Laser inner hole coaxiality detection device and detection method thereof

Abstract

The invention relates to the technical field of inner hole coaxiality detection, in particular to a laser inner hole coaxiality detection device and a detection method thereof.The detection device comprises a first connecting mechanism, a second connecting mechanism and a laser detection mechanism, and each of the first connecting mechanism and the second connecting mechanism comprises a shell, an elastic supporting assembly, a push rod assembly and a mounting base; the laser detection mechanism is used for emitting laser beams and receiving and detecting the positions of laser spots; the push rod assembly can move in the axial direction of the shell. When the push rod assembly moves towards the front end of the shell, the push rod assembly drives the elastic supporting assembly to expand outwards in the radial direction, and fixing with the inner hole wall is achieved. When the push rod assembly moves towards the rear end of the shell, the elastic supporting assembly shrinks inwards in the radial direction under the action of the elastic force of the elastic supporting assembly. The clamping device has the advantages that inner hole type workpieces with different hole diameters can be rapidly, stably and accurately clamped through the elastic supporting assembly and the push rod assembly, and therefore the detection efficiency and the clamping universality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inner hole coaxiality detection, and in particular to a laser inner hole coaxiality detection device and a detection method thereof. Background Art

[0002] Ensuring component coaxiality accuracy is crucial in numerous industrial fields, including machining and precision manufacturing. Coaxiality errors in many mechanical products, such as engine crankshafts and bearings, and automotive drive shafts and wheel hubs, can directly impact product performance, service life, and operational stability. Traditional coaxiality testing methods typically rely on high-precision measuring tools, such as micrometers and coordinate measuring machines. While these methods offer high accuracy, they also suffer from complex operations, low detection efficiency, high operator skill requirements, and difficulty implementing online, real-time testing.

[0003] With the development of laser technology, lasers are increasingly being used in measurement. Lasers possess properties such as high directivity, high coherence, and high brightness, enabling laser-based measurement methods to achieve high-precision, non-contact measurements. For coaxiality testing, the linear propagation characteristics of lasers can be exploited to indirectly infer the coaxiality error of a workpiece by measuring the deflection of the laser beam. However, existing laser coaxiality detection devices are often complex in structure, difficult to clamp, and difficult to adapt to workpieces of varying sizes and shapes. Summary of the Invention

[0004] In view of this, the present invention aims to provide a laser internal hole coaxiality detection device and a detection method thereof, which can quickly, stably and accurately clamp internal hole workpieces with different apertures through an elastic support component and a push rod component, thereby improving the detection efficiency and the versatility of clamping.

[0005] To achieve the above-mentioned purpose, the technical solution created by the present invention is implemented as follows: a laser inner hole coaxiality detection device, comprising: a first connecting mechanism and a second connecting mechanism, the first connecting mechanism and the second connecting mechanism are respectively clamped in the inner hole to be detected for coaxiality; the first connecting mechanism and the second connecting mechanism both include a shell, an elastic support assembly, a push rod assembly and a mounting seat; the elastic support assembly and the push rod assembly are arranged in the shell; the mounting seat is connected to the front end of the shell; the push rod assembly can move axially along the shell; when the push rod assembly moves toward the front end of the shell, the push rod assembly drives the elastic support assembly to expand radially outward to achieve fixation with the inner hole; when the push rod assembly moves toward the rear end of the shell, the elastic support assembly contracts radially inward under the action of its own elastic force; a laser detection mechanism, the laser detection mechanism includes a laser emitter and a laser receiver, the laser emitter is arranged in the mounting seat of the first connecting mechanism for emitting a laser beam; the laser receiver is arranged in the mounting seat of the second connecting mechanism for receiving and detecting the position of the laser spot.

[0006] Furthermore, the elastic support assembly includes three support rods and three elastic elements; the three support rods are evenly arranged along the inner circumferential direction of the shell; each support rod is provided with a first tapered thread at one end close to the push rod assembly, and the three first tapered threads together constitute a tapered thread hole; the three elastic elements are arranged in a one-to-one correspondence with the three support rods, one end of each elastic element is connected to the corresponding support rod, and the other end of each elastic element is connected to the shell.

[0007] Furthermore, the push rod assembly includes a push rod and a rotating head; the push rod includes a rod body and a conical head; the two ends of the rod body are respectively connected to the conical head and the rotating head; the outer surface of the conical head is provided with a second conical thread adapted to the conical threaded hole; the rotating head includes a first rotating head and a second rotating head, the first rotating head is used to realize rapid advancement of the push rod, and the second rotating head is used to realize fine-tuning compensation of the push rod.

[0008] Furthermore, the first rotating head includes a connecting part and a first threaded part; the connecting part is connected to the second rotating head, and the first threaded part is connected to the shell; the end of the rod body away from the cone head is connected to the connecting part; the first threaded part is provided with a first internal thread for connecting to the shell; the second rotating head includes a connecting shell, a driving handle, a first gear and a second gear; the connecting shell is sleeved on the outside of the connecting part; the first gear and the second gear are located in the connecting shell; wherein, the second gear is connected to the connecting part and meshes with the first gear; the diameter of the first gear is smaller than the diameter of the second gear; a driving shaft is provided on the driving handle, and the driving shaft passes through the connecting shell and is connected to the first gear.

[0009] Furthermore, the shell includes a first cavity, a second cavity and a connecting seat; one end of the second cavity is sleeved on the outside of the first cavity, and the other end of the second cavity is connected to the connecting seat; the end of the first cavity away from the second cavity is provided with a first external thread adapted to the first internal thread; the first rotating head is threadedly connected to the first cavity through the first internal thread and the first external thread; the rod body is accommodated in the first cavity, and the cone head extends into the second cavity.

[0010] Furthermore, the connecting seat has an accommodating cavity, and its outer peripheral surface has three protrusions evenly distributed along the circumferential direction, and the three protrusions are formed by the connecting seat extending radially outward; each protrusion is provided with a through hole, and each through hole corresponds to a support rod; one end of the three support rods is arranged in the accommodating cavity, and the other ends of the three support rods respectively extend into the corresponding through holes.

[0011] Furthermore, three connecting rods are evenly distributed along the circumference on the end face of the connecting seat close to the second cavity, and the axis of each connecting rod is parallel to the axis of the connecting seat; a limiting groove is provided on each support rod, and one end of each elastic element is connected to the corresponding limiting groove, and the other end of each elastic element is connected to the corresponding connecting rod.

[0012] Furthermore, the elastic element is a vortex spring, a wire torsion spring, or a straight-tube torsion spring.

[0013] A laser-based inner hole coaxiality detection method is implemented using the above-mentioned laser inner hole coaxiality detection device, comprising the following steps: S1: The first connecting mechanism equipped with the laser transmitter and the second connecting mechanism equipped with the laser receiver are respectively clamped in the inner hole to be detected; the elastic support assembly is driven to expand radially by the push rod assembly to achieve three-point self-centering fixation.

[0014] S2: Start the laser transmitter and emit a collimated laser beam. The laser receiver receives the spot image and calculates the center coordinates of the spot.

[0015] S3: moving the first connecting mechanism and the second connecting mechanism along the axis direction of the inner hole to collect the light spot position data of at least three cross sections of the inner hole.

[0016] S4: Use the least squares method to fit the spot position data collected in step S3 to obtain the actual axis position.

[0017] S5: Difference between the actual axis position and the theoretical axis position of the inner hole. The difference is the coaxiality of the inner hole.

[0018] Compared with the prior art, the present invention can achieve the following beneficial effects: 1) The present invention features three protrusions evenly distributed along the outer circumference of the connecting seat, each of which is provided with a through-hole. These through-holes provide radial support and guidance for the three support rods of the elastic support assembly, enabling radial outward expansion and inward contraction. Furthermore, the external threads at the rear end of the first cavity directly mate with the internal threads of the push rod assembly, achieving axial movement of the push rod assembly through threaded transmission, eliminating the need for additional transmission components. This structural design is simple and easy to operate.

[0019] 2) The three support rods can be designed into various lengths to meet the coaxiality detection requirements of inner holes of different diameters. The three-point support design can achieve automatic centering to ensure that the center of the laser inner hole coaxiality detection device coincides with the center of the inner hole being detected. It avoids measurement errors caused by inaccurate manual clamping and improves measurement accuracy. At the same time, with the help of elastic elements, the three support rods can be automatically reset. This design makes the elastic support assembly simple in structure and easy to replace. If the support rod or elastic element is worn during long-term use, it can be easily replaced, reducing maintenance costs. Moreover, the simple structure also means that it is easier to process and assemble during the manufacturing process, thereby improving production efficiency.

[0020] 3) The two-stage adjustment function of the rotating head is used to achieve rapid advancement and fine-tuning compensation of the push rod, thereby expanding or contracting the support rod. This operation method is simple and intuitive. Operators do not need complex tools or tedious steps. They can achieve clamping and positioning of different inner holes by manually rotating the rotating head, which greatly improves work efficiency. At the same time, the radial expansion degree of the support rod is adjusted by rotating the first rotating head. This adjustability enables the structure to be widely used in the detection of inner holes of different specifications. In addition, the stable support of the three support rods on the inner hole wall provides a stable measurement platform for the detection device. When the support rods are fully supported on the inner hole wall, the detection device can remain relatively still, reducing measurement errors caused by factors such as device shaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 2 is a schematic structural diagram of a laser inner hole coaxiality detection device according to an embodiment of the present invention; Figure 2 is a structural schematic diagram of a first connecting mechanism provided according to an embodiment of the present invention; Figure 3 is a structural schematic diagram of a housing provided according to an embodiment of the present invention; Figure 4 According to an embodiment of the present invention, Figure 3 A cross-sectional view taken along the axis of the housing; Figure 5 is a structural schematic diagram of an elastic support assembly and a connecting seat provided according to an embodiment of the present invention; Figure 6 is a structural schematic diagram of an elastic support assembly provided according to an embodiment of the present invention; Figure 7 is a schematic structural diagram of a support rod provided according to an embodiment of the present invention; Figure 8 2 is a schematic structural diagram of a push rod assembly provided according to an embodiment of the present invention.

[0022] The accompanying drawings include: 1. first connecting mechanism; 11. shell; 111. first cavity; 112. second cavity; 113. connecting seat; 114. protrusion; 115. connecting rod; 12. elastic support assembly; 121. support rod; 122. elastic element; 123. first tapered thread; 124. limiting groove; 13. push rod assembly; 131. push rod; 132. first rotating head; 133. second rotating head; 1331. connecting shell; 1332. driving handle; 1333. first gear; 1334. second gear; 134. rod body; 135. tapered head; 136. connecting part; 137. first threaded part; 14. mounting seat; 2. second connecting mechanism; 3. laser transmitter; 4. laser receiver. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0027] The present invention will be described in detail below with reference to the embodiments.

[0028] like Figures 1 to 8 As shown, an embodiment of the present invention provides a laser inner hole coaxiality detection device, comprising: a first connecting mechanism 1, a second connecting mechanism 2 and a laser detection mechanism. The first connecting mechanism 1 and the second connecting mechanism 2 are respectively clamped in the inner hole whose coaxiality is to be detected. The laser detection mechanism includes a laser emitter 3 and a laser receiver 4. The laser emitter 3 is arranged on the first connecting mechanism 1 and is used to emit a laser beam. The laser receiver 4 is arranged on the second connecting mechanism 2 and is used to receive and detect the position of the laser spot. The laser inner hole coaxiality detection device of the present invention is not only suitable for the coaxiality detection of two independent inner holes, but also for the coaxiality detection of long inner holes.

[0029] The first connecting mechanism 1 and the second connecting mechanism 2 have the same structure, and both include a shell 11, an elastic support assembly 12, a push rod assembly 13 and a mounting seat 14. The elastic support assembly 12 and the push rod assembly 13 are at least partially arranged in the shell 11, and the mounting seat 14 is connected to the front end of the shell 11. The push rod assembly 13 can move axially along the shell 11. When the push rod assembly 13 moves toward the front end of the shell 11, the push rod assembly 13 drives the elastic support assembly 12 to expand radially outward to achieve fixation with the inner hole. When the push rod assembly 13 moves toward the rear end of the shell 11, the elastic support assembly 12 contracts radially inward under the action of its own elastic force.

[0030] The shell 11 includes a first cavity 111, a second cavity 112 and a connecting seat 113. One end of the second cavity 112 is sleeved on the outside of the first cavity 111, and the other end of the second cavity 112 is connected to the connecting seat 113. The connecting seat 113 has a accommodating cavity, and its outer circumferential surface is evenly distributed with three protrusions 114 along the circumferential direction. The three protrusions 114 are formed by the connecting seat 113 extending radially outward. Each protrusion 114 is provided with a through hole. On the end surface of the connecting seat 113 close to the second cavity 112, three connecting rods 115 are evenly distributed along the circumferential direction, and the axis of each connecting rod 115 is parallel to the axis of the connecting seat 113. The rear end of the first cavity 111 (the end away from the second cavity 112) is provided with a first external thread for screwing with the first internal thread of the push rod assembly 13, so that the push rod assembly 13 can move along the axial direction of the shell 11.

[0031] The through-holes provided in each protrusion 114 provide radial support and guidance for the three support rods 121 of the elastic support assembly 12, enabling radial outward expansion and inward contraction. Furthermore, the first external thread at the rear end of the first cavity 111 directly engages with the first internal thread of the push rod assembly 13, achieving axial movement of the push rod assembly 13 through threaded transmission without the need for additional transmission components. This structural design is simple and easy to operate.

[0032] The elastic support assembly 12 includes three support rods 121 and three elastic elements 122. The three support rods 121 are evenly arranged along the circumferential direction of the accommodating cavity, one end of the three support rods 121 is arranged in the accommodating cavity, and the other ends of the three support rods 121 respectively extend into the through holes of the corresponding protrusions 114, and each support rod 121 can move back and forth along the axial direction of the through hole. When the elastic support assembly 12 is in the initial state, one end of the three support rods 121 intersects in the accommodating cavity. At this time, the other end of the support rod 121 can either extend out of the through hole or remain in the through hole, depending on the diameter of the inner hole to be detected. If the diameter of the inner hole is smaller, the corresponding support rod 121 will be designed to be shorter, and at this time the other end of the support rod 121 will be located in the through hole.

[0033] The initial state refers to the non-working state of the laser inner hole coaxiality detection device, that is, the three support rods 121 are in a retracted state.

[0034] Each support rod 121 is provided with a first tapered thread 123 near the push rod assembly 13. The three first tapered threads 123 together form a tapered threaded hole. Each support rod 121 is provided with a retaining groove 124 for connecting to an elastic element 122. The three elastic elements 122 are arranged in a one-to-one correspondence with the three support rods 121. One end of each elastic element 122 is connected to the retaining groove 124 of the corresponding support rod 121, and the other end of each elastic element 122 is connected to the connecting rod 115. The elastic element 122 is a vortex spring, a steel wire torsion spring, or a straight cylindrical torsion spring.

[0035] When the push rod assembly 13 moves toward the front end of the housing 11, it drives the three support rods 121 to expand radially outward, securing them to the inner hole. At this time, the elastic element 122 stores elastic potential energy. When the push rod assembly 13 moves toward the rear end of the housing 11, the elastic element 122 releases the elastic potential energy, causing the three support rods 121 to contract radially inward, returning the support rods 121 to their initial state.

