JP6179710B2 - Handrail and handrail - Google Patents

Description

  The present invention relates to a handrail bar and a handrail.

  With the progress of an aging society in recent years, the necessity of installing handrails at stairs, washrooms, toilets, corridors, entrances, entrances, etc., also tends to increase in ordinary houses. In particular, the handrail installed along the stairs needs to support the weight of the person when going up and down the stairs, and the handrail is required to have sufficient strength characteristics to withstand the load.

  Conventionally, as a handrail rod material, natural wood, laminated wood, woody material such as medium density fiberboard (MDF), metal such as aluminum and stainless steel, resin, and the like are used. For handrail bars for indoor use, a wood material having a good touch and a relatively high strength is generally preferred.

  However, even if it is a handrail bar made of a relatively strong wooden material, when securing it to a wall surface, a pillar, etc. via a bracket to ensure the strength as a handrail, the span between the brackets is, for example, 900 mm In many cases, the construction is shortened to within.

  By the way, in order to shorten the construction time of the handrail or reduce the construction cost such as reducing the number of brackets to be used, it is desirable to lengthen the span between the brackets.

  However, a handrail bar formed from a general wood material is difficult to achieve strength enough to withstand use as a handrail when the span is lengthened, and there is a concern about safety.

  Therefore, a handrail bar using a single plate laminated material (LVL: Laminated Veneer Lumber) that is laminated and bonded to a wood veneer composed of high specific gravity wood and a handrail formed from this balustrade bar Has been proposed (see, for example, Patent Document 1).

  The handrail bar described in Patent Literature 1 is cut out to a desired shape from an LVL made of a high specific gravity single plate that is joined to a finger joint or a scarf joint every predetermined length. Since the veneer has a high specific gravity and the joint between the veneers is strong, the handrail bar obtained has improved strength compared to the case of using general laminated material or MDF, and the span between brackets in the handrail Can be lengthened.

JP-A-2005-207154

  However, for handrail bars and handrails described in Patent Document 1, it has become difficult to procure high-quality, high-specific log logs due to recent global environmental protection and stricter regulations on depletion of wood resources. There was an aspect that it was difficult to suppress supply and manufacturing costs.

  The present invention has been made in view of the circumstances as described above, and is formed from a handrail bar excellent in strength characteristics and capable of stable supply and capable of suppressing manufacturing costs, and the handrail bar. The issue is to provide handrails.

In order to solve the above problems, a handrail bar of the present invention is a handrail bar formed from a bamboo LVL material formed by laminating and bonding bamboo flat plates with their fiber directions aligned, and this handrail bar. The maximum load is 1400 N or more and the deflection when the load is 1200 N is within 80 mm, the bamboo flat plate is cut on the inner surface side more than the surface side, and the lower layer in the stacking direction of the bamboo LVL material is the bamboo flat plate The surface on the front side is down, and the layer on the upper side in the stacking direction is characterized in that the surface on the front side of the bamboo slab is on top and is vertically symmetrical .

This railing rod, it is preferable air dried density of Takehira plate is in the range of ^{700kg / m 3 ~1000kg / m 3} .

  The handrail of the present invention is a handrail formed by supporting the handrail bar with a bracket, and a span between the brackets is 1.2 m or more.

  According to the handrail bar and the handrail of the present invention, a handrail bar having excellent strength characteristics and a handrail formed from the handrail bar, which can be stably supplied and can be manufactured at a reduced cost.

  Hereinafter, an embodiment of the handrail and handrail of the present invention will be described in detail.

  The handrail bar is made of a bamboo LVL material formed by laminating and bonding bamboo flat plates with their fiber directions aligned. The bamboo flat plate forming the bamboo LVL material is cut on the inner surface side more than the surface side.

  A bamboo flat plate is a flat plate obtained by cutting bamboo, which is a raw material, into a desired length, vertically cutting with a bamboo splitting machine, bleaching, and then cutting the surface, inner surface and side surfaces.

  Examples of the type of bamboo used for the bamboo flat plate include true bamboo, go bamboo, pillar bamboo, sect bamboo, bamboo and the like. Bamboo is abundant all over the world because of its vigorous fertility and rapid growth. Bamboo grows very fast compared to timber, can be supplied stably, and can reduce manufacturing costs. In addition, bamboo, which has a bamboo age of less than one year, is poor in rigidity and does not have toughness. However, if bamboo age is more than one year, it has rigidity and toughness. It has stable strength characteristics.

