Additive manufacturing equipment for machining anchor main rod

Abstract

The invention belongs to the field of anchor machining, and particularly relates to additive manufacturing equipment for machining an anchor main rod, the additive manufacturing equipment comprises a laser operation mechanism and a laser cladding seat, the laser cladding seat comprises a rack, a base, a base rod and a driving mechanism, the driving mechanism comprises an oscillation shaft and a crankshaft, the oscillation shaft comprises a shaft belly, an upper shaft section and a lower shaft section, and an oscillation cavity is formed in the shaft belly; and an irregular eccentric spherical object is arranged in the oscillation cavity. According to the invention, the crankshaft and the oscillation shaft are additionally arranged to cooperate with each other, and high-frequency vibration is applied to the foot margin main rod which is being subjected to material addition, so that the foot margin main rod after material addition is more compact in structure and fewer in hole defect and crack defect, the tensile strength of the foot margin main rod is improved, and particularly, the torsional strength of the foot margin main rod can be remarkably improved, so that the foot margin main rod meets the construction requirements; in addition, the stability of the equipment is good, and the consistency of the anchor main rod manufactured through additive manufacturing is high.

Description

Technical Field

[0001] This invention belongs to the field of foundation processing technology, specifically relating to an additive manufacturing equipment for processing foundation main rods. Background Technology

[0002] Additive manufacturing has attracted widespread attention due to its ability to rapidly manufacture complex structures. However, despite its significant advantages in material utilization, design freedom, and manufacturing efficiency, additive manufacturing still suffers from various defects. These defects not only affect the mechanical properties of the manufactured parts but may also lead to structural failure, thus limiting its application in critical fields. The following section will analyze in detail the types of defects in additive manufacturing and their causes from multiple perspectives.

[0003] I. Common Defect Types in Additive Manufacturing

[0004] 1. Hole defects

[0005] Pore ​​defects are among the most common defects in additive manufacturing, especially in the fabrication of metals and composite materials. The formation of voids is typically closely related to the melting, solidification, and cooling processes of the material. In metal additive manufacturing, void formation may originate from gases in the powder material, insufficient gas escape rates during molten pool solidification, and inert gases entrained during the melting process. In fiber-reinforced composites, void defects are mainly caused by air trapping during fiber impregnation or layer-by-layer accumulation. Void defects significantly reduce the density and mechanical properties of the material, and are particularly prone to becoming crack initiation points under high temperature or high stress conditions.

[0006] 2. Crack defects

[0007] Cracks are among the most destructive defects in additive manufacturing. Cracks can be classified into two types: hot cracks and cold cracks. Hot cracks typically occur during the rapid cooling of the molten pool, where the tensile stress generated by solidification shrinkage exceeds the material's strength limit, leading to crack formation. Cold cracks, on the other hand, are mainly caused by residual stress accumulated during multi-layer forming. When this stress exceeds the material's plasticity limit, cracks form within the material. The presence of cracks significantly reduces the material's fatigue performance and structural integrity, and may even lead to the failure of the entire component.

[0008] These defects reduce tensile strength, especially for metal rods. Once holes and cracks reach a certain level, the torsional strength of the metal rod will drop drastically. This is detrimental to the application of special-purpose anchors.

[0009] Based on this, the present invention is proposed. Summary of the Invention

[0010] The purpose of this invention is to provide an additive manufacturing equipment for processing anchor rods, so as to solve the above-mentioned problems.

[0011] An additive manufacturing equipment for processing anchor rods includes a laser processing mechanism and a laser cladding base. The laser cladding base includes a frame, a base, a base rod located at the center of the base, and a drive mechanism for driving the base rod to rotate. The drive mechanism includes an oscillating shaft and a crankshaft coaxially connected to the base rod. The oscillating shaft includes a shaft belly, an upper shaft section integrally connected to the shaft belly, and a lower shaft section threadedly connected to the shaft belly. An oscillating cavity is provided inside the shaft belly, and an irregular eccentric spherical object is provided inside the oscillating cavity. The lower shaft section is coaxially connected to the crankshaft.

[0012] A further improvement is made by installing a buffer bearing between the crankshaft and the frame.

[0013] In a further improvement, the lower part of the shaft is provided with a threaded hole that communicates with the oscillation cavity, and a locking nut is sleeved on the outside of the lower shaft section, and the locking nut is threadedly connected to the lower shaft section.

[0014] In a further improvement, the irregularly eccentric spherical object is made of lead or a lead alloy.

[0015] In a further improvement, the oscillation cavity includes a semi-ellipsoidal unit and a semi-spherical unit, the semi-ellipsoidal unit being located above the semi-spherical unit and interconnected with each other, and the major axis of the semi-ellipsoidal unit being equal to the diameter of the semi-spherical unit.

[0016] As a further improvement, the oscillation chamber is filled with lubricating oil.

[0017] In a further improvement, the ratio of the volume of the irregular eccentric sphere to the effective volume of the oscillation cavity is 0.23.

