Wiper strip, wiper blade and designing method of wiper strip
AssigneeAsmo Co., Ltd.
InventorsIsao Ohta, Masaaki Kiyama
Life of this patent
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Abstract
A relationship between a thickness of a water film at a location of a maximum pressing pressure and a maximum pressure gradient value is deduced. Each corresponding design factor of a wiper blade is determined based on this relationship, and the wiper blade is manufactured. In this way, at the wiper blade, a thickness of the water film right after wiping falls in an appropriate range.
Claims12
A wiper strip comprising a contacting portion, which is engageable with a wiping surface through a liquid film, wherein a maximum pressure gradient value of a pressing pressure profile at the contacting portion against the wiping surface is set to fall in a first range, which is equal to or larger than 44.1 MPa/mm.
A wiper strip comprising a contacting portion, which is engageable with a wiping surface through a liquid film, wherein a maximum pressure gradient value of a pressing pressure profile at the contacting portion against the wiping surface is set to fall in a second range, which is equal to or larger than 88.5 MPa/mm.
A wiper strip comprising a contacting portion, which is engageable with a wiping surface through a liquid film, wherein a maximum pressure gradient value of a pressing pressure profile at the contacting portion against the wiping surface is set to fall in a third range, which is equal to or larger than 509.7 MPa/mm.
A designing method of a wiper strip, comprising determining each corresponding design factor of the wiper strip, which includes a contacting portion that is engageable with a wiping surface through a liquid film, based on a relationship between a maximum pressure gradient value of a pressing pressure profile at the contacting portion against the wiping surface and a thickness of the liquid film at a location of a maximum pressing pressure, wherein the relationship is expressed by the following equation:
- (
-
- P
-
- x
- )
- max
- =
- 8
- 9
- ·
- η
- ·
- U
- h
- m
- 2
- where (dx/dP)max denotes the maximum pressure gradient value;
- “hm” denotes the thickness of the liquid film at the location of the maximum pressing pressure of the contacting portion;
- “η” denotes a coefficient of viscosity of the liquid;
- and
- “U” denotes a moving speed of the wiper strip.
Dependencies are inferred from the claim text.