JP2003126922A - Hydraulic molding method of hollow structural parts and its structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic molding method of suspension members for cars which has no protrusion on the edge of the flange and has a good appearance quality of relatively smooth outline. SOLUTION: A suspension member 1 is formed by swelling a laminated plate material 2 placed between the upper and lower molds using a hydraulic pressure. A indented part 11 is formed by advancing a presser 8 while the hydraulic pressure is rising, activating the pressure work on a part of a flange 7 and its vicinity, and forming a tip of the flange 7 (including a welded part 3) without protruding over an outer profile 13 of a general shape 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydraulically forming a hollow structural component, such as a suspension member for an automobile, and the structure of the hollow structural component itself. The present invention relates to a hydraulic forming method for a hollow structural part, which is formed by bulging by hydraulic pressure using a laminated plate material formed by welding the outer peripheral portion, and a structure of the hollow structural part.

[0002]

2. Description of the Related Art A laminated plate material formed by laminating metal plates and welding their outer peripheral portions is sandwiched between a pair of upper and lower molds provided with recesses, and the metal plates of the laminated plate material are A hydraulic forming method for supplying a high-pressure molding medium in between to form a shape that matches the shape of the concave portion of the mold is known, for example, in JP-A-11-347643 and JP-A-10-85944. ing.

[0003]

In such a conventional technique, since the outer peripheral portion of the laminated plate material is preliminarily continuously welded in order to secure the hydraulic sealing property, this portion is not welded. Will remain as a flange portion projecting over the entire circumference of the hollow structural component after molding, and this is not preferable because the quality of the appearance will deteriorate depending on the component to be applied.

From the above, the flange portion is locally removed by cutting or the like after the hydraulic forming, and the post-welding is partially performed again for the portion where the appearance quality is important in the function of the parts. Although a method of applying it to obtain a hollow structural part having a smooth outer shape is adopted, this method has a problem that the processing step and the number of man-hours are increased, and the dimensional accuracy of the part is deteriorated by welding after forming. was there.

Therefore, the present invention is premised on a hydraulic forming method capable of manufacturing a hollow structural component having a complicated shape with high accuracy and at a relatively low cost, and eliminates the protrusion of the edge portion of the flange portion to form An object of the present invention is to provide a hydraulic molding method capable of easily manufacturing a hollow structural component having a relatively smooth appearance and an excellent quality in an extremely short manufacturing process, and a structure of an automobile suspension member to which the molding method is applied. .

[0006]

According to a first aspect of the present invention, there is provided a laminated plate material formed by stacking metal plates on each other and welding the outer peripheral portion thereof between a pair of molds provided with a recess. It is a method of bulging a hollow structural part having a shape matching the concave shape of the mold by sandwiching it between the metal plates of the laminated plate material and supplying a high-pressure molding medium between the metal plates. As a result, the flange portion that will be additionally formed on the outer peripheral portion of the structural component area while having the welded portion on the distal end surface is processed so that at least a part of the distal end portion thereof is substantially flush with the general surface of the structural component. The feature is that it is performed during molding.

In this case, the processing for flattening the surface is performed by pressing inwardly of the structural component region while supplying the molding medium between the metal plates as described in claim 2. The position of the tip of the flange portion is regulated by applying a pressing force by the child, or the pressing force can be applied toward the inside of the structural component region as described in claim 3. Before pressing the forming medium between the metal plates, the pressing element is placed in the mold in advance, and the pressing force is applied by the pressing element toward the inside of the structural component area as the molding progresses due to the feeding of the forming medium. It is desirable to regulate the position of the tip of the flange portion by adding

According to a fourth aspect of the present invention, a laminated plate material formed by stacking metal plates on each other and welding their outer peripheral portions is sandwiched between a pair of molds provided with recesses, and the laminated plate material is formed. Is a structure of an automobile suspension member formed by supplying a high-pressure molding medium between the metal plates to form a hollow structural part in a shape that matches the concave shape of the mold, and the welded portion is the tip. With respect to the flange portion that is to be additionally formed on the outer peripheral portion of the suspension member area while being on the surface, the tip portion of the portion to be located on the vehicle front side in the vehicle mounted state is substantially flush with the general surface of the suspension member. It is characterized by being processed.

