JP2007120705A - Expansion anchor plug and construction method using screw anchor having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely guide a self-entering screw in a penetration hole 2 at an appropriate attitude, in an expansion-type anchor plug 1 of an almost cylindrical shape mode of a synthetic resin. <P>SOLUTION: The anchor plug 1 comprises a plug neck 3 located at the upper part, a plug leg 5 located at the lower part, and an expansion sleeve 4 located therebetween, all of which are integrally and continuously constructed. A pair of slits 6, 6 are formed at the outer periphery of the anchor plug 1 to permit the expansion sleeve 4 to be expanded outward in the radial direction by screwing a tapping screw. On the inner diameter of the plug neck 3, a spirally stepped portion 15 is formed for gripping the self-entering screw at its front end in a screwable manner and holding the self-entering screw in a concentric shape. The outer periphery of the thread of the self-entering screw and the advance side flank surface thereof abut on the spirally stepped portion 15. Thereby, the self-entering screw is held to the anchor plug 1 in a proper attitude at the initial stage of screwing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an expandable anchor plug for fixing a self-penetrating screw to a pilot hole opened in a construction site made of a hard and brittle material such as a general concrete wall or block, and the self-penetrating screw, It is related with the construction method which fixes a workpiece | work to the surface of a construction place using the screwed-type anchor which combined.

  Conventionally, in order to fix a work such as heat insulating material to a construction site such as a concrete wall, a screw-in type anchor made of a synthetic resin and combined with a substantially cylindrical expandable anchor plug and a self-advancing screw has been used. Yes.

  Patent Document 1 discloses an example of an expandable anchor plug used for this type of screw-type anchor. The expandable anchor plug of Patent Document 1 includes a plug neck portion positioned on the front side when viewed from the insertion direction of the self-entry screw, a plug leg portion positioned on the front side when viewed from the insertion direction, and a gap between the two. It has a structure in which the positioned expansion sleeve portion is integrally connected. A pair of thin portions that can be deformed in the circumferential direction by screwing of self-advancing screws are formed at locations facing each other across the through hole in the expansion sleeve portion.

  The inner diameter of the through hole is gradually reduced from the plug neck to the plug leg (step 3). The portion of the plug neck in the through hole has a tapered shape that is tapered at a gentle angle in order to guide the tip of the screw portion of the self-advancing screw in an appropriate posture with respect to the through hole. .

  When using this expandable anchor plug, after drilling a pilot hole at a construction site with a drill or the like, the expandable anchor plug is inserted into the pilot hole with the plug legs first. Next, the self-penetrating screw penetrating the work is screwed into the expandable anchor plug with a power driver or the like so that the work overlaps the surface of the construction site.

Then, since the inner diameter of the expansion sleeve portion of the through hole is smaller than the nominal diameter of the self-advancing screw, as the self-advancing screw is screwed, both thin portions of the expansion sleeve portion expand in the circumferential direction, The expansion sleeve portion is pushed outward in the radial direction and is in close contact with the inner wall of the prepared hole. As a result, the expandable anchor plug cannot be removed from the pilot hole, and the work is pressed and fixed to the surface of the construction site by the head of the self-advancing screw screwed into the expandable anchor plug.
Special table 2003-529727 gazette

  As a self-advancing screw screwed into the expandable anchor plug of Patent Document 1, usually a wood screw is used, and the tip of the wood screw is located at the plug neck portion of the through hole of the expandable anchor plug that hits the insertion port. It is formed in a tapered shape so as to be guided (guided) in an appropriate posture to the through hole. On the other hand, if the thread lead (the amount of penetration in the axial direction with respect to one rotation of the screw) is made large (rough) to the extent that the bottom of the thread is exposed, the screwing speed increases and workability is improved. When the adhesive is used together, the adhesive enters between the threads and meshes with each other, and the fixing strength for fixing the expandable anchor plug and the self-advancing screw to the pilot hole is increased.

  However, if the thread lead of the self-advancing screw is large, the self-advancing screw is not sufficiently guided, and the self-advancing screw is screwed in an inclined state with respect to the axis of the expandable anchor plug. There was sometimes.

  As a result, the distal end of the shaft portion breaks through the thin wall portion of the expansion sleeve portion, for example, and the expansion of the expansion sleeve portion is insufficient in the outward radial direction. The fixing strength could not be secured, and as a result, the problem that the mounting strength of the workpiece was reduced occurred.

  Therefore, the present invention has a technical problem to provide an expandable anchor plug that can improve the current situation and a construction method using the same.

  In order to solve this technical problem, the invention of claim 1 is a substantially cylinder that is inserted into a pilot hole opened in a construction place such as a concrete wall and expanded so as to expand radially outward by screwing of a self-advancing screw. The self-advancing screw has a tip that is screwable so as to be screwed into a portion of the inner diameter portion on the front side when viewed from the insertion direction of the self-advancing screw. Guide means for concentrically holding the entry type screw is provided.

  According to a second aspect of the present invention, in the expandable anchor plug according to the first aspect, the expandable anchor plug is made of a synthetic resin and is located on the front side when viewed from the insertion direction of the self-advancing screw. And a plug leg portion located on the front side when viewed from the insertion direction and an expansion sleeve portion located between both of them, and a slit is formed at least in the expansion sleeve portion. Thus, while the expansion sleeve portion is allowed to expand radially outward by screwing in the self-advancing screw, the guide means includes an outer periphery and an advancing side of the thread in the self-advancing screw. It is a spiral step portion that comes into contact with the flank surface, and is tapered so that the inner diameter becomes smaller in the insertion direction of the self-advancing screw.

  The present invention uses a screw-in type anchor in which the expandable anchor plug according to claim 1 or 2 and a self-advancing screw having a large lead so that the bottom of the thread portion is exposed, and the work is It also includes a construction method for fixing to the surface. In this construction method, as described in claim 3, before or after injecting the expandable anchor plug into the pilot hole opened at the construction site, the adhesive is injected into the pilot hole, and then the self-advancing screw is installed. The work is fixed to the surface of the construction site by screwing into the expandable anchor plug.

  The expandable anchor plug according to the present invention is such that the self-advancing screw is gripped so that the tip of the self-advancing screw can be screwed into a position on the near side as viewed from the insertion direction of the self-advancing screw in the inner diameter portion. Since the guide means for concentrically holding the screw is provided, it is easy to hold the tip of the self-advancing screw in an appropriate posture with respect to the inner diameter of the expandable anchor plug at the beginning of screwing. Yes. Due to the presence of the guide means, even if the thread lead is a large (coarse) self-advancing screw, the posture is parallel to the axis of the expandable anchor plug (straight posture with respect to the expandable anchor plug). Hold and screw straight.

  According to a second aspect of the present invention, the spiral stepped portion as the guide means is configured such that an outer periphery of a screw thread in the self-advancing screw and an advancing flank surface come into contact with each other, and the insertion of the self-advancing screw is performed. Since it has a tapered shape so that the inner diameter becomes smaller in the direction, there is an effect that when the expandable anchor plug is manufactured using a mold, molding becomes easy.

  According to the construction method of claim 3, before or after injecting the expandable anchor plug into the pilot hole opened in the construction site, the adhesive is injected into the pilot hole, and then the lead is so exposed that the valley bottom of the screw portion is exposed. Since the work is fixed to the surface of the construction site by screwing a large self-penetrating screw into the expandable anchor plug, the expansion action of the expandable anchor plug by screwing the self-penetrating screw, The adhesive action by the adhesive functions in a complementary manner, and the fixing strength of the expandable anchor plug and the self-advancing screw with respect to the pilot hole is sufficiently secured, and as a result The mounting strength can be improved.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings (FIGS. 1 to 4). 1A is a front view of the expandable anchor plug in the present embodiment, FIG. 1B is a right side view, FIG. 1C is a plan view, FIG. 1D is a bottom view, and FIG. Ie-Ie enlarged sectional view, FIG. 2A is a sectional view taken along IIa-IIa in FIG. 1C, FIG. 3B is an enlarged sectional view of the main part of FIG. 4 and 4 are explanatory views showing an example of the construction procedure.

