Excavator big arm inner cavity assembling spacing control tool

Abstract

The utility model relates to the technical field of engineering machinery, in particular to an excavator big arm inner cavity splicing spacing control tool which comprises a positioning ejector rod and a clamping mechanism, the positioning ejector rod is used for being arranged between a left web and a right web, and the clamping mechanism is used for clamping the left web and the right web. The length of the positioning ejector rod is equal to the designed distance between the left web plate and the right web plate; the clamping mechanism is used for driving the left web plate and the right web plate to move in the direction close to each other, so that the left web plate and the right web plate abut against the two ends of the positioning ejector rod correspondingly, and the left web plate and the right web plate abut against the two connecting parts, in the left-right direction, of the supporting base correspondingly. According to the excavator big arm inner cavity splicing distance control tool, on one hand, the excavator big arm splicing efficiency is improved, on the other hand, the step of adjusting the distance between the left web plate and the right web plate through knocking is omitted, and the problem that the hearing of workers is affected by noise is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering machinery, in particular to an assembly spacing control tool for an inner cavity of an excavator arm. Background Art

[0002] As an engineering equipment widely used in mining, roads, water conservancy, construction and other fields, excavators have sufficient demand in the global market. They are an essential part of the construction machinery industry and play an important role in supporting the construction of the national economy. Therefore, in order to meet the huge domestic and foreign market demand, the production efficiency of excavators must be improved.

[0003] The boom of an excavator usually includes left and right webs and a support seat. At present, during the production and manufacturing of the boom of an excavator, it is necessary to control the assembly spacing of the left and right webs of the boom to be consistent to ensure the stability of the boom structure. The left and right webs of the boom are now tightened to the overlapping position of the support seat through a tightening device, and then a copper hammer is used to knock on the middle part of the web to adjust the inner cavity assembly spacing of the left and right webs. After the assembly spacing is measured to be qualified, the left and right webs and the support seat are positioned welded. In this process, the adjustment of the inner cavity assembly spacing requires multiple copper hammer knocking adjustments and size measurements, which affects the work efficiency of employees. The copper hammer knocking is labor-intensive and produces a lot of noise. After long-term operation, it will affect the hearing of employees.

[0004] Therefore, there is an urgent need for an excavator boom inner cavity assembly spacing control tooling to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a tooling for controlling the inner cavity assembly spacing of an excavator boom, so as to solve the problems in the related art that during the production and manufacturing of the excavator boom, in order to adjust the spacing of the left and right webs to be consistent, the processing efficiency is low, and when the spacing of the left and right webs is adjusted by knocking, the noise easily affects the hearing of the employees.

[0006] The utility model provides an excavator arm inner cavity assembly spacing control tool, the excavator arm inner cavity assembly spacing control tool comprises:

[0007] A positioning mandrel, the positioning mandrel is used to be arranged between the left web and the right web, and the length of the positioning mandrel is the designed spacing between the left web and the right web;

[0008] A clamping mechanism is used to drive the left web and the right web to move towards each other, so that the left web and the right web are respectively abutted against the two ends of the positioning push rod and the left web and the right web are respectively abutted against the two connecting parts of the support seat along the left and right directions.

[0009] As an optimal technical solution for assembling spacing control tooling in the inner cavity of an excavator boom, the positioning push rod includes a rod portion and a telescopic portion arranged at one or both ends of the rod portion along the left and right directions, and the telescopic portion can be telescoped relative to the rod portion along the left and right directions.

[0010] As a preferred technical solution for assembling spacing control tooling in the inner cavity of an excavator boom, a threaded hole is recessed at a position opposite to the rod and the telescopic part, and the telescopic part extends into the threaded hole and is threadedly connected to the rod.

[0011] As an optimal technical solution for assembling spacing control tooling in the inner cavity of an excavator boom, the positioning push rod also includes a hanging ear, which is fixedly connected to the rod portion, and the hanging ear is mounted on the left web and / or the right web so that the rod portion is perpendicular to the left web and the right web respectively.

