JP2001162616A - Self-cooling type rotary drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-cooling type rotary drill for ejecting a cooling from a drill bit and preventing chips from externally scattering in the rotary type drill for drilling the wall surface of a concrete building or the like. SOLUTION: When the drill bit is pressed by a surface to be drilled and moved, an inner cylinder jointed continuously to the bit is moved, the coolant externally supplied out of a casing is supplied to the guide hole of the cylinder through an outer cylinder, and ejected from the central hole of the continued bit. The chips are formed to liquid-like state by the coolant, and dropped in a storage chamber installed near the bit by a negative pressure in a cover covering the bit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coolant supply device for a self-cooling type rotary drill for making a hole necessary for repairing a wall surface of a building made of concrete or the like.

[0002]

2. Description of the Related Art A rotary drill is generally used as a device for drilling an existing wall for repairing a building's wall or performing seismic retrofitting, to prevent overheating caused by friction of a drill bit. In order to prevent the misery of cutting dust, a coolant such as water is supplied to a drill bit.

[0003] When water is used as a coolant, the water containing the cutting dust flows down or scatters on the wall surface to cause a great problem in the surrounding environment. Therefore, in order to solve the problem, aerosol is used instead of water. A device for supplying a mold coolant has been proposed as Japanese Patent Application Laid-Open No. H10-612. According to this proposal, cutting dust is taken into the aerosol, and the fluid part of the aerosol evaporates rapidly on the wall surface, so it is effective that the cutting dust adheres to the wall surface around the cutting location and does not scatter. .

[0004]

When the coolant is water, when drilling, water is supplied to the vicinity of the drill bit by opening a valve as needed, and the valve is closed and supplied when drilling is completed. The operation to stop was repeated. When using an aerosol-type coolant that is more expensive than water, the coolant is supplied by opening the valve, and the coolant supply is automatically stopped when the drill is not pressed against the surface to be cut. Otherwise, expensive coolant is wasted, and in JP-A-10-612, a control valve for that purpose is incorporated in the apparatus.

[0005] However, since drilling work on a concrete wall or the like is a destructive work in which an extremely large force is applied to a drilling device or tool, there is a possibility that such a force is applied to a control valve, and the operation is robust and simple. It does not matter that a simple structure is required. In that respect, the above-mentioned conventional example has much room for consideration. Although the idea of using an aerosol-type coolant to prevent the scattering of dust is acceptable, even if the aerosol evaporates in a very short time compared to water, it completely eliminates the great impact on the environment around the workplace. It cannot be removed. It is not possible to completely suppress the drying and scattering of the dust captured by the aerosol type coolant.

[0006]

SUMMARY OF THE INVENTION In the present invention, it is not necessary to select a specific liquid or aerosol as a coolant, but a design using an aerosol type coolant is considered. First of all, even when the drill is rotating, the structure is simple so that the coolant does not squirt unless the drill tip is pressed or strongly contacted with another object and the drill is moved along the rotation axis direction. The valve was designed to be effective.
The valve has an outer cylinder having a hollow lumen, and an inner cylinder that rotates integrally with the outer cylinder is housed in the lumen of the outer cylinder in a liquid-tight and slidable manner. The outer cylinder is rotatably supported by a casing via a bearing, and is further engaged with a driving motor housed in the casing. The casing is provided with a passage for taking in a coolant, and a liquid-tight coolant holding chamber is provided so as to cover the outer peripheral surface of the outer cylinder fixed to the shaft.The coolant supplied from the passage is supplied to the holding chamber. Stays in a pressurized state.

The outer cylinder is provided with an opening which opens into the storage chamber and is continuous with the inside of the outer cylinder. The enlarged diameter portion of the inner cylinder housed therein closes the opening from the inside. One end of the reduced diameter portion that is continuous with the enlarged diameter portion of the inner cylinder has an opening at the outer peripheral surface of the reduced diameter portion, and the other end has a conduction hole that is fixed to the drill bit and opens at the end portion. A seal ring is provided between the cylinder and the inner cylinder, and the opening of the outer cylinder and the conduction hole of the inner cylinder are liquid-tightly shut off.

