DE1211496B - Hydraulic control device for a gearbox, especially for motor vehicles - Google Patents

Description

Hydraulic control device for a gearbox, in particular for motor vehicles The invention relates to a hydraulic control device for a change gear, especially for motor vehicles, in which one driven by the engine Input shaft via a hydrodynamic coupling with your input element of a of two planetary gears having a common output shaft and over a hydraulic fluid operated clutch with the input element of the other planetary gear is connectable.

Have change gear with such branched torque transmission the advantage that the hydrodynamic coupling enables a quick start-up the hydrodynamic coupling does not cause an excessive loss of power such drive conditions results in which they are not switched into the power path is.

The filling and emptying of the hydrodynamic coupling, however, takes place Problems, as the filling of the clutch for switching the drive on the 2 ugled Power path to the loosening of any of the clutches to achieve the drive must be agreed on the other performance path. In addition, the filling and Emptying the hv-drodynamic clutch at different speeds different drive conditions occur when a best working method is achieved should have been.

To solve these problems, the invention is based on the idea that a fluid pump of variable flow rate with one of the speed of the Input shaft is driven proportional speed and hydraulic fluid for the engagement of the (mechanical) clutch and'or the filling of the hydrodynamic Coupling provides and that the relief of fluid pressure in the hydrodynamic Clutch or the hydraulic fluid-operated (mechanical) clutch so on the Supply of hydraulic fluid to other of these facilities is coordinated that during a gear change, the input shaft temporarily changes its speed and thus the pump flow increases so that the completion of the gear change accelerates will.

The invention is therefore that one in a known manner with a speed proportional to the speed of the input shaft driven liquid pump variable delivery rate supplies a main delivery line with hydraulic fluid, those for engaging the hydraulic fluid-actuated clutch and / or filling the hydrodynamic Clutch is used, and that when disengaging the hydraulic fluid-actuated clutch and filling the hydrodynamic clutch for the purpose of downshifting by a Switching valve a delivery line connected to a hydraulic clutch accumulator separated from the main delivery line to the pressure-actuated coupling and rit is connected to a line in which the pressure passes through the pressure-sensitive Member of a downshift valve is held at a low value. so that Slip occurs in the hydraulic fluid-actuated clutch and see the speed the motor-driven input shaft and thus the delivery rate of the liquid pump increased, this low pressure being fed to a clutch signal valve, the increased delivery rate of the hydrodynamic pump delivered into the main conveyor line Clutch which is quickly filled to complete the downshift.

This leads to the mutual interaction of the clutches smooth, jerk-free gear changes in all conditions.

In a further embodiment of the invention, the pressure-sensitive Member of the down-switch valve to a pressure corresponding to the engine torque and in the opposite direction of the force of springs and the low pressure in the exposed to the line connected to the delivery line. It is also proposed that that to control the increased pump flow from the main delivery line to hydrodynamic Clutch the clutch signal valve a pressure pulse via a line to a clutch filling valve feeds, which moves its valve member against the force of a spring, to a delivery line for the hydrodynamic coupling to be connected to the main delivery line.

Further features of the invention emerge from the claims. For Claims 4 to 10 will only be protected in connection with the preceding ones Claims claimed.

In the drawings, an embodiment of the subject matter of the invention is shown. FIG. 1 shows an overview sketch of the mutual position of the other figures, FIG. 2 shows a schematic representation of a transmission according to the invention and FIG. 2 a, 2 b, 2 c, 2 d, 2 e and 2 f representations of the individual parts of a control device for the transmission according to the invention. The gearbox The primarily in F i g. 2 transmission shown has a with a power source, for. B. a motor vehicle engine, not shown, connected input shaft 10 and an output shaft 12 which is connected to a gear 14 of a conventional, not shown rear axle drive. The transmission shown is divided into a main part and an auxiliary part, which are located in front of and behind the rear axle drive. However, other types of transmission are also possible, so the two transmission parts can also be combined and arranged either as a unit behind the engine or close to the rear axle drive on one side thereof.

The main part of the transmission consists of a front planetary gear set 16 and a rear planetary gear set 18, which are connected to one another so that they result in three forward gears and one reverse gear. The front planetary gear transmission 16 has a ring gear 20 as an input and a sun gear 22 as a reaction part, both of which mesh with a set of planet gears 24 which are rotatably mounted in a planet gear carrier 26 serving as an output. The planetary gear carrier 26 is connected to a planetary gear carrier 28 which forms the output of the rear planetary gear transmission 18 and which is connected to an intermediate shaft 29 which is guided to the rear. The planetary gear carrier 28 carries planetary gears 30 which mesh with a sun gear 32 working as an input and a ring gear 34 serving as a reaction part. The reaction wheels 22 and 34 of the two planetary gears 16 and 18 are connected to one another and are secured against reverse rotation by the combined action of a one-way lock 36 and an idle brake 38. The idle brake 38 can hold the outer race 40 of the one-way lock 36 in both directions. The one-way barrier 36 may be of a known type, e.g. B. with spreader members or rollers. be provided which allow a relative rotation of two parts in one direction and prevent in the other direction. An overrunning brake 42 is provided to prevent the reaction wheels 22 and 34 from rotating in either direction when engine braking is required.

The input shaft 10 to the front and rear planetary gears 16 and 18 is driven with different ratios by a device 44 transmitting a hydrodynamic torque. This is shown as a hydrodynamic coupling, the pump wheel 46 of which is driven by the input shaft 10 and the turbine wheel 48 of which with the input sun wheel 32 of the rear planetary gear train 18 and / or is rotatable by a clutch 50 which is provided between the input shaft 10 and the input ring gear 20 of the front planetary gear train 16.

The auxiliary part of the transmission includes an overdrive planetary gear train 52 to obtain direct drive or overdrive. This overdrive planetary gear transmission 52 has as input a planet gear carrier 54 which rotates with the intermediate shaft 29 and is mounted on the planet gears 56 which mesh with an output ring gear 58 connected to the output shaft 12 and a sun gear 60 acting as a reaction part. The sun gear 60 can be held in place by an overdrive brake 62 in order to maintain the overdrive. A clutch 64 is provided between the planetary gear carrier 54 and the sun gear 60, which, when engaged, blocks the planetary gear transmission 52 in order to obtain direct drive.

When releasing the overdrive brake 62 and engaging the clutch 64, a brief interruption of the drive from the intermediate shaft 29 to the output shaft 12 is avoided by a one-way lock 66, which is also arranged between the planetary gear carrier 54 and the sun gear 60. This one-way lock 66, which can be designed in the same way as the one-way lock 26, can couple the planet gear carrier 54 to the sun gear 60 so that the sun gear rotates forward at the speed of the planet gear carrier 54. However, the one-way lock prevents the sun gear 60 from running faster than the planet gear carrier 54. Mode of operation of the transmission The transmission described allows operation in neutral, in at least six forward gears and in reverse.

Idle is achieved by releasing the idle brake 38, so that neither the front nor the rear planetary gears 16 and 18 have a support and therefore there is no drive to the intermediate shaft 29 from the input shaft 10 can. The clutch 64 is engaged and the hydrodynamic clutch 44 in preparation filled for the first course.

In first gear, the hydrodynamic coupling 44 remains effective and the idling brake 38 is applied while the coupling 64 is already engaged. The input shaft 10 then drives the input sun gear 32 of the rear planetary gear train 18 via the hydrodynamic coupling 44. Since its reaction wheel 34 is prevented from rotating backwards by the one-way lock 36 and the idle brake 38, the planetary gear carrier 28 of the rear planetary gear transmission 18 will rotate forward at a reduced speed according to the ratio of the number of teeth of the gears 32 and 34. The front planetary gear set 16 will still be ineffective at this time because the clutch 50 is disengaged. The ring gear 20 is driven faster than the planet gear carrier 26. When the clutch 64 is engaged, which blocks the overdrive planetary gear transmission 52, the drive from the intermediate shaft 29 to the output shaft 12 will then take place with a gear ratio determined by the rear planetary gear transmission 18.

A first intermediate course for reasons that will become apparent (or l '/ 2-speed) to get designated gear, the overdrive planetary gear transmission 52 made effective by the overdrive brake 62 being applied and the clutch 64 are disengaged, the planetary gears 16 and 18 remain unchanged. The intermediate shaft 29 will then try to drive the sun gear 60 of the overdrive planetary gear train 52 to rotate forward. However, this is prevented by the overdrive brake 62, so that the ring gear 58 and the output shaft 12 faster than the intermediate shaft 29 and the planet gear carrier 54 are driven. The transmission ratio results is then derived from the product of the ratios of the rear planetary gear 18 and the overdrive planetary gear transmission 52.

For the second gear, the hydrodynamic clutch 44 is emptied, the clutch 50 is engaged and the overdrive planetary gear transmission 52 is downshifted, that is, the clutch 64 is engaged and the overdrive brake 62 is released. The input shaft 10 then drives the input ring gear 20 of the front planetary gear via the clutch 50 16 at. Since its reaction sun gear 22 is rotating backwards through the one-way lock 36 and the idle brake 38 is prevented, the planetary gear carrier 26 of the front planetary gear 16 driven at a lower speed, which is from the ratio of the number of teeth of the wheels 20 and 22 results. The drive is running from the planetary gear carrier 26 to the planetary gear carrier 28 of the rear planetary gear 18, the intermediate shaft 29, the overdrive planetary gearbox blocked by the clutch 64 52 to the output shaft 12, the transmission ratio through the front planetary gear 16 is determined. When the hydrodynamic clutch 44 is empty, the rear planetary gear is in place 18 ineffective and his sun gear 32 can forward unhindered faster than the planet carrier 28 run.

A second intermediate course can be obtained in certain circumstances. The front and rear planetary gears 16 and 18 remain unchanged, while the overdrive planetary gear transmission 52 is switched to overdrive. The total gear ratio is then the product of the gear ratio of the second Ganges with that of the overdrive planetary gear.

The hydrodynamic clutch 44 is used again for third gear filled and the clutches 50 and 64 engaged. The drive then goes from the input shaft 10 via the clutch 50 to the input ring gear 20 of the front planetary gear 16 and via the hydrodynamic coupling 44 to the input sun gear 32 of the rear Planetary gear transmission 18. The wheels 20 and 32 are at approximately the same angular speed driven, the sun gear 32 runs a little slower because of the slip losses in the hydrodynamic coupling 44. There are therefore the front and the rear planetary gear 16 and 18 blocked and result in direct drive, the reaction wheels 22 and 34 run forward unhindered by the one-way barrier 36. From the planetary gears 16 and 18 the drive goes through the intermediate shaft 29 through the overdrive planetary gear 52 to output shaft 12. The gear ratio is about 1: 1.

Fourth gear can be achieved by disengaging clutch 64 and the overdrive brake 62 is applied, whereby overdrive in the planetary gear train 52 results. Its gear ratio will be that of fourth gear, since the Planetary gears 16 and 18 through the fluid coupling 44 and the clutch 50 remain blocked.

