JP2002322893A - Bidirectional excavating bit and casing cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bidirectional excavating bit and a casing cutter suitable for excavating the obstruction ground including reinforcements. SOLUTION: This bidirectional excavating bit 1 for presenting a rectangular solid block is composed of an excavating blade member 3 existing in a central part, and a pair of guide members 4 positioned on both sides of this excavating blade member 4. The guide members 3 are composed of a pair of guide pieces 5, and restrain spring back of the reinforcements by an inclined guide surface 6. The excavating blade member 3 finely cuts the reinforcements by a bar- shaped tip 9. This bidirectional excavating bit 1 is arranged and fixed on an annular end surface 22 of a cylindrical casing body 21 to constitute the casing cutter 20. These excavating blade member 3 and guide members 4 can be directly installed in the casing body 31 to thereby constitute the casing cutter 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional drill bit and a casing cutter, and more particularly to a drill bit for digging obstacle ground such as reinforced concrete.

[0002]

2. Description of the Related Art Conventionally, as bits or casing cutters for excavating obstacle ground, for example, as shown in Japanese Patent Publication No. 7-91932, the tips of a large number of carbide tips implanted at an annular end form a wave. An illustrated casing head is disclosed.

[0003] As disclosed in Japanese Utility Model Publication No. Hei 7-26477, a cut surface is formed by welding a cementitious crushed material to a concave portion at the tip of a drilled tube, and the cut surface is rotated in the rotational direction. There is disclosed a drill bit or the like which is inclined toward the drill tube toward the side.

[0004]

However, in the casing head disclosed in the first gazette, it is necessary to prevent entanglement or depression due to springback of the reinforcing bar during excavation, so that the number of cemented carbide tips must be increased. In addition, even if it is torn off properly, the shape becomes irregular, so that there is a problem that the discharge of the powder is not smooth.

[0005] Further, a drill bit having a cutting surface for welding a cemented carbide crushed material disclosed in a later publication has a small inclined surface in order to maintain a small cut, but springs back. In such a state, there is a problem that the reinforcing bar cannot be cut finely, and the reinforcing bar is caught on the cut surface.

In view of the above, the present invention provides a bidirectional drill bit and a casing cutter suitable for excavating obstacle ground including a reinforcing bar.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and has an excavating blade member in which a rod-shaped chip is implanted is disposed at a central portion of a bit body having a substantially rectangular block. Moreover, an improved bidirectional drill bit is provided so that guide members are provided on both sides thereof.

That is, the guide member comprises at least a pair of guide pieces, and the guide pieces are provided on the side surface of the bit body, and each of the guide pieces has a guide surface which is inclined upward toward the excavating blade member. Things. This takes into account the effect of suppressing the springback of the rebar and preventing the shoulder of the excavation groove width from collapsing.

[0009] A plurality of rod-shaped chips made of cemented carbide are implanted in the upper surface of the excavating blade member.
Moreover, this rod-shaped tip is such that the one at the highest position is higher than the highest position of the guide member. This is in consideration of cutting the rebar finely and making excavation effective, and the bar-shaped tip is configured to perform a self-generating blade action during excavation, or the guide member is configured to be smaller than the bar-shaped tip. It is preferable to be made of a soft cemented carbide. Further, from the viewpoint of discharging the powder, it is preferable that a powder discharge groove for the excavating blade member is formed between the guide pieces.

[0010] Further, the bidirectional drill bit may be configured such that one or two or more intermediate guide pieces are provided between a pair of guide pieces provided on both side surfaces of the bit body. The upper surface portion is formed by a normal plane, but it is also possible to form a modification in which inclined surfaces are formed on both sides of the central plane. In addition, the guide member and the excavation blade member may be configured such that a portion of an adjacent portion thereof is overlapped on the basis of the excavation direction, or a configuration in which the excavation blade member is divided into a plurality of parts and configured in a staggered arrangement. These are all measures to be taken by changing the situation of the excavated object.

The present invention also provides a casing cutter in which a plurality of the excavating bits are arranged and fixed at an annular end of a cylindrical casing main body. In this case, the excavation blade member is directly attached to the cylindrical casing body so that the guide member is positioned before and after the excavation blade member with the excavation blade member at the center. May be formed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a bidirectional drill bit according to the present invention will be described below with reference to the drawings.

1 to 3 show a bidirectional drill bit 1 according to the present invention.
The bit body 2 made of steel presenting a substantially rectangular block is provided with an excavating blade member 3 at a central position and a pair of guide members 4 and 4 located on both sides thereof. The guide members 4, 4 are configured to precede the excavation blade member 3 on the basis of the excavation direction by forward and reverse rotation.

