JPH0295957A - Car brake gear with skid controller - Google Patents

Abstract

PURPOSE: To enable the combination with a low-cost valve gear controlled by pressure medium by controlling brake pressure of a second split brake to be the lower brake pressure of a first split brake each time. CONSTITUTION: When a valve gear 15 is controlled to lower brake pressure of a partial brake 6, pressure medium goes through a first shut-off valve 34 to escape from a control chamber 51 to a pressure accumulator 19, and then an over-pressure to move a first control piston 37 with a second control piston 39 against force of a return spring 42 is formed. The control piston 39 is moved, a valve ball 54 is applied to a valve seat 60, and the shut-off valve 35 is moved to a shut-off position. The flow of pressure medium from a brake circuit II into the control chamber 52 is thus eliminated. As a result, when the control pistons 37 and 39 are moved continuously, a volume of the control chamber 52 is enlarged, and pressure fall is generated in a second split brake 7 on the left side connected.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention is a vehicle braking system having a skid control system, which includes a two-circuit brake pressure source, two conventional brakes on one axle, and a separate brake system. a skid having first and second partial brakes which are arranged on the axle of the vehicle and which can be supplied with brake pressure from both brake circuits and at least six electrically controllable valve arrangements for regulating the brake pressure. and a control device, in which one of the valve devices is assigned to the first partial brake on each vehicle side.

In the vehicle braking system known from prior art US Pat. No. 4,460,963, the second partial brake exhibits a special control logic circuit in an undesirably complex manner to control both valve systems of the first partial brake. They are connected to a common valve system which must be electrically controlled in relation to the operating state.

Bosch Technical Report Volume 7 No. 2 Pages 87 to 89
A skid control device with a valve device of the type described on the page is already inexpensively mass-produced for a real-life brake system with four conventional car brakes. In this case, the cough pressure control device has six or four valve arrangements, depending on the configuration of the two brake circuits of the vehicle brake system. The realization of the vehicle braking system disclosed in US Pat. No. 4,460,963 with an additional skid control device for the wheels of the second axle is achieved by means of a mass-producible skid control device of the aforementioned type with four valve devices. It would be possible. In this case, the rake pressure on both brakes of the second axle can only be adjusted to select low 5fLra. This has the disadvantage that braking distances become longer if the wheels to be braked are subject to significantly different loads, which cannot be avoided depending on the vehicle type. This disadvantage occurs particularly when the vehicle has a short axle distance and a high center of gravity and the loading capacity of the luggage compartment is relatively large. Moreover, since such an electrically controllable valve arrangement and its electrical sterilization logic circuit are relatively expensive, any additional iE electrical valve arrangement cannot achieve advantageously short braking distances. Even if it does, it makes the vehicle brake system expensive.

Effects of the Invention The advantage of a brake system for a vehicle with the features set out in claim 1 is that, when a split brake is arranged on one axle, a large number of The advantage is that the inexpensive skid control devices that can be produced can be used in combination with the inexpensive valve devices that are already mass-produced and can be controlled by pressure medium, as disclosed, for example, in DE-O 83631128.

This results in low costs for an airtight controllable valve system and eliminates the need for new manufacturing equipment to manufacture the components of the vehicle brake system of the present invention. Furthermore, testing of skid control devices with additionally controllable valve devices is not necessary in this case.

Although the embodiment according to claim 2 uses an existing skid control device having four valve devices that are electrically K iff controllable, the brake pressure of the wheel brakes of the second axle shortens the braking distance. It has the advantage that they can be adjusted independently of each other according to the independence principle in order to Therefore, the coefficient of friction between the wheel to be braked and the road surface is independent of whether different friction conditions exist on the right and left sides or whether the vehicle is traveling around a curve. It will be fully utilized regardless of whether the vehicle is empty or fully loaded. Furthermore, the features recited in claim 3 provide the advantage that the two feedback pumps can be constructed relatively inexpensively.

Next, the present invention will be explained with reference to the drawings: A vehicle brake system 2, which is a first embodiment of the present invention shown in FIG. 1, is a two-circuit brake pressure source that supplies brake pressure to brake circuits a first partial brake on the left side of the axle 10 of the red 1, a second partial brake on the left side, a first partial brake on the right side 8 and a second partial brake on the right side 9. and a conventional left brake 11 and a conventional right brake 12 on the second axle 13. Brakes 7.8, 11.12 belong to brake circuit (2), and brakes 6 and 9 belong to brake circuit (2). Such a brake relationship is generally called an HT brake circuit.

