CN216939178U

CN216939178U - Automobile crane boom standard section assembling and welding fine positioning tool

Info

Publication number: CN216939178U
Application number: CN202220440027.2U
Authority: CN
Inventors: 范立强; 刘甜; 秦小平
Original assignee: Changsha Ruijie Machinery Technology Co ltd
Current assignee: Changsha Ruijie Machinery Technology Co ltd
Priority date: 2022-03-02
Filing date: 2022-03-02
Publication date: 2022-07-12
Anticipated expiration: 2032-03-02

Abstract

The utility model provides a car jib loading boom standard festival equipment welding fine positioning frock, including chassis and 2 locating racks of being connected with the chassis, the locating rack is by a fixed locating rack and 1 movable locating rack of relative installation, or 2 movable locating racks of relative installation constitute, be equipped with the track that supplies movable locating rack to remove on the chassis, be equipped with on the base of movable locating rack and be used for fixing the locking mechanism on the slide rail with movable locating rack, the locating rack includes the base, support frame and locating plate, the locating plate is fixed on the support frame, the support frame is fixed on the base, be equipped with the locating hole on the locating plate, install the positioning mechanism who is used for fixed jib loading boom standard festival to connect on the locating hole. The fine positioning tool for assembling and welding the standard sections of the automobile crane boom can be used for assembling and welding the standard sections of the crane boom with different length specifications between 5m and 20m by adjusting the position of the movable positioning frame on the movable base and quickly adjusting the processing length of the tool.

Description

Automobile crane boom standard section assembling and welding fine positioning tool

Technical Field

The utility model relates to an assembling and welding tool for a standard section of a crane boom of a truck crane, in particular to an assembling and welding precise positioning tool for the standard section of the crane boom.

Background

The automobile crane is one kind of crane installed on common or special automobile chassis and has driving cab separated from the crane control cab. The crane boom of the automobile crane consists of a plurality of sections of boom sections, and the plurality of sections of standard sections need to be assembled, welded and molded during the production of the crane boom.

The assembly welding forming tool of the crane boom mostly adopts a fixed tool, and can meet the requirements of assembly welding, but because the fixed tool has single function and poor universality, different fixed tools are required to be adopted when the crane booms of different models are positioned and welded, so that a large-area production workshop is occupied, and a large amount of raw materials and time are wasted; in the prior art, CN205148143U discloses a modular flat-head tower crane boom forming tool, which completes the manufacture of single sections of booms with different length specifications by changing the installation position of a right upright post on a tool underframe and fixing upper and lower chord rods of the single section of the boom, but the adjustable length range of the modular flat-head tower crane boom forming tool is relatively small, and the assembling requirements of the booms with various specifications of an automobile crane are difficult to meet; the single-section combined tool for the crane boom disclosed in CN201913420U is suitable for the combination of tower crane booms and the assembly of automobile crane booms, is inconvenient for the assembly of standard sections with different widths or heights, and secondly, the existing crane boom forming tool cannot effectively solve the problem that the standard sections with large sections are easy to deform in the assembly processing process.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is as follows: the defects of the prior art are overcome, and the assembly welding fine positioning tool for the standard section of the automobile crane boom, which has a simple structure and is convenient to use and can effectively prevent the deformation phenomenon during the processing of the large-section standard section, is provided.

The technical scheme adopted by the utility model for solving the technical problems is as follows:

the utility model provides a car jib loading boom standard festival equipment welding fine positioning frock, includes chassis and 2 locating rests of being connected with the chassis, the locating rest comprises a fixed position frame and 1 movable position frame of relative installation, or 2 movable position frames of relative installation, be equipped with the accurate track that supplies the movable position frame to remove on the chassis, be equipped with on the base of movable position frame and be used for fixing the locking mechanism on accurate track with movable position frame, the locating rest includes base, support frame and locating plate, the locating plate is fixed on the support frame, the support frame is fixed on the base, is equipped with the locating hole on the locating plate (the locating hole symmetry sets up on fixed position frame and movable position frame, or 2 relative panels of movable position frame), installs the positioning mechanism who is used for fixed standard festival to connect on the locating hole.

