JP2020016420A - Combustion device and water heating system - Google Patents

Abstract

To provide a combustion device in which a frame rod has high detection performance, and to provide a water heating system.SOLUTION: A combustion device 200 includes: a burner 30 having a flame hole surface 30b on which multiple burner ports 30a open; a chamber 31 which has an attachment surface 30i, to which the burner 30 is attached, and supplies a mixed gas to the multiple burner ports 30a; and a frame rod 15 which is attached to a flange part 31a of the chamber 31 located at the outer periphery side of the burner 30 in a plan view and includes a core wire 15a. The core wire 15a obliquely extends relative to the attachment surface 31i, penetrates through the chamber 31, and is bent toward the flame hole surface 30b.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a combustion device and a hot water device including the combustion device.

  A combustion device provided with a frame rod for detecting a flame is disclosed in, for example, JP-A-2018-071855 (Patent Document 1). In this combustion device, the flame rod is mounted together with the ignition plug on the side wall of the case of the heat exchanger disposed downstream of the combustion device in the flow direction of the combustion gas. The frame rod is bent, and the end of the frame rod is located closer to the flame hole surface than the portion of the frame rod attached to the case side wall.

JP, 2018-071855, A

  In the combustion device described in the above publication, the frame rod is attached to the side wall of the case of the heat exchanger. The mounting position of the frame rod on the side wall of the case of the heat exchanger is restricted by other components of the heat exchanger such as piping through which hot and cold water flows. Due to this restriction, in the above-described combustion device, the frame rod is disposed relatively far from the flame hole surface of the burner.

  An object of the present invention is to provide a combustion device and a hot water device in which a frame rod has high detection performance.

  A combustion device according to the present invention has a burner having a flame hole surface in which a plurality of flame holes are open, a chamber having a mounting surface to which a burner is mounted, and a chamber for supplying a mixed gas to the plurality of flame holes. A frame rod attached to the outer peripheral portion of the chamber located on the outer peripheral side of the burner in a plan view and including a core wire. The core wire extends obliquely to the mounting surface, penetrates the chamber, and is bent toward the flame hole surface.

  ADVANTAGE OF THE INVENTION According to the combustion apparatus which concerns on this invention, a flame rod can be arrange | positioned near a flame hole surface compared with the conventional combustion apparatus. For this reason, the flame rod of the combustion device according to the present invention has higher detection performance than the frame rod of the conventional combustion device.

  In the above-described combustion device, the core wire includes a first portion having a tip end portion and arranged along the flame hole surface. The tip portion is arranged on the side opposite to the chamber with respect to the flame hole surface, and is arranged so as to overlap the burner in plan view. As a result, the flame rod of the combustion device detects a phenomenon in which the flame lifts due to a decrease in the oxygen concentration in the supply air in order to prevent incomplete combustion, as compared with the frame rod of the conventional combustion device. Performance (hereinafter, low oxygen detection performance) is improved.

  In the above combustion device, the core wire connects the second portion inserted into the chamber, the third portion disposed between the first portion and the second portion, and the first portion and the third portion. A first bent portion, and a second bent portion connecting the second portion and the third portion. Thereby, the position of the first portion is less likely to be restricted by the inclination angle of the core wire with respect to the mounting surface, as compared with the case where the core wire has only one bent portion between the first portion and the second portion. . Therefore, in the frame rod, the first portion is arranged along the flame hole surface regardless of the inclination angle, so that the low oxygen detection performance can be easily enhanced.

  The combustion device further includes a burner flange portion disposed between the burner and the core wire such that at least a part thereof overlaps an outer edge portion of the burner in a plan view. In the above-described combustion device, the burner flange portion is disposed between the flame hole surface and the core wire when the frame rod inserted into the chamber is disposed at a position different from a predetermined mounting position, and at a different position. It is provided so as to prevent the arranged core wire from contacting the flame hole surface. The burner flange portion can prevent damage to the flame hole surface due to the core wire contacting the flame hole surface when the frame rod including the core wire bent as described above is attached to the chamber.

  In the above combustion device, the structure of the burner is fibrous. The structure of the burner flange portion is a plate-like structure made of a metal material, and is a structure that is less likely to be damaged when contacted with a frame rod as compared with a burner. Such a burner flange can prevent the frame rod from damaging the burner together with the burner flange when the frame rod contacts the burner flange.

  In the above combustion device, the outer peripheral portion is provided with a through hole through which a frame rod is inserted, and a concave portion connected to an end of the through hole on the burner side. The width of the recess in the first direction extending to the outer peripheral side of the burner is smaller than the width of the recess in the second direction orthogonal to the first direction. Such a recess can prevent the frame rod from interfering with the chamber when the frame rod including the core wire bent as described above is attached to the chamber.

  In the above combustion device, the frame rod further includes an insulator covering a part of the core wire. The combustion device further includes a fixing portion for fixing the frame rod to the chamber. The fixing portion has an insertion hole through which the insulator is inserted. The insertion hole is provided so as to position the inserted frame rod with respect to the fixed portion. The fixing portion has an engaging portion that engages with the chamber. The engagement portion is provided so as to position the fixing portion with respect to the chamber. This prevents the combustion device from attaching the frame rod to a position different from the predetermined position with respect to the chamber.

  A hot water device according to the present invention includes the above-described combustion device, and a heat exchange unit that heats hot and cold water with combustion gas generated by burning the mixed gas in the combustion device. For this reason, it is possible to provide a hot water device provided with a combustion device whose frame rod has high detection performance.

  According to the present invention, it is possible to provide a combustion device and a hot water device in which a frame rod has high detection performance.

It is a figure which shows the structure of the water heater in embodiment typically. FIG. 2 is a perspective view illustrating a configuration example of a combustion device and a sensible heat recovery heat exchanger illustrated in FIG. 1. FIG. 3 is a partial cross-sectional view as viewed from an arrow III-III in FIG. 2. FIG. 3 is a partial plan view showing a configuration of a mounting portion and a fixing portion of the combustion device shown in FIG. 2. FIG. 3 is a partial perspective view illustrating a configuration of a mounting portion and a fixing portion of the combustion device illustrated in FIG. 2. FIG. 3 is a partial cross-sectional view illustrating a configuration of a concave portion of the combustion device illustrated in FIG. 2. FIG. 3 is a partial cross-sectional view showing a state where a frame rod of the combustion device shown in FIG. 2 is attached to a chamber. FIG. 8 is a partial cross-sectional view of the combustion device shown in FIG. 7 taken along a hole axis direction of a through hole and a direction perpendicular to the paper surface of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, a plan view means a viewpoint viewed from a direction orthogonal to a mounting surface 31i to which the burner 30 is mounted in the chamber 31. First, the configuration of a water heater according to an embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the water heater 100 of the present embodiment includes a sensible heat recovery heat exchanger (primary heat exchanger) 10, a latent heat recovery heat exchanger (secondary heat exchanger) 20, and a burner 30. , A chamber 31, a fan (blower) 32, a duct 33, a venturi 34, an orifice 35, a gas valve 36, a pipe 40, a bypass pipe 41, and a housing 50. . Inside the housing 50, all of the above components except the housing 50 are arranged.

  The gas valve 36, the orifice 35 and the venturi 34 are connected to the pipe in this order. Fuel gas can be supplied to this pipe from outside the housing 50. The fuel gas supplied to the pipe flows through the gas valve 36 and the orifice 35 to the venturi 34.

  The gas valve 36 is for switching between supply and stop of fuel gas and for equalizing the gas pressure at the inlet of the venturi 34 with the air pressure. The venturi 34 increases the negative pressure of the fuel gas inlet by increasing the flow velocity of the air, thereby promoting the flow of the fuel gas. The venturi 34 is configured to take in air from outside the housing 50. The venturi 34 is configured to mix the air introduced from outside the housing 50 with the fuel gas supplied from the pipe.

  The venturi 34 is connected to the fan 32 through a pipe. With this pipe, the mixed gas mixed in the venturi 34 is sent to the fan 32. The fan 32 is for supplying the mixed gas to the burner 30. The fan 32 mainly has a fan case, an impeller arranged in the fan case, and a driving source (such as a motor) for rotating the impeller.

  The fan 32 is connected to the chamber 31, and the chamber 31 is connected to the burner 30. The mixed gas supplied from the fan 32 is sent to the burner 30 through the chamber 31.

  The burner 30 is for generating a combustion gas as a heating gas by burning the mixed gas. The burner 30 is a reverse combustion type device that supplies combustion gas downward. The mixed gas blown from the burner 30 is ignited by the ignition plug 14 and becomes a combustion gas. The ignition plug 14 is arranged downstream of the burner 30 in the flow direction of the mixed gas, and is attached to, for example, the sensible heat recovery heat exchanger 10. The presence or absence of a flame generated in the burner 30 by the combustion of the mixed gas is detected by the frame rod 15. The frame rod 15 is arranged downstream of the burner 30 in the flow direction of the mixed gas, and is attached to the chamber 31. Details of the frame rod 15 will be described later.

  The burner 30, the sensible heat recovery heat exchanger 10, and the latent heat recovery heat exchanger 20 are connected so that the combustion gas passes through the sensible heat recovery heat exchanger 10 and the latent heat recovery heat exchanger 20 in order. Specifically, the sensible heat recovery heat exchanger 10 is mounted below the burner 30, and the latent heat recovery heat exchanger 20 is mounted below this sensible heat recovery heat exchanger 10.

  A duct 33 is connected to the latent heat recovery heat exchanger 20, and the duct 33 extends outside the housing 50. As a result, the combustion gas that has passed through the latent heat recovery heat exchanger 20 is discharged to the outside of the housing 50 through the duct 33.

  Each of the sensible heat recovery heat exchanger 10 and the latent heat recovery heat exchanger 20 heats hot and cold water by performing heat exchange between the combustion gas supplied from the burner 30 and hot and cold water.

  The sensible heat recovery heat exchanger 10 is for recovering the sensible heat of the combustion gas generated by the burner 30. The sensible heat recovery heat exchanger 10 mainly has a case 11 and a heat absorbing pipe 13 (FIGS. 3 and 4). The latent heat recovery heat exchanger 20 is for recovering the latent heat of the combustion gas. As the latent heat recovery heat exchanger 20, for example, a plate heat exchanger is used.

  When the temperature of hot water entering the sensible heat recovery heat exchanger 10 is low, or when the amount of heating of the burner 30 is small, the steam of the combustion gas is condensed in the sensible heat recovery heat exchanger 10 (Drain) occurs. Drain is also generated in the latent heat recovery heat exchanger 20. These drains are drained to the outside of the housing 50 through a part of the duct 33.

  The heat absorption pipe 13 of the sensible heat recovery heat exchanger 10 and the heat transfer section of the latent heat recovery heat exchanger 20 are connected by a pipe 40. A portion of the pipe 40 on the water inlet side of the latent heat recovery heat exchanger 20 and a portion of the pipe 40 on the tap side of the sensible heat recovery heat exchanger 10 are bypassed by a bypass pipe 41.

  A bypass servo 42 is connected to the bypass pipe 41. The bypass servo 42 is configured to control the flow rate of water flowing through the bypass pipe 41.

  The water supplied to the above-described hot water device 100 exchanges heat with the combustion gas in the sensible heat recovery heat exchanger 10 and the latent heat recovery heat exchanger 20 to become hot water. Thereby, hot water can be supplied by the hot water device 100.

  Next, the configuration of the combustion device 200 used in the above-described hot water device 100 will be described with reference to FIGS. FIGS. 7 and 8 are partial cross-sectional views showing an intermediate state when the frame rod 15 is attached to the flange portion 31a, but the frame rod 15 is not viewed in cross section. FIG. 7 is a cross section passing through the hole axis of the through hole 31c and perpendicular to the extending direction of the flange portion 31a. FIG. 8 is a cross-sectional view of the burner flange 37 side from a cross-section that passes through the hole axis of the through-hole 31c and is perpendicular to the plane of FIG.

  As shown in FIGS. 1 to 3, the combustion device 200 includes a burner 30, a chamber 31, a burner flange portion 37, a spark plug 14, a frame rod 15, a holding member 16 as a fixing portion, and a fixing member. 17 and a seal member 18.

  As shown in FIG. 3, the burner 30 has a flame hole surface 30b in which a plurality of flame holes 30a are open. The burner 30 burns the mixed gas supplied on the flame hole surface 30b through the plurality of flame holes 30a to generate a flame. The burner hole surface 30b is a curved surface having a center of curvature disposed above the burner 30, for example. The plurality of flame holes 30 a are provided, for example, inside the outer edge of the burner 30 in plan view, and are not provided on the outer edge of the burner 30. Each hole axis of the plurality of flame holes 30a is provided to be orthogonal to the flame hole surface 30b. The burner 30 is connected to an exhaust port of the chamber 31. The burner 30 is arranged so as to overlap the entire exhaust port 31h of the chamber 31 in a plan view, for example. The structure of the burner 30 is fibrous. Here, the fibrous structure means a structure formed by weaving fibers.

  As shown in FIG. 3, the chamber 31 supplies the mixed gas supplied from the fan 32 to the plurality of flame holes 30 a of the burner 30. The chamber 31 has an inlet connected to the fan 32 and an outlet 31 h connected to the burner 30. The chamber 31 includes a flange portion 31a (outer peripheral portion) disposed outside the burner 30 and the exhaust port 31h in a plan view. The flange portion 31a is annularly arranged so as to surround the burner 30 and the outer periphery of the exhaust port 31h in plan view.

  As shown in FIG. 2 to FIG. 4, the flange portion 31 a includes an outer peripheral region connected to an upper end portion of the sensible heat recovery heat exchanger 10 via a seal member 38, a burner flange portion 37, and a seal member 39. An inner peripheral region connected through the inner peripheral region and an attaching portion 31b to which the frame rod 15 is attached are disposed between the outer peripheral region and the inner peripheral region. The lower surface of the inner peripheral region of the flange portion 31a is a mounting surface 31i to which the burner 30 is mounted via the burner flange portion 37.

  As shown in FIG. 3, the mounting portion 31b is provided with a through hole 31c penetrating between the upper surface and the lower surface of the mounting portion 31b. The hole axis of the through hole 31c is inclined with respect to the mounting surface 31i. The upper surface of the attachment portion 31b is an inclined surface 31d that is inclined with respect to the upper surface of another portion of the flange portion 31a other than the attachment portion 31b. The inclined surface 31d is inclined so as to go upward as it goes inward in plan view. The one end of the through hole 31c is open to the inclined surface 31d.

  As shown in FIGS. 4 and 5, the attachment portion 31b extends in a direction intersecting with the inclined surface 31d, and further includes a first side surface 31f and a second side surface 31g arranged with the inclined surface 31d interposed therebetween. Have. The first side surface 31f and the second side surface 31g are inclined with respect to the upper surface of another portion of the flange portion 31a other than the attachment portion 31b. The distance W1 between the through hole 31c and the first side surface 31f is shorter than the distance W2 between the through hole 31c and the second side surface 31g.

  The lower surface of the mounting portion 31b faces the inside of the case 11, and is configured as an inner peripheral surface of a concave portion 31e that is recessed with respect to the lower surface of the other portion of the flange portion 31a other than the mounting portion 31b. The details of the recess 31e will be described later.

