention, in which:

[0026] Figure 1 This is a schematic diagram of the external structure of the test device in this embodiment.

[0027] Figure 2 This is a schematic diagram of the internal structure of the testing device in this embodiment.

[0028] Figure 3 This is a schematic diagram of the connection structure of the linear actuator in this embodiment.

[0029] Figure 4 This is a schematic diagram of the signal connection relationship of the test device in this embodiment.

[0030] Figure 5 This is a schematic diagram of the structure of the first adapter of the testing device in this embodiment.

[0031] Figure 6 This is a schematic diagram of the linear movement mechanism of the testing device in this embodiment.

[0032] Figure 7 This is a schematic diagram of the connection structure between the movable base and the internal threaded sleeve of the test device in this embodiment.

[0033] Figure 8 This is a schematic diagram showing the cooperation relationship between the grating ruler and the reading head of the testing device in this embodiment.

[0034] Figure 9 This is a schematic diagram showing the position of the photoelectric sensor in the test device of this embodiment.

[0035] The accompanying figure is labeled as follows:

[0036] 100-Linear Actuator;

[0037] 1-Control panel; 11-First support; 12-Second support; 121-Coupling seat;

[0038] 2-Tension / compression sensor; 21-First adapter; 211-Connecting rod; 212-Hinge joint;

[0039] 3-Servo motors;

[0040] 4-Linear movement mechanism; 41-Moving seat; 411-Second adapter; 412-Axial mounting part; 42-Base; 421-Plate; 422-Intermediate support; 43-Guide rail; 44-Lead screw; 45-Internal threaded sleeve; 451-End cap;

[0041] 5-Measurement and control instrument;

[0042] 61-Raster ruler; 62-Reading head; 71-Baffle; 72-Photoelectric sensor; 721-Mounting rail; 722-Nut; 723-Positioning component;

[0043] 8-Coupling;

[0044] 91-Sliding rod; 92-Protective cover; 921-Sliding block. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0046] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "connection" and "setup" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] Furthermore, it should be understood in the description of this application that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0048] This embodiment provides a testing device for a linear actuator 100. Its core purpose is to simulate the load state of the linear actuator 100 (such as an electric push rod, servo electric cylinder, etc.) under actual working conditions, and to comprehensively test its push-pull force, displacement, speed and communication protocol.

[0049] Combination Figure 1 and Figure 2 The core structure of the testing device is built on the operating platform 1. The operating platform 1 serves as the overall support reference, with a first support 11 and a second support 12 fixed at both ends of its top surface. The mechanical circuit during testing is closed with the operating platform 1 through the first support 11 and the second support 12. A tension / compression sensor 2 is installed on the first support 11 to sense the axial force output by the linear actuator 100 under test in real time.

[0050] Combination Figure 2 and Figure 3 The tension / compression sensor 2 is axially connected to a first adapter 21 for locking one end of the linear actuator 100 under test. A servo motor 3 is mounted on the second support 12, providing active load or precise displacement control. The linear motion mechanism 4 is driven by the servo motor 3, and its moving base 41 can reciprocate along a straight line under the guide structure. The moving base 41 is provided with a second adapter 411 for connecting the other end of the linear actuator 100 under test.

[0051] Combination Figure 4The measuring and control instrument 5 is the brain of the device. It not only connects to the servo motor 3 to control its torque or position, but also connects to the tension and compression sensor 2 to collect force data. At the same time, the measuring and control instrument 5 is equipped with a dedicated communication interface (such as CAN, RS485 or Ethernet interface) to directly interact with the controller built into the linear actuator 100 under test, thereby realizing synchronous comparison between control commands and actual physical feedback.

[0052] During testing, the two ends of the linear actuator 100 under test are fixed to the first adapter 21 and the second adapter 411, respectively. The test and control instrument 5 drives the servo motor 3 to move the moving base 41, applying a pushing or pulling force to the linear actuator 100 under test. At this time, the tension and compression sensor 2 feeds back the force signal to the test and control instrument 5, and the test and control instrument 5 analyzes the performance of the linear actuator 100 according to the preset program.

[0053] Continue to refer to Figure 1 In a preferred embodiment of the testing apparatus of this example, considering the safety of the testing site, the apparatus is equipped with a movable protective cover 92. For example, parallel sliding rods 91 are provided on both sides of the operating table 1. Multiple sliders 921 are installed on each side of the bottom of the protective cover 92, which are sleeved on the sliding rods 91. In this way, this sliding design allows the protective cover 92 to be easily pushed and pulled like a drawer. When loading workpieces, the protective cover 92 is pushed to one end to avoid obstruction; before the test begins, it is pulled back to cover the test area.

