JP6408362B2 - Cutter bit - Google Patents

Description

  The present invention relates to a cutter bit for cutting natural ground.

  The excavator equipped with the cutter bit is used for the construction of the excavation hole and the excavation groove, etc. associated with the shield construction method, the propulsion construction method, the tunnel construction by TBM, the construction of the in-situ pile, the construction of the underground continuous wall.

  The cutter bit is worn as the ground is cut. The worn cutter bit needs to be replaced by interrupting the excavation work. However, interrupting the excavation work hinders the shortening of the construction period and the construction cost.

  Therefore, as a cutter bit that has a function that can withstand long-distance excavation, and that can omit the replacement work or reduce the number of replacement work, a cutter bit having a cutting edge portion in which a plurality of chips are stacked is provided. It is disclosed (for example, see Patent Document 1). According to this cutter bit, when the tip on the surface side is worn and peeled off, a new tip is exposed, so that the cutting ability is maintained for a long period of time.

JP 2008-144541 A

Cracks or chipping may occur in the chip regardless of the strength of the chip due to impact when contacting with gravel, iron ingots, or other hard materials contained in the construction area. A chip with a crack or chip is increased by an impact that repeatedly comes in contact with gravel, causing the chip to fall off.
If the chip falls off, the cutting ability is reduced, which hinders shortening of the construction period.

  The present invention solves the above-described problems, and an object of the present invention is to propose a cutter bit in which cutting ability does not decrease even when a gravel layer or the like is cut.

  In order to solve such a problem, the present invention is a cutter bit comprising a base material and a blade material fixed to the base material, wherein the blade material has a high tip and the position of the blade edge is It consists of a low tip lower than the position of the cutting edge of the high tip, and the high tip and the low tip are alternately arranged in parallel along the direction intersecting the rotation direction of the base material. .

According to such a cutter bit, it is possible to suppress a reduction in cutting ability even when a part of the blade material is cracked or chipped due to contact with gravel.
This is because even if the tip of the high tip is cracked or chipped due to contact with the gravel, the progress of the crack or chip settles in the vicinity of the position of the tip of the low tip, thus suppressing the drop of the high tip itself. It is because it can do.

  If the width of the high chip and the low chip is not less than 5 mm and not more than 50 mm, even if a crack or chip occurs in one of many chips, the width of each chip is small, so the cutting ability The impact on is small.

  The high chip and the low chip may have the same height at the rear end in the rotation direction of the base material, or may have irregularities.

  According to the cutter bit of the present invention, even when a gravel layer or the like is cut, it is possible to perform construction without reducing the cutting ability.

It is a figure which shows the cutter bit which concerns on embodiment of this invention, Comprising: (a) is a perspective view, (b) is a side view. It is a figure which shows the other form of a cutter bit, Comprising: (a) is a perspective view, (b) is a side view. It is a perspective view which shows the usage condition of a cutter bit typically, Comprising: (a) is the state which contacted the gravel to the high chip | tip, (b) has shown the state which the crack produced in the high chip | tip. FIG. 4 is a perspective view following FIG. 3, where (a) shows a state in which chipping has occurred in a high chip, and (b) shows a state in which chipping of the same high chip has progressed.

In the present embodiment, a case where a natural ground including a gravel layer mixed with gravel is excavated using an excavator to which a cutter bit 1 (see FIG. 1) is attached will be described. In the description, the up / down / left / right front / rear directions are unified in the direction shown in FIG. 1 (a), but it is for convenience and does not necessarily match the up / down / left / right front / back directions in the actual use state.
The cutter bit 1 of this embodiment includes a base material 2 and a blade material 3 fixed to the base material 2.

The base material 2 is a so-called shank material.
The base material 2 of the present embodiment is made of a material having a larger expansion coefficient than the hard tips 4 and 5 (the high tip 4 and the low tip 5) constituting the blade member 3, and sufficient rigidity and strength as a structural member. It is configured. In the present embodiment, an SS material, an S45C material, or the like is used as a material constituting the base material 2, but the material constituting the base material 2 is not limited.

  The back surface (upper surface) 21 of the base material 2 is a surface facing the natural ground G (cutting surface), and as shown in FIG. 1 (b), the bottom surface (lower surface) is directed toward the tip (blade material 3) side. It inclines so that it may leave | separate from 23. The front surface 22 of the base material 2 is a front surface in the traveling direction of the cutter bit 1 and is inclined so as to be separated from the rear surface 24 toward the front end (blade material 3) side. Therefore, the corner where the extended surface of the back surface 21 and the extended surface of the front surface 22 intersect is an acute angle, and the corner where the front surface 22 and the bottom surface 23 intersect is an obtuse angle. The bottom surface 23 of the base material 2 is a surface that comes into contact with a cutter head (not shown), the rear surface 24 is a rear surface in the traveling direction of the cutter bit 1, and the bottom surface 23 and the rear surface 24 of the base material 2 are perpendicular to each other. Crosses. The shape of the base material 2 is not limited.

