JPH07115836B2 - Crane storage control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a crane used for lifting a heavy object, and in particular, a crane capable of storing and storing a hook receiver hung by a wire with high precision. Storage control method.

[Conventional technology]

Conventionally, a crane has been often used to lift a heavy object. In this case, in the fixed boom crane in which the boom does not expand and contract, the hook receiver and the hook take-in are extremely simple, and the hook receiver is hooked and fixed to a part of the vehicle body. It was also possible to pull up the hook receiver to the tip of the boom and fix it to the tip of the boom without overwinding.

However, in order to expand the range of lifting and moving heavy objects, the boom itself must be expanded or contracted in two or three steps,
A crane having a mechanism for suspending a wire from the end of the expanded and contracted boom is used. In the crane of this structure, the storage of the hook receiver when storing the boom has become a problem. That is, when the hook receiver is stored, the boom extension and contraction and the wire movement must be synchronized. In the past, this control was usually done manually by the operator's intuition, but if the wire is wound up quickly or the boom stretches quickly, the wire will be overwound. In some cases, the hook receiver collided with the tip of the boom, causing a malfunction.

Also, if the crane is protruding to the outside like a truck with a crane, this is not a big problem, but in a mechanism where the crane itself is stored or stored in a part of the vehicle body, the hook receiver is If it is exposed from a part of the car, the hook receiver sways when the car body moves, which is very dangerous.

[Problems to be solved by the invention]

As described above, in the past, when fixing the hook receiver to the tip of the boom, the worker either fixes the hook receiver to the hook holder or hooks the hook holder on a part of the body of the truck and then attach the wire. There are many methods of temporarily fixing the boom and the wire by hoisting them, both of which are performed manually by a worker, not automatically. Therefore, fix the hook receiver to the tip of the expanding and contracting multi-stage boom,
There was a desire for an automated method.

[Means for solving problems]

The present invention relates to a crane including a boom that expands and contracts, a wire that is hung from the tip of the boom and is wound and unwound by a winding mechanism, and a hook receiver that is hung below the wire. When storing, the crane is characterized by holding the hook receiver on the boom at the tip by hoisting the wire and holding the hook receiver so that it does not fall from the tip of the boom by synchronizing the winding of the wire and the expansion and contraction of the boom. A control method is provided.

[Action]

The boom of the present invention expands and contracts in multiple stages, and the wire is suspended from the boom at the end of expansion and contraction. Since the hook receiver is connected to the tip of this wire, the hook receiver can be moved up and down by winding up and rewinding the wire. Then, when the lifting operation is completed and the hook receiver is stored in the boom, the wire is rolled up to hold the hook receiver itself at the tip of the boom, and then the operation of the boom and the wire are synchronized, and the hook receiver is The length of the entire boom can be reduced while keeping it from falling from the tip of.

Therefore, when retracting the hook receiver when the boom is contracted, it is not necessary to manually perform the two operations of winding the wire and expanding and contracting the boom, and the worker automatically attaches the hook receiver to the tip of the boom without resorting to intuition. Can be fixed and stored in. Also, since the hook receiver is held at the tip of the boom, the hook receiver does not swing from the tip of the boom due to movement or vibration of the vehicle body, and the hook receiver does not collide with workers or other structures. The safety is ensured when moving.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In the present embodiment, an excavator with a crane will be described in which a retractable crane mechanism is attached to the inside of the excavator, and the crane mechanism is stored inside the boom when a heavy load is not lifted.

A front wheel 2 and a rear wheel 3 are axially supported on the front, rear, left, and right of the vehicle body 1, and an annular crawler 4 is wound between the front wheel 2 and the rear wheel 3. At the top of this car body 1,
A swivel base 5 capable of swiveling in 360 degrees is placed on the front of the swivel base 5, and a boom 6 bent in a slightly V shape is pivotally supported vertically in the center of the front surface of the swivel base 5. . Two hydraulic cylinders 7 are interposed between the swivel base 5 and the left and right sides of the boom 6 at a slightly intermediate position, and the boom 6 can be vertically restrained by the hydraulic cylinders 7. An arm 8 is connected to the tip of the boom 6, and a bucket 9 is connected to the tip of the arm 8.
A hydraulic cylinder 10 is provided between the boom 6 and the arm 8.
And a hydraulic cylinder 11 is also interposed between the arm 8 and the bucket 9. A cabin 12 in which a driver's vehicle appears is fixed on the upper side of the swivel base 5 on the front side, and a drive mechanism 13 accommodating an engine and the like is mounted on the rear part of the swivel base 5. is there. These structures are the same as those of well-known excavators.

