Robert Boschgmbh

Helmut Espenschied

Uwe Kiencke

Alfred Schulz

Konrad Eckert

Alexander Witte

Georg Rothfuss

The main pressure in the gearing which under normal operating conditions is 150% of the amount required to transmit the then-present torque is reduced to 100% when an upshift takes place under load or a downshift takes place under no load. For a downshift under load and an upshift under no load the pressure is reduced to about 30%. The position of the control rod of an injection pump at the beginning of a shift operation is stored until the shift is completed. This allows the present system to cooperate with a system wherein the control of the injection pump is shifted from the gas pedal to a regulator during gear shifts.

Method and apparatus for adjusting the operating force applied to gears

To improve vehicle operator comfort and safety and to reduce wear and tear on the automatic transmission, the apparatus prevents an upshift whenever the accelerator pedal is released very quickly. The apparatus stores the load signal which prevailed when the load was abruptly reduced, thereby simulating to the transmission controller a continuation of high load and preventing an undesired upshift, for example in downhill operation and during roll-outs. Normal load signals are restored whenever the accelerator pedal is returned to a predetermined point. In one embodiment, the stored load signal is a hydraulic pressure and in another embodiment, for use with an electronic transmission controller, the load signal is an electrical signal. In a third embodiment, the upshift control signal from the controller to the transmission is interrupted when the apparatus indicates a complete release of the accelerator pedal.

Apparatus for controlling gear shifts in automatic transmissions

A first and second valve respectively associated with the then-present and the newly selected gear during a gear shift operation are operated with positive overlap at the beginning of the shift process if the engine is upshifting under load or downshifting under no and at the end of the shift process if the engine is upshifting under no load or downshifting under load. During the shift process the engine speed is lowered during upshift operations and increased during downshifts. The shifting process is terminated when the engine is operating synchronously with the transmission output. It is also terminated if the engine speed decreases excessive during upshifts or increases excessively during downshift or if a predetermined maximum allowable time has elapsed from the start of the shift operation. The main pressure in the gearing is decreased during the shift operation by a factor selected in accordance with the then-present operating condition.

Automatic transmission with electronically controlled torque

A control unit senses when a gear change command signal is generated and thereupon interrupts the supply of fuel to the engine for a predetermined time, for example about 100 milliseconds. Upon down-shifting, the interruption of fuel supply is delayed to permit the engine to accelerate, thereby simulating double clutching the engine. Fuel supply is interrupted by interrupting injection pulses to an electronic fuel injection system or, if the engine is carburetor-equipped, by supplying air to a bypass connected to the carburetor.

Automatic transmission gear change shock reduction system particularly

The limit switch includes a diode which is connected through a spring-operated switch in circuit with a d-c motor such that, when the motor is commanded to operate in one direction and its limit is reached, the diode is placed in blocking direction in the circuit but, upon reversal of polarity of supply to the motor to reverse its direction, the diode becomes conductive so that a closed circuit is immediately established therefor, the conductive direction of the diode being maintained until a reverse limit is reached, at which time the then conductive diode will be connected in blocked direction. During operation in the normal operating zone of the motor, the diode is short-circuited. The switches themselves can readily be constructed to be cam-operated, for example from a rotating shaft which, selectively, connects the diode in a double-pole, double-throw, center-ON circuit arrangement.

Limit switch for D-C positioning motor

During gear shift, the fuel control for the engine is switched from the gas pedal to a regulator which regulates it such that the speed of the engine is changed from the speed corresponding to the then-present gear to the speed for the next subsequent gear at a predetermined rate of change of speed with respect to time. A different rate of change of speed may be provided for upshift and downshift operations. A comparator compares the engine speed to the output speed of the gearing and furnishes a shift terminate signal signifying synchronism between the two speeds when the two speeds have a predetermined relationship. A first and second offset signal may be applied to the comparator to allow the engine speed to be somewhat less than the output speed of the gear, and vice a versa, during downshift and upshift respectively.

Apparatus for synchronizing the driving and driven members during gear

The cathode of the gas-discharge devices performing the distributor function for associated sparkplugs have lateral extension flanges approaching closely to the insulating envelopes of the devices. A grounded control electrode just outside the gas-discharge device is moved from a rest position to an operating position aligned with and adjacent to the cathode extension flange by an electromagnet operated by a transistor circuit in accordance with the cylinder firing order of the engine.

Engine ignition system with electromagnet control of enclosed

An automotive vehicle has an automatic transmission to which fluid is supplied from a source through a control valve having a body which is displaceable to control the flow of the fluid to the load constituted by this tranmission. A plurality of binarily stepped pilot faces are provided on one side of the valve body and the other side is connectable to the source of fluid pressure. A plurality of pressurizable chambers at each of the surfaces are each connected via a respective line to a respective solenoid valve itself connected to the high-pressure side of this system. Binary actuation of these pilot surfaces via the solenoid valves in accordance with motor speed allows the transmission very smoothly to be upshifted and downshifted.

Hydraulic system for an automatic transmission of an automotive vehicle

Hydraulic gear shift controllers to effect change of transmission gearing are controlled by means of a spool valve having a slider spool located in the bore of a housing, preferably axially aligned with a pressure limiting spool valve. A kick-down hydraulic control line is rapidly activated by an electrical controller which admits pressurized fluid to an end face of the spool, communication of the kickdown pressure control line with the main pressure controller being effected through a blind bore of the main slider spool, and cross bores formed therein to provide rapid control in dependence on electrical signals representative of an engine operating parameter, such as engine speed, or throttle position, and to apply a bias pressure on the slider spool.

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Ludwigsburg, Germany

Helmut Espenschied