For the reverse gear, a reverse gear brake 67 is applied, which prevents the ring gear 20 of the front planetary gear transmission 16 from rotating. if in the drawing this brake is also drawn as a cone brake, the use would be a multi-disc or band brake possible. The hydrodynamic coupling 44 is as well as the clutch 64 of the overdrive planetary gear transmission 52 effective while the rest of the clutches and brakes, with the exception of the reverse brake, are disengaged are. The drive comes from the input shaft 10 via the hydrodynamic coupling 44 to the input sun gear 32 of the rear planetary gear transmission 18, whose ring gear 34 is driven in reverse because the idle brake 38 is released. It takes that Sun gear 22 with the front planetary gear transmission 16, which is due to the reverse brake 67 fixed ring gear 20 the planet carrier 26 at a reduced speed drives backwards. The planetary gear carrier 28 of the rear planetary gear train 18 and the intermediate shaft 29 are driven backwards and there the overdrive planetary gear 52 is blocked, the input shaft 12 is at the same speed as the planet carrier 26 of the front planetary gear 16 driven backwards.

The main part of the transmission offers three forward and one reverse gears and could be used separately from the accessory if desired. Will however additional gear ratios desired, and in particular an overdrive for reasons of economy, the overdrive planetary gear can be used the first intermediate course, the second intermediate course and the fourth course are enabled. The control device The various brakes and clutches mentioned as well as the hydrodynamic coupling 44 are all fluid operated in the correct order Servos of a hydraulic control device are controlled, which are shown schematically in the drawings is shown. The servos of the brakes and clutches have been given the same reference numbers like this one with the addition of a comma. Each servo can be of the usual type be in which a piston by the servo supplied hydraulic fluid in the position is moved, in which the associated brake or clutch is operated.

The pressure fluid is fed to the control device by a pump 100 with a variable delivery rate (FIG. 2 d). The pump 100 has a sliding piece 102 which is guided up and down in sliding guides of the pump housing and to which the other pump parts are arranged so that the delivery rate of the pump is dependent on the position of the sliding piece 102 in the pump housing. A spring 104 pushes the slider 102 towards its position for the largest flow rate. The pump 100 is expediently driven by the input shaft 10 so that it begins to work when the vehicle engine is started. The pump 100 sucks in from a sump (not shown) via a suction line 106 and conveys the liquid into a main delivery line 108. Pressure control valve 110 The pressure of the liquid delivered by the pump 100 into the main delivery line 108 is controlled by a pressure control valve 110. This has a valve slide in a valve housing. The pressure from the main delivery line 108 is supplied via a branch line 112. The valve slide 110 has several control collars 114, 116, 118 and 120 that are spaced apart from one another. The valve slide 110 is loaded upward by a spring 122 against the fluid pressure entering from above through the branch line 112. The valve slide 110 has a central channel 124 which is open at the top and which leads to a transverse channel 126 located between the control collars 116 and 118. In the position shown, the fluid pressure from the line 112 acts on the upper surface of the valve slide 110 and presses it downwards against the spring 122, so that fluid flows via the channels 124 and 126 to a channel 128 which is on the underside of the slide piece 102 leads. A channel 130, which leads to the top of the slider 102, is in communication with an outlet 132 between the control collars 118 and 120. The liquid pressure on the underside of the slider 102 thus supports the spring 104 in order to move it into the position of the greatest delivery rate. If the pressure in the branch line 112 increases, the valve slide 110 moves downwards and the channel 128 is connected to an outlet 134 between the control collars 114 and 11.6 , while between the control collars 116 and 118 the channel 130 is connected via the channels 124 and 126 Hydraulic fluid flows in. This pressure moves the slider 102 downwards and reduces the delivery rate of the pump 100.

In operation, the valve slide 110 is between these two positions Commute and pressurized fluid on either the top of the slider via the Lead line 230 or its underside via line 128. The slider 102 sets itself in such a position that the delivery rate is sufficient to get one through the spring 122 to generate a certain delivery pressure. This regulation is permanent instead, so that in the main conveyor line 108 a relatively constant Sets the pressure, for example 7.04 kg / em2.

Selector valve 140 The main delivery line 108 leads to a manually operated selector valve 140 (FIG. 2 c), the valve slide of which is displaceable in a valve housing and has spaced apart control collars 142, 144 and 146. At the right end the valve slide has two flanges 148, 150, between which a fork (not shown) engages, through which the driver can move the valve slide 140 axially into one of the following positions: P - Parking; N - idle; D - drive area; l - middle drive range; L - low drive range. These settings correspond to the various gear settings that can be achieved with the control device. A position R for reverse gear is also provided. Check valve 160 Below the selector valve 140 is shown in FIG. 2 c shows a blocking valve 160, the valve slide of which is seated in a valve housing and is pressed into the illustrated Aufschaltsteliung by a spring 162. The valve slide has several control collars 164, 166, 168 and 170 which control several lines to be explained later. A control chamber 172 is provided at the end opposite the spring 162. Pressure fluid flows from the selector valve 140 via a line 174 and a branch line 176 to the shut-off valve 160. The pressure in the control chamber 172 acts on the end face of the control collar 170 in order to move the valve slide to the left into the downshift position. At the other end of the valve slide 160, a further control chamber 178 is provided, which is supplied with pressure fluid from the selector valve 140 via a line 180. A throttle point 182 in the line 180 controls the flow to the control chamber 178, while the outlet from this is determined by a throttle point 184 with a larger cross section.

The outflow of the liquid from the control chamber 178 via the throttle point 184 is controlled by a relay 186 which can be excited by a coil 187. This coil 187 is connected to the vehicle battery 192 via a conductor 188 containing a switch 190 and is connected to ground 194. The shut-off valve 160 is used for forced downshifting in that when the accelerator pedal 196 is depressed a certain amount, the switch 190 closes and the relay 186 closes is excited. Then its armature 198 is rotated counterclockwise about a pivot point 200 and pulls a valve stem 202 attached to it downwards. In the position shown, the valve stem 202 closes the throttle point 184, which is opened when the relay is energized in order to empty the control chamber 178. The force due to the pressure in the control chamber 172 is greater than the counteracting force of the spring 162 and the check valve 160 is therefore moved to the left into the downshift position. Since the throttle point 182 has a smaller cross section than the throttle point 184, the control chamber 178 can drain without any significant influence on the pressure in the line 180. TV valve 220 A line 218 leads from the selector valve 140 to a TV valve 220 (FIG. 2 c). Its valve slide has several control collars 222, 224, 226 and 228, of which the control collars 222 and 224 have the same diameter, while the control collars 226 and 228 each have a larger diameter. Expandable chambers in the form of bellows are provided at each end of the valve spool 220. A bellows 230 influenced by the outside air pressure is attached to the left end and a bellows 232 influenced by the engine intake pressure is attached to the right end. Each bellows 230 and 232 contains an internal spring which tends to expand it. The bellows 232 is connected to the engine intake line (not shown) by a line 234, while the bellows 230 is evacuated and sealed against the air inlet.

D "s' T-V valve 220 wij-ci c? Über develop a or T-V pressure, which depends on the engine torque and also on changes in the outside air pressure. When the engine is idling, there is a very high negative pressure in the intake line in relation to the external pressure, which in future will be referred to as the maximum suction pressure. At this maximum suction pressure, the bellows 232 will contract and the valve slide Move 220 to the right. When the engine is at full load, the intake pressure is increased if he also remains negative; this pressure is called the minimum suction pressure. At minimal Suction pressure will expand bellows 232 and valve spool 220 to the left move.

The T-V valve 220 regulates the pressure in the usual manner. For easy Understanding, it is assumed that the valve slide 220 has a constant bias is exerted to the left by the bellows 232. Assuming that this bias sufficient to cause the opening of the line 218 by the control collar 222, pressure fluid will flow on both sides of the control collar 226 and it will the valve slide 220 is moved to the right until the control collar 228 a Exposed outlet 238 so that the pressure is lowered. The permanent pre-load of the valve slide 220 to the left causes its oscillation, so that a regulated Control pressure or T-V pressure is fed to a line 236, the value of which depends on the Pre-loading of the valve is determined.

The maximum and minimum TV pressure can have any desired value. Merely for the sake of explanation it is assumed that when the engine is idling and the intake pressure is at maximum, the load on the valve slide to the right is sufficient to close the line 218 through the control collar 222 and to open the outlet 238 so that the TV pressure becomes zero. At minimum intake pressure, such as at full torque of the engine, the preloading of the TV valve slide 220 to the left will be greatest and the line 218 vaird opened sufficiently to switch off the control action of the TV valve. The TV pressure in line 236 will then be the same as in line 218. Between these maximum and minimum values of the TV pressure, the TV valve 220 will regulate the pressure in the manner described.

The bellows 230 adjusts the T-V pressure to changes the outside air pressure. The outside air pressure acts on the outside of the bellows 230 on and when the external pressure decreases, e.g. B. at a greater height, the bellows expands 230 and pushes valve spool 220 to the right to lower the T-V pressure. Vice versa If the outside air pressure is higher, the bellows 230 is compressed and adjusts the Valve spool 220 to the left to increase T-V pressure. The bellows 230 can with a set screw 240 at its left end.

In general, the available engine torque of an engine decreases a given speed with the outside air pressure. For a smooth gear change is a lower T-V pressure is desirable if the torque is lower. Since the Suction pressure is not displayed to the same extent as the outside air pressure changes, the two bellows 230 and 232 cause a T-V pressure that compensates both is. As will be described, the T-V pressure thus obtained serves together with controller pressures to determine the switching points of the gearbox. Without consideration of the engine torque changes, the switching would occur at the same points want, despite the reduction in torque, and thereby become harder than if switching occurs at the peak torque speeds of the motor. Regulator 250 A hydraulically operated regulator 250 (FIG. 2 f) is driven by the output shaft 12 driven at a speed proportional to the driving speed of the vehicle. A branch line 252 from the main delivery line 108 supplies the regulator with hydraulic fluid, which delivers two levels of pressures that depend on the speed at which it is driven will be determined. The first of these pressures, G-1 pressure, enters a line 254, the second G-2 print generated at a different speed becomes one Line 256 passed. Both pressures, G-1 and G-2, change with vehicle speed.

Idle brake valve 300 In the upper part of FIG. 2b is an idle brake valve1300 shown, the valve slide in a remote bore of the valve body slides. The valve slide has control collars 302, 304, 306 and 308 and is through a spring 320 is pressed into the position shown. The way of working and the construction Inclusion will be described later. Overhaul module atorventil 320 on the left On the side of the idle brake valve 300 there is an overtaking modulator valve whose valve slide slides in the valve housing. The valve slide has control collars 322 and 324 and is pressed into the position shown by a spring 326.