The two-circuit brake pressure generator 4 is configured as a tandem mask cylinder to which a brake booster 14 of Nikyu Machida type is attached, for example.

The skid control device 5 is located between the brake pressure generator 4 and the brakes 6.7, 8, 9, 11.12. Skid control device is electrically controllable 4
1 valve device 15° 16, 17, 18 and 2 pressure accumulators 19
．． 20 and two feedback pumps 22 and 23 driven by the motor 21, a control device 24, and the control device 2.
Wheel rotation sensor connected to 4 25° 26.27.28
and a valve device 29 that can be controlled by the pressure medium pressure.

The valve arrangements 15, 16, 17, 18 are preferably designed as 6-point, 6-position valves as shown, but they can also be replaced by a combination of two 2-point, 2-position valves. In the basic position, the valve arrangement 15 connects the brake circuit (2) with the first partial brake 6 on the left. Valve device 16
connects the brake circuit "" with the first partial brake 8 on the right. In the basic position, the valve arrangement 17 connects the left-hand brake 11 with the brake circuit "■", and the valve arrangement 18 likewise connects the right-hand brake 12 with the brake circuit ". Connected to circuit ■.

The valve arrangement 15.degree. 16.17.18 can be switched to a neutral position in which all six valve connections are mutually isolated.

In the sixth position, the valve arrangement blocks the brake 6.8.1112 from the brake pressure source 4. However, valve device 1
Relief of the pressure on the brake 6.8.1112 with 5.16.17.18 in the blocking position is achieved by the safety bypass valve 30.
, 31°32.33. The safety bypass valves 30, 31, 32, 33 are configured in the form of one-way valves and can be opened towards the brake pressure source 4.

In the sixth position, the valve arrangement 15 connects the first partial brake 6 to the pressure accumulator 19 and the feedback pump 22 . On the outlet side, the feedback pump 22 is connected to the brake circuit I. Pressure accumulator 19 and feedback pump 22
Since this belongs to the known technology, we judge that there is no need to explain it. In the same manner, the valve arrangement 16 connects the right-hand first partial brake 8 with the pressure accumulator 20 and the feedback pump 23 during skid control. The feedback pump 23 is connected to the brake circuit (2) on the outlet side.

The valve arrangements 17 and 18 have the same construction, and in the sixth position the left-hand brake 11 and the right-hand brake 12 are activated by the pressure accumulator 20 and the associated feedback pump 23 in the brake circuit (2).
Connect with.

A wheel rotation sensor 25 is assigned to the valve arrangement 15 and emits an impulse when the associated wheel rotates. These impulses are processed by a control device in order to sense the danger of the wheels locking up. There is a risk of the wheels locking up.
By means of the valve device 15, the brake pressure of the partial brake 6 is regulated in a manner known per se. The valve arrangement 16, 17.18 can be correspondingly controlled using wheel rotation sensors 26, 27.28 and the control device 24. Therefore brakes 11 and 1
The braking force of 2 is directly controlled using valve devices 17,18. In contrast to this, the valve arrangement 15.16 directly transfers the braking force of the partial brake 6.8 on the one hand and additionally to the second partial brake via a valve arrangement 29 which can be controlled by pressure medium. Controls 7 and 9.

The valve device 29 includes a first cutoff valve 34, a second cutoff valve 35,
A control cylinder 38 with a first control piston 37, a coaxially arranged second control cylinder 38 with a second control piston 39, a sealed guided rod 40 between the control pistons 37 and 39. 2 return springs 41.4
2 and spring receivers 43 and 44. Spring receiver 43
．． 44 is a control stone 37, 38 facing the rod 40;
is disposed in hole 45,46 adjacent to. Hole 45
．． 46 has a larger diameter than the control cylinders 36 or 38, which have the same diameter. Return spring 4
3 and 44 are assembled with bias, and the spring receivers 43.
44 is loaded. The transition between bore 45 and control cylinder 36 forms a ring shoulder 47 . A further ring shoulder 48 is formed in the same manner between the control cylinder 38 and the bore 36. The ring shoulders 4T and 48 form stops for the spring receivers 43, 44. Therefore, the force of the return springs 41, 42 is due to the force exerted by the spring supports 43° 44 on the ring shoulder 43.
．． It only works while it is not in contact with 44. The return springs 41, 42 together with the spring receivers 43 and 44 are connected to the control pistons 3γ and 3.
A return device is formed for adjusting each of 9 to the reference position shown.