The guide members 4, 4 are constituted by including at least a pair of guide pieces 5 located on both side surfaces of the bit main body 2, and the guide pieces 5 are used to effectively suppress the reinforcing bar. A guide surface 6 that is inclined upward toward the excavating blade member 3 is formed. In this case, the guide pieces 5 are generally in a positional relationship slightly protruding from the upper surface portion 2a of the bit main body 2, and between the guide pieces 5, a powder discharge groove 7 for the excavating blade member 3 is formed. I have.

The digging blade member 3 is usually
A number of cemented carbide rod-shaped tips 9 are implanted into the mounting body 8 by press-fitting, brazing, or the like, and a part thereof projects about 0.3 to 3 mm from the upper surface 10 of the mounting body 8 to cut the reinforcing bar. Ordinary excavation can be performed. In this case, the upper surface 10 of the mounting body 8 is
A rod-shaped chip 9 having a diameter of about 3 to 5 mm is used as the rod-shaped tip 9.
However, a polygonal shape such as a triangle, a quadrangle, and a pentagon may be used, and a shape having a natural blade function of regenerating a cutting edge portion in accordance with excavation is preferable.

The production of the cutting edge member 3 constructed as described above is disclosed in a method different from the above-mentioned case, for example, in Japanese Patent Application Laid-Open Nos. 53-82601 and 54-14620. When implanting the rod-shaped tip 9 using a matrix made of a soft alloy material, or as disclosed in Japanese Patent No. 2901202, the rod-shaped tip 9 is made of cemented carbide.
Is inserted into a metal pipe, and this assembly is integrated in a brazing atmosphere.

In these cases, in the initial form of manufacture, the mounting body 8 of the digging blade member 3 and the end face of the rod-shaped tip 9 may be on the same plane. This is, after drilling,
This is because the protrusion of the rod-shaped tip 9 can be ensured by the wear of the mounting body 8.

By the way, the rod-shaped tip 9 of the excavating blade member 3
As shown in FIG. 2, the highest one of the protruding ends is higher than the highest one of the guide members 4, 4 by δ. And usually, the δ amount is 1 to 20
mm, this range is the length of the digging blade member 3,
It changes depending on the presence or absence of the inclined surface 10a.

When the mounting body 8 is formed of a matrix or a metal tube, the upper surface 10 and the rod-shaped chip 9 are usually located on the same plane, but the surface on which the rod-shaped chip 9 is located is referred to. Is set.

The guide members 4 and 4 are arranged so as to precede them in consideration of making a cut of a predetermined amount or less on the digging blade member 3. The reason for forming the surface 6 is to prevent excessive cutting when the excavating blade member 3 bites against the object to be excavated.

It is preferable that the guide members 4 and 4 be made of a cemented carbide that is softer than the rod-shaped tip 9.
This is because the wear progresses first in order to match the wear of the rod-shaped tip 9 of the excavating blade member 3.

FIG. 4 and FIG. 5 are explanatory views of a bidirectional drill bit 1 showing another embodiment, in which the same parts as those in the above-described embodiment are denoted by the same reference numerals.

The bidirectional excavating bit 1 has an upper surface 10 of the excavating blade member 3 with its center in a planar state and inclined surfaces toward the guide members 4 on both sides thereof.

FIG. 6 is a conceptual explanatory view of a bidirectional drill bit 1 showing another embodiment, in which the same parts as those in the above-described embodiment are denoted by the same reference numerals. The main difference is that an intermediate guide piece 5a is provided between the pair of guide pieces 5 in order to enhance the guiding action of the guide members 4 and 4. In this case, one intermediate guide piece 5a is shown, but if the excavation bit 1 has a large excavation width, it may be appropriately changed to include two or more intermediate guide pieces 5a.

FIGS. 7 and 8 are explanatory views of a bidirectional drill bit 1 showing still another embodiment, in which the same parts as those in the above-described embodiment are denoted by the same reference numerals.

The bidirectional drill bit 1 is formed by increasing the length of the centrally located excavating blade member 3 to increase its upper surface.
Reference numeral 10 designates a flat surface at the center and inclined surfaces on both sides, and the guide surface 6 of the guide piece 5 is a primary guide surface.
6a and the secondary guide surface 6b.

FIGS. 9 and 10 are explanatory views of a bidirectional drill bit 1 according to still another embodiment, in which the same parts as those in the above-described embodiment are denoted by the same reference numerals.

The excavating blade member 3 and the guide members 4 and 4 in the bidirectional excavating bit 1 are adjacent portions and partially overlap each other. This is because the guiding action on the excavated object and the excavating action when biting
This is to allow for a smooth transition.

FIGS. 11 to 13 are conceptual illustrations of a bidirectional drill bit 1 showing still another embodiment. The difference from the above-described embodiment is that the drill blade members 3 are arranged in a pair of staggered blade arrays. It has been done. This takes into account the digging balance of the digging blade member 3.

