JPH02279309A - Rotating drilling tool - Google Patents

Abstract

PURPOSE:To use suitably mist as cooling fluid and enhance cooling efficiency and workability by means of applying mist by communicating a fixed flow channel system with a rotating flow channel system in its flow channel shaft direction through a connecting body. CONSTITUTION:A rotating flow channel system 20 is formed by means of a hollow component 8 and a rotating drill 18. A feeding tube 24 having a through- hole 22 in the shaft direction is installed on the upper side of a tool main body 2, and with said feeding tube 24 as the end of an opening, a fixed flow channel system 26 for guiding mist M fed by an atomizer or the like from outside the tool main body 2 is formed for the purpose of cooling a cutting blade 16. The rotating flow channel system 20 and the fixed flow channel system 26 are communicated with by a connecting body 26. The mist M fed from outside the tool main body 2 by means of an atomizer or the like is, therefore, guided into the tool main body 2 by the fixed flow channel system 26, and guided directly to the opening end of the rotating flow channel system 20 by the connecting body 26. Thus, the mist can be applied properly as cooling liquid to reduce the working cost and increase workability.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rotary drilling tool used for drilling into hard non-metallic materials such as stone, concrete, porcelain tiles, glass, and ceramics.

[Conventional technology]

For drilling holes in hard non-metallic materials such as concrete and ceramics, a rotary drilling tool as shown in FIG. 4, for example, is used.

The tool body 2 has a built-in driving member driven by a power source or an air source, and the hollow member 8 is rotationally driven by this driving member.

A rotary drill 18 having an axial through hole 14 is attached to the hollow member 8, and a cutting blade 16 made of sintered diamond grains is fixed to the tip of the rotary drill. A cooling fluid spout 16 a is formed in the cutting blade 16 and communicates with the through hole 14 of the rotary drill 18 .

A rotary flow path system 20 is formed by a hollow member 8, a rotary drill 18, etc.
is formed, and a fixed flow path system 26 is formed by a supply pipe 25 and the like that guide the cooling fluid supplied from the outside of the tool body 2 into the inside. The rotating flow path system 20 and the fixed flow path system 26 communicate with each other so that they can guide fluid. The cooling fluid led from the fixed flow path system 26 passes through the rotary flow path system 20 and is ejected from the spout 16a of the cutting member 16. Then, the cooling fluid ejects! The t1 wear of the cutting blade 16 due to frictional heat is suppressed.

As mentioned above, this type of rotary drilling tool basically requires a technique for connecting the rotary flow path system and the fixed flow path system so that fluid can be guided. 90
In Publication No. 8, a spiral groove is formed on the outer peripheral surface of a hollow member to which a rotary drill is attached, and one end of the U2 groove is connected to a water supply port as a fixed flow path system of a water supply unit body surrounding the hollow member. A structure has been proposed in which the rotary drill is rounded and the other end faces a small hole formed in the radial direction of the hollow member, thereby communicating the rotary drill and the water supply port. Also, Unexamined Japanese Patent Publication No. 6
In Japanese Patent No. 0-262608, a radial path opening in the radial direction is formed in a hollow member, and the radial path is surrounded by the hollow member (a swivel space is formed in a pressure feed hose as a fixed flow path system fixed to an outer cylinder). A structure has been proposed in which the communication is made through.

In this way, the connection between a rotating flow path system and a fixed flow path system has traditionally been made by connecting a fixed flow path system to a rotating flow path system with their flow path axes perpendicular to each other, although there are structural differences. It has a structure that allows communication with direction.

[Problems to be Solved by the Invention] By the way, this type of drilling tool uses water or air as the cooling fluid, but when using water, there is a problem that the surrounding area of the work is contaminated by water suspended by chips. There is, and also,
Air has the disadvantage of low cooling efficiency. Therefore, from the viewpoint of combining the advantage of water, which has high cooling efficiency, and the advantage of air, which does not cause the problem of contamination by sewage, so-called mist, which is atomized liquid such as water, has been considered as the optimal fluid.

However, with the structure described above, the fixed flow path system is connected to the rotating flow path system under high speed rotation in a direction orthogonal to the flow path axis, so the amount of fluid supplied is small and the spiral groove or swivel The existence of a pressure space such as a space where kinetic energy decreases cannot be avoided, and therefore it is not suitable for using a mist. In other words, with this type of drilling tool, the discharge resistance is large due to the narrow discharge space of the fluid during drilling, and this also increases the internal pressure of the rotating flow path system to some extent. Most of the atomization state disappears due to stagnation, and an appropriate atomization state cannot be maintained to cool the cutting blade.

[Means to solve the problem]

In order to solve the above problems, this invention attempts to apply mist as a cooling fluid by connecting a rotating flow path system and a fixed flow path system in a structure that does not require a pressure space, and also aims to apply mist as a cooling fluid. This tool is designed to improve efficiency and workability, and is equipped with a rotary drill that has an axial through hole and a cutting blade at the tip, and a fluid supplied from outside the tool body to cool the cutting blade. A rotary drilling tool configured to communicate a fixed flow path system that guides the fluid into the inside of the tool body and a rotary flow path system including the through hole, and to eject fluid from the cutting blade through a connecting body. The fixed flow path system is configured to communicate with the rotating flow path system in the axial direction of the flow path.

Further, in the present invention, the connecting body includes a rotary member that is coaxially rotatably fixed to the communication side opening end of the rotary flow path system, and a rotary member that is fitted to the rotary member and connects the fixed flow path system and the rotary flow path. a fixed member that communicates with the passage system; a sealing member is interposed between the opposing surfaces of the rotating member and the fixed member, and a pressing load on the sealing member in the axial direction of the passageway is prevented. It is also possible to have a configuration in which a thrust bearing is interposed between the two.

[For production]

According to this invention, since the communication portion between the rotating flow path system and the fixed flow path system has a coaxial linear structure, the existence of a pressure space is avoided, and when mist is used as the cooling fluid, the fixed flow path system The mist supplied from the system is maintained in an atomized state and guided through the rotating channel system.

Further, in the present invention, the seal member prevents backflow leakage of fluid at the communication portion due to an increase in the internal pressure of the rotary flow path system, and the thrust bearing suppresses wear of the seal member due to a pressing load.

〔Example〕

FIG. 1 shows an embodiment of the invention. Note that the same parts as in the conventional example are indicated by the same reference numerals.

Inside the tool body 2, a hollow member 8 having an axial through hole 4 on the rear side and a tapered mounting hole 6 communicating with the through hole 4 on the front side is provided with a radial ball bearing 10.
It is rotatably installed via 12. A rotary drill 18 is fixed to the distal end of the hollow member 8, having a mounting hole 6, an axial through hole 14, and a cutting blade 16 made of sintered diamond grains at the distal end.

A rotary channel system 20 is formed by the hollow member 8 and the rotary drill 18. A supply pipe 24 having an axial through-hole 22 is installed on the upper side of the tool body 2. With this supply pipe 24 as an open end, a sprayer is inserted from the outside of the tool body 2 in order to cool the cutting blade 16. A fixed flow path system 26 is formed that guides the mis) M supplied by means such as the above. The rotating flow path system 20 and the fixed flow path system 26 are communicated with each other through a connecting body 26.

A gear 28 is fixed to the rear half side of the hollow member 8.

Below and parallel to the hollow member 8, a driven shaft 30 which is rotatably driven by a drive source is rotatably installed via thrust ball bearings 32,34. A gear 36 that meshes with the gear 28 of the hollow member 8 is fixed to one end of the driven shaft 30, and a gear 36 that meshes with the drive gear of the drive member is fixed to the other end.
8 is fixed. Therefore, the hollow member 8 is rotationally driven via the driven shaft 30 by the operation of the driving member.