  As shown in FIG. 3, the hole axis of the through hole 31c is inclined with respect to the upper surface of the flange portion 31a. One end of the through hole 31 c faces the outside of the chamber 31 and the case 11. The other end of the through hole 31c faces the inside of the case 11 of the sensible heat recovery heat exchanger 10. The other end of the through hole 31c is disposed inside and below the one end of the through hole 31c in a plan view. The opening shape of the through hole 31c may be any shape, for example, a circular shape.

  The burner flange portion 37 is annularly arranged so as to surround the plurality of flame holes 30a in plan view. As shown in FIG. 3, the burner flange portion 37 is arranged so as to surround the outer edge portion of the burner 30 in a plan view and the inner peripheral portion 37 a arranged so as to overlap the outer edge portion of the burner 30. And an outer peripheral portion 37b arranged. The inner peripheral portion 37a of the burner flange 37 is disposed on the tip end 15T side of the frame rod 15 with respect to the flame hole surface 30b, that is, on the sensible heat recovery heat exchanger 10 side. The outer peripheral portion 37b of the burner flange portion 37 is attached to the flange portion 31a. Thus, the burner flange portion 37 supports the burner 30 with respect to the chamber 31.

  The structure of the burner flange 37 is a plate made of a metal material, and is less likely to be damaged when it is brought into contact with the frame rod, as compared with the burner 30 having a fibrous structure.

  As shown in FIG. 2, the spark plug 14 has a pair of spark plug electrodes. The spark plug 14 generates a flame in the mixed gas ejected from the burner 30 by generating an ignition spark between a pair of spark plug electrodes.

  As shown in FIGS. 2 and 3, the spark plug 14 is attached to a wall surface of the case 11. The spark plug 14 is attached to the case 11 through the case 11. The ignition plug 14 is disposed between the heat absorbing pipe 13 closest to the burner 30 among the plurality of heat absorbing pipes 13 arranged adjacent to the case 11, that is, the heat absorbing pipe 13 positioned at the highest position, The heat absorbing pipe 13 is disposed between the heat absorbing pipe 13 and the heat absorbing pipe 13 located second from the top.

  The spark plug 14 includes a core wire made of a conductive material and an insulator made of an electrically insulating material and covering a part of the core wire. The core wire of the spark plug 14 has a tip portion 14 </ b> T located inside the case 11. The core wire of the spark plug 14 is bent at one place inside the case 11. The core wire of the ignition plug 14 has, for example, a portion extending along the horizontal direction, a portion extending toward the burner 30 side with respect to the portion, and a bent portion connecting the two portions. are doing. The portion extending along the horizontal direction of the core wire of the ignition plug 14 is attached to the case 11 via an insulator. The portion of the core wire of the spark plug 14 extending toward the burner 30 has the above-mentioned tip portion 14T.

  The flame rod 15 applies an AC voltage during the flame generated by the burner 30 and uses at least one of conductivity and rectification by ionization of the combustion gas in the flame to cause a direct current flowing from the flame rod 15 to the flame. The presence or absence of a flame is detected by detecting the current.

  As shown in FIGS. 2 and 3, the frame rod 15 is attached to the flange 31 a of the chamber 31. The frame rod 15 is disposed on the side of the chamber 31 with respect to the flame hole surface 30b, and the one end 15S disposed outside the burner 30 in a plan view, and is opposite to the chamber 31 with respect to the flame hole surface 30b. And a tip portion 15T disposed on the side and overlapping the burner 30 in plan view. The tip portion 15T is arranged at a distance from the flame hole surface 30b in a direction perpendicular to the flame hole surface 30b. Preferably, the combustion device 200 further includes a frame rod 19 attached to the case 11 in addition to the frame rod 15. With the two frame rods 15 and 19 having different distances from the flame hole surface 30b, the low oxygen detection performance is enhanced as compared with the case where only one of them is used. The frame rod 19 may have the same configuration as the frame rod of the above-described conventional combustion device.

  The frame rod 15 includes a core 15a made of a conductive material and having the one end 15S and the tip 15T, and an insulator 15b made of an electrically insulating material and covering a part of the core 15a. The core wire 15 a of the frame rod 15 is bent at at least two places inside the case 11. The bending point of the core wire 15 a of the frame rod 15 is larger than the bending point of the core wire of the ignition plug 14.

  The core wire 15a includes a first portion 15aa having a tip 15T, a second portion 15ab having one end 15S, a third portion 15ac, a first bent portion 15ad, and a second bent portion 15ae. A part of the second portion 15ab of the core wire 15a is covered with the insulator 15b. Of the core wire 15a, the first portion 15aa, the third portion 15ac, the first bent portion 15ad, and the second bent portion 15ae are not covered with the insulator 15b and are exposed inside the case 11.

  The first portion 15aa is arranged along the flame hole surface 30b. That is, the distance between the first portion 15aa and the flame hole surface 30b is substantially constant.

  Part of the second portion 15ab is disposed outside the chamber 31 and the case 11. The other part of the second portion 15ab is arranged inside the case 11. The remaining portion of the second portion 15ab is inserted into the through hole 31c of the flange 31a.

