• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a braking force modulator for an anti-lock system for pneumatic brakes for vehicles in which a hydraulic circuit accomplishes the anti-lock function. A sensor sensing the state of rotation of a wheel emit signals for controlling a modulator valve (34) which, in response to such signals modulates the pressure in one or more counter-pressure cylinders (27). A closing valve is inserted into the pressurized-air conduit (4) between the control valve (5) for the brake operated by the driver and one or more braking cylinders (8) and this closing valve closes the pressurized-air supply to the braking cylinder or cylinders (8) subsequent to a sensor signal ordering release of the brakes. A release valve is inserted into the pressurized-air conduit (4) between the closing valve and the braking cylinder or cylinders (8) for discharging pressurized air therefrom if the ability of the pressure producer (13, 26) for the hydraulic fluid pressure and of the counter-pressure cylinder (27) to continue the release of the brake is exceeded.
    公开号:SU1321368A3
    申请号:SU843859907
    申请日:1984-10-30
    公开日:1987-06-30
    发明作者:Ивар Бломберг Фольке；Мартин Хольст Ян-Олов
    申请人:Фольке Ивар Бломберг и Ян-Олов Мартин Хольст (SE)；
    IPC主号:
    专利说明:

    1h:
    valves connected to the brake valve 5. The collector chamber 33 of node 7 is connected on one side to the chamber 30 of the hydraulic cylinder 27, and the other side through the modulating valve 34 and the check valve 36 to the inlet valves 37, 38 of the hydraulic pump 13. To the exhaust valves 39, 40 cylinder 30 is connected to chamber 27. The modulating valve 34 is pneumatically controlled by compressed air from receiver 3
    one
    The invention relates to anti-lock braking systems of automobiles, namely to braking force modulators.
    The purpose of the invention is to increase reliability.
    FIG. 1 is a schematic diagram of the braking force modulator; in fig. 2 - piston pump, slit; in fig. 3 is a section A-A in FIG. 2; in fig. 4 is a section BB in FIG. 3; in fig. 5 - modulating valve; on fi1. 6 - part of the modulating valve, in FIG. 7 - pressure reducing valve that maintains a constant pressure in the hydraulic tank cavity, a section; in fig. 8 - valve assembly with shut-off and discharge valves; in fig. 9 - brake force modulator, option; in fig. 10 is a graph of current I in time T for controlling a solenoid 1m valve; in fig. 11 - modulator, general view.
    The modulator (Fig. 1) contains a pneumatic and hydraulic systems. FIG. 1 and 9, pipelines for air and air are shown by dashed lines, and hydraulic pipelines are shown by dash-dotted lines. The pneumatic system contains a compressor 1, which is connected via pipe 2 to receiver 3 for compressed air, and pipe 4 leaves the receiver, which through brake valve 5 connected to brake pipe 6, actuated by the warrior, goes to valve assembly 7, from there, to the brake chamber 8. Brake
    by means of a solenoid valve 50. A solenoid valve 50 is included in the electrical circuit of the wheel dynamic sensor. When current is applied to the solenoid valve 50, the modulating valve 34 changes the pressure of the fluid in the chamber 30 of the hydraulic cylinder. A change in pressure in chamber 33 leads to a change in pressure in chamber 8, thereby controlling the braking force. 5 hp f-ly J 11 ill.
    chamber B contains a membrane (not shown), from which the movable push rod 9 extends outside through the wall of chamber 8 to the wheel
    brake mechanism 10 s brake lever ohm 1 1. When compressed air is supplied to the brake chamber 8, the rod 9 is pressed to the left (in Fig. 1), i.e. inhibition occurs. After the compressed air has been released, the rod 9 is returned to its original position by means of springs or the like. (not shown).
    The brake force modulation system contains a hydraulic tank 12 for a fluid in which the fluid, and therefore the entire hydraulic system, is under a pressure of 1-3 bar. As a result, firstly, the operation of the piston hydraulic pump 13 will become more efficient and reliable, because it avoids cavitation in its intake valves, and secondly, this pressure ensures that the system is removed from the system. The creation of this pressure is ensured by T by supplying compressed air through the pipeline 14, which enters the hydraulic tank 12 through the pressure reducing valve 15, combined
    with a safety valve (a so-called valve for maintaining a predetermined pressure). Fig. 1 shows the modulator in a state where its components are in the position before pressure is applied to the hydraulic tank 12. When compressed air is supplied through pipe 14, air passes by the seat 15 of the valve 15 and the valve cone 17 and through the channels
    18 and 19 goes to the hydraulic tank 12. When / the pressure in the hydraulic tank 12 rises to a predetermined value, the force acting on the membrane 20 overcomes the force of the springs 21, as a result of which the valve cone 17 moves up to the saddle 16 and the pressure build-up in the hydraulic tank 12 stops. Since it is not always possible to be sure of the absolute tightness of the seal between the valve cone T7 and the seat 16, the valve 15 to maintain a predetermined pressure is equipped with a conventional safety valve containing a seat 22 made in the valve body 15, the ball 23 and the spring 2 4. Adjustment of this safety valve ultimately determines the amount of pressure applied in the hydraulic cylinder 12. From hydraulic tank 12, hydraulic pipe 25 goes to hydraulic pump 13, which is activated by means of electric motor 26, and from it further to discharge. hydro-cylinder. 27, in which a piston 28 fitted with a push rod 29 is slidably mounted. The piston 28 divides the internal cavity of the hydraulic cylinder 27 into two chambers 30 and 31, in one of which (30) pressure can be applied to provide a counter brake force created by the brake chamber 8. Camera 31 communicates with the atmosphere.