(1). Configuration of Screw-in Anchor The screw-in anchor according to the present embodiment includes an expandable anchor plug 1 (see FIG. 1) made of synthetic resin and a self-advancing screw 21 (see FIG. 3).

  A self-advancing screw 21 to be screwed into the expandable anchor plug 1 is widely known conventionally, and includes a shaft portion 22 made of a metal round bar (or wire rod) such as steel or stainless steel. A substantially trapezoidal head 23 is formed at one end of the shaft 22. A screw portion 24 composed of a single thread 25 is formed in a certain range of the shaft portion 22 on the side opposite to the head portion 23. For this reason, the shaft portion 22 is divided into a screw portion 24 and a screwless portion 26. The lead L1 (which is also a pitch) of the screw thread 25 is set to a large (coarse) value so that the valley bottom is exposed. The tip of the screw portion 24 is sharp. The thread 25 of the threaded portion 24 is a right-hand thread as usual. Since the thread 25 is formed by rolling, the root diameter RD of the threaded portion 24 is smaller than the diameter DD of the unthreaded portion 26. A driving hole (not shown) for engaging the driver bit is formed on the top surface of the head 2.

  An expandable anchor plug 1 made of synthetic resin (hereinafter referred to as an anchor plug) has a through-hole 2 (FIGS. 1C and 1E) and FIG. 2 (a)) is formed in a substantially cylindrical shape penetrating in the axial direction. In the following description, for the sake of convenience, the front side as viewed from the insertion direction IN (see FIG. 4C) of the self-advancing screw 21 is referred to as an upper portion, and the front side is referred to as a lower portion.

  The anchor plug 1 has a structure in which a plug neck portion 3 positioned at an upper portion, a plug leg portion 5 positioned at a lower portion, and an expansion sleeve portion 4 positioned therebetween are integrally connected. A pair of slits 6, 6 extending from the midway part of the plug neck 3 to the lower end of the expansion sleeve part 4 are formed on the outer periphery of the anchor plug 1 so as to face each other with the through hole 2 interposed therebetween (FIG. 1 ( b)). Therefore, the lower half portion of the plug neck 3 and the expansion sleeve portion 4 are divided into two by these slits 6 and 6. Due to the presence of the slits 6 and 6, when the self-advancing screw 21 is screwed into the through hole 2, the expansion sleeve portion 4 divided into two is allowed to expand radially outward.

  Each slit 6 of the present embodiment is straight at the place of the plug neck 3, but zigzag at the place of the expansion sleeve 4. In addition, round holes 7 having a diameter slightly larger than the slit width are formed through both ends of each slit 6 in the axial direction. This round hole 7 is for preventing further tearing in the axial direction from each end of the slit 6 when the self-penetrating screw 21 is screwed into the through hole 2.

  In addition, the slit 6 should just exist in the expansion sleeve part 4 at least. Moreover, it may replace with the slit 6 and may employ | adopt the thin part which can deform | transform in the circumferential direction by screwing in of the self-advancing type screw 21.

  A plurality of anti-rotation claws 8 projecting radially outward are formed on the outer periphery of the plug neck 3 at appropriate intervals along the circumferential direction. In the present embodiment, four rotation prevention claws 8 that are long in the axial direction are arranged at 90 ° intervals on the outer periphery of the plug neck 3. The rotation preventing claw 8 extends in the axial direction from the upper end of the plug neck portion 3 to the vicinity of the midway portion.

  In the lower part of the outer periphery divided into two of the plug neck portions 3, rotation prevention tongues 9 are cut and raised, respectively. Each of the rotation preventing tongues 9 is curved so as to open toward the screwing direction SC (the clockwise direction in FIG. 1 (e)) of the self-advancing screw 21. The tip corner portion of the rotation preventing tongue piece 9 is inclined radially outward.

  These rotation prevention pawls 8 and rotation prevention tongues 9 come into contact with the inner wall of the lower hole 34 when the anchor plug 1 is inserted into a lower hole 34 (see FIG. 4) opened at a construction site by a drill or the like. . For this reason, the torsional moment applied to the anchor plug 1 when the self-advancing screw 21 is screwed into the through hole 2 is received by the rotation-preventing claw 8 and the rotation-preventing tongue piece 9, and the anchor plug 1 is engaged with the self-advancing screw 21. And preventing rotation. A thin ring-shaped flange 10 is formed on the upper end surface of the plug neck 3.

