EP2651725A1

EP2651725A1 - Pulsation damper of a vehicle braking system

Info

Publication number: EP2651725A1
Application number: EP11771181.2A
Authority: EP
Inventors: Georg Blosch; Harald Hermann
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-12-17
Filing date: 2011-10-21
Publication date: 2013-10-23
Also published as: DE102010063352B4; DE102010063352A1; CN103260970B; US20140116555A1; JP2013545663A; US8978704B2; CN103260970A; JP5723458B2; WO2012079813A1

Abstract

The invention relates to a pulsation damper (10) of a vehicle braking system, having a connection (14) for supplying and discharging fluid into a damper chamber (12), wherein said pulsation damper is characterised according to the invention in that the connection (14) has a segmented design, wherein a first segment (34) of the connection (14) forms a supply line and a second segment (36) of the connection (14) forms a discharge line and the two segments (34, 36) are delimited from each other by means of a separating wall (32).

Description

description

title

Pulsation damper of a vehicle brake system prior art

The invention relates to a pulsation damper of a vehicle brake system with a connection for supplying and discharging fluid into a damper chamber.

Pulsation dampers of the above type are used in the hydraulic system of vehicle brake systems to compensate during their operation pressure fluctuations that result in the hydraulic system. The pulsation damper usually form a structural unit which is connected to a block-shaped hydraulic unit or a hydraulic block of the vehicle brake system. The assembly is normally screwed into the hydraulic unit, wherein a connection connects a damper chamber of Pulsationsdämpfers with the hydraulic lines, which are formed in the hydraulic unit.

With the connection, a supply line for supplying fluid, in particular brake fluid, from the hydraulic system into the damper space and a discharge line for discharging the fluid from the damper space back into the hydraulic system to create.

Typically, the pulsation dampers are designed and screwed into the hydraulic unit that are provided with a single connection threaded inlet and outlet with only a single bore or the supply and the discharge are coaxially formed. In the solution, in which only a single hole is provided as supply and discharge line, the damper chamber is located only in a side path and not in the main stream. It is then not guaranteed that the damper chamber is always flowed through. Undamped pressure waves can be the result, which can lead to disturbances in the hydraulic system.

In the solution in which the supply line and the discharge line are coaxial, the supply line is located inside or in the center of the connecting thread and is surrounded radially on the outside by the discharge line. As a result, the fluid is mandatory in the damper chamber and only calmed down to be led out of this again to consumption points. The consumption points are then but via supply and discharge channels firstly centrally with the supply line and secondly to connect radially outside with the discharge line. These supply and discharge channels are expensive to produce and limit the degrees of freedom in the design of the hydraulic system within the hydraulic unit considerably.

Disclosure of the invention

According to the invention, a pulsation damper of a vehicle brake system is provided with a connection for supplying and discharging fluid into a damper space in which the connection is segmented, wherein a first segment of the connection forms a supply line and a second segment of the connection forms a discharge line and two segments are separated from each other by means of a partition wall.

With the solution according to the invention, a separation of a connection is provided in a plurality of segments extending in the axial direction, which are separated from one another in a fluid-conducting manner by a partition wall. As a result, the dividing wall separates the feed region from the discharge region at the connection in such a way that the supply and discharge passages can also be aligned very cost-effectively and easily to be radially aligned with the connection.

Supply and discharge channel can be arranged in the same direction opposite or at an angle not equal to 180 ° to each other. Accordingly, there are great freedoms in the design of the connection situation at the connection of the pulsation damper. The connection is preferably designed with a tube wall comprising the segments on the outside. The pipe wall may be formed with a tube which is inserted into the housing of the pulsation damper and / or the hydraulic unit.

Alternatively, the connection can also be formed on the outside by a part of the housing of the pulsation damper and / or the hydraulic unit. The inventive separation of the connecting lines for the pulsation damper can then be created by means of a partition, which is used as an insert in the bore then formed in the housing of Pulsationsdämpfers and / or hydraulic unit. The partition is preferably fluid-tight against the inner wall of the bore. If appropriate, however, it is also possible to accept a certain backflow of the dividing wall in this area from the feed line directly into the discharge line. However, the main flow of fluid flow should flow through the damper space to provide the desired tight damping.

The connection is also advantageously designed with more than two segments, of which at least two segments together form the supply line or the discharge line.

Such a configuration creates a lot of leeway for the arrangement of the feed channel and the Abführkanals in the hydraulic unit, because the two channels can be connected to the connection largely arbitrary. All that matters is that the two channels in the cross-sectional plane of the terminal include an angle greater than the angle covered by a single segment. This ensures that there is at least one separating wall between the feed channel and the discharge channel at the connection as the boundary wall of a segment, which then delimits the two channels against one another.

