DE1906818A1 - Internally ventilated brake actuation device - Google Patents

Description

PATENT LAWYERS ^L -

DR. ING. KARL BOEHMERT DIPL-ING. ALBERT BOEHMERT

28 BREMEN FELDSTRASSE 24. TEL. (0421) 491760, 442551

File number: HWMUMIdUlIg ESS ^ E ^ A ^ K, o. 100.4.9 Named note: MGM BRAKES, IKC. Sign: MWI 28 Bremen, the 7- ^ br. 1969

MGM BRAKES, INC., Cloverdale, State of California (V.St.A.)

Internally ventilated brake actuation device

The invention relates to a brake operating device with a housing and one in one part of the housing movable, in the opening direction of the brake by pressure pre-tensioned brake actuation holes.

Vehicles equipped with pneumatic brakes usually have the main braking system in addition to them another auxiliary braking system that then use it finds when the vehicle is parked or if for any reason the brake pressure for the Main braking system is not available o

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Devices of this type generally have a normally compressed spring which, when released, has one for actuation the brakes of the vehicle are exerting sufficient force. The spring is usually compressed by Air is held in its compressed state, with the air either coming from the air reservoir of the main braking system or one of the main braking system is taken from a separate compressed air source · Bas compression of the spring is carried out by the compressed air of the auxiliary compressed air source in such a way that the air acts on a piston movable in a housing, the spring is arranged between the piston and the housing of the device.

When using the auxiliary braking system to apply the brakes, the air in the supply line of the auxiliary braking system flows into the atmosphere. This can either be done consciously by the operator or through breaks in the air line or through The pressure drops below a predetermined point at which the pressure is no longer sufficient, to keep the spring in its compressed state. This causes a The quick-closing valve connected to the air chamber of the auxiliary braking system opens and the air quickly opens let flow out of the chamber of the auxiliary braking system. This relieves the spring and exerts a Brake actuation force on the brakes of the vehicle from ο

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If you expand the spring, then the piston-like and moving in the housing of the device creates a negative pressure zone, the volume of which increases until the brakes are applied. This negative pressure zone must of course be filled by something air is removed from the area surrounding the device Eaum normally sucked in through an in-housing or in parts inserted therein vent into the low pressure zone β

Devices of this type are generally located in the line of the vehicle. ^{It is well known that very 1} ^ IeI dirt collects near the wheel of a vehicle _{, SaIs 6} Moisture ιϊε «1 derglo Since the usngebusgsluffc ia the Unterdnackg © se, some debris can easily be sucked with the air into the housing, in which these particles settle and the materials can attack _o This leads to contamination and / or corrosion of the device and has a short service life as a result.

The object of the present invention is therein »the above-mentioned disadvantages of the previously known devices of the type mentioned at the beginning to avoid and to create a brake actuator that is extremely simple in construction does not suck in through air laden with dirt, moisture, salt and the like and therefore does not is at risk from corrosion and pollution.

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This object is erfindungsgeciäß solved ₉ that the Brensbetätigungsstange arranged with a first in the housing, a first expandable chamber forming movable ivand is coupled, wherein the chamber ports for selectively introducing a 3trömungsmitteldrucks and movement of the wall and the brake actuating rod counter-acting in the opening direction of the pressure having; in that a second movable wall is provided which is arranged in the housing and forms a second expandable chamber therewith separated from the first chamber; that with the second movable wall a push rod leading through the second expandable chamber and reaching into the first expandable chamber is connected which transmits the brake actuation movement to the first moveable wall and the brake actuation rod and communicates with the first expandable chamber the second expandable chamber has an atmosphere communicating opening therethrough; that spring means act on the second movable TCand pressing in the brake actuation direction and connections are provided for optionally introducing a fluid pressure into the second expandable chamber in order to move the second movable wall counter to the brake actuation direction; and that a valve device is provided which is open when the second wall is displaced in the brake actuation direction, while it then seals the opening when pressure medium is introduced into the first expandable chamber in order to displace the first movable wall in the brake actuation direction.

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In the following part of the description, an embodiment of the subject matter of the invention is described with reference to drawings.
It show:

Fig. 1 is a vertical sectional view of the Brake actuator;

Pig. 2 is a vertical partial section of the

in Fig. 1 shown device in which the master cylinder is actuated;

3 shows a partial section of the valve arrangement, in which the valve body rests on the valve seat;

FIG. 4 is a view similar to FIG. 3;

in which the valve body is lifted from the valve seat;

Fig. 5 is a partial section along the line 5-5 in Fig. 3;

Fig. 6 is a sectional view taken along line 6-6 in Fig. 3;

7 shows a vertical partial section

the venting device in which the air flow during actuation of the auxiliary brake cylinder is shown; and

FIG. 8 shows a vertical partial section similar to FIG. 7, in which the air flow is shown after the brake cylinder in its hold-open position has returned.

As FIG. 1 shows, the brake actuation device 10 consists essentially of a master brake cylinder 12 and an auxiliary brake cylinder between the housing 16 of the master brake cylinder and the housing 18 of the auxiliary brake cylinder 14 is a first movable wall-forming membrane 20 sealing arranged. Inside the housing 16 of the

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In the main pulp cylinder, a Bresas actuation button 22 is provided which, for example, is pressed into the released position of the brake by means of the brake shoe return spring shown in Bichtuas and is resiliently operated in this position. At the end of the Bremsbetätigungsstaiige 22 © sitting in a substantially disc-shaped piston 24 "within the housing 16 is a diaphragm 26 _s angeoränet the sealing zwiseaea ämz housing i6 imü the brake operating Stang © 22 hdLlcleto The individual parts are arranged so» dlaß of the © bare. Surface of the diaphragm 20 acting air pressure, the piston 24 urged _s in turn the Bremsfeetätigungsstange 22 in BetätigiiEgs ^ Ichtung drüekt "For example, the Bremsbackenrückholfeder not shown acts in braking Oils & ASG extending movement! Of the piston 24 and the Bembran 20 against and pushes the piston 24 xmd the Diaphragm in a position corresponding to the released position of the brake.

The auxiliary brake cylinder 14 provides; an expandable or enlargeable chamber A dap _{8 to} which the housing 18 belongs, in which a movable partition is arranged. The housing 18 is provided with an ice plate 30 and has an end wall 32 which, with the membrane 20, forms an expandable first chamber B. forms, the cover plate JO forms else third chamber C. the end wall 32, the Kamuers a and B separated from each other and has an opening 32A at ₉ by a push rod 3 ^ MB <äurchführt "between the push rod 34 and the opening 324 is

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a seal 36 sealing against the pressure in the chambers is provided. The movable partition wall 28 has a circumferential sealing element 38 which comes to rest against the inner surface of the housing 18. The housing 16 and the end wall 32 form a first housing portion wätaencl the housing 16, the btirnwand 32 and the top plate 30 constitute a second housing portion * There are threaded connections 40 una 42 for transmitting the StrÖmungsmitteldrueks in the Kanaaern A ί2Εκ5 *? ο provided between the partition 28 and the B © ök · »plate 30 is a pressure spring 44 arranged _t the _β acts on the! partition in Bremstetätlguugsriehttmg

"The partition wall 28 has a üulsexiabschnitt 46 with a cavity 48 amr AisfaBsiame exerts thrust rod 34- to ^ A eiagesetzte in the Hülsesabscbnitt 46 seal 50 takes the öchialsstamge 34 sliding on ice threaded bolt 52 is in the end of the sleeves» portions 46 screwed JDareh the compression spring 44, the push rod 34 can be brought into contact with the membrane 20 by means of the threaded bolt which is movable together with the partition wall 28. The cover plate 30 has a sleeve part 30A ₄ surrounding the sleeve section 46, on the end of which a rubber cap 53 is placed. The rubber cap 53 has two openings 53A which allow the air to escape from the interior of the sleeve section 30A ic the atmosphere, but prevent an air flow in the opposite direction.

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In FIGS. 3 to 8, part of the push rod 34 is with the associated arrangement shown in detail. As can be seen from these figures, has the push rod 34- the sections 34A. and 34-B on. The portion 34-B is disk-shaped Part 34-C »The push rod 34 · has one of its Opening 54 leading one end to the other end This opening has on the one with the threaded bolt 52 connected end of the push rod 34- an angled Section 54-A, a cylindrical section 54-B, a conical section 54 <3 »a second cylindrical portion 54-D, the diameter of which is larger than that of the cylindrical portion 54-B, a third cylindrical portion 54E, a radial section 54-F, and a fourth cylindrical portion 54-G, the diameter of which is smaller than that of the cylindrical portion 54-E. On one surface of the disc-shaped part 34C a recess 54-H is provided which corresponds to the opening 54 · and with an opening 56 in disc-shaped Part 34-C communicates.

