burner

Abstract

A burner (1) is provided in which gas supplied from a gas canister (2) is fed to a burner head (3) and combusted. The burner (1) includes a housing (4) including, in its interior, a gas chamber (25) to which gas is fed through a stem (14) of the gas canister (2); a canister holder (10) for retaining the gas canister (2); and a holder cap (11) which is located outside of the flow path of gas, and by which the canister holder (10) is attached to the housing (4) so as to be rotatable at a predetermined angle. The gas chamber (25) is surrounded by a seamless inner wall.

Description

TECHNICAL FIELD

[0001] The present invention relates to a burner used in indoor or outdoor settings.BACKGROUND ART

[0002] For example, a burner as disclosed in the below-identified Patent Document 1 is used for boiling water or cooking in outdoor settings such as camping. This burner is designed such that gas supplied from a replaceable gas canister (hereinafter simply referred to as "gas canister") is fed to a burner head and combusted. This gas canister is retained by a canister holder attached to a housing.

[0003] The canister holder is attached to the housing by being sandwiched between a housing body portion and a divided portion into which the portion of the housing near a gas inlet is divided. A primary gas chamber surrounded by the housing body portion and the divided portion is formed on the side closer to the distal end of a stem of the gas canister. (see Fig. 1 of Patent Document 1).PRIOR ART DOCUMENT(S)PATENT DOCUMENT(S)

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-229033SUMMARY OF THE INVENTIONPROBLEMS TO BE SOLVED BY THE INVENTION

[0005] In the burner of Patent Document 1, the connection portion between the housing body portion and the divided portion is located within the primary gas chamber. Since the internal pressure of the gas canister acts directly on this connection portion, it is essential to provide a seal member such as an O-ring in order to ensure airtightness at this connection portion, and high component precision and assembly precision are required for the housing body portion and the divided portion. This could increase costs.

[0006] In view of the above, it is an object of the present invention to provide a burner capable of ensuring, with a simple structure, the airtightness of a gas chamber into which gas supplied from a gas canister is introduced.MEANS FOR SOLVING THE PROBLEMS

[0007] In order to achieve the above object, the present invention provides a burner configured such that gas supplied from a gas canister is fed to a burner head and combusted, characterized in that the burner comprises: a housing including, in an interior of the housing, a gas chamber to which gas is fed through a stem of the gas canister; a canister holder for retaining the gas canister; and a holder cap which is located outside of a flow path of gas, and by which the canister holder is attached to the housing so as to be rotatable at a predetermined angle, wherein the gas chamber is surrounded by a seamless inner wall (first arrangement).

[0008] With this arrangement, it is possible to ensure, with a simple structure, the airtightness of the gas chamber into which gas supplied from the gas canister is introduced.

[0009] In the first arrangement, a second arrangement may be used in which the holder cap is made of a resin. If the holder cap, which is located outside of the flow path of gas and which does not require heat resistance, is made of a resin, the weight of the burner can be reduced. This can improve usability in outdoor settings or the like.

[0010] In the first and second arrangements, a third arrangement can be used in which the canister holder is formed with a cutout fitting portion fitted in a cutout formed in a flange of the gas canister, and the canister holder and the gas canister are positioned by turning the canister holder with the cutout fitted to the cutout fitting portion. With this arrangement, vaporized gas can be stably supplied from the gas canister to the burner.

[0011] In the first to third arrangements, a fourth arrangement can be used in which the canister holder is formed with claws inserted inside of the flange, and the holder cap is formed with radially expanded portions, and in which the burner is configured such that when the canister holder is rotated about a center axis relative to the housing, the radially expanded portions enter radially inner sides of the respective claws so as to radially expand the claws or so as to prevent the claws from deflecting radially inward. With this arrangement, the radially expanded claws can be fitted inside of the flange, so that the gas canister can be firmly retained by the canister holder.EFFECTS OF THE INVENTION

[0012] In the burner of the present invention, since the gas chamber is surrounded by a seamless inner wall, it is possible to ensure, with a simple structure, the airtightness of the gas chamber into which gas supplied from the gas canister is introduced.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Fig. 1 is a sectional view of a burner according to an embodiment of the present invention. Fig. 2 is an enlarged sectional view of a portion of the burner illustrated in Fig, 1. Fig. 3 is an exploded perspective view of a portion of the burner illustrated in Fig, 1. BEST MODE FOR CARRYING OUT THE INVENTION

