WO1996000694A1

WO1996000694A1 - Method of and apparatus for extending and storing boom

Info

Publication number: WO1996000694A1
Application number: PCT/JP1995/001271
Authority: WO
Inventors: Masayuki Mukaino; Keiichi Mokka; Masanori Ikari; Minoru Wada
Original assignee: Komatsu Ltd.; Komatsu Mec Kabushiki Kaisha
Priority date: 1994-06-28
Filing date: 1995-06-26
Publication date: 1996-01-11
Also published as: CN1151147A; JP3215577B2; KR100378584B1; JPH0812269A; EP0768274B1; TW355542U; DE69525842D1; EP0768274A1; EP0768274A4; DE69525842T2

Abstract

The invention relates to a method of and an apparatus for extending and storing a boom, which can be operated from a cab since a hook is positively engaged by a second boom to make a wire rope free of loosening and over-tightening. To that end, the apparatus comprises engagement means (34) for engaging the hook (22) on the second boom (20), low pressure relief valve means (54) for a driving hydraulic pressure for a hydraulic winch (50), means (73) for holding a low speed hoisting action of the winch (50), and a sheave (14) adapted to engage with a wire rope (23) which connects the winch (50) and the hook (22) to each other.

Description

Description Boom overhang, storage method and device

The present invention relates to a method and an apparatus for extending and storing a boom, and more particularly to a method for extending and storing a second boom of a crane truck in which a second boom is stored side by side on a side of the first boom. Related to the device. Background technology

The configuration and operation of a conventional crane truck will be described with reference to FIGS. 13 to 18 according to the present invention. In a conventional crane truck, as shown in FIGS. 13 and 14, the first boom 2 is mounted on the vehicle 1 so as to be able to move up and down. At the end of the first boom 2, a rotating bracket 10 is attached to rotate by a shaft 11 arranged in a direction substantially perpendicular to the ground. A second boom 20 is attached to the rotating bracket 10 by a pin 12 so as to be able to move up and down. FIGS. 13 and 14 show a state in which the second boom 20 is stored on the side surface of the first boom 2 and the outrigger 4 is stored in the vehicle body 1 so that the vehicle can run.

The hooks 5 and 22 provided on the second boom 20 and suspending the load are suspended by wire ropes 6 and 23 connected to a winch (not shown) mounted on the vehicle body 1. In the traveling state, the wire ropes 6 and 23 are wound by winches, and the hooks 5 and 22 are in a locked state.

Next, a procedure for extending the second boom 20 from the retracted state to a state in which the second boom 20 can be suspended will be described.

(1) As shown in Fig. 15, after extending the outrigger 4 and then extending the first boom cylinder 3 of the first boom 2 to stand up, the first boom 2 is moved about 1 m in the direction of the arrow. Shin: Yes. (2) After the extension, the second boom cylinder 21 is shortened and the second boom 20 is lowered as shown in FIG.

(3) Next, as shown in FIG. 17, the rotating bracket 10 is rotated about 180 ° about the axis 11 to obtain the longitudinal axis of the second boom 20 and the first boom 2. (Hereinafter, referred to as the overhang stroke).

(4) After matching, insert the connecting pin 18 at the position where the hole 9 provided on the other side of the first boom 2 matches the hole 17 provided on the other side of the rotating bracket 10 . The holes 9, 17 and connecting pins 18 in the stored state are shown in FIG.

(5) Next, as shown in FIG. 18, the second boom cylinder 21 is extended, and the second boom 20 is erected. As a result, the overhang work is completed, and the suspension work becomes possible.

However, in such a configuration, since the hook is locked by the winch hoisting in a state where the second boom is stored in parallel with the first boom, the wire rope is hung in the middle of the upright stroke and the overhang stroke. May be loose or too tight. For example, in the overhang process shown in FIG. 16, the wire rope sags, and the hooks 5 and 22 hang down as shown in FIG. Therefore, at positions J and K, interference occurs, and at positions L and M, the wire ropes 6 and 23 are excessively bent, resulting in kink. Further, in the section N, there is a problem that the wire rope 6 is twisted or irregularly wound. Furthermore, when the first boom 2 is extended in the hook storage state as shown in Fig. 15, excessive tension is generated in the wire rope, and the wire rope may be cut, and boom structural parts, sheaves, etc. There is a problem of damage.

