JP4653460B2 - Crane bumper - Google Patents

Description

  The present invention relates to a crane bumping device.

  When constructing a high-rise structure, a climbing crane is used in which the crane body rises with the structure as the work progresses.In such a climbing crane, It is necessary to work with the jib standing upright in an inclined state close to 80 degrees or more.

  Thus, when working with the jib standing upright in an upright position, if the jib is blown by the wind from the front, the jib may be further bounced and collide with the top of the guy support. When the jib is turned down, there is a problem that it is difficult to smoothly turn down the jib by its own weight only by feeding the wire rope with the hoisting winch.

  Therefore, as a means to prevent the jib from jumping due to wind etc. and to give auxiliary force when lowering the jib when working with the jib standing in an almost upright inclined state, Guy support has been conventionally used. The climbing crane which provided the undulation buffering device which has an elastic means at the top of is used.

  An example of a conventional climbing crane having such a undulating shock absorber is shown in FIGS. 5 and 6, in which 1 is a mast standing on the foundation surface or floor surface, and 2 is a crane body. The main body 2 includes an elevating frame 3 that is positioned on the top of the mast 1 and can be fixed to and removed from the mast 1, and a revolving frame 4 that is pivotally installed on the upper surface of the elevating frame 3. Thus, a guy support 5 having a triangular side surface is erected on the revolving frame 4, and the wire rope 7 of the hoisting winch 6 is wound or wound on the upper surface of the rear end portion of the revolving frame 4. A jib 8 that can be raised and lowered by taking it out is pivotally supported.

  A cylinder-type undulation buffer 9 is provided on the top of the guy support 5. Thus, as shown in FIG. 6, the undulation cushioning device 9 is connected to a cylinder body 10 supported at the top of the guy support 5 at the rear end and a piston 11 fitted to the cylinder body 10 so as to be movable back and forth. A fixed piston rod 12, an elastic member 13 that is rotatably supported at the tip of the piston rod 12 and can support a jib 8 that stands upright in an inclined state, and a piston 11 in the cylinder body 10. A spring 14 is provided which is housed on the rear side and urges the piston rod 12 in a direction protruding outward through the piston 11.

  Thus, in the above climbing crane, when the jib 8 stands up in an extremely inclined state close to the upright, the back surface of the jib 8 abuts against the elastic member 13 and pushes the piston 11 through the piston rod 12. For this reason, the spring 14 of the undulation buffer 9 is compressed and the jib 8 is buffered. Further, even if the wind pushes the jib 8 further in the direction of rising, the jib 8 is supported by the undulation buffering device 9, so there is no possibility of coming into contact with the top of the guy support 5.

  When the jib 8 is lowered from a nearly upright state, when the wind is blowing from the front surface to the jib 8, even if the wire rope 7 of the hoisting winch 6 is fed without the spring 14, the jib 8 is not affected by its own weight alone. Is difficult to rotate downward. However, since the spring 14 of the undulation cushioning device 9 presses the jib 8, an auxiliary force is applied to the jib 8, and the jib 8 can be smoothly lowered.

There exists patent document 1 as a jib control apparatus of a climbing crane. In this patent document 1, in a climbing crane for a steel tower in which a jib and an A frame are attached to a crane body, one end of a first support is pivotally connected near the root of the jib so that the top of the A frame or the vicinity thereof The part is composed of a telescopic cylinder that combines an outer cylinder and an inner cylinder, and one end of the second support can be swung freely by interposing a compression spring that is compressed when the telescopic cylinder shortens beyond a certain length on one end. Pin connected, pin connected so that the other end of the first support and the second support can bend each other, and if the jib is raised above a certain angle, the first support will be pressed against the back of the jib and swing further Instead, the force of the compression spring generated by the compression is configured to push out the jib in the vicinity of the upright position.
Japanese Utility Model Publication No. 63-142384

  In the climbing crane shown in FIGS. 5 and 6, the jib 8 does not come into contact with the undulation buffer device 9 unless the jib 8 is fully raised up. For this reason, when the wind blows from the front surface of the jib in a state where the jib 8 is quite upright but not yet supported by the undulation cushioning device 9, as the jib 8 is further raised, the force of lowering by its own weight In an extreme case, the tension acting on the wire rope 7 of the hoisting winch 6 that supports the jib 8 becomes negative, and the jib 8 cannot be lowered. For this reason, when the force is applied in the direction in which the jib 8 is lowered before the jib 8 stands up to the limit, the spring 14 of the shock absorber must have a certain length, and as a result. There is a risk that the undulation cushioning device 9 is increased in size.

