JP4324854B2 - Combustion device - Google Patents

Description

  The present invention relates to a liquid fuel sensor that reliably detects the presence or absence of liquid fuel in a short time. The present invention proposed at the same time also relates to a combustion apparatus that detects liquid fuel leakage using a liquid fuel sensor.

  Even now that city gas and propane gas have become widespread, in order to reduce running costs, combustion devices that use inexpensive liquid fuel such as kerosene are frequently used. In such a combustion apparatus using liquid fuel, in order to avoid danger when liquid fuel leaks inside the apparatus, a liquid fuel sensor is incorporated to notify fuel leakage or shut off combustion operation. is there.

For example, Patent Document 1 employs an oil-swelling substance such as a silicone resin powder that swells by absorbing petroleum as a liquid fuel, and when the oil-swelling substance swells due to leaked oil, the piston is pressed by the swelling force. A leaked oil detection device that operates a pressure switch is disclosed.
Patent Document 2 also discloses a leaked oil detection device having a similar structure.

These detection devices disclosed in Patent Documents 1 and 2 can detect oil leakage in a short time by employing an oil-swelling substance having high lipophilicity.
Japanese Patent Laid-Open No. 02-189437 Japanese Utility Model Publication No. 02-107062

  However, the leaked oil detection devices disclosed in Patent Documents 1 and 2 must accurately measure a predetermined amount of an oil swelling substance such as silicone resin powder and fill the detection case, which is troublesome to manufacture. It was necessary.

  Accordingly, the inventors of the present application made a prototype of a liquid fuel sensor using, as an expansion member, a molded product of silicone rubber that exhibits expansion characteristics when immersed in petroleum instead of a swelling substance such as silicone resin powder. However, silicone rubber has a low oil absorption compared to silicone resin powder having high lipophilicity. For this reason, when the ratio of the silicone rubber soaked in petroleum is low, only the soaked portion only locally expands, and it is difficult to expand the expansion member as a whole. For this reason, it takes a long time to detect the leak after the fuel leak occurs, and a stable detection cannot be performed.

  The present invention has been proposed in view of the above circumstances, and an object thereof is to provide a liquid fuel sensor that is easy to manufacture and that reliably detects liquid fuel in a short time. Another object of the present invention proposed at the same time is to provide a combustion apparatus that employs a liquid fuel sensor as a liquid fuel leakage detection sensor to improve safety.

The invention according to claim 1 proposed to achieve the above object is a combustion apparatus for burning liquid fuel, wherein a fuel reservoir for collecting and retaining liquid fuel leaking from a fuel supply path inside the apparatus is provided, The fuel reservoir is provided below any fuel pipe connection part and fuel system member on the fuel supply path, and the leaked liquid fuel is directly from the fuel pipe connection part or fuel system member or other members. And a weir portion surrounding the fuel reservoir in an annular shape, and a liquid fuel sensor for detecting the presence or absence of liquid fuel is provided in the fuel reservoir. A housing member made of an oleophilic material having a large number of communicating micro spaces and allowing liquid fuel to permeate by capillary action, and the housing An expansion member that is accommodated inside the material and absorbs and expands the liquid fuel that permeates the housing member, a pressure receiving moving member that moves by receiving the expansion force of the expansion member, and a pressing member that accompanies the movement of the pressure receiving moving member. The housing member is a porous body in which countless holes are formed throughout, and the peripheral surface of the expansion member is in contact with the inner peripheral wall of the housing member. When the bottom of the housing member is immersed in the liquid fuel, the liquid fuel penetrates into the housing member, rises while the liquid fuel penetrates along the peripheral wall, and the expansion member absorbs the liquid fuel penetrated along the peripheral wall. and expands, the liquid fuel is kerosene, the housing member is a porous body obtained by sinter molding polypropylene resin material, wherein the expansion member is Ru are manufactured by molding the silicone rubber Preparative a combustion apparatus according to claim.

Liquid fuel sensor with the first aspect of the invention, can be detected reliably liquid fuel in a short time is easy to manufacture the structure is simple. This makes it possible to reliably detect a fuel leak that may occur in the combustion apparatus and perform necessary abnormality handling processing.

  Here, in the expansion member having high liquid fuel absorbability, the liquid fuel penetrates the entire expansion material in a short time and expands only by immersing a part of the expansion member in the liquid fuel. However, in the expansion member with low liquid fuel absorbability, even if a part of the expansion member is immersed in the liquid fuel, only the immersed part expands locally, and the entire expansion member does not expand uniformly and is sufficient. Expansion cannot be obtained.

  According to the present invention, when a part of the housing member is immersed in the liquid fuel, the liquid fuel flows into the micro space by capillary action and penetrates the entire housing member in a short time, and is accommodated in the housing member. The liquid fuel absorbs liquid fuel from all the inner walls in contact with the housing member and expands. Therefore, even when using an expansion member with low liquid fuel absorbency, the expansion member can absorb a large amount of liquid fuel in a short time compared to a structure in which the expansion member is immersed in the liquid fuel alone. Sufficient expansion force can be applied to the pressure-receiving moving member. Thereby, it becomes possible to detect liquid fuel reliably in a short time.

  Further, according to the present invention, in a combustion apparatus that burns liquid fuel, a liquid fuel sensor that collects and retains liquid fuel that leaks from a fuel supply path inside the apparatus is provided, and the liquid fuel sensor that detects the presence or absence of liquid fuel in the fuel reservoir It is set as the provided structure.

  The fuel reservoir can be set, for example, at a portion where a part of the flat plate material is recessed. According to this configuration, the liquid fuel leaking from all the parts where the liquid fuel may leak inside the combustion apparatus collects and stays in the fuel reservoir. Accordingly, the liquid fuel staying in the fuel reservoir can be detected by the liquid fuel sensor, and abnormality handling processing such as fuel leak notification and combustion stop can be performed, thereby improving the reliability of the apparatus.

  In the present invention, the fuel reservoir is provided below any fuel pipe connection part and fuel system member on the fuel supply path, and the leaked liquid fuel is directly from the fuel pipe connection part or fuel system member. Alternatively, it is configured to drop or flow into the fuel reservoir through another member.