Therefore, in order to avoid the above-mentioned problem, conventionally, the operator detaches the hooks 5, 22 and the wire ropes 6, 23 from the second boom 20, and after performing a series of overhanging work, the operator The wire ropes 6, 23 were reset, and the hooks 5, 22 were engaged with the wire ropes 6, 23, respectively, so that the hanging work was possible.

However, in this case, the operator gets off the driver's seat and uses a stepladder or the like. Dangerous work and difficult work such as setting up the wire ropes 6 and 23 on the second boom 20 and the first boom 2 by climbing above each boom are required. Therefore, there was a need for a method and apparatus capable of performing all operations in the cab. Disclosure of the invention

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and hooks a hook to a second boom without causing loosening or excessive tension on a wire rope during a boom overhang or a storage operation. It is an object of the present invention to provide a method and an apparatus for extending and storing the boom which can perform the operation of extending and storing the second boom in the state where the second boom is extended.

A method of projecting and storing a boom according to the present invention includes a first boom that includes a hook for lifting a load, and a hydraulic drive winch for hoisting and unwinding the hook, and is mounted so as to be able to move up and down and expand and contract in multiple stages. The second boom is attached to the tip of the crane truck so that it can be raised and lowered, and the second boom is stored in parallel on the side of the first boom. The hook is always engaged with the second boom by maintaining the hydraulically driven winch at a low torque for an appropriate torque and at a low speed for a proper speed. According to such a configuration, the hook is securely locked to the second boom by the hydraulically driven winch, so that the operator can extend and store the boom in the cab. Also, since there is no looseness of the wire rope, interference between the hook and other members can be prevented, and since the tension of the wire rope is appropriate, breakage of the boom structure parts, the wire rope, and the like can be prevented.

A boom overhang and storage device according to the present invention includes a load-hook hook, and a hydraulic drive winch for hoisting and unwinding the hook, and a first boom that is mounted so as to be able to move up and down and expand and contract in multiple stages. The second boom is attached to the end of the crane truck so that it can be raised and lowered, and the second boom is stored in parallel on the side of the first boom. Locking means for locking to the hydraulic drive Low-pressure relief means for driving the hydraulic drive winch, maintenance means for maintaining the low-speed hoisting operation of the hydraulic drive winch, and mounted horizontally on the second boom to connect the hydraulic drive winch to the hook And a shim engaged with the wire rope. Also, a hook storage switch and a control device are provided, and when the hook storage switch is operated, the control device is provided with a hydraulic motor for lifting the hook of the hydraulically driven winch when the lifting load is a predetermined amount or more. A command to maintain the pressure at a high pressure or a non-excitation command for the operation of the hook storage switch may be output. In addition, there may be more than one hook.

With this configuration, the same operation and effect as the above-described method can be obtained. In addition, the wire rope at the time of storage is bent in a U-shape by the sieve mounted horizontally, so that the hook and the winch are easily connected by the wire rope. Moreover, since the hook is locked to the second boom, the rope is maintained in an appropriate tension state and does not become loose. In addition, since the control device outputs a command corresponding to the lifting load, if the hook is not in a state where the hook can be stored, the hydraulic drive winch does not perform the winding operation even if the hook storage switch is turned on. , Be safe. In addition, when installing multiple hooks that can be locked to the boom at all times, for example, when installing two hooks on the second boom, or one each on the first and second booms, Spread

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of a hook mounting portion at the tip of a second boom according to the embodiment of the present invention, FIG. 2 is a side view of another hook mounting portion near the tip of the second boom according to the embodiment, and FIG. FIG. 9 is a plan view of a connection portion between the first boom and the rotating bracket in the second boom storage state according to the embodiment;

FIG. 4 is a plan view of a main part of the second boom overhang state according to the embodiment.

