CN102213283B - Brake drum cover structure of drum type brake - Google Patents

Abstract

The invention provides a brake drum cover structure of a drum brake. In drum brakes, by intensively reinforcing the portion of the drum cover supporting the drum brake mechanism that receives the greatest force, it is possible to significantly reduce the weight while maintaining the desired rigidity of the brake cover. In the brake drum cover (7), first and second ribs (50, 51) are arranged on the inner surface of the brake drum cover (7), and the first and second ribs (50, 51) Respectively connect the support bearing portion (20) supporting a pair of brake shoes (24) and the opposite two points (P1, P2) of the outer periphery of the brake drum cover (7) into one body, and the pair of brake shoes (24) The cam bearing portion (21) which supports the active brake cam and the two opposing points (P3, P4) on the outer peripheral edge of the brake drum cover (7) are integrally connected.

Description

Drum cover construction for drum brakes

technical field

The present invention relates to a brake drum cover structure for supporting a drum brake mechanism of a drum brake for a vehicle, mainly for a motorcycle.

Background technique

Conventionally, drum brakes for motorcycles and the like have been configured to have: a brake drum that is formed on a hub of a wheel and accommodates a drum brake mechanism; The open brake drum cover is braked by contacting or separating the linings of a pair of brake shoes of the drum brake mechanism supported on the brake drum cover with respect to the brake disc on the inner peripheral surface of the brake drum. However, in this drum brake, there is known a structure in which ribs are provided on the inner surface of the drum head portion of the brake drum (refer to Patent Document 1 described later).

Patent Document 1: Japanese Patent No. 3640659

However, since a braking force acts on the drum head of the drum brake, it is necessary to ensure high rigidity, and in the structure of Patent Document 1, the ribs contribute to reinforcement of the drum head. On the other hand, in response to recent environmental problems, it is desired to maintain or improve the performance of each component while reducing its weight, and this desire is also the same for brake drum covers.

Contents of the invention

The present invention is made in view of this situation, and its purpose is to provide a novel brake drum cover structure of a drum brake, which can intensively reinforce the part of the brake drum cover subjected to a high load, and maintain its desired Achieving a significant reduction in weight while maintaining high rigidity satisfies the above expectations.

In order to achieve the above objects, the first feature is a drum cover structure for a drum brake, in which a drum brake mechanism is housed in a brake drum formed on a wheel hub, and a drum cover provided in a non-rotatable manner Covering the opening of the brake drum, the brake drum cover has: a support bearing part that supports a support shaft that can expand and contractably support a pair of brake shoes of the drum brake mechanism; and a cam bearing part that It supports a camshaft provided with a brake cam that expands and contracts the brake shoe, and a first rib and a second rib are integrally provided on the inner surface of the brake drum cover, wherein,

The first rib extends in the radial direction from the support bearing part, and connects the support bearing part and two points on the outer peripheral edge of the brake drum cover and the support bearing part into one body, and the second rib part extends from the support bearing part. The cam bearing portion extends in the radial direction and integrally connects the cam bearing portion and two points on the outer peripheral edge of the drum cover facing the cam bearing portion.

In order to achieve the above object, the second feature is that, in the structure described in claim 1, a third rib and a convex portion are integrally provided on the inner surface of the brake drum cover, wherein the third The rib connects one end of the first rib and one end of the second rib; the convex part is at the other end of the first rib and the other end of the second rib Between them, the bearing cylinder portion of the brake drum cover and its outer peripheral edge are connected radially.

In order to achieve the above object, the third feature is that, in the structure described in the technical solution 1 or 2, a fourth rib and a fifth rib are integrally provided on the inner surface of the brake drum cover, wherein the The fourth rib extends through the center of the brake drum cover in a radial direction, and connects one end of the first rib and the other end of the second rib into one body; the fifth rib Extending in a diametrical direction through the center, and integrally connecting the other end of the first rib and one end of the second rib.

