KR101247798B1 - Apparatus for manufacturing yoke used steering shaft system - Google Patents

Abstract

The present invention relates to a yoke manufacturing apparatus for an automobile steering shaft for manufacturing a yoke of an aluminum material through a single forging process, thereby reducing the unit cost of the product, increasing the production efficiency, and producing a light weight and high strength product.
To this end, the apparatus for inserting the forging material into the die formed in the extrusion groove to produce a yoke used in the steering shaft of the vehicle by extrusion punching, comprising: a clamp installed at the top of the punch; A spring unit inserted into the punch and installed in an elastic state at the lower end of the clamp; A punch guide slidably fitted to the punch and installed at a lower end of the spring unit to press a portion of the forged material to be extruded backward in the die; The clamp, the spring unit, and the cover is installed outside the punch guide, characterized in that it comprises a punch housing for preventing the separation of the punch guide by the separation preventing means.
According to the above configuration, the forging material inside the die is extruded back and forth by one press action to manufacture the yoke of the aluminum material, thereby simplifying the number of processes, reducing the production cost of the product, improving the product productivity, and improving the yoke. It is possible to produce at light weight, but also to improve the strength of the product.

Description

Apparatus for manufacturing yoke used steering shaft system}

The present invention relates to a yoke manufacturing apparatus for a steering shaft, and more particularly, to manufacture a yoke of aluminum material through a single forging process, to reduce the unit cost of the product, increase the production efficiency, and to produce a product of light weight and high strength. And a yoke manufacturing apparatus for a vehicle steering shaft.

Plastic processing, in particular forging, is a processing method for forming products of desired shape while minimizing the loss of materials, and it is possible to mass-produce basic core parts of the automobile, ship, and aircraft industries, and the scope of application thereof is gradually expanding.

In particular, the plastic processing industry is an optimal process for producing high-quality, high-quality parts that can be upgraded in product quality and difficult to substitute for other manufacturing processes. Recently, existing processes have been advanced and combined with processing technology and new technologies. Technology development and practical use are rapidly spreading in accordance with the trend of high-function and high value-added products.

Such forging may be classified into hot forging, warm forging, cold forging, etc. according to the manufacturing method, manufacturing equipment, and molding temperature.

Among them, hot forging is mainly applied when a large deformation amount is required due to the advantages of improving metal fluidity and giving a large deformation with a small force to form easily by forming a material at a temperature above the recrystallization temperature. It is mainly used for the pre-processing or production of large products.

However, hot forging is a typical industry in the 3D industry, which causes dust and harmful gases due to the heating of the material, causing environmental pollution and noise pollution, and reducing the utilization rate of the material due to excessive scrap generation. It is being replaced by a cold forging process that is more environmentally friendly, lowers costs, and creates high added value of the product.

Cold forging has the advantage of being able to perform Net Shape molding, which has high dimensional accuracy, greatly improves material utilization rate, and eliminates and reduces post-cutting processing to realize resource and energy saving. In addition, since it is possible to suppress the occurrence of environmentally harmful elements due to heating of materials, and it is possible to produce high-precision parts in the case of automobile parts in an environmentally friendly process, production of various kinds of small quantities is mainly made.

On the other hand, among the major parts of the MDPS (motor steering system), such as the column and the intum shaft is long, complex, high precision, it is very difficult to form, but it is directly connected to the safety of life in the event of an accident, requires precision and rigidity in manufacturing.

Thus, when looking at the torsion joint yoke, one of the main components of the steering column, the yoke is first manufactured by bending and welding the hot rolled steel sheet, and a ring having a square shape formed therein to transmit the rotational force of the yoke to the shaft. Fit inside the yoke. At this time, when the yoke is bent, since the exact roundness does not come out, the resin is filled in the space between the shaft and the yoke to increase the surface pressure so that the shaft and the yoke do not turn away.

However, as described above, since the yoke is welded by bending a sheet material, only one product can be processed in one cycle, which leads to a problem in that the productivity is greatly reduced. In addition, the weld is weak during the torsional movement of the yoke. There is also a big problem that is likely to occur.

In addition, the production of the product through a number of parts joining work in addition to the above welding work, there is a problem that the production cost of the product decreases as well as the cost of the product rises, and also because the yoke is manufactured using a heavy hot-rolled steel sheet, insufficient fuel economy Due to this, there is a problem that the competitiveness of the product falls.