The embodiment shown in FIGS.
The number of the zigzag blade arrangement is increased, and emphasis is mainly placed on the digging action of the digging blade member 3.

Next, an embodiment of the casing cutter 20 of the present invention will be described with reference to the drawings.

FIG. 17 to FIG. 24 are conceptual explanatory views showing the casing cutter 20. In the casing body 21 having a cylindrical shape, the above-described bidirectional drill bit 1 is incorporated. Things.

The casing cutter 20 shown in FIGS. 17 to 20 has a mounting recess 23 formed in an annular end face 22 of a cylindrical casing main body 21. The bit body 2 of the bit 1 is fixed by, for example, welding. In this case, the bidirectional excavation bit 1 is configured such that the inner peripheral edge and the outer peripheral edge are arranged at a ratio of 1: 1 with respect to the casing main body 21. The blade and the outer peripheral blade may be configured, and when the casing diameter is large, the number of the outer peripheral blades attached may be increased due to the load of the centrifugal force.

The bidirectional drill bit 1 attached to the casing body 21 has the bit body 2 having the guide member 4 having the inclined guide surface 6 and the drilling blade member having the rod-shaped tip 9 as described above. The bar-shaped tip 9 is provided at the highest position among the bar-shaped tips 9 in preparation for the shredding of the reinforcing bar, and is higher than the highest position of the guide members 4 and 4 by δ. In the embodiment shown in FIGS. 17 and 19, the length of the guide piece 5 is shorter than that of the guide piece 5 on the outer circumferential side in order to facilitate the discharge of powder from the guide piece 5 on the inner circumferential side.

Further, the casing cutter 20 shown in FIGS. 21 and 22 has the drill bit 1 shown in FIGS. 7 and 8 attached to the recess 23 of the casing body 21.
24 and the casing cutter 20 shown in FIGS. 9 and 1
In this figure, a bidirectional drill bit 1 shown in FIG.

Further, the casing cutter 30 shown in FIGS. 25 to 28 includes a digging blade member 3 and a pair of guide members 4, 4.
Are directly attached to the annular end face 32 of the casing body 31.

Therefore, the powder discharge groove 7 for the excavating blade member 3 is formed on the casing body 31 side. However, from a manufacturing point of view, the pair of guide members 4 and 4 may be configured to be mounted on a mounting block (not shown), and the dust discharge groove 7 may be formed in this mounting block.

In the casing cutters 20 and 30 thus configured, when the reinforcing bar is not cut, there is no impact load due to the reinforcing bar, so that normal excavation is performed by the bar-shaped tip 9 of the excavating blade member 3.

On the other hand, when the casing cutters 20 and 30 cut the rebar, the guide members 4 and 4 preceding the excavating blade member 3 suppress the springback of the rebar by the guide surface 6 with the inclination. The rod-shaped tip 9 of the excavating blade member 3 cuts the rebar finely in a stable state.

Therefore, in the conventional cutting of only the cutting blade member 3, there is an impact due to excessive cutting generated when the reinforcing bar bites, whereas in the case of the casing cutters 20 and 30 of the present invention, such a biting occurs. Since an excessive impact is not applied at the time, vibration, stoppage of the machine, breakage of the drill bit 1 and the like are greatly reduced.

The guide pieces 5 of the guide members 4, 4 are also provided.
Are provided on the inner peripheral side and the outer peripheral side of the casing main body 1, so that when located on the groove width side, shoulder collapse of the groove width is prevented, and the normal excavation action by the rod-shaped tip 9 is performed. In this case, if the rod-shaped tip 9 is configured to perform a self-generated blade action, effective excavation can be constantly maintained.

The casing cutters 20 and 30 of the present invention
Since the projecting amount δ is configured between the rod-shaped tip 9 of the excavating blade member 3 and the pair of guide members 4, at the time of the initial excavation, the rod-shaped tip 9 was broken until it reached an appropriate state. After this, a uniform excavation state was obtained with uniform wear with a constant protrusion amount. As a result, the excavation resistance was constant and the service life was improved.

[0043]

According to the present invention, as described above, the bit main body 2 is provided with the guide members 4 and 4 having the guide surface 6 preceding the excavating blade member 3 in which the rod-shaped tip 9 is implanted. And provided a bidirectional drill bit 1
The present invention also provides casing cutters 20, 30 constituted by using the bidirectional drill bit 1.

Therefore, according to the present invention, the guide surface 6 of the guide member 4 can suppress the entanglement of the reinforcing bar due to the spring back, and the rod-shaped tip 9 of the excavating blade member 3 can be prevented.
Accordingly, since the rebar can be cut finely, the excavation can be performed even in a state where the machine and the excavated object are easily bent.