[0036] The three support rods 121 can be designed into a variety of lengths to meet the coaxiality detection requirements of inner holes of different diameters. The three-point support design can achieve automatic centering to ensure that the center of the laser inner hole coaxiality detection device coincides with the center of the inner hole being detected. Measurement errors caused by inaccurate manual clamping are avoided, and measurement accuracy is improved. At the same time, with the help of the elastic element 122, the three support rods 121 can be automatically reset. This design makes the elastic support assembly 12 simple in structure and easy to replace. If the support rod 121 or the elastic element 122 is worn during long-term use, it can be easily replaced, reducing maintenance costs. Moreover, the simple structure also means that it is easier to process and assemble during the manufacturing process, thereby improving production efficiency.

[0037] In this embodiment, the support rod 121 is suitable for detecting inner holes within the range of Φ50 mm to Φ300 mm.

[0038] The push rod assembly 13 includes a push rod 131 and a rotating head. The push rod 131 includes a rod body 134 and a cone head 135. The rotating head is constructed to have a two-stage adjustment function, which is used to achieve rapid advancement and fine-tuning compensation of the push rod 131 respectively. The rotating head includes a first rotating head 132 and a second rotating head 133. The first rotating head 132 includes a connecting portion 136 and a first threaded portion 137. The connecting portion 136 is connected to the second rotating head 133. Among them, the first threaded portion 137 is provided with a first internal thread that is compatible with the first external thread of the first cavity 111. The connecting portion 136 is provided with a connecting hole that is compatible with the rod body 134. The end of the rod body 134 away from the cone head 135 is fixed in the connecting hole by a pin.

[0039] The second rotating head 133 includes a connecting shell 1331, a driving handle 1332, a first gear 1333, and a second gear 1334. The connecting shell 1331 is sleeved on the outside of the connecting portion 136 and is connected to the housing 11 via a fixing rod. The first gear 1333 and the second gear 1334 are located within the connecting shell 1331. The second gear 1334 is connected to the connecting portion 136 and meshes with the first gear 1333. The diameter of the first gear 1333 is smaller than the diameter of the second gear 1334. A driving shaft is provided on the driving handle 1332, and the driving shaft passes through the connecting shell 1331 and is connected to the first gear 1333.

[0040] When the driving handle 1332 is rotated, the first gear 1333 is driven to rotate via the driving shaft, thereby causing the second gear 1334 to drive the first rotating head 132 to drive the rotating push rod 131 to move.

[0041] In this embodiment, the number of teeth of the first gear 1333 is 17, and the number of teeth of the second gear 1334 is 34. When the rotary drive handle 1332 rotates one circle, the first rotary head 132 rotates half a circle, thereby achieving fine adjustment compensation of the push rod 131.

[0042] The ends of the rod body 134 are connected to the taper head 135 and the connecting hole of the connecting portion 136, respectively. The outer surface of the taper head 135 is provided with a second tapered thread that mates with the taper threaded hole. The rod body 134 is housed within the first cavity 111, and the taper head 135 extends into the second cavity 112. The effective stroke length of the second tapered thread of the taper head 135 directly determines the radial adjustment range of the support rod 121. The effective stroke length of the first internal thread is greater than or equal to the effective stroke length of the second tapered thread.

[0043] In this embodiment, the pitch of the first tapered thread and the second tapered thread is 0.6 mm, and the taper angle of the tapered thread is 45°.

[0044] When the first connecting mechanism 1 or the second connecting mechanism 2 is clamped in the inner hole to be inspected, first, the first rotating head 132 is rotated to drive the push rod 131 to move toward the front end of the housing 11, causing the three support rods 121 to expand radially outward and abut against the inner hole, thereby achieving rapid advancement of the support rods 121. If the three support rods 121 cannot be fully supported on the inner hole wall at this time, the second rotating head 133 is rotated again, and the push rod 131 is driven by the first rotating head 132 to cause the three support rods 121 to produce axial micro-displacement, thereby fully supporting the three support rods 121 on the inner hole wall, achieving precise compensation of the support rods 121.

