Needle-shaped heating element and aerosol-forming device

Abstract

A needle-shaped heating element includes: an electrically conductive outer tube; and a heating circuit and a temperature measurement circuit arranged in the outer tube. One electrode of the heating circuit and one electrode of the temperature measurement circuit are both electrically connected to the outer tube. In an embodiment, the heating circuit includes a metal positive temperature coefficient (PTC) material.

What is claimed is: 
     
         1 . A needle-shaped heating element, comprising:
 an electrically conductive outer tube; and   a heating circuit and a temperature measurement circuit arranged in the outer tube,   wherein one electrode of the heating circuit and one electrode of the temperature measurement circuit are both electrically connected to the outer tube.   
     
     
         2 . The heating element of  claim 1 , wherein the heating circuit comprises a metal positive temperature coefficient (PTC) material. 
     
     
         3 . The heating element of  claim 2 , wherein a temperature coefficient of resistance of the heating circuit is 1500-3500 ppm. 
     
     
         4 . The heating element of  claim 1 , wherein the temperature measurement circuit comprises a metal positive temperature coefficient (PTC) material, or the temperature measurement circuit comprises a thermocouple structure. 
     
     
         5 . The heating element of  claim 1 , further comprising:
 a first electrode lead electrically connected to the outer tube.   
     
     
         6 . The heating element of  claim 5 , wherein the first electrode lead is welded to an outer side of a bottom of the outer tube. 
     
     
         7 . The heating element of  claim 1 , further comprising:
 a needle embedded in a top of the outer tube.   
     
     
         8 . The heating element of  claim 7 , wherein the one electrode of the heating circuit and the one electrode of the temperature measurement circuit are both press-fit between the needle and the outer tube so as to electrically connect to the outer tube. 
     
     
         9 . The heating element of  claim 7 , wherein the needle comprises a columnar insertion portion embedded in the outer tube and a conical guide portion connected above the insertion portion. 
     
     
         10 . The heating element of  claim 1 , further comprising:
 an insulating rod arranged in the outer tube,   wherein the heating circuit and the temperature measurement circuit are wound outside the insulating rod.   
     
     
         11 . The heating element of  claim 10 , wherein the heating circuit is arranged on an outer layer of the temperature measurement circuit. 
     
     
         12 . The heating element of  claim 11 , wherein an insulating layer is formed between the heating circuit and the temperature measurement circuit by dipping or spraying. 
     
     
         13 . The heating element of  claim 1 , further comprising:
 a second electrode lead electrically connected to an other electrode of the heating circuit and;   a third electrode lead electrically connected to an other electrode of the temperature measurement circuit.   
     
     
         14 . The heating element of  claim 1 , wherein the material of the outer tube is a high-temperature-resistant alloy or metal material. 
     
     
         15 . The heating element of  claim 1 , wherein the outer tube is filled with a high-temperature-resistant insulating medium and is coated with a ceramic coating. 
     
     
         16 . The heating element of  claim 1 , further comprising:
 a base,   wherein a lower end of the outer tube is inserted on the base.   
     
     
         17 . The heating element of  claim 16 , wherein the base comprises a ceramic material. 
     
     
         18 . The heating element of  claim 16 , wherein the lower end of the outer tube is welded to the base through a ceramic paint. 
     
     
         19 . An aerosol-forming device, comprising:
 the heating element of  claim 1 .