JP2007191250A - Jib expansion device of mobile crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a jib expansion device of a mobile crane capable of solving a problem causing a factor of degrading the hoisting performance that a first tension rod 6 of a known jib expansion device has a complicated structure on the whole, and its weight is large. <P>SOLUTION: A first tension rod (45) consists of two rods pivotably attached to right and left upper mounting parts (46) at a fore end of a boom. A second tension rod (47) consists of two rods connected to right and left jib fore ends. A guide member (64) having a pair of right and left guide faces (65) facing the direction of the right and left side faces of the boom which are tapered forward of the boom is arranged on a front part of the boom fore end. When a jib (43) is shifted from the expansion position to the hoisting position associated with the operation of a tilt cylinder (58), a lower end of the first tension rod is guided by the guide member (64) so as to be expanded in the right-to-left direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a jib overhanging device that is used by overhanging the tip of a boom of a mobile crane.

  In general, in a mobile crane equipped with a boom, a jib can be detachably attached to the tip of the boom. In this case, various types of jib overhanging methods have been proposed. As one of them, the base end portion is pivotally connected to the jib connecting portion at the lower end of the boom, and the lower end of the boom is folded from the lower holding position to the front of the boom. There has been known a downward swinging method that can be extended by swinging to a protruding position.

  The jib swinging forward of the boom is kept in an extended state by a tension rod that is extended between the tip of the jib and the mounting portion at the upper end of the boom. In this case, a tilt cylinder is provided. The tilt angle of the jib with respect to the boom can be adjusted by increasing or decreasing the effective length of the tension rod as the tilt cylinder expands and contracts.

  Such a downward swinging type jib overhanging device is generally one that uses the rope tension of the sub-hook wire rope, but such a rope tension using method cannot be applied to a heavy jib. Since there is a problem that the connecting work of connecting the end of the tension rod to the mounting part at the upper end of the boom after the jib swinging out (relatively high place from the ground) is required, the output of the tilt cylinder is reduced. There has been proposed a method for using the jib to be used (see Patent Document 1). FIG. 6 shows a main part of the jib overhanging device described in Patent Document 1.

  As shown in FIG. 6, the jib overhanging device described in Patent Document 1 includes a first tension rod 6 whose upper end is pivotally attached to a mounting portion 26 at the top end of the boom 1, and the first tension rod 6. The second tension rod 5 is connected to one end of the lower end 9b and the connecting pin 28. The other end of the second tension rod 5 is connected to the tip of the jib 2 so as to be movable along the longitudinal direction of the jib, and moves with respect to the jib by a tilt cylinder disposed at the tip of the jib 2. Yes. The base end portion 2a of the jib 2 is rotatably connected to the jib connecting portion 10 at the lower end of the boom 1 tip. Reference numeral 33 denotes a rotation restricting member for the first tension rod 6, which restricts and restricts the rotation of the lower end portion 9 b of the first tension rod 6 in a direction approaching the jib connecting portion 10. The position of the lower end portion 9b at the time is set to be in front of the boom rather than the jib connecting portion 10.

In the jib overhanging device having the above-described configuration, the boom 1 is lifted at a predetermined undulation angle and the jib 2 is suspended from the jib connecting portion 10 and the jib 2 is extended from the tip of the boom 1 to the end of the boom 1. The posture can be changed in accordance with the expansion / contraction operation of the tilt cylinder. According to the method of swinging out the jib using the output of the tilt cylinder, it can be applied to a heavy jib, and there is an effect that it is not necessary to connect the tension rod at a high place after swinging out the jib. ing.
Japanese Patent Laid-Open No. 5-116888 (pages 4-8, 8 and 10)

  However, the jib overhanging device described in the example of Patent Document 1 has the configuration of the first tension rod 6 as shown in FIG. That is, the first tension rod 6 is divided into the first divided rod 8 and the second divided rod 9 and connected by the connecting pin 27. The first split rod 8 is a unitary structure in which a pair of rods pivoted to the left and right mounting portions 26 at the top of the telescopic boom tip are connected by a connecting member 35. In addition, since the hook suspended from the tip of the boom 1 must be passed between the pair of left and right tension rods in the swinging process of the jib 2, the second split rod 9 spreads in the left-right direction more than the first split rod 8. It is structured to be connected to the left and right end portions of the connecting member 35 so as to be in the right position. Thus, since the 1st tension rod 6 was a complicated structure, the weight became large as a whole, and became a factor which lowered the lifting performance.

  On the other hand, in order to connect the second tension rod 5 to the first tension rod 6 at the lower holding position where the jib 2 is folded along the lower surface of the boom 1 as shown in FIG. The main body portion 11 and the extension portion 12 are configured, and the extension portion 12 is extended from the tension rod main body portion 11 with the boom 1 lying down, and then connected to the first tension rod 6. Specifically, one end 17 of the extension portion 12 is rotatably connected to the end portion 18 of the tension rod main body portion 11, and the other end portion of the extension portion 12 is folded to the tension rod main body portion 11 with a pin 19 when not in use. In use, the pin 19 is pulled out and the extension portion 12 is rotated to extend (the halfway process is indicated by a broken line 12 '). ). However, in such a structure, when the second tension rod 5 is connected to the first tension rod 6, the extension 12 is accidentally rotated and dropped, and the other end of the extension 12 may collide with an operator. There was sex.

  Accordingly, the present invention aims to reduce the weight of the first tension rod by a simple structure and to solve the above-mentioned problem by adopting a structure that does not cause the extension portion of the second tension rod to rotate and drop. It intends to provide a jib overhanging device for a crane.

  A jib extension device for a mobile crane according to claim 1 of the present application is configured such that a base end portion is rotatably connected to a jib connection portion at a lower end of a boom that can be raised and lowered, and is folded along a lower surface of the boom. A jib that can be extended by swinging from a lower holding position to a protruding position in front of the boom through a hanging position below the boom tip, and an upper end of the jib that is pivotally attached to the mounting portion at the top of the boom tip. A first tension rod whose lower end position is regulated by a rotation regulating member and whose lower end position is in front of the boom relative to the jib coupling portion; A second tension rod in which a lower end portion of the first tension rod and one end thereof are removably connected to each other and the other end is connected to the tip of the jib so as to be movable along the longitudinal direction of the jib; A tilt cylinder that is disposed at an end and moves the other end of the second tension rod relative to the jib, and the jib extends and retracts between a suspended position and an extended position in a boom raising position. A jib overhanging device for a mobile crane that is configured to be able to change its posture along with the above.

  The jib overhanging device has two rods pivotally attached to the left and right mounting portions of the boom tip upper part and the second tension rod connected to the jib tip left and right, respectively. A guide member having a pair of left and right guide surfaces facing the left and right sides of the boom that taper toward the front of the boom is disposed at the front end of the boom, and the jib is moved along with the operation of the tilt cylinder. The first guide rod is guided by the guide member so that the lower end of the first tension rod expands to the left and right when moving from the extended position to the suspended position.

  Furthermore, in the jib overhanging device for the mobile crane described in claim 2 of the present application, the second tension rod is composed of a tension rod main body portion and an extension portion, and the extension portion extends from the tension rod main body portion to the tension rod shaft. The structure is characterized in that it can be expanded and contracted in the direction, and the rotation of the extension portion in the direction away from the jib is restricted when the extension portion is extended from the tension rod main body portion.

  The jib overhanging device for a mobile crane described in claim 1 has a very simple structure because the first tension rod is composed of two independent rods. It is very lightweight compared to the tension rod. Therefore, the lifting performance is not lowered as in the case of a mobile crane provided with a conventional jib overhanging device. Furthermore, a guide member having a guide surface facing the left and right side surfaces of the pair of left and right booms is arranged at the front end of the boom, and the jib moves from the extended position to the suspended position in accordance with the operation of the tilt cylinder. Since the lower end of the first tension rod is guided by the guide member so as to expand to the left and right, the hook suspended from the tip of the boom in the process of extending and retracting the jib is similar to the conventional jib extending device. It is possible to pass smoothly between a pair of tension rods that expand to the left and right.

  In the jib extension device for a mobile crane according to claim 2, the second tension rod is composed of a tension rod main body portion and an extension portion, and the extension portion can be extended and contracted in the tension rod axial direction from the tension rod main body portion. In addition, when the extension portion is extended from the tension rod body, the extension portion end portion is configured to be restricted from rotating in the direction away from the jib, so that when the second tension rod is connected to the first tension rod, There is no risk of accidentally rotating and dropping the extension.

