A shock absorber double size detection device

Abstract

The utility model belongs to automobile parts detection device technical field, concretely is a kind of shock absorber double size detection device, including rack, lifting mechanism, cantilever, first driving part, second driving part, first detection tool, second detection tool, first displacement sensor and second displacement sensor, first driving part and second driving part are respectively arranged on the cantilever, first detection tool is connected with the output end of first driving part, first detection tool can resist and press shock absorber piston rod top end face, for cooperation collection shock absorber free length, second detection tool is connected with the output end of second driving part, for cooperation collection shock absorber height after sealing.The utility model can complete the data acquisition of two groups of key sizes of shock absorber free length and height after sealing in the same station, workpiece does not need to be transported to other station, greatly compresses single product overall detection beat, effectively improves the overall detection efficiency of production line.

Description

Technical Field

[0001] This utility model belongs to the technical field of automotive parts testing devices, specifically relating to a dual-size testing device for shock absorbers. Background Technology

[0002] After the sealing process of the automotive shock absorber is completed, the two core dimensions of the shock absorber, namely the free length and the height after sealing, are directly related to the sealing reliability and assembly matching degree of the shock absorber. If either dimension is out of tolerance, it will cause quality defects such as assembly interference, abnormal damping performance, or oil leakage and abnormal noise. Therefore, both dimensions need to be accurately inspected and controlled.

[0003] Currently available conventional vibration damper height detection equipment has limited functionality, capable of measuring only a single height dimension at a time. It cannot simultaneously collect the free length and sealed height of the vibration damper at the same workstation. During production, this necessitates splitting the measurement process into two independent steps, significantly lengthening the inspection cycle for each piece. This makes it difficult to match the pace of high-speed, continuous production on automated assembly lines. Furthermore, the segmented inspection method struggles to achieve 100% online coverage of all workpieces on the assembly line, typically relying on manual sampling. This method is highly susceptible to missing defective parts that may flow into downstream assembly processes, ultimately leading to mass rework or parts scrap, and significantly increasing manufacturing costs for enterprises. Utility Model Content

[0004] The purpose of this utility model is to provide a dual-dimensional inspection device for shock absorbers, so as to solve the problem that the existing shock absorber inspection equipment can only measure a single height dimension at a time, and cannot complete the dual-dimensional inspection of the free length and the height after sealing of the shock absorber at the same workstation. The process splitting leads to a long inspection cycle and makes it impossible to achieve 100 inspections on the production line.

[0005] To achieve the above objectives, this utility model proposes a dual-size detection device for vibration dampers, comprising: frame; A lifting mechanism is mounted on the frame; A cantilever is located at the output end of the lifting mechanism and is driven by the lifting mechanism to move in the vertical direction; The first driving component and the second driving component are respectively fixedly installed on the cantilever; The first detection fixture is connected to the output end of the first drive component. The first detection fixture can press against the top end face of the piston rod of the shock absorber to collect the free length of the shock absorber. The second testing fixture is connected to the output end of the second drive component. The second testing fixture can move horizontally with the second drive component to the top of the shock absorber cylinder so that when the lifting mechanism drives the cantilever downward, the second testing fixture can press against the upper end face of the shock absorber sealing step to collect the height of the shock absorber after sealing. A first displacement sensor is disposed on a first detection fixture and is used to collect the vertical displacement of the first detection fixture relative to the cantilever. The second displacement sensor is installed on the second detection fixture and is used to collect the vertical displacement of the second detection fixture relative to the cantilever.

[0006] Optionally, the lifting mechanism is a screw drive mechanism, including a screw and a slider slidably mounted on the screw, and the cantilever is fixedly mounted on the slider.

[0007] Optionally, the first driving component is a vertically arranged first cylinder, and the first detection fixture is fixedly connected to the end of the piston rod of the first cylinder.

[0008] Optionally, the second driving component is a second cylinder arranged laterally, the piston rod of the second cylinder extends and retracts in the horizontal direction, the second detection fixture is fixed to the end of the piston rod of the second cylinder, and the second cylinder is used to drive the second detection fixture to move horizontally above the cylinder of the shock absorber.

[0009] Optionally, the lifting mechanism is equipped with a servo motor, which is poweredly connected to the lead screw transmission mechanism via a coupling.

[0010] Optionally, the first displacement sensor and the second displacement sensor are resistance rulers or optical grating rulers.

[0011] Optionally, the first cylinder is fixedly mounted on the cantilever, and the extension and retraction direction of the first cylinder is in the same direction as the movement direction of the cantilever.

[0012] Optionally, the second cylinder is fixedly mounted on the cantilever, and the extension and retraction direction of the second cylinder is perpendicular to the movement direction of the cantilever.

[0013] Optionally, the lead screw is fixedly arranged inside the frame in a vertical direction, and the two ends of the lead screw are respectively rotatably limited by the upper and lower ends of the frame.

[0014] Optionally, the first and second testing fixtures are arranged side by side at intervals along the transverse direction of the cantilever.

[0015] The aforementioned dual-size inspection device for vibration dampers integrates two independent inspection fixtures on the same cantilever and equips each fixture with a displacement sensor. After the lifting mechanism moves the cantilever to the inspection station, it can collect data on two key dimensions of the vibration damper: the free length and the height after sealing. This significantly reduces the overall inspection cycle of a single product and effectively improves the overall inspection efficiency of the production line.

[0016] The entire set of equipment integrates dual-dimensional detection functions, which can follow the production line to complete the free length and height measurement of each shock absorber after sealing, truly realizing 100% online full inspection of production line workpieces. It eliminates the hidden dangers of missed inspection caused by manual sampling from the hardware structure level, reduces the problem of batch scrap caused by defective dimensions flowing into the later process, reduces production losses and rework costs, and perfectly adapts to the mass production operation needs of automated continuous production lines for automotive parts. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a three-dimensional schematic diagram of the dual-size detection device for the shock absorber in one embodiment of the present invention; Figure 2 This is a side view of the dual-size detection device for the shock absorber in one embodiment of the present invention. Figure 3 for Figure 2 Enlarged view of a portion of point A in the middle; Figure 4 This is a schematic diagram of the assembly of the complete testing production line in one embodiment of the present invention.

[0019] In the diagram: 1. Frame; 2. Lifting mechanism; 3. Cantilever; 4. First cylinder; 5. Second cylinder; 6. Servo motor; 7. Coupling; 8. First inspection fixture; 9. First resistance gauge; 10. Second inspection fixture; 11. Second resistance gauge. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] The preferred embodiments described below are merely examples, and other obvious variations will be apparent to those skilled in the art. The basic principles of this invention as defined in the following description can be applied to other implementations, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of this invention.

[0022] Those skilled in the art should understand that, in the disclosure of this utility model, the terms "longitudinal," "lateral," "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. They are only for the convenience of describing this utility model 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. Therefore, the above terms should not be construed as limitations on this utility model.

[0023] It should be noted that, in this document, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] like Figure 1 and Figure 2 As shown, this embodiment provides a dual-size detection device for vibration dampers, including a frame 1, a lifting mechanism 2, a cantilever 3, a first drive component, a second drive component, a first detection fixture 8, a second detection fixture 10, a first displacement sensor, and a second displacement sensor. The frame 1 is a vertical rigid load-bearing base, vertically fixed next to the detection station on the production line. The lifting mechanism 2 is integrated inside the frame 1, and its power output end performs linear reciprocating motion in the vertical direction. The root of the cantilever 3 is fixedly connected to the output end of the lifting mechanism 2, and moves up and down synchronously with the lifting mechanism 2 in the vertical direction. The first drive component and the second drive component are respectively fixedly installed on the cantilever end of the cantilever 3. The first detection fixture 8 is fixedly connected to the output end of the first drive component. The first detection fixture 8 can press against the top end face of the piston rod of the shock absorber to cooperate in collecting the free length of the shock absorber. The second detection fixture 10 can move horizontally with the second drive component to directly above the cylinder of the shock absorber so that when the lifting mechanism 2 drives the cantilever to descend, the second detection fixture 10 can press against the upper end face of the sealing step of the shock absorber to cooperate in collecting the height of the shock absorber after sealing.

[0025] It should be noted that the height after sealing can refer to the axial height of the sealing step formed by the flange at the end of the cylinder after the cylinder barrel has been sealed and press-fitted.

[0026] The free length refers to the total axial length from the bottom reference surface of the damper to the top end face of the piston rod when the damper is not subjected to external compressive load.

