JP3392377B2 - Bamboo plate processing - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The technical field to which the present invention pertains is bamboo, which is a plant that propagates in rhizomes and completes growth in a short period of about 3 months in appearance and 3 years at the cell level. Is preferable for renewal of bamboo forest. Also,
Bamboo has unique strength and appearance. The present invention is an invention relating to an effective method of forming such a bamboo material as a plate material in order to effectively utilize such bamboo material.

[0002]

2. Description of the Related Art As a method of using bamboo, it has been proposed to utilize the shape of bamboo as a craft and to use it by forming it into a plate. For example, JP-A-59-4
No. 8103 removes the knot inside the hollow cylindrical bamboo material,
A method is disclosed in which after the inner diameter is processed to be constant, a notch having a constant depth is provided along the inner peripheral surface, the notch is opened in the longitudinal direction to be developed, and an adhesive is filled in the notch to form a flat plate. . Further, the idea of deforming a bamboo material into a flat shape in a heated state is disclosed in JP-A-62-90202 and JP-B-7-115.
No. 325 and the like. Furthermore, Japanese Patent No. 165249 discloses a method of providing a V-shaped groove on the outer surface of a bamboo material and expanding the bamboo material.

[0003]

In the method of providing a large number of grooves on the inner peripheral surface of a bamboo material and deploying it on a flat plate, tensile stress concentrates on the tip end portion of the groove during deployment deformation, so that tensile fracture is caused from there. It tends to occur. In addition, since a large number of large grooves are formed on the inner surface of the developed flat plate, the appearance is impaired, and although the adhesive is filled in here, a decrease in strength cannot be avoided.

[0004] As disclosed in Japanese Patent No. 165249, the method of providing V-shaped grooves on the outer surface of the bamboo material to develop the bamboo material allows a large number of large grooves to be formed on the inner surface of the flat plate.
The drawbacks of providing grooves on the inner peripheral surface of bamboo material are eliminated. However, when a V-shaped groove is provided on the outer surface of bamboo,
It was found that a large tensile stress acts on the thick wall portion from the tip of the V-shaped groove to the inner circumference, and the portion may break during the work.

In view of the above-mentioned drawbacks of the prior art, the present invention is a method for engraving a groove on the outer surface of a bamboo material to flatten it, and a tensile stress is applied as much as possible from the tip of the groove to the thick portion of the inner circumference. A flat plate of bamboo that can be easily processed without acting
The purpose is to provide a construction method. Also, flat
If the bamboo material processed into a plate shape is more reliably processed into a flat plate shape,
A concrete person who can make both board materials with air permeability
It is a devised method.

[0006]

As a pre-processing, the bamboo material 1 to be made into a plate material has a fixed length L while removing the knots.
And cut in half or at least partially in the longitudinal direction, preferably keeping the inner diameter r and outer diameter R constant over the entire length. A plurality of trapezoidal grooves 2 and 2 are formed in parallel on the outer peripheral surface of the pre-processed bamboo material 1 ′ so as to leave a continuous portion 3 that is shallower than the thickness t of the bamboo material 1 ′ and thin on the inner peripheral portion. Then
An arc-shaped bamboo material with a trapezoidal groove is developed into a flat plate. This
At the time of bending, it mainly bends to the thin plate-like continuous portion 3
A force is applied and the part is deformed to form a flat plate.
To do. A deformed groove may be used instead of the trapezoidal groove.
That is, the opening angle α of the left and right side walls is set between adjacent deformation grooves.
Formed at the same angle as the central angle of the
By cutting it to the width, the inner circumference of the bamboo material can be made thin
Form a plate-shaped continuous portion. In this deformation groove 2 ', left and right
Both side walls are in close contact and a gap 12 is formed at the lower end of the side wall
Therefore, the breathability can be improved.

[0007] In the process of developing into a flat plate, the groove formed on the outer peripheral surface of the bamboo piece 1'is a trapezoidal groove 2 in the present invention, so that it is bent into a thin plate-like continuous portion 3 of thickness t _2. Moment acts. Then, when a bending moment acts on the continuous portion 3, the inside of the continuous portion 3, that is, the bottom portion of the trapezoidal groove 2 is compressed and deformed to complete the processing. At this time, unlike the case where the V-groove is formed on the outer peripheral surface of the bamboo material 1 ', a large tensile force does not act on the continuous portion, and the possibility of damage is reduced.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the method for processing a flat plate of bamboo material according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an end view showing only a part of a bamboo material processed into a flat plate, and FIG. 2 is a perspective view showing a pre-processed status of the bamboo material to be processed. FIG. 11 is a flow chart showing an example of steps for carrying out the method of the present invention.

