Online straightness detection device for cylindrical part

Abstract

The utility model discloses an on-line straightness detection device for a cylindrical part, which is characterized in that a cylindrical part head end positioning device and a cylindrical part tail end positioning device which are arranged on a lathe bed at an interval can respectively position two axial ends of the cylindrical part to be detected, so that the cylindrical part is kept in a suspended state; the sliding table driving device drives the detection sliding table installed on the lathe bed to slide linearly in the axial direction of the cylindrical part, and the cylindrical part edge position sensing device installed on the detection sliding table can detect the edge positions of the upper side and the lower side of the outer side face of the circumference of the cylindrical part and transmit detection data to the control system. The control system can calculate straightness data of the roller according to height data, detected by the roller edge position sensing device, of the upper edge and the lower edge of the cylindrical part and axial position data, fed back by the sliding table driving device, of the cylindrical part. The production precision of the cylindrical part is improved, the detection cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of manufacturing cylindrical parts, and in particular to an online straightness detection device for cylindrical parts. Background Technology

[0002] Cylindrical parts (such as rubber rollers and steel cores) require straightness inspection during production. The current method involves removing the finished cylindrical parts from the machine tool and placing them on the worktable of a projection inspection device. Projection inspection is then used to measure different points on the cylindrical parts, and the straightness data is calculated. This method is inconvenient, inefficient, and requires specialized projection inspection equipment. For cylindrical parts that fail inspection, they need to be reinstalled on the machine tool for reprocessing or repair. This significantly impacts production efficiency, leading to low production efficiency and repeated reinstallation and positioning, which also results in low dimensional accuracy of the cylindrical parts. Utility Model Content

[0003] To overcome the above-mentioned defects, this utility model provides an online straightness detection device for cylindrical parts. The online straightness detection device for cylindrical parts has a simple structure and can perform straightness detection on cylindrical parts on production machine tools. It has high detection efficiency and low detection cost, which is conducive to improving the production efficiency and dimensional accuracy of cylindrical parts.

[0004] The technical solution adopted by this utility model to solve its technical problem is as follows: an online straightness detection device for cylindrical parts, including a bed, a cylindrical part head end positioning device, a cylindrical part tail end positioning device, a detection slide, a cylindrical part edge position sensing device, a slide drive device, a control system, and a detection data output device. The cylindrical part head end positioning device and the cylindrical part tail end positioning device are installed alternately on the bed. The cylindrical part head end positioning device and the cylindrical part tail end positioning device can respectively position the two ends of the cylindrical part to be tested along the axial direction, so that the cylindrical part is kept in a suspended state. The detection slide can move along the cylindrical part. The part is mounted on the bed with axial linear sliding. The slide drive device drives the detection slide to slide continuously or intermittently. The cylindrical part edge position sensing device is mounted on the detection slide. The cylindrical part edge position sensing device can detect the position of the upper and lower edges of the outer circumference of the cylindrical part. The cylindrical part edge position sensing device communicates with the control system and transmits its detection data to the control system continuously or intermittently. The control system can calculate the straightness data of the roll based on the height data of the upper and lower edges of the cylindrical part detected by the roller edge position sensing device and the axial position data of the cylindrical part fed back by the slide drive device.

[0005] As a further improvement of this utility model, the cylindrical part edge position sensing device includes a front detection bracket, a rear detection bracket, a front laser through-beam sensor, and a rear laser through-beam sensor. The front laser through-beam sensor is mounted on the front detection bracket, and the rear laser through-beam sensor is mounted on the rear detection bracket. The front detection bracket and the rear detection bracket can be fixedly mounted on the detection slide, and the front detection bracket and the rear detection bracket are located on the front and rear sides of the outer circumference of the cylindrical part to be measured, respectively. The front laser through-beam sensor on the front detection bracket can form a detection signal for the upper and lower edge positions of the cylindrical part through laser light curtains arranged in a vertical direction.

[0006] As a further improvement of this utility model, the front laser through-beam sensor includes a first upper base, a first lower base, and a projector; the rear laser through-beam sensor includes a second upper base, a second lower base, and a receiver. The first upper base and the first lower base are fixedly mounted on the front detection bracket with adjustable heights, and the second upper base and the second lower base are fixedly mounted on the rear detection bracket with adjustable heights. The upper and lower ends of the projector are fixedly mounted on the first upper base and the first lower base, respectively, and the upper and lower ends of the receiver are fixedly mounted on the second upper base and the second lower base, respectively. The projector can emit several laser beams arranged vertically toward the receiver, and the upper and lower ends of the light curtain formed by the laser beams emitted by the projector exceed the upper and lower edges of the outer circumference of the cylindrical part, respectively. The receiver can receive the unobstructed portion of the laser beams emitted by the projector. The projector and the receiver communicate with the control system via wired or wireless communication, respectively.