[0027] The first displacement sensor is linked with the first detection fixture 8 to collect the vertical displacement of the first detection fixture 8 relative to the cantilever 3 in real time. The second displacement sensor is linked with the second detection fixture 10 to collect the vertical displacement of the second detection fixture 10 relative to the cantilever 3 in real time. The entire device integrates two independent detection execution units through a single cantilever, which can complete the data acquisition of two core height dimensions of the vibration damper at the same detection station, without the need to separate two independent detection processes. This achieves single-station dual-dimensional detection, meeting the production requirements of 100% online full inspection of workpieces on the assembly line.

[0028] In one embodiment, the first driving member is a vertically arranged first cylinder 4, and the first detection fixture 8 is fixedly connected to the lower end of the piston rod of the first cylinder 4.

[0029] Specifically, the first cylinder 4 adopts a flange-type mounting structure. The upper end of the cylinder body is fixed to the top surface of the cantilever 3 through a mounting flange, and the piston rod extends downward through the pre-fabricated mounting hole of the cantilever 3. The first testing fixture 8 is fixed to the lower end of the piston rod by a threaded locking mechanism with an adapter block. The adapter block has a reserved standard mounting interface, which can quickly replace the appropriate fixture probe according to the shape of different models of shock absorbers.

[0030] In one embodiment, the second driving component is a horizontally arranged second cylinder 5. The piston rod of the second cylinder 5 extends and retracts horizontally. The second detection fixture 10 is fixedly connected to the end of the piston rod of the second cylinder 5. The cylinder body of the second cylinder 5 is fixed to the side wall of the cantilever 3 by a side-mounted bracket. The piston rod reciprocates along the lateral extension direction of the cantilever 3. The second detection fixture 10 is fixed to the front end of the piston rod by a locking screw, with its detection end facing the sealing step surface of the shock absorber. Since the height of the shock absorber after sealing is a stepped dimension inside the assembly, the vertically arranged fixture cannot directly probe for measurement due to the interference of the shock absorber piston rod. The horizontally arranged second cylinder 5 can drive the second detection fixture 10 to move laterally to the top of the rear end face of the shock absorber sealing. The lifting mechanism 2 controls the cantilever 3 to descend, and the second detection fixture 10 contacts the rear end face of the shock absorber sealing for measurement. The height dimension after sealing is obtained by displacement calculation, which solves the problem that the traditional vertical single fixture cannot simultaneously measure the internal step height.

[0031] It should be noted that the second testing fixture 10 is configured in a U-shape on one side relative to the piston rod of the shock absorber, so as to facilitate its movement to the measurement station to measure the height of the shock absorber after sealing.

[0032] Specifically, the lifting mechanism 2 drives the cantilever 3 to move downward as a whole. The first detection fixture 8 moves downward with the cantilever 3 and presses against the top end face of the shock absorber piston rod. At this stage, the compressive force applied by the fixture to the piston rod is less than 200N. This compressive force is insufficient to overcome the internal spring and damping force of the shock absorber. The shock absorber piston rod maintains its original extended position and will not retract downward. Under the reaction force of the shock absorber workpiece, the first detection fixture 8 produces a vertical retraction relative to the cantilever 3. The first displacement sensor collects the vertical displacement of the first detection fixture 8 relative to the cantilever 3. Combined with the position signal output by the lifting mechanism 2, the free length of the shock absorber is calculated. The control system latches the free length measurement result.

[0033] The formula for calculating the free length is: Free length = Standard workpiece length of the damper - Damper calibration reference value + Measured value of the first displacement sensor.

[0034] The length of the standard workpiece for the vibration damper is the length of a standard sample that has been calibrated and measured in advance, and stored in the control system. The calibration reference value for the vibration damper is the system offset compensation amount generated during device assembly, obtained by performing a single test calibration on the standard workpiece, and stored in the control system as a fixed compensation parameter after calibration. The measured value of the displacement sensor is the vertical retraction displacement of the first testing fixture relative to the cantilever, which is collected in real time by the first displacement sensor during the testing of the vibration damper under test. Under the condition that the compressive force is less than 200N, the piston rod of the vibration damper is not compressed, and the free length of the vibration damper under test can be obtained by substituting it into the above formula.

[0035] Furthermore, the calibration reference value is a comprehensive compensation parameter used to compensate for the inherent mechanical offset error of the entire device caused by the cantilever mechanical zero point, the assembly position of the detection tooling, and the installation zero point of the displacement sensor. This offset error cannot be directly collected and read by the sensor.

