KR100885977B1 - Crown-forming apparatus of pulley for vehicle - Google Patents

Abstract

The present invention relates to a method for manufacturing a pulley for a vehicle and a crown forming apparatus, and more particularly, to a method for manufacturing a pulley having a crown shape consisting of a drawing process, a processing process, a crown process, and an apparatus for forming the crown.

The crown process is a process of ironing the pulley after the processing process and at the same time to form a crown on the outer peripheral surface of the pulley, the crown forming device is a device that enables this process.

Pulleys, Crowns, Ironing

Description

Crown shaping device for pulley for vehicle {CROWN-FORMING APPARATUS OF PULLEY FOR VEHICLE}

1 is a block diagram showing a manufacturing method of a vehicle pulley of the present invention;

Figure 2 (a) is a cross-sectional view of a device for performing a first drawing process of the present invention,

Figure 2 (b) is a cross-sectional view of a product that has completed the first drawing process of the present invention,

3 (a) is a cross-sectional view of a device for performing a second drawing process of the present invention,

Figure 3 (b) is a cross-sectional view of the product finished the second drawing process of the present invention,

4 (a) is a cross-sectional view of a device for performing a third drawing process of the present invention,

Figure 4 (b) is a cross-sectional view of the product finished the third drawing process of the present invention,

5 is a cross-sectional view of the finished product trimming and piercing in the processing process of the present invention,

6 is a cross-sectional view of the product finished the CNC lathe machining process of the present invention,

Figure 7 (a) is a cross-sectional view of the device for performing the crown process of the present invention,

Figure 7 (b) is a cross-sectional view of the finished product crown process of the present invention.

<Description of the symbols for the main parts of the drawings>

110: drawing process, 111: first drawing process,

112: second drawing process, 113: third drawing process,

120: machining process, 121: trimming and piercing process,

122: CNC lathe processing process, 130: crown process,

700: pulley, 701: protrusion,

702: crown, 703: inclined portion,

704: hollow part, 705, 730: press,

710: spacer, 712, 726: spring,

714: upper pad, 715: upper punch,

716: Sandai, 717, 721: Taper,

720: stripper, 722: hapunch,

724: lower pad, 725: protrusion,

727: lower pad fixing plate, 728: plate,

729: cushion pin.

The present invention relates to a vehicle pulley that is mounted to prevent tension of the belt and belt loosening during belt driving of a vehicle engine, and more particularly, to a method of manufacturing a pulley having a crown shape and an apparatus for molding the crown.

In general, the pulley is a component that is installed in the drive belt system to smoothly drive each accessory (power steering, timing belt, air conditioner, water cooling pump, etc.).

The pulley is mounted on the engine block and the bracket for the purpose of increasing the wrapping of the drive belt and maintaining the tension in order to smooth the driving.

These parts must have accurate characteristics according to the driving conditions of the vehicle engine.

If the driving condition of the vehicle engine is high speed and high pressure, the rigidity must be sufficient to prevent the pulley from being deformed by the overload such as the rotational imbalance caused by the rotating body.

Therefore, the pulley in which the bearing is mounted inside should be produced while satisfying the exact dimensional shaping condition by the welding seamless precision drawing process.

The conventional process of manufacturing such a pulley has to go through various processes using upper and lower molds, which makes the process complicated and requires manual labor between the processes, resulting in low overall productivity and high product defect rate. There was a downside.

In order to solve this problem, Patent No. 10-0288892 describes a drawing apparatus and a manufacturing method of an automobile engine pulley.

However, the invention disclosed in the above publication has the following problems.

First, in order to flatten the iron branches of the specimens, a separate protrusion was formed in a columnar shape on the upper die, which increased the partial load and slip resistance of the shape drawing or the angular drawing product, thereby requiring the effect of suppressing wrinkles and reducing raw materials. As it is used in the drawing technique, when forming and drawing such a circumferential protrusion in the circular drawing for manufacturing the pulley, the frictional resistance applied to the material due to the protrusion increases, thereby reducing the thickness of the material and finally the product. This can increase the defective rate.

In addition, in manufacturing the upper die, not only a separate process is required to make the protrusions, but also a manufacturing problem in that the protrusions in the form of cylinders are formed.

