JP5248949B2 - Wood molding method - Google Patents

Description

  The present invention relates to a method for forming wood, in which wood shaped from raw wood is compression-molded into a predetermined shape.

  In recent years, natural wood has attracted attention. Since wood has various grain patterns, individual differences occur depending on the location of the raw wood, and the individual differences are the individuality of each product. In addition, scratches and changes in color caused by long-term use may also have a unique texture and may be familiar to the user. For these reasons, wood has been attracting attention as a material that can produce unique and tasty products that are not found in products using synthetic resins and light metals, and its molding technology is also making rapid progress.

  Conventionally, as a technique for forming such wood, after compressing a piece of water softened and softened, and slicing the wood substantially parallel to the compression direction to obtain a plate-like primary fixed product, this primary fixed product is heated and absorbed by water. There is known a technique of forming a predetermined three-dimensional shape while performing the process (for example, see Patent Document 1). There is also known a technique in which a piece of wood compressed in a softened state is temporarily fixed, and this wood is put into a mold and recovered to mold (for example, see Patent Document 2).

Japanese Patent No. 3078452 JP-A-11-77619

  However, in the above-described prior art, when a node is present in the wood to be molded, the portion of the node has high hardness, and a problem such as buckling may occur by applying a compressive force. At the time when the shape was taken, it had to be scrapped.

  This invention is made | formed in view of the above, Comprising: It aims at providing the shaping | molding method of the timber which can shape | mold even if the timber shape | molded from the raw wood has a node.

  In order to solve the above-described problems and achieve the object, a wood molding method according to the present invention is a wood molding method in which a compression force is applied to wood using a pair of molds. The wood is formed from the raw wood so that the wood has a fiber direction substantially perpendicular to the relative moving direction of the pair of molds in a state where the wood is arranged at a predetermined position between the pair of molds. A cutting step for cutting, a cutting step for cutting a part of the node when a node having a fiber direction intersecting the fiber direction is present in the wood formed by the shaping step, and the cutting step The wood, part of which has been cut, is placed at the predetermined position between the pair of molds in a steam atmosphere at a higher temperature and pressure than the atmosphere, and the placed wood is sandwiched between the pair of molds. A compression process for applying a compression force And features.

  The wood forming method according to the present invention is characterized in that, in the above-mentioned invention, the cutting step is such that the thickness of the node portion is equal to or less than the thickness after compression in the peripheral portion of the node.

  The wood molding method according to the present invention is characterized in that, in the above invention, at least one of the pair of molds is provided with an elastic member on a surface in contact with the wood.

  In the wood molding method according to the present invention, in the above invention, one mold of the pair of molds has a convex part, and the other mold has a concave part having a shape corresponding to the convex part. And the said elastic member is provided in the said recessed part, It is characterized by the above-mentioned.

  According to the present invention, the wood body is attached to the wood shaped from the raw wood so as to have a fiber direction substantially perpendicular to the relative movement direction of the pair of molds in a state of being arranged at a predetermined position between the pair of molds. When there is a node having a fiber direction intersecting with the fiber direction, compression is performed after cutting the node portion, so that it is not necessary to apply the same compressive force as that of the main body to the node portion. Therefore, even if the wood shaped from the raw wood has a knot, it can be molded.

  The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described below with reference to the accompanying drawings. The drawings referred to in the following description are schematic, and when the same object is shown in different drawings, the dimensions, scales, and the like may be different.

  FIG. 1 is a flowchart showing an outline of processing of a wood forming method according to an embodiment of the present invention. First, wood having a predetermined shape is formed from raw wood (step S1). FIG. 2 is a diagram schematically showing the outline of this shaping process and showing the configuration of the shaped wood. In the shaping process, a substantially dish-shaped wood 2 is shaped by cutting or the like from raw wood 1 such as solid wood in an uncompressed state. The raw material 1 may be selected from cypress, hiba, paulownia, cedar, pine, cherry blossom, cocoon, ebony, shidan, bamboo, teak, mahogany, rosewood, and the like.