[0036] Before formally testing the vibration damper under test, a calibration process is performed: a standard workpiece with its true dimensions measured by a metrology instrument is placed at the testing station, and the testing action is performed under a compressive force of less than 200N to obtain the readings of the displacement sensor during calibration. The calibration reference value is then calculated by combining the true measurement value of the standard workpiece with the calibration reference value, and stored in the control system along with the length of the standard workpiece. After the calibration process is completed, during the batch testing of the vibration dampers under test, the length of the standard workpiece and the calibration reference value are known fixed parameters within the control system. During testing, only the measured values ​​of the displacement sensor need to be collected and substituted into the calculation formula to obtain the free length of the vibration damper under test.

[0037] Once the free length value is obtained, the control system immediately latches the measurement result. Throughout the entire process of cantilever lifting and resetting, and subsequent downward movement, the data from the first displacement sensor is no longer read or updated to avoid interference from displacement changes caused by subsequent compression and retraction of the piston rod with the already measured free length result.

[0038] After the free length measurement is completed, the servo motor 6 drives the cantilever 3 to rise back to its original position. The first detection fixture 8 disengages from the top of the piston rod, the compressive force is completely unloaded, and the piston rod remains in a naturally extended state. Subsequently, the servo motor 6 drives the cantilever 3 to feed downwards again, entering the height measurement condition after sealing. At this time, the second cylinder 5 extends and drives the second detection fixture 10 to move laterally, so that the U-shaped part of the second detection fixture fits around the outer circumference of the damper piston rod without interfering with the measurement. The cantilever 3 drives the first detection fixture 8 and the second detection fixture to move downwards synchronously. The compressive force applied to the piston rod by the first detection fixture 8 increases to more than 200N, overcoming the internal damping of the damper and driving the piston rod to retract downwards. This causes the second detection fixture 10 to press against the horizontal upper end face of the sealing step of the damper. Under the action of the workpiece reaction force, the second detection fixture 10 produces a vertical retraction relative to the cantilever 3. The second resistance ruler 11 collects the vertical retraction displacement of the second detection fixture 10 relative to the cantilever 3 in real time and calculates the height of the damper after sealing. The locking force of the station positioning mechanism on the cylinder housing of the shock absorber is greater than 200N, ensuring that the position of the cylinder housing remains fixed during the pressure measurement process.

[0039] The formula for calculating the height after sealing is: Height after sealing = Height after sealing of standard workpiece - Calibration reference value of standard workpiece after sealing + Measured value of second displacement sensor.

[0040] The measured height of the standard workpiece after sealing is pre-stored in the control system, and the calibration reference value of the standard workpiece after sealing is the system offset compensation parameter obtained during calibration. The measured value of the second resistance ruler 11 is the real-time floating and yielding amount of the second detection fixture 10 relative to the cantilever 3 under the condition of detecting the height after sealing. During the measurement process, the cylinder shell is locked in place by the positioning mechanism to keep its position unchanged. The piston rod is an internal moving part of the vibration damper. The downward retraction of the piston rod will not change the spatial position of the sealing step, so it will not interfere with the measurement result of the height after sealing.

[0041] In one embodiment, the lifting mechanism 2 is a screw drive mechanism, including a screw arranged in a vertical direction and a slider threaded onto the screw, and the root of the cantilever 3 is fixedly installed on the side end face of the slider.

[0042] Specifically, the lead screw adopts a ball screw pair, with the screw body arranged along the vertical central axis of the frame 1. A ball nut, matching the external thread of the lead screw, is embedded inside the slider. When the lead screw rotates, the rotational motion is precisely converted into the linear motion of the slider through the ball thread transmission, resulting in small transmission clearance, high positioning accuracy, and strong load-bearing rigidity. The cantilever 3 is fixedly connected to the side of the slider by multiple sets of bolts. The mating surfaces are precision-machined to ensure flatness, ensuring no relative movement between the cantilever 3 and the slider, and allowing it to rise and fall smoothly and synchronously with the slider. Compared to belt drives, rack and pinion drives, and other lifting methods, the lead screw transmission mechanism has stronger transmission rigidity and better resistance to off-center loads. Under continuous vibration conditions in an assembly line, it can maintain a stable motion reference for a long time, and is less prone to detection reference deviation.

