MXPA96006313A - Hydraulic system for interlocking the clutch of the torque converter - Google Patents

Abstract

The present invention relates to a transmission having multiple speed ratios, a system for producing a pressure signal whose magnitude represents the locked and unlocked operation of a converter clutch, comprising: a first pressure source representing the forward driving operation of the transmission, a second source of pressure representing the operation of the transmission at a first forward speed ratio, a regulated pressure source, a third pressure source having a scale of magnitude that varies in response to the speed of the transmission. motor, an outlet orifice, an interlocking valve means for producing coverting interlock pressure having a first quantity representing a command for unlocking the convector, opening a connection between the regulated pressure source and the outlet orifice, and a second magnitude representing a command to lock the converter in response to the effect of the first, second and third sources of

Description

"HYDRAULIC SYSTEM FOR CONNECTING THE CLUTCH OF THE TORQUE CONVERTER" BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to the control system for an automatic transmission, particularly with respect to the control of a bypass clutch of the torque converter. 2. DESCRIPTION OF THE PREVIOUS TECHNIQUE A hydrokinetic torque converter, which forms a hydrokinetic torque flow path from the crankshaft of the motor to the input elements of a gear ring of an automatic transmission, includes a turbine and a propeller placed in a circuit of Toroidal fluid flow. It also includes a friction bypass clutch adapted to connect the impeller to the turbine in order to establish a mechanical torque flow path in parallel with respect to the hydrokinetic torque flow path of the torque converter.

The hydrokinetic torque converter of our invention includes a bypass clutch controlled by a hydraulic valve system. The bypass clutch has features that are common to the control system described in U.S. Patent No. 5,029,087 and the control system of the hydrokinetic torque converter of U.S. Patent Number 5,303,616. These patents have been assigned to the concessionaire of our present invention. Patent Number '087 discloses a torque converter control system having a latching clutch for establishing a controlled mechanical torque flow path between the motor and the transmission gear and for modifying the capacity of the torque clutch. derivation during the displacement intervals. That patent discloses an electronic control strategy to effect a control slip in a bypass clutch of the torque converter whereby the bypass clutch is actuated by the pressure of the clutch solenoid of the modulated converter from a valve of clutch solenoid to effect a variable clutch capacity so that the resulting control slip results in a real slip approaching a reference slip determined by the operating parameters of the driving line. Patent Number '616 discloses a torque converter control system having a latching clutch to establish a controlled mechanical torque flow path between the motor and the transmission gear and to modify the capacity of the clutch of derivation during intervals of speed changes.

COMPENDIUM OF THE INVENTION An object of the interlocking system of the converter of this invention is to prohibit the coupling of the clutch of the converter for an inappropriate period of time, such as when the forward or reverse couplings are initiated, but nevertheless, to allow clutch engagement in all the advance scales and low engine speeds when the transmission is running at second, third, fourth and fifth speed changes. Essentially, an interlocking valve 130 compares the multiple hydraulic pressure control signals and produces a high pressure or low pressure signal output, which output is applied to a regulating valve of the converter.

By obtaining these objects and advantages in a transmission having multiple speed ratios, a system for producing a pressure signal whose magnitude represents the locked and unlocked operation of the converter clutch, includes a first pressure source representing the driving operation of transmission advance, a second source of pressure representing the operation of the transmission in a ratio of forward speed first, a regulated pressure source and a third pressure source that has a scale of magnitude that varies in response to engine speed. An interlock valve produces the interlock pressure of the converter having a first quantity representing a control for unlocking the converter by opening a connection between the source of the regulated pressure and the outlet orifice, and a second quantity representing a command for interlock or hold the converter in response to the effect of the first, second and third pressure sources.

BRIEF DESCRIPTION OF THE DRAWINGS Figures 1A, AB and 1C in combination, show a schematic diagram of a hydraulic control circuit for an automatic transmission. Figure 2 shows the variation of the flow regime through a sharp-edged orifice and a laminar orifice, as changes in temperature. Figure 3 is a schematic diagram of the symbols of ANSI for a modified relief valve to include a sharp-edged orifice and a laminar orifice. Figure 4 is a schematic diagram of the symbols of ANSI to reduce the modified valve to include a sharp-edged hole and a laminar orifice. Figure 5 is a schematic diagram of the microprocessor, sensors and solenoid controlled valves that are used to control the operation of the transmission.

