KR101786289B1 - A brake drum assembly and a method for manufacturing the same - Google Patents

A brake drum assembly and a method for manufacturing the same Download PDF

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Publication number
KR101786289B1
KR101786289B1 KR1020160001900A KR20160001900A KR101786289B1 KR 101786289 B1 KR101786289 B1 KR 101786289B1 KR 1020160001900 A KR1020160001900 A KR 1020160001900A KR 20160001900 A KR20160001900 A KR 20160001900A KR 101786289 B1 KR101786289 B1 KR 101786289B1
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KR
South Korea
Prior art keywords
brake drum
outer ring
main body
drum assembly
notch
Prior art date
Application number
KR1020160001900A
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Korean (ko)
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KR20170082749A (en
Inventor
유상헌
Original Assignee
현대자동차주식회사
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Priority to KR1020160001900A priority Critical patent/KR101786289B1/en
Publication of KR20170082749A publication Critical patent/KR20170082749A/en
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Publication of KR101786289B1 publication Critical patent/KR101786289B1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D51/00—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like
    • F16D51/16—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D65/12—Discs; Drums for disc brakes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D2065/13—Parts or details of discs or drums
    • F16D2065/1304—Structure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D2065/13—Parts or details of discs or drums
    • F16D2065/134—Connection

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Braking Arrangements (AREA)

Abstract

The present invention relates to a brake drum assembly and a method of manufacturing the same. The method of manufacturing a brake drum assembly according to the present invention includes the steps of: (S100) forming a brake drum 100 composed of a main body 110, a web 120 and a notch portion 130; (S200) machining the outer ring insertion portion (111) along the outer peripheral surface of the main body (110) so as to form a step on the outer peripheral surface of the main body (110); Heating and expanding the cylindrical outer ring 200 (S300); (S400) of pressing the outer ring (200) into the outer ring insertion portion (111) to form the brake drum assembly (10); Cooling the brake drum assembly 10 (S500); And a step (S600) of machining the inner circumferential surface of the main body 110 to form a friction surface 112 in contact with the brake shoe. According to the present invention, compressive residual stress is added to the notch portion to cancel the tensile stress due to friction, thereby reducing the tensile stress finally acting on the notch portion by about 18%. Thus, the life of the brake drum can be extended to about five times or more.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a brake drum assembly,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake drum assembly and a manufacturing method thereof, and more particularly, to a brake drum assembly and a method of manufacturing the same that can reduce a tensile stress finally acting on a notched portion.

Generally, a brake system is classified into a main brake used mainly for driving and a parking brake used for parking the automobile. In addition, the main brake includes a hydraulic brake for braking through the hydraulic pressure generated by the operation of the brake pedal, an output brake for using a large braking force such as a large-sized automobile, and a braking force Air brakes to generate the air brakes. In addition, the hydraulic brake includes a drum brake which is integrally formed with the wheel so as to generate a braking force by pressing a brake shoe attached with a lining on a rotating brake drum from the inside.

Here, the drum type brake includes a brake drum having a through hole formed at a central portion of the web and having a plurality of bolt holes formed around the through hole, a back plate fixed to the axle, and a brake shoe A lining which is attached to an outer surface of the brake shoe so as to be in direct contact with the brake drum to stop the rotation of the brake drum and turn the kinetic energy into heat energy; A wheel cylinder to be pressed onto the brake drum, and the like. Further, when manufacturing the above-described brake drum, conventionally, i) casting a drum shape using a cast iron or the like, and ii) processing the inner side (i.e., friction surface) of the brake drum. (See Fig. 1)

Accordingly, when the driver presses the brake pedal, the hydraulic pressure generated in the master cylinder is transmitted to the wheel cylinder, and the brake shoe is instantaneously moved to the brake drum rotated together with the wheel by the piston movement of the wheel cylinder. The lining attached to the outer surface of the brake shoe is pressed against the inner surface (i.e., the friction surface) of the brake drum to generate frictional force, and the braking is performed by stopping the rotation of the brake drum by this frictional force.

At this time, the lining is directly pressed on the brake drum rotated during operation of the brake to generate a strong frictional force, so that the temperature of the brake drum rises sharply (see Fig. 2 (a)). As a result, the body of the brake drum is thermally expanded and deformed, and tensile stress is concentrated on the notch, which is a connecting portion between the main body and the web (see Fig. 2 (b)). If such a tensile stress is repeated, fatigue is accumulated in the notched portion (refer to FIG. 2 (c)). If this cumulative fatigue is excessive, fatigue fracture occurs in the notch portion and breakage of the brake drum, (See Fig. 2 (d)).

