JP3306328B2 - Pipe propulsion machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of body parts which are connected to be tiltable, a cutter head provided on the front body part, and a plurality of direction correcting jacks which can tilt the front body part. And a tip conductor provided with a relief means for relieving the pressure oil in the cylinder to the direction correcting jack,
The present invention relates to a pipe propulsion device including a propulsion jack for propelling a succeeding pipe connected to a trunk portion on a rear end side.

[0002]

2. Description of the Related Art As a method of embedding a small-diameter pipe having a diameter of 800 mm or less in the ground, a method called a pipe propulsion method has been generally known. In this pipe propulsion method, subsequent pipes composed of fume pipes and the like are sequentially connected behind a leading conductor having a cutter head, and these subsequent pipes are propelled by a main push jack as a propulsion jack installed in a starting shaft. In this method, the ground in front is excavated with a leading conductor, and each subsequent pipe is sequentially pushed into the ground and buried. The pipe propulsion device is a device configured with a leading conductor and a main push jack in order to carry out such a pipe propulsion method. This pipe propulsion machine, whether to do so-called straight construction where the subsequent pipe is buried straight in the ground, or to perform so-called curved construction where the subsequent pipe is buried in the ground while curving the subsequent pipe, It is desirable to always appropriately adjust the propulsion direction so that the leading conductor can be dug along a predetermined path. For this reason, a tube propulsion device generally provided with a direction correcting jack so that the direction of the leading conductor can be corrected during propulsion is generally used. The present invention seeks to improve the tube propulsion device provided with such a direction correcting jack. Therefore, a conventional pipe propulsion machine to be improved by the present invention will be described more specifically below.

[0003] This conventional pipe propulsion machine usually includes a plurality of trunks in which a leading conductor is divided into, for example, a front trunk, a middle trunk, and a rear trunk, and these trunks have adjacent ends. They are connected to be tiltable with each other. At the front end of the plurality of trunks, a ground excavation cutter head for excavating the ground is provided at the front end. In addition, the front body portion is connected to the rear body portion by a direction correcting jack, and can be tilted by operating the direction correcting jack. The connecting mechanism having a spherical bearing such as a universal joint so that the direction correcting jack can swing in any direction with respect to each body when attached to the body at the front end and the body behind the jack. It is attached by. Usually, three such direction correcting jacks are provided at substantially equal intervals in the circumferential direction of the leading conductor, and the stroke at the front end side of the leading conductor is tilted in any of up, down, left, and right directions due to a difference in these strokes. The tilt direction in the three-dimensional space can be uniquely determined.

At the rear end of the rear trunk, which is the last part of the front conductor,
Subsequent pipes such as fume pipes that are buried pipes are connected in sequence, and a starting shaft, which is the starting point of pipe burial, is constructed at the position corresponding to the last part of the following pipes. A main push jack has been installed as a propulsion jack for propelling the trailing pipe. In the pipe propulsion method, when pushing and embedding the succeeding pipe, it is necessary to penetrate the succeeding pipe while consolidating the ground at the front, and also to promote a large number of subsequent pipes. Extremely large thrust can be generated compared to the modified jack.
Therefore, when a large propulsive force of such a primary push jack acts on the leading conductor, a large ground reaction force based on the propulsive force acts on the direction correcting jack. further,
The reaction force of the rotating force of the cutter head and the earth pressure of the ground also act on the direction correcting jack, and there is a possibility that an excessively large external force as described above acts on the jack.

Therefore, when such an excessive external force acts on the direction correcting jack in a state in which the pressure oil is introduced into the cylinder, that is, in a state where the oil is extended beyond the contraction limit, the hydraulic pressure in the cylinder rapidly increases. It may be damaged. Because of this, the direction correction jack
When the pressure oil in the cylinder exceeds a predetermined pressure, a relief valve is provided to relieve the pressure oil, so that if an excessive external force is applied, the pressure oil in the cylinder escapes to prevent damage. is there. This direction-correcting jack shrinks due to an excessive external force acting on one of the jacks, or receives a reaction force of the rotating force of the cutter head or a lateral external force, for example, an external force that allows the leading conductor to escape in the lateral direction due to a large obstacle. May act and stretch. For this reason, the direction correcting jack is provided with the relief valve on both the contraction side and the extension side. This type of direction-correcting jack, when pressurized oil is introduced into the cylinder and the hydraulic pressure is maintained, and when the compressed oil is relieved and contracted to the contraction limit, that is, the stroke becomes zero, the cylinder and the piston It is designed to be held mechanically. In this case, the gap between the body on the tip side of the leading conductor and the body behind the body is also mechanically held.

