WO2019123206A1 - Front-rear combined braking system of a motorcycle and related motorcycle - Google Patents

Abstract

A front-rear combined braking system of motorcycle (100), allows a considerable design flexibility and comprises: a first member for operating the front brake (107) and a second member (1) for operating the rear brake both movable between a resting and an operating position; a hydraulic actuator (108) of the front brake (107), hydraulically operated by means of said first operating member; a mechanical actuator of the rear brake (109); a distribution device (3) inducing the actuation of said hydraulic actuator (108) in response to the actuation of the second operating member (1), which includes a floating piston (21) inserted in a corresponding hydraulic chamber (20), the floating piston (21) being apt to exert a pressure in a transmission fluid in said hydraulic chamber (20) due to the effect of the actuation of a hinged lever (12) connected to said second operating member (1) and to said mechanical actuator, wherein the hinged lever (12) is configured to provide a first mechanical control to said rear brake (109) and to produce a mechanical push apt to actuate said distribution device (3) and then the hydraulic actuator (108) of the front brake (107) when said second operating member (1) is actuated, and wherein the hinged lever (12), the second operating member (1) and the mechanical actuator of the rear brake (109) are connected by respective tie rods (6, 10, 15) to the ends (9, 11) and to an intermediate joint (8) of a distribution lever (7), respectively.

Description

Front-rear combined braking system of a motorcycle and related motorcycle

Description

The present invention relates to a front-rear combined braking system of a motorcycle, in particular a motorcycle and a related system providing a hydraulically operated front brake, in particular but not exclusively a disc brake, and a mechanically operated rear brake, in particular but not exclusively a drum brake.

Under hydraulic actuation an actuation is meant which provides to transfer an actuation pressure through an incompressible fluid in a transmission duct, with a hydraulic piston determining an actuation pressure in a cylinder, pressure which is transmitted as far as an actuator which controls a mechanical braking member, for example the grippers of a disc brake. This scheme is usually used for the front brake.

Under mechanical actuation an actuation is meant which provides an actuation cable which is pulled by a control member, typically a lever on the handlebar or a pedal on the vehicle footboard, so as to transmit with this traction an actuation force as far as a braking mechanical member, acting opposite to a spring return device. This scheme is usually used for the rear brake.

Under combined braking system a system is meant which provides the separate actuation of each brake, but wherein the actuation of the rear brake, in particular with a strong sinking of the control member, even determines the actuation of the front brake, with a delay with respect to the rear brake and with a lower braking force, to avoid that the vehicle stops dead or that the front rear locks, thus causing a strong discomfort and a potential serious danger for the occupants of the motorcycle.

Besides, should a sufficient force not be transferred on the wheel, the braking action alone exerted on the rear wheel could not be sufficient to stop the vehicle within the distance expected by the driver.

Therefore, the combined system has the purpose of balancing the braking loads between front wheel and rear wheel so that the vehicle, even during an abrupt brake, remains stable to a certain extent, by guaranteeing at the same time a brake with the stopping distance as small as possible.

Various solutions for implementing a combined system as above described are known.

The International patent application N. WO 2016/156,140 A1 describes a system for activating a combined braking system wherein the control cable coating carries out an active role on a distribution member of the braking force, in a way which cannot be repeated easily over time and which is difficult to implemented .

International patent application No. WO 2015/181,798 A1 describes another system for activating a combined system wherein a distribution member includes a control through cable, suitable for high power motorcycles but which can be scaled with difficulty during planning.

European patent application No. EP 2,607,194 A describes another activation integrated system which uses a hydraulic distribution device with a hydraulic double room.

Italian patent No. IT 1,395,261 describes a synchronization device for braking systems with a hydraulic distribution device activated by means of levers. A similar system is described even by Italian patent No. IT 1,392,745 and by Japanese patent No. JP 4532753. These implementations suffer too from poor precision in the distribution of the forces and adapt with difficulties to design variants in the braking system as a whole.

International patent application No. WO 2017/168,231 A describes a combined brake having a hydraulic front brake, with a valve for controlling the combined brake, and a mechanical rear brake, wherein the control lever has a restriction in the rotation angle which does not allow to differentiate the time for actuating the two brakes.

A similar problem is involved in the braking systems described in European patent applications No. EP 2,682334 A2 and No. EP 0, 995, 653 A1.

