WO2013114846A1 - Heat exchanger and method for producing same, and sanitary washing apparatus provided with heat exchanger - Google Patents

Abstract

This heat exchanger is provided with: a casing comprising a first flow path forming member (21) and a second flow path forming member (22), which are provided with flow path ribs on at least one inner wall surface; and a flat plate-like heater (20) enclosed inside the casing. Furthermore, the heat exchanger has: recessed main flow paths (25) formed by the flow path ribs and flat plate-like heater (20); and leakage flow paths (41) formed by the gaps between the upper surfaces of the flow path ribs and the surfaces of the flat plate-like heater (20). The leakage flow path (41) gaps are from 0.05 mm to 15 mm. A heat exchanger that prevents the generation of local boiling of washing water at the surfaces of the flat plate-like heater (20), and has excellent stable heat exchanging performance and scaling resistance can thus be achieved.

Description

HEAT EXCHANGER, MANUFACTURING METHOD THEREOF, AND SANITARY CLEANING DEVICE PROVIDED WITH THE SAME

The present invention relates to an instantaneous heating type heat exchanger used in a sanitary washing apparatus for washing a human body part with warm water after a toilet, a manufacturing method thereof, and a sanitary washing apparatus provided with them.

Conventionally, sanitary washing devices have been equipped with a heat exchanger for making the wash water an appropriate temperature when washing the human body part after the toilet with water. Various types of heat exchangers have been developed, and for example, a flat plate heat exchanger is disclosed (see, for example, Patent Document 1).

In the heat exchanger described in Patent Document 1, a flat heater is housed vertically in a rectangular parallelepiped casing having a small thickness dimension, and the horizontal direction along each of the heat transfer surfaces on the front and back of the flat heater. Two flow paths are formed which meander to each other and go upward. Then, the cleaning water that flows is heated to an appropriate temperature by allowing the cleaning water to flow along each flow path while heating the flat heater. At this time, the heat exchanger disclosed in Patent Document 1 speeds up and equalizes the flow rate of the washing water by reducing the flow path cross-sectional area. Thereby, while improving the heat transfer rate to washing water, it is supposed that size reduction can be attained.

Usually, a heat exchanger for instant water heating that heats cleaning water in a sanitary washing device is used to heat water at a maximum flow rate of about 0.5 L / min to 40 ° C. hot water with 5 ° C. incoming water. About 1200W is required as input power. Therefore, a heater having a relatively high watt density with a watt density of about 20 W / cm ² to 50 W / cm ² is used for the flat heater.

However, in the conventional heat exchanger, the maximum flow rate passing through the heat exchanger is as low as about 0.5 L / min. For this reason, there are problems such as stability of operation in the heat exchanger and adhesion of scale to the heater surface when used in a hard water area.

Also, in order to stabilize the heat exchange conditions of the heat exchanger, it is necessary to perform heat exchange by forced convection heat transfer without boiling heat transfer. Therefore, in order to ensure the flow rate of the washing water flowing on the surface of the heater in the heat exchanger, a flow path rib is provided on the inner wall side of the casing constituting the outer frame of the heat exchanger in the vicinity of the flat heater. The cleaning water is passed through a flow path provided between the flow path ribs and the flat heater. Thereby, the heat transfer by forced convection heat exchange is promoted.

In other words, a conventional heat exchanger using a flat heater induces forced convection on the heater surface and ensures that the flow rate is maintained while flowing cleaning water uniformly over the heater surface, thereby transferring heat on the heater surface. It is configured to promote

However, in the conventional heat exchanger, the main surface, which is a meandering heat exchange channel composed of the channel rib and the heater surface, and the tip of the heater surface and the channel rib (heater so as to leak from between adjacent main channels) There is a problem that forced convection heat exchange is hindered by a leak flow that flows through a gap between the first and second portions.

That is, in the conventional heat exchanger, the flow path rib provided close to the flat heater is formed by injection molding of a resin material integrally with the casing of the heat exchanger. For this reason, a uniform gap cannot be formed between the tip of the flow path rib and the flat heater surface due to heat shrinkage or molding warpage during the molding of the casing. Thereby, at the time of heat exchange, since washing water flows as a leak flow through a non-uniform gap, temperature unevenness occurs on the surface of the flat heater. In addition, when the leakage flow increases, the direction of the leakage flow flows in a direction perpendicular to the main flow path direction, so bubbles generated in the main flow path do not flow out along the main flow path, and flow obstructions in the flow path. May remain. And since the bubble which generate | occur | produced in the main flow path becomes an obstacle of heat transfer, it will result in the temperature of the surface of the heater of the part in which a bubble exists overheating. For these reasons, there has been a problem that scale is generated and adhered to a portion of the flat heater where the temperature is locally generated and the operation of the heat exchanger becomes unstable. The scale means a component in which components such as calcium and magnesium contained in cleaning water such as tap water are deposited and deposited as oxides, carbonates and the like, and the same applies to the following.

In particular, in a water quality area with high hardness, the amount of scale attached to the surface of the flat heater increases, so the difference in surface temperature of the heater increases due to the adhesion of the scale. For this reason, there are problems such as cracks in the heater due to surface temperature differences.

Japanese Patent Laid-Open No. 10-220876 (see in particular FIG. 2)

In order to solve the above problems, a heat exchanger according to the present invention includes a first flow path forming member and a second flow path forming member having a water inlet and a water outlet, and having a channel rib on at least one inner wall surface. A flat plate heater enclosed in the casing, a flow path rib, a concave main flow path formed by the flat plate heater, an upper surface of the flow path rib, and a flat plate heater A leakage channel formed by a gap with the surface, and the gap of the leakage channel is 0.05 mm to 0.15 mm.

Thereby, it is possible to prevent the local boiling of the cleaning water on the surface of the flat heater and to suppress the difference in the heater surface temperature. As a result, a heat exchanger having stable heat exchange performance and scale resistance can be realized.

Moreover, the sanitary washing apparatus of the present invention includes the heat exchanger. Thereby, it is possible to realize a sanitary washing apparatus equipped with a heat exchanger having a small size and stable heat exchange performance and scale resistance and having a long life.

Moreover, the manufacturing method of the heat exchanger of the present invention includes a fixing step of fixing the first flow path forming member to the welding jig, an insertion step of inserting the spacer jig into the inner wall surface of the first flow path forming member, A mounting step of mounting on the first flow path forming member so as to enclose the spacer jig on the inner wall surface of the second flow path forming member. Further, the flow path rib provided on the inner wall surface of at least one of the first flow path forming member and the second flow path forming member is deformed by pressure contact with the spacer jig, and the first flow path forming member and the second flow path member are deformed. A welding step of welding the path forming member to form a casing, a step of removing the spacer jig from the casing, and a sealing step of inserting a heater at the position of the removed spacer jig and sealing the casing.