  The third portion 15ac is arranged between the first portion 15aa and the second portion 15ab. The first bent portion 15ad connects the first portion 15aa and the third portion 15ac.

  The first bent portion 15ad is disposed so as not to overlap with the flame hole surface 30b but to overlap with the burner flange portion 37 when viewed from a direction perpendicular to the flame hole surface 30b. From a different point of view, the first bent portion 15ad is located outside the space between the projection surface obtained by projecting the flame hole surface 30b in a direction perpendicular to the flame hole surface 30b and the flame hole surface 30b. , Is located. The first angle formed by the first portion 15aa and the third portion 15ac in the first bent portion 15ad is, for example, an obtuse angle.

  The second bent portion 15ae connects the second portion 15ab and the third portion 15ac. The second angle formed by the second portion 15ab and the third portion 15ac in the second bent portion 15ae is, for example, an obtuse angle. The first angle is larger than, for example, the second angle. The first angle is larger than, for example, the bending angle of the core wire of the ignition plug 14. The second angle is smaller than, for example, the bending angle of the core wire of the ignition plug 14.

  As shown in FIG. 3, the insulator 15b has a main body 15ba and an overhang 15bb. The main body 15ba holds the second portion 15ab of the core wire 15a. The main body 15ba has one end located on one end 15S side of the core wire 15a and arranged outside the chamber 31 and the case 11, and the other end located on the tip end 15T side of the core wire 15a and arranged inside the case 11. Have. The projecting portion 15bb projects outward from an outer peripheral surface of a portion located between one end and the other end of the main body portion 15ba. The portion of the main body 15ba located on one side from the overhang 15bb and the overhang 15bb are arranged outside the chamber 31 and the case 11. A part of the main body part 15ba located on the other end side of the overhang part 15bb is partially inserted into the through hole 31c, and the remaining part is disposed inside the case 11. The portion of the main body 15ba located on the other end side of the overhang 15bb is rotatable about the core 15a in the through hole 31c. That is, when a portion of the main body 15ba located on the other end side of the overhang portion 15bb rotates around the core wire 15a in the through hole 31c, the portion is provided so as not to interfere with the through hole 31c. . The planar shape of the portion of the main body portion 15ba located on the other end side of the overhang portion 15bb is symmetric with respect to the center of the core wire 15a, and is, for example, a circular shape.

  As shown in FIG. 4, the planar shape of a portion of the main body 15ba located on one end side of the overhang portion 15bb, that is, a portion that is not inserted into the through hole 31c is asymmetric with respect to the center of the core wire 15a. .

  The fixing portion is provided to restrict the movement of the frame rod 15 with respect to the flange portion 31a. The fixing portion moves the frame rod 15 from the state in which the frame rod 15 is disposed at a predetermined position (first position) with respect to the flange portion 31a (hereinafter, a first state) with respect to the flange portion 31a. It is provided so as to restrict movement in the hole axis direction of the through hole 31c. Further, the fixing portion is provided to restrict the frame rod 15 from rotating in the circumferential direction about the hole axis of the through hole 31c with respect to the flange portion 31a from the first state. Note that the predetermined position is the position of the frame rod 15 shown in FIG. 4, the first portion 15aa is arranged along the flame hole surface 30b, and the frame rod 15 has the predetermined detection performance ( Flame detection performance and low oxygen detection performance).

  The fixing portion has a holding member 16 and a fixing member 17. In the first state, the pressing member 16 presses the projecting portion 15bb and the seal member 18 from the side opposite to the mounting portion 31b.

  The pressing member 16 has an opposing portion 16a, a pair of contact portions 16b, and at least one protruding portion 16d (engaging portion). The facing portion 16a faces the inclined surface 31d in the first state, and is provided so as to sandwich the projecting portion 15bb and the seal member 18 with the inclined surface 31d. The opposing portion 16a is provided with a second through hole 16c through which a portion of the body 15ba of the insulator 15b located on the one end side with respect to the overhang portion 15bb is inserted. The planar shape of the second through hole 16c is asymmetric with respect to the center of the second through hole 16c. The opposing portion 16a is further provided with a plurality of third insertion holes into which the fixing member 17 is inserted. The plurality of third through holes are provided so as to sandwich the second through hole 16c.

  Each contact portion 16b is bent with respect to the facing portion 16a. Each contact portion 16b is provided so as to contact the inclined surface 31d in the first state. Each contact portion 16b is connected to, for example, both ends of an opposing portion 16a opposing the second through hole. When the planar shape of the facing portion 16a has a longitudinal direction and a transverse direction, the pair of contact portions 16b is preferably connected to both ends of the facing portion 16a in the transverse direction.

  The widths of the pair of contact portions 16b in the hole axis direction of the second through holes 16c are equal. The width of each contact portion 16b in the hole axis direction of the second through hole 16c is smaller than the sum of the width of the projecting portion 15bb in the extending direction of the core wire 15a and the thickness of the seal member 18 in a non-pressed state. The width of each contact portion 16b in the hole axis direction of the second through hole 16c is designed as a value obtained by subtracting a predetermined allowance for crushing of the seal member 18 from the above sum. Accordingly, for example, when the fixing member 17 is a screw and the torque acting on the seal member 18 when tightening the screw varies, the seal member 18 located on one side with respect to the second through hole 16c is formed. The variation between the crushing allowance and the crushing allowance of the seal member 18 located on the other side can be suppressed.