On the other hand, even if the direction correcting jack is contracted to the contraction limit and mechanically held as described above, the cylinder and the piston rod may be damaged if an excessive external force acts. In order to prevent such damage of the direction correcting jack, there is a conventional pipe propulsion machine in which the main pushing by the main pushing jack is stopped when the rotation of the cutter head is stopped during the operation of the main pushing jack. . That is, conventionally, since the driving torque of the cutter head and the cutting performance of the cutter were not so high, when an excessive external force acting on the leading conductor was applied to damage the direction correcting jack, the cutter head was damaged before the direction correcting jack was damaged. Stops, so if the main push by the main push jack stops for the first time when the cutter head stops,
The damage of the direction correction jack was prevented. For this reason, the conventional pipe propulsion apparatus has been provided with an interlock for detecting the stop of the cutter head when operating the main pushing jack and stopping the propulsion of the subsequent pipe by the main pushing jack.

[0007]

However, recently, it has become clear from the fact that a pipe propulsion machine has been developed which can be applied to hard ground such as a boulder layer and a rocky ground containing cobblestones. The cutting performance of
The cutter head continues to rotate without stopping even when an excessive external force that damages the direction correcting jack acts on the leading conductor. Therefore, in the conventional pipe propulsion device provided with the above-mentioned interlock, it is no longer possible to prevent an excessive external force from acting on the direction correcting jack at the time of propulsion of the subsequent pipe and damaging the direction correcting jack.

SUMMARY OF THE INVENTION The present invention is directed to solving the problems encountered in such conventional pipe propulsion machines, and its technical problem is to prevent the direction-correcting jack from being damaged by an external force acting when the subsequent pipe is propelled. It is to provide a pipe propulsion device that can be used.

[0009]

The technical objects of the present invention are: 1) a plurality of trunks which are tiltably connected to each other and a cutter head for ground excavation provided on a trunk at the front end and a front end. A plurality of direction-correcting jacks that can connect and tilt the torso with respect to the rear torso, and when the pressure oil in the cylinder exceeds a predetermined pressure, the direction-correcting jack supplies the pressure oil. In a pipe propulsion device comprising a leading conductor provided with a relief means for relief and a propulsion jack for propelling a succeeding pipe connected to the trunk on the rear end side, a `` shrinkage for determining a shrinkage limit of the direction correcting jack '' Set the limit setting,
The propulsion jack stops the propulsion of the subsequent pipe when it is determined that at least one of the plurality of direction correction jacks has contracted until the contraction limit set value is reached. "2) Each other A plurality of body parts that are tiltably connected, a cutter head for ground excavation provided on the body part on the front end side, and a plurality of body parts that can be connected to the body part on the front end side and tilted with respect to the body part on the rear side A lead conductor provided with a relief means for relieving the pressure oil in the cylinder when the pressure oil exceeds a predetermined pressure, and the direction correction jack is connected to the trunk at the rear end side. And a propulsion jack for propelling the succeeding pipe, wherein `` at least one of the plurality of directional correction jacks is reduced or extended in a state where it is not operated. The propulsion jack stops the propulsion of the succeeding pipe when it is determined that the propulsion jack has been determined. 3) A plurality of trunks that are tiltably connected to each other and a ground excavation provided on the front end trunk. A plurality of direction correcting jacks that can connect and tilt the cutter head and the front end body with respect to the rear body, and when the pressure oil in the cylinder exceeds a predetermined pressure, A leading conductor provided with a relief means for relieving the pressurized oil, and a propulsion jack for propelling a subsequent pipe connected to the rear end of the body, and the propulsion jack is used when the rotation of the cutter head is stopped. In a pipe propulsion device provided with an interlock for stopping the propulsion of a succeeding pipe, a cutter torque threshold value, which is a limit value of a driving torque of the cutter head for stopping the cutter head, is set to a cutter head. When the cutter head is driven to rotate, the drive torque is set to be smaller than the value related to the drive torque of the cutter head when the cutter head is stopped by an external force, and to be decreased in accordance with the increase in the amount of tilt of the front end body. When it is determined that the value related to the torque of the cutter head has reached the threshold value of the cutter torque, the rotation drive of the cutter head is stopped, so that the propulsion jack stops the propulsion of the subsequent pipe through the interlock. It is achieved by any of the above.