Thereby, it is possible to prevent the local boiling of the cleaning water on the surface of the flat heater and to suppress the difference in the heater surface temperature. As a result, a heat exchanger having stable heat exchange performance and heat exchange efficiency excellent in scale resistance can be produced.

Moreover, the sanitary washing device of the present invention includes a heat exchanger manufactured by the above heat exchanger manufacturing method. As a result, a sanitary washing apparatus having a heat exchanger having a small size and a stable heat exchange performance, excellent scale resistance, and a long-life heat exchanger can be produced.

FIG. 1 is an external perspective view showing a sanitary washing apparatus including a heat exchanger according to an embodiment of the present invention. FIG. 2 is a front view showing an external configuration of the heat exchanger according to the embodiment of the present invention. FIG. 3 is a right side view of the heat exchanger shown in FIG. 4 is a cross-sectional view of the heat exchanger shown in FIG. 2 taken along line 4-4. FIG. 5 is an enlarged cross-sectional view of a part A in FIG. FIG. 6 is an exploded perspective view of the heat exchanger shown in FIG. FIG. 7 is a plan view showing an example of a print pattern of a heating resistor formed on the flat heater of the heat exchanger shown in FIG. FIG. 8 is a plan view showing another example of the print pattern of the heating resistor formed on the flat heater of the heat exchanger shown in FIG. FIG. 9 is a perspective view of a second flow path forming member of the heat exchanger shown in FIG. FIG. 10 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 14 mm and the rib height H1 is 1.9 mm. FIG. 11 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 7 mm and the rib height H1 is 1.9 mm. FIG. 12 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 3.5 mm and the rib height H1 is 1.9 mm. FIG. 13 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 3.5 mm and the rib height H1 is 0.95 mm. FIG. 14 is a graph showing the relationship between the gap Hc and the heater wire temperature of the flat heater in an actual heat exchanger. FIG. 15 is a diagram showing the relationship between the gap Hc and the average heat transfer coefficient of the heat exchanger evaluated from the heater wire temperature shown in FIG. 14 in an actual heat exchanger. FIG. 16 is a flowchart illustrating an example of a method for manufacturing a heat exchanger according to an embodiment of the present invention. FIG. 17 is a perspective view showing an example of the shape of the channel rib of the heat exchanger according to the embodiment of the present invention. 18 is an enlarged perspective view of a portion B shown in FIG. FIG. 19 is a perspective view showing another example of the shape of the channel rib of the heat exchanger according to the embodiment of the present invention. FIG. 20 is a perspective view showing still another example of the shape of the channel rib of the heat exchanger according to the embodiment of the present invention. FIG. 21 is a sectional view taken along line 4-4 of the heat exchanger of another example shown in FIG.

Hereinafter, a heat exchanger according to an embodiment of the present invention will be described using an example applied to a sanitary washing device with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment)
Hereinafter, a heat exchanger according to an embodiment of the present invention and a sanitary washing apparatus including the heat exchanger will be described with reference to FIG.

FIG. 1 is an external perspective view showing a sanitary washing apparatus including a heat exchanger according to an embodiment of the present invention.

As shown in FIG. 1, the sanitary washing device 1 according to the present embodiment includes at least a main body 3, a toilet seat 4, a toilet lid 5, an operation unit 6, and the like, and is disposed on the upper surface of the toilet 2. . The main body 3 is disposed on the rear side of the toilet seat 4 (back side as viewed from the seated user). And the main-body part 3 is in the horizontally long and hollow housing | casing 3a, the washing | cleaning unit which is not shown in figure, the drying unit, the control unit which controls these operation | movement, and the heat exchanger 10 of this Embodiment (illustrated with a broken line) And so on. The heat exchanger 10 has a function of internally warming tap water (fluid, liquid, washing water) introduced from the water supply facility attached to the building where the toilet 2 is installed to an appropriate temperature.

Then, in the sanitary washing device 1 of the present embodiment, when the user operates the operation unit 6 to perform a predetermined input, the washing unit is driven and the nozzle of the washing unit has a shower-like shape with respect to the human body part. The washing water is jetted.

Hereinafter, the heat exchanger incorporated in the sanitary washing apparatus of the present embodiment will be described with reference to FIGS.

FIG. 2 is a front view showing an external configuration of the heat exchanger according to the embodiment of the present invention. FIG. 3 is a right side view of the heat exchanger shown in FIG. 4 is a cross-sectional view of the heat exchanger shown in FIG. 2 taken along line 4-4. FIG. 5 is an enlarged cross-sectional view of a part A in FIG. FIG. 6 is an exploded perspective view of the heat exchanger shown in FIG.

In the following description, the heat exchanger 10 shown in FIG. 4 has one surface (hereinafter referred to as “first heat transfer surface”) 20 a and the other surface (hereinafter referred to as “second heat transfer surface”) of the flat heater 20. ")" Will be described in a state where 20b is placed vertically so as to be parallel to the vertical direction, but it is needless to say that the present invention is not limited to this. Further, as shown in FIG. 2, the vertical direction is the Z direction, the direction perpendicular to the Z direction and parallel to the first heat transfer surface 20a and the second heat transfer surface 20b of the flat heater 20 is the X direction, and FIG. As shown, a direction perpendicular to both the Z direction and the X direction (direction perpendicular to the first heat transfer surface 20a) will be described as the Y direction.

As shown in FIG. 3, the heat exchanger 10 of the present embodiment has a small thickness dimension (Y direction), and has a substantially rectangular (including rectangular) plate-like appearance in front view as shown in FIG. It is composed of shapes.

In addition, the heat exchanger 10 includes, for example, a rectangular flat plate heater 20, a first flow path forming member 21, and a second flow path forming member 22 in a casing 23 having a water inlet 23 a and a water outlet 23 b. It is configured to store. The flat heater 20 is made of, for example, ceramic. Moreover, the 1st flow path formation member 21 and the 2nd flow path formation member 22 are comprised by the product made from the reinforced ABS resin which compounded the glass fiber in ABS resin, for example.

And as shown in FIG. 4, the 1st flow-path formation member 21 is arrange | positioned facing the 1st heat-transfer surface 20a of the flat heater 20. As shown in FIG. The second flow path forming member 22 is disposed to face the second heat transfer surface 20 b of the flat heater 20.

As shown in FIGS. 4 to 6, the first flow path forming member 21 includes a rectangular flat plate-like base portion 30 that faces the first heat transfer surface 20 a of the flat plate heater 20, and a flat plate shape of the base portion 30. A plurality of first flow path ribs 31a formed on a surface (hereinafter referred to as “first base surface”) 30a facing the first heat transfer surface 20a of the heater 20 is provided. Similarly, the second flow path forming member 22 includes a rectangular flat plate-like base portion 40 facing the second heat transfer surface 20 b of the flat plate heater 20 and a second heat transfer surface 20 b of the flat plate heater 20 of the base portion 40. Is provided with a plurality of second flow path ribs 31b formed on a surface 40a (hereinafter referred to as "second base surface"). In addition, the 1st flow path rib 31a and the 2nd flow path rib 31b are comprised from the base 44 and the front-end | tip part 45, for example.

