KR20180109258A - A Manufacturing Apparatus Of Hot Forged Product For Bearing Having A Flange With Medium Carbon Steel And The Method Thereof - Google Patents

Abstract

A method for manufacturing a hot forging product for a bearing having a flange according to the present invention includes a preheating step for preheating a material made of medium carbon steel, a forging step for molding the preheated material into a semi-finished product, a control cooling step for controlling the texture of the semi-finished product molded in the forging step, and a processing step for processing the texture-stabilized semi-finished product into a bearing forging product. The processing step includes a high frequency heat treatment step for hardening a trajectory part and performing high frequency heat treatment on the semi-finished product, and a step for grinding the semi-finished product after the high frequency heat treatment. The control cooling step is executed while the forged and molded semi-finished product is conveyed by a conveyor unit provided with a cover covering both width-direction sides and the upper portion in the upper portion. The texture of the forged and molded semi-finished product is stabilized by means of the latent heat of the forged and molded semi-finished product.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a hot forged product for a bearing having a flange made of a carbon steel,

The present invention relates to an apparatus and a method for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel and a method for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel in which the structure is uniform, And a manufacturing method thereof.

As shown in Figs. 1 and 2, a bearing having a flange is made up of an outer member 3, an inner member 1, and a rolling member 8. As shown in Fig. In Fig. 1, the transverse direction is the axial direction.

On the inner peripheral surface of the outer member 3, two raceways 3a and 3b are formed.

On the outer circumferential surface of the inner member 1, raceway surfaces 1a and 1b opposed to the raceways 3a and 3b of the outer member 2 are formed. The raceway surfaces 1a and 1b may not be formed on the outer circumferential surface of the inner member 1 and a separate inner ring member may be mounted. The inner member (1) is formed with a spline hole (9) penetrating in the axial direction. At one side of the outer circumferential surface of the inner member (1), a flange (2) extending in the radial direction is provided. The flange (2) is provided integrally with the inner member (1).

Of the two raceways 1a and 1b of the inner member 1, the outer raceway surface 1a is formed directly on the outer circumferential surface of the inner member 1, while the inner raceway surface 1b is formed on the outer circumferential surface of the hub wheel 14 Is formed on a separate inner ring (15) that fits into a shoulder formed at one end.

The rolling member 8 is provided in two rows between the outer member 3 and the inner member 1. [

The inner member 1 of the bearing with the flange is manufactured in the manner as shown in Fig. A medium carbon steel (0.4 to 0.7 wt% carbon-containing) is used as the material used for manufacturing the inner member (1).

The method for manufacturing the inner member 1 may include a step of cutting a material, a preheating step ST-10, a forging step ST-20, a forced cooling step ST-30, .

In the material cutting step, the material is cut to a predetermined size.

In the pre-heating step (ST-10), the cut material is preheated to a temperature suitable for forging. In the pre-heating step (ST-10), the preheating temperature is preheated to a range of, for example, 1150 to 1250 ° C.

In the forging step (ST-20), the heated material is pressed by a die in a forging press and hot forging is performed.

In the forced cooling step (ST-30), the semi-finished product, which is hot forged and has a temperature of 950 to 1050 캜, is forcedly cooled to 400 캜 using a fan or an exhaust device. The cooling time to be cooled to 400 ° C in the forced cooling step (ST-30) takes about 1 minute.

After the semi-finished product P is forcedly cooled, it is cooled to room temperature (25 ° C) and then the processing step ST-40 is executed.

The machining step ST-40 comprises a turning step ST-41, a high-frequency heat treatment step ST-43 and a post-machining step ST-45.

In the turning step (ST-41), the trajectory portion of the semi-finished product is turned.

In the high-frequency heat treatment step (ST-43), high-frequency heat treatment is performed on the trajectory portion of the semi-finished product. The heat-treated portion is hardened through the high-frequency heat treatment. In Fig. 2, the shaded portions 21 and 22 are portions cured by the high-frequency heat treatment.

In the post-processing step (ST-45), the hardened portion is processed through high-frequency heat treatment. In the post-processing step (ST-45), grinding is performed and super finishing after grinding can be performed.

The material is passed from the material cutting step to the flange post-processing step (ST-45), and the inner member 1 having the flange is manufactured. The inner member 1 is described, but the outer member 3 is manufactured in the same manner. Then, the inner member 1 is assembled with bearings together with components such as rolling members, retainers, and the like.

