FASTENING PRESSURE CONTROL DEVICE FOR STARTING FRICTION ELEMENT AT TIME OF CONTROLLING IDLE STOP OF VEHICLE
First Claim
1. An engagement pressure control apparatus for a starting frictional element at a time of an idle stop control of a vehicle, comprising:
- an engine;
drive wheels;
a transmission configured to transmit a power of the engine to the drive wheels via the starting frictional element under a gear shift;
a gear shift control section configured to perform a gear shift control for the transmission by means of a hydraulic pressure from an engine driven oil pump driven by the engine, during a driving of the engine; and
an idle stop control section configured to, when a predetermined condition is established, perform an idle stop such that the engine is automatically stopped and make the starting frictional element an engagement start immediate before state according to the engagement pressure produced by a partial draining of a working oil from an electrically-powered oil pump by means of a starting frictional element engagement pressure control section and to, when the predetermined condition becomes un-established, restart the engine in response to a release of the idle stop and make the engine a driving operation responding state, at a time of a vehicle stop determination, wherein, during an operation of the idle stop control section, a drain port opening angle of a clutch hydraulic pressure control valve for an engagement pressure command value issued to the starting frictional element engagement pressure control section is made small as compared with the drain port opening angle of an ordinary control in accordance with an input torque of the starting frictional element.
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Accused Products
Abstract
A required draining capacity of an electrically-powered oil pump is reduced and a small sizing of the electrically-powered oil pump is achieved by devising how to issue a starting frictional element engagement pressure command value.
[Means for Solving the Problem]
An engine is restarted in response to an idle stop OFF command at t1 so that a gear shift control purpose hydraulic pressure is raised according to a working oil from an engine driven oil pump. An idle stop release time control of the engine is allowed according to a torque down unnecessary determination when a gear shift control purpose hydraulic pressure has reached to a set hydraulic pressure at t2. In a case where this allowance causes an engine torque Te to be raised from a torque down value toward a driving operation corresponding value by a predetermined gradient ΔTe1, a command value of a starting frictional element engagement pressure PS is set to a control maximum value (a drain port opening angle of a clutch hydraulic pressure control valve for a clutch hydraulic pressure (an engagement pressure) command value is made small as compared with that in a case of an ordinary control (is made difficult to drain)) during the idle stop control including during the idle stop release time control. Thus, when starting frictional element engagement pressure PS is controlled upon receipt of this command value, the working oil from the electrically-powered oil pump is not needed to be drained. Consequently, the electrically-powered oil pump is not needed to discharge this draining working oil and the small-sizing can be achieved.
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Citations
7 Claims
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1. An engagement pressure control apparatus for a starting frictional element at a time of an idle stop control of a vehicle, comprising:
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an engine; drive wheels; a transmission configured to transmit a power of the engine to the drive wheels via the starting frictional element under a gear shift; a gear shift control section configured to perform a gear shift control for the transmission by means of a hydraulic pressure from an engine driven oil pump driven by the engine, during a driving of the engine; and an idle stop control section configured to, when a predetermined condition is established, perform an idle stop such that the engine is automatically stopped and make the starting frictional element an engagement start immediate before state according to the engagement pressure produced by a partial draining of a working oil from an electrically-powered oil pump by means of a starting frictional element engagement pressure control section and to, when the predetermined condition becomes un-established, restart the engine in response to a release of the idle stop and make the engine a driving operation responding state, at a time of a vehicle stop determination, wherein, during an operation of the idle stop control section, a drain port opening angle of a clutch hydraulic pressure control valve for an engagement pressure command value issued to the starting frictional element engagement pressure control section is made small as compared with the drain port opening angle of an ordinary control in accordance with an input torque of the starting frictional element. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification