A cylinder anti-lifting device, a lifting arm and a construction machine

Abstract

The utility model relates to hoisting equipment technical field discloses a kind of oil cylinder anti-lifting device, hoist arm and engineering machinery, the oil cylinder anti-lifting device among them includes: mounting seat, for with the cylinder barrel connection of hoist arm first stage oil cylinder;Sleeve ring, the sleeve ring is connected with the mounting seat, limit cavity is equipped on the sleeve ring, the limit cavity is used for hoist arm second stage oil cylinder cylinder barrel to pass through;Sliding structure, it is set on the sleeve ring, for with hoist arm second stage oil cylinder cylinder barrel contact.The sleeve ring of the utility model can pass through hoist arm second stage oil cylinder cylinder barrel, mounting seat can be fixed in first stage oil cylinder cylinder barrel, when first stage oil cylinder cylinder barrel generates lifting torque under the tension of steel wire rope, mounting seat will exert counter torque to first stage oil cylinder cylinder barrel under the gravity of second stage oil cylinder cylinder barrel, to limit first stage oil cylinder cylinder barrel lifting, avoid hoist arm telescopic jam or produce abnormal sound due to first stage oil cylinder cylinder barrel lifting.

Description

Technical Field

[0001] This utility model relates to the field of lifting equipment technology, specifically to a hydraulic cylinder anti-lifting device, a lifting arm, and engineering machinery. Background Technology

[0002] Truck-mounted cranes, as highly efficient equipment integrating lifting and transportation functions, primarily rely on their telescopic booms for lifting capacity. Multi-stage booms achieve flexible changes in boom length through hydraulic cylinders to adapt to different working radius and height requirements. Crane boom systems employing sequential and combined telescopic extension typically require multiple telescopic cylinders. For example, a telescopic boom cylinder and boom disclosed in the prior art include: multiple boom sections telescopically fitted sequentially from the outside in, one or more of which are provided with telescopic device mounting holes. Each boom section fitted outside the boom section with the telescopic device mounting holes is correspondingly provided with telescopic device through holes. When all boom sections are in the fully retracted state, the corresponding telescopic device mounting holes and telescopic device through holes are aligned.

[0003] The aforementioned existing technology represents a relatively common multi-stage crane boom structure. In this type of boom structure, the piston rod end of the first-stage cylinder is hinged to the first boom section, while the cylinder barrel end is connected to the second boom section to drive its second-stage extension and retraction. The piston rod end of the second-stage cylinder is typically hinged to the cylinder barrel of the first-stage cylinder, and the piston rod end is connected to the third boom section to drive its third-stage extension and retraction.

[0004] However, under the complex operating conditions of heavy-load crane operations, during the boom retraction process, the steel wire rope applies an upward torque to the primary hydraulic cylinder, causing the cylinder barrel to rise. This can cause uneven wear of the internal seals of the cylinder, accelerating damage. Furthermore, the small internal space of the boom segment can lead to collisions between the cylinder barrel and the inner wall of the boom segment, resulting in abnormal extension and retraction. Utility Model Content

[0005] In view of the problem that the cylinder barrel of the first-stage hydraulic cylinder is prone to lifting and causing abnormal extension and retraction in the prior art, this utility model provides a hydraulic cylinder anti-lifting device, a lifting arm and engineering machinery, which can prevent the first-stage hydraulic cylinder from lifting when subjected to lifting torque.

[0006] Firstly, this utility model provides a hydraulic cylinder anti-lifting device, comprising: a mounting base for connecting to the end of the cylinder barrel of the first-stage hydraulic cylinder of the lifting boom; a collar connected to the mounting base, the collar having a limiting cavity for the cylinder barrel of the second-stage hydraulic cylinder of the lifting boom to pass through; and a sliding structure disposed on the collar for contacting the cylinder barrel of the second-stage hydraulic cylinder of the lifting boom. The limiting cavity may be formed by the collar itself or by the collar and the mounting base together.

