Wood stove

Abstract

To provide an outdoor wood stove that is improved in combustion efficiency.SOLUTION: A wood stove is provided with an internal duct 21 in an upper part of a combustion chamber 3 so as to generate secondary combustion by mixing an unburnt gas generated by primary combustion with secondary combustion air discharged from a secondary combustion air discharging port 26 of the internal duct 21, thereby improving combustion efficiency by reducing exhaust loss and suppressing consumption of firewood used as a fuel.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to a wood stove for outdoor use. [Background technology]

[0002] Patent Document 1 discloses a wood stove used as a radiator for a tent sauna. This wood stove (hereinafter referred to as a "conventional wood stove") is configured so that multiple heat absorbing blades are attached to the inner side of the top wall, and the heat generated in the combustion chamber is transferred to the top wall through the heat absorbing blades, thereby efficiently heating the top wall. Furthermore, the conventional wood stove has a double structure with air layers on the left and right side walls of the main body, making it difficult for the heat generated in the combustion chamber to be transferred to the outer side walls. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3238802 Summary of the Invention [Problem to be solved by the invention]

[0004] By the way, wood stoves used outdoors need to reduce exhaust loss and improve combustion efficiency to reduce consumption of firewood as fuel. However, with conventional wood stoves, unburned gas generated in the primary combustion is exhausted from the combustion chamber without being re-burned, making it difficult to improve combustion efficiency.

[0005] An object of the present invention is to improve the combustion efficiency of a wood stove used outdoors. [Means for solving the problem]

[0006] The wood stove of the present invention is a wood stove with a housing formed into a rectangular parallelepiped, and has a primary combustion air intake section that takes in primary combustion air into a combustion chamber, a secondary combustion air intake section that takes in secondary combustion air into the combustion chamber, a chimney opening provided on the upper part of the housing and discharging gas in the combustion chamber to the outside, and legs provided on the lower part of the housing and movable between a grounded position and a stored position, and the secondary combustion air intake section has a side duct provided on the side of the housing and takes in secondary combustion air from the outside, and an internal duct provided inside the combustion chamber and discharging the secondary combustion air taken in from the side duct into the combustion chamber. The internal duct is defined by an upper plate, a lower plate, and side plates on both the left and right sides of the combustion chamber. It is characterized by: Effect of the Invention

[0007] According to the present invention, the combustion efficiency of a wood stove used outdoors can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a front view of the wood stove according to the present embodiment. [Diagram 2] FIG. 2 is a plan view of the wood stove according to the present embodiment. [Diagram 3] This is a right side view of the wood stove of this embodiment. [Figure 4] This is a bottom view of the wood stove of this embodiment. [Diagram 5] This is a rear view of the wood stove of this embodiment. [Figure 6] This is an exploded oblique view of the housing of the wood stove of this embodiment. [Figure 7] This is an explanatory diagram of this embodiment, a conceptual diagram of the front of a wood stove. [Figure 8] This is an explanatory diagram of this embodiment, a conceptual diagram of the right side of a wood stove. [Figure 9] 9 is a view taken along the arrow AA in FIG. 8. [Figure 10] FIG. 9 is a view taken along the arrow BB in FIG. 8. [Figure 11]FIG. 4 is an explanatory diagram of the embodiment, illustrating the operation of the wheel portion. [Figure 12] FIG. 13 is an explanatory diagram of the embodiment, being a rear view showing a state in which the side panel has been moved inward. [Figure 13] FIG. 2 is an explanatory diagram of the present embodiment, showing a front view of the chimney stand. [Figure 14] FIG. 2 is an explanatory diagram of this embodiment, showing a right side view of the chimney stand. [Figure 15] FIG. 2 is an explanatory diagram of the present embodiment, and is an exploded perspective view of the stone guard. [Figure 16] FIG. 13 is an explanatory diagram of the embodiment, and is a front view showing a state in which the side panel has been moved inward. [Figure 17] FIG. 2 is an explanatory diagram of the present embodiment, and is a right side view showing a state during transportation. [Figure 18] FIG. 2 is an explanatory diagram of the present embodiment, illustrating the flow of gas in a combustion chamber. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the present invention will now be described with reference to the accompanying drawings. Here, we will explain a wood stove 1 for a tent sauna used outdoors. For convenience, the "left side" and "right side" in Fig. 1 will be referred to as the "left side" and "right side", the "upper side" and "lower side" in Fig. 1 will be referred to as the "upper side" and "lower side", and the "left side" and "right side" in Fig. 3 will be referred to as the "front side" and "rear side".

