Wood combustion production device, its control method, and wood fuel production method

Abstract

To provide a woody fuel manufacturing apparatus capable of producing woody fuel at a lower cost.SOLUTION: A woody fuel manufacturing apparatus includes a cylinder, a screw configured to feed a woody material supplied to an inside of the cylinder forward, and a movement restriction part configured to restrict a frontward movement of the woody material discharged from a front end of the cylinder. The cylinder includes a mixing region disposed inside the cylinder and frontward to the front end of the screw, for mixing, by the screw, the woody material whose movement is restricted by the movement restriction part. The movement restriction part is at least three brake faces alienated with each other in a circumferential direction of the cylinder, the at least three brake faces configured to press the woody material discharged from the cylinder inward in a radial direction of the cylinder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wood fuel production device and a control method thereof. [Background technology]

[0002] Wood fuel is produced using wood raw materials, such as wood waste materials such as scraps, sawdust, felled wood, and demolition materials. Wood fuels produced include firewood, chips, and pellets.

[0003] Patent Document 1 discloses a plant biomass solidification device that compresses plant biomass as a material fed into a material supply chamber and extrudes it into a cylindrical sleeve that communicates with the material supply chamber to form a cylindrical solid. Patent Document 2 discloses an extrusion molding machine for producing wood pellets that does not require drying treatment of the wood raw material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5611001 Specification [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-940 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it is difficult to say that the production of wood fuel using existing production equipment is cost-effective.

[0006] An object of the present invention is to provide a wood fuel production apparatus and a control method thereof that can produce wood fuel at lower cost. [Means for solving the problem]

[0007] According to a first aspect of the present invention, A cylinder; a screw that sends the wood raw material supplied inside the cylinder forward; a movement limiting section that limits the forward movement of the wood raw material discharged from the front end of the cylinder, The cylinder has a kneading region inside the cylinder and forward of the front end of the screw, for kneading the wood raw material, the movement of which is restricted by the movement restricting portion, with the screw, A wood fuel production device is provided in which the movement restricting portion has at least three braking surfaces arranged at a distance from each other in the circumferential direction of the cylinder, each of which presses the wood raw material discharged from the cylinder radially inward of the cylinder.

[0008] According to a second aspect of the present invention, A method for controlling a wood fuel production apparatus that produces wood fuel using wood raw materials, comprising: The wood fuel production device includes: A cylinder; a screw that sends the wood raw material supplied inside the cylinder forward; a movement limiting portion that limits the forward movement of the wood raw material discharged from the front end of the cylinder; a control unit; The cylinder has a kneading region inside the cylinder and forward of the front end of the screw, for kneading the wood raw material, the movement of which is restricted by the movement restricting portion, with the screw, The movement limiting portion has at least three braking surfaces arranged at a distance from each other in the circumferential direction of the cylinder, each of which is movable in the radial direction of the cylinder and presses the wood raw material discharged from the cylinder radially inward of the cylinder, A control method is provided in which the control unit changes the radial positions of the at least three braking surfaces of the cylinder based on at least one of the load of the motor that rotates the screw, the temperature inside the cylinder, and the humidity inside the cylinder. [Effects of the Invention]

[0009] According to the wood fuel production apparatus and control method of the present invention, wood fuel can be produced at lower cost. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a wood fuel production apparatus according to an embodiment. [Figure 2] FIG. 2 is a block diagram of the configuration relating to the electrical mechanism of the wood material manufacturing apparatus according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the cylinder, screw, braking piece, and hopper provided in the wood fuel production device of the embodiment, taken along a plane that includes the center axis of the cylinder and extends in the vertical direction. [Figure 4] Fig. 4(a) is a perspective view of the front end of the screw, and Fig. 4(b) is a plan view of the front end of the screw as seen from the axial front side. [Figure 5] FIG. 5 is a perspective view of the vicinity of the front end of the screw. [Figure 6] Fig. 6(a) is a perspective view of the braking piece. Fig. 6(b) is a plan view of the braking piece. Fig. 6(c) is a cross-sectional view of the braking piece taken along line CC in Fig. 6(b). Fig. 6(d) is a cross-sectional view of the braking piece taken along line DD in Fig. 6(b). [Figure 7] Figures 7(a) and 7(b) are plan views of the cylinder and three braking pieces as seen from the axial front side. Figure 7(a) shows a state in which the braking surface of each of the three braking pieces is located on an extension of the inner circumferential surface of the cylinder. Figure 7(b) shows a state in which the braking surface of each of the three braking pieces is located radially inward of the extension of the inner circumferential surface of the cylinder. [Figure 8] FIG. 8 is a flowchart showing the process of a wood fuel production method using a wood fuel production device according to an embodiment. [Figure 9]Figures 9(a) to 9(d) are explanatory diagrams showing the state of the wood raw material as viewed from the axial front during wood fuel production. Figure 9(a) shows the state of the wood raw material in the screw region of the cylinder. Figure 9(b) shows the state of the wood raw material near the front end of the screw in the screw region of the cylinder. Figure 9(c) shows the state of the wood raw material in the non-screw region. Figure 9(d) shows the state of the wood raw material located in the braking section outside the cylinder. [Figure 10] FIG. 10 is an explanatory diagram for explaining the kneading process in the non-screw region. [Figure 11] 11(a) and 11(b) are perspective views of kneading pieces of modified examples. [Figure 12] 12(a) and 12(b) are explanatory diagrams showing the operation of the braking pieces of the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment> A wood fuel production device 100 according to an embodiment of the present invention will be described with reference to FIGS.

[0012] [Structure of wood fuel production device 100] As shown in FIGS. 1, 2, and 3, the wood fuel production device 100 mainly comprises a cylinder 10, a screw mechanism 20, a movement limiting mechanism 30, a hopper 40, and a control unit 50.

[0013] In the following description, the central axis X of the cylinder 10 10 The direction in which the central axis X extends is the axial direction of the wood fuel production device 100, with the side where the hopper 40 is located being the rear side and the side where the movement limiting mechanism 30 is located being the front side. 10 The rotation direction around the central axis X is the circumferential direction of the wood fuel production device 100. 10 The radial direction from the center is the radial direction of the wood fuel production device 100.

[0014] [Cylinder 10] The cylinder 10 is a member that defines an internal space for processing wood raw materials (e.g., wood chips) that are used to produce wood fuel. In this embodiment, the cylinder 10 is made of ductile cast iron (FCD450). However, the cylinder 10 is not limited to this and may be made of any metal material, such as cast iron, iron, or steel.

[0015] The cylinder 10 has a central axis X 10 When the wood fuel production device 100 is installed on the floor, the central axis X 10 3, the cylinder 10 has a front end 10a, a rear end 10b, an outer circumferential surface 10So, and an inner circumferential surface 10Si. The axial length of the cylinder 10 can be, for example, about 700 mm to 1500 mm. The inner diameter d of the cylinder 10 is 10 In this embodiment, the inner diameter d of the cylinder 10 is set to about 40 mm to 80 mm. 10 is constant throughout the entire area from the front end 10a to the rear end 10b.

[0016] An opening 10A is provided near the rear end 10b (FIG. 3) of the cylinder 10. The opening 10A is provided so as to open upward when the wood fuel production device 100 is placed on the floor.

[0017] An internal space SP surrounded by the inner circumferential surface 10Si of the cylinder 10 10 The internal space SP is a processing space for crushing, compressing, kneading, and other processes (described in detail below) on wood chips, which are the raw material for wood fuel. 10 is a cylindrical space.

