GB2568650A

GB2568650A - Comfort damper

Info

Publication number: GB2568650A
Application number: GB1714390.0A
Authority: GB
Inventors: Boby Toghe Ion
Original assignee: Continental Automotive Systems SRL
Current assignee: Continental Automotive Systems SRL
Priority date: 2017-09-07
Filing date: 2017-09-07
Publication date: 2019-05-29
Anticipated expiration: 2037-09-07
Also published as: GB2568650B; GB201714390D0

Abstract

A pulsating/comfort damper intended to be integrated into anti-lock brake systems for motor vehicles, in particular servo-assisted anti-lock brake systems is provided. The comfort damper A is placed within a block B of valves SV, PRV connected by a hydraulic circuit though which brake fluid circulates. The comfort damper A mainly comprises: a damping membrane 1; a clinch pot 2; a counter part 3; and a pressing part 4. Damping membrane 1 is arranged transversely between the clinch pot 2 and the counter part 3, so that it defines air pockets a and constitutes a passage channel c for brake fluid. The passage c is coaxially aligned with the valves SV, PRV, such that the pulsations of the brake fluid are reduced and their further propagation in the hydraulic circuit is mitigated, while ensuring the continuity and sealing of the passage channel c.

Description

The invention refers to a comfort damper, designed to be integrated into anti-lock hydraulic brake systems, in particular servo-assisted brake systems.

In principle, such a servo-assisted brake system contains hydraulic valves arranged within a valve block, one self-priming pump per wheel circuit, as well as an enhanced master cylinder setup used to reduce the amount of pedal pressure needed for braking - among other hydraulic components connected by a hydraulic circuit. In order to damp the pulsations/shocks produced by opening/closing the valves and induced in brake fluid by the pump, there is provided also a pulsation damper, also known as comfort damper. By this arrangement, there are combined the advantages of a greater overall stability with a higher braking power, especially under emergency braking.

In the prior art configuration, for example, the valve block contains a non-return suction valve and a pressure retention valve, between which is inserted the pulsation damper. The usual pulsation damper has as components an elastic membrane, usually a high-pressure diaphragm, and a cover, usually a clinch pin. On the side facing the brake fluid, the membrane is designed as a substantially inverse cup-shaped body, with flat bottom and side walls bent upwardly, ending into a flat edge on which the cover is supported. The cover is inserted into a space between the side walls of the membrane and is joined by clinching. The cover has a cavity inside, so to provide space for the membrane extension. Thus, by extension of the membrane under the pressured brake fluid, pulsations and oscillations given in the system by opening/closing the valves are absorbed.

The disadvantage of the above-mentioned configuration is given by the fact that the efficacy of the pulsation damping depends on the distance to the pulsation sources, mainly the hydraulic valves. The longer the distance, the lower the pump performance, especially at low temperatures, which renders the comfort damper less effective.

The present invention addresses at least one above-mentioned disadvantage .

Since the available space is rather limited, there is a constant need for compacting the valve block's volume. In this respect, shortening the hydraulic circuit length between the valves and the comfort damper would be of help.

Therefore, the technical problem to be solved is to shorten the hydraulic circuit traversing the valve block between the valves and the pulsation damper, without prejudicing their main functions .

The object of the invention is to provide a compact comfort damper which involves low efforts and costs in manufacture and assembly and can be easily integrated into the valve block.

According to the invention, this obj ect is achieved by the subj ect matters of the independent claims, namely a comfort damper as well as a valve block equipped with such a comfort damper. Further advantageous embodiments are the subject matter of the dependent claims .

According to a first aspect, the invention provides a comfort damper comprising, along a damping membrane placed within the valve block connected by a hydraulic circuit through which circulates brake fluid, a clinch pot, a counter part and a pressing part, and the damping membrane is arranged transversely between the clinch pot and the counter part, so that it defines air pockets and constitutes a passage channel for the brake fluid coaxially aligned with the valves.

The air pockets ensure enough extension space for the damping membrane, as to be able to absorb any pressure peaks induced in the brake fluid by opening/closing the valves. By this arrangement, the further propagation of pulsations in the hydraulic circuit is mitigate, while ensuring the continuity and sealing of the passage channel.

According to a second aspect, the invention provides a valve block provided with a corresponding profiled bore as to be able to accommodate the mentioned comfort damper.

