JPH02204595A - Tension giving method to excavator position detecting wire and its equipment - Google Patents

Abstract

PURPOSE:To improve controlling accuracy by operating an unwinding/winding device of a detecting wire every time a tension giving device reaches an upper limit position or a lower limit position in order to give a prescribed tension to the detecting wire, corresponding to the weight of the tension giving device. CONSTITUTION:Guide rails 9 and 9 are provided on both right and left sides of a frame 1, thereby constituting a tension giving device 4 in such a manner that it can go up and down. When the device 4 hits an upper limit switch 11 or a lower limit switch 12, a wire unwinding/winding device 3 is operated to draw out a detecting wire 2. Next, as the excavation work progresses, the device 4 goes up to operate the switch 11, the device 3 draws out the detecting wire 2 faster than the excavating speed. When the device 4 goes down to operate the switch 12, the device 3 stops. Thus, prescribed tension is given to the wire 2, corresponding to the weight of the device 4, and X-Y displacements of the wire 2 are measured under this condition. Accordingly, accuracy of posture control can be enhanced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] When excavating a trench for constructing a continuous underground wall, etc., the present invention connects it to an excavator to ensure the verticality of the trench. This invention relates to a method and device for always applying a constant tension to a so-called position detection wire that detects the front, rear, left, right, twist, etc. positions of a machine.

[Conventional technology]

Conventionally, when using an excavator to excavate a trench for construction of a continuous underground wall, etc., a detection wire for detecting the excavation position of the excavator was placed vertically between the excavator and a tower-shaped pedestal set on the ground. At the same time, an X is attached to this vertically stretched detection wire.
-In conjunction with the Y displacement meter, detects the displacement of the excavator that occurs during excavation, that is, deviations such as front, rear, left, right, twist, etc.
Based on the detected data, the stroke of the adjustable arms installed on the front, rear, left, and right sides of the excavator is activated to control the attitude of the excavator so that it can always excavate vertical construction trenches. Devices equipped with such devices are known.

[Problem to be solved by the invention]

Incidentally, in order to perform highly accurate posture control, it is necessary for the detection wire that detects the displacement of the excavator, such as front, rear, left, right, torsion, etc., that is, the excavation position, to be always stretched with a constant tension.

Therefore, conventionally, a torque motor is associated with a detection wire unwinding and winding device provided on the mount side, and the torque motor always applies a constant tension to the detection wire. However, this method using a torque motor has the following problems.

(1) First, the torque generated by the torque motor for applying tension to the detection wire is always constant in principle. In contrast, the length of the detection wire increases depending on the excavation work of the excavator. Therefore, there is no problem if the detection wire is always maintained at a constant length, but if the length of the detection wire changes as the excavation progresses, that is, the excavator goes deep underground and the detection wire becomes longer. If this occurs, the tension applied to that detection wire will be relatively weak.

Especially in the case of deep excavation, where the excavation depth is more than 100 meters, the X-Y displacement meter is necessary because the excavation trench is affected by the flow of muddy water containing stabilizing liquid that fills the excavation trench.

An error occurs in the amount of horizontal displacement of the detection wire measured.

As a result, there is a problem in that the accurate inclination of the excavator cannot be detected, and the attitude of the excavator cannot be properly controlled. In other words, there was a drawback that highly accurate attitude control was not possible.

Therefore, in the case of deep excavation, attempts have been made to prevent this deviation by using a large torque motor and increasing the tension applied to the detection wire to eliminate the influence from muddy water flow and the like.

However, increasing the size of the torque motor and introducing a torque control system not only complicates the device, but also poses problems in terms of reliability and economy, and the problem has not yet been adequately resolved.

(2) Next, when tension is applied by a torque motor, the motion of the torque motor is not completely static and constant.

Therefore, there is some discontinuity when the detection wire is unwound, and the detection wire swings in the vertical direction, causing an error in the detected value by the X-Y displacement meter. There was a problem that the posture could not be controlled.

