WO2016112604A1

WO2016112604A1 - Brake drum

Info

Publication number: WO2016112604A1
Application number: PCT/CN2015/078529
Authority: WO
Inventors: 吕继贤; 蒲光明
Original assignee: 山东浩信机械有限公司
Priority date: 2015-01-13
Filing date: 2015-05-08
Publication date: 2016-07-21

Abstract

A brake drum relates to a vehicle drum brake, the brake drum comprising a brake drum body (1); the brake drum body (1) comprises a mounting portion (101) used to connect to a vehicle wheel and a braking portion (103) used to mate with a brake shoe, and the mounting portion (101) and the braking portion (103) are provided with a transition connection portion (102) therebetween; a wall of the braking portion (103) is provided with one, two or more than two crevices (6), and each crevice (6) starts from an end portion of the braking portion (103) and ends at the transition connection portion (102); the entirety of an outer peripheral surface of the braking portion (103)is tightly fitted with a loop device thereon. Upon braking, the thermal expansion stress and swelling stress of the brake drum body (1) are released at the crevices, such that the possibility of a longitudinal small crack developing into multiple cracks and in turn leading to a fracture is reduced, thus creating high safety and long service life. The arrangement of the loop device improves tensile strength and fatigue resistance of the brake drum body (1), and the loop device generates a force to hold the brake drum body (1) tightly, thus preventing the brake drum body (1) from flying out when the brake drum body (1) bursts, and improving service life and use safety.

Description

Brake drum

Solemnly declare:

The present invention claims the priority of the following two patent applications:

The application date is April 29, 2015, the application number is 201520270309.2, and the Chinese utility model patent application named “Brake Drum”;

The application date is January 13, 2015, and the application number is 201510016496.6, and the Chinese invention patent application named "pre-cracking brake drum".

Technical field

The present invention relates to the field of drum brake technology for vehicles, and more particularly to a brake drum.

Background technique

Drum brake (brake) is one of the important components of the vehicle. At present, in the truck, the most widely used is the integrally cast drum brake, which includes the brake drum and brake shoes, brake shoes. It can be in contact with the inner side of the brake drum. The brake drum is in a rotating state during the running of the vehicle. When braking, the brake shoe is pressed against the brake drum by the braking force, and the frictional resistance between the brake drum and the brake drum is used to decelerate or drive the vehicle. Parking to ensure safe driving.

When the car is heavy-duty, high-speed, especially on the long slope or steep slope, the temperature of the inner wall of the brake drum rises sharply due to the need of a large braking force and multiple consecutive braking to ensure that the car is in a controllable state. The temperature difference between the inside and the outside of the brake drum is increased, resulting in a sharp drop in the high temperature mechanical properties of the brake drum material and a decrease in fatigue strength. The traditional brake drum is made of gray cast iron, which has the typical characteristics of low strength and high brittleness. In order to reduce the negative effects of these characteristics, the wall of the brake drum must be made thick to ensure a high structural strength of the brake drum. In this way, when braking, the temperature difference between the inside and the outside of the brake drum body is larger, and the temperature difference stress is large, the high temperature mechanical properties of the material are further deteriorated, and the expansion stress generated by the brake is not eliminated in time, resulting in braking. The drum body develops from longitudinal microcracking to cracking and eventually to cracking. Therefore, the overall cast brake drum has a short service life.

In addition, after the brake drum is braked, if it is in contact with water, the drum body may be thermally cracked or burst due to chilling. In severe cases, the brake drum may rupture and fly out to cause a safety accident, so the safety of use. Poor.

Summary of the invention

The technical problem to be solved by the present invention is to provide a brake drum to eliminate thermal expansion stress or tensile stress, reduce the occurrence of cracking phenomenon, high safety and long service life.

In order to solve the above technical problem, the technical solution of the present invention is: a brake drum comprising: a brake drum body, the brake drum body including a mounting portion for connecting with a wheel and for mating with the brake shoe a braking portion, a transition connecting portion is disposed between the mounting portion and the braking portion; and one or two or more cracks are disposed on a wall of the braking portion, and each of the cracks is An end portion starting from the braking portion terminates in the transition joint portion; a hoop device is tightly fitted over the entire outer peripheral surface of the braking portion.

Wherein, the transition connection portion is provided with a plurality of through holes corresponding to the crack, and each of the cracks terminates in one of the through holes.

