Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This present invention relates to gear shifting
device for semi or fully automatic shifting of multi-stage gear
boxes with mechanical synchronization, more particularly for
automotive vehicles, with an electric/electronic control part,
gear shifting being initiated manually by means of a selector
switch, or being effected and controlled automatically with
control and actuating devices for moving the transmission and
clutch parts to be moved during a gear shift, the parts of the
gear shifting device, provided for both semi-automatic and fully-
automatic operation, being designed either purely electrically
with solenoid valves or electro-hydraulically or electro-
pneumatically with solenoid valves and actuating pistons.
Gear boxes equipped with mechanical synchronization
may also consist of only one basic transmission, but may also be
extended, in order to obtain additional gears, with a multiply-
ing range group and/or a split group. Finally, both the basic
; transmission and the range and split group may be designed
either as a countershaft or planetary gear.
Robert Bosch~s German Auslegeschrift 20 36 732 dated
October 5, 1578, discloses a device for synchronized shifting of
multi-step gear boxes. Power is transferred, through a starting
and disconnect clutch, from the engine to the multi-step gear
box which is of the counter-shaft type. The clutches to be
shifted are centrally synchronized. Semi-automatic shifting,
for example is rendered possible by means of an electrical
control unit and a gear preselector. In this case, the control
is entirely electric, while actuation for gear shifting is
hydraulic. No example of fully automatic operation is given.
Robert Bosch~s German Auslegeschrift 21 36 960 dated
30 July 13, 197~, discloses a device for semi or fully automatic
shifting of multi-stage gear boxes with mechanical synchroniza-
tion associated with the clutches. Gear shifting is e~fected
electro-hydraulically, by means of an electric or elec-tronic
control part, through control valves.
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In the case of semi automatic shifting, push buttons are
provided for presele~ting the gear to be engaged or the trans-
mission stage to be shifted, and for initiating the preselected
gear shift.
During fully automatic operation, the control part
is acted upon by signals indicating the operating condition
of the relevant automotive vehicle, e.g. engine r.p.m.,
accelerator pedal position, the position of the gear shift
sleeves, and ~he clutches provided between the engine and
the transmission.
A factor common to all automatic transmissons is
that driver intervention is impossible, except for the "Xick-
down" and the selection of specific gear ranges which are to
be shifted automatically only.
This presents problems in the case of heavy trucks
and in hilly country, where the automatic transmission may shift
at a time when an experienced and cautious driver would not
shift. In the case of automatic transmissions in countershaft
design, which also have a disconnect clutch for shifting and
in which traction is interrupted, even if only for a short
time, during gear shifting, an unwanted gear shift of this
kind may be particularly dangerous.
In the case of heavy vehicles in particular, adapt-
ation of the vehicle drive to driving conditions is accomplished
very satisfactorily by means of a multi-stage gear box of
countershaft and group design. In spite of a favourable
configuration of the gear shifting device, with shifting made
easy for the driver, for example by means of double H and
split shifting at the shift lever, the driver rarely makes
; 30 use of all of the favourable adaptations that are possible.
Having reference to the last mentioned r~ference,
it i9 therefore an important aim o~ the present invention to
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improve a.gear shifting device for semi or fully automatic
shifting of multi-stage gear boxes with mechanical synchroni-
zation, more particularly for automotive vehicles, with an
electric/electronlc control part, gear sh:i~ting being
initiated manually by means of a selector switch, or being
effected and controlled automatically with control and
actuating devices for moving the transmission and clutch parts
to be moved during a gear shift, in such a manner that the
driver, in spite of optimal adaptation of the vehicle to the
engine by means of a multi-speed transmission, is relieved
as far as possible of the effort needed to shift gears and may,
.if necessary, intervene in the drive train ratio. This provides
not only optimal economic operation, but also a high degree of
safety by perrnitting rapid intervention by the driver.
The aforementioned aim is achieved in that in one
aspect of the present invention there is provided a gear
: shifting device for semi or fully automatic shifting of multi-
stage gear boxes with mechanical synchronization, more par-
ticularly for automotive vehicles, with an electric/electronic
control part, gear shifting being initiated manually by means
of a selector switch, or being effected and controlled
automatically with control and actuating devices for moving
the transmission and clutch parts to be moved during a gear
shift, characterized in that the selector switch comprises
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two selector levers by means of which the range of automatic
,
shifting is determined both upwardly and downwardly, the
selector switch also comprising a locking means acting upon
the selector levers and acting at all times through the gear
actually engaged in automatic transmission, so that when
either selector lëver is actuated, it is held in the gear
engaged: and in that actuation for.servo manual shi~tin~ in
both select.ing directions is possible only with the said
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selector levers guided in parallel.
- As described in detail in document P 32 47 658.2,
the two selector levers have a great influence upon the range
~hich is to be shifted automatically. Furthermore, the
driver is aware, th~ ugh the gear indicator, of which ge~r
is enga~ed by the automatic transmission. As a result of the
lock, corresponding to the gear engaged, in the selector
switch, the two selector levers can be moved rapidly from
both shift range limits to the said lock, so that the automatic
transmission can no longer shift gears. The driver is now in
a position to shift gears manually, in known fashion, by a
servo mechanism, by means of the selector levers guided in
parallel.
The various configurations of the invention discussed
hereinafter offer particular advantages.
