Pipe extrusion equipment and method

Abstract

The invention discloses pipe extrusion equipment and a pipe extrusion method. The pipe extrusion equipment comprises an extrusion cylinder; the extrusion needle assembly comprises an extrusion needle and a needle tip mounted at one end of the extrusion needle, and a plurality of limiting parts are arranged on the periphery of the extrusion needle; a mold assembly; a plurality of sliding grooves are formed in the periphery of the extrusion shaft, the limiting parts penetrate through the sliding grooves, the limiting parts can slide relative to the sliding grooves, and the number of the sliding grooves is not smaller than that of the limiting parts; the first end of the limiting rod is detachably installed at the end of the side, away from the die assembly, of the extrusion container, the second end of the limiting rod can abut against the limiting part on the extrusion needle, and when the limiting rod abuts against the limiting part, the needle tip is located at the target position of the die hole. According to the pipe extrusion equipment, damage to the extrusion needle assembly and related parts is effectively avoided, the reliability of the pipe extrusion equipment is improved, and the service life of the pipe extrusion equipment is prolonged; meanwhile, by means of detachable connection of the limiting rod and the extrusion cylinder, the stroke of the extrusion needle can be changed, and the application range is widened.

Description

Technical Field

[0001] The present invention relates to the field of pipe processing, and particularly to a pipe extrusion device and method. Background Art

[0002] For the production of seamless pipes by heavy extrusion presses with a capacity of over 5000 tons, fixed needle or follower needle extrusion methods are usually adopted, among which the fixed needle extrusion method is preferably used.

[0003] Currently, when using a fixed needle to extrude pipes on an extrusion press with an independent piercing system, excellent inner surfaces of the pipes, stable inner hole sizes of the pipes, and high production capacities can be obtained. However, due to the slippage of the metal relative to the extrusion needle during deformation and the large frictional force generated on the surface of the extrusion needle, each part of the piercing system will bear a strong tensile force during the extrusion process. When this tensile force exceeds the maximum load that the weak part of the piercing system can withstand, it will cause damage to the tools of the piercing system. Generally, the extrusion needle and the needle seat, and the needle seat and the connecting rod are connected by a threaded method. Since the cross-sectional area of the threaded connection part is significantly reduced and stress concentration is likely to occur at the threaded part, the overall maximum load-bearing capacity of the tool is significantly reduced. Under the action of the tensile force, fractures often occur at the threaded connection between the extrusion needle and the needle seat, and at the threaded connection between the needle seat and the connecting rod, resulting in tool accidents and significant economic losses.

[0004] In the prior art, to enhance the maximum load-bearing capacity of the piercing system, when designing and manufacturing the equipment, the size of the threaded part is increased as much as possible. However, for a single piece of equipment, due to space limitations, its threaded specification size is severely restricted, that is, its maximum load-bearing capacity is significantly limited. For example, when the diameter of the extrusion needle of an 8000-ton extrusion press reaches 300 mm, or when the extrusion needle of a 12500-ton extrusion press reaches 360, the tools of the piercing system are at a high risk of damage. When the diameter of the extrusion needle of a 12500-ton extrusion press reaches 420 mm and above, the risk of fracture during the production of high-strength alloy products is extremely high, and the fixed needle extrusion method is usually no longer selected. Therefore, when extruding pipes with the aforementioned large-diameter or larger-diameter extrusion needles, the follower needle extrusion method often has to be adopted. Moreover, the tool specifications on heavy extrusion presses are large, and each tool damage will cause losses ranging from tens of thousands to over one million. Therefore, in the metal extrusion industries such as aluminum and its alloys, magnesium and its alloys, it is difficult to avoid damage to the tools of the piercing system when using the fixed needle extrusion method to produce pipes with large-diameter and super-large-diameter extrusion needles.

[0005] In addition, the maximum load that the piercing system can bear is significantly related to the size of the thread specification. Since the piercing system is located on the center line of the extruder, restricted by space and the matching with tools such as the extrusion shaft, the size of the thread specification is also limited. This results in that the thread specification size cannot be increased arbitrarily to improve the maximum load-bearing capacity of the piercing system. Moreover, in the prior art, in order to avoid the excessive frictional tensile force acting on the tip and the extrusion needle during the extrusion process directly causing damage to the piercing system tools, measures such as using a processing technology to minimize the deformation resistance of the billet metal and using shorter billets are also adopted. However, due to the large billet specifications of heavy extruders, damage to the piercing system tools is still inevitable when producing large or extra-large sized pipes, which severely limits the pipe production capacity of the equipment.

[0006] Therefore, how to effectively improve the bearing capacity of pipe extrusion equipment and improve production efficiency is a technical problem that those skilled in the art need to solve currently. Summary of the Invention

[0007] The purpose of the present invention is to provide a pipe extrusion equipment and method for improving the production efficiency of pipes, reducing costs, reducing the tensile force borne by the extrusion needle, and improving the service life.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A pipe extrusion equipment, comprising:

[0010] An extrusion cylinder for accommodating a billet;

[0011] An extrusion needle assembly that can extend into or move out of the extrusion cylinder, with the billet sleeved around the periphery of the extrusion needle assembly; the extrusion needle assembly includes an extrusion needle and a tip installed at one end of the extrusion needle, and several limiting parts are provided on the periphery of the extrusion needle;

[0012] A die assembly installed at one end of the extrusion cylinder, the tip can be inserted into the die hole of the die assembly, and a gap for forming the billet is provided between the tip and the die hole;

[0013] An extrusion shaft sleeved around the outer periphery of the extrusion needle assembly for pushing the billet to move towards the die assembly. Moreover, several sliding grooves are provided on the periphery of the extrusion shaft, the limiting parts penetrate through the sliding grooves, and the limiting parts can slide relative to the sliding grooves, and the number of the sliding grooves is not less than the number of the limiting parts;

[0014] A limiting rod, wherein the first end of the limiting rod is detachably mounted on the end portion of the extrusion cylinder away from the mold assembly, and the second end of the limiting rod can abut against a limiting portion on the extrusion needle, and when the limiting rod abuts against the limiting portion, the needle tip is located at the target position of the mold hole.

