JPH08269956A - Elevation device for working platform for pile constructing machine - Google Patents

Abstract

PURPOSE: To enhance the safety by preventing wires from breakage or the like. CONSTITUTION: A working platform is hung by wires 48. 50 led from a winch 56, and load cells 114, 116 are furnished to sense the load applied to sheaves 102a, 102b in contact with the wires. When the load given by the load cells lies within the specified range, control valves 86, 100 are turned over so that the winch 56 is driven. When the load is exceeding the specified level, the valves 86, 100 are turned over to stop operation of the winch 56, and information about over-load is issued. When the load is below the specified level, the drive of winch is stopped, and information about down failure is emitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for connection work, maintenance work, inspection work and the like between an auger drill and piles and a construction mechanism such as an auger drive mechanism and a hammer mechanism which are moved up and down along a guide rail provided on a leader. The present invention relates to a workbench lifting device for a pile construction machine that lifts and lowers a workbench used.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 5-331855, a workbench is supported so that it can be raised and lowered along a guide frame provided on a leader, and a wire having one end fastened to the workbench is used as a sheave. After winding, it is wound around a drum on the vehicle body, and the drum is rotated by a hydraulic motor to wind or unwind the wire to raise and lower the workbench. And in order to prevent the wire from being overwound or overwound, limit switches are provided at the upper limit and the lower limit,
The drive of the winch is stopped. Further, it is known that a switch for detecting the breakage of the wire is provided in the same manner and the winch is stopped even when the breakage occurs.

[0003]

However, in such a conventional one, there is an obstacle such as an eaves of an adjacent building on the way of ascending, and even if the workbench strikes, the operation is continued if the worker does not notice it. If the wire does not break, the operation of the winch does not stop and the wire break cannot be prevented in advance. Also, due to the twisting of the sliding surface between the guide rail and the workbench, etc., the workbench suddenly stops when the workbench stops descending and the wire is loosened, and then the workbench suddenly descends when the twist is eliminated. was there.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a work platform elevating / lowering device for a pile construction machine, which aims to solve the above-mentioned problems and which prevents wire breakage and the like in advance to improve safety.

[0005]

In order to achieve such an object, the present invention has the following constitution as means for solving the problem. That is, in the work platform lifting device for the pile construction machine, which raises and lowers the work platform supported movably along the guide rails provided on the leader installed upright,
For a pile construction machine, comprising: load detecting means for detecting a load on the drive mechanism; and control means for stopping the lifting / lowering by the drive mechanism according to the load detected by the load detecting means. That is the structure of the work platform lifting device.

The drive mechanism may be a winch in which the workbench is suspended by a wire, and the load detecting means may detect a load according to the tension of the wire, or the load detecting means may drive the drive. It may be configured to detect the reaction force applied to the mechanism. Further, the control means may be configured to notify an overload when the load detected by the load detection means is equal to or more than a predetermined value, and notify a descent abnormality when the load is equal to or less than the predetermined value.

[0007]

In the work platform raising / lowering device for a pile construction machine having the above structure, the drive mechanism moves the work platform up and down along the guide rails. The load detection means detects the load on the drive mechanism, and the control means stops the ascending / descending by the drive mechanism according to the load detected by the load detection means.

When the driving means is a winch, the load detecting means detects the load according to the tension of the wire. When the load detecting means detects the reaction force, the load detecting means detects the load by the reaction force applied to the drive mechanism. When the control means notifies the overload and the lowering abnormality, the control means notifies the overload when the load detected by the load detecting means is a predetermined value or more, and notifies the lowering abnormality when the load is the predetermined value or less. .

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 2, reference numeral 1 denotes a main body of a self-propelled pile construction machine using crawlers. It is supported so that it can be turned.

Two long first guide rails 8 and 10 having a circular cross section are laid along the longitudinal direction of the leader 2 (see FIG. 4), and the first guide rails 8 and 10 are provided on the first guide rails 8 and 10. The auger drive mechanism 12 is slidably engaged with the first guide rails 8 and 10 via a plurality of guide gibs 14. The auger drive mechanism 12 is a rotary shaft 1 described later.
It is configured to rotationally drive an auger drill 16 attached to the No. 5 unit.

A pushing mechanism 18 connected to the auger drive mechanism 12 is slidably engaged with the first guide rails 8 and 10 via a plurality of guide gibs 20. Has been done. The pushing mechanism 18 is a pile 19
It is configured such that an axial pushing force is applied to the.