DESCRIPTION OF THE PREFERRED MODALITY With reference to Figures 1A and IB, the hydraulic system for controlling and actuating the components of an automatic transmission for an automotive vehicle includes a drain 10 wherein the hydraulic fluid is contained and from which it is removed by a purification pump 12. and supplied to a reservoir 14. The inlet of a high flow rate pump 16 is connected through a check valve 18 to the reservoir. The output of the pump 16, the secondary regulated pressure SRP is maintained at approximately 8.44 kilograms per square centimeter gauge or greater, through the operation of the SRP control valve 52. The pump inlet 22 is withdrawn partially from the reservoir 14 through a supercharging nozzle 24 which carries the fluid through the system from the various components of the transmission. The output of the pump 22 on the line 24 is maintained at a regulated line pressure through the control of a pressure signal produced by a valve 25 operated by a variable force solenoid, and is applied to a pressure regulating valve 212 Clutch capacity line. The torque converter 20 includes a wheel 26 of the impeller with vanes, permanently connected in a driven manner by a case 28 of the propeller to the crankshaft of an internal combustion engine 30. A turbine wheel 32 with vanes and a wheel 34 of the stator with vanes are mounted in relation to the propeller so as to form a toroidal flow path within which the hydraulic fluid of the torque converter circulates and rotates about the axis of the torsion. Torque converter. The stator wheel 34 is mounted on a unidirectional clutch 36 to provide a unidirectional drive connection to the transmission case. An interlock or bypass clutch 38 of the torque converter, when engaged, produces a mechanical drive connection between the turbine and the propeller and, when disengaged, permits a hydrokinetic drive connection between the turbine and the propeller. The clutch 38 is uncoupled or unlocked and the torque converter is opened when the CBY pressure in line 40 is applied to the space between the propeller housing and the friction surface of the clutch 38 which engages the case 28. The pressure of CBY is greater than the pressure of Cl in line 46. Line 44, at a pressure of CT, is consumed through an oil cooler 126, the pressure of Cl in line 46 is supplied to the inlet of the converter Torque through the hole 122 when the clutch 38 is disengaged.

Secondary Regulated Pressure Valve A temperature-compensated pressure limiting valve 52 produces an output, an SRPX pressure carried on line 82 to the anti-consumption back pressure valve 78, whose output, the supply pressure TCF of the torque converter of torque is carried on line 88 to the regulator valve 86 of the converter. The secondary regulated pressure, controlled by valve 52, is carried through line 54. Valve 52 includes a spool 56 pushed by a spring 58 to the right in the valve bore., whose movement to the right is limited by contact of the control projections 60 against the valve body. The SRP feedback pressure on line 62 enters the valve through a hole 64 with sharp edges. The radial space between the shoulders 60 and the perforation of the valve defines a laminar orifice, which extends along the axis of the valve 52 from the feedback hole connected through the line 62 to the vent hole 66. Preferably, the diameter of the orifice 64 is 1.0 millimeter, the diameter of the protrusions 60 is 14,994 millimeters, and the diameter of the perforation adjacent the protrusions 60 is 15,019 millimeters. Through this discussion, a fixed or sharp-edged orifice means a restricted hydraulic passage through which the flow rate varies non-linearly, with a pressure drop through the orifice, approximately as the square root of the pressure drop , and the flow rate varies almost linearly with the temperature of the fluid, such as the commercially available hydraulic fluid from the transmission that flows through the orifice. A laminar building means a restricted passage through which the flow rate varies linearly and directly with the pressure drop through the orifice, and exponentially (or logarithmically) with the temperature of the fluid flowing through the orifice. The valve 52 further includes control projections 68, 70; an inlet port 80 of SRP, an outlet port 81 of SRPX; a supercharge output hole 74 connected via line 76 with the supercharging relief valve 78. The relief valve 52 is normally closed by the spring 58 which causes the spool 56 to move towards the right-hand end of the valve, while the flow rate from the pump 16 is so low that the pressure SRP is relatively low . In that position, the line 76 is closed by the ledge 68 from the SRP line 54, and the converter power line 82 is closed by the ledge 70 from the SRP line 54. The power line 82 of the converter is connected through the orifice 75 to the line 54 of the SRP. As the flow rate of the pump 16 and the pressure SRP are raised, the control pressure at the right-hand end of the spool 56 first opens the output port 81 of SRPX, thereby connecting the 54 line of SPR with anti-consumption backpressure valve 78 through line 82. The SRPX pressure on line 82 moves the spool 84 of anti-consumption backpressure valve 78 to the left, thereby connecting the TCF pressure of torque converter on line 82 with converter 86 regulator valve through line 88. As the SRP still elevates further, the projection 68 regulates the SRP in hole 74 so that the SRP fluid is connected to line 76, nozzle 24, check valve 18 and line 144. The feedback chamber at the right-hand end of the valve bore 52 is discharged through a laminar orifice 60 from to This resistance is fed through a fixed orifice 64 insensitive to viscosity. At fluid temperatures of the automatic transmission less than 66 ° C, the flow through the laminar orifice is negligible; therefore, the constant state differential pressure through the fixed orifice is negligible. At fluid temperatures greater than 93 ° C, the exhaust through the laminar orifice 62 increases. In this way, a pressure divider is established and the flow of the feedback pressure through the valve 52 is therefore reduced as the temperature rises above 93 ° C in proportion to the hydraulic resistance values. of the two holes 60, 64.