The technical problem underlying the present invention is to provide a combined braking system allowing to obviate the drawback mentioned with reference to the known art.

Such problem is solved by a system as specified above and as defined by the enclosed claim 1.

The main advantage of the integrated braking system according to the present invention lies in the fact of allowing a greater design flexibility in adapting to the brakes used in the vehicle.

The present invention will be described hereinafter according to some examples thereof of preferred embodiment, provided by way of example and not for limitative purposes with reference to the enclosed drawings wherein:

* figure 1 shows a side view of a motorcycle which uses a braking system used according to the invention;

* figure 2 shows a partial perspective view of the motorcycle of figure 1, that is the car body thereof, which includes an integrated braking system according to the present invention;

* figure 3 shows a view in partial section of a detail of the car body of figure 2 and of a portion of a first example of integrated braking system assembled in the motorcycle of the preceding figures;

* figure 4 shows a section view of the detail of braking system of figure 3;

* figure 5 shows an enlarged view of the detail of integrated system of figure 3;

* figure 6 shows a top view of the car body of figure 2 and a second example of integrated braking system assembled in the motorcycle of figures 1 and 2;

* figure 7 shows a side view and in partial section of the car body of figure 2, illustrating the integrated braking system of figure 6;

* figure 8 shows a side view of a detail of a portion of the assembled integrated braking system of figure 6; and

* figure 9 shows a plan view of the portion of integrated braking system of figure 8;

* figure 10 shows a side raised view of a distribution device used in the embodiment examples of integrated braking system of the examples illustrated in figures 3 to 9;

* figure 11 shows a plan view of the distribution device of figure 10;

* figure 12 shows a section view of the device of figure 10, taken according to a plane A-A in figure 10;

* figure 13 shows a section view of the device of figure 10, taken according to a plane D-D in figure 12; and

* figures 14 and 15 show respective side raised views of the device of figure 10 in a first and in a second operating configuration .

By referring to figures 1 and 2, a motorcycle, and in particular a scooter, is designated as a whole with 100. The invention relates to the field of the saddle vehicles in general, with particular reference to the scooter having a propulsion unit arranged below a saddle 101, inside a chassis 102 which herein is represented laterally, extending from a front wheel 103, driven by a handlebar 104 to a driving rear wheel 105.

The steering front wheel 103 is connected to the suspended mass of the vehicle by means of a shock-absorbing suspension 106, associated to the hub of the wheel, thereat a front brake 107 of the disc type is provided, that is in more general terms a hydraulic actuation brake as defined previously, controlled by a suitable gripper 108 which constitutes, in this example, a hydraulic actuator of the front brake 107.

The driving rear wheel 105 instead comprises a rear brake 109, for example of the drum type, that is in more general terms a mechanical brake or actuated mechanically as defined previously, in the present embodiment example constituted by a rotating drum integral with the wheel, wherein brake-shoes or jaws are provided, which in the present example constitute a mechanical actuator of the rear brake 109, made of friction material apt to exert a force on the drum, actuated by means of the traction of a cable the terminal thereof provides a spring which guarantees the elastic return of the cable in the starting position thereof.

The hydraulic brake is typically controlled by a manually- actuated brake lever, conventionally arranged on the handlebar 104, connected to an actuating hydraulic system.

The manually actuated actuation lever then constitutes a first member for operating the front brake 107, which allows the hydraulic control of the hydraulic actuator 108, that is the gripper of the disc brake, by typically opening a hydraulic circuit in pressure, wherein a pressure actuating the gripper propagates.

According to the first one of the herein described examples, of the front-rear combined braking system, it further comprises a second member for operating the rear brake 109 which, in the present example, is implemented by a pedal 1 arranged at the pedal board 110 which, in the motorcycle 100, separates the front portion with the handlebar 104 from the rear portion with the saddle 101.

The car body 102 further has a case 111 arranged in the front portion of the motorcycle 100, in particular on the face of the front shield faced towards the driver, and then faced in the direction of the pedal board 110 and accessible through a door, further provided with a bottom 112, corresponding to said face of the front shield.

At the bottom 112 of the case 111, the integrated braking system comprises a supporting plate 2 thereto a distribution device 3 is associated having a substantially cylindrical and hollow body, with a bored through-hole developing according to its longitudinal axis, so as to define a hydraulic chamber 20 and which includes a floating piston 21 apt to exert a pressure in a transmission fluid included in said hydraulic chamber 20.

