A pipe stretching machine and a stretching unit

Abstract

The present invention discloses a pipe stretching machine and a stretching unit, belonging to the field of pipe stretching equipment. The transmission of the pipe and the stretching of the pipe can be carried out at the same position but at different heights. The pipe can be transmitted at the side of the equipment to shorten the length of the equipment. A pipe stretching machine of the present invention includes a frame. A transmission device and a flipping device are provided on the frame. A stretching die seat and a clamping trolley for clamping the pipe are provided below the transmission device on the frame. The flipping device can change the position of the pipe transmitted by the transmission device in the vertical direction and transmit the pipe below the transmission device. The stretching die seat is located between the clamping trolley and the flipping device. The clamping trolley is slidably matched with the frame to drag the pipe to move to complete the pipe stretching. The stretched pipe is sent out from the side of the pipe stretching machine.

Description

Technical Field

[0001] The present invention relates to the field of pipe stretching equipment, and in particular to a pipe stretching machine and a stretching unit.

Background Art

[0002] When producing long pipes, generally, thick and short pipes are first produced to shorten the process of producing pipe blanks, and then a stretching machine is used to draw the pipes to produce thin and long pipes, and the length of the pipes will be greatly extended. When producing coiled pipes, the drawn pipes can be coiled and stored, while when producing branch pipes, they cannot be stored in this way, so the production length of the equipment is relatively long.

[0003] In the prior art, secondary stretching is generally used to draw pipes. In this way, although the number of die passes can be reduced and the pipes can be protected from breaking during stretching, the production line of the pipes will be longer and a larger site is required to accommodate the equipment. If the pipes can be conveyed on the side, the equipment for the two stretches can be arranged side by side to shorten the equipment length. Therefore, a special stretching machine needs to be designed to achieve the side conveyance of the pipes and complete the stretching of the pipes during the conveyance process.

Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a pipe stretching machine, in which the conveyance of the pipes and the stretching of the pipes can be carried out at the same position but at different heights, and the pipes can be conveyed on the side of the equipment to shorten the length of the equipment.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A pipe stretching machine includes a frame. A conveying device and a flipping device are provided on the frame. A stretching die seat and a clamping trolley for clamping the pipes are provided below the frame and below the conveying device. The flipping device can change the position of the pipes conveyed by the conveying device in the vertical direction and convey the pipes below the conveying device. The stretching die seat is located between the clamping trolley and the flipping device. The clamping trolley is slidably matched with the frame to drag the pipes to move to complete the stretching of the pipes, and the stretched pipes are discharged from the side of the pipe stretching machine.

[0007] The rack can be divided into two layers. The pipes can be conveyed on the upper layer or the lower layer. When the pipes are conveyed on the upper layer, they are driven by the conveying device and move towards the flipping device. The flipping device can change the position of the pipes, transfer the pipes from the upper layer to the lower layer, and then the pipes can be conveyed on the lower layer of the rack. During the conveying process on the lower layer, the pipes first pass through the stretching die seat to complete the stretching of the ends. After the ends of the pipes protrude from the stretching die seat, the clamping trolley can clamp the pipes. As the clamping trolley moves, it can pull the pipes to move and complete the subsequent pipe drawing process. At the same time, the upper conveying device can convey the pipes while the pipes are being drawn below. The conveying of the pipes and the stretching of the pipes can be carried out at the same position but at different heights, shortening the length of the equipment. The drawn pipes are discharged from the side of the equipment, so there is no need to leave space in the length direction of the equipment to accommodate the stretched pipes.

[0008] Further, the stretching die seat includes a die seat, a stretching die and a peeling die provided on the die seat. As the pipes are conveyed, they will pass through the stretching die and the peeling die in sequence, first stretching and then peeling. The conveying of the pipes and the stretching and peeling of the pipes can be carried out simultaneously at different height positions on the rack.

