JPS63212405A - Device for cutting upward wide diameter hole - Google Patents

Abstract

PURPOSE:To cut an upward wide diameter hole at an appropriate location in a straight hole by projecting a cutting blade body from the upper side of a center shaft which is simultaneously rotated as it makes a vertical motion through an L letter like crank, while the bottom surface of a stop sleeve is in contact with the straight hole surface in a concrete. CONSTITUTION:A shank 2 is mounted on a rotational vibration type boring device and a center shaft 3 is inserted into a straight hole A bored in a concrete beforehand. Next, the said boring device is driven while the bottom surface of a stop sleeve 12 is in contact with a concrete surface B and held at a fixed position. The boring machine body makes its shaft 3 vibrate in a vertical direc tion through an L letter like crank 16 as the body itself makes one turn. Fur ther, the tip of a cutting blade body 9 is rotated as it is worked in and out from the upper end side of a storage hole 7 located at the under end of the shaft 3 to the side of the shaft 3. As a result, the hole portion C of an upward wide diameter is cut on the hole wall at the inmost portion of the straight hole A thus, enables a device of simple structure and excellent durability to cut a required hole.

Description

Detailed Description of the Invention (Industrial Application Field) This invention involves cutting an enlarged diameter hole portion in a pre-drilled hole wall at a suitable location, the diameter of which is larger than the drill diameter and whose diameter is directed upward. It is related to the device.

(Prior art) In order to increase the pull-out strength of the anchor bolt when planting the anchor bolt in solidified concrete, this device is used as a device to drill an enlarged diameter hole at an appropriate position in a straight hole as a pilot hole, in order to increase the pull-out strength of the anchor bolt. For example, in a method filed by the present applicant and already published (Japanese Unexamined Patent Publication No. 191706/1983), an external force on the protruding jaw is applied by moving the cutting blade along the protruding jaw that gradually expands downward and laterally. There is a structure in which the enlarged diameter hole is cut by rotating the main body of the device while protruding from the hole.

(Problems to be Solved by the Invention) According to the conventional creating device described above, it is possible to cut an enlarged diameter hole portion in which the pull-out strength of the anchor bolt is enhanced compared to a straight hole, but the shape of the enlarged diameter hole portion is Since the diameter of the anchor bottle gradually expands downward (in the opposite direction to the bolt withdrawal direction), it can be said that the resistance against bolt withdrawal is extremely large.However, although the anchor bottle is connected to the expanded diameter hole wall, Since it was not in an engaged state, it was not possible to completely prevent the bolt from being pulled out.

This invention has been made in view of the above-mentioned points, and it is possible to cut an enlarged diameter hole whose diameter is gradually enlarged upward, and it is possible to engage the anchor bolt with the engagement step at the upper end of the enlarged diameter hole, thereby increasing the bolt's pull-out strength. The purpose of this invention is to provide an apparatus for cutting an enlarged diameter hole, which can significantly increase the number of holes.

(Means for Solving the Problems) The gist of the present invention for achieving the above-mentioned object is to form a cylindrical body having a shank at the upper end and an open lower end, and to form a body that is integrally formed with the shaft core. A center shaft is inserted so that it can rotate and move relatively within a certain range under the bias of a spring, and a cutting blade body is attached to the lower end of the center shaft so that it can be expanded laterally from its upper end. The blade body is biased inward of the center shaft by a spring, and an operating rod for deploying the cutting blade body is movably loosely inserted into the axial center portion of the center shaft, so that the operating rod is freely movable around the outer circumference of the center shaft. The bent part of the abbreviated crank is arranged around the stop ring so that it can swing freely, one end of the crank is engaged with the center shaft, and the other end is connected to the main body. By abutting the lower end and moving the main body closer to the stop ring against the spring, the cutting blade body is made to project laterally via the operating rod.

(Function) When the cutting device of the present invention is mounted, the shank is attached to a rotary vibration type or rotary hammer type drilling device, the main body is inserted into a straight hole previously drilled in concrete, and the main body is inserted into the concrete surface. By performing drilling work with the bottom surface of the stop sleeve in contact, the center shaft to which the cutting blade is attached rotates while moving up and down through the swinging action of the abbreviated crank, and as it moves up and down, the stop sleeve The cutting blade body comes into contact with the operating rod which is integrally joined to the center shaft and held in place, and the cutting blade body extends from above to the side of the center shaft. The hole is cut at the appropriate location.

