JPH1061384A - Wear diagnosis method of cutter of tunnel excavating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To diagnose wear amount of a cutter main body quantitatively by measuring propulsion speed of a tunnel excavating equipment and torque and number of revolutions of a cutter head and obtaining excavation coefficient which indicates amount of work done by the excavating equipment. SOLUTION: A disclike cutter head 2 is rotated at a front end of a shield frame 1 of a shield machine to excavate the ground G. An acceleration sensor which detects excavation sound is attached to a rear face of a bulkhead 7 of a sealed chamber 3. Changes of the intensity of an excavation sound signal AE are obtained from an acoustic signal from the acceleration sensor in the ground and are adopted as feature parameters which indicate the hardness of the ground to be excavated. Jack propulsion speed V is measured by a jack sensor attached to a hydraulic jack for propulsion 6, and rotation torque T and the number of revolutions ω of the cutter head 2 are measured by a torque sensor and a number of revolution sensor. Excavation coefficient is determined based on propulsion speed V, torque T, and number of revolutions ω, and wear amount W of a cutter main body is diagnosed quantitatively to improve diagnosis accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavation work for a tunnel or water supply and sewerage by a tunnel excavation machine such as a shield machine or a tunnel boring machine (TBM).
The present invention relates to a method for quantitatively diagnosing a wear amount of a cutter for excavating a ground.

[0002]

2. Description of the Related Art In excavation work such as tunnels and water supply and sewerage by a shield method, a cutter body on a cutter head which excavates the ground by rotating in front of a shield excavator wears and wears over time as the ground is cut. If the cutter body is worn to some extent because it is damaged, it needs to be replaced. However, exchanging the cutter body underground is complicated and requires large-scale construction, so if it is replaced more frequently than necessary, the number of interruptions of excavation work will increase and the construction period will increase, and the cost will increase. If the replacement frequency is too low, the cutter body will be worn out of tolerance and the excavation speed and drilling efficiency will be significantly reduced.Therefore, the health of the cutter body will be constantly diagnosed on the ground, and the replacement time will be determined. It needs to be determined accurately.

Conventionally, as a method of diagnosing the soundness of the cutter body, a conventional method of diagnosing the cutter body with excavation has been based on the assumption that the degree of progress of wear of the cutter body is substantially proportional to the amount of sliding with the ground. A method of measuring a distance is employed. According to this method, it is diagnosed that the harder the ground is, the more the orbital distance of the cutter body at a constant excavation distance increases and the wear proceeds.

[0004]

However, the wear of the cutter body is actually governed by the operating conditions of the tunnel excavating machine and the hardness of the ground to be excavated. It is difficult to diagnose the progress of the wear of the cutter body with high accuracy and accurately estimate the replacement time using the data of only the moving distance.

SUMMARY OF THE INVENTION The present invention has been made under the above circumstances, and the technical subjects thereof are that the amount of work performed by a tunnel excavating machine on the ground to be excavated and the amount of wear of a cutter body are reduced. And to improve the diagnostic accuracy.

[0006]

According to the present invention, there is provided a method of diagnosing wear of a cutter of a tunnel excavating machine, comprising: determining a propulsion speed v, a torque T of a cutter head, and a rotational speed ω of the cutter head of the tunnel excavating machine excavating underground. It is measured, to define the drilling coefficient K _T from these values, as an index of the drilling coefficient K _T, and the wear amount w of the cutter body that is disposed on the cutter head intended to quantitatively diagnose and it is intended to determine the amount of wear the cutter has reached the allowable limit when the integrated value of K _T ² has reached a predetermined value.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In excavation work for tunnels, water supply and sewerage, etc., in order to manage the operation status of tunnel excavation machines,
It measures various mechanical quantities. Of these measurement data, the basics for evaluating the excavating performance of the excavating machine are the total thrust F, the cutter torque T, the propulsion speed v of the propulsion jack, and the rotation speed ω of the cutter head. Excavation of hard rock by tunnel boring machine (TBM)
It is found that the following equation holds between the cutter torque T and the excavation distance P per one rotation of the cutter head. T = K _T P ⁿ ··········· In the above formula, the type of rock to be excavated and the geometric shape and dimensions of the cutter body Independently, the index n is 1.0
The coefficient K _T reflects the properties of the ground to be excavated and the geometrical properties of the cutter body.

The above equation is an empirical equation for a TBM for excavating hard rock. In the present invention, it is assumed that this empirical equation can be applied to the excavation of the ground including conglomerate, sandstone and the like. The coefficient K _T is defined by the following equation. K _T = T / P = T · ω / v Here, the formula assumes that the exponent n in the formula is 1.0.