The inlet channel 25a connected to the water inlet 23a by the first channel rib 31a of the first channel forming member 21, the second channel rib 31b of the second channel forming member 22, and the flat heater 20. For example, a concave main flow path 25 that snakes and flows through the liquid is formed in the flow path 25b that is connected to the water outlet 23b.

Further, as shown in FIG. 5, the upper surface of the front end portion 45 of the first flow path rib 31 a of the first flow path forming member 21 and the upper surface of the front end portion 45 of the second flow path rib 31 b of the second flow path forming member 22. And a clearance (clearance) Hc of about 0.1 mm, for example, is provided between the first heat transfer surface 20a and the second heat transfer surface 20b of the flat heater 20. As a result, a leakage channel 41 through which the liquid flows across the adjacent main channels 25 is formed. At this time, the gap Hc forming the leakage channel 41 is preferably provided substantially uniformly (including uniform) in the range of 0.05 mm to 0.15 mm as described below.

Further, as shown in FIG. 4, the peripheral portion of the base portion 30 of the first flow path forming member 21 is a wall-like shape extending by a predetermined dimension toward the direction close to the second flow path forming member 22. A flange portion 32 is provided around the flange portion 32, and an engagement groove 33 that circulates along the flange portion 32 is formed at the distal end portion of the flange portion 32.

On the other hand, a wall-shaped flange portion 42 extending around a predetermined dimension in a direction away from the first flow path forming member 21 is provided around the periphery of the base portion 40 of the second flow path forming member 22. ing. An engagement protrusion 43 that is folded back toward the first flow path forming member 21 side and circulates along the flange portion 42 is formed at the tip of the flange portion 42.

As a result, the base surface 30 a of the first flow path forming member 21 faces the base surface 40 a of the second flow path forming member 22 and is externally attached to the second flow path forming member 22 so as to contain the flat heater 20. Fitted. Specifically, first, the flange portion 32 of the first flow path forming member 21 is externally fitted to the flange portion 42 of the second flow path forming member 22. At this time, the engaging protrusion 43 of the second flow path forming member 22 is fitted into the engaging groove 33 of the first flow path forming member 21. Then, the first flow path forming member 21 and the second flow path forming member 22 are fixed and the casing 23 is formed by welding the engaging protrusion 43 and the engaging groove 33 by, for example, ultrasonic welding. . As a result, the first flow path forming member 21 and the second flow path forming member 22 are joined in a liquid-tight manner, and the main flow path 25 and the leakage flow path 41 are formed by the flat heater 20 sandwiched between them. The

As shown in FIGS. 2 and 3, a liquid such as tap water is provided in the heat exchanger 10 from a water inlet 23 a provided at the lower end of the casing 23 in the X direction and connected to an external water supply facility. Inflow. The liquid that flows in from the water inlet 23a of the casing 23 mainly passes through the concave main channel 25 provided to meander. At the same time, the gap between the main flow paths 25 via the leak flow paths 41 formed by the gaps Hc between the upper surfaces of the tips 45 of the first flow path ribs 31a and the second flow path ribs 31b and the flat plate heater 20 is simultaneously achieved. Part of the liquid passing through Then, while the liquid flowing through the main flow path 25 and the leakage flow path 41 passes from the inlet side flow path 25a to the outlet side flow path 25b, it is heated to an appropriate temperature by the flat heater 20 and flows out from the water outlet 23b. Thereby, the liquid heated to appropriate temperature is supplied to the washing | cleaning unit of the sanitary washing apparatus 1, and it sprays in a shower form from the nozzle of a washing | cleaning unit, and wash | cleans a human body part.

As described above, the heat exchanger according to the present embodiment and the sanitary washing apparatus including the heat exchanger are configured.

That is, according to the heat exchanger 10 of the present embodiment, the first flow path rib 31a and the second flow path rib 31b and the surface of the flat heater 20 (the first heat transfer surface 20a and the second heat transfer surface 20b). As a result, a concave main channel 25 in which the liquid meanders and flows is formed. Furthermore, the upper surface of the front end portion 45 of the first flow path rib 31a, the upper surface of the front end portion 45 of the second flow path rib 31b, and the surface of the flat heater 20 (the first heat transfer surface 20a and the second heat transfer surface 20b) A leak channel 41 having a uniform predetermined gap Hc is formed between the two. As a result, the liquid can be passed through the main flow path 25 to suppress the leakage flow to the leakage flow path 41, thereby suppressing the temperature unevenness and heating. As a result, the occurrence of local boiling on the surface of the flat heater 20 can be suppressed, and the surface temperature of the flat heater 20 can be reduced. And the heat exchanger 10 excellent in the stable heat exchange performance and scale resistance is realizable.

Moreover, according to the sanitary washing apparatus 1 provided with the heat exchanger 10 of the present embodiment, the heat exchanger 10 is small and stable, has excellent heat exchange performance and scale resistance, and has a long life. Thus, the sanitary washing device 1 that can be easily installed in a narrow toilet space can be realized. Furthermore, by preventing the generation and adhesion of the scale in the heat exchanger 10, it is possible to prevent the cleaning nozzle from being clogged with debris of the scale. As a result, the sanitary washing device 1 that can be used for a long period of time can be realized particularly in hard water areas.

Hereinafter, the configuration and operation of the flat heater of the heat exchanger according to the present embodiment will be described in detail with reference to FIG.

FIG. 7 is a plan view showing an example of a print pattern of the heating resistor formed on the flat heater of the heat exchanger shown in FIG.

As shown in FIG. 7, the flat heater 20 includes a ceramic base 20 k made of, for example, aluminum oxide (Al ₂ O ₃ ), and is composed of a ceramic heater formed by sandwiching a heating resistor. The heating resistor is configured by a printing pattern 20p having a predetermined heater line width 20s formed by printing a paste containing tungsten, molybdenum, manganese, or the like. Further, in FIG. 7, in order to help understanding, a heating resistor is formed on one ceramic base 20k, and the other ceramic base is omitted. The same applies to the subsequent drawings.

At this time, the printed pattern 20p constituting the heater wire of the heating resistor is such that the heater wire width 20s is narrow in the portion of the flat heater 20 on the side near the water inlet 23a of the heat exchanger 10 and the side near the water outlet 23b. In the portion of the flat heater 20, the heater line width 20s is configured to gradually increase, for example.

