JP3441946B2 - Excavation control method of casing driver, excavation control device, and method of measuring self-sinking load - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding means for holding a casing pipe, a thrust cylinder capable of supporting and holding the holding means, a motor for rotationally driving the holding means, and a cylinder side pressure of the thrust cylinder. TECHNICAL FIELD The present invention relates to an excavation control method, an excavation control device, and a self-sinking load measuring method for a casing driver having an adjustable relief valve.

[0002]

2. Description of the Related Art A casing driver has been generally known as a device for press-fitting and withdrawing casing pipes such as large-diameter steel pipe piles and steel pipes used for civil engineering and construction work. Also, some casing pipes have a cutter bit attached to the tip. When pressing such a casing pipe with a casing driver,
The casing driver grips the casing pipe and pushes it while rotating it to excavate the ground. The present invention improves technology useful for excavation control and its control when excavating the ground in such casing pipe press-fitting process,
Or, it is something to be created. Therefore, an example of a casing driver that has been generally used in the past is shown in FIGS. 8 to 10, and the technical contents thereof will be outlined based on these drawings. 8 is a plan view showing an example of a casing driver that has been generally used in the past, FIG. 9 is a right side view of FIG. 8, and FIG. 10 is a front view of FIG.

In FIGS. 8 to 10, reference numeral 1 denotes a female joint 2.
0 and a male joint 24 that is fitted to and detachably attached to the joint fitting attaching / detaching device 2, the casing driver described above, and 3 supporting the casing driver 2 when the casing driver 2 is installed on the ground. A horizontal adjustment jack for adjusting the posture horizontally, 4 is a casing pipe 1 in the center
A substantially square frame-shaped base frame 4a, 4b, 4c having a zero insertion space and forming the base of the casing driver 2,
Reference numeral 4d designates vertical guide frames which are erected at the four corners of the base frame 4, and reference numeral 5 designates a frame shape having a space for inserting the casing pipe 10 in the center thereof to form respective vertical guide frames 4a, 4b,
An elevating frame which is guided up and down by 4c and 4d, 6
Is a thrust cylinder that drives the lifting frame 5 to move up and down. 8 is a ring-shaped lifting frame 6 having an insertion space for the casing pipe 10.
A rotary body rotatably mounted via a bearing (not shown), 9 is a casing gripping band as a gripping means for gripping the casing pipe 10, 10 is the aforementioned casing pipe, and 11 is a casing gripping band 9. A hydraulic band cylinder, which is a component of the casing gripping band 9 for gripping the casing pipe 10 and releasing the grip, 12 is installed at the lower part of the elevating frame 5 and the casing is provided via the rotating body 8 This is a hydraulic motor that rotationally drives the gripping band 9.

Vertical guide frames 4a, 4b, 4c, 4d
Respectively have two guide surfaces a and b, and guide the elevating frame 5 with these two guide surfaces a and b. Of these guide surfaces a and b, the guide surface a is a surface that receives a rotational reaction force generated when the casing gripping band 9 is rotationally driven and the casing pipe 10 is rotated. It is arranged substantially at right angles to the tangential direction. The guide surface b is a surface that functions to suppress horizontal fluctuations of the elevating frame 5 and support it stably, and is arranged parallel to the tangential direction of the rotation circle of the rotating body 8. The lifting frame 5 is formed with two sliding surfaces so as to face the guide surfaces a and b, respectively.
The thrust cylinder 6 includes vertical guide frames 4a, 4b,
Similar to 4c and 4d, the cylinder is attached to the four corners of the base frame 4 and the cylinder is attached to the base frame 4 and the rod is attached to the elevating frame 5, but they may be attached in reverse. Vertical guide frames 4a, 4b,
4c, 4d and the four thrust cylinders 6 are all
In FIG. 8, the vertically adjacent components and the horizontally adjacent components are arranged so as to be line-symmetric with respect to the left and right radial lines and the upper and lower radial lines of the rotating body 8, respectively.

An external gear is formed on the outer periphery of the rotating body 8, and a pinion (not shown) (see reference numeral 13 in FIG. 1 for reference) which is rotationally driven by a hydraulic motor 12 is meshed with the rotating body 8. As a result, the rotation of the hydraulic motor 12 is decelerated and transmitted. The hydraulic motors 12 are arranged on the left and right of the elevating frame 5 in this example. The casing gripping band 9 is attached to the upper part of the rotating body 8 and is rotationally driven by the hydraulic motor 12 via the rotating body 8. Since the casing driver 2 has the above-described structure, when the thrust cylinder 6 is expanded or contracted, the elevating frame 5 will move the vertical guide frames 4a, 4a.
Ascending and descending while being guided by the guide surfaces a and b of b, 4c and 4d, as a result, the casing gripping band 9 can be ascended and descended together with the hydraulic motor 12 and the rotating body 8. Also, by driving the hydraulic motor 12,
The casing gripping band 9 can be decelerated and rotationally driven via the gear transmission mechanism including the pinion and the rotating body 8.

Next, the structure of the casing gripping band 9 will be described. The casing gripping band 9 includes a fixed band 9a having a substantially semicircular arc shape, and one end of each fixed band 9a at both ends thereof.
A pair of substantially arcuate movable bands that are pivotally attached by
b and 9c and a band cylinder 11 connected to the other ends of the pair of movable bands 9b and 9c with pins 16 and 17, respectively, and formed into a substantially ring shape so that a casing pipe insertion space can be formed in the center. Has been formed. Fixed band 9a
Has an inner surface formed in the same arc shape as the outer surface of the casing pipe 10, and is attached to the rotating body 8. The movable bands 9b and 9c can be rotated around the pivot shafts 14 and 15 by operating the band cylinder 11. When the casing pipe 10 is to be gripped with the casing gripping band 9, the movable band 9
b, 9c by band cylinder 11 casing pipe 10
When the casing pipe 10 is turned to the side, the casing pipe 10 is pressed by the movable bands 9b and 9c against the arc-shaped inner surface of the fixed band 9a to be positioned and gripped.

Reference numerals 18 and 19 denote band cylinders 1, respectively.
1 is a hydraulic pipe communicating with the cylinder side (bottom side) and the rod side, and is fixed to the outer periphery of the rotating body 8 with an appropriate fixing tool and is attached near the entire periphery thereof. Each of these hydraulic pipes 18 and 19 is provided with three female joints 20 at intervals of approximately 120 degrees. The male joints 24 are respectively provided in the two conduits that can be selectively connected to the oil supply pipe and the oil drain pipe by switching the switching valve. By connecting them, pressure oil can be supplied to the cylinder side or rod side of the band cylinder 11, and the supplied pressure oil can be discharged. Since the joint attaching / detaching device 1 including the female joint 20 and the male joint 24 is not directly related to the present invention, detailed description thereof will be omitted.

When the casing pipe 10 is to be press-fitted with the casing driver 2 having the above structure, the following steps are performed.

1. The thrust cylinder 6 is extended to the limit to raise the lifting frame 5, and the band cylinder 1
After extending 1 to make the casing pipe insertion space wide, the casing pipe 10 having a cutter bit is inserted into the insertion space at the beginning of press fitting. 2. The band cylinder 11 is contracted, and the casing pipe 10 is grasped by the casing grasping band 9. 3. By the hydraulic motor 12, the casing gripping band 9
The casing pipe 10 by rotatably driving the
To rotate. 4. In this way, in a state where the casing pipe 10 is gripped by the casing gripping band 9 and rotated, the thrust cylinder 6 is contracted and the elevating frame 5 is lowered to push the casing pipe 10 to excavate the ground,
The casing pipe 10 is press-fitted. 5. When the thrust cylinder 6 contracts to the limit, the rotational drive of the casing gripping band 9 and the drive of the thrust cylinder 6 by the hydraulic motor 12 are stopped. 6. The band cylinder 11 is extended to release the casing pipe 10 from the casing gripping band 9. 7. With the casing pipe 10 released, the thrust cylinder 6 is extended to the limit again and the elevating frame 5 is raised. 8. A new casing pipe 10 that does not have a cutter bit as necessary in the casing pipe 10 that is press-fitted.
Add more. 9. By repeating the above steps 2 to 8, the casing pipe 10 having a predetermined length is press-fitted. The casing driver 10 can also pull out the casing pipe 10, but the description thereof will be omitted. By the way, in the thrust cylinder 6, starting the lifting frame 5,
Various weights of the devices such as the rotating body 8, the casing gripping band 9, the hydraulic motor 12 and the casing driver 2 installed therein act. Further, when the casing pipe 10 is being held by the casing holding band 9,
The weight of the casing pipe 10 also acts. Therefore, the thrust cylinder 6 is inevitably subjected to a force for compressing the thrust cylinder 6 even when the casing pipe 10 is not applied with a pushing force during the operation of the casing driver 2. Such a force acting on the thrust cylinder 6 is referred to as a self-sinking load in this specification. Casing pipe 10
When excavating the ground by pushing while rotating the casing pipe with a casing driver, the casing pipe 10 must be supported unless a supporting force for supporting the self-sinking load is applied by the thrust cylinder 6.
Has run away and this self-sinking load causes casing pipe 1
As a pushing force against 0, the excavation control when excavating the ground by the casing driver cannot be performed in a stable state. As a result, the casing driver may not be able to efficiently excavate the ground, or the cutter bit of the casing pipe 10 may be damaged.

As a technique for solving the problem caused by the self-sinking load during the excavation control of the casing driver 2, a technique called a pushing force control method for a rotary tubing device has been proposed in Japanese Patent Publication No. 7-15233. Has been done. Therefore, the technique proposed in this publication will be described as a conventional technique. In that case, the terms used in this specification are used as much as possible so that the correspondence with the present invention becomes clear. The terms used in this publication will be added in parentheses after the terms used first. The technique proposed in this publication makes it impossible to perform efficient excavation depending on the soil quality when a self-sinking load acts during excavation with a casing driver (rotary tubing device), and a cutter bit (excavation) for a casing pipe (casing tube). It is intended to improve the excavation control method of the casing driver, recognizing that it may damage the work bit).

This casing driver excavation control method includes a rotating device as a holding means for holding a casing pipe, and a thrust cylinder (cylinder) capable of supporting the rotating device via an elevating frame (elevating device) and ascending and descending. ) And a hydraulic motor that rotationally drives a rotating device and an electromagnetic proportional relief valve that can adjust the pressure on the cylinder side (cap side cylinder chamber) of the thrust cylinder, and a casing pipe having a cutter bit at the tip. When excavating the ground, the control is performed so as to prevent the casing pipe from running away. A relief valve for fixedly setting the pressure on the rod side (head side cylinder chamber) of the thrust cylinder to generate the maximum pushing force Fmax is provided.
The set pressure R1 of the electromagnetic proportional relief valve includes the pressure f1 on the rod side of the thrust cylinder that generates the maximum pushing force Fmax, the weight Wc of the casing pipe, the weight Wd of the rotating device and the lifting frame when adjusted to the maximum set pressure. By adjusting the set pressure R1 of the electromagnetic proportional relief valve,
The thrust cylinder can be expanded and contracted.

