DE1430568A1 - Arrangement on servo brakes - Google Patents

Description

Arrangement on servo brakes,

The invention relates to a Brenismechaniprnus for Servo brakes, which is an arrangement for enlarging the Wefes a Bremapedales contains.

The 3ren; pedal travel is significantly less due to the braking become. In some cases, one is sufficient. dera.rtig shorter Brerris pedal travel not, and a sufficiently high force; with your foot to be exercised if errors in the servo braking have occurred. It is therefore the aim of the invention to provide a foot pedal, Un to control the servo brake by moving the brake pedal is at least increased to the distance of normal brakes, if errors occur in the servo braking, so that the required Lever for foot actuation is reached when the auxiliary power fails.

The aim of the invention is also the use of a servo brake

BATH ORIGINAL

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Patent attorney Dipl.-Ing. Hans Gründlch - Regensburg, Lessingstrasse 10 _

Sheet 2 _to write in front 1 5. 1 0. 63 / W to: ** 1430568

Pressure medium to reduce the brake pedal travel, so that when the pressure medium supply is lower, the pedal travel is enlarged. A brake actuation mechanism is also to be proposed in which a small pedal travel for actuation a servo brake system is provided, and in which the Pedal automatically moves to a higher position if the auxiliary power fails or other errors in the servo system occur if the brakes are being applied.

Exemplary embodiments of the invention are illustrated using the drawings described.

Fig. 1 is a schematic representation of a hydraulic Servo braking system with the arrangement according to the invention,

2 is a sectional side view of an arrangement for lifting the brake pedal in a servo brake;

Fig. 3 is a side view of another embodiment a servo braking device according to the invention in section and

FIG. 4 is an end view taken along lines 4-4 of FIG. 3.

In Fig. 1 is an embodiment of the brake pedal lifting device 10, which is incorporated into a hydraulic servo system with a pump "12" driven by a roller, an accumulator H

BATH

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Patent attorney Dlpl.-Ing. Hani Gründlch - Regensburg, Lessingstrasse 10

3 x _Ums *, eb _e "vo," i5.io.63 / vf _to: 3 1430568

and a brake operating device 16 is installed. The system has a wheel brake device 18 with a wheel cylinder 20. Also shown is a buzzer 22 which is connected to ground via a pressure fault switch 24 and connected to a power source via an ignition switch. If the ignition switch is closed, the buzzer gives an audible signal, which indicates that the pressure is too low. In order to prevent drainage in the lines required for the above-mentioned components, the accumulator maintains sufficient pressure to open the earth connection, which prevents the buzzer from being actuated have decreased the accumulator pressure as outlined below.

The pedal lifting device 10 according to Pig. 1 may simply have a piston 26 mounted to slide back and forth in a cylinder; this piston is biased against the right or front side of the cylinder by a high-performance pedersystem 28. A piston rod 30 connects the piston to a centrally pivoted lever 32, and this lever is pivotally connected at 36 with a ^Bremsbet: tip; unrsstange connected 34 in the ITähe of the central fulcrum and with the piston rod 30 at 38.. A "brake pedal lever 40 is with the lever 32 at the pivot point> 6 and in a pivot point 42, which is at a distance above the pivot point 36,

³ "BATH ORIGINAL

809311-0225

Patent attorney Dlpl.-Ing. Hans Gründich - Regensburg, Lessingstrasse 10

4 to the letter of 1 5. 1 O. 63 / W on; 1430568

tied together. As long as there is an accumulator pressure in the pedal lifting device 10 is introduced via a line 44, compressing the spring 28, the lever 32 pulls the brake pedal lever against a shielding wall 46, so that the travel of the brake pedal is short. This position is fully extended shown in fig. However, when the accumulator pressure becomes too low, the spring 26 forces the piston rod 30 to one Movement of the lever 32 around its central pivot point in the position shown in phantom in Fig. 1, wherein the Pedal travel is increased significantly.

