JP4572782B2 - Disc brake device - Google Patents

Description

  The present invention relates to a disc brake device, and in particular, a brake piston fitted in a cylinder portion of a caliper so as to be slidable in an axial direction is pushed in the axial direction according to an operating force, and an inner pad and an outer pad are respectively The pad is configured to be pushed toward the disk rotor, and the friction force in the rotor circumferential direction of each pad and the disk rotor at the time of braking is taken out as an anchor load (braking reaction force). The present invention relates to a disc brake device configured to be converted into a servo load directed to the disc rotor by a mechanism and added to each pad.

This type of disc brake device is disclosed, for example, in Patent Document 1 below, and in this disc brake device, a first load that adds an anchor load taken out by an inner pad at the time of forward braking as a servo load to the inner pad. A bell crank, a second bell crank that applies an anchor load taken out by the outer pad during forward braking as a servo load to the outer pad, and a second bell crank that adds an anchor load taken out by the inner pad as a servo load to the inner pad during reverse braking. 3 and a fourth bell crank for adding an anchor load taken out by the outer pad during reverse braking to the outer pad as a servo load.
JP-A-6-280909

  In the disc brake device described in Patent Document 1 described above, the first and second bell cranks operate during forward braking to apply a servo load to the inner pad and outer pad, and third and fourth during reverse braking. Since the bell crank is actuated to apply a servo load to the inner pad and the outer pad, it is possible to obtain a large braking force with a small operating force at each braking.

  However, in the disc brake device described in Patent Document 1 described above, the corresponding pad (for example, the inner pad) is activated by the operation of the corresponding bell crank to which the anchor load taken out by the corresponding pad (for example, the inner pad or the outer pad) is applied. Pad or outer pad) as a servo load. For this reason, when water is applied to each pad and the friction coefficient at the corresponding pad (for example, inner pad or outer pad) becomes abnormally high and the anchor load becomes abnormally high, such as a phenomenon that occurs just before this pad dries. The pad pressing force obtained by the corresponding pad (for example, the inner pad or the outer pad) may be excessively increased, and as a result, the braking force may be excessively increased. Note that the above phenomenon usually occurs at the inner pad and the outer pad at the same time because there is a time difference in the generation timing depending on the amount of water applied.

  The present invention has been made to solve the above-described problems, and a braking piston fitted to a cylinder portion of a caliper so as to be slidable in the axial direction is pushed in the axial direction in response to an operating force, thereby The pad and the outer pad are respectively pushed toward the disk rotor, and the frictional force in the rotor circumferential direction of each pad and the disk rotor at the time of braking is taken out as an anchor load. In the disc brake device configured to be converted into a servo load directed to the disc rotor by a mechanism and added to each pad, the servo mechanism sends an anchor load taken out by the inner pad to the outer pad. A functional component to be added as a servo load and an anchor load taken out by the outer pad are used as the inner load. It is characterized in head that has a functional component to be added as a servo load.

  In this case, the servo mechanism includes a first lever that applies an anchor load taken out by the inner pad during forward braking as a servo load to the outer pad, and an anchor load taken out by the outer pad during forward braking. A second lever for adding a servo load to the outer pad, a third lever for adding an anchor load taken out by the inner pad as a servo load during reverse braking, and an anchor load taken out by the outer pad during reverse braking. It is also possible to provide a fourth lever that is added to the inner pad as a servo load. Preferably, the first lever and the second lever are supported by a common support pin, and the third lever and the fourth lever are supported by a common support pin.

  The servo mechanism includes a forward lever that applies an anchor load taken out by the inner pad or the outer pad during forward braking as a servo load to the outer pad or the inner pad, and an inner pad or the outer pad during backward braking. It is also possible to provide a reverse lever that applies the anchor load taken out as a servo load to the outer pad or the inner pad.

  In the disc brake device according to the present invention, during braking, the frictional force in the rotor circumferential direction of each pad (inner pad and outer pad) and the disc rotor is taken out as an anchor load, and this anchor load is applied to the disc rotor by a servo mechanism. It is converted to the servo load directed and added to each pad. For this reason, a large braking force can be obtained with a small operating force during braking.

  By the way, in the disc brake device according to the present invention, the servo mechanism adds the anchor load taken out by the inner pad as a servo load to the outer pad and the anchor load taken out by the outer pad as a servo load to the inner pad. It has functional parts. For this reason, although the water is applied to each pad and the friction coefficient at the corresponding pad (for example, the inner pad or the outer pad) becomes abnormally high and the anchor load becomes abnormally high, as a phenomenon that occurs just before the pad is dried, Even when the friction coefficient at the other side pad (for example, the outer pad or the inner pad) is not abnormally high and the anchor load does not become abnormally high, the anchor load taken out from the corresponding pad is applied to the other side pad as a servo load. At the same time, an anchor load taken out from the other pad is added as a servo load to the corresponding pad. Therefore, also in this case, the braking force obtained at each pad is balanced, and the braking force obtained at the corresponding pad is prevented from excessively increasing.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a first embodiment in which the present invention is applied to a disc brake device for a vehicle. The disc brake device of the first embodiment is a disc that rotates integrally with a wheel (not shown). A pair of inner pads 12 and outer pads 13 that can sandwich the rotor 11, and braking that can push these pads 12 and 13 toward the respective braking surfaces of the disk rotor 11 in the rotor axial direction (left and right direction in FIG. 1). A piston 14 and a movable caliper 15 are provided.

  The inner pad 12 is pressed and pressed by the brake piston 14 toward the disc rotor 11 by the back metal 12a during braking, and brakes the disc rotor 11 by the lining 12b. The inner pad 12 is assembled to the vehicle body (not shown). The mounting 16 is attached so as to be movable in the rotor axial direction and the rotor circumferential direction. On the other hand, during braking, the outer pad 13 is pushed and pressed toward the disk rotor 11 by the reaction arm 15a of the caliper 15 by the back metal 13a, and brakes the disk rotor 11 by the lining 13b. It is assembled to a mounting 16 assembled (not shown) so as to be movable in the rotor axial direction and the rotor circumferential direction.

  The brake piston 14 is fitted to the cylinder portion 15b of the caliper 15 through a seal ring 17 having a retract function so as to be slidable in the cylinder axial direction, and an oil chamber Ro is formed in the cylinder portion 15b. It is configured to be pushed / pressed in the axial direction toward the inner pad 12 in accordance with the hydraulic pressure supplied to the chamber Ro. The oil chamber Ro communicates with the oil chamber of the brake master cylinder MC that operates in response to depression of the brake pedal BP, and is configured to be able to supply hydraulic pressure corresponding to the operating force from the oil chamber of the brake master cylinder MC. .

  The caliper 15 has the above-described reaction force arm portion 15a and cylinder portion 15b, and also has connecting arm portions 15c for connecting them, and each connecting arm portion 15c has a rotor shaft as well known to the mounting 16. It is assembled to be movable in the direction. When the hydraulic pressure from the brake master cylinder MC is supplied to the oil chamber Ro and the brake piston 14 is pushed / pressed toward the inner pad 12, the caliper 15 reacts with the mounting shaft 16 with respect to the mounting 16. The outer pad 13 is pushed and pressed toward the disc rotor 11 by the reaction force arm portion 15a.

  Further, in the disc brake device of the first embodiment, the frictional force in the rotor circumferential direction of the pads 12 and 13 and the disc rotor 11 at the time of braking is taken out as an anchor load, and this anchor load is applied to the servo mechanism 20. Thus, it is converted into a servo load directed to the disk rotor 11 and added to each of the pads 12 and 13. The servo mechanism 20 includes first to fourth levers 21, 22, 23, and 24 that are assembled to the mounting 16.

  The first lever 21 and the second lever 22 are assembled to the mounting 16 via a support pin 25 so as to be swingable. The first lever 21 is engaged at one end with the forward braking side end of the back metal 12a in the inner pad 12, and is engaged at the other end with the back surface of the back metal 13a in the outer pad 13 so that the inner pad 12 is engaged during forward braking. It has a function of adding the anchor load taken out at the outer pad 13 as a servo load. The second lever 22 is engaged at one end with the forward braking side end of the back metal 13a of the outer pad 13 at one end, and is engaged with the rear surface of the back metal 12a at the inner pad 12 at the other end. It has a function of adding the anchor load taken out as a servo load to the inner pad 12.

  The third lever 23 and the fourth lever 24 are assembled to the mounting 16 via a support pin 26 so as to be swingable. The third lever 23 is engaged at one end with the reverse braking side end of the back metal 12a of the inner pad 12, and is engaged with the back surface of the back metal 13a of the outer pad 13 at the other end. It has a function of adding the anchor load taken out at the outer pad 13 as a servo load. The fourth lever 24 is engaged at one end with the reverse braking side end of the back metal 13a of the outer pad 13 at one end, and is engaged with the back surface of the back metal 12a at the inner pad 12 at the other end. It has a function of adding the anchor load taken out as a servo load to the inner pad 12.

  In the disc brake device of the first embodiment configured as described above, when the brake pedal BP is depressed, the hydraulic pressure corresponding to the operating force is supplied from the oil chamber of the brake master cylinder MC to the oil chamber Ro of the caliper 15. The Therefore, the braking piston 14 is pushed and pressed in the axial direction toward the inner pad 12 to push and push the inner pad 12 toward the disk rotor 11, and the reaction force of the caliper 15 is caused by the reaction force. The portion 15 a is pushed / pressed in the axial direction toward the outer pad 13 to push / press the outer pad 13 toward the disc rotor 11, and the inner pad 12 and the outer pad 13 sandwich the disc rotor 11. As a result, a braking force is generated between the pads 12 and 13 and the disk rotor 11 (the linings 12b and 13b at the pads 12 and 13 and the frictional force in the circumferential direction of the disk rotor 11), and the disk rotor 11 is braked. Is done.