In the conventional casing driver excavation control method thus configured, when the set pressure R1 of the electromagnetic proportional relief valve is set to 0, the pushing force acting on the cutter bit of the casing pipe becomes f1 + Wc + Wd. It is said that when the maximum pushing force acts on the cutter bit and the set pressure R1 of the electromagnetic proportional relief valve is f1 + Wc + Wd, the pushing force acting on the cutter bit becomes zero. In the state where the pushing force acting on the cutter bit is zero, only the supporting force for supporting the self-sinking load is applied on the cylinder side of the thrust cylinder 6 together with the pressure against the pressure on the rod side of the thrust cylinder. In this conventional technique, f1
+ Wc + Wd (pressure on the cylinder side of the thrust cylinder)
It can be said that −f1 (pressure on the rod side of the thrust cylinder), that is, Wc + Wd, is regarded as a load corresponding to the self-sinking load.

[0013]

As described above, according to the conventional technique, Wc + Wd is considered to be a load corresponding to the self-sinking load, but this load Wc + Wd is actually excavated in the ground by the casing pipe 10 and press-fitted. At this time, the self-sinking load acting on the thrust cylinder 6 is not accurately reflected.
Therefore, this will be described with reference to FIG. Figure 11
FIG. 4 is an explanatory diagram of a self-sinking load that acts on a thrust cylinder when excavating with a casing driver. In FIG. 11, the parts denoted by the same reference numerals as those in FIGS.
Represents the part equivalent to. FIG. 11 schematically shows the casing driver already described in FIGS. 8 to 10, and the pinion 1 not shown in these figures is shown.
It is also schematically shown that the rotor 3 is decelerated and rotated by meshing 3 with the external gear of the rotor 8.

In FIG. 11, Wc is the weight of the casing pipe 10, Wr is the weight of the lifting frame 5, and Wm.
Is the weight of the rotating body 8 and the casing gripping band 9, and Wp is the self-sinking load acting on the thrust cylinder 6 when the ground is excavated by the casing pipe 10. Self- sinking load Wp
Other weights such as a stage installed on the elevating frame 5 also act on the weight acting as the above. However, for convenience of description, here, the weight acting as the self-sinking load Wp is only the weight shown in FIG. Suppose that While excavating the ground by the cutter bit 26 of the casing pipe 10, a dynamic frictional force acts between the peripheral surface of the casing pipe 10 and the ground, and the dynamic frictional force of the peripheral surface of the casing pipe 10 is Fm. The dynamic frictional force Fm on the peripheral surface of the casing pipe 10 acts to reduce the weight acting as the self-sinking load Wp. Then, the self-sinking load Wp
Can be expressed by the following formula 1. Formula 1 Wp = (Wc + Wr + Wm) -Fm It is considered that the weight Wd of the rotating device and the elevating frame referred to in the prior art corresponds to Wr + Wm in Formula 1.

As will be apparent from an analysis of the setting method of the set pressure R1 of the electromagnetic proportional relief valve in the prior art with reference to this equation 1, in the prior art, the ground is excavated by the casing pipe. The dynamic frictional force Fm of the casing pipe peripheral surface, which sometimes acts, is not taken into consideration at all, and the load Wc + Wd which is considered to correspond to the self-sinking load in the conventional technique.
Does not accurately reflect the self-sinking load that acts on the thrust cylinder when the ground is actually excavated and press-fitted with the casing pipe. That is, when excavating the ground with the casing pipe, the dynamic frictional force should act between the peripheral surface of the casing pipe and the ground to reduce the load Wc + Wd, but in the conventional technique, it corresponds to a self-sinking load. When measuring the load, such dynamic friction force is not incorporated, and as a result, the self-sinking load is largely measured.
As a result, the set pressure of the electromagnetic proportional relief valve for adjusting the pressure on the cylinder side of the thrust cylinder when excavating the ground while controlling the electromagnetic proportional relief valve to prevent the escape of the casing pipe is: Therefore, the energy loss in the electromagnetic proportional relief valve will increase.

Since the dynamic frictional force on the peripheral surface of the casing pipe gradually increases as a new casing pipe is added as the press-fitting of the casing pipe progresses, the electromagnetic frictional force increases due to the fact that the dynamic frictional force is not incorporated in the measurement of the self-sinking load. The energy loss in a relief valve is not negligible. Therefore, it is necessary to accurately measure the self-sinking load acting on the thrust cylinder when excavating the ground with the casing pipe, according to the mathematical formula 1.
However, since the method of measuring the dynamic friction force generated between the peripheral surface of the casing pipe and the ground at the time of excavation with the casing pipe has not been established, the conventional technology incorporates the dynamic friction force to accurately measure the self-sinking load. It was technically difficult to measure.

The respective inventions of this application were created in view of such conventional technical situations, and the first technical problem of the invention of this application is to provide a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. Another object of the present invention is to provide a casing driver excavation control technique that is used in a casing driver and can reduce the energy loss in the relief valve to prevent the casing pipe from running away. A second technical object of the invention of this application is to provide a method for measuring a self-sinking load of a casing driver, which can accurately measure a self-sinking load acting on a thrust cylinder during excavation with a casing pipe.

[0018]

(A) Means for Solving the First Technical Problem The first technical problem is the first invention of this application according to claim 1 of the claims. , A second invention of this application according to claim 2, a third invention of this application according to claim 3, a fourth invention of this application according to claim 4,
A fifth invention of this application according to claim 5 and claim 8
According to the sixth invention of this application, the problems are solved. As means for solving the technical problems, in the first invention of this application, the following 1) means, in the second invention of this application, the following 2) means, and the 3rd of this application In the second invention, the means of the following 3), the fourth of this application
The fourth invention adopts the following means 4), the fifth invention of this application adopts the means 5), and the sixth invention of this application adopts the means 6).

1) A gripping means for gripping the casing pipe, a thrust cylinder capable of supporting and lifting the gripping means, a motor for rotationally driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. When excavating the ground with a casing pipe having a cutter bit at the tip using a provided casing driver, in a casing driver excavation control method for controlling so as to prevent the casing pipe from running away, the cutter bit can be separated from the ground The first step of extending the thrust cylinder so as to leave a stroke and holding the casing pipe by the holding means, and raising the casing pipe held by the holding means by extending the thrust cylinder so as to separate the cutter bit from the ground. Drive the motor with The second step of further rotating, and at least the cylinder side pressure of the cylinder side pressure and the rod side pressure of the thrust cylinder is measured with the casing pipe being raised and rotated in this way, and based on the measurement result After passing through the third step of setting the set pressure of the relief valve so that the supporting force for supporting the gripping means does not fall below the self-settling load obtained by the pressure on the cylinder side of the thrust cylinder, the casing pipe is driven by the motor. The ground was excavated by pushing in with a thrust cylinder while rotating.

2) In the casing driver excavation control method for controlling the casing pipe so as to prevent the casing pipe from escaping, the thrust cylinder is extended so that the casing pipe gripped by the gripping means separates the cutter bit from the ground. In the first step of raising and rotating the motor by driving the motor, and in the state of raising and rotating the casing pipe in this way, at least the cylinder side pressure of the cylinder side pressure and rod side pressure of the thrust cylinder is set. A second step of measuring and setting the set pressure of the relief valve so that the self-sinking load obtained based on the measurement result does not fall below the supporting force for supporting the gripping means by the pressure on the cylinder side of the thrust cylinder; After releasing the grip of the casing pipe with the gripping means, After a third step of gripping the casing pipe by the gripping means extending the thrust cylinder to allow the pushing and adapted to excavate the ground by pushing thrust cylinder while rotating the casing pipe at the motor.

3) A gripping means for gripping the casing pipe, a thrust cylinder capable of supporting and lifting the gripping means, a motor for rotationally driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. When excavating the ground with a casing pipe having a cutter bit at the tip using the provided casing driver, the casing driver's excavation control device controls to prevent the casing pipe from running away. And a pressure measuring means of the thrust cylinder for measuring at least the cylinder side pressure of the rod side pressure, and a casing driver control mechanism for inputting the measurement result relating to the thrust cylinder pressure by the pressure measuring means. Of this casing driver The control mechanism extends the thrust cylinder so as to separate the cutter bit from the ground and rotates the motor while measuring the pressure measured by the pressure measuring means of the thrust cylinder. It is configured to have a control function of controlling so as to set the set pressure of the relief valve so that the supporting force for supporting the gripping means does not fall below the side pressure.

4) In the excavation control method of the casing driver for controlling the casing pipe to prevent the casing pipe from escaping, the cutter bit can be separated from the ground in the same manner as in 1) using the hydraulic motor as the motor for rotating the gripping means. A first step of extending the thrust cylinder so as to leave a stroke and holding the casing pipe with the holding means;
The casing pipe grasped by the grasping means is raised by extending the thrust cylinder so as to pull the cutter bit away from the ground and is rotated by driving the hydraulic motor, and thus the casing pipe is raised and rotated. In this state, at least the cylinder side pressure of the thrust cylinder cylinder side and rod side pressure is measured, and the self-sinking load obtained based on the measurement result is supported by the thrust cylinder cylinder side pressure. The relief valve set pressure is set so that the supporting force for
A third step of measuring the driving pressure of the hydraulic motor in a state where the casing pipe is raised and rotated, and determining the value related to the rotational torque of the hydraulic motor based on the measurement result to measure the value related to the circumferential surface friction torque; , The casing pipe is pushed by the thrust cylinder while being rotated by the hydraulic motor to excavate the ground, and at that time, the driving pressure of the hydraulic motor is set to the sum of the preset value related to the excavation torque and the value related to the circumferential friction torque. Based on the fourth step of pushing the casing pipe with the thrust cylinder so as to bring the actual value relating to the rotational torque of the hydraulic motor closer to each other, the excavation of the ground performed by the casing pipe is controlled using the casing driver. I did it.

5) In the same excavation control method for a casing driver as in 4) for controlling the escape of the casing pipe, the casing cylinder grasped by the grasping means extends the thrust cylinder so as to separate the cutter bit from the ground. In the first step of raising and rotating the motor by driving the motor, and in the state of raising and rotating the casing pipe in this way, at least the cylinder side pressure of the cylinder side pressure and rod side pressure of the thrust cylinder is set. The set pressure of the relief valve is set so that the self-sinking load obtained based on the measurement result does not fall below the supporting force for supporting the gripping means by the pressure on the cylinder side of the thrust cylinder.
Similarly, the driving pressure of the hydraulic motor is measured while the casing pipe is being raised and rotated, and the value related to the rotational torque of the hydraulic motor is obtained based on the measurement result to measure the value related to the circumferential surface friction torque. After releasing the grip of the casing pipe by the gripping means, a third step of extending the thrust cylinder to grip the casing pipe by the gripping means so that the casing pipe can be pushed, and rotating the casing pipe with a hydraulic motor. While excavating the ground by pushing it with the thrust cylinder while rotating, the rotation of the hydraulic motor obtained based on the driving pressure of the hydraulic motor with respect to the sum of the preset value related to the excavation torque and the value related to the peripheral friction torque. Insert the casing pipe into thrust thrust so that the actual torque values are close to each other. By a fourth step of pushing in Da,
The casing driver was used to control the excavation of the ground performed by the casing pipe.