A spring is stretched between the rotating shaft of the driving motor and the inner cylinder, and both are urged to separate from each other. The drill bit touches the surface to be drilled, and the inner cylinder opposes the spring. When the opening of the conduction hole moves to a position facing the opening of the outer cylinder, the coolant in the storage chamber is supplied to the drill bit through the opening of the outer cylinder and the conduction hole of the inner cylinder.

Further, the cover from the casing to the tip of the drill bit is air-tightly covered with a deformable cover, and the cover is opened only at that portion so that the tip of the drill bit can directly touch the surface to be drilled. By evacuating the air inside and installing a storage chamber for storing a mixture of the sucked coolant and the cutting dust near the tip of the drill bit, the scattering of the cutting dust to the outside is reliably prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a mechanism for supplying coolant of the drill of the present invention, and FIG. 2 shows a mechanism for collecting cutting dust. In the figure, reference numeral 1 denotes a casing in which a driving motor 2 and an outer cylinder 3 and an inner cylinder 4 are accommodated. Reference numeral 5 denotes a rotating shaft of the driving motor 2. The rotation is transmitted to the outer cylinder 3. The casing 1 rotatably supports the outer cylinder 3 by a bearing 6, and the inner cylinder 4 is housed in a hollow lumen 9 of the outer cylinder 3 and can rotate integrally with the outer cylinder 3.
It can slide inside the lumen 9. The casing 1 is provided with a passage 7 for coolant inflow, and the passage 7 is provided in a coolant storage chamber 8 formed on the inner surface of the casing 1 so as to surround the outer peripheral surface of the outer cylinder 3 in a liquid-tight manner. It is open.

The inner cylinder and the outer cylinder are described in more detail with reference to FIGS. 3 to 5. The inner cavity 9 of the outer cylinder 3 has an enlarged chamber 9a having a large inner diameter and a housing diameter chamber 9b connected to the enlarged chamber 9b having a small inner diameter.
An opening 10 is formed in the holding chamber 8 of the casing 1 from the reduced diameter chamber 9a. The inner cylinder 4 shown in FIG. 5 includes a housing diameter portion 4b accommodated in the reduced diameter material 9b of the outer cylinder 3 and an enlarged portion 4a accommodated in the enlarged chamber 9a of the outer cylinder 3 that is continuous with the diameter. In addition, a seal ring 11 is appropriately provided between the outer cylinder 3 and the inner cylinder 4 to maintain liquid tightness between the two. A drill bit 12 is fixed to the distal end of the reduced diameter portion 4b of the inner cylinder 4. A conduction hole 13 is formed inside the reduced diameter portion 4b along the axis of the reduced diameter portion 4b. And the other end is open to the outer peripheral surface of the reduced diameter portion 4b.

In the inner cavity 9 of the outer cylinder 3, the rotating shaft 5 of the driving motor 2 and the end of the enlarged portion 4a of the inner cylinder 4 face each other. A spring 16 is stretched between the inner cylinder projection 14 protruding from the inner cylinder 5 and the rotating shaft projection 15 to urge the rotating shaft 5 and the inner cylinder 4 to be separated. In FIG. 2, the drill bit 12 fixed to the distal end of the reduced diameter portion 4b of the inner cylinder 4 is covered with an elastic cover 17 over the entire length, and the vicinity of the distal end of the drill bit 12 is compressed and restored by a sponge or the like. An opening 19 is formed, which is covered by a cup 18 made of an easy material and faces the tip of the drill bit 12. A storage chamber 20 opens in the cup 18, and the storage chamber 20 further opens in the cover 17. A turbine 21 is fixed to the reduced-diameter portion 4b of the inner cylinder 4 protruding at a location close to the cover 17 of the casing 1, and the rotation of the inner cylinder 4 allows the air in the cover 17 to penetrate the casing 1 through the opening 22. To the outside.

In use, first, the power of the driving motor 2 is turned on, and the rotating shaft 5, the outer cylinder 3, the inner cylinder 4, and the drill bit 12 are rotated at high speed. Next, the coolant is filled into the storage chamber 8 via a hose (not shown) connected to the passage 7 or the like. The high-speed rotation of the inner cylinder 4 also rotates the turbine 21, whereby a negative pressure has already been generated in the cover 17. In this state, as shown in FIG. 2, when the tip of the cup 18 is pressed against the surface to be cut such that the holding chamber 8 is located below,
When the cup 18 is compressed and the tip of the drill bit 12 comes into contact with the surface to be cut, and the device is pushed further, the drill bit 12 starts to cut the surface to be cut, and at the same time, the inner cylinder 4 connected to the drill bit 12 springs. 16 and slides to the right in the drawing, so that the reduced diameter portion 4b of the inner cylinder 4 becomes the enlarged chamber 9a of the outer cylinder 3.
And the open end of one of the conduction holes 13 opened on the outer peripheral surface of the reduced diameter portion 4b is opened without the enlarged chamber 9a of the lumen 9 of the outer cylinder 3. At the same time, the coolant in the holding chamber 8 enters the enlarged chamber 9a of the inner cavity 9 through the opening 10 of the outer cylinder 3, and is further supplied to the center hole 12a of the drill bit 12 through the conduction hole 13 of the inner cylinder 4. The coolant is ejected from the tip of the drill bit 12.

The cutting dust generated in the vicinity of the tip of the drill bit 12 by the cutting is taken in a gel state by the coolant, and at the same time, is drawn into the cup 18 by the negative pressure inside the cover 17 and falls into the storage chamber 20, and the dust Outside scattering is completely prevented.

[0015]

According to the present invention, it is possible to obtain a self-cooling type rotary drill which has a very simple structure but has a reliable operation, can minimize cutting dust, and can reduce the driving dust by selecting a driving motor. There is an effect that the noise device can be easily designed.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view of the vicinity of a main body casing according to an embodiment of the present invention.

FIG. 2 is a conceptual cross-sectional view of the vicinity of a drill bit according to an embodiment of the present invention.

FIG. 3 is a sectional view of an outer cylinder and an inner cylinder used in the present invention.

FIG. 4 is a sectional view of an outer cylinder used in the present invention.

FIG. 5 is a sectional view of an inner cylinder used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Drive motor 3 Outer cylinder 4 Inner cylinder 5 Rotating shaft 6 Bearing 7 Passage 8 Reservation chamber 9 Inner cavity 10 Opening 11 Seal ring 12 Drill bit 13 Conducting hole 14 Inner cylinder projection 15 Rotating shaft projection 16 Spring 17 Cover 18 Cup 19 opening 20 storage chamber 21 suction hole

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C036 HH09 LL05 3C069 AA04 BA09 BB01 BB04 BC02 CA10 DA05 DA06 DA07 EA01 EA02

Claims (2)

[Claims] In a self-cooling rotary drill for supplying a coolant to the tip of a drill from a bore of a drill bit to cool the drill at the time of drilling, a drive motor housed in a casing and a rotary shaft of the drive motor are provided. A hollow outer cylinder engaged and rotatably supported by the casing via a bearing in a fluid-tight and rotatable manner; and a liquid-tight inside the hollow bore of the outer cylinder engaged with the outer cylinder. And an inner cylinder slidably accommodated therein. A passage is provided in the outer cylinder to allow the coolant supplied to the casing to pass therethrough, and the coolant flowing from the passage is provided in the outer cylinder in the inner cavity. The inner cylinder is provided with a conduction hole that feeds the coolant flowing from the outer cylinder opening to the drill bit, and the drill bit is liquid-tight at the end of the inner cylinder where the conduction hole opens. To be fixed to the shaft of the drive motor. When the drill bit is not in contact with the surface to be drilled, the inner cylinder is urged to be separated by a spring, and the flow of the coolant is shut off in a liquid-tight manner between the opening of the outer cylinder and the conduction hole of the inner cylinder. A self-cooling rotary drill. 2. A cover from the casing to the tip of the drill bit is airtightly covered with a deformable cover, the tip of the drill bit is opened so that it can directly touch the surface to be drilled, and the air in the cover is sucked toward the casing. 2. The self-cooling rotary drill according to claim 1, further comprising a storage chamber for discharging the mixture of the coolant and the cutting dust sucked near the tip of the drill bit.