JP4323854B2 - Safety device for crane with jib - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety device for a crane with a jib in which a base end portion of a jib is pivotally attached to a distal end portion of a telescopic boom, and the jib can be raised and lowered by a winch through a mast provided at the distal end portion of the telescopic boom. It is.
[0002]
[Prior art]
1 to 7 show such a known jib crane. (Patent Document 1) This known jib crane has a carriage 1, a turntable 11 mounted on the carriage 1 so as to be horizontally turnable, and can be raised and lowered in a vertical plane on the turntable 11. The telescopic boom 2 mounted as described above, the jib 3 mounted so that it can be raised and lowered at the tip 2b of the telescopic boom 2, and the jib support device 4 that supports the jib 3 at the telescopic boom tip 2b at an arbitrary hoisting angle. The basic configuration. The cart 1 is provided with an outrigger device 12 so that the cart 1 can be supported and fixed by the outrigger device 12 during crane operation.
[0003]
In this embodiment, the telescopic boom 2 is a multi-stage telescopic type (for example, a 5-stage telescopic type). A support 22 having a predetermined length (for example, about 4 to 5 m) is attached to the tip of the tip boom. In this embodiment, the tip of the support 22 becomes the telescopic boom tip 2b.
[0004]
The telescopic boom 2 is raised and lowered by a hoisting cylinder (hydraulic cylinder) 21 within a range between a substantially horizontal posture and a substantially vertical posture. The telescopic boom 2 is telescopically operated (not shown) by an expansion / contraction cylinder built in the telescopic boom.
[0005]
The jib 3 is configured by sequentially connecting a plurality of divided jibs 31 in a row. The jib 3 is mounted so that the base end portion 3a is pivotally supported by the shaft 29 on the distal end portion (the distal end portion of the support 22) 2b of the telescopic boom 2 so that the base can be raised and lowered within the hoisting surface of the telescopic boom 2. .
[0006]
The jib support device 4 includes two front and rear masts 42, 41 each having a base end portion 42a, 41a pivotally attached to the boom tip end portion 2b, and a distance maintaining unit for maintaining a distance between the front mast 42 and the rear mast 41. A member 43, a tension member (wire rope) 48 for connecting the tip 42b of the front mast 42 and a proper position of the jib 3, a winch 44 for raising and lowering the jib mounted on the swivel base 11, and extending from the winch 44 The mast pulling rope 45 is provided.
[0007]
The front mast 42 and the rear mast 41 are each composed of a rod-like body having a considerable length (for example, about 7 to 8 m, respectively) in order to increase the angle formed between the tension member 48 and the jib 3. Further, each of the masts 42 and 41 has two rod-like bodies on the left and right. During crane operation, a large buckling pressure is applied to each of the masts 41, 42. However, each of the masts 41, 42 needs to have a strength that can sufficiently withstand the buckling pressure. The weight of each is considerably large. In this embodiment, two rods on the left and right are used for the front and rear masts 42 and 41, respectively, but in the other embodiments, one front mast 42 and one rear mast 41 are provided. It can also be.
[0008]
The front mast 42 and the rear mast 41 are connected to the telescopic boom tip 2b as follows. That is, the base end portion 41a of the rear mast 41 is integrally fixed with the vicinity of the upper rear corner of the triangular connecting plate 49 with a small area, and the lower corner of the connecting plate 49 can be expanded and contracted. A pivot 56 is pivotally attached to the upper end position of the boom distal end portion 2 b, and a proximal end portion 42 a of the front mast 42 is pivotally attached to the upper front corner of the connecting plate 49 by a shaft 57. Therefore, the front mast 42 and the rear mast 41 can individually swing within the jib undulation surface on the back side of the boom 2 or jib 3. Further, as shown in FIG. 4, both the masts 41 and 42 can be laid down to the retracted position close to the back surface of the telescopic boom 2 with each base end portion pivotally attached to the telescopic boom distal end portion 2 b. It has become. In the state where the masts 41 and 42 are stored on the telescopic boom 2 side, the rear mast 41 is on the lower side (inner side) and the front mast 42 is on the upper side (outer side).
[0009]
Between the front mast 42 and the rear mast 41, an interval holding member 43 (a pair of left and right) is provided that holds an interval between the masts. Here, as the interval holding member 43, a member in which two front and rear link pieces 43a and 43b are connected by a shaft 43c so as to be bent is used. The interval holding member 43 is permanently installed with its end portions pivotally connected to the front end portion 42b of the front mast 42 and the front end portion 41b of the rear mast 41 by shafts 52a and 51a. Therefore, as shown in FIG. 2, the front mast 42 and the rear mast 41 are opened to the maximum with the distance holding member 43 extending in a straight line, and on the other hand, as shown in FIG. Is bent, the front mast 42 and the rear mast 41 come close to each other. In the state where both the masts 41 and 42 are fully opened (the state in which the interval holding member 43 is tensioned), the angle between the both masts is set to, for example, about 60 °. Here, the bendable link pieces 43a and 43b are used as the spacing member 43, but in other embodiments, the spacing member 43 may be a flexible member such as a rope. Good.
