KR101533218B1 - Method of Burr Free Precision Processing for Secondary Piston with Press Metallic Mold - Google Patents

Abstract

The present invention relates to a method of precisely machining a secondary piston by a press die and more specifically to a method of machining a plurality of secondary pistons in a single mold and simultaneously preventing the generation of fine burrs in the inner and outer diameters The present invention relates to a method for precise machining of a secondary piston by a die. The precision machining method of the secondary piston includes the steps of preparing a press die 10 having punch dies 11a and 11b and hole punches 12a and 12b; Preparing a press working apparatus having a collect chuck (21) to which a workpiece (M) of a secondary piston is fixed; Advancing the collect chuck 21 to be in close contact with the punch dies 11a and 11b and machining the holes with the hole punches 12a and 12b; And removing the burrs generated in the outer diameter of the workpiece (M) of the secondary piston with a brush, wherein the collet chuck (21) is punched by a repetition of clamping and un- The collet chuck 21 is brought into tight contact with the dies 11a and 11b and the collet chuck 21 is rotated forward or backward by the rotary motor 22 so that the holes are machined by the divided punches 12a and 12b at the divided angles.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of precisely machining a secondary piston of a secondary piston by a press die,

The present invention relates to a method of precisely machining a secondary piston by a press die and more specifically to a method of machining a plurality of secondary pistons in a single mold and simultaneously preventing the generation of fine burrs in the inner and outer diameters The present invention relates to a method for precise machining of a secondary piston by a die.

In automotive engineering, a master cylinder refers to a control device that converts the mechanical force exerted from the outside (the force exerted on the brake pedal) into hydraulic pressure. By the operation of the master cylinder, the hydraulic pressure is generated by the two pistons moving along the bore formed therein, and the control device controls the movement of the slave cylinder connected to the master cylinder. The master cylinder can be applied to a brake system and a clutch system, and Fig. 4 shows an example of a tandem master cylinder having a known structure.

4, in the master cylinder 40, the primary piston 42 and the secondary piston 43 are spaced apart from each other so as to be mutually movable in a cylindrical cylinder body 41 having a bore formed therein . A stem 44 in which a compression spring 441 is disposed is provided in a compression space formed between the primary piston 42 and the secondary piston 43 so that the primary piston 42 can be moved. On the other hand, the secondary piston 43 may be installed at one end of the cylinder body 41 and movably along the stem 44 on which the compression spring 431 is disposed. A push rod (not shown) is coupled to the push hole 421 formed in the primary piston 42 so that the back-and-forth movement of the primary piston 42 can be induced.

The oil stored in the oil tank 46 can be introduced into the interior of the cylinder body 41 through the inlet ports 461 and 462 formed in the cylinder body 42. The oil that has flowed into the oil chamber generates oil pressure by the relative movement of the primary piston 41 and the secondary piston 42, thereby enabling the vehicle to be controlled, for example, by operating the disc brake.

Prior art relating to the manufacture of a master cylinder is disclosed in Patent Publication No. 2000-0037247 'Apparatus and Manufacturing Method for Master Cylinder for Automobile'. The prior art includes a material cutting step of cutting an aluminum material for forming a master cylinder into a predetermined size using a cutting device; Heating the cut material to 570 to 585 캜 using an induction heater such that the cut material has spheroidizing structure as a whole and the liquid phase and the solid phase are uniformly mixed; Preheating the mold for injecting the heated material and injecting the heated material with the preheated mold; A material pressing step in which the heating material injected into the mold is pressurized at a rate of 0.45 to 1.5 m / s when the material is mixed in a liquid phase and a solid phase when the material is filled in the cavity of the mold, A molding step of applying a multi-stage speed control system for preventing liquid segregation during pressurization; Coagulating the product molded by the press for about 5 to 10 seconds, and taking out the coagulated product using an ejector; And a quenching step of rapidly cooling the product taken out by the ejector into the cooling water, thereby producing a master cylinder for an automobile.

Another prior art related to the manufacture of master cylinders and pistons is US Pat. No. 6,494,040 entitled " METHOD FOR MAKING A MASTER CYLINDER AND MASTER CYLINDER OBTAINED BY SAID METHOD ". The prior art discloses a method of manufacturing a master cylinder of a tandem type having a reliable and quick reaction capability.

Another prior art related to the manufacture of master cylinders is US Patent No. 7,866,155 to MASTER CYLINDER AND METHOD OF MANUFACTURING THE SAME. The prior art discloses a method of manufacturing a master cylinder capable of relieving stress concentration so that damage to the cup seal can be prevented.

A first piston hole set and a second piston hole set are provided in the primary piston and the secondary piston provided in the master cylinder, respectively, and each of the hole sets can be formed along the circumferential direction of the periphery of the piston. Also, the number of hole sets may be sixteen, and they may be arranged at equal intervals along the circumferential direction around the piston. Each hole in such a set of holes can be machined, for example, in a machining center. However, when a hole is machined in a machining center, a deviation between the holes may be generated, and on the other hand, uniformity of the product is difficult to be guaranteed.

The prior art does not disclose a method of processing a hole set formed in a primary or secondary piston.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art and has the following objectives.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of precisely machining a burr of a secondary piston by means of a press die for removing burrs and burrs which may be generated during the perforation process of the press.

According to a preferred embodiment of the present invention, a precision machining method of a secondary piston comprises the steps of: preparing a press die having a punch die and a hole punch; Preparing a press working apparatus having a collect chuck to which a work piece of the secondary piston is fixed; Advancing a collect chuck to adhere to the punch die and machining the hole with a hole punch; And removing a burr generated in the outer diameter of the work piece of the secondary piston with a brush, wherein the collet chuck is brought into close contact with the punch die by repetition of clamping and un-clamping, The chuck is rotated forward or backward by a rotary motor, and the holes are machined by the hole punches at the divided angles.

According to another preferred embodiment of the present invention, the punch dies are paired so that the machining of the holes takes place simultaneously in the pair of punch dies.

According to another preferred embodiment of the present invention, the hole punch has a punch reference hole for hole machining.

The manufacturing method according to the present invention can solve the problems caused by excessive processing time generated in the piston manufacturing process of the master cylinder, lowering of productivity due to generation of burr in the machining area, and increase in investment cost for processing equipment . Specifically, the method for machining a secondary piston by press working according to the present invention has an advantage in that productivity and quality can be improved by allowing holes of at least two secondary pistons to be simultaneously machined.

Figs. 1A and 1B are a front view and a side view, respectively, of an embodiment of a press mold applied to the method according to the present invention.
Figure 2a shows a front view of an embodiment of a press working apparatus applied to the method according to the invention.
FIG. 2B illustrates an embodiment of a process in which a workpiece is closely attached to a punch die in a press die according to the present invention.
FIG. 2C shows an embodiment of a position where a workpiece is fixed by a collet chuck and a hole is machined.
3 shows an embodiment of the shape of the hole of the secondary piston manufactured by the method according to the present invention.
4 shows an embodiment of a known master cylinder.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have the same or similar functions, so that they will not be described repeatedly unless necessary for an understanding of the invention, and the known components will be briefly described or omitted But should not be understood as being excluded from the embodiments of the present invention.

A method of precisely machining a secondary piston applied to an automobile master cylinder according to the present invention comprises the steps of: preparing a press mold (10) having punch dies (11a, 11b) and hole punches (12a, 12b); Preparing a press working apparatus having a collect chuck (21) to which a workpiece (M) of a secondary piston is fixed; Advancing the collect chuck 21 to be in close contact with the punch dies 11a and 11b and machining the holes with the hole punches 12a and 12b; And removing the burrs generated in the outer diameter of the workpiece (M) of the secondary piston with a brush, wherein the collet chuck (21) is punched by a repetition of clamping and un- The collet chuck 21 is brought into tight contact with the dies 11a and 11b and the collet chuck 21 is rotated forward or backward by the rotary motor 22 so that the holes are machined by the divided punches 12a and 12b at the divided angles.

This is explained in detail below.

Figs. 1A and 1B are a front view and a side view, respectively, of an embodiment of a press mold applied to the method according to the present invention.

The manufacturing method according to the present invention can be performed based on press working and specifically by punching working or piercing working using a press die. The press mold can be pressed into the press mold 10 and the work M can be processed in the press mold 10 by using the press working apparatus 20. [ .

The press mold 10 includes punch dies 11a and 11b to which workpieces of the secondary piston can be fixed and hole punches 12a and 12b for machining holes in the workpieces fixed to the punch dies 11a and 11b . The punch dies 11a and 11b can be at least one and a pair of punch dies 11a and 11b can be installed in one press mold 10 as shown in Fig. The punch dies 11a and 11b can have appropriate shapes to fix the workpiece of the secondary piston to be fixed and can be installed so that the workpiece can be fixed in the horizontal direction.

The hole punches 12a and 12b are for punching or piercing and can be installed so as to be movable up and down and can be installed at positions where holes can be machined on the workpieces fixed to the punch dies 11a and 11b . The hole punches 12a and 12b can be installed so as to be movable up and down or in the left and right direction, but can be installed to move up and down at a predetermined position. The restriction of movement of the hole punches 12a and 12b in the lateral direction is advantageous in that a hole can be formed at a uniform position along the circumferential surface of the workpiece and at the same time can contribute to the improvement of the production incense.

The punch dies 11a and 11b may be fixed to the support members 13a and 13b respectively and the support members 13a and 13b may be installed to the die holder 14. [ The die holder 14 is fixed to the base F so that the press die 10 can be stably fixed. The apparatus for fixing the punch dies 11a and 11b and the apparatus for moving the hole punches 12a and 12b can be stably fixed or moved by the frame member 15 fixed to the base F. [

A punch guide 18 is provided above the punch dies 11a and 11b so that the hole punches 12a and 12b can be moved to a predetermined position in the vertical direction. And the punch guide 18 can be moved up and down along an induction guide 16 such as a linear guide and the upper side of the induction guide 16 can be fixed to the fixed holder 17. [ As described above, the pair of hole punches 12a and 12b are simultaneously moved up and down in accordance with the movement of one punch guide 18, so that holes are simultaneously machined on the workpieces fixed to the pair of punch dies 11a and 11b .

The press mold 10 may include various fastening devices for fastening the workpieces to the punch dies 11a and 11b and may include various drive devices for driving the hole punches 12a and 12b or the punch guides 18 can do. The present invention is not limited by such various fixing devices or driving devices.

An apparatus for fixing workpieces to the punch dies 11a and 11b will be described below.

2A shows a front view of an embodiment of a press working apparatus 20 applied to a method according to the present invention and FIG. 2B shows a front view of a press work apparatus 20 according to the present invention in which a workpiece is brought into close contact with a punch die And FIG. And FIG. 2C shows an embodiment of a position where a workpiece is fixed by a collet chuck and a hole is machined.

2A, the press working apparatus 20 includes a collect chuck 21 to which a workpiece M of a secondary piston is fixed, a collet chuck 21 fixed to one end thereof, And may include a cylinder 25. The collet chuck 21 may have a suitable shape to hold the workpiece M and the adjustment cylinder 25 may have any shape that allows the collet chuck 21 to be fixed. The adjustment cylinder 25 can be rotated by a rotary motor 22, such as a servo motor, for example, and can be moved laterally by the movement motor 23. Specifically, a rotary roller 222 may be installed at a predetermined position in the longitudinal direction of the control cylinder 25, and an adjustment roller 221 may be coupled to the shaft of the rotary motor 22. The regulating cylinder 25 is rotatably fixed by a rotating roller 222 and the regulating roller 221 and the rotating roller 222 can be connected by a power transmitting means 223 such as a belt or a chain . The rotary motor 22 may be, for example, but not limited to, a servo motor or a step motor whose rotational angle can be controlled. If necessary, adjustment means such as a reduction gear may be provided to adjust the ratio between the rotation angle of the rotation motor 22 and the rotation angle of the rotation roller 222.

