DE2050772B2 - CONTROL SYSTEM FOR AN INDEPENDENT MANUAL GEARBOX IN MOTOR VEHICLES - Google Patents

Description

The invention relates to a self-shifting motor vehicle change-speed transmission, and more particularly to a control system for automatically shiftable gearboxes in motor vehicles.

A self-shifting change speed transmission used in a motor vehicle usually includes planetary gear sets on, the respective rotary members and a number of friction elements, such as friction clutches and have brakes to control the circulation members in order to achieve a variety of translations create. In order to obtain different gear ratios, it is necessary to use one of the rotating elements to be kept stationary so that the particular rotary member is prevented from rotating in one direction. For this purpose, overrunning devices, such as one-way clutches and the like, are usually used to control the rotation to prevent the circulation member in this direction. However, if the drive direction is reversed, moves the freewheel device because of its inherent construction, so that the power flow is temporarily interrupted. The reverse drive condition is present during freewheeling, and this means that motor-related braking does not take place.

In a known control system for self-shifting change transmissions there is an additional friction element provided to prevent the reaction elements of the planetary gear sets from going in the reverse Direction to turn. This additional friction element must be brought into engagement by the driver using the selector lever, for example.

The invention is based on the object of a control system for an automatically shiftable change gearbox to create of motor vehicles in which the engine braking, e.g. B. when going downhill, takes place automatically.

In the case of a transmission of the type described at the outset, this task is performed in a control system the preamble of claim 1 solved with the aid of the means characterizing claim 1.

Further details of a control system according to the invention are shown below on the basis of exemplary embodiments with drawings.

F i g. 1 shows a block diagram of a control system according to the invention,

Fi g. 2 u'id 3 are examples of preferably chosen

Switching patterns that can be obtained with the arrangement shown in FIG.

F i g. 4 is a schematic view illustrating a hydraulic control system that is a part of the in FIG. 1 illustrated control system, and

F i g. Fig. 5 is a graphical representation of the reduction range that can be achieved using the hydraulic Tax system according to FIG. 4 is obtained.

The present invention is hereinafter described in a Application in a self-shifting gearbox described, for example, only three forward gears and has a single reverse gear and a torque converter and two planetary gear sets having. However, the control system of the present invention can also be used in a wide variety of applications Self-shifting gearboxes can be used, aie a centrifugal or electromagnetic clutch own and have one or three or more planetary gear sets that have more than three Result in forward gears.

As shown in Fig. 1, the change gear has a drive shaft tO and a driven shaft II. The drive shaft 10 is connected to a suitable drive machine, for example an internal combustion engine (not numbered), connected and driven by this; the driven shaft 11 is connected to the wheels (not shown) of the vehicle. The gear also has a turbine shaft 12 which is aligned with the shafts 10 and II. It also has one hydraulic torque converter 13 with an overrunning clutch 14, hydraulically operated friction clutches 15 and 16, hydraulically operated friction brakes 17 and 18, first and second planetary gear sets 19 and 20 and an overrunning clutch 21.

The hydraulic torque converter 13 has, as usual, an impeller or pump 13a, a Rotor or turbine wheel 136 and a stator or stator 13c. The pump wheel 13a is driven by the drive shaft 10 driven, and the turbine wheel 136 is firmly seated on the turbine shaft 12. The stator 13c is rotatable on a Hollow shaft 22 is arranged, and the one-way clutch 14 is between the stator 13c and the hollow shaft 22 arranged.

The overrunning clutch 14 can have any construction and is arranged so that a free Rotation of the stator 13c is only allowed in the forward direction of the vehicle, d. H. in the direction in which the drive shaft 10 rotates, and not in the reverse direction.

The torque converter 13 operates in a known manner to drive the turbine 136 with a torque which is greater than the torque communicated to the impeller 13a of the converter. The stator 13c changes the direction of flow of the fluid from the turbine 136 to the impeller 13a, 13a in order to transmit this increased torque to the turbine 136. The stator tends to rotate in the same direction as the direction in which the turbine and the impeller rotates when certain speeds of the two parts the latter have been reached, ^ ₀ whereupon the torque converter 13 operates simply as a fluid coupling in which the turbine 136 is driven at a substantially constant speed and without increasing torque with respect to the impeller 13a.

The first planetary gear set 19 has planetary members that have an inwardly toothed outer ring gear 23 have two or more planet gears 24, each meshing with the ring gear 23 to the outside, and a Sun gear 25 which meshes with the planet gears 24 to the outside. The planet gears 24 are of a Planet carrier 26 worn. The second planetary gear set 20 has in the same way rotating members that have an inwardly toothed outer ring gear 27, two or more planet gears 28, which outwardly with mesh with the ring gear 27 and are carried by a planet carrier 29, and a sun gear 30, which after meshes with the planet gears 28 on the outside. These circulating members are all rotatably concentric around one common axis connected to a driven shaft 11 which is connected to the planet carrier 26. As shown as an example, the sun gears are 25 and 30 of the first and second planetary gear sets 19 and 20 rigidly to one another via a hollow shaft 31 tied together. The planet carrier 26 is via the driven shaft 11 with the ring gear 27 of the second Planetary gear set 20 rigidly connected.

