Thick film heating body structure

Abstract

A thick film heating body structure comprises a shell, a lower end cover, a sealing ring, a center pipe, a spring runner, a plug, a thick film heating pipe and an upper end cover, the spring runner surrounds the center pipe, the center pipe and the spring runner are integrally covered with the shell, the upper end cover and the lower end cover are assembled on the upper portion and the lower portion of the shell, and the plug is arranged between the sealing ring of the upper end cover and the center pipe. The water outlet is communicated between the upper end cover and the flow channel, a spring positioning structure is arranged, and one end of the spring is clamped into the spring positioning structure to limit the degree of freedom of the spring. According to the thick film heating body structure, the spring flow channel is clamped into the plug, and the plug is provided with the positioning groove and the positioning convex point, so that the spring flow channel is locked at a fixed position, the NTC detection site and the NTC detection time are ensured not to scale along with the heating body, the temperature of the tested outlet water is not influenced, and the temperature of the outlet water can be accurately controlled.

Description

[Technical field] The invention relates to the technical field of electric heating in drinking water and water supply equipment, in particular to the technical field of rapid heating of thick film heaters in drinking water equipment. [Background technology] The structure of the so-called thick film heater mainly includes a stainless steel layer, an inner insulating medium layer, a resistance heating layer and an outer insulating medium layer from the inside to the outside. The heat conduction distance from the resistance heating layer to the stainless steel layer is short and the thermal resistance is small. Therefore, the thick film heater has the advantages of low thermal resistance and fast thermal response speed due to its structural characteristics.

[0003] In the application of thick film heaters, it is often necessary to monitor and control the temperature of the heater in real time. Generally, the existing technical means are to set a temperature-sensitive material in contact with the surface of the heating element outside the heating element, and cooperate with a protection switch and a circuit board to control the temperature of the heating element. Once the safe temperature range is exceeded, it will be disconnected and the working state will be cut off for regulation.

[0004] Chinese utility model patent CN 220896860 U discloses a thick film heater, comprising a tube body and a thick film heating body wrapped around the tube body, a pressure relief device is provided on the openings at one end of the tube body and the thick film heating body, the pressure relief device comprises a water inlet end cover, a front end cover and an elastic resetting member, the front end cover is sealingly arranged on one end of the tube body, the water inlet end cover is sealingly arranged on one end of the thick film heating body, the elastic reset member is installed between the front end cover and the water inlet end cover, when the tube body is pressurized, the tube body can cause the elastic reset member to deform and press toward the water inlet end cover to realize the release of high-pressure gas in the tube body, and the tube body is reset to the initial state under the action of the elastic reset member.

[0005] The above-mentioned patent disclosure solves the problem of pressure relief of the inner heat pipe during the heating process of the thick film heater. After the air in the inner tube of the heating tube is heated, the pressure inside the inner heat pipe is relatively high. If the pressure cannot be relieved in time, the inner heat pipe will expand, which will cause the inner heat pipe to explode. However, during use, since the position of the reset button on the outside of the tube body is not fixed, it will move with the water flow. At the same time, if the heater is used in a place where scaling will occur, the temperature cannot be detected when the heater structure is restored, and steam will appear very frequently, resulting in inaccurate NTC detection of the inlet and outlet water temperatures, and the outlet water temperature cannot be guaranteed. [Summary of the invention] In view of the problems existing in the prior art, the present invention provides a thick film heater structure, in which a spring flow channel is inserted into a plug, and a positioning groove and a positioning protrusion are provided on the plug, so that the spring flow channel is locked in a fixed position, thereby ensuring the NTC detection position. Changes in the NTC detection time do not affect the test water temperature due to scaling of the heater, and the water outlet temperature can be accurately controlled.

