VEHICLE SPEED DETECTION UNIT AND WHEEL ATTACHMENT UNIT

• US 20100307240A1
• Filed: 12/04/2008
• Published: 12/09/2010
• Est. Priority Date: 12/07/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Kiyotaki, Kouichi, Tezuka, Naotoshi
• Granted Patent: US 8,567,245 B2
• Time in Patent Office: Days
• US Class Current: 73/494
• CPC Class Codes: B60G 2204/115 Wheel hub bearing sensors
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: G01P 1/00 Details of instruments
• CPC Class Codes: G01P 1/026 for speed measuring devices, e.g. pulse generator
• CPC Class Codes: G01P 3/443 mounted in bearings bearings F16C

Abstract

It is an object, in a wheel attachment unit holding a rotary encoder externally attached to a wheel, to certainly acquire an encoder output signal obtained from a rotating shaft of a tire, by reducing an occurrence of a bending deformation or breakage of a unit component (e.g., shaft) occurred during a vehicle run and making the encoder function normally. A shaft, through which there is passed a cable for outputting a measurement result of the encoder whose rotating shaft is connected to the wheel, is arranged offset from the axle center by a predetermined amount and is held by a bracket attached to the vehicle, to be movable in the up and down direction. Alternatively, a holder for holding a stator of the encoder is attached to the body of the vehicle, by a rotary linkage mechanism to hold rotatably with five degrees of rotational freedom.

Claims

1. A vehicle speed detection unit comprising:

a vehicle speed detecting part to be installed in a vehicle in order to measure a rotation angle of an axle of the vehicle;

a shaft, being tubular, through which an output cable for outputting a measurement result of the vehicle speed detecting part passes; and

a cover, attached to the vehicle, to cover and protect the shaft,

wherein one end of the shaft is connected to the vehicle speed detecting part, at a position offset in one of a vehicle forward direction and a vehicle backward direction from the axle by a predetermined amount, and other end of the shaft passes through a hole provided in the cover, to be held in an approximately perpendicular direction with respect to a road surface.

2. The vehicle speed detection unit according to claim 1, wherein the one end of the shaft is connected to the vehicle speed detecting part through an elastic body.

3. The vehicle speed detection unit according to claim 1, wherein the one end of the shaft is connected to the vehicle speed detecting part, at the position offset by the predetermined amount being one of less than and equal to a wheel radius of the vehicle.

4. The vehicle speed detection unit according to claim 1, wherein the cover is attached to a tire housing part of the vehicle, is approximately an inverted trapezoid whose width of a bottom part is narrow and width of an upper part is wide, and covers the shaft with a part between the bottom part and the upper part.

5. The vehicle speed detection unit according to claim 4, wherein the cover has the hole in the bottom part.

6. The vehicle speed detection unit according to claim 5, wherein the hole is a circular hole, with a rounded edge, formed in a holding component fixed to the bottom part of the cover.

7. A vehicle speed detection unit comprising:

a rotary encoder having a rotating shaft fixed to an axle of a vehicle;

a shaft for holding the rotary encoder, at a position offset in a horizontal direction from the axle of the vehicle; and

a cover, fixed to the vehicle, for holding the shaft to be slidable in an up-and-down direction.

8. The vehicle speed detection unit according to claim 7, wherein the shaft is arranged between a wheel of the vehicle and the cover.

9. A wheel attachment unit comprising:

a rotary encoder whose rotating shaft is connected to a wheel of a vehicle; and

a rotary linkage mechanism, attached to a body of the vehicle, for rotatably holding the rotary encoder, with five degrees of rotational freedom.

10. The wheel attachment unit according to claim 9, wherein the rotating shaft of the rotary encoder, which rotates with respect to a stator, is connected to the wheel of the vehicle,

the wheel attachment unit further comprises

a holding tool for holding the stator of the rotary encoder, and

a vehicle attachment to be attached and fixed, diagonally upward of an axle of the wheel, to a fender periphery of the body of the vehicle,

wherein the rotary linkage mechanism includes a first link and a second link which are rotatably connected with having a first rotating joint, and includes a second rotating joint and a third rotating joint, holding the first link and the second link therebetween, for respectively connecting ends of the first link and the second link to the holding tool and the vehicle attachment, and

wherein degree of rotational freedom of the first rotating joint, the second rotating joint, and the third rotating joint is totally five degrees of rotational freedom.

11. The wheel attachment unit according to claim 9, further comprising:

an attachment hub for connecting the rotating shaft of the rotary encoder to the wheel of the vehicle;

a holding tool for holding a stator of the rotary encoder; and

a vehicle attachment attachable to the body of the vehicle,

wherein the rotary linkage mechanism includes

a first link, rotatably connected to the holding tool, to rotate about an axis of a second rotating joint which intersects perpendicularly to a longitudinal direction of the first link and the rotating shaft of the rotary encoder and has one degree of rotational freedom, and

a second link, whose one end is rotatably connected to the first link, to rotate about an axis of a first rotating joint intersecting perpendicularly to the longitudinal direction of the first link and an axis of a second rotating joint and having one degree of rotational freedom, and whose other end is rotatably connected to the vehicle attachment, around a third rotating joint having three degrees of rotational freedom,

wherein the third rotating joint is arranged offset in one of a forward direction and a backward direction of the vehicle, with respect to the rotating shaft of the rotary encoder, and the first rotating joint is arranged lower than a line connecting the rotating shaft of the rotary encoder and the third rotating joint.

12. The wheel attachment unit according to claim 9, further comprising:

an attachment hub for connecting the rotating shaft of the rotary encoder to the wheel of the vehicle;

a holding tool attached to a stator of the rotary encoder; and

a vehicle attachment attachable to the body of the vehicle,

wherein the rotary linkage mechanism includes

a first link including a second rotating joint which intersects perpendicularly to the rotating shaft of the rotary encoder and has two degrees of rotational freedom, and being rotatably held to the holding tool, around the second rotating joint, and

a second link whose one end is rotatably connected to the first link, to rotate about an axis of a first rotating joint intersecting perpendicularly to a longitudinal direction of the second link and a longitudinal direction of the first link and having one degree of rotational freedom, and whose other end is rotatably connected to the vehicle attachment, around a third rotating joint having two degrees of rotational freedom,

wherein the third rotating joint is arranged offset in one of a forward direction and a backward direction of the vehicle, with respect to the rotating shaft of the rotary encoder, and the first rotating joint is arranged lower than a line connecting the rotating shaft of the rotary encoder and the third rotating joint.

13. The wheel attachment unit according to claim 10, wherein the vehicle attachment includes

an attaching stationary plate hanging down from a lower part of an over fender of the vehicle, and attached to the fender periphery of the vehicle, diagonally upward of the axle of the wheel,

a cover attached to the attaching stationary plate, to cover the attaching stationary plate and the second link, and

a guide protrudingly provided between the cover and the attaching stationary plate, to have a space against the attaching stationary plate, and contactlessly enclosing a part of the second link, with the attaching stationary plate.

14. The wheel attachment unit according to claim 10, wherein the first link has a space for storing a signal output cable of the rotary encoder.