DE1255389B - Control device for a hydrostatic vehicle drive driven by an internal combustion engine - Google Patents

Abstract

1,011,700. Hydrostatic transmissions. ROBERT BOSCH G.m.b.H. Aug. 4, 1964 [July 25, 1963], No. 31022/64. Heading F2D. In a vehicle transmission including an hydrostatic gear unit and centrifugal regulators for controlling the engine fuel pump and the gear unit respectively, the accelerator pedal is so coupled to the regulators that during its movement it is first effective only on the engine regulator, then on both the engine regulator and the loading spring of the gear regulator, and finally only on the gear regulator loading spring. In the arrangement shown, an engine 1, fitted with an injection fuel pump 2 is coupled by a shaft 11 and clutch 13 to the pump 4 of a swash plate type pump and motor gear unit 4, 5, controlled by an hydraulic regulator 6 comprising a piston 39 loaded by a centering spring 45 and connected to a servo control valve 60 connected to the gear unit swash plate 52 by a linkage 51. The gear regulator 7 comprises a pressure-control valve 18 connected to the servo unit 6 through a forward and reverse selector valve 32. Valve 18 is controlled by a loading spring 24 and a centrifugal regulator 7, of which the balls 28 are driven by a disc 27 geared to the engine shaft 11. An engine-driven centrifugal governor 8 is coupled to the fuel pump 2 by a link 71. The accelerator pedal 15 operates a by-pass valve 86 and a stirrup 80 bearing aginst cams 79, 83, the former of which is coupled to link 71 by a linkage 75, 76, 77, while the latter operates a rod 85 connected to a crank lever 26 engaging the loading spring 24 of gear regulator 7. Cam 83 may also be operated independently by a brake pedal 95 and push-rod 94. Operation.-Initial movement of accelerator pecal 15 causes operation of fuel pump 2 by cam 79 and linkage 75, 76, 77, but rod 85 bears against a horizontal portion 83¹ of cam 83 and so is not affected. Centrifugal regulator 7 acts upon pressure regulating valve 18 to raise the control pressure to operate piston 39 and so tilt swash plate 52 to initiate functioning of the gear unit 4, 5. Upon further movement of pedal 15 cam 83 becomes effective to vary the loading of spring 24, but over the final stage of movement of the pedal the horizontal portion 79¹ of cam 79 renders the latter ineffective upon the fuel pump 2, but cam 83 is still operative upon loading spring 24. With pedal 15 released, operation of brake pedal 95 causes displacement of cam 83 so that the loading of spring 24 is controlled by crank lever 26 whereby the ratio of the gear unit is adjusted to conform to the engine braking torque.

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

F02d

German KL: 46 b2 - 19/01

Number: 1 255 389

File number: B 728371 a / 46 b2

Filing date: July 25, 1963

Open date: November 30, 1967

The invention relates to a control device for an engine driven by an internal combustion engine hydrostatic vehicle drive, which depends on the speed of the internal combustion engine and the Position of a drive lever the energy supply to the internal combustion engine and a translation of the hydrostatic transmission-determining control element influences in which the drive lever is a spring tensions the flyweights driven by the internal combustion engine against the force on the gear ratio determining control member acts, and between the control lever and the control member Transmission means are clamped, the changes in the travel lever position non-linearly to the control element forward.

The German patent specification 1 060 189 discloses a fluid flow transmission driven by an internal combustion engine known for driving a motor vehicle, with a common control device for setting the amount of fuel in the internal combustion engine and one that determines the transmission ratio of the fluid flow transmission Actuator (adjustable blades). The control device consists of one driven by the internal combustion engine Centrifugal governor, which can be influenced by a speed adjustment device serving as a setpoint generator is. Its values are used both for supplying fuel to the internal combustion engine Link directly and superimposed via a linkage also to a torque controller for the fluid transmission given.

