CN110653287A

CN110653287A - Pipe pulling device for threaded pipe

Info

Publication number: CN110653287A
Application number: CN201910904230.3A
Authority: CN
Inventors: 方洪; 谭振兴; 杨立福; 胡窕窕; 万观新; 卢傲; 杨代坤; 赵凯凯; 钱兵保; 石景祯
Original assignee: HANGZHOU SHENSHI ENERGY CONSERVATION TECHNOLOGY Co Ltd
Current assignee: HANGZHOU SHENSHI ENERGY CONSERVATION TECHNOLOGY Co Ltd
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2020-01-07

Abstract

The invention discloses a pipe drawing device of a threaded pipe, which comprises a first chuck, a second chuck, a plurality of groups of roller assemblies and a fixing piece. A cavity communicated with the first through hole is formed between the circumferential outer walls of the rollers of the plurality of groups of roller assemblies in a surrounding manner; and a rolling area at the initial position is formed between the front end of the fixing piece far away from the second chuck and the roller when the front end of the fixing piece slides into the cavity along with the second chuck. The pipe drawing device does not have the lining core and the core head to support the inner wall of the pipe, so that the defects of friction marks or scratches and the like cannot be formed on the inner wall of the pipe in the pipe drawing process; when the roller rolls the thread at the initial position of the pipe, the front end of the fixing piece extends into the cavity to support the inner wall of the initial thread rolling position of the pipe, so that when the roller rolls the thread forming position at the initial position of the pipe, the phenomenon that the inner diameter of the pipe is instantly reduced is avoided; so that the inner diameter of the pulled threaded pipe at different positions is uniform in size.

Description

Pipe pulling device for threaded pipe

Technical Field

The invention relates to the technical field of processing of threaded pipes, in particular to a pipe pulling device of a threaded pipe.

Background

At present, threaded pipes are mostly applied to the refrigeration industry, for example, threaded pipes adopted in heat exchangers are reused in industrial places such as water heaters, air conditioners, refrigerators and cold water/oil cooling units, and along with market diversification, threaded pipes are also gradually applied to food-grade water purifiers.

Most of the existing threaded pipes are pulled out by adopting a cored pull pipe, as shown in fig. 1, the cored pull pipe device comprises a left chuck a1, a right chuck a2, a chuck a3 arranged on the left chuck, a bushing arranged in an inner hole of the right chuck, 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 core; and a plurality of rollers which surround the periphery of the core print and are uniformly arranged are arranged on the left end face of the right chuck, a rolling area is formed between the plurality of rollers and the core print, and the rollers are used as cutters and used for rolling threads on the outer wall surface of the pipe. The left chuck can slide towards the direction close to or away from the right chuck under the drive of the drive mechanism; the right chuck and the roller are driven by a rotating main shaft on the machine tool to do circular motion.

When the tube drawing device with the structure is used for drawing a tube, the tube is placed in the inner hole of the lining and the inner hole of the right chuck, the left end of the tube extends out of the lining, is sequentially sleeved on the lining core and the core head and extends outwards, and is finally sleeved on the chuck, and the core head and the lining core all play a supporting role on the inner wall of the tube. When the driving mechanism drives the left chuck and the chuck to drive the pipe to move towards the direction far away from the right chuck, the right chuck rotates simultaneously to enable the roller to roll and support the outer wall surface of the pipe outside the core print, so that threads are formed on the outer wall surface of the pipe, and the pulling-out process of the threaded pipe is completed.

