Motor vehicles – Having four wheels driven – With manually operated means for disengaging drive to one or...
Reexamination Certificate
2002-12-17
2004-07-06
Lerner, Avraham (Department: 3611)
Motor vehicles
Having four wheels driven
With manually operated means for disengaging drive to one or...
Reexamination Certificate
active
06758297
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present nonprovisional application claims priority under 35 USC 119 to Japanese Patent Application No. 2001-394335 filed on Dec. 26, 2001 the entire contents thereof is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a two-wheel-drive/four-wheel-drive switching system for a vehicle.
2. Description of Background Art
Heretofore, a vehicle is known which can switch between two wheel drive and four wheel drive.
FIGS. 4 and 5
show an example of a vehicle for switching between two wheel drive and four wheel drive. The vehicle
1
is mainly composed of a body frame
3
in the center of which an engine
2
is mounted. Front wheels
4
and rear wheels
5
are arranged on both sides of the front and the rear of the body frame
3
with a steering handlebar
6
arranged on the upside of the front of the body frame
3
for steering the front wheels
4
. A fuel tank
7
is attached to the body frame
3
and a seat
8
attached in the rear of the fuel tank
7
.
A final reduction gear unit for the front wheel
13
and a final reduction gear unit for the rear wheel
14
, respectively, are coupled to the engine
2
via propeller shafts
11
and
12
and are provided in the center of the front and the center of the rear of the body frame
3
.
Drive shafts
9
are coupled to the right and the left of the final reduction gear unit
13
for the front wheels
4
. The front wheels
4
are attached to the drive shafts
9
via wheel hubs
10
attached to the ends of the drive shafts.
Axle housings
22
into which drive shafts for the rear wheel
5
are inserted are provided to the right and the left of the final reduction gear unit for the rear wheel
14
and the rear wheels
5
are attached via wheel hubs
23
arranged at the ends of the axle housings
22
and coupled to the drive shafts.
A two-wheel-drive/four-wheel-drive switching system for switching a state of rear wheel drive and a state of four wheel drive by connecting or disconnecting power transmitted to the front wheels
4
is provided between the final reduction gear unit for the front wheel
13
and the propeller shaft
11
, for example.
In the alternative, the two-wheel-drive/four-wheel-drive switching system may be also provided between the propeller shaft
12
in the rear and the final reduction gear unit for the rear wheel
14
to switch a sate of front wheel drive and a state of four wheel drive.
The states of drive are switched according to a state of a road and an operating state.
The two-wheel-drive/four-wheel-drive switching system is proposed in Japanese published unexamined patent applications No. Hei 11-1131 and No. Hei 10-297313, for example, and
FIG. 7
shows the structure.
The two-wheel-drive/four-wheel-drive switching system
15
shown in
FIG. 7
is shown by axially dividing an input shaft
16
of a final reduction gear unit for a front wheel
13
into two and is composed of two input shaft components
16
a
and
16
b
matched on the same axis and a switching unit
17
for connecting or disconnecting the shafts.
In more detail, a cylindrical positioning protrusion
18
protrudes from the center of the end face of the input shaft component
16
a
positioned on the side of the final reduction gear unit
13
for the front wheels
4
. A positioning concave portion
19
is provided into which the positioning protrusion
18
is fitted so that the positioning protrusion can revolve. The positioning concave portion
19
is formed in the center of the end face of the input shaft component
16
b
and positioned outside. Both input shaft components
16
a
and
16
b
are positioned on the same axis by matching both input shaft components
16
a
and
16
b
so that the positioning protrusion
18
and the positioning concave portion
19
are fitted and are coupled so that they can revolve relatively easily.
Splines S
1
and S
2
are formed on the surfaces of the respective matched parts of both input shaft components
16
a
and
16
b
and the switching unit
17
is provided so that the switching unit surrounds the matched parts.
The switching unit
17
is composed of a slidable switching ring
20
on the inside face of which a spline is formed, which is fitted to the matched parts of both input shaft components
16
a
and
16
b
and the spline of which is engaged or disengaged with/from the respective splines S
1
and S
2
. A driving mechanism
21
is provided for selectively moving the switching ring
20
in a position in which the switching ring
20
is slid in the axial direction of both input shaft components
16
a
and
16
b
and is engaged with only one input shaft component
16
a
or in a position in which the switching ring
20
is simultaneously engaged with the splines S
1
and S
2
of both input shaft components
16
a
and
16
b.
The two-wheel-drive/four-wheel-drive switching system
15
configured as described above turns into a state of two wheel drive in which only the rear wheels are driven by moving the switching ring
20
in one direction by the driving mechanism
21
, engaging the switching ring with only one input shaft component
16
a
and disabling the transmission of driving force to the front wheels
4
and turns into a state of four wheel drive in which the switching ring
20
is engaged with the other input shaft component
16
b
by sliding the switching ring
20
in a state wherein the switching ring is engaged with one input shaft component
16
a
. Thus, driving force is transmitted to the front wheel
4
by coupling both input shaft components
16
a
and
16
b
and the front wheels
4
and the rear wheels
5
are simultaneously driven.
That is, as shown in
FIG. 8
, in a two wheel drive condition, the supply of driving current to the two-wheel-drive/four-wheel-drive switching system
15
is stopped and in a four wheel drive condition, driving current is continuously supplied.
In a four wheel drive condition, an indicator is illuminated so as to inform an operator that the current state of drive is four wheel drive. However, for a method of detecting a state of four wheel drive, a method may be provided of providing a detection switch that is turned on when the detection switch touches the switching ring
20
and a fork that moves the switching ring
20
while the switching ring
20
is moved to a position of four wheel drive and detecting that the detection switch is turned on.
Such a conventional type two-wheel-drive/four-wheel-drive switching system
15
has the following problem that needs to be improved.
That is, in case when the detection switch operated by the switching ring
20
and the fork is used to illuminate the indicator for showing a state of four wheel drive operation, an impact is applied to the detection switch and a noise may be produced every time a state of drive is switched.
The abrasion of the switch due to the impact has an effect upon the precision of the lighting of the indicator.
SUMMARY AND OBJECTS OF THE INVENTION
The invention is made in view of the problems of such a conventional type switch and the object of the present invention is to provide a two-wheel-drive/four-wheel drive switching system for a vehicle wherein noise is hardly made and a state of drive can be securely indicated.
A two-wheel-drive/four-wheel-drive switching system for a vehicle according to the present invention is provided with a switching unit provided to either of the power transmission mechanisms for connecting an engine and a front wheel via a final reduction gear unit and connecting the engine and a rear wheel via a final reduction gear unit for enabling or disabling the transmission of power in the power transmission mechanism. A control unit is provided that controls the drive of the switching unit and indication control means are provided that detects that the transmission of power in the power transmission mechanism wherein an indicator is illuminated so as to achieve the object of the invention. The indication control means detects a phase difference between the revolutions of a
Goto Shinji
Handa Akio
Senda Akio
Tomita Hiroaki
Birch & Stewart Kolasch & Birch, LLP
Honda Giken Kogyo Kabushiki Kaisha
Lerner Avraham
LandOfFree
Two-wheel-drive/four-wheel-drive switching system for vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Two-wheel-drive/four-wheel-drive switching system for vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-wheel-drive/four-wheel-drive switching system for vehicle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3256857