[0007] As a further improvement of this utility model, the detection slide also includes a front mounting base and a rear mounting base that can slide horizontally along the radial direction of the cylindrical part, and the front detection bracket and the rear detection bracket are respectively mounted on the front mounting base and the rear mounting base.

[0008] As a further improvement of this utility model, the front mounting base and the rear mounting base are respectively provided with vertically extending front sliding grooves and rear sliding grooves. The front detection bracket and the rear detection bracket are respectively slidably inserted into the front sliding grooves and the rear sliding grooves. The bottom surfaces of the front sliding grooves and the rear sliding grooves are respectively provided with connecting screw holes. The front detection bracket and the rear detection bracket are respectively provided with elongated holes extending in the vertical direction. The front locking bolt and the rear locking bolt are respectively inserted into the elongated holes of the front detection bracket and the rear detection bracket. The front locking bolt and the rear locking bolt are respectively threadedly connected to the connecting screw holes on the bottom surfaces of the front sliding grooves and the rear sliding grooves for locking and positioning.

[0009] As a further improvement of this utility model, one side wall of the front slide groove and the rear slide groove is a vertical wall extending in the vertical direction, and the other side wall of the front slide groove and the rear slide groove is an inclined wall with an angle to the vertical direction, and a flared mouth is formed between the vertical wall and the inclined wall with the upper opening being larger than the lower opening. One side wall of the lower end of the front detection bracket and the rear detection bracket is a vertical wall, and the other side wall of the lower end of the front detection bracket and the rear detection bracket is an inclined wall that fits against the other side wall of the front slide groove and the rear slide groove.

[0010] As a further improvement of this utility model, the bed is provided with a first guide rail extending along the axial direction of the cylindrical part to be tested, and the detection slide is provided with a second guide rail extending horizontally and radially along the cylindrical part to be tested. The detection platform is mounted on the first guide rail, and the front mounting seat and the rear mounting seat are mounted on the second guide rail. The front mounting seat and the rear mounting seat are also provided with locking handles, which can lock and position the front mounting seat and the rear mounting seat with the detection slide at any position.

[0011] As a further improvement of this utility model, the cylindrical part head-end positioning device includes a machine tool headstock and a headstock ejector pin disposed on the headstock, and the cylindrical part tail-end positioning device includes a machine tool tailstock and a tailstock ejector pin disposed on the tailstock. The headstock ejector pin and the tailstock ejector pin are coaxial and face each other. The tailstock can be slidably mounted on the machine bed to change the distance between the headstock ejector pin and the tailstock ejector pin. The cylindrical part tail-end positioning device also includes a tailstock feed adjustment mechanism, which can drive the tailstock to slide on the machine bed and fix the tailstock in place to the machine bed.

[0012] As a further improvement of this utility model, the slide drive device includes a lead screw and nut mechanism and a motor. The lead screw of the lead screw and nut mechanism is rotatably mounted on the bed, and the lead screw of the lead screw and nut mechanism extends along the axial direction of the cylindrical part to be tested. The nut of the lead screw and nut mechanism is fixedly connected to the test slide. The motor drives the lead screw to rotate, and the control system controls the forward and reverse rotation and start and stop of the motor.

[0013] As a further improvement of this utility model, an operating table is also fixedly installed on one side of the bed by a bracket. The detection data output device is a monitor installed on the operating table. The operating table is also equipped with a keyboard and mouse. The control system is a computer located on the bed. The computer is connected and communicates with the monitor, keyboard and mouse. The monitor can display detection data, and the keyboard and mouse can be used to input preset data.