However, in the tube drawing device, rolling force is always generated between the core print and the roller in the tube drawing process, the core print is supported on the inner wall surface of the tube, and the core print is easily rolled by the roller to generate defects such as friction marks or scratches on the inner wall of the tube, so that the quality of the threaded tube is affected. For example, when the threaded pipe is used for conveying drinking water, the drinking water is easy to breed bacteria at the friction trace position of the inner wall of the threaded pipe, and the human health is affected. If the lining core and the core print are not arranged, although no trace is formed on the inner wall of the threaded pipe, when the roller initially rolls the pipe, the roller easily applies instant rolling pressure to the pipe, the inner diameter of the pipe is reduced by instant rolling, and the uniformity of the inner diameter size of the pulled threaded pipe at different positions is affected.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is that when the existing pipe drawing device is provided with the lining core and the core print, traces exist on the inner wall surface of the drawn threaded pipe, and the quality of the threaded pipe is influenced; if the lining core and the core print are not arranged, the uniformity of the inner diameter size of the pulled threaded pipe at different positions is poor.

The invention provides a pipe drawing device of a threaded pipe, which comprises a first chuck and a second chuck which are opposite; the second chuck is slidably arranged on the machine tool in the direction towards 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 along the sliding direction of the second chuck;

the roller assemblies are arranged on the first chuck, extend out of the end part of the first chuck facing the second chuck and are uniformly positioned on the periphery of the first through hole along the circumferential direction of the first through hole; any one of the roller assemblies is provided with a rotatable roller, and a cavity communicated with the first through hole is defined between the circumferential outer walls of the rollers of the plurality of groups of roller assemblies;

and the fixing piece is coaxially arranged on the second chuck with the first through hole, and a rolling area at an initial position is formed between the front end of the fixing piece, which is far away from the second chuck and the roller when the front end of the fixing piece slides with the second chuck and extends into the cavity.

Optionally, in the above pipe pulling device for threaded pipes, the fixing element includes an installation column installed on the second chuck and a support column fixed on the installation column, a radial diameter of the support column is smaller than a radial diameter of the installation column, and a rolling area of the starting position is formed between the support column and the roller.

Optionally, in the pipe pulling device for the threaded pipe, the inner cavity of the supporting column is of a hollow structure.

Optionally, the pipe pulling device for the threaded pipe further comprises a first bushing coaxially arranged in the first through hole, and an inner hole of the first bushing is used for installing a pipe to be pulled.

Optionally, the pipe pulling device for the threaded pipe further comprises a balance pipe and at least one support frame arranged outside the machine tool, wherein one end of the balance pipe extends into the first through hole and is coaxially fixed on the first bushing at the inner side end far away from the second chuck, and the other end of the balance pipe extends out of the first through hole and is mounted on the support frame; the inner hole of the first bushing and the inner hole of the balance pipe are used for installing the pipe to be pulled together.

Optionally, in the pipe pulling device for the threaded pipe, a radially inwardly recessed annular step is arranged on a hole wall of the inner side end of the first bushing, so that an inner hole of the first bushing is a stepped hole, and an end of the balance pipe is mounted on the annular step.

Optionally, in the pipe drawing device for threaded pipes, the end of the first chuck, which is far away from the second chuck, is coaxially mounted on the hollow rotary spindle of the machine tool;

the other end of the balance pipe sequentially penetrates through the first chuck and the inner hole of the hollow rotating main shaft and extends out of the machine tool.

Optionally, in the above pipe pulling device for threaded pipes, an end of the first bushing close to the outer end of the second chuck is provided with an outer edge protruding radially outward, and the outer edge abuts against an end face of the end of the first chuck.

Optionally, in the above pipe pulling device for a threaded pipe, the second chuck is provided with a second through hole coaxial with the first through hole; the tube drawing device further comprises a tail chuck coaxially arranged in the second through hole, and the inner side end, far away from the first chuck, of the fixing piece is inserted into the inner hole of the tail chuck.

Optionally, in the above pipe drawing device for a threaded pipe, the second chuck is slidably disposed on the machine tool through a sliding mechanism;

slide mechanism includes the edge guide rail that second chuck slip direction extends, establishes slidable slider on the guide rail, dorsad on the second chuck first chuck's one end is fixed on the slider, and the drive the slider is in gliding drive assembly on the guide rail.