[0007] The thick film heating body structure involved in the present invention comprises an outer shell, a lower end cover, a sealing ring, a central tube, a spring flow channel, a plug, a thick film heating tube and an upper end cover, wherein the spring flow channel surrounds the central tube, the thick film heating tube is sleeved on the spring flow channel, the outer shell as a whole covers the central tube, the spring flow channel and the thick film heating tube combination part, and the upper end cover and the lower end cover are assembled on the upper and lower ends of the outer shell, characterized in that: Center tube: The innermost structure of the thick film heater as the integral inner core component; Spring flow channel: The coiled sleeve is arranged on the outer surface of the center tube, and its length is based on the length that can cover the center tube; Thick film heating tube: The thick film heating tube sleeve is arranged outside the central tube and the spring flow channel. The outer wall of the central tube, the entire spring flow channel and the inner wall of the thick film heating tube together constitute a heating spiral flow channel. The thick film heating tube is provided with a film temperature thermometer and a water outlet thermometer; Shell: It wraps the internal structure as a whole and serves as the main structure for installing the upper and lower end covers; Lower end cover: has a water inlet structure, connected to the water inlet pipe, and realizes sealing and packaging with the main structure through the lower sealing ring; Upper end cover: has a water outlet structure, connected to the water outlet pipe, and realizes sealing and packaging with the main structure through the upper sealing ring; Plug: It is arranged between the sealing ring of the upper end cover and the central tube, has a water outlet connecting the upper end cover and the flow channel, and is provided with a spring positioning structure, one end of the spring is inserted into the spring positioning structure to limit the freedom of the spring.

[0008] The water outlet on the plug is opened on the circumferential surface of the plug, and the spring positioning structure is arranged beside the water outlet, which satisfies: the spring coiling direction of the spring positioning structure arranged outside the clamping end is away from the water outlet.

[0009] The spacing of the last circle of the spring is greater than the other spacings, and in the design, the spacing between the film temperature thermometer on the thick film heating tube after assembly and the upper side of the last circle of the spring is greater than or equal to 2 mm.

[0010] The plug includes an integral insertion end and a positioning end, wherein the outer diameter of the insertion end is interference fit with the inner diameter of the center tube, and the insertion end is inserted into the center tube for assembly; the positioning end faces the upper end cover, and has a positioning groove on the side facing the upper end cover.

[0011] The positioning groove includes at least two grooves, and the corresponding bottom of the upper end cover is provided with at least two positioning protrusions. The positioning protrusions of the upper end cover are inserted into the positioning groove through the sealing ring to define the position between the upper end cover and the plug.

[0012] A film temperature thermometer and a water outlet thermometer are provided on the thick film heating tube, and a film temperature thermometer and a water outlet thermometer are provided near the water outlet of the plug of the thick film heating tube, wherein the film temperature thermometer and the water outlet thermometer are arranged on the same busbar of the thick film heating tube, wherein the film temperature thermometer is below the water outlet thermometer.

[0013] A heating film is laid on the surface of the thick film heating tube, and a film temperature thermometer and a water outlet thermometer are arranged in a non-heating film area, and a reserved distance between the water outlet thermometer and the heating film is greater than or equal to 4 mm.

[0014] The film temperature thermometer and the outlet water thermometer are infrared thermometers, NTC thermometers or thermocouple thermometers.

[0015] One or more water inlet structures are designed on the lower end cover, while the plug of the upper end cover has only one water outlet.

[0016] The thick film heating body structure involved in the present invention locks the spring flow channel in a fixed position by inserting the spring flow channel into the plug and arranging a positioning groove and a positioning protrusion on the plug, thereby ensuring the NTC detection position. The change of the NTC detection time does not affect the test water outlet temperature due to scaling of the heating body, and the water outlet temperature can be accurately controlled.

Brief Description of the Drawings

[0019] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] Please refer to the attached Figure 1 , which shows the thick film heating body structure involved in the present invention. For the thick film heating body structure, a spring is coiled outside the central tube and combined with a thick film heating tube to form a structure for water to coil through and heat. In this process, the film temperature and the water outlet temperature need to be monitored, so a film temperature thermometer and a water outlet thermometer are welded outside the thick film heating tube. In order to monitor the temperature as accurately as possible, the thermometer needs to be as close to the water outlet as possible, and the spring flow channel determines the direction of the water flow. In a conventional thick film heater, the spring is not fixed therein, and the water outlet position is also not fixed, so it is impossible to measure the water outlet temperature closest to the actual value.

[0021] Therefore, the present invention adds a plug with a spring positioning structure to the spring flow channel design, thereby limiting the spring flow channel from the circumferential direction and the axial direction, locking it between the central tube and the thick film heating tube, and ensuring the NTC monitoring position.

[0022] Please refer to the attached Figure 1 and attached Figure 2 , wherein the split structure of the heating body structure is shown, which includes a shell 10, a lower end cover 20, a sealing ring 30, a central tube 40, a spring flow channel 50, a plug 60, a thick film heating tube 70 and an upper end cover 80, the spring flow channel 50 surrounds the central tube 40, the thick film heating tube 70 is sleeved on the spring flow channel 50, the shell 10 covers the central tube 40, the spring flow channel 50 and the thick film heating tube 70 as a whole, and the upper end cover 80 and the lower end cover 20 are assembled on the upper and lower parts of the shell 10, Central tube 40: the innermost structure of the thick film heater as an integral inner core component; Spring flow channel 50: coiled and sleeved on the outer surface of the central tube, and its length is based on the standard of covering the length of the central tube; Thick film heating tube 70: The thick film heating tube 70 is set outside the central tube 40 and the spring flow channel 50, and the outer wall of the central tube 40, the spring flow channel 50 as a whole and the inner wall of the thick film heating tube 70 together constitute a heating spiral flow channel; wherein the difference between the inner diameter of the thick film heating tube and the outer diameter of the central tube should be slightly larger than the spring wire diameter of the spring flow channel, so as to maintain a space that can accommodate the spring flow channel and isolate a spiral flow channel for water flow inside.

[0023] Shell 10: The shell wraps the internal structure as a whole, protects the internal structure, and serves as the main structure for installing the upper and lower end covers; the upper and lower end covers are installed at the upper and lower ends thereof.

[0024] Lower end cover 20: having a water inlet structure, connected to the water inlet pipe, and realizing sealing and packaging with the main structure through the lower sealing ring; The upper end cover 80 has a water outlet structure, is connected to the water outlet pipe, and is sealed and packaged with the main structure through the upper sealing ring; Plug 60: It is arranged between the sealing ring 30 of the upper end cover 80 and the central tube 40, has a water outlet 61 connecting the upper end cover 80 and the flow channel, and is provided with a spring positioning structure 62, one end of the spring is inserted into the spring positioning structure 62 to limit the freedom of the spring flow channel 50.

[0025] Especially in the attached Figure 2 In the figure, the specific fitting and assembly relationship between the upper end cover and the plug can be seen, the water outlet 61 on the plug 60 is opened on the circumferential surface of the plug 60, and the spring positioning structure 62 is arranged next to the water outlet 61, in which the end of the local spring flow channel 50 is also inserted, satisfying: the spring positioning structure 62 is arranged outside the inserted end, and the coiling direction of the spring is away from the water outlet 61.

[0026] The structure design of the water outlet 61 on the plug 60 is to ensure that there is no coiled spring between the water outlet 61 and the water outlet thermometer / film temperature thermometer. The spacing between the last circle of the spring flow channel must accommodate the water outlet thermometer and the film temperature thermometer set on the same busbar, and the spacing between the film temperature thermometer and the spring must also meet the design requirements. This is because: The existing thermometers generally use NTC thermometers, and the NCT thermometer is set in the water channel. Due to the extremely complex local flow field, different flow fields and flow velocities cause serious local scaling, resulting in changes in the NTC detection time (due to the heat exchange between water and NTC crystal nuclei, the heat transfer is slow due to the scale heat group), and the whole machine is out of control when hot water is discharged. Therefore, the water outlet thermometer is set on the heating body. In this way, as long as the NTC detection temperature is not too high, the water temperature in the heating body will not be extra high; and there will be no interference with the flow field inside the heating body. In addition, in order to reduce the influence of the heating film on the water outlet NTC, the distance between the water outlet NTC and the heating film is designed to be ≥4mm, and the film temperature thermometer is located at a distance of ≥2mm from the upper side of the last circle of the spring flow channel. When NTC detects temperature, it is necessary to keep the position of NCT detection corresponding to the position of water in the flow channel in order to accurately monitor the temperature difference of heat transfer from water to NTC, so it is necessary to avoid the position of NTC pressing on the spring. Considering the manufacturing tolerance factor, the design requires that the technical characteristics of this spacing meet or exceed 2mm.

