JPH0130662Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a disc brake device equipped with a mechanical actuation mechanism and used primarily in vehicles.

[Prior Art] Conventional disc brake devices of this type include, for example, those having a mechanical operating mechanism that performs braking by converting rotational force into linear force using a cam plate with ramp grooves and steel balls. be.

The input lever is rotated by operating the brake operating lever or the brake operating pedal, and the position of the steel ball that is rotatably held in the ramp groove formed on the opposing surface of the input lever and the cam plate is adjusted between the two ramps. The cam plate is moved to a shallow position in the groove, and the movable friction pad is pushed toward the brake disc via a piston that is movably disposed on the friction pad side of the cam plate to perform a braking action. In this disc brake device, in order to restrict the tilting of the friction pad during braking operation and the movement in the rotational direction of the brake disc due to braking torque, the friction pad is formed into a disc shape and thick. There was one in which a piston was movably disposed within a guide portion such as a cylinder into which a piston was movably inserted.

[The problem that the invention attempts to solve]

Therefore, in the above-described disc brake device, the guide portion of the caliper that guides the movement of the piston also guides the movement of the friction pad on the movable side, so the length of the guide portion depends on the allowable amount of wear of the friction pad. The corresponding length and bearing area of the friction pad are required, and the length of this guide becomes longer, leading to an increase in the size and weight of the caliper, and it takes time to replace the friction pad on the movable side. In the meantime, a problem arose.

In addition, the friction pads used must have a thick disk shape on the movable side that is pushed by a piston, etc., and have a special shape different from normal friction pads, which limits the braking area of the friction pads. In addition, the torque receiving part on the side surface of the friction pad on the movable side that slides against the inner periphery of the guide part tends to wear unevenly, and the shapes of the friction pads on the movable side and the fixed side are different, making it difficult to compatibility. There were some inconveniences, such as not having one.

This idea was created in view of the problems mentioned above.
The object of the present invention is to provide a disc brake device in which the replacement work of friction pads is easy, the weight of the caliper is reduced, and friction pads of a general shape can be used.

[Means for solving problems]

As a means to solve the above problems, in the present invention, a friction pad provided on the caliper,
In a disc brake device having a mechanical operating mechanism that presses and presses against a brake disc by rotating an input lever to perform braking, a cylindrical part is attached to the caliper so as to be perpendicular to the pressing surface of the friction pad. A sleeve-shaped piston is disposed within the guide portion so as to be movable in the axial direction of the guide portion, and a shaft member having a large-diameter pad pushing portion formed at the tip thereof is arranged such that the tip side thereof is the friction pad side. is inserted into the sleeve-shaped piston so that the rear end side extends toward the anti-friction pad side of the piston,
An input lever that integrally pushes and drives the piston and this shaft member toward the friction pad is locked to the extending portion of the shaft member, and an annular inner circumferential edge portion that is locked to the shaft member. , a dust boot having an outer circumferential edge that is locked to the outer circumferential surface of the piston, and an annular wiper portion that slides on the inner circumferential surface of the guide portion closer to the friction pad than the outer circumferential edge; It is characterized by being arranged so as to close the opening on the friction pad side of the part.

[Effect]

With this configuration, the friction pad can be easily attached and detached, and the caliper is lightweight. In addition, since the annular wiper part formed on the outer periphery of the dust boot together with the piston slides on the inner circumferential surface of the guide part, the wiper part scrapes off foreign matter such as dirt and sand adhering to the guide part, and also wipes off foreign matter such as sand and dirt attached to the guide part. Prevent foreign matter from entering.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a mechanically actuated disc brake device for a motorcycle equipped with an automatic braking gap adjustment device will be described below with reference to the drawings.