As it will result evident from the following description, the distribution device 3 is arranged to induce the actuation of the hydraulic actuator 108 of the front brake 107 in response to the actuation of the second operating member, that is pedal 1.

From a more general point of view, the distribution device 3 is placed at the steering column of the scooter 100, that is in its front portion which corresponds to the handlebar 104 and to the front wheel 103.

To this purpose, the distribution device 3, at an intermediate portion thereof, comprises an inlet section 5 of the hydraulic chamber 20, obtained through the thickness of the cylindrical body, connected, by means of a not represented tubular duct of hydraulic transmission, to a hydraulic pump, not represented too and of substantially conventional type, which is capable of keeping a fluid, included inside the hydraulic chamber 20 in pressure.

Moreover, the distribution device 3, placed side by side of said inlet section 5, comprises an outlet section 4 of the hydraulic chamber 20, connected hydraulically through a not represented tubular duct of hydraulic transmission, which in turn is connected to the first actuation member, that is the grippers 108 of the front disc brake.

Therefore, the front brake 107 is sensible to the pressure which is established in the hydraulic chamber 20, and which is transmitted from said transmission duct through the outlet section 4.

The above-mentioned floating piston 21 is movable from a position wherein it locks the outlet section 4 to an activation position of the front brake wherein a hydraulic communication is implemented between the inlet section 5 and the outlet section 4 (figure 12) through said hydraulic chamber 20.

The distribution device 3 comprises then a stem 50 which crosses longitudinally the hole in the cylindrical body of the device 3, whereon said floating piston 21 is formed as one piece. The stem 50 ends with a shutter 51 which closes the hole which constitutes the cylindrical chamber 20. Around the stem 50 a helical spring 22 is arranged which is compressed between the floating piston 21 and a stopping member 53 projecting inside the hydraulic chamber 20.

Opposite to the shutter 51, the stem 50 comprises an actuation end 54 extending by projecting externally to the cylindrical body of the distribution device 3.

On the actuation end a pressing member 13 is rested by compression: it is arranged at the free end (figures 10 to 12) or in an intermediate portion (figures 5 and 6) of a hinged lever 12. It has a hinged end having a lever fulcrum 16, in a fixed position with respect to the distribution device since for example it is obtained in the supporting plate 2 of the device 3 (figures 5 and 6) or in a rigid arm 55 projecting from the cylindrical body of the device 3 ( figures 10 to 12 ) .

Moreover, advantageously a spring-elastic member acts on the hinged lever 12, which member opposes to its rotation in compression of the stem 50: in the variant illustrated in the figures 5 and 6 such spring-elastic member is an additional helical spring 23 arranged in compression between the free end of the hinged lever 12 and a projection 25 of the cylindrical body of the device 3.

According to a variant, a spring could be provided directly on the fulcrum 16 of the hinged lever 12.

The second actuating member, in this example the pedal 1, is arranged to exert a traction through a first transmission cable 6 which extends in the case 111 and which is connected, at an opposite end thereof, to a first end 9 of a distribution lever 7, arranged to distribute the braking force imparted through the pedal 1.

The distribution lever 7 is herein constituted by a rigid rod, equipped with a first end 9, with a second end 11 and an intermediate joint 8 around thereof it swings freely, not being constrained to other members, and in particular to the frame of the motorcycle 100.

In the present example, the intermediate joint 8 of the distribution lever 7 is connected to the hinged lever 12 by means of an actuation rod 10 which extends as far as a hooking point 17 on the lever 12.

In this way, a translation of the intermediate joint 8 induced by a tractive force acting on the first transmission cable 6 determines a retroaction on the floating piston 21 mentioned above, through the hinged lever 12 and the stem 50, in opposition to the elastic forces of the springs 22, 23.

Then, the floating piston 21 is arranged to exert a pressure in a transmission fluid in said hydraulic chamber 20 due to the effect of the actuation of a hinged lever 12 connected to said second operating member 1 and to said mechanical actuator of the rear brake 109.

In other words, the hinged lever 12 is configured to provide a first mechanical control to said rear brake 109 and to produce a mechanical push apt to actuate said distribution device 3 and then the hydraulic actuator 108 of the front brake 107 when said second operating member 1 is actuated.

In fact, the second end 11 of the distribution lever 7 instead is connected to the mechanical actuator of the rear brake 109, that is to the jaws of the drum brake, by means of a second transmission cable 15 which is subjected to a traction when the second operating member, that is the pedal 1, exerts a traction on said first transmission cable 6, so as to transmit a braking force to said jaws.

It is to be noted that the force distribution between front brake and rear brake is obtained by acting on the sizes of the distribution lever 7, in particular on the sizes of the overall arm and on the relationship between the lengths of the arms connecting the intermediate joint 8 to the respective ends 9, 11.

In the light of what described, the hinged lever 12, the second operating member 1 and the mechanical actuator of the rear brake 109 are connected therebetween by respective tie rods which are respectively constituted by the first transmission cable 6, by the actuation rod 10 and by the second transmission cable 15, which are connected to the respective ends 9, 11 and to the intermediate joint 8 of the distribution lever 7, free to swing around its own intermediate joint 8 due to the forces received and transmitted at their own free ends.

The distribution lever 7 then has the task of distributing the braking force imparted on the pedal 1, typically assigned to actuate the rear brake, between the latter and the floating piston 21 of the cylindrical body 3, but with an effect so that the force imparted by the pedal 1 is multiplied by the overall arm of the lever 7.

In this way, not only the wished balancing is obtained easily, but it is also possible to transmit to the rear brake 109 a considerable force without other mechanical devices.

If, simultaneously to the action on the pedal 1, also the brake lever is not actuated on the handlebar 104, through the cylindrical body 3 is however transmitted a pressure and then apart from the rear brake 109 even the front brake is activated .

When the brake lever and pedal 1 are actuated, for example to perform an emergency brake, with a certain pressure the herein described integrated braking system provides for the combined actuation both of the rear brake 109 and of front brake 107, by guaranteeing at the same time both a correct distribution of the forces between the two brakes and a suitable advance in actuating the rear brake, so as to make the motion of the motorcycle to be controlled during braking.

To this purpose, the central fulcrum 8 of the distribution lever 7 rotates the hinged lever 12 through said actuation rod 10 by pressing on the actuation end 54 of the stem 50 which acts on said floating piston 21, by exerting a traction thereon and so as to allow the transmission of a braking force to said first actuation member, the gripper 108.

The action of the hinged lever 12 is opposed by a first spring member, that is said first helical spring 22, associated to the floating piston 21, to guarantee both the return of the piston 21 in its own starting position.

Moreover, the second spring member is provided, in the example implemented by the additional helical spring 23, which guarantees the return of the hinged lever 12 in its starting position.

The second spring member 23 also participates in determining with precision the delay in activating the front brake.

Such delay can also be determined by the geometry of the hydraulic chamber and the piston, in particular by the width of the stroke of the latter with respect to the outlet section 4.

In this example, the connection point 17 between actuation rod 10 and the hinged lever 12 positioned suitably between the pressing member 13, which in the example is arranged substantially in the centre of the levers, and the hinged fulcrum 16 of the pressing member 12.

As far as the specific operation of the distribution device 3 is concerned, with particular reference to the figures 4 and 5, the inlet section 5 allows a hydraulic fluid in pressure of the braking system, in particular an oil, to be introduced into the distribution device 3 itself, after actuation of the braking lever 104. When the piston 21 is in resting position, the hydraulic fluid in pressure enters the hydraulic chamber 20 of the device 3 through a terminal aperture 5a and it goes out from the same through the outlet section 4. In this case, the hydraulic chamber 20 does not add any effect to the hydraulic fluid in pressure, behaving as a hydraulic connection .

On the contrary, when the pressing member 13 is compressed, the piston 21 slides by interrupting the hydraulic communication between the terminal aperture 5a of the inlet section 5 and the hydraulic chamber 20 therebetween. In this configuration, the piston 21, further compressed by the compression exerted by the hinged lever 12 on the presser 13, increases the pressure of the hydraulic fluid in the hydraulic chamber 20, by actuating consequently the grippers 108 of the front disc brake.