A crane mechanism 15 is housed inside the linear portion on the tip side of the boom 6 bent into the dogleg shape. The crane mechanism 15 has a hydraulic cylinder therein, and can be expanded and contracted in three stages as a whole, and has a conventionally known structure.

This crane mechanism 15 is a former boom 16 fixed to the boom 6.
It is composed of a middle boom 17 housed inside the former boom 16 so that it can move back and forth, and a front boom 18 inserted inside the middle boom 17 so that it can move forward and backward. is there. The length of the original boom 16 is substantially equal to the length from the center of the boom 6 to the tip thereof, and the opening of the tip of the original boom 16 is located near the connecting point between the boom 6 and the arm 8. And at the tip of the tip boom 18, wire
A head 19 that houses a pulley etc. for inverting 20 is fixed, and a wire hanging from this head 19
A hook receiver 21 is hung on the 20.
A hook 22 is fixed to the lower end of 21. Also, boom 6
A winding machine 25 is fixed to the center on the back side of the winding machine, and one end of the wire 20 is wound around a winding drum 26 of the winding machine 25. Then, the wire 20 extends in the direction of the head 19 and turns inside the head 19 toward the hook receiver 21.

Next, FIG. 6 is an enlarged view of the vicinity of the head 19 and the hook receiver 21.

The hook receiver 21 is formed by bending a steel plate into a U-shape, and the U-shaped lower end opening faces downward, so that the shaft support plates 30 and 31 on both sides are vertical. It is located. Pulleys 32 and 33 are inserted between the shaft support plates 30 and 31, respectively.
The shaft 33 is rotatably supported by a shaft 34 held by shaft support plates 30 and 31. Further, a U-shaped inverted body 35 is connected to the outside of the shaft support plates 30 and 31, and the inverted body 35 is pivotally supported by the shaft support plates 30 and 31 by a shaft 36. This axis 36
Is slightly offset from the shaft 34 toward the boom 18 side. Further, on both sides of the shaft support plates 30 and 31, above the shaft 34, there is a limit switch 37 that comes into contact with the reversing body 35.
Are fixed by protruding to the left and right.

A pulley 38 is pivotally supported inside the hook receiver 21. The above-mentioned wire 20 is pulled out from the winding drum 26, first inverted downward by the pulley 32, and then inverted upward by the pulley 38 in the hook receiver 21. Next, the wire 20 directed upward is turned upside down by the pulley 33, and the tip of the wire 20 is connected to the upper part of the hook receiver 21.

Next, a slightly wedge-shaped actuation body 40 is fixed to the side surface of the tip end of the middle boom 17. A limit switch 41 is fixed to the side surface of the front end of the original boom 16, and the limit switch 41 can be operated in contact with the actuation body 40. The middle boom 17 is located slightly in the center of the middle boom 17.
A limit switch 42 that moves together with the inner wall surface of the original boom 16 is attached. This limit switch
42 is operated at the tip end position of the original boom 16, and the position where this limit switch 42 operates is such that the head 19 is exposed to the outside and the wire receiver 21 may be lowered as shown in FIG. It has been set to the position. A limit switch 43 is also attached to the tip of the boom 6, and the limit switch 43 is operated by contacting a part of the arm 8.
When is operated, the arm 8 is bent to the innermost position by the hydraulic cylinder 10.

Next, FIG. 7 shows an arm lock mechanism. This arm lock mechanism fixes the boom 6 and the arm 8, and when the crane mechanism 15 is performing the hoisting operation, the arm 8 does not rotate and is always engaged with the boom 6 to maintain a safe state. It is a mechanism for.

