CN112450575A

CN112450575A - Comb tooth unit of electric heating hair straightening comb

Info

Publication number: CN112450575A
Application number: CN202011318313.3A
Authority: CN
Inventors: 于伟; 卢炎; 薛云涛
Original assignee: Shanghai Paied Technology Co ltd; Shanghai Feimeisi Network Technology Co ltd
Current assignee: Shanghai Paied Technology Co ltd; Shanghai Feimeisi Network Technology Co ltd
Priority date: 2020-08-18
Filing date: 2020-11-23
Publication date: 2021-03-09
Anticipated expiration: 2040-11-23
Also published as: CN214483596U; CN214386464U; CN112450571B; CN112401438B; CN214386480U; CN112450575B; CN112450571A; CN214386466U; CN112401438A; CN214386481U

Abstract

The invention provides a comb tooth unit of an electric heating hair straightening comb, which comprises a plurality of comb teeth which are arranged side by side and connected in an inserting manner, wherein the comb teeth are sheet-shaped and are provided with a first side surface and a second side surface which are opposite, the first side surface is provided with a bulge, and the back of the second side surface, which corresponds to the bulge, is provided with a groove; the two sides of the root of the comb teeth are respectively provided with a mounting structure for fixedly mounting the comb teeth and the comb tooth base. The comb teeth can increase the contact area with hair, and the gaps between the adjacent comb teeth are reasonably arranged, so that the hair can be conveniently inserted, the hair can be effectively clamped, and the hair straightening efficiency is improved; due to the structural design of the protrusions and the grooves, the positioning is convenient, the mounting efficiency is improved, and the stability of the plurality of comb teeth is enhanced; the bottoms of the two sides of the comb teeth are provided with slots or holes, so that the comb teeth and the comb tooth base can be conveniently installed; the root of broach sets up the mounting hole and is used for installing heating element, and installation back heating element is in the inside of a plurality of broach, and it can carry out omnidirectional heat-conduction to the broach, improves heating efficiency, reduces the heat dissipation.

Description

Comb tooth unit of electric heating hair straightening comb

Technical Field

The invention relates to the field of hair care equipment, in particular to a comb tooth unit of an electric heating hair straightening comb.

Background

The tradition is directly sent out the instrument and is mostly the straight ware of sending out of pincer-type electric plate, and the inboard of two pincer-type splint is equipped with the electrical heating board, and two electrical heating board heats, carry the hair and straighten hair, but this kind of straight ware only can send out the hair and straighten, during the in-service operation, need the comb cooperation, and the user needs one to hold straight ware and straighten hair, and another only holds the comb and comb the hair, and the operation is inconvenient, and efficiency is not high. Also some hair straightening combs that unite two into one hair straightener function and comb function have appeared among the prior art, and it is equipped with the broach portion that hot plate and integrated into one piece formed, and broach portion is including arranging a plurality of broaches on the hot plate side by side, at the interval, and during the use, the hair is arranged in the clearance between a plurality of broaches, heats the broach after the hot plate circular telegram, and the broach heats the hair again, realizes the hair straightening function. However, by adopting the arrangement mode, the contact area between the comb teeth and the heating plate is smaller, the heating efficiency of the heating plate to the comb teeth is low, the contact area between the comb teeth and the hair is smaller when the hair straightening device is used, and the hair straightening efficiency is low; when in use, the hair is easy to slide off the comb teeth; in addition, the mounting structure of broach is simple, has the problem that stability is not high, positioning accuracy is low.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and provides the comb tooth unit of the electric heating hair straightening comb, which has a stable structure and is convenient and fast to install, and can further improve the heating efficiency and the hair straightening efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

a comb tooth unit of an electric heating hair straightening comb comprises a plurality of comb teeth which are arranged side by side and connected in an inserting mode, the comb teeth are sheet-shaped and are provided with a first side face and a second side face which are opposite, protrusions are arranged on the first side face of the comb teeth, grooves are formed in the second side face of the comb teeth corresponding to the back portions of the protrusions, and the structures of the protrusions are matched with the structures of the grooves of the adjacent comb teeth, into which the protrusions extend; the comb teeth are provided with roots, tips and main body parts located between the roots and the tips along the length direction; and mounting structures for fixedly mounting the comb teeth and the comb tooth base are respectively arranged on two sides of the root of the comb teeth.

