JP5771428B2 - Disc brake - Google Patents

Description

  The present invention relates to a disc brake for braking a vehicle such as a motorcycle or a four-wheeled vehicle.

  In some disc brakes, a boss portion for attachment to a vehicle body having an attachment hole is formed in a partially cylindrical shape for weight reduction (see, for example, Patent Document 1).

JP 2011-12719 A

  However, in the above-described disc brake, the heat at the bottom of the bore is difficult to escape, which may cause performance degradation.

  An object of this invention is to provide the disc brake which can suppress the performance fall by heat.

In order to achieve the above object, according to the present invention, an inward protruding portion that protrudes inward in the disk radial direction from a disk circumferential end of the cylinder portion is formed in the partial cylindrical portion, and the disk radius of the cylinder portion is increased. heat transfer portion which is erected protruding from inward face inward of the disk radial direction, it has signed with the inwardly projecting portion and the bottom portion of the bore in the cylinder portion.

  According to the first aspect of the present invention, it is possible to suppress performance degradation due to heat.

It is a front view showing a disc brake of one embodiment concerning the present invention. 1 is a side view showing a disc brake according to an embodiment of the present invention. It is a bottom view showing a disc brake of one embodiment concerning the present invention. It is a perspective view showing a disc brake of one embodiment concerning the present invention. It is a perspective view showing a disc brake of one embodiment concerning the present invention. It is XX sectional drawing of FIG. 1 which shows the disc brake of one Embodiment which concerns on this invention.

  A disc brake according to an embodiment of the present invention will be described with reference to the drawings.

  The disc brake 1 of this embodiment is a disc brake for braking the front wheels of a motorcycle. Of course, the present invention is not limited to this, and can be applied to a disc brake for braking a rear wheel of a motorcycle or a brake of a four-wheeled vehicle.

  As shown in FIGS. 1 to 3, the disc brake 10 includes a disc 11 that rotates with a wheel to be braked, and a caliper 12 that imparts friction resistance to the disc 11. In the following, description will be given with the state of attachment to the vehicle, the circumferential direction (rotation direction) of the disk 11 in this attachment state is referred to as the disk circumferential direction, and the disk 11 passes through the center position of the caliper 12 in the disk circumferential direction. A direction along the radial direction is referred to as a disk radial direction, and a rotation axis direction of the disk 11 is referred to as a disk axis direction.

  The caliper 12 has a caliper body 15 that is attached to a non-rotating portion of the vehicle in a state where the disk 11 is straddled on the outer diameter side. As shown in FIG. 1, the caliper body 15 has a long shape along the circumferential direction of the disk and a cylinder portion 20 disposed on the outer side of the disk 11 (the side opposite to the wheel), along the circumferential direction of the disk. The cylinder part 21 which is long and is disposed on the inner side (wheel side) of the disk 11 as shown in FIG. 3, and the outer side in the disk radial direction of each of the cylinder part 20 and the cylinder part 21 as shown in FIG. 3 to the outer peripheral side of the disk 11 to connect the cylinder part 20 and the cylinder part 21 on the outer side in the radial direction of the disk 11, and as shown in FIG. 3, the intermediate part of the outer side cylinder part 20 in the disk axial direction. It has a pair of boss portions 23, 23 for attachment to the vehicle body provided on both sides in the circumferential direction of the disc at the position. The caliper body 15 is a so-called monoblock type in which the cylinder portions 20 and 21, the bridge portion 22, and the boss portions 23 and 23 are integrally formed by casting.

  As shown in FIG. 1, the above-described bridge portion 22 includes a pair of bridge constituent portions 25 and 25 disposed on both sides of the disk circumferential direction, and a bridge constituent portion 26 disposed between these in the disk circumferential direction. It has become. As a result, the bridge portion 22 includes a bridge configuration portion 25 and a bridge configuration portion 26 on one side in the disk circumferential direction, and a bridge configuration portion 25 and a bridge configuration portion 26 on the other side in the disk circumferential direction. Each has an opening (not shown) penetrating in the disk radial direction.

