JP2013129989A - Cutting device and anchor fixing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting device which is excellent in workability and an anchor fixing method for hardly generating noise or vibration, and for easily forming a groove with predetermined depth on the internal wall surface of a hole.SOLUTION: The cutting device for cutting a groove 30 on the internal wall surface of a hole 10 formed in existing concrete includes: a base 11 connected to a rotary shaft 8 of a driving part M, and configured so as to be inserted into the hole 10; a bending part 14 extending from the lower end face of the base 11 vertically downward and bending in the middle; a spring part 15 attached to the lower end face of the bending part 14; and a cutting part 18 fixed via a connector 17 to the lower end face of the spring part 15, and mounted with a cutting blade 18a in the circumference.

Description

  In the present invention, an existing concrete molded body (hereinafter referred to as “existing concrete”) is drilled to form a hole (hereinafter referred to as “concrete hole”), and then a groove is formed on the inner wall surface of the concrete hole. The present invention relates to a cutting apparatus for performing a cutting process and an anchor fixing method using the cutting apparatus.

  For example, it is generally known that existing concrete such as piers that support bridges and foundation structures that support pedestals of power transmission towers need to be strengthened or improved in seismic performance as they age. ing.

  As a technique for improving the seismic performance and strength of such existing concrete, a hole having a predetermined depth is provided in the existing concrete using a drilling machine, and then a reinforcing bar (hereinafter referred to as “anchor”) is provided in the concrete hole. An anchor fixing method is known in which a grouting material (non-shrink mortar, epoxy resin, or the like) is poured into the anchor and the anchor is fixed.

  In such a conventional anchor fixing method, it is necessary to firmly fix the anchor. For this purpose, the adhesion force between the grout material and the inner wall surface of the concrete hole is an important factor. Here, although the adhesion between the grout material and the anchor is good, the adhesion between the grout material and the inner wall surface of the concrete hole is inferior to the adhesion between the reinforcing bar. As this factor, it is conceivable that fine dust such as concrete cutting powder adheres to the inner wall surface of the concrete hole and inhibits the adhesion force with the grout material.

  Therefore, in a general anchor fixing method, since the adhesion force between the inner wall surface of the concrete hole and the grout material is superior to the adhesion force with the anchor, it is desirable that the anchor fixing length be 15 times or more the diameter of the reinforcing bar.

  On the other hand, since the external force transmitted from the reinforcing bar is substantially parallel to the inner wall surface of the concrete hole, there is a problem that when the external force is applied to the concrete molded body, the reinforcing bar easily leaves the concrete hole together with the surrounding concrete.

  In order to solve this problem, a technique for forming a groove on the inner surface of a hole has been studied. For example, an apparatus in which a cutter is attached to the tip of a rotating shaft that is rotated by a motor is disclosed (see Patent Document 1). ).

  The apparatus described in Patent Document 1 is an apparatus that rotates a cutter and cuts a wall surface with the cutter to form a groove on an inner wall surface of a hole.

Japanese Patent No. 3692303

  However, the apparatus disclosed in Patent Document 1 is not only increased in noise because the vibration of the cutter is directly transmitted to the rotating shaft when cutting the inner wall surface of the concrete hole, so that the motor for rotating the cutter causes the vibration. There is a problem that the lifetime of the apparatus is short.

  In addition, the cutter is likely to vibrate, and the grooves formed by cutting are uneven in shape, which makes it difficult to obtain a groove having a certain depth.

  On the other hand, in the anchor fixing method described above, a large number of reinforcing bars are arranged in a plurality of stages inside the existing concrete, and it is required to fix the anchor without cutting the reinforcing bars. And, generally, the position of the existing concrete rebar is searched with a rebar probe, and the hole is drilled away from the rebar located inside. Exploration is not possible. Therefore, when the hole is in contact with the reinforcing bar at a deep position, the position of the hole must be changed, which requires labor and labor such as drilling again, and the workability of anchor fixing work (work) Sex) was bad.

  Therefore, the present invention has been made with the above problem as an example, and it is difficult to generate noise and vibration, can easily form a groove with a predetermined depth on the inner wall surface of the hole, and has excellent workability. An object of the present invention is to provide a cutting device and an anchor fixing method.

  In order to solve the above-mentioned problem, the cutting device according to claim 1 is a cutting device that cuts a groove (30) in an inner wall surface of a hole (10) formed in existing concrete, and includes a drive unit (M ) And a base portion (11) inserted into the hole, and a bent portion (14) extending vertically from the lower end surface of the base portion and bent in the middle thereof. And a spring portion (15) attached to the lower end surface of the bent portion, and a cutting portion (fixed to the lower end surface of the spring portion via a connecting member (17) and having a cutting blade (18a) attached to the periphery ( And 18).