A chipped portion 25 that accommodates the blade material 3 is formed at a corner portion of the tip of the base material 2 (a corner portion where the back surface 21 and the front surface 22 intersect).
The defect portion 25 is formed in an L shape in sectional view by the first plane 26 and the second plane 27. The first plane 26 is parallel to the front surface 22, and the second plane 27 intersects the first plane 26 at a right angle. In addition, the cross-sectional shape of the defect | deletion part 25 is not limited.

As shown in FIG. 1A, the blade material 3 is arranged in parallel along the direction in which the seven hard tips 4 and 5 intersect the rotation direction of the base material 2 (the left-right direction in FIG. 1A). It is configured by (lamination). That is, a step (unevenness) is formed on the upper surface of the blade 3.
The number of hard chips 4 and 5 is not limited, and may be set as appropriate according to the dimensions of the hard chips 4 and 5 and the dimensions of the base material 2.

The blade material 3 is fixed to the defect portion 25 by silver brazing at a brazing temperature of about 700 ° C.
The brazing material for fixing the blade member 3 is not limited to silver brazing, and for example, brass brazing may be used.

In the present embodiment, shock-resistant carbide tips are used as the hard tips 4 and 5 constituting the blade material 3. The blade material 3 is brazed to the chipped portion 25 of the base material 2 in a state where the hard chips 4 and 5 are fixed to each other by brass brazing at a brazing temperature of about 900 ° C. In the present embodiment, a buffer layer (not shown) is provided between the hard chips 4 and 5 so that an impact does not propagate between the hard chips 4 and 5. In addition, what is necessary is just to provide a buffer layer as needed.
The brazing material for fixing the hard chips 4 and 5 to each other is not limited to brass brazing, and may be silver brazing, for example.

The blade member 3 is configured by alternately arranging a high tip 4 with a high blade tip position and a low tip 5 with a lower blade tip position than the high tip 4.
In this embodiment, the high chip 4 and the low chip 5 are combined so that both ends become the high chip 4, but both ends become the low chip 5 as shown in FIGS. 2 (a) and (b). You may combine.

The high chip 4 has a width (length in the left-right direction) of 5 mm or more and 50 mm or less.
The high chip 4 has a height protruding from the back surface 21 of the base material 2 toward the ground. Further, the cutting edge of the high tip 4 protrudes to the ground (upper side) than the cutting edge of the low tip 5.
The high tip 4 is inclined so that the upper surface (side surface of natural ground) is separated from the bottom surface (lower surface) 23 as the tip side is directed toward the tip side, so that the cutting edge has an acute angle.

  In the present embodiment, the upper surface of the high chip 4 is parallel to the back surface 21 of the base material 2, but the inclination angle of the upper surface of the high chip 4 is not limited. For example, as shown in FIGS. 2 (a) and 2 (b), the cutting edge of the high tip 4 protrudes above the extension line of the back surface 21 of the base material 2, and the rear end of the top surface of the high tip 4 is the base material 2. You may make it correspond with the front-end | tip (rear end of the upper surface of the low chip | tip 3) of the back surface 21 of this.

The low tip 5 is inclined so that the upper surface (side surface of natural ground) is separated from the bottom surface (lower surface) 23 toward the tip side, so that the cutting edge has an acute angle.
In the present embodiment, the upper surface of the low chip 5 is parallel to the rear surface 21 of the base material 2. Further, the height of the rear end of the upper surface of the low chip 5 coincides with the tip of the back surface 21 of the base material 2. That is, the upper surface of the low chip 5 does not protrude from the back surface 21 and coincides with the extended surface of the back surface 21 of the base material 2.

  The height of the low tip 5 need only be lower than the height of the high tip 4, and need not be flush with the back surface 21 of the base material 2. For example, the cutting edge of the low tip 5 may protrude to the natural mountain side (upper side) from the extension line on the back surface of the base material 2.

The low chip 5 has the same width as the high chip 4. Note that the width of the low chip 5 is not necessarily the same as that of the high chip 4.
In this embodiment, the high chip 4 and the low chip 5 are used having the same strength, but the high chip 4 and the low chip 5 do not necessarily have the same strength. The strength may be higher than the other.

