JP2002220987A - Lifter for earth auger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lifter for an earth auger, in which the relative distance between the extremity of a screw and the top of a casing can be taken large discretionally. SOLUTION: In the earth auger, an outer spindle driving unit 5 driving a cylindrical outer spindle and a center spindle driving unit 4 driving a center spindle concentrically arranged inside the cylindrical outer spindle are hung on a leader 2 via a winch provided on a base machine 1, so that the driving units can be lifted up and down. The outer spindle driving unit 5 and the center spindle driving unit 4 are separately hung via the hydraulic drive winch, and a distance sensor 15 is arranged on the outer spindle driving unit 5 or the center spindle driving unit 4, the distance sensor measuring the relative distance between the outer spindle driving unit 5 and the center spindle driving unit 4. Upon winching off the driving units, when the relative distance L becomes larger than a set distance L0, the rotating speed of a winch drum 38 for hanging the outer driving unit 5 is reduced, and when the relative distance L becomes smaller than the set distance L0, the rotating speed of a winch drum 8 for hanging the center driving unit 4 is reduced, so that the relative distance L is kept in the set distance L0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a reader with a drive device for driving two axes, a cylindrical outer shaft such as a casing and a screw and a center shaft disposed concentrically inside the shaft, so that the reader can move up and down. The present invention relates to a lifting device for an earth auger.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
Guide rail 2 vertically attached to the guide 2
The center shaft driving device 4 having the screw 6 attached to the a and the outer shaft driving device 5 having the casing 7 mounted thereon are engaged with each other so as to be able to move up and down, and are drawn from the winch drum 8 provided in the base machine 1 via the top sheave 10. An earth auger suspended by a wire rope 11 is known.

[0003] This earth auger is excavated by rotating the screw 6 by the center shaft driving device 4 and rotating the casing 7 in the opposite direction by the outer shaft driving device 5. It is possible to change the rotation speed and, for example, on a hard ground
The tip of the screw 6 precedes the tip of the screw 6 so that the tip of the screw 6 can protrude from the tip of the casing 7 on soft ground. In FIG. 7, reference numeral 12 denotes a hanging sheave.

The means for changing the relative distance between the distal end of the screw 6 and the distal end of the casing 7 includes, for example, as shown in FIG. 8, a center shaft driving device 4 to which the screw 6 is attached and an outer shaft driving device 5 to which the casing 7 is attached. Are connected by a cylinder 9, and the cylinder 9 is expanded and contracted.

[0005]

As described above, in the case where the center shaft driving device and the outer shaft driving device are connected by the cylinder, the relative distance between the tip of the screw and the tip of the casing is kept constant because the relative distance is mechanically maintained. Can be However, at the construction site, there is a case where it is desired to make the relative distance between the tip of the screw and the tip of the casing larger than the maximum stroke of the cylinder. It should be noted that increasing the stroke of the cylinder has a limitation in installation space and increases the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an earth auger elevating device which can take an arbitrarily large relative distance between a tip of a screw and a tip of a casing.

[0007]

In order to achieve the above object, the present invention employs the following means. That is, an outer shaft driving device that drives a cylindrical outer shaft and a center shaft driving device that is located above the outer shaft driving device and that drives a center shaft concentrically disposed inside the outer shaft driving device are moved up and down to a reader by a winch provided in a base machine. In the lifting device of the earth auger suspended as possible, the outer shaft driving device and the center shaft driving device are respectively suspended by hydraulically driven winches, and a distance sensor for measuring a relative distance between the outer shaft driving device and the center shaft driving device is provided. Provided on the shaft drive or the center shaft drive,
When the outer shaft drive device and the center shaft drive device are lowered, the rotation of the winch drum that suspends the outer shaft drive device is reduced when the relative distance is larger than the set distance, and when the relative distance is smaller, the winch drum that suspends the center shaft drive device. Is characterized in that the rotation is reduced to a set distance.

Here, the earth auger refers to a foundation construction machine that excavates by rotating a screw and a casing on a cylindrical shaft and rotating a casing and a pile with a cylindrical shaft to improve the ground. In addition, the hydraulic drive winch means a winch drum rotated by a hydraulic motor,
The speed of hoisting and lowering can be changed.

