JP2012012765A - Fixed bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixed bearing which has a low bearing height, has a compact whole shape, is capable of sufficiently obtaining demanded rotation performance for a bearing, is easy to maintain and is suitable for exchange.SOLUTION: The fixed bearing, which is installed between an upper structure 50 and a lower structure 51 for transmitting the load of the upper structure to the lower structure, includes an upper shoe 1 fixed to the upper structure 50 and provided with a recess 4 on the lower surface, a lower shoe 2 fixed to the lower structure 51 and provided with a projection 7 on the upper part to be fitted to the recess 4, and a highly load resistant rubber shoe 8 disposed between the bottom surface of the recess 4 and the upper surface of the projection 7 and forming an annular gap 15 with the inner periphery of the recess 4.

Description

  The present invention relates to a fixed bearing, and more particularly to a fixed bearing suitable for replacement of an existing bearing between upper and lower structures of a bridge.

  In recent years, for example, existing bridge supports installed in the Showa 30s have reached the end of their useful lives, and their replacement work is increasing. In the replacement work, if the bearing height of the new bearing is higher than that of the existing bearing, the construction will be troublesome because it will cause the substructure's concrete to be beaten. Accordingly, it is desired that the new support for replacement has a low support height and a compact overall structure so that the existing support height space can be easily replaced.

  As what satisfy | fills such conditions, the fixed support of patent document 1 can be mentioned, for example. This fixed support is similar to a sealed support plate support, in which a rubber plate is accommodated in a pot portion formed on the lower collar, and the rubber plate is sealed in the pot portion by a cylindrical portion formed on the upper collar. .

  However, the conventional one has a structure in which a horizontal force is taken with a shear key. In order to take a large horizontal force with this shear key, the screw length of the threaded portion to the lower arm must be increased and the screw diameter must be increased. For this reason, the plate thickness of the lower heel increases and the cost increases. In addition, since the structure is similar to a hermetic support plate support, a seal must be provided to prevent water, dust, and the like from entering the pot portion from above. For this reason, it cannot be said that maintainability is also good.

JP2007-291676

The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a fixed bearing suitable for replacement that has a low bearing height and is compact in overall shape, and that can sufficiently obtain the rotation required for the bearing and can be easily maintained. is there.

The present invention employs the following means in order to achieve the above object.
That is, this invention is a fixed bearing installed between the upper structure and the lower structure, for transmitting the load of the upper structure to the lower structure,
An upper collar fixed to the upper structure and having a recess on the lower surface;
A lower collar having a convex portion fixed to the lower structure and fitted into the concave portion at an upper portion;
A fixed bearing comprising: a high-load-resistant rubber rod that is disposed between a bottom surface of the concave portion and an upper surface of the convex portion and forms an annular gap between the inner periphery of the concave portion. .

  In the above-mentioned fixed support, natural rubber or urethane rubber can be used as the high load resistant rubber rod.

The rubber hook has a center hole, and the upper hook has a small diameter hole provided in order from the bottom surface side of the recess and a large diameter hole connected thereto.
An upper lifting force stopping member having a diameter smaller than that of the center hole is inserted into the central hole of the rubber rod and the small diameter hole of the upper flange, and the upper lifting force stopping member has a lower end fixed to the lower rod and an upper end portion. It is also possible to adopt a configuration in which the large-diameter portion formed in is accommodated in the large-diameter hole of the upper collar and engageable with the lower surface thereof.

  According to the present invention, since the rubber rod is of high load resistance and has a structure that can be rotated, the height can be lowered, and therefore the bearing height can be lowered. Further, the horizontal load acting on the upper structure is transmitted from the peripheral wall of the concave portion of the upper collar to the convex portion of the lower collar and then to the lower structure. That is, the movement restriction of the upper structure in all horizontal directions can be achieved by a compact structure in which the concave portion and the convex portion are fitted. Further, since the horizontal load is transmitted by fitting the concave portion and the convex portion, the diameter of the contact portion is increased and the contact area is increased. As a result, the bearing stress is reduced, so that the wear resistance is improved.

  Further, since a gap is formed on the outer periphery of the rubber rod, a sufficient rotation function is exhibited without hindering the vertical rotation of the upper rod. Furthermore, since the concave portion is provided on the upper side and faces downward, water or dust does not enter the support portion (rubber cage), and therefore, no seal or the like is required, and maintenance is easy. .

It is a front view which shows embodiment of the fixed support by this invention. It is AA arrow sectional drawing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the fixed support according to the present invention is fixed to an upper structure 1 that is fixed to an upper structure 50 that is a concrete or steel bridge girder, and to a lower structure 51 that is a bridge pier or an abutment. A lower arm 2 is provided.

  The upper collar 1 is made of steel and is made circular in this embodiment, but may be rectangular. A projection (key) 3 is provided at the center of the upper surface of the upper rod 1 to be inserted into the upper structure 50 and transmit shearing force. A recess 4 is provided on the lower surface of the upper collar 1. The peripheral wall 5 of the recess 4 is provided on the outer periphery of the upper collar 1, and therefore the upper collar 1 has a cylindrical shape with the upper end closed as a whole.

  The lower arm 2 is also made of steel, and is made rectangular in this embodiment. The lower collar 2 is provided with a plurality of anchor bolt insertion holes 6 on the outer periphery. The lower rod 2 is fixed to the lower structure 51 by an anchor bolt 22 inserted into the insertion hole 6 and a nut 23 screwed into the anchor bolt 22.

