1. A method for locating an optimum peeling axis of a log and a maximum radius point on a peripheral surface of the log with respect to said optimum peeling axis on the basis of information of a peripheral profile of the log which is rotated about a preliminary axis thereof for at least one complete turn, comprising the steps of:
computing an optimum peeling axis of the log on the basis of radial distances of the log from said preliminary axis to the peripheral surface of the log at a plurality of predetermined locations spaced along said preliminary axis of the log at each of a plurality of predetermined angularly spaced positions of the log;
providing a plurality of swingable members which are pivotally mounted on a shaft having a longitudinal axis extending in parallel with said preliminary axis of the log and having flat contact surfaces each having a width extending along said longitudinal axis, each of said contact surfaces being swingable with the swingable member relative to a reference position which is defined by an imaginary plane extending through said preliminary axis and said longitudinal axis while in contact with the peripheral surface of the log thereby to follow the peripheral profile of the log being rotated about said preliminary axis;
measuring an angular position of the contact surface of each swingable member with respect to said reference position at each of said predetermined angularly spaced positions of the log by said swingable member;
computing radial distances of the log from a plurality of predetermined locations on said computed optimum peeling axis to selected contact surfaces along imaginary lines extending perpendicularly to said preliminary axis on the basis of the measured angular positions of the contact surfaces; and
comparing said computed radial distances and recognizing the distance having the greatest value as the maximum radius point of the log.
2. The method according to claim 1, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a side of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log.
3. The method according to claim 2, further comprising comparing angles of any two adjacent contact surfaces with respect to said reference position on the basis of the angular positions of such two adjacent contact surfaces measured at each of said predetermined angularly spaced positions of the log, wherein said selected contact surfaces include one of said two adjacent contact surfaces whose angle with respect to said reference position is greater than that of the other of said two adjacent contact surfaces.
4. The method according to claim 1, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a substantial center of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log, and wherein said selected contact surfaces include all contact surfaces.
5. A method for locating an optimum peeling axis of a log and a maximum radius point on a peripheral surface of the log with respect to said optimum peeling axis on the basis of information of a peripheral profile of the log which is rotated about a preliminary axis thereof for at least one complete turn, comprising the steps of:
computing an optimum peeling axis of the log on the basis of radial distances of the log from said preliminary axis to the peripheral surface of the log at a plurality of predetermined locations spaced along said preliminary axis of the log at each of a plurality of predetermined angularly spaced positions of the log;
providing a plurality of swingable members which are pivotally mounted on a shaft having a longitudinal axis extending in parallel with said preliminary axis of the log and having flat contact surfaces each having a width extending along said longitudinal axis, each of said contact surfaces being swingable with the swingable member relative to a reference position which is defined by an imaginary plane extending through said preliminary axis and said longitudinal axis while in contact with the peripheral surface of the log thereby to follow the peripheral profile of the log being rotated about said preliminary axis;
measuring an angular position of the contact surface of each swingable member with respect to said reference position at each of said predetermined angularly spaced positions of the log by said swingable member;
computing radial distances of the log from a plurality of predetermined locations on said computed optimum peeling axis to selected contact surfaces along imaginary lines extending perpendicularly to said computed optimum peeling axis on the basis of the measured angular positions of the contact surfaces; and
comparing said computed radial distances and recognizing the distance having the greatest value as the maximum radius point of the log.
6. The method according to claim 5, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a side of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log.
7. The method according to claim 6, further comprising comparing angles of any two adjacent contact surfaces with respect to said reference position on the basis of the angular positions of such two adjacent contact surfaces measured at each of said predetermined angularly spaced positions of the log, wherein said selected contact surfaces include one of said two adjacent contact surfaces whose angle with respect to said reference position is greater than that of the other of said two adjacent contact surfaces.
8. The method according to claim 5, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a substantial center of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log.
9. An apparatus for locating an optimum peeling axis of a log and a maximum radius point on a peripheral surface of the log with respect to said optimum peeling axis, comprising:
a pair of spindles for holding therebetween a log at a preliminary axis thereof;
a drive for driving at least one of said paired spindles thereby to rotate the log about said preliminary axis for at least one complete turn;
a first sensor for detecting a plurality of angularly spaced positions of at least one of said spindles and of the log;
a plurality of swingable members which are swingably mounted on a shaft having a longitudinal axis extending in parallel with said preliminary axis of the log and having flat contact surfaces each having a width extending along said longitudinal axis, each of said contact surfaces being swingable with the swingable member relative to a reference position which is defined by an imaginary plane extending through said preliminary axis and said longitudinal axis while in contact with the peripheral surface of the log thereby to follow the peripheral profile of the log being rotated about said preliminary axis;
a plurality of second sensors arranged at a spaced interval along said preliminary axis of the log for measuring distances from the respective second sensors to the peripheral surface of the log at each of said angularly spaced positions of the log;
a plurality of third sensors operable in conjunction with said swingable members to measure angular positions of the contact surfaces with respect to said reference position at each of said angularly spaced positions of the log; and
control means operable to compute the optimum peeling axis of the log on the basis of said distances measured by said second sensors, said control means being further operable to compute radial distances of the log from a plurality of predetermined locations on said computed optimum peeling axis to selected contact surfaces along imaginary lines extending perpendicularly to said preliminary axis of the log on the basis of the measured angular positions of the contact surfaces, and to compare said computed radial distances and then to recognize the distance having the greatest value as the maximum radius point of the log.
10. The apparatus according to claim 9, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a side of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log.
11. The apparatus according to claim 10, wherein said control means is operable to compare angles of any two adjacent contact surfaces with respect to said reference position on the basis of the angular positions of such two adjacent contact surfaces measured at each of said predetermined angularly spaced positions of the log, wherein said selected contact surfaces include one of said two adjacent contact surfaces whose angle with respect to said reference position is greater than that of the other of said two adjacent contact surfaces.
