JP2018100175A - Expansion/contraction control device for boom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extension/contraction control device for a boom with a simple structure in which a height position of a hook block is maintained substantially constant when a boom is extended even when the winding number of a wire rope is changed.SOLUTION: A boom extension/contraction device 50 includes a winding number input device 35 into which the winding number n of a wire rope 34 wound on a hook block 40 is input and a drive control device 33 controlling to vary the speed of extending/contracting a telescopic boom 21 in accordance with the operation amount input into a boom telescopic operation lever 30 into which an operation for extending/contracting the telescopic boom 21 is input. The drive control device 33 controls a boom telescopic cylinder such that the extension speed of the telescopic boom 21 becomes equal to or less than a limit value when an extension speed of the telescopic boom 21 according to the operation amount of the boom telescopic operation lever 30 exceeds the speed of the limit value obtained by dividing a delivery speed of the wire rope 34 according to the operation amount of a winch operation lever 32 by the winding number n.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a boom telescopic control device.

  A crane hangs a load on a hook of a hook block suspended from a sheave provided at the tip of the boom (boom head). The hook block is hung on a wire rope wound around a winch. Then, the hook block is raised by winding the wire rope with the winch, and the hook block is lowered by feeding the wire rope.

  Here, in the case of a boom that has two or more booms and expands and contracts as a whole, by extending the boom, the wire rope stretched along the boom is drawn to the boom side, and as a result, the hook block becomes a sheave. The hook block hits the sheave before approaching the tip. Therefore, when the boom is extended, the winch is operated together to feed out the wire rope.

  The boom changes according to the amount by which the boom telescopic operation lever is tilted, and the rotation speed of the winch also varies according to the amount by which the winch operation lever is tilted. Therefore, when the wire rope feeding speed by the winch is slower than the boom extending speed, the hook block approaches the sheave. For this reason, an operator who operates the crane adjusts the amount of the two operation levers to tilt while watching the position of the hook with respect to the tip of the boom so that the hook block does not approach the tip of the boom. As described above, it is difficult to perform the boom telescopic operation and the winch operation in parallel, which depends on the operation skill of the operator.

  In view of this, there has been proposed an apparatus that facilitates the operation by interlocking the boom expansion / contraction operation and the winch operation (wire rope feeding / winding operation) (for example, see Patent Document 1). The apparatus of Patent Document 1 makes the distance between the hook block and the sheave constant by synchronizing the boom expansion / contraction operation and the winch operation by communicating the boom expansion / contraction hydraulic cylinder and the winch hydraulic motor. Or keep the height of the hook block constant.

JP-A-11-171474

  By the way, the ascending speed (winding speed) and the descending speed (winding speed) of the hook block vary depending on the number of wire ropes between the hook block and the sheave. That is, in the case of so-called two hooks in which the wire rope hung on the boom head sheave is hooked on the hook block sheave and the tip of the wire rope is fixed on the boom head, the hook block hoisting speed and lowering The speed is one half of the winding speed of the wire rope by the winch and the feeding speed. Similarly, in the case of four hooks, the hoisting speed and lowering speed of the hook block are a quarter of the hoisting speed and the feeding speed of the wire rope.

  Therefore, the boom expansion / contraction operation and the winch operation cannot be synchronized only by connecting the boom extending / contracting hydraulic cylinder and the winch hydraulic motor to each other when a plurality of wire ropes are hooked.

  In addition, the apparatus of Patent Document 1 requires a new hydraulic circuit such as a switching valve and a pipe for switching between the hydraulic circuit for extending and retracting the boom and the hydraulic circuit for the winch, and the configuration becomes complicated.

  The present invention has been made in view of the above circumstances, and has a simple configuration and can keep the height of the hook block substantially constant when the boom is extended and contracted even when the number of wire ropes is changed. An object of the present invention is to provide a telescopic control device.

