JP4076074B2 - Drilling bit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an excavation bit arranged in a shield cutter of a shield machine. More particularly, the present invention relates to a drill bit used when cutting concrete or mortar walls reinforced with fibers.
[0002]
[Prior art]
The shield machine usually excavates earth and sand with a teeth bit, but when starting from the starting shaft or reaching the reaching shaft, the reinforced concrete or mortar constituting the starting shaft and the reaching shaft must be cut and penetrated.
However, the shield machine does not have the ability to cut and penetrate concrete or mortar reinforced with reinforcing bars.
For this reason, in the conventional shield method, a breaker is used to drill through holes for passing through the shield machine in advance by using concrete or mortar containing reinforcing bars in the start and end shafts to break through the shield machine, thereby starting the shield machine from the start shaft. , I had reached the reach shaft.
However, if concrete or mortar containing reinforcing bars forming the start shaft or the reaching shaft is drilled, groundwater or earth and sand will flow into the start shaft or the reaching shaft through the through hole.
In order to cope with this, it was necessary to improve the ground at the start site near the start shaft and at the reach site near the reach shaft.
[0003]
In order to solve such a problem, a starting and reaching method of a shield using a new material (hereinafter referred to as “new material concrete wall” in this specification) has been proposed.
In such a new material concrete wall construction method, a conventional material such as carbon fiber (CFRP) or a place where a breaker has been used (a place where the shield machine exits from the start shaft or a place where the shield machine enters the reach shaft) is used. It consists of concrete or mortar reinforced with glass fiber (GFRP).
[0004]
The shield machine does not cut the rebar with a normal bit, but drills concrete or mortar reinforced with carbon fiber (CFRP) or glass fiber (GFRP) by providing a bit called a new material concrete wall cutting bit, Can be cut through.
Therefore, there is no need to use a conventional breaker, and the situation where groundwater and gravel enter the shaft when the shield machine goes out of the start shaft or enters the shaft is avoided. I can do it.
And the ground improvement in the start site | part in the vicinity of a start shaft and the reach | attainment site | part near a reach shaft becomes unnecessary.
[0005]
Here, the reinforcing material for FRP described above has a shape like a H-shaped steel which is a structural member, and is contained in concrete or mortar.
[0006]
However, it has been found that the new material concrete wall construction method has the following problems.
That is, when cutting with a bit for excavating concrete or mortar reinforced with CFRP or the like in the new material concrete wall construction method (new material concrete wall cutting bit), the FRP in the concrete or mortar has toughness. It gets entangled with the cutter and is not cut. And it will be in the state which adhered and adhered to concrete or mortar.
If the bit for cutting a new material concrete wall is rotated as it is, the FRP will be pulled and shredded. As a result, a large lump of concrete or mortar is removed from the shaft with the FRP that has been shredded in length.
[0007]
When a long and shredded FRP or a large block of concrete or mortar is removed, it will be large when passing through the removed drainage discharge line (for example, a discharge pipe in the case of a muddy water shield). A long FRP with a lump is entangled to block the passage.
[0008]
Moreover, as a result of the bit for cutting a new material concrete wall biting into the FRP having toughness, the bit is worn and cannot be cut.
Furthermore, when the new material concrete wall construction method is used for the reaching shaft, the shield machine may not be able to enter the reaching shaft.
[0009]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-described problems of the prior art, and the cut fiber becomes longer than necessary when cutting concrete or mortar wall reinforced with fiber. An object of the present invention is to provide an excavation bit that can be prevented, and can be prevented from becoming a large lump when the concrete or mortar to which fibers are attached is removed.
