JPS611569A - Hydraulic braking-pressure control valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The invention relates to a hydraulic brake pressure control valve, in particular for a brake booster, which brake pressure control valve is connected to a pressure supply. a control slide whose casing with a cylinder can be moved longitudinally via an actuating member such as a pedal; and an additionally electrically actuated reservoir for generating brake pressure in at least one vehicle brake cylinder independently of the pedal actuation. It relates to a type having nine controlled members.

BACKGROUND ART A vehicle brake system belonging to the prior art (Federal Republic of Italy Patent Application No. 3240680) includes a brake booster equipped with a booster chamber, and pressure is introduced into the booster chamber from a pressure supply section. and a brake pressure control valve operable via the brake pedal.

This brake pressure control valve is associated with an adjusting drive, which acts in the same way as a brake pedal on the brake slide of the brake pressure control valve. This adjusting drive is connected, for example, if it is necessary to check the sealing of the vehicle brake system or if a drive slip occurs at the drive wheels. Since this regulating drive is arranged on the brake pressure side of the brake pressure control valve, this regulating drive precludes the integration of the brake booster into the vehicle.

Advantages of the Invention The brake pressure control valve according to the invention, for example on the component side of a brake booster, has the advantage that it saves construction space and is therefore easier to install in the vehicle.

Advantageous embodiments of the brake pressure control valve according to the invention as defined in claim 1 are obtained by the measures set forth in the following claims. One embodiment is given by the means of claim 2. Other embodiments can be obtained by the means described in claim 3. The measures according to claim 4 provide an embodiment for extracting the adjustment energy for returning the control bushing to its starting position in the pressure supply.

FIRST EMBODIMENT The brake pressure control valve 2 shown in FIGS. 1 and 2 is a component of, for example, a brake booster bag 3. This brake booster 3 belongs to the vehicle brake system 4. The vehicle brake system 4 comprises a pressure supply 5, known from the prior art, to which a Bregie pressure control valve 275N is connected, a supply valve 7, two downstream check valves 8, 9, this check valve 8.
The valve block 6 has skid control valves 10.11 and 12.13 downstream of the valve block 9. The skid control valves lo to 13 correspond to the construction of a typical δ-port δ-position directional valve connected to a wheel brake cylinder (not shown). Check valve 8 as a bypass for each skip P control valve 10 to 13
．． A check valve 14,1 is provided between the brake cylinder 9 and each wheel brake cylinder.
5 and 16, 1.7 are arranged in such a way that they open in the direction of the check valve 8 or 9. It has a control m slider 19 and a control bush 20. This control slider 19 is connected to a push rod 22 and a distance spring 2.
protruding from the control bushing 20 in the direction of the distance simulator 21 having a distance of 3°C. The distance spring 23 is supported by the push rod 22 at 0/-424 degrees Celsius on the opposite side from the break.
・Ru. This plate 24 has a distance spring guide tube 25 in the direction of the brake pressure control valve 2. This distance spring guide tube is tightly connected to the plate L'-1-24 and can be inserted into the casing 18 in a sealed manner.

The control bushing 20 has a region A having a first diameter near the end 20a from which the control slider]9 projects. This range AK corresponds to the other end 20 of the control bushing 20.
In five directions towards b, a region B follows with a second diameter that is larger than the first diameter. From this area B finally a further area C extends as far as the other end 20b of the control bushing 20. This region C has a third diameter that is larger than the second diameter in region B. Therefore, the outside of this control bushing 20 is constructed in the form of a stepped piston. In region A, the control bushing 20 has two annular grooves 27 and a sealing element 28 inserted therein 7). Range B
Similarly, an annular groove 29 is provided, and this annular groove 29 similarly receives a seal ring 30.Finally, an annular groove; 31 is also arranged in area C. A sealing ring 31' is likewise received.
The cylinder 33 belongs to the range C, and the cylinder 34- belongs to the range C. A shoulder portion 35 is provided between the cylinders 32 and 33.
A conical transition 36 is provided between the cylinders 33 and 34. The cylinder 34 closes the end wall 3
7 has an annular groove 38 spaced from the end wall. A wire ring 39 is inserted into this annular groove. This wire ring 39 is the second
It forms an axial stop for the end 20b of.