  FIG. 3 is a cross-sectional view taken along line AA in FIG. The wood 2 shown in FIG. 2 and FIG. 3 is curved with respect to the main plate portion 2a from each of a flat main plate portion 2a having a substantially rectangular surface and two long side portions facing each other on the surface of the main plate portion 2a. Two side plate portions 2b extending, and two side plate portions 2c extending curvedly with respect to the main plate portion 2a from each of two short side portions facing each other on the surface of the main plate portion 2a are provided. When forming the wood 2 from the raw wood 1, the wood 2 is placed in a state in which the wood 2 is disposed between a pair of dies (molds 11 and 12) used in the wood 2 compression step (step S5) described later. Is shaped so as to have a fiber direction L1 substantially perpendicular to the relative movement direction of the pair of molds. This point will be mentioned again when the compression process is described. The wood 2 has a node K penetrating in the thickness direction of the main plate portion 2a. The fiber direction L2 of the node K intersects the fiber direction L1 of the surrounding portion. FIG. 3 illustrates the case where the fiber direction L2 of the node K is substantially orthogonal to the fiber direction L1 of the surrounding portion.

  The wood 2 shaped as described above has a volume obtained by adding in advance a volume that is reduced by a compression process described later. 2 shows a case in which the grain G of the timber 2 is a grid material substantially parallel to the fiber direction of the timber 2, but the timber to be formed in the shaping process may be a grain material or a mouthpiece. .

  Subsequently, when a node having a fiber direction L2 intersecting the fiber direction L1 of the main body exists in the wood 2 (step S2, Yes), the thickness of the node K is reduced by cutting the node K. (Step S3). FIG. 4 is a diagram showing a configuration of the wood 2 after the cutting process, and is a cross-sectional view of the same cut surface as FIG. In FIG. 4, the portion of the node K is cut from the recessed side of the main plate portion 2a to make it thinner. Thus, it is easier to adjust the thickness by cutting only from one surface of the wood 2.

  By the way, it is more preferable that the thickness (wall thickness) of the portion of the node K after cutting is equal to or less than the thickness of the portion around the node K after compression. By adjusting the thickness of the node K in this manner, the compressive force in the thickness direction is hardly applied to the node K in the compression process described later. Accordingly, it is possible to prevent a problem such as buckling from occurring in the node K. In the following description, it is assumed that the thickness of the portion of the node K is cut to the thickness of the portion around the node K after compression in the cutting process.

  If there is no node having a fiber direction intersecting with the fiber direction of the main body 2 (step S2, No), the process proceeds to step S4 described later.

  In step S4, the shaped wood 2 is left in a steam atmosphere at a higher temperature and pressure than the atmosphere for a predetermined time to absorb moisture excessively, thereby softening the wood 2 (step S4). Water vapor has a temperature of about 100 to 230 ° C. and a pressure of about 0.1 to 3.0 MPa (megapascal). Such a water vapor atmosphere can be realized, for example, by using a pressure vessel. In the case of using a pressure vessel, the wood 2 is softened by leaving it in the pressure vessel. Instead of leaving the wood 2 softened by leaving it in a water vapor atmosphere, after supplying moisture to the surface of the wood 2, the wood 2 may be heated and softened by high-frequency electromagnetic waves such as microwaves. 2 may be boiled and softened.

  Thereafter, the softened wood 2 is compressed (step S5). In this compression step, the wood 2 is deformed into a predetermined three-dimensional shape by sandwiching the wood 2 with a pair of molds in the same steam atmosphere as in the softening step and applying a compression force. When the wood 2 is softened in the pressure vessel, the wood 2 may be subsequently compressed in the pressure vessel.

  FIG. 5 is a diagram illustrating an outline of the compression process and a configuration of a main part of a pair of molds used in the compression process. 6 is a cross-sectional view taken along the line BB of FIG. 5, and the cross section of the wood 2 is the same as that of FIG. 3. As shown in FIGS. 5 and 6, the wood 2 is sandwiched between a pair of molds 11 and 12 and a predetermined compression force is applied. As described in step S1, the wood 2 is placed between the molds 11 and 12, and the fiber direction L1 of the main body of the wood 2 is the relative movement direction of the molds 11 and 12 (see FIG. 5 and the vertical direction of FIG. 6).

  The mold 11 for applying a compressive force from above the wood 2 during the compression process is a cavity mold provided with a smooth surface-shaped recess 111 that abuts the surface of the wood 2 on which the wood 2 protrudes. Assuming that the curvature radius of the surface of the portion that curves from the main plate portion 2a to the side plate portion 2b and facing the mold 11 is RO, and the curvature radius of the surface of the recess 111 in contact with this surface is RA, The two radii of curvature RO and RA satisfy the relationship RO> RA.

  On the other hand, the mold 12 for applying a compressive force from the lower side of the wood 2 during the compression process is a core mold provided with a smooth surface-shaped convex portion 121 that abuts the surface of the wood 2 on which the wood 2 is depressed. is there. When the radius of curvature of the surface of the portion curved from the main plate portion 2a to the side plate portion 2b and facing the mold 12 is RI, and the curvature radius of the surface of the convex portion 121 in contact with this surface is RB, The two curvature radii RI and RB satisfy the relationship RI> RB.

  The molds 11 and 12 are clamped by a mold clamping device (not shown) after sandwiching the wood 2. FIG. 7 is a diagram illustrating a state in which the molds 11 and 12 that have been clamped are applying a compressive force to the wood 2, and the wood 2 has a three-dimensional shape corresponding to the gap between the mold 11 and the mold 12. It is a figure which shows the state which deform | transformed. When the state shown in FIG. 7 is reached, the thickness of the wood 2 is equal between the node K portion and the other portions. In the compression step, the compression force is continuously applied to the wood 2 for a predetermined time (1 to several tens of minutes, more preferably about 5 to 10 minutes) in the state shown in FIG.

  As described above, the portion of the node K receives almost no compressive force in the thickness direction until the state shown in FIG. 7 is reached after the molds 11 and 12 are clamped, but the wood 2 is deformed. In some cases, the main body of the wood 2 wraps under the node K, so that a slight compressive force is applied in the thickness direction. However, since the compressive force received in such a case is extremely small, the node K does not buckle.

  After the compression process is completed, the shape of the wood 2 is fixed by adding steam higher than the above-described steam to the periphery of the molds 11 and 12 while keeping the molds 11 and 12 clamped. (Step S6). When this immobilization process is performed in a pressure vessel, water vapor having a temperature higher than that in the compression step may be blown into the pressure vessel.

  Subsequently, the molds 11 and 12 and the wood 2 are opened to the atmosphere, and the wood 2 is dried (step S7). At this time, the molds 11 and 12 may be released from the clamped state, and the mold 11 or 12 may be separated from the wood 2 to promote drying of the wood 2. The thickness of the wood 2 after completion of drying is preferably about 30 to 50% of the thickness of the wood 2 before compression. This corresponds to the compression ratio of the wood 2 excluding the portion of node K being about 0.50 to 0.70. Hereinafter, the wood 2 finished up to the drying step is referred to as “wood 3”. FIG. 8 is a perspective view showing the configuration of the wood 3. The wood 3 has a main plate portion 3a and side plate portions 3b, 3c corresponding to the main plate portion 2a and the side plate portions 2b, 2c, respectively.

  Thereafter, the shape of the wood 3 is shaped while applying heat to the wood 3 in the atmosphere (step S8). FIG. 9 is a diagram schematically showing an outline of the heat shaping step. In the heating shaping step, the wood 3 is sandwiched between the molds 31 and 32 which are a pair of heating shaping dies.

  In FIG. 9, the mold 31 positioned above the wood 3 includes a smooth surface-shaped recess 311 that abuts the surface of the wood 3 from which the wood 3 protrudes. On the other hand, the mold 32 positioned below the wood 3 in FIG. 9 includes a smooth surface-shaped convex portion 321 that abuts against the surface of the wood 3 on which the wood 3 is depressed. The shape of the gap between the mold 31 and the mold 32 when the molds 31 and 32 are clamped corresponds to the shape of the wood 3 after shaping. The shape after shaping is desirably a shape obtained by slightly deforming the shape of the wood 3 before the heating shaping step. Thus, by preventing the shape of the wood 3 from changing greatly before and after the heat shaping step, it is possible to prevent problems such as cracking when the wood 3 is shaped.

  Inside the molds 31 and 32, heaters 33 and 34 for generating heat are respectively attached. The heaters 33 and 34 are connected to a control device 35 having a temperature control function, generate heat under the control of the control device 35, and apply heat to the molds 31 and 32, respectively. The control device 35 controls the heaters 33 and 34 so that the temperature of the molds 31 and 32 when the wood 3 is sandwiched is substantially constant at a high temperature of about 150 to 200 ° C.

  When the molds 31 and 32 heated by the heaters 33 and 34 are respectively clamped and the wood 3 is sandwiched for a predetermined time, a part of the sap inside the wood 3 oozes out to the surface of the wood 3. As a result, deep shades and gloss are produced on the surface.

  The time during which the wood 3 is held between the molds 31 and 32 in the heat shaping step and the mold temperature of the molds 31 and 32 are determined according to the characteristics of the wood 3 and the properties to be imparted to the processed wood 3. Just do it. The “characteristics of the wood 3” referred to here include not only the shape of the wood 3 but also the type of the raw wood 1 that is the raw material of the wood 3, the place of production, the growing environment, the growing state, and the like. Further, the “property to be imparted to the wood 3” includes the color and gloss of the surface of the wood 3 after molding, the strength of the wood 3 after molding, and the like.

  After the heat shaping process, the wood 3 is finished to the final shape (step S9). Specifically, the end face of the wood 3 is aligned by cutting, or a predetermined hole or notch is formed.

  FIG. 10 is a perspective view showing a configuration of a compressed wood product formed by the compressed wood product manufacturing method described above. The compressed wood product 4 shown in the figure is an exterior body that covers the front side (side facing the subject) of the digital camera, and the main plate portion 4a and the side plate portions 4b corresponding to the main plate portion 3a and the side plate portions 3b and 3c, respectively. 4c. The main plate portion 4a includes a cylindrical opening 41 that exposes the imaging unit of the digital camera, and a rectangular parallelepiped opening 42 that exposes the flash of the digital camera. The side plate portion 4b has a semi-cylindrical cutout 43 that exposes the shutter button.

  FIG. 11 is a perspective view showing a configuration of a digital camera whose front side is covered with the compressed wood product 4. A digital camera 100 shown in FIG. 1 includes an imaging unit 101, a flash 102, and a shutter button 103. The front side of the digital camera 100 where the imaging unit 101 and the flash 102 are exposed is covered with the compressed wood product 4. On the other hand, the back side of the digital camera 100 is covered with a compressed wood product 5 formed using the wood 2 in the same manner as the compressed wood product 4. Thus, when the compressed wood product shaped by the wood forming method according to the present embodiment is applied as an exterior body of a digital camera, it is more preferable that the wall thickness is about 1.6 to 2.0 mm.

  Note that the wood molding method according to the present embodiment can be applied to the case of forming tableware, various cases, flat or columnar building materials, etc., in addition to exterior bodies for electronic devices other than digital cameras. is there.

  According to the embodiment of the present invention described above, from the raw wood so as to have a fiber direction substantially perpendicular to the relative movement direction of the pair of molds in a state of being arranged at a predetermined position between the pair of molds. If the shaped wood has a node with a fiber direction that intersects the fiber direction of the wood body, the node part is cut and then compressed, so the same compression force as the body is not applied to the node part. Just do it. Therefore, even if the wood shaped from the raw wood has a knot, it can be molded.

  In addition, according to the present embodiment, when the part of the node is cut, the thickness of the node part is set to be equal to or less than the thickness after compression in the peripheral part of the node. It is possible to prevent the occurrence of problems such as these.