The rotation angle of the rotary motor 22 can be transmitted to the rotary roller 222 via the adjustment roller 221 so that the adjustment cylinder 25, the first collet 21 and the workpiece M are sequentially . The rotation of the adjusting cylinder 25 and thus the workpiece M is for machining holes along the peripheral surface of the workpiece M. [

The workpiece M fixed to one end of the collet chuck 21 may be fixed to the punch die described in Figs. 1A and 1B in accordance with the lateral movement of the adjustment cylinder 25. Fig. A moving motor 23 may be installed on the other side of the adjusting cylinder 25 and a clamp stop bar 232 may be provided between the moving motor 23 and the adjusting cylinder 25. [ The clamp stop bar 232 can be installed in a structure that can be connected to and disconnected from the other end of the adjustment cylinder 25. On the other hand, a floating joint 231 can be installed on the axis of the moving motor 23 and a floating joint 231 can be connected with the clamp stop bar 232. The moving distance of the adjusting cylinder 25 or the collet chuck 21 can be adjusted by the clamp stop bar 232 and the moving joint 231 can be connected to the moving motor 25 regardless of the rotation of the adjusting cylinder 25, It is possible to maintain the connection state with the connector 23. On the other hand, a movement guide 26 is provided below the regulation cylinder 25 and can be moved forward and backward by the rotation of the movement motor 23. The adjusting cylinder 25 and the rotating motor 22 can be fixed to the moving guide 26 and moved together.

When the moving motor 23 is driven, the moving guide 26 can be moved forward, so that the adjusting cylinder 25 and the rotating motor 22 can be moved forward. Then, the workpiece M can be fixed to the punch die provided in the first press die 10.

2B, the workpiece M fixed to the collet chuck 21 can be fixed to the punch die 11a. The workpiece M can be fixed to maintain the cross-section perpendicular to the punch die 11a and can be fixed to the punch die 11a by repeating the clamping and un- Such as a punch guide bearing installed in the inside of the guide unit 112. When the workpiece M is fixed to the punch die 11a, the holes can be machined while the hole punch 12 is moved up and down along the guide 18.

As shown in FIG. 2C, the punch die 11a may have a positioning hole 114 for allowing a relative position to be determined in the process of assembling the press die. When the punch die 11a is assembled to the press mold by the positioning hole 114, the hole punch is correctly positioned in the punch reference hole 113. [ And the workpiece may be guided along a guide unit 112, such as a punch guide bearing. The workpiece is brought into close contact with the guide unit 112 and held perpendicular to the hole punch. Thereafter, the hole can be machined by the upward and downward movement of the hole punch.

When sixteen holes are machined, a rotary motor 22 such as a servo motor rotates the control cylinder 25 by 22.5 degrees to process holes along the peripheral surface of the workpiece M. [ The adjustment cylinder 25 can be either forward or reverse and each hole can be formed along the circumferential surface of the workpiece M by the hole punch 12a according to forward or reverse rotation of the adjustment cylinder. The holes can be machined in turn on the workpiece M by reverse rotation or forward movement of the collet chuck 21 and the holes can be machined without generating burrs with inner diameters such as, for example, milling.

When the hole set having sixteen holes is completed, the adjusting cylinder 25 can be moved backward by the rotation of the moving motor 23. The workpiece on which the hole set has been formed can then be transferred to the outer diameter finishing device 24. The outer diameter finishing device 24 may have a device for determining a position for a hole operation or a position of a brush and the outer diameter of the hole in the outer diameter finishing device 24 may be machined into an oval shape by a brush so that there is no outer diameter burr Can be processed.