The optical gear indicator, for example, disclosed
and described hereinafter, which indicates the gear actually
_ engaged during automatic operation, or the gear proposed by the
automatic transmission during manual servo shifting parallel
selector lev~r position provides decision making assistance
for the driver in both operating conditions. This contributes
greatly to safety, especially in the case of multi-gear trans-
missions. If this gear indicator is supplemented with a shift
indicator or an invitation to shift, this again simplifies
operation during manual servo shifting and contributes to
safety, since the driver need not keep in mind the position
of the selector lever. In certain cases, only one gear in-
dicator (invitation to shift) may be suEficient.
If a pressure switch is arranged near the accelerator
pedal to lock the gear actualiy engaged durin~ automatic oper-
ation, this intervention can still more rapidLy prevent a
proposed change-up, at least until the two se:lectar levers in
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parallel permit manual servo shifting. Under particularly
critical conditions, e.g. very heavy vehicles in dlfficult
country, it is an advantage to have a device which indicates
to the driver the gear provided by the automatic transmission or
even the shift proposed, even though the actual shift is initiated
by the shift pulse itself - actuation of the pressure switch.
Further details of the invention are described
hereinafter in conjunction with the example of embodiment
illustrated in the drawing attached hereto wherein:
Figure 1 is a diagrammatical representation of a gear
shifting device in accordance with the present invention:
Figure 2 shows a selector switch diagrammatically in
connection with the active lock, in accordance with the present
invention.
Shown in Figure 1 is a multi-stage gear box 1 with
; 4 speeds in basic transmission 11, followed by a group trans-
mission 12 with two ranges and a split group 13 arranged at the
input to the gear box, thus providing, in known fashion, 16
shiftable forward speeds~ The speeds of basic transmission 11,
doubled by group transmission 12 to 8 speeds which are again
doubled by split ~roup 13, may be shifted by selector lever 3
known from document P 32 47 658.2, if the two selector levers,
for example are actuated and guided in parallel. In automatic
operation, the range provided for automatic shifting is limited
by selector levers 31,32. If only 8 speeds are provided for
general automatic shifting, and if selector switch 3, and
electronic control part 2, are designed for this number of
speeds an electrical switch 33, for example, is fitted to the
said selector switch for changing to the East or slow split
group. q'his yives two groups each with ~ speeds which are
preselected but may also be shifted in a~toma-tic operation
and in manual servo shifting.
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2 is an electronic part with leads 71 running to a
power source (battery) 7, leads 51 runnin~ to accelerator pedal
5, leads 21 running to gear and shift ind:icator 4, 45 and leads
22 running to selector switch 3. The latter is also'connected
exclusively to electronic control part 2, whereas actuating
devices 14, 15, 16, 17, 81 for basic transmission 11 may be
connected, for example, to the rotating shaft or also to the
gear shift sleeves themselves - group and split transmissions
12, 13 and, for starting and disconnect clutch 8, by both
iO electrical leads and pressure medium lines 35. If the gear
shifting device is of electro pneumatic design, a source of
compressed air and a valve assembly 6 are needed, in which
case individual solenoid valves 63 receive emitter signals
from electronic control part 2.
An electrical pressure switch 9, which releases a
signal, through an electrical lead 91, to electronic control
part 2, only as long as it is actuated, is also arranged near
the accelerator pedal S, for example. This signal can inhibit
or initiate a shift by the automatic transmission.
According to document P 32 47 658.2, in automatic
operation, the range in which automatic gear shifting is to
take place is limited by selector levers 31, 32 on selector
switch 3. A shift indicator 4, which may be arranged separately
but which may also be connqcted to selector switch 3, indicates
.
the gear actually s~hifted'by the automatic system electronic
control part 2. In this case, the electronic system controls,
as a function of r.~.m. and driving conditions for example,
solenoid valves 63 of valve assembly 6, while actuating devices
14,15,16,81 for multi-staqe gear box 1 and also for s-tarting
and disconnect clutch 8, are acted upon by compressed air.
While it is being actuated, pressure switch 8 can suppress
active shifting. ~he gear engaged may also be loc'ked if
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selector levers 31, 32 are moved, from the outside, to the
gear actually engaged and thus stand side by side. In this
case gear indicator 4 may continue to indicate the gear
selected automatically, but may also be locked at the gear
actually engaged. Movement of the gear lever is favoured
since a locking means 34, acting on both sides, is activated
in the position of the engaged gear, so that selector levers
31, 32 cannot be moved therebeyond. With selector levers 31,
32 guided in parallel, it is possible, as is known, to shift
manually, in which case solenoid valves 63 are acted upon by
selector switch 3 through electronic control part 2, the said
solenoid valves adjusting, in known fashion, actuating devices
14,15,16,81 on gear box 1. Gear indicator 4 in this case
indicates the gear selected by the automatic system for shifting.
If a shift indicator ~an invitation to shift) is provided -
alone or additionally - this always lights up when the gear
engaged by the manual servo shift differs from the automatic
shift provided. Pressure switch 9 may be linked to the auto-
matic system (electronic control part 2) in such a manner that
a gear is offered by the said electronic control part, accord-
ing to the programme, and is displayed (gear indicator 4), but
is actually engaged only when a pulse is released by the
driver through the said pressure switch.
The automatic system, and thus the gear division on
selector switch 3, may also be designed only for speeds in
basic transmission 11 in conjunction with group transmission
12, e.g. for 8 speeds. In such a case, the change over from
the fast to the slow split group, or vice versa, is effect~d
by an electrical switch preferably fitted to the selector
switch.
Figure 2 illustrates diagra~natically a section 30
of selector switch 3 with selector levers 31,32~ Wlth gear
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34 engaged, lock 36 stops selector levers 3, 32 when they
are moved. 33 is the selector switch which initiates activation
of slow or fast split group 13.
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