JPH0674227A - Anchor bolt washer - Google Patents

Abstract

PURPOSE:To prevent the side slipping of a base plate, by overlappingly constituting, rotatably in right and left, two large and small disklike upper and lower washers having through holes, in which the lower surfaces are protrudedly formed and which are decentered from a center, in the washers for a steel frame, etc. CONSTITUTION:The lower side washer 1 having a large diameter and a roundness state, and the upper side washer 5 having a small diameter, are formed, and protruded parts 2 and 6 are provided respectively on the lower surface of both the washers 1 and 5. An anchor bolt 10 is drilleingly mounted in through holes 3 and 7 for putting into, while decentered from a center. The through hole 3 of the lower side washer 1 is made to fit to the outer diameter part 6a of the protruded part 6 of the upper side washer 5, and the through hole 7 of the upper side washer 5 is made to coincide with the diameter of the anchor bolt 10. In this constitution, the protruded part 6 of the upper side washer 5 is engaged with the through hole 3 of the lower side washer 1 to be overlapped by both the washers 5 and 1, the protruded part 2 of the lower side washer 1 is engaged with the hole 12 of a base plate 11 to be mounted, and the anchor bolt 10 is put into the through hole 7 to be engaged by a plain washer 15 and a nut 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washer for an anchor bolt used when constructing a steel frame or a steel frame concrete structure such as a bridge.

[0002]

2. Description of the Related Art In constructing a building such as a steel frame or a steel concrete structure, a work of attaching a bottom plate to be attached to the bottom of a steel column, that is, a base plate to an anchor bolt embedded in advance has been conventionally performed by the method shown in FIG. There is.

That is, the hole 12 of the base plate 11 is inserted into the embedded anchor bolt 10, a washer 13 is placed on the upper surface thereof, and the nut 14 and the flat washer 15 are tightened and fixed.

[0004]

The embedding of the anchor bolt 10 as described above causes a misalignment when first struck and causes a problem that it does not align with the hole 12 of the base plate 11 when the base plate 11 is installed.

Therefore, at the time of installing the base plate, an anchor bolt was put in the hole of the base plate and then concrete was poured. This method has a drawback that the construction period cannot be shortened because it takes time for the concrete of the anchor bolt to set.

Further, in the case of the anchor bolt pre-strike, the hole of the base plate is enlarged so that the core may be displaced, and the anchor plate is stopped by a large thick washer. In this case, the lateral force applied to the base plate is supported by the frictional force between the base plate and the foundation, which is generated by the tightening force of the bolts, so that the lateral force cannot be sufficiently supported, and the base plate may cause side slip.

The present invention is intended to solve the above-mentioned drawbacks of the base plate by forming a large insertion hole so as to fit even if the position of the anchor bolt that has been pre-filled is displaced from the core.

[0008]

According to the present invention, two large and small disc-shaped upper and lower washers each having a projection formed on the lower surface and having a through hole eccentric from the center are provided on the left and right sides. An anchor bolt washer that is rotatably superposed and is formed so that the outer peripheral edge of the upper washer is located within the outer peripheral edge of the lower washer when the upper washer superposed on the upper surface of the lower washer is rotated. That is what I did.

[0009]

[Operation] When mounting the base plate on the embedded anchor bolt and tightening it with a washer and a nut, the inner hole will be offset from the center of the washer no matter what position the anchor bolt is in. Even if the anchor bolt position is greatly displaced with respect to the large hole in the base plate by using two washers, one large and one small, with protrusions on the bottom, combined vertically,
It can be attached by rotating the upper and lower washers to the left and right.

Moreover, the lateral force applied to the base plate can be transmitted to the anchor bolt through the protruding portion of the washer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a washer for an anchor bolt of the present invention will be described with reference to the drawings. FIG. 2 is a plan view and a vertical sectional view of two large and small washers. A large-diameter true circular lower washer 1 and a small-diameter upper washer 5 are formed. 6 is provided. In addition, the anchor bolt 10 is provided with through holes 3 and 7 for inserting the anchor bolt 10 eccentrically from the center of both washers. The through hole 3 of the lower washer 1 has a shape that matches the outer diameter portion 6a of the protrusion 6 of the washer 5, and the through hole 7 of the upper washer 5 has a size that matches the diameter of the anchor bolt 10.