A pair of holding plates 44, 45 are fixed to the inner lower surface of the boom 6 at intervals, and pin holes 46, 47 are formed in the centers of the holding plates 44, 45, respectively. Further, a slightly fin-shaped fixing plate 48 is fixed to the lower surface of the arm 8, and a pin hole 49 is also opened at the tip of this fixing plate 48. The fixing plate 48 moves with the rotation of the arm 8 to move the holding plates 44, 45.
It can be inserted between. Also, the pin hole
A fixing pin 50 which is slidably movable in both pin holes 46 and 47 is inserted into each of 46 and 47, and a rear portion of the fixing pin 50 is connected to an angle 51 bent into an L shape. This angle
The center of 51 is rotatably supported by a pin 52, and a rod 54 of an arm lock hydraulic cylinder 53 is connected to the other end of the angle 51. This angle 51 movement causes pin 50
Moves and is inserted through the pin holes 46, 47, 49, and the holding plates 44, 45
And the fixing plate 48 can be connected. Further, a limit switch 55 is attached to the side surface of the holding plate 44, and the limit switch 55 is operated by contacting the tip of the fixed pin 50.

Next, FIG. 8 shows a hydraulic circuit in this embodiment.

The hydraulic pump 60 operated by the engine 61 has its suction side connected to the oil tank 62, and the output side of the hydraulic pump 60 is connected to the solenoid valve 63. This solenoid valve switches in two directions and is usually connected to the hydraulic cylinders 7, 10, 11 of the excavator and the hydraulic motor for operating the crawlers.

This solenoid valve 63 is connected to a three-way switching type solenoid valve 64, and one output of the solenoid valve 64 is a manual switching valve 65 for moving the wire 20 up and down and a manual switching valve 65 for extending and retracting the boom. The switching valves 66 are connected in parallel. The other output of the solenoid valve 64 is connected to solenoid valves 70, 71, 72 via pressure reducing valves 67, 68, 69, respectively. The output of the switching valve 65 is connected to the hydraulic motor 59 that rotates the take-up drum 26, and the output of the switching valve 66 is housed inside the original boom 16 (not shown). It is connected to a hydraulic cylinder 73 for extending and retracting the tip boom 18. And the switching valve 65,
An oil passage for return oil is connected to 66, and this oil passage for return oil communicates with the oil tank 62. At the same time, a return oil passage is connected to each of the solenoid valves 64, 70, 71, 72, and this return oil passage is communicated with the oil tank 62.

A hydraulic cylinder 53 for arm locking is connected to the solenoid valve 72. Throttle valves 74 and 75 are connected to the output side of the solenoid valve 70, and are connected to the hydraulic motor 59 via the throttle valves 74 and 75. These throttle valves 74,
Check valves 76 and 77 are connected in parallel to both ends of 75, respectively. Further, throttle valves 78 and 79 are connected to the solenoid valve 71, respectively, and the hydraulic cylinder is connected through the throttle valves 78 and 79.
73 is connected. Check valves 80 and 81 are connected in parallel to both ends of the throttle valves 78 and 79, respectively. The throttle valves 74, 75, 78, 79 respectively control the flow rate of oil, and their set values will be described later.

Next, FIG. 9 shows an electric circuit diagram of the control system in this embodiment.

Relays 86, 87, 88 and 89 are connected in series to the limit switches 37, 41, 42 and 43, respectively. Then, the contact 90 operated by the relay 88 has a relay 85
Are connected in series. A coil 63A is connected in series to a contact 91 operated by the relay 87,
Coil 64 is included in the normally closed contact 92, which is actuated by relay 85.
A is connected, and a coil 64B is connected in series to a contact 93 which is operated by the relay 85 at the same time.
The switch 94 is of a switching type, and switches the operation of the crane mechanism between pushing and pulling. On the push side of this switch 94, a contact 95 operated by a relay 87
The limit switch 55 and the coil 71A are connected in series. Further, a contact 97 operated by the relay 86 and a coil 71B are connected in series to the contact on the retracting side of the switch 94. The switch 98 is operated in conjunction with the switch 94 described above, and the contact on the pushing side of the switch 98 is a contact 99 that is operated by the relay 86 and the coil 70A.
Are connected in series. Also, on the retracting side of the switch 98, a normally closed contact 100 operated by a relay 89 and a coil 70B.
Are connected in series. Next, the switch 101 is a switching type, and this switch 101 is for switching the arm lock, and a contact 102 operated by a relay 87 and a coil 72A are connected in series to the contact on the lock entering side. .
Further, a contact 103 operated by a relay 89 and a coil 72B are connected in series to a terminal on the unlocking side of the switch 101.

