A pipe drawing device for threaded pipe

Abstract

The present invention discloses a tube drawing device for a threaded tube, comprising a first chuck, a second chuck, several groups of roller assemblies and a fixing member. The circumferential outer walls of the rollers of the several groups of roller assemblies enclose a cavity connected to a first through hole; when the front end of the fixing member away from the second chuck slides into the cavity with the second chuck, a rolling area at a starting position is formed between the fixing member and the rollers. Since the tube drawing device does not provide a liner core and a core head to support the inner wall of the tube, no defects such as friction marks or scratches will be formed on the inner wall of the tube during the tube drawing process; when the roller rolls the thread at the starting position of the tube, since the front end of the fixing member extends into the cavity to support the inner wall of the tube at the starting position of rolling the thread, when the roller rolls the tube at the starting position of forming the thread, the phenomenon of the inner diameter of the tube being instantly reduced is avoided; so that the inner diameter size of the pulled threaded tube at different positions is uniform.

Description

Technical Field

[0001] The invention relates to the technical field of threaded pipe processing, and in particular to a pipe drawing device for a threaded pipe. Background Art

[0002] At present, threaded pipes are mostly used in the refrigeration industry. For example, threaded pipes are used in heat exchangers, and heat exchangers are then used in industrial places such as water heaters, air conditioners, refrigerators, chillers / oil chillers, etc. With the diversification of the market, threaded pipes are gradually used in food-grade water purifiers.

[0003] Most existing threaded pipes are pulled out by core pulling pipes, such as Figure 1 As shown, the core tube drawing device includes a left chuck a1, a right chuck a2, a chuck a3 installed on the left chuck, a bushing installed in the inner hole of the right chuck and a bushing core a4 with one end fixed in the bushing and the other end extending out of the bushing, and a core head a5 with one end fixed in the bushing and the other end extending out of the bushing; a plurality of rollers are arranged evenly around the outer circumference of the core head on the left end face of the right chuck, and a rolling area is formed between the plurality of rollers and the core head, and the rollers are used as tools to roll threads on the outer wall surface of the tube. The left chuck can slide toward or away from the right chuck under the drive of the driving mechanism; the right chuck and the rollers are driven by the rotating spindle on the machine tool to make circular motion.

[0004] When pulling a tube, the tube drawing device of this structure first places the tube in the inner hole of the bushing and the inner hole of the right chuck. The left end of the tube extends out of the bushing and is successively sleeved on the bushing core and the core head and extends outward, and finally sleeved on the chuck. The core head and the bushing core both support the inner wall of the tube. When the driving mechanism drives the left chuck and the chuck to drive the tube to move away from the right chuck, the right chuck rotates at the same time to roll the roller to roll the outer wall of the tube supported on the outer wall of the core head, thereby forming a thread on the outer wall of the tube, completing the threaded tube pulling process.

[0005] However, in this tube drawing device, since rolling pressure is always generated between the core head and the roller during the tube drawing process, and the core head is supported on the inner wall of the tube, the core head is easily subjected to the rolling pressure of the roller, which may cause defects such as friction marks or scratches on the inner wall of the tube, thus affecting the quality of the threaded tube. For example, when the threaded tube is used to transport drinking water, drinking water is prone to breed bacteria at the friction marks on the inner wall of the threaded tube, which may affect human health. If the above-mentioned liner and core head are not provided, although no marks are formed on the inner wall of the threaded tube, the roller may easily exert an instantaneous rolling pressure on the tube when initially rolling the tube, and the inner diameter of the tube may be instantly reduced by rolling, which may affect the uniformity of the inner diameter size at different positions of the pulled threaded tube. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is that when the existing tube drawing device is provided with a liner core and a core head, marks will appear on the inner wall surface of the pulled threaded tube, affecting the quality of the threaded tube; if the liner core and the core head are not provided, the uniformity of the inner diameter size of the pulled threaded tube at different positions will be poor.