The caliper 1 includes a caliper part 2 consisting of an action part 2a, a reaction part 2b, and a bridge part 2c that connects the action part 2a and the reaction part 2b, and a caliper part 2 that is formed separately from the caliper part 2 and is located on the action part 2a side. and a housing part 4 which is connected to the housing part 4 by a bolt 3 and houses a mechanical operating mechanism therein, and a bracket 7 which straddles the disc 5 by the bridge part 2c and is attached to a fixed part on the vehicle body side by sliding pins 6, 6. The disk is mounted so that it can move in the axial direction.

Moreover, friction pads 8 and 9 are provided between the acting part 2a and the reaction part 2b of the caliper part 2 on its back plate 8.
A, 9a are guided movably in the disk axial direction by a hanger pin 10 on one side and a guide step 7a formed on the bracket 7 on the other side, and are arranged so as to sandwich the disk 5.

A cylindrical guide portion 11 is formed in the acting portion 2a of the caliper portion 2 so as to be substantially perpendicular to the back plate 8a of the friction pad 8. An accommodating part 12 of a mechanical actuation mechanism having a cylindrical shape with a bottom is disposed opposite to the guide part 11, and an input lever 13 is rotatably covered between the accommodating part 12 and the operating part 2a. Cover parts 14 are formed in communication with each other, and the cover parts 14 further include a brake wire (the end of which is hooked to the tip of the input lever 13, and which pulls and rotates the input lever 13). A wire extension hole 15 is provided to extend the wire (not shown).

On the other hand, a sleeve-shaped piston 16 having a female thread formed on the inner periphery is fitted into the cylindrical guide portion 11 so as to be movable in the disk axial direction. A pipe-shaped adjustment nut 18 has a male thread formed on the outer periphery of one end 18a of the piston 16.
The piston 16 is screwed into a female thread formed on the inner circumference of the piston 16.
The adjusting nut 18 is attached to the anti-friction part side of the piston 16 so as to move together with the adjusting nut 16, and the other end 18b of the adjusting nut 18 extends to the vicinity of the bottom 12a in the receiving portion 12 of the housing portion 4. .

Further, an adjustment bolt 19 is threadably inserted into a female thread formed on the inner circumference of the adjustment nut 18.
At the tip of the piston 16 extending toward the friction pads 8 and 9, there is a pad pushing part 19 in the shape of a large diameter disc.
a, and the end face of the pad pushing portion 19a is placed in contact with the back plate 8a of the friction pad 8 on the movable side.

Further, the end portion 18b of the adjusting nut 18
A ratchet wheel 20 is rotatably engaged with the ratchet wheel 20, and the ratchet wheel 20 is biased toward the end portion 18b by a conical coil spring 21 compressed between the bottom portion 12a of the housing portion 12. At the same time, rotation is transmitted to the rear end of the adjusting bolt 19 by a rotating shaft 20a protruding from the center on the adjusting bolt 19 side.

Furthermore, on the outer periphery of the adjusting nut 18,
The input lever 13 is rotatably supported by loosely inserting a mounting hole formed on the base end thereof, and a cam plate 22 is provided on the piston 16 side of the input lever 13, and its outer edge is connected to the housing part. The input lever 13 and the cam plate 22 are provided with ramp grooves 13a and 22a on opposing surfaces thereof. are formed facing each other at a plurality of locations, and both of these opposing lamp grooves 13
A steel ball 23 is rollably sandwiched between a and 22a.

In this way, the adjusting nut 18, adjusting bolt 19, and piston 16 are assembled so as to move together, with the piston 16 portion being guided by the guide portion 11, and the adjusting nut 18 portion being supported by the cam plate 22. Eccentricity during axial movement is prevented.

