JPH0736193Y2 - Disc brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a disc brake incorporating a handbrake actuation mechanism.

(Prior Art) Conventionally, as an example of the above-mentioned disc brake, there is one as shown in FIG. 7 to FIG. In the figure, a carrier 1 is fixed to a non-rotating part of a vehicle on one side of a disc 2 which rotates with the wheels of the vehicle. The carrier 1 slidably supports a pair of friction pads 3 and 4 and calipers 5 arranged on both sides of the disk 2. A cylinder 6 is formed in the caliper 5, and two pistons that are engaged with each other by a gap adjusting member (not shown) are housed in the cylinder 6. An inner piston (not shown) directly displaces the friction pad 3 by supplying pressure oil between both pistons and presses it against one side surface of the disk 2. A cam shaft 9 is connected to the outer piston 7 shown in FIG. 9 via a connecting rod 8, and the two pistons are axially displaced according to the rotation of the cam shaft 9. The friction pad 3 is adapted to be pressed against one side surface of the disk 2.

The camshaft 9 is connected to a handbrake lever (not shown) in the driver's seat via a cable 10 and has a circular arc-shaped engaging portion 11 and a protrusion 12 connected to the engaging portion 11 on the peripheral portion. The formed brake lever 13 is attached, and a part of the brake lever 13 projects above the brake lever 13. A coil-shaped return spring 15 is fitted on the protruding portion 14 of the cam shaft 9. The return spring 15 has one end locked to the brake lever 13 and the other end locked to a stopper 16 implanted in the caliper 5, and constantly urges the brake lever 13 in the arrow A direction.

A flange 17 is formed on the stopper 16 so as to be sandwiched between the engaging portions 11 of the brake lever 13. This flange 17 prevents the brake lever 13 and the cam shaft 9 from coming off, and is interposed between the return spring 15 and the brake lever 13 to separate them from each other to avoid their contact. .

In this disc brake, when the hand brake lever on the driver's seat is pulled, the brake lever 13 and the cam shaft 9 are rotated in the forward direction (direction of arrow C), and the two pistons are displaced in the axial direction of the cylinder via the connecting rod 8. As a result, the friction pad 3 is pressed against one side surface of the disk 2, and the reaction pad at this time presses the friction pad 4 against the other side surface of the disk 2. As a result, the function as a parking brake is achieved. Then, when the operation of the handbrake lever is released, the brake lever 13 is rotated in the direction of arrow A by the spring force of the return spring 15, the protrusion 12 abuts the stopper 16, and the rotation is stopped. Is returned to the state of.

When the brake pedal in the driver's seat is depressed and pressure oil is supplied from the brake master cylinder to both pistons in the cylinder 6, the inner piston in the cylinder 6 directly displaces the friction pad 3 and presses it against one side of the disc 2. By this reaction force, the friction pad 4 is pressed against the other side surface of the disc 2 and a foot brake function is obtained.

(Problems to be solved by the invention) By the way, in the above-mentioned disc brake, the operation of the hand brake lever is released and the brake lever 13 is moved to the arrow A.
When the brake lever 13 is rotated in a direction, an upward force (arrow D direction) may act on the brake lever 13. In such a case, the protrusion 12 contacts the side surface of the flange 17 and the brake lever 13
Does not return smoothly, and in particular, when the sliding contact surface between the flange 17 and the brake lever 13 is worn, the side surface of the protrusion 12 comes into contact with the side when returning, and there is a problem in that it comes into contact.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a disc brake capable of reliably returning the brake lever to the original stopped state when the operation of the hand brake lever is released.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cam shaft rotatably provided on a caliper with a part thereof protruding, and a cam shaft attached to the cam shaft. A rotating brake lever, which is coiled and is located above the brake lever and is fitted to the protruding portion of the cam shaft, one end of which is locked to the brake lever and the other end of which is located on the caliper side. The brake lever has a return spring that applies a rotational force in the return direction about the cam shaft to the brake lever, and a flange that is interposed between the return spring and the brake lever, and is fixed to the caliper. A bar-shaped stopper that restricts rotation of the brake lever in the return direction by contact with a protrusion formed on the brake lever, and an end portion of the protrusion that engages with the flange of the brake lever. Wherein the set lower than the end face.