  By the way, in the disc brake device of the first embodiment, a servo mechanism 20 including first to fourth levers 21, 22, 23, and 24 is provided. For this reason, water is applied to each of the pads 12 and 13, and the friction coefficient at the corresponding pad (for example, the inner pad 12 or the outer pad 13) becomes abnormally high and the anchor load becomes abnormal as a phenomenon that occurs just before the pad is dried. However, when the friction coefficient at the other side pad (for example, the outer pad 13 or the inner pad 12) does not increase abnormally and the anchor load does not increase abnormally, the anchor load taken out from the corresponding pad is While being applied as a servo load to the pad on the side, the anchor load taken out from the pad on the other side is added as a servo load to the corresponding pad. Accordingly, in this case as well, the braking force obtained at each pad 12, 13 is balanced, and the braking force obtained at the corresponding pad is prevented from excessively increasing.

  FIG. 2 shows the friction coefficient μ of the other pad when the friction coefficient μ of one of the inner pad 12 and the outer pad 13 is fixed to 0.4 on the basis of the friction coefficient μ of the other pad. It is a characteristic diagram which showed the relationship between the change rate of a brake effectiveness coefficient (BEF). Therefore, when the friction coefficient μ of the other pad is 0.4, it is the same as the reference value, so the BEF change rate is 1. The characteristic indicated by the solid line is obtained when the above-described embodiment is implemented, and is fixed when the friction coefficient μ of one pad is fixed to 0.4 and the friction coefficient μ of the other pad is changed. It shows the relationship. Further, as a comparative example, in the case of Japanese Patent Laid-Open No. 6-280909 exemplified as the background art, the friction coefficient μ of one pad is fixed to 0.4, and the friction coefficient μ of the other pad is changed. The characteristics in this case are indicated by broken lines.

  In the first embodiment described above, the servo mechanism 20 including the first to fourth levers 21, 22, 23, and 24 is employed, but the function of adding an anchor load as a servo load during reverse braking is unnecessary. In some cases, the third lever 23 and the fourth lever 24 can be eliminated to implement the present invention. Further, in the first embodiment described above, the present invention employing the servo mechanism 20 shown in FIG. 1 has been implemented, but the servo mechanism 120 of the second embodiment shown in FIG. 3 or shown in FIG. It is also possible to implement the present invention by adopting the servo mechanism 220 of the third embodiment.

  The servo mechanism 120 of the second embodiment shown in FIG. 3 includes a forward lever 121 and a reverse lever 122. The forward lever 121 is swingably assembled to the mounting 16 via a support pin 123, and a wedge-shaped projection formed on the back side of the forward brake side of the back metal 12a in the inner pad 12 by a projection 121a formed at one end. 12a1 is engaged with a wedge-shaped protrusion 13a1 formed on the back side of the back brake 13a of the back pad 13a on the outer pad 13 by a protrusion 121b formed on the other end, and is taken out by the inner pad 12 during forward braking. It has a function of adding an anchor load to the outer pad 13 as a servo load and a function of adding an anchor load taken out by the outer pad 13 to the inner pad 12 as a servo load.

  On the other hand, the reverse lever 122 is swingably assembled to the mounting 16 via a support pin 124, and is formed on the reverse braking side rear surface of the back metal 12a in the inner pad 12 by a protrusion 122a formed at one end. Engage with the wedge-shaped protrusion 12a2 and engage with the wedge-shaped protrusion 13a2 formed on the back brake side rear surface of the back pad 13a of the outer pad 13 with the protrusion 122b formed on the other end. It has a function of adding the extracted anchor load to the outer pad 13 as a servo load and a function of adding the anchor load extracted by the outer pad 13 to the inner pad 12 as a servo load.

  The configuration other than the servo mechanism 120 of the second embodiment shown in FIG. 3 is substantially the same as the configuration other than the servo mechanism 20 of the first embodiment shown in FIG. Description is omitted. Moreover, since the effect of this 2nd Embodiment is substantially the same as the effect of 1st Embodiment mentioned above, the description is abbreviate | omitted.

