A steering intermediate shaft coaxial degree laser measuring device

Abstract

The application provides a coaxiality laser measuring device for a steering intermediate shaft, and relates to the technical field of laser measurement. The device comprises an electric guide rail, a sleeve, metal balls, a laser displacement sensor, and two V-shaped steel sheets which are mutually inverted and attached. The two V-shaped steel sheets form a light transmission hole in the middle after being crossed. When measuring, the metal balls are attached to the surface of a workpiece to perceive radial fluctuations. When a convex surface is encountered, the laser displacement sensor and the two V-shaped steel sheets are simultaneously moved away from the workpiece, and the two V-shaped steel sheets are simultaneously moved towards each other to make the light transmission hole smaller. When a concave surface is encountered, the laser displacement sensor and the two V-shaped steel sheets are simultaneously moved towards the workpiece, and the two V-shaped steel sheets are simultaneously moved away from each other to make the light transmission hole larger. The laser displacement sensor is directly driven by the metal balls to follow, the optimal working distance is forced to be constant, and the defocus error is eliminated from the root. The light transmission hole is made smaller to block stray light when a convex surface is encountered, and the light transmission hole is made larger to expand the receiving angle and capture intermittent signals when a concave surface is encountered. The distance compensation and the luminosity compensation are simultaneously completed in one following action.

Description

Technical Field

[0001] This invention relates to the field of laser measurement technology, and in particular to a laser measurement device for the coaxiality of a steering intermediate shaft. Background Technology

[0002] The steering intermediate shaft is a crucial component of the automotive steering system, and its coaxiality directly affects steering smoothness and safety. In online inspection, laser non-contact measurement is widely used due to its high efficiency and accuracy. A typical laser coaxiality testing device uses a laser displacement sensor to emit a laser beam onto the workpiece surface, receives the reflected light, calculates the distance, and after the workpiece rotates one revolution, fits the center of the circle based on data from each cross-section to ultimately assess the coaxiality error.

[0003] In existing laser inspection devices, the distance between the sensor and the workpiece surface changes in real time due to workpiece movement and bending, causing fluctuations in the laser spot size and defocusing, introducing nonlinear errors. Simultaneously, convex surfaces on the workpiece surface scatter the laser, generating stray light and causing jumps, while concave surfaces cause multiple laser reflections, resulting in signal discontinuity. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a laser measurement device for the coaxiality of a steering intermediate shaft.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A laser measuring device for the coaxiality of a steering intermediate shaft includes: an electric guide rail; a sleeve fixed on a slide of the electric guide rail; a metal ball bearing that is rolled on the end of the sleeve for contacting the surface of the workpiece during measurement and sensing its radial undulations; a laser displacement sensor disposed at the upper end of the sleeve; and two V-shaped steel plates that are inverted and attached to each other on the receiving side of the laser displacement sensor, with a light-transmitting hole formed in the middle after the two V-shaped steel plates cross. When the metal ball bearing encounters a convex surface, it drives the laser displacement sensor and the two V-shaped steel plates to move synchronously away from the workpiece along the axial direction of the sleeve, while simultaneously driving the two V-shaped steel plates to move synchronously towards each other, thus reducing the aperture of the light-transmitting hole. When the metal ball bearing encounters a concave surface, it drives the laser displacement sensor and the two V-shaped steel plates to move synchronously towards the workpiece along the axial direction of the sleeve, while simultaneously driving the two V-shaped steel plates to move synchronously away from each other, thus increasing the aperture of the light-transmitting hole.

[0006] Preferably, a first piston plate is slidably connected to the inner surface of the sleeve, a connecting rod is fixedly connected to the middle of the side of the first piston plate, a spherical groove is opened at the end of the connecting rod away from the first piston plate, a metal ball is slidably connected inside the spherical groove, and a first spring is fastened between the side of the first piston plate away from the connecting rod and the inner bottom surface of the sleeve.