As the bamboo material 1 to be processed into a flat plate, it is preferable to use a thick and thick material such as Moso bamboo. Bamboo material 1 has its length L as a pre-processing shown in FIG.
As shown in (a), make sure that the knurls inside and the bulges on the surface of the knuckles are removed. Preferably,
The inner and outer surfaces are cut so that the inner and outer surfaces are smoothed so that the inner diameter r and the outer diameter R are the same over the entire length. The bamboo material 1'before being spread on the flat plate may be a substantially cylindrical shape as shown in FIG. 8 and a part of which is cut in the longitudinal direction, but it is a semi-cylindrical shape as shown in FIG. 2 (b). It is convenient to handle it.

As shown in FIG. 3, the pre-processed bamboo material 1'shown in FIG. 2 (b) is made parallel to the outer peripheral surface of the bamboo material 1'in the longitudinal direction and is shallower than the thickness of the bamboo material 1 '. , A plurality of trapezoidal grooves 2 and 2 are engraved so as to leave a thin continuous portion 3 in the inner peripheral portion. The plurality of trapezoidal grooves 2 and 2 may be provided on the outer peripheral surface of the bamboo piece 1 ′ at arbitrary intervals, but for example, the trapezoidal grooves 2 and 2 having a constant shape are provided at regular intervals such as the central angle α.

Trapezoidal grooves 2 and 2 formed on the outer peripheral surface of the bamboo material 1 '
Although the specific shape of the is not particularly limited, FIG.
As shown in, when the thickness T of the bamboo material 1'is 10 mm and the depth t ₁ of the trapezoidal groove 2 is 6 mm, the continuous portion 3
Has a thickness t ₂ of 4 mm. When the depth t ₁ is 7 mm, the thickness t _{2 of the} continuous portion is 3 mm. The valley width W ₂ of the trapezoidal groove 2 engraved on the outer peripheral surface of the bamboo material 1 ′ does not need to be large. For example, about 0.2 to 1.0 mm. The groove width W ₁ is preferably a width that is sealed when the bamboo material 1 ′ is expanded, that is, Ttan α or a dimension close to T tan α when the trapezoidal groove 2 is provided for each angle α of the bamboo material 1 ′.

In FIG. 5, a bamboo material 1'having a trapezoidal groove 2 formed on the outer peripheral surface is gradually expanded by applying pressure to form a flat plate. Although the method of unfolding is arbitrary, in the embodiment shown in FIG. 5 (a), a plurality of semi-cylindrical bamboo materials 1 ′, 1 ′ are stacked,
By applying pressure from above, all bamboo materials 1'are gradually developed and flattened as shown in FIG. 5 (b). As a method for developing the bamboo material 1 ′, it is possible to continuously process it by using a roller press in which the roller interval is gradually narrowed. At this time, if the processing for flattening the bamboo material 1 ′ is performed in the heating and drying furnace, heating and drying can be simultaneously advanced. That is, when the bamboo material is heated, it becomes plastic and can be processed so as not to break the thin continuous portion 3 of the inner circumference, and at the same time, it is possible to realize stable flat plate processing by drying.

That is, the deformation of the bamboo material 1'is mainly performed in the continuous portion 3 of the groove, but since the groove is the trapezoidal groove 2 in the present invention, the compressive force is applied to the upper half portion of the thickness t ₂ of the continuous portion 3. It deforms with tensile force acting on the lower half. By the way, the structure of bamboo undergoes compressive deformation due to compressive force, but it hardly breaks against tensile force and is destroyed. The morphology of the compressed and deformed tissue is stabilized by being dried. Therefore, in the present invention in which the groove is a trapezoidal groove, the upper side of the continuous portion 3,
That is, the valley width W ₂ portion of the trapezoidal groove is compressed and deformed into a flat plate . In the present invention, the deformation amount required for flattening is small as a whole, and even a bamboo material having a relatively low water content can be flattened without being damaged, so that it is possible to perform deformation processing for flattening under heating and drying conditions. Become. As before,
Than that provided just V grooves on the outer surface of the bamboo, the continuous portion
Large tensile force acts, requiring large deformation to extend to continuous part
Otherwise, it is necessary to compress and deform the opposite V-groove side surfaces over the entire thickness. Therefore, it breaks
It was easy.

The thickness of the flat plate on which one bamboo material 1'is developed is
It is determined by the thickness t of the bamboo material and is relatively thin, such as several millimeters to 1 centimeter. Naturally, this single plate can be used as a plate material, but it is also possible to use it as a thick plate material or pillar material by stacking two sheets or laminating them to a thickness of more than two. In order to complete a single plate as one flat plate, an adhesive is applied to the trapezoidal groove 2 and the opposite side surfaces are joined together to integrate the whole. As a processing method for efficiently adhering the opposite side surfaces of the trapezoidal groove 2, a flat plate is curved to open the trapezoidal groove 2 before or after the expansion processing, and a thermosetting adhesive is applied to the inside of the trapezoidal groove 2. It is advisable to adhere them by high frequency dielectric heating in the expanded state. That is, as shown in FIG. 6, the bamboo material 1 ′ is placed on the lower electrode 4 of the high-frequency dielectric heating device, the upper electrode 5 is arranged along the trapezoidal groove 2, and between the upper electrode 5 and the lower electrode 4. By applying a high frequency current, only the trapezoidal groove 2 portion can be efficiently heated in a short time. At this time,
A vertical press 6 that presses between the plurality of upper electrodes 5 and 5 and a press 7 that presses the bamboo material 1 ′ in the horizontal direction are arranged,
It is preferable that the flat plates are adhered in an accurate state.

The high-frequency dielectric heating device for heating and adhering the trapezoidal groove 2 may be either a continuous type or a batch type, but in the case of the batch type, it has a fixed lower electrode and a fixed length. It is a combination of the upper electrodes. In the case of the continuous type, the lower electrode 4 can be implemented as a combination of a conveyor having electrical conductivity, the upper electrode as a roller electrode connected to a high frequency power source, and the presses 6 and 7 can be performed as a combination of roller presses.

Although a flat plate obtained by expanding one bamboo material 1'is flattened by pressing, it is strictly a continuous arc piece and its surface is not necessarily flat. Therefore, in order to make a single plate into a complete flat plate, the outer peripheral surface including the upper and lower surfaces or the side surfaces is surface-processed by a four-plane planar.

Since the flat plate obtained by expanding one bamboo material 1'has a small thickness, it is conceivable that the flat plate is completed by stacking two pieces for convenience. In this case, as shown in FIG. 7 (a), a flat plate that is simply flattened or a flat plate to which the trapezoidal groove 2 is adhered is overlapped with the outer surfaces or the inner surfaces, and the adhesive 9 is applied between them. As shown in FIG. 7 (b), by continuously heating and adhering with the roller press 8 by high-frequency dielectric heating, two flat plates can be efficiently and continuously manufactured. In the case of making a two-layered flat plate, in the illustrated example, the single plates are superposed on the outer surfaces or on the inner surfaces. By doing this, the front and back surfaces are either the outer surface or the inner surface, so there is no difference in shrinkage ratio between the front and back surfaces, warpage due to moisture absorption and release is prevented, and even if the trapezoidal groove 2 is not bonded. Even in the case of stacking two single plates, since the two single plates cancel each other in the direction of easy bending in the trapezoidal groove portion, it is possible to obtain a relatively stable two-layer flat plate.

FIGS. 2 and 3 show an embodiment in which a bamboo material 1'which is divided into two parts is expanded, but as shown in FIG. 8, a single bamboo material having the inner and outer peripheral surfaces subjected to knot removal processing. It is also possible to use 1 to provide a vertical cutting portion 10 at at least one position and to deploy this. By doing so, a wider veneer can be obtained. On the contrary, when the bamboo material is large or is to be processed by a small processing facility, the bamboo material obtained by dividing one bamboo material into three or four pieces can be used.

In the process of expanding the bamboo material 1 ', a bending moment acts on the continuous portion 3 of the inner peripheral portion. Although the continuous portion has a small wall thickness, tensile stress still acts on the inner surface. Therefore, as shown in FIG. 9, it is also effective to stick a reinforcing sheet 11 such as paper to the inner peripheral surface of the bamboo material in order to smoothly carry out the work without causing tensile fracture on the inner surface. . The reinforcing sheet 11 attached to the inner peripheral surface may be integrated with the bamboo material even after completion of the flat plate or function as an integrated material or a reinforcing material, but may be scraped off by a four-sided pooner after the expansion processing. . In the case where the reinforcing material is cut off by the pooner, the completed flat plate or the laminated material thereof is formed only by the bamboo material. By using the reinforcing sheet 11 in the processing step, it is possible to make the continuous portion 3 of the inner peripheral portion of the bamboo piece 1 ′ as thin as possible.

The single plate or double-layered bamboo plate obtained by the above-mentioned method can be used as a building material or other various purposes, but it is further laminated to form a thick pillar material. It can also be used as a thick plate material. The processing method can be the same as that of the laminated wood which has been widely used in the past.

