CN103241663A - Crane, and telescopic arm and knuckle arm thereof - Google Patents

Abstract

The invention discloses a crane, a telescoping arm of the crane and a joint arm of the crane. In the jib of the disclosed crane, the front wall and the rear wall form a left-right symmetrical structure, which can ensure that the strength in the left and right directions is basically equal and the jib is basically stable. Since the rear wall forms an outwardly convex folding surface structure, and the rear wall forms two bending surfaces. In this way, under the condition of keeping the section perimeter of the joint arm unchanged, the section modulus of the joint arm can be increased, thereby improving the bending, torsional and compressive strength of the joint arm, improving the stability of the joint arm, and reducing the side bending phenomenon. At the same time, the front wall forms four bending surfaces. Compared with the existing structure forming two bending surfaces, this structure can also increase the section modulus of the joint arm, which is conducive to improving the strength and stability of the joint arm and reducing the The side bending phenomenon of the joint arm.

Description

Crane, telescopic arm of crane and articulated arm of crane

technical field

The invention relates to crane technology, in particular to a jib of a crane, and also to a telescopic boom of a crane and a crane including the telescopic boom.

Background technique

A crane generally includes a body and a jib mounted on the body. Currently, the jib of a crane is usually a telescopic jib. The telescopic arm comprises a plurality of joint arms fitted inside and outside. The joint arm is a cylindrical structure, including a front wall, a left wall, a rear arm and a right wall. In order to ensure the sliding fit between the inner and outer adjacent joint arms, a slide block can be arranged between the inner and outer adjacent joint arms. The slide block can be connected with the inner wall surface of the outer joint arm, and is slidably matched with the outer wall surface of the inner joint arm to form a supporting point between two inner and outer joint arms. In order to ensure the force balance of the articulated arm, a plurality of symmetrical sliders are usually arranged.

Please refer to FIG. 1 , which is a schematic diagram of a cross-sectional structure of a known articulated arm; for the convenience of description, in each drawing of this document, arrow B points to the rear, and arrow F points to the front. The joint arm is formed by splicing the rear steel plate 100 and the front steel plate 200; the middle part of the rear steel plate 100 forms the rear wall of the joint arm, and the two sides extend forward; the middle part of the front steel plate 200 forms the front wall of the joint arm, and the two sides face Rear extension; the two sides of the rear steel plate 100 and the two sides of the front steel plate 200 are combined to form a left wall and a right wall, which are connected by welding at W. The front wall of the section arm forms an outwardly convex folding surface structure, including two symmetrical bending surfaces 201, 202 left and right. When the telescopic arm is formed by assembling the section arm, the slider can slide and fit with the two bending surfaces 201 and 202 of the front wall.

Please refer to FIG. 2 , which is a schematic cross-sectional structure diagram of another known joint arm. The front wall of the joint arm front steel plate 200 of this structure basically forms an outwardly convex arc structure. The arc structure can be formed by multiple bending; when the left and right dimensions are small, it is difficult or impossible to disassemble into the arc structure. Therefore, this structure is generally adopted only when the left and right dimensions of the joint arm are relatively large. The joint arm of this structure can ensure the sliding fit of the inner and outer adjacent joint arms, and increase the contact area of the sliding fit.

At present, as shown in Figure 1 and Figure 2, in order to ensure the force on the rear wall of the joint arm, the rear wall is usually set as a plane structure to increase the contact area between the inner and outer adjacent joint arms and reduce stress concentration.

During actual use, the existing articulated boom is prone to side bending and has low stability, which in turn leads to a short service life of the telescopic boom. Although the stability of the joint arm can be increased by using a thicker steel plate to manufacture the joint arm, this leads to an increase in material consumption, which greatly increases the weight of the joint arm, which in turn causes the telescopic arm to be too heavy.

Therefore, how to improve the stability of the joint arm while keeping the material consumption of the joint arm substantially unchanged is a technical problem to be solved by those skilled in the art.

Contents of the invention

In view of this, the present invention provides a jib of a crane, which can improve the stability of the jib while keeping material consumption substantially unchanged.

In addition, a telescopic arm of the crane including the above-mentioned articulated arm and a crane including the telescopic arm are also provided.

The jib of the crane provided includes a front wall, a left wall, a rear wall and a right wall, and the front wall and the rear wall both form a convex, left-right symmetrical folding surface structure; the front wall forms four bending surfaces, The rear wall forms two bending surfaces.

Optionally, the joint arm is surrounded by bending a plate, and the formed joint edges are fixedly connected by welding.

Optionally, the joint edge is located on a left-right symmetrical plane of the joint arm.