  The cylinder portion 20 on the outer side has a position between the bridge constituent portion 25 on the one side in the disk circumferential direction and the bridge constituent portion 26 on the central side, and between the bridge constituent portion 25 on the other side in the disc circumferential direction and the bridge constituent portion 26. In each position, a bore 28 along the disk axial direction is formed so as to open facing the disk 11 as shown in FIG. These bores 28, 28 of the cylinder portion 20 are arranged on the same surface where the outer surfaces 29a, 29a of the bottom portions 29, 29 on the opposite side of the disc 11 are continuous, and the outer surface of the caliper body 15 on the outer side in the disc axial direction. Is configured. The inner peripheral surfaces 28a and 28a of the bores 28 and 28 have a circular cross section perpendicular to the disk axis direction, and the inner bottom surfaces 28b and 28b of the bores 28 and 28 are orthogonal to the disk axis direction.

  A bore 31 along the disk axial direction is formed in the inner cylinder portion 21 so as to face each of the bores 28 and 28. In these bores 31, 31, the outer surfaces 32 a, 32 a of the bottom portions 32, 32 on the side opposite to the disk 11 constitute an outer surface on the inner side of the caliper body 15 in the disk axial direction. The inner peripheral surfaces 31a and 31a of the bores 31 and 31 have a circular cross section orthogonal to the disk axis direction, and the inner bottom surfaces 31b and 31b of the bores 31 and 31 are orthogonal to the disk axis direction.

  Although not shown, the bottoms 32 and 32 of the bores 31 and 31 of the inner cylinder portion 21 are tools for cutting in the outer bores 28 and 28 and the inner bores 31 and 31. A bottom through hole is formed through which is inserted. The bottom through-hole is closed by friction stir welding of a separate lid member, and as a result, bottom portions 32 and 32 are formed. On the other hand, the bottom portions 29 and 29 of the bores 28 and 28 of the outer cylinder portion 20 are formed when the caliper body 15 is cast.

  The bores 28 and 31 arranged on the same side in the circumferential direction of the disk have the same diameter and are arranged concentrically, that is, aligned on the same straight line to form a pair. Two pairs are formed apart in the direction. Here, the diameters of the bores 28 and 31 paired on one side of the disk circumferential direction are slightly larger than the diameters of the bores 28 and 31 paired on the other side of the disk circumferential direction. It should be noted that at least one pair of the bores 28 and 31 disposed to face each other is sufficient, and there may be three or more pairs.

  The boss portions 23, 23 on both sides on the outer side are formed with partially cylindrical portions 35, 35 that are partially cylindrical in order to reduce weight. The partial cylindrical portions 35 and 35 each have a mounting hole 36 penetrating along the radial direction of the disk in the center of the inside thereof. In the partial cylindrical portions 35, 35, the outer end portions in the disk radial direction become the seat portions 37 shown in FIG. 1 of mounting bolts (not shown) inserted through the mounting holes 36, and the inner portions in the respective disk radial directions. The end portion becomes a joint portion 38 joined to the vehicle body side. In other words, the caliper 12 is a so-called radial mount type that is fixed to the vehicle body side (specifically, the front fork) with a mounting bolt (not shown) inserted through the mounting holes 36, 36 shown in FIG. In other words, the caliper 12 receives the axial force of the mounting bolt at the partial cylindrical portions 35 and 35 of the boss portions 23 and 23.

  Further, a communication passage 39 shown in FIG. 1 is formed in the outer cylinder portion 20 along the disk radial direction at a central position in the disk circumferential direction. A brake hose (not shown) for supplying and discharging brake fluid into and from the cylinder part 20 and the cylinder part 21 is connected to the communication path 39.

  As shown in FIG. 3, pistons 41 are slidably disposed in the outer-side bores 28 and 28 and the inner-side bores 31 and 31, respectively. Therefore, two pairs of pistons 41, 41 arranged on the same straight line on both sides of the disk 11 and having a predetermined interval in the circumferential direction of the disk are provided. That is, the caliper 12 including the caliper main body 15 and the pistons 41, 41,... Is an opposed piston type four-pot caliper. The diameters of the pistons 41 and 41 paired on one side of the disk circumferential direction are also slightly larger than the diameters of the pistons 41 and 41 paired on the other side of the disk circumferential direction.