[0045] Rotating the first and second rotating heads 132, 133 drives the push rod 131 to move, thereby expanding the support rod 121. This simple and intuitive operation eliminates the need for complex tools or tedious steps. Operators can simply manually rotate the rotating heads to achieve clamping and positioning of different inner holes, significantly improving work efficiency. It also provides a two-stage adjustment function.

[0046] When batch testing of inner hole parts, the operator can quickly clamp the detection device into the inner hole of each part to be tested, reducing the clamping time and making the detection process smoother. At the same time, the radial expansion degree of the support rod 121 is adjusted by rotating the first rotating head 132. This adjustability enables the structure to be widely used in inner hole detection of different specifications. In addition, the stable support of the three support rods 121 on the inner hole provides a stable measurement platform for the detection device. When the support rods 121 are fully supported on the inner hole, the detection device can remain relatively still, reducing measurement errors caused by factors such as device shaking.

[0047] A laser-based inner hole coaxiality detection method is implemented using the above-mentioned laser inner hole coaxiality detection device, comprising the following steps: S1: The first connecting mechanism 1 equipped with the laser transmitter 3 and the second connecting mechanism 2 equipped with the laser receiver 4 are respectively clamped in the inner hole to be detected; the elastic support assembly 12 is driven to expand radially by the push rod assembly 13 to achieve three-point self-centering fixation.

[0048] Specifically, the first rotating head 132 is rotated to drive the push rod 131 toward the front end of the housing 11, causing the tapered head 135 to threadably engage the tapered threaded hole formed by the three support rods 121, thereby causing the three support rods 121 to expand radially outward and abut against the inner hole. If the three support rods 121 are not fully supported on the inner hole at this time, the second rotating head 133 is rotated again, driving the push rod 131 through the first rotating head 132, causing the three support rods 121 to undergo a slight axial displacement, thereby fully supporting the three support rods 121 on the inner hole.

[0049] S2: Start the laser transmitter 3 to emit a collimated laser beam. The laser receiver 4 receives the light spot image and calculates the center coordinates of the light spot.

[0050] S3: Move the first connecting mechanism 1 and the second connecting mechanism 2 along the axis of the inner hole to collect light spot position data of at least three cross sections of the inner hole.

[0051] The purpose of collecting the spot position data of three cross sections in this step is to obtain a more accurate axis position when performing data fitting in step S4. In order to further improve the accuracy, the spot position data of more cross sections can also be collected.

[0052] S4: Use the least squares method to fit the spot position data collected in step S3 to obtain the actual axis position.

[0053] It should be noted that the least squares method is an existing algorithm and will not be described in detail here.

[0054] S5: Difference the actual axis position from the theoretical axis position of the inner hole, and multiply the difference by 2 to obtain the coaxiality of the inner hole.

[0055] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A laser inner hole coaxiality detection device, characterized in that: include: a first connecting mechanism and a second connecting mechanism, wherein the first connecting mechanism and the second connecting mechanism are respectively clamped in the inner hole to be tested for coaxiality; The first connecting mechanism and the second connecting mechanism each include a housing, an elastic support assembly, a push rod assembly, and a mounting seat; the elastic support assembly and the push rod assembly are at least partially disposed within the housing; the mounting seat is connected to the front end of the housing; the push rod assembly is movable along the axial direction of the housing; When the push rod assembly moves toward the front end of the housing, the push rod assembly drives the elastic support assembly to expand radially outward to achieve fixation with the inner hole; when the push rod assembly moves toward the rear end of the housing, the elastic support assembly contracts radially inward under the action of its own elastic force; The laser detection mechanism includes a laser emitter and a laser receiver. The laser emitter is arranged in the mounting seat of the first connecting mechanism and is used to emit laser; the laser receiver is arranged in the mounting seat of the second connecting mechanism and is used to receive and detect the position of the laser spot.