[0014] The beneficial effects of this utility model are as follows: This utility model installs a detection slide on a machine tool used for producing cylindrical parts, and installs a cylindrical part edge position sensing device on the detection slide. The cylindrical part edge position sensing device senses the height data of the upper and lower edges of the cylindrical part at different axial positions through laser light curtain projection. The control system combines these data with the axial position data of the sliding detection slide to finally draw a continuous diameter measurement image of the cylindrical part, i.e., the main view of the cylindrical part. Then, the straightness data of the cylindrical part can be analyzed by calculation. This straightness detection device can realize online detection of the straightness of cylindrical parts on the production machine tool without repeated disassembly and installation of cylindrical parts, which has high detection efficiency and avoids installation errors caused by repeated installation, which is conducive to improving the production accuracy of cylindrical parts. Moreover, the detection device has a simple structure and low manufacturing cost, avoiding the use of projection detection equipment for detection, which greatly reduces the detection cost. Furthermore, the detection device can communicate with the control system of the cylindrical part machine tool to realize the production of cylindrical parts by detecting and correcting simultaneously, which greatly improves production efficiency. Attached Figure Description

[0015] Figure 1 This is a three-dimensional view of the structural principle of this utility model;

[0016] Figure 2 This is a front view illustrating the structural principle of this utility model;

[0017] Figure 3 for Figure 2 Sectional view along line AA;

[0018] Figure 4 for Figure 3 Enlarged view of section B in the middle;

[0019] Figure 5 This is a top view of the structural principle of this utility model. Detailed Implementation

[0020] Example: An online straightness testing device for cylindrical parts includes a bed 1, a cylindrical part head end positioning device, a cylindrical part tail end positioning device, a testing slide 2, a cylindrical part edge position sensing device, a slide drive device, a control system, and a testing data output device. The cylindrical part head end positioning device and the cylindrical part tail end positioning device are installed alternately on the bed 1. The cylindrical part head end positioning device and the cylindrical part tail end positioning device can respectively position the two ends of the cylindrical part 3 under test along the axial direction, keeping the cylindrical part in a suspended state. The testing slide 2 can slide linearly along the axial direction of the cylindrical part. The roller is mounted on the bed 1. The slide drive device drives the detection slide 2 to slide continuously or intermittently. The cylindrical part edge position sensing device is mounted on the detection slide 2. The cylindrical part edge position sensing device can detect the position of the upper and lower edges of the outer circumference of the cylindrical part. The cylindrical part edge position sensing device communicates with the control system and transmits its detection data to the control system continuously or intermittently. The control system can calculate the straightness data of the roller based on the height data of the upper and lower edges of the cylindrical part detected by the roller edge position sensing device and the axial position data of the cylindrical part fed back by the slide drive device.

[0021] During the machining of cylindrical parts on a machine tool, the axial movement of the detection slide 2 drives the cylindrical part edge position sensing device to sense the radial upper and radial lower points at different axial positions of the cylindrical part, thereby realizing the detection of the diameter of the cylindrical part at different positions. After the cylindrical part edge position sensing device moves from one end of the cylindrical part to the other end, it detects multiple points and presents these points in a two-dimensional coordinate system. These points form a continuous diameter measurement image, which can then be used to analyze the straightness data of the cylindrical part for machining.

[0022] The cylindrical part edge position sensing device includes a front detection bracket 4, a rear detection bracket 5, a front laser beam sensor 6, and a rear laser beam sensor 7. The front laser beam sensor 6 is mounted on the front detection bracket 4, and the rear laser beam sensor 7 is mounted on the rear detection bracket 5. The front detection bracket 4 and the rear detection bracket 5 are respectively fixedly mounted on the detection slide 2, and are located on the front and rear sides of the outer circumference of the cylindrical part 3 to be measured. The front laser beam sensor 6 on the front detection bracket 4 and the rear laser beam sensor 7 on the rear detection bracket 5 can form a laser beam with the upper and lower edges of the cylindrical part's circumference through a vertically arranged laser light curtain. The front laser beam sensor 6 and the rear laser beam sensor 7 each form multiple laser beams arranged vertically, which in turn form a laser light curtain that shines through the light curtain on both sides of the cylindrical part. The parts blocked by the cylindrical part will not generate a signal, thus allowing the upper and lower edges of the cylindrical part's circumference to be captured, thereby obtaining the diameter data of the cylindrical part.

[0023] The front laser through-beam sensor 6 includes a first upper base 61, a first lower base 62, and a projector 63. The rear laser through-beam sensor 7 includes a second upper base 71, a second lower base 72, and a receiver 73. The first upper base 61 and the first lower base 62 are height-adjustable and fixedly mounted on the front detection bracket 4. The second upper base 71 and the second lower base 72 are height-adjustable and fixedly mounted on the rear detection bracket 5. The upper and lower ends of the projector 63 are respectively fixedly mounted on the first upper base 61 and the second lower base 62. On a lower base 62, the upper and lower ends of the receiver 73 are fixedly mounted on the second upper base 71 and the second lower base 72, respectively. The projector 63 can emit several laser beams arranged vertically toward the receiver 73, and the upper and lower ends of the light curtain formed by the laser beams emitted by the projector 63 extend beyond the upper and lower edges of the outer circumference of the cylindrical part. The receiver 73 can receive the unobstructed portion of the laser beams emitted by the projector 63. The projector 63 and the receiver 73 communicate with the control system via wired or wireless communication. By adjusting the vertical height of the first and second upper bases and the first and second lower bases on the front and rear detection brackets 5, the diameter detection of different cylindrical parts can be adapted to ensure that the laser light curtain formed by the laser beams completely covers the cylindrical part.

[0024] The detection slide 2 also includes a front mounting base 8 and a rear mounting base 9 that can slide horizontally along the radial direction of the cylindrical part. The front detection bracket 4 and the rear detection bracket 5 are respectively mounted on the front mounting base 8 and the rear mounting base 9. The front mounting base 8 and the rear mounting base 9 move back and forth, causing the front laser through-beam sensor 6 and the rear laser through-beam sensor 7 to move radially along the cylindrical part, ensuring that the two accurately receive signals through beams, while adapting to the detection of cylindrical parts of different diameters and avoiding obstacles when installing parts.

[0025] The front mounting base 8 and the rear mounting base 9 are respectively provided with vertically extending front sliding grooves 81 and rear sliding grooves 91. The front detection bracket 4 and the rear detection bracket 5 are slidably inserted into the front sliding grooves 81 and rear sliding grooves 91, respectively. The bottom surfaces of the front sliding grooves 81 and rear sliding grooves 91 are respectively provided with connecting screw holes. The front detection bracket 4 and the rear detection bracket 5 are respectively provided with elongated holes extending vertically. Front locking bolts 82 and rear locking bolts 92 are respectively inserted into the elongated holes on the bottom surfaces of the front detection bracket 4 and the rear detection bracket 91, respectively, and are threadedly connected to the connecting screw holes on the bottom surfaces of the front sliding grooves 81 and the rear sliding grooves 91 for locking and positioning. This structure allows for adjustment of the overall height of the front detection bracket 4 and the rear detection bracket 5, thereby enabling adjustment of the overall height of the front laser through-beam sensor 6 and the rear laser through-beam sensor 7, adapting to the installation height of different cylindrical parts.

[0026] One side wall of the front slide groove 81 and the rear slide groove 91 is a vertical wall extending in the vertical direction, and the other side wall of the front slide groove 81 and the rear slide groove 91 is an inclined wall forming an angle with the vertical direction. The vertical wall and the inclined wall form a flared opening at the upper end that is larger than the lower end. One lower side wall of the front detection bracket 4 and the rear detection bracket 5 is a vertical wall, and the other lower side wall of the front detection bracket 4 and the rear detection bracket 5 is an inclined wall that fits against the other side wall of the front slide groove 81 and the rear slide groove 91. This structure facilitates the insertion of the lower ends of the front detection bracket 4 and the rear detection bracket 5 into the front slide groove 81 and the rear slide groove 91. As the front detection bracket 4 and the rear detection bracket 5 are inserted downwards, the front slide groove 81 and the rear slide groove 91 gradually clamp the front detection bracket 4 and the rear detection bracket 5, achieving proper positioning.

[0027] The bed is provided with a first guide rail 10 extending axially along the cylindrical part 3 to be tested, and the detection slide 2 is provided with a second guide rail 11 extending radially horizontally along the cylindrical part 3 to be tested. The detection platform is mounted on the first guide rail 10, and the front mounting base 8 and the rear mounting base 9 are mounted on the second guide rail 11. The front mounting base 8 and the rear mounting base 9 are each provided with a locking handle 21, which can lock and position the front mounting base 8 and the rear mounting base 9 to the detection slide 2 at any position. The first guide rail 10 and the second guide rail 11 guide the sliding of the detection slide 2 and the front mounting base 8 and the rear mounting base 9, ensuring that they slide in a straight line and guaranteeing detection accuracy.