(3) Furthermore, since the excavation speed of an excavator to which the detection wire is connected is affected by the geological conditions of the ground being excavated, it may suddenly descend or rise during excavation work. In other words, the excavation speed may change rapidly.

If the torque motor can respond appropriately to this change, there will be no problem, but if there is a delay in responding, abnormal tension may be applied to the detection wire, causing it to break or become loose, and in some cases. There was also the problem that the winding drum could cause problems.

In any case, the conventional method of applying tension to the detection wire using a torque motor has problems in terms of reliability and economic efficiency in properly controlling the attitude of the excavator.

It is an object of the present invention to provide a method and apparatus for constantly applying appropriate tension to a detection wire in order to detect the position of an excavator, which solves these problems of the prior art.

[Means to solve the problem]

The method and apparatus adopted by the present invention as means for achieving the above object are as follows.

First, a detection wire unwinding device is installed on the ground frame, and the detection wire is vertically connected to the excavator from this unwinding and winding device, and the amount of horizontal displacement of the vertically connected detection wire is expressed as In a trench excavator for constructing continuous underground walls, etc., in which the excavation posture of the excavator is controlled based on the detected data, the detection wire from the unwinding and winding device is connected to the above-ground mount. It is connected to the excavator through the sheaves provided on the left and right sides of the upper part, and a counterweight type tensioning device is suspended from the detection wire between the left and right sheaves, and this suspended tensioning device
When the wire rises to a preset upper limit position, the detection wire unwinding device is activated to unwind the detection wire at a speed faster than the excavation speed of the excavator, and conversely, when it descends to the lower limit position, the winding By stopping the operation of the unwinding and winding device, and then repeatedly operating and stopping the unwinding and winding device for the detection wire in the manner described above, a constant tension is always applied to the detection wire.

Further, as a means for repeatedly operating and stopping the unwinding and winding device for the detection wire, lifting guide rails of a tensioning device are provided on both sides of the above-mentioned ground frame, and the tensioning device is provided at the upper and lower portions of the lifting guide rail. An upper limit switch and a lower limit switch are respectively provided, which are turned on and off when the detection wire is raised and lowered, and these upper and lower limit switches are turned on and off to turn on and off the detection wire unwinding and winding device.
It is characterized in that it functions as an OFF control switch.

That is, the apparatus has a configuration in which ON-OFF control switches for the detection wire unwinding and winding device are provided at the upper and lower portions of the lifting guide rail of the tension applying device.

Further, the tension applying device is characterized in that weights divided into a plurality of pieces are loaded to form a tension applying device whose weight can be freely adjusted.

[Effect]

As explained above, the method and device for applying tension to a detection wire according to the present invention is a tension application method using a counterweight, so that the tension applied to the detection wire is always maintained constant according to its weight. .

To explain the operation in this point more specifically, first, when the excavation work is started and the excavator descends, the tension applying device suspended from the detection wire relatively rises. During this upward movement, the detection wire is maintained at a constant tension by the weight of the tensioning device.

When the tension applying device rises, that is, the excavation work progresses and the tension applying device reaches the set upper limit position, the upper limit switch is activated, the detection wire unwinding device is activated, and the detection wire is excavated. Unwind at a speed faster than the excavation speed of the machine.

The tensioning device will then be relatively lowered due to its weight. - When the tensioning device is lowered to its lower limit position, the lower limit switch is actuated, which results in the detection wire unwinding and winding device being deactivated. Thereafter, as the excavation work progresses, the tension applying device repeats up and down operations, but during this time a constant tension is always applied to the detection wire.

In other words, the detection wire is held at a predetermined tension without loosening or shaking in the vertical direction. As a result, the measured values by the X-Y displacement meter do not deviate, and the excavator can always be controlled in its proper attitude, allowing vertical construction trenches to be excavated.