  The climbing crane jib restraint device shown in Patent Document 1 includes a first support and a second support, and is refracted according to the undulation of the jib, and the second support has an inner cylinder and an outer cylinder. The expansion / contraction cylinder is provided with a compression spring. For this reason, the apparatus of Patent Document 1 has a complicated structure, and the apparatus becomes large.

  In view of the above-described circumstances, the present invention provides a crane shock absorber for a crane that has a simple structure and can be downsized even when a force is applied in a direction in which the jib is lowered before the jib stands up to its extreme position. It was made for the purpose of doing.

  The crane cushioning device according to the present invention includes a cylinder body, a piston rod capable of moving back and forth in the longitudinal direction of the jib relative to the cylinder body, and a piston rod of the cylinder body. A shock absorber main body provided with an elastic body accommodated on the side, a first sheave is provided on the protruding portion of the piston rod from the cylinder main body, and a position separated from the first sheave in the longitudinal direction of the jib A second sheave supported by a jib is provided, and a string-like body fixed at one end to the jib and fixed at the other end to a frame body pivotally supported by the jib is connected to the first sheave and the second sheave. It is wrapped around a sheave.

  In the crane shock absorber of the present invention, the elastic body is a compression spring. When the jib is not raised up to a predetermined angle, the end of the compression spring opposite to the piston, A gap is formed between the piston rod protruding side end portions, and a plurality of first and second sheaves are provided.

  In the crane shock absorber according to the present invention, when the jib is tilted from a loose tilt angle to an almost upright tilt state, the jib is turned upward to rise. At this time, since the length of the string-like body is constant, one end is fixed to the jib and the other end is fixed to the frame body, the second sheave of the string-like body from the second sheave of the string-like body as the jib rises. The length to the fixing position is increased, and the length to the fixing position with respect to the jib is shortened through the first and second sheaves of the string-like body. As a result, the first sheave moves to the second sheave side, and the piston rod of the shock absorber body projects from the cylinder body.

  In the present invention, even if the piston rod protrudes from the cylinder body, there is a gap between the end of the compression spring opposite to the piston and the piston rod protruding side end of the cylinder body until the jib stands to some extent, The compression spring housed on the rod side of the cylinder body is in a free state. For this reason, the compression spring is not subjected to a compression force, and therefore the jib is not buffered, and the force for lowering the jib forward does not act.

  When the jib stands up to a predetermined angle, there is no gap between the end of the compression spring opposite to the piston and the end of the cylinder body on the piston rod protruding side. For this reason, a compression spring receives a compression force and bends, and a jib is buffered. Further, the piston rod receives a reaction force in the direction of retreating into the cylinder body by the reaction force of the compression spring, and as a result, a force acts on the string-like body in a direction in which the first and second sheaves are separated.

  Therefore, when the wire rope of the hoisting winch is extended to lower the jib from this state, the piston rod moves back into the cylinder body by the reaction force of the compression spring, and the first sheave and the second sheave are separated. Therefore, the length from the second sheave to the fixing position of the string-like body with respect to the frame body is shortened, and as a result, the jib can be smoothly lowered.

According to the crane shock absorbers of the first to fourth aspects of the present invention, various excellent effects can be obtained as described below.
I) By changing the length of the compression spring, the position where the compression spring works can be set arbitrarily, so that the compression spring can be used with the jib standing up to the middle position.
II) Therefore, even when the wind blows from the front of the jib while the jib stands up to the middle, the jib can be smoothly lowered.
III) Since the number of string-like members is multiple, even if the compression spring is applied in a state where the jib is erected up to the middle part, the stroke of the shock absorber body can be reduced, and as a result, The shock absorber main body, and hence the undulating shock absorber, has a simple structure and can be reduced in size.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 4 show an example of an embodiment of the present invention. In the figure, the parts denoted by the same reference numerals as those in FIGS. It is the same as the conventional one shown in FIG.

  Thus, in the illustrated example, the cylinder-type undulation cushioning device 15 of the present invention is disposed on the base end side of the jib 8. That is, the undulating shock absorber 15 is fixed to a cylinder body 17 pivotally supported by a vertical member 16 having a rear end fixed to the base end side of the jib 8 and a piston 18 slidably fitted in the cylinder body 17. A shock absorber main body 15a having a piston rod 19 that can be moved forward and backward in the longitudinal direction of the jib 8 and a compression spring-like spring 20 that is housed on the piston rod side of the cylinder main body 17 is provided.

  In addition to the shock absorber main body 15a, the undulating shock absorber 15 includes a plurality of (two in the illustrated example) first sheaves 22a and 22b pivotally supported by a bracket 21 attached to the tip of the piston rod 19, and a vertical shaft. A plurality of (two in the illustrated example) second sheaves 24a and 24b pivotally supported by a longitudinal member 23 fixed to the jib 8 at a position farther from the base end side of the jib 8 than the member 16, and a wire rope 25 It has.

  Thus, one end of the wire rope 25 is fixed to the vertical member 23 and extends toward the sheave 22a, is wound around the sheave 22a, extends toward the sheave 24a, is wound around the sheave 24a, and is wrapped around the sheave 22b. Extends toward the sheave 22b and extends toward the sheave 24b, extends around the sheave 24b and extends toward the revolving frame 4, and the other end is fixed near the front end of the revolving frame 4. Has been.

  Further, when the jib 8 is at a position lower than a predetermined angle and the piston rod 19 is retracted, as shown in FIG. A gap C is formed between the piston rod protruding side end, and when the jib 8 stands up to a predetermined angle and the piston rod 19 protrudes, the gap C becomes zero as shown in FIG. Thus, the spring 20 is compressed, and the jib 8 is buffered by the spring 20 and a force is applied in the direction of retracting the piston rod 19.

  Note that a gap C may not be provided between the spring 20 and the front end portion of the cylinder body 17, but in this case, in consideration of the case where the piston rod 19 is pushed back by the spring 20, a spring constant of Try to use a lower one.

Next, the operation of the above-described embodiment will be described.
For example, when the jib 8 has a gentle inclination angle as shown in FIG. 1 and stands up to an extreme inclination state as shown in FIG. 3, the hoisting winch 6 is activated to wind the wire rope 7. . For this reason, the jib 8 is turned upward with the base end portion as a fulcrum and stands up. At this time, since the length of the wire rope 25 is constant and one end is fixed to the vertical member 23 of the jib 8 and the other end is fixed to the revolving frame 4, the sheave of the wire rope 25 is increased as the jib 8 stands up. The length from 24b to the fixed position X of the revolving frame 4 is increased, and the length from the sheave 24b of the wire rope 25 to the fixed position Y of the jib 8 with respect to the vertical member 23 through the sheaves 22b, 24a, 22a is decreased. As a result, the sheaves 22a and 22b move to the sheaves 24a and 24b, and the piston rod 19 of the shock absorber main body 15a protrudes from the cylinder main body 17.

  Even if the piston rod 19 protrudes from the cylinder body 17, a gap C is formed between the end of the spring 20 opposite to the piston 18 and the end of the cylinder body 17 on the piston rod protruding side until the jib 8 rises to some extent. The spring 20 housed on the rod side of the cylinder body 17 is in a free state. For this reason, the spring 20 is not subjected to a compressive force, and therefore, the jib 8 is not buffered, and the force for lowering the jib 8 forward does not act.

  However, when the jib 8 stands up to a predetermined angle, the gap C between the end of the spring 20 opposite to the piston 18 and the end of the cylinder body 17 on the piston rod protruding side disappears. For this reason, when the jib 8 further rises, the spring 20 receives the compression force and bends, and the jib 8 is buffered. Also, the piston rod 19 receives a force in the direction of retreating into the cylinder body 17 due to the reaction force of the spring 20, and as a result, the wire rope 25 has a force in a direction in which the sheaves 22 a and 22 b and the sheaves 24 a and 24 b are separated from each other. Works.

