WO1998009749A1 - Method of fabricating shaft from metal plate - Google Patents

Abstract

A shaft is integrally fabricated from an arbitrary portion of a metal plate, the axis of which is perpendicular to the metal plate. The method comprises a first step of extruding the metal plate (1) forward by press working, and a second step of subjecting a projecting portion, which is formed by the first step, to rearward extrusion with a punch inserted forcibly thereinto so as to expand it longitudinally. A shaft with a sufficient height is fabricated with a high precision.

Description

 Specification

Title of the invention Shaft forming method from metal plate

Technical field ~

 The present invention relates to a method for forming a shaft from a metal plate rather than a metal plate.

Background art

 In recent years, when a shaft is provided on a metal plate, a shaft processed in a separate process has been fixed to the metal plate by caulking or spot welding to the metal plate.

Hereinafter, a conventional method for forming a metal plate on a metal plate will be described.

 FIG. 17 is a diagram showing a conventional method of forming a shaft on a metal plate by caulking and fixing. A hole is machined in the metal plate 10 on which the shaft 11 is to be installed, and the Yukiyoshi 11 machined in another process is fixed by caulking. Fig. 18 shows a conventional method of forming a shaft on a metal plate by spot welding. The shaft 13 processed in another process is spot-welded to the metal plate 12 on which the shaft 13 is to be installed.

 In addition, as shown in Fig. 19, Japanese Patent Publication No. 6-267673 discloses that a plate 21 is pressed from one side by a first tool 22 to form a hole on one side and a projecting part on the other side, as shown in FIG. After forming 24, the lower surface 23a of the second tool 23 is brought into contact with the hole side, and by pressing, the amount of oil in the pressed portion is moved to the projecting portion to further project the projecting portion 24. A forming method is described in which the first tool 24 is protruded, and the first tool 24 is pressed again to add height to the protruding portion 24 to form a cross portion.

 Further, as a method of forming a shaft-like object, a front extrusion method shown in FIG. 20 and a rear extrusion method shown in FIG. 21 are known.

 However, the conventional method of forming a shaft by crimping or spot welding as described above increases the cost because the shaft is processed in a separate process and then fixed to a metal plate. Also, when caulking is fixed, it is difficult to deform the metal plate due to the caulking pressure, and it is difficult to obtain the perpendicularity between the metal plate and the shaft.In spot welding, the welding area is small, so sufficient strength can be obtained. There was no problem.

In addition, in the method described in Japanese Patent Publication No. 6-26773, the pressing force of the tool always acts on the boundary between the plate and the protrusion, and it is difficult to secure a sufficient height of the protrusion. And In particular, it is difficult to obtain the perpendicularity of the protruding portion with respect to the plate material and the accuracy of the outer diameter, and there is a problem that a large number of steps are required in addition.

 In both forward extrusion and backward extrusion, the pellet material is processed to form a deformed material by processing the pellet material. Absent.

Disclosure of the invention

 The present invention solves the above-mentioned conventional problems, and includes a first step of half-punching a metal plate by pressing or extruding forward, and a metal plate obtained by the first step and held by a die. A second step of pushing a punch into the projecting portion of the metal plate and pushing the projecting portion backward in a direction opposite to the pushing of the punch, thereby extending the projecting portion in an axial shape. It is a forming method.

 In addition, the present invention is characterized in that a plurality of shafts having the same height are collectively formed.

 Further, the present invention provides that, in the second step, the progressive processing is performed such that the direction in which the protruding portion is elongated to form the shaft and the direction in which the metal plate is punched in the other step are opposite to each other. It is a feature.

 With the above configuration, the metal plate is extruded forward by press working to form a protruding part, and then this protruding part is extruded rearward by a punch and die to form a shaft. Further, it is possible to form a shaft having a sufficient perpendicularity or the like at an arbitrary position on the metal plate from the metal plate integrally and with a small number of steps.

 In addition, by forming a plurality of shafts of the same height collectively at a plurality of cylinders, a plurality of shafts of the same height can be extended by the backward extrusion process in the second step, and when the metal plate rises from the die surface, However, it is possible to prevent variations in the amount of lifting and tilting of the metal plate.

Further, in the second step, the direction in which the shaft is extended and the direction in which the metal plate is punched in the other steps are opposite to each other, so that the rearward extrusion of the metal plate in the progressive processing is performed. At this time, there is no gap between the die surface and the metal plate, and punching in other processes becomes difficult. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a view showing a state before a first step in a method for forming a shaft from a metal plate according to one embodiment of the present invention.

 FIG. 2 is a view showing a state in which a projection is formed in the first step.

 FIG. 3 is a view showing a relationship between a punch, a die, and a metal plate in the second step. FIG. 4 is a view showing a state after completion of the second step.

 FIG. 5 (a) is a diagram showing the volume of the protrusion.

 (b) is a diagram showing the volume of the shaft.

 FIG. 6 is a diagram showing the relationship between the punch-in amount and the escape rate of the SPCC material. FIG. 7 is a diagram showing the relationship between the punch-in amount and the escape ratio of the high-tensile steel material. FIG. 4 is a diagram showing the relationship between the outer diameter of the protrusion of the metal plate and the inner diameter of the die.

 FIG. 9 is a diagram showing the relationship between the height of the projecting portion of the metal plate and the depth of the die.

 FIG. 10 is a diagram showing a dimensional relationship between a punch and a die in a first step. FIG. 11 is a diagram showing a relationship between a punch press-in amount and a protrusion height in a first step.

 FIG. 12 is a diagram showing a dimensional relationship between a punch and a die in the second step. FIG. 13 is a diagram showing the amount of pushing of the punch in the second step.

 FIG. 14 is a diagram showing the dimensions of the shaft after the completion of machining.

 FIG. 15 (a) is an explanatory diagram in the case where the direction of elongation of the shaft in progressive feeding is the same as the punching direction of another process.

 (b) is an explanatory view in the case where the direction of elongation of the shaft in progressive feeding and the punching direction of another process are opposite.

 FIG. 16 is a diagram showing a processing state of a stepped shaft.

 FIG. 17 is a diagram showing a conventional method of installing a shaft by caulking.

 FIG. 18 is a diagram showing a conventional method of installing a shaft by spot welding.

 FIG. 19 is a view showing a conventional shaft forming method according to a known example.

FIG. 20 is an explanatory diagram of front extrusion. FIG. 21 is an explanatory view of the rear extrusion process.

BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, examples of the present invention will be described with reference to the drawings.

 In Fig. 1, 1 is a metal plate whose shaft is to be protruded, and 2 is a case where a metal plate 1 is half-punched or a front extrusion is performed to move the material in the same direction as the moving direction of the punch 2 by pressing. Die used when punching half-punch or forward extrusion of metal plate 1 together with punch 2 by press, and 4 shown in Fig. 2 is protrusion of metal plate 1 obtained by half-punching or front extrusion 3 is a punch used to extrude the material of the protruding portion 4 backward, 6 is a die used together with the punch 5 to extrude the protruding portion 4 rearward, and 7 shown in FIG. This is a shaft that has been extruded and integrated with the metal plate 1.

 The step of processing the shaft configured as described above and integrated with the metal plate 1 will be described. First, a material having a volume necessary for forming the shaft 7 is half-punched or extruded forward by a press using the punch 2. Next, the projecting portion 4 of the metal plate 1 half-punched or extruded forward is compressed by a punch 5 and a die 6, and extruded rearward to process a shaft 7. At this time, the material of the protruding portion 4 is replaced by the shaft 7 and extends in the moving direction of the shaft 7 force punch 5, so that the metal plate 1 rises above the upper surface of the die 6 as shown in FIG.

