CN117102638A

CN117102638A - Swing arm cover plate splice welding method and swing arm for engineering machinery

Info

Publication number: CN117102638A
Application number: CN202311165967.0A
Authority: CN
Inventors: 袁勇; 李紫璇; 叶东旭; 颜鹏
Original assignee: Zoomlion Earth Moving Machinery Co Ltd; Shaanxi Zoomlion West Earthmoving Machinery Co Ltd
Current assignee: Zoomlion Earth Moving Machinery Co Ltd; Shaanxi Zoomlion West Earthmoving Machinery Co Ltd
Priority date: 2023-09-11
Filing date: 2023-09-11
Publication date: 2023-11-24

Abstract

The application belongs to the technical field of engineering machinery, and discloses a movable arm cover plate welding method and a movable arm for engineering machinery. Therefore, the movable arm cover plate splice welding method disclosed by the application saves the time for processing the arc starting plate and the arc receiving plate and assembling the arc starting plate and the arc receiving plate, and improves the production efficiency. The welding seam at the arc starting and arc receiving positions is better in molding, and the quality of the welding seam is improved. And the arc starting and receiving positions have good heat conductivity, the thermal field is uniform, and the welding seam is not easy to form cold brittleness.

Description

Swing arm cover plate splice welding method and swing arm for engineering machinery

Technical Field

The application relates to the technical field of engineering machinery, in particular to a movable arm cover plate splice welding method and a movable arm for engineering machinery.

Background

The boom of an excavator is typically constructed in a box-like configuration surrounded by upper and lower cover plates and left and right webs. Wherein the upper and lower cover plates and the left and right webs are formed by multi-section splice welding. The upper cover plate and the lower cover plate are stressed most severely and mainly bear tensile and compressive stress caused by bending moment. The upper cover plate and the lower cover plate are required to be provided with V-shaped grooves during welding so as to form full penetration welding seams. The quality of the welding is directly related to whether the welding seam can generate cracking failure or not.

The movable arm of the excavator is generally required to be designed with a variable cross section according to the stress characteristics, and meanwhile, the thickness of the part is required to be butted with thick sheets according to the stress. The construction of the boom is therefore typically designed as a multi-segment box splice (typically three-segment). The upper cover plate and the lower cover plate are required to be provided with V-shaped grooves during welding so as to form a full penetration welding line. Wherein, the butt welding seam is easy to have more defects such as air holes, inclusions, arc pit cracks and the like due to current change and unstable heat transfer at the arc starting and arc receiving positions during welding. If the arc striking and the arc striking plate are not arranged, the fatigue crack is easy to be a weak point.

At present, in order to obtain stable welding quality in the existing movable arm manufacturing process, special arc striking plates with V-shaped grooves, arc receiving plates (usually made of ceramic materials) and steel backing plates are usually adopted for butt welding of upper and lower cover plates before welding, and the butt welding plates are clamped to the edges of the large plates by clamps. The arc striking plate and the arc receiving plate are assembled in the mode, time is wasted, looseness is easy, the quality of a welding seam of the joint is easy to be affected by assembly errors of the arc striking plate and the arc receiving plate, and therefore welding quality cannot be guaranteed.

Disclosure of Invention

The application aims to provide a movable arm cover plate splice welding method and a movable arm for engineering machinery, which are used for solving the defects in the prior art.

To achieve the above object, in a first aspect, the present application provides a method for welding a boom cover, including:

preparing a baseplate for splice welding, reserving lugs at two ends of a to-be-welded edge of the baseplate, and enabling the side edges of the lugs to be level with the to-be-welded edge;

machining the edges to be welded into slopes so that two ends of the slopes extend to the lugs;

abutting the edges to be welded of the two substrates together to form a welding groove;

welding backing plates on the bottom surfaces of the two lugs on the same side of the two base plates respectively;

performing welding operation, namely striking arcs on two lugs on one side of the two substrates and striking arcs on the two lugs on the other side along the length direction of the welding groove;

the lugs and the backing plate are removed.

As a further improvement of the above technical scheme:

with reference to the first aspect, in one possible implementation manner, the lug and the substrate are in an integrally formed structure, and a thickness of the lug is consistent with a thickness of the substrate.

With reference to the first aspect, in one possible implementation manner, the length of the lug along the edge to be welded is a, and the total width of two lugs perpendicular to the edge to be welded is b;

wherein a is more than or equal to 25mm plus or minus 5mm, b is more than or equal to 0.8 x t+15 and less than or equal to 30mm plus or minus 5mm, and t is the thickness of the lug.

With reference to the first aspect, in one possible implementation manner, a side edge of the base plate perpendicular to the edge to be welded and the corresponding lug are transited by a fillet, and the radius R of the fillet is equal to or greater than 5mm plus or minus 1mm.

With reference to the first aspect, in one possible implementation manner, a bevel angle formed by the welding groove is greater than or equal to 45 °, and a root gap of the welding groove is 4mm±1mm.

With reference to the first aspect, in one possible implementation manner, the bevel angle is greater than or equal to 45 ° and less than or equal to 50 °.

With reference to the first aspect, in one possible implementation manner, a cross-sectional profile of the welding groove is V-shaped or Y-shaped.

With reference to the first aspect, in a possible implementation manner, the lug and the backing plate are removed by cutting, and the cut surface is polished to be flat.

With reference to the first aspect, in a possible implementation manner, the backing plate is a steel backing plate, and the thickness of the steel backing plate is 6 mm-10 mm, the width is 25mm±5mm, and the length is greater than 50mm.

In order to achieve the above object, in a second aspect, the present application further provides a boom for engineering machinery, including an upper cover plate, a lower cover plate, and side webs disposed on both sides of the upper cover plate and the lower cover plate;

the upper cover plate and/or the lower cover plate are/is manufactured by adopting the movable arm cover plate splice welding method provided by the first aspect.

Compared with the prior art, the application has the beneficial effects that:

the application provides a movable arm cover plate welding method and a movable arm for engineering machinery, wherein the movable arm cover plate welding method adopts a substrate with lugs, and a slope extending to the lugs is processed on the edge to be welded of the substrate, so that a welding groove is formed when two substrates are butt-jointed and welded, when welding operation is carried out, arc starting can be carried out directly from two lugs on one side of the two substrates to arc receiving can be carried out on two lugs on the other side, and after welding is completed, the lugs and a backing plate are removed. Therefore, the movable arm cover plate splice welding method provided by the application can be used for directly starting and receiving arcs on the lugs on the base plate, thereby replacing the special arc starting plate and arc receiving plate structures in the prior art, saving the time for processing the arc starting plate and the arc receiving plate and assembling the arc starting plate and the arc receiving plate, and improving the production efficiency.

Furthermore, because the arc can be directly started and received on the lug of the base plate when welding, compared with the special arc starting plate and receiving plate structure which are assembled on site in the prior art, the welding seam forming at the arc starting and receiving positions is better, and the welding seam quality is improved. And the arc starting and receiving positions have good heat conductivity, the thermal field is uniform, and the welding seam is not easy to form cold brittleness.

Additional features and advantages of the application will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate only certain embodiments of the application and, therefore, should not be considered as limiting the scope, since it is possible to obtain other related drawings from the drawings without inventive step by those of ordinary skill in the art. In the drawings:

FIG. 1 shows a flow chart of a boom cover splice welding method provided by an embodiment of the application;

fig. 2 is a schematic diagram showing an arrangement state of two substrates in butt-joint welding in a movable arm cover plate welding method according to an embodiment of the present application;

FIG. 3 shows a cross-sectional view in the direction A-A of FIG. 2;

FIG. 4 is a schematic diagram of a partial mechanism of a movable arm upper cover plate for engineering machinery, which is provided by the embodiment of the application and is not removed with lugs after splice welding;

fig. 5 shows a schematic perspective view of a boom for engineering machinery according to an embodiment of the present application;

fig. 6 is a schematic perspective view showing another view of the boom for construction machine shown in fig. 5.

