JP2008127825A - Method and device for detecting load on front of cutter of excavator, and excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for detecting a load on the front of a cutter, which enable the load on the front of the cutter to be inexpensively and accurately detected in a space-saving manner, and an excavator. <P>SOLUTION: This load detecting device comprises a first displacement detecting means (20) for detecting the first thrust-direction displacement of a center shaft (4) or a shaft supporting member (6) with respect to a frame (1), and a second displacement detecting means (22) for detecting the second thrust-direction displacement of the center shaft (4) with respect to the shaft supporting member (6). Additionally, the load detecting device is also equipped with a control means (32) for controlling the propulsion speed of a propelling means (10) depending on the first and second displacements. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an excavator cutter front load detection method and apparatus and an excavator, and more particularly to a technique for detecting a cutter front load of an excavator at low cost and in a small space.

The excavator for excavating tunnels and other tunnels in the ground has a center shaft support system in which the cutter head is rotatably supported by the center shaft, and an intermediate beam having a rotating ring in the partition wall and rotatably supporting the cutter head There are various methods such as a support method and a peripheral beam support method in which the cutter head is rotatably supported by the peripheral beam.
For example, in the case of an excavator using a center shaft support system, the center shaft of the cutter head passes through the center of a partition wall provided at the front end of the outer shell frame, for example, and passes through a cutter bearing consisting of a thrust bearing and a radial bearing. The cutter head gear fixed to the center shaft is driven by a drive motor via a pinion so as to be rotatable.

  By the way, in the case of a shield machine, for example, in the case of a shield machine, the cutter head is configured to move forward by extending a jack provided at the rear while cutting the debris with the cutter head. Since it is strongly pressed by the earth and stone, it receives a cutter front load as a reaction force. When the cutter head receives the cutter front load in this way, in the center shaft support system, the cutter front load is transmitted to the cutter bearing, the shaft support member, and then the partition wall via the center shaft. Therefore, a very large force acts on the cutter bearing and the shaft support member and thus the partition wall. Depending on the situation, the shaft support member and the partition wall may be greatly bent backward, or the thrust bearing function of the cutter bearing may be impaired. There is a risk of machine failure.

Therefore, various methods for detecting the front load of the cutter have been considered in order to prevent such a failure of the excavator.For example, a strain gauge is installed on the shaft support member, etc. There is a known technique for detecting a front load of a cutter by comparing a stress value calculated based on a stress value obtained by setting a load condition in advance and obtained by structural analysis (see Patent Document 1).
JP 2000-170477 A

However, in the case of the method disclosed in Patent Document 1, it is necessary to set a load condition in advance and perform a structural analysis, and there is a problem that it takes time to detect the cutter front load.
In addition, in this method, it is necessary to install equipment for calculating the strain gauge detection results in the excavator, which is not only costly, but also requires equipment installation space, especially the center shaft support method is often used. However, the small digging machine with a small diameter has a drawback that the installation space is small and it is difficult to adopt the method.

Furthermore, it is not easy to properly arrange the strain gauges, and there is a situation in which a specialist must be relied upon.
The present invention has been made to solve such problems, and its object is to detect the cutter front load of the excavator that can accurately detect the load on the front of the cutter of the excavator at low cost and space-saving. It is to provide a method and apparatus and an excavator.

  In order to achieve the above object, the cutter front load detecting method of the excavator according to claim 1 is characterized in that the cutter head for cutting the debris by rotation is rotatably supported by the frame via the support member by the turning member, and the propulsion means A method for detecting a load on a cutter front surface of an excavator that advances the cutter head together with the frame, the support member, and the turning member while cutting the debris by propelling the frame by: A first displacement in the thrust direction of the support member is detected, a second displacement in the thrust direction of the swiveling member with respect to the support member is detected, and at least one of these first and second displacements is When the value is larger than the initial value, the cutter head is considered to have received a cutter front load corresponding to the displacement.

  The cutter front load detection device for an excavator according to claim 2 is configured such that a cutter head for cutting debris by rotation is rotatably supported on a frame by a turning member via a support member, and propelling means propels the frame. A cutter front load detection device for an excavator that advances the cutter head together with the frame, the support member, and the turning member while cutting the earth and stones, and is a first in the thrust direction of the turning member or the support member with respect to the frame. First displacement detection means for detecting the displacement of the second rotation detection means, and second displacement detection means for detecting a second displacement in the thrust direction of the swiveling member with respect to the support member, and at least one of the first and second displacements. When either one is larger than each initial value, it is considered that the cutter head has received a cutter front load corresponding to the displacement. And features.

According to a third aspect of the present invention, there is provided the cutter front load detecting device according to the second aspect, wherein the first displacement detecting means and the second displacement detecting means are each composed of a displacement sensor or a distance measuring sensor.
The excavator according to claim 4 is configured such that a cutter head that cuts debris by rotation is rotatably supported by a frame via a support member by a turning member, and the frame, the support member, and A first excavator that advances the cutter head together with the swivel member while cutting the debris, and detects a first displacement in a thrust direction of the swivel member or the support member with respect to the frame; A second displacement detecting means for detecting a second displacement in the thrust direction of the swiveling member with respect to the support member; and when at least one of the first and second displacements is larger than each initial value, the displacement is detected. Control means for controlling the propulsion speed of the propulsion means.

  In the excavator according to claim 5, in claim 4, when only the first displacement larger than the initial value is detected by the first displacement detection means, the control means according to only the first displacement. The propulsion speed of the propulsion means is limited, and when the second displacement detection means detects a second displacement larger than the initial value, the propulsion speed of the propulsion means is more largely limited according to the second displacement. It is characterized by.

  The excavator according to claim 6 is characterized in that, in claim 5, the control means stops the propulsion by the propulsion means when the second displacement detection means detects a second displacement of a predetermined value or more. And

  According to the cutter front load detection method for an excavator according to claim 1, the first displacement and the second displacement are detected, and when at least one of the first displacement and the second displacement is larger than each initial value, the cutter is detected. Since it is considered that the head has received the cutter front load corresponding to the displacement, the front load on the cutter can be accurately detected with low cost and space saving based on the two displacements of the first displacement and the second displacement. it can.

Thus, even with a small excavator, it is possible to accurately detect the cutter front load with a simple configuration.
According to the cutter front load detecting device of the excavator according to claim 2, the first displacement and the second displacement are detected by the first displacement detecting means and the second displacement detecting means, and the first and second displacements are detected. When at least one of them is larger than each initial value, it is considered that the cutter head has received a front load of the cutter according to the displacement. Therefore, the first displacement and the second displacement of the first displacement detection means and the second displacement detection means are considered. Based on the two displacements, the front load of the cutter can be accurately detected with low cost and space saving.

According to the cutter front load detecting device for an excavator according to claim 3, it is easy to use the displacement sensor or the distance measuring sensor for the first displacement detecting means and the second displacement detecting means, and the cutter front load is accurately and easily reduced. Can be detected.
According to the excavator of claim 4, the first displacement detection means and the second displacement detection means detect the first displacement and the second displacement, and at least one of the first displacement and the second displacement is each When it is larger than the initial value, the propulsion speed of the propulsion means is controlled in accordance with the displacement, so that it is based on the two displacements of the first displacement and the second displacement by the first displacement detection means and the second displacement detection means. The propulsion speed of the propulsion means can be appropriately limited while accurately detecting the front load of the cutter with low cost and space saving, and the excavator can be sufficiently protected.

  According to the excavator of claim 5, when only the first displacement larger than the initial value is detected, the propulsion speed of the propulsion means is limited according to only the first displacement, and the second displacement larger than the initial value is detected. When the displacement is detected, the propulsion speed of the propulsion unit is more greatly limited in accordance with the second displacement, so the first displacement and the second displacement by the first displacement detection unit and the second displacement detection unit. The propulsion speed of the propulsion means can be appropriately limited while accurately detecting the front load of the cutter based on the two displacements, and the excavator can be sufficiently protected.

  According to the excavator of claim 6, since the propulsion by the propulsion means is stopped when the second displacement of a predetermined value or more is detected, the excavator can be reliably protected without being damaged.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
First, the first embodiment will be described.
FIG. 1 is a longitudinal sectional view of an excavator according to a first embodiment to which the cutter front load detection method and apparatus of the present invention is applied (the hatched lines indicating member cross sections are omitted, and the same applies hereinafter).
In the first embodiment, a center shaft support type shield machine is employed as the machine.

  As shown in the figure, in the shield machine according to the first embodiment of the present invention, a partition wall 2 is integrally provided in a radial direction inside a front end of a cylindrical shield frame 1, and a central portion of the partition wall 2 is provided. A center shaft (swivel member) 4 joined to the cutter head 3 is rotatably passed therethrough. The rear end portion of the center shaft 4 is rotatably supported by a shaft support member (support member) 6 integrally joined to the partition wall 2 via a cutter bearing 5 including a thrust bearing 5a and a radial bearing 5b. Yes.

