Parts with edges on both sides of a flat plate and manufacturing method thereof

Abstract

To provide a manufacturing method for manufacturing a component, which has upper and lower edges extended in opposite directions from the same position of a flat plate, by press molding, and the component.SOLUTION: A manufacturing method for a component having both edged surfaces of a flat plate includes: a drawing step of drawing the flat plate into a shape having the flat plate and an edge; a forging pressure step of making a projection on the other surface different from one edged surface of the flat plate; and an ironing step of setting the edge and the projection flush with each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a part having edges on both sides of a flat plate and a method for manufacturing the part, and more particularly to a part having edges on both sides of a flat plate used in automobiles and the like and a method for manufacturing the part. [Background technology]

[0002] Conventionally, a part 9 as shown in Fig. 1(a) has been used in automobiles and the like. Fig. 1(a) is a perspective view of the part 9. Fig. 1(b) shows a cross-sectional view of the part 9. The surface of the flat plate 10 has an upper edge 11a and a lower edge 11b, and both sides of the flat plate 10 are recessed. When manufacturing the component 9, it is preferable from the viewpoint of cost to manufacture it by press molding, which makes it possible to manufacture a component having sufficient strength in a short time (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-41264 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional press molding, it is not possible to form the upper edge 11a and the lower edge 11b that extend in opposite directions from the same position on the flat plate 10. Therefore, an object of the present invention is to provide a method for producing a part by press molding, which has an upper edge 11a and a lower edge 11b extending in opposite directions from the same position on a flat plate 10, and to provide the part. [Means for solving the problem]

[0005] In order to achieve the above object, a method for manufacturing a part having edges on both sides of a flat plate is used, which includes a drawing process for drawing a flat plate into a shape with a flat plate and an edge, a forging process for forging and pressing to create a protrusion on the other side of the flat plate that is different from the side on which the edge is located, and an ironing process for making the edge and the protrusion into the same surface.

[0006] Also, a part having edges on both sides of a flat plate is used, in which the radius of the inner surface between the flat plate and the edges is a curved surface consisting of two radii of different sizes. Furthermore, a part having edges on both sides of a flat plate, in which the hardness of one edge is 1.3 times or more greater than the hardness of the other edge, is used. [Effects of the Invention]

[0007] According to the method for manufacturing a part having edges on both sides of a flat plate of the present invention, a part having edges on both sides of a flat plate can be manufactured mainly by press molding. Furthermore, the part having edges on both sides of a flat plate of the present invention is a part with high hardness or no wrinkles. [Brief explanation of the drawings]

[0008] [Figure 1] (a) Perspective view of a conventional part, (b) Cross-sectional view of a conventional part [Figure 2] (a) to (d) are perspective views of the process of the embodiment at each stage. [Figure 3] (a) to (d) are cross-sectional views of the process of the embodiment at each stage. [Figure 4] Enlarged cross-sectional view of an example of a forging process according to an embodiment. [Figure 5] (a) to (b) are cross-sectional views of a comparative example in a forging process, and (c) to (d) are cross-sectional views of an embodiment in a forging process. [Figure 6] (a) to (g) are cross-sectional views of the process of the embodiment at each stage. [Figure 7] 10A and 10B are cross-sectional views illustrating changes in the ironing process according to the embodiment. [Figure 8] (a) to (c) are cross-sectional views illustrating the forging process in the embodiment. [Figure 9]1 is a cross-sectional view showing measurement points of hardness of a part according to an embodiment of the present invention; [Figure 10] Cross-sectional view of a component according to an embodiment DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. This is an example of manufacturing a part 19. The following is an example of the present invention, and the present invention is not limited to only the following example. (Embodiment) <Manufacturing method, process> The manufacturing process of the embodiment will be explained with reference to Figures 2(a) to 3(d). The part 19 is manufactured mainly by press molding. 2(a) to 2(d) are perspective views of each stage of the process. 3(a) to 3(d) are cross-sectional views at each stage of the process.

[0010] (1) Blanking process 2(a) and 3(a) is prepared. The plate material 12 is produced by punching out a large-area plate or the like.