(Operation) Since the present invention is configured as described above, when the pulling operation of the hand brake lever is stopped and the brake lever is rotated by the return spring, even if the upward force acts on the brake lever, the flange and the protrusion A gap is formed between the upper end surface of the portion and the protrusion to avoid contact with the side surface of the flange.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In the figure, reference numeral 30 denotes a caliper, which has a cylinder portion 31 to be described later and a lever guide 32 projecting from the cylinder portion 31 so as to extend rearward. The caliper 30 is slidably supported by the carrier 34 by the two slide pins 33. The carrier 34 is fixed to the non-rotating part of the vehicle on one side of the disk 35 which rotates with the wheels of the vehicle. The carrier 35 has a disc 35.
A pair of friction pads 36, 37 arranged on both sides of the is supported slidably. The arm portion 38 of the caliper 30 extends above the disc 35 and the friction pads 36, 37 and engages with the friction pad 37 at the other end. Caliper
A cylinder 39 is formed on the cylinder portion 31 of the 30.
Two pistons are stored in 39. The two pistons are engaged with each other by a gap adjusting member (not shown) arranged between the two pistons. The piston 40 shown in FIG. 1 is the outer piston, and the other inner piston (not shown) can directly actuate the friction pad 36.

A cam shaft 41 is provided on the caliper 30 so as to be rotatable in a direction orthogonal to the axis of the cylinder 39. Camshaft 41 and piston
A connecting rod 42 is provided between the connecting rod 42 and the shaft 40, and the rotational movement of the cam shaft 41 is transmitted as the axial movement of the piston 40 via the connecting rod 42. A part of the cam shaft 41 protrudes outside the caliper 30, and the protruding portion 43 has the cam shaft 41
A brake lever 44 for rotating the is attached.

The brake lever 44 has an engaging portion 45 having an arcuate outer peripheral shape formed on the peripheral edge portion thereof, and a protruding portion 46 connected to the engaging portion 45 and protruding. The upper end surface 47 of the protrusion 46 is set lower than the upper end surface 48 of the engaging portion 45. Further, a chamfer 49 is formed on the engaging portion 45. Brake lever
44 is a stopper in which the protrusion 46 is planted in the caliper 30.
By making contact with the shaft 51 of the shaft 50, rotation of the return spring 52, which will be described later, in the direction of arrow A is restricted. The brake lever 44 is forged, and the protrusion 46 is formed by pressing during forging. For this reason,
When the upper end surface 47 of the protrusion 46 is set lower than the upper end surface 48 of the engaging portion 45, the production efficiency does not decrease.

A cable 54 is connected to the tip 53 of the brake lever 44,
The cable 54 is inserted into a hole 56 formed in the tip portion 55 of the lever guide 32 and connected to a handbrake lever (not shown) in the driver's seat.

A coil-shaped return spring 52 is fitted to the protruding portion 43 of the cam shaft 41 so as to be positioned above the brake lever 44. The return spring 52 has a lower end 57 which is a stopper 50.
Further, the upper end portion 58 is locked to the brake lever 44, and the brake lever 44 is always biased in the direction of arrow A.

The stopper 50 has a rod shape and is planted in the vicinity of the cam shaft 41 of the caliper 30. In the middle of the shaft 51 of the stopper 50,
A flange 59 is formed so as to be sandwiched between the lower end portion 57 of the return spring 52 and the engaging portion 45 of the brake lever 44.
A chamfer 60 is formed on 59. This flange 59 prevents the brake lever 44 and the cam shaft 41 from coming off,
Further, since it is interposed between the return spring 52 and the brake lever 44, they are separated from each other to avoid their contact.

The operation of the disc brake configured as described above will be described.

First, when the brake operation is not performed, the stopper 50 contacts the protrusion 46 of the brake lever 44 and stops the brake lever 9 from rotating against the biasing force of the return spring 52.

When the handbrake lever on the driver's seat is pulled in this state, the cable 54 moves in the direction of arrow B. Along with this movement, the brake lever 44 has its engaging portion 45 flanged.
While being pressed by 59, the arrow C acts against the urging force of the return spring 52.
Is rotated in the direction. At this time, since the chamfers 49 and 60 are formed in the engaging portion 45 of the brake lever 44 or the flange 59, the ends of the chamfers 49 and 60 do not bite into the mating side. As a result, the brake lever 44 rotates smoothly. With the rotation of the brake lever 44 in the direction of the arrow C, the cam shaft 41 is rotated in the same direction to displace the piston 40 in the axial direction, thereby fulfilling the function as a parking brake.

When the pulling operation of the hand brake lever is stopped in this state, the brake lever 44 is pressed by the spring force of the return spring 52.
Is rotated in the direction of arrow A, but even if an upward force (direction of arrow D) acts on the brake lever 44 at this time, a gap is formed between the flange 59 and the upper end surface 47 of the protrusion 46. As a result, the protrusion 46 is prevented from coming into contact with the side surface of the flange 59, and the brake lever 44 is smoothly rotated in the arrow A direction to return to the original stopped state.

When used as a foot brake, the brake pedal at the driver's seat may be depressed to supply pressure oil from the brake master cylinder to both pistons in the cylinder 39. As a result, the inner piston in the cylinder 39 directly displaces the friction pad 36 and presses it against one side of the disk 35, and the caliper 30 receives this reaction force and displaces in the opposite direction to the inner piston and the friction pad 37. To the other side of the disc 35. This provides a braking effect.

(Effects of the Invention) As described above, it is possible to prevent the protrusion from coming into contact with the side surface of the flange when the pulling operation of the hand brake lever is stopped and the brake lever is rotated.
The brake lever is reliably rotated to return to the original stopped state. Therefore, it is possible to provide a disc brake with improved reliability of the handbrake operation.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention.
2 is a sectional view taken along the line I--I of FIG. 2, FIG. 2 is a plan view showing a brake lever of a disc brake according to an embodiment of the present invention, and FIG. 3 is a perspective view showing the disc brake. 4 is a plan view showing the protrusion of the brake lever of FIG. 2, FIG. 5 is a sectional view taken along the line VV of FIG. 4, and FIG. 6 is a direction of the line VI-VI of FIG. FIG. 7 is a perspective view showing an example of a conventional disc brake, FIG. 8 is a plan view showing the same disc brake, and FIG. 9 is a sectional view taken along the line IX-IX in FIG. . 31 …… Caliper, 41 …… Cam shaft, 43 …… Projection part, 44…
… Brake lever, 45 …… engagement part, 46 …… projection part, 47…
… Upper surface, 48 …… Upper surface, 50 …… Stopper, 52 …… Return spring, 59 …… Flange.

Claims (1)

[Scope of utility model registration request] 1. A cam shaft rotatably provided on a caliper with a part thereof protruding, a brake lever attached to the cam shaft for rotating the cam shaft, and a brake lever having a coil shape. Located on the upper side of the cam shaft and fitted into the protruding portion of the cam shaft, one end of which is locked to the brake lever and the other end of which is locked to the caliper side, and the brake lever is centered on the cam shaft. The brake lever has a return spring that applies a rotational force in the return direction, and a flange that is interposed between the return spring and the brake lever and that is fixed to the caliper and a protrusion formed on the brake lever comes into contact with the brake lever. And a rod-shaped stopper for restricting rotation in the return direction of the brake lever, and the end face of the protrusion is set lower than the end face of the engaging portion of the brake lever with the flange. Ki.