Secondly, it is said that a predetermined reaction force is exerted by using hydraulic pressure during reverse drawing, and a separate hydraulic device is required for the action of the hydraulic pressure, and a lot of cost is required, such as sealing to prevent leakage of oil by hydraulic pressure. There is a problem in that a structure, such as a bar, to be installed in the lifting surface, and also in the manufacturing surface is complicated.

Third, since the piercing process is performed after the ironing process, there is a problem that the ironed pulley deformation may occur when the piercing process is performed.

Fourthly, the pulley manufactured by the above invention is a flat pulley whose outer peripheral surface is flat, so that the corresponding surface of the belt mounted on the pulley becomes flat like the outer peripheral surface of the pulley to achieve a flat single flat contact.

Therefore, when the belt is driven, the center does not exactly coincide with the outer circumferential surface of the pulleys, and the belt is fluctuated in the width direction in accordance with the driving, that is, the center is continuously changed and thus the driving stability is inferior.

This causes not only the wear of the belt coupled to the pulley is large, but also shortens the life of the bearing mounted in the pulley.

Fifth, the above invention does not have a process or apparatus for only the ironing process and to solve the fourth problem described above, the cost according to the installation of a separate process or apparatus to solve this problem There is a problem that a lot of processes are increased and workability and productivity are deteriorated, and a pulley may be deformed due to the execution of a separate process or apparatus.

The present invention has been made to solve the above-mentioned problems, and the ironing and crown of the pulley as a device for forming a crown on the outer peripheral surface of the pulley, that is, the driving stability even at high speed rotation and a method for manufacturing the same It is an object of the present invention to provide a method for manufacturing a pulley for a vehicle to perform molding simultaneously.

In order to achieve the above object, a method of manufacturing a vehicle pulley according to the present invention includes a drawing process of drawing a metal plate to have a shape of a pulley; A processing step of cutting the outer diameter portion of the pulley after the drawing process and drilling the center portion; Ironing the pulley after the processing process (ironing) and at the same time the outer peripheral surface is formed in the crown process to form a crown to be convex outward.

The drawing step may include a first drawing step of drawing a metal sheet into a cup shape using a press; A second drawing process of drawing a central portion of a first product produced by the first drawing process in a reverse direction; And a tertiary drawing process in which the protrusion of the secondary product produced by the secondary drawing process is inclined with respect to the inner circumferential surface of the secondary product.

In addition, in order to achieve the above object, the crown shaping device of the vehicle pulley of the present invention is vertically moved by a press and an upper die having a hole in the center; An upper pad disposed in a hole of the upper die and supported by a spring; A stripper including an upper punch penetrating the center of the upper pad and fixedly disposed, and a stripper supported by a spring at an upper portion of the plate and having a hole formed at the center thereof; A lower punch disposed in the hole of the stripper and fixedly disposed on the plate; It consists of a lower mold including a lower pad penetrating the center of the lower punch and supported by a cushion pin.

At this time, the cushion pin is by a mechanical press installed pneumatic device.

A taper is formed outwardly at a lower portion of the hole of the upper die and an upper portion of the hole of the stripper, and an inclination of the upper pad is inclined toward the center portion, and an upper portion of the lower punch is inclined of the upper pad. The slope is made to correspond to.

In addition, a protrusion is formed at an upper portion of the lower pad to insert a center hole of a pierced and trimmed pulley, and the protrusion is in contact with a lower portion of the upper punch as the upper mold moves downward.

At this time, the height of the protrusion is lower than the thickness of the pierced and trimmed pulley, the diameter of the upper punch is smaller than the diameter of the lower pad, the spacing between the upper punch and the lower pad is of the pierced and trimmed pulley Narrower than thickness

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

1 is a block diagram showing a method for manufacturing a vehicle pulley of the present invention.

As shown in FIG. 1, the method for manufacturing a vehicle pulley according to the present invention includes a drawing process 110, a processing process 120, and a crown process 130.

The drawing process 110 is a process of drawing a metal plate using a press to have a shape of a pulley. The first drawing process 111, the second drawing process 112, and the third drawing process 113. Is done.

The machining process 120 cuts the outer diameter portion of the pulley that has completed the drawing process 110 while cutting and piercing the center of the center and a pulley that has completed the trimming and piercing process 121 to the CNC lathe machine tool. It consists of a CNC lathe processing process 122 for side processing.

By removing the metal bar generated by the trimming and piercing by the CNC lathe processing step 122, it is possible to install a pulley or to manufacture a pulley having a safe and accurate dimensions when operating the pulley.