Wherein, the crack is a linear crack, a zigzag crack or a wave crack.

Wherein, the hoop device may be: a hollow cuff comprising a solid portion of the cuff connected together, the transparent portion of the cuff being open to the atmosphere.

Wherein, the transparent portion of the cuff includes one or more heat dissipation hole groups, and each of the heat dissipation hole groups includes two or more arcuate long holes arranged in a circumferential direction.

Wherein, one or more annular ribs are disposed on an outer circumferential surface of the solid portion of the ferrule, and the annular rib is disposed adjacent to the heat dissipation hole group.

Wherein, the hoop device may further include: a first ferrule arranged in an axial direction, the brake portion on one end away from the transition joint portion and located between the adjacent two first ferrules a second ferrule; the outer ring of the first ferrule is provided with an annular groove that is consistent with the direction in which the first ferrule extends.

Wherein the width of the first ferrule is greater than the width of the second ferrule; the outer diameter of the first ferrule is smaller than the outer diameter of the second ferrule.

Wherein the outer diameter of the transition connecting portion near one end of the braking portion is larger than the outer diameter of the braking portion, and the first ferrule abuts against the transition connecting portion.

After adopting the above technical solution, the beneficial effects of the present invention are:

Since the wall of the braking portion is provided with one, two or more cracks, each of the cracks The slits start at the end of the braking portion and terminate at the transition joint. Therefore, when the brake drum body is braked, its thermal expansion stress and the tensile stress are released at the crack, thereby reducing the brake. The drum body develops from longitudinal microcracking to cracking and eventually leads to cracking, high safety and long service life. Moreover, since the outer peripheral surface of the braking portion is tightly fitted with the hoop device, not only the radial expansion deformation can be effectively restrained, but also the tensile strength and fatigue resistance of the brake drum body are improved; and the hoop device is applied to the brake drum body. There will be a tight grip, which avoids the danger of the brake drum body rupturing and flying out, greatly improving the service life and safety of use; in addition, the wall thickness of the brake portion corresponding to the hoop device can be effectively reduced, not only can it be effectively reduced The temperature difference between the inside and outside of the small brake drum, and the brake tension or thermal expansion stress is transmitted to the hoop device, which improves the thermal conductivity, improves the force of the brake drum body, and generates a turtle for the heat dissipation and the body wall of the brake drum. The crack laid the foundation.

When the hoop device adopts a hollow cuff structure, the cuff sleeve is hollowed out, which can enhance the heat dissipation effect. Because of the good heat dissipation effect, the temperature difference between the body and the outside of the brake drum is reduced, thereby facilitating the reduction of the longitudinal microcrack to the turtle. Cracking and eventually leading to the probability of cracking, increasing the service life of the brake drum. Since the cuff is a one-piece structure, it is easy to assemble, and the assembly efficiency of the cuff and the brake drum body is improved.

When the hoop device adopts the structure of the first ferrule arranged axially and the second ferrule between the adjacent two ferrules, the width of the first ferrule is provided because the first ferrule is provided with an annular groove It is larger than the width of the second ferrule, thereby increasing the heat dissipation area, thereby greatly improving the heat dissipation effect by the first ferrule; at the same time, the first ferrule and the second ferrule are combined and tightly fitted on the outer circumferential surface of the braking portion. In addition, the structural strength and load carrying capacity of the brake drum body are improved. Since the first ferrule and the second ferrule are of a split structure, they are easy to manufacture and improve the flexibility of assembly.

DRAWINGS

1 is a schematic perspective view of a first embodiment of the present invention;

Figure 2 is a front elevational view of Figure 1;

Figure 3 is a perspective view showing the three-dimensional structure of the cuff of Figure 1;

Figure 4 is a front elevational view of the brake drum body of Figure 1;

Figure 5 is a perspective view showing the structure of a second embodiment of the present invention;

Figure 6 is a front elevational view showing the structure of the third embodiment of the present invention;

Figure 7 is a cross-sectional structural view of Figure 6;

Figure 8 is a cross-sectional structural view showing the fourth embodiment of the present invention;

In the figure, 1-brake drum body; 101-mounting portion; 102-transition connecting portion; 103-brake portion; 2-stretching rib; 3-cuffing sleeve; 31-ring rib; 32-curved long hole; 4-through hole; 5-process groove; 6-crack; 71-first ferrule; 701-annular groove; 72-second ferrule.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Embodiment 1

As shown in FIG. 1, FIG. 2 and FIG. 4, a brake drum includes a cast brake drum body 1. The brake drum body 1 includes a mounting portion 101 coupled to the wheel and mates with the brake shoe. The braking portion 103, the connecting portion 101 and the braking portion 103 are provided with a transition connecting portion 102. The mounting portion 101 is a flange structure, and the transition connecting portion 102 is provided with a plurality of reinforcing ribs 2 in the longitudinal direction.

The wall of the braking portion 103 is evenly distributed with four cracks 6 , each of which starts from the end of the braking portion 103 and terminates at the transition connecting portion 102 . The transition connecting portion 102 is provided with four through holes 4 . The number is equal to the crack 6 and each crack 6 terminates in a through hole 4. In order to form a crack, a process groove 5 is formed in the brake drum body 1 during casting, and the process tank 5 is in communication with the through hole 4, and a linear crack is formed in the process tank 5 by press forming. The function of the crack is to release the thermal expansion stress or the tensile stress generated by the brake drum body during braking, which can reduce the probability that the brake drum body develops from longitudinal microcrack to crack and eventually causes cracking, thereby improving the safety of use. The number of the cracks 6 is at least one, and if two, it is preferentially distributed on the annular wall of the entire braking portion 103. Where there are cracks, the ribs 2 will be placed on both sides to improve the overall strength of the brake drum body.

As shown in FIG. 1 and FIG. 2, the entire outer peripheral surface of the braking portion 103 is tightly fitted with a hoop device. In the first embodiment, the hoop device is a hollow cuff 3, and the cuff 3 is preferably cast iron or may be Cast steel material, in general, the hoop 3 and the brake drum body 1 need to be thermally assembled to ensure that the cuff 3 does not disengage from the brake drum body 1 under any working conditions.

As shown in Figure 3, the solid parts of the cuff 3 are joined together, the transparent portion of the cuff 3 and the atmosphere Pass to improve heat dissipation. The transparent portion of the ferrule 3 includes a plurality of venting holes groups, at least one set, and each of the venting hole groups includes a plurality of (two or more) arcuate elongated holes 32 spaced in the circumferential direction. In order to improve the structural strength and mechanical properties of the cuff 3, a plurality of (one or more) annular beads 31 are provided on the outer peripheral surface of the solid portion of the cuff 3, and the annular bead 31 is disposed adjacent to the heat dissipation hole group. The hollow structure is not limited to this, and all structures that can ensure both strength and heat dissipation are feasible. The greatest advantage of the hollow structure is that the cuff 3 can be integrated to facilitate the assembly efficiency of the cuff 3 and the brake drum body 1.

Embodiment 2

As shown in FIG. 5, the specific structure of the second embodiment is basically the same as that of the first embodiment, and the difference is that the crack 6 is a zigzag-shaped crack formed by wire cutting, and since it is a wire cutting molding, a preset process groove is not required. The crack 6 can also be a wavy crack or as another form of crack that can be implemented by those skilled in the art without affecting the normal operation of the brake drum. Ribs 2 are not required.

Embodiment 3

As shown in FIG. 6 and FIG. 7, the specific structure of the third embodiment is basically the same as that of the first embodiment, except that in the third embodiment, the hoop device includes a plurality of (two or more) first rows arranged in the axial direction. The ferrule 71 is provided on the outer ring of the first ferrule 71 with an annular groove 701 which is consistent with the direction in which the first ferrule extends (ie, the cross-sectional shape of the first ferrule 71 is substantially U-shaped), and the transition is close to The first ferrule 71 of the connecting portion 102 abuts against the transition connecting portion 102; a second ferrule 72 is disposed between the adjacent first ferrules 71 on the braking portion 103 at one end of the transition connecting portion 102. The figure illustrates a situation in which three first ferrules 71 are axially arranged from the abutment of the transition connecting portion 102, and then three pairs of second ferrules 72 and first ferrules 71 are arranged at intervals. All of the second ferrule 72 and the first ferrule 71 abut each other, the drawing is only schematic, and the number of the second ferrule 72 and the first ferrule 71 and the second ferrule 72 and the Whether a ferrule 71 abuts against each other is defined.