Regulator Valve of the Converter The regulating valve 86 of the converter clutch with three numbers of operation or operation: the operation of the converter with the clutch disengaged or open; operation of the converter with the clutch engaged or locked; and the modulated sliding or partial coupling of the clutch 38 of the torque converter. A variable pressure TCC signal is carried on line 90 to the right-hand end of valve 86 from a solenoid-operated valve 92 of the converter clutch. The magnitude of this pressure signal is proportional to a predetermined clutch torque capacity and a pulse width modulated PWM service control signal produced by a microprocessor and applied to the solenoid of valve 92. The valve 86 modulates the differential pressure across the friction surfaces of the clutch 38, in proportion to the required TCC pressure. The valve 86 includes a spool 94 movable within the valve bore and bearing four control projections 96, 98, 100 and 102. The valve sleeve 104 is fixed in position in the valve chamber by a retainer, the sleeve holding a reinforcing spool 106, which is pushed by the feed pressure TCF of the torque converter to the right against the end of the valve. left hand of reel 94. A vent hole 108 communicates with the valve chamber and is opened and closed by control projection 102. A compression spring 110 pushes the spool 94 to the right inside the valve chamber. The line 88 carries the feed pressure of the torque converter to the passage 112, and through the hole 114, to the bore or chamber of the valve. The passages 112, 118 and 120 connect the line 88 to the valve chamber, in mutually separated positions. The line 40 connects an outlet orifice of the valve 86 with the passage through which the clutch 38 disengages. The line 44 connects the return line from the torque converter directly to the discharge line 113, 114 of the torque converter and through the lines 116, 119 which are connected to the orifices of the valve 86. The line 46 carries the fluid at the supply pressure of the converter to the torque converter 20 through the valve 86. The torque converter 20 is opened, that is, the bypass clutch 38 is released when the PWM duty cycle supplied to the solenoid of the valve 92 driven by the clutch solenoid of the converter is zero, reducing this In this case, the supply pressure of the torque converter operating at the left hand end The reel of the spool 106 forces the spool 94 towards the extremity by hand to the right of the valve chamber. In this position, the valve 86 connects the line 118 with the line 40, thereby pressurizing the space between the cover 28 from the impeller and the friction surface of the clutch 38. The valve 86 connects the line 120 through the orifice 122. with line 46 through which, the hydraulic fluid is supplied to the torsion converter bocel. The fluid at the outlet of the nozzle, carried on line 44, enters the valve chamber through lines 116, 119 and is carried on the converter discharge line TCX to the oil cooler 126, through of the supercharged consumption back pressure valve 78. The spool 84 of the valve 78 will have moved towards the left-hand end of its chamber, against the effect of the compression spring due to the presence of the SRPX pressure at the right-hand end of the spool 84, as described in FIG. the foregoing with reference to the operation of the valve 52. A displacement valve 200 1-2 connects a source of the regulated line pressure IX to the line 128 when the first speed ratio is selected. A valve 130 for increasing lubrication and interlocking the converter includes a spool 132, which moves to the left inside the valve chamber due to the effect of the compression spring 134 and the pressure force developed in the protrusion 136, when the line 128 is pressed. With the valve 130 in this position, the fluid in SRP carried on line 54 from valve 52, and through line 138 to lock valve 130 of the converter, is connected through valve 130 with a line 140 of UNLOCKING which is connected to the chamber of the regulator valve 86 of the converter in a hole positioned between the spools 106 and 94. When the lines 140 and 88 are pressed, there is no differential pressure across the spool 106 and the spool 94 moves towards the right-hand end of the chamber of the valve, due to a pressure force applied to the large pressure area at the left-hand end of the projection 102. This action moves the spool 94 to the right to the same position as the described above with respect to the operation of the open torque converter. Under this condition, the clutch 38 of the torque converter is disengaged and the torque converter 20 operates in an open condition. In this way the valve 86 provides a locking force independent of the large diameter of the projection 102 to ensure that the vehicle can be started and driven at a first speed change in the open converter, even when an obstruction is present in an orifice. the valve 86, whose obstruction could otherwise prevent the spool 94 from sliding to the right-hand end of the valve chamber. This interlocking feature also allows the torque converter to operate in an open condition even when a failure of the solenoid 92 or the microprocessor control system causes the pressure in line 90 to be elevated. The low pressure in line 90 it would be expected during normal operation, as mentioned above. In that case, the SRP pressure operating at a larger spot on the left-hand side of the reel 94, counteracts the effect of the pressure present in the line 90 and allows the carretre 94 to move towards the open condition in the end on the right side of the camera. This avoids the decrease of the motor speed in the reverse speed change or driving conditions in a low speed change ratio. In order to operate the torque converter 20 in the locked condition, the clutch 38 is coupled due to the presence of a larger pressure in the torque converter than the pressure in the space between the drive box and the surfaces of clutch friction 38. The torque converter operates in an interlocked condition when solenoid-operated valve 92 produces a pressure of approximately 3.52 kilograms per square centimeter gauge on line 90 thereby moving spool 94 toward the end left hand of the valve chamber. The spool 94 moves to the left-hand end of the chamber when the UNLOCKING pressure line 140 closes in the valve 130, due to the absence of the pressure IX from the displacement valve 1-2 and due to the force of larger pressure acting on the right-hand end of the projection 96 compared to the pressing force on the left-hand end of the booster 106 produced by the TCF pressure. With the valve positioned at the left-hand end of the chamber, line 88 is connected directly through line 118 and through line 120 and port 122 to the torque converter boder through the line 46. The fluid placed between the case 28 of the propeller and the clutch 38 is discharged into the reservoir via the line 40 and the vent hole 108, thereby producing a differential pressure across the friction surfaces of the clutch 30 forcing the same to a coupled or locked condition. The fluid of the torque converter returns through line 44 to line 113, which directs the TCX discharge of the torque converter to the cooler 126 through the valve 78.

Microprocessor Controller Figure 6 shows a microprocessor that is used to control the valve circuits which in turn control the distribution and discharge of the actuating pressure to the clutches and servo brakes for the transmission. The processor is shown at 170 in Figure 6. As depicted schematically in Figure 6, an air charge temperature sensor 172 is adapted to develop an ambient air temperature that is used by the processor to develop the -1! controls sent to the control valve system. The processor also responds to a signal from the air conditioning clutch from the sensor 174 which indicates whether the air conditioning system is connected or disconnected. An on / off brake switch 176 is activated by the vehicle brakes and the on / off signal is supplied to the processor. An engine speed sensor 178 measures the speed of the crankshaft. The engine coolant temperature is detected by the temperature sensor 180. The drive scale that is selected by the operator is indicated by a manual lever position sensor 182. A speed sensor 184 of the output arrow of the transmission provides an indication of the speed of the driven arrow, an output arrow. This speed is related to the speed signal to the vehicle developed by the sensor 86. An oil temperature signal is supplied from the transmission to the processor via the sensor 188. A motor regulation position signal is supplied to the processor via the sensor 190 The control valve circuit includes solenoid operated shift valves that receive displacement signals. These are the variable force signals from the processor. They are received by the displacement solenoid 192-195. Sensor inputs, such as engine-related sensor signals indicative of engine coolant temperature, absolute barometric pressure, etc., are used by the processor to develop more accurate outputs as load conditions change and weather. Other inputs are based on driver controls, such as the motor's regulation position. Still other inputs to the processor are developed by the transmission itself, such as the speed sensor signal of the output shaft, the manual lever position signal and the transmission oil temperature signal. The processor will develop an appropriate travel time and conditions for the displacements in the relationship as well as control of the application and release of the clutch. The line pressure is also developed by the processor to establish an optimum displacement sensation. The processor is an integrated central processor that converts signals, such as signals from a vehicle speed sensor and a motor throttle position sensor, a motor temperature sensor, and a turbine speed sensor and a manual selector lever, in electrical signals for the solenoid-operated valves 192-196, the solenoid valve for the bypass clutch 92 of the converter and the variable force solenoid for the electronic pressure control 25. The processor receives the signals from the sensor and operates on them in accordance with the programmed control algorithms. The processor includes appropriate gates and driver circuits to supply the operation output of the algorithms to the hydraulic solenoid control valves. The processor 170 includes a central processor unit (CPU); a read-only memory (ROM) wherein the control unit includes a read-write memory or RAM; and internal buses between the memory and the arithmetic logic unit of the central processor. The processor performs the programs that are obtained from the memory and provides the appropriate control signals to a valve circuit as the conditioning portions of the processor's input signal reads the input data, the logical calculation portions supply the results of the calculation to the output drive system under the control of the program. The memory includes both a random access memory (RAM) and a read-only memory (ROM), the latter storing the information comprising the control logic. The result of the calculations carried out in the input data is stored in the RAM where it can be addressed, erased, rewritten or changed depending on the operating conditions of the vehicle. The data that is stored in the ROM memory can displace the information or functions of the project, where two variables work, such as the position of the regulator and the speed of the vehicle that are related to one another in accordance with a displacement function. The data may also be in the form of information in a table containing three variables or data, such as a value of the synchronizer and values for the other two pieces of data or variables. The control strategy for the transmission is divided into several routines and control modules that are carried out in sequence in a known manner, during each background step. The strategy for each module is therefore executed in a sequential manner just as the modules themselves execute in a sequential manner. The different data registers are initialized as the input data from the aforementioned sensors are input to the conditioning portion of the processor input signal. The information that results from the admission of the sensor data together with the information that is stored in the memory and that is learned from a previous background step, is used to carry out the control functions of the displacement solenoid valves, the regulator pressure solenoid valve, and the bypass clutch solenoid valve. The modules and submodules are carried out in sequence in each background circuit. Each module or logical portion is independent of the others and carries out a specific function. They are carried out as they are directed separately by the processor pointer. The functions occur after the input signals are received by the input gates, and the signal conditioning portions of the processor and after the conditioning of the input signal has occurred. The capacity of the clutches and brakes to transmit the torque depends, of course, on the level of the pressure maintained in the control circuit by the main pressure regulator. This control is different from the TV pressure controls of the conventional transmissions that depend on the mechanically controlled valve links to maintain a desired regulating valve pressure or a vacuum diaphragm that is operated by the manifold pressure. engine intake. The TV control in the present design is achieved by a variable force solenoid valve that responds to a signal developed by the electronic microprocessor. The electronic TV strategy for the processor includes the step of looking for the torque of the motor from a frame and appropriately varying the signal supplied to the variable force solenoid to adjust the transmission capacity of the transmission torque.

Inverter Interlock Valve A converter interlock valve 130 and lubrication increase is supplied through line 128 with pressure IX from displacement valve 200 1-2, which connects a source of regulated line pressure to the line 128 in accordance with the control pressure from the solenoid valve 195, when operation is required at the first advance speed change. Alternatively, the line pressure can be directed through line 128 or another line from a manual valve 202 when the operator of the vehicle selects an operation within the reverse scale. The supercharging pressure SPS is carried on line 144 to an orifice positioned near the left-hand end of the valve chamber 130. The supercharging pressure is regulated by the supercharging relief valve 79 to approximately 3.51 kilograms per square centimeter gauge and applied to a control shoulder of the valve 130, which is approximately five times larger than the other control projections formed on the spool 132, where the pressure signals function to control the position of the spool 132. The pressure Regulated secondary SRP is carried on lines 54 and 138 to valve 130. Valve 130 is also supplied through lines 142, 204 with pressure D321 from a manual valve 202, a source of line LP pressure is connected regulated on line 24 with line 204 when the manual valve is moved by the operator movement of the scale selector vehicle (PRNDL) to any of the forward driving positions. The absence of pressure D321 is an indication of a reverse drive operation of the transmission, that is, the low pressure on line 142 indicates that the vehicle operator has placed the scale selector lever of PRNDL on the R scale. The fluid exit from the valve 130 is carried on the line 146 through the orifice 148 and the filter 152, towards the different lubrication circuits 147-150, deviating from a hole 154 compensated in temperature at which the fluid is taken from the valve 130 through line 156. Line 140 carries the RELEASE pressure towards a valve orifice 86 positioned between reinforcing spool 106 and rib 102 of spool 94. Compression spring 134 pushes spool 132 and projections control large spool 206 to the left in the valve chamber. An object of the valve 130 is to prohibit the engagement of the clutch 38 for an inappropriate period of time, such as when the forward and reverse couplings are initiated, however, engagement of the clutch 38 must be allowed on all the forward scales. and at low engine speeds when the transmission is running at the second, third, fourth and fifth gear changes. Essentially the interlocking valve 130 compares three hydraulic pressure signals D321, IX and SPS and produces a low pressure high pressure signal on the line 140, which is applied to the regulator valve 86 of the converter, representing the high pressure signal a UNLOCK control signal.