  Bamboo that has just been cut is called green bamboo, and is not suitable for use as a building material because of its high water content and oil content. Therefore, first, the vertically divided green bamboo is boiled and bleached in, for example, a sodium hydrogen peroxide solution. Bleaching is also possible by immersing the vertically divided green bamboo in a sodium hypochlorite solution at 30 ° C. to 40 ° C. for 5 minutes. Since the sodium hypochlorite solution is an alkaline solution that exhibits a strong oxidizing action, it is necessary to lift the vertically divided bamboo from the sodium hypochlorite solution, and then thoroughly wash and wipe it off.

  In the cross section of the bamboo plate, parenchyma cells and vascular bundles, which are the tissue structure of bamboo, which is the raw material, exist. A parenchyma cell is a tissue having a thin cell wall and a relatively low strength, whereas a vascular bundle is an aggregate of plant fibers having a thick cell wall, and therefore has a very high strength. A large amount of vascular bundles are distributed near the surface side of the bamboo flat plate and few on the inner surface side. On the other hand, the soft tissue is more on the inner surface side of the bamboo flat plate. For this reason, by cutting more on the inner surface side than the surface side of the bamboo flat plate, the proportion of the soft tissue in the bamboo flat plate can be reduced, the proportion of the vascular bundle can be relatively increased, and the air dry density can be increased. it can. Examples of the method of cutting the bamboo flat plate include conventionally known slicers, horizontal belt sanders, grinders, electric planes and the like.

As described above, it is possible to increase the air dry density of the bamboo flat plate by cutting the inner surface side more than the surface side of the bamboo flat plate. The air dried density of Takehira plate ^is preferably set in the range of ^{700kg / m 3 ~1000kg / m 3} . If the air-drying density of the bamboo flat plate is within the above range, the handrail bar is excellent in basic performance such as strength and durability, and is advantageous in terms of cost.

  The width and thickness of the bamboo flat plate are not particularly limited, but considering the basic performance such as strength, durability and dimensional stability of the handrail bar, the width is in the range of 20 mm to 150 mm, and the thickness is It is preferably within a range of 2 mm or more and 10 mm or less.

  Further, the length of the bamboo flat plate is not particularly limited, but it is preferably 500 mm or more in consideration of basic performance such as strength, durability and dimensional stability of the handrail bar.

  A long bamboo flat plate can be obtained by connecting a plurality of bamboo flat plates at the edge portion. There is no particular limitation on the method of laminating the bamboo flat plate, but it is preferable to laminate the layers so that the seams in the width direction do not overlap, and the seams in the length direction are also laminated so as not to overlap. Is preferred. When connecting the bamboo flat plate at the small edge portion, it is preferable to jointly process the small edge. Examples of joint processing include finger joints and scarf joints. Moreover, when laminating a long bamboo flat plate, it is preferable to laminate the jointed connection portions while shifting the phase in the longitudinal direction. Thereby, the strength against the load of the handrail bar can be improved.

  A bamboo LVL material is obtained as a cross section having a substantially square shape by laminating and bonding bamboo flat plates as described above.

  By laminating so that the fiber directions of high strength vascular bundles are aligned and bonding bamboo flat plates, the strength characteristics can be greatly improved even with a long handrail bar.

  The kind of adhesive applied to the bamboo flat plate is not particularly limited. The adhesive may be liquid or solid. For example, an isocyanate resin adhesive composed of MDI (diphenylmethane diisocyanate), TDI (tolylene diisocyanate), MDI prepolymer, TDI prepolymer and the like is exemplified. Examples include urea resin adhesives, melamine resin adhesives, urea / melamine cocondensation resin adhesives, phenol resin adhesives, resorcinol resin adhesives, epoxy resin adhesives, urethane resin adhesives, furfural resin adhesives, and the like. . These adhesives can be used alone or in combination of two or more. For the selection of the adhesive, water resistance of bamboo LVL material, the amount of formaldehyde released causing sick house syndrome, and the like can be considered. Since the isocyanate resin adhesive does not use formaldehyde as a raw material, it is a highly safe adhesive. Moreover, a sizing agent etc. can be added to an adhesive agent as needed. By applying such an adhesive to the bamboo flat plate, the strength of the bamboo LVL material can be improved and the handling property can be improved.

  Examples of methods for applying an adhesive to a bamboo flat plate include, for example, a conventionally known flow coater, roll coater, spraying method, airless spray method, air spray method, brush coating, trowel coating, dipping method, lifting method, nozzle method, winding method. Examples include a removing method, a sink method, a serving method, a patching method, and the like.

  When heating and pressure forming after laminating bamboo flat plates coated with adhesive, for example, a continuous press device that conveys the laminate while applying pressure to the gap between a pair of heated steel belts, or a plurality of heated heat A multi-stage press apparatus or the like that pressurizes with a laminate sandwiched between plates can be used. The molding conditions are not particularly limited. For example, the range of 120 to 190 ° C. as the molding temperature and the range of 1 to 4 MPa as the molding pressure are exemplified. The pressurization time can be appropriately set in consideration of the vertical and horizontal dimensions of the cross section of the bamboo LVL material obtained after the heat and pressure molding, the heating temperature at the time of molding, and the like. About the vertical and horizontal dimension of the cross section of a bamboo LVL material, the inside of the range of 40 mm-100 mm is illustrated, for example.

  The handrail bar is obtained by cutting the outer peripheral surface of the bamboo LVL material as described above and processing the cross-sectional shape into a circle or an ellipse.

  Examples of the method for cutting the outer peripheral surface of the bamboo LVL material include pressing a cutting tool against the outer peripheral surface of the bamboo LVL material while rotating the rod-shaped bamboo LVL material around its axis. The cutting conditions are not particularly limited, but can be appropriately set in consideration of the diameter of the handrail bar obtained after cutting. In the case where the handrail has a circular cross section, the diameter is, for example, in the range of 30 mm to 70 mm.

  Since the surface of the handrail bar formed by cutting the outer peripheral surface of the bamboo LVL material stands up and down, it is preferable to sand the surface to make the surface smooth. Further, the surface of the handrail bar may be coated with a decorative material having a natural wood texture, or may be painted with a polyurethane resin paint or the like.

  Since the handrail bar is made by laminating and adhering bamboo flat plates having the same fiber direction, the bamboo LVL material has a small deflection with respect to a bending load and is particularly excellent in performance such as strength.

  The handrail is formed by fixing the handrail bar with a bracket. The bracket is fixed to the inner wall surface or pillar of the building by a fixing tool such as a screw. The span between brackets in a handrail is generally about 90 cm, but even if the handrail bar of the present invention is used, it can be used even if it is 1.2 m or longer. As described above, the handrail bar has a small deflection with respect to a bending load and is particularly excellent in performance such as strength as compared with the conventional one. For this reason, in a handrail, the space | interval between brackets can be enlarged. Therefore, in the handrail, the number of brackets can be reduced, and the number of parts can be reduced. In addition, since the area around the bracket is clean, it is possible to realize a handrail with a good appearance.

  The handrail is also superior in basic performance such as strength and durability, as well as the handrail bar, and is advantageous in terms of cost.

  Hereinafter, examples will be shown, and the handrail bar and the handrail of the present invention will be described in more detail. However, the present invention is not limited to the examples.

Example 1
Bamboo soak bamboo with a diameter of about 20 cm cut into 2 m lengths was divided with a bamboo splitting machine to obtain bamboo strands as flat plate materials with a width of about 30 mm and a thickness of 10 to 15 mm.

  Next, the bamboo strands were heated to dry so that the water content was 15% or less.

  Next, the surface side and the inner surface side of the dried bamboo strand were partially cut and removed by a rough cutting machine and processed so as to have a thickness of about 10 mm and a width of about 25 mm.

  Next, as a finishing process, a bamboo flat plate having a width of 25 mm and a thickness of 4.5 mm was obtained by cutting the surface side of the bamboo strand from which the surface side and the inner surface side were partially removed by cutting about 1.5 mm and the inner surface side by about 4 mm .

After applying an adhesive to the obtained bamboo flat plate, the fiber directions were aligned, and eight layers were laminated while shifting so that the seams did not overlap in both the length direction and the width direction. The lower 4 layers are laminated so that the surface of the bamboo flat plate faces down, and the upper 4 layers are laminated so that the surface of the bamboo flat plate faces up so that they are vertically symmetrical. did. As an adhesive, a water-based vinyl urethane adhesive was applied at 200 g / m ² .

  Next, the bamboo flat plates laminated and bonded were heated and pressed at a temperature of 150 ° C. for 30 minutes to obtain a bamboo LVL material having a length of 4100 mm, a width of 300 mm, and a thickness of 36 mm.

This was cut into a width of 36 mm using a slicer and then processed into a round bar shape having a diameter of 34.5 mm using a molder machine to obtain a handrail bar. The air dry density of the handrail bar was 750 kg / m ³ .

(Example 2)
Bamboo soak bamboo with a diameter of about 20 cm cut into 2 m lengths was divided with a bamboo splitting machine to obtain bamboo strands as flat plate materials with a width of about 30 mm and a thickness of 10 to 15 mm.

  Next, the bamboo strands were heated to dry so that the water content was 15% or less.

  Next, the surface side and the inner surface side of the dried bamboo strand were partially cut and removed by a rough cutting machine and processed so as to have a thickness of about 10 mm and a width of about 25 mm.

  Next, as a finishing process, the surface side of the bamboo strand from which the surface side and the inner surface side were partially cut and removed was not cut, but only the inner surface side was cut by about 7 mm to obtain a bamboo flat plate having a width of 25 mm and a thickness of 3 mm.

  After the adhesive was applied to the obtained bamboo flat plate, the fiber directions were aligned, and 12 layers were laminated while shifting so that the seams did not overlap in the length direction and the width direction. In addition, the lower 6 layers are laminated so that the surface of the bamboo flat plate faces down, and the upper 6 layers are laminated so that the surface of the bamboo flat plate faces up so that they are vertically symmetrical. did.

Other than that was carried out similarly to Example 1, and obtained the handrail stick. The air dry density of the handrail bar was 950 kg / m ³ .

(Example 3)
Bunso bamboo with a diameter of about 20 cm cut into 2 m lengths was divided with a bamboo splitting machine to obtain bamboo strands as flat plate raw materials with a width of about 120 to 150 mm and a thickness of 10 to 15 mm.

  Next, this bamboo strand was dried and simultaneously pressed by a hot plate press.

  Next, the surface side and the inner side of the hot-pressed bamboo strand were partially cut and removed by a rough cutting machine, and the width was processed so that the thickness was about 10 mm and the width was about 100 mm.

  Next, as a finish processing of the bamboo strand with the surface side and the inner surface side partially cut and removed, the surface side was cut by about 0.5 mm and the inner surface side was cut by about 5 mm to obtain a bamboo flat plate having a width of 100 mm and a thickness of 4.5 mm. .

After applying an adhesive to the obtained bamboo flat plate, the fiber directions were aligned, and eight layers were laminated while shifting so that the seams did not overlap in both the length direction and the width direction. The lower 4 layers are laminated so that the surface of the bamboo flat plate faces down, and the upper 4 layers are laminated so that the surface of the bamboo flat plate faces up so that they are vertically symmetrical. did. As an adhesive, a water-based vinyl urethane adhesive was applied at 200 g / m ² .

  Next, a bamboo LVL material having a length of 4100 mm, a width of 300 mm, and a thickness of 36 mm was obtained by hot pressing at a temperature of 150 ° C. for 30 minutes.

This was cut into a width of 36 mm and then processed into a round bar shape having a diameter of 34.5 mm using a molder machine to obtain a handrail bar. The air dry density of this handrail bar was 850 kg / m ³ .

(Comparative Example 1)
A high specific gravity LVL having a thickness of 36 mm made of a single eucalyptus plate was used as a raw material for a round bar, and was processed into a round bar shape with a diameter of 34.5 mm in the same manner as in Example 1 to obtain a handrail bar. The air dry density of this handrail bar was about 850 kg / m ³ .

(Comparative Example 2)
A rubber assembly with a thickness of 36 mm was used as a raw material for the round bar, and was processed into a round bar shape with a diameter of 34.5 mm in the same manner as in Example 1 to obtain a handrail bar. The air dry density of this handrail bar was about 750 kg / m ³ .

(Comparative Example 3)
A handrail bar was obtained in the same manner as in Example 1 except that the surface side of the bamboo flat plate was cut by 3.0 mm and the inner surface side was cut by 2.5 mm. The air dry density of the handrail bar was 650 kg / m ³ .

For the handrail bars obtained in Examples and Comparative Examples, the maximum load at break and the amount of deflection at a load of 1200 N were measured as the strength characteristics of the handrail bars, and the physical properties were evaluated. The criteria for evaluation are as follows.
<Strength characteristic evaluation>
The maximum load at the time of breaking was measured by cutting the obtained handrail bar having a length of 4 m into a length of 2 m and then using the handrail bar fixed to the wooden beam member by a bracket as a handrail test specimen. The span between the brackets was 1.5 m.

Using a universal testing machine, a bending test in which a load was applied with an indenter to the center of the span between the brackets of the handrail specimen was measured, and the maximum load at the time of failure was measured.
A: The maximum load is 1700 N or more.
◯: A range where the maximum load is 1400 N or more and less than 1700 N is taken as ◯.
Δ: A range where the maximum load is 1000 N or more and less than 1400 N is taken as Δ.
X: When the maximum load was less than 1000 N, it was set as x.

Similarly, the amount of deflection at a load of 1200 N was measured.
(Double-circle): When the load is 1200 N, the amount of deflection is less than 70 mm.
◯: A range where the deflection amount at a load of 1200 N was 70 mm or more and less than 90 mm was defined as ◯.
Δ: A range where the deflection amount at a load of 1200 N was 90 mm or more and less than 110 mm was taken as Δ.
X: The amount of deflection at a load of 1200 N is 110 mm or more.

  The evaluation results are shown in Table 1.

  As shown in Table 1, the handrails shown in Examples 1 to 3 have a high maximum load of 1400 N or more even in a bending test with a span between brackets of 1.5 m, and are excellent in safety in terms of strength. I understood that. In particular, as shown in Examples 2 and 3, when the inner surface side cutting amount was increased as compared with Example 1, it was confirmed that the maximum load of 1700 N or more and extremely excellent strength characteristics were exhibited.

  Moreover, the handrail shown in Examples 1 to 3 using bamboo LVL as a round bar raw material has a maximum load approximately 2-3 times that of the rubber laminated material of Comparative Example 2, and the high specific gravity eucalyptus of Comparative Example 1 Even when compared with a handrail using LVL, it was confirmed that excellent strength characteristics were exhibited.

  However, as shown in Comparative Example 3, even when bamboo LVL is used as a round bar raw material, if the surface side cutting amount is larger than the inner surface side cutting amount, the maximum load of the obtained handrail is reduced, which is sufficient as a handrail. It was confirmed that the strength performance could not be expressed.

  In addition, the deflection amount, which is another characteristic required for the handrail, shows the same tendency as the result of the maximum load, and the deflection amounts of Examples 1 to 3 are all less than 90 mm, particularly from the surface side. In Examples 2 and 3 in which the inner surface side cutting amount was increased, it was confirmed that the amount of deflection at the time of loading was less than 70 mm, which was an extremely small handrail.

Claims (3)

A handrail bar formed from bamboo LVL material that is formed by laminating and bonding bamboo flat plates in the same fiber direction, and the maximum load of the handrail bar is 1400 N or more and the deflection when a load of 1200 N is applied is within 80 mm In the bamboo flat plate, the inner surface side is cut more than the surface side, the lower layer in the stacking direction of the bamboo LVL material is the front surface of the bamboo flat plate, and the upper layer in the stacking direction is the bamboo flat plate. A handrail bar characterized by being vertically symmetrical with the front side of Handrail rod according to claim 1, wherein the air dried density of the bamboo flat is in the range of ^{700kg / m 3 ~1000kg / m 3} .   A handrail formed by supporting the handrail bar according to claim 1 or 2 by a bracket, wherein a span between the brackets is 1.2 m or more.