[0010] The tube propulsion device of the first invention of this application is:
Since the technical means described in 1) above is employed, when at least one of the plurality of direction correcting jacks contracts until the contraction limit set value is reached, the propulsion jack stops propulsion of the subsequent pipe. As a result, when propelling the subsequent pipe, the propulsion can only be performed with the direction correcting jack held hydraulically, without propelling with the direction correcting jack mechanically held between the cylinder and the piston.
The direction-correcting jack is not damaged by excessive external forces acting on the propulsion of the following pipe. When an excessive external force acts on the direction-correcting jack, the hydraulic oil in the cylinder is reduced or expanded by a relief valve, but the pipe propulsion device according to the second invention of this application is described in 2) above. When at least one of the plurality of direction correcting jacks is contracted or extended while not operated, the propulsion jack stops the propulsion of the subsequent pipe. As a result, the propulsion jack immediately stops the propulsion of the subsequent pipe at an early stage in which the hydraulic pressure holding of the direction correcting jack is not maintained, so that the direction correcting jack is similar to the pipe propeller of the first invention of this application. The jack will not be damaged by excessive external forces acting on the propulsion of the trailing pipe. On the other hand, in the case of the pipe propulsion device, if the direction correcting jack relieves the pressure oil due to the operation of the relief valve and the hydraulic pressure is no longer maintained, the trunk portion on the front end side fluctuates and the propulsion direction is not determined. If the subsequent pipe is continuously propelled in this state, it may be propelled out of the predetermined route. However, in the pipe propulsion device according to the second invention of this application, when the relief valve operates and the direction correcting jack expands and contracts, the propulsion jack immediately stops the propulsion of the subsequent pipe. But
The pipe propulsion device can be prevented from being propelled out of the predetermined route as much as possible. The pipe propulsion device according to the third invention of this application employs the technical means described in 3) above, and sets the threshold value of the cutter torque, particularly when the cutter head stops due to an external force. Since the setting is made smaller than the value related to the driving torque, when the value related to the torque of the cutter head reaches the threshold value of the cutter torque during the rotation driving of the cutter head, the cutter head is stopped by an external force. Even if it is not, the rotation drive of the cutter head is artificially stopped, and the propulsion jack stops the propulsion of the subsequent pipe through the interlock. Therefore, the interlock stops the cutter head before the direction correction jack is damaged, even if the cutter head is installed on a tube propulsion machine that has excellent cutter torque performance and cutting performance and is hard to stop due to external force. Then, the propulsion jack stops the propulsion of the subsequent pipe. On the other hand, the direction-correcting jack acts on the direction-correcting jack in a state where the reaction force based on the propulsion force of the propulsion jack increases in accordance with the increase in the amount of tilt of the trunk portion on the front end side. In the pipe propulsion device of the third invention,
The technical means of the above 3) is employed, and the threshold value of the cutter torque is not set uniformly regardless of the tilting amount of the front end body portion, and the threshold value of the cutter torque is increased according to the tilting amount. Since it is set so as to decrease, it is possible to prevent the direction correcting jack from being damaged irrespective of the amount of tilt.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment
The second, third, and third inventions employ different technical means, but both have the same industrial application field and the same problem to be solved. Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2 and 3 showing concrete examples showing how each invention of the present application is actually embodied. I do. FIG.
FIG. 2 is a system configuration diagram of a direction correcting jack protection device in a pipe propulsion device according to a first embodiment of the present invention.
FIG. 3 is a flowchart of the direction correcting jack protection device of FIG. 1, and FIG. 3 is a system configuration diagram of the direction correcting jack protection device in the pipe propulsion device according to the second embodiment of the present invention.
The pipe propulsion devices of the first embodiment and the second embodiment of the present invention each include a plurality of trunks that are tiltably connected to each other and a ground excavation provided on a front end trunk. A plurality of direction correcting jacks that can connect and tilt the cutter head and the front end body with respect to the rear body, and when the pressure oil in the cylinder exceeds a predetermined pressure, The prior art in that it is constituted by a leading conductor provided with a relief means for relieving the pressurized oil, and a main pushing jack for propelling a succeeding pipe connected to the trunk on the rear end side. This is the same as the conventional pipe propulsion machine described in the section. Further, the tube propulsion device according to the second embodiment of the present invention includes an interlock for stopping the propulsion of the subsequent tube by the main push jack when the rotation of the cutter head is stopped, similarly to the conventional tube propulsion device. ing.

First, a characteristic technical content of a tube propulsion device according to a first embodiment of the present invention will be described with reference to FIGS.
The pipe propulsion device of the first embodiment is an example in which the technical means employed in the first and second inventions of the present application are combined and embodied. In FIG. 1, reference numeral 1 denotes a direction correcting stroke meter for detecting a numerical value for calculating a stroke of the direction correcting jack, and is constituted by a means for changing an electric resistance value by expanding and contracting. The direction correcting stroke meter 1 can be attached between the piston rod and the cylinder of the direction correcting jack so as to directly determine the stroke of the direction correcting jack. In order to arrange in the space so that it does not get in the way, it is indirectly connected to the torso at the front end and the torso at the back to determine the angular relationship between these torso. To be able to ask. In the present embodiment, the three-dimensional angular relationship between the front end trunk and the rear trunk is specified if at least the three points of the tilting front end trunk are determined. About three stroke meters 1 are provided at equal intervals in the inner circumferential direction of the leading conductor, and each of them is arranged between three direction correcting jacks.

Reference numeral 3 denotes a controller for controlling the direction correcting jack so as to stop the propulsion of the succeeding pipe by the main push jack if necessary. The operation unit 4 has a comparison operation function. And a control unit 5 that outputs a command signal to a solenoid 6 described later based on the result of the comparison and controls on / off of these. Reference numeral 6 denotes a solenoid of an electromagnetic opening / closing valve for the main push jack, which supplies pressure oil to the main push jack or stops the supply of the pressure oil to control the driving thereof. An electric signal relating to each detection result of the three direction correction stroke meters 1 is input to the calculation unit 4 of the controller 3. The control by the controller 3 is a signal indicating that the direction-correcting jack is not operated, that is, a signal indicating that the direction-correcting jack is not operated by the operator, so as not to cause confusion in the direction correcting operation of the operator. Is performed only when is input to the arithmetic unit 4. As described above, the pipe propulsion device of the present embodiment is a combination of the technical means of the first and second inventions of the present application. Explanation will be given for each related matter.

First, matters related to the first invention of this application will be described. When each of the detection results of the three direction correction stroke meters 1 is input, the calculation unit 4 calculates a value related to the tilt angle of the trunk at the front end side of the leading conductor based on the detection results, and based on the calculation results. Values for each stroke of the three direction correcting jacks are calculated. The arithmetic unit 4 stores in advance a contraction limit set value set to determine the contraction limit of the direction correcting jack. The contraction limit set value can be set to an actual contraction limit value of the direction correcting jack, that is, a value at which the stroke of the direction correcting jack becomes 0. However, in this embodiment, the measurement error of the direction correcting stroke meter 1 is measured. In consideration of the above, the stroke of the direction correcting jack is set to a value that becomes, for example, 2 mm, so as to be slightly larger than the actual contraction limit value. The calculation unit 4 compares the calculated value for each stroke of the direction correcting jack with the contraction limit set value. As a result, when it is determined that at least one of the direction correcting jacks has contracted until the contraction limit set value is reached, the solenoid 6 of the solenoid valve for the main push jack is energized through the control unit 5. The supply path of the pressure oil to the main push jack is closed by an electromagnetic on-off valve, and the propulsion of the subsequent pipe by the main push jack is stopped.

Next, matters related to the second invention of this application will be described. When an excessive external force acts on the direction correcting jack to operate the relief valve and release the pressurized oil in the cylinder, the direction correcting jack contracts even when it is not operated by the operator. Further, as described above, the direction correcting jack may extend due to a reaction force of the rotational force of the cutter head or an external force in the lateral direction. For this reason, the calculation unit 4 determines whether or not each direction correcting jack is contracted or extended when not operated by the operator, and thereafter, whether an excessive external force is acting on the direction correcting jack. It is determined whether or not it is. For this purpose, it is necessary to first determine whether or not any of the three direction correcting jacks is being operated. As described above, this determination is made in the present embodiment. This is performed before the control by the controller 3 is performed, and is performed by the calculation unit 4 based on whether or not the detected value of the direction correcting stroke meter 1 has changed with time. When it is determined that all the three direction correcting jacks are not operated, it is determined whether the value related to the stroke of the direction correcting jack calculated by the calculating unit 4 is fluctuating. You. As a result, when it is determined that the value related to the stroke of at least one of the direction correcting jacks has fluctuated, the solenoid 6 is urged through the control unit 5 to cause the main push jack to close the subsequent pipe. Try to stop propulsion.

The operation of the above-described first preferred embodiment of the present invention will be described with reference to FIG.
First, it is determined whether or not the direction correcting jack is in the non-operation state. As a result, when it is determined that all three direction correcting jacks are in the no-operation state, the arithmetic unit 4 determines whether the direction correcting jack is in the contracted state, that is, the direction correcting jack is in the contraction limit setting. It is determined whether or not contraction occurs until the value is reached. As a result, when it is determined that at least one of the three direction correcting jacks is in the contracted state, the control unit 5 of the controller 3
To generate an electric signal to energize the solenoid 6 and stop the propulsion of the subsequent pipe by the main push jack. When it is determined that none of the three direction correcting jacks is in the contracted state, the arithmetic unit 4 determines whether or not the direction correcting jack has moved, that is, one operation of reducing or expanding the direction correcting jack. It is determined whether it has been done. As a result, when it is determined that at least one of the three direction correcting jacks has contracted or expanded, the control unit 5 emits an electric signal to energize the solenoid 6, and the original pushing jack causes the subsequent pipe to be opened. Stop propulsion. Propulsion of the succeeding pipe by the main push jack is continued except in the above cases. When the propulsion of the succeeding pipe by the main pushing jack is stopped in the above control process by the controller 3, the propulsion speed of the subsequent pipe is inevitably higher than the cutting speed of the cutter. By increasing the cutting speed of the cutter to increase the cutting speed of the cutter, or decreasing the propulsion speed of the succeeding pipe by the main push jack, the pipe propulsion method can be continued thereafter.

As described above, the pipe propulsion device of this embodiment has three
When at least one of the direction-correcting jacks shrinks to the contraction limit set value, the pushing of the subsequent pipe by the main push jack is stopped, so that the direction-correcting jack can be cylinder-operated when the direction-correcting jack is not operated. The propulsion of the succeeding pipe while mechanically holding it between the piston and the piston is prohibited, and the following pipe can only be propelled while the direction-correcting jack is held in hydraulic pressure. Does not act on the direction correcting jack to damage the cylinder or piston rod. In addition, in the case where the following pipe is propelled while the direction correcting jack is held in the hydraulic pressure, the direction correcting jack may release the pressurized oil by the relief valve when an excessive external force is applied, even in a non-operation state. In the present embodiment, when at least one of the plurality of direction correcting jacks is reduced or extended in a state where it is not operated, the propulsion of the subsequent pipe by the original pushing jack is stopped. Therefore, at the early stage when the direction correcting jack does not hold the hydraulic pressure, the propulsion of the subsequent pipe by the main push jack is immediately stopped, which also causes the excessive direction correcting jack to act when the subsequent pipe is propelled. Damage due to excessive external force can be prevented.

On the other hand, in the case where the direction correcting jack stops holding the hydraulic pressure due to the operation of the relief valve, the pipe propulsion device is in a state where the trunk at the front end fluctuates and the propulsion direction is not determined. Continued propulsion of the tube may result in propulsion deviating from a predetermined path. However, in this embodiment, when the direction correcting jack stops holding the hydraulic pressure due to the operation of the relief valve, the propulsion of the subsequent pipe by the main pushing jack is immediately stopped. Can be prevented from being propelled out of the predetermined route as much as possible,
The construction accuracy of the pipe propulsion method can be improved as compared with a conventional pipe propulsion machine. As described above, since the pipe propulsion device of this embodiment is provided with two types of direction correction jack protection means for stopping the propulsion of the subsequent pipe by the main push jack, the direction correction jack is used when the subsequent pipe is propelled. In addition to being able to reliably prevent damage due to external forces acting on the pipe, it is also possible to improve the construction accuracy of the pipe propulsion method. It can also be provided. When the pipe propeller is propelled by operating the direction correcting jack, there are two methods, one is to operate the direction correcting jack based on the stretched state and the other is to operate the direction correcting jack based on the contracted state. The pipe propulsion device according to the embodiment exhibits such an excellent effect when propelled using the former method.

The characteristic technical contents of the tube propulsion device according to the second embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same parts as those in FIG.
Not detailed. The tube propulsion device of this embodiment has a problem with the conventional interlock that has a conventional interlock that stops the propulsion of the subsequent tube by the main push jack when the rotation of the cutter head stops. This can be used effectively while solving the problem. In FIG. 3, reference numeral 2 denotes a cutter oil pressure detector that detects the pressure of the hydraulic oil of a hydraulic motor that rotationally drives the cutter head, and returns by detecting the pressure of the hydraulic oil of the hydraulic motor that drives the cutter head. , A value corresponding to the driving torque of the cutter head is detected. Reference numeral 3a denotes a controller which controls the rotation of the cutter head as necessary to stop the propulsion of the succeeding pipe by the main push jack through an interlock mechanism in order to protect the direction correcting jack. An operation unit 4a having a function and a control unit 5a that outputs a command signal to a solenoid 7 described later based on a comparison result of the operation unit 4a and controls on / off of the command signal are provided. Reference numeral 7 denotes a solenoid of a solenoid on-off valve for a hydraulic motor that controls the drive by supplying or stopping the supply of hydraulic oil to the hydraulic motor for driving the cutter head. An electric signal relating to each detection result of the three direction correction stroke meters 1 and an electric signal relating to the detection result of the cutter oil pressure detector 2 are also input to the calculation unit 4a of the controller 3a. Controller 3 described above
The control according to a is performed only when the direction correcting jack is in an inoperative state, as in the case of the tube propulsion device of the first embodiment shown in FIGS.

As described above, recently, the performance of the cutter with respect to the cutter torque and the cutting performance have been improved. Therefore, even if an excessive external force acting on the leading conductor acts to damage the direction-correcting jack, the conventional pipe propulsion device cannot be used. However, the cutter head continues to rotate without stopping, and the interlock does not function effectively. For this reason, in the present embodiment, when the driving torque of the cutter head reaches a predetermined limit value, even if the cutter head does not stop by the action of an external force, the cutter head is stopped artificially by a command of the controller 3a, This allows
The propulsion of the subsequent pipe by the main push jack is stopped through the conventional interlock. By the way, when the amount of tilting of the front end side trunk portion, that is, the tilting angle increases, the reaction force based on the propulsive force of the main push jack increases and acts on the direction correcting jack in accordance with the increase. Also,
When the amount of tilt of the front end body is increased, the connecting mechanism of the spherical bearing in the direction correcting jack is also easily damaged. For this reason, the limit value of the driving torque of the cutter head for stopping the cutter head is not set uniformly regardless of the tilt amount of the body,
It is desirable to set so as to decrease as the tilt amount increases.

Based on such an idea, the arithmetic unit 4a includes:
The threshold value of the cutter torque, which is the limit value of the value related to the drive torque of the cutter head for stopping the cutter head, is set and stored in advance. The threshold value of the cutter torque is smaller than a value related to the driving torque of the cutter head when the cutter head is stopped by the action of an external force, and decreases in accordance with an increase in the tilt amount of the front end body. So that the cutter head is stopped before the direction correcting jack is damaged, and the propulsion of the succeeding pipe by the main pushing jack is stopped, so that the direction correcting jack is not damaged regardless of its tilting amount. I have to. As described above, since the threshold value of the cutter torque is set to a different value for each tilt amount of the trunk on the front end side, it is stored as a table. In this embodiment, the cutter head is rotationally driven by a hydraulic motor, and the drive torque of the hydraulic motor is reflected in the pressure of the hydraulic oil. Although a value is adopted, the threshold value of the cutter torque may be a numerical value of another unit as long as the numerical value reflects the driving torque of the cutter head.