[0012] As an optimal technical solution for assembling spacing control tooling in the inner cavity of an excavator boom, the hanging ear includes a lap rod and a connecting rod, one end of the connecting rod is fixedly connected to the rod portion, and the other end of the connecting rod is fixedly connected to the middle portion of the lap rod, and both ends of the lap rod are respectively lapped on the left web and the right web and are respectively perpendicular to the left web and the right web, so that the rod portion is located between the left web and the right web and are respectively perpendicular to the left web and the right web.

[0013] As an optimal technical solution for assembling spacing control tooling in the inner cavity of an excavator boom, the clamping mechanism includes a left tightening assembly and a right tightening assembly. The left tightening assembly is arranged on a side of the left web away from the right web and pushes the left web toward the right web, and the right tightening assembly is arranged on a side of the right web away from the left web and pushes the right web toward the left web.

[0014] As a preferred technical solution for the assembly spacing control tooling of the excavator boom inner cavity, the left tightening assembly includes a left driving member and a left pressure plate, and the left driving member drives the left pressure plate to move along the left and right directions and pushes the left web plate to move in a direction close to the right web plate;

[0015] The right pressing assembly includes a right driving member and a right pressure plate. The right driving member drives the right pressure plate to move along the left-right direction and pushes the right web plate to move toward the direction close to the left web plate.

[0016] As a preferred technical solution for assembling the spacing control tooling of the inner cavity of the excavator arm, the left tightening assembly also includes a left frame and a left guide rod, the left frame is concavely provided with a left guide hole along the left and right directions, the left guide rod is inserted into the left guide hole and fixedly connected to the left pressure plate;

[0017] The right tightening assembly also includes a right frame and a right guide rod. The right frame is concavely provided with a right guide hole along the left-right direction. The right guide rod is inserted into the right guide hole and fixedly connected to the right pressure plate.

[0018] As a preferred technical solution for the assembly spacing control tooling of the excavator boom inner cavity, at least two left guide rods are provided, at least two left guide holes are provided on the left frame, and at least two left guide rods are inserted into the at least two left guide holes in a one-to-one correspondence;

[0019] At least two right guide rods are provided, and at least two right guide holes are provided on the right frame. At least two right guide rods are inserted into the at least two right guide holes in a one-to-one correspondence.

[0020] As a preferred technical solution for the assembly spacing control tooling of the excavator boom inner cavity, the surface of the left web away from the right web is provided with a stepped structure, and the surface of the right web away from the left web is provided with a stepped structure;

[0021] The left tightening assembly further comprises a plurality of left abutment blocks, which are arranged on a side of the left pressure plate opposite to the left web plate and have different thicknesses along the left-right direction, and the plurality of left abutment blocks respectively abut against the step structures on the left web plate to make the left pressure plate parallel to the left web plate;

[0022] The right tightening assembly also includes a plurality of right abutment blocks, which are arranged on the side of the right pressure plate opposite to the right web plate and have different thicknesses along the left and right directions, and the plurality of right abutment blocks respectively abut against the stepped structures on the right web plate to make the right pressure plate parallel to the right web plate.

[0023] The beneficial effects of the utility model are:

[0024] The utility model provides a tool for controlling the inner cavity assembly spacing of an excavator boom, which comprises a positioning push rod and a clamping mechanism, wherein the positioning push rod is used to be arranged between a left web and a right web, and the length of the positioning push rod is the designed spacing between the left web and the right web; the clamping mechanism is used to drive the left web and the right web to move in a direction approaching each other, so that the left web and the right web are respectively abutted against the two ends of the positioning push rod and the left web and the right web are respectively abutted against the two connecting parts of a support seat along the left and right directions. When assembling the excavator boom, the positioning push rod is set between the left and right webs, and the positioning push rod is perpendicular to the left and right webs at the same time. Then, the left and right webs are driven to move toward each other through the clamping mechanism. Since the length of the positioning push rod is the designed spacing of the left and right webs, when the left and right webs are respectively abutted against the two ends of the positioning push rod, the spacing between the left and right webs meets the designed spacing, and then the left and right webs are respectively abutted against the two connecting parts of the support seat along the left and right directions. At this time, the staff can position and weld the relative positions of the left and right webs and the support seat. The excavator boom inner cavity assembly spacing control tooling not only improves the assembly efficiency of the excavator boom, but also eliminates the step of adjusting the spacing between the left and right webs by knocking, avoiding the problem of noise affecting the hearing of the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the inner cavity assembly spacing control tooling of the excavator arm in the embodiment of the utility model (including the left web plate, the right web plate and the support seat);

[0026] Figure 2 It is a structural schematic diagram of the spacing control tooling for assembling the inner cavity of the excavator arm in the embodiment of the utility model.

[0027] In the figure:

[0028] 100, left belly plate; 200, right belly plate; 300, support seat;

[0029] X, left and right direction;

[0030] 1. Positioning top rod; 11. Rod part; 12. Telescopic part; 13. Hanging ear; 131. Lap rod; 132. Connecting rod;

[0031] 2. Clamping mechanism; 21. Left clamping assembly; 211. Left driving member; 212. Left pressure plate; 213. Left guide rod; 214. Left abutment block; 22. Right clamping assembly; 221. Right driving member; 222. Right pressure plate; 223. Right guide rod; 224. Right abutment block. DETAILED DESCRIPTION

[0032] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0036] like Figure 1 and Figure 2As shown, the present embodiment provides an excavator boom inner cavity assembly spacing control tooling, which includes a positioning push rod 1 and a clamping mechanism 2. The positioning push rod 1 is used to be arranged between the left web 100 and the right web 200, and the length of the positioning push rod 1 is the designed spacing between the left web 100 and the right web 200; the clamping mechanism 2 is used to drive the left web 100 and the right web 200 to move in a direction approaching each other, so that the left web 100 and the right web 200 are respectively abutted against the two ends of the positioning push rod 1 and the left web 100 and the right web 200 are respectively abutted against the two connecting parts of the support seat 300 along the left and right directions X. When assembling the excavator boom, the positioning push rod 1 is set between the left web 100 and the right web 200, and the positioning push rod 1 is perpendicular to the left web 100 and the right web 200 at the same time. Then, the left web 100 and the right web 200 are driven to move towards each other through the clamping mechanism 2. Since the length of the positioning push rod 1 is the design spacing of the left web 100 and the right web 200, when the left web 100 and the right web 200 are respectively abutted against the two ends of the positioning push rod 1, the spacing between the left web 100 and the right web 200 meets the design spacing, and then the left web 100 and the right web 200 are respectively abutted against the two connecting parts of the support seat 300 along the left and right direction X. At this time, the staff can perform positioning welding on the relative positions of the left web 100, the right web 200 and the support seat 300. The excavator boom inner cavity assembly spacing control tooling not only improves the excavator boom assembly efficiency, but also eliminates the step of adjusting the 200 degree spacing between the left and right webs by knocking, thus avoiding the problem of noise affecting the hearing of the workers.

[0037] Specifically, the left-right direction X is the width direction of the excavator.

[0038] Optionally, the positioning mandrel 1 includes a rod portion 11 and a telescopic portion 12 disposed at one or both ends of the rod portion 11 along the left-right direction X, and the telescopic portion 12 can be telescoped relative to the rod portion 11 along the left-right direction X. In this embodiment, since the boom sizes of excavators of different models and specifications are different, the spacing between the left web 100 and the right web 200 is different. In order to make the positioning decision applicable to the booms of excavators of different models and specifications, and thus make the positioning mandrel 1 telescoped along the left-right direction X, both ends of the rod portion 11 can be telescoped. In other embodiments, one end of the rod portion 11 can be telescoped.

[0039] As for the specific connection structure between the rod 11 and the telescopic part 12, optionally, a threaded hole is recessed at the position where the rod 11 and the telescopic part 12 are opposite, and the telescopic part 12 extends into the threaded hole and is screwed with the rod 11. In this embodiment, the length of the positioning push rod 1 is adjusted by screwing the telescopic part 12. In other embodiments, a plurality of buckles may be provided on the rod 11 along the left-right direction X, and a clip is provided on the telescopic part 12, and the clip is engaged with one of the plurality of buckles according to the required length of the positioning push rod 1.

[0040] Optionally, the positioning mandrel 1 further includes a hanging ear 13, the hanging ear 13 is fixedly connected to the rod portion 11, and the hanging ear 13 is mounted on the left web 100 and / or the right web 200, so that the rod portion 11 is respectively perpendicular to the left web 100 and the right web 200. In this embodiment, the hanging ear 13 can facilitate the taking and installation of the positioning mandrel 1 on the one hand, and on the other hand, the hanging ear 13 can limit the positioning mandrel 1, thereby ensuring that the positioning mandrel 1 is respectively perpendicular to the left web 100 and the right web 200.

[0041] Optionally, the lug 13 includes a lap rod 131 and a connecting rod 132, one end of the connecting rod 132 is fixedly connected to the rod portion 11, and the other end of the connecting rod 132 is fixedly connected to the middle portion of the lap rod 131, and the two ends of the lap rod 131 are respectively lapped on the left web 100 and the right web 200 and are respectively perpendicular to the left web 100 and the right web 200, so that the rod portion 11 is located between the left web 100 and the right web 200 and are respectively perpendicular to the left web 100 and the right web 200. In this embodiment, the two ends of the lap rod 131 are respectively lapped on the left web 100 and the right web 200, thereby ensuring that the positioning push rod 1 is located between the left web 100 and the right web 200. By adjusting the lap rod 131 to be perpendicular to the left web 100 and the right web 200, respectively, it can be ensured that the positioning push rod 1 is respectively perpendicular to the left web 100 and the right web 200. Specifically, the axial direction of the lap rod 131 and the axis of the positioning mandrel 1 are located in the same plane.

[0042] Optionally, the clamping mechanism 2 includes a left tightening assembly 21 and a right tightening assembly 22, wherein the left tightening assembly 21 is disposed on a side of the left web 100 away from the right web 200 and pushes the left web 100 to approach the right web 200, and the right tightening assembly 22 is disposed on a side of the right web 200 away from the left web 100 and pushes the right web 200 to approach the left web 100. In this embodiment, the left tightening assembly 21 and the right tightening assembly 22 act independently on the left web 100 and the right web 200, respectively, thereby bringing the left web 100 and the right web 200 closer to each other. In other embodiments, the left tightening assembly 21 may also be fixed, and the right tightening assembly 22 may move in a direction close to the left tightening assembly 21.

[0043] Optionally, the left pressing assembly 21 includes a left driving member 211 and a left pressing plate 212, the left driving member 211 drives the left pressing plate 212 to move along the left-right direction X and pushes the left web 100 to move in a direction close to the right web 200; the right pressing assembly 22 includes a right driving member 221 and a right pressing plate 222, the right driving member 221 drives the right pressing plate 222 to move along the left-right direction X and pushes the right web 200 to move in a direction close to the left web 100. In this embodiment, the left driving member 211 is one of a pneumatic telescopic member, a hydraulic telescopic member, a linear motor, a lead screw nut, and a gear rack, which drives the left pressing plate 212 to move in the left-right direction X. The right pressing assembly 22 has the same structure as the left pressing assembly 21, which will not be repeated here.

[0044] Optionally, the left pressing assembly 21 further includes a left frame and a left guide rod 213, the left frame is provided with a left guide hole along the left-right direction X, the left guide rod 213 is inserted in the left guide hole and is fixedly connected to the left pressing plate 212; the right pressing assembly 22 further includes a right frame and a right guide rod 223, the right frame is provided with a right guide hole along the left-right direction X, the right guide rod 223 is inserted in the right guide hole and is fixedly connected to the right pressing plate 222. In this embodiment, when the left pressing plate 212 slides along the left-right direction X, the left guide rod 213 is driven to slide in the left guide hole. Therefore, the left guide rod 213 slides in the left guide hole, which can ensure the stable sliding of the left pressing plate 212 in the left-right direction X on the one hand, and can prevent the left pressing plate 212 from rotating around the driving shaft of the left driving member 211 on the other hand. The left driving member 211 is arranged on the left frame. The structure of the right frame and the right guide rod 223 is the same as that of the left frame and the left guide rod 213, and will not be repeated here.

[0045] Optionally, at least two left guide rods 213 are provided, at least two left guide holes are provided on the left frame, and at least two left guide rods 213 are inserted into the at least two left guide holes in a one-to-one correspondence; at least two right guide rods 223 are provided, at least two right guide holes are provided on the right frame, and at least two right guide rods 223 are inserted into the at least two right guide holes in a one-to-one correspondence. In this embodiment, the above arrangement can further ensure the stability of the left pressure plate 212 sliding relative to the left frame along the left-right direction X, and ensure the stability of the right pressure plate 222 sliding relative to the right frame along the left-right direction X.

[0046] Optionally, a surface of the left web 100 away from the right web 200 is provided with a stepped structure, and a surface of the right web 200 away from the left web 100 is provided with a stepped structure; the left tightening assembly 21 also includes a plurality of left abutting blocks 214, which are arranged on the side of the left pressure plate 212 opposite to the left web 100 and have different thicknesses along the left-right direction X, and the plurality of left abutting blocks 214 respectively abut against the stepped structure on the left web 100 to make the left pressure plate 212 parallel to the left web 100; the right tightening assembly 22 also includes a plurality of right abutting blocks 224, which are arranged on the side of the right pressure plate 222 opposite to the right web 200 and have different thicknesses along the left-right direction X, and the plurality of right abutting blocks 224 respectively abut against the stepped structure on the right web 200 to make the right pressure plate 222 parallel to the right web 200. In this embodiment, since the left web 100 is provided with a stepped structure, if the left driving member 211 directly drives the left pressure plate 212 to be attached to the left web 100, the left pressure plate 212 cannot be completely attached to the left web 100, which easily causes the left web 100 to tilt relative to the right web 200, which is not conducive to the positioning and assembly of the excavator arm. Therefore, a plurality of left abutting blocks 214 with different thicknesses along the left and right directions X are provided on the left pressure plate 212, so that when the left abutting block 214 is attached to the left web 100, the left pressure plate 212 and the left web 100 are parallel to each other, which is conducive to pushing the left web 100 close to the right web 200. The structure of the right web 200 and the right abutting block 224 is the same as that of the left web 100 and the left abutting block 214, and will not be repeated here.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Excavator arm inner cavity assembly spacing control tooling, characterized in that: include: A positioning mandrel (1), the positioning mandrel (1) being used to be arranged between the left web (100) and the right web (200), the length of the positioning mandrel (1) being equal to the designed spacing between the left web (100) and the right web (200); A clamping mechanism (2), the clamping mechanism (2) is used to drive the left web (100) and the right web (200) to move in a direction approaching each other, so that the left web (100) and the right web (200) are respectively abutted against the two ends of the positioning push rod (1) and the left web (100) and the right web (200) are respectively abutted against the two connecting parts of the support seat (300) along the left-right direction (X).

2. The excavator arm inner cavity assembly spacing control tooling according to claim 1 is characterized in that: The positioning push rod (1) comprises a rod portion (11) and a telescopic portion (12) arranged at one end or both ends of the rod portion (11) along the left-right direction (X); the telescopic portion (12) can be telescoped relative to the rod portion (11) along the left-right direction (X).

3. The excavator arm inner cavity assembly spacing control tooling according to claim 2 is characterized in that: A threaded hole is recessed at a position where the rod (11) and the telescopic part (12) are opposite to each other, and the telescopic part (12) extends into the threaded hole and is threadedly connected to the rod (11).

4. The excavator arm inner cavity assembly spacing control tooling according to claim 2 is characterized in that: The positioning push rod (1) also includes a hanging ear (13), the hanging ear (13) is fixedly connected to the rod portion (11), and the hanging ear (13) is mounted on the left web (100) and / or the right web (200) so that the rod portion (11) is respectively perpendicular to the left web (100) and the right web (200).

5. The excavator arm inner cavity assembly spacing control tooling according to claim 4 is characterized in that: The hanging ear (13) comprises a lap rod (131) and a connecting rod (132), one end of the connecting rod (132) is fixedly connected to the rod portion (11), and the other end of the connecting rod (132) is fixedly connected to the middle part of the lap rod (131), and the two ends of the lap rod (131) are respectively lapped on the left web (100) and the right web (200) and are respectively perpendicular to the left web (100) and the right web (200), so that the rod portion (11) is located between the left web (100) and the right web (200) and is respectively perpendicular to the left web (100) and the right web (200).

6. The excavator arm inner cavity assembly spacing control tooling according to claim 1 is characterized in that: The clamping mechanism (2) comprises a left clamping assembly (21) and a right clamping assembly (22); the left clamping assembly (21) is arranged on a side of the left web plate (100) away from the right web plate (200) and pushes the left web plate (100) towards the right web plate (200); and the right clamping assembly (22) is arranged on a side of the right web plate (200) away from the left web plate (100) and pushes the right web plate (200) towards the left web plate (100).

7. The excavator arm inner cavity assembly spacing control tooling according to claim 6 is characterized in that: The left pressing assembly (21) comprises a left driving member (211) and a left pressing plate (212), wherein the left driving member (211) drives the left pressing plate (212) to move along the left-right direction (X) and pushes the left web plate (100) to move in a direction close to the right web plate (200); The right tightening assembly (22) comprises a right driving member (221) and a right pressure plate (222), wherein the right driving member (221) drives the right pressure plate (222) to move along the left-right direction (X) and pushes the right web plate (200) to move in a direction close to the left web plate (100).

8. The excavator arm inner cavity assembly spacing control tooling according to claim 7 is characterized in that: The left tightening assembly (21) further comprises a left frame and a left guide rod (213); the left frame is provided with a left guide hole along the left-right direction (X); the left guide rod (213) is inserted into the left guide hole and is fixedly connected to the left pressure plate (212); The right tightening assembly (22) further comprises a right frame body and a right guide rod (223); the right frame body is provided with a right guide hole along the left-right direction (X); the right guide rod (223) is inserted into the right guide hole and fixedly connected to the right pressure plate (222).

9. The excavator arm inner cavity assembly spacing control tooling according to claim 8, characterized in that: At least two left guide rods (213) are provided, at least two left guide holes are provided on the left frame, and at least two left guide rods (213) are inserted into the at least two left guide holes in a one-to-one correspondence; At least two right guide rods (223) are provided, at least two right guide holes are provided on the right frame, and at least two right guide rods (223) are inserted into the at least two right guide holes in a one-to-one correspondence.

10. The excavator arm inner cavity assembly spacing control tooling according to claim 8, characterized in that: The surface of the left web (100) away from the right web (200) is provided with a stepped structure, and the surface of the right web (200) away from the left web (100) is provided with a stepped structure; The left tightening assembly (21) further comprises a plurality of left abutting blocks (214), the plurality of left abutting blocks (214) being arranged on a side of the left pressure plate (212) opposite to the left web plate (100) and having different thicknesses along the left-right direction (X), the plurality of left abutting blocks (214) respectively abutting against the stepped structures on the left web plate (100) so that the left pressure plate (212) is parallel to the left web plate (100); The right clamping assembly (22) also includes a plurality of right abutment blocks (224), which are arranged on the side of the right pressure plate (222) opposite to the right web plate (200) and have different thicknesses along the left-right direction (X). The plurality of right abutment blocks (224) respectively abut against the stepped structure on the right web plate (200) to make the right pressure plate (222) parallel to the right web plate (200).

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