  A plurality of arc-shaped or annular concave grooves 11 are formed on the outer peripheral portion of the expansion sleeve portion 4 so as to be aligned at appropriate intervals in the axial direction. For this reason, between the concave grooves 11 adjacent to each other in the axial direction is an overhanging portion 12 projecting outward in the radial direction, and the outer shape of the expansion sleeve portion 4 has a plurality of upper and lower stages like sawtooth. Each of the overhanging portions 12 expands radially outward when the self-advancing screw 21 is screwed in, and comes into close contact with the inner wall of the pilot hole 34 to generate a frictional force with the inner wall. Due to the frictional force, the fixing strength of the anchor plug 1 with respect to the pilot hole 34 is ensured.

  A cross groove 13 is formed below the plug leg 5 so as to intersect the through hole 2 in the bottom view. Due to the cross groove 13, the lower half of the plug leg 5 is equally divided into four divided legs 14. These four split legs 14 are also spread radially outward so as to be separated from each other when the self-advancing screw 21 is screwed in and are brought into close contact with the inner wall of the pilot hole 34, and the pilot hole 34 is caused by frictional force due to the close contact. This contributes to an improvement in the fixing strength of the anchor plug 1 against. In addition, the lower end corner part by the side of the through-hole 2 among each division | segmentation leg 14 is chamfered.

  As shown in FIG. 2 (a), the through hole 2 (inner diameter portion) of the anchor plug 1 has a spiral step portion 15 as a guiding means at the plug neck portion 3, and an extension sleeve portion 4 to a plug leg portion 5. The first straight portion 16 extending to the upper half portion and the second straight portion 17 at the lower half portion of the plug leg portion 5 are successively extended.

  The spiral step portion 15 at the plug neck 3 protrudes radially inward with the same lead L2 as the lead L1 of the screw thread 25 in the self-advancing screw 21 and is formed in a spiral shape (FIG. 2A). ) (B)). When the self-advancing screw 21 is screwed, the tip of the screw part 24 is gripped so as to be screwed, and the self-advancing screw 21 is concentrically held by the spiral step part 15. In this case, the outer periphery of the screw thread 25 in the self-advancing screw 21 hits the inner surface of the spiral step portion 15, and the leading flank surface 25a of the screw thread 25 rests on the spiral surface 15a of the spiral step portion 15 ( Abut).

  In addition, the spiral step portion 15 has a maximum inner diameter (inner diameter of the insertion port in the through hole 2) that is equal to or larger than the nominal diameter ND of the self-advancing screw 21. As it approaches the first straight portion 16 at the location, it is tapered (toward the insertion direction IN of the self-advancing screw 21).

  The first and second straight portions 16 and 17 of the through hole 2 have an inner diameter smaller than the nominal diameter ND of the self-advancing screw 21. The inner diameter of the second straight portion 17 is smaller than that of the first straight portion 16. The reason why the inner diameters of the first and second straight portions 16 and 17 are made small in a stepwise manner (two steps) is that the expansion sleeve portion 4 and the plug leg portion 5 have four diameters when the self-advancing screw 21 is screwed. This is because the two split legs 14 are surely expanded radially outward.

(2). Construction Procedure Next, an example of a procedure for fixing the workpieces 32 and 33 to the concrete side wall 31 as a construction site using the anchor plug 1 and the self-advancing screw 21 will be described with reference to FIG.

  First, as shown in FIG. 4A, a pilot hole 34 is drilled in the concrete side wall 31 with a drill (not shown). The pilot hole 34 can be fitted with a slight deformation of the anchor plug 1, but is suitable as long as the anchor plug 1 fits tightly.

  Next, chips and dust accumulated in the prepared hole 7 are removed, and an appropriate amount of adhesive 36 is injected with an injection tool 35 with a nozzle, and then the anchor plug 1 is mounted with the plug leg 5 first. It inserts in the pilot hole 34 (refer FIG.4 (b)). In this case, the adhesive 36 only needs to be sufficient to fill the concave groove 11 of the expansion sleeve portion 4, for example, and does not necessarily need to be completely filled up to the gap between the anchor plug 1 and the pilot hole 34. Various adhesives such as a two-component mixed type composed of an epoxy resin and a curing agent can be used as the adhesive 36, for example. The adhesive 36 is not limited to the injection type, and a capsule type may be adopted. Needless to say, the adhesive 36 may be injected into the pilot hole 34 after the anchor plug 1 is inserted into the pilot hole 34.

  Next, the work 32, 33 overlaps the surface of the concrete side wall 31, and the self-penetrating screw 21 that penetrates the work 32, 33 is screwed into the through hole 2 of the anchor plug 1 by a power driver (not shown). (See FIG. 4 (c)).

  Then, at the initial stage of screwing, the tip portion of the self-advancing screw 21 is guided (guided) in the screwing direction SC in a state where the outer periphery of the screw thread 25 and the leading flank surface 25a are in contact with the spiral stepped portion 15. The self-advancing screw 21 can be easily held in an appropriate posture with respect to the through hole 2 of the anchor plug 1. Due to the presence of the spiral step portion 15, even if the lead L <b> 1 of the screw thread 25 is large (coarse), the self-advancing screw 21 has a posture parallel to the axis of the anchor plug 1 (a straight posture with respect to the anchor plug 1). ) And can be screwed straight into the pilot hole 34.

  The torsional moment applied to the anchor plug 1 during screwing is received by the anti-rotation claw 8 and the anti-rotation tongue 9 that are in contact with the inner wall of the pilot hole 34, and the anchor plug interlocked with the self-entry screw 21. The rotation of 1 is suppressed. Before screwing the self-advancing screw 21, the workpieces 32 and 33 are overlapped on the surface of the concrete side wall 31, and a hole for inserting the screw 21 is formed at a position corresponding to the pilot hole 34 in the workpieces 32 and 33. You may make it leave.

  When the screw part 24 of the self-advancing screw 21 reaches the first straight part 16, the inner diameter of the first straight part 16 is smaller than the nominal diameter ND of the self-advancing screw 21. The overhanging portion 12 is pushed outward and comes into close contact with the inner wall of the prepared hole 34.

  When the screwing is further advanced, the screw part 24 of the self-advancing screw 21 penetrates the plug leg part 5 while cutting the thread groove on the inner surface of the second straight part 17 and pulls the plug leg part 5 toward the expansion sleeve part 4 side. . This also contributes to the action of pushing the expansion sleeve portion 4 outward in the radial direction, and reinforces the action of bringing the overhanging portion 12 into close contact with the inner wall of the prepared hole 34. In this case, the group of divided legs 14 of the plug leg 5 is also pushed outward in the radial direction and closely contacts the inner wall of the prepared hole 34 (see FIG. 4D). The fixing strength of the plug 1 is improved.

  As a result, the anchor plug 1 and the self-entry screw 21 are secured to the pilot hole 34, and the anchor plug 1 and the self-advancing screw 21 cannot be removed from the pilot hole 34. Thus, the workpieces 32 and 33 are firmly pressed and fixed to the surface of the concrete side wall 31.

  On the other hand, the adhesive 36 in the pilot hole 34 fills between the concave grooves 11 of the expansion sleeve portion 4 and the thread 25 of the self-advancing screw 21 and hardens as time passes. The anchor plug 1 and the self-entering screw 21 are also fixed to the prepared hole 34 by the adhesive force of the adhesive 36. In this case, since the groove 11 and the thread 25 and the adhesive 36 are engaged with each other, the anchor plug 1 and the self-advancing screw 21 can be firmly fixed to the prepared hole 34 even with a small amount of the adhesive 36. .

  In this case, since the anchor plug 1 is secured to the pilot hole 34 by the expansion action of the anchor plug 1 by screwing the self-advancing screw 21, the work piece can be worked even if the adhesive 36 is not cured at the time of construction. 32, 33 can be attached and no curing period is required (no need to wait for the adhesive 36 to harden completely).

