JP2005320701A - Support base and support structure for fixing and supporting aboveground installation column on ground - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support base for an aboveground installation column uncollapsible even when impact is applied to the column by reducing a welding place with the column. <P>SOLUTION: This support base 4 for fixing and supporting the aboveground installation column on the ground, has an aboveground installation part to be fixed on the ground, and a column fixing part for welding and fixing a lower end part of the column and positioned above the aboveground installation part, and has a shape of gradually reducing in an outside diametrical dimension over the column fixing part from the aboveground installation part. The aboveground installation part forms a spot facing part 4c for storing a head part of a fixing bolt 7. The aboveground installation part, the column fixing part, and the spot facing part are integrally manufactured by forging. The support base desirably has a shape of gradually reducing even in an inside diametrical dimension over the column fixing part from the aboveground installation part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a support base and a support structure for fixing and supporting a ground installation column on the ground.

  A support structure as shown in FIG. 7 is well known as a support base for fixing a ground installation support such as a street light, an illumination light, a road sign, and a flag pole to the ground. As shown in FIG. 7, a square base plate 20 is provided at the lower end of the support column 2, and as shown in FIG. 7B, four rib plates 21 having a triangular side shape are provided. The base plate 20 is fixed on the ground with bolts 30. The base plate 20 and the column 2 are coupled by welding, and the rib plate 21 and the side surface of the column 2 and the lower surface of the rib plate 21 and the upper surface of the base plate 20 are also coupled by welding.

  The weld toe portion of the rib plate 21 is a portion with high stress concentration, and is a weak point against metal fatigue. Moreover, since the base plate 20, the rib plate 21, and the support | pillar 2 are couple | bonded by welding, a welding location increases, As a result, welding work takes time and becomes complicated. In addition, since the cross-sectional shape suddenly changes from the support 2 to the weld toe of the rib plate, there is a risk that when the car collides with the support 2, a crack will enter from there and in some cases the support 2 may collapse. It was. Further, the rib plate 21 and the head of the bolt 30 cause a pedestrian or the like to trip, and there is room for improvement in terms of safety.

FIG. 8 is a diagram showing another known technique. In this support structure, the thickness of the base plate 22 is increased, the rib plate is eliminated, and the support column 2 is welded and fixed. Further, a counterbore is formed on the base plate 22 so that the head of the bolt 30 does not jump out (for example, see Patent Document 1 below). However, even in this structure, the cross-sectional shape changes abruptly, so that there is still a problem that cracks easily occur. By forming the counterbore, the head of the bolt 30 is prevented from protruding. However, if the counterbore process is performed by a machine lathe, the internal structure of the metal is sheared, so that cracks are likely to be generated therefrom. Another problem arises.
JP 2003-343119 A

  It is to provide a support base for a ground-installed support column that is less likely to collapse even when an impact is applied to the support column, while reducing the number of welding points with the support column.

In order to solve the above problems, the support base according to the present invention is:
A ground installation section for fixing to the ground;
In order to weld and fix the lower end of the support column, it is provided with a support column fixing unit located above the ground installation unit,
From the ground installation part to the column fixing part, it has a shape that the outer diameter dimension gradually decreases,
The ground installation part is formed with a counterbore part for accommodating the head of the fixing bolt,
The ground installation portion, the column fixing portion, and the spot facing portion are integrally manufactured by forging.

  The operation and effect of the support base with this configuration will be described. The support base includes a column fixing unit and a ground installation unit. The ground installation unit is installed on the ground, and the column fixing unit is fixed to the column. And it sets so that an outer diameter dimension may become small gradually from a ground installation part to a support | pillar fixing | fixed part. Thereby, the shape is determined so that a sudden change in the cross-sectional shape does not occur. Moreover, the reinforcing effect which the conventional rib plate was equipped with can be acquired in the part from which this outer diameter dimension changes gradually. Further, the ground installation portion is provided with a counterbore portion, and can accommodate the head of the fixing bolt. This can prevent the head from protruding. The support base according to the present invention is manufactured by forging. By manufacturing by forging, the internal structure of the metal becomes dense and uniform, and the tensile strength and mechanical strength are improved. The counterbore part is also formed by forging, so that the internal structure of the metal is not weakened. As a result, it is possible to provide a support base for the ground-installed support column that is less likely to collapse even when an impact is applied to the support column while reducing the number of welded portions with the support column.