The distribution device 3 can further include a secondary supply channel 5b apt to allow the entrance of the hydraulic fluid, pushed in pressure by the actuation of the braking lever 104, in the portion of the hydraulic chamber 20 at the back of the piston 21. In this way, the pressure of the hydraulic fluid in the back portion, with an increase in pressure proportional to the stroke imparted to the front brake lever after the actuation thereof by the driver, is added, as effect, to the pressure exerted by the piston 21 deriving from the actuation of the rear brake lever or pedal, by increasing the effect.

It is to be noted that a design variant, for example in the size of brakes, can be faced in a very simple way by applying a variation to the distribution lever 7 and to the spring which constitutes the second spring member, properly outside the cylindrical body 3, without touching then the hydraulic members or the control members.

With reference to figures 6 to 9 a second embodiment example of integrated braking system will be now described, wherein components performing functions analogous to those described with reference to the first embodiment example are designated with the same reference numerals.

As in the preceding example, the pedal 1 projects from the upper plane of the pedal board 110 and it is suitable to be pressed with the action of the foot.

At such pedal board, the integrated system comprises a supporting plate 2 facing the pedal thereto a distribution device 3 is fixed substantially equal to the one previously described, including a substantially cylindrical and hollow body wherein an axial hole defines a hydraulic chamber and which includes a floating piston 21 apt to exert a pressure in a transmission fluid included in said hydraulic chamber 20.

The latter has an inlet section 5, connected to a not represented hydraulic pump which is capable of keeping a fluid inside the hydraulic chamber 20 in pressure, and an outlet section 4 hydraulically connected to a first member for actuating the disc front brake, then sensible to the pressure which is established in said hydraulic chamber 20.

As described previously, the floating piston 21 is movable from a position wherein it locks the outlet section 4 to a position for activating the front brake 107 wherein a hydraulic communication between the inlet section 5 and the outlet section 4 is implemented in said hydraulic chamber 20.

If only the brake lever is controlled on the handlebar 104, that is only the first activation member associated to the hydraulic front brake, the floating piston 21 allows the transmission of such pressure as far as the gripper 108, thus causing the brake of the front brake only, at the discretion of the drivers.

The pedal 1 instead is arranged to exert a traction through a first transmission cable 6 which is connected, at an opposite end, to a distribution lever 7 analogous to the previously described one.

However, in this example the first cable 6 is connected in a hinged way to the intermediate joint 8 of the lever 7.

On the contrary, a first end 9 of the distribution lever 7 is connected, by means of an actuation rod 10, to the hinged lever 12 of the distribution device 3, whereas the second end 11 of the distribution lever is connected, by means of a second transmission cable 15, to the second member for actuating the rear brake 109 (figure 9) .

The distribution lever 7 then has the task of distributing the braking force imparted on the pedal 1, typically assigned to actuate the rear brake, between the latter and the floating piston 21 of the distribution device 3 through the hinged lever 12 acting on said piston 21 in the way that has been described with reference to the first example. In particular, the distribution device 3 used in the present example is the one represented in figures 10 to 13.

If, simultaneously to the action on the pedal 1, also the braking lever is not actuated on the handlebar 104, through the distribution device 3 no pressure is transmitted and then the rear brake 109 only is activated.

On the contrary, if both actuation members, braking lever and pedal 1, are actuated, for example to perform an emergency brake, the herein described integrated braking system provides for the combined actuation both of the rear brake 109 and of front brake 107, by guaranteeing at the same time both a correct distribution of the forces between the two brakes and a suitable advance in actuating the rear brake, so as to make the motion of the motorcycle to be controlled during braking

In fact, the action of the hinged lever 12 is opposed to a certain extent by the helical spring 22 which is included, according to the present example, in the distribution device

3.

Such delay can also be determined by the geometry of the hydraulic chamber and the piston, in particular by the width of the stroke of the latter with respect to the transmission duct .

It is to be noted that the distribution of the forces between front brake and rear brake is obtained by acting on the sizes of the distribution lever 7, in particular on the sizes and on the relationship between the lengths of the two arms wherein it is divided by the intermediate joint 8.

Therefore, a design variant, for example in the size of the brakes, can be faced in a very simple way by applying a variation to the distribution lever 7, without touching the hydraulic members or the controlling members.

To the above-described integrated braking systems a person skilled in the art, with the purpose of satisfying additional and contingent needs, could introduce several additional modifications and variants, however all within the protective scope of the present invention, as defined by the enclosed claims .

Claims

1. A front-rear combined braking system di motorcycle (100), providing a hydraulically operated front brake (107) and a mechanically operated rear brake (109), comprising:

• a first member (104) for operating the front brake (107) and a second member (1) for operating the rear brake (109) both movable between a resting and an operating position;

• a hydraulic actuator (108) of the front brake (107), hydraulically operated by means of said first operating member;

• a mechanical actuator of the rear brake (109); and

• a distribution device (3) inducing the actuation of said hydraulic actuator (108) in response to the actuation of the second controlling member (1), which includes a floating piston (21) inserted in a corresponding hydraulic chamber (20), the floating piston (21) being apt to exert a pressure in a transmission fluid in said hydraulic chamber (20) due to the effect of the actuation of a hinged lever (12) mechanically connected to said second operating member (1) and to said mechanical actuator of the rear brake (109);

• a distribution lever (7) having a rigid rod with a first end (9), a second end (11), and an intermediate joint (8) around which said first and second ends (9, 11) rotate,

wherein the hinged lever (12) is configured to provide a first mechanical control to said rear brake (109) and to produce a mechanical push apt to actuate said distribution device (3) and then the hydraulic actuator (108) of the front brake (107) when said second operating member (1) is actuated, and

wherein the hinged lever (12), the second operating member (1) and the mechanical actuator of the rear brake (109) are connected by respective tie rods (6, 10, 15) to the ends (9, 11) and to the intermediate joint (8) of said distribution lever (7), respectively.

2. The braking system according to claim 1, wherein the second operating member is a pedal (1) arranged at a pedal board of the motorcycle (100) .

3. The braking system according to claim 1 or 2, wherein said second operating member (1) is connected to one of the ends (9, 11) of the distribution lever (7), the hinged lever

(12) being connected to the intermediate joint (8) of the distribution lever (7) .

4. The braking system according to claim 1, 2 or 3, wherein the distribution device (3) is arranged at the front portion of the motorcycle (100) .

5. The braking system according to anyone of the preceding claims, wherein the hydraulically operated front brake (107) is a disc brake controlled by a gripper (108), the first control member thereof is a brake lever (104) arranged on a handlebar of motorcycle (100) .

6. The braking system according to claim 1, wherein the mechanically operated rear brake (107) is a drum brake.

7. The braking system according to anyone of the preceding claims, wherein said hinged lever (12) has a pressing member (13) acting on one end (54) of a stem (50) of the distribution device (3) whereon said floating piston (21) is formed .

8. The braking system according to claim 1, wherein the distribution device (3) includes a spring (22) opposing to the force imparted by said hinged lever (12) .

9. The braking system according to claim 1, wherein the distribution device (3) comprises an outer spring (23) connected to the hinged lever (12) and opposing to the force imparted by said hinged lever (12) .

10. The braking system according to claims 7 and 9, wherein the pressing member (13) is arranged at an intermediate portion of the hinged lever (12), the respective tie rod (10) being connected to the hinged lever (12) on a connection point (17) arranged between the pressing member (13) and the fulcrum (16) of the hinged lever (12) .

11. The braking system according to claim 1, wherein said second operating member (1) is connected to the intermediate joint (8) of the distribution lever (7) .

12. The braking system according to claim 2 or 10, wherein the distribution device (3) is arranged at the pedal board of the motorcycle (100) .

13. The braking system according to claim 7, wherein the pressing member (13) is arranged at the free end of the hinged lever (12) .

14. A motorcycle (100) including a hydraulically operated front brake (107) and a mechanically operated rear brake (109), actuated by an integrated braking system of anyone of the preceding claims.

15. The motorcycle (100) according to claim (14) including, at the steering column, a front shield, and a case (111) formed on the face of the front shield faced towards the driver, the distribution device (3) of the integrated braking system being connected to said front shield inside the case (111) .

16. The motorcycle (100) according to anyone of the preceding claims, wherein said hydraulic chamber (20) comprises an inlet section (5) and an outlet section (4) hydraulically connected to said hydraulic actuator (108); said piston (21) moves inside said hydraulic chamber (20) between a resting position wherein the outlet section (4) is in fluid communication with the inlet section (5) and an operating position wherein said inlet section (5) and outlet section (4) are insulated therebetween and said piston (21) exerts a pressure on the transmission fluid for actuating said hydraulic actuator (108) of the front brake (107) .