JP4836476B2 - Telescopic boom for self-propelled crane - Google Patents

Description

  The present invention relates to a telescopic boom used for a self-propelled crane such as a crawler crane or a truck crane.

  2. Description of the Related Art Conventionally, telescopic booms used for self-propelled cranes such as crawler cranes and truck cranes are known (see, for example, Patent Document 1).

  In the telescopic boom described in Patent Document 1, the first telescopic cylinder is disposed between the first boom and the second boom, and the second boom is disposed between the second boom and the third boom. The third telescopic cylinder is disposed, and the third telescopic cylinder is disposed between the third boom and the fourth boom. The first telescopic cylinder extends and retracts the second boom relative to the first boom, the second telescopic cylinder extends and retracts the third boom relative to the second boom, and the third telescopic cylinder. Is configured to extend and retract the fourth boom relative to the third boom.

JP 2001-48477 A

  FIG. 5 is a side view of a conventional telescopic boom. In the figure, reference numeral 5 denotes a four-stage telescopic boom, and in the first box boom 5a on the proximal end side, the second box boom 5b, the third box boom 5c, and the fourth box boom 5d on the distal end side in sequence. Is telescopically inserted in a telescopic manner. A first telescopic cylinder 9A is disposed between the first box boom 5a and the second box boom 5b, and a second telescopic cylinder is disposed between the second box boom 5b and the third box boom 5c. A cylinder 9B is disposed, and a third telescopic cylinder 9C is disposed between the third box boom 5c and the fourth box boom 5d. The first telescopic cylinder 9A extends and retracts the second box boom 5b relative to the first box boom 5a, and the second telescopic cylinder 9B moves the third box boom 5c relative to the second box boom 5b. The third telescopic cylinder 9C is adapted to telescopically drive the fourth box boom 5d with respect to the third box boom 5c.

  The tip end 9Aa of the piston rod of the first telescopic cylinder 9A is connected between the side surfaces on the proximal end side of the first box boom, and the end 9Ab on the rod side of the same telescopic cylinder 9A is the second box boom. A leg portion 21a having a flat roller that is in contact with the bottom surface of the box boom is attached to the lower end portion 9Ac of the cylinder in the same telescopic cylinder 9A. Yes. The tip end 9Ba of the piston rod of the second telescopic cylinder 9B is connected between the side surfaces of the base end side of the second box boom 5b, and the end 9Bb on the rod side of the cylinder in the same telescopic cylinder 9B is the third box. A leg portion 21b having a flat roller that contacts the bottom surface of the box boom is attached to the lower end 9Bc of the cylinder of the same telescopic cylinder 9B on the piston side of the cylinder 5B. ing. The tip 9Ca of the piston rod of the third telescopic cylinder 9C is connected between the side surfaces of the fourth box boom 5d, and the piston side end 9Cc of the same telescopic cylinder 9C is the base of the third box boom 5c. It is connected between the side surfaces on the end side.

  The telescopic boom shown in FIG. 5 has the following problems. (1) In the first telescopic cylinder 9A and the second telescopic cylinder 9B, the tip end 9Aa of the piston rod is connected between the side surfaces on the base end side of the first box boom, and the rod side of the cylinder in the same telescopic cylinder 9A The end portion 9Ab is connected between the side surfaces on the proximal end side of the second box boom 5b. The tip end 9Ba of the piston rod of the second telescopic cylinder 9B is connected between the side surfaces of the base end side of the second box boom 5b, and the end 9Bb on the rod side of the cylinder in the same telescopic cylinder 9B is the third box. It is connected between the side surfaces of the base end side of the boom 5c. These two telescopic cylinders are supported at two points as described above, and the end of the telescopic cylinder on the piston side is a free end. Therefore, if the boom is moved, the swinging may occur and the cylinder may be damaged. . Therefore, leg portions having flat rollers that come into contact with the bottom surface of the box boom are provided at the piston-side ends of these two telescopic cylinders. However, since the movement of the leg portion in the left-right direction cannot be restricted, the cylinder may be damaged. (2) The third telescopic cylinder 9C is different from the first telescopic cylinder 9A and the second telescopic cylinder 9B in that the directions of the rod and the cylinder are reversed, and the mounting method and length are also different. It cannot be used and maintenance is inconvenient. (3) It is necessary to perform machining for connecting the tip 9Ca of the piston rod of the third telescopic cylinder 9C to the side surface near the tip of the fourth box boom 5d, and it takes time to set up.

The present invention has been devised in view of the above-described problems of the prior art, and (1) an improved method for supporting the piston-side end of the telescopic cylinder other than the telescopic cylinder for driving the box boom at the final stage. The purpose is to (2) reduce the maintenance cost by sharing all the telescopic cylinders, and (3) reduce the labor for machining the final box boom. .

  To achieve the above object, the telescopic boom of the self-propelled crane of the present invention is pivotally supported on the swing frame of the self-propelled crane so that the base end portion can be raised and lowered, and a plurality of box booms can be slid in a telescopic manner sequentially A telescopic boom of a self-propelled crane that is inserted and expands and contracts by a plurality of telescopic cylinders, wherein the second to nth box booms are telescopically driven by first to n−1th telescopic cylinders, respectively. The 1st to (n-1) th extension cylinders are arranged in parallel sequentially from the bottom to the top, and among the 1st to (n-1) th extension cylinders, the kth The tip of the piston rod of the No. expansion cylinder is connected between the side surfaces of the base end side of the kth box boom, and the end of the cylinder rod side of the same expansion cylinder is the (k + 1) th box boom. Are connected between the base side surfaces of the cylinder, and at the piston side end of the same expansion / contraction cylinder, there is a flat roller in contact with the bottom surface of the box boom at the bottom, and the upper k + 1th A guide roller device having a drum roller that contacts the lower surface of the telescopic cylinder is attached, and the tip of the piston rod of the (n-1) th telescopic cylinder is between the side surfaces on the proximal end side of the (n-1) th box boom. The end of the cylinder in the same telescopic cylinder on the piston side is fixed to the ceiling surface on the tip side of the nth box boom.

The self-propelled crane may be a crawler crane or a truck crane.

  Since the telescopic boom of the self-propelled crane of the present invention is configured as described above, it has the following excellent effects. (1) At the piston-side end of the expansion cylinder other than the expansion boom cylinder for driving the box boom at the final stage, a flat roller that contacts the bottom surface of the box boom is provided at the lower portion, and the lower surface of the upper expansion cylinder is disposed at the upper portion. Since the guide roller device having the drum roller that contacts is attached, the swinging of the end of the expansion / contraction cylinder on the piston side in the vertical and horizontal directions can be restricted to prevent the expansion / contraction cylinder from being damaged. (2) Since all the telescopic cylinders are shared, maintenance costs can be reduced. (3) For all telescopic cylinders, the tip of the piston rod is attached so that the distal end of the telescopic boom faces the proximal end of the telescopic boom. It is not necessary to perform machining for coupling, and the labor for setup can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a four-stage telescopic boom will be described. In the claims, this is generalized and defined as having n stages. FIG. 1 is a side view of the self-propelled crane of the present invention. FIG. 2 is a partially enlarged view of FIG. 1 and a side view of the telescopic boom. In these drawings, reference numeral 1 denotes a crawler type self-propelled crane. 2 is a crawler, 3 is a lower traveling body, and 4 is a turning frame. Reference numeral 5 denotes a box-type telescopic boom. The lower end of the boom 5 is pivotally attached to the revolving frame 4 and can be raised and lowered by a boom hoisting device (hydraulic cylinder) 6. 7 is a boom top, and 8 is a hoisting rope. Reference numeral 9 denotes a telescopic cylinder, and three are used in this example. Reference numeral 10 denotes a guide sheave disposed at the upper end on the back side of the boom top 7. Reference numeral 11 denotes a top sheave disposed on the front side of the boom top 7, and rope sheaves are attached in multiple lines. Reference numeral 12 denotes an auxiliary hook sheave disposed on the front side of the boom top 7, which is provided in front of the top sheave 11. Reference numeral 13 denotes a hook block suspended from the hoisting rope 8, and rope sheaves are attached in multiple lines. Reference numeral 15 denotes a hook attached to the hook block 13. Reference numeral 20 denotes a boom foot pin, which is supported on the upper part of the revolving frame 4 and pivotally supports the boom 5. Reference numeral 24 denotes a rope overwinding prevention device. The rope overwinding prevention device 24 lifts the weight when the weight is suspended from a limit switch (not shown), the hoisting rope 8 is wound up and the hook block 13 is raised to a predetermined position, and the hoisting rope is operated by operating the limit switch. 8 is prevented from overwinding. An auxiliary hook 25 is suspended by an auxiliary rope around which the auxiliary hook sheave 12 is wound. A rope guide 27 guides the hoisting rope 8 provided on the back surface of the boom 5.

  The structure of the telescopic boom will be described in more detail with reference to FIG. 2, FIG. 3, and FIG. 3A is a side view of the guide roller device, and FIG. 3B is a front view of the guide roller device. FIG. 4 is a view showing a method for connecting the first telescopic cylinder 9A and the box boom, and FIG. 4A shows a method for connecting the tip end 9Aa of the piston rod between the side surfaces of the base end side of the first box boom 5a. (B) shows a method of connecting the end 9Ab on the rod side of the cylinder between the side surfaces on the base end side of the second box boom 5b. In addition, the overlapping description is abbreviate | omitted about the part which is common in the part demonstrated using FIG. In these figures, 5 is a four-stage telescopic boom. The second box boom 5b, the third box boom 5c, and the fourth box boom 5d on the distal end side are inserted into the first box boom 5a on the proximal end side in a telescopic manner so as to be telescopically expandable. . These box booms have a substantially parallelogram shape in a side view. A first telescopic cylinder 9A is disposed between the first box boom 5a and the second box boom 5b, and a second telescopic cylinder is disposed between the second box boom 5b and the third box boom 5c. A cylinder 9B is disposed, and a third telescopic cylinder 9C is disposed between the third box boom 5c and the fourth box boom 5d. The first telescopic cylinder 9A extends and retracts the second box boom 5b relative to the first box boom 5a, and the second telescopic cylinder 9B moves the third box boom 5c relative to the second box boom 5b. The third telescopic cylinder 9C is adapted to telescopically drive the fourth box boom 5d with respect to the third box boom 5c.

  The tip end 9Aa of the piston rod of the first telescopic cylinder 9A is connected between the side surfaces on the base end side of the first box boom 5a, and the end 9Ab on the rod side of the cylinder of the same telescopic cylinder 9A is the second box. A guide roller device 22A is attached to an end portion 9Ac on the piston side of the same telescopic cylinder 9A that is connected between side surfaces on the base end side of the boom 5b. To connect the distal end 9Aa of the piston rod of the first telescopic cylinder 9A to the side surface on the proximal end side of the first box boom 5a, as shown in FIG. 4A, the base of the first box boom 5a is connected. The piston rod tip 9Aa is attached to the rod 33 which is passed between the side surfaces on the end side. To connect the end 9Ab on the rod side of the cylinder in the same telescopic cylinder 9A to the side surface on the base end side of the second box boom 5b, as shown in FIG. 4B, the rod side of the cylinder in the telescopic cylinder 9A A rod 34 is attached between the boss 35 attached to the end portion 9Ab and the side face on the proximal end side of the second box boom 5b. The guide roller device 22A attached to the end portion 9Ac on the piston side of the expansion / contraction cylinder 9A has a structure as shown in FIG. As shown in the drawing, a bracket 30 is attached to the end surface of the end portion 9Ac on the piston side of the cylinder toward the front. The bracket 30 is composed of a proximal end side bracket 30a and a distal end side bracket 30b. The distal end side bracket 30b has a bracket 36a for supporting the spindle 36 of the drum roller 31 attached to the upper surface, and a flat roller on the lower surface. A bracket 37a for supporting the 32 support shafts 37 is attached. The drum roller 31 is in contact with the lower surface of the second expansion cylinder 9B, and the flat roller 32 is in contact with the bottom surface of the fourth box boom 5d. The radius of curvature of the drum roller 31 is preferably slightly larger than the radius of curvature of the telescopic cylinder.

  The tip end 9Ba of the piston rod of the second telescopic cylinder 9B is connected between the side surfaces of the base end side of the second box boom 5b, and the end 9Bb on the rod side of the cylinder in the same telescopic cylinder 9B is the third box. A guide roller device 22B is attached to the piston-side end portion 9Bc of the cylinder in the same telescopic cylinder 9B. The method of connecting the telescopic cylinder 9B and the box booms 5b and 5c and the guide roller device 22B are substantially the same as those of the first telescopic cylinder 9A described above, and thus the description thereof is omitted.

