KR20050029092A - Method and apparatus for manufacturing shell nut - Google Patents

Abstract

To provide a method and an apparatus capable of manufacturing a shell nut for automobile at once by a multistage pressure forming machine, and a method and an apparatus capable of integrally manufacturing a shell nut for automobile by a multistage pressure forming machine. The method for manufacturing a shell nut comprises a pre-process of obtaining a cylindrical work(40) by cutting a raw material for shell nut manufacture at a cutting knife block of a multistage forming machine; a first process of obtaining a first processed work(42) by transferring the cylindrical work to a processed work placement part of die of first stage so that the cylindrical work is inserted into a placement space and supported by a die side supporting rod and moving a punch such that the punch presses both cross sections of the cylindrical work; a second process of obtaining a second processed work(44) on a punch side portion of which a groove is formed, and a die side portion of which is slantly chamfered by reversely transferring the processed work(42) to a processed work placement part of die of second stage so that the processed work is placed in a placement space and pressing both surfaces of the processed work by die side supporting rod and punch side pressing rod; a third process of obtaining a third processed work(46) on die side portion of which closed thin circular groove is formed, and a body of punch side portion of which is first extruded in a pipe shape by transferring the second processed work(44) to a processed work placement part of die of third stage so that the processed work is placed in a placement space and pressing the second processed work by punch pin, punch side sleeve and die pin, and die side sleeve; a fourth process of obtaining a fourth processed work(48) on punch side portion of which a body part pipe shape is second extruded, and on die side portion of which a base circular groove of piercing is formed by transferring the third processed work(46) to a processed work placement part of die of fourth stage so that the processed work is placed in a placement space and pressing both ends of the processed work by punch pin, die pin and die side sleeve; and a fifth process of obtaining a shell nut finished product(50) by transferring the fourth processed work(48) to a die of fifth stage so that the processed work is placed in a placement space and pressing the processed work by punch pin and punch side sleeve, thereby piercing inner diameter of a hexagonal portion on a lower part of the work.

Description

Shell Nut Manufacturing Method and Apparatus {METHOD AND APPARATUS FOR MANUFACTURING SHELL NUT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of vehicle components, and more particularly to a method and apparatus for manufacturing shell nuts for automobiles.

One of the vehicle parts, a shell nut, is a connector for delivering a high pressure fluid such as an automobile brake hose and a fuel hose, and is mainly used for a connection portion of a rubber hose where tight airtightness is strictly required. The body of the connection part consists of a metal shell nut and bush, among which the shell nut has a generally thin pipe shape (body material) having one end at a circular through hole, and the other end has a hexagon nut shape ( Nut material).

Conventionally, the shell nut was manufactured by separately manufacturing each of the shell material and the nut material in the shell nut using a multi-stage molding machine. Multi-stage molding machine that manufactures body material and nut material, respectively, is a multi-stage pressure molding method for forming a large amount of precise products.

1 is a view showing a shell nut manufacturing process according to the prior art.

Referring to Figure 1, first, the body material is manufactured using a multi-stage molding machine consisting of a preliminary process and the main process of four steps, and the nut material is used independently of the multi-stage molding machine consisting of a preliminary process and a three step main process. To prepare. Thereafter, the shell material is manufactured by welding the body material and the nut material manufactured by the multi-stage molding machine.

Process development according to the prior art as described above consists of 10 process steps, there are the following problems.

(1) Manufacturing each product material (body material, nut material) separately takes more than twice the manufacturing time. Moreover, the total process time is more than three times because each material must be manufactured separately and then welded.

(2) The conventional manufacturing method is difficult to guarantee the accuracy of the dimensions. Since the product material is manufactured in a separate form and assembled, the defect rate of the product is very high due to the accumulation of tolerances in each process and the effect of shrinkage expansion due to heat during assembly and assembly through welding.

(3) The shell nut according to the manufacturing method of the prior art is a welded product, but the welded product utilizes the property that the metal is melted at a high temperature. Although the welding process is easy in the manufacturing method, the material bonding strength between the products has a lower strength of 50% or less than that of the integrated type. In addition, the metal fiber flow (metal fiber flow) is processed in a separated state has a structure that is vulnerable to mechanical properties such as tensile strength, fatigue strength of the metal.

