JP2018021614A - Brake disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake disk with stack constitution that can advantageously obtain frictional attenuation with a simple structure and has high cooling performance.SOLUTION: A brake disk is sandwiched between two friction pads MSA and MSB to generate braking force on a wheel. The brake disk comprises a first disk which comes into slide contact with one of the two friction pads on a first slide surface, and a second disk which comes into slide contact with the other of the two friction pads on a second slide surface. The first disk has a first fin part in the form of a plurality of thin and long projection parts on a first back surface on the opposite side from the first slide surface. Further, the second disk has a second fin part which is in the form of a plurality of thin and long projection parts on a second back surface on the opposite side from the second slide surface, and mirror-symmetrical with the first fin part. "A first fin plane formed at the first fin part in parallel with the first slide plane" and "a second fin plane formed at the second fin part in parallel with the second slide surface" are fixed in plane contact.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a brake disc.

  In Patent Document 1, for the purpose of “obtaining a brake disc free of abnormal noise”, “at least two discs having different frequencies are superposed and distributed so as to give freedom to each other” Are attached to each other at a plurality of locations ”. Specifically, it is described that two discs are integrally bound by a rivet at a portion sliding with a brake pad. That is, in the brake disc described in Patent Document 1, brake squeal is reduced by friction damping.

  Patent Document 2 discloses that for the purpose of “reducing brake noise in a ventilated rotor having a ventilation hole (ventilation)”, “a rotor is formed into a plate-like body, each of which forms a sliding surface. Divide and place fins alternately on the opposite sides of each sliding surface of these plate-like bodies, attach damping materials to the tip surfaces of these fins, and join these plate-like bodies to each other with the damping materials Disc brake rotor characterized by being assembled with bolts and nuts and having ventilation formed therein. That is, in the brake disc described in Patent Document 2, brake squeal is reduced by the damping effect of the damping material.

  Patent Document 3 aims to “provide a mold structure and a casting method for avoiding product quality deterioration in casting using a center gate mold that radially pours from the axial center of the cavity for the annular member” “The mold structure is composed of at least one core 12a and at least a pair of molds 12b arranged with the core 12a interposed therebetween, and has a cavity for casting the annular member. A pouring gate 19 and a pouring channel 18 are provided in the vicinity of the shaft so that the hot water is radially diffused and cast in. The pair of molds 12b extends from the entire circumference of the outer peripheral surface to one or both of the axial directions. It has a flange portion 15 and is configured to surround the periphery of the core 12a with the flange portion 15 to prevent deformation and collapse due to expansion of the core 12a. The grooves 25, the boundary surface of the core 12a and the mold 12b, is formed on the contact surface of the flange 15, has been described is constructed "it to emit gas in the cavity to mold the outside.

  In the brake disc described in Patent Document 1, two discs are fixed by a large number of rivets at a portion in contact with a brake pad (also referred to as a “friction pad”). In this case, wear powder of the friction pad is accumulated in the rivet through-hole, so there is a concern about abnormal noise (brake squeal) caused by this wear powder. Further, since the brake disk is required to have a cooling performance, a structure having a vent hole is required.

  In consideration of the above matters, the brake disk configuration described in Patent Document 1 (referred to as “friction damping configuration”) is applied to the brake disk described in Patent Document 2 to obtain a noise suppression effect due to friction damping. Try that. However, in the configuration described in Patent Document 2, since adjacent convex portions exist, it is difficult to make the depths of the concave portions uniform by machining. Therefore, after assembly, sufficient contact between the convex portion and the concave portion is not ensured, and it is difficult to obtain the effect of friction damping.

  This will be described with reference to FIG. FIG. 6 is a partial cross-sectional view as viewed in the vertical direction with respect to the rotation axis Jwh of the disk when the concave and convex portions of the first disk D1 and the second disk D2 are brought into contact with each other so as to alternately engage with each other. When there is variation in the depth (length) of the concave portion, for example, as shown by the X portion, when the convex portion of the first disc D1 and the concave portion of the second disc D2 come into contact with each other, contact at other parts is not achieved. Be inhibited. That is, as illustrated in the Y and Z portions, a gap is generated between the convex portion and the concave portion. When the gap is filled with a damping material, the gap is not a problem.

  However, the gap becomes a problem when trying to obtain friction damping in the surface contact of two disks. This is because the larger the contact area, the greater the effect of friction damping. Therefore, even if the configuration described in Patent Document 2 (that is, the configuration in which the fins are alternately protruded) is adopted, it is difficult to make the depth of the recess uniform, so that it is difficult to obtain the effect of friction damping.

  Patent Document 3 is an example of a method for integrally casting a ventilated disk. In order to realize a ventilated structure, a core extending from the inner periphery to the outer periphery is required. To ensure the strength of the core itself, it is impossible to produce a core that is too thin. Therefore, in order to ensure the cooling performance of the brake disc, it is difficult to optimize the shape (number, width, etc.) of the vent holes (ventilated holes). That is, since there is a trade-off relationship between the core strength and the vent hole shape, a certain degree of concession is required in the vent hole shape to ensure the core strength.

  A general brake disc is desired to have highly optimized brake squealing performance and cooling performance. That is, there is a strong demand for a brake disk that has a friction damping effect and a high degree of design freedom in the shape (number, width, etc.) of the air holes.

Japanese Patent Publication No. 50-035179 JP 58-072735 A JP2013-052436A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a brake disc having a laminated structure, which can effectively obtain friction damping with a simple structure and has high cooling performance.

  The brake disk (BRD) according to the present invention is fixed to a vehicle wheel (WH) and is sandwiched between two friction pads (MSA, MSB), thereby generating a braking force on the wheel (WH). The brake disc (BRD) includes one of the two friction pads (for example, MSA), the first disc (BDA) that is in sliding contact with the first sliding surface (Maa), and the two friction pads. And the other disc (for example, MSB) and a second disc (BDB) that is in sliding contact with the second sliding surface (Mba).

  In the first brake disk (BRD) according to the present invention, the first disk (BDA) is a plurality of elongated protrusions on the first back surface (Mab) opposite to the first sliding surface (Maa). A first fin portion (Fna), and the second disk (BDB) is a plurality of elongated protrusions on a second back surface (Mbb) opposite to the second sliding surface (Mba), The first fin portion (Fna) has a second fin portion (Fnb) that is mirror-symmetrical to the first fin portion (Fna), and “the first fin portion (Fna) formed in parallel to the first sliding surface (Maa)”. The “plane (Maf)” and “the second fin plane (Mbf) formed in parallel to the second sliding surface (Mba) in the second fin portion (Fnb)” are fixed so as to be in surface contact with each other. .

  In the second brake disc (BRD) according to the present invention, the first disc (BDA) is a plurality of elongated protrusions on the first back surface (Mab) opposite to the first sliding surface (Maa). “A first fin plane (Maf) formed in parallel to the first sliding surface (Maa) in the first fin portion (Fna)” and the “second disk”. The second back surface (Mbb) which is the opposite side of the second sliding surface (Mba) of (BDB) is fixed so as to come into surface contact.

  A third brake disk (BRD) according to the present invention includes one of the two friction pads (for example, MSA) and a first disk (BDD) that is in sliding contact with the first sliding surface (Mda), The other of the two friction pads (for example, MSB), a second disk (BDE) that is in sliding contact with a second sliding surface (Mea), the first disk (BDD), and the second disk (BDE). And an intermediate disk (BDC) provided in the middle. In the brake disc (BRD) according to the present invention, two planes of the intermediate disc (BDC) are parallel, and a plurality of elongated grooves (Zma, Zmb) are formed on at least one of the two planes. Then, the first disk (BDD) and the intermediate disk (BDC) are in surface contact, and the second disk (BDE) and the intermediate disk (BDC) are fixed in surface contact.

  In the processing of the disk, it is relatively difficult to ensure the processing accuracy (particularly the depth of the groove) of the concave portion, and it is relatively easy to ensure the processing accuracy of the convex portion. According to the above configuration, in assembling the two disks, it is not adopted that the groove part (concave part) of one disk and the fin part (convex part) of the other disk are abutted and assembled. The tip flat surface of the convex portion or the like is assembled in surface contact with the tip flat surface of the mirror-symmetric convex portion or a flat plate. For this reason, a sufficient contact area is ensured and a substantially uniform contact state is obtained. The laminated structure (friction damping structure) of the brake disk is simplified, and a sufficient friction damping effect can be ensured.

It is the front view for demonstrating 1st Embodiment of the brake disc BRD which concerns on this invention, and sectional drawing. It is the front view for demonstrating the shape of the 1st disk BDA, and sectional drawing. It is sectional drawing for demonstrating the modification of 1st Embodiment of the brake disc BRD which concerns on this invention. It is the front view for demonstrating 2nd Embodiment of the brake disc BRD which concerns on this invention, and sectional drawing. It is the front view and partial side view for demonstrating the intermediate | middle disc BDC. It is a fragmentary sectional view for demonstrating the subject in the case of trying to obtain friction attenuation | damping by applying a prior art.

<First embodiment of brake disc BRD according to the present invention>
A first embodiment of a brake disc BRD according to the present invention will be described with reference to a front view and a cross-sectional view of FIG. In the following description, constituent members and parts to which the same symbol is attached exhibit the same function. Therefore, duplicate description may be omitted.

  The brake disc BRD is a friction disc of a disc-type braking device that is employed for braking the wheel WH in the vehicle. The brake disc BRD is sandwiched between the two friction pads MSA and MSB and fixed to the wheel WH so as to rotate together.

  During braking, the brake disc BRD receives a pressing force so as to be sandwiched between the first and second friction pads MSA and MSB. Due to the pressing force at this time, a frictional force is generated when the first and second friction pads MSA, MSB and the brake disc BRD slide. Due to this frictional force, the wheel WH generates a braking force. The brake disc BRD includes a first disc BDA, a second disc BDB, a hat member HTB, and a fastening member TKB.

  With reference to AA sectional drawing, the shape of each member and attachment are demonstrated. The first disc BDA is a disc member formed in an annular shape. The first disc BDA is in sliding contact with the first friction pad MSA (inner side friction pad) at the outer peripheral portion of the first sliding surface Maa (inner side plane) so that the wheel WH (tire) generates a braking force. . In the first sliding surface Maa, the area sliding with the first friction pad MSA is the “sliding range” of the first disk BDA. A plurality of fastening holes Ata are provided in the inner peripheral portion of the first disk BDA so that the first disk BDA is assembled to the hat member HTB. Here, the fastening hole Ata is a through hole.

  An elongated protrusion Fna (referred to as “first fin portion”) is provided on the first back surface Mab of the first disk BDA. The first back surface Mab (outer side plane) is a plane opposite to the first sliding surface Maa (back side). The cross-sectional shape of the first fin portion Fna is a convex shape, and a flat surface Maf (referred to as a “first fin plane”) is formed at the tip of the protrusion.

  Similar to the first disk BDA, the second disk BDB is a thin plate-shaped member formed in an annular shape. The second disc BDB is in sliding contact with the second friction pad MSB (outer side friction pad) at the outer peripheral portion of the second sliding surface Mba (outer side plane). In the second sliding surface Mba, an area that slides with the second friction pad MSB is a “sliding range” of the second disk BDB. Similar to the first disk BDA, a plurality of fastening holes Atb (through holes) are provided in the inner peripheral portion of the second disk BDB so that the second disk BDB is assembled to the hat member HTB.

  Also in the second disk BDB, an elongated protrusion (second fin portion) Fnb is provided on a plane (inner side plane, second back surface Mbb) opposite to the second sliding surface Mba (back side). The cross-sectional shape of the second fin portion Fnb is a convex shape, and a flat surface (second fin plane) Mbf is formed at the tip of the protrusion. Here, the first fin portion Fna and the second fin portion Fnb (thus, the first fin plane Maf and the second fin plane Mbf) are mirror-symmetric.

  “Mirror symmetry” is also called “mirror symmetry” and means that a mirror image of a certain mirror surface matches the original figure. For example, when the shape of the plane figure is mirror-symmetric (mirror image symmetry), the plane figure shape is line-symmetric.

  The hat member HTB is a bottomed cylindrical member extending in the rotation axis direction Jwh of the brake disc (same as the rotation axis of the wheel WH). Hat member HTB has flange portion Fln on outer peripheral portion Mht. A hub unit HUB is provided inside the cylinder of the hat member HTB. A plurality of attachment holes Awh (through holes) are provided at the bottom of the hat member HTB. The hub bolt HBL of the hub unit HUB passes through the mounting hole Awh, and is tightened with the wheel nut WNT with the wheel disc portion of the wheel WH interposed therebetween. That is, the hub unit HUB, the hat member HTB, and the wheel WH are integrally coupled by the hub bolt HBL and the wheel nut WNT. For example, an aluminum alloy can be adopted as the hat member HTB.

  The inner peripheral surface Mha of the first disc BDA and the inner peripheral surface Mhb of the second disc BDB are fitted to the cylindrical outer peripheral surface Mht of the hat member HTB with a slight gap. When the fastening member TKB is fastened together, the outer peripheral surface Mht of the hat member HTB and the inner peripheral surfaces Mha and Mhb of the first and second discs BDA and BDB are fitted together so that positioning can be easily performed.

  The flange portion Fln of the hat member HTB is provided with a plurality of fastening holes Ath (through holes) so that the first disk BDA and the second disk BDB can be assembled. The fastening member TKB passes through the fastening hole Ath of the hat member HTB, the fastening hole Ata of the first disk BDA, and the fastening hole Atb of the second disk BDB. And these three members HTB, BDA, and BDB are fastened by the fastening member TKB at a site on the inner peripheral side (side closer to the rotation axis Jwh) than the sliding range. Specifically, the fastening member TKB is a caulking member (for example, a rivet or a grommet), and its end is plastically deformed to be fastened together and fixed.

  In the fixing by the fastening member TKB, the first fin portion Fna of the first disc BDA and the second fin portion Fnb of the second disc BDB are abutted on the same plane Mms. That is, the first fin plane Maf and the second fin plane Mbf, which are in a mirror-surface relationship, are fixed so that their positions coincide with each other (see the section BB). Here, the contact portion between the first fin plane Maf and the second fin plane Mbf is referred to as “contact surface Mms”.

  The brake disc BRD is formed as a single disc by superimposing two discs (first disc BDA and second disc BDB) and fixing them by a hat member HTB and a fastening member TKB. The hole diameters of the fastening holes Ath, Ata, Atb are slightly larger than the diameter of the fastening member TKB in the through portion. For this reason, the first disk BDA and the second disk BDB are in a state in which a minute displacement can be performed with respect to the hat member HTB while being fixed in the disk rotation axis Jwh direction. Therefore, friction damping is obtained by a minute mutual displacement (minute displacement) in contact (contact surface Mms) between the first fin plane Maf and the second fin plane Mbf. For the first and second disks BDA and BDB, cast iron having high vibration damping can be adopted.

  The “small displacement” is a displacement larger than the amplitude of the brake squeal when the brake squeal occurs. The brake squeal is several tens μm at most. Therefore, the minute displacement is within the range of looseness during assembly or elastic deformation of the member. When a brake squeal occurs, the first disk BDA and the second disk BDB are rubbed against each other in an arbitrary direction on the contact surface Mms. Since friction exists on the contact surface Mms, the brake squeal is reduced by frictional damping that occurs when the friction is caused.

  A gap formed by the first fin portion Fna and the second fin portion Fnb is configured as a heat radiating air hole Avn. The inner peripheral portion and the outer peripheral portion of the brake disc BRD are connected through the vent hole Avn. A ventilated brake disc is formed by the vent hole Avn.

  The wheel WH, the hub unit HUB, the hat member HTB, the first disk BDA, and the second disk BDB are fixed coaxially. Accordingly, the disk rotation axis Jwh is the rotation axis of the wheel WH, the hub unit HUB, the hat member HTB, the first disk BDA, and the second disk BDB.

  In processing a disk, it is relatively difficult to ensure the processing accuracy (particularly the depth of the groove) of the recess. Therefore, in assembling the two disks BDA and BDB, the abutment between the groove part (concave part) of one disk and the fin part (convex part) of the other disk is avoided. As described with reference to FIG. 6, since the surface contact of the first and second disks BDA and BDB is hindered, the disk assembly combining the uneven portions is not employed.

  The tip portions of the first and second fin portions Fna and Fnb are processed to form the first and second fin planes Maf and Mbf. Then, the first fin plane Maf and the second fin plane Mbf are brought into contact with each other, and the brake disc BRD is assembled. Here, the first fin plane Maf and the second fin plane Mbf are in a mirror-symmetrical relationship (that is, line symmetry) in the contact surface shape.

  It is relatively easy to ensure the processing accuracy of the convex portion as compared with the processing of the concave portion. For this reason, since it is assembled so that the first fin plane Maf of the first fin portion Fna and the second fin plane Mbf of the second fin portion Fnb match, a sufficient contact area is ensured and substantially uniform. A contact state (for example, surface pressure) is obtained. As a result, a sufficient friction damping effect can be ensured.

  During non-braking when the wheel WH does not generate braking force, the first disk BDA and the second disk BDB do not move relative to each other and rotate completely together. In addition, even during braking, if no brake squeal has occurred, the relative displacement between the first disk BDA and the second disk BDB does not occur. However, during braking, if a brake squeal occurs in any one of the first disk BDA and the second disk BDB, a periodic relative to the disk that does not generate the brake squeal. Displacement occurs. A frictional force is generated between the first fin plane Maf and the second fin plane Mbf by the relative movement of the first disk BDA and the second disk BDB. Due to this frictional force, the generated brake squeal can be suppressed. In particular, since the contact surface Mms has a large area, large frictional damping acts, and the squeal vibration in the direction perpendicular to the first and second sliding surfaces Maa and Mba is effectively suppressed. .

  However, it has a vibration suppression effect against squeal vibration (that is, motion vibration parallel to the sliding surfaces Maa and Mba) that does not involve the relative movement (small displacement) of the first and second sliding surfaces Maa and Mba. It can be lower. In order to cope with such a case, the heights of the first and second fin portions Fna and Fnb (that is, the height of the protrusions forming the vent hole Avn is approximately “1: 2”, for example) , Disc thickness) may be provided. Due to this dimensional difference, the natural frequencies of the first disk BDA and the second disk BDB are different, so that a vibration suppressing effect can be obtained even for squeal vibrations parallel to the sliding surfaces Maa and Mba.

  Further, the first disk BDA and the second disk BDB are employed having different vibration characteristics (for example, natural frequency) so that the brake noise does not occur at the same time. Therefore, when a brake squeal occurs in one of the first disk BDA and the second disk BDB, the vibration is amplified by the other disk (that is, the resonance phenomenon) is avoided. .

  The whole of the two discs BDA, BDB can be made mirror-symmetrical. Even in the case of the left and right wheels WH having different rotation directions, the brake disk BRD can be configured without increasing the number of parts by combining the two mirror-symmetric disks BDA and BDB. In addition, when the first and second disks BDA and BDB are mirror-symmetric, the difference in cooling performance between the first and second disks BDA and BDB is slight.

<First disc BDA>
The first disk BDA will be described with reference to the front view and cross-sectional view of FIG. In the first disc BDA, the first fin portion Fna and the boss portion Bsa protrude from the surface Mab (back surface) opposite to the first sliding surface Maa. A fastening hole Ata is opened in the boss portion Bsa.

  The heights of the fin part Fna and the boss part Bsa (that is, the distance from the first sliding surface Maa) are aligned by machining. For example, after the first disk BDA is cast, the first fin plane Maf and the boss plane Mbs are in the same plane parallel to the first sliding surface Maa. It is processed by at least one method.

  Similar to the first disk BDA, the second disk BDB is also finished by machining (at least one of cutting, grinding, and polishing) after being cast. It is relatively easy to form the first and second fin planes Maf and Mbf parallel to the first and second sliding surfaces Maa and Mba by machining. .

  The first fin portion Fna has a spiral shape (a so-called curve vane type). Specifically, the first fin portion Fna extends in the radial direction at the inner peripheral portion of the first disk BDA, and gradually approaches the forward rotation direction of the brake disc BRD (corresponding to the vehicle forward direction) as it approaches the outer peripheral portion. ) Tilt in the opposite direction to Dfw (see front view). By rotating the spiral first fin portion Fna, the brake disc BRD can smoothly discharge air from the central portion to the outer peripheral portion, and the cooling performance can be improved. The second fin portion Fnb of the second disc BDB is formed in mirror symmetry (mirror symmetry) with the first fin portion Fna so as to coincide with the first fin portion Fna. Therefore, the first fin plane Maf of the first fin portion Fna and the second fin plane Mbf of the second fin portion Fnb are in a line-symmetric relationship in the planar shape.

  As the first fin portion Fna, a straight type having a linear shape (that is, a shape extended in the radial direction without being inclined in the normal rotation direction Dfw) can be adopted instead of the curve vane type fin. The shape of the straight first fin portion Fna is also determined so as to match the second fin portion Fnb.

  In order to manufacture the first and second fin portions Fna and Fnb protruding from the first and second rear surfaces Mab and Mbb by casting, a core is not necessary. This is because the air holes Avn are cast as grooves provided on the back surfaces (back surfaces) Mab and Mbb of the sliding surfaces Maa and Mba. The “core” is a sand mold that fits into a mold as a portion corresponding to a cavity when a casting having a cavity is manufactured.

  Since the core is not required, the casting efficiency is improved, and it is not necessary to consider the core strength in casting (in other words, the core strength and the shapes of the first and second fin portions Fna and Fnb). There is no trade-off with). For this reason, the shapes of the fin portions Fna and Fnb can be optimized only for cooling performance. For example, a ventilation hole Avn having a finer shape can be formed, and the cooling performance can be improved.

  When the temperature difference between the first and second sliding surfaces Maa and Mba and the first and second fin portions Fna and Fnb increases due to heat generated during braking, the sliding surfaces Maa and Mba are thermally deformed into a convex state. It is possible that In order to suppress this thermal deformation, concentric cuts (not shown) may be provided in the first and second fin portions Fna and Fnb. The cut can be formed by casting or cutting.

  As described above, the first fin plane Maf of the first disc BDA is machined (for example, shaving or polishing) so as to be parallel to the first sliding surface Maa with respect to the first sliding surface Maa. Is molded by. Similarly, the second fin plane Mbf of the second disc BDB is formed by machining so as to be parallel to the second sliding surface Mba with respect to the second sliding surface Mba. Then, the first disk BDA and the second disk BDB are fixed by the hat member HTB and the fastening member TKB so that the first fin plane Maf and the second fin plane Mbf are in contact with each other. For this reason, the first fin plane Maf and the second fin plane Mbf are uniformly faced in a state where the first and second discs BDA and BDB are pressed between the first and second friction pads MSA and MSB. Contact. As a result, the effect of friction damping can be maximized.

<Modification of First Embodiment of Brake Disc BRD>
A modified example of the first embodiment of the brake disc BRD according to the present invention will be described with reference to the cross-sectional view of FIG. In the modification, the fin portion of the second disk BDB is omitted, and the second disk BDB is configured as a flat plate shape.

  Also in the modified example, the two disks BDA and BDB are not abutted against each other at the groove portion. That is, the first fin plane Maf of the first fin portion Fna and the second back surface Mbb (the back side surface of the second sliding surface Mba) of the second disk BDB are in surface contact. For this reason, sufficient contact area and uniform contact surface pressure are ensured, and the effect of friction damping can be exhibited (refer to DD sectional view). As a result, the brake squeal suppressing effect similar to the above is achieved. Note that a gap between the first fin portion Fna of the first disk BDA and the second back surface Mbb of the second disk BDB functions as a vent hole Avn.

  The second disk BDB can be manufactured by adopting an iron plate (for example, a steel plate) and press-molding it. In addition, since the parallelism of two planes is ensured at the time of material manufacture, an iron plate does not need to be newly machined for the assembly | attachment of the brake disc BRD.

  In contrast to the illustrated example, the first disk BDA may have a flat plate shape and the second disk BDB may have a shape having the second fin portion Fnb. In this configuration, the second fin plane Mbf of the second fin portion Fnb is in surface contact with the first back surface Mab (the back side surface of the first sliding surface Maa) and exhibits a friction damping effect. Even in this case, the brake squeal suppressing effect similar to the above is obtained.

<Second Embodiment of Brake Disc According to the Present Invention>
A second embodiment of the brake disc BRD according to the present invention will be described with reference to a front view and a cross-sectional view of FIG. In the second embodiment, each of the first and second disks BDD and BDE has a flat plate shape, and an intermediate disk BDC which is a third annular member is provided between the first disk BDD and the second disk BDE. It is done. As described above, constituent members and parts having the same symbol, such as “HTB”, exhibit the same function.

  Similar to the first embodiment, the first and second disks BDD and BDE are attached to the hat member HTB by the fastening member TKB. With reference to EE sectional drawing, the shape of each member and attachment are demonstrated easily. The first disk BDD is a disk member formed in an annular shape. The first disk BDD is in sliding contact with the first friction pad MSA (inner side friction pad) at the outer peripheral portion of the first sliding surface Mda. In the first sliding surface Mda, an area that slides with the first friction pad MSA is a “sliding range” of the first disk BDD. A plane opposite to the first sliding surface Mda (back side) is the first back surface Mdb. A plurality of fastening holes Atd (through holes) are provided in the inner peripheral portion of the first disk BDD.

  Similar to the first disk BDD, the second disk BDE is a thin plate-shaped member formed in an annular shape. The second disc BDE is in sliding contact with the second friction pad MSB (outer side friction pad) at the outer peripheral portion of the second sliding surface Mea. On the second sliding surface Mea, the area sliding with the second friction pad MSB is the “sliding range” of the second disk BDE. A plane opposite to the second sliding surface Mea (back side) is the second back surface Meb. A plurality of fastening holes Ate (through holes) are provided in the inner peripheral portion of the second disk BDE. Here, the first and second disks BDD and BDE can be produced by press-molding an iron plate (for example, a steel plate). Similar to the above, the iron plate does not need to be newly machined for assembling the brake disc BRD because the parallelism between the two planes is ensured at the time of material production.

  Hat member HTB is integrally fixed to hub unit HUB and wheel WH by hub bolt HBL and wheel nut WNT. The inner peripheral surface Mhd of the first disc BDD, the inner peripheral surface Mhe of the second disc BDE, and the inner peripheral surface Mhc of the intermediate disc BDC are fitted to the cylindrical outer peripheral surface Mht of the hat member HTB with a slight gap. , And is fixed by a fastening member TKB (for example, a caulking member). Here, the fastening part by the fastening member TKB is on the inner peripheral side (side closer to the rotation axis Jwh) than the sliding range.

  The intermediate disk BDC is provided between the first disk BDD and the second disk BDE so as to be sandwiched between the first disk BDD and the second disk BDE. Grooves (concave portions) Zmd and Zme are alternately formed on both surfaces Mcd and Mce of the intermediate disc BDC (planes in contact with the first and second discs BDD and BDE). That is, the first groove portion Zmd is provided on the first contact surface Mcd that contacts the first sliding surface Mda of the first disc BDD. A second groove portion Zme is provided on the second contact surface Mce that contacts the second sliding surface Mea of the second disc BDE. And the 1st groove part Zmd and the 2nd groove part Zme are alternately provided by the front and back of the intermediate | middle disc BDC. The first and second groove portions Zmd and Zme of the intermediate disc BDC form a vent hole Avn when the brake disc BRD is assembled.

  The first disk BDD, the intermediate disk BDC, and the second disk BDE are overlapped and fixed. Therefore, the first back surface Mdb of the first disk BDD and the first contact surface Mcd of the intermediate disk BDC are in surface contact with each other in a state that allows minute displacement. Further, the second back surface Meb of the second disk BDE and the second contact surface Mce of the intermediate disk BDC are in surface contact with each other in a state that can be finely displaced. Here, the plane in which the first back surface Mdb and the first contact surface Mcd are in contact and the plane in which the second back surface Meb and the second contact surface Mce are in contact are the contact surfaces Mms.

  Similar to the first embodiment, when a brake squeal occurs, minute mutual movement occurs on the contact surface Mms. At this time, a frictional force is generated between the contact surfaces, and a brake squeal can be reduced by a damping effect by the frictional force.

<Intermediate disk BDC>
The intermediate disk BDC in the second embodiment will be described with reference to the front view and partial side view of FIG. First and second groove portions Zmd and Zme are provided on both surfaces (first and second contact surfaces) Mcd and Mce of the intermediate disk BDC. The first and second groove portions Zmd and Zme function as vent holes Avn. That is, the first and second groove portions Zmd and Zme are extended from the inner peripheral portion of the intermediate disk BDC toward the outer peripheral portion.

  For example, the first and second groove portions Zmd and Zme are first manufactured by casting. Then, after casting, machining (for example, machining such as cutting and grinding) is performed on the top surfaces Mcd and Mce of the convex portions constituting the grooves. By the machining, the highly accurate parallel first and second contact surfaces Mcd and Mce can be easily formed. For this reason, friction damping can be effectively ensured.

  As described above, a core is not necessary for forming the first and second groove portions Zmd and Zme by casting. Therefore, there is no trade-off with the core strength, and the shapes of the first and second groove portions Zmd and Zme (that is, the fin shape) can be optimized considering only the cooling performance.

  A coaxial with the hat member HTB is secured at the inner peripheral side surface Mhc of the intermediate disk BDC which is an annular member. However, since the intermediate disk BDC does not bear the braking torque, the intermediate disk BDC does not need to be fixed by the fastening member TKB.

  The first and second groove portions Zmd and Zme are alternately provided on both surfaces (first and second contact surfaces) Mcd and Mce of the intermediate disk BDC, but the groove portion on either one of the surfaces can be omitted. The surface on the side where the groove is omitted is a uniform plane.

<Other embodiments>
As described above, in the brake disc BRD according to the present invention, the planes Maf, Mbf, Mcd, and Mce of the disc members BDA, BDB, and BDC that form the air vent Avn are machined (cut, ground, and polished). At least one of them). Therefore, each plane Maf, Mbf, Mcd, and Mce is flat, and sufficient parallelism is ensured with respect to the sliding surfaces Maa, Mba, Mda, and Mea. And since the contact surface Mms is comprised by the highly accurate plane Maf, Mbf, Mcd, and Mce, the area which can be utilized for friction damping is fully ensured, and a uniform contact state is obtained. As a result, brake squealing can be effectively suppressed by friction damping.

  Hereinafter, other embodiments will be described. In other embodiments, the same effect (effectively exerting frictional damping, simplified frictional damping configuration) is obtained.

  The caulking is exemplified in the connection between the first disks BDA and BDD and the second disks BDB and BDE. As the fastening member TKB, a screw fastening member may be employed instead of the caulking member. Moreover, welding (for example, spot welding) may be employed as a fixing method. Even in such a fixing method, a minute displacement between the disks can be ensured. Further, a disc spring or the like can be added to the fastening portion in order to keep the fastening axial force between the disks within an appropriate range.

  The fastening hole Ath of the hat member HTB can be formed as a long hole shape. The disk members BDA, BDB, BDD, and BDE are thermally expanded by heat generated during braking. In this case, the inner peripheral surfaces Mha, Mhb, Mhd, and Mhe of each member are expanded in diameter, but are allowed to be separated from the outer peripheral surface Mht of the hat member HTB by the elongated hole-shaped fastening hole Ath. As a result, the deformation of the hat member HTB can be suppressed.

  In the above embodiment, the hat member HTB and the disk member (BDA or the like) are configured as separate members. Either one of the two disks and the hat portion can be integrally formed. Then, the other of the two discs is fastened at the hat portion in a state where the disc can be slightly displaced.

  In the above embodiment, the inner brake pad located on the side farther than the wheel disc portion of the wheel WH (that is, the inner side in the left-right direction of the vehicle) is the first friction pad MSA and is closer to the wheel disc portion of the wheel WH. The outer brake pad located on the outside (that is, the outside in the left-right direction of the vehicle) is the second friction pad MSB. Accordingly, the disk member on the inner side (inner side in the left-right direction of the vehicle) is the first disk BDA, BDD, and the disk member on the outer side (outer side in the left-right direction of the vehicle) is the second disk BDB, BDE. . However, these may be reversed. That is, “the inner side” can be the second friction pad and the second disk, and “the outer side” can be the first friction pad and the first disk.

BRD ... brake disc, MSA, MSB ... first and second friction pads, BDA, BDB ... first, second disc, BDD, BDE ... first, second disc, BDC ... intermediate disc, HTB ... hat member, TKB ... fastening member, Avn ... vent hole, Fna, Fnb ... first and second fin parts, Maa, Mba ... first and second sliding faces, Mab, Mbb ... first and second back faces, Maf, Mbf ... first 1, second fin plane, Mda, Mea ... first, second sliding surface, Mdb, Meb ... first, second back surface, Mcd, Mce ... first, second contact surface, Zmd, Zme ... first, Second groove part.

Claims (3)

A brake disc that is fixed to a vehicle wheel and sandwiched between two friction pads to generate a braking force on the wheel,
A first disk in sliding contact with one of the two friction pads on a first sliding surface;
A second disk in sliding contact with the other of the two friction pads on a second sliding surface;
With
The first disk has a first fin portion that is a plurality of elongated protrusions on a first back surface that is opposite to the first sliding surface.
The second disk has a plurality of elongated protrusions on a second back surface opposite to the second sliding surface, and has a second fin portion that is mirror-symmetrical with the first fin portion,
A first fin plane formed in parallel to the first sliding surface in the first fin portion and a second fin plane formed in parallel to the second sliding surface in the second fin portion are surfaces. Brake disc, fixed to contact. A brake disc that is fixed to a vehicle wheel and sandwiched between two friction pads to generate a braking force on the wheel,
A first disk in sliding contact with one of the two friction pads on a first sliding surface;
A second disk in sliding contact with the other of the two friction pads on a second sliding surface;
With
The first disk has a first fin portion that is a plurality of elongated protrusions on a first back surface that is opposite to the first sliding surface.
A first fin plane formed in parallel with the first sliding surface in the first fin portion and a second back surface opposite to the second sliding surface of the second disk are in surface contact. Fixed to the brake disc. A brake disc that is fixed to a vehicle wheel and sandwiched between two friction pads to generate a braking force on the wheel,
A first disk in sliding contact with one of the two friction pads on a first sliding surface;
A second disk in sliding contact with the other of the two friction pads on a second sliding surface;
An intermediate disk provided between the first disk and the second disk;
With
Two planes of the intermediate disk are parallel, and a plurality of elongated grooves are formed in at least one of the two planes;
A brake disc fixed so that the first disc and the intermediate disc are in surface contact and the second disc and the intermediate disc are in surface contact.