(Example) Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a central cross-sectional view of the cutting device of the present invention at the start of work, Fig. 2 is a longitudinal cross-sectional view of the same center with the main body pressed down at the end of work, and Fig. 3 is the - (2) A view taken along the line, FIG. 4 is a view taken along the 1"/-IV line in FIG. 1.

In these figures, 1 is a cylindrical body with a shank 2 at the upper end and an open lower end, 3 is a center shaft whose upper part is loosely inserted into the main body 1 so as to be movable, and the upper end of the center shaft 3 has a cylindrical body with a shank 2 at the upper end. A vertically elongated insertion hole 4 is formed, and the center shaft 3 is rotated integrally with the main body 1 through a pin 5 that is loosely inserted through the insertion hole 4 so as to be vertically movable and vertically move within a certain range. It is inserted so that it can move freely. Further, a spring 6 is interposed between the main body 1 and the center shaft 3, and the center shaft 3 is biased downward.

Further, a blade accommodation hole 7 is formed at the lower end of the center shaft 3 and extends laterally. Furthermore, a center hole 8 is bored in the axial core portion of the center shaft 3 and communicates with the accommodation hole 7 from an intermediate portion thereof.

9 is a pair of plate-shaped cutting blades having a semicircular base and an isosceles triangular tip, and each blade 9 has a cutting blade 9 at the tip of the outer periphery.
A is formed. The base of each cutting blade 9 is rotatably attached to the lower end of the housing hole 7 with a pin 10, and the tip of each cutting blade 9 is expanded in the direction of separation from the upper end of the housing hole 7. It is configured so that it can extend from the side to the side of the center shaft 3. Reference numeral 11 denotes a spring interposed between each cutting blade body 9, and this spring 11 biases the tip end of each cutting blade body 9 in a direction toward which it closes, or in other words, urges the tip side of each cutting blade body 9 toward the inside of the accommodation hole 7. It is installed like this.

12 is a stop sleeve movably covered on the outer periphery of the center shaft 3 below the main body 1; 13 is an operating rod that is movably loosely inserted into the center hole 8 of the center shaft 3;
Reference numeral 4 denotes a vertically elongated insertion hole drilled horizontally through the upper end of the center hole 8 of the center shaft 3, and a pin 15 inserted loosely through the insertion hole 14 so as to be movable in the vertical direction is used for operation. The upper end of the rod 13 is integrally joined to the lower end of the stop sleeve 12.

Reference numeral 16 denotes an abbreviated crank having a hemispherical body 16a protruding from the lower end surface near the bent portion, and a pair of recesses L2a are formed opposite each other on the upper surface of the stop sleeve 12, and each recess L2a
The hemispherical body Lea of the crank 16 is swingably disposed on the center shaft 3, and the crank 1 is disposed on the center shaft 3.
Engagement grooves 17 are opened corresponding to the engagement grooves *17, and one end of the crank 16 is loosely inserted into each engagement *17 so as to be swingable. Further, the lower end portion 1a of the main body 1 is formed into a downward conical shape, and is brought into contact with the upper end of the crank 16. In this way, with the stop sleeve 12 held in place, by pushing the main body 1 down against the spring 6 and approaching the sleeve 12, the crank 16 is moved outwardly and upwardly, and the center shaft 3 is also moved against the spring. 6, and the operating rod 13 is held in place together with the stop sleeve 12, so the lower end of the operating rod 13 slides downward along the inner peripheral edge of the cutting blade 9. The blade body 9 projects laterally from the upper end side of the accommodation hole 7.

On the other hand, when the downward force of the main body 1 is removed and the main body 1 is pushed upward by the urging force of the spring 6 and separated from the stop sleeve 12, the crank 16 swings inward and downward, and the center shaft 3 As it is lowered by the biasing force of the spring 6, the lower end of the operating rod 13 slides upward along the inner peripheral edge of the cutting blade 9 and moves away from the pivot pin 10 of the cutting blade 9, and the tip of the cutting blade 9 The center shaft 3 is closed inward by the biasing force of the spring 11, and the housing hole 7 is closed.
taken back inside.

Next, the manner of use of the above embodiment will be explained. As shown in Fig. 1, the shank 2 is attached to a rotary vibration type drilling device (not shown), the center shaft 3 is inserted into a straight hole A previously drilled in the concrete, and the lower surface of the stop sleeve 12 is placed on the concrete surface B. Abut and hold in place. In this state, when the drilling device is driven to rotate the main body 1 and vibrate it in the vertical direction, the tip of the cutting blade 9 is moved from the upper end side of the accommodation hole 7 at the lower end of the center shaft 3 to the side of the center shaft 3. It rotates while moving in and out of the straight hole A, and an enlarged diameter hole portion whose diameter expands upward is gradually cut in the hole wall at the back of the straight hole A. In this way, the enlarged diameter hole C shown in FIG. 2 is finally cut.

In order to simplify the explanation, the shank 2 of the device is taken as the upper end and the blade 9 side is taken as the lower end. Alternatively, the same method can be applied to horizontally oriented straight holes. Further, the crank 16 may be swingably disposed relative to the stop sleeve 12 via, for example, a pivot pin, and further, by bringing the main body 1 close to the stop sleeve 12, the crank 16 is caused to swing outward and upward. As a construction, instead of forming the lower end portion 1a of the main body into a conical shape as in the above embodiment, for example, there is a method in which the contact portion of the crank 16 with respect to the main body I is formed into a tapered shape.

(Effects) As explained above, since the enlarged diameter hole cutting device of the present invention has the above-described configuration, it has the following effects.

That is, since the diameter of the expanded hole drilled by the cutting device of the present invention expands upward, in other words in the direction in which the anchor bolt is pulled out, there is a gap between the upper end of the expanded hole and the wall of the straight hole. Because an engagement stage is formed, when planting an anchor bolt in concrete, etc. that is solidifying, by using an anchor bolt with an engagement part with the engagement stage, it is possible to avoid the conventional downward expansion. Compared to installing an anchor bolt in a hole with a diameter, the pull-out strength is greatly increased, and even when the properties of the material to be drilled are weaker than concrete, the anchor bolt can be installed reliably and firmly. can be planted. Furthermore, since the operation of pushing up the center shaft relative to the stop sleeve is performed through the oval-shaped crank, the structure is simple and durable, and it can be used stably for a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a central vertical cross-sectional view of the cutting device according to the embodiment of the present invention at the start of work, FIG. 2 is a central vertical cross-sectional view of the same with the cylindrical body pressed down at the end of work, and FIG. 1 is a view taken along the line III-I, and FIG. 4 is a view taken along the line ■-IV in FIG. l... Cylindrical body, 2... Shank, 3... Center shaft, 4.14... Insertion hole, 5.10.15
．． ...Pin, 8.11. ... Spring, 7 ... Accommodation hole, 8 ... Center hole, 9 ... Cutting blade body, 9a ... Cutting blade, 12 ... Stop sleeve, 13 ... Operating rod,
16... Abbreviated crank, 17... Engagement groove.

Claims (1)

[Claims] A cylindrical body with a shank at the top end and an open bottom end,
A center shaft is inserted into the main body so that it can rotate together with the main shaft and can move relative to each other within a certain range under the bias of a spring, and a cutting blade is extended from the upper end side to the side at the lower end of the center shaft. At the same time, the cutting blade body is urged inward of the center shaft by a spring, and an operating rod for deploying the cutting blade body is movably loosely inserted into the axis of the center shaft. is integrally joined to a stop ring movably mounted on the outer periphery of the center shaft, and the vicinity of the bent portion of the substantially L-shaped crank is swingably disposed on the stop ring, so that one end of the crank is engaged with the center shaft. At the same time, by bringing the other end into contact with the lower end of the main body and moving the main body against the spring and approaching the stop ring, the cutting blade body is extended laterally via the operating rod. An upwardly expanding hole drilling device characterized by: