KR102158596B1 - Manufacturing method of brake piston for disc brake caliper by cold forging and their devices - Google Patents

Abstract

The present invention relates to a method for manufacturing a brake piston for a disc brake caliper by cold forging and an apparatus thereof. The present invention is the method for manufacturing the brake piston for the disc brake caliper by cold forging, comprising: a first step (S1) of forming an inclined and rounded front edge and a flat rear end surface; a second step (S2) of compressing a molded body (A) in the longitudinal direction and stretching the molded body in the transverse direction; a third step (S3) of stretching the molded body in the longitudinal direction while forming a first molded groove (102); a fourth step (S4) of stretching the molded body (A) in the longitudinal direction while forming a second molded groove (103); a fifth step (S5) of stretching the molded body (A) in the longitudinal direction while forming a tapered surface (105); and a sixth step (S6) of forming a plurality of air ventilation grooves (107) on a contact surface (108) to complete.

Description

TECHNICAL FIELD The manufacturing method of brake piston for disc brake caliper by cold forging and their devices is manufactured by cold forging.

The present invention relates to a method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging, and more particularly, to a piston for braking by intimate contact with a brake pad surface by an operation of a disc brake caliper. When forming by cold forging, a disc brake that prevents cracks and loads and enhances the forging effect, thereby making the internal structure compact, making the design dimension precise, improving durability and performance, maximizing braking power and prolonging the service life. It relates to a method and an apparatus for manufacturing a brake piston for caliper by cold forging.

A general disc brake device has a structure that transmits hydraulic pressure generated from a master cylinder to a cylinder in a brake caliper through a brake line, operates a brake pad by moving a piston provided in the cylinder, and obtains a braking force by friction between the brake pad and the disk. have.

Floating caliper has a characteristic that a piston provided only on the inner side moves around the brake disc to operate the brake pad, whereas a fixed caliper operates a number of pairs on both the inner and outer sides around the brake disc. It has a structure in which the provided piston moves to operate the brake pad.

That is, the disc brake is mounted on a certain part of the disc plate of steel cast iron that rotates with the wheel, but the brake pads are pushed to both sides of the disc plate by hydraulic pressure to apply braking by its frictional force. It consists of integrally equipped caliper which constitutes the piston.

In addition, a through hole vertically penetrating to one side of a nut formed to be driven forward and backward is formed inside the hydraulic piston, and a piston bolt is integrally connected to one side of the nut.

In the conventional brake structured as described above, when a press-fitting is applied to the brake, the hydraulic piston in the caliper that has received hydraulic pressure pushes the brake pad and the brake pad is in close contact with both sides of the disk plate to apply pressure to the disk plate.

The brake piston used in such a conventional brake punches out a disk-shaped round blank from a base material of a prescribed thickness, especially a piece of sheet metal, and the blank is formed into a bowl-shaped hollow cylinder using a press die and a stamp. In order to form the bottom of the specified wall thickness and the cylindrical wall of the specified wall thickness, the bowl-type hollow cylinder is manufactured by compression molding.

However, in manufacturing a conventional disk piston, since the wall thickness of the piston is significantly reduced compared to the lower portion of the piston, it is necessary to select a relatively thick base material to obtain a sufficient ratio of the piston wall thickness, that is, stability and stiffness. There is a problem in that manufacturing costs are incurred.

As a technology for manufacturing a conventional disk piston, a method for manufacturing a brake piston, registered Patent Publication No. 10-1088734, has been devised, which punches and presses the inside of the cut molded body with a perma cold forming machine to remove the first hollow part and the first hollow part. In sequential processing of the 2nd hollow part and the 3rd hollow part, as the third hollow part is processed first and the second hollow part is processed afterwards, the inner diameter of the third hollow part is reduced, and the fifth molding located inside the third hollow part The first to fifth processes in which a shrinkage prevention part is formed at the bottom of the mold to maintain a certain inner diameter while the inner diameter of the third hollow part is reduced, and a flow path hole is processed inside the piston by the processing of the second hollow part. It is presented as.

Such a conventional technique is to instantaneously compress a molded body by means of a molding mold (punch) and dies when manufacturing a brake piston, so a load is placed on the molded body and dies, cracks occur in the internal structure, and expensive molding dies and molding molds (punch) This cracking phenomenon occurs.

This technology has a problem in that production costs increase as expensive die molds are frequently replaced, and the manufactured brake piston also degrades the braking force performance, which is a brake function, and the lifespan is shortened.

In addition, when molding a molded body by means of a molding mold (punch) and die for each process, a part of the molded body is pushed to the rear of the molding die and extruded, so the internal structure of the molded body is not dense and its durability is low, and the pushed-out part is precisely forged processing. Because of this, it is not possible to obtain precise design dimensions, and there is a problem that a lot of additional post-processing is required.

One. Korean Registered Patent Publication No. 10-1088734 (announced on November 25, 2011). 2. Korean Registered Patent Publication No. 10-1114990 (announced on February 24, 2012). 3. Korean Patent Application Publication No. 1995-0019290 (published on July 22, 1995).

Accordingly, the present invention was invented to solve the above problem, and an object of the present invention is to prevent cracks and loads when forming a brake piston by cold forging by intimate contact with the brake pad surface by the operation of the disk brake caliper. A method of manufacturing a brake piston for disc brake caliper by cold forging that can enhance the internal structure by increasing the forging effect, make the design dimension precise, and improve the durability and performance to maximize the braking power and extend the life. It is in providing the device.