[0043] In one embodiment, the lifting mechanism 2 is equipped with a servo motor 6, which is poweredly connected to the lead screw transmission mechanism via a coupling 7. Specifically, the servo motor 6 is vertically fixed on a motor mounting base at the top of the frame 1, with its output shaft facing downwards. The coupling 7 is a diaphragm coupling, with both ends respectively sleeved on the output shaft end of the servo motor 6 and the upper shaft end of the lead screw, and secured with locking screws to achieve synchronous and gapless power transmission. Using the servo motor 6 as the lifting power source, full closed-loop position control can be achieved through its built-in encoder, enabling precise setting of the lifting reference position of the cantilever 3, with positioning accuracy reaching the micrometer level. For different specifications of vibration dampers, only the servo position parameters in the control system need to be modified to switch the detection reference, without adjusting the mechanical structure, adapting to flexible production of multiple varieties. The diaphragm coupling can compensate for a small amount of installation coaxiality error, while also having a certain vibration damping and buffering capacity, reducing the transmission impact of motor vibration on the lead screw transmission accuracy.

[0044] For details, please refer to [link / reference]. Figure 2 and Figure 3 In one embodiment, the first displacement sensor and the second displacement sensor are resistance rulers, namely, the first resistance ruler 9 and the second resistance ruler 11, respectively. They can also be replaced with the first grating ruler and the second grating ruler according to the accuracy requirements.

[0045] Specifically, when using a resistance ruler, the ruler body is fixedly mounted on the side wall of the corresponding cylinder, and the measuring rod end is fixedly connected to the corresponding testing fixture, moving synchronously with the fixture. Displacement values ​​are output in real time through linear changes in resistance. The resistance ruler has a robust structure, strong vibration and impact resistance, and controllable procurement and maintenance costs, making it highly suitable for the complex vibration environment of automotive parts production lines. When higher detection accuracy is required, an optical grating ruler can be used instead. The fixed section of the optical grating ruler is fixed to the mounting base of cantilever 3, while the moving section moves synchronously with the testing fixture, outputting displacement data through differential optical signal transmission. This provides higher detection accuracy and is suitable for high-precision vibration damper testing scenarios. The selection of these two sensor types can be flexibly configured according to production line needs, significantly improving the device's adaptability to various scenarios.

[0046] In one embodiment, the first cylinder 4 is fixedly mounted on the cantilever 3, and the extension and retraction direction of the first cylinder 4 is in the same direction as the overall movement direction of the cantilever 3.

[0047] Specifically, the overall lifting direction of the cantilever 3 is vertical, and the extension and retraction direction of the piston rod of the first cylinder 4 is also vertical, with their axes of motion parallel to each other. During installation, the flatness of the cylinder mounting surface on the cantilever 3 is ensured by precision machining, and positioning pins are used to ensure that the cylinder extension and retraction direction is completely aligned with the lifting reference.

[0048] It should be noted that during the inspection operation, after the piston rod of the first cylinder 4 extends, it remains in an extended and locked state, acting as a fixing mechanism and no longer performing reciprocating extension and retraction movements. The first inspection fixture 8 is fixedly installed at the output end of the piston rod of the first cylinder 4. The core advantage of this unidirectional arrangement is that the cylinder output axis is coaxial with the cantilever lifting reference, which will not generate lateral force. The inspection fixture has no yaw torque during movement, resulting in smoother operation and ensuring the accuracy of displacement acquisition.

[0049] In one embodiment, the second cylinder 5 is fixedly mounted on the cantilever 3, and the extension and retraction direction of the second cylinder 5 is perpendicular to the overall movement direction of the cantilever 3.

[0050] Specifically, the cantilever 3 moves vertically up and down, while the second cylinder 5 moves horizontally forward and backward, with their directions of movement orthogonal at 90°. This orthogonal layout ensures that the movement spaces of the two sets of testing fixtures are completely independent, and their actions do not interfere with each other. Simultaneously, the horizontally arranged cylinder does not occupy the vertical installation space of the cantilever, effectively reducing the overall height of the cantilever, minimizing the center of gravity shift after extension, improving the operational stability of the lifting mechanism 2, and reducing unilateral wear of the lead screw caused by off-center loading.

[0051] In one embodiment, the lead screw is fixedly arranged in the internal cavity of the frame 1 in a vertical direction, and the upper and lower ends of the lead screw are respectively rotatably limited and assembled with the upper and lower inner walls of the frame 1.