Preferably, the mounting structure comprises a first slot or hole and a second slot or hole which are arranged on two sides of the bottom of the main body part of the comb teeth.

Still preferably, the mounting structure includes flange structures provided at both sides of the root of the comb teeth.

Preferably, the root of the comb teeth is provided with a mounting hole, and the mounting hole penetrates through the root of the comb teeth.

Still preferably, the mounting holes include a first mounting hole for mounting the heating element and a second mounting hole for mounting the temperature sensor, the first mounting hole is communicated with the second mounting hole, and the first mounting hole is located below the second mounting hole.

Preferably, the number of the protrusions is two, the number of the grooves is two, and the two protrusions or the grooves are arranged between the first open groove or the open hole and the second open groove or the open hole on the two sides.

Still preferably, the protrusion height of the protrusion is greater than the depression depth of the groove.

Still preferably, a tip portion of the comb teeth has a thickness smaller than a root portion of the comb teeth, a tip portion of the comb teeth has a width smaller than a root portion of the comb teeth, and the comb teeth have a curved cross section.

Still preferably, in the main body portion of the comb teeth, the cross section of the comb teeth includes a first arc located at the central portion and two second arcs located at both sides of the first arc, and the second arcs are opposite to the bending direction of the first arcs and have a radius of curvature smaller than that of the first arcs.

Still preferably, the root portion has a thickness greater than that of the body portion, and a cross section of the root portion and a cross section of the body portion have a uniform arc shape.

Preferably, at the same height of the main body parts of the comb teeth, the distance between the first arc centers of two adjacent comb teeth is 1.1 to 1.6 times of the thickness of the comb teeth, and the distance between the second arc centers of two adjacent comb teeth is 1.2 to 1.8 times of the thickness of the comb teeth.

Preferably, the comb teeth are of a left-right symmetrical structure.

Preferably, the single comb teeth are of an integrally formed structure.

Compared with the prior art, the invention has the beneficial effects that:

1. one side surface of each comb tooth is provided with a bulge, the other side surface of each comb tooth is provided with a groove corresponding to the back of the bulge, and the bulge of the back comb tooth is embedded into the groove of the front comb tooth during installation, so that the positioning is convenient, the installation efficiency is improved, and the stability of the comb teeth is enhanced;

2. the bottoms of the two sides of the comb teeth are provided with slots or holes, so that the comb teeth and the comb tooth base can be conveniently installed;

3. the roots of the comb teeth are provided with mounting holes for mounting heating elements, and the heating elements are positioned inside the comb teeth after mounting, so that the heating elements can conduct heat to the comb teeth in an all-around manner, the heating efficiency is improved, and the heat dissipation is reduced;

4. the broach is tongue type shape, and the broach has crooked cross section, can increase with the area of contact of hair, and rationally sets up the clearance between the adjacent broach, can make things convenient for the hair to insert, can effectively press from both sides tight hair again, improves and directly sends out efficiency.

Drawings

Fig. 1 is a perspective view of a comb tooth unit of an electrothermal hair straightening comb according to embodiment 1 of the present invention;

fig. 2 is a schematic perspective view of a first side surface of comb teeth of an electrothermal hair straightening comb according to embodiment 1 of the present invention;

FIG. 3 is a schematic structural view of an electrothermal hair straightening comb according to embodiment 1 of the present invention;

FIG. 4 is a cross-sectional view taken along A-A of FIG. 3;

FIG. 5 is a sectional view of the same height of the main body parts of two adjacent comb teeth in use of the comb teeth of the electric heating hair straightening comb in embodiment 1 of the present invention;

FIG. 6 is a schematic structural view of an electric heating hair straightening comb according to embodiment 1 of the present invention, wherein the comb teeth are mounted on a comb tooth base;

FIG. 7 is a schematic structural view of an electric heating hair straightening comb according to embodiment 2 of the present invention, in which comb teeth are mounted on a comb tooth base;

FIG. 8 is a schematic structural view of an electric heating hair straightening comb according to embodiment 3 of the present invention, in which comb teeth are mounted on a comb tooth base;

fig. 9 is a schematic structural view of comb teeth of an electrothermal hair straightening comb according to embodiment 4 of the present invention.

