JP2008261172A - Pile driver with fall prevention device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pile driver with a fall prevention device which prevents the fall of a working device even if a hanging wire breaks. <P>SOLUTION: The pile driver 1 has a working device 20 mounted on a leader 5 erected ahead of a main body, hung by a hanging wire 8. The working device 20 is vertically moved by winding and unwinding the hanging wire 8 by means of a winch 4. The pile driver comprises the fall prevention device 19 slidably mounted on the leader 5 integrally with the working device 20 and provided with ascent/descend restricting mechanisms 10, 12 and 16 between the device itself and the leader 5 to inhibit vertical movement of the working device 20 at an arbitrary height; a break detecting means 9 for detecting a break of the hanging wire 8; and a controller which operates the fall prevention device 19 by receiving a signal from the break detecting means 9 so as to stop the descent of the working device 20 at a predetermined height with respect to the leader 5 by the ascent/descend restricting mechanisms. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pile driving machine in which a working device is slidably mounted on a leader and the working device is moved up and down by a hanging wire from a winch, and in particular, the working device does not fall even when the hanging wire is cut. The present invention relates to a pile driver with a fall prevention device.

  In foundation work for constructing support piles, for example, when a casing is rotationally press-fitted into the ground or when the ground is excavated with a screw rod, a working device such as an auger is attached to the leader of the pile driver so as to be able to move up and down. The casing, screw rod, and the like attached to such an auger are rotated by the auger to excavate the ground, and further, the rotary auger pressed against the ground is performed as the auger descends along the leader along with the rotation.

FIG. 9 is a side view conceptually showing a conventional pile driver. In the pile driving machine 100, two winches 102 and 103 are provided in a main body 101, and a suspension wire 111 fed from one winch 102 is hung on a suspension sheave 151 of an auger 150 via a top sheave 104. . The press-fitting wire 112 sent out from the other winch 103 is hung on the narrowing sheave 152 of the auger 150 through the press-fitting sheave 105. In the pile driving machine 100, the auger 150, which is a working device attached to the leader 106, winds up the winch 103 simultaneously with the lowering of the winch 102, thereby generating a pressure input by the downward pulling force by the winch 103, The screw rod 130 can be forced into the ground.
JP 2001-182061 A (second page, FIG. 1)

  By the way, in such a conventional pile driving machine 1, the guide pipe 113 is formed over the entire length in front of the leader 106, the guide give 155 of the auger 150 is slidably held, and suspended by the suspension wire 111. 106 is slidably attached to 106. Accordingly, since the auger 150 is supported only by the suspension wire 111, if the suspension wire 111 breaks in the event that the auger 150 is lifted, there is a risk that the auger 150 will lose its support and fall. It was.

  Therefore, an object of the present invention is to provide a pile driver with a fall prevention device that prevents the working device from falling even when the suspension wire is broken.

  The pile driving machine with the fall prevention device of the present invention hangs a working device slidably attached to a leader standing in front of the main body by a suspension wire, and by lifting and lowering the suspension wire by a winch A pile driving machine for raising and lowering a working device, which is slidably attached to the leader integrally with the working device, so that the working device cannot be raised and lowered at an arbitrary height. A fall prevention device provided with a lifting restriction mechanism between the wire, a cutting detection means for detecting that the hanging wire is cut, and a signal from the cutting detection means to operate the fall prevention device And a controller for stopping the lowering of the working device at a predetermined height with respect to the reader by the lifting restriction mechanism.

