192 clutches and power-stop control – Transmission control and clutch control – Common control
Patent
1997-12-08
1999-11-30
Marmor, Charles A
192 clutches and power-stop control
Transmission control and clutch control
Common control
192 363, B60K 4122
Patent
active
059925906
DESCRIPTION:
BRIEF SUMMARY
This invention relates to fluid-pressure operated actuation systems and in particular, though not exclusively, to such actuating systems used to operate vehicle clutches or vehicle gear selection actuators in manual, semi-automatic and automatic transmissions.
In such actuation systems the clutch or gear selection actuators are controlled by an electronic unit in response to vehicle operating parameters and vehicle driver inputs such as the operation of the vehicle throttle and gear selector lever.
There is a requirement to provide a simple, efficient and cost effective actuation system for the operation of a vehicle clutch or gear selection actuator of the form described above.
It is an object of the present invention to provide the approved form of actuation system which is particularly suitable for the above applications.
Thus according to the present invention there is provided an actuation system comprising a pump which charges an accumulator via a non-return valve, a solenoid-operated control valve which receives pressurised fluid from the accumulator, and a slave cylinder which receives pressurised fluid from the accumulator via the control valve and from which fluid can also be exhausted via the control valve, the control valve has a rest position in which pressurised fluid from the pump is returned to sump (and the slave cylinder is vented to sump), a first energised position in which the return of pressurised fluid to sump is cut-off (and the slave cylinder remains vented to sump), and a further energised position in which venting of the slave cylinder is cut-off and the slave cylinder is supplied with pressurised fluid from the accumulator.
Preferably the pump is electrically driven and is stopped when the accumulator pressure is above a pre-determined level.
Such a system has several advantages: side of the non-return valve is vented to sump thus reducing any tendency for that part of the circuit to leak under high pressure. sump, thus it will not have to try to start against high back pressure in the system. This is particularly significant in lots temperature environments where fluid viscosity is high and pumping losses can therefore be high also. This enables a smaller power output electric motor to be used to drive the pump.
The present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 shows diagrammatically clutch actuation system in accordance with the present invention;
FIG. 2 shows diagrammatically details of a gear ratio selector system in accordance with the present invention;
FIG. 3 shows the gear ratio selector gate used in the system of FIG. 2, and
FIG. 4 shows diagrammatically details of a system in accordance with the present invention which actuates both a vehicle clutch and gear ratio selectors.
Referring to FIG. 1 this shows a clutch actuation system which includes a hydraulic power pack 10 which operates a clutch operating slave cylinder 11 via solenoid operated fluid flow control valve 12. The power pack 10 includes a reservoir 10a, an electrically driven pump 10b, an accumulator 10c and a non-return valve 10d. The slave cylinder 11 acts on a clutch actuating lever 13 which in turn acts on a clutch release bearing 14.
The displacement of clutch operating lever 13 is measured by a sensor 15, whose output is fed to an electronic control unit 65. Control unit 65 receives other vehicle operating parameter inputs designated 16 in FIG. 1 and issues commands to solenoid 12a of the valve 12 to connect slave cylinder 11 to accumulator 10c or reservoir 10a. Full constructional and operational details of a suitable electronic control unit 65 etc. can be found in European patents Nos. 0038113, 0043660, 0059035 and 0101220 and will not therefore be given here.
Returning now to the details of solenoid valve 12, this has an outer portion 30 which is inserted into a bore 31 in a housing 32 and is held stationary therein. The outer portion 30 includes lands 33,34,35 and 36 which are in sealing contact with bore 31 to define
REFERENCES:
patent: 3818776 (1974-06-01), Prenzel et al.
patent: 3834499 (1974-09-01), Candellero et al.
patent: 3946760 (1976-03-01), Murakami et al.
patent: 3979153 (1976-09-01), Ingram et al.
patent: 4194608 (1980-03-01), Usui et al.
patent: 4589532 (1986-05-01), Ito et al.
patent: 5795263 (1998-08-01), Harries
patent: 5836207 (1998-11-01), Spooner et al.
Ho Ha
Kongsberg Techmatic Limited
Marmor Charles A
LandOfFree
Hydraulic actuation system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic actuation system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic actuation system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1661125