DE2001941A1 - Shift control system for automatically shifting transmission - Google Patents

Abstract

1,261,471. Change-speed gear. TOYOTA JIDOSHA KOGYO K.K. 5 Jan., 1970 [25 March, 1969], No. 390/70. Heading F2D. Fluid - pressure engaged ratio - selecting clutches and brakes, in a two or three speed and reverse automatic transmission on a motorvehicle, are controlled in response to electric signals representing output speed and enginethrottle setting, and provision is made for two different conditions of vehicle operation; one set of shift lines catering for operation on level roads, the other for mountainous terrain. Change between one condition and the other is automatic in response to a gradient-detecting device, which functions by measuring the acceleration of the vehicle at pre-set limits of throttle opening and output speed. Function summary.-Although a two-speed gear may be used, the only embodiment described is a three-speed gear, with a manual ranging valve 120 having settings PRND2L; L providing a fixed, two-way low; 2 a similar second; and D automatic shift between oneway low, second and third ratios, under control of 1-2 and 2-3 shift-valves operated by electric signals responsive to output speed and throttle setting. The acceleration control, above referred to, functions between second and third ratios only. Servo pressure augmentation is provided in reverse, and also, to a lesser degree in low, or also low and second. Gear arrangement.-The three-speed and reverse gear comprises triple planet steps 11, Fig. 2, meshing an output sun 19 and input suns 9, 10 (the latter through a planetary idler) driven through an input torque-converter 2 and selector clutches 6, 7 respectively. The front clutch 6 is engaged to drive the rear sun 9 in all forward ratios; first being by holding the planet carrier by a one-way detent 23 in D setting or by a rear band-brake 21 for two-way manual low; second by applying a front band-brake 22 to the front sun 10; and third by both clutches 6, 7 for lock-up. Reverse uses the rear clutch 7 and rear brake 21. Fluid pressure supply and regulation.-A single input-driven pump 101, Fig. 4, supplies the system main 121 and a pressure regulating valve 105 loaded by a spring 106 and fluid pressure in three chambers as follows. Load chamber 108 receives delivery pressure 121 for constant output pressure; load chamber 107 is fed from a manual valve line 128 in R setting for reverse pressure augmentation; and negative load chamber 109 is fed from a line 134b pressurized by upshift of the 1-2 shift valve 130 (described below), or alternatively of the 2-3 shift valve 135, to reduce system pressure on entering second or alternatively third ratio in D or 2 setting of the manual valve. Three pressure levels are thus established, the highest being for reverse, the lowest for ratios two and three, or alternatively three only. Shift valves.-Automatic 1-2 and 2-3 shift valves 130, 135 are each downshifted to the left, against opposing springs by energizing solenoids 132, 137 respectively. Starting in D setting with the front clutch 6 pressurized through the manual valve line 124, the remaining servos are exhausted at the shift-valves, their solenoids being energized. At a given signal, representing output speed and engine throttlesetting, the solenoid 132 is de-energized and the 1-2 valve 130 upshifts to the right, pressurizing the front brake apply chamber 22a for second ratio. A further signal de-energizes the solenoid 137 to upshift the 2-3 valve 135, pressurizing a line 139 leading to the rear clutch 7 and release chamber 22b of the front brake, for third ratio. This line 139 is isolated by a ball check-valve 141 from a line 128 used to engage the rear clutch in reverse. Electrical control.-In the electric circuit, Fig. 12, the 1-2 and 2-3 shift-valve solenoids are shown at 132, 137 respectively, and are energized for downshift and de-energized for upshift. The two control parameters are a throttle position detector 200 and an output speed detector 320. Throttle position is detected by a potentiometer (Fig. 17, not shown) having a slide operated through a cam by the engine accelerator pedal to supply a signal line 210. Speed is detected by a polarized pick-up adjacent a notched wheel (Fig. 18, not shown) rotating with the output shaft, the pick-up output being processed in an amplifier, (Fig. 19, not shown), amplitude limiter for wave-shaping, and a converter producing a D.C. voltage output 212 responsive to output speed. A primary circuit 202, 220 controls level road shifts, and a secondary circuit 221 changes the shift speeds for gradient operation in response to a further parameter, acceleration, obtained by differentiating output speed with respect to time. The primary level road, shift control comprises similar 1-2 and 2-3 shift circuits 202, 220 respectively. Each comprises a selective switching circuit 327, the output signal 217, representing speed, of which is taken either directly from the RPM line 212 or from a RPM modulator 326 under control of a feedback line 219, the voltage of which, when cancelled by an upshift signal, switches the selection circuit to the RPM modulator 326 so that return downshift is at a lower speed for hysteresis. The speed signal 217 and throttle-setting signal 213 feed a shift-point circuit 328, (Fig. 20, not shown), which receives the signals through preset potentiometers feeding a differential amplifier which emits an output voltage signal 218 for downshift when the throttle component exceeds the speed component, the signal being otherwise cancelled, for upshift. The secondary, or gradient, shift circuit 221 is effective between second and thid ratios only, and co-operates with the above-described normal 2-3 circuit 220 through an OR circuit 225. It comprises a gradient circuit 223 in which an AND circuit 349 emits a downshift signal when three signals, as follows, are received simultaneously from a throttle-setting circuit 341, signalling throttle-setting exceeding 1.8/4; a RPM circuit 342 signalling output speed below 1600 RPM; and an acceleration circuit 343, 346 signalling that acceleration is below 0À05 g for more than one second. The AND signal 233 operates a bi-stable memory circuit 224, (Fig. 24, not shown), comprising a multivibrator, to deliver a signal 234 to the OR circuit 225 which energizes the solenoid 137 for 3-2 downshift. The return upshift is effected by the circuit 222 which switches the bi-stable memory circuit 224, to erase the downshift signal, by a signal 228 received from an AND circuit 340 when throttle setting exceeds 0.5/4 and output speed exceeds 1800 RPM. The signal 234 from the bi-stable memory circuit to the OR circuit 225 is effective to erase the signal 235, for upshift, only if a downshift signal has not been transmitted to the OR circuit 225 by the primary shift circuit 220. The acceleration circuit 343 (Fig. 22, not shown) is fed from the output RPM circuit and comprises a low-pass filter and a differentiator which obtains the acceleration term dN/dt, which feeds an acceleration setting circuit 346 (Fig. 23, not shown) including a potentiometer, reference voltage (Zener diode), amplifier and delay, so that a signal 232 is emitted when the acceleration is less than 0À05 g for a period of not less than one second. The setting of the potentiometer or the reference voltage may be varied in accordance with output speed or throttle setting to provide a variable acceleration shift-value covering a range of gradients.

Description

PATE N TA NWA L TE Dr. D. Thomsen H. Tiedtke G. Bühling Dipl.-Chem. Dipl.-Ing. Dlpl.-Chem.

TELEPHONE 0811/226894 TELEGRAM ADDRESS: THOPATENT

Munich 1-6. January 19.7ο-case 19324 Toyota / T 3452

Toyota Jidosha Kogyo Kabushikl Kaisha Toyota-shi (Japan)

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Switching control system for automatic shifting transmission

The present invention relates to a power transmission system for vehicles and in particular a combined electrical and hydraulic control system for use with automatically switching power transmission systems or gear

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drove.

In the case of the automatically shifting transmissions that have hitherto been used generally in self-propelled motor vehicles all the complicated controls one chi Ia31 i der Switching control carried out by means of fluid pressures. For this reason, the signal detection device showed the

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Regular agreements, intbesoniloro by telephone, tsedßrfon written notification Dresdner Bank Munich account 109103 - Postschfickkonia Munich 11 09 74

Conventional automatic transmissions are necessarily complicated in structure and have been disadvantageous in that the signals detected in the form of fluid pressures are subject to errors, so that precise control cannot be expected. Furthermore, it was not easy, the hydraulic actuation circuit in the power transmission system or the transmission improved going beyond any existing function _t and to perform complicated function.

The present invention overcomes these prior disadvantages by providing the switching signal control means electrically controls in such a transmission.

The present invention aims to provide an automatic shift control system for an automatic shift transmission Specify for a motor vehicle with a device for generating a torque responsive to a machine Signal, with a device for generating an on the Vehicle speed responsive signal, with a first calculation circuit for a switching point for generation a toggle signal when the relationship between these two signals meets conditions necessary for a trip on

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a flat road are suitable _r with a second calculation circuit for a switching point having a (Jradienten-Betätigungssehaltungzur generating a switching signal ,. when the means responsive to the engine torque signal "responsive to the vehicle speed signal and. the. The change in the vehicle speed responsive signal or the acceleration of: the vehicle, conditions for the
Upward travel on an incline or travel in mountainous terrain, "with a circuit for generating a switching signal when the signal responsive to the machine torque and the signal responsive to the vehicle speed meet certain, predetermined conditions, and with a bistable Memory circuit and a circuit for providing an output signal when one of the
Output signals from the first and second calculating circuit for a changeover pinpoint are applied to this circuit in order to carry out a changeover of the gear ratio. By using the shift control system described above, various difficulties which occur with conventional, automatically shifting transmissions in which only a changeover scheme is provided for driving on a level road can be eliminated. Let us assume for a moment that a force tfahrisüg, which with a her-

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conventional automatic gearbox is equipped ■ and at a relatively low speed · rich of the third gear of this switching scheme drives, arrives in a mountainous terrain and up a steep incline begins to drive. Since in such an operating state the driving resistance increases due to the gradient and the loading ' acceleration force is low, the accelerator must be depressed to achieve a downshift to second gear to accelerate the motor vehicle, however .will by a subsequent reduction in the force exerted on the accelerator pedal, you immediately switch back up to the causes third gear, which again results in an abrupt reduction in the acceleration force. So it's practical impossible to achieve the desired driving style by moving the accelerator pedal. Through the present invention P eliminates various difficulties that occurred with conventional automatic gearboxes, by providing a switching scheme for driving in mountainous terrain and a switching scheme for driving on a flat road be to variable switching points between the lower and the upper aisle, so that these two shifting schemes can be switched automatically by an actuation circuit which is used to determine a gradient.

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This arrangement can-automatically- for all driving conditions a suitable switching point can be obtained, and it can thus be compared to the conventional automatic switching Transmission improved automatic switching can be carried out. ·,. "

The present invention further aims to provide a to specify automatically shifting shift control system for an automatically shifting transmission for a motor vehicle, with a manually operated adjustment valve for adjustment of the switching area, which has a first position in which a relatively high drive or transmission ratio is turned on in the forward direction, and that has a second position for a relatively low drive ratio in the forward direction to be switched on, with a switching valve that is in · -.a Connection line between the control valve for the position of the switching area and a device acting by frictional engagement is arranged to this through. Optionally to operate the frictional engagement device, with a feather; which acts on one end of the switching valve to this switching valve in a direction leading to a high transmission ratio in the forward direction leads to

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tension. with a solenoid that is in engagement with the other The end of the switching valve stands to the switching valve in the other direction, in which a low gear ratio in the forward direction is obtained according to a current given to this solenoid, with a Switching signal control device through which the switch-on

control and shutdown of the current flowing to this solenoid is given, is determined depending on the driving state of the motor vehicle to the switching valve in the corresponding Direction to move, and with a switching device through which an electrical voltage source is optional can be connected to the switching signal control device, so that this switching signal control device is in the closed Position of the switching device in the first position of the manually adjustable switching range adjustment valve of this

£ Shift valve operated to a high as well as a low Engage gear ratio in the forward direction while this toggle signal controller is in the open Position of the switching device can not perform a control process, and due to the spring of the switching valve is only turned on the high gear ratio in the forward direction. Thus, the driver can if there is any defect occurs in the switching signal control system, the switching device

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switch to its open position and operate with manual control go on; by entering the first and second positions of the " Hand adjustable reversing range adjustment valve used. However, even if there is no defect in the switch signal control system, the driver can put the switch in its open position Take position if he is a sporty driving style with hand

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.switching wishes. In this case, he can select the drive or ^m ratio freely as desired. This means that by turning the switch on or off, you can choose a driving style with fully automatic switch control or a driving style with manual switch control.

In the following, the invention will be explained in more detail with reference to preferred embodiments shown in the drawing. In the drawing shows:

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1 shows a block diagram of an automatically shifting transmission with an automatically shifting switching signal control system according to the present invention;

i. 2 is a schematic sectional view of a transmission unit in the automatic: shifting gearbox j

3 is a partial sectional view taken along the line

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A-A in Pig. 2, in which iin detail the arrangement between a free-running, in Pig. 2 not shown, gear, a Reverse sun gear and a planetary gear is shown;

Pig. 4 "to 10 are schematic representations in which the . Operation of a hydraulic actuation circuit is illustrated when the present invention is applied to an auto-shift Transmission with three forward gears is used where the hydraulic actuation circuit in the individual Piguren in their N-position, D-position first gear, D-position second gear, D-position third gear, 2-position second gear, L-position or R-position is shown;

Pig. 11 is a diagram showing how the line pressure P ^ created by the hydraulic loading ™ actuation circuit is controlled in relation to the speed of rotation of the output shaft changes;

Pig. 12 is a block diagram of the shift signal control system in accordance with the present invention;

Pig. 13 is a block diagram similar to Pig. 12, in which, however, the system is in its control position for the first

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Gear is shown

Pig. 14 a block diagram similar to Pig * 12, but in which the system in its control position for second gear is shown;

Pig. 15 is a block diagram similar to Pig, 12, but in which the M system is shown in its control position for third gear; ,

Pig. 16 is a block diagram showing how a logical operation for downshifting, from the third Gear to the second gear is carried out according to a signal that is generated by a calculation circuit for a second ' Shift point is released while third gear is engaged;

Pig. 1? a schematic view in which the structure of a device for determining the position of the throttle valve is shown; *

Pig, 18 is a schematic view in which the structure of a device for peat setting the speed of an output

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output shaft is shown; ■ ■

Pig. 19 is a block diagram showing the structure of a circuit for the speed signal of the output shaft is shown;

Pig. 20 is a block diagram showing the construction of a switching point operating circuit shows;

Pig. Fig. 21 is a block diagram showing the construction of a setting circuit;

Pig. 22 is a block diagram showing the construction of an acceleration detection circuit shows;

™ Pig. 23 is a block diagram showing the structure of a through

shows the acceleration adjustable circuit;

Pig. Fig. 24 is a block diagram showing the construction of a bistable memory circuit;

Pig. 25 is a diagram showing an example shows for the switching areas; and

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Pig. 26 a graphic: representation,: the- one. Paragraph setting area to show the operation of a gradient circuit. ·. . ,

In Pig. 1 is an automatically shifting gearbox that the present invention is applied, shown in a block diagram, and this comprises, an electrical ■ voltage source 500, a shift signal control system 501, a hydraulic one Actuation system 502, a gear unit 503 and a switch 95 that the switching signal control system 501 with the electrical voltage source 500 connects.

The components of the automatically shifting transmission are described in more detail below.

Structure of the transmission

An automatically shifting torque converter transmission with three forward gears and one reverse gear as shown in Pig * 2 should be taken as a typical example of the automatically shifting transmission. In Pig. 2, the structure of such a fluid-controlled, automatically retaining transmission 8 is shown schematically. \ ^: -

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A torque converter contains an impeller 2 which is directly connected to a crankshaft 1 of an engine. The power output by the machine is given by the pump wheel 2 to a turbine wheel 3 via the hydraulic fluid medium, and the fluid is returned to the pump wheel 2 by being passed through a stator 4. A rotating force can be continuously taken off at a turbine shaft 5 by repeating the above-mentioned fluid flow. This rotating force is transmitted from the turbine shaft 5 to a gear unit which is arranged on the output side of the torque converter unit. As is well known, multi-disc clutches 6 and 7 and brake bands 21 and 22 are automatically controlled by fluid pressure which is delivered to auxiliary devices associated with it as required, and these devices cooperate with a planetary gear to engage three forward gears and one reverse gear.

The following describes the structure of the transmission unit which is arranged on the output side of the torque converter . The turbine wheel 3 is connected to the turbine shaft 5, which acts as a power input shaft of the planetary gear. The turbine shaft 5 is via claws

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a Kei internal toothing connected to a drum 24 so that it is rotatable together with this. In the drum 24 there is a multiple disc clutch 6 (which will be referred to as the front clutch in the following), which is engaged with the aid of a pressure basket 25, which is actuated by fluid pressure, and is disengaged with the aid of a return spring of the front clutch 6 are provided with outer claws engageable with a clawed inner part of the drum 24, and the clutch plates are clawed on the inside so that they are in engagement with one on the outside So that they can be locked against free rotation, the hub 26 is clawed on the inside so that it is ^{brought into engagement with the clawed part 1 of} an intermediate shaft 8 The clutch disks of a multiple disk clutch 7 (which will hereinafter be referred to as the rear clutch) are provided with claws on the inside so that they can be brought into engagement with a part of the front clutch drum 24 which is provided with claws on the outside, as shown in the drawing, so that these are locked against free rotation. The clutch disks thus rotate

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the rear clutch 7 together with the front clutch drum 24. The driven plates of the rear clutch 7 are clawed on the outside so that they can with a part of a clutch drum 27 of the rear clutch 7 provided with claws on the inside is brought into engagement can be. The rear clutch 7 is engaged with the aid of a pressure piston 28 actuated by a fluid pressure and disengaged when the fluid pressure applied to the pressure piston 28 is switched off.

