Heater unit and steering wheel
The present invention provides a steering wheel and a heater unit used for the steering wheel that does not give discomfort to a user when operating the steering wheel. A heater unit 31 is comprised of a substrate 10 made of a polymeric foam; and a cord-shaped heater 1 arranged on the substrate 10 , wherein a thickness of the substrate 10 is thinner at a portion on which the cord-shaped heater 1 is arranged than other area so that the portion is formed along a shape of the cord-shaped heater 1 and the heater unit 31 is flat. A steering wheel, comprised of the above described heater unit; a wheel core material; and a covering material, wherein the heater unit is arranged between the wheel core material and the covering material.
1. A heater unit, comprising:
a substrate made of a polymeric foam; and
a cord-shaped heater arranged on the substrate, wherein
a thickness of the substrate is thinner at a portion on which the cord-shaped heater is arranged than other area so that the portion is formed along a shape of the cord-shaped heater and the heater unit is approximately flat,
a heat-fusing portion is formed on an outermost layer of the cord-shaped heater, and
the heat-fusing portion of the cord-shaped heater is melted and permeated in the polymeric foam to form a fixed portion.
2. The heater unit according to claim 1 , wherein
the thickness of the substrate is approximately constant at the portion on which the cord-shaped heater is arranged.
3. The heater unit according to claim 1 , wherein
the thickness of the fixed portion exceeds 60% of the thickness of the substrate.
4. The heater unit according to claim 1 , wherein
the thickness of the fixed portion is approximately same as the thickness of the substrate.
5. The heater unit according to claim 1 , wherein
the width of the fixed portion exceeds three times of the width of a core material.
6. The heater unit according to claim 5 , wherein
the width of the fixed portion does not exceed five times of the width of the core material.
7. The heater unit according to claim 1 , wherein
the thickness of the fixed portion exceeds 1.3 times of the width of the core material.
8. The heater unit according to claim 7 , wherein
the thickness of the fixed portion does not exceed 2.5 times of the width of the) core material.
9. The heater unit according to claim 1 , wherein
nothing other than the cord-shaped heater is arranged on the substrate at a surface on which the cord-shaped heater is arranged.
10. The heater unit according to claim 1 , wherein
the substrate is formed by laminating a plurality of formed bodies having different porosity, and
the porosity is higher at the foamed body on which the cord-shaped heater is arranged than the porosity of the other foamed bodies.
11. A steering wheel, comprising:
the heater unit according to claim 1 ;
a wheel core material; and
a covering material, wherein
the heater unit is arranged between the wheel core material and the covering material.
12. A method of manufacturing a heater unit,
the heater unit comprising:
a substrate made of a polymeric foam,
a cord-shaped heater, and
a heat-fusing portion is formed on an outermost layer of the cord-shaped heater,
the method comprising the steps of:
arranging the cord-shaped heater on the substrate in a predetermined pattern shape; and
thermally compressing the substrate by a flat plate, wherein
a thickness of the substrate is thinner at a portion on which the cord-shaped heater is arranged than other area so that the portion is formed along a shape of the cord-shaped heater and the heater unit is approximately flat, and
the heat-fusing portion of the cord-shaped heater is melted and permeated in the polymeric foam to form a fixed portion.