In the present invention, the coefficient K _T defined by the equation is called an excavation coefficient, and this is adopted as an effective index for determining cutter replacement. As described above, the excavation coefficient K _T depends on both the mechanical properties of the ground to be excavated and the geometric conditions of the cutter bodies arranged on the cutter head.
Therefore, if a change occurs in the excavation coefficient K _T in a section where the wear of the cutter body can be considered to be constant, it means that a change in the ground to be excavated, that is, a change in the geology or a change in the mechanical properties of the ground. It is expected to have occurred. Also, if the excavation coefficient K _T changes despite the fact that the ground to be excavated belongs to the same stratum section, then the geometrical properties of the cutter have changed at that time, and specifically, the wear of the cutter body has been reduced. It may have evolved.

The physical meaning of the excavation coefficient K _T related to the cutter torque defined by the equation will be described from another viewpoint. As is apparent from the equation, K _T is out of work tunneling machine is against ground to drilling by a unit excavation length, represents the contribution based on the rotation of the cutter head. Here, this is called rotary excavation work. That is, K _T
Is the rotary excavation work per unit excavation length, so that the work W _T when excavating by an arbitrary distance L starting from the time of replacement of the cutter body is given by integrating _KT . That is,

(Equation 1)

Here, it is assumed that the amount of wear w of the cutter body is expressed by the following equation because it is related to the rotary excavation work performed by the tunnel excavating machine on the ground to be excavated.

That is, if n = 1 in this equation, w = cW _T
Which means that the wear amount is proportional to the rotary excavation work. If n = 2, the amount of wear is proportional to the integrated value of the square of the rotary excavation work K _T per unit excavation length. The index n is expected to be n ≧ 1, which is determined based on the construction results, and the coefficient c is similarly determined based on the construction results.

When the equation is established, the criterion for the exchange of the cutter body is expressed by the following equation. That criterion cutter replacement, when defined by the maximum value w _max wear amount allowed, decision criteria,

## EQU3 ## This formula should be replaced when the integrated value of K _T ⁿ reaches w _max / c from the time when the cutter body was replaced last time (when the right side and the left side become equal in the formula). It indicates that there is.

In the criterion of the equation, it is necessary to grasp the index n and the coefficient c in advance. In this case, the index n and the coefficient c can be obtained by using the past construction results of the same type of tunnel excavating machine, if any. Further, if there is no construction performance by this type of tunnel excavating machine, it is estimated in the early stage of excavation from the excavation data and the actually measured value of the wear amount of the cutter body in accordance with a method described later in an embodiment.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a rock drilling shield excavator having an outer diameter of 2140 mm, a total thrust of up to 4704 kN (480 tf), and a cutter head rotational torque of up to 353 kNm (36 tfm) is used. Total length of 1816m (converted to the number of rings in the primary lining segment calculated from the starting position of the shield
An example of construction of a sewer main line facility (distance equivalent to a ring) will be described. As shown in FIG. 1, the shield excavator attaches a disk-shaped cutter head 2 to the shield frame 1 at the front end in the excavation direction of a substantially cylindrical shield frame 1.
The ground G is excavated by rotating about the center of the axis, and the excavated soil (slipping) G ′ generated by this is inserted into a closed chamber 3 on the rear surface of the cutter head 2 through a slit (not shown) formed in the cutter head 2. It is stirred with the rotation of the cutter head 2 and is continuously conveyed from the closed chamber 3 to a discharging gate 5 via a screw conveyor 4 extending rearward. Through the ground.

At the rear end of the shield frame 1 in the excavation direction, a plurality of segments S are assembled in an annular shape by an unillustrated erector on the excavated inner wall, and subjected to a primary lining to withstand earth pressure. I have. Then, after assembling the segment S for one ring, the propulsion hydraulic jack 6 is applied to the front end of the segment S and pressed, so that the reaction force causes the shield machine to reach the axial length L for one ring. After digging for the equivalent constant distance,
The cycle of the process of assembling the segment S for the next one ring is repeated.

An acceleration sensor for detecting the sound of excavation in the cutter head 2 is attached to the rear surface of the partition wall 7 forming the closed chamber 3.
Is provided with a jack sensor for measuring the jack propulsion speed v. The drive system of the cutter head 2 includes a torque sensor for measuring the rotational torque T of the cutter head 2 and a rotational speed ω of the cutter head 2. A rotation speed sensor for measuring is attached. The propulsion speed v, the torque T, the number of revolutions ω, and the like were measured for each excavation length of 25 cm and supplied to a computer installed in a control room on the ground, and the computer performed various calculations.

FIG. 2 is a front view of the rock drilling shield excavator shown in FIG. 1. The cutter head 2 has 10 sets of disk cutters 21 as a cutter body and 5 × 6 rows of tool bits 22. = 30 pieces, other center cutter 2
3. A gauge cutter 24 and the like are attached. Each of the disk cutters 21 has a diameter of 305 mm, and its allowable wear limit is set at 18 mm.

According to the pre-boring survey, the geological composition of the construction zone is, as shown in FIG.
3 was a stratum composed of mudstone and conglomerate, and about 1/3 of the reaching side was a gravel layer. The mudstone is generally weathered and is a silty or sandy mudstone. Conglomerate is composed of sand, mainly consisting of 10 to 30 mm round pebble, and 80 to 200 mm cobblestone is 3 to 3 m / m.
There are four dots. The gravel layer in the latter half of the construction area is mainly composed of 5-60mm gravel and 80-300mm cobblestone.

The ground excavation noise generated by the cutter head 2 is small in a soft clay soil layer and increases as the ground becomes harder. Therefore, unnecessary frequency components are cut off from an acoustic signal detected by an acceleration sensor on the rear surface of the partition wall 7 to form a waveform. The digging sound signal AE intensity for each fixed digging distance obtained by the processing was adopted as a characteristic parameter representing the hardness of the digging ground. Figure 4 shows each ring (digging progress) for almost all sections from the 40 ring position to the excavation completion position after starting.
The change of the excavation sound signal AE intensity for each is shown.

That is, according to FIG. 4, the excavation sound signal AE intensity has a small value of about 1 V up to about 1150 rings corresponding to the section where the shield machine is excavating in the mudstone and conglomerate layer shown in FIG. No significant change was observed.
After that, from around 1150 ring, the AE intensity of the excavation sound signal sharply increased in response to the transition to the gravel layer containing cobblestone, and the value changed drastically from 1.5 to 4.5 V. This indicates that there is a difference in the hardness of the ground. In particular, the AE intensity of the excavation sound signal is remarkably large in the vicinity of the 1450 to 1550 ring, which indicates that the ground is considerably hard.

In this case, it is presumed that the abrasion and damage of the cutter are slight since the excavation is performed in the soft mudstone and conglomerate layers for a while after the vehicle starts, but the excavation is performed in such a soft ground. However, since the wear progresses reliably, the first point when excavating to the position equivalent to the 781 ring
The second cutter exchange was performed. After that, it was estimated that the wear progressed slightly due to the transition to the gravel layer near the 1150 ring, and the second cutter exchange was performed when the excavation reached the position corresponding to the 1304 ring. After that,
Since it is estimated that the digging sound signal AE intensity becomes remarkably large from around 1400 ring and the ground corresponds to a considerably hard section, and the disk cutter 21 is estimated to be considerably damaged,
After the second cutter exchange, the third cutter exchange was performed at the point when only 141 rings were excavated and excavated to a position equivalent to 1446 rings.

The amount of wear of the disk cutter 21 (hereinafter referred to as the amount of wear of the cutter) was measured a total of four times when each cutter was replaced and when excavation was completed with 1779 rings. FIG.
Shows the measurement results. The horizontal axis in the figure shows the position of each cutter ring of the disk cutter 21 as a distance measured from the center of the cutter head 2. According to FIG. 5, there is a tendency that the amount of wear increases as the peripheral speed increases with increasing distance from the center of the cutter head 2 (away from the center). The average value of the cutter wear measured at the time of the first disk cutter replacement is
8.9mm, average cutter wear measured at the second cutter change is 11.3mm, average cutter wear measured at the third cutter change is 15.2mm, measured at the end of excavation The average value of the obtained cutter wear amount was 12.6 mm.

Next, with respect to this example of construction, the wear diagnosis method according to the present invention was applied to evaluate the cutter replacement time. FIG. 6 shows the transition of the excavation coefficient K _T calculated for each ring based on the equation.

That is, according to FIG. 6, similarly to the digging sound signal AE intensity described above, the digging coefficient K is up to about 1150 ring positions corresponding to the section where the shield machine is digging in the mudstone and conglomerate layer. _{Although T} remains at a relatively low level, the excavation coefficient _KT rapidly increases at the same time as the material moves into the gravel layer, and thereafter becomes high until the excavation end position. However, when observing this in more detail, the excavation coefficient _KT value after the 1450 ring position was lower than before that even during the excavation process in the gravel layer, and the excavation sound signal that maintained a high level It can be seen that the trend is slightly different from the transition of the AE intensity.