6) In a casing driver excavation control device for controlling so as to prevent the casing pipe from running away as in the case of 3), in which a hydraulic motor is used as a motor for rotating the gripping means, the cutter bit is separated from the ground. Detecting means, a thrust cylinder pressure measuring means for measuring at least the cylinder side pressure of the cylinder side pressure and the rod side pressure of the thrust cylinder, and a drive for measuring the driving pressure of the hydraulic motor. Make sure that the pressure on the cylinder side of the thrust cylinder does not lower the supporting force for supporting the gripping means against the self-sinking load obtained by inputting the measurement results of the pressure measuring means and the pressure measuring means of the thrust cylinder. The relief valve setting means for setting the set pressure of the relief valve and the measurement result of the drive pressure measuring means are input. Rotation torque calculation means for calculating a value relating to rotation torque of the hydraulic motor during rotation of the hydraulic motor based on the measurement result, and rotation torque calculation means when the detection means detects that the cutter bit is separated from the ground. The actual value related to the rotational torque of the hydraulic motor calculated by the rotational torque calculation means when excavating the ground with the casing pipe, with respect to the sum of the value related to the rotational torque of the hydraulic motor calculated in A thrust cylinder control means for controlling the drive of the thrust cylinder is provided so as to bring the values closer to each other.

All of the first, second, fourth and fifth inventions of this application relating to the casing driver excavation control method are for setting the set pressure of the relief valve. Since the underlying self-sinking load is determined under the condition that the casing pipe is raised so that the cutter bit is separated from the ground and is rotated, the resulting self-sinking load is the resulting self-sinking load of the casing pipe by the ground. The friction between the peripheral surface of the casing pipe and the ground is woven under the condition that the supporting force is not applied. Therefore, the self-sinking load acting on the thrust cylinder when the ground is actually excavated and press-fitted by the casing pipe is accurately reflected. Therefore, when the set pressure of the relief valve is set so as to prevent the escape of the casing pipe, the set pressure is not set too large, and the energy loss in the relief valve is reduced. You can Particularly, in the first invention and the fourth invention of this application, for setting the relief valve and the like at the start stage of the pushing process of the casing pipe started by the extension of the thrust cylinder and the gripping of the casing pipe. Since the series of steps from the first step to the third step are combined so as to be integrated, and these steps can be carried out along the path of carrying out the pushing step, the pushing operation of the casing pipe can be carried out efficiently. It can be carried out.

A third invention of this application relating to a casing driver excavation control apparatus is provided with means for carrying out the first invention and the second invention of this application relating to the casing driver excavation control method. A sixth invention of this application relating to a driver excavation control device includes means for carrying out the fourth invention and the fifth invention of this application relating to a casing driver excavation control method. Similar to each of these inventions relating to the driver excavation control method, when the set pressure of the relief valve is set so as to prevent the escape of the casing pipe, the energy loss in the relief valve can be reduced. Also, the fourth invention of this application,
In the fifth invention and the sixth invention, the set value relating to the rotation torque of the hydraulic motor is set based on the excavation torque which is the most important factor in preventing damage to the cutter bit of the casing pipe and efficient excavation. Then, it can be set to an appropriate value according to the actual excavation work.

(B) Means for Solving the Second Technical Problem The second technical problem is set forth in claim 11 of the claims.
According to the seventh invention of this application, the following means 7) are adopted as means for solving the problems.

7) The casing pipe is grasped by using a casing driver having a grasping means for grasping the casing pipe, a thrust cylinder capable of supporting the grasping means and raising and lowering it, and a motor for rotationally driving the grasping means. A first step of raising the casing pipe by extending the thrust cylinder so as to separate the cutter bit from the ground and rotating the casing pipe by driving a motor;
In this way, at least the cylinder side pressure of the thrust cylinder cylinder side pressure and the rod side pressure is measured with the casing pipe rotated and raised, and the value relating to the self-sinking load is calculated based on these measurement results. The self-sinking load acting on the thrust cylinder was measured by the second step.

A seventh invention of this application relating to a method for measuring a self-sinking load of a casing driver is to measure a self-sinking load under a condition in which a casing pipe is raised so as to separate a cutter bit from the ground and is rotated. Therefore, as described above, the self-sinking load measured in this way is the one in which the friction between the peripheral surface of the casing pipe and the ground is woven under the condition that the supporting force of the casing pipe by the ground does not act. Therefore, according to the present invention, it is possible to accurately measure the self- sinking load acting on the thrust cylinder during excavation with the casing pipe.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, how each invention of this application relating to a method for controlling excavation of a casing driver, an excavation control device, a method for measuring a self-sinking load, and a method for measuring a frictional torque on a peripheral surface is practically embodied. BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the respective inventions will be clarified by referring to FIGS. FIG. 1 is a hydraulic circuit diagram showing an example of a hydraulic circuit of a casing driver for explaining each invention of this application.
FIG. 2 is a flow chart showing an example of a casing driver excavation control method for explaining each invention of this application, and FIG.
FIG. 4 is a diagram showing a control function useful for the control in the hydraulic circuit diagram of FIG. 1 by the casing driver excavation control method and the excavation control device of the invention of the present application, and FIG. 4 explains the significance of the control function of FIG. FIG. 5 is a conceptual diagram showing the relationship between the clearance angle of the cutter bit and the cutting trajectory for the purpose, FIG. 5 is a block diagram showing an example of a casing driver excavation control device for explaining each invention of this application, and FIG. 6 is this application. FIG. 7 is a hydraulic circuit diagram showing another example of a hydraulic circuit of a casing driver for explaining each invention of FIG. 6, and FIG. 7 is a hydraulic circuit diagram of FIG. 6 by a casing driver excavation control method and an excavation control device of the invention of this application. It is a figure which shows the control function useful for control of. In these figures, the parts denoted by the same reference numerals as those in FIGS. 8 to 10 represent the same parts as those in FIGS. 8 to 10.

The casing driver used when the inventions of this application are embodied can support the casing gripping band 9 as a gripping means for gripping the casing pipe 10 and the casing gripping band 9 to raise and lower it. It has a thrust cylinder 6 and a hydraulic motor 12 that drives the casing gripping band 9 to rotate, and its basic structure is the same as that of a conventional casing driver shown in FIGS. 8 to 10. Absent. Further, as with the casing driver used in the method described in Japanese Patent Publication No. 7-15233, which is shown as a conventional technique, a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder is provided. Note that, similarly to FIG. 11, FIGS. 1 and 6 schematically show that the pinion 13 is meshed with the external gear of the rotating body 8 to rotate the rotating body 8 at a reduced speed.

First, the hydraulic circuit of FIG. 1 will be described. Reference numeral 30a is a forward rotation pressure of the hydraulic motor 12 (hydraulic motor 12).
Pressure sensor for measuring the pressure on the inlet side of), 30b
Is a pressure sensor for measuring the reverse pressure of the hydraulic motor 12 (pressure on the outlet side of the hydraulic motor 12), 31a is a pressure sensor for measuring the cylinder side (bottom side) pressure of the thrust cylinder 6, and 31b is a thrust. It is a pressure sensor for measuring the pressure on the rod side of the cylinder 6. The pressure sensor 30a and the pressure sensor 30b are provided to measure the driving pressure of the hydraulic motor 12 by measuring the differential pressure between the forward rotation pressure and the reverse rotation pressure of the hydraulic motor 12, and form the driving pressure measurement means of the hydraulic motor 12. . The reverse rotation pressure of the hydraulic motor 12 is mainly generated by the resistance of the conduit on the outlet side, and becomes a negligible value close to 0 unless the conduit on the outlet side is extremely long. Pressure sensor 30 for measuring force
Although the measurement result may be regarded as the driving pressure of the hydraulic motor by using only a, the pressure sensor 30b for measuring the pressure on the reverse rotation side is also provided in this example for the sake of accuracy. The pressure sensor 31a and the pressure sensor 31b are the thrust cylinder 6
It is provided in order to measure the external force for shrinking the thrust cylinder 6 that works when the vehicle is not driven, that is, the self-sinking load. When the rod side of the thrust cylinder 6 is not driven, like the reverse pressure of the hydraulic motor 12, the pressure is close to 0. Therefore, the pressure sensor 31b may be omitted and only the pressure sensor 31a may be provided.

Reference numeral 32 is a pilot operated relief valve capable of adjusting the set pressure according to the magnitude of pilot pressure, and 32a is provided in an oil passage leading from the secondary side of the pilot operated relief valve 32 to the tank 44. An electromagnetic switching valve for hydraulic oil for opening and closing the passage, 32b is provided in a bypass pipe line of the electromagnetic proportional relief valve 34, allows the pressure oil to be supplied to the cylinder side of the thrust cylinder 6, and allows the cylinder side of the thrust cylinder 6 to be supplied. A check valve for preventing the discharge of pressure oil from the valve 33 is a pilot operated relief valve 3
2 is a solenoid-operated switching valve for pilots that switches pilot lines for guiding pilot pressure to the signal receiving portion, and 34 is for adjusting the magnitude of pilot pressure output to the signal receiving portion of the pilot operated relief valve 32. An electromagnetic proportional relief valve, 35 is a hydraulic pump for a thrust cylinder that generates hydraulic pressure for driving the thrust cylinder 6, 36 is a power source for driving the hydraulic pump 35, and 37 is a position A and a position B from the neutral position. 4 port 3 position electromagnetic directional control valve for controlling the direction of the flow of pressure oil so as to reduce and expand the thrust cylinder 6 respectively, and 38 is a direction to the oil passage on the rod side of the thrust cylinder 6. It is connected in parallel with the switching valve 37, and the flow rate of pressure oil supplied to the rod side of the thrust cylinder 6 can be adjusted by an electric signal. Electromagnetic proportional Flocon, 39 is a relief valve for the hydraulic circuit protection.

The electromagnetic switching valve 32a for hydraulic oil is normally switched to the B position and closed as shown in FIG.
A only when an electric signal is output from the judgment processing unit 51
The pressure oil on the secondary side of the pilot operated relief valve 32 is released to the tank 44 by switching to the position and opening.
The electromagnetic switching valve 33 for pilot is normally switched to the B position as shown in FIG. 1, and an electric signal is output from the determination processing unit 51 described in detail later to the signal receiving unit of the electromagnetic switching valve 33. Only sometimes can it be switched to the A position. The electromagnetic proportional relief valve 34 can adjust the magnitude of the set pressure in proportion to the output value of the electric signal output from the determination processing unit 51 to increase or decrease the hydraulic pressure on the primary side. The pilot operated relief valve 32 has its pilot pressure introduced from an oil passage on the cylinder side of the thrust cylinder 6 and adjusted by an electromagnetic proportional relief valve 34. As a result, the set pressure of the pilot operated relief valve 32 is set to the same value as the set pressure of the pilot operated relief valve 32.

