JP2005096022A - Core drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core drill capable of considerably reducing noises in drilling. <P>SOLUTION: This core drill with a diamond tip or a superalloy joined to the tip of a cylindrical shank is characterized in that resin is attached to the outer periphery of the shank. A JIS hardness of the resin is 70 or more, and the resin is selected out of tatrafluoroethylene-propylene resin, polytetrafluoroethylene resin, nylon, acetal resin, polycarbonate, urethane resin, epoxy resin, and the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a core drill for making a hole in a fume tube or a reinforced concrete wall.

Conventionally, when making a hole for connecting a branch pipe to the side wall of a fume pipe (concrete pipe made of iron strip) or a hole for inserting a pipe pipe into a reinforced concrete wall, a cylindrical shape is used. A core drill formed by joining a diamond tip or a superalloy to the tip of the shank is used.
This core drill has a shape in which a plurality of diamond chips (sintered diamond mixed powder) or superalloys are joined at a predetermined pitch to the end edge of a cylindrical metal shank.
When drilling holes in the fume pipe side wall or concrete wall using this core drill, connect the rear end of the shank to the output shaft of the electric motor via a shaft coupling, and use the electric motor to move the shank around its axis. It is rotating. Then, the diamond tip etc. at the tip of the shank is pressed against the side wall of the fume pipe or the reinforced concrete wall, and the hole for connecting the branch pipe is made in the side wall of the fume pipe with the diamond tip etc., or the hole for inserting the pipe pipe is made in the reinforced concrete wall. Yes.

However, when the core drill is used to make holes in the fume tube side wall or reinforced concrete wall as described above, the rotating shank generates resonance noise or the diamond tip or the like cutting the fume tube side wall or reinforced concrete wall. The shanks joined together generated significant vibration and noise. In particular, when it was constructed in a housing complex such as a condominium, it caused noise pollution to the residents, which was regarded as a problem.
In order to solve this problem, in Japanese Patent Application Laid-Open No. 7-62966, in a core drill formed by joining a diamond tip to a cylindrical shank tip, a flexible material for noise reduction is wound around the outside of the shank. A core drill characterized by being deposited is disclosed. However, such soft materials are only described as rubber, synthetic resin, leather and caulking material. If the flexible material is a tough member that is not easily crushed even if it touches the cut part of the fume tube side wall or concrete wall, the flexible material is not shaved on the outside or inside of the shank. Although it is described that it may be attached to the peripheral wall so as to protrude outward or inward of the shank, it is not disclosed at all what kind of tough member is used.
JP-A-7-62966

  When drilling with a bit, the shank rotates at a very high speed. Therefore, when the outside of the shank is attached with a synthetic resin or the like, the synthetic resin is required to have high heat resistance. The present inventor has repeatedly studied this point, and found that heat resistance of about 180 ° C. is required even when drilling a wall of a normal house and about 240 ° C. when drilling in reinforced concrete. Furthermore, since it rotates at such a high speed, a large wear resistance is also required. Moreover, in order to exhibit high soundproof performance, it is also necessary to have a certain degree of flexibility.

The present inventor has conducted extensive studies to find a material that satisfies such a plurality of performances and is easy to construct, and has completed the present invention.
An object of this invention is to provide the core drill which can reduce the noise at the time of drilling significantly.

  The present invention provides a core drill in which a diamond tip or a superalloy is bonded to a cylindrical shank tip, wherein a resin is deposited on the outer periphery of the shank, and the JIS A hardness of the resin Is a vulcanized natural rubber, vulcanized isoprene rubber, styrene-butadiene resin, acrylonitrile-butadiene resin, hydrogenated nitrilo resin, carboxylated nitrilo resin, urethane resin, silicone resin, polyvinylidene fluoride, Selected from the group consisting of a core drill, which is a resin selected from the group consisting of tetrafluoroethylene-propylene resin, polytetrafluoroethylene resin, nylon, acetal resin, polyvinyl chloride, polycarbonate, ABS resin, epoxy resin, and polystyrene. Providing a core drill That.

In the core drill of the present invention, since the resin is deposited around the core drill that rotates at high speed, the resin requires not only hardness and toughness but also wear resistance, heat resistance, flexibility, preferable dynamic friction resistance, and the like. . From the above viewpoint, the present invention is characterized in that an appropriate resin is selected.
The JIS A hardness of the resin used in the present invention is 70 or more, preferably 80 or more, more preferably 85 or more, and most preferably 90 or more.
The resin used more preferably in the present invention is a resin selected from the group consisting of tetrafluoroethylene-propylene resin, polytetrafluoroethylene resin, nylon, acetal resin, polycarbonate, urethane resin, and epoxy resin.
Typically, the resin desirably has a tensile strength of 200 kg / cm ² or more, a 100% modulus of 60 or more, a 300% modulus of 100 or more, an elongation of 500% or more, and a tear strength of 50 kg / cm or more.