On the other hand, Figure 1 shows a steering yoke (Steering Yoke) manufactured by forging to solve some of the above problems, look at the configuration yoke portion connected to the universal joint 21 connected to the steering gear side And a serration section 25 for connecting to the shaft section 23 and the steering wheel (not shown).

For this configuration, the yoke portion 22, which is the head portion, is forged, and the shaft portion 23 forms the serration portions 25 and 27 on both sides after machining the long bar. The serration portion 27 of the c) is fitted to the serration 27a formed on the yoke portion 22, and then welded, or as shown, the incision 26 and the serration 27a are formed to form the shaft portion ( After fitting the serration part 27 of 23, the bolt 28 is assembled and assembled.

In addition, FIG. 2 illustrates another conventional technique of manufacturing a yoke for a steering shaft by applying cold forging, and inserts a material for cold forging into the die 1 and presses the material with the punch 2. To produce a yoke. That is, by pressing through the punch 2, the raw material is simultaneously extruded back and forth in the extrusion groove formed inside the die 1, so that the yoke can be manufactured.

However, in the above-described prior art shown in FIGS. 1 and 2, the filling of the material is completed in the cavity of the upper die where the back extrusion is performed due to the process characteristics in which the front extrusion and the back extrusion are simultaneously performed during the forging of the yoke. There was a problem that the material is not completely filled in the cavity portion of the lower die in which the forward extrusion is made.

3 and 4 is another yoke manufacturing technique for solving the problems as described above, forging a material forging into the die 10, the material as a front extrusion punch 11 as shown in FIG. The pressure is gradually filled to fill the extrusion grooves formed in the inner bottom of the die 10. Thereafter, as shown in FIG. 4, the material is secondarily pressurized by the back extrusion punch 16 to fill the material in the extrusion groove formed in the upper portion of the die 15, thereby manufacturing a yoke.

In addition, Figures 5 to 7 relates to the "manufacture method of the steering yoke for steering device of the vehicle" of the Republic of Korea Patent Publication No. 2000-0058458 published and filed by the applicant, the front extrusion of the shaft of the steering yoke It forms by a process and a yoke part is formed by a back extrusion process.

That is, the shaft portion 2 is forward-extruded through the first mold having the extrusion hole equal to the diameter of the shaft portion 2, leaving only the head portion where the yoke portion 3 is to be formed from the raw material after the pretreatment process.

It has an insertion hole 12 to allow insertion of the shaft portion 2, and extends in a state expanded from the insertion hole 12, and has a size and shape that can accommodate the outer surface of the yoke portion 3 in close contact. The center portion of the head portion 10 to process the head portion 10 of the raw material into the shape of the yoke portion 3 by cold plastic deformation through the second mold 11 having the yoke portion forming hole 13. Is pressed with a punch die 14, and the yoke part 3 is extruded backward in a fork shape.

However, the above-described conventional manufacturing method of the steering yoke is forging the both ends of the yoke during the yoke production in the first and second, two times, thereby increasing the number of processes and the addition of a mold, which is the cost and production cost of the product There was a problem that the price competitiveness of the product was falling.

In addition, the yoke manufactured through the conventional forging process, as well as the majority of the parts used in the steering shaft is still formed of a general steel or hot rolled steel sheet material, there is a problem that the product weight is increased and the competitiveness is lowered.

Korean Laid-Open Patent Publication No. 2000-0058458

The present invention has been made to solve the conventional problems as described above, by manufacturing the yoke of aluminum material through one forging process to reduce the unit cost of the yoke product, increase the production efficiency, lightweight and high-strength product It is to provide a yoke manufacturing apparatus for an automobile steering shaft that can be produced.

In the configuration of the present invention for achieving the above object, in the apparatus for injecting the forging material into a die formed in the extrusion groove formed in the extrusion groove to produce a yoke used in the steering shaft of the vehicle, the punch top, A clamp installed in the; A spring unit inserted into the punch and installed in an elastic state at the lower end of the clamp; A punch guide slidably fitted to the punch and installed at a lower end of the spring unit to press a portion of the forged material to be extruded backward in the die; The clamp, the spring unit, and the cover is installed outside the punch guide, characterized in that it comprises a punch housing for preventing the separation of the punch guide by the separation preventing means.

