JP2017110755A - Disc rotor for vehicular disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ventilated disc rotor for a vehicular brake of which cooling performance is low at the time of its high speed rotation to cause its over-cooling to be hardly produced and in turn at the time of its low speed rotation to cause its high cooling performance to be sufficiently kept.SOLUTION: This invention relates to a ventilated disc rotor 10 for a vehicular disc brake comprising two annular-shaped discs 11 oppositely arranged in spaced-apart relation, many fins 12 integrally connected to each of opposing surfaces of the two discs 11 and extending substantially in a radial direction and many ventilation spaces 15 enclosed by the two discs 11 and adjoining two fins 12. At least certain fins 12A are provided with protrusions 13 and another fin 12B adjacent to the side of the protrusion of the fins 12A provided with the protrusions 13 is formed with holes 14 at positions opposing against the protrusions 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a disc brake device that brakes a brake by pressing a brake pad against a rotating disc rotor, and more particularly, to a structure of a disc rotor for cooling frictional heat generated during braking.

  A disk brake device is well known as a brake device for automobiles. A disc brake device is a device that generates friction by sandwiching a disc rotor, which is a metal disk that rotates with the wheels, between brake pads to which a friction material is applied, and brakes by stopping the rotation of the disc rotor. .

  When the friction material applied to the brake pad becomes high temperature and vaporizes due to frictional heat generated during brake braking, a fade phenomenon occurs in which friction is reduced, and the braking effect is reduced. Furthermore, if the brake body overheats, the brake oil will boil and bubbles will be generated inside the fluid system, causing a vapor lock phenomenon where force cannot be transmitted.

  In order to solve such a problem, it is necessary to prevent overheating due to frictional heat generated by brake braking. A ventilated disk rotor shown in FIG. 5 is known as a structure for dissipating frictional heat and cooling it efficiently.

  FIG. 4 is a diagram schematically showing a basic shape of a general disk rotor. The disk rotor 100 is made of metal and has a disk shape. Although a detailed structure is not shown here, an axle 20 that is a rotating shaft of a tire and a wheel is integrated at the center of the disc rotor 100, and the disc rotor rotates together with the axle 20.

  FIG. 5 is a cutaway view of a part of a conventional ventilated disk rotor, and is a view substantially corresponding to a part of the II cross section of FIG. The direction of rotation of the disk rotor 100 is indicated by X. The ventilated disc rotor 100 includes two annular discs 111 arranged to face each other at a predetermined interval, and a large number of fins 112 arranged between the discs 111. Furthermore, a large number of ventilation spaces 115 that are spaces surrounded by two disks 111 and two adjacent fins 112 are provided.

  In FIG. 5, in order to show the structure of the fin 112 inside the disc rotor 100, one of the discs 111 is shown in a notched state. Both side edges of each fin 112 are integrally connected to the opposing surfaces of the two disks 111. Each fin 112 extends in a substantially radial direction from the inner peripheral edge to the outer peripheral edge of the disk 111 in a side cross-section. A ventilation space 115 is formed by two disks 111 and two adjacent fins 112. When the disk rotor 100 rotates, outside air enters from the inner peripheral opening 115A, passes through the ventilation space 115, and is discharged from the outer peripheral opening 115B. Thus, by letting outside air pass through, the frictional heat generated by the friction between the brake pad and the disc rotor 100 is dissipated and cooled.

As a characteristic of the shape of the fin, a disk rotor shown in Patent Document 1 is known. This is because by setting the number of fins to be n times the number of fastening portions, the rigidity of the disk rotor can be made uniform over the entire circumference, and undulations generated on the friction surface during braking can be suppressed. it can.
Further, a ventilated disc rotor disclosed in Patent Document 2 is known as a feature of the fin shape and arrangement in order to efficiently release the frictional heat generated during brake braking. This is because the disk rotor fins are formed in a curved shape that is more directed toward the center of the disk than the outer peripheral tangent, and the inner peripheral tip is tapered to form a plurality. The inflow of cooling air can be increased, and the taken-in air can be efficiently brought into contact with the fins, so that heat can be exchanged efficiently.

JP 2014-219091 A JP 2000-74109 A

  In general, the disk cooling performance can be improved by increasing the surface area by increasing the number of fins. However, when such a disc is used at a high speed, the disc temperature becomes too low, and there is a problem in that the performance of the brake pad cannot be exhibited sufficiently. Further, if the cooling performance is lowered in order to avoid such overcooling, there is a problem that cooling at low rotation is insufficient and overheating occurs.

  An object of the present invention is to provide a ventilated disc rotor for an automotive disc brake that has a low cooling performance when used at high speeds and is unlikely to be supercooled, and has a sufficiently high cooling performance when used at low speeds.