[0010] As shown in FIG. 6, the wood stove 1 has a rectangular parallelepiped housing 2 composed of a top plate 5, side portions 11R and 11L, a front portion 31, a back portion 41, and a bottom portion 51. As shown in FIG. 9 or 10, the right side portion 11R has an inner side plate 12R (side wall) and an outer side plate 13R (side wall) arranged at a certain interval in the left-right direction. A side duct 14R (secondary combustion air passage) is formed between the inner side plate 12R and the outer side plate 13R. On the other hand, the left side portion 11L has an inner side plate 12L (side wall) and an outer side plate 13L (side wall) arranged at a certain interval in the left-right direction. A side duct 14L (secondary combustion air passage) is formed between the inner side plate 12L and the outer side plate 13L.

[0011] As shown in Fig. 6, the front portion 31 has an inner front frame 32 and an outer front panel 33. The front frame 32 has a window portion 34 (see Fig. 1) made of heat-resistant glass through which the combustion chamber 3 (see Fig. 18) can be viewed from the outside. The front frame 32 has a door portion 35 provided below the window portion 34, which can be opened to face the firewood stand 4 (see Fig. 7) in the combustion chamber 3. As shown in Fig. 7, a primary combustion air intake 36 is formed in the lower portion of the front portion 31 to take in primary combustion air from the outside into the combustion chamber 3.

[0012] As shown in FIG. 6, the rear part 41 has an inner rear frame 42 and an outer rear panel 43. The bottom part 51 has a bottom frame 52 and a bottom plate 53. As shown in FIG. 4, the wood stove 1 has movable legs 54 (legs) provided at the four corners of the bottom frame 52 and rotatable between a storage position (see FIG. 11) stored in the bottom part 51 and a grounding position (see FIG. 8) grounded on the ground. The two legs 54 arranged on the front side are rotated from the storage position in the clockwise direction in FIG. 8 around the axis X1 to extend outward from the housing 2 and are positioned at the grounding position by abutting against the front frame 32. The two legs 54 arranged on the rear side are rotated from the storage position in the counterclockwise direction in FIG. 8 around the axis X2 to extend outward from the housing 2 and are positioned at the grounding position by abutting against the rear frame 42.

[0013] As shown in FIG. 11 or 12, the wood stove 1 has a wheel section 55 provided at the bottom of the housing 2. The wheel section 55 has wheels 56 that are grounded when moving (traveling) on ​​the ground, and an arm 57 whose one end is connected to the rear frame 42 and whose other end has the wheels 56 attached. The arm 57 rotates around the axis X3 relative to the housing 2 (rear frame 42) and abuts against the bottom frame 52 to be positioned at a moving (traveling) position when moving the wood stove 1 (housing 2). As shown in FIG. 1 or 11, a handle 6 that can be pulled out in the front-rear direction is provided at the top of the housing 2. The handle 6 can be attached to either the right or left side (FIG. 1 shows the case where "left side" is selected).

[0014] 8 to 10, the combustion chamber 3 is defined by the top plate 5, the inner side plates 12R and 12L, the front frame 32, the rear frame 42, and the bottom frame 52. The right side duct 14R is defined by the top plate 5, the inner side plate 12R, the outer side plate 13R, the front frame 32, the rear frame 42, and the bottom frame 52. The left side duct 14L is defined by the top plate 5, the inner side plate 12L, the outer side plate 13L, the front frame 32, the rear frame 42, and the bottom frame 52.