[0054] Preferably, the protective cover 92 can be made of transparent plexiglass, or multiple narrow observation slits can be opened on the metal cover. This allows testers to visually monitor the linear actuator 100 in real time for oil leakage, deformation, or abnormal oscillation while the cover is closed and secure.

[0055] Combination Figure 3 and Figure 5 In the force test of the linear actuator 100, axial alignment is crucial. For example, the first adapter 21 consists of a connecting rod 211 and a hinge joint 212. The connecting rod 211 is fixed by passing through the central hole of the tension / compression sensor 2, and its end is provided with the hinge joint 212. The hinge joint 212 can be hinged to the lug or connector of the linear actuator 100 under test via a pin.

[0056] Thus, the hinged design allows the linear actuator 100 under test to have a small degree of rotational freedom during the test. If the linear actuator 100 oscillates slightly due to installation errors during extension or retraction, the hinged structure can automatically release lateral stress, ensuring that all forces pass completely through the axis of the tension / compression sensor 2, thereby obtaining the purest axial force test data.

[0057] Combination Figure 2 and Figure 6To ensure high precision and stability of movement during testing, the linear motion mechanism 4 adopts a scheme of lead screw 44 transmission and guide rail 43 guidance.

[0058] The base 42 includes a pad 421 and an intermediate support 422. The pad 421 is laid on the operating table 1 as a precision reference surface for linear motion. The second support 12 and the intermediate support 422 are located at opposite ends of the pad 421, jointly supporting the lead screw 44. A set (usually two) of parallel guide rails 43 are arranged on the top surface of the pad 421, and the movable seat 41 is mounted on the guide rails 43 via a slider 921. This multi-guide rail design can effectively counteract lateral forces during the test, ensuring that the movable seat 41 has only axial freedom. The lead screw 44 is set parallel to the guide rails 43. One end of the lead screw 44 is supported by a bearing in the second support 12 and connected to the servo motor 3, while the other end is supported by the intermediate support 422. An internal threaded sleeve 45 (such as a ball screw nut) is fitted onto the lead screw 44. When the servo motor 3 rotates, the lead screw 44 rotates, causing the internal threaded sleeve 45 to translate axially, thereby driving the movable seat 41 connected to it to move.

[0059] Thus, the linear motion mechanism 4 is constructed to convert rotary motion into linear motion with high thrust, which has the advantages of constant transmission ratio and high positioning accuracy, and can simulate complex dynamic load curves.

[0060] In a preferred embodiment of the testing device in this example, the connection parts are reinforced to address the characteristics of high frequency and high load during the testing process.

[0061] For example, combining Figure 7 One end of the internal threaded sleeve 45 is machined with a flange-shaped end cap 451, and the movable seat 41 has an axial mounting part 412. The end cap 451 is fastened to the axial mounting part 412 by bolts. This design increases the force-bearing contact area and prevents thread damage or loosening due to stress concentration during long-term push-pull cycles.

[0062] For example, continue to refer to Figure 6 The servo motor 3 is connected to the second support 12 via a coupling 121. The coupling 121 contains a coupling 8, one end of which is connected to the motor shaft, and the other end to the lead screw 44. The coupling 8 compensates for the coaxiality deviation between the motor shaft and the lead screw 44, thus protecting the motor bearings and reducing operating noise.

[0063] Continue to refer to Figure 8In one modified embodiment, the testing device can incorporate a closed-loop displacement detection system. This system includes a high-precision grating ruler 61 mounted on one side of the movable base 41, and a reading head 62 mounted at a corresponding position on the pad 421. The reading head 62 faces the grating ruler 61. When the movable base 41 moves, the reading head 62 reads the grating displacement using optical principles and transmits a pulse signal back to the measuring and control instrument 5 in real time.

[0064] Thus, compared to calculating displacement through a motor encoder, the grating ruler 61 directly measures the physical position of the moving seat 41, eliminating errors caused by the transmission backlash and thermal deformation of the lead screw 44, and achieving micron-level measurement accuracy.

[0065] Continue to refer to Figure 9 To prevent overtravel collisions during testing, the device is equipped with a photoelectric limit system. For example, a baffle 71 can be connected to the other side of the moving base 41. Multiple photoelectric sensors 72 are arranged on the pad 421 along the travel direction. Thus, when the moving base 41 reaches its limit position or a predetermined sampling point, the baffle 71 blocks the light path of the photoelectric sensor 72, generating a trigger signal and sending it to the measurement and control instrument 5. Upon receiving the signal, the measurement and control instrument 5 can perform emergency braking or automatic return to zero operation.