Between the end wall 37 and the wire ring 39 the cylinder 34 has a connection 40 . This connecting portion 40 is connected to a control valve 41 configured as a three-boat two-position directional switching valve. This control valve 41 is likewise connected to the pressure supply 5 and is further connected to a storage tank 42 . The control valve 41 is electromagnetically controllable and connects the connection portion 40 to the storage tank 42 in its non-energized basic position.
so that the cylinder 3 in the area of the end wall 37
4 is no pressure. The cylinder 32 has a connection 43 connected to a storage tank 42 . As a result, no pressure is applied to the control bushing 20 in the projecting end region of the control slide 19. In the direction towards the dowel connection 43 , the control section 20 has at least one radially oriented vacuum hole 44 . Cylinder 3 in contact with shoulder 35
3 has a connecting part 45. The connection 45 is directly connected to the pressure supply 5 . An outer circumferential groove 46 is formed in the control bushing 20 opposite the connecting portion 45 I7. At least one radially oriented blind hole 47 extends from this circumferential groove 46 . The circumferential groove 46 has side surfaces 4-6a at its maximum diameter. Furthermore, the cylinder 34
has a connecting portion 48 in contact with the transition portion 36 . This connection 48 connects the cylinder 34 to the brake booster cylinder 4.9 of the brake booster 30. Opposed to this connecting portion 48, the control bushing 20 has an outer peripheral groove 50. A radially oriented throttle hole 51 opening into the central hole 52 of the control bushing 20 is connected to this circumferential groove 50 .

This central bore 52 extends in the direction of the end 20b and is closed there at the end face 26 by a closing screw 53 and a sealing plate 54. A slider receiving hole 55 is connected to an extension of the central hole 52 . The pressure reduction hole 44 and the control hole 47 open into this slider receiving hole 55. A booster pressure passage 56 opens into the slider receiving hole 55 between the pressure reduction hole 44 and the control hole 47 .

This booster pressure passage 56 is connected to the outer circumferential groove 50 via a vertical hole 57 and a horizontal hole 58. Therefore, the slider receiving hole 55, the center hole 52, and the connecting portion 48 are connected to each other. The projecting end of the control slide 19 forms a first control piston 59 which is connected via an intermediate small diameter section 60 to a second control piston 61 . A first control piston 59 is assigned to the pressure reduction hole 44 , and a second control piston 61 is defined for opening and closing the control hole 47 . The intermediate small diameter section 60 has a smaller diameter than both control pistons.

The plate 24 is movable via the pedal push rod 62 in the direction of the distance spring guide tube 25 . This pedal push rod is pivotally connected to the pedal lever 63. This pedal lever 63 has a pedal 64. Parallel to the distance spring guide tube 25 and at least approximately in the extension of the pedal push rod 62 is the booster cylinder 49 already mentioned.
is located. Starting from the plate 24, an emergency brake push rod 65 projects into the booster cylinder 49 in a manner known per se. This emergency brake push rod 65
A booster piston 66 is movably arranged in the booster cylinder 49 in the extension. This booster piston 66 is connected via a conical neck 67 to a first master brake piston 66 . The diameters of both pistons have, for example, the same diameter, so that the booster cylinder 49 serves as master brake cylinder in the area of this master brake piston 68. A cylinder 69 is additionally arranged in the extension of this booster cylinder 49 . This cylinder 69 movably receives a second master brake piston 70 and also serves as master brake cylinder. This cylinder 69 has a smaller diameter than the booster cylinder 49, for example. The cylinder 69 belongs to the first brake circuit (2) and is connected to the valve block 6 and to the skid control valves 10 and 11 in this valve block. A second brake circuit (2) to which the skid control valves 12 and 13 belong is connected between the master brake piston 68 and the master brake piston 70. For example, each brake circuit I, H has its own axle. However, a so-called diagonally divided brake circuit may also be selected in a manner known per se.

This vehicle braking device 4 functions in the following manner: A pressure supply 5 is connected to start the operation.

The pressure generated by this pressure supply 5 is transmitted to the brake pressure control valve 2 and reaches the outer circumferential groove 46 and the control hole 47 through the connection 45 . Because the diameter of the control bushing 20 differs in the area of the shoulder 35, the control bushing 20 forms a differential piston. Therefore, since the pressing force applied to the side surface 468 of the outer circumferential groove 46 is predominant, the control bushing 20 is moved towards the wire ring 39.

With pedal 64 released, control slide 19 is in the position shown. At this time, the control piston 61 closes off the control hole 47 connected to the connection member 5, and the control piston 59 opens the pressure reduction hole 44.

To initiate braking, the pedal 64 is moved from its rest position, so that the pedal lever 63 is connected via the pedal push rod 62 to the plate 24, the distance spring 23 and the push rod 2.
2. Move the control slider 19 in the direction of the end 20b of the control bushing 20. At this time, the control piston 59
4 is closed, and the control piston 61 opens the control hole 47. When the control hole 47 is opened, the portion of the slider receiving hole 55 located between the control piston 59 and the control piston 61 passes through the booster pressure passage 56, the vertical hole 57, the horizontal hole 58 and the connecting part 48, and doubles. It receives pressure transmitted to the force device cylinder 49.