Optionally, the joining edge is located in the front wall.

Optionally, the widths of the four bending surfaces of the front wall are equal.

Optionally, in the front wall, the bending surface connected to the left wall is a first bending surface, and the bending surface connected to the first bending surface is a second bending surface; The width of the second bending surface is greater than the width of the first bending surface.

Optionally, the width of the second bending surface is 1.3-1.5 times the width of the first bending surface.

The provided telescopic boom of the crane includes a plurality of inner and outer sleeved jibs, and the jibs are all jibs of any one of the above-mentioned cranes.

Optionally, at least 6 sliders are arranged between the two inner and outer adjacent joint arms; the sliders are all connected to the inner wall surface of the outer joint arm; at least four of the sliders are respectively connected to the inner The four bending surfaces formed by the front wall of the joint arm are slidingly matched; at least two of the sliders are respectively slidingly matched with the two bending surfaces formed by the inner rear wall of the joint arm.

The provided crane includes a main body and a telescopic arm installed on the main body, and the telescopic arm is the telescopic arm of any crane mentioned above.

In the jib of the crane provided by the present invention, the front wall and the rear wall form a left-right symmetrical structure, which can ensure that the strength in the left and right directions is basically equal, and the jib is basically stable. Since the rear wall forms an outwardly convex folding surface structure, and the rear wall forms two bending surfaces. In this way, under the condition of keeping the section perimeter of the joint arm unchanged, the section modulus of the joint arm can be increased, thereby improving the bending, torsional and compressive strength of the joint arm, improving the stability of the joint arm, and reducing the side bending phenomenon. At the same time, the front wall forms four bending surfaces. Compared with the existing structure forming two bending surfaces, this structure can also increase the section modulus of the joint arm, which is conducive to improving the strength and stability of the joint arm and reducing the The side bending phenomenon of the joint arm. In addition, the front wall forms four bending surfaces. When assembling the telescopic arm, at least four sliders can be slidably matched with the four bending surfaces of the front wall, thereby improving the stability and reliability of the sliding fit of the inner and outer section arms. sex.

In a further technical solution, the joint arm is surrounded by a plate material, and the joint edges are fixedly connected by welding. Compared with the joint arm made of multiple plate materials, on the one hand, because there is only one weld seam on the circumferential surface of the joint arm, it is beneficial to ensure the manufacturing quality of the joint arm and improve the reliability of the joint arm; on the other hand, it can The overall strength of the joint arm is greatly improved, which is beneficial to improving the stability of the joint arm and further reducing the side bending phenomenon of the joint arm.

In a further technical solution, the joint edge is located on the left and right symmetrical planes of the joint arm, and is located in the front wall, so that the joint edge is located at a position with less stress, which can better reduce the joint Detrimental effect on arm strength.

In a further technical solution, in the front wall, the bending surface connected to the left wall is a first bending surface, and the bending surface connected to the first bending surface is a second bending surface; The width of the second bending surface is greater than the width of the first bending surface. In this way, the strength in the left and right direction of the front wall can be improved, and the strength in the front and rear direction provided by the left wall and the right wall can be more fully utilized, and then the strength in the left and right direction of the joint arm can be improved on the basis of ensuring the overall strength of the joint arm. It provides a favorable premise to reduce the side bending phenomenon of the articulated arm.

The provided telescopic boom and the crane including the above-mentioned articulated boom also have corresponding technical effects.

Description of drawings

The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

Fig. 1 is a schematic cross-sectional structure diagram of a known joint arm;

Fig. 2 is a schematic cross-sectional structure diagram of another known joint arm;

Fig. 3 is a schematic diagram of the force principle of the telescopic arm of the crane;

Fig. 4 is a schematic cross-sectional structure diagram of a joint arm provided by an embodiment of the present invention;

Fig. 5 is a schematic diagram of the structure of part I-I in Fig. 4 .

In the picture:

Rear steel plate 100, front steel plate 200, bending surface 201, bending surface 202;

The first jib 10, the second jib 20, the third jib 30;

Front wall 310, bending surface 311, bending surface 312, bending surface 313, bending surface 314, left wall 320, rear wall 330, bending surface 331, bending surface 332, right wall 340;

Combining side J, left and right symmetry plane P.