[0007] Preferably, a first U-shaped tube is fixedly connected to the middle of the side of the first piston plate, the first spring is sleeved on the outside of the first U-shaped tube, a movable ring is fixedly connected to the end of the first U-shaped tube away from the first piston plate, the movable ring is sleeved and slides on the outer surface of the sleeve, the movable ring is connected to a V-shaped steel sheet, an L-shaped rod is also fixedly connected to the outside of the first U-shaped tube, the laser displacement sensor is fixedly installed on the end of the L-shaped rod, and the middle position of the ends of the first U-shaped tube and the sleeve is slidably connected to each other.

[0008] Preferably, a second U-shaped tube is symmetrically fixedly connected to both sides of the movable ring. A second piston plate is slidably connected to the inner surface of the second U-shaped tube opposite to the movable ring. A telescopic rod is fixedly connected to the middle of the side of the second piston plate. A second spring is sleeved on the outer side of the telescopic rod. The second spring is fastened between the side of the second piston plate and the side of the end of the second U-shaped tube. The end of the telescopic rod opposite to the second piston plate is fixedly connected to the corresponding V-shaped steel sheet.

[0009] Preferably, the space formed by the side of the first piston plate and the inner wall of the sleeve is an oil storage chamber, an oil delivery pipe is provided inside the first U-shaped tube, and multiple evenly distributed and through oil holes are provided on the side wall of the oil delivery pipe. The oil storage chamber, the oil delivery pipe, the movable ring and the second U-shaped tube are all filled with hydraulic oil and are interconnected.

[0010] Preferably, the optical axis of the laser displacement sensor is collinear with the central axis of the light-transmitting hole.

[0011] Preferably, support rods are fixedly connected to both sides of the bottom end of the sleeve, and mounting plates are fixedly connected to the bottom ends of the support rods. The mounting plates are fastened to the upper end of the slide of the electric guide rail by bolts.

[0012] Preferably, the electric guide rail includes a slide rail, a lead screw, a servo motor, and a slide block. The servo motor is fixedly installed at the end of the slide rail, and its output shaft is fixedly connected to the end of the lead screw. The other end of the lead screw is rotatably connected to the end of the slide rail through a bearing. The slide block is slidably connected to the slide rail, and the slide block and the lead screw are threaded together.

[0013] Preferably, the electric guide slide moves along the axis of the intermediate steering shaft to be detected.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The metal ball bearings adhere to the surface of the workpiece and sense its radial undulations. When the workpiece rotates, the metal ball bearings directly drive the laser displacement sensor to move synchronously along the axis of the sleeve. Physically, this forces the distance between the laser displacement sensor and the workpiece surface to always be locked at the optimal working distance, thus eliminating the changes in spot size and defocusing error caused by fluctuations in measurement distance. 2. When encountering a convex surface, the metal ball drives the two V-shaped steel plates to move towards each other, making the light-transmitting hole smaller and physically blocking the stray light generated by the convex surface scattering, allowing only pure signals to enter and preventing jump points. When encountering a concave surface, the metal ball drives the two V-shaped steel plates to move away from each other, making the light-transmitting hole larger, expanding the receiving angle, capturing the unpredictable reflected light caused by multiple reflections from the concave surface, and preventing signal interruption. 3. All actions are directly driven by the undulations of the workpiece surface, without relying on electronic sensor feedback, and without requiring independent motors or pneumatic modules. The whole machine has a compact structure, few parts, direct action response, and is not sensitive to production line vibration, oil stains and electromagnetic interference. It is stable and reliable in long-term operation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the laser measurement device for the coaxiality of the steering intermediate shaft according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the sleeve in the laser measurement device for the coaxiality of the steering intermediate shaft according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of the second U-shaped tube in the laser measurement device for the coaxiality of the steering intermediate shaft according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the phase separation motion state of the V-shaped steel sheet in the laser measurement device for the coaxiality of the steering intermediate shaft according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the V-shaped steel plates moving towards each other in the laser measuring device for the coaxiality of the steering intermediate shaft according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the connecting rod retracting into the sleeve in the laser measuring device for the coaxiality of the steering intermediate shaft according to an embodiment of the present invention; Figure 7 for Figure 1 Enlarged view of the structure at point A in the image; Figure 8 for Figure 2 Enlarged view of the structure at point B in the image.

