CN116517998A - Friction damper and tower crane - Google Patents

Abstract

The invention discloses a friction damper and a tower crane, relates to the field of tower cranes, and is used for reducing the probability of overturning of the tower crane. The friction damper comprises a housing, a sleeve, a rod member and a first friction member. The casing includes the first through-hole and the first wall hole that run through self length direction, and first wall hole is arranged along the circumference of casing, and the wall body of casing is run through to first wall hole. The sleeve comprises a first counter bore and a second wall bore; one end of the first counter bore where the opening is located in the first through hole, and the closed end of the first counter bore is located outside the first through hole; the second wall holes are arranged along the circumferential direction of the sleeve, and penetrate through the wall body of the sleeve; the first wall hole and the second wall hole are communicated. One end of the rod piece is inserted into the first counter bore, and the other end of the rod piece is positioned outside the first counter bore. The first friction piece is arranged in the second wall hole; the first friction piece is contacted with the outer wall of the rod piece. The technical scheme can effectively consume the overturning moment caused by the relative motion of the parts to be damped, and reduce the overturning danger.

Description

Friction damper and tower crane

Technical Field

The invention relates to the field of tower cranes, in particular to a friction damper and a tower crane.

Background

The tower crane, which is called tower crane for short, comprises a bottom frame, a tower body and an arm support, and is widely used for building construction, large-scale bridges, wind power construction and nuclear power plants. Typically, the boom of the tower crane is fixed to the top end of the tower body, and the boom includes a crane arm and a balance arm. The lifting hook and the luffing trolley are arranged on the lifting arm and are used for lifting and carrying heavy objects. The balance arm is provided with a balance weight.

In recent years, along with the development trend of the project of the foundation engineering, the development trend of the project of the foundation engineering is more and more towards the large-scale development and the complicated construction environment, so that the tower crane must have the performance or structural requirements of high operation height, heavy weight at the upper part of the tower crane, heavy lifting weight, long amplitude of variable operation and the like. The ultra-large tower crane has high cost and huge size, and when safety accidents occur, the loss of property and the casualties rate are remarkable. Particularly, when the steel wire rope of the crane lifting mechanism is broken or the crane counterweight is in failure and falls off, the lifting moment of the lifting arm is suddenly reduced, or the balancing moment of the balancing arm is suddenly reduced. The super-large tower crane has the characteristics of high operation height, heavy weight at the upper part of the tower crane, heavy lifting load, long amplitude of amplitude-changing operation and the like, and the risk of overturning the tower crane is extremely easy to occur under the unbalanced state of the two sides of the tower body, so that great property loss and safety accidents are caused.

The inventor finds that a technical scheme is needed in the industry at present, and the performance of the tower crane can be improved, and the occurrence probability of accidents is reduced.

Disclosure of Invention

The invention provides a friction damper and a tower crane, which are used for reducing the probability of overturning the tower crane.

An embodiment of the present invention provides a friction damper including:

the shell comprises a first through hole penetrating through the shell in the length direction and a first wall hole, wherein the first wall hole is arranged along the circumferential direction of the shell and penetrates through the wall body of the shell;

a sleeve including a first counterbore and a second wall bore; one end of the first counter bore where the opening is located in the first through hole, and the closed end of the first counter bore is located outside the first through hole; the second wall holes are arranged along the circumferential direction of the sleeve, and penetrate through the wall body of the sleeve; the first wall hole and the second wall hole are communicated;

the rod piece is inserted into the first counter bore at one end, and the other end of the rod piece is positioned at the outer side of the first counter bore; and

a first friction member mounted in the second wall aperture; the first friction piece is contacted with the outer wall of the rod piece.

In some embodiments, the number of the first wall holes is plural, and the plural first wall holes are distributed along the circumferential direction of the housing.

In some embodiments, the number of the second wall holes is plural, and the plural second wall holes are distributed along the circumferential direction of the sleeve.

In some embodiments, the number of the first wall holes and the second wall holes are each a plurality; the plurality of first wall holes correspond to one second wall hole and are communicated.

In some embodiments, the friction damper further comprises:

and the pretightening force applying component is arranged outside the shell so as to apply pretightening force to the first friction piece.

In some embodiments, the pretension-applying member includes:

a pre-tightening bolt mounted to the first wall aperture; and

a disc spring positioned between the pre-tightening bolt and the first friction member;

the magnitude of the pretightening force applied by the disc spring to the first friction piece is adjusted by tightening the pretightening bolt.