[0010]
The tension member 48 is mounted with its base end fixed to the front end 42b of the front mast 42 and its front end fixed to an appropriate position near the front end of the jib 3. The tension member 48 has a pair of left and right. In this embodiment, a rope is used as the tension member 48, and a predetermined number of ropes are connected and formed to have a predetermined length according to the length of the jib 3 to be used. Further, the base end side rope 48a of the tension member 48 is always connected at its base end portion to the front mast front end portion 42b. When the front mast 42 is retracted on the boom side as shown in FIG. The end side rope 48a is stored in a vertically long space provided in the front mast 42. Then, as shown in FIG. 6, when the front mast 42 is tilted forward from the vertical posture, the base end side rope 48a automatically comes out of the vertically long space of the front mast 42 by the weight of the rope. It has become. In another embodiment, a rod may be used as the tension member 48 instead of a rope.
[0011]
One end of a rope 47 having a predetermined length is connected to the distal end portion 41 b of the rear mast 41, and a sheave 46 is attached to the other end of the rope 47. And after winding the rope 45 extended from the winch 44 for jib raising / lowering to the sheave 46, the rope front-end | tip part is being fixed to the turntable 11 side. Here, the rope 45 extended from the winch 44 is indirectly connected to the tip 41b of the rear mast 41 via the sheave 46 and the sheave 46. However, in other embodiments, the rope 45 extends from the winch 44. The tip of the rope 45 may be directly connected to the tip 41b of the rear mast 41.
[0012]
In the assembled state of the jib support device 4, when the winch 44 is operated in the winding direction, the rope 45 is wound around the winch 44, so that the rear mast 41, the spacing member 43, the front mast 42, and When the jib tip 3b is pulled through the tension member 48 to pivot the jib 3 in the jib standing direction, and when the winch 44 is operated in the lowering direction, the rope 45 is unwound from the winch 44. As a result, the jib 3 pivots in the lodging direction with its own weight.
[0013]
Between the rear mast 41 and the front mast 42, a tension member 8 is attached so as to be freely engaged and disengaged so as to prevent the two masts from approaching each other while the spacing member 43 is in tension. As shown in FIG. 3, the tension member 8 uses two links 8a and 8b that can slide in the length direction of each other, and pin-couples the links 8a and 8b in an extended state (reference numeral 8c). By this, it can be connected so that it cannot be bent and contracted. Further, the links 8a and 8b of the tension member 8 are different from each other by a predetermined distance from the proximal end pivotal support portions at the positions close to the proximal end portions of the rear mast 41 and the front mast 42, respectively. When the masts 41 and 42 are opened and closed with the pins 8c connecting the links being removed, the links 8a and 8b automatically slide and extend. Then, both masts are connected by connecting both links 8a and 8b with pins 8c in a state in which both struts 41 and 42 are opened until the spacing member 43 is tensioned (both links 8a and 8b are also extended). A tensioning action is generated between them.
[0014]
Near the boom tip 2a, there are a first telescopic cylinder 6 for raising the front mast 42 in the retracted position, and a second telescopic cylinder 7 for raising the rear mast 41 also in the retracted position. Each is provided. Note that one first telescopic cylinder 6 is used at the middle in the left-right width direction of the boom tip 2b, and one second telescopic cylinder 7 is provided at each end of the boom tip 2b in the left-right width (two in total). )in use.
[0015]
In the first telescopic cylinder 6, the base end portion of the tube located on the lower side is pivotally attached to the boom distal end portion 2b, and the rod is movable up and down. Further, an appropriate position closer to the tip of a thin plate-like support (two on the left and right) 61 having an appropriate length is pivotally attached to the tip of the rod on the movable side. The support 61 is pivotally supported by a shaft 65 at an appropriate position near the base portion on the upper end portion of a support member 64 fixed to the boom tip portion 2b. The support 61 can be swung up and down in a plane parallel to the rocking surfaces of the masts 41 and 42 around the pivot shaft 65 by expanding and contracting the first telescopic cylinder 6. ing. The support 61 has a position closer to the tip thereof serving as a pressing portion 61a for pressing the front mast 42 from below, and a base end portion of the support 61 is used as a receiving portion 63 of a stopper device described later. The pressing portion 61a of the support 61 comes into contact with the engaging portion 66 provided on the front mast 42 from the boom side in an unfixed state. Further, in FIG. 3, the support 61 is positioned in the state shown by the solid line when the first telescopic cylinder 6 is extended to the maximum, and as shown by reference numeral 6 ', the support is shown in the state shown by the chain line (reference numeral 61) when the first telescopic cylinder is fully contracted. ′). At this time, the roller provided on the support 61 'is at the position of 62', and the receiving portion of the stopper device is at the position of 63 '.
[0016]
In the most contracted state of the first telescopic cylinder 6, the pressing portion 61a of the support 61 is positioned below the front mast 42 in the retracted position shown in FIG. The support 61 is rotated by elongating and the engaging portion 66 of the front mast 42 is pressed upward by the pressing portion 61a. When the first telescopic cylinder 6 is extended to the maximum, the front mast 42 can stand up with respect to the rear mast 41 in the retracted position until at least the spacing member 43 is tensioned as shown in FIG. It has become.
[0017]
The second telescopic cylinder (there are two on the left and right) 7 has a tube distal end portion pivotally attached to the boom distal end portion 2b so that its rod can be moved up and down. Further, a swing link 71 is interposed between the tip of the movable rod and the connecting plate pivot shaft 56 at the boom tip 2b. The connecting plate pivot shaft 56 is a swing center of the rear mast 41, and one end of the swing link 71 is pivotally connected to the shaft 56. The rod end portion of the second telescopic cylinder 7 serves as a pressing portion 72 for pressing the rear mast 41 from below. When the second telescopic cylinder 7 expands and contracts, the pressing portion 72 is connected to the shaft 56. The arc moves up and down around the center. The pressing portion 72 comes into contact with the engaging portion 76 provided on the rear mast 41 in an unfixed state from the boom side.
[0018]
In the most contracted state of the second telescopic cylinder 7, the pressing portion 72 is positioned below the rear mast 41 in the retracted position shown in FIGS. 4 and 5, and the second telescopic cylinder 7 is expanded from the state of FIG. By extending the cylinder 7, the pressing portion 72 presses the engaging portion 76 of the rear mast 41 upward. When the second telescopic cylinder 7 is extended to the maximum, the rear mast 41 can be raised by an angle of approximately 90 ° with respect to the axial direction of the boom 2 as shown in FIG. . Further, before extending the second telescopic cylinder 7, as shown in FIG. 5, the projecting member 8 is interposed in a stretched state between the front mast 42 and the rear mast 41 raised by the first telescopic cylinder 6. In other words, when the second telescopic cylinder 7 is extended and the rear mast 41 is pressed, the front mast 42 can be simultaneously rotated forward as shown in FIG. In the state shown in FIG. 6, a tension member 48 having a predetermined length can be interposed between the tip 42 b of the front mast 42 and the appropriate jib.
[0019]
Sheaves 51 and 52 are attached to the tip portions 41b and 42b of the rear mast 41 and the front mast 42, respectively. The sheaves 51 and 52 are attached in common with shafts 51 a and 52 a that pivotally support the outer ends of the front and rear link pieces 43 a and 43 b of the spacing member 43.
[0020]
A loading winch 13 is mounted on the swivel base 11. The leading end side of the rope 14 extended from the loading winch 13 passes through the respective sheaves 51 and 52 provided at the respective leading end portions 41b and 42b of the rear mast 41 and the front mast 42, and further, the jib leading end portion. After passing through the sheave 53 of 3b, it hangs down. A hook 15 is attached to the tip of the rope 14.
[0021]
A stopper device 16 is provided between the jib base end portion 3a and the boom tip end portion 2b to prevent the jib 3 from turning backward beyond the allowable elevation limit angle. The stopper device 16 includes an abutting member 17 provided on the base end side upper portion of the jib 3 and a receiving portion 63 (see FIG. 3) provided on the base end portion of the support 61 of the first telescopic cylinder 6. is doing. As shown in FIG. 3, the receiving portion 63 provided at the base end portion of the support 61 is in a state where the first elongating cylinder 6 is fully extended, and the jib 3 is indicated by the reference numeral 3 ′. When the jib-side abutting member 17 is received when attempting to reverse backward beyond the angle, and when the first telescopic cylinder 6 is reduced as indicated by reference numeral 6 ', the receiving portion 63 is At the position 63 ', the jib 3 is positioned at a position where it cannot receive the abutting member 17 even if it is reversed backward to the position indicated by reference numeral 3'.
[0022]
Thus, in the crane with a jib of this embodiment, by extending and contracting the first telescopic cylinder 6, the receiving portion 63 is placed between a position where the abutting member 17 on the jib 3 side can be received and a position where it cannot be received. Therefore, the operation of changing the stopper device 16 between the use state and the non-use state can be performed only by the extension operation of the first extension cylinder 6.
[0023]
In this crane with a jib, the jib support device 4 is assembled as follows. First, as shown in FIG. 4, the rope 14 from the lifting winch 13 is provided on both the masts 41 and 42 with the boom 2 lying down to a substantially horizontal position and the masts 41 and 42 stored in the boom 2 side. Then, it is guided forward through the sheaves 51 and 52. Next, after the rope 45 from the jib hoisting winch 44 is wound around the sheave 46 at the tip of the rope 47 connected to the tip 41b of the rear mast 41, the tip of the rope 45 is fixed on the swivel base 11. To do. Subsequently, the front mast 42 stored on the boom 2 side by the pressing portion 61a of the support 61 is shown by extending the first telescopic cylinder 6 in a state where the links 8a and 8b of the tension member 8 are freely stretchable. As shown in FIG. 5, the distance holding member 43 is raised until it is tensioned. At this time, the rear mast 41 remains lying on the boom 2 side due to its own weight, and only the front mast 42 is raised so that the front and rear link pieces 43a and 43b of the spacing member 43 are bent as shown in FIG. It automatically releases from the state and tensions in a straight line. Further, both links 8a and 8b of the tension member 8 are automatically extended.