In addition, the crown process 130 is a finishing process for ironing the pulley after the machining process 120 and at the same time the outer peripheral surface to form a convex outwardly.

In the drawing process 110 and the crown process 130 by using a mechanical press installed with a pneumatic device, minimizing the defect rate of the product by suppressing the wrinkles of the product (pulley) and having a certain thickness without the need for a separate hydraulic device can do.

In addition, since the trimming and piercing process 121 and the ironing according to the crown process 130 is performed, it is possible to prevent the deformation of the pulley by the conventional piercing process.

In addition, by using the water-soluble drawing oil in the drawing process 110, it is possible to reduce the friction generated between the device performing the drawing process 110 and the product to improve the cooling and lubricity.

2 (a) is a cross-sectional view of a device for performing the first drawing process 111 of the present invention, Figure 2 (b) is a cross-sectional view of a product that has completed the first drawing process 111 of the present invention.

The first drawing step 111 is a step of drawing a metal plate in a cup shape using mechanical presses 205 and 230 provided with a pneumatic device. The upper press 205 and the spacer 210 are shown in FIG. 2. ), Upper pads 214, springs 212, upper dies 216, and the like, and halfless 230, lower punch 220, blank holder 222, plate 224, and air holes 228. ), A lower mold consisting of a cushion pin 226 and the like (mold).

The spacer 210 is fixedly mounted by the upper press 205, and an upper die 216 having a hole formed in a central portion thereof is fixedly mounted at a lower portion of the spacer 210, and in the hole of the upper die 216. The upper pad 214 is disposed while being supported by the spring 212.

In addition, the plate 224 is fixedly mounted on the upper portion of the halfless 230, and the blank holder 222 is disposed on the upper portion of the plate 224 while being supported by the cushion pin 226. The lower punch 220 penetrates through the center of the holder 222 to be fixed to the plate 224.

The lower punch 220 is introduced into a hole formed in the upper die 216, and an air hole 228 is formed therein, and has a cup shape.

The first drawing process 111 is performed as follows.

First, a metal plate material of a disc-shaped material is placed on the blank holder 222, wherein the metal plate material maintains a parallel line with the lower punch 220, and the blank holder 222 is formed by the cushion pin 226. The cushion is under pressure.

The presses 205 and 230 are mechanical presses of up to 150 tons. When the press 205 is operated, the upper die is lowered while the upper die 216 and the blank holder 222 are in contact with each other. The upper pad 214 is lifted up by the lower punch 220 and the blank holder 222 is lowered by the cushion pin 226 so that the metal sheet has a shape of the primary product having the shape of the lower punch 220. 200).

At this time, the cushion pin 226 is lowered while receiving the set air cushion pressure continuously, by using a mechanical press installed air cushion, that is, a pneumatic device can suppress the wrinkles of the product and maintain a constant thickness.

Air generated while the metal sheet is lowered is automatically discharged by the air hole 228 formed in the lower punch 220.

At the end of the work, the upper mold is raised and the cushion pin 226 raises the blank holder 222 by the force of the air cushion, thereby making the cup-shaped primary product as shown in FIG. 200 is taken out.

In this case, the first drawing process 111 is to make the upper center portion 202 of the primary product 200 to be concave, as shown in Figure 2 (b) when drawing the second drawing process (112) It is preferable because the reverse drawing can be made smoothly.

This can be achieved by forming a large air hole 228 in the upper portion of the lower punch 220.

It is easy to taper or curve outward from the lower portion of the hole of the upper die 216 when the primary product 200 is removed from the lower punch 220.

3 (a) is a cross-sectional view of a device for performing the second drawing process 112 of the present invention, Figure 3 (b) is a cross-sectional view of a product that has completed the second drawing process 112 of the present invention.

The secondary drawing process 112 is a process of drawing the central portion 202 of the primary product 200 produced by the primary drawing process 111 in the reverse direction, as shown in FIG. It is performed by the upper and lower molds as shown.

The upper mold is an upper press 305, a spacer 310 fixedly mounted to the upper press 305, an upper die 316 fixedly mounted at a lower portion of the spacer 310, and having a hole at a center thereof, and the upper die 316. The upper pad 314 is disposed in the hole of the) and supported by the spring 312, the upper punch 315 is fixedly mounted to the spacer 310 through the upper pad 314, the air hole formed therein Is done.

The lower mold includes a plate 324 fixedly mounted on the upper halfless 330, a blank holder 322 disposed on the plate 324 and supported by the cushion pin 326, and the blank holder 322. The lower punch 320 is fixed to the plate 324 and penetrates the center of the plate and has an air hole 328 therein.

The lower punch 320 is inserted into a hole formed in the upper die 316, and a groove corresponding to the diameter of the upper punch 315 is formed at the center thereof so that the upper punch 315 may be inserted.

That is, cylindrical protrusions surrounding the grooves are formed along the outer circumferential surface of the lower punch 320.

The second drawing process 112 consisting of the upper mold and the lower mold is performed as follows.

First, the first product 200 having completed the first drawing process 111 is placed on the blank holder 322, wherein the blank holder 322 is under cushion pressure by the cushion pin 326. It is a state.

When the press 305 is operated, the upper die is lowered while the upper die 316 and the blank holder 322 are in contact with each other. When the upper die is continuously lowered, the upper pad 314 is moved upward by the lower punch 320. Go up and the blank holder 322 lowers the cushion pin 326.

In this case, the upper punch 315 fixedly supported by the spacer 310 is inserted into the groove of the lower punch 320 so that the lower portion of the upper punch 315 and the lower hole of the lower punch 320 are formed. When fully contacted, the upper pad 315 is no longer moved upward, so that the primary product 200 is made of the secondary product 300 having a cross-sectional shape of the lower punch 320.

The air hole 328 and the cushion pin 326 have the same effect as the first drawing process 111, and thus a detailed description thereof will be omitted.

When the work is finished, the upper mold is raised upward and the cushion pin 326 lifts the blank holder 322 by the force of the air cushion, and thus the protrusion 302 is formed on the outer circumferential surface as shown in FIG. The secondary product 300 having the formed shape is taken out.

At this time, by giving a predetermined amount of taper to the inner diameter of the upper die 316 and the outer diameter of the lower punch 320, the crown process 130 to be performed later can be easily performed.

4 (a) is a cross-sectional view of the apparatus for performing the third drawing process 113 of the present invention, Figure 4 (b) is a cross-sectional view of a product that has completed the third drawing process 113 of the present invention.

In the third drawing process 113, the protrusion 302 of the second product 300 produced by the second drawing process 112 is inclined with respect to the inner circumferential surface of the second product 300. As a shape drawing process, the upper mold and the lower mold as shown in Fig. 4A are performed.

The upper and lower molds used in the third drawing process 113 are different from the upper and lower molds used in the second drawing process 112, except that the upper pad 414 and the lower punch 420 have different shapes. The same bar will be described based on the upper pad 414 and the lower punch 420.

Otherwise, the first drawing step 111 and the second drawing step 112 may be referred to, and will be omitted below.

The center of the lower punch 420 is formed with a groove corresponding to the diameter of the upper punch 415 so that the upper punch 415 can be inserted.

That is, a cylindrical protrusion 421 surrounding the groove is formed along the outer circumferential surface of the lower punch 420.

The protrusion 421 forms an inclination 423 with respect to the inner circumferential surface, so that the crown process 130 to be performed later is easily performed.

In addition, when the bearing is to be mounted on the inner circumferential surface 402 of the pulley, when the inclined 423 is formed on the inner circumferential surface 420 of the pulley, the work space required for mounting the bearing is widened, thereby facilitating the work.

At this time, the protrusion 421 is preferably such that the inclination 423 with respect to the inner circumferential surface is formed to be more gentle than the inclination with respect to the outer circumferential surface, which is to be performed later in the crown process 130, the crown on the outer circumferential surface 403 of the pulley This is to facilitate formation and to ensure that the crown has the correct dimensions.

A groove corresponding to the shape of the protrusion 421 of the lower punch 420 is formed below the upper pad 414.

The third drawing process 113 including the upper mold including the upper pad 414 and the lower mold including the lower punch 420 is performed like the second drawing process 112.

However, as shown in FIG. 3B, the protrusion 401 is inclined with respect to the inner circumferential surface 402 by the upper pad 414 and the lower punch 420. It will have a shape to form.

5 is a cross-sectional view of the product after the trimming and piercing process 121 of the machining process 120 of the present invention, Figure 6 is a cross-sectional view of the product after the CNC lathe machining step 122 of the machining process 120 of the present invention to be.