  As shown in FIGS. 4 and 5, the protruding portion 16d is connected to the facing portion 16a. The protruding portion 16d protrudes from the contact portion 16b on the side opposite to the facing portion 16a. When the planar shape of the facing portion 16a has a longitudinal direction and a lateral direction, the protruding portion 16d is connected to only one end of the facing portion 16a in the longitudinal direction.

  As shown in FIG. 4, the distance between the surface of the protrusion 16d facing the second through hole 16c and the second through hole 16c is the distance W1 between the first insertion hole and the first side surface 31f. be equivalent to. Thus, in the state at the first position, the protruding portion 16d comes into contact with the first side surface 31f, the opposing portion 16a is held parallel to the inclined surface 31d, and the frame rod 15 is attached to the flange portion 31a. It is properly attached to. On the other hand, in a state where the first position is rotated by 180 degrees with respect to the center of the second through hole 16c, the protruding portion 16d contacts the inclined surface 31d, and the facing portion 16a is inclined with respect to the inclined surface 31d. The frame rod 15 cannot be inserted into the through-hole 31c because it interferes with the through-hole 31c.

  The fixing member 17 may be a screw member such as a screw, a screw, a bolt, or the like, or may be a pin or the like. The seal member 18 is, for example, a rubber packing. In the pressed state, the seal member 18 is pressed in the thickness direction, and seals the through hole 31c.

  As shown in FIGS. 7 and 8, the concave portion 31e is provided so as not to interfere with the frame rod 15 rotated with respect to the flange portion 31a when attaching the frame rod 15 to the flange portion 31a. I have.

  As shown in FIGS. 3, 7, and 8, the concave portion 31e has a bottom surface facing downward and side surfaces surrounding the bottom surface. The bottom surface of the recess 31e is recessed with respect to the lower surface of the outer peripheral region and the lower surface of the inner peripheral region of the flange portion 31a. The side surface of the concave portion 31e connects between the bottom surface of the concave portion 31e and the lower surface of the outer peripheral region and the lower surface of the inner peripheral region of the flange portion 31a. The through-hole 31c is opened on the bottom surface of the concave portion 31e and on the side surface connecting the bottom surface of the concave portion 31e and the lower surface of the outer peripheral region of the flange portion 31a. As shown in FIG. 8, the through-hole 31c is arranged closer to one side than the center of the concave portion 31e in the extending direction of the flange portion 31a, for example.

  As shown in FIG. 6, the width W3 of the concave portion 31e in the extending direction of the flange portion 31a is wider than the width W4 of the concave portion 31e in the direction perpendicular to the extending direction of the flange portion 31a in plan view. From a different point of view, the width W4 of the recess in the first direction extending from the center of the burner 30 toward the outer periphery in plan view is smaller than the width W3 of the recess in the second direction orthogonal to the first direction in plan view. .

  The frame rod 15 is attached to the flange portion 31a, for example, as follows.

  First, the frame rod 15 and the pressing member 16 positioned with respect to each other are prepared. Specifically, the frame rod 15 is positioned with respect to the holding member 16 by inserting the insulator 15b into the second through hole 16c of the holding member 16. Further, the seal member 18 is disposed so as to surround the second through hole 16c.

  Next, a portion of the core wire 15a of the frame rod 15 located closer to the distal end portion 15T than the insulator 15b is inserted into the through hole 31c. Subsequently, the insulator 15b is inserted into the through hole 31c. At this time, as shown in FIG. 7, the insulator 15b is arranged so that the central axis thereof is along the hole axis of the through hole 31c. Furthermore, each part of the core wire 15a of the frame rod 15 is disposed so as to overlap the hole axis of the through hole 31c when viewed from the extending direction of the flange portion 31a. At this time, interference between the first portion 15aa and the flange portion 31a is prevented by providing the recess portion 31e in the flange portion 31a. A part of the first portion 15aa is disposed in the concave portion 31e, and the remaining portion of the first portion 15aa including the tip portion 15T is disposed inside the case 11 outside the concave portion 31e. At this time, the pressing member 16 is disposed at a position where it cannot be engaged with the mounting portion 31b.

  Thereafter, when the frame rod 15 moves along the hole axis of the through hole 31c, the portion of the core wire 15a located closer to the distal end portion 15T than the insulator 15b also moves along the hole axis. After the overhang portion 15bb contacts the inclined surface 31d, the frame rod 15 is rotated relatively to the flange portion 31a. The frame rod 15 is rotated, for example, 90 degrees with respect to the flange portion 31a. In this way, the pressing member 16 is disposed at a position that can be fixed to the mounting portion 31b. Further, when the holding member 16 is arranged at a position where it can be fixed to the mounting portion 31b, the frame rod 15 positioned with respect to the holding member 16 moves with respect to the flange portion 31a as shown in FIG. At a predetermined position. At this time, the facing portion 16a sandwiches the protruding portion 15bb and the seal member 18 between the inclined surface 31d, the contact portion 16b contacts the inclined surface 31d, and the protruding portion 16d contacts the mounting portion 31b and the first side surface 31f. I do. Next, the fixing member 17 is inserted into the third insertion hole of the pressing member 16 disposed at the above position, and is fixed to the flange portion 31a. Thereby, the frame rod 15 is fixed to the flange portion 31a.