FIG. 10 (a) shows a modified groove 2'in place of the trapezoidal groove 2.
2 shows an embodiment . This deformation groove 2'is
The left and right side walls of the groove that spreads outward are formed at an opening angle α from the center of the valley of the deformed groove, and only the groove bottom portion is cut to the valley width W ₂ . In this way, as shown in FIG. 10 (b), the left and right side walls of the trapezoidal groove 2 can be completely brought into close contact with each other within the range of the thickness t _{3 which} is the inclined surface having the opening angle α, and at the same time the gap 12 is formed. It is possible to improve the breathability.

FIG. 10 (a) shows a modified embodiment of the trapezoidal groove 2. In this trapezoidal groove 2, the left and right side walls are formed with an opening angle α from the center of the valley of the trapezoidal groove, and only the groove bottom portion has a valley width W ₂
Has been resected. In this way, as shown in FIG. 10 (b), the left and right side walls of the trapezoidal groove 2 can be completely brought into close contact with each other within the range of the thickness t _{3 which} is the inclined surface having the opening angle α, and at the same time the gap 12 is formed. It is possible to improve the breathability.

According to the second aspect of the invention, the left side of the deformation groove
Both right side walls can be completely and closely
A gap is created at the lower end of the part, making it a plate material with excellent breathability.
You can

According to the second aspect of the present invention, since the deformation processing for flattening and the drying in the deformed state can be performed at the same time, the process can be simplified. That is, the continuous portion of the trapezoidal groove is plasticized by the heating of the heating and drying and is easily compressed and deformed, and the flat plate shape is stabilized by the drying.

[Brief description of drawings]

FIG. 1 is an end view showing a deformed state of bamboo when the method of the present invention is carried out,

FIG. 2 is a perspective view showing a bamboo material to be processed and a preprocessed state;

FIG. 3 is a perspective view and an end view in which a groove is formed on the outer peripheral surface of the pre-processed bamboo material,

FIG. 4 is an enlarged end view showing the shape of a trapezoidal groove formed on the outer surface of a bamboo material,

FIG. 5 is a front view showing an example of a step of expanding a bamboo material having a grooved outer peripheral surface into a flat plate;

FIG. 6 is a front view seen from the flow direction, showing an example of a high-frequency heating bonding machine for bonding the groove of the expanded bamboo material.

FIG. 7 is an end view showing a state in which the expanded bamboo material is processed into two layers, and a schematic view showing an example of a bonding machine.

FIG. 8 is an end view showing an example of expanding a cylindrical bamboo material into a single flat plate;

FIG. 9 is an end view of the bamboo material showing a state in which a reinforcing sheet is attached to the inner peripheral surface of the bamboo material,

FIG. 10 is an enlarged end view showing an example of a deformed shape of a trapezoidal groove engraved on a bamboo material,

FIG. 11 is a flowchart showing an example of steps for carrying out the method of the present invention.

[Explanation of symbols]

1, 1 '... bamboo material, 2 ... trapezoidal groove, 3 ... continuous part, 4 ...
Lower electrode, 5 ... Upper electrode, 6, 7 ... Press, 8 ...
Roller press, 9 adhesive, 10 ... cutting part, 11 ... reinforcing sheet, 12 ... gap.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-320504 (JP, A) Patent 165249 (JP, C2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B27J 1/00 B27K 1/00-9/00

Claims (2)

(57) [Claims] 1. A plurality of trapezoidal grooves are formed in the vertical direction on the outer peripheral surface of a bamboo material in which at least a part is cut in the vertical direction by removing a node.
In addition, the shape of the trapezoidal groove is thin on the inner circumference of the bamboo material.
The thin plate-shaped continuous part is formed by leaving a plate-shaped continuous part with
A flat plate processing method for bamboo material, which is characterized by expanding an arc-shaped bamboo material into a flat plate shape by deforming the portion . 2. A node is removed, and at least a part is cut vertically.
Spread outward in the vertical direction on the outer surface of the cut bamboo material
Engraving a plurality of deformation grooves, the deformation grooves are
The opening angle α of both sidewalls is defined as the central angle α between the adjacent deformation grooves.
Form at the same angle and cut only the groove bottom into a narrow valley width
As a result, a thin plate-like continuous portion is formed on the inner circumference of the bamboo material.
Forming a minute portion and deforming the thin plate-like continuous portion
Therefore, it is characterized by expanding the arc-shaped bamboo material into a flat plate shape.
Flat plate processing method of bamboo that.