By this specific arrangement, the advantage is that only one working interface has to be machined, meaning reduced operations and costs.

By using the invention, the advantages are that the pump self-priming is improved, especially when low temperatures are concerned, the overall design is more compact and robust, the manufacture costs less and the assembling is simpler and more reliable .

For a better understanding of the invention and the advantages thereof, an exemplary embodiment of the invention is given, with reference to the attached figures, in which similar reference numbers designate similar parts. The figures represent:

Fig. 1 - longitudinal section through a valve block from prior art;

Fig. 2 - exploded view of a comfort damper according to the invention, seen from one side;

Fig. 3 - exploded view of the comfort damper according to the invention, seen from the other side;

Fig. 4 - longitudinal section through the comfort damper; Fig. 5 - transversal section through the comfort damper.

Fig. 1 shows a valve block B used in the prior art configuration, comprising a suction valve SV of a pump (not shown) and a pressure retention valve PRV between which there is positioned a comfort damper CD of a known design. In order to obtain this arrangement, there is a need for an additional bore in the valve block, in order to host the comfort damper, as well as a channel to link the comfort damper to the hydraulic circuit between the suction valve and the pressure retention valve. This arrangement means additional operations to be performed, with additional related costs .

In order to overcome such drawbacks, the comfort damper according to the invention comprises a damping membrane 1 disposed axially along the flow path between pressure retention valve PRV and suction valve SV of valve block B. Membrane 1 is maintained in place by an assembly comprising a clinch pot 2, a counter part 3 and a pressing part 4.

Clinch pot 2 is hollowed inside and forms a convex cavity, while counter part 3 opposes a concave cavity, such as the two cavities put together define an air chamber. On the outer circumference of clinch pot 2 are symmetrically cut two planar lateral walls 200, with undercuts 21 at 90°. Planar lateral walls 200 are semi circularly cut and have rounded edges. At each corner formed at the intersection of the outer circular surface with the correspondent planar lateral wall 200 there is a recess g.

Similarly, the counter piece 3 has two planar lateral walls 300, with rounded edges and semicircularly cut, and there is a pin 31 in each corner. In this way, by placing damping membrane 1 between the rounded edges of the clinch pot 2 and of the counter piece 3, two air pockets a and a passage channel c are provided between the two valves. Thus, membrane 1 defines the channel c between the valves, and each of the two air pockets a is delimited by the outer walls of membrane 1 and the afferent cavities of parts 2 and 3 .

Membrane 1 has a generally tubular shape of constant thickness but variable transversal section, with a median portion 101 having a smaller inner diameter, and two end portions 102 having relatively larger diameters. The diameter in the median portion 101 is equal to the diameter of passage channel c connecting the valves. At the end portions 102, membrane 1 is provided with grooves 103, and the end portions 102 end with an outwardly projecting edge, namely a lip 10. Along the grooves 103, the inner diameter of membrane 1 exceeds the diameter of channel c, but not more than the size of thickness. Has been chosen this shape, since grooves 103 of end portions 102 of membrane 1 abut at both ends against the edges of clinch pot 2, as well as of counter part 3, and thus damping membrane 1 becomes a sealing gasket between the two parts . Finally, in order for membrane 1 to delimit the passage channel c between the two valves SV and PRV, clinch pot 2, counter-part 3 and pressing part 4 coaxially align membrane 1 within the flow path between the two mentioned valves.

On the other hand, since in this configuration the whole assembly of the clinch pot 2, the counter-part 3 and the pressing part 4 have to withstand the pulses and shocks induced by the pump in the hydraulic circuit and to maintain the coaxial alignment of membrane 1 within the flow path, the parts must be able to maintain their stable positions. In this respect, the pressing part 4 has a circular base 401 in the middle of which there is provided an orifice o. Base 401 is bevelled on the outer circumference. Perpendicular to base 401 are two lateral ears 402 provided each with a passage hole h, whose diameter is equal to the diameter of passage channel c. Inside, pressing part 4 is not perfectly tubular, ears 402 have flat walls 403 on the inside, such as pressing part 4 overlaps the lateral walls 300 of counter-part 3 and ensures a fix position for the counter part 3. Counter-part 3 is also provided with a protrusion 301 which enters the orifice o from base 401 of pressing part 4 as to ensure fastening on the vertical axis. By joining these two parts 3 and 4, a perfectly cylindrical outer surface of the same diameter with the base 401 is obtained, for example, so as to fit into a bore specially drilled in the valve block B to accommodate this assembly.

