PTC heating element structure of a curling iron and manufacturing method thereof

Abstract

The present invention relates to a heating device, and in particular to a PTC heating element structure used in a curling iron. The device comprises an outer sleeve, a PTC bracket, and a PTC heating element. The PTC bracket comprises a pressing plate and a supporting plate. Both sides of the pressing plate extend upward to form a supporting plate. A reinforcing rib is provided on one side of the lower surface of the pressing plate, and a reinforcing rib groove is provided on the other side. When two PTC brackets are combined with each other, the reinforcing rib and the reinforcing rib groove are interlocked, forming a PTC gap between the pressing plate, the supporting plate, and the reinforcing rib groove. A PTC heating element is placed in the PTC gap, and a temperature control device for detecting temperature is also provided in the PTC gap. The beneficial effects of the present invention are: high thermal conductivity, uniform heat transfer, close proximity of the temperature control device to the PTC heating element, and higher detection accuracy.

Description

Technical Field

[0001] The present invention relates to a heating device, in particular to a PTC heating element structure used in a curling rod and a manufacturing method thereof. Background Art

[0002] In existing curling iron heating devices, PTC heating plates are already widely used as safe heating devices in the industry. However, the PTC brackets on both sides of the PTC heating plates are typically formed by stamping the edges of aluminum sheets. This has low rigidity and is easily deformed during the pipe installation process. Gaps between the aluminum sheet and the outer sleeve reduce the heat transfer efficiency between the aluminum sheet and the outer sleeve, resulting in uneven heat transfer across the outer sleeve. If stronger stainless steel is used as the heat conducting structure, a stamping process would be required during the production of the PTC brackets. Although stainless steel is sufficiently rigid, pipe installation is difficult and the production process is very complex.

[0003] In the existing curling iron heating element structure, the temperature control device used to detect and monitor the temperature is usually set on one side of the PTC heating element. After being wrapped together with a wrapping film, it is clamped between two PTC brackets. Although this design can reduce the gap between the heat-conducting structures, it reduces the temperature detection accuracy of the temperature control device on the main heating part of the PTC heating element, posing a safety hazard during use. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a PTC heating element structure used in a curling iron with a stable structure, high thermal conductivity, uniform heat transfer, and accurate temperature control detection accuracy.

[0005] In order to achieve the above-mentioned objectives, the present invention provides a PTC heating element structure for a curling iron, comprising an outer sleeve, a PTC bracket, and a PTC heating sheet. The PTC heating sheet is sandwiched between the PTC brackets, and the outer sleeve is sleeved on the outside of the two PTC brackets. The PTC bracket includes a pressing sheet and a supporting sheet. Both sides of the pressing sheet extend upward to form a semicircular supporting sheet. The semicircular supporting sheet can be well attached to the inner wall of the circular outer sleeve. By improving the tightness of the connection between the PTC bracket and the outer sleeve, the thermal conductivity efficiency of the curling iron can be improved. If necessary, the gap therebetween can be filled with thermal conductive material to further improve the thermal conductivity.

[0006] The lower surface of the pressing plate is provided with a reinforcing rib on one side and a reinforcing rib groove on the other side. The reinforcing rib groove and the reinforcing rib can improve the rigidity of the pressing plate, preventing the pressing plate from being twisted and deformed due to insufficient strength during pipe installation. When the lower surfaces of the two PTC brackets are assembled, the reinforcing rib and the reinforcing rib groove interlock with each other, forming a PTC gap between the pressing plate and the reinforcing rib groove.

[0007] A PTC heating sheet is placed in the PTC gap, and a temperature control device for detecting temperature is also provided in the PTC gap. The temperature control device and the PTC heating sheet are wrapped into a whole by wrapping a film. The wrapping film is usually made of a polyimide film, the surface of which is coated with F46 polyperfluoroethylene propylene emulsion and finally made by sintering. The film has good thermal conductivity and insulation and temperature resistance. It has a self-adhesive effect at high temperatures, but does not have a self-adhesive function at room temperature. After wrapping the PTC heating sheet and the temperature control device, the wrapping of the PTC heating sheet and the temperature control device can be completed by heating and sealing.

[0008] As a further improvement of the present invention, a groove is provided inwardly on the surface of the pressing tablet.