[0010]
[Means for Solving the Problems]
[0011]
According to the present invention, in a plurality of excavation bits arranged radially from the center of the shield cutter (100) of the shield machine, a pair of trapezoidal cutting bits (21N, 22N) are arranged opposite to each other in the radial direction (R), and the bases (21Na, 22Nb) of the trapezoidal cutting bits (21N, 22N) face each other, but their ends are in the rotational direction (T). Is displaced by a distance (δ), the bottom (21Na) of one cutting bit (21N) is recessed, and the top (22Nb) of the other cutting bit (22N) is recessed, The cutting edges (21Nc, 21Nd) of the cutting bit (21N) and the cutting edges (22Nc, 22Nd) of the other cutting bit (22N) face each other (21Na, 22Nb), and both cuttings Tsu bets (21N, 22N) are both viewed from the upper surface eight characters shaped cutting blade (21Nc, 21Nd, 22Nc, 22Nd) existent region (21Nc, 22Ne) of the cutting portion exists between. (Claim 1: FIGS. 5 and 6)
[0012]
Further, according to the present invention, in a plurality of excavation bits arranged radially from the center of the shield cutter (100) of the shield machine, a pair of trapezoidal cuts having the same shape as seen from above on the base (25). The bits (21N) are arranged in the same direction in the radial direction (R), the cutting bits (21N) are offset by a distance (δ) in the rotational direction (T), and their trapezoidal cutting bits (21N ) Of the cutting bit (21N) has an eight-letter shape when viewed from above, and the bottom side (21Na) of the cutting bit (21Nd) has a rectilinear shape. There is a region (21Nf) where no cutting portion exists between them. (Claim 2: FIG. 7)
[0013]
Since the pair of excavation bits are displaced back and forth in the rotational direction (δ), for example, when cutting concrete (55) reinforced with FRP (50) or mortar, the pair of bits (21N, 22N , Or 21N, 21N).
Rather than hitting two bits at the same time (starting to cut FRP), after one bit (21N) starts cutting, the other bit (22N) starts cutting with a time lag when FRP ( 50) is not pulled out.
In other words, the time during which the two bits (21N, 22N, or 21N, 21N) simultaneously pull the FRP is shortened, and the amount by which the FRP (50) is pulled out is reduced.
And since the time which hits one place shifts | deviates slightly, concrete (55) is crushed finely.
[0014]
The cutting speed of the new material concrete wall is increased by the synergistic effect of reducing the space between the bits and shifting the pair of bits (21N, 22N, or 21N, 21N) back and forth on the cutter disk surface. In addition, since the generated cutting pieces are reduced, troubles such as blockage in the drainage equipment can be prevented.
[0015]
Here, it is also possible to replace only one part of the shield cutter (100), for example, a new material concrete wall cutting bit (18) existing in a predetermined region.
Of course, all the bits of the shield cutter (100) can be configured to be replaceable.
[0016]
Here, it is preferable that the new material concrete wall cutting bit (20N) to which the present invention is applied protrudes more in the traveling direction than the teeth bit (20).
If comprised in this way, when penetrating the start shaft, the new material concrete wall cutting bit (20N) hits first and the new material concrete (55) in which the rod-like CFRP (50) is embedded is cut. At this time, although the new material concrete wall cutting bit (20N) is damaged, the teeth bit (20) used for ground excavation (because it does not excavate concrete 55 or mortar reinforced with FRP 50 when the shaft starts) The ground can be excavated without being damaged.
[0017]
Thus, according to the present invention, it is possible to solve the problems of the new material concrete wall construction method while enjoying the advantages of the new material concrete.
[0018]
Here, it is preferable that the new material concrete wall cutting bit (20N) to which the present invention is applied protrudes more in the traveling direction than the teeth bit (20).
If comprised in this way, when penetrating the start shaft, the new material concrete wall cutting bit (20N) hits first and the new material concrete (55) in which the rod-like CFRP (50) is embedded is cut. At this time, although the new material concrete wall cutting bit (20N) is damaged, the teeth bit (20) used for ground excavation (because it does not excavate concrete 55 or mortar reinforced with FRP 50 when the shaft starts) The ground can be excavated without being damaged.
[0019]
Thus, according to the present invention, it is possible to solve the problems of the new material concrete wall construction method while enjoying the advantages of the new material concrete.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0021]
First, a reference example of the present invention will be described with reference to FIGS.