This valve works as a pressure regulating valve and is supplied with pressure fluid via a branch line 327 of a line 328 from the selector valve 140. This pressure, which corresponds to the pressure in the main delivery line, acts on the end face of the valve slide 320 next to the control collar 324 and presses the valve slide 320 to the left against the force of the spring 326 until the control collar 324 opens an outlet line 330. The valve port to outlet conduit 330 is also connected to conduit 332 which is connected to the end of valve 320 containing spring 326. This pressure assists the spring 326 to return the valve slide to a position in which the supply to the lines 330 and 332 is blocked by the control collar 324 and these lines are relieved through an outlet 334, whereby the pressure is reduced sufficiently so that the Valve 320 can open again. This game is repeated so that the overtaking modulator valve oscillates between the open and closed positions in order to apply a pressure to line 330 which is somewhat less than the pressure in line 328. The purpose of this reduced pressure in line 330 will be explained. Clutch valve from second to first gear 350 A clutch valve from second to first gear 350 (FIG. 2 b, bottom) has a valve slide with control collars 352 and 354. The valve slide is pressed by a spring 356 into the position shown. The mode of operation of this valve will also be explained later. Downshift valve from second to first gear 370 Next to clutch valve 350 is a downshift valve from second to first gear 370, the valve slide of which slides in one end of a valve bore. A second valve slide 372 of larger diameter slides in the same bore and is pressed to the left by a spring 374 and to the right by a spring 376. The spring 376 lies between the valve slides 370 and 372. The operation of this valve will follow. Clutch signal valve 390 A clutch signal valve 390 (FIG. 2 f, center) has a valve slide with control collars 392, 394, 396 and 398. It is pressed into the position shown by a spring 400. TV valve 410 30 for shifting from third to second gear To the left of the clutch signal valve 390, a TV valve slide 410 for shifting from third to second gear is slidably arranged in a bore of the valve housing. It has a control collar 412 and a control collar 414 of smaller diameter. The right end of the valve slide is acted on by the pump pressure, which is supplied via a branch line 418 from the main delivery line 108, while the left end is acted on by the TV pressure, which comes via a branch line 416 from the TV line 236. In the position shown, an outlet line 420 is connected to an outlet 422 . However, if the TV pressure from the line 416 reaches a certain value, for example 4.93 kg / cm2 at a pressure of 7.04 kg / cm2 in the line 418, the valve slide 410 is switched off to the right until the control collar 412 the Outlet 422 blocks and connects TV line 416 to line 420. The pressures in the lines 416 and 420 then become the same until this connection is interrupted, namely when the pump pressure from the line 418 predominates again and the valve slide 410 is switched over again. The pressure in line 420 is used to obtain a downshift with the engine throttle partially open, as will be explained. Clutch filling valve 440 Above and next to the pressure regulating valve 110 (FIG. 2 d), a clutch filling valve 440 is provided, the valve slide of which has two control collars 442 and 444 and is pressed to the right by a spring 446.

Shaking valve 460 A shaking valve 460 (FIG. 2 e) (shaking between first and second gear) has a valve slide with control collars 464 and 466, which is pressed into the position shown by a spring 462.

G-3 valve 480 A G-3 valve 480 (FIG. 2e) is arranged to the left of the shaking valve 460. Its valve slide has control collars 482 and 484 and is pressed to the right by a spring 486. The left end of the valve spool 480 is acted on by the G-1 pressure, which is supplied via a branch line 488 from the line 254 , so that it moves it to the right. As a result, the control collar 482 exposes a line 489 which is connected to a branch line 490 of the main delivery line 108. Pump pressure can thus get into the space between the control collars 482 and 484 and, since the control collar 484 has a larger diameter than the control collar 482, the valve slide is switched back to the left. The control collar 482 closes the line 489, while the control collar 484 releases a line 494 which is open to the outlet when the G-3 valve is regulated. The pressure allocated to a line 496 is thus reduced to a value which allows the valve slide 460 to open the line 489 again. This regulation takes place continuously and the pressure allocated to line 496 will be greater than the G-1 pressure by a certain value, but less than the pump pressure from line 489.

In the absence of the G-1 pressure in the line 488, the G-3 valve will regulate to a pressure which is determined solely by the force of the spring 486. Even if the line 494 is no longer connected to the outlet, but receives pressure, as occurs at certain times during operation, this pressure is passed via a connecting line 498 to the right-hand side of the valve slide 480 and interrupts the control. Overdrive Transmission Valve 510 An overdrive transmission valve 510 has a valve slide which is in the form shown in FIG. 2 a drawn position is pressed by a spring 512. The valve slide has control collars 514, 516 and 518. Its effect, which is still to be described, is roughly a relay valve for controlling the overdrive planetary gear transmission 52. Overdrive brake accumulator 530 An overdrive brake accumulator 530 (FIG. 2a) has an offset bore in a housing 532; in which an accumulator piston 534 slides. A spring 53e pushes the piston 534 into the position shown in which the memory is empty. In addition to the end face of the piston 534, a branch line 538 of a line 540 is connected to the housing 532, which is connected to the overdrive transmission valve 510 and an overdrive brake servo 62 '. The accumulator piston 534 is also exposed to the TV pressure, which is fed via a branch line 542 to the TV pressure line # 236 and acts on different sizes (areas of the piston 534 and cooperates with the spring: 536 to counteract the force as a result of the piston of the pressure in the branch line 53. The purpose of the memory 530 is to delay the application and release of the overdrive brake 62, taking into account the engine output indicated by the TV pressure to obtain smooth gear changes, because pressure fluid flows from the branch line 538 into the accumulator housing 532 and pushes the piston 532 upwards until a volume of liquid has flown into the accumulator that depends on the dimensions of the accumulator, the TV pressure and the spring force applied to The pressure in the line 540 therefore falls until the pressure in this line builds up sufficiently can be used to counteract this influx to storage. When the engine is at full load, e.g. B. when switching with the engine throttle open, the TV pressure will be highest and counteract the movement of the piston 534, so that the pressure drop in the line 540 is much lower, so that the overdrive brake 62 is applied faster and no longer interruption of the Drive occurs.

When venting, the accumulator 530 will run faster at a high T-V pressure empty. The accumulator 530 then briefly supplies pressure fluid to the overdrive brake servo 62 ', whereby the release of the overdrive brake 62 is delayed.

Clutch Delay Valve 550 A clutch delay valve 550 has a relatively large diameter spool with three control collars 552, 554 and 556. This valve controls the actuation of the direct drive clutch 64 by exerting a memory effect which is dependent on the torque demand on the engine. For this purpose, a branch line 558 of the TV pressure line 236 is connected to the left side of the valve 550, which contains a throttle point 560 to briefly lower the incoming TV pressure so that the engagement of the clutch 64 is only ended after the one-way lock 66 is closed Effect has come, especially with reduced engine throttle openings. The right end of the valve 550 is connected to the overdrive transmission valve 1510 via a line 562. If this valve is in the correct position, the pump pressure is fed to the delay valve 550 via the line 562 in order to move it to the left into the position shown. The control collars 552 and 554 connect a line 564 to the clutch servo 64 'with an outlet 566, so that the servo 64' is relieved and the clutch 64 is disengaged.

Movement of the delay valve spool 550 to the left acts the T-V pressure is opposite and therefore at high T-V pressure, i.e. full load of the engine, the advancement of the valve slide 550 to the left is slower than at low T-V pressure and low torque demand on the engine. With the smallest T-V pressure, that is, zero opening of the engine throttle, the valve 550 of the clutch servo 64 'becomes fast Supply hydraulic fluid so that the two-way drive clutch 64 is engaged is, whereby an overtaking braking by the overdrive planetary gear transmission 52 is achieved. Because the T-V pressure is on the left side of the valve on this movement must be overcome, the throttle point 560 continues to play a role again, since at that time it curbs the outflow of liquid with T-V pressure, thereby the control stability of the valve 550 is increased. Only if the tax collar 556 of the Valve 550, which exposes line 564, pressure fluid is supplied to the clutch servo 64 'and causes clutch 64 to engage.

The speed of engagement of clutch 64 is thus determined by the TV pressure. A high TV pressure will delay engagement of clutch 64 with increased engine torque and ensure that overdrive brake 62 has been released. The disengagement of the clutch 64 is initiated when the hydraulic fluid supply from the line 562 is shut off by the overdrive transmission valve 510. Disengagement is similarly retarded by the TV pressure so that the delay valve 550 returns more quickly to the illustrated downshift position at a higher TV pressure. Manual valve 578 for the overdrive planetary gearbox A manual valve 578 for the overdrive planetary gearbox is assigned to the overdrive gearbox valve 1510 (Fig. 2a). This has a relay 580 with an excitation coil 581 and an armature 582 which can be moved about a pivot point 584 and which is held in the de-energized position by a spring 586. As with the check valve relay 186, a valve stem 588, which has a tapered head 590, is attached to the end of the armature 582. In the position shown, the head 590 interrupts the connection between the branch line 490 of the main delivery line 108 and a line 292 which leads to the right end of the overdrive transmission valve 510, so that the line 592 around the valve stem 588 is emptied via an outlet 594. The relay 580, which is grounded 596, is connected to the vehicle battery 192 by a conductor 597. In the conductor 597, a manual switch 598, which is within easy reach of the driver, and a conventional pressure switch 600, which is connected to the control device via a line 602, are provided. When the fluid in line 602 reaches a certain pressure, pressure switch 600 is closed, and assuming that manual switch 598 is also closed, the circuit from battery 192 to relay 580 is made and the relay 580 is energized. The armature 582 is then pulled downwardly and reverses the valve stem 588 so that the head 590 closes the outlet 594 and connects the line pressure branch 490 and the line 592. Trim valve 620 Below the TV valve 220 in FIG. 2 c, a trim valve 620 is provided, the valve slide of which has control collars 622, 624 and 626 and a central bore 630 at the right end. A spring 628 seated in the bore 630 presses against a control piston 632 which slides in the same bore as the valve slide. The control piston 632 has a relatively thin pin 634 which slides in the bore 630 of the trim valve slide 620 and carries a cross pin 636 in a slot which limits the path of the control piston 632 to the left. The control piston 632 itself has the same diameter as the control collar 626 of the valve slide 620, the control collars 622 and 624 of which have a slightly larger diameter. Two branch lines 640 and 642 connected to the TV line 236 come from the TV valve 220. The branch line 640 is controlled by the control connections 624 and 626, while the branch line 642 opens on the right side of the control piston 632. A branch line 644 of the main conveyor line 108 is controlled by the control connections 622 and 624.

The trim valve 620 regulates the network pressure from the line 644 as a function of the TV pressure and supplies a modulated TV pressure to a line 646. During regulation, the trim valve control collar 622 oscillates between a position in which hydraulic fluid from the line 644 is fed to the line 646 , and a position in which modulated TV pressure flows out of the line 646 via an extension 648 of the line 646 around the control collar 622 to an outlet 650 .

Clutch accumulator 660 The modulated TV pressure is conducted from the trim valve 620 through the line 646 to a clutch accumulator 660 for the second gear (FIG. 2 c). This has in a housing 662 an accumulator piston 664 which slides in a bore and is pressed into the position shown by a spring 666. In addition to the lower end face of the piston 664, a line 658 is connected, which leads to a clutch servo 50 ' .

The memory 660 operates in a similar manner to the memory 530, by having the engagement of the clutch 50 for the second gear depending on the Controls engine torque as indicated by the modulated T-V pressure. The T-V pressure, which is relatively little modulated when the engine torque is low, becomes allow the hydraulic fluid from line 658 to move piston 664 upward, to fill the space that has become free. This storage lowers the pressure in the pipe 658 for the time it takes to build up the pressure to full engagement the clutch is required. This results in a period in which the clutch 50 is gradually indented softly. With increasing torque demand of the engine the modulated T-V pressure increases and the displacement of piston 664 decreases, since the spring 666 is assisted by the modulated T-V pressure and the pressure drop decreases as a result of the storage. The clutch 50 is therefore engaged more quickly, to compensate for the stronger torque.

Switching valve 680 from first gear to first intermediate gear A switching valve 680 from first gear to first intermediate gear (Fig. 2e) has a stepped down Bore a valve spool with a control collar 682 of large diameter, a Control collar 684 of medium diameter and two control collars 686 and 688 smaller Diameter. A spring is located between the control collar 682 and a control piston 692 690 arranged, which presses both parts apart. Next to the tax collar 688 lies a control piston 694 with a control collar 696 larger and a control collar 698 smaller Diameter. The operation will be described later.

Switching valve 710 from first to second gear A switching valve 710 from first to second gear (Fig. 2 f) has a valve slide with a control collar 712 of large diameter, a control collar 714 of medium diameter and a control collar 716 of slightly smaller diameter in a stepped bore. In addition to the control collar 716, a control piston 718 is slidably provided in the bore, which is pressed against the valve slide 710 by a spring 720. The control piston 718 has control collars 722, 724, 726 and 728. On the other side of the valve slide 710 is a control piston 730, which has a control collar 732 of small and a control collar 734 of larger diameter and is loaded to the right by a spring 736, which is on the valve slide 710 and the small control collar 732. Switching valve 750 from second to third gear A switching valve 750 from second to third gear ( Fig. 2b) has a valve slide with a control collar 752 of large diameter, a control collar 754 of medium diameter and two control collars 756 and 758 of small diameter in a remote valve bore. On the left side of the valve slide there is a control piston 760 with a relatively long control collar 762, which has annular grooves on the circumference to reduce friction. On the other side of the valve slide 750 is a control piston 764 with a control collar 766 of large and a control collar 768 of small diameter. The control piston 764 and the valve slide 750 are pushed away from one another by a spring 770. Switching valve 780 from third to fourth gear A switching valve 780 from third to fourth gear (Fig. 2e) has a valve slide with a control collar 782 of large diameter, a control collar 784 of medium diameter and two control collars 786 and 788 of small diameter in a remote valve bore . On the right side of the valve slide 780 there is a control piston 790 with control collars 792 and 794. The two parts are pushed away from one another by a spring 796. Operation of the control device The operation of the hydraulic control device to achieve the various drive conditions of the transmission will now be described. Park and Idle The selector valve 140 must be moved to the P or N position prior to closing the starter circuit and starting the engine. In the position P, a linkage connected to the selector valve 140 will cause a pawl, not shown, to engage ratchet teeth associated with the output shaft 12, so that rotation of this shaft and movement of the vehicle is prevented. After the engine has been started, the pump 100 begins to deliver pressure fluid into the main delivery line 108, in which the pressure is determined by the pressure regulating valve 110. When the selector valve 140 is set to P or N, the control collar f 46 connects the lines 174, 324 and 819 for the range, middle drive range and low drive range with the outlet at the free end of the valve bore and the main delivery line 108 between the control collars 144 and 146 with the line 180 leading to the shut-off valve 160. The relay 186 of the shut-off valve is de-energized at this time, so that this valve is in the upward switching position shown.

In the extreme left position of the selector valve 140 (position P) is the line 218 supplying the T-V valve 220 via the outlet at the free end of the Valve bore also relieved. 13e! Adjust in the position N against it the main delivery line 108 and the line 218 to the T-V valve 220 are connected to one another. When idling, the T-V valve 220 performs its normal function, a T-V pressure in line 236 which takes into account engine torque and outside air pressure. In this position of the selector valve 140, however, the value of the T-V pressure is of no importance.

When the coupling signal valve 390 is in the position shown, network pressure is fed from the line 108 via the branch line 418 to a branch line 311 which flows into a line 812 between the control strips 396 and 398 of the coupling signal valve. A branch line 814 of the line 812 leads to the right side of the coupling filling valve 440 and the fluid pressure from this line will move the valve slide 440 to the left against the spring 446 until the control collars 442 and 444 the connection between a two-line 816 of the main delivery line 108 and a line 818 leading to the hydrodynamic coupling 44. The filling of the hydrodynamic coupling 44 begins at the time when the line 812 leads pressure fluid via a branch line 820 to the right side of the coupling valve 350 from second to first gear, which with the help of spring 356 moves the valve slide into its left end position against the pump pressure moved, which is supplied via the lines 108 and 490 and a branch line 822 leading to the other side of the valve slide 350 next to the control collar 352. The line 490 has a branch line 824 which conducts pressure fluid between the control collars 352 and 354 to a line 828 which leads to the clutch filling line 818. The hydrodynamic clutch 44 thus receives pressure fluid from the clutch filling valve 1440 and from the clutch valve 350 from second to first gear.

The clutch fill valve 1440 also acts as a relief valve. If, when filling the hydrodynamic coupling 44, the pressure in the main delivery line 1.08 and thus in the branch line 814 falls below a certain value, the valve 440 closes and interrupts the supply of pressure fluid to the hydrodynamic coupling 44 until the network pressure builds up again. This ensures that the filling of the hydrodynamic coupling 44 does not cause the network pressure to drop to a dangerously low value.

The clutch signal line 812 leads to one or more drain valves 830 which rotate with the pump wheel 46 of the hydrodynamic clutch. Each of these valves, which can be displaced in an offset bore, has a control collar 832 of large and a control collar 834 of smaller diameter. A spring 836 pushes the valve into the upper position, which is connected to the working chamber of the hydrodynamic coupling 44, the pressure fluid flowing through a channel 838 between the control collars 832 and 834 to an outlet 840. The dimensions of the valve 830 are chosen so that the combined effect of the centrifugal force as a result of the pressure of the pump wheel 46 and the force of the spring 836 brings the valve upwards into the open position. In order to bring it into the closed position, the pressure fluid supplied via the line 812 acts on the larger control collar 832 and presses the valve 830 downwards, so that the control collar 832 interrupts the connection between the channel 838 and the outlet 840.

In the positions N and P of the selector valve 140, the controller 250 supplied with network pressure. But since the vehicle is stationary, the controller does not turn and neither G-1 print nor G-2 print is developed.

If a G-1 pressure is established, it is passed through branch line 252 to line 254 and thus to a branch line 842 (FIG. 2 f), which leads to a reverse gear locking piston 844 leads, which slides in a housing 845 and at one end an open slot 846 has. The slot 846 works with a transverse pin 848 seated in the housing 845, which limits the movement of the locking piston 844 to the right. On the cross pin 848 a spring 850 acts, which presses the locking piston 844 into the position shown. Of the Locking piston 844 is activated by the G-1 pressure at a low driving speed, e.g. B. about 11.3 to 12.9 km / h, whereupon the grooved end 852 of the reverse gear piston engages in the linkage, not shown, of the selector valve 140 and its adjustment prevented in the reverse gear position. This protects the transmission from damage, in the event that the driver accidentally overrides the selector valve 140 at vehicle speeds Wanted to adjust 11.3 to 12.9 km / h to reverse gear.

The regulator line 254 also has a branch line 854 that is G-1 pressure between the control collars 712 and 714 of the switching valve 710 from the first to the second Gang heads, and also another branch line 856, through which G-1 pressure is applied to the reaches the left side of the control piston 718 of the switchover valve 710.

A branch line 858 routes G-1 pressure between the control collars 752 and 754 of the switching valve 750 from second to third gear. G-1 pressure also comes via the line 254 to the left side of the control piston 694 of the switching valve 680 from first aisle to @ -n first intermediate aisle and via branch line 488 the left side of the G-3 valve 480. The G-3 valve 480 begins in correspondence to regulate with the G-1 pressure, as explained above, since the valve 480 with Liquid is supplied from line 489 under pump pressure. Lines 494 and 498 from G-3 valve 480 are in communication with lines 859 and 860, whose the latter between the control collars 784 and 786 of the switching valve 780 of the third is connected to an outlet 861 for fourth gear. The administration 490 from the main conveyor line 108 leads to the overdrive transmission valve 1578, where the Fluid flow through valve stem 588 is blocked because relay 580 is de-energized is. A branch line 862 of line 490 goes to the overdrive transmission valve 580, where it is controlled by the control collar 518. The line is in the position shown 862 blocked by the valve slide 510. There is between the control bonds 514 and 516 a connection between branch line 862 and line 562 to the clutch delay valve 550. The hydraulic fluid from line 562 becomes the clutch delay valve 1550 toggle to the left until the connection to line 564 is established, whereupon the clutch 64 is engaged for direct drive by the associated servo 64 ' will. From the above it follows that when the selector valve 140 is in position in the layers P or N the hydrodynamic coupling 44 is filled and the coupling 64 for direct drive are engaged while the remaining brakes and clutches are released are. The idle exists because the idle brake 38 remains released, so that none There is support in the planetary gears 16 and 18 and from the input shaft 10 no torque can be transmitted to the intermediate shaft 29. The overdrive planetary gear transmission 52 can therefore be shifted to direct drive before shifting to first gear without affecting the idle.

If the vehicle is to be propelled forward, the selector valve 140 can be moved to position D, I or L as desired. Drive Range Moving the selector valve 140 to position D brings the control collar 146 straight to the right side of the opening connected to the line 174, so that the connection between the main delivery line 108 and the line 174 is established. As with idle, pressurized fluid is directed through line 180 to check valve 160 and through line 218 to TV valve 220 .

From the line 174 pressure fluid is conducted via a branch line 864 to the idle brake valve 300, where it acts on the differently sized surfaces of the control collars 302 and 304, so that the valve 300 is switched to the right against the force of the spring 310, so that the control collar 304 a secondary branch line 866 closes off and the pressure fluid must flow through an opening 867 into a spring leaf 868 before it reaches the idle brake servo 38 'via a line 870 in order to apply the idle brake 38. The pressure fluid from the line 879 acts via a branch line 872 also on the surfaces of the control collars 306 and 308 of different sizes and increases the force acting on the valve 300 to the right.

In the manner described, the pressure fluid is fed to the line 870 at the lowest possible speed, so that the idle brake 38 is applied gradually and does not produce any harshness that is noticeable to the driver. This is particularly important since the reaction ring gear 34 of the rear planetary gear train 18 is rotated backwards quickly and takes the one-way lock 36 and the free part of the idle brake 38 with it. It is therefore advantageous to first delay this reverse rotation and then to stop it before the idle brake 38 is applied. The speed of application changes with the intake pressure of the engine, since a branch line 875 of the TV line 236 is routed to the right-hand side of the idle brake valve 300. If the accelerator pedal 196 is depressed significantly for a quick start, the TV pressure increases as the engine torque increases and forces the valve 300 to the left to connect the branch line 866 to a branch line 874 of line 870. Pressure fluid then flows to line 870 both via opening 867 and via branch line 874, so that the idle brake 38 is applied more quickly. The speed of application increases with increasing motor torque.