In the figure, 10-comb unit, 100-comb, 101-first slot, 102-second slot, 103-first side, 104-second side, 105-protrusion, 106-groove, 107-first arc, 108-second arc, 109-first mounting hole, 110-second mounting hole, 111-mounting hole, 112-first flange, 113-second flange, 114-first opening, 115-second opening, 200-comb base, 201-first plug-in strip, 202-second plug-in strip.

Detailed Description

In order to further understand the objects, structures, features and functions of the present invention, the following embodiments are described in detail.

Referring to fig. 1 to 6 in combination, fig. 1 is a perspective view of a comb tooth unit of an electrothermal hair straightening comb according to embodiment 1 of the present invention; fig. 2 is a schematic perspective view showing a first side surface of a comb tooth of an electrothermal hair straightening comb according to embodiment 1 of the present invention, fig. 3 is a schematic perspective view showing a second side surface of a comb tooth of an electrothermal hair straightening comb according to embodiment 1 of the present invention, fig. 4 is a sectional view taken along a direction a-a in fig. 3, fig. 5 is a sectional view showing two adjacent comb teeth of an electrothermal hair straightening comb according to embodiment 1 of the present invention at the same height as roots of the two adjacent comb teeth in use, and fig. 6 is a schematic structural view showing a comb tooth of an electrothermal hair straightening comb according to embodiment 1 of the present invention mounted on a comb tooth base.

The comb tooth unit 10 of the electric heating hair straightening comb of the present invention includes a plurality of comb teeth 100 which are arranged side by side and are connected by insertion. The comb teeth 100 of the electric heating hair straightening comb in embodiment 1 of the present invention are sheet-shaped and have a first side surface 103 and a second side surface 104 which are opposite to each other, the first side surface 103 of the comb teeth 100 is provided with protrusions 105, the second side surface 104 of the comb teeth 100 is provided with grooves 106 corresponding to the backs of the protrusions 105, and the structures of the protrusions 105 are matched with the structures of the grooves 106 of the adjacent comb teeth into which the protrusions 105 can extend.

The comb teeth 100 have a bilaterally symmetrical structure, and when a plurality of comb teeth 100 are mounted side by side on the comb base 200 (see fig. 6), the adjacent comb teeth are coupled to each other in such a manner that the protrusions 105 of the rear comb teeth are fitted into the grooves 106, i.e., the protrusions 105 of the front comb teeth are fitted into the grooves 106 of the front comb teeth. The structural design of the protrusions 105 and the grooves 106 on the comb teeth 100 facilitates positioning when a plurality of comb teeth 100 are installed, and installation efficiency is improved; meanwhile, the upper, lower, left and right positions of the plurality of comb teeth 100 can be kept consistent, the distance between any two adjacent comb teeth 100 can be kept consistent, the installation stability of the plurality of comb teeth 100 can be enhanced, and the uniform heating of hair can be ensured.

Referring to fig. 2 and 3, in embodiment 1 of the present invention, the main body of the protrusion 105 is a cylindrical structure protruding outward from the root of the comb teeth 100, and the outer end surface of the protrusion 105 is a spherical arc surface; the groove 106 is a circular groove formed by inward recessing of the root of the comb teeth 100, the bottom surface of the groove 106 is a spherical cambered surface, and the structure of the groove 106 is matched with that of the protrusion 105. However, the present invention is not limited thereto, and in other embodiments, the structure of the protrusion 105 and the groove 106 may adopt other reasonable structural designs.

The comb teeth 100 of the electric heating hair straightening comb of the present invention are tongue-shaped, and the comb teeth 100 have a root portion, a tip portion, and a main body portion between the root portion and the tip portion along a length direction; the thickness of the tip of the comb tooth 100 is smaller than that of the root of the comb tooth 100, and the width of the tip of the comb tooth 100 is smaller than that of the root of the comb tooth 100, so that hair can be inserted conveniently; the two sides of the root of the comb teeth 100 are respectively provided with a mounting structure for fixedly mounting the comb teeth 100 and the comb base 200. Referring to fig. 1, in embodiment 1 of the present invention, the mounting structure includes a first slot 101 and a second slot 102, and the first slot 101 and the second slot 102 are respectively disposed on two sides of the root of the comb tooth 100. Referring to fig. 6, fig. 6 is a schematic structural view illustrating that comb teeth 100 of an electric heating hair straightening comb are mounted on a comb tooth base 200 according to embodiment 1 of the present invention; be equipped with on broach base 200 with first fluting 101 structure assorted first grafting strip 201, with second fluting 102 structure assorted second grafting strip 202 for on inserting broach base 200 with a plurality of broach 100 side by side, play direction and positioning action, improve the installation effectiveness. Specifically, the first slot 101 and the second slot 102 may have various structures such as a rectangle, an arc, and a trapezoid. When the comb 100 is mounted with the comb base 200, a mounting structure like "cartridge" and "magazine" is formed, facilitating the mounting and positioning of the comb 100. The mounting structure enables the comb teeth to slide along the length direction of the comb tooth base and be inserted into the comb tooth base.

Referring to fig. 2 or 3, the root of the comb teeth 100 is provided with a mounting hole 111, and the mounting hole 111 penetrates through the root of the comb teeth 100. When a plurality of broach 100 was installed side by side with the form of protruding 105 embedding recess 106, the mounting hole 111 of a plurality of broach 100 was communicate around, formed the constant head tank that is used for installing heating element, and like this, heating element is direct to be contacted with broach 100, directly carries out all-round heating from broach 100 inside, and the heating area increase is better to broach 100's heating effect.

Further, referring to fig. 2 or fig. 3, in embodiment 1 of the present invention, the mounting hole 111 is substantially in a "convex" configuration, the mounting hole 111 includes a first mounting hole 109 for mounting the heating element and a second mounting hole 110 for mounting the temperature sensor, the first mounting hole 109 is communicated with the second mounting hole 110, the first mounting hole 109 is located below the second mounting hole 110, and an opening area of the first mounting hole 109 is larger than an opening area of the second mounting hole 110. When the plurality of comb teeth 100 are mounted on the comb base 200 side by side, the first mounting holes 109 of the plurality of comb teeth 100 are communicated side by side, and the second mounting holes 110 of the plurality of comb teeth 100 are communicated side by side, so that the heating element, the temperature sensor, and the electric wire (not shown) can be conveniently mounted. In one embodiment, the heating element is a plate-shaped structure, and the heating element is installed in consecutive positioning grooves formed by the first installation holes 109 of the plurality of comb teeth 100 and used for heating the plurality of comb teeth 100; the temperature sensor and the electric wire are arranged in the wiring groove formed by the second mounting holes 110 of the comb teeth 100 and used for detecting the heating temperature of the heating element, and the control and the adjustment of the heating temperature are facilitated. After installation, be equipped with heat conduction resin between heating element and the broach, heating element can carry out direct contact heat-conduction through the root of heat conduction resin with the broach. According to the invention, the mounting structures of the heating element and the temperature sensor are arranged inside the comb teeth 110, and the heating element heats the comb teeth 100 in all directions when in use, so that the heating efficiency can be improved, and the heat dissipation can be reduced; in addition, the plurality of first mounting holes 109 communicated side by side have a guiding and positioning function on the heating element, and the plurality of second mounting holes 110 communicated side by side have a guiding and positioning function on the temperature sensor, so that the mounting efficiency can be improved.

Referring to fig. 2 or fig. 3, in embodiment 1 of the present invention, the number of the protrusions 105 is two, the number of the grooves 106 is two, and the two protrusions 105 or the grooves 106 are disposed between the first slots 101 and the second slots 102 on both sides, so as to enhance the front-back, left-right mounting stability of the comb tooth root. However, the present invention is not limited thereto, and the number and the arrangement positions of the protrusions 105 and the grooves 106 may be adjusted according to the actual situation. Further, the protrusion height of the protrusion 105 is greater than the depression depth of the groove 106 to ensure a certain gap between adjacent comb teeth, thereby facilitating the insertion of hair between the comb teeth. Specifically, in embodiment 1, the protrusion height of the protrusion 105 is 0.5 to 0.8 times the thickness of the comb tooth 100, the depression depth of the groove 106 is 0.3 to 0.6 times the thickness of the comb tooth 100, and when a plurality of comb teeth 100 are arranged side by side, the distance between any two adjacent comb teeth 100 can be kept consistent.

Referring to fig. 3 and 4 in combination, the comb teeth 100 have a curved cross-section. Specifically, in the main body portion of the comb 100, the cross section of the comb 100 includes a first arc 107 located at the central portion and two second arcs 108 located at both sides of the first arc 107, the second arcs 108 are opposite to the bending direction of the first arc 107 and the radius of curvature of the second arcs 108 is smaller than that of the first arc 107. Further, the first arc 107 curves toward the second side 104 of the comb 100 and the second arc 108 curves toward the first side 103 of the comb. The tongue-shaped structure and the curved cross-sectional structure of the comb teeth 100 facilitate hair insertion, and effectively clamp hair, increase the contact area with hair, and improve hair straightening efficiency.

