JP2018080522A - Tread of steel staircase and steel staircase provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tread of a steel staircase making it possible to ensure excellent quietness at a low cost without impairing safety.SOLUTION: A tread 1A of a steel staircase formed of a tread plate 4a, a front plate 3b, a bottom plate 3a, and a rear face plate 3c using a steel plate, is characterized in that the front plate 3b, the bottom plate 3a, and the rear face plate 3c are continuously formed by bending a single steel plate; the bottom plate 3a forms a horizontal plane 30 between a pair of inclined planes 31 and 32 formed on both sides thereof in the short diameter direction with the central side in the short diameter direction projecting upwardly throughout the long diameter direction; and the tread plate 4a is supported from below by the horizontal plane 30 in surface contact therewith.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a steel stair tread and a steel stair provided with the same, and more particularly to a steel stair tread having a silent function by a vibration control structure and a steel stair provided with the same.

  Steel staircases (steel stairs) made of steel with treads and sagittal girders that support both ends are easy to sound because they are entirely made of steel plates, and noise due to shoe sounds during ascending / descending tends to be a problem. Therefore, a plurality of steel plate tread bodies whose upper surfaces are opened in a dish shape are fixed between two spar girders to form a steel staircase base, which is installed in the building and mortar is placed in each tread body. By filling and solidifying, the quietness of the tread is ensured.

  However, in this method, when the weight of the plate-shaped tread body formed by bending a steel plate, the mortar to be filled in it, and the finishing material to be the tread are combined, the total weight is significantly larger than that of a tread made only of a steel plate. It will be big. In addition, the installation requires the labor and cost of filling and leveling the mortar into the tread body at the site, and there is a problem that the stairs cannot be used until the mortar is solidified.

  On the other hand, by using a damping plate in which a damping material made of a viscoelastic material or the like is sandwiched between two steel plates as a tread plate body, quietness can be achieved without using an inorganic filler such as mortar. A technique to be secured was proposed in Japanese Utility Model Publication No. 51-23321. Japanese Patent Application Laid-Open No. 6-261161 also proposes a technique for ensuring quietness by superimposing a damping plate as described above on a structural member made of steel plate.

  However, when a damping plate that combines a steel plate and damping material is used for the tread as described above, extra labor and cost are required to produce a tread that can achieve both safety and silence due to sufficient load strength. Therefore, as a result, the manufacturing cost of the step board and the steel staircase is likely to increase. Moreover, since it is normal to use the combustible material derived from petroleum for the damping material used for a damping board, it is thought that there also exists a problem also from a viewpoint on disaster prevention.

Japanese Utility Model Publication No. 51-23321 JP-A-6-26161

  An object of the present invention is to solve the above-described problems, and it is an object of the present invention to ensure excellent quietness at a low cost without impairing the safety of a steel stair tread.

  Therefore, the present invention is a steel stair tread formed by using a steel plate to form a tread plate, a front plate, a bottom plate, and a rear plate, and the front plate, the bottom plate, and the rear plate bend one steel plate. The bottom surface plate forms a horizontal plane between a pair of inclined surfaces formed on both ends of the minor axis direction while the center side in the minor axis direction protrudes upward over the entire major axis direction. The tread board is supported from below by making surface contact with the horizontal plane.

  In this way, by adopting a structure that supports the tread plate from the bottom in contact with the tread plate at the center while bending so that the center side in the minor axis direction of the bottom plate protrudes upward, the support force by the arch structure In addition to increasing the load strength of the tread plate, the vibration of the tread plate that occurs during the lifting operation is absorbed by the bottom plate that is in contact with it, making it difficult to resonate, so it is excellent at low cost without sacrificing safety It is possible to realize sex.

  Further, in this tread, a pair of inclined surfaces constituting a part of the bottom plate form a hollow portion having a lateral triangular prism shape in which one of the front plate and the front of the tread plate is an inverted triangle in a side view, On the other side, the rear plate and the rear portion of the tread plate form a triangular prism-shaped cavity with an inverted triangle when viewed from the side, and nuts for bolting the tread plate to the further spar on each of the left and right sides of the hollow portion. If it is characterized by being disposed and fixed, the load strength can be further improved while being easy to attach to the spar with a simple structure.