  FIG. 12 is a diagram showing another configuration of the mold used in the compression step of the wood forming method according to the present embodiment. The mold 13 shown in the figure is constituted by an elastic member 14 made of rubber or the like whose surface of the recess 131 abutting against the wood 2 is thin. By providing the elastic member 14 on the surface of the mold 13 in contact with the wood 2 in this way, even if a compressive force is applied to the node K portion, a part of the compressive force is applied to the elastic member 14. Can be absorbed. Therefore, it is possible to more reliably prevent the portion of the node K from causing problems such as buckling due to compression.

  The present invention should not be limited only by the above-described embodiment. For example, the present invention includes the case where the fiber direction of the nodes intersects with the fiber direction of the wood body at an angle of about 45 °. However, in this case, since the node portion is also compressed to some extent without causing buckling, it is not necessary to cut until the thickness of the node portion is equal to or less than the thickness after compression in the peripheral portion of the node. Absent. As is clear from this example, the present invention can include various embodiments and the like not described herein, and various modifications can be made without departing from the technical idea specified by the claims. It is possible to make design changes.

It is a flowchart which shows the outline | summary of the shaping | molding method of the timber which concerns on one embodiment of this invention. It is a figure which shows the outline | summary of the shaping process of the shaping | molding method of the wood which concerns on one embodiment of this invention. It is the sectional view on the AA line of FIG. It is a figure which shows the outline | summary of the cutting process of the shaping | molding method of the wood which concerns on one embodiment of this invention. It is a figure which shows the outline | summary of the compression process of the shaping | molding method of the wood which concerns on one embodiment of this invention. FIG. 6 is a sectional view taken along line B-B in FIG. 5. It is sectional drawing which shows the state which the deformation | transformation of wood was substantially completed in the compression process of the shaping | molding method of the wood which concerns on one embodiment of this invention. It is a perspective view which shows the structure of the wood after completion | finish of the drying process of the shaping | molding method of the wood which concerns on one embodiment of this invention. It is a figure which shows the outline | summary of the heating shaping process of the shaping | molding method of the wood which concerns on one embodiment of this invention. It is a perspective view which shows the structure of the compression wooden product shape | molded by the shaping | molding method of the timber which concerns on one embodiment of this invention. It is a perspective view which shows the structure of the digital camera which the compression wooden product shown in FIG. It is a figure which shows another structure of the metal mold | die used at the compression process of the shaping | molding method of the wood which concerns on one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Log 2, 3 Wood 2a, 3a, 4a Main plate part 2b, 2c, 3b, 3c, 4b, 4c Side plate part 4, 5 Compressed wood product 11, 12, 13, 31, 32 Mold 14 Elastic member 33, 34 Heater 35 Control device 41, 42 Opening 43 Notch 100 Digital camera 101 Imaging unit 102 Flash 103 Shutter button 111, 131, 311 Concave part 121, 321 Convex part G Wood grain K node

Claims (4)

A wood molding method for molding the wood by applying a compressive force to the wood using a pair of molds,
Forming the wood from the raw wood so that the wood has a fiber direction substantially perpendicular to the relative moving direction of the pair of molds in a state where the wood is disposed at a predetermined position between the pair of molds. Taking process,
A cutting step of cutting a part of the node when there is a node having a fiber direction intersecting the fiber direction in the wood shaped in the shaping step;
The wood obtained by cutting a part of the node in the cutting step is disposed at the predetermined position between the pair of molds in a steam atmosphere at a higher temperature and pressure than the atmosphere, and the disposed wood is disposed on the pair of metal molds. A compression process in which a compression force is applied by being sandwiched between molds;
A method for forming a wood, comprising: The cutting process includes
2. The method of forming wood according to claim 1, wherein the thickness of the node portion is set to be equal to or less than the thickness after compression in the peripheral portion of the node.   The method for molding wood according to claim 1 or 2, wherein at least one of the pair of molds is provided with an elastic member on a surface in contact with the wood. One mold of the pair of molds has a convex part, and the other mold has a concave part having a shape corresponding to the convex part,
The method for molding wood according to claim 3, wherein the elastic member is provided in the recess.

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