SU1682219A1 - Two-circuit hydraulic automatic control unit for hydraulic and mechanical gearbox - Google Patents

Abstract

This invention relates to transport and may be used to control transmissions of vehicles. The purpose of the invention is to expand the functionality of the hydraulic machine (GA) by using it with

Description

The invention relates to transport and can be used to control the mechanical and hydromechanical transmissions of vehicles, mainly of high unit power and carrying capacity.

The purpose of the invention is to enhance the functionality of a hydraulic machine by using it with gearboxes with both a constant and variable denominator of a number of gear ratios.

FIG. Figure 1 shows the hydraulic scheme of a two-channel hydraulic automatic control unit for hydromechanical transmission; in fig. 2 - schedule of the machine.

Transmission 1 (Fig. 1) consists of a gearbox with 2 gears with hydraulic cylinders 3 of clutches (not shown) and a torque converter 4 with a hydraulic cylinder 5 of the friction clutch. A hydraulic speed sensor 6 is kinematically connected to the input shaft of the 2-speed gearbox. The transmission control system contains a source of fluid pressure 7 (hydrostation) with a main pressure regulator 8, a valve distributor 9, a stepper mechanism 10 for the distributor actuator 9, a two-channel hydraulic automat 11, a command control device 12, an engine load sensor 13 and an actuator valve 14 for blocking the hydraulic transformer. The inlet of the distributor 9 is connected to the main pressure hydroline 15, which is also connected to the device 12 and the sensor 6 and 13. The outputs 16 of the distributor 9 are connected to the hydraulic cylinders 3, and the output 17 of the valve 14 to the hydraulic cylinder 5. The number of hydraulic cylinders

3 depends on the kinematic scheme of gearbox 2.

The automaton 11 contains three two-position five-line distributors 18-20

for switching from lower gears to higher and higher to lower gears, valves OR 21 and 22, power input 23 connected to device 12, outputs for giving signals for switching to a higher gear 24

(Up) and low gear 25 (Down). Each of the distributors 18-20 has two drainage hydrolines, an input supply hydroline, and two inputs - a normally off and normally on, control input. The normally-turned-off output 26 of the distributor 18 is connected to the output 24 of the automaton 11, and the normally-switched output 27 to the power input of the distributor 19. The normally-switched output

28 of the latter is connected to the input of the valve OR 21, and normally off output 29 to the power input of the distributor 20. Normally off output 30 of the distributor 20 is connected to another valve input

OR 21, the output 31 of which is connected to the output 25 of the machine gun 11.

The left end chambers of the distributors 18-20 are connected to the output 32 of the load sensor 13. The right end chambers of the valves 18 and 20 are connected to control inputs 33, which are interconnected and connected to the output 34 of the speed sensor 6 and the input of the valve OR 22,

the output of which is connected to the control input of the distributor 19. Another input to the a-pAN OR 22 is connected to the output 35 of the crane distributor 9. Hysteresis of the characteristics of the valves 18-20

is provided by known devices

containing a hydraulic cylinder for changing the tension of a tuning spring connected to a normally switched output.

The outputs 24 and 25 of the machine 11 are connected to the right inputs of the valves OR 36 and 37. The left inputs of the latter are connected to the outputs 38 and 39 of the device 12, and the outputs 40 and 41 are connected to the hydraulic cylinders 42 and 43 of the stepping mechanism 10 of known construction, which ensures the rotation of the distributor 9 direction from the lowest steps to the highest and back.

The machine 11 may also include a fourth valve 44, the input of which is connected to the normally off output 45 of the distributor 20, the normally off output 46 serves as the third output of the automatic machine 11 which is connected to the torque converter locking actuator 14.

Auto mat works as follows.

Manual control.

In the manual mode, the driver performs any gear changes of the transmission 1 by means of the device 12, from outputs 38 and 39 of which, via valves 36 and 37 through the hydraulic lines 40 and 41, pressurized fluid is supplied to the hydraulic cylinders 42 and 43 of the stepping mechanism 10, which turns the distributor 9 Not a single step in the direction of higher or lower gears.

Moreover, in each of the positions of the distributor 9, the pressure from the hydraulic line 15 of the main pressure is supplied to those of the outlets 16 which are in communication with the part of the hydraulic cylinders 3 corresponding to the selected gear. The remaining hydraulic cylinders are drained at this time through the distributor 9, and the input of the automaton 11 is drained through the device 12.

After each switch, the driver stops sending the command. The hydraulic cylinder 42 or 43 is drained, its piston is retracted to the initial state and prepared for the next actuation.

Automatic control.

To explain the operation on the automatic mode, we first consider the graph of FIG. 2a, which explains the setting of valves 18-20.

The characteristics of each of these valves are depicted in the pressure coordinates of sensors 6 and 13 of speed and load by a pair of straight lines, the angle and distance between which there are valve constants. The valve 18 for switching to higher gears corresponds to direct 47 and 48, and valves 19 and 20 for switching to lower gears correspond to direct 49, 50 and

51, 52. At the same time, the right ones (47, 49 and 51) correspond to the movement of the valve from the left to the right position - to a signal, and the left (48, 50, 52) from the left to the right - 45 disappearance of the switching signal.

At the bottom of the graph, a characteristic 53 of the speed sensor is plotted - the dependence of the pressure at its output 34 on the speed of the input shaft of the 2-gear box,

50 ie torque converter turbine speed 4.

Consider the operation of the machine with an arbitrary fixed value of the pressure sensor 13 load corresponding to

55 of the horizontal line 54, and changes in the pressure sensor 6. At a pressure close to zero, valves 18-20 are in the initial position (Fig. 1). At the same time, the power input 23 is connected to the outlet 27 of the valve 18 and the outlet 28 of the valve 19, and through the OR 21 valve to its outlet 31, which is connected to the outlet 25 of the automatic machine 11. The outlet 26 at this time drains through the valve 18. Thus, this mode, corresponding to the area 55 of the graph of FIG. 2a, the automaton 11 receives the 5H signal of the BH1 to engage the lower gear. At this time, there is no pressure at outlet 29 connected to the inlet of valve 20. When increasing the pressure of sensor 6 to the value corresponding to the point

10 B1, valve 20 moves to the left position, but there is no pressure at its outlets, since there is no pressure at the valve inlet. Increasing the pressure of sensor b to the value corresponding to point B2, clap pan 19 moves to the left position, its output 28 is drained, and the BH1 signal at exit 28 disappears, and at outlet 29 there appears pressure that goes to valve inlet 20. Valve 20 continues to remain in the left position and pressure appears at its outlet 45, and outlet 30 drains. Thus, the HV signal at the outputs 28 and 30 of the valves 19 and 20 is missing, there are also no signals at both the outputs 25 and

5 26 automatic rifles 11.

With a further increase in pressure of sensor 6 to the OT point, valve 18 moves to the left position, its output 26 communicates with input 23 and pressure 36 appears at output 36, which corresponds to the signal B B to turn on high gear. Thus, in the mode corresponding to zone 56, the machine 11 sends a signal BB.

When the pressure of the sensor 6 is lowered, the process proceeds in reverse order. However, due to the hysteresis, the transition of the valves 18-20 to the initial position will occur at lower pressure values. Valve

18 moves to its original position (Fig. 2)

at point H1 and the signal BB disappears. At point H2, valve 19 returns and signals BH1 to engage the lower gear. The low-pass section B2-VZ with an increase in pressure and in the section H1-H2 with its decrease are absent both signals. At the NC point, the valve 20 returns to its original position. But in order for the output 30 of the valve 20 to have a wake-up signal for low gear transmission BH2, it is necessary to force the valve 19 to be turned on so that at its outlet 29 there is a pressure that enters the input valve 20. To this end, the control input of the valve 19 from the crane distributor 9 on certain gears, where a lower gearshift point HH2 is required, is pressurized through the valve OR 22 exceeding the pressure of the speed sensor 6.

As a result, the valve 19 in these gears moves to the left position and at its outlet 29 a pressure appears that goes to the inlet 30 of the valve 20. At the output of the valve 20, a BH2 signal appears corresponding to a lower setting level of the low-level switching machine 11 , defined by zone 57. Thus, two settings of the automaton 11 for switching Down are realized, determined by the characteristic of the valves 19 and 20 and by the commands coming from the crane distributor.

At a different pressure of sensor 13, other than line 54, the device works in a similar way with the only difference that points B1, B2, VZ, H1, H2 and H3 move along line 47-52. These points are projected onto the characteristic 53 of the velocity sensor, and the resulting points of this characteristic onto the turbine velocity axis receive maximum and minimum velocities, in the intervals between which the automaton 11, depending on the pressure of the sensor 13, sends signals BB, BH1, BH2, which is shown in The graphs 2 b, c, d for the fixed pressure of the sensor 13 corresponding to the line 54. The width of the hysteresis loops of the signals BB, BH1, BH2 here corresponds to the values of the hysteresis Gu, HH1. GN2 of valves 18-20. On the graph (fig. 2 e) on the state of the automaton 11 in accordance with the indicated processes it is seen that depending on the ratio of the pressure of the sensors b and 13 it can be in one of three states: high, low gears and neutral.

The automaton 11 provides two levels of BH1 and BH2 for low gears, depending on the ratio of transmission forces of the gearbox to adjacent stages.

In general, the number of different ratios of gear ratios can be more than two. Accordingly, the number of switching levels Down should also be more than two. However, taking into account the fact that for heavy vehicles these ratios can fluctuate outside the range of 1.2-1.8, it is possible to stop at two levels of shifting Down, which provides

0 selection error of switching points Down within the switch by the driver.

Blocking automatic switching to the last stage of explosives and first 5 stages of high voltage can be implemented using various known devices.

Automatic control is performed as follows.

Moving off takes place on the 1st transfer, which is manually activated by the driver from a neutral. After acceleration to the speed at which the transition to the 1st gear is allowed, the driver through the device 12 switches on an automatic mode, at which pressure from the hydraulic line 15 is supplied to the power input of the automatic machine 11. If desired, this can be done at speeds corresponding to the zone between lines 51 and 47, or in zone 56 (Fig. 2a).

0 In the first case, the automaton 11 after switching on is in the neutral state (signals BB, HV are absent), and the transmission remains in 1st gear until the driving speed increases. In the second case

5 immediately after switching on, the automaton 11 sends a signal BB. The pressure from its output 26 goes to the OR 36 valve and further along the hydraulic line 40 to the cylinder 42, which turns the valve 9 one step in the direction of the top gear, i.e. in the position of the fifth gear.

Since the gear ratio of the ith scroll is less than the 1st one, and the speed of the machine changes little during the switching time, the speed of the torque converter turbine decreases in proportion to the ratio of gear ratios ii / in. Accordingly, the pressure of the sensor 6 also changes. As a result, the automatic machine 11 moves from the zone 56 to the left, and is obviously to the left of the line 48. The signal BB disappears and the car moves in I-th gear. In the future, the car can continue to accelerate or slow down, depending on the driver’s desire and conditions.

5 movements.

In the first case, the pressure of the sensor 6 increases again and when the values corresponding to line 47 are reached, the automaton sends a signal to the explosive, which leads to switching on of the 2nd 1st gear. In the second case, the pressure

falls, when it falls to line 52, the valve 19 returns to its initial state under the action of a return spring and a HV signal appears at the output of the automaton 11. That leads to the inclusion of the 1st gear

Towards the end of the 1st gear, the speed of the turbine of the hydrotransport 4 increases in proportion to the ratio of the gear ratios, and the pressure of the sensor 6, respectively, increases. As a result, the automaton moves to the zone of operating modes, which lies obviously to the right of line 51, and the VH1 signal will disappear. The car is moving in 1st gear.

For those gears where a lower level is required is switched according to the ratio of gear ratios. BH2, valve 20 is used. In this case, the valve 19 for receiving BH1 signals of a higher level is blocked by shifting it to the far left position.

For example, if a lower switching level is required for switching from III to II-nd gear than for other gears, in this case, when the car moves to M-th gear, pressure from outlet 35 of distributor 9 is constantly applied, which through valve OR 22 enters the control input of the valve 19, as a result, the latter is set to the left position. The output 29 of the valve 19 is connected to the power input of the valve 20. Thus, it is impossible to output the HH1 signal at the output 28 of the valve 19. In this case, switching to a lower stage might v effected only via the valve 20 at the onset of its output signal 30 BH2. At the same time, in the process of moving the machine at the B-th stage in the velocity zone, in section B1-VZ, there are no switching signals to the highest stage, and in section H1-NC, to the lower stage (Fig. 2a).

Thus, at any other stage, a lower level of shifting Down can be set by the distributor 9, and the machine can switch any number of gears without introducing any additional elements and be used in both hydromechanical and purely mechanical transmissions.

The torque converter A in the hydromechanical transmissions of these machines has a friction clutch, which should turn on automatically. To this end, the machine 11 may additionally have an automatic locking valve of the torque converter 44, which is identical in design to the valves 18-20.

It is advisable to block the torque converter on the r. Hey transmission in the zone of speeds in which switching to the next lower or higher one is not required. This zone (Fig. 2a) lies between lines 47 and 51. Accordingly, valve characteristics 58 and 59 are located in this zone 5 44. In addition, for any gear changes, the torque converter must be forcibly unlocked. This is achieved by the fact that the power input of the valve 0 of the valve 44 is connected to the normally off output 45 of the valve 20.

As a result, the supply pressure to the valve 44 comes only when the valve 18 is still in the right position, and the clamps 5 and 19 and 20 are already in the left, i.e. when there are no signals BB, BH1, BH2 at the outputs 25 and 26. Simultaneously with the signal BB (valve 18 to the left), the power supply of valve 44 drains through it and the blocking signal at output 46 disappears, the same happens when BH1 signals are applied, BH2 (return valves 19 and 20 to the right in the position of Fig 1).

The automatic control of the friction lock is carried out as follows.

When operating in automatic mode and accelerating at any stage, the torque converter is unlocked until its turbine speed measured by sensor 6 increases to the value corresponding to line 59 (Fig. 2a). At this moment, the valve 44 switches from the initial position (Fig. 1) to the right and the pressure from the 5 inlet feeds it to the output 46 and then to the blocking actuator 14, which supplies pressure to the hydraulic cylinder 5. If the speed then decreases, then valve 44 returns to its original position and pressure at outlet 45 disappears. If acceleration continues with a locked torque converter, then when the mode corresponding to line 47 is reached, the machine issues a 5 V signal and the pressure at outlet 46 is relieved in this way.

Claims (1)

Claims of the invention A two-channel hydraulic automatic control unit of a hydromechanical transmission, comprising automatic control valves made in the form of two-way five-line distributors having an inlet, two drainage, as well as normally-on and 5 normally-off output hydrolines, and having an input for supplying pressure, the first and second outputs for supplying signals to gearshifts from lower gears to higher gears and from higher to lower gears, a control input for communication with a sensor the vehicle speed, which combines the control inputs of the valves, with the input of the first valve communicating with the input of the automaton, and the input of the second valve with the normally-activated output of the first valve, with the normally-off output hydrolines of the first valve and the normally activated output hydroline of the second valve communicating respectively the first and second outputs of the machine, characterized in that, in order to extend the functionality by using it with gearboxes with both constant and variable m is the denominator of a number of gear ratios, it is additionally equipped with a third automatic control valve, similar to the first and second and two OR valves, the third valve inlet communicating with the normally off second line hydroline, normally connected output lines of the second and third 1 valve interconnected by means of one of the mentioned OR valves. the output of which is connected to the second output automaton, and the second of the mentioned valves OR is connected by its one input to the control input of the first valve, the output to the control input of the second valve, and the second input of the specified valve OR is designed to be connected to a crane stage switching distributor. 20 -47 2