  Further, in the above-described steel stair tread, a sheet-like vibration absorber made of a flame retardant material is in close contact between the bottom surface of the tread plate and the top surface of the bottom plate at the portion where the tread plate and the bottom plate are in surface contact. If it is characterized by the fact that it is interposed in the state to form a vibration damping layer, the flame retardant vibration damping layer will exhibit a vibration absorbing function, making it even quieter without compromising safety Excellent in properties.

  Still further, in the above-described steel stair tread, the rear face plate has an upper end extending upward to form a kick plate as it is, and a predetermined range on the upper end side of the kick plate is located on the upper side. If it is characterized by forming a connecting plate that is bent at an angle parallel to the inclined surface of the front face plate and is connected to the front face of the bottom plate while making surface contact from below, A steel staircase can be completed simply by laying between the parallel beams.

  In this case, a sheet-like vibration absorber made of a flame-retardant material is interposed in a state where the connection plate is in surface contact with the front portion of the bottom plate to form a damping layer. As a result, the vibrations of the treads are difficult to be transmitted to the treads adjacent to each other in the vertical direction, and the entire steel staircase is less susceptible to noise.

  In addition, the bottom surface plate forms a horizontal plane between a pair of inclined surfaces formed on both ends of the minor axis direction while projecting upward in the width direction center side in the width direction, and is in surface contact with the horizontal plane. If steel stairs are formed by fixing multiple treads of any of the above-mentioned treads that support the treads from below, at equal intervals between the parallel spar girders, it is easy to make steel at low cost. Stairs can be installed in the building.

  According to the present invention having a structure in which the center side in the minor axis direction of the bottom plate protrudes upward and supports the tread plate from below, excellent quietness can be secured at low cost without impairing safety.

It is a longitudinal cross-sectional view which shows the structure of the tread of embodiment in this invention. It is a top view which shows the state of the tread board main body before providing the upper board of the tread board of FIG. FIG. 2 is a partial cross-sectional view showing a state in which a plurality of treads shown in FIG. It is a longitudinal cross-sectional view which shows the application example of the tread board of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present invention, the flame retardant material refers to a material having an oxygen index (OI) of JIS of 27 or more.

  FIG. 1 is a longitudinal sectional view of a tread 1A according to the present embodiment cut in the minor axis direction, and FIG. 2 is a receiving plate (tread main body) 3 before the upper plate 4 of FIG. 1 is provided. Is shown in a plan view. The tread plate 1A is formed by using a steel plate to form a tread plate 4a, a front plate 3b, a bottom plate 3a, and a rear plate 3c. It constitutes a steel staircase.

  The front plate 3b, the bottom plate 3a, and the rear plate 3c are formed by bending one steel plate, and the upper surface of the rear plate 3c is extended to the kick plate 3d and the upper tread plate 1A as it is. A connecting plate 3e to be connected is formed, and the receiving plate 3 is constituted by these. Moreover, the upper board 4 which formed the flat tread board 4a is arrange | positioned so that the upper surface side of this receiving plate 3 may be covered.

  In the present invention, the bottom plate 3a formed between the front plate 3b and the rear plate 3c of the receiving plate 3 protrudes upward in the major axis (width) direction at the center in the minor axis direction. A horizontal plane 30 is formed between a pair of inclined surfaces 31 and 32 formed on both ends of the minor axis direction, and a structure that supports the tread plate 4a from below while making surface contact with the horizontal plane 30 is adopted. It is characterized by that.

  As described above, the horizontal surface 30 lifted by the inclined surfaces 31 and 32 by projecting the center side in the minor axis direction of the bottom surface plate 3a is configured to support the tread surface plate 4a in surface contact from below. As a result, the load strength of the tread plate 4a is increased by the support force of the arch structure, and the vibration of the tread plate 4a accompanying the lifting operation is absorbed by the horizontal portion 30 of the bottom plate 3a that is in surface contact with it from below. By dampening, the function of making the sound of shoes difficult to sound is exhibited. Therefore, in addition to being superior to existing products using flammable resin damping materials, it is possible to realize excellent quietness even at low cost.

