Showing papers on "Disc brake published in 1996"

Effects of Cu Powder, BaSO4 and Cashew Dust on the Wear and Friction Characteristics of Automotive Brake Pads

Abstract: Brake pads used in automotive disk brakes are generally made of many components such as phenolic resin, aramid fiber, Cu powder, BaSO4, and cashew dust. Using a slider-on-disk-type wear tester, the friction and wear characteristics of the pad against the disk made of cast iron at high disk temperature (above 80°C) were studied with varying the content of the components. In particular, the relation between the sudden decrease in friction (fade) and the wear rate were closely studied. The experimental, result of the wear test was also analyzed, systematically by the multiple regression method and the effects of the components were clarified quantitatively. Presented at the 50th Annual Meeting in Chicago, Illinois May 14–19, 1995

Method of casting a composite disc brake rotor

Abstract: A generally annular rotor insert is formed by casting a metal matrix composite. The rotor insert includes a pair of brake friction plates which are disposed in mutually spaced apart relationship. The brake friction plates include inner surfaces and generally parallel outer surfaces. At least one of the inner surfaces of the brake friction plates is provided with a plurality of spacing elements for engagement with the inner surface of the other one of the brake friction plates for maintaining the plates in predetermined spaced apart relationship. The rotor insert is placed in a rotor mold. A hat-shaped rotor body is cast in the rotor mold whereby the spacing elements are effective to maintain the plates in a predetermined spaced apart relationship.

Damper for brake noise reduction

Abstract: An apparatus for reducing unwanted brake noise has a ring damper affixed around a periphery of a brake rotor in a disk brake system in a manner that permits relative motion and slippage between the ring damper and the rotor when the rotor vibrates during braking. In a preferred embodiment, the ring damper is disposed in a groove formed in the periphery of the disk and is pre-loaded against the rotor both radially and transversely. The ring damper is held in place by the groove itself and by the interference pre-load or pre-tension between the ring damper and the disk brake rotor.

Bicycle disc brake

Abstract: An hydraulic, cable-actuated disc braking assembly for a bicycle (10) with a main unit (20) including a master cylinder or housing (32), reservoir housing (36), brake piston housing (38) wherein the assembly (20) provides a compact, lightweight braking arrangement with compensating piston biasing structure (52). Durability and reliability are achieved by the use of a compensating chamber (54) along with the piston (52) and compensating piston biasing member (56).

Automotive parking brake and parking brake system for motor vehicles

Abstract: In order to improve an electrically actuatable automotive parking brake with mechanical emergency actuation, the brake pads (52, 54) of the parking brake, which may be either a disk brake or a drum brake, can be applied or released via gear arrangement (100) arranged within or at the brake. The gear arrangement (100) has one power input and one power output, with the power input being coupled with the one end of a flexible shaft, the other end of which being arranged remote from the brake can be coupled with a manual crank, in order to be able to actuate the parking brake mechanically in the case of a failure of the electric actuation.

Disc brake for vehicles having insertable actuator

Abstract: A brake disk for road vehicles has a brake caliper engaging about a brake disk of a vehicle wheel to be braked. A clamping unit upon which an actuation cylinder can act is provided on one side of the brake disk and which itself acts against at least one pressure member. In order to withstand the braking forces in a manner free from sealing problems, the caliper is constructed in one part such that the clamping unit is mounted in a section of the caliper which is substantially closed on all sides. When the caliper is moved away from the brake disk, the clamping unit can be introduced, in the form of a preassembled unit into the caliper through the opening therein facing the brake disk. When the clamping unit has been introduced, the opening in the brake caliper facing the brake disk is closed by a closure plate penetrated by the pressure member of the clamping unit.

Vibration damping device for disc brake

Abstract: A vibration damping mechanism for use in a disc brake which can effectively suppress squeaks of the disc brake during braking. Vibrations of the rotor are detected by a piezoelectric element pressed against the back of an inner pad. The detection signal is inputted in a control circuit. The control circuit applies a control signal to another piezoelectric element which produces oscillations having a frequency that can reduce the detection signal to zero. The oscillations produced by the piezoelectric element are transmitted to the rotor to cancel the vibrations of the rotor. With this arrangement, signal components other than the rotor vibrations are scarcely contained in the detection signal, so that it is possible to produce oscillations that can cancel vibrations of the rotor with high accuracy. As a result, the rotor vibrations and thus squeaks of the disc brake are effectively suppressed.

