Method and apparatus for precision machining of free cutting steel bar

Abstract

The application provides a precision machining method and equipment for a free-cutting steel rod, and relates to the technical field of steel rod machining, and comprises the following steps: S1, bidirectional extrusion of a rolled material from a first direction and a second direction of the side surface of the rolled material, removal of the oxide skin on the surface of the rolled material, and formation of extrusion marks on the surface of the rolled material; S2, continuous extrusion of the side surface of the rolled material by using a conical extrusion roller, and formation of a strip-shaped recessed area on the side surface of the rolled material. According to the application, the process of bidirectional extrusion of the rolled material from the first direction and the second direction of the side surface of the rolled material and continuous extrusion of the side surface of the rolled material by using the conical extrusion roller before the drawing forming process can well remove the oxide skin on the surface of the rolled material, avoid the influence of the oxide skin on the surface of the rolled material on the subsequent drawing forming size, and ensure the size and surface quality of the formed free-cutting steel rod.

Description

Technical Field

[0001] This invention relates to the field of steel bar processing technology, specifically to a precision machining method and equipment for free-cutting steel bars. Background Technology

[0002] Free-cutting steel bars are steels whose machinability is improved by adding specific elements (such as sulfur, lead, and calcium), and are widely used in the machining field. Their main characteristics include good machinability, high machining efficiency, and low tool wear. The chemical composition and properties of free-cutting steel bars vary depending on the added elements. For example, sulfur-based free-cutting steel improves machinability through sulfide inclusions, but may reduce transverse plasticity and toughness; while lead-based free-cutting steel reduces cutting forces through the lubricating effect of lead.

[0003] Currently, the processing technology for free-cutting steel bars involves first rolling them into rolled materials of a certain size (coarser than the finished product), and then processing them into finished products that meet the dimensional requirements through drawing (or cold drawing). However, due to the presence of oxide scale on the surface of the rolled material and its low plasticity and toughness, the traditional processing method for free-cutting steel bars easily leads to poor quality and unstable dimensions of the finished steel bars. Therefore, this invention provides a precision processing method and equipment for free-cutting steel bars. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a precision machining method and equipment for free-cutting steel bars, solving the problem that traditional machining methods for free-cutting steel bars easily lead to poor finished product quality and unstable dimensions.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A precision machining method for free-cutting steel bars includes the following steps:

[0007] S1. The rolled material is bidirectionally extruded from the first and second directions on the side of the rolled material to remove the oxide scale on the surface of the rolled material and to form extrusion marks on the surface of the rolled material.

[0008] S2. The side of the rolled material is continuously extruded using a conical extrusion roller to form a strip-shaped recessed area on the side of the rolled material. The formula for calculating the thickness h of the strip-shaped recessed area formed on the side of the rolled material is as follows:

[0009]

[0010] In formula ①, d represents the diameter of the free-cutting steel bar to be processed, and D represents the diameter of the rolled material;

[0011] S3. Free-cutting steel bars are formed using a one-time drawing process with a drawing die. The drawing die is provided with a guide portion corresponding to the strip-shaped recessed area formed on the side of the rolled material.

[0012] Steps S1, S2, and S3 all employ a drawing machine to drive the rolled material to move.

[0013] Preferably, in step S1, the first direction of the bidirectional extrusion of the rolled material from the side of the rolled material is perpendicular to the second direction.

[0014] A precision machining equipment for free-cutting steel bars includes a base, and a guide, a bidirectional extrusion assembly, a pre-extrusion assembly, and a drawing die are sequentially arranged on the top of the base along the moving direction of the rolled material.

[0015] The pre-extrusion assembly forms a strip-shaped recessed area on the side of the rolled material;

[0016] The drawing die is provided with a guide portion corresponding to the strip-shaped recessed area formed on the side of the rolled material.

[0017] Preferably, the guide includes: a fixed guide and an anti-sway guide, wherein the anti-sway guide is located between the fixed guide and the bidirectional extrusion assembly;

[0018] The anti-sway guide includes:

[0019] A ring-shaped component, wherein a horizontal plate is fixedly connected to the side of the ring-shaped component, and a guide hole is provided on the horizontal plate;

[0020] A stepped column has a thicker bottom section and a thinner top section. The thinner top section slides in conjunction with a guide hole. A spring is fitted on the thinner top section below the horizontal plate, and a clamping nut is threaded onto the thinner top section above the horizontal plate.