  As shown in FIG. 1, the caliper body 15 is provided with two pad pins 43, 43 that are bridged between the cylinder portion 20 and the cylinder portion 21 along the disc axial direction so as to be separated in the disc circumferential direction. . One pad pin 43 is provided between one bridge component 25 and the bridge component 26, and the other pad pin 43 is provided between the other bridge component 25 and the bridge component 26.

  A pair of brake pads 45 and 45 shown in FIGS. 2 and 3 disposed on both sides of the disk 11 are supported by these pad pins 43 so as to be movable in the disk axial direction. As shown in FIG. 3, the above-described pistons 41, 41,... Are arranged on the opposite sides of the brake pads 45, 45 from the disk 11, and these pistons 41, 41,. 3 slides in the bores 28, 28, 31, 31 and moves in the direction of the disk 11 by the brake fluid pressure introduced into the bores 28, 28, 31, 31 shown in FIG. As a result, brake pads 45, 45 provided between the pistons 41, 41,... And the disk 11 are pressed against the disk 11 to generate a braking force on the vehicle. Note that at least one pair of brake pads 45 and 45 may be provided. For example, a plurality of pairs may be provided so as to correspond one-to-one with the piston 41.

  In the present embodiment, the above-described partial cylindrical portions 35 and 35 of the boss portions 23 and 23 and the bottom portions 29 and 29 of the bores 28 and 28 of the cylinder portion 20 are connected to each other, Rib-shaped heat transfer portions 50 and 50 shown in FIGS. 1 to 6 are erected so as to protrude inward in the disk radial direction from the cylinder portion 20.

  The bore 28, the boss 23, and the heat transfer portion 50 on one side in the circumferential direction of the disk and the bore 28, the boss portion 23, and the heat transfer portion 50 on the other side in the circumferential direction of the disk are portions associated with slightly different diameters of the bore 28 Other than the above, since they have a common substantially mirror-symmetric shape, the bore 28, the boss portion 23, and the heat transfer portion 50 on one side in the disk circumferential direction will be further described below as an example.

  As shown in FIGS. 4 and 5, the partial cylindrical portion 35 is formed over the entire length of the boss portion 23 in the disk radial direction. As shown in FIG. 3, the partial cylindrical portion 35 protrudes on the side opposite to the disc 11 in the disc axial direction from the outer side cylinder portion 20, and thereby the boundary between the cylinder portion 20 and each other. A recessed portion 51 that is recessed when viewed from the inner side in the disk radial direction is formed in the vicinity of the position. Further, the partial cylindrical portion 35 protrudes on the opposite side of the outer circumferential side cylinder portion 20 from the disk circumferential bore 28 which is a direction orthogonal to the disk rotation axis, as shown in FIGS. 4 and 5. Thus, it also protrudes inward in the disk radial direction, which is a direction orthogonal to the disk rotation axis. The protruding tip of the inward protruding portion 52 that protrudes inward in the radial direction of the disk from the cylinder portion 20 of the partial cylindrical portion 35 is the above-described joint portion 38 to the vehicle body side. The inward projecting portion 52 has a substantially cylindrical shape in which a portion on the joint portion 38 side is continuous over the entire circumference.

  As shown in FIG. 3, the heat transfer portion 50 is inclined so that the connecting portion 54 to the partial cylindrical portion 35 is located on the disc 11 side in the disc axial direction rather than the connecting portion 53 to the bottom portion 29. The connecting portion 54 is connected to the inward protruding portion 52 of the partial cylindrical portion 35. The entire connecting portion 54 overlaps with the inward projecting portion 52 in the disc axial direction, and is disposed in a range on the opposite side of the disc 11 from the center of the mounting hole 36. In other words, the entire connecting portion 54 of the heat transfer portion 50 extends in the disc axial direction from the end of the inward projecting portion 52 opposite to the disc 11 to the disc 11 side to the center of the mounting hole 36. Are arranged within.

  Further, the entire connecting portion 54 of the heat transfer portion 50 overlaps the position of the inward protruding portion 52 also in the disk circumferential direction, and the range on the bore 28 side in the disk circumferential direction from the center of the mounting hole 36. Is arranged. In other words, the connecting portion 54 of the heat transfer portion 50 is disposed within the range from the end on the bore 28 side of the inward protruding portion 52 to the center of the mounting hole 36 on the side opposite to the bore 31 in the disk circumferential direction. Has been.

