JP2004181589A - Bit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bit in which there is little fear of a failure, such as a chip of a diamond tip joined to the tip of a bit body, and which is especially suitable for the drilling of an iron plate. <P>SOLUTION: The bit 1 is mainly comprised of a cylindrical bit body 3, a plurality of tips 2 joined to the tip of the bit body 3 in an alienated state with keeping a predetermined clearance C, and a substantially cylindrical coupled transmission portion 4 which is provided on the rear end of the bit body 3 and coupled to a core drill for making the bit 1 perform high-speed rotation, and of which the diameter is reduced against the bit radius of the bit body 3. The tip 2 is joined so that the clearance C with the adjacent tip 2 becomes not more than 2.0 mm. Further, on the external side 5 of the tip 2, one groove portion 7a is provided, on the internal side, two groove portions are provided, and wear at the drilling can be equalized. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bit, and more particularly to a bit used for drilling concrete and an iron plate at a construction site or the like.
[0002]
[Prior art]
Conventionally, at the work site of a building or the like, a concrete floor or wall surface is perforated, and a pipe hole for a pipe for introducing electric wiring, water and sewage pipes, gas pipes and the like into a room is provided adjacently. The rooms and the upper and lower floors may be connected. At this time, a bit having a substantially cylindrical shape is often used as a tool for boring a concrete or the like. In such a bit, a diamond chip (also referred to as a cutting chip or the like) in which ultra-hard artificial diamond particles (diamond grindstone) are fixed to at least the surface by sintering is joined to the bit tip by brazing or the like, and the bit is formed at high speed. In this method, concrete to be drilled is cut with a diamond tip at the tip (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 6-1769
[Problems to be solved by the invention]
Here, as described above, the bit has a structure in which the diamond bit is joined to the tip of the cylindrical bit body by brazing or the like, and the interval (clearance) between the diamond chips is generally relatively large. There were many things being done. Such a clearance is provided in order to avoid a state in which, during drilling of concrete or the like, cut concrete powder or debris is filled between diamond chips or the like, causing clogging and preventing stable drilling work. Had been. More specifically, the concrete powder cut by the rotated diamond chips could be discharged to the inside or outside of the bit body through a clearance, for example.
[0005]
However, as the concrete to be perforated, reinforced concrete or the like in which a reinforcing bar or the like is buried therein is often used in order to further reinforce the concrete strength. Further, under the floor of the building, a corrugated iron plate was sometimes laid as a keystone. Therefore, when drilling such a reinforced concrete or keystone using the above-mentioned bit, it was necessary to drill the steel bar or the keystone portion of the diamond tip at the tip of the bit together with the concrete.
[0006]
Here, iron material has a higher hardness than concrete, and it requires a lot of force for cutting work and takes much time to perform work, which makes the work more difficult than when drilling concrete. In some cases, a large load is applied to the core drill motor that drives the bit to rotate.
[0007]
In addition, because the clearance between adjacent diamond chips is large, it is highly possible that a part of the iron plate is inserted into the clearance, especially when drilling into a corrugated iron plate such as a keystone, and during high-speed rotation. Diamond chips may get caught. As a result, the high-speed rotational movement of the bit was hindered, and stable drilling could not be performed. Further, in this case, since a large load is applied to the diamond chip, the diamond chip brazed to and joined to the bit main body may come off from the bit main body and be scattered or chipped. For this reason, many people who perform drilling work desire a bit that can easily perform drilling on reinforced concrete, iron plate, or the like.
[0008]
In view of the above circumstances, it is an object of the present invention to provide a bit which is less likely to be broken such as a chip of a diamond chip joined to the tip of a bit body and is particularly suitable for drilling an iron plate.
[0009]
[Means for Solving the Problems]
In order to solve the above problem, in the bit according to the first aspect of the present invention, a plurality of diamond tips are joined to the tip of a cylindrical bit body while maintaining a predetermined clearance along a circumferential direction. In the bit, the clearance of the diamond tip is in a range of 0.5 mm or more and 3.0 mm or less.
[0010]
Therefore, according to the bit of the first aspect of the present invention, each diamond chip has a clearance between adjacent diamond chips within a range of 0.5 mm or more and 3.0 mm or less, more preferably 1.0 mm or more and 2.0 mm or less. Chips are joined. This makes it possible to reduce the possibility that a part of a ferrous material such as a reinforcing bar or an iron plate is inserted into the clearance when drilling a hole in a pierced material such as reinforced concrete by rotating the bit at a high speed. Less snagging. Thus, a stable drilling operation can be performed without hindering the high-speed rotation of the bit. In addition, since the load on the diamond chip given by the iron material being hooked on the bit is reduced, there is less danger of the bonded diamond chip being broken or chipped.