[0014] An embodiment of a burner 1 according to the present invention is now described with reference to the drawings. The burner 1 is a device configured such that gas supplied from a replaceable gas canister 2 (commonly known as a "cassette-type gas canister") is fed to a burner head 3 and combusted. Fig. 1 is a sectional view illustrating an embodiment of the burner 1. Fig. 2 is an enlarged sectional view of a portion of the burner 1. Fig. 3 is an exploded perspective view of a portion of the burner 1.

[0015] The burner 1 includes a housing 4, and the burner head 3 is attached to the housing 4 via an intake pipe 5. The housing 4 is provided with a plurality of legs 6 that also function as a pot stand, and a piezoelectric element 8 for generating a discharge from an ignition wire 7 provided in the burner head 3.

[0016] As illustrated in Fig. 3, a cylindrical portion 9 that opens outward is formed at the portion of the housing 4 to which the gas canister 2 is attached. A canister holder 10 having a through-hole in its center is attached to the cylindrical portion 9. The canister holder 10 is rotatably attached to the housing 4 by a substantially cylindrical holder cap 11 having a through-hole in its center as with the canister holder 10. The holder cap 11 is a separate component provided separately from the housing 4, in which gas flows, and the holder cap 11 is located outside of the flow path of gas. Therefore, heat resistance is not required for its material. Therefore, in this embodiment, a lightweight resin material is used. However, the material of the holder cap 11 is not limited to a resin material. For example, the cap holder 11 may be formed of a sheet metal.

[0017] A T-shaped protrusion 12 is formed on the outer peripheral surface of the cylindrical portion 9. On the other hand, a T-shaped recess 13 in which the protrusion 12 of the cylindrical portion 9 is fitted is formed in the holder cap 11. By fitting the protrusion 12 into the recess 13, the holder cap 11 is non-rotatably fixed to the cylindrical portion 9.

[0018] An O-ring 15 is provided within the opening of the cylindrical portion 9 so as to be located between a stem 14 of the gas canister 2 and the housing 4 with the gas canister 2 attached, and an anti-separation member 16 for preventing separation of the O-ring 15 is also provided within this opening. An O-ring 17 is provided at the open end of the cylindrical portion 9 so as to be located between this open end and the holder cap 11.

[0019] The canister holder 10 is formed with three claws 19 inserted in respective recesses located inside of a flange 18 of the gas canister 2; and a cutout fitting portion 20 fitted in a cutout (not shown) formed in the flange 18. On the other hand, the holder cap 11 includes, on its cylindrical surface, three radially expanded portions 21 corresponding to the respective circumferential locations of the three claws 19 of the canister holder 10. An inclined surface 22 is formed on a circumferential end of each claw 19. A wall portion 23 is formed at each radially expanded portion 21 so as to protrude radially outward from the radially expanded portion 21.

[0020] The gas canister 2 is attached to the canister holder 10 such that with the radially expanded portions 21 of the holder cap 11 located between the respective circumferentially adjacent pairs of claws 19 of the canister holder 10 (with the gas canister detachable), the cutout of the flange 18 is fitted to the cutout fitting portion 20 of the canister holder 10.

[0021] When the canister holder 10 together with the gas canister 2 is rotated about the center axis relative to the housing 4, the claws 19 of the canister holder 10 gradually radially expand due to the abutment between the inclined surfaces 22 at the circumferential ends of the claws 19 and the circumferential ends of the radially expanded portions 21 of the holder cap 11. Then, the radially expanded portions 21 enter the radially inner sides of the claws 19, while preventing the claws 19 from deflecting radially inward. When the gas canister 2 is further rotated until the claws 19 abut against the wall portions 23 of the radially expanded portions 21, the claws 19 radially overlapping with the radially expanded portions 21 are slightly radially expanded due to the action of the radially expanded portions 21 entering the radially inner sides of the claws 19 (gas canister is retained). The radially expanded claws 19 are fitted into the recesses located inside of the flange 18 of the gas canister 2, so that the gas canister 2 is firmly retained by the canister holder 10 (separation of gas canister 2 is prevented). The housing 4 and the canister holder 10 are rotatable relative to each other about the center axis when the state of the gas canister is switched between the detachable state and the retention state.