This arrangement has the disadvantage that an optimal control the internal combustion engine, d. H. an operating state in which they always work under full load can, is not possible. They also have to accelerate the vehicle at the same time, for example the mass of the internal combustion engine accelerates and the transmission ratio of the fluid transmission be changed. However, it is desirable to carry out these processes one after the other.

A hydrostatic vehicle drive of this type is also known from US Pat. No. 2,516,662, but it has two centrifugal governors. One is in turn driven by the internal combustion engine and adjusts its fuel metering element, the other by a non-driven vehicle wheel. The latter regulates the driving speed of the vehicle in accordance with a certain driving lever position to a constant value and also prevents a vehicle wheel ζ. B. can spin on a damp surface. The centrifugal governor of the internal combustion engine provides a control device for a
Internal combustion engine driven
hydrostatic vehicle drive

Applicant:

Robert Bosch G. m. B. H.,

Stuttgart 1, Breitscheidstr. 4th

Named as inventor:
Ulrich Aldinger,
Franz Eheim, Stuttgart

that it can work largely at full load. The good adaptation to the various driving conditions achieved with this control device is, however, only achieved with a great deal of effort in terms of control valves, rods and cams. If the servo adjusting devices required today were to replace the mechanical adjustment means for the gear pump and gear motor, the construction cost of such a drive would be unjustifiably expensive and even more complicated.
Furthermore, a vehicle with a hydrostatic travel drive is known from US Pat. No. 2,500,580, the pump of which is also driven by an internal combustion engine. The transmission ratio of the hydrostatic transmission is determined with the aid of a centrifugal governor that is driven by the internal combustion engine. The position of the throttle valve of the internal combustion engine is not subject to a controller, but is inevitably dependent on the position of the accelerator pedal. The position of the accelerator pedal, however, also acts on the centrifugal governor via a spring tensioner, whereby its setpoint can be changed. As a result, the transmission ratio of the hydrostatic transmission is adapted to the load on the internal combustion engine, so that the internal combustion engine cannot stall. Again, as in the case of the transmission mentioned above, only one controller is provided, which has the disadvantage that a sensitive control of the drive system that is optimally adapted to the corresponding driving conditions is not possible. Such drives are sufficient for those cases in which economic efficiency only plays a subordinate role. So-called hydrostatic braking is not possible with them.

709 690/109

US Pat. No. 3 003 309 also discloses a travel drive with an internal combustion engine known hydrostatic transmission with single lever. With the help of the drive lever two cams operated, one of which controls the fuel metering element of the internal combustion engine, the other takes care of the adjustment of the hydrostatic transmission. Between the last-mentioned cam and the controllable pump of the hydrostatic transmission are displaceable transmission means switched on, which, however, cannot be operated independently of one another, so that only a rough adjustment of the drive to different driving conditions is possible.

In contrast, the invention is based on the object of addressing the disadvantages of the known arrangements to avoid and to create a control device for a travel drive of the type mentioned above, which is optimally adapted to the various driving conditions with justifiable construction costs, d. H. at which the internal combustion engine can almost always work at full load, and with its help too hydrostatic braking is possible.

This is achieved according to the invention in that the control device, as known per se, from consists of two independent regulators, namely a machine regulator for the energy supply element determining the internal combustion engine and a gear controller for the hydrostatic gear, and that the one between the drive lever, which determines the energy supply to the internal combustion engine Member and the spring to be tensioned switched transmission means are shaped in such a way that they are at small pivot travel of the driving lever, as is known per se, only on that which determines the energy supply Link, in the subsequent swivel area also on the spring, and in the end area of the swivel path continue to act increasingly only on the spring.

Particularly expedient developments of the subject matter of the invention emerge from the subclaims.

An embodiment of the subject matter of the invention is shown in the drawing. she shows a vehicle drive in a partially simplified representation.