The effect of the invention

According to the inventions described in various technical solutions, when the brake is working, the support bearing part and the cam bearing part of the brake drum cover that directly bear the braking force are concentrated and reinforced by the first rib part and the second rib part, which can greatly By increasing the rigidity of these bearing parts, even if the other parts of the drum cover are formed thinner, the rigidity required as a brake drum cover can be maintained, and the weight of the brake drum cover can be reduced. As a result, The performance of the drum brake can be improved, and the weight and cost of the drum brake itself can be reduced.

In addition, in particular, according to the second feature, the third rib connects one end of the first rib and one end of the second rib, and the convex portion is at the other end of the first rib and the second rib. Between the other ends of the brake drum cover, the bearing cylinder part and its outer peripheral edge are connected in the radial direction, thereby, the rigidity of the support bearing part and the cam bearing part can be further improved, and further improvement of the brake drum cover can be achieved. lightweight.

Furthermore, especially according to the third feature, the fourth rib integrally connects one end of the first rib to the other end of the second rib, and the fifth rib connects the other end of the first rib to the second rib. One end portions of the two ribs are integrally connected, whereby the rigidity of the support bearing portion and the cam bearing portion can be further increased, and further weight reduction of the drum head can be achieved.

Description of drawings

Fig. 1 is a side view of a front wheel portion of a motorcycle having a drum cover structure of a drum brake according to the present invention.

Fig. 2 is an enlarged sectional view taken along line 2-2 of Fig. 1 .

Fig. 3 is an enlarged sectional view taken along line 3-3 of Fig. 1 .

Fig. 4 is a sectional view taken along line 4-4 of Fig. 2 .

Figure 5 is an inside view of the drum brake mechanism with the brake drum cover removed.

Fig. 6 is an inside perspective view of the brake drum cover.

Explanation of reference signs

4 wheel hub

5 brake drum

6 drum brake mechanism

7 brake drum cover

7P drum cover

10 Bearing barrel

20 Support bearing part

21 Cam bearing part

23 Support shaft

24 brake shoe

30 brake cam

50 first rib

50A at one end

50B The other end

51 second rib

51A One end

51B The other end

52 Third rib

53 Fourth rib

55 convex part

P1, P2 Two points where the outer peripheral edge of the brake drum cover 7 is opposite to the supporting bearing part 20

P3, P4 Two points where the outer peripheral edge of the brake drum cover 7 is opposite to the cam bearing part 21

Detailed ways

Hereinafter, embodiments of the present invention will be specifically described based on examples of the present invention shown in the drawings.

In this embodiment, a drum brake having the drum cover structure of the present invention is applied to the front wheel of a motorcycle.

In FIG. 1 , the front wheel W is rotatably supported on the axle axis 2 a (see FIG. 2 ) via the axle 2 on the fork portion 1F of the front fork 1 which is steerably supported on the motorcycle. On the body frame of the front wheel W, an internally tensioned drum brake for braking the front wheel W is provided, and the drum brake has the drum cover structure of the present invention.

As shown in FIGS. 1 to 4 , the drum brake has: a brake drum 5 integrally provided on the wheel hub 4 of the front wheel W, a drum brake mechanism 6 accommodated in the brake drum 5 , and a cover. The brake drum cover 7 of the opening 5M of the brake drum 5 allows the engaging portion 9 of the front fork 1 to be slidably engaged in the radial groove 8 formed on the outer surface of the brake drum cover 7 , Therefore, the brake drum cover 7 cannot rotate relative to the brake drum 5 (refer to FIG. 3 ).

The axle 2 supported by the front fork 1 passes through a bearing cylinder 10 integrally formed at the center of the wheel hub 4 via a bearing 3 , and the front wheel W is rotatably supported between the forks 1F.

One axial end surface of the brake drum 5 has an opening 5M formed in a hollow cylindrical shape, and the drum brake mechanism 6 is housed in the hollow recess 5C. A brake disc 11 is wound around the inner peripheral surface of the brake drum 5 .