Fig. 5 is a hydraulic circuit diagram of the first embodiment of the boom and hook drive winch operation system according to the embodiment,

Fig. 6 is a block diagram of the interlock device in the first embodiment of the winch operation system. FIG. 7 is a flowchart of the overhang work in the first embodiment of the winch operation system, and FIG. 8 is a flowchart of the operation of the interlock device in the first embodiment of the winch operation system.

FIG. 9 is a hydraulic circuit diagram of a main part of a second embodiment of the boom and hook drive winch operation system according to the embodiment,

FIG. 10 is a hydraulic circuit diagram of a main part of a third embodiment of the boom and hook drive winch operation system according to the embodiment,

FIG. 11 is a side view showing a crane truck to which the present invention is applied, wherein a hook is attached to the first and second booms and the second boom is in a retracted posture,

Fig. 12 is a side view showing the posture of the crane vehicle shown in Fig. 11 in the process of extending the second boom, and Fig. 13 is a side view of the crane vehicle according to the embodiment of the present invention having a plurality of hooks mounted on the second boom. ,

Figure 14 is a plan view of the crane vehicle in Figure 13;

FIGS. 15 to 18 are diagrams for explaining the process of extending the second boom of the crane vehicle shown in FIG. 13 during the process of extending the second boom. FIG. 15 is a side view of the first process, and FIG. Fig. 17 is a side view of the third stroke, Fig. 18 is a side view of the fourth stroke,

FIG. 19 is an explanatory view of a defect of a hook for a crane truck according to the related art. BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the method and apparatus for extending and storing a boom according to the present invention will be described in detail below with reference to the accompanying drawings.

The present embodiment is an example in which the present invention is applied to the crane truck shown in FIGS. 13 and 14. In FIG. 1, a sheave bracket 24 is fixed to the tip of the second boom 20, and two sheaves 25 and 26 are attached. A bracket 30 is attached to the tip of the sheave bracket 24 so as to be swingable by a pin 31, and a hook 22 is provided on the lower surface 32 of the bracket 30. Hook 2 2 and hydraulic drive The wire 50 (see FIG. 5) is connected to the wire 50 through wires 25 and 26 by a wire rope 23.

When the hydraulic drive winch 50 (hereinafter referred to as winch 50) is operated and the wire port 23 is pulled in the direction of arrow A, the hook 22 and the bracket 30 are united. Rotate in the direction of arrow B around pin 31. Then, at the position shown by the thin line, the stopper 33 provided on the bracket 30 comes into contact with the stopper 27 provided on the sheave bracket 24 and is locked. That is, the stoppers 27 and 33 constitute the hooking means 34 of the hook 22.

In FIG. 2, a sheave 35 is attached to a side surface of the second boom 20 by a sheave bracket 36, and a sheave 37 is attached to a lower surface of the second boom 20 by a sheave bracket 38. ing. A bracket 40 is attached to the tip of the sheave bracket 38 so as to be swingable by a pin 41, and a hook 5 is provided on a lower surface 42 of the bracket 40. The sheave 46 and the winch 50 (see FIG. 5) of the hook 5 are connected by a wire rope 6 via sheaves 35 and 37, and the end of the wire rope 6 is connected to the second boom 20. It is connected to the bracket 43 provided on the lower surface.

When the winch 50 is actuated and the wire rope 6 is pulled in the direction of arrow C, the hook 5 and the bracket 40 are integrally rotated about the pin 41 in the direction of arrow D. I do. Then, at the position shown by the thin line, the stopper 44 provided on the bracket 40 comes into contact with the stopper 45 provided on the sheave bracket 38, and is brought into a locked state. That is, the ribs 44, 45 force <, which constitute the hooking means 47 of the hook 5.