In order to achieve the above object, the present invention provides the following configuration. In addition, the code | symbol in a parenthesis is a code | symbol in drawing mentioned later, and attaches | subjects it for reference.
According to the aspect of the present invention, two annular discs (11) arranged to face each other with a space therebetween, and the opposing surfaces of the two discs (11) are integrally connected to each other and extend substantially radially. Ventilated vehicle disc brake comprising a plurality of fins (12) and a plurality of ventilation spaces (15) surrounded by the two discs (11) and two adjacent fins (12). A disc rotor (10), wherein a projection (13) is provided on at least a part of the fin (12A), and the side of the fin (12A) on which the projection (13) is provided has the projection (13) Another fin (12B) adjacent to is provided with a hole (14) at a position facing the projection (13).

  Said aspect WHEREIN: The said protrusion (13) is provided in the at least one position near the inner peripheral side and outer peripheral side in the said fin (12A), It is characterized by the above-mentioned.

  Said aspect WHEREIN: The said processus | protrusion (13) is provided with 1 or 2 or more with respect to one said fin (12A), It is characterized by the above-mentioned.

  According to the ventilated disc rotor of the present invention, the air flow is disturbed by the projections and holes of the fins at the time of high rotation use, and the cooling effect can be reduced by reducing the air volume, and it is difficult to overcool. In addition, when using at a low speed, the air turbulence due to the protrusions and holes is small, so that the cooling performance can be ensured to be equal to or higher than the conventional one.

  According to the ventilated disk rotor of the present invention, the surface area and the air volume can be adjusted by changing or combining the number and position of the protrusions and the holes facing the protrusions, thereby controlling the cooling performance. be able to.

FIG. 1 is a partial perspective view of a configuration example in an embodiment of a ventilated disc rotor according to the present invention, with one disc cut away. FIG. 2 is a horizontal sectional view of the ventilated disc rotor having the configuration example shown in FIG. FIG. 3 is a graph comparing the cooling performance of a ventilated disk rotor according to the present invention and a conventional disk rotor. FIG. 4 is a schematic perspective view schematically showing a basic shape of a general disk rotor. FIG. 5 is a partial perspective view of a configuration example of a conventional ventilated disc rotor in which one disc is cut out.

  Hereinafter, a ventilated disk rotor according to the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same or similar component in each drawing.

  FIG. 1 is a partially cutaway perspective view schematically showing a configuration example in an embodiment of a ventilated disk rotor (hereinafter sometimes abbreviated as “disk rotor”) according to the present invention. FIG. 6 is a view substantially corresponding to a part of a II cross section of a general disk rotor shape. In order to show the structure of the fins 12 inside the disk rotor 10, one of the disks 11 is shown in a cut-out state. FIG. 2 is a schematic horizontal cross-sectional view of the disk rotor 10 shown in FIG. This corresponds to a part of the II-II cross section of the general disk rotor shape shown in FIG. Hereinafter, the radial direction of the disk rotor 10 is referred to as “radial direction”, and the thickness direction is referred to as “width direction”. The direction of rotation of the disk rotor 10 is indicated by the symbol X.

  The disk rotor 10 is made of metal, and has two ring-shaped disks 11 arranged to face each other at a predetermined interval, and a large number of fins disposed between the disks 11 at substantially equal intervals in the circumferential direction. Twelve. Both side edges in the width direction of each fin 12 are integrally connected to the opposing surfaces of the two disks 11. As a result, a large number of ventilation spaces 15, which are spaces surrounded by the two disks 11 and the two adjacent fins 12, are formed.

  The basic shape of the fin 12 will be described. The fins 12 extend in a substantially radial direction from the inner peripheral side to the outer peripheral side of the disk 11 in a side cross section. The length, width and thickness of each fin 12 in the radial direction, the total number of fins 12, the spacing of the arrangement, and the like are not particularly limited. However, as long as the principle of the present invention is followed, the conventional ventilated disk rotor design It can be designed based on the idea.

  In the present invention, at least some of the fins 12A are provided with protrusions 13 extending from the radial intermediate position. The protrusion 13 is provided on the fin first surface 121 </ b> A side that is the surface opposite to the rotation direction X. The protrusion 13 branches off from the fin 12A along a smooth curve, and extends in the direction of the fin 12B adjacent to the fin first surface 121A side. As shown in FIG. 1, it is preferable that the angle α formed by the inner peripheral side direction of the fin 12A and the extending direction of the protrusion 13 is an obtuse angle. The length of the protrusion 13 is not particularly limited. However, the tip of the protrusion 13 does not reach the adjacent fin 12B, and there is a gap between them.

  Further, a hole 14 is formed in a position facing the protrusion 13 in the adjacent fin 12B. As shown in FIG. 1, it is preferable that the outer peripheral side boundary of the hole 14 of the fin 12B is located on a virtual extension line extending along the protrusion 13 of the fin 12A.