[0009] Further, the stretching die seat further includes a movable template which can move relative to the die seat, and the peeling die is provided on the movable template. When peeling, a gap needs to be left between the peeling die and the stretching die to facilitate the waste generated after peeling to fall from the gap. The movable template can drive the peeling die to move during the stretching process and change its position relative to the die seat. And when the pipes pass through the stretching die, the movable template can also move towards the pipes and squeeze the pipes so that the pipes pass through the peeling die, thus facilitating the equipment to complete the preliminary peeling operation. The clamping trolley can clamp this section of the peeled pipes for subsequent stretching and peeling.

[0010] Further, the conveying device includes multiple pairs of spaced support frames, and the support frames are provided with first rollers and a first motor for driving the first rollers to roll. The movement of the pipes on the upper layer of the rack is realized through the transmission device. Under the action of the gravity of the pipes themselves, there will be a certain friction force between the pipes and the first rollers. As the first motor drives the first rollers, the first rollers can push the pipes to move continuously while rotating. Multiple pairs of support frames can support the pipes extremely well, enabling the pipes to remain stable during the conveying process.

[0011] Further, the conveying device further includes a clamping component provided on the support frame for clamping the pipes. The clamping component can stabilize the pipes, enabling the pipes to remain stable during the conveying process.

[0012] Further, the clamping member includes a second roller and a lifting cylinder for controlling the lifting of the second roller. The lifting cylinder can control the lifting of the second roller. During the process of conveying the pipe, the pipe is clamped between the first roller and the second roller, increasing the friction between them, so that during the conveying process, the pipe will not slip and can be conveyed more stably.

[0013] Further, the turning device includes a turning disk and a second motor for driving the turning of the turning disk. A sleeve and a first core rod accommodated in the sleeve are provided on the turning disk. The pipe can be sleeved outside the first core rod and accommodated in the sleeve. The turning disk can rotate under the action of the second motor and can drive the sleeve and the first core rod to rotate synchronously while rotating. If the conveying device completes the conveying of the pipe, the pipe will be sleeved outside the first core rod and rotate synchronously with the turning disk, changing its vertical position.

[0014] Further, a second core rod connected to the first core rod is also provided inside the sleeve. The diameter of the second core rod is larger than the diameter of the pipe. A driving member for driving the movement of the second core rod is also provided on the turning disk. Since the diameter of the second core rod is larger, when the driving member pushes the second core rod to move, the second core rod can push the first core rod and the pipe wrapped outside the first core rod to move and push them towards the stretching die seat for stretching the pipe.

[0015] Further, an inner die head is provided at the end of the first core rod. The turning disk is also provided with an adjusting assembly, and the adjusting assembly can adjust the distance between the inner die head and the stretching die seat. The stretching machine includes an inner die and an outer die. The outer die is the stretching die on the stretching die seat, and the inner die is the inner die head. Under the combined action of the inner die head and the stretching die, the stretching of the pipe is realized. During the stretching process, there are certain distance requirements between the outer die and the inner die. During long-term use, the distance between the two will change, and the adjusting assembly can adjust the distance between the two to realize normal processing.

[0016] A stretching unit includes a feeding device and two of the above-mentioned pipe stretching machines. The feeding device and the two pipe stretching machines are arranged side by side, and a pipe transfer mechanism is provided between the two pipe stretching machines to realize the side conveying of the pipe in the equipment. The stretching unit includes two pipe stretching machines, and the pipe can complete secondary stretching. Under the action of the feeding device and the pipe transfer mechanism, the side conveying of the pipe in the stretching machine can be realized, thereby shortening the overall length of the secondary stretching equipment.

[0017] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

Description of the Drawings

[0018] The following further describes the present invention with reference to the drawings:

[0019] Figure 1 It is a schematic structural diagram of the pipe stretching machine in the embodiment of the present invention;

[0020] Figure 2 It is a side view of the pipe stretching machine in the embodiment of the present invention;

[0021] Figure 3 is Figure 2 an enlarged schematic diagram of part A in

[0022] Figure 4 is Figure 2 an enlarged schematic diagram of part B in

[0023] Figure 5 It is a schematic structural diagram of the stretching die holder in the embodiment of the present invention;

[0024] Figure 6 It is a partial top view of the pipe stretching machine in the embodiment of the present invention;

[0025] Figure 7 It is a schematic structural diagram of the pipe stretching machine set in the sixth embodiment of the present invention.