[0021] This invention provides a method and apparatus for precision machining of free-cutting steel bars. It offers the following advantages:

[0022] 1. This invention, by adding a process of bidirectional extrusion rolling from the side of the rolled material in a first and second direction before the drawing process, and continuously extruding the side of the rolled material using a conical extrusion roller, can effectively remove the oxide scale on the surface of the rolled material, avoiding the impact of the oxide scale on the subsequent drawing dimensions, and ensuring the size and surface quality of the formed free-cutting steel bar; moreover, by continuously extruding the side of the rolled material using a conical extrusion roller, a strip-shaped recessed area is formed on the side of the rolled material. A guide part corresponding to the strip-shaped recessed area formed on the side of the rolled material is provided in the drawing die. During the single drawing process of forming the free-cutting steel bar, the guide part is located inside the strip-shaped recessed area, which is used to restrict the circumferential rotation of the rolled material and avoid the appearance of wrinkles or overlapping parts on the side of the rolled material, which would affect the surface quality of the free-cutting steel bar.

[0023] 2. This invention designs a precision machining equipment for free-cutting steel bars, which includes a base. On the top of the base, along the direction of movement of the rolled material, are sequentially arranged a guide, a bidirectional extrusion assembly, a pre-extrusion assembly, and a drawing die. The guide is used to stabilize the rolled material. The bidirectional extrusion assembly is used to extrude and forge the rolled material in both the horizontal and vertical directions. The pre-extrusion assembly forms a strip-shaped recessed area on the side of the rolled material. The drawing die has a guide portion corresponding to the strip-shaped recessed area on the side of the rolled material. When the rolled material moves forward, the guide portion is located within the strip-shaped recessed area, thereby restricting the circumferential rotation of the rolled material and ensuring the surface quality and dimensional accuracy of the free-cutting steel bar during the drawing process. Attached Figure Description

[0024] Figure 1 This is a perspective view of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0025] Figure 2 This is a front view of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0026] Figure 3 This is a top view of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0027] Figure 4 This is a perspective view of a bidirectional extrusion assembly of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0028] Figure 5 This is a cross-sectional view of the bidirectional extrusion assembly of a precision machining equipment for free-cutting steel bars proposed in this invention.

[0029] Figure 6 This is a schematic diagram of the internal structure of the bidirectional extrusion assembly of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0030] Figure 7 This is a perspective view of the second-direction extrusion module of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0031] Figure 8 This is a first-view perspective perspective view of the pre-extrusion assembly of a precision machining equipment for free-cutting steel bars proposed in this invention;

[0032] Figure 9 This is a schematic diagram of the transmission principle within the pre-extrusion assembly of a precision machining equipment for free-cutting steel bars proposed in this invention.

[0033] Figure 10 This is a second-view perspective perspective view of the pre-extrusion assembly of a precision machining equipment for free-cutting steel bars proposed in this invention.

[0034] Among them, 1. Base; 2. Fixed guide component; 3. Anti-sway guide component; 301. Ring component; 302. Horizontal plate; 303. Stepped column; 304. Spring; 305. Compression nut; 4. Bidirectional extrusion assembly; 401. Square cylinder; 402. Support component; 403. First direction extrusion module; 404. Second direction extrusion module; 404a. Outer bracket; 404b. Arc-shaped frame; 404c. Guide component; 404d. Wedge block; 405. Bidirectional synchronous telescopic mechanism; 406. First connecting frame; 407. First sliding groove; 408. Second connecting frame; 409. Second sliding groove; 4010. Elastic element; 4011. External pressure plate; 5. Pre-extrusion assembly; 501. Ring seat; 501a. Central circular hole; 501b. Tapered hole; 502. Mounting ring seat; 503. Rotating shaft; 504. Tapered body; 505. Gear ring; 506. First gear; 507. Drive motor; 508. Second gear; 6. Drawing die; 7. Rolled material. Detailed Implementation

[0035] 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.

[0036] Example 1:

[0037] This invention provides a precision machining method for free-cutting steel bars, comprising the following steps:

[0038] S1. The rolled material is bidirectionally extruded from the first and second directions on the side of the rolled material to forge it, remove the oxide scale on the surface of the rolled material, and avoid the oxide scale on the surface of the rolled material from affecting the subsequent drawing and forming dimensions, so as to ensure the size and surface quality of the formed free-cutting steel bar. During the forging process, extrusion marks will be formed on the surface of the rolled material, which helps to leave lubricating oil at the extrusion marks on the surface of the rolled material during the drawing and forming process of free-cutting steel bar.

[0039] S2. The conical extrusion roller is used to continuously extrude the side of the rolled material to form a strip-shaped concave area on the side of the rolled material. The first purpose of this process is to better perform the one-time drawing forming process to form free-cutting steel bars; the second purpose is to deform the side of the rolled material so that some residual surface layer of the rolled material is prevented from falling off.

[0040] The formula for calculating the thickness h of the strip-shaped recessed region formed on the side of the rolled material is as follows:

[0041]

[0042] In formula ①, d represents the diameter of the free-cutting steel bar to be processed, and D represents the diameter of the rolled material. That is, it meets the requirements for forming the free-cutting steel bar in the subsequent one-time drawing process, and the thickness h of the strip-shaped recessed area formed on the side of the rolled material should not be too large.

[0043] S3. A free-cutting steel bar is formed using a drawing die in a single drawing process. The drawing die is provided with a guide portion corresponding to the strip-shaped recessed area formed on the side of the rolled material. During the single drawing process of forming the free-cutting steel bar, the guide portion is located inside the strip-shaped recessed area to restrict the circumferential rotation of the rolled material and avoid wrinkles or overlaps on the side of the rolled material, which would affect the surface quality of the free-cutting steel bar.

[0044] In steps S1, S2, and S3 above, a drawing machine is used to drive the rolled material to move. Specifically, a lathe is used to machine a stepped head at the head end of the rolled material to facilitate clamping and pulling. Then, the clamping part of the drawing machine is used to clamp the rolled material through the equipment that performs steps S1, S2, and S3 above, thereby driving the rolled material to move.

[0045] In one embodiment, in step S1, the rolling material is bidirectionally extruded from a first direction and a second direction on the side of the rolled material. The first direction and the second direction are perpendicular to each other, so that the side of the rolled material is better forged and continuous forging can be achieved as the rolled material moves.

[0046] Example 2:

[0047] like Figures 1-10 As shown, this embodiment of the invention provides a precision machining equipment for free-cutting steel bars, including a base 1, which is elongated and used to support linearly distributed equipment. A guide, a bidirectional extrusion assembly 4, a pre-extrusion assembly 5, and a drawing die 6 are sequentially arranged on the top of the base 1 along the moving direction of the rolled material 7. The guide is used to stabilize the rolled material 7. The bidirectional extrusion assembly 4 is used to extrude and forge the rolled material 7 in both the horizontal and vertical directions. The pre-extrusion assembly 5 forms a strip-shaped recessed area on the side of the rolled material. The drawing die 6 has a guide portion corresponding to the strip-shaped recessed area formed on the side of the rolled material. When the rolled material 7 moves forward, the guide portion is located within the strip-shaped recessed area, thereby restricting the circumferential rotation of the rolled material 7 and ensuring the surface quality and dimensional accuracy of the free-cutting steel bar during the drawing process.

[0048] In one embodiment, the guide includes a fixed guide 2 and an anti-sway guide 3, wherein the anti-sway guide 3 is located between the fixed guide 2 and the bidirectional extrusion assembly 4.

[0049] The rolled material 7 is initially guided by the fixed guide 2, and then guided a second time by the anti-sway guide 3 before entering the bidirectional extrusion assembly 4. The annular part 301 of the anti-sway guide 3 can swing up and down elastically to prevent the rolled material 7 from swinging too much when the bidirectional extrusion assembly 4 forges it, and also to provide the rolled material 7 with a certain amount of swing space.

[0050] The anti-sway guide component 3 includes: an annular component 301, a horizontal plate 302, a stepped column 303, a spring 304, and a clamping nut 305.

[0051] A horizontal plate 302 is fixedly connected to the side of the annular component 301. A guide hole is provided on the horizontal plate 302. The stepped column 303 has a thick bottom section and a thin top section. The stepped column 303 is fixedly installed on the base 1. There are two sets of stepped columns 303. The thick bottom section and the thin top section are an integral structure. A step is formed at the connection between the thick bottom section and the thin top section. The thin top section slides with the guide hole. A spring 304 is sleeved on the thin top section and below the horizontal plate 302. The bottom end of the spring 304 forms a step at the connection between the thick bottom section and the thin top section. A clamping nut 305 is threadedly connected on the thin top section and above the horizontal plate 302. During installation, the spring 304 is sleeved on the thin top section of the stepped column 303, and then the horizontal plate 302 is sleeved on (the thin top section is inserted into the guide hole on the horizontal plate 302). Finally, the clamping nut 305 is threadedly installed. At this time, the annular component 301 can be elastically compressed downward.

[0052] In one embodiment, the bidirectional extrusion assembly 4 includes: a square cylinder 401, a first-direction extrusion module 403, a second-direction extrusion module 404, and a wedge-type drive module.

[0053] The square cylinder 401 is fixedly installed on the base 1 by the support member 402 to ensure that the center height of the square cylinder 401 corresponds to the rolled material 7. The square cylinder 401 is provided with a first direction extrusion module 403 and a second direction extrusion module 404. The first direction extrusion module 403 and the second direction extrusion module 404 are distributed along the length direction of the rolled material 7 and are perpendicular to each other. The wedge-type drive module is used to drive the first direction extrusion module 403 and the second direction extrusion module 404 to extrude the rolled material 7 inward synchronously.

[0054] During use, the rolled material 7 moves forward along the center of the square cylinder 401. During the movement, the wedge-type drive module periodically moves, driving the first direction extrusion module 403 and the second direction extrusion module 404 to forge the side of the rolled material 7. This process is continuous and does not affect the subsequent drawing and forming. Since the first direction extrusion module 403 and the second direction extrusion module 404 are distributed along the length of the rolled material 7, every part of the rolled material 7 can be extruded by the first direction extrusion module 403 and the second direction extrusion module 404.

[0055] In one embodiment, the second-direction extrusion module 404 includes two sets of symmetrical extruders, which simultaneously extrude the rolled material 7 inward.

[0056] Specifically, the extrusion component includes: an outer bracket 404a, a wedge block 404d fixedly disposed on the outer side of the outer bracket 404a, and multiple parallel arc-shaped frames 404b fixedly connected to the inner side of the outer bracket 404a. Guide members 404c are fixedly installed on the outer side of the outer bracket 404a and on both sides of the wedge block 404d. The guide members 404c are slidably connected to the square cylinder 401. Under the guidance of the guide members 404c, the outer bracket 404a can be ensured to slide smoothly. Multiple parallel arc-shaped frames 404b are fixedly connected to the inner side of the outer bracket 404a. The multiple parallel arc-shaped frames 404b can extrude the rolled material 7 at multiple positions.

[0057] like Figure 6 As shown, the first direction extrusion module 403 and the second direction extrusion module 404 have the same structure, and the directions of the first direction extrusion module 403 and the second direction extrusion module 404 are perpendicular.

[0058] In one embodiment, an elastic element 4010 is fixedly connected to the outer side of the second directional extrusion module 404, and an external pressure plate 4011 is fixedly connected to the end of the guide 404c located on the outer side of the square cylinder 401. One end of the elastic element 4010 abuts against the inner side of the external pressure plate 4011. The elastic force generated by the elastic element 4010 pushes the external pressure plate 4011, thereby pushing the guide 404c to slide elastically outward. This structure design enables the first directional extrusion module 403 and the second directional extrusion module 404 to automatically return to their original position outward. After one extrusion forging, the extruded parts of the first directional extrusion module 403 and the second directional extrusion module 404 can automatically slide outward without affecting the movement of the rolled material 7.

[0059] In one embodiment, the wedge-type drive module includes: a bidirectional synchronous telescopic mechanism 405, a first connecting frame 406, a second connecting frame 408, a first sliding groove 407, and a second sliding groove 409.