Next, the operation of this embodiment will be described.

First, FIG. 3 shows a state in which the crane mechanism 15 is housed in the boom 6. In this state, the buckets 9 are moved up and down by operating the hydraulic cylinders 7, 10 and 11 in cooperation with each other, so that the soil Can be made to dig. This operation is a conventionally known operation.

Next, FIGS. 1 and 2 show a state in which the crane mechanism 15 is pushed out from the boom 6 to lift a heavy load.

First, the operation from the state where the crane mechanism 15 in FIG. 3 is stored to the state where the crane mechanism 15 is pushed out as shown in FIGS. 1 and 2 will be described.

"Boom push-out" First, in Fig. 3, the crane mechanism 15 is stored in the boom 6 and excavation work can be performed. However, this work is temporarily stopped and the operation of extending the crane mechanism 15 is described. To do.

First, the hydraulic cylinders 10 and 11 are operated to rotate the inside of the arm 8 so as to approach the inside of the boom 6. Then, the fixed plate 48 enters between the holding plates 44 and 45, and the bucket 9 enters the bent lower space of the boom 6 as shown in FIG. When the arm 8 enters the lower part of the boom 6, the limit switch 43 operates,
It is detected that the arm 8 is located below the boom 6.
The limit switch 43 operates the relay 87 to close the contacts 91, 95, 102. As the contact 91 is closed, current flows through the coil 63A and the switching valve 6
3, the pressure oil discharged from the hydraulic pump 60 is supplied in the direction of the solenoid valve 64. At this time, since the switch 92 is normally closed, a current flows through the coil 64B, and the pressure oil of the hydraulic pump 64 that has flowed in via the solenoid valve 63 is released by the solenoid valves 70, 7 respectively.
Supplied in 1 and 72 directions.

Then, when the switch 101 for arm lock is tilted to the lock side, the contact 102 is already closed, so that a current flows through the coil 72A and the hydraulic pressure is supplied to the hydraulic cylinder 53. Then, as shown in FIG. 7, the cylinder rod 54 is drawn into the hydraulic cylinder 53, and the angle 51 rotates about the pin 52 in the direction A in the figure. Therefore, the fixing pin 50 passes through the pin holes 47, 49 and 46, and the fixing plate 48
Is connected to the holding plates 44 and 45 and held. When the fixing pin 50 moves further, its tip comes into contact with the limit switch 55 to close the limit switch 55.

Since the limit switch 55 is closed, it is possible to detect that the arm 8 is positioned at the lower portion of the boom 6 and is securely held, and to start the extension / contraction operation of the next boom.

At this time, since the reversing body 35 is in contact with the limit switch 37 and is closed, the relay 86 has already been operated, so the contacts 97 and 99 are closed. When the switches 94 and 98 are operated in conjunction with each other, the current flows through the contact 95 and the limit switch 55 to the coil.
71A to switch the solenoid valve 71. At the same time, current also flows through the coil 70A via the contact 99, so that the solenoid valve 70 is also switched at the same time. Therefore, the hydraulic pressure supplied from the hydraulic pump 60 flows through the solenoid valves 70 and 71 via the pressure reducing valves 67 and 68, respectively. The pressure oil flowing from the solenoid valve 70 passes through the throttle valve 74, and the pressure oil from the hydraulic motor 59 passes through the check valve 77 and returns to the solenoid valve 70 and is returned to the oil tank 62. Further, the pressure oil that has passed through the pressure reducing valve 68 is transmitted to the hydraulic cylinder 73 via the solenoid valve 71 and the throttle valve 78. Return oil from the hydraulic cylinder 73 is returned to the oil tank 62 via the check valve 81 and the solenoid valve 71.