  According to the present invention, the fuel reservoir is located below the portion where the liquid fuel may leak inside the combustion apparatus, that is, all the fuel pipe connections and fuel system members on the fuel supply path. Therefore, when the fuel pipe connection part or the fuel system member is located directly above the fuel reservoir, the leaked fuel can be dropped directly toward the fuel reservoir.

  Further, when the fuel pipe connection part or the fuel system member is not located directly above the fuel reservoir, the liquid fuel leaking through the other structural members inside the combustion apparatus can flow into the fuel reservoir. It is also possible to arrange an oil tray below a plurality of fuel pipe connections and fuel system members so that liquid fuel leaking into the tray is collectively dropped or flowed into the fuel reservoir.

  Moreover, in this invention, it is set as the structure which provided the dam part which encloses a fuel reservoir cyclically | annularly.

  According to the present invention, since the fuel reservoir is surrounded by the weir, even if rainwater flows into the combustion apparatus excluding the fuel reservoir, the rainwater does not enter the fuel reservoir due to being blocked by the weir. Thereby, water is not mixed into the leaked liquid fuel and detection of the liquid fuel is not hindered, and accurate fuel leak detection can be performed.

In addition, according to the present invention, the housing member has an oleophilic property, and when a part of the housing member is immersed in kerosene, the kerosene flows into a large number of holes formed inside the housing member due to capillary action in a short time. It penetrates the entire housing member. Thereby, it becomes possible to make the expansion member efficiently absorb kerosene and expand it in a short time. Further, the expansion member is a molded product of silicone rubber, and is easier to manufacture than a configuration using silicone resin powder or the like. Silicone rubber has a lower kerosene absorbability than silicone resin powder, but as described above, kerosene that has penetrated into the housing member can be absorbed in a large amount by silicone rubber in a short time, and the entire expansion member can be removed in a short time. It becomes possible to inflate uniformly.

  According to a second aspect of the present invention, in the liquid fuel sensor according to the first aspect, a relay member that relays and transmits the pressing force of the pressure receiving moving member to the detection switch is provided between the pressure receiving moving member and the detection switch. Has been.

  Here, when the expansion member expands unevenly, the pressure receiving movement member pressed by the expansion member may move while being inclined. For this reason, although the pressure receiving moving member is moving, the pressure receiving moving member does not come into contact with the pressing portion of the detection switch, and the detection switch does not operate. Further, if the expansion member directly pushes up the relay member without providing the pressure receiving moving member, the relay member bites into the expansion member, and the operation becomes unstable.

  According to the present invention, for example, it is possible to adopt a structure in which the relay member can be moved only in the direction of pressing and releasing the detection switch, and the relay member is brought into contact with the central portion of the pressure receiving moving member. According to this structure, even if the pressure receiving moving member moves while tilting in any direction, the pressure receiving moving member can be pressed against the relay member and the detection switch can be operated reliably. Become. Further, according to the present invention, by providing the relay member, the arrangement restriction between the pressure receiving moving member and the detection switch is relaxed, and the design can be easily performed.

  According to a third aspect of the present invention, in the liquid fuel sensor according to the first or second aspect, the housing member has a bottomed cylindrical shape, and a substantially columnar expansion member is accommodated inside the housing member, A substantially disc-shaped pressure receiving moving member is disposed adjacent to the expansion member at the opening of the housing member.

  According to the present invention, the bottom surface and the outer peripheral surface of the expansion member are in contact with the inner surface of the housing member. As a result, the liquid fuel that has penetrated the entire housing member can be absorbed in a large amount from the inner surface of the housing member into the expansion member in a short time, and the expansion member can be sufficiently expanded to detect the liquid fuel in a short time. Become.

  According to a fourth aspect of the present invention, in the liquid fuel sensor according to the third aspect, the housing member has a shape in which a small-diameter space provided on the bottom side communicates with a large-diameter space provided on the opening side. The expansion member has an outer diameter substantially equal to the inner diameter of the small-diameter space portion, the pressure-receiving moving member has an outer diameter substantially equal to the inner diameter of the large-diameter space portion, and the expansion member is accommodated in the small-diameter space portion The pressure receiving moving member is accommodated in the large-diameter space, and a predetermined clearance is formed between the expansion member and the pressure receiving moving member in a state where the expansion member does not absorb the liquid fuel.

  Here, it is also possible to adopt a configuration in which the expansion member and the pressure receiving moving member abut in a state where the expansion member does not absorb the liquid fuel, that is, in a state where the expansion member does not exhibit expansion. However, in this configuration, if a variation occurs in the dimensions of the expansion member at the time of manufacturing, the detection switch is operated due to the pressure receiving moving member being pressed due to the variation in the dimension even though the expansion member is not expanded.

  According to the present invention, the pressure-receiving moving member can move in the large-diameter space portion, and movement to the small-diameter space portion side is prohibited. Therefore, a predetermined clearance can be formed between the expansion member and the pressure receiving movement member by appropriately setting the height of the small diameter space portion. Thereby, even when the dimension of the expansion member varies during manufacturing, the variation in the dimension can be absorbed by the clearance, and the malfunction due to the dimension variation of the expansion member can be removed.

  Further, according to the present invention, since the outer diameter of the expansion member and the inner diameter of the small-diameter space portion of the housing member are substantially equal, the bottom surface and the peripheral surface of the expansion member abut on the bottom surface and the inner peripheral wall of the housing member in a short time. A large amount of liquid fuel is absorbed, and the expansion member expands in one direction toward the opening side of the housing member. Thereby, the amount of movement of the pressure receiving moving member due to the expansion of the expansion member can be increased, and the detection switch can be operated in a short time.

  In the present invention, the expansion member is accommodated in the small-diameter space inside the housing member, and the pressure-receiving / moving member is accommodated in the large-diameter space, but another configuration may be adopted. For example, it is also possible to adopt a configuration in which only the small-diameter space portion that accommodates the expansion member is provided inside the housing member, and the pressure-receiving moving member is brought into contact with the opening side of the housing member. Also in this configuration, by setting the height of the small-diameter space part appropriately, a predetermined clearance can be formed between the expansion member and the pressure receiving movement member, and the expansion member is directed toward the opening side. Can be expanded in the direction.

  According to a fifth aspect of the present invention, in the liquid fuel sensor according to any one of the first to fourth aspects, the fixed surface and the housing member are fixed when the liquid fuel sensor is fixed in contact with the surface where the liquid fuel stays. A predetermined clearance is provided between them.

  The liquid fuel sensor takes a long time until the expansion member returns to its original shape once the expansion member absorbs the liquid fuel and operates. Therefore, once the liquid fuel sensor is activated, the sensor itself is usually replaced or the expansion member is replaced. However, when laying or inspecting a combustion device or the like with a built-in liquid fuel sensor, liquid fuel is often accidentally leaked into the combustion device.

  According to the present invention, when the liquid fuel sensor is fixed to the fixed surface where the liquid fuel stays, a predetermined clearance is provided between the fixed surface and the housing member. Therefore, even if a small amount of liquid fuel leaks to the fixed surface, the leaked liquid fuel does not penetrate into the housing member, and the liquid fuel is not detected. This makes it possible to prevent unnecessary fuel detection even when liquid fuel is accidentally leaked during installation or inspection of a device incorporating the liquid fuel sensor.

  In the present invention, the fixing surface for fixing the liquid fuel sensor and the surface on which the leaked fuel stays may be the same, or the fixing surface may be positioned above the surface on which the leaking fuel stays. If the fixed surface is positioned above the surface where the leaked fuel stays, there is no need to provide a fixing screw opening for fixing the liquid fuel sensor on the surface where the leaked fuel stays, and the leaked fuel passes through the screw opening. Can be prevented from leaking outside.

According to a sixth aspect of the present invention, in the combustion device according to any one of the first to fifth aspects, the fuel reservoir has a flat portion and a stay portion formed by recessing a portion of the flat portion. The liquid fuel sensor is configured to be fixed to the flat portion across the staying portion and detect the presence or absence of liquid fuel in the staying portion.

  According to the present invention, since the liquid fuel sensor is fixed to the flat portion across the stay portion, the stay portion does not have a screw hole for fixing the liquid fuel sensor, and leaked fuel stays in the stay portion through the screw hole. Will not leak to the outside. In other words, the leaked fuel that should stay in the stay portion does not leak to the outside despite the fuel leak. As a result, the leaked fuel can be reliably retained in the retaining portion and the occurrence of fuel leakage can be accurately detected.

A seventh aspect of the present invention is the combustion apparatus according to the sixth aspect , wherein the liquid fuel sensor is fixed at a predetermined interval upward from the bottom surface of the stay portion provided in the fuel reservoir. Yes.

  According to the present invention, since the gap is provided between the bottom surface of the staying part and the liquid fuel sensor, even if a small amount of liquid fuel flows into the staying part, the inflowing liquid fuel is detected by the liquid fuel sensor. There is no. Therefore, even when liquid fuel is accidentally leaked during installation or inspection of the combustion apparatus, it is possible to prevent the liquid fuel sensor from being operated unnecessarily, and workability is improved.

The invention according to claim 8 is the combustion apparatus according to claim 6 or 7 , wherein a fuel pipe joint for supplying liquid fuel from the outside to the inside of the combustion apparatus is provided on the flat portion of the fuel reservoir. ing.

The fuel pipe joint connects a fuel pipe that supplies liquid fuel. Therefore, a portion corresponding to the fuel pipe connecting portion as referred in claim 1, a site of concern that leakage of liquid fuel occurs.
According to the present invention, since the fuel pipe joint is provided in the flat portion of the fuel reservoir, when a fuel leak occurs in the fuel pipe joint, the leaked fuel flows into the flat portion of the fuel reservoir and stays in the retaining portion. Therefore, it is possible to reliably detect the leakage of the liquid fuel that occurs at the fuel pipe joint.

The invention according to claim 9 is the combustion apparatus according to any one of claims 1 to 8 , wherein at least one of the exterior panels of the combustion apparatus is detachable, and any of the detachable exterior panels is provided. By detaching, the liquid fuel sensor provided in the fuel reservoir can be attached and detached.

As described above, the liquid fuel sensor takes a long time until the expansion member returns to its original shape once the expansion member absorbs the liquid fuel and is activated. Therefore, once the liquid fuel sensor is activated, it is necessary to replace the sensor itself or replace the expansion member.
According to the present invention, the liquid fuel sensor can be easily removed or attached by removing any exterior panel. As a result, when leakage of liquid fuel is detected by the liquid fuel sensor, the sensor itself or the expansion member can be replaced very easily by simply removing one of the exterior panels. improves.

According to the first and second aspects of the invention, it is possible to provide a liquid fuel sensor that reliably detects liquid fuel in a short time.
In addition, according to the first aspect of the present invention, it is possible to provide a combustion apparatus including a liquid fuel sensor that reliably detects kerosene in a short time by using an optimum material.
Further, according to the present invention, it is possible to reliably detect the leakage of liquid fuel with a simple structure, and to provide a combustion apparatus with improved safety.
According to invention of Claim 3, 4, it becomes possible to implement the combustion apparatus of Claim 1, 2 with a simple structure.
According to invention of Claim 5, the combustion apparatus provided with the liquid fuel sensor which improved installation property and maintenance property can be provided.
According to invention of Claims 6-9 , the combustion apparatus which improved laying property and maintenance property can be provided.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing a liquid fuel sensor 10 according to an embodiment of the present invention. 2 and 3 are partially exploded perspective views of members constituting the liquid fuel sensor 10 shown in FIG. 1, FIG. 4 is a perspective view of a frame member 20 used in the liquid fuel sensor 10 shown in FIG. 1, and FIG. 1 is an exploded perspective view of a liquid fuel sensor 10 shown in FIG. 6 is a cross-sectional view taken along arrows AA and BB of FIG. 1, and FIG. 7 is an explanatory view showing an operation of the liquid fuel sensor 10.

As shown in FIG. 1, the liquid fuel sensor 10 according to the present embodiment includes a frame member 20, a housing member 30, a relay member 11, a holding member 40, and a detection switch 50. A pressure receiving moving member is accommodated.
The liquid fuel sensor 10 is a sensor that is fixed inside a combustion device or the like and has a function of operating the detection switch 50 by detecting the presence or absence of liquid fuel (kerosene in the present embodiment).

Below, the structure of the liquid fuel sensor 10 is demonstrated in detail, showing the structure and assembly procedure of each member.
As shown in FIG. 2, the holding member 40 is a member in which a rectangular plate-like switch fixing portion 42 is erected in a vertical direction on a substantially rhombus pedestal 41. The holding member 40 is a member having a function of positioning and fixing the detection switch 50 with respect to the frame member 20, and is manufactured by molding a synthetic resin material.

The switch fixing portion 42 is erected vertically on the side edge of the pedestal 41 so as to be inclined with respect to the longitudinal center line. The switch fixing portion 42 has two fixing holes 46 and 46 for fixing the detection switch 50. Is opened.
A columnar positioning portion 43 that protrudes downward is provided at the center of the lower surface of the pedestal 41, and a through hole 44 that penetrates from the center of the upper surface of the pedestal 41 to the positioning portion 43 in the vertical direction is opened. Further, fixed openings 45, 45 are provided in the vicinity of both longitudinal ends of the base 41 so as to penetrate in the vertical direction.

  The detection switch 50 is a substantially rectangular parallelepiped member that is slightly lower in height than the switch fixing portion 42 of the holding member 40, and a small pressing piece 52 projects downward from the center of the lower surface, and three upper surfaces are provided on the upper surface. Terminals 53a to 53c are provided. The pressing piece 52 is always biased downward and protrudes, and when the pressing piece 52 protrudes, the terminals 53a and 53c are electrically connected. On the other hand, when the pressing piece 52 is pushed upward against the urging force, the continuity between the terminals 53a and 53c is interrupted and the terminals 53b and 53c are electrically connected. In the present embodiment, a general-purpose micro switch is used as the detection switch 50.

  As shown in FIG. 2, the detection switch 50 is provided with two fixed openings 57 penetrating in the front-rear direction. Further, lead wires 55 and 55 each having a connector 51 at the tip are connected to the terminals 53 a and 53 c of the detection switch 50 and covered with an insulating cover 54.

  As shown in FIG. 2, the relay member 11 is a small member in which a disc-shaped seat portion 11b is formed on the upper end of a columnar body portion 11a, and is manufactured by molding a synthetic resin material. The outer diameter of the main body 11a of the relay member 11 is smaller than the outer diameter of the seat 11b. The outer diameter of the main body 11a is substantially the same as the inner diameter of the through hole 44 provided in the base 41 of the holding member 40, and the lower end of the main body 11a is hemispherical.

  The holding member 40, the relay member 11, and the detection switch 50 are pre-assembled by the following procedure. First, as shown in FIG. 2, the main body 11 a of the relay member 11 is inserted into the through hole 44 provided in the base 41 of the holding member 40. When the relay member 11 is inserted into the holding member 40, the seat portion 11 b comes into contact with the upper surface of the base 41, and the main body portion 11 a slightly protrudes downward from the positioning portion 43 of the holding member 40.

  Next, with the relay member 11 inserted into the holding member 40, the detection switch 50 is brought into contact with the switch fixing portion 42 of the holding member 40. Then, the fixing screw 56 is screwed into the fixing hole 46 of the switch fixing portion 42 through the fixing opening 57 of the detection switch 50 and fixed. In this embodiment, a self-tapping screw is used for the fixing screw 56, and it is fixed by screwing into a fixing hole 46 provided in the switch fixing portion 42 made of a resin material.

  In this way, when the relay member 11 and the detection switch 50 are attached to the holding member 40, the pressing piece 52 of the detection switch 50 is located close to the upper portion of the seat 11b of the relay member 11, as shown in FIG. The relay member 11 is integrated without falling out of the through hole 44 of the holding member 40.

The housing member 30 is a bottomed cylindrical member as shown in FIG. 3, and a small-diameter space portion 33 is formed on the bottom portion 31 side, and a large-diameter space portion 34 is formed on the opening portion 32 side. The small diameter space portion 33 and the large diameter space portion 34 communicate with each other, and a step portion 35 that is slightly inclined upward is formed at the communication portion. Further, a flange portion 36 is formed at the upper end of the housing member 30 so as to spread outward in the radial direction over the entire circumference.
In this embodiment, the housing member 30 is manufactured by sintering and molding a polypropylene resin particle material having a particle diameter of approximately 300 μm. The sintered and molded housing member 30 is a porous body in which countless holes having an average diameter of approximately 50 μm are formed throughout, and has water repellency and lipophilicity.

The expansion member 13 is a cylindrical member as shown in FIG. 3 and has an outer diameter substantially equal to the inner diameter of the small-diameter space portion 33 of the housing member 30, and its height is slightly higher than the height of the small-diameter space portion 33. Low.
In this embodiment, the expansion member 13 is manufactured by molding silicone rubber, and has a property of absorbing kerosene and expanding.

  As shown in FIG. 3, the pressure-receiving moving member 12 is a substantially disk-shaped member, and its peripheral edge has a rounded shape. Here, the pressure receiving moving member 12 is accommodated perpendicularly to the central axis in the housing member 30 as described later, and moves in the axial direction by the expansion of the expansion member 13. Therefore, the peripheral edge of the pressure-receiving moving member 12 is rounded to prevent the pressure-receiving moving member 12 from being inclined and held on the inner wall of the housing member 30 when moving. In the present embodiment, the pressure-receiving moving member 12 is manufactured by molding a synthetic resin material.

  The expansion member 13 and the pressure receiving movement member 12 are sequentially inserted into the housing member 30 in advance during assembly. That is, the expansion member 13 is inserted into the small-diameter space portion 33 of the housing member 30, and the pressure-receiving / moving member 12 is inserted into the large-diameter space portion 34 so as to cover the expansion member 13. When the members 12 and 13 are inserted into the housing member 30, the lower peripheral edge of the pressure receiving moving member 12 abuts on the step portion 35 of the housing member 30, and a slight clearance is provided between the pressure receiving moving member 12 and the expansion member 13. Is formed. This clearance will be described later.

As shown in FIG. 4, the frame member 20 is a substantially square cylindrical member surrounded by four wall portions 21, and is manufactured by press-molding a die-cut metal plate.
The four wall portions 21 are die-cut in a continuous state, and an overlapping portion 26 is provided at one end. The overlapping portion 26 has two positioning openings 21a in the vertical direction, and a positioning projection 21b is provided on the wall 21 at the other end corresponding to the positioning opening 21a. The four continuous wall portions 21 are bent into a tubular shape, and are fixed by spot welding S at the center with the positioning opening 21a of the overlapping portion 26 fitted in the positioning projection 21b.

  A pair of support portions 22 and 22 and a pair of positioning portions 23 and 23 extending from the wall portion 21 are provided on the upper edge of the wall portion 21. In addition, a pair of fixing portions 25 and 25 and a pair of contact portions 24 and 24 extending from the wall portion 21 are provided on the lower edge of the wall portion 21.

  The support portion 22 is formed by extending the upper edge of the wall portion 21, and the extending portion is bent horizontally and vertically outward and then is bent again in the horizontal direction. A step portion 22a is formed by the upper surface where the extension portion is first bent in the horizontal direction. A fixing hole 22 b is provided in the horizontal portion at the upper end of the support portion 22. The support portions 22 are respectively provided on the upper edges of the opposing wall portions 21.

  The positioning portion 23 is formed by slightly extending a part of the upper edge of the wall portion 21, and the extending portion is bent in the horizontal direction outward. The positioning portion 23 is provided on the upper edge of the wall portion 21 adjacent to the wall portion 21 on which the support portion 22 is provided. Moreover, the upper surface of the positioning part 23 and the step part 22a of the support part 22 are made into the shape included in the substantially same plane.

The fixing portion 25 is formed by extending a part of the lower edge of the wall portion 21, the extending portion is bent in the horizontal direction outward, and a fixing opening 25 a is provided at the tip. The fixing portions 25 are respectively provided on the lower edge of the wall portion 21 where the positioning portion 23 is provided.
The contact portion 24 is formed by slightly extending the lower edge of the wall portion 21, and the extended portion is bent in the horizontal direction outward. The contact portions 24 are provided on the lower edge of the wall portion 21 on which the support portion 22 is provided. The frame member 20 is made by press-molding a metal plate, but may be made by processing a material such as resin.

Each member constituting the liquid fuel sensor 10 of the present embodiment has been described. Next, a procedure for assembling the liquid fuel sensor 10 by combining these members will be described.
As shown in FIG. 5, first, the housing member 30 (see FIG. 3) that accommodates the expansion member 13 and the pressure-receiving moving member 12 is inserted from the bottom 31 side into a portion surrounded by the wall portion 21 of the frame member 20. When the housing member 30 is inserted into the frame member 20, the flange portion 36 of the housing member 30 contacts and is supported by the positioning portion 23 and the step portion 22 a of the frame member 20.

  Next, the holding member 40 pre-assembled by the procedure of FIG. 2 is brought into contact with the frame member 20 so as to cover the housing member 30. At the time of contact, the positioning portion 43 of the holding member 40 is fitted into the opening 32 of the housing member 30 so that the fixing opening 45 of the holding member 40 and the fixing hole 22b of the frame member 20 are aligned. Then, the fixing screw 47 is screwed into the fixing hole 22 b of the frame member 20 through the fixing opening 45 of the holding member 40 and fixed. In the present embodiment, a self-tapping screw is used for the fixing screw 47, and the fixing screw 22 is screwed into the fixing hole 22b of the frame member 20 and fixed.

  The assembly of the liquid fuel sensor 10 of the present embodiment shown in FIG. 1 is completed by the above procedure. In the assembled liquid fuel sensor 10, as shown in FIG. 6A, a clearance d <b> 1 is formed between the expansion member 13 accommodated in the housing member 30 and the pressure receiving movement member 12. In other words, when the expansion member 13 having a specified size is used, a clearance d1 is formed between the expansion member 13 and the pressure receiving movement member 12.

Here, as described above, in the present embodiment, since the silicone rubber is employed for the expansion member 13, a dimensional deviation of the expansion member 13 is likely to occur during manufacturing. For this reason, when the height of the expansion member 13 is larger than the specified dimension, there is a tendency that the pressure receiving moving member 12 is pressed upward when the liquid fuel sensor 10 is assembled and the detection switch 50 is activated.
However, by providing the above-described clearance d1, it is possible to avoid a malfunction due to a dimensional deviation of the expansion member 13 during manufacturing.

  Further, as shown in FIG. 6A, the liquid fuel sensor 10 of the present embodiment has a configuration in which the contact portion 24 provided at the lower portion of the frame member 20 protrudes downward from the bottom portion 31 of the housing member 30. Yes. That is, the clearance d <b> 2 is provided between the bottom 31 of the housing member 30 and the lower surface of the contact portion 24. Accordingly, when the contact portion 24 of the liquid fuel sensor 10 is fixed to the surface (not shown) where the leaked fuel stays, the fuel detection is not performed until the leaked fuel reaches the height of the clearance d2. Thus, even when a small amount of fuel is accidentally leaked during installation or inspection of a combustion device or the like incorporating the liquid fuel sensor 10, unnecessary fuel detection can be eliminated.

  Further, in the liquid fuel sensor 10 of the present embodiment, a clearance d3 is provided between the fixed portion 25 and the contact portion 24 of the frame member 20, as shown in FIG. 6B. In other words, when the liquid fuel sensor 10 is fixed, a structure is provided in which a step of height d3 is provided between the liquid fuel staying surface with which the contact portion 24 abuts and the fixing surface with which the fixing portion 25 abuts. Adopted. Thus, as will be described later, the structure in which the opening of the fixing screw is not provided on the liquid fuel staying surface is configured to prevent the fuel from leaking from the opening.

  Note that the liquid fuel sensor 10 of the present embodiment has a configuration in which a clearance d3 is provided between the fixed portion 25 and the contact portion 24 of the frame member 20 as shown in FIG. It is also possible to adopt a configuration not provided. Further, instead of providing the contact portion 24, it is possible to adopt a configuration in which the clearance d2 shown in FIG.

  Next, the operation principle of the liquid fuel sensor 10 of the present embodiment will be described with reference to FIG. FIG. 7 shows a state in which the contact portion 24 of the liquid fuel sensor 10 is fixed in contact with the bottom plate M where the liquid fuel L stays.

  As shown in FIG. 7A, since the housing member 30 is not immersed in the liquid fuel L until the height of the liquid fuel L staying in the bottom plate M reaches the clearance d2, the detection operation of the liquid fuel L is performed as described above. Not done. In this state, the terminals 53a and 53c of the detection switch 50 are electrically connected.

  On the other hand, when the liquid fuel L staying in the bottom plate M increases and the height exceeds the clearance d2, the bottom 31 of the housing member 30 is immersed in the liquid fuel L locally as shown in FIG. However, as described above, the housing member 30 is a porous body in which numerous holes are formed. Accordingly, when the bottom portion 31 of the housing member 30 is immersed in the liquid fuel L, the liquid fuel L penetrates into the housing member 30 and rises while penetrating the liquid fuel L along the peripheral wall of the small diameter space portion 33 in a short time. . Thereby, the expansion member 13 accommodated in the small diameter space portion 33 expands by absorbing the liquid fuel L that has permeated along the bottom portion 31 and the peripheral wall of the small diameter space portion 33. However, since the expansion member 13 has an outer diameter substantially equal to the inner diameter of the small-diameter space portion 33 before expansion, the expansion member 13 expands in one direction upward as the liquid fuel L is absorbed.

  Until the upper surface of the expansion member 13 reaches the stepped portion 35, the pressure receiving moving member 12 is not pressed as shown in FIG. However, when the expansion proceeds and the upper surface of the expansion member 13 reaches the stepped portion 35 as shown in FIG. 7B, the pressure receiving moving member 12 is pressed upward and moves in accordance with the expansion of the expansion member 13. . Thereby, the relay member 11 moves upward and presses the pressing piece 52 of the detection switch 50 to perform fuel detection. In this state, the conduction between the terminals 53a and 53c of the detection switch 50 is interrupted, and the terminals 53b and 53c are conducted.

  Therefore, by incorporating the liquid fuel sensor 10 in a combustion device or the like and adopting a circuit configuration that allows combustion only during a period in which the terminals 53a and 53c of the detection switch 50 are electrically connected, combustion is performed simultaneously with fuel detection. It is possible to stop. Moreover, it is also possible to employ a configuration in which fuel leakage is notified by conduction between the terminals 53b and 53c of the detection switch 50.

  As described above, according to the liquid fuel sensor 10 of the present embodiment, the porous fuel is used for the housing member 30 in spite of using the silicone rubber having low absorbability of the liquid fuel L as the expansion member 13. The penetration of L is promoted, and a large amount of liquid fuel L is absorbed in a short time from the bottom surface and peripheral portion of the expansion member 13. This makes it possible to perform stable fuel detection by performing sufficient expansion in a short time. In addition, since silicone rubber is used for the expansion member 13, it is possible to remarkably improve manufacturability compared to a configuration using silicone resin powder or the like.

  In the above-described embodiment, the configuration in which the pressing force of the pressure-receiving moving member 12 is transmitted to the detection switch 50 via the relay member 11 is adopted. However, a configuration in which the detection switch 50 is directly operated by the pressure-receiving moving member 12 may be adopted. Is possible.

  In the above embodiment, as shown in FIG. 6A, a clearance d2 is provided between the contact portion 24 of the frame member 20 and the bottom portion 31 of the housing member 30, so that minute fuel leakage is caused during laying and inspection. However, it is possible to adopt a configuration in which the clearance d2 is not provided.

Next, an embodiment of the combustion apparatus 2 that incorporates the liquid fuel sensor 10 of the present embodiment and detects liquid fuel leakage will be described. In the following description, the combustion apparatus 2 provided with the liquid fuel sensor 10 is described as being built in the hot water supply apparatus 1.
8 is a front view and a side view of a hot water supply apparatus 1 incorporating a combustion apparatus 2 according to an embodiment of the present invention, FIG. 9 is a plan view showing a fuel reservoir 3 provided in the combustion apparatus 2 shown in FIG. 8, and FIG. 3 is a cross-sectional view showing the fuel reservoir 3. FIG.

As shown in FIG. 8A, the hot water supply device 1 is formed by housing each member including the combustion device 2 of the present embodiment inside a rectangular box 70 and is supplied via a water supply port 75. It is an apparatus having a function of heating water and sending hot water at a predetermined temperature from a hot water supply port 76.
The box body 70 is formed to include a detachable front panel (exterior panel) 70 a and side panel 70 b (exterior panel), and a bottom plate 74 is provided at the bottom of the box body 70.

  As shown in FIGS. 8A and 8B, the combustion device 2 includes a fuel pipe 66, an electromagnetic pump 60, a fuel injection unit 61, a fan 63, and a combustion unit 62. The combustion device 2 pumps liquid fuel (kerose oil is used in the present embodiment) supplied through the fuel pipe 66 to the fuel injection unit 61 by the electromagnetic pump 60, and kerosene and the fan 63 injected from the fuel injection unit 61. The combustion gas is generated by burning the fuel gas mixed with the air supplied from the combustion section 62. The combustion gas generated in the combustion device 2 is heat-exchanged with water in the downstream heat exchanger 71, and the heated hot water is mixed with water and the temperature is adjusted, and then from the hot water supply port 76 to a hot water supply terminal (not shown). Sent out. Further, the heat exchanged combustion gas passes through the exhaust duct 72 as exhaust gas and is discharged from the exhaust head 73 to the outside.

  Here, in the combustion device 2 of the present embodiment, as shown in FIG. 8A, a fuel reservoir 3 for retaining kerosene leaking from the combustion device 2 is provided at the left end portion of the bottom plate 74. As shown in FIGS. 9 and 10, the fuel reservoir 3 is formed inside an annular weir portion 6 formed by bending the bottom plate 74 upward along a substantially elliptical shape. The fuel reservoir 3 is formed with a flat portion 4 that is higher than the bottom plate 74 and lower than the top of the weir portion 6, and the fuel reservoir 3 functions as a portion for retaining leaking kerosene.

  As shown in FIGS. 9 and 10, the fuel pipe joint 65 and the liquid fuel sensor 10 shown in the above embodiment are fixed to the flat portion 4 of the fuel reservoir 3. The fuel pipe joint 65 connects a fuel supply pipe (not shown) extending from the outside and a fuel pipe 66 extending inside the combustion apparatus 2, and spreads radially outward in the center of the cylindrical joint body 65a. A disk-shaped fixing flange 65b is provided. The fuel pipe joint 65 is fixed by passing the joint body 65 a through the flat surface portion 4 and fastening the fixing flange 65 b to the flat surface portion 4 with a fixing screw 68.

  The liquid fuel sensor 10 is fixed to the fuel reservoir 3 adjacent to the fuel pipe joint 65 as shown in FIGS. In a portion where the liquid fuel sensor 10 is fixed, a staying portion 5 formed by recessing the flat portion 4 in a circular shape is provided. In the present embodiment, the distance between the bottom surface of the staying portion 5 and the upper surface of the flat portion 4 is substantially the same as the clearance d3 shown in FIG. Further, the staying portion 5 is provided so that the bottom surface of the staying portion 5 and the upper surface of the bottom plate 74 are substantially at the same height.

  As shown in FIGS. 9 and 10, the liquid fuel sensor 10 is fixed to the flat portion 4 across the stay portion 5. In other words, the liquid fuel sensor 10 is fixed by fixing the abutting portion 24 to the staying portion 5, bringing the fixing portions 25, 25 into contact with the flat portion 4, and fastening with the fixing screw 27. Here, as described above, the distance between the bottom surface of the staying portion 5 and the top surface of the flat portion 4 is substantially the same as the clearance d3. Therefore, when the liquid fuel sensor 10 is fixed to the flat portion 4, the contact of the frame member 20 is reduced. The contact portion 24 contacts the bottom surface of the staying portion 5.

  Moreover, in the combustion apparatus 2 of this embodiment, the oil tray 64 is provided in the lower part of the electromagnetic pump 60 and the fuel injection part 61 as shown to Fig.8 (a). In addition, an inclined plate 67 is arranged below the oil tray 64 so as to be close to the bottom plate 74.

  Here, in the hot water supply apparatus 1 (combustion apparatus 2) of the present embodiment, a part where fuel leakage may occur is considered. First, as shown in FIG. 10, the connecting portion 69a of the fuel pipe joint 65 and the fuel pipe 66 is cited as a portion where there is a risk of fuel leakage. Further, as shown in FIG. 8A, the fuel pipe 66 and the connection part 69b between the electromagnetic pump 60, the pipe connection parts 69c and 69d extending from the electromagnetic pump 60 to the fuel injection part 61, and the fuel injection part 61 itself are also fuel. It is mentioned as a part with a possibility of leakage.

  In the combustion apparatus 2 of the present embodiment, when fuel leaks from the above-described part, all the leaked fuel is collected in the fuel reservoir 3. In other words, when fuel leaks from the connecting portion 69a of the fuel pipe joint 65 and the fuel pipe 66, the leaked kerosene flows through the joint main body 65a and flows to the flat portion 4 of the fuel reservoir 3 as shown in FIG.

  On the other hand, the fuel leaking from the connecting portions 69b to 69d and the fuel injection portion 61 is once received by the oil tray 64 and vertically inclined from the oil tray 64 as shown in FIGS. 8 (a) and 8 (b). Drip into Then, the dropped leaked fuel travels along the inclined plate 67 and drops into the fuel reservoir 3.

  The leaked fuel that has flowed into the fuel reservoir 3 in this way flows through the flat portion 4 and flows into the staying portion 5 and stays there, as shown in FIGS. Then, when the fuel staying in the staying portion 5 increases and reaches the level where the housing member 30 of the liquid fuel sensor 10 is immersed, leakage detection is performed by the above-described operation (see FIG. 7), and abnormality notification, combustion stop, etc. Necessary abnormality handling processing is performed.

  Further, in the present embodiment, as described above, the stay part 5 in which a part of the flat part 4 is further recessed in the fuel reservoir 3 is provided, and a through hole for fastening the fixing screw is provided in the stay part 5. No structure (see FIG. 10). Therefore, when the fuel leaks and the leaked fuel flows into the flat portion 4, the leaked fuel that has flowed flows from the flat portion 4 to the staying portion 5, so that the fuel does not always stay in the flat portion 4. Thereby, it is possible to effectively prevent the fuel from leaking from the through hole for fastening the fixing screws 27 and 68 to the outside.

  Thus, according to the combustion apparatus 2 of the present embodiment, by incorporating the liquid fuel sensor 10, it is possible to reliably detect a fuel leak inside the apparatus in a short time, and to significantly improve safety. It becomes possible. In addition, since a predetermined clearance is provided between the housing member 30 of the liquid fuel sensor 10 and the bottom surface of the staying part 5, even if a slight fuel leak is accidentally generated during installation or inspection, it is detected unnecessarily. It is possible to improve layability and maintainability.

  Moreover, in the hot water supply apparatus 1 of this embodiment, the liquid fuel sensor 10 fixed to the fuel reservoir 3 can be easily removed by removing the front panel 70a or the side panel 70b as shown in FIGS. It is possible to exchange. Thereby, even when fuel leakage is detected, the liquid fuel sensor 10 can be efficiently exchanged in a short time, and workability can be improved.

  In the above-described embodiment, the planar portion 4 of the fuel reservoir 3 has a planar structure that is not inclined, but the planar portion 4 may be slightly inclined downward toward the staying portion 5. According to this structure, the leaked fuel flowing into the flat portion 4 can be quickly flowed to the staying portion 5 along the inclination, and leaks to the outside from the through holes of the fixing screws 27 and 68 provided on the flat portion 4. It becomes possible to further prevent the fuel from leaking.