That is, by reducing the heater line width 20s of the printed pattern 20p constituting the heater wire of the heating resistor toward the side closer to the water inlet 23a of the flat heater 20 (for example, the lower side in FIG. 2), the heating resistor is formed. The resistance value is increased to increase the heat generation density. On the other hand, by increasing the heater line width 20s of the printed pattern 20p toward the side closer to the water outlet 23b (for example, the upper side in FIG. 2), the resistance value of the heating resistor is lowered and the heating density is lowered. That is, the flat heater 20 is a portion where the heat generation density of the portion facing the outlet-side channel 25b near the water outlet 23b of the heat exchanger 10 faces the inlet-side channel 25a near the inlet 23a. It is configured to be lower than the heat generation density.

As a result, the liquid flowing in from the water inlet 23a of the casing 23 is heated by the first heat transfer surface 20a and the second heat transfer surface 20b of the flat heater 20 while flowing through the main flow path 25 and the leak flow path 41, and is discharged. As the temperature approaches the water port 23b, the temperature of the liquid gradually increases. At this time, the surface temperature of the flat heater 20 facing the main flow path 25 (side close to the inlet flow path 25a) close to the inlet flow path 25a and the leakage flow path 41 is high in heat generation density of the flat heater 20. Tries to reach a high temperature. However, a large amount of heat from the flat heater 20 is taken away by the unheated low-temperature liquid flowing from the water inlet 23a of the casing 23. That is, since the value of the subcool (cooling degree with respect to the boiling temperature of water) is large and close to the inlet-side flow path 25a, the thickness of the temperature boundary layer is thin, and the heat transfer coefficient transferred from the flat heater 20 to the liquid is low. Get higher. Therefore, even if the heat generation density of the portion facing the inlet-side flow path 25a on the side close to the water inlet 23a of the heat exchanger 10 is increased, the temperature does not become high enough to cause local boiling.

On the other hand, the surface temperature of the flat heater 20 facing the main flow path 25 (side close to the outlet side flow path 25b) on the side close to the water outlet 23b of the casing 23 and the leak flow path 41 is higher than that on the side close to the water inlet 23a. High temperature. The reason is that the liquid contacting the first heat transfer surface 20 a and the second heat transfer surface 20 b of the flat heater 20 is already heated while flowing through the heat exchanger 10. For this reason, less heat is taken away from the surface of the flat heater 20 by the liquid. That is, the subcool value is reduced. However, in the flat heater 20, the heat generation density on the side close to the water outlet 23b is made smaller than the heat generation density on the inlet side flow path 25a side near the water inlet 23a. Therefore, the temperature of the liquid flowing through the outlet-side flow path 25b on the side close to the water outlet 23b of the heat exchanger 10 does not become high enough to cause a local boiling phenomenon.

Thereby, even at the boundary surface between the flat heater 20 on the side close to the water outlet 23b where the temperature of the liquid becomes high and the liquid such as water, it is suppressed that the temperature becomes high enough to cause a local boiling phenomenon. As a result, it is possible to prevent the generation and adhesion of scale to the surface of the flat heater 20, and to realize a long-life and highly reliable heat exchanger 10. For this reason, a ceramic heater that has excellent characteristics of corrosion resistance and a small heat capacity as compared with metal, but is easily cracked, can be used for the flat heater 20. Furthermore, cracking of the ceramic heater due to the temperature difference can be prevented, and the long-life and highly reliable heat exchanger 10 can be realized.

In addition, when the heat generation density of the heat transfer surface of a normal flat heater is uniform, the side close to the water outlet of the flat heater becomes the maximum temperature. Therefore, in a normal flat heater, when the temperature of the heat transfer surface exceeds 100 ° C. and the liquid enters the nucleate boiling heat transfer state, there is a possibility that scale is generated in the nucleate boiling heat transfer portion. .

Moreover, by providing the main flow path 25 and the leakage flow path 41 on both surfaces of the flat heater 20, the water flowing through the heat of the flat heater 20 in contact with the first and second heat transfer surfaces 20a and 20b on the front and back sides. Heat can be transferred to liquids such as water. Thereby, heat exchange with high thermal efficiency with almost no heat dissipation loss can be performed. Further, by utilizing the first and second heat transfer surfaces 20a and 20b on the front and back of the flat heater 20 as heat transfer surfaces, a smaller and more compact heat exchanger 10 can be realized.

Hereinafter, the configuration and operation according to another example of the flat heater of the heat exchanger according to the present embodiment will be described in detail with reference to FIG.

FIG. 8 is a plan view showing another example of the print pattern of the heating resistor formed on the flat heater of the heat exchanger shown in FIG. In addition, since the structure of the flat heater 20 is the same as FIG. 7, description is abbreviate | omitted.

That is, in the heating resistor printed pattern 20p shown in FIG. 8, the adjacent heater line interval 20h is narrow in the portion near the water inlet 23a of the flat heater 20, and the heater line interval is close to the outlet 23b. It differs from the flat heater 20 shown in FIG. 7 in that 20h is widened.

That is, the heater wire interval 20h of the printed pattern 20p having a uniform width constituting the heater wire of the heating resistor is the side closer to the water inlet 23a of the heat exchanger 10 of the flat heater 20 (for example, the lower side in FIG. 2). By making it so narrow, the heat generation density of the heating resistor is increased. On the other hand, by increasing the heater line interval 20h of the printed pattern 20p toward the side closer to the water outlet 23b (for example, the upper side in FIG. 2), the heat generation density of the heating resistor is lowered.

As a result, as in the case where the heating line width is changed by changing the heater line width 20s described above, scale generation and adhesion can be prevented, and cracking of the ceramic heater can be prevented to achieve long life and high reliability heat exchange. Can be realized.

Hereinafter, the effect of the leakage flow path of the heat exchanger according to the present embodiment will be described with reference to FIGS. 9 to 15.

First, the relationship between the flow rate (Qmain) flowing through the main channel 25 in the heat exchanger 10 of the present embodiment and the flow rate (Qleak) flowing through the leak channel 41 is changed by changing the gap Hc of the leak channel 41. Simulated.

In addition, the said simulation is performed about the case where the flow rate of 500 cc / min is flowed in the heat exchanger by the structure which changed the combination of the shape parameter shown in FIG. 9 with four types. Hereinafter, the main flow path 25 and the leakage flow path 41 formed by the second flow path ribs 31b of the second flow path forming member 22 will be described as an example, but the first flow path of the first flow path forming member 21 will be described. It goes without saying that the same applies to the main flow path 25 and the leakage flow path 41 formed by the ribs 31a.

Specifically, as shown in FIG. 9, the combination of the rib pitch P of the second flow path rib 31b of the second flow path forming member 22 forming the main flow path 25 and the rib height H1 of the second flow path rib 31b. The simulation was changed. The results are shown in FIGS.

FIG. 10 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 14 mm and the rib height H1 is 1.9 mm. FIG. 11 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 7 mm and the rib height H1 is 1.9 mm. FIG. 12 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 3.5 mm and the rib height H1 is 1.9 mm. FIG. 13 is a graph showing a result of simulating the influence of the gap Hc when the rib pitch P is 3.5 mm and the rib height H1 is 0.95 mm.

In the case of FIG. 10, the flow rate of the main flow path 25 that is a flow rate range that is normally used is 0.16 m / sec, in the case of FIG. 11, the flow rate is 0.32 m / sec, and in the case of FIG. In the case of FIG. 13 at 64 m / sec, the flow velocity corresponds to 1.25 m / sec.

From the simulation results shown in FIGS. 10 to 13, the influence of the flow rate of the leakage flow channel 41 on the change of the gap Hc on the flow rate of the main flow channel 25 as the cross-sectional area of the main flow channel 25 decreases and the flow velocity increases. It turns out that becomes large.

That is, within the range of the above parameters, in order to set the flow rate of the leakage flow path 41 to a total flow rate of 500 cc / min, for example, 10 cc, 50 cc / min or less, the gap Hc is in the range of 0.05 mm to 0.15 mm. It turns out that it should just set to. The reason is that if the flow rate flowing through the leakage flow path 41 is set to 50 cc / min or less, the flow of the main flow path 25 that mainly contributes to forced convection heat transfer becomes dominant. Therefore, the surface temperature of the flat heater 20 can be lowered, and bubbles generated in the flow path can be effectively eliminated by the flow of the main flow path 25.

Hereinafter, based on the results of the above simulation, the results of examination of the influence of the gap Hc from the heater wire temperature and the average heat transfer coefficient with an actual heat exchanger are shown in FIGS.

FIG. 14 is a graph showing the relationship between the gap Hc and the heater wire temperature of the flat heater in an actual heat exchanger. At this time, as a shape parameter of the heat exchanger 10, a heat exchanger was used in which the rib pitch P of the second flow path rib 31b was set to 7 mm and the rib height H1 of the second flow path rib 31b was set to 1.9 mm.

Then, the heater wire temperature when the incoming water temperature was 5 ° C. and a flow rate of 500 cc / min was passed through the heat exchanger 10 having the above configuration was measured.

In addition, in order to grasp the state of the liquid in the heat exchanger, the heat exchanger was made of a transparent material, and the state of heat exchange between the flat heater and the liquid was evaluated.

As a result, as shown in FIG. 14, it was found that when the gap Hc was reduced from about 0.2 mm to about 0.05 mm, the heater wire temperature rapidly decreased. This indicates that the liquid leakage flow rate through the leakage flow path 41 is significantly reduced in this range. This is because when the gap Hc is narrowed, the flow rate increases and the heat transfer rate to the liquid increases.

FIG. 15 is a view showing the relationship between the gap Hc in the actual heat exchanger and the average heat transfer coefficient of the heat exchanger evaluated from the heater wire temperature shown in FIG. At this time, in the drawing, in order to show the state of the liquid flowing in the heat exchanger, the ratio of forced convection heat transfer and boiling heat transfer is schematically shown.

As shown in FIG. 15, when the gap Hc is around 0.05 mm, local boiling in the heat exchanger 10 was not recognized. That is, when the gap Hc is near 0.05 mm, it is considered that heat is transmitted to the liquid by forced convection heat transfer in almost the entire region. As a result, it is considered that a stable hot water operation is performed from the water outlet 23b of the heat exchanger 10.

In addition, when the gap Hc is around 0.15 mm, local boiling is partially observed in the heat exchanger 10, and boiling heat transfer occurs in addition to forced convection heat transfer. However, normally, when the ratio of boiling heat transfer to forced convection heat transfer is small, the generation of bubbles such as water vapor is suppressed, and the generated bubbles are also easily carried out by forced convection, so the outlet of the heat exchanger 10 The hot water operation from 23b is stable. Therefore, stable hot water can be discharged from the water outlet 23b of the heat exchanger 10 even in a state where some boiling heat transfer has occurred.

On the other hand, as shown in FIG. 15, when the gap Hc is around 0.3 mm, boiling occurs in the heat exchanger 10, and when the ratio of boiling heat transfer to forced convection heat transfer is large, the influence of boiling heat transfer Becomes larger. Therefore, the flow of the liquid in the heat exchanger 10 becomes unstable because, for example, bubbles such as water vapor are generated and the generated bubbles are not easily carried out by forced convection.

That is, as shown in FIGS. 14 and 15, if the gap Hc of the leakage flow path 41 between the upper surface of the tip 45 of the second flow path rib 31 b and the flat heater 20 changes, the heater wire temperature and heat transfer The state of changes. Therefore, by setting the gap Hc to 0.15 mm or less, preferably about 0.05 mm to 0.1 mm, stable hot water can be discharged from the heat exchanger 10. Thereby, the heat exchanger 10 excellent in stable heat exchange performance and scale resistance and the sanitary washing device 1 including the heat exchanger 10 can be realized.

However, conventionally, the first flow path forming member 21 and the second flow path forming member 22, which are resin molded products constituting the outer casing 23 of the heat exchanger, cause warpage during molding or ultrasonic welding. Welding dimensions vary. Therefore, conventionally, the clearance Hc between the upper surface of the tip 45 of the first flow path rib 31a and the second flow path rib 31b and the flat heater 20 is 0.05 mm to 0.15 mm, preferably 0.05 mm to 0.1 mm. Difficult to set.

Therefore, a method of manufacturing a heat exchanger that realizes the gap Hc will be described below with reference to FIGS. 4 and 6 and FIG.

FIG. 16 is a flowchart for explaining an example of a method for manufacturing a heat exchanger according to an embodiment of the present invention.

As shown in FIG. 16, first, the first flow path forming member 21 having the first flow path ribs 31a formed by injection molding of a resin such as ABS resin on the inner wall surface is attached to an ultrasonic welding jig and fixed. (Step S10). At this time, the first flow path rib 31 a includes a base portion 44 and a tip portion 45, and the cross-sectional width of the tip portion 45 is smaller than the cross-sectional width of the base portion 44. The first flow path ribs 31a before welding have a predetermined rib pitch P and a predetermined rib height H1 before welding, and are alternately formed so as to form a meandering main flow path 25. Note that the rib height H1 of the first flow path rib 31a before welding is higher than the finally formed gap Hc, for example, a dimension that contacts the flat plate heater 20 to be inserted.

Next, a spacer jig made of a metal material such as stainless steel is disposed or inserted so as to cover the first flow path rib 31a of the first flow path forming member 21 (step S20). At this time, the spacer jig has a thickness Hc between the upper surface of the tip 45 of the first flow path rib 31a and the second flow path rib 31b and the flat heater 20 to the thickness of the flat heater 20 to be inserted later. (For example, 0.1 mm).

Next, the second flow path rib 31b of the second flow path forming member 22 having the second flow path rib 31b formed by injection molding of a resin such as ABS resin on the inner wall surface is provided on the first flow path forming member 21. A spacer jig disposed on the first flow path rib 31a side is mounted so as to be included (step S30).

Next, in the state described above, the ultrasonic welder is mounted, and from the base surface 30a of the first flow path forming member 21 and the base surface 40a side of the second flow path forming member 22, via an ultrasonic jig, Apply ultrasonic vibration. Thereby, the engagement groove 33 of the flange portion 32 of the first flow path forming member 21 and the engagement protrusion 43 of the flange portion 42 of the second flow path forming member 22 are welded (step S40). And the casing 23 is formed.

At this time, the first flow path rib 31a of the first flow path forming member 21 and the second flow path rib 31b of the second flow path forming member 22 that are in contact with the spacer jig are subjected to ultrasonic vibration during ultrasonic welding. Due to the generated heat, for example, the tip of the tip 45 is deformed along the spacer jig. That is, the distance between the first flow path rib 31a of the first flow path forming member 21 and the second flow path rib 31b of the second flow path forming member 22 which are opposed to each other is deformed to be the thickness of the spacer jig. Thereby, the dimensional variation of the 1st flow path formation member 21 and the 2nd flow path formation member 22 which comprise a casing, a shaping | molding curvature, etc. are absorbed, and it forms at a uniform space | interval.

Next, the spacer jig is removed from the formed casing (step S50). As a result, a casing in which the distance between the first flow path rib 31a of the first flow path forming member 21 and the second flow path rib 31b of the second flow path forming member 22 is formed uniformly is produced.

Next, the flat heater 20 is inserted into the position of the spacer jig from which the casing is removed, and the side surface of the flat heater 20 and the casing are sealed in a liquid-tight manner with a sealant such as a silicone sealant (for example). Step S60). Accordingly, the first flow path rib 31a and the second flow path rib 31b and the surface of the flat heater 20 (the first heat transfer surface 20a and the second heat transfer surface 20b) have a concave shape in which the liquid flows in a meandering manner. Main flow path 25 is formed. Furthermore, the upper surface of the front end portion 45 of the first flow path rib 31a, the upper surface of the front end portion 45 of the second flow path rib 31b, and the surface of the flat heater 20 (first heat transfer surface and second heat transfer surface). A leakage channel 41 having a predetermined gap Hc (for example, 0.1 mm) is formed therebetween. In other words, the leakage jig 41 having a predetermined gap Hc of 0.05 to 0.15 mm as a target can be formed with high accuracy by the spacer jig. At this time, the sealing performance of the manufactured heat exchanger 10 may be inspected, for example, a liquid leakage inspection may be performed (step S70).

Thus, the heat exchanger of the present embodiment is manufactured.

That is, in the heat exchanger manufacturing method of the present embodiment, the first flow path is formed on both surfaces of the spacer jig that is thicker than the thickness of the flat heater 20 by the amount corresponding to the gap Hc of the predetermined leak flow path 41. The first flow path rib 31a of the member 21 and the second flow path rib 31b of the second flow path forming member 22 are welded in a facing direction. And the front-end | tip part 45 which opposes a spacer jig | tool of the 1st flow path rib 31a and the 2nd flow path rib 31b is changed at the time of welding, and a casing is produced. At this time, the first flow path rib 31a and the second flow path rib 31b that come into contact with the spacer jig due to dimensional variations or molding warpage of the first flow path forming member 21 and the second flow path forming member 22 constituting the casing. The tip portion 45 of the metal is partially melted by heat during welding. As a result, the tip portions 45 of the first channel rib 31a and the second channel rib 31b are deformed along the spacer jig, that is, spaced apart by the thickness of the spacer jig, and an upper surface is formed on the tip portion 45. The

Then, after welding, the spacer jig is removed and the flat heater 20 is mounted. At this time, a concave main flow path that meanders on the surface of the flat heater 20 by the first flow path rib 31a of the first flow path forming member 21 and the second flow path rib 31b of the second flow path forming member 22. 25, a leakage flow path 41 having a uniform gap Hc is formed between the first flow path rib 31a and the second flow path rib 31b and the surface of the flat heater 20. As a result, a highly accurate and uniform gap Hc is formed between the upper surfaces of the front end portions 45 of the first flow path rib 31a and the second flow path rib 31b constituting the leakage flow path 41 and the surface of the flat heater 20. Is done.

As a result, the occurrence of local boiling on the surface of the flat heater 20 can be suppressed, and the surface temperature of the flat heater 20 can be lowered, and the heat exchanger 10 has stable heat exchange performance and excellent scale resistance. Can be produced.

Further, in the heat exchanger manufacturing method of the present embodiment, the first flow path rib 31 a and the second flow path rib 31 b are composed of the base portion 44 and the tip portion 45, and the tip portion 45 has a cross-sectional width wider than that of the base portion 44. It is small. Thereby, only the front-end | tip part 45 with a small cross-sectional width melt | dissolves and deform | transforms at the time of the ultrasonic welding at the time of producing the casing 23, without breaking the base 44 with a large cross-sectional width. As a result, the first channel rib 31a and the second channel rib 31b can be molded smoothly and stably. And the heat exchanger 10 of the stable quality can be produced.

In addition, in the manufacturing method of the said heat exchanger, it demonstrated by the structure where the front-end | tip part 45 of the 1st flow path rib 31a and the 2nd flow path rib 31b has a cross-sectional width smaller than the base 44. Below, the specific shape of the 1st flow path rib 31a and the 2nd flow path rib 31b is demonstrated using FIGS. 17-20.

FIG. 17 is a perspective view showing an example of the shape of the first flow path rib and the second flow path rib of the heat exchanger. 18 is an enlarged perspective view of a portion B in FIG. FIG. 19 is a perspective view showing another example of the shape of the first flow path rib and the second flow path rib of the heat exchanger. FIG. 20 is a perspective view showing still another example of the shape of the first flow path rib and the second flow path rib of the heat exchanger. In the following, the second flow path rib 31b is shown as an example, but it goes without saying that the first flow path rib 31a is the same.

First, as shown in FIGS. 17 and 18, the second flow path rib 31 b is composed of a tip portion 45 and a base portion 44. The base portion 44 is formed in a rectangular shape in cross section, and the tip portion 45 has a substantially triangular edge in cross section. It is formed in a shape (including a triangular edge shape). At this time, the width of the bottom surface of the distal end portion 45 is configured to be smaller than the width of the base portion 44.

Further, as shown in FIG. 19, the second flow path rib 31 b is composed of a tip portion 45 and a base portion 44, and has a shape in which the width of the connection portion between the tip portion 45 and the base portion 44 is equal. And the front-end | tip part 45 is formed in the cross section by the right triangle.

Further, as shown in FIG. 20, the second flow path rib 31b is composed of a tip portion 45 and a base portion 44, and the tip portion 45 and the base portion 44 are formed in a shape that forms, for example, a right triangle or a part of a triangle. Has been.

