Single-head heating pipe die-casting type liquid heater assembly

Abstract

The utility model relates to an electric heater technology, and aims to provide a single-head heating pipe die-casting type liquid heater assembly. The product comprises a metal shell with a cavity structure and a single-head electric heating tube mounted in the metal shell, the metal shell is of an integrated structure and comprises an outer shell body and two fin structures located in the shell body. The two fin structures are connected through the top and the bottom to form a space used for installing an electric heating pipe, and the two fin structures are connected with the shells on the two sides through the top and the bottom to form liquid flow channels. A liquid flow channel composed of the water inlet pipe, the water inlet pipe side fin structure, the electric heating pipe closed end, the water outlet pipe side fin structure and the water outlet pipe is formed. The utility model has the advantages of small volume, simple structure, reliable sealing and the like, and further based on the design of temperature detection and temperature protection, the heating operation is stable and reliable; the turbulent flow effect is improved while the higher circulation efficiency is guaranteed, the better heat exchange effect can be obtained, and the operation failure rate can be reduced.

Description

Technical Field

[0001] The utility model relates to the technology of electric heaters, and particularly to a single-head heating pipe die-cast liquid heater assembly. Background Art

[0002] New energy vehicles are becoming more and more popular due to their environmental friendliness. Since they lose the engine as a heat source, new energy vehicles need to add other heating methods to meet the heating requirements of the battery and the cabin. Currently, the heating methods used more in the market include PTC heaters, metal tubular heaters, and aluminum casting heaters, etc. Among them, although the PTC heater has the advantages of self-limiting temperature function and high thermal efficiency, its service life is shorter than that of the metal tubular heater, and there is a serious problem of power attenuation. The metal tubular heater has high temperature control accuracy and fast thermal response, and is also used in some current vehicle models. However, due to the limited outer surface area of the heating pipe and small heat exchange surface, it is difficult to meet the high-power heating requirements. The metal tubular heater with an aluminum die-cast structure has the advantages of the metal tubular heater, and at the same time increases the heat exchange area and improves the heat exchange efficiency. Compared with the metal tubular heater, the aluminum casting heater has a wider power range and a safer use environment. However, due to the limitations of the product size and shape, designers generally believe that the liquid flow channel of such products is difficult to design and process, and it is impossible to better achieve the best heat exchange efficiency.

[0003] Researchers have achieved some research results in vehicle coolant heating technology. For example, Takakazu Koto described a heater with a metal heating pipe nested in a housing in his patent "Heating Device" (CN 104247559 B), which uses a heating element to heat the heat medium introduced into the housing. However, this heater structure uses rubber rings for sealing at both ends, and there is a risk of seal failure due to rubber part aging over time. Yoshinobu Maemura described a heating device with a temperature detection element in his patent "Heating Device" (CN104272862 B), which forms a flow path for the heat medium between the housing and the heating part. However, since the contact area between the temperature detection device of this heating device and the outer surface of the heating pipe is small, there are also problems of poor contact and poor temperature sensing. More importantly, the liquid flow channels in the above heating devices are simply composed of the outer shell of the metal heating pipe and the inner wall of the container, resulting in the coolant mostly flowing straight through the nearest channel, and the temperature at the end or local part of the heating pipe is too high due to poor heat dissipation, causing frequent equipment failures and shortened service life.

[0004] Based on the actual production needs and the existing defects of the prior art, this application intends to propose a liquid heater product with reliable sealing, sensitive temperature sensing, and good heat exchange effect. Summary of the Utility Model

[0005] The technical problem to be solved by the present utility model is to overcome the deficiencies in the prior art and provide a single-head heating tube die-cast liquid heater assembly.

[0006] To solve the above technical problem, the solution adopted by the present utility model is:

[0007] Provide a single-head heating tube die-cast liquid heater assembly, including a metal shell with a cavity structure and a heating tube installed in the metal shell;

[0008] The heating tube is a single-head electric heating tube with a tubular shell of regular shape, one end of which is closed and the other end leads out welding terminals;

[0009] The metal shell is an integral structure, including an outer shell and two fin structures located inside the shell; the two fin structures are connected by the top and bottom to form a space for installing the electric heating tube, and the two fin structures are closely attached to the outer surface of the electric heating tube to ensure the heat exchange effect; the two fin structures are respectively connected by the top and bottom to the two sides of the shell to form their respective liquid flow channels, and the fins are located inside the flow channel cavities; sealing sheets for sealing the flow channel cavities are respectively arranged at both ends of the shell, and a spacing is maintained between the closed end of the electric heating tube and the end sealing sheet of the shell as the flow channel; a water inlet pipe and a water outlet pipe are arranged at the other end of the shell opposite to the closed end of the electric heating tube, and the water inlet pipe and the water outlet pipe are respectively communicated with one fin structure, so as to form a liquid flow channel composed of the water inlet pipe, the fin structure on the water inlet pipe side, the closed end of the electric heating tube, the fin structure on the water outlet pipe side and the water outlet pipe.

[0010] As an improved scheme, the shell is in a long strip column shape, and its cross-sectional shape is rectangular or runway-shaped; the cross-sectional shape of the electric heating tube is circular or oval; the shell and the electric heating tube are coaxially arranged.

[0011] As an improved scheme, NTC assembly grooves are respectively arranged on the shell near the water inlet pipe and the water outlet pipe, and NTC components are fixedly installed in the NTC assembly grooves in a screwed or welded manner.

[0012] As an improved scheme, a temperature control switch is fixedly installed in the middle section of the shell, and the welding terminals of the electric heating tube and the temperature control switch are connected to an external power supply through wires to form a circuit.

[0013] As an improved scheme, at least two groups of sheet-shaped mounting brackets are arranged on the shell, and reinforcing ribs are arranged between the mounting brackets and the shell.

[0014] As an improved scheme, the side of the fin structure close to the electric heating tube is a smooth curved surface, and a plurality of fins parallel to the axial direction extend from the smooth curved surface, and the ends of the fins are spaced from the shell.

[0015] As an improved solution, the encapsulation sheet is fixed to the end of the housing by welding.

[0016] As an improved solution, the encapsulation sheet located at the non-closed end of the electric heating tube has two openings for passing through the welding terminals; alternatively, the encapsulation sheet is a split structure, and its opposite side edges are in a concave shape to leave an installation position for the welding terminals.

[0017] As an improved solution, the metal housing is an integrally cast aluminum structure formed by die-casting process, and its fin structure surrounds the outside of the electric heating tube.

[0018] As an improved solution, a magnesium oxide rod is coaxially arranged inside the tubular housing of the single-head electric heating tube, and two metal lead rods are axially and alternately arranged through the magnesium oxide rod; both ends of the metal lead rods pass through the magnesium oxide rod and are respectively sleeved in the middle protection pieces for positioning, and insulating sheets are arranged on the outer sides of the two middle protection pieces; at the non-closed end of the electric heating tube, welding terminals are connected to the metal lead rods and structural adhesive is filled at this end for sealing; an electric heating wire is evenly wound around the magnesium oxide rod, magnesium oxide powder is filled between the electric heating wire and the tubular housing, and the electric heating wire is connected to the two metal lead rods by welding at both ends of the magnesium oxide rod to form a series circuit.

[0019] Compared with the prior art, the technical effects of the present utility model are as follows:

[0020] 1. The liquid heater assembly of the present utility model has the advantages of small volume, simple structure, reliable sealing, etc. Further combined with the design of temperature detection and temperature protection, its heating operation is stable and reliable.

[0021] 2. The single-head heating tube in the present utility model adopts a metal housing, which can not only ensure sufficient sealing strength but also ensure effective heat transfer and exchange.

[0022] 3. In the present utility model, the metal housing and the fin structure are an integral structure formed by die-casting process. The two fin structures are closely attached to the outer surface of the electric heating tube, which can ensure the heat exchange effect; the two fin structures respectively form their own liquid flow channels with the metal housings on both sides, and the fins are located in the flow channel cavities, which can increase the turbulence effect while ensuring greater flow efficiency and can obtain a better heat exchange effect.