Therefore, the wire 20 is pulled out by the rotation of the take-up drum 26 by the hydraulic motor 26, and the wire 20 begins to loosen, and at the same time, the middle boom 17 and the front boom 18 are pulled out from the original boom 16 by the hydraulic cylinder 73. Become. At this time, the flow rate of the pressure oil flowing through the throttle valves 74 and 78 is set so that the flow rate of the throttle valve 74 is increased, and the hydraulic motor 59 operates so as to rewind the wire 20 a little earlier. Therefore, the amount of extension of the middle boom 17 and the front boom 18 operated by the hydraulic cylinder 73 is
It will be a little later than the amount of 20 return. In this way, the wire 20 is loosened, and the reversal body 35 that has been pulled up by the pulling force of the wire 20 may be slightly inclined due to the looseness of the wire 20 and may be separated from the limit switch 37. However, when the limit switch 37 is opened, the relay 86 stops its operation and the contact 9
Closing 7, 99. Therefore, no current flows through the coil 70A, and the operation of the hydraulic motor 59 is temporarily stopped. However, current still flows in the coil 71A, and the solenoid valve 70
Are in communication with each other, hydraulic pressure is being supplied, the hydraulic cylinder 73 continues to operate, and follows the operation of pushing out the middle boom 17 and the front boom 18. Since the wire 20 is relatively pulled in by the pushing operation of the middle boom 17 tip and the boom 18, the reversing body 35 is flipped up and the limit switch 37 is pushed again to operate the relay 86. Then, the contact 99 is closed, a current is passed through the relay 70A, and the hydraulic motor 59 is operated to rewind the wire 20 in the same manner as described above. That is, the limit switch 37 allows the extension amount of the boom to follow the extension amount of the wire 20.

By repeating such operations, the reversing member 35 does not rotate downward, and the hook receiver 21 is always pushed out while being held by the tip of the front boom 18.

"Switching of hydraulic circuit" As described above, the crane mechanism 15 is operated from the inside of the boom 6, the middle boom 17 and the front boom 18 are pushed out, and finally the head 19 is moved to the arm 8 as shown in FIG. It will move until it projects more than the tip of. At this time, the middle boom 17 is sufficiently extended from the former boom 16, and the limit switch fixed to the side surface of the middle boom 16
42 is exposed to the outside from the tip of the original boom 16, whereby the limit switch 42 is closed and the relay 88 is operated.
Therefore, the contact 90 is closed, the contact 85 is opened by interlocking the relay 85, the contact 93 is closed at the same time, and a current is supplied to the coil 64B. Therefore, the solenoid valve 64 is switched,
The pressure oil from the hydraulic pump 60 is not supplied to the solenoid valves 70, 71, 72, but is transmitted to the switching valves 65, 66.

Therefore, the switching valves 65 and 66 can be controlled manually. And the switching valves 65, 66
The hydraulic motor 59 and the hydraulic cylinder 73 can be operated by operating the.

First, by operating the switching valve 65, the hydraulic motor 59 rotates, and by rewinding the wire 20, the hook receiver 21
Moves down. Further, by operating the switching valve 66, the hydraulic cylinder 73 can be operated and the head 19 can be extended. Then, in the lifting operation of the heavy object, the hook 22 in the hook receiver 21 of the crane mechanism 15 is slid and the hydraulic motor 26 is operated by the operation of the switching valve 65 to wind up the wire 20 and lift the heavy object. . Then, after lifting the heavy object, the position can be moved by operating the hydraulic cylinder 73 if necessary.

Further, when the distance to move the suspended heavy object is long, the crawler 4 is operated while the heavy object is temporarily suspended by the hook 22, and the entire vehicle body 1 is moved to move the heavy object to another work site. You can also carry it.

Next, a series of operations for changing the pushed state of the crane shown in FIGS. 1 and 2 to the stored state shown in FIG. 3 will be described.

"Crane storage" When the crane finishes the suspending operation and shifts to normal excavation work, the wire 20 and hook receiver 21 must be stored in the reverse order to the above.

First, the switching valve 66 is operated so that the hydraulic cylinder 73 is contracted. The middle cylinder 17 and the front boom 18 are housed in the former boom 16 by the hydraulic cylinder 73, and are operated so that the total length becomes shorter. When the middle boom 17 is pulled into the former boom 16 to some extent, the limit switch 42 fixed to the side surface of the middle boom 17 comes into contact with the inner surface of the former boom 16, and the limit switch 42 is closed. This limit switch 42
Closing the relay 88 stops its operation, and at the same time the contact 90 is closed, so the relay 85 stops operating and the contact 92
The contacts 93 are closed at the same time as the contacts are closed. Therefore, a current flows through the coil 64A, the switching valve 64 is switched, pressure oil from the hydraulic pump 60 does not flow through the switching valves 65, 66, and the pressure oil is transmitted to the solenoid valves 70, 71, 72.

Then, in this state, the switches 94 and 98 are respectively tilted to the retracted side. Then, no current flows through the coil 71B, but a current flows through the coil 70B, and pressure oil flows in the reverse direction to the hydraulic motor 59 via the pressure reducing valve 67, the solenoid valve 70, and the throttle valve 75. Return oil from the hydraulic motor 59 is returned to the oil tank 62 through the check valve 76. When the hydraulic motor 59 rotates, the wire 20 is sequentially wound and the hook receiver 21 rises. This state is shown in FIG. 10A.

When the wire 20 is successively wound up, the hook receiver 21 eventually comes into contact with the lower end of the reversing body 35 (see
(See Figure B). When this state is reached, the hook receiver 21 cannot be further lifted.

When the wire 20 is further wound up by operating the hydraulic motor 59 after such a state, the hook receiver 2 is in contact with the lower surface of the reversing body 35.
The pulling force acts on the shaft 36 in the direction of lifting the hook receiver 21 and the reversal body 35 as a whole. For this reason the tenth
As shown in FIG. C, the hook receiver 21 and the reversing body 35 rotate upward about the shaft 36, and the reversing body 35 moves to the limit switch 37.
It will rotate until it touches.

Then, when the reversing body 35 comes into contact with the limit switch 37, the relay 86 operates and the contact 97 is closed. Therefore, a current flows through the coil 71B, the switching valve 71 is switched, and the pressure oil from the hydraulic pump 60 is reduced by the pressure reducing valve 68, the solenoid valve 71, and the throttle valve 79.
Is transmitted to the hydraulic cylinder 73 via. Then, the return oil from the hydraulic cylinder 73 is passed through the check valve 80 to the oil tank.
Returned to 62.

In this way, the hook receiver 21 is held integrally with the head 19 in a state where the reversal body 35 is held in contact with the head 19 and is not shaken by vibration or the like.

After this, as long as the switches 94 and 98 are on the retracted side, the hydraulic motor 26 and the hydraulic cylinder 73 operate simultaneously, and when the wire 20 is wound, the middle boom 17 and the front boom 18 move to the former boom 16. Be drawn inside. During this operation, the amount of oil flowing through the throttle valve 79 is
Since it is set to be larger than the amount of oil flowing through 75, the speed at which the middle boom 17 and the front boom 18 contract is faster than the speed at which the wire 20 is wound.

Therefore, the wire 20 may be loosened during continuous operation, but in this case, the limit switch 37
Since the reversing body 35 separates from the relay 86, the relay 86 temporarily stops operating and the contact 97 is opened. Therefore, the current temporarily stops flowing through the coil 71B, and the operation of the hydraulic cylinder 73 is temporarily stopped. However, since the hydraulic motor 59 continues to operate, the wire 20 is wound and operates to pull up the reversing body 35. Then, as described above, the reversing body 35 comes into contact with the limit switch 37, operates the relay 86 to close the contact 97, causes a current to flow through the coil 71B, and causes the operation of the hydraulic cylinder 73 to follow.