In an exemplary embodiment, the tool further comprises an auxiliary supporting beam, and the auxiliary supporting beam is vertically fixed on the positioning plate and located outside the positioning block.

The auxiliary supporting beam is a rod-shaped piece, a pin shaft insertion hole and a fixing through hole are formed in the auxiliary supporting beam, the auxiliary supporting beam is arranged on a positioning plate connected with a positioning bolt penetrating through the fixing through hole, and a hinge lug to be welded is fixed on the auxiliary supporting beam through a pin shaft penetrating through the pin shaft insertion hole, so that different cross-sectional sizes of the hinge lug are welded.

Preferably, the underframe comprises a fixed underframe and a movable underframe, the fixed underframe and the movable underframe are detachably connected through nuts or screws, the movable underframe is provided with a precise track, the precise track is a sliding rail, and the sliding rail is in sliding connection with the movable positioning frame.

Preferably, locking mechanism includes sliding pin and retaining member, the sliding pin sets up on movable base, the retaining member is for running through movable base and with the inserted bar of sliding pin cooperation use.

Preferably, the positioning holes comprise an upper positioning hole and a lower positioning hole, and the upper positioning hole and the lower positioning hole are symmetrically arranged and distributed on the upper half part and the lower half part of the positioning plate in a matrix manner.

Preferably, the positioning mechanism comprises a positioning block and an ear plate positioning auxiliary device, and the positioning block is connected with the ear plate positioning auxiliary device. The locating piece includes interconnect's horizontal stopper and vertical stopper, and vertical stopper is located one side that horizontal stopper is close to the locating plate outside along, horizontal stopper is equipped with the spacing groove, and is preferred, and the spacing groove is waist shape spacing groove, spacing hole has been seted up to vertical stopper, the locating piece is connected with otic placode location auxiliary device through the round pin axle of wearing to establish in spacing hole.

Preferably, a reinforcing plate is arranged at the joint of the horizontal limiting block and the vertical limiting block.

In a certain exemplary embodiment, the chassis is provided with a support at intervals for supporting the standard knot of the lifting arm, preferably, the support is a movable lifting support, the movable lifting support comprises a sliding mechanism matched with a sliding rail of the movable chassis, a lifting mechanism and a support body for supporting the standard knot, the sliding mechanism is mounted at the bottom of the support body, the lifting mechanism is mounted at two sides of the support body, the telescopic rod is determined to stretch, the height of the support body is further adjusted, the lifting height of the support is adjusted through the lifting mechanism, the support for the middle part of the standard knot is facilitated, and the stability of subsequent processing is improved.

The utility model discloses a vehicle crane boom standard section assembling, welding and fine positioning tool, which is used for a vehicle crane boom standard section assembling and forming method, and specifically comprises the following steps:

s1, tool position adjustment: according to the specification of the standard knot of the crane boom to be processed, the position of the movable positioning frame on the movable base is adjusted, and then the positions of the positioning blocks on the fixed positioning frame and the movable positioning frame are adjusted, so that the length, the height and the width of the tool are matched with the standard knot of the crane boom to be processed;

s2, fixing a standard section of a crane boom: the positioning position is finely adjusted according to the specification of the standard knot by adjusting the positions of the positioning block and the lug plate positioning auxiliary device, and then the joint of the standard knot of the crane boom is inserted with a pin shaft and fixed on the lug plate positioning auxiliary device of the tool;

s3, welding: and processing the standard sections of the crane boom according to the processing requirements.

In the step S2, an auxiliary support beam is further added to the boom standard knot joint, and the boom standard knot joint of the boom standard knot or the hinge lug to be welded is fixed by inserting a pin shaft into the pin shaft insertion hole of the auxiliary support beam, so that the large-section standard knot is prevented from being deformed during welding.