Further, in the present invention, the rod-shaped tip 9 is configured such that the highest one of them is higher than the highest position of the guide members 4, 4 by an amount δ. At the time of excavation, the rod-shaped tip 9 breaks until it reaches an appropriate state, but thereafter wears uniformly with a constant protrusion amount, so that there is an advantage that the excavation resistance is stabilized and the life is improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a bidirectional drill bit according to the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a side view of FIG. 1;

FIG. 4 is a plan view showing another embodiment of the bidirectional drill bit of the present invention.

FIG. 5 is a front view of FIG. 4;

FIG. 6 is a plan view showing another embodiment of the bidirectional drill bit of the present invention.

FIG. 7 is a plan view showing still another embodiment of the bidirectional drill bit of the present invention.

FIG. 8 is a front view of FIG. 7;

FIG. 9 is a plan view showing still another embodiment of the bidirectional drill bit of the present invention.

FIG. 10 is a front view of FIG. 9;

FIG. 11 is a plan view showing another embodiment of the bidirectional drill bit of the present invention.

FIG. 12 is a front view corresponding to FIG. 11;

FIG. 13 is a side view of FIG. 11;

FIG. 14 is a plan view showing another embodiment of the bidirectional drill bit of the present invention.

FIG. 15 is a front view of FIG. 14;

16 is a side view of FIG.

FIG. 17 is a partial plan view showing one embodiment of the casing cutter of the present invention.

FIG. 18 is a partial front view of FIG. 17;

FIG. 19 is a partially enlarged plan view of FIG. 17;

20 is a partially enlarged front view of FIG. 18.

FIG. 21 is a partially enlarged plan view showing another embodiment of the casing cutter of the present invention.

22 is a partially enlarged front view of FIG. 21.

FIG. 23 is a partially enlarged plan view showing another embodiment of the casing cutter of the present invention.

24 is a partially enlarged front view of FIG. 23.

FIG. 25 is a partially enlarged plan view showing another embodiment of the casing cutter of the present invention.

26 is a partially enlarged front view of FIG. 25.

FIG. 27 is a partially enlarged plan view showing another embodiment of the casing cutter of the present invention.

28 is a partially enlarged front view of FIG. 27.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling bit 2 Bit main body 2a Upper surface 3 Excavating blade member 4 Guide member 5 Guide piece 5a Intermediate guide piece 6 Guide surface 6a Primary guide surface 6b Secondary guide surface 7 Powder discharge groove 8 Mounting body 9 Rod tip 10 Upper surface 20 Casing Cutter 21 Casing body 22 Annular end face 23 Recess 30 Casing cutter 31 Casing body 32 Annular end face

Claims (10)

[Claims] 1. A bidirectional drilling bit wherein a drilling blade member is disposed at a central portion of a bit main body having a substantially rectangular block, and guide members are provided on both sides thereof. Consists of at least a pair of guide pieces provided on the side surface side of the bit body, and furthermore, the guide pieces are formed with guide surfaces inclined upward toward the excavation blade member, respectively. The excavation blade member has a plurality of rod-shaped tips made of cemented carbide implanted in the upper surface portion thereof, and the rod-shaped tip at the highest position thereof is higher than the highest position of the guide member. A bidirectional drill bit characterized by being in a high position. 2. The bidirectional excavation bit according to claim 1, wherein the bar-shaped tip is configured to perform a self-generating blade action during excavation. 3. The bidirectional drill bit according to claim 1, wherein the guide member is made of a cemented carbide that is softer than a rod-like tip. 4. The bidirectional drilling bit according to claim 1, wherein a powder discharge groove for the drilling blade member is formed between the guide pieces. 5. The bidirectional drill bit according to claim 1, wherein one or two or more intermediate guide pieces are provided between a pair of guide pieces provided on both side surfaces of the bit body. . 6. The bidirectional drilling bit according to claim 1, wherein an upper surface portion of the drilling blade member is formed by a plane, or an inclined surface is formed on both sides of a central plane. 7. The bidirectional excavation bit according to claim 1, wherein the guide member and the excavation blade member partially overlap with each other on the basis of the excavation direction. 8. The bidirectional excavation bit according to claim 1, wherein the excavation blade member is divided into a plurality of parts and forms a staggered arrangement. 9. A casing cutter, wherein a plurality of drill bits are arranged and fixed at an annular end of a cylindrical casing body. 10. A casing body having a cylindrical shape is directly attached in a set such that the guide member is positioned before and after the excavation blade member in the center, and furthermore, an excavation is provided between the guide pieces. A casing cutter, wherein a powder discharge groove for the blade member is formed.