[0018] In a further improvement, the top end of the base rod is provided with a tapered hole, the taper of which is 2.5° to 5°.

[0019] In a further improvement, a rotating hole is provided in the center of the base, and the base rod and the rotating hole are fitted with a clearance fit.

[0020] As a further improvement, the base is equipped with a vacuum cleaner for vacuuming the rotating holes.

[0021] Compared with the prior art, the beneficial effects of this invention are as follows:

[0022] This invention applies high-frequency vibration to the additive-manufactured anchor rod by adding a crankshaft and an oscillating shaft, resulting in a denser structure with fewer pores and cracks, thus improving the tensile strength of the anchor rod and, in particular, significantly enhancing its torsional strength to meet construction requirements. Furthermore, the equipment exhibits good stability, leading to high consistency in the additive-manufactured anchor rods. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the additive manufacturing equipment for processing the main anchor rod according to the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the oscillation shaft described in this invention;

[0025] Figure 3 It is the curve trend of x-value versus variance of torsional strength. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0027] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Example 1

[0030] like Figure 1 , 2As shown, an additive manufacturing equipment for processing anchor rods includes a laser processing mechanism and a laser cladding base. The laser cladding base includes a frame 10, a base 20, a base rod 30 located at the center of the base 20, and a drive mechanism for driving the base rod 30 to rotate. The drive mechanism includes an oscillating shaft and a crankshaft 12 coaxially connected to the base rod 30. The oscillating shaft includes a shaft belly 51, an upper shaft section 54 integrally connected to the shaft belly 51, and a lower shaft section 53 threadedly connected to the shaft belly 51. An oscillating cavity 55 is provided inside the shaft belly 51, and an irregularly eccentric spherical object 52 is provided inside the oscillating cavity 55. The lower shaft section 53 is coaxially connected to the crankshaft 12.

[0031] Using the base rod 30 as a carrier, the laser operation mechanism begins additive manufacturing of the main anchor rod in front of the base rod 30. During the additive manufacturing process, the base rod 30 is always rotating, and its rotation speed changes at any time according to the process requirements.

[0032] The torsional strength of a conventionally forged Q235 anchor rod is 16.3 MPa, and its tensile strength is 437 MPa. However, when Q235 steel is manufactured using conventional additive manufacturing, the torsional strength is 7.1 MPa, and the tensile strength is 375 MPa.

[0033] In this invention, during the rotation of the base rod 30, under the action of the crankshaft 12, there is a certain eccentricity. The resulting centrifugal force generates a small-amplitude excitation, which causes the irregular eccentric spherical object 52 to continuously impact within the oscillation cavity 55. The irregular eccentric spherical object 52 refers to the surface of the eccentric ball being further processed into an irregular, uneven surface, so that under the action of the centrifugal force of the excitation, it can more randomly strike the oscillation cavity 55. The resulting striking force, combined with the excitation force generated by the centrifugal force, has a dual effect, thereby providing a continuous high-frequency force to the molten material that is being additively processed. This helps to expel air bubbles, form a denser structure, and help reduce pore defects and crack defects. As a result, the torsional strength can reach 11.3 MPa (an increase of 59.2%), and the tensile strength can reach 422 MPa (an increase of 12.5%).

[0034] The torsional strength consistency evaluation involves measuring the torsional strength of the same batch of additively manufactured anchor rods and calculating the variance of the torsional strength.

[0035] In this embodiment, the variance of the torsional strength is 0.24, which is small and indicates high consistency.

[0036] Example 2

[0037] To further reduce wear, a buffer bearing 11 is installed between the crankshaft 12 and the frame 10. A buffer bearing is a device used to reduce mechanical vibration and impact.

[0038] Example 3

[0039] To further facilitate assembly, the lower part of the shaft belly 51 is provided with a threaded hole that communicates with the oscillation cavity 55, and a locking nut 56 is sleeved on the outside of the lower shaft section 53, and the locking nut 56 is threadedly connected to the lower shaft section 53.

[0040] Example 4

[0041] A rotating hole is provided in the center of the base 20, and the base rod 30 is clearance-fitted with the rotating hole. A vacuum cleaner for vacuuming the rotating hole is provided inside the base 20.

[0042] In this way, the dust falling during the additive manufacturing process can be removed in time, avoiding the accumulation of dust in the gap between the base rod 30 and the rotating hole, which could lead to seizing.

[0043] Example 5

[0044] The irregular eccentric spherical object 52 is made of lead or a lead alloy.

[0045] The oscillation cavity 55 includes a semi-ellipsoidal unit 552 and a semi-spherical unit 551. The semi-ellipsoidal unit 552 is located above the semi-spherical unit 551 and is interconnected with it. The major axis of the semi-ellipsoidal unit 552 is equal to the diameter of the semi-spherical unit 551.

[0046] To further reduce wear, the oscillation chamber 55 is filled with lubricating oil.

[0047] The ratio of the volume of the irregular eccentric spherical object 52 to the effective volume of the oscillation cavity 55 is x, preferably x = 0.23.