In the opening 54-of the valve member 58 is made of plastic ^ arranged, which has a main portion 58A and a protruding over the push rod 34 out section 58B _o On the side opposite the projecting portion side between the valve element 58 and the surface of the conical Section 54-C a spring 60 is provided. On the valve element 58 are a number of mating with the cylindrical portion 54-E

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Ribs 58C and ribs 58D fitting into the cylindrical section.

The valve element 58 further includes one made of rubber O-ring 58E made, which sits on the radial portion 54F of the opening 54. The radial Section 54F thus acts as one with the valve element 58 cooperating valve seal or a valve seat, so that a seal in the opening $ 4 is achieved when the O-ring is seated on the valve seat or radial section 547. The spring 60 presses the valve element 58 thereon Seat. '

The valve element 58 can be moved by the protruding portion 58B so that the 0-Hing 58E no longer in sealing contact with the radial section 54? The ribs 58C and 58D ensure guidance of the valve element 58 while it is out of the sealing position, in that of the O-ring 58E on the radial section 54? is moved to a position in which the O-ring 58S is removed from the radial portion 54F. Even if the valve element moves in the opposite direction, the ribs ensure reliable Guide. Passages are provided between the ribs 580 through which the openings 54 flowing air can pass through when the O-ring 58E is spaced from the radial portion 547 * Also between the ribs 58D Passages 61 are provided through which air flowing through the opening 5 ^ can pass if

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the O-ring 58E spaced from the radial section 54F is arranged. As "already stated, the opening 54 is then opened and enabled a flow through of the air when the O-ring 58E from the radial step 54-3? lifted off. The opening 54, on the other hand, is sealed when the O-bing 58E is on the radial section 54F sits on.

The sleeve section 46 has an opening 62 communicating with the interior of the sleeve part 30A and with the chamber C. The interior of the sleeve section 46 is in connection with the angled section 54A of the opening 54. It can be seen that the opening 54 leading through the expandable chamber A, on the one hand, with the expandable one Chamber B and on the other hand via the hollow ram 48 of the Sleeve section 46 as well as the © opening 62 with the one on the opposite side © of the partition 58 arranged chamber C communicates «During operation, the parts of the according to the invention are located Brake actuation device in the manner shown in FIG position shown «* The membrane 20 presses on the protruding section 58B and on the disk-shaped section 34C ", Ia of this position the O-ring 58E is lifted from the radial section 54F and the opening 54 is open over the Threaded connection 40, the chamber A is pressurized, and the partition 28 is estg © ge »& © r The force of the compression spring 44 moves the iVean di® chamber B is pressurized via the threaded connection 42, then the membrane 20 is against the piston 24

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moves and pushes the brake operating rod 22 in the pulp position. Since the membrane 20 is now moved away from the disk-shaped part 34C, the spring 60 has the effect that the O-ring 50E comes to rest on the radial section 5 ^ F and seals the opening 54 (FIG. 5). The force of the spring 60 is sufficient to overcome the pressure acting on the valve element 58 in the chamber B and to bring the O-ring into contact _{or the like}

The chamber B is sealed against this vifoise} it is ensured that the pressure prevailing in this chamber does not drop _or the pressure acting on the diaphragm 20 is reduced, then the individual parts of the brake actuation device return to the position shown in FIG .

If the auxiliary braking device or the auxiliary brake cylinder when parking the vehicle or because of displacement ^ say the main brake device or the main brake cylinder is to be actuated, then the Pressure in chamber A is switched off by means of a valve, not shown, or the pressure drops a pressure in the brake system and the partition 28 is of the compression spring 44 in the brake actuation direction emotional. The sleeve section 46 and the threaded bolt move together with the partition wall 28 52, which in turn, the push rod 54 against the membrane 20 presses. The membrane 20 transmits its Movement on the piston 24 and thus on the brake operating rod 22 to apply the brake.

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It should be noted that during this process, in which the disk-shaped part 34C of the push rod 34 rests against the membrane 22, the protruding section 58B comes into contact with the membrane 20 and thereby lifts the O-ring 58E from the radial section 54F so that the opening 54 is released. When the partition wall 28 moves downwards, a negative pressure is created in the chamber C. The arrows drawn in FIG. 7 indicate the air flow which, during operation of the device, compensates for the negative pressure or fills the vacuum. From the chamber B air flows over the top of the disk-shaped part 34C, through the opening 56, the opening 54, the cavity 48 and the opening 62 into the chamber C. The openings 53A prevent ambient air from equalizing the vacuum, as these openings do not allow air to flow through into the device. Therefore, no ambient air is sucked into the chamber C during the operation of the auxiliary brake device or the auxiliary brake cylinder 14.