As shown in FIG. 5, the pulley having finished the drawing process 110 is cut out of the outer diameter portion 504, and the hollow portion 502 is formed by drilling a central portion having a diameter necessary to connect the bearing and the shaft. do.

The trimming and piercing process 121 can be performed using a generally known apparatus.

As shown in FIG. 6, the side surface of the trimming and piercing process 121 is processed using a CNC lathe.

By the CNC turning process 122, the side surface of the pulley can be smoothly processed without ironing.

Figure 7 (a) is a cross-sectional view of the device for performing the crown process 130 of the present invention, Figure 7 (b) is a cross-sectional view of the finished product crown process 130 of the present invention.

The crown process 130 irons the thickness and size of the pulley 600 that has completed the processing process 120 to a predetermined standard, and simultaneously forms a crown convexly on the outer circumferential surface thereof. As a finishing process, it is performed by an apparatus composed of an upper mold and a lower mold as shown in Fig. 7A.

The upper mold includes an upper press 705 that moves up and down, a spacer 710 fixedly mounted to the upper press 705, an upper die 716 fixedly mounted to a lower portion of the spacer 710, and having a hole in a central portion thereof, the upper upper press 705. An upper pad 714 disposed in a hole of the die 716 and supported by a spring 712, and an upper punch 715 fixedly mounted to the spacer 710 through a center of the upper pad 714. It is done by

The lower mold is mounted on a plate 728 fixedly mounted on the upper halfless 730, a lower punching fixed plate 727 fixedly mounted on the upper portion of the plate 728, and a spring 726 installed on the lower punching fixed plate 727. The lower puncher 722, which is supported by the stripper 720 having a hole in the center, is disposed in the hole of the stripper 720, and is fixed to the upper plate 728 by the lower punching fixing plate 727. And a lower pad 724 penetrating the center of the punch 722 and supported by the cushion pin 729.

The cushion pin 729 is by mechanical press (705, 730) is installed pneumatic device.

In addition, tapers 717 and 721 are formed in the lower portion of the hole of the upper die 716 and the upper portion of the hole of the stripper 720.

This is a space for forming the crown 702 so that the outer peripheral surface of the pulley is convex outward due to the pressure applied to the upper and lower portions of the pulley when the upper mold and the lower mold are in contact with each other.

When the crown 702 pulleys having various shapes are to be manufactured, the upper die 716 and the stripper 720 having tapers 717 and 721 having appropriate angles may be manufactured by replacing them.

As such, by forming the crown 702 outwardly on the outer circumferential surface of the pulley 700, the belt is pulled by the property of moving the length of the circumference when the pulley 700 is rotated without a separate guide or flange. Departure from 700) can be prevented.

At this time, the crown 702 is preferably such that the length of the central portion of the outer peripheral surface of the pulley 700 is formed the longest.

A lower portion of the upper pad 714 is inclined toward the center portion, and an upper portion of the lower punch 722 is inclined to correspond to the inclination of the upper pad 714.

This allows the protrusion 701 of the pulley 700 to form the inclined portion 703 with respect to the inner circumferential surface to facilitate the operation as described above, and to keep the thickness and size of the pulley 700 constant. This is to form a crown 702 of a predetermined size on the outer peripheral surface of the (700).

A protrusion 725 is formed at an upper portion of the lower pad 724, which is a hollow portion 704 of the pulley which has completed the processing process 120, and is inserted in the pull pad in performing the crown process 130. There is an effect that can reduce the deterioration of the product due to the departure and misalignment of (700).

At this time, the diameter of the protrusion 725 should be substantially the same as the diameter of the hollow portion 704 of the pulley, the protrusion 725 is in contact with the lower portion of the upper punch 715 as the upper mold moves downward.

In order to perform ironing so that the pulley that has finished the processing process 120 has a predetermined size and thickness, the height of the protrusion 725 is smaller than the thickness of the pulley that has completed the processing process 120, and the upper punch 715. The diameter of the lower pad 724 is smaller than the diameter, and the gap between the upper punch 715 and the lower punch 722 should be narrower than the thickness of the pulley after the processing step 120.

In this way, the pulley having finished the processing step 120 by the contact between the upper mold and the lower mold has a uniform thickness and size determined by firing.

At this time, the inner diameter bearing tolerance and the step depth is ± 0.08, the outer diameter crown one side is preferably 0.08 or less, the outer diameter roundness is preferably 0.08 or less.

