Wood drying apparatus and method for producing naturally dried wood

Abstract

The present invention provides a drying apparatus that can efficiently dry wood by evenly exposing each surface of the wood to sunlight, and a method for manufacturing naturally dried wood. [Solution] The drying apparatus includes a base installed on the upper side of the trolley 1. The base is composed of two rows of positioning member rows 3, each consisting of multiple positioning members 2 arranged in a continuous manner, spaced apart in the longitudinal direction of the wood. Each positioning member 2 has an inclined surface 4 that slopes vertically, and a step 5 is formed at the boundary between adjacent positioning members 2. The wood is positioned so as to be in contact with this step 5, and rotates so that different surfaces are exposed to sunlight before and after rotation.

Description

Technical Field

[0001] The present invention relates to a wood drying apparatus and a method for producing naturally dried wood that can improve productivity, prevent occurrence of uneven drying, and improve quality.

Background Art

[0002] Freshly felled trees from mountains contain a large amount of moisture inside, so they cannot be used as building materials as they are, and a drying step is required to remove internal moisture. Drying methods are broadly classified into natural drying and artificial drying.

[0003] Naturally dried wood is wood produced by drying in the sun using natural forces. Slow drying has the advantage of maintaining the color and luster of the wood, but generally requires a drying period of about one year from felling to shipment.

[0004] On the other hand, artificially dried wood is wood that is forcibly dried using special machinery, and the period required for drying can be shortened, so most of the wood in circulation is processed by artificial drying. In fact, 90% of timber for house construction is kiln-dried wood (KD wood) obtained by rapidly drying green wood (G wood), which is undried lumber that has not been subjected to drying treatment, with light oil. The heat treatment in this process causes lignin and cellulose contained in the wood to be degraded, and the color, luster and scent of the wood are lost.

[0005] From this point of view, naturally dried wood is advantageous in terms of quality because wood resin and moisture gather in the central part, giving it viscosity, scent and excellent strength. However, when production of naturally dried wood relies on manual labor, two workers are required to hold the wood, rotate the four sides of the wood to dry it in the sun to produce air-dried wood (AD wood). This is heavy labor and has the problem of extremely low productivity. An example of technology related to wood drying methods is disclosed in Patent Document 1.

Prior Art Literature

Patent Literature

[0006] [Patent Document 1] Japanese Patent Publication No. 2005-96234 [Overview of the project] [Problems that the invention aims to solve]

[0007] As mentioned above, natural drying is superior for ensuring the quality of dried lumber, and it is also advantageous in that it does not require energy for drying, unlike artificial drying which uses fuel. However, the problem is that it requires manpower and takes a long time from felling to shipment. Therefore, there is a need for a method to produce naturally dried lumber in a short period of time without requiring manpower by mechanizing this natural drying process. Furthermore, when mechanizing the natural drying process, it is necessary to dry the entire piece of wood evenly, as uneven drying will lead to a decrease in quality.

[0008] This invention has been made in consideration of these circumstances, and aims to provide a wood drying apparatus and a method for producing naturally dried wood that can produce naturally dried wood in a short period of time without human intervention, prevent uneven drying of the wood, and allow the entire piece of wood to be dried evenly. [Means for solving the problem]

[0009] To solve the above problems, the present invention provides a drying apparatus that includes a base installed on the upper side of a trolley, and rotates the wood mounted on the base to change the side exposed to sunlight, thereby drying the wood by evenly exposing each side of the wood to sunlight. The base is configured with two rows of positioning members, each consisting of multiple positioning members arranged in a continuous manner, spaced apart in the longitudinal direction of the wood, and each positioning member has an inclined surface that is tilted in the vertical direction, with a step formed at the boundary between adjacent positioning members, and the wood is positioned so as to be in contact with this step, so that different sides are exposed to sunlight before and after rotation.

[0010] With the above configuration, the wood mounted on the base is rotated to change the side exposed to sunlight, allowing sunlight to be evenly distributed to each side of the wood for drying, thus enabling the production of naturally dried lumber in a short period of time without manual labor. The purpose of rotating the wood is to evenly distribute sunlight to each side of the lumber, which has a rectangular shape. However, if the position of the wood on the base shifts during this rotation, it becomes impossible to evenly distribute sunlight to each side of the wood. To prevent this from happening, in this invention, the wood is positioned so as to be in contact with the steps of the positioning member row, so that the wood can be rotated without shifting position. Therefore, uneven drying of the wood can be prevented.

[0011] Furthermore, the drying apparatus according to the present invention preferably further comprises at least one of the following configurations (a) to (d). (a) A pin installed below the piece of wood placed on the positioning member, which raises the piece of wood away from the positioning member. (b) A focusing lens for concentrating sunlight, and an optical fiber for irradiating the wood from below the base through the light obtained from the focusing lens. (c) A vapor-deposited mirror that reflects sunlight and is installed on the bottom side of the trolley, shining reflected light from below onto the wood. (d) A light-transmitting transparent resin member forming the positioning member.

[0012] In particular, when the configuration with the pins described in (a) above is used, the surface of the wood that comes into contact with the positioning member becomes difficult to dry. However, by raising the wood placed on the positioning member using the pins installed on the lower side of the wood, and moving it away from the positioning member, ventilation can be improved, and the drying of the wood can be promoted. Furthermore, even when the configurations in (b) to (d) are adopted, it becomes possible to effectively irradiate the lower side of the wood with light, thereby improving drying efficiency.

[0013] Furthermore, the drying apparatus according to the present invention preferably further comprises at least one of the following configurations (e) or (f). (e) A photoelectric sensor for detecting misalignment of the wood installed on the positioning member. (f) An AI camera that recognizes the position of a cart loaded with lumber.

[0014] Another aspect of the present invention is a method for producing naturally dried lumber using the above-described drying apparatus, characterized in that the lumber mounted on the base installed on the upper side of the trolley is rotated to change the side exposed to sunlight, thereby drying the lumber by exposing each side of the lumber to sunlight evenly.

[0015] Furthermore, the method for producing naturally dried timber according to the present invention preferably further includes at least one of the following steps (a) to (d) that corresponds to the configuration of the drying apparatus. (a) A step of raising the wood by a pin installed on the lower side of the wood placed on the positioning member, so that the wood is separated from the positioning member. (b) Light obtained from a focusing lens that concentrates sunlight Optical fiber This process involves passing light through a device and irradiating the wood from below the base to dry the parts of the wood that are not easily exposed to sunlight. (c) a step of drying the lower side of the wood by applying reflected light from the lower side of the wood with a vapor-deposited mirror that reflects sunlight, the vapor-deposited mirror being disposed on the bottom side of the truck and configured to apply reflected light from the lower side of the wood. (d) a step of drying the lower side of the wood with light transmitted through a transparent resin member forming the positioning member.

[0016] Furthermore, the method for producing naturally dried wood according to the present invention preferably further includes at least one step corresponding to the configuration provided in the drying device, among the following steps (e) or (f). (e) a step of detecting positional displacement of the wood by a photoelectric sensor that detects positional displacement of the wood disposed on the positioning member, to prevent positional displacement of the wood and dry the wood. (f) a step of recognizing the position of the truck loaded with wood by an AI camera that recognizes the position of the truck loaded with wood, to dry the wood. Effects of the Invention

[0017] According to the present invention, it is possible to realize a wood drying device and a method for producing naturally dried wood, which can produce naturally dried wood in a short period of time without manual labor, prevent occurrence of uneven drying in wood, and uniformly dry the entire wood. Brief Description of the Drawings

[0018] [Figure 1] It is a diagram showing the structure of a truck of a drying device used for loading and drying wood. [Figure 2] It is an overall view of the wood drying device. [Figure 3] It is a detailed diagram showing a state where a plurality of pieces of wood are loaded on a positioning member. [Figure 4] It is a diagram explaining the function of the AI camera. [Figure 5] It is a diagram explaining the function of the photoelectric sensor. [Figure 6] It is a diagram explaining the rotating operation of wood. [Modes for carrying out the invention]

[0019] The method for producing naturally dried lumber according to the present invention will be described below based on its embodiments. The present invention relates to a method for producing naturally dried lumber, which involves rotating lumber mounted on a base installed on the upper side of a trolley to change the side exposed to sunlight, thereby drying the lumber by evenly exposing each side of the lumber to sunlight. Figure 1 shows the structure of the trolley of the drying apparatus used to mount and dry the lumber when carrying out the method for producing naturally dried lumber according to the present invention. Figure 1(a) is a perspective view of the trolley, Figure 1(b) is a top view of the trolley, Figure 1(c) is a front view of the trolley, and Figure 1(d) is a side view of the trolley.

[0020] The base of the trolley 1 is constructed of two rows of positioning members 3, each consisting of multiple positioning members 2 arranged in a continuous fashion, spaced apart along the longitudinal direction of the lumber. Each positioning member 2 has an inclined surface 4 that slopes vertically, and a step 5 is formed at the boundary between adjacent positioning members 2. The lumber is positioned so as to be in contact with this step 5, and rotates so that different surfaces are exposed to sunlight before and after rotation. Since the trolley 1 is movable, it can carry and transport the lumber. When it is time to start drying the lumber by exposing it to sunlight, the drying apparatus equipped with the trolley 1 is pulled out of the building where it was stored, and the drying process begins.

[0021] Figure 2 is an overall view of the wood drying apparatus. Multiple pieces of wood 6 are mounted on a positioning member 2, and an arm 7 for rotating the wood 6 is attached above the wood 6. The arm 7 is moved vertically and forward and backward in the direction of travel by a Z-axis robot 8 and a Y-axis robot 9. An AI camera 11 is attached to the drying device. Details of how the wood 6 is rotated by the arm 7 will be described later. The pieces of wood 6 are square timbers, with a maximum length of 4m and a weight of approximately 30kg, and are placed at intervals of 100mm. The wood 6 is rotated four times a day, every two hours of sun drying time.

[0022] Figure 3 is a detailed view of the state in which multiple pieces of wood 6 are mounted on the positioning member 2. Figure 3(a) is an overall view, and Figure 3(b) is a detailed view of a part thereof. The positioning member 2 has an inclined surface 4 that is tilted in the vertical direction, and a step 5 is formed at the boundary between adjacent positioning members 2. The wood 6 is positioned so as to be in contact with this step 5.

[0023] The wooden piece 6, placed on the positioning member 2, can be raised by a pin 12 installed on the lower side of the wooden piece 6, thereby separating the wooden piece 6 from the positioning member 2. This ensures ventilation for the positioning member 2. Figure 3 shows the state where the pin 12 has risen and the wooden piece 6 is separated from the positioning member 2. This state is maintained when the wooden piece 6 is stationary and exposed to sunlight. However, when the wooden piece 6 is rotated by the arm 7, the pin 12 descends, and the wooden piece 6 comes into contact with the surface of the positioning member 2.

[0024] The raising and lowering of pin 12 can be achieved by the rack and pinion mechanism 13. When the shaft 15 is attached to the manual handle 14 and the pinion is turned clockwise, the teeth of the pinion mesh with the teeth of the rack, so the rotational motion is converted into linear motion, causing the rack to rise, and consequently the pin 12 to rise. When the pinion is turned counterclockwise, the rack descends, and consequently the pin 12 descends.

[0025] The sunlight focused by the focusing lens 16 is guided by the optical fiber 17, passes through the positioning member 2, and irradiates the wood 6 from below. In addition, a vapor-deposited mirror 18 that reflects sunlight is installed on the bottom of the trolley 1, and the reflected light is irradiated from below the wood 6 to dry the lower side of the wood 6. Since the positioning member 2 is made of a transparent resin that transmits light, the lower side of the wood 6 can be dried by the light that passes through the positioning member 2.

[0026] The functions of the AI ​​camera 11 will be explained based on Figure 4. Figure 4(a) shows the installation of the AI ​​camera 11, and Figure 4(b) shows an example of how the arrangement of the wood 6 is detected by the AI ​​camera 11. Even if the arrangement of the wood 6 becomes disordered due to a robot malfunction or other reasons, the AI ​​camera 11 can detect the situation and restore it to its normal state.

[0027] The function of the photoelectric sensor 19 will be explained based on Figure 5. Figure 5(a) shows the installation of the photoelectric sensor 19, and Figure 5(b) shows an example of how the arrangement of the wood 6 is detected by the photoelectric sensor 19. If the arrangement of the wood 6 is normal, light will pass through the photoelectric sensors 19. However, if there is an abnormality in the arrangement of the wood 6, the light will be blocked by the wood 6 and the photoelectric sensors 19 will not be able to receive light. This allows the abnormal condition to be detected, and the system can be restored to a normal state.

[0028] Based on Figure 6, the rotational motion of the wood 6 will be explained. As shown in Figure 6(a), the arm 7 lowers along its Z-axis and enters the underside of the wood 6, as shown in Figure 6(b). From this position, as shown in Figure 6(c), the arm 7 rises, causing the wood 6 to roll onto the adjacent positioning member 2 and be positioned in contact with the step 5 of the positioning member 2. In this way, the wood 6 is precisely positioned during its rotation, allowing for accurate identification of the surface exposed to sunlight and preventing uneven drying. This operation is repeated for each piece of wood 6. During the rotation of the wood 6, the pin 12 descends, and the wood 6 is in contact with the positioning member 2; therefore, in Figure 6, the pin 12 shown in Figure 3 is omitted from the diagram.

[0029] As explained above, the present invention aims to prevent uneven drying of wood when mechanizing the natural drying process by employing a method to prevent positional displacement during the rotation of the wood, and by employing a means to irradiate parts that are not directly exposed to sunlight with light derived from sunlight. Therefore, all the light used for drying the wood is derived from sunlight. As a result, it does not cause quality deterioration due to heat treatment as in the case of artificial drying, and it is a groundbreaking method in that it can shorten the drying time while ensuring the high quality of the dried wood. With the above drying method, the drying process can be completed and the wood can be shipped in about 3 months, which is a significant improvement in productivity considering that it conventionally took about 1 year to ship the wood. [Industrial applicability]

[0030] The present invention can be widely used as a wood drying apparatus and a method for producing naturally dried lumber, which can produce naturally dried lumber in a short period of time without requiring human intervention, prevent uneven drying of the wood, and allow the entire piece of wood to be dried evenly. [Explanation of Symbols]

[0031] 1 cart 2 Positioning member 3 Positioning member row 4 Slope 5 steps 6 wood 7 Arms 8 Z-axis robot 9 Y-axis robot 10 Yagura 11 AI Cameras 12 pins 13. Rack and pinion mechanism 14 Manual handle 15 shafts 16. Focusing lens 17 Optical Fiber 18 Vapor-deposited mirrors 19 Photoelectric Sensor 20. Single-axis robot

Claims

1. A drying device comprising a base installed on the upper side of a trolley, which rotates the wood placed on the base to change the side exposed to sunlight, thereby drying the wood by exposing each side of the wood to sunlight evenly. The base is constructed by forming two rows of positioning members, each row having a gap between them in the longitudinal direction of the wood, with multiple positioning members arranged in a continuous manner. Each of the positioning members has an inclined surface that slopes vertically, and a step is formed at the boundary between adjacent positioning members. The drying apparatus is characterized by positioning the wood so that it is in contact with this step, and by rotating so that different surfaces are exposed to sunlight before and after rotation.

2. Furthermore, the drying apparatus according to claim 1 is characterized by comprising at least one of the following configurations (a) to (d). (a) A pin installed below the piece of wood placed on the positioning member, which raises the piece of wood away from the positioning member. (b) A focusing lens for concentrating sunlight, and an optical fiber that irradiates light onto the wood from below the base through the light obtained from the focusing lens. (c) A vapor-deposited mirror that reflects sunlight and is installed on the bottom side of the trolley, shining reflected light from below onto the wood. (d) A light-transmitting transparent resin member that forms the positioning member.

3. Furthermore, the drying apparatus according to claim 1 or 2 is characterized by comprising at least one of the following configurations (e) or (f). (e) A photoelectric sensor for detecting misalignment of the wood installed on the positioning member. (f) An AI camera that recognizes the position of a cart loaded with lumber.

4. A method for producing naturally dried lumber using the drying apparatus described in claim 1, characterized in that the lumber mounted on the base installed on the upper side of the trolley is rotated to change the side exposed to sunlight and to dry the lumber by exposing each side of the lumber to sunlight evenly.

5. A method for producing naturally dried wood according to claim 4, using the drying apparatus described in claim 1, characterized in that it includes at least one of the following steps (a) to (d) that corresponds to the configuration of the drying apparatus. (a) A step of raising the wood by a pin installed on the lower side of the wood placed on the positioning member, so that the wood is separated from the positioning member. (b) A process in which light obtained from a focusing lens that concentrates sunlight is passed through an optical fiber and the light is shone onto the wood from below the base, thereby drying the parts of the wood that are not easily exposed to sunlight. (c) A process of drying the lower side of the wood by shining reflected light from below the wood using a vapor-deposited mirror that reflects sunlight, which is installed on the bottom side of the trolley and shines reflected light on the wood from below. (d) A step of drying the lower side of the wood by light passing through the transparent resin member that forms the positioning member.

6. A method for producing naturally dried wood according to claim 4 or 5, using the drying apparatus described in claim 1, characterized in that it includes at least one of the following steps (e) or (f) that corresponds to the configuration of the drying apparatus. (e) A step of preventing misalignment of the wood and drying the wood by detecting misalignment of the wood using a photoelectric sensor that detects misalignment of the wood installed on the positioning member. (f) A process of drying wood by recognizing the position of a cart loaded with wood using an AI camera that recognizes the position of the cart loaded with wood.

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