Therefore, the connection is advantageously designed tubular with a substantially circular cross section and the single segment forms a circle segment of this cross section. The insert of this type can be inserted into an easily produced bore in any desired angular position, which forms the connection region for the feed channel and the discharge channel in the hydraulic unit. The subdivision of the cross section of the terminal according to the invention is therefore carried out according to the invention in two circle segments, in particular two semicircles, when an angle-oriented

Mounting position is selected, and three or more circle segments, if the angular orientation of the installation position should be freely selectable.

The individual circle segment particularly preferably covers an angle of 45 °, so that over the circumference of the associated circular cross-section a total of eight circle segments come to lie with their circular arcs, which are separated from one another by means of said partitions. From these circle segments, those circle segments which face the feed channel then form the feed line into the damper space, while those circle segments, which face the discharge channel, return as a discharge line from the damper space into the associated hydraulic unit.

The connection according to the invention is furthermore preferably provided on one end side with a cover, with which at least one segment of the connection is covered.

The cover of this type allows the fluid to flow out or into the supply or discharge line located behind the free area of the cover. The other segments, however, are closed and therefore not accessible. As an alternative to a cover-side opening, at least one opening may also be provided on the lateral surface of the lines at the connection according to the invention with its segment-shaped lines. The closed with a lid end face is preferably that end face, which projects into the damper chamber. Furthermore, the connection is advantageously provided on a front side with a deflection.

The deflection serves for deflecting or diverting the flow of fluid at the connection from the radial direction, in particular within the hydraulic unit, in the axial direction of the connection and its lines themselves. The deflection is preferably located at that end side or that end region of the thereby obtained According to the invention preferably rod-shaped connection, which protrudes into the hydraulic aggregate.

According to the invention, the connection is preferably further tubular and on its lateral surface it has an opening, by means of which an inlet or outlet is created inside the tube form.

The opening is, as explained above, formed on the lateral surface of the housing of the pulsation damper or of the hydraulic unit or is located in a tube wall, which forms the outer boundary for the rod-shaped connection of this type. The opening is particularly advantageous for introducing or discharging fluid at the connection to different areas of the axial extent. Thus, inlets and outlets on the hydraulic unit and on the damper space can be formed at different levels in this way, which can be of great advantage with regard to the degrees of freedom in the ducting, in particular in the hydraulic unit.

In addition, the connection is preferably rod-shaped, in particular tubular, designed and at one end, it has a sealing portion for sealing against a formed in the associated hydraulic unit bottom surface of a Pulsationsdämpfer connection bore.

The sealing portion prevents fluid can still pass within the hydraulic unit from a feed or inflow to the discharge or outflow of the Pulsations- damper. The sealing portion is preferably created by means of a press fit. With such a press fit or a press fit of the edges of the segments against each other demarcating partition within a Pulsationsdämpfer connection hole is also to ensure that the rod-shaped connection in the connection bore within the hydraulic unit is stationary, in particular against rotation, held.

Finally, the connector is made of plastic, in particular injection molded. With a plastic part, in particular an injection-molded, the above-mentioned shape designs of the connection can be particularly cost-effective. tige and at the same time dimensionally accurate way to produce cost. At the same time a component is created, which can be handled easily during mounting and remains functional over the life of the Pulsationsdämpfers away.

An exemplary embodiment of the solution according to the invention will be explained in more detail below with reference to the attached schematic drawings. It shows:

1 is a sectional perspective view of a first example of a Pulsationsdämpfers with a connection for supplying and discharging fluid according to the prior art,

2 shows a longitudinal section of a second example of a pulsation damper with a connection according to the prior art,

3 shows a longitudinal section of a pulsation damping damper according to FIG. 2 installed on a hydraulic unit with a first variant of a connection according to the prior art, FIG.

4 shows a longitudinal section of a pulsation damper according to FIG. 2 installed on a hydraulic aggregate with a second variant of a connection according to the prior art, FIG.

5 shows a longitudinal section of a built-in hydraulic unit pulsation damper according to FIG. 2 with a third variant of a connection according to the prior art,

6 shows a perspective view of a pulsation damper according to FIG. 2 with an associated connection.

7 shows a longitudinal section of an exemplary embodiment of a pulsation damper installed on a hydraulic aggregate with a first variant of a connection according to the invention,

8 shows the section VIII - VIII in Fig. 7,

9 shows a longitudinal section of an exemplary embodiment of a pulsation damper installed on a hydraulic aggregate with a second variant of a pulsation damper

Connection according to the invention and

10 shows the section X - X in Fig. 9th

In Fig. 1, a pulsation damper 10 according to the prior art of a further not-illustrated vehicle brake system is shown. The pulsation damper 10 has a substantially spherical damper space 12 which can be fluidly connected by means of a nozzle-shaped connection 14 with a hydraulic unit, not shown in Fig. 1. The connection 14 serves for supplying and discharging the fluid, in the present case brake fluid, from the hydraulic unit into the damper chamber 12 and back into the hydraulic unit back there after the damping of pressure surges or pressure waves has taken place. In this case, located in the damper chamber 12, a membrane assembly 16, by means of which the actual damping takes place.

In the example of FIG. 1, according to the prior art, the connection 14 is provided with an outer tube 18 and an inner tube 20, which are arranged coaxially with one another. The outer tube 18 is provided with a portion of a housing 22 surrounding the damper space 12. Inside the tube 18 is then coaxial with the tube 20, which forms in this way an inner conduit which is surrounded by an outer conduit in the form of an annular channel between the tube 18 and tube 20.

In this way, fluid can flow from the hydraulic unit through the inner tube 20 in the damper chamber 12 and flow back through the outer tube 18 and thus formed annular channel back into the hydraulic unit.

The connection situation to be formed in the hydraulic unit for such a coaxial tube arrangement with the tubes 18 and 20 is comparatively expensive to manufacture because, in particular, the coupling points for the tubes 18 and 20 must be at different heights in their axial direction. Furthermore, an annular space must be formed around the outer end of the tube 18 in the hydraulic unit, through which the fluid flowing back from the tube 18 into the hydraulic unit is collected.

FIGS. 2 to 6 show a functionally equivalent example of a pulsation damper in which two coaxial tubes 18 and 20 are also provided as connection 14. In this example according to the prior art is located at the outer end of the inner tube 20, a collar-shaped projection 24 and an annular disc. With this approach 24, the tube 20 is in the installed state in the interior of the hydraulic unit to seal there. To the tube 20 around it is between the shoulder 24 and the end face of the tube 18, a coil spring 26 (see FIG. 6) arranged by means of which Tube 20 is urged against the hydraulic unit to seal with his neck 24 there. Three variants are shown in FIGS. 3 to 5, in which the tube 20 protrudes differently far into the damper space 12. The varying degrees of intrusion influences the damping effect within the damper space 12 for that fluid which flows through the damper space 12.

Fig. 3 shows a variant in which the tube 18 projects very far into the damper chamber 12, so that the fluid has to cover a long way, even within the damper chamber 12 and is correspondingly strongly attenuated. Fig. 5, however, shows the other extreme, in which the tube 18 already ends within the tube 20. The fluid then does not need to fully enter the damper chamber 12, but may already reverse within the tube 20. Accordingly, the damper effect is the lowest in this variant. 4 shows the variant in which the tube 20 ends at the beginning of the damper chamber 12, so that the damping effect of this variant represents a central solution.

7 and 8 show an embodiment according to the invention, in which the terminal 14 is not designed with coaxial tubes 18 and 20, but rod-shaped segmented or with a rod 28 which is designed segmented by a total of eight circular segments in its interior 30 are separated from one another by means of partitions 32. In this case, a first segment 34 of such a connection 14 forms a supply line and a second segment 36 of the connection forms a discharge line. The segments 34 and 36 of this type extend in the axial direction of the rod 28 and thus individually form the line which leads from the hydraulic unit 38 shown in FIG. 7 into the damper chamber 12 and out of it.

The dividing walls 32 at the same time separate a feed region with a feed channel 40 in the hydraulic unit 38 from a discharge region with a discharge channel 42 in that the rod 28 projects into the hydraulic aggregate 38 in an associated blind-hole-shaped connecting bore 44 with the dividing walls 32 on the outside. In this way, the feed channel 40 and the discharge channel 42 can be connected to the connecting bore 44 in the axial direction at a height substantially opposite one another, which is particularly cost-effective to produce in the production of the hydraulic unit 38. The rod 28 is designed with a tubular wall 46 surrounding the segment-shaped supply lines and discharge lines, which also projects into the connection bore 44, but does not extend to the end of the rod 28, so that the rod 28 as described above at its in the hydraulic unit 38 in the end region protruding radially outward open and is accessible to the inflow and outflow of fluid. The tube wall 46 is at the same time designed such that it projects into the housing 22 of the pulsation damper 10 according to FIG. 9 and forms a press fit radially outwardly therefrom.

In the embodiment of the invention shown in FIG. 7 and 8, the discharge channel 42 is at an angle of 90 ° to the feed channel 40 offset at the connection bore 44 fluidly coupled (see Fig. 8). As a result, of the total of eight circular segments 30 of the rod 28, basically two circular segments (segments 34) act as a supply line and two circular segments (segments 36) act as a discharge line, while the other four circular segments are not flowed through by fluid at all.

It is important in this arrangement that the angle of 90 °, which include the two channels 40 and 42, is greater than the angle of 45 ° (360 ° divided by eight circle segments), which cover the individual circle segments 30. This ensures that there is at least one separating wall 32 between the channels 40 and 42 between the feed channel 40 and the discharge channel 42 at the connection bore 44, which prevents fluid from flowing directly into the discharge channel 42 without detour through the damper chamber 12.

The rod 28 or insert may be any, i. in any rotational or angular position, be inserted into the connection bore 44.

The rod 28 according to FIGS. 7 and 8 is furthermore provided with a cover 48 at that end face with which it projects into the damper space 12. With the lid 48 seven of the eight circle segments 30 are covered, while at the same time a circle segment 30 is not covered. Through this open circular segment 30, fluid from the damper chamber 12 can enter into one of the segments 36, so that this acts as a discharge line. In contrast, in at least one of the segments 34 acting as a supply line, an opening 50 is formed axially below the cover 48 in the lateral surface or tube wall 46 of the rod 28, which is likewise fluid-conductively connected to the damper space 12. This opening 50 allows the flow of fluid into the damper chamber 12 such that the fluid must first travel a certain distance in the axial direction of the rod 28 before it can enter the discharge line again on the cover 48. Accordingly, this flowing through the damper chamber 12 fluid there lingers comparatively long and is subject to a strong damping effect.

Further, the rod 28 is provided at its front side opposite the cover 48 with a disc-shaped deflection 52. This deflection 52 serves for deflecting or diverting the flow of fluid from the feed channel 40 into the segments 34 acting as a supply line and during the return flow for deflecting from the acting as a discharge line 36 segments 36 out into the discharge channel 42. The disc-shaped deflection 52 is as Seal section while the bottom of the connection bore 44 in a fluid-tight manner, which also prevents fluid still within the hydraulic unit 38 of the Zuführbzw. Inflow could go to the discharge or outflow of the pulsation damper 10. Further, the deflector 52 prevents by a rounded transition in the inside that pressure waves within the feed channel 40 are not reflected hard, but are deflected into the damper chamber 12 to be attenuated there. Such geometry of the rod 28 is advantageously made by injection molding of plastic.

FIGS. 9 and 10 show an exemplary embodiment of a connection 14 according to the invention of a pulsation damper 10 on a hydraulic unit 38, in which no cover 48 is provided on the end of the rod 28 projecting into the damper space 12. Instead, the fluid supplied by the segments 34 flows into the damper chamber 12 only at the front end and from there immediately through the segments 36 back into the discharge channel 42. Accordingly, the residence time of the fluid in the pulsation damper 10 is comparatively short and a somewhat different result is obtained. usually slightly lower damping effect.

Claims

claims

A pulsation damper (10) of a vehicle brake system having a port (14) for supplying and discharging fluid into a damper space (12), characterized in that the port (14) is segmented, with a first segment (34) of the port (14) a feed line and a second segment (36) of the terminal (14) forms a discharge line and the two segments (34, 36) are delimited from one another by means of a dividing wall (32).

2. Pulsation damper according to claim 1,

characterized in that the connection (14) with a the segments (34, 36) outside comprehensive tube wall (46) is designed.

3. Pulsation damper according to claim 1 or 2,

characterized in that the connection (14) is designed with more than two segments (34, 36), of which at least two segments (34, 36) together form the supply line or the discharge line.

4. Pulsation damper according to one of claims 1 to 3,

characterized in that the terminal (14) is tubular in shape with a substantially circular cross section and the single segment (34, 36) forms a circular segment (30) of this cross section.

5. pulsation damper according to claim 4,

characterized in that the single circle segment (30) covers an angle of 45 °.

6. Pulsation damper according to one of claims 1 to 5,

characterized in that the connection (14) is provided on one end face with a cover (48), with which at least one segment (34) of the Terminal (14) is covered.

7. Pulsation damper according to one of claims 1 to 6,

characterized in that the connection (14) is provided on one end face with a deflection (52).

8. Pulsationsdämpfer according to any one of claims 1 to 7,

characterized in that the connection (14) is tubular and has on its lateral surface an opening (50), by means of which an inlet or outlet is provided inside the tube shape.

9. Pulsation damper according to one of claims 1 to 8,

characterized in that the connection (14) is rod-shaped and has at one end face a sealing portion for sealing against a in the associated hydraulic unit (38) formed bottom surface of a Pulsationsdämpfer connection bore (44).

10. Pulsation damper according to one of claims 1 to 9,

characterized in that the connection (14) is made of plastic, in particular injection molded.