In the pile driving machine with a fall prevention device of the present invention, the elevating restriction mechanism has a rack formed on the leader, and the fall prevention device is provided with a locking disk on a rotation shaft of a pinion gear that meshes with the rack. It is preferable that the locking disk has a rotation stop plate that comes into contact with and separates by the biasing force of the spring and the hydraulic pressure.
In the pile driving machine with a fall prevention device according to the present invention, the elevating restriction mechanism has a disc plate formed on the leader, and the fall prevention device has a chuck for gripping the disc plate with the force of a hydraulic cylinder. It is preferable that

Moreover, the pile driving machine with the fall prevention device of the present invention is connected to the hoisting line of the hydraulic circuit that supplies the working oil to the load cell connected to the suspension wire or the hydraulic motor of the winch. It is preferable that it is a pressure sensor.
The pile driver with a fall prevention device of the present invention includes a solenoid valve piped between the fall prevention device and a hydraulic pump, and a relay connected between the solenoid valve and a power source, The controller is preferably configured to receive a disconnection detection signal from the disconnection detection means and to control the opening and closing of the relay.
Further, the pile driving machine with a fall prevention device of the present invention has a hoisting detecting means for detecting a state in which the winch is rotated in the hoisting direction, and the controller receives a detection signal from the hoisting detecting means, It is preferable to control the opening and closing of the relay when receiving a disconnection detection signal from the disconnection detecting means.

  Therefore, according to the present invention, even if the hanging wire 8 is cut, the controller that receives the signal from the cutting detection means operates the fall prevention device and is provided between the fall prevention device and the reader. The fall of the working device can be stopped by the lift restriction mechanism.

Next, an embodiment of a pile driver with a fall prevention device according to the present invention will be described below with reference to the drawings. FIG. 1 is a side view conceptually showing the pile driving machine with a fall prevention device of the first embodiment. Moreover, FIG. 2 is the figure which showed the front part of the pile driving machine with the fall prevention apparatus.
A pile driver with a fall prevention device (hereinafter simply referred to as “pile driver”) 1 according to the present embodiment is constituted by a base machine provided with a main body 3 capable of turning on a traveling unit 2 provided with a crawler. Yes. The main body 3 is provided with a power unit including a driver's cab and a hydraulic pump on a main frame, and a reader 5 is supported on the front of the main body 3. And this pile driving machine 1 is equipped with the auger 20 which is a working device with respect to the leader 5, Comprising: In this embodiment, the screw rod 80 is connected with the rotating shaft of the auger 20 according to work. Yes.

  The leader 5 is provided with guide pipes 6 on the left and right side surfaces of the machine body over almost the entire length, and the auger 20 is provided with guide gibs 11 for gripping and sliding the guide pipes 6 from the left and right. The pile driving machine 1 is provided with a rack 10 on the front surface of the leader 5, and the auger 20 is integrally provided with a positioning device 19 having a pinion gear 12 that meshes with the rack 10. The positioning device 19 is also provided with guide gibs 13 for gripping the guide pipe 6 from the left and right. Both the auger 20 and the positioning device 19 slide on the guide pipe 6 by the guide gibs 11 and 13 and move up and down along the leader 5. It is installed as possible. The positioning device 19 functions so as to prevent the auger 20 from dropping, and corresponds to the fall preventing device described in the claims.

In the pile driving machine 1, a suspension wire 8 is sent out from a winch 4 provided in the main body 3, and is hung on a suspension sheave 14 of a positioning device 19 via a top sheave 7 at the tip of a leader 5. The suspension wire 8 is connected at its tip to a load cell 9 attached to the top sheave 7. The load cell 9 detects a pulling load applied to the leader 5, and the value is displayed on a load meter in the driver's seat, so that the leader 5 can be operated so as not to be overloaded. It is like that.
Moreover, in the pile driving machine 1 of this embodiment, the auger 20 is suspended by the suspension wire 8, and the auger 20 and the positioning device 19 are pulled up by winding the winch 4. And the rack 10 and the pinion gear 12 are for comprising the raising / lowering limiting mechanism for stopping raising / lowering of the auger 20 by predetermined height.

  The reason why such a positioning device 19 is provided is that the pile driving machine 1 of the present embodiment transmits the pressure input to the screw rod 80 with the positioning device 19 as a support. Specifically, the auger 20 and the positioning device 19 arranged vertically along the leader 5 are connected by a pair of left and right press-fitting cylinders 15 so that the vertical interval is displaced. In other words, when the press-fitting cylinder 15 is expanded and contracted with respect to the positioning device 19 positioned at a predetermined height of the reader 5, a pressure input or a pulling force is applied to the screw rod 80 via the auger 20. The press-fitting cylinder 15 is a backward hydraulic cylinder and is attached in parallel to a position where the screw rod 80 is sandwiched.