  The servo mechanism 220 according to the third embodiment shown in FIG. 4 includes a forward lever 221 and a reverse lever 222. The forward lever 221 is swingably assembled to the mounting 16 via a support pin 223, and can be tilted to the forward braking side end portion of the back metal 12a of the inner pad 12 by a protrusion 221a formed at one end portion. It engages with the tip of the link 12c that is assembled, and engages with the tip of the link 13c that is tiltably assembled to the forward braking side end of the back metal 13a in the outer pad 13 by a projection 221b formed at the other end. In addition, at the time of forward braking, it has a function of adding an anchor load taken out by the inner pad 12 as a servo load to the outer pad 13 and a function of adding an anchor load taken out by the outer pad 13 to the inner pad 12 as a servo load.

  On the other hand, the reverse lever 222 is swingably assembled to the mounting 16 via a support pin 224, and is tilted to the reverse brake side end of the back metal 12a of the inner pad 12 by a protrusion 222a formed at one end. Engage with the tip of the link 12d that can be assembled, and engage with the tip of the link 13d that can be tilted to the rear brake side end of the back pad 13a of the outer pad 13 by the protrusion 222b formed at the other end. In addition, at the time of reverse braking, the anchor load taken out by the inner pad 12 is added as a servo load to the outer pad 13 and the anchor load taken out by the outer pad 13 is added to the inner pad 12 as a servo load. Yes.

  The configuration other than the servo mechanism 220 of the third embodiment shown in FIG. 4 is substantially the same as the configuration other than the servo mechanism 20 of the first embodiment shown in FIG. Description is omitted. Moreover, since the effect of this 3rd Embodiment is substantially the same as the effect of 1st Embodiment mentioned above, the description is abbreviate | omitted.

  In each of the above-described embodiments, the first to fourth levers 21, 22, 23, and 24 of the servo mechanism 20, the forward lever 121 and the reverse lever 122 of the servo mechanism 120, and the forward lever 221 and the reverse lever of the servo mechanism 220 are reversed. Although the mounting lever 222 is swingably assembled to the mounting 16, it can also be mounted to the caliper 15 so as to be swingable. Further, in each of the above-described embodiments, the present invention is applied to the movable caliper type disc brake device. However, the present invention can be applied to other types of disc brake devices in the same manner as in the above-described embodiment or appropriately modified. It is possible to implement.

1 is a diagram schematically showing a first embodiment of a disc brake device according to the present invention. FIG. The friction coefficient (μ) of the other pad when the friction coefficient of the other pad fluctuates, with the friction coefficient of one of the inner pad and outer pad shown in FIG. It is the characteristic line figure which showed the relationship with the change rate of a brake effectiveness coefficient (BEF) with the continuous line, and showed the comparative example with the broken line. It is a figure showing roughly a 2nd embodiment of a disc brake device by the present invention. It is a figure showing roughly a 3rd embodiment of a disc brake device by the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Disc rotor, 12 ... Inner pad, 12a ... Inner pad back metal, 12b ... Inner pad lining, 13 ... Outer pad, 13a ... Outer pad back metal, 13b ... Outer pad lining, 14 ... Brake piston, 15 ... Caliper, 15b ... Cylinder part, 16 ... Mounting, 20 ... Servo mechanism, 21 ... First lever, 22 ... Second lever, 23 ... Third lever, 24 ... Fourth lever, BP ... Brake pedal, MC ... Brake master cylinder

Claims (4)

  The brake piston fitted to the caliper cylinder so as to be slidable in the axial direction is pushed in the axial direction according to the operating force, and the inner pad and outer pad are pushed toward the disc rotor, respectively. Then, the frictional force in the rotor circumferential direction of each pad and the disk rotor at the time of braking is taken out as an anchor load, and this anchor load is converted into a servo load directed to the disk rotor by a servo mechanism. In the disc brake device configured to be applied to a pad, the servo mechanism includes a functional component that adds an anchor load taken out by the inner pad as a servo load to the outer pad, and an anchor load taken out by the outer pad. It is equipped with a functional part that adds a servo load to the inner pad. Disc brake device according to claim.   2. The disc brake device according to claim 1, wherein the servo mechanism takes out an anchor load taken out by the inner pad during forward braking as a servo load to the outer pad and is taken out by the outer pad during forward braking. A second lever for applying an anchor load as a servo load to the inner pad, a third lever for applying an anchor load taken out by the inner pad as a servo load to the outer pad at the time of reverse braking, and an outer pad at the time of reverse braking. A disc brake device comprising a fourth lever for applying the anchor load taken out as a servo load to the inner pad.   3. The disc brake device according to claim 2, wherein the first lever and the second lever are supported by a common support pin, and the third lever and the fourth lever are supported by a common support pin. Disc brake device characterized. 2. The disc brake device according to claim 1, wherein the servo mechanism includes a forward lever for applying an anchor load taken out by the inner pad or the outer pad as a servo load to the outer pad or the inner pad during forward braking, and a reverse drive. A disc brake device comprising a reverse lever for applying an anchor load taken out by the inner pad or the outer pad during braking to the outer pad or the inner pad as a servo load.

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