In addition, the weight of the tensioning device is adjustable, so if the excavation depth is 100 meters or more and there is a risk of the influence of stabilizing liquid, etc., in other words, if the length of the detection wire becomes long, the length The weight can be adjusted to apply appropriate tension depending on the situation.

Note that when the excavation work is finished and the excavator is pulled up, the tension of the detection wire is not a problem.

Therefore, contrary to the case of the excavation work, the lower limit switch may be switched so that when the tension applying device is lowered to the lower limit position, the lower limit switch is activated to perform the winding work of the detection wire.

〔Example〕

Furthermore, the configuration of the method and apparatus of the present invention will be specifically explained based on the embodiments shown in the drawings.

First, Fig. 1 shows the main parts of the apparatus for carrying out the method of the present invention, in which a pedestal 1 is installed above ground in a construction trench A for constructing a continuous underground wall, and a detection wire 2 is unwound onto the pedestal 1. The winding device 3 and a tensioning device 4 in the form of a counterweight for applying appropriate tension to the detection wire 2 are shown in a suspended state. In the embodiment, as shown in this figure, a general winch is used as the unwinding and winding device 3 for the detection wire 2. The detection wire 2 from this winch is suspended vertically through a reversing sheave 5 and a top sheave 6 provided on both left and right sides of the upper part of the pedestal 1, and its terminal is connected to an excavator (not shown). Next, a tension applying device 4 in the form of a counterweight is suspended between the reversing sheave 5 and the top sheave 6 via a hanging sheave 7.

The tension applying device 4 is composed of a weight mounting frame 4b consisting of a box-shaped frame 4a, and a plurality of weights 8 divided into a certain weight are mounted in a stacked manner on this weight mounting frame 4b. The weight can be adjusted as appropriate.

Furthermore, guide rails 9 and 9 for raising and lowering the tension applying device 4 are provided on both left and right sides of the gantry 1, and the tension applying device 4 is configured to be raised and lowered via guide rollers 10 and 10. An upper limit switch 11 is provided at the upper part of the guide rail 9, and a lower limit switch 12 is provided at the lower part of the guide rail 9. When the tension applying device 4 rises and reaches the upper limit switch 11 position, the upper limit switch 11 activates the detection wire. The unwinding and winding device 3, that is, the winch is operated to allow the detection wire 2 to be fed out at a speed faster than the excavation speed of the excavator.

Conversely, when the tension applying device 4 is lowered to the lower limit 7) switch 12 position, the winch operation is stopped.

In the embodiment, the upper limit switch 11
For safety purposes, an upper alarm limit switch Ila and a lower alarm limit switch 12a are provided above and below the lower limit switch 12, respectively, to ensure the safety of the device.

Furthermore, a cushioning material 13 is disposed at the bottom of the pedestal 1 to function as a shock absorber to ensure safety even if the tensioning device 4 were to fall.

Next, the operating state will be explained with reference to FIGS. 2 and 4.

First, FIG. 2 shows the position of the tension applying device 4 immediately after the start of excavation work. As the excavation work progresses, this tensioning device 4
will rise further. When the excavator rises to the height of the upper limit switch 11 shown in FIG. 3, the upper limit switch 11 is activated and the detection wire 2 is fed out at a speed faster than the excavation speed of the excavator. As a result, the tensioning device 4 is relatively lowered. FIG. 4 shows the tensioning device 4 lowered to the lower limit switch 12 position.

When the tension applying device 4 comes to this position, the lower limit switch 12 is activated, and the operation of the winch that was letting out the detection wire 2 is stopped. When the winch stops, the tension applying device 4 is raised again in accordance with the excavation work.

Thereafter, as the excavation work progresses, the tensioning device repeatedly moves up and down, and during this time a constant tension is always applied to the detection wire 2 according to the weight of the tensioning device 4. As a result, there is no error, that is, accuracy is maintained. High detection wire 2 X-Y
Measures displacement and ensures proper attitude control of the excavator.