It is therefore an object of the present invention to provide a shell nut manufacturing method and apparatus which can manufacture a shell nut for automobiles in a multi-stage molding machine at one time.

It is another object of the present invention to provide a shell nut manufacturing method and apparatus for enabling an integral manufacturing of a shell nut using a multi-stage molding machine.

According to the above object, the present invention is a shell nut manufacturing method using a multi-stage molding machine (2), wherein the raw material for manufacturing is cut in the cutting knife block 20 of the multi-stage molding machine (2) to obtain a cylindrical material (40) The preliminary process and the cylindrical material 40 is transferred to the processing material seating portion 56 of the die 54 of the first end 52, inserted into the seating space, seated to be supported by the die-side support rod 60, and punched. A first step of moving the 58 to punch the both end faces of the cylindrical material 40 to obtain a first work material 42 having a top and bottom surface; and a second end 64 of the work material 42. The die 66 is transferred up and down to the workpiece mounting portion 68 of the die 66, and is inserted and seated in the seating space. The die-side support rod 70 and the punch-side pressure rod 74 are placed on both sides of the workpiece 42. Recessed groove having an inner rim inclined by several tens of degrees And a second step of obtaining a second work piece 44 chamfered at an inclination angle at least lower than the inclination angle of the inner edge, and the second work piece 44 being formed in the third stage 76. Transfer to the processing material seating portion 80 of the die (78) of the die and insert into the seating space and the second processing material 44 punch pin 86, punch side sleeve 88 and the die pin 83 And a third process of pressing the die-side sleeve 83 to form a shallow circular recessed groove in which the die-side portion of the material is blocked, and the punch-side portion to obtain a first workpiece 46 whose body is first extruded into a pipe shape. And, the third processing material 46 is transferred to the processing material seating portion 118 of the die 112 of the fourth end 110 is inserted and seated in the seating space and the punch 138 to move the punch pin 140 Press both ends of the workpiece (46) using the die pin (124) and the die sleeve (126) so that the punch side of the workpiece A fourth step of obtaining a fourth processed material 48 in which the shape is secondly formed by the second extrusion process and the die-side portion of the raw material is formed at the same time as the hexagonal extrusion process and the basic groove of the perforation is formed; and the fourth processed material ( 48 is transferred to the die 152 of the fifth end 150 to be inserted and seated in the seating space of the workpiece mounting portion 154, and the fourth workpiece is processed using the punch pin 162 and the punch side sleeve 164. And pressurizing the 48 to drill the inner diameter of the lower end of the raw material to obtain the shell nut finished product 50.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are represented by the same numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

If the shell nut is manufactured in one piece by using multi-stage pressure forming method, there are advantages such as productivity and cost surface.However, it is impossible to manufacture the body material of pipe and hexagon nut in one piece as the limitation of mold technology. It was recognized. Thus, the embodiment of the present invention implements a manufacturing method and apparatus capable of manufacturing the shell nut in one piece while using a multi-stage molding machine.

Due to the nature of the mold, the extrusion process is generally performed, and there are no examples of simultaneous machining in both directions. For this reason, it is recognized as a basic construction method of a multi-stage molding machine, in which one side is extruded in a general form, and then another part is extruded in the next step. It is difficult to shape the metal mold, and even if a similar type is formed, it is difficult to form a good metal flow shape in the hexagonal section at the bottom and the pipe joint at the top. In the embodiment of the present invention is designed to enable the simultaneous extrusion and processing of the upper and lower molds as a completely new form.

Figure 2 is a side cross-sectional view of a general multi-stage pressure molding machine for the understanding of the present invention, Figure 3 is a plan view capturing the working moment of the multi-stage pressure molding machine for the understanding of the embodiment of the present invention.

2 and 3, the multi-stage pressure forming machine 2 is mainly composed of a die side fixing portion 4 and a punching side driving portion 6, and a die block 10 at the tip of the die side fixing portion 4. ) Is mounted, and a punch block 12 is mounted at the tip of the punch-side drive unit 6. The die block 10 and the punch block 12 of each stage are provided with a die mold (22 in FIG. 3) and a punch mold (28 in FIG. 3) according to an embodiment of the present invention.