  When the frame rod 15 is rotated relatively to the flange portion 31a before the overhang portion 15bb comes into contact with the inclined surface 31d, for example, the first portion 15aa and the core portion 15a such as the first bent portion 15ad are rotated. A part may contact the burner flange 37. Since the burner flange portion 37 is provided so as not to be damaged even when pressed by the core wire 15a, contact between the core wire 15a of the frame rod 15 and the burner 30 is prevented by the burner flange portion 37.

Next, the operation and effect of the present embodiment will be described in comparison with a conventional combustion device.
As described above, in the conventional combustion device, the frame rod is attached to the side wall of the case of the heat exchanger. The mounting position of the frame rod on the side wall of the case of the heat exchanger is restricted by other components of the heat exchanger such as piping through which hot and cold water flows. Due to this restriction, in the above-described water heater, the frame rod is disposed relatively far from the flame hole surface of the burner.

  On the other hand, according to the present embodiment, the frame rod 15 is attached to the flange portion 31a of the chamber 31 that is disposed closer to the burner 30 than the case 11 is. Further, in the core wire 15a of the frame rod 15, the second portion 15ab inserted into the through hole 31c of the chamber 31 is inclined with respect to the mounting surface 31i, and the first portion 15aa is positioned with respect to the second portion 15ab. It is bent toward the flame hole surface 30b. Therefore, according to the combustion device 200, the first portion 15aa of the frame rod 15 can be arranged closer to the flame hole surface 30b as compared with the conventional combustion device. For this reason, the frame rod 15 has higher detection performance than the frame rod of the conventional combustion device.

  In the combustion device 200, when the second portion 15ab is configured to extend perpendicularly to the mounting surface 31i and penetrate the flange portion 31a, the frame rod 15 may interfere with the heat absorbing pipe 13 or the burner 30. Become. In this case, in order to prevent the interference between the frame rod 15 and the heat absorbing pipe 13 or the burner 30, for example, it is necessary to increase the distance between the heat absorbing pipe 13 and the burner 30. cause. According to the above-described combustion device 200, the frame rod 15 can be arranged near the flame hole surface 30b without increasing the size of the device.

  In the combustion device 200, the core wire 15a includes a first portion 15aa having a tip portion 15T and arranged along the flame hole surface 30b. The tip portion 15T is arranged on the side opposite to the chamber 31 with respect to the flame hole surface 30b, and is arranged so as to overlap the burner 30 in plan view.

  Accordingly, the first portion 15aa of the frame rod 15 is disposed near the flame hole surface 30b, and the distance from the flame hole surface 30b is substantially constant. For this reason, the low oxygen detection performance of the frame rod 15 is enhanced as compared with the frame rod of the conventional combustion device that does not include the first portion 15aa.

  In the above-described combustion device, the core wire 15a includes the second portion 15ab inserted into the chamber 31, the third portion 15ac disposed between the first portion 15aa and the second portion 15ab, and the first portion 15aa. It has a first bent portion 15ad connecting the third portion 15ac, and a second bent portion 15ae connecting the second portion 15ab and the third portion 15ac. Thereby, the position of the first portion 15aa is smaller than the case where the core wire 15a has only one bent portion between the first portion 15aa and the second portion 15ab, and the inclination angle of the core wire 15a with respect to the mounting surface 31i. Is less likely to be restricted by That is, in the frame rod 15, the first portion 15aa is arranged along the flame hole surface regardless of the inclination angle. Therefore, the design of the frame rod 15 is easy, and the low oxygen detection performance is enhanced.

  In order to arrange the frame rod near the flame hole surface in the conventional combustion device, the frame rod is bent at an angle close to a right angle with respect to a portion of the frame rod attached to the case side wall, and the end of the frame rod is bent. May be placed near the flame surface. However, in this case, due to the restriction on assembly accuracy, the closer the distance between the end of the frame rod and the flame hole surface is, the more the end of the frame rod is attached to the side wall of the case of the heat exchanger. There is a problem that the surface becomes easy to contact, and as a result, the flame hole surface is easily damaged.

  On the other hand, the combustion device 200 further includes a burner flange portion 37 disposed between the burner 30 and the core wire 15a so that at least a part thereof overlaps the outer edge of the burner 30 in plan view. In the combustion device 200, when the frame rod 15 inserted into the chamber 31 is disposed at a position different from a predetermined mounting position, the burner flange portion 37 is located between the flame hole surface 30b and the core wire 15a. The core wires 15a are arranged so as to prevent the core wires 15a arranged at the different positions from coming into contact with the flame hole surface 30b. The burner flange 37 prevents damage to the flame hole surface 30b due to the core wire 15a coming into contact with the flame hole surface 30b when the frame rod 15 including the core wire 15a bent as described above is attached to the chamber 31. Can be prevented.