During conditions when the manual selector is in the parking, reverse or neutral positions, and the engine speed is at a vacuum speed or at a speed of less than 2,000 revolutions per minute, the pressures D321, IX and SPS are at a magnitude low; therefore, the spool 132 moves towards the left-hand end of the valve chamber, thereby opening a connection between the pressure line 138 and the secondary regulator and the UNLOCKING line 140. The UNLOCK pressure causes the spool. 94 of the converter regulator valve 86 moves to the right-hand end of its valve chamber, thereby opening a connection between the power line 88 of the torque converter and the line 40, through which the pressure is applied to the space between the propeller cover and the friction surfaces of the clutch 38. This action disengages the clutch and opens the torque converter. When the transmission is operating on the D scale of the first speed change at an idle speed of the engine or at an engine speed of less than 2,000 revolutions per minute or in the ratio of the first manually selected speed change to a lower engine speed of 2,000 revolutions per minute, the pressure D321 tends to cause the spool 132 to move to the right and the pressure IX tends to move the spool to the left. Therefore, since the pressures D321 and IX are essentially at the same pressure magnitude line and the pressure SPS is low, the position of the spool 132 is determined by the effect of the spring 134, thereby opening the line 138 of SRP to the UNLOCKING 140, and the clutch 138 disengages as described immediately above. With the transmission running on the R or reverse scale with the engine speed above 3,000 revolutions per minute or on the D scale driver at the first speed change or the engine speed greater than 3,000 revolutions per minute, the D321 pressures and IX have essentially the same magnitude and virtually no net effect on the position of the spool 132. But the pressure of SPS (approximately 3.51 kilograms per square centimeter gauge or greater) operating in the projections 206 moves the spool 132 to the right against the effect of the spring 134. As the engine speed rises to more than 3,000 revolutions per minute, the SPS pressure increases in order to save energy; therefore, the pressure force related to SPS at the end of the shoulder 206 increases and moves the spool 132 towards the right-hand end of the valve chamber.