[0024]
Next, in this state, the two masts 41 and 42 are stretched by the stretching member 8, and in this case, the both extended links 8a and 8b need only be connected by the pin 8c. Next, the second telescopic cylinder 7 is extended, and the pressing portion 72 presses the rear mast 41 stored on the boom 2 side, and the front mast 42 together with the rear mast 41 is also indirectly jibbed. The masts 41 and 42 are raised up to the positions shown in FIG. At this time, the base end side rope 48a of the tension member stored in the vertically long space of the front side mast 42 automatically hangs downward, and the length of the jib 3 is set at the end of the base end side rope 48a. Correspondingly, an appropriate number of ropes are connected to form a tension member 48 having a predetermined length. When the tip 42b of the front mast 42 and an appropriate position (tip 3b) of the jib 3 are connected by the tension member 48, the assembly work of the jib support device 4 is completed.
[0025]
[Patent Document 1]
JP 7-215672 A
[0026]
[Problems to be solved by the invention]
However, in such a crane with a jib, when the work of the jib 3 is inadvertently performed with the second telescopic cylinder 7 extended as shown in FIG. Since the second telescopic cylinder 7 protrudes from the tip of the telescopic boom 2, the jib 3 may be brought into contact with the second telescopic cylinder 7 to damage both members.
[0027]
That is, when the angle of the jib 3 with respect to the telescopic boom 2 is an angle in which the jib 3 is brought close to the distal end of the telescopic boom 2, the jib 3 is placed on the second telescopic cylinder 7 protruding from the distal end of the telescopic boom 2. May come into contact. Therefore, after extending the second telescopic cylinder 7 and raising the masts 41 and 42, it is necessary to reduce the second telescopic cylinder 7 without forgetting.
[0028]
An object of the present invention is to provide a safety device for a crane with a jib that prevents the jib 3 from being inadvertently brought into contact with the second telescopic cylinder 7 to damage both members.
[0029]
[Means for Solving the Problems]
In order to achieve the above object, a safety device for a crane with a jib according to claim 1 of the present invention includes a jib pivotally supported at the tip of a telescopic boom that can be driven up and down, and telescopic at the tip of the telescopic boom. Two front and rear masts pivotably mounted in the jib undulation trajectory plane on the rear side of the boom, a distance holding member for holding a distance between the front mast and the rear mast, and a front end portion of the front mast; A tension member that connects the appropriate position of the jib, a winch for raising and lowering the jib provided on the base end of the telescopic boom, and a rope that extends from the winch and is connected directly or indirectly to the tip of the rear mast. The front mast and the rear mast are provided on the back side of the telescopic boom while the base ends of both masts are pivotally attached to the distal end of the telescopic boom with the tension member being disconnected. In It is possible to fall down to the retracted retracting position, and by extending the hydraulic cylinder provided near the tip of the telescopic boom, the front and rear masts in the retracted position are pressed in a non-fixed state and the tension between the front end of the front mast and the appropriate position of the jib With a jib so that it can stand up to a position where a member can be interposed, and the hydraulic cylinder is located in the distal end of the telescopic boom when contracted and extended to project below the boom distal end when pressing the front and rear masts In the crane, The hydraulic cylinder is configured to be able to be reduced in a state where the mast is raised, A hydraulic cylinder expansion / contraction detection means for detecting the expansion / contraction state of the hydraulic cylinder; and a controller that controls the operation of the jib crane when the hydraulic cylinder is not in a contracted state in response to a detection signal from the detection means. It is a feature.
[0030]
The safety device for a crane with a jib according to claim 2 of the present invention includes a jib pivotally supported at the tip of a telescopic boom that can be driven up and down, and a jib hoisting locus on the back side of the telescopic boom at the tip of the telescopic boom. Two front and rear masts pivotably mounted in a plane, a distance holding member for maintaining a distance between the front mast and the rear mast, and a tension for connecting the front end portion of the front mast and a proper position of the jib A crane with a jib comprising a member, a winch for raising and lowering a jib provided on the base end side of the telescopic boom, and a rope extending from the winch and directly or indirectly connected to the tip of the rear mast The front mast and rear mast can be collapsed to the retracted position close to the rear side of the telescopic boom while the base ends of both masts are pivotally attached to the distal end of the telescopic boom with the tension member disconnected. The tension member can be interposed between the front end portion of the front mast and the appropriate position of the jib by pressing the front and rear mast in the retracted position by extending a hydraulic cylinder provided near the front end portion of the telescopic boom. In the crane with a jib arranged so that the hydraulic cylinder can stand up to a position and is located in the distal end of the telescopic boom when retracted and is extended and protrudes below the boom distal end when pressing the front and rear masts. The hydraulic cylinder expansion / contraction detection means for detecting the expansion / contraction state of the jib, the jib undulation angle detection means for detecting the undulation angle of the jib, and the hydraulic cylinder is not in the contracted state and receives the detection signals from both detection means And a controller that regulates the operation of the crane with the jib when the angle becomes below a predetermined angle. .
[0031]
The safety device for a crane with a jib according to claim 3 is the safety device for a crane with a jib according to claim 1 or 2, wherein the operation restriction of the crane with a jib controlled by the controller is: Restricts the movement of the jib relative to the telescopic boom in the direction of decreasing angle It is characterized by doing so.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a cargo handling apparatus A for a truck according to the present invention will be described with reference to FIGS. In addition, since the case where the safety device of the crane with a jib of this invention was used for the crane with a jib illustrated and described in FIGS. 1 to 7 in the prior art will be described below, it has been illustrated and described with reference to FIGS. The same reference numerals are used in the following description.
[0033]
The safety device for a crane with a jib of the present invention is shown in FIG. In FIG. 8, reference numeral 100 denotes an operating device, which receives an operation signal from each operation means described below and outputs a drive signal to each drive means. Reference numeral 110 denotes a first telescopic cylinder operating means that operates to operate the first telescopic cylinder 6. Reference numeral 111 denotes first telescopic cylinder driving means for driving the first telescopic cylinder 6 based on an output signal output from the operating device 100 based on an operation signal of the first telescopic cylinder operating means 110.
[0034]
Reference numeral 120 denotes second telescopic cylinder operating means that is operated to operate the second telescopic cylinder 7. Reference numeral 121 denotes a second telescopic cylinder driving unit that drives the second telescopic cylinder 7 based on an output signal output from the operating device 100 based on an operation signal from the second telescopic cylinder operating unit 120.
[0035]
Reference numeral 130 denotes a lifting winch operating means for operating the lifting winch 13. 131 is a lifting winch drive means for driving the lifting winch 13 based on an output signal output from the operating device 100 based on an operation signal of the lifting winch operation means 130.
[0036]
Reference numeral 140 denotes a jib hoisting winch operating means for operating the jib hoisting winch 44. 141 is a jib hoisting winch driving means for driving the jib hoisting winch 44 based on the output signal output from the operating device 100 based on the operation signal of the jib hoisting winch operating means 140.
[0037]
Reference numeral 150 denotes telescopic boom hoisting operation means that is operated to operate the hoisting cylinder 21. Reference numeral 151 denotes a telescopic boom hoisting driving unit that drives the hoisting cylinder 21 based on an output signal output from the operating device 100 based on an operation signal of the telescopic boom hoisting operating unit 150.
[0038]
Reference numeral 160 denotes a telescopic boom telescopic operation means operated to operate the telescopic cylinder (not shown) built in the telescopic boom 2 described above. Reference numeral 161 denotes a telescopic boom telescopic drive unit that drives the telescopic cylinder based on an output signal output from the operation device 100 based on an operation signal of the telescopic boom telescopic operation unit 160.
[0039]
Thus, the operating device 100 receives the operation signal from each operation means, and outputs a drive signal to each drive means arranged corresponding to each operation means in accordance with each operation signal.
[0040]
Reference numeral 180 denotes hydraulic cylinder expansion / contraction detection means for detecting the expansion / contraction state of the second expansion / contraction cylinder 7 (corresponding to the hydraulic cylinder according to claim 1). Reference numeral 170 denotes a restriction control device that receives a signal from the hydraulic cylinder expansion / contraction detection means 180 and outputs a restriction signal to the next restriction means when the second expansion cylinder 7 is not fully contracted.
[0041]
142 is a jib hoisting winch lowering restricting means interposed between the operating device 100 and the jib hoisting winch driving means 141, and receives the restriction signal from the restriction control device 170 to wind the jib hoisting winch 44. This is a jib hoisting winch lowering restricting means for restricting the lowering drive. Reference numeral 152 denotes a telescopic boom raising / lowering restricting means interposed between the operation device 100 and the telescopic boom raising / lowering driving means 151, which receives a restriction signal from the restriction control device 170 to restrict the telescopic boom to the raising / lowering side ( Telescopic boom raising and lowering restricting means for restricting the hoisting cylinder 21 to the extending side). Reference numeral 162 denotes a telescopic boom reduction restricting means interposed between the operation device 100 and the telescopic boom extension / contraction drive means 161, which receives a restriction signal from the restriction control device 170 and restricts the telescopic boom to the reduction side (the extension / contraction). This is a telescopic boom reduction restricting means for restricting the cylinder to the reduction side).