According to a fifth aspect of the present invention, a laminated plate material formed by stacking metal plates on each other and welding the outer peripheral portion thereof is sandwiched between a pair of molds provided with recesses to form a laminated plate material. This is a method of expanding a hollow structural part having a shape matching the concave shape of the mold by supplying a high-pressure molding medium between the metal plates, and as the molding progresses, the welded portion is tipped. With respect to the flange portion which is to be additionally formed on the outer peripheral portion of the structural component region while having the surface, processing for bending at least a part of the tip end portion is performed during the forming.

In this case, as described in claim 6, while the molding medium is being supplied between the metal plates, a pressing force is applied to the tip end of the flange part by the pressing element so that the flange part is formed. After the process of bending the tip of the flange part or the process of bending the tip of the flange part as described in claim 7, the pressure of the internal molding medium is further increased to It is desirable to perform dimensional correction.

Further, as described in claim 8, instead of performing the process of bending the tip portion of the flange portion during molding, the tip portion of the region of the laminated plate material to be the flange portion is previously formed. Bending may be performed in advance, and bulging may be performed using the curved laminated plate material.

According to a ninth aspect of the present invention, a laminated plate material formed by stacking metal plates on each other and welding their outer peripheral portions is sandwiched between a pair of metal molds provided with recesses to form a laminated plate material. Is a structure of an automobile suspension member formed by supplying a high-pressure molding medium between the metal plates to form a hollow structural part in a shape that matches the concave shape of the mold, and the welded portion is the tip. The flange portion that will be incidentally formed on the outer peripheral portion of the suspension member area while having the surface is characterized in that the tip portion of the portion that will be located on the front side of the vehicle when mounted on the vehicle is curved I am trying.

[0013]

According to the invention as set forth in claim 1, at least a part of the front end of the flange portion to be additionally molded on the outer peripheral portion of the structural component region is substantially the same as the general surface of the structural component. Since the same process is performed during molding, the tip of the flange part does not project from the general surface of the structural part to ensure the smoothness of the outer surface of the necessary part, maintaining the dimensional accuracy and the appearance quality. It is possible to easily manufacture excellent molded products with the minimum manufacturing process.

According to the second aspect of the present invention, as the processing for equalizing the surface, the position of the tip of the flange portion is regulated by applying a pressing force toward the inside of the structural component region by the pressing element. As a result, the peripheral shape of the flange portion is substantially formed by transferring the shape of the presser, and even if the pressure of the forming medium is relatively low, it can be formed with accurate shape accuracy. A highly precise hollow structural component can be obtained.

According to the third aspect of the present invention, in the processing for surface equalization, the pressing element is arranged in advance in the mold before the molding medium is supplied between the metal plates, and the molding is performed. Since the position of the tip of the flange portion is regulated by applying a pressing force by the pressing element toward the inside of the structural component region as the molding progresses by the supply of the medium, compared with the one described in claim 2. The molding cycle time required for hydraulic molding can be shortened by the amount of time required for the pusher to move forward.

According to the invention described in claim 4, substantially, the hydraulic forming method according to claim 1 is applied to the molding of the flange portion on the front side of the vehicle in the suspension member for an automobile. As for the necessary part, the tip of the flange does not project from the general surface of the suspension member and the smoothness of the outer surface is ensured, and it is possible to provide a suspension member for automobiles with excellent appearance quality while maintaining dimensional accuracy. .

According to the invention described in claim 5, substantially, instead of the processing for flattening according to claim 1, the flange portion to be additionally formed on the outer peripheral portion of the structural component region. Regarding, since the processing of bending at least a part of the tip portion is performed during molding, the tip portion of the flange portion is curved and the outer surface smoothness is secured for a necessary portion, It is possible to easily manufacture molded products with excellent appearance quality while maintaining dimensional accuracy with the minimum number of manufacturing processes.