  Therefore, when the hoisting winch 6 is activated to lower the jib 8 from this state and the wire rope 7 is fed out, the piston rod 19 is retracted into the cylinder body 17 by the reaction force of the spring 20, and the sheave 22a. 22b and the sheaves 24a and 24b are separated from each other, the length from the sheave 24b to the fixing position X of the wire rope 25 with respect to the revolving frame 4 is shortened. As a result, the jib 8 can be smoothly lowered.

  As shown in FIGS. 1 and 2, the length from the sheave 24b of the wire rope 25 to the fixed position X of the revolving frame 4 when the inclination angle of the jib 8 is loose is L1, and the sheaves 24a and 24b and the sheaves 22a and 22b. The distance from the sheave 24b of the wire rope 25 to the fixed position X of the revolving frame 4 when the jib 8 stands up to the limit as shown in FIG. 3 is L2, and the sheaves 24a and 24b And the sheaves 22a and 22b, the distance between the sheave 24b of the wire rope 25 and the fixed position X of the swivel frame 4 when the jib 8 stands up from the position shown in FIG. The change length L is L = L2−L1, and the number of hooks of the ropes between the sheaves 24a and 24b and the sheaves 22a and 22b is 4, so the cylinder stroke S is S = (L2−L1). / A 4 = S1-S2.

  That is, when L1 = 4,500 mm and L2 = 9,700 mm, the cylinder stroke S = (9,700-4,500) / 4 = 1,300 mm.

  According to the illustrated example, by changing the length of the spring 20, the position where the spring 20 works can be arbitrarily set. That is, in the conventional case shown in FIGS. 5 and 6, the spring 20 would not work unless the jib 8 was raised up to the limit, but in this example shown, the spring 20 was raised up to a midway position. Can be used. Therefore, even when the wind blows from the front surface of the jib 8 at the intermediate position of the jib 8, the jib 8 can be smoothly lowered. Further, even if the spring 20 is activated with the jib 8 raised to a midway position, since the number of the wire rope 25 is multiple, the cylinder stroke S of the shock absorber main body 15a can be reduced. As a result, the shock absorber main body 15a and thus the shock absorber 15 can have a simple structure and can be downsized.

  In the illustrated example of the present invention, the case where the hoisting shock absorber is applied to a climbing crane has been described. However, the present invention can be applied to any crane provided with a jib for hoisting. Of course, various modifications can be made without departing from the scope of the invention.

It is a side view which shows an example of embodiment of the crane with which the undulation buffer apparatus of this invention is applied, and shows a state in which the jib is in an intermediate position below a standing position close to an upright position. It is an enlarged view of the undulation cushioning device when the jib is in the position of FIG. It is a side view which shows an example of embodiment of the crane with which the undulation buffer apparatus of this invention is applied, and shows a state where the jib is in an upright position close to an upright. FIG. 4 is an enlarged view of the undulation buffer when the jib is in the position of FIG. 3. It is a partial side view of the crane provided with the conventional undulation shock absorber. FIG. 6 is an enlarged view of the undulation buffer device of FIG. 5.

Explanation of symbols

4 Revolving frame (frame)
8 Jib 15 Undulating shock absorber 15a Shock absorber main body 17 Cylinder main body 18 Piston 19 Piston rod 20 Spring (elastic body)
22a Sheave (first sheave)
22b Sheave (first sheave)
24a sheave (second sheave)
24b Sheave (second sheave)
25 Wire rope (string)
C gap

Claims (4)

  A jib pivotably supported by a frame includes a cylinder body, a piston rod that can move forward and backward in the longitudinal direction of the jib relative to the cylinder body, and an elastic body that is housed on the piston rod side of the cylinder body. And a second sheave supported by the jib at a position away from the first sheave in the longitudinal direction of the jib. A string-like body having one end fixed to the jib and the other end fixed to a frame body pivotally supported on the jib is wound around the first sheave and the second sheave. Crane hoisting shock absorber.   The crane cushioning device according to claim 1, wherein the elastic body is a compression spring.   The clearance gap is formed between the edge part on the opposite side to the piston of a compression spring, and the piston rod protrusion side edge part of a cylinder main body in the state which the jib does not stand up to the predetermined angle. Crane undulation shock absorber.   4. The crane cushioning shock absorber according to claim 1, wherein a plurality of first and second sheaves are provided.

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