DE102015115489B4 - Spring-loaded brake cylinder with double-sealed bayonet lock - Google Patents

Abstract

Pneumatic spring-actuated brake cylinder (3) for vehicle brake systems, with a) a spring-actuated brake piston (7) which can be moved in the axial direction and actuated by an accumulator spring (9) and which is on one side of a pressure chamber (11) and on the opposite side of an accumulator spring (9) receiving the spring chamber (15), the storage spring (9) being supported on the one hand on the spring-loaded brake piston (7) and on the other hand on a base of the spring-loaded brake cylinder (3),b) a supporting and connecting wall (5) with an opening ( 19), through which a spring brake piston rod (17) connected to the spring brake piston (7) extends in the axial direction, c) a bayonet connection (27) between an end section (29) of the spring brake cylinder (3) arranged in the area of the pressure chamber (11) and a first flange part (31) of the support and connection wall (5), wherein the bayonet connection (27) on a first annular surface (33) of the first Flange part (31) of the supporting and connecting wall (5) has first locking elements and on a second annular surface (35) of the end section (29) of the spring-loaded brake cylinder (3) has second locking elements, with at least partial overlapping of the first annular surface (33) and the second ring surface (35) behind which the first and second locking elements engage in a form-fitting manner, and withd) a sealing arrangement (37) in the area of the bayonet connection (27), which has a sealing effect between the pressure chamber (11) and the atmosphere (43) surrounding the spring-loaded brake cylinder (3). , whereine) the end section (29) of the spring brake cylinder (3) overlaps the first flange part (31) of the supporting and connecting wall (5), and whereinf) the sealing arrangement (37) comprises a first elastic annular seal (39) which in a first groove (51) of a radially outer peripheral surface (47) of the first flange part (31) of the supporting and connecting wall (5), characterized in that et thatg) the sealing arrangement (37) comprises a second elastic ring seal (41) which is accommodated in a second groove (53) of the radially outer peripheral surface (47) of the first flange part (31) of the supporting and connecting wall (5), whereinh) viewed in a direction from the atmosphere (43) into the pressure chamber (11), the first elastic ring seal (39) is arranged upstream of the bayonet connection (27) and the second elastic ring seal (41) is arranged downstream of the bayonet connection (27), and whereini) the first ring seal (39) and the second ring seal (41) are each clamped radially between the first flange part (31) of the supporting and connecting wall (5) and the end section (29) of the spring brake cylinder (3).

Description

The invention relates to a pneumatic spring-loaded brake cylinder for vehicle brake systems, according to the preamble of patent claim 1, and a method for producing a spring-loaded brake cylinder according to the preamble of patent claim 5. The problem with such spring-loaded brake cylinders is that the pressurized and vented pressure chamber must be sealed off from the atmosphere , but the bayonet connection is arranged between the atmosphere and the pressure chamber. The sealing arrangement arranged in the area of the bayonet connection should therefore prevent a flow between the pressure chamber and that of the atmosphere. In particular, the sealing arrangement is intended to prevent dust and dirt from penetrating into the pressure chamber, since such dirt could then get into the compressed air system of the brake system.

A generic spring brake cylinder is, for example DE 41 35 943 A1 known, wherein the bayonet connection is formed between an end portion of the spring brake cylinder and a flange of a supporting and connecting wall. A single sealing ring acts as a sealing arrangement, which is arranged downstream of the bayonet connection as viewed from the atmosphere into the pressure chamber. The sealing ring is accommodated in a groove in the flange of the supporting and connecting wall.

According to DE 35 43 365 A1 a cylinder housing of a spring-actuated brake cylinder is connected to an intermediate flange by a bayonet connection, with a sealing element being arranged in a circumferential groove in the intermediate flange and the bayonet connection being arranged on the pressure-loaded side of the sealing element. The circumferential groove in the intermediate flange for the sealing element is combined with a recess, which is part of the bayonet connection.

object of the invention

In contrast, the object of the invention is to develop a spring-loaded brake cylinder of the type mentioned at the outset in such a way that it ensures improved sealing.

This object is solved by the features of claim 1 and claim 5.

Disclosure of Invention

The invention is based on a pneumatic spring-loaded brake cylinder for vehicle brake systems, with a spring-loaded brake piston which can be moved in the axial direction and can be actuated by an accumulator spring, which is delimited on one side by a pressure chamber and on the opposite side by a spring chamber accommodating the accumulator spring, with the storage spring (9) is supported on the one hand on the spring-loaded brake piston and on the other hand on a base of the spring-loaded brake cylinder, a support and connection wall with an opening through which a spring-loaded brake piston rod connected to the spring-loaded brake piston extends in the axial direction, a bayonet connection between an end section arranged in the area of the pressure chamber of the spring-loaded brake cylinder and a first flange part of the supporting and connecting wall, the bayonet connection on a first annular surface of the first flange part of the supporting and connecting wall first locking element elements and has second locking elements on a second annular surface of the end section of the spring-loaded brake cylinder, with the first and second locking elements engaging behind one another in a form-fitting manner with at least partial overlapping of the first annular surface and the second annular surface, and with a sealing arrangement in the area of the bayonet connection, which is located between the pressure chamber and the atmosphere surrounding the spring-actuated brake cylinder has a sealing effect, with the end section of the spring-actuated brake cylinder engaging over the first flange part of the supporting and connecting wall, and with the sealing arrangement comprising a first elastic ring seal which is in a first groove of a radially outer peripheral surface of the first flange part of the supporting and connecting wall is included.

According to the invention, it is provided that the sealing arrangement comprises a second elastic ring seal, which is accommodated in a second groove of the radially outer peripheral surface of the first flange part of the supporting and connecting wall, with the first elastic ring seal of the bayonet connection viewed in a direction from the atmosphere into the pressure chamber upstream and the second elastic ring seal is arranged downstream of the bayonet connection, and wherein the first ring seal and the second ring seal are each clamped radially between the first flange part of the support and connection wall and the end section of the spring brake cylinder.

In other words, the bayonet connection of the first elastic ring seal and the second elastic ring seal is interposed with respect to an imaginary connection between the atmosphere and the pressure chamber.

Because the first ring seal and the second ring seal are each between the first flange part of the support and connection wall and the end section of the spring brake cylinder are radially clamped, a high sealing effect is created. The extent to which the ring seals are clamped is determined by a person skilled in the art, taking into account the elasticity and geometry of the ring seals, for example made of an elastomer.

Since the first elastic ring seal is arranged in front of the bayonet connection in a direction from the atmosphere into the pressure chamber, the bayonet connection is protected against the ingress of moisture, dirt and dust, as a result of which there is a reduced tendency to corrosion. Then the bayonet connection can be loosened more easily for maintenance and repair purposes. Overall, therefore, the first elastic ring seal serves primarily to keep moisture, dirt and dust away from the locking elements of the bayonet connection or from the pressure chamber.

Tightness is increased by snuggling up the elastic ring seals on the respective groove base. Furthermore, the ring seals are fixed in their position, which is advantageous for translational and rotational movements during assembly of the bayonet connection.

Because the first elastic ring seal is arranged upstream of the bayonet connection and the second elastic ring seal is arranged downstream of the bayonet connection, viewed in a direction from the atmosphere into the pressure chamber, a type of labyrinth seal with multiple flow deflection is also created. If, contrary to expectations, compressed air coming from the pressure chamber should pass the second ring seal, the compressed air flow will be deflected several times by the locking elements of the bayonet connection and the first elastic ring seal, whereby it "runs dead" so that in the end no or only very little compressed air comes out of the Pressure chamber could escape.

Particularly preferably, starting from the two ring surfaces of the bayonet connection, the first elastic ring seal faces the atmosphere and the at least one second elastic ring seal faces the pressure chamber.

1. a) Positionieren der ersten elastischen Ringdichtung in der ersten Nut und der zweiten elastischen Ringdichtung in der zweiten Nut an einer radial äußeren Umfangsfläche des ersten Flanschteils der Trag- und Anschlusswand derart, dass die erste Ringfläche mit den ersten Verriegelungselementen der ersten elastischen Ringdichtung und der zweiten elastischen Ringdichtung zwischengeordnet ist,
2. b) translatorisches Einführen des Flanschteils der Trag- und Anschlusswand in den Endabschnitt des Federspeicherbremszylinders unter axialem Eingriff der ersten und zweiten Verriegelungselemente und unter radialem Klemmen der ersten elastischen Ringdichtung und der zweiten elastischen Ringdichtung zwischen dem ersten Flanschteil der Trag- und Anschlusswand und dem Endabschnitt des Federspeicherbremszylinders,
3. c) Verdrehen von Federspeicherspeicherbremszylinder und Trag- und Anschlusswand gegeneinander, derart, dass sich die ersten und zweiten Verriegelungselemente formschlüssig hintergreifen.

The method for producing such a spring-loaded brake cylinder then includes at least the following steps:

1. a) Positioning the first elastic ring seal in the first groove and the second elastic ring seal in the second groove on a radially outer peripheral surface of the first flange part of the supporting and connecting wall in such a way that the first annular surface with the first locking elements of the first elastic ring seal and the second elastic ring seal is interposed,
2. b) translational insertion of the flange part of the supporting and connecting wall into the end section of the spring brake cylinder with axial engagement of the first and second locking elements and with radial clamping of the first elastic ring seal and the second elastic ring seal between the first flange part of the supporting and connecting wall and the end section of the spring brake cylinder,
3. c) Twisting of the spring-loaded brake cylinder and the supporting and connecting wall against one another in such a way that the first and second locking elements engage behind one another in a form-fitting manner.

As part of the relative rotation according to step c), the first and second ring seals can then each slide along the contacted surfaces on the first flange part of the support and connection wall or on the end section of the spring-loaded brake cylinder.

Particularly preferably, the first elastic ring seal and the second elastic ring seal each have a circular cross section, which means that they are easy to manufacture and inexpensive.

The spring-actuated brake cylinder, together with a service brake cylinder, particularly preferably forms a combined service brake and spring-actuated brake cylinder, with one or more service brake pistons or service brake membranes which are arranged in the service brake cylinder and can be actuated by a pressure medium, which or which are connected to a service brake piston rod which projects out of the service brake cylinder and acts on brake actuation elements There is an operative connection, whereby the spring-loaded brake piston rod protruding through the opening in the supporting and connecting wall interacts with the service brake piston or with the service brake membrane and one end section of the service brake cylinder is connected to a second flange part of the supporting and connecting wall, pointing away from the spring-loaded brake cylinder. The connection between the second flange part of the support and connection wall and the end section of the service brake cylinder is preferably formed by a clamping strap or by a bead.

character list

• 1 eine Querschnittsdarstellung eines Teils eines kombinierten Betriebsbrems- und Federspeicherbremszylinders gemäß einer bevorzugten Ausführungsform;
• 2 einen vergrößerten Ausschnitt aus 1 im Bereich einer Bajonettverbindung zwischen dem Federspeicherbremszylinder und einer Trag- und Anschlusswand.

In the following, the invention will be exemplified with reference to the drawing. In the drawing shows

• 1 a cross-sectional view of part of a combined service brake and spring accumulator brake cylinder according to a preferred embodiment;
• 2 an enlarged section 1 in the area of a bayonet connection between the spring brake cylinder and a supporting and connecting wall.

Description of the embodiment

In 1 The drawing shows a combined service brake and spring-loaded brake cylinder, hereinafter referred to as combination cylinder 1, to explain the invention by way of example. The combination cylinder 1 consists of a service brake cylinder (not shown here) and a spring-loaded brake cylinder 3 structurally and functionally connected to it carries. In the event that the spring-loaded brake cylinder 3 is designed separately and without a service brake cylinder, the supporting and connecting wall 5 forms an outer wall or a base or end of the spring-loaded brake cylinder 3.

A spring-loaded brake is actuated by means of the spring-loaded brake cylinder 3, e.g. as part of a pneumatic or electro-pneumatic parking or parking brake, and a pneumatic or electro-pneumatic service brake by means of the service brake cylinder. In this respect, these brake cylinders form part of the brakes mentioned.

A spring-actuated brake piston 7 is arranged in an axially displaceable manner within the spring-actuated brake cylinder 3 , with an accumulator spring 9 resting on one side of the spring-actuated brake piston 7 . The storage spring 9 is supported on its opposite side on the bottom of the spring brake cylinder 3 . In accordance with 1 Pressure chamber 11, which exists on the left with respect to the spring-loaded brake piston 7, opens out into an inlet 13, through which compressed air is introduced, in order to inflate the spring-loaded brake piston 7 under the tension of the storage spring 9 1 to the right to release the spring-loaded brake. With this displacement of the spring-loaded brake piston 7, the air, which is within a spring chamber 15 accommodating the storage spring 9, z. B. pressed out via a (not shown) check valve. If, on the other hand, the pressure in the pressure chamber 11 of the spring-loaded brake cylinder 3 is relieved for the purpose of braking when a known valve connected to the inlet 13 of the pressure chamber 11 is actuated, then the spring-loaded spring 9 can move the spring-loaded brake piston 7 as shown in FIG 1 to the left in order to apply the spring-loaded brake.

The spring-actuated brake piston 7 is connected to a spring-actuated brake piston rod 17, which extends through a central opening 19 in the support and connection wall 5 into the region of a pressure chamber 21 of the service brake cylinder. A seal 23 inserted in the opening 19 of the support and connection wall 5 seals off the pressure chambers 11 and 21 during the axial movements of the spring brake piston rod 17 . The wall of the spring brake cylinder 3 is preferably made of steel or aluminum.

An inlet 25 opens into the pressure chamber 21 of the service brake cylinder, via which inlet or outlet compressed air is used to actuate the service brake cylinder. The compressed air acts, for example, on a membrane plate of a membrane that is used inside the service brake cylinder and is not shown here. The membrane plate is connected to a push rod, also not shown here, which interacts with a brake actuation mechanism outside of the combination cylinder 1 . This can, for example, be the actuation parts of a disc brake of a motor vehicle.

A bayonet connection 27 is provided for the detachable connection of the spring brake cylinder 3 to the support and connection wall 5 . The bayonet connection 27 is more precisely between an end section 29 of the spring-loaded brake cylinder 3 arranged in the area of the pressure chamber 11 and a first flange part 31 of the supporting and connecting wall 5. The end section 29 of the spring-loaded brake cylinder 3 preferably overlaps the first flange part 31 of the supporting and connecting wall 5, in particular axially and overlaps this radially. Alternatively, the first flange part 31 of the supporting and connecting wall 5 could also overlap the end section 29 of the spring brake cylinder 3 axially and radially.

The bayonet connection 27 has first locking elements (not visible here) on a first annular surface 33 of the first flange part 31 of the supporting and connecting wall 5 and second locking elements (also not visible here) on a second annular surface 35 of the end section 29 of the spring brake cylinder 3, with at least partial overlapping of the first annular surface 33 and the second annular surface 35 engage behind the first and second locking elements in a form-fitting manner in order to form the bayonet connection.

As in DE 10 2011 115 122 A1 locking segments projecting radially outwards and recess segments shaped radially inwards can be formed on the first and second annular surfaces 33, 35, with locking segments and recess segments alternating continuously over the circumference and each having the same segment arc length. Alternatively, any type of locking element or combination of locking elements is conceivable, through which a bayonet catch or a bayonet connection 27 can come about as a result of a translation and a subsequent rotation.

The service brake cylinder, which is not shown here, is connected to a second flange part 55 of the supporting and connecting wall 5, for example by a clamping strap or a flanged connection.

A sealing arrangement 37 is provided in the region of the bayonet connection 27 to seal off the pressure chamber 11 from the atmosphere 43 . The sealing arrangement 37 includes a first elastic ring seal 39 and a second elastic ring seal 41, with the first elastic ring seal 39 being arranged upstream of the bayonet connection 27 and the second elastic ring seal 41 being arranged downstream of the bayonet connection 27 in a direction from the atmosphere 43 into the pressure chamber 11. The upstream and downstream arrangement in relation to the bayonet connection 27 relates here, for example, to the axial direction which is defined by a central axis 45 of the spring-loaded brake cylinder 3 and here also by the direction of movement of the spring-loaded brake piston 7 .

Like in particular 2 shows, the first ring seal 39 and the second ring seal 41 are each radially clamped between a radially outer peripheral surface 47 of the first flange part 31 of the support and connection wall 5 and a radially inner peripheral surface 49 of the end section 29 of the spring brake cylinder 3.

Particularly preferably, the first elastic ring seal 39 and the second elastic ring seal 41 each have a circular cross section. Furthermore, the first elastic ring seal 39 and the second elastic ring seal 41 are each accommodated in a groove 51 or 53, for example in the radially outer peripheral surface 47 of the first flange part 31 of the supporting and connecting wall 5, namely in a first groove 51 and in a second groove 53. It is based on 2 clear that the circular cross section of the first elastic ring seal 39 and the second elastic ring seal 41 in the clamped state no longer corresponds to a pure circular shape, but has flat sections with surface contact.

The first annular surface 33 with the first locking elements of the bayonet connection 27 is then on the radially outer peripheral surface 47 of the first flange part 31 of the supporting and connecting wall 7 and the second annular surface 35 with the second locking elements of the bayonet connection 27 on the radially inner peripheral surface 49 of the end section 29 of the spring brake cylinder 3 is arranged. At least the end section 29 of the spring brake cylinder 3 is cylindrical, as is the first flange part 31 of the supporting and connecting wall 5.

The first elastic ring seal 39 is preferably designed in such a way that it prevents dirt, dust and moisture from penetrating into the bayonet connection 27 or into the pressure chamber 11, while the second elastic ring seal 41 is preferably designed in such a way that it protects the pressure chamber from the atmosphere sealed pressure-tight. These properties can be achieved, for example, by a targeted selection of the geometry and elasticity of the ring seals 39, 41.

Against this background, the spring brake cylinder 3 is connected to the supporting and connecting wall 5 as follows, or the bayonet connection 27 is produced as follows.

First, the first elastic ring seal 39 in the first groove 51 and the second elastic ring seal 41 in the second groove 53 are installed in the first flange part 31, for example by elastically expanding and then contracting. The first ring surface 33 with the first locking elements of the bayonet connection 27 is arranged between the first elastic ring seal 39 and the second elastic ring seal 41 .

Then the first flange part 31 of the supporting and connecting wall 5 is fitted into the end section 29 of the spring brake cylinder 3 with axial engagement of the first and second locking elements and with radial clamping of the first elastic ring seal 39 and the second elastic ring seal 41 between the radially outer peripheral surface 47 of the first Flange part 31 of the support and connection wall 5 and the radially inner peripheral surface 49 of the end portion 29 of the spring-loaded brake cylinder 3 is introduced in a translatory manner. This step therefore corresponds to the typical translational movement when making a bayonet connection.

Subsequently, the spring-loaded brake cylinder 3 and the supporting and connecting wall 5 are rotated in relation to one another in such a way that the first and second locking elements of the bayonet connection 27 can engage behind one another in a form-fitting manner. This step then corresponds to the typical rotational movement that follows the translational movement when producing a bayonet connection.

The elastic compression of the two ring seals 39, 41 in the radial direction between the first flange part 31 of the supporting and connecting wall 5 and the end section 29 of the spring-loaded brake cylinder 3 ensures on the one hand that the pressure chamber 11 is sealed off from the atmosphere 43 and on the other hand that there is a frictional connection between the first Flange part 31 of the support and connection wall 5 and the end section 29 of the spring-loaded brake cylinder 3, which prevents loosening of the bayonet connection 27.

Reference List

1

combination cylinder

3

spring brake cylinder

5

supporting and connection wall

7

spring brake piston

9

storage spring

11

pressure chamber

13

inlet

15

spring chamber

17

Spring brake piston rod

19

opening

21

pressure chamber

23

poetry

25

inlet

27

bayonet connection

29

end section

31

first flange part

33

first ring face

35

second ring surface

37

sealing arrangement

39

first ring seal

41

second ring seal

43

the atmosphere

45

central axis

47

radially outer peripheral surface

49

radially inner peripheral surface

51

first groove

53

second groove

55

second flange part

Claims (5)