As an embodiment of a method of manufacturing a brake piston for a disc brake caliper for achieving the object of the present invention by cold forging,

A fixed die having a support die pin and an inner mold made of a cemented carbide material for inserting and mounting the cut cylindrical material (hereinafter referred to as'molding body') after cutting the material to a certain length by a cutting device, and the fixed die. The molded body inserted and mounted in the internal molding die is compressed in the length direction by a predetermined length by a transfer punch pin configured in the transfer punch die and formed to be stretched in the transverse direction. The front edge is formed with an inclined surface and a rounding surface, and the rear section is flat. A first step of forming to be formed;

The molded body molded in the first process is turned 180° to insert and mount it into an inner mold made of cemented carbide material configured in a fixed die, and the preform groove and the preform by a predetermined depth by the transfer punch pin of the transfer punch die. A second step of forming a chamfer at the entrance of the forming groove and simultaneously compressing the formed body in the longitudinal direction and stretching it in the transverse direction;

The molded body molded in the second process is inserted into an inner molding mold made of cemented carbide material formed on a fixed die, and a predetermined depth is provided by a transfer punch pin constructed on a transfer punch die and formed with an air vent hole. A third step of forming the first forming groove and at the same time pressing and sealing the front peripheral end of the formed article by a ramming stroke of the transfer punch die, and forming the formed article to be stretched in the longitudinal direction;

The molded body molded as in the third process is inserted into an inner molding mold made of cemented carbide material configured in a fixed die, and a predetermined transport punch pin configured in the transport punch die and formed with an air vent hole A fourth step of forming the second forming groove by the depth, pressing and sealing the front peripheral end of the formed article by the ramming stroke of the transfer punch die, and forming the formed article to be stretched in the longitudinal direction;

The molded body molded as in the fourth step is inserted into an inner molding mold made of cemented carbide material configured in a fixed die, and a predetermined transport punch pin configured in the transport punch die and formed with an air vent hole A third molding groove is formed to the depth and a tapered molding surface is formed between the second and third molding grooves, and the rear part of the molded body is extruded in the longitudinal direction by an extrusion die configured at the rear of the inner molding mold of the fixed die. A fifth step of compressing and sealing the front peripheral tip of the molded body by the ramming stroke of the transfer punch die while forming the molded body and forming the molded body to be stretched in the longitudinal direction;

By inserting and mounting the molded body molded as in the fifth step into an inner molding mold of cemented carbide material configured on a fixed die, and by a transfer punch pin configured on a transfer punch die and having a plurality of air vent holes formed therein. The second and third forming grooves and a plurality of blocks comprising forming protrusions forming a plurality of flow path grooves on the inner surface of the tapered forming surface, and forming an air vent groove behind the transfer punch pin and the inner forming mold of the fixed die The volume amount of the flow path groove and the volume reduced by the rear extrusion in the fifth process are formed to be transferred to the contact surface and expanded in the longitudinal direction by means of a supporting fixed die pin composed of an air discharge hole of the molded body. In addition, a brake piston for a disc brake caliper comprising a sixth step of compressing and sealing the front peripheral end of the molded body by the ramming stroke of the transfer punch die and forming a plurality of air vent grooves on the contact surface is used in cold forging. It is a method of manufacturing by.

As an embodiment of an apparatus for manufacturing a brake piston for a disc brake caliper for achieving the object of the present invention by cold forging,

It is composed of a cold forming machine, and the cold forming machine is composed of first to sixth forming dies, the first forming die is composed of an inner forming mold made of cemented carbide and a fixed die having a supporting die pin, and a direction corresponding to the fixed die Consists of a transfer punch die consisting of a transfer punch pin that pressurizes the molded body with,

The second molding die constitutes an inner mold made of a cemented carbide material and a fixed die having a supporting fixed die pin, and a transfer punch die configured with a transfer punch pin for pressing the molded body in a direction corresponding to the fixed die,

The third molding die has an inner molding mold made of a cemented carbide material, a fixed die having a fixed support die pin at the rear thereof, and a transfer punch formed by pressing a molded body in a direction corresponding to the fixed die and having an air vent hole. Consists of a transfer punch die consisting of a pin and ramming stroke,

The fourth molding die has an inner molding mold made of a cemented carbide material, a fixed die having a fixed support die pin at the rear thereof, and a transfer punch formed by pressing a molded body in a direction corresponding to the fixed die and forming an air vent hole. Compose a transfer punch die consisting of a pin and ramming stroke,

The fifth molding die has an inner molding mold made of a cemented carbide material, a fixed die having a fixed support die pin at the rear thereof, and a transfer punch formed by pressing the molded body in a direction corresponding to the fixed die and having an air vent hole. A transfer punch die consisting of a pin and a ramming stroke is configured, but an extrusion die is configured to the rear of the inner mold of the fixed die,

The sixth molding die is a fixed die inserted into an inner molding mold made of a cemented carbide material, and a molded body is press-molded in a direction corresponding to the fixed die, and a transfer punch pin and ramming stroke consisting of a plurality of air vent holes ( ramming stroke), and a flow path groove forming protrusion for forming a flow path groove at the tip of the transfer punch pin, and a forming protrusion forming an air vent groove behind the inner molding mold of the fixed die. It is an apparatus for manufacturing a brake piston for a disc brake caliper comprising a structured block and a support fixed die pin configured with a plurality of air discharge holes.

In the present invention, first, during cold forming manufacturing, a piston (molded body) is extruded forward through an extrusion die by a transfer punch pin of a transfer punch die, an internal molding mold of a fixed die, and a support die spin. It prevents the load on the supporting die spin and conveying punch pin so that no cracking occurs.