[0015] Preferably, a plurality of positioning holes are provided at the end of the extrusion cylinder, and the limiting rod is detachably installed in the positioning holes, and the number of the positioning holes is not less than the number of the limiting parts.

[0016] Preferably, the side of the limit block close to the needle tip and the second end face of the limit rod are both planes, the plane of the limit block can fit with the end face of the limit rod, and the diameter of the second end face of the limit rod is larger than the plane width of the limit block.

[0017] Preferably, the limiting portion is block-shaped or plate-shaped, and the extension direction of the limiting portion is parallel to the axial direction of the extrusion needle; and / or the limiting portion is a right-angled trapezoid, and the right-angled side of the limiting portion is arranged close to the needle tip.

[0018] Preferably, it also includes an annular extrusion pad, which is located between the extrusion shaft and the ingot, and the extrusion shaft can push the ingot to move through the extrusion pad; and the inner diameter of the extrusion pad is 0.2-2mm larger than the outer diameter of the extrusion needle and 0.2-2.0mm smaller than the inner diameter of the extrusion barrel.

[0019] Preferably, the extrusion needle assembly also includes a needle seat and a connecting rod, the needle seat is located between the connecting rod and the extrusion needle, and the connecting rod and the needle seat, the needle seat and the extrusion needle, and the extrusion needle and the needle tip are all connected by internal threads and screws.

[0020] Preferably, the extrusion shaft is also provided with an axial hole, a front section and a rear section, the front section can enter the extrusion cylinder, and the axial hole is arranged on the axis of the extrusion shaft; the rear section is truncated cone-shaped, and the end with a smaller diameter is connected to the front section, the slide groove is opened on the front section, and each slide groove is arranged in parallel.

[0021] Preferably, the extrusion needle includes a front needle section, a rear needle section, a needle screw and a needle internal thread, the needle screw and the needle internal thread are respectively located at both ends of the extrusion needle, the needle tip is connected to the front needle section, and the diameter of the rear needle section is larger than the diameter of the front needle section, and the limiting portion is arranged on the rear needle section near the front needle section.

[0022] Preferably, the limiting portion and the extrusion needle are an integrally formed structure, and the limiting portions are evenly distributed along the circumference of the extrusion needle; the number of the sliding grooves and the limiting portions is the same and corresponds one to one.

[0023] A method for extruding a pipe, using the above-mentioned pipe extrusion equipment, comprising the following steps:

[0024] Place a cylindrical billet into the extrusion cylinder, and abut a die sleeve equipped with a die and a die pad against one end of the extrusion cylinder;

[0025] Control the extrusion needle to enter the extrusion cylinder and pass through the billet;

[0026] Select a limiting rod with a preset length and install it on the extrusion cylinder, insert the tip of the needle into the target position of the die hole of the die, and make the limiting part of the extrusion needle abut against the limiting rod;

[0027] Control the extrusion shaft to enter the extrusion cylinder and push the billet to start extrusion. The metal of the billet passes through the gap between the die hole and the tip of the needle to obtain a pipe product.

[0028] The tube extrusion equipment provided by the present invention comprises: an extrusion barrel for accommodating an ingot; an extrusion needle assembly, which can be inserted into or removed from the extrusion barrel, and the ingot is sleeved on the periphery of the extrusion needle assembly; the extrusion needle assembly comprises an extrusion needle and a needle tip installed at one end of the extrusion needle, and the periphery of the extrusion needle is provided with a plurality of limit parts; a mold assembly, which is installed at one end of the extrusion barrel, and the needle tip can be inserted into the mold hole of the mold assembly, and a gap for molding the ingot is provided between the needle tip and the mold hole; an extrusion shaft, which is sleeved on the extrusion needle The outer periphery of the assembly is used to push the ingot to move toward the direction of the mold assembly, and a plurality of slide grooves are provided on the periphery of the extrusion shaft, the limiting portion passes through the slide groove, and the limiting portion can slide relative to the slide groove, and the number of the slide grooves is not less than the number of the limiting portions; a limiting rod, the first end of which is detachably mounted on the end portion of the extrusion cylinder away from the mold assembly, the second end of the limiting rod can abut against the limiting portion on the extrusion needle, and when the limiting rod abuts against the limiting portion, the needle tip is located at the target position of the mold hole. The tube extrusion equipment provided by the present invention, by arranging the limiting part on the periphery of the extrusion needle, and with the cooperation of the slide groove, when the extrusion shaft is pushed to move, the metal of the ingot will cover the needle tip and the extrusion needle, and when the metal of the ingot flows forward, it will generate a forward friction pulling force on the needle tip and the extrusion needle, and the friction pulling force will partially or completely act on the limiting part, thereby effectively reducing the stress state of the structure at the rear end of the limiting part in the extrusion needle assembly, avoiding damage to the extrusion needle assembly and related components, and improving the reliability and service life of the tube extrusion equipment; at the same time, by arranging the limiting rod and utilizing the detachable connection between the limiting rod and the extrusion barrel, when it is necessary to adjust the target position of the needle tip in the die hole, it is only necessary to remove the limiting rod and replace it with a limiting rod of other lengths, and then install it again, which can change the stroke of the extrusion needle and improve the scope of application.

[0029] The tube extrusion method provided by the present invention uses the tube extrusion equipment as described above, and includes the following steps: placing a cylindrical billet into the extrusion cylinder, and abutting a die sleeve equipped with a die and a die pad against one end of the extrusion cylinder; controlling the extrusion needle to enter the extrusion cylinder and pass through the billet; selecting a limiting rod with a preset length and installing it on the extrusion cylinder, inserting the tip of the needle into the target position of the die hole of the die, and making the limiting part of the extrusion needle abut against the limiting rod; controlling the extrusion shaft to enter the extrusion cylinder and pushing the billet to start extrusion, and the metal of the billet passes through the gap between the die hole and the tip of the needle to obtain a tube product. The tube extrusion method provided by the present invention adjusts the stress state of the extrusion needle by changing the structure of the extrusion needle, and applies the tensile force borne by the extrusion needle to the extrusion cylinder. Since the bearing capacity of the extrusion cylinder is much higher than that of the extrusion needle assembly, the extrusion needle assembly and the related components in the piercing system no longer form a through tensile force, but use the extrusion cylinder as a carrier to bear the tensile force formed on the extrusion needle when the metal of the billet deforms, thus fundamentally changing the stress state of the piercing system and avoiding damage to the key tools in the piercing system, such as the extrusion needle, the needle base or the connecting rod, etc.; at the same time, by replacing the limiting rod with a preset length, the adjustment of the tip of the needle extending into the target position of the die hole of the die can be realized, so as to realize the adjustment of the stroke of the extrusion needle, and the applicable range is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 is an exploded view of a specific embodiment of the tube extrusion equipment provided by the present invention;