Detailed ways

Based on the technical problems in the background technology, the applicant conducted research on the stress situation of the telescopic boom and the joint boom. Please refer to FIG. 3 , which is a schematic diagram of the force-bearing principle of the telescopic arm; this figure shows the first section arm 10 , the second section arm 20 and the third section arm 30 which are sequentially fitted from outside to inside. Under the action of load G, for the second section arm 20 , its front wall is slidingly fitted with the front wall of the third section arm 30 , and the inner surface of the rear wall is subjected to the external force of the rear wall of the third section arm 30 , at the same time, the outer surface of the rear wall of the second jib 20 is subjected to the internal force of the inner surface of the rear wall of the first jib 10; furthermore, it can be determined that the rear wall of the second jib 20 is subjected to multiple forces, and then the existing The rear wall structure of the joint arm may be the cause of the side bending of the joint arm. The applicant believes that: based on the overall polygonal structure of the articulated arm, the force on the rear wall of the articulated arm is mainly the force on both sides of the rear wall, which may lead to unbalanced forces on both sides of the rear wall, thereby causing side bending of the articulated arm. Based on the above analysis, the present invention proposes a technical solution for improving the articulated arm structure to solve the above technical problems.

Embodiments provided by the present invention are described below. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

Please refer to Figure 4, which is a schematic cross-sectional structure diagram of a joint arm provided by an embodiment of the present invention; in the figure, arrow B points to the rear, arrow F points to the front, arrow L points to the left, and arrow R points to the right square. The jib of the crane is a cylindrical structure, including a front wall 310 , a left wall 320 , a rear wall 330 and a right wall 340 . Wherein, both the front wall 310 and the rear wall 330 are left-right symmetrical structures, which can improve the left-right stability of the joint arm. At the same time, both the front wall 310 and the rear wall 330 form a convex folding surface structure, which can improve the rigidity of the joint arm. Wherein, the front wall 310 forms four bending surfaces 311 , 312 , 313 , 314 . The rear wall 330 forms two bending surfaces 331 , 332 . In practical applications, the jib provided by this embodiment has strong stability while keeping the perimeter of the section constant, and can reduce the side bending phenomenon of the jib.

It has a strong reason for stability. According to the analysis of the applicant, because the rear wall 330 forms a convex folding surface structure, and the rear wall 330 forms two bending surfaces 331 and 332; Under certain circumstances, the section modulus of the joint arm can be increased, and then the bending, torsional and compressive strength of the joint arm can be improved, and the stability of the joint arm can be improved, and the side bending phenomenon of the joint arm can be reduced. In addition, compared with the existing structure that forms two bending surfaces, the front wall 310 forms four bending surfaces 311, 312, 313, 314, which can also increase the section modulus of the joint arm, which is beneficial to improve the joint arm Strength and stability, reducing the side bending phenomenon of the articulated arm.

In one embodiment, when assembling the telescopic arm, the front wall 310 can be used to form four bending surfaces 311, 312, 313, 314; Sliding fit, which can increase the support points of the inner and outer section arms and reduce stress concentration. When comparing the joint arm provided by an embodiment of the present invention with the joint arm shown in Figure 1 (the perimeter of the section and the thickness of the plate material are all equal, and the structures of the front wall 310 and the rear wall 330 are different), the stress at the support point of the front wall 310 It can be reduced by 15%; in addition, due to the formation of multiple support points, the reliability and telescopic stability of the sliding fit between the inner and outer joint arms can be improved.

Compared with the structure shown in Figure 2, in the joint arm provided by this embodiment, its front wall 310 is formed by four bends, and no more bending is required to form a circular arc structure, and this structure can be applied to the left and right sides of the joint arm In the case of a smaller width, the joint arm of this structure has a larger application range. In addition, compared with the circular arc structure, under the condition that the profile of the front wall 310 is basically unchanged and the strength produced by the front wall 310 is basically the same, the perimeter of the section is smaller, which in turn helps to reduce material consumption and reduce the weight of the joint arm. Reducing the weight of the telescopic boom provides a good premise.

Please refer to FIG. 4 , in the embodiment provided by the present invention, the joint arm can be formed by bending a plate (in the embodiment, it is formed by 7 times of bending). The joint edge J formed by bending can be fixedly connected by welding to form a complete cylindrical structure. Compared with the joint arm made of two or more plate materials, on the one hand, there is only one weld on the circumferential surface of the joint arm of this structure, which is beneficial to ensure the manufacturing quality of the joint arm and improve the reliability of the joint arm. On the other hand, the overall strength of the joint arm can be greatly improved, which is conducive to improving the stability of the joint arm and further reducing the side bending phenomenon of the joint arm. Certainly, the articulated arm provided by the embodiment of the present invention may also be assembled from a plurality of board materials.