[0023] 4. The main structure of the present utility model is made by die-casting process, and the encapsulation sheet is fixed by welding. Therefore, the overall structure is firm and the sealing is reliable, greatly reducing the failure rate during the operation of the product and improving the service life of the product. Description of the Drawings

[0024] Figure 1 It is a top view of the liquid heater;

[0025] Figure 2 Exploded view of a liquid heater;

[0026] Figure 3 Exploded view of a liquid heater from another perspective;

[0027] Figure 4 Assembly drawing of a single - head heating tube;

[0028] Figure 5 For Figure 4 Cross - sectional view taken along the B - B direction in

[0029] Figure 6 Top view of the housing;

[0030] Figure 7 Cross - sectional view of the housing.

[0031] Reference numerals in the figure: 1 - outer shell (of the electric heating tube); 2 - insulating sheet; 3 - middle - protecting sheet; 4 - heating wire; 5 - magnesium oxide powder; 6 - magnesium oxide rod; 7 - metal lead rod; 8 - structural adhesive; 9 - welding terminal; 10 - wire; 11 - electric heating tube; 12 - housing; 13 - encapsulating sheet; 14 - encapsulating sheet; 15 - encapsulating sheet; 16 - NTC component; 17 - temperature control switch; 18 - screw; 19 - wire; 121 - water inlet pipe; 122 - water outlet pipe; 123 - NTC assembly groove; 124 - NTC assembly groove; 125 - mounting bracket; 126 - temperature control switch groove; 127 - fin. Detailed implementation manners

[0032] The following combines with the attached drawings to describe in detail the detailed implementation manners of the present utility model.

[0033] The first part - implementation solution of the present utility model

[0034] The single - head heating tube die - casting type liquid heater assembly of the present utility model includes a metal housing with a cavity structure and a heating tube installed in the metal housing;

[0035] The heating tube is a single - head electric heating tube 11 with a tubular outer shell 1 of regular shape; inside the outer shell 1, a magnesium oxide rod 6 is coaxially arranged, and two metal lead rods 7 are axially and alternately penetrated inside the magnesium oxide rod 6; the two ends of the metal lead rods 7 penetrate out of the magnesium oxide rod 6 and are respectively sleeved in the middle - protecting sheets 3 for positioning, and insulating sheets 2 are respectively arranged outside the two middle - protecting sheets 3; at the non - closed end of the electric heating tube 11, a welding terminal 9 is connected to the metal lead rod 7, and structural adhesive 8 is filled at this end for sealing; the heating wire 4 is evenly wound around the magnesium oxide rod 6, and magnesium oxide powder 5 is filled between the heating wire 4 and the outer shell 1; the heating wire 4 is respectively connected to the two metal lead rods 6 by welding at both ends of the magnesium oxide rod 6 to form a series circuit.

[0036] The metal housing is an integral structure formed by die-casting a metal material (such as aluminum), including the outer housing 12 and two fin structures located inside the housing 12; the two fin structures are connected by their tops and bottoms to form a space for installing the electric heating tube 11, and the two fin structures are in close contact with the outer surface of the electric heating tube 11 to ensure the heat exchange effect; the two fin structures are respectively connected to the two side housings 12 by their tops and bottoms to form their respective liquid flow channels, and the fins are located inside the flow channel cavities. As an example, the side of the fin structure close to the electric heating tube 11 is a smooth curved surface, and multiple fins 127 parallel to the axial direction extend from this smooth curved surface, and the ends of the fins 127 are spaced from the housing (such as Figure 7 as shown). Sealing sheets 13-15 for sealing the flow channel cavities are respectively fixed at both ends of the housing 12 by welding, and a spacing is maintained between the closed end of the electric heating tube and the end sealing sheet of the housing as the flow channel. At the other end of the housing 12 opposite to the closed end of the electric heating tube 11, a water inlet pipe 121 and a water outlet pipe 122 are provided; the water inlet pipe 121 and the water outlet pipe 122 are respectively communicated with one fin structure, so as to form a liquid flow channel composed of the water inlet pipe 121, the fin structure on the water inlet pipe side, the closed end of the electric heating tube, the fin structure on the water outlet pipe side, and the water outlet pipe 122.

[0037] NTC assembly grooves 123 and 124 are respectively provided on the housing close to the water inlet pipe 121 and the water outlet pipe 122, and the NTC components 16 are fixedly installed by screwing or welding. A temperature control switch 17 is fixedly installed in the middle section of the housing 12, and the welding terminals 9 of the electric heating tube 11 and the temperature control switch 17 are connected to an external power supply through a wire 19 to form a circuit. At least two groups of sheet-shaped mounting brackets 125 are provided on the housing 12, and reinforcing ribs are provided between the mounting brackets 125 and the housing 12.

[0038] As an alternative example, the housing 12 is in a long strip column shape, and its cross-sectional shape is rectangular or runway-shaped; the cross-sectional shape of the electric heating tube 11 is circular or oval; the housing 12 and the electric heating tube 11 are coaxially arranged. The sealing sheet at the non-closed end of the electric heating tube has two openings for passing through the welding terminals; alternatively, the sealing sheets 13 and 14 are two split structures, and their opposite side edges are in a concave shape to leave an installation position for the welding terminals.

[0039] The second part A specific example

[0040] The single-head heating tube die-cast liquid heater assembly in this example can be processed according to the following method: First, a single-head electric heating rod 11 is made by conventional processing technology. Then it is placed in a die-casting mold, high-temperature liquid aluminum is injected, and pressure is applied to make the liquid aluminum quickly solidify to form a metal housing with an integral structure. The tops and bottoms of the two fin structures are connected and are in close contact with the outer surface of the electric heating tube 11, which can ensure the heat exchange effect to the greatest extent.

[0041] When the metal shell is formed by die casting, a plurality of integrated structural components are pre-set in the shell 12 at the same time, for example, a temperature control switch slot 126 is reserved in the middle of the shell 11 to facilitate the assembly of the temperature control switch 17 for thermal protection. NTC assembly slots 123 and 124 are reserved at the positions of the water inlet pipe 121 and the water outlet pipe 122, respectively, and the NTC component 16 can be fixed by threaded fastening or welding to monitor the temperature of the inlet and outlet water. Multiple fins 127 are formed inside the shell 12, which can greatly increase the heat dissipation area and improve the heat exchange efficiency, and effectively avoid the risk of single-head heating tube melting due to local overheating. Four mounting brackets 125 are provided on the outside of the shell 12 and are equipped with reinforcing ribs. Based on the integrated die-casting process, its reliability and strength can be improved, and the instability phenomenon of the welded or screwed brackets in conventional products after long-term operation can be avoided. The two ends of the shell 12 are sealed by aluminum sheet encapsulation sheets 13-15, which can be fixed by welding.

[0042] The single-head electric heating tube 11 can be processed according to conventional processes. As an example, it is composed of a magnesium oxide rod 6, a low-resistivity metal lead rod 7, a high-resistance alloy resistance wire 4, magnesium oxide powder 5, a centering sheet 3, an insulating sheet 2, a metal shell 1, a sealing structural adhesive 8 and a wire assembly 10. Different from the resistance wire wound without a core rod, the resistance wire 4 is evenly wound on the magnesium oxide rod 6, which not only ensures the outer diameter of the resistance wire 4 in the radial direction of the heating tube, but also ensures that the heat can be evenly distributed along the axial direction of the magnesium oxide rod 6 during operation. Two low-resistivity metal lead rods 7 pass through the through hole in the middle of the magnesium oxide rod 6, and the resistance wire 4 is connected to the two lead rods at both ends of the magnesium oxide rod 6 by welding ( Figure 5 The centering sheet 3 can ensure that the magnesium oxide rod 6 is placed in the center of the housing 1 to avoid the reduction of the creepage distance due to eccentricity and ensure that it can withstand high voltage shock without being broken down. The metal housing 1 of the single-head electric heating tube can ensure sufficient sealing strength and effective heat transfer and exchange.

Claims

1. A single-head heating tube die-cast liquid heater assembly, comprising a metal shell with a cavity structure, and a heating tube installed in the metal shell; characterized in that: The heating tube is a single-end electric heating tube with a tubular shell of regular shape, one end of which is closed and the other end leads to a welding terminal; The metal shell is an integrated structure, including an external shell and two fin structures located inside the shell; the two fin structures are connected by top and bottom to form a space for installing the electric heating tube, and the two fin structures are tightly fitted to the outer surface of the electric heating tube to ensure the heat exchange effect; the two fin structures are respectively connected to the shells on both sides by top and bottom to form their own liquid flow channels, and the fins are located in the flow channel cavity; packaging sheets for sealing the flow channel cavity are respectively arranged at both ends of the shell, and a distance is maintained between the closed end of the electric heating tube and the packaging sheet at the end of the shell as a flow channel; a water inlet pipe and a water outlet pipe are arranged at the other end of the shell opposite to the closed end of the electric heating tube, and the water inlet pipe and the water outlet pipe are respectively connected to a fin structure, thereby forming a liquid flow channel composed of a water inlet pipe, a fin structure on the water inlet pipe side, the closed end of the electric heating tube, a fin structure on the water outlet pipe side and a water outlet pipe.

2. The single-head heating tube die-casting liquid heater assembly according to claim 1 is characterized in that: The shell is in the shape of a long column, and its cross-section is in the shape of a rectangle or a racetrack; the cross-section of the electric heating tube is in the shape of a circle or an ellipse; the shell and the electric heating tube are coaxially arranged.

3. The single-head heating tube die-casting liquid heater assembly according to claim 1 is characterized in that: NTC assembly grooves are respectively arranged on the shell body near the water inlet pipe and the water outlet pipe, and the NTC components are fixedly installed in the NTC assembly grooves by screwing or welding.

4. The single-head heating tube die-casting liquid heater assembly according to claim 1 is characterized in that: A temperature control switch is fixedly installed in the middle section of the shell, and the welding terminal of the electric heating tube and the temperature control switch are connected to an external power supply through a wire to form a loop.

5. The single-head heating tube die-casting liquid heater assembly according to claim 1 is characterized in that: At least two groups of sheet-shaped mounting brackets are arranged on the shell, and reinforcing ribs are arranged between the mounting brackets and the shell.

6. The single-head heating tube die-casting liquid heater assembly according to claim 1, characterized in that: The side of the fin structure close to the electric heating tube is a smooth curved surface, and a plurality of fins parallel to the axial direction extend from the smooth curved surface, and the end of each fin maintains a distance from the shell.

7. The single-head heating tube die-casting liquid heater assembly according to claim 1, characterized in that: The packaging sheet is fixed to the end of the shell by welding.

8. The single-head heating tube die-casting liquid heater assembly according to claim 1, characterized in that: The packaging sheet located at the non-enclosed end of the electric heating tube has two openings for passing the welding terminals; or, the packaging sheet is two separate structures, and the opposite side edges thereof are concave in shape to reserve installation positions for the welding terminals.

9. The single-head heating tube die-casting liquid heater assembly according to claim 1, characterized in that: The metal shell is an integrated cast aluminum structure formed by a die-casting process, and its fin structure surrounds the outer side of the electric heating tube.

10. The single-head heating tube die-casting liquid heater assembly according to claim 1, characterized in that: A magnesium oxide rod is coaxially arranged in the tubular shell of the single-head electric heating tube, and two metal lead rods are axially alternately arranged inside the magnesium oxide rod; the two ends of the metal lead rod pass through the magnesium oxide rod and are respectively inserted into the center-protecting sheets to achieve positioning, and insulating sheets are arranged on the outsides of the two center-protecting sheets; at the non-closed end of the electric heating tube, a welding terminal is connected to the metal lead rod and structural adhesive is filled at the end for sealing; an electric heating wire is evenly wound on the magnesium oxide rod, and magnesium oxide powder is filled between the electric heating wire and the tubular shell, and the electric heating wire is respectively connected to the two metal lead rods by welding at both ends of the magnesium oxide rod to form a series circuit.

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