DE102016119771A1 - Compressed air actuated diaphragm brake cylinder for air brake systems of motor vehicles with reduced dead volume - Google Patents

Abstract

The invention relates to a pressure-actuated diaphragm brake cylinder (1, 100, 200) for air brake systems of motor vehicles miteinem a pressure-side housing part (3) and a pressure-facing housing part (2) and a diaphragm (4) arranged therebetween, the interior of the brake cylinder in two mutually sealed Spaces (11, 12) divides, of which a space is a ventilated and ventable pressure chamber (11), of the membrane (4) clamped a peripheral edge portion (41) between the pressure-side housing part (3) and the pressure-facing housing part (2) a circular central portion (13) is supported on a diaphragm plate (6) connected to a brake rod actuating piston rod (9), and a free loop portion (14) is disposed radially between the rim portion (41) and the central portion (13); Loop portion (14) of the membrane (4) projects axially into the space (12) deviating from the pressure chamber (11) and a Has loop bottom (15), and wherein the pressure-facing housing part (2) and the pressure-side housing part (3) in the region of the loop portion (14) of the membrane (4) partially axially overlap, wherein a protuberance (32) of the pressure-side housing part (3) in projects axially from the pressure chamber (11) deviating space (12).

Description

The invention relates to a compressed air-operated diaphragm brake cylinder for air brake systems of motor vehicles, according to the preamble of claim 1.

Compressed air actuated diaphragm brake cylinders, as are customary for actuating compressed air, drum or disc brakes in heavy commercial vehicles, have effective surface changes dependent on the stroke position. In this case, the effective area is understood to be the area of the membrane on which the pressure of the compressed air acts in the pressurizable and ventable compressed air chamber, which is delimited by the membrane.

This change in effective area is also undesirable because in the region of large cylinder stroke, that is to say precisely in a stroke region where large actuation forces are to be generated, the braking force increasingly decreases sharply. This stroke-dependent release of the braking force is also referred to as "mechanical fade". Cylinder types which do not have these stroke-dependent effective surface changes, such as e.g. Cylinder or cylinders equipped with rolling diaphragms are not readily applicable in conventional air brake systems, since both the usual in heavy vehicles S-cam drum brakes and air-actuated disc brakes are equipped with a Schwenkhebel- actuation on the actuating cylinder also pivoting or tilting push rod and causes pistons of up to +/- 5 degrees, which causes tilting and jamming of the guided pistons.

Another advantage of diaphragm cylinders is their insensitivity to contamination and extreme temperature fluctuations. These advantages have finally led to the almost exclusive use of diaphragm cylinders for the brake application in heavy commercial vehicles.

An improvement with respect to the described stroke-dependent effective surface change was, for example, according to the generic DE 101 09 515 B4 achieved with a design of the membrane, in which the effective area change was significantly reduced by a very wide loop portion of the membrane. However, the improvement thus achieved with regard to the effective surface constancy brings with it the disadvantage of a greatly increased harmful volume in the pressure chamber of the brake cylinder, wherein the harmful volume is limited at vented pressure chamber of the loop portion and the pressure-side housing part.

The present invention is based on the object to further develop a pressure-actuated diaphragm brake cylinder of the type described above such that at the greatest possible Wirkflächenkonstanz the Schadvolumens is largely reduced.

This object is achieved by the features of claim 1.

Disclosure of the invention

The invention is based on a pressure-actuated diaphragm brake cylinder for compressed air brake systems of motor vehicles with a pressure-side housing part and a pressure-facing housing part and a diaphragm arranged therebetween, which divides the interior of the brake cylinder into two mutually sealed chambers, of which a room is a ventilated and ventable pressure chamber in which a peripheral edge section is clamped by the diaphragm between the pressure-side housing part and the pressure-averted housing part, a circular central section is supported on a diaphragm plate connected to a piston mechanism actuating a brake mechanism and a free loop section is arranged radially between the edge section and the central section, wherein the Loop portion of the membrane projects axially into the space deviating from the pressure chamber and has a loop bottom, and wherein the pressure-facing housing part and the pressure-side housing Partially overlap axially in the region of the loop portion of the membrane, wherein a protuberance of the pressure-side housing part projects axially into the space deviating from the pressure chamber. In particular, the pressure-facing housing part engages over the pressure-side housing part on the outside.