Patent Registration No. 10-0457214 (November 4, 2004)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a brake drum assembly capable of canceling a tensile stress due to friction by adding a residual compressive stress to a notch portion, And a method for producing the same.

The method of manufacturing a brake drum assembly according to the present invention includes the steps of: (S100) forming a brake drum 100 composed of a main body 110, a web 120 and a notch portion 130; (S200) machining the outer ring insertion portion (111) along the outer peripheral surface of the main body (110) so as to form a step on the outer peripheral surface of the main body (110); Heating and expanding the cylindrical outer ring 200 (S300); (S400) of pressing the outer ring (200) into the outer ring insertion portion (111) to form the brake drum assembly (10); Cooling the brake drum assembly 10 (S500); And a step (S600) of machining the inner circumferential surface of the main body 110 to form a friction surface 112 in contact with the brake shoe.

The brake drum 100 includes a cylindrical body 110; A disc-shaped web 120 extending from the main body 110 to close one end of the main body 110; And a notch 130 connecting the main body 110 and the web 120.

In the expanding step S300, the diameter of the inner circumferential surface of the outer ring 200, which is smaller than the diameter of the outer circumferential surface of the outer ring insertion portion 111, is larger than the diameter of the outer circumferential surface of the outer ring insertion portion 111, And the outer ring 200 is inflated.

In the cooling step S500, the outer ring 200 is cooled and shrunk to generate a compressive residual stress in the notch 130, which is a connecting portion between the main body 110 and the web 120, And the drum assembly 10 is cooled.

The forming step S600 is characterized in that the inner peripheral surface of the cylindrical body 110 is processed in a vertical direction to form the friction surface 112. [

A brake drum assembly according to the present invention, comprising: a brake drum (100) composed of a main body (110), a web (120) and a notch portion (130); And an outer ring (200) which is press-fitted into the brake drum (100) to prevent deformation of the notch (130).

The brake drum 100 includes a cylindrical body 110; A disc-shaped web 120 extending from the main body 110 to close one end of the main body 110; And a notch 130 connecting the main body 110 and the web 120.

The main body 110 is formed along the outer circumferential surface of the main body 110 to form a step on the outer circumferential surface of the main body 110. When the outer ring 200 is pressed into the brake drum, And an outer ring insertion portion (111) contacting the inner circumferential surface.

The material of the outer ring 200 is carbon steel.

The outer ring 200 is heated and expanded before it is press-fitted into the brake drum 100, is press-fitted into the brake drum 100, and then cooled and shrunk.

The outer ring 200 is cooled and shrunk to generate compressive residual stress in the notch 130.

As described above, according to the present invention, a compressive residual stress is applied to the notched portion to cancel the tensile stress due to friction, thereby reducing the tensile stress ultimately acting on the notched portion by about 18%.

Thus, the life of the brake drum can be extended to about five times or more.

FIG. 1 and FIG. 2 illustrate the problems of the prior art.
3 is a flowchart of a method of manufacturing a brake drum assembly according to the present invention;
4 and 5 illustrate a method of manufacturing a brake drum assembly according to the present invention.
6 is a perspective view of a brake drum assembly according to the present invention.
7 is a cross-sectional view of a brake drum assembly according to the present invention.
8 to 10 are diagrams illustrating effects of a brake drum assembly according to the present invention.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term to describe its invention in the best way And should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents It should be understood that water and variations may be present. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a flowchart of a method of manufacturing a brake drum assembly according to the present invention, and FIGS. 4 and 5 are views illustrating a method of manufacturing a brake drum assembly according to the present invention. 3 to 5, a method of manufacturing a brake drum assembly according to the present invention includes a forming step S100, a processing step S200, an expanding step S300, a forming step S400, (S500), and forming (S600).

In the molding step S100, the brake drum 100 composed of the main body 110, the web 120 and the notch portion 130 is formed. The brake drum 100 includes a cylindrical body 110, a disc 120 in the form of a disc extending from the body 110 to close one end of the body 110, 120, which are connected to each other. The brake drum 100 is generally formed of a cast iron material. The cast iron is very susceptible to tensile stress, and stress concentration is particularly large in the notched portion 130 having a narrow width.

In the processing step S200, the outer ring insertion portion 111 is formed along the outer peripheral surface of the main body 110 so as to form a step on the outer peripheral surface of the main body 110. The outer ring 200 is inserted into the outer ring insertion portion 111 and the outer ring 200 serves to eliminate the stress concentration of the notch portion 130. The role of the outer ring 200 will be described later in detail.