Here, the spring unit, the coil spring is installed in the elastic state between the clamp and the punch guide sandwiched on the outside of the punch; It is configured to include a plurality of dish springs sandwiched between the coil spring and the clamp guide and the punch guide.

The release preventing means is formed by forming a stopper around the upper periphery of the upper end of the punch guide, and forming a stopper to hang the release stopper around the inner periphery of the bottom of the punch housing.

In addition, the forged material uses an aluminum material.

The present invention through the above-mentioned problem solving means, by forging the forging material introduced into the die at the same time by a single pressing action to produce the yoke by simultaneously, thereby simplifying the number of processes, no additional mold yoke In addition to reducing the production cost and unit cost of the product, there is an effect that can improve the productivity of the product.

In addition, by cold forging the yoke using the aluminum material of AISI 6061 as a forging material, and by heat-treating the manufactured yoke, it is possible to produce a yoke at a light weight, but can produce a product of high strength and high precision to weight. .

1 is an exploded perspective view showing a structure of a steering yoke according to the prior art;
Figure 2 is a process diagram schematically showing a yoke manufacturing process for simultaneously molding the front and rear extrusion by the forging process according to another prior art,
Figure 3 is a process diagram schematically showing a process of molding the first forward extrusion by the forging process according to another prior art,
FIG. 4 is a process diagram schematically illustrating a process of secondary extrusion of a molded material molded in FIG. 3;
5 is a cross-sectional view showing the shaft forming process of the steering yoke by another prior art extrusion process;
FIG. 6 is a cross-sectional view illustrating a yoke portion forming process of a steering yoke by back extruding the material formed in FIG. 5;
7 is a plan view showing a planar shape of a mold for forming the yoke portion of FIG. 6;
8 is a cross-sectional view showing the overall structure of the yoke manufacturing apparatus for steering shaft according to the present invention;
9 is a cross-sectional view of the forging process in which the punch guide is stopped in the yoke manufacturing apparatus shown in FIG. 8;
10 is a cross-sectional view of the forging process is completed in the yoke manufacturing apparatus shown in FIG.
11 is a (a) front cross-sectional view and (b) side view of the yoke manufactured by the yoke manufacturing apparatus according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

8 to 11 illustrate a yoke manufacturing apparatus for an automobile steering shaft of the present invention, wherein a clamp 120 and a spring are provided in a forging manufacturing apparatus provided with upper and lower rams, a punch 110, a die 170, and the like. The unit includes a punch guide 150 and a punch housing 160.

Looking briefly about the forging manufacturing apparatus through Figure 8, the upper ram 100 that can be pressed by a high pressure force on the upper end, and press the forging material to the upper ram 100 can be extruded process. The fixed punch (110). Here, the forging material used in the present invention uses the aluminum material of AISI 6061, and the final material of the yoke is applied to AISI 6061-T6 by solution heat treatment of the forged yoke.

And, directly below the upper ram 100 is provided with a die 170 that can be provided with a forging material built-in. Here, an extrusion groove 172 is engraved on the inner circumferential surface of the die 170 to conform to the outer shape of the product to be forged, and a separate insert member is formed in the die 170 to match the shape of the product to be molded. I can attach it more fixedly.

In addition, the anvil 180 is fixedly installed at the lower portion of the die 170, and the core 182 which can be elevated up and down by a lower ram may be installed at the center of the anvil 180.

8 to 10, the clamp 120 is formed to be stepped around the upper end of the punch 110 in a stepped manner, and the upper surface of the spring unit is elastically connected to the bottom of the stepped clamp 120. It is provided in a state, the spring unit is provided in the form fitted to the outside of the punch (110).

In addition, the lower end of the spring unit is provided with a stepped punch guide 150 stepped, and the stepped punch guide 150 is provided with a lower surface of the spring unit is connected to the elastic support. Here, the punch guide 150 is provided to be slidably fitted to the outer peripheral surface of the punch 110, it is configured to press the upper portion of the forging material to be extruded back in the die 170.

At this time, the punch guide 150 is involved in the extrusion of the forging material while moving downward with the punch 110, but when the punch guide 150 moves downward by a predetermined section to press the forging material, As the upward pressure of the forging material to be extruded backward at a predetermined point and the elastic lowering pressure of the spring unit to push the punch guide 150 downward are offset each other, the punch guide 150 is configured to stop without lowering any more.