  A cutter headgear 7 is fitted on the center shaft 4 between the partition wall 2 and the shaft support member 6, while the shaft support member 6 has a pinion 9 that meshes with the cutter headgear 7. 8 is fixed. That is, the center shaft 4 is driven by the rotational drive motor 8 via the pinion 9 and the cutter head gear 7 and can rotate the cutter head 3 with high torque. Thereby, the shield machine can cut the earth and stones ahead by a plurality of cutter bits (not shown) arranged on the front surface of the cutter head 3 while rotating the cutter head 3. In FIG. 1, the cutter head 3, the center shaft 4, the cutter head gear 7, and the like are indicated by hatching, but the hatched portion is a portion rotated by the rotation drive motor 8.

  Further, the shield machine is provided with a shield jack (propulsion means) 10 (simply shown as a block) made of a hydraulic cylinder located at the rear end of the shield frame 1. Thereby, the shield machine can advance the shield machine by receiving the reaction force of the segment (not shown) installed behind by extending the shield jack 10 while cutting the earth and stone.

  An annular seal member 11 is provided at the rear end of the boss portion 6a of the shaft support member 6 in order to prevent the lubricant filled between the cutter bearing 5, that is, the center shaft 4 and the boss portion 6a, from scattering to the outside. The inner peripheral surface is brought into contact with the outer peripheral surface of the center shaft 4 and fixed by a plurality of bolts 12. Specifically, an annular protrusion 4a is formed on the outer peripheral surface of the center shaft 4 over the entire periphery, and the seal member 11 is a boss so as to abut at least the surface of the annular protrusion 4a on the front end side of the center shaft 4. It is fixed to the rear end of the part 6a.

  Then, two first displacement sensors (first displacement detection means) 20 and two second displacement sensors (second displacement detection means) 22 are arranged so as to detect displacement in the thrust direction of the outer surface 11a of the seal member 11. The first displacement sensor 20 is supported at the tip of the arm member 24, and the second displacement sensor 22 is supported at the tip of the arm member 26. Note that the arm members 24 and 26 are made of hollow square members having sufficient rigidity, for example.

  As shown in the enlarged view of the fixed portion of the second displacement sensor 22 in FIG. 2, the second displacement sensor 22 is configured such that the sensor tip 22 a is in contact with the outer surface 11 a of the seal member 11 by the metal fitting 23. It is fixed at the tip. Although not shown, the first displacement sensor 20 is also fixed to the distal end of the arm member 24 so that the sensor distal end portion 20a abuts on the outer surface 11a of the seal member 11 as in the second displacement sensor 22. ing.

  Specifically, the rear end of the arm member 24 supporting the first displacement sensor 20 is fixed to a part 1a of the shield frame 1, while the rear end of the arm member 26 supporting the second displacement sensor 22 is fixed. The shaft support member 6 is fixed. Thus, the first displacement sensor 20 can detect the relative displacement in the thrust direction of the center shaft 4 or the shaft support member 6 with respect to the shield frame 1 via the seal member 11, and the second displacement sensor 22 The relative displacement in the thrust direction of the center shaft 4 with respect to the support member 6 can be detected via the seal member 11.

  The operation panel 30 is a device for performing various operations and controls of the shield machine. In the shield machine according to the present invention, a cutter front load detection unit 31 and a shield jack control unit (control means) 32 are provided in the operation panel 30. And. The first displacement sensor 20 and the second displacement sensor 22 are electrically connected to the input side of the cutter front load detection unit 31, and the cutter front load detection unit 31 is internally connected to the shield jack control unit 32 for shield jack control. A hydraulic control unit (not shown) of the shield jack 10 is electrically connected to the output side of the unit 32.

Hereinafter, while explaining the operation of the center shaft support type shield machine configured as described above according to the present invention, the operation of the cutter front load detection method and the cutter front load detection device according to the present invention will also be described. .
As described above, the shield machine can advance the shield machine by rotating the cutter head 3 and extending the shield jack 10 while cutting the debris with the cutter bit.

However, in places where the soil to be excavated is hard, the cutter bit may not be able to sufficiently cut the debris even if the cutter head 3 is rotated. In such a case, even if the shield jack 10 is extended, the shield machine is not used. The cutter head 3 cannot be moved forward and receives a large load on the front surface of the cutter as a reaction force.
When the cutter head 3 receives a large load on the front surface of the cutter in this way, the load acts to push the center shaft 4 rearward in the thrust direction and mainly deflect the shaft support member 6 and thus the partition wall 2 via the thrust bearing 5a. To do. When the shaft support member 6 or the partition wall 2 is bent, the shaft support member 6 is displaced relative to the shield frame 1 in the thrust direction, and the sensor tip 20a is compressed via the seal member 11, and the shield. A relative displacement of the center shaft 4 or the shaft support member 6 with respect to the frame 1 is detected by the first displacement sensor 20.

  Further, when the cutter front load is extremely large, the load exceeds the bearing capacity of the thrust bearing 5a and tries to press the center shaft 4 in the thrust direction. In this case, the load is applied to the shaft support member 6. The center shaft 4 is relatively displaced in the thrust direction, and the seal member 11 is pushed by the annular protrusion 4a and bent to compress the sensor tip 22a, and the relative displacement of the center shaft 4 with respect to the shaft support member 6 is reduced. It is detected by the second displacement sensor 22.

When displacement is detected by the first displacement sensor 20 and the second displacement sensor 22 in this way, the displacement information is input to the cutter front surface load detection unit 31.
Referring to FIG. 3, a control routine of shield jack control executed by the cutter front load detection unit 31 and the shield jack control unit 32 is shown in a flowchart. Hereinafter, based on the flowchart, the shield jack control according to the first embodiment is performed. The contents of control will be described.

In step S10, the output D1 of the first displacement sensor 20 is read, and in step S12, the output D2 of the second displacement sensor 22 is read.
In step S14, whether the output D2 of the second displacement sensor 22 is larger than the initial value, that is, the center shaft 4 moves backward beyond the bearing capacity of the thrust bearing 5a, and the center shaft 4 is relative to the shaft support member 6. It is determined whether or not it has been displaced.

  Here, the initial value of the output D2 is, for example, a value when the second displacement sensor 22 is initially installed. Further, since the output D2 is approximately proportional to the cutter front load F2 in the range where the output D2 is equal to or greater than the initial value, the value of the output D2 and the cutter front load F2 are related in advance through experiments or the like. Yes. Normally, the determination result in step S14 is false (No), the output D2 of the second displacement sensor 22 is not changed and the initial value is maintained (no output change). In this case, the process proceeds to step S16.

In step S16, whether the output D1 of the first displacement sensor 20 is larger than the initial value, that is, the shaft support member 6 and the partition wall 2 are bent by the front load of the cutter, and the center shaft 4 or the shaft support member 6 with respect to the shield frame 1. It is determined whether or not is relatively displaced.
Here, the initial value of the output D1 is, for example, a value when the first displacement sensor 20 is initially installed. Further, since the output D1 is substantially proportional to the cutter front load F1 in the range where the output D1 is equal to or larger than the initial value, the value of the output D1 and the cutter front load F1 are similar to the output D2 in the experiment or the like. Are related in advance. The cutter front load F2 is a force larger than the deflection of the shaft support member 6 and the partition wall 2, that is, a force large enough to retract the center shaft 4 beyond the bearing capacity of the thrust bearing 5a. When the output D2 and the output D2 are the same, the cutter front load F2 is larger than the cutter front load F1.

  If the determination result in step S16 is false (No) and an output D1 larger than the initial value is not detected (when there is no output change), the cutter front surface load F1 can be determined as the durable range of the structural member, and the routine is called Exit. On the other hand, when the determination result is true (Yes) and the output D1 of the first displacement sensor 20 is larger than the initial value, the cutter head 3 can be regarded as having received the cutter front load F1 corresponding to the output D1. The process proceeds to step S18.

  In step S18, the shield jack speed is controlled according to the output D1 of the first displacement sensor 20. Specifically, the shield jack speed is corrected to the deceleration side by, for example, gain G1, so that the shield jack speed decreases as the output D1 increases. That is, when only the output D1 larger than the initial value is detected, the shield jack speed is limited based only on the output D1. The gain G1 is appropriately set based on experiments and the like.

On the other hand, if the determination result of step S14 is true (Yes) and the output D2 of the second displacement sensor 22 is larger than the initial value, the cutter head 3 receives the cutter front load F2 corresponding to the output D2. The process proceeds to step S20.
In step S20, it is determined whether or not the output D2 of the second displacement sensor 22 is greater than or equal to a predetermined value. That is, it is determined whether or not the cutter front load F2 corresponding to the output D2 has reached an extremely large value that indicates the damage of the thrust bearing 5a. If the determination result is false (No) and the output D2 is less than the predetermined value, the process proceeds to step S22.

  In step S22, the shield jack speed is controlled in accordance with the output D2. In this case, since it can be determined that a large force is applied to the cutter head 3 at least exceeding the bearing capacity of the thrust bearing 5a as described above, specifically, the shield jack speed is increased according to the increase in the output D2. The shield jack speed is corrected to the deceleration side with a gain G2 larger than the gain G1 so as to be significantly reduced. That is, when an output D2 larger than the initial value and less than a predetermined value is detected, the shield jack speed is more greatly limited based on the output D2. Note that the gain G2 is appropriately set by experiment or the like as described above.

On the other hand, if the determination result in step S20 is true (Yes) and the output D2 of the second displacement sensor 22 is determined to be greater than or equal to a predetermined value, the cutter front load F2 is extremely high enough to indicate that the thrust bearing 5a is damaged. It can be determined that the maximum value has been reached. In this case, the process proceeds to step S24, and the operation of the shield jack 10 is stopped.
Thus, in the cutter front load detection method and apparatus and the excavator according to the present invention, the first displacement sensor 20 and the second displacement sensor 22 are used in the center shaft support type excavator, and the first displacement is detected. The sensor 20 detects the relative displacement (output D1) of the center shaft 4 or the shaft support member 6 with respect to the shield frame 1, and the second displacement sensor 22 detects the relative displacement (output D2) of the center shaft 4 with respect to the shaft support member 6. The shield jack 10 is controlled to be decelerated based on the detection information.

  Therefore, according to the cutter front load detection method and apparatus and the excavator, the center shaft support type excavator uses two displacement sensors, and performs complex computation based on the outputs from the two displacement sensors. By eliminating the need for processing, the operation panel 30 can be used effectively without the need for additional processing equipment, and the overall configuration is simple and low-cost and space-saving is achieved as a whole. Can be detected. Furthermore, based on the output from these two displacement sensors, the shield jack 10 can be appropriately decelerated or stopped, and the excavator can be sufficiently protected. In particular, when the output D2 of the second displacement sensor 22 is equal to or greater than a predetermined value and the cutter front load F2 is an extremely large value, the operation of the shield jack 10 is stopped. Can be protected.

As a result, the center shaft support method tends to be frequently used in small digging machines with a small diameter. Even in such a small digging machine, by applying the cutter front load detection method and apparatus according to the present invention. Although it has a simple configuration, it can accurately detect the load on the front surface of the cutter and protect the excavator reliably.
Referring to FIG. 4, a control routine for shield jack control according to a modification of the first embodiment is shown in a flowchart. Hereinafter, the control contents of the shield jack control according to the modification of the first embodiment are described based on the flowchart. explain.

In this modification, first, similarly to steps S10 and S12 of FIG. 3, the output D1 of the first displacement sensor 20 is read in step S30, and the output D2 of the second displacement sensor 22 is read in step S32.
In step S34, the output D1 is converted into a cutter front load F1. Specifically, the value of the output D1 and the cutter front surface load F1 are correlated in advance through an experiment or the like and mapped, and the cutter front surface load F1 is obtained from the map.

  In step S36, the output D2 is converted into a cutter front load F2. Specifically, similarly to the cutter front surface load F1, the value of the output D2 and the cutter front surface load F2 are previously associated with each other through experiments or the like and mapped, and the cutter front surface load F2 is obtained from the map. As described above, when the output D1 and the output D2 are the same value, the cutter front load F2 takes a larger value than the cutter front load F1.

  In step S38, based on the output D2 of the second displacement sensor 22, whether or not a cutter front load F2 larger than the initial load value corresponding to the initial value of the output D2 has been detected, that is, exceeds the bearing capacity of the thrust bearing 5a. It is determined whether or not the cutter front load F2 is generated such that the shaft 4 moves backward and the center shaft 4 is displaced relative to the shaft support member 6 to exceed the initial load value. If it is normal, the determination result is false (No), and the cutter front surface load F2 larger than the initial load value is not detected (no output change), and the process proceeds to step S40.

  In step S40, whether or not the cutter front load F1 larger than the initial load value is detected based on the output D1 of the first displacement sensor 20, that is, the shaft support member 6 and the partition wall 2 are bent by the cutter front load, and the shield frame 1 is deformed. Then, it is determined whether or not the cutter front surface load F1 is generated such that the center shaft 4 or the shaft support member 6 is relatively displaced and exceeds the initial load value. When the determination result is false (No) and the cutter front load F1 larger than the initial load value is not detected (when there is no output change), that is, the cutter front load F1 or the cutter front load F2 exceeds the initial load value. When neither the output D2 nor the output D1 is detected, the cutter front load can be determined as the durable range of the structural member, and the routine is exited. On the other hand, when the determination result is true (Yes) and the cutter front surface load F1 larger than the initial load value is detected based on the output D1 of the first displacement sensor 20, the process proceeds to step S42.

In step S42, similarly to the above, the shield jack speed is limited based only on the cutter front surface load F1.
On the other hand, if the determination result in step S38 is true (Yes) and a cutter front load F2 larger than the initial load value is detected based on the output D2 of the second displacement sensor 22, the process proceeds to step S44.

In step S44, it is determined whether or not the cutter front surface load F2 is equal to or greater than a predetermined load value corresponding to the predetermined value of the output D2. If the determination result is false (No) and the cutter front surface load F2 is less than the predetermined load value, the process proceeds to step S46.
In step S46, the shield jack speed is more greatly limited according to the cutter front load F2 as described above.

On the other hand, if the determination result in step S44 is true (Yes) and it is determined that the cutter front surface load F2 is equal to or greater than the predetermined load value, the process proceeds to step S48, and the operation of the shield jack 10 is stopped as described above.
Also in this modification example, two displacement sensors are used, and based on the outputs from these two displacement sensors, complicated operation processing is not required, so that operation equipment is not required separately. It is possible to accurately detect the load on the front surface of the cutter while effectively using 30 and realizing a low cost and space saving as a whole with a simple configuration. Further, the shield jack 10 can be appropriately decelerated or stopped based on the outputs from these two displacement sensors, and the excavator can be sufficiently protected.

Next, a second embodiment will be described.
FIG. 5 is a longitudinal sectional view of an excavator according to a second embodiment to which the cutter front load detection method and apparatus of the present invention is applied.
In the second embodiment, an intermediate beam support type shield machine is employed as the machine.

  As shown in the figure, in the shield machine according to the second embodiment of the present invention, the partition wall 102 is integrally provided in the radial direction inside the front end of the cylindrical shield frame 101, and a plurality of cutter heads 103 are attached to the cutter head 103. An annular swirl ring (swivel member) 107 joined through the beam 104 is disposed through the partition wall 102. The swivel ring 107 is rotatably supported by a swirl ring support member (support member) 106 joined to the partition wall 102 through a cutter support roller 105 including thrust rollers 105a and 105c and a radial roller 105b. Yes. Specifically, the cutter support roller 105 is provided at a plurality of locations on the annular swivel rail 106 a disposed on the swivel ring support member 106 along the shield frame 101 with a constant interval in the circumferential direction. As a result, the cutter head 103 can turn along the turning rail 106a.

  Gear teeth are formed on the inner peripheral surface of the swivel ring 107, and a plurality of rotation drive motors 108 fixed to the swirl ring support member 106 are connected via a pinion 109. That is, the turning ring 107 is driven by the rotation drive motor 108 via the pinion 109 and can rotate the cutter head 103 with high torque. As a result, the shield machine can cut the front soil with a plurality of cutter bits (not shown) arranged on the front surface of the cutter head 103 while rotating the cutter head 103.

  Also in the shield machine, a shield jack (propulsion means) 10 (simply shown as a block) made of a hydraulic cylinder is provided at the rear end of the shield frame 101. Thereby, the shield machine can advance the shield machine by receiving the reaction force of the segment (not shown) installed behind by extending the shield jack 10 while cutting the earth and stone.

  Then, the first distance measuring sensor (first displacement detecting means) 120 is constant in the circumferential direction corresponding to, for example, the cutter support roller 105 so as to detect the displacement in the thrust direction in the vicinity of the swing rail 106 a of the swing ring support member 106. A plurality of second distance measuring sensors (second displacement detecting means) 122 correspond to the first distance measuring sensor 120 so as to detect the displacement of the turning ring 107 in the thrust direction. A plurality of them are provided.

  Specifically, the first distance sensor 120 is supported by the tip of the arm member 124 extending from the shield frame 101 so as to be able to measure the distance to the turning ring support member 106, and the second distance sensor 122. Is arranged so that the distance to the swivel ring 107 can be measured by being directly supported by the swivel ring support member 106. The arm member 124 is made of, for example, a hollow square member having sufficient rigidity.

Accordingly, the first distance sensor 120 can detect the relative displacement in the thrust direction of the turning ring support member 106 and the turning ring 107 with respect to the shield frame 101, and the second distance measurement sensor 122 can detect the turning ring support member. The relative displacement in the thrust direction of the swivel ring 107 with respect to 106 can be detected.
Also in the shield machine, as in the case of the first embodiment, an operation panel 30 including a cutter front load detection unit 31 and a shield jack control unit (control means) 32 is provided. The first distance sensor 120 and the second distance sensor 122 are electrically connected to the input side of the front load detection unit 31, and the hydraulic control unit (for the shield jack 10) is connected to the output side of the shield jack control unit 32. (Not shown) are electrically connected.

The operation of the cutter front load detection device and the cutter front load detection device according to the present invention will be described together with the operation according to the present invention of the shield machine with the intermediate beam support system configured as described above. Note that items common to the first embodiment and its modifications will be described in a simplified manner.
In the intermediate beam support type shield machine, when the cutter head 103 receives a large load on the front surface of the cutter, the load presses the swivel ring 107 rearward in the thrust direction via the plurality of beams 104, and mainly pushes the thrust roller 105c. Accordingly, the swing rail 106a, that is, the swing ring support member 106, and thus the partition wall 102 is bent. When the swivel ring support member 106 and the partition wall 102 are bent, the swivel ring support member 106 is displaced relative to the shield frame 101 in the thrust direction, that is, between the swivel ring support member 106 and the first distance measuring sensor 120. And the relative displacement of the swivel ring support member 106 with respect to the shield frame 101 is detected by the first distance measuring sensor 120.

  Furthermore, when the cutter front load is extremely large, the load exceeds the load resistance of the thrust roller 105c and tries to press the swivel ring 107 in the thrust direction. Thus, the turning ring 107 is relatively displaced in the thrust direction, that is, the distance between the turning ring 107 and the second distance measuring sensor 122 is shortened, and the relative displacement of the turning ring 107 with respect to the turning ring support member 106 is the second measurement. It is detected by the distance sensor 122.

  When displacement is detected by the first distance sensor 120 and the second distance sensor 122 in this way, the displacement information is input to the cutter front load detector 31 and the cutter front load detector 31 and the shield jack controller 32. The shield jack control is performed in the same manner as described above based on the control routine of FIG. The shield jack control is the same as described above and will not be described here. In the second embodiment, the first displacement sensor 20 in steps S10 and S30 is replaced with the first distance measuring sensor 120, and steps S12 and S32 are performed. The second displacement sensor 22 is replaced with the second distance measuring sensor 122.

  Thus, even in the intermediate beam support type shield machine, two types of the first distance sensor 120 and the second distance sensor 122 are used, and based on the outputs from these two distance sensors, a complicated By eliminating the need for arithmetic processing, the operation panel 30 can be used effectively without the need for additional arithmetic processing equipment, while achieving a simple structure that achieves low cost and space savings as a whole, and accurately determines the front load of the cutter. Can be detected. Further, the shield jack 10 can be appropriately decelerated or stopped based on the outputs from the two distance measuring sensors, and the excavator can be sufficiently protected. In particular, when the second distance measuring sensor 122 is equal to or greater than a predetermined value and the cutter front load F2 is an extremely large value, the operation of the shield jack 10 is stopped, so that the excavator is reliably protected without being damaged. be able to.

As a result, even in the case of a shield excavator of the intermediate beam support type, by applying the cutter front load detection method and apparatus according to the present invention, the cutter front load can be accurately detected while having a simple configuration. Can be reliably protected.
Although the description of the embodiment according to the present invention is finished above, the embodiment is not limited to the above, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above embodiment, in the first example, the displacement of the outer surface 11a of the seal member 11 is detected by the first displacement sensor 20 and the second displacement sensor 22, but the first displacement sensor 20 is For example, the displacement of the rear end of the boss 6a or the rear end of the center shaft 4 may be directly detected, and the second displacement sensor 22 may directly detect the displacement of the rear end of the center shaft 4. It may be.

In the above-described embodiment, in the second example, the first distance measuring sensor 120 detects the relative displacement of the turning ring support member 106. However, the first distance measuring sensor 120 detects the displacement of the turning ring 107, for example. It may be something that directly detects.
In the above embodiment, the first displacement sensor 20, the first distance sensor 120, the second displacement sensor 22, and the second distance sensor 122 are used. However, if the displacement can be detected, these displacement sensors and distance sensors are used. However, the present invention is not limited to this, and a simple strain sensor or the like may be used.