In the expanding step S300, the cylindrical outer ring 200 is heated and expanded. Also, in the forming step S400, the expanded outer ring 200 is press-fitted into the outer ring insertion portion 111 to form the brake drum assembly 10. In the expanding step S300, the diameter of the inner circumferential surface of the outer ring 200, which is smaller than the diameter of the outer circumferential surface of the outer ring insertion portion 111, is equal to or larger than the diameter of the outer circumferential surface of the outer ring insertion portion 111 So that the outer ring 200 is inflated.

That is, after the outer ring 200 is inflated, the diameter of the inner peripheral surface of the outer ring 200 becomes equal to or larger than the diameter of the outer peripheral surface of the outer ring insertion portion 111. Accordingly, the outer ring 200 can be easily inserted into the outer ring insertion portion 111.

In the cooling step S500, the brake drum assembly 10 is cooled. In the cooling step S500, the outer ring 200 is cooled and shrunk to generate a compressive residual stress in the notch 130, which is a connecting portion between the main body 110 and the web 120, And cooling the drum assembly 10. That is, the diameter of the outer peripheral surface of the outer ring insertion portion 111 is larger than the diameter of the inner peripheral surface of the outer ring 200 before the outer ring 200 is inflated. Therefore, when the outer ring 200 is cooled and shrunk in the cooling step S500, the diameter of the inner peripheral surface of the outer ring 200 is deformed to be smaller than the diameter of the outer peripheral surface of the outer ring insertion portion 111. Accordingly, the outer ring 200 applies an external force to the main body 110 to deform the main body 110, thereby generating a compressive residual stress in the notch 130. In FIG. 8, it is possible to confirm the shape deformation of the brake drum (in particular, the body portion) and the residual stress resulting therefrom in the cooling step 500 as described above.

In the forming step S600, the inner circumferential surface of the main body 110 is machined to form a friction surface 112 in contact with the brake shoe. That is, as the main body 110 is deformed in the cooling step S500, the inner peripheral surface (i.e., the friction surface) of the main body 110, which is in contact with the brake shoe not shown, is also deformed. Accordingly, the inner peripheral surface of the main body 110 is processed to form the friction surface 112 so as to maximize the friction force between the brake shoe and the inner peripheral surface of the main body 110 and prevent uneven wear of the brake shoes. At this time, in the forming step S600, the inner circumferential surface of the cylindrical body 110 may be processed to form the friction surface 112 in a vertical direction.

Thereafter, when the manufactured brake drum assembly is used, even if a tensile stress is generated due to friction between the brake shoes and the brake drum body, the compressive residual stress generated by the outer ring 200 is canceled. Accordingly, the tensile stress finally acting on the notched portion can be reduced by about 18%, and the service life of the brake drum assembly can be extended to about five times or more. Hereinafter, a brake drum assembly manufactured by the above manufacturing method will be described in detail.

FIG. 6 is a perspective view of a brake drum assembly according to the present invention, and FIG. 7 is a sectional view of a brake drum assembly according to the present invention. 6 and 7, a brake drum assembly according to the present invention is a brake drum assembly manufactured by the method of manufacturing the brake drum assembly, and includes a brake drum 100 and an outer ring 200.

The brake drum 100 is composed of a main body 110, a web 120 and a notch portion 130. A circular web 120 extending from the main body 110 to close one end of the main body 110 and a plurality of main bodies 110 and the web 120, As shown in FIG.

In addition, the main body 110 includes an outer ring insertion portion 111 and a friction surface 112. The outer ring insertion portion 111 is formed along the outer peripheral surface of the main body 110 to form a step on the outer peripheral surface of the main body 110. When the outer ring 200 is pushed into the brake drum, the outer circumferential surface of the outer ring insertion portion 111 comes into contact with the inner circumferential surface of the outer ring 200.

The outer ring 200 is press-fitted into the brake drum 100 to prevent the notch 130 from being deformed. More specifically, the outer ring 200 is heated and expanded before it is press-fitted into the brake drum 100, and is press-fitted into the brake drum 100 and then cooled and shrunk. The outer ring 200 is cooled and shrunk to apply an external force to the main body 110 to deform the main body 110 and generate compressive residual stress in the notch 130. The material of the outer ring 200 may be a carbon steel but is not limited thereto and may include a material capable of generating compressive residual stress in the notch 130 by expansion and contraction due to heat do.

8 to 10 are views for explaining the effect of the brake drum assembly according to the present invention. 8 is a view showing the shape deformation of the brake drum (in particular, the main body) in the cooling step 500 and the residual stress therebetween. FIGS. 9 and 10 show the results of the "acceleration- Quot; deceleration-constant speed maintenance "process.

