JP5567929B2 - Anchor construction method and coarse bit - Google Patents

Description

  The present invention relates to a method for embedding anchor members such as anchor reinforcing bars and anchor bolts in existing concrete, and a coarse bit used in the method.

  As a method for embedding and fixing an anchor member in existing concrete (an anchor construction method), a method described in Japanese Patent Application Laid-Open No. 2000-141358 is known. The outline of this method will be described. First, a hole having a predetermined inner diameter and depth is drilled in the concrete using a core bit, the concrete block in the hole is removed, and then the core bit is used using a coarse bit. A rough surface is formed on the inner wall of the hole formed by the above. Then, the fixing agent is injected into the hole, the anchor member is inserted, and the fixing agent is cured in the hole.

JP 2000-141358 A Japanese Patent Laid-Open No. 3-182305 JP-A-3-294107 JP-A-5-318457 JP-A-6-306957

  The conventional anchor construction method as described above has the following problems. As shown in FIG. 3, the core bit 6 used in the first step is formed by intermittently arranging a carbide tip 8 attached with diamonds at the tip of a cylindrical body 7, and the tip side is made of concrete. By rotating the main body 7 while being pressed, a hole of a predetermined size can be drilled in the concrete.

  The carbide tip 8 of the core bit 6 is arranged in an annular shape (circumferentially) at the tip of the cylindrical main body 7, and the inside of the core bit 6 is hollow, so as shown in FIG. When digging toward the inside of the concrete 9, a circular groove 10 is formed and a columnar concrete block 11 remains inside (see FIG. 4 (2)).

  For a certain part of the cylindrical concrete block 11, for example, as shown in FIG. 4 (3), a metal rod 12 is inserted into the groove 10 to apply a force from the side, or It can be removed from the hole by inserting a long ridge into the hole and breaking it. However, it is difficult to remove the portion close to the bottom of the hole in the concrete block 11, and eventually the convex portion 13 as shown in FIG. 4 (4) remains at the bottom of the hole. become.

  In such a case, only the range from the surface of the concrete 9 to the apex of the convex portion 13 (depth dimension L in FIG. 4 (4)) is a range that can be effectively used as a hole for embedding the anchor member. That is, even if the core bit 6 is used to drill a hole in the concrete 9 to the position of the depth dimension M shown in FIG. 4 (4), it is only to a position shallower than that (position of the depth dimension L). It will not be available. Therefore, when the anchor member is to be embedded up to the position of a certain depth dimension x, the height dimension K of the convex portion 13 finally remaining at the bottom of the hole is taken into consideration, and only that much. There is a problem that it is necessary to dig deeper (to a depth of x + K).

  The present invention has been made in order to solve the above-described problems, and a coarse bit or the like that can easily remove a convex portion near the bottom of a hole, which has been difficult to remove in the past. The purpose is to provide.

In order to form a rough surface on the smooth inner wall of the hole formed by the core bit, the coarse bit according to the present invention has a tip portion radially outward from the outer peripheral surface of the main body having a size corresponding to the size of the hole. multiple addition to a plurality of hard tip which projects is attached, that the end surface of the main body, the tip portion is protruded in the axial direction of the body, Ru can be broken cutting convex portions remaining near the bottom of the hole It is characterized by the fact that a cemented carbide tip is attached. In addition, it is preferable that the outer peripheral surface of the main body is formed with a plurality of concave portions that are shaped inwardly.

In the anchor construction method according to the present invention, a hole having a predetermined inner diameter and depth is formed from the concrete surface toward the inside using a core bit in which a diamond tip or a carbide tip is intermittently arranged at the tip of a cylindrical body. A plurality of cylindrical concrete blocks that are drilled and remain in the concrete are removed to a certain extent, and the tips protrude radially outward from the outer peripheral surface of the main body having a size corresponding to the size of the hole. The inner wall surface of the hole is cut using a coarse bit to which a plurality of cemented carbide tips are attached to the front end surface of the main body. In addition to processing into a rough surface, the convex portion remaining near the bottom of the hole is scraped off, the small concrete pieces accumulated near the bottom of the hole are removed, an anchor member is inserted into the hole, and the fixing agent It is characterized in that filling.

  The coarse bit according to the present invention can easily remove the convex portion near the bottom of the hole, which has been difficult to remove conventionally, and the depth of the hole formed inside the concrete using the core bit. The dimensions can be used effectively. In addition, since the cutting of the convex portion can be performed simultaneously with the roughing process, it can be realized without increasing the number of processes.