When the upper and lower washers thus formed are overlapped with each other, the protrusion 6 of the upper washer 5 is fitted into the through hole 3 of the lower washer to form the washer for the anchor bolt. Lower washer 1
The outer diameter end 4 of the protrusion 2 is formed to have a size that fits into the hole 12 of the base plate.

Further, the upper washer 5 and the lower washer 1 will be described. The wall thickness between the outer diameter φd of the protrusion 6 of the upper washer 5 and the hole diameter φa of the through hole 7 matched with the outer diameter of the anchor bolt 10 will be described. n, the wall thickness with the hole diameter φ of the through hole 3 of the protrusion 2 of the lower washer 1 is m, and the hole diameter φb of the base plate 11 that requires tightening, the protrusion of the lower washer 1 The outer diameter 2a of 2 is adjusted to this hole diameter φb. Then, the diameter of the through hole inside the lower washer 1 is set to Formula 1, and a hole is formed at a distance of Formula 2 from the center of the washer.

[0014]

[Equation 1]

[0015]

[Equation 2]

The outer diameter of the protrusion 6 of the upper washer 5 is given by
Then, the through hole φa on the lower inner side is bored at a distance of Formula 4 from the center of the washer.

[0017]

[Equation 3]

[0018]

[Equation 4]

Washers 1.5 of large and small sizes constructed as described above
By placing them together on the base plate 11 and rotating the washers one turn left and right, that is, by rotating the washers left and right as shown in FIG. It can be installed even if the bolt is largely misaligned. Moreover, the lateral force applied to the base plate is directly transmitted to the anchor bolt via the protrusion of the washer unless the washer rotates.

Further, the rotational force of the washer due to the lateral force depends on the eccentric amount of the washer hole, but since the eccentric amount is generally small, the frictional force of the washer due to the tightening force of the nut 13 suppresses this rotational force. However, if a larger force is applied and the washer may rotate, the protrusions of both washers are processed into a taper, and the nut is tightened so that this part fits into the mating hole in a wedge shape. You may.

[0021]

Since the present invention is configured as described above, even if the hole of the base plate is made large, it is equivalent to that the hole of the base plate has the same hole diameter as the bolt diameter, so that the anchor bolt can be pre-strike. Moreover, the lateral force applied to the base plate can be transmitted to the anchor bolt through the side surface contact portion of the protrusion of the washer.

[Brief description of drawings]

 The figure shows an embodiment of the invention.

FIG. 1 is a sectional view showing a usage state of a washer of the present invention.

FIG. 2 is a plan view and a vertical sectional view of a washer of the present invention.

FIG. 3 is a diagram showing a rotating state of a washer of the present invention.

FIG. 4 is a cross-sectional view showing a usage state of a conventional washer.

[Explanation of symbols]

 1 Lower Washer 2 Projection 3 Through Hole 4 Outer Edge of Washer 5 Upper Washer 6 Projection 7 Through Hole 8 Outer Edge of Washer 10 Anchor Bolt 11 Base Plate 12 Base Plate Hole 13 Washer 14 Nut 15 Flat Washer a Upper Washer Projection Inner diameter b Outer diameter of lower washer protrusion m Wall thickness between lower washer protrusion and inner hole n Wall thickness between upper washer and inner hole

Claims (2)

[Claims] 1. The upper and lower disc-shaped washers, large and small, having a lower surface formed in a convex shape and having a through hole eccentric from the center, are superposed so as to be rotatable left and right. Washer for anchor bolt. 2. When the upper washer of the small disc superposed on the upper surface of the lower washer of the large disc is rotated to the left or right, the outer peripheral edge of the upper washer is located within the outer peripheral edge of the lower washer. The washer for anchor bolt according to claim 1, wherein the upper washer is formed as described above.