  The present invention relates to a multiplier input device for inputting a multiplication factor of a wire rope to a hook block, and a boom expansion / contraction operation unit to which an operation for expanding / contracting the boom is input to a boom expansion / contraction drive unit for expanding / contracting the boom. Control to change the speed at which the boom is expanded and contracted according to the operation amount input to the control unit, and the operation of feeding out the wire rope to the winch drive unit that feeds and winds up the wire rope wound around the winch, or A drive control device that controls to change the speed at which the wire rope is fed out and the speed at which the wire rope is wound up according to the operation amount input to the winch operation unit to which the operation for winding is input, and the drive control device includes the boom The boom expansion / contraction speed corresponding to the operation amount input to the telescopic operation unit is input to the winch operation unit. When the wire rope feeding speed or the wire rope winding speed according to the operation amount exceeds the speed of the limit value obtained by dividing by the multiplier input to the multiplier input device, The boom expansion / contraction control device controls the boom expansion / contraction drive unit so that the boom expansion / contraction speed is equal to or less than the limit value regardless of the operation amount input to the boom expansion / contraction operation unit.

  According to the boom extension / contraction control device of the present invention, the height of the hook block can be kept substantially constant when the boom is extended / contracted even if the number of wire ropes is changed with a simple configuration.

It is the side view which looked at the rough terrain crane provided with the expansion-contraction control apparatus of the boom in one Embodiment of this invention from the right side. It is a block diagram of the structure containing the expansion-contraction control apparatus of the boom applied to the rough terrain crane shown in FIG. It is a graph which shows the correspondence of the operation amount input into the boom expansion-contraction operation lever, and the expansion-contraction speed of an expansion-contraction boom. It is a graph which shows the correspondence of the operation amount input into the winch operation lever, the drawing | feeding-out speed | rate of a wire rope, and a winding speed. A graph showing a correspondence relationship between the operation amount input to the winch operation lever and the lowering speed and the rising speed of the hook block suspended from the wire rope when the telescopic boom is not expanded or contracted (when the telescopic speed is zero). It is.

  DESCRIPTION OF EMBODIMENTS Embodiments of a boom extension / contraction control device according to the present invention will be described below with reference to the drawings.

<Schematic configuration of crane>
FIG. 1 is a side view of a rough terrain crane 100 (hereinafter simply referred to as a crane 100) provided with a boom telescopic control device according to an embodiment of the present invention, and FIG. 2 is a rough terrain shown in FIG. 1 is a block diagram of a configuration including a boom expansion / contraction control device 50 applied to a crane 100. FIG. The boom telescopic control device 50 is not only applied to the telescopic boom provided in the rough terrain crane 100, but can be applied to all terrain cranes, truck cranes, and loadable truck cranes as long as the crane is provided with telescopic booms. Can be applied.

  As shown in FIG. 1, the crane 100 includes a vehicle unit 10 that is a main body portion of a vehicle having a traveling function, a vehicle unit 10, and a crane working unit 20. The vehicle unit 10 includes a vehicle body 11, outriggers 12 provided at four corners of the vehicle body 11, a swivel base 13 attached to the car body 11 so as to be horizontally turnable, a bracket 14 and a cabin 15 installed on the swivel base 13. And.

  The crane working unit 20 includes a telescopic boom 21, a boom telescopic cylinder 26 (an example of a boom telescopic drive unit), a boom hoisting cylinder 27, a winch 28, a winch motor 29 (an example of a winch drive unit), and a boom telescopic operation. A lever 30, a boom raising / lowering operation lever 31, a winch operation lever 32, a drive control device 33, and a hook block 40 are provided.

  The telescopic boom 21 is attached to the bracket 14. The telescopic boom 21 includes a first boom 22 disposed on the proximal end (rear end) side closest to the bracket 14, a third boom 24 disposed farthest from the bracket 14 and disposed on the distal end side, and the first boom 22. A second boom 23 disposed between the third boom 24 and sheaves 25 a and 25 b provided at the tip (boom head) of the third boom 24 are provided. The first boom 22 is rotatably attached to a support shaft that is horizontally installed on the bracket 14 at the base.

  When the telescopic boom 21 is in the contracted state, the third boom 24 is nested in the space inside the second boom 23, and the second boom 23 is nested in the space inside the first boom 22. Is housed in. When the telescopic boom 21 is extended, the second boom 23 protrudes from the first boom 22 in the axial direction of the first boom 22, and the third boom 24 extends from the second boom 23 to the axial direction of the second boom 23. Protrusively. FIG. 1 shows a state in which the telescopic boom 21 is extended in length.