[0018] The surface roughness (roughness, surface roughness) of the inner peripheral surface 10Si of the cylinder 10 is determined by the screw 21 (more specifically, the screw shaft 211 and the screw blade 212 of the screw 21) located at the same position in the axial direction and the screw region 10 facing the screw blade 212 in the radial direction. A1In FIG. 3, the arithmetic mean roughness Ra (JIS B 0601-2001) can be expressed as approximately 50a to 100a in the standard progression, and / or the ten-point mean roughness Rz (JIS B 0601-2001) can be expressed as approximately 200z to 400z in the standard progression (hereinafter, when the arithmetic mean roughness Ra is expressed as X to Y in the standard progression, it will be written as "Ra = X to Y", and when the ten-point mean roughness Rz is expressed as X to Y in the standard progression, it will be written as "Rz = X to Y"). On the other hand, in the non-screw region 10 where the screw shaft 211 and the screw blade 212 are not present at the same position in the axial direction and are not opposed to the screw blade 212 in the radial direction, A2 In the non-screw region 10 (FIG. 3, an example of the kneading region), the surface roughness of the inner circumferential surface 10Si of the cylinder 10 can be approximately Ra=3.2a to 25a and / or Rz=12.5z to 100z. A2 In screw region 10 A1 Smaller than in the non-screw area 10 A2 is screw area 10 A1 Located in front of the.

[0019] [Screw mechanism 20] The screw mechanism 20 is inserted into the internal space SP of the cylinder 10. 10 1, 2, and 3, the screw mechanism 20 has a screw 21 and a drive unit 22.

[0020] Screw 21 has rotation axis X 21 (Fig. 3) and has a rotation axis X 21 The central axis X of the cylinder 10 10 When the cylinder 10 is aligned with the internal space SP 10The screw 21 is supported in a cantilevered manner with its rear end as a support end. In this embodiment, the screw 21 is made of ductile cast iron (FCD350-500). However, the screw 21 is not limited to this and may be made of any metal material, such as cast iron, iron, steel, or chromium-molybdenum steel. The screw 21 has a screw shaft 211, screw blades 212, and kneading pieces 213. The screw shaft 211, screw blades 212, and kneading pieces 213 may be cast as a single unit. The tip portion 21s or kneading pieces 213, which will be described later, may be made of alloy tool steel (SKD-11, etc.) and hardened.

[0021] The screw shaft 211 is the rotation axis X 21 The front end surface 211Sa is a cylindrical shape having a center at the rotation axis X, and has a front end surface 211Sa, a rear end surface 211Sb, and an outer peripheral surface 211So. 21 The shape of the front end surface 211Sa as viewed in the axial direction is a flat surface extending in a plane perpendicular to the rotation axis X. 21 The surface roughness of the front end face 211Sa may be approximately Ra=50a to 100a and / or Rz=200z to 400z. The surface roughness of the outer circumferential face 211So may be approximately Ra=3.2a to 25a and / or Rz=12.5z to 100z. In this embodiment, the surface roughness of the front end face 211Sa is greater than the surface roughness of the outer circumferential face 211So.

[0022] The screw blade 212 is provided in a spiral shape on the outer peripheral surface 211So of the screw shaft 211. When viewed from the rear side to the front side in the axial direction, the screw blade 212 extends toward the front side while revolving clockwise.

[0023] In this embodiment, the pitch of the screw blades 212 gradually decreases in three stages from the rear side to the front side in the axial direction. A1 In the first region 21, the pitch of the screw blade 212 is the first pitch p1. A1 the second region 21 in front of A2In the second region 21, the pitch of the screw blades 212 is a second pitch p2 that is smaller than the first pitch p1. A2 the third region 21 in front of A3 In the first region 21, the pitch of the screw blades 212 is a third pitch p3 that is smaller than the second pitch p2. A1 , second area 21 A2 , 3rd area 21 A3 The axial length of each of the first pitch p1, the second pitch p2, and the third pitch p3 may be set appropriately. The third pitch p3 may be half or less of the first pitch p1.

[0024] Of the outer surfaces of the screw blade 212, the surface facing forward is the front surface 212Sa, the surface facing rearward is the rear surface 212Sb, and the surface facing radially outward is the outer circumferential surface 212So. The surface roughness of the front surface 212Sa and the rear surface 212Sb may be approximately Ra=3.2a to 25a and / or Rz=12.5z to 100z. The surface roughness of the outer circumferential surface 212So may be approximately Ra=50a to 100a and / or Rz=200z to 400z. In this embodiment, the surface roughness of the outer circumferential surface 212So is greater than the surface roughness of the front surface 212Sa, the rear surface 212Sb, and the outer circumferential surface 211So of the screw shaft 211. Note that the screw region 10 of the inner circumferential surface 10Si of the cylinder 10 A1 The surface roughness at the front surface 212Sa of the screw blade 212, the rear surface 212Sb of the screw blade 212, and the outer circumferential surface 211So of the screw shaft 211 are also greater than the surface roughness at the front surface 212Sa of the screw blade 212, the rear surface 212Sb of the screw blade 212, and the outer circumferential surface 211So of the screw shaft 211.

[0025] Rotation axis X 21As shown in FIG. 3, a cross section of the screw flight 212 cut along a plane including the arrows 212A and 212B has a first side SD1, a second side SD2, and a third side SD3. The first side SD1 is a side defined by cutting the front surface 212Sa and is a straight line extending in the radial direction. The length of the first side SD1 may be approximately 20 mm to 40 mm. The second side SD2 is a side defined by cutting the rear surface 212Sb and is a straight line extending in the radial direction. The length of the second side SD2 may be approximately 20 mm to 40 mm. The third side SD3 is a side defined by cutting the outer circumferential surface 212So and is a straight line extending in the axial direction. The length of the third side SD3 may be approximately 10 mm to 20 mm. The lengths of the first side SD1 and the second side SD2 may be the same. The length of the third side SD3 may be ¼ or more, ⅓ or more, or ½ or more of the length of the first side SD1 (and / or the second side SD2).

[0026] The kneading pieces 213 are provided at the front end of the screw 21 and protrude forward beyond the front end of the screw shaft 211. The kneading pieces 213 knead the wood raw material, the forward movement of which is restricted by a movement restricting mechanism 30, which will be described later.

[0027] 4(a) and 4(b), the kneading piece 213 has a fan-shaped plate shape when viewed in the axial direction, and has a front surface 213Sa, a rear surface 213Sb, an outer circumferential surface 213So, and a tip surface 213St. The thickness (axial dimension) of the kneading piece 213 gradually increases toward the outside in the radial direction, and is greatest slightly inside the outer circumferential surface 213So.

[0028] The front surface 213Sa is continuous with the front surface 212Sa of the screw flight 212 and extends further forward from the terminal end of the front surface 212Sa. The rear surface 213Sb is continuous with the rear surface 212Sb of the screw flight 212 and extends further forward from the terminal end of the rear surface 212Sb. The outer circumferential surface 213So is continuous with the outer circumferential surface 212So of the screw flight 212 and extends further forward from the terminal end of the outer circumferential surface 212So. The surface roughness of the front surface 213Sa may be approximately Ra = 50a to 100a and / or Rz = 200z to 400z. The surface roughness of the rear surface 213Sb may be approximately Ra = 3.2a to 25a and / or Rz = 12.5z to 100z. The surface roughness of the outer circumferential surface 213So may be approximately Ra=50a to 100a and / or Rz=200z to 400z. In this embodiment, the surface roughness of the front surface 213Sa is greater than the surface roughness of the outer circumferential surface 211So of the screw shaft 211.

[0029] The tip surface 213St is a surface of the kneading piece 213 located on the opposite side to the connection portion with the screw blade 212. 21 The tip end surface 213St is a flat surface extending in a plane that includes the tip end surface 213St and extends in the radial direction. The shape of the tip end surface 213St when viewed in the circumferential direction is approximately rectangular. The surface roughness of the tip end surface 213St can be approximately Ra=50a to 100a and / or Rz=200z to 400z.

[0030] The connecting portion between the front surface 213Sa and the tip surface 213St is the edge EG. The edge EG extends linearly in the radial direction. The portion of the kneading piece 213 near the edge EG is disposed forward of the front end surface 211Sa of the screw shaft 211. The portion of the kneading piece 213 located forward of the front end surface 211Sa is the protruding portion 213P.