Pressure fluid is also fed from line 174 via a branch line 876 to the switching valve 750 from the second to the third gear, but where the further path is blocked by the control collar 754. The other switching valves are also ineffective, since a branch line 878 to the switching valve 710 from the first to the second gear through the control collar 714, a branch line 880 to the switching valve 780 from the third to the fourth gear through the control collar 784 and a branch line 882 to the switching valve 680 from the first gear to the first intermediate gear are blocked by the control collar 684.

When the machine is idling, the resistors are at the starting point 12 is sufficient to generate a torque transmitted by the hydrodynamic coupling 44 to be overcome, and the slip in the hydrodynamic coupling 44 will be sufficient to prevent the vehicle from crawling. First gear with the idle brake applied 38 is the transmission in first gear for forward travel, i.e. i.e., the front planetary gear train 16 is ineffective, the rear planetary gear transmission 18 is on reduced drive and the overdrive planetary gear transmission 52 switched to direct drive.

If the engine throttle is opened in order to initiate the start-up of the vehicle, the pressure in the engine intake line acts and the TV valve 220 acts in the manner described to supply TV pressure to each of the switching valves via line 236.

The line 236 has a branch line 884 to the switching valve 680 from first course to first intermediate course. Because this valve is in the downshift position control collars 688 and 686 connect branch line 884 to a line 886, which leads to the right end face of the control piston 692, i.e. the one with T-V pressure is applied.

The switching valve 710 from first to second gear allows flow from a branch line 888 of the TV pressure line 236 between the control collars 722 and 724 of the control piston 718 to a line 890 which leads to the right side of the control piston 730. If the TV pressure reaches a certain value, it will cause the control piston 730 to start regulating the ° TV pressure in order to create a modulated TV pressure via a line 891 in the spring chamber between the switching valve 70 from first to second gear and the control piston 730 to be supplied. This control begins when the line 891 from the control collar 734 of the control piston 730 is released. The pressure fluid will then tend to move the control piston 730 between positions in which the line 891 is connected to or separated from an outlet line 892.

The outlet line 892 serving to remove excess fluid leads from the regulator piston 730 to the bore of the switching valve 710 from the first to the second gear between the control collars 724 and 726 of the regulating piston 718, between which a line 894 leads to the check valve 160. In the illustrated position of the shut-off valve 160, the line 894 between the control collars 164 and 166 is connected to an outlet 896.

The control piston 764 of the switching valve 750 from second to third gear works in a similar way to the control piston 730. Its right side is acted upon by the TV pressure, which is supplied from the line 236 via intermediate lines 875 and 900, between the control collars 756 and 758 of the switching valve 750 from second to third gear and a line 902 is fed. If the TV pressure is sufficient to overcome the force of the spring 770 and to switch the control piston 764 to the left, a line 904 to the spring chamber between the changeover valve 750 and the control piston 764 is opened by the control collar 766. The modulated fluid pressure then causes the control piston 764 in the closed position and 904 opens the line to relieve a leading to the check valve 160 line 906. At position of the check valve 160 in the upshift position, the line 906 between the control collars 168 and 170 of the check valve 160 having a Branch line 908 connected to line 328 for the middle drive range, so that this line 328 is relieved via the bore of the selector valve 140. This ensures the required relief of the regulating piston 764 so that it can regulate in the desired manner.

The switching valve 780 from third to fourth gear is always supplied with TV pressure via a branch line 910 of the line 326 , which leads to the right side of the control piston 790. The control piston 790 is pressed in the same way as the control piston 730 and 764 by the TV pressure to the left against the force of the spring 796 until a line 914 is opened in order to conduct pressure fluid into the spring chamber between the valve slide 780 and the control piston 790. The pressure in the spring chamber will then hold back the control piston 790 to the right until the pressure is diverted through an opening connected to the line 328 which, as mentioned, is relieved via the outlet of the selector valve 140 when this is in position D.

As the vehicle speed increases, the G-1 pressure and the G-2 pressure increase, with the G-2 pressure increasing more slowly than the G-1 pressure. The G-2 pressure is routed via line 256 to the left side of the control piston 760 of the switching valve from second to third gear and via a branch line 916 between control collars 782 and 784 of switching valve 780 from third to fourth gear, to their different sizes Surfaces he acts. At this time, the G-2 pressure is insufficient to switch the switch valve 750 from second to third gear or the switch valve 780 from third to fourth gear.

As the G-1 pressure increases, the G-3 pressure formed in the G-3 valve 480 and supplied to the switching valve 680 from the first gear to the first intermediate gear via the line 496 is gradually built up. As long as a certain driving speed is not reached, however, the switching valve 680 remains from the first gear to the first intermediate gear and the other switching valves in the downshift position and the transmission works in the first gear. Switching from first gear to first intermediate gear As the vehicle speed increases, the output shaft 12 can run fast enough to increase the G-1 pressure acting on the G-3 valve 480 so that a sufficiently high G-3 pressure is created to move the switching valve 680 from first gear to first intermediate gear to the right in the upshift position. Since the G-1 pressure also acts on the left side of the control piston 694, the G-1 pressure and the G-3 pressure both push the switching valve 680 against the forces of the TV pressure and the spring 690 into the upshift position. If the engine torque is too high, as indicated by the level of the TV pressure in the line 886, the changeover is delayed so that the first gear can be fully used for rapid acceleration.

When switching on the switching valve 680 from first gear to first The branch line 882 of the line 174 between the control conduits becomes an intermediate passage 684 and 686 connected to a line 918 which leads to the shaking valve 460, which is in the position shown. Line 918 is therefore between the control connections 464 and 466 connected to a line 920, which on the left Side of the overdrive transmission valve 510 leads.

In the line 920 there is network or pump pressure, which overcomes the resistance of the spring 512 and the switching valve 520 switches to the right, so that between the control collars 514 and 516 an outlet 922 is connected to the line 562, which is on the right side of the overdrive clutch Delay valve 550 leads. The pressure in the line 562 is thus reduced and the TV pressure acting on the other side of the valve 550 can move it to the right, so that the outlet 566 between the control collars 552 and 556 is connected to the line 564. The servo 64 'is relieved and the clutch 64 for direct drive is thereby disengaged. Meanwhile, a branch line 924, which is supplied from the main delivery line 108 via the branch lines 862 and 490, is connected to the line 540 leading to the overdrive brake servo 62 'between the control collars 516 and 518 of the overdrive transmission valve 510. A throttle point 916 in the branch line 924 delays the flow of pressure fluid to the line 540. In conjunction with the storage effect of the brake accumulator 530 , this results in a smooth application of the overdrive brake 62. The storage effect is, as already explained, controlled by the TV pressure, so that the Engine torque determines the speed at which the overdrive brake 62 is applied. This is necessary because once the switch is initiated, the torque should determine how quickly the application occurs. If the application is too slow, the motor will run away; if this happens too quickly, a shock is felt. Overdrive transmission valve 510 begins to move to the right to initiate clutch 64 disengagement before hydraulic fluid is applied to overdrive brake servo 62 '.

When the brake servo 62 'is applied and the clutch servo is relieved 64 ', the overdrive brake 62 is applied and the clutch 64 is disengaged, so that the overdrive transmission 52 operates in overdrive. The front and rear planetary gears 16 and 18 are still shifted as in first gear, whereby the first intermediate gear is made.

Switching from the first intermediate gear to the second gear If the driving speed has increased further, under the combined effect of the G-1 pressure which is applied to one end of the control piston 718 of the switching valve 710 from the first to the second gear via the branch line 856 of the line 254 acts, and the pressure which acts on the different sized control collars 712 and 714 of the switching valve 710 via the branch line 854, the entire switching valve 710 moves to the right. Then the control collar 722 of the control piston 718 interrupts the transmission of the TV pressure from the branch line 888 to the line 890, and the control collars 714 and 716 of the valve slide 710 connect the branch line 878 of the line 174 for the drive range with a branch line 928 of the line 658 then pump pressure fed to accumulator 660 and servo 50 '. A restriction 930 in branch line 878 delays engagement of clutch 50. Accumulator 660 also controls the rate of engagement of clutch 50, as previously described. At this moment the trim valve 620 modulates the TV pressure and the modulated pressure is fed to the accumulator 660 via the line 646 and assists the spring 666 in holding the piston 664 in its lowest position. The pressure fluid in the line 858 moves the piston 664 in accordance with the opposing forces, and the filling of the space that becomes free causes a pressure drop in the line 658. The size of this pressure drop is determined by the TV pressure, which depends on the engine torque, so that, As already explained, the clutch 50 is engaged slowly when the torque is low and quickly when the torque is high, as soon as the switching process is initiated.

Pressure fluid from line 658 also passes through branch line 932 to the left side of clutch signal valve 390, which is moved to the right against the force of spring 400. The control collars 394 and 396 then connect the coupling signal line 812 to an outlet 934, while the branch line 811 of the line 418 between the control collars 398 and 396 is connected to a line 936. The pump pressure is passed via this line 936 to the left side of the clutch filling valve 440, which assists the spring 446 in order to switch this valve into the position shown. Since the fluid pressure, which existed in the line 812 and held the outlet valve 830 in the closed position, is then relieved, the outlet valve 830 is moved upward into the open position by the spring 836 and the centrifugal force as a result of the rotation of the clutch pump wheel 46. The liquid begins to flow out of the hydrodynamic coupling 44 through the channels 838 and 840. This outflow is assisted by the clutch valve 350 from second to first gear, since its right side is relieved of the pressure from the branch line 820 of the line 812. The network pressure from branch line 822 therefore switches the valve to the right so that branch lines 826 and 828 of clutch fill line 828 are connected to an outlet 938. The outlet 938 is above the level of the sump; when the hydrodynamic coupling 44 is emptied, it prevents the formation of a partial vacuum which could occur if the emptying was rapid. When the liquid flows out through the valve or valves 830, it is replaced by air flowing in via the outlet 938. The supply to the hydrodynamic clutch is then shut off by the clutch filling valve 1440 and the clutch valve 350 from second to first gear, while the fluid flows out of the hydrodynamic clutch 44 via the valve or valves 830. The effectiveness of the hydrodynamic coupling is therefore quickly reduced when the coupling 50 begins to take over the drive.

Line 936 also leads to the left side of shaker valve 460, and the pressure from this line moves the valve into the right end position, so that control collar 466 closes line 918 and lines 920 and 859 are connected between control collars 464 and 466 . The line 859 is relieved at this time via the line 860 between the control collars 784 and 786 of the switching valve 780 from third to fourth gear to outlet 861. When the pressure in line 920 is relieved, the overdrive gearbox valve 1510 is switched back to the position shown so that pressure fluid flows back into line 562, which then flows through clutch delay valve 550 to line 564 in order to act on clutch servo 64 'that controls clutch 64 for direct drive engages again.

At the same time, the line 540 becomes the overdrive brake servo 62 ' connected to the outlet 922 in the bore of the overdrive transmission valve 510, so that the overdrive brake 62 is released. Since the clutch signal valve 390 was actuated by the hydraulic fluid flowing to the clutch servo 50 ', the clutch 50 is engaged by the direct drive clutch 64. Otherwise a switch-off from the first intermediate gear to the first gear would be able to take place.

The front planetary gearing 16 then cooperates in the transmission Reduction and the overdrive planetary gear 52 in direct drive while the rear planetary gear 18 ineffective and the hydrodynamic clutch 44 is empty. The gear ratio thus corresponds to that of the front planetary gear 16. Switching from second to third gear The driving speed increases continues on, the G-1 pressure and the G-2 pressure supplied from the regulator 250 become large enough to cause a shift from second to third gear.

The GA pressure from line 254 and its branch line 858 acts on the different sized control collars 752 and 754 of the switching valve 750 from second to third gear and the G-2 pressure from line 256 on the left side of the control piston 760, so that the entire switching valve 750 is switched to the right in the upward switching position against the combined effect of the TV pressure and the spring 770 on the control collar 752 of the valve. In this position, the connection between the TV branch line 900 and the line 902 is interrupted by the control collar 758, so that the action of the TV pressure on the control piston 764 ceases. Branch line 876 of line 174 is connected to outlet line 602 between control collars 754 and 756. A branch line 940 of line 602 leads to the right side of clutch signal valve 390 and the pressurized fluid moves valve 390 to the left to expose line 936 through control collar 398. The fluid then flows to the left side of the coupling valve 440. When the coupling signal valve 390 is moved to the left, the branch lines 811 and 418 of the main delivery line 108 are reconnected to the coupling signal line 812 and the pressure fluid reaches the right side of the line 812 via the branch line 814 Clutch filling valve 44 (1. The combined effect of the network pressure and the spring 446 hold the clutch filling valve 1440 in the position shown, so that the clutch filling line 818 is not connected to the branch line 816 of the main delivery line 108. In addition, the fluid pressure from the line 936, although it is above another way, the switch valve 1460 in the right position as in the second Gana so that the overdrive gear valve 510 is not moved and the direct drive clutch 64 remains engaged of the exhaust valve 830, so that the channels 838 and 840 are blocked by the hydrodynamic coupling 44. The pressure fluid from the line 812 can also flow via the branch line 820 and moves the clutch valve 350 from second to first gear back into the position shown in which the network pressure from the branch lines 490 and 824 of the main delivery line 108 between the control collars 352 and 354 of the valve 350 to the branch lines 826 and 828 of the coupling filling line 818 to this and into the hydrodynamic coupling 44. Since the hydrodynamic clutch 44 is filled from second to first gear solely by the clutch valve 1350, the rate of filling is necessarily slower than when the clutch filling valve 1440 assists the filling. This results in a smooth gear change.

When the switching valve 750 is switched from second to third gear, pressure fluid is passed via line 602 to pressure switch 600, which is closed. The circuit assigned to the overdrive transmission valve 578 is then prepared to be able to be closed by actuating the manual switch 598, as will be described below.

In third gear, the hydrodynamic clutch 44 works, the clutch 50 is engaged and the clutch 64 remains engaged. The front planetary gear train 16, the rear planetary gear train 18 and the overdrive planetary gear train 52 are all switched to direct drive. Shifting from Third to Fourth Gear A further increase in the vehicle speed increases the G-2 pressure which is fed via branch line 916 of line 256 to the different-sized areas of control collars 782 and 784 of changeover valve 780 from third to fourth gear. If the resulting force is greater than the combined force of the modulated TV pressure and the spring 796, the switching valve 780 is switched on to the right. Between the control collars 784 and 786 of the valve 780, the branch line 880 of the line 174 and the line 860 are connected to one another, and since the shaker valve 460 is in the right position, the lines 859 and 920 are connected between its control collars 464 and 466 so that the hydraulic fluid from lines 860 and 859 is directed through line 920 to the left side of overdrive transmission valve 510. This valve 510 is then moved to the right, as occurs when switching from first gear to first intermediate gear, and relieves pressure on line 582 to outlet 922, while line 540 to overdrive brake servo 62 'receives hydraulic fluid from branch lines 862 and 490 of main delivery line 108. The memory 530 brings the speed of application of the overdrive brake 62 to match the TV pressure in the line 542, as has already been described.

After you put on the overdrive brake 62 and remained unchanged front and rear planetary gears 16 and 18, the gear is in overdrive, in which the output shaft 12 runs faster than the intermediate shaft 29.

Manual shift from fourth to third gear A downshift from fourth to third gear can be achieved or a shift from third to fourth gear can be prevented by simply operating the manual switch 598 will. With the manual switch 598 closed and at the same time by the fluid pressure from the line 602 closed pressure switch 600 is the excitation circuit for the Coil 581 is closed and the relay 580 picks up, whereby the end of the armature 582 moves downward and lifts valve stem 588 so that head 590 is the outlet 594 closes. It becomes the connection between line 592 and the branch line 490 of the main delivery line 108 and the supplied network pressure is with the spring 512 cooperate, the overdrive transmission valve 510 in the downshift position to move or to hold in it, depending on which position it was before.

Closing the manual switch 598 causes pump pressure to be supplied to the right side of the valve 510 which, together with the spring 512, is sufficient to hold the overdrive valve 510 in the direct drive position, regardless of whether the other side is through the line 920 applied pressure or not. If overdrive from third gear is desired, this can be achieved by opening the manual switch 598, provided that the switching valve 780 from third to fourth gear is in the upshift position. Manual shift from fourth to second gear In order to obtain a manually operated downshift from fourth to second gear, the selector valve 140 is shifted from position D to position 1 for the middle drive range. In this position of the selector valve 140, the main delivery line 108 and the line 328 are connected to one another between the control collars 144 and 146. The pressure fluid from the line 328 passes through an opening controlled by the control piston 790 of the switching valve 780 from third to fourth gear and then via the line 914 into the pocket for the spring 796 -2 pressure, so that the switching valve 780 is switched from third to fourth gear in the downshift position shown. The pressure fluid that was fed to the shaking valve 460 via lines 860 and 859 and further through line 920 to the left side of the overdrive transmission valve 510 is shut off by the control collar 784 of the switching valve 780 from third to fourth gear. By shutting off this pressure, the overdrive transmission valve 510 will return to the position shown, in which it causes the clutch 64 to be re-engaged and the overdrive brake 62 to be released.

The branch line 908 of the line 328 is also connected to the line 906 leading to the control piston 764 between the control collars 168 and 170 of the shut-off valve 160 when this is in the position shown. This pressure fluid from the line 906 is fed in the same way as that fed to the control piston 790 through the line 904 to the spring pocket for the spring 770 and causes the switching valve 750 to move from second to third gear into the downshift position. Its control collar 754 then interrupts the supply to the line 602, to open the pressure switch 600, and the supply to the branch line 940 of the line 602. By the shut off of the hydraulic fluid of the branch line 940, the clutch signal valve is moved 390 to the right, the line 812 and connects its branch lines 814 and 820 between control collars 394 and 396 to outlet 934. The hydrodynamic clutch 44 is then emptied both through the clutch valve 350 from second to first gear and the outlet valve or valves 830.

If the clutch signal valve 390 is switched to the right, the line 811 between the control collars 396 and 398 is connected to the line 936, so that the pressure fluid previously supplied through the line 940 is still fed to the clutch filling valve 440 and the shaking valve 460 in order to keep it in the Hold position for fourth gear. This is particularly important with respect to the shaker valve 460, which does not need to be moved when the line 920 is relieved from third to fourth gear via the downshifting switch valve 1780 to allow the overdrive valve 510 to disengage the clutch 64. When the hydrodynamic clutch 44 is ineffective and the clutch 64 is re-engaged, the transmission is in second gear, with the front planetary gear transmission 16 determining the transmission ratio. Switching from fourth to second gear by means of the accelerator pedal In order to initiate switching off from fourth to second gear by means of the accelerator pedal, the driving speed must be below a certain maximum value, e.g. B. 104.6 km / h. Then, when the accelerator pedal 196 is depressed to a position where the engine throttle is substantially fully open, the switch 190 closes and completes the circuit from the battery 192 to the lock relay 186. The energized relay coil 187 causes the valve stem 202 to move below, so that the pressure fluid flows out of the control chamber 178 through the throttle point 184. The force of the pressure fluid in the control chamber 172 at the other end of the check valve 160 will overcome the force of the spring 162 and move the check valve 160 to the left so that a branch line 942 of the line 174 is connected to the line 906 between its control collars 168 and 170. The pressure fluid from the line 906 is fed to the control piston 764 of the switching valve 750 from second to third gear, so that this is shifted downwards. When the valve 750 is switched down, the hydrodynamic clutch 44 is emptied, as already described for the manual shift from fourth to second gear. Likewise, the operation of the clutch signal valve 390, the clutch fill valve 440 and the shaking valve 460 is the same as in the second gear.

In order to complete the shift from fourth to second gear, the shift valve 780 must be shifted down from third to fourth gear to cut off the hydraulic fluid supply to the left side of the overdrive transmission valve 510 in the same manner as in the manual shift from fourth to second gear. The arrangement of the switching valve 780 from third to fourth gear is advantageously chosen so that downshifting from fourth to second gear by means of the accelerator pedal is only possible below a certain driving speed, e.g. 104.6 km / h, because the TV pressure continuously fed to the control piston 790 of the switching valve 780 from third to fourth gear has a maximum value when the accelerator pedal 196 is depressed and then a greater force than the opposite G-2 pressure is below 104.6 km / h travel speed. It should be noted that when the transmission is in fourth gear, the G-1 pressure and G-2 pressure decrease because the output shaft 12, and therefore the governor 250, are rotating at a reduced speed. The maximum TV pressure will therefore predominate and switch the switching valve 780 downwards. Switching from fourth gear to second intermediate gear using the accelerator pedal At driving speeds above 104.6 km / h and below slightly higher driving speeds, e.g. B. 128.7 km / h, the maximum TV pressure when the accelerator pedal is depressed is not sufficient to shift the switching valve 780 down from third to fourth gear. The overdrive transmission valve 510 will therefore remain in the fourth gear position since the overdrive brake 62 remains applied and the overdrive transmission 52 is running in overdrive. Under these conditions, a gear is obtained that lies between the second and third gear, precisely the second intermediate gear. In this case, the hydrodynamic clutch 44 is ineffective, the clutch 50 is engaged and the overdrive brake 62 is applied, so that the gear ratio is the product of the gear ratios of the front planetary gear train 16 and the overdrive planetary gear train 52.

The reason why a lower reduction is achieved when downshifting from fourth gear above 104.6 km / h than below this driving speed is that above 104.6 km / h rapid acceleration is not so void. Furthermore, switching off to a lower gear would result in heavy loads in the transmission and an excessive increase in the engine speed. Forced downshifting from fourth to third gear A forced downshifting from fourth to third gear can occur in a certain driving speed range, e.g. B. between 33.8 and 104.6 km / h, can be achieved without depressing the accelerator pedal 196 until the switch 190 is actuated. This is possible because the control piston 790 is constantly acted upon by the TV pressure, so that if the correct ratio between the G-2 pressure, which is slightly reduced in overdrive in fourth gear, and the TV pressure, which is almost the same when the engine torque is increased fully open engine throttle is developed, the switching valve 780 is shifted down from third to fourth gear. This releases the overdrive brake 62 and engages the clutch 64. Forced downshifts from fourth to second gear Below 104.6 km / h and above 33.8 km / h, a forced downshift from fourth to second gear can be achieved if the accelerator pedal 196 is depressed until just before the position in which the switch is pressed 190 is actuated. The TV pressure corresponding to the increased engine torque is then directed via line 236 and branch line 416 to the left side of valve 410, where it creates a force sufficient to counteract the opposing force of branch line 418 on main delivery line 108 smaller area of valve 410 directed pump pressure to overcome. The valve 410 is therefore moved to the right and the TV pressure is supplied via the line 420 to the switching valve 750 from second to third gear. Since this valve 750 is in the upshift position, the line 420 between the control collars 756 and 758 is connected to the line 907, which leads to the right side of the control piston 764. Therefore, the switching valve 750 is downshifted from the second to the third gear. The TV pressure is also sufficient to downshift the switching valve 780 from third to fourth gear in the manner already described for the forced downshift from fourth to third gear. After switching over the valves 750 and 780, the second gear is set, that is to say the hydrodynamic clutch 44 is emptied, the clutch 64 is engaged again and the clutch 50 has remained engaged. Forced downshifting from fourth gear to second intermediate gear. B. between 104.6 and 128.7 km / h, a forced downshift from fourth gear to second intermediate gear can be achieved by depressing the accelerator pedal 196, but without closing the switch 190. The switching valve 350 from second to third gear is switched downwards, as in the case of forced downshifting from fourth to second gear, in order to empty the hydrodynamic clutch 44. Since the TV pressure cannot overcome the G-2 pressure acting on the switching valve 780 from third to fourth gear above 104.6 km / h, this valve remains in the upshift position, so that the overdrive brake 62 remains applied and the second intermediate gear is switched on.

Shift down from third to second gear using the accelerator pedal If an upshift to fourth gear is within a certain vehicle speed range, z. B. 19.3 to 100 km / h, has not yet taken place, a downshift to the second Gear by depressing the accelerator pedal 196 until the switch is actuated 190 can be made. As a result, the switching valve is in the manner already described 750 downshifted from second to third gear by applying pressure fluid from Check valve 160 was fed to control piston 764 via line 906. The hydrodynamic Clutch 44 is emptied and second gear is obtained. Forced downshift from third to second gear This shift takes place in the same speed range from 19.3 to 100 km / h with third gear engaged in the same way. However, the switching is not made by depressing the accelerator pedal 196 initiated until the switch 190 closes. If the T-V pressure is in the line 236 is sufficient, he will move valve 410 to the right and T-V pressure will come to the right side of the control piston 764 via lines 420 and 902, which between the control collars 756 and 758 of the switching valve located in the upshift position 750 are connected from second to third gear. The switching valve 750 is therefore downshifted and the hydrodynamic coupling 44 deflated to get second gear.

Shifting from third to second gear The valve 410 allows a downshift from third to second gear with the accelerator pedal 196 only partially depressed. The engine torque at this engine throttle position must be so great that a TV pressure of 4.93 kg / cm2 is formed as he was already called, for example. Because of the different large areas of the valve 410 , this pressure of 4.93 kg / cm2 is sufficient to overcome the network pressure, so that the valve 410 is opened and this TV pressure via the line 420 to the switching valve 750 from second to third gear is heading. The switching valve 750 is then switched downwards, as already described, provided that the combined forces of the G-1 pressure and the G-2 pressure are less than that of the TV pressure. This enables the driver to achieve a forced downshift at relatively low driving speeds without having to depress the accelerator pedal 196 until the switch 190 closes. Middle drive range The selector valve 140 is moved to the right into position I for the middle drive range. In this setting, the switching valve 780 from third to fourth gear is prevented by its connection to line 328 from upshifting and the switching valve 750 from second to third gear is prevented by the fluid pressure coming from branch line 908 of line 328 through the check valve 160 and the line 906 is supplied, held in the downshift position. Since the pressure holding the changeover valve 750 is the same as the pump pressure, the changeover valve 750 will only shift up from second to third gear at a certain driving speed, which is, for example, 112.6 km / h.

In the middle drive range, the first gear, the gear change to the first intermediate gear and the gear change from the second intermediate gear to the second gear are achieved as in the drive range. In the second gear, however, the overtaking brake 42 is applied in the middle drive range, so that engine braking is possible, which is caused by the modulated fluid pressure from the overtaking modulator valve 320. The modulator valve 1320 receives fluid at pump pressure from the branch line 327 of the line 328 and provides a reduced or modulated pressure in the line 330. Since the torque transmitted in second gear from the overrunning brake 42 is low, there is less pressure and therefore a smooth application of the overrunning brake 42 in the middle drive range. However, if the engine is driving, the one-way lock 36 and the idle brake 38 absorb the opposing force. The modulated pressure from the line 330 passes between the control collars 392 and 394 of the clutch signal valve 390 located in the right position to a line 950 and from there between the control collars 726 and 728 of the control piston 718 located in the upshift position to a line 952, which leads to servo 42 ', which applies overtaking brake 42. The overrunning brake 42 fixes the reaction wheels 22 and 34 of the front and rear planetary gears in both directions of rotation, although only wheel 22 is required in second gear. During overrun, in which the one-way lock 36 would allow the reaction wheel 22 to rotate forward, this is prevented by the overrunning brake. If the reaction wheel 22 were allowed to rotate forward, the front planetary gear mechanism 16 would be without a reaction wheel and would be switched off, so that the connection between the input shaft 10 and the output shaft 12 would be interrupted during overrun operation. The resistance of the motor could then not be used to decelerate the vehicle. Manual downshifting from second to first gear To achieve this downshift, the selector valve 140 is moved to position L, in which the control collars 144 and 146 connect the lines 810, 174 and 328 to the main delivery line 108 . The control collar 144 prevents a flow of liquid from the line 108 to the line 180, so that the control chamber 178 of the shut-off valve 160 is relieved of pressure. The pressure in the opposite control chamber 172 will therefore switch the shut-off valve 160 downward. The fluid pressure in the line 328 holds the switching valve 780 from third to fourth gear in the downshift position, the line 906 leading to the switching valve 750 from second to third gear is supplied by branch line 942 of line 174. The pressure in line 906 holds the switch valve 750 from second to third gear in the downshift position. The shut-off valve 160, which is switched downwards, also directs pressure fluid from the branch line 942 to the line 894, which leads to the control piston 718. The pressure fluid is therefore fed between the control collars 724 and 726 of this control piston to the line 892 and from there via the control piston 730 to the line 891 and enters the spring chamber between the valve slide 710 and the control piston 730. The pressure acting in this holds the switching valve 710 from first to second gear in the downshift position.

A branch line 954 of the line 894 leads to the control piston 694 and the pressure prevailing in it opposes the G-1 pressure, so that the switching valve 680 is held in the downshift position from first gear to first intermediate gear is until a certain driving speed, for example 51.5 km / h, is reached will.

Since all changeover valves are in the downshift position, remains the transmission in first gear until this specific travel speed is reached.

Downshifting from second gear to first intermediate gear using the accelerator pedal Downshifting from second gear to first intermediate gear can be achieved in a certain driving speed range, e.g. B. between 22.5 and 69.1 km / h, can be achieved by depressing the accelerator pedal 196 until the switch 190 closes. Then the pressure of the liquid in the control chamber 178 is relieved and the pressure in the control chamber 172 moves the check valve 160 to the left. Pressure fluid then passes from the branch line 942 of the pipe 174 to the pipe 894 and from there between the control collars 722 and 7'4 de-3 upwardly connected control piston 718 to the hole 8f0, which leads to and from the control piston 730 opens. Pressure fluid then flows via the line 891 into the space between the valve slide 710 and the control piston 730, as a result of which the changeover valve 710 is moved into the downshift position. In this position, the control collar 714 blocks the supply of pressure fluid from the branch line 878 of the line 174, the branch line 928, the line 658 and the branch line 932, which lead to the left side of the clutch signal valve 390. If the switching valve 710 is in the downshift position from the first to the second gear, the branch line 928 of the line 658 is connected to a line 960 between the control collars 714 and 716, which passes through a bore in the valve 370 to the downward switching valve 750 from the second to the third Corridor leads. Between its control connections 754 and 756, the lines 960 and 602 are connected to the branch line 940 of the line 602, which leads to the right side of the clutch signal valve 390.

At this point, the downshift valve 370 acts to control the flow of liquid out of the line 658 and its branches through an outlet 962 in the bore of the valve 370. Outlet 962 is the only way to relieve line 658. The TV pressure, which is at its maximum because the accelerator pedal 196 is depressed, acts on one end of valve 370 against the pressure in line 960 and springs 374 and 376 The preload of the springs 374 and 376 and the diameter of the valve slide 372 are matched to one another so that the pressure in the line 960 is initially held at a certain value by the action of the downshift valve 370. In order to help maintain this pressure, the reservoir 660 acts as a pump which refills the liquid flowing out through the outlet 692 for a certain time which is determined by the ability of the reservoir 660 to swallow. Preferably the particular pressure, e.g. B. 2.46 kg / cm2, sufficient to keep the clutch 50 only partially engaged so that the resulting slip allows the engine speed to catch up. Then the speed of the pump 100 increases, which conveys more liquid for filling the hydrodynamic coupling 44.

The resulting pressure of 2.46 kg / cm- 'is directed through branch line 932 of line 658 and through branch line 940 to opposite sides of clutch signal valve 390; the spring 400 will therefore predominate and move the clutch signal valve 390 into the position shown. The pressure of 2.46 kg / cm2, which then prevails in line 936, will keep the shaker valve 460 in the right position, but will not affect the clutch filling valve 440, since the combined force of the spring 446 and the pressure of 2.46 kg / cm2 is less than the force exerted by the pressure from branch line 814 on the right side. The valve 440 will therefore open and connect the coupling fill line 818 to the branch line 816 of the main delivery line 108. The clutch 64 will remain partially engaged and the hydrodynamic clutch 44 will fill more quickly via the clutch valve 350 and the clutch fill valve 440. When the pressure in the hydrodynamic coupling 44 reaches a certain value, e.g. B. 2.11 kg / cm2, the valve 370 causes the connection of the clutch fill line 818 with the branch line 828 to the right side of the valve slide 372 and thus changes the control action of the valve 370. Then the clutch 50 terminates the disengagement at a speed that is determined by the TV pressure and the pressure build-up in the hydrodynamic clutch 44, and the shaking valve 460 will return to the position shown, in which the line 918 from the switching valve 680 from the first gear to the first intermediate gear is connected to the line 920 to the overdrive transmission valve 510. The overdrive; Z 510 will then supply the overdrive brake servo 62 'with pressure fluid via the clutch delay valve 550 in order to apply the overdrive brake 62.

The described sequence of operations results in rapid filling of the hydrodynamic clutch 44, while clutch 50 is initially only partially disengaged and then fully disengaged at a controlled speed. The first intermediate course is therefore switched on gradually and softly, although it is considerably more open Motor throttle is made.

