The plate disc brake of band parking and braking mechanism
Technical field
The present invention relates to a kind of Vehicular brake device, specifically, relate generally to a kind of plate disc brake with parking and braking mechanism.
Background technology
The plate disc brake of the present band parking and braking mechanism that generally uses, be installed in the trailing wheel of vehicle, service brake and braking during standstill dual-use function are arranged, the service brake mechanism of such drg is basic identical, parking and braking mechanism mainly contains two kinds, i.e. rotating disk ball-type halting mechanism and unsteady connecting rod centering type halting mechanism.
The principle of work of rotating disk ball-type halting mechanism is that hand braking cable wire drives a rotating shaft, and one in rotating shaft and two disks connects together, and two disks are arranged in opposite directions, are inlaid with Metal Ball between them.Under the driving of disk, Metal Ball ball with a slope along the circumferential direction scrolls up with the ramp, and the distance between two disks is strengthened, thereby promotes piston, brake shoes generation braking.Its shortcoming is the influence that braking force is subjected to ball moving radius, the gradient, friction coefficient size, and the braking force work maxim of halting mechanism is restricted, so its auxiliary brake function is not strong, the Parking that only can satisfy under the certain condition is used.As publication number is the cylinder body that the application for a patent for invention of CN1406320A discloses a kind of plate disc brake with parking and braking mechanism, this cylinder body comprises a piston and a parking and braking mechanism, this parking and braking mechanism comprises one when the input shaft that carries out being driven in rotation when braking during standstill is handled, with a ball ramp device, this ball comprises with the glass duct device: at least one opens first groove on input shaft; At least one is relative with first groove and open second groove on a member, and described member is suitable for promoting piston along the direction of described dish; And at least one is limited at the ball in the groove; Each groove comprises a zone of departing from exclusive concave shape, when input shaft rotates with respect to described mechanism, described ball rolled in described departing from the zone, and in F/s, eliminated the gap of device, in subordinate phase, move described mechanism along piston direction with respect to input shaft.This patent application has also related to the plate disc brake that comprises this class cylinder body.Though the halting mechanism of this drg can be eliminated the gap that exists in the parking and braking mechanism apace, the auxiliary brake function of its halting mechanism is not strong, and the Parking that only can satisfy under the certain condition is used.
The principle of work of unsteady connecting rod centering type halting mechanism is that hand braking cable wire drives a rotating shaft, and accentric dome-type nest hole is arranged in the rotating shaft.One of the pole (abbreviation floating lever) that two is round matches with the eccentric nest hole in the rotating shaft, and the ball-type nest hole on the screw rod of other end and screw thread compensation mechanism cooperates.When rotating shaft was rotated, the eccentric nest hole in the rotating shaft made floating lever move along the piston axis direction, and floating lever promotes piston and brake shoes by the screw thread compensation mechanism, thereby produces braking.Its shortcoming is to be subjected to the restriction of piston motion distance and rotating shaft rotational angle interrelation and the restriction that the drg return requires, no small angle of the certain existence of rotating shaft and floating lever, and this angle can produce the component of no small non-braking force direction.Cause the auxiliary brake function of halting mechanism not strong, also only can satisfy the Parking needs.
Summary of the invention
The invention provides a kind of plate disc brake with parking and braking mechanism, this parking and braking mechanism braking force is big, simple in structure, safe and reliable.
A kind of plate disc brake with parking and braking mechanism comprises the cylinder body of plate disc brake, comprises in the cylinder body that one is suitable for to an axially movable main piston of brake disc direction, parking and braking mechanism and shoe plate compensation mechanism, and parking and braking mechanism comprises:
One eccentrically weighted shaft, the eccentric shaft of another different axis of design on a circular shaft, when circular shaft rotated, the axis circle of revolution axis of eccentric shaft rotated, and circular shaft and rotating shaft arm-tie are fixed together;
One slide plate slides mechanism: be made up of sliding support plate, needle roller, grid, screw pull axis, needle roller is formed the plane rolling bearing in grid; Sliding support plate is positioned at a side of grid, one end face of sliding support plate and the circumferential contact of described eccentric shaft, the other end of sliding support plate contacts with needle roller, and needle roller contacts with screw pull axis at the another side of grid, and screw pull axis moves and can drive main piston and move.
Described sliding support plate is positioned in the screw pull axis by the slide plate card.
Described screw pull axis resets by cardan shaft fixed cover and the spring that is fixed on the cylinder body, makes end face, needle roller, the sliding support plate of screw pull axis, the surface of eccentrically weighted shaft be close together mutually.
Described shoe plate compensation mechanism is located between screw pull axis and main piston, form by advancing swivel nut, compensation surface bearing, jump ring, described screw pull axis is connected with an end internal whorl that advances swivel nut, advances the other end of swivel nut to contact with the main piston inside face; Advance between swivel nut and screw pull axis negative thread bonded assembly one end outside and main piston and be provided with the compensation surface bearing; One side of compensation surface bearing offsets with the inner platform that advances swivel nut, and the main piston inside of the front portion of another side is provided with a jump ring, advances swivel nut to be positioned main piston inside by jump ring.
When eccentrically weighted shaft rotated, eccentric shaft promoted the motion that slide plate slides mechanism does orthogonal X, Y both direction simultaneously, and the directions X motion is that its friction coefficient is very little, so directions X does not produce the consumption of power substantially by the rolling of needle roller in grid.The motion of Y direction then promotes piston motion, produces braking.So the mechanical property of this mechanism is fine, the torsion of rotating shaft all can be converted into braking force.
Owing to adopt slide plate slides, halting mechanism is handled very flexible, stuck, return phenomenon not can not occur.Because enough braking forces are arranged, so behind the running brake failure, halting mechanism can play the effect of emergency braking well, just this drg has the double effects of Parking and emergency braking.
The present invention also is provided with the screw thread compensation mechanism, when shoe plate weares and teares, by the action of screw thread compensation mechanism, makes that the relative distance of main piston, shoe plate and brake disc remains unchanged before each braking, and promptly Sha Che stroke is constant.The worn-down compensation makes drg safer, reliable.
Description of drawings
Fig. 1 is the cutaway view of a plate disc brake of embodiments of the present invention;
Fig. 2 is the structural representation of parking and braking mechanism of the present invention;
Fig. 3 is needle roller and a grid part enlarged diagram among Fig. 2;
Fig. 4 be among Fig. 2 A-A to cutaway view;
Fig. 5 is the structural representation of parking and braking mechanism after moving;
Fig. 6 be among Fig. 5 B-B to cutaway view.
The specific embodiment
Its agent structure of plate disc brake shown in Figure 1 and common hydraulic braking wheel cylinder are basic identical, when the vehicle user steps on brake pedal, braking liquid enters in the cylinder body 28 of drg by oil inlet 2, oil-feed screw 1, hydraulic drive main piston 21 moves to the Y direction, main piston 21 promotes brake shoes 29 and embraces brake disc 30 generation brakings, and 21 of cylinder body 28 and main pistons are provided with seal ring 24 and dust ring 26.This device is well known to those skilled in the art, no longer describes in detail among the present invention.
The present invention is the plate disc brake of a band halting mechanism, cylinder body 28 also has a cover parking and braking mechanism, and it is driven by hand braking handle, cable wire (not drawing among the figure), through a series of pure mechanical drive, drive main piston 21 and brake shoes 29 motions, realize braking.
The structure of a kind of embodiment of the present invention is:
One eccentrically weighted shaft; Be installed in the circular slotted hole 3 of cylinder body 28, eccentrically weighted shaft is the eccentric shaft 4 of another different axis of design on a circular shaft 8, when circular shaft 8 rotates, and the rotate rotational of circular shaft 8 of the axis of eccentric shaft 4; Eccentrically weighted shaft and circular slotted hole 3 are coaxial with the footpath, with seal ring 9 and rubber oil sea 11 sealings; Circular shaft 8 upper ends and rotating shaft arm-tie 10 are fixed together.
One slide plate slides mechanism: form by sliding support plate 5, needle roller 6 (also can be roller bearing), grid 7, screw pull axis 13, sliding support plate 5 is positioned the inside of screw pull axis 13 by slide plate card 12, screw pull axis 13 resets by the spring 19 that is fixed on the cardan shaft fixed cover 17 on the cylinder body 28 and be sleeved on the screw pull axis 13, makes end face, needle roller 6, the sliding support plate 5 of screw pull axis 13, the surface of eccentrically weighted shaft 4 be close together mutually.Needle roller 6 is formed the plane rolling bearing in grid 7; Sliding support plate 5 is positioned at a side of grid 7, sees Fig. 3, shown in Figure 4.The circumferential contact of sliding support plate 5 one end faces and described eccentrically weighted shaft 4, the other end contacts with needle roller 6, and needle roller 6 rolls in grid 7, and needle roller 6 contacts with screw pull axis 13 at the another side of grid 7.Under the promotion of sliding support plate 5, needle roller 6 rolls in its grid 7, and just sliding support plate 5 moves along directions X on non-resistance ground substantially.Simultaneously, the part that contacts of the needle roller 6 of the end of screw pull axis 13 and slide plate is a smooth plane.
The shoe plate compensation mechanism is located at 21 of screw pull axis 13 and main pistons, form by advancing swivel nut 27, compensation surface bearing 23, jump ring 22, described screw pull axis 13 is connected with an end internal whorl that advances swivel nut 27, advances the other end of swivel nut 27 to contact with main piston 21 inside faces; Advance swivel nut 27 and screw pull axis 13 negative thread bonded assemblys one end outside and 21 of main pistons to be provided with compensation surface bearing 23; One side of compensation surface bearing 23 offsets with the inner platform that advances swivel nut 27, main piston 21 inside of the front portion of another side have groove, the inner jump ring 22 that embeds, when main piston 21 moves, driving jump ring 22 moves, jump ring 22 can contact with compensation surface bearing 23, advances swivel nut 27 to be positioned main piston 21 inside by jump ring 22, and by seal ring 25 sealings.
As Fig. 2,3,4, the cable wire of parking brake and rotating shaft arm-tie 10 are fixing, and rotating shaft arm-tie 10 and circular shaft 8 are fixing, and the pulling parking brake drives 10 rotations of rotating shaft arm-tie, makes circular shaft 8 together with O
1For axis rotates synchronously, the axis of the eccentric part of eccentric shaft 4 is O
2, when circular shaft 8 with O
1For rotating α angle, O in the axle center
2Too with O
1For rotating α angle, i.e. O in the axle center
2In the Y direction distance h of having moved, promote sliding support plate 5 and do the motion of X, Y both direction, because sliding support plate 5 rolls in grid 7 for needle roller 6 in the directions X motion, basic non-resistance, and the motion of Y direction makes screw thread cardan shaft 13, propelling swivel nut 27, distance of main piston 21 motions, just eccentrically weighted shaft promotes main piston 21, brake shoes 25 distance h of having moved, and makes main piston 21 promote brake shoes 29 and embraces brake disc 30 and produce braking, has finished the brake process of halting mechanism.Same reason, by slide plate slides mechanism, the return of halting mechanism is also very flexible.
The shoe plate compensate for wear: the compensation of shoe plate worn-down is finished by the shoe plate compensation mechanism.
After the vehicle user stepped on brake pedal, braking liquid can flow in the cylinder body 28 of drg from oil inlet 2, promoted main piston 21 and moved forward along the Y direction.When shoe plate did not did not wear and tear, relative motion did not take place in screw pull axis 13 and propelling swivel nut 27.When the shoe plate wearing and tearing need compensation, main piston 21 advances swivel nut 27 to move forward along the Y direction by jump ring 22 pullings, reason owing to compensation surface bearing 23, make and advance swivel nut 27 motions to become very easy, advance 27 of swivel nuts and the relative rotation of screw pull axis 13 generations, advance swivel nut 27 to move a distance along the Y direction, its value equals shoe plate worn-down distance.This has just realized the compensation of shoe plate worn-down.
Mechanical state was comparatively desirable when the present invention worked, and the reliability of work is good.
Structure of the present invention is not limited to above-mentioned a kind of embodiment.