In Fig. 2, another detailed embodiment of a pedal lifting device according to the invention is shown. In this Fig. 2 there is a housing 48 having a piston chamber 50, a valve chamber 52 and a plurality of "inner" flow paths " 54, 56, 58, 60, 62, 64 and 66 are shown. In addition, the housing has a battery opening 68 and a container opening 70 and valve openings 72, 74 and 76. These latter openings are closed and closed by plugs 78, 80 and 82 sealed, these plugs an assembly of shut-off valves 84 and 86 for controlling the flow between the flow paths 62 and 54 and 60 and enable. The shut-off valve 84 is pressed against a seat 88 with the aid of a strong spring. 90 pressed; in contrast to this A light spring 92 presses the valve 66 against the seat 94.

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Patent attorney DIpl.-Ing. Hans Gründich - Regensburg, Lessingstrasse 10

5 rum letter from 15-10. 63 / W to: 1430568

A coil 96 is arranged in the valve chamber 52 and has a central bore for receiving a plunger 98. The spool is slotted at 100 so that a pin 102 can reciprocate. The pin 102 connects the plunger 98 with a ring 104 ·. A spring 106 is between ring 104 and a radially extending plan of the Coil 96 inserted. The plunger 98 thus responds to pressure. The plunger has a head 180 that is provided with a valve seat 110 cooperates; this valve seat 110 is formed on the spool 96 and forms a temporary seal the flow path through valve seat 110 when the plunger is pressed against the seat. Opposite to At the end forming the valve head, the valve cone has a rod-like projection 112.

The valve chamber is closed by the plug 82, the at 114 has a bore in which a plunger 116 slides is appropriate. A spring 118 is used as a drive in such a way that that the plunger is pushed out of the bore 114. In addition, a ball valve 120 is attached, which is from a Plunger 116 is carried which rests against a valve seat of an end member 124 of the plug assembly, this End component rests against the spool 96 in the valve chamber 52. 2, the plug 82 has radial flow paths 126 which are in communication with flow paths 56 and 58 in housing 48.

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Patent attorney DIpI.-Ing. Hans Gründlch - Regensburg, Lessingstrasse 10

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At the other end of the valve chamber 52, a spring 128 presses against a ball 130 _{1 in} order to close the valve seat 110 completely.

For the piston chamber 50, a piston 132 is provided which is slidably mounted therein, and which in the position shown in Fig. 2 is in its rearmost position, where it is at a stop ring 134 rests, which is fastened to the housing 48 by a locking ring 136. A spring 138 holds the piston in its rearmost position when the pressure is completely removed from there, as will be explained below. A piston rod HO is drivingly connected to the piston 132; it can be connected to a brake pedal lever or a lever system for example, as shown in Fig. 1 to raise or lower the brake pedal.

The function of the brake pedal lifting device is as follows:

When the pressure builds up in the accumulator and the pedal is raised to the position in which no braking force is applied is, the pressure of the pressure medium is planted from the accumulator via the opening 68 and through the valve chamber to the Flow paths 62 and 64 continue as long as the plunger 98 is in the position shown in FIG. Assume that a there is sufficient pressure to open the valve 84, the pressure medium passes from the flow path 62 through

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Patent attorney DIpl.-Ing. Hans Gründi - Regensburg, Lessingstrasse 10

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Sheet 'for writing ¹ ^ *' ^ = «-ν» _to:

the flow paths 54, 56, 126 and 58 to the piston chamber 50 at the same time as the pressure from flow path 64 through restriction port 142 to an annular chamber which passes through an edge 146 and the stop ring 134 is formed.