  The positioning device 19 has a pair of pinion gears 12 and meshes with a rack 10 having both teeth fixed to the leader 5. The pinion gears 12 and 12 are pivotally supported by the lock unit 16, respectively. As shown in FIG. 3, in the lock unit 16, a lock disk 22 is fixed to the rotation shaft 21 of the pinion gear 12, and a rotation stop plate 23 is provided for the lock disk 22. The rotation stop plate 23 is pressed against the locking disk 22 by the urging force of the spring 24 to stop the rotation, and the rotation plate 23 resists the urging of the spring 24 by the hydraulic oil pressure supplied to the pressurizing chamber. Release to unlock. FIG. 3 is a diagram showing a drive circuit of the lock unit 16.

  The pile driving machine 1 has a hydraulic pump 31, which is connected to the pressurizing chamber 25 of the lock unit 16 via a lock solenoid valve 32. The hydraulic pump 31 is connected to the tank 34 via a relief valve 33. The lock solenoid valve 32 includes an A port block and a B port block shown in the figure, and is switched from the A port block to the B port block by energizing the solenoid so that the hydraulic pump 31 and the pressurizing chamber 25 communicate with each other. It has become. Further, a control line 36 is connected to the locking solenoid valve 32 via a joint 35, and a B contact relay 37 which is opened by a control signal from a controller 60 (see FIG. 3) described later is connected to the control line 36. Is provided.

  Next, FIG. 4 is a diagram showing a hydraulic circuit for rotating the winch 4 of the pile driving machine 1. The winch 4 can be operated by an operation lever 42 in the cab. The remote control valve 41 is configured to perform the switching operation of the pair of switching valves 43 and 44 by the inclination of the operation lever 42. The switching valves 43 and 44 are connected to a pilot pressure hydraulic pump (not shown) for supplying pilot pressure and a tank 45 to switch the control valve 46. The switching valves 43 and 44 are connected to the pilot chamber of the control valve 46 via a winding side pilot line 47 or a lowering side pilot line 48.

  The control valve 46 is configured to switch the hydraulic oil from the hydraulic pump 49 to the hydraulic motor 53 of the winch 4 through the winding line 51 and the unwinding line 52 and supply the hydraulic oil. A counter balance valve 55 is provided between the control valve 46 and the motor 53. The control valve 46 is provided with a center bypass line 56 for connecting the hydraulic pump 48 and the tank 45, and a tank line 58 provided with a relief valve 57 is connected thereto. In the present embodiment, a pressure switch 61 is connected to the winding side pilot line 47, and it is possible to confirm the winding operation by detecting the pilot pressure.

  Subsequently, in this embodiment, the pile driving machine 1 excavates the ground using the screw rod 80 as follows. At the start of work, the auger 20 and the positioning device 19 are pulled up along the leader 5 by winding up the winch 4, and the screw rod 80 is connected to the rotating shaft of the auger 20. The auger 20 and the positioning device 19 are excavated in a state in which the press-fitting cylinder 15 is in a contracted state and both are close to each other. In the excavation by the screw rod 80, the suspension wire 8 is lowered by the winch 4, and the screw rod 80 is rotated by the output from the auger 20, whereby the weight of the auger 20 and the positioning device 19 and the propulsive force of the spiral wings entering the ground. Excavation is performed.

  As shown in FIG. 3, the positioning device 19 in the case where the excavation is proceeding smoothly is such that the rotation stop plate 23 is separated from the lock unit 16 by hydraulic pressure, and the rotation of the pinion gear 12 is in a free state. Accordingly, when the auger 20 descends along the leader 5 along with excavation, the positioning device 19 also descends, and the free pinion gear 12 rolls on the rack 10 accordingly.

  On the other hand, when the screw rod 80 hits the hard ground and does not enter any more, the hydraulic pressure acting on the pressurizing chamber 25 of the positioning device 19 is released, and the anti-rotation plate 23 is applied by the urging force of the spring 24. Is pressed against the locking disk 22 to lock the rotation. As a result, the rotation of the pinion gear 12 is restricted, so that the positioning device 19 is positioned at a predetermined height with respect to the reader 5 while being engaged with the rack 10. Then, hydraulic oil is supplied to the press-fitting cylinder 15 in a contracted state, and the screw rod 80 is forcibly press-fitted into the hard ground via the auger 20.

  When the screw rod 80 is pulled out, the winch 4 is wound up with the positioning device 19 unlocked, and the auger 20 and the positioning device 19 are pulled up by the suspension wire 8. At the time of pulling out, the screw rod 80 is pulled up by the hoisting force of the winch 4, but if that is not sufficient, the rotation of the pinion gear 12 is restricted by the lock unit 16 with the press-fit cylinder 15 extended, and the positioning device 19 is moved. After positioning, the press-fit cylinder 15 is contracted to forcibly raise the auger 20 and the screw rod 80.

  By the way, raising / lowering of the auger 20 as mentioned above is performed by the following operations of the pile driving machine 1. When the operation lever 42 is in the neutral state as shown in FIG. 4, the hydraulic oil from the hydraulic pump 49 flows to the tank 45 through the control valve 46. Therefore, when the operation lever 42 is tilted to the winding side to raise the auger 20, the switching valve 43 is switched by the operation lever 42, and the pilot pressure switches the control valve 46 to the A port block. Therefore, the hydraulic oil from the hydraulic pump 49 flows through the winding line 51 and rotates the hydraulic motor 53 in the winding direction.

  Conversely, when the operating lever 42 is tilted in the lowering direction, the switching valve 44 is switched and the pilot pressure switches the control valve 46 to the B port block. Therefore, the hydraulic oil from the hydraulic pump 49 flows through the lowering line 52 and rotates the hydraulic motor 53 in the reverse direction. At this time, the counter balance valve 55 is opened by the hydraulic pressure flowing through the lowering line 52, and the returned hydraulic fluid flows through the hoisting line 51 through the counter balance valve 55.

  By the way, when the auger 20 is moved up and down, the locking of the positioning device 19 is released. Therefore, if the suspension wire 8 is cut by any chance, the auger 20 falls and it is dangerous. However, in the pile driving machine 1 of this embodiment, the positioning device 19 functions as a fall prevention device, thereby avoiding the danger of dropping. FIG. 5 is a system diagram for performing fall prevention in such a pile driver. That is, the controller 60 provided in the pile driving machine 1 is configured to receive signals from the load cell 9 and the pressure switch 61 and operate the relay 37.

  The suspension wire 8 is subjected to a tensile load particularly when it is wound up, so that there is a risk of cutting. Therefore, in the present embodiment, as shown in FIG. 4, a pressure switch 61 is connected to the winding pilot line 47 to detect the winding operation of the winch 4. That is, the pilot pressure is applied to the winding pilot line 47 by tilting the operation lever 42 to the winding side, and a signal from the pressure switch 61 that detects the pressure is sent to the controller 60. The controller 60 can confirm that the winding operation is being performed by receiving a signal from the pressure switch 61 (S1: YES).

  Thereafter, the controller 60 receives the load signal from the load cell 9 and determines the cutting state of the hanging wire 8 (S2). Specifically, when the tensile load applied to the load cell 9 shows a value smaller than 1 ton, it is determined that the wire has been cut. Accordingly, in the normal state, the pulling load of 1 ton or more is applied to the hanging wire 8 by pulling up the auger 20 or the like. Therefore, when the load value P is 1 ton or more (S2: NO), the controller 60 confirms the winding operation ( S1) and load confirmation (S2) are repeated. On the other hand, when the suspension wire 8 is cut, the load applied to the load cell 9 falls below 1 ton (S2: YES), and an open signal is sent from the controller 60 that receives the load signal P to the relay 37.