  In the present invention, it is preferable that the inner diameter dimension is gradually reduced from the ground installation part to the column fixing part. With this configuration, it is possible to prevent an abrupt change in the cross-sectional shape on the inner surface side.

In order to solve the above problems, a support structure for fixing a support base according to the present invention to the ground is as follows:
An anchor bolt buried in the ground, and a high nut screwed into a male screw formed on the upper part of the anchor bolt,
The support base is fixed by screwing the fixing bolt inserted through the counterbore part into the high nut.

  In the conventional support structure, a W nut is screwed and fixed to the upper end of an anchor bolt installed on the foundation. However, such a W nut has a large protruding amount from the surface, and a pedestrian's trip etc. Cause. Further, in order to prevent the protrusion of the W nut, it is necessary to increase the depth of the counterbore part, which makes it difficult to manufacture by forging. Moreover, if the counterbore part is deepened, the strength of the support base is reduced. Therefore, if a high nut is screwed onto the upper portion of the anchor bolt and a fixing bolt for fixing the support base is screwed to the high nut, there is no need to use a W nut, and a seat It is not necessary to increase the depth of the bore. Therefore, the counterbore can be formed by forging while maintaining the strength of the support base.

  A preferred embodiment of a support base according to the present invention will be described with reference to the drawings. FIG. 1 shows a column 2 of a street lamp 1 (illumination lamp) as an example of a column for ground installation. An electric lamp 3 is attached to the tip of the support 2, and the lower end of the support 2 is installed and fixed on the ground G by the support base 4. The ground G is a road, a sidewalk, a street, a park, a plaza, and the like, and the present invention is not limited to a specific place.

<First Embodiment>
2 and 3 show the structure of the support base according to the first embodiment. FIG. 2 (a) is a longitudinal sectional view, FIG. 2 (b) is an AA arrow view of FIG. 3, and FIG. FIG. (B) is a bottom view. The support base 4 is composed of a single part and has a flat surface portion 4a and a slope portion 4b. Since the back surface of the flat surface portion 4a is fixed in contact with the ground G, the flat surface portion 4a functions as a ground installation portion. The planar portion 4a is formed in a disk shape in plan view, and four counterbore 4c are formed at equal intervals along the circumferential direction. Each counterbore 4c is formed with a through hole 4d, and a fixing bolt 7 is inserted therein. The depth of the recess of the counterbore 4c is preferably set so that the head of the fixing bolt 7 does not protrude from the surface of the flat portion 4a (or even if it protrudes, the amount is very small).

  The slope portion 4b is formed so that the outer diameter dimension decreases as it goes upward. The slope 4b has a substantially truncated cone shape. The upper end portion of the slope portion 4b is in contact with the lower end portion 2a of the support column 2, and this contact portion corresponds to the support column fixing portion. The upper region Y1 (front surface side) and the lower region Y2 (back surface side) of the portion in contact with the support column 2 are locations where welding is performed. The upper region Y1 is a ring-shaped region in plan view, and the lower region Y2 is also a ring-shaped region in bottom view. Since there are two welding locations, the number of welding locations can be considerably reduced as compared with the prior art FIG.

  As described above, since the shape is set so that the outer diameter dimension gradually decreases from the ground installation part to the column fixing part (from the lower side to the upper side), stress concentration can be reduced. Further, as can be seen from the cross-sectional view of FIG. 2, the inner diameter dimension is also set to be gradually reduced. Also in this point, stress concentration can be relaxed. Further, the slope portion 4b is set so as to gradually become thinner as the cross-sectional thickness goes upward. In addition, each corner of the support base 4 is chamfered (R-shaped) so that stress concentration does not occur. Thereby, even when a vehicle or the like collides with the support column 2 and an impact is applied, the support column 2 can be prevented from collapsing.

  Since the entire shape of the support base 4 according to the present invention including the counterbore 4c is manufactured by forging, the internal structure can be made uniform. Accordingly, the tensile strength and mechanical strength can be improved. As the material of the support base in the case of manufacturing by forging, a general structural rolled steel material is preferable, and SS400 is most preferable. Moreover, when surface-treating, hot dip galvanization is preferable.

