Title: Burner head and gas burning appliance provided with such a burner head
Abstract: Disclosed is a burner head capable of securing heat resistance and durability characteristics and improving the quality of machining at the same time, capable of easily and stably machining a material into a complicated shape. A second metal primary material of the iron family having high workability and first metal primary materials of the SUS family having high heat resistance are rolled out. Their side plate ends are butt-welded by laser to form a one-piece metal flat-plate material. A press molding machine is operated to press mold recessed portions of a pair of plate members simultaneously with cutting along a contour line. Then, folding is carried out, and they are closely joined together. A gas passage is formed by a recessed portion of the second metal primary material section. A burner port is formed by a recessed portion of the first metal primary material section.
Patent Number: 6,979,192 Issued on 12/27/2005 to Ikuta, et al.
| Inventors:
|
Ikuta; Minoru (Hyogo, JP);
Uehara; Kozo (Kakogawa, JP);
Tanba; Shunji (Akashi, JP);
Nakamura; Akinobu (Himeji, JP)
|
| Assignee:
|
Noritz Corporation (Hyogo, JP)
|
| Appl. No.:
|
600196 |
| Filed:
|
June 20, 2003 |
Foreign Application Priority Data
| Dec 11, 2002[JP] | 2002-359159 |
| Current U.S. Class: |
431/354 |
| Intern'l Class: |
F23D 014/62 |
| Field of Search: |
431/160,284,354,326,328,329
29/890.02
|
References Cited [Referenced By]
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| 3412940 | Nov., 1968 | Tredicesimo.
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| 3758265 | Sep., 1973 | Hein.
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| 4029936 | Jun., 1977 | Schweitzer.
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| 4048290 | Sep., 1977 | Lee.
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| 4624631 | Nov., 1986 | Kobayashi et al.
| |
| 5104309 | Apr., 1992 | Krieger.
| |
| 6325619 | Dec., 2001 | Dane.
| |
| 6769176 | Aug., 2004 | Hornby.
| |
| 2001/0036610 | Nov., 2001 | Wood.
| |
| Foreign Patent Documents |
| 0 308 110 | Mar., 1989 | EP.
| |
| 2 143 024 | Jan., 1985 | GB.
| |
| 55-152307 | Nov., 1980 | JP.
| |
| 62-134409 | Jun., 1987 | JP.
| |
| 07-127819 | May., 1995 | JP.
| |
| 07-158822 | Jun., 1995 | JP.
| |
| 07-190317 | Jul., 1995 | JP.
| |
| 08-233223 | Sep., 1996 | JP.
| |
| 11-063432 | Mar., 1999 | JP.
| |
Primary Examiner: Gravini; Stephen
Attorney, Agent or Firm: Jordan and Hamburg LLP
Claims
1. A burner head comprising:
a gas passage and a plurality of burner ports;
first and second planar metal sheets, each sheet having an internal face, each
sheet comprising first and second portions, said first and second portions connecting
at a substantially linear boundary, said first portion is formed of a first metal
material and second portion is formed of a second metal material, said first material
being different from said second material;
said first portion of said first sheet including a depression for defining a
portion of said plurality of burner ports and said second portion of said second
sheet including a depression for defining a portion of said gas passage, said gas
passage connecting with said burner ports at said boundary;
said first portion of said second sheet including a depression for defining a
further portion of said plurality burner ports and said second portion of said
first sheet including a depression for defining a further portion of said gas passage,
said gas passage connecting with said burner ports at said boundary; and
said internal face of said first sheet connecting against said internal face
of said second sheet for forming said gas passage and said plurality of burner ports.
2. The burner head as set forth in claim 1, wherein:
said metal flat-plate material is a combination of a first metal primary material
having high heat resistance and a second metal primary material having high workability, and
said burner-port constituting region and said gas-passage constituting region
are formed, by press molding, in a first section of said metal flat-plate material
which is formed of said first metal primary material and in a second section of
said metal flat-plate material which is formed of said second metal primary material, respectively.
3. The burner head as set forth in either claim 2, wherein:
said metal flat-plate material is comprised of different types of plate-like
metal primary materials of different characteristics, said different types of plate-like
metal primary materials being united together at end edges thereof in the same
plane by butt-welding.
4. The burner head as set forth in claim 3, wherein:
each said end edge of said plurality of plate-like metal primary materials extends
straightway so that a butt-welding region of said metal flat-plate material extends
straightway, and
said butt-welding region is located at such a position between said burner-port
constituting region and said gas-passage constituting region that said burner-port
and gas-passage constituting regions each undergo a minimum variation in shape.
5. The burner head as set forth in claim 3, wherein:
said butt-welding operation is carried out by laser welding.
6. A gas burning appliance comprising a burner head as set forth in any one of 2.
7. The burner head of claim 1, wherein said first and second planar sheets are
a single sheet joined at a centerline.
8. The burner head of claim 1, wherein said first and second planar sheets are
separate sheets.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a burner head for use in gas burning
appliances such as water heaters, combustion equipment, et cetera. This invention
relates more particularly to a burner head formed by joining together press-molded
metal plate materials.
2. Description of the Related Art
It is well known in the prior art to form a burner head for use in gas burning
appliances, first by superimposing inner and outer plates to be disposed interiorly
and then by joining together the plates to a unit by means of spot welding or laser
welding from the side (see Japanese Patent laid open Gazette No. 7(1995)-158822).
More specifically, the inner and outer plates are each formed by press molding
a sheet of metal material plate and the thus press-molded metal material plates
are placed one over the other and are assembled together. Thereafter, the plates
are welded together in the way as described above.
SUMMARY OF THE INVENTION
In the above-described conventional burner head, all of plates constituting the
burner head are each formed by press molding of a single sheet of metal plate material
of high heat resistance (e.g., material of the stainless steel family). This means
that complicated recessed portions and recessed grooves for forming burner ports,
gas passages, and so on must be formed by press molding of the above-described
material which is relatively hard and poor in workability. This accordingly causes
difficulties in providing stable and exact formation of a gas passage having a
complicated shape. In addition, the occurrence of cracking may cause impairment
of the process yield. Furthermore, the material used is costly, thereby increasing
the production cost (material cost) of a burner head, and the production cost of
gas burning appliances provided with a burner head is likely to increase.
Bearing mind in the above-described circumstances, the present invention
was made. Accordingly, a major object of the present invention is to provide a
burner head and gas burning appliance capable of making the ensuring of heat resistance
and durability characteristics compatible with the improvement in the quality of
machining, capable of easily and stably machining a material into a complicated
shape, and capable of reducing the cost of production.
In order to achieve the above object, the present invention basically employs
the following problem-solving means. To sum up, the wall material, of which a burner
port, a gas passage, et cetera of a burner head are formed, is not comprised of
a single kind of primary material, in other words the wall material is comprises
of different primary materials of different characteristics suitable for the formation
of a burner port and for the formation of a gas passage, respectively.
A first invention provides a specific problem-solving means which relates to a
burner head. More specifically, this problem-solving means is directed to a burner
head comprising a gas passage and a burner port which are formed, by joining together
oppositely-arranged plate members either or both of which are provided with recessed
potions having shapes corresponding to the gas passage and to the burner port respectively,
between the plate members. In the burner head of the first invention, regions of
at least one of the plate members that is provided with the recessed portions,
for formation of the gas passage and the burner port, are each formed of a respective
metal primary material having characteristics selected according to each region,
and the entire plate member is formed of a single sheet of metal flat-plate material
formed by uniting different types of plate-like metal primary materials having
different characteristics.
In accordance with the first invention, the plate member used to form a burner
head is formed of metal primary materials having characteristics suitable for a
region for formation of a burner port and for a region for formation of a gas passage
respectively. Stated another way, the burner-port constituting region is comprised
of a metal primary material of high heat resistance and, on the other hand, the
gas-passage constituting region is comprised of a metal primary material suitable
for machining of a complicated shape. As a result of such arrangement, while allowing
the burner head to maintain adequate heat resistance and durability characteristics,
it is possible to form a complicated shape with accuracy and ease. Therefore, it
becomes possible to manufacture and provide a high-performance, high-quality burner
head. Besides, it is unnecessary to use an expensive metal primary material of
high heat resistance for the entire plate member. Lowering the cost of material
reduces the cost of production.