A tapered shank portion 18a corresponding to the mounting hole 6 is formed at the rear end of the rotary drill 18, and a tapered shank portion 18a corresponding to the mounting hole 6 is formed at the end of the tapered shank portion 18a and at the back of the mounting hole 6, respectively. Male thread part 1 that screws together with direction
8b and a female threaded portion 6a are formed. As a result, the rotary drill 18 is attached to the hollow member 8 in a state where it is prevented from rotating idly and from dropping out. A sealing member 39 is installed between the tip of the tool body 2 and the tip of the hollow member 8 to prevent cutting debris from entering the inside of the tool body 2.

The connecting body 26 that connects the rotary flow path system 20 and the fixed flow path system 26 includes a convex rotating member 40 that is press-fitted into the rear end of the hollow member 8, which is the open end of the rotary flow path system 2o. It consists of a fixed member 44 which is fitted into the rotating member 4o in the axial direction of the rotating flow path system 2o and whose other end is supported by a bearing 42.

A communication hole 44a is formed in the fixed member 44 in the flow path axial direction of the rotary flow path system 2o, and a reservoir portion 4 having a large volume is formed in the fixing member 44.
A female threaded hole 44c is provided in a direction perpendicular to the communication hole 44a via 4b.
is formed. A tip 424a of the supply pipe 24 having a male thread is fixed to the female threaded hole 44c. As a result, the fixed flow path system 26 is brought into communication with the open end of the rotating flow path system 2o in the axial direction of the flow path of the rotary flow path system 20.

A thin tube 46 having a length reaching the mounting hole 6 of the hollow member 8 and having a tapered tip with a narrow end is press-fitted into the communication hole 44a of the fixing member 44. Further, in the through hole 14 of the rotary drill I8, a thin tube 50 is installed in a large diameter area on the rear end side so as to communicate with the thin tube 46 via a spacer member 4B. The tip of the thin tube 50 is also formed into a narrow tapered shape, similar to the thin tube 46. By the way, in the case of mist, water particles lose their atomized state due to the action of centrifugal force, so the supply distance in the rotation range is as short as possible.
Also, it is better to keep the diameter of the supply route to a certain extent. From this point of view, the thin tube 46 shortens the supply distance in the rotation range, and the thin tube 5o reduces the through hole 1 of the rotary drill 18.
4, the inconvenience caused by centrifugal force in a large diameter area is avoided.

A ring 52 serving as a seal member is installed between the inner opposing surfaces of the rotating member 4o and the fixed member 44 of the connecting body 26, and a thrust ball bearing 54 is installed between the outer opposing surfaces. There is. Further, the zero-rotation member 40 has an O-ring 56 installed between the opposing surfaces of the hollow member 8 and the fixed member 44.
is positioned such that its end surface slightly protrudes from the end of the hollow member 8 by the spacer member 5B. Therefore, the diameter of the O-ring 56 is larger than the diameter of the O-ring 52, resulting in a two-stage seal structure.

The O-rings 52 and 56 prevent the mist M from flowing backward, and the thrust ball bearing 54 prevents the O-rings 52 and 56 from being worn out due to a pressure load exceeding a certain level in the axial direction of the flow path. Therefore, inconveniences such as reduction in supply efficiency and short circuit due to leakage of M are avoided, and good sealing performance is maintained over a long period of time.

With the above structure, the mist M supplied from the outside of the tool body 2 by a means such as a sprayer is guided into the inside of the tool body 2 through the fixed flow path system 26, and is directed to the open end of the rotary flow path system 20 by the connecting body 26. You will be guided directly. Therefore, the atomized state is maintained well throughout the supply path, and the atomized material is guided and ejected from the cutting blade 16. As a result, when drilling into a workpiece 60 such as concrete, the cutting blade 1 has good cooling properties.
6. Wear due to frictional heat is suppressed.

In addition, in this example, the rotating member 40 of the connecting body 26 can also be integrally molded as the open end of the hollow member 8.