On the front surface of the shield cutter 100 in FIG. 1 (the right half is omitted), rows AD of the new material concrete wall cutting bits (cutters) 20N arranged radially from the center of the shield cutter 100 are shown in FIG. J, a row of bits 18 with an exchange device (horizontal row in the figure) E, and a row T of teeth cutters 20 which are arranged on both sides of the rows A to J and have the largest number and excavate the ground. The left side of the figure shows a special outer cutter 20D arranged at the center of a row of new material concrete wall cutting bits adjacent on the outer periphery of the shield cutter 100 and a row of new material concrete wall cutting bits adjacent in the vicinity of the outer periphery. On the half side, new material concrete wall cutting bits 20N arranged at four locations are attached.
In the illustrated reference example, the new material concrete wall cutting bit 20N has a new shape, and the cutter bit (tooth bit: bit for ground excavation) 20 has a normal shape.
[0022]
With reference to FIG. 2 and FIG. 3, the features of the cutting edge shape of the new material concrete wall cutting bit 20N of the reference example will be described. In addition, the code | symbol U in FIG. 3 shows the attachment side to a shield cutter.
[0023]
FIG. 9 shows a cross-sectional shape in the radial direction of a conventional new material concrete wall cutting bit 20J to be compared.
The conventional new material concrete wall cutting bit 20J has, for example, a single cutting portion (cutting edge) 30 having a radial dimension L3 of 60 mm, and is in a radial direction (left-right direction in FIG. 9) with an adjacent bit. The distance between the surfaces, that is, the distance between the bits in the radial direction (in other words, the length in the radial direction of the region where no bits exist) L1 is, for example, 90 mm.
[0024]
On the other hand, in the new material concrete wall cutting bit 20N according to the reference example of FIG. 2, the excavation part (cutting edge) 30 at the tip of the bit is radially inward due to the non-cutting region 40 where no cutting part exists (in FIG. 2). It is divided into a region 30a on the right side and a region 30b on the radially outer side (left side in FIG. 2).
The radial lengths L3 and L4 of the regions 30a and 30b are both 35 mm, and the radial length L2 of the non-cutting region 40 is 40 mm. Furthermore, the distance (surface distance) L1 between adjacent bits is 40 mm.
That is, the distance L1 between the surfaces in the radial direction is reduced from 90 mm of the conventional new material concrete wall cutting bit 20J to 40 mm of the new material concrete wall cutting bit 20N according to the reference example.
In other words, the new material concrete wall cutting bit 20N (FIG. 2) according to the reference example has a distance (between the faces) between adjacent bits as compared to the conventional new material concrete wall cutting bit 20J (FIG. 9). The radial dimension of the region 40 where the distance (L1) or the cutting part (cutting edge) of the tip of the bit for cutting a new material concrete wall does not exist is small.
[0025]
With reference to FIG. 4, the effect of the small radial dimension of the region 40 where the distance between adjacent bits (surface distance) L1 or the cutting portion (cutting edge) at the tip of the bit for cutting a new material concrete wall does not exist. explain.
FIG. 4 is a partial front view of a part of the left side including a place having an FRP reinforcing portion and a horizontal position passing through the center of the shield cutter in the start shaft.
Region X surrounded by a thick line in FIG. 4 is a concrete (or mortar) 55 reinforced with FRP 50 in the new material concrete wall construction method by a shield machine equipped with a conventional new material concrete wall cutting bit 20J (FIG. 9). The cut piece of FRP50 at the time of cutting is shown.
The reinforcing part of the FRP 55 has a ladder-like vertical crosspiece 55a and a horizontal crosspiece 55b as shown in the figure.
[0026]
This cut piece (region X) includes a trajectory (shaded region Y) through which the inter-surface distance portion (non-cut portion) of the new material concrete wall cutting bit passes, and a region where the FRP 50 is disposed (in the horizontal direction). It is determined in the area where the hatched area Z) overlaps. The length of the FRP 50 fracture piece (the length of the cut piece in the direction of arrow V) is the trajectory (shaded area Y) through which the inter-surface distance portion (non-cutting portion) of the new material concrete wall cutting bit 20J passes. If the width “ε” of the is shortened, it is shortened.
When the conventional new material concrete wall cutting bit 20J (distance between faces of 90 mm) shown in FIG. 9 is used, the length of the broken piece reaches 2 m at the maximum when the diameter of the shield cutter 100 is 13 m. did. However, as shown in FIG. 2, when the bit according to the reference example (distance between the faces of 40 mm) is adopted, the diameter is reduced to 1 m at maximum when the diameter of the shield cutter 100 is 13 m.
[0027]
Thus, the length of the FRP fragment can be shortened by reducing the inter-surface distance. Then, by shortening the length of the FRP fragment, it is possible to solve the problem of the FRP fragment being entangled and blocking the earth and sand discharge passage.
In addition, if the FRP fragment is shortened, the size of the concrete or mortar lump that adheres and is removed is also reduced, and the problem of blockage of the discharge passage by the lump is solved.
[0028]
Here, when the non-cutting region 40 where no cutting site exists is provided at the tip 20 of the new material concrete wall cutting bit 20N, when the shield cutter 100 rotates, the cutting site of the tip 20N of the new material concrete wall cutting bit 20N is changed. The trajectory that passes through cannot cover the entire excavation surface.
That is, there is an area that is not cut by the bit 20N in the shield passage area of concrete 55 or mortar reinforced with FRP 50 or the like.
If the normal cutter bit 20 is used, the soil cannot be excavated unless the entire area of the face is covered with the plurality of cutter bits 20, and therefore the excavator cannot be excavated.
In contrast, the new material concrete wall cutting bit 20N does not cover the entire face, and even if the region 40 (not cut by the new material concrete wall cutting bit 20N) is present, Since the area 40 is broken and collapsed when the other area is cut with the new material concrete wall cutting bit 20N, there is no problem in excavation, progress, and penetration by the shield machine.
[0029]
Although not shown, the new material concrete wall cutting bit 20 </ b> N protrudes more in the traveling direction than the teeth bit (ordinary cutter bit) 20.
When penetrating the start shaft, the new material concrete wall cutting bit 20N hits first, and the new material concrete 55 in which the rod-shaped FRP 50 is embedded is excavated.
Although the new material concrete wall cutting bit 20N is damaged by the concrete excavation, the teeth bit 20 does not cut the concrete when the shaft starts, so the damage is small and the ground can be excavated without being damaged.
[0030]
A first embodiment of the present invention will be described with reference to FIGS.
In FIG. 5, a pair of adjacent new material concrete wall cutting bits (two new material concrete wall cutting bits arranged to face each other) 21N in the radial direction R of the shield cutter on the base 25 of the bit. , 22N.
In the first embodiment, the pair of bits 21N and 22N are displaced by the distance δ with respect to the rotation direction T.
The difference between the pair of new material concrete wall cutting bits 21N and 22N is that, in FIG. 5, the bottom side 21Na of one (21N) is depressed, whereas the top side 22Nb is depressed in the other (22N). It is that you are.
[0031]
Rather than hitting two bits 21N and 22N simultaneously (starting to cut FRP), it is more likely that FRP pulls when one bit 21N starts cutting and the other bit 22N starts cutting with a time difference. I can't pull it out.
Since there is a distance δ in the rotational direction, the time for hitting one place is slightly shifted, and the time for the two new material concrete wall cutting bits (a pair of bits) 21N and 22N to simultaneously pull the FRP is shortened. .
[0032]
When concrete and mortar reinforced with FRP by two new material concrete wall cutting bits 21N and 22N are split at once, a large lump is formed and long fibers are drawn.
On the other hand, in the first embodiment, a time difference is generated by the amount of deviation δ, the amount of FRP pulled out decreases, and FRP and concrete (or mortar) are finely crushed.
[0033]
The cutting speed of the fiber reinforced concrete (or mortar) wall can be increased by the synergistic effect of reducing the space between the bits and shifting the pair of bits back and forth on the cutter disk surface. By reducing the size of the generated cutting piece, it is possible to prevent troubles such as blockage in the drainage equipment.
[0034]
Here, the amount of deviation δ in the rotational direction is determined by the size of the holder and the bit. The displacement amount δ is preferably as large as possible.
[0035]
Next, a second embodiment will be described with reference to FIG.
The second embodiment shown in FIG. 7 is different from the first embodiment shown in FIGS. 5 and 6 in that two pairs of new material concrete wall cutting bits 21N having the same shape are shifted by δ in the rotational direction as a pair of bits. This is an example of arrangement, and the others are the same as in the first embodiment.
[0036]
In the present invention, the excavation bit (20N) or the pair of excavation bits (21N, 22N, or 21N, 21N) is preferably configured to be replaceable.
Here, regarding the bit exchange, it is preferable to adopt the method disclosed in Japanese Patent Laid-Open No. 2001-20667.
[0037]
With reference to FIG. 8, the cutting bit replacement apparatus of the reference example will be described.
The reference example of FIG. 8 is a reference example in which a new material concrete wall cutting bit (reference numeral 18 in FIG. 1 and 19 in only the left half of the shield cutter 100 in FIG. 1) is replaceable. is there. Specifically, this is a technique disclosed in Japanese Patent Application Laid-Open No. 2001-20667 by the present applicant, and is a technique for replacing a worn new material concrete wall cutting bit with a new one.
[0038]
In FIG. 8, a bit switch generally indicated by reference numeral 1 includes a rectangular case 3 having two opposite surfaces open, and a case cover 4 detachably attached to one open surface of the case 3. Have.
Inside the case 3, a ball valve 7 that is supported on both sides by an annular support member 16, 16 and a bit that is slidably mounted in an inner hole 7 a provided in the ball valve 7. A fixed shaft 12 and a cutter bit 18 attached to the tip of the bit fixed shaft 12 via a water stop piston 19 are included.
When the bit fixing shaft 12 is detached from the ball valve 7, the cut bit 18 fitted with the water stop piston 19 is configured to be housed in the inner hole of the ball valve 7.
[0039]
By using the above-described bit exchanging device 1, a special bit (a replaceable new material concrete wall cutting bit 18) and a normal cutter bit (a teeth cutter 20) can be appropriately exchanged depending on the state of the ground. It is.
[0040]
That is, a rectangular case (3) having two opposite surfaces open, a case cover (4) removably attached to one open surface of the case (3), and the case (3) A ball valve (7) supported on both sides by a square annular support member (16, 16) so as to be rotatable, and an inner hole (7a) provided in the ball valve (7) are slidable. A bit fixing shaft (12) to be mounted, and a cutter bit (18) mounted to the end of the bit fixing shaft (12) via a water stop piston (19). A bit exchanging device (12) configured such that when the 12) is removed from the ball valve (7), the cutter bit (18) fitted with the water stop piston (19) can be stored in the inner hole of the ball valve (7). The bit exchange is preferably performed according to 1).
[0041]
As described above, if the excavation bit is configured to be replaceable, the worn new material concrete wall cutting bit (20N) can be replaced with a new one.
For example, in the case of a new material concrete wall cutting bit (20N), replace the damaged bit (20N) by cutting concrete (55) reinforced with FRP (50) or mortar when leaving the start shaft. By cutting the concrete (55) or mortar reinforced with the FRP (50) constituting the reaching shaft, it is possible to ensure that the shield machine surely enters the reaching shaft.
[0042]
Furthermore, the special bit (20N) and the normal cutter bit (20) can be appropriately exchanged depending on the state of the ground.
Here, it is also possible to replace only one part of the shield cutter (100), for example, a new material concrete wall cutting bit (18) existing in a predetermined region.
Of course, all the bits of the shield cutter (100) can be configured to be replaceable.
[0044]
The illustrated embodiment is merely an example, and is not intended to limit the technical scope of the present invention.
For example, in the illustrated embodiment, only the new material concrete wall cutting bits 20N, 18 are formed in a new shape, but not only the special bits such as the new material concrete wall cutting bits 20N, 18 but Even this teeth bit 20 can be applied with the new shape.
In addition, the above description is based on the premise that the concrete 55 or mortar reinforced with long fibers (FRP50) is excavated, but the fiber reinforced concrete using short fibers is also as in the present invention. It is possible to excavate with a bit having a configuration.
Further, in the illustrated embodiment, only one part of the new material concrete wall cutting bit 18 is configured to be replaceable, but all of the new material concrete wall cutting bits 20N can be configured to be replaceable. The teeth bit 20 may also be configured to be replaceable.
[0045]
【The invention's effect】
The effects of the present invention are listed below.
(1) Since the radial dimension (distance between faces) between adjacent bits is relatively small, concrete or mortar reinforced with CFRP or GFRP is used, for example, as in the new material concrete wall cutting method. When cutting, the length of the FRP to be cut becomes shorter.
If the FRP to be cut is short, the FRP will be entangled and the discharge passage (sludge passage) of the shield machine will not be blocked, and if the FRP to be cut is short, the FRP is fixed. Since the mass of concrete or mortar is also reduced, the possibility of the discharge passage of the shield machine being blocked by the mass is greatly reduced.
(2) When cutting a pair of excavation bits back and forth in the rotational direction, for example, when cutting concrete or mortar reinforced with FRP, a time difference occurs between the pair of bits, and the two bits are simultaneously The time for performing the action of pulling the FRP is shortened, and the amount of extra FRP pulled out is reduced.
And since the time which hits one place shifts | deviates slightly, concrete is crushed finely.
(3) The cutting speed of the fiber-reinforced concrete (or mortar) wall can be increased by the synergistic effect of reducing the distance between the bits and shifting the pair of bits back and forth on the cutter disk surface. By reducing the generated cutting pieces, it is possible to prevent obstructions such as blockage in the mud drainage equipment.
[Brief description of the drawings]
FIG. 1 is a front view of a cutter disk according to a reference example of the present invention.
FIG. 2 is a cross-sectional view of a cutter bit in a reference example of the present invention.
FIG. 3 is a perspective view of a cutter bit in a reference example of the present invention.
FIG. 4 is a partial front view showing a cutting state at a starting shaft or a reaching shaft in a reference example of the present invention.
FIG. 5 is a top view of the cutter bit according to the first embodiment of the present invention.
FIG. 6 is a perspective view of a cutter bit according to the first embodiment of the present invention.
FIG. 7 is a top view of a cutter bit according to a second embodiment of the present invention.
FIG. 8 is a configuration diagram of a cutter bit exchange device according to a reference example of the present invention.
FIG. 9 is a cross-sectional view of a cutter bit in the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cutter bit changing device 3 ... Case 4 ... Case cover 18 ... Replaceable cutter bit 20 ... Teeth bit 20N ... New material concrete wall cutting bit 30 ... Cutting edge 40... Region where no cutting site exists 50 FRP
55 ... Concrete 100 ... Shield cutter L1 ... Inter-surface distance L2 between bits ... Radial distance in a region where there is no cutting part

Claims (2)

  In a plurality of excavation bits arranged radially from the center of the shield cutter (100) of the shield machine, a pair of trapezoidal cutting bits (21N, 22N) as viewed from above are opposed to each other on the base (25). Arranged in the radial direction (R), the bases (21Na, 22Nb) of the trapezoidal cutting bits (21N, 22N) face each other, but their ends are only a distance (δ) in the rotational direction (T). The bottom side (21Na) of one cutting bit (21N) is recessed, and the top side (22Nb) of the other cutting bit (22N) is recessed, and the cutting bit (21N) The cutting edges (21Nc, 21Nd) and the cutting edges (22Nc, 22Nd) of the other cutting bit (22N) face each other (21Na, 22Nb), and both cutting bits (21N, 2N) Both are viewed from the top eight characters shaped cutting blade (21Nc, 21Nd, 22Nc, 22Nd existent region (21Nc, drilling bits, characterized in that there is 22Ne) of the cutting portion during).   In a plurality of excavation bits arranged radially from the center of the shield cutter (100) of the shield machine, a pair of trapezoidal cutting bits (21N) having the same shape as seen from above on the base (25) are arranged in the radial direction ( R) are arranged in the same direction, their cutting bits (21N) are offset by a distance (δ) in the rotational direction (T), and the base (21Na) of these trapezoidal cutting bits (21N) is recessed. Or the top side is a straight line, and the cutting blades (21Nd) of the cutting bits (21N) have an eight-letter shape when viewed from above, and there is no cutting portion between the cutting blades (21Nd). Excavation bit characterized by the presence of (21Nf).

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