Thus, when the spring 138 holds the piston 132 in the position shown and equal pressures act in the chamber 50 on the full piston surface and in the chamber 144 on the differential piston surface, the predominant force holds the piston in the position shown and the pedal in the raised position Position, as the accumulator pressure builds up to a predetermined value. This same pressure holds the ball 120 on the seat 122 with the support of the spring 118, which acts via the tappet 116. This same pressure, which acts on the right-hand end of the tappet 98 with the support of the spring 128 via the ball 130, is counteracted by the loading of the spring 106. When the predetermined pressure is reached, the plunger 98 moves as far as the left, non-seated ball 120 to connect the chamber 50 to the container. At the same time, the plunger 98 £ 110 can be seated moved when behind the ball 120 reduces the pressure and the resultant load is reduced further to the left, whereby the ball 130 on the surface. Since the accumulator pressure achieved is still in communication with the differential surface of the piston 132 via an opening 142, it continues to the left and lowers the 809811/0225

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Patent attorney Dlpl.-Ing. Hans Gründlch - Regensburg, Lessingstrasse 10

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Pedal to the position assumed with full servo power will. The mouth 142 "limits the speed at which the pedal can be raised or lowered. Since the diameter on which the ball 130 rests is slightly larger than the area of the plunger 98 that is subjected to the pressure, the ball 130 remains at normal pressures of the accumulator system engaged and the pedal in the reduced servo pitch, until the accumulator pressure drops slightly below the pressure, required to lower the pedal.

This lower pressure, which is slightly below the preload pressure of the accumulator, reduces the forces on the ball 130 and the plunger 98 until they are overcome by the spring 106, whereby the valve system on the in Pig. 2 is returned and pressure from the accumulator is reconnected to chamber 50 to raise the pedal to the no servo pressure position.

To refill pressure medium within the piston chamber 50, such as in an out of action condition when the piston is after is moved to the right to the position shown by Fig. 2, the spring 92 which controls the valve 86 is intentionally light selected so that a pressure below atmospheric pressure opens the valve 66 and the container opening 70 via the valve chamber connects to the chamber 50.

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Patent attorney DipL-tng. Han · Gründi - Regensburg, Lessingstrasse 10

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FIGS. 3 and 4 show a further embodiment a pedal lifting device in a faulty servo brake shown with actuation device, with the help of which a manual actuation as well as a servo actuation of the braking system is possible. In detail, a servo braking device is shown with a housing 148, the has a one-piece container 150. The device further includes a sliding piston 152, which is arranged to divide a portion of the housing into a container chamber 154 and an accumulator chamber 156 on Scope of the piston 152 divides. At the same time, the piston forms a chamber 158 with a variable volume between the Piston 152 and an outlet port 160 which are drivingly with a wheel cylinder, as shown in Fig. 1, for example is * connected.

To increase the pressure in the chamber 158, an internal sub Pressurized medium is introduced or in which the piston 152 is moved so that it increases the volume of the chamber 158 reduced, the piston with a (not shown) brake pedal via a rod 162 with the interposition of a Rubber washer 164 or similar resilient arrangement of plunger 166 and C-shaped plate 168 connected; the plate 168 is arranged over a narrowing of the plunger and has a smaller width than the axial Length of the ram narrowing. The plate is in the piston 152

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Patent attorney DIpl.-Ing. Hans Begrtdi - Regensburg, LessIngstrasse 10 _

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held by means of a locking ring 170 and a spring 172 is arranged between plate and locking ring 174 so that the plunger 166 is pushed to the right in FIG.

A stop ring 176, which is arranged in the right end of the housing 148 (Fig. 2), forms a rear stop for the piston 152 and additionally attaches an end component 178 to the housing 148. The end component has a piston chamber 180 and a valve chamber 182. In the chamber 180 is a piston 184 slidably attached. The piston 184 includes front and rear tubular lugs 186 and 188. The front tubular Lug 186 is arranged to slide over the outer walls of plunger 166 and strike plate 168. A spring I90 is between the piston 184 and the Stop ring 176 is set and presses against the piston 184 so that it rests against an end wall 192 of the end member 178, as can be seen in FIG. 3. In this position, the rod 162 is in its fully extended position, with a maximum brake pedal travel is reached.