According to the sixth aspect of the invention, since the pressing force is applied to the tip end portion of the flange portion by the pressing element during the hydraulic forming, the tip end portion of the flange portion is curved. It is possible to easily manufacture hollow structural parts with excellent appearance quality by the limited manufacturing process.

According to the seventh aspect of the present invention, after the bending of the tip of the flange portion is performed, the pressure of the internal molding medium is further increased to perform the dimension correction processing of the structural component. By applying a further high pressure in a state where the material inflow is substantially restricted, higher shape fixability and dimensional accuracy of the structural component can be secured without increasing the manufacturing process.

According to the invention described in claim 8, at the stage of the laminated plate material, the tip of the region to be the flange portion is preliminarily curved, and the curved laminated plate material is used. Since it is designed to be hydraulically molded,
It is possible to control the material inflow to stop the material inflow at a predetermined position, and it is possible to reliably prevent cracks in the welded part due to excessive material inflow and leakage of the forming medium due to this, and to freeze the shape of structural parts higher due to the dimension correction effect And dimensional accuracy can be secured.

According to the invention described in claim 9, substantially, the hydraulic molding method according to claim 5 is applied to the molding of the flange portion on the front side of the vehicle in the suspension member for an automobile. Since the front end of the flange portion is curved in the required portion, the smoothness of the outer surface of the member is ensured, and it is possible to provide a suspension member for an automobile having excellent appearance quality while maintaining dimensional accuracy.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a suspension member as an example of a hydraulically molded automobile structural part to which the present invention is applied. FIG. 2 is a perspective view showing the laminated plate member 2 before the suspension member 1 is molded. Further, FIGS. 3A to 3D are cross-sectional views showing a manufacturing process of the suspension member 1 using the laminated plate material 2 described above,
It has shown the cross-section part along the AA line of FIG.

As shown in FIGS. 3A and 3B, the suspension member 1 shown in FIG. 1 is provided between the upper mold 4 and the lower mold 5 of a mold provided with a recess space 4a or 5a, respectively. As shown in FIG. 2, the metal plates 2a and 2b forming the laminated plate material 2 sandwiching the laminated plate material 2 whose outer peripheral portion is, for example, in the form of a lip joint and continuously welded at the welded portion 3 are sandwiched. The liquid pressure P is exerted by supplying a liquid molding medium between the two, and the concave space 4 of the upper and lower molds 4 and 5 is
It is bulged to have an outer surface shape that matches the inner surface shapes of a and 5a. After molding, the flange portion 7 is molded over the entire circumference as shown in FIG.

The laminated plate material 2 shown in FIG. 2 is processed to have a desired outer shape after molding, has a molding medium injection hole portion 6 in a part thereof, and has two upper and lower metal plates 2a, 2b are welded parts 3 along the entire outer circumference
Is formed, and the welded portion 3 also serves as a sealing means for hydraulic pressure during molding. It should be noted that the injection hole portion 6 is appropriately cut off after molding if necessary. Further, the plate thickness and material of the upper and lower metal plates 2a and 2b forming the superposed plate member 2 are not limited to specific ones and can be appropriately selected according to design requirements.

Here, the manufacturing method of the suspension member 1 will be described in more detail with reference to FIG. 3. First, in FIG. 3A, the upper and lower molds 4 and 5 are respectively movable inwardly and backwardly of the mold. A movable pusher 8 is provided. With the presser 8 retracted, the overlapping plate member 2 is sandwiched between the upper and lower molds 4 and 5 and is pressed and restrained by a predetermined mold clamping force. Next, when a molding medium is supplied between the metal plates 2a and 2b forming the laminated plate material 2 to apply hydraulic pressure P as shown in FIG. 2B, the laminated plate material 2 swells. The parts corresponding to the recesses 4a and 5a of the mold are molded as the general shape part 10, and the parts corresponding to the dividing surfaces of the upper and lower molds 4 and 5 are molded as the flange part 7, respectively.