[0007] To this end, the present invention provides a threaded tube drawing device, comprising a first chuck and a second chuck relative to each other; the second chuck is slidably arranged on a machine tool in a direction close to or away from the first chuck; the first chuck is rotatably arranged on the machine tool and is provided with a first through hole extending in a sliding direction of the second chuck;

[0008] A plurality of roller assemblies are arranged on the first chuck and extend out of the end of the first chuck facing the second chuck and are evenly located on the outer periphery of the first through hole along the circumference of the first through hole; any of the roller assemblies has a rotatable roller, and the circumferential outer walls of the rollers of the plurality of roller assemblies form a cavity connected to the first through hole;

[0009] A fixing member is coaxially mounted on the second chuck with the first through hole, and a front end of the fixing member away from the second chuck forms a rolling area at a starting position between the fixing member and the roller when the front end of the fixing member slides into the cavity as the second chuck slides.

[0010] Optionally, in the above-mentioned threaded tube pulling device, the fixing part includes a mounting column installed on the second chuck and a support column fixed on the mounting column, the radial diameter of the support column is smaller than the radial diameter of the mounting column, and a rolling area of ​​the starting position is formed between the support column and the roller.

[0011] Optionally, in the above-mentioned threaded tube pulling device, the inner cavity of the support column is a hollow structure.

[0012] Optionally, the above-mentioned threaded pipe drawing device further includes a first bushing coaxially arranged in the first through hole, and the inner hole of the first bushing is used for installing the pipe to be drawn.

[0013] Optionally, the above-mentioned threaded tube drawing device also includes a balance tube and at least one support frame arranged outside the machine tool, one end of the balance tube extends into the first through hole and is coaxially fixed on the first bushing away from the inner end of the second chuck, and the other end extends out of the first through hole and is installed on the support frame; the inner hole of the first bushing and the inner hole of the balance tube are jointly provided for the installation of the pipe to be drawn.

[0014] Optionally, in the above-mentioned threaded tube pulling device, an annular step that is radially recessed inward is provided on the hole wall of the inner end of the first bushing, so that the inner hole of the first bushing is a stepped hole, and the end of the balance tube is installed on the annular step.

[0015] Optionally, in the above-mentioned threaded tube drawing device, the end of the first chuck away from the second chuck is coaxially mounted on the hollow rotating spindle of the machine tool;

[0016] The other end of the balance pipe passes through the first chuck and the inner holes of the hollow rotating spindle in sequence and extends out of the machine tool.

[0017] Optionally, in the above-mentioned threaded tube pulling device, an outer edge protruding radially outward is provided on the end of the first bushing close to the outer end of the second chuck, and the outer edge abuts against the end face of the end of the first chuck.

[0018] Optionally, in the above-mentioned threaded tube pulling device, the second chuck is provided with a second through hole coaxial with the first through hole; the tube pulling device also includes a tail chuck coaxially arranged in the second through hole, and the inner end of the fixing member away from the first chuck is inserted into the inner hole of the tail chuck.

[0019] Optionally, in the above-mentioned threaded tube drawing device, the second chuck is slidably disposed on the machine tool via a sliding mechanism;

[0020] The sliding mechanism includes a guide rail extending along the sliding direction of the second chuck, a slider slidably arranged on the guide rail, an end of the second chuck facing away from the first chuck fixed to the slider, and a driving component driving the slider to slide on the guide rail.

[0021] The technical solution of the present invention has the following advantages:

[0022] 1. The threaded tube drawing device provided by the present invention comprises a first chuck and a second chuck relative to each other; a plurality of roller assemblies and a fixing member. The second chuck is slidably arranged on a machine tool in a direction close to or away from the first chuck; the first chuck is rotatably arranged on the machine tool and a first through hole extending in the sliding direction of the second chuck is arranged on the first chuck; a plurality of roller assemblies are arranged on the first chuck and extend out of the end of the first chuck facing the second chuck and are evenly located on the outer periphery of the first through hole along the circumference of the first through hole; any of the roller assemblies has a rotatable roller, and the circumferential outer walls of the rollers of the plurality of roller assemblies form a cavity connected to the first through hole; the fixing member is coaxially mounted on the second chuck with the first through hole, and a rolling area at a starting position is formed between the front end of the fixing member away from the second chuck and extends into the cavity as the second chuck slides.

[0023] In the tube drawing device of this structure, since the liner core and core head of the tube drawing device in the background technology are not arranged in the first through hole of the first chuck to support the inner wall of the tube, defects such as friction marks or scratches will not be formed on the inner wall of the tube during the tube drawing process; at the same time, when the roller rolls the thread at the starting position of the tube, since the front end of the fixing piece extends into the cavity surrounded by multiple rollers, the front end of the fixing piece supports the inner wall of the tube at the starting position of the thread rolling, thereby avoiding the phenomenon of the inner diameter of the tube being instantly reduced when the roller rolls the starting position of the thread forming the tube; the inner diameter size of the pulled threaded tube at different positions is made uniform, thereby improving the quality of the pulled threaded tube, and further allowing the threaded tube to be used in the water purifier industry, ensuring that human health is not affected when drinking the water transported in the threaded tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the partial structure of the tube drawing device in the prior art;

[0026] Figure 2 It is a structural schematic diagram of a tube drawing device provided in an embodiment of the present invention;

[0027] Figure 3 for Figure 2 A longitudinal cross-sectional schematic diagram of an enlarged local structure of the intermediate tube drawing device;

[0028] Figure 4 for Figure 2 An enlarged schematic diagram of the local structure of the sliding mechanism of the middle tube drawing device;

[0029] Figure 5 for Figure 2 A schematic diagram of the coordination of the first chuck, the second chuck, the fixing member and the roller assembly of the intermediate tube drawing device;

[0030] Figure 6 for Figure 5 An exploded schematic diagram of the first chuck, the second chuck, the fixing member, and the roller assembly;

[0031] Figure 7 for Figure 3 A partial enlarged schematic diagram of the first chuck, the first bushing and the balance tube in the middle tube drawing device;

[0032] Figure 8 for Figure 5 A schematic diagram of the structure of the first chuck, the roller assembly and the first bushing;

[0033] Fig. 9 for Figure 5 A schematic diagram of the structure of the second chuck, the fixing member and the tail chuck;

[0034] Description of reference numerals:

[0035] 1-first chuck; 11-first through hole;

[0036] 2-second chuck; 21-second through hole;

[0037] 3-Machine tools;

[0038] 4-roller assembly; 41-roller; 42-intermediate shaft; 43-claw;

[0039] 5-fixing part; 51-installation column; 52-support column;

[0040] 6 - first bushing; 61 - outer edge; 62 - annular step;

[0041] 71 - balance pipe; 72 - support frame;

[0042] 8-tail clip;

[0043] 9 – hollow rotating spindle;

[0044] 101 - guide rail; 102 - slider; 1031 - driver; 1032 - gear; 1033 - rack. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Example 1

[0050] This embodiment provides a threaded tube drawing device, such as Figures 2 to 9 As shown, it includes a machine tool 3, a first chuck 1, a second chuck 2, a first bushing 6, a fixing member 5 and several groups of roller assemblies 4.

[0051] like Figure 2 and Figure 3 As shown, the first chuck 1 and the second chuck 2 are arranged on the machine tool 3 relatively, and the second chuck 2 is slidably arranged on the machine tool 3 in a direction close to or away from the first chuck 1; the first chuck 1 is rotatably arranged on the machine tool 3, and a first through hole 11 extending along the sliding direction of the second chuck 2 is arranged in the middle of the first chuck 1. For example, the sliding direction of the second chuck 2 is Figure 2 The left and right direction in .