[0060] A bidirectional synchronous telescopic mechanism 405 is fixedly connected to a square cylindrical body 401. Four bidirectional synchronous telescopic mechanisms 405 are provided, distributed at the four corners of the square cylindrical body 401. A first connecting frame 406 and a second connecting frame 408 are fixedly connected to both ends of each bidirectional synchronous telescopic mechanism 405. The bidirectional synchronous telescopic mechanism 405 drives the first connecting frame 406 and the second connecting frame 408 to move synchronously outward or inward. One end of a first sliding groove 407 is fixedly connected to the first connecting frame 406, causing the first sliding groove 407 to move with the first connecting frame 406. The outer side of the first sliding groove 407 slides in cooperation with the inner side of the second connecting frame 408, relying on the second connecting frame 408 to restrict the outward deformation of the first sliding groove 407. The inner side of the first sliding groove 407 cooperates with the wedge block of the outer bracket in the extrusion piece of the first directional extrusion module 403. When the blocks slide relative to each other, the inclined surface of the inner side of the first sliding groove 407 cooperates with the inclined surface of the wedge block of the outer bracket in the extrusion piece of the first direction extrusion module 403 to push the extrusion piece of the first direction extrusion module 403 inward, so that the extrusion piece of the first direction extrusion module 403 extrudes the rolled material 7 inward; one end of the second sliding groove 409 is fixedly connected to the second connecting frame 408, so that the second sliding groove 409 and the second connecting frame 408 move together, and the outer side of the second sliding groove 409... The first connecting frame 406 slides in conjunction with the inner side of the first connecting frame 406, which is used to restrict the outward deformation of the second sliding groove 409. The inner side of the second sliding groove 409 cooperates with the wedge block 404d of the outer bracket 404a in the extrusion piece of the second direction extrusion module 404. When the second sliding groove 409 slides relative to the wedge block 404d, it is used to push the outer bracket 404a and the arc frame 404b to slide inward, so that the extrusion piece of the second direction extrusion module 404 extrudes the rolled material 7 inward.

[0061] In one embodiment, the bidirectional synchronous telescopic mechanism 405 includes two sets of hydraulic telescopic rods. The tails of the two sets of hydraulic telescopic rods are arranged opposite each other, and the two sets of hydraulic telescopic rods are fixedly installed on the same L-shaped bracket. The two sets of hydraulic telescopic rods are controlled by a synchronous hydraulic valve so that the two sets of hydraulic telescopic rods extend and retract synchronously. This is reflected in the bidirectional synchronous telescopic mechanism 405 as a whole, where both ends of the bidirectional synchronous telescopic mechanism 405 extend or retract synchronously.

[0062] In one embodiment, the pre-extrusion assembly 5 includes: an annular seat 501, a mounting ring seat 502, a rotating shaft 503, a gear ring 505, and a drive motor 507.

[0063] The annular seat 501 is fixedly installed on the base 1. The annular seat 501 is a casting. A central circular hole 501a is opened in the center of the annular seat 501. Multiple conical holes 501b communicating with the central circular hole 501a are opened on the annular seat 501 outside the central circular hole 501a. Three sets of conical holes 501b are arranged in a circular array. The mounting ring seat 502 is fixedly connected to the end of the annular seat 501 facing the bidirectional extrusion assembly 4 by a short column. The number of rotating shafts 503 is the same as the number of conical holes 501b. The rotating shafts 503 are located in the conical holes 501b, and the mounting rings 502 are fixedly mounted on the rotating shafts 503. A tapered body 504 is mounted on the ring seat 502, and one end of the rotating shaft 503 is rotatably mounted on the ring seat 502. A first gear 506 is fixedly mounted on the other end of the rotating shaft 503. A gear ring 505 is rotatably mounted on the end of the ring seat 501 facing the drawing die 6, and the gear ring 505 meshes with the first gear 506. The rotation of the gear ring 505 synchronously drives the rotation of multiple first gears 506, that is, multiple rotating shafts 503 and multiple tapered holes 501b rotate synchronously. A drive motor 507 is fixedly mounted on the ring seat 501. A second gear 508 is fixedly mounted on the output shaft of the drive motor 507, and the second gear 508 meshes with the gear ring 505.

[0064] During operation, the drive motor 507 directly drives the second gear 508 to rotate. The second gear 508 meshes with the gear ring 505, thereby driving the gear ring 505 to rotate. The gear ring 505 meshes with multiple first gears 506, thereby driving multiple rotating shafts 503 and multiple tapered holes 501b corresponding to the multiple first gears 506 to rotate synchronously.

[0065] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for precision machining of free-cutting steel bars, characterized in that, Includes the following steps: S1. The rolled material is bidirectionally extruded from the first and second directions on the side of the rolled material to remove the oxide scale on the surface of the rolled material and to form extrusion marks on the surface of the rolled material. S2. Use a conical extrusion roller to continuously extrude the side of the rolled material to form a strip-shaped recessed area on the side of the rolled material; S3. Free-cutting steel bars are formed using a one-time drawing process with a drawing die. The drawing die is provided with a guide portion corresponding to the strip-shaped recessed area formed on the side of the rolled material. Steps S1, S2, and S3 all employ a drawing machine to drive the rolled material to move.

2. The precision machining method for a free-cutting steel bar according to claim 1, characterized in that: In step S1, the first direction of the bidirectional extrusion of the rolled material is perpendicular to the second direction.

3. A precision machining device for free-cutting steel bars, comprising a base (1), characterized in that: The base (1) is provided with a guide, a bidirectional extrusion assembly (4), a pre-extrusion assembly (5) and a drawing die (6) in sequence on the top of the base (1) and along the moving direction of the rolled material (7). The pre-extrusion assembly (5) forms a strip-shaped recessed area on the side of the rolled material; The drawing die (6) is provided with a guide portion corresponding to the strip-shaped recessed area formed on the side of the rolled material.

4. The precision machining equipment for free-cutting steel bars according to claim 3, characterized in that, The guide includes a fixed guide (2) and an anti-sway guide (3), wherein the anti-sway guide (3) is located between the fixed guide (2) and the bidirectional extrusion assembly (4).

5. The precision machining equipment for free-cutting steel bars according to claim 4, characterized in that, The anti-sway guide (3) includes: A ring-shaped component (301) has a horizontal plate (302) fixedly connected to its side, and a guide hole is provided on the horizontal plate (302). The stepped column (303) has a thick bottom section and a thin top section. The thin top section is slidably fitted with a guide hole. A spring (304) is sleeved on the thin top section and below the horizontal plate (302). A clamping nut (305) is threadedly connected on the thin top section and above the horizontal plate (302).

6. The precision machining equipment for free-cutting steel bars according to claim 3, characterized in that, The bidirectional extrusion assembly (4) includes: A square cylindrical body (401) is fixedly installed on the base (1) by a support member (402).

7. The precision machining equipment for free-cutting steel bars according to claim 6, characterized in that, The bidirectional extrusion assembly (4) includes: a first direction extrusion module (403) and a second direction extrusion module (404) are provided inside the square cylinder (401). The first direction extrusion module (403) and the second direction extrusion module (404) are distributed along the length direction of the rolled material (7). The first direction extrusion module (403) and the second direction extrusion module (404) are distributed perpendicularly. A wedge-type drive module is used to drive the first direction extrusion module (403) and the second direction extrusion module (404) to extrude the rolled material (7) inward synchronously.

8. The precision machining equipment for free-cutting steel bars according to claim 7, characterized in that, The wedge-type drive module includes: A bidirectional synchronous telescopic mechanism (405) is fixedly connected to a square cylinder (401), and a first connecting frame (406) and a second connecting frame (408) are fixedly connected to both ends of the bidirectional synchronous telescopic mechanism (405). The first sliding groove (407) has one end fixedly connected to the first connecting frame (406), the outer side of the first sliding groove (407) is slidably engaged with the inner side of the second connecting frame (408), and the inner side of the first sliding groove (407) is engaged with the wedge block of the outer bracket in the extrusion part of the first direction extrusion module (403).

9. The precision machining equipment for free-cutting steel bars according to claim 8, characterized in that: The second sliding groove (409) has one end fixedly connected to the second connecting frame (408), the outer side of the second sliding groove (409) is slidably engaged with the inner side of the first connecting frame (406), and the inner side of the second sliding groove (409) is engaged with the wedge (404d) of the outer bracket (404a) in the extrusion piece of the second direction extrusion module (404).

10. The precision machining equipment for free-cutting steel bars according to claim 8, characterized in that: The bidirectional synchronous telescopic mechanism (405) includes two sets of hydraulic telescopic rods, the tails of the two sets of hydraulic telescopic rods are arranged opposite each other, and the two sets of hydraulic telescopic rods are fixedly installed on the same L-shaped bracket.

Images