[0016] In the diagram: 100, electric guide rail; 200, support rod; 201, mounting plate; 202, bolt; 300, sleeve; 301, first piston plate; 302, connecting rod; 303, spherical groove; 304, metal ball; 305, first U-shaped tube; 306, L-shaped rod; 307, laser displacement sensor; 308, first spring; 400, movable ring; 401, second U-shaped tube; 402, second piston plate; 403, telescopic rod; 404, V-shaped steel sheet; 405, second spring; 406, oil pipeline; 407, oil hole; 408, oil storage chamber. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] The terms used in this invention, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0019] like Figures 1-8 As shown, this embodiment of the invention provides a laser measuring device for the coaxiality of a steering intermediate shaft, comprising: an electric guide rail 100; a sleeve 300 fixedly mounted on a slide of the electric guide rail 100; metal balls 304 rotatably disposed at the end of the sleeve 300, used to conform to the surface of the workpiece being measured and sense its radial undulations during measurement; a laser displacement sensor 307 disposed at the upper end of the sleeve 300; and two V-shaped steel plates 404, inverted and attached to the receiving side of the laser displacement sensor 307, with a light-transmitting hole formed in the middle after the two V-shaped steel plates 404 cross; wherein, When the metal ball 304 encounters a convex surface, the metal ball 304 drives the laser displacement sensor 307 and the two V-shaped steel plates 404 to move synchronously away from the workpiece along the axial direction of the sleeve 300, while simultaneously driving the two V-shaped steel plates 404 to move synchronously towards each other, thus reducing the aperture of the light-transmitting hole. When the metal ball 304 encounters a concave surface, the metal ball 304 drives the laser displacement sensor 307 and the two V-shaped steel plates 404 to move synchronously towards the workpiece along the axial direction of the sleeve 300, while simultaneously driving the two V-shaped steel plates 404 to move synchronously away from each other, thus increasing the aperture of the light-transmitting hole.

[0020] In this embodiment, when the measurement begins, the electric guide rail 100 drives the slide to move, moving the metal ball 304 and the laser displacement sensor 307 to the first section to be measured on the steering intermediate shaft. The metal ball 304 is in contact with the surface of the steering intermediate shaft, and the steering intermediate shaft is driven to rotate at a constant speed by an external rotating device. During rotation, when the metal ball 304 encounters the convex surface, the convex surface lifts the metal ball 304, causing the metal ball 304 to drive the laser displacement sensor 307 and the two V-shaped steel plates 404 to move synchronously away from the workpiece along the axial direction of the sleeve 300. This movement physically forces the distance between the laser displacement sensor 307 and the workpiece surface to always be locked at the optimal working distance, eliminating the fluctuation of the spot size and defocusing error caused by distance changes at the source. At the same time, this movement synchronously drives the two V-shaped steel plates 404 to move towards each other, making the aperture of the light transmission hole smaller. Since the convex surface easily disperses the laser and generates stray light, causing jump points, the smaller aperture physically blocks stray light, allowing only the pure signal returning from the apex of the convex surface to enter the receiving side, realizing spatial filtering and ensuring the purity of the measurement signal. When the metal ball 304 encounters the concave surface, the metal ball 304 drives the laser displacement sensor 307 and the two V-shaped steel plates 404 to move synchronously towards the workpiece along the axial direction of the sleeve 300. This also locks the distance between the laser displacement sensor 307 and the workpiece surface at the optimal working distance. At the same time, this movement synchronously drives the two V-shaped steel plates 404 to move apart, making the aperture of the light transmission hole larger. Because the concave surface causes the laser to reflect multiple times inside, resulting in an uncertain direction of the emitted light and a discontinuous signal, the larger aperture effectively expands the receiving angle, captures the unstable reflected light, and ensures the continuity of the signal. After the metal ball 304 rolls over the convex or concave surface, the workpiece surface returns to a normal cylindrical surface, the metal ball 304 returns to its normal position, driving the laser displacement sensor 307 and the two V-shaped steel plates 404 to reset, and the aperture of the light-transmitting hole returns to its initial size. Since the jump points and signal loss caused by distance changes and surface optical interference are eliminated, the collected contour data truly reflects the geometry of the workpiece. After the contour data of all sections are collected, the system calculates the coaxiality error of the measured workpiece based on the fitted center of each section, and completes the high-precision coaxiality evaluation.