[0032] Figure 2 is Figure 1 a cross-sectional view of the assembled tube extrusion equipment as shown;

[0033] Figure 3 is Figure 1 a structural schematic diagram of the extrusion shaft in the tube extrusion equipment as shown;

[0034] Figure 4 is Figure 1 a structural schematic diagram of the extrusion needle in the tube extrusion equipment as shown;

[0035] Figure 5 is Figure 1Schematic structural diagram of the extrusion cylinder in the shown pipe extrusion equipment;

[0036] Figure 6 Flow chart of the pipe extrusion method provided by the present invention;

[0037] Wherein: 1 needle base, 2 extrusion shaft, 21 shaft hole, 22 rear section of the shaft, 23 front section of the shaft, 24 sliding groove, 3 extrusion needle, 31 needle screw, 32 load-bearing limit part, 33 front section of the needle, 34 internal thread, 35 rear section of the needle, 4 needle tip, 5 extrusion pad, 6 ingot blank, 7 extrusion cylinder, 71 positioning hole, 72 ingot holding hole, 8 die sleeve, 9 die, 10 die pad, 11 limit rod. Specific embodiments

[0038] The core of the present invention is to provide a pipe extrusion equipment and method, which can effectively improve the bearing capacity of the pipe extrusion equipment, reduce costs, and improve the pipe production efficiency.

[0039] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] The pipe extrusion equipment and method provided by the present invention, on the premise of ensuring the fixed needle extrusion effect, significantly reduce or eliminate the pulling force transmitted from the ingot blank 6 to the thread of the extrusion needle assembly, so as to avoid damage to the components in the piercing system, significantly exert the equipment capacity, improve the pipe production efficiency, and reduce costs. Specifically, by providing a load-bearing limit part 32 on the extrusion needle 3, and correspondingly providing a sliding groove 24 on the extrusion shaft 2; the limit part 32 on the extrusion needle 3 can slide in the sliding groove 24 to avoid interference with the extrusion shaft 2. The frictional pulling force acting on the needle tip 4 and the extrusion needle 3 during the extrusion process is mostly borne by the limit part 32, and no through-type pulling force in the axial direction of the extrusion needle assembly is formed on the piercing system, so that the force on the threaded connection of the piercing system is significantly reduced or not stressed; since the size of the limit part 32 is less restricted by space, its maximum load-bearing capacity can be adjusted as needed, and the selectable size range is significantly increased.

[0041] Since the present invention significantly reduces or does not load the pulling force at the key connection points such as the thread between the extrusion needle 3 and the needle base 1 in the piercing system, and the thread between the needle base 1 and the connecting rod, etc., the maximum load that the piercing system can bear as a whole is more than 3 times that of the original piercing system. In actual production, there is almost no phenomenon of unexpected damage to the piercing system tools.

[0042] The present invention is provided with a limit rod 11, which is used to limit the extrusion needle 3. The limit rod 11 is used in conjunction with the positioning hole 71 on the extrusion cylinder 7. The length of the limit rod 11 can be arbitrarily selected, thereby adjusting the stroke of the extrusion needle 3, so that the length of the needle tip 4 at the front end of the extrusion needle 3 extending into the die hole can be selected, that is, the target position of the needle tip 4 can be selected to meet the process requirements. By providing the limit rod 11, the present invention avoids the limitation that the stroke cannot be adjusted due to the use of the load-bearing claw structure of the extrusion needle 3, that is, the limit part 32 structure.

[0043] Please refer to Figures 1 to 6 , Figure 1 An exploded view of a specific embodiment of the tube extrusion equipment provided by the present invention; Figure 2 for Figure 1 A cross-sectional view of the tube extrusion apparatus shown after assembly; Figure 3 for Figure 1 A schematic diagram of the structure of the extrusion shaft 2 in the pipe extrusion equipment shown; Figure 4 for Figure 1 A schematic diagram of the structure of the extrusion needle 3 in the tube extrusion device shown; Figure 5 for Figure 1 The schematic diagram of the structure of the extrusion cylinder in the pipe extrusion equipment shown; Figure 6 The present invention is a flow chart of the tube extrusion method provided by the present invention.

[0044] In this embodiment, the tube extrusion apparatus comprises:

[0045] An extrusion barrel 7, used for accommodating the ingot 6;

[0046] The extrusion needle assembly can be inserted into the extrusion barrel 7 or removed from the extrusion barrel 7. The ingot 6 is sleeved on the periphery of the extrusion needle assembly. The extrusion needle assembly includes an extrusion needle 3 and a needle tip 4 installed at one end of the extrusion needle 3. The periphery of the extrusion needle 3 is provided with a plurality of stoppers 32.

[0047] The die assembly is mounted at one end of the extrusion barrel 7, and the needle tip 4 can be inserted into the die hole of the die assembly. A gap is provided between the needle tip 4 and the die hole for forming the ingot 6;

[0048] The extrusion shaft 2 is sleeved on the outer periphery of the extrusion needle assembly and is used to push the ingot 6 to move toward the mold assembly. In addition, a plurality of slide grooves 24 are provided on the periphery of the extrusion shaft 2. The limiting portion 32 passes through the slide grooves 24 and can slide relative to the slide grooves 24. The number of the slide grooves 24 is not less than the number of the limiting portions 32.

[0049] The limiting rod 11, the first end of the limiting rod 11 is detachably mounted on the end of the extrusion cylinder 7 away from the mold assembly, the second end of the limiting rod 11 can abut against the limiting portion 32 on the extrusion needle 3, and when the limiting rod 11 abuts against the limiting portion 32, the needle tip 4 is located at the target position of the mold hole.