As described above, since the signal relating to each detection result of the direction correcting stroke meter 1 is input to the calculation unit 4a, it is possible to calculate a value relating to the tilt amount of the trunk at the front end side of the leading conductor. Therefore, the threshold value of the cutter torque corresponding to the value related to the tilt amount can be read from the table based on the calculation result of the value related to the tilt amount. In addition, the arithmetic unit 4a receives a signal related to the detection result of the cutter oil pressure detector 2 when the cutter head is driven to rotate, and gives a value related to the torque of the cutter head at each time when the cutter head is driven.
The value related to the torque of the cutter head is compared with the threshold value of the cutter torque read from the table.
As a result, when it is determined that the value related to the torque of the cutter head has reached the threshold value of the cutter torque during the rotational driving of the cutter head, the solenoid 7 of the electromagnetic on-off valve for the hydraulic motor is attached through the control unit 5a. To stop the rotary drive of the cutter head, thereby stopping the propulsion of the subsequent pipe by the main push jack through the interlock.

Since the pipe propulsion device according to the second embodiment of the present invention employs such technical means, the computing unit 4a of the controller 3a first determines whether or not the direction correcting jack is in a non-operation state. Is determined. As a result, when it is determined that all three direction correcting jacks are in the non-operation state, the arithmetic unit 4a determines that the value related to the torque of the cutter head reaches the threshold value of the cutter torque when the cutter head is driven to rotate. Is constantly determined. As a result, when it is determined that the value related to the torque of the cutter head has reached the threshold value of the cutter torque, the controller 5a of the controller 3a controls the controller 3a even if the cutter head is not stopped by an external force. Emit an electric signal to energize the solenoid 7 to artificially stop the rotary drive of the cutter head,
As a result, the interlock is operated to stop the propulsion of the succeeding pipe by the main push jack. Therefore, according to this embodiment, even when the conventional interlock is provided in a pipe propulsion device having excellent cutter torque performance and cutting performance and the cutter head is difficult to stop due to external force, the direction correcting jack is damaged. The cutting head can be stopped before stopping the propulsion of the following pipe. The rotation of the cutter head and the propulsion of the subsequent pipe by the main push jack are continued except in such a case. On the other hand, the direction correction jack is
When the amount of tilt of the front end body increases, the reaction force based on the propulsion force of the main push jack acts in accordance with the increase, but in the tube propulsion device of this embodiment, the cutter torque is reduced. The threshold value is set not to be set uniformly regardless of the tilt amount of the front end body, but to decrease as the tilt amount increases. Even when used in a state where the jack has been reduced to the limit, the direction correcting jack can be prevented from being damaged irrespective of the amount of tilt. The pipe propulsion device of the present embodiment exhibits such an excellent effect particularly when propulsion is performed using a method of operating a direction correcting jack based on a contracted state. In addition, the pipe propulsion device of this embodiment is provided with the protection means for the second direction correcting jack in the first embodiment,
Prevents the direction-correcting jack from being damaged by external forces acting when the following pipe is propelled, even when propulsion is performed by selectively using two methods of operating the direction-correcting jack based on the stretched state as well as the contracted state. In addition, the construction accuracy of the pipe propulsion method can be improved.

[0024]

As is apparent from the above description, the first invention, the second invention and the third invention of the present application each have 1) "means for solving the problem". ,
Since the technical means shown in 2) and 3) are adopted, a pipe propulsion machine which can prevent the direction correcting jack from being damaged by an external force acting when the subsequent pipe is propelled can be obtained by any of the inventions. In that case, according to the second invention of this application, since the pipe propulsion machine can be prevented from being propelled out of the predetermined route as much as possible, the construction accuracy of the pipe propulsion method can be improved. it can. According to the third invention of this application, even when the direction correcting jack is used in a state where the direction correcting jack is contracted to the contraction limit, the direction correcting jack can be prevented from being damaged regardless of the tilt amount. When the first invention of this application is embodied, in particular, if the technical means described in claim 4 is employed, the first effect of this application will be obtained, The effect that the construction accuracy of the propulsion method can be improved can also be achieved. In the case of embodying the third invention of this application, in particular, if the technical means described in claim 5 is adopted, the third invention of this application described above can be obtained.
In addition to the effects of the third invention, it is possible to achieve an effect that the construction accuracy of the pipe propulsion method can be improved as compared with the conventional pipe propulsion machine.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a direction correcting jack protection device in a pipe propulsion device according to a first embodiment of the present invention.