  As shown in FIG. 6, the heat transfer section 50 has a shape in which the thickness decreases toward the inner side in the disk radial direction, and the end surface 50 a on the inner side in the disk radial direction is the thinnest, and the thickness of the heat transfer section 50 is It is located on the most central side in the vertical direction.

  According to the disc brake 10 of the present embodiment described above, frictional heat is generated between the disc 11 and the brake pads 45 and 45 during braking, and the frictional heat is mainly generated in the brake pad 45 on the outer side. The frictional heat is transmitted from the brake pad 45 to the bores 28 and 28 of the outer cylinder portion 20 via the outer pistons 41 and 41 and the brake fluid. This heat is transferred to the bottom of the bores 28 and 28. The heat transfer portions 50 and 50 can be favorably transmitted from the 29 and 29 sides to the partial cylindrical portions 35 and 35 of the boss portions 23 and 23 and can be released from the joint portions 38 and 38 to the vehicle body side. Therefore, the heat dissipation performance of the caliper 12 can be improved, and the performance degradation due to heat, in particular, the dynamic performance degradation due to the temperature rise of the bottom portions 29 and 29 of the bores 28 and 28 can be suppressed. Moreover, since the temperature of the brake fluid in the bores 28 and 28 can be lowered, the occurrence of vapor lock can be suppressed. In addition, since the temperature of the bores 28 and 28 and the temperature of a seal (not shown) between the bores 28 and 28 and the pistons 41 and 41 can be lowered, the operation feeling of the brake lever when hot is improved. It is possible to improve the reliability against leakage of brake fluid. Furthermore, since the temperature of the brake pads 45 can be lowered, the occurrence of fade can be suppressed and the warpage can be reduced.

  In addition, since the heat transfer section 50 inclined with respect to the circumferential direction of the disk guides the traveling air outside the cylinder section 20 to the disk 11 side and the boss section 23 side of the cylinder section 20, the overall cooling efficiency of the caliper 12 Can be improved. Moreover, since the temperature of the boss | hub part 23 itself can be lowered | hung by this, the axial force of a mounting bolt can be stabilized and the deformation | transformation of the boss | hub part 23 can be suppressed.

DESCRIPTION OF SYMBOLS 10 Disc brake 11 Disc 20 Cylinder part 23 Boss part 28 Bore 29 Bottom part 35 Partial cylindrical part 36 Mounting hole 41 Piston 45 Brake pad 50 Heat-transfer part

Claims (4)

At least a pair of brake pads disposed on both sides of the disc;
At least a pair of pistons disposed on both sides of the disk to press the pair of brake pads against the disk;
Have a bore in which the piston slides, the cylinder portion forming a long shape along the circumferential direction of the disk,
Provided in the disk circumferential direction on both sides of the cylinder portion, in a disc brake and a boss portion having a partially cylindrical portion projecting along a direction perpendicular to the disk axis of rotation have a inside the mounting hole,
The partial cylindrical portion is formed with an inward protruding portion that protrudes inward in the radial direction of the disc from the circumferential end of the cylinder portion.
From the disk radially inner surface protrudes into the disc radially inwardly heat transfer portion which is erected of the cylinder portion, it is made form by connecting the bottom of the bore in the cylinder portion and the inward protrusion Disc brakes characterized by In the vicinity of the boundary position between the partial cylindrical portion and the cylinder portion, there is a concave portion formed by the inner projecting portion, the cylinder portion, and the heat transfer portion as seen from the inner side in the disk radial direction. The disc brake according to claim 1, wherein the disc brake is provided. The heat transfer section, and a first second connecting portion and the connecting portion you connected to said partially cylindrical portion of the coupling to the bottom of the bore, the first connecting portion in the disk rotational axis 3. The disc brake according to claim 1, wherein the second connecting portion is inclined and disposed so as to be positioned on the disc side. The heat transfer part has a first connection part connected to the bottom part of the bore and a second connection part connected to the partial cylindrical part, and the second connection part is in the disc rotation axis direction. The disc brake according to any one of claims 1 to 3, wherein the disc brake is disposed in a range on the opposite side of the disc from the center of the mounting hole.

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