    From the chamber 30 in the discharge cylinder 27 departs hydraulically pipe 32, leading to the collector chamber 33 in the valve block 7 and from there to the modulating valve 34 with pneumatic servo-control, from which back to the hydraulic tank 12 leads the pipeline. 35. A return valve 36 is integrated in the pipe 35 between the modulating valve 34 by the hydraulic tank 12. Its purpose is to make the system self-batching (with automatic venting) that is achieved in two ways.
    If there is no fluid in the whole system, for example, when it is fresh. when the hydraulic tank 12 is filled with a liquid under the force of gravity and under the condition that the hydraulic pump is located below the hydraulic tank 12, flows down the pipeline 25 to the inlet valves 37 and 38 of the hydraulic pump 13, but the hydraulic pump
    during start-up, the electric motor 26 does not work due to air trapped in the cylinders. Pumps of this type, having small working volumes of cylinders and necessarily relatively large harmful spaces, are not self-flowing. When pressure is applied to the hydraulic tank 12 through the valve 15 to maintain the specified pressure, the check valve 36 prevents the pressure from the hydraulic tank 12 through the pipeline 35 to the modulating valve 34 and further through the pipeline 32 and the valve assembly 7 to the chamber 30, and from there to the exhaust valves 39, 40 the hydraulic pump 13, on the contrary, the XKA- bone is displaced from the hydraulic tank 12 through the inlet and exhaust valves 37-40 of the hydraulic pump 13 and through the pipe 41 into the chamber 30 until the pressure determined by the valve 15 spreads throughout the system. When this occurs, effective pumping (air removal) from the pump, as well as chamber 30 (at least partially, depending on the volume of the pipeline 35), the collector chamber 33 in the valve assembly 7 and the space in the modulating valve 34. The pump is now ready for pumping bringing the system into action, and a small amount of air that could be trapped in chamber 30, would only cause some deceleration of the first and possibly one or two subsequent control cycles, after which the air would be removed from the entire system. This means that the air from the hydraulic pump 13 will be removed even when the pump is installed above the hydraulic tank 12.
    The check valve 36 performs the function of de-airing and otherwise. The pipes, together with the hydraulic tank 12, the intake and exhaust valves 37-40 of the hydraulic pump 13, the check valve 36 and the chamber 30 form a closed loop in which the cylinder 27 with the chamber 30 and the piston 28 is a pump in it as inlet valves and inlet valves 37-40 of the hydraulic pump 13 and, as an exhaust valve, a non-return valve 36. The piston 28 moves with each normal braking, i.e. with each brake, the fluid in the circuit moves,
    which ensures continuous pumping of the entire system.
    The conventional pneumatic brake system shown in FIG. 1 and 9, operates as follows. When the driver presses the brake pedal 6, the valve 5 opens and the compressed air flows from the receiver 3 through the valve assembly 7 through the pipe 4 into the brake chamber 8. The pressing rod 9 moves outward and turns the lever. 11 on the braking mechanism 10, causing braking. In a conventional pneumatic braking system, the pressure of the compressed air is about 7 bar.
    A sensor (not shown) senses the state of rotation of the wheel being braked. If the braking force becomes greater than the permitted adhesion of the wheel to the road surface and if the wheel tends to block, the sensor sends a signal that, firstly, causes the hydraulic motor 26 to start the hydraulic pump 13 5i, and secondly, causes the modulating valve. FOR interrupt the flow of fluid created by the hydraulic pump 13.
    The modulation valve 34 contains two normally open valves 42 and 43. with return springs 44 and
    45 respectively. These valves are actuated by a membrane.
    46 and the balancing spring 47 through the pusher 48, the spike 49 of which passes through the valve 42 to actuate the valve ball 43. The space under the membrane 46 is usually in communication with the atmosphere through the solenoid valve 50 containing the core 51, which is the movable part of the two valves, located at opposite when receiving a signal from the sensor, the current is applied to the electric motor 26 and the solenoid valve 50 as a result of which the core 51 rises and opens the opening of the lower valve and closes the opening in the top valve. At the same time, the connection between the submembrane chamber and the atmosphere is interrupted by the pipeline 52
    compressed air enters the chamber.