In Figure 3, reference numeral "20" of Figure 3 is a cutting knife block for cutting the material to be processed, "24" is a forceps jig located in each step, "26" is picked up by the forceps jig 24 and then It is the processing material which is moved to the stage.

4 is a preliminary step of cutting the material to be processed in the drawing showing the shell nut processed material by the multi-stage molding machine 2 according to an embodiment of the present invention by process and the present process of # 1 to # 5 process.

5 to 9 are concrete structural diagrams of dies and punch dies corresponding to respective stages of the multi-stage molding machine 2 according to the embodiment of the present invention. In more detail, FIG. 5 is a detailed structural diagram of a die and a punch mold corresponding to the first stage 52 of the multi-stage molding machine 2 according to the embodiment of the present invention, and FIG. 6 is a multi-stage type according to the embodiment of the present invention. 7 is a detailed structural diagram of a die and a punch die corresponding to the second end 64 of the molding machine 2, and FIG. 7 illustrates a die corresponding to the third end 76 of the multi-stage molding machine 2 according to the embodiment of the present invention. Concrete structure diagram of a punch die. 8 is a detailed structural diagram of a die and a punch mold corresponding to the fourth stage 110 of the multi-stage molding machine 2 according to an embodiment of the present invention, Figure 9 is a multi-stage molding machine 2 according to an embodiment of the present invention Specific structure diagrams of the die mold and the punch mold corresponding to the fifth stage 150 are shown.

According to an embodiment of the present invention, the manufacturing process by the novel multi-stage molding machine 2 is made of a preliminary process and the present process of steps # 1 to # 5, and for each of the processes, FIGS. 2 to 9. Will be described in detail with reference to.

(A) Preliminary Process

As shown in FIG. 4 by cutting the surface of the cutting die of the cutting knife block 20 of FIG. 2 provided with the multi-stage molding machine 2 by cutting a circular wire in a linear motion. Similarly, the cylindrical material 40 is obtained.

(B) # 1 process

Process # 1 will be mainly described with reference to FIG. 5, which shows a concrete structure of a die and a punch mold corresponding to the first stage 52 of the multi-stage molding machine 2 according to the embodiment of the present invention.

The cylindrical raw material 40 cut in the preliminary process is transferred by a tong jig located between the cutting knife block 20 and the first end 52 of the multi-stage molding machine 2 to die die of the first end 52 ( The die is then inserted into the workpiece seat 56 of the die 54. The die-side support rod 60 is inserted into the lower portion of the seating space of the workpiece seating portion 56 in the lower portion of the workpiece seating portion 56, and the cylindrical material inserted and seated in the workpiece seating portion 56 ( 40) to support the lower surface.

Thereafter, the punch 58 of the multi-stage molding machine 2 is lowered to press-punch the upper surface of the cylindrical material 40 on which the punch-side pressure bar 62 of the first stage punch 58 is inserted and seated. As a result, the cut upper and lower surfaces of the cylindrical material 40 are corrected by pressing through the die-side supporting rod 60 and the punch-side pressing rod 62, and the workpiece 42 as shown in Figs. Is obtained. Correcting the cut upper and lower surfaces (cut surfaces) of the cylindrical material 40 is intended to achieve uniformity of the internal structure of the cylindrical material 40 while securing a flat portion by correcting the uneven portion formed on the cut surface. As described above, it is only possible to secure the moldability in a subsequent process that is developed only after securing the flat part and uniformizing the internal structure.

(C) # 2 process

Process # 2 will be mainly described with reference to FIG. 6, which shows the concrete structure of the die and punch mold corresponding to the second stage 64 of the multi-stage molding machine 2 according to the embodiment of the present invention.