3 shows an embodiment of the shape of the hole of the secondary piston manufactured by the method according to the present invention.

Referring to FIG. 3, a hole set 32 may be formed along the peripheral surface in front of the body 31 of the secondary piston 30. The hole set 32 may include, for example, sixteen holes and may have a shape that penetrates from the inside to the outside. The burr of the hole set 32 can be formed mainly on the upper side 33a or the lower side 33b of the interface between the body 31 and the hole. According to the present invention, the burr, which may be formed in the lower portion 33b, can be prevented by machining the hole by forward rotation or reverse rotation of the regulating cylinder. On the other hand, the burr formed on the upper portion 33a can be removed by fixing the fine round by the brush.

As described above, according to the present invention, by firmly fixing the workpiece to the punch die by the collet chuck, the punching phenomenon that may occur in the press working can be prevented. Also, each hole of the hole set is formed by forward rotation and reverse rotation, and burrs are not caused by post-processing by the brush.

The manufacturing method according to the present invention can solve the problems caused by excessive processing time generated in the piston manufacturing process of the master cylinder, lowering of productivity due to generation of burr in the machining area, and increase in investment cost for processing equipment . Specifically, the method for machining a secondary piston by press working according to the present invention has an advantage in that productivity and quality can be improved by allowing holes of at least two secondary pistons to be simultaneously machined.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention . The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

10: press mold 20: press working device
11a and 11b: punch dies 12a and 12b: hole punches
13a, 13b: Support member 14: Die holder
15: frame member 16: guide member
17: Fixed holder 18: Punch guide
21: collet chuck 22: rotary motor
23: moving motor 24: outer diameter finishing device
25: Adjusting cylinder 26: Moving guide
30: Secondary piston 31: Body
32: Hall set
111: stop bar guide 112: guide unit (bearing)
113 punch reference hole 114: positioning hole
221: regulating roller 222: rotating roller
223: Power transmission means 231: Floating joint
232: Clamp stop bar

Claims (3)

1. A precision machining method of a secondary piston applied to an automotive master cylinder,
Preparing a press mold (10) having punch dies (11a, 11b) and hole punches (12a, 12b);
Preparing a press working apparatus having a collect chuck (21) to which a workpiece (M) of a secondary piston is fixed;
Advancing the collect chuck 21 to be in close contact with the punch dies 11a and 11b and machining the holes with the hole punches 12a and 12b; And
Removing the burr generated in the outer diameter of the workpiece (M) of the secondary piston with a brush,
The collet chuck 21 is connected to a regulating cylinder 25 which is capable of moving to the left and right and the rotation of the regulating cylinder 25 is regulated by a rotary motor 22 via an regulating roller 221, A moving motor 23 is provided on the other side of the adjusting cylinder 25 and a clamp stop bar 232 is provided between the moving motor 23 and the adjusting cylinder 25 so that the adjusting cylinder 25 or the collet chuck 21 The moving distance is adjusted and moved together with the rotating motor 22 by the moving guide 26 which is provided below the adjusting cylinder 25 and is moved by the moving motor 23 and the moving of the adjusting cylinder 25 The collet chuck 21 is brought into close contact with the punch dies 11a and 11b by the repetition of clamping and un-clamping and the collet chuck 21 is rotated by the rotation motor 22 And the holes are machined by the hole punches 12a and 12b at the divided angles, Burr-free precision machining method of the secondary piston by a press mold. The method of precisely machining a burr precursor of a secondary piston according to claim 1, wherein the punch dies (11a, 11b) are paired so that the holes are machined simultaneously on the pair of punch dies. The method according to claim 1, wherein the hole punches (12a, 12b) have punch reference holes (113) for hole machining.

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