The hole 45 forms a peripheral wall of a pressure chamber 49 connected to the brake circuit (2). Similarly, the hole 46 forms the peripheral wall of another pressure chamber 50 connected to the brake circuit (2). Adjacent to the control piston 3γ, the control cylinder 36 forms the peripheral wall of a control chamber 51, which is connected to the partial brake 6 via a shut-off valve 34. Correspondingly, the control cylinder 38
There is another control chamber 52 inside, and this control chamber 52 has a shutoff valve 3.
5 can be connected to a first partial brake 8 . The shutoff valve 34.35 has a valve ball 53.54 and a closing spring 55,56.
have. Furthermore, each control piston 31 and each valve ball 53
Opening rods 5γ, 58 are provided between the control piston 39 and the valve ball 54.

The lengths of the control pistons 37 and 39 and the length of the rod 40 are matched in such a way that the control pistons 37, 39 and the rod 40 are arranged without play between the spring supports 43, 44 in contact with the ring shoulders 4γ, 48. I'm forced to. The length of the opening rods 57, 58 is selected such that the valve ball 53, 54 is lifted from the valve seat 59, 60 when the pistons 37, 39 are in the reference position. When the control pistons 37 and 39 are in the reference position, the control chamber 51 or 52 is therefore loaded with the pressure that is present in the partial brake 6 or in the partial brake 8.

Furthermore, the control chamber 51 is permanently connected to the second partial brake 9 on the right side of the vehicle. Correspondingly, the other control room 5
2 is permanently connected to the second partial brake 7 on the left side of the vehicle. When the control pistons 37 and 39 are in their reference position, therefore, the same pressure level occurs in the left-hand first partial brake 6 and the right-hand second partial brake 9. In this case, pressures of the same magnitude occur in the first partial brake 8 on the right and in the second partial brake T on the left. In the case of normal braking operation, that is, when there is no need to eliminate the risk of wheel locking, the assigned left wheel and the assigned right wheel are connected to each other when the vehicle brake system 2 is normal and the brake circuit I If substantially equal pressure is created between and ■, braking will be done with the same strength.

When a condition occurs in which the brake pressure of the nine-part brake 6 decreases by controlling the valve device 15, the first cutoff valve 3
4, the pressure medium escapes from the control chamber 51 to the pressure accumulator 19. As a result, the first control piston 3T is returned to the second control piston 3T against the force of the spring 42 in the pressure chamber 49, since the pressure of the brake circuit (2) continues to be effective there.
An overpressure is created which causes the control piston 39 to move together with the control piston 39 . As a result of the movement of the second control piston 39, the closing spring 56 moves the valve ball 54 and the opening rod 58 into the second pressure chamber 5.
Move in the direction of 0. In this case, the final valve ball 54
contacts the valve seat 60, and the shutoff valve 35 is brought to the shutoff position. Therefore, no pressure medium flows into the control chamber 52 from the brake circuit (2).

As a result, if the control pistons 37 and 39 are subsequently moved, the volume of the control chamber 52 is enlarged, which causes a pressure drop in the connected left-hand second partial brake 7 .

The described valve arrangement 15 thus results in, in addition to a brake pressure drop in the left-hand segment brake 6.7, a brake pressure drop in the opposite segment brake 8. This results in the advantage that, in addition to eliminating the risk of the left-hand wheel locking up, the braking force difference between the left-hand wheel and the right-hand wheel is limited, making it easier to control the vehicle. When skid control is activated on the left side, the course change force generated by the difference in braking force on the left and right sides strongly prevents the vehicle from running uncontrollably to the right.

Due to the symmetrical design of the valve arrangement 29, the second
If the brake pressure is lowered via the valve device 16 of the brake circuit (2), the brake pressure in the left-hand second partial brake 7 facing the right-hand first partial brake 9 of the vehicle is also reduced. . Furthermore, the valve device 29
At the connection assigned to the second partial brake γ or 9, a brake pressure of substantially the same magnitude acts, which corresponds to the lower brake pressure in the first partial brake 6 or 8, respectively.

For example, if the brake circuit I is missing and brake pressure is generated by the brake circuit ■, there is no pressure in the pressure chamber 49, and the city control piston 39 is loaded with the pressure of the brake circuit ■. Based on this, the control piston 39 is loaded in the direction of opening the isolation valve 35. The same thing applies when a leak occurs in the brake circuit (2) and brake pressure is to be obtained only from the brake circuit (I).

Of course, the valve arrangement 29 can also be replaced by other valves in which the shutoff valve and the control piston have a different relationship to each other than in the case of the valve arrangement 29. An example of such a valve is disclosed in DE-OS 3631128 mentioned at the outset.

As already mentioned at the beginning, a highly-produced product can be used as the valve device 29, and the valve devices 15, 16, 17°18 can also be mass-produced in combination with the pressure accumulator 19.20 and the feedback pump 22.23. It is now possible to provide a skid control device for a vehicle brake system with a brake divided into two child shafts in a cost-effective manner.

If the adjustment of the brake pressures of the left brake 11 and the right brake 12 independent of each other as explained in the embodiment is abandoned, for example, the brake pressure of both brakes 11 and 12 can be adjusted using only the valve device 17. can be adjusted together. In this case, a mass-produced skid control device having only three electromagnetically controllable valve devices can be used. Even with this concept, the skid control device can also be constructed from two component groups that can be mass-produced.

A second vehicle brake system 2a according to the present invention shown in FIG. , a left-hand first partial brake 6 and a left-hand second partial brake on the first axle 10 , a right-hand first partial brake 8 and a right-hand second partial brake 9 , and on the second axle 13 It has a normal brake 11 on the left side and a normal brake 12 on the right side. Brake 6.9.11 belongs to brake circuit I, and brake 7.8°12 belongs to brake circuit ■. This is called a so-called LL-brake circuit.

Based on this LI, - brake circuit, if the same friction value occurs on the left and right wheels, the feedback pumps 22 and 2
3 conveys substantially the same amount of pressure medium in the skid control operation of the skid control device 5. Feedback pumps 22 and 23 can therefore be of the same size but smaller than the embodiment of FIG. In the embodiment of FIG. 1, different numbers of brakes can be assigned to the feedback pump 22, 23 based on the HT brake circuit.

Since the vehicle brake device 2a functions in the same manner as the vehicle brake device 2 in skid control operation, a detailed explanation thereof will be omitted.

[Brief explanation of the drawing]

The drawings show two embodiments of the invention, the first
1 is a diagram showing a vehicle brake system of the present invention having an HT brake circuit, and FIG. 2 is a diagram showing a vehicle brake system having an LL brake circuit. 2...Vehicle brake device, 3...Pedal, 4...
Brake pressure generator, 5... Skid control device, 6... Partial brake, 7... Partial brake, 8.
...Partial brake, 9...Partial brake, 10...
Axle, 11... Ordinary brake, 12... Ordinary brake, 13... Axle, 14... Brake booster, 15, 16° 17.18... Valve device, 19.20
... Pressure accumulator, 21 ... Motor, 22.23 ... Feedback pump, 24 ... Control device, 25, 26
, 27° 28... Wheel rotation sensor, 29... Valve device, 3o. 31.32.33...Safety bypass valve, 34...Shutoff valve, 35...Shutoff valve, 36...Control cylinder, 3
7... Control piston, 38... Control cylinder, 39
...control stone, 40...rod, 41.42...
Return spring, 43.44...Spring receiver, 45', 4
6... Hole, 4γ... Ring shoulder, 48... Ring shoulder, 49... Pressure chamber, 50... Pressure chamber, 51... Control room, 52... Control room, 53. 54...benkyu, 55
, 56... Closing spring, 57.58... Opening bar, 5
9.60... Valve seat.

Claims (1)

[Claims] 1. A vehicle braking system having a skid control device, which includes a two-circuit brake pressure source, two conventional brakes on one axle, and two brakes disposed on another axle. The first circuit that can supply brake pressure from the circuit
and a second partial brake, and a skid control device having at least three electrically controllable valve devices for regulating the brake pressure, each of the first portion on one vehicle side. In those types in which the brake is assigned one of the valve devices, the brake pressure source (4)
and the second partial brake (7, 9) is connected with a valve arrangement (29) which can be controlled by pressure medium;
29) is connected to the first partial brake (6, 8) via two integrated shut-off valves (34, 35) and transfers the brake pressure of the second partial brake (7, 9) to the first partial brake (7, 9). Vehicle braking system with a skid control device, characterized in that it is designed to work according to the select low principle for adjusting the respective lower brake pressure of the partial brakes (6, 8). 2. One valve device (11, 12) for each ordinary brake (11, 12)
17, 18) are assigned, and the valve device (17, 18)
2. The vehicle braking system as claimed in claim 1, wherein the brake system (1) is controllable solely in relation to the rotational characteristics of the associated wheel. 3. The valve device (17) of one ordinary brake (11) is connected to one brake circuit (I), and the valve device (18) of the other ordinary brake (12) is connected to the other brake circuit (II). The vehicle braking device according to claim 2, wherein the vehicle braking device is connected to.