JP7696551B2 - Brake disc and manufacturing method thereof - Google Patents

Description

The present invention relates to a brake disc that is attached to the axle of a vehicle and has brake pads pressed against it to brake the vehicle, and a method for manufacturing the same.

Disc brake devices equipped with brake discs and brake pads have become widespread as braking devices that are installed on vehicles such as passenger cars and motorcycles to brake the vehicle. Such disc brake devices are configured so that brake discs are attached to the wheels of the vehicle so that they can rotate together, and braking force is obtained by pressing the brake pads against the brake discs.

As disclosed in Patent Document 1, for example, such brake discs have drainage holes that penetrate the disc at multiple locations in the area pressed by the brake pad. These drainage holes are formed, for example, by a hole-making device such as a punching machine, and are considered to be capable of improving heat dissipation by increasing the surface area and reducing the weight of the brake disc.

JP 2005-48787 A

However, while conventional brake discs can improve heat dissipation by using drainage holes, there has been a demand for even greater heat dissipation in recent years, which has led the applicant to thoroughly consider the shape of the drainage holes. Note that this type of heat dissipation measure using drainage holes is not limited to floating-type brake discs in which the bracket section and the disc section are separate, but is also required in so-called solid-type brake discs in which the section attached to the vehicle axle and the section against which the brake pads are pressed are integrated.

The present invention was made in consideration of these circumstances, and aims to provide a brake disc and a manufacturing method thereof that can further improve the heat dissipation effect.

The invention described in claim 1 is a brake disc that is attached to the axle of a vehicle and is used to brake the vehicle when brake pads are pressed against it, and is characterized in that a plurality of drain holes are formed in a predetermined circumferential area extending from one surface to the other surface, and the drain holes are positioned so that the openings formed in one surface and the openings formed in the other surface are offset at least in the radial direction of the disc , and a center line connecting the center positions of the openings on the one surface and the openings on the other surface extends in a direction intersecting the rotation axis of the disc .

The invention according to claim 2 is the brake disc according to claim 1 , characterized in that the drain hole is formed with the center line inclined at an angle of 10 to 30 degrees with respect to the rotation axis.

The invention described in claim 3 is characterized in that, in the brake disc described in claim 1 or claim 2, it is configured to have a bracket portion attached to the vehicle axle, a disc portion against which the brake pads are pressed, and connecting means for connecting the bracket portion and the disc portion so that they can move relative to each other, and the water drain hole is formed in the disc portion.

The invention described in claim 4 is a manufacturing method for a brake disc that is attached to an axle of a vehicle and has brake pads pressed against it to brake the vehicle, the method comprising the steps of placing a blank on a die while inclining it at a predetermined angle and lowering a punch vertically relative to the blank to perform hole punching, or placing the blank horizontally on the die and lowering a punch while inclining it at a predetermined angle relative to the blank to perform hole punching, thereby forming drainage holes that penetrate the disc at multiple locations in the pressing area of the brake pad, the drainage holes being positioned so that an opening formed on one surface and an opening formed on the other surface are offset at least in the radial direction of the disc, and a center line connecting the center positions of the openings on the one surface and the center positions of the openings on the other surface extends in a direction intersecting the rotation axis of the disc .

The invention as set forth in claim 5 is the method for manufacturing a brake disc as set forth in claim 4 , characterized in that the mounting surface of the die or the punch is inclined at a predetermined angle.

According to the invention of claim 1, a plurality of drain holes penetrating from one surface to the other surface are formed in a predetermined region around the circumference, and the drain holes are positioned so that the openings formed on one surface and the openings formed on the other surface are offset at least in the radial direction of the disk , and a center line connecting the center positions of the openings on one surface and the center positions of the openings on the other surface is extended in a direction intersecting with the rotation axis of the disk , thereby further improving the heat dissipation effect.

According to the second aspect of the present invention, the drain hole is formed with its center line inclined at an angle of 10 to 30 degrees with respect to the rotation axis, so that the heat dissipation effect can be further improved.