[0009] As a further improvement of the present invention, the temperature control device is placed in the groove. The temperature control device arranged in the groove is more conducive to contacting and monitoring the main heating surface, and can more directly sense the temperature of the PTC heating plate, which is conducive to improving the temperature control accuracy and effect of the curling iron.

[0010] As a further improvement of the present invention, the internal gap size of the PTC gap is adapted to the size of the PTC heating sheet, and the close contact can effectively improve the heat transfer efficiency of the PTC bracket to the PTC heating sheet.

[0011] As a further improvement to the present invention, the semicircular support sheet is provided with a notch. When the heating element is too large, the distance between the two PTC brackets is too large to fit into the outer sleeve. This notch can be used to adjust the angle and size of the support sheet. Similarly, when the outer sleeve has a small diameter, the notch can be used to adjust the shape of the PTC bracket to match the outer sleeve's dimensions.

[0012] As a further improvement to the present invention, the connection between the pressing plate and the supporting plate has a rounded corner structure. Compared to a sharp corner structure, a rounded corner structure has higher heat transfer efficiency. Furthermore, if the outer sleeve diameter is too small during installation, the PTC bracket needs to be compressed. This rounded corner structure provides more compression space than a sharp corner structure and prevents distortion of the flat pressing plate. The rounded corner structure also has a screw hole on the inside. Once the PTC bracket is installed in the outer sleeve, the sealing screw at the top of the curling iron can be fixedly connected to the PTC bracket, thereby improving the overall strength of the curling iron.

[0013] As a further improvement to the present invention, the PTC bracket is made of zinc alloy or aluminum alloy. Compared to stainless steel, both aluminum alloy and zinc alloy have better thermal conductivity. The thermal conductivity of aluminum is 204 / W·(m·K), and the thermal conductivity of zinc is 116W / (m·K), while the thermal conductivity of stainless steel is only 14 / W·(m·K). Therefore, aluminum alloy has better heat transfer performance than stainless steel. Compared to copper, which has better thermal conductivity, aluminum alloy and zinc alloy are cheaper and lighter, and also have better hardness and are less prone to deformation.

[0014] As a further improvement of the present invention, the PTC bracket is integrally formed and cut according to the required length. The structures of the upper and lower PTC brackets are completely consistent. They can be used by rotating them. Using this processing technology, the PTC bracket can be efficiently produced through a stretching mold. Then, according to the actual required length, the profile can be cut to obtain a PTC bracket that matches the length of the PTC heating plate.

[0015] The manufacturing method of the PTC heating element structure of the curling iron comprises the following steps:

[0016] S1: According to the size of the outer sleeve of the curling iron to be produced, the size parameters of the PTC bracket are set, and a longer PTC bracket is produced in one step through the profile stretching equipment;

[0017] S2: According to the length of the PTC bracket required in the curling iron, the PTC bracket produced in S1 is cut into PTC brackets of the same length;

[0018] S3: Assemble the two cut PTC brackets into a cylindrical structure by rotating them together, aligning the reinforcing ribs with the reinforcing rib grooves, and place the PTC heating element and temperature control device wrapped together in the PTC gap between the two PTC brackets 2;

[0019] S4: Using the tube-installing equipment, the assembled PTC bracket, the PTC heating element and the temperature control device inside it are pressed into the outer tube of the curling iron;

[0020] S5: Use the tube shrinking device to compress the diameter of the outer tube of the curling iron so that the outer tube and the PTC bracket are in close contact with each other, thereby improving the heat conduction efficiency of the curling iron.

[0021] As a further improvement of the above method, step S3 further includes: placing the temperature control device in the middle of the PTC gap and embedding it in the groove.

[0022] The beneficial effects of the present invention are as follows: when the two PTC brackets are combined with each other, the gap between the reinforcing rib groove and the pressing plate can fit tightly with the PTC heating plate, thereby improving the thermal conductivity of the PTC heating plate; the temperature control device is arranged in the middle part of the pressing plate, thereby improving the temperature sensing accuracy of the temperature control device to the PTC heating plate; the connection between the support plate and the pressing plate uses a rounded structure, which can reduce heat transfer loss; during the pipe installation process, the rounded structure can have a larger compression space and will not cause the pressing plate to twist and deform; the applicable outer sleeve size is wider; the use of a structure with all four sides fitted with the PTC heating plate can better absorb and transfer the heat of the PTC heating plate; the PTC bracket is made by an one-piece molding process, and only needs to be cut to the required length to be installed in the outer sleeve; no folding or stamping process is required, the production efficiency is high, and the enterprise's labor costs are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] For ease of explanation, the present invention is described in detail with reference to the following preferred embodiments and the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the PTC heating element structure inside the curling iron;

