Ignition needle, burner and hob

Abstract

The utility model relates to the field of kitchen utensils, and discloses particularly an ignition needle, a burner and a cooking utensil, which comprises: a ceramic body and a metal needle; the metal needle is inserted into the central hole of the ceramic body, the head of the metal needle is exposed from the central hole, and the hole edge of the one end of the central hole close to the head is a rounded corner. The metal needle of the ignition needle is inserted into the central hole of the ceramic body, the hole edge of the one end of the central hole close to the head is a thermal stress concentration position, the hole edge is set to a rounded corner, so that the thermal stress concentration can be avoided, and the ignition needle can be prevented from cracking.

Description

Technical Field

[0001] This utility model relates to the field of kitchen utensils, and in particular to an ignition needle, a burner, and a stove. Background Technology

[0002] The ignition needle of a stove is usually composed of a ceramic body and an electrode needle. The electrode needle is usually made of a high-resistance heating alloy, and the ceramic body is A-95 ceramic. The thermal expansion coefficient of the electrode needle is usually higher than that of the ceramic body, and the electrode needle and the ceramic body are usually tightly fitted together.

[0003] Analysis of returned ignition needles on the market revealed that cracked ignition needles accounted for approximately 60% of the total.

[0004] Analysis of the mechanism of ignition needle cracking revealed that:

[0005] 1. Differences between ceramics and metals:

[0006] The outer ceramic material of the ignition needle has a different coefficient of thermal expansion than the internal high-resistance heating alloy. During frequent ignition and high-temperature operation, the stress generated by the thermal expansion of the metal alloy is constrained by the highly rigid ceramic shell, leading to microcracks on the ceramic surface.

[0007] 2. Long-term accumulation:

[0008] After multiple thermal cycles (ignition-cooling), the microcracks gradually expand and connect, eventually causing the ceramic shell to crack.

[0009] 3. The inherent brittleness of ceramic materials:

[0010] Brittle fracture: Ceramics are brittle materials and are sensitive to surface defects (such as scratches and pores). During long-term use, the ceramic surface may develop tiny defects due to mechanical impact, improper cleaning, or high temperatures, which can become crack initiation points.

[0011] 4. Manufacturing process issues:

[0012] Poor ceramic sintering processes (such as insufficient sintering temperature or excessive impurities in raw materials) can lead to the presence of pores or microcracks inside the ceramic, reducing its mechanical strength.

[0013] This disclosure improves the problem of ignition needle cracking by starting with the structural design of the ignition needle. Utility Model Content

[0014] The technical problem to be solved by this utility model is to overcome the defect of easy cracking of the ignition needle in the prior art, and to provide an ignition needle, burner and stove.

[0015] The present invention solves the above-mentioned technical problems through the following technical solution:

[0016] An ignition needle comprising: a ceramic body and a metal needle;

[0017] The metal needle is inserted into the central hole of the ceramic body, with the head of the metal needle protruding from the central hole, and the edge of the central hole near the head is rounded.

[0018] In this design, the metal needle of the ignition needle is inserted into the central hole of the ceramic body. The edge of the central hole near the head is a point of thermal stress concentration. By setting the edge of the hole to a rounded corner, thermal stress concentration can be avoided, thereby preventing the ignition needle from cracking.

[0019] Preferably, the head has a shape that gradually tapers outwards.

[0020] Preferably, the large-diameter end of the head protrudes radially outward and covers the rounded corner of the rim of the central hole.

[0021] In this design, the large-diameter end of the metal needle head of the electrode needle protrudes radially outward, covering the edge of the central hole, thereby reducing the impact of the metal needle expansion on the ceramic body.

[0022] Preferably, the head is frustum-shaped.

[0023] Preferably, the radius R2 of the edge of the central hole near the head satisfies: 0.3 mm ≤ R2 ≤ 0.5 mm.

[0024] Preferably, the outer edge of the ceramic body near the head end is rounded.

[0025] Preferably, the radius R1 of the rounded corner of the outer edge of the ceramic body near the head satisfies: 0.5mm ≤ R1 ≤ 1 mm.

[0026] Preferably, the end of the ceramic body near the head has a shape that gradually tapers toward the head.

[0027] A burner comprising an ignition needle as described above.

[0028] A stove that includes a burner as described above.

[0029] The positive and progressive effects of this invention are as follows: the metal needle of the ignition needle is inserted into the central hole of the ceramic body. The edge of the central hole near the head is a point of thermal stress concentration. By making this edge rounded, thermal stress concentration can be avoided, thereby preventing the ignition needle from cracking. Burners and stoves with ignition needles have the same effect as described above. Attached Figure Description

[0030] Figure 1This is a three-dimensional structural diagram of an ignition needle according to an embodiment of the present invention.

[0031] Figure 2 This is a schematic cross-sectional view of an ignition needle according to an embodiment of the present invention.

[0032] Figure 3 for Figure 2 An enlarged structural diagram of part A in the diagram.

[0033] Explanation of reference numerals in the attached figures:

[0034] Ignition needle 100

[0035] Metal needle 110

[0036] Head 111

[0037] Ceramic body 120

[0038] First rounded corner O1

[0039] Second rounded corner O2

[0040] Center hole 123

[0041] 125 ring protrusions

[0042] Annular groove 126 Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and by way of embodiments, but the present invention is not limited to the scope of the embodiments thereon.

[0044] like Figure 1-3 As shown, this embodiment provides an ignition needle 100, which includes a ceramic body 120 and a metal needle 110.

[0045] A metal needle 110 is inserted into the central hole 123 of the ceramic body 120, with the head 111 of the metal needle 110 protruding from the central hole 123. The edge of the central hole 123 near the head 111 is rounded. This rounded corner is called the "first rounded corner O1".

