JP4701814B2 - Liquid pressure molding die and method for producing partially reinforced molded product - Google Patents

Description

  The present invention relates to a method for producing a molded product partially provided with a reinforced part, which is molded by a hydraulic molding process (hydroform process), and a hydraulic molding die for use in this method.

  Conventionally, a metal element tube (or element plate) is set in a pair of upper and lower molds, a liquid is introduced into the element tube, pressure is applied to the liquid, and axially from the tube end as necessary. There is known a hydraulic forming process (hydraulic bulging process) in which a blank is expanded by applying a compressive force to obtain a tubular product following the molded shape in a mold.

  A molded product formed by the above-described hydraulic forming process may be required to have high strength partially. In this case, the strength can be increased by using a thick tube or a high-strength tube, but problems such as an increase in the weight of the product and an increase in material cost occur. A method is adopted in which another member (reinforcing member) having a high strength is joined to a portion requiring reinforcement by welding or the like to increase the strength. Hereinafter, a product obtained by reinforcing a molded product with a reinforcing member is referred to as a “partially reinforced molded product”.

  However, in a partially reinforced molded product in which a reinforcing member is joined by welding or the like to a part of a molded product formed by hydraulic forming, the reinforcing member 12 is formed as a molded product 11 as shown in FIG. It will bulge more. Accordingly, in the case where it is necessary to make the partially reinforced molded product 10 a predetermined outer diameter shape (H) under the restriction of the shape or the like of the peripheral member to which the partially reinforced molded product is attached, it is shown in FIG. As described above, this is achieved by reducing the tube diameter of the molded product 11, and between the predetermined outer diameter shape (H) in the portion of the partially reinforced molded product 10 where the reinforcing member 12 is not welded to the molded product 11. There was a problem that a gap was generated. Moreover, as shown to Fig.5 (a), the difference in a pipe diameter arises between the part which welded the reinforcement member 12 to the molded article 11, and the other part in the partial reinforcement | strengthening molded product 10, and a pipe shape deform | transforms. There was a bug that it would end up.

  Therefore, in Patent Document 1, after a reinforcing material is disposed outside the metal pipe (hollow member) and an adhesive is interposed between the metal pipe and the reinforcing material, it is inserted into a molding die. In addition, a bulge forming technique has been proposed in which a high-pressure liquid is injected into a hollow portion of a metal base tube to swell, thereby obtaining a tubular product that follows the molded shape in the mold. According to this technology, a metal base tube and a reinforcing material can be molded in the same process to obtain a partially reinforced molded product composed of an integrated reinforcing member and molded product. The product follows the mold shape.

Further, in Patent Document 2, in a state where the metal element tube is inserted into a reinforcing material (reinforcing metal tube) having an inner diameter larger than the outer diameter, the metal element tube is subjected to a hydroforming process, A technique for expanding the pipe and the reinforcing material at the same time has been proposed. According to this technology, it is possible to obtain a deformed annular product that is partially reinforced without being bonded or welded with an adhesive. It is imitated.
Japanese Patent Laid-Open No. 11-5125 JP 2001-334316 A

  When the technique described in Patent Document 1 is used, when a molded product having a complicated shape is formed by a hydraulic forming process, a pre-press is generally performed. Immediately before, when it is necessary to apply an adhesive, there remains a problem that the adhesive cannot be applied. Further, since the metal base tube and the reinforcing material are bonded at the time of molding, there is a possibility that the metal base tube and the reinforcing member are displaced and the reinforcing member is bonded at an unexpected position.

  In addition, when the technique of Patent Document 2 is used, when the metal base tube and the reinforcing material are expanded at the time of molding, the corners of the reinforcing base tube are at the portions where the reinforcing base tube abuts the metal base tube. Since the metal is pressed while being in contact with the pipe, the metal base pipe may be broken. Moreover, in order to prevent generation | occurrence | production of shaping | molding defect, the relationship of the thickness of a metal base tube and a reinforcement raw material will be limited. And although a tubular molded product can be reinforced with an annular reinforcing member, it cannot be adapted when the reinforcing member is not tubular.

  By the way, the peripheral member to which the partially reinforced molded product is attached may have a space for the partially reinforced molded product, and the partially reinforced molded product is accommodated in the predetermined space. The strength of the partially reinforced molded product was found to be insufficient, and it may be necessary to replace the partially reinforced molded product with a higher strength reinforcing member. As a countermeasure for this, when changing the design of a partially reinforced molded product, as described above, the thickness of the reinforcing member is increased and the molded product is molded smaller, but a new mold is required and the cost is reduced. There is a problem that it becomes bulky. As a countermeasure, when the design of the peripheral member is changed, there is a problem that the shape of the peripheral member needs to be changed and the cost is increased, or the change is impossible depending on the peripheral member.

  Therefore, in the present invention, in view of the above-described background art and problems, when manufacturing a partially reinforced molded product obtained by reinforcing a molded product of a hydraulic molding process with a reinforcing member, a reinforcing portion and other parts in the external shape of the partially reinforced molded product A method of manufacturing a partially reinforced molded product capable of reducing a difference in diameter and a change in an outer shape of the portion and flexibly responding to a change in the thickness of the reinforcing member, and hydraulic forming used for the method We propose a mold for use.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, in claim 1, a liquid for molding a molded product of a partially reinforced molded product constituted by fixing a reinforcing member made of a molded plate material to a reinforcing part partially provided in the molded product. It is a pressure molding die, and a reinforcing part molding surface for molding a reinforcing part of a molded product among molding surfaces formed inside the mold is formed by a telescopic mold that can be attached to and detached from the mold. The molding surface of the mold is formed by removing the overall shape of the reinforcing member from the outer shape of the partially reinforced molded product, and the reinforcing portion is reinforced by the mold according to the shape of the reinforcing member. Only the entire shape of the member is molded into a shape that is recessed from the outer shape of the partially reinforced molded product. Between the reinforced portion of the molded product and the non-reinforced portion other than the reinforced portion, stress is applied to the molded product. Molding to avoid stress concentration between the non-reinforcing part and the reinforcing part The is gently what shape transitional portion is bent is formed.

The manufacturing method of a partially reinforced molded product according to claim 2, comprising: a molded product and a reinforcing member made of a molded plate material fixed to a reinforcing portion partially provided in the molded product. It has a molding surface with a shape that excludes the overall shape of the reinforcing member from the outer shape of the reinforced molded product, and the reinforcing part molding surface that molds the reinforcing part of the molded product is formed with a detachable telescopic mold. Using the molding die thus obtained, a metal base tube is molded by a hydraulic molding process to obtain the molded product, and the reinforcing member is fixed to the reinforcing portion of the molded product thus obtained, thereby partially reinforcing the molded product. The reinforcing portion is formed into a shape that is recessed from the outer shape of the partially reinforced molded product by the entire shape of the reinforcing member according to the shape of the reinforcing member, and the reinforcing portion of the molded product Between the non-reinforcing part other than the reinforcing part, it is added to the molded product. To avoid that the stress is concentrated between the reinforcing portion and the non-reinforcing portion due to stress, in which shape transitional portion is gently bent molded article is formed.

  As effects of the present invention, the following effects can be obtained.

In claim 1, by replacing only the telescopic mold, it is possible to obtain a plurality of types of molded products. Therefore, by changing the telescopic mold, the overall outer shape is substantially the same and the shape of the reinforcing member is the same. Different partially reinforced molded products can be manufactured, which can contribute to cost reduction.
Further, the reinforcing part of the molded product is formed with a concave part of the entire shape of the reinforcing member, and the reinforcing member is fitted into the concave part, so that the partially reinforced molded product formed by the non-reinforcing part of the molded product and the reinforcing member In the outer shape, the reinforcing member does not bulge, and the change in the outer shape due to the provision of the reinforcing member can be reduced.

  According to the second aspect of the present invention, the recessed portion of the overall shape of the reinforcing member is formed in the reinforcing portion of the molded product, and the reinforcing member is fitted into the recessed portion, so that it is formed by the non-reinforcing portion of the molded product and the reinforcing member. In the outer shape of the partially reinforced molded product, the reinforcing member does not bulge, and the change in the outer shape due to the provision of the reinforcing member can be reduced. In addition, because only multiple insert molds can be replaced, multiple types of molded products can be obtained. The product can be manufactured, and the thickness change of the reinforcing member can be flexibly dealt with.

Next, embodiments of the invention will be described.
FIG. 1 is a cross-sectional view of a partially reinforced molded product according to an embodiment of the present invention, FIG. 2 is a diagram showing a molding die for molding a molded product, and FIG. 3 is a state of the molding die during a hydraulic molding process. FIG. FIG. 4 is a cross-sectional view of a partially reinforced molded product according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a conventional partially reinforced molded product.

  As shown in FIGS. 1A and 1B, a partially reinforced molded product 10 according to the present invention includes a molded product 11 and a reinforcing member 12 fixed to the molded product 11. The partially reinforced molded product 10 is obtained by partially reinforcing a molded product 11 with a reinforcing member 12, and the reinforcing member 12 is fixed to the molded product 11 by welding or the like. Such a partial reinforcement | strengthening molded product 10 can be used as the structural member of motor vehicles, such as a side frame used for a suspension member, and a cross member.

  The reinforcing member 12 constituting the partially reinforced molded product 10 is formed by press working or the like into a shape in which the metal plate material is matched to the reinforcing portion 11b of the molded product 11 such as a substantially L-shaped section or a substantially U-shaped section. Molded plate material.

  Moreover, the molded product 11 which comprises the partial reinforcement | strengthening molded product 10 is shape | molded by the hydraulic molding process, and the non-reinforcement part 11a and the reinforcement part 11b are formed. A predetermined outer shape of the partially reinforced molded product 10 (outer shape of the partially reinforced molded product 10 according to the design) is formed by the reinforcing member 12 and the non-reinforced portion 11a of the molded product 11.

  The non-reinforcing portion 11 a is a portion of the molded product 11 that does not require reinforcement, and forms a part of the outer shape of the partially reinforced molded product 10. The non-reinforcing portion 11a is molded following a predetermined outer shape of the partially reinforced molded product 10.

  On the other hand, the reinforcing portion 11b is a portion of the molded article 11 that fixes the reinforcing member 12 to improve the strength, and only the entire shape of the reinforcing member 12 according to the shape of the reinforcing member 12 is the partially reinforced molded product 10. It is formed into a shape that is recessed from the outer shape. In addition, in order to avoid that stress concentrates between the non-reinforcing part 11a and the reinforcing part 11b due to the stress applied to the molded article 11 between the reinforcing part 11b and the non-reinforcing part 11a of the molded article 11. A shape transition portion in which the molded article 11 is gently bent is formed.

  Then, the reinforcing member 12 is fitted into the recess of the overall shape of the reinforcing member 12 formed in the reinforcing portion 11b of the molded product 11. Therefore, in the outer shape of the partially reinforced molded product 10 formed by the non-reinforcing portion 11a and the reinforcing member 12 of the molded product 11, the reinforcing member 12 does not bulge, and the outer shape by providing the reinforcing member 12 Changes can be reduced.

  Then, the manufacturing method of the said partial reinforcement | strengthening molded product 10 is demonstrated.

  As described above, the molded product 11 of the partially reinforced molded product 10 is molded by a hydraulic molding process. As shown in FIG. 2, a molding die 20 for molding the molded product 11 is fitted in a pair of upper and lower upper molds 21 and 22 and a fitting portion 22 a provided in the lower mold 22. And the nested mold 24.

On the mating surface of the upper mold 21 and the lower mold 22, a hollow portion having a molded shape in which a molded product is molded is formed. Further, the insert mold 24 is disposed facing the upper mold 21 or the lower mold 22 in the hollow portion.
A molding surface 23 for molding the outer shape of the molded product 11 in the molding die 20 by the inner peripheral surface of the upper mold 21 or the lower mold 22 and the inner peripheral surface of the insert mold 24 in the hollow portion. Is formed.
In the molding surface 23 of the molding die 20, at least a portion for molding the reinforcing portion 11 b of the molded product 11 is constituted by the nested die 24.

  That is, the molding surface 23 of the molding die 20 has a shape obtained by excluding the overall shape of the reinforcing member 12 from the outer shape of the partially reinforced molded product 10, and among them, the reinforcing portion that molds the reinforcing portion 11 b of the molded product 11. The molding surface 24 a is formed by the telescopic mold 24.

  In the molding die 20 having the above-described configuration, the metal element tube 30 is inserted into the molding surface 23, and the metal element tube 30 is subjected to a hydraulic forming process. In the hydroforming process, a liquid is introduced into the metal base tube 30, pressure is applied to the liquid, and a compressive force is applied in the axial direction from the end of the tube as necessary, as shown in FIG. Then, the metal base tube 30 swells, and a tubular molded product 11 that follows the shape of the molding surface 23 is obtained. And the reinforcement member 12 is fixed by welding to the reinforcement part 11b of the molded product 11, and the partial reinforcement | strengthening molded product 10 is manufactured.

  The insert mold 24 which is one of the constituent members of the mold 20 can be attached to and detached from the lower mold 22 and can be replaced with the insert mold 24 having the reinforcing portion forming surface 24a having a different shape. is there. Therefore, it is possible to mold the molded product 11 having the shape of the different reinforcing portions 11 b using the same upper mold 21 and lower mold 22.

  For example, like the partially reinforced molded product 10 shown in FIG. 1A and the partially reinforced molded product 10 shown in FIG. 1B, the overall outer shape is substantially the same, and the thickness of the reinforcing member 12 In the case of manufacturing a reinforcing part having a different shape such as a shape, a pair of upper and lower upper molds 21 and 22 and two types of nested molds 24 are prepared as the molding mold 20. good.

  That is, when molding a partially reinforced molded product 10 having substantially the same outer shape and only the shape of the reinforcing portion 11b of the molded product 11 is different, when molding the second and subsequent molded products, the upper mold There is no need to newly manufacture 21 or the lower mold 22. The insert mold 24 can be manufactured at a lower cost than the upper mold 21 and the lower mold 22, and can contribute to cost reduction.