By "characteristics selected according to each region" is meant characteristics
selected in consideration of minimum required characteristics, optimum characteristics,
characteristics acceptable for the cost of material and so on. Additionally, it
suffices if, when a plate member provided with recessed portions having shapes
corresponding to a gas passage and to a burner port respectively and a flat plate
member are arranged opposing each other and are joined together, the former plate
member in which the recessed portions are formed is comprised of a metal flat-plate
material as set forth in the present invention. On the other hand, it suffices
if, when a pair of plate members both of which are provided with recessed portions
are arranged opposing each other and are joined together, the pair of plate members
are each comprised of a metal flat-plate material of the present invention.
In an example of an embodiment of the first invention, the metal flat-plate material
comprises a combination of a first metal primary material having high heat resistance
and a second metal primary material having high workability characteristics, and
the burner-port constituting region (for example, the burner port and regions in
the vicinity of the burner port) and the gas-passage constituting region are formed,
by press molding, in a first section of the metal flat-plate material which is
formed of the first metal primary material and in a second section of the metal
flat-plate material which is formed of the second metal primary material, respectively.
As a result of such arrangement, it becomes possible to realize the characteristics
of a metal primary material to be selected according to each of the burner-port
and gas-passage constituting regions. This further ensures realization of the operation/working-effect
of the present invention.
Furthermore, the metal flat-plate material, used to form a plate member
of a burner head of the present invention, is concretely specified in the light
of its manufacture method. The metal flat-plate material is manufactured by uniting,
by means of butt welding, different types of plate-like metal primary materials
at end edges thereof in the same plane. This ensures formation of a metal flat-plate
material by the use of different types of metal primary materials of different
characteristics for each region. Furthermore, a butt welding operation in this
case will be specified. End edges of each of the plural plate-like metal primary
materials extend straightway, and it is set such that a butt-welding region of
the metal flat-plate material extend straightway, and it is set such that the butt-welding
region is located at such a position between the burner-port constituting region
and the gas-passage constituting region that the variation in shape of each of
the burner-port and gas-passage constituting regions becomes minimum. This makes
it possible to stabilize not only the quality of a section of the metal flat-plate
material extending as the butt-welding region but also the quality of a plate member
having a welding region. Besides, possible harmful effects due to the presence
of a butt-welding region are also eliminated. Furthermore, as the foregoing butt
welding, TIG (Tungsten Insert Gas) arc welding may be employed. Also, laser welding
may be employed. Since the above-described welding technique in which base metals
of metal primary materials are melted and welded together is employed, this makes
it possible to form a plate member using only the original metal primary material
which does not contain materials such as welding materials.
A second invention provides a problem-solving means which relates to a gas burning
appliance. The gas burning appliance of the second invention employs a burner head
according to the first invention which has been described as a gas burning appliance.
In accordance with the second invention, the burner head maintains resistance to
high heat and durability characteristics and is provided with a gas passageway
formed with high dimensional accuracy because of the improvement in workability.
This makes it possible to provide a gas burning appliance of stable combustion
performance quality. In addition, by virtue of lowering the cost of production
of a burner head, the total cost of production of a gas burning appliance is also reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified cross-sectional explanatory diagram of a water heater
to which an embodiment of the present invention is applied;
FIG. 2 is an exploded perspective view of a burner head and a manifold unit;
FIG. 3 is a top plan view of the burner head;
FIG. 4 is a top plan view for providing an explanation of a method of manufacture
for the burner head of FIG. 3; and
FIG. 5 is a diagram similar to FIG. 4 but shows a different manufacture method
from the one shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of the present invention will be described
with reference to the drawings.
Referring first to FIG. 1, there is shown an instantaneous gas water heater
as a gas burning appliance provided with a burner head according to an embodiment
of the present invention. The reference numeral
1 denotes a housing. The
reference numeral
1a denotes a front cover of the housing
1.
The reference numeral
2 denotes a air blower fan for supplying air for combustion.
The reference numeral
3 denotes a combustion storage water heater body in
which is contained a combustion burner. The reference numeral
4 denotes
a heat exchange storage water heater body disposed above the combustion storage
water heater body
3 and containing therein piping of a heat exchanger (not
shown). Tap water is fed into the heat exchanger. Hot water heated by combustion
heat in the combustion storage water heater body
3 is supplied to a hot
water tap or the like.
A predetermined number of burner heads
5 (not less than two) constituting
a combustion burner are arrayed side by side within the combustion storage water
heater body
3, in other words, the burner heads
5 are disposed on
the far side (in the direction orthogonal to the paper surface of FIG. 1) of the
combustion storage water heater body
3. Interposed between these burner
heads
5 and a fuel gas supply system
6 is a manifold unit
7.
By virtue of the manifold unit
7, fuel gas from the fuel gas supply system
6 is distributed individually to each burner head
5.
Each burner head
5, as shown in FIG. 2, comprises a gas passage
51
having an opening
511 extending toward an end of a corresponding nozzle
part
71 of the manifold unit
7 and disposed face to face with the
nozzle part
71 with a predetermined gap therebetween, and burner ports
52
opening upwardly by which a mixture of fuel gas and air introduced from the gas
passage
51 is burned together with air drawn thereinto. FIG. 2 shows only
one burner head
5. Each burner head
5 is connected to a respective
nozzle part
71.
The fuel gas supply system
6 supplies fuel gas, pressure-delivered through
a city gas pipe or from a gas container (not shown), to main gas supply ports
72,
72 of the manifold unit
7 (see FIG. 2). The thus-supplied fuel gas
passes through an internal passage of the manifold unit
7 and is ejected
toward the opening
511 of the gas passage
51 of the burner head
5
from the nozzle part
71. During ejection of the fuel gas in the direction
of the opening
511, air forced into the combustion storage water heater
body
3 by the air blower fan
2 (see FIG. 1) is drawn from the gap
to form a fuel-gas mixture and, at the same time, is introduced to the gas passage
51.
FIG. 3 shows details of a burner head
5. The burner head
5 comprises
at least a pair of plate members
8,
8. More specifically, the burner
head
5 is formed by superimposing a pair of plate members
8,
8
arranged opposing each other and then by joining them together (see also FIG. 1).
Each plate member
8 is provided with recessed portions
81,
82
from which the gas passage
51 and each burner port
52 are formed
by press molding of a specified metal flat-plate material
9 which is described
later. The plate members
8,
8 are arranged opposing each other and
joined together, whereby the gas passage
51 and the burner ports
52
are divisionally formed between the recessed portions
81,
81,
82,
82. In each plate member
8, the recessed portion
81 corresponds
to a region constituting a gas passage
51 and the recessed portion
82
corresponds to a region constituting a burner port
52.
More specifically, in each plate member
8 the recessed portion
81
is shaped like a groove and its upstream end side opens at the opening
511
of the gas passage
51. The recessed portion
81 extends to one side
from a portion corresponding to the opening
511 and then curves upwardly
so that its downstream end side expands in the width direction (horizontal direction
of FIG. 3). On the other hand, the recessed portion
82 is formed such that
it communicates with the downstream end side of the recessed portion
81
for division of the burner ports
52 and opens upwardly (FIG. 3).
Each plate member
8 comprises a first region on the burner port's
52
side (indicated by hatching in FIG. 3) and a second region on the gas passage's
51 side. The first and second regions face each other across a boundary
83 extending straightway between the section of each burner port
52
and the section of the gas passage
51 in the width direction. The first
region is formed of a first metal primary material of high heat resistance and
the second region is formed of a second metal primary material of high workability.
In other words, the section constituting each burner port
52 is comprised
of a material of high heat resistance in order to secure heat resistance and durability
characteristics and, on the other hand, the section constituting the gas passage
51 is comprised of a material having rather high workability than heat resistance
in order to secure dimensional accuracy of the complicated recessed portion
81
for the gas passage
51 formed by press molding. As the first metal primary
material, materials of the stainless steel family (e.g., SUS430) may be employed.
On the other hand, as the second metal primary material, materials of the iron
family (e.g., aluminized steel) may be employed.
Furthermore, the position of the boundary
83 is so set as to
extend straightway at where the recessed portion
82 or recessed portion
81 formed in the plate member
8 by press molding undergoes a minimum
concave/convex shape variation. In the FIG. 3 case, the position is a boundary
between the recessed portion
82 and the recessed portion
81, and
it is set such that the boundary
83 is extended where the greater portion
exclusive of the vicinity of both the side end portions in the width direction
becomes a concave bottom.
