CN217254067U

CN217254067U - Elbow welding and fixing device and pipe fitting machining device

Info

Publication number: CN217254067U
Application number: CN202220908375.8U
Authority: CN
Inventors: 何耀璐; 徐亚军; 陈家丽; 沈成; 马立武; 曹佳瑞; 杨林杰
Original assignee: Shanghai Aircraft Manufacturing Co Ltd
Current assignee: Shanghai Aircraft Manufacturing Co Ltd
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2022-08-23
Anticipated expiration: 2032-04-19

Abstract

The utility model belongs to the technical field of pipe fitting processing, and discloses an elbow welding and fixing device and a pipe fitting processing device, which comprises a first fixing component and a second fixing component, wherein two first fixing components are arranged at intervals in the circumferential direction around the rotation center of a rotating disc, the first fixing component is used for fixing a straight pipe, the second fixing component is arranged at the rotation center of a base, the second fixing component is used for fixing an elbow, the two straight pipe sections can be driven by the two first fixing components to rotate in the circumferential direction around the rotation center, the elbow is fixed at the rotation center through the second fixing component, and the angle between the straight line sections of the two pipe fittings can be adjusted through the relative rotation of the two first fixing components along with the different angles of the elbow to be welded so as to adapt to the welding of elbows with different angles, thereby solving the technical problem that the elbow welding device in the prior art can not adapt to the welding requirements of elbows with various angles, the work efficiency and the welding quality of elbow welding are improved.

Description

Elbow welding fixing device and pipe fitting processingequipment

Technical Field

The utility model relates to a pipe fitting processing technology field especially relates to an elbow welded fastening device and pipe fitting processingequipment.

Background

The pipe fitting is a part which plays roles of connection, control, turning, diversion, sealing, supporting and the like in a pipeline system, and is widely applied to various fields in life. To change the direction of the pipeline, it is often necessary to bend the pipe elements to achieve connection at the pipe bends.

The existing pipe bender is generally suitable for bending a pipe fitting with a larger outer diameter, and when parts with smaller outer diameter and wall thickness are processed, the parts are easy to crack and deform, so that the parts are scrapped, and the parts are generally welded by adopting an elbow welding process. The elbow welding process is that an elbow is welded between two straight pipe sections with different directions so as to change the direction of a pipeline. In the welding process, in order to avoid potential safety hazards caused by the bending and twisting and dislocation of the welding part, the elbow and the straight-line pipe fitting need to be fixed.

The elbow welding and fixing device in the prior art is generally provided with a workbench connected with a welding machine, and a support frame is arranged on the workbench and can place an elbow and a straight pipe section at a position suitable for welding. The elbow and the straight line section are pressed on the support frame through a clamping plate with an arc-shaped groove and are screwed and fixed through bolts. And after the elbow and the straight pipe section are welded, loosening the bolts on the clamping plates, and taking down the clamping plates to take down the welded pipe fittings.

The existing elbow welding fixing device can fix a straight pipe section and an elbow, but in actual production, the elbow used for butt welding often has various angles, such as a 45-degree elbow, a 135-degree elbow, a 90-degree elbow and the like. The existing elbow welding device is only suitable for elbow welding with a set angle due to the structural limitation of the support frame and the clamping plate. For butt welding of elbows at different angles, the existing elbow welding device has no universality, so that the elbow welding and fixing device has lower universality and higher use cost.

SUMMERY OF THE UTILITY MODEL

An aspect of the utility model is to provide an elbow welded fastening device and pipe fitting processingequipment to be applicable to the welding demand of the elbow of different angles, improve welded flexibility.

To achieve the purpose, the utility model adopts the following technical proposal:

an elbow weld fixture for fixing an elbow and two straight pipe sections to be welded at both ends of the elbow, the elbow weld fixture comprising:

the two first fixing assemblies can circumferentially rotate around a rotation center relative to each other, and are respectively used for fixing the two straight pipe sections;

and the second fixing component is arranged at the rotating center and used for fixing the elbow.

Optionally, the elbow welding fixture further comprises:

a base having a first support surface;

the rotating disc is rotatably connected with the base and provided with a second supporting surface, the first supporting surface and the second supporting surface are coplanar, and the first fixing assembly is arranged on each of the first supporting surface and the second supporting surface.

Optionally, the first fixing assembly comprises a baffle and a clamping unit, the clamping unit is opposite to the baffle and arranged at an interval so as to clamp the straight pipe section in a matched manner, and the distance between the clamping unit and the baffle can be adjusted;

and/or the second fixing assembly comprises positioning columns and pressing pieces which are opposite and arranged at intervals, the positioning columns are installed on the base, the pressing pieces and the positioning columns are matched to clamp the elbows, and the distance between the pressing pieces and the positioning columns can be adjusted.

Through above-mentioned scheme, baffle and the fixed straight tube section of centre gripping of clamping unit cooperation centre gripping, reference column and the cooperation centre gripping elbow that compresses tightly, when the elbow of multiple bore is welded to needs, can be through the distance between adjusting the baffle and the clamping unit and compress tightly the distance between piece and the reference column to the demand of the elbow of the multiple bore of adaptation centre gripping and straight tube section.

Optionally, the second fixing component further comprises a connecting rod and a locking nut, one end of the connecting rod is connected with the pressing part, the other end of the connecting rod is connected with the positioning column in a sliding mode, so that the pressing part is close to or far away from the positioning column, and the locking nut is screwed on the connecting rod in a threaded mode and is far away from one side of the pressing part in a butting mode through the positioning column.

And/or, the clamping unit comprises a fixing plate and an adjusting bolt, the fixing plate is opposite to the baffle plate and is arranged at intervals, the adjusting bolt is screwed on the fixing plate in a threaded manner, and the tail end of the adjusting bolt extends into the fixing plate and the baffle plate to abut against the straight pipe section. Through the scheme, utilize the connecting rod can be in the slip of reference column, make to compress tightly the piece and be close to or keep away from the reference column, the realization compresses tightly the adjustment of distance between piece and the reference column, adapt to the elbow of different bores, lock nut screws can drive the connecting rod and compress tightly the piece, make to compress tightly the piece and grasp the elbow with the reference column, utilize adjusting bolt and straight tube section butt, and fix the straight tube section between fixed plate and baffle, can adjust the distance between adjusting nut and the baffle through revolving adjusting nut soon, in order to use the straight tube section of different bores.

Optionally, the rotating disc is rotatably sleeved on the positioning column, and an axis of the positioning column is a rotation axis of the rotating disc.

Optionally, the positioning column is rotatably connected with the base, and a rotation axis of the positioning column is collinear with a rotation axis of the rotating disc.

Through above-mentioned scheme, the reference column can regard as the rotation axis to connect base and rotary disk, and the rotary disk can overlap on the reference column to rotatory with the axis position of reference column, it is rotatory to drive the first fixed subassembly on the rotary disk, adjusts the angle between two sets of first fixed subassemblies, in order to adapt to the welding of the elbow of different angles.

Optionally, an arc-shaped groove is formed in the rotating disc, the center of the arc-shaped groove is located on the rotating axis of the rotating disc, a threaded hole which is communicated with the arc-shaped groove in a facing manner is formed in the base, and the rotating disc and the base are fastened through a locking bolt which penetrates through the threaded hole and the arc-shaped groove;

and/or the rotating disc or the base is provided with angle scales, and the angle scales are used for indicating the rotating angle of the rotating disc.

Through the scheme, the locking bolt can be in threaded connection with the threaded hole in the base, the rotating disk is pressed and fixed, the arc-shaped groove with the circle center as the rotating axis of the rotating disk is formed in the rotating disk, the locking bolt can slide in the arc-shaped groove, the rotating disk is rotated as required, and when the angle of the first fixing component is adjusted on the rotating disk, the rotating disk can be rotated by unscrewing the locking bolt, so that the angle of the first fixing component is adjusted.