[0028] The cylindrical part head-end positioning device includes a headstock 12 of the machine tool and a headstock ejector pin 13 disposed on the headstock 12. The cylindrical part tail-end positioning device includes a tailstock 14 of the machine tool and a tailstock ejector pin 15 disposed on the tailstock 14. The headstock ejector pin 13 and the tailstock ejector pin 15 are coaxial and face each other. The tailstock 14 can be slidably mounted on the bed 1 to change the distance between the headstock ejector pin 13 and the tailstock ejector pin 15. The cylindrical part tail-end positioning device also includes a tailstock 14 feed adjustment mechanism. The tailstock 14 feed adjustment mechanism can drive the tailstock 14 to slide on the bed 1 and fix the tailstock 14 in place to the bed 1. The cylindrical part can be positioned by pressing the center of both ends of the cylindrical part with the headstock ejector pin 13 and the tailstock ejector pin 15, without obstructing the axial ends of the cylindrical part. Alternatively, a chuck can be used to clamp the shoulders of both ends of the cylindrical part. The chuck and ejector pins can work together to position both ends of the cylindrical part. At the same time, the cylindrical part can be rotated to detect its roundness.

[0029] The slide drive device includes a lead screw and nut mechanism and a motor. The lead screw of the lead screw and nut mechanism is rotatably mounted on the bed 1, and the lead screw of the lead screw and nut mechanism extends axially along the cylindrical part 3 to be tested. The nut of the lead screw and nut mechanism is fixedly connected to the detection slide 2. The motor drives the lead screw to rotate, and the control system controls the forward and reverse rotation and start and stop of the motor.

[0030] An operating table 16 is also fixedly installed on one side of the bed 1 by a bracket. The detection data output device is a display 18 installed on the operating table 16. The operating table 16 is also equipped with a keyboard 19 and a mouse 20. The control system is a computer 17 located on the bed 1. The computer 17 is connected and communicates with the display 18, keyboard 19 and mouse 20. The display 18 can display detection data, and the keyboard 19 and mouse 20 can be used to input preset data.

[0031] The computer 17 performs calculations and analysis on the test data to obtain the straightness data of the cylindrical part, which is then displayed on the monitor 18. Preset data, such as standard straightness data and standard diameter data of the cylindrical part, can also be input via the keyboard 19 and mouse 20. The computer 17 can directly give the test judgment conclusion by comparing the test data with the standard data. Alternatively, an integrated device of industrial control computer and touch screen can be used, where the industrial control computer performs calculations and analysis, and the touch screen displays and inputs data.

Claims

1. A device for on-line straightness detection of a cylindrical part, characterized by: The application relates to a cylinder part edge position sensing device and a cylinder part straightness detection device, which comprises a bed body (1), a cylinder part head end positioning device, a cylinder part tail end positioning device, a detection sliding table (2), a cylinder part edge position sensing device, a sliding table driving device, a control system and a detection data output device, the cylinder part head end positioning device and the cylinder part tail end positioning device are installed on the bed body at intervals, the cylinder part head end positioning device and the cylinder part tail end positioning device can respectively position the two axial ends of a cylinder part (3) to be detected so that the cylinder part is kept in a suspended state, the detection sliding table is installed on the bed body and can linearly slide along the axial direction of the cylinder part, the sliding table driving device drives the continuous or intermittent sliding of the detection sliding table, the cylinder part edge position sensing device is installed on the detection sliding table, the cylinder part edge position sensing device can detect the upper and lower edge positions of the outer circumferential surface of the cylinder part, the cylinder part edge position sensing device communicates with the control system and continuously or intermittently transmits the detection data to the control system, and the control system can calculate the straightness data of the cylinder part according to the upper and lower edge height data of the cylinder part detected by the roller edge position sensing device and the axial position data of the cylinder part fed back by the sliding table driving device.

2. The on-line straightness detection device for cylindrical parts according to claim 1, characterized in that: The cylinder part edge position sensing device comprises a front detection support (4), a rear detection support (5), a front laser transmission type sensor (6) and a rear laser transmission type sensor (7), the front laser transmission type sensor is installed on the front detection support, the rear laser transmission type sensor is installed on the rear detection support, the front detection support and the rear detection support can be respectively fixedly installed on the detection sliding table, and the front detection support and the rear detection support are respectively located on the front side and the rear side of the outer circumferential surface of the cylinder part to be detected, the front laser transmission type sensor on the front detection support can form a cylinder part circumferential upper and lower edge position detection signal by transmitting a laser curtain arranged in a vertical direction with the rear laser transmission type sensor on the rear detection support.

3. The on-line straightness detection apparatus for cylindrical parts according to claim 2, characterized in that: The front laser transmission type sensor comprises a first upper base (61), a first lower base (62) and a light projector (63), the rear laser transmission type sensor comprises a second upper base (71), a second lower base (72) and a light receiver (73), the first upper base and the first lower base are fixedly installed on the front detection support and can be adjusted in height, the second upper base and the second lower base are fixedly installed on the rear detection support and can be adjusted in height, the upper and lower ends of the light projector are respectively fixedly installed on the first upper base and the first lower base, the upper and lower ends of the light receiver are respectively fixedly installed on the second upper base and the second lower base, the light projector can emit a plurality of laser beams arranged in a vertical direction towards the light receiver, and the upper and lower ends of the laser curtain formed by the laser beams emitted by the light projector exceed the upper and lower edges of the outer circumferential surface of the cylinder part, the light receiver can receive the unobstructed part of the laser beams emitted by the light projector, and the light projector and the light receiver respectively communicate with the control system in a wired or wireless mode.

4. The on-line straightness detection apparatus for cylindrical parts according to claim 2, characterized in that: The front mounting base (8) and the rear mounting base (9) can also horizontally slide along the radial direction of the cylinder part on the detection sliding table, and the front detection support and the rear detection support are respectively installed on the front mounting base and the rear mounting base.

5. The on-line straightness detection apparatus for cylindrical parts according to claim 4, characterized in that: The front mounting seat and the rear mounting seat are respectively provided with vertically extending front sliding grooves (81) and rear sliding grooves (91), the front detection support and the rear detection support are respectively inserted into the front sliding grooves and the rear sliding grooves and can slide up and down, the bottom surfaces of the front sliding grooves and the rear sliding grooves are respectively provided with connecting screw holes, the front detection support and the rear detection support are respectively provided with vertically extending long holes, the front locking bolts (82) and the rear locking bolts (92) are respectively inserted into the long holes of the front detection support and the rear detection support, and the front locking bolts and the rear locking bolts are respectively threadedly connected with the connecting screw holes on the bottom surfaces of the front sliding grooves and the rear sliding grooves to be locked and positioned.

6. The on-line straightness detection apparatus for cylindrical parts according to claim 5, characterized in that: One side wall of the front sliding groove and the rear sliding groove is a vertical wall extending in the vertical direction, the other side wall of the front sliding groove and the rear sliding groove is an inclined wall having an angle with the vertical direction, and the vertical wall and the inclined wall form a horn opening with a larger upper end opening than a lower end opening, and one side wall at the lower end of the front detection support and the rear detection support is a vertical wall, and the other side wall at the lower end of the front detection support and the rear detection support is an inclined wall matched with the other side wall of the front sliding groove and the rear sliding groove.

7. The on-line straightness detection apparatus for cylindrical parts according to claim 4, wherein: The bed is provided with a first guide rail (10) extending in the axial direction of the cylindrical part to be detected, the detection sliding table is provided with a second guide rail (11) extending in the horizontal radial direction of the cylindrical part to be detected, the detection sliding table is installed on the first guide rail, the front mounting seat and the rear mounting seat are installed on the second guide rail, the front mounting seat and the rear mounting seat are further respectively provided with locking handles (21) installed thereon, and the locking handles can lock and position the front mounting seat and the rear mounting seat at any position with the detection sliding table.

8. The on-line straightness detection apparatus for cylindrical parts according to claim 1, wherein: The cylindrical part head end positioning device comprises a headstock (12) of the machine tool and a headstock center pin (13) provided on the headstock, the cylindrical part tail end positioning device comprises a tailstock (14) of the machine tool and a tailstock center pin (15) provided on the tailstock, the headstock center pin and the tailstock center pin are coaxial and opposite to each other, the tailstock is slidably installed on the bed body to change the distance between the headstock center pin and the tailstock center pin, and the cylindrical part tail end positioning device further comprises a tailstock feed adjusting mechanism, which can drive the tailstock to slide on the bed body and fix and position the tailstock in place.

9. The on-line straightness detection apparatus for cylindrical parts according to claim 1, wherein: The sliding table driving device comprises a screw nut mechanism and a motor, the screw rod of the screw nut mechanism is rotatably installed on the bed body and extends in the axial direction of the cylindrical part to be detected, the nut of the screw nut mechanism is fixedly connected with the detection sliding table, the motor drives the screw rod to rotate, and the control system controls the forward and reverse rotation and start and stop of the motor.

10. The on-line straightness detection apparatus for cylindrical parts according to claim 1, characterized in that: One side of the bed body is further fixedly provided with an operation table (16) through a support, the detection data output device is a display (18) installed on the operation table, the operation table is further provided with a keyboard (19) and a mouse (20), the control system is a computer (17) provided on the bed body, the computer is connected and communicates with the display, the keyboard and the mouse, the display can display the detection data, and the keyboard and the mouse can be used for inputting preset data.

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