On the other hand, the brake drum cover 7 is formed in a disc shape, and has a shaft hole 15 in its center, and the axle 2 passes through a sleeve 16 fitted in the shaft hole 15 . In addition, the opening 5M of the brake drum 5 is covered by the brake drum cover 7, and the outer peripheral surface of the brake drum cover 7 is relatively rotatably engaged with the inner peripheral surface of the opening 5M of the brake drum 5 via a labyrinth seal 17. .

On the inner surface of the drum cover 7 , a tension-type drum brake mechanism 6 accommodated in the hollow recess 5C of the brake drum 5 is supported. On the drum cover portion 7P of the brake drum cover 7, at both outer ends on the diameter line L1-L1 (refer to FIG. 5 ) passing through the central axis of the brake drum cover 7, boss-shaped The bearing portion 20 and the cam bearing portion 21 are supported. The support bearing part 20 is integrally provided on the inner surface of the outer peripheral edge of the brake drum cover 7, and on the support shaft 23 supported by the support bearing part 20 along the support axis 23a, a circular arc shape is freely rotatably supported. To the base end of brake shoe 24,24. Furthermore, brake linings 25 , 25 that are capable of coming into contact with or separating from the brake disc 11 are bonded to the arcuate outer surfaces of the pair of brake shoes 24 , 24 , respectively. Between the bases of a pair of brake shoes 24, 24 and between the front ends thereof are respectively stretched brake return springs 26, 27 made of tension springs. The pair of brake shoes 24 , 24 are spring-pressed in a direction away from the brake disc 11 . The cam bearing part 21 is integrally provided on the inner surface of the outer periphery of the brake drum cover 7, and the cam shaft 29 is supported on the cam bearing part 21 to freely rotate along the cam axis 29a, and the cam shaft 29 and the cam bearing part An oil seal 45 is sandwiched between 21. An elliptical brake cam 30 is integrally provided at the inner end of the cam shaft 29 protruding into the hollow recess 5C. The free ends of the pair of brake shoes 24, 24 provided with cam brackets 31, 31 are relatively arranged on both sides of the cam surface of the brake cam 30, and the free ends of the pair of brake shoes 24, 24 pass through The elastic force of the brake return springs 26 , 27 is pressed against the cam surface of the brake cam 30 . In addition, the outer end of the camshaft 29 protrudes from the outer surface of the drum cover 7 to the outside, and comb-like teeth 32 are engraved thereon (see FIG. 1 ). Furthermore, the base end of the brake arm 34 is fixed to the outer end of the camshaft 29 by a bolt and a nut 36 . Between the base of the brake arm 34 and the brake drum cover 7, an arm return spring 35 made of a torsion coil spring is connected, and the elastic force of the arm return spring 35 will brake the arm 34 to the brake release position ( Figure 4 position) spring pressure. The brake arm 34 extends radially outward of the brake drum cover 7, and two brake cables 38, 39 are connected to the outer ends of the brake arm 34, which are respectively used for independent braking of the front wheel W and for joint braking of the front and rear wheels. (Refer to Figure 1). When one of these brake cables 38 and 39 is selectively pulled, the brake arm 34 can swing to the braking operation position. By the brake arm 34 swinging to the braking action position, the camshaft 29 rotates, and the brake cam 30 resists the elastic force of the brake return springs 26, 27 to make the pair of brake shoes 24, 24 move around the support shaft 23 in the direction of expanding diameter. By turning, the brake linings 25 and 25 on the outer peripheral surface are brought into frictional contact with the brake disc 11 on the inner peripheral surface of the brake drum 5, and the front wheel W can be braked.

In addition, by releasing the traction of the brake cable 38 (or 39), the brake arm 34 swings to the brake action release position by the elastic force of the arm return spring 35, the camshaft 29 rotates to the brake release position, and the pair of brake shoes 24, 24 are rotated to the reduced-diameter position by the elastic force of the brake return springs 26, 27, and the brake of the front wheel W is released.

However, the brake drum cover 7 in this embodiment is configured to maintain its high rigidity to reliably perform the braking operation, prevent the occurrence of squeaking during the braking operation, and achieve a significant reduction in weight.

As shown in Figures 5 and 6, on the inner surface of the drum cover part 7P of the brake drum cover 7, the two ends of the diameter line L1-L1 passing through the center of the brake drum cover 7 are respectively integrally formed with the The supporting bearing part 20 and the cam bearing part 21 are integrally formed with a linear first rib 50 and a linear second rib 51 respectively, wherein the first rib 50 extends radially from the supporting bearing part 20 Extend and combine the support bearing part 20 and the outer peripheral edge of the brake drum cover 7 with two points P1, P2 opposite to the support bearing part 20; the second rib 51 extends radially from the cam bearing part 21 and The cam bearing part 21 and the outer peripheral edge of the brake drum cover 7 are integrated with the two points P3 and P4 opposite to the cam bearing part 21, and the first rib part 50 and the second rib part 51 are clamped and passed The diameter line L1-L1 at the center of the movable drum cover 7 is substantially perpendicular to the other diameter line L2-L2 and extends substantially parallel to each other.

Furthermore, a third rib 52 and a convex portion 55 are integrally provided on the inner surface of the drum cover 7P of the brake drum cover 7, wherein the third rib 52 connects the one end 50A of the first rib 50 and the One end 51A of the second rib 51 , the convex portion 55 is between the other end 50B of the first rib 50 and the other end 51B of the second rib 51 , and is radially connected to the stopper. The bearing cylinder portion 10 of the drum cover 7 and the outer peripheral edge of the brake drum cover 7 . Also, the third rib 52 extends substantially parallel to the diameter line L1-L1, and the convex portion 55 extends along the other diameter line L2-L2. The groove 8 is formed on the outer surface side of the convex portion 55 (see FIG. 3 ).

Moreover, in addition, a fourth rib 53 and a fifth rib 54 are integrally provided on the inner surface of the drum cover 7P of the brake drum cover 7 , wherein the fourth rib 53 passes through the center of the brake drum cover 7 along the Extends in the radial direction, and connects one end 50A of the first rib 50 and the other end 51B of the second rib 51 into one body, and the fifth rib 54 passes through the center of the brake drum cover 7 along the diameter direction, and connect the other end 50B of the first rib 50 and one end 51A of the second rib 51 into one body, and the fourth rib 53 and the fifth rib 54 pass through the brake drum cover The centers of 7 cross each other.

In addition, on the inner surface of the drum head portion 7P of the brake drum head 7, three auxiliary ribs 56, 57, 58 on the side connecting the outer peripheral portion of the support bearing portion 20 and the outer peripheral portion of the bearing cylinder portion 10 are provided. The three auxiliary ribs 59 , 60 , 61 on the other side connecting the outer peripheral portion of the cam bearing portion 21 and the outer peripheral portion of the bearing cylinder 10 are symmetrically formed with respect to the other diameter line L2 - L2 .

However, since the first rib 50 and the second rib 51 are integrally provided on the inner surface of the drum cover 7P of the brake drum cover 7, wherein the first rib 50 and the second rib 51 are supported from the bearing portion. 20 and the cam bearing part 21 extend in the radial direction, and respectively combine the supporting bearing part 20 and the outer peripheral edge of the brake drum cover 7 with the two points P1 and P2 opposite to the supporting bearing part 20 to integrate the cam bearing The two points P3 and P4 at which the outer peripheral edge of the brake drum cover 7 and the cam bearing part 21 are opposed to each other are integrated into one body, so that the first rib part 50 and the second rib part 50 can pass through the The part 51 concentrates on the support bearing part 20 and the cam bearing part 21 which directly receive the braking force, and can improve the rigidity of these bearing parts 20 and 21 intensively. As a result, even if the other parts of the brake drum cover 7 are Even if the part is formed thin, the rigidity required as the brake drum cover 7 can be maintained, and the weight thereof can be reduced.