  In the illustrated example, the protrusion 13 is provided closer to the outer peripheral side of the fin 12A. However, the protrusion 13 is not limited to this, and may be provided closer to the inner peripheral side, or may be provided at the center position. . The hole 14 in the adjacent fin 12B is basically provided at a position facing the protrusion 13 of the fin 12A. As another example, a plurality of protrusions 13 may be provided in one fin 12A, and in that case, a plurality of holes 14 respectively facing the plurality of protrusions 13 are also formed in the adjacent fin 12B. As yet another example, a protrusion 13 may be provided at a location different from the hole 14 of the fin 12B in which the hole 14 is drilled to serve as the fin 12A and the fin 12B. As yet another example, not only the fins 12A and the fins 12B according to the present invention, but also conventional fins having neither the projections 13 nor the holes 14 may be mixed. The number of fins 12 </ b> A provided with the protrusions 13 and the ratio of the fins 12 </ b> A provided with the protrusions for all the fins 12 are not particularly limited.

  A ventilation space 15 is formed by two disks 11 and two adjacent fins 12. Each ventilation space 15 penetrates from the inner peripheral opening 15A to the outer peripheral opening 15B. When the disk rotor 10 rotates, outside air enters from the inner circumferential opening 15A, passes through the ventilation space 15, and is discharged from the outer circumferential opening 15B. The operation of the protrusion 13 and the hole 14 at this time will be described in an embodiment described later.

  The amount of air discharged from the ventilation space 15 is affected by the rotation speed of the disk rotor 10, the position / shape / number of the protrusions 13, the angles of the fins 12 </ b> A and the protrusions 13, the size of the holes 14, and the like.

  The embodiment of the present invention described above is merely an example, and various modifications other than those described above to which various known techniques are applied are also included in the present invention.

  Using the disk rotor according to the present invention and a conventional disk rotor, the cooling performance was compared when using a low speed and when using a high speed. As an index indicating the cooling performance, the wind speed (m / s) discharged from the ventilation space was measured. Using tires with a radius of 0.355 m, wind speeds at 100 km / h, 125 km / h, 150 km / h, 175 km / h, 200 km / h, 225 km / h, 250 km / h, 275 km / h, 300 km / h (m / s) ) Were measured respectively.

  FIG. 3 is a graph showing the measurement results. It was shown that the disk rotor according to the present invention has a higher wind speed and better cooling performance than the conventional disk rotor when using at a low speed of 100 km / h to 200 km / h. On the other hand, it was shown that when the high rotation speed of 225 km / h to 300 km / h was used, the disk rotor according to the present invention was slower in wind speed and inferior in cooling performance than the conventional disk rotor.

  When using at a high speed, a large amount of air tends to flow in from the inner peripheral side of the ventilation space. However, since the air that has flowed in collides with the protrusions of the fins, the air cannot smoothly pass through the ventilation space. The air flow is disturbed by bypassing the protrusion or flowing into the adjacent ventilation space through the hole of the adjacent fin. As a result, the amount of air discharged from the outer peripheral side of the ventilation space is smaller than that of fins without protrusions or holes, and cooling performance is reduced.

  When using at low speeds, the amount of air trying to flow in from the inner periphery of the ventilation space is small, so that the air flow is not disturbed by the protrusions and holes, so that the cooling performance equivalent to or better than the conventional one can be secured. .

  From this result, it was shown that the disk rotor of the present invention exhibits sufficient cooling performance at the time of low rotation use, but hardly causes overcooling at the time of high rotation use.

10, 100: Ventilated disc rotor 11, 111: Disc 12, 12A, 12B, 112: Fin 121A: Fin first surface 13: Protrusion 14: Hole 15, 115: Ventilation 15A, 115A: Inner peripheral side opening 15B, 115B: Outer peripheral side opening 20: Axle X: Rotation direction α: Angle between fin and protrusion

Claims (3)

Two ring-shaped discs (11) arranged opposite each other at an interval;
A number of fins (12) integrally connected to the opposing surfaces of the two disks (11) and extending substantially radially;
A ventilated disc rotor (10) for a vehicle disc brake, comprising: a plurality of ventilation spaces (15) surrounded by the two discs (11) and two adjacent fins (12). ,
Protrusions (13) are provided on at least some of the fins (12A),
Another fin (12B) adjacent to the side having the projection (13) of the fin (12A) provided with the projection (13) has a hole (14) at a position facing the projection (13). Is characterized by being perforated,
Disc rotor.   2. The disk rotor according to claim 1, wherein the protrusion is provided at at least one of a position close to an inner peripheral side and an outer peripheral side of the fin. 3. The disk rotor according to claim 1, wherein one or more of the protrusions (13) are provided for one of the fins (12 </ b> A).