A positioning device for end turning of metal bar

Abstract

The present application relates to the field of metal processing, and particularly relates to a metal bar end turning positioning device, which comprises a lathe, a bottom plate and a mounting block, etc.; the lathe is provided with a tool carriage and a chuck; the tool carriage is connected with the bottom plate; and the bottom plate is connected with the mounting block. In the initial stage, the straight jaw and the two arc jaws support the round bar on the side away from the starting end, without hindering the turning of the end face of the round bar, and avoiding the deflection of the starting end of the round bar from affecting the turning; after the round bar is turned for a distance, the positioning cylinder temporarily supports the starting end of the round bar, the two arc jaws are opened to provide a space for the tool to change position, the position of the tool is exchanged with the straight jaw and the arc jaw, and the straight jaw and the arc jaw are close to the starting end of the round bar, so as to reduce the deflection of the starting end from being transmitted to the turning position of the tool when the straight jaw and the two arc jaws are far away from the starting end to support, thereby avoiding affecting the turning.

Description

Technical Field

[0001] This invention relates to the field of metal processing, and more particularly to a positioning device for turning the end of a metal bar. Background Technology

[0002] When turning metal bars, one end of the bar is fixed to the lathe by a chuck (fixed end), and the rotation of the chuck causes the bar to rotate. The other end of the bar (starting end) is usually not fixed to facilitate the turning of the end face. The follower post is a component that moves synchronously with the cutting tool, supports the bar near the turning point, and prevents the bar from wobble due to its rotation. The follower post is usually set on the side of the cutting tool facing the chuck so as not to obstruct the cutting tool from turning the end face of the starting end of the bar. However, as the turning progresses, the follower post moves away from the starting end of the round bar, and the rotating starting end of the round bar begins to wobble, while the cutting tool gradually moves closer to the starting end of the round bar. The farther the follower post is from the starting end, the greater the wobble at the starting end, which can still easily affect the cutting tool and reduce the turning quality of the bar. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, when the tool holder is far away from the starting end of the round bar, the starting end deflection increases, which affects the turning of the tool on the side near the starting end and reduces the turning quality of the bar, the present invention provides a positioning device for turning the end of a metal bar.

[0004] The technical implementation scheme of the present invention is as follows: a positioning device for turning the end of a metal bar includes a lathe; a tool holder and a chuck are mounted on the lathe; a cutting tool is mounted on the tool holder; it also includes a base plate, a mounting block, a column, a positioning cylinder, and an adjustment assembly; the base plate is connected to the tool holder; the mounting block is connected to the base plate; an adjustment assembly for adjusting the position of the mounting block is provided on the base plate; a straight jaw is slidably connected to the mounting block; a tension spring is connected between the straight jaw and the mounting block; a positioning wheel one is rotatably connected to the straight jaw; two arc jaws are elastically rotatably connected to the mounting block via torsion springs; a positioning wheel two is rotatably connected to the end of each arc jaw; the positioning wheel one and the two positioning wheels two are triangularly distributed; a transverse component is mounted on the base plate; a column is fixedly connected to the moving end of the transverse component; a rotating ring is rotatably connected to the column; a bearing is connected to the rotating ring, and the outer ring of the bearing is fixedly connected to the rotating ring; a positioning cylinder for fixing the end of the bar is fixedly connected to the inner ring of the bearing; the positioning cylinder is frustum-shaped, with the large circular surface facing the round bar.

[0005] More preferably, the adjustment assembly includes: a lateral translation block, a mounting plate, and a longitudinal translation block; at least two lateral translation blocks are slidably connected to the base plate; all lateral translation blocks are fixedly connected to the mounting plate; at least two longitudinal translation blocks are slidably connected to the mounting plate; and all longitudinal translation blocks are connected to the mounting block.

[0006] More preferably, it also includes a hook, a support rod, a connecting strip, and an electric telescopic rod; the hook is rotatably connected to the upper arc-shaped clamp; a groove adapted to the hook is opened on the top of the mounting block; a connecting strip is fixedly connected to the swivel ring; a support rod for supporting the rod is slidably connected to the connecting strip; an electric telescopic rod is installed on the connecting strip; the telescopic end of the electric telescopic rod is fixedly connected to the support rod.