Further, in the process of increasing the hydraulic pressure P, the movable pressing element 8 is advanced to a predetermined position as shown in FIG. 2C, whereby the flange portion 7 formed on the outer periphery of the suspension member 1 is formed. A pressing force is locally applied to the vicinity thereof, so that the concave portion 11 is formed so that the tip end surface 12 (including the welded portion 3) of the flange portion 7 does not project at least from the outer contour 13 of the general shape portion 10. Then, as shown in FIG. 3D, after the hydraulic pressure P is released, each pusher 8 is retracted to the initial position, and the suspension member 1
The molding is completed by taking out.

FIG. 4 shows a molded suspension member 1.
FIG. 3 is a plan view showing the relationship between the pressing member 8 and the pressing member 8, and is located on the front side of the vehicle when the suspension member 1 is mounted on the vehicle out of the flange portion 7 to be additionally formed on the outer periphery of the suspension member 1. About the part that becomes
The flange portion 7 is formed by locally applying a pressing force by the pressing element 8 in the range of Z in FIG.
In order to prevent the tip surface 12 of the flange portion 7 from projecting at least from the outer contour 13 of the general shape portion 10, a recess 11 is formed in the range Z in which the height of the tip surface 12 is restricted.
Is being processed.

The suspension member 1 having the sectional structure shown in FIG. 5 can be obtained by the above-described molding procedure. Here, the front end surface 1 of the flange portion 7 on the vehicle front side
The height of 2 is set to be lower than the outer contour 13 of the general shape portion 10 by the dimension W (W ≧ 0).

In this way, the portion corresponding to the range Z of the tip portion of the flange portion 7 additionally formed on the outer periphery of the suspension member 1 formed with the superposed plate member 2 is substantially flush with the general surface of the suspension member 1. In the processing such that
At least the front end surface 12 of the general outline 1 of the general shape portion 10
By simultaneously performing the processing for restricting the height to be equal to or less than 3 in the hydraulic forming step, the tip of the flange portion 7 does not protrude from the general surface of the suspension member 1 which is a hollow structural member. As a result, it is possible to easily manufacture the suspension member 1 having excellent appearance quality while maintaining high dimensional accuracy in an extremely short manufacturing process.

In the present embodiment, since the pressing element 8 is pressed by the pressing force that overcomes the hydraulic pressure P,
The concave portion 11 is formed in the vicinity of the flange portion 7 so that the shape of the presser 8 is transferred, so that it has a characteristic that it can be formed into a sharp shape even if the hydraulic pressure P is relatively low. There is.

FIG. 6 shows a second embodiment of the present invention.

In FIG. 6A, the upper and lower molds 4 and 5 are provided with movable pushers 8 that can move inward and backward, respectively, as in the case of the previous embodiment. is there.

In the present embodiment, the stacking plate member 2 is sandwiched between the upper and lower molds 4 and 5 with the pressing element 8 already advanced, and the pressing force is restricted by a predetermined mold clamping force. Next, when hydraulic pressure P is applied between the metal plates 2a and 2b forming the laminated plate material 2 as shown in FIG. 2B, the laminated plate material 2 swells and the upper and lower molds 4, 5 are formed. The suspension member 14 as a hollow structural component is obtained by molding so as to match the concave spaces 4a and 5a. Here, since the pressing element 8 is already in the advanced state before the hydraulic pressure is applied to the laminated plate material 2, the recessed portion 11 similar to that in the previous embodiment is formed in the suspension member 14. Next, as shown in FIG. 6C, after releasing the hydraulic pressure P, the movable pressing element 8 is retracted to a predetermined position, whereby the suspension member 14 can be taken out, and the molding is completed.

In this way, the tip surface 1 of the flange portion 7
It is extremely easy to manufacture the suspension member 14 having a good appearance quality in which 2 does not protrude from the outer contour 13 of the general molding portion. Further, in the present embodiment, since the molding is performed in a state where the presser 8 has been advanced in advance, the cycle time required for hydraulic molding is shortened by the time required for the advancement of the presser 8,
There is an advantage that the time required for molding can be shortened.

FIG. 7 shows a third embodiment of the present invention.

In this embodiment, the dividing positions of the upper and lower dies 16 and 17 and the pressers 18 and 19 are changed, and the other basic parts are the same as in the previous embodiments.

In FIG. 7A, the upper mold side is constituted by the upper mold 16 and the upper pressing member 18, while the lower mold side is constituted by the lower mold 17 and the lower pressing member 19, respectively.
The upper pusher 18 and the lower pusher 19 are independently movable in the lateral direction. The upper pressing member 18 and the lower pressing member 19 are each formed with a convex portion 20 or 21. FIG. 1A shows a state before the molding in which the overlapping plate material 2 is sandwiched between the upper and lower dies 16 and 17.

After that, when hydraulic pressure P is applied between the metal plates 2a and 2b of the laminated plate member 2 as shown in FIG. 6B, the laminated plate member 2 swells and the concave portions of the upper and lower molds 16 and 17 are depressed. The suspension member 22 as a hollow structural component molded so as to match 16a and 17a is obtained.
Here, the concave portion 11 having a shape matching the convex portions 20 and 21 formed on the upper pressing element 18 and the lower pressing element 19 is formed.

Next, as shown in FIG. 6C, after the hydraulic pressure P is released, the upper pusher 18 and the lower pusher 19 are respectively retracted to predetermined positions and the upper and lower molds 16 and 17 are opened mutually. Thus, the suspension member 22 is taken out and the molding is completed.

Also in the third embodiment, the same effect as in the first and second embodiments can be obtained.

In each of the above-described embodiments, the drive means for each of the pressing elements 8, 18 and 19 is not only an independent control mechanism such as a hydraulic / pneumatic cylinder or a screw mechanism that has been generally used in the past but also hydraulic molding. A cam slide mechanism, a ball screw mechanism, or the like that uses the stroke of the mold clamping machine at that time can be appropriately used. These driving means may be appropriately selected in relation to the mold structure. For example, in the first embodiment shown in FIG. 3, by using an independent control mechanism such as a hydraulic / pneumatic cylinder or a screw mechanism, it is possible to improve the driving force. Precise control is possible,
Further, in the second and third embodiments shown in FIGS. 6 and 7, it is possible to use a cam slide mechanism utilizing the stroke of the mold clamping machine, and it is possible to make a relatively inexpensive and simple mold structure. There are advantages.

FIG. 8 shows a fourth embodiment of the present invention.

First, as shown in FIG. 8 (A), a recess space 25a or 26a corresponding to the shape of the molded product is formed.
In addition to the upper mold 25 and the lower mold 26, the upper mold 25 has a pusher 28 configured to be movable in the vertical direction.
A driving means 27 such as a hydraulic cylinder for driving the same is mounted, and a concave curved portion 24 is formed at the tip of the pressing element 28. On the other hand, the lower die 26 is formed with a bending die portion 29 having a predetermined shape and a clearance space 30.

As shown in FIG. 5A, the same laminated plate material 2 as in the previous embodiment is sandwiched between the upper mold 25 and the lower mold 26, and is pressed and restrained by a predetermined mold clamping force. Next, as shown in FIG. 2B, the metal plates 2a and 2b of the laminated plate material 2 are
By supplying a molding medium between them, the hydraulic pressure P is applied to the inside of the superposed plate material 2 to perform a predetermined expansion molding. At this time, the laminated plate material 2 having the width dimension X at the beginning
Is the width Y of the suspension member 33 as a hollow structural component smaller than the X dimension due to the material inflow due to the swelling.
Becomes

Here, the movable pusher 28 is lowered to a predetermined position as shown in FIG.
A curved portion 32 is formed on a front flange portion 31 that is sandwiched between a concave curved portion 24 formed at the tip of 8 and a bending die portion 29. Then, after releasing the hydraulic pressure P, the presser 2
8 to the initial position and the upper and lower molds 25, 26
Open, the suspension member 33 is taken out, and the molding is completed.

As described above, the process of locally bending the tip end of the flange portion 31 to be additionally formed on the outer peripheral portion of the suspension member 33 with respect to another general flange portion is performed simultaneously with the hydraulic forming. Post-processing is unnecessary, and as shown in FIG. 9, the front end of the flange portion 31 is curved as the curved portion 32 only in the necessary portion, and there is no protrusion of the edge portion toward the front side. 33 will be obtained.

Further, in FIG. 8C, when the hydraulic pressure P is further increased after forming the curved portion 32 on the front flange portion 31, the curved portion 32 locally restricts the material inflow. Since the hydraulic pressure P acts on the suspension member 33, the dimension correction effect of the suspension member 33 is produced, the shape fixability of the suspension member 33 is improved, and the suspension member 33 having higher dimensional accuracy can be molded.

In the present embodiment, the welding of the metal plates 2a and 2b in the laminated plate member 2 is shown by way of example in the case of end face welding such as a lip joint, but the present invention is not limited to this and will be described later. It is also possible to use lap welding or fillet welding.

FIG. 10 shows a fifth embodiment of the present invention.

As shown in FIG. 6A, the recessed spaces 34a or 3 corresponding to the shapes of the structural parts to be molded are formed.
In addition to an upper mold 34 and a lower mold 35 on which 5a is formed, a pressing member 36 that can move forward and backward in the lateral direction of the mold and a driving means such as a hydraulic cylinder for driving the pressing member 36 are provided. 37 is attached. A pointed protrusion 41 and a concavely curved portion 40 are formed at the tip of the pusher 36. on the other hand,
The superposed plate material 122 includes upper and lower metal plates 122a, 122.
Welded part 3 by lap welding in which b is previously welded over the entire circumference
8 is continuously welded, and a preform portion 39 preformed in a direction in which the upper and lower metal plates 122a and 122b are slightly peeled off from each other is formed. When the superposed plate material 122 is sandwiched between the upper and lower dies 34 and 35, and the hydraulic pressure P is applied between the upper and lower metal plates 122a and 122b, the material is inflated and formed as shown in FIG. It

Therefore, when the pusher 36 which can move back and forth as shown in FIG. 6B is advanced to a predetermined position, the preform is formed by the pointed portion 41 and the concave curved portion 40 formed at the tip of the pusher 36. The portion 39 is further curved in the peeling direction to form the curved portion 4
2 is molded. Then, after releasing the hydraulic pressure P, the pressing element 36 is retracted to the initial position, the upper and lower molds 34 and 35 are opened, and the suspension member 43 is taken out, whereby the molding is completed.

As a result, as shown in FIG. 11, the tip portion of the flange 123 is curved at the necessary portion as shown in FIG.
The suspension member 43 is obtained as a hollow structural component that is curved and has excellent appearance quality without the protrusion of the edge portion toward the front side, and the same effect as that of the previous embodiment can be obtained.

FIG. 12 shows a sixth embodiment of the present invention. In the fifth embodiment, the flange 123 is curved at the same time during the hydraulic forming, whereas in the present embodiment, the bending is performed. , The curved portion 51 is preliminarily processed at a predetermined position at the stage of the laminated plate material 50 whose outer peripheral portion is welded with the welded portion 3, and the processed laminated plate material 50 of the curved portion 51 is processed.
Is used as a material to perform hydraulic forming.

As shown in FIG. 12A, an upper mold 45 and a lower mold 46, each of which has a recess space 45a or 46a corresponding to the shape of the molded product, are provided.
A seal part 47 and an escape space 48 are formed in the lower mold 46. On the other hand, the upper and lower metal plates 50 are
The end surfaces of a and 50b are continuously welded in advance in the form of an edge joint with the welded portion 3 and the curved portion 51 is locally bent beforehand by press working or the like.

This laminated plate material 50 is used for the upper and lower molds 45, 4
When sandwiched between 6 and subjected to hydraulic pressure P between the metal plates 50a and 50b, swelling is carried out with material inflow as shown in FIG. 12 (B), similar to that shown in FIG. The suspension member 33 as a hollow structural component having the curved portion 51 at the tip of the flange portion 31 is obtained.

Further, the curved portion 51 formed in advance on the flange portion 31 on the front side comes into contact with the seal portion 47 of the lower mold 46 as the material inflows, and the material inflow is blocked here. It is possible to positively control the material inflow to prevent the peeling and breaking of the welded portion 3 due to the. Moreover, if the hydraulic pressure P is further increased from the state where the material inflow is restricted as shown in FIG. 7B, the effect of correcting the dimension of the suspension member 33 can be obtained as in the fifth embodiment. The suspension member 33 with high dimensional accuracy can be obtained.

FIG. 13 shows a modified example of the curved portion 51 formed on the laminated plate material 50 of FIG.
It is sectional drawing which expanded only.

As shown in the figure, in the laminated plate member 52, the upper and lower metal plates 53, 54 are welded and joined to each other at their entire circumferences with a welded portion 55 formed by overlapping fillet welding, and only a specific portion is locally bonded. A curved portion 56 in which the upper metal plate 53 is curled toward the lower metal plate 54 is formed in advance. Even when such a laminated plate member 52 is used, it is possible to use the same mold as that of the sixth embodiment and to use the same manufacturing method.

As described above, the processing for locally bending the required portion of the tip end of the flange portion is performed at the same time as the hydraulic forming, or the curved portion is preformed at the stage of the laminated plate material. As a result, it is possible to obtain a suspension member as a hollow structural component which does not require post-processing and has a superior appearance quality with no protrusion of the edge portion to the front side with a minimum manufacturing process.

In each of the above-mentioned embodiments, an example in which end face welding, fillet welding or lap welding is used as the welding form of the welded portion of the laminated plate material is shown, but the form of the weld joint is not limited to this. In addition, various welding methods such as arc welding, laser welding, plasma welding, mash seam welding, and friction stir welding can be appropriately selected and used.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a suspension member as an example of a structural part for an automobile molded by applying a hydraulic molding method of the present invention.

FIG. 2 is a perspective view showing a laminated plate material used as a material for the suspension member.

FIG. 3 is a sectional view of a mold showing a hydraulic forming process of the suspension member shown in FIG. 1 as a first embodiment of the hydraulic forming method according to the present invention.

FIG. 4 is a plan view showing the relationship between the suspension member and the pusher of FIG.

5 is a cross-sectional view of the suspension member taken along the line AA of FIG.

FIG. 6 is a cross-sectional view of a mold showing a hydraulic forming step of a suspension member as a second embodiment of the hydraulic forming method according to the present invention.

FIG. 7 is a cross-sectional view of a mold showing a hydraulic forming process of a suspension member as a third embodiment of the hydraulic forming method according to the present invention.

FIG. 8 is a sectional view of a mold showing a hydraulic forming step of a suspension member as a fourth embodiment of the hydraulic forming method according to the present invention.

9 is a cross-sectional view of the suspension member obtained in the molding process of FIG.

FIG. 10 is a cross-sectional view of a mold showing a hydraulic forming step of a suspension member as a fifth embodiment of the hydraulic forming method according to the present invention.

11 is a cross-sectional view of the suspension member obtained in the molding process of FIG.

FIG. 12 is a sectional view of a mold showing a hydraulic forming step of a suspension member as a sixth embodiment of the hydraulic forming method according to the present invention.

FIG. 13 is a cross-sectional view of essential parts showing a modified example of the laminated plate material of FIG. 12.

[Explanation of symbols]

1 ... Suspension member (hollow structure part) 2 ... Laminated board 2a, 2b ... Metal plate 3 ... Welded part 4-upper mold 4a ... Recessed space 5 ... Lower mold 5a ... Recessed space 7 ... Flange 8 ... Presser 11 ... Recess 12 ... Tip surface 14 ... Suspension member (hollow structural component) 16 ... Upper mold 16a ... Recessed space 17 ... Lower mold 17a ... Recessed space 18 ... Presser 19 ... Presser 22 ... Suspension member (hollow structural component) 24 ... Recessed part 25 ... Upper mold 25a ... Recessed space 26 ... Lower mold 26a ... Recessed space 27 ... Driving means 28 ... Presser 31 ... Flange 32 ... Curved part 33 ... Suspension member (hollow structural component) 34 ... Upper mold 34a ... Recessed space 35 ... Lower mold 35a ... Recessed space 36 ... Presser 37 ... Driving means 38 ... Welded part 40 ... concave curve 42 ... Curved part 43 ... Suspension member (hollow structural component) 45 ... Upper mold 45a ... Recessed space 46 ... Lower mold 46b ... Recessed space 50 ... Laminated board 50a, 50b ... Metal plate 51 ... Curved part 52 ... Laminated plate material 53, 54 ... Metal plate 55 ... Weld 56 ... Bending part P ... hydraulic pressure