    As a result, the pusher 48 moves in an upward direction (in FIG. 6
    causes the closure of the first valve 42 and valve ball 43 immediately after it. Now when the electric motor 26 is started and, consequently, the hydraulic pump 13
    the brake release starts due to the fact that the hydraulic pump 13 begins to raise the pressure of the liquid in the chamber 30 of the discharge cylinder 27. When taken from the command sensor
    again start the braking; the current supply to the motor 26 is stopped; whereby the hydraulic pump 13 is stopped. The current supply to the solenoid valve 50 is also stopped,
    5 which causes the core 51 to move back to the lower position, reestablishing the connection of the submembrane chamber with the atmosphere and interrupting the supply of compressed air through pipe 52. The membrane 46 and the pusher 48 are driven down by the action of the spring 47. At that, the ball valve. 43 opens, but the force of the spring 47 is not enough to open the large valve 42 due to the increased movement during the release. This provides a soft controlled brake. life without jerks. The speed of braking can be like
    the wound by appropriately fitting the diameter of the hole in the valve 42 and the diameter of the spike 49 passing through the hole to actuate the valve ball 43.
    To open the large valve
    42 it is necessary for the fluid pressure to drop to a few bar, which usually never occurs during braking, controlled by
    system if the driver does not finish braking by releasing the brake pedal. Thus, during the braking operation, by means of the system, it will open and close,
    as a rule, only valve ball 43.
    When the sensor sends a signal indicating that the wheel is too slow, the valves 42 and 43 of the modulating valve 34 close and the hydraulic pump 13 starts working at the same time, pumping liquid into the chamber 30 in the discharge cylinder 27. The pressure acting on the piston 28
    the cylinder rises and, when it becomes sufficiently high, the piston 28 moves towards the brake chamber 8 and the braking force decreases. The sensor all this time
    perceives the state of rotation of the wheel being braked and, depending on this condition, sends signals for opening and closing the valve 43 and turning on and off the engine 26 and, consequently, the hydraulic pump 13. It has been established that a suitable pressure of the fluid coming from the pump is about 80 bar, even if the pump may be able to create a higher pressure. It has also been found that a suitable engine is an engine with a starting power of 350 watts. After starting the engine, the required power is reduced to about half of this value and, since. during braking, it should be noted that the pressure in the hydraulic valve 12, the atmospheric pressure and the air pressure in the internal system through the system also affect the operation of the two valves 53 and 54, the duration of the brakes and braking periods is approximately the same 20 of the core of the valve assembly 7. The dist. Power requirement is approximately 00 W on the side opposite to that. This applies to very strong brakes, such as rear axle brakes on very heavy trucks. For the front wheels
    25
    on which the hydraulic pressure acts on the pistons 55 and 58, communicates with a hydraulic tank 12, in which a pressure of 1-3 bar is adjusted. This pressure is completely balanced and does not create any force acting on the piston 58. On the contrary, the force applied to the valve 53 is influenced by the force corresponding to the force exerted on the piston 55 by the hydraulic pressure.
    of the same trucks, the power requirement is only about half that value.
    The fluid pressure in the chamber 30 of the discharge cylinder 27 is transmitted through conduit 32 to the collector chamber 33 in the valve assembly 7, which in turn controls the air pressure in the brake chamber 8 during deceleration. Node 7 contains a shut-off valve 53 (FIG. 8), which interrupts the supply of compressed air to the brake chamber 8 through line 4, when the pressure in the collector chamber 33 exceeds the set value by adjusting it. It is in the range of 4-7 bar. This means that further control of the braking force is assumed by the braking force modulator for a period while the hydraulic pressure in chamber 33 is above the adjusted value of 4-7 bar for valve 53
    If the pressure in chamber 30 rises above a higher value, for example 80 bar, i.e. the value for which the hydraulic pump 13 is designed, will open the unloading valve 54 in the valve assembly 7 to release compressed air from the brake chamber 8 through the opening in the valve body 7 of the control.
    213688
    The two valves 53 and 54 (FIG. 8) are controlled by the hydraulic pressure supplied to the collector chamber 33, the pressure being
    5, the valve 33 closes, is determined by the mutual ratio between the area of the piston 55 and the spring force 56. The force from the piston 55 is transmitted to the valve 53 by means of the boiler 57. Similarly, the pressure at which the valve 54 must open is determined by the mutual ratio between the area of the piston 58 and spring force 59..
    15 It should be noted that the operation of the two valves 53 and 54 to some extent is also affected by the pressure in the hydraulic tank 12, the atmospheric pressure and the air pressure in the internal cavity of the valve assembly 7. The space opposite to the side of the valve assembly 7. A pro-country on the side opposite
    on which the hydraulic pressure acts on the pistons 55 and 58, communicates with a hydraulic tank 12, in which a pressure of 1-3 bar is adjusted. This pressure is completely balanced and does not create any force acting on the piston 58. On the contrary, the force applied to the valve 53 is influenced by the force corresponding to the force exerted on the piston 55 by the hydraulic pressure.