[0011] (2) Drawing process As shown in FIG. 2(b) and FIG. 3(b), the plate material 12 is drawn into a bowl shape and a dish shape. Drawing is performed using a pair of dies: a die (lower die) with a recess that conforms to the shape of the product, and a punch (upper die) that sinks into the die. First, a blank holder presses the sheet material 12 onto the die, and then the punch descends, applying pressure to the sheet material 12, causing the sheet material 12 to deform according to the shape of the bottom end of the punch and be forced into the hole in the die. As the punch continues to descend, the peripheral portion of the sheet material 12 that was being held down by the blank holder is pulled into the hole in the die. The result is shown in Figures 2(b) and 3(b).

[0012] At this time, compressive strain occurs in the plate material 12, causing wrinkles to form in the upper part of the tube, but these wrinkles are suppressed by the wrinkle suppression plate.

[0013] (3) Forging process As shown in FIG. 2(c) and FIG. 3(c), a forging process is carried out to provide the protrusions 20. Cold forging is used as the forging pressure. Cold forging is a processing method in which pressure is applied to the material (metal) at room temperature without adding heat, deforming the metal and forming it. Since it makes use of the metal's plasticity, it is also called "plastic processing."

[0014] In cold forging, metal is deformed during processing, so almost no shavings (metal waste) are generated during the manufacturing process. In addition, since the material is processed at room temperature without heating, dimensional accuracy is good, and even complex shapes can be processed at high speeds of around 100 pieces per minute. The forging process can also be performed at a higher temperature.

[0015] (4) Squeezing process As shown in FIG. 2(d) and FIG. 3(d), an ironing process is carried out to produce a part 19. In the ironing process, the wall surface of the product is ironed vertically with a punch to make it uniform in thickness, which also increases the depth (height) of the product (increases the length of the upper edge 11a).

[0016] The plate material 12 may be made of, for example, S35C (carbon steel for machine structures) or SPFH590 (high-tensile steel plate). Other metals used in press forming may also be used. The same phenomenon occurs. The thickness of the plate material 12 may be any thickness that allows press molding, for example, 1 to 5 mm.

[0017] The component 19 has edges 11 (upper edge 11a and lower edge 11b) on both sides of the flat plate 10. The edges 11 do not necessarily extend around the entire periphery of the flat plate 10, but may extend along only a portion of the periphery. Furthermore, the flat plate 10 does not have to be circular, and may be elliptical or rectangular. Actual parts 19 are used for pulleys, gears, cams, etc. In some cases, it may be necessary to form irregularities on the outer periphery of the edge 11. In such cases, the outside of the edge 11 shown in Figures 2(d) and 3(d) is formed. <Position of protrusion 20> FIG. 4 shows an enlarged cross-sectional view of the end of part 19. Protrusion 20 is located between (at the boundary between) flat plate 10 and edge 11. Preferably, it is located at the end of flat plate 10. Edge 11 does not directly become protrusion 20, but protrusion 20 is generated from a part of flat plate 10. A flow of material occurs from edge 11 and flat plate 10. As a result, protrusion 20 with high hardness can be formed. Note that protrusion 20 must be located at least on flat plate 10.

[0018] <Effects> By press forming (drawing process, forging process), it is possible to manufacture a part 19 having edges 11 on both sides of a flat plate 10. Furthermore, it can be manufactured with a low forming load (described below).

[0019] <About the forging process> 5(a) to 5(d) are cross-sectional views showing several examples of the forging process, in which only one edge 11 is shown.

[0020] (1) Comparative Example 1 5(a), after the drawing step, the plate material 12 is clamped and fixed between a die 13 and a pad 14, and the edge portion 11 is deformed with a punch 15. As a result, an upper edge 11a and a lower edge 11b are formed.

[0021] (2) Comparative Example 2 In FIG. 5(b), after the drawing process, the sheet material 12 is clamped and fixed between a die 13 and a pad 14, and the edge portion 11 is deformed with a punch 15. In this case, the edge of the edge portion 11 is pressed with the punch 15, and the sheet material 12 is deformed in two opposite directions from one position. Then, although not shown in the figure, the sides of the upper edge 11a and the lower edge 11b are cut (ironing process). As a result, the upper edge 11a and the lower edge 11b are produced.

[0022] (3) Example 1 In FIG. 5(c), after the drawing process, the sheet material 12 is clamped and fixed between a die 13 and a pad 14, and the edge portion 11 is deformed with a punch 15. In this case, a protrusion 20 is formed in a direction that differs from the edge portion 11 by approximately 90 degrees. Then, in the ironing process, an upper edge 11a and a lower edge 11b are formed. As a result, the upper edge 11a and the lower edge 11b are formed. Note that the direction of the protrusion 20 may be in a direction that is greater than 45 degrees and less than 180 degrees from the edge portion 11.