The vehicle drive essentially comprises an internal combustion engine 1 designed as a diesel engine, which is provided with an injection pump 2, a hydraulic transmission 3 with an oil pump 4 and an oil motor 5, an adjusting device 6 for this gear, a gear controller 7 and an end controller 8. From the internal combustion engine A feed pump 9 for the transmission controller and an auxiliary pump 10 are driven from. Furthermore, the drive shaft 11 of the internal combustion engine, which carries a gear 12, is via a clutch 13 connected to the drive shaft 14 of the hydraulic transmission. These in reality are close together lying parts are for the sake of clarity in different places of the drawing reproduced. Furthermore, the vehicle provided with the drive has a drive lever 15, he as an accelerator pedal may be formed, and a preselector lever 16 for selecting the direction of travel.

The transmission regulator has a control valve with a valve housing 17 in which a closing member 18 slides is led. It controls the connection between an inlet 19 and an outlet 20 of the valve housing. The inlet is supplied with pressure oil via a line 21 from the feed pump 9. The one occurring there Pressure acts in the opening direction on the closing member 18. In the closing direction acts on the Closing member is a bolt 22 which is firmly connected to a conical disk 23. On the conical disk a spring 24 presses in the opening direction, the other end of which rests on a bolt 22 displaceable disk 25 is supported. This in turn rests on one end of a rotatable on the controller housing

ίο mounted angle lever 26.

Between the conical disk 23 and a flat running disk 27 are balls serving as flyweights 28 inserted. With the running disk 27, a gear 29 is connected to the gear 12 of the Drive shaft meshes. It moves the balls 28 together with the conical disk 23 proportionally to the speed of the Internal combustion engine in rotation. The spring 24, whose force acts on the bolt 22 via the conical disk 23 acts, seeks the locking member 18 from its seat

zo to remove. The flyweights 28 act as soon as they rotate around the axis of the bolt 22, counter to this spring tension, as they push the conical disk 23 try to push to the right in the drawing. So the faster they spin, the bigger it gets the opening pressure of the control valve 17 to 20. This opening pressure is used as a control variable for the transmission controller.

A control line 30 is connected to the inlet 19. It leads to the housing 31 of a directional control valve, whose slide 32 is connected to the preselector lever 16. According to the position of this lever a recess 33 in the slide connects the control line 30 to one of two branch lines 34, 35 of this control line. A throttle point 36, 37 is inserted in each of the two branch lines.

Each of these branch lines leads to one end of a control cylinder 38 of the adjustment device 6. In A pilot piston 39 slides in the cylinder, the piston rod 40 of which is led out of the cylinder in a sealing manner is. The piston rod carries stops 41, 42, which with spring plates 43, 44 one between them Discs clamped return spring 45 and ^ ehäusefesten Stops cooperate so that they seek to keep the piston in a central position.

A pilot valve 46 is connected to the piston rod 40. It slides in an actuating piston 47, the is in turn guided in a sealing cylinder 48 at two points so that it has end spaces 49, 50 divides in the actuating cylinder.

The actuating piston 47 is articulated to the pivotable swash plate 52 of the oil pump via a linkage 51 4 connected. The position of the actuating piston therefore determines its stroke, i. H. the delivery rate the oil pump.

A transmission circuit is formed between the oil pump and the oil motor, depending on the direction of travel Branches serving as pressure or suction lines are denoted by 53, 54. Both branches are over One check valve 55, 56 each is connected to one end space 50 of the actuating cylinder. (The check valves open towards this end space). From the end space a channel 57 goes into the Pilot valve 46 leading bore 58 of the actuating piston. With the help of collars 59, 60 and channels 61 provides the pilot valve 46, depending on its position, a connection between the channel 57 and a Outlet 62 or a channel 63 ago, through a divided piece of the bore 58 with the end space

49 of the actuating cylinder is connected. The effective cross-section of this end space is larger than that of the End space 50.

The auxiliary pump 10 is connected to the two branches of the transmission circuit via a check valve 64, 65 each connected, so that they always receive pressure medium even when the pump 4 is not pumping, the for Actuation of the actuating piston is sufficient.

The end regulator 8 is a centrifugal regulator whose weights 66, 67 are proportional to the speed of the shaft 11 are driven. According to their deflection, they move a sleeve 68, the collar 69 with it a pin 70 slidably but non-rotatably held on the controller housing. The regulator is with the injection pump assembled. An intermediate lever 71 is articulated to the collar 69 of the sleeve, which is connected to its opposite end is articulated to the control rod 72 of the injection pump. In The intermediate lever has an elongated hole 73 in its middle section. A hinge pin engages in this an angle lever 75, which is also mounted on the controller housing. Its other end is over one Rod 76 connected to one end of a second angle lever 77, the other end of which is a Tactile member serving role 78 carries.

The roller 78 rests on a curved track 79, which is slidably guided and with one leg of a Stirrup 80 is connected. A section 79 'of the cam track, which the roller 78 when swiveled strongly Reached the drive lever, does not affect the position of the angle lever 77 when the cam path 79 is shifted. A second leg of this bracket serves as a plunger 81, against which it rests under the action of a pressure spring 82 a second curved path 83 lays. On it slides with the help of a roller 84, which acts as a feeler member serves, a rod 85 whose end facing away from the roller is hinged to the angle lever 26. A section 83 'of the cam track on which the roller 84 rests when the drive lever is only slightly pivoted, does not influence the position of the rod 85 when the cam 83 is shifted.

The bracket 80 is connected to a slide 86 which, together with a housing 87, forms a short-circuit valve forms. The drive lever 15 is connected to the slide in an articulated manner. From two recesses 88, 89 of the housing 87 each lead a line 90, 91 to both branches 53, 54 of the transmission circuit. A groove 92 of the slide 86 is designed so that when the drive lever is in the rest position, it can move the lines 90, 91 connects to one another, d. H. the gearbox short-circuits ineffectively when the drive lever is actuated however, separates the lines from each other.

Opposite an end face 93 of the cam track 83, which serves as a support for the plunger 81, is also attached the end of a second tappet 94 which is slidably mounted and connected to the brake pedal 95 of the vehicle is connected.

The drive works as follows:

1. Start

When the internal combustion engine (the diesel engine) is to start, it is usually used as an accelerator pedal trained driving levers up to the starting quantity stop, so completely stepped through. This shifts the slide 86 with the bracket 80 moves to the left, the cam track 79 pivots with the aid of the roller 78 the angle lever 77 clockwise so that the angle lever 75 is rotated in the opposite direction of rotation will. The hinge pin 74 of the angle lever 75 thereby pivots the intermediate lever 71 its fulcrum located on the collar 69 and thus pushes the control rod 72 to the left. The injection pump is thereby set to the starting quantity, the engine is started.

At the same time, the cam 83 has pivoted the angle lever 26 via the rod 85 so that

ίο he compresses the spring 24 to its highest tension. The bolt 22 therefore keeps the control valve 17, 18 open; coming from the feed pump 9 Fluid can flow out through the valve without pressure. The control cylinder 38 therefore also remains pressureless, the pilot piston 39 in its rest position, and the oil pump 4 of the transmission rotates without promoting.

2. Idle

The drive lever is released and is located

so in its rest position. The cam tracks 79 and 83 have therefore moved to the right again. The angle lever 77 is rotated back counterclockwise and is in its end position, so that the hinge pin 74 is also fixed. The end controller 8 swivels now the intermediate lever 71 around this bolt and thereby regulates according to the speed of the engine the position of the control rod.

Since the rod 85 has also returned to an uppermost end position, the spring 22 has no tension more. The balls 28 of the governor 27, 28, 29 run around and around the idle speed exert a certain closing force on the regulating member 18. The liquid pressure in the control line therefore increases. But it is not yet large enough to hold the pilot piston 39 against the tension of it to move holding spring. The short-circuit valve 86, 87 connects the branches of the drive circuit, so that the vehicle can roll freely.

3. Start up

The preselector lever 16 is brought into a position corresponding to the desired direction of travel; shown is the position for forward travel, in which the control line over the line branch 35 and the Throttle point 37 is connected to the right end of the control cylinder 38.

If the drive lever is now slowly depressed, the cam 79 first acts on the angle lever 77, pivots it and sets the control rod 72 of the injection pump so that the engine is supplied with a sufficient amount of fuel to deliver power. At the same time the short-circuit valve is closed.
The cam track 83 initially does not yet act with its section 83 ′ on the rod 85 and the spring 22. Therefore, the closing pressure of the control valve initially rises proportionally to the centrifugal force occurring on the balls 28. The pressure in the control line 30 and in the control cylinder increases accordingly

38. The pilot piston 39 moves to the left and moves the pilot valve 46 accordingly. This relieves the left side of the actuating piston 47, so that it is different from the one prevailing on its right side Pressure is shifted to the left and the grinding wheel 52 of the oil pump 4 is pivoted.

As long as the pump is not yet delivering, the pressure required for this adjustment is provided by the auxiliary pump 10 delivered. If the swash plate is swiveled,

the pump begins to deliver, the oil motor 5 rotates and the vehicle starts moving.

If the driving lever is further depressed, the cam track 79 adjusts the one leading to the control rod 72 Linkage until the engine receives its full injection quantity. He can therefore make the best use of it work this amount.

Shortly before this state is reached, the section 83 'of the cam path 83 has also started Tension spring 22. As a result, the control valve 18 was loaded in the opening direction, and the pressure in the control line 30 initially drops. The throttle 37 prevents, however, that the pilot piston 39 in " its rest position returns, so that the gear ratio is not significantly at this moment changes. The vehicle will only continue after reaching a preselected speed of the diesel engine accelerated. The engine had previously had the opportunity, with the help of its power, to first its own masses to accelerate to the extent necessary.

With the increased gear ratio that has now been set, the diesel engine does not yet need its full output submit. Its speed therefore continues to increase. As a result, however, the balls 28 on the Closing member 18, the force exerted is greater, the pressure in the control line 30 rises and the pilot piston 39 continue to the left. The adjusting piston swivels the swash plate more and more, so that the Pump promotes more and more and the oil motor is driven faster and faster, the translation of the transmission therefore decreases. These processes continue until a state of equilibrium is established Has. The vehicle starts off smoothly, with the machine at full power right from the start. This is mainly due to the graduated action of the cam tracks 79, 83.

The resulting gear ratio depends on the preselected engine power and the Load on the vehicle. The diesel engine can therefore always operate in the full load range, i.e. H. under optimal conditions, work.

4. Driving on an incline

If the vehicle comes up a slope in the above-described condition, it falls because of the required additional power first the speed of the internal combustion engine 1. This will make the the closing force exerted on the balls 28 on the closing member 18 is smaller and the "pressure in the control line sinks. As a result, the pressure in the control cylinder 38 also decreases and the actuating device 6 pivots the swash plate 52 from so that the pump 4 delivers less. The translation is therefore increased. That continues until a state of equilibrium occurs again. The performance of the engine remains the same as before, the speed has decreased accordingly.

5. Driving on a slight slope

If the vehicle is on a slight slope in the condition described under 3, the will rise Speed of the internal combustion engine, the force exerted by the balls 28 increases, and vice versa As described under 4, the pressure used as the manipulated variable increases. The pump 4 is therefore placed on greater funding, the translation becomes smaller. The speed of the vehicle decreases to, the performance of the machine remains the same again.