At the same time, this pressure is also transmitted through the throttle hole 51 to the central hole 52, where it loads the end face side of the control piston 61. The control slide 19 transfers this load to the push rod 22, which elastically compresses the distance spring 23. −
``!!Depending on the amount of depression of the barrel 64, the load on the control piston 61 is low, or when a higher pressure is applied, the control slider is moved until this control piston 61 closes the control hole 47. A balance is obtained between the load force on the time control piston 61 and the control force transmitted to the distance spring 23 via the pedal 64. When the pedal 64 is released, the distance spring 23 is at least partially relieved.

The pressure thus created in the booster cylinder 49 and the central hole 52 causes the control slider 19 to cause the control piston 59 to open the vacuum hole 44, so that the storage tank 4-2
By outflow of the pressure medium through the connection 43 in the direction , the pressure in the booster cylinder 49 can be reduced, for example back to the position shown.

The pressure in the booster cylinder 49 acts on the booster piston 66 in a manner known per se.

This booster piston moves the master brake piston 68 via the neck 67, thereby generating brake pressure in the brake circuit ■, and simultaneously moves the master brake piston 7o, so that pressure is also generated in the brake circuit ■. brought about. However, it is also possible to design the vehicle brake system in such a way that the brake circuit (2) forms a so-called open-circuit brake circuit. The brake pressure in both circuits is transferred to the skid control valve 10, whose basic position is the flow position. , 11.12.13 to the wheel brake cylinders (not shown). By returning the pedal 64 in the manner described above, the pressure in the booster cylinder 49 is reduced and the pressure in the brake circuits 1 and U is reduced. If overbraking occurs on one of the wheels, the associated skid control valve 10-13
is controlled to its reduced pressure position, so that the pressure at the wheel brake in question is reduced. However, the pressure remains maintained before the skid control valves 10-13. When the now slightly more braked wheel is sufficiently accelerated, the corresponding skid control valve is returned to its basic position and the amount of pressure medium that was previously discharged is replenished.

This takes place via at least one of the two check valves 8, 9 and the supply valve 7. This supply valve 7 is controlled from the basic position shown into the supply position and thereby connects the booster cylinder 49 to the check valves 8,9. Corresponding to this regulation, which is known for skid control systems, check valves 14, 15, 16, 17 are used to control the rate of change of the brake pressure. The liquid control valves 10-13 also have a pressure maintenance position, as shown for the example liquid control valve 13. By using this pressure-maintaining position, the brake pressure acting on the wheel brakes can be adapted in an advantageous manner to the respective requirements.

For example, in the event of an inconvenient drive slip, or in the brake circuit■
If a pressure increase in at least one of the wheel brakes is required without actuating the pedal 64 in order to check the sealing properties at is controlled to the flow position where it connects to the connection part 40. This allows control bushing 2
The end 20b of 0 is loaded by the pressure of the pressure supply 5. This pressure creates a moving force directed toward end 20b. This moving force is larger than most of the pressing forces described above, and moves the control bushing 20 away from the wire ring 39 until the side surface 46a abuts the shoulder 35.

The shoulder 35 limits the movement of the control bushing 20.

This movement of the control bushing 20 first causes a movement of the vacuum hole 44 and then opens the control hole 47. Connecting parts 45 and 4
Due to the pressure gradient between 8 and 8, pressure medium flows into the booster pressure channel 56 and from there subsequently into the booster cylinder 4-9 in the manner described above. Booster cylinder 49
When pressure is no longer required in the connection 4, the control valve 41 cuts off the inflow of pressure medium from the pressure supply 5 and closes the connection 4.
0 is returned to its rest position connecting the storage tank 42. This causes a reduced pressure at the end 2ob, so
Due to the differential load described above in the area of the circumferential groove 46, the control bushing 20 is returned to its starting position as shown.
Second Embodiment The second embodiment shown in FIG. 3 differs from the embodiment shown in FIG. 1 in that an electromagnet 71 serves to displace the control bushing 20. . This electromagnet 71
are the coil 72, yoke 73, mover 74 and push rod 75
have. This push rod 75 is connected longitudinally to the armature 74 and is arranged coaxially with respect to the control bushing 20 . In the direction of the longitudinal axis of the control bushing 20, the wall 37 has a bore 76. Through this hole 76 a push rod 75 extends towards the closing screw 53. The sole ring 77 serves to ensure that no pressure medium is lost between the hole "/6 and the push rod 75. In contrast to the embodiment according to FIG. 1, the connection 40 is connected directly to the storage tank 42. This electromagnet 71 is connected when booster pressure is required to operate the barrel 64. The movement of this electromagnet: F74 is connected to the control bush 2 via the pusher 1 to the rod 75, the closing screw 53 and the sealing plate 54.
0 until side 468 contacts shoulder 35. This damping of the control bushing 20 causes a pressure increase in the booster cylinder +9 in the same manner as already described with respect to the first embodiment. When the increased pressure is no longer required, the electromagnet 71 is shut off. The pressure supplied through the connection 45 of the pressure supply 5 thereby causes the control bushing 20 to be moved towards the electromagnet 71 until it rests against the wire ring 39 in its starting position shown. The end 20b of the control vent 20 then sends the pressure medium through the front connection 40 of this end to the pressureless storage tank 42. This connection 40 is connected to the control bush 2o at the same time.
It also forms a drain for any pressure medium that may leak between the cylinder 33, 34 and the cylinder 33,34.

Supplementally, the idea of the present invention, that is, arranging a movable control part as a control bush between the casing of the control valve and the control slider within the brake pressure control valve, is limited to the illustrated booster structure. Not done. Thus, for example, a brake pressure control valve of the type according to the invention can also be arranged coaxially with respect to the booster cylinder or the master brake cylinder. A brake pressure control valve with a coaxial arrangement of this kind, which can be constructed in accordance with the invention, is described, for example, in DE-A-32 44 560.

Advantages of the Invention The brake pressure control valve according to the present invention constructed in this way can be more easily installed in a vehicle due to the saving of construction space.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a brake pressure control valve according to the present invention together with a vehicle brake system, FIG. 2 is a detailed longitudinal cross-sectional view of this brake pressure control valve with different dimensions, and FIG. 3 is a diagram showing a second brake pressure control valve according to the present invention. FIG. 3 is a diagram showing a brake pressure control valve according to an embodiment. 2... Brake pressure control valve, δ... Brake booster, 4... Vehicle brake device, 5... Pressure supply unit. 6... Valve block, 7, 8... Supply valve, 10, 1.
].

Claims (6)

[Claims] 1. A hydraulic brake pressure control valve, in particular for a brake booster, which brake pressure control valve is connected to a pressure supply and whose housing with a cylinder is actuated via an actuating member such as a pedal. of the type having a longitudinally movable control slide and an additional electrically controlled element for generating brake pressure in at least one vehicle brake cylinder independently of pedal actuation. A control bush (20) that is movable relative to these members is incorporated between the casing (18) and the control slider (19), and electrically controllable members (41, 71) Hydraulic brake pressure control valve, in particular for a brake booster, characterized in that ) produces a movement of a control bush (20) relative to a control slide (19). 2. Said control bushing (20) is closed at one end (20b) and forms an adjusting piston surrounded by a cylinder (34), which is closed at one end (20b) and is surrounded by a cylinder (34). an end wall (37) adjacent to the end (20b), and an end wall (37) and the end (20b);
0b), and this connection (40) is connected to the pressure supply part (5) via the control valve (41).
A brake pressure control valve according to claim 1, which is connected to a storage tank (42) and a storage tank (42). 3. The electrically controllable member is a control bushing (20).
2. The brake pressure control valve according to claim 1, wherein the brake pressure control valve is constructed as an electromagnet (71) for displacing the brake pressure. 4. said control bush (20) is configured as a stepped piston and is provided with a cylinder (32, 33) having a diameter adapted to the diameter of the control bush (20);
The cylinder (33) has a connection (45) connected to the pressure supply (5) in the transition region from a relatively large diameter section to a relatively small diameter section and the control bush (2).
Brake pressure control valve according to claim 2 or 3, wherein the relatively large diameter portion of 0) is located closer to its end (20b) than the relatively small diameter portion. . 5. said cylinder (32) having a relatively small diameter;
is stepped from the cylinder (33) having a relatively large diameter by a shoulder (35), which shoulder (35)
5. Brake pressure control valve according to claim 4, wherein the brake pressure control valve 5) forms an axial stop for the control bushing (20) in the direction of the pedal (64). 6. Brake pressure control valve according to claim 2 or 3, characterized in that an axial stop (39) for the end (20b) of the control bushing (20) is arranged in the cylinder (34). 7. The axial stopper (39) is made of a wire ring, and this wire ring is connected to the cylinder (34).
7. The brake pressure control valve according to claim 6, wherein the brake pressure control valve is inserted into an annular groove (38) formed in the brake pressure control valve.