In the front portion of the back surface 21 of the base material 2 (immediately after the blade material 3), a built-up portion 6 is formed. The build-up part 6 is thickening the base material 2 by welding a hard metal layer to the back surface 21. The base material 2 has improved wear resistance on the natural ground side due to the build-up portion 6.
In addition, the formation method of the build-up part 6 is not limited, For example, what is necessary is just to form by welding a metal plate. Moreover, the build-up part 6 may be formed as needed and may be omitted.

  A built-up portion 6 is also formed at the upper portion of the front surface 22 of the base material 2 (just below the blade material 3). The method for forming the build-up portion 6 on the front surface 22 is the same as that for the build-up portion 6 on the back surface 21.

  When the gravel layer is excavated using the cutter bit 1, the gravel R intermittently contacts the blade 3 as shown in FIG. At this time, the gravel 3 is more likely to come into contact with the high tip 4 where the cutting edge projects than the low tip 5.

  As shown in FIG. 3 (b), when a crack C occurs in the high chip 4 due to contact with the gravel R, as the excavation progresses, the crack C progresses higher as shown in FIG. 4 (a). Chip 4 is chipped.

  Since the high chip 4a in which chipping has occurred and the adjacent low chips 5 and 5 are separate members, even if chipping of the high chip 4a progresses, chipping or cracking in the adjacent low chips 5 and 5 occurs. Will not occur.

Therefore, even if the chip of the high tip 4a progresses with the progress of excavation, the progress of the chip when the height becomes equal to or less than that of the adjacent low chips 5, 5 as shown in FIG. 4B. Stops.
Therefore, the excavation of the natural ground can be continued with the other healthy hard chips 4 and 5.

As mentioned above, according to the cutter bit 1 of this embodiment, even if it is a case where a crack and a chip | tip arise in a part of blade material 3 by contact with the gravel R, the fall of cutting ability can be suppressed.
That is, even when a crack or chip occurs in the cutting edge of the high tip 4 due to contact with the gravel R, the progress of the crack or chip settles in the vicinity of the position of the cutting edge of the low tip 5, so that the high chip 4 itself falls off. Can be suppressed.

  Further, since the blade material 3 is divided into a plurality of hard tips 4 and 5, even if some of the hard tips 4 and 5 (high tips 4) are cracked or chipped, other hard tips 4 and 5 are used. The blade material 3 itself does not fall off.

  Further, since the widths of the high chip 4 and the low chip 5 are 5 mm or more and 50 mm or less, a large number of hard chips 4 and 5 can be disposed on the base material 2. Even if one of them is cracked or chipped, the influence on the cutting ability is small.

  Further, since the brazing area of the hard chips 4 and 5 is increased by reducing the chip width of the hard chips 4 and 5, the binding force of the hard chips 4 and 5 is increased and the hard chips 4 and 5 are dropped off. Is prevented.

Materials having different brazing temperatures for the brazing material used for brazing the hard tips 4 and 5 when forming the blade material 3 and the brazing material used for fixing the blade material 3 to the base material 2 Therefore, the blade material 3 in which the hard tips 4 and 5 are brazed in advance is prevented from being separated by the brazing temperature when being fixed to the base material 2.
In addition, the manufacturing method of the cutter bit 1 is not limited.

  Since the build-up portion 6 formed around the blade member 3 prevents only the base material 2 made of a material softer than the blade material 3 from being worn ahead, the blade material 3 is used as the base material. 2 is prevented from falling off.

  The embodiment according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.

The cutter bit 1 of the present invention is a shield machine, a propulsion machine, a TBM used for tunnel construction, an excavator used for construction of excavation holes, excavation grooves, etc. associated with construction of on-site piles and construction of underground continuous walls. Etc., can be applied to all kinds of excavators.
The cutter bit 1 can be applied to all kinds of cutter bits such as a preceding bit, a main bit, and a double-headed bit.

The blade material 3 may be arranged in a plurality of rows in the front-rear direction.
The blade 3 may have a step on the front side in addition to the top side.

1 Cutter bit 2 Base material 3 Cutting material 4 High chip (hard chip)
5 Low chip (hard chip)
6 Overlay portion C Crack R Gravel

Claims (3)

A cutter bit comprising a base material, and a blade material fixed to the base material,
The blade material is composed of a high tip and a low tip whose blade tip position is lower than the blade tip position of the high tip,
The cutter bit according to claim 1, wherein the high chip and the low chip are alternately arranged along a direction intersecting a rotation direction of the base material.   The cutter bit according to claim 1, wherein a width of the high chip and the low chip is 5 mm or more and 50 mm or less.   The cutter bit according to claim 1 or 2, wherein heights of rear ends in the rotation direction of the base material of the high chip and the low chip are equal.

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