The auger drive mechanism 12 includes a hanging sheave 22.
Is rotatably supported, one end of the wire 24 is fastened to the upper end of the leader 2, and a plurality of hanging sheaves 22 and a plurality of sheaves 26 rotatably supported on the upper end of the leader 2. After being wrapped around, the sheave 28 is rotatably supported on the upper end of the leader 2.

Further, the wire 24 is wound around a rotary drum 34 of a main winch 32 provided in the pile construction machine main body 1 via a sheave 30 rotatably supported in the middle of the leader 2, and the main winch 32 is provided. Driven by auger drive mechanism 1
2. The pushing mechanism 18 can be moved up and down.

Further, in the leader 2, second guide rails 36 and 3 having a circular cross section are arranged in parallel with the first guide rails 8 and 10.
8 is laid, and a movable table 42 is secondly mounted on the second guide rails 36 and 38 via a plurality of guide givers 40.
It is slidably engaged along the guide rails 36 and 38.

A box-shaped boarding base 46 on which an operator can board is attached to the moving base 42.
One ends of the two wires 48 and 50 are fastened. The wires 48, 50 are hung around a pair of sheaves 52a, 51b, 54a, 54b rotatably supported on the upper end of the reader 2 and are attached to the lower end side surface of the reader 2 for a work table as a drive mechanism. It is wound around the drum 58 of the winch 56. In this embodiment, a workbench 60 is formed by the guide give 40, the moving table 42, and the boarding table 46.

As shown in FIG. 1, the work table winch 56 has a large gear 6 on a side surface of a drum 58 which is rotatably supported.
1 is integrally fixed, and a small gear 64 attached to the rotary shaft of a hydraulic motor 62 is meshed with the large gear 61. Further, the workbench winch 56 is provided with a brake mechanism 66 for braking the rotation of the drum 58. The brake mechanism 66 releases the brake when high pressure hydraulic oil is supplied to the cylinder 68, and the hydraulic oil is released. Is a well-known drum brake that brakes the rotation of the drum 58 by the urging force of a spring (not shown) or the like when the supply of R is stopped.

On the other hand, it is provided with a hydraulic pump 72 for a motor and a hydraulic pump 74 for a cylinder which are driven by the internal combustion engine 70 of the main body 1 of the pile construction machine, and the hydraulic pump 72 for the motor is constituted by the hydraulic motor 62 and the flow passage 76 for the motor. Connected,
The hydraulic oil from the tank 78 is pressurized and discharged to the motor flow path 76. The motor flow path 76 is connected to a return flow path 82 that communicates with a tank 78 via a relief valve 80, and a motor supply valve 84 and a motor control valve 86 are connected to the motor flow path 76. It is equipped.

The motor supply valve 84 includes a motor flow path 76.
And a cutoff position 84b that cuts off the motor flow path 76 and connects the motor hydraulic pump 72 side to the return flow path 82, and switches to the communication position 84a when an exciting current is input. is there.

The motor control valve 86 includes a motor flow path 76.
To the hydraulic motor 62 by supplying hydraulic oil to the hydraulic motor 62 for normal rotation, a stop position 86b for shutting off the motor flow path 76, and the hydraulic flow path 62 for communicating with the hydraulic motor 62. Reverse rotation position 86c for supplying oil and rotating in reverse
It is possible to selectively switch to the forward rotation position 86a or the reverse rotation position 86c according to the input of the exciting current.

On the other hand, the cylinder hydraulic pump 74 is connected to the cylinder 68 by a cylinder flow path 94,
Cylinder flow path 94 by pressurizing hydraulic oil from tank 78
To discharge. The cylinder flow path 94 is connected to the return flow path 82 via a relief valve 96.

A cylinder supply valve 98 and a cylinder control valve 100 are interposed in the cylinder flow path 94.
The cylinder supply valve 98 includes a communication position 98a that communicates with the cylinder flow path 94 and a cutoff position 98b that blocks the cylinder flow path 94, and is switched to the communication position 98a when an exciting current is input. .

The cylinder control valve 100 is provided with a braking position 100a that shuts off the cylinder flow path 94 and an open position 100b that connects the cylinder flow path 94 and supplies hydraulic oil to the cylinder 68. At the time of input, it is switched to the open position 100b.

On the other hand, a pair of sheaves 52 at the upper end of the leader 2
Detection sheaves 102a, 102b are provided between a, 52b 54a, 54b so as to contact the wires 48, 50 and push down the wires 48, 50 in a "V" shape. The detection sheaves 102a and 102b are
As shown in FIG. 5, a pair of bearings 104,
It is rotatably supported by a support shaft 108 via 106.

The support shaft 108 includes a pair of support plates 110, 1
The support plate 11 is inserted into the support plate 12 and supported at both ends.
Detection shafts 115 of load cells 114 and 116 as load detection means are inserted at the lower ends of 0 and 112.
Further, the detection shafts 115 of the load cells 114 and 116 are rotatably inserted into a fixed plate 118 fixed to the upper end of the reader 2.

The load cells 114 and 116 are provided with a detection shaft 11
The load cell 114, 116 is a well-known device that converts the load applied to the load 5 into an electric signal and outputs the electric signal.
The motor supply valve 84, the motor control valve 86, the cylinder supply valve 98, and the cylinder control valve 100 are connected to the electronic control circuit 150.

The electronic control circuit 150 is a well-known CPU 15
2, an input / output circuit 15 configured as a logical operation circuit mainly including the ROM 154, the RAM 156, etc., and performing input / output with the outside
8 are mutually connected via a common bus 160.
The CPU 152 inputs input signals from the load cells 114 and 116 and the operation switch 162 via the input / output circuit 158, and these signals and the ROM 154 and the RAM 156.
Based on the data in the control program and the stored control program, the CPU 152 causes the motor supply valve 84, the motor control valve 86, and the cylinder supply valve 9 via the input / output circuit 158.
8. Output a drive signal to the cylinder control valve 100.

In this embodiment, the winch 56 for workbench is used.
Is provided in the reader 2, but a winch 56 for a workbench may be provided on the workbench 60 instead of this. In this case, the wires 48 and 50 may be fastened to the upper end of the reader 2 via load detecting means such as a load cell to detect the load.

Next, the operation of the work platform elevating / lowering device for the pile construction machine according to the present embodiment described above will be described with reference to the construction by the hollow digging pile method. While the auger driving mechanism 12 rotates the auger drill 16 inserted in the hollow inside of the pile 19, the pushing mechanism 18 applies a pressing force in the axial direction to build the pile 19. Then, when the main winch 32 is driven by the auger drive mechanism 12 and the push-in mechanism 18 when the main winch 32 is installed at a predetermined depth.
Raise along the guide rails 8 and 10. Next, a new pile 19 is added and the auger drills 16 are connected to each other.

On the other hand, when the internal combustion engine 70 is in operation, the motor hydraulic pump 72 and the cylinder hydraulic pump 74 are driven to pressurize and discharge hydraulic oil from the tank 78. When the motor supply valve 84 is at the shutoff position 84b, the hydraulic oil discharged from the motor hydraulic pump 72 is
Motor flow path 76, motor supply valve 84, return flow path 82
It is returned to the tank 78 via. Further, when the cylinder supply valve 98 is at the shutoff position 98b, the hydraulic oil is returned to the tank 78 via the cylinder flow path 94, the relief valve 96, and the return flow path 82.

The motor supply valve 84 is connected to the communication position 8
4a and the cylinder supply valve 98 is switched to the communicating position 98a, the motor flow path 7
6, hydraulic oil is supplied to the motor control valve 86 via the switching valve 122, and to the cylinder control valve 100 via the cylinder flow path 94 and the switching valve 126.

When the motor control valve 86 is switched to the forward rotation position 86a and the cylinder control valve 100 is switched to the open position 100b by operating the operation switch 162, first, the cylinder 68 and the cylinder hydraulic pump 74 are switched. High pressure hydraulic oil from the cylinder supply valve 9
8, the cylinder flow path 94, the switching valve 126, and the cylinder control valve 100. Therefore, the cylinder 68
Is driven, and the brake of the brake mechanism 66 is released.

In the hydraulic motor 62, the high-pressure hydraulic oil from the motor hydraulic pump 72 is supplied to the motor supply valve 84,
Motor flow path 76, switching valve 122, motor control valve 86
Is supplied via Therefore, the small gear 64 of the hydraulic motor 62 is normally rotated, the wires 48 and 50 are wound by the drum 58 via the large gear 61, and the workbench 60 is raised. On the other hand, when the motor control valve 86 is switched to the reverse rotation position 86c, the small gear 64 of the hydraulic motor 62 is
Is reversely rotated, the wires 48 and 50 are paid out from the drum 58, and the workbench 60 is lowered.

When stopping the raising and lowering of the workbench 60,
The motor control valve 86 is switched to the stop position 86b, and the cylinder control valve 100 is switched to the braking position 100a. Therefore, the motor flow path 76 and the cylinder flow path 94 are blocked, the supply of hydraulic oil is stopped,
The drive of the hydraulic motor 62 is stopped, and the drum 58 is braked by the brake mechanism 66.