 In the above series of steps, first, in the front extrusion step of the first step, as shown in Figs. 5 (a) and (b), it is necessary to protrude the volume of material necessary for shaft forming by front extrusion. is there. This front extrusion process uses a die with the same diameter as the pin diameter, and determines the punch diameter and the amount of indentation according to the pin height. At this time, when the pin height is low, the diameter of the punch and the die may be the same because the volume to be protruded by the front extrusion is small. This is because the projected volume is the same as the volume pushed by the punch. The higher the pin, the larger the protruding volume, so a punch with a large die diameter must be used.

However, the amount pushed by the punch at this time does not directly become the protrusion amount. Material escape always occurs. Fig. 6 shows the amount of material escape in the case of SPCC material with t = 1.2, and Fig. 7 shows the amount of material escape in the case of high-strength steel with t = 0.8. The die diameter is 2 You. Fig. 6 shows that the larger the punch diameter, the greater the amount of material escape. When the number of punches becomes 4, it can be seen that about half of the material pushed in has escaped to the surroundings. Also, when looking at the same punch diameter, the larger the amount pushed in, the less material escapes.

 Based on these data, the punch diameter and the amount of indentation required for pin forming are determined.

 Next, the protrusion 7 of the material obtained by the front extrusion is fitted into the die 6, and the shaft 7 is formed by rear extrusion in which the material is crushed by the punch 5.

 At this time, since the diameter of the die 6 must be the same as the diameter of the shaft 7, the diameter A of the material protrusion 4 is set as shown in FIG. 8 so that the material protrusion 4 easily fits into the die 6. It is better to make it smaller than the diameter B of the die 6. In the initial experiment, the diameter of the protruding part was smaller by 0.011 in diameter than the die diameter of the rear extrusion. However, this setting is not suitable for the progressive type, because it requires power to enter the die. Next, when a protruding part with a diameter of 0.05 mm was manufactured, an experiment was performed. As a result, it could be smoothly inserted into the die. Therefore, when forming a pin in a progressive die, the die diameter of the front extrusion should be smaller than the diameter of the boss by 0.01 or more, up to about 0.1 mm, and optimally smaller by 0.05 mm. It is important to set.

 The point of this backward extrusion is that the tip of the punch must be tapered to make the material flow smooth.

 Also, do not hold the material with the stripper plate because the metal plate rises above the top surface of the die.

 Furthermore, when the protrusion 4 of the metal plate 1 is fitted into the die 6, if there is a gap between the upper surface of the die 6 and the metal plate, a step is formed at the root of the shaft, and as shown in FIG. The depth should be 0.05 to 0.1 mm deeper than the height of the protruding part of the material.

 As a specific example, a metal plate 1 was machined from a SPCC material having a thickness t = 1.2 with a diameter of 1.99 mm and a height of 3.4 mm.

At that time, Kai d ₂ of the punch 2 used in the forward extrusion shown in the first 0 Figure "!> 3.0 noodles, the inside diameter d ₃ of the die 3 ų 1. 9 4誦, also a result of the forward extrusion The dimensions of each part of the material in Fig. 11 including the formed protrusions 4 are such that the punching amount h is 1.0 mm, The diameter A of the part 4 is ^ 1.93MI and the height h4 is 1.87.

Furthermore, in the backward extrusion process of the projecting portion 4, the diameter d ₅ of the punch 5 as shown in the first Fig. 2 ^ 1. 4 mm, inner diameter d ₆ of the die 6 ų 1. 99 Jour, the depth of the die 6 h ₆ 1. 90 mm. the push-in amount h ₅ of the punch 5 as shown in the first 3 FIG 1. is a 6 5 Jour.

The dimensions of the shaft 7 units shown in the first 4 diagram obtained above results, the thickness t is 1.2 noodles, the height h 7 3. 3 6 7~3. 4 32m, the diameter d ₇ is ^ 1 983 ~ 1.992I I, the height and diameter variation are 0.07I I and 0.01 respectively, and the tip of the shaft is 0.000 ~ 0.05.

 Also, the points for raising the height of the shaft are front extrusion, which is to protrude a lot of material and to reduce the thickness of the side wall of the pin. The result of confirming the height limit is shown below.

 1 = 1.2 SPC C material is used, and the punch diameter of the front extrusion is ^) 4 This is because when using a 5-hide method, the material escapes considerably, causing the material to bulge at the base of the protrusion. Also, if the experiment was performed with the side wall of the pin at 0.1 mm, the pin was broken from the root due to insufficient strength, so it was a 0.2 band. As a result, the pin height was 5.95 mm.

 Through the above examples, the following items were grasped.

 In other words, regarding the fall of the pin, in the experiment conducted this time, the axis of 02 satsu was formed on a flat plate of 40 satsu X 40 seki, so there was no big fall, but in the case of a wide material, the rear extrusion was not performed. When the material is lifted up, the pin may fall down. For this reason, it is necessary to arrange 铀 in several places and to jump up the material in a well-balanced manner.

Also, in the backward extrusion process, the material jumps up at the time of the backward extrusion, but this differs depending on the height of the shaft and the amount of the jump. Therefore, in the same process of rear extrusion, only the same shaft height can be formed. In this process, other processing (punching, bending, etc.) cannot be performed, and it is better that there is no pilot that obstructs the material from jumping. Furthermore, when the backward extrusion process is performed in a progressive type, the direction of the shaft is restricted. When molding the downward shaft 30 as shown in Fig. 15 (a), the material 31 jumps up, creating a gap between the die surface 32 and the material 31. During processing, the material 31 will bend. Conversely, when forming the shaft 34 upward, as shown in Fig. 15 (b), the material 31 is pushed downward, so that there is no gap between the die surface 32 and the material 31; In the process 35, the punching process becomes difficult.

 In addition, it is also possible to form a shaft having a step 40 as shown in FIG. 16 by performing additional processing on the shaft 7 formed in this embodiment.

Industrial applicability

 As described above, according to the present invention, a metal plate is subjected to forward extrusion by press working to form a protruding portion, and then the protruding portion is rearward extruded by a punch and a die to form a shaft. An excellent effect is achieved in that an axis with sufficient outer diameter accuracy, perpendicularity, etc. can be formed at an arbitrary position on the metal plate from the metal plate integrally and with a small number of steps. .

 In addition, by forming a plurality of shafts of the same height together, a plurality of shafts of the same height can be extended by the rear extrusion process in the second step, so that the metal plate can be lifted from the die surface. However, it is possible to prevent variations in the amount of lifting and tilting of the metal plate.

 Further, in the second step, the direction in which the shaft is extended and the direction in which the metal plate is punched in the other steps are opposite to each other, so that the rearward extrusion of the metal plate in the progressive processing is performed. At this time, there is no gap between the die surface and the metal plate, and punching in other processes becomes difficult.

Claims

The scope of the claims  1. a first step of half-punching or forward extrusion of a metal plate by pressing, and pressing a punch into a protrusion of the metal plate obtained by the first step and held by a die, thereby forming the protrusion. A second step of extruding the shaft in an axial direction by extruding the same in a direction opposite to the pushing of the punch.  2. The method according to claim 1, wherein in the second step, the inner diameter of the die holding the protrusion is set to be larger than the outer diameter of the protrusion in a range from 0.01 mm to 0.1 band. A method of forming a shaft from a metal plate.  3. The shaft forming from a metal plate according to claim 1, wherein the depth of the die holding the protrusion in the second step is set to be 0.05-0.1 mm deeper than the height of the protrusion. Method.  4. The method for forming a shaft from a metal plate according to claim 1, wherein in the second step, the protruding portion is pushed backward by using a punch having a tapered tip.  5. The method for forming a shaft from a metal plate according to claim 1, wherein a plurality of shafts having the same height are collectively formed.  6. In the second step, the projecting portion is elongated, and the progressive forming process is performed by setting the direction in which the shaft is formed and the direction in which the metal plate is punched in the other steps to be opposite to each other. Item 6. The method for forming a shaft from a metal plate according to Item 1.