[0015] An internal duct 21 (secondary combustion air passage) is provided at the top of the combustion chamber 3. The internal duct 21 is defined by the inner side plates 12R, 12L, an upper plate 22 installed between the side plates 12R, 12L, a lower plate 28 arranged at a fixed distance from the upper plate 22, and a rear frame 42. The upper plate 22 has a horizontal portion 23 extending forward from the rear frame 42, and an inclined portion 24 extending from the horizontal portion 23 forward and obliquely upward at a gentle incline. The inclination angle of the inclined portion 24 with respect to the horizontal portion 23 is, for example, 10 degrees.

[0016] The upper plate 22 has a bent portion 25 formed by bending the front end of the upper plate 22 at a right angle toward the lower plate 28. The lower edge of the bent portion 25 of the upper plate 22 abuts against the front edge of the lower plate 28. In other words, the opening at the front end of the internal duct 21 is closed by the bent portion 25 of the upper plate 22. The bent portion 25 has multiple (shown as "9" in FIG. 9) secondary combustion air discharge ports 26 formed by cutting out the lower edge portion in a semicircular shape. The right edge portions of the upper plate 22 and the lower plate 28 are joined to the inner side plate 12R. The left edge portions of the upper plate 22 and the lower plate 28 are joined to the inner side plate 12L.

[0017] A plurality of secondary combustion air intakes 15 (secondary combustion air external intakes) (only "12" of the side panel 13R are shown in FIG. 8) are formed in the lower part of the outer side panels 13R and 13L to take in secondary combustion air from the outside to the side ducts 14R and 14L. The secondary combustion air intakes 15 are formed in a circular shape and are arranged at regular intervals in the front-rear direction. A plurality of secondary combustion air intakes 16 (only "20" of the side panel 12R are shown in FIG. 8) are formed in the upper part of the inner side panels 12R and 12L to take in secondary combustion air from the side ducts 14R and 14L to the internal ducts 21R and 21L. The secondary combustion air intakes 16 are formed in a circular shape and are arranged at regular intervals in the front-rear direction along the internal ducts 21 (secondary combustion air passage).

[0018] A certain space 27 is formed between the top plate 5, the front frame 32, and the front end of the internal duct 21 (secondary combustion air outlet 26). A reinforcing member 7 is provided at the upper part of the space 27, which is joined to the underside of the top plate 5 and extends rearward from the front frame 32. A plurality of reinforcing members 7 (two in this embodiment) are arranged at intervals in the left-right direction, with the rear ends extending beyond the secondary combustion air outlet 26. The reinforcing member 7 has a V-shaped cross section.

[0019] As shown in Fig. 8, a chimney stand 61 is provided on the upper part of the combustion chamber 3. The chimney stand 61 is supported by the horizontal part 23 of the upper plate 22 that constitutes the internal duct 21. As shown in Fig. 13 or 14, the chimney stand 61 has a rectangular plate 62 arranged parallel to the rear frame 42, and a rectangular plate 63 arranged parallel to the side plates 12R, 12L. The chimney stand 61 is configured in a cross shape (see Fig. 1) in a plan view by inserting the plates 62, 63 into slits (not shown) formed in the mating plates 63, 62.

[0020] The chimney stand 61 has three slits 64 formed in the plates 62 and 63 and one notch 65 formed in the rear end of the plate 63. The three slits 64 and one notch 65 are arranged on a circle in a plan view, and extend downward (vertically) from the upper ends of the plates 62 and 63 at a certain width and distance. The chimney 60 is inserted into the three slits 64 and one notch 65 of the chimney stand 61 and is supported by being abutted against the lower ends of the three slits 64 and one notch 65. The top plate 5 is formed with a circular opening 8 (chimney mouth) for inserting the chimney 60. In addition, the lower part of the chimney stand 61 is formed with a plurality of openings 66 (in this embodiment, "two for each of the plates 62 and 63") that communicate with the combustion chamber 3 and the chimney 60 (outside the housing 2).

[0021] As shown in Figs. 1 to 3 and 15, the wood stove 1 has a stone guard 71 that is provided to surround sauna stones (not shown) placed on the top plate 5. The stone guard 71 has side panels 72R, 72L, a front panel 73, and a back panel 74. The side panel 72R has connecting parts 75F, 75R (only the front "connecting part 75F" is shown in Fig. 15) formed at the lower ends on both the front and rear sides, which are rotatably connected to the front and rear sides of the right end of the top plate 5. The side panel 72L has connecting parts 76F, 76R formed at the lower ends on both the front and rear sides, which are rotatably connected to the front and rear sides of the left end of the top plate 5. In other words, the side panels 72R, 72L are connected to the top plate 5 so as to be tiltable.

[0022] As shown in Fig. 15, vertical slits 77F, 77R with open upper ends are formed on both the front and rear sides of the upper end of the side panel 72R. Vertical slits 78F, 78R with open upper ends are formed on both the front and rear sides of the upper end of the side panel 72L. Protrusions 79R, 79L protruding to the right and left are formed on the upper end of the front panel 73. Protrusions 80R, 80L protruding to the right and left are formed on the upper end of the back panel 74.

[0023] The stone guard 71 is configured in a shape (rectangular in plan view) that surrounds the sauna stones (not shown) on all four sides by inserting the protrusions 79R, 79L of the front panel 73 into the slits 77F, 78F of the side panels 72R, 72L with the side panels 72R, 72L raised, and inserting the protrusions 80R, 80L of the back panel 74 into the slits 77R, 78R of the side panels 72R, 72L.

[0024] As shown in Figs. 1, 5, and 6, the wood stove 1 has a side panel 83R that covers the right side portion 11R of the housing 2, and a side panel 83L that covers the left side portion 11L of the housing 2. As shown in Fig. 7, the front end of the side panel 83R is formed with mounting portions 84R, 85R that protrude inward from both upper and lower ends. As shown in Fig. 12, the rear end of the side panel 83R is formed with mounting portions 90R, 91R that protrude inward from both upper and lower ends. The mounting portions 84R, 85R and the mounting portions 90R, 91R are formed with elongated holes 87 through which screws 86 are inserted to fix the side panel 83R to the front panel 33 and the rear panel 43. The elongated holes 87 have a horizontal hole portion 88 and an inclined hole portion 89 that extends diagonally upward and inward from the inner end of the horizontal hole portion 88.

[0025] As shown in FIG. 7, the front end of the side panel 83L is provided with mounting parts 84L, 85L that protrude inward from both upper and lower ends. As shown in FIG. 12, the rear end of the side panel 83L is provided with mounting parts 90L, 91L that protrude inward from both upper and lower ends. The mounting parts 84L, 85L and the mounting parts 90L, 91L are provided with elongated holes 87 through which screws 86 are inserted to fix the side panel 83L to the front panel 33 and the rear panel 43. The elongated holes 87 have a horizontal hole part 88 and an inclined hole part 89 that extends obliquely upward and inward from the inner end of the horizontal hole part 88. The side panel 83L is formed symmetrically with respect to the side panel 83R.

[0026] When using the wood stove 1 (when burning firewood 9 in the combustion chamber 3, see FIG. 18), the screw 86 is positioned at the inner end of the inclined hole portion 89 of the elongated hole 87 as shown in FIG. 7. In this state, the distance between the side panel 83R and the side plate 13R and the distance between the side panel 83L and the side plate 13L, and therefore the width of the wood stove 1, are maximized. On the other hand, when storing the wood stove 1 (for example, when transporting it on the bed of a vehicle), the screw 86 is positioned in the horizontal hole portion 88 of the elongated hole 87. In this state, the distance between the side panel 83R and the side plate 13R and the distance between the side panel 83L and the side plate 13L, and therefore the width of the wood stove 1, are minimized.

[0027] The side panels 83R, 83L are formed with a plurality of ventilation holes 92 for introducing secondary combustion air between the side panel 83R and the outer side plate 13R, and between the side panel 83L and the outer side plate 13L. The side panels 83R, 83L are also formed with notches 93 for avoiding collision with the wheels 56 when the side panels 83R, 83L are opened (see FIG. 7).

[0028] Next, the operation of this embodiment will be described. When the wood stove 1 is transported on the bed of a vehicle (hereinafter referred to as "during transportation"), it is advantageous to minimize the height (vertical dimension) and width (lateral dimension) of the wood stove 1. At this time, as shown in FIG. 11, the movable legs 54 (legs) are stored inside the bottom frame 52. The wheels 56 are placed behind the rear panel 43. Furthermore, the side panels 83R, 83L are fixed at their inner positions (see FIG. 16). The stone guard 71 has the front panel 73 and rear panel 74 pulled out from the slits 77F, 78F and slits 77R, 78R of the side panels 72R, 72L, and the side panels 72R, 72L are stacked on the top panel 5.

[0029] When the wood stove 1 is removed from the bed of the vehicle and moved to the sauna tent (hereinafter referred to as "moving"), as shown in FIG. 11, the arm 57 of the wheel section 55 is rotated to abut against the bottom frame 52, so that the wheels 56 are placed under the housing 2 and grounded. When moving, the arm 57 is fixed so that the wheels 56 are located at the position shown by the solid line in FIG. 11 (the fixing method is not shown). Next, as shown in FIG. 17, the handle 6 pulled out from the housing 2 is lifted to lift the front part of the bottom part 51 of the housing 2 from the ground. In this state, the handle 6 is pulled to move the wood stove 1 to the sauna tent. At this time, by setting the two movable legs 54 arranged on the front side of the bottom frame 52 to the moving position (see FIG. 1 and FIG. 3), the housing 2 can be prevented from excessively tilting forward during movement.

[0030] When the wood stove 1 is installed in a sauna tent and used (hereinafter referred to as "in use"), the four movable legs 54 stored in the bottom frame 52 are set to the grounded position, and the housing 2 is supported by the four movable legs 54. Next, as shown in FIG. 7, the side panels 83R, 83L are opened outward and fixed in a state separated from the inner side panels 12R, 12L. Next, the side panels 72R, 72L of the stone guard 71 stacked on the top panel 5 are raised, and the front panel 73 and the back panel 74 are inserted into the slits 77F, 78F and slits 77R, 78R of the side panels 72R, 72L to assemble the stone guard 71. Next, the chimney 60 inserted into the housing 2 from the opening 8 (chimney mouth) of the top panel 5 is attached to the chimney stand 61, and sauna stones are placed on the top panel 5. The handle 6 is stored in the housing 2 at a predetermined timing.

[0031] Next, the firewood 9 on the firewood stand 4 installed at the bottom of the combustion chamber 3 is ignited. The firewood 9 on the firewood stand 4 undergoes primary combustion when primary combustion air (outside air) is supplied through the primary combustion air intake 36 formed in the front portion 31 of the housing 2. Here, the flame (heat) of primary combustion and the top plate 5 are insulated by the upper plate 22 and the lower plate 28 that constitute the internal duct 21, so that the heat generated by the primary combustion is prevented from being used to heat the top plate 5 and being discharged to the outside through the chimney 60.

[0032] On the other hand, as shown in Fig. 18, the unburned gas generated by the primary combustion moves toward the front of the combustion chamber 3 along the lower plate 28 constituting the internal duct 21, and is mixed in the space 27 with the secondary combustion air discharged from the secondary combustion air discharge port 26 of the internal duct 21. The secondary combustion air is discharged from the secondary combustion air discharge port 26 to the space 27 via a plurality of secondary combustion air intakes 15R, 15L (secondary combustion air external intakes) formed on the outer side plates 13R, 13L of the side portions 11R, 11L, the side ducts 14R, 14L, a plurality of secondary combustion air intakes 16R, 16L (secondary combustion air internal intakes) formed on the inner side plates 12R, 12L of the side portions 11R, 11L, and the internal duct 21.

[0033] The unburned gas is mixed with the secondary combustion air and undergoes secondary combustion in the space 27. The high-temperature exhaust gas generated by the secondary combustion moves rearward on the upper plate 22 of the inner duct 21 while heating the top plate 5, and then passes through the opening 66 of the chimney stand 61 and is discharged to the outside from the chimney 60.