An operator boards the platform 46 and drives the platform winch 56 to drive the platform 6 as described above.
0 is raised along the second guide rails 36 and 38 to near the tip of the auger drill 16. At this time, another worker on the work surface 60 may operate the work table winch 56 in accordance with an instruction from the work table 60, or a worker on the work table 60 may operate the work table 60. It may be operated remotely on the above.

Next, the operator on the workbench 60 instructs another operator on the ground side to operate the main winch 32 and lower the auger drive mechanism 12. At that time, an operator on the workbench 60 performs centering while moving the auger drill 16 so that the rotation shaft 15 of the auger drive mechanism 12 and the auger drill 16 are in phase when connected.

After inserting the auger drill 16, the board 4
The worker on 6 inserts the connecting pin 132 into the pin insertion hole 130 of the rotary shaft 15 with a hammer or the like. After the connection work is completed, the work table winch 56 is driven to move the board 4
Drop 6 While driving the auger drive mechanism 12 to rotate the auger drill 16 as described above,
Build the pile 19.

On the other hand, when the operation switch 162 is operated during the switching of the motor control valve 86 and the cylinder control valve 100, the motor control valve 86 and the cylinder control valve 100 are switched as described above. The workbench 60 is moved up and down. Further, control processing is executed in the electronic control circuit 150. The control process will be described below with the flowchart of FIG. In this embodiment, the execution of the control process works as the control means.

First, when the operation switch 162 is turned on (step 200), the load P is detected by the input signals from the load cells 114 and 116 (step 210).
Next, based on this load P, the tension F of the wires 48, 50 is calculated by the following formula (step 220). Note that θ
Is the angle of the wires 48, 50 with respect to the horizontal direction.

F = P / (2 × SIN θ) Then, when the tension F is calculated, the tension F is a predetermined minimum value F.
It is determined whether it is between min and the maximum value Fmax (step 230). Tension F is minimum Fmin and maximum Fmax
If it is between 0 and, the motor control valve 86 and the cylinder control valve 100 are switched according to the operation switch 162 as described above, and the work table winch 56 is driven (step 240). In addition, the tension F is applied to each wire 4
The tension F of each wire 48, 50 can be monitored by calculating every 8, 50.
It is also possible to use an average value of 0.

On the other hand, if it is determined in step 230 that the tension F is equal to or greater than the maximum value Fmax, the motor control valve 86 and the cylinder control valve 100 are switched to the stop position 86b and the braking position 100a, respectively. The driving of the workbench winch 56 is stopped (step 250).

For example, when the workbench 60 hits the eaves or the like of an adjacent building while the workbench 60 is rising and the workbench winch 56 is driven as it is, the weight of the workbench 60 and the weight of the worker on board the wires 48 and 50. A load other than the weight and the weight of other devices mounted on the workbench 60 is applied.

These loads are applied to the load cells 114 and 116.
Is detected and the driving of the workbench winch 56 is stopped.
Then, an unillustrated display, a display lamp, or the like is displayed to indicate to the operator that the load is excessive (step 260). The maximum value Fmax is set in advance as a value that does not cause the wires 48 and 50 to break or the work table 60 to break when an overload is applied to the wires 48 and 50.

If it is determined in step 230 that the tension F is less than the minimum value Fmin, the motor control valve 86 and the cylinder control valve 100 are switched to the stop position 86b and the braking position 100a, respectively. The driving of the workbench winch 56 is stopped (step 270). For example, when the workbench 60 is descending, the guide rails 36, 38 and the guide give 40 are twisted and slid to cause the wire 4 to move.
Although 8 and 50 are fed out, a situation may occur in which the workbench 60 does not descend.

In such a case, the tension F applied to the wires 48 and 50 is the weight of the workbench 60, the weight of the worker on board, and the weight of other equipment mounted on the workbench 60. Much lighter than by. Therefore, the driving of the workbench winch 56 is stopped, and it is displayed on a display, a display lamp, or the like (not shown) that the descent is abnormal, and the operator is notified (step 280). This minimum value Fmin
Is preset to a value in which the tension F of the wires 48, 50 is smaller than the tension F when the wire is normally lowered. When the process of step 240 is executed, the processes of step 200 and subsequent steps are repeated to constantly monitor the tension of the wires 48, 50. Further, when the processes of step 260 and step 280 are executed, this control process is once terminated.

As a result, when the tension F is equal to or higher than the maximum value Fmax, the driving of the workbench winch 56 is stopped and the overload is notified to break the wires 48 and 50 and the workbench 60. And to inform the operator that it is overloaded. At this time, the workbench 6
Similar processing is performed even when the overload is 0.

When the tension F is less than the minimum value Fmin, the driving of the workbench winch 56 is stopped, and the descending abnormality is notified to prevent the workbench 60 from suddenly descending rapidly. At the same time, the operator is informed that the descent is abnormal. Next, a second embodiment different from the above-mentioned embodiment will be described with reference to FIGS. The same members as those in the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, the sheave 102 for detection is used.
Instead of a and 102b, a winch base 200 rotatably supporting a drum 58 of a work bench winch 56 is rotated by a fulcrum pin 204 orthogonal to the axial direction of the reader 2 on a support plate 202 fixed to the reader 2. Supported as possible. The load cell 20 parallel to the fulcrum pin 204 is separated from the fulcrum pin 204 by a predetermined distance in the axial direction of the reader 2.
Six detection shafts 208 are inserted through the winch base 200 and the support plate 202.

The load cell 206 is connected to the electronic control circuit 150 as in the above-described embodiment, and the load detected by the load cell 206 is converted into an electric signal and output. The relationship between the detected load P and the wire tension F is expressed by the following equation. F = a × P / (m−r) where a is the axial distance between the support shaft 204 and the detection shaft 208, m is the distance between the support shaft 204 and the rotation center of the drum 58, and r is the wires 48, 50. And the center of rotation of the drum 58. In this way, the reaction force due to the tension F of the wires 48 and 50 can be similarly detected even if the load cell 206 detects the load P as the load P.

Although the working table winch 56 is used as an example of the drive mechanism in this embodiment, the present invention is not limited to this.
It is also possible to implement a structure in which the work table 60 is moved up and down by meshing the pinion gear attached to the rotary shaft of the hydraulic motor provided on the moving table 42 with the rack laid along the axial direction of. In this case, the reaction force applied to the hydraulic motor may be detected by the fulcrum pin and the detection axis of the load cell, as in the second embodiment described above.

The present invention is not limited to the embodiments as described above, and can be carried out in various modes without departing from the scope of the present invention.

[0051]

As described in detail above, the workbench lifting device for pile construction machine according to the present invention stops the lifting and lowering by the drive mechanism according to the load detected by the load detecting means, so that the drive mechanism and the workbench are stopped. Since the breakage of the is prevented, the safety is improved. Further, in the case of notifying an overload or a lowering abnormality, it is possible to promptly know the cause of the drive mechanism being stopped.

[Brief description of drawings]

FIG. 1 is an electric / hydraulic circuit diagram of a work platform lifting device for a pile construction machine as one embodiment of the present invention.

FIG. 2 is a front view of a pile construction machine equipped with a work platform lifting device for a pile construction machine according to the present embodiment.

FIG. 3 is a side view of a pile construction machine provided with a work platform lifting device for a pile construction machine according to the present embodiment.

FIG. 4 is an enlarged perspective view of the workbench of the present embodiment.

FIG. 5 is an enlarged cross-sectional view of the detection sheave of this embodiment.

FIG. 6 is a flowchart showing an example of control processing performed by the electronic control circuit of this embodiment.

FIG. 7 is an enlarged side view of a work table winch according to a second embodiment.

8 is an AA enlarged cross-sectional view of FIG.

[Explanation of symbols]

 1 ... Pile construction machine main body 2 ... Leader 8, 10 ... First guide rail 12 ... Auger drive mechanism 16 ... Auger drill 18 ... Pushing mechanism 19 ... Piles 36, 38 ... Second guide rail 42 ... Moving stand 46 ... Boarding stand 56 ... Workbench winch 60 ... Workbench 102a, 102b ... Detecting sheaves 114,116,206 ... Load cell 150 ... Electronic control circuit

Claims (4)

[Claims] 1. A work platform lifting device for a pile construction machine, which lifts and lowers a work platform movably supported along a guide rail provided on an upright leader by a load on the drive mechanism. A work platform elevating device for a pile construction machine, comprising: load detecting means for detecting; and control means for stopping the elevating and lowering by the drive mechanism according to the load detected by the load detecting means. 2. The pile construction machine according to claim 1, wherein the drive mechanism is a winch in which the workbench is suspended by a wire, and the load detection means detects a load according to a tension of the wire. Work platform lifting device. 3. The workbench lifting device for a pile construction machine according to claim 1, wherein the load detection means detects a reaction force applied to the drive mechanism. 4. The control means reports an overload when the load detected by the load detection means is a predetermined value or more, and reports a descent abnormality when the load is a predetermined value or less. The workbench lifting device for a pile construction machine according to any one of claims 1 to 3.