The direction switching valve 37 stops the supply and discharge of the pressure oil of the thrust cylinder 6 at the neutral position, and when it is switched to the A position, it switches the pressure oil of the hydraulic pump 35 to the thrust cylinder 6.
The flow of the pressure oil is controlled so that the pressure oil on the cylinder side of the thrust cylinder 6 can be discharged to the oil tank 44 through the pilot-operated relief valve 32 while being supplied to the rod side. Also, when switching to the B position, the hydraulic pump 35
The pressure oil of the thrust cylinder 6 through the check valve 32b.
The pressure oil on the rod side is controlled so that the pressure oil on the rod side can be discharged to the oil tank 44. Therefore, when switching to the A position, the thrust cylinder 6
Is reduced to lower the elevating frame 5 and switched to the B position, the thrust cylinder 6 is extended to elevate the elevating frame 5. The electromagnetic proportional flow controller 38 is an electromagnetic variable throttle valve 38a capable of adjusting the opening amount in proportion to the output value of the electric signal from the determination processing unit 51, and a check provided in a bypass pipe line of the throttle valve 38a. Valve 38b
Composed of and. Then, only when the direction switching valve 37 is switched to the neutral position, the electromagnetic variable throttle valve 38a is opened by a command from the determination processing unit 51 to adjust the opening amount, and the pressure oil supplied to the rod side of the thrust cylinder 6 is supplied. Adjust the flow rate of. In FIG. 1, for convenience of description, only an example in which only one of the plurality of thrust cylinders 6 is controlled by such a hydraulic circuit is shown, but actually, the other thrust cylinders 6 are also respectively provided with hydraulic lines. And a plurality of thrust cylinders 6 are connected in parallel so that the pressure oil of the hydraulic pump 35 for thrust cylinders is distributed.

Reference numeral 40 is a hydraulic pump for a hydraulic motor which generates hydraulic pressure for driving the hydraulic motor 12, 41 is a power source for driving the hydraulic pump 40, 42 is a relief valve for protecting the hydraulic circuit, and 43 is a relief valve. From neutral position to A position and B
By switching to the position, the direction of the flow of the pressure oil is controlled so that the hydraulic pump 40 is rotated in the forward and reverse directions, respectively.
An electromagnetic directional control valve at the port 3 position, 44 is an oil tank for storing hydraulic oil, and 45 is a stroke sensor for detecting the stroke of the thrust cylinder 6. The directional control valve 43 is
When the supply and discharge of the pressure oil of the hydraulic motor 12 is stopped at the neutral position and the pressure oil is switched to the A position, the pressure oil of the hydraulic pump 40 is supplied to the forward rotation side of the hydraulic motor 12 and the pressure oil on the reverse rotation side is supplied to the oil tank. The flow of the pressure oil is controlled so that it is discharged to 44. Also, when switching to the B position, the hydraulic pump 4
The pressure oil of 0 is supplied to the reverse rotation side of the hydraulic motor 12, and the flow of the pressure oil is controlled so that the pressure oil on the forward rotation side is discharged to the oil tank 44. Therefore, when the neutral position is switched to the A position and the B position, respectively, the hydraulic motor 12 is driven in the forward direction and the reverse direction, respectively, and stopped at the neutral position. Instead of providing the stroke sensor 45 independently, a thrust cylinder with a built-in stroke sensor may be used.

Reference numeral 51 denotes a judgment processing section which constitutes a control mechanism of the casing driver, and as shown in FIG. 5, the pressure on the forward rotation side and the pressure on the reverse rotation side of the hydraulic motor 12 in the pressure sensor 30a and the pressure sensor 30b. The measurement result regarding the pressure on the cylinder side of the thrust cylinder 6 and the pressure on the rod side by the pressure sensor 31a and the pressure sensor 31b, and the measurement result regarding the stroke of the thrust cylinder 6 by the stroke sensor 45 are input. Various calculations are performed on the basis of the measurement results and control is performed based on the calculation results. The determination processing unit 51 constitutes a control mechanism for the casing driver together with the setting unit 50 shown in FIG. 5 and the hydraulic circuit shown in FIG. In the setting unit 50, an automatic / manual changeover switch for setting whether to perform the press-fitting process of the casing pipe 10 by the casing driver in the automatic operation or the manual operation, and a preset excavation torque setting. An operation unit or the like for setting the excavation torque and the control function value is provided, and the setting results of these operation units are input as shown in FIG. The judgment processing unit 51 operates based on such a setting result.

As the technical means related to the inventions of this application, the judgment processing section 51 controls the thrust cylinder 6 so as to extend it by the height of the cutter bit 26 of the casing pipe 10, and the cutter bit 26. When the stroke sensor 45 detects that the vehicle is separated from the ground, the measurement results regarding the pressure on the cylinder side and the pressure on the rod side of the thrust cylinder 6 measured by the pressure sensor 31a and the pressure sensor 31b are input, respectively. Self-sinking load calculation means for calculating a value relating to the self-sinking load based on the measurement result, and based on the calculation result, the supporting force for supporting the casing gripping band 9 by the pressure on the cylinder side of the thrust cylinder 6 does not fall below the self-sinking load. The relief valve setting to set the set pressure of the pilot operated relief valve 32 Step, and the measurement results regarding the pressure on the forward rotation side and the pressure on the reverse rotation side of the hydraulic motor 12 measured by the pressure sensor 30a and the pressure sensor 30b are input, and the hydraulic pressure during rotation of the hydraulic motor 12 is input based on these measurement results. The rotation torque calculation means for calculating a value relating to the rotation torque of the motor 12, and the hydraulic motor 1 calculated by the rotation torque calculation means when the stroke sensor 45 detects that the cutter bit 26 is separated from the ground.
The hydraulic motor 12 calculated by the rotation torque calculation means when excavating the ground with the casing pipe 10 with respect to the sum of the value related to the rotational torque of 2 (circumferential friction torque described later) and the preset value related to the excavation torque. There is provided thrust cylinder control means for controlling the drive of the thrust cylinder 6 so as to bring the actual values regarding the rotational torque of the above into close relation.

Therefore, the casing driver excavation control method executed by the determination processing section 51 will be described with reference to the flow chart of FIG. When the ground is excavated by the casing pipe 10 by using the casing driver while press-fitting the ground, normally, the pushing speed of the casing pipe 10, that is, the thrust without changing the rotating speed of the casing pipe 10, that is, the rotating speed of the hydraulic motor 12. Since only the pushing speed of the cylinder 6 is changed so that the excavation torque has an appropriate value, in the excavation control method for the casing driver described below, the hydraulic pressure is increased until at least one press-fitting process is completed. The rotation speed of the motor 12 is not changed. When the step of press-fitting the casing pipe 10 with the casing driver is performed manually, the automatic setting in the setting unit 50 of the control mechanism of the casing driver is performed.
Switch the manual selector switch to manual. Then,
The determination processing unit 51 issues a command by an electric signal to the switching valve 33 and the electromagnetic proportional flow controller 38 in the hydraulic circuit of FIG. 1 to operate them as follows. a) The switching valve 33 is switched to the B position. b) Electromagnetic variable throttle valve 38 in the electromagnetic proportional flow controller 38
Fully close a.

When the switching valve 33 is switched to the B position as shown in a), the pilot port of the pilot operated relief valve 32 communicates with the tank 44, so that the set pressure of the pilot operated relief valve 32 is 0 kg / cm. It becomes ² and there is no passage resistance. In addition, electromagnetic proportional flow control 3
When 8 is closed as in b), this electromagnetic proportional flow controller 38
The pressure oil is prevented from flowing toward the rod side of the thrust cylinder 6 through the oil passage of the hydraulic pump 3, and as a result, the hydraulic pump 3
The pressure oil of No. 5 can be supplied to the rod side of the thrust cylinder 6 only through the direction switching valve 37. In such a state, when the operator manually operates the operation means such as an operation lever (not shown) to switch the direction switching valve 37 to the A position, the thrust cylinder 6 can be contracted, and to the B position, The thrust cylinder 6 can be extended. In this way, the process of press-fitting the casing pipe 10 can be carried out manually by a usual method.

Next, a method of performing the excavation control method of the casing driver of the present invention to perform automatic excavation control will be described. When performing automatic excavation control, the automatic / manual changeover switch is automatically switched, and the operating unit that sets the set excavation torque and control function value is operated to set the set excavation torque and control function value, and the properties of the ground, etc. Set it to a value that is suitable for the excavation conditions, taking into consideration. In this example,
When performing automatic excavation control, manual operation is performed in the first step a).

(A) Extension of thrust cylinder and grasping of casing pipe 10 First, by manually switching the direction switching valve 37 to the B position, the stroke that allows the thrust cylinder 6 to be extended by the height of the cutter bit 16 is left. Extend the thrust cylinder 6. That is, when the maximum stroke of the thrust cylinder 6 is Lo and the height of the cutter bit 26 of the casing pipe 10 is Lst, the thrust cylinder 6 is extended by Lo-Lst and then the directional control valve 37.
Switch to the neutral position by manual operation. In that case, the operator confirms whether or not the thrust cylinder 6 is extended by Lo-Lst by monitoring an instrument that displays the measurement result of the stroke sensor 45. Next, the casing pipe 10 is gripped by the casing gripping band 9, and then the hydraulic motor 12 is driven to rotationally drive the casing gripping band 9 to rotate the casing pipe 10.

(B) Re-extension of the thrust cylinder after gripping the casing pipe (a) After this step, when the automatic / manual changeover switch of the setting section 50 is automatically changed, the direction changeover valve 37 causes the judgment processing section 51 to move. It is automatically switched to the B position by a command from. As a result, the pressure oil of the hydraulic pump 35 is supplied to the cylinder side of the thrust cylinder 6 through the check valve 32b, and the pressure oil on the rod side is discharged to the oil tank 44 through the discharge port of the direction switching valve 37, so that the thrust cylinder 6 is Extend. In this way, when the thrust cylinder 6 extends by the height Lst of the cutter bit 26, the determination processing unit 51 determines this by the stroke value of the thrust cylinder 6 input from the stroke sensor 45,
The direction switching valve 37 is returned to the neutral position. As a result, the casing pipe 10 rises by Lst and the cutter bit 26
Is kept separated from the ground. In that case,
The casing pipe 10 is gripped and rotated by the casing gripping band 9 that is rotationally driven by the hydraulic motor 12. In this example, the casing pipe 10 is preliminarily rotated in this manner.
May be rotated after being raised by Lst.

C) Measurement by calculation of self-sinking load In this state, when the casing pipe 10 is rotated and lifted so as to be separated from the ground, the pressure sensor 31
Since the pressure sensor 31b and the pressure sensor 31b respectively measure the pressure on the cylinder side and the pressure on the rod side of the thrust cylinder 6, these measurement results are sent to the determination processing unit 51. The determination processing unit 51 first calculates the self-sinking load according to the following Equation 2 based on these measurement results. Formula 2 Wp = (Po × So−Pt × St) × N In the above formula, Wp is the self-sinking load Po is the cylinder side pressure of the thrust cylinder 6, So is the cylinder side pressure receiving area Pt of the thrust cylinder 6, and Pt is the thrust cylinder 6 The rod side pressure St is the rod side pressure receiving area N of the thrust cylinder 6, and is the number of thrust cylinders 6 to be driven.

The self-sinking load W thus measured by calculation
p is measured in a state in which the casing pipe 10 is separated from the ground and rotated, and therefore the friction between the peripheral surface of the casing pipe 10 and the ground is measured under the condition that the supporting force of the casing pipe 10 by the ground does not act. It is measured by weaving. Therefore, when actually excavating the ground with the casing pipe 10 and press-fitting the ground, the thrust cylinder 6
It can be said that it accurately reflects the self-sinking load acting on the.
The self-sinking load Wp is stored in a storage device so that the self-sinking load Wp can be displayed by a display means, and can be output as needed, thereby forming a self-sinking load measuring device.