[0050] It should be noted here that the length of the limit rod 11 needs to be determined according to the processing requirements. When the limit part 32 abuts against the end face of the limit rod 11, the tip 4 of the needle should just move to the target position, that is, the gap size between the tip 4 of the needle and the die hole is exactly the size of the pipe to be processed; specifically, multiple groups of limit rods 11 with different preset lengths can be set. When replacement is needed, just replace different groups of limit rods 11.

[0051] Furthermore, it also includes an extrusion shaft 2 seat. The extrusion shaft 2 is installed on the extrusion shaft 2 seat, and the extrusion shaft 2 is pushed by the extrusion shaft 2 seat to move, completing the extrusion forming of the ingot blank 6; for reasons that are easily understood by professionals, the extrusion shaft 2 seat referred to in the present invention is not illustrated in the drawings.

[0052] For the convenience of assembly, the chute 24 of the extrusion shaft 2 is open at the end of the extrusion shaft 2. Thus, when the extrusion shaft 2 is installed into the extrusion cylinder 7, the limit part 32 of the extrusion needle 3 can slide into the chute 24 from the end of the chute 24 of the extrusion shaft 2, facilitating assembly.

[0053] The hole in the middle of the extrusion cylinder 7 is used to hold the ingot blank 6, and the ingot blank 6 deforms within the extrusion cylinder 7; the ingot blank 6 is a deformable metal, such as aluminum and its alloys, magnesium and its alloys, etc.; the ingot blank 6 is in a cylindrical shape, with an outer diameter smaller than the inner diameter of the extrusion cylinder 7, and the inner diameter of the ingot blank 6 is larger than the diameter of the extrusion needle 3. The length of the ingot blank 6 is shorter than the length of the extrusion cylinder 7, and the specific length is not limited; the heated ingot blank 6 is placed in the ingot holding hole 72 of the extrusion cylinder 7.

[0054] Specifically, the extrusion needle assembly belongs to a part of the piercing system. The piercing system is used to control the extrusion needle assembly to enter the extrusion cylinder 7 and, during the extrusion process, fix the extrusion needle assembly to prevent the extrusion needle assembly from moving; the production process of seamless pipes with an independent piercing system is as follows: the extrusion needle 3 is assembled with the needle seat 1 by threaded connection, and the tip 4 of the needle is installed at the front end of the extrusion needle 3; the tip 4 plays a role in sizing the inner diameter of the pipe and determines the inner diameter size of the pipe; the ingot blank 6 is placed in the round hole of the extrusion cylinder 7; the die 9 is placed at one end of the extrusion cylinder 7 and contacts the ingot blank 6; the extrusion pad 5 is placed into the extrusion cylinder 7; the extrusion pad 5 and the die 9 are respectively located at both ends of the ingot blank 6; the extrusion needle 3 equipped with the tip 4 of the needle passes through the hole of the extrusion pad 5 and the hole of the ingot blank 6, so that the front working part of the tip 4 extends into the hole of the die hole and remains limited, ensuring that the extrusion needle 3 will not move beyond the expected range during the extrusion process; the extrusion shaft 2 pushes the extrusion pad 5 to extrude the ingot blank 6, and the ingot blank 6 undergoes plastic deformation under high temperature and high pressure, and the metal flows out from the gap between the die hole and the tip 4 of the needle, forming the required product; during the extrusion process, the metal of the ingot blank 6 will coat the tip 4 and the extrusion needle 3, and when the metal flows forward, it will generate a forward frictional pulling force on the tip 4 and the extrusion needle 3.

[0055] The path for the tool of the piercing system in the present invention not to break is as follows:

[0056] When the metal of the ingot blank 6 deforms, frictional tensile forces are generated on the tip 4 and the extrusion needle 3. The extrusion needle 3 is pulled forward, and the limiting portion 32 on the extrusion needle 3 presses against the end face of the limiting rod 11. The limiting rod 11 bears the pressure of the limiting rod 11 and transmits the force to the extrusion cylinder 7, and the extrusion cylinder 7 forms a support for the limiting rod 11. The force exerted by the limiting rod 11 on the limiting portion 32 is approximately equal to the frictional tensile forces generated on the tip 4 and the extrusion needle 3 when the metal of the ingot blank 6 deforms, and the directions of the two forces are opposite. At this time, the section of the extrusion needle 3 from the limiting portion 32 to the needle base 1 does not bear tensile force, including the external thread at the connection between the needle base 1 and the extrusion needle 3 and the dangerous section at the internal thread 34. These dangerous sections are no longer prone to breakage.

[0057] The tube extrusion equipment provided by the present invention, by arranging the limiting portion 32 on the periphery of the extrusion needle 3 and in cooperation with the sliding groove 24, when the extrusion shaft 2 is pushed to move, the metal of the ingot blank 6 will cover the tip 4 and the extrusion needle 3. When the metal of the ingot blank 6 flows forward, a forward frictional tensile force will be generated on the tip 4 and the extrusion needle 3, and this frictional tensile force will act partially or entirely on the limiting portion 32, thereby effectively reducing the stress state of the structure at the rear end of the limiting portion 32 in the extrusion needle assembly, avoiding damage to the extrusion needle assembly and related components, and improving the reliability and service life of the tube extrusion equipment.

[0058] In some embodiments, a plurality of positioning holes 71 are provided at the end of the extrusion cylinder 7, and the limiting rod 11 is detachably installed in the positioning holes 71, and the number of the positioning holes 71 is not less than the number of the limiting portions 32. Specifically, the extrusion cylinder 7 is provided with positioning holes 71 and an ingot holding hole 72. The ingot holding hole 72 is located at the center of the extrusion cylinder 7 and is used for holding the ingot blank 6, and the ingot blank 6 deforms in the ingot holding hole 72 of the extrusion cylinder 7; the diameter of the ingot holding hole 72 is larger than the outer diameter of the ingot blank 6 and also larger than the outer diameter of the extrusion pad 5; the positioning holes 71 are used to cooperate with the limiting rod 11; the diameter of the positioning holes 71 is slightly larger than the diameter of the limiting rod 11, and the depth of the positioning holes 71 is not limited, as long as it is convenient for the installation and disassembly of the limiting rod 11 and the limiting rod 11 is not easy to fall off, and the specific dimensions are not limited.