The workpiece 42, which has undergone the # 1 process, is moved upside down while being moved by a tong jig positioned between the first end 52 and the second end 64 of the multi-stage molding machine 2, and the direction of the second stage 64 is changed. It is seated in the seating space of the workpiece mounting portion 68 of the die (66). The die-side supporting rod 70 is slightly inserted into the seating space of the workpiece seating portion 68 at the lower portion of the workpiece seating portion 68, and thus the preformed material inserted and seated in the workpiece seating portion 68 42) to support the lower surface. The lower edge of the lower seating space of the workpiece seating portion 68 is formed to be inclined about 15 degrees, as shown in Figure 6, the tip of the punch-side pressure bar 74 is tapered protrusion 30 degrees Formed.

Accordingly, the work piece 42 seated on the work piece seating portion 68 of the die 66 of the second end 64 is lowered by the second step punch 72 of the multi-stage molding machine 2 to punch-side pressure bar ( Pressure punching to 74, a workpiece 44 is obtained, as shown in FIG. The die-side portion of both ends of the secondary preform material 44 is chamfered by about 15 degrees, and the punch-side portion has a recessed groove having an inner rim inclined by about 30 degrees. The die-side chamfering and punching-side tip recessed groove forming of the processed material 44 is for securing the fluidity of the metal structure of the material in a subsequent process.

(D) Process # 3

Process # 3 will be mainly described with reference to FIG. 7, which shows a concrete structure of a die and a punch mold corresponding to the third stage 76 of the multi-stage molding machine 2 according to the embodiment of the present invention.

The workpiece 44, which has undergone the # 2 process, is moved by a tong jig positioned between the second end 64 and the third end 76 of the multi-stage molding machine 2, whereby the workpiece seat of the third die 78 is processed. It is seated in the seating space of (80). A die pin 82 and a die-side sleeve 83 are slightly inserted and fixed in the seating space of the workpiece seating portion 80 in the lower portion of the workpiece seating portion 80.

The die-side operation chamber 90 is provided inside the die 78, and a compression spring 92 is fitted to the upper portion of the operation tool holder 93, and the die pin 82 is disposed in the compression spring 92. The die-side sleeve 83 is coupled and installed, and a die pin holder 94 and a fixing member 96 are stacked on the rear side to be fixed by bolts, and a stripping pin 98 for hitting the sleeve 124 is provided. The fixing member 96 and the die pin holder 94 penetrate the lower surface of the sleeve 83. In addition, the operating chamber 90 is located on the compression spring 92 and is limited by the locking jaw of the die 78 to be operable to be limited to the locking jaw of the die 78 from the upper surface of the operating tool bracket 93 An operating tool 81 is provided, and a workpiece mounting portion 80 is installed in the buffer operating tool 81. Thus, the shock absorber 81 can be operated by the elastic force of the compression spring 92 or the pressing of the punch 84 between the engaging jaw of the die 78 and the upper surface of the actuator support 93, which is a material The punch-side body of the die serves to extend the life of the die mold by extrusion molding into a pipe shape.

On the other hand, a punch-side operating chamber 100 is provided inside the punch 84, and each of the compression springs 102a and 102b is fitted into the corresponding guide rods 104a and 104b, and the guide rods 104a and 104b are placed. The tip of is extended to the punch side bracket 85 is fixed. The punch side bracket 85 is spaced apart from the punch 84 when the guide rods 104a and 104b are pushed forward, and is restored to its original state by the repulsive force of the compression springs 102a and 102b. . The punch pin 86 and the punch side sleeve 88 are attached to the punch 84, and the punch pin 86 is elongated compared with the punch side sleeve 88 for extruding the body into a pipe shape. .

Accordingly, the workpiece 46 seated on the workpiece mounting portion 80 of the third stage die 78 is lowered by the third stage punch 84 of the multi-stage molding machine 2 to be pressure punched with the punch pin 86. As a result, a workpiece 46 as shown in FIGS. 4 and 7 is obtained.

