SU761314A1 - Vehicle transmission hydraulic control system - Google Patents

Description

The invention relates to a transport technique, namely to transmission control systems, mainly vehicles with high power engines. five

Hydraulic control systems are known that provide both manual remote control and automatic control, in which stage switchings are carried out depending on the speed of movement and the engine load of the vehicle. “They contain a manual control selector, speed and load sensors and automatic gear switching valves by signals from these sensors, 15 of which are connected to the normally-selected selector outputs, and the outputs are directly connected to the hydraulic cylinders of the friction coupling of the transmission. Such systems are used in cars of mass production, starting with the first automatic transmission ι (1).

A significant drawback of such systems in relation to transmissions of heavy trucks, road construction machines is an increase in their dimensions, determined by the size of transmission hydraulic cylinders, and, consequently, deterioration in accuracy and reliability. If, for example, in passenger cars, the weight of an automatic transmission together with mechanisms

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the hydraulic system does not exceed 100-150 kg, tov heavy transmissions on the power of 5001,000 liters. with. The control system itself weighs the same. In this case, the instantaneous values of the flow rate of the fluid entering the hydraulic cylinders through the control valves also increase several times and reach values at which the hydraulic reactive flow forces affect the operation of the system, and a number of other problems arise. In this regard, it is difficult to create for a heavy transmission a workable system built similarly to a passenger one - according to the full-flow principle.

Also known is a hydraulic transmission control system of a vehicle, comprising a manual control device having inputs connected to a pressure source and normally off outputs, sensors of rotation speed of the output shaft of the transmission and engine load of the vehicle, and automatic control device associated with the normally off outputs of the manual control device. control, and rotational speed and load sensors for switching on the coupling of the gearshift transmissions Twa the signals of said sensor [2].

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In this system, the accuracy is increased and the size of the valves for automatic switching of steps is reduced by reducing the flow of liquid flowing through them and eliminating the influence of hydraulic reactive forces. However, it also has several disadvantages.

A significant disadvantage of this system is a decrease in its reliability compared to full-flow ones. The elements of manual and automatic control are functionally interconnected so that faults of some affect the operation of others. As a result, when automatic control pilot fails, manual control is impaired, even if the selector and its actuator are intact.

In addition, the actuating valves are complex in design, since each of them is connected by separate channels to its corresponding tight automatic valve or to a selector, and for each of them has a separate end control chamber, separated from adjacent chambers by a plunger. The presence of plungers in these valves also reduces reliability, since jamming any of them in the on position disrupts manual and automatic control at the same time.

The purpose of the invention is to improve reliability by ensuring the independent operation of the elements of automatic control and manual control.

This goal is achieved by the fact that the system is equipped with balancing valves, and the automatic control device is made in the form of automatic gear switching valves having one input communicating with a pressure source, and one normally off output of hydraulically controlled actuating valves having one control chamber and connected with on the one hand, with a pressure source, and on the other hand, with gear-box gear sleeves, while the normally disabled valve outputs switching and manual control devices are communicated with the corresponding inputs of the matching valves, and the outputs of the latter are connected to the corresponding control chambers of the mentioned actuating valves.

Matching valves can be made of type "AND" and "OR", or type "NOT".

FIG. 1 shows a hydraulic transmission control system; in fig. 2 and 3 are the second and third versions of the system of FIG. one; in fig. 4 is a table of the inclusion of hydraulic cylinders, actuators and electro-hydraulic valves of FIG. 1-3.

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The proposed device is described with reference to a hydromechanical transmission with four forward and two-speed reverse gears, which is simply shown in FIG. 1. It consists of a torque converter 1 and a planetary gearbox 2. The pumping wheel of the torque converter is connected to the input shaft 3 of the transmission, and the turbine wheel is connected to the input shaft of the gearbox (not shown). The input shaft 3 is connected with the engine, and the output shaft 4 - with the propulsion of the vehicle (not shown). The gearbox has friction clutches for switching stages with hydraulic cylinders 5 and 6, a reverse clutch with hydraulic cylinder 7 and range couplings with hydraulic cylinders 8 and 9, conventionally depicted as hydraulic cylinders, by means of which they are activated. Coupling 8 is the lower coupling, and coupling 9 is the higher stages.

The source of fluid pressure 10 driven by the transmission elements supplies the working fluid from the oil tank through the filter 11 to the main pressure line 12, shown in the drawings with a thick line. The regulator 13 maintains constant pressure in line 12. From the same line, the fluid through the regulator 14 is supplied to the power supply of the torque converter, from where it returns to the oil reservoir through the heat exchanger 15, and through the regulator 16 to the lubrication of the gearbox parts.