[0021] like Figure 2 and Figure 8 As shown, optionally, a first piston plate 301 is slidably connected to the inner surface of the sleeve 300, a connecting rod 302 is fixedly connected to the middle of the side of the first piston plate 301, a spherical groove 303 is opened at the end of the connecting rod 302 away from the first piston plate 301, a metal ball 304 is slidably connected inside the spherical groove 303, and a first spring 308 is fastened between the side of the first piston plate 301 away from the connecting rod 302 and the inner bottom surface of the sleeve 300.

[0022] Specifically, a first piston plate 301 is slidably connected to the inner surface of the sleeve 300. The first piston plate 301 can reciprocate along the axis of the sleeve 300. A connecting rod 302 is fixedly connected to the middle of the side of the first piston plate 301. The connecting rod 302 extends out of the sleeve 300 towards the workpiece. A spherical groove 303 is opened at the end of the connecting rod 302 away from the first piston plate 301. The inner wall of the spherical groove 303 is spherical. A metal ball 304 is slidably connected inside the spherical groove 303. The metal ball 304 can roll in all directions in the spherical groove 303. A first spring 308 is fastened between the side of the first piston plate 301 away from the connecting rod 302 and the inner bottom surface of the sleeve 300. The first spring 308 pushes the first piston plate 301, the connecting rod 302 and the metal ball 304 as a whole towards the workpiece, so that the metal ball 304 always maintains elastic contact with the surface of the workpiece during the measurement process.

[0023] In this optional embodiment, the first spring 308 provides an elastic preload to ensure that the metal ball 304 fits tightly against both the normal cylindrical section and the concave section of the workpiece surface, preventing it from slipping out. When encountering a convex surface, the convex surface overcomes the elastic force of the first spring 308 and lifts the metal ball 304, with the displacement transmitted to the first piston plate 301 via the connecting rod 302. When encountering a concave surface, the first spring 308 pushes the first piston plate 301, causing the metal ball 304 to extend into the concave surface. The sliding of the first piston plate 301 converts the radial displacement of the metal ball 304 into a driving source for the hydraulic system, providing power for subsequent constant distance and light-transmitting aperture adjustment.

[0024] like Figures 1-4 As shown, optionally, a first U-shaped tube 305 is fixedly connected to the middle of the side of the first piston plate 301, a first spring 308 is sleeved on the outside of the first U-shaped tube 305, a movable ring 400 is fixedly connected to the end of the first U-shaped tube 305 away from the first piston plate 301, the movable ring 400 is sleeved and slides on the outer surface of the sleeve 300, the movable ring 400 is connected to a V-shaped steel sheet 404, an L-shaped rod 306 is also fixedly connected to the outside of the first U-shaped tube 305, a laser displacement sensor 307 is fixedly installed on the end of the L-shaped rod 306, and the first U-shaped tube 305 and the middle of the end of the sleeve 300 are slidably connected to each other.