[0052] A plurality of roller assemblies 4 are arranged on the end surface of the first chuck 1 facing the second chuck 2 (such as Figure 3 The rollers 41 are arranged on the left end of the first chuck 1 in the drawing and are evenly located on the outer periphery of the first through hole 11. Any roller assembly 4 has a rotatable roller 41. The circumferential outer wall surfaces of the rollers 41 of several groups of roller assemblies 4 form a cavity and are connected to the first through hole. The rollers 41 are used as tools to generate rolling pressure on the outer wall surface of the pipe to be drawn so as to form threads on the outer wall surface of the pipe.

[0053] For example, in this embodiment, four groups of roller assemblies 4 are provided, and the circumferential outer wall surfaces of the four rollers 41 form a cavity. The structure of each group of roller assemblies 4 is the same, and the specific structure of one group of roller assemblies 4 is now described. Figure 6 and Figure 7As shown, the roller assembly 4 includes the above-mentioned roller 41, the intermediate shaft 42 and the claw 43. The two claws 43 are relatively fixed and form a through hole for the intermediate shaft 42 to pass through. The claw 43 is fixed on the end face of the first chuck 1. The bottom of the intermediate shaft 42 is locked on the end of the claw 43 by a locking member, such as a locking nut or a limit pin. The roller 41 is rotatably arranged on the end of the intermediate shaft 42 to achieve self-rotation; when the first chuck 1 rotates, the four groups of roller assemblies 4 are driven to rotate, and then the four rollers 41 are made to revolve with the first chuck, and the rotating rollers 41 apply rolling pressure to the outer wall of the pipe to be pulled through the cavity. In other words, the roller 41 itself rotates on the intermediate shaft 42 and revolves with the first chuck 1. When the roller 41 rotates, rolling contact is formed between the roller 41 and the outer wall of the pipe, so as to buffer the rolling stress of the roller 41 on the outer wall of the pipe.

[0054] like Figure 3 , Figure 5 , Figure 6 and Figure 8 As shown, the first bushing 6 is coaxially arranged in the first through hole 11, and the inner hole of the first bushing 6 is used for the installation of the pipe to be drawn. The first bushing 6 does not have a bushing core and a core head as in the background art. To facilitate the installation of the first bushing 6, the end of the first bushing 6 close to the outer end of the second chuck 2 (for example Figure 7 The left end of the first chuck 1 is provided with an outer edge 61 protruding radially outward, and the outer edge 61 abuts against the end surface of the end of the first chuck 1, so as to facilitate the installation and positioning of the first bushing 6. The first bushing can be installed in the first through hole in a variety of fixing ways, such as threaded fit or plug-in fit.

[0055] like Figure 5 , Figure 7 and Fig. 9 As shown, the fixing member 5 is coaxially mounted with the first through hole 11 on the end of the second chuck 2 facing the first chuck 1 (for example Fig. 9 The left end of the first chuck 1 in the middle), the front end of the fixing member 5 away from the second chuck 2 (for example Figure 7 The right end of the fixing member 5 in the middle is suitable for extending into or extending out of the cavity surrounded by the plurality of rollers 41 when sliding with the second chuck 2, and the front end of the fixing member 5 forms a rolling area of ​​the starting position between the rollers 41 when extending into the cavity.

