Title:
グロープラグ
Document Type and Number:
Japanese Patent JP6731331
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To improve heat transfer efficiency from a heating coil to a sheath tube while suppressing short circuit between the sheath tube and the heating coil.SOLUTION: A glow plug is provided with a sheath heater where a heating coil is arranged in a sheath tube. On an inside surface of the sheath tube, recessed/projected parts are formed. In a cross section cutting the sheath heater in parallel to an axial line in the way that the axis line of the sheath heater is included, the following is satisfied: the recessed/projected part is configured by a plurality of recesses arranged on at least one of inner surfaces of an outer wall of a pair of sheath tubes and projections formed between adjacent recesses. Surfaces of the respective recesses form a curve without inflection points. A most projecting part farthest from the outer surface of the outer wall of the sheath tubes at the respective projections is positioned between cross sections of two adjacent wires that are present closest to the most projecting part among wires configuring the heating coil.SELECTED DRAWING: Figure 4
Inventors:
Tomoki Ishiguro
Application Number:
JP2016224881A
Publication Date:
July 29, 2020
Filing Date:
November 18, 2016
Export Citation:
Assignee:
Nippon Special Ceramics Co., Ltd.
International Classes:
F23Q7/00
Domestic Patent References:
| JP5623863U | ||||
| JP57055878U | ||||
| JP2001208347A | ||||
| JP2010249354A | ||||
| JP2014152961A | ||||
| JP2016020774A |
Foreign References:
| US20070023412 |
Attorney, Agent or Firm:
Meisei International Patent Office