Optionally, the base includes a bottom plate portion and a boss portion protruding from the bottom plate portion, a surface of the boss portion away from the bottom plate portion forms the first supporting surface, and the rotating disc is rotatably mounted on the bottom plate portion.

Through the scheme, the rotary disc is installed on the bottom plate part, so that the second supporting surface on the rotary disc and the first supporting surface on the boss part can be on the same horizontal plane, and two straight-line-section pipe fittings and the elbow for welding are guaranteed to be fixed on the same horizontal plane.

Optionally, the boss portion and the rotating disc are of sector structures concentrically arranged, and a sum of a central angle corresponding to the boss portion and a central angle corresponding to the rotating disc is less than 360 °.

Through the scheme, the boss part and the rotating disc are of concentric fan-shaped structures, and the two side edges of the boss part can realize rotation limiting of the two sides of the rotating disc in a rotating mode.

According to the utility model discloses a still another aspect, the utility model provides a pipe fitting processingequipment, including above-mentioned elbow welded fastening device.

The utility model has the advantages that: the utility model provides an elbow welding fixing device and pipe fitting processingequipment, through fixing two straight tube sections respectively on two first fixed subassemblies, two first fixed subassemblies drive two straight tube sections and can wind the relative rotation in a circumferential direction each other of rotation center, the elbow is fixed in rotation center department through the fixed subassembly of second, along with treating the angle difference of welded elbow, can be through the relative rotation of two first fixed subassemblies, adjust the angle between two pipe fitting straightways, with the elbow welding that adapts to different angles, the technical problem of the welding demand of the elbow that elbow welding device can't adapt to multiple angle among the prior art has been solved, elbow welded work efficiency and welding quality have been improved.

Drawings

FIG. 1 is a schematic view of the fitting structure of the elbow welding fixture, the elbow and the straight pipe section provided by the present invention;

fig. 2 is a schematic structural view of the elbow welding and fixing device provided by the present invention;

fig. 3 is a schematic structural view of the elbow welding and fixing device provided by the present invention with the first fixing component removed.

In the figure: 100. a base; 110. a threaded hole; 120. a bottom plate portion; 130. a boss portion; 200. rotating the disc; 210. an arc-shaped slot; 220. locking the bolt; 300. a first fixed component; 310. a baffle plate; 320. a clamping unit; 321. a fixing plate; 322. adjusting the bolt; 400. a second fixed component; 410. a positioning column; 420. a pressing member; 430. a connecting rod; 440. and locking the nut.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element 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" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The utility model provides an elbow welding fixing device and pipe fitting processingequipment, mainly used realize elbow butt welding operation flow in the elbow fixed of elbow and straight tube section. When the elbow is welded, in order to prevent the elbow and the butt-welded straight pipe section from being twisted, shifted or misplaced, and the welded part from being twisted, deformed, concentrated in stress and even scrapped due to unsoldering, the elbow and the straight pipe section which are welded need to be clamped and fixed.

Fig. 1 is a schematic view of a fitting structure of an elbow welding and fixing device provided by the present invention, an elbow and a straight pipe section, fig. 3 is a schematic view of a structure of the elbow welding and fixing device provided by the present invention when a first fixing component is removed, as shown in fig. 1 and fig. 3, the elbow welding and fixing device provided by the present invention comprises a first fixing component 300, two first fixing components 300 can rotate circumferentially relative to each other around a rotation center, and the two first fixing components 300 are respectively used for fixing two straight pipe sections; and a second fixing member 400 installed at the rotation center, the second fixing member 400 being used to fix the elbow.

Further, the utility model provides an elbow welding set still includes base 100 and rotary disk 200, and base 100 has first holding surface, and rotary disk 200 rotates with base 100 to be connected, and rotary disk 200 has the second holding surface, and first holding surface and second holding surface coplane all are provided with first fixed subassembly 300 on first holding surface and the second holding surface.