[0027] Please refer to the attached Figure 2 and attached Figure 3 As shown, the plug 60 includes an insertion end 63 and a positioning end 64 which are formed integrally, wherein the outer diameter of the insertion end 63 is interference fit with the inner diameter of the center tube 40, and the insertion end 63 is inserted into the center tube 40 for assembly; the positioning end 64 faces the upper end cover 80, and has a positioning groove 65 on the side facing the upper end cover 80. The positioning groove 65 is a structure used by the plug 60 to position and assemble with the upper end cover 80.

[0028] First, the plug 60 needs to be used to position the spring flow channel 50, and the plug 60 itself also needs to be self-positioned. The plug 60 positioning reference or double locking method keeps the plug 60 firmly and stably positioned. First, the plug 60 is inserted into the inner hole of the center tube 40 by means of interference fit with the insertion end 63 of the plug 60 to a certain extent of deformation and compression; second, the plug 60 is locked relative to the upper end cover through the positioning groove 65 between the plug 60 and the upper end cover 80.

[0029] The positioning groove 65 includes at least two grooves, and the corresponding bottom of the upper end cover 80 is provided with at least two positioning protrusions 81. The positioning protrusions 81 of the upper end cover are inserted into the positioning groove through the sealing ring 30 to define the position between the upper end cover 80 and the plug 60.

[0030] In terms of assembly sequence, the spring channel 50 surrounds the central tube 40, and then the plug 60 is inserted into the central tube 40, the spring channel 50 surrounds the central tube 40, and the end of the spring channel 50 is snapped into the spring positioning structure 62 on the plug 60, and then the thick film heating tube 70 and the outer shell 10 are covered on the outside, and the upper end cover 80 and the lower end cover 20 are installed above and below the outer shell 10, wherein the upper end cover is assembled into the positioning groove 65 of the plug with its positioning protrusion 81, and the upper end cover 80 and the end of the outer shell are also assembled by inserting and fastening the card end, so far, the plug 60 is limited relative to the central tube 40 and the upper end cover 80, and the spring channel 50 is snapped into the spring positioning structure 62 of the plug 60, and is limited relative to the central tube 40 by the plug 60, and the upper end cover 80 is fastened by the outer shell 10.

[0031] Please refer to the attached Figure 1 and attached Figure 4 A film temperature thermometer 72 and a water outlet thermometer 71 are provided on the thick film heating tube 70, and a film temperature thermometer 72 and a water outlet thermometer 71 are provided on the thick film heating tube 70 near the water outlet 61 of the plug 60, wherein the film temperature thermometer 72 and the water outlet thermometer 71 are arranged on the same busbar of the thick film heating tube 70, wherein the film temperature thermometer is below the water outlet thermometer.

[0032] A heating film 73 is laid on the surface of the thick film heating tube 70, and the film temperature thermometer 72 and the water outlet thermometer 71 are arranged in the non-heating film area, and the reserved distance between the water outlet thermometer 71 and the heating film 73 is greater than or equal to 4 mm. This is to prevent the heat generated by the heating film 73 from interfering with the temperature measurement process of the water outlet thermometer 71, and to prevent the measured water outlet temperature from being inaccurate.

[0033] The distance L between the film temperature thermometer 72 and the upper side of the last circle of the spring flow channel is greater than or equal to 2 mm.

[0034] The film temperature thermometer 72 and the outlet water thermometer 71 are infrared thermometers, NTC thermometers or thermocouple thermometers.

[0035] One or more water inlet structures are designed on the lower end cover 20, while the plug of the upper end cover 80 has only one water outlet.

[0036] A positioning convex point is arranged on the lower end cover to define the other end of the spring flow channel.