  Moreover, the cutting device according to claim 2 is the cutting device according to claim 1, wherein a restriction body (25) that extends in a vertical direction on both sides of the spring portion and restricts a bending direction is attached to the base portion. It is characterized by.

  The cutting device according to claim 3 is the cutting device according to claim 1 or 2, wherein the base portion, the bent portion, the spring portion, and the cutting portion are detachably connected to each other. And

  Moreover, the cutting device according to claim 4 is the cutting device according to claim 2 or claim 3, wherein at least the base and the inside of the bent portion are formed with a flow path through which water can pass, The regulating body is formed with a hole (25a) for guiding water that has passed through the flow path to the inner wall surface of the hole.

  Further, the anchor fixing method according to claim 5 is connected to the rotating shaft of the drive unit, and extends vertically downward from the base portion inserted into the hole formed in the existing concrete, and the lower end surface of the base portion, Cutting with a bent portion formed by bending in the middle thereof, a spring portion attached to the lower end surface of the bent portion, and a lower end surface of the spring portion fixed via a connecting member, and a cutting blade attached to the periphery An anchor fixing method in which a groove is cut in an inner wall surface of the hole using a cutting device having a portion, and an anchor is fixed in the hole, and a drilling step for drilling the concrete, and the cutting device Cutting blade insertion step of inserting the cutting blade into a hole formed by drilling, and a groove forming step of forming a plurality of grooves on the inner wall surface of the hole formed in the concrete by the cutting blade in the vertical direction of the hole And in the hole It is inserted a linker, characterized by comprising an anchor fixing step of injecting grout, the.

  According to the present invention, a groove having a predetermined depth can be formed on the inner surface of a hole while suppressing noise and vibration while having a simple structure. In addition, the workability (workability) of anchor fixing work can be improved.

It is a side view which shows the example of a cutting device typically. It is an external view of a cutting tool. It is an external view which shows the example of improvement of a cutting tool. It is AA sectional drawing of FIG. FIG. 5A is a diagram illustrating a concrete hole drilling process, FIG. 5B is a diagram illustrating a groove forming process in the deepest portion, and FIG. 5C is a diagram for explaining an anchor fixing method. The figure which shows the formation process of a some groove | channel, FIG.5 (d) is a figure which shows an anchor fixing process.

  Hereinafter, the best embodiment of the present application will be described with reference to the accompanying drawings.

―About the structure of the cutting device―
The cutting apparatus according to the present embodiment includes a base 2 including a motor M and a cutting tool 1 coupled to a rotation shaft of the motor M. As shown in FIGS. 1, 2, and 5, the cutting tool 1 cuts a groove 30 on an inner wall surface of a hole formed in concrete (hereinafter referred to as a concrete hole 10), and includes a motor M The rotary shaft 8 is used by being connected. The motor M is provided on the base 2 that can move in the vertical direction by the operation of the operation lever 4 so that the rotating shaft 8 extends in the vertical direction.

  The cutting tool 1 is connected to the rotating shaft 8 of the motor M via an extension member 5 and extends vertically downward from the base 11 inserted into the concrete hole 10 and the lower end surface of the base 11, and in the middle A bent portion 14 formed by bending at a bending portion 14, a spring portion 15 attached to the lower end portion of the bent portion 14, and a lower end portion of the spring portion 15 fixed via a connecting member 17, and a cutting blade 18 a at the periphery. And an attached cutting part 18.

  The extension member 5 is formed by connecting cylindrical members 5a having a predetermined length, and each member 5a is formed with male and female screws at upper and lower ends, and is connected by screwing. This adjusts the required length. In the present embodiment, the length of the extension member 5 is appropriately adjusted according to the depth of the concrete hole 10, and the extension member 5 shown in FIG. 1 is obtained by connecting four members 5a.

  And the cutting tool 1 of this embodiment is inserted in the concrete hole 10 by the moving mechanism provided in the base 2, rotates the cutting part 18 by rotating the rotating shaft 8 of the motor M, and the cutting blade 18a. Can be formed on the inner wall surface of the concrete hole 10 by contacting the inner wall surface of the concrete hole 10.

  The base 11 is formed in a cylindrical shape slightly smaller in diameter than the inner diameter (diameter) of the existing concrete hole 10 to be inserted, and screw grooves are formed at both ends thereof, and the rotation of the motor M is performed by screwing. It is connected to the shaft 8. Moreover, when the concrete hole 10 is deep, the base 11 is connected with the rotating shaft 8 of the motor M through the extension member 5, as shown in FIG.

