Stabilizer manufacturing method and base material

Abstract

To provide a stabilizer manufacturing method capable of suppressing reduction in flatness at both ends of a stabilizer, and a base material.SOLUTION: This stabilizer manufacturing method for executing a forging process for a base material to manufacture a stabilizer having through-holes at both ends comprises: a projected part forming step of forming projected parts at through-hole forming positions of the ends of the base material corresponding to the through-holes of the stabilizer; and a through-hole forming step of forming through-holes at the through-hole forming positions including the projected parts.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a stabilizer and a base material. [Background technology]

[0002] A stabilizer used in a vehicle or the like is attached to the vehicle to stabilize the vehicle's posture. The stabilizer is formed, for example, by deforming a solid or hollow rod-shaped member (see, for example, Patent Documents 1 and 2). The stabilizer has both ends connected to the vehicle, and the connecting portions are flat. After the rod-shaped member is crushed into a flat plate at the end of the stabilizer, a through-hole is formed in the end of the stabilizer, through which a fastening member such as a bolt is inserted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 63-273541 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-320343 Summary of the Invention [Problem to be solved by the invention]

[0004] The through-holes at the end of the stabilizer are formed by punching the end with a punching member. In this case, friction and other factors generated during punching can cause deformation around the through-hole, resulting in the formation of so-called sagging. The formation of sagging can reduce the flatness of the end, potentially reducing the fastening strength between the vehicle and the stabilizer by the fastening member.

[0005] The present invention has been made in view of the above, and has an object to provide a method for manufacturing a stabilizer and a base material that can suppress a decrease in flatness at both ends of the stabilizer. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objective, the manufacturing method of the stabilizer of the present invention is a manufacturing method of a stabilizer in which a base material is forged to produce a stabilizer having through holes formed at both ends, and is characterized by including a convex portion forming step of forming a convex portion at the end of the base material at a through hole forming position corresponding to the through hole in the stabilizer, and a through hole forming step of forming a through hole at the through hole forming position including the convex portion.

[0007] Moreover, in the method for manufacturing a stabilizer according to the present invention, in the above invention, the convex portion forming step forms the convex portion while flattening the end portion of the base material.

[0008] In addition, the method for manufacturing a stabilizer according to the present invention is characterized in that, in the above invention, it further includes a heating step of heating an end portion of the base material, and the convex portion forming step forms the convex portion on the end portion heated by the heating step.

[0009] In addition, the method for manufacturing a stabilizer according to the present invention is characterized in that, in the above invention, it further includes a burr removal step of removing burrs from an area including the through hole formed in the through hole forming step.

[0010] Furthermore, the manufacturing method of the stabilizer according to the present invention is characterized in that, in the above invention, the convex portion forming step forms the convex portion that is set based on the amount of sagging that is predicted based on actual measurement data of the degree of sagging that occurs when the through hole is formed.

[0011] Furthermore, the base material according to the present invention is a base material for manufacturing a stabilizer having through holes formed at both ends by a forging process, and is characterized in that it has a convex portion formed at the end of the base material at a through hole formation position corresponding to the through hole in the stabilizer. [Effects of the Invention]

[0012] According to the present invention, it is possible to suppress a decrease in flatness of both end portions of the stabilizer. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a side view showing an example of the configuration of a stabilizer manufactured in one embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a region R shown in FIG. [Figure 3] FIG. 3 is a diagram illustrating a manufacturing method for producing the stabilizer shown in FIG. [Figure 4] FIG. 4 is a view showing a base material for producing the stabilizer shown in FIG. 1 before forging. [Figure 5] FIG. 5 is a diagram showing the structure of the end portion of the base material before the forging process. [Figure 6] FIG. 6 is a cross-sectional view taken along line AA shown in FIG. [Figure 7] FIG. 7 is a diagram (part 1) showing an example of a cross section of an end portion of a stabilizer in which through holes are formed using a base material having protrusions. [Figure 8] FIG. 8 is a diagram (part 2) showing an example of a cross section of an end portion of a stabilizer in which through holes are formed using a base material having protrusions. [Figure 9] FIG. 9 is a diagram (part 1) showing an example of a cross section of an end portion of a stabilizer in which through holes are formed using a base material that does not have a protrusion. [Figure 10] FIG. 10 is a diagram (part 2) showing an example of a cross section of an end portion of a stabilizer in which through holes are formed using a base material that does not have a protrusion. [Figure 11] FIG. 11 is a diagram illustrating the flatness at the end of a stabilizer in which through-holes are formed using a base material having protrusions. [Figure 12] FIG. 12 is a diagram for explaining the flatness at the end of a stabilizer in which through holes are formed using a base material that does not have a protrusion. [Figure 13]FIG. 13 is a diagram illustrating the parallelism at the end of a stabilizer in which a base material having a convex portion is used to form a through hole. [Figure 14] FIG. 14 is a diagram for explaining the parallelism at the end of a stabilizer in which through holes are formed using a base material that does not have a protrusion. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. Note that the drawings are schematic, and the relationship between the thickness and width of each part, the thickness ratio of each part, etc. may differ from the actual ones, and the drawings may also include parts with different dimensional relationships and ratios.

[0015] (Embodiment) Fig. 1 is a side view showing an example of the configuration of a stabilizer manufactured in one embodiment of the present invention. The stabilizer 1 shown in Fig. 1 is made of metal or various fibers (e.g., carbon fiber). The stabilizer 1 has a main body 2 that is bent at both ends and extends linearly in the center, a first end 3 provided at one end of the main body 2, and a second end 4 provided at the other end of the main body 2.

[0016] The main body 2 extends in a columnar shape, for example, a cylindrical shape, and may be hollow or solid.

[0017] The first end portion 3 has a flat plate shape and is formed with a through-hole 31 that penetrates through the first end portion 3 in the plate thickness direction. The second end portion 4 has a flat plate shape and is formed with a through-hole 41 that penetrates through the second end portion 4 in the plate thickness direction. For example, when the stabilizer 1 is installed in an automobile, the first end 3 is connected to one of the left and right suspensions, and the second end 4 is connected to the other suspension. At this time, each end is fixed to the suspension by inserting a fastening member such as a bolt through the through hole.

[0018] Here, each end (first end 3 and second end 4) is required to have a flat fastening portion in order to prevent a decrease in the fastening strength between the vehicle and stabilizer 1 by the fastening member. FIG. 2 is an enlarged view of region R shown in FIG. 1. FIG. 2 shows the first end 3, which is similar to the second end 4. For example, in the first end 3, region 32 located around the through hole 31 is required to have a flat surface.

[0019] Next, a manufacturing method of the stabilizer 1 will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a diagram for explaining a manufacturing method for producing the stabilizer shown in Fig. 1. The stabilizer 1 is manufactured by forging a base material.

[0020] The base material 10 is formed by bending both ends of a column, and has a main body 11, a first end 12, and a second end 13. First, the first end 12 and the second end 13 of the base material 10 are heated (see FIG. 3(a): heating step). In the heating process, each end is heated using, for example, a heating coil 110.

[0021] After heating both ends of the base material 10, each end is pressed (see FIG. 3(b): flattening step). For example, as shown in FIG. 3(b), an end of the base material 10 (first end 12 in FIG. 3) is held by a holding member 120a, and the end placed on this holding member 120a is pressed by a pressing member 120b, thereby crushing the end and flattening it (see FIG. 3(c)). At this time, recesses 120c are formed in the pressing member 120b at positions corresponding to the positions where the through holes in the base material 10 will be formed. Therefore, by flattening, protrusions corresponding to the shape of the recesses 120c are formed at the ends of the base material 10 (protrusion forming step). In this embodiment, the flattening step and the protrusion forming step are performed simultaneously.

[0022] Fig. 4 is a diagram showing a base material for producing the stabilizer shown in Fig. 1 before forging. Fig. 5 is a diagram showing the configuration of the end portion of the base material before forging. Fig. 6 is a cross-sectional view taken along line AA shown in Fig. 5. The base material 10 shown in Figs. 4 and 5 has a main body portion 11 having both ends bent, a first end portion 12 provided at one end of the main body portion 11, and a second end portion 13 provided at the other end of the main body portion 11. Furthermore, protrusions 12a and 13a are formed on the first end portion 12 and the second end portion 13, respectively.

[0023] For example, the protrusion 12a is frustum-shaped and protrudes from the first end 12. The protrusion 12a is set at a position and shape that suppresses sagging when a through hole is formed. For example, the protrusion 12a is set based on the amount of sagging predicted based on actual measurement data of the degree of sagging that occurs when a through hole is formed. The formation range of the protrusion 12a, for example, the region having a diameter of width W1 at the base end protruding from the first end 12, is set according to the region of the first end 12 (first end 3) where a fastening member is disposed. The region where the fastening member is disposed is a region of the first end 12 that requires high flatness and parallelism. The protrusion 12a is formed, for example, in a region that is equal to or greater than the region where the fastening member is disposed. Furthermore, the width W1 of the protrusion 12a is set to be 30% to 70% of the width W2 at the tip end. Furthermore, the protrusion length H1 of the protrusion 12a is set in the range of 1% to 10% of the thickness H2 of the first end 12 at a position excluding the protrusion 12a. In this embodiment, the protrusion 12a is described as having a truncated cone shape, but it may have another convex shape, such as a truncated pyramid shape. The same applies to the protrusion 13a.

[0024] Returning to FIG. 3, after the first end 12 and the second end 13 are formed, a cutting process is carried out (see FIG. 3(d)). In the cutting process, a through-hole forming process (through-hole forming step) and a trimming process (trimming step) are performed on the first end 12 and the second end 13. FIG. 3(d) shows an example of the processing of the first end 12, but the same applies to the second end 13.

[0025] The through-hole is formed by punching the first end 12 using a punching member 130a. At this time, the first end 12 is placed on a support member 130b and pressed against the support member 130b by a stripper 130c. The support member 130b and the stripper 130c have a hollow portion through which the tip of the punching member 130a can be inserted. The punching member 130a is passed through the stripper 130c to punch out the first end 12 at the position where the through-hole is to be formed, including the protrusion 12a, thereby forming a through-hole (through-hole 12b shown in FIG. 3(e)) in the first end 12.

[0026] In the trimming process, the trimming blade 130d is used to form the outer shape of the first end portion 12 (see (d) of FIG. 3). In the trimming process, the trimming blade 130d is used to form the processing line L of the first end portion 12, as shown in FIG. C The outer shape of the first end 3 is formed by cutting along the line. The order of the through-hole formation and the trimming process may be any.

[0027] After the cutting process, a burr removal process is performed to remove burrs using the molding member 140a (see (e) of FIG. 3: burr removal step). At this time, the first end portion 12 is placed on the support member 140b. By sandwiching the first end portion 12 between the molding member 140a and the support member 140b, burrs formed around the through-hole 12b are crushed and removed. In this way, the stabilizer 1 shown in FIG. 1 is produced.

[0028] Here, the difference in cross-sectional shape depending on whether or not the base material has a convex portion will be described with reference to Figs. 7 to 10. Figs. 7 and 8 are diagrams showing an example of a cross section of the end of a stabilizer in which a through hole is formed using a base material with a convex portion. Fig. 7 shows the outer edge of the end of the stabilizer in a cross section cut along a plane perpendicular to the longitudinal direction of the end of the stabilizer. In Fig. 7, outer edge L1 shows the left side as viewed from the main body 2, and outer edge L2 shows the right side as viewed from the main body 2. Fig. 8 shows the outer edge of the end of the stabilizer in a cross section cut along a plane parallel to the longitudinal direction of the end of the stabilizer and perpendicular to the cut plane of Fig. 7. In Fig. 8, outer edge L3 shows the outer edge on the main body 2 side, and outer edge L4 shows the outer edge opposite to the main body 2 side. 9 and 10 are diagrams showing an example of a cross section of an end portion of a stabilizer in which through holes are formed using a base material having no protrusions. Fig. 9 shows the outer edge of the end portion in a cross section cut along a plane perpendicular to the longitudinal direction of the end portion of the stabilizer. Fig. 9 shows the outer edge L 11 is the left side when viewed from the main body 2, and the outer edge L 12 10 shows the right side as viewed from the main body 2. FIG. 10 shows the outer edge of the end of the stabilizer in a cross section taken along a plane parallel to the longitudinal direction of the end of the stabilizer and perpendicular to the cross section of FIG. 7. FIG. 10 shows the outer edge L 13 is the main body part 2 side, outer edge L 14 indicates the outer edge opposite to the main body 2 side. 7 and 8, and 9 and 10 show the end portions of stabilizers in which through holes of the same diameter are formed using base materials of the same plate thickness. The arrows in Figs. 7 to 10 indicate the direction in which the perforating member enters. As can be seen from FIGS. 7 to 10, the base material having a protrusion and having a through hole formed therein (FIGS. 7 and 8) has a smaller degree of sagging and can be said to have a better flatness. In addition, in Figs. 7 to 10, r MIN indicates the minimum diameter of the area where flatness and parallelism must be ensured (for example, see area 32 in Figure 2), and r MAX indicates the maximum diameter of the area where flatness and parallelism must be ensured. MIN and r MAX It is necessary to ensure flatness and parallelism within the area enclosed by the square.

[0029] The differences in flatness and parallelism depending on whether or not the base material has a protrusion will be described with reference to FIGS. 11 to 14. Note that FIGS. 11 to 14 show the results for the end of stabilizers manufactured using base materials of the same material and shape except for the presence or absence of the protrusion, and the flatness and parallelism are normalized with the standard reference value set to 1. FIG. 11 is a diagram illustrating the flatness at the end of a stabilizer in which through-holes are formed using a base material with a protrusion. FIG. 12 is a diagram illustrating the flatness at the end of a stabilizer in which through-holes are formed using a base material without a protrusion. In FIGS. 11 and 12, for each sample, the plot of flatness of one surface at one end of the stabilizer (e.g., first end 3) is indicated by a circle. Similarly, the plot of flatness of the other surface at one end is indicated by a black circle, the plot of flatness of one surface at the other end (e.g., second end 4) is indicated by a square, and the plot of flatness of the other surface at the other end is indicated by a black square. 11 and 12, the stabilizer made using a base material with convex portions has a smaller flatness at the end as a whole. In addition, the stabilizer made using a base material without convex portions has a larger difference in flatness between both sides of the end.

[0030] FIG. 13 is a diagram illustrating the parallelism at the end of a stabilizer in which through-holes are formed using a base material having convex portions. FIG. 14 is a diagram illustrating the parallelism at the end of a stabilizer in which through-holes are formed using a base material having no convex portions. In FIGS. 13 and 14, for each sample, the plot of parallelism at one end of the stabilizer (e.g., first end 3) is indicated by a circle, and the plot of flatness at the other end (e.g., second end 4) is indicated by a black circle. As shown in FIGS. 13 and 14, the stabilizer manufactured using a base material having convex portions has a smaller parallelism at both ends overall. In addition, the stabilizer manufactured using a base material having no convex portions has a larger difference in parallelism at both ends.

[0031] In the embodiment of the present invention described above, a protrusion is formed in the base material for manufacturing the stabilizer at the position where the through hole is to be formed, and the through hole is formed by punching out the area including the protrusion. According to this embodiment, the formation of the protrusion suppresses the occurrence of sagging during punching, thereby suppressing the decrease in flatness of both ends of the stabilizer. Furthermore, suppressing the occurrence of sagging also improves the accuracy of burr removal.

[0032] Furthermore, in the embodiment, the formation of the protrusions can also suppress warping of the end portions caused by the load during punching. This suppression of warping can more reliably suppress the reduction in flatness and parallelism caused by the formation of the through holes.

[0033] Although the embodiments for carrying out the present invention have been described above, the present invention should not be limited to the above-described embodiments. For example, the present invention can be applied to products in which through-holes are formed by punching or trimming is performed. Furthermore, in the embodiments, an example in which a convex portion is formed while flattening the end of the base material 10 has been described, but the flattening and convex portion formation may be performed at different times. That is, in the embodiments, the flattening step and the convex portion formation step are performed simultaneously, but the flattening step and the convex portion formation step may be performed at different times.

[0034] In this way, the present invention can include various embodiments not described here, and various design changes can be made within the scope that does not deviate from the technical idea specified by the claims.

[0035] As described above, the stabilizer manufacturing method and base material according to the present invention are suitable for suppressing a decrease in flatness at both end portions of the stabilizer. [Explanation of symbols]

[0036] 1 stabilizer 2, 11 Main body 3, 12 First end 4, 13 Second end 10 Base material 12a, 13a convex part 31, 41 Through holes 120a holding member 120b pressing member 120c recess 130a Perforating member 130b, 140b Support members 130c Stripper 130d trim blade 140a Molded member

Claims

1. A method for manufacturing a stabilizer by forging a base material to produce a stabilizer having through holes formed at both ends, comprising: a convex portion forming step of forming a convex portion on an end portion of the base material at a through-hole forming position corresponding to the through-hole in the stabilizer; a through-hole forming step of forming a through-hole at the through-hole forming position including the convex portion; Including, In the convex portion forming step, the end portion of the base material after the convex portion is formed has a flat surface on the side opposite to the side where the convex portion is formed. A method for manufacturing a stabilizer.

2. The convex portion forming step forms the convex portion while flattening the end portion of the base material.

2. The method for manufacturing a stabilizer according to claim 1.

3. a heating step of heating the end portion of the base material; further comprising The convex portion forming step forms the convex portion on the end portion heated in the heating step.

3. The method for manufacturing a stabilizer according to claim 1 or 2.

4. a burr removal step of removing burrs from an area including the through hole formed in the through hole forming step; 4. The method for manufacturing a stabilizer according to claim 1, further comprising:

5. The convex portion forming step forms the convex portion that is set based on an amount of sagging that is predicted based on actual measurement data of the degree of sagging that occurs when the through hole is formed.

5. The method for manufacturing a stabilizer according to claim 1.

6. A base material for manufacturing a stabilizer bar having through holes formed at both ends by forging, a protrusion formed at an end of the base material at a through-hole formation position corresponding to the through-hole in the stabilizer; Equipped with At the end of the base material, the side opposite to the side where the protrusion is formed forms a flat surface. A base material characterized by:

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