Pneumatic spring-actuated brake cylinder (3) for vehicle brake systems, having a) a spring-actuated brake piston (7) which can be moved in the axial direction and actuated by an accumulator spring (9) and which is on one side of a pressure chamber (11) and on the opposite side of a die spring chamber (15) accommodating the accumulator spring (9), the accumulator spring (9) being supported on the one hand on the spring-actuated brake piston (7) and on the other hand on a base of the spring-actuated brake cylinder (3), b) a supporting and connecting wall (5) with an opening (19) through which a spring brake piston rod (17) connected to the spring brake piston (7) extends in the axial direction, c) a bayonet connection (27) between an end section (29) of the spring brake cylinder (3) arranged in the area of the pressure chamber (11) and a first flange part (31) of the supporting and connecting wall (5), wherein the bayonet connection (27) on a first annular surface (33) of the first th flange part (31) of the supporting and connecting wall (5) has first locking elements and on a second annular surface (35) of the end section (29) of the spring brake cylinder (3) has second locking elements, with at least partial overlapping of the first annular surface (33) and the second annular surface (35), the first and second locking elements engage behind in a form-fitting manner, and with d) a sealing arrangement (37) in the area of the bayonet connection (27), which is located between the pressure chamber (11) and the atmosphere (43) surrounding the spring-loaded brake cylinder (3). has a sealing effect, wherein e) the end section (29) of the spring-loaded brake cylinder (3) overlaps the first flange part (31) of the supporting and connecting wall (5), and f) the sealing arrangement (37) comprises a first elastic ring seal (39), which is accommodated in a first groove (51) of a radially outer peripheral surface (47) of the first flange part (31) of the supporting and connecting wall (5), characterized in that characterized in that g) the sealing arrangement (37) comprises a second elastic ring seal (41) which is accommodated in a second groove (53) of the radially outer peripheral surface (47) of the first flange part (31) of the supporting and connecting wall (5). , where h) viewed in a direction from the atmosphere (43) into the pressure chamber (11), the first elastic Ring seal (39) is arranged upstream of the bayonet connection (27) and the second elastic ring seal (41) is arranged downstream of the bayonet connection (27), and i) the first ring seal (39) and the second ring seal (41) are each between the first flange part (31 ) of the support and connection wall (5) and the end section (29) of the spring brake cylinder (3) are radially clamped. Pneumatic spring brake cylinder (3) after claim 1 , characterized in that in relation to the bayonet connection (27), the first elastic ring seal (39) faces the atmosphere (43) and the second elastic ring seal (41) faces the pressure chamber (11). Pneumatic spring brake cylinder (3) according to one of the preceding claims, characterized in that the first elastic ring seal (39) and the second elastic ring seal (41) each have a circular cross section. Pneumatic spring-loaded brake cylinder (3) according to one of the preceding claims, characterized in that together with a service brake cylinder it forms a combined service brake and spring-loaded brake cylinder (1), with one or one service brake piston or service brake membrane which can be actuated by a pressure medium and is arranged in the service brake cylinder, which is or are in operative connection with a service brake piston rod which protrudes from the service brake cylinder and acts on brake actuation elements, the spring-loaded brake piston rod (17) protruding through the opening (19) in the supporting and connecting wall (5) interacting with the service brake piston or with the service brake membrane and a End section of the service brake cylinder is connected to a second flange part (55) of the supporting and connecting wall (5) pointing away from the spring-loaded brake cylinder (3). Method for producing a spring brake cylinder (3) according to one of the preceding claims, characterized by the following steps: a) Positioning the first elastic annular seal (33) in the first groove (51) and the second elastic annular seal (41) in the second groove (53 ) on the radially outer peripheral surface (47) of the first flange part (31) of the supporting and connecting wall (5) in such a way that the first annular surface (33) with the first locking elements of the first elastic annular seal (39) and the second elastic annular seal (41 ) is interposed, b) translational insertion of the first flange part (31) of the support and connection wall (5) into the end section (29) of the spring-loaded brake cylinder (3) with axial engagement of the first and second locking elements and with radial clamping of the first elastic ring seal ( 39) and the second elastic ring seal (41) between the first flange part (31) of the supporting and connecting wall (5) and the end cap section (29) of the spring-loaded brake cylinder (3), c) rotating the spring-loaded brake cylinder (3) and the supporting and connecting wall (5) against one another in such a way that the first and second locking elements engage behind one another in a form-fitting manner.

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