The central shaft 8, which is splined with the hub 26 of the front clutch 6, is at its rear end connected to an input sun gear 9. The rear clutch drum 27 is on a reversing sun gear 10 with the help of a suitable Fastening device attached. The input sun gear 9 is in mesh with each gear 12 of several, e.g. B. two or three, PlaHsben gears 11. The reversing sun gear 10 meshes with three running gears 15 (shown in 'Fig. 3) are), which are each rotatably arranged on an axis 14, which is fastened at one end to a carrier 13 -i.st, and the free-running gears 15 mesh with gears 16 or the planetary gears 11.

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The rearmost gear 17 of each planetary gear 11 meshes with a gear 19 which is on the front end of an output shaft 18 of the; Power transmission system or the [gearbox is attached. The planetary gears 11 with the gears 16, 12 and 17 and the free-running gears 15 are held by the carrier 13 with the aid of gear axles 20 and 14, respectively. A brake band 21 (hereinafter referred to as the rear brake band) comprises the carrier 13 to apply braking thereto so that the carrier 13 can be secured against rotation or free running by tightening and loosening the rear brake band 21. Similarly, a brake band 22 (hereinafter referred to as the front brake band) comprises the rear clutch drum 27 so that the rear clutch drum 27 _y and consequently the sun gear 10, d-by tightening and loosening the front brake band 22 can be secured against rotation or allowed to rotate freely. A one-way clutch 23, which is assigned to the carrier 13 in a low gear _/ similar to the rear brake band 21, is intended to

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ter are described below.

, With the help of the above structure, by optional actuation of the components described above in the following Jiei- · three forward gears and one reverse gear are realized: '.

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First gear: the front clutch 6 and the rear brake band 21 are actuated. (However, when the transmission is driven by the engine, the rear brake band 21 need not be operated because the one-way clutch 23 is operated, which gives the same result as when the rear brake band 21 is operated Output shaft 18 does not transmit any drive force). When the front clutch 6 and the rear brake band 21 are operated, the rotation of the turbine shaft 5 is transmitted directly to the input sun gear 9 via the front clutch 6. Since the carrier 13 is secured against rotation by the rear brake band 21, the gear axles 20 are also held in a fixed position, and the rotation of the turbine shaft 5 is transferred from the gear 9 to the gear wheels 12 and consequently via the gear wheels 17 to the gear wheel 19 transmitted on the output shaft 18 with a reduction that is similar to that of an ordinary gear reduction, whereby the first gear is realized.

Second gear: The front clutch 6 remains engaged and the front brake band 22 is actuated while the rear brake band 21 is released. Thus, the input sun gear 9 is rotated together with the turbine shaft 5 while

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the rear clutch drum 27 _; and consequently the reverse solar. wheel 10, is secured against rotation by the front brake band 22 ο In this state, the rotation of the turbine shaft 5 is transmitted directly to the input sun wheel 9, and the gear wheel 11 is driven by the input sun wheel 9 in a direction (counterclockwise) opposite to the direction of rotation Tried (clockwise) the .lurbinenwelle 5 to rotate. , etc. The planetary gears 11 that rotate · in this direction, the free-running gears 15 try to rotate clockwise via the gears 16th However, since the gearwheel 10, which meshes with the gearwheels 15, is secured against rotation, the gearwheel axles .14 rotate clockwise about the gearwheel 10. This rotational movement allows the input sun gear 9 to rotate and is converted into a rotation of the gearwheel 19, which is arranged on the output shaft 18, wherein the sun gear 9 and the gear 19 are arranged coaxially to one another. ^ are and rotate in the same direction as the turbine shaft 5. Since the number of teeth of the gear 12 has been selected to be greater than the number of teeth of the gear 17, the speed of the intermediate shaft 8 is greater than that of the * output shaft 18. In other words, the output shaft 18 is at a reduced speed or ' Speed or rotated according to a · second gear.

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Third gear: Third gear can be obtained by having both the front and the rear clutch 6 and 7 are engaged. The input sun gear 9 and the reverse sun gear 10 are rotated together, and that entire planetary gear system is rotated as a unit, so that the output shaft 18 is rotated at the speed of the turbine shaft.

Reverse gear: To switch on the reverse gear, the rear clutch 7 and the rear brake "band 21" are actuated. As a result, the carrier 13, and consequently the gear axles H and 20 _; locked against rotation, and the rotation of the turbine shaft 5 is transmitted via the rear clutch 7 to the reversing sun gear 10 and consequently via the gears 15 and 17 to the gear 19, which is mounted on the output shaft 18, so that the output shaft 13 in is rotated in the opposite direction.

Hydraulic actuation system

The arrangement of the hydraulic actuation system according to the invention is schematic in the Pig. 4 to 10 shown. In short, the hydraulic actuation system includes

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a fluid pressure source 100 and a hydraulic actuation circuit 110. The hydraulic actuation circuit 1.10 contains a manually adjustable valve 120, a 1-2 switching device 130, a 2-3 switching device 135, a check valve HO and fluid lines. The Pluiädruckquelle 100 includes an oil pump 101, an oil filter 102, a regulating pressure · M lierventil 105, a check valve 103 'an oil cooler 104 and fluid ^ JLeitungen. The fluid pressure source operates to deliver fluid under pressure to the torque converter, lubricating gears, and the hydraulic actuation circuit.

The manually adjustable valve 120 is connected to an adjusting lever (not shown) which is arranged near the driver's seat and can be adjusted to one of the positions P, R ,. · .Ή N, D, 2- and L. When the manually adjustable valve 120 now assumes the N position, a fluid line 121 is closed and the valve chambers 122 and 123 are, as it is in Pig. 4 is shown, depressurized or emptied. In the D position of the manually adjustable valve 120, the fluid line 121 with the fluid lines' 124,. 125 and 126 as it is in Pig. 5 is shown connected. The fluid line 124 leads directly to a front coupling

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actuation chamber 6a, and the fluid line 125 leads over the 1-2 switching device 130 to the actuation side 22a of an actuation device for the front brake band 22, while the fluid line 126 via the 2-3 switching device 135 and the check valve 140 to an actuation chamber 7a for the rear clutch and to the switch-off side 22b of the actuating device for the front brake band 22 leads. The 1-2 Switching device 130 comprises a 1-2 switching valve 131 and one Solenoid 132. One end (or the right end in the drawing) of the valve 131 abuts against a movable core 133 the solenoid 132 on. When no current is applied to the solenoid 132, the valve 131 is opened by a spring 131 a, which rests against the other or left end of the valve 131 is pressed into its right position, so that the fluid line 125 is in communication with a fluid line 134, whereby fluid on the switch-on or actuation side 22a of the actuation device for the front brake band 22 is given to actuate the front brake band 22. When a stream is on the solenoid 132 is given, the valve 131 is through the movable core 133, which is displaced by the electromagnetic force of the solenoid 132, to its left position brought so that the connection between the fluid lines 125 and 134 interrupted and the fluid line 134 with a

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Pressure outlet opening T34a is communicated to release the - front brake band 22. Similarly, the 2-3 switching device 135 contains a 2-3 switching valve 136 and a solenoid 137. One end (or the right end in the drawing) of the valve 136 rests against a movable core 138 of the solenoid 137. If gegebeii to the solenoid coil 137, no current ^x is, the valve is pushed 136 through a Peder 136a abuts ™ against the other or left end of the valve 136 in its right position so that the Pluidleitung 126 is connected to a Pluidleitung 139 , whereby a kickback ball 141 of the check valve 140 is pressed against the fluid line 128 to block the fluid line 128. As a result, the fluid line 139 is connected to a fluid line 142, so that the actuating chamber 7a for the rear clutch and the switch-off or release side 22b of the actuating device for the front brake band 22 fluid is fed, W whereby the rear clutch 7 is engaged and the front. Brake band 22 is released. When the solenoid 137 is energized, the valve 136 is pushed to the left, so that a connection between the fluid lines 126 and 139 is broken and the fluid line 139 is connected to a pressure outlet port 139a, whereby a pressure relief is effected.

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In the first gear of the driving range position or D position - 1st gear, as shown in Pig »5," both solenoids 132 and 137 are excited, and only the front clutch 6 is due to the fact that the actuating chamber 6a for the front clutch is supplied via the fluid line 124 · fluid is engaged. Accordingly, it is when the transmission or the power transmission system is driven by the machine is, the one-way clutch 23 is engaged, so that the carrier 13 is secured against rotation, whereby the first gear can be switched on. In this Pail, however, no driving force can be transmitted from the output shaft 18 because there is a freewheeling condition.

In the second gear of the driving range position or D position-2nd gear, As shown in Pig.6, the 'fluid line 124 leading to the actuation chamber 6a for the front clutch leads. kept under pressure, and the solenoid 132 for the 1-2 switching valve 131 is switched off with the result that the fluid line 125 is connected to the fluid line 134, whereby the actuation or switch-on side 22a of the actuating device for the front brake band 22 Pluid is fed, so that the front brake band 22 is actuated. In this way, second gear is

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switches. . ·

In third gear in the driving range position or D position-3rd gear, as it is in Pig. 7 is shown, the solenoid 137 is in addition to the "earlier for the 2-3 shift valve 136 is already in the position-D-2nd disconnected Mag- '-d netspule off 132, whereby the fluid line 126 is connected to .the fluid line 139 so that fluid is supplied to the rear clutch operating chamber 7a to engage the rear clutch 7 while the front brake band 22 is released. Thus, 3rd gear is engaged.

When the manually adjustable valve 120 is in the position shown in Fig. 8 position 2 shown is adjusted, the Pluidleitüng 126, which leads to the 2-3 switching device 135 is depressurized, and only the fluid lines 124 and 125 with the ITuiddruckquelle are available 100 in connection. Accordingly, it is independent of the fact that the solenoid 137 for the 2-3 switching valve 136 is off, impossible to engage third gear, during the first and the second gear, depending on whether the solenoid 132 for the 1-2 shift valve I3I is excited or is switched off, can be switched on.

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When the manually adjustable valve 120 is in the Pig. 9 is adjusted, the fluid lines 125 and 126 relieved of pressure, and the pluid lines 124 and 127 are brought into communication with the fluid pressure source 100. This is the actuation chamber 6a for the front. Their clutch and the actuating side 21a of an actuating device for the rear brake band 21 fluid is supplied to engage the front clutch 6 and actuate the rear brake band 21. In this way, first gear can be engaged will. The first gear in this case differs from the first gear in the D position in that: that the rear brake band 21 is actuated in order to transfer the driving force from the output shaft to the machine to enable, whereby the braking force of the machine or the motor can be used.

When the manually adjustable valve 120 is moved to the R position shown in FIG. 10, the fluid lines 124, 125 and 126 are depressurized while the fluid lines 127 and 128 are in communication with the fluid pressure source 100 to be brought. As a result, the actuating chamber 7a of the rear clutch and the actuating side 21a of the actuating device for the rear brake band 21 fluid pull

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leads to engage the rear clutch 7 and the rear brake band 21 to "operate. In this way, the reverse gear switched on for the motor vehicle.

From the above description it should be apparent that.

. the hydraulic actuation system in the present invention. ^ dung is characterized in that it has a new hydraulic switching arrangement and a biasing device in the form of springs 131a and 136a to switch the 1-2 switching valve 131 and the 2-3 switching valve 136 to the upper switching position when the corresponding solenoid 132 or 137 is switched off bias or switch. The switching arrangement of the hydraulic actuation system is designed in such a way that in the D positions of the manually adjustable valve 120 the actuation chamber 6a of the front clutch for the front clutch 6 via the fluid line 124, the actuation side 22a ™ of the actuation device for the front brake band 22 via the fluid line 125 and the 1-2 switchover device 130 or the rear actuation chamber 7ad the rear clutch for the rear clutch 7 and the switch-off side 22b of the actuation device for the front brake band 22 via the fluid line 126 and the 2-3 ^ switching device. 135 fluid pressure from the fluid pressure source 100 is fed. In the 2 position

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of the manually adjustable valve 120, the fluid line 126, which leads to the 2-3 switching device 135, is depressurized, and the fluid lines 124 and 125 are in connection with the fluid pressure source 100, while in the L-position of the manually adjustable valve 120 the The fluid line 125 leading to the 1-2 switching device 130 continues to be depressurized, while the fluid line 124, which leads to the actuation chamber 6a of the front clutch for the front clutch 6, and the fluid line 127, which leads to the actuation side 21a of the actuation device for the rear brake band 21 leads, are in communication with the fluid pressure source 100. Due to the above circuit, even if the power supplied to the shift signal control system from the electrical voltage source fails, the manually adjustable valve 120 can be moved to the L position to engage the first gear, and the 2 position to engage the second Gear and moved to D position to engage third gear. Such a hydraulic shift arrangement is extremely advantageous in that if faults occur in the shift signal control system that controls the supply of the electrical signals to the solenoid coils, or if the driver wants a sporty driving style with more gear changes compared to the gear changes that occur due to the

009840/1196

Set in the 'electrical' control system from the start Changeover points are executed / the! Driver presses the switch, the connects the voltage source with the switching signal control system, can switch off in order to interrupt the supply of energy to the switching signal control system, whereby the switching signal control system is switched off, and he can then set the gearshift lever in one of the positions L, 2 or D to allow the driver to switch on the desired transmission ratio. In other words, the switch can be turned on and off to if desired, either a ferry service under fully automatic Select switching control or a driving mode with manual switching *

There is a second feature of the present invention in the fact that in the D-position I.Gang a freewheeling operation is made possible, whereby a protection against any erroneously given shift signal for first gear that is obtained by the shift signal control system in the high-speed running range could be delivered.

■. A third feature of the present invention is the fact that the solenoids 132 and 137 are during the motor vehicle drives in third gear with the switched off .. '■' ■■■ "

009840/1196

stand ". It is therefore unnecessary to use any electrical Power consumption caused by the operation of the solenoids, nor any undesirable heat generation, which leads to a temperature rise due to the current supplied to the magnet coils.

The fluid pressure supplied to the actuators is controlled by the pressure regulating valve 105. The pressure regulating valve 105 comprises a valve slide 105a which bears against a spring 106 at one or the upper end thereof. In the R position of the manually adjustable valve 120, fluid pressure is supplied via a fluid line 128 to a valve chamber 107 which surrounds the upper part of the valve slide 105a. The lower part of the valve spool 105 is a type of spaced apart valve chambers 108 and 109 W environmentally, wherein the chamber is supplied 108 from the oil pump 101 and the chamber 109 via a fluid line 134 b fluid pressure. In the D or * 2 position of the manually adjustable valve 120, the fluid line 125, which leads to the 1-2 changeover device 130, is supplied with fluid pressure. Then, when the 1-2 changeover solenoid 132 is switched off, the valve I3I is moved into the upper switching position, so that a connection is established between the fluid lines 125 and 134, see above

009840/1196

that the chamber 109 is supplied with fluid pressure via the fluid line 134b will. On the other hand, the chamber 107 is in the gear positions with the exception of the reverse position, pressure-relieved .. Thus, the pressure regulating valve 105 provides a constant / low fluid pressure Ρ, ^ generated; by the spring pressure of the .Spring 106 and the fluid pressures in chambers 108 and 109 are determined will.ι '· * "-"

When the manually adjustable valve 120 is in the

tr

D or 2 position and the 1-2 shift valve 13 "1 in the lower shift position · (corresponding to first gear). the actuation of the solenoid 132 is misaligned, or if the manually adjustable valve 120 is in the! position, is the chamber 109 of the pressure regulating valve 105 pressure 'relieved and through the Druckregulie rventil "105 a constant fluid pressure Pt is generated, which by the spring pressure of the Spring 106 and the fluid pressure in the chamber 108 is determined. In the R position of the manually adjustable valve 120 is a fluid pressure is exerted on the chamber 107 of the pressure regulating valve 105 via the fluid line 128. Accordingly, will through the pressure regulating valve 105 a constant high fluid, pressure Pjjj generated by the spring pressure of the spring 106 and the fluid pressures in the chambers 107 and 108 is determined.

0 09840/1196

From the above description it can be seen that the the fluid line 134 leading away from the 1-2 changeover device 130 is connected to the pressure reducing chamber 109 of the pressure regulating valve 105, so that the through the pressure regulating valve 105 fluid pressure generated is decreased when the 1-2 switching valve • 131 is switched to the high gear position will.

In Pig. 11 is the change in the fluid pressure or the line pressure Pt generated by the pressure regulating valve 105 depending on the rotational speed of the output shaft 18 and hence the vehicle speed _; shown. As can be seen from Fig. 11, a pressure drop occurs from the constant fluid pressure Pt to the fixed low fluid pressure Pjt in the 2 or D position of the manual valve 120 when the rotational speed of the output shaft 18, and hence the vehicle speed , is increased and the gear ratio is switched from first to second gear. In general, the 1-2 switchover point and the 2-1 switchover point are variable depending on the signal that is responsive to the engine torque. Thus, the point at which the pressure is decreased from the constant fluid pressure P _x to the constant low fluid pressure Pj ^ changes / in ab-

009840/1196

SCO 194.1

depending on the one responding to the machine torque Signal.

As a result, the control pressure characteristics described in detail above can be supplied to the actuation chambers for the clutches and the brake bands - a line pressure which the torque multiplier effect- " effect of the torque converter taken into account, so that a sufficiently large engagement or coupling force in the lower Speed or gear range can be maintained, while a constant low line pressure is supplied to the actuation chambers in the high speed range can be used to avoid power losses, such as in the oil pump and avoid other elements as the torque multiplier Effect of the torque converter in the high speed range is lost due to the fact that the torque converter essentially acts as a hydraulic clutch.

According to the present invention, the switching valve acts which is provided for the purpose of switching control, continues as a means to increase the positive pressure control effect of the Pressure regulating valve 105 to change. This makes it unnecessary Valve devices (such as a so-called compensation

009840/1196

20Q194

- 52 -

sation valve or throttle valve relay), as it is "in the conventional automatic gearboxes were provided to change the fluid pressure control action of the pressure regulating valve, thereby reducing the structure of the hydraulic Circuit is considerably simplified.

Although an arrangement was described above in the description in which the positive line 134, which is from the 1-2 Switching device 130 to the actuating side 22a of the actuating device for the front brake band 22 leads, connected to the pressure reducing chamber 109 of the pressure regulating valve 105 is to decrease the line pressure simultaneously with a shift to second gear, however, an arrangement may also be used be taken in such a way that the eluid line 139> that from the 2-3 changeover device 135 to the actuation chamber 7a for the rear clutch 7 is connected to the pressure reducing chamber 109 of the pressure regulating valve 105 to reduce the line pressure at the same time as shifting to third gear.

The 1-2 changeover device 130 and the 2-3 changeover device 135 are operated so that they change the pressure regulating effect of the pressure regulating valve 105 and the automatic

009840/1196

_ 33 - · '

Perform a matic switching process, which is achieved by optionally switching the solenoids 132 and 137 on and off will. In the following, the Schaltsighalsteuersystein will be described, which serves to the solenoids 132 and 137 Supply or switch off electricity.

Switching signal control system

Like from Pig. 12 can be seen includes the switching signal control system a unit 200 for setting the position of the throttle valve, a unit 201 for setting the rotation number of the output shaft, an arithmetic circuit 202 for the 1-2 Switching point and a computing circuit 203 for the 2-3 switching point.

. ■■■;. ■ '. ■■ ■■■■.

The switching arrangement 200 for setting the position the throttle valve comprises a variable resistor 310, the tap arm of which is connected to a throttle via a cam lever 312

dal 311 is connected, as it is in Pig. 17 is shown so that an electrical signal © is emitted on a line 210, which depends on the position of the accelerator pedal 311 is changeable.

00-9840 / 1196

2001241

The switching arrangement 201 for adjusting the speed of the output shaft comprises a device 320 for adjusting the speed of the output shaft and a further treatment circuit 325 for the speed signal from the output shaft. Like from Pig. 18 it can be seen, "the control device 320 for adjusting the speed of the output shaft consists of a toothed disk 321 made of a magnetic one
Material that is "attached to the output shaft 18", and a tachometer 322, which is at a close distance in front of the toothed disc 321 in the diametrical direction of this disc
is arranged. The tachometer 322 includes a permanent magnet 323 and a coil 324 that is wound around the permanent magnet 322. The permanent magnet 323 and the
Coils 324 are placed in a suitable housing made of a non-magnetic material, and the housing is on
the gear housing .befestigt so that one end of the permanent magnet 323 is arranged in the immediate vicinity of the outer circumference of the toothed disc 321. When a tooth part of the toothed disk 321 when this toothed disk rotates by the magnetic field of the permanent magnet 323
running, a change in the leakage flux of the permanent
Magnet 323 is generated so that an electromotive force is generated in the coil 323. The electromotive force or

009840/1196

Voltage occurs at terminals 70, which with the wide -be- · action circuit 325 for the revolution count signal from the output shaft are connected. The processing circuit 325 '. for the speed signal from the output shaft consists of one ■ Amplifier circuit, an amplitude limiter and a .Frequency-DC voltage conversion circuit. That on one Line 211 occurring input voltage signal is through the amplifier circuit amplifies, and the amplitude limiter limits the amplitude of the amplified signal to one fixed height. The frequency-DC conversion circuit converts the alternating voltage into a direct voltage, which is then output via a line 212. The electric Signal N, the waveform of which is stabilized in this way has been and which represents the speed of 'the' output shaft 18 is, together with the electrical signal Q, the reproduces the position of the throttle valve, fed to the computing circuits for the switchover points.

The arithmetic circuit 202 for "the 1-2 changeover point comprises a circuit 326 for modifying the speed signal from the "output shaft., a Wähischaltung '327 And * a switch-' setpoint circuit 328. The electrical signal F that represents the speed of the output shaft, is transmitted via a line

4 0/11 9 6

device 214 given to the selection circuit 327. At the same time will this electrical signal IT via line 212 of circuit 326 for modifying the speed signal from the output shaft so that the signal is fed to the selector circuit 327 via a line 216 in a suitably modulated form. will. An output line 217, which leads away from the selection circuit 327, is optionally with a switch relay of the input lines 214 and 216 can be connected. The selection circuit 327 is controlled by a voltage set by a feedback circuit 219 is fed back to one with the output side of the switching point circuit

328 connected output line 218 is connected.

The switching point circuit 328 has a structure as shown in Pig. 20 is shown. The line 217 leading to The signal N representing the speed of the output shaft is supplied, and the line 213, which is used to supply the The signal 0 representing the position of the throttle valve is connected to one end of the potentimeter 330 and 329, respectively. The potentiometers 329 and 330 are grounded at their other end. Grinding arms 331 and 332 of the respective potentiometer

329 and 330 are connected to a differential amplifier 333, the output of which appears on line 218.

Q09840 / 1196

2001341

The calculation of the switchover point is understood to mean the calculation or position of the inequality O - A (N) ^ Ö, where A means a constant "which is determined from a switchover diagram as shown in FIG. 25". First, the positions of the sliding arms 331 and 332 are determined in such a way that the output voltages which appear in accordance with the application of the signals 0 and N to the potentiometers 329 "and 330 have the relationship θ = A (H) When these "two output voltages are applied to the differential amplifier 333, the difference existing between these output voltages, ie the expression 0-A (IT)," is calculated or determined. If the result is positive, the difference is amplified. so that this as a fixed tension on the. Line 218 appears, while when the result is negative there is no output voltage on line 218. Thus, the calculation of 0 ^ A (N) can be carried out by suitable selection of the settings d of the potentiometers as well as the input terminals of the potentiometers. The output from circuit 328 appears as a voltage on line 218 and is used to actuate 1-2 changeover solenoid 132.

The 2-3 toggle point circuit 20 ^ -contains one

0 09840/1196

first changeover point calculation circuit 220 and a second changeover point calculation circuit 221. The first changeover point calculation circuit 220 is similar in structure to the 1-2 changeover point calculation circuit 202 and consists of a circuit 326 ^f for modifying the speed signal from the output shaft, a selector circuit 327 'and a changeover point circuit 328 ¹ . In the toggle point circuit 328 ', the output of which appears on a line 218, the relationship 0 ^ C (N) (O ^> C (N)) is calculated. The second changeover point calculation circuit 221 consists of a changeover point circuit 222, a gradient setting circuit 223 and a bistable storage circuit 224. In detail, the second changeover point calculation circuit 222 consists of a circuit 334 that can be actuated in accordance with a setting of the throttle valve position and one that can be actuated in accordance with a setting of the speed of the output shaft Circuit 339 and an AND circuit 340 together.

The setting circuits 334 and 339 determine whether or not an output signal is given depending on the magnitudes of the input voltages 0 and N in relation to predetermined values. For explanation see Pig. Figure 21 shows an embodiment of the adjustment actuator latch 334 for

009840/1196

2001341

the throttle valve position is shown, which is used to calculate the variable θ S,% 2. serves. The voltage that indicates the throttle valve position or opening Ö is fed via line 210 to a potentiometer 335 * whose grinding arm.336 is connected to a reference voltage device 337, such as a Zener diode • which conducts when it is on a higher voltage than the reference voltage is brought. The output of the sawn% zugsspannungseinrichtung 337 is connected to an amplifier 538 whose output appears on line 226th The wiper arm 336 is adjusted to an appropriate position _{to appropriately divide the voltage Q 1 applied} to the potentiometer 335. When ah the wiper arm 336 voltage applied higher than the reference voltage, is set by the reference voltage device 337, issued wird'durch the reference voltage device 337, a signal to the amplifier 338 and by the amplifier 338 is a comparatively ■ Λ boosted voltage generated. Conversely, when the reference voltage is higher than the voltage on the wiper arm 336, no voltage appears at the output of the reference voltage device 337. The amplifier 33 ⁸ may include a phase inversion means "so that a reverse to the above raw output can be obtained. The setting circuit 339 for the speed of the Atisgangswelle has exactly the same structure as

009840/1196

the setting circuit 334 for the throttle position, and the signal H "is instead of the signal O on the in Pig. 21 shown line 210 given. The two setting circuits 334 and 339 described above are thus in the switching point operating circuit 222 switched that the signal 0, which indicates the throttle valve position, via line 210 on the setting operation circuit 334 and an output from the Circuit 334 is passed to AND circuit 340 via line 226 will. On the other hand, the signal N, which represents the speed of the output shaft, via the line 212 to the Set actuation circuit 339 and an output from circuit 339 to AND circuit 340 through line 227.

The AND circuit 340 consists of a conventional UUD circuit. Thus occurs when at the same time from the setting actuation circuit .334 for the throttle valve position at 0 J>

an output signal and an output signal is outputted from the setting operation circuit 339 for the rotational speed of the output shaft at NV 1800 rpm, an output voltage signal on a line. This signal is used as an upshift signal to effect a shift from second to third gear.

009840/1196

The gradient adjustment operation circuit 223 includes an adjustment operation circuit 341 for the throttle pitch, a speed setting operation circuit 342 the .output shaft, the "acceleration determining Circuit 343, a setting confirmation circuit 346 for the . Acceleration and a TJND-Xreis 349.. .

The setting operation circuit 341 for the throttle valve position has a structure similar to that of the operation circuit 334 described in detail above, so that on. an output voltage occurs on a line 229 when the signal 0, which indicates the throttle valve position, fulfills the condition Q ^ - - -h-. The output shaft speed setting control circuit 342 is similar in structure to the control circuit 339 except that a phase reversing circuit is built into an amplifier which is placed after a voltage reference so that an output signal appears on a line 230 when the signal N, which indicates the speed of the output shaft, fulfills the condition N ^ / 1,600 rpm. The acceleration detecting circuit 343 consists of a low-pass filter 344 and a differentiating circuit 345 as shown in Pig. 22 is shown. The line 212 to the filter

009840/1196

The signal N given to circuit 344 is corrected in its waveform by the filter circuit 344 in that the high frequency components of the signal are filtered out, and the signal is then differentiated in the differentiating circuit 345; Determine acceleration ^ of the vehicle. The signal indicating the acceleration is pulled through a line 231 of the setting actuation circuit 346 for the acceleration. leads. As shown in Fig. 23, the adjustment operation circuit 346 for acceleration is composed of an adjustment operation circuit 347 and a delay circuit 348. The adjustment operation circuit 347 is composed of a potentiometer, a voltage reference device and an amplifier, and thus has a structure similar to those described above Circuits of this type on. The actuation circuit 347 outputs an output signal to the delay circuit 348 when the condition oc <"0.05g (where g means acceleration due to gravity) is satisfied. The delay circuit 348, which receives the output signal from the setting actuation circuit 347, outputs an output voltage only if the signal lasts longer than a second on a line 232. Thus, the combination of the adjust actuation circuit 347 and the delay circuit 348 of FIG

009840/1196

. - "2001841

art that an output signal occurs on the line 232 only if the state <- <<0.05g lasts longer than one second.

On a line 233 from the UUD circle 349 is a

Output voltage delivered when the signal O

■ 1 R '·. I.

^ from the setting actuation circuit 341 for the Dros- ™

See valve position, the signal N- = C 1,600 rpm from the setting control circuit 342 for the speed of the output shaft and the signal from the setting operation circuit 346 for acceleration, what then appears if during at least the state ■ * <■! for one second. 0.05g was present, appear. This output voltage signal is called a down switch signal to switch from the third to the two-tone Gear, and as a signal to shift the 2-3 upshift point (Line) related to the "high-speed side."

The output signal from the gradient setting actuation circuit 223 and the output signal from the switching point actuation circuit 222 are applied to the bistable memory circuit 224 via the respective lines 233 and 228.

009840/1196

_ 44 -

The "bistable memory circuit 224 has the method described in Pig. 24 structure shown. The lines 228 and 233 are with connected to the input terminals of a bistable multivibrator 349, so that the bistable multivibrator 349 when e.g. the line 233 a signal voltage occurs, immediately in one of the stable states is switched and its output, which occurs on a line 234, is amplified by an amplifier 350 will. On the other hand, when an input signal appears on line 228, the bistable multivibrator 349 is in the switched to another stable state and its output is amplified by the amplifier, but is amplified by the amplifier 350 no output voltage delivered. Even if there is an input signal for example on the line 233 and then disappears, the bistable multivibrator 349 remains in its stable state in which an output signal continues to exist line 234 is discharged.

The output of the second switching point actuation circuit 221 described in detail above and the output of the first switching point actuation circuit 220 are connected to an OR circuit 225, which is described in detail below will be described to the 2-3 changeover solenoid 137 depending on the output signals from these circuits to control.

009840/1196

In reality, the OR circle 225 consists of a circle called the NOR circle (NOT-OR circle). The output signal from the switching point actuation circuit 328 'and the output signal from the bistable storage circuit 224 are sent to the OR circuit 225 via the corresponding. the lines 218 'and 234. If one of these two signals occurs, an output signal appears on a line 235, which is sent to the magnetic coil 1.37. "

The switching control process of the individual circuits of the switching signal control system will be described in detail below will. . :

Shift control process

The relationship between the gear ratio of the

The transmission and the operating state of the solenoid coils have been described with reference to the hydraulic actuation circuit , and this relationship can be briefly described in accordance with the following list

are summarized: ·

00984071196

- 46 -

Table I.

Solenoid 132 Solenoid 137 first course excited I.
excited second gear switched off excited third gear switched off switched off

(1) 1-2 shift control

The magnitude of the signal O of the throttle valve position becomes smaller than A (N) or (ö) <CA (N), when the parity of the vehicle is in the range (in which the speed of the output shaft is greater) on the right-hand side of the curve θ = ON in the switching diagram in Pig. 25 moves. At this point, the output of the changeover point actuation circuit 328 is turned off and the solenoid 132 is de-energized, causing a shift from first to second gear to be performed. At the same time, the feedback circuit 219, which connects the line 218 to the selector circuit 327, is switched off, since no output signal is emitted on the line 218 by the switching point actuation circuit 328. This causes lines 216

009840/1198

and 217 are now connected to the selector circuit 327 instead of the previous connection in which the lines 214 and 217 ″ were connected to the selector circuit 327 when the first gear was engaged. wave modulated, and the modulated signal is applied to the switching point actuation circuit 328. The relationship between θ and IT is now given by the curve O = A ¹ H as shown in Figure 25, so that a 2-1 switching takes place along this curve. This curve represents a 2-1 "downshift line. Therefore, when the transmission has been switched to second gear, the signal Έ, which represents the speed of the output shaft, is modulated by the circuit 326, and a shift from first to second gear is carried out along this line. That is, the voltage signal N indicative of the rotational speed of the output shaft is variable in accordance with the engagement of the first and second gears, and such a variable signal is given to the shift point actuation circuit, so that a hysteresis between the 1-2 upshift point and the 2-1 downshift point is obtained through which a stable 'switching operation is ensured. With the help of such a circuit, the calculation of the' upshift '' and - the

1 -

0 09840/1196

Downshift from the same shift point actuation circuit are executed.

Such a .1-2 changeover control process is derived from the comparison between the control circuit in the Pig. 13 shown Position for first gear and the control circuit in the Pig. 14 position shown for the second gear clear. In the pig. 13 and 14 are lines on which no signal voltage appears as solid lines and those lines on which a signal voltage is present are shown by dashed lines.

(2) 2 - 3 switching control

The one by the first switching point calculating circuit Switching control operation carried out in 220 is carried out in the same manner as described above. When the vehicle speed increases to such an extent that the state variables of the vehicle move into the area on the right Side of the curve θ = CN in that in Pig. 25, the output signal ah of the switching point operating circuit becomes 328 'is switched off, and for the Pail that on the output line 234 of the second

009840/1196

'- 49 -

switching point calculation circuit 221 is no signal voltage present, the solenoid 137 is switched off, so that a changeover from the second to the third gear takes place. This operating state is shown in Pig. 15. At this time, no output is output from the switching point calculating circuit 328 ·, and no signal is supplied to the feedback circuit 219 'connected to the output line 218 ·. As a result, the lines 216 'and 217' are now ^{connected to this selector circuit 327 'instead of the lines 214 1} and 217' which were connected to the selector circuit 327 'while the second gear was switched on. The signal N is modulated by the change circuit 326 '• for the speed of the output shaft, and the modulated signal is given to the shift point operating circuit 328 ^f. Consequently, when the transmission has been shifted to third gear, the shift point becomes despite the fact that the Calculation is performed by the same toggle point actuation formwork 328 * as that used in Pig. 25 shown curve β ■. «O ¹ N shifted. I. E. there occurs a hysteresis between the 2-3 upshift line T © »CN) and the 3-2 downshift line (0 a O ¹ N)

009840/1198

Switching control process is.

Second, the switching control process of the second switching point calculating circuit 221 includes the 2-3 switching control process by the gradient operating circuit 223, the switching point operating circuit 222 and the bistable memory circuit 224.

If the state variables for the driving state of the vehicle are shifted into the area a in FIG. 25 (in which β> ^ jM and N- ^ 1,600 rpm) and at the same time the conditions for the setting actuation circuit 346 for the acceleration are fulfilled, ie that the condition that the acceleration is c * "^ Cp, 05g is fulfilled for at least one second, an output signal is emitted by the AND circuit 349 and then by the bistable memory circuit 224 225 to energize the OR circuit a signal to the line 235 from which serves the solenoid 137th (or if the vehicle travels to the time at which this signal occurs in third gear, eo is a downshift to the second speed instead of, 'while, when the vehicle is in; another gear, there is no change in the gear ratio) * Pig, 16 shows the state that is *

009840/119 *

occurs after a downshift from third gear the second course took place. Ea the electrical signal the .Magnetspule 137 via the bistable memory circuit is supplied, the solenoid 137 will continue to operate energized by memory circuit 224- when the output signal- • from AND gate 349 disappears. This electrical signal is then deleted when the signal from the um- '" switching point actuation circuit 222 is given to the bistable memory circuit 224, which is the case when both Conditions O I ^% 5 and H Z> - 1,800 rpm are met, and the respective signals are from the setting operation circuit 334 for the throttle position and the adjusting operation circuit 339 for the rotational speed of the output shaft and this causes the AND circuit 340 to provide an output signal aimed at the bistable Memory circuit 224 is given. The bistable memory (| circuit 224 becomes in the other stable state even then held when the signal from the switching point actuation circuit 222 disappears. Thus, 'if the state variables for the driving state of the vehicle in the area.b in

Fig. 25 can be moved (in which ö Ξ> ° -4- * ϊ and NJ ^ 1,800 rpm is) the signal to the gradient actuation circuit 223 switched off, and if there is no signal from the first

009840/1196

point calculation circuit 220 is present, an upshift occurs into third gear instead.

Pig. 26 is a graph showing the operating characteristics of a motor vehicle are shown with a torque converter transmission

ψ is equipped. The total road resistance R is given for the pail that the vehicle travels at a steady speed by the sum of the rolling resistance, the air resistance and the resistance which is caused by an incline. The relationship between the rotational speed N of the output shaft and the pulling force is in Pig. 26, the gradient sin χ serving as a parameter. Like from Pig. 26, the total road resistance R increases as the gradient sin χ increases. On the other hand, the driving force H which

^ is transmitted by the engine, through the action of the Motor and the mode of operation of the transmission are determined. In Pig. 26 is also the relationship between the speed N of Output shaft and the tractive force shown in third gear, with the throttle valve position 0 selected as a parameter became. The difference between the driving force H of the engine and the total running resistance R represents the acceleration resistance Rh, which during the acceleration of the vehicle

009840/1196

witness occurs. The acceleration resistance Rh is generally given by the following equation:

Rh = Wgg- (1)

where W is the weight of the vehicle in kg, "We the weight in kg corresponding to the inertia of the rotating parts of the drive mechanism of the vehicle J, <* the acceleration of the vehicle in m / sec and g the acceleration due to gravity in m / sec. Thus the acceleration resistance Rh can be obtained from the above equation given the value of the acceleration Oi , the main data of the vehicle, the road conditions and other factors, since for the acceleration resistance Rh = H - R gi ^ t ^, Rh is essentially a puncture the throttle position 0 _; the speed N of the output shaft and the gradient sin x. That is, Rh can be expressed * by Rh - Ρ (θ ;, N, sin x). From this it follows that the gradient sin χ can be calculated, if the throttle position Θ, the speed N of the output shaft and the acceleration (from which Rh can be calculated according to the above equation) obtained by differentiating the speed Κ of the output shaft According to the embodiment of the present invention described above, it is determined who the, ■ '.' ■■

009840/1196

The present invention employs the above relationship in its simplest form so that the gradient which decreases with an increase in the rotational speed of the output shaft is detected by the gradientea actuating circuit 223. For the conditions that the throttle valve opening ö ^> ^ JT "t is the speed of the output shaft N ^ 1,600 rpm and the acceleration of the vehicle ^ ^ .0.05 g in third gear, the Gradientea actuating circuit 223 with increasing The speed N of the output shaft detects a progressively low or smaller gradient as shown in Fig. 26. Thus, the gradient actuation circuit 223 sets a gradient of sin χ ^ 0.05 in the vicinity of the speed N »1,600 rpm of the output shaft and a gradient of sin x ^ 0.10 in the vicinity of the speed H »1,000 rpm of the output shaft

> 1 8 - - _o - ~ ~ - .. "-. -w ~ w ~ "w"" _e -i-jS and

N jg = g 1,600 rpm in third gear when the acceleration oC is equal to Oi «0.05 g. Such a gradient is determined when the vehicle is driving on an uphill incline or in a mountainous area, and a signal in response to this is used as a changeover signal for switching to a lower gear or as a signal for the switching line on the high-geo windy side different

009840/1196

■ "; ■ ■:... ■ ■ ■■■ ■ - 55 ~ ■ ■■ -;

ben so that the vehicle with the "most suitable gear setting." can drive. The gradient .sin χ is determined by the acceleration c <, and although these two just described embodiment according to the settings of the throttle valve position and the speed of the output shaft to one is set to a fixed value, it can just as well be used as a variable be designed * which depend on the throttle position and the speed of the output shaft changes when a higher degree of control is required. (This will be the result allows you to adjust the potentiometer or the reference voltage device in the Pig. 20 actuation circuit shown can change depending on the throttle position and the vehicle speed '). If that If the vehicle is traveling in second gear, the drive force H of the engine is greater than in third gear due to the performance characteristics of the transmission, and it becomes a steeper gradient established. · ■

As described above, the 2-5 changeover mode is used executed by the two switching point calculation circuits 220 and 221, their output lines 218 »and 234 via the OR circuit 225 with the magnet ^ coil 137 are connected. The relationship between the gear setting and the ones seen on lines 218 »and 234

009840/1196 '

- 56 -

Signals is given in the following table:

Table 2

Gear position Signal on the
Line 218 ' It
Signal on the
Line 234 second gear a a · second gear the end a second gear a the end third gear from ■ the end

If no signal occurs on line 234, that is, if the vehicle is traveling on a flat road and the acceleration force available to the vehicle has sufficient leeway for the present throttle valve position 0 and the speed of the output shaft, then the 2-3 switchover occurs the lines 0 = CN and O = C ¹ N in FIG. This switching scheme corresponds to the switching scheme previously used in conventional, automatically shifting converter transmissions. However, if the vehicle begins to travel up an incline and the vehicle's acceleration force leeway is lost, the signal appearing on line 234 will cause a downshift from third gear

QQ98A0 / 1196

carried out to second gear if the vehicle was in third gear at that time. In the other cases, switching does not occur. Thus, the bold line χ in Fig. 25, which extends from the line θ = CIi to the point Q = · ° -4- ^ at N = · 1,800. RPM, represents the 2-3 shift line. When the running state quantities of the vehicle shift to the right side of the 2-3 upshift line, a 2-3 upshift is carried out, and under these circumstances, the signals disappear on lines 218 · and 234. A 3-2 downshift can occur if you see the driving state variables of the vehicle shift to the area on the left-hand side of the line 0 = C ¹ N, or if there is an output from the gradient actuation circuit signal is emitted. ■■■ "■ ._

From the above description it can be seen that the automatic switching control system according to the invention is characterized in that a 2-3 changeover (a changeover between the lower gear and the upper gear in the case of an automatic transmission with two forward gears) occurs during a trip a flat road on the two switching lines shown in FIG. 25 ■ CN and Q = C ¹ Ji and when driving in a mountainous area on another switchover. line is carried out. When driving on a flat road

009840/1196 ^;

such as when driving in town or driving on a motorway, it is ideal if the switchover is carried out in a low speed range in which the accelerator pedal only needs to be depressed a little so that the switchover point progressively approaches a Hochgeschwihdigkeitsseite moved when the accelerator pedal is depressed further. Let it now be assumed that the vehicle traveling in a relatively low speed range of third gear with this shift pattern enters a mountainous area and begins to travel up an incline. In such a case, since the running resistance due to the gradient is increased and the accelerating force is decreased, the accelerator pedal must be depressed to effect a downshift to the second gear, thereby accelerating the vehicle. If, however, the force exerted on the accelerator pedal is reduced again afterwards, an upshift to third gear occurs again immediately. It is therefore impossible to achieve the desired driving condition by depressing the accelerator pedal differently. Furthermore, it is necessary to use the engine braking force on an abrupt route or a curve in a mountainous area. In the Umschaltachema that is intended for the ride on a flat road, verifiable results from an on HE

009040/1191

the force exerted on the accelerator pedal immediately .A downshift to the gear ratio of third gear so that the engine brake machine essentially cannot be exploited. Furthermore, it is necessary make a downshift if after the delay by the braking force of the engine in the above described Way should be accelerated again. From this it is seen that when driving in a mountainous area using such an ideal switching scheme for driving the operation on a level road is influenced by the gear position and that it is impossible to achieve the desired driving conditions to be achieved by depressing the accelerator pedal differently. These Kachteile are thereby eliminates the second gear range in the shift pattern to the relatively high speed side is extended towards the end. It was with the previously known

automatic converter transmissions are generally used for this Disadvantages as far as possible by abandoning the switching scheme, as selected for driving on a flat road. Different from the earlier ones The disadvantages that occur with automatically shifting converter transmissions are eliminated by the present invention. the a switching scheme for driving in a mountainous area

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is provided separately from an ideal switching scheme for driving on a level road, this switching scheme for driving in a mountainous area being achieved by expanding the range for the second gear to the side of a relatively high speed, and ^ _% these two switching schemes can be switched over automatically by an actuation circuit which serves to "determine a gradient. This arrangement allows a switchover point suitable for all driving conditions or driving states to be automatically obtained, and thus a technically advanced gearbox compared to the previously known automatically switching converter transmissions automatic switching can be made by this arrangement.

Although in the above-described embodiment Ie ™ only a setting actuation circuit for the acceleration was used as the gradient detection device, various other gradient detection devices which detect a plane in the same way can of course also be used instead of the setting actuation circuit for the acceleration. Furthermore, in the present invention, although in the exemplary embodiment described above, the signal for changing the switchover scheme is a signal

0098A0 / 1196

was used, which corresponded to the result of the determination of a gradient, the switching scheme change signal in no way limited to such a gradient signal. The invention also includes the Pail, "in which a responsive to the engine torque signal, and means responsive to the vehicle speed signal instead of solely a gradient signal are used to change the switching scheme, so 'ä that the switching scheme depending on the Pährbedingungen in city traffic can be changed appropriately.

009840/1196

Claims (4)

■ Patent pending 1. Automatic transmission system for a vehicle with a gear change transmission and with frictional engagement devices to the gears in the Gear change transmission optionally engaging and featured with an automatic shift control system by a hydraulic actuation circuit (110) with a switching valve (120, 131 »136) for distributing the pressure fluid to the devices acting by frictional engagement (6, 7 »21, 22) for controlling the same, by means (200) for generating a responsive to the engine torque Signal (0), by means (201) for generating a signal responsive to the vehicle speed (N), by a first switching point calculation circuit (220) for calculating one of these two signals or for calculation of the ratio between these two signals, by a second switching point calculating circuit (221), the one Gradient detection circuit (223) has and by a responsive to a gradient. Signal is controlled, and by a circuit (225) for providing an electrical output signal when one of the output signals of these two Beschnungs circuits (220, 221) for actuation 009840/1 of the switching valve. . ■ 2. Apparatus according to claim 1, characterized in that g e k e η η ζ e i c h η e t that the switching valve is a manually adjustable Range switchover adjustment valve (120) and a switching valve (131, 136) to adjust the pressure fluid to the frictional engagement effective devices to control these ^ devices to distribute. 3. Apparatus according to claim; t or 2, characterized in that the first conversion calculation circuit (220) generates a signal when the ratio between the signal responsive to the engine torque and the signal responsive to the vehicle speed meet a predetermined condition met that the in the second "switching point calculating circuit (221) contained gradient detection - ^ M development circuit (223) generates a signal when the signal responsive to the engine torque, the signal responsive to the vehicle speed and the responsive to the change amount of the vehicle speed Signal meet predetermined conditions that an operating circuit (222) is provided for generating a signal when the signal responsive to the machine torque ("O) and that to the 0 09840/1196 Vehicle speed responsive signal (N) other predetermined Meet conditions, and that a bistable memory circuit (224) for the continuous generation of an output signal corresponding to the occurrence of an input signal at one of the input terminals and for permanent suppression an output signal is provided when an input signal occurs at the other input terminal, so that from this bistable memory circuit upon occurrence of the output signal from the gradient detection circuit (223) an output signal can be continuously emitted at one of the input terminals of the bistable memory circuit (224) and the output of this output signal from the bistable memory circuit (224) is continuously prevented when on the output signal from this operating circuit (222) occurred at the other terminal of this bistable memory circuit is, and that an OR circuit (225) is provided which emits an output signal when one of the output signals from the first or second switching point calculation circuit '(220, 221) to this OR circuit, whereby the Switching valve (136) can be actuated. 4. Device according to one of the preceding claims and with control devices that are operationally with the 0098AO / 1196 '■ - - 65 - frictionally acting devices for actuating these devices are connected and with an automatic shift control system, characterized in that the manually adjustable range switching adjustment valve (120) has a first position for setting a relatively large transmission ratio in the forward direction and a second position for setting a relatively low drive -Transmission ratio in the forward direction, that a switching valve (136) is provided in a connecting line (126) between the range switching adjustment valve (120) and the frictionally acting devices (7, 22) to operate these devices acting by frictional engagement that a biasing device (136a) is provided which bears against one end of the switching valve in order to bias this switching valve in a direction towards the high drive transmission ratio in the forward direction, that an electromagneti Sch actuatable device, (137i. 138 is provided), which abuts against the other end of the switching valve for urging the switching valve in the other direction, so that the low drive speed ratio is obtained in the forward direction., Weim the electromagnetically operable device is fed by a Storm, that switching signal control devices (202) .009840 / $ 119 are seen, the supply and the interruption of the electromagnetically operated device supplied current determined depending on the driving conditions of the vehicle, so that the switching valve is shifted in the corresponding direction and that a switch (95) is provided, through which an electrical voltage source (500) optionally with the switching signal control device (501) can be connected, so that this switching signal control device (202) is in the closed Position of the switch in the first position of the manually operable switching range adjustment valve (120) Shift valve (136) actuated so that both the high and low drive gear ratios are in the forward direction is adjustable, while this switching signal control device (501) is in the open position of the switch (95) Can not exercise control function, so that due to the device biasing the switching valve in one direction only the high drive transmission ratio can be switched on in the forward direction. 009840/11 Blank page