12. The apparatus according to claim 9, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a substantial center of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log, and wherein said selected contact surfaces include all contact surfaces.
13. The apparatus according to claim 9, said third sensor includes a rotary encoder.
14. An apparatus for locating an optimum peeling axis of a log and a maximum radius point on a peripheral surface of the log with respect to said optimum peeling axis, comprising:
a pair of spindles for holding therebetween a log at a preliminary axis thereof;
a drive for driving at least one of said paired spindles thereby to rotate the log about said preliminary axis for at least one complete turn;
a first sensor for detecting a plurality of angularly spaced positions of at least one of said spindles and of the log;
a plurality of swingable members which are swingably mounted on a shaft having a longitudinal axis extending in parallel with said preliminary axis of the log and having flat contact surfaces each having a width extending along said longitudinal axis, each of said contact surfaces being swingable with the swingable member relative to a reference position which is defined by an imaginary plane extending through said preliminary axis and said longitudinal axis while in contact with the peripheral surface of the log thereby to follow the peripheral profile of the log being rotated about said preliminary axis;
a plurality of second sensors arranged at a spaced interval along said preliminary axis of the log for measuring distances from the respective second sensors to the peripheral surface of the log at each of said angularly spaced positions of the log;
a plurality of third sensors operable in conjunction with said swingable members to measure angular positions of the contact surfaces with respect to said reference position at each of said angularly spaced positions of the log; and
control means wvvicil is operable to compute the optimum peeling axis of the log on the basis of said distances measured by said second sensors, said control means being further operable to compute radial distances of the log from a plurality of predetermined locations on said computed optimum peeling axis to selected contact surfaces along imaginary lines extending perpendicularly to said computed optimum peeling axis on the basis of the measured angular positions of the contact surfaces, and to compare said computed radial distances and then to recognize the distance having the greatest value as the maximum radius point of the log.
15. The apparatus according to claim 14, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a side of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log.
16. The apparatus according to claim 15, wherein said control means is operable to compare angles of any two adjacent contact surfaces with respect to said reference position on the basis of the angular positions of such two adjacent contact surfaces measured at each of said predetermined angularly spaced positions of the log, wherein said selected contact surfaces include one of said two adjacent contact surfaces whose angle with respect to said reference position is greater than that of the other of said two adjacent contact surfaces.
17. The apparatus according to claim 14, wherein said predetermined locations on the computed optimum peeling axis are points of intersection between said optimum peeling axis and respective imaginary planes extending across the log at a substantial center of the width of the contact surfaces in perpendicular relation to said preliminary axis of the log, and wherein said selected contact surfaces include all contact surfaces.
18. The apparatus according to claim 14, wherein said third sensor includes a rotary encoder.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A fuel cell formed by stacking a membrane electrode assembly and separators in a horizontal direction, the membrane electrode assembly including a pair of electrodes and an electrolyte membrane interposed between the pair of electrodes, the electrodes each having an electrode surface standing vertically in a direction of gravity, a reactant gas flow field being provided for allowing an oxygen-containing gas or a fuel gas as a reactant gas to flow along the electrode surface in the horizontal direction,
wherein the reactant gas flow field includes:
a plurality of corrugated flow grooves extending in a wavy pattern in a horizontal direction, and arranged in the direction of the gravity; and
a flat flow field provided within a power generation area, at a lowermost position in the direction of the gravity, the flat flow field having a bottom extending straight in the horizontal direction.
2. The fuel cell according to claim 1, wherein the bottom of the flat flow field extends straight in the horizontal direction; and
the flat flow field has a ceiling oppositely to the bottom, and the ceiling of the flat flow field extends in a wavy pattern in the horizontal direction.
3. The fuel cell according to claim 2, wherein a flow field cross sectional area of the flat flow field is larger than a flow field cross sectional area of the corrugated flow groove.
4. The fuel cell according to claim 1, wherein the separator is a metal separator, and the metal separator has the corrugated flow grooves formed by press forming;
a resin frame member is provided integrally with the membrane electrode assembly around the electrodes; and
the flat flow field is formed between a straight ridge formed integrally with the resin frame member and the corrugated flow groove.
5. The fuel cell according to claim 1, wherein the bottom of the flat flow field extends straight in the horizontal direction; and
the flat flow field has a ceiling oppositely to the bottom, and the ceiling of the flat flow field extends straight in the horizontal direction.
6. The fuel cell according to claim 5, wherein a flow field width of the flat flow field is constant in the horizontal direction; and
a flow field width of the corrugated flow groove at a lowermost position adjacent to the flat flow field is constant in the horizontal direction.
7. The fuel cell according to claim 1, comprising a first separator, a first membrane electrode assembly, a second separator, a second membrane electrode assembly, and a third separator stacked together,
wherein the second separator has the flat flow field on a first surface facing the first membrane electrode assembly, the bottom of the flat flow field extends straight in the horizontal direction, the flat flow field has a ceiling oppositely to the bottom, the ceiling of the flat flow field extends in a wavy pattern in the horizontal direction, and a flow field width of the corrugated flow groove at a lowermost position adjacent to the flat flow field is constant in the horizontal direction; and,
the second separator has the flat flow field on a second surface facing the second membrane electrode assembly, the bottom of the flat flow field extends straight in the horizontal direction, the flat flow field has a ceiling oppositely to the bottom, and the ceiling of the flat flow field extends straight in the horizontal direction, and a flow field width of the corrugated flow groove at a lowermost position adjacent to the flat flow field is constant in the horizontal direction.