[0042]
Reference numeral 200 denotes a controller, which includes the operation device 100, a restriction control device 170, a jib hoisting winch lowering restricting means 142, an extendable boom raising restricting means 152, and an extendable boom reduction restricting means 162.
[0043]
The safety device for a crane with a jib according to the present invention configured as described above operates as follows. In the state where the assembly work of the jib support device 4 is completed, the next operation of using the jib work is restricted while the second telescopic cylinder 7 is extended as shown in FIG. That is, when the second telescopic cylinder 7 is kept extended, the hydraulic cylinder expansion / contraction detection means 180 detects the expansion / contraction state of the second expansion cylinder 7, and the restriction control device 170 of the controller 200 In response to the detection signal from the expansion / contraction detection means 180, the second expansion cylinder 7 is determined not to be fully contracted, and the jib hoisting winch lowering restriction means 142, the expansion / contraction boom raising / lowering restriction means 152, and the expansion / contraction boom reduction restriction means 162. A restriction signal is output to each restriction means.
[0044]
Then, the movement of the jib 3 in the direction in which the undulation angle of the jib 3 with respect to the telescopic boom 2 is restricted can be prevented, and the jib 3 can be brought into contact with the second telescopic cylinder 7 to prevent both members from being damaged. Accordingly, even if the second telescopic cylinder 7 is inadvertently extended and the jib 3 is inadvertently attempted to work, the jib 3 can be prevented from coming into contact with the second telescopic cylinder 7.
[0045]
Next, in the above-described embodiment, when the second hydraulic cylinder 7 is extended, the restriction control device 170 of the controller 200 causes the restriction means 142, 152, 162 to act. Even when the jib 3 is extended, the above-described restrictions may not be applied when the jib undulation angle is such that the jib 3 does not come into contact with the tip of the telescopic boom 2. This case is illustrated in FIG. 9 and described below.
[0046]
In FIG. 9, reference numeral 190 denotes a jib undulation angle detection unit that detects a machine angle of the jib 3 with respect to the telescopic boom 2. A restriction control device 171 receives detection signals from the hydraulic cylinder expansion / contraction detection means 180 and the jib undulation angle detection means 190, determines that the second expansion cylinder 7 is not fully contracted, and has a predetermined jib undulation angle. When the angle is equal to or less than the undulation angle, a restriction signal is output to each of the restricting means of the jib hoisting winch lowering restricting means 142, the telescopic boom raising / lowering restricting means 152, and the telescopic boom reduction restricting means 162. Reference numeral 201 denotes a controller, which includes the operation device 100, a restriction control device 171, a jib hoisting winch lowering restriction means 142, a telescopic boom lifting restriction means 152, and a telescopic boom reduction restriction means 162.
[0047]
In this case, even if the second telescopic cylinder 7 is extended, the restriction is not performed if the undulation angle of the jib 3 with respect to the telescopic boom 2 is equal to or greater than a predetermined value. Therefore, even if the second telescopic cylinder 7 is extended, it is possible to eliminate as much restriction as necessary. Also in the present embodiment, when the jib 3 comes into contact with the second telescopic cylinder 7, the operation in the direction in which the undulation angle of the jib 3 with respect to the telescopic boom 2 is reduced is restricted, and the second telescopic cylinder 7 is It is possible to prevent the jib 3 from contacting and damaging both members. Accordingly, even if the second telescopic cylinder 7 is inadvertently extended and the jib 3 is inadvertently attempted to work, the jib 3 can be prevented from coming into contact with the second telescopic cylinder 7.
[0048]
Further, in the above embodiment, the jib undulation angle detection means 190 is constituted by the undulation angle detection means for detecting the machine angle of the jib 3 with respect to the telescopic boom 2, but the jib undulation angle detection means 191 is as shown in FIG. The jib undulation angle detection means 192 for detecting the ground angle and the telescopic boom undulation angle detection means 193 for detecting the ground angle may be used. That is, 192 is a jib undulation angle detection unit that detects the ground angle of the jib 3, and 193 is an expansion boom undulation angle detection unit that detects the ground angle of the telescopic boom 2. Reference numeral 172 denotes a restriction control device that receives detection signals from both detection means 192 and 193 to determine whether or not the angle of the jib 3 with respect to the telescopic boom 2 is equal to or less than a predetermined angle. Then, when the machine angle of the jib 3 with respect to the telescopic boom 2 is equal to or less than a predetermined angle and the second telescopic cylinder 7 is determined not to be fully contracted in response to the detection signal from the hydraulic cylinder expansion / contraction detection means 180, the same as described above. A restriction signal is output to each of the restriction means of the jib hoisting winch lowering restricting means 142, the extendable boom raising restricting means 152, and the extendable boom reduction restricting means 162. Reference numeral 202 denotes a controller, which includes the operation device 100, a restriction control device 172, a jib hoisting winch lowering restriction means 142, a telescopic boom raising / lowering restriction means 152, and a telescopic boom reduction restriction means 162.