  FIG. 1 shows an upper portion A of a mobile crane equipped with a jib overhanging apparatus according to an embodiment of the present invention. A boom 40 that can be raised and lowered is pivotally attached to the swivel base 39, and a jib coupling portion 42 is provided at a lower portion of the tip 41 of the boom 40. Reference numeral 43 denotes a jib in a holding position folded along the lower surface of the boom 40. Similar to the jib 2 described in Patent Document 1, the jib 43 is pivotally connected to the jib connecting portion 42 so that the base end portion 44 is pivoted to the front of the boom through the hanging position below the boom tip. It is a jib that uses a lower swinging method that can be extended by swinging it to a position.

  Reference numeral 45 denotes a first tension rod pivotally attached to a mounting portion 46 at the upper part of the boom tip 41. Reference numeral 47 denotes a second tension rod, and one end 48 of the second tension rod can be connected to and released from the lower end 49 of the first tension rod 45 so as to be rotatable. The other end 50 of the second tension rod 47 is connected to the jib tip 53 so as to be movable along the longitudinal direction of the jib 43. Specifically, a pin 57 is fitted so as to be movable along a long hole 55 of a support 54 fixed to the jib tip 53, and the other end 50 of the second tension rod 47 is integrated with the pin 57. It is configured as. A tilt cylinder 58 is disposed at the jib tip 53 and moves the other end 50 of the second tension rod 47 with respect to the jib 43. The cylinder side end of the tilt cylinder 58 is pivotally attached to a support 59 fixed to the jib, and the rod side end is connected to the pin 57.

  Reference numeral 60 denotes a jib storage device disposed on the boom 40. The jib storage device grips the jib 43 at the lower-holding position and pulls up the jib 43 to the storage position on the side of the boom. In this embodiment, an example of a jib overhanging device having a function of storing the jib 43 on the side surface of the boom will be described. However, it is not a requirement of the present invention that the jib 43 is stored on the side surface of the boom 40. The jib overhanging device of the present invention can be applied as long as the jib 43 takes the holding position.

  FIG. 2 is a detailed view around the tip of the boom 40 of the mobile crane shown in FIG. FIG. 3 is a view taken in the direction of arrow A in FIG. 2, and shows the front end of the boom 40 as viewed from the front. Hereinafter, an embodiment of a jib overhanging device according to the present invention will be described with reference to FIGS.

  As shown in FIG. 3, the jib connecting portion 42 at the lower end of the boom tip is composed of a pair of round bars protruding left and right from the boom tip 41. The base end portion 44 of the jib 43 is bifurcated so as to be able to engage with the pair of left and right jib connecting portions 42, and the base end portion 44 is engaged with a round bar constituting the jib connecting portion 42. It has the connection piece 61 provided with the shape which can be combined. FIG. 2 shows a state where the connecting piece 61 on the jib side is engaged with the connecting portion 42 on the boom side. Further, a jib connecting pin 62 having a handle is passed through the through hole at the tip of the connecting piece 61. In this state, the jib 43 can be hung downward with respect to the jib connecting portion 42.

  As shown in FIG. 3, the first tension rod 45 includes two rods 45 </ b> L and 45 </ b> R that are pivotally attached to a mounting portion 46 at the top of the boom tip 41 by a pin 63. Thus, since it was set as the independent simple-shaped rod, the 1st tension rod 45 can be made very lightweight compared with what was described in patent document 1. FIG.

  Reference numeral 64 denotes a guide member that has a pair of left and right guide surfaces 65 facing the left and right sides of the boom that taper toward the front of the boom, and is disposed at the front of the boom tip 41. In the present embodiment, the guide member is composed of a pair of left and right independent cross-sectional members 64L and 64R. A guide roller 66 is provided at the lower end portion 49 of the first tension rod so as to be rotatable toward the guide surface 65 of the guide member. The guide roller 66 rotates on the guide surface 65 when the first tension rod rotates around the pin 63 of the mounting portion 46. By this action, when the jib 43 moves from the extended position in front of the boom 40 to the suspended position, the lower end portion 49 of the tension rod is expanded left and right. Accordingly, the connecting portion of the second tension rod 47 with the first tension rod 45 is also expanded left and right. For this reason, similarly to the conventional jib overhanging device, the hook suspended from the tip of the boom during the jib overhanging and retracting process can be smoothly passed between the pair of tension rods.