Mounting the comfort damper according to the invention is carried out in a few steps: first, in the special bore drilled in the valve block B, the pressing part 4 is introduced with ears 402 upwards, then is inserted the counter part 3 wih the protrusion 301 in the orifice o of base 401 of pressing part 4 and the rounded edges facing upward. Then, on the rounded edges of counter part 3, dampening membrane 1 is transversely put, coaxially aligned with passage holes h of the ears 402 . Above damping membrane 1 is placed the clinch pot 2 with the rounded edges facing grooves 103, taking care that pins 31 of clinch pot 2 enter recesses g of counter part

3. Clinch pot 2 rests with undercuts 21 on ears 402 and fixes the whole assembly by being clinched on top of it. Thus, the entire assembly remains tightly sealed and stable, while absorbing the pulsations and pressure peaks produced by opening/closing the valves .

In order to achieve the best overall results, different materials are used for different components, such as:

- free-cutting steel, for clinch pot;

- aluminum or sintered metal for molding, for counter part;

- austenitic stainless steel, for pressing part;

- rubber, for damping membrane.

While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.

List of	reference signs
1	Damping membrane
2	Clinch pot
3	Counter part
4	Pressing part
101	Median portion
102	End portion
103	Groove
104	Lip
21	Undercut
200	Planar lateral wall
31	Pin
300	Planar lateral wall
301	Protrusion
401	Base
402	Ear
403	Flat wall
B	Valve block
SV	Suction valve
PRV	Pressure retention valve
a	Air pocket
g	Recess
c	Passage channel
o	Orifice
h	Passage hole

Patent claims

1. Comfort damper (A), intended to be integrate into antilocking brake systems for motor vehicles, in particular servo-assisted brake systems, placed within a block (B) of valves (SV, PRV) connected by a hydraulic circuit through which circulates brake fluid, the damper (A) comprises a damping membrane (1), characterized by that

Claims

1. Comfort damper (A), intended to be integrate into antilocking brake systems for motor vehicles, in particular servo-assisted brake systems, placed within a block (B) of valves (SV, PRV) connected by a hydraulic circuit through which circulates brake fluid, the damper (A) comprises a damping membrane (1), characterized by that the comfort damper (A) has also as components a clinch pot (2), a counter part (3) and a pressing part (4), and the damping membrane (1) is arranged transversely between the clinch pot (2) and the counter part (3), so that it defines air pockets (a) and constitutes a passage channel (c) for the brake fluid coaxially aligned with the valves (SV, PRV), as such that the pulsations of the brake fluid are reduced and their further propagation in the hydraulic circuit is mitigate, while ensuring the continuity and sealing of the flow channel (c).

2. Comfort damper (A) according to claim 1, characterized by that the damping membrane (1) has a general tubular shape of a variable transversal section, having a median portion (101) of the same diameter as the diameter of the passage channel (c).

3. Comfort damper (A) according to claims 1 and 2, characterized by that the damping membrane (1) has end portions (102) provided with grooves (103) and ended by lips (104).

4. Comfort damper (A) according to claim 1, characterized by that the clinch pot (2) is hollowed inside, forming a convex cavity, while the counter part(3) opposes a concave cavity, such as the two cavities put face to face define an air chamber.

5. Comfort damper (A) according to claims 1 and 4, characterized by that on the outer surface of the clinch pot (2) are symmetrically provided on both sides two walls (200) with undercuts (21).

6. Comfort damper (A) according to claims 1, 4 and 5, characterized by that the lateral walls (200) are cut, and in each corner formed by intersecting the outer surface with the afferent lateral walls (200) the re is a recess (g).

7. Comfort damper (A) according to claim 5, characterized by that the lateral walls (200) has outer planar surfaces.

8. Comfort damper (A) according to claim 6, characterized by that the lateral walls (200) are semi circularly cut and have rounded edges .

9. Comfort damper (A) according to claim 1, characterized by that the counter part (3) has two lateral walls (300), and in each corner formed by intersecting the outer surface with the afferent lateral walls (300) there is a pin (31).

10. Comfort damper (A) according to claims 1, 6 and 9, characterized by that the positions of pins (31) of the corners of the clinch pot (2) correspond to the positions of the recesses (g) of the corners of the counter part (3).