FIG. 1 is a perspective view of a coarse bit 1 according to the first embodiment of the present invention. FIG. 2 is a plan view of the coarse bit 1 of FIG. FIG. 3 is a partially cutaway side view of the core bit 6 used in the anchor construction method according to the second embodiment of the present invention. FIG. 4 is an explanatory diagram of an anchor construction method according to the second embodiment of the present invention. FIG. 5 is an explanatory diagram of an anchor construction method according to the second embodiment of the present invention.

  Each embodiment of the “mesh bit” and “anchor construction method” of the present invention will be described below with reference to the accompanying drawings. First, “coarse bits” will be described as the first embodiment of the present invention. FIG. 1 is a perspective view of a coarse bit 1 according to the first embodiment of the present invention, and FIG. 2 is a plan view thereof. As shown in the figure, the coarse bit 1 includes a main body 2 having a cylindrical shape as a basic shape, and a cemented carbide chip 3a attached so that a tip portion protrudes radially outward from the outer peripheral surface of the main body 2, and The cemented carbide chip 3b is attached so that the tip portion protrudes from the tip surface of the main body 2 in the axial direction of the main body 2.

  These cemented carbide chips 3a and 3b are inserted into a mounting hole (not shown) having a predetermined depth formed in advance on the outer peripheral surface or the front end surface of the main body 2, and contact surfaces (mounting) It is fixed to the main body 2 by a fixing agent applied to the inner wall surface of the hole or the outer peripheral surface of the base end portion. Also, by performing build-up welding around the opening edge of the mounting hole of the main body 2 from the shoulder opening of the protruding tip of the carbide tips 3a, 3b to the outer peripheral surface or the front end surface of the main body 2 (meat The prime weld 4) and the carbide tips 3a and 3b are integrated and reinforced with respect to the outer peripheral surface or the front end surface of the main body 2. In addition, the outer peripheral surface of the main body 2 is formed with a concave portion 5 that is shaped to bend inward.

  In the present embodiment, a total of six cemented carbide tips 3 a protruding radially outward from the outer peripheral surface of the main body 2 are attached. More specifically, the three carbide tips 3a are arranged around the axis of the main body 2 at an angular interval of 120 °, and they are arranged in two stages in the axial direction of the main body 2. . Similarly to the cemented carbide chip 3a, three recesses 5 are formed around the axis of the main body 2 at an angular interval of 120 ° and are arranged alternately with the cemented carbide chips 3a. A total of three cemented carbide chips 3b having tip portions protruding from the tip surface of the main body 2 in the axial direction of the main body 2 are attached. Note that the number of the carbide chips 3a and 3b may be appropriately changed according to the size of the coarse bit 1 or the like. For example, four carbide chips 3b on the front end surface of the main body 2 may be attached.

  Next, an “anchor construction method” will be described as a second embodiment of the present invention. FIG. 3 is a side view of the core bit 6 used in the anchor construction method according to the second embodiment of the present invention, and FIGS. 4 and 5 are explanatory diagrams of the anchor construction method of the present embodiment.

  In the present embodiment, first, a hole having a predetermined inner diameter and depth is formed in the concrete 9 using the core bit 6 shown in FIG. 3 (see FIGS. 4 (1) and (2)). The carbide tip 8 (or diamond tip) of the core bit 6 is arranged in a ring shape (circumferentially) at the tip of the cylindrical main body 7, and the inside of the core bit 6 is hollow. As shown in 4 (1), when digging toward the inside of the concrete 9, a circular groove 10 is formed, and a columnar concrete block 11 remains inside (FIG. 4 (2)). reference).

  Next, as shown in FIG. 4 (3), a certain portion of the columnar concrete block 11 is inserted by inserting a metal rod 12 into the groove 10 to apply a force from the side, or A long ridge or the like is inserted into the hole and broken to remove it from the hole. And the convex-shaped part 13 (refer FIG. 4 (4)) remaining in the bottom vicinity of a hole is removed with the coarse bit 1 shown in FIG.

  The coarse bit 1 is originally for forming a rough surface on the inner wall of the hole formed by the core bit. More specifically, when a hole is drilled in the concrete with a core bit, the inner wall surface becomes smooth, but when the fixing agent for fixing the anchor member in this state is filled in the hole, A sufficient fixing force cannot be obtained with respect to the inner wall surface, and the slip-out load becomes extremely small. Therefore, after drilling the hole with the core bit, the coarse bit to which the carbide tip is attached so that the tip protrudes radially outward from the outer peripheral surface of the cylindrical body is made to enter the hole while rotating. A process (coarse roughing process) for machining a smooth inner wall surface into a rough surface has been conventionally performed so that the inner wall surface of the hole is roughly cut with a cemented carbide tip and sufficient fixing strength is obtained.

  As described above, the coarse bit is originally for processing the inner wall surface of the hole into a rough surface. Therefore, the conventional coarse bit has a cemented carbide tip only on the outer peripheral surface of the main body in contact with the inner wall surface of the hole. It is attached. On the other hand, in the coarse bit 1 shown in FIG. 1, the carbide chip 3 b is attached not only to the outer peripheral surface of the main body 2 but also to the distal end surface of the main body 2 as described above. Therefore, when this coarse bit 1 is rotated and entered into the hole, the inner wall surface of the hole can be processed into a rough surface as shown in FIG. 5 (1), and the convex portion remaining near the bottom of the hole. 13 can be scraped off.

  Further, as shown in FIGS. 1 and 2, the coarse bit 1 has a concave portion 5 formed on the outer peripheral surface of the main body 2, and therefore, by cutting the inner wall surface or the convex portion 13 of the hole, Even if small concrete pieces stay near the bottom, it is possible to secure a space for temporarily retracting them, and within the allowable limit, the small concrete pieces are projected without being removed from the hole. The cutting process of the shaped part 13 can be continued.

  When the inner wall surface of the hole is processed into a rough surface with the coarse bit 1 and the cutting of the convex portion 13 is completed, the coarse bit 1 is extracted from the hole, and the concrete pieces accumulated near the bottom are removed. Then, as shown in FIG. 5 (2), the anchor member 14 is inserted and the hole is filled with a fixing agent. Thereafter, when the fixing agent filled through a predetermined curing time is cured, the construction is completed.

  Thus, according to the anchor construction method of the present embodiment, the convex portion 13 near the bottom of the hole, which has been difficult to remove in the past, can be easily removed. The depth dimension of the hole formed in the concrete 9 can be used effectively. In addition, since the cutting of the convex portion 13 can be performed simultaneously with the roughing process, it can be realized without increasing the number of processes.

  In the present embodiment, the carbide tip 3a whose tip portion projects radially outward from the outer peripheral surface of the main body 2 and the carbide tip 3b whose tip portion projects in the axial direction of the main body 2 from the tip surface of the main body 2 are used. The method of simultaneously cutting the convex portion 13 and machining the inner wall surface of the hole using the coarse bit 1 having the above is described, but the tip portion protrudes radially outward from the outer peripheral surface of the main body. A main body that is in contact with the inner wall surface of the hole by omitting the hard chip and preparing a dedicated cutting bit (a dedicated bit for cutting the convex part at the bottom of the hole) that has a carbide chip only on the tip of the main body. After performing a coarse graining process using a conventional coarse bit in which a cemented carbide tip is attached only to the outer peripheral surface of the convex part 13, the convex portion 13 at the bottom of the hole is formed by a dedicated bit having a cemented carbide tip only on the tip surface of the main body. The cutting may be performed.

1: coarse bit,
2: Body,
3, 3a, 3b: Carbide tip,
4: Overlay weld,
5: recess,
6: Core bit,
7: Body
8: Carbide tip,
9: Concrete,
10: groove,
11: concrete block,
12: Metal rod
13: convex part,
14: Anchor member,
15: Fixing agent

Claims (3)

Using a core bit in which a plurality of cemented carbide chips or diamond chips are intermittently arranged at the tip of a cylindrical body, a hole having a predetermined inner diameter and depth is drilled from the surface of the concrete toward the inside,
Remove a certain portion of the cylindrical concrete lump remaining inside the concrete,
A plurality of cemented carbide tips with tip portions projecting radially outward from the outer peripheral surface of the main body having a size corresponding to the size of the hole are attached, and the tip portions are arranged on the front end surface of the main body in the axial direction of the main body. Using a coarse bit to which a plurality of protruding carbide tips are attached , the inner wall surface of the hole is cut into a rough surface, and the convex portion remaining near the bottom of the hole is scraped.
Remove the small pieces of concrete collected near the bottom of the hole,
An anchor construction method, wherein an anchor member is inserted into the hole and a fixing agent is filled. In order to form a rough surface on the smooth inner wall of the hole formed by the core bit, a plurality of cemented carbide tips whose tips protrude radially outward from the outer peripheral surface of the main body having a size corresponding to the size of the hole are attached. In the coarse bit given,
The front end surface of said body, and characterized in that the tip portion in the axial direction of the main body is projecting, a plurality of carbide inserts that can be broken cutting convex portions remaining near the bottom of the hole is attached Coarse bit to do. 3. The coarse bit according to claim 2 , wherein a plurality of concave portions having a shape that swells inward are formed on an outer peripheral surface of the main body.

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