[0046] The metal needle 110 of the ignition needle 100 is inserted into the central hole 123 of the ceramic body 120. The edge of the central hole 123 near the head 111 is a place where thermal stress is concentrated. By setting the edge of the hole to a rounded corner, thermal stress concentration can be avoided, thereby preventing the ignition needle 100 from cracking.

[0047] like Figure 2 As shown, Figure 2 The markings "up" and "down" correspond to the orientation of the ignition needle 100 when it is normally in use. In the following description, all will be referred to as "up". Figure 2 Describe the indicated direction.

[0048] The head 111 of the metal needle 110 has a shape that gradually tapers outwards. Here, "outwards" refers to the shape towards the outside of the central hole 123, that is... Figure 2 Above the middle.

[0049] The large-diameter end of the head 111 protrudes radially outward and covers the rounded corner of the edge of the central hole 123. That is, the lower end of the head 111 protrudes radially outward and covers the first rounded corner O1. Here, "radial" refers to the direction radiating outward with the axis of the metal needle 110 as the center.

[0050] The large-diameter end of the head 111 of the metal needle 110 of the electrode needle protrudes radially outward and covers the edge of the central hole 123, thereby reducing the effect of the expansion of the metal needle 110 on the ceramic body 120.

[0051] In other embodiments, the head 111 of the metal needle 110 may also be indistinguishable from other parts of the metal needle 110, i.e., the metal needle 110 is generally a cylindrical structure with a uniform diameter.

[0052] In this embodiment, the head 111 is frustum-shaped. However, the present invention is not limited to this; in other embodiments, the head 111 may also be other shapes that can achieve normal ignition function.

[0053] The outer edge of the ceramic body 120 near the head 111 is rounded; this rounded corner is called the "second rounded corner O2". Figure 2 As shown, the second rounded corner O2 is formed on the outer peripheral edge of the upper end of the ceramic body 120.

[0054] The upper end of the ceramic body 120, which is near the head 111, has a shape that gradually tapers toward the head 111.

[0055] The ceramic body 120 has an annular protrusion 125 at its midpoint in the vertical direction. The lower end of the ceramic body 120 has an annular groove 126. Both the annular protrusion 125 and the annular groove 126 are for facilitating the installation of the ceramic body 120.

[0056] The metal needle 110 has a three-section structure in general. The upper part is a frustum structure. The diameter of the upper middle part is approximately the same as the diameter of the central hole 123 of the ceramic body 120, so as to tightly install the metal needle 110 relative to the central hole 123. The middle and lower middle parts have smaller diameters than the upper middle part.

[0057] The ceramic body 120 has a receiving groove at its lower end, and the lower end of the metal pin 110 is placed in the receiving groove to facilitate wiring.

[0058] A simulation was performed on the needle structure of the ignition needle 100, and the following data were obtained:

[0059] needle structure R1 (mm) R2 (mm) Remark Maximum stress (MPa) Location of maximum stress original 1 0 569 O2 1 1 0.1 677 O2 2 1 0.2 633 O2 3 1 0.3 393 O2 4 0.5 0.5 333 O2 5 0.5 0.5 Needle structure drip steady state 299 At a certain distance from the upper end of the ceramic body 120 6 1 0 110 without metal needles 9.4 126 annular grooves

[0060] In needle structure 6, no metal needle 110 is installed, only ceramic body 120 is used as a comparative example.

[0061] In the needle structure with the metal needle 110 installed, the ignition needle 100 is subjected to a large stress.

[0062] In needle structure 5, the state of the needle structure being heated to a high temperature in the burner and subjected to cold water impact is simulated. Under the state of cold water impact, needle structure 5 is still relatively stable.

[0063] The maximum stress that the needle structure 3-5 can withstand is less than 400 MPa.

[0064] The radius R2 of the fillet of the center hole 123, i.e. the second fillet O2, satisfies: 0.3 mm ≤ R2 ≤ 0.5 mm.

[0065] Within this range, the maximum stress borne by the ignition needle 100 is less than 400 MPa, which can effectively prevent the ignition needle 100 from cracking.

[0066] The radius R1 of the rounded corner O1 of the outer edge of the ceramic body 120 near the head 111, i.e. the first rounded corner O1, satisfies: 0.5 mm ≤ R1 ≤ 1 mm.

[0067] This embodiment also provides a burner, which includes the ignition needle 100 as described above.

[0068] This embodiment also provides a stove that includes the burner described above.

[0069] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0070] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. An ignition needle, characterized in that, It includes: Ceramic body and metal needle; The metal needle is inserted into the central hole of the ceramic body, with the head of the metal needle protruding from the central hole, and the edge of the central hole near the head is rounded.

2. The ignition needle as described in claim 1, characterized in that, The head has a shape that gradually tapers outwards.

3. The ignition needle as described in claim 2, characterized in that, The large-diameter end of the head protrudes radially outward and covers the rounded corner of the rim of the central hole.

4. The ignition needle as described in claim 2, characterized in that, The head is truncated cone-shaped.

5. The ignition needle as described in claim 1, characterized in that, The radius R2 of the fillet of the edge of the central hole near the head satisfies: 0.3 mm ≤ R2 ≤ 0.5 mm.

6. The ignition needle as described in claim 1, characterized in that, The outer edge of the ceramic body near the head end is rounded.

7. The ignition needle as described in claim 6, characterized in that, The radius R1 of the rounded corner of the outer edge of the ceramic body near the head satisfies: 0.5 mm ≤ R2 ≤ 1 mm.

8. The ignition needle as described in claim 1, characterized in that, The ceramic body has a shape that gradually tapers toward the head at one end near the head.

9. A burner, characterized in that, It includes the ignition needle as described in any one of claims 1-8.

10. A stove, characterized in that, It includes the burner as described in claim 9.

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