These shapes allow the tip portions 45 of the first flow path rib 31a and the second flow path rib 31b to be easily deformed during ultrasonic welding. Further, at the time of ultrasonic welding, it is possible to easily adjust the heights of the tip portions 45 of the first channel rib 31a and the second channel rib 31b. As a result, for example, an upper surface is formed at the tip 45 shown in FIG. 4, and a predetermined gap Hc can be formed uniformly with the flat heater 20.

In the present embodiment, the casing 23 is described as an example in which the first flow path forming member 21 and the second flow path forming member 22 are formed by ultrasonic welding. However, the present invention is not limited to this. For example, you may form by the heat welding which heats and welds. In this case, during the heat welding operation, for example, between the first channel rib 31a of the first channel forming member 21 and the second channel rib 31b of the second channel forming member 22, for example, the first channel rib 31a and The casing 23 is thermally welded in a state where a spacer jig heated to a temperature at which the tip 45 of the second flow path rib 31b is thermally deformed and not melted is inserted. Thereby, the front-end | tip parts 45 of the 1st flow path rib 31a and the 2nd flow path rib 31b which contact | abut to the heated spacer jig | tool are partially thermally deformed with the heat | fever of a spacer jig | tool. As a result, it is possible to absorb the molding warp and dimensional variations and obtain the same effects as ultrasonic welding.

In the heat exchanger and the manufacturing method thereof according to the present embodiment, the first flow path forming member 21 is provided with the first flow path rib 31a and the second flow path forming member 22 is provided with the second flow path rib 31b. Although the example which formed 25 and the leakage flow path 41 was demonstrated, it is not restricted to this. The structure which provided the flow path rib in any one of the 1st flow path formation member 21 or the 2nd flow path formation member 22 may be sufficient. For example, as shown in FIG. 21, the first channel forming member 21 is provided with channel ribs 31 to form the main channel 25 and the leakage channel 41, and the second channel forming member 22 is provided with channel ribs. There may be no configuration. In this case, it is preferable that the flat heater 20 is provided with a heating resistor on a surface facing the base surface 30 a of the first flow path forming member 21 including the flow path ribs 31. Thereby, the liquid is allowed to flow uniformly through the main flow path 25 and the leakage flow path 41, the occurrence of local boiling on the surface of the flat heater 20 is suppressed, and the surface temperature of the flat heater 20 is lowered. it can. As a result, a more compact and compact heat exchanger 10 having excellent stable heat exchange performance and scale resistance can be realized.

Also, by providing the heat exchanger 10, the sanitary washing device 1 can be realized that has excellent heat exchange performance and scale resistance, has a long life, is small, and can be easily installed in a narrow toilet space.

As described above, the heat exchanger according to the present invention has a water inlet and a water outlet, and includes a first flow path forming member and a second flow path forming member having flow path ribs on at least one inner wall surface. A flat plate heater included in the casing, a flow path rib, a concave main flow path formed by the flat plate heater, an upper surface of the flow path rib, and a surface of the flat plate heater And a leak channel formed by a gap between the leak channel and the leak channel is 0.05 mm to 0.15 mm.

Thereby, it is possible to prevent the local boiling of the cleaning water on the surface of the flat heater and to suppress the difference in the heater surface temperature. As a result, it is possible to realize a heat exchanger with stable heat exchange performance and heat exchange efficiency with excellent scale resistance.

Further, according to the heat exchanger of the present invention, the first flow path rib and the second flow path rib are configured by the base portion and the tip portion, and the tip portion has a configuration having a smaller cross-sectional width than the base portion.

This makes it possible to configure the gaps of the leakage flow path more uniformly. As a result, the occurrence of local boiling of cleaning water on the surface of the flat heater and the occurrence of a heater surface temperature difference can be more efficiently suppressed.

Further, according to the heat exchanger of the present invention, the heat generation density facing the flow path space near the water outlet of the flat heater is smaller than the heat generation density facing the flow path space near the water inlet. Have.

This makes it possible to efficiently transfer the heat of the flat heater to the washing water that flows in contact with the heat transfer surface of the flat heater, thereby reducing waste of heat dissipation. As a result, it is possible to realize a heat exchanger that has high heat exchange efficiency, is small and compact, and can suppress adhesion of scale.

According to the heat exchanger of the present invention, the flat heater includes a ceramic base, a heating resistor formed of a resistor formed on the ceramic base with a print pattern having a predetermined heater line width, and an electrode. It consists of a ceramic heater.

Furthermore, according to the heat exchanger of the present invention, the heater line width of the printing pattern of the flat heater has a configuration in which the portion closer to the water outlet is thicker than the portion closer to the water inlet.

These configurations make it possible to realize a ceramic heater capable of adjusting the amount of heat generation because the electric resistance when a current is passed decreases as the heater line width of the printed pattern, which is a heating resistor, increases. That is, it is possible to increase the amount of heat generated in the portion facing the channel space on the channel side near the water inlet where the heater line width of the print pattern is narrow, that is, increase the heat generation density. On the other hand, the amount of heat generated in the portion facing the flow path space on the side close to the water outlet where the heater line width of the printed pattern is large can be reduced, that is, the heat generation density can be reduced.

As a result, the temperature of the flat heater is raised to a high temperature at which the liquid locally boils even at the boundary surface between the flat heater near the water outlet and the liquid such as tap water where the liquid temperature increases. This can be suppressed. As a result, scale generation and adhesion to the flat heater can be prevented, and high heat exchange efficiency can be maintained. In addition, as a flat heater, it has excellent corrosion resistance and small heat capacity compared to metal, but on the other hand, even if a ceramic heater that is easy to crack is used, cracking due to the temperature difference of the flat heater is prevented. it can. As a result, a long-life and highly reliable heat exchanger can be realized.

Further, according to the heat exchanger of the present invention, the gap between the printed pattern lines of the flat heater has a configuration in which the portion closer to the water outlet is wider than the portion closer to the water inlet.

This configuration makes it possible to increase the amount of heat generated in the portion facing the channel space on the channel side close to the water inlet where the gaps between the printed pattern lines are narrow, that is, to increase the heat generation density. On the other hand, the amount of heat generated in the portion facing the flow path space on the side close to the water outlet where the gaps between the printed pattern lines are wide can be reduced, that is, the heat generation density can be reduced.

Thus, for the same reason as described above for the heater line width, scale generation and adhesion to the flat heater can be prevented, and high heat exchange efficiency can be maintained. Furthermore, the ceramic heater can be prevented from cracking due to the heating temperature difference of the flat heater, and a long-life and highly reliable heat exchanger can be realized.

Moreover, according to the sanitary washing apparatus of the present invention, the above heat exchanger is provided.

This configuration makes it possible to reduce the size of the main body of the sanitary washing device with a heat exchanger that is small and stable, has excellent scale resistance, and has a long life. As a result, the sanitary washing device can be easily installed in a narrow toilet space. Moreover, the sanitary washing apparatus which can be used in a hard water area is realizable by preventing the production | generation and adhesion of the scale in a heat exchanger. Furthermore, the scale nozzle peeled off from the heat exchanger can be prevented from clogging the cleaning nozzle, and a long-life and highly reliable sanitary cleaning apparatus can be realized.