Therefore, it is possible to extend the life of the caliper manufactured as a molded body, as well as the internal molding mold, the support die spin and the transfer punch pin, and improve durability and performance.

Second, by increasing the manufacturing process of cold forming and dispersing the forming process, it is possible to smoothly form the molded body without being unreasonable and without load when forming the molded body.

Third, during the molding process, the molded body with rounded corners in the initial process is turned 180° and the molding process proceeds to the last process, thereby facilitating installation and extraction from the internal molding mold of the fixed die and the center for each process. It can be precisely and precisely matched, so it can perform precise molding processing.

Fourth, by forming an air vent hole in the transfer punch pin and the fixed die, the compressed air is quickly discharged when molding the molded body to prevent cracks and cracks in the inner mold of the fixed die, and expensive molds are frequently replaced. As it does not, it reduces production cost and also prevents cracking in the molded body, thereby giving reliability to product performance.

Fifth, when the molded body is pressurized by the conveying punch pin, it is pressed and sealed by the ramming stroke to increase the forging effect of the molded object, thereby making the structure compact, designing dimension precise, and minimizing post-processing. have.

1 is a cross-sectional view of a molded body for each process manufactured by the "method of manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
Fig. 2 is an overall view of a "method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
Fig. 3 is a first process diagram of a "method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
Figure 4 is a second process diagram of the "method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
5 is a third process diagram of the "method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" according to an embodiment of the present invention.
6 is a fourth process diagram of "Method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
7A is a fifth process diagram of "Method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
7B is an enlarged view of the "molding part" of FIG. 7A according to the present invention.
Fig. 8 is a sixth process diagram of "Method and apparatus for manufacturing a brake piston for a disc brake caliper by cold forging" of an embodiment according to the present invention.
9A and 9B are enlarged views of a part of the transfer punch pin of FIG. 8 according to the present invention, and FIG. 9A is a front view, and FIG. 9B is a right side view of FIG. 9A.
10 is an enlarged view of the "molding part" of FIG. 8 according to the present invention.
11 is a side view of a “block” and a “supporting fixing die pin” in FIG. 8 according to the present invention.

Hereinafter, it will be described in detail according to the accompanying drawings, shown as preferred embodiments as follows.

The terms defined in the description of the present invention are defined in consideration of functions or forms in the present invention, and should not be understood as limiting technical elements of the present invention.

The present invention will be described in detail in the text of the bar, implementation (態樣, aspect) (or embodiment) that can apply various changes and can have various forms. However, this is not intended to limit the present invention to a specific form of disclosure, and it should be understood that all changes, equivalents, and substitutes included in the spirit and scope of the present invention are included.

In addition, the components in each drawing are expressed by exaggeratingly large (or thick) or small (or thin) or simplified the size or thickness in consideration of the convenience of understanding, but this limits the scope of protection of the present invention. It shouldn't be.

The terms used in the present specification are only used to describe specific embodiments (sun, 態樣, aspect) (or examples), and are not intended to limit the present invention.

Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. .

First, the "method of manufacturing a brake piston for a disc brake caliper by cold forging" of the present invention will be described with reference to FIGS. 1 to 11.

Cylindrical material (hereinafter referred to as'molded body') cut after cutting the material to a certain length by a cutting device (not shown) as shown in FIGS. 1 and 3 shown as the first step (S1) (A) A fixed die (3) having an inner molding mold (1) made of a cemented carbide material and a support die pin (2) for inserting and mounting it, and a molded body (A) inserted and mounted in the inner molding mold (1) of the fixed die (3). ) Is compressed in the longitudinal direction by a predetermined length by pressing of the transfer punch pin 5 configured in the transfer punch die 4 and formed to be stretched in the transverse direction, and the front edge is formed with an inclined surface and a rounding surface, and the rear section is formed with a flat surface. It is molded.

The molded body (A) molded as the first step (S1) as described above is shown in (a) of FIG. 1.

As a second process (S2), the molded body A molded in the first process S1 is shown in FIGS. 1 and 4, and the molded body A molded in the first process S1 is 180°. It is inserted and mounted in the inner molding mold 1a of cemented carbide material composed of the fixed die 3a having the support die pin 2a by turning, and pressurized by the transfer punch pin 5a of the transfer punch die 4a. A preformed groove 100 and a chamfer portion 101 are formed at the entrance of the preformed groove 100 by a predetermined depth, and at the same time, the molded body A is compressed in the longitudinal direction and stretched in the transverse direction to form.

The molded body (A) molded as the second step (S2) as described above is shown in (b) of FIG. 1.

As a third process (S3), the molded body A molded in the second process S2 is supported by the molded body A molded in the second process S2 as shown in FIGS. It is inserted into the inner molding mold (1b) of cemented carbide material composed of the fixed die (3b) having (2b), and the conveying is composed of the conveying punch die (4b) and the air vent hole (6) is formed. The first forming groove 102 is formed to a predetermined depth by pressing the punch pin 5b, and at the same time, the front periphery of the formed body A by the ramming stroke 7 of the conveying punch die 4b. The tip is sealed by pressure and the molded body is formed to stretch in the longitudinal direction.

That is, as the air discharge hole 6 is configured on the conveying punch pin 5b, compressed air is generated when instantaneous pressure is applied to generate high heat, and exploded due to air splitting and the molded body is broken. ) To prevent deformation of the molded body (A) by discharging the compressed air.