[0011]
If the clearance of the diamond tip is smaller than 0.5 mm, chips (or chips) of concrete or iron material cut by the bit may be clogged by the clearance. As a result, chips and the like cannot be appropriately discharged to the inside or outside of the bit main body, and it may be difficult to perform the drilling operation continuously and under stable conditions. On the other hand, if the clearance is wider than 3.0 mm, there is a high possibility that the above-described rebar or the like is inserted into the clearance, hindering the movement of the bit rotating at high speed, and increasing the probability of breaking the diamond tip. Become. The clearance is more preferably set in a range of 1.0 mm or more and 2.0 mm or less. By setting the clearance in this range, the above-described disadvantages in a case where the clearance is narrow and a case in which the clearance is wide are solved. Can do it.
[0012]
The bit according to the invention of claim 2 is the bit according to claim 1, wherein the clearance has a recess formed in at least one of an outer surface and an inner surface of the diamond tip.
[0013]
Therefore, according to the bit of the invention of claim 2, in addition to the function of the bit of the invention of claim 1, a concave portion is formed on the outer surface and the inner surface of the diamond tip. This makes it possible to average the wear of the diamond tip when drilling in concrete or the like.
[0014]
The bit according to the invention of claim 3 is the bit according to claim 1 or 2, wherein the clearance is formed such that the inner surface side is narrower than the outer surface side of the diamond tip. .
[0015]
Therefore, according to the bit of the third aspect of the present invention, in addition to the operation of the bit of the first or second aspect, the clearance of the diamond tip joined to the bit body is reduced by the outer surface and the inner surface of the diamond tip. And the inner surface is formed to be narrower than the outer surface. Here, as described above, if the clearance between the adjacent diamond chips is set too small during drilling with the bit, chips tend to be caught in the clearance. At this time, if the clearance between the inner surface and the outer surface of the diamond chip is set to the same width, chips generated at the time of drilling are not easily discharged to the outside or the inside of the bit body, and are clogged by the clearance. Tends to occur.
[0016]
Therefore, if the diamond chips are joined with the outer surface having a larger clearance than the inner surface, the centrifugal force generated by the high-speed rotation of the bit is provided by providing the clearance with the diameter increasing in the circumferential direction. The chips can be discharged to the outside of the bit body by utilizing the above. As a result, it is possible to perform stable drilling without causing clogging of the clearance between the diamond chips with cutting chips.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, bit 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing the configuration of the bit 1 of the present embodiment, FIG. 2 is a plan view showing the configuration of the bit 1, and FIG. 3 is an enlarged plan view showing the main configuration of the bit 1.
[0018]
As shown in FIGS. 1 to 3, the bit 1 according to the present embodiment includes a cylindrical bit body 3 formed of a metal material such as SK steel, and a predetermined position along the circumferential direction at the tip of the bit body 3. A plurality of diamond tips 2 (hereinafter, simply referred to as “tips 2”) joined by brazing and separated from each other while maintaining the clearance C, and provided at the rear end of the bit body 3, to rotate the bit 1 at a high speed. And a connection transmission unit 4 that is connected to a core drill (not shown) that generates a driving force for transmitting the rotation driving force from the core drill. Here, the connection transmitting portion 4 is formed to be smaller in diameter than the bit outer diameter R1 of the bit body 3.
[0019]
Further, as shown in FIG. 3, the tip 2 joined to the tip of the bit main body 3 has a plate shape bent so as to substantially match the curvature of the bit outer diameter R1, and has a clearance between the tips 2 adjacent to each other. It is joined so that C is 2.0 mm or less.
[0020]
As shown in FIGS. 2 and 3, the outer surface 5 of each chip 2 is provided with one concave groove 7a that divides the outer surface 5 into substantially the same width. The inner side surface 6 is provided with two concave grooves 7b that divide the inner side surface 6 into substantially the same width. Here, the grooves 7a and 7b correspond to concave portions in the present invention. Further, the thickness of the tip 2 is formed slightly larger than the thickness of the cylindrical bit body 3. On the surface of the chip 2, ultra-hard diamond grindstone particles are fixed by sintering. Thereby, when the bit rotated by the core drill is brought into contact with the concrete or the like to be drilled, the abutting portion is cut by the diamond whetstone grains, and a hole having a size corresponding to the bit outer diameter R1 can be drilled. . In the perforation process, there are two processing methods, a "wet type" for supplying water or the like and cooling so that the perforated portion does not reach a high temperature, and a "dry type" not using water or the like. 1 can be applied to any of them.
[0021]
Further, in a general drilling operation, a particle diameter and a fixing density of diamond grinding stones used for the chip 2 are appropriately selected according to a difference in friction coefficient of a material (concrete or iron plate) of a material to be drilled. ing. That is, in the case of a concrete material having a relatively large friction coefficient, a diamond grindstone having a coarse particle diameter is used, while in the case of a metal material such as iron having a relatively small friction coefficient, a material having a small particle diameter is used. There are many. Therefore, the diameter D of the diamond grindstone used for the above-mentioned chip 2 is appropriately selected from those having a particle diameter and a fixed density that can be respectively used for concrete or iron plate. Intermediate particle sizes and fixation densities can be selected. Note that breakage such as chipping of the chip 2 described later easily occurs when a metal material such as an iron plate is drilled, and therefore, it is preferable to select a material that is particularly suitable for an iron plate or the like.
[0022]
Next, an example of a method of using bit 1 of the present embodiment will be described. First, the transmission connection portion 4 is connected to a connection portion (not shown) of the core drill so that the rotational driving force from the core drill can be transmitted. This allows the bit 1 to cooperate with the rotation of the core drill and rotate at high speed along the axis of rotation.
[0023]
Thereafter, the bit 1 rotated at a high speed is brought close to concrete or the like, and the tip 2 joined to the tip of the bit 1 is brought into contact with the surface of the portion to be drilled. As a result, the concrete is gradually cut off as chips (or chips) from the portion where the chip 2 comes into contact, and a hole corresponding to the bit outer diameter R1 of the bit 1 can be formed. The generated chips are discharged to the outside of the bit 1 or the like by centrifugal force or the like, so that it is possible to continuously perform drilling of concrete or the like.
[0024]
In the bit 1 of the present embodiment, the clearance C between the adjacent chips 2 is set to 2.0 mm or less as compared with the conventional bit. Therefore, for example, when an iron material (not shown) vertically arranged along the drilling direction and the tip 2 at the tip of the bit 1 come into contact with each other, the possibility that the iron material enters the clearance C of the tip 2 is reduced. . As a result, the tip 2 is not caught by the iron material and does not hinder the movement of the bit 1 rotating at high speed. As a result, since a large load is not applied to the chip 2, the risk of damage such as the chip 2 coming off the bit body 3 and being scattered or a part of the chip 2 being chipped is reduced.
[0025]
In addition, according to the bit 1 of the present embodiment, the wear of the chip 2 in the drilling can be averaged by the grooves 7a and 7b provided on the outer surface 5 and the inner surface 6 of the chip 2, respectively.
[0026]
As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and various improvements can be made without departing from the gist of the present invention as described below. And design changes are possible.
[0027]
That is, in the bit 1 of the present embodiment, concrete and iron materials are shown to be perforated. However, the present invention is not limited to this, and other materials such as ceramics and FRP resin are perforated. It does not matter. Furthermore, although the clearance C of the chip 2 is shown to be 2.0 mm or less, the present invention is not limited to this. If the clearance C is in the range of 0.5 mm or more and 3.0 mm or less depending on the object to be drilled. Can be set as appropriate.
[0028]
Further, in the bit 1 of the present embodiment, the clearance C of the chip 2 is shown with the outer surface 5 and the inner surface 6 formed to have the same width. However, the present invention is not limited to this. The clearance C of the inner side surface 6 may be formed differently. This facilitates the processing of the chip 2 and the joining to the bit body 3, and the chips such as concrete sandwiched in the clearance C by the perforation processing are easily discharged from the bit 1 by centrifugal force, which may cause clogging and the like. Sex is even lower.
[0029]
【The invention's effect】
As described above, the bit according to the first aspect of the invention is bonded such that the clearance of the diamond tip bonded to the bit body is in the range of 0.5 mm or less and 3.0 or more. As a result, in the bit rotating at high speed, an iron material or the like is inserted into the clearance of the diamond tip, and a stable drilling operation can be performed without obstructing the rotational movement of the bit. Furthermore, since a large load is not applied to the diamond tip, damage to the diamond tip can be reduced.
[0030]
According to the bit of the invention of claim 2, in addition to the effect of the bit of the invention of claim 1, recesses are formed on the outer surface and the inner surface of the diamond chip, and wear of the diamond chip during drilling is reduced on the outer surface and the inner surface. Can be averaged.
[0031]
According to the bit of the invention of claim 3, in addition to the effect of the bit of the invention of claim 1 or 2, the clearance between adjacent diamond chips is made different between the outer surface and the inner surface of the diamond chip, and the inner surface is formed as the outer surface. It can be formed narrower than the side surface. As a result, even if the clearance is narrower than that of the conventional bit, the clearance is less likely to be clogged with concrete chips and the like, and stable drilling can be performed.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration of a bit.
FIG. 2 is a plan view showing a configuration of a bit.
FIG. 3 is an enlarged plan view showing a configuration of a main part of a bit.
[Explanation of symbols]
1 bit 2 tips (diamond tip)
3 Bit body 5 Outer surface 6 Inner surface 7a, 7b Groove (recess)
C clearance

Claims (3)

In a bit in which a plurality of diamond tips are attached to a tip of a cylindrical bit main body while keeping a predetermined clearance along a circumferential direction and separated from each other,
The clearance of the diamond tip,
A bit characterized by being in a range of 0.5 mm or more and 3.0 mm or less. The diamond tip,
The bit according to claim 1, wherein a recess is formed in at least one of the outer side surface and the inner side surface. The clearance is
The bit according to claim 1 or 2, wherein the inner surface side is formed narrower than the outer surface side of the diamond tip.

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