For shifting up and down, the hydraulic pump or the hydraulic motor may be of a variable discharge type, or the hydraulic pump and the hydraulic motor may be of a constant discharge type and the supply amount to the hydraulic motor may be changed by a flow control valve. Various means can be adopted, and the present invention is not particularly limited.

As the distance sensor for measuring the relative distance between the outer shaft driving device and the center shaft driving device, various types such as ultrasonic waves and lasers can be used, but a cable is arranged between the outer shaft driving device and the center shaft driving device. A sensor that outputs an analog or digital electric signal according to the amount of cable pulled out (referred to as a cable lead-out type position sensor) is small in size and easy to mount.

The distance sensor is provided in either the outer shaft driving device or the center shaft driving device, but naturally includes a distance sensor attached to a member attached to the outer shaft driving device or the center shaft driving device and moving integrally therewith. When the work is performed with the relative distance between the outer shaft drive device and the center shaft drive device being constant, an optimum value is set (set distance) in advance depending on soil properties and the like.

When the winch is lowered, the rotation of the winch drum of the outer shaft drive is reduced when the relative distance is larger than the set distance, and the rotation of the winch drum of the center drive is reduced when the relative distance is smaller. Maintain the set distance. In many cases, the hydraulic motor of the winch is supplied with the maximum flow rate in many cases. Therefore, it is not preferable to control the speed of the winch drum to increase the rotation of the winch drum in order to achieve the set distance.

When it is desired to keep the relative distance constant during winding, when the relative distance is larger than the set distance during winding, the rotation of the winch drum of the center shaft driving device is decelerated. What is necessary is just to add the control which reduces the rotation of the winch drum of an apparatus.

In general, a hydraulically driven winch performs smooth initial movement, so that a main switching valve for switching hydraulic oil to a hydraulic motor is not an electromagnetic switching valve but a control hydraulic pressure is sent to the main switching valve by operating a remote control valve. In this case, when the work is performed while keeping the relative distance between the outer shaft drive device and the center shaft drive device constant, as described in claim 2, the two main switching systems in which the control hydraulic pressure is sent are provided. It is desirable that the hoisting side ports and the lowering side ports of the valves be communicated with each other so that when one remote control valve is operated, the other main switching valve is also automatically switched. Since only one lever needs to be operated, the operability is significantly improved, and there is no fear of erroneous operation.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an earth auger elevating device according to the present invention will be described below with reference to the drawings. The overall configuration of the earth auger is the same as that shown in the above-described conventional case (FIG. 7), and thus description thereof will be omitted.

FIG. 1 is a front view showing the structure of an embodiment of an earth auger elevating device. A center shaft driving device 4 for driving a screw 6 is engaged with a guide rail 2a of a reader 2 and provided on a base machine 1. An outer shaft driving device 5 which is suspended by a wire rope 11 drawn from a winch drum 8 through a top sheave 10 and drives the casing 7 is not shown, but is separated from the center shaft driving device 4 by a leader. 2
, And is suspended by a wire rope routed through another top winch drum 38 from another winch drum 38 provided on the base machine 1. In addition, 12 and 16 are hanging sheaves.

Therefore, the center shaft driving device 4 and the outer shaft driving device 5 can be moved up and down separately. A distance sensor 15 for detecting the distance between the center shaft driving device 4 and the outer shaft driving device 5 is provided. This distance sensor 15 is called a cable pull-out type position sensor,
The sensor main body is attached to the outer shaft driving device 5, and the cable is pulled out from the sensor main body and locked to the center shaft driving device 4, and when the relative distance between the center shaft driving device 4 and the outer shaft driving device 5 changes, the sensing device is reduced in the cable pull-out amount. It outputs a proportional signal electrically, has a spring for rewinding, and tension is always applied to the cable.

FIG. 2 shows a hydraulic motor 25 for driving the winch drum 8 for suspending the center shaft drive 4 and the hydraulic motor 26 for driving the winch drum 38 for suspending the outer shaft drive 5 provided on the base machine 1. This shows a hydraulic circuit, in which a hydraulic motor 25 is connected to a variable discharge hydraulic pump 21 by a main switching valve 2.
3, and the hydraulic motor 26 is connected to the variable discharge type hydraulic pump 22 via the main switching valve 24.

The main switching valve 23 and the main switching valve 24 are switched by the pressure oil of a separately provided control pump 31, and remote control valves 27 and 28 are provided in the circuit. The hoisting side of the remote control valve 27 communicates with the hoisting side port 23a of the main switching valve 23 via the solenoid valve V1, and the lowering side of the remote control valve 27 communicates with the hoisting side port 23b of the main switching valve 23 and the solenoid valve V2. Is communicated through.

The hoisting side of the remote control valve 28 communicates with the hoisting side port 24a of the main switching valve 24 via the solenoid valve V3, and the lowering side of the remote control valve 28 is the lowering side port of the main switching valve 24. 24b and the solenoid valve V4. Further, the winding port 23a of the main switching valve 23 and the winding port 24a of the main switching valve 24
1, the lowering-side port 23b of the main switching valve 23 and the lowering-side port 24b of the main switching valve 24 communicate with each other through a flow path 42, a solenoid valve V5 in the flow path 41, and an electromagnetic valve V5 in the flow path 42. Valve V
6 are provided.

Pressure switches PS1, PS are provided in flow paths on the winding side and the lowering side of the remote control valves 27, 28, respectively.
2, PS3, and PS4. The pressure oil of the control pump 31 is further connected to electromagnetic pressure reducing valves 29 and 30 for controlling the discharge amounts of the hydraulic pumps 21 and 22, respectively.

The solenoid valves V1, V2, V3, V4, V
5 and V6 open and close a flow path of a control circuit for switching the main switching valves 23 and 24. As shown in FIG.
The solenoids 1 to V6 are provided to the controller 33 by the changeover switches 34a, 34b, 34c, 34d, 34e,
34f, the controller 33 includes pressure switches PS1, PS2, PS3, and PS4 and a synchronous switch 3
2 is connected to a power supply 40.

Further, as shown in FIG. 4, the controller 33 is connected to a power supply via the distance sensor 15,
Wired to the electromagnetic pressure reducing valves 29 and 30, respectively. Next, the operation of the earth auger elevating device configured as described above will be described with reference to the flowchart shown in FIG.

Normal excavation work (when the synchronous switch 32 is
F state), the solenoids of the pressure switches PS1 to PS4 and the solenoid valves V1 to V6 are not energized, the solenoid valves V1, V2, V3, and V4 are open and the solenoid valves V
5, V6 are in a closed state (see FIGS. 2 and 3). In this state, the remote control valves 27 and 28 are individually operated to raise and lower the center shaft driving device 4 and the outer shaft driving device 5.

When working with the center shaft driving device 4 and the outer shaft driving device 5 synchronized with each other at a fixed distance, first, one of the remote control valves 27 and 28 is operated to the hoisting side or the lowering side to drive the center shaft driving device. The device 4 and the outer shaft driving device 5 are positioned at a target relative distance. Then, the synchronization switch 32 is pressed (step 100). The relative distance at this time is measured by the distance sensor 15 and stored in the controller 33 as the set distance L0 (step 110).

Next, one of the remote control valves 27 and 28 is operated in a desired direction (winding or lowering) (step 120). As a result, the pressure oil of the control pump 31 flows to the control flow path on the operated side, the pressure increases, and the one corresponding to the pressure switches PS1 to PS4 is turned on.
(Step 130, Step 132, Step 1
34, step 136). That is, the controller 33
Then, when the pressure switch PS1 is turned on, the center shaft driving device 4 is in a winding state, when the pressure switch PS2 is turned on, the center shaft driving device 4 is in a lowered state, and when the pressure switch PS3 is turned on, the center shaft driving device 4 is in a winding state. When the shaft driving device 5 is in the winding state and the pressure switch PS4 is turned on, it is determined that the outer shaft driving device 5 is in the lowering state.

When the pressure switch PS1 or PS2 is turned on (when the remote control valve 27 is operated to raise or lower), the controller 33 sets
The changeover switches 34c, 34d, 34e, and 34f are turned on, the solenoids of the solenoid valves V3, V4, V5, and V6 are energized, the solenoid valves V1, V2, V5, and V6 are opened, and the solenoid valves V3 and V4 are closed. To Also, pressure switch PS
3 or PS4 is turned on (remote control valve 2
8 is operated to raise or lower), the change-over switches 34a, 34b, 34e, 34f are turned on, and the solenoids of the solenoid valves V1, V2, V5, V6 are energized, and the solenoid valves V3, V4, V5, V6 is opened and the solenoid valve V
1, V2 is closed.

Accordingly, the control flow path 41 and the flow path 42 are opened, and the main switching valve 23 and the main switching valve 24 are switched in conjunction with each other. That is, when the center shaft driving device 4 or the outer shaft driving device 5 is in the winding state (the pressure switch PS1 or the pressure switch PS3 is ON), the outer shaft driving device 5 or the center shaft driving device 4 is also in the winding state (Step 131, Step 135), when the center shaft driving device 4 or the outer shaft driving device 5 is in the lowered state (the pressure switch PS2 or the pressure switch PS4 is ON), the outer shaft driving device 5 or the center shaft driving device 4 is also in the lowering state (135). Step 133, Step 137).

When the synchronous switch 32 is ON, the relative distance L between the center shaft driving device 4 and the outer shaft driving device 5 is measured by the distance sensor 15, and the information is sent to the controller 33 (step 140). The controller 33 compares the current relative distance with the set distance L0 (step 15).
0) If the relative distance L is larger than the set distance L0, the process proceeds to step 160.

In step 160, the pressure switch P
When S1 or the pressure switch PS3 is ON (at the time of lifting), the electromagnetic pressure reducing valve 29 is energized to reduce the discharge amount of the hydraulic pump 21, and when the pressure switch PS2 or the pressure switch PS4 is ON (at the time of lowering). Is the electromagnetic pressure reducing valve 3
By applying 0, the discharge amount of the hydraulic pump 22 is reduced.

On the other hand, if the relative distance L is smaller than the set distance L0, the routine proceeds to step 180, where the pressure switch PS1
Alternatively, when the pressure switch PS3 is ON (at the time of hoisting), the electromagnetic pressure reducing valve 30 is energized to reduce the discharge amount of the hydraulic pump 22, and when the pressure switch PS2 or the pressure switch PS4 is ON (at the time of hoisting), Electromagnetic pressure reducing valve 29
And the discharge amount of the hydraulic pump 21 is reduced.

This operation is performed until the relative distance L becomes equal to the set distance L0 (or is within the set range).
Then, when the remote control valves 27 and 28 are returned to the neutral positions, the process is terminated (step 210). In the above embodiment, the operation of the remote control valves 27 and 28 has been described as being detected by the pressure switches PS1 to PS4. However, the limit switches are engaged with the levers of the remote control valves 27 and 28 to provide an operating state. You may make it detect.

When the winch capacity is relatively small, the hydraulic circuit shown in FIG. 2 can be configured as shown in FIG. That is, the winch hydraulic motors 25 and 26 that respectively suspend the center shaft driving device 4 and the outer shaft driving device 5 are:
Switches connected to the variable discharge type hydraulic pumps 21 and 22 via electromagnetic switching valves 35 and 36 to individually excite the solenoids 35a and 35b of the electromagnetic switching valve 35 and the solenoids 36a and 36b of the electromagnetic switching valve 36. Are separately provided (not shown).

When any one of the switches is turned on while the synchronous switch 32 is turned on, the other solenoid-operated directional control valve is turned on based on the power supply information. For example, when the solenoid 35a is energized, the solenoid 36a is energized, and when the solenoid 36b is energized, the solenoid 35b is energized. The operation of the control for keeping the relative distance constant is the same as in the flowchart shown in FIG.

[0035]

As described above, in the earth auger lifting and lowering device of the present invention, the outer shaft driving device and the center shaft driving device are suspended by hydraulically driven winches, respectively. A winch drum for suspending the outer shaft drive when the relative distance is greater than a set distance when the outer shaft drive and the center shaft drive are provided with a distance sensor for measuring the distance in the outer shaft drive or the center shaft drive; The rotation of the winch drum that suspends the center shaft drive was reduced to a set distance when the rotation was small, so that the relative distance between the tip of the screw and the tip of the casing was constant according to the soil quality. Work can be performed, and the relative distance can be arbitrarily increased as compared with the conventional case in which the outer shaft drive device and the center shaft drive device are connected by a cylinder, thereby expanding the range of work that can be performed.