Therefore, it prevents the occurrence of wrinkles in the molded body (A) to be molded, and it is formed cleanly and prevents cracking or crushing.

In addition, the structure of the molded body (A) becomes dense and hard, the center (concentricity) does not change, becomes precise, and the molding is completed, and the static water can be output according to the design dimensions.

In addition, it prevents cracking of the internal molding mold 1b of expensive cemented carbide material and prevents the transfer punch pin 5b from cracking, thereby preventing the problem of frequent replacement.

In addition, by pressing and sealing the front peripheral end of the molded body A by the ramming stroke 7 of the transfer punch die 4b, the structure becomes dense and hard, and the molding of the molded body can be formed cleanly.

As described above, the molded body (A) formed as the third step (S3) is shown in (c) of FIG. 1.

As a fourth process (S4), the molded body (A) formed in the third process (S3) is supported by the molded body (A) formed in the third process (S3) as shown in FIGS. A transfer punch pin (5c) that is inserted into an inner molding mold (1c) made of a cemented carbide material configured in a fixed die (3c) having (2c), and is configured in a transfer punch die (4c) and formed with an air discharge hole (6a). The second forming groove 103 is formed to a predetermined depth by pressing of pressure, and at the same time, the front circumferential end of the forming body A is press-sealed by the ramming stroke 7a of the conveying punch die 4c. ) Is formed to stretch in the longitudinal direction.

In other words, as the air discharge hole 6a is formed on the conveying punch pin 5c, compressed air is generated when instantaneous pressure is applied to generate high heat, and air is discharged from the explosion due to air splitting and breaking the molded body (A). The compressed air is discharged through the hole 6a to prevent deformation of the molded body A.

Therefore, it prevents the occurrence of wrinkles in the molded body (A) to be molded, and it is formed cleanly and prevents cracking or crushing.

In addition, the structure of the molded body (A) becomes dense and hard, and the center (concentricity) is not changed and becomes precise, and when the molding is completed, the static water can come out according to the design dimensions.

In addition, it prevents cracking of the internal molding mold 1c of expensive cemented carbide material, and also prevents the transfer punch pin 5c from cracking, thereby preventing the problem of frequent replacement.

And by pressing and sealing the front periphery end of the molded body A by the ramming stroke 7a of the transfer punch die 4c, the structure becomes dense and hard, and the molding of the molded body A can be formed cleanly. .

The molded body (A) molded as the fourth step (S4) as described above is shown in (d) of FIG. 1.

As a fifth step (S5), the molded body A formed in the fourth step (S4) as shown in FIGS. 1 and 7A and 7B showing the molded body A formed in the fourth step S4. A transfer punch pin that is inserted into an inner mold (1d) made of a cemented carbide material configured on a fixed die (3d) having a support die pin (2d), and is configured on a transfer punch die (4d) and has an air discharge hole (6b). The third forming groove 104 is formed by a predetermined depth by pressing (5d), and the tapered forming surface 105 is formed between the second and third forming grooves 103 and 104 and fixed. The rear portion of the molded body A is extruded in the longitudinal direction by an extrusion die 8 configured behind the inner mold 1d of the die 3d, and at the same time, the ramming stroke 7b of the conveying punch die 4d. The front peripheral tip of the molded body A is sealed by pressure, and the molded body A is formed to extend in the longitudinal direction.

That is, as the air discharge hole 6b is formed on the conveying punch pin 5d, compressed air is generated when instantaneous pressure is applied to generate high heat, and the air discharge hole 6b ) To prevent deformation of the molded body (A) by discharging the compressed air.

Therefore, it prevents the occurrence of wrinkles in the molded body (A) to be molded, and it is formed cleanly and prevents cracking or crushing.

In addition, the structure of the molded body (A) becomes dense and hard, and the center (concentricity) is not changed and becomes precise, and when the molding is completed, the static water appears according to the design dimensions.

In addition, it prevents the cracking of the internal molding mold 1d of expensive cemented carbide material and also prevents the transfer punch pin 5d from cracking, thereby preventing the problem of frequent replacement.

And by pressing and sealing the front peripheral end of the molded body A by the ramming stroke 7b of the transfer punch die 4d, the structure becomes dense and hard, and the molding of the molded body A can be formed cleanly. .

In addition, the rear portion of the molded body (A) is extruded in the longitudinal direction by an extrusion die (8) composed of the inner molding mold (1d) of the fixed die (3d), and the diameter of the rear portion of the molded body (A) is predetermined. It is molded to be reduced to the size of.

The molded body (A) molded as above is extruded to the rear by a transfer punch pin (5d), an internal molding mold (1d), and an extrusion die (8), thereby forming the molded body (A), an internal molding mold (1d), and an extrusion die ( 8) It prevents the load and crack does not occur.

Therefore, it is possible to extend the life of the molded body (A), as well as the transfer punch pin (5d) and the inner mold (1d), it is possible to improve the durability and performance.

The extrusion die 8 is supported by a support 8-1, and the molded body A to be molded is supported by a fixed die support pin 2d from the rear.

The molded article (A) molded as a fifth step (S5) as described above is shown in (e) of FIG. 1.

As a sixth step (S6), the molded body A formed in the fifth step (S5) as shown in Figs. 1 and 8 to 11 shown in the fifth step (S5). Inserted and mounted in the inner molding mold 1e of cemented carbide material configured in the fixed die 3e, and pressurized the conveying punch pin 5e formed in the conveying punch die 4e and formed with a plurality of air discharge holes 6c. By forming a plurality of flow path grooves 106 on the inner side of the second and third forming grooves 103 and 104 and the tapered forming surface 105, the transfer punch pin 5e and the fixing die 3e A block 10 and a plurality of air discharge holes 11-1 consisting of a molding protrusion 9 and an air discharge hole 10-1 for forming the air ventilation groove 107 behind the inner molding mold 1e of the The volume amount of the flow path groove 106 and the amount of the rear extrusion volume in the fifth process are formed to be transferred to the contact surface 108 toward the rear and outer sides of the molded body A by the configured support fixed die pin 11 and the length It is molded so as to extend in the direction and also press-sealed the front peripheral end of the molded body (A) by the ramming stroke (7c) of the conveying punch die (4e), and forming a plurality of air vent grooves (107) on the contact surface (108). And a sixth step (S6) to be completed.

That is, as a plurality of air discharge holes 6c are formed on the conveying punch pin 5e, compressed air is generated when instantaneous pressure is applied to generate high heat, and the air discharge hole explodes due to air split and the molded body is broken. The compressed air is discharged through (6c) to prevent deformation of the molded body (A).

The air discharge hole 6c configured in the transfer punch pin 5e is constituted by a single air discharge hole 6c in the longitudinal direction and then radially branched into a plurality of pieces at the tip of the transfer punch pin 5e, thereby finalizing the molded body. When finishing molding, compressed air is quickly and evenly discharged to make the molding state clean and prevent distortion.

Therefore, it prevents the occurrence of wrinkles in the molded body A to be molded, and it is formed cleanly and prevents cracking or crushing, as well as preventing cracking of the transfer punch pin 5e.

In addition, the structure of the molded body (A) becomes dense and hard, and the center (concentricity) is not changed and becomes precise, and when the molding is completed, the static water appears according to the design dimensions.

In addition, it prevents the cracking of the internal mold 1e of expensive cemented carbide material, and also prevents the transfer punch pin 5e from cracking, thereby preventing the problem of frequent replacement.

And by pressing and sealing the front peripheral tip of the molded body A by the ramming stroke 7c of the transfer punch die 4e, the structure becomes dense and hard, and the molding of the molded body A can be formed cleanly. .

Second and third forming grooves 103, 104 and taper forming of the molded body A during compression molding by protruding a plurality of flow path groove forming protrusions 5-1 at the periphery of the tip of the conveying punch pin 5e. A plurality of flow path grooves 106 are formed on the inner surface of the surface 105.

A block 10 consisting of a molding protrusion 9 and a plurality of air discharge holes 10-1 and a plurality of air discharge holes 11-1 are configured behind the inner mold 1e of the fixed die 3e. By configuring the supporting and fixing die pin 11, the flow path groove 106 is formed by the block 10 and the supporting and fixing die pin 11 to the rear and outside of the molded body A when molding by pressing the transfer punch pin 5e. ), the volume amount of the flow path groove 106 according to the molding and the volume amount of which the rear outer diameter of the molded body A is reduced due to the rear extrusion in the fifth step are formed to be transferred to the contact surface 108.

In addition, a plurality of air vent grooves 107 are formed on the contact surface 108 by a plurality of forming projections 9.

The molded body (A) molded as a sixth step (S6) as described above is shown in (f) of FIG. 1.

That is, the molded body (A) formed by the above method forms first to third molding grooves 102, 103, 104 inward, and tapers between the second and third molding grooves 103 and 104. A forming surface 105 is formed, and a plurality of flow path grooves 106 are formed as an inner wall between the second forming groove 103 and the tapered forming surface 105, and a contact surface 108 is formed on the lower outer surface of the formed body A. And a plurality of air vent grooves 107 are formed to constitute a brake piston for a disc brake caliper.

Such a brake piston for a disc brake caliper has excellent durability and performance, a compact internal structure, a clean molded state, a center (concentricity) unchanged and precise, and has a fixed number according to the design dimensions.

The method of manufacturing the brake piston for a disc brake caliper of the present invention as described above by cold forging is performed through an extrusion die by means of an inner forming mold and a supporting die spin of a conveying punch die and a fixed die during cold forming manufacturing. By extruding the piston (molded body) forward, it prevents the load on the molded body as well as the internal molding mold, the supporting die spin and the conveying punch pin, so that no cracks occur, and therefore, the brake piston manufactured as a molded body as well as the transfer punch and internal molding It can extend the life of the mold and improve durability and performance.

In addition, by dispersing the forming process by increasing the manufacturing process of cold forming, the molded body is not unreasonable and does not take a load and can be smoothly molded, and the molded body formed by rounding the corners in the initial step of the molding process is 180 By turning to ° and proceeding the molding process to the last process, it is possible to smoothly install and extract from the internal mold of the fixed die, and precisely and precisely align the center for each process, enabling precise molding processing.

In addition, by forming an air vent hole in the conveying punch pin and the supporting fixed die pin, the compressed air is quickly discharged when molding the molded body to prevent cracks and cracks in the internal molding mold of the fixed die. Since molds are not frequently replaced, production costs can be reduced, and cracks in the molded body can be prevented, thereby providing reliability in product performance.

In addition, when the molded body is press-molded by the transfer punch pin, it is pressed and sealed by a ramming stroke to increase the forging effect of the molded body to make the structure compact, design dimensions precise, and minimize post-processing. have.

Next, an apparatus for manufacturing a brake piston for a disc brake caliper for achieving the object of the present invention by cold forging will be described as follows.

It is composed of a cold forming machine (Q), and the cold forming machine (Q) is composed of first to sixth forming dies 50, 51, 52, 53, 54, 55, and the first forming dies ( 50) consists of a fixed die (3) having an inner mold (11) made of cemented carbide and a support die pin (2), and a transfer punch pin (5) is configured in front corresponding to the fixed die (3) Constructs a punch die (4).

The second molding die 51 is a transfer punch die 4a having an inner molding mold 1a made of a cemented carbide material and a fixed die 3a having a support fixed die pin 2a and a transfer punch pin 5a. Is composed.

The third molding die 52 has an inner molding mold 1b made of a cemented carbide material, a fixed die 3b having a fixed support die pin 2b at the rear thereof, and an air vent hole 6 It is composed of a transfer punch pin 5b and a transfer punch die 4b comprising a ramming stroke 7.

The fourth molding die 53 has an inner molding mold 1c made of a cemented carbide material, a fixed die 3c having a fixed support die pin 2c at the rear thereof, and an air vent hole 6a. A feed punch die 4c having the configured feed punch pin 5c and ramming stroke 7a is configured.

The fifth molding die 54 has an inner molding mold 1d made of a cemented carbide material, a fixed die 3d having a fixed support die pin 2d at the rear thereof, and an air vent hole 6b. The conveying punch die 4d having the configured conveying punch pin 5d and the ramming stroke 7b is constituted, but an extrusion die 8 is formed in the inner mold 1d of the fixed die 3d.

The sixth molding die 55 is a transfer punch pin 5e and a ramming stroke comprising a fixed die 3e and an air vent hole 6c having an inner molding die 1e of cemented carbide material inserted therein. A transfer punch die 4e having (1e) is formed, and a flow path groove forming protrusion 5-1 for forming a flow path groove is formed at the tip of the transfer punch pin 5e, and the fixed die 3e Support consisting of a block 10 consisting of a molding protrusion 9 and a plurality of air discharge holes 10-1 and a plurality of air discharge holes 11-1 to form an air vent groove to the rear of the inner molding mold 1e It is a device made by configuring a fixed die pin (11).

The present invention configured as described above is provided in the first to sixth molding dies 50, 51, 52, 53, 54, 55, each of the inner molding molds (1) (1a) (1b) ( 1c)(1d)(1e) by inserting and mounting the molded body (A) to perform sequential molding for each of the first to sixth molding dies (50) (51) (52) (53) (54) (55) do.

That is, first, the molded body (A) inserted into the inner mold (1) from the first molding die (50) is compressed in the longitudinal direction by a predetermined length by the transport punch pin (3) of the transport punch die (4). It is formed to be stretched in the transverse direction, and the front edge is formed to have an inclined surface and rounding, and the rear section is formed to have a plane.

In the second molding die 51, the molded body A molded from the first molding die 50 is turned 180° and inserted into the inner molding mold 1a made of cemented carbide material formed in the fixed die 3 Mounting and forming a preformed groove 100 and a chamfer 101 at the entrance of the preformed groove 100 by a predetermined depth by a transfer punch pin 5a of the transfer punch die 4a, and at the same time The molded body (A) is compressed in the longitudinal direction and stretched in the transverse direction to form.

In the third molding die 52, the molded body A molded from the second molding die 51 is inserted into an inner molding mold 1b made of a cemented carbide material configured in a fixed die 3b, and a transfer punch die ( Ramming of the transfer punch die (4b) while forming the first molding groove 100 to a predetermined depth by the transfer punch pin (5b) configured in 4b) and formed with an air vent hole (6) The front peripheral tip of the molded body A is compressed and sealed by a ramming stroke 7 and the molded body is formed to be stretched in the longitudinal direction.

In the fourth molding die 53, the molded body A molded from the third molding die 52 is inserted into an inner molding mold 1c made of a cemented carbide material configured in the fixed die 3c, and a transfer punch die ( The second forming groove 102 is formed by a predetermined depth by the conveying punch pin 5c configured in 4c) and having the air discharge hole 6a formed, and at the same time, the ramming stroke 7a of the conveying punch die 4c As a result, the front peripheral end of the molded body A is press-sealed, and the molded body A is formed to extend in the longitudinal direction.

In the fifth molding die 54, the molded body A molded from the fourth molding die 53 is inserted into an inner molding mold 1d made of a cemented carbide material configured in the fixed die 3d, and a transfer punch die ( The third forming groove 104 is formed by a predetermined depth by the transfer punch pin 5d configured in 4d) and the air discharge hole 6b is formed, and the second and third forming grooves 103 and 104 While forming the tapered molding surface 105 between the two, the rear part of the molded body (A) is extruded in the longitudinal direction and transferred at the same time by the extrusion dies (8) configured in the inner molding mold (1d) of the fixed die (3d). By the ramming stroke 7b of the punch die 4d, the front periphery end of the molded body A is press-sealed, and the molded body A is formed to extend in the longitudinal direction.

That is, as the air discharge hole 6b is formed on the conveying punch pin 5d, compressed air is generated when instantaneous pressure is applied to generate high heat, and the air discharge hole 6b ), the compressed air is discharged to prevent the deformation of the molded body (A), preventing the occurrence of wrinkles in the molded body (A) and being formed cleanly, preventing cracking or crushing.