[0066] Furthermore, to accommodate actuators of different specifications, the position of the photoelectric sensor 72 is designed to be adjustable. By setting a mounting rail 721 on the pad 421, and utilizing the nut 722 locked within the rail in cooperation with the positioning element 723, the operator can simply loosen the bolts to slide the photoelectric sensor 72 along the rail, and finally lock it at any position. This greatly improves the equipment's compatibility with products of different strokes.

[0067] It should be understood that although this specification is described according to various embodiments, not every embodiment or implementation method contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0068] The above descriptions are merely illustrative embodiments of this application and are not intended to limit the scope of the embodiments of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the embodiments of this application should fall within the protection scope of the embodiments of this application.

Claims

1. A testing device for a linear actuator (100), characterized in that, include: The operating table (1) has a first support (11) at one end of its top surface and a second support (12) at the other end; A tension / compression sensor (2) is mounted on the first support (11) and is axially connected to a first adapter (21), which is configured to connect one end of a linear actuator (100) to be tested. A servo motor (3) is mounted on the second support (12); A linear motion mechanism (4) includes a movable base (41), and the linear motion mechanism (4) is configured such that the movable base (41) moves in a straight line under the drive of the servo motor (3), and a second adapter (411) is provided on the movable base (41), the second adapter (411) being adapted to connect to the other end of the linear actuator (100) to be tested; The measuring and control instrument (5) is connected to the servo motor (3) and the tension and compression sensor (2) and is provided with a communication interface for connecting to the linear actuator (100) to be tested.

2. The testing apparatus according to claim 1, characterized in that, The linear motion mechanism (4) further includes: The base (42) includes a pad (421) and an intermediate support (422). The pad (421) is disposed on the operating table (1) and the pad (421) is connected to the lower end of the second support (12) and the lower end of the intermediate support (422). A set of guide rails (43) are arranged on the top surface of the pad (421), and the movable seat (41) is slidably disposed thereon; The lead screw (44) is set parallel to the set of guide rails (43), and its two ends are rotatably supported on the intermediate support (422) and the second support (12) respectively, and one end is also connected to the output shaft of the servo motor (3); An internal threaded sleeve (45) is fitted on the lead screw (44) and engages with the lead screw (44) in threaded transmission, and its outer wall is connected to the movable seat (41).

3. The testing apparatus according to claim 2, characterized in that, Also includes: A grating ruler (61) is disposed on one side of the movable base (41); The reading head (62) is mounted on the pad (421) and faces the grating ruler (61), and the reading head (62) is also connected to the measuring and control instrument (5) via signal.

4. The testing apparatus according to claim 2, characterized in that, Also includes: A baffle (71) is connected to the other end of the movable seat (41); Multiple photoelectric sensors (72) are disposed on the pad (421) and configured to trigger a detection signal when the baffle (71) moves with the movable seat (41) to the position corresponding to the photoelectric sensor (72), and the photoelectric sensor (72) is also connected to the measuring and control instrument (5) via signal connection.

5. The testing apparatus according to claim 4, characterized in that, Also includes: Mounting rail (721) is provided on the pad (421); The nut (722) is engaged inside the mounting rail (721) and can move along the length of the mounting rail (721); The positioning component (723) is equipped with the corresponding photoelectric sensor (72), and the photoelectric sensor (72) is fixed at a certain position on the mounting rail (721) by bolting the nut component (722).

6. The testing apparatus according to claim 2, characterized in that, An end cap (451) is formed at one axial end of the internal threaded sleeve (45), and an axial mounting portion (412) is formed at one end of the movable seat (41). The end cap (451) is connected to the axial mounting portion (412).

7. The testing apparatus according to claim 2, characterized in that, Also includes: A coupling seat (121) is connected at one end to the second support (12) and at the other end to the servo motor (3); A coupling (8) is disposed in the coupling seat (121), and one end of its axial direction is connected to the output shaft of the servo motor (3), and the other end is connected to the lead screw (44).

8. The testing apparatus according to claim 1, characterized in that, Also includes: A set of slide bars (91) are provided on both sides of the top surface of the operating table (1) and are parallel to the moving direction of the moving seat (41); The protective cover (92) has at least one slider (921) connected to the bottom of each of its two sides, and the slider (921) is slidably mounted on the corresponding slider (91).

9. The testing apparatus according to claim 8, characterized in that, The protective cover (92) is made of transparent material or has multiple observation slits.

10. The testing apparatus according to claim 1, characterized in that, The first adapter (21) is provided with a connecting rod (211) and a hinge joint (212). The connecting rod (211) passes through the tension and compression sensor (2) and is connected to one end of the linear actuator (100).

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