In S3, after the hinge lug is assembled, the standard pitch chord tube body is adjusted to be inserted into the hinge lug without interference, the lower layer is riveted and welded firstly and then the upper layer is riveted and welded according to rivet welding, and the upper layer screw and the lower layer screw are dismounted according to dismounting of the workpiece.

The assembly welding fine positioning tool for the standard section of the automobile boom has the beneficial effects that:

according to the assembly welding fine positioning tool for the standard sections of the automobile crane boom, the position of the movable positioning frame on the movable base is adjusted, the processing length of the tool is quickly adjusted, the tool can be used for assembly welding of standard sections of crane booms with different length specifications between 5m and 20m, one set of tool can process standard sections of crane booms with various specifications, and compared with a conventional fixed standard section assembly welding tool, the equipment investment is reduced, and the space utilization rate of a workshop for producing the standard sections of crane booms is improved; the positioning holes distributed in a matrix form are formed in the positioning plate of the tool, so that the positioning blocks can be conveniently and quickly fixed at proper positions of the positioning plate, and the standard sections of the crane boom with different heights and widths can be processed; horizontal stopper and vertical stopper on the locating piece are convenient for finely tune otic placode location auxiliary device's position, have improved the precision that the frock was processed jib loading boom standard festival.

This assembly welding fine positioning frock of car jib loading boom standard festival through addding auxiliary supporting beam for the big cross-section jib loading boom standard festival of processing is saved, through the support of auxiliary supporting beam to the standard festival, can effectively prevent the deformation of standard festival in the course of working.

The support frame can carry out better support to the middle part of standard festival, has improved the stability during standard processing to improve the processingquality of jib loading boom standard festival, movable type lift support frame can adjust its self height according to the standard festival of different specifications, plays better supporting role to the standard festival.

The assembly welding fine positioning tool for the automobile crane boom is simple to operate when being used for assembly molding of the standard sections of the automobile crane boom, and is suitable for assembly processing of the standard sections of the automobile crane boom with different specifications. After the precise positioning welding of the tool, the whole process after welding is not needed, the assembly requirement can be met, the high processing cost is saved, and the manufacturing efficiency of the standard section of the crane boom is greatly improved.

Drawings

FIG. 1 is a three-dimensional structure diagram of an assembly welding fine positioning tool for a standard section of a crane boom in embodiment 1;

FIG. 2 is a front view of an assembly welding fine positioning tool for a standard section of a crane boom in embodiment 1;

FIG. 3 is a right side view of the assembly welding fine positioning tool for the standard section of the automobile boom in the embodiment 1;

FIG. 4 is a top view of the assembly welding fine positioning tool for the standard section of the crane boom in the embodiment 1;

FIG. 5 is a schematic front view of a movable positioning frame in the assembly welding fine positioning tool for the standard sections of the crane boom in embodiment 1;

FIG. 6 is a perspective view of a positioning mechanism in the assembly welding fine positioning tool for the standard sections of the crane boom in embodiment 1;

fig. 7-an enlarged schematic view at a in fig. 1.

FIG. 8 is a schematic perspective view of an assembly welding precision positioning tool for a standard section of a crane boom in embodiment 2;

FIG. 9 is a front view of an auxiliary support beam of the assembly welding fine positioning tool for the standard section of the crane boom in embodiment 2;

FIG. 10 is a front view of a positioning plate and a positioning mechanism of the assembly welding fine positioning tool for the standard knot of the automobile boom in embodiment 2 in a use state;

fig. 11 is a schematic front structural view of a movable positioning frame for assembling a single-hinge-lug standard knot in the assembly and welding precision positioning tool for the standard knot of the automobile boom in embodiment 2;

fig. 12 is a schematic front structural view of a movable positioning frame of the assembly welding fine positioning tool for the standard section of the automobile crane boom in the embodiment 2 when the double-hinge-lug standard section is assembled;

fig. 13 is a schematic perspective view of a positioning tool for assembling and welding standard sections of a crane boom in embodiment 3;

fig. 14 is a schematic perspective view of a support in the assembly welding fine positioning tool for the standard sections of the crane boom in embodiment 3.