The friction clutch 15 can be of any suitable construction and is shown in FIG arrangement shown on a drive part 32 which is connected to the turbine shaft 12, a driven part 33, which is connected to the hollow shaft 31, which the sun gears 25 and 30 connects with each other. The clutch 15 can also have a servc mechanism 34 to the Drive position 32 to bring into and out of working engagement with the driven part 33 when a predetermined one hydraulic pressure is applied or released.

In the same way, the friction clutch 16 has a drive part 35 which is connected to the turbine shaft 12 and a driven part 36 connected to the ring gear 23 of the first planetary gear set 19 connected is. The clutch 16 also has a servo mechanism 37 to the drive part 35 with the to bring driven part 36 in and out of working engagement.

The brake 17 has a brake band 38 which can act on a brake drum 39 and the sun gears 25 and 30 brakes. The brake 17 is operated by a servo mechanism 40.

The brake 18 has a rotor part 41, which with the Carrier 29 of the planetary gear 28 of the second planetary gear set 20 is connected, and a stator part 42, which is connected to a stationary housing 43 of the transmission. The brake 18 is from a Servo mechanism 44 operated.

The one-way clutch 21 may be of any suitable construction so far as it can rotate freely of the rotor part 41 of the brake 18 in the direction in which the drive shaft 10 rotates, but not in the opposite direction.

The transmission provides three forward gear ratios and a single reverse gear ratio. A low speed forward gear ratio in first hand gear or in I position range is made by indenting the rear Clutch 16 and brake 18 set for slow speed and reverse speed. That from the torque converter Turbine torque built up 13 is then increased via the shaft 12 and the engaged clutch 16 the ring gear 23 of the first planetary gear set 19 distributed. The ring gear 23 brings the planet gears 24 to rotate in the direction in which the drive shaft 10 rotates. Accordingly, they rotate Sun gears 25 and 30 in the opposite direction to the direction of rotation of the shaft 12

Direction, so that the planet gears 28 of the second planetary gear set 20 rotate in the direction in which the drive shaft IG rotates. Then the brake 18 stops for slow running and reverse running, the planetary gear 29 is stationary, so that the ring gear 27 of the second Planetary gear set 20 rotates in the direction of rotation of the drive shaft 10. The ring gear 27 rotates so in this direction and thus brings the driven shaft 11, which is connected to the ring gear 27, daa.u, rotate in the same direction, thereby reducing the gear ratio for the first Forward gear is established.

The transmission power flow for the middle gear is set when the second brake 17 when further Increase in vehicle speed with the rear clutch 16 held in place. It will a transmission power flow established, which the turbine shaft 12 via the engaged rear clutch 16 with the Ring gear 23 connects. In this case, however, the second brake 17 works in such a way that the drum 39 is held stationary, and serves as a reaction brake to the rotation of the sun gears 25 and 30 impede. The planetary gear 24 therefore rotates around the sun gear 25, which is held stationary, and the Planet carrier 26 and accordingly the shaft 11 are driven at a speed which is lower than that Speed of the drive shaft 10 is. The middle gear or II speed range is set in this way.

The transmission power flow for high gear is set when the manual selector valve is in the D position is set so that the transmission system from the middle gear to the high speed gear switches. The transmission power flow for the high gear is set when the front clutch 15 in place of the second brake 17 is engaged when the vehicle speed with the rear held engaged Clutch 16 continues to rise. The power supplied by the turbine shaft 12 is, on the one hand, transferred to the ring gear 23 via the engaged rear clutch 16 and on the other hand to the sun gear 25 via the front one Transfer clutch 17. As a result, both the sun gear 25 and the ring gear 23 are locked so that all associated circulation members rotate at the same speed as the speed of the drive shaft 10. This establishes a direct transmission between shafts 12 and 11. On this condition For example, the torque converter 13 can simply operate as a fluid coupling, and so becomes essentially one direct transmission between the drive shaft 10 and its driven or output shaft 11 built.

Reverse gear is set by pulling the brake 18 with the front clutch held in 15 is tightened. The turbine torque built up by the torque converter 13 then becomes Distributed to the sun gears 25 and 30 via the shaft 12 and the engaged clutch 17. The sun gear 30 brings the planet gears 28 to opposite to the direction of rotation of the sun gear 30 Direction to turn. In this case, the planet carrier 29 becomes stationary by the brake 18 made so that the ring gear 27 of the second planetary gear set 20 moves in the same direction how the planet gears 28 moved. So the output shaft 11 is at a reduced speed in with respect to the drive shaft 10 driven in the opposite direction.