Each hydraulic motor for driving both winch drums is connected to a hydraulic pump via a main switching valve that switches with control hydraulic pressure, and the control hydraulic pressure to the hoisting port or the lowering port of the main switching valve is It is configured to switch by operating the remote control valve, and when working with the relative distance between the outer shaft drive device and the center shaft drive device constant, the winding side port and the lowering side port of both main switching valves are communicated, and If the other main switching valve is automatically switched when the remote control valve is operated (claim 2), the operation is not only simple, but there is no fear of erroneous operation.

[Brief description of the drawings]

FIG. 1 is a front view showing the configuration of an embodiment of an earth auger elevating device according to the present invention.

FIG. 2 is a hydraulic circuit diagram of the same.

FIG. 3 is a wiring connection diagram of solenoid valves V1 to V6 of FIG. 2;

FIG. 4 is a circuit diagram of a discharge amount control circuit of the hydraulic pump.

FIG. 5 is a hydraulic circuit diagram showing another embodiment of FIG. 2;

FIG. 6 is a flowchart for controlling the relative distance between the center shaft driving device and the outer shaft driving device to be constant.

FIG. 7 is a side view showing an entire conventional earth auger.

FIG. 8 is a front view of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base machine 1a ... Bracket 2 ... Leader 2a ... Guide rail 3 ... Back stay 4 ... Middle shaft drive 5 ... Outer shaft drive 6 ... Screw 7 ... Casing 8 ... Winch drum 9 ... Cylinder 10 ... Top sheave 11 ... Wire rope DESCRIPTION OF SYMBOLS 12 ... Hanging sheave 15 ... Distance sensor 16 ... Hanging sheave 21, 22 ... Hydraulic pump 23 ... Main switching valve 23a ... Hoisting side port 23b ... Lowering side port 24 ... Main switching valve 24a ... Hoisting side port 24b ... Lowering side port 25, 26 hydraulic motor 27, 28 remote control valve 29, 30 electromagnetic pressure reducing valve 31 control pump 32 synchronous switch 33 controller 34a, 34b, 34c selector switch 34d, 34e, 34f selector switch 35, 36 ... electromagnetic switching valve 38 ... winch drum 40 ... power supply 41, 4 2 ... Flow path PS1, PS2, PS3, PS4 ... Pressure switch V1, V2, V3, V4, V5, V6 ... Solenoid valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D029 CC01 3H089 AA34 AA71 BB15 CC08 CC12 DA03 DB32 EE22 EE36 FF03 GG02 JJ01

Claims (2)

[Claims] 1. A winch having a base machine having an outer shaft driving device for driving a cylindrical outer shaft and a center shaft driving device for driving a center shaft located above and concentrically disposed inside the outer shaft driving device. In the lifting device of the earth auger suspended so as to be able to ascend and descend from the reader, the outer shaft driving device and the center shaft driving device are respectively suspended by hydraulically driven winches, and a distance for measuring a relative distance between the outer shaft driving device and the center shaft driving device. A sensor is provided on the outer shaft drive device or the center shaft drive device, and when the outer shaft drive device and the center shaft drive device are lowered, if the relative distance is larger than the set distance, the rotation of the winch drum that suspends the outer shaft drive device is reduced. A lifting device for an earth auger, wherein when the size is small, the rotation of a winch drum for suspending the center shaft driving device is reduced to a set distance. 2. A hydraulic pump for driving both winch drums is connected to a hydraulic pump via a main switching valve which is switched by control oil pressure, and a control hydraulic pressure is supplied to a hoisting port or a lowering port of the main switching valve. Is configured to switch by the operation of the remote control valve, when working with the relative distance between the outer shaft drive device and the center shaft drive device constant, let the hoisting side ports and the lowering side ports of both main switching valves communicate with each other, 2. The earth auger lifting and lowering device according to claim 1, wherein when one of the remote control valves is operated, the other main switching valve is also automatically switched.