[0059] In some embodiments, the side of the limiting block close to the tip 4 and the end face of the second end of the limiting rod 11 are both flat surfaces, and the flat surface of the limiting block can be attached to the end face of the limiting rod 11. Specifically, by providing flat surfaces on the limiting block and the limiting rod 11, the stability when the limiting portion 32 abuts against the end face of the limiting rod 11 can be ensured, so that the tensile force borne by the extrusion needle 3 can be better transmitted to the extrusion cylinder 7, and at the same time, the influence of the limiting block on the end face of the extrusion cylinder 7 is avoided and reduced. Of course, under the condition of operation, the side of the limiting block close to the tip 4 can also be a concave-convex surface or an arc surface.

[0060] Preferably, the diameter of the second end face of the limiting rod 11 is larger than the plane width of the limiting block. Further, the limiting rod 11 is preferably a movable solid cylindrical metal part, which bears the force and transmits the pressure to the extrusion cylinder 7; the diameter of the limiting rod 11 is smaller than the diameter of the positioning hole 71 of the extrusion cylinder 7, and larger than the thickness of the limiting portion 32 of the extrusion needle 3, to ensure that the limiting portion 32 can accurately abut against the limiting rod 11. The number of limiting rods 11 in use is the same as the number of limiting portions 32, for example, it can be 3. The limiting rods 11 are used in groups, that is, each time they are used, the specifications of each limiting rod 11 are the same; when the stroke of the perforation system is to be adjusted, that is, the length of the needle tip 4 extending into the mold hole is adjusted, that is, the target position of the needle tip 4 is adjusted, then the limiting rod 11 of another length can be replaced, and at the same time, it is also ensured that the lengths of the replaced limiting rods 11 are the same.

[0061] In some embodiments, the limiting portion 32 is block-shaped or plate-shaped, and the extension direction of the limiting portion 32 is parallel to the axial direction of the extrusion needle 3. Specifically, when the limiting portion 32 is block-shaped, the connection part between the limiting portion 32 and the extrusion needle 3 has a larger area and higher strength; the limiting portion 32 is preferably plate-shaped, and the plane where the limiting portion 32 is located is parallel to the axial direction of the extrusion needle 3, that is, the connection part between the limiting portion 32 and the extrusion needle 3 is strip-shaped, and the strip-shaped connection part is parallel to the axial direction of the extrusion needle 3. This is set to reduce the width of the slide 24, which can not only ensure the strength of the limiting portion 32, but also reduce the influence of the slide 24 on the strength of the extrusion shaft 2. That is, under the premise of ensuring that the limiting portion 32 and the slide 24 are matched, the width of the slide 24 should be as small as possible to reduce the influence on the extrusion shaft 2.

[0062] In some embodiments, the limiting portion 32 is in a right-angled trapezoid, and the right-angled side of the limiting portion 32 is arranged close to the needle tip 4. Specifically, in the right-angled trapezoid structure, on the one hand, the right-angled side of the limiting portion 32, that is, the side of the limiting portion 32 close to the needle tip 4 is a plane, which is fitted and abutted with the limiting rod 11; on the other hand, the hypotenuse of the limiting portion 32, that is, the side of the limiting portion 32 away from the needle tip 4 is an inclined surface, which can increase the area of ​​the connection structure between the limiting portion 32 and the extrusion needle 3, thereby improving the stability of the limiting portion 32. Furthermore, the limiting portion 32 is preferably a right-angled trapezoidal plate-like structure, which is convenient for cooperation with the slide groove 24 and reduces the impact on the width of the slide groove 24.

[0063] In some embodiments, it further includes an annular extrusion pad 5. The extrusion pad 5 is located between the extrusion shaft 2 and the billet 6, and the extrusion shaft 2 can push the billet 6 to move through the extrusion pad 5. Specifically, one end of the billet 6 contacts the extrusion pad 5, and the other end contacts the die 9; the extrusion cylinder 7, the extrusion needle 3, the extrusion pad 5, the die sleeve 8, the die 9, and the tip 4 form an incompletely enclosed space, and the billet 6 is placed in this incompletely enclosed space. There is only a gap between the tip 4 and the die 9 in this incompletely enclosed space, and this gap is for the metal of the billet 6 to flow out from it to form a pipe. During operation, the extrusion pad 5 moves towards the die 9 under the push of the extrusion shaft 2 to form extrusion on the billet 6. The metal of the billet 6 undergoes plastic deformation under high temperature and high pressure and flows out from the gap between the tip 4 and the die 9, forming an extruded pipe product whose outer shape is similar to the cavity size of the die 9 and whose inner cavity shape is similar to the cross-sectional shape of the tip 4. Preferably, the extrusion pad 5 is a perforated round cake. When in use, it is located between the billet 6 and the extrusion shaft 2, and its function is to seal the metal of the billet 6 to prevent the metal of the billet 6 from overflowing towards the extrusion shaft 2.

[0064] Preferably, the outer diameter of the extrusion pad 5 is 0.2 - 2.0 mm smaller than the inner diameter of the extrusion cylinder 7, and the inner diameter of the extrusion pad 5 is 0.2 - 2.0 mm larger than the diameter of the extrusion needle 3. The thickness of the extrusion pad 5 is not limited. That is to say, between the extrusion pad 5 and the extrusion cylinder 7 and the extrusion needle 3, as long as the gap that can meet the relative movement is satisfied, it should be reduced as much as possible to avoid the metal of the billet 6 from overflowing.

[0065] In some embodiments, the extrusion needle assembly further includes a needle base 1 and a connecting rod. The needle base 1 is located between the connecting rod and the extrusion needle 3. Between the connecting rod and the needle base 1, between the needle base 1 and the extrusion needle 3, and between the extrusion needle 3 and the tip 4, internal threads 34 and screws are used for connection, and the screw is provided with external threads. Specifically, the tip 4 is used to determine the diameter of the inner diameter of the pipe, and it determines the size of the pipe cavity; the cross-section of the working part of the tip 4 can be circular or non-circular; a screw is provided on the tip 4, and the external thread of the screw is connected to the internal thread 34 of the extrusion needle 3. Similarly, a screw is provided on the needle base 1, and the external thread of the screw is connected to the internal thread 34 of the connecting rod. Further, the needle base 1 is used to connect the extrusion needle 3 and the connecting rod. For reasons that are easily understood by professionals, the connecting rod referred to in the present invention is not shown in the accompanying drawings of the specification; an internal thread 34 is provided at one end of the needle base 1 close to the extrusion needle 3, and this internal thread 34 and the external thread on the needle screw 31 of the extrusion needle 3 form a thread pair. An external thread is provided at one end of the needle base 1 close to the connecting rod, and this external thread and the internal thread 34 of the connecting rod form a thread pair.