  Next, the support structure of the support base 4 will be described. As shown in FIG. 2, four anchor bolts 5 are embedded in the underground, and the anchor bolts 5 are connected and held by a steel strip 9. A male screw 5 a is formed on the upper part of the anchor bolt 5. A high nut 7 that is screwed onto the male screw 5 a is provided, and an upper end portion of the high nut 6 is located on the lower surface of the support base 4. Then, the fixing bolt 7 is screwed into the female screw of the high nut 6 through the counterbore 4c and the through hole 4d. The fixing bolt 7 is coupled in a state in which the washer 8 is interposed between the head of the bolt and the bottom of the counterbore 4c. According to such a configuration, the depth of the counterbore 4c may be set to a depth that allows the head of the fixing bolt 7 to be accommodated.

Second Embodiment
4 and 5 show the structure of the support base according to the second embodiment. FIG. 4 (a) is a longitudinal sectional view, FIG. 5 (b) is an AA arrow view of FIG. 5, and FIG. FIG. (B) is a bottom view. The same number is attached | subjected to the location which performs the same function as 1st Embodiment. A description will be given centering on differences from the first embodiment.

  The support base 4 includes a flat surface portion 4a and a slope portion 4b, and the thickness of the slope portion 4b is substantially equal regardless of the location. As shown in FIG. 5, the shape of the flat surface portion 4 a is not circular in plan view, but an arc-shaped recess indicated by a drawing number 4 e is formed with respect to the circular shape. Even in such a configuration, the outer diameter and the inner diameter are gradually reduced, and the stress concentration can be reduced. Thus, the shape of the plane part 4a can be variously modified.

<Third Embodiment>
FIG. 6 shows a structure of a support base according to the third embodiment. In both the first and second embodiments, the outer diameter and the inner diameter are gradually reduced, but the change is discontinuous at the boundary between the flat surface portion 4a and the slope portion 4b. In the example of FIG. 6, the outer diameter shape changes continuously and gently. The support base 4 as a whole has a substantially truncated cone shape. In addition, the outer diameter line from the ground installation part to the column fixing part is a concave curve in FIG. Such a configuration is also included in the present invention.

<Another embodiment>
The illumination lamp (street lamp) is not limited to the structure of the present embodiment, and the present invention can be applied to various types of illumination lamps. Moreover, it is applicable also when supporting support | pillars other than an illumination lamp.

The figure which shows the external structure of a street light The longitudinal cross-sectional view which shows the structure of the support base which concerns on 1st Embodiment. The top view and bottom view which show the structure of the support base which concerns on 1st Embodiment. The longitudinal cross-sectional view which shows the structure of the support base which concerns on 2nd Embodiment. The top view and bottom view which show the structure of the support base which concerns on 2nd Embodiment. The longitudinal cross-sectional view which shows the structure of the support base which concerns on 3rd Embodiment It is a figure which shows the support base which concerns on a prior art, (a) is a top view (b) is a side view. It is a figure which shows the support base which concerns on another prior art, (a) is a top view (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Street light 2 Support | pillar 2a Lower end part 4 Support base 4a Plane part 4b Slope part 4c Counterbore part 4d Through hole 5 Anchor bolt 5a Male thread part 6 High nut 7 Fixing bolt Y1 Upper area Y2 Lower area

Claims (3)

A support base for fixedly supporting the ground installation support on the ground,
A ground installation section for fixing to the ground;
In order to weld and fix the lower end of the support column, it is provided with a support column fixing unit located above the ground installation unit,
From the ground installation part to the column fixing part, it has a shape that the outer diameter dimension gradually decreases,
The ground installation part is formed with a counterbore part for accommodating the head of the fixing bolt,
A support base, wherein the ground installation portion, the column fixing portion, and the counterbore portion are integrally manufactured by forging.   2. The support base according to claim 1, wherein the support base has a shape such that the inner diameter dimension gradually decreases from the ground installation part to the column fixing part. A support structure for fixing the support base according to claim 1 or 2 to the ground,
An anchor bolt buried in the ground, and a high nut screwed to a male screw formed on the upper part of the anchor bolt,
A support base support structure, wherein the support base is fixed by screwing the fixing bolt inserted through a counterbore portion into the high nut.

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