Next, FIGS. 2 and 3 show another embodiment of the present invention. Note that the same parts as in the above example are indicated by the same reference numerals, redundant functional explanations are omitted, and only essential parts are shown.

The supply pipe 62 forming the open end of the fixed flow path system 26 is shaped like a cane, and its vertical end 62a is connected to the tool body 2.
The horizontal end portion 62b is supported by a bearing 42. A through hole 6 is formed at right angles inside the supply pipe 62.
4 is formed, and a thin tube 46 is press-fitted into the horizontal portion of the through hole 64. Rotating flow path system 20 and fixed flow path system 2
The connecting body 66 communicates with the rotating member 68 which is press-fitted into the open end of the hollow member 8 and the fixed member 7 which is press-fitted into the horizontal open end of the supply pipe 66 and fits into the rotating member 68.
It consists of 0.

As shown in FIG. 3(A), the rotating member 68 is formed with an annular convex portion 68b connected to the press-fit hole 68a of the hollow member 8, and an annular concave portion 68c is formed between the annular convex portion 68b and the press-fit hole 68a of the hollow member 8.
An annular convex portion 60d having a small axial length is formed at the center. On the other hand, as shown in FIG. 7B, the rotating member 70 is formed with an annular recess 70b that is connected to the press-fit hole 70a for the supply pipe 62 and that fits into the annular projection 68b. An annular recess 70d having a large axial length and fitting into the annular projection 68d is formed with an annular projection 70c fitting in the annular recess 68c in between. Annular recess 68
An O-ring 72 is installed between the opposing surfaces of the annular projection 68d and the annular convex portion 70c, and a thrust ball bearing 74 is installed between the opposing surfaces of the annular convex portion 68d and the annular recess 70d. In this example, compared to the previous example, the O-ring 72 is installed at a position detoured from the open end of the hollow member 8, so that the sealing performance can be further improved.

In each of the above cases, thrust ball bearings 54 and 74 were used as the thrust bearings, but the present invention is not limited to this, and various other types such as thrust conical roller bearings and thrust cylindrical roller bearings can be used.

Further, the cooling fluid is not limited to mist, and even if air or water is used as in the conventional case, a supply state with high sealing performance can be obtained.

〔Effect of the invention〕

According to this invention, it is possible to use mist as the cooling fluid, and thereby it is possible to reduce the work cost for suppressing In wear on the cutting blade and to improve workability.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a drilling tool according to one embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of another embodiment, and FIG.
FIG. 4 is a schematic perspective view of a conventional drilling tool. 2... Tool body I6... Cutting blade, 14... Through hole 18... Rotary drill, 20... Rotating channel system 26...
・Fixed flow path system, 26.66...Connection body/10.68・
・Rotating member 44.70 ・Fixing member 52.72 ・0 ring (sealing member) 54.74 ・
...Thrust ball bearing (Thrust bearing) Patent applicant Yoshino Seiki Co., Ltd. Attorney Yoshiharu Yoshida No. 2 No. 3

Claims (2)

[Claims] (1) A fixed flow path comprising a rotary drill having an axial through hole and a cutting blade at the tip, and guiding fluid supplied from outside the tool body to the inside of the tool body in order to cool the cutting blade. and a rotary flow path system including the through hole, and in a rotary drilling tool configured to eject fluid from the cutting blade, the rotary flow path system is connected to the rotary flow path system via a connecting body in the axial direction of the flow path. A rotary drilling tool, characterized in that the fixed flow path system is connected to the fixed flow path system. (2) The rotary drilling tool according to claim 1, wherein the connecting body is connected to a rotary member that is coaxially rotatably fixed to the communication side open end of the rotary flow path system, and a rotary member that is fitted into the rotary member and fixed to the rotary member. A fixed member that communicates the flow path system with the rotating flow path system, and a seal member interposed between opposing surfaces of the rotating member and the fixed member, and a flow path to the seal member in the axial direction. A rotary drilling tool characterized by interposing a thrust bearing in a state that prevents a pressing load.