Friction damper and pedal device for vehicle having the friction damper

A friction damper comprising:

• an inner member extending like a shaft;
• a tubular outer member disposed coaxially with said inner member and on an outer side of said inner member;
• a frictionally engaging means provided in an annular space on a radially outward side of said inner member and on a radially inward side of said outer member;
• a resilient means provided in the annular space;
• an urging-force varying means provided in the annular space,
• wherein said frictionally engaging means has a first portion which rotates integrally with said inner member and a second portion which rotates integrally with said outer member and is provided in such a manner as to be capable of coming into contact with said first portion in the axial direction,
• wherein said resilient means is arranged to urge said first portion and said second portion in a direction in which said first portion and said second portion are brought into contact with each other and are pressed against each other, and
• wherein said urging-force varying means is arranged to make variable an urging force of said resilient means in correspondence with a relative rotational displacement of said inner member and said outer member.

A pedal device for a vehicle, comprising:

• a pedal arm which is rotatably supported by a supporting frame;
• a first spring means for rotatively urging said pedal arm to an initial position of its rotation;
• and
• a damper for imparting a resisting force to the rotation of said pedal arm,
• wherein said damper includes:
• a hollow cylindrical member with a bottom;
• a movable member disposed in said hollow cylindrical member in such a manner as to be movable in an axial direction of said hollow cylindrical member but immovable about an axis of said hollow cylindrical member;
• a second spring means disposed between said movable member and the bottom of said hollow cylindrical member, one end of said spring means abutting against the bottom of said hollow cylindrical member and another end thereof abutting against said movable member;
• a rotating member disposed in said hollow cylindrical member in such a manner as to oppose said movable member and to be relatively rotatable about the axis of said hollow cylindrical member;
• and
• a frictionally-resisting-force generating means for generating a frictionally resisting force as the resisting force to the relative rotation of said rotating member with respect to said hollow cylindrical member, and for causing said movable member to move away from said rotating member in the axial direction against the resiliency of said second spring means and to approach the bottom of said hollow cylindrical member so as to increase the spring force of said second spring means, thereby increasing the frictionally resisting force, and
• wherein the rotation of said pedal arm is transmitted as the relative rotation of said hollow cylindrical member and said rotating member.

A pedal device comprising:

• a rotating shaft supported by a supporting frame;
• an accelerator pedal which is disposed at an upper-limit position where said accelerator pedal can be pressed down and which swings about said rotating shaft;
• a resisting means for generating resistance in a direction in which the pressing down of said accelerator pedal is hampered when said accelerator pedal is pressed down;
• and
• an urging means for urging said accelerator pedal in a direction in which said accelerator pedal returns to the upper-limit position when said accelerator pedal is pressed down at the upper-limit position;
• wherein said resisting means is formed by a friction damper in which a portion which rotates by following the swinging motion of said accelerator pedal comes into contact with a stationary portion so as to generate resistance.