[0026] Reference numerals:

[0027] Frame 100;

[0028] Conveying device 200, support frame 210, first roller 220, first motor 230, clamping member 240, second roller 241, lifting cylinder 242;

[0029] Flipping device 300, flipping disc 310, second motor 320, sleeve 330, first core rod 340, second core rod 350, adjusting assembly 360, adjusting motor 361, adjusting sleeve 362;

[0030] Stretching die holder 400, die base 410, stretching die 420, peeling die 430, movable template 440, oil cylinder 450, inner die head 460;

[0031] Clamping trolley 500;

[0032] Centering mechanism 600, fixed frame 610, trapezoidal ring body 620, floating roller 630, elastic member 640;

[0033] Feeding device 700, pipe transfer mechanism 800, pipe receiving frame 900.

Detailed implementation manners

[0034] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings of the embodiments of the present invention. However, the following embodiments are only the preferred embodiments of the present invention and not all of them. Based on the embodiments in the implementation manners, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is 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 thus cannot be understood as a limitation to the present invention.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0039] Embodiment 1

[0040] Refer toFigures 1 to 6 , the present invention provides a pipe stretching machine, which includes a frame 100. A conveying device 200 and a flipping device 300 are provided on the frame 100. A stretching die base 400 and a clamping trolley 500 for clamping pipes are provided below the frame 100 and under the conveying device 200. The flipping device 300 can change the position of the pipe conveyed by the conveying device 200 in the vertical direction and convey the pipe below the conveying device 200. The stretching die base 400 is located between the clamping trolley 500 and the flipping device 300. The clamping trolley 500 is slidably engaged with the frame 100 to drag the pipe to move and complete the pipe stretching. The stretched pipe is discharged from the side of the pipe stretching machine.

[0041] The frame 100 can be divided into two layers. The pipe can be conveyed on the upper layer or the lower layer. When the pipe is conveyed on the upper layer, it is driven by the conveying device 200 and moves towards the flipping device 300. The flipping device 300 can change the position of the pipe and transfer the pipe from the upper layer to the lower layer, so that it can be conveyed on the lower layer of the frame 100. During the conveying on the lower layer, the pipe first passes through the stretching die base 400 to complete the stretching of the end. After the end of the pipe exposes from the stretching die base 400, the clamping trolley 500 can clamp the pipe. As the clamping trolley 500 moves, it can pull the pipe to move. At the same time, the conveying device 200 above can convey the pipe while the pipe is being pulled below. The conveying of the pipe and the stretching of the pipe can be carried out at the same position but at different heights, which shortens the length of the equipment and completes the subsequent pipe drawing process. The drawn pipe is discharged from the side of the equipment. Therefore, there is no need to leave a space in the length direction of the equipment to accommodate the stretched pipe.

[0042] Refer to Figure 5 , wherein, the stretching die base 400 can complete the stretching and peeling of the pipe. Specifically, the stretching die base 400 includes a die base 410, a stretching die 420 and a peeling die 430 provided on the die base 410. After the pipe passes through the stretching die 420, it can complete the stretching. When passing through the peeling die 430, it can complete the peeling. In addition, the conveying device 200 on the stretching die base 400 can convey the pipe at the same time. The conveying of the pipe and the stretching and peeling of the pipe can be carried out simultaneously at different height positions on the frame 100.

