Heater unit

Patent metadata

Field	Value
Publication number	US-11490464-B2
Application number	US-201916598100-A
Country	US
Kind code	B2
Filing date	Oct 10, 2019
Priority date	Apr 12, 2017
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A heather unit including a small diameter sheath heater with improved reliability is provided. The heater unit includes a first substrate having a first joint surface and a second substrate having a second joint surface being joined together, a groove arranged on at least one of the first joint surface or the second joint surface, and a sheath heater arranged inside the groove. The sheath heater includes a metal sheath, a heating wire having a band shape, the heating wire arranged with a space within the metal sheath so as to rotate with respect to an axis direction of the metal sheath, an insulating material arranged in the space, and connection terminals arranged at one end of the metal sheath, the connection terminals electrically connected with both ends of the heating wire respectively.

First claim

What is claimed is:

1. A heater unit comprising:
a first substrate having a first joint surface and a second substrate having a second joint surface being joined together;
a groove arranged on at least one of the first joint surface or the second joint surface; and
a sheath heater arranged inside the groove;
wherein the sheath heater comprises,
a metal sheath,
a heating wire having a band shape, the heating wire being separated from the metal sheath so as to form a helical structure about an axis parallel to an axial direction of the metal sheath, and being arranged in a double helix structure so as to form a biaxial region in the metal sheath,
an insulating material arranged between the heating wire and the metal sheath, and
connection terminals arranged at one end of the metal sheath, the connection terminals electrically connected with both ends of the heating wire respectively, and

wherein surface directions formed by a width of the biaxial heating wire are substantially parallel, and a rotation direction of each helix of the heating wire is substantially the same and a rotation pitch is substantially the same.

2. The heater unit according to claim 1 , wherein a plurality of the sheath heaters is arranged and controlled independently of each other.

3. The heater unit according to claim 1 , wherein the groove is arranged on the first joint surface.

4. The heater unit according to claim 1 , wherein a material used for the metal sheath, the first substrate and the second substrate has the same coefficient of thermal expansion.

5. The heater unit according to claim 1 , wherein a material used for the metal sheath, the first substrate and the second substrate is the same metal material.

6. The heater unit according to claim 1 , wherein a metal material used for the metal sheath, the first substrate and the second substrate is aluminum.

7. The heater unit according to claim 1 , wherein the first substrate and the second substrate are joined together by soldering.

8. The heater unit according to claim 1 , wherein the insulating material is an inorganic insulating powder.

9. The heater unit according to claim 1 , wherein the heating wire is a nickel-chrome alloy and the insulating material is magnesium oxide.

10. The heater unit according to claim 1 , wherein the rotation axes of each helix of the heating wire are arranged in a state where they substantially match so that the biaxial heating wire is coiled having the double helix structure.

Assignees

• Nhk Spring Co Ltd

Inventors

• Hanamachi Toshihiko
• Sekiya Kenji
• Takahara Go
• Aikawa Naoya
• KISARA Yuta
• Tatsumi Arata

Classifications

• H10P72/0432

  mainly by conduction · CPC title

• H05B2203/014

  Heaters using resistive wires or cables not provided for in H05B3/54 · CPC title

• H10P72/7626

  characterised by the construction of the shaft · CPC title

• H05B3/48 Primary

  heating conductor embedded in insulating material · CPC title

• H01C1/03

  with powdered insulation · CPC title