This action closes the communication between the SRP line 138 and the UNLOCK line 140; therefore, the regulator valve 86 of the converter operates as described above when the RELEASE pressure is absent from the left-hand end of the reel 94. With the transmission operating at the second to fifth speed change in the scale of the thruster and with the engine speed greater than 3,000 revolutions per minute, the pressure IX is absent at the right-hand end of the reel 132, the pressure D321 is present at the left-hand end of the reel, and the SPS pressure operates at the projections 206 for moving the spool 132 toward the right-hand end of the valve chamber, thereby closing and opening the pressure line 138 SRP to the UNLOCKING line 140. When the manual speed selector is on the D scale, and the transmission operates at the second to fifth forward speed ratios with the engine speed within the range of 800 to 1,200 revolutions per minute, the SPS pressures and IX are low or absent in the valve 130, but the pressure D321 forces the spool 132 against the spring 134 towards the right-hand end of the valve chamber, thereby closing the connection between the SRP line 138 and the DISPLACEMENT line 140. In this position, the regulating valve TC works as described above in the absence of the UNLOCKING pressure so that the converter clutch either opens or closes in accordance with the pressure control signals on the valve 86. The The UNLOCKING line 140 is discharged through the hole 160, when the spool 132 moves towards the right-hand end of its valve chamber. The flow rate to the lubrication circuits 147-150 is relatively low at idle engine speeds, but as the speed of the output shaft of the transmission rises, the lubrication requirement increases. An object of the control strategy is to prevent the interlocking of the torque converter when the lubrication requirement is low. To produce this effect, when the spool 132 moves to the left, as it is when the engine speed and the SPS pressure are low, the flow of the fluid through the line 156 is closed by the spool 132 from a connection with the line 146, thus preventing any increase in lubrication flow through line 146 to the lubrication circuits 147-150. With this condition the interlocking of the torque converter is prohibited.

However, when the engine speed and SPS pressure are increased, the spool 132 moves to the right-hand end of the valve chamber thereby opening a connection between the lubrication line 156 and line 146. action increases the flow to the 147-150 lubrication circuits. In this condition, the torque converter will operate either in the locked or unlocked mode, depending on the effect of the various pressure control signals on the valve 86, but with the UNLOCKING pressure discharged to the drain.

Clutch Capacity Pressure Regulator The solenoid operated line pressure valve 25 produces a LPC line control pressure signal preferably in the form of several abrupt changes in magnitude or alternatively as a linearly increased magnitude carried in the line 210 to the left-hand end of the clutch capacity pressure regulator CCPR valve 212. The LPC is regulated by applying a variable voltage or solenoid of the valve 25, a signal produced as an output by the microprocessor 170 in response to the result of a control algorithm carried out by the microprocessor. The pressure D321, a control pressure signal is carried on the line 204 to the differential area of the projections 214, 216 of control and produces a pressing force that tends to move the spool 218 counterclockwise against the effect of the spring 220. The fluid in the SRP is carried on the line 222 to the valve 212 and on the line 224 to the valve 25 of line pressure powered by solenoid. The line pressure is carried to the valve 212 through the line 226 towards a hole that is opened and closed by the projection 228 towards the SPS excess relief line 230, which is connected through the valve 52, the line 76, the supercharging relief valve 79 and the nozzle 24 with the suction side of the pump 22. The check valve 231 alternately opens a connection between the SRP line 222 and the line 226 when the spool 218 and the highlight 28 move to the right inside the valve chamber, or close that connection when the line pressure exceeds the SRP magnitude. During operation, when the vehicle operator moves the scale selector to the driving scale from the neutral or reverse scales, several friction elements, possibly from one to three hydraulically operated clutches or brakes, must be filled and operated quickly at a pressure of approximately 2.81 kilograms per square centimeter gauge in order to place the clutch elements to complete the change in speed ratio in approximately 250 to 500 milliseconds. As the friction elements are filled and operated, the line pressure decreases due to the requirement of high or sudden flow; therefore, the spool 218 moves towards the right-hand end of the valve chamber because the line pressure fed back toward the end of the spool is less than the effect of the other forces acting on the valve , including the force of the spring 220. When this occurs, the valve 212 stops releasing the line pressure by closing the connection between the lines 226 and 230 by moving the shoulder 228 through the corresponding holes. Then, virtually all of the flow produced by the pump 22 is directed to the friction elements, which include a forward clutch, a reversing servo system, an intermediate clutch, a direct clutch and an overdrive clutch. However, the friction elements require a larger volume than can be supplied from the pump 22, so that the magnitude of the line pressure continues to decrease enough for the forces acting on the valve spool 218 to be insufficient to prevent the spring 220 moves the spool 218 entirely towards the right-hand end of the valve chamber. With the valve positioned in this manner, the boss 228 continues to close the connection between the lines 226 and 230, but opens a connection between the SRP line 222 and the line 226 through the check valve 231. After this connection is opened, the demand for the flow of the friction element is connected to the outlet of the pump 16 which produces a high flow rate. In this way, the flow produced by the pumps 16 and 22 is combined to supply the friction elements. As a result of the SRP being supplied to the friction elements, the magnitude of the pressure SRP decreases, thereby allowing the spool 56 of the secondary regulated pressure valve 52 to move towards the right end of the valve chamber to close the connection between lines 54 and 88, through which the clutch 38 of the torque converter is supplied. This action decreases the flow rate of the fluid carried on line 88 through valve 86 and line 40 to the space between the thruster housing and clutch 38. As the pressure on the friction elements of Inlet, the line pressure rises and the spool 214 moves to the left inside its valve chamber, first closing the connection between the lines 226 and 222 so that the flow rate from the pump 16 is then supplied to the regulator valve 86 of the torque converter through lines 54, 82 and 88. Eventually, as the pressure in the input friction elements and the line pressure rises sufficiently high, the spool 214 moves towards the left hand end of the valve chamber until the ledge 228 opens a connection between line 226 and 230, allowing excess flow to be released and supplied to the inlet. a of the bomb 22.