[0056] When the tube drawing device is required to draw a tube, the first chuck 1 moves toward the direction close to the second chuck 2 (for example, Figure 5The second chuck moves to the right), so that the front end of the fixing member 5 extends into the cavity and forms a rolling area at the starting position relative to the roller 41; the pipe to be drawn is installed in the inner hole of the first bushing 6, and one end of the pipe extends out of the first bushing 6 and is sleeved on the fixing member 5; at this time, the rotation of the first chuck 1 drives all the roller assemblies 4 to rotate, and the front end of the fixing member 5 supports the inner wall surface of the pipe sleeved thereon, and the roller 41 just rolls the outer wall surface of the pipe sleeved by the front end of the fixing member 5, and the outer wall surface just serves as the starting position for the pipe to form a thread; while the roller 41 rotates, the second chuck 2 drives the pipe to move in the direction away from the first chuck 1 (for example Figure 5 The second chuck 2 moves to the left in the middle), so that the tube is rolled by the rotating roller 41 during the movement, so that the outer wall of the tube is formed with a thread. Due to the supporting effect of the front end of the fixing member, the inner diameter of the tube can be prevented from being instantly reduced when the tube is instantly rolled by the roller 41 at the starting position; as the second chuck 2 continues to move away from the first chuck 1, the front end of the fixing member 5 will be pulled out of the cavity surrounded by the multiple rollers 41. At this time, the front end of the fixing member 5 no longer supports the inner wall of the tube in the cavity surrounded by the rollers 41. If no other supporting structure is provided on the inner wall of the pipe, when the roller 41 rolls the outer wall of the pipe, no friction marks or scratches will be formed on the inner wall of the pipe, thereby ensuring the inner diameter size of the thread formed at the starting position of the pipe, so that the inner diameter size of the pulled threaded pipe at different positions is uniform, and at the same time, in the process of forming the thread on the outer wall of other positions of the pipe, there are no friction marks and scratches on the inner wall of the pipe, thereby improving the quality of the threaded pipe, and then the threaded pipe can be used in the water purifier industry, ensuring that the human body will not be affected when drinking the water transported in the threaded pipe.

[0057] As for the structure of the fixing member 5, Figure 3 , Figure 5 and Fig. 9 As shown, the fixing member 5 includes a mounting column 51 mounted on the second chuck 2 and a support column 52 fixed on the mounting column 51. The radial diameter of the support column 52 is smaller than the radial diameter of the mounting column 51. A rolling area at a starting position is formed between the support column 52 and the roller 41. At this time, a step surface is formed between the support column 52 and the mounting column 51. When one end of the pipe to be pulled is sleeved on the mounting column, a certain gap is formed between the pipe outside the support column 52 and the outer wall surface of the support column 52. When the roller 41 rolls the pipe outside the support column 52, especially the step surface has a buffering effect, which will not affect the firmness of the pipe sleeved on the mounting column.

[0058] More preferably, the inner cavity of the support column 52 is a hollow structure. When the roller 41 rolls the pipe outside the support column 52, the hollow structure of the support column 52 can release the rolling force of the roller 41 on the support column 52 in the hollow inner cavity, thereby preventing the rolling force from acting on the inner wall of the pipe and forming friction marks or scratches on the inner wall of the pipe.

[0059] like Figure 6 and Fig. 9 As shown, the middle of the second chuck 2 is provided with a second through hole 21 coaxial with the first through hole 11; the tube pulling device also includes a tail chuck 8 coaxially arranged in the second through hole 21, and the inner end of the mounting column 51 in the fixing member 5 away from the first chuck 1 (for example Fig. 9 The left end of the mounting column in the tail chuck 8 is coaxially inserted into the inner hole of the tail chuck 8 to realize the installation of the fixing member 5 on the second chuck 2. There are many ways to fix the tail chuck 8 on the second through hole 21, such as threaded fitting or using a pin to fix the tail chuck 8 on the second through hole 21 in the radial direction. The tail chuck 8 can be in the shape of a disk as a whole, or in the shape of a disk surrounded by multiple circular arc blocks arranged along the circumference, such as a two-lobe circular arc block, a three-lobe circular arc block or a four-lobe circular arc block.

[0060] For example, the inner hole of the tail chuck 8 has an internal thread, and the inner end of the mounting column 51 has an external thread that matches the internal thread, thereby fixing the inner end of the mounting column 51 in the inner hole of the tail chuck 8, or other fixing methods can be used, such as interference fit, or spot welding and other installation methods.

[0061] like Figure 2 , Figure 3 and Figure 7 As shown, the machine tool 3 also includes a balance pipe 71 and a plurality of support frames 72 disposed outside the machine tool 3. One end of the balance pipe 71 (e.g. Figure 3 The left end of the first chuck 2 extends into the first through hole 11 and is coaxially fixed on the first bushing 6 away from the inner end of the second chuck 2 ( Figure 3 The left end of the first through hole 11 is protruded from the first through hole 11 and mounted on a plurality of support frames 72. The inner hole of the first bushing 6 and the inner hole of the balance tube 71 are used to install the pipe to be drawn. When the pipe to be drawn is placed in the inner hole of the first bushing 6, one end of the pipe to be drawn extends out of the first bushing 6, passes through the cavity surrounded by the rollers, and is sleeved on the fixing member 5. The other end extends out of the first bushing and is mounted in the inner hole of the balance tube 71. When the pipe is drawn, the other end of the pipe is mounted in the balance tube 71, and the balance tube 71 is mounted on the support frame 72 to prevent the pipe from warping or jumping when the roller 41 rolls one end of the pipe, thereby ensuring that the axis of the pipe remains in the same straight line during the pipe drawing process, further improving the quality of the pipe drawing.

[0062] The support frame 72 may be multiple or one. Figure 2As shown, in this embodiment, there are two support frames 72. Of course, the number of support frames 72 can be set according to actual needs. Generally, the longer the length of the pipe to be pulled, the longer the length of the balance pipe 71 and the more support frames 72 are set.

[0063] like Figure 7 As shown, the inner end of the first bushing 6 ( Figure 7 The hole wall of the first bushing 6 (the right end in the middle) is provided with a radially inwardly recessed annular step 62, so that the inner hole of the first bushing 6 is a stepped hole, and the end of the balance tube 71 is installed on the annular step 62. For example, the balance tube 71 is installed on the annular step by threading. The setting of the annular step is convenient for the installation and positioning of the balance tube 71 on the one hand, and on the other hand, after the balance tube 71 is installed in place on the first bushing 6, the inner wall of the balance tube 71 can be as flush as possible with the inner wall of the first bushing 6 avoiding the position of the balance tube 71, so as to ensure that when the pipe is installed in the inner hole of the first bushing 6 and the balance tube 71, the pipe can be installed in place, and there is a reserved same gap between the outer wall of the pipe and the inner wall of the first bushing 6 and the balance tube 71. During the pipe drawing process, the pipe can smoothly move forward continuously with the fixing part to realize a continuous pipe drawing process. Optionally, the other end of the first bushing 6 away from the outer edge 61 does not extend out of the first chuck 1.

[0064] like Figure 3 As shown, the end of the first chuck 1 away from the second chuck 2 ( Figure 3 The first chuck 1 is coaxially mounted on the hollow rotating spindle 9 of the machine tool 3. When the hollow rotating spindle 9 on the machine tool 3 is driven to rotate by the driver, the first chuck 1 and the roller assembly 4 fixed on the first chuck 1 are driven to rotate, thereby realizing that the first chuck 1 is rotatably mounted on the machine tool 3.

[0065] For example, the end of the first chuck 1 is fixed to the hollow rotating spindle 9 through a flange, the machine tool 3 is L-shaped, the horizontal part of the L-shape is the machine body, the vertical part of the L-shape is the machine head, the hollow rotating spindle 9 is rotatably installed in the inner hole of the machine head, and the second chuck 2 is located outside the machine head and close to the end surface of one side of the machine body. The above-mentioned second chuck 2 and the sliding mechanism (mentioned in the following) are both installed on the machine body.

[0066] Correspondingly, the other end of the balance pipe 71 ( Figure 3 The right end in the middle) passes through the first chuck 1, the flange and the inner hole of the hollow rotating spindle 9 in sequence, extends outward from the machine head, and is then installed on the support frame 72.

[0067] The second chuck 2 is slidably mounted on the machine tool 3 via a sliding mechanism. Figure 4As shown, the sliding mechanism includes a guide rail 101, a slider 102 and a driving assembly, wherein the guide rail 101 can be one, two or more, and the guide rail 101 extends along the sliding direction of the second chuck 2. The slider 102 is slidably arranged on the guide rail 101, and the end of the second chuck 2 facing away from the first chuck 1 (such as Figure 4 The left end of the second chuck 2 in the middle is fixed on the slider 102, and a driving component drives the slider 102 to slide on the guide rail 101.