Formation of a burner head
5 of the type described above comprises
a first step in which a first metal primary material and a second metal primary
material are united into a single unit (i.e., in the form of a sheet of metal flat-plate
material), a second step in which a plate member
8 is formed by subjecting
the metal flat-plate material to a press molding process for formation of shapes
of recessed portions
81,
82 and by cutting from the metal flat-plate
material, and a third step in which plate members
8,
8 are joined
together to assemble a burner head
5.
The above will be described more specifically. Referring now to FIG. 4, there
is illustrated a case in which a united body, made up of a pair of plate members
8,
8 continuously connected together at their lower edge portions
84 (see FIG. 3), is formed by press molding. In the first place, a second
band plate-like metal primary material
92 is rolled out from a roll to a
middle position. At the same time, first band plate-like metal primary materials
91 (band plate-like sections indicated by hatching in FIG. 4) are likewise
rolled out from respective rolls so that they are located on both sides of the
second metal primary material
92. These three metal primary materials
91,
92,
91 are conveyed, at constant velocity, from the respective rolls
(the right-hand side in FIG. 4) toward the downstream side (the left-hand side
in FIG. 4). And, the adjoining plate ends are butted against each other in the
same plane and these butted portions are butt welded by means of laser welding
machines
10,
10. This forms a metal flat-plate material
9
with its butt welding regions
11,
11 extending straightway toward
the downstream side.
In the next place, the metal flat-plate material
9 is passed to the downstream
side at a constant velocity and, in synchronization with this, a press molding
machine (not shown) is operated to form recessed portions
81,
81,
82,
82 at predetermined positions. This is followed by cutting along
a contour line
12. At this time, the relative position relationship between
the press molding machine and the metal flat-plate material
9 is set such
that each butt welding region
11 is located in the boundary
83 of
FIG. 3.
And, a folding operation is carried out along a folding line
84a so
that the plate members
8,
8 are located face to face with each other.
Then, the plate members
8,
8 are closely joined together. Additionally,
joint flange portions
851-
855 are folded from one side so as to embrace
the other ones, and they are closely joined together. In the way as described above,
the burner head
5 is formed.
As has been described above, since the recessed portion
81 which becomes
a gas passage
51 is press molded in the second metal primary material
92
of high workability, this makes it possible to form the recessed portion
81
into an exact shape by a high dimensional accuracy machining process. This prevents
not only the variation in the quality of machining but also the occurrence of defective
products, thereby making it possible to provide improvements in the quality of
machining. Besides, because of realization of a shape as designed it becomes possible
to provide a combustion performance as intended. Furthermore, since the recessed
portion
82 which becomes a burner port
52 is formed of the first
metal primary material
91 of high heat resistance, this makes it possible
for the burner head
5 to maintain the same heat resistance and durability
characteristics as previously.
In the case that an inner plate member is imposed between a pair of plate members
8,
8 joined together as the burner head
5, preferably the
inner plate member is formed such that, as in each plate member
8 described
above, a region on the side of the burner port
52 is formed of the first
metal primary material and a region on the side of the gas passage
51 is
formed of the second metal primary material.
It should be noted that the present invention is not limited to the foregoing
embodiment. The present invention includes other various embodiments. In the foregoing
embodiment, a pair of plate members
8,
8 in the form of a one-piece
body is press molded. However, it may be arranged such that press molding is carried
out for each plate member
8. In this case, for example as shown in FIG.
5, it suffices if a first band plate-like metal primary material
91 and
a second band plate-like metal primary material
92 are adjacently passed
from the right-hand side to the left-hand side of FIG. 5, and their plate ends
are butt welded together by a laser welding machine
10 to form a metal flat-plate
material
9a. Then, a metal mold corresponding to a single plate member
8 is used to form recessed portions
81,
82 by press molding.
Cutting is carried out along a contour line
12a. An another plate
members
8 thus press molded and cut are joined together with the above single
plate member
8.
Finally, in the foregoing embodiments the description has been made in terms
of the case in which the metal flat-plate material
9 (
9a)
is passed or run while being subjected to a press molding process, which however
is not deemed restrictive. Alternatively, it may be arranged such that a rectangular
metal flat-plate material having a given length is formed by a separate step and
press molding is carried out for each metal flat-plate material in the next step.
*