In FIG. 3, brackets 7 and 8 are fixed on the left and right at the end of the end boom 2 a of the first boom 2, and one side of the rotating bracket 10 is attached to one side of the bracket 8 on one side of the shaft 11. It is mounted so that it can rotate freely. A rotating cylinder 13 is rotatably attached to the rotating bracket 10 with a pin 13a, and a lever 13b is attached to the piston rod at the other end of the rotating cylinder 13. Are arranged. The lever 13b is rotatably attached to a pin 13c fixed to the rotating bracket 10 and one end of the screw 13b. A ton rod has a link 13d rotatably attached to the other end. The link 13d is rotatably attached to the tip boom 2a via a pin 13e. The rotating bracket 10 is configured such that a rotating force is applied to the pin 13 a with respect to the pin 13 e by the expansion and contraction of the rotating cylinder 13, and the rotating bracket 10 rotates about the shaft 11. That is, the rotating bracket 10 rotates in the direction of arrow E when the rotating cylinder 13 is extended, and rotates in the direction of arrow E 'when the rotating cylinder 13 contracts. The pin 13c of the present embodiment matches the axis of a sheave 14 described later.

A second boom 20 is attached to the tip of the rotating bracket 10 so as to be swingable (vertically in the drawing) by a pin 12. On the upper surface of one side of the rotating bracket 10, a sheave 14 is mounted horizontally with the second boom 20. The sheave 14 has a wire rope 2 connecting the hook 22 and the winch 50. 3 are engaged. That is, the sheave 14 is disposed on the upper surface of one side of the rotating bracket 10 so that the rotation direction E of the rotating bracket 10 and the groove engaged with the wire rope 23 are parallel. I have. The sheave 15 and sheave 16 are mounted on the top surface of the top end of the first boom 2 and the other top surface of the rotating bracket 10 in the same manner as sheaves 15 and 16 and sheaves 15 and 16. A rope 6 connecting the hook 5 and the winch 50 is engaged.

With this configuration, when the rotary cylinder 13 is extended, the rotary bracket 10 rotates about the axis 11 in the direction of the arrow E, and comes to the position indicated by the two-dot chain line. When the rotating cylinder 13 is further extended, the rotating bracket 10 reaches the position indicated by the solid line through the position indicated by the two-dot chain line as shown in FIG. In this state, the hole 9 provided on the bracket 7 on the other side of the first boom 2 matches the hole 17 provided on the other side of the rotating bracket 10. In this aligned state, the connecting pin 18 is inserted, and the first boom 2 and the rotating bracket 10 are fixed at the extended position.

Next, a first embodiment of the boom and hook drive winch operation system according to the present embodiment will be described.

FIG. 5 is a hydraulic circuit diagram showing only a winch operation system for the hook 22 of the second boom 20 and an operation system for extending and retracting the boom. Winch operation system for hook 5 Are omitted because they are the same as the winch operation system for hook 22. The winch 50 includes a drum 51, a hydraulic motor 52, and a hoist circuit 53. 60 is a pilot valve for operation, 61 is a winch operation valve, 62 is a boom extension / retraction operation valve, and 63 is a pilot pump. The pilot circuit of the winch switching valve 64 is connected to the winch operating valve 61, and the pilot circuit of the boom telescopic cylinder switching valve 65 is connected to the boom telescopic operating valve 62. .

The discharge side of the hydraulic pump 66 is connected to a boom telescopic cylinder 67 and a hydraulic motor 52 through a boom telescopic cylinder switching valve 65 and a winch switching valve 64, respectively. Reference numeral 68 denotes a high-pressure hydraulic relief valve, and reference numeral 69 denotes a pressure compensating valve. An electromagnetic switching valve 55 and a low-pressure leaf valve (low-pressure relief means) 54 are interposed in the drain circuit 56 connected to the winding circuit 53 of the wire rope 23 of the hydraulic motor 52. .