    0
    This force created by the pressure in the vacuum tank 12 acts on a surface whose area is equal to the difference between the cross-sectional areas of the piston 55 and the pusher 57. In addition, the pressure 57 is affected by air pressure in the valve assembly 7 in the direction opposite to the force of the hydraulic valve. The pressure on the piston 55. When the valves 53 and 54 are closed, the air pressure drops on both their sides create a force that tends to keep them closed, resulting in some hysteresis, a difference in the hydraulic pressure at which the valve opened and closed.
    However, the effect of different air pressures is of secondary importance, firstly, because the air pressures are low compared to hydraulic pressures, and, secondly, because it is not difficult to balance the mutual relationship between the respective cross-sectional areas and the springs 56 and 59 to
    0
    five
    91
    The effect of air pressure forces on the function of the valve assembly 7 was completely insignificant.
    Thus, by means of the valve assembly 7, pressure in the hydraulic and pneumatic systems is balanced, as a result of which the hydraulic pump 13 is never necessary to work, overcoming the maximum pressure that the pneumatic system can create, and only needs to overcome the maximum pressure allowed by which the valve assembly 7 and which is still under all conditions sufficient to provide maximum braking effect without locking the wheels. Since the actual exhaust part of the brake system is actuated by hydraulic fluid, all pressure is transmitted almost instantaneously, so the system operates at a relatively high frequency (up to 7-8 Hz), due to which the braking applied in practice occurs evenly and strongly without the inclination of the controlled wheels to lateral slip.
    During a braking process, air release usually takes place only at the beginning of the process. All subsequent regulation of the braking force is made only with the help of the hydraulic system, at least, if the conditions on the roads are constant.
    When the road conditions change during a braking process controlled by a system with a wheel sensor and a braking force modulator, it may happen that, due to a sudden deterioration of the road condition, another air release occurs, and vice versa, with a sudden improvement of the road condition, an increase in braking force require additional air from the brake system receiver, which happens if the hydraulic pressure drops below 4-7 bar, above which the valve 53 closes.
    Typically, the air brake during braking has a significant dead stroke, which means that the rod 9 must travel a fairly long distance before the brake pads come into contact with the brake drum. Usually in drum brakes of trucks the length is half 810
    The piston shaft of the rod 9 is higher than 50 mm, of which AO mm is a dead stroke and only 10 mm is the distance that passes from
    the moment of the first contact between the brake pads and the drum until the moment of complete braking.
    Under some conditions, this may lead to a lack of system efficiency. For example, during heavy braking at a very slippery road, it may happen that the rotation of the wheel will be slowed down to such a low speed relative to the speed
    vehicle movement, which will require MHoi o time to reverse its acceleration so that the sensor stops giving the command for disinhibition. In this case, the modulator can act
    so it’s about duty that not only ensures complete disinhibition, but also forces the brake pads to go far in the backlash area. In subsequent commands from the sensor to perform a re-braking, it will be necessary to select this dead stroke before the brakes again take effect. Obviously, this will lead to a loss of time, a decrease in the operating frequency of the system and,
    hence 5 of its effectiveness.
    In cases, it may be permissible to release the brake by means of the modulator to the backlash area, but for some cars it is important
    so that this deficiency is eliminated. For this purpose, a valve is inserted into the system; a pneumatically controlled shut-off valve 60 is inserted, which is integrated between chamber 31 in cylinder 27 and pipelines 61.
    and 25 leading to the hydraulic tank 12. The valve 60 is actuated by supplying through pipeline 62 of the same air pressure that is supplied to the brake chamber 8 when decelerating,
    The valve actuator includes a diaphragm 63 and a return spring 64.