Preferably, the thickness of the root portion of the comb teeth 100 is greater than that of the main body portion, and the cross section of the root portion has a uniform arc shape with that of the main body portion. Thus, the side surfaces of the wave-shaped roots of adjacent comb teeth 100 are matched and abutted with each other, so that the comb teeth 100 are more stably assembled to the comb tooth base side by side.

More preferably, at the same height of the main body of the comb teeth 100, the distance between the centers of the first arcs 107 of two adjacent comb teeth is 1.1-1.6 times the thickness of the comb teeth 100, and the distance between the centers of the second arcs 108 of two adjacent comb teeth is 1.2-1.8 times the thickness of the comb teeth 100. Referring to fig. 5, fig. 5 is a cross-sectional view of the same height of the main body parts of two

adjacent comb teeth

30, 40 in the use of the comb teeth of the electric heating hair straightening comb of embodiment 1 of the present invention; when the thickness of the main body part of the comb teeth 30 at the height is recorded as h1, the distance between the centers of the first arcs 107 of the two adjacent comb teeth (the comb teeth 30 and the comb teeth 40) is recorded as h2, and the distance between the centers of the second arcs 108 of the two adjacent comb teeth (the comb teeth 30 and the comb teeth 40) is recorded as h3, then h2 is 1.1-1.6 times of h1, and h3 is 1.2-1.8 times of h 1. Specifically, for example, at the same height, the thickness h1=4mm of the main body portion of the comb tooth 40, the distance h2=5.2mm between the comb tooth 30 and the center of the first arc 107 of the comb tooth 40, and the distance h3=6mm between the comb tooth 30 and the center of the second arc 108 of the comb tooth 40. Due to the arrangement mode, the hair can be conveniently inserted, the hair can be effectively clamped, the hair entering the comb teeth 100 is attached to the heated comb teeth as much as possible to be heated, and the hair straightening efficiency is improved.

Preferably, single broach 100 is the integrated into one piece structure, and broach 100 adopts the metal material that the heat conductivity is good, can improve heat conduction efficiency.

Referring to fig. 7, fig. 7 is a schematic structural view illustrating that comb teeth of an electrothermal hair straightening comb are mounted on a comb tooth base in embodiment 2 of the present invention; in embodiment 2 of the present invention, the mounting structure for fixedly mounting the comb teeth and the comb tooth base includes flange structures provided on both sides of the root of the comb teeth. As shown in fig. 7, the two sides of the root of the comb 100 are respectively provided with a first flange 112 and a second flange 113, and the comb base 200 is provided with a slot structure corresponding to the first flange 112 and the second flange 113, so that the comb 100 can be conveniently inserted into the comb base 200, and the installation efficiency can be improved. The mounting holes 111 on the comb teeth 100 comprise first mounting holes 109 for mounting the heating elements and second mounting holes 110 for mounting the temperature sensors, and the heating elements conduct heat to the comb teeth 100 in all directions during use, so that the heating efficiency can be improved, and the heat dissipation is reduced.

Referring to fig. 8, fig. 8 is a schematic structural view illustrating that comb teeth of an electrothermal hair straightening comb are mounted on a comb tooth base according to embodiment 3 of the present invention; in embodiment 3 of the present invention, the mounting structure for fixedly mounting the comb teeth and the comb tooth base includes openings provided on both sides of the root of the comb tooth. As shown in fig. 8, two sides of the root of the comb 100 are respectively provided with a first opening 114 and a second opening 115, the first opening 114 and the second opening 115 are arc-shaped, and a first inserting strip 203 and a second inserting strip 204 corresponding to the first opening 114 and the second opening 115 are arranged on the comb base 200, so that the plurality of comb 100 can be conveniently inserted into the comb base 200 side by side.

Referring to fig. 9, fig. 9 is a schematic structural view of comb teeth of an electrothermal hair straightening comb in embodiment 4 of the present invention. In embodiment 4 of the present invention, rectangular mounting holes 111 are formed at the root of the comb teeth 100 for mounting heating elements. The comb teeth with the structure can be arranged at the position where temperature monitoring is not needed in a plurality of comb tooth arrays without mounting holes of temperature sensors.

