WO2017046392A1

WO2017046392A1 - Brake calliper in two parts, bi-material disc brake with an electrohydraulic parking brake, and method for industrialisation and assembly

Info

Publication number: WO2017046392A1
Application number: PCT/EP2016/072067
Authority: WO
Inventors: Romain RIANDA; Lennart WITTE; Cyril Cubizolles; César GARCIA
Original assignee: Chassis Brakes International B.V.
Priority date: 2015-09-16
Filing date: 2016-09-16
Publication date: 2017-03-23
Also published as: FR3041048B1; FR3041048A1; EP3230613A1

Abstract

The invention relates to a disc brake calliper, in particular for floating installation, for an automatic parking brake having a mechanical actuator with hydraulic assistance. Said calliper includes a first and a second arm which are rigidly interconnected by an arch in order to clamp the brake disc therebetween. According to the invention, the calliper includes: a first single-part portion, referred to as an added cylinder, forming the first arm and supporting the link with the vehicle, and a second single-part portion, referred to as an added arch, forming the calliper arch and the second arm, which is assembled rigidly on said first portion by mechanical assembly means. The added cylinder is typically made of aluminium, and the added arch is typically made of cast iron. According to one specific feature, the calliper includes a recess arranged so as to form the mechanical chamber of the parking brake actuator, formed in a single piece with the added cylinder. The invention also relates to a method for industrialisation and to an assembly method, including the definition and the assembly of a plurality of models of added arches on a single added cylinder model, and vice versa.

Description

"Two-piece brake caliper, dual-disc brake with electro-hydraulic parking brake, and industrialization and assembly process"

The invention relates to a disk brake caliper, in particular for floating mounting, for an automatic park brake with a mechanical actuator with hydraulic assistance. This stirrup comprises first and second branches rigidly connected to each other by an arch to enclose the brake disc between them. According to the invention, the stirrup comprises:

a first one-piece part, referred to as an attached piece, forming the first branch and carrying the connection with the vehicle, and

a second one-piece part, said attached vault, forming the stirrup arch and the second branch, which is rigidly connected to said first part by mechanical assembly means.

The reported shaft is typically made of aluminum, and the vault is typically made of cast iron.

According to one feature, the stirrup comprises a housing arranged to produce the mechanical chamber of the parking brake actuator, made in one piece with the reported shaft.

The invention further relates to an industrialization process and a method of assembly, comprising the definition and assembly of several models of vaults reported on the same model of reported barrel, and vice versa. State of the art

Disc brakes are a type of brake widely used in road vehicles, including four-wheeled and two-wheeled vehicles, particularly automobiles and light commercial vehicles.

In a disc brake, a stirrup comprising two branches interconnected by a vault is integral in rotation with the vehicle, for example the knuckle forming the hub of the wheel. The stirrup spans a sector of a disc that is secured to the wheel, with a branch on each side of the disc. The stirrup encloses the disc between its branches via a pair of friction pads, or pads, one on each side of the disc. For braking, these pads are tightened against the disc by the action of one or more brake pistons, actuated in general by hydraulic pressure. This clamping thus creates a friction between the linings and the disk, which dissipates as heat the kinetic energy of the wheel and brakes.

The service brake function is to slow the vehicle when it is moving, if necessary until it stops. In addition to the service brake, such a disk brake can also be implemented to also fulfill a function of emergency brake and / or parking brake, also called park brake. This function is usually obtained by another actuator, and usually on the rear wheels.

Many vehicles are equipped with a more or less automated parking brake function, which is controlled by means of an electric control.

FIGURE 1a to FIGURE 1d illustrates a type of disk brake including an electro-hydraulically actuated automatic parking brake function on a floating mount brake 1. In this type of assembly only one Bl of the arms of the caliper contains a brake piston 111 which presses on one 81 of the liners, and the other branch B2 directly receives the support of the other lining 82 called exterior. The support of the piston on one of the pads thus decreases the gap available between the two branches of the caliper, acting on one side of the disc 90. To compensate for this unilateral decrease, the caliper 11 as a whole moves in translation parallel to the Al direction of movement of the piston, for example by bores 71 axis A7 which slide on columns integral with the undercarriage.

In service brake, the brake piston 111 is moved by a hydraulic pressure connected to the piston chamber by one or more hydraulic openings 18, for example for an inlet and a bleed screw.

In parking brake, the displacement of the brake piston 11 is controlled by a mechanical device mounted inside a mechanical chamber 12, which is driven by an electric motor, in the housing closed by the cover 121. required clamping force to ensure and maintain the immobilization of the vehicle over a long period, this mechanism is assisted by a second hydraulic piston mounted in a chamber 13, or "boost chamber". The latter receives, by means of hydraulic inlets 138, a hydraulic pressure controlled by an electrically controlled high-pressure hydraulic pump, for example of the order of 180 bar.