[0025] Specifically, the movable ring 400 is fitted and slides on the outer surface of the sleeve 300, and can slide along the axis of the sleeve 300 with the first U-shaped tube 305.

[0026] In this optional embodiment, the displacement of the first piston plate 301 is synchronously transmitted to the movable ring 400 and the L-shaped rod 306 through the first U-shaped tube 305. The movable ring 400 drives the V-shaped steel sheet 404 to move, and the L-shaped rod 306 drives the laser displacement sensor 307 to move. The two move in the same direction and with the same displacement, ensuring that the relative position between the receiving side of the laser displacement sensor 307 and the V-shaped steel sheet 404 remains unchanged, and the light-transmitting hole is always located in the correct position of the receiving optical path.

[0027] like Figures 3-4 As shown, optionally, a second U-shaped tube 401 is symmetrically fixedly connected to both sides of the movable ring 400. A second piston plate 402 is slidably connected to the inner surface of the second U-shaped tube 401 at the end opposite to the movable ring 400. A telescopic rod 403 is fixedly connected to the middle of the side of the second piston plate 402. A second spring 405 is sleeved on the outer side of the telescopic rod 403. The second spring 405 is fastened between the side of the second piston plate 402 and the side of the end of the second U-shaped tube 401. The end of the telescopic rod 403 opposite to the second piston plate 402 is fixedly connected to the corresponding V-shaped steel sheet 404.

[0028] Specifically, the openings of the two second U-shaped tubes 401 are arranged opposite to each other. A second piston plate 402 is slidably connected to the inner surface of the end of each second U-shaped tube 401 away from the movable ring 400. The second piston plate 402 can slide inside the second U-shaped tube 401. A telescopic rod 403 is fixedly connected to the middle of the side of each second piston plate 402. The telescopic rod 403 extends toward the light-transmitting hole.

[0029] In this optional embodiment, the second spring 405 provides a restoring force to the second piston plate 402, keeping the V-shaped steel sheet 404 in its initial position when there is no external force. When the movable ring 400 moves, the second U-shaped tube 401 moves accordingly, and the internal hydraulic pressure changes drive the second piston plate 402 to slide, thereby moving the telescopic rod 403 and the V-shaped steel sheet 404. The two V-shaped steel sheets 404 are arranged symmetrically; when they move towards each other, the light-transmitting hole closes, and when they move away from each other, the light-transmitting hole opens.

[0030] like Figures 1-7 As shown, optionally, the space formed by the side of the first piston plate 301 and the inner wall of the sleeve 300 is an oil storage chamber 408. An oil delivery pipe 406 is provided inside the first U-shaped tube 305. A plurality of evenly distributed and through oil holes 407 are provided on the side wall of the oil delivery pipe 406. The oil storage chamber 408, the oil delivery pipe 406, the movable ring 400, and the second U-shaped tube 401 are all filled with hydraulic oil and are interconnected.

[0031] Specifically, the oil hole 407 connects the oil supply pipe 406 and the oil storage chamber 408. The interior of the oil storage chamber 408, the interior of the oil supply pipe 406, the interior of the movable ring 400, and the interior of the second U-shaped pipe 401 are all filled with hydraulic oil and are interconnected to form a closed hydraulic circuit.

[0032] In this optional embodiment, when the metal ball 304 encounters a convex surface and is lifted, the first piston plate 301 compresses the oil reservoir 408. Hydraulic oil enters the oil supply pipe 406 through the oil hole 407, and then enters the second U-shaped tube 401 through the internal oil passage of the movable ring 400. This pushes the two second piston plates 402 to move towards each other, driving the V-shaped steel plates 404 to move towards each other and close the light-transmitting hole. When the metal ball 304 encounters a concave surface, the first piston plate 301 moves towards the workpiece under the action of the first spring 308, increasing the volume of the oil reservoir 408. Hydraulic oil in the second U-shaped tube 401 flows back, and the second piston plates 402 move apart under the action of the second spring 405, driving the V-shaped steel plates 404 to move apart and open the light-transmitting hole.

[0033] like Figure 1 As shown, optionally, the optical axis of the laser displacement sensor 307 is collinear with the central axis of the light-transmitting hole.

[0034] Specifically, two V-shaped steel plates 404 are symmetrically arranged in front of the receiving side of the laser displacement sensor 307. The optical axis of the laser displacement sensor 307 is collinear with the central axis of the light-transmitting hole formed by the intersection of the two V-shaped steel plates 404. The reflected laser passes through the light-transmitting hole and enters the receiving side of the laser displacement sensor 307.

[0035] In this optional embodiment, the optical axis is collinear with the central axis of the light-transmitting aperture, ensuring that the reflected laser passes through the center of the light-transmitting aperture. The light spot is symmetrically blocked by the light-transmitting aperture, preventing the introduction of eccentricity errors. When the V-shaped steel sheet 404 adjusts the size of the light-transmitting aperture, the light spot is symmetrically restricted or expanded, and the energy distribution of the light spot received by the photosensitive element remains symmetrical, ensuring that the accuracy of the measurement data is not affected by the photometric compensation action.

[0036] like Figure 1 As shown, optionally, support rods 200 are fixedly connected to both sides of the bottom end of the sleeve 300, and mounting plates 201 are fixedly connected to the bottom end of the support rods 200. The mounting plates 201 are fastened to the upper end of the slide of the electric guide rail 100 by bolts 202.

[0037] In this optional embodiment, the sleeve 300 is fixed to the slide of the electric guide rail 100 by the support rod 200 and the mounting plate 201. The mounting plate 201 is connected to the slide bolt 202, which facilitates disassembly and maintenance.

[0038] like Figure 1As shown, optionally, the electric guide rail 100 includes a slide rail, a lead screw, a servo motor, and a slide block. The servo motor is fixedly installed at the end of the slide rail, and its output shaft is fixedly connected to the end of the lead screw. The other end of the lead screw is rotatably connected to the end of the slide rail through a bearing. The slide block is slidably connected to the slide rail, and the slide block and the lead screw are threaded together.

[0039] In this optional embodiment, a servo motor drives a lead screw to rotate, which converts the rotational motion into linear motion of the slide, achieving precise positioning of the measuring head along the workpiece axis. The electric guide rail 100 can move the metal ball bearing 304 and the laser displacement sensor 307 to any section of the workpiece to be measured, enabling automatic measurement of multiple sections without manual adjustment, thus improving measurement efficiency. Since the electric guide rail 100 is prior art, it will not be described in detail here.

[0040] like Figure 1 As shown, optionally, the electric guide rail 100 slide moves along the axis of the intermediate steering shaft to be detected.

