GB2076090A

GB2076090A - Disk brake rotor

Info

Publication number: GB2076090A
Application number: GB8115554A
Authority: GB
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1980-05-21
Filing date: 1981-05-20
Publication date: 1981-11-25
Also published as: JPS56164237A; DE3120104A1; DE3120104C2; FR2483029A1

Abstract

A ventilated disk brake rotor (1) includes first and second disks (2, 3) having the respective engaging walls (2a, 3a) on the outer sides thereof and an opening (5) formed in the central portion thereof, a plurality of main ribs (4) extending between the disks (2, 3) in a radial direction of the rotor, and a plurality of auxiliary ribs (10) extending between the disks (2, 3) in the circumferential direction of the rotor and one auxiliary rib (10) laps partially in the radial direction over the main rib (4) and/or auxiliary rib adjacent thereto in such a manner that the rigidity or strength of the rotor is increased. As shown in Figure 2 each main rib (4) is joined to an auxiliary rib (10) to form a T-shape, other figures show L-shaped, Z-shaped, I-shaped rib combinations. The ribs may be formed separately. In Figure 4, the auxiliary ribs (10) are formed at separate portions of the rotor (1) in groups (G). <IMAGE>

Description

SPECIFICATION Disk brake rotor This invention relates to a ventilation type disk brake rotor.

A ventilated disk brake is used to brake a rotating member such as a rotor rotating in response to rotation of a wheel or wheels by pressing it between a pair of brake pads, like in a general disk brake. The ventilated disk brake has air flow passages so that the heat generated by friction between the rotor and the brake pads can be radiated through a plurality of cooling ribs radially extending between two engaging walls of the rotor.

Figs. 1(A) and (B) show a conventional ventilated disk brake. A rotor 1 includes a pair of first and second disks 2, 3 having respective engaging walls 2a, 3a onto which a pair of brake pads (not shown) are pressed. The first and second disks 2, 3 are joined by a plurality of ribs 4 radially extending between the engaging walls 2a, 3a.

The first disk 2 has at its central portion an opening 5 through which a rotating shaft of a wheel (not shown) is inserted. Around the opening 5, a plurality of through-holes 6 are formed in the inner projecting edges of the first disk 2. An opening 7 is formed in the central portion of the second disk 3. When the wheel is rotating, air flows between the ribs 4 in response to rotation of the rotor 1 so that the heat generated by friction between the brake pads and the engaging walls 2a, 3a of the rotor 1 during braking can be radiated so as to result in the cooling thereof.

Thus, so called vapor-lock phenomenon can be prevented from occurring in the fluid which operates the brake pads.

In such a conventional disk brake rotor, however, the ribs 4 are radially arranged only in view of the air flow characteristics. As a result, the rigidity or strength in the radial directions of the engaging walls of the rotor 1 is disregarded so that the rotor 1 may vibrate when the brake pads are engaged. Therefore, the resonance phenomenon can easily occur in the rotor 1 so that braking noises take place during braking.

According to the present invention, a ventilated disk brake includes not only ribs radially extending between a pair of engaging walls of a rotor, but also a plurality of ribs arranged in the circumferential direction of the rotor so that the rigidity or strength of the rotor in the circumferential direction may be increased or improved.

Therefore, the object of the present invention is to provide a ventilated disk brake in which the defects of the prior art ventilated disk brake as above-mentioned can be eliminated to prevent brake noises from occurring to a reasonable extent.

In the accompanying drawings:- Fig. 1(A) is a schematic front view showing a conventional disk brake rotor; Fig. 1 (B) is a sectional view of the conventional disk brake rotor taken along the iine Il-lI in Fig.

1(A); Fig. 2 is a sectional view showing an essential portion of a disk brake rotor according to a preferred embodiment of the present invention; Fig. 3(A) is a sectional view showing a portion of another form of ribs according to the present invention; Fig. 3(B) shows a still another form of ribs according to the present invention; Fig. 3(C) shows a further form of ribs according to the present invention; Fig. 4 is a sectional view showing a further embodiment of the present invention; and Fig. 5 is an explanatory view showing schematically uniformly distributed resonance waves occurring in a conventional rotor.

Like or corresponding members and parts are designated by the same references as in Figs. 1(A) and (B) showing the prior art disk brake rotor.

Referring to Fig. 2, a rotor 1 includes a pair of first and second disks 2, 3 having the respective engaging walls 2a, 3a on the outer sides thereof.

Except the forms and arrangements of ribs, the rotor 1 is substantially the same as in Figs. 1(A) and (B) so that those will be not described in detail.

A plurality of main ribs 4 extend radially between the engaging walls 2a, 3a of the disks 2, 3 at the given same intervals as in the conventional disk brake rotor. In addition, a plurality of auxiliary ribs 10 are arranged between the engaging walls 2a, 3a in the circumferential direction of the rotor 1.

Although the auxiliary ribs 10 can be separately formed from the main ribs 4, it is preferable that each main rib 4 is joined at one end to the center of each auxiliary rib 10 to form a T-shape. In Fig.

2, the auxiliary ribs 10 are joined alternately to the inner and outer ends of the radially fixed main ribs 4 so that a T-shaped combination of main and auxiliary ribs 4 and 10 is adjacent to a reverse Tshaped combination of main and auxiliary ribs 4 adjacent thereto. One combination of main and auxiliary ribs is spaced from another combination of main and auxiliary ribs substantially by the same distance. Therefore, zigzag air flow passages are formed among the combinations of main and auxiliary ribs. In such an arrangement of main and auxiliary ribs, the engaging walls 2a, 3a can be increased in rigidity and strength at the inner and outer periphery thereof.

All auxiliary ribs 10 joined to the outer end of the main ribs 4 have the same length and are arranged at the same intervals with the same pitch. Also, all auxiliary ribs 10 joined to the inner end of the main ribs 4 have the same length and are arranged at the same intervals with the same pitch. As a result, the rigidity and strength of the rotor 1 is uniform at any position of the periphery thereof so that the rotor 1 is prevented from resonating with brake pads, caliper and vehicle body (not shown).

In operation, the brake pads are pressed onto the engaging walls 2a, 3a of the rotor 1 to cause the rotor 1 to vibrate, but such vibration of the rotor 1 can be remarkably decreased because of the improved rigidity and strength of the rotor 1.

Also, the characteristic frequency of the rotor 1 is designed so as to differ from that of the brake pads, caliper and vehicle body. Therefore, the natural vibration of the rotor 1 does not increase to avoid braking noise.

Figs. 3(A), (B) and (C) show three different forms of auxiliary rib-main rib combinations.

In Fig. 3(A), a main rib 4 is joined to an auxiliary rib 10 in an L-shape. An L-shaped combination of main and auxiliary ribs is adjacent to a reverse Lshaped combination of main and auxiliary ribs, continuously although only a portion thereof is shown.

In Fig. 3(B), a main rib 4 is joined to an auxiliary rib 10 in a Z-shape.

In Fig. 3(C), a main rib 4 is joined to an auxiliary rib 10 in an I-form.

Other forms of main and auxiliary ribs in combination can be employed if the main ribs are arranged in the radial directions of the rotor 1 and the auxiliary ribs are arranged in the circumferential direction of the rotor. Air must flow among such a combination of main and auxiliary ribs for the purpose of radiating heat into the atmosphere.

Also, it should be noted that, according to the present invention, at least partially, the auxiliary ribs 10 of one combination is positioned or lap in the radial direction over the main and/or auxiliary ribs of the adjacent combination thereto so that the rigidity and strength of the rotor 1 is reasonably increased and improved. It is preferable that at the whole periphery of the rotor the auxiliary ribs 10 are placed partially over the auxiliary and/or main ribs of the adjacent combination, although the present invention is not limited to such an embodiment.

Fig. 4 shows another embodiment of the present invention. The auxiliary ribs 10 arranged or extending in the circumferential direction of the rotor 1 are formed only at a plurality of separate portions of the rotor 1.

The portions in which the rigidity and strength of the rotor 1 is increased constitutes the groups G where the auxiliary ribs 10 are formed in the circumferential direction of the disks 2, 3. The groups G are spaced from each other by the distance 1. Each group G consists of three adjacent main ribs 4', 4" and three auxiliary ribs 10 joined to the respective main ribs 4', 4" in a Tform. One auxiliary rib 10 is joined at its center to the inner end of the main rib 4", and the other auxiliary ribs 10 are joined to the outer ends of the main ribs 4', 4' at both sides of the central auxiliary rib 4".

It is preferable that the groups G are placed at the same intervals along the periphery of the disks 2, 3. In Fig. 4, three main ribs 4 are arranged at the same intervals between the groups G.

In operation, the uniformly distributed resonance waves of the rotor 1 can be prevented from occurring during braking.

If the rigidity is uniform at the whole periphery of the rotor, as shown in Fig. 5, a sine curve like uniformly distributed resonance waves "e" may occur at the rotor. If such uniformly distributed resonance waves occur, then the oscillation damping performance of the rotor 1 is worsened.

As a result, the brake noises sometimes occur.

On the contrary, in the embodiment shown in Fig. 4, the rigidity and strength of the rotor 1 in its circumferential direction is not only increased but also differs at the given several points of the periphery thereof. Thus, the rotor 1 does not resonate with other members such as brake pads, caliper and vehicle body. Further, the uniformly distributed resonance waves can be prevented from occurring at the rotor 1 so that the oscillation damping performance of the rotor 1 can be increased to completely avoid braking noise.

The number of the groups G is preferably a prime number.

Each combination of main and auxiliary ribs is formed in a T-shape, in Fig. 4, but other forms of main and auxiliary ribs in combination can be used like in Figs. 3(A), (B) and (C), if the main ribs extend in the radial direction of the rotor and the auxiliary ribs extend in the circumferential direction thereof.

Claims

1. A ventilated disk brake rotor, comprising: a pair of first and second disks having the respective engaging walls on the outer sides thereof and an opening formed in the central portion thereof; a plurality of main ribs extending between the pair of first and second disks in a radial direction of the rotor; and a plurality of auxiliary ribs extending between the pair of first and second disks in the circumferential direction of the rotor, one auxiliary rib being positioned partially in the radial direction over the main rib and/or auxiliary rib adjacent thereto in such a manner that the rigidity or strength of the rotor can be increased.

2. A ventilated disk brake rotor as claimed in claim 1 , wherein the auxiliary ribs are placed only at selected portions of the whole periphery of the rotor so that the rigidity or strength of the rotor is not uniform at the periphery of the rotor.

3. A ventilated disk brake rotor as claimed in claim 1 or 2, wherein the auxiliary ribs are joined to the main ribs in a T-shape.

4. A ventilated disk brake rotor as claimed in claim 1 or 2, wherein the auxiliary ribs are joined to the main ribs in an L-shape.

5. A ventilated disk brake rotor as claimed in claim 1 or 2, wherein the auxiliary ribs are joined to the main ribs in a Z-shape.

6. A ventilated disk brake rotor as claimed in claim 1 or 2, wherein the auxiliary ribs are alternately joined to the outer and inner ends of the main ribs in a T-shape, one after another, in such a manner that air flow passage can be formed among the main and auxiliary ribs in combination.

7. A ventilated disk brake rotor substantially as described with reference to Fig. 2, or Fig. 4, or Fig.

2 as modified by Figs. 3A, or 3B, or 3C of the accompanying drawings.