KR20220019310A - A manufacturing method for input shaft - Google Patents

Abstract

The present invention relates to a manufacturing method of an input shaft comprising the following steps of: manufacturing a second metal pipe by cold shafting a first metal pipe; and manufacturing an input shaft by machining the second metal pipe. Because the second metal pipe is manufactured by cold shafting the first metal pipe and then the input shaft, which is a final product, is manufactured by machining the second metal pipe, the input shaft is provided with minimized insertion amount of raw material, minimized machining, and reduced processing cost.

Description

A manufacturing method of an input shaft {A MANUFACTURING METHOD FOR INPUT SHAFT}

The present invention relates to a method of manufacturing an input shaft, and more particularly, to a method of manufacturing an input shaft capable of reducing process costs by minimizing the input amount of raw materials and minimizing machining.

This patent is a patent invented through the 'Technology development package support for core parts development and demonstration support project for future automobiles in the industrial crisis area in 2020' hosted by Gyeongnam Technopark.

In general, a steering device is a device operated when the driving direction of a vehicle is arbitrarily changed according to the intention of the driver. This allows you to control the direction of progress.

The automobile steering system may be largely divided into an electric power assisted steering system and a hydraulic power assisted steering system.

The electric power assist steering system adjusts the steering force of the steering wheel according to the driving speed of the vehicle. It is a kind of steering system provided to

On the other hand, the hydraulic power assist steering system uses the driving force of the engine to drive the power steering pump, and selectively injects the power steering oil output from the power steering pump into the cylinder to lighten the steering force at the time of stopping or at low speed, and at high speed It is a steering system that provides high-speed driving stability to the driver by increasing the steering force.

1 is a view showing the main part of a conventional hydraulic power assisted steering system.

Referring to FIG. 1 , the gearbox 11 of the conventional hydraulic power assist steering device has a configuration that converts the rotational motion of the pinion gear 12 into the linear motion of the rack bar 13, and the input shaft 10 One side is connected to the universal joint 20 in a hollow shape.

In addition, one side of the torsion bar 14 is inserted and fixed into the hollow inside of the input shaft 10 and interlocked with the input shaft 10 connected to the universal joint 20, and the other side is connected to the pinion shaft 15, The pinion shaft 15 forms a pinion gear 12 meshed with the rack bar 13 .

According to this configuration, when the driver rotates the steering wheel, the input shaft 10 , the torsion bar 14 , the pinion shaft 15 , and the pinion gear 12 are rotated and driven in association with each other.

The torsion bar 14 is a kind of spring that generates torsion caused by a rotation difference between the universal joint 20 and the pinion shaft 15, and changes the flow path of the control valve housing 16 by twisting the torsion bar 14. have a function

In addition, the outer circumferential surface of the input shaft 10 is surrounded by a hollow valve body 17 that rotates in conjunction with the pinion shaft 15, and a control installed to surround the outer circumference of the valve body 17 A supply passage 16a, a recovery passage 16b, a left passage 16c, and a right passage 16d are formed in the valve housing 16 .

At this time, when the driver does not operate the steering device, the power steering oil that has entered through the supply passage 16a is returned to the recovery passage 16b through the plurality of return holes 18 formed in the input shaft 10 .

On the other hand, such a conventional input shaft prepares a round bar material, drills an oil hole in the center of the round bar material, forms an oil hole communicating with the oil hole on the outer periphery of the round bar, and finally the round bar It consists of a process of removing the burr generated while drilling the oil hole on the inner circumferential surface.

As a related technology, Korean Patent Laid-Open No. 10-2015-0093942 is disclosed. Here, the material preparation process of preparing the round bar material, the process of forming mandrel holes by drilling or piercing on both sides of the round bar material, and the swaging process of putting mandrels on both sides of the round bar material and passing dies through both sides are performed. Input for automobile transmission comprising a swaging process of forming a long shaft and a short shaft on both sides with a flange, and a process of forming splines and forming oil holes by pressing a spline forming die on the long and short shafts formed on both sides A shaft manufacturing method (hereinafter referred to as "input shaft manufacturing method") is provided.

However, in the case of such a conventional input shaft, as described above, since the round bar material is machined to match the product shape, the cost is excessive depending on the input amount of the raw material and the consumption of the processing tool, and the economic loss is large. There is a problem in that the process cost increases due to a decrease in productivity due to a long processing time.