    In extreme conditions, for example, when a car with a strong
    with braked wheels, it moves along a road in a good state and suddenly gets into a section of the road that is in a very bad state; the speed of rotation of the wheels can quickly fall to almost a complete stop. In this case, the wheel sensors will signal the modulators, ordering them to release the brake, but due to poor wheel adhesion
    П 132136812
    with the road surface, the speed of the wheel puck's significant forces, despite the full friction, includes only the force from hydrostatic braking, so increases the speed of the 27 and the brake chamber 8. Referentially and therefore the signals of their wheel system with the specified - sensors for so long that the modulators adjust the modulators to brake when fluid pressure in the chamber is not only in the backlash area, 30 of the hydraulic cylinder 27, but up to the mechanical end 80 bar, overcoming It is force sozdava- stop. Consider a wheel with a braking brake chamber 8 at a pressure, a wheel sensor and an air modulator of 2 bar, then it is possible to establish that the hydraulic pressure in the brake chamber-8, when the pressure in the valve assembly 7 has decelerated from contact to high already before reaching the brake with the brake drum, it was off-duty mechanical, it was poured by means of a valve assembly that the valve 53 was closed and that after reaching J5 7 up to 2 bar. From this state of modulation by brakes, the limiter stop continues to produce liquid thrust — the pressure quickly raises the lubrication in the direction of the mechanical to O1, which is limited by the overflow clap of the end stop of the brake, by means of the hydraulic pump 65 however, it never reaches, much higher than the value, at 20 because earlier this valve which opens the valve 54 c. the valve 67 opens the switch, in the pan assembly 7, caused the pressure which caused the signal from the co-air in the brake chamber 8 of the fast forest sensor to the modulator to stop flowing to atmospheric. As a result, the braking phase of this re-braking begins at the end of 25 under the action of air pressure (2 signal of the wheel sensor is very med-bar), isolated in the braking distance. In addition, a compressed airbox 8 is lost. When this phase of repeated braking is achieved, a movement sufficient to ensure that, in order to prevent this, electrically drive means 67 again the locking circuit between the wheel sensor - Dudd switch -66, the switch is inserted again and the switch is inserted into the modulator, the action is a modulator. This sequence is driven by the displacement of alternating inclusions and neither in the drive mechanism of the brake. The modulator shutdowns are repeated with. In FIG. 1 shows a switch 66 at a relatively high frequency, which is re-installed on the brake chamber 8, as a result of which there is a rapid return and a drive from the actuating mediol-translational motion of a thickness of 67 attached to the pusher cattle 9, 29, the brake lever 11 9. In FIG. 1 the brake is shown in the state of the details in the brake mechanism 10 of the scientific research institute of complete disinhibition, at 40 (not shown) until the wheel, the pusher 9 and the brake lever, the sensor ceases to flow sig-11 to the right (Fig. 1) to nala. During all this time, the fixed stop either in the air brake pressure (2 bar), insulated chamber 8, or in the brake mechanized in the brake chamber 8, is ready 10. In this position, the switch 45 begins to restart braking, like 66 open As soon as the wheel sensor stops braking, only the pusher 9 moves to give a signal, a short distance to the left (in FIG. 1),
    the drive means 67 comes out. When braking is not performed, the switch 60 is in contact with the switch 66, the valve 60 is open and the entire system is in the result of which the switch is closed in the filling state is liquid. If the modulator is under the influence of gravity by a force of gravity for a very long time for the signal of the wheels all the way from the hydraulic tank 12. The remote sensor tries to clear air at the newly installed braking point The brake system, the brain pads just filled out of the contact with hydraulic fluid, is accelerated with the brake drum, into the balance of forces by creating movements in the system, besides minor braking forces. For each brake, there can be from return springs no brakes found lee, at which the brake13132136814
    1-3 bar, under which the hydraulic system is constantly located. Switch 70 is built into the electrical circuit between the wheel sensor and modulator 5 and acts similarly to switch 66, except that switch 66 allows the modulator to release the brake to a point close to the mechanical end stop of the brake, while switch 70 allows It does not allow the modulator to release the brakes with a small exit to the dead-run region.
    The valve 60 does not open until, since the driver additionally releases the brake pads, they begin to come in contact with the brake drum. The return spring 64 is adjusted with respect to the membrane 63 so that the valve cone 68 fits tightly into the seat 69 at this pressure. Under normal braking during a dead stroke, fluid is sucked into chamber 31 from hydraulic tank 12 through valve 60. When brake pads reach the brake drum, valve 60 closes the connection between hydraulic tank 12 and chamber 31. With continued braking, the volume of chamber 31 increases by the fluid cannot enter the chamber 31, it creates a negative pressure, which causes the formation of a large number of bubbles filled with vapors of light fractions of hydraulic fluid. With the subsequent release of this, the volume of chamber 31 is again reduced and the volume of bubbles also decreases. When the brake pads come out of contact with the drum, the air pressure in the brake chamber and on the diaphragm 63 in valve 60 is reduced to the value at which valve 60 opens again. The 8 t brake chamber does not have the pushers 9 and 29 to the stop (stop) position, with the fluid being forced back into the tank 12.
    If, however, when braking, the sensor signal causes the modulator to act for such a long period of time that it produces a complete release and attempts to press the brake pads into the backlash region, valve 60 will not open, and the air pressure in the brake chamber 8 will not open during the process braking j controlled by the modulator is not reduced to the required low pressure. The gas bubbles are condensed, and the volume of fluid enclosed in chamber 31, of which the piston 28 forms one wall, will certainly stop further movement into the backlash region.
    A switch 70 (Fig. 9) is connected to the cylinder 31 and communicates with the chamber 31. It is activated by means of the hydraulic pressure in the chamber 31, which is normally closed, but opens at higher pressures.
    distance
    FIG. 11 shows a compact embodiment of a modulator made from cast parts of a rational shape. The device contains all the elements shown in FIG. 1 and 9, with the exception of those that are integral parts of the pneumatic braking system itself, i.e. compressor
    25 j receiver 3, brake pedal 6, brake valve 5, brake chamber 8 and the actual brake mechanism 10 with the lever 11. Of the modulator elements are not shown in FIG. 11 only
    30 cylinder 27 and valve 60. It should be noted that most of the pipelines, which in FIG. 1 and 9 are shown, respectively, with dashed lines (compressed air) and with dash-dotted lines.
