Storage chamber for a hydraulic brake system of a vehicle

Abstract

The invention relates to a storage chamber for a hydraulic brake system of a vehicle, the storage chamber having a storage piston which is arranged in a housing of the storage chamber in such a way that the volume of a storage volume of the storage chamber defined by the storage piston can be varied, wherein brake fluid can be transferred into the enlarged storage volume via an inflow opening formed in the housing and can be transferred out of the reduced storage volume via an outflow opening formed in the housing, and wherein the storage piston is in a throttle position at a minimum volume of the storage volume such that a hydraulic connection between the inflow opening and the outflow opening is throttled by means of the storage piston in its throttle position such that the hydraulic connection remains fluid-permeable. The invention also relates to a hydraulic brake system for a vehicle, a method for producing a storage chamber and a method for operating a hydraulic brake system installed on a vehicle.

Description

Technical Field

[0001] The invention relates to a storage chamber for a hydraulic brake system of a vehicle and a hydraulic brake system for a vehicle. In addition, the invention relates to a method for producing a storage chamber for a hydraulic brake system of a vehicle and a method for operating a hydraulic brake system installed on a vehicle. Background Art

[0002] A brake system having at least one storage chamber, in particular at least one low-pressure storage chamber, is known from the prior art. For example, DE 10 2016 208 529 A1 describes a brake system for a vehicle having two brake circuits, each of which has a low-pressure storage chamber. Summary of the invention

[0003] The present invention proposes a storage chamber for a hydraulic brake system for a vehicle according to the present invention, a hydraulic brake system for a vehicle according to the present invention, a method for manufacturing a storage chamber for a hydraulic brake system for a vehicle according to the present invention, and a method for operating a hydraulic brake system installed on a vehicle according to the present invention.

[0004] The present invention proposes a storage chamber which, due to a throttling point between its inflow hole and its outflow hole, ensures that the hydraulic connection between the inflow hole and the outflow hole can be throttled in a targeted manner by means of a storage piston of the corresponding storage chamber in its throttling position. Therefore, the transfer of brake fluid between the inflow hole and the outflow hole of the corresponding storage chamber can be reliably throttled by means of the storage piston in its throttling position. Therefore, the storage piston of the corresponding storage chamber, which is designed in its throttling position for throttling the hydraulic connection, can replace or functionally support the valve element, such as a non-return valve, which is often used on and / or in the corresponding storage chamber to control the transfer of brake fluid between the inflow hole and the outflow hole. As will be explained in more detail below, this can achieve greater design freedom in the construction of the corresponding valve element.

[0005] The throttling point realized by the invention on the storage chamber according to the invention is integrated into the piston bottom surface / piston bottom of the storage piston in terms of design technology. Therefore, it is possible to achieve targeted throttling / blocking of the brake fluid transfer between the inflow and outflow openings of the corresponding storage chamber with relatively little work and at low cost. At the same time, even when the storage piston is in its throttled position, a volume flow greater than zero still occurs through the hydraulic connection between the inflow and outflow openings of its storage chamber, so that there is no need to worry about the storage piston sticking / "hydraulic adhesion" in its throttled position. ("Volume flow" can also mean "flow rate".)

[0006] In an advantageous embodiment of the storage chamber, the hydraulic connection between the inlet opening and the outlet opening has a minimum opening cross section greater than zero, despite the storage piston being in its throttle position. It is also advantageous if the hydraulic connection between the inlet opening and the outlet opening is throttled by means of the storage piston in its throttle position such that even at a pressure difference of 1 bar between the higher pressure prevailing in the inlet opening and the lower pressure prevailing in the outlet opening, the volume flow through the hydraulic connection is greater than zero and less than or equal to 1 cubic centimeter per second.

[0007] In another advantageous embodiment of the storage chamber, a nonreturn valve is arranged in the outflow opening, which nonreturn valve is designed such that it can be switched into its open state by means of an opening pressure of at most 0.5 bar so that the brake fluid present in the storage volume of the storage chamber can be transferred out of the storage volume through the opened nonreturn valve. Conventionally, the nonreturn valve must be designed for an opening pressure of at least 1 bar in order to prevent further brake fluid from flowing through the inflow opening into the outflow opening even after the storage volume has been emptied through the outflow opening and despite the storage chamber being in its emptied state. This prerequisite is eliminated when using the present invention.

[0008] For example, the non-return valve can be designed in such a way that it can be switched into its open state by means of an opening pressure of at most 0.2 bar so that the brake fluid present in the reservoir volume of the storage chamber can be transferred out of the reservoir volume through the opened non-return valve. In particular, the non-return valve can also be designed in such a way that it can be switched into its open state by means of an opening pressure of at most 0.05 bar so that the brake fluid present in the reservoir volume of the storage chamber can be transferred out of the reservoir volume through the opened non-return valve. As explained in more detail below, such a design of the non-return valve facilitates the emptying of the reservoir volume of the storage chamber.

[0009] The non-return valve can also advantageously be a springless non-return valve which can be switched into its open state by means of an opening pressure of at most 0.05 bar in such a way that the brake fluid present in the reservoir volume of the reservoir chamber can be transferred out of the reservoir volume through the opened non-return valve. The production costs of the non-return valve can be significantly reduced by not equipping the non-return valve with at least one spring.

[0010] In another advantageous embodiment, the storage chamber is a low-pressure storage chamber. The invention can therefore be used in many ways. In particular, the invention can therefore also be used advantageously for conditioning brake fluid during regenerative operation of an electric motor used as a generator for braking the corresponding vehicle.

[0011] The advantages described above are also ensured in a hydraulic brake system for a vehicle with at least one such first storage chamber. For example, the hydraulic brake system can include at least one first wheel outlet valve connected to the inflow opening of the first storage chamber and at least one first wheel brake cylinder connected to the first wheel outlet valve. Alternatively, the hydraulic brake system can also include at least one high-pressure switching valve and / or at least one pump, wherein the at least one high-pressure switching valve and / or the at least one pump are connected to the outflow opening (18) of the first storage chamber.

[0012] The implementation of a corresponding method for producing a storage chamber for a hydraulic brake system of a vehicle also achieves the advantages mentioned above. The method for producing a storage chamber for a hydraulic brake system of a vehicle can be developed according to the above-explained embodiments of the storage chamber.

[0013] Advantages are also provided by the implementation of a method for operating a hydraulic brake system installed on a vehicle. The method comprises the following steps: checking whether a wheel lock (radblockade) of a wheel assigned to a first wheel brake cylinder is present at least taking into account a signal of a rotational speed sensor assigned to the wheel; and if the presence of a wheel lock is determined at least based on the signal of the rotational speed sensor, at least temporarily opening a first wheel outlet valve; wherein if, despite the at least temporary opening of the first wheel outlet valve, at least based on the signal of the rotational speed sensor it is determined that the wheel lock has lasted longer than a predefined waiting time, the first wheel outlet valve is only still opened in a pulsating manner with a predefined pulse rate for a predefined opening time.

[0014] As an advantageous improvement, a maximum duration for how long the first wheel outlet valve is to be opened only in a pulsating manner at a pulse rate for the opening time is also determined, at least taking into account measured or estimated values ​​for the volume flow generated by the hydraulic connection between the inlet and outlet opening when the storage piston is in its throttle position, wherein a rapid pressure build-up is carried out in the first wheel brake cylinder after the maximum duration has expired. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features and advantages of the present invention are explained below with the aid of the accompanying drawings. It is shown in the drawings:

[0016] Figure 1 A schematic diagram showing a first embodiment of the storage chamber;

[0017] Figures 2 to 9 a schematic diagram of a storage piston showing another embodiment of the storage chamber;

[0018] Fig.10 A schematic diagram showing an embodiment of a hydraulic brake system;

[0019] Fig.11 A flow chart is shown for explaining one embodiment of a method for manufacturing a storage chamber for a hydraulic brake system of a vehicle; and

[0020] Fig.12 A flow chart is shown for explaining one specific embodiment of a method for operating a hydraulic brake system installed on a vehicle. DETAILED DESCRIPTION

[0021] Figure 1 A schematic diagram of a first embodiment of the storage chamber is shown.

[0022] The storage chamber 10 described in more detail below can be used in a hydraulic brake system of a vehicle / motor vehicle. The storage chamber 10 can in particular be part of a hydraulic assembly of a hydraulic brake system. It should be explicitly pointed out that the usability of the storage chamber 10 is neither limited to a specific type of brake system nor to a specific type of vehicle / motor vehicle.

[0023] The storage chamber 10 has a storage piston 14 which is arranged in a housing 12 of the storage chamber 10 in an adjustable manner. The "housing 12" can be a hydraulic assembly housing in particular. The storage piston 14 can optionally be made of metal or plastic. Therefore, the storage piston 14 can be manufactured cost-effectively.

[0024] The storage piston 14 is arranged in the housing 12 in an adjustable manner such that the volume of the storage volume of the storage chamber 10 defined by the storage piston 14 can be varied / changed. In this way, brake fluid can be transferred / diverted into the enlarged storage volume via the inflow opening 16 formed in the housing 12 and can be transferred / diverted out of the reduced storage volume via the outflow opening 18 formed in the housing 12.