For example, as shown by reference numeral A in FIG.
There is a region where the digging sound signal AE intensity is slightly reduced up to about 1300 rings, that is, the region A shows that the ground is somewhat soft, while referring to FIG. _KT has a large value in the area A. The reason why the excavation coefficient _KT is large even though the ground is soft is presumed to be that the excavation ability has decreased due to wear and damage. Also, for example, as shown by reference numeral B in FIG. 4, there is a region where the digging sound signal AE intensity is extremely large from 1450 to 1550 ring, that is, in this region B, the ground is extremely hard. Referring to FIG. 6, the excavation coefficient K _T
Represents a small value in the area B. The fact that the excavation coefficient K _T is small despite the fact that the ground is hard is that
It is presumed that the excavation ability was recovered by replacing the cutter at the position corresponding to the 1446 ring.

Next, attention is paid to the relationship between the cutter wear amount and the integrated value of K _T ⁿ . FIG. 7 shows K starting from each cutter exchange position.
_It shows the transition of the integrated value of _T ⁿ , that is, the entire construction section is divided into four sections at each of the cutter replacement positions, and for each section, K _T ⁿ for n = 1 and n = 2 The integrated value is calculated. FIG. 8 shows the case where n = 2, that is, the integrated value of K _T ² for each section and the average value w _{mean of the} amount of cutter wear generated in that section.
Is shown in comparison with FIG. As is apparent from this figure, the following proportional relationship is found between the integrated value of K _T ² and the average value of the amount of cutter wear.

(Equation 4) If this equation is satisfied, the criterion based on the equation is changed to the following equation.

(Equation 5)

In this embodiment, as shown in FIG.
2.4 × 10 ⁻⁵ , b = 4.8 mm, and as described above, the wear limit w _max of the disk cutter 21 is set to 18 mm, so the limit of the integrated value of K _T ² suggested by the equation is given. Is
5.5 × 10 ⁵ units. However, in practice, w _max = w _mean
Therefore, it is considered that the limit of the integrated value of K _T ² should be suppressed to a slightly lower level. Therefore, w _max = 1.2w
Assuming _mean , the limit of the integrated value of K _T ² suggested by the equation is 4.2 × 10 ⁵ units. Since the actual integrated value of K _T ² in all construction sections is 11.9 × 10 ⁵ units, the number of cutter replacements from the start to the completion of excavation is calculated as 11.9 × 10 ⁵ /(4.2×10 ⁵ ) -1 = 1.8, which means that cutter exchange was good twice. That is, since the cutter was replaced three times in the actual construction, the number of replacements may be reduced by one.

[0028]

According to the present invention, the wear amount w of the cutter body is quantitatively diagnosed by the excavation coefficient K _T representing the amount of work performed by the tunnel excavating machine on the ground to be excavated.
Since it is determined that the wear amount of the cutter has reached the allowable limit when the integrated value of K _T ² has reached a predetermined value, it is possible to improve the determination accuracy of the cutter replacement time.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing the state of construction of a sewer main line facility using a rock-compatible shield excavator as an embodiment to which the present invention is applied.

FIG. 2 is a front view of a cutter head of the rock drilling shield excavator.

FIG. 3 is an explanatory diagram showing a geological configuration of a work section in the sewer main line facility construction.

FIG. 4 is an explanatory diagram showing a change in the digging sound signal AE intensity measured for almost all construction sections from the 40 ring position after the start to the completion of excavation in the sewer main line facility construction.

FIG. 5 is an explanatory diagram showing cutter wear measured at the time of each cutter replacement and at the completion of excavation in the sewer main line facility construction.

FIG. 6 is an explanatory diagram showing a change in an excavation coefficient K _T for almost all construction sections from the 40 ring position after the start to the completion of excavation in the above sewer main line facility construction.

FIG. 7 is an explanatory diagram showing a transition of an integrated value of K _T ⁿ starting from each of the cutter replacement positions.

FIG. 8 is an explanatory diagram showing a relationship between an integrated value of K _T ² for each section obtained by dividing the construction section at each cutter replacement position and an average value w _{mean of the} amount of cutter wear generated in the section.

[Explanation of symbols]

 2 Cutter head 21 Disk cutter (Cutter body)

Claims (2)

[Claims] 1. A to excavating the underground tunnel boring machine advancing speed v, by measuring the rotational speed ω of the torque T and the cutter head of the cutter head, a drill coefficient K _T from these values K _T
= T · ω / v, and the wear amount w of the cutter body disposed on the cutter head is expressed by the following equation; A method for diagnosing wear of a cutter of a tunnel excavating machine, characterized in that the diagnosis is made quantitatively by using a computer. 2. The criterion for determining whether to replace a cutter body according to claim 1, wherein: And determining that the cutter body should be replaced when the integrated value of K _T ⁿ reaches w _max / c from the time when the cutter body was replaced last time. Diagnosis method for cutter wear.