[0041] In this optional embodiment, the slide moves along the workpiece axis, allowing the metal ball 304 and the laser displacement sensor 307 to cover all test sections along the entire length of the workpiece. The system can preset the cross-sectional spacing and number, automatically complete the contour data acquisition of all cross-sections, and then calculate the coaxiality error based on the fitted center of each cross-section, achieving fully automatic high-precision evaluation.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A laser measuring device for the coaxiality of a steering intermediate shaft, characterized in that, include: Electrically conductive rail (100); The sleeve (300) is fixed on the slide of the electric guide rail (100); Metal balls (304) are rolled on the end of the sleeve (300) to fit against the surface of the workpiece being measured and to sense its radial undulations during measurement; A laser displacement sensor (307) is disposed at the upper end of the sleeve (300); Two V-shaped steel sheets (404) are inverted and attached to each other on the receiving side of the laser displacement sensor (307), and a light-transmitting hole is formed in the middle after the two V-shaped steel sheets (404) cross. When the metal ball (304) encounters the convex surface, the metal ball (304) drives the laser displacement sensor (307) and the two V-shaped steel plates (404) to move away from the workpiece along the axial direction of the sleeve (300) at the same time, and drives the two V-shaped steel plates (404) to move towards each other at the same time, so that the aperture of the light-transmitting hole becomes smaller. When the metal ball (304) encounters the concave surface, the metal ball (304) drives the laser displacement sensor (307) and the two V-shaped steel plates (404) to move synchronously toward the workpiece along the axial direction of the sleeve (300), and at the same time drives the two V-shaped steel plates (404) to move synchronously away from each other, so that the aperture of the light-transmitting hole becomes larger. A first piston plate (301) is slidably connected to the inner surface of the sleeve (300). A connecting rod (302) is fixedly connected to the middle of the side of the first piston plate (301). A spherical groove (303) is opened at the end of the connecting rod (302) away from the first piston plate (301). A metal ball (304) is rolled inside the spherical groove (303). A first spring (308) is fastened between the side of the first piston plate (301) away from the connecting rod (302) and the inner bottom surface of the sleeve (300). A first U-shaped tube (305) is fixedly connected to the middle of the side of the first piston plate (301). The first spring (308) is sleeved on the outside of the first U-shaped tube (305). A movable ring (400) is fixedly connected to the end of the first U-shaped tube (305) away from the first piston plate (301). The movable ring (400) is sleeved and slides on the outer surface of the sleeve (300). The movable ring (400) is connected to a V-shaped steel sheet (404). An L-shaped rod (306) is also fixedly connected to the outside of the first U-shaped tube (305). The laser displacement sensor (307) is fixedly installed on the end of the L-shaped rod (306). The first U-shaped tube (305) and the middle of the end of the sleeve (300) are slidably connected to each other. The movable ring (400) is symmetrically fixedly connected to two sides of a second U-shaped tube (401). A second piston plate (402) is slidably connected to the inner surface of the second U-shaped tube (401) away from the movable ring (400). A telescopic rod (403) is fixedly connected to the middle of the side of the second piston plate (402). A second spring (405) is sleeved on the outer side of the telescopic rod (403). The second spring (405) is fastened between the side of the second piston plate (402) and the side of the end of the second U-shaped tube (401). The end of the telescopic rod (403) away from the second piston plate (402) is fixedly connected to the corresponding V-shaped steel sheet (404). The space formed by the side of the first piston plate (301) and the inner wall of the sleeve (300) is an oil storage chamber (408). An oil delivery pipe (406) is provided inside the first U-shaped tube (305). A plurality of evenly distributed and through oil holes (407) are provided on the side wall of the oil delivery pipe (406). The oil storage chamber (408), the oil delivery pipe (406), the movable ring (400), and the second U-shaped tube (401) are all filled with hydraulic oil and are interconnected.

2. The laser measuring device for the coaxiality of the steering intermediate shaft according to claim 1, characterized in that, The optical axis of the laser displacement sensor (307) is collinear with the central axis of the light-transmitting hole.

3. The laser measuring device for the coaxiality of the steering intermediate shaft according to claim 1, characterized in that, Support rods (200) are fixedly connected to both sides of the bottom end of the sleeve (300). A mounting plate (201) is fixedly connected to the bottom end of the support rod (200). The mounting plate (201) is fastened to the upper end of the slide of the electric guide rail (100) by bolts (202).

4. The laser measuring device for the coaxiality of the steering intermediate shaft according to claim 1, characterized in that, The electric guide rail (100) includes a slide rail, a lead screw, a servo motor, and a slide block. The servo motor is fixedly installed at the end of the slide rail, and its output shaft is fixedly connected to the end of the lead screw. The other end of the lead screw is rotatably connected to the end of the slide rail through a bearing. The slide block is slidably connected to the slide rail, and the slide block and the lead screw are threaded together.

5. The laser measuring device for the coaxiality of the steering intermediate shaft according to claim 1, characterized in that, The electric guide rail (100) slide moves along the axis of the intermediate steering shaft to be tested.

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