2. The laser inner hole coaxiality detection device according to claim 1, characterized in that: The elastic support assembly includes three support rods and three elastic elements; the three support rods are evenly arranged along the inner circumference of the shell; each support rod is provided with a first tapered thread at one end close to the push rod assembly, and the three first tapered threads together constitute a tapered thread hole; The three elastic elements are arranged in a one-to-one correspondence with the three support rods, one end of each elastic element is connected to the corresponding support rod, and the other end of each elastic element is connected to the shell.

3. The laser inner hole coaxiality detection device according to claim 2, characterized in that: The push rod assembly includes a push rod and a rotating head; the push rod includes a rod body and a cone head; the two ends of the rod body are respectively connected to the cone head and the rotating head; The outer surface of the cone head is provided with a second cone thread adapted to the cone thread hole; The rotating head includes a first rotating head and a second rotating head, wherein the first rotating head is used to realize rapid advancement of the push rod, and the second rotating head is used to realize fine adjustment compensation of the push rod.

4. The laser inner hole coaxiality detection device according to claim 3, characterized in that: The first rotating head includes a connecting portion and a first threaded portion; the connecting portion is connected to the second rotating head, and the first threaded portion is connected to the housing; an end of the rod body away from the cone head is connected to the connecting portion; The first threaded portion is provided with a first internal thread for connecting with the housing; The second rotating head includes a connecting shell, a driving handle, a first gear and a second gear; the connecting shell is sleeved on the outside of the connecting part; the first gear and the second gear are located in the connecting shell; wherein, The second gear is connected to the connecting portion and meshes with the first gear; the diameter of the first gear is smaller than the diameter of the second gear; The driving handle is provided with a driving shaft, and the driving shaft passes through the connecting shell and is connected to the first gear.

5. The laser inner hole coaxiality detection device according to claim 4, characterized in that: The housing includes a first cavity, a second cavity and a connecting seat; One end of the second cavity is sleeved on the outside of the first cavity, and the other end of the second cavity is connected to the connecting seat; The first cavity is provided with a first external thread adapted to the first internal thread at one end away from the second cavity; the first rotating head is connected to the first cavity via the first internal thread and the first external thread; The rod body is accommodated in the first cavity, and the cone head extends into the second cavity.

6. The laser inner hole coaxiality detection device according to claim 5, characterized in that: The connecting seat has an accommodating cavity, and its outer circumferential surface is evenly distributed with three protrusions along the circumferential direction, and the three protrusions are formed by the connecting seat extending radially outward; each of the protrusions is provided with a through hole, and each of the through holes corresponds to one of the support rods; one end of the three support rods is arranged in the accommodating cavity, and the other ends of the three support rods respectively extend into the corresponding through holes.

7. The laser inner hole coaxiality detection device according to claim 6, characterized in that: On the end surface of the connecting seat close to the second cavity, three connecting rods are evenly distributed along the circumference, and the axis of each connecting rod is parallel to the axis of the connecting seat; A limiting groove is provided on each of the support rods, one end of each of the elastic elements is connected to the corresponding limiting groove, and the other end of each of the elastic elements is connected to the corresponding connecting rod.

8. The laser inner hole coaxiality detection device according to claim 2 or 7, characterized in that: The elastic element is a vortex spring, a steel wire torsion spring, or a straight-tube torsion spring.

9. A method for detecting inner hole coaxiality based on laser, implemented using the laser inner hole coaxiality detection device according to any one of claims 1 to 8, comprising the following steps: S1: Clamp the first connecting mechanism equipped with the laser transmitter and the second connecting mechanism equipped with the laser receiver into the inner hole to be inspected respectively; drive the elastic support assembly to radially expand through the push rod assembly to achieve three-point self-centering fixation; S2: starting the laser transmitter to emit a collimated laser beam, and the laser receiver receives the spot image and calculates the center coordinates of the spot; S3: moving the first connecting mechanism and the second connecting mechanism along the axis direction of the inner hole to collect light spot position data of at least three cross sections of the inner hole; S4: fitting the spot position data collected in step S3 using the least squares method to obtain the actual axis position; S5: Subtract the actual axis position from the theoretical axis position of the inner hole to obtain the coaxiality of the inner hole.

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