In addition, the input lever 13 is restricted from moving toward the cam plate side by bringing its anti-cam plate side into contact with the mouth edge of the accommodating portion 12 via a thrust bearing, and is pulled by the brake wire. When the input lever 13 rotates, the steel ball 23 rolls and moves to the shallow part of both lamp grooves 13a, 22a, widening the distance between the input lever 13 and the cam plate 22. The piston 16 is driven through the piston 16, and the pad pushing part 19a at the tip of the adjusting bolt 19, which moves together with the piston 16, presses the movable friction pad 8 against one side of the brake disk 5, and The entire caliper 2 supported by the sliding pins 6, 6 is moved toward the acting part 2a side by force, and the reaction part 2b of the caliper 2 presses the other friction pad 9 against the other side of the brake disc 5 to create both frictions. Braking is performed by squeezing the brake disc 5 between the pads 8 and 9.

The opening on the friction pad 8 side of the cylindrical guide portion 11 is covered with a wiper-type dust boot 24 made of an elastic material such as rubber.
This wiper-type dust boot 24 has its outer circumferential edge engaged with the outer circumferential side of a piston 16 that is movably fitted into the guide section 11, and also slides in pressure contact with the inner circumferential surface of the guide section 11. an annular seal portion 24a, and a guide portion 1 from the seal portion 24a.
a cylindrical portion 24b extending along the inner circumferential surface of the guide portion 11 toward the mouth edge side of the guide portion 11; and an annular wiper portion 24c formed thickly in the outer circumferential direction at the tip of the cylindrical portion 24b and protruding from the cylindrical portion 24b. And this wiper part 24
A locking portion 24d is bent at an approximately right angle toward the center from c, and a locking portion 24d that locks the adjusting bolt 19 is formed on the inner circumferential edge thereof, and the width of the locking portion 24d is adjusted to match the guide portion 1.
1 and the locking portion of the adjusting bolt 19.
With the elasticity of the dust boot 24 being used to bend the closing portion 24e, the locking portion 24d on the inner peripheral side is attached to the adjustment bolt 1.
The large-diameter pad 9 is locked at the base of the pushing part 19a, and the resilient force of the closing part 24e urges the annular wiper part 24c toward the outer circumferential direction, so that the wiper part 24c is pressed against the inner circumferential surface of the guide part 11. It is arranged so that it can slide in the state that it is held.

This wiper-type dust boot 24 prevents dirt, water, etc. from entering the inside of the sleeve-shaped piston 16 by means of the blocking portion 24e to ensure smooth threading of the adjuster bolt 19, and also prevents dirt or water from entering into the inside of the sleeve-shaped piston 16. As the piston 16 moves, it slides within the guide portion 11, and the seal portion 24a prevents dirt, water, etc. from entering the housing 4 of the caliper 1, and the wiper portion 24c
This removes dirt and the like adhering to the inner circumferential surface of the guide portion 11 and prevents dirt and the like from getting caught in the sliding surface.

Reference numeral 25 denotes an adjustment lever which is rotatably mounted on the outer periphery of the adjustment nut 18 in the housing portion 4 together with the adjustment sheet 26. The adjustment lever 25 is provided with a feed pawl 25a, and this adjustment lever The lever 25 has one end connected to the input lever 13 and the other end connected to the adjustment seat 2.
Coil springs 27 each locked and contracted at 6.
The input lever 13 is biased in the rotational direction of the braking operation, and is also biased toward the bottom 2a of the storage portion 12, causing the feed pawl 25a to constantly mesh with the meshing teeth of the ratchet wheel 20, and the end of the adjuster nut 18. Part 1
The pawl 28a of the stopper lever 28, which is engaged with the stopper lever 8b, is always engaged with the meshing teeth of the ratchet wheel 20, and is rotatably provided on the rear end 18b of the adjuster nut 18 when the friction pads 8, 9 are worn beyond a predetermined level. The ratchet wheel 20 is rotationally driven, and the adjuster nut 18 is rotated.
Rotatably drive the adjusting bolt 19 screwed into the
By screwing it out and extending the screwed state, the return position of the movable friction pad 8 can be set to the brake disc 5.
automatically adjusts the braking gap.