  Moreover, in the said embodiment, although the structure which further provided the stay part 5 in the plane part 4 of the fuel reservoir 3 was employ | adopted, this invention is not restricted to such a structure, It can also be set as the structure which abbreviate | omitted the stay part 5. Is possible. For example, a configuration may be adopted in which leaked fuel is retained throughout the flat surface portion 4 by applying a sealant or the like to a through hole provided in the flat surface portion 4 to fix the fixing screws 27 and 68 to prevent leakage. In the case of adopting this configuration, the liquid fuel sensor 10 shown in FIG. 6B uses a configuration in which the fixing portion 25 of the frame member 20 is aligned with the contact portion 24 and the clearance d3 is removed. Can do.

1 is a perspective view showing a liquid fuel sensor according to an embodiment of the present invention. It is a partial exploded perspective view of the member which comprises the liquid fuel sensor of FIG. It is a partial exploded perspective view of the other member which comprises the liquid fuel sensor of FIG. It is a perspective view of the frame member used for the liquid fuel sensor of FIG. It is a disassembled perspective view of the liquid fuel sensor of FIG. (A) is AA arrow sectional drawing of FIG. 1, (b) is BB arrow sectional drawing of FIG. (A), (b) is explanatory drawing which shows operation | movement of the liquid fuel sensor of FIG. (A) is a front view of the hot water supply apparatus incorporating the combustion apparatus which concerns on embodiment of this invention, (b) is the side view. It is a top view which shows the fuel pool provided in the combustion apparatus of FIG. It is sectional drawing which shows the fuel pool provided in the combustion apparatus of FIG.

2 Combustion device 3 Fuel pool 4 Flat portion 5 Retaining portion 6 Weir portion 10 Liquid fuel sensor 11 Relay member 12 Pressure receiving member 13 Expansion member 30 Housing member 31 Bottom portion 32 Opening portion 33 Small diameter space portion 34 Large diameter space portion 50 Detection switch 60 , 61 Fuel system member (electromagnetic pump, fuel injection part)
65 Fuel piping connection (combustion piping joint)
70a Exterior panel (front panel)
70b Exterior panel (side panel)
d1 Clearance (clearance between the expansion member and the pressure-receiving moving member)

Claims (9)

In a combustion apparatus for combusting liquid fuel, a fuel reservoir for collecting and retaining liquid fuel leaking from a fuel supply path inside the apparatus is provided, and the fuel reservoir includes any fuel pipe connection portion and fuel system member on the fuel supply path. The liquid fuel that is provided below and leaks and drops or flows from the fuel pipe connection part or the fuel system member directly or through another member to the fuel reservoir, and further surrounds the fuel reservoir in an annular shape. A liquid fuel sensor is provided to detect the presence or absence of liquid fuel in the fuel reservoir, and the liquid fuel sensor has a large number of communicating micro spaces inside, and the liquid fuel sensor permeates the liquid fuel by capillary action. A housing member made of an oily material, and a liquid fuel that is accommodated in the housing member and penetrates into the housing member An expansion member that absorbs and expands; a pressure-receiving moving member that moves by receiving an expansion force of the expansion member; and a detection switch that is opened and closed by a pressing force associated with the movement of the pressure-receiving moving member, Is a porous body in which innumerable holes are formed throughout, and the peripheral surface of the expansion member is in contact with the inner peripheral wall of the housing member, and the liquid fuel is contained in the housing when the bottom of the housing member is immersed in the liquid fuel. The liquid member penetrates into the member and rises while penetrating the liquid fuel along the peripheral wall, the expansion member absorbs the liquid fuel penetrating along the peripheral wall and expands , the liquid fuel is kerosene, and the housing member combustion apparatus is a porous body of polypropylene resin material and sinter molding, the expansion member, characterized in Rukoto is manufactured by molding the silicone rubber.   The combustion apparatus according to claim 1, wherein a relay member that relays and transmits a pressing force of the pressure receiving moving member to the detection switch is provided between the pressure receiving moving member and the detection switch.   The housing member has a cylindrical shape with a bottom, a substantially columnar expansion member is accommodated in the housing member, and a substantially disk-shaped pressure receiving and moving member adjacent to the expansion member in an opening of the housing member. The combustion apparatus according to claim 1, wherein the combustion apparatus is disposed.   The housing member has a shape in which a small-diameter space portion provided on the bottom side and a large-diameter space portion provided on the opening side are communicated, and the expansion member has an outer diameter substantially equal to the inner diameter of the small-diameter space portion. The pressure receiving moving member has an outer diameter substantially equal to the inner diameter of the large diameter space portion, the expansion member is accommodated in the small diameter space portion, and the pressure receiving movement member is accommodated in the large diameter space portion, The combustion apparatus according to claim 3, wherein a predetermined clearance is formed between the expansion member and the pressure-receiving moving member in a state where the liquid fuel is not absorbed.   The predetermined clearance is provided between the fixed surface and the housing member when the liquid fuel sensor is fixed in contact with the surface on which the liquid fuel stays. The combustion apparatus as described. The fuel reservoir has a flat part and a staying part formed by recessing a part of the flat part, and the liquid fuel sensor is fixed to the flat part across the staying part and the liquid fuel in the staying part The combustion apparatus according to any one of claims 1 to 5 , wherein the presence or absence of fuel is detected. The combustion apparatus according to claim 6 , wherein the liquid fuel sensor is fixed at a predetermined interval upward from a bottom surface of a retention portion provided in the fuel reservoir. Wherein the flat portion of the reservoir fuel combustion apparatus according to claim 6 or 7, characterized in that the fuel pipe joint performing internal to the supply of the liquid fuel combustion apparatus is externally provided. At least one of the exterior panels of the combustion device is detachable, and the liquid fuel sensor provided in the fuel reservoir can be detached by removing any of the detachable exterior panels. Item 9. The combustion apparatus according to any one of Items 1 to 8 .

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