In addition, a portion of the punch guide 150 is provided with a guide pin 154 protruding downward, and a guide hole 174 is formed in a portion of the die 170 positioned directly below the guide pin 154 to form the punch guide. It may be configured to guide the movement of the upper and lower parts of the punch guide 150 during the lower pressing movement of the 150.

In addition, the spring unit is composed of a coil spring 130 and the dish spring 140, the coil spring 130 is fitted to the outside of the punch 110, the coil spring 130 is clamp 120 ) Installed in an elastic state between the inner circumference and the punch guide 150 inner circumference.

In addition, a plurality of plate springs 140 are inserted into the coil spring 130 and the plate springs 140 are installed in an elastic state between the outer circumference of the clamp 120 and the outer circumference of the punch guide 150. .

Here, the number of the plate spring 140 may be determined according to the elasticity condition of the spring, which plate spring 140 and the other plate spring 140 adjacent to each other is provided with the same surface, In addition, the plate spring 140 and the coil spring 130 should be designed to have an elastic force of a size capable of stopping the punch guide 150 by offsetting the extrusion force of the forging material at a predetermined point.

In addition, the clamp 120, the spring unit, and the punch guide 150 outside the cover installed the punch housing 160, and the separation preventing means installed in the punch housing 160 and the punch guide 150 The punch guide 150 is prevented from being separated from the punch housing 160 through.

Here, the separation prevention means, forming a separation prevention jaw 152 along the outer circumference of the upper end of the punch guide 150, so that the separation prevention jaw 152 is caught when the punch guide 150 moves downward A stopper 162 is formed along the inner circumferential surface of the lower end of the punch housing 160.

Referring to the operation and effect of the present invention configured as described in detail as follows.

In order to manufacture the yoke 200 using the yoke manufacturing apparatus for automobile steering shaft according to the present invention, first, the aluminum forging material of AISI 6061 is introduced into the die 170 installed in the forging manufacturing apparatus as shown in FIG. 8.

Thereafter, when the upper ram 100 is driven and pressed downward, as well as the punch 110 and the clamp 120 fixed to the upper ram 100, the spring unit provided at the lower end of the clamp 120 and The punch guide 150 and the punch housing 160 are moved downward together.

As the lower portion of the punch 110 presses the upper portion of the forging material according to the movement of the upper ram 100, the forging material is processed according to the extruded groove 172 formed in the die 170, and the upper side of the yoke 200. The back extrusion action for processing the coupling portion 210 and the front extrusion action for processing the guard portion 220 at the bottom of the yoke 200 is made at the same time.

However, at this time, as the back extrusion proceeds relatively faster than the front extrusion, when the punch 110 continuously moves downward to press the forged material, the lower portion together with the punch 110 as shown in FIG. 9. The lower end of the punch guide 150 is moved in contact with the upper end (combination portion 210 of the yoke 200) of the forging material is pushed back.

As such, even when the punch guide 150 is in contact with the forged material, the punch 110 continuously moves downward to press the forged material, so that the forged material continues upward by the pressing of the punch 110. An extrusion force to be extruded back is generated, and thus the forging material pushes the punch guide 150 upward.

However, a spring unit consisting of a coil spring 130 and a plurality of dish springs 140 is provided on the punch guide 150, so that the coil springs 130 and the dish springs 140 are compressed by their elasticity. An elastic force is applied to push the punch guide 150 downward.

Accordingly, the elastic force applied from the upper punch guide 150 and the extrusion force applied from the lower punch guide 150 cancel each other, so that the punch guide 150 stops at a predetermined position where the pressure action is canceled.

Even after this, the punch 110 is continuously pressed downward by the upper ram 100 to press the forged material. As described above, the punch guide 150 temporarily blocks back forging of the forged material. As shown in FIG. 10, the forging material is concentrated and filled in a portion of the extrusion groove 172 (the guard portion 220 of the yoke 200) of the lower portion of the die 170 which is not filled by the front extrusion. 200) can be produced. Thereafter, the yoke 200 is heat-treated to complete the production of the yoke product.

As described above, the yoke manufacturing apparatus for the automobile steering shaft of the present invention performs the front extrusion and the back extrusion at the same time by pressing the forged material introduced into the die 170 at one time to manufacture the yoke 200, thereby reducing the number of processes. Simplified and no additional mold is required, thereby reducing the production cost and unit cost of the yoke 200 product, as well as improving the productivity of the product.

In addition, the yoke manufacturing apparatus for the automobile steering shaft of the present invention is forged material using the AISI 6061 aluminum material forging cold forging yoke 200, the forged processed yoke solution solution heat treatment to the aluminum material of AISI 6061-T6 By deforming, it is possible to produce a product that is light in weight and eliminates the weakness of the yoke while keeping the tensile strength and yield strength of the product in keeping with conventional hot rolled steel sheets or general steel materials.

Table 1 below shows a comparison between the tensile strength and the yield strength of the AISI 6061-T6 aluminum material used in the present invention.

Tensile Strength (MPa) Yield strength (MPa) Elongation (%) Existing creative Hot Rolled Steel Sheet for Automobile Structural Use 415 345 24 S20C 420 350 15 Reference material AISI 6061 124 55.2 25 Invention material AISI 6061-T6 330 280 14

In other words, the allowable load of the material is shown to show that it is not inferior in design even if it is changed to AISI 6061-T6 from the existing hot rolled steel sheet. The tensile strength of the material is slightly lower than that of the existing material, By adjusting the thickness, it can be seen that the allowable load is increased rather than the product manufactured using the existing hot rolled steel sheet.

Allowable load of hot rolled steel sheet: P = σπrt (1)

P = 415 × 15 × π × 5

= 97782㎏ = 97.8ton

Allowable load of AISI 6061-T6: P = σπrt (2)

P = 330 × 15 × π × 8.7

= 135292.7㎏ = 135.3ton

Furthermore, by manufacturing the yoke using aluminum materials, it improves the disadvantages of heavy load forming, parts weighting and multi-processing, which have been pointed out as problems of general steel, and realizes low fuel-forming, light weighting of parts, and high fuel efficiency with small process. By reducing the production cost of the product as shown in Table 2 below. Here, the high fuel economy is a fuel economy required for the production of the product, it is possible to realize a higher fuel economy in the aluminum material is a small process than the general steel that performs a multi-process.

Item Original part Invention parts Remarks material cost 928 653 Processing cost 750 260 General maintenance fee 251 137 15% of production cost Sum 1929 1050 879 differences

In addition, clean forming can be realized by cold forging the yoke production. That is, CO ₂ due to excessive use of cutting oil required for the existing cutting process and excessive use of electricity according to multiple processes By reducing all of these increases, environmental and technical improvements and economics can be achieved.

In addition, it is possible to continuously mass production through the forging process has a great effect on shortening the manufacturing time and cost reduction, it is possible to achieve a high quality of the parts because the internal quality is excellent and stable.

On the other hand, the present invention has been described in detail only with respect to the specific examples described above it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, it is natural that such variations and modifications belong to the appended claims. .

100: upper ram 110: punch
120: clamp 130: coil spring
140: plate spring 150: punch guide
152: release prevention jaw 154: guide pin
160: punch housing 162: stopper
170: die 172: extrusion groove
174: guide hole 180: anvil
182: core 200: yoke
210: coupling portion 220: guard portion

Claims (4)

In the apparatus for extrusion processing into a punch by inserting a forged material into the die formed with an extrusion groove so as to manufacture a yoke used in the steering shaft of the vehicle,
A clamp 120 installed on the punch 110;
A coil spring 130 inserted into an outer side of the punch 110 and installed in an elastic state between the clamp 120 and the punch guide 150;
A spring unit inserted into the coil spring 130 and including a plurality of dish springs 140 installed between the clamp 120 and the punch guide 150;
A punch guide (150) installed on the bottom of the spring unit to be slidably fitted to the outside of the punch (110), for pressurizing an upper portion of the forged material that is extruded backward from the die (170);
Covers are installed on the clamp 120, the spring unit, and the punch guide 150 on the outside, and form a separation prevention jaw 152 around the outer circumferential surface of the upper end of the punch guide 150 and the inner circumferential surface of the lower end of the punch housing 160. By the separation prevention means which formed the stopper 162 so that the separation prevention step 152 is caught;
Yoke manufacturing apparatus for a vehicle steering shaft, characterized in that it comprises a punch housing (160) for preventing the separation of the punch guide (150).


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