JP3053743B2 - Combustor with misfire sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to simplification of an operation for adjusting a mounting position of a misfire sensor in accordance with a change in fuel used in a combustor.

[0002]

2. Description of the Related Art As a combustor, for example, a water heater has a combustion cylinder installed upright in a housing made of a metal plate and a burner installed below the combustion cylinder. A heat exchanger is provided in the upper part of the combustion tube, and a safety device for detecting misfire and stopping the supply of fuel is attached to the burner. This safety device is provided with a misfire sensor in which a heat-sensitive portion is disposed near the burner port of the burner, and has a structure in which the output of the misfire sensor closes the safety valve.

[0003] Gas types for switching the fuel gas used in the combustor from city gas to natural gas have been gradually changed, and work to change the combustor in use from the conventional city gas specification to the natural gas specification has been carried out. Have been done. This change in gas type involves adjusting the mixing ratio of combustion air required for combustion of the fuel gas, and the degree of flame extension, etc., depending on the type of fuel gas. It is necessary to adjust the mounting position so that the output becomes equal to or less than the reference value even after changing the gas type.

[0004]

This change in specifications is performed on site for many gas appliances in a short period of time. For this reason, it is important that the adjustment operation is as simple as possible, can be performed in a short time, and that the adjustment amount is accurate and safety can be ensured. An object of the present invention is to switch the specification for each fuel used in accordance with a change in fuel gas, etc.
It is an object of the present invention to provide a combustor that can adjust a mounting position of a misfire sensor easily, quickly, and accurately.

[0005]

SUMMARY OF THE INVENTION The present invention provides a burner,
In a combustor having a misfire sensor attached so that a heat-sensitive portion is close to a flame port of the burner, holding means of the misfire sensor, and a safety device for closing a safety valve by an output of the misfire sensor, The holding means is fastened to a side surface of the burner provided with a screw hole and a plurality of engaged portions for positioning at a plurality of predetermined positions provided at predetermined intervals above and below the screw hole. A misfire sensor holder having a vertically long hole through which a screw to be screwed is inserted, and an engagement portion for positioning to engage with the engaged portion, and provided integrally with the misfire sensor holder, A sensor mounting portion that inclines and holds the misfire sensor so that the heat-sensitive portion of the misfire sensor approaches the flame port side.

According to a second aspect of the present invention, in the combustor, the sensor holding portion has an upper hand portion and a lower hand portion having a cylindrical recess for holding the misfire sensor in the inclined state, and the upper hand portion has a concave portion. And between the lower part and the lower hand part,
The holding spring is formed by bending a leaf spring into a substantially V shape and having a cylindrical portion for holding the misfire sensor. The bent side portion is fitted and fixed in the concave portion, and the misfire sensor can be fixed to the holding spring at a plurality of positions displaced by a predetermined distance in the axial direction and detachably held. In the present invention, the inclination range in which the misfire sensor is inclined and held toward the combustion flame includes a case where the misfire sensor is held horizontally.

[0007]

According to the present invention, the front wall of the housing of the combustor is removed, one screw is loosened, the misfire sensor holder is floated, the engaging portion is engaged with another engaged portion, and the screw is removed. By tightening, the vertical position of the misfire sensor can be adjusted accurately. Further, by removing the misfire sensor from the holding means and changing the fixed position, the position in the front-rear direction can be accurately adjusted. Therefore, it is possible to easily and accurately change the specification switching based on the gas type change in a short time. In the configuration of claim 2, the position adjustment of the misfire sensor in the front-rear direction is performed by:
It can be done by removing the misfire sensor by hand without using any tools and replacing it.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a water heater 100 vertically accommodates a combustion tube 1 made of a heat-resistant metal plate in a housing H made of sheet metal. A finned heat exchanger (not shown) is installed in the upper part of the combustion tube 1, and a burner B is mounted below the combustion tube 1. On the front side of the burner B, a misfire sensor 2, which is a sheathed thermocouple T having a tip (heat-sensitive portion) 22 positioned above a flame opening E of the burner B, is provided with a holding unit 3.
Therefore, it is attached at a 45 degree inclination angle with respect to the vertical to the back. An incomplete combustion detection window (hereinafter, referred to as a non-combustion detection window) 4 is provided in the middle of the combustion cylinder 1, and a heat-sensitive portion 54 faces the non-combustion detection window 4 so that an incomplete combustion sensor (hereinafter, referred to as a non-combustion sensor). And (5) a thermocouple is fastened.

As shown in FIGS. 2 to 4, the misfire sensor 2
A heat-sensitive portion 21 including a sheath type thermocouple T including a tip portion 22 having a small diameter, a tapered portion 23, and a body portion 24 having a large diameter;
And an outer cylinder 25 externally fitted to a rear portion (a lower portion in the figure).
The lower part of the outer cylinder 25 has two circumferential grooves 2 for positioning.
7, 28 are provided around at predetermined intervals.

The holding means 3 of the misfire sensor 2 includes a metal plate bracket 6 vertically fixed to the front side of the burner B.
And a misfire sensor holder 7 fastened to the bracket 6 by one screw 31. On the bracket 6,
A screw hole 61 into which the screw 31 is screwed is formed, and a misfire sensor 7 provided at a predetermined distance up and down.
A plurality of engaged portions 62 and 63 for positioning are formed. In this embodiment, the engaged portions 62 and 63 are constituted by a pair of left and right holes 64, 65 and 66 and 67.

The misfire sensor holder 7 is made of a block of metal and has a rectangular plate-like flange portion 71 and a sensor holding portion 8 for holding the misfire sensor 2 at an inclination of 45 degrees with respect to the vertical. An elongated hole 72 in the vertical direction for inserting the screw 31 is formed on the right side of the flange 71,
An engaging portion 73 that engages with the engaged portions 62 and 63 is provided on the rear surface so as to protrude rearward.

In this embodiment, the engaging portion 73 is composed of a pair of columnar projections 74 and 75 which fit into the pair of left and right holes 64, 65 and 66, 67. In addition,
The engaged portions 62 and 63 may be constituted by, for example, only one hole 65, 67 or 64, 66, and may be engaged with the engaging portion 73 including only one projection 75 or 74.

In this embodiment, the engaging portion 73 is
The engagement dimension that fits in 2, 63 is set shorter than the thread engagement dimension of the screw 31 into the screw hole 61. Therefore, even when the former is released, the latter is in the threaded state. Only by loosening the screw 31, the former engagement can be released and the engagement position can be changed.

The engaged portions 62 and 63 may be formed on the misfire sensor holder 7 side, and the engaging portion 73 may be formed on the bracket 6 side, except for a combination of a hole and a projection fitted into the hole. In addition, a desired engagement mechanism such as engagement of hook-shaped claw pieces formed on both sides can be adopted. As the engagement mechanism, it is desirable that the engagement position can be changed only by loosening the screw 31 and that the engagement can be detached with one touch.

The sensor holding portion 8 has an inclined surface 81 projecting upward from the center of the front surface of the flange portion 71 and inclined rearward at an angle of 45 degrees with respect to the vertical. An upper hand 84 and a lower hand 85 having semi-cylindrical recesses 82 and 83 are vertically provided on the inclined surface 81.
The recess 83 is formed with a ridge 86 that fits into the circumferential grooves 27 and 28 provided in the misfire sensor holder 7.
In the middle of the upper hand portion 84 and the lower hand portion 85, a recess 87 into which a tip portion of a holding spring 9 described later is fitted is provided.

Reference numeral 9 denotes a holding spring for detachably fixing the misfire sensor 2 to the sensor holding portion 8. The holding spring 9 is formed by forming a band-shaped spring material into a substantially V-shape and expanding to the bent portion 91. A cylindrical portion 93, 93 is provided between the opening 92 and the cylindrical portion 93.
Are provided facing each other. When the bent portion 91 is inserted into the concave portion 87, the holding spring 9 causes the step 94 formed at the boundary between the bent portion 91 and the cylindrical portions 93, 93 to be caught by the left and right edges of the concave portion 87, and to come off. Stopped and fixed.

The misfire sensor 2 is fitted with the opening 92 widened against the elastic force so as to be sandwiched between the cylindrical portions 93, 93. Before the specification change due to the change of the gas type, the misfire sensor 2 is fixed in the axial direction by fitting one of the two circumferential grooves 27 and 28 for positioning into the protruding ridge 86. The holder 7 is fixed in the vertical direction with the engaging portion 73 fitted into one of the engaged portions 62 and 63.

The specification switching operation by changing the gas type is performed in the following order. 1) Removing the front wall of housing H of water heater 100 in FIG.
State. 2) Loosen the screw 31 with a screwdriver to lift the misfire sensor holder 7, and re-engage the engaging portion 73 with the engaged portions 62 to 63 (or 63 to 62). At this time, it is not necessary to remove the screw 31 by using the screw 31 whose screwing dimension into the screw hole 61 is set longer than the projecting dimension of the engaging portion 73.

3) Retighten the screw 31. 4) Next, the misfire sensor 2 is manually pulled out of the holding spring 9 of the sensor holding unit 8 including the holding spring 9. 5) Position the misfire sensor 2 in two circumferential grooves 2 for positioning.
One of the members 7 and 28 is inserted into the sensor holding portion 8 including the holding spring 9 while being changed to be fitted into the protrusion 86 from the other.

In the middle part of the combustion cylinder 1, as shown in FIG.
A thick band-shaped base plate 40 made of a metal plate is horizontally welded to the vicinity of the rectangular hole 12 provided in the tube wall 13 of the combustion tube 1. The base plate 40 has a substantially rectangular lower window hole 41 and a screw hole 4.
2 and the cut and raised portion 43 are opened. Base plate 40
A belt-shaped adjustment plate 44 made of a metal plate is slidably overlapped on the surface of.

The non-combustible sensor 5 includes two types of metal wires 51, 5
Linear heat-sensitive portion 54 including the second junction (hot junction) 53
And intermediate portions 55, 55 bent so that both sides of the heat-sensitive portion 54 are substantially V-shaped, and base portions 56, 56 bent parallel to the intermediate portions 55, 55. The bases 56 are held on the upper and lower sides of a rectangular mounting plate 57, and a notch-shaped screwing portion 58 is formed on the right side of the mounting plate 57. The non-combustible sensor 5 is mounted by fastening the adjusting plate 44 and the mounting plate 57 to the adjusting screw hole 42 of the base plate 40 with the adjusting screw 14.

The adjusting plate 44 is provided with an upper window hole 45 corresponding to the lower window hole 41, a horizontally long hole 46 for screw insertion, and slits 47 and 48 for engaging with the cut-and-raised portion 43. Thus, the non-combustible detection window 4 is formed by overlapping the upper window hole 45 with the lower window hole 41 corresponding to the rectangular hole 12, and the adjustment plate 44 is simply loosened by one adjustment screw 14.
By sliding with respect to the base plate 40, the area of the non-combustible detection window 4 can be accurately increased or decreased in two steps according to the engagement position.

The combustion tube 1 has a combustion chamber inside, around which a water guide pipe 11 is wound, and connected to a water pipe in a heat exchanger. The burner B is supplied with fuel gas via a safety valve S, and is ignited by an ignition device 15 to generate a combustion flame in the combustion cylinder 1 as shown in FIG. The misfire sensor 2 and the non-combustion sensor 5 are connected to a safety valve S, which is an electromagnetic valve provided in a gas supply path, via a control circuit 200, and constitute a safety device together with them. When the difference between the output of the misfire sensor 3 and the output of the non-combustible sensor 5 becomes equal to or less than a predetermined value, the safety valve S
To stop combustion.

In the above embodiment, the misfire sensor 2 was displaced in the vertical direction and the front-back direction when the specifications were switched.
Of course, in some cases, only one of them is sufficient. Further, the present invention may be applied to a combustor other than a water heater, and may be applied to a combustor without the non-combustible sensor 5.

[Brief description of the drawings]

FIG. 1 is a front view of a state in which a front surface of a housing of a water heater is removed.

FIG. 2 is a front view of fastening means of the misfire sensor.

FIG. 3 is a perspective view of a fastening means of the misfire sensor.

FIG. 4 is an assembled perspective view of a fastening means of the misfire sensor.

FIG. 5 is an assembled perspective view of an incomplete combustion sensor mounting mechanism.

FIG. 6 is a schematic configuration diagram of a safety device for a water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burning cylinder 2 Misfire sensor 3 Misfire sensor fastening means 6 Bracket 7 Misfire sensor holder 8 Sensor mounting part 9 Holding spring 22 Tip part (thermosensitive part) 31 Screw 61 Screw hole 62, 63 Engaged part 72 Long hole 73 Engagement Part 82 concave part 83 concave part 84 upper hand part 85 lower hand part 93 cylindrical part 100 water heater 200 safety device B burner S safety valve

Continued on the front page (56) References JP-A-8-42843 (JP, A) JP-A-61-291826 (JP, A) JP-A-63-61650 (JP, U) JP-A-58-21754 (JP) (U, U) Shokai 57-87947 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 5/10 310 F23N 5/02 341

Claims (2)

(57) [Claims] 1. A burner, a misfire sensor mounted so that a heat-sensitive part is close to a flame of the burner, holding means for the misfire sensor, and a safety device for closing a safety valve by an output of the misfire sensor. In the combustor, the holding means of the misfire sensor may be provided on a side surface of the burner provided with a screw hole, and an engaged portion for positioning at a plurality of predetermined positions provided at a predetermined distance vertically. A misfire sensor holder that is fastened and has a vertically long hole through which a screw screwed into the screw hole is inserted, and an engaging portion for positioning to engage with the engaged portion,
A combustor provided integrally with the misfire sensor holder, and a sensor mounting portion for holding the misfire sensor at an angle so that the heat-sensitive portion of the misfire sensor is close to the flame port side. 2. The device according to claim 1, wherein the sensor holding portion includes an upper hand portion and a lower hand portion each having a cylindrical recess for holding the misfire sensor in the inclined state. While being provided in the middle of the lower hand,
The holding spring is formed by bending a leaf spring into a substantially V shape and having a cylindrical portion for holding the misfire sensor. A combustor, wherein a bent side portion is fitted and fixed in the recess, and the misfire sensor can be fixed to the holding spring at a plurality of positions displaced by a predetermined distance in the axial direction and is detachably held.