  Further, the partially reinforced molded product 10 manufactured as described above has substantially the same outer shape even when the thickness of the reinforcing member 12 is changed as shown in FIGS. 1 (a) and 1 (b). It can have. Therefore, even if the strength of the partially reinforced molded product 10 is changed, it is possible to eliminate the need to change the shape of the peripheral member that fixes the partially reinforced molded product 10 and flexibly cope with the strength change of the partially reinforced molded product 10. be able to.

  In the present embodiment, the telescopic die 24 is detachably attached to the lower die 22, but can be provided on either one or both of the upper die 21 and the lower die 22. Further, the number of the nested molds 24 provided in one molding die 20 is not limited to a single number, and may be plural. Further, the molded article 11 according to the present embodiment has a substantially rectangular cross section, and the reinforcing member 12 has a U-shaped cross section. However, the present invention is not limited to these, and the molded article 11 and the reinforcing member 12 having various shapes. It can be.

  For example, as shown to Fig.4 (a), the cross-section which fixed the reinforcing member 12 of L-shaped cross section to each corner | angular part of the molded article 11 which is a substantially rectangular closed cross-section pipe | tube with the shaping | molding method which concerns on this invention. A substantially rectangular partially reinforced molded product 10 can also be manufactured. In this case, the insert mold 24 is fitted in each of the upper mold 21 and the lower mold 22, and at least a molding surface for forming the reinforcing portion 11 b of the molded product 11 is configured by the insert mold 24.

  For example, as shown in FIG. 4 (b), a reinforcing member 12 having a semicircular cross section is fixed to a molded product 11 which is a circular closed cross section tube, and a partially reinforced molded product 10 having a substantially circular cross section, 4 (c), a partially reinforced molded product 10 having a substantially polygonal cross section in which a reinforcing member 12 having a semi-polygonal cross section is fixed to a molded product 11 that is a polygonal closed cross-section tube is molded according to the present invention. It can be manufactured by a method.

  In the case of the long partially reinforced molded product 10, the reinforcing portion 11 b can be formed on at least a part of the molded product 11 in the longitudinal direction, and the reinforcing member 12 can be fixed to the reinforcing portion 11 b by welding.

Sectional drawing of the partial reinforcement | strengthening molded product which concerns on the Example of this invention. The figure which shows the metal mold | die for shape | molding a molded article. The figure of the mode of the metal mold for molding at the time of hydraulic forming. Sectional drawing of the partial reinforcement | strengthening molded product which concerns on the Example of this invention. Sectional drawing of the conventional partial reinforcement | strengthening molded product.

DESCRIPTION OF SYMBOLS 10 Partial reinforcement | strengthening molded product 11 Molded product 11a Non-reinforcement part 11b Reinforcement part 12 Reinforcement member 20 Mold for molding 21 Upper mold 22 Lower mold 24 Nest mold 24a Reinforcement part molding surface

Claims (2)

A hydraulic molding die for molding a molded product of a partially reinforced molded product constituted by fixing a reinforcing member made of a molded plate material to a reinforcing part partially provided in the molded product. ,
Of the molding surfaces formed inside the mold, the reinforcing part molding surface for molding the reinforcing part of the molded product is formed with a telescopic mold that can be attached to and detached from the mold,
The molding surface of the mold is a shape obtained by removing the overall shape of the reinforcing member from the external shape of the partially reinforced molded product ,
By the mold, the reinforcing portion is formed into a shape recessed by the overall shape of the reinforcing member in accordance with the shape of the reinforcing member, compared to the outer shape of the partially reinforced molded product, Between the non-reinforcing portion other than the reinforcing portion, the molded product is gently bent to avoid stress concentration between the non-reinforcing portion and the reinforcing portion due to stress applied to the molded product. A shape transition is formed,
A hydraulic molding die characterized by the above. In a method for manufacturing a partially reinforced molded product, comprising a molded product and a reinforcing member made of a molded plate material fixed to a reinforcing portion partially provided in the molded product,
A nesting mold having a molding surface having a shape obtained by removing the overall shape of the reinforcing member from the outer shape of the partially reinforced molding product, and a detachable telescopic portion for molding the reinforcing portion of the molded product of the molding surface. Using the molding die formed in
The metal base tube is molded by hydroforming to obtain the molded product,
A partially reinforced molded product is manufactured by fixing the reinforcing member to the reinforcing part of the obtained molded product ,
The reinforcing portion is formed into a shape that is recessed from the outer shape of the partially reinforced molded product by the entire shape of the reinforcing member according to the shape of the reinforcing member, and other than the reinforcing portion of the molded product and the reinforcing portion. Between the non-reinforcing part, there is formed a shape transition part that gently bends the molded product to avoid stress concentration between the non-reinforcing part and the reinforcing part due to stress applied to the molded product. To be
A method for producing a partially reinforced molded product.

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