The technical scheme of the invention has the following advantages:

1. the invention provides a pipe drawing device of a threaded pipe, which comprises a first chuck and a second chuck which are opposite; a plurality of groups of roller components and fixing parts. The second chuck is slidably arranged on the machine tool in the direction towards 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 along the sliding direction of the second chuck; the plurality of groups of roller assemblies are arranged on the first chuck, extend out of the end part of the first chuck facing the second chuck and are uniformly positioned on the periphery of the first through hole along the circumferential direction of the first through hole; any one of the roller assemblies is provided with a rotatable roller, and a cavity communicated with the first through hole is defined between the circumferential outer walls of the rollers of the plurality of groups of roller assemblies; the fixing piece and the first through hole are coaxially arranged on the second chuck, and a rolling area at an initial position is formed between the front end of the fixing piece, far away from the second chuck, and the roller when the front end of the fixing piece slides along with the second chuck and extends into the cavity. .

According to the pipe drawing device with the structure, as the lining core and the core head of the pipe 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 pipe, the defects such as friction marks or scratches cannot be formed on the inner wall of the pipe in the pipe drawing process; meanwhile, when the rollers roll threads at the initial position of the pipe, the front end of the fixing piece extends into a cavity surrounded by the rollers, and the front end of the fixing piece supports the inner wall of the initial thread rolling position of the pipe, so that when the rollers roll the initial thread rolling position of the pipe, the phenomenon that the inner diameter of the pipe is instantly reduced is avoided; the internal diameter size of the threaded pipe at different positions is uniform, the quality of the pulled threaded pipe is improved, the threaded pipe can be used in the water purifier industry, and human health cannot be affected when the human body drinks water conveyed in the threaded pipe.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is an enlarged view of a part of a tube drawing device in the prior art;

FIG. 2 is a schematic structural diagram of a tube drawing device provided in an embodiment of the present invention;

FIG. 3 is an enlarged longitudinal cross-sectional view of a portion of the pull tube assembly of FIG. 2;

FIG. 4 is an enlarged view of a portion of the slide mechanism of the pull tube apparatus of FIG. 2;

FIG. 5 is a schematic view of the combination of the first chuck, the second chuck, the fixing member and the roller assembly of the pipe drawing device of FIG. 2;

FIG. 6 is an exploded view of the first chuck, the second chuck, the fixing member and the roller assembly of FIG. 5;

FIG. 7 is an enlarged partial view of the first chuck, the first bushing and the balance tube of the tube drawing device of FIG. 3;

FIG. 8 is a schematic structural view of the first chuck, the roller assembly and the first bushing of FIG. 5;

FIG. 9 is a schematic view of the second chuck, the fixture and the tail chuck of FIG. 5;

description of reference numerals:

1-a first chuck; 11-a first via;

2-a second chuck; 21-a second via;

3-a machine tool;

4-a roller assembly; 41-a roller; 42-intermediate shaft; 43-jaws;

5-a fixing piece; 51-a mounting post; 52-support column;

6-a first bushing; 61-outer edge; 62-an annular step;

71-a balance tube; 72-a support frame;

8-tail chuck;

9-hollow rotating main shaft;

101-a guide rail; 102-a slide block; 1031-driver; 1032-gear; 1033-rack.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

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

Example 1

The present embodiment provides a pipe drawing device for threaded pipes, as shown in fig. 2 to 9, which includes a machine tool 3, a first chuck 1, a second chuck 2, a first bushing 6, a fixing member 5, and several sets of roller assemblies 4.

As shown in fig. 2 and 3, the first chuck 1 and the second chuck 2 are oppositely arranged on the machine tool 3, and the second chuck 2 is slidably provided on the machine tool 3 in a direction toward or away from the first chuck 1; the first chuck 1 is rotatably provided on the machine tool 3, and a first through hole 11 extending in the sliding direction of the second chuck 2 is provided on the middle portion of the first chuck 1. For example, the sliding direction of the second chuck 2 is the left-right direction in fig. 2.