In order to reset the auxiliary brake cylinder 14, the chamber A is pressurized via the threaded connection 40, and the partition wall 28 is moved in such a direction that the brake opens. The brake shoe return springs, not shown, act on the brake actuation rod 2.2 in order to keep the membrane 20 in contact with the disk-shaped part 340 and thus also with the protruding section 58B. During this process, the opening 54 is released "

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The .Pig. 8 show the air flow During this process, part of the air flows through the openings 53A, while the rest Part through openings 62 and 54 into the expandable Chamber B and from there flows through a quick-action valve, not shown.

It can be seen that no ambient air in can enter the interior of the device. It follows that there is a risk of contamination and corrosion, which could be caused by sucking in dirt, moisture and salt containing air, is completely avoided, whereby the life of the device is considerably extended.

The embodiment described above can be modified in many ways by a person skilled in the art without departing from the spirit of the invention.

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Claims (1)

M 1201 Expectations Ι «Brake operating device with a housing and one movable in a part of the housing and biased by pressure in the opening direction of the brake Brake operating rod, characterized in that that the brake operating rod (22) with a first movable one arranged in the housing (16, 18, JO) and forming a first expandable chamber (B) Wall (20) is coupled, wherein the chamber connections (42) for the optional introduction of a Flow of pressure and movement of the wall (20) and the brake actuating rod (22) against the pressure acting in the opening direction; that one arranged in the housing and with this a second one separated from the first chamber (B) a second movable wall (28) forming an expandable chamber (A) is provided; that with the second movable Wall (28) passing through the second expandable chamber (A) and into the first Extensible chamber (B) extending into the push rod (54) connected to the brake actuation movement on the first movable wall (20) and the brake operating rod (22) transmits and one with 515/03 909840/0983 communicating with the first expandable chamber (B), passing through the second expandable chamber (A), orifice connected to the atmosphere (54) having; that on the second movable., and (2S) in the brake actuation direction pressing spring devices (44) act and connections (40) for the optional introduction of a fluid pressure in the second expandable chamber (A) are provided to the second movable wall (28) against the Enclose brake actuation direction; and that "·. a valve device (58, 5 ^ F) is provided, which is open when the second wall (28) is displaced in the brake actuation direction, while ede is the opening (5 *) then seals if the pressure medium, is introduced into the first expandable chamber (B) around the first movable wall (20) in the brake actuation direction to move. 2. Brake actuation device according to claim 1, characterized in that the valve device (58 » 54F) a valve with a valve seat (5 * 1?) Arranged in the opening (54) and one in the opening arranged valve element (58) which cooperates sealingly with the valve seat when it rests on this; and that one at in the pulp actuation direction shifted second λ and holding the valve element at a distance from the valve seat Device (58B) is provided which presses the valve element onto the seat when fluid pressure is introduced into the first expandable chamber (B) is to move the first movable 'wall (20) in the brake actuation direction. 909840/0983 3. Brake actuation device according to claim 2, characterized in that the device holding the valve element (58) at a distance from the valve seat (54F) when the zv / pus wall is displaced in the brake actuation direction engages a section in the opening (54) of the push rod (34) (58B), which protrudes over the valve element and the push rod (34), protrudes into the opening (54) and contacts the first movable wall (20) when the push rod makes a brake actuation movement on the first movable wall and on the Brake operating rod (22) transmits <, 4o brake operating device according to claim 3, characterized characterized in that the by introducing pressure medium into the chamber (B) in the brake actuation direction displaced movable wall pressing the valve element (58) onto the valve seat (54F) Device one opposite to the protruding portion (58B) of the valve element arranged spring (60) between the valve element and a part of the opening (54) forming conical surface (54C). 5β brake operating device according to one of the claims 2 to 4, characterized in that a number of longitudinally extending Ribs (58C, 58D) are provided in a cylindrical portion (54E, 54G) of the opening (54) are slidably disposed and movement of the valve element from one seated on the valve seat (54F) Allow position in a lifted position from the seat. 909840/0983 6. Brake operating device according to one of the previous ones Claims, characterized in that the first movable wall has a membrane (20), and that the second movable wall is resiliently urging in the brake actuation direction The device has a spring (44) disposed between the housing and the second wall. 909840/098 3 Blank page