An electromagnetic proportional valve (maintenance means) is provided in a circuit 72 that connects the hoist-side pilot circuit 70 of the directional control valve 64 and the pilot pump 63 through a shuttle valve 71. 3 are interposed. The hoist circuit 53 is provided with a counter balance valve 57. The electromagnetic switching valve 55 and the electromagnetic proportional valve 73 are connected to a later-described control device 80 (see FIG. 6) by wiring (not shown).

Fig. 6 shows the configuration of an interlock device for ensuring the safety of the operation system. The control device 80 includes a traveling switch 81 provided in the driver's seat, a hook storage switch 82 and Connected to work switch 83. Further, the pressure sensor 84, the boom length sensor 85, and the boom angle sensor 86 of the first boom hoisting cylinder are connected to the control device 80, from which the suspension load is calculated.

Also, a connecting pin 18 for connecting the rotating bracket 10 to the other bracket 7 of the first boom 2, that is, a hole 17 on the other side of the rotating bracket 10 and a hole 9 of the bracket 7. A position detection sensor 87 for detecting insertion is provided on the connecting pin 18 to be inserted when the values match. This position detection sensor 87 is connected to the control device 80. The control device 80 receives signals from each switch and each sensor, and A control signal is issued to the electromagnetic switching valve 55, which opens and closes the circuit of the low-pressure relief valve 54 (see Fig. 5), and the electromagnetic proportional valve 73.

A method of extending the second boom in the first embodiment of the pinch operation system will be described with reference to a flowchart shown in FIG. It is assumed that the vehicle is initially in a running state in which the second boom 20 is stored, as shown in FIG.

(1) In step 101, the operator sets the work switch 83 to ON, and operates the outlet gas switch to extend the key trigger 4.

(2) In step 102, the operator sets the hook storage switch 82 to ON. The control device 80 issues a control signal, switches the electromagnetic switching valve 55 shown in Fig. 5 to the position 55b, and operates the low-pressure relief valve 54 to act on the winding circuit 53 of the hydraulic motor 52. Reduce hydraulic pressure to low pressure Pa. At the same time, the solenoid proportional valve 73 is operated to control the pilot pressure, and the winch switching valve 64 is controlled to the winding position 64b. When switched to the winding position 64 b, the pressure acting on the position a of the pressure compensation valve 69 via the throttle 58 in the switching valve 64 becomes the pressure Pa by the low-pressure relief valve 54. Become. The oil from the hydraulic pump 66 is throttled by the throttle 58 to a predetermined high pressure Pa + ΔP, and acts on the position b of the pressure compensating valve 69 via the pilot pipe 59. As a result, the spring force tries to balance the pressure difference ΔP (differential pressure of the throttle 58) between the pressure P a + m P acting on the position b and the pressure Pa acting on the position a. Therefore, the pressure compensating valve 69 tries to move in the direction of the position 69a. For this reason, the distribution flow rate of oil from the hydraulic pump 66 to the winding circuit 53 is determined according to the opening area of the throttle 58. As a result, a low hoisting pressure always acts on the hydraulic motor 52 that drives the winch 50. In addition, a constant low flow rate is supplied to the hoist circuit 53. With the hook 22 locked to the second boom 20, the wire rope 23 always maintains a constant tension. That is, the winch 50 always maintains a low torque and low speed hoisting operation.

(3) In step 103, the operator operates the boom raising / lowering lever (not shown) to raise the first boom 2 as shown in FIG. (Not shown) to extend the first boom 2 about 1 m in the direction of the arrow.

(4) In step 104, after the extension, the operator moves the second bump cylinder 2

1 is shortened and the second boom 20 is lowered as shown in FIG.

(5) In step 105, the operator sets the boom extension and the storage switch to the extension ON. The second boom 20 is rotated about the shaft 11 in the direction of arrow E by extension of the rotary cylinder 13, that is, as shown in FIG.

10 turns about 180 ° and overhangs.

(6) In step 106, the operator inserts the connecting pin 18 to connect the first boom 2 to the rotating bracket 10.

(7) In step 107, the operator operates the boom hoist lever to raise the second boom 20 as shown in FIG.

(8) In step 108, the operator turns off the hook storage switch 82, cancels the low-torque, low-speed winding of the winch 50, and completes the overhanging operation. Medium and always, the winch 50 is in a state of low pressure and low speed winding. As a result, the wire ropes 23 are always properly tensioned during the above-described steps, for example, when the second boom 20 is extended as shown in FIGS. 3 and 4, so that the wire ropes 23 are not loosened, and kinks and kinks do not occur. There is no risk of winding. Therefore, the boom can be extended and retracted while the hook 22 is locked to the second boom 20, and the pressure is low and the speed is low. That is, even if an excessive tensile force acts on the wire rope 23, the oil is relieved from the low-pressure relief valve 54, and the wire rope 23 is unwound, so that the wire rope 23 may be broken. There is no risk of bracket damage. Moreover, the operator can easily perform the operation of extending and storing the second boom 20 in the driver's seat.

Next, the operation of the interlock in the winch operation system will be described with reference to the flowchart of FIG.

(1) In step 200, the operator turns on the hook storage switch 82 (2) In step 201, the controller 80 calculates the suspension load based on signals from the pressure sensor 84, the boom length sensor 85, and the boom angle sensor 86, and determines whether the suspension load is equal to or greater than a predetermined amount. Determine whether or not. If the amount is more than the predetermined amount, it is determined that the lifting operation is in progress, and the process proceeds to step 204 to send a high pressure command to the winch 50 or to the hook storage switch 82. To send a non-excitation command.

(3) If the hanging load is smaller than the predetermined amount, it is determined that the hook can be stored, and the process proceeds to step 202, where the control device 80 receives the signal from the position detection sensor 87 provided on the connecting pin 18. Based on the signal, it is determined whether or not the connecting pin 18 for connecting the first boom 2 and the second boom 20 is inserted. If the connecting pin 18 is not inserted, it is determined that the second boom can be stored, and the process proceeds to step 205, where the control device 80 issues a low torque, low speed rewind command to the winch 50. I do.

(4) If the connecting pin 18 is inserted, it is determined that the lifting operation is in progress, and the process proceeds to step 203.The controller 80 determines whether the boom length is equal to or greater than the predetermined amount based on a signal from the boom length sensor 85. Determine whether or not. If the boom length is equal to or longer than the predetermined amount, it is determined that the lifting operation is being performed, and the process proceeds to step 204.

(5) If the boom length is smaller than the predetermined amount, it is determined that the hook can be stored, and the process proceeds to step 205.

As described above, the winch 50 does not perform the hoisting operation during the lifting operation due to the operation of the interlock of the present embodiment, so that the safety of the second boom extension operation is ensured. Although the same operation is exerted in the storage operation of the second boom 20, the description is omitted.

Next, a description will be given of a second embodiment of the boom and hook drive winch operation system according to the present embodiment.

FIG. 9 shows a main part of the hydraulic circuit of the present embodiment, and shows only parts different from FIG. That is, the electromagnetic switching valve 55 and the electromagnetic proportional relief valve 90 are interposed in the drain circuit 56 connected to the hydraulic motor 52, and the electromagnetic switching valve 55 is connected as described above. Connected to controller 80. Further, the boom extending and contracting operation valves 6 2 pilot Tobarubu 6 0, the extension-side P, circuits, interposed pressure sweep rate Tutsi 9 1, the circuits of the compression-side P _2, through the pressure sweep rate Tutsi 9 2 The pressure switches 91 and 92 are connected to a control device 80.