[0007] When using the above-mentioned device, if the collar is a non-removable structure, first slip the collar over the cylinder of the secondary cylinder, allowing the cylinder of the secondary cylinder to pass through the limiting cavity and contact the sliding structure. Then, connect the mounting base to the end of the cylinder of the primary cylinder, forming a connection between the end of the primary cylinder and the cylinder of the secondary cylinder. If the collar is a detachable structure, first connect the mounting base to the end of the cylinder of the primary cylinder, then slip the collar over the outside of the cylinder of the secondary cylinder. When the end of the cylinder of the primary cylinder generates an upward torque under the tension of the wire rope, the mounting base will apply a counter-torque to the cylinder of the primary cylinder under the gravity of the cylinder of the secondary cylinder, thereby limiting the upward movement of the cylinder of the primary cylinder. It is understood that the sliding structure can avoid relative friction between the cylinder of the secondary cylinder and the collar, thus preventing jamming and abnormal noise.

[0008] Preferably, the sliding structure includes a roller rotatably connected to the collar, the roller's rolling contact surface being used to contact the cylinder of the secondary hydraulic cylinder of the boom. During the extension and retraction of the boom, the cylinder of the secondary hydraulic cylinder moves along its own axis, and the roller can rotate along the surface of the cylinder. The roller can rotate indefinitely, resulting in a smaller volume and simpler structure compared to a linear sliding structure.

[0009] Preferably, the rolling contact surface of the roller is provided with an arc-shaped annular groove. The cylinder barrel of the secondary hydraulic cylinder is generally cylindrical, and the arc-shaped annular groove can fit closely to the outer surface of the cylindrical cylinder barrel, avoiding indentations or deformation caused by excessive pressure on the roller or cylinder barrel surface. Moreover, the arc-shaped annular groove can limit the radial displacement of the cylinder barrel of the secondary hydraulic cylinder, ensuring that the mounting base and collar remain stable when subjected to vibration or lateral force.

[0010] Preferably, the collar includes: a first side rod, one end of which is detachably connected to the mounting base; a second side rod, one end of which is detachably connected to the mounting base; and a bottom support rod, both ends of which are detachably connected to the other ends of the first side rod and the second side rod, respectively; the first side rod, the bottom support rod, the second side rod, and the mounting base together form the limiting cavity. Designing the collar as a detachably connected unit of four parts—the first side rod, the second side rod, the bottom support rod, and the mounting base—facilitates the installation and removal of the collar.

[0011] Preferably, the two ends of the roller are detachably and rotatably connected to the first side rod and the second side rod, respectively. The roller is located at the bottom center of the collar, which allows for more even force distribution on the cylinder of the secondary hydraulic cylinder.

[0012] Preferably, the mounting base includes: a top plate; a first reinforcing rib extending along the length of the top plate and connected to the bottom of the top plate; a second reinforcing rib extending along the width of the top plate and connected to the bottom of the top plate; an abutting plate connected to the side of the first reinforcing rib away from the top plate, the abutting plate being used to abut against the pulley support at the end of the secondary cylinder of the lifting boom; a first side rod and a second side rod located on opposite sides of the first reinforcing rib, and both the first side rod and the second side rod being connected to the second reinforcing rib. This mounting base has high rigidity and strength, maintains high stability under complex working conditions, and its connection to the cylinder barrel of the secondary cylinder is an abutment connection, that is, the abutting plate is pressed against the top surface of the pulley support at the end of the secondary cylinder. This connection method is simpler and more convenient and quicker to assemble and disassemble than a fixed connection method.

[0013] Preferably, the top plate has a first downward bending portion and a second downward bending portion at each end. The first downward bending portion and the second downward bending portion can further improve the bending stiffness and structural stability of the mounting base.

[0014] Preferably, the first reinforcing rib has an extension on the side away from the top plate, and the abutting plate and the extension are located on opposite sides of the second reinforcing rib. The extension abuts against one side of the pulley support at the cylinder end of the secondary cylinder, which helps improve the stability of the mounting base.

[0015] Secondly, this utility model also provides a lifting boom, comprising: five boom sections, the five boom sections being slidably connected in sequence; two hydraulic cylinders, the two hydraulic cylinders being arranged in sequence, the piston rod end of the first-stage hydraulic cylinder being rotatably connected to the first-stage boom section, one end of the cylinder barrel of the first-stage hydraulic cylinder being rotatably connected to the second-stage boom section and simultaneously rotatably connected to the piston rod end of the second-stage hydraulic cylinder; one end of the cylinder barrel of the second-stage hydraulic cylinder being rotatably connected to the third-stage boom section; and the cylinder barrel of the first-stage hydraulic cylinder having a portion away from its connection to the second-stage boom section, and the cylinder barrel of the second-stage hydraulic cylinder having a portion near its connection to the third-stage boom section. The crane arm is equipped with pulley supports, pulleys on both sides of the pulley supports and on the fifth-stage boom (4); a wire rope, one end of which is connected to the third-stage boom, and the other end first passes around the pulleys on the first-stage cylinder and the second-stage cylinder from one side, then around the pulleys on the fifth-stage boom, then around the pulleys on the second-stage cylinder and the first-stage cylinder from the other side, and finally connects to the third-stage boom; the aforementioned cylinder anti-lifting device, the mounting base is connected to the cylinder barrel of the first-stage cylinder, and the cylinder barrel of the second-stage cylinder passes through the limiting cavity and abuts against the sliding structure. Except for the cylinder anti-lifting device, the rest of the crane arm's components are existing technologies, therefore the working process and principle of the crane arm will not be described in detail.

[0016] Preferably, a gap is provided between the outer peripheral surface of the cylinder barrel of the secondary cylinder and the inner wall of the limiting cavity, which can avoid friction and wear caused by interference between the inner wall of the limiting cavity and the outer surface of the cylinder barrel of the secondary cylinder.

[0017] Thirdly, this utility model also provides an engineering machinery equipped with the aforementioned lifting boom. The specific types of the engineering machinery include, but are not limited to: crawler cranes, truck cranes, all-terrain cranes, tire cranes, tower cranes, truck-mounted cranes, forklifts, concrete pump trucks, rescue cranes, and any other engineering vehicles or equipment requiring a multi-section lifting boom.

[0018] The beneficial effects of this utility model are as follows: the collar can pass through the cylinder of the secondary hydraulic cylinder of the lifting boom, and the mounting base can be fixed to the cylinder of the primary hydraulic cylinder. When the cylinder of the primary hydraulic cylinder generates an upward torque under the tension of the wire rope, the mounting base can apply a counter torque to the cylinder of the primary hydraulic cylinder, thereby limiting the upward movement of the cylinder of the primary hydraulic cylinder and avoiding the lifting boom from becoming stuck or producing abnormal noise due to the upward movement of the cylinder of the primary hydraulic cylinder. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a hydraulic cylinder anti-lifting device according to an embodiment of the present utility model; Figure 2 This is a schematic diagram of the internal structure of a lifting arm according to an embodiment of the present utility model; Figure 3 for Figure 2 A magnified view of part A in the diagram; Figure 4 This is a schematic diagram of the lifting boom's first-stage hydraulic cylinder in an embodiment of the present invention, showing the lifting state. Figure 5 This is a schematic diagram of the external structure of a lifting arm according to an embodiment of the present utility model.

[0021] Explanation of reference numerals in the attached figures: 1. Mounting base; 101. Top plate; 1011. First downward bend; 1012. Second downward bend; 102. First reinforcing rib; 1021. Extension; 103. Second reinforcing rib; 104. Abutting plate; 2. Collar; 201. Limiting cavity; 202. First side rod; 203. Second side rod; 204. Bottom support rod; 3. Roller; 301. Arc-shaped annular groove; 4. Segment arm; 5. Wire rope; 6. Hydraulic cylinder; 7. Pulley support. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0024] According to an embodiment of the present invention, in a first aspect, a hydraulic cylinder anti-lifting device is provided, such as... Figure 1As shown, it includes: a mounting base 1 for connecting to the end of the cylinder of the first-stage hydraulic cylinder of the boom; a collar 2 connected to the mounting base 1, the collar 2 having a limiting cavity 201; and a sliding structure disposed on the collar 2 for allowing the cylinder of the first-stage hydraulic cylinder of the boom to move relative to the cylinder of the second-stage hydraulic cylinder of the boom. The limiting cavity 201 can be formed by the collar 2 itself, or it can be formed by the collar 2 and the mounting base 1. In this embodiment, the limiting cavity 201 is formed by the collar 2 and the mounting base 1, and the limiting cavity 201 is used for the cylinder of the second-stage hydraulic cylinder of the boom to pass through.