[0007] More preferably, it also includes connector one and connector two; two liquid outlets one are provided on the straight jaw; positioning wheel one is located between the two liquid outlets one; connector one is installed on the straight jaw, and connector one is connected to liquid outlet one; two liquid outlets two are provided on each arc jaw; positioning wheel two is located between the two liquid outlets two; connector two is installed on each arc jaw, and connector two is connected to liquid outlet two; both connector one and connector two are externally connected to coolant supply pipes.

[0008] More preferably, it also includes baffles; two baffles for blocking chips are fixed to the base plate; and a mounting block is located between the two baffles.

[0009] More preferably, the inner wall of the positioning cylinder is covered with a wear-resistant rubber layer.

[0010] More preferably, the telescopic ends of the support rod and the electric telescopic rod are rotatably connected, and rolling friction is formed between the support rod and the round bar that is supported and translated.

[0011] More preferably, the base plate is provided with multiple mounting holes for adjusting the installation position.

[0012] More preferably, the swivel ring and bearing are detachably connected to allow for the replacement of positioning cylinders of different diameters and lengths, thereby accommodating a wider range of bar sizes.

[0013] More preferably, the side of the baffle facing the rod is covered with absorbent felt.

[0014] Compared with the prior art, the present invention has the following advantages: Initially, the straight jaw and the two arc jaws support the round bar on the side away from the starting end, which does not hinder the cutting tool from machining the end face of the round bar and avoids the starting end of the round bar from swaying and affecting the turning; after the round bar is turned a certain distance, the positioning cylinder temporarily supports the starting end of the round bar, and the two arc jaws open to make room for the cutting tool to change position, so that the cutting tool and the straight jaw and arc jaws interchange positions, and the straight jaw and arc jaws are close to the starting end of the round bar, so as to reduce the sway generated at the starting end when the straight jaw and the two arc jaws move away from the starting end for support due to the turning movement, which is transmitted to the cutting position of the cutting tool, thereby avoiding affecting the turning. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention mounted on the tool post of a lathe; Figure 2 This is a three-dimensional structural diagram of the cutting tool, base plate, and mounting block of the present invention; Figure 3 This is a schematic diagram from a first perspective of the positioning device for turning the end of a metal bar according to the present invention; Figure 4 This is a schematic diagram from a second perspective of the positioning device for turning the end of a metal bar according to the present invention; Figure 5 This is a schematic diagram of the internal structure of the mounting block of the present invention; Figure 6 This is a three-dimensional structural diagram of the straight jaw and the arc jaw of the present invention; Figure 7 This is a top view of the cutting tool, mounting block, and arc-shaped clamp of the present invention; Figure 8 This is a schematic diagram of the arc-shaped gripper avoiding the cutting tool according to the present invention; Figure 9 This is a schematic diagram of the support rod supporting the rod material according to the present invention.

[0016] The components in the attached diagram are labeled as follows: 1-Lathe, 11-Tool holder, 12-Lathe tool, 13-Chuck, 2-Base plate, 21-Transverse translation block, 22-Mounting plate, 23-Longitudinal translation block, 24-Baffle, 3-Mounting block, 31-Straight jaw, 311-Positioning wheel one, 312-Joint one, 313-Tension spring, 32-Arc jaw, 321-Positioning wheel two, 322-Joint two, 323-Hook, 300-Slot, 301-Outlet one, 302-Outlet two, 4-Column, 41-Transverse translation assembly, 42-Rotating ring, 5-Positioning cylinder, 51-Bearing, 6-Support rod, 61-Connecting strip, 62-Electric telescopic rod. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example: A positioning device for end turning of a metal bar, such as... Figures 1-9 As shown, it includes a lathe 1; the lathe 1 is equipped with a tool post 11 and a chuck 13; the tool post 11 is equipped with a cutting tool 12; It also includes a base plate 2, a mounting block 3, a column 4, a positioning cylinder 5, and an adjustment assembly; the base plate 2 is bolted to the tool holder 11; the mounting block 3 is connected to the base plate 2; the adjustment assembly is provided on the base plate 2 for adjusting the position of the mounting block 3 laterally and longitudinally; a straight clamping jaw 31 is slidably connected to the mounting block 3; a tension spring 313 is connected between the straight clamping jaw 31 and the mounting block 3; a positioning wheel 311 is rotatably connected to the straight clamping jaw 31; two arc-shaped clamping jaws 32 are elastically rotatably connected to the mounting block 3 via torsion springs; a positioning wheel 321 is rotatably connected to the end of each arc-shaped clamping jaw 32; Positioning wheel 311 and two positioning wheels 321 are arranged in a triangle for positioning the bar stock; a transverse moving assembly 41 is installed on the base plate 2; the transverse moving assembly 41 is a screw-slider structure, which is driven by a motor to rotate the screw, causing the slider to move laterally along the screw; a column 4 is fixedly connected to the moving part of the transverse moving assembly 41; a rotating ring 42 is rotatably connected to the column 4; the rotating ring 42 is driven by the built-in motor of the column 4 and rotates relative to the column 4; a bearing 51 is connected to the rotating ring 42, and the outer ring of the bearing 51 is fixedly connected to the rotating ring 42; a positioning cylinder 5 is fixedly connected to the inner ring of the bearing 51; the positioning cylinder 5 is frustum-shaped, with the large circular surface facing the round bar stock.