[0052] Specifically, an upper bearing seat is fixed to the upper inner wall of frame 1, and a deep groove ball bearing is installed inside. The upper journal of the lead screw passes through the inner ring of the bearing to achieve radial limiting. A lower bearing seat is fixed to the lower inner wall of frame 1, and a combined support structure of thrust ball bearing and deep groove ball bearing is installed inside, which simultaneously bears the radial and axial loads of the lead screw. The two ends of the lead screw achieve bidirectional axial positioning through the shaft shoulder and locking nut, controlling the axial runout of the lead screw to the micrometer level. Through the double rotation limiting structure at both ends, the radial runout and axial runout during the rotation of the lead screw are both limited to a very small range. The reference stability of the entire lifting mechanism 2 is greatly improved, which can effectively resist the impact of continuous vibration of the production line. There will be no drift of the detection reference during long-term continuous operation, ensuring the long-term consistency and accuracy of dimensional detection.

[0053] In one embodiment, the first detection fixture 8 and the second detection fixture 10 are arranged side by side at intervals along the lateral extension direction of the cantilever 3.

[0054] Specifically, two sets of tooling are arranged laterally at the cantilever end of the cantilever, with a safety gap between them to ensure that no structural collision occurs during the extension and repositioning of the tooling, and that each tooling has a completely independent inspection area. The side-by-side, spaced arrangement ensures that the load on the cantilever 3 is evenly distributed laterally, avoiding eccentric deformation of the cantilever caused by concentrated loads on one side. It also makes the force on the lifting slider more balanced, reducing unilateral wear of the lead screw and slider, and extending the service life of the mechanism. In addition, the side-by-side layout concentrates the two inspection stations in the same vertical projection area, allowing the vibration damper to complete two dimensional inspections without lateral displacement, further reducing the single-piece inspection cycle and improving the overall operating efficiency of the production line.

[0055] To facilitate understanding of the embodiments of this solution by those skilled in the art, the working principle of this solution will now be briefly explained in conjunction with specific application scenarios: After the system is powered on and initialized, the operator selects the detection program for the corresponding model of vibration damper and retrieves preset parameters such as servo reference coordinates and dimensional qualification thresholds. If necessary, standard gauge blocks are used to calibrate the resistance ruler, and the calibration reference value, along with the length of the standard workpiece, is recorded and stored in the control system.

[0056] After the shock absorber, having completed the sealing process, is transported to the inspection station via the production line and positioned and clamped, during the inspection preparation stage, the first cylinder 4 engages and locks, establishing a fixed connection between the first inspection fixture 8 and the cantilever 3. The first cylinder 4, acting as a fixed component, no longer performs telescopic drive. The servo motor 6 drives the lifting mechanism 2 to lower the cantilever 3, which in turn drives the first inspection fixture 8, locked by the first cylinder 4, to move downwards synchronously, entering the free length measurement phase. During this phase, the compressive force applied to the piston rod by the first inspection fixture 8 is less than 200N, insufficient to compress the shock absorber, and the piston rod maintains its original position. The first resistance gauge 9 collects the displacement data of the first inspection fixture 8 relative to the cantilever 3 in real time and transmits it to the control system. Through the calculation logic of "free length = standard workpiece length of the shock absorber - shock absorber calibration reference value + actual measured value of the resistance gauge," the free length value of the shock absorber is obtained, and the control system latches this free length measurement result.

[0057] After the free length measurement is completed, the servo motor drives the cantilever 3 to rise back to its original position. The first detection fixture 8 disengages from the top of the piston rod, the compressive force is completely unloaded, and the piston rod remains in a naturally extended state. The second cylinder 5 drives the second detection fixture 10 to move to the piston rod end of the damper. Since one side of the second detection fixture is U-shaped, it will not interfere with the piston rod. The second detection fixture 10 can extend directly above the step to be measured on the damper. Then, the servo motor 6 drives the cantilever 3 to feed downwards again, entering the height measurement condition after sealing. The cantilever 3 drives the first detection fixture 8 and the second detection fixture 10 to move downwards synchronously. The downward movement of the cantilever 3 increases the compressive force applied to the piston rod by the first detection fixture 8 to greater than 200N, overcoming the internal damping of the damper and driving the piston rod to retract downwards. The downward pressure of the cantilever 3 causes the second detection fixture 10 to contact the internal step surface of the damper cylinder. The second resistance ruler 11 collects the displacement data of the second detection fixture 10 relative to the cantilever 3, and obtains the height value of the damper after sealing through the corresponding calculation logic.

[0058] The control system compares two sets of measured dimensions with preset upper and lower acceptable thresholds to automatically determine whether the workpiece is qualified or unqualified. After the inspection is completed, the second cylinder 5 retracts to its initial position, and the cantilever 3 rises to the standby position. Qualified workpieces flow normally to the next process on the production line, and the two sets of dimensional data are simultaneously uploaded to the production management system for archiving, achieving full traceability of single-piece product dimensional data. Unqualified workpieces trigger an abnormal signal, and the production line transfers them to the unqualified product removal area to prevent defective products from flowing into downstream processes.

[0059] In summary, the entire set of dimensional values ​​relies on closed-loop positioning by a servo motor, and then uses a resistance ruler for micro-displacement compensation. Even if the continuous vibration of the production line causes slight elastic deformation of the lead screw and cantilever, the servo coordinates, as the main reference, will not shift overall, and the resistance ruler only compensates for the local expansion and contraction of the tooling. The combination of the two can control the detection error to the micrometer level, solving the pain points of traditional single-sensor equipment such as vibration interference, reference deviation, and false or missed detections. The accuracy remains stable and undiminished during long-term continuous operation.

[0060] When changing to different specifications of vibration dampers, you only need to modify the servo preset reference coordinates (such as 300mm, 400mm, etc.) in the control system, modify the size qualification threshold, and recalibrate the resistance ruler zero point with the corresponding standard parts. The whole process does not require disassembly, grinding, or replacement of testing tooling and mechanical parts, and can quickly switch between multiple vibration dampers for mixed production lines.

[0061] The free length and the height after sealing are calibrated and calculated independently, and the data collected by the two sets of resistance gauges do not interfere with each other. The control system stores the servo reference coordinates, calibration reference values, and the original measured data of the resistance gauges separately. If a dimensional deviation occurs, it can be checked separately whether it is due to servo positioning deviation, resistance gauge zero-point drift, or workpiece dimensional defects, quickly locating the source of the fault. All original collected data are synchronously uploaded to the MES system to form a complete dimensional archive for each part, which facilitates the statistical analysis of dimensional fluctuations and the optimization of front-end assembly and sealing processes.

[0062] This device does not require the cantilever, lead screw, and tooling to be machined to extremely high precision. It relies on software calibration compensation to offset mechanical assembly gaps and machining tolerances, reducing the difficulty of assembling the whole machine. At the same time, the minor wear caused by long-term use can be restored to the detection accuracy by simply recalibrating the zero point of the resistance ruler periodically. This eliminates the need for frequent maintenance and replacement of mechanical parts, significantly reducing equipment maintenance costs.

[0063] Please see Figure 4 , Figure 4 This is a schematic diagram of the overall assembly process of the dual-size detection device for vibration dampers of this utility model integrated into an automated vibration damper production line, which fully demonstrates the cooperative working relationship between this device and the upstream and downstream equipment on the production line and the workpiece positioning and conveying mechanism.

[0064] The entire testing device is fixedly installed in the middle of the production line, downstream of the vibration damper sealing process. The production line is equipped with a continuous workpiece conveying tray, each tray individually carrying one vibration damper that has completed the sealing process. The conveying tray has a built-in lifting and positioning cylinder, which can lift the vibration damper and lock it in place, ensuring that the vibration damper does not shake or tilt during measurement, providing a stable measuring carrier.

[0065] The production line is equipped with a positioning sensor. When the pallet carrying the vibration damper is conveyed to the detection area directly below the device, the positioning sensor sends a positioning signal to the device's PLC control system. The system triggers the detection process, and the servo motor 6 drives the lifting mechanism 2 to lower the cantilever 3 to the preset measurement reference coordinates. The system then collects the free length and the height after sealing of the vibration damper. After the detection is completed, the control system automatically determines whether the workpiece is qualified or unqualified based on the two sets of calculated dimensions: If all the workpiece dimensions are within the standard tolerance range, the system outputs a qualified signal, the conveyor pallet is unlocked, and the vibration damper is normally conveyed to the downstream assembly process. At the same time, the servo reference value, the original displacement data of the resistance ruler, and the final calculated free length and sealing height are automatically uploaded to the workshop MES data terminal to complete the archiving and traceability of single-piece quality data. If any set of dimensions exceeds the qualified threshold, the system triggers a defective product interception signal. When the conveyor pallet flows downstream, it does not perform subsequent pressing and assembly processing actions until the pallet flows to the defective product off-line station at the end of the production line. The system automatically diverts and removes the vibration dampers with out-of-tolerance dimensions, completely preventing defective products from flowing into the finished product process and avoiding batch assembly scrap.