The friction clutches and brakes arranged in this way are illustrated in the block diagram in FIG illustrated hydraulic control system operated. The hydraulic control system has an oil pump 45 which a pressurized fluid leads to a fluid pressure line 46. The fluid pressure line 46 is in communication with a fluid pressure regulating valve 47. The line pressure regulator valve 47 is in communication with a pressure line 48 and operates in a known manner to control the fluid pressure to regulate in the pressure line 48. The pressure line 48 is connected to a line 49 in Connection, which in turn is connected to a throttle valve 50. The throttle valve 50 is via a Line 51 is operatively connected to the engine intake manifold and modulates the fluid pressure in Correspondence with the change in the negative pressure of the engine intake pipe. This modulated fluid pressure is then passed via a line 52 to a reducing valve 53. The reducing valve 53 can perform a reduction in the fluid pressure delivered by the throttle valve 50 to thereby further modulating the fluid pressure in a manner which will be discussed in detail. The so modulated fluid pressure is fed via a line 54 to the regulator valve 47, where it is used for Regulating the line pressure in the pressure line 48 to an optimal level is used to a Deliver torque that is suitable for the friction clutches and brakes. The line pressure in the Pressure line 48 is led to a manual valve 55.

This manual valve 55 is connected to a manual selector lever 57 via a mechanical linkage 56. The linkage is shown in FIG. 1 shown with a dashed line. The manual valve 55 has the following positions: / Or park position, R or reverse position, N or neutral position. D or automatic forward position, 2 or manual second gear and 1 or manual first gear. The manual lever 56 controls the manual valve 55 in order to set the transmission system for the desired speed ranges. The line pressure fed to the manual valve 55 is then fed via a line 58 to a first switching valve 59 and via a line 60 to a second switching valve 61. The first and second switching valves 59 and 61 work with each other in a manner to be explained in detail and supply the line pressure to the friction clutch 15, the second brake 17 and the brake 18 via guides 62, 63 and 64, respectively. Between the second switching valve 61 and the front clutch 15 is provided with an emergency valve 65 for slow speed, which prevents an upshift from middle gear to high gear if the control system breaks down. The one to the manual valve 5!

guided line pressure is via a line 6 <

also led directly to the rear clutch.

An important feature of the inventive i

Control system is that the first and second i Switching valve 59 and 61 each have two main positions

have, which are combined with working positions of a first to second solenoid 59a and 61a to eini Form a variety of gear ratios, as shown in Table I below.

In this table 1 "+" means that the together energier acting solenoids and switching valves

to set any given range, "-" means the cooperating solenoid and switching valves are controlled.

Table I

1. Solenoid valve
1. Switching valve

2. Solenoid valve
2. Switching valve

P -

D 1 (freewheel) + +

1 (motor- - +
braking)

As in Fig. As shown in Fig. 1, the electronic control circuit essentially comprises a switching pattern generator unit 70, a solenoid valve control unit 71, a gear ratio comparing unit 72, a Vehicle speed discriminator unit 73. a Motor protection unit 74, a downshift timing unit 75 and a line pressure control unit 76, The switching pattern generator unit 70 is via a line 78 with a variable resistor or potentiometer 77, via a line 84 / with an inclinometer 79, via a Leivung 82 with a brake switch 81, via a Line 84 to a motor thermometer device 83 and a line 86 to a first Speed generator 85 connected. The potentiometer 77 is connected to an accelerator pedal 87 to to determine its position and to generate a voltage signal that corresponds to the position determined corresponds approximately to the opening area of the engine throttle valve. The inclinometer 79 represents an inclination of the vehicle when the vehicle is traveling on an ascending or descending route, and generates a voltage signal that corresponds to the determined incline. The brake switch 81 can be on Generate voltage signal only when a - not shown - brake pedal is depressed. The engine thermometer device 83 determines the temperature at which the engine is operating and generates a voltage signal that corresponds to the determined temperature. Of the first speed generator 85 determines the speed of rotation of the output shaft 11 and generates a voltage signal that corresponds to the determined speed. Each of the voltage signals generated in this way is present via lines 78, 80, 82, 84 and 86, respectively of the shift pattern generator unit. The switching pattern generator unit 70 can generate a switching pattern for the selected gear ratio in accordance with the driving conditions of the vehicle for generation of a switching signal. The switch signal is passed on line 88 to the solenoid valve control unit 71 led.

The solenoid valve control unit 71 is connected via a line 90 to a selector switch 89 via a line 91 with the transmission ratio comparator unit 72. via a line 92 to the motor protection unit and via a line 93 to the unit 75 to temporal setting of the Heninterschaltens connected. The selector lever lock switch 89 is via a line 94 connected to the selector lever 57 and generates cm voltage signal that the selected speed range and is fed via line 90 to the solenoid valve control unit 71.

The gear ratio comparator unit 72 is not only connected to the first speed generator unit 85 via a line 86, but rather also via a line% with a second speed generator 95. The transmission ratio comparator unit receives signals provided by the first and second generator units 85 and 95 indicative of the engine speed and the Compare vehicle speed with each other ίο and one on a synchronized speed to generate related voltage signal. This voltage signal is via line 91 to the Solenoid valve control unit 71 and also via a line 98 to a throttle valve control unit 97 guided. The solenoid valve control unit 71 controls the position of the engine throttle valve to be equal to that Engine speed of the vehicle speed. When the engine speed is lower than the vehicle speed is, the throttle valve control unit 97 receives a signal via the line 98 and acts in the manner », that the opening area of the engine throttle valve is increased. This increases the engine speed. if the engine speed coincides with the vehicle speed, the gear ratio comparator unit generates 72 a corresponding signal, which is then sent via line 91 to the solenoid valve control unit 71 is applied for appropriate control of the solenoids.

The engine protection unit 74 is connected to the vehicle speed discriminator unit via a line 97 73 connected. The vehicle speed discriminator unit 73 is connected to the via lines 86 ″ and 86 first speed generator unit 85 connected and generates a voltage signal that of the speed the output shaft 11 corresponds. The voltage signal is fed to the motor protection unit 74, which is a Signal generated indicating the gear ratio desired for the vehicle speed. This The signal is then fed to the solenoid valve control unit 71 via line 92. That of the vehicle speed corresponding voltage signal is also via a line 98 to the unit 75 for timing of the downshift led. The downshift timing unit 75 causes a smooth downshift by setting the transmission system to a neutral state until the engine speed reaches a predetermined value. This neutral state is in the hereinafter referred to as the neutral interval. The neutral interval must be set so that it is suitable for a higher vehicle speed is longer. The downshift timing unit 75 generates a pulse with a width equal to the neutral interval; this impulse is then over the Line 93 led to the solenoid valve control unit. Thus, the solenoid valve control unit 71 holds the Transmission system for the duration of the pulse in the neutral interval in order to allow a smooth downshift to effect the gears.

The line pressure control unit 76 is connected to the vehicle speed discriminator unit via a line 99 73 and generates a signal corresponding to the vehicle speed signal that from the vehicle speed discriminator in-6s hcit 73 was delivered. The signal provided by the line pressure control unit 76 is then transmitted via a Line 100 is led to the reducing valve 53, thereby causing a reduction in the line pressure,

509 586/267

which is consequently reduced.

In FIGS. 2 and 3, selected examples of switching patterns that can be obtained when using the switching pattern generator unit 70 are shown. Fig. 2 illustrates the shift pattern obtained when the vehicle is driven on a flat road; Fig. 3 shows the shift pattern obtained when the vehicle is driven on an ascending or descending road. In Fi g. 2, curve abcde shows the shift point at which a shift is made from slow to middle gear, and curve afghi shows the shift point at which a shift takes place from middle gear to high, while curve ajkIm shows the shift point at which from high gear is shifted to the middle, and the curve anopq shows the shift point at which the shift is made from middle gear to low gear. When the vehicle is running on a flat road, the shift pattern generator unit 70 generates the shift signals for low, middle and high gear in accordance with the modes shown in FIG. 2 switching patterns shown.

Fig.3 illustrates how the switching pattern changed is used to raise the shift point to a higher vehicle speed when the vehicle is traveling on an uphill road when the engine is driving down on a sloping road brakes and when the engine is working at a low temperature. If that For example, the vehicle is driven on a road that is sloped at a certain angle, the switching pattern generator unit 70 generates the switching signal which is generated with the switching pattern according to FIG. 3 matches. The switching pattern can be obtained from the signal supplied from the engine thermometer device 82 can be changed in the manner previously explained. Furthermore, the switching pattern can be so be prescribed to change when the brake pedal 81 is stepped on. So generates the shift pattern generator unit 70 the switching signals for the low, middle and high gear in accordance with the driving conditions of the vehicle, these signals then being sent to the solenoid valve control unit 71 are performed. All of the shift pattern generator unit 70, the gear ratio comparator unit 72, the motor protection unit 74, the unit 75 for the timing of the downshift and signals supplied to the selector switch 89 become the Solenoid valve controller 71 out where it is in

converted to an appropriate electrical signal for controlling the first and second solenoids 59a and 61a to perform gear changes according to the shift patterns shown in Figs. the electrical signals are then sent over the wires

101 and 102 to the respective solenoids 59a and inserted.

The following Table II shows how the friction elements are engaged to increase the flow of force for each Build forward gear and reverse gear.

Elected Dialing range Front Rear Second position coupling coupling brake 15th 16 17th P. Park R. Backward + _ N Neutral - _ _ D. 1 (freewheel) - + 1 (engine braking) - + 2 - + E. 3 E. + _ II 2 - + E. I. 1 - + . P. Park - _ R. Backward + _ N Neutral - _ D. 3 + + II 3 + + I. 1 - + - E means: electronically operated. fleeing.

Slow and
-Reverse brake
18th

One-way clutch

21

+: in operation.
- : Out of service.

In Table II, the "+" sign is intended to mean that the corresponding friction element is in operation, and the sign "-" that the corresponding friction element is out of order. The letter "E" means that the friction element is electronically operated.

As can be seen from Table II, when the manual selector valve 55 is moved to P or shutdown, all friction elements are disengaged with the exception of the brake 18, which is engaged, so that the power transmission system is kept in a neutral interval. The purpose of engaging the brake 18 in this case is to carry out a smooth shift when the manual dial 55 is moved to the «position. As in

I abe le I are shown when moving the manual dial

valve 55 m the P or / V position both the first as

κ »also disengages the second solenoid valve 59a and 61a.

so aaü me power transmission in neutral

State can be maintained even if the

electronic control circuit fails.

6, γ, ρΓΤ J! ^Handwheel valve 55 in the «position

is moved. w, rd that of the manual selector valve 55

! 2,1, ^L , ^ei i " ⁿ S ^print over the first and second

Schaltver.t.l 59 and 61 to the servo mechanisms

out, the d.c corresponding friction elements 15

Engage and 18 to set reverse gear. In all forward gears (i.e. D, 11 and I areas), the rear clutch 16 serves as a power input clutch and is therefore directly from the line pressure applied to the servo mechanism of clutch 16 via line 66 is.

If the accelerator pedal 87 is stepped on and the selector lever 57 is in the D position, that is Shift signal for the first gear on lines 101 and 102 before so that the first and second solenoid 59a and 61a is energized, as in the previous one Table I is shown. In this case, the first and second switching valves 59 and 61 work together, to prevent the line pressure from zj the servo mechanism of the friction elements Ί5, 17 and 18 to be performed, as can be seen from Table II. The rear clutch 16, however, is through the line pressure in line 66 is actuated, and in addition to this, the one-way clutch 21 is actuated, so that the slow forward gear is obtained.

When the vehicle speed increases, the first solenoid valve 59a is de-energized, with the second Solenoid valve 61 a is kept energized by action of the solenoid control unit 71, and acts as has been described above, together with the second switching valve 61, whereby the engagement of the second brake is effected and a second or middle gear is obtained.

If the vehicle speed continues to increase, the first and the second will become so Solenoid valves 59a and 61a de-energize, as can be seen from Table 1, whereby the front clutch 15 is operated and so the high gear is set.

When the selector lever 57 is set in the range II, the first solenoid 59a is de-energized while the second solenoid valve 61a by the solenoid valve control unit 71 is energized so that the second brake 17 is engaged when the rear clutch 16 is held is operated. In this way, the manually set second gear is obtained.

When the manual lever 57 is set in the 1 range, the first solenoid 59a is energized. while the second solenoid 61a is de-energized, whereby the brake 18 is applied and so that of Manual slow gear is set.

If the selector lever 57 is accidentally shifted to the I range while the vehicle is at high When speed is in the D range, the electronic control system energizes the first solenoid 59a and 59a de-energizes the second solenoid 61a to change the gear ratio to the second speed of the power transmission system to shift by releasing the brake 18 and engaging the second brake 17.

In Fig. 4 shows in detail the hydraulic control system that differs from that shown in FIG electronic control circuit is controlled. As shown there, the hydraulic control system has an oil pump 45, a line pressure regulator valve 47, a throttle valve 50, a manual selector valve 55, a first switching valve 59 which cooperates with the first solenoid 59a, a second switching valve which cooperates with the second solenoid 61a cooperates, and the low-speed emergency valve 65. all these elements were described and illustrated.

The oil pump 45, which can be of any suitable construction, provides pressurized fluid from a tub 110 to a pressure line 111. This pressure line 111 is connected to the line pressure regulator valve 47 connected. The line pressure regulator valve 47 has a slidably movable valve spool 112 with a number of spaced shoulders 113, 114, 115 and 116 and regulates the fluid in of the pressure line Ul. The regulator valve 47 has gates 117, 118, 119, 120, 121 and 122. The gate 117 is with the reducing valve 53 in connection. The gate 118, which contains a throttle point 118a, is connected to the pressure line 111 in connection, with which the gates 119 and 120 are also in connection. The gate 121 stands with an oil circulation and lubrication circuit (not shown) in connection. Gate 122 is a drain gate through which the excess fluid in the pressure line 111 is vented to increase the line pressure to decrease. A spring 123 is used to bias the valve slide 112 in the direction - in the drawing - up. As shown, the regulator valve 47 is operatively connected to a booster valve 124.

The booster valve 124 has a slidably movable valve spool 125 with spaced apart Shoulders 126 and 127. On the Vertilschieber 125 a push rod 128 is arranged, which with the Shoulders 116 of regulator valve 47 work together to increase line pressure in pressure line 111 raise. The valve slide 125 is slidably arranged in a bush 129, the gates 130 and 131 having. The gate 130 is connected to the manual valve via a line 132 with a throttle point 132a contained therein 55 connected. The gate 131 is connected to a branch line 133a of the line 133, the is in turn connected to the throttle valve 50.

The throttle valve 50 has a slidably movable valve spool 134 which is located at a distance Has shoulders 135 and 136. The valve spool 134 includes a small bore 137th with a Valve chamber 138 is in communication. The throttle valve 50 has gates 139, 140 and 141. Gate 139 is a drain gate. Gate 140 is in with line 133 Connection, while the gate 141 is connected to branch line purple. There is one on shoulder 135 Push rod 142 of a throttle modulator valve 143 arranged with the (not shown) intake pipe of the engine is in communication. The throttle modulator valve 140 is operated in accordance with the change in negative pressure in the engine intake manifold, so that the push rod 142 moves in the direction the shoulder 135 moves. As a result, push rod 142 pushes valve spool 134 - in the Drawing - down. In this case, the fluid pressure in the port 141 becomes the valve chamber 138 of the throttle valve 50 and thus acts on the lower end of the shoulder 136. By this effect the fluid pressure is modulated to a value determined by the force applied to the Shoulder 135 acts. As a result, the fluid pressure in line 133 increases. if that Throttle valve is fully open and drops out when the throttle valve is slightly open, i.e. i.e. if the

do the negative pressure in the suction pipe is relatively high. Thus, the fluid pressure in port 140 depends on the negative pressure in the engine intake manifold and is used to change the line pressure. The fluid pressure is referred to below as the throttle pressure.

The throttle pressure in the line 133 is led to the gate 131 of the booster valve 124 and acts on the Shoulder 127 to move valve spool 125 up - in

the drawing - to move. This will make the Valve slide 112 of the regulator valve 47 is moved upwards and thus blocks the connection between the Gates ϊί9 and 121 and the connection between the Gates 120 and 122. In this way, the line pressure in the pressure line 111 is increased. If the negative pressure in the If the intake pipe increases, the line pressure in the control valve 47 increases accordingly. It should be noted that that as the throttle pressure increases, the line pressure decreases.

The throttle pressure in the line 133 is also sent to the reducing valve 53 via a branch line 1336 out, which contains a throttle point 144. The reducing valve 53 has a solenoid valve 145 for Actuation of a plunger 146 to open or close a nozzle 147 when energized by the Line Pressure Control Unit 76 (see Fig. 1). The reducing range of the reducing valve 53 is shown in FIG. 5 illustrated.

The cross-sectional area of the nozzle 147 is larger than that of the throttle point 144, so that the fluid pressure in a fluid chamber 148 is higher than the throttle pressure in line 133.

The fluid pressure in the fluid chamber 147 is changed and conducted via a line 149 to the port 117 of the regulator valve 47 in order to regulate the line pressure in the pressure line 111. The line pressure regulated in this way is then fed via a line J11 or the manual selector valve 55.

The manual selector valve 55 is operated by the manual selector lever 57 (see Fig. 1). As described above, the selector lever 57 can assume the following positions: P or park position, R or reverse position, N or neutral position, D or automatic forward drive position, 2 or manually adjustable second gear and 1 or from Hand adjustable first gear. The manual selection valve 55 has corresponding positions, as shown. The line pressure supplied to the manual selector valve 55 is fed to the first switching valve 59 via the lines 161 and 162.

The manual selector valve 55 has a slidably movable valve spool 150 which has spaced shoulders 151, 152 and 153. The manual valve 55 has a number of gates 154, 155,156,157,158,159, and 160. The gateway 154 communicates with the line 111 b in connection leading to the pressure line 111; port 155 is in communication with line 132; gate 156 is a drain gate; the gate 157 is in communication with a line 161; the port 158 is in communication with a line 162; the gate 159 is connected to a line 163 and the gate 160 is connected to a line 164, which in turn is connected to the rear coupling 16 via an opening 164a.

The first switching valve! 59 includes a slidably movable valve spool 165 which is spaced located shoulders 166, 167, 168 and 169 has. The switching valve 59 has a number of gates 170, 171, 172, 173 and 174. Gate 170 selectively communicates with gate 172, while gate 171 selectively communicates with one of the gates 172 and 173 is in connection. Gate 174 is a drain gate. A spring 175 tensions the Valve slide 165 - in the drawing - to the left. On shoulder 166 is a plunger 176 of the first Solenoids 59a arranged. The solenoid 59a, which may be of any suitable construction, is controlled by the solenoid valve control unit 71 is controlled in a manner previously described. The gates 172 and I73 are in connection with lines 177 and 178, respectively, di in turn are in connection with the second switching valve 61.

The second switching valve! 61 has a slidably movable valve spool 179 which has spaced shoulders 180, 181, 182, 183 and 184. The switching valve 61 has a number of goals 185,186,187,188,189,190,191 and 192. The gates 185 and 186 are connected to the lines 178 and 177 j _n connection. Gates 187, 190 and 192 are exit gates. The gates 188, 189 and 191 are in communication with the corresponding friction elements. A spring 193 is used to bias the valve slide 179 - in the drawing - to the left. A plunger 194 of the second solenoid 61a is arranged on the shoulder 180. The second solenoid 61a, which may be of any suitable construction, is controlled by the solenoid valve control unit 71 as previously described.

The gate 188 is connected to a line 195 j _n , which in turn is connected via a throttle point 95, - ₍ with the application side of the servomechanism 40 of the second brake 17. The gate 191 is connected to a line 196, which is a throttle point 196a and is in turn connected to the brake 18.

The gate 189 is connected to a line 197, which in turn is connected to the slow-speed emergency valve 65 communicates. The low-speed emergency valve 65 has a slidably movable valve slide 198 having spaced shoulders 199 and 200. A spring 201 is used to bias the Valve slide 198 - in the drawing - to the right. The low speed emergency valve 65 has a number of Gates 202, 203 and 204. Gate 202 is connected to line 197. The gate 203 stands with the Line 163 in connection, which leads to the manual selector valve 55. The gate 204 stands with a line 205 in Connection, in turn, with the relief side of the servomechanism 40 and with the front clutch 15 is in communication via a throttle point 206.

When the manual selector valve 55 is in the P position is set, the valve spool 150 is so moved; that gate 154 with gates 157 and 155 in Is associated. The line pressure supplied to port 157 then becomes through line 161 to the Gate 170 of the first switching valve 59 out. In this case, the first solenoid 59a is de-energized, so that the Valve slide 165 by the force of spring 175 - in the drawing - is moved to the left. If the Ventilschicoer 165 is in this position, the gate 170 is connected to the gate 172 so that the to The line pressure supplied to the port 172 is passed via the line 177 to the port 186 of the second switching valve 61 will. The second solenoid 61a is also de-energized, so that the valve spool 179 by the force of the spring 193 - in the drawing - is moved to the left. As a result, gate 186 is in with gate 191 Connection, allowing line pressure into the line 1%. So the brake becomes 18 created.

On the other hand, the line pressure admitted to the port 155 is through the line 132 to the port 130 of the Booster valve 124 out. The line pressure in port 130 then acts on the differential area between the shoulders 126 and 127 and thus moves the valve spool 125 - in the drawing - after

up to increase the line pressure in pressure line 111. Applying the brake 18 and increasing it of the line pressure is used to carry out a quick switch from the P position to the Ä position and to increase the torque capacity of the brake i8.

When the manual valve 55 is in the /? Position is switched, the line pressure is fed to the same lines as in the case that the manual valve is switched to the P position with which Except that line pressure is supplied to line 162. In this case, both solenoid 59a and the solenoid 61a deenergized, so that the connections between the ports 171 and 133 and are set up between gates 185 and 189. As a result, that is supplied to line 162 Line pressure is conducted via lines 178 and 197 to gate 202 of low speed emergency valve 65. In in this case there is no line pressure acting on shoulder 200 because line pressure is applied to it is prevented from being led to the line 163, so that the valve spool 198 by the force of the spring 201 - in the drawing - is moved to the right. When the valve slide 198 is in this position is located, the port 202 is in communication with the port 204 and thus allows line pressure to be applied front clutch 15. The front clutch 15 is then engaged., ur.d so the reverse gear obtain.

When the manual selector valve 55 is in the AZ position (illustrated in FIG. 4) is switched, the line pressure supplied to port 154 is via port 157 left only to line 161, in this case the Brake 18 applied as described above. So the transmission system is in its neutral State switched, which means that it is through the switching from the AZ position to the /? position resulting impact is decreased.

When the manual valve 55 is moved to the D position, the line pressure in the port 154 not only becomes to gate 158, but also to gate 160. The line pressure admitted to port 160 is led directly to the rear clutch 16 via line 164. So is the rear clutch 16 for all forward areas always indented.

Since the electronic control circuit has the first and second solenoids 59a and 61a in one of the tables in Table I. energized and de-energized as described, the forward range is determined by the switching signals that to the solenoids 59a and 61a.

When the first gear shift signal is generated from the solenoid valve controller 71, both the first and second switching valves 59 and 61 energized, so that the plungers 176 and 194 to Stand out. As a result, the valve spool 165 and 179 are against the forces of the springs 175 and 193 - in the drawing - moved to the right. In this case, gate 171 is in with gate 172 Connection whereby line pressure is directed to port 186 via line 167. Gate 186 is but closed by the shoulder 183 of the second switching valve 61, so that in the line 196 no Line pressure is present. Thus, only the rear clutch 16 is engaged and therefore first gear is through Effect of the one-way clutch 21 obtained.

When the vehicle speed increases at the shift point from first to second gear, the first With the second solenoid 61a kept energized, the solenoid 59a is de-energized by the solenoid valve control unit 71, so that the valve spool 165 of the first switching valve 59 by the force of the spring 175 - in the Drawing - is moved to the left. In this case the gate 171 is connected to the gate 173, whereby the line pressure is supplied to line 178. Since the gate 185 is connected to the gate 188

ίο is the line pressure delivered to line 178 left to line J95 leading to the access side the servo mechanism 40 leads to the second brake 17 to apply. That’s second gear set.