  Reference numeral 67 denotes a rotation restricting member disposed in front of the boom tip portion 41, which is equal to or more than a predetermined amount in the direction of approaching the jib connecting portion 42 of the first tension rod lower end portion 49 as in the conventional jib overhanging device. The position of the first tension rod lower end portion 49 when the rotation is restricted is positioned in front of the boom with respect to the jib connecting portion 42. Reference numeral 68 denotes a first tension rod storage member disposed in a pair of left and right at the front lower portion of the boom tip portion 41 for fixing the first tension rod 45 to the boom tip portion 41 when not in use. It is a member.

  Reference numeral 47 shown in FIG. 2 denotes a second tension rod composed of two rods connected to the left and right of the jib tip 53. The second tension rod 47 includes a tension rod main body 71 and an extension 70. FIG. 2 shows a state in which the extension portion 70 is extended from the tension rod main body portion 71 and the extension side end portion is connected to the first tension rod lower end portion 49 and the tension rod connecting pin 72.

  FIG. 4 is a detailed view of the end of the second tension rod 47 on the side to be connected to the first tension rod 45. (A) The figure shows the state where the extension part 70 is contracted with respect to the tension rod body part 71, and (b) the figure shows the state where the extension part 70 is extended with respect to the tension rod body part 71. Yes. The extension portion 70 is configured integrally with a boss member 74 having a hole 73 into which the tension rod connecting pin 72 is inserted and a telescopic member 76 made of a plate material having a long hole 75. On the other hand, a pair of receiving members 77 are arranged at the end of the tension rod main body 71 at intervals that allow the telescopic member 76 to enter. The receiving member 77 is configured in a straight line with a long pipe material 78 constituting the second tension rod 47. Above and below the receiving member 77, an upper side connecting member 79 that connects the upper sides of the pair of receiving members 77 is arranged, and lower side connecting members 80 and 81 that connect the lower sides are arranged. The distance between the upper side connecting member 79 and the lower side connecting members 80 and 81 is slightly larger than the vertical dimension of the expandable member 76. Reference numeral 81 denotes a guide pin that is disposed through the pair of receiving members 77 and the elongated hole 75 of the elastic member 76 at the same time.

  Since the end of the second tension rod 47 on the side connected to the first tension rod 45 has the above-described configuration, the extension portion 70 has a length in the longitudinal direction of the elongated hole 75 relative to the tension rod main body portion 71. The two-tension rod 47 can be expanded and contracted in the longitudinal direction. Further, when the extension portion 70 shown in FIG. 4B extends from the tension rod main body portion 71, the overlapping portion of the elastic member 76 overlaps with the receiving member 77 by the upper side connecting member 79 and the lower side connecting member 80. Since it is sandwiched in the direction, the extension member 70 is restricted from rotating around the guide pin 81. That is, during the operation of connecting the boss member 74 of the extension portion 70 shown in FIG. 2 to the first tension rod lower end portion 49, the rotation of the extension portion 70 in the direction away from the jib 43 is restricted. Therefore, there is no risk of accidentally rotating and dropping the extension portion 70 when the second tension rod 47 is connected to the first tension rod 45.

  In addition, 82 is an expansion / contraction restriction pin disposed through the pair of receiving members 77, and the expansion / contraction material of the extension member 70 is provided when the expansion / contraction restriction pin 82 is disposed in the state of FIG. The reduction of 76 to the receiving member 77 side is regulated. In order to store the extension member 70 in the tension rod main body 71 in the state of FIG. 4A, the extension restriction pin 82 is once pulled out to reduce the extension member 70, and the extension restriction pin 82 is inserted into the storage hole A again. What should I do?

  FIG. 5 shows a state in which the jib base end portion 44 is connected to the jib connecting portion 42 of the boom tip portion 41 and the jib 43 is in a suspended position below the boom tip portion. The first tension rod lower end portion 49 is in contact with the rotation restricting member 67 of the boom tip portion 41, and the extension portion 70 of the second tension rod 47 is connected to the lower end portion 49 of the first tension rod 45. At this time, the first tension rod lower end portion 49 is expanded to the left and right by the action of the guide member 64 disposed at the boom tip portion 41, and accordingly, the second tension rod 47 is also connected to the bifurcated jib base end portion 44. It spreads to the left and right so that it is almost the same distance. Thereby, the main hook 83 suspended from the boom tip 41 can pass between the pair of left and right second tension rods 47.

  In the retracting process in which the jib 43 is pulled toward the boom 40 from the state shown in FIG. An offset operation for moving to a shifted position is performed simultaneously. For this reason, the second tension rod 47 on the offset side moves slightly upward. At this time, a contraction operation occurs in which the elastic member 76 of the extension portion 70 of the second tension rod moved upward enters the receiving member 77.

  However, this reduction operation may not be performed smoothly, and the entire extension 70 may be lifted and lifted to the first tension rod 45 via the tension rod connecting pin 72 in some cases. In this case, the first tension rod 45 is disengaged from the rotation restricting member 67 and comes closer to the jib connecting portion 42 than the original restricting position, so that the jib overhanging / retracting operation cannot be performed. There is.

  Reference numeral 84 denotes an extension portion regulating member attached to the elastic member 76 of the extension portion 70. When the extension part 70 tries to lift up unexpectedly, the extension part restricting member 84 comes into contact with the lower part of the rotation restricting member 67 of the boom tip part 41 to restrict the lifting of the entire extension part 70. It has become.

  Reference numeral 85 denotes a plate provided on the first tension rod lower portion 49, and reference numeral 86 denotes a guide support provided on the rotation restricting member 67. The guide support 86 is positioned on the left and right sides of the boom tip 41 with respect to the plate 85. Even if the first tension rod 45 is likely to be disengaged from the rotation restricting member 67, the plate 85 having a length longer than the lifting height restricted by the extension restricting member 84 is guided by the guide support 86. Therefore, the first tension rod 45 is prevented from approaching the jib coupling portion 42 from the original restriction position.

It is the upper part A of the mobile crane equipped with the jib overhanging device concerning the invention of this application. It is detail drawing of the boom 40 front-end | tip part periphery of the mobile crane which concerns on invention of this application. FIG. 3 is a view as viewed from an arrow A in FIG. 2, and shows a front end portion of a boom 40. 5 is a detailed view of one end of the second tension rod 47 on the side connected to the first tension rod 45. FIG. This shows a state where the jib 43 is in the hanging position below the boom tip. This is the main part of the jib overhanging device described in Patent Document 1. It is the 1st tension rod of the jib overhanging device indicated in patent documents 1. The conventional 2nd tension rod is shown.

Explanation of symbols

40: Boom 41: Boom tip 42: Jib connecting portion 43: Jib 44: Jib base end portion 45: First tension rod 46: Mounting portion 47: Second tension rod 48: Second tension rod one end portion 49: First tension Rod lower end 50: second tension rod other end 53: jib tip 58: tilt cylinder 64: guide member 65: guide surface 67: rotation restricting member 70: extension 71: tension rod main body

Claims (2)

The base end portion of the boom (40) that can be raised and lowered is pivotally connected to the jib connection portion (42) at the lower end of the boom (40). And a jib (43) that can be extended by swinging out to a protruding position in front of the boom, and an upper end of the jib (43) that is pivotally attached to the mounting portion (46) at the upper end of the boom. The first tension rod whose lower end position is regulated by the pivot regulating member (67) and whose lower end position is more forward than the jib connecting part (42) when the pivoting restricting member (67) regulates the pivoting in the direction approaching (45) and a second tension rod in which the lower end portion of the first tension rod and one end thereof are releasably connected to each other and the other end is connected to the tip of the jib so as to be movable along the longitudinal direction of the jib. ( 7) and a tilt cylinder (58) that is disposed at the tip of the jib and moves the other end of the second tension rod with respect to the jib (43). The jib (43) is suspended in a boom upright posture. In the jib extension device of the mobile crane configured to be able to change the posture between the position and the extension position in accordance with the expansion and contraction operation of the tilt cylinder (58),
The first tension rod (45) is two rods pivotally attached to the left and right mounting portions (46) at the top of the boom tip, and the second tension rod (47) is connected to the left and right of the jib tip. In addition to a rod, a guide member (64) having a pair of left and right guide surfaces (65) facing the left and right sides of the boom tapering toward the front of the boom is disposed at the front end of the boom, and the tilt cylinder (58 ) Is guided by the guide member (64) so that the lower end of the first tension rod expands to the left and right when the jib (43) moves from the extended position to the suspended position. Jib overhanging device for mobile crane. In the jib extension device of the mobile crane according to claim 1,
The second tension rod (47) includes a tension rod body portion (71) and an extension portion (70), and the extension portion (70) can be expanded and contracted in the tension rod axial direction from the tension rod body portion (71). In addition, the movement is characterized in that the extension portion (70) is configured to be restricted from rotating in the direction away from the jib (43) when the extension portion (70) is extended from the tension rod body portion (71). Type crane overhanging device.

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