  The resin most preferably used in the present invention is a urethane resin. Of these, polyether urethane elastomers, particularly polyether urethane elastomers using polypropylene glycol are preferred. The urethane elastomer is mixed with a curing agent such as amine and / or alcohol and cured. The mixing ratio of the elastomer and the curing agent can be appropriately determined by those skilled in the art.

In the present invention, the resin is preferably applied with a thickness of 1 to 5 mm, preferably with a thickness of 2 to 4 mm.
In this specification, the term “adhesion” refers to covering the shank portion with resin.
If the resin is too thick, the perforation performance deteriorates, and if it is too thin, a sufficient soundproofing effect cannot be obtained.
The shank portion of the core drill of the present invention may have the same outer diameter in the length direction or may have a larger outer diameter at both ends in the length direction. Preferably, the outer diameter of both ends in the length direction of the core drill is increased, and a resin layer is provided in a portion of the central portion having a smaller outer diameter.
Preferably, about half or more, more preferably about 3/4 or more of the shank portion of the core drill is deposited with a resin layer.

  In the core drill of the present invention, noise during drilling is greatly reduced. It can be easily reused and contributes to the protection of the global environment.

FIG. 1 shows an example of a core drill 10 of the present invention.
A diamond tip 12 is joined to the core drill. Resin is applied to the shank portion 14 of the core drill. Both side portions 16 of the portion to which the resin is applied have an outer diameter larger than or equal to that of the portion to which the resin is applied. Therefore, an excessive load is prevented from being applied to the resin portion, and the life of the resin portion is increased.

The core drill of the present invention can be obtained by spraying or coating a resin or the like on the surface of the core drill. Conditions such as a preferred temperature vary depending on the resin used, and these are matters that can be easily determined by those skilled in the art.
For example, when a urethane resin is used, the urethane elastomer is preheated, defoamed, and the molten curing agent are mixed and stirred, and then cast and cured to form a resin coating layer on the core drill surface. Can be formed. When casting, form a mold by combining the core drill to be attached and a tube slightly thicker than its outer diameter, and inject a mixture of urethane elastomer and curing agent into the gap, then cure and release The aging process is performed. Thereafter, the urethane resin layer can be shaved to a predetermined thickness.
In the core drill of the present invention, when the rubber or resin layer deteriorates, breaks or wears down by use, the rubber or resin layer may be removed and reused by spraying or coating the resin again. it can.
Since the method for forming the urethane resin adherent layer is simple and the processing cost is low, it is an excellent method for processing a core drill to be used repeatedly.

Example A mixture of a polyether-based urethane elastomer using polypropylene glycol and an amine curing agent on the surface of the core drill was applied with a thickness of 4 mm.
When this was used to make a hole in a concrete wall, the noise was greatly reduced.

FIG. 1 is a diagram showing an example of a core drill according to the present invention.

Explanation of symbols

10: Core drill 12: Diamond tip 14: Shank portion having a resin deposition layer 16: Both side portions of the shank portion having a resin deposition layer

Claims (3)

A core drill formed by joining a diamond tip or a superalloy to a tip of a cylindrical shank, wherein the resin is deposited on the outer periphery of the shank, wherein the resin has a JIS A hardness of 70 or more. Yes, this resin is vulcanized natural rubber, vulcanized isoprene rubber, styrene-butadiene resin, acrylonitrile-butadiene resin, hydrogenated nitrilo resin, carboxylated nitrilo resin, urethane resin, silicone resin, polyvinylidene fluoride, tetrafluoroethylene -Core drill, which is a resin selected from the group consisting of propylene resin, polytetrafluoroethylene resin, nylon, acetal resin, polyvinyl chloride, polycarbonate, ABS resin, epoxy resin, and polystyrene. The core drill according to claim 1, wherein the resin is a resin selected from the group consisting of tetrafluoroethylene-propylene resin, polytetrafluoroethylene resin, nylon, acetal resin, polycarbonate, urethane resin, and epoxy resin. The core drill according to claim 1 or 2, wherein the resin is applied in a thickness of 1 to 5 mm.

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