[0066] In some embodiments, the die assembly includes a die sleeve 8, a die 9 and a die pad 10 that can be installed inside the die sleeve 8. The die hole is located in the middle of the die 9. Specifically, the die 9 is used for metal forming. It is provided with a cavity, and the cavity is provided with a working belt. The working belt sizes the outer diameter of the pipe and determines the outer dimension of the pipe. The die pad 10 is used to support the die 9 to enhance the rigidity of the die 9. The cavity of the die pad 10 is a through hole, and the cross section of the through hole is similar and larger than the cross section of the outlet of the cavity of the die 9. The die sleeve 8 is used to assemble the die 9 and the die pad 10 to restrict the radial positions of the die 9 and the die pad 10. The die sleeve 8 is located at one end of the ingot 6.

[0067] In some embodiments, the extrusion shaft 2 is further provided with a shaft hole 21, a front shaft section 23 and a rear shaft section 22. The front shaft section 23 can enter the extrusion cylinder 7, and the shaft hole 21 is disposed through the axis of the extrusion shaft 2. The rear shaft section 22 is frustum-shaped, and the end with the smaller diameter is connected to the front shaft section 23. The sliding grooves 24 are formed on the front shaft section 23, and the sliding grooves 24 are arranged in parallel. Specifically, the extrusion shaft 2 is provided with a shaft hole 21, a rear shaft section 22, a front shaft section 23 and sliding grooves 24. The shaft hole 21 of the extrusion shaft 2 is a central through hole along the axis. The diameter of the shaft hole 21 is larger than the maximum diameter of the front needle section 33 of the extrusion needle 3 and also larger than the maximum diameter of the section of the needle holder 1 that needs to enter the shaft hole 21 to ensure the passability of the needle holder 1 and the extrusion needle 3 in the shaft hole 21. The maximum outer diameter of the rear shaft section 22 is larger than the outer diameter of the front shaft section 23. The rear shaft section 22 cooperates with other tools and has an assembly function. The front shaft section 23 of the extrusion shaft 2 has a constant cross section or a non-constant cross section, preferably a constant cross section. The sliding grooves 24 are axially formed on the front shaft section 23. The sliding grooves 24 penetrate from the shaft center to the outside along the radial direction of the extrusion shaft 2 and extend axially to the end face of the front shaft section 23 and penetrate the end face of the front shaft section 23. No sliding grooves 24 are provided at the rear shaft section 22 to ensure the strength and stability of the rear shaft section 22. The width of the sliding groove 24 is larger than the thickness of the limiting portion 32 of the extrusion needle 3. The number of the sliding grooves 24 is the same as the number of the limiting portions 32 of the extrusion shaft 2.

[0068] In some embodiments, the extrusion needle 3 includes a front needle section 33, a rear needle section 35, a needle screw 31, and an internal needle thread 34. The needle screw 31 and the internal needle thread 34 are respectively located at both ends of the extrusion needle 3. The needle tip 4 is connected to the front needle section 33. Moreover, the diameter of the rear needle section 35 is larger than that of the front needle section 33, and the limiting portion 32 is provided at a position on the rear needle section 35 close to the front needle section 33. Specifically, the diameter of the rear needle section 35 of the extrusion needle 3 is larger than that of the front needle section 33, and the diameter of the rear needle section 35 of the extrusion needle 3 is smaller than the diameter of the shaft hole 21 of the extrusion shaft 2. The two are in a matching relationship. By setting the diameter of the rear needle section 35 of the extrusion needle 3 to be larger than that of the front needle section 33, on the one hand, the gap between the extrusion shaft 2 and the rear needle section 35 of the extrusion needle 3 is smaller, which can ensure the connection stability between the extrusion shaft 2 and the rear needle section 35 of the extrusion needle 3. Moreover, it can reduce the influence of the limiting portion 32 on the extrusion needle 3 when bearing pressure and reduce the shaking of the extrusion needle 3. Additionally, the diameter of the front needle section 33 of the extrusion needle 3 is relatively smaller than that of the rear needle section 35, which is convenient for the cooperation between the front needle section 33 and the ingot billet 6 and the extrusion pad 5; the rear needle section 35 plays a guiding role to make the axis of the piercing system coincide with the axis of the extrusion shaft 2 as much as possible.

[0069] In some embodiments, the limiting portion 32 and the extrusion needle 3 are of an integrally formed structure, and the limiting portions 32 are evenly distributed along the circumference of the extrusion needle 3; the number of the sliding grooves 24 is the same as that of the limiting portions 32 and they correspond one by one. Specifically, the extrusion needle 3 is provided with an internal needle thread 34, a front needle section 33, a limiting portion 32, and a needle screw 31. The limiting portions 32 are distributed on the circumference of the extrusion needle 3 and extend radially outward of the extrusion needle 3 to form a claw structure; the limiting portion 32 of the extrusion needle 3 cooperates with the sliding groove 24 of the extrusion shaft 2, and the limiting portion 32 can slide in the sliding groove 24. During extrusion, the limiting portion 32 of the extrusion needle 3 abuts against the end face of the extrusion cylinder 7, and the frictional pulling force generated during the metal deformation of the ingot billet 6 can act on the limiting rod 11 partially or entirely through the limiting portion 32 and be transmitted to the extrusion cylinder 7 via the limiting rod 11. The number of the limiting portions 32 of the extrusion needle 3 can be set to 2 - 8, preferably 2 - 4. The shape of the limiting portion 32 of the extrusion needle 3 is not limited and can be rectangular, triangular, etc. The thickness of the limiting portion 32 is not limited. The needle screw 31 of the extrusion needle 3 cooperates with the internal thread 34 of the needle base 1 to form a screw pair. The front needle section 33 of the extrusion needle 3 is the working section, and its diameter is smaller than the inner diameters of the extrusion pad 5 and the ingot billet 6, and is 0.2 - 2 mm smaller than the inner diameter of the extrusion pad 5.

[0070] The tube extrusion equipment fundamentally changes the stress state of the piercing system by transmitting the frictional tensile force acting on the extrusion needle 3 to the end face of the extrusion cylinder 7 through the limiting part 32 on the extrusion needle 3; the extrusion cylinder 7 can bear a large force, so the design of the limiting part 32 and the limiting rod 11 is flexible, and the magnitude of the force it can bear can be determined according to needs; it can significantly improve the maximum load-bearing capacity of the piercing system and significantly improve and break through the limit of the tube production capacity of the original equipment design; by using the positioning hole 71 and the limiting rod 11 in the extrusion cylinder 7, the problem of stroke adjustment of the piercing system in tube production is solved.

[0071] In addition to the above tube extrusion equipment, the present invention also provides a tube extrusion method.

[0072] The tube extrusion method includes the following steps:

[0073] Step S1: Place the cylindrical billet 6 into the extrusion cylinder 7, and make the die sleeve 8 equipped with the die 9 and the die pad 10 abut against one end of the extrusion cylinder 7;

[0074] Step S2: Control the extrusion needle 3 to enter the extrusion cylinder 7 and pass through the billet 6;

[0075] Step S3: Select a limiting rod 11 with a preset length and install it on the extrusion cylinder 7, insert the tip 4 of the needle into the target position of the die hole of the die 9, and make the limiting part 32 of the extrusion needle 3 abut against the limiting rod 11;

[0076] Step S4: Control the extrusion shaft 2 to enter the extrusion cylinder 7 and push the billet 6 to start extrusion. The metal of the billet 6 passes through the gap between the die hole and the tip 4 of the needle to obtain a tube product.

[0077] In some embodiments, before the step of controlling the extrusion needle 3 to enter the extrusion cylinder 7, it further includes the step of:

[0078] Load the extrusion pad 5 into the extrusion cylinder 7 from the other end of the extrusion cylinder 7;

[0079] The step of controlling the extrusion needle 3 to enter the extrusion cylinder 7 and pass through the billet 6 further includes: controlling the extrusion needle 3 to enter the extrusion cylinder 7 and pass through the extrusion pad 5 and the billet 6.

[0080] The method for the present invention to achieve an adjustable stroke of the piercing system is:

[0081] By replacing the limiting rods 11 with different length groups, the displacement of the extrusion needle 3 is restricted, so as to achieve the purpose of adjustable stroke.

[0082] In a specific embodiment, the tube extrusion method includes the following steps:

[0083] Connect and assemble the needle base 1 and the connecting rod and fix them;

[0084] Assemble and fix the extrusion shaft 2 to the extrusion shaft 2 seat;

[0085] Insert the needle seat 1 into the extrusion shaft 2 through the shaft hole 21 at the rear shaft section 22 of the extrusion shaft 2 as far as possible;

[0086] Insert the threaded rod 31 end of the extrusion needle 3 into the extrusion shaft 2 through the shaft hole 21 at the front shaft section 23 of the extrusion shaft 2, and keep the limiting part 32 outside the sliding groove 24. Screw the extrusion needle 3 to assemble and fix it to the needle seat 1;

[0087] Operate the rotating mechanism of the piercing system to adjust the position of the limiting part 32 so that the limiting part 32 is aligned with the sliding groove 24 of the extrusion shaft 2, and ensure that the limiting part 32 can slide freely in the sliding groove 24. It should be noted that when the limiting part 32 of the extrusion needle 3 is outside the sliding groove 24 of the extrusion shaft 2 and the extrusion needle 3 cannot be screwed and fastened, the limiting part 32 of the extrusion needle 3 should enter the sliding groove 24 of the extrusion shaft 2, and keep the extrusion shaft 2 and the extrusion shaft 2 seat loose. At the same time, screw the extrusion shaft 2 and the extrusion needle 3. After ensuring that the extrusion needle 3 and the needle seat 1 are screwed firmly, assemble and fix the extrusion shaft 2 to the extrusion shaft 2 seat;

[0088] Screw and fix the needle tip 4 on the extrusion needle 3; The threaded rod 31 on the needle tip 4 and the internal thread 34 of the extrusion needle 3 form a thread pair;

[0089] Push the extrusion shaft 2 to start the forming process, keep the limiting part 32 abutted against the limiting rod 11 until the forming is completed, and take out the extrusion needle assembly.

[0090] The pipe extrusion equipment and method provided by the present invention have the following advantages:

[0091] 1. The extrusion needle 3 of the present invention is provided with a limiting part 32, and the frictional tensile force acting on the extrusion needle 3 during the extrusion process is transmitted to the extrusion cylinder 7 through the limiting part 32, thereby reducing or eliminating the tensile force at the external thread of the threaded rod 31 of the extrusion needle 3, the internal thread 34 of the needle seat 1, and the external thread of the needle seat 1, and avoiding the damage of the extrusion needle 3 and the needle seat 1.

[0092] 2. The extrusion shaft 2 of the present invention is provided with a sliding groove 24, and the limiting part 32 of the extrusion needle 3 can slide in the sliding groove 24, thereby avoiding the interference between the extrusion needle 3 and the extrusion shaft 2.

[0093] 3. The extrusion cylinder 7 of the present invention is provided with a positioning hole 71 for placing the limiting rod 11.

[0094] 4. The pipe extrusion equipment of the present invention is provided with a limiting rod 11 for adjusting the stroke position of the piercing system.

[0095] 5. The implementation of the present invention can completely solve the risk of fracture of the extrusion needle 3 and the needle seat 1 of the heavy extrusion machine, and can significantly improve the ultimate pipe production capacity of the equipment.

[0096] 6. While solving the problem of the risk of the extrusion needle 3 breaking, the present invention solves the problem of stroke adjustment of the piercing system.

[0097] 7. By adopting the tools related to the piercing system of the present invention and the pipe production process, the fixed-needle extrusion method for producing pipes is realized, which can significantly improve the maximum load-bearing capacity of the piercing system and significantly improve and break through the limit of the pipe production capacity of the original equipment design.

[0098] In the pipe extrusion method provided by the present invention, by changing the structure of the extrusion needle 3, the stress state of the extrusion needle 3 is adjusted, and the tensile force borne by the extrusion needle 3 acts on the extrusion cylinder 7. Since the load-bearing capacity of the extrusion cylinder 7 is much higher than that of the extrusion needle assembly, the relevant components in the extrusion needle assembly and the piercing system no longer form a through-type tensile force, but use the extrusion cylinder 7 as the carrier to bear the tensile force formed on the extrusion needle 3 during the metal deformation of the ingot blank 6, thereby fundamentally changing the stress state of the piercing system and avoiding the damage of key tools in the piercing system, such as the extrusion needle 3, the needle base 1, or the connecting rod.

[0099] The above has introduced in detail the pipe extrusion equipment and method provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A pipe extrusion device, It is characterized in that include: An extrusion cylinder (7) for accommodating the ingot (6); An extrusion needle assembly can be inserted into or removed from the extrusion barrel (7), and the ingot (6) is sleeved on the periphery of the extrusion needle assembly; the extrusion needle assembly comprises an extrusion needle (3) and a needle tip (4) mounted on one end of the extrusion needle (3), and a plurality of stoppers (32) are provided on the periphery of the extrusion needle (3); A die assembly is mounted on one end of the extrusion barrel (7), the needle tip (4) can be inserted into a die hole of the die assembly, and a gap is provided between the needle tip (4) and the die hole for forming the ingot (6); An extrusion shaft (2) is sleeved on the outer periphery of the extrusion needle assembly and is used to push the ingot (6) to move in the direction of the mold assembly, and a plurality of slide grooves (24) are provided on the periphery of the extrusion shaft (2), the limiting portion (32) passes through the slide grooves (24), and the limiting portion (32) can slide relative to the slide grooves (24), and the number of the slide grooves (24) is not less than the number of the limiting portions (32); A limiting rod (11), wherein the first end of the limiting rod (11) is detachably mounted on an end portion of the extrusion cylinder (7) which is away from the mold assembly, and the second end of the limiting rod (11) can abut against a limiting portion (32) on the extrusion needle (3), and when the limiting rod (11) abuts against the limiting portion (32), the needle tip (4) is located at a target position of the mold hole.

2. The tube extrusion equipment according to claim 1, It is characterized in that The end of the extrusion cylinder (7) is provided with a plurality of positioning holes (71), and the limiting rod (11) is detachably mounted in the positioning holes (71), and the number of the positioning holes (71) is not less than the number of the limiting portions (32).

3. The tube extrusion equipment according to claim 1, It is characterized in that The side of the limit block close to the needle tip (4) and the second end face of the limit rod (11) are both planes, the plane of the limit block can fit with the end face of the limit rod (11), and the diameter of the second end face of the limit rod (11) is greater than the plane width of the limit block.

4. The tube extrusion device according to claim 3, It is characterized in that The limiting portion (32) is block-shaped or plate-shaped, and the extending direction of the limiting portion (32) is parallel to the axial direction of the extrusion needle (3); and / or the limiting portion (32) is a right-angled trapezoid, and the right-angled side of the limiting portion (32) is arranged close to the needle tip (4).

5. The tube extrusion equipment according to claim 1, It is characterized in that It also includes an annular extrusion pad (5), which is located between the extrusion shaft (2) and the billet (6), and the extrusion shaft (2) can push the billet (6) to move through the extrusion pad (5); and the inner diameter of the extrusion pad (5) is 0.2-2 mm larger than the outer diameter of the extrusion needle (3) and 0.2-2.0 mm smaller than the inner diameter of the extrusion cylinder (7).

6. The tube extrusion equipment according to claim 1, It is characterized in that The extrusion needle assembly further comprises a needle seat (1) and a connecting rod, wherein the needle seat (1) is located between the connecting rod and the extrusion needle (3), and the connecting rod and the needle seat (1), the needle seat (1) and the extrusion needle (3), and the extrusion needle (3) and the needle tip (4) are all connected by internal threads (34) and screws.

7. The tube extrusion device according to any one of claims 1 to 6, It is characterized in that The extrusion shaft (2) is also provided with an axial hole (21), a shaft front section (23) and a shaft rear section (22); the shaft front section (23) can enter the extrusion cylinder (7); the axial hole (21) is arranged on the axis of the extrusion shaft (2); the shaft rear section (22) is truncated cone-shaped, and the end with a smaller diameter is connected to the shaft front section (23); the slide groove (24) is opened on the shaft front section (23), and each of the slide grooves (24) is arranged in parallel.

8. The tube extrusion device according to any one of claims 1 to 6, It is characterized in that The extrusion needle (3) comprises a needle front section (33), a needle rear section (35), a needle screw (31) and a needle internal thread (34); the needle screw (31) and the needle internal thread (34) are respectively located at two ends of the extrusion needle (3); the needle tip (4) is connected to the needle front section (33); the diameter of the needle rear section (35) is larger than the diameter of the needle front section (33); and the limiting portion (32) is arranged on the needle rear section (35) at a position close to the needle front section (33).

9. The tube extrusion device according to claim 8, It is characterized in that The limiting portion (32) and the extrusion needle (3) are an integrally formed structure, and the limiting portions (32) are evenly distributed along the circumference of the extrusion needle (3); the number of the sliding grooves (24) and the limiting portions (32) is the same and corresponds one to one.

10. A pipe extrusion method, using the pipe extrusion device according to any one of claims 1 to 9, It is characterized in that The following steps are involved: Putting a cylindrical ingot (6) into an extrusion cylinder (7), and placing a die sleeve (8) equipped with a die (9) and a die cushion (10) against one end of the extrusion cylinder (7); Controlling the extrusion needle (3) to enter the extrusion barrel (7) and pass through the ingot (6); A limiting rod (11) having a preset length is selected and installed on the extrusion cylinder (7), the needle tip (4) is extended to a target position of a die hole of the die (9), and the limiting portion (32) of the extrusion needle (3) is abutted against the limiting rod (11); The extrusion shaft (2) is controlled to enter the extrusion cylinder (7) and push the billet (6) to start extrusion. The metal of the billet (6) passes through the gap between the die hole and the needle tip (4) to obtain a tube product.

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