An electric heating block structure

Abstract

The utility model discloses an electric heating block structure, including stainless steel shell, aluminium core and heating pipe, the inside of aluminium core is equipped with the expansion cavity of extending to aluminium core bottom, the stainless steel shell is equipped in aluminium core outside, the outside of aluminium core is provided with at least one recessed cooperation slot, the inside of stainless steel shell is equipped with the convex structure, the convex structure is inserted cooperation slot in. Form the clamping cooperation through setting cooperation slot in aluminium core outer periphery, the convex structure is set in the inner wall of stainless steel shell, and the design of the bottom inside edge compression can effectively prevent the problem that aluminium core appears loose, displacement or drop -out in long -time cold -hot cycle process, improves overall structure stability and service life.

Description

Technical Field

[0001] This utility model relates to the field of heating element technology, specifically to an electric heating block with a composite structure of aluminum core and stainless steel shell, which is suitable for use in steam heating or liquid heating equipment. Background Technology

[0002] Electric heating blocks are a common type of heating element, widely used in heating applications such as kitchen appliances and industrial equipment, especially suitable for equipment requiring rapid heating, such as steamed bun machines and steam boilers. Currently, mainstream electric heating blocks on the market often employ a composite structure of an aluminum core and a stainless steel outer shell. This combination leverages the high thermal conductivity of aluminum and the corrosion resistance of stainless steel to achieve both heating efficiency and structural durability.

[0003] In existing technologies, aluminum cores are typically embedded into stainless steel shells through cold or hot pressing, utilizing the plastic deformation of the metal to eliminate gaps in the fit. However, during long-term use, due to the thermal expansion and contraction effect caused by alternating hot and cold cycles, the aluminum core and stainless steel are prone to loosening or even detachment, affecting service life and thermal conductivity. Furthermore, most existing aluminum cores are solid structures; when heated to high temperatures, the core temperature becomes excessively high, easily causing coarsening of the aluminum grains, leading to increased brittleness and crack formation, further weakening structural strength and safety.

[0004] Furthermore, since aluminum has a significantly higher coefficient of thermal expansion than stainless steel, the difference in expansion between the two increases with rising temperature, making it easier for gaps to form and reducing heat transfer efficiency. Therefore, existing aluminum-core stainless steel electric heating blocks suffer from poor reliability and unstable thermal efficiency, necessitating improvements in structural design and assembly processes. Utility Model Content

[0005] In view of the shortcomings of the prior art, this utility model provides an electric heating block structure. By setting a matching groove on the outer periphery of the aluminum core and setting a protruding structure on the inner wall of the stainless steel shell to form a locking fit, combined with the bottom inner folded edge pressing design, it can effectively prevent the aluminum core from loosening, displacing or falling off during long-term hot and cold cycles, thereby improving the overall structural stability and service life.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] An electric heating block structure includes a stainless steel outer shell, an aluminum core, and a heating tube. The aluminum core has an expansion cavity extending to its bottom. The stainless steel outer shell is fitted over the aluminum core. The outer side of the aluminum core has at least one inwardly recessed mating groove. The inner side of the stainless steel outer shell has a protruding structure that engages with the mating groove. The expansion cavity is used to reduce the core temperature and prevent thermal degradation of the aluminum material.

[0008] As a preferred technical solution, the aluminum core is a frustum-shaped, cylindrical, or conical rotating body structure; or a polyhedral structure of a regular prism, oblique prism, regular pyramid, or oblique pyramid; or a stepped structure with one or more axial steps, including: stepped frustums and stepped cylinders, both of which have a diameter that changes in a stepped manner along the axial direction; stepped prisms and stepped cones, both of which have a taper that changes in a stepped manner along the axial direction.

[0009] As a preferred technical solution, the expansion cavity is one of a cylindrical cavity, a conical cavity, or a frustum-shaped cavity, used to adjust the thermal expansion distribution inside the aluminum core and reduce stress concentration in the core.

[0010] As a preferred technical solution, the heating tube is die-cast into the interior of the aluminum core.

[0011] As a preferred technical solution, the heating tube has a double helix structure and is distributed inside the aluminum core close to the stainless steel outer shell to improve thermal conductivity.

[0012] As a preferred technical solution, the bottom of the stainless steel shell is provided with an inwardly extending flange, which presses against the bottom edge of the aluminum core to further enhance the limiting and fastening effect of the structure.

[0013] As a preferred technical solution, the mating groove is an annular groove arranged along the circumference of the aluminum core, and the protruding structure is an inwardly recessed structure formed on the outer surface of the stainless steel shell by a rolling process, with the groove surface of the inwardly recessed structure being an arc-shaped curved surface. This facilitates the easy removal and cleaning of scale deposits during use, and a sealing structure can also be provided at this location.

[0014] As a preferred technical solution, the stainless steel outer shell and the aluminum core are interference fit.

[0015] The beneficial effects of this utility model are:

[0016] 1. This utility model forms a locking fit by setting a matching groove on the outer periphery of the aluminum core and a protruding structure on the inner wall of the stainless steel shell. Combined with the bottom inner folded edge pressing design, it can effectively prevent the aluminum core from loosening, shifting or falling off during long-term hot and cold cycles, thereby improving the overall structural stability and service life.

[0017] 2. The aluminum core, as a high thermal conductivity body, is arranged with double spiral heating tubes near the outer side of the aluminum core, which further shortens the heat transfer path and improves heating efficiency. It is suitable for scenarios that require rapid heating, such as steam boilers and steamed bun machines.

[0018] 3. The aluminum core is equipped with a longitudinal expansion cavity, which can effectively regulate the concentration of internal thermal stress, avoid heat accumulation in the central area, reduce material fatigue and performance degradation caused by overheating, and also avoid problems such as coarsening, cracking and embrittlement of aluminum grains caused by local overheating, thus improving the thermal shock resistance.

[0019] 4. The aluminum core adopts a frustum or stepped frustum structure, so that its shape forms a natural interference fit with the stainless steel shell, which improves the fitting accuracy and heat conduction efficiency, and is also conducive to processing and installation positioning. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic cross-sectional view of the electric heating block in Example 1;

[0022] Figure 2 for Figure 1 A magnified structural diagram of part A in the middle;

[0023] Figure 3 This is a schematic diagram of the structure of the electric heating block in Example 1;

[0024] Figure 4 This is a schematic cross-sectional view of the electric heating block in Example 2;

[0025] Figure 5 This is a schematic diagram of the heating element in the embodiment.

[0026] In the figure, 1 is a stainless steel shell; 11 is a recessed structure; 111 is a raised structure; 12 is a folded edge; 13 is a first extended surface; 14 is a second extended surface; 2 is an aluminum core; 21 is an expansion cavity; 22 is a mating groove; 23 is a fixing hole; 3 is a heating tube; and 31 is a wiring terminal. Detailed Implementation

[0027] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0028] Example 1, such as Figures 1 to 3As shown, this embodiment provides an electric heating block structure, including a stainless steel shell 1, an aluminum core 2, and a heating tube 3. The aluminum core 2 has an external shape of a stepped frustum structure with two steps, that is, the diameter of the upper circle is smaller than the diameter of the lower circle. The shape of the stainless steel shell 1 is adapted to the aluminum core 2, and the stainless steel shell 1 is sleeved on the outside of the aluminum core 2. The lower part of the stainless steel shell 1 is provided with two outwardly extending mounting extension surfaces, namely a first extension surface 13 and a second extension surface 14, for mounting auxiliary components such as sealing rings.

[0029] In terms of processing technology, the aluminum core 2 and the heating tube 3 are first integrally die-cast into an aluminum die-cast part, so that the heating tube 3 is inserted into the bottom of the aluminum core 2 and arranged inside it; then the aluminum die-cast part is pressed into the stainless steel shell 1 with an interference fit to form a tightly embedded structure. In order to enhance the limiting and anti-loosening effect, an inwardly recessed structure 11 is rolled on the outer circumference of the stainless steel shell 1, and then a raised structure 111 is formed on the inner side of the stainless steel shell 1. The raised structure 111 corresponds to and engages with the mating groove 22 reserved on the outside of the aluminum core 2. The mating groove is an annular groove set along the circumference of the aluminum core 2.

[0030] Furthermore, an inwardly extending flange 12 is formed by bending the bottom of the stainless steel outer shell 1. This flange 12 presses tightly against the bottom edge of the aluminum core 2, thereby enhancing the axial fixation effect of the overall structure. In this embodiment, a portion of the bottom area of ​​the aluminum core 2 and the wiring terminals 31 of the heating tube 3 are exposed outside the stainless steel outer shell 1, and the stainless steel outer shell 1 and the aluminum core 2 are tightly fitted together.

[0031] When powered on, the heat generated by the heating element 3 is first conducted to the aluminum core 2, and then transferred to the heated medium via the stainless steel outer shell 1. This structural design ensures a stable and tight connection between the aluminum core 2 and the stainless steel outer shell 1, preventing movement or loosening due to thermal expansion and contraction, while maintaining good heat transfer efficiency.

[0032] To prevent the center temperature of the aluminum core 2 from becoming too high during use and to reduce the expansion stress on the outer side of the aluminum core 2 under heating conditions, at least one expansion cavity 21 extending towards the inner center is provided at the bottom 21 of the aluminum core 2. This helps to balance the temperature distribution and prevent thermal degradation of the aluminum material. The expansion cavity 21 can be one of a cylindrical cavity, a conical cavity, or a frustum-shaped cavity.

[0033] To improve heating efficiency, heating element 3 adopts a double-helix structure, such as... Figure 5 As shown, it is arranged inside the aluminum core 2 near the stainless steel outer shell 1, which further shortens the heat conduction path and improves the heating efficiency.

[0034] In addition, to achieve over-temperature protection control, the bottom of the aluminum core 2 is provided with a fixing hole 23 for installing a temperature control switch or a temperature protection device. When the temperature exceeds the set threshold, the power supply can be automatically cut off to ensure safe use.

[0035] Considering that scale easily forms on the surface of the outer shell of the electric heating block when it is used in water for a long time, and the thickening of scale will reduce the heating efficiency of the electric heating block, the concave surface of the recessed structure 11 is designed as an arc-shaped curved surface structure to facilitate subsequent cleaning. This helps to reduce the intensity of scale buildup, improve cleaning efficiency and delay the decline in heating efficiency. A sealing structure can also be set here.

[0036] Example 2, combined Figure 4 The difference between this embodiment and Embodiment 1 is that the outer shape of the aluminum core 2 is a frustum of a circle, and the stainless steel outer shell 1 is fitted onto the outside of the aluminum core 2. The processing technology of this electric heating block is as follows: first, the aluminum core 2 and the heating tube 3 are die-cast into an aluminum die-cast part. The heating tube 3 is inserted into the interior of the aluminum core 2 from the bottom 21. Then, the aluminum die-cast part and the stainless steel outer shell 1 are interference-fitted and tightly fitted. Next, two inwardly recessed structures 11 are rolled on the outside of the stainless steel outer shell 1 to clamp the aluminum die-cast part (a matching groove 22 is left at the corresponding position of the aluminum core 2). The difference from Embodiment 1 is that the outer shapes of the aluminum core 2 and the stainless steel outer shell 1 are both frustums of a circle, the stainless steel outer shell 1 has an additional rolled recessed structure 11, and the bottom of the stainless steel outer shell 1 does not have an inwardly extending folded edge 12.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. An electrical heating block structure, characterized by, The device includes a stainless steel shell (1), an aluminum core (2) and a heating tube (3). The aluminum core (2) has an expansion cavity (21) extending to the bottom of the aluminum core (2). The stainless steel shell (1) is fitted on the outside of the aluminum core (2). The outside of the aluminum core (2) is provided with at least one inwardly recessed mating groove (22). The inside of the stainless steel shell (1) is provided with a protruding structure (111), which is inserted into the mating groove (22).

2. An electrical heating block structure according to claim 1, wherein, The aluminum core (2) is a frustum-shaped, cylindrical, or conical rotating body structure; or a polyhedral structure of a regular prism, oblique prism, regular pyramid, or oblique pyramid. Alternatively, it can be a stepped structure with one or more axial steps, including: a stepped frustum, a stepped cylinder, a stepped prism, or a stepped cone.

3. The electric heating block structure according to claim 1, characterized in that, The expansion cavity (21) is one of a cylindrical cavity, a conical cavity, or a frustum-shaped cavity.

4. The electric heating block structure according to claim 1, characterized in that, The heating tube (3) is die-cast into the interior of the aluminum core (2).

5. The electric heating block structure according to claim 1, characterized in that, The heating tube (3) has a double helix structure and is distributed inside the aluminum core (2) close to the stainless steel outer shell (1).

6. The electric heating block structure according to claim 1, characterized in that, The stainless steel outer shell (1) has an inwardly extending flange (12) at the bottom, which presses against the bottom edge of the aluminum core (2).

7. The electric heating block structure according to claim 1, characterized in that, The mating groove (22) is an annular groove set along the circumference of the aluminum core (2), and the protruding structure (111) is a recessed structure (11) formed from the outside to the inside on the outer surface of the stainless steel shell (1) by a rolling process, and the groove surface of the recessed structure (11) is an arc-shaped curved surface.

8. The electric heating block structure according to claim 1, characterized in that, The stainless steel outer shell (1) and the aluminum core (2) are interference fit.

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