  Further, since the anchor plug 1 and the pilot hole 34 are fixed through the adhesive 36 in addition to the frictional force due to the close contact, the anchor plug 1 and the self-entry screw 21 are loosened and rattled due to vibration or the like, for example. It can withstand long-term use. Of course, even if there is a slight gap between the anchor plug 1 and the pilot hole 34, the self-advancing screw 21 does not generate a moment to fall down, and until the adhesive 36 hardens. The self-entry screw 21 can be held horizontally.

  That is, the expansion action of the anchor plug 1 by screwing the self-advancing screw 21 and the adhesion action by the adhesive 36 function in a complementary manner, and the anchoring strength of the anchor plug 1 and the self-advancing screw 21 to the pilot hole 34 is fixed. Is sufficiently secured, and as a result, the mounting strength of the workpieces 32 and 33 can be improved.

  Needless to say, the above-described screw-in type anchor (a combination of the anchor plug 1 and the self-advancing type screw 21) can obtain sufficient fixing strength without using the adhesive 36.

(3). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, the guiding means described in the claims is not limited to the spiral step portion 15 described above, and may be a spiral groove or a protrusion formed in the inner diameter portion of the through hole. The expandable anchor plug is preferably a synthetic resin from the viewpoint of ease of molding or the like, but may be made of other materials such as aluminum (metal) depending on circumstances. In addition, the configuration of each unit is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

(A) is a front view of an expandable anchor plug, (b) is a right side view, (c) is a plan view, (d) is a bottom view, and (e) is an Ie-Ie enlarged sectional view of (a). is there. (A) is the IIa-IIa sectional view taken on the line of FIG.1 (c), (b) is the principal part expanded sectional view of (a). It is a front view of a self-entry type screw. It is explanatory drawing which shows an example of an installation procedure, (a) is a sectional side view of the state which poured the adhesive agent into the prepared hole of a concrete wall, (b) is a sectional side view of the state which inserted the expandable anchor plug in the prepared hole (C) is a side sectional view of a state in which a self-advancing screw is screwed into an expandable anchor plug, and (d) is a side sectional view of a state in which a workpiece is fixed with a self-advancing screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Expandable anchor plug 2 Through-hole 3 Plug neck part 4 Expansion sleeve part 5 Plug leg part 6 Slit 15 Spiral step part 15a Spiral surface 21 Self-entry type screw 24 Screw part 25 Screw thread 25a Advance side flank surface 31 Concrete side wall 32, 33 Workpiece 34 Pilot hole 36 Adhesive L1 Thread lead L2 Spiral step lead

Claims (3)

It is a substantially cylindrical expandable anchor plug that is inserted into a pilot hole opened at a construction site such as a concrete wall and expanded so as to swell radially outward by screwing of a self-advancing screw,
A guide for holding the self-advancing screw concentrically by gripping the tip of the self-advancing screw at the front side of the inner diameter portion when viewed from the insertion direction of the self-advancing screw. Means are provided,
Expandable anchor plug. The expandable anchor plug is made of synthetic resin, a plug neck portion located on the front side when viewed from the insertion direction of the self-entry screw, a plug leg portion located on the front side when viewed from the insertion direction, and these It has a structure in which the expansion sleeve located between the two is integrally connected,
While forming a slit in at least the expansion sleeve portion, the expansion sleeve portion is allowed to expand radially outward by screwing in the self-advancing screw,
The guide means is a spiral step portion where the outer periphery of the thread in the self-advancing screw and the advancing flank face abut, and the guide means is tapered so that the inner diameter decreases in the insertion direction of the self-advancing screw. It ’s in a circle,
The expandable anchor plug according to claim 1. The work is fixed to the surface of the construction site using a screw-in type anchor in which the expandable anchor plug according to claim 1 or 2 and a self-advancing screw having a large lead so that a valley bottom of the thread portion is exposed are used. A construction method,
Before or after injecting the expandable anchor plug into the pilot hole opened at the construction site, the adhesive is injected into the pilot hole, and then the self-penetrating screw is screwed into the expandable anchor plug to thereby install the workpiece into the construction site. Fixed on the surface of the
Construction method using a screw-in type anchor.

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