D) Measurement by calculation of circumferential friction torque In the state where the casing pipe 10 is rotated by the step (b) and raised so as to be separated from the ground,
In this example, in addition to the self-sinking load Wp, the circumferential surface friction torque is measured so that the rotational torque of the hydraulic motor 12 can be appropriately controlled as described later. Since the pressure sensor 30a and the pressure sensor 30b measure the forward rotation pressure (pressure on the inlet side of the hydraulic motor 12) and the reverse rotation side (pressure on the outlet side) of the hydraulic motor 12, respectively, the determination processing unit 51 , These measurement results are also sent. The determination processing unit 51 calculates the actual value T ′ of the cutter rotation torque, which is the rotation torque of the hydraulic motor 12, according to the following Equation 3 based on these measurement results. Formula 3 T ′ = β × (Ps−Pg) × (Zg / Zp) × Nm In the above equation, T ′ is the actual value of the rotational torque of the hydraulic motor 12, and the cutter rotational torque β is the hydraulic motor output shaft torque coefficient Ps. Is a forward rotation pressure of the hydraulic motor 12 (pressure on the inlet side of the hydraulic motor 12) Pg is a reverse rotation pressure of the hydraulic motor 12 (pressure on the outlet side of the hydraulic motor 12) Zg is an external tooth provided on the outer peripheral portion of the rotating body 8. The number of teeth Zp of the gear is the number of teeth Nm of the pinion 13 and the number of hydraulic motors 12. The hydraulic motor output shaft torque coefficient β is a coefficient corresponding to the ratio of the effective value of the output shaft torque of the hydraulic motor 12 to the theoretical value.

The cutter rotation torque T'required when press-fitting the casing pipe 10 while excavating the ground with the cutter bit 26 is purely consumed for excavating the ground, the peripheral surface of the casing pipe 10 and the ground. Some are consumed by friction with. Now, the rotational torque of the hydraulic motor 12 consumed by excavation of the ground by the cutter bit 26 is set as the excavation torque Tc, and the rotational torque of the hydraulic motor 12 consumed by the friction between the peripheral surface of the casing pipe 10 and the ground is the peripheral surface friction. If the torque is Tm, the cutter rotation torque T ′ is
It can be expressed by the following Equation 4. Formula 4 T ′ = Tc + Tm In this example, the circumferential surface friction torque Tm together with the self-sinking load Wp
Is measured, in which case the casing pipe 10
Is measured by calculating the cutter rotation torque T ′ by the mathematical formula 3 in a state of rotating and raising, as in the case of measuring the self-sinking load Wp. The cutter rotation torque T ′ thus measured is measured in a state where the casing bit 10 is lifted to separate the cutter bit 26 from the ground, that is, a state in which the ground cannot be excavated by the cutter bit 26. A state in which the rotational torque of the hydraulic motor 12 consumed for excavation of the ground does not occur, that is, Equation 4
It is measured in a state where the excavation torque Tc = 0. Therefore, since the cutter rotation torque T ′ = Tm, the cutter rotation torque T ′ thus measured accurately reflects the circumferential surface friction torque Tm generated when the ground is actually excavated and press-fitted with the casing pipe 10. It can be said that it is a thing. The cutter rotation torque T ′ is stored in a storage device so that it can be displayed by a display means, and can be output as needed, thereby forming a circumferential surface friction torque measuring device.

(E) Setting the set pressure of the pilot operated relief valve c) After calculating the self-sinking load Wp by the method shown in c), the judgment processing unit 51 operates the pilot to prevent the casing pipe 10 from running away. The set pressure of the relief valve 32, in other words, the set pressure of the pilot operated relief valve 32 for preventing the elevating frame 5 from dropping due to the self-sink load is calculated based on the self-sink load Wp, and the relief valve control unit 52 is operated. The relief pressure of the valve 32 is set through. The set pressure of the pilot operated relief valve 32 is equal to the set pressure of the electromagnetic proportional relief valve 34. Therefore, in order to set the set pressure of the pilot operated relief valve 32, the set pressure of the electromagnetic proportional relief valve 34 is Calculation is performed according to Equation 5. Formula 5 Pr = Wp / (So × N) + A In the above formula, Pr is the set pressure A of the electromagnetic proportional relief valve 34 is a margin value. The meanings of Wp, So, N are the same as those of Formula 2.
Since the characteristics of the electromagnetic proportional relief valve vary slightly depending on the product, a slight error occurs in the set pressure for each product. The margin value A is added to absorb such a control characteristic solid difference (command value-control characteristic of set pressure of the electromagnetic proportional relief valve) of the electromagnetic proportional relief valve, and is added to the set pressure of the electromagnetic proportional relief valve 34. Even if an error occurs, the value is set so that the casing pipe 10 can be prevented from running away.

In order to prevent the escape of the ground when excavating the ground with the casing pipe 10, the supporting force for supporting the casing gripping band 9 by the pressure on the cylinder side of the thrust cylinder 6, that is, the thrust cylinder 6 raises and lowers the frame 5.
The set pressure of the pilot operated relief valve 32 may be set so that the supporting force for supporting the at least equal to the self-sinking load Wp. Therefore, in the determination processing unit 51, the electromagnetic force for making the total sum of the supporting forces for supporting the casing gripping band 9 in cooperation with the four thrust cylinders 6 shown in FIG. 8 at least equal to the self-sinking load Wp. The set pressure of the set pressure of the proportional relief valve 34 may be calculated. In this example, when the set pressure Pr of the electromagnetic proportional relief valve 34 is determined, a margin value A is added to the supporting force for supporting the casing gripping band 9 by the thrust cylinder 6 and the supporting force is added. Is set to be slightly larger than the self-sinking load Wp, but the point is that the pilot-operated relief valve 32 operates in a range in which the supporting force for supporting the casing gripping band 9 by the thrust cylinder 6 does not fall below the self-sinking load Wp. An appropriate value may be selected in design so as to reduce energy loss.

(F) Calculation of the planned cutter rotation torque during excavation After the peripheral friction torque Tm is calculated by the method shown in 2), the judgment processing unit 51 damages the cutter bit 26 based on this peripheral friction torque Tm. The planned cutter rotation torque T during excavation, which is a set value of the rotation torque of the hydraulic motor 12 for enabling the cutter bit 26 to perform efficient excavation, is calculated according to the following Equation 6.

Equation 6 T = Ts + Tm In the previous equation, Ts is a set excavation torque which is a set value of the excavation torque Tc Is.

In this example, the set excavation torque Ts is
Taking into consideration the properties of the ground and the standard of the cutter bit 26, the prevention of damage to the cutter bit 26 is set as the highest priority, and at that time, consideration is given to enabling efficient excavation.

To prevent damage to the cutter bit 26,
Originally, of the rotational torque of the hydraulic motor 12, it is necessary to set the excavation torque Tc, which is a rotational torque purely consumed for excavation of the ground, to an appropriate value. However, conventionally, a method of actually measuring the circumferential surface friction torque Tm during the excavation work of the casing driver has not been established. Therefore, the ratio of the excavation torque Tc to the circumferential surface friction torque Tm of the rotation torque of the hydraulic motor 12 is calculated. The actual value of the excavation torque Tc could not be accurately grasped. Therefore, the expected cutter rotation torque T during excavation for preventing damage to the cutter bit 26 is empirically predicted and set in a rough estimate while taking into consideration construction conditions such as soil quality, soil removal status, and excavation depth. . On the other hand, in this method (3), the excavation torque Tc, which is the most important factor for preventing damage to the cutter bit 26 and performing efficient excavation, is directly set and then set. The planned cutter rotation torque T during excavation is set based on the set excavation torque Ts and the actual measurement value of the circumferential surface friction torque Tm. Since the value of the excavation torque Tc required to prevent damage to the cutter bit 26 and to perform efficient excavation has already been clarified from the research and achievements so far, using this method, the planned cutter during excavation is used. Rotation torque T
Can be set to an appropriate value according to the actual excavation work.

G) When the casing pipe 10 is lowered by the contraction of the thrust cylinder to the ground, the thrust cylinder 6 is re-extended and raised by the height Lst of the cutter bit 26 in the step of (2). It is lowered on the ground by the reduction of Lst. Such an operation is performed by the determination processing unit 51.
It starts by the command of. According to the command from the determination processing unit 51, both the hydraulic oil switching valve 32a and the pilot switching valve 33 are switched to the A position, and as a result, the electromagnetic proportional relief valve set in (e) is set. The pilot pressure of the set pressure Pr of 34 acts on the signal receiving portion of the pilot operated relief valve 32 through the pilot solenoid operated directional control valve 33, whereby the set pressure of the pilot operated relief valve 32 is the electromagnetic proportional relief valve. It is set to the same value as the set pressure of 34. In addition, in this step, the electromagnetic proportional flow controller 38 also operates, and the opening amount is adjusted in proportion to the output value of the electric signal from the determination processing unit 51 to adjust the pushing speed of the casing pipe 10 of the thrust cylinder 6. In this case, in this step (g), the determination processing unit 51 issues a command to minimize the pushing speed. At this time, the directional control valve 37 is in the neutral position
The position where it was finally operated in the process of].

Then, the pressure oil of the hydraulic pump 35 for the thrust cylinder is adjusted to the minimum flow rate by the electromagnetic proportional flow controller 38 and supplied to the rod side of the thrust cylinder 6, and the pressure oil on the cylinder side is pilot operated. While being kept at the set pressure Pr by the relief valve 32, it is discharged to the tank 44 through the electromagnetic switching valve 32a for hydraulic oil. As a result, the thrust cylinder 6 contracts at a speed according to the flow rate of the pressure oil passing through the electromagnetic proportional flow controller 38, and lowers the casing pipe 10 onto the ground at the lowest speed.
The reason why the casing pipe 10 is lowered at a low speed in this way is that a sharp load is applied to the cutter bit 26 when the casing pipe 10 contacts the ground, and
This is to prevent it from being damaged. In this way, when the casing pipe 10 descends on the ground due to the reduction of the thrust cylinder 6 by Lst, the determination processing unit 51 detects this by the stroke value of the thrust cylinder 6 input from the stroke sensor 45.

H) Calculation of cutter rotation torque during excavation After the casing pipe 10 descends on the ground, the excavation of the ground by the cutter bit 26 continues, and the judgment processing section 51 causes the cutter rotation torque during excavation. The calculation of T'is started. The cutter rotation torque T'during this excavation is calculated according to Equation 3 as in the case where the circumferential surface friction torque Tm is calculated in d). The cutter rotation torque T ′ during excavation is the actual value of the rotation torque of the hydraulic motor 12 required when excavating the ground with the cutter bit 26, and therefore the cutter rotation torque T ′ during excavation calculated by Equation 3 is used. In addition to the peripheral surface friction torque Tm, the excavation torque Tc, which is the rotation torque of the hydraulic motor 12 consumed in excavation of the ground, is naturally included in the inside.