Downshifting from the first intermediate gear to the first gear using the accelerator pedal. B. from 8.05 to 24.15 km / h, to obtain a downshift to first gear in the first intermediate gear by depressing the accelerator pedal 196 until the switch 190 closes to the shut-off valve 160, as already described, downwards switch. In this position of the shut-off valve 160, the branch line 942 of the line 174 is connected to the line 894 between the control collars 166 and 168. Through the branch line 954 of the line 894, pressure fluid is fed to the control piston 694, the pressure of which counteracts the G-1 pressure, so that the switching valve 680 is moved from the first gear to the first intermediate gear into the position shown in which the pressure from the branch line 882 the line 174 is shut off from the line 918. Since the shaking valve 460 is in the position shown, the line 920 connected to it, which leads to the left side of the overdrive transmission valve 510 , and also the line 918 through an outlet 964 in the bore of the switching valve 680 are relieved. The overdrive transmission valve 1510 is therefore moved to the left causing the overdrive brake 62 to be released and the clutch 64 to be engaged to obtain first gear.

Low drive range For the low drive range this is Selector valve 140 moved to the right to the L position. Then, as with the hand-operated Switching from second to first gear explained, all switching valves in the downshift position held, so that the transmission is in first gear. It stays in this until the above-mentioned driving speed of 51.6 km / h is reached.

Reverse drive For the reverse drive, the selector valve 140 is brought into position R, in which the control collars 142 and 144 connect the main delivery line 108 to a line 970 which leads to the reverse gear brake servo 67 '. In the position R, the control collar 142 separates the line 970 from an outlet 972, while in all other positions of the selector valve 140 there is a connection between the line 970 and the outlet 972. The acted upon servo 67 ′ applies the reverse gear brake 67, which holds the ring gear 20 of the front planetary gear transmission 16 in place. The rest of the controller is in an idle state. From the main delivery line 108, pressure fluid is conducted via the branch lines 418 and 811, through the coupling signal valve 1390, the line 812 and the branch line 814 to the coupling filling valve 440, which is set so that the branch line 816 of the main delivery line 108 is connected to the coupling filling line 818. The hydrodynamic coupling 44 is also filled from the main delivery line 108 via the branch lines 490 and 824, via the coupling valve 350 and the branch line 828 of the line 818. Furthermore, the branch line 490 is connected via the branch line 862 to the overdrive transmission valve 510 which, in the position shown, conducts pressure fluid to the servo 64 ' , which engages the clutch 64.

As already mentioned, with reverse drive, the drive goes from the input shaft 10 via the hydrodynamic clutch 44 to the rear planetary gear train 18, the ring gear 34 of which runs backwards, although the idle brake 38 is applied and which drives the sun gear 22 of the front planetary gear train 16 backwards. Since its ring gear 20 is held by the reverse brake 67, the planetary gear carrier 26 of the front and the planetary gear carrier 28 of the rear planetary gear and thus the intermediate shaft 29 and the output shaft are driven backwards at a reduced speed. Downshifting when the engine throttle is closed When the vehicle speed is reduced by closing the engine throttle, the downshifts take place in the reverse order, but at different travel speeds than the upward shift occurs. Is the upshift, e.g. B. provided at 22.5 km / h, the corresponding downshift takes place at a lower driving speed, z. B. 16.1 km / h. This results from the reduction of the TV pressure to a minimum value when the motor throttle is closed. In addition, the control device has a hysteresis effect due to the use of differently sized control bundles in the individual switchover valves. So has z. B. the control collar 784 of the switching valve 780 from third to fourth gear larger diameter than the control collar 786, so that the control collar 784 has a larger area acted upon by the pressure in the line 800 when the valve 780 is in the upshift position, so that on him a greater force is exerted tending to hold the valve in place. The regulator pressure acting on this valve must therefore, at the same TV pressure, drop to a lower value than was necessary to switch the valve upwards to the right.

The other switching valves all have control collars with surfaces of different sizes, which result in this hysteresis effect. The tax collar 754 z. B. the switching valve 750 from second to third gear has a larger diameter than the control collar 756. The control collar 714 of the switching valve 710 from first to second gear has a larger diameter than the control collar 716, and the control collar 684 of the switching valve 680 from first gear to the first intermediate gear is larger than the control collar 668.

Emptying the control device after the vehicle comes to a standstill come, the engine switched off and the selector valve 140 brought to the N or P position are, the control device empties as follows: The overdrive brake 62 and the clutch 50 will already be released during the previous downshift.

The hydrodynamic coupling 44 empties to the extent that the outlet valves 830 permit, since these can be in the uppermost position when the pump wheel 46 stops. The remaining liquid drains off in a certain period of time due to leakage on the clutch housing. If the system was previously in reverse drive, the reverse gear brake 67 is emptied via the selector valve 140 to the outlet 972. The idle brake servo 38 'is emptied through the spring leaf 868, which is in the adjusted position, and via the idle brake valve 300 through the outlet at the open end of the bore of the selector valve 140. The overhaul brake servo 42' is emptied via the line 952 between the control collars 726 and 728 of the control piston 718, the line 810 to the outlet at the open end of the bore of the selector valve 140. The clutch servo 64 'is emptied via the outlet 566 of the clutch delay valve 550 in the position shown.

Thus, all devices working with friction are used for manufacturing the power paths solved by the gearbox, so that no drive in any direction can be passed through the transmission.

The control device described enables six forward gears and a reverse gear. However, their structure is such that various parts are omitted and other combinations of gears can be provided without affecting the impossible close. The six-speed transmission system described can be converted into a three-speed transmission can be converted by the fact that the overdrive transmission 52 and its control necessary part of the control device is omitted. In this case allow the intermediate shaft 29, the output shaft and the front and rear planetary gears 16 and 18 the same first, second and third gear as well as the same Reverse gear. If this is not done, of course, the first intermediate course, the second intermediate course and fourth gear. The following valves and are in the control device their Supply lines in discontinuation: the switching valve 680 from the first gear to the first intermediate gear, the switching valve 780 from third to fourth gear, the G-3 valve 480, the shaking valve 460, the clutch delay valve 550, the overdrive transmission valve 510, the Memory 530 and the manually operated overdrive gear valve 578.

In another modification, the overdrive transmission 52 would be retained, but the first intermediate gear and the second intermediate gear could be omitted. The switching valve 680 from the first gear to the first intermediate gear, the G-3 valve 780, the shaking valve 460 and the pressure switch 600 can then be dispensed with in the control device and can be omitted. The first three gears are then available and, as already described, it can be switched to fourth or overdrive either automatically or manually. The automatic switching to fourth gear requires the manual overdrive transmission valve 578 to be set to the overdrive position, so that the switch 598 blocks the supply of pressure fluid via line 592 to the right side of the overdrive transmission valve 510. If the switching valve 780 shifts up from third to fourth gear, pressure fluid is directed via line 920 to the left side of the overdrive transmission valve 510 and the overdrive brake 62 is applied. If the switch 598 is in the position for direct drive, the fourth gear can only be reached after the switch 598 has been changed over, even if the switching valve 780 is in the upshifting position from third to fourth gear, as the combined effect of the pressure from the line 592 and the spring 512 is greater than that of the pressure from the line 920 and the overdrive transmission valve 510 is therefore held in the down position.

There are therefore three different transmissions described, two of which, namely the three-speed transmission and the four-speed transmission, modifications of the individual are described six-speed transmission. The gear changes can be performed on all transmissions run automatically and have three forward drive ranges. Furthermore is Downshifting with the accelerator pedal and downshifting with partial open engine throttle possible in order to obtain maximum performance from each transmission.

Claims (10)

Claims: 1. Hydraulic control device for a change gear, in particular for motor vehicles, in which an input shaft driven by the engine can be connected via a hydrodynamic coupling to the input element of one of two planetary gears having a common output shaft and via a clutch operated by hydraulic fluid to the input element of the other planetary gear, characterized in that a fluid pump (100) of variable delivery rate driven in a manner known per se with a speed proportional to the speed of the input shaft (10) supplies a main delivery line (108) with hydraulic fluid which is used for engaging the hydraulic fluid-operated clutch (50) and / or filling the hydrodynamic clutch (44) is used, and when disengaging the hydraulic fluid-operated clutch (50) and filling the hydrodynamic clutch (44) for the purpose of downshifting through a switching valve (710) one with a hydrau The delivery line (928) connected to the hydraulic fluid-actuated clutch is separated from the main delivery line (108) and connected to a line (960) in which the pressure is kept at a low value by the pressure-sensitive element of a downward valve (370), so that slip occurs in the hydraulic fluid operated clutch (50) and the speed of the motor-driven input shaft (10) and thus the delivery rate of the fluid pump (100) increases, this low pressure being fed to a clutch signal valve (390) which controls the main delivery line ( 108) feeds the increased flow rate of the pump to the hydrodynamic coupling (44) , which is quickly filled to complete the hold-down. 2. Control device according to claim 1, characterized in that the pressure-sensitive Member of the downshift valve (370) a pressure corresponding to the engine torque (Line 875) and in the opposite direction of the force of springs (374, 376) and the low pressure in the line (960) connected to the delivery line (928) is exposed. 3. Control device according to claim 1 or 2, characterized in that for controlling the increased pump delivery rate from the main delivery line (108) to the hydrodynamic coupling (44), the coupling signal valve (390) sends a pressure pulse via a line (812, 814) to a coupling filling valve (440) which moves its valve member against the force of a spring (446) in order to connect a delivery line (818) for the hydrodynamic coupling to the main delivery line. 4. Gearbox for use with a control device, only according to one of claims 1 to 3, characterized in that the common shaft (29) the planetary gear carrier (26, 28) of the two planetary gears with the input element (54) of an overdrive planetary gear transmission (52) is connected. 5. Change transmission according to claim 4, characterized in that the input element (54) and the reaction element (60) of the overdrive planetary gear transmission (52) via a one-way clutch (66) are connected. 6. change gear according to claim 4 or 5, characterized by a fluid operated clutch (64) between the input member (54) and the Reaction element (60) of the overdrive planetary gear transmission (52) and a fluid-operated Brake (62) for its reaction element (60). 7. Control device in a change gearbox according to claim 6, characterized in that a change in the pressure fluid supply to the clutch (64) and to the brake (62) of the overdrive planetary gear (52) is effected by an overdrive gear valve (510) which is between a first position in which a first outlet (562) of the overdrive transmission valve is connected to a pressure line (862) and a second outlet (538) is relieved (at 922) , and is movable to a second position in which the first outlet (562) is relieved (at 922) and the second outlet (538) is connected to the pressure line (862) via a throttle point (926). B. Control device according to claim 7, characterized in that the first outlet (562) of the overdrive transmission valve (5'10) with an outlet line containing a clutch delay valve (550) (564) is connected. 9. Control device according to claim 7 or 8, characterized in that that the switching of the overdrive transmission valve (510) by hand by supplying pressure medium (Line 592) can be controlled via a solenoid-operated manual valve (578). 10. Control device according to claim 9, characterized in that the excitation coil (581) of the magnet with a liquid pressure switch (600) is in a circuit. Considered publications: German Patent Nos. 822 043, 899146, 922 507; German interpretative document B 15245 I1 / 63 c (published on 10.13.1955); French Patent No. 1143 726; U.S. Patent Nos. 2,312,849, 2,728,247, 2749775.