[0049]
In this case, even if the second telescopic cylinder 7 is extended, the restriction is not performed if the undulation angle of the jib 3 with respect to the telescopic boom 2 is equal to or larger than a predetermined value. Therefore, even if the second telescopic cylinder 7 is extended, it is possible to eliminate as much restriction as necessary. Furthermore, such a crane with a jib is equipped with various safety devices, and a jib undulation angle detection means 192 for detecting the ground angle and a telescopic boom undulation angle detection means 193 are used as detection means for the various safety devices. It can be shared with these detection means.
[0050]
Also in the present embodiment, when the jib 3 comes into contact with the second telescopic cylinder 7, the operation in the direction in which the undulation angle of the jib 3 with respect to the telescopic boom 2 is reduced is restricted, and the second telescopic cylinder 7 is Of course, it is possible to prevent both members from being damaged by contacting the jib 3. Accordingly, even if the second telescopic cylinder 7 is inadvertently extended and the jib 3 is inadvertently attempted to work, the jib 3 can be prevented from coming into contact with the second telescopic cylinder 7.
[0051]
In the above-described embodiment, each regulation control device 170, 171, 172 receives the detection signal from the hydraulic cylinder expansion / contraction detection means 180 and determines whether or not the second expansion cylinder 7 is in the fully contracted state. However, the second telescopic cylinder 7 may be in a telescopic state that does not protrude from the distal end portion of the telescopic boom 2, and depending on the mounting state of the second telescopic cylinder 7, it does not necessarily protrude even if it is not fully contracted. it can. In such a case, the reduced state of the second telescopic cylinder 7 that does not protrude may be detected.
[0052]
Further, each of the restriction control devices 171 and 172 receives detection signals from the hydraulic cylinder expansion / contraction detection means 180 and the jib undulation angle detection means 190 and 191, and depending on the expansion / contraction state of the second expansion cylinder 7, A restriction signal may be output to each of the restriction means 142, 152, 162 so as to determine a restriction range in a direction in which the undulation angle decreases.
[0053]
Further, in the above embodiment, the direction in which the undulation angle of the jib 3 with respect to the telescopic boom 2 is reduced by the respective control means of the jib hoisting winch lowering restricting means 142, the telescopic boom raising and lowering restricting means 152, and the telescopic boom reduction restricting means 162. The operation of the crane with the jib is regulated, but when the above state is reached, the regulation control devices 170, 171 and 172 regulate all the operations of the crane with the jib (the first telescopic cylinder 6 and the second The operation of the telescopic cylinder 7 is not restricted.) In this case, the restriction is released by fully reducing the second telescopic cylinder 7.
[0054]
Next, in the above embodiment, the front mast 42 is raised by the extension of the first telescopic cylinder 6, and the front mast 42 and the rear mast 41 are stretched by the tension member 8, and the second telescopic cylinder 7 is elongated. Although the front mast 42 and the rear mast 41 are erected, the front mast 42 may be erected directly by the second telescopic cylinder 7. In this case, the expansion / contraction stroke of the second expansion / contraction cylinder 7 may be lengthened, and the mast 41 may be erected after the front mast 42 is erected and connected by the spacing member 43.
[0055]
Even if it is a case where it comprises in this way, even if the 2nd expansion-contraction cylinder 7 protrudes from the front-end | tip part of the expansion-contraction boom 2 when the 2nd expansion-contraction cylinder 7 is extended | expanded, it is the safety device of the crane with a jib of this invention similarly. Of course, it is possible to prevent the jib 3 from coming into contact with the second telescopic cylinder 7.
[0056]
【The invention's effect】
Since the safety device for a crane with a jib according to the first aspect of the present invention is configured and operates as described above, the operation by the jib is inadvertently performed while the hydraulic cylinder (second telescopic cylinder) is extended. Even when trying to do so, the operation of the crane with the jib can be restricted, and the jib can be brought into contact with the hydraulic cylinder (second telescopic cylinder) to prevent both members from being damaged.
[0057]
Since the safety device for a crane with a jib of the present invention according to claim 2 is configured and operates as described above, the operation by the jib is inadvertently performed while the hydraulic cylinder (second telescopic cylinder) is extended. Even when trying to do so, the operation of the crane with the jib can be restricted, and the jib can be brought into contact with the hydraulic cylinder (second telescopic cylinder) to prevent both members from being damaged. Further, if the undulation angle of the jib with respect to the telescopic boom is equal to or greater than a predetermined value, the regulation is not performed, and even if the hydraulic cylinder (second telescopic cylinder) is extended, it is possible to eliminate as much regulation as necessary. .
[0058]
A safety device for a crane with a jib according to a third aspect of the present invention is the safety device for a crane with a jib according to the first or second aspect, wherein the rope is fed out from a winch for raising and lowering the jib, and the telescopic boom is raised. The movement of the telescopic boom and the movement of the telescopic boom to restrict the movement of the crane with the jib in the direction in which the undulation angle of the jib with respect to the telescopic boom is reduced, and the jib is brought into contact with the hydraulic cylinder (second telescopic cylinder) Thus, it is possible to prevent both members from being damaged and not to restrict operations not related to bringing the jib into contact with the hydraulic cylinder (second telescopic cylinder).