Furthermore, a third rib 52 and a convex portion 55 are integrally provided on the inner surface of the drum cover 7P of the brake drum cover 7, wherein the third rib 52 connects the one end 50A of the first rib 50 and the One end 51A of the second rib 51 , the convex portion 55 is between the other end 50B of the first rib 50 and the other end 51B of the second rib 51 , and is radially connected to the stopper. The bearing cylindrical portion 10 of the drum cover 7 and the outer peripheral edge of the brake drum cover 7 can further increase the rigidity of the support bearing portion 20 and the cam bearing portion 21 , and further reduce the weight of the brake drum cover 7 .

Moreover, in addition, a fourth rib 53 and a fifth rib 54 are integrally provided on the inner surface of the drum cover 7P of the brake drum cover 7, wherein the fourth rib 53 connects one end of the first rib 50 to the inner surface of the first rib 50. 50A and the other end 51B of the second rib 51 are integrally connected, and the fifth rib 54 passes through the center of the brake drum cover 7 and extends in the radial direction and connects the other end of the first rib 50 50B and one end portion 51A of the second rib portion 51 are integrally connected, thereby further improving the rigidity of the support bearing portion 20 and the cam bearing portion 21 , and further reducing the weight of the drum cover.

As mentioned above, although the Example of this invention was demonstrated, this invention is not limited to this Example, Various Example can be implemented within the range of this invention.

For example, in the above-mentioned embodiment, the case where the drum cover structure of the drum brake is implemented on the front wheel of the motorcycle has been described, but this structure can also be implemented on the rear wheel. Or other wheels with drum brakes.

Claims (2)

1. the brake drum cover of a drum brake is constructed, accommodate drum braking mechanism (6) in the brake drum (5) on being formed at hub for vehicle wheel (4), and cover the opening (5M) of described brake drum (5) by the brake drum cover (7) that does not arrange revolvably, have at described brake drum cover (7): block bearing section (20), it supports supporting axle (23), and described supporting axle (23) is can scalable mode to support a pair of brake shoe (24,24) of drum braking mechanism (6); Camshaft bearing section (21), it supports camshaft (29), and described camshaft (29) is provided with the brake cam (30) that makes described brake shoe (24,24) carry out scalable action, it is characterized in that:

Internal surface at described brake drum cover (7) is provided with the first flank (50) and the second flank (51) integratedly, wherein, the first flank (50) radially extends from described block bearing section (20), and the two point (P1 that the outer periphery of this block bearing section (20) and brake drum cover (7) are relative with described block bearing section (20), P2) connect to one, described the second flank (51) radially extends from described camshaft bearing section (21), and the two point (P3 that the outer periphery of this camshaft bearing section (21) and brake drum cover (7) are relative with described camshaft bearing section (21), P4) connect to one

Internal surface at described brake drum cover (7) is provided with the 3rd flank (52) and protrusion (55) integratedly, wherein, described the 3rd flank (52) links an end (50A) of described the first flank (50) and an end (51A) of described the second flank (51); Described protrusion (55) is between the other end (51B) of the other end of described the first flank (50) (50B) and described the second flank (51), links the bearing cartridge section (10) of described brake drum cover (7) and the outer periphery of brake drum cover (7) along radial direction.

2. the brake drum cover of drum brake as claimed in claim 1 is constructed, it is characterized in that: the internal surface at described brake drum cover (7) is provided with the 4th flank (53) and the 5th flank (54) integratedly, wherein, described the 4th flank (53) passes the center of brake drum cover (7) and extends along diametric(al), and an end (50A) of described the first flank (50) and the other end (51B) of described the second flank (51) are connected to one; Described the 5th flank (54) passes described center and extends along diametric(al), and the other end (50B) of described the first flank (50) and an end (51A) of described the second flank (51) are connected to one.

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