[0034] However, with conventional wood stoves, unburned gas generated during primary combustion is exhausted from the combustion chamber without being re-burned (secondary combustion), making it difficult to improve combustion efficiency.

[0035] In contrast, in this embodiment, an internal duct 21 is provided at the top of the combustion chamber 3, and secondary combustion is generated by mixing the unburned gas generated by the primary combustion with secondary combustion air released from the secondary combustion air outlet 26 of the internal duct 21, thereby making it possible to reduce exhaust losses and improve combustion efficiency, and also to reduce consumption of firewood as fuel. In this embodiment, the flame (heat) of the primary combustion and the top plate 5 are blocked by the upper plate 22 and the lower plate 28 that constitute the internal duct 21, so the upper plate 22 and the lower plate 28 can function as baffle plates. This makes it possible to prevent the heat generated by the primary combustion from being discharged to the outside through the chimney 60 without being used to heat the top plate 5, reducing exhaust loss and further improving combustion efficiency. In this embodiment, the wood stove 1 (housing 2) is moved by using wheels 56 that are larger in diameter than the wheels of the casters and are in contact with the ground, so that the wood stove 1 can be easily moved even on unpaved roads. In this embodiment, the movable legs 54 (legs) are configured to be stored in the bottom frame 52 of the housing 2 during transport, so that the height of the wood stove 1 can be kept low, which is advantageous when loading it onto the cargo bed of a vehicle. In this embodiment, the side panels 83R, 83L are configured to move inward during transportation, so the width of the wood stove 1 can be kept small, which is advantageous when loading it onto the bed of a vehicle. In addition, when moving it outward (when in use), the secondary combustion air is properly taken in. [Explanation of symbols]

[0036] 1 wood stove, 2 housing, 3 combustion chamber, 8 opening (chimney opening), 14R, 14L side duct, 15R, 15L secondary combustion air intake, 16R, 16L secondary combustion air intake, 21 internal duct, 36 primary combustion air intake, 54 movable leg (leg)

Claims

1. A wood stove having a rectangular shaped case, A primary combustion air intake section that takes in primary combustion air into the combustion chamber; A secondary combustion air intake section for introducing secondary combustion air into the combustion chamber; a chimney port provided at an upper portion of the housing for discharging gas in the combustion chamber to the outside; a leg portion provided at a lower portion of the housing and movable between a grounding position and a storage position; having The secondary combustion air intake section is A side duct is provided on a side of the housing and takes in secondary combustion air from the outside; an inner duct provided inside the combustion chamber and discharging the secondary combustion air taken in from the side duct into the combustion chamber; having A wood stove characterized in that the internal duct is defined by an upper plate, a lower plate, and side plates on both the left and right sides of the combustion chamber.

2. 2. The wood stove according to claim 1, A wood stove characterized by having a wheel section provided at the bottom of the housing for supporting the housing so that it can be moved.

3. 3. The wood stove according to claim 2, A wood stove characterized in that the wheel section has wheels and an arm whose one end is connected to the lower part of the housing and whose other end is to which the wheels are attached.

4. 4. The wood stove according to claim 3, A wood stove characterized in that the arm is connected to the housing so as to be able to swing in the direction of travel of the housing.

5. 2. The wood stove according to claim 1, The secondary combustion air intake section is a secondary combustion air external intake formed at a lower portion of the side duct; a secondary combustion air internal intake formed on a side of the internal duct; a secondary combustion air outlet formed in a front portion of the internal duct; A wood stove characterized by having:

6. 2. The wood stove according to claim 1, A wood stove characterized in that the side duct has an inner side wall and an outer side wall, and a passage for secondary combustion air is formed between the inner side wall and the outer side wall.

7. 2. The wood stove according to claim 1, A wood stove characterized in that the internal duct is positioned at the top of the combustion chamber and controls the flow of combustion gas generated by primary combustion.

8. 2. The wood stove according to claim 1, A wood stove characterized in that the left and right sides of the housing have side panels that can be moved inward and outward parallel to the side portions of the housing.

Images