[0019] The adjustment assembly includes: a lateral translation block 21, a mounting plate 22, and a longitudinal translation block 23; two lateral translation blocks 21 are slidably connected to the base plate 2; all lateral translation blocks 21 are fixedly connected to the mounting plate 22; two longitudinal translation blocks 23 are slidably connected to the mounting plate 22; both the lateral translation blocks 21 and the longitudinal translation blocks 23 are driven to move by electric push rods; all longitudinal translation blocks 23 are connected to the mounting block 3 by bolts.

[0020] It also includes a hook 323, a support rod 6, a connecting strip 61, and an electric telescopic rod 62; the hook 323 is rotatably connected to the upper arc-shaped clamp 32; the top of the mounting block 3 has a slot 300 that matches the hook 323; the connecting strip 61 is welded to the rotating ring 42; the connecting strip 61 and the bearing 51 are distributed at 90 degrees around the column 4; the support rod 6 is slidably connected to the connecting strip 61; the electric telescopic rod 62 is installed on the connecting strip 61; the telescopic end of the electric telescopic rod 62 is fixedly connected to the support rod 6, and the support rod 6 is adjusted up and down along the connecting strip 61.

[0021] It also includes connector 312 and connector 322; the straight jaw 31 has two liquid outlets 301 on the side facing the bar; positioning wheel 311 is located between the two liquid outlets 301; connector 312 is installed on the straight jaw 31 and is connected to the liquid outlet 301; each arc jaw 32 has two liquid outlets 302 on the side facing the bar; positioning wheel 321 is located between the two liquid outlets 302; each arc jaw 32 has a connector 322 installed on it and is connected to the liquid outlet 302; both connector 312 and connector 322 are externally connected to coolant supply pipes.

[0022] It also includes baffles 24; two baffles 24 are bolted to the base plate 2 to prevent chips from flying; the mounting block 3 is located between the two baffles 24.

[0023] The inner wall of the positioning cylinder 5 is covered with a wear-resistant rubber layer to reduce wear on the starting end of the round bar.

[0024] The extension ends of the support rod 6 and the electric telescopic rod 62 are rotatably connected, and rolling friction is formed between the support rod 6 and the round bar that it supports and translates, thereby reducing wear.

[0025] The base plate 2 is provided with multiple mounting holes to facilitate adjustment of its relative mounting position with the tool holder 11.

[0026] The swivel ring 42 is detachably connected to the bearing 51 to allow for the replacement of positioning cylinders 5 with different diameters and lengths, thereby accommodating a wider range of bar sizes.

[0027] The side of the baffle 24 facing the bar is covered with absorbent felt to prevent coolant from splashing onto the baffle 24 and being reflected a second time, thus avoiding further contamination of the workpiece and equipment.

[0028] The turning process for round bars is as follows: First, the worker clamps and secures one end (fixed end) of the round bar using chuck 13. Then, the tool holder 11 is adjusted to the other end (starting end) of the round bar, so that the starting end of the round bar is engaged between the straight jaw 31 and the two curved jaws 32. The straight jaw 31 adapts to the size of the round bar via tension spring 313, and the two curved jaws 32 adapt via torsion springs, causing positioning wheels 1 311 and 2 321 to clamp the starting end of the round bar. Next, the cutting tool 12 is installed on the tool holder 11, and then the control mechanism is activated. The disc 13 drives the round bar to rotate, and then controls the tool holder 11 to move horizontally towards the fixed end of the round bar on the lathe 1. The cutting tool 12 first turns the end face of the round bar, and then moves the tool from the starting end of the round bar to the fixed end. During the process, the base plate 2 and all the parts on it mounted on the tool holder 11 move horizontally. Positioning wheel 1 311 and positioning wheel 2 321 are located on one side of the cutting tool 12 and support the round bar as the cutting tool 12 moves, so that the area near the cutting tool 12 does not wobble when the round bar rotates.

[0029] When the straight jaw 31 and the two curved jaws 32 move a certain distance with the cutting tool 12, they are far from the starting end of the round bar. The starting end of the rotating round bar begins to wobble. The cutting tool 12 is closer to the starting end, while the straight jaw 31 and curved jaws 32 are closer to the ending end. The farther the straight jaw 31 and curved jaws 32 are from the starting end, the greater the wobble at the starting end, which can still easily affect the turning operation of the cutting tool 12. Therefore, it is necessary to swap the positions of the cutting tool 12 with the straight jaw 31 and curved jaws 32, so that the straight jaw 31 and curved jaws 32 are closer to the starting end of the round bar, in order to reduce the wobble at the starting end being transmitted to the turning position of the cutting tool 12. The specific process is as follows: As the tool holder 11 moves, and the cutting tool 12 cuts a certain distance on the round bar, the column 4 approaches the starting end of the round bar. At this time, the motor inside the column 4 drives the rotating ring 42 to rotate 90 degrees, making the positioning cylinder 5 and the round bar coaxial. Then, as the tool holder 11 continues to move, the positioning cylinder 5 gradually covers the starting end of the round bar. After the starting end of the round bar extends into the positioning cylinder 5, it moves to a cross-sectional position where its outer diameter matches the inner diameter of the positioning cylinder 5. The starting end of the round bar presses against the inner wall of the positioning cylinder 5, and the positioning cylinder 5 provides temporary support for the starting end of the round bar, preventing it from swaying. At the same time, the rotating round bar drives the positioning cylinder 5 and the inner ring of the bearing 51. The outer ring of the bearing 51 rotates relative to the outer ring, and then the tool holder 11 continues to move, while the round bar remains relatively stationary. At this time, the end of the round bar presses against the positioning cylinder 5, the slider of the transverse component 41 is in a free state, the lead screw of the transverse component 41 moves relative to the slider, and the column 4, positioning cylinder 5 and bearing 51 remain stationary, supporting the starting end of the round bar; at the same time, the longitudinal translation block 23 drives the mounting block 3 to move backward away from the round bar, the tension spring 313 extends, keeping the positioning wheel 311 of the straight jaw 31 pressed on the round bar, while the positioning wheel 321 of the arc jaw 32 moves along the arc length direction of the round bar, and the two arc jaws 32 move away from each other, as... Figure 8As shown, the two positioning wheels 321 roll to the top and bottom of the round bar, making room for the cutting tool 12 to change position. At this time, the starting end of the round bar is temporarily supported by the positioning cylinder 5. Even though the support effect of the straight jaw 31 and the two arc jaws 32 on the round bar is weakened, the starting end of the round bar does not wobble. Then, the transverse translation block 21 is controlled to translate relative to the base plate 2 towards the positioning cylinder 5, driving the mounting plate 22, longitudinal translation block 23, mounting block 3, straight jaw 31 and arc jaw 32 to move. The cutting tool 12 passes through the changing position space made up by the two arc jaws 32. The cutting tool 12 changes position with the straight jaw 31 and arc jaw 32. The straight jaw 31 and arc jaw 32 move closer to the starting end of the round bar. During the process, the cutting tool 12 continues to turn the round bar, ensuring cutting continuity and eliminating the need for repositioning the tool, thereby improving the turning quality of the bar surface. After the changing position is completed, the longitudinal translation block 23 drives the mounting block 3. The bar is moved closer to the resetting point. The tension spring 313 is compressed by the mounting block 3 and the straight jaw 31. The two arc jaws 32 are adaptively clamped by the torsion spring to adapt to the size of the bar after turning. The positioning wheel 1 311 rolls along the arc length of the bar and re-forms a triangular distribution with the two positioning wheels 2 321 to support the bar. Then, the transverse translation block 21 stops moving. The mounting block 3, the straight jaw 31 and the two arc jaws 32 are driven to move by the tool holder 11 and follow the direction of the cutting tool 12. Then, the motor drive screw of the transverse component 41 rotates, causing the slider to move the column 4 away from the starting end of the bar. The positioning cylinder 5 is disengaged from the starting end of the bar. Then, the motor drive ring 42 in the column 4 drives the positioning cylinder 5 and the bearing 51 to rotate 90 degrees to reset. The positioning cylinder 5 no longer obstructs the bar. Then, the tool holder 11 drives the cutting tool 12 to continue turning along the bar.