[0025] When the volume of the reservoir volume is at its minimum, the reservoir piston 14 is in the throttling position. Figure 1 , a position of the storage piston 14, which can be referred to as a throttle position, is shown in FIG. 1 , when the storage volume of the storage chamber 10 is at a minimum. Typically, the storage piston 14 is supported by means of at least one (not shown) spring in such a way that, as long as no counterforce acts on the storage piston 14, at least one spring force of the at least one spring presses / pulls the storage piston 14 into its throttle position. However, since the constructability of the storage chamber 10 does not presuppose a specific spring type for its at least one spring, a more detailed description of the at least one spring of the storage chamber 10 is omitted here.

[0026] Furthermore, the storage piston 14 and / or the housing 12 are designed in such a way that the hydraulic connection 20 between the inflow opening 16 and the outflow opening 18 is throttled by means of the storage piston 14 in its throttle position in such a way that the hydraulic connection 20 remains fluid-permeable. Thus, although the storage piston 14 is in its throttle position, the hydraulic connection 20 between the inflow opening 16 and the outflow opening 18 has a minimum opening cross section greater than zero. Accordingly, even when the storage piston 14 is in its throttle position, a volume flow greater than zero is generated through the hydraulic connection 20 between the inflow opening 16 and the outflow opening 18. Therefore, when the storage piston 14 is in its throttle position, there is no need to worry about the storage piston 14 in its throttle position sticking / “hydraulic sticking”. Therefore, when using the storage chamber 10, the common disadvantages of conventional storage chambers do not have to be tolerated.

[0027] “Hydraulic connection 20 between inlet opening 16 and outlet opening 18” can be understood, for example, as a partial volume of the reservoir volume into which inlet opening 16 and outlet opening 18 merge when separated from one another. “Throttling” of hydraulic connection 20 means that the opening cross section of hydraulic connection 20 between inlet opening 16 and outlet opening 18 is greater than the minimum opening cross section when storage piston 14 is in its throttling position when the stroke of storage piston 14 out of its throttling position is greater than zero. Correspondingly, “throttling” of hydraulic connection 20 can also mean that the volume flow through hydraulic connection 20 is lower when storage piston 14 is in its throttling position than when the stroke of storage piston 14 out of its throttling position is greater than zero.

[0028] The throttling of the hydraulic connection 20 by means of the storage piston 14 in its throttle position ensures that, when the storage volume of the storage chamber 10 is at a minimum, only a relatively small amount of brake fluid flows from the inflow opening 16 into the outflow opening 18. Likewise, when the storage volume of the storage chamber 10 is at a minimum, the “transmission” of the negative pressure present in the outflow opening 18 into the inflow opening 16 is “suppressed” by means of the storage piston 14 in its throttle position. As will be explained in greater detail below, the proposed possibility of throttling the hydraulic connection 20 by means of the storage piston 14 in its throttle position improves the interaction of the storage chamber 10 with other brake system components of a hydraulic brake system equipped with the storage chamber 10.

[0029] The hydraulic connection 20 between the inlet opening 16 and the outlet opening 18 is preferably throttled by means of the storage piston 14 in its throttle position in such a way that even at a pressure difference of 1 bar between the higher pressure prevailing in the inlet opening 16 and the lower pressure prevailing in the outlet opening 18, the volume flow through the hydraulic connection 20 is greater than zero and less than or equal to 1 cubic centimeter (cm3) per second. 3 / s or ccm / s). For example, even at a pressure difference of 1 bar between the higher pressure in the inlet opening 16 and the lower pressure in the outlet opening 18, the volume flow through the hydraulic connection 20 can be greater than zero and less than or equal to 0.5 cubic centimeters per second, in particular less than or equal to 0.2 cubic centimeters per second, in particular less than or equal to 0.1 cubic centimeters per second. Advantageous throttling of the hydraulic connection 20 is achieved, for example, in that at least a partial surface of the piston bottom surface 14a of the storage piston 14 in its throttling position is pressed against the end surface 22 formed on the housing 12 in a liquid-tight manner, although a liquid-tight and full-surface form-locking connection between the piston bottom surface 14a and the end surface 22 is prevented.

[0030] exist Figure 1 The storage chamber 10 schematically shown in FIG. 1 can also be described as follows: a throttling point for selectively throttling the hydraulic connection 20 is formed on the storage chamber 10 when the storage volume of the storage chamber 10 is at a minimum. The throttling point can be described as a throttling point "integrated into" the piston bottom surface 14a of the storage piston 14. The storage chamber 10 has a "variable throttling" that can be canceled by the storage piston 14 being moved out of its throttling position with a stroke greater than zero and can be "activated" by reducing the stroke of the storage piston 14 to zero. Therefore, starting from the stroke greater than zero of the storage piston 14 out of its throttling position, the brake fluid can be transferred between the inlet opening 16 and the outlet opening 18 without problems via the unthrottled hydraulic connection 20.

[0031] Similarly, for Figure 1For the storage chamber 10 schematically shown in FIG. 1 , it is also possible to talk about the design of the throttling gap between the piston bottom surface 14a of the storage piston 14 and the end surface 22. The design of the throttling gap does not presuppose a central design of the inlet opening 16 and / or the outlet opening 18. Even in the case of a decentralized design of the inlet opening 16 and the outlet opening 18, the throttling gap can still be designed in such a way that the hydraulic connection 20 is throttled by means of the storage piston 14 in its throttle position. Therefore, there is still a large degree of design freedom when designing the inlet opening 16 and the outlet opening 18.

[0032] Figure 1 The storage chamber 10 of the embodiment also has a non-return valve 24, which is arranged in the outflow opening 18. The non-return valve 24 is arranged in the outflow opening 18 in such a way that the blocking direction of the non-return valve 24 extends from the end 18a of the outflow opening 18, which is directed away from the storage chamber 10, to the outlet opening 18b of the outflow opening 18 over the storage volume of the storage chamber 10. Therefore, a brake fluid flow directed in the blocking direction of the non-return valve 24, that is, a brake fluid flow extending from the end 18a of the outflow opening 18 to the outlet opening 18b of the outflow opening 18, is blocked by means of the non-return valve 24. However, for a brake fluid flow directed in the opposite direction to its blocking direction, the non-return valve 24 can be switched into its open state by means of an opening pressure in such a way that the brake fluid present in the storage volume of the storage chamber 10 can be transferred out of the storage volume through the opened non-return valve 24. The “opening pressure” is understood to mean the pressure difference between a first pressure present at the outlet opening 18 b and a second pressure present at the end 18 a of the outflow opening 18 , from which the check valve 24 opens for a brake fluid flow directed opposite to its blocking direction.

[0033] The storage chamber 10 is advantageously designed for throttling the hydraulic connection 20 by means of the storage piston 14 in its throttle position, which can reduce the opening pressure of the non-return valve 24 to at most 0.5 bar, whereas conventional non-return valves are usually designed for an opening pressure of at least 1 bar. The non-return valve 24 can be transferred to its open state in particular already by means of an opening pressure of at most 0.2 bar, in particular by means of an opening pressure of at most 0.1 bar, in such a way that the brake fluid present in the storage volume of the storage chamber 10 can be transferred out of the storage volume through the open non-return valve 24. The non-return valve 24 can also be a springless non-return valve 24, which can be transferred to its open state already by means of an opening pressure of at most 0.05 bar, in such a way that the brake fluid present in the storage volume of the storage chamber 10 can be transferred out of the storage volume through the open non-return valve 24. The advantages of the non-return valve 24, which are formed for the opening pressure reduced in this way compared to the prior art, will be explained in more detail below. It should also be pointed out that it is not necessary to configure the non-return valve 24 as a ball non-return valve in order to use the non-return valve 24 for the storage chamber 10. In other words, the non-return valve 24 for the storage chamber 10 can also have a differently configured shut-off body instead of a ball.

[0034] Figures 2 to 9 Schematic diagram of a storage piston showing other embodiments of a storage chamber.

[0035] exist Figures 2 to 9 , the piston bottom surface 14a of the storage piston 14 of the corresponding storage chamber 10 is respectively shown, wherein the corresponding storage piston 14 can be arranged in the housing 12 of the corresponding storage chamber 10 in such a way that its piston bottom surface 14a points to the adjacent end surface 22 of the housing 12 when the storage piston 12 is in its throttling position. Figures 2 to 9 The lines 26 and 28 in FIG. 1 represent the confluence edges of the boreholes 16 and 18 respectively.

[0036] Preferably, the piston bottom surface 14a of the storage piston 10 is rotationally symmetrically shaped. Figure 2 In the example of , the piston bottom surface 14a is flat, having a receiving portion for the central recess 30 formed therein. Figures 3 to 5 The piston bottom surface 14a (possibly in addition to the central recess 30) has a recess 32 in the form of a pointed sector ( Figure 3 and 4 ) or a recess 34 in the form of a blunt sector ( Figure 5 ). Figure 6 and 7 The piston bottom surface 14 a has a stripe-shaped recess 36 . Figure 6 The stripe-shaped recess 36 of the piston bottom surface 14a extends centrally around the central recess 30, but the stripe-shaped recess 36 is limited to Figure 6 A specific sector of the piston bottom surface 14a. Figure 7 The piston bottom surface 14 a is divided into four quarter segments, wherein the stripe-shaped recesses 36 of each quarter segment extend parallel to one of its edges and are oriented perpendicularly to the stripe-shaped recesses 36 of two adjacent quarter segments. Figure 8 The piston bottom surface 14a has a circular recess 38, the center of which is located on the outer circular track or the inner circular track of the central recess 30 around the piston bottom surface 14a. As an alternative, Fig. 9 The piston bottom surface 14a has circular protrusions 40 with different radii.

[0037] The depressions 30 to 38 or the elevations 40 formed on the respective piston bottom surface 14a can also be referred to as waffles of the respective piston bottom surface 14a. Figures 2 to 9 As can be seen, the throttling length of the throttling gap between the piston bottom surface 14a and the end surface 22 of the storage piston 14 can be changed by means of the recesses 30 to 38 or the protrusions 40 constructed on the corresponding piston bottom surface 14a. Therefore, the adhesion / adhesion force existing between the corresponding piston bottom surface 14a and the end surface 22 when the storage piston 14 is in its throttling position can be changed by means of the recesses 30 to 38 or the protrusions 40 constructed on the corresponding piston bottom surface 14a. In particular, the adhesion / adhesion force existing between the corresponding piston bottom surface 14a and the end surface 22 when the storage piston 14 is in its throttling position can be determined in such a way that "hydraulic adhesion" of the piston bottom surface 14a of the storage piston 12 in its throttling position to the end surface 22 is prevented. Figures 2 to 9 The storage piston 14 shown in FIG. 1 can also optionally be made of metal or plastic.

[0038] With the help of Figures 1 to 9 The storage chambers 10 shown in the figure can also be low-pressure storage chambers in each case. The storage piston 14 is advantageously designed to throttle the hydraulic connection 20 when the storage piston 14 is in its throttle position, which can also be used to reduce the response pressure of the corresponding storage chamber 10. This is particularly advantageous when the corresponding storage chamber 10 is used in a hybrid vehicle.

[0039] Fig.10 A schematic diagram of an embodiment of a hydraulic brake system is shown.

[0040] exist Fig.10The hydraulic brake system schematically shown in the figure is used on and / or in a vehicle / motor vehicle. In the hydraulic assembly 50 of the hydraulic brake system, only the first brake circuit of the two brake circuits is shown by way of example, wherein the second brake circuit can be constructed like the first brake circuit or differently from the first brake circuit. It should be explicitly pointed out here that the constructability / usability of the hydraulic brake system is not limited to any specific type of brake system and is not limited to specific types of vehicles / motor vehicles.

[0041] The hydraulic assembly 50 includes at least one Figures 1 to 9 The storage chamber 10 shown here is inserted into the sketched first brake circuit. Fig.10 A second brake circuit (not shown) may also optionally be equipped with such a reservoir chamber 10. “Housing 12 of the respective reservoir chamber 10” may be a hydraulic assembly housing of hydraulic assembly 50 , in particular a hydraulic assembly housing made of aluminum.

[0042] The hydraulic assembly 50 also includes at least one wheel outlet valve 52, which is connected to the inflow opening 16 of the storage chamber 10. At least one wheel brake cylinder 54 is hydraulically connected to the storage chamber 10 via the at least one wheel outlet valve 52. Fig.10 The inflow opening 16 of the storage chamber 10 shown in the figure branches only by way of example at its end pointing away from the storage chamber 10, so that two wheel outlet valves 52 are each connected to the inflow opening 16 with a connected wheel brake cylinder 54. The hydraulic assembly 50 also has at least one high-pressure switching valve 56 and at least one pump 58 with a pump motor 60. Both the high-pressure switching valve 56 and the suction side of the pump 58 are connected to the outflow opening 18, wherein the outflow opening 18 branches at its end pointing away from the storage chamber 10.

[0043] The non-return valve 24 arranged in the outflow opening 18 is oriented such that its blocking direction points from the end of the branch of the outflow opening 18 in the direction of the outlet opening of the outflow opening 18 on the storage chamber 10. The non-return valve 24 thus ensures that even if brake fluid is pressed out of the master brake cylinder 62 by actuating the brake actuating element / brake pedal 64 connected to the master brake cylinder 62 and / or by operating the brake booster 66 connected upstream of the master brake cylinder 62, no brake fluid is displaced from the master cylinder 62 connected to the high-pressure switching valve 56 into the storage chamber 10 through the opened high-pressure switching valve 56. The non-return valve 24 thus prevents "unwanted braking into the storage chamber 10 when the high-pressure switching valve 56 is open".

[0044] Furthermore, storage chamber 10 is designed to throttle hydraulic connection 20 between inflow opening 16 and outflow opening 18 by means of its storage piston 14 in its throttle position to ensure that, even in the case of a significant negative pressure in the intake chamber of pump 58, this negative pressure is not “transferred” via outflow opening 18, storage chamber 10, inflow opening 16 and at least one open wheel outlet valve 52 into at least one connected wheel brake cylinder 54. Even if the negative pressure in the intake chamber of pump 58 is sufficient to open nonreturn valve 24, this undesirable “transfer” of negative pressure into at least one wheel brake cylinder 54 connected via its open wheel outlet valve 52 triggers only a relatively small volume flow of brake fluid due to the throttling of hydraulic connection 20 between inflow opening 16 and outflow opening 18. Thus, by means of the throttling of hydraulic connection 20 between bores 16 and 18 by reservoir piston 14 in its throttle position, it is ensured that even in such a situation only a small amount of brake fluid flows from at least one wheel brake cylinder 54 connected via its open wheel outlet valve 52 into the reservoir volume of reservoir chamber 10. Thus, in such a situation, there is no need to fear a sudden drop in the brake pressure in at least one wheel brake cylinder 54 connected via its open wheel outlet valve 52.

[0045] The non-return valve 24 can therefore be designed without problems for an opening pressure of up to 0.5 bar, in particular for an opening pressure of (approximately) 0 bar. This facilitates the emptying of the reservoir volume of the reservoir chamber 10. The reduction in the opening pressure of the non-return valve 24 accelerates, for example, the emptying of the filled reservoir chamber 10 by means of the pump 58. Furthermore, the reservoir volume of the reservoir chamber 10 can also be quietly emptied into the brake fluid reservoir 68 connected to the master brake cylinder 62 by opening the high-pressure switching valve 56 without actuating the pump motor 60. In this way, a "self-emptying" of the filled reservoir chamber 10 can also be achieved.

[0046] As an optional supplement, hydraulic assembly 50 also has a switching valve 70, at least one wheel inlet valve 72, a preliminary pressure sensor 74 and a pressure sensor 76. However, it is pointed out that the provision of hydraulic assembly 50 with these brake system components is to be explained merely as an example.

[0047] Fig.11 A flow chart is shown for explaining one specific embodiment of a method for producing a storage chamber for a hydraulic brake system of a vehicle.

[0048] In optional method step S1, the housing of the storage chamber is first formed. The housing can be formed, for example, from aluminum and / or plastic. As an alternative, the manufacturing method described here can also be implemented using an already manufactured housing of the storage chamber.

[0049] As an optional method step S2, a storage piston of the storage chamber can also be formed. The storage piston can be formed by metal and / or plastic. Advantageous forms of the storage piston have been described above. However, in order to implement the manufacturing method described here, an already manufactured storage piston can also be used.

[0050] In method step S3, the storage piston is adjustably arranged in the housing of the subsequent storage chamber such that the volume of the storage volume of the storage chamber defined by the storage piston is variable, wherein brake fluid is transferred into the enlarged storage volume through an inflow opening formed in the housing and out of the reduced storage volume through an outflow opening formed in the housing. The storage piston can be supported in the housing of the subsequent storage chamber in particular by means of at least one spring.

[0051] When implementing the production method described here, the storage piston and / or the housing are designed such that the storage piston is in the throttle position when the volume of the storage volume is at a minimum. The hydraulic connection between the inlet opening and the outlet opening is throttled by means of the storage piston in its throttle position so that the hydraulic connection remains fluid-permeable. Therefore, the storage chamber produced by means of the production method described here also has the above-mentioned advantages.

[0052] Fig.12 A flow chart is shown for explaining one specific embodiment of a method for operating a hydraulic brake system installed on a vehicle.

[0053] The method described below can be used for any hydraulic brake system including at least one first storage chamber according to the above embodiment, at least one first wheel outlet valve connected to the inflow hole of the first storage chamber, and at least one first wheel brake cylinder connected to the first wheel outlet valve. Therefore, the feasibility of the method described below is not limited to Fig.10 Hydraulic brake system.

[0054] In method step S10 , a check is performed to determine whether a wheel lock is present on the wheel associated with the first wheel brake cylinder. The possible presence of a wheel lock is checked at least taking into account the signal of a rotational speed sensor associated with the wheel. Method step S10 can be repeated as often as desired.

[0055] If at least based on the signal of the rotational speed sensor it is determined that the wheel is locked, method step S11 is performed. In method step S1, the first wheel outlet valve is at least temporarily opened, wherein if despite the at least temporary opening of the first wheel outlet valve it is determined at least based on the signal of the rotational speed sensor that the wheel has locked for longer than a predefined waiting time t detectFor a longer period of time, the first wheel outlet valve is then only opened in a pulsating manner according to a predefined pulse rate for a predefined opening time.

[0056] Method step S11 can include, for example, sub-steps S11a to S11d, wherein a series of sub-steps S11a to S11d is performed at least once. First, as sub-step S11a, the first wheel outlet valve can be fully opened in order to quickly eliminate wheel locking of the wheel associated with the first wheel brake cylinder. If during the waiting time t detect If the wheel lock is not subsequently detected to be eliminated, a rotation speed sensor failure of the rotation speed sensor associated with the wheel is suspected. detect After that, the sub-step S11a is changed to the sub-step S11b. Waiting time t detect For example, it can be in the range of 1 second to 1.5 seconds.

[0057] In substep S11b, the first wheel outlet valve is only opened in a pulsating manner according to the pulse rate for the opening time. In this way, it can be ensured that the volume flow through the hydraulic connection between the inlet and outlet opening of the first storage chamber, which is throttled due to the storage piston being in its throttle position, does not lead to a critical volume V in the first wheel brake cylinder (and possibly another wheel brake cylinder connected to the first wheel outlet valve). critical The critical volume V critical For example, it can be between 2 and 5 cubic centimeters.

[0058] Optionally, a maximum duration t for how long the first wheel outlet valve is to be opened only in a pulsating manner at the pulse rate for the opening time can be determined at least taking into account a measured value or estimated value q for the volume flow generated by the hydraulic connection between the inlet opening and the outlet opening when the storage piston is in its throttle position. S11b (i.e., how long sub-step S11b is performed at most). critical The critical volume V flowing through the hydraulic connection critical has been penetrated (sickern), the total duration t critical For example, it can be determined according to equation (Gl.1):

[0059] (Gl.1)

[0060] Maximum duration t S11b For example, it can be determined according to equation (G1.2), where the opening rate p of the first wheel outlet valve during substep S11b is open can be derived from the pulse rate and the on-time:

[0061] (Gl.2)

[0062] For example, for the open rate p open For example, a value between 5% and 15% can be used. Maximum duration t S11b It is also possible to determine it according to equation (G1.3) by also taking into account the outflow volume v from the other wheel brake cylinders into the first storage chamber in the control system. ab :

[0063] (Gl.3)

[0064] Substep S11b is carried out for at most a maximum duration t S11b Thereafter, as substep S11c, a rapid pressure buildup is carried out in the first wheel brake cylinder. This can also be referred to as "start of the pressure buildup ramp". The target value for the pressure can be set, for example, to the level of the minimum blocking pressure. The rapid pressure buildup can be achieved by opening the wheel inlet valve assigned to the first wheel brake cylinder and simultaneously closing the first wheel outlet valve. Thus, a process similar to that in conventional ABS control can be used for carrying out substep S11c.

[0065] Subsequently, as a substep S11d, the pressure in the first wheel brake cylinder is reduced again to 0 bar. Thereafter, substeps S11a to 11d can be repeated at least once until braking of the vehicle is completed as method step S12.

[0066] Optionally, after method step S12, an (optional) method step S13 can also be carried out, in which the brake lining of the first wheel brake cylinder is slightly pressed together in order to eliminate any ventilation gaps. Method step S13 can also be described as the implementation of a brake disc wiping function. If possible, the brake disc wiping function is carried out without any work by the driver, for example, using an electromechanical brake booster connected upstream of the master brake cylinder. A "brake disc wiping function" can therefore be understood as an "autonomous function".

Claims

1. A storage chamber (10) for a hydraulic brake system of a vehicle, the storage chamber having: a storage piston (14) which is adjustably arranged in a housing (12) of the storage chamber (10) such that the volume of a storage volume of the storage chamber (10) defined by the storage piston (14) can be varied, wherein brake fluid can be transferred into the enlarged storage volume via an inflow opening (16) formed in the housing (12) and can be transferred out of the reduced storage volume via an outflow opening (18) formed in the housing (12); It is characterized in that The storage piston (14) is in the throttling position when the volume of the storage volume is at a minimum so that the hydraulic connection (20) between the inlet opening (16) and the outlet opening (18) is throttled by means of the storage piston (14) in its throttling position so that the hydraulic connection (20) remains traversable by liquid, wherein the hydraulic connection (20) between the inlet opening (16) and the outlet opening (18) is throttled by means of the storage piston (14) in its throttling position so that even when the pressure difference between the higher pressure prevailing in the inlet opening (16) and the lower pressure prevailing in the outlet opening (18) is 1 bar, the volume flow through the hydraulic connection (20) is greater than zero and less than or equal to 1 cubic centimeter per second.

2. A storage chamber (10) according to claim 1, wherein the hydraulic connection (20) between the inlet opening (16) and the outlet opening (18) has a minimum opening cross section greater than zero even when the storage piston (14) is in its throttle position.

3. A storage chamber (10) for a hydraulic brake system of a vehicle, the storage chamber having: a storage piston (14) which is adjustably arranged in a housing (12) of the storage chamber (10) such that the volume of a storage volume of the storage chamber (10) defined by the storage piston (14) can be varied, wherein brake fluid can be transferred into the enlarged storage volume via an inflow opening (16) formed in the housing (12) and can be transferred out of the reduced storage volume via an outflow opening (18) formed in the housing (12); It is characterized in that The storage piston (14) is in a throttle position when the volume of the storage volume is at a minimum so that a hydraulic connection (20) between the inlet opening (16) and the outlet opening (18) is throttled by means of the storage piston (14) in its throttle position so that the hydraulic connection (20) remains fluid-permeable, wherein a non-return valve (24) is arranged in the outlet opening (18) and is designed so that it can be switched into its open state by means of an opening pressure of at most 0.5 bar so that brake fluid present in the storage volume of the storage chamber (10) can be transferred out of the storage volume through the opened non-return valve (24).

4. A storage chamber (10) according to claim 3, wherein the check valve (24) is designed in such a way that it can be switched into its open state by means of an opening pressure of at most 0.2 bar so that the brake fluid present in the storage volume of the storage chamber (10) can be transferred out of the storage volume through the open check valve (24).

5. A storage chamber (10) according to claim 4, wherein the check valve (24) is a springless check valve which can be switched into its open state by means of an opening pressure of at most 0.05 bar in such a way that the brake fluid present in the storage volume of the storage chamber (10) can be transferred out of the storage volume through the open check valve (24).

6. The storage chamber (10) according to claim 1 or 2, wherein the storage chamber (10) is a low-pressure storage chamber.

7. A hydraulic brake system for a vehicle, comprising: at least one storage chamber (10) according to any one of claims 1 to 6; at least one first wheel outlet valve (52) connected to the inflow hole (16) of the storage chamber (10); and At least one first wheel brake cylinder (54) is connected to the first wheel outlet valve (52).

8. A hydraulic braking system according to claim 7, wherein the hydraulic braking system includes at least one high-pressure switching valve (56) and / or at least one pump (58), and wherein the at least one high-pressure switching valve (56) and / or the at least one pump (58) are connected to the outlet hole (18) of the storage chamber (10).

9. A method for manufacturing a storage chamber (10) for a hydraulic brake system for a vehicle according to any one of claims 1 to 6, the method comprising the following steps: a storage piston (14) being movably arranged in a housing (12) of the storage chamber (10) such that the volume of a storage volume of the storage chamber (10) defined by the storage piston (14) can be varied, wherein brake fluid is transferred into the enlarged storage volume via an inflow opening (16) formed in the housing (12) and brake fluid is transferred out of the reduced storage volume via an outflow opening (18) formed in the housing; It is characterized in that The storage piston (14) is in the throttling position when the volume of the storage volume is at a minimum, so that the hydraulic connection (20) between the inlet opening (16) and the outlet opening (18) is throttled by the storage piston (14) in its throttling position so that the hydraulic connection (20) remains traversable by a liquid.

10. A method for operating a hydraulic brake system according to claim 7 or 8 installed on a vehicle, the method comprising the following steps: Checking whether a wheel lock (S10) of a wheel associated with the first wheel brake cylinder (54) is present at least taking into account a signal of a rotational speed sensor associated with the wheel; and If at least based on the signal of the rotation speed sensor it is determined that the wheel is locked, at least temporarily opening the first wheel outlet valve (52) (S12); in, If, despite the at least temporary opening of the first wheel outlet valve (52), at least based on the signal of the rotational speed sensor, it is determined that the wheel has been locked for longer than a predetermined waiting time (t detect ) for a long time, the first wheel outlet valve (52) is then only opened in a pulsating manner according to a predefined pulse rate for a predefined opening time.

11. The method according to claim 10, wherein a maximum duration (tmax) for how long the first wheel outlet valve (52) is to be opened only in a pulsating manner at a pulse rate for the opening time is determined at least taking into account a measured value or estimated value (q) for the volume flow occurring through the hydraulic connection (20) between the inlet opening (16) and the outlet opening (18) when the storage piston (14) is in its throttle position. S11b ), where at the maximum duration (t S11b ) is completed, a rapid pressure build-up is carried out in the first wheel brake cylinder (54).

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