[0025] Figure 2 It is a cross-sectional view of the PTC bracket;

[0026] Figure 3 This is a cross-sectional view of the PTC bracket assembly;

[0027] Figure 4 This is a cross-sectional diagram of the PTC heating element structure;

[0028] Figure 5 This is a schematic diagram of the PTC heating element structure with grooves inside the curling iron;

[0029] Figure 6 This is a cross-sectional view of the PTC bracket with screw holes;

[0030] In the figure: 1-outer sleeve, 2-PTC bracket, 21-pressing plate, 22-supporting plate, 221-notch, 23-reinforcement rib, 24-reinforcement rib groove, 25-PTC gap, 26-groove, 27-temperature control device, 28-screw hole, 3-PTC heating plate. DETAILED DESCRIPTION

[0031] like Figure 1As shown, a PTC heating element structure of a curling iron includes an outer sleeve 1, a PTC bracket 2 and a PTC heating piece 3, the PTC heating piece 3 is clamped between the PTC brackets 2, the outer sleeve 1 is sleeved on the outside of the two PTC brackets 2, the PTC bracket 2 includes a pressing piece 21 and a supporting piece 22, both sides of the pressing piece 21 extend upward to form a semicircular supporting piece 22; one side of the lower surface of the pressing piece 21 is provided with a reinforcing rib 23, and the other side is provided with a reinforcing rib groove 24. When the lower surfaces of the two PTC brackets 2 are combined with each other, the reinforcing rib 23 and the reinforcing rib groove 24 are interlocked with each other, and a PTC gap 25 is formed between the pressing piece 21 and the reinforcing rib groove 24; the PTC heating piece 3 is placed in the PTC gap 25, and the PTC gap 25 is also provided with a temperature control device 27 for detecting temperature. The temperature control device 27 and the PTC heating piece 3 are wrapped into a whole by wrapping a film.

[0032] like Figure 2 、 3 As shown, a groove 26 is provided inwardly on the surface of the pressing sheet 21 .

[0033] like Figure 4 、 5 As shown, the temperature control device 27 is placed in the groove 26 .

[0034] like Figure 4 As shown, the internal gap size of the PTC gap 25 is adapted to the size of the PTC heating sheet 3 .

[0035] like Figure 2 、 3 As shown, the semicircular supporting piece 22 is provided with a notch 221 .

[0036] like Figure 6 As shown, the connection between the pressing plate 21 and the supporting plate 22 is a rounded structure, and a screw hole 28 is provided on the inner side of the rounded structure.

[0037] The PTC bracket 2 is made of zinc alloy or aluminum alloy.

[0038] The PTC bracket 2 is integrally formed and cut to the required length.

[0039] The present invention also provides two embodiments of the assembly and production of PTC heating element structures:

[0040] Example 1:

[0041] S1: According to the size of the outer sleeve 1 of the curling iron to be produced, the size parameters of the PTC bracket 2 are set, and a longer PTC bracket 2 is produced in one step through a profile stretching device;

[0042] S2: According to the length of the PTC bracket 2 required in the curling iron, the PTC bracket 2 produced in one step in S1 is cut into PTC brackets 2 of the same length;

[0043] S3: Assemble the two cut PTC brackets 2 into a cylindrical structure by rotating them together, aligning the reinforcing ribs 23 with the reinforcing rib grooves 24, and place the PTC heating element 3 and the temperature control device 27 in the PTC gap 25 between the two PTC brackets 2;

[0044] S4: Using a tube-installing device, the assembled PTC bracket 2 and the PTC heating element 3 and temperature control device 27 therein are pressed into the outer sleeve 1 of the curling iron;

[0045] S5: Using a tube shrinking device, the diameter of the outer tube 1 of the curling iron is compressed so that the outer tube 1 and the PTC bracket 2 are in close contact with each other, thereby improving the heat conduction efficiency of the curling iron.