When the vehicle speed continues to increase, both the first and second solenoids are 59a and 61a are de-energized so that the connections between ports 171 and 173 and between ports 185 and 189 are made. In this case, there is no line pressure in gate 203 of the slow-speed emergency valve 65, whereby the valve slide 198 by the force of the spring 201 - in the drawing - moved to the right to establish the connection between the ports 202 and 204. As a result, that of line 162 supplied line pressure is released to the front clutch via lines 178, 197 and 205, and therefore third gear is reached.

When the manual valve 55 is moved to the range II position, the line pressure becomes left the same line, as in the case that the manual selector valve 55 is in the D position when the Vehicle is driven in second gear.

When the manual valve 55 is switched to the! Position, the line pressure to the ports is increased 158,159 and 160 left. When the manual valve 55 is in this position, the first solenoid is 59a energized while the second solenoid 61a is de-energized, so that the connections between the Gates 171 and 172 and between gates 186 and 191 are made. The one admitted to the Leiturg 162 Line pressure is then supplied to the brake 18 via lines 177 and 196. This is how first gear will be obtained, whereby the engine braking by the action of the brake 18 is brought about. If that is electronic Control system fails, either solenoid 59a or solenoid 61a goes out of order, so that when the manual selector valve 55 is set to the positions of the range D and II, the third gear is obtained. However, when the manual valve 55 is switched to the position of the range 1, that becomes the Line 197 is prevented from reaching line 205, which is to the front Coupling 15 leads, as the line pressure carried to port 159, via line 163 to port 203 is left and thus acts on the shoulder 200 of the slow-speed emergency valve 64. Under these conditions the rear clutch 16 and the one-way clutch 21 come into operation, and so the first Get gear.

Although the switching valve is operated directly by the solenoid as shown, can a suitable control device, such as a pilot valve, between the switching valve and the solenoid im If necessary, be provided.

For this purpose 3 sheets of drawings

Claims (2)

Claims: 20 772 1. Control system for an automatically shiftable change gear of motor vehicles with a motor shaft (10), an output shaft of the change gear (11), a plurality of planetary gear sets (19, 20) which are arranged between these two shafts (10, 11), a plurality of friction clutches (15, 16) and brakes (17, 28) for controlling the relative movement of the planetary gear sets, the friction clutches and brakes expanding a slow-speed and reverse brake (18) to produce a friction connection between the two shafts, with d <; r an engine braking effect is achieved when the first forward gear is engaged; with a freewheel brake (21) which alternates with the slow and reverse brake (18) and a freewheel connection between the motor shaft (10) and the output shaft (11) of the gearbox produced when the slow and reverse brake (18) is disengaged; with a plurality of hydraulic servomechanisms (34, 37, 40 and 44) for the actuation of the friction clutches and brakes, the control system having a fluid pressure source (45) and a first and a second switching valve (59 and 61) which hydraulically divide the pressure -Source (45) and the servo mechanisms are connected and, when they move, between two extreme positions selectively produce hydraulic connections for actuating selected friction clutches and brakes for a desired gear ratio; each having a first and a second solenoid (59a and 61a) which actuate the first and second switching valves (59 and 61), respectively; with a first electrical transmitter (85) for generating a signal that is proportional to the speed of rotation of the output shaft (11) of the gearbox, a second electrical transmitter (77) for generating a second signal that is proportional to the position of an accelerator pedal ( 87) is; with a shift pattern generator unit (70) which is connected to the first and the second transmitter for receiving these signals and generates an output signal which corresponds to the gear ratio to be shifted as a function of these signals, the shift pattern generator unit (70) electrically connected to the first and second solenoids (59a and 61a) responsive to these output signals to automatically control the first and second switching valves (59 and 61), respectively. and wherein, by selectively combining the two positions of the first switching valve (59) with the two positions of the second switching valve (61), a plurality of lines (195, 196 and 197) for selectively supplying hydraulic pressure to the servomechanisms of the friction clutches and brakes (15 , 17 and 18) can be used, characterized in that a first freewheel forward gear, a first engine braking forward gear, a second forward gear and a third forward gear can be switched in a known manner by controlling the relative movements of the planetary gear sets and that the switching pattern Generator unit (70) is electrically connected to an inclinometer (79) which provides a signal when the vehicle is traveling on a slope towards which the shift pattern generator unit (70) energizes the first and second solenoids (59a and 61a) thereby causing the first and second switching valves (59 and 61) to apply hydraulic pressure to the servomechanisms for the slow and reverse brake (18). 2. Control system according to claim 1, characterized in that the generator unit (70) with a brake switch (81) is connected, which when depressing the brake pedal while driving the vehicle generates a signal from a mountain which is supplied to the sound pattern generator unit (70), whereby a switching point changes in the direction of a higher driving speed.