The punch 84 is operated to be retracted after press punching with the punch pin 86, but the guide rods 102a and 102b are controlled to maintain the current state. Accordingly, the bracket 85 and the punch side sleeve 88 fixed to the ends of the guide rods 102a and 102b support the outer circumferential surface of the raw material while maintaining the current state, but the punch pins inserted into the pipe-shaped processing grooves of the raw material ( 86 will retreat. As a result, the punch-side bracket 85 and the punch 84 are spaced apart to increase the resilience of the compression springs 102a and 102b, and the punch pin 86 is a pipe-shaped groove formed on the workpiece 86. Once completely out of the guide rods 104a and 104b are controlled to allow free movement so that the bracket 84 and punch side sleeve 88 are also retracted by the repulsive force of the compression springs 102a and 102b. The operation of the bracket 84 and the punch side sleeve 88 of the punch 84 as described above is inappropriate because the workpiece 46 is attracted to the pincher pin 86 when the punch pin 86 is ejected from the finished workpiece 46. To prevent it from falling off.

Thereafter, the die-side stripping pin 98 strikes the die-side sleeve 83, and the finished workpiece 46 is removed from the workpiece seat 80 of the shock absorber 81.

In the workpiece material 46 obtained by the above # 3 process, a generally shallow circular recess groove in which the die side portion is blocked is molded, and the punch-side body upper end portion is firstly extruded into a pipe shape. The material diameter at this time is related to the outer shape of the pipe shape and the basic shape of the hexagonal part forming in the subsequent process, and is for securing the fluidity (effectiveness of the metal structure flow) during processing.

(E) Process # 4

Process # 4 will be mainly described with reference to FIG. 8, which shows the concrete structure of the die and punch molds 112 and 138 corresponding to the fourth stage 110 of the multi-stage molding machine 2 according to the embodiment of the present invention.

The processed material 46 formed in step # 3 is moved by a tong jig positioned between the third end 76 and the fourth end 110 of the multi-stage molding machine 2 to process the workpiece of the fourth die 112. It is seated in the seating space of the seating portion 118. A hexagonal seating port for processing the outer shape of the workpiece into a hexagon nut shape is processed at the lower portion of the workpiece seat 118, and the tip of the die pin 124 is provided with a protrusion that is inclined by several degrees.

The die 112 of the fourth end 110 is mounted to the die block 116 by a die holder 114. An operating chamber 120 is provided inside the die 112 so that the compression spring 122 is placed therein, and the die side sleeve 126 and the die pin 124 are coupled to the compression spring 122, and the die The pin holder 128 and the fixing plate 130 are fastened and fixed using the fixing bolts 132. In addition, a processing oil outlet 136 communicating with the outside from the operation chamber 120 is formed in the die 112, and stripping pins 134a and 134b for hitting the sleeve 126 are fixed plate 130 and the die. It penetrates through the pin holder 128 and abuts against the bottom surface of the sleeve 126. On the other hand, the punch 138 is configured to include a punch pin 140.

Therefore, the workpiece 46 seated on the workpiece seat 118 of the die 112 of the fourth stage 110 is lowered to the fourth stage punch 138 of the multi-stage molding machine 2 to punch pin 140. When pressure punching in, a workpiece 48 is obtained, as shown in FIGS. 4 and 8.

In the processing material of the upper punch side by the # 4 process, the second extrusion of the material is performed by second extrusion to the trunk pipe shape first formed in the # 3 process by pressing the punch pin 140, and the lower die side In the workpiece material, the basic circular groove of the hole (pier piercing) is formed by the action of the die pin 124 at the same time as the hexagonal extrusion process, in the # 4 process is a combination of these three shape processing. Step # 4 is an extrusion process in consideration of the metal flow (metal flow).

(F) # 5 process

The process # 5 will be mainly described with reference to FIG. 9, which shows a concrete structure of a die and a punch mold corresponding to the fifth stage 150 of the multi-stage molding machine 2.

The work piece 46 formed in step # 3 is moved by a tong jig positioned between the fourth end 110 and the fifth end 150 of the multi-stage molding machine 2 to process the work piece of the fifth die 152. It is seated on the seating portion 154. Thereafter, the workpiece 48 seated on the workpiece mounting portion 154 of the fourth stage 150 is lowered to the punch side sleeve 164 by lowering the fifth stage punch 160 of the multi-stage molding machine 2. At the same time, pressing punching with the punch pin 162 results in hole piercing the middle portion of the inner diameter of the lower end of the raw material, and as shown in FIGS. 4 and 9, the shell nut finished product 50 is obtained. Thereafter, the punch 160 is retracted and the shell nut finished product 50 is knocked out using the die-side stripping pin 156 supported by the compression spring 158, and all the processes are completed.