[0025] Combination Figures 1 to 3 As shown, in use, the above-mentioned device first connects the mounting base 1 to the end of the primary cylinder, connecting the end of the primary cylinder to the cylinder of the secondary cylinder. Then, the collar 2 is placed over the cylinder of the secondary cylinder of the lifting boom, allowing the cylinder of the secondary cylinder to pass through the limiting cavity 201 and contact the sliding structure. When the end of the primary cylinder generates an upward torque under the tension of the wire rope 5, the mounting base 1 applies a counter-torque to the cylinder of the primary cylinder under the gravity of the secondary cylinder, thereby limiting the upward movement of the primary cylinder. It is understood that the sliding structure avoids relative friction between the cylinder of the secondary cylinder and the collar 2, thus preventing jamming and abnormal noise.

[0026] Furthermore, the sliding structure includes a roller 3, which is rotatably connected to the collar 2. The rolling contact surface of the roller 3 is used to contact the cylinder of the secondary hydraulic cylinder of the boom. During the extension and retraction of the boom, the cylinder of the secondary hydraulic cylinder moves along its own axis, and the roller 3 can rotate along the surface of the cylinder. The roller 3 can rotate indefinitely, and its size is smaller and its structure is simpler compared to a linear sliding structure.

[0027] Furthermore, an arc-shaped annular groove 301 is provided on the rolling contact surface of the roller 3. The cylinder barrel of the secondary hydraulic cylinder is generally cylindrical, and the arc-shaped annular groove 301 can fit against the outer surface of the cylindrical cylinder barrel, avoiding indentations or deformation caused by excessive pressure on the roller 3 or the cylinder barrel surface. Moreover, the arc-shaped annular groove 301 can limit the radial displacement of the cylinder barrel of the secondary hydraulic cylinder, ensuring that the mounting base 1 and the collar 2 remain stable when subjected to vibration or lateral force.

[0028] Furthermore, the collar 2 includes: a first side rod 202, one end of which is detachably connected to the mounting base 1; a second side rod 203, one end of which is detachably connected to the mounting base 1; and a bottom support rod 204, both ends of which are detachably connected to the other ends of the first side rod 202 and the second side rod 203, respectively. The first side rod 202, the bottom support rod 204, the second side rod 203, and the mounting base 1 together form a limiting cavity 201. Designing the collar 2 as being detachably connected from four parts—the first side rod 202, the second side rod 203, the bottom support rod 204, and the mounting base 1—facilitates the installation and removal of the collar 2.

[0029] Furthermore, the two ends of the roller 3 are detachably and rotatably connected to the first side rod 202 and the second side rod 203, respectively. The roller 3 is located at the bottom center of the collar 2, which makes the force on the cylinder of the secondary cylinder more even.

[0030] Further, the mounting base 1 includes: a top plate 101; a first reinforcing rib 102, which extends along the length of the top plate 101 and is connected to the bottom of the top plate 101; a second reinforcing rib 103, which extends along the width of the top plate 101 and is connected to the bottom of the top plate 101; an abutting plate 104, which is connected to the side of the first reinforcing rib 102 away from the top plate 101, and is used to abut against the pulley support 7 at the secondary end of the lifting arm; a first side rod 202 and a second side rod 203 are respectively located on opposite sides of the first reinforcing rib 102, and both the first side rod 202 and the second side rod 203 are connected to the second reinforcing rib 103. Such mounting base 1 has high rigidity and strength, and still has high stability under complex working conditions. Moreover, its connection with the cylinder barrel of the secondary cylinder is by abutment, that is, by using the abutment plate 104 to press against the top surface of the pulley support 7 at the end of the secondary cylinder. This connection method is simpler than the fixed connection method, and is more convenient and quick to assemble and disassemble.