Claims (7)

R E I V I N D I C A C I O N E S:

1. In a transmission having multiple speed ratios a system for producing a pressure signal whose magnitude represents the latched and non-latched operation of a converter clutch comprising: a first pressure source representing the forward driving operation of the transmission; a second pressure source representing the operation of the transmission in a first forward speed ratio; a source of regulated pressure; a third pressure source having a scale of magnitude that varies in response to the speed of the motor; an exit hole; an interlocking valve means for producing interlocking pressure of the converter having a first quantity representing a command for unlocking the converter by opening a connection between the source of the regulated pressure and the outlet orifice, and a second quantity representing a control to lock the converter in response to the effect of the first, second and third pressure sources.

2. In a transmission having multiple speed ratios, a system for producing a pressure signal whose magnitude represents an interlocked and unlocked operation of a converter clutch, comprising: a first pressure source representing the forward driving operation of the transmission; a second source of pressure representing the operation of the transmission in the first forward speed ratio; a source of regulated pressure; a third pressure source having a scale of magnitude that varies in response to the speed of the motor; an interlock valve comprising an outlet orifice, a reel movable in a chamber, the reel has control projections in which the first control forces that represent a requirement that the converter clutch engage are produced by the presence of the first and third pressure sources, and the second control forces represent a requirement that the clutch of the converter unlock, are produced by the pressure of the second pressure source, the first and second control forces act in mutual opposition, the spool has a means for opening and closing a connection between the source of the regulated pressure and the outlet orifice in response to the relative magnitude of the first and second control forces. The system according to claim 2, wherein a connection between the source of the regulated pressure and the outlet orifice is closed when the first control forces exceed the second control forces, and a connection between the source of the pressure of action and the exit orifice is opened, when the second control forces exceed the first control forces. The system according to claim 1, wherein the interlocking valve means comprises: a valve body defining a valve chamber, communicating with the outlet orifice, the source of the regulated pressure and the first , second and third sources of pressure; a spool slidable in the valve chamber, the spool has multiple control projections that include a first control shoulder communicating with the first pressure source and which is adapted to have a first control force applied thereto, a second control highlight communicating with the second pressure source and adapted to have a second control force applied thereto, a third control shoulder communicating with the third control source and adapted to have a second control force applied to the control source; same and a fourth control shoulder adapted to open and close a connection between the regulated pressure source and the outlet orifice, in accordance with the position of the spool. The system according to claim 4, wherein the interlocking valve means further comprises a spring for pushing the spool to a position where a connection between the regulated pressure source and the outlet orifice is opened. 6. The system according to claim 4, wherein the interlocking valve means comprises a vent hole and means for opening a connection between the outlet orifice and the vent, when the first control forces exceed the second control forces. The system according to claim 4, wherein the interlocking valve means further comprises: a spring for pushing the spool to a position where a connection between the regulated pressure source and the outlet orifice is opened.; and a ventilation hole; and means for opening a connection between the outlet orifice and the vent when the first control forces exceed the second control forces. the operation of the clutch in response to the control forces applied to the reel corresponding to a clutch operation of the locked drive.