  The boom telescopic cylinder 26 is disposed inside the telescopic boom 21. The boom telescopic cylinder 26 expands and contracts, thereby extending or retracting the telescopic boom 21 by causing the second boom 23 and the third boom 24 to protrude or accommodate as described above. The boom telescopic operation lever 30 is provided in the cabin 15, and an operation for extending and retracting the telescopic boom 21 by the operator is input.

  The boom hoisting cylinder 27 is arranged so as to be bridged between the bracket 14 and the first boom 22. The boom hoisting cylinder 27 extends and retracts, thereby rotating the entire telescopic boom 21 around the support shaft to raise and lower the telescopic boom 21. The boom raising / lowering operation lever 31 is provided in the cabin 15, and an operation for raising and lowering the telescopic boom 21 by an operator is input.

  The winch 28 and the winch motor 29 that rotates the winch 28 are arranged on the swivel base 13 near the base end of the telescopic boom 21. The winch 28 is a drum on which a wire rope 34 for suspending a load is wound. The winch 28 is rotated by a winch motor 29 to feed out or wind up the wound wire rope 34. The winch operation lever 32 is provided in the cabin 15, and an operation for feeding out and winding up the wire rope 34 by the operator is input.

  The wire rope 34 wound around the winch 28 is hung on the sheaves 25a and 25b provided on the boom head of the telescopic boom 21, and hung on the sheave 42 of the hook block 40 including the hook 41 for hanging the load. The tip is fixed to the boom head. Therefore, when the telescopic boom 21 is not performing the telescopic operation, when the wire rope 34 is extended, the length (hanging length) between the boom head and the hook block 40 becomes long, and the wire rope 34 is wound up. The suspension length is shortened.

  Here, the wire rope 34 can reciprocate between the sheave 25 b provided on the boom head and the sheave 42 provided on the hook block 40, so that the hook block 40 can be supported by a plurality of wire ropes 34. . That is, in the state shown in FIG. 1, the wire rope 34 hung on the sheave 25b is hung on the sheave 42 of the hook block 40 and returned to the boom head side, and the tip of the wire rope 34 is fixed to the boom head. . Therefore, the hook block 40 is supported by the two wire ropes 34. In this case, the multiplier n of the wire rope 34 is 2.

  The multiplication number n can be changed according to the number of sheaves 25b provided on the boom head and the number of sheaves 42 provided on the hook block 40. Also in this embodiment, the multiplication number n is not limited to two. 1 or 3 or more.

<Drive control device>
The drive control device 33 is provided in the cabin 15. The drive control device 33 controls the boom telescopic cylinder 26 to change the speed at which the telescopic boom 21 is expanded and contracted according to the operation amount input to the boom telescopic operation lever 30, and to the boom hoisting cylinder 27. Then, the telescopic boom 21 is controlled to be raised and lowered according to the operation amount input to the boom raising and lowering operation lever 31.

  In other words, the drive control device 33 increases the speed at which the boom telescopic cylinder 26 extends (extension speed) as the amount by which the boom telescopic operation lever 30 is tilted forward from the initial reference position (operation amount) increases. To control. Further, the drive control device 33 controls the boom expansion / contraction operation lever 30 to increase the reduction speed for shortening the boom expansion / contraction cylinder 26 as the amount (operation amount) of tilting the boom expansion / contraction operation lever 30 backward from the initial reference position increases. .

  FIG. 3 is a graph showing a correspondence relationship between the operation amount input to the boom telescopic operation lever 30 and the telescopic speed of the telescopic boom 21. Specifically, as shown in FIG. 3, the drive control device 33 performs control so that the expansion / contraction speed (extension speed and reduction speed) is directly proportional to the operation amount. This control can also be performed with a configuration provided with an electromagnetic proportional valve that adjusts the flow rate of hydraulic oil to the boom telescopic cylinder 26. In addition, since the range in which the operation amount of the boom extending / contracting operation lever 30 is extremely small is a dead zone, the expansion / contraction speed is zero regardless of the operation amount.

  Further, the drive control device 33 controls the boom raising / lowering operation lever 31 so as to increase the speed at which the boom raising / lowering cylinder 27 rises / lowers as the amount of tilting the boom raising / lowering operation lever 31 from the initial reference position increases. The boom raising / lowering operation lever 31 accepts input of an operation of tilting forward from the reference position and an operation of tilting backward, and the drive control device 33 extends / contracts by tilting the telescopic boom 21 downward and tilting backward. The boom hoisting cylinder 27 is controlled to raise the boom 21.

  Further, the drive control device 33 causes the winch motor 29 to change the speed of drawing out the wire rope 34 (feeding speed) and the speed of winding (winding speed) according to the operation amount input to the winch operation lever 32. To control.

  In other words, the drive control device 33 controls the wire rope 34 so that the feeding speed of the wire rope 34 increases as the amount (operation amount) of the winch operation lever 32 tilted forward from the initial reference position increases. Further, the drive control device 33 controls the winding speed of the wire rope 34 to be increased as the amount of tilting the winch operation lever 32 backward from the initial reference position (operation amount) increases.

  FIG. 4 is a graph showing a correspondence relationship between the operation amount input to the winch operation lever 32, the feeding speed and the winding speed of the wire rope 34. Specifically, as shown in FIG. 4, the drive control device 33 performs control so that the feeding speed and the winding speed are directly proportional to the operation amount. This control can also be performed with a configuration provided with an electromagnetic proportional valve that adjusts the flow rate of hydraulic oil to the winch motor 29. Since the range where the operation amount of the winch operation lever 32 is very small is a dead zone, the feeding speed and the winding speed are zero regardless of the operation amount.

  FIG. 5 shows the operation amount input to the winch operation lever 32 and the descending speed and ascending of the hook block 40 suspended from the wire rope 34 when the telescopic boom 21 is not expanded or contracted (when the telescopic speed is zero). It is a graph which shows the correspondence with speed. In the graph, the solid line indicates the correspondence between the lowering speed and the rising speed of the hook block 40 when the multiplication number n is 1 (one multiplication), and the broken line indicates the hook block 40 when the multiplication number n is 2 (two multiplications). , The dash-dot line represents the correspondence between the descent speed and the ascending speed of the hook block 40 when the multiplication factor n is 3 (three), and the two-dot chain line represents the multiplication factor n of 4. The correspondence relationship between the lowering speed and the rising speed of the hook block 40 at the time of (four hooks) is shown.

  Here, when one hook (n = 1), there is only one wire rope 34 suspending the hook block 40, so the descending speed and ascending speed of the hook block 40 (solid line graph in FIG. 5) are This coincides with the feeding speed and hoisting speed of the wire rope 34 of the winch 28 (graph of FIG. 4). Further, when two hooks (n = 2), since there are two wire ropes 34 hanging the hook block 40, the lowering speed and the rising speed of the hook block 40 with respect to the boom head (the broken line in FIG. 5). (Graph) is half of the feeding speed and winding speed of the wire rope 34 of the winch 28 (graph of FIG. 4).

  Similarly, when there are three hooks (n = 3), since there are three wire ropes 34 hanging the hook block 40, the lowering speed and the rising speed of the hook block 40 with respect to the boom head (one point in FIG. 5). The broken line graph) is one third of the feeding speed and the winding speed (graph in FIG. 4) of the wire rope 34 of the winch 28. When four hooks (n = 4), the hook block 40 is suspended. Since there are four wire ropes 34, the descending speed and ascending speed of the hook block 40 with respect to the boom head (the two-dot chain line graph in FIG. 5) are the feeding speed and hoisting speed of the wire rope 34 of the winch 28. It becomes a quarter of (graph of FIG. 4).

  The cabin 15 is provided with a multiplier input device 35 in addition to the boom extension / contraction operation lever 30, the boom raising / lowering operation lever 31, the winch operation lever 32, and the drive control device 33 described above. The multiplier input device 35 is a device to which a multiplier n of the wire rope 34 hung on the hook block 40 is input. In the present embodiment, n = 2 in the state shown in FIG.