In normal operation, the driver exerts pressure on a brake pedal -off and moves the rod 162 into the interior of the housing 148 and the end member 178. This in turn moves the plunger 166, which is one provided with an axial bore Extension carries; thereby the extension lies respectively. the stem 194 on a ball valve 196 that is in equilibrium is. This closes the connection of the chamber

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Patent attorney Dlpl.-Ing. Hant Gründlch - Regensburg, Leulngttraße 10

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158 to container 150 which passes through flow path 198

in the shaft

in the piston 152, the flow path / 194, the radial flow paths 200 in the plunger 166, the recess 202 in the C-plate or in the insert 168, the locking ring 170 and the radial openings 204 in the piston 152 to the container chamber was established, from where the connection to the container 150 leads over the flow path 206.

A further inward movement of the aforementioned component causes the ball valve 196 to rise from its seat, so that pressure medium can exit from the chamber 156 into the chamber and through an opening 160 from it, so that a A device responding to pressure is actuated, e.g. to lengthen the piston rods of a wheel cylinder to such an extent that • Engage in brake shoes with a brake hub. In case of print failure in the chamber 156, for example in the event of an interruption in a feed line, a shut-off valve 208 switches the pressure medium inlet opening 210, which supplies the chamber 156 with medium that divides under pressure, and the plunger. 166 sets • I against the C-shaped plate or insert 168, which piston 152 pressurizes chamber 158 to close the pressure responsive device in the manner indicated actuate.

When the pressure applied to shut-off valve 208 is over a wide range of pressures, such as in a system

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Patent attorney Dtpl.-Ing. Hans Gründlch - Regensburg, Lessingstrasse 10

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which is similar to that associated with the braking device of Fig. 1, the pressure is also on the end member 178 and abandoned in particular to the inlet port 212 (see. Fig. 4). Upon entering opening 212 and upon flowing through by means of a limiting component 214, this applies below Pressurized medium on a slide valve 216, which is biased to the left in Fig. 4, to a flow path 218 against to close off the pressure flow and connect a flow path 220 to flow path 218 * so that these positions to be maintained even in the absence of a sufficiently high pressure, a spring 222 is provided which is a ball valve lifts off from a seat 226 with the aid of a plunger or rod 228. Thus, if the pressure at port 212 is sufficient is large to move the 'Jleitventil 216 to the right. (Fig. 4), the ball valve rests on its seat and a pressure flow is generated in the flow path 218 while the container connection through the space 230 between the ram and the rear tubular extension 186 (Fig. 3), the Chamber 180 and flow path 220 is terminated.

If the accumulator pressure falls below a certain value (slightly above the accumulator preload pressure), the Force that presses the ball 224 on the part 226 by the Overcome spring 222, the ball is removed from the seat and take the valve position and the flow connection the position shown in Fig. 4, the chamber. 192

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Patent attorney DIpl.-lng. Han «Beschich - Regentburg, Lessingstrasse 10« i / onrr »n Sheet 'J for writing the I? IUOP / W

to the container is open. Then the brake piston 152 and the position control valve 184 move to the right (Fig. 3), u.zw. as a function of spring forces which are reduced by a spring 234 in the chamber 158 and the spring 190 as well as the Accumulator pressure, which acts on the chamber 156 on the differential surface of the piston 152, can be generated. When the pressure has been reduced to about the battery bias in this manner, the piston 152 J will move to the right (and the pedal will be raised to the non-servo position), although at this time a brake application is made. The brake pedal thus lifts off due to the expected brake actuation Hand on, although at the time of the impending loss of the auxiliary the brakes come into action.

Thus, the differential area on the piston 152 in the chamber 156 (and thus the resulting force effect) is smaller than the area on the piston 184 in the chamber 180, whereby the pistons are pushed against their springs by the pressure in both chambers pressed left. The pressure medium in chamber 156 is enclosed between shut-off valve 208 and valve 196, Da the pistons move to the left, the pressure in chamber 156 exceeds the accumulator pressure and is thereby released, that the high pressure check valve 232 stands out from its seat (Fig. 3). As a result, the piston 184 is after moved inside or to the left (Fig. 3) so that the inside of the

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Patent attorney DIpl.-Ing. Hans Gründidi - Regensburg, Lessingstrasse 10 “ . _ _ _ Sheet 1 4 for the letter of 1 5. 10.6 3 / W ^en:

Housing 148 is moved in a similar manner and together, which is also due to the abutment of the rear tubular extension takes place on the C-shaped plate or insert 168. The travel of the brake pedal is thus reduced by the Pedal is pulled inwards. If the auxiliary power fails, the slide valve 216 causes the tank pressure to be restored is applied to flow path 218 to increase the pressure balance both sides of piston 184, causing spring 190 and spring 234 to bring the pedal to a position in which a corresponding leverage for manual operation is achieved will.

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Claims (1)

P.A. 664 288 * 10/17/63 15 10/15/63 / W AS U30568 Claims Hydraulic servo braking system with a control valve which is operated by a brake pedal lever to control the pressure from a hydraulic pressure medium source to a brake circuit and which is received by the piston of a hydraulic pump connected to the brake circuit, with Λ this piston being carried by the Control valve introduced into the brake circuit pressure is held in a rigid, retracted position as long as the effect of this pressure on the valve control member balances the effect of the brake pedal lever on this member, and the piston is driven by the brake pedal lever in such a way that the pressure in the Brake circuit is increased when the pressure is not so high that it compensates for the action of the brake pedal lever, characterized in that the brake pedal lever (4-0) is drivingly connected to the piston (132, 184) of a hydraulic motor, the operation of which is controlled by a Controller is controlled, the brake pedal lever as long as in a lower Ren position holds, as the pressure of the hydraulic pressure medium source (14) exceeds this value, and which moves the brake pedal lever into the higher position when the pressure of the hydraulic pressure medium source falls below a predetermined value. Brake system according to claim 1, characterized in that the 80981 1/0225 - 15 - 15.10.63 / W / 16 Piston (132, 184) of the hydraulic motor is held in a first position, which is the lower position of the brake pedal lever by the hydraulic pressure from the source (14) corresponds to the ulrd given to the engine via the regulator, as long as this pressure exceeds the predetermined value and that a spring (138, 190) moves the piston to a second position moved which corresponds to the higher position of the brake pedal lever when the pressure from the source is below this predetermined one Value falls. Brake system according to Claim 1 or 2, characterized in that the brake pedal lever (40) is pivotable with a piston rod (30, 140) is connected, which in turn is connected to the control valve, pivotable on a lever (32) is attached, which is rotatable about a fixed axis and connected to the piston (132) of the hydraulic motor and of is operated on him. Brake system according to Claim 1 or 2, characterized in that the hydraulic motor is arranged behind the hydraulic pump and that the piston (152) of the pump in the event that no braking force is exerted on the brake pedal lever, is brought into engagement by a spring (234) with the piston (184) of the hydraulic motor, so that both pistons move together and push the brake pedal lever through the piston (152) -16- 17 10/15/63 / W Αϊ the pump moved to the lower or higher position depending on the level of the pressure of the hydraulic pressure source will. Brake system according to claim 1 or one of the following, characterized in that the controller has a ball valve and a slide valve in series between the hydraulic pressure medium source and the hydraulic drive and that the pressure of the pressure medium source on the plunger (98, .216) of the slide valve opposite to Action of a bias spring (106, 222) acts to successively move the plunger and valve ball (130 _} 224) to their closed positions when the pressure from the pressure source rises from a lower to a higher value than the predetermined value. - 17 - 8098 1 1 / n 9