As described above, one cycle of the shell nut manufacturing process using the multi-stage molding machine 2 is completed by the above processes. The time required for one cycle machining in each stage of the multi-stage molding machine 2 is about 1 second. Since the process according to the present invention undergoes five steps in the machine molding machine, If it is 1 second, it is 5 seconds in total but the machine is in continuous operation. It takes 5 seconds only at the start of work, and it is 1 second when continuous work is performed.

Table 1 below shows the comparison between the shell nut manufacturing method according to the prior art and the embodiment of the present invention.

As shown in Table 1 above, as compared to various items, the shell nut manufacturing method using the multi-stage molding machine of the present invention has a significant production cost reduction compared to conventional cutting, and thus, the product has a competitive edge in price. Will occupy.

In the above description of the present invention, specific embodiments such as shell nuts for automobiles have been described, but various modifications can be made without departing from the scope of the present invention. The mold process of the present invention can be applied to similar products in addition to shell nuts for automobiles. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, the present invention can make the shell nut to be a multi-stage molding machine at a time, thereby making the most of the advantages of the multi-stage molding machine. In addition, compared to the conventional cutting process can be achieved in all the items cost reduction production.

1 is a shell nut manufacturing process diagram manufactured by a cutting method according to the prior art,

Figure 2 is a side cross-sectional view of a general multi-stage molding machine for helping understanding of the present invention,

Figure 3 is a plan view capturing the working moment of the multi-stage molding machine for the understanding of the embodiment of the present invention,

Figure 4 is a view showing a shell nut manufacturing process by a multi-stage molding machine according to an embodiment of the present invention by process,

5 to 9 are concrete structural diagrams of die and punch dies corresponding to respective stages of the multi-stage molding machine 2 according to the embodiment of the present invention.

<< Explanation of symbols for main part of drawing >>

2: multi-stage molding machine 4: die side fixing part

6: punch-side drive part 10: die

12: punch 52: first stage

64: second stage 76: third stage

110: fourth stage 150: fifth stage

Claims (5)

In the shell nut manufacturing method using a multi-stage molding machine (2), A preliminary step of cutting the raw material for manufacturing in the cutting knife block 20 of the multi-stage molding machine 2 to obtain a cylindrical material 40; The cylindrical material 40 is transferred to the processing material seating portion 56 of the die 54 of the first end 52, inserted into the seating space, and seated to be supported by the die-side support rod 60, and the punch 58 A first process of moving to punch both end faces of the cylindrical material 40 to pressurize to obtain a first work material 42 having a top and bottom surface; The workpiece 42 is transferred upside down to the workpiece mounting portion 68 of the die 66 of the second end 64 so that the workpiece 42 is inserted and seated in the seating space, and the die-side supporting rods are provided on both sides of the workpiece 42. Pressing by using the 70 and the punch-side pressing rod 74, the recessed groove having an inner rim in which the punch-side portion of the both ends of the material is inclined dozens of degrees is formed and the die-side portion of the material than the inclination angle of the inner rim A second process of obtaining a second workpiece 44 chamfered at least with a low inclination angle, The second workpiece 44 is transferred to the workpiece mounting portion 80 of the die 78 of the third stage 76 to be inserted and seated in a seating space, and the second workpiece 44 is punched to a pin 86. And by pressing with the punch side sleeve 88, the die pin 83, and the die side sleeve 83, a shallow circular recess groove is formed in which the die side portion of the material is blocked, and the punch side portion is first extruded into a pipe shape. A third step of obtaining the molded third workpiece 46, The third workpiece 46 is transferred to the workpiece seat 118 of the die 112 of the fourth end 110 to be inserted and seated in the seating space, and the punch 138 is moved to punch pin 140 and Pressing both ends of the work piece 46 by using the die pin 124 and the die side sleeve 126, the punch side portion of the raw material is secondary molded by the second extrusion process, and the die side portion of the raw material is hexagonal A fourth step of obtaining a fourth processed material 48 having a shape of a base groove of perforation formed at the same time as the shape extrusion process, The fourth workpiece 48 is transferred to the die 152 of the fifth end 150 to be inserted and seated in the seating space of the workpiece mounting portion 154, and the punch pin 162 and the punch side sleeve 164 are placed. And a fifth step of obtaining the shell nut finished product (50) by pressing the fourth processed material (48) to perforate the inner diameter of the lower end of the material. The die-side portion of the second work piece 44 according to claim 1, wherein in the second step, the punch-side portion of both sides of the second work piece 44 is formed with a recessed groove having an inner rim inclined by 30 °. Shell nut manufacturing method characterized in that the 15 ° beveled to be inclined. In a shell nut manufacturing apparatus using a multi-stage molding machine (2): The multi-stage molding machine (2) is composed of a cutting knife block 20 and the first stage 52 to the fifth stage 150, each of the stage between the tongs for transferring the processed material from the previous stage to the subsequent stage A jig; The cutting knife block 20 of the multi-stage molding machine 2 cuts the raw material for manufacturing to form a cylindrical material 40, The first end 52 is a cylindrical material 40 which is conveyed to the workpiece mounting portion 56 of the die 54 of the first end 52 by a forceps to be supported by the die-side support rod 60. ) Is punched to move the punch 58 so that both end surfaces of the cylindrical material 40 are pressed, and is molded into a first work material 42 having a flat top and bottom surface, The second end 64 is formed to be inclined by 15 ° of the material seating lower surface edge of the workpiece mounting portion 68 of the die 66 of the second end 64, and the tip of the punch-side pressure rod 74 is The first workpiece is formed by a tapered protrusion of about 30 ° and is vertically inverted from the first end 52 to the workpiece seat portion 68 of the second end die 66 by a forceps jig. The second processed material 44 formed by pressing both surfaces of the material 42 to form a recessed groove having an inner rim in which the punch-side portion of the both ends of the material is inclined by about 30 ° and the die-side portion of the material to be inclined by 15 °. ), The third end 76 includes a shock absorbing operation 81 provided with a workpiece mounting portion 80 in the operating chamber 90 of the die 78, and the second end 64 is provided by a forceps. Punch pin 86 and punch side sleeve 88, die pin 83, and die side of the second workpiece 44 transferred to the workpiece seat 80 of the third stage die 78 from The die side of the material is formed by pressing the sleeve 83 to form a shallow circular concave groove which is blocked, and the punch side is formed of a third workpiece 46 which is first extruded in a pipe shape. The fourth end 110 is a punch pin by moving the punch 138 to the third workpiece (46) transported and seated on the workpiece seat 118 of the fourth stage die 112 by a forceps jig. Pressing both ends of the workpiece (46) using the die 140 and the die pin 124 and the die-side sleeve 126, the punch side of the material of the body pipe is secondary molded by secondary extrusion processing The die side is molded into the fourth processing material 48 which forms the basic groove of perforation at the same time as the hexagonal extrusion process, The fifth end 150 is a punch pin 162 and a punch side sleeve for the fourth workpiece 48, which is transported and seated to the workpiece mounting portion 154 of the fifth stage die 152 by a forceps jig. Shell nut manufacturing apparatus characterized in that configured to obtain a shell nut finished product (50) by pressing by pressing the inner diameter of the lower end of the hexagonal portion (164). The shell nut according to claim 3, wherein a hexagonal seating hole for processing the outer shape of the workpiece into a hexagonal shape is machined in a lower portion of the workpiece seating portion 118 of the fourth die 112. Manufacturing equipment. The method of claim 3, wherein the third end 76 is provided with a punch-side operating chamber 100 inside the punch 84, the compression chamber (102a, 102b) is guided to the operating chamber 100, respectively; The rods 104a and 104b are placed and settled, and the tip ends of the guide rods 104a and 104b extend to the punch side bracket 85 to which the punch pin 86 and the punch side sleeve 88 are coupled. Shell nut manufacturing apparatus, characterized in that the body punch pin 86 to maintain the pressure support to the punch-side sleeve 88 when retracting from the pipe-shaped processing groove so that the third processing material 46 is not improperly released .