KR20150038952A - method for manufacturing a piston of under drive break - Google Patents

Abstract

The present invention relates to a method to manufacture an underdrive brake piston where the underdrive brake piston is manufactured from a cold-formed plate of a metal material, minimizing an amount of materials to be used and reducing energy consumption; and edge shaping for each stepwise section of the underdrive brake piston such that it can accurately be performed. The method to manufacture an underdrive brake piston comprises: a material preparation step of preparing a plate from the material; a piercing step of penetrating a center hole on the plate; a blanking step of blanking the plate with the center hole, and manufacturing a plate ring product; a cold-forming step of cold-forming the plate ring product, and stepwise forming an area around the center hole and an area around an outer circumference to manufacture a shaped product with an inner circumference stepwise section and an outer circumference stepwise section; and an annealing step to perform a heat treatment of heating, and then cooling the shaped product to remove residual stress.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a piston,

The present invention minimizes the amount of material used and enables energy consumption to be reduced by forming a plate material of a flat plate by cold plate material so that an underdrive brake piston can be manufactured. And more particularly, to a method of manufacturing an underdrive brake piston according to a new form.

In general, an automatic transmission is a device that automatically obtains optimum torque conversion according to the running speed and load of the vehicle.

The brake piston of the underdrive is a part used in the automatic transmission described above. It connects the plate connected to the underdrive brake chamber and the disk connected to the hub to transmit the engine power from the chamber to the hub when the automatic transmission is shifted And cooperates with a coil spring that helps release the piston when the hydraulic pressure is released.

The structure of such an underdrive brake piston 10 is as shown in FIGS. 1 and 2, and in relation to the technology of the underdrive, as disclosed in Korean Patent Laid-Open Nos. 10-2007-0092351 and 10- 2009-0049311 and the like.

On the other hand, the above-mentioned underdrive brake piston 10 is generally formed by molding the center hole 11, the inner peripheral side step portion 12 and the outer peripheral side step portion 13 by a hot forging process after heating the round bar material to a high temperature Roughing, finishing, and deburring are used to produce final products.

However, the hot forging process is disadvantageous in that it requires a large amount of energy consumption due to the heating of the material at a high temperature, and that it is difficult to satisfy the precise dimensions and the amount of material to be input is larger than that of warm forging or cold plate forming. Further, It is difficult to perform roughing before finishing.

Of course, in order to solve the above-described problem, it is also possible to form a plate-like material into a cold plate material forming process instead of a round bar material, and then perform each machining process.

3, when the corner portions 14a and 14b forming the step portions 12 and 13 of the underdrive brake piston 10 are formed in the cold plate material forming process, Of the battery was not charged. That is, as the punches (1, 2) are operated only in the vertical direction, the material flow to the respective corner portions constituting the step portions (12, 13) is not smoothly performed and the non- And the like.

In addition, when an underdrive brake piston is to be formed by a usual cold plate forming process, the upper surface of the material is concentrated and pushed to the center by pushing the center of the plate material so as to protrude downward, The overall machining becomes complicated and the outer diameter of the workpiece is reduced. Therefore, there is a problem in that a material having a diameter larger than the diameter of the finished workpiece must be supplied.

It is an object of the present invention to provide an underdrive brake piston which can be manufactured by forming a plate metal material into a cold plate to minimize the amount of material used, The present invention also relates to a method of manufacturing an underdrive brake piston according to a new form in which energy consumption is reduced and corner forming of each step of the underdrive brake piston is accurately performed.

According to an aspect of the present invention, there is provided a method of manufacturing an underdrive brake piston, the method comprising: preparing a planar blank; A piercing step of forming a center hole through the prepared material; A blanking step of blanking the center hole formed blank to produce a flat ring type product; A cold plate material forming step of forming a cold rolled plate material of the manufactured flat ring type product to form a molded article having inner and outer peripheral stepped portions formed by stepping peripheral and outer peripheral portions of the center hole; And performing an annealing process for heating and cooling the molded product to remove residual stress.

The cold plate material forming step may include a first cold plate material forming step of manufacturing a molded article having each of the steps formed in the flat ring type product, a cold plate material forming step of cold- And a cold cold plate forming step.

Further, during the cold plate forming process of the primary cold plate forming step, the plurality of flat plate-like products are moved gradually from the central portion to the radial position, And is performed using a sheet material forming apparatus to which a split punch is applied.

The secondary cold plate forming step is characterized in that the step of forming the secondary cold plate is performed in a plurality of steps such that the dimensions of the molded product are progressively processed until the dimensions of the product are such that roughing can be omitted.

The determination of the outer diameter of the blanking punch in the blanking step is determined by applying a work clearance in a range of 10% to 20%.

The above-described method of manufacturing an underdrive brake piston of the present invention can be manufactured in an underdrive brake piston through a cold plate molding method using a flat metal material, thereby minimizing the energy consumption, And it is possible to reduce the manufacturing cost and the manufacturing cost.

According to another aspect of the present invention, there is provided a method of manufacturing an underdrive brake piston, which includes a plurality of divided punches capable of radially moving a punch when forming a cold plate, so that the material flows smoothly at corner portions of each step of the underdrive brake piston So that it is possible to prevent the forming defects of the corners from being formed and to precisely perform the forming until the dimension to such an extent that the roughing operation can be omitted by the cold plate forming, Effect.

1 is a plan view for explaining a general underdrive brake piston;
2 is a cross-sectional view for explaining a general underdrive brake piston
Fig. 3 is a schematic view for explaining a molding defective state in a forging operation of a general underdrive brake piston
4 is a flowchart showing a method of manufacturing an underdrive brake piston according to an embodiment of the present invention
5 is a block diagram schematically showing an apparatus for manufacturing an underdrive brake piston according to an embodiment of the present invention.
6 is a state diagram illustrating a state of the underdrive brake piston according to the embodiment of the present invention,
7 is a cross-sectional view showing a cross-sectional structure for explaining a process of manufacturing an underdrive brake piston according to an embodiment of the present invention
FIG. 8 is an exploded perspective view illustrating a first plate material forming apparatus among the facilities for manufacturing an under drive brake piston according to the embodiment of the present invention.
FIG. 9 is a perspective view for explaining the structure of a divided punch of a primary plate material forming apparatus among the facilities for manufacturing an under drive brake piston according to the embodiment of the present invention.
10 is a bottom view for explaining the operation state of the first plate material forming apparatus in the apparatus for manufacturing an under drive brake piston according to the embodiment of the present invention.
FIGS. 11 to 15 are diagrams for explaining the process of forming the primary cold plate by the primary plate material forming apparatus during the manufacturing process of the underdrive brake piston according to the embodiment of the present invention. FIG.

Hereinafter, a preferred embodiment of a method for manufacturing an underdrive brake piston of the present invention will be described with reference to FIGS. 4 to 15 attached hereto.

Prior to the explanation, the underdrive brake piston manufactured by the manufacturing method of the present invention is an underdrive brake piston 10 of the structure shown in Figs. 1 and 2 introduced by the prior art, An inner circumferential step portion 12 formed in a stepped shape around the center hole 11 and formed with a stepped outer circumferential portion, and an outer step portion 13 formed as a stepped portion.

FIG. 4 is a flowchart illustrating a method of manufacturing an underdrive brake piston according to an embodiment of the present invention. FIG. 5 is a block diagram schematically illustrating a structure of an underdrive brake piston manufacturing apparatus according to an embodiment of the present invention. And FIGS. 6 and 7 are state diagrams illustrating a process of manufacturing an underdrive brake piston according to an embodiment of the present invention.

The method of manufacturing an underdrive brake piston according to an embodiment of the present invention includes the steps of preparing a material S110, a piercing step S120, a blanking step S130, a cold plate forming step S210, S220, And an annealing step (S300). The under-drive brake piston 10 can be manufactured by pressing the plate material thereby to reduce the overall manufacturing cost, reduce the energy consumption, and simplify the machining. .

The method of manufacturing the underdrive brake piston according to the embodiment of the present invention will be described in more detail in each step.

First, the material preparation step (S110) is a process of preparing a material for manufacturing the underdrive brake piston (10).

Here, the material for manufacturing the underdrive brake piston 10 is used as a plate-like metal plate.

That is, in the embodiment of the present invention, the material cost can be reduced by using the plate material, and by using the cold plate material instead of using hot forging, energy consumption can be minimized and the processing precision can be improved.

Particularly, the metal plate prepared as described above is provided in a coiled state on a feeder (not shown), through which continuous feeding can be performed.

Next, the piercing step S120 is a step of penetrating the center hole 11 of the underdrive brake piston 10 through a metal plate supplied through the feeder, and the blanking step S130 is a step of forming the center hole 11 11 is a process of manufacturing a prototype ring-shaped prototype 20 in which a center hole 11 is formed by providing a through-formed metal plate and blanking it.

The material preparing step S110, the piercing step S120, and the blanking step S130 described above are successively performed in the single press mold 100.

Particularly, in the embodiment of the present invention, it is determined that the determination of the outer diameter of the blanking punch 112 in the blanking step S130 is determined by applying the work clearance in the range of 10% to 20%.

That is, considering that the clearance unbalance between the upper punch mold 110 and the lower die 120 constituting the press mold 100 may cause burrs on the outer circumferential surface of the flat ring-like prototype article 20, And the occurrence of burrs described above can be prevented by applying the clearance within the range of 10 to 20%. At this time, when the work clearance is less than 10%, it is preferable that the work clearance should be determined to be at least 10% or more as the amount of burr is increased. When the work clearance is 20% or more, It is desirable to determine a work clearance of 20% or less.

On the other hand, reference numeral 111 is a piercing punch.

Next, the cold plate material forming steps S210 and S220 are performed by cold plate-forming the ring-shaped prototype 20 of the flat plate so that the peripheral portion and the outer peripheral portion of the center hole 11 are stepped to form the inner side step portion 12 And the outer step portion 13 are further molded into a molded product 30.

In the embodiment of the present invention, the above-described cold plate forming step is divided into a first cold plate forming step (S210) and a second cold plate forming step (S220).

The primary cold plate forming step S210 is a process for manufacturing the molded product 30 in which the step portions 12 and 13 are formed in the ring-shaped prototype 20, and in particular, the primary cold plate forming step S210 Like prototype product 20 is gradually moved radially from the central portion as the ring-shaped prototype product 20 is pressed, and a plurality (not more than two) of the ring-shaped prototype articles 20 Is performed by using the sheet material forming apparatus 200 to which the split punch 212 of FIG.

That is, the punch of the plate material forming apparatus 200 for forming the primary cold plate is formed by a plurality of divided punches so as to be movable not only in the axial direction but also in the radial direction, So that the flow of the material to the edge portions constituting the step portions 12 and 13 can be smoothly guided.

8 to 11 specifically show the structure of a plate material forming apparatus (hereinafter, referred to as " primary plate material forming apparatus ") 200 for forming the primary cold plate material forming step S210 , The primary plate material forming apparatus 200 will be briefly described as follows.

First, the primary plate forming apparatus 200 is divided into an upper mold part 210 and a lower mold part 220.