[Brief description of the drawings]
FIG. 1 is an overall side view showing a use state of a crane with a jib.
FIG. 2 is a partially enlarged view of FIG.
FIG. 3 is a partially enlarged longitudinal sectional view of FIG. 2;
4 is an explanatory view showing a retracted state in which the front mast and the rear mast in the crane with the jib shown in FIG. 1 are laid down. FIG.
FIG. 5 is an explanatory view showing a state in which the front mast is raised from the state of FIG. 4;
6 is an explanatory view showing a state in which the rear mast is raised from the state shown in FIG.
7 is an explanatory diagram of a jib swinging method of the crane with the jib shown in FIG. 1. FIG.
FIG. 8 is an explanatory diagram illustrating a safety device for a crane with a jib according to the present invention.
FIG. 9 is an explanatory view illustrating a safety device for a crane with a jib according to the present invention and is an explanatory view illustrating another embodiment.
FIG. 10 is an explanatory view for explaining another embodiment of the safety device for a crane with a jib according to the present invention.
[Explanation of symbols]
2 Telescopic boom
3 Jib
7 Hydraulic cylinder (second telescopic cylinder)
41 Rear mast
42 front mast
43 Spacing member
48 Tension member
44 Jib hoisting winch
45 rope
180 Hydraulic cylinder expansion / contraction detection means
190 Jib undulation angle detection means
191 Jib undulation angle detection means
200 controller
201 controller
202 controller

Claims (3)

A jib pivotally supported at the tip of a telescopic boom that can be driven up and down, and two front and rear masts pivotably mounted on the back of the telescopic boom at the tip of the telescopic boom in a jib hoisting locus plane. A gap holding member that holds the gap between the front mast and the rear mast, a tension member that connects the front end portion of the front mast and the appropriate position of the jib, and a jib hoisting provided on the base end side of the telescopic boom A crane with a jib, and a rope extending from the winch and directly or indirectly connected to the tip of the rear mast,
The front mast and the rear mast can be laid down to the retracted position close to the rear side of the telescopic boom while the base end of both masts is pivotally attached to the distal end of the telescopic boom with the tension member disconnected. A position where the tension member can be interposed between the front end portion of the front mast and the appropriate position of the jib by pressing the front and rear masts in the retracted position by extending a hydraulic cylinder provided near the front end portion of the telescopic boom. In the crane with the jib arranged so that the hydraulic cylinder is positioned in the distal end of the telescopic boom at the time of contraction and extends to protrude below the distal end of the boom when the front and rear masts are pressed,
The hydraulic cylinder is configured to be able to be reduced when the mast is raised, and a hydraulic cylinder expansion / contraction detection means for detecting an expansion / contraction state of the hydraulic cylinder, and a detection signal from the detection means is received, and the hydraulic cylinder is not in the reduction state A safety device for a crane with a jib, comprising a controller for regulating the operation of the crane with a jib. A jib pivotally supported at the tip of a telescopic boom that can be driven up and down, and two front and rear masts pivotably mounted on the back of the telescopic boom at the tip of the telescopic boom in a jib hoisting locus plane. A gap holding member that holds the gap between the front mast and the rear mast, a tension member that connects the front end portion of the front mast and the appropriate position of the jib, and a jib hoisting provided on the base end side of the telescopic boom A crane with a jib, and a rope extending from the winch and directly or indirectly connected to the tip of the rear mast,
The front mast and the rear mast can be laid down to the retracted position close to the rear side of the telescopic boom while the base end of both masts is pivotally attached to the distal end of the telescopic boom with the tension member disconnected. A position where the tension member can be interposed between the front end portion of the front mast and the appropriate position of the jib by pressing the front and rear masts in the retracted position by extending a hydraulic cylinder provided near the front end portion of the telescopic boom. In the crane with the jib arranged so that the hydraulic cylinder is positioned in the distal end of the telescopic boom at the time of contraction and extends to protrude below the distal end of the boom when the front and rear masts are pressed,
The hydraulic cylinder expansion / contraction detection means for detecting the expansion / contraction state of the hydraulic cylinder, the jib undulation angle detection means for detecting the jib undulation angle, and the detection signal from both detection means, the hydraulic cylinder is not in the contracted state and the jib A safety device for a crane with a jib, comprising: a controller that regulates the operation of the crane with a jib when the undulation angle of the crane becomes equal to or less than a predetermined angle. 3. The safety device for a crane with a jib according to claim 1, wherein the operation restriction of the crane with the jib controlled by the controller is to restrict the movement of the jib with respect to the telescopic boom in a direction in which the undulation angle decreases. A safety device for a crane with a jib characterized by the above.

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