The position of the joint side J can be determined according to actual needs; for example, the joint side J can be located on the left wall 320 and/or the right wall, or can be located on the left and right symmetrical plane P of the joint arm (shown by a double-dashed line in FIG. 4 ) superior. When the joint edge J is located on the left and right symmetry plane P, it is preferable to make the joint edge J be located in the front wall 310 at the same time, where the stress is pressure, and the welding position has a greater compressive capacity, thereby ensuring the overall strength of the joint arm, and at the same time better Minimize the adverse effect of welding on the strength of the joint arm.

According to the above description, it can be understood that the size of each part of the joint arm can be determined according to actual needs; wherein, the widths of the four bending surfaces 311 , 312 , 313 , 314 of the front wall 310 can be equal or unequal. Please refer to FIG. 5 , which is a schematic structural diagram of part I-I in FIG. 4 . In the front wall 310, the bending surface 311 connected with the left wall 320 is the first bending surface (indicated by 311), and the bending surface 312 connected with the first bending surface 311 is the second bending surface (indicated by 312); in one embodiment, the width W2 of the second bending surface 312 may be greater than the width W1 of the first bending surface 311; in this way, the strength of the left and right directions of the front wall 310 can be improved, and the left wall 320 and the left wall 320 can be more fully utilized. The strength provided by the right wall 340 in the front and rear direction can further improve the strength of the joint arm in the left and right directions on the basis of ensuring the overall strength of the joint arm, and provide a favorable premise for reducing the side bending phenomenon of the joint arm. In an embodiment, the width W2 of the second bending surface 312 may be 1.3˜1.5 times of the width W1 of the first bending surface 311 .

On the basis of providing the above joint arm, an embodiment of the present invention also provides a telescopic arm of a crane, the telescopic wall includes a plurality of joint arms fitted inside and outside, and the joint arm may be any one of the above crane joint arms. Based on the above joint arm, the telescopic arm provided in this embodiment also has corresponding technical effects, which will not be repeated here. Further, at least 6 sliders (not shown in the figure) can be arranged between two adjacent joint arms inside and outside; the sliders can all be connected with the inner wall surface of the outer joint arm; among them, at least four sliders can be Blocks are slidably matched with the four bending surfaces 311, 312, 313, 314 formed by the front wall 310 of the inner joint arm; The flaps 331, 332 are a sliding fit. In this way, more support points can be formed between two adjacent joint arms.

On the basis of providing the above-mentioned telescopic arm, an embodiment of the present invention also provides a crane, the crane includes a body and a telescopic arm installed on the body, and the telescopic arm can be the telescopic arm of any crane mentioned above. Based on the above-mentioned telescopic arm, the crane provided by this embodiment also has corresponding technical effects, which will not be repeated here.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. A jib of a crane, comprising a front wall (310), a left wall (320), a rear wall (330) and a right wall (340), characterized in that the front wall (310) and the rear wall (330 ) all form a convex, left-right symmetrical folding surface structure; the front wall (310) forms four bending surfaces, and the rear wall (330) forms two bending surfaces. 2. The articulated jib of a crane according to claim 1, characterized in that it is formed by bending a plate, and the formed joint edges (J) are fixedly connected by welding. 3. The jib of the crane according to claim 2, characterized in that, the joint edge (J) is located on the left and right symmetry plane (P) of the jib. 4. The articulated jib of a crane according to claim 3, characterized in that the joining edge (J) is located in the front wall (310). 5. The articulated jib of a crane according to any one of claims 1-4, characterized in that the widths of the four bending surfaces of the front wall (310) are equal. 6. The jib of a crane according to any one of claims 1-4, characterized in that, in the front wall (310), the bending surface (311) connected to the left wall (320) is the second A bending surface (311), the bending surface (312) connected to the first bending surface (311) is the second bending surface (312); the width of the second bending surface (312) ( W2) is greater than the width (W1) of the first bending surface (311). 7. The jib of a crane according to claim 6, characterized in that, the width (W2) of the second bending surface (312) is equal to the width (W1) of the first bending surface (311) 1.3 to 1.5 times. 8. A telescoping arm of a crane, comprising a plurality of joint arms fitted inside and outside, characterized in that, all the joint arms are the joint arms of the crane according to any one of claims 1 to 7. 9. The telescopic arm of a crane according to claim 8, wherein at least 6 slide blocks are arranged between two adjacent joint arms inside and outside; connected; at least four of the sliders are slidingly matched with the four bending surfaces formed by the front wall (310) of the inner section arm; at least two of the sliders are respectively connected with the rear of the inner section arm The two bent surfaces formed by the wall (330) are a sliding fit. 10. A crane, comprising a body and a telescopic arm mounted on the body, characterized in that the telescopic arm is the telescopic arm of the crane according to claim 8 or 9.

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