The free loop section of the membrane is to be understood as meaning the loop-shaped or curved cross-section of the membrane, which is arranged radially between the clamped circumferential edge section and the circular central section supported by the central diaphragm plate.

According to the invention it is then provided that at least in the vented state of the pressure chamber, the protuberance of the pressure-side housing part of the loop bottom of the loop portion of the membrane contacted. In addition, this may also be the case in a partially ventilated or partially vented state or even in the fully ventilated state of the pressure chamber, depending on how the protuberance of the pressure-side housing part or the housing parts of the diaphragm brake cylinder is designed in total. Preferably, the contact of the protuberance of the pressure-side housing part with the loop bottom of the loop portion of the membrane is present only in the vented state of the pressure chamber, while in partial ventilation or partial venting and in the fully aerated state, no such contact is present.

In the diaphragm brake cylinder according to DE 101 09 515 B4 this is not the case, because there is an axial distance between the protuberance of the pressure-side housing part and the loop bottom of the loop portion of the membrane.

Therefore, the most far in the space deviating from the pressure chamber loop bottom of the loop portion of the protuberance of the pressure-side housing part is contacted, in particular in the vented state of the pressure chamber, which corresponds to a zero-stroke position in a diaphragm service brake cylinder. In addition, even in the partially or fully ventilated state of the pressure chamber, the protuberance of the pressure-side housing part can contact the loop bottom of the loop section of the membrane.

In other words, in the region of the loop portion of the membrane, the protuberance of the pressure-side housing part is drawn into the loop portion so far that the protuberance contacts the loop bottom. As a result, the membrane loop or the loop portion is better filled by the protuberance, whereby the Schadvolumen, i. the volume between the loop portion and the pressure-side housing part markedly reduced.

The reduction of the damaged volume then leads to a reduced compressed air requirement of the diaphragm brake cylinder and also improves the reaction time of the diaphragm brake cylinder to a ventilation or venting out.

In this case, the inner diameter of the protuberance must continue to be dimensioned so that the piston rod can perform together with the diaphragm plate so that these parts do not contact the protuberance or the wall of the pressure-side housing part during the actuating stroke.

The measures listed in the dependent claims advantageous refinements and improvements of the invention specified in the independent claims are possible.

According to a preferred embodiment, the housing parts overlap axially in a cylindrical portion. In other words, the axially overlapping portions of the pressure-side housing part and the pressure-facing housing part are smooth cylindrical. This results in a simplified production. Alternatively, the housing parts can also overlap in a conical section.

As in DE 101 09 515 B4 Also, a sealing portion of the membrane is spaced from the edge and arranged in the axially overlapping region of the housing parts. Furthermore, as in that case, a circumferential bulge may also be formed on the sealing section inside and / or outside of the membrane and / or on the pressure-side housing part and / or on the pressure-averted housing part in the region of the sealing section.

The invention also relates to an air brake system of a motor vehicle, which comprises at least one pressure-actuated diaphragm brake cylinder as described above.

list of figures

• 1 einen Betriebsbremszylinder als bevorzugte Ausführungsform eines erfindungsgemäß ausgebildeten Membran-Bremszylinders;
• 2 eine Membran des Betriebsbremszylinders von 1;
• 3 einen kombinierten Betriebsbrems- und Federspeicherbremszylinder als weitere Ausführungsform eines erfindungsgemäß ausgebildeten Membran-Bremszylinders;
• 4 einen weiteren kombinierten Betriebsbrems- und Federspeicherbremszylinder als weitere Ausführungsform eines erfindungsgemäß ausgebildeten Membran-Bremszylinders;
• 5 eine weitere Ausgestaltungsweise einer Membran für einen erfindungsgemäß ausgebildeten Membran-Bremszylinder;
• 6 ein Detail aus einer abgewandelten Ausführungsform von zwei Gehäuseteilen, wobei die Membran in der Darstellung weggelassen ist;
• 7 ein Diagramm, welches den Verlauf des Bremszylinderhubs h über dem Bremsdruck p bei einem Membran-Bremszylinder zeigt.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. In the drawing shows

• 1 a service brake cylinder as a preferred embodiment of an inventively designed diaphragm brake cylinder;
• 2 a diaphragm of the service brake cylinder of 1 ;
• 3 a combined service brake and spring brake cylinder as another embodiment of an inventively designed diaphragm brake cylinder;
• 4 a further combined service brake and spring brake cylinder as another embodiment of an inventively designed diaphragm brake cylinder;
• 5 a further embodiment of a membrane for an inventively designed diaphragm brake cylinder;
• 6 a detail of a modified embodiment of two housing parts, wherein the membrane is omitted in the illustration;
• 7 a diagram showing the course of Bremszylinderhubs h on the brake pressure p at a diaphragm brake cylinder.

Description of the embodiments

1 shows a diaphragm brake cylinder, here as a service brake cylinder 1 is trained. The diaphragm brake cylinder 1 is comprised of an air brake system of a motor vehicle not described in detail here.

This has a pressure-facing housing part 2 and a pressure-side housing part 3 on between which a membrane 4 is arranged. An edge bead 41 the membrane 4 is here conically widening outward and formed between two complementary edges 21 respectively. 31 the housing parts 2 respectively. 3 clamped at the butt joint. For this purpose, a strap surrounds 5 the edges 21 and 31 or the edge bead 41 periphery. The strap 5 is designed so that it in a known manner with conical surfaces at the edges 21 and 31 the housing parts 2 and 3 cooperates such that at an increasing tensioning of the tension band 5 a reinforcing clamping action on the edge bead 41 the membrane 4 is applied. Furthermore, the strap has 5 a castle 51 on at the ends of the tension band 5 be tightened by means of screw and nut.

The membrane 4 divides the interior of the service brake cylinder 1 in a pressure room 11 and a piston chamber 12 , In the piston chamber 12 is also a diaphragm plate 6 arranged axially displaceable, by means of a spring device 7 in the direction of the pressure-side housing part 3 is biased, as in 1 is shown.

For actuating the service brake cylinder 1 is compressed air in the pressure chamber via a valve device, not shown here 11 introduced. In other words, the pressure chamber 11 vented or vented through the valve device. About the membrane 4 then the respective present pneumatic pressure force on the diaphragm plate 6 and from this to a connected with this piston rod 9 transferred so that this against the bias of the spring device 7 and according to the increase in volume in the pressure chamber 11 away from the rear wall of the pressure-side housing part 3 emotional. The piston rod 9 then transmits the actuating force via a brake mechanism, not shown here, for example, to a disc brake or a drum brake the air brake system.

The pressure-side housing part 3 is here designed so that he is following the edge 31 axially in the direction of the pressure-averted housing part 2 extends and protrudes into this. A thus formed protuberance 32 the pressure-side housing part 3 protrudes in this case by a predetermined amount in the pressure-facing housing part 2 into it, so that the two housing parts overlap axially. Between the protuberance 32 the pressure-side housing part 3 and a cylinder area 22 the pressure-facing housing part 2 is preferably a sealing portion 42 the membrane 4 clamped so that the membrane 4 is pressed radially at this point. The sealing section 42 is spatially objectionable from the edge bead 41 before and works functionally regardless of whether the edge bead is a sufficient bias or not. Alternatively, such a sealing portion 42 also omitted, in which case the membrane 4 only in the area of the edge bead 41 is clamped.

From the membrane 4 is therefore a peripheral edge bead 41 between the edge 31 the pressure-side housing part 3 and the edge 21 the pressure-facing housing part 2 clamped, a circular central section 13 is supported on the diaphragm plate 6 and a free, bellows-shaped loop section 14 is radially between the edge bead 41 and the central section 13 arranged. Furthermore, the loop section protrudes 14 the membrane 4 in the piston chamber 12 axially into it and has a loop bottom 15 on. The loop bottom 15 thus forms the farthest into the piston chamber 12 axially protruding part of the loop portion 14 the membrane 4 ,

Furthermore protrude the extended protuberance 32 the pressure-side housing part 3 in the piston chamber 12 axially in, such that as in 1 shown, at least in the vented state of the pressure chamber 11 the protuberance 32 the loop bottom 15 of the loop section 14 the membrane 4 contacted. This becomes a vented pressure chamber 11 and therefore at the pressure-remote housing part 3 adjoining central section 13 remaining free volume of the pressure chamber 11 , the so-called Schadvolumen 17 reduced, which then a kind of "dead" volume between the pressure-side housing part 3 and the loop portion 14 the membrane 4 forms.

It is now based on 1 easy to imagine that when the pressure chamber 11 ventilated, this "dead" volume 17 must first be filled with compressed air before a compressive force can arise, which is the membrane 4 against the diaphragm plate 6 urges, causing the piston rod 9 actuated via the brake mechanism the associated brake actuator. At the same time the membrane deforms 4 especially in the area of the free loop section 14 similar to a bellows elastic.

In the 2 as a part shown membrane 4 is formed in a form that resembles a rolling membrane and differs from the pot or plate shapes for membrane. This design shows a in the pressure facing away from the housing part 2 extending bellows-shaped loop portion 14 for example, with a sealing section here 42 at the cylinder area 22 the pressure-facing housing part 2 is present, which here, for example, not to the working movements of the membrane 4 participates. This as a sealing section 42 serving area is therefore suitable as an element for static sealing of the housing parts 2 and 3 , Here, the gap width between the cylinder areas 22 and 32 chosen such that the sealing portion 42 the membrane 4 is absorbed in the course of assembly under radial compression. The size of this radial compression and the applied surface specify which pressure values in the pressure chamber 11 can be included.

According to another embodiment, not shown here, the membrane 4 no such sealing section 42 on, which at the cylinder area 22 the pressure-facing housing part 2 is applied. The membrane 4 can then during a cylinder stroke along its entire free loop section 14 move freely. The seal then takes place, for example, exclusively on the pressure of the edge bead 41 between the two edges 21 and 31 ,

3 shows a further embodiment of the diaphragm brake cylinder. This is here as a combined service brake and spring brake cylinder 100 formed, wherein a spring brake cylinder 108 only partially indicated. From the in 1 As shown, this combination cylinder differs 100 essentially in that a service brake cylinder 101 as housing parts a pressure-averted housing part 102 and a pressure-side intermediate flange 103 having. The intermediate flange 103 serves in a known manner as a connection device between the service brake cylinder 101 and the spring brake cylinder 108 ,

Analogously to the in 1 The embodiment shown here is the pressure-side intermediate flange 103 with a protuberance 132 formed in the axial direction in the pressure-facing housing part 102 protrudes. A membrane 104 , essentially identical to the membrane 4 in the first embodiment is in an analogous manner radially between the cylinder region 132 and a cylinder area 122 the pressure-facing housing part 102 trapped. Furthermore protrudes the protuberance 132 so deep in the loop section 114 the membrane 104 in that they are the loop bottom 115 of the loop section 114 contacted.

4 shows yet a modified embodiment of the diaphragm brake cylinder according to the invention. The combined service brake and spring brake cylinder shown here 200 has a service brake cylinder 201 with a pressure-averted housing part 202 and a pressure-side intermediate flange 203 on, between which the membrane 204 is arranged. Via the pressure-side intermediate flange 203 is also a spring brake cylinder 208 coupled. In contrast to the previous embodiments, no strap for fixing the elements is provided here, but a housing section 281 of the spring brake cylinder 208 engages axially over a peripheral housing section 221 the pressure-facing housing part 202 away and fixed by means of a flange the spring brake cylinder 208 , the intermediate flange 203 and the service brake cylinder 201 together.

As in 4 is shown is the edge bead 241 the membrane 204 axially between a step section 223 the pressure-facing housing part 202 and a corner area 233 of the intermediate flange 203 as a pressure-side housing part 203 trapped. Also preferred here is a sealing section 242 the membrane 204 between the cylinder areas 222 and the protuberance 232 radially clamped and has on both sides in each case a circumferential bead 243 and 244 on, which in each case a defined contact point against the cylinder areas 222 and the protuberance 232 the pressure-side housing part 203 produce.

Furthermore protrude here, too, the protuberance 232 so deep in the loop section 214 the membrane 204 in that they are the loop bottom 215 of the loop section 214 contacted.

In 5 is a modified embodiment of a membrane 304 shown. This also has the sealing section 342 Boundary beads on both sides 343 and 344 on. Unlike the in 4 However, the embodiment shown is a conical edge bead 341 formed, which is provided for example for a construction with a tension band.

In 6 is shown a detail of an embodiment in which a pressure-side intermediate flange 403 with a circumferential bead 434 is formed at the sealing point. The membrane, not shown here is through the bead 434 annular against a cylinder area 422 a pressure-facing housing part 402 pressed, so that a well-defined sealing point can be achieved. Furthermore protrude here, too, the protuberance 432 so deep into the loop portion of the membrane, not shown, that it contacts the loop bottom of the loop portion.

In addition to the embodiments shown here, the invention allows for further design approaches.

So can the housing parts 2 respectively. 3 etc. in the region of the sealing portion also be cone-shaped instead of cylindrical. The diaphragm clamped in between is then acted upon not only in the radial direction but also with a force component in the axial direction, whereby the conical design automatically adjusts the centering of the housing parts to one another. Deviating from this, it is also possible to form the sealing zone of spherical or differently shaped housing sections, or to cooperate differently shaped areas on the housing parts to reliably clamp the membrane on the sealing portion, wherein the sealing portion further spaced from the clamping point of the membrane edge at the butt joints Housing parts is.

The membrane may also be formed on one side with a circumferential bead. Furthermore, a circumferential bead can also be provided on the pressure-averted housing part. Instead of a single bead, a plurality of beads or other sealing elements such as ribs, lips, etc. may be formed on the sealing portion.

Due to the reduction of the damage volume described above 17 due to the extension of the protuberance 32 . 132 . 232 into the loop bottom 15 . 115 . 215 This results in a saving in compressed air volume, which is necessary to at the diaphragm brake cylinder 1 . 101 . 202 to carry out the actuating stroke.

An approximate determination of the percentage savings in compressed air due to the inventive design of the diaphragm brake cylinder can be made by comparing the required Betätigungshubes to achieve the respective required actuation forces for a brake design with and without Schnellanlege function "SA".

• - Anpassungsbremsung mit 1,5 bar Bremsdruck
• - Vollbremsung mit 8 bar Bremsdruck

Two typical operating conditions are considered:

• - Adaptation brake with 1.5 bar brake pressure
• - Full braking with 8 bar brake pressure

From the diagram "Brake cylinder stroke as a function of brake pressure" in accordance with 7 For example, the brake cylinder strokes h can be taken from the brake pressure p for a brake cylinder type 24 BBA of the prior art for both actuation states up to the stroke limit h _g .

The upper characteristic 18 shows the stroke-pressure curve hp of the brake cylinder without quick-start function "SA". The underlying characteristic 19 , which represents the stroke pressure curve hp of the brake cylinder with quick application function "SA", is shifted in parallel by the amount of the stroke reduction caused by the quick application (9.36 mm).

Overcoming the clearance of 1 mm in the case of the brake without quick-contact function "SA" requires, according to the lever transmission ratio of 15.6, a application stroke h ₀ of 15.6 mm. With Quick application function only results in a clearance of 0.4 mm to be overcome and thus only 6.25 mm application stroke h _{0 of} the brake cylinder.

The stroke savings of the brake cylinder is in all operating conditions 9.36 mm per actuation.

For adaptive braking with 1.5 bar, the brake without the "SA" quick-start function has a stroke of 22.5 mm.

The stroke of the brake with quick-apply function "SA" is 9.36 mm and thus 41.6% less than the stroke of the brake without quick application function "SA".

Taking into account the harmful volume contained in the brake cylinder 17 However, the percentage saving is lower.

• V in NL = Normliter
• Vges = gesamtes Volumen;
• Vh =Verdrängtes Volumen
• Vs= Schadvolumen
• Pü = Überdruck

The void volume Vs is filled with air under atmospheric pressure before the start of braking and must first reach the desired higher pressure level when venting the pressure chamber, before the pressure after a certain time is so great that a reaction can take place on the membrane. The total required air quantity Vges is roughly determined as follows: $$\text{Vges}=\text{Vh}+\left(\text{Vh}+\text{vs}\right)\times \text{pu}$$

• V in NL = standard liter
• Vges = total volume;
• Vh = displaced volume
• Vs = harmful volume
• Pü = overpressure

For example, a type 24 BBA brake cylinder considered here has an effective area Aw of 154.8 cm ² and a damaged volume Vs of 250 cm ³ .

und für eine Bremse mit Schnellanlege-Funktion „SA“ und 13,4 mm Hub: $$\text{Vh}=\mathrm{154,8}\times \mathrm{1,34}=\mathrm{203,4}{\text{ cm}}^3$$

The displacement volume Vh is thus for a brake without quick application function "SA" with 22.5 mm stroke: $$\text{Vh}=\text{Aw}\times \text{H}=154.8\times 2.25=348.3{\text{<figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$

and for a brake with quick-start function "SA" and 13.4 mm stroke: $$\text{Vh}=154.8\times 1.34=203.4{\text{<figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$

und mit Schnellanlege-Funktion „SA“: $$\text{Vges}=\mathrm{203,4}+\left(\mathrm{203,4}+250\right)\times \mathrm{1,5}=\mathrm{883,5}{\text{ cm}}^3$$

For Vges results with 1.5 bar application pressure without quick application function "SA": $$\text{Vges}=348.3+\left(348.3+250\right)\times \mathrm{1,}\text{5}=\text{1}245.75{\text{<figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$

and with quick-start function "SA": $$\text{Vges}=203.4+\left(203.4+250\right)\times 1.5=883.5{\text{<figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$

The possible reduction in compressed air is reduced by the damage volume Vs from 41% to 29%.

However, due to an inventive design of the diaphragm brake cylinder, the damage volume Vs can be reduced to about half.

An estimate of the damaged volume Vs yielded approximately 250 cm ³ dead volume for the type 24 BBA brake cylinder of the prior art considered here. Through a redesign of such a type 24 BBA brake cylinder according to the invention, the damaged volume could 17 However, be reduced to about half.

• Ohne Schnellanlege-Funktion „SA“: $$\text{Vges}=\mathrm{348,3}+\left(\mathrm{348,3}+125\right)\times \mathrm{1,}\text{5}=\text{1058}\mathrm{,25}{\text{ <figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$
  
• Mit Schnellanlege-Funktion „SA“: $$\text{Vges}=\mathrm{203,3}+\left(\mathrm{203,4}+125\right)\times \mathrm{1,}\text{5}=\mathrm{696,0}{\text{ <figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$
  

Halving the damage volume Vs from 250 cm ³ to 125 cm ³ results in the air requirement Vges as follows:

• Without quick-start function "SA": $$\text{Vges}=348.3+\left(348.3+125\right)\times \mathrm{1,}\text{5}=\text{1058}25{\text{cm}}^3$$
  
• With quick-start function "SA": $$\text{Vges}=203.3+\left(203.4+125\right)\times \mathrm{1,}\text{5}=696.0{\text{cm}}^3$$
  

When the damage volume Vs is halved, the savings in air requirement Vges achieved by the quick application function "SA" is 34.23%.

Compared with a type 24 BBA brake cylinder according to the prior art with the larger damage volume of 250 cm ³ , the saving is 0.36 NL air per actuation and brake and thus 44.13%. For a biaxial city bus this is 1,44 NL per brake application.

With full braking at 8 bar, the compressed air requirement is reduced as follows:

At a brake pressure of 8 bar, the maximum stroke of 65 mm is already reached by the brake without quick-start function "SA". The same braking force is achieved by the brake with quick-start function "SA" already at a stroke of 65 - 9.36 = 55.64 mm.

• Ohne Schnellanlege-Funktion „SA“ : 154,8 × 6,5 = 1 006,20 cm³
• und mit Schnellanlege-Funktion „SA“ : 154,8 × 5,564 = 861,30 cm³

The displacement volume Vh of the type 24 BBA brake cylinder is as follows for the above-mentioned actuating paths:

• Without quick application function "SA": 154.8 × 6.5 = 1 006.20 cm ³
• and with quick application function "SA": 154.8 × 5.564 = 861.30 cm ³

• Ohne Schnellanlege-Funktion „SA“ : $$\text{Vges}=\mathrm{1006,2}+\left(\mathrm{1006,2}+250\right)\times 8=\text{11 }\mathrm{055,6}{\text{ cm}}^3$$
  
• und mit Schnellanlege-Funktion „SA“: $$\text{Vges}=\mathrm{861,3}+\left(\mathrm{861,3}+250\right)\times 8=9\mathrm{751,7}{\text{ cm}}^3$$
  

With a harmful volume Vs in the brake cylinder of the prior art of 250 ^cm3 of air demand Vges is:

• Without quick-start function "SA": $$\text{Vges}=\mathrm{1,006.2}+\left(\mathrm{1,006.2}+250\right)\times \mathrm{8th}=\text{11}055.6{\text{cm}}^3$$
  
• and with quick-start function "SA": $$\text{Vges}=861.3+\left(861.3+250\right)\times \mathrm{8th}=9751.7{\text{cm}}^3$$
  

• Ohne Schnellanlege-Funktion „SA“: $$\text{Vges}=\mathrm{1006,2}+\left(\mathrm{1006,2}+125\right)\times 8=\text{10 }056{\text{ <figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$
  
• Mit Schnellanlege-Funktion „SA“: $$\text{Vges}=\mathrm{861,3}+\left(\mathrm{861,3}+125\right)\times 8=8752{\text{ <figure-callout id="3" label="cm" filenames="DE102016119771A1\_0017.png" state="{{state}}">cm</figure-callout>}}^3$$
  

With respect to the type 24 BBA brake cylinder halved damper volume Vs, which can be achieved by a design of a diaphragm brake cylinder according to the invention, the compressed air demand Vs results as follows:

• Without quick-start function "SA": $$\text{Vges}=\mathrm{1,006.2}+\left(\mathrm{1,006.2}+125\right)\times \mathrm{8th}=\text{10}056{\text{cm}}^3$$
  
• With quick-start function "SA": $$\text{Vges}=861.3+\left(861.3+125\right)\times \mathrm{8th}=\mathrm{8th}752{\text{cm}}^3$$
  

The savings that can be achieved in the event of emergency braking per brake and braking by the "SA" quick-start function are 1.3 NL air or 13%.

Compared with a type 24 BBA brake cylinder of the prior art with a dead space of 250 cm ³ and without quick-application function "SA" the saving is 2.3 NL or 20.8%.

It should be noted that when braking at 8 bar and without quick-start function "SA" already a reduction of the damaged volume 17 a reduction of the compressed air requirement of 9% causes.

During the adaptation braking with 1.5 bar, a 15% lower air requirement Vges can be achieved by reducing the harmful volume alone.

LIST OF REFERENCE NUMBERS

1, 101, 201

Service brake cylinder

2, 102, 202, 402

Pressure-resistant housing part

3

Pressure-side housing part

4, 104, 204, 304

membrane

5

strap

6

diaphragm plate

7

spring means

9

piston rod

11

pressure chamber

12

piston chamber

13, 113, 213

Central section

14, 114, 214

loop portion

15, 115, 215

loop ground

17

Schad volume

18

curve

19

curve

21

edge

22, 122, 222, 422

cylinder area

31

edge

32, 132, 232, 432

protuberance

41, 141, 241, 341

bead

42, 242, 342

sealing portion

51

lock

100, 200

Spring Brake

103, 203, 403

Pressure-side intermediate flange

108, 208

Spring brake cylinder

221

Edge-side housing section

223

step portion

233

corner

243, 244, 343, 344

bead

281

housing section

434

bead

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10109515 B4 [0005, 0011, 0018]

Claims (8)

Compressed-air actuated diaphragm brake cylinder (1; 100; 200) for motor vehicle air brake systems with a) a pressure-side housing part (3; 103; 203; 403) and a pressure-averted housing part (2; 102; 202; 402) and a membrane (4; 104; 204; 304) which divides the interior of the brake cylinder into two mutually sealed spaces (11, 12), of which one space is a pressurizable and ventable pressure space (11), b) being separated from the diaphragm (4; 204, 304) is clamped between the pressure-side housing part (3, 103, 203, 403) and the pressure-averted housing part (2, 102, 202, 402), a circular central section (13; 113, 213) is supported on a diaphragm plate (6) connected to a piston rod (9) which actuates a brake mechanism, and a free loop portion (14; 114; 214) radially between the edge portion (41; 141; 241; 341) and the central portion (41; 13), wherein c) de r loop portion (14) of the membrane (4; 104; 204; 304) projects axially into the space (12) deviating from the pressure chamber (11) and has a loop bottom (15; 115; 215), and wherein c) the pressure-averted housing part (2; 102; 202; 402) and the pressure-side housing part (3 ; 103; 203; 403) partially overlap axially in the region of the loop portion (14; 114; 214) of the membrane (4; 104; 204; 304), a protuberance (32; 132; 232; 432) of the pressure-side housing portion (32; 3; 103; 203; 403) projects axially into the space (12) deviating from the pressure chamber (11), characterized in that d) at least in the vented state of the pressure chamber (11) the protuberance (32; 132; 232; 432) of the the loop bottom (15; 115; 215) of the loop portion (14; 114; 214) of the membrane (4; 104; 204; 304) contacts. Compressed air actuated diaphragm brake cylinder after Claim 1 , characterized in that the housing parts (2, 3) in a cylindrical portion (22, 32, 122, 132, 222, 232, 422) axially overlap. Compressed air actuated diaphragm brake cylinder after Claim 1 , characterized in that the housing parts (2, 3) engage over in a conical section. Compressed-air-actuated diaphragm brake cylinder according to one of the preceding claims, characterized in that the pressure-averted housing part (2; 102; 202; 402) engages over the pressure-side housing part (3; 103; 203; 403) on the outside. Compressed-air-actuated diaphragm brake cylinder according to one of the preceding claims, characterized in that a sealing portion (42; 242; 342) of the diaphragm (4; 104; 204; 304) is spaced from the edge (41; 241; 341) and in the axially overlapping region of the diaphragm Housing parts is arranged. Compressed air actuated diaphragm brake cylinder after Claim 5 , characterized in that a circumferential bead (243, 244, 343, 344) is formed on the inside and / or outside of the membrane (204, 304) on the sealing section (242; 342). Compressed air actuated diaphragm brake cylinder after Claim 5 or 6 , characterized in that on the pressure-side housing part (403) and / or on the pressure-facing housing part in the region of the sealing portion, a circumferential bead (434) is formed. Compressed air brake system of a motor vehicle, characterized in that it comprises at least one pressure-actuated diaphragm brake cylinder according to one of the preceding claims.

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