KR20180126104A - Manufacturing method of sector gear - Google Patents

Abstract

The present invention relates to a manufacturing method of a sector gear which can significantly reduce a time and a cost required for manufacturing while maintaining a mechanical rigidity. According to an embodiment of the present invention, the manufacturing method of a sector gear comprises: a blanking process of cutting a metal plate having a predetermined shape in which a circular arc part is formed at one edge from a base material; a bending process of bending the circular arc part of the metal plate; a local part heating process of heating the cut circular arc part of the metal plate; and a hot forging process of hot forging the heated circular arc part of the metal plate, and simultaneously molding a thick circumferential part and a gear teeth.

Description

TECHNICAL FIELD [0001] The present invention relates to a manufacturing method of a sector gear,

The present disclosure relates to a sector gear used for a reclining mechanism or a height adjusting mechanism of a vehicle seat.

Unless otherwise indicated herein, the description set forth in this identification section is not prior art to the claims of this application and is not to be construed as prior art as described in this identification section.

Generally, the vehicle seat is a reclining mechanism for adjusting the inclination angle of the seat, or a sector gear as a main component of the height adjusting mechanism for adjusting the height of the seat.

The sector gear is not an entire circumference but an arc-shaped gear having a gear angle only in a certain angle range of the circumference, that is, in a circular arc portion. The sector gear includes not only a reclining mechanism or a height adjusting mechanism for a vehicle seat, but also a headrest, a variable armrest, It is widely used in various fields such as steering mechanism.

As an example of a reclining mechanism for a vehicle seat including such a sector gear, Korean Unexamined Patent Publication No. 10-2005-0012383 (published on February 22, 2005) discloses an apparatus for interconnecting an upper bracket and a lower bracket fixed to a seat cushion and a seat back, The upper bracket is rotatably engaged with the lower bracket while the sector gear is integrally formed at the lower end of the upper bracket and the fixed block provided with the lock gear engaged with the sector gear of the upper bracket And is fixed to the lower bracket using a guide block and a cam so as to ascend and descend.

In addition, Korean Patent Registration No. 10-1683397 (published on December 6, 2016) discloses an example of a height adjustment device for a vehicle seat including a sector gear, which includes a base plate, a sector gear rotatably mounted on one side of the base plate, A pinion gear mounted on an output shaft of the pumping device and protruding on the opposite side through a gear hole formed in the base plate to mesh with the sector gear; And a housing bracket covering the sector gear and the pinion gear.

1 is a perspective view of a sector gear used for a reclining mechanism or a height adjusting mechanism of a vehicle seat.

A sector gear used for a reclining mechanism or a height adjusting mechanism of a vehicle seat is formed by a thick portion 120 (see FIG. 1) having a thickness greater than that of the metal plate 110 along an arc formed at one side edge of the metal plate 110 And a gear tooth 130 is formed on the thick portion 120. The gear teeth 130 are formed on the rear surface of the body portion 120,

In the case of a normal gear, it is manufactured through machining that cuts the gear teeth using a hobbing machine, or is manufactured through a multi-step plastic working such as a thermal simplification or cold forging. However, in order to manufacture the sector gear 100, The thick portion 120 must be formed in advance in advance of the machining.

In order to manufacture the sector gear 100 by normal machining, the entire metal plate 110 of the sector gear 100 must be formed to have the same thickness as that of the thick portion 120. In this case, There is a problem that the cost is increased.

In addition, since a multi-step machining process is required to manufacture the sector gear 100 by plastic working, a considerable time is required.

And it is an object of the present invention to provide a method of manufacturing a sector gear that can greatly reduce manufacturing time and cost while maintaining mechanical rigidity.

Further, it is obvious that the present invention is not limited to the technical problems described above, and another technical problem may be derived from the following description.

According to an embodiment of the present disclosure, there is provided a method of manufacturing a metal plate, comprising: a blanking step of cutting a predetermined shape of a metal plate having a circular arc at one side edge thereof from a base metal; a bending process of bending an arc portion of the metal plate; And a hot forging process for simultaneously forming a thick portion and a gear tooth by hot forging the arc portion of the heated metal plate material.

According to a preferred feature of the present disclosure, it is possible to further include a forming step of forming the metal plate after the blanking process.

According to the embodiment of the present disclosure, the basic shape of the sector gear is preliminarily manufactured through machining including blanking and banding on the plate, and then the thick portion and the gear teeth are simultaneously formed by local heating and hot forging, There is an advantage that the time and cost required for manufacturing the sector gear can be greatly reduced while maintaining the mechanical rigidity.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 is a perspective view of a sector gear used for a reclining mechanism or a height adjusting mechanism of a vehicle seat;
2 is a process flow diagram of a method of manufacturing a sector gear according to one embodiment of the present disclosure;
3 is a view of a workpiece subjected to a blanking process in a method of manufacturing a sector gear according to an embodiment of the present disclosure;
FIG. 4 is a view showing a workpiece subjected to a bending process in a method of manufacturing a sector gear according to an embodiment of the present disclosure; FIG.
5 is a view of a workpiece subjected to a localized heating process in a method of manufacturing a sector gear according to an embodiment of the present disclosure;
6 is a view of a sector gear manufactured through a hot forging process in a method of manufacturing a sector gear according to an embodiment of the present disclosure;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration, operation, and effects of a method of manufacturing a sector gear according to a preferred embodiment will be described with reference to the accompanying drawings. For reference, in the following drawings, each component is omitted or schematically shown for convenience and clarity, and the size of each component does not reflect actual size. Like reference numerals refer to like elements throughout the specification, and the same reference numerals will be omitted in the drawings.

FIG. 2 is a process flow diagram of a method of manufacturing a sector gear according to an embodiment of the present disclosure, FIG. 3 is a drawing of a workpiece subjected to a blanking process, FIG. 4 is a drawing of a workpiece subjected to a bending process, Fig. 6 is a view of a sector gear manufactured through a hot forging process. Fig.

2 to 6, a method of manufacturing a sector gear according to an embodiment of the present disclosure includes a step of forming a metal plate 110 having a predetermined shape in which an arcuate portion 111 is formed at one edge of a base material 100, A bending step S2 for bending the arcuate portion 111 of the metal plate 110 and a local heating step for heating the arcuate portion 111 of the bent metal plate 110 And a hot forging step S4 for simultaneously forming the thick portion 120 and the gear teeth 130 by hot forging the arc portion 111 of the heated metal plate 110. [

Here, the blanking step S1 is a kind of sheet metal working process for cutting a metal plate 110 for manufacturing a sector gear from a base material 100 such as a steel plate having a predetermined thickness.

In the blanking step S1, as shown in detail in FIG. 3, a metal plate material 110 having a predetermined shape and having an arcuate portion 111 formed on one side edge of the base material 100 is cut using a die and a punch, I will. At this time, it is preferable that the through holes 113 for shaft coupling of the sector gear are cut out at the same time.

The term " blanking " used in the blanking step S1 includes the meaning such as punching or press cutting as well as ordinary blanking.

According to the embodiment, the forming step S1-1 for forming the metal plate 110 after the blanking step S1 may be further performed. The foaming step (S1-1) is a step of plastically deforming the metal plate 100 into a plurality of planar shapes to increase the rigidity of the metal plate 110, and can be performed by a conventional press machine, a roll forming machine, or the like.

After the blanking step (S1), the bending step (S2) is performed. The bending process S2 is a process of bending the arcuate portion 111 of the metal plate 110 that has undergone the blanking process S1.

In the bending step S2, as shown in Fig. 4, the arcuate portion 111 is vertically bent along a virtual imaginary concentric circle arc among the metal plate members 110 in the form of a steel plate. At this time, the arcuate portion 111 of the metal plate 110 is bent to a height of 4 to 6 times the thickness of the metal plate 110. For example, when the thickness of the metal plate 110 is 3.5 mm, the height of the portion bent by the bending process S2 is preferably 18.5 mm from the bottom of the metal plate 110. In the bending step (S2), a conventional banding machine is applied for bending the arc part (111).