  In the combustion device 200, the structure of the burner 30 is fibrous. The structure of the burner flange portion 37 is a plate made of a metal material, and is a structure that is less likely to be damaged when contacted with a frame rod as compared with the burner 30. Such a burner flange portion 37 can prevent the frame rod 15 from damaging the burner 30 together with the burner flange portion 37 when the frame rod 15 contacts the burner flange portion 37.

  In the combustion device 200, the flange portion 31a is provided with a through hole into which a frame rod is inserted, and a concave portion connected to an end of the through hole on the burner side. The width of the recess in the first direction extending to the outer peripheral side of the burner is smaller than the width of the recess in the second direction orthogonal to the first direction. Such a recess can prevent the frame rod from interfering with the chamber when the frame rod including the core wire bent as described above is attached to the chamber.

  In the above combustion device, the frame rod further includes an insulator covering a part of the core wire. The combustion device further includes a fixing portion for fixing the frame rod to the chamber. The fixing portion has an insertion hole through which the insulator is inserted. The insertion hole is provided so as to position the inserted frame rod with respect to the fixed portion. The fixing portion has an engaging portion that engages with the chamber. The engagement portion is provided so as to position the fixing portion with respect to the chamber. This prevents the combustion device from attaching the frame rod to the chamber at a position different from the predetermined position.

  A hot water device according to the present invention includes the above-described combustion device, and a heat exchange unit that heats hot and cold water with combustion gas generated by burning the mixed gas in the combustion device. For this reason, it is possible to provide a hot water device provided with a combustion device whose frame rod has high detection performance.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Reference Signs List 10 sensible heat recovery heat exchanger, 11 case, 13 heat absorbing pipe, 14 spark plug, 14T, 15T tip, 15 frame rod, 15S one end, 15a core wire, 15aa first part, 15ab second part, 15ad first bent part , 15ae second bent portion, 15b insulator, 15ba body portion, 15bb overhanging portion, 16 pressing member, 16a facing portion, 16b contact portion, 16c second through hole, 16d projecting portion, 17 fixing member, 18, 38, 39 seal Member, 20 latent heat recovery heat exchanger, 30 burner, 30a flame hole, 30b flame surface, 31 chamber, 31a flange portion, 31b mounting portion, 31c through hole, 31d inclined surface, 31e concave portion, 31f first side surface, 31g 2 sides, 31h exhaust port, 31i mounting surface, 32 fan, 33 duct, 34 bench Li, 35 orifices, 36 gas valve, 37 a burner flange portion, 37a inner peripheral portion, 37b outer peripheral portion, 40 pipe, 41 bypass piping, 42 bypass servo, 44 hot water pipe, 50 casing, 100 water heater, 200 a combustion device.

Claims (9)

A burner having a flame surface in which a plurality of flame holes are open;
A chamber having a mounting surface to which the burner is mounted, and supplying a mixed gas to the plurality of flame holes;
A frame rod attached to the outer peripheral portion of the chamber located on the outer peripheral side of the burner in plan view, and including a core wire;
The combustion device, wherein the core wire extends obliquely with respect to the mounting surface, penetrates the chamber, and is bent toward the flame hole surface. The core wire has a tip portion and includes a first portion arranged along the flame hole surface,
2. The combustion device according to claim 1, wherein the tip portion is arranged on a side opposite to the chamber with respect to the flame hole surface, and is arranged so as to overlap the burner in a plan view. 3. The core wire is
A second portion inserted through the chamber;
A third portion disposed between the first portion and the second portion;
A first bent portion connecting the first portion and the third portion,
The combustion device according to claim 2, further comprising a second bent portion connecting the second portion and the third portion.   The combustion according to any one of claims 1 to 3, further comprising a burner flange portion disposed between the burner and the core wire so that at least a part thereof overlaps an outer edge portion of the burner in a plan view. apparatus.   The burner flange portion is disposed between the flame hole surface and the core wire when the frame rod inserted into the chamber is disposed at a position different from a predetermined mounting position, and the different position. The combustion device according to claim 4, wherein the combustion device is provided so as to prevent the core wire arranged in the contact hole from coming into contact with the flame hole surface. The structure of the burner is fibrous,
The combustion device according to claim 4, wherein the structure of the burner flange portion is a plate made of a metal material, and is a structure that is less likely to be damaged when contacted with the frame rod than the burner. The outer peripheral portion is provided with a through hole through which the frame rod is inserted, and a concave portion connected to an end of the through hole on the burner side,
The combustion according to any one of claims 1 to 6, wherein a width of the concave portion in a first direction extending to an outer peripheral side of the burner is smaller than a width of the concave portion in a second direction orthogonal to the first direction. apparatus. The frame rod further includes an insulator covering a part of the core wire,
Further comprising a fixing portion for fixing the frame rod to the chamber,
The fixing portion is provided with an insertion hole through which the insulator is inserted,
The insertion hole is provided to position the inserted frame rod with respect to the fixing portion,
The fixing portion has an engaging portion that engages with the chamber,
The combustion device according to claim 1, wherein the engagement portion is provided so as to position the fixing portion with respect to the chamber. The combustion device according to any one of claims 1 to 8,
A hot water device comprising: a heat exchange unit that heats hot and cold water with combustion gas generated by burning the mixed gas in the combustion device.

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