[0022] As illustrated in the enlarged sectional view of Fig. 2, a regulator 24 for regulating the flow rate of gas is provided in the housing 4. The regulator 24 includes, as the main elements, a gas chamber 25, a valve body 26, a valve seat 27, a diaphragm 28, a counter spring 29, an adjustment spring 30, and a spindle 31.

[0023] The gas chamber 25 is a space into which gas is introduced from the gas canister 2, and the stem 14 of the gas canister 2 is brought into abutment with one end of the gas chamber 25. The gas pressure in the gas chamber 25 is equal to the internal pressure of the gas canister 2. Since the gas chamber 25 is surrounded by a seamless inner wall, even when the internal pressure of the gas canister 2 acts, there is no risk of gas leakage from the interior of the gas chamber 25.

[0024] The valve body 26 is a rod-shaped member axially movably provided in the gas chamber 25. An O-ring 32 is provided at one end of the valve body 26. The valve seat 27 is a substantially cylindrical member provided separately from the housing 4, and fixed in position within the gas chamber 25 so as to be arranged coaxially with the valve body 26, and the valve body 26 is inserted in the valve seat 27. The valve body 26 and valve seat 27 while being combined together in advance are fixed in position within the gas chamber 25 from the side opposite from the side on which the gas cylinder 2 is attached (from the left side in Fig. 2).

[0025] Fig. 2 illustrates a valve closed state in which a tapered surface 33 at one end of the valve seat 27 and the O-ring 32 on the valve body 26 are in abutment with each other. By allowing the valve body 26 to further protrude from the end of the valve seat 27 such that the tapered surface 33 and the O-ring 32 are separated from each other, the valve body 26 is opened. At the respective axial ends of the valve seat 27, minute flow paths 34 each comprising a minute gap are defined between the outer peripheral surface of the valve body 26 and the inner peripheral surface of the valve seat 27 such that gas flows through the minute flow paths 34 in the valve open state of the valve body 26.

[0026] The diaphragm 28 is a disk-shaped member having a through-hole in its central portion, and biasing the valve body 26 in the valve-closing direction while preventing gas from leaking from the interior of the housing 4 to the outside. The outer peripheral edge of the diaphragm 28 is fixed to the housing 4 by being sandwiched between a step formed in the housing 4 and a housing cap 35 screwed toward this step. Also, the inner peripheral edge of the diaphragm 28, which faces the through-hole, is fixed to a coupling member 36 disposed to coaxially abut against the valve body 26, by being sandwiched between a flange formed on the coupling member 36 and a flange formed on a fixing member 37 coaxially inserted in the coupling member 36.

[0027] The counter spring 29 is provided in a space between the outer peripheral surface of the valve body 26 and the inner peripheral surface of the valve seat 27 so as to be located between the valve body 26 and the valve seat 27. The counter spring 29 assists the biasing force in the valve-closing direction that is applied from the diaphragm 28 to the valve body 26.

[0028] The adjustment spring 30 is a member for biasing the valve body 26 in the valve-opening direction via the fixing member 37 and the coupling member 36. The adjustment spring 30 is disposed via a spherical body 38 in the spindle 31, which has a cylindrical shape and a bottom, and an end of the adjustment spring 30 is in abutment with the flange surface of the flange formed on the fixing member 37. The spherical body 38 has a diameter larger than the diameter of the adjustment spring 30.

[0029] The spindle 31 can be screwed into the housing cap 35. By operating a handle 39 provided on the spindle 31 so as to change the amount by which the spindle 31 is screwed into the hosing cap 35, it is possible to adjust the biasing force in the valve-opening direction that is applied to the valve body 26 by the adjustment spring 30, i.e., adjust the valve opening degree of the valve body 26. The spindle 31 is prevented from moving out of the housing cap 35 by a lock nut 40.