  Therefore, the relay 37 of the B contact shown in FIG. 3 is turned off by the open signal, and the locking solenoid valve 32 is deenergized and switched from the B port block to the A port block shown in the figure. Then, the pressurizing chamber 25 of the lock unit 16 communicates with the tank 34, and the rotation stop plate 23 is pressed against the lock disk 22 by the urging force of the spring 24. Therefore, the rotation of the pinion gear 12 that rolls on the rack 10 is restricted, the brake is applied, and the fall of the auger 20 is stopped.

  By the way, the pile driving machine 1 is provided with a release switch for releasing the lock when the safety is secured after the fall prevention. Therefore, when the suspension wire 8 is cut (S2: YES), the state of the release switch is confirmed (S3), and if the release switch is not pushed, the fall prevention state is continued (S3: NO). When safety is ensured and the release switch is pressed (S3: YES), the relay 37 is returned to the normal state, and the positioning device 19 can be raised and lowered.

  Therefore, according to the pile driving machine 1 of the present embodiment, even if the hanging wire 8 is cut, the positioning device 19 becomes a fall prevention device and can stop the dropping of the auger 20. . Further, in the present embodiment, the positioning device 19 is used, and the press-fitting cylinder 15 enables forced press-fitting and extraction, and the positioning device 19 is used as a fall prevention device, so that the cost can be reduced while increasing the effect and the safety. The pile driver was improved in nature.

Next, a second embodiment of the pile driver will be described. FIG. 6 is a view showing a hydraulic circuit for rotating the winch of the pile driving machine. This uses a pressure sensor 62 instead of the load cell 9 used in the first embodiment. Accordingly, the same components as those in the first embodiment will be described with the same reference numerals.
The pressure sensor 62 is a line that supplies hydraulic oil to the hydraulic motor 4 of the winch 4, and is connected to the winding line 51 in particular, and detects the hydraulic pressure at the time of winding. A pressure signal of the pressure value detected by the pressure sensor 62 is transmitted to the controller 60 instead of the load cell 9 shown in FIG.

  Therefore, as in the first embodiment, during a hoisting operation in which the operation lever 42 is tilted to the hoisting side, pilot pressure is applied to the hoisting side pilot line 47, and a signal from the pressure switch 61 that detects this is sent to the controller 60. (See FIG. 5). The controller 60 can confirm that the winding operation is being performed when a signal from the pressure switch 61 is input (S1: YES). Thereafter, the controller 60 receives the pressure signal from the pressure sensor 62 and determines the cutting state of the hanging wire 8 (S2). That is, when the suspension wire 8 is cut during winding, the load on the hydraulic motor 53 is reduced and the pressure in the winding line 51 is reduced.

Therefore, in a normal state, the load of the hydraulic motor 53 is large for winding the suspension wire 8, and the pressure sensor 62 detects a high value of the hydraulic pressure in the winding line 51. Based on the detection signal (S2: NO), the controller 60 repeats the winding operation confirmation (S1) and the hydraulic pressure confirmation (S2). When the suspension wire 8 is cut, the value of the pressure sensor 62 suddenly drops and falls below the set value, so that the controller 60 receives the pressure signal and sends an open signal to the relay 37 (S2: YES), the fall prevention state continues until the release switch is pressed (S3: NO).
Therefore, even in the pile driving machine according to the present embodiment, even if the hanging wire 8 is cut, the positioning device 19 can prevent the auger 20 from falling, and the positioning device 19 can be prevented from falling. By using it as a device, it was possible to obtain a pile driver that increased its safety by reducing costs as well as its effects.

Next, a third embodiment of the pile driver will be described. The pile driving machine with a fall prevention device according to the present embodiment has a different configuration of the positioning device 19 of the pile driving machine according to the first embodiment. Here, FIG. 7 is a side view conceptually showing the pile driving machine of the third embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals. FIG. 8 is a diagram showing the positioning device and its drive circuit of the present embodiment.
This pile driving machine 70 is configured by a positioning device 71 different from the first embodiment. The positioning device 71 is provided with a chuck 72 on which a pair of bent gripping claws 72 a and 72 a are pivotally supported, and is opened and closed by a hydraulic cylinder (chuck cylinder) 73. On the other hand, not the rack but the disk plate 74 is attached to the entire surface of the reader 5, and the positioning device 71 is configured such that the tip of the chuck 72 sandwiches the disk plate 74.

  The chuck cylinder 73 is connected to the hydraulic pump 31 via a locking solenoid valve 32, and the hydraulic pump 31 is further connected to the tank 34 via a relief valve 33. The solenoid valve for locking 32 is switched from the A port block to the B port block by energizing the solenoid so that the hydraulic pump 31 and the chuck cylinder 73 communicate with each other. Further, control lines 75 and 76 are connected to the locking solenoid valve 32 via the joint 35, and energization is performed via the control line 75 under the control of the controller 60 (see FIG. 3). It is connected to a power source via a relay 77 having an A contact which is closed by a signal from 60.

  In the pile driving machine 70, the auger 20 and the positioning device 71 are connected by the press-fit cylinder 15, and excavation is performed in a state where the press-fit cylinder 15 is contracted. At that time, the suspension wire 8 is unwound by the winch 4. When the excavation is proceeding smoothly, the positioning device 71 is in a state in which the chuck cylinder 62 is in a state where the tip of the chuck 72 is in sliding contact with the disk plate 74 while the hydraulic pressure is released. On the other hand, when forced press-fitting is performed, hydraulic pressure in the extending direction acts on the chuck cylinder 62 of the positioning device 60, and the tip of the chuck 61 strongly holds the disk plate 74 from both sides and locks it by the frictional force. When the press-fitting cylinder 15 is extended, the extension force is transmitted to the screw rod 80 through the auger 20, and forced press-fitting into the hard ground is performed.

  On the other hand, when pulling out the screw rod 80, the winch 4 is wound up with the positioning device 71 unlocked, and the auger 20 and the positioning device 60 are pulled up by the suspension wire 8. When pulling out, the screw rod 80 is pulled up by the hoisting force of the winch 4. However, if this is not sufficient, the disc plate 74 is held by the chuck 72 with the press-fit cylinder 15 extended, and the positioning device 71 is fixed. Then, the press-fit cylinder 15 is contracted to forcibly pull up the auger 20 and the screw rod 80.

  By the way, when raising and lowering the auger 20, since the locking of the positioning device 71 is released, the auger 20 falls and is dangerous if the hanging wire 8 is cut by any chance. Therefore, in this embodiment, as in the first embodiment, when the hanging wire 8 is cut, the controller 60 receives a signal from the load cell 9 or the pressure switch 61 (see FIG. 4) and operates the relay 77. The auger 20 is prevented from falling. That is, as shown in FIG. 5, the controller 60 confirms that the winding operation is being performed (S1: YES), and confirms that the suspension wire 8 has been broken by the signal from the load cell 9, the closing signal is sent to the relay 77. Is sent (S2: YES), and the fall prevention state is continued until the release switch is pressed (S3: NO).

As a result, the locking solenoid valve 32 is switched from the A port block to the B port block by energization, and the chuck 72 grips the disk plate 74 by the hydraulic oil to the chuck cylinder 73, and the auger 20 is prevented from dropping by the friction force. It is done.
Therefore, according to the pile driving machine 70 of the present embodiment, even if the hanging wire 8 is cut, the positioning device 71 becomes a fall prevention device and can stop the dropping of the auger 20. . Further, in this embodiment, the positioning device 71 is used, and the press-fitting cylinder 15 enables forced press-fitting and drawing, and the positioning device 71 is used as a fall prevention device, so that the cost can be reduced while increasing the effect and the safety. The pile driver was improved in nature.

As mentioned above, although one embodiment of the pile driving machine with a fall prevention device concerning the present invention was described, the present invention is not limited to this but various changes are possible within the range which does not deviate from the meaning.
In the above-described embodiment, the rack 10 and the pinion gear 12 and the chuck 72 and the disk plate 74 are used as the lifting restriction mechanism. However, other structures may be used.
Further, the working device attached to the leader of the pile driver is not limited to the auger 20.

It is the side view which showed notionally 1st Embodiment of the pile driver with a fall prevention apparatus. It is the figure which showed the front part of the pile driver with a fall prevention apparatus. It is the figure which showed the drive circuit of the lock unit. It is the figure which showed the hydraulic circuit for rotating the winch of a pile driver with a fall prevention apparatus. It is a system diagram for fall prevention in a pile driver with a fall prevention device. It is the figure which showed the hydraulic circuit which rotates the winch in the pile driver with the fall prevention apparatus of 2nd Embodiment. It is the side view which showed notionally 3rd Embodiment of the pile driver with a fall prevention apparatus. It is the figure which showed the positioning device and its drive circuit in the pile driving machine with a fall prevention device of 3rd Embodiment. It is the conceptual diagram which showed the conventional pile driver provided with the forced pushing mechanism using a winch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pile driver with fall prevention apparatus 2 Traveling part 3 Main body 4 Winch 5 Leader 8 Hanging wire 9 Load cell 10 Rack 12 Pinion gear 15 Press-in cylinder 19 Positioning device 20 Auger 22 Locking disk 23 Rotation stop plate 24 Spring 31 Hydraulic pump 32 For locking Solenoid 37 Relay 41 Remote control valve 42 Operation levers 43 and 44 Switching valve 46 Control valve 53 Hydraulic motor 80 Screw rod

Claims (6)

A pile driving machine that suspends a working device slidably attached to a leader standing in front of a main body with a suspension wire and raises and lowers the work device by winding and lowering the suspension wire with a winch,
A fall prevention mechanism provided with an elevating restriction mechanism between the work device and the reader so that the work device can be slidably attached to the reader and cannot be raised or lowered at an arbitrary height. Equipment,
Cutting detection means for detecting that the hanging wire is cut;
A controller that receives the signal from the cutting detection means and operates the fall prevention device to stop the lowering of the working device at a predetermined height with respect to the reader by the elevation restriction mechanism; A pile driver with a fall prevention device. In the pile driver with the fall prevention device according to claim 1,
The elevating / lowering mechanism includes a rack formed in the leader, the fall prevention device includes a locking disk provided on a rotation shaft of a pinion gear that meshes with the rack, and the locking disk includes a spring biasing force and hydraulic pressure. A pile driving machine with a fall prevention device, characterized in that it has a rotation stop plate that comes into contact with and separates by means of an anti-falling device. In the pile driver with the fall prevention device according to claim 1,
A pile driving machine with a fall prevention device, wherein the elevating restriction mechanism has a disc plate formed on the leader, and the fall prevention device has a chuck for gripping the disc plate with the force of a hydraulic cylinder. . In the pile driver with the fall prevention device according to any one of claims 1 to 3,
The disconnection detecting device is a pressure sensor connected to a load cell connected to the suspension wire or a hoisting line of a hydraulic circuit that supplies hydraulic oil to the hydraulic motor of the winch. With a pile driver. In the pile driver with the fall prevention device according to any one of claims 1 to 4,
A solenoid valve piped between the fall prevention device and the hydraulic pump, and a relay connected between the solenoid valve and a power source,
The pile driving machine with a fall prevention device, wherein the controller is configured to control opening and closing of the relay in response to a cutting detection signal from the cutting detecting means. In the pile driver with the fall prevention device according to claim 5,
The controller includes a winding detection unit that detects a state in which the winch is rotated in the winding direction, and the controller receives a detection signal from the winding detection unit, and further receives the cutting detection signal from the cutting detection unit. A pile driver with a fall prevention device, wherein the opening and closing of the relay is controlled.

Images