By repeating such a follow-up operation by the hydraulic cylinder 73, the middle boom 17 and the front boom 18 can be retracted inside the former boom 16 while the hook receiver 21 and the reversing body 35 are always held by the head 19. Become.

Then, when the hydraulic cylinder 73 contracts and the middle boom 17 and the front boom 18 are drawn into the inside boom 16, the actuation body 40 comes into contact with the limit switch 41. Therefore, the limit switch 41 actuates the relay 89 to open the contact 100 and close the contact 103.
Therefore, no current flows through the coil 70B, the hydraulic motor 59 stops its operation, the winding operation of the wire 20 is stopped, and the boom retracting operation is stopped.

Next, since the contact 103 is closed by the relay 89, the arm lock can be released. First,
When the switch 101 is operated to switch the switch 101 to the unlocked side, a current flows through the coil 72B and the solenoid valve 72 is switched. Therefore, pressure oil flows in the opposite direction to the hydraulic cylinder 53 and pushes out the cylinder rod 54.
Oscillates in the T direction in Fig. 7 to fix the fixing pin 50 in the pin holes 46, 4
Pull out from 7, 49. Therefore, the fixed plate 48 is fixed to the holding plates 44 and 45.
It can be pulled out from and unlocked.

For this reason, the arm 8 can freely rotate from the boom 6. Therefore, when the hydraulic cylinder 10 is operated to rotate the arm 8 from the boom 6, the limit switch 43 is closed and the relay 87 is operated. Stops operating, contact 91,
Since 95 and 102 are closed, no current flows through the coil 63A, and the solenoid valve 63 returns. As a result, the supply of pressure oil from the solenoid valve 63 to the crane mechanism 15 is stopped, and thereafter all operations of the crane mechanism 15 are stopped.

〔The invention's effect〕

Since the present invention is configured as described above, in the crane mechanism in which the winch mechanism for winding the wire is attached to the boom that expands and contracts, the hook receiver fixed to the tip of the wire does not swing at the tip of the boom without swinging due to vibration. It can be held, and the hook receiver is not rocked by movement of the vehicle body or the like. Further, since the control for storing the hook receiver can be automatically performed, the worker is not required to perform any troublesome work.

[Brief description of drawings]

FIG. 1 is a perspective view of an excavator with a crane showing an embodiment of the present invention, FIG. 2 is a side view showing a state in which the crane mechanism is extended, and FIG. 3 shows the crane mechanism housed in a boom. A side view showing a state for allowing excavation work, No. 4
The figure is a side view with a part cut away to show the crane mechanism inside the boom, FIG. 5 is an enlarged view showing the configuration of the crane mechanism near the tip of the boom, and FIG. 6 is an enlarged view showing the vicinity of the head. FIG. 7 is an enlarged perspective view showing an arm lock mechanism, FIG. 8 is a circuit diagram showing a hydraulic system in this embodiment, FIG. 9 is a circuit diagram showing an electric control system of the same, and FIG. FIG. 11 is an explanatory view showing the movement of the body, FIG. 11 is a flow chart showing the extension movement of the crane in this embodiment, and FIG. 12 is a flow chart showing the movement of the crane contraction in this embodiment. 6 ... boom, 8 ... arm, 15 ... crane mechanism, 16
…… Former boom, 17 …… Medium boom, 18 …… Fast boom, 19…
… Head, 20 …… Wire, 21 …… Hook holder, 22 ……
Hook, 37, 41, 42, 43, 55 ... Limit switch, 53
...... Hydraulic cylinder, 59 …… Hydraulic motor, 64, 70, 7
1, 72 …… Solenoid valve, 73 …… Hydraulic cylinder, 74,75,7
8, 79 …… Throttle valve, 76,77,80,81 …… Check valve.

Claims (1)

[Claims] 1. A crane comprising a telescopic boom, a wire suspended from the tip of the boom for winding and unwinding by a winding mechanism, and a hook receiver suspended under the wire, A crane characterized in that when the crane is stored, the hook receiver is held on the boom at the tip by hoisting the wire and the hook receiver is held so as not to fall from the tip of the boom by synchronizing the boom expansion and contraction of the wire winding. Storage control method.