In the figure: 1. the device comprises a base frame, 101, a movable base frame, 1011, a track, 102, a fixed base frame, 2, a fixed positioning frame, 201, a fixed base frame, 3, a movable positioning frame, 301, a positioning plate, 3011, a positioning hole, 302, a supporting frame, 303, a movable base frame, 4, a positioning mechanism, 401, a horizontal limiting block, 402, a vertical limiting block, 403, an ear plate positioning auxiliary device, 404, a limiting groove, 405, a limiting hole, 406, a reinforcing plate, 5, a pin shaft, 6, a locking mechanism, 601, a sliding pin, 602, a locking member, 7, an auxiliary supporting beam, 701, a fixing through hole, 702, a pin shaft jack, 8, a crane boom standard section, 9, a standard section joint, 901, a single hinge lug, 902, a double hinge lug, 10, a support, 1001, a frame body, 1002, a lifting mechanism, 1003 and a sliding mechanism.

Detailed Description

The utility model is further explained with reference to the drawings and the embodiments.

Example 1

Referring to fig. 1 to 7 and fig. 1 to 7, the assembly welding fine positioning tool for the standard section of the automobile boom comprises an underframe 1, a fixed positioning frame 2 and a movable positioning frame 3, wherein the underframe is provided with a precision rail 1011 for the movable positioning frame 3 to move, a base of the movable positioning frame 3 is provided with a locking mechanism 6 for fixing the movable positioning frame 3 on the precision rail 1011, the fixed positioning frame 2 comprises a fixed base 201, a supporting frame 302 and a positioning plate 301, the movable positioning frame 3 comprises a movable base 303, a supporting frame 302 and a positioning plate 301, the positioning plate 301 is fixed on the supporting frame 302, the supporting frame 302 is fixed on the base, the positioning plate 301, opposite to the fixed positioning frame 2 and the movable positioning frame 3, is provided with a positioning hole, and the positioning mechanism 4 for fixing the joint of the standard section 8 of the boom is installed on the positioning hole.

The base frame comprises a fixed base frame 102 and a movable base frame 101, the fixed base frame 102 is detachably connected with the movable base frame 101 through nuts or screws, the movable base frame 101 is provided with a precise track 1011, the precise track 1011 is a sliding rail, and the sliding rail is in sliding connection with the movable positioning frame 3.

The locking mechanism 6 comprises a sliding pin 601 and a locking member 602, the sliding pin 601 is arranged on the movable base 303, and the locking member 602 is an inserted rod which penetrates through the movable base 303 and is matched with the sliding pin 601 for use. The movable base 303 is provided with a through hole for the locking piece 602 to pass through at a position corresponding to the sliding pin 601.

The positioning holes 3011 include an upper positioning hole and a lower positioning hole, which are symmetrically disposed and distributed in a matrix form on the upper half portion and the lower half portion of the positioning plate 301.

The positioning mechanism 4 comprises a positioning block and an ear plate positioning auxiliary device 403, and the positioning block is connected with the ear plate positioning auxiliary device 403. The locating piece includes horizontal stopper 401 and vertical stopper 402, horizontal stopper 401 is equipped with spacing groove 404, and is preferred, and spacing groove 404 is kidney-shaped spacing groove 404, spacing hole 405 has been seted up to vertical stopper 402, the locating piece is connected with otic placode location auxiliary device 403 through the round pin axle 5 of wearing to establish in spacing hole 405.

And a reinforcing plate 406 is arranged at the joint of the horizontal limiting block 401 and the vertical limiting block 402.