In the tests of Figures 9 and 10, i) imparting a heat flux according to the braking to the brake drum, ii) imparting a convective heat transfer coefficient at a rate for external heat dissipation, and iii) The thermal stress of the brake drum was examined through the heat flux corresponding to the three stages of "deceleration - constant speed maintenance". 10 (a)). In the case where the outer ring is simply press-fit by machining the outer ring insertion portion (Fig. 10 (b)), There is almost no difference in the thermal expansion of the brake drum according to the present invention, and therefore, the effect of reducing the stress is hardly obtained.

However, in the case of the present invention, it was confirmed that the residual stress acts in the compression direction due to cooling of the outer ring 200, thereby reducing the strength of the final stress (FIG. 10 (c)). Therefore, the present invention reduces the stress of about 18% compared to the prior art, and confirms the effect of securing the life of the brake drum 5 times or more.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, as claimed, and will be fully understood by those of ordinary skill in the art. The present invention is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and variations are possible within the scope of the present invention, and it is obvious that those parts easily changeable by those skilled in the art are included in the scope of the present invention .

10 Brake drum assembly
100 brake drum
110 body
111 outer ring insertion portion
112 friction surface
120 Web
130 notch portion
200 outer ring

Claims (11)

(S100) of forming a brake drum (100) composed of a main body (110), a web (120) and a notch portion (130);
(S200) machining the outer ring insertion portion (111) along the outer peripheral surface of the main body (110) so as to form a step on the outer peripheral surface of the main body (110);
Heating and expanding the cylindrical outer ring 200 (S300);
(S400) of pressing the outer ring (200) into the outer ring insertion portion (111) to form the brake drum assembly (10);
Cooling the brake drum assembly 10 (S500); And
(S600) of machining the inner circumferential surface of the main body 110 to form a friction surface 112 in contact with the brake shoe,
The outer ring insertion portion 111 is formed from a stepped portion of the main body 110 that is a part of the main body 110 to an outer peripheral surface of the notch portion 130,
In the cooling step S500, the outer ring 200 is cooled and shrunk to deform the upper portion of the main body 110 to be bent to a predetermined angle inside the brake drum assembly 10, And the brake drum assembly (10) is cooled so as to generate a compressive residual stress in the notch (130), which is a connecting portion of the web (120). The method according to claim 1,
The brake drum 100 includes a cylindrical body 110;
A disc-shaped web 120 extending from the main body 110 to close one end of the main body 110; And
A notch 130 connecting the body 110 and the web 120;
≪ RTI ID = 0.0 > 1, < / RTI > The method according to claim 1,
In the expanding step S300, the diameter of the inner circumferential surface of the outer ring 200, which is smaller than the diameter of the outer circumferential surface of the outer ring insertion portion 111, is larger than the diameter of the outer circumferential surface of the outer ring insertion portion 111, And expanding the outer ring (200). delete The method according to claim 1,
(S600) of forming the friction surface (112) by machining the inner circumferential surface of the cylindrical body (110) in the vertical direction. A brake drum assembly manufactured by the method for manufacturing a brake drum assembly according to any one of claims 1 to 3,
A brake drum 100 composed of a main body 110, a web 120 and a notch 130; And
An outer ring 200 press-fitted into the brake drum 100 to prevent deformation of the notch 130;
≪ / RTI > The method according to claim 6,
The brake drum 100 includes a cylindrical body 110;
A disc-shaped web 120 extending from the main body 110 to close one end of the main body 110; And
A notch 130 connecting the body 110 and the web 120;
≪ / RTI > 8. The method of claim 7,
The main body 110 is formed along the outer circumferential surface of the main body 110 to form a step on the outer circumferential surface of the main body 110. When the outer ring 200 is pressed into the brake drum, An outer ring inserting portion 111 contacting the inner circumferential surface;
Wherein the brake drum assembly comprises: The method according to claim 6,
Wherein the material of the outer ring (200) is carbon steel. The method according to claim 6,
Wherein the outer ring (200) is heated and expanded before being pressed into the brake drum (100), press-fitted into the brake drum (100), and then cooled and shrunk. 11. The method of claim 10,
Wherein the outer ring (200) is cooled and shrunk to generate compressive residual stress in the notch (130).
KR1020160001900A 2016-01-07 2016-01-07 A brake drum assembly and a method for manufacturing the same KR101786289B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020160001900A KR101786289B1 (en) 2016-01-07 2016-01-07 A brake drum assembly and a method for manufacturing the same

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Application Number Priority Date Filing Date Title
KR1020160001900A KR101786289B1 (en) 2016-01-07 2016-01-07 A brake drum assembly and a method for manufacturing the same

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KR20170082749A KR20170082749A (en) 2017-07-17
KR101786289B1 true KR101786289B1 (en) 2017-10-17

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