[0030] In the valve open state of the valve body 26, gas that has flowed through the minute flow paths 34 reaches a nozzle 42 through a flow path 41 formed along the surface of the diaphragm 28 closer to the valve body 26. The pressure of gas flowing in the flow path 41 is lower than the pressure of gas in the gas chamber 25. When gas is injected from the nozzle 42 into the intake pipe 5, air is drawn in through air inlets 43 formed in the intake pipe 5 due to the injection, thereby generating a mixed gas of gas and air. This mixed gas is discharged from a burner port formed in the burner head 3, and is ignited and combusted by a discharge from the ignition wire 7 in the burner head 3.

[0031] In the burner 1, since the gas chamber 25 in the housing 4 is surrounded by a seamless inner wall, it is not necessary to separately provide a member such as an O-ring for ensuring airtightness within the gas chamber 25, and it is possible to ensure, with a simple structure, the airtightness of the gas chamber 25, into which gas supplied from the gas canister 2 is introduced.

[0032] Also, since the holder cap 11, which is located outside of the flow path of gas and which does not require heat resistance, is made of a resin, the weight of the burner 1 is reduced. This improves usability in outdoor settings or the like.

[0033] Also, in the burner 1, since the canister holder 10 is formed with a cutout fitting portion 20 fitted in a cutout formed in the flange 18 of the gas canister 2, and the canister holder 10 (gas canister 2) is positioned by turning the canister holder 10 with the cutout fitted to the cutout fitting portion 20, vaporized gas can be stably supplied from the gas canister 2 to the burner 1.

[0034] The above-described embodiment is a mere example in every respect, and the present invention is not limited thereto. The scope of the present invention is indicated not by the above description but by the claims, and should be understood to include all modifications within the meaning and scope equivalent to the scope of the claims. The above structure is applicable to various gas devices such as a gas torch that is not provided with regulator 24.DESCRIPTION OF REFERENCE NUMERALS

[0035] 1: Burner 2: Gas canister 3: Burner head 4: Housing 5: Intake pipe 6: Leg 7: Ignition wire 8: Piezoelectric element 9: Cylindrical portion 10: Canister holder 11: Holder cap 12: Protrusion 13: Recess 14: Stem 15, 17, 32: O-ring 16: Anti-separation member 18: Flange 19: Claw 20: Cutout fitting portion 21: Radially expanded portion 22: Inclined surface 23: Wall portion 24: Regulator 25: Gas chamber 26: Valve body 27: Valve seat 28: Diaphragm 29: Counter spring 30: Adjustment spring 31: Spindle 33: Tapered surface 34: Minute flow path 35: Housing cap 36: Coupling member 37: Fixing member 38: Spherical body 39: Handle 40 Lock nut 41: Flow path 42: Nozzle 43: Air inlet

Claims

1. A burner configured such that gas supplied from a gas canister (2) is fed to a burner head (3) and combusted, characterized in that the burner comprises: a housing (4) including, in an interior of the housing (4), a gas chamber (25) to which gas is fed through a stem (14) of the gas canister (2); a canister holder (10) for retaining the gas canister (2); and a holder cap (11) which is located outside of a flow path of gas, and by which the canister holder (10) is attached to the housing (4) so as to be rotatable at a predetermined angle, wherein the gas chamber (25) is surrounded by a seamless inner wall.

2. The burner according to claim 1, wherein the holder cap (11) is made of a resin.

3. The burner according to claim 1 or 2, wherein the canister holder (10) is formed with a cutout fitting portion (20) fitted in a cutout formed in a flange (18) of the gas canister (2), and wherein the canister holder (10) and the gas canister (2) are positioned by turning the canister holder (10) with the cutout fitted to the cutout fitting portion (20).

4. The burner according to any one of claims 1 to 3, wherein the canister holder (10) is formed with claws (19) inserted inside of the flange (18), and the holder cap (11) is formed with radially expanded portions (21), and wherein the burner is configured such that when the canister holder (10) is rotated about a center axis relative to the housing (4), the radially expanded portions (21) enter radially inner sides of the respective claws (19) so as to radially expand the claws (19) or so as to prevent the claws (19) from deflecting radially inward.

Images