[0037] The thick film heating body structure involved in the present invention locks the spring flow channel in a fixed position by inserting the spring flow channel into the plug and arranging a positioning groove and a positioning protrusion on the plug, thereby ensuring the NTC detection position. The change of the NTC detection time does not affect the test water outlet temperature due to scaling of the heating body, and the water outlet temperature can be accurately controlled.

[0038] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention is disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technology of the present invention are within the scope of the technical solution of the present invention without departing from the content of the technical solution of the present invention.

Claims

1. A thick film heating body structure, comprising an outer shell, a lower end cover, a sealing ring, a central tube, a spring flow channel, a plug, a thick film heating tube and an upper end cover, wherein the spring flow channel surrounds the central tube, the thick film heating tube is sleeved on the spring flow channel, the outer shell as a whole covers the central tube, the spring flow channel and the thick film heating tube combination part, and the upper end cover and the lower end cover are assembled on the upper and lower ends of the outer shell, It is characterized in that Center tube: The innermost structure of the rear heating body is the integral inner core component; Spring flow channel: The coiled sleeve is arranged on the outer surface of the center tube, and its length is based on the length that can cover the center tube; Thick film heating tube: The thick film heating tube sleeve is arranged outside the central tube and the spring flow channel. The outer wall of the central tube, the entire spring flow channel and the inner wall of the thick film heating tube together constitute a heating spiral flow channel. The thick film heating tube is provided with a film temperature thermometer and a water outlet thermometer; Shell: It wraps the internal structure as a whole and serves as the main structure for installing the upper and lower end covers; Lower end cover: has a water inlet structure, connected to the water inlet pipe, and realizes sealing and packaging with the main structure through the lower sealing ring; Upper end cover: has a water outlet structure, connected to the water outlet pipe, and realizes sealing and packaging with the main structure through the upper sealing ring; Plug: It is arranged between the sealing ring of the upper end cover and the central tube, has a water outlet connecting the upper end cover and the flow channel, and is provided with a spring positioning structure, one end of the spring is inserted into the spring positioning structure to limit the freedom of the spring.

2. According to the thick film heater structure of claim 1, It is characterized in that The water outlet on the plug is opened on the circumferential surface of the plug, and the spring positioning structure is arranged beside the water outlet, which satisfies: the spring coiling direction of the spring positioning structure arranged outside the clamping end is away from the water outlet.

3. According to the thick film heater structure of claim 2, It is characterized in that The distance between the film temperature thermometer and the upper side of the last circle of the spring flow channel is greater than or equal to 2 mm.

4. The thick film heater structure according to claim 2, It is characterized in that The plug includes an integral insertion end and a positioning end, wherein the outer diameter of the insertion end is interference fit with the inner diameter of the center tube, and the insertion end is inserted into the center tube for assembly; the positioning end faces the upper end cover, and has a positioning groove on the side facing the upper end cover.

5. The thick film heater structure according to claim 4, It is characterized in that The positioning groove includes at least two grooves, and the corresponding bottom of the upper end cover is provided with at least two positioning protrusions. The positioning protrusions of the upper end cover are inserted into the positioning groove through the sealing ring to define the position between the upper end cover and the plug.

6. The thick film heater structure according to claim 3, It is characterized in that A film temperature thermometer and a water outlet thermometer are provided on the thick film heater, and a film temperature thermometer and a water outlet thermometer are provided near the water outlet of the plug of the thick film heater, wherein the film temperature thermometer and the water outlet thermometer are arranged on the same busbar of the thick film heater, wherein the film temperature thermometer is below the water outlet thermometer.

7. The thick film heater structure according to claim 6, It is characterized in that A heating film is laid on the surface of the thick film heater, and a film temperature thermometer and a water outlet thermometer are arranged in a non-heating film area, with a reserved spacing of 4 mm or more from the water outlet thermometer to the heating film.

8. The thick film heater structure according to claim 6, It is characterized in that The film temperature thermometer and the outlet water thermometer are infrared thermometers, NTC thermometers or thermocouple thermometers.

9. The thick film heater structure according to any one of claims 1 to 8, It is characterized in that One or more water inlet structures are designed on the lower end cover, while the plug of the upper end cover has only one water outlet.

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