[0046] Example 2:

[0047] S1: According to the size of the outer sleeve 1 of the curling iron to be produced, the size parameters of the PTC bracket 2 are set, and a longer PTC bracket 2 is produced in one step through a profile stretching device;

[0048] S2: According to the length of the PTC bracket 2 required in the curling iron, the PTC bracket 2 produced in one step in S1 is cut into PTC brackets 2 of the same length;

[0049] S3: Assemble the two cut PTC brackets 2 into a cylindrical structure by rotating them together, aligning the reinforcing ribs 23 with the reinforcing rib grooves 24, placing the PTC heating element 3 in the PTC gap 25 between the two PTC brackets 2, and embedding the temperature control device 27 into the groove 26;

[0050] S4: Using a tube-installing device, the assembled PTC bracket 2 and the PTC heating element 3 and temperature control device 27 therein are pressed into the outer sleeve 1 of the curling iron;

[0051] S5: Using a tube shrinking device, the diameter of the outer tube 1 of the curling iron is compressed so that the outer tube 1 and the PTC bracket 2 are in close contact with each other, thereby improving the heat conduction efficiency of the curling iron.

[0052] The heating element structure and production method described in this embodiment are not limited to the curling iron structure. Any PTC heating rod structure that requires uniform heating can be produced using the structure and method described in the present invention.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A PTC heating element structure for a curling iron, comprising an outer sleeve (1), a PTC bracket (2) and a PTC heating sheet (3), wherein the PTC heating sheet (3) is held between the PTC brackets (2), and the outer sleeve (1) is sleeved onto the outside of the two PTC brackets (2), characterized in that: The PTC bracket (2) comprises a pressing plate (21) and a supporting plate (22), and both sides of the pressing plate (21) extend upward to form a semicircular arc-shaped supporting plate (22); A reinforcing rib (23) is provided on one side of the lower surface of the pressing plate (21), and a reinforcing rib groove (24) is provided on the other side. When the lower surfaces of the two PTC brackets (2) are combined with each other, the reinforcing rib (23) and the reinforcing rib groove (24) are interlocked, forming a PTC gap (25) between the pressing plate (21) and the reinforcing rib groove (24). A PTC heating sheet (3) is placed in the PTC slit (25), and a temperature control device (27) for detecting temperature is also provided in the PTC slit (25), wherein the temperature control device (27) and the PTC heating sheet (3) are wrapped with a film to form a whole; a groove (26) is provided inwardly on the surface of the pressing sheet (21); the temperature control device (27) is placed in the groove (26); and a notch (221) is provided on the semicircular arc-shaped supporting sheet (22).

2. The PTC heating element structure of a curling iron according to claim 1, characterized in that: The internal gap size of the PTC slit (25) is compatible with the size of the PTC heating plate (3).

3. The PTC heating element structure of a curling iron according to claim 1, characterized in that: The connection between the pressing plate (21) and the supporting plate (22) is a rounded structure, and a screw hole (28) is provided on the inner side of the rounded structure.

4. The PTC heating element structure of a curling iron according to claim 1, characterized in that: The PTC bracket (2) is made of zinc alloy or aluminum alloy.

5. The PTC heating element structure of a curling iron according to claim 1, characterized in that: The PTC bracket (2) is an integrally formed structure and is cut according to required length.

6. A method for manufacturing a PTC heating element structure of a curling iron according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: according to the size of the outer sleeve (1) of the curling iron to be produced, the size parameters of the PTC bracket (2) are set, and a longer PTC bracket (2) is produced by one-step molding through a profile stretching device; S2: according to the length of the PTC bracket (2) required in the curling iron, the PTC bracket (2) produced by one-step molding in S1 is cut into PTC brackets (2) of the same length; S3: Assemble the two cut PTC brackets (2) into a cylindrical structure by rotating them together, aligning the reinforcing ribs (23) and the reinforcing rib grooves (24) with each other, placing the PTC heating sheet (3) in the PTC gap (25) between the two PTC brackets 2, and embedding the temperature control device (27) into the groove (26); S4: Using a tube-installing device, the assembled PTC bracket (2) and the PTC heating element (3) and temperature control device (27) therein are pressed into the outer sleeve (1) of the curling iron; S5: The outer sleeve (1) of the curling iron is compressed by a tube shrinking device so that the outer sleeve (1) and the PTC bracket (2) are closely attached to each other, thereby improving the heat conduction efficiency of the curling iron.

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