[0066] at the same time Figure 4 The advantages of this equipment layout are clearly demonstrated: This device adopts a vertical, integrated, and compact structure. The cantilever 3 extends laterally directly to the workpiece conveying path, eliminating the need for additional lateral or longitudinal space on the production line. It can be directly installed in existing vibration damper production lines without requiring large-scale modifications to the original conveying equipment, resulting in low installation costs. The entire testing unit is independent of the conveyor tray positioning mechanism, preventing vibrations from the conveyor line from being directly transmitted to the core testing components (frame 1 and lifting mechanism 2), further enhancing the machine's vibration resistance and ensuring long-term stability of the testing benchmark. The entire production line relies on this device to achieve 100% online dual-dimensional inspection of each vibration damper after sealing, abandoning the outdated model of traditional manual sampling and separate measurements in two processes, significantly improving the production efficiency and quality control capabilities of automated production lines.

[0067] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0068] The above-disclosed embodiments are only a few specific examples of the present utility model. However, the embodiments of the present utility model are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present utility model.

Claims

1. A dual-size detection device for vibration dampers, characterized in that, include: frame; A lifting mechanism is mounted on the frame; A cantilever is located at the output end of the lifting mechanism and is driven by the lifting mechanism to move in the vertical direction; The first driving component and the second driving component are respectively fixedly installed on the cantilever; The first detection fixture is connected to the output end of the first drive component. The first detection fixture can press against the top end face of the piston rod of the shock absorber to collect the free length of the shock absorber. The second testing fixture is connected to the output end of the second drive component. The second testing fixture can move horizontally with the second drive component to the top of the shock absorber cylinder so that when the lifting mechanism drives the cantilever downward, the second testing fixture can press against the upper end face of the shock absorber sealing step to collect the height of the shock absorber after sealing. A first displacement sensor is disposed on a first detection fixture and is used to collect the vertical displacement of the first detection fixture relative to the cantilever. The second displacement sensor is installed on the second detection fixture and is used to collect the vertical displacement of the second detection fixture relative to the cantilever.

2. The shock absorber dual-size detection device according to claim 1, characterized in that, The lifting mechanism is a screw drive mechanism, including a screw and a slider slidably mounted on the screw, and the cantilever is fixedly installed on the slider.

3. The shock absorber dual-size detection device according to claim 1, characterized in that, The first driving component is a vertically arranged first cylinder, and the first detection fixture is fixed to the end of the piston rod of the first cylinder.

4. The shock absorber dual-size detection device according to claim 1, characterized in that, The second driving component is a second cylinder arranged laterally. The second detection fixture is fixed to the end of the piston rod of the second cylinder. The second cylinder is used to drive the second detection fixture to move horizontally above the cylinder of the shock absorber.

5. The shock absorber dual-size detection device according to claim 2, characterized in that, The lifting mechanism is equipped with a servo motor, which is connected to the lead screw transmission mechanism via a coupling.

6. The shock absorber dual-size detection device according to claim 1, characterized in that, The first displacement sensor and the second displacement sensor are resistance rulers or optical grating rulers.

7. The vibration damper dual-size detection device according to claim 3, characterized in that, The first cylinder is fixedly mounted on the cantilever, and the extension and retraction direction of the first cylinder is in the same direction as the movement direction of the cantilever.

8. The shock absorber dual-size detection device according to claim 4, characterized in that, The second cylinder is fixedly mounted on the cantilever, and the extension and retraction direction of the second cylinder is perpendicular to the movement direction of the cantilever.

9. The shock absorber dual-size detection device according to claim 2, characterized in that, The lead screw is fixedly arranged inside the frame in a vertical direction, and the two ends of the lead screw are respectively rotatably limited by the upper and lower ends of the frame.

10. The shock absorber dual-size detection device according to claim 1, characterized in that, The first and second testing fixtures are arranged side by side at intervals along the transverse direction of the cantilever.

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