  A cylindrical convex portion 7 is provided at the center of the upper surface of the lower collar 2. The upper portion of the convex portion 7 is fitted into the concave portion 4, and a slight gap is provided between the outer periphery of the convex portion 7 and the inner periphery of the concave portion 4 so as not to inhibit the vertical rotation of the upper collar 1. Yes.

  Between the upper surface of the convex portion 7 and the bottom surface (inner upper surface) of the concave portion 4, a rubber hook 8 is provided. The rubber rod 8 is an annular shape having a hole 9 in the center, and is formed by sandwiching a rubber body 12 between an upper steel plate 10 and a lower steel plate 11 and bonding them by vulcanization or using an adhesive. . The rubber body 12 has high load resistance and is made of natural rubber or urethane rubber.

  An annular recess 13 is formed on the top surface of the projection 7, and a recess 14 is formed on the bottom surface of the recess 4. The lower steel plate 11 of the rubber bowl 8 is fitted in the annular recess 13 and the upper steel plate 10 is fitted in the recess 14. The outer diameter of the rubber rod 8 is smaller than the inner diameter of the recess 4, and therefore an annular gap 15 is formed between the outer periphery of the rubber rod 8 and the inner periphery of the recess 4.

  A screw hole 16 is provided in the center of the convex portion 7 of the lower collar 2, and a small diameter hole 17 and a large diameter hole 18 whose axial centers coincide with the screw hole 16 are formed on the upper collar 1 from the bottom surface side of the concave portion 4. It is provided in order. The large-diameter hole 18 opens on the upper surface of the protrusion 3. An upper lift stop bolt 19 constituting an upper lift stop member is inserted into the small diameter hole 17 and the center hole 9 of the rubber rod 8, and the lower end portion thereof is screwed and fixed to the screw hole 16.

  A bolt head 20 which is a large diameter portion of the upper lifting stop bolt 19 is accommodated in the large diameter hole 18 and can be engaged with a lower surface thereof. The bolt head 20 is provided with a gap between the inner peripheral surface and the lower surface of the large diameter hole 18 so as not to hinder the vertical rotation of the upper rod 1. The diameter of the upper lift stop bolt 19 is smaller than the inner diameter of the rubber rod 8 (the diameter of the center hole 9). Therefore, an annular gap 21 is formed between the upper lift stop bolt 19 and the inner periphery of the center hole 9. ing.

  In the fixed support, a vertical load acting on the upper structure 50 is transmitted to the lower structure 51 via the rubber rod 8. Since the rubber body 8 is made of urethane rubber and has a high load resistance, the rubber rod 8 can be lowered in height, and therefore the bearing height can be lowered. The horizontal load acting on the upper structure is transmitted from the peripheral wall 5 of the concave portion 4 to the convex portion 7 since the convex portion 7 of the lower collar 2 is fitted in the concave portion 4 of the upper collar 1, and the lower structure 51. Is transmitted to. That is, the movement of the upper structure 50 is restricted in all horizontal directions by a compact structure in which the concave portion 4 and the convex portion 7 are fitted.

  Moreover, although the vertical rotation of the upper structure 50 is absorbed by the deformation of the rubber rod 8, the gaps 15 and 21 are formed on the inner and outer circumferences of the rubber rod 8, so that the rotation of the upper rod 1 is obstructed. Fully function without rotation. Further, the upper lifting force acting on the upper structure can be received by the head 20 of the upper lifting stop bolt 19 engaged with the lower surface of the large-diameter hole 18.

  The fixed bearing has a very advantageous structure for maintenance. That is, the concave portion 4 and the convex portion 7 fitted to the concave portion 4 are provided on the upper rod 1 and the lower rod 2, respectively, and the concave portion 4 faces downward. There is nothing to do. Therefore, no seal or the like is required, and maintenance is easy.

DESCRIPTION OF SYMBOLS 1 Upper collar 2 Lower collar 4 Concave part 7 Convex part 8 Rubber bowl 9 Center hole 15 Space | gap 17 Small diameter hole 18 Large diameter hole 19 Upper lift stop bolt 20 Bolt head 50 Upper structure 51 Lower structure

Claims (3)

A fixed bearing installed between the upper structure and the lower structure, for transmitting the load of the upper structure to the lower structure;
An upper collar fixed to the upper structure and having a recess on the lower surface;
A lower collar having a convex portion fixed to the lower structure and fitted into the concave portion at an upper portion;
A fixed bearing, comprising: a high-load-resistant rubber rod that is disposed between a bottom surface of the concave portion and an upper surface of the convex portion and forms an annular gap between the inner periphery of the concave portion.   The fixed bearing according to claim 1, wherein the rubber hook is made of natural rubber or urethane rubber. The rubber hook has a center hole, and the upper hook has a small diameter hole provided in order from the bottom surface side of the recess and a large diameter hole connected thereto.
An upper lifting force stopping member having a diameter smaller than that of the center hole is inserted into the central hole of the rubber rod and the small diameter hole of the upper flange, and the upper lifting force stopping member has a lower end fixed to the lower rod and an upper end portion. The fixed bearing according to claim 1 or 2, wherein the large-diameter portion formed in the upper housing is accommodated in the large-diameter hole of the upper collar and can be engaged with the lower surface thereof.

Images