The term 'bending' used in the above-described bending process S2 includes not only conventional bending but also meaning such as polding, rolling and pressing.

After the bending step (S2), the local heating step (S3) is performed. The local heating step S3 is a process of locally heating only the arcuate portion 111 bent in the metal sheet 110 that has undergone the bending process S2 for the subsequent hot forging, not the entire metal plate 110. [

In the local heating step (S3), it is preferable to inductively heat the bent circular arc part (111) of the metal plate to a high temperature of 900 to 1250 DEG C by using a high frequency induction heater including a coil However, it is apparent that various known heating methods and heating devices are applicable if only the bent circular arc portion 111 of the metal plate can be locally heated.

The metal plate 110 having been subjected to the local heating step S3 is heated only by the portion of the circular arc portion 111 bent as shown in FIG.

After the above-described local heating step (S3), a hot forging step (S4) is performed. The hot forging step S4 is a step of finally manufacturing a sector gear by simultaneously forming the thick portion 120 and the gear teeth 130 by forging the arc portion 111 of the heated metal plate 110. [

In the hot forging step S4, the metal plate 110 subjected to the local heating step S3 is subjected to hot forging by heating the arc part 111 heated by the local heating step S3 to the hot forging metal mold including the upper and lower molds As shown in FIG. 6, the thick portion 120 and the gear teeth 130 are formed simultaneously. At this time, the thick portion 120 formed by the hot forging step S4 preferably has a height and a width corresponding to twice the thickness of the metal plate 110. Accordingly, the depth of the valley portion of the gear teeth 130 can be formed to the thickness of the metal plate 110.

The structure of the hot forging mold applied in the hot forging step S4 is the same as that of the known hot forging mold only in the shape of the upper and lower molds, so that detailed description thereof will be omitted for the sake of simplification of the description .

According to the embodiment, the sector gear manufactured through the above-described hot forging step (S4) may be further subjected to a heat treatment step for heat treatment for increasing the rigidity, and the sector gear manufactured through the hot forging step (S4) , A ceramic coating, a deposition, a grinding, or the like may be additionally performed.

In the method of manufacturing the sector gear according to the embodiment of the present disclosure as described above, the metal plate 110 is machined in the basic shape of the sector gear including the arc-shaped edge through the machining including the blanking and the bending The thick portion 120 and the gear teeth 130 are simultaneously formed on the edge of the circular arc shape by local heating and hot forging so that the time required for manufacturing the sector gear while maintaining the mechanical rigidity of the sector gear The cost can be greatly reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. It is to be understood that various equivalents and modifications may be substituted for those at the time of the present application. It is to be understood, therefore, that the above description is intended to be illustrative, and not restrictive, and that the scope of the present invention will be defined by the appended claims rather than by the foregoing description, All changes or modifications that come within the scope of the equivalent concept are to be construed as being included within the scope of the present invention.

S1: blanking process
S1-1: Foaming process
S2: Banding process
S3: Local heating process
S4: Hot forging process
100: base metal
110: metal plate
111:
113: Through hole
120: thickening
130: gear teeth

Claims (5)

A blanking process for cutting a metal plate having a predetermined shape in which an arc portion is formed at one side edge from the base material;
A bending step of bending an arcuate portion of the metal plate material;
A local heating step of heating the arc portion of the bent metal plate; And
And a hot forging step of simultaneously forming a thick portion and a gear tooth by hot forging the circular arc portion of the heated metal plate material.
The method according to claim 1,
Further comprising a forming step of forming the metal plate after the blanking step.
The method according to claim 1 or 2,
Wherein the bending step bends the arcuate portion of the metal plate vertically and bends the metal plate at a height of 4 to 6 times the thickness of the metal plate.
The method according to claim 1 or 2,
Wherein in the local heating step, the arc portion of the metal plate is induction heated to 900 to 1250 占 폚 by using a high frequency induction heater including a coil.
The method according to claim 1 or 2,
Wherein the thick portion formed by the hot forging process has a height and a width corresponding to twice the thickness of the metal plate.

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