In addition, according to the method for manufacturing a heat exchanger of the present invention, a fixing step of fixing the first flow path forming member to the welding jig, and an insertion step of inserting the spacer jig into the inner wall surface of the first flow path forming member. And a mounting step of mounting on the first flow path forming member so as to enclose the spacer jig on the inner wall surface of the second flow path forming member. Further, the flow path rib provided on the inner wall surface of at least one of the first flow path forming member and the second flow path forming member is deformed by pressure contact with the spacer jig, and the first flow path forming member and the second flow path member are deformed. A welding step of welding the path forming member to form a casing, a step of removing the spacer jig from the casing, and a sealing step of inserting a heater at the position of the removed spacer jig and sealing the casing.

This makes it possible to form a highly accurate and uniform leak channel between the tip of the channel rib constituting the leak channel and the surface of the flat heater. As a result, it is possible to prevent the local boiling of the washing water from occurring on the surface of the flat heater and to suppress the surface temperature difference of the heater. As a result, a heat exchanger having stable heat exchange performance and excellent heat exchange efficiency with excellent scale resistance can be produced.

Moreover, according to the heat exchanger manufacturing method of the present invention, the method further includes the step of inspecting the heat exchanger for leakage. Thereby, a heat exchanger having high reliability can be manufactured over a long period of time.

Moreover, according to the method for manufacturing a heat exchanger of the present invention, the welding step is performed by ultrasonic welding. As a result, the flow path ribs that contact the spacer jig can be uniformly spaced in a short time. As a result, a stable quality heat exchanger can be easily manufactured.

Further, according to the method for manufacturing a heat exchanger of the present invention, the flow path rib is composed of a base portion and a tip portion, and the tip portion has a smaller cross-sectional width than the base portion. Thereby, only the front-end | tip part with a small cross-sectional width can be melt | dissolved and deform | transformed and molded, without the base part with a large cross-sectional width breaking at the time of welding. As a result, the flow path rib can be formed smoothly and stably during welding.

Further, according to the method for manufacturing a heat exchanger of the present invention, the tip end portion of the flow path rib has a substantially triangular edge cross-sectional shape. Thereby, the front-end | tip part of the flow path rib at the time of welding can be shape | molded more smoothly. As a result, a more stable quality heat exchanger can be easily manufactured.

Furthermore, according to the method for manufacturing a heat exchanger of the present invention, the tip end portion of the flow path rib has an acute-angle cross-sectional shape. Thereby, the height adjustment of the front-end | tip part of the flow path rib at the time of welding can be performed easily.

Moreover, according to the sanitary washing apparatus of the present invention, the heat exchanger manufactured by the above-described heat exchanger manufacturing method is provided. As a result, a sanitary washing apparatus having a heat exchanger having a small size and a stable heat exchange performance, excellent scale resistance, and a long-life heat exchanger can be produced.

The present invention is useful in a technical field including a heat exchanger and a heat exchanger that require stable heat exchange performance and scale resistance.

DESCRIPTION OF SYMBOLS 1 Sanitary washing apparatus 2 Toilet bowl 3 Main body part 3a Case 4 Toilet seat part 5 Toilet lid part 6 Operation part 10 Heat exchanger 20 Flat heater 20a First heat transfer surface 20b Second heat transfer surface 20h Heater wire interval 20k Ceramic base 20p Print pattern 20s Heater line width 21 First flow path forming member 22 Second flow path forming member 23 Casing 23a Water inlet 23b Water outlet 25 Main flow path 25a Inlet side flow path 25b Outlet side flow path 30, 40 Base portion 30a, 40a Base Surface 31 Channel rib 31a First channel rib 31b Second channel rib 32, 42 Flange portion 33 Engagement groove 41 Leakage channel 43 Engagement projection 44 Base 45 Tip

Claims (14)

1. A casing comprising a first flow path forming member and a second flow path forming member having a water inlet and a water outlet and having a channel rib on at least one inner wall surface;
   A flat heater contained in the casing;
   With
   A concave main channel formed by the channel ribs and the flat heater;
   A leakage channel formed by a gap between the upper surface of the channel rib and the surface of the flat heater,
   The heat exchanger in which the gap in the leakage channel is 0.05 mm to 0.15 mm.
2. The heat exchanger according to claim 1, wherein the flow path rib includes a base portion and a tip portion, and the tip portion has a smaller cross-sectional width than the base portion.
3. 2. The heat exchanger according to claim 1, wherein the flat plate heater has a heat generation density facing a flow path space near the water outlet smaller than a heat generation density facing a flow path space near the water inlet.
4. The said flat heater is comprised by the ceramic heater which consists of a ceramic base | substrate, the heating resistor which consists of a resistor formed in the printed pattern of the predetermined heater line width on the ceramic base | substrate, and an electrode. Heat exchanger.
5. 5. The heat exchanger according to claim 4, wherein the heater line width of the printed pattern of the flat heater is thicker in a portion closer to the water outlet than a portion close to the water inlet.
6. 5. The heat exchanger according to claim 4, wherein a gap between the printed pattern lines of the flat heater is wider at a portion closer to the water outlet than a portion near the water inlet.
7. A sanitary washing apparatus comprising the heat exchanger according to claim 1.
8. A fixing step for fixing the first flow path forming member to the welding jig;
   An insertion step of inserting a spacer jig into the inner wall surface of the first flow path forming member;
   A mounting step of mounting on the first flow path forming member so as to enclose the spacer jig on the inner wall surface of the second flow path forming member;
   The flow path rib provided on at least one inner wall surface of the first flow path forming member and the second flow path forming member is deformed by pressure contact with the spacer jig, and the first flow path forming member and the A welding step of welding the second flow path forming member to form a casing;
   Removing the spacer jig from the casing;
   Inserting a heater at the position of the removed spacer jig, sealing step to seal the casing,
   A method for manufacturing a heat exchanger.
9. The method for manufacturing a heat exchanger according to claim 8, further comprising a step of inspecting leakage of the heat exchanger.
10. The method for manufacturing a heat exchanger according to claim 8, wherein the welding step is performed by ultrasonic welding.
11. The heat exchanger manufacturing method according to claim 8, wherein the flow path rib includes a base portion and a tip portion, and the tip portion has a smaller cross-sectional width than the base portion.
12. The method of manufacturing a heat exchanger according to claim 8, wherein the flow path rib has a cross-sectional shape with a substantially triangular edge at the tip.
13. The method for manufacturing a heat exchanger according to claim 8, wherein the flow path rib has a cross-sectional shape with an acute angle at the tip.
14. The sanitary washing apparatus provided with the heat exchanger manufactured by the manufacturing method of the heat exchanger of Claim 8.

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