11. Comfort damper (A) according to claim 9, characterized by that the lateral walls (300) have planar outer surfaces.

12. Comfort damper (A) according to claim 9, characterized by that the lateral walls (300) are semi circularly cut and have rounded edges .

13. Comfort damper (A) according to claim 9, characterized by that the counter part (3) is provided with a protrusion(301).

14. Comfort damper (A) according to claim 1, characterized by that the pressing part (4) has a base (401) in the middle of which there is an orifice(o).

15. Comfort damper (A) according to claims 1, 9, 13 and 14, characterized by that the protrusion (301) of the counter part (3) has an outer diameter which corresponds to the diameter of the orifice (o) on the base (401) .

16. Valve block (B) containing the comfort damper (A) according to claims 1 to 14, characterized by that it has a corresponding profiled bore as to be able to accommodate the comfort damper.

16. Comfort damper (A) according to claims 1, 9 and 14, characterized by that the pressing part (4) has lateral ears (402) provided each with a passage hole (h) of the same diameter as the diameter of the passage channel (c).

17. Comfort damper (A) according to claims 1, 9 and 16, characterized by that the ears (402) have internal walls (403) which overlap the outer lateral walls (300) of the counter part(3) .

18. Valve block (B) containing the comfort damper (A) according to claims 1 to 16, characterized by that it has a corresponding profiled bore as to be able to accommodate the comfort damper.

Amendments to claims have been filed as follows

07 06 18

Patent claims

1. Comfort damper (A) placed within a block of valves connected by a hydraulic circuit through which circulates brake fluid,

5 comprising a damping membrane (1), a clinch pot (2), a counter part (3) and a pressing part (4), characterized by that the damping membrane (1) has a general tubular shape of a variable transversal section and is arranged transversely between the clinch pot (2) and the counter part (3), so that it constitutes 10 a passage channel (c) for the brake fluid coaxially aligned with the valves .

2. Comfort damper (A) according to claim 1, characterized by that

15 the clinch pot (2) is hollowed inside, forming a convex cavity, while the counter part(3) opposes a concave cavity, such as the two cavities put face to face define an air chamber.

3. Comfort damper (A) according to claims 1 and 2,

20 characterized by that on the outer surface of the clinch pot (2) are symmetrically provided on both sides two lateral walls (200) with undercuts (21) .

25 4. Comfort damper (A) according to claims 1, 2 and 3, characterized by that the lateral walls (200) are cut, and in each corner formed by intersecting the outer surface with the afferent lateral walls (200) the re is a recess (g).

5. Comfort damper (A) according to claim 3, characterized by that the lateral walls (200) has outer planar surfaces.

07 06 18

6. Comfort damper (A) according to claim 4, characterized by that the lateral walls (200) are semi circularly cut and have rounded 5 edges.

7. Comfort damper (A) according to claim 1, characterized by that the counter part (3) has two lateral walls (300), and in each

10 corner formed by intersecting the outer surface with the afferent lateral walls (300) there is a pin (31).

8. Comfort damper (A) according to claims 1, 4 and 7, characterized by that

15 the positions of pins (31) of the corners of the counter part (3) correspond to the positions of the recesses (g) of the corners of the clinch pot (2) .

9. Comfort damper (A) according to claim 7,

20 characterized by that the lateral walls (300) have planar outer surfaces.

10. Comfort damper (A) according to claim 7, characterized by that

25 the lateral walls (300) are semi circularly cut and have rounded edges .

11. Comfort damper (A) according to claim 7, characterized by that

30 the counter part (3) is provided with a protrusion(301).

12. Comfort damper (A) according to claim 1, characterized by that

07 06 18 the pressing part (4) has a base (401) in the middle of which there is an orifice(o).

13. Comfort damper (A) according to claims 1, 7, 11 and 12,

5 characterized by that the protrusion (301) of the counter part (3) has an outer diameter which corresponds to the diameter of the orifice (o) on the base (401) .

10 14. Comfort damper (A) according to claims 1, 7 and 12, characterized by that the pressing part (4) has lateral ears (402) provided each with a passage hole (h) of the same diameter as the diameter of the passage channel (c).

15. Comfort damper (A) according to claims 1, 7 and 14, characterized by that the ears (402) have internal walls (403) which overlap the outer lateral walls (300) of the counter part (3) .