In conclusion, the invention provides the comb teeth of the electric heating hair straightening comb, the comb teeth are arranged in the shape of the tongue, the comb teeth are provided with the curved cross sections, the contact area with hair can be increased, the gaps between the adjacent comb teeth are reasonably arranged, the hair can be conveniently inserted, the hair can be effectively clamped, and the hair straightening efficiency is improved; one side surface of each comb tooth is provided with a bulge, the other side surface of each comb tooth is provided with a groove corresponding to the back of the bulge, and the bulge of the back comb tooth is embedded into the groove of the front comb tooth during installation, so that the positioning is convenient, the installation efficiency is improved, and the stability of the comb teeth is enhanced; the bottoms of the two sides of the comb teeth are provided with slots or holes, so that the comb teeth and the comb tooth base can be conveniently installed; the root of broach sets up the mounting hole and is used for installing heating element, and installation back heating element is in the inside of a plurality of broach, and it can carry out omnidirectional heat-conduction to the broach, improves heating efficiency, reduces the heat dissipation.

The present invention has been described in relation to the above embodiments, which are only exemplary of the implementation of the present invention. It should be noted that the disclosed embodiments do not limit the scope of the invention. Rather, it is intended that all such modifications and variations be included within the spirit and scope of this invention.

Claims

1. The utility model provides a broach unit of electric heat hair straightening comb which characterized in that: the comb tooth unit comprises a plurality of comb teeth which are arranged side by side and connected in an inserting manner, the comb teeth are sheet-shaped and are provided with a first side surface and a second side surface which are opposite, the first side surface of the comb teeth is provided with protrusions, the second side surface of the comb teeth is provided with grooves corresponding to the back parts of the protrusions, and the structures of the protrusions are matched with the structures of the grooves of the adjacent comb teeth into which the protrusions extend; the comb teeth are provided with roots, tips and main body parts located between the roots and the tips along the length direction; and mounting structures for fixedly mounting the comb teeth and the comb tooth base are respectively arranged on two sides of the bottom of the comb teeth.

2. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 1, wherein: the mounting structure comprises a first slot or an opening and a second slot or an opening which are arranged on two sides of the bottom of the main body part of the comb teeth.

3. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 1, wherein: the mounting structure comprises flange structures arranged on two sides of the root of the comb teeth.

4. The comb tooth unit of an electrothermal hair straightening comb according to claim 1, 2 or 3, wherein: the root of broach is equipped with the mounting hole, the mounting hole link up the root of broach.

5. The comb tooth unit of the electrothermal hair straightening comb according to claim 4, wherein: the mounting hole comprises a first mounting hole used for mounting the heating element and a second mounting hole used for mounting the temperature sensor, the first mounting hole is communicated with the second mounting hole, and the first mounting hole is positioned below the second mounting hole.

6. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 2, wherein: the number of the bulges is two, the number of the grooves is two, and the two bulges or the grooves are arranged between the first open slot or the open hole and the second open slot or the open hole on the two sides.

7. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 1, wherein: the protruding height of the protrusion is greater than the recessed depth of the groove.

8. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 1, wherein: the thickness of the tip of the comb tooth is smaller than the thickness of the root of the comb tooth, the width of the tip of the comb tooth is smaller than the width of the root of the comb tooth, and the comb tooth has a curved cross section.

9. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 8, wherein: in the main part of broach, the cross section of broach includes the first arc that is located central part and is located two second arcs of first arc both sides, the second arc with first arc's crooked opposite direction just the second curved radius of curvature is less than first curved radius of curvature.

10. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 9, wherein: the thickness of the root portion is greater than that of the body portion, and the cross section of the root portion and the cross section of the body portion have a uniform arc shape.

11. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 9, wherein: at the same height of the main body parts of the comb teeth, the distance between the first arc centers of two adjacent comb teeth is 1.1-1.6 times of the thickness of the comb teeth, and the distance between the second arc centers of two adjacent comb teeth is 1.2-1.8 times of the thickness of the comb teeth.

12. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 1, wherein: the comb teeth are in a bilateral symmetry structure.

13. The comb tooth unit of the electrothermal hair straightening comb as claimed in claim 1, wherein: the single comb tooth is of an integrally formed structure.