CN111957807A

CN111957807A - Integrated forming pipe bending device for bulging bent pipe

Info

Publication number: CN111957807A
Application number: CN202011151727.1A
Authority: CN
Inventors: 张峰; 陈怡江; 刘�文; 张池; 王春鸽; 郑浩民; 王沛超; 滕叶莹; 林立; 应祺辉
Original assignee: Zhejiang University of Science and Technology ZUST
Current assignee: Zhejiang University of Science and Technology ZUST
Priority date: 2020-10-26
Filing date: 2020-10-26
Publication date: 2020-11-20
Anticipated expiration: 2040-10-26
Also published as: CN111957807B

Abstract

The invention discloses an integrated forming pipe bending device for an expanded bent pipe, which comprises a die set, a pipe bending mechanism, a hydraulic system and sealing mechanisms arranged at two ends of the die set, wherein the die set is provided with a plurality of sealing grooves; the die set is used for clamping and bulging the pipe to be processed, and the hydraulic system provides bulging internal pressure for the pipe to be processed; the die set comprises a first die and a second die which are oppositely arranged; the pipe bending mechanism comprises a rotatable bending arm, and the bending arm drives the first die and the second die to synchronously rotate when rotating; the second die is provided with a pipe bending groove, and the pipe bending groove acts on the pipe to bend the pipe along with the rotation of the second die; the sealing mechanism comprises a plug for plugging the end part of the pipe, and when the pipe is bent, the plug moves synchronously along with the movement of the end part of the pipe. The invention realizes the double actions of bulging and bending on one device, thereby realizing resource sharing and improving production efficiency; the bent pipe manufactured by the invention shortens the manufacturing period and has high yield.

Description

Integrated forming pipe bending device for bulging bent pipe

Technical Field

The invention relates to the technical field of bulging pipe manufacturing, in particular to an integrated forming pipe bending device for a bulging bent pipe.

Background

In practical application, the expanded pipe generally needs to be bent and processed into a bent pipe with certain curvature so as to meet the use requirement. At present, a forming device and a pipe bending device (automatic or manual) are needed to be used for respectively realizing two actions of bulging and bending of a pipe to be processed in the bulging bent pipe manufacturing process, the two actions are unrelated, the devices for realizing the two actions are mutually independent, the effect of sharing resources cannot be achieved, the labor production efficiency is low, and the resource waste is serious. In addition, if two actions of bulging and bending are respectively performed on two different devices, after the bulging process is finished, one tube must be transferred, and the tube needs to be additionally taken and placed once when being transferred from the bulging device to the bending device, namely, the tube is taken from a clamping device of the bulging device and then assembled on a clamping device of the bending device, and the two actions not only need a certain time to be completed, but also risk that the tube is damaged in the transferring process. Therefore, there is a need to develop an integrated apparatus for forming a bent pipe from a pipe, so that the pipe can be expanded and bent on one apparatus, thereby achieving resource sharing and improving production efficiency.

Disclosure of Invention

The invention aims to provide an integrated forming pipe bending device for an expanded bent pipe. The invention realizes double actions of bulging and bending on one device, thereby realizing the purposes of resource sharing and improving the production efficiency; the bent pipe manufactured by the invention can shorten the manufacturing period and has higher yield.

The technical scheme of the invention is as follows: an integrated forming pipe bending device for an expanded bent pipe comprises a die set, a pipe bending mechanism, a hydraulic system and sealing mechanisms arranged at two ends of the die set; the die set is used for clamping and bulging the pipe to be processed, and the hydraulic system provides bulging internal pressure for the pipe to be processed; the die set comprises a first die and a second die which are oppositely arranged; the pipe bending mechanism comprises a rotatable bending arm, and the bending arm drives the first die and the second die to synchronously rotate when rotating; the second die is provided with a pipe bending groove, and the pipe bending groove acts on the pipe to bend the pipe along with the rotation of the second die; the sealing mechanism comprises a plug for plugging the end part of the pipe, and when the pipe is bent, the plug moves synchronously along with the movement of the end part of the pipe.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the die set, the pipe bending mechanism, the hydraulic system and the sealing mechanism are arranged to integrate two actions of bulging and pipe bending into the same device, and the two actions of bulging and pipe bending are completed on one device, and no transfer action of pipes is required between the two actions, so that the production cycle of the pipe bending is greatly shortened, and the production efficiency is high; specifically, the die set is used for clamping and bulging a pipe to be machined, meanwhile, a first die and a second die in the die set are mounted on a rotatable bending arm and can be simultaneously used as a part of a pipe bending mechanism to participate in pipe bending actions, furthermore, a pipe bending groove is formed in the second die, the pipe bending groove acts on the pipe to bend the pipe along with the rotation of the second die, and the die set designed by the invention participates in the bulging actions and the pipe bending actions together in the whole manufacturing process of the pipe bending, so that resource sharing is realized.

In addition, because the bulging action and the pipe bending action are integrated on the same device, after the bulging action is finished, the pipe does not need to be taken down from the clamping device of the bulging equipment and then assembled on the clamping device of the bending equipment, so that the intermediate step is reduced, which means that the pipe does not need to bear the possible damage risk in the transfer process; furthermore, the liquid in the pipe does not need to be removed after the pipe is expanded, the liquid can also participate in the bending action of the pipe to provide supporting force for the inner wall of the pipe, the pipe can be effectively prevented from collapsing and wrinkling in the bending process, the produced bent pipe is higher in quality, and the yield is higher; the liquid in the hydraulic system not only participates in the bulging action, but also participates in the bending action, and the resource sharing is realized.

In the integrated forming pipe bending device for the bulging bent pipe, the first die and the second die form a section of bulging die path after die assembly, a third die and a fourth die which are arranged oppositely are arranged on the same side of the first die and the second die, and the third die and the fourth die form a section of straight pipe die path connected with the bulging die path after die assembly.

In the integral type shaping swan neck system of bloated shape return bend, the center of rotation of crooked arm with the second mould is the same, the pipe bending groove on the second mould is half circular arc, one side embedding of fourth mould the pipe bending inslot.

In the integrated forming pipe bending device for the bulging bent pipe, the bending arm is provided with a sliding groove, the bottom of the first mold is embedded into the sliding groove, and the first mold can be horizontally moved along the sliding groove to realize mold closing and mold splitting with the second mold.

In the integral type shaping swan neck system of the bulging return bend of the aforesaid, first mould is connected with first pneumatic cylinder, the third mould is connected with the second pneumatic cylinder, first pneumatic cylinder set up in on the bending arm.

In the integral type shaping swan neck system of the bulging return bend, the return bend mechanism still includes drive crooked arm pivoted pivot, be equipped with the gear in the pivot, gear connection has the rack, rack connection has the third pneumatic cylinder.

In the integral type shaping swan neck system of aforementioned bulging return bend, the end cap includes the push rod, the one end of push rod is equipped with the taper block, and the other end is connected with the fourth pneumatic cylinder, the inside cavity section that communicates with taper block place end that is equipped with of push rod, the outside cover of taper block is equipped with the rubber circle, the rubber circle with still be equipped with four claw pieces between the taper block, the end side of rubber circle is equipped with the baffle, one side of baffle is equipped with the ejector pin, the ejector pin is connected with the fifth pneumatic cylinder.

In the integral type shaping swan neck system of bulging return bend, the rubber circle with the push rod outside that the baffle corresponds is equipped with the draw-in groove, the rubber circle with in the baffle all imbeds the draw-in groove.

In the integral type shaping swan neck system of bulging return bend, the push rod outside is equipped with and inserts and communicate the hydraulic pressure coupling of the inside cavity section of push rod from the push rod lateral wall, hydraulic pressure coupling has the high pressure self priming pump through hydraulic pressure union coupling, the high pressure self priming pump is connected with the water tank.

In the integral type shaping swan neck system of the bulging swan neck, still include the frame, die set, swan neck mechanism, hydraulic system and sealing mechanism all set up in on the frame.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a schematic structural view from another perspective of the present invention;

FIG. 4 is a schematic structural view of a sealing mechanism;

fig. 5 is a sectional view of the internal structure of the sealing mechanism;

FIG. 6 is an enlarged view of a portion of FIG. 5 at B;

FIG. 7 is a schematic structural view of the tube bending mechanism;

FIG. 8 is a schematic view of the structure of the flexure arm;

FIG. 9 is a schematic structural view of a second mold;

fig. 10 is a partial enlarged view of fig. 6 at C.

Reference numerals: 11-a first die, 12-a second die, 13-an expanding die way, 14-a third die, 15-a fourth die, 16-a straight tube die way, 17-a first hydraulic cylinder, 18-a second hydraulic cylinder, 21-a bending arm, 22-a rotating shaft, 23-a gear, 24-a rack, 25-a third hydraulic cylinder, 30-a choke plug, 31-a push rod, 32-a cone block, 33-a fourth hydraulic cylinder, 34-a rubber ring, 35-a four-jaw block, 36-a baffle, 37-a push rod, 38-a fifth hydraulic cylinder, 41-a hydraulic pipe joint, 42-a hydraulic pipe, 43-a self-priming pump, 44-a water tank, 51-a frame, 121-a bending pipe groove, 211-a sliding groove, 311-a clamping groove, 342-a convex ring and 343-a ring groove, 344-connecting edge, 345-upper cavity, 346-lower cavity, 347-side cavity.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.

Example (b): an integral forming pipe bending device for an expanded bent pipe is structurally shown in figures 1 to 3 and comprises a die set, a pipe bending mechanism, a hydraulic system and sealing mechanisms arranged at two ends of the die set; the die set is used for clamping and bulging the pipe to be processed, and the hydraulic system provides bulging internal pressure for the pipe to be processed; the die set comprises a first die 11 and a second die 12 which are oppositely arranged; the pipe bending mechanism structure is shown in fig. 7 and 8, and comprises a rotatable bending arm 21, the bending arm 21 is integrally in an L shape, the transverse and vertical intersection point of the L shape is the rotation point of the bending arm, and the bending arm 21 drives the first die 11 and the second die 12 to synchronously rotate when rotating; the second die 12 is provided with a pipe bending groove 121, and the structure is as shown in fig. 9, and the pipe bending groove 121 acts on the pipe to bend the pipe along with the rotation of the second die 12; the sealing mechanism comprises a plug 30 for plugging the end part of the pipe, and when the pipe is bent, the plug 30 moves synchronously along with the movement of the end part of the pipe.

Further, a section of bulging die channel 13 is formed after the first die 11 and the second die 12 are closed, that is, the required molding shape of the product is obtained, a third die 14 and a fourth die 15 which are oppositely arranged are arranged on the same side of the first die 11 and the second die 12, the third die 14 and the fourth die 15 are respectively adjacent to and closely attached to the first die 11 and the second die 12, and a section of straight tube die channel 16 connected with the bulging die channel 13 is formed after the third die 14 and the fourth die 15 are closed, so that the overall continuity of the die channels is ensured.

Further, the bending arm 21 and the second die 12 have the same rotation center, the pipe bending groove 121 on the second die 12 is in a semi-circular arc shape, and one side of the fourth die 15 is embedded into the pipe bending groove 121, so that the main die path can always keep good continuity when the bending action is performed.

Further, the bending arm 21 is provided with a sliding groove 211, and the bottom of the first mold 11 is embedded in the sliding groove 211 and can be translated along the sliding groove 211 to realize mold closing and mold splitting with the second mold 12.

Furthermore, the first die 11 is connected with a first hydraulic cylinder 17, the third die 14 is connected with a second hydraulic cylinder 18, the first hydraulic cylinder 17 is arranged on the bending arm 21, and the first hydraulic cylinder 17 and the second hydraulic cylinder 18 respectively drive the first die 11 and the third die 14 to realize die closing and die separating actions.

Further, the pipe bending mechanism further comprises a rotating shaft 22 for driving the bending arm 21 to rotate, the rotating shaft 22 and the bending arm 21 keep relatively static in the movement process, preferably, a shaft hole matched with the rotating shaft 22 can be formed in the bending arm 21, the rotating shaft 22 and the rotating shaft 22 keep relatively static when rotation is achieved, a gear 23 is arranged on the rotating shaft 22, the gear 23 is connected with a rack 24, the rack 24 is connected with a third hydraulic cylinder 25, the rack 24 is driven by the third hydraulic cylinder 25 to move, and the rack 24 is meshed with the gear 23, so that the bending arm 21 is driven to rotate.

The top of the rotating shaft 22 of the invention is arranged higher than the top of the bending arm 21, the second die 12 can be provided with the same shaft hole and sleeved on the rotating shaft 22, and the top of the second die 12 is provided with a clamping nut, so that the second die 12 can keep coaxial synchronous rotation with the bending arm 21.

Further, the sealing mechanism comprises a plug 30 and a support for supporting the plug 30, the structure is shown in fig. 4 to 6, the plug 30 comprises a push rod 31, one end of the push rod 31 is provided with a conical block 32, the conical block 32 gradually decreases from the outer cross-sectional area to the inner cross-sectional area, the other end of the conical block 32 is connected with a fourth hydraulic cylinder 33, a hollow section communicated with the end where the conical block 32 is located is arranged inside the push rod 31, the outer side of the conical block 32 is sleeved with a rubber ring 34, a four-claw block 35 is further arranged between the rubber ring 34 and the conical block 32, the tail end side of the rubber ring 34 is provided with a baffle plate 36, one side of the baffle plate 36 is provided with a push rod 37, and the push; when sealing is carried out, the fourth hydraulic cylinder 33 drives the push rod 31 to push the rubber ring 34 into the pipe, at the moment, the baffle plate 36 covers the end opening of the pipe, the fifth hydraulic cylinder 38 drives the ejector rod 37 to prop against the baffle plate 36, the fourth hydraulic cylinder 33 drives the push rod 31 to contract, the conical block at the top of the push rod 31 acts on the four-jaw block 35, the four-jaw block 35 acts on the rubber ring 34, the rubber ring 34 expands radially, and the expanded rubber ring 34 forms bionic friction sealing at two ends of the pipe.

Further, the outer circumferential surface of the rubber ring 34 is configured as shown in fig. 10, the outer circumferential surface of the rubber ring 34 is provided with a plurality of convex rings 342, the convex rings 342 are arranged at intervals along the radial direction, a ring groove 343 is formed between two adjacent convex rings 342, and the convex rings 342 are arranged in an inclined manner towards the direction of the baffle plate 36. The convex rings 342 are provided with an upper layer cavity 345 and a lower layer cavity 346, a connecting edge 344 is obliquely arranged between two adjacent convex rings 342, side cavities 347 are formed between the two adjacent convex rings 342, the connecting edge 344 and the rubber ring 34 in a matching manner, and the cross sections of the upper layer cavity 345, the lower layer cavity 346 and the side cavities 347 are all wedge-shaped, so that the convex rings 342 are easy to deform.

Because the inside undulant pressure that receives of tubular product, undulant pressure change is great moreover, if directly sealed through rubber circle 34, undulant power can transmit to rubber circle 34, and rubber circle 34 can receive undulant axial force, can promote rubber circle 34 and remove, influences sealed effect, can cause rubber circle 34 to take place to warp moreover, influences sealed effect.

According to the invention, the ejector rod 37 and the fifth hydraulic cylinder 38 are arranged, so that axial thrust can be generated on the rubber ring 34, the rubber ring 34 is kept balanced with axial power generated by fluctuation in a pipe, the rubber ring 34 is prevented from moving, the easily-deformable convex ring 342 is arranged on the periphery of the rubber ring 34, so that the convex ring 342 can be tightly attached to the inner wall of the pipe, the convex ring 342 is obliquely arranged and can be tightly abutted against the inner wall of the pipe conveniently, after the rubber ring 34 is subjected to axial action, when the rubber ring 34 deforms, the convex ring 342 can still be tightly attached to the inner wall of the pipe, the contact area between the rubber ring 34 and the inner wall of the pipe is increased, good sealing performance is ensured, and the adjacent two convex rings 342 are arranged at intervals, so that the annular groove 343 is formed between the two adjacent convex rings 342, the annular groove 343 can play a storage role, when water leaks from the pipe, the leaked water can be stored through the annular, the water is prevented from leaking to the outside to ensure the sealing effect of the rubber ring 34. The upper layer cavity 345, the lower layer cavity 346 and the side cavity 347 are distributed in a honeycomb shape, so that after the convex ring 342 deforms, the convex ring 342 can generate a large reaction force, the convex ring 342 can be always in tight contact with the inner wall of the pipe, and after the rubber ring 34 receives the axial action force fluctuating in the pipe, the convex ring 342 can still be in tight contact with the inner wall of the pipe, so that the sealing requirement can be met.

Further, the rubber ring 34 and the push rod 31 outer side corresponding to the baffle 36 are provided with a clamping groove 311, the rubber ring 34 and the baffle 36 are all embedded into the clamping groove 311, when the rubber ring 34 is pushed into the pipe, the end opening of the pipe covered by the baffle 36 is used as a position determination point, and the tail end of the clamping groove 311 is the limit movement position of the baffle 36.

Further, the outside of push rod 31 is equipped with and inserts and communicate the hydraulic pressure coupling 41 of the inside hollow section of push rod 31 from the push rod 31 lateral wall, and hydraulic pressure coupling 41 and push rod 31 lateral wall threaded connection, hydraulic pressure coupling 41 is connected with high pressure self priming pump 43 through hydraulic pressure pipe 42, high pressure self priming pump 43 is connected with water tank 44.

Further, the hydraulic pipe 42 is a flexible ultrahigh pressure hydraulic pipe 42, so that the hydraulic pipe 42 can deform and move within a small range in the pipe bending process, particularly, the hydraulic pipe 42 on the side where the third die 14 and the fourth die 15 are located is slightly reduced in axial length when the pipe is bent, and the fourth hydraulic cylinder 33 and the fifth hydraulic cylinder 38 on the side need to simultaneously drive the push rod 31 and the ejector rod 37 to move to compensate the reduction in axial length of the pipe; here, it should be noted that although the sealing mechanism structures at the two ends of the die set of the present invention are the same, since the sealing mechanisms on the sides of the first die 11 and the second die 12 are also mounted on the bending arm 21, the sealing mechanisms can synchronously rotate along with the first die 11 and the second die 12, and the fourth hydraulic cylinder 33 and the fifth hydraulic cylinder 38 on the sides are not required to be operated when the pipe is bent.

Further, the device of the present invention further includes a frame 51, and the mold set, the tube bending mechanism, the hydraulic system and the sealing mechanism are all disposed on the frame 51, wherein the hydraulic system is located at the bottom end of the frame 51.

The process for manufacturing the bulging bent pipe comprises the following process steps:

step one, pipe material loading: placing a pipe to be processed into a second die 12 and a fourth die 15, driving a first die 11 to realize die assembly with the second die 12 by a first hydraulic cylinder 17, and driving a third die 14 to realize die assembly with the fourth die 15 by a second hydraulic cylinder 18, so that the pipe to be processed is clamped;

step two, sealing the pipe: a fourth hydraulic cylinder 33 of the sealing mechanism at the two ends of the die set drives a push rod 31 to push the rubber ring 34 into the pipe, a fifth hydraulic cylinder 38 drives a push rod 37 to prop against a baffle 36, the fourth hydraulic cylinder 33 drives the push rod 31 to contract, so that a conical block at the top of the push rod 31 acts on a four-jaw block 35, and the four-jaw block 35 expands the rubber ring 34 to form sealing at the two ends of the pipe;

step three, internal high-pressure bulging: the hydraulic system works to press liquid into the pipe and perform high-pressure bulging on the pipe corresponding to the bulging die channel 13;

step four, inner low-pressure bending: after the bulging is finished, the hydraulic system is controlled to reduce the internal pressure to be below the plastic deformation pressure of the pipe, the hydraulic rod of the third hydraulic cylinder 25 extends to drive the rack 24 to move, the rack 24 is meshed with the gear 23 to drive the bending arm 21 to rotate to bend the pipe subjected to the bulging, a finished bent pipe is obtained, after the bulging action is finished, the liquid in the pipe does not need to be removed, the liquid can participate in the bending action of the pipe to provide supporting force for the inner wall of the pipe, the pipe can be effectively prevented from collapsing and wrinkling in the bending process, and the quality of the produced bent pipe is higher, namely the liquid in the hydraulic system not only participates in the bulging action, but also participates in the bending action, so that resource sharing is realized;

step five, blanking of the pipe: after the pipe bending is finished, the hydraulic system stops working, liquid in the pipe is removed, the fourth hydraulic cylinder 33 drives the push rod 31 to extend, the rubber ring 34 recovers, the fifth hydraulic cylinder 38 drives the ejector rod 37 to be away from the baffle 36, the fourth hydraulic cylinder 33 drives the push rod 31 to contract again, the push rod 31 and the rubber ring 34 are driven to be separated from the two ends of the finished bent pipe, the hydraulic rods of the first hydraulic cylinder 17 and the second hydraulic cylinder 18 contract to drive the first die 11 and the third die 14 to reset, the finished bent pipe is taken out, and the processing is finished.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and 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.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned examples, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. The utility model provides an integral type shaping swan neck system of bloated shape return bend which characterized in that: the pipe bending device comprises a die set, a pipe bending mechanism, a hydraulic system and sealing mechanisms arranged at two ends of the die set; the die set is used for clamping and bulging the pipe to be processed, and the hydraulic system provides bulging internal pressure for the pipe to be processed; the die set comprises a first die (11) and a second die (12) which are oppositely arranged; the pipe bending mechanism comprises a rotatable bending arm (21), and the bending arm (21) drives the first die (11) and the second die (12) to synchronously rotate when rotating; a pipe bending groove (121) is formed in the second die (12), and the pipe bending groove (121) acts on the pipe to bend the pipe along with the rotation of the second die (12); the sealing mechanism comprises a plug (30) for plugging the end of the pipe, and when the pipe is bent, the plug (30) moves synchronously along with the movement of the end of the pipe.

2. The integrally formed elbow unit of an expanded elbow according to claim 1, wherein: the first die (11) and the second die (12) form a section of bulging die channel (13) after die assembly, a third die (14) and a fourth die (15) which are oppositely arranged are arranged on the same side of the first die (11) and the second die (12), and a section of straight tube die channel (16) connected with the bulging die channel (13) is formed after die assembly of the third die (14) and the fourth die (15).

3. The integrally formed elbow unit for an expanded elbow according to claim 2, wherein: the bending arm (21) and the rotation center of the second die (12) are the same, a pipe bending groove (121) in the second die (12) is in a semi-circular arc shape, and one side of the fourth die (15) is embedded into the pipe bending groove (121).

4. The integrally formed elbow unit for an expanded elbow according to claim 2, wherein: the bending arm (21) is provided with a sliding groove (211), the bottom of the first mold (11) is embedded into the sliding groove (211), and the bottom of the first mold can be translated along the sliding groove (211) to realize mold closing and mold splitting with the second mold (12).

5. The integrally formed elbow unit for an expanded elbow according to claim 2, wherein: the first die (11) is connected with a first hydraulic cylinder (17), the third die (14) is connected with a second hydraulic cylinder (18), and the first hydraulic cylinder (17) is arranged on the bending arm (21).

6. The integrally formed elbow unit of an expanded elbow according to claim 1, wherein: the pipe bending mechanism further comprises a rotating shaft (22) for driving the bending arm (21) to rotate, a gear (23) is arranged on the rotating shaft (22), the gear (23) is connected with a rack (24), and the rack (24) is connected with a third hydraulic cylinder (25).

7. The integrally formed elbow device of an expanded elbow according to any one of claims 1-6, characterized in that: end cap (30) include push rod (31), the one end of push rod (31) is equipped with awl piece (32), and the other end is connected with fourth pneumatic cylinder (33), the inside cavity section that communicates with awl piece (32) place end that is equipped with of push rod (31), the outside cover of awl piece (32) is equipped with rubber circle (34), rubber circle (34) with still be equipped with four claw pieces (35) between awl piece (32), the end side of rubber circle (34) is equipped with baffle (36), one side of baffle (36) is equipped with ejector pin (37), ejector pin (37) are connected with fifth pneumatic cylinder (38).

8. The integrally formed elbow unit of an expanded elbow according to claim 7, wherein: the rubber ring (34) and the outer side of the push rod (31) corresponding to the baffle (36) are provided with clamping grooves (311), and the rubber ring (34) and the baffle (36) are embedded into the clamping grooves (311).

9. The integrally formed elbow unit of an expanded elbow according to claim 7, wherein: push rod (31) outside is equipped with and inserts and feed through hydraulic pressure coupling (41) of the inside hollow section of push rod (31) from push rod (31) lateral wall, hydraulic pressure coupling (41) are connected with high pressure self priming pump (43) through hydraulic pressure pipe (42), high pressure self priming pump (43) are connected with water tank (44).

10. The integrally formed elbow unit of an expanded elbow according to claim 1, wherein: the pipe bending machine is characterized by further comprising a frame (51), wherein the die set, the pipe bending mechanism, the hydraulic system and the sealing mechanism are all arranged on the frame (51).