Heater and glow plug
First Claim
1. A heater comprising:
- a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter;
a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion, a base end side-larger diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the heating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the base end side-larger diameter portion is formed between the fitting portion and the smaller diameter portion, the base end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, and the top end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion.
1 Assignment
0 Petitions
Accused Products
Abstract
A heater comprising: a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter; a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion, a base end side-larger diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the heating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the base end side-larger diameter portion is formed between the fitting portion and the smaller diameter portion, the base end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, and the top end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion.
29 Citations
10 Claims
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1. A heater comprising:
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a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter;
a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion, a base end side-larger diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the heating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the base end side-larger diameter portion is formed between the fitting portion and the smaller diameter portion, the base end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, and the top end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion. - View Dependent Claims (2, 3, 4)
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5. A glow plug comprising:
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a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter;
a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion, a base end side-larger diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the heating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the base end side-larger diameter portion is formed between the fitting portion and the smaller diameter portion, the base end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, and the top end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion. - View Dependent Claims (6, 7, 8)
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9. A heater comprising:
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a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter;
a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the beating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, the top end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, and a diameter difference between an inner diameter of the engagement portion and an outer diameter of an end portion on the base end side in the smaller diameter portion lies in a range from 0.02 to 0.5 mm.
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10. A glow plug comprising:
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a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter;
a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the heating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, the top end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, and a diameter difference between an inner diameter of the engagement portion and an outer diameter of an end portion on the base end side in the smaller diameter portion lies in a range from 0.02 to 0.5 mm.
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Specification