[0068] The driving assembly includes a driver 1031, a gear 1032 and a rack 1033. The driver 1031 can be a rotary motor, which is mounted on the top of the slider 102. The rotary shaft of the rotary motor passes through the slider 102 and extends downward. The gear 1032 is fixed on the bottom of the rotary shaft. The rack 1033 is fixed on the machine body and is located between the two guide rails 101 and arranged parallel to the guide rails 101. When the rotary motor rotates, the gear 1032 is driven to rotate and the gear moves on the rack 1033 at the same time, thereby driving the slider 102 to slide on the guide rail 101. By simply changing the rotation direction of the rotary motor, the slider 102 can slide back and forth on the guide rail 101, so that the second chuck 2 can be slidably arranged on the machine tool 3.

[0069] In addition, optimally, when using the above-mentioned tube drawing device to draw the tube, in order to further ensure that the inner diameter of the tube at different positions is uniform and that the inner wall of the tube does not have defects such as friction marks or scratches, relative to the tube drawing device in the background technology, the roller in this embodiment is used as a tool, and the tool width (that is, the distance between the two axial surfaces of the roller along its axial direction) L1 is reduced by 23% to 25% relative to the tool width L0 of the tool in the background technology, that is, L1 = (75% to 77%) L0, so as to reduce the rolling pressure of the tool on the outer wall of the tube; at the same time, the pitch P1 formed by the tool on the outer wall of the tube is increased by 41% to 45% relative to the pitch P0 formed by the tool on the outer wall of the tube in the background technology, that is, P1 = (1.41 to 1.45) P0, so as to reduce the rolling pressure on the outer wall of the tube, thereby ensuring that the required inner diameter threaded tube is formed while the inner diameter size at different positions of the tube is more uniform.

[0070] As a variation of the sliding mechanism, the sliding mechanism may also be other structures. For example, the driving component in the sliding mechanism may be directly a telescopic cylinder, and the telescopic shaft of the telescopic cylinder is directly connected to the slider 102 to drive the slider 102 to slide back and forth.

[0071] As a variation of the above-mentioned embodiment, the above-mentioned balance tube 71 and support frame 72 may not be provided, and correspondingly, there is no need to provide an annular step on the first bushing 6. In order to ensure that the tube does not warp or jump during the tube drawing process, the axial length of the first bushing 6 can be made longer. Even if the axial length of the first bushing 6 is not increased, the first bushing 6 itself can prevent a certain amount of jumping or warping of the tube.

[0072] As a variation of any of the above embodiments, the tail chuck 8 may not be provided, and the inner end of the fixing member 5 may be directly fixed to the inner hole of the second chuck 2. Alternatively, the outer edge 61 may not be provided on the first bushing 6 in the first through hole 11 of the first chuck 1. For example, the end face of one end of the first bushing 6 is flush with the end face of the first chuck 1, which can also play the role of installation in place. As a further variation, the first bushing 6 may not be provided on the first chuck 1, and the pipe may be directly installed in the first through hole 11 of the first chuck 1. The first through hole 11 itself can also play the role of limiting the position of the pipe and preventing the pipe from jumping.

[0073] As a variation of any of the above embodiments, the support column 52 in the fixing member 5 may also be a solid structure instead of a hollow structure. In this case, the force of the roller 41 rolling the pipe can be appropriately adjusted to be small, and it can also prevent the inner wall of the pipe corresponding to the support column 52 from having as few defects as possible, such as friction marks or scratches. As a further variation, the radial diameters of the support column 52 and the mounting column can also be equal. Or the fixing member 5 can also be other structures. For example, the fixing member 5 includes a chuck and a support column 52 fixed on the chuck, the chuck clamps the end of the pipe, and the support column 52 extends into the pipe to support the position where the pipe starts to form threads.