The width of the first ferrule 71 is greater than the width of the second ferrule 72, and the outer diameter of the first ferrule 71 is smaller than the outer diameter of the second ferrule 72.

The outer diameter of the transition connecting portion 102 near the end of the braking portion 103 is larger than the outer diameter of the braking portion 103, so that the outermost one of the first ferrules 71 abuts against the transition connecting portion 102.

Since the first ferrule 71 is provided with the annular groove 701, the width of the first ferrule 71 is greater than the width of the second ferrule 72, so that the heat dissipation effect of the brake drum of the structure is greatly improved by the first ferrule 71; The first ferrule 71 is combined with the second ferrule 72 to be tightly fitted on the outer peripheral surface of the braking portion, thereby improving the structural strength and carrying capacity of the brake drum body. The hoop device adopts the first ferrule 71 and the second ferrule 72 of the split structure, which is convenient for processing and manufacturing, and the assembly flexibility is improved.

Embodiment 4

As shown in FIG. 8, the specific structure of the fourth embodiment is basically the same as that of the third embodiment, except that in the fourth embodiment, the crack 6 is a zigzag-shaped crack formed by wire cutting, and since it is a wire cutting molding, no preset process is required. groove. The crack 6 can also be a wavy crack or as another form of crack that can be implemented by those skilled in the art without affecting the normal operation of the brake drum. Ribs 2 are not required.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Industrial applicability

One or two or more cracks are formed on the brake drum wall, each crack starts at the end of the brake portion and terminates at the transition joint portion, and the brake drum body is braked. The thermal expansion stress and the tensile stress are released at the crack, thereby reducing the probability that the brake drum body develops from longitudinal microcrack to crack and eventually causes cracking, which is high in safety and long in service life. Moreover, since the outer peripheral surface of the braking portion is tightly fitted with a hoop device, not only the radial expansion deformation can be effectively restrained, but also the tensile strength and fatigue resistance of the brake drum body are improved; and the hoop device has a brake drum body The holding force avoids the danger of the brake drum body rupturing and flying out, greatly improving the service life and the safety of use; in addition, the wall thickness of the braking portion corresponding to the hoop device can be effectively reduced, which can not only effectively reduce the system The temperature difference between the inside and outside of the drum, and the brake tension or thermal expansion stress are transmitted to the hoop device, which improves the thermal conductivity, improves the force of the brake drum body, and lays the foundation for heat dissipation and prevention of cracks in the inner wall of the brake drum. The foundation.

Claims

A brake drum comprising: a brake drum body, the brake drum body including a mounting portion for connecting with a wheel and a braking portion for mating with the brake shoe, the mounting portion and the system a transitional connection is provided between the moving parts;

One or two or more cracks are provided on the wall of the braking portion, and each of the cracks starts at an end of the braking portion and terminates at the transition joint portion;

The entire outer peripheral surface of the braking portion is tightly fitted with a hoop device.
A brake drum according to claim 1, wherein said transition joint portion is provided with a plurality of through holes corresponding to said slit, each of said slits terminating in said one through hole.
A brake drum according to claim 2, wherein said slit is a linear crack.
A brake drum according to claim 2, wherein said crack is a zigzag crack or a wave crack.
A brake drum according to any one of claims 1 to 4, wherein the hoop device comprises a hollow cuff, the solid portions of the cuff being joined together, and the transparent portion of the cuff Pass with the atmosphere.
A brake drum according to claim 5, wherein said transparent portion of said ferrule includes one or more venting holes, each of said venting holes comprising two or more circumferential directions Curved long holes arranged at intervals.
A brake drum according to claim 6, wherein one or more annular ribs are provided on an outer peripheral surface of said cuff body portion, said annular rib being adjacent to said vent hole group .
A brake drum according to any one of claims 1 to 4, wherein said hoop device comprises an axially aligned first ferrule located on said braking portion at one end remote from said transitional portion A second ferrule is disposed between the two adjacent first ferrules; an annular groove of the first ferrule is disposed on the outer ring of the first ferrule.
The brake drum according to claim 8, wherein a width of said first ferrule is greater than a width of said second ferrule; an outer diameter of said first ferrule is smaller than that of said second ferrule Outer diameter.
The brake drum according to claim 9, wherein an outer diameter of the transition portion near an end of the braking portion is larger than an outer diameter of the braking portion, and the first ferrule is abutted against the On the transition joint.