[0031] In this embodiment, the front faces 213Sa of the kneading pieces 213 are inclined with respect to both a plane perpendicular to the axial direction and a plane perpendicular to the circumferential direction. Specifically, the front faces 213Sa shift forward as they proceed counterclockwise when viewed from the front in the axial direction. In this embodiment, the screw 21 rotates clockwise when viewed from the front in the axial direction (described later). Therefore, the kneading pieces 213 protrude forward more toward the downstream side in the rotation direction of the screw 21. This allows the non-screw region 10 A2 This allows for better kneading of the wood raw material (described in detail below).

[0032] In this embodiment, the front surfaces 213Sa of the kneading pieces 213 are inclined so as to shift forward as they move radially outward. A2 This allows for better mixing of the wood raw material (described in detail later). In FIG. 4(a), the region of the front surface 213Sa near the outer peripheral surface 213So is inclined so as to shift rearward as it moves radially outward, but this is not limiting. The front surface 213Sa may be inclined over the entire radial range so as to shift forward as it moves radially outward. Alternatively, the region of the front surface 213Sa near the outer peripheral surface 213So may extend in a plane perpendicular to the axial direction.

[0033] When the kneading pieces 213 of this embodiment are viewed in the axial direction, a part (the radially outer part) of the protruding parts 213P is located outside the screw shaft 211, and another part (the radially inner part) overlaps with the screw shaft 211. By providing the protruding parts 213P on the outside of the screw shaft 211 as viewed in the axial direction, it is possible to effectively knead the wood raw material located outside the screw shaft 211 in the radial direction. Furthermore, by overlapping the protruding parts 213P with the screw shaft 211 as viewed in the axial direction, it is possible to effectively knead the wood raw material sent to the inside of the screw shaft 211 in the radial direction.

[0034] 5, the portion near the front end of the screw 21 is detachable from the other portions. Specifically, the tip portion 21a, which includes a portion near the front end of the screw shaft 211, a portion near the front end of the screw blade 212, and the kneading pieces 213, is detachable from the main body portion 21m, which includes the remaining portions of the screw shaft 211 and the remaining portions of the screw blade 212. The tip portion 21a and the main body portion 21m may be made of different materials.

[0035] The tip portion 21a is attached to and detached from the main body portion 21m by engaging a spline shaft SS extending axially forward from the front end face of the screw shaft 211 of the main body portion 21m with a recess (not shown) provided in the rear end face of the tip portion 21a, which extends axially in the radial center and has spline grooves formed on its circumferential surface.

[0036] The outer diameter of the screw 21 including the screw blade 212 (i.e., the outer diameter at the position of the outer circumferential surface 212So. Hereinafter, the screw diameter D 21 The internal volume of the cylinder 10 (internal space SP 10 (volume)V 10 and the volume V of the screw shaft 211 211 The ratio of V is an example. 10 :V 211 = 3:1 to 6:1. In this embodiment, the outer diameter of the screw shaft 211 is constant over the entire area from the rear end to the front end (tip). 21 is constant throughout the entire area from the rear end to the front end (tip).

[0037] The drive unit 22 is a mechanism for applying a rotational force to the screw 21. As shown in Fig. 2, the drive unit 22 includes a motor 221 and a power transmission mechanism 222. The power transmission mechanism (including, for example, a chain, a sprocket, etc.) is connected to the rotating shaft of the motor and the rear end surface 211Sb of the screw shaft 211 (Fig. 3), and transmits the rotational force of the motor to the screw 21.

[0038] [Movement restriction mechanism 30] The movement limiting mechanism 30 is arranged in the internal space SP of the cylinder 10. 10 The movement limiting mechanism 30 is a mechanism that limits (suppresses) the forward axial movement of the wood raw material processed by the cylinder 10. The movement limiting mechanism 30 is provided on the front side of the cylinder 10.

[0039] As shown in FIG. 1, the movement limiting mechanism 30 mainly includes a brake part 31, an actuator part 32, and a link part 33.

[0040] The braking portion 31 includes a first braking piece 311, a second braking piece 312, and a third braking piece 313. The first braking piece 311, the second braking piece 312, and the third braking piece 313 have the same shape.

[0041] As shown in FIG. 6(a), each of the first braking piece 311, the second braking piece 312, and the third braking piece 313 includes a base B and a braking surface CS provided on the base B.

[0042] The base B has a trapezoidal block shape in a plan view, and has a front surface BSa, a rear surface BSb, an upper surface BSc, and a lower surface BSd.

[0043] The braking surface CS is a concave curved surface on the upper surface BSc of the base B, extending in the longitudinal direction of the base B (i.e., the direction in which the front surface BSa and the rear surface BSb face each other). As shown in FIG. 6(b), the width (circumferential width) of the braking surface CS decreases from the rear surface BSb to the front surface BSa (i.e., from the rear to the front in the axial direction). Also, as shown in FIGS. 6(c) and 6(d), the maximum depth of the braking surface CS (i.e., the maximum amount of recession from the upper surface BSc) decreases from the rear surface BSb to the front surface BSa. In the following description, the straight line connecting the positions where the amount of recession of the braking surface CS is maximum at each axial position is referred to as the base line BL. As shown in FIGS. 6(a) and 6(b), the base line BL extends axially through the center of the width direction (circumferential direction) of the base B.

[0044] The radius of curvature of the braking surface CS as viewed in the axial direction is constant over the entire area in the longitudinal direction of the base B. In this embodiment, the radius of curvature of the braking surface CS is equal to the inner diameter d of the cylinder 10. 10That is, the radius of curvature of the braking surface CS is equal to the radius of curvature of the inner circumferential surface 10Si of the cylinder 10.

[0045] With the upper surface BSc facing radially inward, the first braking piece 311, the second braking piece 312, and the third braking piece 313 each have an area near their rear surface BSb pivotally connected to an area near the front end 10a of the cylinder 10. In this embodiment, the first braking piece 311, the second braking piece 312, and the third braking piece 313 are each pivotally connected to the cylinder 10 by having a pivot shaft (not shown) pass through a protrusion (not shown) provided on the lower surface BSd and a protrusion (not shown) provided on the outer circumferential surface 10So near the front end 10a of the cylinder 10. The pivot shaft extends in a direction perpendicular to the radial direction in a plane perpendicular to the axial direction.

[0046] As shown in Figures 7(a) and 7(b), the first braking piece 311 is located above the cylinder 10 when the wood fuel production device 100 is installed on the floor. The second braking piece 312 is located 120° rotated clockwise from the first braking piece 311 when viewed from the front. The third braking piece 313 is located 120° rotated clockwise from the second braking piece 312 when viewed from the front. The braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 are spaced apart from each other in the circumferential direction. The braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 are arranged at equal intervals in the circumferential direction.

[0047] The actuator unit 32 (FIG. 1) includes a first actuator 321, a second actuator 322, and a third actuator 323. Each of the first actuator 321, the second actuator 322, and the third actuator 323 is a hydraulic actuator including a cylinder (not shown) and a rod (not shown).

[0048] The first actuator 321 is provided on the outer peripheral surface 10So of the cylinder 10, rearward of the first braking piece 311. The second actuator 322 is provided on the outer peripheral surface 10So of the cylinder 10, rearward of the second braking piece 312. The third actuator 323 is provided on the outer peripheral surface 10So of the cylinder 10, rearward of the third braking piece 313. The extending directions of the rods of the first actuator 321, second actuator 322, and third actuator 323 coincide with the axial direction.

[0049] The link portion 33 (FIG. 1) includes a first link 331, a second link 332, and a third link 333.

[0050] The first link 331 includes a front arm 331a and a rear arm 331b. The front end of the front arm 331a is pivotally connected to the lower surface BSd of the base B of the first braking piece 311. The rear end of the front arm 331a is pivotally connected to the front end of the rear arm 331b. The rear end of the rear arm 331b is connected to the rod of the first actuator 321.

[0051] The second link 332 includes a front arm 332a and a rear arm 332b. The front end of the front arm 332a is pivotally connected to the lower surface BSd of the base B of the second braking piece 312. The rear end of the front arm 332a is pivotally connected to the front end of the rear arm 332b. The rear end of the rear arm 332b is connected to the rod of the second actuator 322.

[0052] The third link 333 includes a front arm 333a and a rear arm 333b. The front end of the front arm 333a is pivotally connected to the lower surface BSd of the base B of the third braking piece 313. The rear end of the front arm 333a is pivotally connected to the front end of the rear arm 333b. The rear end of the rear arm 333b is connected to the rod of the third actuator 323.

[0053] By moving the rods of the first actuator 321, the second actuator 322, and the third actuator 323 in the axial direction, the first braking piece 311, the second braking piece 312, and the third braking piece 313 pivot via the first link 331, the second link 332, and the third link 333. When the rods of the first actuator 321, the second actuator 322, and the third actuator 323 are moved axially rearward, the front faces BSa of the first braking piece 311, the second braking piece 312, and the third braking piece 313 move radially outward. When the rods of the first actuator 321, the second actuator 322, and the third actuator 323 are moved axially forward, the front faces BSa of the first braking piece 311, the second braking piece 312, and the third braking piece 313 move radially inward.

[0054] 7(a) shows the braking portion 31 in a reference state. When the braking portion 31 is in the reference state, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 are each continuous with the inner circumferential surface 10Si of the cylinder 10. In other words, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 each extend within an imaginary curved surface that is a direct forward extension of the inner circumferential surface 10Si of the cylinder 10.

[0055] When the braking section 31 is in the reference state, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 come into contact with the wood raw material (wood block MA, described in detail later) discharged from the cylinder 10 without pressing the wood raw material radially inward. At this time, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 restrict the forward movement of the wood raw material by sliding friction.

[0056] 7(b) shows the braking portion 31 as an example of a throttled state. When the braking portion 31 is in the throttled state, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 are each continuous with the inner circumferential surface 10Si of the cylinder 10 at their rear ends and shift radially inward as they move forward. In other words, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 are each located radially inward of an imaginary curved surface formed by extending the inner circumferential surface 10Si of the cylinder 10 directly forward.

[0057] When the braking portion 31 is in the throttled state, the braking surfaces CS of the first braking piece 311, the second braking piece 312, and the third braking piece 313 come into contact with the wood raw material discharged from the cylinder 10 while pressing the wood raw material radially inward. Therefore, the force with which the braking portion 31 restricts the axial forward movement of the wood raw material is greater when the braking portion 31 is in the throttled state than when the braking portion 31 is in the standard state.

[0058] The pivotable range of the first to third braking pieces 311 to 313 (the radial movable range of the braking surface CS) can be set as appropriate. In this embodiment, each of the first to third braking pieces 311 to 313 can move to an open position where the braking surface CS of each piece is located radially outward of an imaginary curved surface formed by extending the inner circumferential surface 10Si of the cylinder 10 directly forward. When the first to third braking pieces 311 to 313 are in the open position, the braking portion 31 is in an open state. In the open state, the braking portion 31 does not come into contact with the wood raw material and does not restrict the axial forward movement of the wood raw material.

[0059] [Hopper 40] The hopper 40 has a rectangular cylindrical shape in a plan view, with the short sides becoming shorter from top to bottom. The upper opening 40Ac of the hopper 40 opens upward. The lower opening 40Ad of the hopper 40 opens downward. The lower opening 40Ad is connected to the opening 10A of the cylinder 10.

[0060] [Control unit 50] The control unit 50 controls the operation of the wood fuel production device 100 .

[0061] 2, the control unit 50 is electrically connected to the motor 221 of the screw mechanism 20. The control unit 50 is also electrically connected to the first actuator 321, the second actuator 322, and the third actuator 323 of the actuator unit 32 of the movement limiting mechanism 30.

[0062] In this embodiment, the control unit 50 acquires the current value of the motor 221 from the motor 221 and controls the hydraulic pressure of the first actuator 321, the second actuator 322, and the third actuator 323 based on the acquired current value. The current value of the motor 221 increases as the load torque on the motor 221 and, ultimately, the screw 21 increases. Therefore, when the acquired current value of the motor 221 increases, the control unit 50 reduces the hydraulic pressure of the first actuator 321, the second actuator 322, and the third actuator 323, thereby reducing the braking force of the braking unit 31. Conversely, when the acquired current value of the motor 221 decreases, the control unit 50 increases the hydraulic pressure of the first actuator 321, the second actuator 322, and the third actuator 323, thereby increasing the braking force of the braking unit 31 (described in detail below).

[0063] [Wood fuel production method using wood fuel production device 100] A method for producing wood fuel using the wood fuel production device 100 will now be described.

[0064] As shown in the flowchart of FIG. 8, the wood fuel production method executed by the wood fuel production device 100 includes a crushing process S1, a compression process S2, a kneading process S3, and a cutting process S4.

[0065] [Wood raw materials] The wood raw material used to produce wood fuel may be any wood, and the type is not limited. The wood raw material may be in the form of chips with a diameter of less than 7 mm, but is not limited to this. The moisture content of the wood raw material may be approximately 0 to 30%, but is not limited to this. In the following explanation, wood chips CP are used as the wood raw material. Wood chips CP are, for example, pruned branches (specific gravity approximately 0.3) dried to a moisture content of approximately 30% and cut into chips with a diameter of 5 mm or less.

[0066] [Crushing process S1] The crushing process S1 is performed in the internal space SP of the cylinder 10. 10 Screw area 10 A1 (i.e., the internal space SP 10 In the crushing process S1, the wood raw material located radially outward of the outer peripheral surface 212So of the screw blade 212 is crushed by the outer peripheral surface 212So of the screw blade 212 and the inner peripheral surface 10Si of the cylinder 10.

[0067] In the crushing process S1, first, the motor 221 is driven to rotate the screw 21, and a large number of wood chips CP are fed from the opening 10A of the cylinder 10 through the hopper 40 into the internal space SP. 10 The rotation direction of the screw 21 is clockwise when viewed from the front to the rear in the axial direction.

[0068] Internal space SP 10 The wood chips CP fed into the inner space SP are transported by the rotation of the screw 21. 10 Now, as mentioned above, the screw region 10 A1 The surface roughness of the inner peripheral surface 10Si of the cylinder 10 and the surface roughness of the outer peripheral surface 212So of the screw blade 212 are larger than the surface roughness of the outer peripheral surface 211So of the screw shaft 211, the front surface 212Sa of the screw blade 212, and the rear surface 212Sb of the screw blade 212. Therefore, the wood piece CP located radially outward from the outer peripheral surface 212So of the screw blade 212 (hereinafter referred to as the outer wood piece CP OUT9(a) is ground and pulverized by the inner circumferential surface 10Si of the cylinder 10 and the outer circumferential surface 212So of the screw blade 212, and becomes powder. On the other hand, the wood chips CP located radially inside the outer circumferential surface 212So of the screw blade 212 (hereinafter referred to as inner wood chips CP IN 9(a) is not ground by the inner peripheral surface 10Si of the cylinder 10 and the outer peripheral surface 212So of the screw blade 212. In FIG. 9(a), the outer peripheral line L 212So is shown by a dashed line.

[0069] In this way, in the crushing process S1, the inner wood chip CP IN Without crushing the outer wood chips CP OUT Therefore, the screw region 10 is crushed by the crushing process S1. A1 The inner wood chips CP, which have the same size (diameter) as when they were supplied to the cylinder 10, are placed on the inner side in the radial direction. IN There is an inner piece of wood CP on the radial outside. IN Powdered outer wood chips CP that are smaller in size (diameter) than OUT A state where exists is formed (Figure 9(a)).

[0070] [Compression process S2] The compression process S2 is performed in the internal space SP of the cylinder 10. 10 Screw area 10 A1 The compression process S2 is carried out in parallel with at least a part of the pulverization process S1. In the compression process S2, the internal space SP 10 The wood chips CP fed to the machine are compressed by the screw 21.

[0071] The compression process S2 is performed by rotating the screw 21 to compress the internal space SP 10 Inner piece of wood CP moving forward IN As described above, the pitch of the screw blade 212 gradually decreases in three stages from the rear side to the front side in the axial direction. IN The inner wood piece CP is compressed in the axial direction as the pitch of the screw blade 212 decreases.IN By compressing the cylinder 10, the internal space SP 10 Then the following occurs:

[0072] First, the inner piece of wood (CP) is compressed. IN The heat generated causes the temperature of the cylinder 10 to rise, and in this embodiment, the temperature reaches, for example, about 40°C to 80°C. OUT The outer wood chips CP are crushed into small powder by the crushing process S1. OUT The outermost part in the radial direction is burned and solidified by the heat of the cylinder 10 and the frictional heat between the inner circumferential surface 10Si of the cylinder 10. The solidified layer HL (FIG. 9(b)) formed in this way is a layer of wood that is hardened by the heat of the cylinder 10 and the inner circumferential surface 10Si of the inner wood piece CP. IN It has the function of trapping the heat generated by the compression of the cylinder radially inward.

[0073] In this way, in the compression process S2, the inner wood piece CP IN The heat generated by the compression of the outer wood chips CP OUT The outermost part of the screw region 10 is baked to form a solidified layer HL. A1 In the region near the front end of the screw 21, chip-shaped inner wood pieces CP having the same size (diameter) as when supplied to the cylinder 10 are placed radially inside. IN There is an inner piece of wood CP on the radial outside. IN Powdered outer wood chips CP that are smaller in size (diameter) than OUT There is an outer piece of wood called CP OUT A solidified layer HL is formed on the outermost surface of the substrate (FIG. 9(b)).

[0074] [Kneading process S3] The kneading process S3 is performed in the internal space SP of the cylinder 10. 10 The non-screw region 10 in front of the front end surface 211Sa of the screw shaft 211 A2 In the kneading process S3, the movement limiting mechanism 30 limits the forward movement of the wood raw material while the screw 21 kneads the wood raw material.

[0075] In the kneading process S3, the screw region 10 A1 From non-screw area 10 A2 The inner wood piece sent to CP IN The wood raw material is kneaded by the front end surface 211Sa of the screw shaft 211 and the kneading pieces 213. In this specification and the present invention, "kneading of wood raw materials" means mixing the wood raw materials with a certain member, thereby raising the temperature of the wood raw materials due to friction between the member and the wood raw materials and / or compressing the wood raw materials with the member, and extracting binding components (components that bind wood raw materials together; examples include lignin, sugars, etc.) from the wood raw materials.

[0076] Specifically, screw region 10 A1 From non-screw area 10 A2 The inner wood piece sent to CP IN The inner wood piece CP IN The temperature rises due to friction with the front surface 213Sa of the kneading piece 213. IN is sandwiched and compressed between the front surface 213Sa of the kneading piece 213 and the surrounding wood pieces CP. IN The temperature rise occurs in the inner piece of wood CP due to friction with the front end surface 211Sa of the screw shaft 211. IN is the surrounding inner wood piece CP in compression process S2. IN The kneading process is carried out by kneading the bonded inner wood pieces CP IN The inner wood pieces CP that are joined together in the compression process S2 are broken down again. IN The lump is doughnut-shaped (annular or cylindrical) with a hollow center in the radial direction due to the presence of the screw shaft 211. During kneading, the kneading pieces 213 knead the inner wood piece CP IN In this embodiment, the inner wood piece CP IN The radially inward feeding of the particles is improved.

[0077] By kneading, the inner wood chip CP IN This removes the binding component from the non-screw region 10. A2 The wood pieces CP present in the kneading zone are bonded together to form a cylindrical wood block MA (Fig. 9(c)). At this time, the solidified layer HL present at the outermost radial position functions to trap heat. This suppresses the release of heat generated by the kneading from the wood block MA, and promotes a rise in the temperature of the wood block MA. This allows further bonding components to be extracted.

[0078] The above kneading is carried out in the non-screw region 10 A2 The forward movement of the wooden block MA is restricted by the braking surfaces CS of the first braking piece 311 to the third braking piece 313 arranged in front of the non-screw area 10 (FIG. 9(d)). A2 As shown in FIG. 10 , a backward force F acts on the wood pieces CP and wood blocks MA present in the cylinder 10. By limiting the forward movement of the wood blocks MA formed by kneading, and in turn the wood pieces CP during kneading, kneading is performed in this manner, which allows for good friction between the kneaded pieces 213 and the front end faces 211Sa and the wood pieces CP, and good compression of the wood pieces CP by the kneaded pieces 213. The temperature of the wood blocks MA drops as they move forward while being restricted by the brakes 31 outside the cylinder 10. This solidifies the bonding components, further improving the strength (hardness) of the wood blocks MA. Alternatively, the wood blocks MA may be compressed radially inward as they move forward while being restricted by the brakes 31 outside the cylinder 10. This reduces the diameter of the wood blocks MA, increasing their density and further improving their strength.

[0079] In this embodiment, while the kneading process S3 is being performed, the control unit 50 controls the hydraulic pressure of the first actuator 321, the second actuator 322, and the third actuator 323 based on the current value (load) of the motor 221. Specifically, when the current value of the motor becomes larger than a first threshold, the control unit 50 controls the actuator unit 32 to move the first braking piece 311 to the third braking piece 313 radially outward. This reduces the braking force of the braking unit 31. When the current value of the motor becomes smaller than a second threshold that is smaller than the first threshold, the control unit 50 controls the actuator unit 32 to move the first braking piece 311 to the third braking piece 313 radially inward. This increases the braking force of the braking unit 31.

[0080] In this way, by adjusting the braking force of the braking unit 31 according to the current value of the motor 221 (i.e., the load torque of the motor 221 and therefore the screw 21), the non-screw region 10 A2 Therefore, the magnitude of the backward force F applied to the substrate can be kept constant (or within a desired range), and the kneading process S3 can be carried out continuously and stably.

[0081] [Cutting process S4] In the cutting process S4, the wood block MA sent forward from the braking unit 31 is cut in a direction perpendicular to the axial direction by a cutter or other cutting device (not shown). This results in cylindrical wood fuel. The specific gravity of the produced wood fuel is, for example, approximately 1.1 to 1.3.

[0082] [Effects of the embodiment] The advantageous effects of the wood fuel production device 100 and wood fuel production method of this embodiment are summarized below.

[0083] In the wood fuel production device 100 and wood fuel production method of this embodiment, the wood raw material (wood chips CP) is fed to the non-screw region 10 in front of the screw 21. A2In this process, the wood is kneaded by the front end surface 211Sa of the screw shaft 211 and the kneading pieces 213. This allows efficient extraction of binding components from the wood raw material, enabling production of a block of wood MA with sufficient strength, and ultimately wood fuel, at low cost. For example, the amount of power consumed to produce wood fuel is smaller than in the production device (production process) of Patent Document 1, which requires heating the wood raw material using a heater, or the production device (production process) of Patent Document 2, which requires driving a motor at a high load (current value) to pelletize the wood raw material. This reduces production costs accordingly.

[0084] In the wood fuel production device 100 and wood fuel production method of this embodiment, the wood raw material (wood chips CP) is kneaded while the forward movement of the wood raw material is restricted by the movement restriction mechanism 30. This allows for better kneading.

[0085] In the wood fuel production device 100 and wood fuel production method of this embodiment, the non-screw region 10 A2 The surface roughness of the inner circumferential surface 10Si of the cylinder 10 in the screw region 10 A1 The surface roughness of the inner peripheral surface 10Si of the cylinder 10 in the non-screw region 10 is smaller than that of the inner peripheral surface 10Si of the cylinder 10 in the kneading process S3. Therefore, even if the wood pieces CP (or wood blocks MA) expand due to heat generation in the kneading process S3, the forward movement of the wood pieces CP (or wood blocks MA) is unlikely to be excessively inhibited by friction between the inner peripheral surface 10Si of the cylinder 10 and the wood pieces CP (or wood blocks MA). A2 The inner circumferential surface 10Si of the cylinder 10 in the kneading region does not have any convex portion that protrudes radially inward.

[0086] In the wood fuel production device 100 and wood fuel production method of this embodiment, the surface roughness of the front end face 211Sa of the screw shaft 211 is greater than the surface roughness of the outer circumferential surface 211So of the screw shaft 211. Therefore, the wood chips CP can be well mixed by the friction between the front end face 211Sa and the wood chips CP.

[0087] In the wood fuel production device 100 and wood fuel production method of this embodiment, the wood chips CP are kneaded by the kneading pieces 213 that protrude forward from the front end surface 211Sa of the screw shaft 211. This allows the wood chips CP to be kneaded more effectively.

[0088] In the wood fuel production apparatus 100 and wood fuel production method of this embodiment, the wood chips CP are kneaded while being fed radially inward by the kneading pieces 213, so the substantially doughnut-shaped mass formed in the compression process S2 is effectively transformed into a cylindrical mass by the kneading process S3. Therefore, cylindrical wood fuel can be produced even if the diameter of the screw shaft 211 is increased. Increasing the diameter of the screw shaft 211 is desirable because it increases the strength of the screw shaft 211. Increasing the strength of the screw shaft 211 makes it possible to feed stronger (harder) wood blocks MA forward to produce stronger wood fuel. Damage to the screw 21 can also be effectively prevented.

[0089] In the wood fuel production device 100 and wood fuel production method of this embodiment, the screw region 10 of the inner circumferential surface 10Si of the cylinder 10 A1 The surface roughness of the outer peripheral surface 212So of the screw shaft 211 and the surface roughness of the front surface 212Sa of the screw blade 212 and the surface roughness of the rear surface 212Sb of the screw blade 212 are greater than the surface roughness of the outer peripheral surface 211So of the screw shaft 211, the surface roughness of the front surface 212Sa of the screw blade 212, and the surface roughness of the rear surface 212Sb of the screw blade 212. Therefore, the internal space SP of the cylinder 10 10 In the radial direction, a large piece of wood CP is located inside. IN There is a small outer piece of wood CP on the radial outside. OUT This means that the small outer wood piece CP OUT The formation of the solidified layer HL can be promoted by burning the inner wood piece CP surrounded by the solidified layer HL. IN The screw region 10 of the inner circumferential surface 10Si of the cylinder 10 is advantageous in two respects: the screw region 10 of the inner circumferential surface 10Si of the cylinder 10 is kneaded efficiently. A1The same effect can be achieved even if only one of the surface roughness at the outer surface 212So of the screw shaft 211 and the surface roughness of the outer surface 212So of the screw blade 212 is greater than the surface roughness of the outer surface 211So of the screw shaft 211, the surface roughness of the front surface 212Sa of the screw blade 212, and the surface roughness of the rear surface 212Sb of the screw blade 212.

[0090] In the wood fuel production device 100 and wood fuel production method of this embodiment, the kneading pieces 213 protrude more forward as they move downstream in the rotation direction of the screw 21. This allows the inclined front surfaces 213Sa to be effectively pressed against the wood pieces CP, effectively applying frictional and pressing forces to the wood pieces CP.

[0091] In the wood fuel production device 100 and wood fuel production method of this embodiment, the surface roughness of the front surface 213Sa of the kneading piece 213 is greater than the surface roughness of the outer circumferential surface 211Sa of the screw shaft 211. Therefore, the frictional force between the front surface 213Sa and the wood piece CP is large, allowing for good kneading by the kneading piece 213.

[0092] In the wood fuel production device 100 and wood fuel production method of this embodiment, the tip 21a of the screw 21 (i.e., the portion including the kneading pieces 213 and the front end face 211Sa of the screw shaft 211) is detachable from the main body 21m. Therefore, if the kneading pieces 213 and the front end face 211Sa become worn during the kneading process, only the tip 21a can be replaced. This is advantageous in terms of cost and labor time compared to an embodiment that requires the entire screw 21 to be replaced.

[0093] In the wood fuel production device 100 and wood fuel production method of this embodiment, the braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 of the braking unit 31 are spaced apart from one another in the circumferential direction. Therefore, the braking force is less likely to become excessively large compared to when braking surfaces CS are present across the entire circumferential area. Furthermore, because the braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 of the braking unit 31 are equally spaced apart in the circumferential direction, a balanced braking force can be applied to the cylindrical wood block MA.

[0094] In the wood fuel production device 100 and wood fuel production method of this embodiment, the circumferential width of the braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 of the braking section 31 decreases toward the front. This prevents the braking force from becoming excessively large.

[0095] In the wood fuel production apparatus 100 and wood fuel production method of this embodiment, the braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 of the braking unit 31 can move radially. Furthermore, the control unit 50 controls the radial positions of the braking surfaces CS of the first braking piece 311, second braking piece 312, and third braking piece 313 according to the current value (load) of the motor 221. This makes it possible to apply a braking force according to the strength (hardness) of the wood block MA formed by the kneading process S3, thereby maintaining the force F (FIG. 10) at a constant value (or within a certain range) and continuously performing the kneading process S3 satisfactorily.

[0096] <Modification> The wood fuel production device 100 and wood fuel production method of this embodiment may also employ the following modifications.

[0097] [Modification of cylinder 10] In the above embodiment, the surface roughness of the inner circumferential surface 10Si of the cylinder 10 is A2 In screw region 10 A1 However, the surface roughness of the inner peripheral surface 10Si of the cylinder 10 is smaller than that of the non-screw region 10A2 and screw area 10 A1 In this case, for example, the surface roughness of the inner circumferential surface 10Si of the cylinder 10 may be the same as that of the screw region 10 in the above embodiment over the entire area. A1 The surface roughness may be the same as that of the non-screw region 10 of the above embodiment over the entire area. A2 The surface roughness may be about the same as that in the case of

[0098] In the above embodiment, the cylinder 10 is an integral cylindrical member, but is not limited to this. For example, the screw region 10 of the cylinder 10 A1 and non-screw area 10 A2 It may be separate from the.

[0099] [Modification of screw 21] In the above embodiment, the surface roughness of the front end face 211Sa of the screw shaft 211 is greater than the surface roughness of the outer circumferential surface 211So of the screw shaft 211. However, this is not limited to this. The surface roughness of the front end face 211Sa and the surface roughness of the outer circumferential surface 211So may be the same. In this case, for example, the surface roughness of the front end face 211Sa may be approximately the same as the surface roughness of the outer circumferential surface 211So in the above embodiment, or the surface roughness of the outer circumferential surface 211So may be approximately the same as the surface roughness of the front end face 211Sa in the above embodiment.

[0100] In the above embodiment, the front end surface 211Sa of the screw shaft 211 is a flat surface extending in a plane perpendicular to the axial direction, but is not limited to this. The front end surface 211Sa may have any shape, such as a convex shape that protrudes forward or a concave shape that recesses backward. Alternatively, the front end surface 211Sa may be a flat surface inclined with respect to a plane perpendicular to the axial direction.

[0101] In the above embodiment, the pitch of the screw flight 211 decreases in three stages as it moves forward, but this is not limited to this. The pitch of the screw flight 211 may be any mode in which it decreases as it moves forward, such as a mode in which it gradually decreases without any steps, a mode in which it decreases in two stages, or a mode in which it decreases in more than three stages. Any of these modes is an example of a mode in which "the pitch of the screw decreases as it moves forward." Alternatively, the pitch of the screw flight 211 may be constant over the entire axial direction.

[0102] In the above embodiment, the surface roughness of the outer peripheral surface 212So of the screw flight 212 is greater than the surface roughness of the front surface 212Sa and the rear surface 212Sb of the screw flight 212, but this is not limited to this. The surface roughness of the outer peripheral surface 212So and the surface roughness of the front surface 212Sa and the rear surface 212Sb may be the same. In this case, for example, the surface roughness of the outer peripheral surface 212So may be approximately the same as the surface roughness of the front surface 212Sa and the rear surface 212Sb in the above embodiment, or the surface roughness of the front surface 212Sa and the rear surface 212Sb may be approximately the same as the surface roughness of the outer peripheral surface 212So in the above embodiment.

[0103] In the above embodiment, the shape of the kneading pieces 213 may be any shape that protrudes entirely or partially forward from the front end surface 211Sa of the screw shaft 211. Specifically, for example, as shown in FIG. 11(a), kneading pieces 215 that are rectangular in plan view and extend linearly from the front end of the screw blade 212 may be used. Alternatively, as shown in FIG. 11(b), kneading pieces 217 that are kneading pieces 215 extended radially inward may be used. The inclination angle of the front surfaces 213Sa, 215Sa, and 217Sa of the kneading pieces 213, 215, and 217 relative to a plane perpendicular to the axial direction is arbitrary. The front surfaces 213Sa, 215Sa, and 217Sa may extend in a plane perpendicular to the circumferential direction. The front surfaces 215Sa and 217Sa of the kneading pieces 215 and 217 may also be inclined so as to shift forward as they move radially outward.

[0104] The portion of the kneading piece such as the kneading piece 213 that is located forward of the front end surface 211Sa of the screw shaft 211 may be provided only in the area that overlaps with the screw shaft 211 when viewed in the axial direction, or may be provided only in the area outside the screw shaft 211 when viewed in the axial direction.

[0105] In the above embodiment, the surface roughness of the front surface 213Sa of the kneading piece 213 is larger than the surface roughness of the outer circumferential surface 211Sa of the screw shaft 211, but this is not limited thereto. The surface roughness of the front surface 213Sa may be approximately the same as the surface roughness of the outer circumferential surface 211Sa in the above embodiment.

[0106] In the above embodiment, the kneading pieces 213 may be omitted. In this case, the kneading is performed by the front end surface 211Sa of the screw shaft 211.

[0107] In the above embodiment, the tip portion 21a of the screw 21 does not have to be configured to be detachable from the main body portion 21m.

[0108] [Modification of the movement limiting mechanism 30] In the above embodiment, the movement limiting mechanism 30 may be any form having at least three braking surfaces, each of which presses the wood raw material discharged from the cylinder 10 radially inward. Specifically, for example, the circumferential width of the braking surfaces CS of the first braking piece 311 to the third braking piece 313 may be constant over the entire axial area. The braking surfaces CS of the first braking piece 311 to the third braking piece 313 may not be arranged at equal intervals in the circumferential direction. The braking surfaces CS of the first braking piece 311 to the third braking piece 313 may be in contact with each other in the circumferential direction without any gaps.

[0109] The braking portion 31 may further include braking pieces similar to the first braking piece 311 to the third braking piece 313. In this case, the number of braking pieces and braking surfaces will be four or more.

[0110] The movement limiting mechanism 30 may be configured to move the braking surfaces CS of the first to third braking pieces 311 to 313 between a first position where a first region of the braking surface CS contacts the wood raw material and a second position where a second region of the braking surface CS, which is smaller in area than the first region, contacts the wood raw material. Specifically, as shown in Figures 12(a) and 12(b), the first to third braking pieces 311 to 313, each having a braking surface CS curved along the axial direction, are pivoted about a pivot axis AX extending in a direction perpendicular to the radial direction within a plane perpendicular to the axial direction. This causes the braking surface CS to move between a first position (Figure 12(a)) where the first region of the braking surface CS contacts the wood raw material (wood block MA) and a second position (Figure 12(b)) where the second region of the braking surface CS contacts the wood raw material (wood block MA). If the circumferential width of the braking surface CS varies along the axial direction, the second region may be the region of the braking surface CS that has the largest circumferential width. Furthermore, when the braking surface CS of each of the first braking piece 311 to third braking piece 313 is in the second position, the second region of the braking surface CS of each of the first braking piece 311 to third braking piece 313 may be continuous in the circumferential direction and form a continuous surface that extends around the entire circumference (360°) in the circumferential direction.

[0111] Although the movement limiting mechanism 30 in the above embodiment pivots the first braking piece 311 to the third braking piece 313 of the braking portion 31, the movement limiting mechanism 30 is not limited to this. The movement limiting mechanism 30 may be configured to move the first braking piece 311 to the third braking piece 313 of the braking portion 31 linearly in the radial direction.

[0112] The movement limiting mechanism 30 of the above embodiment may have only the braking unit 31. In this case, the braking unit 31 may be biased radially inward by, for example, an elastic member. In this case, a pressing force (braking force) corresponding to the elastic force of the elastic member and the strength of the wood block MA is applied to the wood block MA. Alternatively, the first braking piece 311 to the third braking piece 313 of the braking unit 31 may be fixedly provided at a position where the braking surface CS is shifted radially inward from the reference position (FIG. 7(a)). In this case, a pressing force (braking force) corresponding to the strength of the wood block MA is applied to the wood block MA.

[0113] In the movement limiting mechanism 30 of the above embodiment, the actuator unit 32 and the link unit 33 may be in any form that can cause the movement of the first braking piece 311 to the third braking piece 313. The actuator unit 32 may be equipped with a pneumatic actuator instead of a hydraulic actuator.

[0114] The wood fuel production device 100 of the above embodiment does not necessarily have to include the movement restriction mechanism 30.

[0115] [Modification of the control unit 50] In the above embodiment, the control unit 50 controls the actuator unit 32 of the movement control mechanism 30 based on the load of the motor 221, but this is not limited to this. The temperature and / or humidity inside the cylinder 10 can also affect the strength of the wood block MA formed in the kneading process S3. Therefore, for example, a temperature sensor and / or humidity sensor may be provided on the inner circumferential surface 10Si of the cylinder 10. In this case, the control unit 50 may control the actuator unit 32 based on at least one of the load of the motor 221, the temperature inside the cylinder 10, and the humidity inside the cylinder 10.

[0116] The control unit 50 does not need to perform automatic control. In this case, the user of the wood fuel production apparatus 100 instructs the control unit 50 to drive the motor 221, for example, via an input unit (not shown). The control unit 50 drives the motor 221 based on this instruction. As a result, the rotation of the motor 221 is transmitted to the screw 21 via the power transmission mechanism 222, causing the screw 21 to rotate. The user of the wood fuel production apparatus 100 instructs the control unit 50, for example, via an input unit (not shown), on the state of the brake unit 31. Based on this instruction, the control unit 50 controls the hydraulic pressure of the first actuator 321, second actuator 322, and third actuator 323. As a result, the first brake piece 311, second brake piece 312, and third brake piece 313 pivot via the first link mechanism 331, second link mechanism 332, and third link mechanism 333, bringing the brake unit 31 into the reference state or any throttle state.

[0117] [Modification of manufacturing method] In the wood fuel production method of the above embodiment, the crushing process S1 and / or the compression process S2 may be omitted. Even if these processes are not performed, the solidified layer HL can be formed and the wood block MA can be formed by the kneading process S3. The kneading process S3 may also be performed without restricting the movement of the wood material with the movement restriction mechanism 30.

[0118] [Initial processing] The above explanations are for each process in the steady-state wood fuel production apparatus 100. In other words, they describe the process at a certain point in time when wood fuel production is being carried out continuously.

[0119] In contrast, when the wood fuel manufacturing device 100 starts operating, there are no wood pieces CP or wood blocks MA in front, so for example, the force F is not large enough, and the effects of the kneading process S3, etc. are smaller than in the steady state.

[0120] Therefore, when the wood fuel production device 100 starts operating, the control unit 50 positions the first braking piece 311 to the third braking piece 313 of the braking unit 31 at the innermost position within the radial movable range. A2 Even if the wood block MA discharged from the non-screw area 10 does not have sufficient strength, A2 Therefore, the force F applied to the mixture can be increased, and the kneading process S3 can be performed satisfactorily.

[0121] Thereafter, the control unit 50 moves the first to third braking pieces 311 to 313 of the braking unit 31 radially outward based on the fact that the current value (i.e., load) of the motor 221 has exceeded a predetermined value. Next, the control unit 50 repeats the following steps: (1) increasing the current value of the motor 221 due to an increase in the strength of the wood block MA, (2) decreasing the current value of the motor 221 by moving the first to third braking pieces 311 to 313 radially outward, (3) increasing the current value of the motor 221 again due to a further increase in the strength of the wood block MA, and (4) decreasing the current value of the motor 221 again by moving the first to third braking pieces 311 to 313 further radially outward, thereby achieving a steady state in which the wood block MA has the desired strength and the first to third braking pieces 311 to 313 are positioned at the desired positions.

[0122] [Other variations] The wood fuel production apparatus of the above embodiment does not have a heating mechanism for heating the wood raw material. Furthermore, the wood fuel production method of the above embodiment does not involve heating the wood material using a heating mechanism. However, this is not limited to this, and the wood fuel production apparatus of the above embodiment may also include a heating mechanism for heating the wood raw material, and the wood fuel production method of the above embodiment may involve heating the wood fuel using a heating mechanism.

[0123] The wood fuel production device of the above embodiment can produce wood fuel with sufficient strength (hardness) without using a resin binder, etc. However, a resin binder, etc. may be used if necessary.

[0124] As long as the characteristics of the present invention are maintained, the present invention is not limited to the above-described embodiments, and other forms that can be conceived within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0125] 10 cylinders 20 Screw mechanism 21 Screw 211 Screw shaft 212 screw blade 213 Kneaded Pieces 30 Movement restriction mechanism 31 Braking part 32 Actuator section 33 Link section 40 Hopper 50 control section

Claims

1. A cylinder; a screw that sends the wood raw material supplied inside the cylinder forward; a movement limiting section that limits the forward movement of the wood raw material discharged from the front end of the cylinder, The screw A screw shaft; a screw blade provided on the outer peripheral surface of the screw shaft; a kneading piece provided at a front end of the screw shaft and protruding forward from the front end of the screw shaft, The cylinder has a kneading region inside the cylinder and forward of the front end of the screw shaft, for kneading the wood raw material, the movement of which is restricted by the movement restricting portion, with the screw, The movement limiting portion has at least three braking surfaces arranged at a distance from each other in the circumferential direction of the cylinder, each of which presses the wood raw material discharged from the cylinder radially inward of the cylinder, The kneading pieces are positioned in the kneading region of the wood fuel production device and knead the wood raw material.

2. 2. The wood fuel production device according to claim 1, wherein the at least three braking surfaces are arranged at equal intervals in the circumferential direction of the cylinder.

3. 2. The wood fuel production device according to claim 1, wherein the width of each of the at least three braking surfaces in the circumferential direction of the cylinder decreases toward the front.

4. The wood fuel production device according to claim 1 , wherein each of the at least three braking surfaces is movable in the radial direction of the cylinder.

5. A wood fuel production device as described in claim 4, wherein each of the at least three braking surfaces is configured to pivot around a pivot axis extending in a direction perpendicular to the radial direction of the cylinder within a plane perpendicular to the axial direction of the cylinder.

6. each of the at least three braking surfaces is pivotable between a first position in which a first region of each of the at least three braking surfaces contacts the wood raw material and a second position in which a second region of each of the at least three braking surfaces contacts the wood raw material; 6. The wood fuel production device according to claim 5, wherein the area of ​​the second region is smaller than the area of ​​the first region.

7. A wood fuel manufacturing device as described in any one of claims 1 to 6, further comprising a control unit that controls the radial position of the at least three braking surfaces of the cylinder based on at least one of the load of the motor that rotates the screw, the temperature inside the cylinder, and the humidity inside the cylinder.

8. The wood fuel manufacturing device described in claim 7, wherein the control unit moves each of the at least three braking surfaces radially outward when the motor load becomes greater than a first threshold, and moves each of the at least three braking surfaces radially inward when the motor load becomes less than a second threshold that is smaller than the first threshold.

9. The wood fuel production device described in claim 7, wherein the control unit positions each of the at least three braking surfaces at the innermost position within the radial movable range, and moves each of the at least three braking surfaces radially outward when the load on the motor becomes greater than a threshold value.

10. A wood fuel manufacturing device described in any one of claims 1 to 6, which does not have a heating mechanism for applying heat to the wood raw material.

11. A method for controlling a wood fuel production apparatus that produces wood fuel using wood raw materials, comprising: The wood fuel production device includes: A cylinder; a screw that sends the wood raw material supplied inside the cylinder forward; a movement limiting portion that limits the forward movement of the wood raw material discharged from the front end of the cylinder; a control unit; The screw A screw shaft; a screw blade provided on the outer peripheral surface of the screw shaft; a kneading piece provided at a front end of the screw shaft and protruding forward from the front end of the screw shaft, The cylinder has a kneading region inside the cylinder and forward of the front end of the screw shaft, for kneading the wood raw material, the movement of which is restricted by the movement restricting portion, with the screw, The movement limiting portion has at least three braking surfaces arranged at a distance from each other in the circumferential direction of the cylinder, each of which is movable in the radial direction of the cylinder and presses the wood raw material discharged from the cylinder radially inward of the cylinder, The kneading pieces knead the wood raw material located in the kneading area, A control method including changing the radial positions of the at least three braking surfaces of the cylinder based on at least one of the load of a motor that rotates the screw, the temperature inside the cylinder, and the humidity inside the cylinder by the control unit.

12. 12. The control method of claim 11, wherein changing the radial positions of the at least three braking surfaces of the cylinder by the control unit includes moving each of the at least three braking surfaces radially outward based on the load on the motor becoming greater than a first threshold, and moving each of the at least three braking surfaces radially inward based on the load on the motor becoming smaller than a second threshold that is smaller than the first threshold.

13. Changing the positions of the at least three braking surfaces in the radial direction of the cylinder by the control unit each of the at least three braking surfaces being disposed at the innermost position within the radially movable range; 13. The control method according to claim 11 or 12, further comprising: moving each of the at least three braking surfaces radially outward based on a load on the motor becoming greater than a threshold value.

14. A wood fuel production method for producing wood fuel using wood raw materials, comprising: Sending the wood raw material supplied inside the cylinder forward with a screw; and restricting forward movement of the wood raw material discharged from the front end of the cylinder by a movement restricting portion, The screw A screw shaft; a screw blade provided on the outer peripheral surface of the screw shaft; a kneading piece provided at a front end of the screw shaft and protruding forward from the front end of the screw shaft, The wood fuel production method includes: The method further includes kneading the wood raw material, whose movement is restricted by the movement restricting unit, with the screw in a kneading region inside the cylinder and forward of the front end of the screw shaft, The movement limiting portion has at least three braking surfaces arranged at a distance from each other in the circumferential direction of the cylinder, each of which presses the wood raw material discharged from the cylinder radially inward of the cylinder, The kneading piece is positioned in the kneading region and kneads the wood raw material.

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