  The cabin 15 is provided with a multiplier input device 35 in addition to the boom extension / contraction operation lever 30, the boom raising / lowering operation lever 31, the winch operation lever 32, and the drive control device 33 described above. The multiplier input device 35 is a device to which a multiplier n of the wire rope 34 hung on the hook block 40 is input. The multiplication number n is the number n of wire ropes 34 that support the hook block 40. Therefore, n = 2 in the case shown in FIG.

  Note that the multiplier input device 35 can be configured by, for example, a touch panel type display device or a keypad in which numbers are arranged, which accepts an operation of inputting a multiplier n by an operator. The touch panel display device and the keypad are not limited as long as the value of the multiplier n can be input. In addition, these touch panel type display devices and keypads may be used as they are in the existing overload prevention device for the crane 100 as they are, or newly shared with dedicated products or other functions. It may be provided as a thing.

  The multiplier input device 35 is not input by an operator, but may be input by a sensor that detects a multiplier n. That is, the multiplier input device 35 is provided in the hook block 40 and inputs the number n of the wire ropes 34 hung on the hook block 40 by mechanically, electrically, optically or magnetically detecting the number n. It may be a sensor (multiplier detector). In this case, the operator does not need to manually input the multiplier n. On the other hand, when the multiplier input device 35 accepts an operation of inputting a multiplier n by an operator, it is not necessary to provide a sensor for detecting the multiplier n mechanically, electrically, optically or magnetically.

  Here, the drive control device 33 operates the operation in the extension direction in which the extension speed vb1 of the extendable boom 21 according to the operation amount in the extend direction input to the boom extend operation lever 30 is input to the winch operation lever 32. When the speed vf1 (= vw1 / n) of the limit value obtained by dividing the wire rope feeding speed vw1 according to the amount by the multiplier n input to the multiplier input device 35 is exceeded (vf1 <vb1) Controls the boom telescopic cylinder 26 so that the extension speed vb1 of the telescopic boom 21 becomes the limit value speed vf1 regardless of the operation amount input to the boom telescopic operation lever 30. This control can also be realized by controlling the electromagnetic proportional valve described above.

  Further, the drive control device 33 moves the hoisting speed when the retracting speed vb2 of the telescopic boom 21 according to the operation amount in the contracting (shortening) direction input to the boom telescopic operating lever 30 is input to the winch operating lever 32. The speed vf2 (= vw2 / n) of the second limit value obtained by dividing the winding speed vw2 of the wire rope according to the operation amount in the direction by the multiplier n input to the multiplier input device 35 When it exceeds the upper limit (vf2 <vb2), the boom telescopic cylinder 26 is moved so that the speed vb2 of contraction of the telescopic boom 21 becomes the speed vf2 of the second limit value regardless of the operation amount input to the boom telescopic operation lever 30. Control. This control can also be realized by controlling the electromagnetic proportional valve described above.

<Effect>
According to the boom expansion / contraction control device 50 configured as described above, when a multiplier n is input to the multiplier input device 35 by the operator, the value of the multiplier n input to the multiplier input device 35 is: Input to the drive control device 33.

  When the telescopic boom 21 is extended, the operator tilts the boom telescopic operation lever 30 forward. At this time, since the position of the boom head is increased, the operator makes the height position of the hook block 40 substantially constant. The winch operation lever 32 is also tilted forward so as to keep it. In order to perform the work quickly, the operator normally tilts both the boom telescopic operation lever 30 and the winch operation lever 32 forward to the maximum.

  Here, as understood from FIGS. 3 and 4, the maximum extension speed of the telescopic boom 21 corresponding to the maximum operation amount of the boom expansion / contraction operation lever 30 is the winch corresponding to the maximum operation amount of the winch operation lever 32. Slower than the maximum payout speed of 28. When the multiplication number n is 1, as is understood from FIGS. 3 and 5, the lowering speed of the hook block 40 is faster than the extension speed of the telescopic boom 21. The hook block 40 does not rise without controlling the extension speed of the corresponding telescopic boom.

  However, when the multiplier n is 2 or more, as is understood from FIGS. 3 and 5, the lowering speed of the hook block 40 due to the feeding of the wire rope 34 is slower than the extending speed of the telescopic boom 21. Therefore, when the drive control device 33 does not control the extension speed of the telescopic boom according to the multiplication number n, the hook block 40 will rise.

