JPH0475813A - Core drill - Google Patents

Abstract

PURPOSE:To simplify coupling and separation of a top plate and a core body by a method wherein the ball for engagement of a core body mounting part on the top plate side is protruded for engagement with the engaging hole of the upper end opening of the core body through energization by means of a spring, in a core drill for drilling for a concrete material. CONSTITUTION:When a core body mounting part 3 of a top plate 1 is inserted in an engaging manner in the upper end opening part of a core body 9, the upper end opening edge of the core body 9 is brought into up slide contact with balls 7 for coupling to press in the balls. The balls 7 for coupling coincide with respective engaging holes 11 and engaged in a protruding manner therewith to intercouple the top plate 1 and the core body 9. When, with this state, a force for drawing the top plate 1 and the core body 9 away from each other in the direction of an axis is applied, a part of a force applied in a down state from the edge of the engaging hole 11 making contact with the ball for coupling is exerted on the ball 7 for coupling in a direction in which the ball 7 for coupling is pulled out in an out direction to prevent separation of the top plate 1 for coupling away from the core body 9. During a drilling work, rotation torque from the top plate 1 side is transmitted to the core body 9 by pressing the end of the engaging hole 11 by means of the ball 7 for coupling. A part of the press force is exerted so as to stabilize a coupling relation between the top plate 1 and the core body 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a core drill used for drilling relatively large diameter holes in concrete materials and the like.

(Prior art) A wide variety of core drills have been developed and commercially available for single-hole large-diameter holes, and these core drills are equipped with drilling blades adapted to the material of the object to be drilled. .

By the way, in a core drill for solidified concrete, a drilling blade made of a cemented carbide tip is provided at the periphery of the opening at the bottom of the cylindrical core body, and the side surfaces of this drilling blade are located inside and outside the core body. It has a thick shape that protrudes slightly from both sides.

In this way, when drilling a through hole in concrete using a core drill equipped with protruding drilling blades on both the inner and outer surfaces of the core body, a cylindrical hole is drilled inside the core body after drilling. A cut lump that has been pierced remains, but the drilling blade protruding toward the inner surface of the core body obstructs the removal of this cut lump toward the lower end opening side of the core body, making it difficult to pull it out.

Therefore, in order to make it easier to remove the cutting lump from the core body, the core body is constructed separately from the top plate which is integrated with the shank, and after drilling, the two are separated 1-2 to remove the cutting lump from the core. A core drill has been proposed which is designed to be extracted from the upper opening side of the body.

[Problems to be Solved by the Invention] However, in the conventional Coretril, in which the top wall and the core body are separate bodies, a joint structure between the top wall and the core body, etc. is adopted. It takes time and effort to connect and separate the two, resulting in poor workability, and there are also problems such as repeated use of the screw structure wears out and adversely affects the connection relationship between the two.

This invention was made in view of the above points, and it is easy to connect and separate the top wall and the core body, making it convenient to handle, and the connection relationship remains unchanged even after repeated use (7). The purpose is to provide a core drill with high performance and excellent workability.

[Means to solve the problem]

In order to achieve the above object, the old roller has a top wall having a shank at the center of the upper surface, and an opening F at the bottom end.
′] Consists of a cylindrical core body with a perforation blade on the edge, and a core body mounting part JJ is formed on the top wall.The core body is attached from the top of the top wall toward the circumferential surface of the top wall axis. 7, tilting toward the heart
and providing a plurality of holding holes inclined in the radial direction of the top wall,
The coupling ball is fitted and held in the holding hole by the force of the spring 2, and the core body is attached to the -J2 part of the core body into which the part is inserted. The core drill is characterized in that it has an end opening C5 and an engagement hole into which the coupling ball engages and disengages.

[Function] To attach the core body on the top wall, when the part of the core body is inserted into the upper end opening of the core body, the opening diameter at the second end of the core body slides upward against the connecting ball and pushes it in, causing the connecting ball to is aligned with the engagement hole, and the protruding engagement 1-1 top plate and the core body are coupled.

When a force is applied to separate the top wall and the core body in the axial direction while the top wall and the core body are connected, the coupling ball will receive part of the force applied downward from the edge of the engagement hole that comes into contact with it. The portion acts in a direction to pull the coupling ball outward and prevents separation of the top wall and the core body.

When rotating in the drilling direction during drilling work, the rotational torque from the top wall side is transmitted by pressing the engagement hole edge where the coupling ball protrudes and engages with the core body. A portion of the connecting ball is pulled outward and acts in one direction to stabilize the connecting relationship between the top wall and the core body, and the seven holes are made.

When the core body is rotated relative to the top wall in the opposite direction to that for the seven holes, the edge of the engagement hole of the core body slides into horizontal contact with the coupling ball and pushes the coupling ball, When the top wall and the core body are pulled apart in the axial direction when the coupling ball is pulled out from the engagement hole, the two are separated.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is an exploded perspective view of the core drill of the present invention, FIG. 2 is a front view of the top wall, and FIG. 3 is a partially cutaway plan view of the top wall.

In the figure, 1 is a top wall, and has a shank 2 at the center of the top surface. , 3 is a core body attachment part formed on the top wall 1, and one part has a stopper flange 4.

Reference numeral 5 denotes a plurality of holding holes provided from the top wall 1-F toward the circumferential surface of the core body mounting portion 3, and the holding holes 5 are inclined at a predetermined angle with respect to the axis of the top wall. In addition, it is inclined at a predetermined angle with respect to the radial direction 62 of the top wall, and has an opening 6 on the circumferential surface of the core body mounting portion 3, and this opening 6 prevents the coupling ball, which will be described later, from being pulled out. Therefore, it has a slightly constricted configuration.

Reference numeral 7 denotes a coupling ball that is fitted and held in the holding hole 5, and is biased toward the opening 6 by a spring 8B in the holding hole 5, so that a part of the coupling ball 7 protrudes from the opening 6. .

9 is a cylindrical core body with a drilling blade 10 provided at the periphery of the opening at the lower end, and the drilling blade 10 in the embodiment is made of a cemented carbide tip knob, and is suitable for drilling into concrete 1 to etc. The side surfaces of the drilling blade 10 are slightly protruded from both the inner and outer surfaces of the core body.

Reference numeral 11 denotes an engagement hole, which is provided at the opening at the two ends of the core body 9 corresponding to the coupling ball 7, and through which the coupling ball 7 engages and disengages on the circumferential surface of the core body 9. It is adapted to the size of the protruding coupling ball 7.

In addition, 12 in the figure is a cover plate fixed to the upper surface of the top wall 1 in a superposed manner;
Reference numeral 3 denotes a pressing piece that is inserted into the holding hole 5 and presses and holds the spring 8 in a compressed state.

In the above configuration, the inclination direction of the holding hole 5 with respect to the top wall axis and the top wall radial direction is the direction in which the opening 6 is opposite to the rotation direction at the time of drilling, and the respective inclination angles are as follows. It is set by satisfying the following conditions.

(a) When attaching the core body, the part 3 is inserted into the upper end opening of the core body 9. As shown in FIG. When the upper end opening edge of the core body 9 presses upward, the upper end opening edge of the core body 9 comes into sliding contact with the coupling ball 7 and pushes the coupling ball 7 into the holding hole 5.

(b) With the top wall 1 and the core body 9 connected, the fifth
As shown in the figure, when a force is applied to separate the top wall 1 and the core body 9 in the axial direction, a force is applied to the coupling ball 7 in a downward direction through the engagement hole edge, and the coupling ball 7 does not move and prevents separation of the top wall 1 and the core body 9.

(C) When the top wall 1 and the core body 9 are combined and rotated in the drilling direction as shown in FIG. The cohesive relationship between the wall l and the core body 9 is stabilized.

(d) As shown in FIG. 7, the core body 9 is attached to the top wall l.
When relatively rotating in the direction opposite to the above-mentioned drilling direction,
The coupling ball 7 is pressed sideways by the edge of the engagement hole, and the edge of the engagement hole slides into contact with the coupling ball 7, pushing the coupling ball 7 into the holding hole 5, and separating the top wall 1 and the core body 9. or make it possible.

(Effects) The core drill of the present invention configured as described above has the following effects.

(1) The top wall and the core body are connected via a connecting ball, and the connection is achieved by fitting the core body attachment part of the top wall into the upper end opening of the core body, and then engaging the core body. Since it is only necessary to engage the coupling ball on the top wall side with the hole, it can be easily done with one touch, improving work efficiency.

(2) The top wall and the core body can be separated by rotating the top wall and the core body slightly relative to each other to release the coupling ball from the engagement hole, and then pulling it in the axial direction. Since the top wall and the core body can be separated from each other, the top wall and the core body will not be accidentally separated, making handling convenient.

(3) Since a plurality of holes are simply drilled in the upper end opening of the core body, when removing the cutting lump remaining inside the core body after the drilling operation, the core body There are no protrusions inside the body that can get in the way (it makes it easy to take out the cutting lumps, and there is no wear and tear even with repeated use.
The service life will be extended.

(4) If the joint between the top wall and the core body is standardized, multiple types of core bodies with different types of drilling blades can be used in common for one top wall. Penetration with different
It is convenient for replacing the core body when the drilling blade is worn out, and is economical and highly versatile.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the core drill of the present invention, FIG. 2 is a front view of the top wall, and FIG. 3 is a plan view with a portion of the top wall removed.
FIG. 4 is a vertical cross-sectional view of the main part to explain the connection between the top wall and the core body, FIG. 5 is a vertical cross-sectional view of the main part to explain the connection state of the top wall and the core body, FIG. 6 is a cross-sectional view of the main part for explaining the drilling process, and FIG. 7 is a front view of the main part for explaining the separation of the top wall and the core body. DESCRIPTION OF SYMBOLS 1... Top wall, 2... Shank, 3... Core body mounting part, 4... Stopper flange, 5... Holding hole, 6...
...Opening, 7...Ball for connection, 8...Spring, 9.
...Core body, 10...Drilling blade, 11...Engagement hole, 1
2... Cover plate, 13... Pressing piece. Figure 1 Figure 4 Figure 6 Figure 2 Figure 3 Figure 7

Claims (1)

[Claims] It consists of a top wall with a shank in the center of the top surface, and a cylindrical core body with a drilling blade provided around the opening at the lower end. A plurality of holding holes are provided that are inclined in the axial direction of the top wall and in the radial direction of the top wall, and the coupling balls are fitted and held in the holding holes by being biased by a spring. A core drill characterized in that an engagement hole into which a coupling ball engages and disengages is provided in the upper end opening of the core body, which protrudes from the circumferential surface of the core body attachment part and into which the core body attachment part is inserted.