FIG. 2 is a flowchart for the direction correcting jack protection device of FIG. 1;

FIG. 3 is a system configuration diagram of a direction correcting jack protection device in a pipe propulsion device according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Direction correction stroke meter 2 Cutter oil pressure detector 3 Controller 3a Controller 4 Operation unit 4a Operation unit 5 Control unit 5a Control unit 6 Solenoid of solenoid on-off valve for main push jack 7 Solenoid of solenoid on-off valve for hydraulic motor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Moro 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Hideki Moriya 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Inside the Tsuchiura Plant (56) References JP-A-4-16696 (JP, A) JP-A-8-135368 (JP, A) JP-A-5-272294 (JP, A) JP-A-3-111169 (JP, A) U) Japanese Utility Model Hei 2-62998 (JP, U) Japanese Utility Model Application Sho 57-199751 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/06 311

Claims (5)

(57) [Claims] 1. A plurality of body parts which are tiltably connected to each other, a cutter head for ground excavation provided on a body part on a front end side, and a body part on a front end side are connected to a body part on the rear side thereof. A plurality of direction correcting jacks that can be tilted, a leading conductor provided with a relief means for relieving the pressure oil in the cylinder when the pressure oil in the cylinder exceeds a predetermined pressure, and a rear end side; And a propulsion jack for propelling a succeeding pipe connected to the body of the pipe propulsion device, a contraction limit set value for determining a contraction limit of the direction correction jack is set, and a plurality of direction correction jacks are set. Wherein the propulsion jack stops the propulsion of the succeeding pipe when it is determined that at least one of the direction correcting jacks has contracted until the contraction limit set value is reached. 2. A plurality of body parts which are tiltably connected to each other, a cutter head for ground excavation provided on a body part on the front end side and a body part on the front end side are connected to a body part on the rear side thereof. A plurality of direction correcting jacks that can be tilted, a leading conductor provided with a relief means for relieving the pressure oil in the cylinder when the pressure oil in the cylinder exceeds a predetermined pressure, and a rear end side; And a propulsion jack for propelling a succeeding pipe connected to the body of the pipe propulsion machine, wherein at least one of the plurality of direction correction jacks is reduced or expanded in a state where it is not operated. A pipe propulsion machine characterized in that the propulsion jack stops the propulsion of the succeeding pipe when it is determined that: 3. A plurality of body parts which are tiltably connected to each other, a cutter head for ground excavation provided on a body part on the front end side, and a body part on the front end side are connected to a body part behind the body part. A plurality of direction correcting jacks that can be tilted, a leading conductor provided with a relief means for relieving the pressure oil in the cylinder when the pressure oil in the cylinder exceeds a predetermined pressure, and a rear end side; A propulsion jack for propelling the subsequent pipe connected to the body of the pipe propulsion apparatus, and an interlock for stopping the propulsion of the subsequent pipe by the propulsion jack when the rotation of the cutter head is stopped. The threshold value of the cutter torque, which is the limit value of the drive torque of the cutter head that stops the rotation, is smaller than the value of the drive torque of the cutter head when the cutter head is stopped by an external force. And, it is set so that it decreases with an increase in the amount of tilt of the front end body, and when the cutter head is rotationally driven, the value relating to the torque of the cutter head reaches the threshold value of the cutter torque. A pipe propulsion machine characterized in that when it is determined, the rotation drive of the cutter head is stopped to stop the propulsion jack from propelling the succeeding pipe through an interlock. 4. The method according to claim 1, wherein when at least one of the plurality of direction correcting jacks is determined to have contracted or expanded without being operated, the propulsion jack stops propulsion of the subsequent pipe. The tube propulsion device according to claim 1, wherein 5. A propulsion jack for stopping the propulsion of a subsequent pipe when it is determined that at least one of the plurality of directional correction jacks has contracted or expanded in a state where it has not been operated. The tube propulsion device according to claim 3, wherein