    35 lines (hydraulic fluid), in the modulator of FIG. 11 made in the form obtained by casting or drilling channels
    40
    45
    50
    55
    Sealing elements, such as o-rings, on pistons exposed to high pressures do not cause very large losses. friction. Therefore, the pistons 71 in the hydraulic pump 13 (Fig. 2 and 3) are not sealed. They enter cylinders with a very small gap (a few hundredths of a millimeter). During the work of the hydraulic pump. 13, a small amount of liquid seeps into the space where the eccentric 72 is placed. Through the drilled channel this space is communicated with the hydraulic tank 12, where the leaked oil is returned. The cavity for the eccentric 72 in the housing 1 of the idropump 13 is sealed from the electric motor 26 by means of a very powerful sealing element 73J which with a large margin
    distance
    FIG. 11 shows a compact embodiment of a modulator made from cast parts of a rational form. The device contains all the elements shown in FIG. 1 and 9, with the exception of those that are integral parts of the pneumatic braking system itself, i.e. compressor
    j receiver 3, brake pedal 6, brake valve 5, brake chamber 8 and the actual brake mechanism 10 with the lever 11. Of the modulator elements are not shown in FIG. 11 only
    cylinder 27 and valve 60. It should be noted that most of the pipelines, which in FIG. 1 and 9 are shown, respectively, by dashed lines (compressed air) and in phantom
    lines (hydraulic fluid), in the modulator of FIG. 11 made in the form obtained by casting or drilling channels
    Sealing elements, such as o-rings, on pistons exposed to high pressures do not cause very large losses. friction. Therefore, the pistons 71 in the hydraulic pump 13 (Fig. 2 and 3) are not sealed. They enter cylinders with a very small gap (a few hundredths of a millimeter). During the work of the hydraulic pump. 13, a small amount of liquid seeps into the space where the eccentric 72 is placed. Through the drilled channel this space is communicated with the hydraulic tank 12, where the leaked oil is returned. The cavity for the eccentric 72 in the housing 1 of the idropump 13 is sealed from the electric motor 26 by means of a very powerful sealing element 73J which with a large margin
    Holds a pressure of 1-3 bar, under which the entire hydraulic system is located. The leakage-induced volumetric throughput capacity (about 10% of pump performance) is significantly lower than with sealing elements, such as O-rings, on pistons x.
    The pistons 55 and 58 in the valve assembly 7 (Fig. 8) also do not have any sealing elements for retaining the fluid. A small amount of fluid seeping past the pistons returns through the holes in the valve block body 7 to the hydraulic tank 12 through the corresponding holes in it. This is easy to do because the valve assembly 7 is screwed directly to the hydraulic tank 12. On the piston 58 and the pusher 57, sealing rings 74 and 75 (respectively) of circular section are provided. They are not subjected to a hydraulic pressure of 80 bar. The sealing ring 75 is only subjected to a pressure of 1-3 bar, under which the entire hydraulic system is located, and the same pressure acts on. the sealing ring 74, except for the braking moments, when one side is affected by a pressure of 1-3 bar, and the other is by the air pressure supplied to the brake chamber 8 when braking.
    This avoids a large hysteresis effect (lag) that would otherwise disrupt the operation of the valve assembly 7.
    The design of the hydraulic pump 13 (FIGS. 2 and 3), which is essentially a traditional eccentric driven piston pump with automatic spring-loaded intake and exhaust valves, differs from the design of traditional pumps of this type in one important respect. In conventional pumps, the flat ends of the pistons abut against an eccentric ring, the outer surface of which is cylindrical. If the pump has only one cylinder, then the relative movement between the piston and the eccentric is pure rolling. If the pump has more than one piston, then between the end faces
    five
    0
    five
    five
    Q
    Q
    0
    the bones of the pistons and the eccentric slip occur, leading to wear and a large 1 m of friction, firstly, on the contact surfaces between the pistons and the eccentric and, secondly, between the pistons and the cores due to the large transverse forces acting between pistons and cylinders.
    The design of the hydraulic pump modulator eliminates these drawbacks. The ends of the pistons 71 facing the eccentric ring 76 (FIG. 2) and the outer surface of the eccentric ring 76 are made with spherical recesses of a slightly larger radius than the balls 77 inserted into these recesses between the pistons 71 and the eccentric 72. Slip between the pistons 71 and the eccentric 72 is replaced., Thus, by pure rolling, and calculations confirmed by practical tests have shown that the efficiency increase is about 40%. This is one of the reasons for the very low power requirement. The rest of the pump has a traditional design. Piston m 71 communicate oscillatory (reciprocating) movement through an eccentric mechanism containing an eccentric 72, made in one piece with the shaft of the electric motor 26, needle bearing 78, eccentric ring 76 and balls 77. Check valves 37-40 also have a traditional design, containing coil springs, valve cones and seats. Flat valve cones were selected for the inlet valves 37, 38, and balls for the exhaust valves. Hydraulic pump 13 bypass valve 65 also has a traditional design and contains a seat made in one piece with the pump casing, a ball and a supporting device for supporting the spring, installed in hydraulic pump housing.