(I) The casing pipe pushing speed control determination processing unit 51 continuously calculates the cutter rotation torque T'during such excavation when the ground is excavated by the cutter bit 26, and further, the calculation result is obtained. The planned cutter rotation torque T during excavation as a set value calculated in
And the deviation ΔT (ΔT = T−T ′) between the cutter rotation torque T ′ at the time of excavation as an actual value is calculated. Then, based on the deviation ΔT, a command value is output to the electromagnetic proportional flow controller 38 in accordance with the control function of FIG. 3 that defines the relationship between the deviation ΔT and the electromagnetic proportional flow control command value, and the opening amount is controlled to control the thrust cylinder. The feed rate of 6 to the rod side is controlled to control the pushing speed of the casing pipe 10. To be more specific about this point, FIG. 3 shows a graph of three different gradients. This is because the deviation ΔT and the electromagnetic field determined in consideration of the properties of the ground such as the hardness of the ground. This is a control function with the proportional flow control command value. Such a control function may be appropriately determined in design by the designer of the casing driver based on past know-how. In this example, since the cutter bit to be used is specified, only the property of the ground is considered, but when the cutter bit to be used is not specified, the performance of the cutter bit is also considered.

When the automatic excavation control is performed according to this example, an appropriate one suitable for the property of the ground is selected from the control functions shown in FIG. 3 and preset by the setting unit 50.
When the deviation ΔT becomes negative when excavating the natural ground, the cutter bit 26 is overloaded,
The command value to the electromagnetic proportional flow controller 38 is set to zero to stop pushing the casing pipe 10 by the thrust cylinder 6. On the contrary, when the deviation ΔT becomes positive,
Since the cutter bit 26 is still lightly loaded, the pushing speed of the casing pipe 10 is relatively increased by determining the command value to the electromagnetic proportional flow controller 38 according to a preset control function. As a result, in the casing pipe 10, the cutter rotation torque T ′ during excavation as an actual value is set as the preset cutter rotation torque T during excavation as a set value.
Thrust cylinder 6 to make the relationship close to
Therefore, the cutter bit 26 can be prevented from being damaged because it is pushed by and is always driven to rotate with an appropriate excavation torque Tc. The operation of the electromagnetic proportional flow controller 38 performed by the command value determined by the determination processing unit 51 is performed by the flow control unit 5
3 (see FIG. 5).

By performing such automatic excavation control,
Although the situation in which the cutter bit 26 is damaged is greatly improved, in this example, a device for preventing abnormal wear on the back surface of the cutter bit 26 is provided. Therefore, referring to FIGS. 3 and 4, This point will also be mentioned. When the pushing speed of the casing pipe 10 is increased when the deviation ΔT is positive, if the pushing speed is increased too much, as shown in FIG.
At the excavated ground, the chip 26a of the cutter bit 26 is
Since the tip portion of the cutter bit 26 is rapidly dug down, the portion other than the tip portion, that is, the back surface of the clearance angle portion 26b of the cutter bit 26 may be pressed against the unexcavated ground to cause abnormal wear. Therefore, in this example, the deviation ΔT
When the pushing speed of the casing pipe 10 is increased when is positive, the pushing speed of the casing pipe 10 is set by providing an upper limit value to the electromagnetic proportional flow control command value which is a command value of the determination processing unit 51 to the electromagnetic proportional flow control 38. I am trying to limit.

Now, the casing pipe 10 has a diameter of 100.
A cutter bit 26 was attached to the circumference of the tip of the casing pipe 10 using a 0 mm one, and the casing pipe 10 was set to 1 r. p. m
And the pushing speed of the casing pipe 10 at this time is V (mm / min).
Suppose Then, the casing pipe 10 is 1
While rotating, the tip of the tip 26a moves to 1000π
While drawing a line with a length of (mm) and turning, the ground is cut and the ground is pushed downward by a distance of V (mm). In other words, the gradient of the cutting locus at the tip of the tip 26a when excavating the ground with the cutter bit 26 can be said to be V / 1000π. The angle that defines the gradient of the cutting locus of the tip portion of the chip is referred to as the angle of the cutting bit cutting locus here, and is designated as θ ₁ . Now
Assuming V = 500 (mm / min), the angle θ ₁ of the cutter bit cutting locus in this case can be obtained by the following equation. θ ₁ = tan to ¹ (500 / 1000π) = 9.04 [d
Egg (degree)] Since the clearance angle θ of the cutter bit is generally 15 deg, in this case, the clearance angle portion 2 of the cutter bit 26.
The back surface of 6b is not pressed against the unexcavated excavated ground to cause abnormal wear.

However, when the angle θ _{1 of the} cutting bit cutting locus becomes larger than the clearance angle θ of the cutter bit 26, the clearance angle portion 26b of the cutter bit 26 comes into contact with the ground and its wear progresses. In consideration of this, the pushing speed V of the casing pipe 10 when the clearance angle θ of the cutter bit is 15 deg is calculated, and can be calculated by the following formula 7. Formula 7 V = tan (15) × 1000π = 872 (mm / mi
n) Therefore, if the pushing speed V of the casing pipe 10 does not exceed 872 (mm / min), the clearance angle portion 26b of the cutter bit 26 will not be back-weared, and therefore the electromagnetic proportional flow control command value. The upper limit of
The reduction speed of the thrust cylinder 6 is 872 (mm / mi
n). The upper limit of the electromagnetic proportional flow control command value is shown by a dotted line and a solid line connected to the positive coordinate surface in FIG.

In this example, the upper limit of the electromagnetic proportional flow control command value is calculated after setting the rotation speed of the casing pipe 10 to a fixed value (1 r.p.m). By storing a calculation formula for calculating the upper limit value in the judgment processing unit 51 and providing a means for measuring the rotation speed of the casing pipe 10, and inputting the actual value of the rotation speed to the judgment processing unit 51, The upper limit value of the proportional flow control command value may be calculated one by one using the calculation formula. When the excavated ground is a boulder layer or a ground where obstacles may appear, the cutter rotation torque T ′ changes drastically when excavating the ground with the cutter bit 26, and the cutter bit 26 May be suddenly loaded. In such a case, in this example, the gradient of the control function graph of FIG. 3 can be arbitrarily changed. Then, when there is a risk that a sudden load is applied to the cutter bit 26, the reaction of the pushing speed V of the casing pipe 10 with respect to the cutter rotation torque T ′ is reduced by decreasing the gradient of the graph of the control function in FIG. Is made dull to prevent a sudden load from being applied to the cutter bit 26.

(N) Stopping the thrust cylinder contraction When the thrust cylinder 6 contracts to the limit, the judgment processing unit 51
Detects this by the stroke value of the thrust cylinder 6 from the stroke sensor 45, sets the command value of the electromagnetic proportional flow controller 38 to zero, and stops the reduction of the thrust cylinder and stops the rotation of the hydraulic motor 12. Next, after the casing pipe 10 is released from the casing gripping band 9, the thrust cylinder 6 is again manually extended by Lo-Lst. ) Is repeated. Further, if necessary, a new casing pipe 10 having no cutter bit 26 is added to the casing pipe 10 that has been press-fitted. Thus, every time one press-fitting process is completed, the dynamic frictional force and the peripheral frictional torque Tm of the peripheral surface of the casing pipe 10 which increase with the progress of press-fitting of the casing pipe 10 are woven, and the electromagnetic proportional relief based on the self-sinking load Wp. Since the set pressure of the valve 34 and the planned cutter rotation torque T at the time of excavation are reviewed and reset, the set pressure of the pilot operated relief valve 32 for preventing the escape of the casing pipe 10 and the excavation work are appropriately performed. The setting value of the rotation torque of the hydraulic motor 12 is always set to an appropriate value according to the progress of press fitting of the casing pipe 10. As a result, it is possible to reliably reduce energy loss in the pilot operated relief valve 32, prevent escape of the casing pipe, and always perform proper excavation work with the casing driver.

In the steps a) to n) of the casing driver excavation control method described above, in the step a) of extending the thrust cylinder 6 and gripping the casing pipe 10, the pushing operation of the casing pipe 10 is started. This is a stage, and the point that a stroke that can be extended by the height of the cutter bit 26 when expanding the thrust cylinder 6 is left is the setting of the set pressure of the pilot operated relief valve 32 and the planned cutter rotation torque T during excavation. This is an operation for enabling calculation. Therefore, in this example, a) to f) for setting the set pressure of the pilot operated relief valve 32 and calculating the expected cutter rotation torque during excavation at the start stage of the pushing process of the casing pipe 10.
Since the above processes are combined so that the process for pushing the casing pipe 10 is performed, the setting pressure of the pilot operated relief valve 32 and the calculation of the cutter rotational torque during excavation can be calculated at the same time. Thus, the pushing operation of the casing pipe can be efficiently performed.

In this example, the pilot operated relief valve 3 is thus pressed during the pushing process of the casing pipe 10.
Although the process of setting the set pressure of 2 is integrated,
It is also possible not to combine such steps during the pushing step of the casing pipe 10. In that case,
First, the casing pipe 10 grasped by the casing grasping band 9 is raised by extending the thrust cylinder 6 so as to separate the cutter bit 26 from the ground, and is rotated by driving the hydraulic motor 12. Then, the cylinder side pressure Po and the rod side pressure Pt of the thrust cylinder 6 are measured in the state where the casing pipe 10 is raised and rotated in this way, and the self-sinking load Wp is calculated based on the measurement result. The set pressure of the pilot operated relief valve 32 is set based on the above, and similarly, the forward rotation pressure Ps and the reverse rotation pressure Pg of the hydraulic motor 12 are measured in a state where the casing pipe 10 is raised and rotated. Based on the rotational torque of the hydraulic motor 12, that is, the value related to the circumferential surface friction torque Tm and the set value related to the excavation torque, that is, the set excavation torque Ts, the planned cutter rotational torque during excavation that is the set value related to the rotational torque of the hydraulic motor 12 is obtained. Set T. Thereafter, the casing cylinder 10 is lowered onto the ground by contracting the thrust cylinder 6 in the same manner as the above-mentioned step g), and the casing pipe 10 is released from the casing gripping band 9. In this case, when the cutter bit 26 is slightly separated from the ground in the first step, the step of contracting the thrust cylinder 6 may be omitted and the step of immediately releasing the grip of the casing pipe 10 may be performed. Good. After the process of setting the set pressure of the pilot operated relief valve 32 is completed in this way, the pushing process of the casing pipe 10 is started. Therefore, the thrust cylinder 6 is extended so that the casing pipe can be pushed. The pipe is gripped by the gripping means, and thereafter, the casing pipe 10 is pushed in by the above steps (i) to (d).

Another example of the hydraulic circuit of the casing driver for carrying out each invention of this application will be described with reference to FIG. The hydraulic circuit of FIG. 6 is different from the hydraulic circuit of FIG. 1 only in the method of adjusting the flow rate of the pressure oil supplied to the rod side of the thrust cylinder 6, and is otherwise basically the same as that of FIG. Does not change. That is, when adjusting the flow rate of pressure oil supplied to the rod side of the thrust cylinder 6, in the hydraulic circuit of FIG. 1, the flow rate of pressure oil supplied to the rod side of the thrust cylinder 6 is directly adjusted by the electromagnetic proportional flow controller 38. However, in the hydraulic circuit of FIG. 6, a part of the pressure oil supplied to the rod side of the thrust cylinder 6 is made to escape to the tank 44, and the flow rate of the pressure oil to be made to escape is indirectly adjusted. I am trying to adjust it.

Therefore, the structure of the circuit which is different from the hydraulic circuit of FIG. 1 will be specifically described. The hydraulic circuit of FIG. 6 is the same as the hydraulic circuit of FIG. 1, except that an oil passage provided in parallel with the direction switching valve 37 and provided with an electromagnetic proportional flow controller 38 and an electromagnetic switching valve 32 for hydraulic oil.
Instead of eliminating the oil passage provided with a, an oil passage is provided for allowing a part of the pressure oil sent from the hydraulic pump 35 to the direction switching valve 37 to escape to the tank 44, and the electromagnetic proportional flow controller 38 is provided in this oil passage. I am trying to provide it. By the hydraulic circuit of FIG. 6, the thrust cylinder 6 is contracted and the casing pipe 1
When performing the press-fitting step of 0, the directional control valve 37 is used when performing the automatic operation as in the case of performing the manual operation.
Is switched to the A position and pressure oil is supplied to the rod side of the thrust cylinder 6. In that case, this electromagnetic proportional flow control 3
Reference numeral 8 designates a flow rate of pressure oil supplied to the rod side of the thrust cylinder 6 by adjusting a flow rate of releasing a part of the pressure oil sent to the direction switching valve 37 to the tank 44 according to a command from the determination processing section 51. . In the example of FIG. 6, a deviation Δ between the planned cutter rotation torque T during excavation and the cutter rotation torque T ′ during excavation
The control function that defines the relationship between T (ΔT = T−T ′) and the electromagnetic proportional flow control command value is as shown in FIG. 7. Therefore, in the example of FIG. 6, based on the deviation ΔT, a command value is output to the electromagnetic proportional flow controller 38 according to the control function of FIG. 7 to control the opening amount thereof, similar to the control method described in the above re). Controlling the feed rate of the thrust cylinder 6 to the rod side to control the pushing speed of the casing pipe 10 so that the cutter rotation torque T ′ during excavation approaches the planned cutter rotation torque T during excavation. Becomes

In this way, the planned cutter rotation torque T during excavation as the set value is different from the cutter rotation torque T ′ during excavation.
When pushing the casing pipe with the thrust cylinder so as to bring the set value closer to each other, in the example described above, the pushing speed of the casing pipe 10 is controlled by adjusting the flow rate on the rod side of the thrust cylinder 6. However, the pushing force of the casing pipe 10 may be controlled by adjusting the pressure on the rod side of the thrust cylinder 6. In that case, for example, instead of eliminating the electromagnetic proportional flow controller 38 in FIG. 6, a relief valve capable of changing the set pressure in multiple stages may be provided on the secondary side of the direction switching valve 37.

However, if the pushing speed of the casing pipe 10 is controlled by adjusting the flow rate on the rod side of the thrust cylinder 6 as in the example shown in FIG. 1 and FIG. More accurate control when pushing with. To describe this point, the relationship between the pushing speed V of the casing pipe 10 and the excavation torque Tc can be expressed by the following Equation 7.

Equation 7 Tc = α × (σ × B × V / R) × D / 2 In the above equation, α is the cutting resistance coefficient, σ is the uniaxial compressive strength of the excavated ground, B is the cutter width, and R is the casing pipe. Since the number of rotations of 10 and D are the excavation diameter, the casing pipe 10
When the casing driver is controlled to excavate at a constant rotational speed, the factors become constants, and the pushing speed V of the casing pipe 10 and the excavation torque Tc are in a proportional relationship. For this reason, if the pushing speed of the casing pipe 10 is controlled by adjusting the flow rate on the rod side of the thrust cylinder 6, the casing cylinder 10 can be more accurately controlled when it is pushed by the thrust cylinder 6. Excavation control of the casing driver for preventing damage to the bit 26 and performing efficient excavation can be achieved more reliably.

When setting the set pressure of the pilot operated relief valve 32 for preventing the casing pipe 10 from running away, in the example shown in the flow chart of FIG. 2, the self-sinking load Wp is calculated according to the equation (2). C) process,
(E) The preset pressure of the pilot operated relief valve 32 is set by calculating the preset pressure Pr of the electromagnetic proportional relief valve 34 based on the self-sinking load Wp according to the equation (5).
The setting pressure Pr of the electromagnetic proportional relief valve 34 is set in the thrust cylinder 6 separately.
When the pressure Po on the cylinder side and the pressure Pt on the rod side of the thrust cylinder 6 are uniquely determined, the pressure can be directly set without the step c). Therefore, the process itself of setting the set pressure of the pilot operated relief valve 32 is not essential to the present invention. In short, the supporting force for supporting the gripping means by the pressure Po on the cylinder side of the thrust cylinder 6 is the thrust force. Pressure Po on the cylinder side of cylinder 6 and pressure P on the rod side
The set pressure of the pilot operated relief valve 32 may be set by an appropriate method so as to obtain a result that does not fall below the self-sinking load Wp obtained based on t. When controlling the drive of the thrust cylinder 6, in the example shown in the flowchart of FIG. 2, the planned excavating cutter rotation torque T obtained by adding the peripheral surface friction torque Tm to the set excavation torque Ts.
Cutter rotation torque T'as an actual value
Is controlled to approach the set value, but the set excavation torque Ts is set to the set value, and the value obtained by subtracting the peripheral friction torque Tm from the cutter rotation torque T ′ is controlled to approach the set value. Well, the point is that the set excavation torque Ts
It suffices that the result is controlled so that the actual value of the rotational torque T ′ of the hydraulic motor approaches the sum of the value of the above value and the value of the circumferential surface friction torque Tm.

In the above-mentioned example, both the cylinder side pressure Po and the rod side pressure Pt of the thrust cylinder 6 are measured. However, these cylinder side pressure Po and rod side pressure Pt are the thrust cylinder 6 The pressure Pt on the rod side of the thrust cylinder 6 becomes a value close to 0 when it is not driven. Therefore, only the cylinder side pressure Po of the thrust cylinder 6 may be measured, and the self-precipitation load Wp may be obtained by treating the rod side pressure Pt of the thrust cylinder 6 as 0 or a constant close to 0.
Further, in order to measure the driving pressure of the hydraulic motor, which is the differential pressure between the forward rotation pressure Ps and the reverse rotation pressure Pg of the hydraulic motor, the hydraulic motor 1
Although both the normal rotation pressure Ps and the reverse rotation pressure Pg of 2 are measured, since the reverse rotation pressure Pg of the hydraulic motor 12 is usually a small value close to 0, only the normal rotation pressure Ps of the hydraulic motor 12 is measured. At the same time, the reverse rotation pressure Pg of the hydraulic motor 12 may be treated as 0 or a constant close to 0 to measure the driving pressure of the hydraulic motor.

In the example described above, the casing pipe 10
An example in which the casing gripping band 9 is used as the gripping means for gripping is shown. In this gripping means, a wedge-shaped chuck member is fitted in the gap between the ring-shaped rotating body and the casing inserted therein. There is also a chuck device that grips the casing by a wedge action. Since this chuck device performs the same function as the casing gripping band 9, such a chuck device may be used as the gripping means, The type of gripping means used in the present invention does not matter. Also,
Although the electromagnetic proportional flow controller 38 is used as a means for changing the pushing speed of the thrust cylinder 6, the flow rate of the pressure oil supplied to the rod side of the thrust cylinder 6 is adjusted. A pump may be used to adjust the flow rate of the pressure oil.

[0074]

As is apparent from the above description, the first invention of this application to the sixth invention of this application are:
Since the means 1) to 6) described in the section “Means for solving the problems” are respectively adopted, according to each of these inventions, a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. The present invention provides a casing driver excavation control technique that can be used in a casing driver equipped with, and can reduce the energy loss in the relief valve and prevent the casing pipe from running away. In that case, particularly in the first invention and the fourth invention of this application, the relief valve is set at the start stage of the casing pipe pushing step started by the extension of the thrust cylinder and the gripping of the casing pipe. Since the series of steps from the first step to the third step are combined so as to be integrated, and these steps can be performed along the path of performing the pushing step, the pushing operation of the casing pipe can be performed efficiently. Can be done on a regular basis. Further, particularly in the fourth invention, the fifth invention and the sixth invention of this application, the set value relating to the rotational torque of the hydraulic motor is used to prevent damage to the cutter bit of the casing pipe and to perform efficient excavation. Based on the excavation torque, which is the most important factor above, it can be set to an appropriate value according to the actual excavation work. And more efficient excavation can be achieved more reliably than before.

When the fourth invention and the fifth invention of the present application are embodied, particularly when the means described in claim 6 is adopted, the case where the casing pipe is pushed in by the thrust cylinder The control can be performed more accurately, and the excavation control of the casing driver for preventing the damage of the cutter bit and performing the efficient excavation can be achieved more reliably. The same applies when the sixth invention of the present application is embodied, particularly when the means described in claim 9 of the claims is adopted. The seventh invention of this application adopts the means of 7) shown in the section of means for solving the problems. Therefore, according to the seventh invention, the thrust is applied at the time of excavating the casing pipe. A method for measuring the self- sinking load of a casing driver, which can accurately measure the self- sinking load acting on a cylinder, is obtained.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram showing an example of a hydraulic circuit of a casing driver for explaining each invention of this application.

FIG. 2 is a flowchart showing an example of a casing driver excavation control method for explaining each invention of the present application.

FIG. 3 is a diagram showing a control function useful for control in the hydraulic circuit diagram of FIG. 1 by the casing driver excavation control method and the excavation control device of the invention of this application.

FIG. 4 is a conceptual diagram showing a relationship between a clearance angle of a cutter bit and a cutting locus for explaining the significance of the control function of FIG.

FIG. 5 is a block diagram showing an example of an excavation control device for a casing driver for explaining each invention of the present application.

FIG. 6 is a hydraulic circuit diagram showing another example of a hydraulic circuit of a casing driver for explaining each invention of the present application.

7 is a diagram showing control functions useful for control in the hydraulic circuit diagram of FIG. 6 by the casing driver excavation control method and excavation control device of the invention of this application.

FIG. 8 is a plan view showing an example of a casing driver that has been generally used conventionally.

9 is a right side view of FIG.

FIG. 10 is a front view of FIG.

FIG. 11 is an explanatory diagram of a self- sinking load that acts on a thrust cylinder during excavation with a casing driver.

[Explanation of symbols]

4 base frame 5 Lifting frame 6 Thrust cylinder 8 rotating bodies 9 Casing grip band 10 casing 11 band cylinder 12 Hydraulic motor 13 Pinion 26 cutter bits 26a Cutter bit 26 tip 26b Relief angle of cutter bit 26 30a, 30b Pressure sensor for hydraulic motor 31a, 31b Pressure sensor for thrust cylinder 32 Pilot operated relief valve 32a Electromagnetic switching valve for hydraulic oil 33 Electromagnetic switching valve for pilot 34 Electromagnetic proportional relief valve 35 Hydraulic pump for thrust cylinder 36 Power Source (For Thrust Cylinder) 37 Electromagnetic Directional Switching Valve 38 Electromagnetic proportional flow control 38a Electromagnetic variable throttle valve 38a 40 Hydraulic pump for hydraulic motor 41 Power source (for hydraulic motor) 43 Electromagnetic directional control valve 44 oil tank 45 Stroke sensor 50 setting section 51 Judgment processing unit 52 Relief valve control unit 53 Electromagnetic proportional flow control unit

Front page continuation (72) Inventor Hiroshi Kusumi, 650 Kintatemachi, Tsuchiura City, Ibaraki Prefecture Hitachi Construction Machinery Co., Ltd., Tsuchiura Plant (72) Inventor Hajime Ozawa, 650, Jinmachicho, Tsuchiura City, Ibaraki Prefecture Hitachi Construction Machinery Co., Ltd., Tsuchiura Plant (72) Inventor Toshihisa Ishii, 650 Kazunachi-cho, Tsuchiura-shi, Ibaraki, Hitachi Construction Machinery Engineering Co., Ltd. (72) Inventor Yoshiaki Hirose, 650, Jinmachi-cho, Tsuchiura-shi, Ibaraki, Hitachi Construction Machinery Engineering Co., Ltd. (56) References Special Kaihei 7-310488 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21B 44/00 E02D 7/22 E21B 7/20

Claims (11)

(57) [Claims] 1. A gripping means for gripping a casing pipe, a thrust cylinder capable of supporting and lifting the gripping means, a motor for rotationally driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. When excavating the ground with a casing pipe having a cutter bit at the tip using a provided casing driver, in a casing driver excavation control method for controlling so as to prevent the casing pipe from running away, the cutter bit can be separated from the ground The first step of extending the thrust cylinder so as to leave a stroke and holding the casing pipe by the holding means, and raising the casing pipe held by the holding means by extending the thrust cylinder so as to separate the cutter bit from the ground. Along with driving the motor And the second step of rotating the casing pipe and measuring the pressure on at least the cylinder side of the pressure on the cylinder side and the pressure on the rod side of the thrust cylinder in the state where the casing pipe is raised and rotated in this way, and based on the measurement result After passing through the third step of setting the set pressure of the relief valve so that the supporting force for supporting the gripping means does not fall below the self-settling load obtained by the pressure on the cylinder side of the thrust cylinder, the casing pipe is driven by the motor. A method for controlling excavation of a casing driver, characterized in that the ground is excavated by pushing in with a thrust cylinder while rotating. 2. A gripping means for gripping a casing pipe, a thrust cylinder capable of supporting the gripping means and moving up and down, a motor for rotationally driving the gripping means, and a relief valve capable of adjusting pressure on the cylinder side of the thrust cylinder. In the excavation control method for a casing driver, which controls to prevent escape of the casing pipe when excavating the ground with a casing pipe having a cutter bit at the tip using the provided casing driver, the casing pipe gripped by the gripping means. To raise the cutter bit by extending the thrust cylinder so as to separate the cutter bit from the ground, and to rotate it by driving the motor.
And the pressure of at least the cylinder side of the pressure on the cylinder side of the thrust cylinder and the pressure on the rod side in the state where the casing pipe is raised and rotated in this way, and the self-sinking load obtained based on the measurement result. The second step of setting the set pressure of the relief valve so that the supporting force for supporting the gripping means by the pressure on the cylinder side of the thrust cylinder does not fall, and after releasing the gripping of the casing pipe by the gripping means, After the third step of extending the thrust cylinder so that the casing pipe can be pushed and holding the casing pipe by the holding means,
An excavation control method for a casing driver, characterized in that a casing pipe is pushed by a thrust cylinder while being rotated by a motor to excavate the ground. 3. A gripping means for gripping the casing pipe, a thrust cylinder capable of supporting and lifting the gripping means, a motor for rotationally driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. When excavating the ground with a casing pipe having a cutter bit at the tip using the provided casing driver, the pressure on the cylinder side of the thrust cylinder in the casing driver excavation control device that controls to prevent the casing pipe from running away. And a thrust cylinder pressure measuring means for measuring at least the cylinder side pressure of the rod side pressure, and a casing driver control mechanism for inputting the measurement result relating to the thrust cylinder pressure by the pressure measuring means. Control of this casing driver The mechanism extends the thrust cylinder so that the cutter bit is separated from the ground, and the self-sinking load obtained based on the measurement result by the pressure measuring means of the thrust cylinder, which is measured with the motor being rotated, is measured on the cylinder side of the thrust cylinder. And a control function of controlling so as to set the set pressure of the relief valve so that the supporting force for supporting the gripping means does not fall under the pressure of 1. The excavation control device for a casing driver. 4. A gripping means for gripping a casing pipe, a thrust cylinder capable of supporting the gripping means and moving up and down, a hydraulic motor for rotationally driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. In a casing driver excavation control method for controlling the casing pipe to prevent escape of the casing pipe when excavating the ground with a casing pipe having a cutter bit at the tip, the cutter bit is separated from the ground. The first step of extending the thrust cylinder so as to leave a stroke to obtain and holding the casing pipe by the holding means, and raising the casing pipe held by the holding means by extending the thrust cylinder so as to separate the cutter bit from the ground. Of the hydraulic motor The second step of rotating by driving, and at least the cylinder side pressure of the cylinder side pressure and the rod side pressure of the thrust cylinder in the state where the casing pipe is raised and rotated in this way, are measured. The set pressure of the relief valve was set so that the self-sinking load obtained based on this did not fall below the supporting force that supports the gripping means due to the pressure on the cylinder side of the thrust cylinder, and the casing pipe was also raised and rotated. In the state, the driving pressure of the hydraulic motor is measured, the value related to the rotational torque of the hydraulic motor is obtained based on the measurement result, and the third step of measuring the value related to the circumferential friction torque, and the casing pipe is rotated by the hydraulic motor. While pushing it with the thrust cylinder to excavate the ground, at that time, set the excavation torque to the preset value. Push the casing pipe with the thrust cylinder so that the actual value related to the rotational torque of the hydraulic motor obtained based on the drive pressure of the hydraulic motor approaches the sum of the set value and the value related to the frictional torque on the surface. In the fourth step, the casing driver excavation control method is characterized in that the casing driver is used to control the excavation of the ground performed by the casing pipe. 5. A gripping means for gripping a casing pipe, a thrust cylinder capable of supporting the gripping means and ascending / descending, a hydraulic motor for rotationally driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. In the excavation control method of a casing driver, which controls to prevent escape of the casing pipe when excavating the ground with a casing pipe having a cutter bit at the tip, using the casing driver provided with The first step in which the pipe is raised by extending the thrust cylinder so as to separate the cutter bit from the ground and is rotated by driving the motor, and the casing pipe on the cylinder side of the thrust cylinder is raised while the casing pipe is raised and rotated. Pressure and rod side At least the pressure on the cylinder side of the pressure of the relief valve is measured so that the self-sinking load obtained based on the measurement result does not fall below the supporting force that supports the gripping means with the pressure on the cylinder side of the thrust cylinder. In addition to setting the set pressure, similarly, the driving pressure of the hydraulic motor is measured with the casing pipe being raised and rotated, and the value related to the rotational torque of the hydraulic motor is obtained based on the measurement result to determine the peripheral friction torque. A second step of measuring the value, and a third step of releasing the grip of the casing pipe by the gripping means, then extending the thrust cylinder so that the casing pipe can be pushed, and gripping the casing pipe by the gripping means. While excavating the ground by pushing the casing pipe with a thrust cylinder while rotating it with a hydraulic motor, Casing pipe so that the actual value related to the rotational torque of the hydraulic motor obtained based on the driving pressure of the hydraulic motor approaches the sum of the set value related to the excavation torque and the value related to the frictional surface friction torque. And a fourth step of pushing in the thrust cylinder with the thrust cylinder, the excavation control method for the casing driver is performed by using the casing driver to control the excavation of the ground performed by the casing pipe. 6. The pushing speed of the casing pipe is controlled by adjusting the flow rate on the rod side of the thrust cylinder when pushing the casing pipe with the thrust cylinder in the fourth step. Alternatively, the casing driver excavation control method according to claim 5. 7. The pushing force of the casing pipe is controlled by adjusting the pressure on the rod side of the thrust cylinder when pushing the casing pipe with the thrust cylinder in the fourth step. Alternatively, the casing driver excavation control method according to claim 5. 8. A gripping means for gripping a casing pipe, a thrust cylinder capable of supporting the gripping means and moving up and down, a hydraulic motor rotatably driving the gripping means, and a relief valve capable of adjusting the pressure on the cylinder side of the thrust cylinder. When excavating the ground with a casing pipe having a cutter bit at the tip using a casing driver equipped with, the excavation control device of the casing driver that controls the casing pipe to prevent escape of the casing pipe causes the cutter bit to separate from the ground. Detecting means that can detect that the pressure is on, the thrust cylinder pressure measuring means that measures at least the cylinder side pressure of the cylinder side pressure and the rod side pressure of the thrust cylinder, and the drive pressure of the hydraulic motor. With the drive pressure measuring means and the thrust cylinder pressure measuring means The relief valve setting means for setting the set pressure of the relief valve so that the supporting force for supporting the gripping means does not fall below the self-sinking load obtained based on the measurement result The measurement result of the driving pressure measuring means is input, and the rotation torque calculating means for calculating a value relating to the rotation torque of the hydraulic motor at the time of rotation of the hydraulic motor based on the measurement result and the cutter bit are separated from the ground. Is detected by the detecting means, the sum of the value relating to the rotating torque of the hydraulic motor calculated by the rotating torque calculating means and the preset value relating to the excavating torque is set to the rotating torque when excavating the ground with the casing pipe. The thrust series should be set so that the actual values for the rotational torque of the hydraulic motor calculated by the calculation means are close to each other. Excavation control system for a casing driver, characterized in that a thrust cylinder control means for controlling driving of da. 9. The thrust cylinder control means, when controlling the drive of the thrust cylinder, adjusts the rod cylinder side flow rate of the thrust cylinder to control the pushing speed of the casing pipe. A casing driver excavation control device as described. 10. The thrust cylinder control means, when the drive of the thrust cylinder is controlled, the pressure on the rod side of the thrust cylinder is adjusted to control the pushing force of the casing pipe. A casing driver excavation control device as described. 11. A cutter bit is provided at a tip of a casing driver using a gripping means for gripping a casing pipe, a thrust cylinder capable of supporting the gripping means and moving up and down, and a motor for rotationally driving the gripping means. When gripping the casing pipe that it has with the gripping means,
A method for measuring a self- sinking load of a casing driver, which measures a self- sinking load acting on a thrust cylinder, in which a casing pipe gripped by gripping means is lifted by extending the thrust cylinder so as to separate the cutter bit from the ground, and the motor is driven. And the first step of rotating the casing pipe in this manner, and at least the cylinder side pressure of the cylinder side pressure and the rod side pressure of the thrust cylinder are measured in the state where the casing pipe is rotated and raised, and these measurement results are shown. A method for measuring a self-sinking load of a casing driver, characterized in that the self-sinking load acting on the thrust cylinder is measured by a second step of calculating a value relating to the self-sinking load based on the above.