According to the assembling and welding tool for the standard section 8 of the automobile crane boom, the processing length of the tool is quickly adjusted by adjusting the position of the movable positioning frame 3 on the movable base 303, the tool can be used for assembling and welding the standard sections 8 of the crane boom with different length specifications between 5m and 20m, one set of tool can process the standard sections 8 of the crane boom with various specifications, the equipment investment is reduced compared with the assembling and welding tool for the standard sections which are fixed conventionally, and the space utilization rate of a workshop for producing the standard sections 8 of the crane boom is improved; the positioning plate 301 of the fixture is provided with positioning holes distributed in a matrix form, so that the positioning blocks can be conveniently and quickly fixed at proper positions of the positioning plate 301, and the standard sections 8 of the crane boom with different heights and widths can be processed; the horizontal limiting block 401 and the vertical limiting block 402 on the positioning block facilitate fine adjustment of the position of the ear plate positioning auxiliary device 403, and the precision of the tool for processing the crane boom standard section 8 is improved.

The assembly welding and fine positioning tool for the standard sections of the automobile cargo boom is used for an assembly forming method for the standard sections of the automobile cargo boom, and comprises the following steps:

s1, tool position adjustment: according to the specification of the standard knot 8 of the crane boom to be processed, the position of the movable positioning frame 3 on the movable base 303 is adjusted, and then the positions of the positioning blocks on the fixed positioning frame 2 and the movable positioning frame 3 are adjusted, so that the length, the height and the width of the tool are matched with the standard knot 8 of the crane boom to be processed;

s2, fixing a standard section 8 of a crane boom: the positioning position is finely adjusted according to the specification of the standard knot by adjusting the positions of the positioning block and the ear plate positioning auxiliary device 403, and then the joint of the crane boom standard knot 8 is inserted with a pin shaft 5 and fixed on the ear plate positioning auxiliary device 403 of the tool;

s3, welding: and processing the standard sections 8 of the cargo boom according to the processing requirements.

S1, the specific operation of tool position adjustment is as follows: according to the length of the standard section 8 of the crane boom of the automobile crane, which needs to be processed in practice, the locking part 602 in the locking mechanism 6 is pulled out from the sliding pin 601, then the movable positioning frame 3 slides to a proper position along the sliding rail on the movable bottom frame 101, and then the locking part 602 is clamped in the sliding pin 601, so that the movable positioning frame 3 is fixed on the movable bottom frame 101, the length between the fixed positioning frame 2 and the movable positioning frame 3 is adjusted to the length of a corresponding specification, and the single section manufacturing requirements of the crane boom with different length specifications of the crane boom are met.

According to the height and width of the standard section 8 of the crane boom to be processed in practice, a positioning hole 3011 where a corresponding position (including a longitudinal and a transverse relative position) of a positioning block on the positioning plate 301 is located is determined (generally, the corresponding position of the center of the standard section 8 is projected to the center of the positioning plate 301 as much as possible), and then the relative height and width of the positioning block are fixed through nuts or screws sequentially penetrating through the positioning hole 3011 and a limiting groove 404 on a horizontal limiting block 401 of the positioning block, so that the processing requirements of the standard sections 8 of the crane boom with different heights and widths are met; and then according to the width of the standard section 8 of the crane boom to be processed in practice, the width range of the standard section 8 is finely adjusted by transversely moving the positioning block relative to the positioning hole, and the eccentric value of the auxiliary positioning device 403 is adjusted by adjusting the connecting position of the auxiliary positioning device 403 and the vertical limiting block 402, so that the fine adjustment of the height range of the standard section 8 is completed.

Example 2

Referring to fig. 8 to 12, compared with embodiment 1, the assembly welding fine positioning tool for the standard section of the automobile boom of the present embodiment has the following differences:

the tool further comprises an auxiliary supporting beam 7, wherein the auxiliary supporting beam 7 is vertically fixed on the positioning plate 301 and is positioned outside the positioning block.

The auxiliary support beam 7 is a square rod-shaped member, a pin shaft insertion hole 702 and a fixing through hole 701 are formed in the auxiliary support beam 7, the auxiliary support beam 7 is fixedly connected to the positioning plate 301 through a positioning bolt penetrating through the fixing through hole 701 and the positioning hole 3011, and a joint (such as a hinge lug) to be standard is fixed on the auxiliary support beam 7 through a pin shaft 5 penetrating through the pin shaft insertion hole 702, so that the purpose of assembling the joint on a standard section of the crane boom is achieved, the requirement of forming standard assembling sections with different section sizes can be met, and the deformation of the standard section of the crane boom in the assembling and forming process can be avoided.

s2, fixing a standard section 8 of a crane boom: when the auxiliary support beam is used for assembling and forming the single hinge lug 901 standard section of the automobile crane boom, referring to the attached drawing 11, an auxiliary support beam 7 is added at the joint of the crane boom standard section 8, the positioning position is finely adjusted according to the specification of the standard section by adjusting the position of a positioning block and an ear plate positioning auxiliary device 403, and the joint of the crane boom standard section 8 or the single hinge lug 901 to be welded is fixed by inserting a pin 5 into a pin jack 702 of the auxiliary support beam 7, so that the large-section standard section is prevented from deforming during welding; when the auxiliary support beam 7 is used for assembling and forming the single hinge lug 901 standard knot of the automobile crane boom, referring to the attached drawing 12, the auxiliary support beam 7 is fixed on the positioning plate 301, the positioning position is finely adjusted according to the specification of the standard knot by adjusting the position of the positioning block and the lug plate positioning auxiliary device 403, and the joint of the crane boom standard knot 8 or the double hinge lugs 902 to be welded is fixed by inserting the pin shaft 5 into the pin shaft insertion hole 702 of the auxiliary support beam 7, so that the large-section standard knot is prevented from deforming during welding;

Example 3

Referring to fig. 13 and 14, compared with embodiment 1, the following differences exist in the assembly welding fine positioning tool for the standard section of the car boom in this embodiment:

be equipped with the interval on chassis 1 and be equipped with the support 10 that is used for supporting jib standard festival, preferably, support 10 includes the support body 1001 with activity chassis 101 slide rail assorted slide mechanism 1003, elevating system 1002 and support standard festival for activity type lifting support 10, slide mechanism 1003 installs in the bottom of support body 1001, elevating system 1002 installs in the both sides of support body 1001 to confirm that the telescopic link is flexible, and then adjust the height of support body 1001, adjust the lift height of support 10 through elevating system 1002, be convenient for to the support at 8 middle parts of jib boom standard festival, be convenient for improve the stability of follow-up processing.

The assembly welding fine positioning tool for the standard section of the automobile boom is used for the assembly forming method of the standard section of the automobile boom, and is different from the assembly forming method in the embodiment 2 in the following points:

s1, tool position adjustment: still include through the height of adjusting activity type lifting support 10, make the top of the support body 1001 of activity type lifting support 10 and the lower chord bottom surface butt of jib loading boom standard festival 8, and then carry out better support to jib loading boom standard festival 8, be favorable to improving the stability of follow-up processing.

The utility model relates to an assembly welding fine positioning tool for a standard section of a car boom, wherein an underframe 1 can adopt a single structure of a movable underframe 1 with a track besides the combined structure exemplified by the embodiment, and two movable positioning frames 3 are arranged on the underframe, so the same effect can be realized.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the utility model and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the utility model. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

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

Claims

1. A precise positioning tool for assembling and welding standard sections of a car boom is characterized by comprising an underframe (1) and 2 positioning frames connected with the underframe, the positioning frame consists of a fixed positioning frame (2) and 1 movable positioning frame (3) which are oppositely arranged or 2 movable positioning frames (3) which are oppositely arranged, a precise track (1011) for the movable positioning frame (3) to move is arranged on the bottom frame, a locking mechanism (6) used for fixing the movable positioning frame (3) on the precision track (1011) is arranged on the base of the movable positioning frame (3), the positioning frame comprises a base, a supporting frame (302) and a positioning plate (301), the positioning plate (301) is fixed on the support frame (302), the support frame (302) is fixed on the base, a positioning hole (3011) is formed in the positioning plate (301), and a positioning mechanism (4) used for fixing a joint of a boom standard section (8) is installed on the positioning hole (3011).

2. The assembly welding fine positioning tool for the standard knot of the automobile boom in claim 1, further comprising an auxiliary support beam (7), wherein the auxiliary support beam (7) is vertically fixed on the positioning plate (301) and is positioned outside the positioning block.

3. The assembly welding fine positioning tool for the standard knot of the automobile boom according to claim 2, wherein the auxiliary supporting beam (7) is a rod-shaped member, a pin shaft (5) insertion hole and a fixing through hole are formed in the rod-shaped member, the auxiliary supporting beam (7) is connected to the positioning plate (301) through a positioning bolt inserted into the fixing through hole, and a hinge lug to be welded is fixed to the auxiliary supporting beam (7) through the pin shaft (5) inserted into the pin shaft (5) insertion hole.

4. The assembly welding fine positioning tool for the standard section of the automobile boom according to any one of claims 1 to 3, wherein the bottom frame (1) comprises a fixed bottom frame (102) and a movable bottom frame (101), the fixed bottom frame (102) and the movable bottom frame (101) are detachably connected through nuts or screws, a precise track (1011) is arranged on the movable bottom frame (101), and the precise track (1011) is in sliding connection with the movable positioning frame (3).

5. The assembly welding fine positioning tool for the standard section of the automobile boom according to any one of claims 1 to 3, wherein the locking mechanism (6) comprises a sliding pin (601) and a locking member (602), the sliding pin (601) is arranged on the movable base (303), and the locking member (602) is an inserted rod which penetrates through the movable base (303) and is matched with the sliding pin (601).

6. The assembly welding fine positioning tool for the standard knot of the automobile boom according to any one of claims 1 to 3, wherein the positioning holes (3011) comprise an upper positioning hole and a lower positioning hole, and the upper positioning hole and the lower positioning hole are symmetrically arranged and distributed in a matrix form on the upper half part and the lower half part of the positioning plate (301).

7. The assembly welding fine positioning tool for the standard section of the automobile boom according to claim 1, wherein the positioning mechanism (4) comprises a positioning block and an auxiliary ear plate positioning device (403), the positioning block comprises a horizontal limiting block (401) and a vertical limiting block (402) which are connected with each other, the horizontal limiting block (401) is provided with a limiting groove (404), the vertical limiting block (402) is provided with a limiting hole (405), and the positioning block is connected with the auxiliary ear plate positioning device (403) through a pin shaft (5) which is inserted into the limiting hole (405).

8. The assembly welding fine positioning tool for the standard section of the automobile boom according to claim 7, wherein a reinforcing plate (406) is arranged at the joint of the horizontal limiting block (401) and the vertical limiting block (402).

9. The assembly welding fine positioning tool for the standard section of the automobile boom according to any one of claims 1 to 3, wherein supports (10) for supporting the standard section (8) of the boom are arranged on the underframe at intervals.

10. The assembly welding fine positioning tool for the standard knot of the automobile boom according to claim 9, wherein the support (10) is a movable lifting support, the movable lifting support comprises a sliding mechanism (1003) matched with a sliding rail of a movable underframe, a lifting mechanism (1002) and a support body (1001) supporting the standard knot, the sliding mechanism (1003) is installed at the bottom of the support body (1001), and the lifting mechanism (1002) is installed at two sides of the support body (1001).