[0043] During the peeling process, a lot of waste materials will be generated, and these waste materials need to be discharged. There needs to be a gap between the peeling die 430 and the stretching die 420 to facilitate the discharge of the waste materials. Therefore, the stretching die holder 400 further includes a movable template 440. The movable template 440 can move relative to the die holder 410. The peeling die 430 is arranged on the movable template 440. Two oil cylinders 450 are provided on the die holder 410. The push rods on the oil cylinders 450 are connected to the movable template 440, so as to control the movement of the movable template 440. The movable template 440 can drive the peeling die 430 to move during the stretching process, changing its position relative to the die holder 410, generating a gap between the stretching die 420 and the peeling die 430. Moreover, after the pipe passes through the stretching die 420, the movable template 440 can also move towards the pipe, so that the movable template 440 can extrude the pipe, and the pipe can pass through the peeling die 430, avoiding the situation that peeling cannot be completed due to insufficient driving force of the flipping device 300 on the pipe; the clamping trolley 500 can also quickly clamp this section of the peeled pipe for subsequent stretching and peeling. The displacement of the clamping trolley 500 on the frame 100 is controlled by a reciprocating motor (not shown in the figure). The reciprocating motor is arranged at the end of the frame 100 far from the flipping device 300 and is relatively close to the clamping trolley 500, which is convenient for controlling the clamping trolley 500.

[0044] Embodiment 2

[0045] This embodiment specifically illustrates the specific structure of the conveying device 200. Specifically: Referring to Figure 1 and 3 , the conveying device 200 includes multiple pairs of spaced support frames 210. The support frames 210 are provided with first rollers 220 and first motors 230 for driving the first rollers 220 to roll. The support frames 210 are arranged on both sides of the frame 100. The first rollers 220 are arranged between each pair of support frames 210 and are located above the clamping trolley 500, that is, on the upper layer of the frame 100. The movement of the pipe on the upper layer of the frame 100 is realized through the transmission device. Under the action of the gravity of the pipe itself, there will be a certain amount of friction between the pipe and the first rollers 220. With the driving of the first motor 230 on the first rollers 220, the first rollers 220 can push the pipe to move continuously while rotating. Multiple pairs of support frames 210 can support the pipe extremely well, enabling the pipe to remain stable during the conveying process.

[0046] There is only one first motor 230, which is arranged at one end close to the stretching die holder 400 and can drive two first rollers 220 to rotate simultaneously. The remaining first rollers 220 only play a supporting role and can rotate relative to the support frames 210, reducing the influence of friction on the transmission of the pipe.

[0047] In addition, the conveying device 200 further includes a clamping member 240 disposed on the support frame 210 for clamping the pipe. The clamping member 240 includes a second roller 241 and a lifting cylinder 242 for controlling the lifting of the second roller 241. There are two clamping members 240, which are respectively disposed above the first roller 220 controlled by the first motor 230. Under the action of the lifting cylinder 242, the second roller 241 can clamp the pipe between the first roller 220 and the second roller 241, thereby increasing the friction during transmission and keeping the pipe stable. The second roller 241 can also rotate relative to the support frame 210, so that there is no slipping during the conveying process.

[0048] Embodiment III

[0049] This embodiment specifically illustrates the specific structure of the flipping device 300. Specifically: Refer to Figure 4 , the flipping device 300 includes a flipping disk 310 and a second motor 320 for driving the flipping disk 310 to rotate. There are two sleeves 330 on the flipping disk 310 and a first core rod 340 accommodated in the sleeves 330. The pipe can be sleeved outside the first core rod 340 and accommodated in the sleeves 330. The flipping disk 310 can rotate 180° under the action of

[0050] the second motor 320. While rotating, it can drive the sleeves 330, the first core rod 340 and the pipe sleeved outside the first core rod 340 to rotate synchronously, change the vertical position of the pipe, realize the replacement of the upper and lower positions. After the replacement is completed, the conveying device 200 can transfer the pipe into the upper sleeve 330 again.

[0051] In order to enable the flipping device 300 to convey the pipe to the stretching die holder 400, a second core rod 350 connected to the first core rod 340 is further provided inside the sleeve 330. The diameter of the second core rod 350 is larger than the diameter of the pipe. A driving member (not marked in the figure) for driving the second core rod 350 to move is also provided on the flipping disk 310. Since the diameter of the second core rod 350 is larger, when the driving member pushes the second core rod 350 to move, the second core rod 350 can push the first core rod 340 and the pipe wrapped outside the first core rod 340 to move and push it towards the stretching die holder 400 for stretching the pipe.

[0052] Embodiment IV

[0053] This embodiment proposes an adjusting assembly 360 on the basis of the above embodiment. Specifically: Refer to Figures 3 to 5, Tube stretching requires an outer die and an inner die. The two work together to complete the stretching of the tube. The outer die is the stretching die 420 on the stretching die holder 400, and the inner die is the inner die head 460 provided at the end of the first core rod 340. When the tube moves towards the flipping device 300 under the action of the conveying device 200, it will pass through the inner die head 460 and then sleeve on the outside of the first core rod 340. Subsequently, after the up-and-down position replacement by the flipping device 300, the second core rod 350 pushes the first core rod 340 and the tube sleeved on the first core rod 340 to move. The inner die head 460 enters into the stretching die 420, and the tube is squeezed between the inner die head 460 and the stretching die 420. As the clamping trolley 500 moves, it pulls the tube to continuously pass through between the inner die head 460 and the stretching die 420, thus completing the stretching of the tube.

[0054] When the conveying device 200 conveys the tube to the first core rod 340, part of the tube will protrude from the end of the first core rod 340. When the inner die head 460 enters into the stretching die 420, this part of the tube is already outside the stretching die 420. The clamping trolley 500 can clamp this section of the tube and start the stretching operation of the tube.

[0055] Since the stroke of the driving part remains unchanged, the displacement of the second core rod 350 and the first core rod 340 will not change. However, there needs to be a certain distance between the inner die and the outer die to achieve normal processing. But during long-term use, the distance between the inner die head 460 and the stretching die holder 400 will change, and the distance between the two may not be the optimal distance during the initial use. Therefore, an adjusting component 360 is provided on the flipping disc 310 to change the position of the second core rod 350 in the axial direction, thereby changing the overall position of the first core rod 340 and the second core rod 350, and ensuring normal processing and the quality of the product.

[0056] The adjusting component 360 is provided on the flipping disc 310 and includes two symmetrically arranged adjusting motors 361. An adjusting sleeve 362 cooperating with the second core rod 350 is provided on the flipping disc 310. During operation, the adjusting motor 361 can change the position of the second core rod 350 in the adjusting sleeve 362, thereby changing the positions of the first core rod 340 and the second core rod 350. The two adjusting motors 361 can respectively adjust the second core rod 350 at different positions.

[0057] Embodiment Five

[0058] Refer to Figure 3, in this embodiment, a centering mechanism 600 is added on the basis of Embodiment Four. When the pipe is driven on the conveying device, it needs to be aligned with the inner die head 460 of the first core rod 340 to be sleeved on the outside of the first core rod 340 to facilitate subsequent stretching operations. The centering mechanism 600 can guide the pipe to be conveyed towards the first core rod 340. The specific implementation method is as follows: A fixed frame 610 is provided on the frame 100, and a trapezoidal ring body 620 is provided on the fixed frame 610. The diameters on both sides of it are different, and the diameter on the side close to the conveying device 200 is larger to facilitate the pipe to enter the trapezoidal ring body 620. The first core rod 340 also enters the trapezoidal ring body 620 under the action of the driving member, thereby shortening the distance between the pipe and the inner die head 460 and facilitating the transmission of the pipe.

[0059] In addition, in order to ensure that the first core rod 340 is located at the center of the circle of the trapezoidal ring body 620, there is also a pair of floating rollers 630 on the fixed frame 610. The floating rollers 630 are connected to the fixed frame 610 through elastic members 640 and have the ability to float up and down. They can clamp the first core rod 340 and keep it at the center of the circle of the trapezoidal ring body 620 through the action of the elastic members 640.

[0060] Embodiment Six

[0061] Referring to Figure 7 , this embodiment also proposes a stretching unit, including a feeding device 700 and two of the above-mentioned pipe stretching machines. The feeding device 700 and the two pipe stretching machines are arranged side by side, and a pipe transfer mechanism 800 is provided between the two pipe stretching machines to realize the side transfer of the pipe on the equipment.