In the above embodiment, the speed of the shield jack 10 is limited according to the cutter front loads F1, F2. However, the rotational speed of the cutter head 3 is also limited according to the cutter front loads F1, F2. You may make it do.
In the above embodiment, the center shaft support type shield machine (first example) and the intermediate beam support type shield machine (second example) have been described. Applicable.

  In the above embodiment, the shield excavator has been described as an example, but the present invention is naturally applicable to a propulsion excavator.

1 is a longitudinal sectional view of an excavator according to a first embodiment to which a cutter front load detection method and apparatus according to the present invention is applied. It is a figure which expands and shows the fixed part of a 2nd displacement sensor. It is a flowchart which shows the control routine of the shield jack control which concerns on 1st Example which a cutter front surface load detection part and a shield jack control part perform. It is a flowchart which shows the control routine of the shield jack control which concerns on the modification of 1st Example which a cutter front surface load detection part and a shield jack control part perform. It is a longitudinal cross-sectional view of the excavation machine which concerns on 2nd Example to which the cutter front surface load detection method and apparatus of this invention are applied.

Explanation of symbols

1, 101 Shield frame 2, 102 Bulkhead 3, 103 Cutter head 4 Center shaft (swivel member)
4a Annular projection 5 Cutter bearing 5a Thrust bearing 5b Radial bearing 6 Shaft support member (support member)
6a Boss part 10 Shield jack (propulsion means)
11 Seal member 20 1st displacement sensor (1st displacement detection means)
22 Second displacement sensor (second displacement detection means)
24, 124 Arm member 26 Arm member 30 Operation panel 31 Cutter front load detection unit 32 Shield jack control unit (control means)
105 Cutter support rollers 105a and 105c Thrust roller 105b Radial roller 106 Rotating ring support member (support member)
106a Swivel rail 107 Swivel ring (swivel member)
120 1st ranging sensor (1st displacement detection means)
122 Second distance measuring sensor (second displacement detecting means)

Claims (6)

A cutter head that cuts debris by rotation is rotatably supported by a frame through a support member by a rotating member, and the frame is supported by the propulsion unit, whereby the cutter head is moved together with the frame, the support member, and the rotating member. It is a cutter front load detection method of an excavator that advances while cutting earth and stones,
Detecting a first displacement in a thrust direction of the swivel member or the support member with respect to the frame;
Detecting a second displacement in the thrust direction of the swivel member relative to the support member;
A cutter front load detection method for an excavator, wherein when at least one of the first and second displacements is greater than each initial value, the cutter head is considered to have received a cutter front load corresponding to the displacement. A cutter head that cuts debris by rotation is rotatably supported by a frame through a support member by a rotating member, and the frame is supported by the propulsion unit, whereby the cutter head is moved together with the frame, the support member, and the rotating member. A cutter front load detection device for an excavator that advances while cutting earth and stones,
First displacement detection means for detecting a first displacement in a thrust direction of the swiveling member or the support member with respect to the frame;
Second displacement detection means for detecting a second displacement in the thrust direction of the swivel member with respect to the support member;
A cutter front load detecting device for an excavator, wherein when at least one of the first and second displacements is larger than each initial value, the cutter head receives a cutter front load corresponding to the displacement.   3. The cutter front load detection device for an excavator according to claim 2, wherein each of the first displacement detection means and the second displacement detection means includes a displacement sensor or a distance measuring sensor. A cutter head that cuts debris by rotation is rotatably supported by a frame through a support member by a rotating member, and the frame is supported by the propulsion unit, whereby the cutter head is moved together with the frame, the support member, and the rotating member. An excavator that advances while cutting earth and stone,
First displacement detection means for detecting a first displacement in a thrust direction of the swiveling member or the support member with respect to the frame;
Second displacement detection means for detecting a second displacement in the thrust direction of the swivel member with respect to the support member;
Control means for controlling the propulsion speed of the propulsion means according to the displacement when at least one of the first and second displacements is greater than each initial value;
An excavator characterized by having   When only the first displacement larger than the initial value is detected by the first displacement detection means, the control means limits the propulsion speed of the propulsion means according to only the first displacement, and the second displacement 5. The excavator according to claim 4, wherein when the second displacement larger than the initial value is detected by the detection unit, the propulsion speed of the propulsion unit is more largely limited according to the second displacement.   6. The excavator according to claim 5, wherein the control unit stops propulsion by the propulsion unit when a second displacement of a predetermined value or more is detected by the second displacement detection unit.

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