The manual control device (Fig. 1) is a selector 17 mounted on the transmission (spool valve) mechanically driven from the vehicle cabin (not shown), which has six positions: 3X1, 3X2,, I, P, A. Selector input channel 18 is connected to the main pressure line 12. Its normally off outputs are connected by channels 19-23 to the inputs of matching valves 24-27 AND, OR, to the input of the automatic stage switching unit and to one of the actuating valves (see below).

The automatic control device consists of a block of 28 valves for automatic switching of steps and a block 29 of actuating valves. Unit 28 contains hydraulic sensors 30, 31 of the angular velocity of the output shaft 4 and the engine load of the vehicle, as well as the valve 32 and valve 33 of automatic switching III — IV and II — III gearbox 2 stages. Automatic switching valves have the same device and differ only in setting . As such valves can be used various known designs. FIG. 1, to clarify the essence of the invention, schematically shows valves consisting of a hydraulically controlled two 761314

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position valve 34 with a spring 35, the tension of which in the process of switching the valve from one position to another is changed by a hydraulic cylinder 36. These elements are indicated only in the image of the valve 32. Each of the valves 32 and 33 has an input to which the supply pressure is supplied, as well as one normal on (reported with input) and one normally off (reported with drainage) output. Normally off the outputs of the channels 37 and 38 are connected to the inputs of the matching valves 24 and 27. The input of the valve 33 is connected to the normally on output of the valve 32. Normally connected outputs by the channels 39 communicate with hydraulic cylinders 36, and the valve output 33 by channels 40 and 41 is additionally communicated with the inputs matching valves 24 and 26. The right, end control chambers of the valves 32 and 33 are connected via channel 42 to the output of the angular velocity sensor 30, and the left cameras from the side of springs 35 by channel 43 to the output of load sensor 31. Various valve settings 32 and 33 are set, for example, the installation efforts of the springs 35.

The block of actuating valves 29 consists of 44 through-slide spool valves 45-48 connected by means of a line. Each of them has one end control chamber, into which a control pressure is supplied, an inlet and two outlets. FIG. 2, where the actuating valves are represented by standard conventional images, the end chambers are not shown, but only the channels through which the control pressure is supplied are visible. The channels 49–51 end chambers of the valves 45–48 are connected respectively to the outputs of the matching valves 27, 26, 25 and the channel 22 of the selector 17. The inputs of the valves 47 and 48 are connected to the main pressure line 12, the input of the valve 45 to the output of the valve 46, and the output distributor 47 - with the inlet of the distributor 46. The second outputs of the distributor 45-47 channels 52-54 are connected to the hydraulic cylinders 5-7, and both outputs of the distributor 48 are channels 55 and 56 with hydraulic cylinders 8 and 9. One of the outputs of the distributor 45 is not used.

The channels 57-56 can be connected to mechanisms 57 for smoothly turning on hydraulic cylinders of FRICTION CUTS ANY FROM; known designs.

The output of the matching valve 24 channel 58 is connected to the first input of the valve 25.

In the second version of the control system

(Fig. 2) manual control device

performed as controller 59 and block

60 electro-hydraulic pilot valves. Block 60 consists of five identical

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three-way on-off valves 61–65, which can be used in any known device. FIG. 2, by way of example, valve 61 is depicted as a two-ball solenoid valve. Each of them has an inlet communicated with the main pressure line 12, a drain channel and an outlet. The output 66 of the valve 61 is connected to the input of the valve 32 of the automatic control unit 28, the outputs 67 and 69 of the valves 62 and 64. - with the front control chambers of the valves 45 and 47, and the outputs 68 and 70 of the valves 63 and 65 - with the inputs of the matching valves 24 and 26 .

The controller 59 of the manual control consists of five normally open contacts, alternately closed by means of a lever 71 of a known construction, shown simply. Lever 71 has the following fixed positions: 3X1, 3X2,, I, P, A, III, IV. The right terminal of each contact is connected to the input terminal of the coil of the same electromagnet (connecting wires for simplicity are not shown). The left terminal of each contact is connected to one of the poles of the on-board electrical network 72, and these contacts are connected to it through a three-position switch 73 forward (HRP) and backward (SX) stroke. The second pole of the onboard network 72 and the free terminal of each of the coils of electromagnets are connected to ground.

The execution valves of unit 29 in FIG. 2 are similar to FIG. 1, however, their connection between them has been changed to clarify the possibilities of the proposed scheme. It does not use one of the outlets of the distributor 47, and the hydraulic cylinder .5 is connected by channel 54 to the second outlet of the distributor 45. Due to this, to switch on the necessary gear stage 2, the distributors 45-48 must be switched on in a different combination. Accordingly, the number and connection diagram of matching valves decreased (see below).

Block 28 here is similar to FIG. 1, in connection with which he is simplified. Normally off the valve output 32 channel 37 is connected to one of the inputs of the matching valve 25, the same output (channel 38) valve 33 is not used, and the normal output of this valve is similar to FIG. 2 is connected by channels 40 and 41 to the inputs of the matching valves 24 and 26.

These changes made it possible to exclude from the circuit in FIG. 4 matching valve 27 (Fig. 1).

In the third version of the system (Fig. 3), in block 28, the connection of valves 32 and 33 is changed. Here, the inlet of valve 3 by an additional channel 74 is connected not to the outlet of valve 32 as in FIG. 1, and directly with the power source - channel 23,

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coming from the selector 17. In this connection, in addition to matching valves 24–27 of type AND, OR, additionally introduced a matching valve 75 of type HE, in the form of a two-position three-way distributor, the front control chamber of which is connected to channel 37 by channel 37, i.e. with a normally shut off valve 32, the inlet with a channel 38, i.e. with a normally shut off valve 33, and the output channel 77 with the input of the matching valve 27. The remaining elements of the system in FIG. 3 are similar to FIG. one.

The device works as follows.

Work on the neutral. The selector 17 is in the neutral position (I), all the valves 45–48 and the automatic switching valves 32 and 33 are in the position shown in FIG. 1. The input shaft 3 is rotated by a motor (not shown), and a source of fluid pressure

10 through the filter 11 supplies the working fluid under pressure to the main pressure line 12. A constant pressure in the line 12 is maintained by the regulator 13, and the excess liquid is drained into the oil tank. The pressure from line 12 through valve 48 enters the hydraulic cylinder 9. The remaining hydraulic cylinders are connected through a valve 45-47 with a drain. The transmission is neutral.

Work on the automatic mode.

With a stationary car, the selector 17 is set to position "A". The speed sensor pressure 30 is zero. The automatic switching valves 32 and 33 are in the initial position shown in FIG. 1 and corresponding

11 steps. From the selector 17 through the channel 23, the supply pressure is supplied to the input of the valve 32, from its normally on output goes to the input of the valve 33, and from the normally off output of the valve 33 through the channels 40 and 41 through the matching valves 24-26 and channels 51 and 49 goes to face control chambers of distributors 46 and 48. These valves include hydrocyliidr 6 through channel 53 and hydrocyliidre 8 through channel 55, which corresponds to stage II (see Fig. 4). After switching on the second stage, the fuel supply to the engine is increased, and the car starts to move. As acceleration increases, the pressure of the speed sensor 30 increases. At a certain speed, depending on the setting of the spring 35 and the pressure value of the sensor 31 (load magnitude), the valve 33 is activated and switches to the third-stage position. The pressure from its inlet enters the normally off output and then through channel 38 through the adjusting valve 27 enters the end chamber of the distributor 47. Normally switched on

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the outlet of the valve 33 and, respectively, the channels 40 and 41 are connected to the drain, with the result that the valves 46 and 48 are turned off.

Switching valve 33 from one position to another occurs abruptly (without a delay in an intermediate position), since when the pressure is removed from the hydraulic cylinder 36, the spring 35 straightens and its force decreases, breaking the balance of forces on the valve spool.

In the new position of the valve 33, only the valve 47 is in the on position, and from it the pressure flows through the channel 54 into the hydraulic cylinder 5. At the same time, the hydraulic cylinder 9 is turned on through the valve 56 through channel 56. Thus, when the valve 33 is triggered, stage III is activated.

Upon further acceleration, valve 32 is actuated in a similar way and stage IV is activated.

When the driving speed decreases, the automatic control device operates in the reverse order. First, valve 32 returns to its original position and stage III is activated. With further deceleration, valve 13 is triggered and turns on stage II, at which traffic continues in difficult road conditions. If necessary (in rare cases) the inclusion of stage I to overcome obstacles manually by the selector 17 includes stage I (see below).

The speeds at which switchings from stage IV to stage III and from III to II occur during deceleration are lower than the speeds of switchings from III to IV and from II to III due to the hysteresis of valves 32 and 33, provided by a change in the forces of the springs 35 by hydraulic cylinders 36.

If it is necessary to automate the switching of I-II stages, an additional valve similar to valves 32 and 33 can be installed in block 28. If there is a friction clutch in the torque converter 1, it can also be automatically controlled using the same valves. These elements are not included in the scheme to shorten the description, since their design and use is clear from the description of valves 32 and 33.

Work on the first stage.

The selector 17 is set to position "I". Fluid from the inlet line 18 is supplied through channels 19 and 21 through matching valves 26 and 27 to the end control chambers distributors 47 and 48. When the latter is triggered, pressure from the main line 12 through channels 54, 55 is supplied to hydraulic cylinders 5 and 8, which corresponds to stage I (see Fig. 4).

Work on the steps II, 3X1, 3X2.

To enable these steps, the selector 17 is installed in the corresponding

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positions. The inclusion of hydraulic cylinders and actuating valves corresponds to the table in FIG. four.

The operation of the system with electric manual control.

 To activate the desired level of forward or reverse, the switch 73 is set to the position HR or 3X, and then the lever 71 of the controller is set to the position of this level. For example, to turn on stage IV, the lever is moved to position “IV”. This closes the contacts and through them the voltage from the on-board power network is applied to the windings of the solenoids 62 and 63. The armature of these magnets move the balls of their pilot valves to a position where the supply cavity on the side of the ball opposite to the anchor communicates with the output located between the balls. The pressure from the line 12 through the channel 67 is supplied to the valve 47, and through the channel 68 through the matching valves 24 and 25 - to the valve 46, which includes the hydraulic cylinder 6. In addition, through the actuating valve 48, the hydraulic cylinder 9 is turned on, i.e. Stage IV.

Similarly, when the lever 71 is installed in other positions, the remaining steps are included. At the same time, contacts, electromagnetic and actuating valves are switched on in accordance with the table of FIG. 4. When the lever is set to the “L” position, the solenoid valve 61 is turned on, from which the supply pressure is supplied to the unit through channel 66. 28 automatic control .. Automatic switching of the steps occurs as previously described.

As can be seen from the above, the use of an electric remote control with a pilot valve block 61-65 made it possible, with the same composition of the block of the executive valves 29 and the automatic control block 28, to ensure manual activation of all stages, while using the selector 17 of FIG. 1 included only I, II and reverse. The circuit of FIG. 2 has other advantages, which are discussed in more detail below.

To explain the capabilities of this system in FIG. 2 somewhat changed the wiring diagram of the distributors 45-48 without changing their design. Due to this, the number of OR-type matching valves is reduced: in FIG. 2, three instead of four in FIG. 1 despite the increase in the number of stages included manually. At the same time, the order of operation of the actuating valves (see Fig. 4) and the connection of the outputs of the unit 28 with the adjusting valves changed: the normally-closed output of the valve 33 is not used.

Thus, it is obvious that for each particular transmission, such a connection scheme can be chosen

valves to minimize the number of matching valves. However, for some types of transmissions, in addition to the ball valves of type OR, there may be required matching valves of type HE.

Operation of the control system with AND, OR, NOT type control valves.

The operation of this system in the case of manual switching of stages, as well as the operation of valves for automatic switching of stages 32 and 33, is similar to that described with reference to FIG. 1 with the exception of the features of the operation of the AND, OR, and NO type matching valves.

When the controller is set to position “A”, pressure from line 18 through channels 23 and 74 is simultaneously applied to the inputs of valves 32 and 33 and from the normally-connected output to the latter through channels 40 and 41 through matching valves 24-26 is fed into end control actuating chambers " valves 46 and 48. Turns on stage II.

During acceleration, the valve 33 is first triggered, the channels 40 and 41 are connected to the drain, and the channel 38 from the valve 33 through the NOT-type adjustment valve 75, the channel 77, the matching valve 27 pressure flows to the end control chamber of the distributor 47. The latter turns on the hydraulic cylinder 5, and The distributor 48, the end chamber of which is connected to the drain, includes a hydraulic cylinder 9, which corresponds to stage III.

Upon further acceleration, valve 32 is triggered, from the normally off output of which the pressure flows through channel 37 through matching valves 24 and 25 to the actuator valve 46. Simultaneously through channels 37 and 76, pressure from the same output is fed to the front control'camera of matching valve 75, which switches. When this channel 77, reported on stage III with the outlet of the valve 33, is connected with the drain, and the valve 47 is turned off. Since the hydraulic cylinder 9 is still on the valve 48, and instead of the hydraulic cylinder 5, the valve 46 includes the hydraulic cylinder 6, the fourth stage is activated.

When slowing the switch occurs in reverse order.

The device in FIG. 3 corresponds to the general case of using matching valves, and FIG. 1 and 2 - special cases where the scheme can be simplified and dispensed with the minimum number of valves of type OR - without valves of type NOT.

Work at failures of elements of automatic or manual control.

If the valve 33 is stuck in the off position, then when the lever 71 of the controller 59 is installed (Fig. 2) or the selector 17 (Fig. 1) in the "A" position, 761314 turns on

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stump, but no further automatic switching to stage III and IV will occur. However, when the selector 17 is moved to the I, II stage or rearward position, as well as the controller 59 to the I – IV stage or backward position, these stages will freely switch on, because when the unit 28 pressure is removed from channel 23 (FIG. 1) or 66 (fig. 2), the valve 33, separated from the actuating valves of the block 29 by the matching valves 24–27, does not affect the operation of the block 29.

The seizure of the valve 33 in the on position leads to the fact that when the automatic mode is activated, instead of II, stage III will immediately turn on, and then, during acceleration, stage IV. Stage II will not automatically turn on. However, using the controller 59 or the selector 17 II stage and other stages, manual control of which is provided by the scheme, turn on without difficulty, as in the previous case.

Manual control works similarly with other types of failures of unit 28 (valve 32 or valves 32 and 33 simultaneously jamming), although in these cases the behavior of the system after failure is different from that described above.

Failure of one of the actuating valves of block 29 excludes the possibility of using those steps in which this valve is involved. However, the remaining steps can be turned on manually, and in some cases automatically. For example, when the valve 48 is jammed in the on position, the hydraulic cylinder 8 will be permanently turned on (Fig. 1). Stages III and IV will not be activated either manually or automatically (in Stage 2, Stage II is always on), but you can use I, II steps and 13X without difficulty.

It follows from the above that in this system, due to the use of matching valves and other features, the operation of the automatic control and manual control elements is ensured, which increases its reliability. In particular, one of the most important indicators of reliability is significantly improved - survivability, which in this case means the possibility of continuing the movement of the vehicle without eliminating the failure of the control system. The second variant of the proposed system (Fig. 2) has the greatest survivability. Here, even with complete failure of the automatic control unit 28, it is possible to manually switch on any stage manually using the solenoid valves of the block 60 and the block 29. Further, if the solenoid valves 62, 63 fail

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and 65 or the corresponding contacts of the controller 59, you can enable II, III, IV stages using automation (block 28) and valve 61. If valve 61 or the corresponding contact fails, the automation does not work, but all the stages are activated manually. In case of failure of the actuator valves of the unit 29, the system behaves as described above.

Since in operation, as is known from practice, there are mostly single failures, and the reliability of actuating valves is higher than the other elements, this system has a high survivability, i.e. it allows you to continue moving without eliminating any single failure repair). This property is most important for special machines, heavy machines, repair of which is difficult for the crew, and especially for vehicles operated in extreme climatic conditions of the Extreme Sover or heat desert areas away from service bases, where stopping due to faults is associated with a risk to crew life. The prototype system has the worst indicators of reliability, and its survivability is generally very low, since, as already mentioned, the failures of automatic control elements cause it to simultaneously fail manual controls.

It is also obvious from the description of the operation of the proposed system that it can be produced on request with a mechanical remote control (selector 17 in Figs. 1 and 3) or electric (controller 59 and block 60 of pilot solenoid valves in Fig. 2) without changing the block design. 28 (automatic control) and 29 (actuating valves), as well as in automatic (with block 28) and manual (without block 28) variants with both mechanical and electric remote drive, also without any changes in their design. These qualities extend the scope of its application. In addition, they are important in small-scale production, typical for heavy and extra heavy vehicles. The same transmission can be produced, for example, for construction road machines in the command version with a mechanical remote drive, and for tractors and long-wheel-drive vehicles with a non-rigid frame - in the automatic version with an electric remote drive.

Claims (3)

Claim 1. A hydraulic transmission control system for a vehicle comprising a manual control device, 761314 13 having inputs connected to a pressure source and normally off outputs, sensors of rotational speed of the output shaft of the transmission and vehicle engine load, and automatic control device associated with normally off outputs of the manual control device and speed and load sensors for engaging the couplings switching the 'transmission levels of the vehicle 10 by the signals of these sensors, characterized in that, in order to increase reliability by ensuring independent operation The automatic and manual control elements, it is equipped with 15 matching valves, and the automatic control device is made in the form of automatic switching valves for stages with one input communicated with a pressure source, 20 and one normally off output of hydraulically controlled actuating valves having one control chamber on the one hand, with a pressure source, and on the other hand, with gearshift switching sleeves, while the normally switched off valve outputs of the automatic switching and manual control device communicate with the corresponding inputs of the matching valves, and the outputs of the latter are connected to the corresponding control chambers mentioned actuating valves. 2. Hydraulic system in π. 1, characterized in that the matching valves are made of type "And" and "OR". 3. Hydraulic system in π. 1, characterized in that the matching valves are made of type "NOT".