  If the diameter of the base 11 is too small with respect to the concrete hole 10, when the cutting tool 1 is driven, the swing of the base 11 becomes too large, and the cutting blade is stably centered on the axis of the base 11. Since the groove 18a does not rotate stably without being rotated, it is preferable that the base 11 having a diameter slightly smaller than the inner diameter of the concrete hole 10 is appropriately used in accordance with the shape of the concrete and the hole 10 as described above. .

  The bent portion 14 has a cylindrical shape and is formed with thread grooves at both ends thereof, and is connected to the base portion 11 and the spring portion 15 so as to be detachable by screwing. Further, the base portion 11 and the bent portion 14 have a hollow portion in the structure, and the hollow portions are connected so as to communicate with each other, and water as a lubricant is used by the hollow portion during the cutting process. Inflow. The water flows to the inner wall surface of the cutting portion 18 and the concrete hole 10 by leaking from the spring portion 15 or the like.

  The spring portion 15 uses a spring generally called a coil spring in which a metal wire is spirally wound, and both ends are connected to the bent portion 14 and the connecting body 17 by screwing. Since the coil spring is bent by being bent or deformed irregularly, particularly when the coil spring is long, when the cutting tool 1 is driven to perform cutting, the cutting portion 18 is inside the concrete hole 10. Therefore, the position is not stable and the groove having a uniform shape cannot be formed. Therefore, in the present embodiment, as shown in FIGS. 3 and 4, a restricting body that restricts the bending direction of the coil spring by sandwiching both sides of the spring portion 15 so that the coil spring moves stably in one direction. Provided. This restricting body is configured by providing a plate-like body 25 having a substantially U-shaped cross section at the outer peripheral edge of the spring portion 15, and the upper end portion is fixedly attached to the lower end surface of the base portion 11, and the lower end portion is vertical. It extends downward and is arranged so as to have a predetermined distance from the coil spring.

  In addition, since a coil spring should just be deform | transformed stably linearly, you may make it arrange | position a pair of metal plate-shaped bodies which have a predetermined | prescribed width | variety at least on both sides of the spring part 15 in parallel.

  Since the plate-like body 25 configured in this manner does not move irregularly and the movement of the spring portion 15 is restricted in one direction (or two directions in the front-rear direction), the position of the cutting blade 18a is stabilized, and the concrete hole A groove having a uniform shape can be formed on the ten inner walls.

  A plurality of through holes 25a are formed on the rear end surface of the plate-like body 25 with a certain interval in the vertical direction. And at the time of cutting, the water which flows through the cavity part of the base 11 and the bending part 14 flows into the inner wall face of the concrete hole 10 through the said through-hole 25a.

  As shown in FIG. 4, the cutting portion 18 includes a connecting portion that is detachably connected so as to fit inside the connecting body 17, and a protruding portion 27 that is formed by projecting a lower peripheral edge of the connecting portion. A plurality of cutting pieces 18a are attached to the periphery of the projecting portion 27 with a constant interval. Further, the cutting piece 18 a has a predetermined gradient with respect to the rotation axis, and is arranged so that the lower end of the cutting piece 18 a is in contact with the inner wall surface of the concrete hole 10 obliquely. The number of cutting pieces 18a is not particularly limited to four, and may be three or two cutting pieces 18a so as to be symmetrical with each other.

  As described above, according to the cutting tool of the present embodiment, the cutting piece is pressed by the pressing force of the spring portion, the inner wall surface of the concrete hole is cut by the rotational force of the motor, and a groove having a certain depth is formed. can do.

  Moreover, since the plate-like body 25 is attached as a restricting body that extends in the vertical direction on both sides of the spring portion 15 and restricts the bending direction, the spring portion 15 can be stably deformed linearly, and the cutting portion The position 18 is stable, and a groove having a uniform shape can be formed on the inner wall surface of the concrete hole 10.

  Moreover, since the said base part, a bending part, a spring part, and the cutting part are each connected so that attachment or detachment is possible, it can change for every member by deterioration etc.

  Further, when performing the cutting process, it is necessary to apply water as a lubricant for protecting the cutting blade to the cutting part 18 and the cutting part. In the cutting tool 1 of the present embodiment, the base 11, In addition, a flow path through which water can pass is formed inside the bent portion 14, and the plate-like body 25 disposed on both sides of the coil spring has a hole in which the water that has passed through the flow path is formed. Since the plurality of holes 25a for guiding to the inner wall surface are formed, water can be distributed and guided to the inner wall surfaces of the cutting portion 18 and the concrete hole 10.

―About anchor fixing method―
Next, an anchor fixing method using the cutting apparatus of this embodiment will be described.