According to the invention of claim 3 , the brake disc is configured to have a bracket portion attached to the vehicle axle, a disc portion against which the brake pads are pressed, and connecting means for connecting the bracket portion and the disc portion so that they can move relative to each other, and the drain hole is formed in the disc portion, thereby improving the heat dissipation effect of a floating type brake disc in which the bracket portion and the disc portion are separated.

According to the invention of claim 4 , a blank is placed on a die while being inclined at a predetermined angle, and a punch is lowered vertically relative to the blank to perform hole punching, or the blank is placed horizontally on the die and a punch is lowered relative to the blank while being inclined at a predetermined angle to perform hole punching, thereby forming drainage holes that penetrate the disc at multiple locations in the pressing area of the brake pad, and the drainage holes are positioned so that the openings formed on one surface and the openings formed on the other surface are offset at least in the radial direction of the disc, and the center line connecting the center positions of the openings on the one surface and the center positions of the openings on the other surface extend in a direction intersecting with the rotation axis of the disc , so that a brake disc with improved heat dissipation effect can be easily manufactured.

According to the invention of claim 5 , since the mounting surface of the die or the punch is inclined at a predetermined angle, a brake disc having an improved heat dissipation effect can be easily and reliably manufactured.

FIG. 1 is a perspective view showing a brake disc according to an embodiment of the present invention; FIG. 2 is a front view showing the positional relationship between the brake disc and the brake pads. FIG. 1 is a schematic cross-sectional view showing a drain hole in the brake disc; FIG. 4 is a plan view showing a drain hole in the brake disc; FIG. 11 is a front view showing the positional relationship between a brake disc and a brake pad according to another embodiment of the present invention; FIG. 1 is a schematic cross-sectional view showing a drain hole in the brake disc; FIG. 4 is a plan view showing a drain hole in the brake disc; FIG. 3 is a cross-sectional view showing a brake pad applied to the brake disc. A graph showing the relationship between the inclination angle of the drainage hole and the disc temperature in the brake disc according to the embodiment of the present invention. A graph showing the relationship between the inclination angle of the drainage hole and the disc temperature in a brake disc according to another embodiment of the present invention. FIG. 1 is a schematic diagram showing a drilling device for manufacturing a brake disc according to an embodiment of the present invention; FIG. 1 is a schematic diagram showing another drilling device for manufacturing a brake disc according to an embodiment of the present invention;

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
The brake disc according to this embodiment is attached to the wheel of a vehicle such as a motorcycle so as to be able to rotate integrally with the wheel, and is made of a member for obtaining a braking force by pressing brake pads, and as shown in FIGS. 1 and 2 , is configured with a bracket portion 2, a disc portion 3, and connecting means 4.

The bracket portion 2 is obtained by pressing a metal plate material such as an aluminum alloy, and has a number of mounting holes 2a formed at predetermined positions. Fastening means such as bolts are inserted through the mounting holes 2a to secure the brake disc 1 to a wheel (not shown) of a vehicle such as a motorcycle. The disc portion 3 is connected to the outer periphery of the bracket portion 2 by connecting means 4 (floating pins), forming a disc-shaped brake disc 1 as a whole.

The disk portion 3 is obtained by pressing a metal plate material such as stainless steel into a generally circular shape, and has multiple drainage holes 3a formed at multiple locations in a predetermined area (the area pressed by the brake pad 5) in the circumferential direction. These drainage holes 3a consist of through holes that penetrate from one surface Sa of the disk portion 3 to the other surface Sb, and are formed by a perforation process such as punching, and are intended to improve heat dissipation by increasing the surface area and reduce the weight of the brake disk 1.

The disk portion 3 rotates around the disk rotation axis X as the vehicle travels, and brake pads 5 (see Figs. 2 and 8) are pressed against one surface Sa and the other surface Sb of the disk portion 3 to apply braking. Note that it is preferable that one surface Sa and the other surface Sb of the disk portion 3 are subjected to a surface treatment, such as induction hardening, to improve wear resistance.

The brake pads 5 applied to this embodiment are made of a specific friction material and are formed on a pair of pistons 7 held by a caliper 6, as shown in FIG. 8. When the driver operates an operating means such as a brake lever, brake fluid flows through a flow path b to displace the pistons 7, and the brake pads 5 are pressed against one surface Sa and the other surface Sb of the disk portion 3 that rotates together with the wheel, causing them to slide, thereby obtaining a braking force.

In this embodiment, an opposed piston type having a pair of pistons 7 is used, but other types (for example, a type in which the pistons are disposed on only one side of either one surface Sa or the other surface Sb of the brake disc 1, and the caliper 6 itself is displaced to the opposite side by the reaction force of the force pressing the brake pad 5, and the brake pad 5 on the side without the piston 7 is pressed against the brake disc 1) may also be used.

As shown in Figures 3 and 4, the drain hole 3a according to this embodiment has an opening 3aa formed on one surface Sa and an opening 3ab formed on the other surface Sb that are offset (displaced) at least in the radial direction H of the disk. In other words, the drain hole 3a is formed at a predetermined angle toward the rotation axis X, and the opening 3aa and the opening 3ab are offset.

In particular, the drain hole 3a according to this embodiment is arranged such that the center line C connecting the center position of the opening 3aa on one surface Sa and the center position of the opening 3ab on the other surface Sb extends in a direction intersecting with the rotation axis X of the disk. That is, the drain hole 3a according to this embodiment is such that the opening 3aa formed on one surface Sa and the opening 3ab formed on the other surface Sb are offset only in the radial direction H of the disk, and are not offset in the circumferential direction Y of the disk (inclination angle β in the circumferential direction Y = 0).

The drain hole 3a according to this embodiment is formed with a center line C inclined at an angle α of 10 to 30° with respect to the rotation axis X. In this way, the drain hole 3a has its center axis C inclined only in the radial direction H by an angle α, and by setting the inclination angle α to 10 to 30°, as shown in FIG. 9, the disk temperature can be reduced, and the heat dissipation effect is improved compared to the conventional method.

More specifically, in the case of a brake disc having a drain hole 3a in which the center axis C extends perpendicularly (i.e., is not inclined) to the surface (one surface Sa or the other surface Sb) as in the conventional case, when the temperature of a brake disc 1 having a drain hole 3a in which the center line C is inclined at an angle α of 10 to 30 degrees to the rotation axis X is measured in an operating environment of approximately 253°C, the results are as shown in Figure 9.

Accordingly, according to FIG. 9, a brake disc 1 having drainage holes 3a with a center line C inclined at an angle α of 10 to 30° with respect to the rotation axis X reduces the disc temperature and improves the heat dissipation effect compared to conventional brake discs, and it can be seen that the disc temperature is lowest and the heat dissipation effect is greatest when the inclination angle α is 20° in particular.

Next, another embodiment of the present invention will be described.
The brake disc according to this embodiment is a member that is attached to the wheel of a vehicle such as a motorcycle so as to be rotatable integrally with the wheel, and that obtains a braking force when brake pads are pressed against it, and as shown in Fig. 5, is configured to include a bracket portion 2, a disc portion 3, and a connecting means 4. Note that detailed explanations of the same components as those in the previous embodiment will be omitted.

As shown in Figures 6 and 7, the drain hole 3a according to this embodiment has an opening 3aa formed on one surface Sa and an opening 3ab formed on the other surface Sb that are offset (displaced) at least in both the radial direction H and the circumferential direction Y of the disk. In other words, the drain hole 3a is formed with its central axis C inclined at a predetermined angle in a direction that does not intersect with the rotation axis X, and the opening 3aa and the opening 3ab are offset.

Specifically, the drain hole 3a according to this embodiment is formed so that the center line C connecting the center position of the opening 3aa formed on one surface Sa and the center position of the opening 3ab formed on the other surface Sb does not intersect with the rotation axis X (twisted positional relationship), and is inclined at an angle α and at an angle β in the circumferential direction Y (strictly speaking, in the tangent direction of the opening 3aa or opening 3ab).

The drain hole 3a according to this embodiment is formed with its central axis C inclined at 30° (α=30) with respect to the rotation axis X and at an angle β with respect to the circumferential direction Y. In this way, the drain hole 3a is formed with its central axis C inclined at 30° (angle α) with respect to the radial direction H and at an angle β with respect to the circumferential direction Y, so that as shown in FIG. 10, the disk temperature can be reduced and the heat dissipation effect is improved compared to the conventional art.

More specifically, in the case of a brake disc having a drain hole 3a in which the central axis C extends perpendicularly (i.e., is not inclined) to the surface (one surface Sa or the other surface Sb) as in the conventional case, when the temperature of a brake disc 1 having drain holes 3a inclined by an angle β in the circumferential direction Y and an inclination angle α in the radial direction H, which is in a usage environment of approximately 253°C, was measured, the results are as shown in Figure 10.

According to FIG. 10, therefore, a brake disc 1 having drain holes 3a whose central axis C is inclined by 30° (angle α) in the radial direction H and inclined by an angle β in the circumferential direction Y reduces the disc temperature and improves the heat dissipation effect compared to conventional brake discs, and it can be seen that in particular, when the inclination angle β is 0° (i.e., the inclination angle β with respect to the circumferential direction Y is 0°), the disc temperature is the lowest and the heat dissipation effect is the highest.

Next, a method for manufacturing the brake disc 1 according to this embodiment will be described.
As shown in Figure 11, the brake disc 1 of this embodiment is made by placing a blank B on a die D while tilting it at a predetermined angle γ, and then lowering a punch P vertically onto the blank B to perform hole punching, thereby forming drainage holes 3a that pass through the disc at multiple locations in the pressing area of the brake pad 5.

In this embodiment, the mounting surface Da of the die D is inclined at a predetermined angle γ. This allows the formation of a drain hole 3a in which the opening 3aa formed on one surface Sa and the opening 3ab formed on the other surface Sb are offset at least in the radial direction H of the disk. By arbitrarily changing the position of the punch P relative to the blank B, the drain hole 3a can be made to have any inclination angle.

Also, as shown in FIG. 12, a blank B may be placed horizontally on a die D, and a punch P may be lowered while tilting it at a predetermined angle γ relative to the blank B to perform the drilling process, thereby forming drainage holes 3a penetrating the disc at multiple locations in the pressing area of the brake pad 5. Even in this case, it is possible to form drainage holes 3a in which the opening 3aa formed on one surface Sa and the opening 3ab formed on the other surface Sb are offset at least in the radial direction H of the disc.

According to the above embodiment, multiple drain holes 3a are formed in a predetermined area in the circumferential direction, penetrating from one surface Sa to the other surface Sb, and the drain holes 3a are positioned so that the opening 3aa formed on one surface Sa and the opening 3ab formed on the other surface Sb are offset at least in the radial direction H of the disk, thereby further improving the heat dissipation effect.

In particular, the drainage holes 3a are formed so that the center line C connecting the center position of the opening 3aa on one surface Sa and the center position of the opening 3ab on the other surface Sb extends in a direction intersecting with the rotation axis X of the disk, and the center line C is inclined at an angle of 10 to 30 degrees with respect to the direction perpendicular to the disk surface, thereby further improving the heat dissipation effect. Also, if the drainage holes 3a are formed so that the opening 3aa formed on one surface Sa and the opening 3ab formed on the other surface Sb are offset in the radial direction H and circumferential direction Y of the disk, a brake disk 1 with any desired heat dissipation effect can be easily obtained.

Furthermore, the applied brake disc is configured with a bracket portion 2 that is attached to the vehicle axle, a disc portion 3 against which a brake pad 5 is pressed, and a connecting means 4 that connects the bracket portion 2 and the disc portion 3 so that they can move relative to each other, and the drainage hole 3a is formed in the disc portion 3, so that the heat dissipation effect of the floating type brake disc 1 in which the bracket portion 2 and the disc portion 3 are separate can be improved.

Furthermore, by placing the blank B on the die D while tilting it at a predetermined angle γ and lowering the punch P vertically relative to the blank B to perform the hole punching process, or by placing the blank B on the die D and lowering the punch P while tilting it at a predetermined angle γ relative to the blank B to perform the hole punching process, drainage holes 3a penetrating the disc are formed at multiple locations in the pressing area of the brake pad 5, and the drainage holes 3a are positioned such that the openings 3aa formed on one surface Sa and the openings 3ab formed on the other surface Sb are offset at least in the radial direction H of the disc, so that the brake disc 1 with improved heat dissipation effect can be easily manufactured. In particular, if the mounting surface Da of the die D is tilted at a predetermined angle, the brake disc 1 with improved heat dissipation effect can be easily and reliably manufactured.

Although the present embodiment has been described above, the present invention is not limited to this embodiment. For example, instead of a floating type brake disc 1 in which the bracket portion 2 and the disc portion 3 are separate, the present invention may be applied to an integrated brake disc (so-called solid type). Also, instead of a hole-making processing device with a punch P, the drainage holes 3a may be formed by other processing devices such as a laser processing machine.

As long as a brake disc has multiple drainage holes formed in a circumferentially specific region that penetrate from one surface to the other surface, and the drainage holes are positioned such that the openings formed on one surface and the openings formed on the other surface are offset at least in the radial direction of the disc, the drainage holes may have other shapes or functions.

Reference Signs List 1 Brake disc 2 Bracket portion 2a Mounting hole 3 Disc portion 3a Drain hole 3aa Opening on one surface 3ab Opening on the other surface 4 Connecting means 5 Brake pad 6 Caliper 7 Piston Sa One surface Sb Other surface X Rotation axis Y Circumferential direction H Radial direction C Center line B Blank material D Die Da Mounting surface P Punch

Claims (5)

A brake disc attached to an axle of a vehicle, the brake pads being pressed against the brake disc to brake the vehicle,
A brake disc characterized in that a plurality of drain holes are formed in a predetermined circumferential region, penetrating from one surface to the other surface, and the drain holes are positioned so that an opening formed in one surface and an opening formed in the other surface are offset at least in the radial direction of the disc , and a center line connecting the center position of the opening on one surface and the center position of the opening on the other surface extends in a direction intersecting the rotation axis of the disc . 2. The brake disc according to claim 1 , wherein the drain hole is formed such that the center line is inclined at an angle of 10 to 30 degrees with respect to the rotation axis. 3. A brake disc according to claim 1 or claim 2, characterized in that it is configured to have a bracket portion attached to an axle of a vehicle, a disc portion against which the brake pads are pressed, and connecting means for connecting the bracket portion and the disc portion so that they can move relative to each other, and the drainage hole is formed in the disc portion. A method for manufacturing a brake disc that is attached to an axle of a vehicle and has brake pads pressed thereon to brake the vehicle, comprising the steps of:
A method for manufacturing a brake disc, comprising the steps of: placing a blank on a die while tilting it at a predetermined angle; and lowering a punch vertically relative to the blank to perform hole punching; or placing the blank horizontally on the die and lowering a punch while tilting it at a predetermined angle relative to the blank to perform hole punching; thereby forming drainage holes that penetrate the disc at multiple locations in the pressing area of the brake pad, wherein the drainage holes are positioned so that an opening formed on one surface and an opening formed on the other surface are offset at least in the radial direction of the disc , and a center line connecting the center positions of the openings on the one surface and the center positions of the openings on the other surface extends in a direction intersecting the rotation axis of the disc . 5. The method for manufacturing a brake disc according to claim 4 , wherein the mounting surface of the die or the punch is inclined at a predetermined angle.

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