[0074] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A threaded pipe drawing device, characterized in that: The machine tool comprises a first chuck (1) and a second chuck (2) which are opposite to each other; the second chuck (2) is slidably arranged on a machine tool (3) in a direction approaching or moving away from the first chuck (1); the first chuck (1) is rotatably arranged on the machine tool (3) and the first chuck (1) is provided with a first through hole (11) extending in the sliding direction of the second chuck (2); A plurality of roller assemblies (4) are arranged on the first chuck (1) and extend out of the end of the first chuck facing the second chuck and are evenly located on the outer periphery of the first through hole (11) along the circumference of the first through hole (11); any of the roller assemblies (4) has a rotatable roller, and the circumferential outer walls of the rollers of the plurality of roller assemblies (4) form a cavity connected to the first through hole (11); A fixing member (5) is coaxially mounted on the second chuck (2) with the first through hole (11), and a front end of the fixing member (5) away from the second chuck (2) forms a rolling area at a starting position between the fixing member (5) and the roller when the front end of the fixing member (5) slides into the cavity along with the second chuck (2); The fixing member (5) comprises a mounting column (51) mounted on the second chuck (2) and a support column (52) fixed on the mounting column (51); the radial diameter of the support column (52) is smaller than the radial diameter of the mounting column (51); and a rolling area at the starting position is formed between the support column (52) and the roller.

2. The threaded pipe drawing device according to claim 1, characterized in that: The inner cavity of the support column (52) is a hollow structure.

3. The threaded tube drawing device according to claim 1 or 2, characterized in that: It also comprises a first bushing (6) coaxially arranged in the first through hole (11), and the inner hole of the first bushing (6) is used for installing the pipe to be drawn.

4. The threaded pipe drawing device according to claim 3, characterized in that: It also includes a balance tube (71) and at least one support frame (72) arranged outside the machine tool (3), one end of the balance tube (71) extends into the first through hole (11) and is coaxially fixed on the first bushing (6) away from the inner end of the second chuck (2), and the other end extends out of the first through hole (11) and is installed on the support frame (72); the inner hole of the first bushing (6) and the inner hole of the balance tube (71) are used together for the installation of the pipe to be drawn.

5. The threaded pipe drawing device according to claim 4, characterized in that: An annular step (62) that is recessed radially inward is provided on the hole wall at the inner side end of the first bushing (6), so that the inner hole of the first bushing (6) is a stepped hole, and the end of the balance pipe (71) is mounted on the annular step (62).

6. The threaded pipe drawing device according to claim 4 or 5, characterized in that: The end of the first chuck (1) away from the second chuck (2) is coaxially mounted on the hollow rotating spindle (9) of the machine tool (3); The other end of the balance tube (71) passes through the first chuck (1) and the inner holes of the hollow rotating spindle (9) in sequence and protrudes out of the machine tool (3).

7. The threaded pipe drawing device according to claim 3, characterized in that: An outer edge (61) protruding radially outward is provided on the end of the first bushing (6) close to the outer end of the second chuck (2), and the outer edge (61) abuts against the end surface of the end of the first chuck (1).

8. The threaded tube drawing device according to any one of claims 1, 2, 4, 5 or 7, characterized in that: The second chuck (2) is provided with a second through hole (21) coaxial with the first through hole (11); the tube pulling device also includes a tail chuck (8) coaxially arranged in the second through hole (21), and the inner end of the fixing member (5) away from the first chuck (1) is inserted into the inner hole of the tail chuck (8).

9. The threaded pipe drawing device according to any one of claims 1, 2, 4, 5 or 7, characterized in that: The second chuck (2) is slidably arranged on the machine tool (3) via a sliding mechanism; The sliding mechanism comprises a guide rail extending along the sliding direction of the second chuck (2), a slider slidably arranged on the guide rail, an end of the second chuck (2) facing away from the first chuck (1) is fixed to the slider, and a driving component driving the slider to slide on the guide rail.

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