  First, as shown in FIG. 5 (a), a concrete hole 10 having a predetermined depth is formed by drilling using a drilling machine at a predetermined position of the existing concrete.

  Next, as shown in FIG. 1, the extension member 5 whose length is adjusted according to the depth of the concrete hole 10 is attached to the rotating shaft 8 of the motor M, and the cutting tool 1 is attached to the lower end surface thereof.

  Next, the cutting tool 1 is inserted to the vicinity of the deepest portion of the concrete hole 10.

  Next, as shown in FIG. 5B, the motor M is driven to rotate the rotating shaft 8. By this rotation, the cutting tool 1 rotates, and the cutting piece 18a comes into contact with the inner wall surface of the concrete hole 10 by the pressing force of the spring portion 15, and sequentially cuts grooves of a certain depth in the circumferential direction. The vibration generated by the rotation is absorbed by the spring portion 15, so that the motor or the like hardly vibrates, and it is possible to prevent the motor from being broken due to vibration or the like, and noise is also suppressed.

  Further, since the spring portion 15 is bent only in a certain direction by the regulating body, the position of the cutting portion 18 is stabilized, and a groove having a uniform shape is formed on the inner wall surface of the concrete hole 10.

  Next, as shown in FIG. 5C, the operating lever 4 is operated to raise the motor M to a predetermined height, drive the motor M, and sequentially cut the grooves 30 in the upper inner wall surface. In this way, the plurality of grooves 30 can be cut in the inner wall surface of the concrete hole 10 in the vertical direction of the concrete hole 10.

  Next, as shown in FIG. 5 (d), an anchor (rebar) 35 is inserted into the concrete hole 10, and a grout material 36 (non-shrink mortar, epoxy resin or the like) is injected into the concrete hole 10 to fix the anchor. Finish the work.

  As described above, according to the present embodiment, a plurality of grooves 30 having a certain depth are formed on the inner wall surface of the concrete hole 10 by a simple operation. Therefore, the grooves 30 serve as shear keys, and the grout material 36 and the concrete are formed. The adhesion force of can be increased. As a result, the anchor 35 fixing length (concrete hole depth) can be shortened compared to the conventional case, and the work of avoiding the reinforcing bars arranged in the existing concrete during drilling becomes easy. The workability (workability) of the reinforcement work can be improved.

  In addition, this application is not limited to this embodiment, It can implement in a various form. For example, in this embodiment, each member is connected by screwing. However, the present invention is not limited to screwing, and a generally used fitting structure or the like can be used as appropriate.

DESCRIPTION OF SYMBOLS 1 Cutting tool 8 Rotating shaft 10 Concrete hole 11 Base 14 Bending part 15 Spring part 17 Connection body 18 Cutting part 18a Cutting blade 25 Control body 25a Through-hole 30 Groove

Claims (5)

A cutting device for cutting a groove in the inner wall surface of a hole formed in existing concrete,
A base connected to the rotating shaft of the drive and inserted into the hole;
A bent portion that extends vertically downward from the lower end surface of the base portion and is bent in the middle thereof; and
A spring portion attached to the lower end surface of the bent portion;
A cutting part fixed to the lower end surface of the spring part via a connecting body, and a cutting blade attached to the periphery;
A cutting apparatus comprising:   The cutting device according to claim 1, wherein a restriction body that extends in a vertical direction on both sides of the spring portion and restricts a bending direction is attached to the base portion.   The cutting device according to claim 1 or 2, wherein the base portion, the bent portion, the spring portion, and the cutting portion are detachably connected to each other. At least the base and the inside of the bent part are formed with a flow path through which water can pass,
The cutting device according to claim 2 or 3, wherein a hole for guiding water that has passed through the flow path to the inner wall surface of the hole is formed in the regulating body. A base connected to the rotating shaft of the drive unit and inserted into a hole formed in the existing concrete; a bent portion extending vertically downward from the lower end surface of the base; The hole using a cutting device comprising: a spring portion attached to the lower end surface of the bent portion; and a cutting portion fixed to the lower end surface of the spring portion via a connecting member and having a cutting blade attached to the periphery. An anchor fixing method in which a groove is cut in the inner wall surface and the anchor is fixed in this hole,
A drilling step of drilling the concrete;
A cutting blade insertion step of inserting the cutting blade of the cutting device into a hole formed by a hole;
In the vertical direction of the hole, a groove forming step of forming a plurality of grooves on the inner wall surface of the hole formed in the concrete by the cutting blade;
An anchor fixing step of inserting an anchor into the hole and injecting a grout material;
An anchor fixing method characterized by comprising:

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