Typically, as illustrated in FIGURE 1a, the mechanical chamber 12 is traversed by screws 137 which bear on the boost chamber 13. These screws are anchored in the stirrup 11 to clamp the two chambers against it and realize the assembly.

These elements are generally made by molding. The mechanical chamber 12 and the boost chamber 13 are generally light alloy, typically based on aluminum.

As illustrated in FIGURE 1b, the stirrup itself can also be made of a more rigid metal, typically cast iron, here represented in a clearer form. This allows a smaller footprint, as well as a lower absorption of effort that is to say a better "biting" braking.

Optionally, as illustrated in FIGURE 1c, the mechanical chamber can also be integrated in the stirrup lia, which is then made of aluminum alloy.

Improvements and optimizations are constantly sought in the field, particularly in terms of weight, cost, performance, reliability, bulk, but also adaptation to dimensional constraints.

An object of the invention is to overcome the disadvantages of the state of the art and to contribute to these improvements and optimizations, and to allow greater flexibility and ease of design and manufacture. Presentation of the invention

The invention proposes a disk brake caliper for a vehicle, in particular a road vehicle, of the type comprising a first branch and a second branch connected to one another rigidly by an arch and arranged to enclose between them a sector of a brake disc between seals under the action of at least one brake piston moving in a hydraulic chamber arranged at least in the first branch, which is provided to be mounted integral in rotation of the vehicle.

This stirrup is designed to receive, in a housing arranged specifically for this purpose, an electric park brake actuator, called a "boost chamber", which performs a parking brake function by acting on the brake piston of said stirrup according to an action combining electrical and hydraulic. This actuator comprises:

on the one hand a mechanical chamber including a controlled electric drive mechanism, which is arranged to clamp said brake at least by pressing on said brake piston, and

on the other hand a support chamber including at least a second hydraulic piston adapted to receive a hydraulic pressure of a hydraulic circuit under pressure so as to generate a support concurrent clamping achieved by the mechanism of said mechanical chamber.

According to the invention, this stirrup comprises:

on the one hand a first one-piece part, called said casing, which carries out the first leg and carries one or more members intended to ensure the connection of said caliper with the vehicle, and

- On the other hand a second one-piece part, said vault reported, which carries the stirrup arch and the second branch, and is rigidly connected to said first part by mechanical assembly means.

The reported shaft typically comprises the hydraulic chamber, and carries the various members of fasteners, for example arms receiving columns in the case of a sliding or floating mounting.

The vault thus includes the opposite part of the stirrup, also called the nose in the case of a sliding or floating assembly, which is supported on the outer lining.

As can be understood, the vault can thus be manufactured according to a different process of the reported barrel, and / or in a different material.

This independent vault allows a modularity in the architecture of the brake, in size or material or both according to the needs, for example by providing several types of vault for the same base Caliper. Such modularity allows for example a greater flexibility to adapt to the constraints of different car manufacturers, for example for the size between rim and caliper.

The result is greater flexibility, simplicity and economy in inventory design and management.

By separately separating these two parts of the stirrup, in spite of the disadvantages generated by their assembly, the invention thus makes it possible to obtain different advantages for each part, optimized according to the needs of each part and of the assembly sought, and combine these benefits in one caliper.

Preferably, the vault is made of a material different from that of the reported barrel, in particular of a better rigidity. The stirrup can thus enjoy the advantages of a material for the vault, while keeping the advantages of the other material for the barrel and its hydraulic mechanism.

According to one feature, the casing is formed by a molded part made of an alloy mainly based on aluminum, and the added vault is formed by a part (preferably molded) of cast iron or an alloy predominantly based on iron.

The reported shaft can thus benefit from the specific advantages of a lighter alloy, in particular the aluminum alloy: in particular the lightness, made possible by mechanical stresses less important than in the vault; and ease and precision of molding, resulting in less machining retouches and easier to achieve.

The vault can thus take advantage of the specific advantages of a more rigid material, in particular cast iron: for example a lower cost and / or a smaller footprint for the same resistance. It also allows a better stiffness of the stirrup, therefore a reduced absorption, that is to say a better "mordant" braking obtained.

Compared to a one-piece bracket, the separation between the reported shaft and the vault is provided in different positions, more or less close to the shaft. Preferably, this separation is provided at the birth of the vault, and the vault itself is entirely realized by the second part. It is thus possible to realize a larger assembly surface, and to maximize the length of the vault that can be made of a different material.

The invention is applicable to a single piston caliper, as described in more detail below.

It is also applicable to a stirrup comprising in which the barrel includes at least two brake pistons arranged and actuated in parallel, for which the advantages are even more pronounced, because of the increased complexity of the shapes to be made in the caliper barrel .

The invention is particularly, but not necessarily, applicable to sliding or floating type mounting. In other types of mounting, for example with one or more pistons on the outside, the nose of the vault also includes a hydraulic chamber. In these other types of assembly, the composite appearance and the modularity that it provides confer the same types of advantages as for the floating assembly, at least for the parts located on the side of the caliper drum.

According to a first embodiment, the mechanical chamber and the boost chamber form two distinct subassemblies rigidly assembled on the shaft reported by mechanical assembly means.

According to a second embodiment, the mechanical chamber and the shaft are formed as a one-piece element, on which the boost chamber is rigidly connected by mechanical assembly means.

In the state of the art, the fact of integrating the mechanical chamber to the stirrup made it necessary to make it aluminum alloy. It was therefore impossible or even more difficult and expensive to make a cast iron caliper, for example because of the additional complexity of the forms provided by the mechanical chamber.

By separating the stirrup in two parts, the invention thus makes it possible to obtain the advantages of cast iron for the vault, while at the same time achieving a single assembly incorporating a stirrup shaft and a mechanical chamber, since this can be made of alloy aluminum with far fewer disadvantages and limitations. The realization of a stirrup vault and reported barrel thus provides a particularly advantageous advantage in the case of this type of parking brake. It makes it possible to adopt this type of parking brake in many configurations whose technical constraints did not allow it until now, for example for large efforts or particularly intensive uses, especially in a small footprint.

This integration of the mechanical chamber, while enjoying the advantages of cast iron for the vault, then allows for example:

- No longer having to perform a seal (air) between the caliper shaft and the mechanical chamber, and / or

better alignment of their different mechanisms, and / or

a decrease in the length and greater ease and flexibility of implantation of the anchoring screws of the boost chamber.

Optionally, the invention also proposes to integrate the boost chamber stirrup barrel in addition to the mechanical chamber, with the same type of benefits.

According to yet another aspect, the invention proposes:

a stirrup element arranged to make a second part, or vault attached, of a stirrup as described here, and / or

a stirrup element arranged to make a first part, or be reported, of a stirrup as described here.

According to another aspect of the invention, there is provided a disc brake including at least one stirrup as disclosed herein.

According to another aspect, the invention provides a vehicle or subassembly of vehicle comprising at least one brake or stirrup as described herein.

The invention also allows improvements in the industrialization process and manufacturing of such a brake or such a vehicle or subassembly of vehicle. Thus, according to another aspect of the invention, there is provided an industrialization process which comprises the following steps:

provide a reported barrel of an existing type intended to achieve a first type of brake or vehicle determined, typically by assembly with a first type of vault reported; and

determination or selection, according to a second type of brake or vehicle to be assembled, a second type of reported vault arranged to be assembled on said shaft and thus achieve said second type of brake or vehicle to assemble.

According to another aspect of the invention, an assembly method is proposed which comprises the following steps:

producing or providing an insert shaft comprising positioning and fixing means for receiving indifferently several types of reported vault;

choose a vault, in a choice of several types of vaults reported different sizes, depending on a type of brake or vehicle to assemble, for example according to size criteria or a brake version or vehicle to be produced; and

- Assembling said vault attached to said reported shaft.

Various embodiments of the invention are provided, integrating, according to all of their possible combinations, the various optional features set forth herein.

List of Figures

Other features and advantages of the invention will emerge from the detailed description of an embodiment which is in no way limitative, and the appended drawings in which:

FIG. 1 illustrates a state of the art of a floating-mount disk brake equipped with an electro-hydraulically actuated automatic parking brake device, with: o in FIGURE la, an explosion of such a brake in an all aluminum version, with separate mechanical chamber and boost chamber assembled on the caliper, o in FIGURE lb, an explosion of such a brake in a version with caliper cast,

in FIGURE 1a, an explosion of such a brake in a version with stirrup and chamber forming an aluminum one-piece element, and

o in FIGURE 1d, a perspective view of such a brake once assembled;

- FIGURE 2 is a top view on the scale of an exploded brake, in a first embodiment of the invention, with cast iron assembled vault on an aluminum caliper shaft, with chamber mechanical and boost chamber manufactured separately; FIG. 3 is a top view on the scale of an exploded portion of a brake, in a second embodiment of the invention, with an attached cast iron vault on an aluminum stirrup shaft, including one-piece mechanical chamber;

FIGURE 4 is a scale view of the brake of FIGURE 2, in section along the axis of the brake piston; and

FIGURE 5 is a perspective view at the scale of the brake of FIGURE 2, before assembly of the attached vault.

Description of an exemplary embodiment

As is understood, the invention makes it possible to associate a bi-material stirrup with an "APB-H" module, that is to say, enabling the automated activation of parking braking by electro-hydraulic operation.

The composite architecture within the caliper, implemented in a two-material cast-aluminum way, provides advantages in terms of mass and stiffness, which can be adjusted differently and more widely compared to the state of the technical.

By associating this composite stirrup with a module of the APB-H type, one obtains the same advantages for the service braking while combining them with other advantages related to an optimization of various

FIRE I LLE OF REM PLACEM ENT (RULE 26) rooms and stirrup parts, ie the boost chamber, the mechanical chamber, the shaft reported and the vault reported.

As illustrated in FIGURE 2 to FIGURE 5, this stirrup 20, 20b is composed of a cast iron vault 29 (shown in clear material) and a shaft 21, 21b made of aluminum alloy (shown in gray in the figures). . The two parts of the stirrup are made integral by two screws 27 whose heads are supported in housings 217 formed in the shaft 21, 21b and whose thread is held in the arch 29. First exemplary embodiment

In the first exemplary embodiment of the invention, illustrated in FIGURE 2, FIGURE 4 and FIGURE 5, the APB-H module is composed of two independent aluminum alloy chambers, the mechanical chamber 22 and the booster chamber. 23. These two chambers are clamped together and against the shaft 21 reported by three screws 237, based on the boost chamber and whose threading is made in the shaft 21 of the stirrup 20.

As illustrated in FIG. 4, the mechanical chamber 22 encloses in its interior space 210 a pinion 221, actuated by an electric motor enclosed by the cover 221. This pinion 221 is provided with an internal thread which drives in translation, in the axis brake piston 211, a screw 222 held in a flange 229. This screw 222 has a control end 224 which sealingly enters the hydraulic chamber 210 of the brake piston 211. It is linked in translation to a control end 212 of the brake piston 211. This mechanism thus forms an electromechanical actuator which provides the motion control to the tightening and loosening, by pushing and pulling the brake piston 211 by its control end 212.

This electromechanical actuator is assisted in its clamping force (to the right of the figure), for the required clamping force, by a second hydraulic piston 231 housed in the internal space 230 a hydraulic chamber inside the chamber 23. This second piston 231 receives a high hydraulic pressure (about 180 bar) by a hydraulic circuit 238 assistance. This assistance pressure is provided for example by the ESP pump, or by an electric actuator booster "i-booster" realizing besides the main service braking assistance, under the effect of this pressure, this second hydraulic piston 231 presses on one end 223 of the screw 222 of the mechanical chamber 22.

Second exemplary embodiment

In the second exemplary embodiment of the invention, illustrated in FIGURE 3, the stirrup shaft 21b integrates the mechanical chamber in a one-piece fashion of aluminum alloy. It thus allows additional advantages specific to the integration without sacrificing the advantages that a vault brings to another material, here cast iron.

In this embodiment, compared with a brake with APB-H according to the state of the art with cast iron caliper as shown in FIGURE 1b, which can not integrate the mechanical chamber, the brake according to the invention retains the advantages of Cast iron caliper while providing the following benefits:

Total mass of the reduced brake,

Optimization of the total length of the brake, since the caliper shaft and the mechanical chamber are fused in one piece 21b,

Flexibility over the length and positioning of the screws 237b fixing the boost chamber 23 on the part 21b thus fused,

Elimination of an airtight zone E12 between the mechanical chamber and the stirrup shaft.

Compared to a brake with APB-H according to the state of the art with aluminum stirrup, incorporating (FIGURE 1a) or not (FIGURE 1a) the mechanical chamber, this brake according to the invention allows the advantages of the cast iron caliper and thus brings the following advantages:

Possibility of obtaining a higher stiffness of the brake and therefore a reduced absorption,

- Possibility of refocusing the center of gravity of the brake towards the caps of small columns.

Compatibility with small dimensions requested by the manufacturer between the rim of the wheel and the vault of the caliper.

Reduced thermal and electrical conductivity, and Cost more economical than APB-H with all-aluminum bracket.

Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

Nomenclature

Prior art

1 brake APB-H in 3 parts

11 aluminum stirrup

12 mechanical chamber

121 mechanical chamber motor cover

13 boost room

137 boost chamber screws

138 arrival of boost circuit

18 service brake system arrival

11b cast iron caliper

the brake APB-H in 2 parts

11c aluminum caliper integrating the mechanical chamber

Invention

2 brake APB-H in 3 parts

20 cast-aluminum composite calliper

21 aluminum reported

2b brake APB-H in 4 parts

20b cast-aluminum composite calliper, with integrated mechanical chamber

210 hydraulic piston brake chamber

211 brake piston

212 control end of the brake piston

21b was reported with integrated mechanical chamber

22 mechanical chamber

221 mechanical chamber motor cover

222 mechanical chamber actuating screws

223 assist end of the actuating screw

224 control end of the actuating screw 229 flange of actuating screws

23 boost room

230 room hydraulic boost chamber

231 second hydraulic piston - assist piston 237, 237b boost chamber screw

238 arrival of boost circuit

27 caliper assembly screws

271 housing of the caliper assembly screws

28 service brake circuit arrival

29 cast iron vault

71 bores and arms of balusters

81 interior trim

82 exterior trim

90 brake disc

Al piston pin brake

A7 axes of balusters

Bl first branch

B2 second branch

E12 sealing between barrel and mechanical chamber

Claims

A disc brake caliper (20, 20b) for a vehicle, in particular a road vehicle, comprising a first limb (Bl) and a second limb (B2) interconnected rigidly by an arch and arranged to enclose a sector of a brake disk (90) between linings (81, 82) under the action of at least one brake piston (211) moving in a hydraulic chamber (210) provided in at least the first limb, which is provided for be mounted in rotation with the vehicle,

said stirrup comprising at least one housing arranged to receive an electrically operated parking brake actuator which is arranged to perform a parking brake function by acting on the brake piston (211) of said stirrup, which actuator comprises:

on the one hand a mechanical chamber (22) including a mechanism (221, 222,) with a controlled electric drive, which is arranged to clamp said brake at least by pressing (212) on said brake piston (211), and

on the other hand a chamber (23) including at least a second hydraulic piston (231) adapted to receive a hydraulic pressure of a hydraulic circuit (238) under pressure so as to generate a support (223) contributing to the clamping performed by the mechanism of said mechanical chamber (22).

said stirrup being characterized in that it comprises:

on the one hand a first one-piece part (21), said attached barrel, which carries the first limb (Bl), carries said at least one actuator housing, and carries one or more members (71) provided to ensure the connection of said stirrup with the vehicle, and

on the other hand a second one-piece part (29), said added vault, which forms the stirrup arch and the second branch (B2), and is rigidly connected to said first part (21) by mechanical assembly means ( 27).

2. Caliper (20, 20b) according to the preceding claim, characterized in that that the insert (21) is formed by a molded part made of an alloy mainly based on aluminum, and the added vault (29) is formed by a molded part made of cast iron or an alloy mainly made of iron .

3. Caliper according to any one of the preceding claims, characterized in that the barrel includes at least two brake pistons arranged and actuated in parallel.

4. Caliper according to any one of the preceding claims, characterized in that the mechanical chamber (22) and the boost chamber (23) form two separate subassemblies rigidly assembled on the shaft (21) by means of assembly mechanical (237).

5. A stirrup according to any one of the preceding claims, characterized in that the mechanical chamber and the shaft are formed as a one-piece element (21b), on which the boost chamber (23) is rigidly assembled by mechanical assembly means (237b).

6. stirrup element (29) arranged to produce a second part, or vault reported, of a stirrup (20, 20b) according to any one of the preceding claims.

7. stirrup element (21, 21b) arranged to produce a first part, or be reported, of a stirrup (20b) according to any one of claims 1 to 5.

8. Vehicle or subassembly of vehicle comprising at least one stirrup (20, 20b) according to any one of claims 1 to 5.

9. A process for industrialising a disk brake (2, 2b) comprising a caliper according to any one of claims 1 to 5 or a vehicle or vehicle subassembly according to claim 8, characterized in that includes the following steps: providing an insert (21, 21b) of an existing type intended to provide a first type of brake or a specific vehicle;

determination or selection, according to a second type of brake or vehicle to be assembled, of a second type of vault (29) arranged to be assembled on said attached shaft and thus to make said second type of brake or vehicle to to assemble.

10. A method of assembling a disk brake (2, 2b) comprising a caliper according to any one of claims 1 to 5 or a vehicle or subassembly of a vehicle according to claim 8, characterized in that it includes the following steps:

producing or providing an insert (21, 21b) comprising positioning and fixing means for receiving indifferently several types of vault reported;

choosing a vault (29), in a choice of several types of vaults reported different sizes, depending on a type of brake or vehicle to assemble;

assembling said vault attached to said barrel reported.