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Claims (9)

[Claims] 1. A laminated plate material formed by laminating metal plates and welding their outer peripheral portions is sandwiched between a pair of metal molds provided with recesses, and the metal plates of the laminated plate material are sandwiched between the metal plates. This is a method for expanding a hollow structural part that has a shape that matches the concave shape of the mold by supplying a high-pressure molding medium. A hollow structural part characterized in that, during the molding, a flange part to be additionally molded on the outer peripheral part of the region is processed during molding so that at least a part of its tip end is substantially flush with the general surface of the structural part. Hydraulic forming method. 2. The flattening process is performed by applying a pressing force by an indenter toward the inside of the structural component region during the supply of the molding medium between the metal plates. The method for hydraulically molding a hollow structural part according to claim 1, wherein the position of the tip of the hollow part is regulated. 3. The flattening process is carried out in advance before the forming medium is supplied between the metal plates with a presser capable of applying a pressing force toward the inside of the structural component region. It is placed in the mold and regulates the position of the tip of the flange by applying a pressing force toward the inside of the structural part area with a pressing element as the molding progresses by supplying the molding medium. The method for hydraulically molding a hollow structural part according to claim 1. 4. A laminated plate material formed by laminating metal plates and welding their outer peripheral portions is sandwiched between a pair of molds provided with recesses, and the metal plates of the laminated plate material are sandwiched between the metal plates. A suspension member structure for an automobile formed by supplying a high-pressure forming medium to a hollow structure part in a shape that matches the concave shape of a mold. The suspension member has a welded portion on its tip surface. The flange portion that will be additionally molded on the outer peripheral portion of the region has been processed such that the tip of the portion that will be located on the vehicle front side when mounted on the vehicle is approximately flush with the general surface of the suspension member. A suspension member structure for automobiles characterized by. 5. A laminated plate material formed by laminating metal plates and welding their outer peripheral portions is sandwiched between a pair of molds provided with recesses, and the metal plates of the laminated plate material are sandwiched between the metal plates. This is a method for expanding a hollow structural part that has a shape that matches the concave shape of the mold by supplying a high-pressure molding medium. A method for hydraulically molding a hollow structural component, characterized in that a flange portion to be additionally molded on the outer peripheral portion of the region is subjected to a process of bending at least a part of its tip during molding. 6. A process for bending the tip of the flange portion by applying a pressing force to the tip of the flange portion while the molding medium is being supplied between the metal plates by a pressing element. The method for hydraulically molding a hollow structural part according to claim 5. 7. The dimensional correction process for a structural part is performed by further increasing the pressure of an internal molding medium after performing a process of bending the tip end portion of the flange part. Hydroforming method for hollow structural parts. 8. Instead of performing the bending of the tip of the flange portion during molding, the tip of the region to be the flange of the laminated plate material is pre-curved, and The method for hydraulically molding a hollow structural component according to claim 5, wherein the bulging molding is performed by using the curved laminated plate material. 9. A laminated plate material formed by laminating metal plates and welding their outer peripheral portions is sandwiched between a pair of molds provided with recesses, and the metal plates of the laminated plate material are sandwiched between the metal plates. A suspension member structure for an automobile formed by supplying a high-pressure forming medium to a hollow structure part in a shape that matches the concave shape of a mold. The suspension member has a welded portion on its tip surface. A suspension member structure for an automobile, characterized in that a flange portion to be additionally formed on an outer peripheral portion of the region is processed to bend a front end portion of a portion to be located on the front side of the vehicle when mounted on the vehicle. .