Republic of Korea Patent Publication No. 10-2015-0093942

An object of the present invention is to provide a method of manufacturing an input shaft capable of reducing process costs by minimizing the input amount of raw materials and minimizing machining.

Objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above-mentioned problems, the present invention comprises the steps of: manufacturing a second metal tube by cold-shaping the first metal tube; and manufacturing the input shaft by machining the second metal tube.

In addition, the present invention comprises the steps of preparing a metal billet; and extruding the metal billet to manufacture the first metal tube.

In addition, the present invention provides a method of manufacturing an input shaft in which the manufacturing of the first metal tube by extruding the metal billet is extruding the metal billet by direct extrusion.

In addition, in the present invention, the manufacturing of the second metal tube by cold axial pipe of the first metal pipe is a process of cold axial pipe by a cold extrusion process, and when performing the cold extrusion process, the inner diameter and outer diameter of the first metal tube, Provided is a method of manufacturing an input shaft, characterized in that the lubricating oil is supplied by a lubricating oil supply device.

In addition, the present invention provides an input shaft manufactured by the method for manufacturing the input shaft.

According to the present invention as described above, a second metal tube is manufactured by cold-shaping the first metal tube, and then, the input shaft, which is a final product, is manufactured by machining the second metal tube, so that the input amount of raw materials is minimized and , it is possible to provide an input shaft capable of reducing process costs by minimizing machining.

In addition, in the present invention, by cold-shafting the first metal tube, the surface roughness of the processed surface is improved compared to the case of performing forging, and the process proceeds quickly to improve product production efficiency, and the dimensional error range of the finished product It is possible to provide an input shaft that can be reduced.

1 is a view showing the main part of a conventional hydraulic power assisted steering system.
2 is a schematic diagram illustrating a method of manufacturing an input shaft according to the present invention, and FIG. 3 is a flowchart illustrating a method of manufacturing an input shaft according to the present invention.
Figure 4 is a perspective view showing the input shaft according to the present invention, Figure 5 is a side view showing the input shaft according to the present invention, Figure 6 is a cross-sectional view showing the input shaft according to the present invention.
7 is a schematic cross-sectional view for explaining that the metal tube is cold-shafted.
8 is a schematic diagram showing the structure of a cold extrusion apparatus and an outer diameter die according to a first embodiment of the present invention, and FIG. 9 is an outer diameter die holder to which a lubricant supply port according to a second embodiment of the present invention is applied; It is a schematic diagram showing the structure of a cold extrusion apparatus equipped with an inner diameter plug to which a lubricant supply hole is applied.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

With reference to the accompanying drawings will be described in detail for the implementation of the present invention. Irrespective of the drawings, like reference numbers refer to like elements, and "and/or" includes each and every combination of one or more of the recited items.

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between a component and other components. Spatially relative terms should be understood as terms including different directions of components during use or operation in addition to the directions shown in the drawings. For example, when a component shown in the drawing is turned over, a component described as “beneath” or “beneath” of another component may be placed “above” of the other component. can Accordingly, the exemplary term “below” may include both directions below and above. Components may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

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

2 is a schematic diagram illustrating a method of manufacturing an input shaft according to the present invention, and FIG. 3 is a flowchart illustrating a method of manufacturing an input shaft according to the present invention.

2 and 3 , first, the method of manufacturing an input shaft according to the present invention includes preparing a metal billet 210 (S110).

The metal billet may be made of at least one material selected from the group consisting of Fe, Ag, Cu, Al, Mg and Ti, but the material of the metal billet is not limited in the present invention.

Next, the method of manufacturing the input shaft according to the present invention includes the step of manufacturing the first metal tube 220 by extruding the metal billet 110 (S120).

To manufacture the first metal tube 220 by extruding the metal billet, the metal billet is manufactured, and the metal billet is introduced into the extruder by, for example, direct extrusion, a predetermined product shape, That is, it can be manufactured with the first metal tube.

In this case, the direct extrusion method refers to a method of extruding through a die positioned opposite to the ram by inserting the billet into the container and pressing it with a ram.

However, the method of manufacturing the metal billet 210 as the first metal tube 220 is not limited in the present invention, and the first metal tube 220 may be manufactured by various known methods.

On the other hand, the first metal tube 220 corresponds to a raw material in the method for manufacturing an input shaft according to the present invention. Therefore, in the present invention, the first metal tube 220 is used as a raw material, and the input according to the present invention Shafts can be manufactured.

At this time, the first metal tube 220 includes a first metal tube body portion 221 and a first hollow portion 222 located inside the first metal tube body portion 221. Therefore, in the present invention, A structure including the first hollow part 222 inside the first metal tube body part 221 may be defined as the first metal tube 220 .

Next, the method of manufacturing the input shaft according to the present invention includes the step of manufacturing the second metal tube 230 by cold-shaping the first metal tube 220 (S130).

The manufacturing of the second metal pipe by cold shaving the first metal pipe may be manufactured through the following cold extrusion method, however, the method of cold shaving the first metal pipe in the present invention is not limited thereto.

Hereinafter, the cold shaft pipe process through the cold extrusion device will be described in more detail.

7 is a schematic cross-sectional view for explaining that the metal tube is cold-shafted.

Referring to FIG. 7 , the thickness of the metal tube may be reduced while the outer diameter of the tube at a predetermined position is reduced by the cold shaft tube process through the cold extrusion device.

More specifically, the reduction in the thickness of the metal tube 10 means making the thickness of the metal tube 10 itself as thin as the difference between T1 and T2 before and after cold extrusion processing, and the axial tube processing is the outer diameter size and inner diameter of the metal tube 10 . It means reducing the size by the difference between D1 and D2 and the difference between D3 and D4, respectively, and this reduction in thickness can reduce the weight per unit length of the metal tube.

Therefore, the cold shaft pipe of the metal pipe can be divided into a reduced thickness and a shaft pipe.

8 is a schematic diagram showing the structure of a cold extrusion apparatus and an outer diameter die according to a first embodiment of the present invention, and FIG. 9 is an outer diameter die holder to which a lubricant supply port according to a second embodiment of the present invention is applied; It is a schematic diagram showing the structure of a cold extrusion apparatus equipped with an inner diameter plug to which a lubricant supply hole is applied.

First, referring to FIG. 8 , in the cold extrusion apparatus according to the first embodiment of the present invention, a stopper for fixing one end of a pre-fabricated metal pipe (metal pipe) 10 to one side of the cold extrusion apparatus 100 . 110 is mounted, a vice 120 for fixing the central portion of the metal tube 10 is mounted on the side of the stopper 110, and the opposite end of the metal tube 10 is inserted on the side of the vice 120 The outer diameter die holder 130 is mounted.

In addition, a pipe hole 131 is formed inside the outer diameter die holder 130 so that the end of the cold-extruded metal tube 10 can be inserted into the pipe hole 131 , and the outer diameter die holder 130 inside In the pipe hole 131, an outer diameter die 150 is mounted in the inlet direction, and an inclined surface 151 is formed inside the outer diameter die 150, and one end of the metal tube 10 is fixed to the stopper 110. It is fitted so that the outer diameter of the end is in contact with the inclined surface (151).

In addition, a rod 140 is connected to the outer diameter die holder 130 , and one end of the inner diameter plug 160 is connected to the coupling part of the outer diameter die holder 130 and the rod 140 in a fixed state. Through the hole 131, the opposite end is mounted to be located in the inner center of the outer diameter die 150, and the end of the inner diameter plug 160 is inserted into the inner diameter of the metal tube 10 to be cold extruded, and the rod 140 A pressure cylinder 170 is connected to the pressure cylinder 170, and various means for generating a linear reciprocating motion, such as an air cylinder or a hydraulic cylinder, may be applied, and it is preferable to apply a hydraulic cylinder among them.

On the other hand, the pressure cylinder 170 may be equipped with a linear sensor 171 that measures the amount of movement of the pressure cylinder 170 to adjust the extrusion length of the metal tube 10 .

Next, referring to FIG. 9 , the cold extrusion apparatus according to the second embodiment of the present invention is mostly the same as the cold extrusion apparatus of the first embodiment described above, except that the cold extrusion apparatus according to the second embodiment of the present invention At least one lubricant supply hole 152 is formed in the outer diameter die holder 130, and the lubricant oil supply hole 152 is a lubricant supply hole formed in the inner center of the outer diameter die 150 and the inner diameter plug 160 ( 161) and lubricating oil is supplied from a lubricating oil supply device 190 (not shown) connected to the lubricating oil supply port 152 so that the lubricating oil can be applied to the inner and outer diameters of the metal tube 10 during the cold extrusion process. can do.

That is, in the case of the second embodiment of the present invention, as compared to the first embodiment, at least one lubricant supply port 152 is included in the outer diameter die holder 130, and the metal tube 10 in the cold extrusion process. Lubricating oil may be applied to the inner and outer diameters of

The operation of such a cold extrusion device is, first, by operating the pressure cylinder 170 to move the outer diameter die 150 backward, and then attach both ends of the metal tube 10 to the stopper 110 and the inclined surface of the outer diameter die 150, respectively. (151), when the end of the metal tube 10 is positioned on the inclined surface 151, the inner diameter plug 160 is inserted into the inner diameter of the metal tube 10, so that the pipe 10 is inserted into the cold extrusion apparatus 100. will settle down

Next, when the seating of the metal tube 10 is completed, the vise 120 is operated to fix the central part of the metal tube 10 (S20), and when the fixing of the metal tube 10 is completed, the pressurizing cylinder 170 is operated to pressurize The extrusion process is performed by advancing the outer diameter die 150 and the inner diameter plug 160 through the rod 140 connected to the cylinder 170, and the inclined surface 151 of the outer diameter die 150 and the inner diameter of the metal tube 10 By the inserted inner diameter plug 160, extrusion processing occurs simultaneously in the inner diameter as well as the outer diameter of the metal tube 10, so that the thickness of one end of the metal tube 10 is reduced and the shaft tube processing is possible at the same time.

At this time, in the process of fixing the metal tube 10 with the vise 120 , two or more visees 120 may be arranged in parallel to fix the metal tube 10 . ), it is possible to prevent the central portion of the metal tube 10 from being bent by the compressive force generated during the cold extrusion process, thereby improving the shape and dimensional accuracy of the produced product.

Next, when the thickness reduction and shaft pipe processing of the metal tube 10 in one direction are completed, the pressure cylinder 170 is operated to reverse the outer diameter die 150 and the inner diameter plug 160, and the vise 120 is operated to operate the metal tube ( After removing the fixing of 10), the metal tube 10 is reversed, and the opposite side of the metal tube 10 is also subjected to cold extrusion through the same process as the above-described process by changing the direction of the metal tube 10 to the metal tube 10 The reduction of the thickness of both ends and the processing of the shaft pipe are completed.

When the thickness of the end of the metal pipe 10 is reduced and the shaft pipe processing is performed through cold extrusion as above, the surface roughness of the processing surface can be improved compared to the case of performing the forging processing, and the process proceeds faster than the forging processing, so that the product Production efficiency can be improved, and the dimensional error range of the finished product can be reduced compared to forging processing.

In addition, cold working has superior dimensional precision of the processed part compared to hot working, so that the shape defect rate of the product can be further lowered. To increase the space utilization of production facilities.

On the other hand, in relation to the second embodiment, when performing cold extrusion processing, the outer diameter die ( 150) and by supplying lubricating oil to the inner diameter plug 160, friction generated between the inclined surface 151 of the outer diameter die 150 and the outer diameter of the metal tube 10, and between the inner diameter of the inner diameter plug 160 and the metal tube 10 By reducing the friction generated in the metal tube 10, cold extrusion processing of the outer diameter and inner diameter of the metal tube 10 can be made more smoothly.

Through this process, in the present invention, the first metal tube 220 may be cold-shrinkled to manufacture the first metal tube 230, however, in the present invention, limiting the method of cold-shaping the first metal tube 220 is limited. not.

Continuingly, referring to FIGS. 2 and 3 , the second metal tube 230 is formed by cold-shaping the first metal tube, and the second metal tube 230 includes a second metal tube body 231 and the second metal tube. and a second hollow part 232 positioned inside the metal tube body 231, and thus, in the present invention, the second hollow part 232 is included in the second metal tube body 231. A structure to be used may be defined as the second metal tube 230 .

At this time, as described above, the second metal tube body portion 231 has the outer diameter of the tube at a certain position reduced and the thickness of the metal tube reduced by the cold shaft tube process as described above. body portion (231a); and a second metal tube second body portion 231b disposed continuously with the second metal tube first body portion 231a and having a second outer diameter.