The conventional hot forging for bearings with internal member 1 and external member 3, that is, a flange made of medium carbon steel, includes coarse structure and the structure is uneven, and after assembly (ST-45) The plastic deformation is difficult and plastic cracking occurs when the plastic deformation is required.

Korean Registered Patent No. 10-1037742 (May 23, 2011)

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems, and it is an object of the present invention to provide a bearing having a flange made of a medium carbon steel in which plastic deformation is easy and cracks are prevented by plastic deformation, An object of the present invention is to provide a hot forging product manufacturing apparatus and a manufacturing method thereof.

The method for manufacturing a hot forging product for a bearing having a flange according to the present invention includes a preheating step for preheating a material made of medium carbon steel, a forging step for molding the preheated material into a semi-finished product, A control cooling step, and a machining step for machining the tissue-stabilized semi-finished product into a bearing forging;

Wherein the machining step includes a high frequency heat treatment step of hardening a part to be trajectory and subjecting the semi-finished product to a high frequency heat treatment, and a step of grinding the high frequency heat treated semi product;

In the control and cooling step, the forged semi-finished product is conveyed while being conveyed by a conveyor portion having a cover covering both sides in the width direction and the upper portion on the upper side. The latent heat of the forged semi-finished product is used to stabilize the structure of the forged- The present invention provides a method of manufacturing a hot forging product for a bearing having a flange.

In the above, in the preheating step, the workpiece is heated to a temperature in the range of 1050 to 1250 ° C, and the heated workpiece is formed into a formed semi-finished article in the forging step;

And the surface temperature of the molded semi-finished product which is detached from the conveyor portion is in the range of 500 to 600 캜.

The apparatus for manufacturing a hot forging product for a bearing having a flange according to the present invention comprises a heating device for preheating a material, a forging device provided at one side of the heating device for forming a heated material, a conveyor Made of wealth;

Wherein the conveyor portion is provided with a cover which covers both sides and upper portions of the semifinished product to be conveyed and has both ends in the conveying direction of the conveyor portion opened.

The hot forging product manufactured by the apparatus for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention is finely and uniform in structure and is easily deformed when plastic working is required by assembling after completion of post- , Cracking due to plastic deformation is prevented.

1 is a cross-sectional view of an assembly of a bearing with a conventional flange,
2 is a cross-sectional view showing an inner member of a bearing having a conventional flange,
3 is a flowchart showing a method of manufacturing a conventional forged bearing for a bearing having a flange,
4 is a flowchart illustrating a method of manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention,
5 is a cross-sectional view of a hot forging product manufacturing apparatus for a bearing having a flange made of medium carbon steel according to the present invention,
6 is a cross-sectional view schematically showing an apparatus for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and method for manufacturing a hot forging product for a bearing having a flange according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a flowchart showing a method of manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention, and FIG. 5 is a view showing a device for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention And FIG. 6 is a cross-sectional view schematically showing an apparatus for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention.

5 and 6, an apparatus 100 for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention includes a heating device (not shown), a forging device A conveyor section 110, and a collecting section 120. [

As the material for manufacturing the hot forging product for a bearing manufactured by the above-described apparatus for manufacturing a forging hot forging bearing 100, medium carbon steel or the like is used. The heavy carbon steel contains 0.4 to 0.7% by weight of carbon.

The heating device comprises a furnace or a high frequency heater. In the heating device, the workpiece is preheated for forging. The material is charged into the heating device and heated. In the heating apparatus, the material is heated to a temperature in the range of 1050 to 1250 占 폚.

The forging device is provided on one side of the heating device. The forging device comprises a die and a punch. In the forging apparatus, the material heated by the heating apparatus is pressed and forged. And the material is formed into a molded semi-finished product (P) by the forging apparatus.

The conveyor part 110 is provided at one side of the forging device. And the forged molded semi-finished product P is conveyed from the conveyor part 110. [ The conveyor unit 110 includes a first main roller 111, a second main roller 113, a support roller 117, a return roller 119, a belt 115, a bracket 112, And a cover 114.

In FIG. 6, a description will be made assuming that the horizontal direction is the "longitudinal direction", the vertical direction is the "vertical direction", and the direction perpendicular to the paper is the "width direction".

The first main roller 111 and the second main roller 113 are spaced apart from each other in the longitudinal direction. The rotation axes of the first main roller 111 and the second main roller 113 are rotatably mounted on the bracket 112.

A motor is connected to the rotating shaft of the first main roller 111, and the motor is connected to the control unit and the operation of the motor is controlled by the control unit. Accordingly, the rotational speed of the motor is controlled and the rotational speed of the first main roller 111 is adjusted according to the control of the controller.

The support roller 117 is provided between the first main roller 111 and the second main roller 113. A plurality of the support rollers 117 are provided. The support rollers 117 are spaced apart in the longitudinal direction. The rotation shaft of the support roller 117 is rotatably provided on the bracket 112.

The support roller 117 is in rolling contact with the belt 115 at its upper portion and supports the lower portion of the belt 115 when the belt 115 rotates.

The return roller 119 is provided between the first main roller 111 and the second main roller 113. The plurality of return rollers 119 are provided. The return rollers 119 are spaced longitudinally apart. The rotation axis of the return roller 119 is rotatably provided on the bracket 112.

The rotation axis of the return roller 119 is positioned lower than the rotation axis of the support roller 117. The rotation axis of the return roller 119 is disposed at a position shifted from the rotation axis of the support roller 117.

The return roller 119 is in contact with the belt 115 at its lower portion or upper portion and is in rolling contact with the upper portion of the belt when the belt 115 rotates to prevent belt sagging.

The belt 115 is wound around the first main roller 111 and the second main roller 113. The belt 115 is provided with a closed circuit. The length of the belt 115 in the longitudinal direction may be in the range of 5 to 15 m. For example, the length of the belt 115 in the longitudinal direction is 10 m. The belt 115 is made of a metal such as steel. At the upper portion of the belt 115, a plurality of molded semi-finished products P are simultaneously moved. The molded semi-finished products P are moved away from each other in the width direction and the longitudinal direction of the belt 115, or a plurality of molded semi-finished products P are stacked and moved.

The bracket 112 is provided in a plate shape. The bracket 112 extends in the longitudinal direction. Two brackets 112 are provided and spaced apart from each other in the width direction between the rollers. The lower portion of the bracket 112 is fixed to the ground or the like. A roller is provided between the brackets 112, and the rotation axis of the roller is rotatably fixed.

The cover 114 is plate-shaped, and both ends in the width direction are formed by being bent downward. The cross section of the cover 114 is formed in the form of " The cover 114 is formed so that both longitudinal ends thereof are open. The cover 114 extends in the longitudinal direction. For example, the size of the cover 114 is 400 mm in the width direction and 400 mm in the vertical direction.

The cover 114 is made of a metal such as steel. The lower end of the cover 114 is fixed to the bracket 112. The cover 114 is provided to cover both sides and upper portions of the molded semi-finished product P conveyed from the upper portion of the belt 115.

The thickness of the cover 114 is in the range of 2 to 4 mm. If the thickness of the cover 114 is thinner than 2 mm, the heat released from a plurality of the semi-finished products P is quickly released to the outside, so that it is difficult to adjust the internal temperature for stabilizing the structure of the semi-finished product P, If it is thicker, the release of heat is slowed and the manufacturing time becomes longer.

Therefore, the thickness of the cover 114 is in the range of 2 to 4 mm to prevent rapid release of heat radiated from the plurality of molded semi-finished products P to the outside, thereby slowly cooling the molded semi-finished product P.

The provision of the cover 114 allows the molded semi-finished product P in the conveyor part 110 to be sufficiently cooled naturally by the latent heat of the semi-finished product P when the hot forging product for bearing is manufactured. The surface temperature of the semi-finished product P discharged from the conveyor part 110 is in the range of 500 to 600 캜.

The forgings for bearings manufactured using the apparatus for manufacturing a hot forging product for a bearing 100 are manufactured as shown in Fig.

A method for manufacturing a hot forging product for a bearing having a flange according to the present invention includes a cutting step, a preheating step (ST-110), a forging step (ST-130), a control cooling step (ST- (ST-170).

In the material shearing step, the material is sheared to a predetermined size. As the material, heavy carbon steel containing 0.4 to 0.7 wt% of carbon is used.

In the pre-heating step (ST-110), the cut material is put into a heating apparatus and preheated. In the pre-heating step (ST-110), the material is heated to a temperature in the range of 1050 to 1250 ° C.

In the forging step (ST-130), the preheated material in the heating device is pressurized and molded into a semi-finished product (P). The molded semi-finished product P is discharged to the conveyor part 110 located at one side of the forging device. At this time, the surface temperature of the semi-finished product P is discharged in a range of 900 to 1100 ° C.

In the control cooling step ST-150, the forged semi-finished product P is naturally cooled sufficiently by the latent heat of the semi-finished product P at the conveyor part 110. The semi-finished product P passes through the conveyor part 110 and is gradually cooled to stabilize the structure.

The rotational speed of the belt 115 of the conveyor part 110 is kept constant. The surface temperature of the molded semi-finished product P which is detached from the conveyor part 110 is discharged in the range of 500 to 650 占 폚. Preferably, the surface temperature of the molded semi-finished product P which is separated from the conveyor part 110 is discharged in the range of 500 to 600 캜. The conveying time of the conveyor part 110 is controlled to be in the range of 5 minutes to 27 minutes. The time to be conveyed by the conveyor part 110 is preferably controlled to be in the range of 7 minutes to 22 minutes.

In the control cooling step ST-150, the molded semi-finished product P is sufficiently naturally cooled in the conveyor part 110 so that the grain size of the structure becomes 50 to 150 mu m, 175), plastic deformation is easy when plastic working is required for assembly and the like, and occurrence of cracks in plastic deformation is prevented.

The semi-finished product P discharged from the conveyor unit 110 through the control cooling step ST-150 is loaded on the upwardly opened collecting box 120 and gradually cooled at room temperature. The semi-finished product P discharged from the conveyor part 110 may be loaded on the collecting box 120 and the collecting box 120 may be closed and cooled.

In the processing step (ST-170), the stabilized semi-finished product is processed into a hot forging product for a bearing. The machining step ST-170 includes a second machining step ST-171, a high-frequency heat treatment step ST-173, and a third machining step ST-175.

In the secondary processing step (ST-171), the trajectory portion of the semi-finished product passed through the control cooling step (ST-150) is turned or cold-forged.

In the high-frequency heat treatment step (ST-173), a high-frequency heat treatment is performed on the trajectory portion of the semi-finished product subjected to turning or cold forging. The orbital surface layer heat-treated through the high-frequency heat treatment is cured.

In the third machining step (ST-175), the high-frequency heat-treated semi-finished product is ground or superfinished after grinding to complete a hot forging product for a bearing.

The apparatus and method for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel according to the present invention have been described with reference to the embodiments shown in the drawings but are merely illustrative, And other equivalent embodiments are possible. Accordingly, the scope of the true technical protection should be determined by the technical idea of the appended claims.

100: a device for manufacturing a hot forging product for a bearing having a flange made of medium carbon steel
110: conveyor part 111: first main roller
112: Bracket 113: Second main roller
114: cover 115: belt
117: Support roller 119: Return roller
120: Collected

Claims (3)

(ST-110) for pre-heating a material made of carbon steel, a forging step (ST-130) for molding the preheated material into a semi-finished product, and a control for controlling the structure of the formed semi-finished product in the forging step (ST-130) (ST-150), and a processing step (ST-170) for processing the stabilized semi-finished product into a forgings for bearings;
In the control and cooling step (ST-150), the forged semi-finished product is conveyed while being conveyed by the conveyor part (110) provided with a cover (114) covering the upper and lower sides in the width direction. Wherein the structure of the forged semi-finished product is stabilized by using the carbon steel. The method according to claim 1, wherein in the preheating step (ST-110), the workpiece is heated to a temperature in the range of 1050 to 1250 ° C, and the heated workpiece is formed into a formed semi-finished product in the forging step (ST-130);
Wherein the surface temperature of the semi-finished product which is detached from the conveyor part (110) is in the range of 500 to 600 占 폚. A heating device for preliminarily heating the material, a forging device provided at one side of the heating device for molding the heated material, and a conveyor part for conveying the forged semi-finished product;
Wherein the conveyor part (110) is provided with a cover (114) covering both sides and an upper part of the semi-finished product to be conveyed and having both ends in the conveying direction of the conveyor part (110) Hot forging manufacturing equipment.

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