[0048] The effective volume of the oscillation cavity 55 refers to the volume inside the oscillation cavity 55 when the upper end of the lower shaft section 53 just touches the junction of the screw hole and the hemispherical unit 551.

[0049] If the oscillation cavity 55 is spherical and all other parts are the same, the torsional strength (maximum value) can reach 8.5 MPa and the tensile strength (maximum value) can reach 413 MPa.

[0050] If the oscillation cavity 55 is ellipsoidal, and all other parts are the same, the torsional strength (maximum value) can reach 8.1 MPa, and the tensile strength (maximum value) can reach 409 MPa.

[0051] If the irregular eccentric spherical object 52 is replaced with an eccentric sphere, and all other parameters remain the same, the torsional strength (maximum value) can reach 7.7 MPa, and the tensile strength (maximum value) can reach 393 MPa.

[0052] If the irregular eccentric spherical object 52 is replaced with a sphere, and everything else remains the same, the torsional strength (maximum value) can reach 7.4 MPa, and the tensile strength (maximum value) can reach 385 MPa.

[0053] If the shaft 51 is solid and there is no irregular eccentric spherical part 52, and all other parts are the same, the torsional strength (maximum value) can reach 7.5MPa and the tensile strength (maximum value) can reach 388MPa.

[0054] If crankshaft 12 is not installed, all other parameters are the same, and the torsional strength (maximum) can reach 7.2 MPa, and the tensile strength (maximum) can reach 381 MPa.

[0055] As can be seen from the above, although adding a crankshaft or setting an irregular eccentric spherical object 52 can slightly improve the tensile strength, the improvement in torsional strength is very limited.

[0056] When the value of x changes, it is found that it has little effect on the torsional strength (maximum value) and tensile strength (maximum value), but mainly affects the variance of the torsional strength, as shown in the curve. Figure 3 ,Depend on Figure 3 It can be seen that x is preferably 0.23.

[0057] Example 6

[0058] The base rod 30 can be used directly as a carrier for additive manufacturing, or a female anchor rod can be inserted into the base rod 30. The female anchor rod is inserted into a tapered hole at the top of the base rod 30, with a taper of 2.5° to 5°. Then, an interference fit is achieved by hammering to complete the connection. After additive manufacturing is completed, it can be removed.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An additive manufacturing equipment for processing anchor rods, comprising a laser processing mechanism and a laser cladding base, wherein the laser cladding base comprises a frame (10), a base (20), a base rod (30) located at the center of the base (20), and a drive mechanism for driving the base rod (30) to rotate, characterized in that: The drive mechanism includes an oscillating shaft and a crankshaft (12) coaxially connected to the base rod (30). The oscillating shaft includes a shaft belly (51), an upper shaft section (54) integrally connected to the shaft belly (51), and a lower shaft section (53) threadedly connected to the shaft belly (51). An oscillating cavity (55) is provided inside the shaft belly (51), and an irregular eccentric spherical object (52) is provided inside the oscillating cavity (55). The lower shaft section (53) is coaxially connected to the crankshaft (12).

2. The additive manufacturing equipment for processing anchor rods according to claim 1, characterized in that: The crankshaft (12) is connected to the frame (10) by a buffer bearing (11).

3. The additive manufacturing equipment for processing anchor rods according to claim 1, characterized in that: The lower part of the shaft (51) is provided with a threaded hole that communicates with the oscillation cavity (55), and a locking nut (56) is sleeved on the outside of the lower shaft section (53), and the locking nut (56) is threadedly connected to the lower shaft section (53).

4. The additive manufacturing equipment for processing anchor rods according to claim 1, characterized in that: The irregular eccentric spherical object (52) is made of lead or lead alloy.

5. The additive manufacturing equipment for processing anchor rods according to claim 3, characterized in that: The oscillation cavity (55) includes a semi-ellipsoidal unit (552) and a semi-spherical unit (551). The semi-ellipsoidal unit (552) is located above the semi-spherical unit (551) and is interconnected. The major axis of the semi-ellipsoidal unit (552) is equal to the diameter of the semi-spherical unit (551).

6. The additive manufacturing equipment for processing anchor rods according to claim 5, characterized in that: The oscillation chamber (55) is filled with lubricating oil.

7. The additive manufacturing equipment for processing anchor rods according to claim 1, characterized in that: The ratio of the volume of the irregular eccentric spherical object (52) to the effective volume of the oscillation cavity (55) is 0.

23.

8. The additive manufacturing equipment for processing anchor rods according to claim 1, characterized in that: The top end of the base rod (30) is provided with a tapered hole, the taper of which is 2.5° to 5°.

9. The additive manufacturing equipment for processing anchor rods according to claim 1, characterized in that: The base (20) has a rotating hole in the center, and the base rod (30) is clearance-fitted with the rotating hole.

10. The additive manufacturing equipment for processing anchor rods according to claim 9, characterized in that: The base (20) is equipped with a vacuum cleaner for vacuuming the rotating hole.

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