[0062] The feeding device 700 can transfer the pipe at the side of the stretching machine and convey the pipe to the conveying device 200. The pipes can also be transferred between the two stretching machines through the pipe transfer mechanism 800. After the pipe is subjected to the first stretching, under the action of the pipe transfer mechanism 800, it is transferred to the conveying device of the second stretching machine to start the second stretching. Under the combined action of the three, the pipe can be transferred on the side of the equipment, thereby shortening the length of the pipe secondary stretching unit.

[0063] In addition, the stretching unit further includes a pipe collecting frame 900. The pipe collecting frame 900 is located at the side of the second stretching machine. After the first stretching of the pipe by the first stretching machine, the pipe drops to be transferred by the pipe transfer mechanism 800. After the second stretching of the pipe by the second stretching machine, the pipe drops into the pipe collecting frame 900 to complete the collection of the pipe, facilitating subsequent transfer and processing.

[0064] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the content described in the drawings and the above specific implementation manner. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A pipe stretching machine, characterized in that: it includes a frame, on which a conveying device and a flipping device are provided. Below the conveying device on the frame, there is a stretching die seat and a clamping trolley for clamping the pipe. The flipping device can change the position of the pipe conveyed by the conveying device in the vertical direction and convey the pipe below the conveying device. The stretching die seat is located between the clamping trolley and the flipping device. The clamping trolley is slidably matched with the frame to drag the pipe to move to complete the pipe stretching. The stretched pipe is discharged from the side of the pipe stretching machine; the flipping device includes a flipping disc and a second motor for driving the flipping disc to rotate. On the flipping disc, there is a sleeve and a first core rod accommodated in the sleeve. The pipe is sleeved outside the first core rod and accommodated in the sleeve; the sleeve also internally has a second core rod connected to the first core rod. The diameter of the second core rod is larger than the diameter of the pipe. The flipping disc is also provided with a driving member for driving the second core rod to move; a fixed frame is arranged on the frame. On the fixed frame, there is a trapezoidal ring body, with a larger diameter on the side closer to the conveying device. The first core rod also enters into the trapezoidal ring body under the action of the driving member. There are also a pair of floating rollers on the fixed frame. The floating rollers are connected to the fixed frame through elastic members and have the ability to float up and down, and can clamp the first core rod and keep it at the center position of the trapezoidal ring body through the action of the elastic members; the end of the first core rod is provided with an inner die head. The flipping disc is also provided with an adjusting component for adjusting the distance between the inner die head and the stretching die seat. The adjusting component is arranged on the flipping disc and includes two symmetrically arranged adjusting motors. On the flipping disc, there is an adjusting sleeve shell cooperating with the second core rod. During the operation of the adjusting motors, the position of the second core rod in the adjusting sleeve shell is changed, thereby changing the positions of the first core rod and the second core rod. The two adjusting motors respectively adjust the second core rods at different positions.

2. A pipe stretching machine according to claim 1, characterized in that: the stretching die seat includes a die seat and a stretching die and a peeling die arranged on the die seat.

3. A pipe stretching machine according to claim 2, characterized in that: the stretching die seat further includes a movable template, and the movable template can move relative to the die seat. The peeling die is arranged on the movable template.

4. A pipe stretching machine according to claim 1, characterized in that: the conveying device includes multiple pairs of spaced-apart support frames. On the support frames, there are first rollers and a first motor for driving the first rollers to roll.

5. A pipe stretching machine according to claim 4, characterized in that: the conveying device further includes a clamping component for clamping the pipe arranged on the support frames.

6. A pipe stretching machine according to claim 5, characterized in that: the clamping component includes second rollers and a lifting cylinder for controlling the lifting of the second rollers.

7. A stretching unit, characterized in that: It includes a feeding device and two of the pipe stretching machines as described in any one of the above claims 1 to 6. The feeding device and the two pipe stretching machines are arranged side by side, and a pipe transfer mechanism is provided between the two pipe stretching machines to realize the transfer of the pipe at the side of the pipe stretching machine.

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