Meanwhile, the first outer diameter and the second outer diameter are smaller than the outer diameter of the first metal tube body 221 , and the values of the first outer diameter and the second outer diameter are not limited in the present invention.

Next, the method of manufacturing the input shaft according to the present invention includes the step of manufacturing the input shaft 240 by machining the second metal tube 230 (S140).

The machining of the second metal tube is to process the second metal tube into an input shaft as a final product, and by processing the second metal tube by a general machining apparatus, an input shaft as a final product according to the present invention can be manufactured. can

For example, the display area in (d) of FIG. 3 corresponds to a machined area, but the machining area is not limited in the present invention.

Through this process, the input shaft can be manufactured in the present invention.

Figure 4 is a perspective view showing the input shaft according to the present invention, Figure 5 is a side view showing the input shaft according to the present invention, Figure 6 is a cross-sectional view showing the input shaft according to the present invention.

4 to 6, the input shaft 240 according to the present invention includes a shaft body portion 241; and a shaft hollow part 242 positioned inside the shaft body part 241 .

At this time, the shaft body portion 241, the shaft first body portion (241a) of a first outer diameter; and a shaft second body part 241b of a second outer diameter and disposed continuously with the shaft first body part 241a, wherein the shaft body part 241 is a cold shaft pipe process at a predetermined position. It is manufactured by machining the second metal tube body 231 of which the thickness of the metal tube is reduced at the same time as the outer diameter of the tube is reduced, and the numerical values of the first outer diameter and the second outer diameter are not limited in the present invention.

At this time, one end 243 of the shaft body is connected to the universal joint 20 of FIG. 1 described above, and the other end 244 of the shaft body is the pinion shaft of the gearbox 11 of FIG. 1 described above. (15) is connected.

At this time, on the outer circumferential surface of the one end 243 of the shaft body, machining surfaces a1 and a2 that are symmetrical to each other are formed, respectively, and based on the machining surfaces a1 and a2, , the other end 244 of the shaft body portion may have a coupling portion 245 formed in a non-circular cross-sectional shape.

That is, as shown in FIGS. 4 to 6 , on the outer periphery of the one end 243 of the shaft body, the processing surfaces a1 and a2 are respectively formed in different shapes, and the other end of the pulling-up shaft body part ( A coupling portion 245 having a polygonal cross-sectional structure is machined and formed on the 244 , based on the machining surfaces a1 and a2 .

As described above, in the present invention, the second metal tube 230 can be machined to be processed into an input shaft as a final product, and this machining process is performed by the machining surfaces a1 and a2 and the coupling part ( 245) can be understood as a process of processing, etc.

As described above, in the case of the conventional input shaft, since the round bar material is machined to match the product shape, the cost is excessive depending on the input amount of the raw material and the consumption of the processing tool, the economical loss is large and the processing time is shortened. There is a problem in that the process cost increases due to the decrease in productivity.

However, in the present invention, since a second metal tube is manufactured by cold-shaping the first metal tube, and then the second metal tube is machined to manufacture an input shaft as a final product, the input amount of raw materials is minimized, and machining By minimizing , it is possible to provide an input shaft capable of reducing process costs.

In addition, in the present invention, by cold-shafting the first metal tube, the surface roughness of the processed surface is improved compared to the case of performing forging, and the process proceeds quickly to improve product production efficiency, and the dimensional error range of the finished product It is possible to provide an input shaft that can be reduced.

Although embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can practice the present invention in other specific forms without changing its technical spirit or essential features. You will understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (5)

manufacturing a second metal tube by cold accumulating the first metal tube; and
Method of manufacturing an input shaft comprising the step of manufacturing the input shaft by machining the second metal tube. The method of claim 1,
preparing a metal billet; and
The method of manufacturing an input shaft further comprising the step of extruding the metal billet to manufacture the first metal tube. 3. The method of claim 2,
Manufacturing the first metal tube by extruding the metal billet is a method of manufacturing an input shaft by extruding the metal billet by direct extrusion. The method of claim 1,
Manufacturing the second metal tube by cold-shaping the first metal tube is a process of cold-shaping by a cold extrusion process,
When performing the cold extrusion processing, the method of manufacturing an input shaft, characterized in that the supply of lubricating oil to the inner diameter and outer diameter of the first metal tube by a lubricating oil supply device. An input shaft manufactured by the method for manufacturing an input shaft according to any one of claims 1 to 4.

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