The upper mold part 210 includes an outer punch 211 for molding the outer step portion 13 of the under drive brake piston 10 and an inner punch 211 for molding the inner step portion 12 of the under drive brake piston 10 An upper mandrel 213 for guiding the split punch 212 to move in the radial direction and a plurality of split punches 212 for dividing the outer punch 211 and each split punch 212 And a guide vane 214 for transmitting a pressing force to move downward. At this time, the divided punches 212 are divided into a plurality of portions along the periphery of the upper mandrel 213, and are integrally pinched by the elastic support rings 215, And is gradually moved outwardly by the inclination formed by the circumferential surface of the upper mandrel 213. As a result,

The lower mold part 220 includes an upper die 221 on which a molded product 30 is placed and molded and a lower die part 223 for molding the outer step part 13 of the brake piston 10 together with the outer punch 211 A slide die 223 for forming an inner circumferential side stepped portion 12 of the underdrive brake piston 10 together with the respective divided punches 212 and a lower die 222 for restraining the upper mandrel 213 And a lower mandrel 224. At this time, the slide die 223 is configured to be moved downward by a pressing force by the split punch 212.

In the second cold plate forming step S220, the molded product 30 formed by the first cold plate forming step S210 is formed into a separate plate forming apparatus (hereinafter referred to as " secondary plate forming autonomous ") 300 to form cold plates and to process each part of the molded product 30 again. The second plate material forming apparatus 300 is a plate material forming apparatus composed of a single punch to which a plurality of divided punches 212 that are moved in the radial direction are not applied unlike the primary plate material forming apparatus 200, Is a plate material forming apparatus configured to have higher processing precision than the car plate material forming apparatus (200).

This is because the primary sheet material forming apparatus 200 has a structure in which a plurality of divided punches 212 are applied, and therefore, by the radial movement of each divided punch 212 during the execution of the primary cold material forming step S210 It is inevitable that a plurality of unformed portions 31 are formed along the circumferential direction as in the state of the molded product 30 in which the primary molding of FIG. 5 has been completed. In view of this, the secondary plate molding apparatus 300 The second cold plate forming step S220 is further performed so that the molding of the molded product 30 can be performed on the unformed portion 31. [

In particular, the secondary cold plate forming step S220 is performed so that the dimensions of the molded product 30 are gradually processed until the dimensions are such that the roughing process can be omitted.

That is, as shown in FIGS. 5 to 7, the molded product 30 that has undergone the primary molding is continuously and additionally formed twice or more to minimize the amount of machining for machining so that the roughing process can be omitted. So that the overall manufacturing time can be shortened.

At this time, the secondary plate material forming apparatus 300 for the secondary cold plate forming step S220 may be constituted by a progressive type mold so that a plurality of processing operations by a single die apparatus can be continuously performed , As shown in the embodiment, it is possible to provide two or more of the secondary plate material forming apparatuses 300 and to make the secondary plate material forming apparatuses 300 have different processing accuracy, So that gradual precision molding of the mold 30 can be performed.

Next, the annealing step (S300) is a process of removing the residual stress by performing heat treatment in the heat treatment furnace (400) after heating the molded product (30).

That is, the residual stress existing in the corresponding molded product 30 is removed during the cold plate forming step (S210, S220) through the annealing step (S300).

Hereinafter, with reference to FIGS. 6 and 7, and FIGS. 12 to 15, a process of manufacturing a brake piston based on each stepwise underdrive brake piston manufacturing method according to the embodiment of the present invention will be described in more detail. Explain it.

First, a flat metal plate material wound on a feeder and provided in a coil form is provided as a press mold 100. Continuously piercing and blanking are performed by the operation of the press mold 100, The ring-shaped prototype 20 of the formed plate is manufactured.

At this time, considering that the outer diameter of the blanking punch 112 constituting the press die 100 is designed with a working clearance of 10 to 20%, burrs are not generated on the peripheral surface of the prototype product 20.

The ring-shaped prototype 20 manufactured through the above process is provided to the primary plate material forming apparatus 100 and the primary cold material forming step S210 is performed by the primary plate material forming apparatus 100 do.

11 to 15, the upper die part 110 is moved downward and the upper die 121 of the lower die part 120 is mounted on the upper die 121. In this first cold die plate forming step S210, The divided punch 112 is moved in the radial direction by the inclination of the circumferential surface formed by the upper mandrel 113 so that the material is separated from each of the step portions 12 and 13, As shown in FIG.

Therefore, the ring-shaped prototype 20, which has performed the primary cold plate forming step S210 by the above-described primary plate material forming apparatus 100, is a molded product having the inner side step portion 12 and the outer side step portion 13 The workflow can be smoothly guided to the corner portions constituting the step portions 12 and 13 by the operation of the respective divided punches 112, .

The molded product 30 after completion of the primary cold plate forming step S210 is sequentially provided to a plurality of secondary sheet material forming apparatuses so that the secondary cold sheet material forming step S220 by the respective secondary sheet material forming apparatuses is performed Through this process, the molded product 30 is progressively processed to the extent that the roughing process can be omitted.

Subsequently, the molded product 30 in which the secondary cold plate forming step S220 is completed is provided to the heat treatment furnace 400 to perform the annealing step S300 to remove the residual stress, The brake piston 10 is completed through machining (S400).

At this time, since the molded product 30 is formed to have precision enough to omit the roughing process through the cold plate forming step S210 and S220, the roughing process is not performed at the time of the machining, 30 so that the final brake piston 10 can be completed.

Of course, at the time of machining, the deburring operation is performed on the outer peripheral surface of the molded product 30 at the same time. At this time, since the molded product 30 is processed so that no burr exists, the deburring operation can be omitted, .

As a result, the method of manufacturing the underdrive brake piston according to the embodiment of the present invention can be manufactured in the brake piston through the cold plate molding method using the flat metal material, so that the energy consumption can be minimized, Shortening of manufacturing cost and manufacturing cost can be achieved.

Further, in the method of manufacturing an underdrive brake piston according to the embodiment of the present invention, when the cold plate is formed, the punch is constituted by a plurality of divided punches 112 radially movable, so that the stepped portions 12, 13 So that it is possible to prevent the forming defects with respect to the corner portions and to perform precise molding until the dimensions to such an extent that the roughing operation can be omitted by cold plate forming It has the additional advantage that it is possible to shorten the post-processing time.

10. Brake Piston 11. Center Ball
12. Inner step section 13. Outer section step
20. Prototype 30. Molded product
31. Fine mold 100. Press mold
110. Upper punch mold 120. Lower die mold
111. Piercing punch 112. Blanking punch
200. Primary plate material forming device 210. Upper mold part
211. Outer punch 212. Split punch
213. Upper Mandrel 214. Guide to Ann Bills
215. Elastic support ring 220. Lower mold part
221. Upper die 222. Lower die
223. Slide die 224. Lower mandrel
300. Second plate material forming device 400. Heat treatment furnace
500. Machining device

Claims (5)

A material preparing step of preparing a plate-like material;
A piercing step of forming a center hole through the prepared material;
A blanking step of blanking the center hole formed blank to produce a flat ring type product;
A cold plate material forming step of forming a cold rolled plate material of the manufactured flat ring type product to form a molded article having inner and outer peripheral stepped portions formed by stepping peripheral and outer peripheral portions of the center hole; And,
And performing an annealing process for heating and cooling the molded product to remove residual stress. The method of manufacturing an underdrive brake piston according to claim 1, The method according to claim 1,
The cold plate forming step
A primary cold plate forming step of producing a molded article in which each step is molded in a flat ring type product,
And a second cold plate forming step of forming cold plates of the produced molded article and re-machining the respective parts of the molded article. 3. The method of claim 2,
A plurality of divided punches for guiding a flow of material to edges of each of the stepped ring-shaped products while being gradually moved radially from the central portion as the flattened ring-shaped product is pressed during the cold plate forming step of the primary cold plate- Wherein the step (b) is performed using a plate material forming apparatus to which the under-drive brake piston is applied. The method according to claim 2 or 3,
Wherein the step of forming the secondary cold plate is performed in a plurality of steps such that the dimensions of the molded product are progressively processed until the dimensions of the product are such that roughing can be omitted. The method according to claim 1,
Wherein the determination of the outer diameter of the blanking punch in the blanking step is determined by applying a working clearance in the range of 10% to 20%.

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