[0023] (4) Example 2 In FIG. 5(d), after the drawing process, the sheet material 12 is clamped and fixed between a die 13 and a pad 14, and the edge portion is deformed with a punch 15. In this case, a protrusion 20 is formed in a direction parallel to the edge portion 11. Then, in the ironing process (explained in FIGS. 6(d) to 6(g)), the side surfaces are made flush, and an upper edge 11a and a lower edge 11b are formed. As a result, an upper edge 11a and a lower edge 11b are formed.

[0024] The forming load required for each forging process is shown in Table 1. The material of the plate material 12 is S35C (carbon steel for machine structures) or SPFH590 (high-tensile steel plate), and these are the forming loads required when the punch 15 speed is 100 mm / sec. These are the conditions for normal production. Note that the forging process has a larger forming load than the other processes.

[0025] [Table 1]

[0026] In both examples, an upper edge 11a and a lower edge 11b are produced. However, as can be seen from Table 1, comparative examples 1 and 2 require a large forming load and a special press. In both comparative examples 1 and 2, the edge 11 is significantly deformed, so a large forming load is required.

[0027] On the other hand, in Examples 1 and 2, the forming load is preferably 500 t or less. In Example 1, the middle edge 11c is significantly deformed in the ironing process, which may cause wrinkles, etc. Therefore, Example 2 is preferable to Example 1.

[0028] <Squeezing process> 6(a) to 6(g) show an example in which the ironing process is performed multiple times. 6(a) to 6(c) are the same as FIGS. 3(a) to 3(c), respectively. In Figures 3(c) to 3(d), the ironing process was performed once, whereas in this example, the ironing process was performed four times as shown in Figures 6(d) to 6(g).

[0029] An enlarged cross-sectional view is shown in Figure 7. It is preferable to start by squeezing hard and then gradually reduce the amount of squeezing. The upper edge 11a becomes longer with each squeezing. If the ironing process is done in one go, dents are likely to form on the surface. On the other hand, if the ironing process is done multiple times with gradual changes as in this example, dents will not form. As a result, it is preferable to perform the ironing process multiple times.

[0030] The number of times of the ironing process does not have to be four. In this case, the total deformation amount is about 5 mm. The thickness is 3 mm, but the deformation amount is 5 mm, which is a large change. The deformation amount needs to be equal to or greater than the plate thickness of the lower edge 11b. <Surface of the side> By repeating the above-mentioned ironing process multiple times, the maximum irregularity on the outer side surface of the edge 11 becomes 0.07 mm or less. When the ironing process is performed only once, the maximum irregularity is 0.26 mm. By performing the ironing process multiple times, the maximum irregularity becomes at least 0.10 mm or less. <About the drawing process and forging process> FIG. 8(a) shows an enlarged cross-sectional view of the end of the part 19 after the forging process and the die 13 (during the drawing process and forging process).

[0031] 8(b) shows an enlarged cross-sectional view of the die 13 according to Example 3, and FIG. 8(c) shows an enlarged cross-sectional view of the die 13 according to Example 4. The die 13 according to Example 3 has a curved surface between the flat plate 10 and the lower edge 11b with a single radius (single R). On the other hand, the die 13 according to Example 4 has two different radii (different sizes) (double R).

[0032] When the die 13 of Example 3 is used for the drawing and forging processes, wrinkles may occur on the inner surface of the manufactured part 9. This is thought to be due to the difference in deformation between the flat plate 10 and the edge 11 of the part 19.

[0033] On the other hand, when the drawing process and forging process are performed using the die 13 of Example 4, wrinkles are less likely to occur on the inner surface of the manufactured part 19. This is thought to be because the difference in deformation between the flat plate 10 and the edge 11 of the part 19 is alleviated.

[0034] In Example 3, since the curve is single R, the meat tends to flow easily when deformed, and wrinkles tend to form. On the other hand, in Example 4, since the curve is double R, the meat tends to flow less easily when deformed, and wrinkles do not form. Example 4 is preferable to Example 3.

[0035] <About hardness> The hardness of the produced part 19 was measured. The locations where the hardness was measured are shown in Figure 9. Figure 9 is an enlarged cross-sectional view of the end of part 19. The measurement locations are indicated by numbers in Figure 9. The measurement results are shown in Table 2.

[0036] [Table 2]

[0037] The hardness was measured using a Vickers hardness tester. The measurement conditions were a test force of 5 kgf and a test force holding time of 5 seconds. Part 19 was produced by the method of Example 2. The material used was SAPH440, with a thickness of 3 mm, and was produced at a punch speed of 100 mm / sec.

[0038] The hardness of the upper edge 11a is about twice as high as that of the other portions. The hardness of the blank (material) plate material 12 is 150 HV. It is thought that the protrusions 20 (see FIG. 3(c) and the like) protruded from the flat plate 10, causing the flow (meat flow) to extend in a U-shape, resulting in an increase in hardness.

[0039] The hardness of the upper edge 11a is 1.5 times or more, at least 1.3 times or more, greater than that of the other portions (lower edge 11b, flat plate 10, corners). Moreover, the edge is 1.2 times, or at least 1.1 times harder than the flat plate 10 . <Inner groove> 10 shows an example of a part 19 produced by the above-described method. The dotted line indicates the upper edge 11a that has been lengthened by the ironing process. The dotted line corresponds to the dotted line in FIG. A groove 30 may appear inside the upper edge 11a. This groove 30 is thought to be the boundary between the part that has grown during the ironing process and the part that was there originally. The grooves 30 are grooves that extend in a direction parallel to the flat plate 10. The presence of the grooves 30 provides directionality and makes the upper edge 11a firm.

[0040] <Post-processing> The part 19 may be left as is, or may be processed differently depending on the application. If the outer side of edge 11 is made uneven, it becomes a timing pulley. A pulley is a disc-shaped part that transmits power received from a belt to a shaft. There are several types of pulleys to suit the shape of the belt, including V-pulleys and timing pulleys. Because pulleys are parts that rotate at high speeds, careful attention is paid to balancing accuracy. They are used in a variety of machines that use rotational power, including high-speed pumps and compressors, as well as generators. There are also pulleys that can accommodate multiple belts to transmit stronger power. Furthermore, it can also be applied to gears, cams, etc. [Industrial Applicability]

[0041] It can be widely used as a part for transmitting force, not only in automobiles but also in many other moving machines and devices. [Explanation of symbols]

[0042] 9 parts 9a Upper edge 9b Lower edge 10 flat plate 11. Edge 11a Upper edge 11b Lower edge 12 Board material 13 Die 14 pads 15 punch 19 parts 20 protrusions

Claims

1. a drawing process for drawing the flat plate into a shape with a flat plate and an edge; a forging step of forming a protrusion on the other surface of the flat plate different from the surface on which the edge is located; and an ironing step for making the edge and the protrusion flush with each other.

2. 2. The method for manufacturing a part having edges on both sides of a flat plate according to claim 1, wherein the protrusions formed in the forging step are perpendicular to the edges.

3. 2. The method for manufacturing a part having edges on both sides of a flat plate according to claim 1, wherein the protrusions formed in the forging step are parallel to the edges.

4. 4. The method for manufacturing a part having edges on both sides of a flat plate according to claim 3, wherein the protrusions formed in the forging step are located at the boundary between the edges and the flat plate.

5. The method for manufacturing a part having edges on both sides of a flat plate according to any one of claims 1 to 4, wherein the ironing step is carried out a plurality of times.

6. 6. The method for manufacturing a flat plate having edges on both sides thereof according to claim 5, wherein the amount of ironing is gradually reduced during the multiple ironing steps.

7. 7. A method for manufacturing a part having edges on both sides of a flat plate according to claim 1, wherein in the die in the drawing process, the surface of the portion corresponding to the curved surface between the flat plate and the edge has two different radii of different sizes for the curved surface between the flat plate and the edge.

8. A part having edges on both sides of a flat plate, wherein one curved surface on the inner surface between the flat plate and the edge is made up of circles of two different radii in a plane parallel to the flat surface.

9. A part having edges on both sides of a flat plate, the hardness of one edge being 1.3 times or more greater than the hardness of the other edge, The hardness of the component is a Vickers hardness.

10. A part having edges on both sides of a flat plate, the edges having grooves on the inner side surfaces of the edges that run parallel to the flat plate. End

Images