In some embodiments, one of the pretensioning bolts and at least one of the disc springs are mounted in each of the first wall holes.

In some embodiments, at least one of the first friction members is mounted in each of the second wall apertures.

In some embodiments, the friction damper further comprises:

the limiting piece is fixed on the inner wall of the first counter bore;

the rod piece is provided with a containing groove, and the limiting piece is located in the containing groove.

In some embodiments, the friction damper further comprises:

the second friction piece is arranged between the limiting piece and the inner wall of the first counter bore.

In some embodiments, along the length of the rod, both ends of the receiving groove are closed to limit the relative displacement of the stopper and the receiving groove.

In some embodiments, a plurality of the first wall holes are respectively arranged along a length direction and a circumferential direction of the housing.

In some embodiments, a plurality of the second wall holes are respectively arranged along a length direction and a circumferential direction of the sleeve.

The embodiment of the invention also provides a tower crane, which comprises:

a tower body;

the arm support is positioned at the top of the tower body; and

according to the friction damper provided by any one of the technical schemes, one end of the sleeve of the friction damper, which is positioned outside the first through hole, is hinged with one of the tower body and the arm support, and the end of the rod piece of the friction damper, which is positioned outside the first counter bore, is hinged with the other one of the tower body and the arm support.

In some embodiments, a plurality of the friction dampers are mounted between the tower body and the boom.

In some embodiments, the area of the area surrounded by the end part of each friction damper connected with the arm support is a, and the area of the area surrounded by the end part of each friction damper connected with the tower body is B, wherein a is smaller than B.

The friction damper provided by the technical scheme forms a friction pair by arranging the friction plate between the rod piece and the sleeve which move relatively. In the use, connect member with one of them part that wait to damp, connect sleeve with another part that wait to damp, as long as these two parts take place relative motion, the friction pair just can play the effect in order to consume the overturning moment that wait to damp the relative motion of part and bring, reduce the risk of overturning. Specifically, the friction damper is arranged between the tower body and the arm support, so that the overturning moment of the tower crane lifted by the arm support is effectively consumed, the tower body bears constant and smaller moment than the overturning moment of the tower crane, the moment balance on two sides of the tower body is realized, and the anti-overturning function of the tower crane in a limit state is finally achieved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:

fig. 1 is a schematic structural diagram of a tower crane according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a boom lifting structure of a tower crane according to an embodiment of the present invention.

Fig. 3 is a schematic perspective view of a friction damper according to an embodiment of the present invention.

Fig. 4 is a schematic front view of a friction damper according to an embodiment of the present invention.

Fig. 5 is a schematic top view of a friction damper according to an embodiment of the present invention.

Fig. 6 is a schematic side view of a friction damper according to an embodiment of the present invention.

Fig. 7 is a schematic cross-sectional structure of a friction damper according to an embodiment of the present invention.

Reference numerals:

1. a housing; 2. a sleeve; 3. a rod piece; 4. a first friction member; 5. a pretightening force applying member; 6. a limiting piece; 7. a tower body; 8. arm support; 9. a second friction member; 10. a friction damper;

11. a first through hole; 12. a first wall aperture;

21. a first counterbore; 22. a second wall aperture;

31. a receiving groove;

51. pre-tightening a bolt; 52. a disc spring;

61. and (5) fastening a screw.

Detailed Description

The technical scheme provided by the invention is described in more detail below with reference to fig. 1 to 7.

The inventor finds that the vibration degree of the tower crane is in direct proportion to the probability of danger, and if the vibration of the tower crane is large, the tower crane is easy to have dangerous accidents; if the vibration of the tower crane is small, the probability of dangerous accidents is greatly reduced. Therefore, the following technical scheme is provided in the embodiment of the invention, so that the energy dissipation and vibration reduction effects on the tower crane, particularly the arm support 8 of the tower crane, are achieved.

Referring to fig. 1 to 3, an embodiment of the present invention provides a friction damper 10 including a housing 1, a sleeve 2, a rod 3, and a first friction member 4. The housing 1 includes a first through hole 11 penetrating in its length direction and a first wall hole 12, the first wall hole 12 being arranged along the circumferential direction of the housing 1, and the first wall hole 12 penetrating through the wall of the housing 1. The sleeve 2 comprises a first counterbore 21 and a second wall bore 22; one end of the first counter bore 21 where the opening is located in the first through hole 11, and the closed end of the first counter bore 21 is located outside the first through hole 11; the second wall holes 22 are arranged along the circumferential direction of the sleeve 2, and the second wall holes 22 penetrate through the wall body of the sleeve 2; the first wall hole 12 and the second wall hole 22 penetrate. One end of the rod 3 is inserted into the first counter bore 21, and the other end of the rod 3 is located outside the first counter bore 21. The first friction member 4 is mounted in the second wall hole 22. The first friction member 4 is in contact with the outer wall of the rod 3 to increase the friction force when the rod 3 slides relative to the sleeve 2.

Referring to fig. 3, the housing 1 is a substantially rectangular housing 1. The housing 1 is provided with a first through hole 11, the first through hole 11 being adapted to pass through the sleeve 2. There is no relative movement between the sleeve 2 and the housing 1, so the fit clearance between the first through hole 11 and the sleeve 2 can be set relatively small; or the gap between the sleeve 2 and the shell 1 is relatively large, and the sleeve 2 and the shell 1 are fixedly connected by fasteners such as bolts.

The housing 1 is provided with a plurality of first wall holes 12, and in particular, a plurality of first wall holes 12 may be provided in a matrix on opposite sides of the housing 1. The first wall aperture 12 is relatively small in size. The first wall holes 12 are arranged in a matrix.

In some embodiments, the number of the first wall holes 12 is plural, and the plural first wall holes 12 are distributed along the circumferential direction of the housing 1. This allows setting and adjustment of the components mounted in the first wall hole 12 from different positions in the circumferential direction of the housing 1.

In other embodiments, a plurality of first wall holes 12 are respectively arranged along the length direction and the circumferential direction of the housing 1. This allows setting and adjustment of the components mounted in the first wall hole 12 from different positions in the circumferential and axial direction of the housing 1. Even if no components are installed in the first wall hole 12, the working state of the first friction member 4 positioned in the second wall hole 22 can be easily observed through the first wall hole 12, so that replacement and overhaul can be timely performed when necessary.

The outer contour shape of the sleeve 2 matches the shape of the first through hole 11 of the housing 1. In some embodiments, the first through hole 11 is a rectangular hole, and the outer contour of the sleeve 2 is also rectangular. Referring to fig. 3-5, or fig. 7, the sleeve 2 includes a first counterbore 21 and a second wall bore 22. The direction of the central axis of the first counterbore 21 is along the length of the sleeve 2. The central axis of the second wall hole 22 intersects the central axis of the first counter bore 21, and may be perpendicular. The first counterbore 21 is used to mount the rod 3. The closed end of the sleeve 2 is then provided with a first hinge hole for enabling the articulation of the friction damper 10 with the component to be damped. The depth of the first counter bore 21 corresponds to the maximum depth of insertion of the rod 3, and if the displacement amount of the part to be damped is large, the depth of the first counter bore 21 is set deeper; if the displacement amount of the member to be damped is small, the depth of the first counterbore 21 is set shallower accordingly.

With continued reference to fig. 7, the second wall aperture 22 is used to mount the first friction member 4. A plurality of first wall holes 12 may be employed to correspondingly communicate with a second wall hole 22. One or more first friction members 4 are provided in each of the second wall holes 22.

In some embodiments, the number of second wall holes 22 is plural, and the plurality of second wall holes 22 are distributed along the circumferential direction of the sleeve 2. The arrangement is such that the friction damper 10 can be provided with a plurality of first friction members 4 at a plurality of different positions to effectively adjust the damping amount of the friction damper 10.

In some embodiments, a plurality of second wall holes 22 are arranged along the length and circumferential direction of the sleeve 2, respectively. This structure allows the first friction member 4 mounted to the second wall hole 22 to be also adjustable and settable from a plurality of directions in the length direction and the circumferential direction of the sleeve 2, so that the performance of the friction damper 10 can be more satisfactory.

With continued reference to fig. 7, in some embodiments, the number of first wall apertures 12 and second wall apertures 22 are each a plurality; the plurality of first wall holes 12 corresponds to and communicates with one of the second wall holes 22. In this way, the second wall hole 22 can be larger in size so as to facilitate the installation of the first friction member 4 with larger size, on one hand, the manufacturing and installation process of the first friction member 4 is simplified, and on the other hand, the friction damper 10 is also provided with a plurality of first friction members 4, so that the damping size of the friction damper 10 can be conveniently adjusted by adjusting the number of the first friction members 4, the size area of the first friction member 4 is larger, and the energy consumption efficiency is higher under the condition of the same stroke.

With continued reference to fig. 7, to facilitate adjusting the magnitude of the friction force of the first friction member 4 in each second wall hole 22, in some embodiments, the friction damper 10 further includes a preload applying member 5, the preload applying member 5 being mounted to the exterior of the housing 1 to apply a preload to the first friction member 4. The first friction piece 4 can be pressed or separated from the outer surface of the rod piece 3 through the pretightening force applying part 5 so as to change the friction force of the rod piece 3 in the moving process relative to the sleeve 2, thereby realizing damping adjustment; the whole axle center compression stability of the friction damper 10 is ensured, and the friction energy consumption efficiency is higher under the same stroke.

The pretensioning force applying member 5 includes a pretensioning bolt 51 and a disc spring 52. The pre-tightening bolt 51 is mounted to the first wall hole 12; the disc spring 52 is located between the pre-tightening bolt 51 and the first friction member 4. The disc spring 52 is pressed by the pretensioning bolt 51 against the side of the first friction element 4 remote from the lever 3. Each of the first friction members 4 may be provided with a plurality of pre-tightening bolts 51. A pre-tightening bolt 51 is mounted in each first wall hole 12. Each pre-tightening bolt 51 corresponds to one disc spring 52. For each first friction member 4, the compression degree of each region thereof can be independently adjusted to the corresponding pre-tightening bolt 51 of that region. The magnitude of the pretensioning force applied to the first friction member 4 by the disc spring 52 is adjusted by tightening the pretensioning bolt 51.

Depending on the desired damping, the first friction member 4 may be mounted in a portion of the second wall openings 22, or at least one first friction member 4 may be mounted in each of the second wall openings 22. The friction between each first friction member 4 and the outer surface of the rod member 3 can be adjusted by the pre-tightening force applying member 5.

Referring to fig. 4 and 7, in some embodiments, the friction damper 10 further includes a stop 6, the stop 6 being secured to the inner wall of the first counterbore 21, particularly by a set screw 61. Wherein, member 3 is provided with accommodation groove 31, and locating part 6 is located in accommodation groove 31. The size of the limiting piece 6 is matched with that of the accommodating groove 31, and the limiting piece and the accommodating groove form surface-to-surface matching. The limiting piece 6 can be in various structural forms such as a bulge and a limiting strip and is used for limiting the relative movement distance of the rod piece 3 and the sleeve 2 so as to prevent the relative movement distance of the rod piece 3 and the sleeve 2 from being too large, so that the part to be damped cannot be damped effectively.

The length L of the accommodating groove 31 is 500mm to 3000mm, for example. The lifting stroke of the arm support 8 of the tower crane is longer. The size range well meets the working requirements of lifting, energy dissipation and vibration reduction of the tower crane arm support 8.

In some embodiments, the friction damper further comprises a second friction member 9, the second friction member 9 being disposed between the stop member 6 and the inner wall of the first counterbore 21. A plurality of second friction members 9 may be provided between the stopper 6 and the inner wall of the first counterbore 21. The second friction member 9 adopts a relatively thin sheet structure, and the second friction member 9 can be fixedly arranged on the limiting member 6.

In some embodiments, along the length of the rod 3, both ends of the receiving groove 31 are closed to limit the relative displacement of the stopper 6 and the receiving groove 31. By providing the accommodation groove 31 of this structure, not only the relative movement distance between the rod 3 and the sleeve 2 is made within a set range, but also the rod 3 and the sleeve 2 are not separated from each other regardless of which direction the rod 3 moves relative to the sleeve 2. By this function of the friction damper 10, the degree of freedom of the member to be damped in the sliding direction of the rod 3 can be restricted, and the stability of the member to be damped can be enhanced while increasing damping vibration.

The principle of operation of the friction damper 10 is as follows: the pull rod, the first friction piece 4 and the sleeve 2 together form a friction pair. The pre-tightening bolt 51 provides positive pressure for the first friction member 4, so that the first friction member 4 is tightly attached to the pull rod and the limiting member 6 is tightly attached to the limiting groove. When the pull rod is displaced, the pull rod simultaneously generates sliding friction with the limiting piece 6 and the first friction piece 4, and the pull force or the pressure is consumed. When the pull rod is displaced to the end of the stroke, the limiting piece 6 limits the displacement of the pull rod, so that the pull rod stops moving.

Referring back to fig. 1 and 2, an embodiment of the present invention provides a tower crane, including a tower body 7, a boom 8, and a friction damper 10 provided by any one of the technical solutions of the present invention. The boom 8 is located at the top of the tower body 7. One end of the sleeve 2 of the friction damper 10, which is positioned outside the first through hole 11, is hinged with one of the tower body 7 and the arm support 8, and the end of the rod 3 of the friction damper 10, which is positioned outside the first counter bore 21, is hinged with the other of the tower body 7 and the arm support 8.

The boom 8 comprises a boom and a counter arm. The lifting hook and the luffing trolley are arranged on the lifting arm and are used for lifting and carrying heavy objects. The balance arm is provided with a balance weight.

The lifting state of the boom 8 is a state in which the boom or the balance arm of the boom 8 rotates bidirectionally in a vertical plane around the double shaft of the tower body 7 when the boom 8 is turned over due to sudden unloading of the boom and failure and falling of the balance weight.

When the arm support 8 is in unbalanced lifting and overturning, the pull rod of the friction damper 10 is pulled out. When the pull rod moves, as the first friction piece 4 is arranged in the second wall hole 22 of the sleeve 2, the rod piece 3 generates friction force relative to the first friction piece 4, and the effects of vibration reduction and energy consumption are achieved, so that the overturning moment of the tower crane with the arm support 8 upwards is consumed, the tower body 7 bears constant and smaller moment than the overturning moment of the tower crane, the moment balance at two sides of the tower body 7 is realized, and the anti-overturning function of the limit state of the tower crane is finally achieved.

When the arm support 8 is reset relative to the tower body 7, the pull rod of the friction damper 10 is pressed and retracted. In the rest state, the friction damper 10 is subjected to a static variable load smaller than the rated damping force.

When the tower crane arm support 8 is not lifted and turned over, the friction damper 10 bears a pulling force smaller than the damping force.

Taking the direction shown in fig. 1 as an example, the friction damper 10 plays a role in vibration reduction and buffering regardless of whether the boom 8 moves upward or downward with respect to the tower body 7.

A specific application scenario is as follows: when the steel wire rope of the lifting mechanism of the tower crane is broken or the balance weight of the tower crane is in failure and falls off, unbalanced moment appears on two sides of the tower body 7, and the unbalanced moment pulls up the arm support 8, so that the arm support 8 is lifted and turned upwards, as shown in fig. 2. When the arm support 8 is lifted and overturned, the pulling force is transmitted to the pull rod of the friction damper 10, the pull rod is pulled, the friction pair forms sliding friction force, and the pulling force and the overturning moment at two sides of the tower body 7 are consumed by acting. In the movement of the tie rod this unbalanced moment will be consumed until the boom 8 stops turning.

According to the pedal crane provided by the technical scheme, the adopted friction damper 10 rises heat by means of friction resistance of the friction pair, so that mechanical energy of the system is reduced, the structure is exquisite and slender, the external dimension is small, and the pedal crane is well suitable for the installation environment between the tower body 7 and the arm support 8. The damping force referred to herein is a force opposite to the direction of the moving speed of the friction damper 10, which is generated by the friction pair.

In some embodiments, in the X direction shown in fig. 1, that is, in the up-down direction in fig. 1, the degrees of freedom of the tower body 7 and the arm support 8 in the X direction are limited by the friction damper 10, specifically, by the limiting member 6 of the friction damper 10, so as to prevent dangerous situations such as excessive displacement of the arm support 8 relative to the tower body 7 in the X direction, and deflection and detachment of the arm support 8; on the other hand, the tower body 7 and the arm support 8 do not need excessive constraint in the X direction, so that the structural redundancy of the tower crane is reduced.

Due to the very large constructional dimensions of the tower crane, in some embodiments a plurality of friction dampers 10 are mounted between the tower 7 and the boom 8. Each friction damper 10 is disposed obliquely in the X-direction, and each friction damper 10 works independently of each other without being affected by each other.

In some embodiments, the area of the area surrounded by the end of each friction damper 10 connected to the boom 8 is a, and the area of the area surrounded by the end of each friction damper 10 connected to the tower 7 is B, where a is smaller than B. By adopting the arrangement mode, the friction damper 10 can connect the arm support 8 and the tower body 7 more firmly and reliably.

In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify 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 thus should not be construed as limiting the protection of the present invention.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be replaced with others, which may not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (16)

1. A friction damper, comprising:

the shell (1) comprises a first through hole (11) and a first wall hole (12) which penetrate through the shell in the length direction, wherein the first wall hole (12) is arranged along the circumferential direction of the shell (1), and the first wall hole (12) penetrates through the wall body of the shell (1);

a sleeve (2) comprising a first counterbore (21) and a second wall bore (22); one end of the first counter bore (21) where the opening is located in the first through hole (11), and the closed end of the first counter bore (21) is located outside the first through hole (11); the second wall holes (22) are arranged along the circumferential direction of the sleeve (2), and the second wall holes (22) penetrate through the wall body of the sleeve (2); -said first wall hole (12) and said second wall hole (22) are through;

the rod piece (3) is inserted into the first counter bore (21) at one end of the rod piece (3), and the other end of the rod piece (3) is positioned outside the first counter bore (21); and

a first friction member (4) mounted in the second wall hole (22); the first friction piece (4) is contacted with the outer wall of the rod piece (3).

2. A friction damper according to claim 1, wherein the number of the first wall holes (12) is plural, and the plural first wall holes (12) are arranged dispersedly along the circumferential direction of the housing (1).

3. A friction damper according to claim 1, characterized in that the number of the second wall holes (22) is plural, and the plural second wall holes (22) are distributed along the circumferential direction of the sleeve (2).

4. The friction damper according to claim 1, wherein the number of the first wall holes (12) and the second wall holes (22) are plural; a plurality of the first wall holes (12) correspond to one of the second wall holes (22) and are communicated.

5. The friction damper according to claim 1, further comprising:

and a pre-tightening force applying component (5) which is arranged outside the shell (1) so as to apply pre-tightening force to the first friction piece (4).

6. A friction damper according to claim 5, wherein the pre-tightening force applying member (5) comprises:

a pre-tightening bolt (51) mounted to the first wall hole (12); and

a disc spring (52) located between the pre-tightening bolt (51) and the first friction member (4);

wherein the magnitude of the pre-tightening force exerted by the disc spring (52) on the first friction member (4) is adjusted by tightening the pre-tightening bolt (51).

7. A friction damper according to claim 6, characterized in that one of said pretensioning bolts (51) and at least one of said disc springs (52) are mounted in each of said first wall holes (12).

8. A friction damper according to claim 6, characterized in that at least one of the first friction members (4) is mounted in each of the second wall holes (22).

9. The friction damper according to claim 1, further comprising:

the limiting piece (6) is fixed on the inner wall of the first counter bore (21);

the rod piece (3) is provided with a containing groove (31), and the limiting piece (6) is located in the containing groove (31).

10. The friction damper according to claim 9, further comprising:

the second friction piece (9) is arranged between the limiting piece (6) and the inner wall of the first counter bore (21).

11. Friction damper according to claim 9, characterized in that along the length of the rod (3) both ends of the receiving groove (31) are closed to limit the relative displacement of the stopper (6) and the receiving groove (31).

12. A friction damper according to claim 1, wherein a plurality of the first wall holes (12) are arranged along the length direction and the circumferential direction of the housing (1), respectively.

13. A friction damper according to claim 1, wherein a plurality of said second wall holes (22) are arranged along the length direction and the circumferential direction of said sleeve (2), respectively.

14. A tower crane, comprising:

a tower body (7);

the arm support (8) is positioned at the top of the tower body (7); and

the friction damper (10) according to any one of claims 1 to 13, wherein one end of the sleeve (2) of the friction damper (10) located outside the first through hole (11) is hinged to one of the tower body (7) and the arm support (8), and the end of the rod (3) of the friction damper (10) located outside the first counter bore (21) is hinged to the other one of the tower body (7) and the arm support (8).

15. Tower crane according to claim 14, characterized in that a plurality of friction dampers (10) are mounted between the tower (7) and the boom (8).

16. Tower crane according to claim 14, wherein the area of the area enclosed by the end of each friction damper (10) connected to the boom (8) is a, and the area of the area enclosed by the end of each friction damper (10) connected to the tower (7) is B, a being smaller than B.