  In addition, the bottom plate 3a has one inclined surface 31 constituting a part thereof, and a front side plate 3b and a front portion of the tread plate 4a form a side triangular prism-shaped cavity 5 in an inverted triangle in a side view, The other inclined surface 32 forms six lateral triangular column-shaped cavities in an inverted triangle in a side view by the rear plate 3c and the rear portion of the tread plate 4a. Furthermore, as shown in the plan view of FIG. 2, the hollow portions 5 and 6 are respectively closed at the left and right openings by inverted triangular side plates 10 and 11. Nuts 12 for bolting the tread board 1A to the spar are arranged with bolt holes open, and are bolted to the spar at four places.

  In this way, the triangular plate-like structure formed with the longitudinal direction set to the major axis direction of the tread plate while supporting the upper plate 4 while the base plate 3 is made by bending one steel plate is supported in parallel with the minor axis direction. As a result, even with a relatively lightweight tread 1A made of a thin steel plate, it is possible to demonstrate excellent load strength, and it is easy to mount it on a quick girder. The point is also an important characteristic part in the present invention.

  On the other hand, the upper plate 4 is welded to the receiving plate 3 side on both sides of the short diameter method of the tread plate 4a in which a rectangular steel plate is bent downward in a predetermined range in the short diameter direction on both long sides. The connection plates 4b and 4c for fixing are formed. As shown in FIG. 2, the connection plates 4b and 4c are welded materials 350 at the positions of the welding holes 35, 35, 35,... Continuously provided in the width direction on the front plate 3b and the rear plate 3c. , 360 for welding and fixing.

  FIG. 3 is a longitudinal sectional view showing a state in which a plurality of the treads 1A shown in FIG. Each tread 1A is fixed to a saddle girder by screwing bolts 13 into nuts 12 provided on both left and right ends thereof, but the upper end side of the rear plate 3c of each tread 1A is extended to form a kick plate 3d. The kick plate 3d has an upper end that is bent at the same angle so as to be parallel to the inclined surface 31 of the front surface of the bottom plate 3a of the other tread plate 1A located on the upper side, and is inclined to the inclined surface 31 from below. Since the contact plate 3e that is in contact is formed, the steel staircase is completed simply by fixing a plurality of tread plates 1A to the spar.

  FIG. 4 is a longitudinal sectional view of a tread 1B as an application example of the above-described tread 1A. In the tread 1B, a vibration absorber made of a flame-retardant synthetic resin material is interposed between the bottom surface of the tread plate 4a and the top surface of the bottom plate 3a at a portion where the tread plate 4a comes into surface contact with the bottom plate 3a from below. It is characterized by the fact that it forms a damping layer 9.

  As described above, since the flame-retardant damping layer 9 is disposed in close contact between the tread plate 4a and the bottom plate 3a, the damping layer 9 exhibits a vibration absorbing function. It is excellent in quietness. In addition, as a flame-retardant material constituting the vibration damping layer 9, in addition to a material having a predetermined level of viscoelasticity formed in advance in a sheet shape, a paint or an adhesive that exhibits a vibration absorbing function in a solidified state is used. What was formed in the sheet form by applying beforehand to the lower surface of the tread plate 4a or the upper surface of the bottom plate 3a is assumed.

  In addition, although not shown in the drawings, in common with the above-described treads 1A and 1B, a vibration caused by the same flame-retardant material as described above is formed in a portion where the connecting plate 3e is in surface contact with the inclined surface 31 at the front of the bottom plate 3a. It is good also as what formed the damping layer by interposing an absorber in the upper and lower contact state. As a result, the vibrations of the treads 1A and 1B are less likely to be transmitted to the treads 1A and 1B adjacent to each other in the vertical direction, so that the entire steel staircase is less susceptible to noise.

  Next, the present invention will be described in more detail with reference to an example in which the above-described tread is actually created. The created tread (test product) has the same configuration as that shown in FIG. 1, and the receiving plate is a 2.3 mm thick steel plate with a major axis (width) of 1210 mm, a minor axis of 305.1 mm, and a height of 176. The upper plate is a 1.6 mm thick steel plate with a major axis (width) of 1210 mm and a minor axis of 265.5 mm. These treads were fixed to a supporting member made of a pair of steel plates with a thickness of 12 mm and corresponding to a saddle girder with bolts. Further, as a control example, a conventional product formed by bending a steel plate having a thickness of 3.2 mm to form a tread plate having a major axis (width) of 1200 mm and a minor axis of 276 mm and a kick plate having a height of 175.6 mm was used.

(Test method) For the test product and the reference example, a: time series data recorded at b: a, each recording the sound pressure when the golf ball dropped from a height of 1.2 m and collided with the center of the tread plate The noise level and the frequency analysis data were obtained for each, and c: the coefficient of restitution was obtained from the height at which the golf ball bounces when the golf ball was dropped from a height of 0.5 m in the same manner as described above.

(Result) The test product had a noise level of 79.0 dB, a natural frequency of 721 Hz, and a restitution coefficient of 0.321, and the control example had a noise level of 83.1 dB, a natural frequency of 1400 Hz, and a restitution coefficient of 0.635. From the above results, it was found that the test product according to the present invention had a low noise level and excellent quietness as compared with the control example. In addition, although the natural frequency of the noise was significantly lower in the test product than in the control example, it is presumed that this characteristic is effective in reducing the discomfort given to humans. Also, the level of restitution coefficient is considered to be related to the noise level and the natural frequency.

  Separately from this test, a load test was conducted on the above-mentioned test product to check the deformation state by continuously loading the center part from above, but the displacement in the vertical direction was 1.8 mm at 3 kN, Since plastic deformation did not occur even at 20 kN (displacement 20 mm), it was found that a test article made of a combination of a steel plate having a thickness of 2.3 mm and 1.6 mm has sufficient load strength of the level normally required. It was.

  As described above, according to the present invention, excellent quietness can be secured at a low cost without impairing the safety of the steel stair tread.

  1A, 1B Tread plate, 3 Receiving plate, 3a Bottom plate, 3b Front plate, 3c Rear plate, 3d Kick plate, 3e, 4b, 4c Connection plate, 4 Top plate, 4a Tread plate, 5,6 Cavity, 9 Damping Layer, 10, 11 Side plate, 12 Nut, 13 Bolt, 30 Horizontal part, 31, 32 Inclined surface, 35 Welding hole, 350, 360 Welding material

Claims (6)

  In a steel stair tread formed by using a steel plate to form a tread plate, a front plate, a bottom plate, and a rear plate, the front plate, the bottom plate, and the rear plate are formed continuously by bending one steel plate. The bottom plate forms a horizontal plane between a pair of inclined surfaces formed at both ends of the minor axis direction while the minor axis direction central side protrudes upward over the entire major axis direction, and the horizontal plane A tread of a steel staircase, characterized in that the tread plate is supported in contact with the base plate from below.   One of the pair of inclined surfaces constituting a part of the bottom plate forms a hollow triangular prism-shaped cavity with an inverted triangle when viewed from the side by the front plate and the front portion of the tread plate, and the other is the rear plate. The face plate and the rear portion of the tread plate form an inverted triangular side-view hollow with a triangular shape when viewed from the side, and nuts for bolting the tread plate to the further spar are arranged on the left and right ends of the hollow portion. 2. The steel stair tread according to claim 1, wherein the steel stair tread is installed and fixed.   A sheet-like vibration absorber made of a flame retardant material is interposed between the lower surface of the tread plate and the upper surface of the bottom plate at the portion where the tread plate and the bottom plate are in surface contact. 3. A steel stair tread according to claim 1 or 2, wherein a vibration layer is formed.   The rear plate has an upper end extending upward to form a kick plate as it is, and a predetermined range on the upper end side of the kick plate is parallel to the inclined surface of the front portion of the bottom plate of the tread plate located on the upper side. 4. The steel stair tread as claimed in claim 1, wherein a connecting plate is formed that is bent at an angle and is connected to the front portion of the bottom plate while making surface contact from below.   A vibration-absorbing layer is formed by interposing a sheet-like vibration absorber made of a flame-retardant material in a state where the connection plate is in surface contact with the front portion of the bottom plate so as to be in close contact with each other. A steel stair tread according to claim 4.   The bottom plate forms a horizontal plane between a pair of inclined surfaces formed at both ends of the minor axis direction while projecting upward in the width direction center side in the entire width direction, and is in surface contact with the horizontal plane while being in surface contact with the horizontal plane. A steel stairs formed by fixing the treads according to claim 1, 2, 3, 4 or 5 at equal intervals between parallel spars.

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