Brake actuator for an electrically actuable vehicle brake

Abstract: A brake actuator for electrically actuated vehicle brakes includes a spindle assembly without additional gear stages The forces required for engaging the brake are realized herein by utilizing the spindle assembly The brake actuator includes a brake pad which is pressed against a brake disc with the aid of an electric motor (4) operating as an electric drive A planetary-roller spindle assembly operatively connects the electric motor to a brake piston on which the brake pad is mounted The electric motor (4) is connected via the spindle assembly to the brake piston (32) The spindle assembly (16) is arranged in the displacement direction of the brake pad and the brake piston (32) is journalled so as to be axially displaceable with the brake pad The spindle assembly (16) includes a spindle rod (18) which is mounted so as to be an extension of the rotor (8) of the electric motor (4) The brake piston (32) is mounted so that it is held against rotation and is formed to define a unit with the spindle nut (20) of the spindle assembly (16) Alternatively, the rotor (8) of the electric motor (4) can be fixedly attached to the spindle nut (20) so that the spindle nut rotates with the rotor The rotor then has a hollow cavity for accommodating the spindle rod (18') therein

Electrically-operated disc brake assemblies for vehicles

Abstract: An electrically operated disc brake assembly for vehicles of the kind in which a friction member (9) is adapted to be applied to a rotatable brake disc (2) by a brake applying mechanism which includes an electric motor (3) and a transmission which is adapted to apply an axially directed brake applying force to the friction member (9) in response to operation of the motor (3) so that the transmission acts on the friction member (9) at circumferentially spaced locations. This produces a substantially even loading across the friction member/disc interface, reducing the magnitude of the reaction torque. In one embodiment, the transmission comprises a pair of axially spaced screw devices (4,5) which are rotatable by the motor (3) acting through a common gear train (6), and the motor may further be provided at the center of mass of the brake.

Vehicle brake and hub attachment system and method

Abstract: A wheel end hub assembly for a motor vehicle incorporating mechanical retention features. The assembly accurately and positively orients the motor vehicle brake component, such as a disc brake rotor or brake drum with respect to its wheel hub. Accordingly, the machining operations for the brake component braking surfaces can be accurately based from a datum surface of the hub. The assembly incorporates a retention nut threaded onto the wheel mounting bolts which exerts a clamping force on the brake component and further establishes the relative positions of the hub and brake component. The retention nut features a generally conical surface which contacts a generally conical surface of the brake component to establish the radial and rotational relative position of these components.

Electrically-operated disc brake assemblies for vehicles

Abstract: In a brake assembly in which an electric motor operates to apply the brake through a screw device, the screw device comprises a recirculating roller screw assembly which is adapted to be driven from the electric motor through a gear train, and the roller screw assembly comprises a fine pitch recirculating roller screw.

Disk brake rotor exhibiting different modes of vibration on opposite sides during braking

Abstract: A disc brake rotor has a plurality of radial groves on its opposite sides that are equiangularly spaced. The angular interval of the grooves on one side is different from the angular interval of the grooves on the other side, so that the vibrations of two different modes caused by the grooves on the opposite sides interfere with each other during braking operation. By thus suppressing stationary wave mode vibrations, the disc brake rotor prevents production of brake squeals.

Disk brake application device

Abstract: An application device (28) for a disk brake (10), in particular for a floating calliper or floating frame, partially lined disk brake for trucks or busses, has at least one plunger (46) capable of moving in the direction of one of its axis (C) in order to apply a brake lining (22) to a brake disk, and at least one eccentric (38) mounted in at least one rolling bearing (40) and capable of rotating around a transverse axis (B) to actuate the brake. A rolling body (44) for transmitting actuating forces to the plunger (46) is mounted on the eccentric (38) by means of a bearing shell (42). In order to avoid wear-promoting states within the brake application device, the bearing shell (42) has a projection (78) that extends outwards at least approximately in the radial direction in relation to the transverse axis (B). The projection (78) is designed to engage a cage (84) of the rolling bearing (40) and can return the cage (84) to a defined starting position when the brakes are released.

Vibration damper for use in disk brake

Abstract: Proposed is a vibration damper for suppressing squeaks of a disk brake by positively damping vibrations of the brake. It is a high-performance, highly reliable vibration damper with no accurate machining required. This vibration damper has pressing pistons (9) received in brake pistons (5) so that brake fluid pressure acts thereon. It further includes a vibration detecting means (7) for detecting brake vibrations through one of two pads (3), and a vibration imparting means (8) for vibrating the other pad (3) based on detection signals of the vibration detecting means (7) so as to cancel out the vibrations detected by the vibration detecting means (7). They are pressed against the back of the respective pads (3) by the respective pressing pistons (9). By pressing them at a suitable pressure against the pads (3), it is possible to detect vibrations and vibrate the pads (3) with high reliability. When replacing the pads (3), these means (7,8) never protrude from the pad pressing surfaces, so that they are less likely to be damaged or destroyed.

