CN1389654A - Mechanical disc brakes for vehicles - Google Patents

Abstract

Prevents wear of the output shaft and screw parts, thereby improving their durability, while preventing interference with brake operation due to load biased on the output shaft and screw parts. Reduced friction pad drag. On the action portion 41 of the caliper body 40, a receiving hole 46 and a turnbuckle 100 are provided along the disc axis. The receiving hole 46 accommodates the piston 80 . The screw part 110 is screwed into the sleeve nut 100, and the output shaft 140 is arranged between the screw part 110 and the piston 80. The large diameter portion 144 of the output shaft 140 is provided with a spherical abutment surface 145 for abutting against the abutment surface 84 of the piston 80 . A stopper 170 is fixed to the front end of the output shaft 140 so that the bottom wall 81 of the piston 80 can be elastically held by the stopper 170 and the large diameter portion 144 .

Description

Mechanical disc brakes for vehicles

technical field

The present invention relates to a mechanical disc brake for automobiles, two- or three-wheeled motorcycles, three- or four-wheeled desert vehicles, and golf carts.

Description of prior art

A conventional mechanical disc brake for vehicles is described in Japanese Utility Model Laid-Open Hei 1-30662. In this disc brake apparatus, a brake lever or brake pedal is operated to rotate an input rod connected to a caliper , the rotational force of the input rod is converted into a propulsive force along the axis of the disc, thereby producing a braking action.

In this mechanical disc brake system, as the input rod rotates, the cam plate moves toward the disc motor, and at the same time as this movement, the piston and output shaft move towards the disc motor, causing the output shaft to The front end pad pressing part presses the friction pad against the side of the disc motor.

The output shaft is screwed into the screw part that supports the input rod and the cam plate concentrically, the pad wears on the friction pads and the braking clearance between the side of the disc motor and the friction pads increases by a predetermined amount. In this case, the output shaft moves toward the disc motor and disengages the screw part, so that the braking gap can be set to a predetermined value.

In this type of mechanical disc brake, in addition to the usual braking operation such as when the vehicle is continuously stopped using the brake on a slope, the disc motor is pressed against the disc motor due to the force pulling the vehicle down. The traction torque is generated in the friction pads therein. This traction torque is transmitted through the output shaft adjacent to the friction pad to the part comprising the piston and screw parts, thereby causing those parts as a whole to tilt towards the direction of disc rotation about the disc axis. Not only is this detrimental to the braking operation, but it can cause wear and tear of the inner or outer screws connecting the output shaft to the screw parts.

The first object of the present invention is to provide a mechanical disc brake device in which the traction torque generated in the friction pads during braking is prevented as much as possible from being transmitted to the output shaft and screw parts, so as to effectively prevent the output shaft from and thread loss of screw parts, thereby improving durability while preventing bias loads on the output shaft and screw parts from affecting brake operation.

A second object of the present invention is to provide a mechanical disc brake device for a vehicle in which the traction of the friction pad is suppressed by causing the piston to forcibly retreat when the brake operation is released.

Summary of the invention

The mechanical disc brake for vehicles of the present invention includes: a caliper, including an active part arranged on one side of the disc motor, and a receiving hole is formed in the active part; a cylindrical piston with a bottom, accommodated in the receiving hole to move along the disc axis at a position close to the disc motor; the screw part is screwed into the inner wall of the receiving hole at a position away from the disc motor; and the output shaft is arranged between the screw part and the piston, wherein the output The shaft and screw member advance together towards the disc motor as the input rod rotates, so that the friction pads are pressed against the side of the disc motor by the piston abutting the output shaft, thereby affecting the braking operation.

In the first aspect of the present invention, one of the abutment surfaces of the output shaft and the piston which abut each other are fitted is formed in a spherical convex shape, and the other abutment surface is formed in a spherical concave or spherical convex shape.

In a second aspect of the present invention, in addition to the first aspect, the output shaft has a large-diameter portion provided with a projecting portion on the distal end side of the bottom wall of the piston with respect to the disc motor. The opposing surfaces of the large diameter portion and the bottom wall of the piston are provided with abutment surfaces. A through hole is formed in the bottom wall of the piston along the direction of the disc axis, and the aforementioned protruding portion passes through the through hole and protrudes above the piston toward the disc motor. The protruding portion cooperates with the elastic stopper so that the bottom wall of the piston can be elastically held by the stopper and the large-diameter portion of the output shaft.