In addition, when excavating at a deep depth of 100 meters or more, the length of the detection wire must be determined in advance, and a suitable tension should be applied to the detection wire 2 to eliminate the influence of stabilizing liquid in the excavation trench. The weight in the tension applying device 4 is adjusted. (See Figure 5) [Effects of the Invention] As described above, the present invention uses a counterweight method to apply tension to the detection wire, so the following effects are achieved compared to the conventional application method using a torque motor. be done.

[1] The weight of the weights can be adjusted freely, that is, by increasing or decreasing the number of weights,
Optimal tension can always be applied to the detection wire.

As a result, highly accurate displacement measurement of the detection wire is maintained, making it possible to detect the exact position of the excavator, allowing for proper attitude control of the excavator, and excavating deep construction trenches such as vertical continuous underground walls. (2) Since it is a counterweight type, the tension applying device has a simple configuration and is much more economical than a torque motor.

(3) The lifting and lowering operation of the tension applying device is completely synchronized with the movement of the excavator, so a constant tension is always applied to the detection wire, there is no error in the displacement measurement results of the detection wire, and the attitude of the excavator is properly controlled. , ensuring highly accurate excavation of construction trenches.

(4) There are no problems such as cutting of the detection wire or irregular winding of the wire drum, which occur when a torque motor is used. Therefore, reliability, workability, and maintainability are improved.

[Brief explanation of the drawing]

FIG. 1 is a mechanical diagram showing the main parts of an apparatus for carrying out the method of the present invention. Figure 2 is a state diagram in which the tension applying device is in ascending operation with the start of excavation work, Figure 3 is a state diagram in which the tension applying device is raised to the upper limit switch position,
Figure 4 shows that when the upper limit switch is activated (ON), the sensing wire unwinding device is activated to unwind the sensing wire, and the tension applying device is activated (ON) to unwind the sensing wire.
) and the detection wire has stopped feeding out. Figure 5 shows the state when the detection wire has stopped feeding out to the position shown in Figure 5. When the excavation depth is deep and the length of the detection wire becomes long, the weight of the tensioning device is adjusted. FIG. 1... Frame 2... Detection wire...
Detection wire unwinding and winding device (winch)...Tensioning device 5...Reversing sheave...Top sheave 7...Hanging sheave...Weight
9... Guide rail 0... Guide roller... Upper limit switch 2... Lower limit switch Figure 5

Claims (2)

[Claims] (1) A detection wire is stretched vertically between the excavator that excavates a trench for constructing a continuous underground wall, etc. and the above-ground mount, and the X-Y displacement of this vertically stretched detection wire is detected. In an excavator for continuous underground walls, etc., in which the attitude of the excavator is controlled based on the detection data, the detection wire is connected to the excavator via two sheaves from an unwinding and winding device installed on a ground mount. A counterweight-type tensioning device is suspended between these two sheaves, and when this tensioning device rises with excavation work and reaches the upper limit position, the detection wire is unwound. The winding device is operated to unwind the detection wire at a speed faster than the excavation speed, and when the lower limit position is reached, the operation of the winding device for unwinding the detection wire is stopped, and the above operation is repeated to unwind the detection wire. A method for applying tension to a position detection wire of an excavator, characterized in that a constant tension is always applied based on the weight of a tension applying device. (2) A sheave is installed on the left and right sides of the upper part of the above-ground mount, and the detection wire is connected to the excavator from the unwinding and winding device via the left and right sheaves, and a weight-adjustable tensioning device loaded with weights divided into multiple pieces. is suspended from the detection wire between the left and right sheaves, and an elevating guide rail for this tensioning device is provided on the above ground frame, and unwinding and winding devices for the detecting wire are provided at the upper and lower portions of the elevating guide rail. A tension applying device for a position detection wire of an excavator, characterized in that a switch for ON-OFF control is provided.