To this end, the inner diameter of the pulley 700 into which the bearing is to be inserted is precisely machined to fit the upper punch 715 and the lower punch 722, and the step depth is the length of the upper punch 715 and the lower depth. The length of the pad 724 is precisely shaped and the crown 702 is formed by giving taper 717 and 721 to the upper die 716 and the stripper 720, respectively.

That is, the inner diameter of the pulley 700 is determined by the diameter of the upper punch 715, the step depth is determined by the length of the upper punch 715 and the lower pad 724, the thickness is the projection 725 ) And the spacing between the upper punch 715 and the lower punch 722.

The crown process 130 by the device consisting of the upper and lower molds as described above is made as follows.

First, a product (pulley) having finished the processing process 120 is placed on the stripper 720. At this time, the hollow part 704 of the pulley is inserted into and fixed to the protrusion 725 formed on the lower pad 724. The outer circumferential surface of the pulley is disposed on a taper 721 formed on the stripper 720.

The presses 705 and 730 are mechanical presses of up to 150 tons. When the press 705 is operated, the upper die is lowered, and the lower portion of the upper punch 715 and the protrusion 725 of the lower pad 724 are mutually inclined. A lower portion of the upper pad 714 and an upper portion of the lower punch 722 are adjacent to each other with the pulley in the middle, and the upper die 716 and the stripper 720 are also adjacent to each other with the pulley in the middle. Done.

That is, the inclined surface of the lower punch 722 is disposed below the inclined portion 703 of the protrusion 701 of the pulley, the inclined surface of the upper pad 714 above the inclined portion 703 of the protrusion of the pulley. Is placed.

As the lowering of the upper die continues, the upper pad 714 rises, and the stripper 720 and the lower pad 724 receive the force of the spring 726 and the cushion pressure by the cushion pin 729, respectively. Will descend.

Ironing occurs between the upper punch 715 and the lower pad 724 due to the lowering of the upper punch 715, and the pulley 700 also lowers due to the lowering of the lower pad 724. The lower punch 722 is relatively raised, so that the inner circumferential surface of the pulley 700 is ironed between the side of the upper punch 715 and the side of the lower punch 722.

At the same time or at some time intervals, the pulley 700 is disposed on the tapers 717 and 721 formed on the upper die 716 and the stripper 720 by the contact of the upper die 716 and the stripper 720. Pressure is applied to the upper and lower portions of the outer circumferential surface of the pulley 700 so that the crown 702 is formed to be convex outward in a space where the taper 717 and 721 are formed.

At this time, when the upper and lower molds meet each other completely at the bottom dead center of the press, the pulley 700 in the upper and lower molds satisfies all dimensions, that is, is fully ironed and at the same time the upper die 716 and the stripper 720. The formed taper 717, 721 forms a crown 702 having a predetermined precise dimension on the outer circumferential surface of the pulley 700.

At the end of the work, the upper die is raised and the stripper 720 pushes up the pulley 700 completed by the spring 726, and the lower pad 724 is subjected to air cushion pressure by the cushion pin 729. After the upper and lower molds are returned to their original state, the pulley 700 having the crown 702 is formed may be taken out.

As described above, by simultaneously performing crowning to convex the outer circumferential surface and the ironing to fit the pulley to a constant thickness and size, by maintaining the inner diameter bearing tolerance and step depth of the pulley 700 by the ironing on the outer circumferential surface It is possible to form a crown 702 of a constant size to produce a pulley 700 of the correct dimensions to minimize the defective rate of the product.

In addition, by performing two operations in one process, the number of molds or apparatuses required for this can be reduced, thereby reducing the cost and simplifying the process, thereby improving workability and productivity.

In the present invention, all the processes except for the CNC lathe process 122 are made by the press method, the production process is simplified, the manual process is reduced, workability is improved, and pulleys having a more accurate dimension can be produced, and thus the third generation product method. This can be called.

The method of manufacturing a vehicle pulley and the crown forming apparatus of the present invention are not limited to the above-described embodiments, and may be variously modified and implemented within the allowable technical spirit of the present invention.

According to the manufacturing method and the crown molding apparatus of the vehicle pulley of the present invention as described above has the following effects.

First, by forming a convex crown outwardly on the outer circumferential surface of the pulley, there is an effect that can prevent the belt from moving out due to the property of moving the length of the circumference toward the longer side when the pulley rotates without a separate guide or flange have.

This can reduce the wear of the belt coupled to the pulley, as well as to extend the life of the bearing mounted in the pulley.

Second, ironing after finishing trimming and piercing can prevent deformation of the pulley that occurs when piercing.

Third, by simultaneously performing the ironing to match the pulley to a certain standard and the crown forming to convex the outer peripheral surface, by forming the crown of constant size on the outer peripheral surface while maintaining the inner diameter bearing tolerance and step depth of the pulley by the exact dimension It is possible to produce a pulley of the correct dimensions to minimize the defect rate of the product.

In addition, the two operations in one process can reduce the number of molds or devices required for this process, which can reduce costs, simplify the process, improve workability and productivity, and separately perform crown molding after ironing. When the dimensional deformation of the pulley that occurs in the case to be performed by one process there is an effect that can be prevented.

Fourth, by forming the upper center of the primary product concave in the primary drawing process, there is an advantage to smoothly reverse drawing during the secondary drawing process.

Fifth, the inclination of the protrusion of the secondary product in the third drawing process is formed to be more gentle than the inclination of the outer peripheral surface, so that it is more easily formed when forming the crown on the pulley in the crown process. It is possible to achieve symmetry and to have a more accurate dimension.

Sixth, by using the water-soluble drawing oil in the drawing process, it is possible to reduce the friction generated between the mold or the device and the product, there is an effect that can improve the cooling and lubricity.

Seventh, by using a mechanical press equipped with a pneumatic device in the drawing process and the crown process, it is possible to reduce wrinkles and have a certain thickness of pulleys without installing or using a separate hydraulic device, thereby reducing costs and minimizing product defect rate. It has an effect.

Eighth, all processes except the CNC lathe process by the press method, the product manufacturing process is simplified, the manual process is reduced, workability is improved and there is an effect that can produce a pulley with more accurate dimensions.

Ninth, in the crown manufacturing apparatus of the pulley, the taper is formed outwardly at the lower portion of the hole of the upper die and the upper portion of the hole of the stripper, there is an effect that the crown can be easily formed on the outer peripheral surface of the pulley.

Tenth, in the crown manufacturing apparatus of the pulley, by inclining the lower portion of the upper pad toward the center and to form a slope corresponding to the upper portion of the lower punch, the outer peripheral surface of the pulley while maintaining the thickness and size of the pulley constant There is an effect that can be formed in the crown of a certain size.

Eleventh, in the crown manufacturing apparatus of the pulley, by forming a projection for inserting the center hole of the pulley in the upper portion of the lower pad, it is possible to reduce the deterioration of the product due to the separation and misalignment of the pulley during ironing and crown formation There is an advantage.

Twelfth, the effect of ironing can be obtained by making the height of the projection of the lower pad and the gap between the upper punch and the lower punch smaller and smaller than the thickness of the pierced and trimmed pulley.

Claims (4)

An upper die which is moved up and down by a press and a hole is formed in the center; An upper pad disposed in a hole of the upper die and supported by a spring; An upper mold including an upper punch that is fixedly disposed through the center of the upper pad, A stripper supported by a spring at the top of the plate and having a hole formed at the center thereof; A lower punch disposed in the hole of the stripper and fixedly disposed on the plate; Is made of a lower mold including a lower pad penetrating the center of the lower punch and supported by a cushion pin, In the lower part of the hole of the upper die and the upper part of the hole of the stripper, a taper is formed outward, respectively, The lower portion of the upper pad is inclined toward the center, the upper portion of the lower punch is inclined to correspond to the inclination of the upper pad, The diameter of the upper punch is smaller than the diameter of the lower pad, the spacing between the upper punch and the lower punch is narrower than the thickness of the pierced and trimmed pulley, the crown forming apparatus for a vehicle pulley. The method of claim 1, The cushion pin is a crown forming apparatus for a vehicle pulley, characterized in that by a mechanical press installed pneumatic device. The method according to claim 1 or 2, The upper part of the lower pad is formed with a projection is inserted into the center hole of the pulley pierced and trimmed, the projection is formed in the crown of the vehicle pulley, characterized in that the upper contact with the lower portion of the upper punch. The method of claim 3, wherein The height of the projection is a crown forming apparatus for a vehicle pulley, characterized in that lower than the thickness of the pierced and trimmed pulley.

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