The plurality of groups of roller assemblies 4 are arranged on the end surface (the left end of the first chuck 1 in fig. 3) of the first chuck 1 facing the second chuck 2 and are uniformly arranged on the periphery of the first through hole 11. Any roller assembly 4 is provided with a rotatable roller 41, a cavity is enclosed between the circumferential outer wall surfaces of the rollers 41 of a plurality of groups of roller assemblies 4 and is communicated with the first through hole, and the roller 41 is used as a cutter to generate rolling pressure on the outer wall surface of the pipe to be pulled so as to form threads on the outer wall surface of the pipe.

For example, four sets of roller assemblies 4 are provided in the present embodiment, and a cavity is defined between the circumferential outer wall surfaces of the four rollers 41. Each set of roller assemblies 4 has the same structure, and the specific structure of one set of roller assemblies 4 will be described. As shown in fig. 6 and 7, the roller assembly 4 includes the roller 41, the intermediate shaft 42, and the jaws 43, the two jaws 43 are fixed to each other and form a through hole for the intermediate shaft 42 to pass through, and the jaws 43 are fixed to the end surface of the first chuck 1. The bottom of the intermediate shaft 42 is locked to the ends of the jaws 43 using locking elements, such as lock nuts or limit pins. The roller 41 is rotatably arranged on the end part of the intermediate shaft 42 to realize autorotation; when the first chuck 1 rotates, the four groups of roller assemblies 4 are driven to rotate, so that the four rollers 41 revolve with the first chuck, and the rotating rollers 41 apply an actual rolling force on the outer wall of the pipe to be pulled passing through the cavity. That is, the roller 41 rotates on the intermediate shaft 42 and revolves along with the first chuck 1, and the roller 41 rotates while being in rolling contact with the outer wall surface of the pipe, thereby buffering the rolling stress of the roller 41 on the outer wall surface of the pipe.

As shown in fig. 3, 5, 6 and 8, the first bushing 6 is coaxially disposed in the first through hole 11, and an inner hole of the first bushing 6 is used for installing a pipe to be pulled. The first liner 6 is not provided with the core and the core print of the background art. To facilitate the installation of the first bush 6, an end portion (e.g., the left end in fig. 7) of the first bush 6 close to the outer end of the second chuck 2 is provided with an outer edge 61 protruding radially outward, and the outer edge 61 abuts on an end face of the end portion of the first chuck 1, thereby facilitating the installation and positioning of the first bush 6. The first bushing may be mounted in the first through hole in a variety of fastening manners, such as a threaded fit or a plug fit.

As shown in fig. 5, 7 and 9, the fixing member 5 is coaxially installed on an end portion of the second chuck 2 facing the first chuck 1 (for example, a left end of the first chuck 1 in fig. 9) with the first through hole 11, a front end of the fixing member 5 away from the second chuck 2 (for example, a right end of the fixing member 5 in fig. 7) is adapted to extend into or out of a cavity surrounded by the plurality of rollers 41 when sliding with the second chuck 2, and a rolling area of a starting position is formed between the front end of the fixing member 5 and the rollers 41 when extending into the cavity.

When the pipe drawing device is required to draw a pipe, the first chuck 1 moves towards the direction close to the second chuck 2 (for example, the second chuck moves rightwards in fig. 5), so that the front end of the fixing piece 5 extends into the cavity and forms a rolling area of an initial position opposite to the roller 41; a pipe to be pulled is arranged in an inner hole of the first bush 6, and one end of the pipe extends out of the first bush 6 and is sleeved on the fixing piece 5; at the moment, the first chuck 1 rotates to drive all the roller assemblies 4 to rotate, the front end of the fixing piece 5 plays a role in supporting the inner wall surface of the pipe sleeved on the fixing piece, the roller 41 just rolls the outer wall surface of the pipe sleeved at the front end of the fixing piece 5, and the outer wall surface just serves as the starting position of the thread formed by the pipe; the second chuck 2 drives the pipe to move towards the direction away from the first chuck 1 (for example, the second chuck 2 moves leftwards in fig. 5) while the roller 41 rotates, so that the pipe is rolled by the rotating roller 41 in the moving process, the outer wall surface of the pipe forms a thread, and the phenomenon that the inner diameter of the pipe is instantaneously reduced when the pipe is instantaneously rolled by the roller 41 at the initial position can be prevented due to the supporting function of the front end of the fixing piece; along with the continuous movement of the second chuck 2 in the direction away from the first chuck 1, the front end of the fixing member 5 is drawn out from the cavity enclosed by the plurality of rollers 41, at this time, the front end of the fixing member 5 does not support the inner wall of the pipe in the cavity enclosed by the rollers 41 any more, and because the inner wall of the pipe is not provided with any other supporting structure, the roller 41 does not form friction marks or scratches on the inner wall surface of the pipe when rolling the outer wall surface of the pipe, thereby ensuring the size of the inner diameter of the pipe at the initial position to form threads, making the inner diameter of the drawn out threaded pipe at different positions uniform, and meanwhile, in the process of forming the threads on the outer wall surface of the pipe at other positions, the inner wall of the pipe has no friction marks or scratches, improving the quality of the threaded pipe, further making the threaded pipe be used in the water purifier industry, and ensuring that when a human, the health of human body is not affected.

As for the structure of the fixing member 5, as shown in fig. 3, 5 and 9, the fixing member 5 includes a mounting post 51 mounted on the second chuck 2 and a supporting post 52 fixed on the mounting post 51, a radial diameter of the supporting post 52 is smaller than a radial diameter of the mounting post 51, a rolling area of an initial position is formed between the supporting post 52 and the roller 41, a step surface is formed between the supporting post 52 and the mounting post 51, when one end of a pipe to be pulled is sleeved on the mounting post, a certain gap is formed between the pipe sleeved outside the supporting post 52 and an outer wall surface of the supporting post 52, and when the roller 41 rolls the pipe outside the supporting post 52, especially the step surface has a buffering effect, which does not affect the firmness of the sleeving of the pipe on the mounting post.

Preferably, the inner cavity of the supporting column 52 is a hollow structure, and when the roller 41 rolls the pipe outside the supporting column 52, the hollow structure of the supporting column 52 can release the rolling force of the roller 41 acting on the supporting column 52 in the hollow inner cavity, so as to avoid the phenomenon that the rolling force acts on the inner wall of the pipe to form friction marks or scratches on the inner wall of the pipe, and the like.

As shown in fig. 6 and 9, the second chuck 2 is provided at a middle portion thereof with a second through hole 21 coaxial with the first through hole 11; the tube drawing device further comprises a tail chuck 8 coaxially arranged in the second through hole 21, and the inner end (such as the left end of the mounting column in fig. 9) of the mounting column 51 in the fixing piece 5 far away from the first chuck 1 is coaxially inserted into the inner hole of the tail chuck 8 so as to realize the installation of the fixing piece 5 on the second chuck 2. There are various ways to fix the tail chuck 8 to the second through hole 21, such as screwing or radially fixing the tail chuck 8 to the second through hole 21 by using a pin. The tail chuck 8 may be a disk as a whole, or a disk surrounded by multiple circular arc blocks arranged along the circumference, such as two circular arc blocks, three circular arc blocks, or four circular arc blocks.

For example, the inner hole of the tail chuck 8 has an internal thread, and the inner end of the mounting post 51 has an external thread matching with the internal thread, so as to fix the inner end of the mounting post 51 in the inner hole of the tail chuck 8, or other fixing methods, such as interference fit, or spot welding or the like, may also be adopted.

As shown in fig. 2, 3 and 7, the apparatus further includes a balance pipe 71 and a plurality of support frames 72 disposed outside the machine tool 3, wherein one end (for example, the left end in fig. 3) of the balance pipe 71 extends into the first through hole 11 and is coaxially fixed to the inner end (the left end in fig. 3) of the first bushing 6, which is far away from the second chuck 2, and the other end extends out of the first through hole 11 and is mounted on the plurality of support frames 72; the inner hole of the first bushing 6 and the inner hole of the balance pipe 71 are used together for installing the pipe to be pulled. When waiting to draw the tubular product to place the hole at first bush 6, the one end of waiting to draw the tubular product stretches out and cup joints on mounting 5 behind the cavity that first bush 6 outer passed the gyro wheel and enclose, the other end stretches out first bush and installs in the hole of balance pipe 71, when drawing the tubular product, the other end of tubular product is installed in balance pipe 71, balance pipe 71 installs again on support frame 72, when preventing that gyro wheel 41 from rolling press the one end of tubular product, the phenomenon that the tubular product upwarps or beats appears, and then ensure that tubular product is in the trombone process, the axis of tubular product keeps on same straight line, further improve the quality of trombone.

As shown in fig. 2, the number of the support frames 72 in this embodiment is two, and the number of the support frames 72 can be determined according to actual requirements, wherein generally, the longer the length of the pipe to be pulled is, the longer the length of the balance pipe 71 is, and the greater the number of the support frames 72 is.

As shown in fig. 7, an annular step 62 recessed radially inward is provided on a hole wall of an inner end (right end in fig. 7) of the first bush 6 so that the inner hole of the first bush 6 is a stepped hole, and an end of the balance pipe 71 is fitted on the annular step 62. For example, the balance pipe 71 is installed on the annular step in a threaded manner, the arrangement of the annular step is convenient for the installation and positioning of the balance pipe 71 on one hand, and after the balance pipe 71 is installed on the first bushing 6 in place on the other hand, the inner wall of the balance pipe 71 can be aligned with the inner wall of the first bushing 6 away from the position of the balance pipe 71 as far as possible, so that when the pipe is installed in the inner holes of the first bushing 6 and the balance pipe 71, the pipe can be installed in place, the same gap is reserved between the outer wall of the pipe and the inner walls of the first bushing 6 and the balance pipe 71, and in the pipe pulling process, the pipe can move forward continuously along with the fixing piece smoothly, and the continuous pipe pulling process is realized. Optionally, the other end of the first bush 6, which is far from the outer edge 61, does not protrude outside the first chuck 1.

As shown in fig. 3, the end (right end in fig. 3) of the first chuck 1 far from the second chuck 2 is coaxially installed on a hollow rotary spindle 9 of the machine tool 3, and when the hollow rotary spindle 9 on the machine tool 3 is driven by a driver to rotate, the first chuck 1 and the roller assembly 4 fixed on the first chuck 1 are driven to rotate, so that the first chuck 1 is rotatably installed on the machine tool 3.

For example, the end of the first chuck 1 is fixed with a hollow rotating main shaft 9 through a flange, the machine tool 3 is in an L shape, the horizontal part of the L shape is used as a machine body, the vertical part of the L shape is used as a machine head, the hollow rotating main shaft 9 is rotatably installed in an inner hole of the machine head, and the second chuck 2 is positioned outside the machine head and close to the end surface of one side of the machine body. The second chuck 2 and the slide mechanism (mentioned in the following) are mounted on the body.

Correspondingly, the other end (right end in fig. 3) of the balance pipe 71 passes through the first chuck 1, the flange and the inner hole of the hollow rotary spindle 9 in sequence, extends out of the machine head, and is then mounted on the support frame 72.

The second chuck 2 is slidably provided on the machine tool 3 by a slide mechanism. As shown in fig. 4, the sliding mechanism includes a guide rail 101, a slider 102 and a driving assembly, wherein the guide rail 101 may be one, two or more, the guide rail 101 extends along the sliding direction of the second chuck 2, the slider 102 is slidably disposed on the guide rail 101, an end of the second chuck 2 facing away from the first chuck 1 (e.g., a left end of the second chuck 2 in fig. 4) is fixed on the slider 102, and the driving assembly drives the slider 102 to slide on the guide rail 101.

The drive assembly includes a driver 1031, a gear 1032, and a rack 1033. Wherein, the driver 1031 may be a rotary motor, the rotary motor is installed on the top of the slider 102, the rotary shaft of the rotary motor extends downward through the slider 102, the gear 1032 is fixed on the bottom of the rotary shaft, and the rack 1033 is fixed on the machine body and located between the two guide rails 101, and is arranged in parallel with the guide rails 101. When the rotating motor rotates, the gear 1032 is driven to rotate and the gear moves on the rack 1033 at the same time, so as to drive the sliding block 102 to slide on the guide rail 101, and only the rotating direction of the rotating motor needs to be changed, so that the sliding block 102 can slide on the guide rail 101 in a reciprocating manner, and the second chuck 2 can be slidably arranged on the machine tool 3.

Preferably, when the pipe drawing device is used to draw a pipe, the roller in this embodiment is used as a roller in comparison with the pipe drawing device in the background art to further ensure that the inner diameters of different positions of the pipe are uniform and the inner wall of the pipe does not generate friction marks or scratchesThe width of the tool (i.e. the distance between two axial faces of the roller in its axial direction) L₁Compared with the cutter width L of the cutter in the prior art₀Reduced by 23% -25%, namely L₁＝(75％～77％)L₀So as to reduce the rolling force of the cutter on the outer wall surface of the pipe; simultaneously, the cutter forms a screw pitch P on the outer wall surface of the pipe₁Compared with the pitch P formed on the outer wall surface of the pipe by the cutter in the prior art₀Increased by 41-45%, namely P₁＝(1.41～1.45)P₀So as to reduce the rolling force on the outer wall surface of the pipe and ensure that the inner diameter sizes of different positions of the pipe are more uniform while forming the threaded pipe with the required inner diameter.

As a variation of the sliding mechanism, the sliding mechanism may also have other structures, for example, the driving assembly in the sliding mechanism may be directly a telescopic cylinder, and a telescopic shaft of the telescopic cylinder is directly connected to the sliding block 102 to drive the sliding block 102 to slide back and forth.

As a modification of the above embodiment, the balance tube 71 and the support frame 72 may not be provided, and accordingly, the first bushing 6 does not need to be provided with an annular step, so as to ensure that the tube does not warp or jump during tube drawing, the length of the first bushing 6 in the axial direction thereof may be made longer, and even if the axial length of the first bushing 6 is not increased, the first bushing 6 itself may also play a role in preventing the tube from jumping or warping to some extent.

As a modification 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 disposed on the first bushing 6 in the first through hole 11 of the first chuck 1, for example, an end surface of one end of the first bushing 6 is flush with an end surface of the first chuck 1, and the first bushing can also be mounted in place. As a further modification, the first chuck 1 may not be provided with the first bushing 6, and the pipe is directly mounted in the first through hole 11 of the first chuck 1, and the first through hole 11 itself may also play a role in limiting the pipe and preventing the pipe from jumping.

In a modification of any of the above embodiments, the support column 52 of the fixing member 5 may have a solid structure instead of a hollow structure, and in this case, the force with which the roller 41 rolls the pipe can be appropriately adjusted to be small, and defects such as friction marks or scratches can be prevented from occurring as little as possible on the inner wall of the pipe corresponding to the support column 52. As a further variation, the radial diameters of the support post 52 and the mounting post may also be equal. Alternatively, the fixing member 5 may have another structure. For example, the fixing member 5 includes a clamping head and a supporting pillar 52 fixed on the clamping head, the clamping head clamps the end of the pipe, and the supporting pillar 52 extends into the pipe to support the position where the pipe is initially threaded.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A pipe drawing device for threaded pipes, characterized by comprising a first chuck (1) and a second chuck (2) which are opposite; the second chuck (2) is arranged on the machine tool (3) in a sliding way in the direction of approaching to or departing 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 formed in the first chuck (1);

the roller assemblies (4) are arranged on the first chuck (1), extend out of the end part of the first chuck facing the second chuck and are uniformly positioned on the periphery of the first through hole (11) along the circumferential direction of the first through hole (11); any one of the roller assemblies (4) is provided with a rotatable roller, and a cavity communicated with the first through hole (11) is defined between the circumferential outer walls of the rollers of the plurality of groups of roller assemblies (4);

fixing piece (5), with first through-hole (11) are installed coaxially on second chuck (2), keep away from on fixing piece (5) the front end of second chuck (2) is followed second chuck (2) slide and stretch into during the cavity with form the roll extrusion region of initial position between the gyro wheel.

2. The pipe-pulling device for threaded pipes according to claim 1, characterized in that the fixture (5) comprises a mounting post (51) mounted on the second chuck (2) and a support post (52) fixed on the mounting post (51), the radial diameter of the support post (52) is smaller than the radial diameter of the mounting post (51), and a rolling area of the starting position is formed between the support post (52) and the roller.

3. The device for pulling the threaded pipe according to claim 2, wherein the inner cavity of the support column (52) is of a hollow structure.

4. The threaded pipe pulling device according to any one of claims 1 to 3, further comprising a first bushing (6) coaxially arranged in the first through hole (11), wherein an inner hole of the first bushing (6) is used for installing a pipe to be pulled.

5. The device for pulling the threaded pipe according to claim 4, further comprising a balance pipe (71) and at least one support frame (72) arranged outside the machine tool (3), wherein one end of the balance pipe (71) extends into the first through hole (11) and is coaxially fixed on the inner side end of the first bushing (6) far away from the second chuck (2), and the other end of the balance pipe extends out of the first through hole (11) and is mounted on the support frame (72); the inner hole of the first bushing (6) and the inner hole of the balance pipe (71) are used for installing the pipe to be pulled together.

6. The device for pulling the threaded pipe according to claim 5, characterized in that the hole wall of the inner end of the first bushing (6) is provided with an annular step (62) which is recessed radially inwards, 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).

7. The device for pulling threaded pipes according to claim 5 or 6, characterized in that the end of the first chuck (1) remote from the second chuck (2) is mounted coaxially on a hollow rotating spindle (9) of the machine tool (3);

the other end of the balance pipe (71) sequentially penetrates through the first chuck (1) and the inner hole of the hollow rotating main shaft (9) to extend out of the machine tool (3).

8. The device for pulling threaded pipes according to any of claims 4 to 7, characterized in that the end of the first bushing (6) close to the outer end of the second chuck (2) is provided with an outer rim (61) projecting radially outwards, the outer rim (61) abutting against the end face of the end of the first chuck (1).

9. Device for pulling threaded pipes according to any of claims 1 to 8, characterized in that the second chuck (2) is provided with a second through hole (21) coaxial with the first through hole (11); the tube drawing device further comprises a tail chuck (8) coaxially arranged in the second through hole (21), and the inner side end, far away from the first chuck (1), of the fixing piece (5) is inserted into an inner hole of the tail chuck (8).

10. The device for pulling threaded pipes according to any of claims 1 to 9, characterized in that the second chuck (2) is slidably arranged on the machine bed (3) by means of a sliding mechanism;

slide mechanism includes the edge guide rail that second chuck (2) slip direction extends, establishes slidable slider on the guide rail, second chuck (2) are gone up dorsad the one end of first chuck (1) is fixed on the slider, and the drive the slider is in gliding drive assembly on the guide rail.