Reference numerals illustrate:

100. a substrate; 101. a lug; 102. welding edges; 103. a slope; 110. welding grooves; 120. a backing plate;

200. an upper cover plate;

300. a lower cover plate;

400. and a side web.

Detailed Description

The following describes the detailed implementation of the embodiments of the present application with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the application, are not intended to limit the application.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

In the embodiments of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The application will be described in detail below with reference to the drawings in connection with exemplary embodiments.

Examples

Referring to fig. 1 to 6, the present embodiment provides a method for welding a boom cover plate, which can be used to manufacture an upper cover plate 200 and a lower cover plate 300 (hereinafter also referred to as cover plates) of a boom in a construction machine.

Referring to fig. 1, 2, 3 and 4, in the present embodiment, the welding method of the boom cover plate includes the following steps:

s100: a substrate 100 for splice welding is prepared, lugs 101 are reserved at both ends of a side 102 to be welded of the substrate 100, and the side edges of the lugs 101 are made flush with the side 102 to be welded.

The movable arm cover plate is generally formed by splicing and welding a plurality of base plates 100, the cover plate is generally designed with a variable cross section according to the stress characteristics of the movable arm, and meanwhile, the thickness of the part of the cover plate is required to be in butt joint with thick thin plates according to the stress. Thus, the number of substrates 100 prepared in the present embodiment depends on the size and design requirements of the cover plate, and is not particularly limited in the present embodiment. Meanwhile, the thickness of the substrate 100 prepared in this embodiment is also designed according to the stress.

In this embodiment, the lug 101 and the substrate 100 are integrally formed, wherein the thickness of the lug 101 is consistent with that of the substrate 100, so that the lug 101 can conduct heat uniformly during welding, the thermal field is uniform, and the quality of the welding seam is ensured.

S200: the edge 102 to be welded is machined into the sloping surface 103 such that both ends of the sloping surface 103 extend onto the lugs 101. It will be appreciated that the location at which the ramp 103 extends over the lug 101 may be set based on the size of the lug 101 along the length of the edge 102 to be welded and the welding requirements (ensuring that there is sufficient distance to provide arcing and arc starting for subsequent welds).

Further, in order to save material consumption, the dimension of the lug 101 in the length direction of the edge 102 to be welded meets the requirements of subsequent welding arcing and arc receiving, and simultaneously, the forming of the lug 101 on the substrate 100 is facilitated. Thus, both ends of the slope 103 extend to the end faces of the lugs 101 in the length direction of the edges 102 to be welded.

S300: the edges 102 to be welded of the two substrates 100 are brought together to form a weld groove 110. Wherein the gap between the two substrates 100 is set according to the soldering requirement.

In this embodiment, the welding groove 110 forms a bevel angle C of 45 ° or more, and the root gap L of the welding groove 110 is 4mm±1mm. It can be understood that the root gap L is favorable for penetration of the root of the backing weld, too small a gap affects penetration of the root of the backing weld, and too large a gap increases the welding quantity.

Alternatively, the root gap L of the weld groove 110 may also be selected to be 3.2mm, 3.5mm, 3.8mm, 3.9mm, 4.2mm, 4.5mm, 4.6mm, 4.8mm, or 4.9mm. It is to be understood that the foregoing is illustrative only and is not to be construed as limiting the scope of the application.

In some embodiments, the bevel angle C is greater than or equal to 45 ° and less than or equal to 50 °.

Alternatively, the bevel angle C may also be selected to be 45.1 °, 45.5 °, 46 °, 46.2 °, 46.8 °, 47 °, 47.1 °, 47.4 °, 47.9 °, 48.1 °, 48.5 °, 48.8 °, 49 °, 49.5 °, or 49.8 °. It is to be understood that the foregoing is illustrative only and is not to be construed as limiting the scope of the application.

In this embodiment, the welding groove 110 is Y-shaped along the cross-sectional profile perpendicular to the edge 102 to be welded, so as to ensure that a completely penetration welded joint can be obtained after welding, and the weld joint has good bearing capacity.

In some embodiments, weld groove 110 is V-shaped along a cross-sectional profile perpendicular to edge 102 to be welded, thereby ensuring that a completely penetration weld joint is obtained after welding, and that the weld has good load carrying capacity.

The length of the lug 101 along the edge 102 to be welded is a, and the total width of two lugs 101 perpendicular to the edge 102 to be welded is b; wherein a is more than or equal to 25mm plus or minus 5mm, b is more than or equal to 0.8 x t+15 and less than or equal to 30mm plus or minus 5mm, and t is the thickness of the lug 101. Thereby facilitating blanking of the base plate 100 with lugs 101 while simultaneously machining the ramps 103 on the lugs 101 for convenience.

Further, the substrate 100 is in transition with the corresponding lug 101 through a fillet between one side edge perpendicular to the edge 102 to be welded, wherein the radius R of the fillet is more than or equal to 5mm plus or minus 1mm. Preferably 5mm.

S400: backing plates 120 are welded to the bottom surfaces of the two lugs 101 on the same side of the two substrates 100, respectively.

It can be appreciated that the two substrates 100 can be relatively fixed and positioned by spot welding the backing plates 120 on the bottom surfaces of the two lugs 101, so that deviation in the welding process is avoided, and the quality of welding seams is ensured. In this embodiment, the backing plate 120 is fixed by spot welding, which facilitates subsequent removal.

In this embodiment, the backing plate 120 is a steel backing plate 120, and the steel backing plate 120 is used to facilitate spot welding with the substrate 100.

Alternatively, the steel backing plate 120 has a thickness of 6mm to 10mm, a width of 25mm + -5 mm, and a length of greater than 50mm.

S500: the welding operation is performed by striking an arc from the two lugs 101 on one side of the two substrates 100 and striking an arc from the two lugs 101 on the other side along the longitudinal direction of the welding groove 110.

S600: the lugs 101 and the backing plate 120 are removed.

Wherein removing the lugs 101 and the backing plate 120 comprises: the lugs 101 and the backing plate 120 are removed by cutting and the cut surface is polished flat.

The cutting mode can be selected from cutting sheet cutting or flame cutting. When polishing, an angle grinder or a grinder can be adopted for primary polishing, and then finer sand can be replaced for polishing and flattening.

Compared with the prior art, the movable arm cover plate welding method provided by the embodiment adopts the base plate 100 with the lug 101, and the slope 103 extending to the lug 101 is processed on the edge 102 to be welded of the base plate 100, so that the welding groove 110 is formed when the two base plates 100 are butt-jointed and welded. During welding, the two lugs 101 on one side of the substrate 100 may be directly struck from the two lugs 101 on the other side to strike the two lugs 101 on the other side, and after welding, the lugs 101 and the backing plate 120 are removed. Therefore, the movable arm cover plate welding method provided by the embodiment can directly generate and receive arcs on the lugs 101 on the base plate 100, thereby replacing the special arc generating plate and arc receiving plate structure in the prior art, saving the time for processing the arc generating plate and the arc receiving plate and assembling the arc generating plate and the arc receiving plate, and improving the production efficiency.

Furthermore, because the arc can be directly started and received on the lug 101 of the base plate 100 during welding, compared with the special arc starting plate and receiving plate structure which are assembled on site in the prior art, the welding seam forming at the arc starting and receiving positions is better, and the welding seam quality is improved. And the arc starting and receiving positions have good heat conductivity, the thermal field is uniform, and the welding seam is not easy to form cold brittleness.

Referring to fig. 4, 5 and 6, the present embodiment also provides a boom for a construction machine. The boom for construction machinery includes an upper cover plate 200, a lower cover plate 300, and side webs 400 provided on both sides of the upper cover plate 200 and the lower cover plate 300.

The upper cover plate 200, the lower cover plate 300 and the side webs 400 on two sides are welded. Wherein, the upper cover plate 200, the lower cover plate 300 and the side webs 400 on both sides are all formed by splice welding of three base plates 100. In addition, in the present embodiment, the upper cover plate 200 and the lower cover plate 300 are manufactured by the above-mentioned movable arm cover plate welding method.

Of course, in some embodiments, the upper cover plate 200 or the lower cover plate 300 may be manufactured by the above-provided movable arm cover plate welding method.

In other embodiments, the side webs 400 on both sides may also be formed using the boom deck splice welding method provided above.

Optionally, the work machine is an excavator.

It should be noted that, the application scenario of the embodiment is mainly aimed at gas shielded welding of low-alloy high-strength structural steel.

Therefore, the movable arm for the engineering machinery can bear tensile and compressive stress caused by larger bending moment, and is better in structural strength and longer in service life.

The foregoing details of the optional implementation of the embodiment of the present application have been described in detail with reference to the accompanying drawings, but the embodiment of the present application is not limited to the specific details of the foregoing implementation, and various simple modifications may be made to the technical solution of the embodiment of the present application within the scope of the technical concept of the embodiment of the present application, and these simple modifications all fall within the protection scope of the embodiment of the present application.

In addition, the specific features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

In addition, any combination of various embodiments of the present application may be performed, so long as the concept of the embodiments of the present application is not violated, and the disclosure of the embodiments of the present application should also be considered.

Claims

1. A boom cover splice welding method, comprising:

preparing a baseplate (100) for splice welding, reserving lugs (101) at two ends of a side (102) to be welded of the baseplate (100), and enabling the side edges of the lugs (101) to be flush with the side (102) to be welded;

machining the edges (102) to be welded into sloping surfaces (103) so that both ends of the sloping surfaces (103) extend onto the lugs (101);

abutting and closing the edges (102) to be welded of the two substrates (100) to form a welding groove (110);

a backing plate (120) is welded on the bottom surfaces of the two lugs (101) on the same side of the two base plates (100);

performing welding operation, namely striking arcs on two lugs (101) on one side of the two substrates (100) and striking arcs on the two lugs (101) from the length direction of the welding groove (110) to the other side;

-removing the lugs (101) and the backing plate (120).

2. The boom cover splice welding method according to claim 1, characterized in that the lug (101) is of an integrally formed structure with the base plate (100), and the thickness of the lug (101) is identical to the thickness of the base plate (100).

3. The boom cover panel splice welding method according to claim 1, characterized in that the length of the lugs (101) along the edge (102) to be welded is a, and the total width of two lugs (101) perpendicular to the edge (102) to be welded is b;

wherein a is more than or equal to 25mm plus or minus 5mm, b is more than or equal to 0.8 x t+15 and less than or equal to 30mm plus or minus 5mm, and t is the thickness of the lug (101).

4. The movable arm cover plate welding method according to claim 1, wherein one side of the base plate (100) perpendicular to the edge (102) to be welded and the corresponding lug (101) are transited by a fillet, and the radius R of the fillet is more than or equal to 5mm plus or minus 1mm.

5. The boom cover splice welding method according to claim 1, wherein a bevel angle formed by the welding groove (110) is greater than or equal to 45 °, and a root gap of the welding groove (110) is 4mm ± 1mm.

6. The boom cover splice welding method of claim 5, wherein the bevel angle is greater than or equal to 45 ° and less than or equal to 50 °.

7. The boom cover panel splice welding method of claim 1, wherein the cross-sectional profile of the weld groove (110) is V-shaped or Y-shaped.

8. The boom cover panel splice welding method according to claim 1, characterized in that the lugs (101) and the backing plate (120) are removed by cutting and the cut surface is polished flat.

9. The boom cover panel splice welding method according to any one of claims 1 to 8, characterized in that the shim plate (120) is a steel shim plate (120), the thickness of the steel shim plate (120) is 6mm to 10mm, the width is 25mm ± 5mm, and the length is greater than 50mm.

10. The movable arm for the engineering machinery is characterized by comprising an upper cover plate (200), a lower cover plate (300) and side webs (400) arranged on two sides of the upper cover plate (200) and the lower cover plate (300);

wherein the upper cover plate (200) and/or the lower cover plate (300) are manufactured by adopting the movable arm cover plate welding method according to any one of claims 1-9.