Preparation of textile preforms for brake discs in composite material

Abstract: A textile preform for making a brake disc in composite material is manufactured by superposing and inter-linking two textile layers. Structural textile layers (10) are used for forming at least a first preform part to constitute the textile reinforcement of the brake disc core, while the (or each) part of the preform for constituting the textile reinforcement of the friction part of the brake disc is made of felt (16, 18) at least in the part adjacent to the friction surface.

Realistic Braking Operation Simulation of Ventilated Disk Brakes

Abstract: A three-dimensional numerical method for the prediction of transient temperatures reached during realistic braking operations in a ventilated disk brake assembly is presented in this paper. This Layered FFT-FEM numerical method (Fast Fourier Transform-Finite Element Method) takes advantage of the high Peclet number “skin effect” to decouple the moving boundary contact problem from the spatially periodic but non-axisymmetric cooling associated with the vents. The first problem is modeled according to the FFT-FEM method developed previously by the authors. This technique succeeded in using high Peclet numbers for axisymmetric moving solids submitted to general loading conditions. No numerical convergence problems are encountered and short computer time is required. The second problem is modeled according to traditional three-dimensional finite element techniques. The Layered FFT-FEM results are compared with analytical results. A braking operation is simulated for an industrial ventilated disk brake.

Vehicle-parking brake and parking brake system for vehicles

Abstract: The automobile standing brake uses a disc brake (10), or a drum brake, with an operating drive (100) for the brake pads coupled on the input side to one end of a flexure shaft, which is operated by a handcrank at the other end, for mechanical operation of the brake upon electrical failure. Pref. the first end of the flexure shaft is secured to the armature shaft of an electric motor (18) used for electric operation of the standing brake via a worm gearing (22, 24) coupled to the brake piston (44) of the disc brake.

Disc-hub connection, in particular for utility vehicle disc brakes

Abstract: The invention concerns a disc-hub connection (1) for connecting a brake disc (2) to a hub (3), in particular for utility vehicle disc brakes. In its inner peripheral region the brake disc (2) comprises support elements (7), the hub (3) comprising cams (8) in its outer peripheral region. Intermediate elements (9) are used to transfer torque from the cams (8) of the hub (3) to the support elements (7) of the disc (2), the cams (8) of the hub (3) engaging in the intermediate elements (9) and the latter engaging in the support elements (7).

Disc brake with automatic adjusting device

Abstract: The invention concerns a disc brake with an automatic adjusting device, wherein a nut (12) connected to a coupling element (13) is screwed onto an axially displaceable, rotationally rigid spindle (11). An auxiliary piston (32) is displaceably mounted in a bore (31) in the brake piston (4) and connected to the nut (12) by an axially engageable snap-action connection (35, 37, 38).

Reinforced carbon fibre composite brake disc

Abstract: The brake disc has at least one friction surface (7) with a frictional body (5) and at least one shaped body (6). The shaped body is joined with the frictional body. At least one part of the frictional body has heat conduction in a direction normal to its surface higher than that of the friction surface itself.

Brake disk and method of making same

Abstract: The invention relates to a hat-shaped brake disc made from a castable metal for vehicle wheels. It has, within the friction ring, a nave with a nave casing and nave bottom, the latter having screw-passage holes for screwing the brake disc to the wheel hub. The friction ring contains indentations rounded out on both sides in the region of transition to the nave casing. The brake disc consists completely, up to and including that immediate surface of the friction ring which is subjected to frictional stress during braking, of a particle reinforced composite aluminum material with intercalated hard-material particles of ceramic, particularly of aluminum oxide or silicon carbide (so-called Al-MMC=Aluminum-Metal-Matrix-Composite) and/or of a hypereutectic Al/Si alloy with intercalated silicon crystals. It is designed and produced as a die casting, all the surface parts of the casting being cast with a very small shape and dimension deviation. Only the frictionally-stressed surfaces of the friction ring and, where appropriate, a frictionally-stressed hollow-cylindrical brake surface inside the nave need to be machined by cutting. A radially projecting flange is arranged on the outside of the nave at the transition from the nave bottom to the nave casing, via which flange the brake disc can be secured axially in or on a workpiece holder during machining.

Friction, Temperature, and Wear Analysis for Ceramic Coated Brake Disks

Abstract: Coating adherence, friction coefficient, surface temperature, and wear mass loss are determined for a set of scale reduced steel brake disks on which NiCr cement based coatings and low conductivity subcoatings are plasma sprayed. The related pads are made of either sintered iron copper or sintered aluminum titanate. It is mainly shown that NiCr-Cr 3 C 2 cermet coating on the disk, coupled with sintered aluminum titanate pad, leads to good damage resistance and stable friction coefficient in the simulation of high speed train braking. Low conductivity sublayers are also involved and it is found that temperatures in disc or pad may be also controlled.

Slide pin bushing and boot seal assembly for disc brake assembly

Abstract: An improved structure for a slide pin bushing and boot seal assembly for use in a vehicle disc brake caliper assembly adapted to selectively frictionally engage a rotor connected to a vehicle wheel includes an anchor plate adapted to be secured to a stationary component of the vehicle, and a caliper secured to the anchor plate for sliding movement relative thereto. A pair of brake shoes are carried by the disc brake caliper assembly, and an actuation means is provided for selectively moving the brake shoes axially toward and away from one another so as to selectively frictionally engage the rotor. The slide pin bushing and boot seal assembly is carried by the disc brake caliper assembly and includes a slide pin bushing formed from a relatively hard resilient elastomeric material and a boot seal formed from a relatively soft flexible elastomeric material and joined to one end of the slide pin bushing to define an integral one-piece unit. A slide pin extends through the boot seal and at least a portion of the slide pin bushing for securing the caliper to the anchor plate for sliding movement relative thereto.

Disc brake for vehicle

Abstract: PROBLEM TO BE SOLVED: To uniformly press a pair of friction pads even if there is a difference in height in the peripheral edge of an opening part of a caliper body by making an engaging part of a pad spring engage with the caliper body in such a manner as to stride over the butt parts of a pair of caliper half bodies. SOLUTION: Friction pads 4, 4 are suspended by a hanger pin 9 mounted on a caliper body 3 in such a manner as to move in the axial direction of a disc. A pad spring 10 for pressing the friction pads 4, 4 is installed in an opening part 3b. An engaging part 10a engaged with the peripheral edge of the opening part 3b is formed on one end of the pad spring 10. The engaging part 10a is formed to have such a size that even if the disc outer peripheral side heights of the connecting parts 5b, 6b of the caliper main body are varied by accumulation of manufacturing allowance, tilting is not caused. Accordingly, the pad spring 10 is not tilted even if the height of the peripheral edge of the opeing part 3b is varied, so that the pressing part 10b can uniformly press a pair of friction pads 4, 4.

Optimization of Design of Railway Disc Brake Pads

Abstract: High temperatures are one of the main problems encountered in disc brakes, contributing to rapid wear and poor braking performance. In this paper, a two-dimensional finite element model using a the...

Vibration damping device for a disc brake

Abstract: A vibration damping mechanism for use in a disc brake which can effectively suppress squeaks of the disc brake during braking. Vibrations of the rotor (1) are detected by a piezoelectric element (7-1) pressed against the back of the inner pad (2a). The detection signal is inputted in a control circuit (9). The control circuit (9) applies a control signal to another piezoelectric element (7-2) to produce oscillations having such a frequency that they can reduce the detection signal to zero. The oscillations produced by the piezoelectric element (7-2) are transmitted to the rotor (1) to cancel its vibrations. With this arrangement, signal components other than the rotor vibrations are scarcely contained in the detection signal, so that it is possible to produce oscillations that can cancel vibrations of the rotor (1) with high accuracy. As a result, the rotor vibrations and thus squeaks of the disc brake are effectively suppressed.

Disc brake for vehicles, in particular road vehicles

Abstract: The invention concerns a disc brake for vehicles, in particular road vehicles, wherein a brake caliper (1) engaging about the brake disc (3) of a vehicle wheel to be braked is provided and contains on one side of the brake disc a clamping unit (13) upon which an actuation cylinder can act and which itself acts against at least one pressure member (35; 37). In order to withstand the braking forces in a manner free from sealing problems, the caliper (1) is constructed in one part such that the clamping unit (13) is mounted in a section of the caliper (1) which is substantially closed on all sides. When the caliper (1) is moved away from the brake disc (3), the clamping unit (13) can be introduced, in the form a pre-assembled unit, into the caliper (1) through the opening therein facing the brake disc (3). When the clamping unit (13) has been introduced, the opening in the brake caliper (1) facing the brake disc (3) is closed by a closure plate (41) penetrated by the pressure member (35; 37) of the clamping unit (13).

A brake disk with built-in acoustic wear-warning device

Abstract: A disk brake comprising a disk (1) which carries on each side a secondary friction layer (7) to which a primary friction layer (6) is affixed, wherein the friction layers (6, 7) are actuable by brake shoes (4, 5), wherein when at least one of the primary friction layers (6) is worn away contact between the secondary friction layer (7) and respective brake shoes (4, 5) will give rise to an indicating sound, and wherein cooling grooves (9) are provided in the primary friction layer (6), wherein each cooling groove (9) extends at least through the full thickness of the primary friction layer (6).