Further, 7b is a support part for the axle shaft (not shown) of the bracket 7, on which the caliper 1 is slidably provided by sliding pins 6, 6, and 7c is a support part for a fixed part on the vehicle body side such as a front fork. Department.

By configuring the disc brake device as described above, friction pads having a general shape can be used, and the friction pads can be easily replaced by removing the friction pads from the hanger pins that suspend them. Can be removed and replaced.

Furthermore, although this embodiment has described a mechanically actuated disc brake device for a motorcycle equipped with an automatic braking gap adjustment device, other types of disc brakes such as a type that has both a hydraulic actuating mechanism and a mechanical actuating mechanism have been described. The present invention can be suitably implemented in a brake system or a disc brake system for four wheels, and a manual brake gap adjustment device may be provided in place of the automatic brake gap adjustment device.

[Effects of the invention] As explained above, the invention has a sleeve-shaped piston movable in the axial direction within the cylindrical guide part formed in the caliper, and a large diameter pad pushing part is formed at the tip. The shaft member is inserted into the piston so that the tip side faces the friction pad side, the rear end side extends toward the side opposite to the friction pad of the piston, and the piston is pushed toward the friction pad by the extending portion of the shaft member. A dust boot that locks a dynamically driven input lever and closes an opening on the friction pad side of the guide portion is installed to lock the piston and the shaft member and move together with the piston.
Replacing the friction pads becomes easier, and the bearing area of the guide section that was previously required to guide the movement of the friction pads on the movable side is no longer required, making it possible to shorten the length of the dust boot and reduce the weight of the caliper. be able to. In addition, since the annular wiper part formed on the outer periphery of the dust boot slides on the guide part together with the piston, the wiper part can scrape off foreign matter such as earth and sand that has adhered to the guide part and prevent it from reaching the sliding surface. It can prevent dirt and sand from getting caught in it, and it can also prevent dirt and water from entering the piston side.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a cross-sectional front view of Fig. 3 showing the caliper, and Fig. 2 is a front view of the caliper.
The figure is a perspective view of the dust boot, and FIG. 3 is a side view showing the appearance of the caliper attached to the bracket. 1... Caliper, 2... Caliper part, 2a...
Acting part, 4 is housing part, 5...brake disc, 7...bracket, 8, 9...friction pad, 10...hanger pin, 11...guide part,
DESCRIPTION OF SYMBOLS 12... Accommodation part of mechanical actuation mechanism, 13... Input lever, 13a... Lamp groove, 14... Cover part, 16... Piston, 17... Braking gap automatic adjustment device, 18... Adjustment nut, 19... ... Adjustment bolt, 20 ... Ratchet wheel, 22 ... Cam plate, 22a ... Lap groove, 23 ... Steel ball, 2
4... Wiper type dust boot, 24a... Seal part, 24c... Wiper part.

Claims (1)

[Scope of utility model registration request] In a disc brake device that has a mechanical actuation mechanism that presses a friction pad provided on the caliper by rotating an input lever and presses it against a brake disk to perform braking, the friction pad is pressed perpendicular to the pressing surface of the friction pad. A shaft in which a cylindrical guide part is formed in the caliper, a sleeve-shaped piston is disposed within the guide part so as to be movable in the axial direction of the guide part, and a large diameter pad pushing part is formed at the tip. The member is inserted into the sleeve-shaped piston so that the leading end side faces the friction pad side, the rear end side extends toward the side opposite to the friction pad side of the piston, and the piston and this shaft are attached to the extending portion of the shaft member. An annular inner peripheral edge that locks an input lever that integrally pushes and drives the member toward the friction pad and is locked to the shaft member, and an outer peripheral edge that locks to the outer peripheral surface of the piston. and an annular wiper portion that slides on the inner circumferential surface of the guide portion on the friction pad side side of the outer circumferential edge portion, and is disposed so as to close the friction pad side opening of the guide portion. A disc brake device characterized by: