KR101669080B1 - Cylinder manufacturing method for pop-up bonnet of automobile - Google Patents

Cylinder manufacturing method for pop-up bonnet of automobile Download PDF

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Publication number
KR101669080B1
KR101669080B1 KR1020150088241A KR20150088241A KR101669080B1 KR 101669080 B1 KR101669080 B1 KR 101669080B1 KR 1020150088241 A KR1020150088241 A KR 1020150088241A KR 20150088241 A KR20150088241 A KR 20150088241A KR 101669080 B1 KR101669080 B1 KR 101669080B1
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KR
South Korea
Prior art keywords
forming
workpiece
processed product
cold forging
cylinder
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KR1020150088241A
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Korean (ko)
Inventor
장희복
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혜성금속공업주식회사
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Priority to KR1020150088241A priority Critical patent/KR101669080B1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
    • B21K3/00—Making engine or like machine parts not covered by sub-groups of B21K1/00; Making propellers or the like
    • B21K3/02—Making engine or like machine parts not covered by sub-groups of B21K1/00; Making propellers or the like cylinder heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
    • B21J5/02—Die forging; Trimming by making use of special dies ; Punching during forging
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/34—Protecting non-occupants of a vehicle, e.g. pedestrians
    • B60R21/38—Protecting non-occupants of a vehicle, e.g. pedestrians using means for lifting bonnets

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Forging (AREA)

Abstract

The present invention relates to a method of manufacturing a cylinder for a pop-up bonnet of an automobile, comprising: a material cutting step of obtaining a material by cutting a round bar by a fixated length; a step of forming a protruding frame whose cross sectional area gradually increases toward a lower part on an outer surface of an upper part of the cut material through cold forging, and forming a primary workpiece by forming a lower groove with a fixated depth at a center of a lower part; a step of forming a secondary workpiece by forming a protruding frame of the primary workpiece to have an external diameter greater than an external diameter of a lower part through cold forging, and at the same time, forming an upper grove having an internal diameter greater than an external diameter of a lower part at a center of an upper part of the primary workpiece to be recessed in a fixated depth; a step of forming a tertiary workpiece having a head by forming a first internal circumferential groove in the protruding frame of the secondary workpiece through cold forging; a step of forming a quarternary workpiece by forming a second internal circumferential groove by extending the first internal circumferential groove of the tertiary workpiece toward a lower part of the tertiary workpiece through cold forging; a step of forming a fifth workpiece having a chamber by forming the second internal circumferential groove of the quarternary workpiece to be extended to be adjacent to the lower groove through cold forging; and a step of obtaining the cylinder by supplying the fifth workpiece to a rotary mold, and pressing the fifth workpiece while rotating the rotary mold. The method of the present invention is able to reduce manufacturing costs, and is able to improve productivity.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder manufacturing method for an automobile pop-up bonnet, and more particularly, to a method for manufacturing a cylinder for a car pop-up bonnet by cold forging.

In recent years, the development of safety devices that actively protect the safety of pedestrians beyond the merit of simply protecting the safety of passengers is becoming more active.

For example, a vehicle body has been developed in which a shock absorbing space is provided between an engine and a bonnet (hood) of an automobile, the bonnet and the windshield portion are easily deformed to absorb shocks, and the injury of pedestrians is reduced.

The car bonnet itself is a thin sheet metal, so there is not a lot of shock, and there is a minimum space of 10 cm between the bonnet and the engine to reduce the pedestrian's injury when the pedestrian collides, but it is not enough to absorb all of the impacts on the pedestrian.

Accordingly, in recent years, a technique of making a shock absorbing space between the bonnet and the engine through a pop-up device that raises the rear portion of the bonnet when the vehicle collides with a pedestrian during the operation of the vehicle is applied.

Thus, when the bonnet rises at the time of collision, not only the space between the engine and the bonnet becomes much larger, but also the head of the pedestrian can be prevented from hitting the windshield of the automobile, so that the injury of the pedestrian can be alleviated.

A cylinder for lifting the bonnet is used for the pop-up bonnet of such a car.

Conventional cylinders for pop-up bonnets of automobiles must be manufactured within a certain range of straightness and surface roughness of the cylinder itself so as to smoothly operate at a momentary impact.

On the other hand, the conventional cylinder for a pop-up bonnet of automobiles is manufactured through cutting such as roughing, turning, and grinding after cutting a round bar into a predetermined size. Therefore, a cylinder having a straightness, roundness, It is difficult to manufacture a cylinder, and a considerable amount of material loss occurs when the cylinder is machined, which is uneconomical.

In addition, the processing cost is increased by the processing amount of the material, so that the manufacturing cost is increased and the processing time is increased, resulting in a decrease in productivity.

Korean Patent Registration No. 10-1076616 (entitled " Method for manufacturing an adapter for an oil filter, published on Oct. 26, 2011)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cylinder for an automobile pop-up bonnet capable of reducing defects in straightness, roundness and surface roughness, reducing loss of materials, And a method for producing the same.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of cutting a circular rod, Forming a protruding frame whose sectional area is gradually increased toward the lower end on the outer surface of the upper end of the cut material through the cold forging and forming a lower end groove having a certain depth in the center of the lower end to form the primary workpiece; The upper end of the primary processed product is formed to have an outer diameter larger than the outer diameter of the lower end through cold forging, and an upper end groove having an inner diameter larger than the outer diameter of the lower end portion is formed in the center of the upper end portion of the primary processed product, Thereby forming a secondary workpiece; Forming a first inner circumferential groove in the protruding frame of the secondary work through cold forging to form a third workpiece having a head; Forming a first inner circumferential groove of the third processed product through a cold forging to form a second inner circumferential groove extending toward a lower end of the third processed product to form a fourth processed product; Extending the second inner circumferential groove of the fourth processed product through the cold forging so as to be adjacent to the lower end groove to form a fifth processed product having a chamber; And supplying the fifth processed product to the rotating mold and pressing the fifth processed product while rotating the rotating mold to obtain a cylinder.

Here, the protruding frame of the primary processed product has a ring shape of a conical section, and the protruding frame of the secondary processed product and the head may have a ring shape of a circular section.

According to the present invention, by manufacturing through cold forging, defects in straightness, roundness, and surface roughness can be reduced, material loss can be reduced, manufacturing cost can be reduced, and productivity can be improved.

1 is a perspective view of a cylinder manufactured by a cylinder manufacturing method for an automobile pop-up bonnet according to the present invention,
FIG. 2 is a step-by-step manufacturing process of a cylinder for a car pop-up bonnet according to the present invention,
3 is a cross-sectional view showing a molding state of each cylinder for a car pop-up bonnet according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Before describing a manufacturing process of a cylinder for an automobile pop-up bonnet according to the present invention, the structure of a cylinder for a car pop-up bonnet manufactured by the method for manufacturing a cylinder for a car pop-up bonnet according to the present invention will be described.

As shown in Fig. 1, a cylinder 10 for an automobile pop-up bonnet has a rod shape having a predetermined length with a step on its outer periphery. A head 53 is protruded from the outer periphery of one end of the cylinder 10 and a chamber 75 is provided on the inner circumference of the cylinder 10 to receive cylinder pins (not shown).

Hereinafter, a manufacturing process of the cylinder 10 for an automobile pop-up bonnet according to the present invention will be described with reference to FIGS. 2 and 3. FIG.

A method of manufacturing a cylinder for a car pop-up bonnet (10) according to the present invention includes a step of cutting a material, a step of forming a first processed product, a step of forming a second processed product, a step of forming a third processed product, And obtaining a cylinder.

Hereinafter, each step will be described in detail.

In the material cutting step, as shown in Figs. 2 (a) and 3 (a), the round bar is cut to a predetermined length to obtain the material 20.

In the primary processed product forming step, after the blank 20 is fed into the cold forging dies 130a and 130b, the blank 20 is pressed by using the punch pin 133, A protruding frame 33 is formed on the outer surface of the upper end of the cut material 20 and a lower end groove 35 having a predetermined depth is formed in the center of the lower end of the cut material 20, 30).

The projecting frame 33 has a sectional shape gradually increasing in cross section toward the lower end of the work 20, for example, a ring shape having a conical cross section.

Although the lower end groove 35 is shown as having a V-shaped cross-sectional shape in the present embodiment, the lower end groove 35 is not limited to this, and the lower end groove 35 may have a cross- It can have a cross sectional shape that gradually decreases.

Thus, by forming the protruding frame 33 whose sectional area gradually increases toward the lower end on the outer surface of the upper end of the cut material 20 prior to molding the head 53 of the cylinder 10, The flowability of the metal material constituting the protruding frame 33 is increased during cold forging using the forming machine so that the protruding frame 33 can be stably fixed in a circular ring shape without interruption of the short- So that it can be molded. In addition, the length of the primary processed product 30 is reduced relative to the workpiece 20 due to the formation of the protruding frame 33, while the thickness of the primary processed product 30 is increased.

The primary processed product 30 is supplied into the cold forging dies 140a and 140b and then the primary processed product 30 is pressed using the punch pin 143 to obtain the The projecting frame 33 of the primary processed product 30 is formed to have an outer diameter larger than the outer diameter of the lower end portion and the center of the upper end portion of the primary processed product 30 An upper groove 45 having an inner diameter larger than the outer diameter of the lower end portion is recessed at a predetermined depth to obtain a secondary finished product 40.

Here, the protruding frame 33 of the secondary processed product 40 has a ring shape of a circular section.

As described above, the head 53 of the cylinder 10 can be secured by forming the protruding frame 33 in the shape of a ring having a circular section in the secondary molded product molding step. In addition, the length of the secondary processed product 40 is reduced relative to the primary processed product 30 due to the shape change of the protruding frame 33, while the thickness of the secondary finished product 40 is increased.

In the third processed product forming step, the secondary finished product 40 is supplied into the cold forging dies 150a and 150b and then the secondary finished product 40 is pressed using the punch pin 153 to obtain A first inner circumferential groove 55 is formed inside the protruding frame 33 of the secondary processed product 40 to form a third processed product having the head 53 as shown in Fig. 50).

The length of the third processed product 50 is relatively longer than that of the second processed product 40 due to the formation of the first inner peripheral groove 55, while the thickness of the third processed product 50 is reduced.

Here, the head 53 has a ring shape of a circular section.

The fourth processed product forming step is a step in which the third processed product 50 is supplied into the cold forging dies 160a and 160b and then the third processed product 50 is pressed using the punch pin 163, The first inner circumferential groove 55 of the third processed product 50 is formed with the second inner circumferential groove 65 extending toward the lower end to form the fourth processed product 60 (see Fig. 3 (e) ).

The fourth processed product 60 has a relatively longer length and a smaller thickness than the third processed product 50 due to the formation of the second inner peripheral groove 65. [

The fourth processed product 60 is supplied into the cold forging molds 170a and 170b and the second inner circumferential groove 65 is formed adjacent to the lower end groove 35 by using the punch pin 173. [ The fourth processed product 60 is pressed to obtain the fifth processed product 70 having the chamber 75 as shown in Figs. 2 (f) and 3 (f).

The fifth processed product 70 is elongated in length relative to the fourth processed product 60 due to the formation of the chamber 75, while the thickness tapers.

The step of obtaining the cylinder includes supplying the fifth processed product 70 into the rotating molds 180a 180b and 180c and rotating the rotating molds 180a 180b and 180c while moving the outer periphery of the fifth processed product 70 and the outer periphery of the chamber 75 The cylinder 10 for the automobile pop-up bonnet is obtained, as shown in Figs. 2 (g) and 3 (g).

As described above, by pressing the fifth processed product 70 by the rotary molds 180a, 180b, and 180c, it is possible to obtain a cylinder 10 that is precise in straightness and roundness and excellent in surface roughness.

Thus, the method for manufacturing the cylinder 10 for a car pop-up bonnet according to the present invention is completed.

As described above, according to the present invention, the mold is manufactured by cold forging rather than machining, and in particular, the mold is rotated and pressed to improve the straightness, roundness, and surface roughness of the cylinder, whereby defects in straightness, roundness, The manufacturing cost can be reduced, and the productivity can be improved.

Further, since the cylinder manufactured in accordance with the present invention is manufactured through cold forging, the toughness and durability of the cylinder can be increased by keeping the short-circuited line (flow of the metal structure) uninterrupted as compared with the cylinder produced by machining.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

10: Cylinder for automobile pop-up bonnet 20: Material
30: First processed product 33:
35: bottom groove 40: secondary finished product
45: upper groove 50: third processed product
53: head 55: first inner peripheral groove
60: Fourth machined piece 65: Second inner groove
70: 5th machined part 75: chamber

Claims (2)

A material cutting step of cutting the round bar into a predetermined length to obtain a material;
Forming a protruding frame whose sectional area is gradually increased toward the lower end on the outer surface of the upper end of the cut material through the cold forging and forming a lower end groove having a certain depth in the center of the lower end to form the primary workpiece;
The upper end of the primary processed product is formed to have an outer diameter larger than the outer diameter of the lower end through cold forging, and an upper end groove having an inner diameter larger than the outer diameter of the lower end portion is formed in the center of the upper end portion of the primary processed product, Thereby forming a secondary workpiece;
Forming a first inner circumferential groove in the protruding frame of the secondary work through cold forging to form a third workpiece having a head;
Forming a first inner circumferential groove of the third processed product through a cold forging to form a second inner circumferential groove extending toward a lower end of the third processed product to form a fourth processed product;
Extending the second inner circumferential groove of the fourth processed product through the cold forging so as to be adjacent to the lower end groove to form a fifth processed product having a chamber; And
Supplying the fifth processed product to a rotating mold and pressing the fifth processed product while rotating the rotating mold to obtain a cylinder,
Wherein the protruding frame of the primary processed product has a ring shape of a conical cross section and the protruding frame of the secondary processed product and the head have a ring shape of a circular cross section.
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KR1020150088241A 2015-06-22 2015-06-22 Cylinder manufacturing method for pop-up bonnet of automobile KR101669080B1 (en)

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KR101669080B1 true KR101669080B1 (en) 2016-10-25

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102303484B1 (en) * 2020-10-05 2021-09-16 김출곤 The cutout groove molding/metal patterns of the anchor rivet and anchor rivet manufacturing method using the same
KR102560003B1 (en) * 2023-02-24 2023-07-25 백승현 Method of manufacturing rice cooker inner lid handle

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102303484B1 (en) * 2020-10-05 2021-09-16 김출곤 The cutout groove molding/metal patterns of the anchor rivet and anchor rivet manufacturing method using the same
KR102560003B1 (en) * 2023-02-24 2023-07-25 백승현 Method of manufacturing rice cooker inner lid handle

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