In addition, the structure of the molded body (A) becomes dense and rigid, the center (concentricity) does not change, and becomes precise, and when the molding is completed, the fixed number can come out according to the design dimensions, and the internal mold (1d) of expensive cemented carbide material is prevented from cracking. The transfer punch pin 5d is also prevented from cracking to prevent problems that need to be replaced frequently, and by pressing and sealing the front peripheral end of the molded body A by the ramming stroke 7b of the transfer punch die 4d. The structure becomes dense and hard, and the molding of the molded body (A) can be formed cleanly.

In addition, the rear portion of the molded body (A) is extruded in the longitudinal direction by an extrusion die (8) configured in the inner molding mold (1d) of the fixed die (3d), and the outer diameter of the rear portion of the molded body (A) is a predetermined size. It is molded to be reduced to

In the sixth molding die 55, the molded body A molded from the fifth molding die 54 is inserted into an inner molding mold 1e made of a cemented carbide material configured in the fixed die 3e, and a transfer punch die ( A plurality of flow paths on the inner side of the second and third forming grooves 103 and 104 and the tapered forming surface 105 by the transfer punch pin 5e configured in 4e) and formed with a plurality of air discharge holes 6c A molding protrusion 9 and a plurality of air discharged to form the groove 106 and form the air vent groove 107 behind the inner mold 1e of the transfer punch pin 5e and the fixed die 3e. The volume of the flow path groove 106 toward the rear and outer sides of the molded body A by a block 10 consisting of a ball 10-1 and a fixed die pin 11 comprising a plurality of air discharge holes 10-1 The volume and the volume amount of the reduced rear outer diameter of the molded body (A) due to the rear extrusion in the fifth process are molded to be transferred to the contact surface 108 and stretched in the longitudinal direction, and the transfer punch pin 5e It is completed by pressing and sealing the front peripheral end of the molded body A by the ramming stroke 7c and forming a plurality of air vent grooves 107 on the contact surface 108.

That is, as a plurality of air discharge holes 6c are formed on the conveying punch pin 5e, compressed air is generated when instantaneous pressure is applied to generate high heat, and the air discharge hole explodes due to air split and the molded body is broken. By discharging the compressed air through (6c), the deformation of the molded body (A) is prevented, and the air discharge hole 6c configured in the transfer punch pin 5e has a single air discharge hole 6c in the longitudinal direction. After being constructed, it is constructed by diverging radially from the tip of the transfer punch pin 5e in a number of ways, so that the compressed air is quickly and evenly discharged when final molding of the molded body, thereby making the molded state clean and preventing distortion.

Therefore, it prevents the occurrence of wrinkles in the molded body (A) to be molded, and it is formed cleanly and prevents cracking or crushing, as well as preventing the breakage of the conveying punch pin (5e).In addition, the molded body (A) has a dense and hard structure and (Concentricity) does not change and becomes precise, and when molding is completed, the fixed number can come out according to the design dimensions.

In addition, it prevents cracking of the internal molding mold of expensive cemented carbide material and prevents the transfer punch pin 5e from cracking to prevent the problem of frequent replacement, and the ramming stroke of the transfer punch die 4e ( By pressing and sealing the front periphery end of the molded body (A) by 7c), the structure becomes dense and hard, and the molding of the molded body (A) can be formed cleanly, and there are a number of flow path grooves in the front edge of the transfer punch pin (5e). By protruding the molding protrusion 5-1, a plurality of flow path grooves 106 are provided on the inner side of the second and third molding grooves 103 and 104 and the tapered molding surface 105 of the molded body A during compression molding. It is molded.

In addition, by configuring a supporting fixed die pin 11 having a block 10 having a molding protrusion 9 and a plurality of air discharge holes 6-1 behind the inner molding 1e of the fixed die 3e, When molding by compression of the transfer punch pin 5e, the flow path groove 106 is formed by forming the flow path groove 106 to the rear and outside of the molded body A by the block 10 and the support fixed die pin 11 The volume amount and the volume amount in which the rear outer diameter of the molded body A is reduced due to the rear extrusion from the fifth molding die 54 are formed to be transferred to the contact surface 108.

In addition, a plurality of air ventilation grooves 107 are formed on the contact surface 108 by a plurality of molding protrusions 9.

The molded body (A) formed by the apparatus of the present invention as described above forms first to third molding grooves 102, 103, 104 inward, and between the second and third molding grooves 103 and 104 A tapered forming surface 105 is formed, and a plurality of flow path grooves 106 are formed as an inner wall between the second forming groove 103 and the taper forming surface 105, and a contact surface 108 is formed on the lower outer surface of the formed body A. ) And a plurality of air vent grooves 107 are formed to constitute a brake piston for a disc brake caliper.

Such a brake piston for disc brake caliper has excellent durability and performance, a compact internal structure, a clean molded state, a center (concentricity) unchanged and precise, and has a fixed number according to the design dimensions.

A: Molded body Q: Cold forming machine
1,1a,1b,1c,1d,1e: internal mold 2,2a,2b,2c,2d,2e: support die pin
3,3a,3b,3c,3d,3e: fixed die 4,4a,4b,4c,4d,4e: transfer punch die
5,5a,5b,5c,5d,5e: feed punch pin 5-1: flow groove forming protrusion
6,6a,6b,6c,10-1,11-1: Air exhaust hole 7,7a,7b,7c: Ramming stroke
8: extrusion die 9: molding protrusion
10: block 11: support fixing die pin
50,51,52,53,54,55: first to sixth molding dies
100: preformed groove 102,103,104: first to third forming groove
105: tapered molding surface 106: flow groove
107: air ventilation groove 108: contact surface
S1: 1st process S2: 2nd process
S3: 3rd process S4: 4th process
S5: 5th process S6: 6th process

Claims (7)

A cemented carbide inner mold (1) and a support die pin to insert and install the cut cylindrical material (hereinafter referred to as'molding body') (A) after cutting the material to a certain length by a cutting device (not shown) The fixed die (3) having (2) and the molded body (A) inserted and mounted in the inner molding mold (1) of the fixed die (3) are transferred to the transfer punch pin (5) configured in the transfer punch die (4). A first step (S1) of compressing in the longitudinal direction by a predetermined length by pressing and forming to be stretched in the transverse direction, forming an inclined surface and a rounded surface at the front edge, and forming a flat surface at the rear end surface;
The molded body (A) molded in the first step (S1) is turned 180° and inserted into the inner molding mold (1a) of a cemented carbide material composed of a fixed die (3a) having a support die pin (2a). Then, by pressing by the transfer punch pin 5a of the transfer punch die 4a, the preformed groove 100 and the chamfer 101 are formed at the entrance of the preformed groove 100 by a predetermined depth. A second step (S2) of compressing the molded body (A) in the longitudinal direction and stretching it in the transverse direction at the same time;
Inserting and mounting the molded body (A) molded in the second step (S2) into an inner mold (1b) made of a cemented carbide material configured on a fixed die (3b) having a support die pin (2b), and a transfer punch die (4b) ) And forming the first forming groove 102 to a predetermined depth by pressing the conveying punch pin 5b on which the air vent hole 6 is formed, and at the same time, the conveying punch die 4b A third step (S3) of compressing and sealing the front peripheral end of the molded body A by a ramming stroke 7 and forming the molded body to be stretched in the longitudinal direction;
Inserting and mounting the molded body (A) formed in the third step (S3) into an inner mold (1c) made of a cemented carbide material composed of a fixed die (3c) having a support die pin (2c), and a transfer punch die (4c) ) And forming the second forming groove 103 by a predetermined depth by pressing the conveying punch pin 5c having the air discharge hole 6a formed therein, and at the same time, the ramming stroke 7a of the conveying punch die 4c A fourth step (S4) of compressing and sealing the front peripheral end of the molded body (A) by means of a fourth step (S4) of forming the molded body (A) to be stretched in the longitudinal direction;
Inserting and mounting the molded body (A) formed in the fourth step (S4) into an inner mold (1d) made of a cemented carbide material configured on a fixed die (3d) having a support die pin (2d), and a transfer punch die (4d) ) And forming the third forming groove 104 to a predetermined depth by pressing the transfer punch pin 5d having the air discharge hole 6b formed therein, and also forming the second and third forming grooves 103 and 104 ), the rear portion of the molded body A is extruded in the longitudinal direction by means of an extrusion die 8 configured behind the inner mold 1d of the fixed die 3d while forming the tapered molding surface 105 between them. A fifth step (S5) of compressing and sealing the front peripheral end of the molded body (A) by the ramming stroke (7b) of the conveying punch die (4d) and forming the molded body (A) to extend in the longitudinal direction;
Inserting and mounting the molded body (A) formed in the fifth step (S5) into the inner molding mold (1e) of cemented carbide material configured in the fixed die (3e), and configured in the transfer punch die (4e) and discharges a plurality of air A plurality of flow path grooves 106 are formed on the inner surfaces of the second and third forming grooves 103 and 104 and the tapered forming surface 105 by pressing the conveying punch pin 5e on which the hole 6c is formed. In addition, a molding protrusion 9 and a plurality of air discharge holes 10-1 for forming the air ventilation groove 107 behind the transfer punch pin 5e and the inner molding die 1e of the fixed die 3e The volume amount of the flow path groove 106 to the rear outside of the molded body A by the support fixed die pin 11 consisting of the configured block 10 and a plurality of air discharge holes 11-1 and the rear in the fifth process The extrusion volume is molded to be transferred to the contact surface 108 and stretched in the longitudinal direction, and the front peripheral end of the molded body A is press-sealed by the ramming stroke 7c of the transfer punch die 4e. A method of manufacturing a brake piston for a disc brake caliper by cold forging comprising a sixth step (S6) of forming and completing a plurality of air vent grooves 107 on the contact surface 108. The method of claim 1, wherein in the fifth step (S5), the rear portion of the molded body (A) is extruded in the longitudinal direction with an extrusion die (8), and the diameter of the outer diameter of the rear portion of the molded body (A) is reduced to a predetermined size. A method of manufacturing a brake piston for a disc brake caliper to be molded to be formed by cold forging. According to claim 1, In the sixth step (S6), the air discharge hole (6c) configured in the transfer punch pin (5e) is formed with a single air discharge hole (6c) in the longitudinal direction, and the front end of the transfer punch pin (5e) A method of manufacturing a brake piston for a disc brake caliper comprising a plurality of radially branched and protruding protrusions 5-1 at the tip periphery of the transfer punch pin 5e by cold forging . The method of claim 1, wherein in the sixth step (S6), a block (10) comprising a molding protrusion (9) and a plurality of air discharge holes (10-1) behind the inner molding mold (1e) of the fixed die (3e) By constituting a supporting fixed die pin 11 comprising a plurality of air discharge holes 11-1, when molding by pressing the conveying punch pin 5e, a molded body ( A disk comprising molding so that the volume amount of the flow channel 106 toward the rear outside of A) and the volume amount of which the rear outer diameter of the molded body A is reduced due to the rear extrusion in the fifth step are transferred to the contact surface 108 A method of manufacturing a brake piston for a brake caliper by cold forging. delete delete delete

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