Specifically, the first supporting surface and the second supporting surface are respectively provided with a first fixing component 300, and the first fixing component 300 can fix a straight pipe section to be welded. Between the two first stationary assemblies 300, i.e., at the rotation center of the rotating disk 200, a second stationary assembly 400 is installed, and the second stationary assembly 400 can fix the elbow. The two first fixing assemblies 300 are circumferentially arranged around the rotation center at intervals, so that the ends to be welded of the two fixed straight pipe sections are abutted to the two ends of the elbow pipe, and the fixing before welding is completed. The first fixing assembly 300 mounted on the rotating disc 200 can rotate with the rotating disc 200 on the base plate 100, and the angle between itself and another first fixing assembly 300 can be adjusted to be able to butt against the elbows of different bending angles.

The utility model provides an elbow welded fastening device and pipe fitting processingequipment, through fixing two straight tube sections respectively on two first fixed subassemblies 300, two first fixed subassemblies 300 drive two straight tube sections and can wind the relative rotation in a circumferential direction each other of rotation center, the elbow is fixed in rotation center department through the fixed subassembly 400 of second, along with treating the angle difference of welded elbow, can be through two first fixed subassemblies 300 relative rotation, adjust the angle between two pipe fitting straightways, in order to adapt to the elbow welding of different angles, the technical problem of the welding demand of the unable elbow that adapts to multiple angle of elbow welding device among the prior art has been solved, elbow welded work efficiency and welding quality have been improved.

After the angle of the elbow to be welded is determined, the rotating disc 200 is rotated to enable the angle between the first fixing component 300 on the rotating disc 200 and the first fixing component 300 on the bottom plate 100 to be consistent with the angle of the elbow, the elbow is fixed on the second fixing component 400, then the two straight pipe sections to be welded are respectively fixed on the first fixing component 300, the two straight pipe sections are respectively abutted against the two ends of the elbow, and the fixing of the elbow and the straight pipe sections before welding is completed.

That is, in the elbow welding fixture according to the present embodiment, the rotary disk 200 capable of rotating is provided on the base 100, the two first fixing members 300 for fixing the straight pipe sections are mounted on the rotary disk 200 and the base 100, the elbow is mounted on the rotation center of the rotary disk 200 through the second fixing member 400, and by rotating the rotary disk 200, the angle between the two straight pipe sections can be adjusted to adapt to the welding of elbows having different angles according to the difference in the angle of the elbow to be welded.

In order to improve the convenience of mounting the rotary plate 200, the base 100 includes a bottom plate portion 120 and a boss portion 130 protruding from the bottom plate portion 120, the boss portion 130 forms a first supporting surface away from the surface of the bottom plate portion 120, the rotary plate 200 is rotatably mounted on the bottom plate portion 120, and the thickness of the boss portion 130 is kept consistent with the thickness of the rotary plate 200. This arrangement enables the rotary disk 200 to be rotatably supported on the bottom plate 120 on the basis of ensuring the coplanarity of the first support surface and the second support surface, and is highly convenient to mount and highly stable in mounting.

More preferably, the boss portion 130 and the rotating disk 200 are concentrically arranged in a fan-shaped structure, the axis of the fan-shaped structure is located on the rotating axis of the rotating disk 200, and the sum of the central angle corresponding to the boss portion 130 and the central angle corresponding to the rotating disk 200 is less than 360 °. Therefore, the boss part 130 and the rotating disk 200 are arranged in a staggered manner in the circumferential direction of the rotating center, and the two side edges of the boss part 130 can limit the rotation of the rotating disk 200, so that the reliability of limiting the rotation of the rotating disk 200 is improved, and the overall appearance is improved.

The bottom plate part 120 is preferably a disc-shaped structure, the circle center of the disc-shaped structure and the circle center of the fan-shaped structure are concentrically arranged, and the outer diameter of the bottom plate part 120 is equal to that of the fan-shaped structure, so that the overall structure size of the elbow welding and fixing device is small, the edges are few, and the appearance attractiveness is strong. Further, the boss portion 130 and the bottom plate portion 120 are preferably integrally formed, and in other embodiments, they may be separately processed and connected by welding or detachable connection.

Fig. 2 is a schematic structural view of the elbow welding and fixing device provided by the present invention, as shown in fig. 2, a positioning column 410 is installed in the center of the base 100, and a through hole is opened in the sector center of the rotating disk 200, so that the rotating disk 200 can be sleeved on the positioning column 410 of the base 100, thereby ensuring that the rotating disk 200 can rotate on the base 100 by using the positioning column 410 as an axis. Preferably, the positioning column 410 is a metal cylinder, and a circular hole is formed in the center of the base 100, and the positioning column 410 can be inserted into the circular hole.

The second fixing assembly 400 can optionally comprise a pressing piece 410 and the positioning column 410, the pressing piece 420 and the positioning column 410 are arranged at intervals and matched with a clamping elbow, the distance between the pressing piece 420 and the positioning column 410 can be adjusted to adapt to elbows with different pipe diameters, and the clamping stability and the clamping convenience of the elbows are improved.

To more conveniently adjust the interval between the pressing member 420 and the positioning post 410, the second fixing assembly 400 further includes a connecting rod 430 and a lock nut 440. One end of the connecting rod 430 is connected with the pressing piece 420, the other end of the connecting rod 430 is connected with the positioning column 410 in a sliding mode, so that the pressing piece 420 is close to or away from the positioning column 410, the pressing piece 420 and the positioning column 410 can be matched to clamp an elbow, and the locking nut 440 is screwed on the connecting rod 430 in a threaded mode and is abutted to one side, away from the pressing piece 420, of the positioning column 410.

One end of the connecting rod 430 is preferably welded to the pressing member 420, and a through hole is formed at the top of the positioning column 410, through which the connecting rod 430 can pass and slide to drive the pressing member 420 to approach or depart from the positioning column 410, so that the pressing member 420 can cooperate with the positioning column 410 to clamp the fixed elbow. The other end of the connection rod 430 has a threaded section on which a lock nut 440 is threaded. The retaining nut 440 can abut against the positioning column 410 at a side of the positioning column 410 away from the pressing piece 420, so that the pressing piece 420 and the positioning column 410 are matched to clamp the elbow, and the elbow is prevented from deviating or rotating. When the elbow and the straight pipe section to be welded need to be fixed, the lock nut 440 can be loosened to enlarge the distance between the pressing member 420 and the positioning column 410, the elbow is placed between the pressing member 420 and the positioning column 410, and then the lock nut 440 is screwed tightly, so that the pressing member 420 presses the elbow against the positioning column 410.

The positioning column 410 is preferably rotatably connected with the base 100, and the rotation axis of the positioning column 410 is collinear with the rotation axis of the rotating disc 200, so that the second fixing assembly 400 can integrally rotate around the axis of the positioning column 410, thereby adjusting the clamping position of the second fixing assembly 400 on the elbow, and better adapting to the fixation of elbows with different bending angles.

The first fixing assembly 300 comprises a baffle plate 310 and a clamping unit 320, wherein the clamping unit 320 is opposite to and spaced from the baffle plate 310 so as to be matched with and clamp a straight pipe section. Preferably, the distance between the clamping unit 320 and the baffle 310 can be adjusted to fit straight pipe sections of different pipe diameters and improve the clamping stability and convenience of the straight pipe sections.

The clamping unit 320 preferably includes a fixing plate 321 and an adjusting bolt 322, the fixing plate 321 is opposite to and spaced apart from the baffle plate 310, the adjusting bolt 322 is screwed on the fixing plate 321, and the tip of the adjusting bolt 322 extends between the fixing plate 321 and the baffle plate 310 to abut against the straight pipe section. The adjusting bolts 322 are loosened, the straight pipe section is placed between the baffle plate 310 and the fixing plate 321, and the adjusting bolts 322 are adjusted until the straight pipe section is compacted but can move in the axial direction. The position of the straight pipe section is adjusted, the straight pipe section is abutted to the elbow, the adjusting bolt 322 is screwed down to finish fixing the straight pipe section, the operation is simple and convenient, and the efficiency of fixing the straight pipe section is improved.

The baffle 310 is preferably a long strip of metal plate welded to the base 100. The fixing plate 321 is spaced apart from and parallel to the baffle 310. A plurality of threaded through holes are formed in the fixing plate 321, the adjusting bolts 322 are screwed on the threaded through holes of the fixing plate 321, penetrate through the fixing plate 321 and abut against the straight pipe section to be welded, and the straight pipe section to be welded is clamped and fixed through the baffle plate 310. Alternatively, a slide rail may be provided on the base 100, and the baffle 310 and the clamping unit 320 are mounted at two ends of the slide rail, and the distance between the baffle 310 and the clamping unit 320 is adjusted by sliding the clamping unit 320 or the baffle 310 on the slide rail.

The elbow welding and fixing device provided by the embodiment is used for clamping and fixing a straight pipe section through the matching of the baffle plate 310 and the clamping unit 320, and the positioning column 410 and the pressing piece 420 are used for clamping an elbow in a matching manner.

It should be noted that the parameters such as the maximum distance between the pressing member 420 and the positioning column 410, the specific distance between the fixing plate 321 and the baffle 310, the number of the threaded through holes on the fixing plate 321, and the aperture should be designed according to the actual application range of the elbow welding device, and the application is not limited specifically.

As shown in fig. 3, on the basis of the above-mentioned embodiment, in an optional implementation manner, the utility model provides an arc-shaped groove 210 has been seted up on the rotary disk 200, the centre of a circle of arc-shaped groove 210 is located the rotation axis of rotary disk 200, be equipped with on the base 100 with the arc-shaped groove 210 just to the screw hole 110 of intercommunication, the rotary disk 200 is fastened through the locking bolt 220 who wears to locate screw hole 110 and arc-shaped groove 210 with base 100.

The utility model provides an elbow welding fixing device, can with the 110 threaded connection of screw hole on the base 100 through locking bolt 220, compress tightly rotary disk 200 fixedly, it is the arc wall 210 of rotary disk 200 rotation axis to open the centre of a circle through on the rotary disk 200, make locking bolt 220 can slide in arc wall 210, it is rotatory at needs rotary disk 200, when first fixed subassembly 300 angle on the adjustment rotary disk 200, the locking bolt 220 of unscrewing, just can rotate rotary disk 200, realize the regulation of first fixed subassembly 300 angle and the locking after the angle modulation.

Specifically, a plurality of threaded holes 110 are formed in the bottom plate facing the lower side of the arc-shaped groove 210, and the threaded holes 110 are arranged at intervals along the circumferential direction of the rotating disk 200. The locking bolt 220 can pass through the arc-shaped slot 210 to be in threaded connection with the threaded hole 110, and the bolt head of the locking bolt 220 is tightly pressed on the rotating disc 200 so as to be rotationally fixed on the base 100. The size of screw hole 110, the model of locking bolt 220, the angle scope of arc wall 210 and the number of screw hole 110 should design according to actual production's needs, the utility model discloses do not do more requirements.

Preferably, an angle scale may be provided on the rotary plate 200 or the bottom plate 100 to indicate an angle between the two first fixing assemblies 300, and when the elbows of different angles are fixed, the rotary plate 200 is fixed by rotating the rotary plate 200 to a designated scale and then screwing the locking bolt 220.

The utility model also provides a pipe fitting processingequipment, including elbow welded fastening device.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, rearrangements and substitutions will now occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An elbow welding fixing device for fixing an elbow and two straight pipe sections to be welded at two ends of the elbow, the elbow welding fixing device comprising:

the two first fixing assemblies (300) can circumferentially rotate around a rotation center relative to each other, and the two first fixing assemblies (300) are respectively used for fixing the two straight pipe sections;

a second fixing member (400) installed at the rotation center, the second fixing member (400) for fixing the elbow.

2. The elbow welding fixture of claim 1, further comprising:

a base (100) having a first support surface;

a rotating disk (200) rotatably connected with the base (100), the rotating disk (200) having a second supporting surface, the first and second supporting surfaces being coplanar, the first and second supporting surfaces each having the first fixing assembly (300) disposed thereon.

3. The elbow welding fixture according to claim 2, wherein the first fixing assembly (300) comprises a baffle plate (310) and a clamping unit (320), the clamping unit (320) is arranged opposite to and spaced from the baffle plate (310) to cooperate to clamp the straight pipe section, and the spacing between the clamping unit (320) and the baffle plate (310) is adjustable;

and/or the second fixing component (400) comprises positioning columns (410) and pressing pieces (420) which are opposite and arranged at intervals, the positioning columns (410) are installed on the base (100), the pressing pieces (420) and the positioning columns (410) are matched for clamping the elbows, and the distance between the pressing pieces (420) and the positioning columns (410) can be adjusted.

4. The elbow welding fixture according to claim 3, wherein the second fixing assembly (400) further comprises a connecting rod (430) and a lock nut (440), one end of the connecting rod (430) is connected with the pressing member (420), the other end of the connecting rod (430) is slidably connected with the positioning column (410) so that the pressing member (420) is close to or away from the positioning column (410), and the lock nut (440) is screwed on the connecting rod (430) and abuts against one side of the positioning column (410) away from the pressing member (420);

and/or the clamping unit (320) comprises a fixing plate (321) and an adjusting bolt (322), the fixing plate (321) is opposite to the baffle plate (310) and is arranged at intervals, the adjusting bolt (322) is screwed on the fixing plate (321) in a threaded mode, and the tail end of the adjusting bolt (322) extends into the space between the fixing plate (321) and the baffle plate (310) to abut against the straight pipe section.

5. The elbow welding fixing device according to claim 3, wherein the rotating disc (200) is rotatably sleeved on the positioning column (410), and the axis of the positioning column (410) is the rotating axis of the rotating disc (200).

6. The elbow welding fixture according to claim 5, characterized in that the positioning column (410) is rotatably connected with the base (100), and the rotation axis of the positioning column (410) is collinear with the rotation axis of the rotating disc (200).

7. The elbow welding fixing device according to any one of claims 2 to 6, wherein an arc-shaped groove (210) is formed in the rotating disc (200), the center of the arc-shaped groove (210) is located on the rotating axis of the rotating disc (200), a threaded hole (110) which is in opposite communication with the arc-shaped groove (210) is formed in the base (100), and the rotating disc (200) and the base (100) are fastened through a locking bolt (220) which is arranged in the threaded hole (110) and the arc-shaped groove (210) in a penetrating manner;

and/or an angle scale is arranged on the rotating disk (200) or the base (100) and used for indicating the rotating angle of the rotating disk (200).

8. The elbow welding fixture according to any one of claims 2 to 6, wherein the base (100) comprises a bottom plate portion (120) and a boss portion (130) protruding from the bottom plate portion (120), a surface of the boss portion (130) remote from the bottom plate portion (120) forming the first supporting surface, and the rotary disk (200) is rotatably mounted on the bottom plate portion (120).

9. The elbow welding fixture according to claim 8, wherein the boss portion (130) and the rotating disk (200) are concentrically arranged fan-shaped structures, and the sum of the central angle corresponding to the boss portion (130) and the central angle corresponding to the rotating disk (200) is less than 360 °.

10. A pipe fitting machining apparatus comprising the elbow welding fixture of any one of claims 1-9.