[0031] Furthermore, the top plate 101 is provided with a first downward bending portion 1011 and a second downward bending portion 1012 at both ends. The first downward bending portion 1011 and the second downward bending portion 1012 can further improve the bending stiffness and structural stability of the mounting base 1.

[0032] Furthermore, the first reinforcing rib 102 has an extension 1021 on the side away from the top plate 101, and the abutting plate 104 and the extension 1021 are located on opposite sides of the second reinforcing rib 103. The extension 1021 can abut against one side of the pulley support 7 at the cylinder end of the secondary cylinder, which helps to improve the stability of the mounting base 1.

[0033] According to an embodiment of the present invention, in a second aspect, a lifting boom is provided, combined with... Figures 1 to 5As shown, it includes: 5 articulated arms 4, which are slidably connected in sequence; 2 hydraulic cylinders 6, which are arranged in sequence, with the piston rod end of the first-stage hydraulic cylinder 6 rotatably connected to the first-stage articulated arm 4, and one end of the cylinder barrel of the first-stage hydraulic cylinder 6 rotatably connected to the second-stage articulated arm 4 and simultaneously rotatably connected to the piston rod end of the second-stage hydraulic cylinder 6; one end of the cylinder barrel of the second-stage hydraulic cylinder 6 is rotatably connected to the third-stage articulated arm 4; pulley supports are provided at the end of the cylinder barrel of the first-stage hydraulic cylinder 6 away from its connection with the second-stage articulated arm 4 and at the end of the cylinder barrel of the second-stage hydraulic cylinder 6 near its connection with the third-stage articulated arm 4. 7. Pulleys are provided on both sides of the pulley support 7 and on the fifth-stage arm 4; wire rope 5, one end of the wire rope 5 is connected to the third-stage arm 4, and the other end first passes around the pulleys on the first-stage cylinder 6 and the second-stage cylinder 6 in sequence from one side, then passes around the pulleys on the fifth-stage arm 4, then passes around the pulleys on the second-stage cylinder 6 and the first-stage cylinder 6 in sequence from the other side, and finally connects to the third-stage arm 4; in the aforementioned embodiment of the cylinder anti-lifting device, the mounting base 1 is connected to the cylinder barrel of the first-stage cylinder 6, and the cylinder barrel of the second-stage cylinder 6 passes through the limiting cavity 201 and abuts against the roller 3. Figure 4 As shown, without the hydraulic cylinder anti-lift device installed, the cylinder barrel of the first-stage hydraulic cylinder 6 will generate an upward torque under the tension of the wire rope 5. Therefore, the lifting boom of this embodiment also includes the aforementioned hydraulic cylinder anti-lift device, specifically as follows: Figures 1 to 3 As shown, the mounting base 1 is connected to the cylinder barrel of the primary hydraulic cylinder 6, and the cylinder barrel of the secondary hydraulic cylinder 6 passes through the limiting cavity 201. Except for the hydraulic cylinder anti-lift device, the rest of the components of the lifting boom are existing technologies, so the working process and principle of the lifting boom will not be described in detail.

[0034] Furthermore, a gap is provided between the outer peripheral surface of the cylinder barrel of the secondary cylinder 6 and the inner wall of the limiting cavity 201 to avoid friction and wear caused by interference between the inner wall of the limiting cavity 201 and the outer surface of the cylinder barrel of the secondary cylinder 6.

[0035] According to an embodiment of the present invention, in a third aspect, a piece of engineering machinery is provided, which is equipped with the aforementioned lifting boom. The specific types of the engineering machinery include, but are not limited to: crawler cranes, truck cranes, all-terrain cranes, tire cranes, tower cranes, truck-mounted cranes, forklifts, concrete pump trucks, rescue cranes, and any other engineering vehicles or equipment that require a multi-section lifting boom.

[0036] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A hydraulic cylinder anti-lifting device, characterized in that, include: Mounting bracket (1) is used to connect to the end of the cylinder of the first stage hydraulic cylinder of the boom; A collar (2) is connected to the mounting base (1). The collar (2) is provided with a limiting cavity (201) for the cylinder of the secondary hydraulic cylinder of the boom to pass through. A sliding structure is provided on the collar (2) for contacting the cylinder of the secondary hydraulic cylinder of the boom.

2. The hydraulic cylinder anti-lifting device according to claim 1, characterized in that, The sliding structure includes a roller (3), which is rotatably connected to the collar (2), and the rolling contact surface of the roller (3) is used to contact the cylinder of the secondary hydraulic cylinder of the boom.

3. The hydraulic cylinder anti-lifting device according to claim 2, characterized in that, The roller (3) has an arc-shaped annular groove (301) on its rolling contact surface.

4. The hydraulic cylinder anti-lifting device according to claim 2, characterized in that, The collar (2) includes: A first side rod (202), one end of which is detachably connected to the mounting base (1); The second side rod (203) has one end detachably connected to the mounting base (1); The bottom support rod (204) has two ends that are detachably connected to the other ends of the first side rod (202) and the second side rod (203), respectively. The first side rod (202), the bottom support rod (204), the second side rod (203), and the mounting base (1) together form the limiting cavity (201).

5. The hydraulic cylinder anti-lifting device according to claim 4, characterized in that, The two ends of the roller (3) are detachably and rotatably connected to the first side rod (202) and the second side rod (203), respectively.

6. The hydraulic cylinder anti-lifting device according to claim 4, characterized in that, The mounting base (1) includes: Top plate (101); The first reinforcing rib (102) extends along the length of the top plate (101) and is connected to the bottom of the top plate (101); The second reinforcing rib (103) extends along the width direction of the top plate (101) and is connected to the bottom of the top plate (101); Abutting plate (104) is connected to the side of the first reinforcing rib (102) away from the top plate (101), and the abutting plate (104) is used to abut against the pulley support (7) at the end of the secondary cylinder of the crane arm. The first side rod (202) and the second side rod (203) are located on opposite sides of the first reinforcing rib (102), and both the first side rod (202) and the second side rod (203) are connected to the second reinforcing rib (103).

7. The hydraulic cylinder anti-lifting device according to claim 6, characterized in that, The top plate (101) has a first downward bending portion (1011) and a second downward bending portion (1012) at both ends.

8. A hydraulic cylinder anti-lifting device according to claim 6, characterized in that, The first reinforcing rib (102) has an extension (1021) on the side away from the top plate (101), and the abutting plate (104) and the extension (1021) are respectively located on opposite sides of the second reinforcing rib (103).

9. A crane boom, characterized in that, include: Five segmented arms (4) are slidably connected in sequence; Two hydraulic cylinders (6) are arranged sequentially. The piston rod end of the first-stage hydraulic cylinder (6) is rotatably connected to the first-stage segment arm (4). One end of the cylinder barrel of the first-stage hydraulic cylinder (6) is rotatably connected to the second-stage segment arm (4) and simultaneously rotatably connected to the piston rod end of the second-stage hydraulic cylinder (6). One end of the cylinder barrel of the second-stage hydraulic cylinder (6) is rotatably connected to the third-stage segment arm (4). The cylinder barrel of the first-stage hydraulic cylinder (6) is provided with pulley supports (7) at the end away from its connection with the second-stage segment arm (4), and the cylinder barrel of the second-stage hydraulic cylinder (6) is provided with the end close to its connection with the third-stage segment arm (4). Pulleys are provided on the opposite sides of the pulley supports (7) and on the fifth-stage segment arm (4). A steel wire rope (5) is connected at one end to the third-stage boom (4), and at the other end, it first passes around the pulley on the first-stage cylinder (6) and the pulley on the second-stage cylinder (6) in sequence from one side, then passes around the pulley on the fifth-stage boom (4), then passes around the pulley on the second-stage cylinder (6) and the pulley on the first-stage cylinder (6) in sequence from the other side, and finally connects to the third-stage boom (4). In the hydraulic cylinder anti-lift device as described in any one of claims 1 to 8, the mounting base (1) is connected to the cylinder barrel of the first-stage hydraulic cylinder (6), and the cylinder barrel of the second-stage hydraulic cylinder (6) passes through the limiting cavity (201) and abuts against the sliding structure.

10. An engineering machinery, characterized in that, It is equipped with the lifting arm as described in claim 9.

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