The operation of this configuration will be described. When the hook storage switch 82 is set to 0 N, the control device 80 issues a control signal to switch the solenoid-operated directional control valve 55 and to switch the solenoid-operated directional control valve 55 from the pressure switch 91 or 92. Receive a signal. Then, the electromagnetic proportional relief valve 90 is controlled by the expansion and contraction operation of the boom to control the pressure of the winding circuit 53 of the hydraulic motor 52. That is, when the boom is extended, the solenoid directional control valve 90 is set to a low pressure, and the 巻き inch 50 is rewinded at a low torque, and the hook 22 is moved to the second boom 2 with the extension of the boom. The wire rope 23 is allowed to be unwound from the winch 50 while being locked at zero. On the other hand, when the boom is shortened, the wire rope 23 is bent by lowering the pressure of the electromagnetic switching valve 90 and operating the electromagnetic proportional valve 73 to bring the hydraulically driven winch 50 into a low-speed winding state. And always nervous properly.

Next, a description will be given of a third embodiment of the boom and hook drive winch operation system according to the present embodiment.

FIG. 10 shows a main part of the hydraulic circuit of this embodiment, and shows only parts different from FIG. That is, the electromagnetic proportional valve 93 is interposed on a circuit connecting the pump circuit P and the tank circuit T of the boom expansion / contraction operation valve 62. The electromagnetic proportional valve 93 controls the supply pressure of the pilot circuit to the boom expansion / contraction operation valve 62 to limit the expansion / contraction speed of the boom. As a result, when the boom is extended, no excessive force is applied to the tensioned wire rope 23, and when the boom is shortened, the bending phenomenon in which the winding speed of the winch 50 is not enough for the boom shortening speed is achieved. Preventing.

The embodiments of the method and apparatus for extending and storing the boom according to the present invention have been described in detail, but the present invention is not limited to the above embodiments. First, the hook 5 attached to the second boom 20 has the same function and effect as the above-described embodiment by the same configuration. can get. Further, as for the plurality of hook mounting positions, for example, as shown in FIGS. 11 and 12, the hook 5 may be mounted on the first boom and the hook 22 may be mounted on the second boom 20. Industrial applicability

According to the present invention, when the second boom is extended and retracted, the hook is securely locked to the second boom, and the wire rope is not loosened or overstretched. It is useful as a method and a device for extending and storing a boom that can prevent the generation of kink and random winding of a wire rope.

Claims

The scope of the claims

1. Equipped with a hook for loading and a hydraulically driven winch for hoisting and unwinding the hook, the second boom is raised and lowered at the tip of the first boom, which is mounted to be able to move up and down and expands and contracts in multiple steps. The crane vehicle boom overhanging and retracting method in which the second boom is freely mounted and the second boom is stored in parallel on a side surface of the first boom,

When the second boom (20) is extended and retracted, the hydraulic drive winch (50) maintains a low-torque and low-speed hoisting operation, so that the hook (22) is always in contact with the second boom (20). A method for extending and storing the boom, which is characterized in that it is locked to the boom (20).

2. Equipped with a lifting hook and a hydraulically driven winch for hoisting and unwinding the hook, the second boom can be freely raised and lowered at the tip of the first boom, which is mounted to be able to move up and down and expands and contracts in multiple stages. A crane vehicle boom that is mounted on a side of the first boom so that the second boom is stored in parallel on a side surface of the first boom, wherein the hook (22) is attached to the second boom (20). ), A low-pressure relief means (54) for driving hydraulic pressure of the hydraulic drive winch (50), and maintaining the low-speed hoisting operation of the hydraulic drive winch (50). Means (73), which is horizontally mounted on the second boom (20) and engages with a wire port (23) connecting the hydraulic drive winch (50) and the hook (22). Boom overhang and storage device, comprising

3. A hook storage switch (82) and a control device (80) are provided, and when the hook storage switch (82) is operated, the control device (80) operates when the hanging load is a predetermined amount or more. And outputting a command to maintain the pressure of the hook winding hydraulic motor (52) of the hydraulic drive winch (50) at a high pressure, or a non-excitation command for operating the hook storage switch (82). The boom overhang and storage device according to claim 2.

4. The boom overhang and storage device according to claim 2 or 3, wherein the hooks (22) are plural (22, 5).