According to the disc brake of this constitution, it is possible to prevent as much as possible the traction torque generated in the friction pad from being transmitted by the piston to the output shaft and the screw member, thereby preventing their inclination toward the rotation direction of the disc. This minimizes wear at the connection portion between the output shaft and the screw member while improving their durability. It is also possible to prevent the adverse effect of the bias load on the output shaft and the screw member on the braking action. Uneven wear of the friction pad linings being pulled by the disc motor is minimized because a mating elastic stop at the end of the screw member acts to force the piston away from the disc motor when the brake operation is released change.

Brief description of the drawings

Figure 1 shows a partial sectional front view of a mechanical disc brake according to an embodiment of the present invention;

Figure 2 shows a cross-sectional view of Figure 1 taken along line 2-2 according to an embodiment of the present invention;

Figure 3 shows a cross-sectional view of Figure 1 taken along line 3-3 according to an embodiment of the present invention;

Fig. 4 shows a cross-sectional side view of a mechanical disc brake according to another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

One embodiment of the present invention is described below with reference to the drawings.

The mechanical disc brake 10 includes a caliper body 40 , which is slidable in the direction of the disc axis and is supported by a pair of slidable pins 30 on a bracket 20 installed on the vehicle body.

The measuring body 40 includes an action portion 41 , a reaction portion 42 and a bridge portion 43 . The action part 41 is arranged on one side of the disc motor 50, and the reaction part 42 is arranged on the other side of the disc motor 50, and the bridge part 43 connects the action part 41 and the reaction part 42, and bridges the disc motor at the same time. Around 50. Between the action portion 41 and the reaction portion 42 , a pair of friction pads 60 are suspended by hook pins 70 , so that the disk motor 50 is sandwiched between the friction pads 60 to move along the disk axis.

Extending from both sides of the active part 41 are support arms 44, 44 which project from the frame 20 in a direction away from the disc, having the slidable pins 30, 30 therethrough. One of the support arms 44 , 44 has a retaining arm 45 extending radially outwardly therefrom for allowing the brake cable 150 to pass therethrough as described below.

The action portion 41 has a receiving hole 46 formed on the side of the disk motor 50 . The receiving hole 46 accommodates a piston 80 which is slidable along the disc axis. The piston 80 is formed in the shape of a bottomed cylinder with a thick bottom wall 81 . A through hole 82 is formed on the central axis of the bottom wall 81 . The bottom wall 81 has a spherical concave abutment surface 83 formed on the side facing the disk motor 50 around the through hole 83 .

The action part 41 is provided with a piston actuating mechanism 90 on the side away from the disc motor 50 for actuating the piston 80 . The piston actuating mechanism 90 includes a turn nut 100 , a screw member 110 , an input rod 130 and an output shaft 140 . The socket nut 100 is cast in and welded to the measuring body 40 . The screw member 110 is screwed into the sleeve nut 100 from a side away from the disc motor 50 . The input rod 130 is integrally fixed on the outer front end of the screw member 110 by the locking nut 120 . The output shaft 140 is screwed into the screw part 110 and cooperates with the piston 80 so that the piston 80 can be pushed toward the disc motor 50 .

A turnbuckle 100 coaxial with the receiving hole 46 is formed with a plurality of internal threads 101 on its inner side. The screw member 110 is a cylinder having a plurality of external threads formed on the outer surface side of the disc motor and a plurality of internal threads 112 formed on the inner side away from the disc motor 50 . The end of the screw part 110 away from the disk motor is a protrusion higher than the sleeve nut 100, and its external thread 111 is screwed into the internal thread 101 of the sleeve nut 100, so that the disk motor side is held by the sleeve nut 100 . Since the screwing between the internal thread 101 of the turn nut 110 and the external thread 111 of the screw member 110 employs a multi-start thread with a large lead angle, the screw member 110 can be greatly advanced by a small amount of rotation of the input rod 130 .

The front end of the input rod 130 is connected to one end of the brake cable 150 passing through the holding arm 45 . The other end of the brake cable 150 is connected to a brake pedal or lever (not shown) located near the driver's seat. Between the input rod 130 and the retaining arm 45, one end of the brake cable 150 is covered with the front end of the return spring 160 of the compression assembly. In the case of no operation, the input rod 130, the screw member 110 and the output shaft 140 are biased to the position shown in FIG. 1-3 in the position of the solid line.

The output shaft 140 includes a shaft portion 141 having a smaller diameter extending through the piston 80 and the turnbuckle 100, a larger diameter shaft portion 141 protruding above the turnbuckle 100 on the side away from the disc motor and connected to the shaft portion 141. External thread 142. The external thread 142 has a button 143 integrally formed therewith at its outer end.

The shaft portion 141 of the output shaft 140 forms a flange-shaped large-diameter portion 144 at an approximately central portion thereof. The large diameter portion 144 has a spherically expanded abutment surface 145 on the disc motor side. The large diameter portion 144 of the shaft portion 141 is formed at its front end 146 slightly smaller than the diameter of the through hole 82 of the piston 80 . The front end portion 146 of the shaft portion 141 of the output shaft 140 passes through the through hole 82 , the abutment surface 145 abuts the abutment surface 83 of the piston 80 , and protrudes toward the disc motor 50 above the bottom wall 81 of the piston 80 . At the same time, the front end of the protruding front end portion 146 is engaged with a stopper 170 using a wave washer. The bottom wall 81 of the piston 80 is thus elastically held between the stopper 170 and the large-diameter portion 144, thereby connecting the piston 80 and the output shaft 140 along a straight line in the disc axis direction.

Thus connected piston 80 or output shaft 140 can independently tilt laterally due to the elastic force provided by spherical abutment surfaces 83 and 145 and stopper 170 . When the contact brake operates and the output shaft 140 moves away from the puck motor 50, the piston 80 is also forced back.

About half of the disk motor side of the external thread 142 of the output shaft 140 is screwed into the internal thread 112 of the screw member 110, and the remaining half of the external thread 142 protruding from the screw member 110 toward the direction away from the disk motor is screwed. Screwed into the aforementioned lock nut 120, thus locking the screw member 110, the input rod 130 and the output shaft 140 integrally. As a result, when the brake cable 150 is pulled by the brake operation, the input rod 130, the screw member 110 and the output shaft 140 rotate together, and advance toward the disc motor due to the screw fit between the external thread 111 and the internal thread 101, This pushes the piston 80 at the end of the output shaft 140 .

The lock nut 120 is also used to adjust the tension of the brake cable 150 and to adjust the brake clearance according to the pad wear of the friction pad 60 . For example, when the tension of the brake cable 150 is adjusted, the lock nut 120 is first loosened, and the output rod 130 is moved in either direction along its rotation path by using the screw member 110 as a fulcrum, and the tension of the brake cable 150 is adjusted, and then the lock nut 120 is tightened again. When the braking gap between the side of the disc motor 50 and the lining of the friction pad 60 increases by a certain amount due to repeated braking operations, the lock nut 120 is similarly loosened once, and then the lock nut 120 is loosened once by manipulating the button 143. Push the output shaft 140 toward the disc motor 50 to push the friction pad 60 at the piston 80 at the end of the output shaft 140 and properly set the brake clearance. Finally, tighten the lock nut 120 again.

Thus, in the above-described embodiment, as the brake cable 150 is pulled by the driver's brake operation, the input rod 130 rotates away from the solid line position in FIG. 1 to the dashed line position. Simultaneously, the screw member 110 , the output shaft 140 and the input rod rotate together and move toward the disc motor 50 . This causes the output shaft 140 with its piston 80 to be pushed against the disc motor until the friction pad 60 on the active part side is pressed against the side of the disc motor 50 .

This results in a counter braking force that advances the caliper body 40 toward the active portion while being guided by the slide pins 30, 30, and the reactive portion 42 presses the friction pad 60 on the reactive portion side against the other side of the disc motor 50. side, thereby performing brake operation.

When the brake operation is released, the individual components operate in the reverse order of the brake operation until the pressure applied to the friction pads 60, 60 is released. Specifically, on the action portion 41 side, the screw member 110 , the output shaft 140 and the input rod 130 move together away from the disk motor 50 . The piston 80 locked by the stopper 170 is then forced back away from the disc motor 50 . As a result, the disk motor 50 starts to rotate, and a lateral force is generated between both sides of the disk motor 50 and the friction pads 60 , 60 opposing thereto, so that the two friction pads move away from the disk motor 50 . Uneven wear of the pads of the two friction pads can thus be prevented as far as possible.

In addition to normal braking operations as described above, when the vehicle is continuously stopped on a slope, the disc motor 50 acting on the friction pads 60, 60 generates traction torque in the direction that the vehicle is pulled down the slope. Simultaneously, a traction torque acts on the piston 80 adjacent to the friction pad 60 on the active part side, thus causing the piston 80 to tilt relative to the disc axis in the direction of disc rotation, the piston 80 being supported by the abutment surfaces 83 and 145 Adjacent to the output shaft 140 and elastically locked by the stopper 170 , the piston 80 simultaneously pushes and deforms the stopper 170 and makes its abutment surface 80 slide on the abutment surface 145 of the output shaft 140 .

The tractive moment acting on the friction pad 60 therefore only tilts the piston 80 while the postures of the output shaft 140 and the screw member 110 are maintained along the disc axis. Therefore, it is possible to avoid applying too much load, and to avoid the inner thread 112 and the outer thread 142 connecting the screw member 110 and the output shaft 140, and the multi-start inner thread and the outer thread 101 connecting the sleeve nut 100 and the screw member 110. and 111 wear. Therefore, the durability of the turnbuckle 100, the screw member 110, and the output shaft 140 can be improved. In addition, it is possible to avoid interference with the brake operation that may occur when a bias load is applied to the output shaft 140 or the screw member 110 .

Hereinafter, another preferred embodiment of the present invention will be described with reference to FIG. 4 , wherein descriptions of similar or identical elements or parts denoted by the same reference numerals as in FIGS. 1-3 are omitted.

In this embodiment, the portion of the output shaft 140 in FIGS. 1-3 extending from the large diameter portion 144 to its front end is cut away, omitting the stopper 170 at the front end of the shaft.

Specifically, the piston 200 axially movable along the disk axis and accommodated in the receiving hole 46 is formed by a cylinder with a bottom surface and a bottom wall 201 . The bottom wall 201 is formed with a spherical concave abutment surface 202 on its side facing away from the disc motor. The output shaft 210 for pushing the piston 200 toward the disc motor 50 includes a shaft portion 211 extending from the turnbuckle 100 to the piston 200, and protruding from the turnbuckle 100 away from the disc motor 50 with a large shaft formed continuously therewith. Diameter male thread 2 12. The external thread 212 is formed with a button 213 at its distal end. The shaft portion 211 is formed with a flange-shaped large-diameter portion 214 at its front end. The large diameter portion 214 is provided with a spherically expanded abutment surface 215 on one side of the disc motor 50 . The piston 200 is thus made to cooperate with the output shaft 210 only by means of the abutment between the abutment surface 202 of the piston 200 and the abutment surface 215 of the output shaft 210 .

Therefore, in the present embodiment, the traction moment acting on the friction pad 60 is such that the piston 200 is tilted, while the postures of the output shaft 210 and the screw member 110 with respect to the direction of the disc axis are maintained, thus avoiding the screw member 110. The internal thread 112 and the external thread 142 of the output shaft 210, or the internal thread 101 of the turn nut 100 and the external thread 111 of the screw member 110 are subjected to excessive load and wear.

In the embodiment of Fig. 4, the abutment surface of the output shaft may be formed by shaving its end face into a spherical shape of its shaft diameter.

Additionally, the spherical abutment surfaces of the piston and output shaft may be reversed from the above-described embodiments. That is, the abutment surface of the piston may be formed in a convex shape, while the abutment surface of the output shaft may be formed in a concave shape. Alternatively, the two spherical abutment surfaces may be formed convexly. The stopper fitted at the front end of the output shaft may include not only the wave washer as described in the above embodiment, but also spring washers or other types of elastic materials such as flexible or rigid resin and rubber.

In the above-described embodiments, the turnbuckle provided consecutively with the receiving hole for receiving the piston constitutes part of the receiving hole of the present invention. Therefore, the turnbuckle in the above embodiment can be omitted, and the screw part that can be arranged inside the receiving hole can be directly screwed into the receiving hole. Furthermore, the receiving hole (or turnbuckle) does not have to be screwed into the screw part with multi-start threads.

Claims (2)

1. A mechanical disc brake for a vehicle comprising a caliper body with an active portion provided on one side of a disc motor in which a receiving hole is formed along the side of the disc electrode A cylindrical piston with a bottom surface is movably accommodated along the disc shaft, the screw part is screwed into the inner wall of the receiving hole on the side away from the disc electrode, an output shaft is arranged between the screw part and the piston, wherein the output shaft and the screw member advance together toward the disc motor as the input rod rotates, thereby pressing a friction pad against the disc motor by the piston abutting the output shaft One side of the mechanical disc brake is characterized in that one of the abutment surfaces of the output shaft and the abutment surface of the piston which adjoin each other is formed as a spherical protrusion, and the other is formed as a spherical depression or protrusion rise. 2. The mechanical disc brake according to claim 1, wherein a large-diameter portion is formed on the output shaft at the position of the bottom wall of the piston relative to the distal end side of the disc motor, and on the large-diameter portion A protruding portion is formed, the large-diameter portion and the piston bottom wall have opposing surfaces formed by the abutment surface, a through hole is formed in the piston bottom wall along the disk axis, the protruding portion passes through the through holes and protrude toward the disc motor above the piston, wherein the protruding portion is fitted with an elastic stopper so that the bottom wall of the piston is bounded by the stopper and the large diameter of the output shaft Partial elasticity remains.

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