The tip end 9Ca of the piston rod of the third expansion cylinder 9C is connected between the side surfaces on the base end side of the third box boom 5c, and the end 9Cb on the rod side of the cylinder in the same expansion cylinder 9C is the fourth box. It is connected between the side surfaces of the base end side of the boom 5d, and the end portion 9Cc on the piston side of the same telescopic cylinder 9C is fixed to the ceiling portion of the fourth box boom 5d via the bracket 23. Note that the cylinder rod-side end 9Cb of the telescopic cylinder 9C does not necessarily have to be connected between the base-side side surfaces of the fourth box boom 5d.

  Next, the operation of the embodiment of the present invention will be described. (1) The end of the expansion cylinder other than the third expansion cylinder 9C on the piston side has a flat roller 32 in contact with the bottom surface of the box boom at the lower part, and contacts the lower surface of the upper expansion cylinder 9 at the upper part. Since the guide roller device 22 having the drum roller 31 is attached, it is possible to restrict the vertical and horizontal swinging of the end of the expansion cylinder 9 on the piston side and prevent the expansion cylinder from being damaged. (2) Since all the telescopic cylinders 9 are shared, maintenance costs can be reduced. (3) Since all of the telescopic cylinders 9 are attached with the distal ends of the piston rods facing the base end side of the telescopic boom 5, the third side is located on the side surface near the distal end of the fourth box boom 5d as in the prior art. It is not necessary to perform machining for connecting the tip end 9Ca of the piston rod of the extension / contraction cylinder 9C, and it is possible to reduce the setup effort.

  The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the gist of the present invention. For example, although the self-propelled crane has been described as a crawler crane in the present embodiment, it may be a truck crane.

It is a side view of the self-propelled crane of the present invention. It is a side view of a telescopic boom. (A) is a side view of a guide roller device, and (B) is a front view of the guide roller device. It is drawing which shows the connection method of a 1st expansion-contraction cylinder and a box boom. It is a side view of the conventional telescopic boom.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Self-propelled crane 4 Revolving frame 5 Telescopic boom 5a 1st box boom 5b 2nd box boom 5c 3rd box boom 5d 4th box boom 9 Telescopic cylinder 9A 1st telescopic cylinder 9B 2nd telescopic cylinder 9C No. 3 telescopic cylinder

Claims (3)

The base end of the self-propelled crane is pivotally supported so that it can be raised and lowered, and a plurality of box booms are inserted slidably in a telescopic manner. Booms Nos. 2 to n are boom-expanded by Nos. 1 to n-1 telescopic cylinders, respectively, and Nos. 1 to n-1 telescopic cylinders are moved downward. The tip of the piston rod of the kth expansion cylinder among the 1st to n-1th expansion cylinders is arranged at the base of the kth box boom. It is connected to an end side surface pointing passed rod between the end portion of the rod side of the cylinder is connected between the side of the base end side of the k + 1 th box boom in the same telescopic cylinder, the same A guide roller having a flat roller that contacts the bottom surface of the box boom at the lower portion and a drum roller that contacts the lower surface of the upper k + 1th telescopic cylinder at the upper portion at the piston end of the cylinder in the compression cylinder The device is attached, and the end of the telescopic cylinder on the piston side is sandwiched between the upper and lower guide rollers to regulate the swinging in the vertical direction and the horizontal direction . The tip of the piston rod of the telescopic cylinder is connected between the side surfaces on the base end side of the (n-1) th box boom, and the piston side end of the same telescopic cylinder is the tip of the nth box boom. is fixed to the ceiling surface side, are fixed boss having a hole on both sides of the rod side of the cylinder in the telescopic cylinder, box A hole is drilled in the base end side of the boom, a rod is inserted between the hole of the boss and the side of the box boom, and the rod side of the telescopic cylinder is supported. A telescopic boom for a self-propelled crane, characterized by having a common telescopic cylinder . The telescopic boom of a self-propelled crane according to claim 1, wherein the self-propelled crane is a crawler crane. The telescopic boom of a self-propelled crane according to claim 1, wherein the self-propelled crane is a truck crane.

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