  On the other hand, in the boom extension / contraction control device 50 according to the present embodiment, the drive control device 33 inputs the extension speed vb1 of the extension / contraction boom 21 to the multiplier input device 35 so that the hook block 40 does not rise. The number is limited according to the multiplied number n. In other words, the drive control device 33 determines that the extension speed vb1 of the extendable boom 21 corresponding to the operation amount in the extension direction input to the boom extension operation lever 30 is the operation amount in the extension direction input to the winch operation lever 32. The speed vf1 (= vw1 / n: corresponding to the lowering speed of the hook block 40) of the limit value obtained by dividing the wire rope feeding speed vw1 corresponding to the value by the multiplier n input to the multiplier input device 35. When the value exceeds (vf1 <vb1), the boom telescopic cylinder 26 is controlled so that the expansion speed vb1 of the telescopic boom 21 becomes the limit value speed vf1 regardless of the operation amount input to the boom telescopic operation lever 30.

  As a result, even if the multiplication factor n of the wire rope 34 changes, the extension speed of the telescopic boom 21 is limited to the lowering speed of the hook block 40. Therefore, the movement of the hook block 40 ascending as the telescopic boom 21 extends. The minute is offset by the downward movement of the hook block 40 due to the length by which the wire rope 34 is fed. Therefore, the height position of the hook block 40 can be kept substantially constant. Further, the boom extension / contraction control device 50 according to the present embodiment adds a multiplier input device 35 for receiving an input of a multiplier n to the existing crane working unit 20, and the boom extension / contraction by the existing drive control device 33. This can be realized with a simple configuration in which the control for the cylinder 26 is changed.

  The extension speed vb1 of the telescopic boom 21 may be equal to or lower than the lowering speed vf1 of the hook block 40 with respect to the boom head (vb1 ≦ vf1) and coincides with the lowering speed vf1 of the hook block 40 (vb1 = vf1). It is not limited. That is, the extension speed vb1 of the telescopic boom 21 may be limited so as to be lower than the lowering speed vf1 of the hook block 40 (vb1 <vf1). In this case, although the height of the hook block 40 is reduced, the hook block 40 is prevented from approaching the boom head, and the so-called overwinding state can be prevented.

  The boom expansion / contraction control device 50 according to the present embodiment is an explanation in a situation where the amount of tilting (operating amount) of the boom telescopic operating lever 30 and the amount of tilting (operating amount) of the winch operating lever 32 are maximum. The operation amount of the boom telescopic operation lever 30 and the operation amount of the winch operation lever 32 are not limited to the maximum situations.

  Further, the boom extension / contraction control device 50 of the present embodiment can be applied to a case where the multiplier n is 1. That is, when the maximum extension speed of the telescopic boom 21 corresponding to the maximum operation amount of the boom expansion / contraction operation lever 30 is faster than the maximum extension speed of the winch 28 corresponding to the maximum operation amount of the winch operation lever 32. Even when the multiplication number n is 1, the drive control device 33 causes the winch operation lever 32 to generate the extension speed vb1 of the telescopic boom 21 according to the operation amount in the extension direction input to the boom telescopic operation lever 30. The speed vf1 (= vw1 / 1) of the limit value obtained by dividing the wire rope feeding speed vw1 corresponding to the input operation amount in the feeding direction by the multiplier n inputted to the multiplier input device 35. Therefore, regardless of the operation amount input to the boom telescopic operation lever 30, the extension speed vb1 of the telescopic boom 21 is set to be equal to or lower than the speed vf1 of the limit value. Controlling the cylinder 26.

  Further, the boom extension / contraction control device 50 according to this embodiment controls the reduction speed of the extension / contraction boom 21 so that the height position of the hook block 40 is substantially constant even when the extension / contraction boom 21 is reduced. That is, the drive control device 33 operates the operation in the hoisting direction in which the speed vb2 of the expansion / contraction boom 21 according to the operation amount in the contraction direction input to the boom expansion / contraction operation lever 30 is input to the winch operation lever 32. The wire rope hoisting speed vw2 corresponding to the amount exceeds the speed vf2 (= vw2 / n) of the second limit value obtained by dividing the winding speed vw2 by the multiplier n inputted to the multiplier input device 35 (vf2 <Vb2), the boom telescopic cylinder 26 is controlled so that the contracting speed vb2 of the telescopic boom 21 becomes the second limit value speed vf2 regardless of the operation amount input to the boom telescopic operating lever 30.

  As a result, even if the multiplication factor n of the wire rope 34 changes, the reduction speed of the telescopic boom 21 is limited to be higher than the ascent speed of the hook block 40, so that the hook block 40 descends as the telescopic boom 21 contracts. The amount of movement is offset by the amount of movement of the hook block 40 rising due to the length of the wire rope 34 being wound up. Therefore, the height position of the hook block 40 can be kept substantially constant.

  The boom extension / contraction control device 50 according to the present embodiment already includes a multiplier input device 35 that accepts an input of a multiplier n for the existing crane working unit 20. This can be realized with a simple configuration in which the control of the boom telescopic cylinder 26 by 33 is changed. Further, in the case of a crane that does not include a multiplier input device 35 such as a vehicle-mounted crane, a multiplier input device 35 is added, and the control for the boom telescopic cylinder 26 by the existing drive control device 33 is simply changed. It can be realized with a configuration.

  Note that the reduction speed vb2 of the telescopic boom 21 may be equal to or less than the rising speed vf2 of the hook block 40 with respect to the boom head (vb2 ≦ vf2), and coincides with the rising speed vf2 of the hook block 40 (vb2 = vf2). It is not limited. That is, the reduction speed vb2 of the telescopic boom 21 may be limited so as to be lower than the rising speed vf2 of the hook block 40 (vb2 <vf2). In this case, although the height of the hook block 40 is increased, it is possible to prevent the load suspended by the hook block 40 from coming into contact with the ground.

  The boom extension / contraction control device according to the present invention can be applied to a winch for operating a jib, a tilt winch or the like in addition to the extension boom. Specifically, when a jib is attached to the tip of the boom, the hook block is suspended through a sheave provided at the tip of the jib. Also in such a case, the boom block expands and contracts, so that the height of the hook block changes. Therefore, the boom expansion and contraction control according to the multiplication factor n can be applied. It can be similarly applied to a crane having a structure in which the jib itself expands and contracts.

  In addition, a structure in which a wire rope wound around a tilt winch is wound around when a luffing jib is mounted at the tip of the boom, as in an all terrain crane, is employed. In this case, when the boom is extended and contracted, the tilt winch also needs to be interlocked, and the present invention can be applied to the speed of expansion and contraction of the boom when the wire rope is extended and wound by the tilt winch. .

20 Crane Working Unit 21 Telescopic Boom 26 Boom Telescopic Cylinder 30 Boom Telescopic Operation Lever 32 Winch Operation Lever 33 Drive Control Device 34 Wire Rope 35 Multiply Input Device 40 Hook Block 50 Telescopic Control Device 100 Rough Terrain Crane n Multiply

Claims (3)

A multiplier input device for inputting the multiplier of the wire rope to the hook block;
With respect to the boom telescopic drive unit for extending and retracting the boom, control is performed so as to change the speed at which the boom is expanded and contracted according to the operation amount input to the boom telescopic operation unit to which the operation to expand and contract the boom is input. A speed at which the wire rope is fed out in accordance with an operation amount input to the winch operation unit in which an operation to feed out or wind up the wire rope is input to a winch driving unit that feeds and winds up the wire rope wound around the winch And a drive control device that controls to change the winding speed,
The drive control device may be configured such that the boom expansion / contraction speed according to the operation amount input to the boom expansion / contraction operation unit corresponds to the wire rope feeding speed according to the operation amount input to the winch operation unit, or the When the wire rope winding speed exceeds the speed of the limit value obtained by dividing by the multiplier input to the multiplier input device, regardless of the operation amount input to the boom telescopic operation section. A boom extension / contraction control device that controls the boom extension / contraction drive unit so that a boom extension / contraction speed is equal to or less than the limit value.   The boom expansion / contraction control device according to claim 1, wherein the multiplier input device receives an operation of inputting the multiplier by an operator.   The boom expansion / contraction control device according to claim 1, wherein the multiplier input device is a multiplier detector provided in the hook block for detecting the multiplier.