    It is very important that the solenoid valve 50 (Fig. 5) reacted very quickly to the signal from the sensor, both when the core is attracted, when the current is applied to the solenoid, and when the core is released, when the current is supplied to the solenoid. As a rule, it is not difficult to provide fast attraction — all that is needed is to use only sufficiently strong solenoids with a large number of amperswitches. Harder
    to ensure the release of the core 51 when the current supply is stopped, and the harder it is, the stronger the magnetic flux created by the solenoids.
    Below are three options for devices that provide a solution to this problem. FIG. 10 shows the dependence of the current strength I on time T. The common feature of these three devices is the use of a very powerful solenoid, in which a very large current can be provided if you allow a selected network voltage to operate for a sufficiently long period of time. Such a process is shown in FIG. 10 thick solid line (a).
    According to one method, an electrical resistance (resistor) is installed in series with a solenoid valve 50. The resistance is shunted by a transistor to short-circuit the resistance when receiving a control signal. This control signal is developed by an inductor coiled around the same frame that the coil is wound on. valve 50.When current is supplied to the solenoid valve 50, it passes at the initial moment through resistance. This is shown in FIG. 10 by dash line O - a. In this case, a control current is induced, causing the transistor to short-circuit the resistance, with the result that a very rapid increase in current occurs, as shown in FIG. 10 in dash line
    aa When the current passing through the solenoid reaches a steady-state value, the time derivative of the current decreases so much that the induced control current weakens to such an extent that it becomes unable to keep the transistor closed, causing the resistance to turn on again. the inductor driving the transistor is reduced, which again causes the transistor to open and the resistance to be connected to the circuit. At the same time, the current passing through the solenoid valve 50 is greatly reduced in accordance with the dash-dotted line a - a, and then remains at a constant level. Magnetic field strength generated by salt
    This is quickly reduced to a level that is barely enough to hold the core 51 in an engaged position. It is clear that the core 51
    under the action of the return spring, it very quickly returns to its original position when the power supply to the solenoid is interrupted. The big advantage of this device compared to the other two devices is that it performs the so-called control in a certain sequence in such a manner; that, before core 51 is really not retracted for the entire stroke, current limiting does not occur.
    Similar results can be obtained with the help of electrical printing circuits controlled by electronic chips.
    There are chips that allow the current to pass unhindered when the ei o is supplied for a short time - ii o. The current increases in a continuous line from O to (/
    B. After this period of time has elapsed (in this case several milliseconds), the so-called 1H breaker included in the chip converts the current into a pulsating direct current, the average voltage of which is determined by the mutual occurrence of the time between off and on. With
    In this case, the strength of the current. And falls in accordance with the thin solid line from b to c, after which it remains at a constant level.
    In some areas of application of the modulator it becomes enough to be sufficient; chip, which is a limiter T Eka. When the current to the solenoid is started, the current can flow unimpeded until it reaches a given current strength at point d, after which the current remains constant at this point. The continuation of the process is shown by the dotted line d
    P-rmula of the invention
    权利要求:
    Claims (5)
    [1]
    1. A braking force modulator, which is part of the vehicle’s anti-lock braking system, containing a hydraulic cylinder, the piston of which is connected to the brake chamber of the wheel of the brake wheel on the brake mechanism connected by pipelines
    1913
    a brake valve to a source of compressed air, a piston hydraulic pump with an electric drive for pumping oil through pipelines from the hydraulic tank into the working chamber of the hydraulic cylinder, which is connected via an modulating valve to the hydraulic pump inlet valve, and a dynamic state sensor of the braked wheel electrically connected to the windings of the electric motor and The solenoid valve is in this case the modulating valve is pneumatically controlled, its control chamber is connected to a source of compressed air by means of a solenoid valve. spirit, characterized in that, in order to increase reliability, it is equipped with a valve assembly, in the housing of which shut-off and relief valves are located, having control pistons installed in the housing chambers communicating with the pipeline connecting the working chamber of the hydraulic cylinder with the modulating valve a shut-off valve is integrated in the pipeline connecting the brake valve to the brake chamber, and the unloading valve is connected to the specified pipeline between the shut-off valve and the brake chamber.
    [2]
    2. The modulator according to claim 1, characterized in that it is provided with a normally open switch, controlled by a brake chamber rod and included in an electrical circuit connecting the dynamic wheel sensor to the coil of the solenoid valve.
    820
    [3]
    3. The modulator according to claim 1, which is so equipped with a pneumatic control shut-off valve, through which another cylinder of the hydraulic cylinder is connected to the hydraulic tank, while the control chamber of the specified valve is in communication with the brake chamber.
    [4]
    4. The modulator according to claim 3, characterized in that it is equipped with an electropneumatic pressure sensor integrated in another chamber and an electric cylinder connected to an electrical circuit between the dynamic state sensor and the solenoid valve winding, wherein the contacts are. electropneumatic sensor normally open.