[0030] When clamping the fixed end of the round bar with chuck 13, the bar needs to be horizontally moved to adjust the clamping amount of chuck 13. If the round bar is relatively slender, the worker can only grasp the side of the round bar closest to the fixed end with both hands when observing and adjusting it near chuck 13. The starting end of the round bar is unsupported and tends to sag downwards, causing the round bar to tilt or bend, affecting the clamping accuracy of chuck 13 and subsequent turning. Therefore, before mounting the round bar on chuck 13, the worker first flips up the upper arc jaw 32 and hooks the head of the hook 323 into the slot 300 to fix the upper arc jaw 32. Figure 9 As shown, at this time, there is a large space between the two arc-shaped clamps 32, and the round bar can be placed between the positioning wheel 1 311 and the lower positioning wheel 2 321 for support. At the same time, the support rod 6 is placed horizontally below the round bar. By controlling the electric telescopic rod 62, the support rod 6 is pushed upward so that it contacts the bottom of the round bar. In conjunction with the positioning wheel 1 311 and the lower positioning wheel 2 321, the round bar is supported. Thus, one side of the starting end of the round bar is supported, which makes it convenient for the worker to move the round bar horizontally and adjust the clamping amount of the chuck 13 on the fixed end of the round bar. The starting end of the round bar does not sag or deform.

[0031] During turning, when the set speed of the round bar is high, the rolling friction between the positioning rollers 311 and 321 and the surface of the round bar can easily cause overheating. Furthermore, since the turning point of the cutting tool 12 is close to the positioning rollers 311 and 321, chips can easily splash onto the contact points between the positioning rollers 311 and 321 and the round bar, causing the positioning rollers 311 and 321 to crush the chips, affecting the accuracy of fixing the round bar. Therefore, before turning, coolant supply pipes are connected to connectors 312 and 322 respectively. During turning, coolant is continuously supplied to connectors 312 and 322. Coolant is supplied and sprayed from outlet 301 and outlet 302 onto the surface of the round bar, cooling the round bar, positioning wheel 311, and positioning wheel 321. At the same time, outlet 301 and outlet 302 are respectively located on both sides of positioning wheel 311 and positioning wheel 321. The sprayed coolant is continuously sprayed on both sides of positioning wheel 311 and positioning wheel 321, flushing away the turning chips from the contact point between positioning wheel 311 and positioning wheel 321 and the round bar, preventing positioning wheel 311 and positioning wheel 321 from crushing the chips and affecting the fixing accuracy of the round bar.

[0032] It should be noted that the control operations of all the above-mentioned parts are carried out through the intelligent control system integrated into the lathe 1.

[0033] Based on the above steps, we can see that the present invention has the following effects: Initially, the straight jaw 31 and the two curved jaws 32 support the round bar on the side away from the starting end, without hindering the cutting tool 12 from turning the end face of the round bar, and preventing the starting end of the round bar from swaying and affecting the turning. After turning the round bar for a certain distance, the positioning cylinder 5 temporarily supports the starting end of the round bar, and the two curved jaws 32 open to make room for the cutting tool 12 to change position. The cutting tool 12 changes position with the straight jaw 31 and the curved jaws 32, and the straight jaw 31 and the curved jaws 32 move closer to the starting end of the round bar, so as to reduce the sway generated at the starting end when the straight jaw 31 and the two curved jaws 32 move away from the starting end for support due to the turning movement, and thus avoid affecting the turning.

[0034] Although this disclosure has been shown and described with reference to specific exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made to this disclosure without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. Therefore, the scope of this disclosure should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents.

Claims

1. A positioning device for turning the end of a metal bar, comprising a lathe (1); a tool post (11) and a chuck (13) are mounted on the lathe (1); a cutting tool (12) is mounted on the tool post (11); characterized in that: It also includes a base plate (2), a mounting block (3), a column (4), a positioning cylinder (5), and an adjustment assembly; the base plate (2) is connected to the tool holder (11); the mounting block (3) is connected to the base plate (2); the base plate (2) is provided with an adjustment assembly for adjusting the position of the mounting block (3); a straight clamping jaw (31) is slidably connected to the mounting block (3); a tension spring (313) is connected between the straight clamping jaw (31) and the mounting block (3); a positioning wheel (311) is rotatably connected to the straight clamping jaw (31); two arc-shaped clamping jaws (32) are elastically rotatably connected to the mounting block (3) via torsion springs; each Each of the arc-shaped grippers (32) has a rotatable positioning wheel (321) at its end; the positioning wheel (311) and the two positioning wheels (321) are arranged in a triangular pattern; a transverse component (41) is installed on the base plate (2); a column (4) is fixedly connected to the moving end of the transverse component (41); a rotating ring (42) is rotatably connected to the column (4); a bearing (51) is connected to the rotating ring (42), and the outer ring of the bearing (51) is fixedly connected to the rotating ring (42); a positioning cylinder (5) for fixing the end of the bar is fixedly connected to the inner ring of the bearing (51); the positioning cylinder (5) is frustum-shaped, with the large circular surface facing the round bar.

2. A positioning device for end turning of a metal bar according to claim 1, characterized in that: The adjustment components include: a lateral translation block (21), a mounting plate (22), and a longitudinal translation block (23); at least two lateral translation blocks (21) are slidably connected to the base plate (2); all lateral translation blocks (21) are fixedly connected to the mounting plate (22); at least two longitudinal translation blocks (23) are slidably connected to the mounting plate (22); all longitudinal translation blocks (23) are connected to the mounting block (3).

3. A positioning device for end turning of a metal bar according to claim 2, characterized in that: It also includes a hook (323), a support rod (6), a connecting strip (61), and an electric telescopic rod (62); the hook (323) is rotatably connected to the upper arc clamp (32); the top of the mounting block (3) is provided with a slot (300) that matches the hook (323); the connecting strip (61) is fixedly connected to the swivel ring (42); the support rod (6) for supporting the rod is slidably connected to the connecting strip (61); the electric telescopic rod (62) is installed on the connecting strip (61); the telescopic end of the electric telescopic rod (62) is fixedly connected to the support rod (6).

4. A positioning device for end turning of a metal bar according to claim 2, characterized in that: It also includes connector one (312) and connector two (322); two liquid outlets one (301) are opened on the straight jaw (31); positioning wheel one (311) is located between the two liquid outlets one (301); connector one (312) is installed on the straight jaw (31), and connector one (312) is connected to liquid outlet one (301); two liquid outlets two (302) are opened on each arc jaw (32); positioning wheel two (321) is located between the two liquid outlets two (302); a connector two (322) is installed on each arc jaw (32), and connector two (322) is connected to liquid outlet two (302); connector one (312) and connector two (322) are both connected to external coolant supply pipes.

5. A positioning device for end turning of a metal bar according to any one of claims 1-4, characterized in that: It also includes baffles (24); two baffles (24) for blocking chips are fixed on the base plate (2); and the mounting block (3) is located between the two baffles (24).

6. A positioning device for end turning of a metal bar according to claim 1, characterized in that: The inner wall of the positioning cylinder (5) is covered with a wear-resistant rubber layer.

7. A positioning device for end turning of a metal bar according to claim 3, characterized in that: The telescopic ends of the support rod (6) and the electric telescopic rod (62) are rotatably connected, and rolling friction is formed between the support rod (6) and the round bar that is supported and translated.

8. A positioning device for end turning of a metal bar according to claim 7, characterized in that: The base plate (2) is provided with mounting holes for adjusting the installation position.

9. A positioning device for end turning of a metal bar according to claim 6, characterized in that: The swivel (42) and bearing (51) are detachable to allow for the replacement of positioning cylinders (5) of different diameters and lengths, thereby accommodating a wider range of bar sizes.

10. A positioning device for end turning of a metal bar according to claim 5, characterized in that: The side of the baffle (24) facing the rod is covered with absorbent felt.

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