6. Accelerate while staying the same
Slope of the road

If the drive has worked itself into equilibrium at a certain driving lever position, then the control rod 72 is in the position for full delivery rate. If the driver continues to press the drive lever, so the spring 22 of the gear regulator 7 is more tensioned. (The feeler member 78 can already open

ίο the section 79 'of the curved path are so that the linkage 75, 76, 77 is no longer adjusted). The bolt 22 is loaded in the opening direction, the Pressure in the control line 30 drops. The translation of the transmission does not change significantly because the Throttle point prevents the pressure drop from acting quickly. The machine now has time, its own Accelerate mass; this increases the speed and, via the force of the balls 28, also the pressure in the control line 30 on again. The translation is adjusted accordingly, it plays itself on a balance at a new, increased speed.

7. Decelerate if the incline remains the same
the street

If the drive is in equilibrium and the drive lever is returned to its rest position, so the spring 24 is first relieved and the pressure generated by the gear controller increases. The throttle point 37 prevents the adjusting device from quickly following this pressure fluctuation. A small one Adjusting the gearbox leads to an additional load on the engine. Whose speed increases thereby, which brings a relief of the control valve with it. The pressure in the control line 30 increases as a result, the gearbox adjusts to a larger ratio and the vehicle drives with one slower speed further.

8. Brakes

When braking, the drive lever is returned to its rest position. The cam 79 causes that the intermediate lever 71 moves into the idle position. The diesel engine therefore runs with a dated End controller 8 continued idling speed.

At the same time, the spring 24 is completely relaxed via the cam 83. The total centrifugal force of the Balls 28 affects the control valve, the pressure in the control line rises and the transmission approaches the ratio 1: 1. The corresponding final state corresponds to braking directly Corridor.

When the brake pedal 95 is depressed, the tappet 94 now acts on the end face 93 of the cam track 83 and pushes it to the left so that it lifts off the plunger 81. With the help of the rod 85 is the spring 24 depending on the. Strength of the applied braking force tense. The one from the control valve The generated control pressure drops accordingly, and a gear ratio is set, which corresponds to the best braking effect achievable by the internal combustion engine.

9. Overload protection

When the diesel engine reaches its upper limit speed, the end controller reduces the speed above Injection pump supplied fuel, d. H. Amount of energy; the engine can therefore not overspeed. Runs

If the motor falls below its limit speed and the load increases, it slows down and so does the gear controller sets a higher ratio of the transmission, so that the load on the engine is reduced. in the Transmission is a known overflow valve 5 is arranged that when the transmission pressure is exceeded opens.

If you put the preselector lever 16 in its other position, so that the control line 30 with the left End of the control cylinder 38 is connected, the control pressure pivots the swash plate 52 in the opposite inclination. Pressure and suction side in branches 53 and 54 of the transmission circuit are reversed, the oil motor 5 rotates in the opposite direction and the vehicle drives backwards. The various vehicle states regulate themselves in the same way as described above, only with the opposite direction when adjusting the gear. Instead of the throttle point 37 is the Throttle point 36 effective.

Instead of a diesel engine, a gasoline engine can also be used as the internal combustion engine. Instead of the control rod 72, a throttle valve is then used to supply energy to the motor rules.

The cam tracks 79 and 83 are shown pulled apart for the sake of clarity. You can in be housed in a body and can also be cams emanating from a circular path, if this body is arranged to be rotatable about an axis. The feeler members 78, 84 can also be used instead of rollers Be sliding shoes or otherwise have a known shape.

Claims (11)

Claims: 35 1. Control device for a hydrostatic driven by an internal combustion engine Vehicle drive, which depends on the speed of the internal combustion engine and the Position of a drive lever the energy supply to the internal combustion engine and a translation of the hydrostatic transmission determining control element influences in which the drive lever a The spring tensions the flyweights driven against the force of the internal combustion engine acts on the control element determining the gear ratio, and in the between the Driving lever and the control element transmission means are clamped, the changes in the driving lever position non-linearly to the control element, characterized in that the control device, as known per se, consists of two independent controllers, namely from a machine controller (8) for a determining the energy supply to the internal combustion engine Member (72) and a gear controller (7) for the hydrostatic transmission (4, 5), and that the between the. Driving lever, the member (72) determining the energy supply to the internal combustion engine and the spring to be tensioned (24) switched on transmission means (79, 83) are shaped such that with a small pivoting path of the driving lever (15), as is known per se, only on the energy supply determining member (72), in the subsequent pivoting range also on the spring (24), and In the end area of the pivoting path, continue to act increasingly only on the spring (24). 2. Control device according to claim 1, characterized in that the transmission means as two cam tracks are formed, one of which is assigned to the machine controller (8), the the other to the gear controller (7), and that both via the common drive lever (15) at the same time can be actuated, but the latter also independently of the first via a brake pedal (95) is movable. 3. Control device according to claim 1 or 2, in which the control element determining the gear ratio generates a fluid pressure serving as a manipulated variable for the gear ratio and is connected via a control line to an actuating device which changes the gear ratio, characterized in that a throttle point (37) in the control line is inserted. 4. Control device according to one of claims 1 to 3, characterized in that the closing member (18) of a control valve in the opening direction by the force of the control lever (15) influenced Spring (24), in the closing direction by a dependent on the speed of the internal combustion engine Force is loaded that this closing member controls the return flow of liquid, which through a feed pump (9) to the inlet (19) of the control valve and the control line connected to it (30) is promoted, and that the control line in turn to the adjusting device (6) of the Transmission (3) is connected. 5. Control device according to one of claims 1 to 4, characterized in that a slide (86) is connected to the drive lever (15) which connects the pressure and suction side of the hydraulic transmission (3) in the rest position of the drive lever. 6. Control device according to claim 2, characterized in that on one of the with the Driving lever (15) connected to two cam tracks (79, 83) which influences the energy supply of the machine Sensing element (78), on the other one influencing the spring tension of the gear regulator (7) Probe member (84) slides, and that the first cam track in one towards the end of the lever movement reached section (79 '), the second reached in one at the beginning of the lever movement Section (83 ') has a shape that does not affect the action of its feeler element. 7. Control device according to claim 6, characterized in that the second cam track (83) only frictionally, in particular under the action of a pressure spring (82), on one with the tappet (81) connected to the drive lever rests and cooperates with a second tappet (94), which is connected to the brake pedal (95) of the vehicle and when this is actuated Pedals, overtaking the first tappet (81), acts on the cam track (81). 8. Control device according to claim 6, characterized in that the feeler member (78) of the first Cam track is connected to one end of an angle lever (75), at the other end of which a Hinge pin (74) is attached, which is in an elongated hole (73) of the intermediate lever (71) slides. 9. Control device according to one of claims 3 to 8, characterized in that in the control 709 690/109 line (30) a directional control valve (31, 32, 33) is inserted to select the direction of travel, which depending on Select the part of the control line (30) coming from the control valve with one of the branches (34, 35) this line connects to different ends of a control cylinder (38) of the transmission actuator (6) lead. 10. Control device according to claim 9, characterized in that the gear actuator (6) contains a pilot piston (39) acted upon by the pressure of the control line (30), which is held in a central position by a spring (45) and with a pilot valve (46) is connected, which comes from the pressure line (35 or 54) of the transmission (3) pressure medium to one side of an actuating piston (47) which the gear part changing the gear ratio (52) adjusted. 11. Control device according to claim 10, characterized in that the transmission (3) from a pump (4) and an oil motor (5), and that the pump (4) is an axial piston pump with a control piston (47) which determines its delivery rate. connected swash plate (52) is. Considered publications:
German Patent No. 1060 189;
U.S. Patents Nos. 2,500,580, 2,516,662,
774 436, 3 003 309. 1 sheet of drawings 709 690/109 11.67 © Bundesdruckerei Berlin