    [5]
    5. The modulator according to claim 1, p. L and - due to the fact that the piston pump is made multi-cylinder with a piston drive; from the common eccentric on which the ring is mounted, while at the ends of the pistons and on the peripheral part of the ring there are spherical recesses in which balls are placed having smaller radii than those of the spherical recesses.
    6, the modulator according to claim 1, characterized in that the reservoir of the hydraulic tank is connected to a source of compressed air by means of a reduction valve supporting
    constant pressure in the hydraulic tank cavity, and a modulating valve connected to the hydraulic pump inlet valve through a check valve.
    J8
    . 2
    71 77
    76 17 11
    fug.1
    e.4
    6
    fi &. five
    21
    2
    FIG. 7
    58
    Y ////// y ////// A
    /
    Shch1 / //// l
    I E “SV |
    55
    . five
    "but
    d
    .a
    .f
    with
    sh ", - -., LH
    Vu2, W
    . /five
    Fig.I
    类似技术:
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    US5152586A|1992-10-06|Anti-locking hydraulic brake system
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    US6203117B1|2001-03-20|Compensator assembly in a hydraulic control unit for vehicular brake systems
    US3813130A|1974-05-28|Antiskid control system
    JPH10500639A|1998-01-20|Hydraulic brake device with slip control
    US5161865A|1992-11-10|Hydraulic modulator with working piston connected to control piston
    US5167441A|1992-12-01|Anti-lock brake system for automotive vehicles
    JP3643596B2|2005-04-27|Actuation system and mechanism
    SU1321368A3|1987-06-30|Braking force modulator
    US4708405A|1987-11-24|Brake pressure generator for a hydraulic brake system for use with motor vehicles
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    US4815792A|1989-03-28|Anti-blocking system
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    US4012080A|1977-03-15|Pneumatic to hydraulic converter with integral dump chamber
    US4616727A|1986-10-14|Hydraulic steering force booster
    US4681375A|1987-07-21|Hydraulic brake system for automotive vehicles
    US5286102A|1994-02-15|Brake control device
    同族专利:
    公开号 | 公开日
    US4636011A|1987-01-13|
    JPS60113756A|1985-06-20|
    FI76026B|1988-05-31|
    BR8405529A|1985-09-10|
    AU3483284A|1985-05-09|
    CA1242233A|1988-09-20|
    ES537275A0|1985-11-01|
    PT79437B|1986-08-05|
    AU573274B2|1988-06-02|
    SE8305977L|1985-05-01|
    FI76026C|1988-09-09|
    DE3477905D1|1989-06-01|
    PT79437A|1984-11-01|
    FI844146L|1985-05-01|
    SE453982B|1988-03-21|
    ES8601030A1|1985-11-01|
    FI844146A0|1984-10-22|
    SE8305977D0|1983-10-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3022114A|1958-01-31|1962-02-20|Thompson Ramo Wooldridge Inc|Brake control system|
    US3356910A|1965-02-19|1967-12-05|Whittaker Corp|Integrated power controlled solenoid|
    US3582718A|1969-04-18|1971-06-01|Cutler Hammer Inc|Circuit for improving relay performance with current limiting|
    US3729235A|1971-09-03|1973-04-24|Bendix Corp|Integrated brake booster and adaptive braking modulator|
    JPS5534011B2|1972-07-31|1980-09-04|
    DE2333125A1|1973-06-29|1975-01-23|Wabco Westinghouse Gmbh|ANTI-SKID CONTROL SYSTEM FOR PRESSURE-ACTUATED VEHICLE BRAKES|
    US4166657A|1975-02-19|1979-09-04|Blomberg Folke Ivar|Brake actuating and relieving structure|
    JPS5281602A|1975-12-27|1977-07-08|Teijin Seiki Co Ltd|Radial piston type liquid pump motor|
    DE2701866C2|1976-01-29|1986-04-30|Honda Giken Kogyo K.K., Tokio/Tokyo|Control device for an anti-lock vehicle brake system|
    US4053187A|1976-11-16|1977-10-11|Crane Co.|Single gain skid control valve and skid control system|
    FR2431943B1|1978-07-24|1982-02-26|Ferodo Sa|EP0449320B1|1990-03-30|1996-12-11|Akebono Brake Industry Co., Ltd.|Brake control unit|
    DE4107625A1|1991-03-09|1992-09-10|Teves Gmbh Alfred|HYDRAULIC UNIT|
    US5490721A|1994-11-22|1996-02-13|Eaton Tennessee, Inc.|Anti-lock brake system with motor and gear pump assembly|
    DE102016213031A1|2016-07-18|2018-01-18|Ford Global Technologies, Llc|Method for smoothly stopping a motor vehicle|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE8305977A|SE453982B|1983-10-31|1983-10-31|BRAKE POWER MODULATOR INCLUDED IN A LOAD-FREE BRAKE SYSTEM FOR VEHICLES|
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