JP5689726B2 - Manufacturing apparatus and manufacturing method of overhang molded product - Google Patents

Description

  More specifically, the present invention relates to a stretched product manufacturing apparatus and manufacturing method, and specifically, a blank and a blank holder are restrained by a die and a blank holder so that the blank does not flow, and the blank is processed between the punch and the die. The present invention relates to a manufacturing apparatus and a manufacturing method for an overhang molded product.

  Thin plate press forming is generally roughly divided into two types, bulging and drawing. The overhang forming means that the blank substantially flows in (moves) toward the center of the blank corresponding to the product portion by the blank restraint portion provided mainly at the peripheral edge of the blank during the molding after restraining the blank. This is a molding method that does not. For example, among automotive parts, parts having a relatively simple shape such as a door outer panel and a hood outer panel are generally manufactured by overhang molding.

  On the other hand, draw forming is a process that prevents cracks and wrinkles from occurring in the product by appropriately controlling the amount of blank flowing into the blank restraint during molding after restraining the blank. The molding method to be controlled. For example, parts with relatively complicated shapes such as outer side panels of automobile parts are generally manufactured by drawing. Thus, the overhang forming is a forming method different from the draw forming in that the blank restraint portion substantially eliminates inflow of the blank.

  Up to now, trapezoidal beads and corrugated beads are known as beads that restrain the peripheral edge of the blank with a die and a blank holder in order to prevent the blank from flowing in. The trapezoidal bead has a substantially trapezoidal cross section, and constrains the blank by deformation resistance of bending and unbending deformation of the trapezoidal corner portion and surface pressure of the straight side portion of the cross section. On the other hand, the wavy bead has a substantially trapezoidal cross section, and the top view has a wave shape like a sine wave. In addition to the bending and unbending deformation resistance of the trapezoidal corner portion and the surface pressure at the right side of the cross section, the blank is further constrained by the expansion and contraction deformation resistance according to the wave shape in the top view.

  Further, Patent Documents 1 and 2 disclose inventions in which drawing is performed while controlling the inflow amount of the blank by discontinuous embossing. In paragraph 0016 of Patent Document 1, “As shown in FIG. 3, the pitch Pc between the spot beads 8, 8 is 20 mm, for example, and the diameter D at the root of the spot beads 8 is approximately the same as the width of the main bead 7. 11 mm, the height H of the spot bead 8 is 6 mm, the chamfer dimension Rn of the top peripheral edge of the spot bead 8 is R2, and the taper angle θ of the circumferential surface of the spot bead 8 is set to about 6 °. ” In addition, in the twelfth column of Patent Document 2, “the degree of partial increase in the frictional resistance with respect to the blank (M) is adjusted by the height (H) and the diameter (D) of the bead (34). In addition, the portion to be increased is adjusted by inserting / removing the bead (34) at a position corresponding to this portion.

JP 2000-117340 A JP-A-57-72730

  In the conventional trapezoidal bead, since the restraining force is usually small only by the deformation resistance of bending and unbending deformation of the trapezoidal corner portion, it is indispensable to apply the restraining force by the surface pressure at the straight side portion of the cross section. In order to apply the surface pressure at the straight side, it is important to make sure that the upper and lower molds are face to face, but these operations require a large number of man-hours before the start of mass production. Further, in a continuous bead such as a trapezoidal bead, the blank end is pulled inward during blank holding, and therefore, in a trapezoidal bead having a large cross-sectional line length, the material yield of the blank is lowered.

  Further, compared with the trapezoidal bead, the wavy bead is improved in restraining force due to the expansion and contraction deformation resistance corresponding to the wave shape, and therefore, the man-hour required for aligning the cross-section right side portion can be reduced. However, similarly to the trapezoidal bead, the wavy bead is pulled inward during blank holding, so that the material yield of the blank is lowered. In addition, the material yield of the blank is further reduced by the corrugated shape.

  Furthermore, when the drawing technique disclosed in Patent Documents 1 and 2 is simply diverted to stretch forming, the problems listed below arise.

(A) When the diameter of the bead is increased, the bead is increased and the yield of the blank is reduced.
(B) Increasing the bead height increases the risk of cracking the blank.
(C) If the bead interval is narrowed, the pressing force required to sandwich the blank increases, so that the mechanical capacity is insufficient, the upper and lower molds cannot be pressed, and the blank flows in.

  In the case of continuous beads such as wave beads, it is a problem because the blank cannot be locked if the blank is broken. On the other hand, in the case of the emboss lock, the blank can be locked even if the blank near the top of the emboss is broken. However, when the blank is cracked, there is a possibility that the cracked and dropped part is pushed into the product part and becomes a pushing flaw, which is not preferable.

Patent Documents 1 and 2 do not mention anything about the shape of the concave mold.
Furthermore, in mass-production press molding, the gap is not necessarily zero over the entire circumference due to the elastic deformation of the mold and the workmanship of the mold, but the maximum that can be locked without material flowing in. The locking method with a larger gap between the upper and lower molds (the value obtained by subtracting the original plate thickness from the distance between the molds (hereinafter referred to as “gap margin” in this specification) is more advantageous for mass production stability. However, Patent Documents 1 and 2 do not disclose or suggest a gap margin.

  This invention is made | formed in view of the said subject, restrains the peripheral part of a blank with a die | dye and a blank holder so that a blank may not flow, and processes a blank between a punch and die | dye, and forms an overhanging molded article. When manufacturing, it is possible to securely restrain the blank without requiring a large amount of man-hours for the rigorous work of aligning the upper and lower molds, and to further improve the material yield of the blank. It is to provide a manufacturing apparatus and a manufacturing method.

As a result of intensive studies to solve the above problems, the present inventors have
(I) Since drawing (prior art) and overhanging (the subject of the present invention) are different, they are not in a divertable relationship with each other,
(II) Optimizing the bead size (constraining the constraining of the blank and reducing the area are contradictory to each other. Increasing the bead size, increasing the density to increase the constraining of the blank does not work) (III) By optimizing the gap margin in consideration of mass productivity, it is possible to provide a bead with a small area constrained in the overhang forming, and the product area is improved because the constrained area is small. As a result, the present invention has been completed.

The present invention, a second mold having a first mold having a first blank restraining portion at a position abutting on the periphery of the blank, the second blank restraining portion at a position abutting the peripheral edge of the blank And a third mold for performing overhang molding on the blank by moving with respect to the blank constrained by the first mold and the second mold. At least a part of the blank restraint part is configured by a plurality of convex parts arranged in parallel, and at least a part of the second blank restraint part has a plurality of convex parts arranged in parallel, respectively. An overhang molded product manufacturing apparatus comprising a plurality of concave portions arranged side by side with a gap.

From another point of view, the present invention provides a first mold configured by a plurality of convex portions provided at a position in contact with the peripheral edge of the blank and at least a part of which is arranged in parallel. blank restraining portion, with contact to the periphery of the blank, the second mold, disposed in abutment located on the periphery of the blank, and at least a portion of each of the plurality of protrusions arranged in parallel The blank is restrained by restraining the blank by the convex portion and the concave portion by abutting the second blank restraining portion configured by a plurality of the concave portions arranged side by side with the peripheral portion of the blank. This is a method for producing an overhang molded product, characterized in that the blank is stretched and formed by moving a third mold with respect to the blank.

  In the present invention, as compared with a normal trapezoidal bead, the restraint force is improved by the expansion and contraction deformation resistance according to the cross-sectional shape in the bead line direction, and therefore, the number of steps required for aligning the cross-section right side portions can be reduced. Furthermore, the device of the present invention has a smaller cross-sectional shape compared to a normal trapezoidal bead or corrugated bead, a bead portion is formed by overhanging, and is arranged like a corrugated shape in a top view. Since it is not necessary, the material yield of the blank is greatly improved.

  As described above, according to the present invention, the blank can be surely restrained without requiring a large number of man-hours for the rigorous upper and lower mold face-to-face operations, and further, the material yield of the blank is improved and the overhang molded product is improved. Can be manufactured.

FIG. 1 is an explanatory view showing a situation in which stretch molding is performed using a mold simulating an automobile door outer panel. Fig.2 (a) is a top view which shows arrangement | positioning of a convex part, FIG.2 (b) is sectional drawing which shows the shape of a convex part. FIG. 3A and FIG. 3B are both explanatory views showing the top shape of the convex portion. FIG. 4A and FIG. 4B are explanatory diagrams showing the shape of the recesses. FIG. 5 is an explanatory diagram showing a method for determining the hole diameter of the recess. FIG. 6 is a photograph of an example of the evaluation result. FIG. 7 is a graph showing the results of Example 1. FIG. 8 is a graph showing the results of Example 1. FIG. 9 is a graph showing the results of Example 1. 10A shows the specific dimensions of the “dome shape” in Table 4. 1 is an explanatory diagram showing an example of FIG. 1, and FIG. It is explanatory drawing which shows 6 as an example.

The present invention will be described with reference to the accompanying drawings.
FIG. 1 is an explanatory view showing a situation in which stretch molding is performed using a mold 1 simulating an automobile door outer panel. 2A is a plan view showing the arrangement of the convex portions 3a, and FIG. 2B is a cross-sectional view showing the shape of the convex portions 3a.

  The mold 1 includes a punch 2, a die 3, and a blank holder 4. In order to restrain the blank 5 from flowing in, a plurality of convex portions 3 a are provided on the die 3, and a concave portion 4 a is provided on the blank holder 4.

The convex portion 3a has a hemispherical shape with a top portion having a diameter of about 4 mm, and an axial target shape having a height of 3.0 mm.
The diameter of the convex portion 3a is preferably a substantially circular shape having a diameter of 2 to 6 mm, and more preferably a circular shape having a diameter of about 4 mm. In order to improve the yield of the blank 5, it is preferable that the convex portion has a diameter sufficiently smaller than the bead width of a conventional bead including drawing. Therefore, the embossed diameter is desirably about 6 mm or less. On the other hand, from the viewpoint of improving the yield of the blank 5, it is preferable that the diameter of the convex portion 3a is small. However, as the diameter of the convex portion 3a decreases, it becomes difficult to process the mold, and the convex portion 3a may be broken. . For this reason, it is preferable that the diameter of the convex part 3a is 2 mm or more, and it is further more preferable that it is about 4 mm.

  The height of the convex portion 3a is preferably 0.5 to 1.0 times the diameter of the convex portion 3a. As described above, since the diameter of the convex portion 3a is preferably 2 to 6 mm, the height of the convex portion 3a is preferably 1 to 6 mm. For example, when the diameter of the convex part 3a is 4 mm, it is preferable that it is 2-4 mm. More preferably, it is 0.7 to 0.9 times the diameter of the convex portion 3a. In that case, since the diameter of the convex portion 3a is 2 to 6 mm, the height of the convex portion 3a is in the range of 1.4 to 5.4 mm. For example, when the diameter of the convex part 3a is 4 mm, it is more preferable that it is 2.8-3.6 mm. If the height of the convex portion 3a is larger than the diameter of the convex portion 3a, the blank is broken. On the other hand, if it is smaller than half of the diameter of the convex portion 3a, the restraining force becomes weak and stability cannot be ensured. Therefore, the height of the convex portion 3a is preferably set to 0.5 to 1.0 times the diameter of the convex portion 3a.

  In order to properly secure the above-described gap margin (the maximum gap between the upper and lower molds that can be constrained so that the blank 5 does not flow in, and the value obtained by subtracting the original plate thickness from the distance between the molds). The height of the convex portion 3a is preferably 0.7 times or more the diameter of the convex portion 3a. Since the diameter of the convex part 3a of this invention is 2-6 mm, it is at least 1.4 mm or more. For example, when the diameter of the convex portion 3a is 4 mm, a height of 2.8 mm or more is necessary. The gap margin is preferably about 0.1 mm or more because the gap is often about 0.1 mm in mass production. On the other hand, if the height of the convex portion 3a exceeds 0.9 times the diameter of the convex portion 3a, the possibility that the blank 5 will break near the convex portion 3a increases. It is preferable that it is less than 2 times.

FIG. 3A and FIG. 3B are explanatory views showing the top shape of the convex portion 3a.
This is because the shape of the top portion of the convex portion 3a is a substantially spherical shape, and thus the convex portion 3a is formed so as not to be pulled in from the surroundings toward the convex portion 3a (the yield is not lowered). . At this time, it is also important to make the blank 5 difficult to break. If the shape satisfies such conditions, there is essentially no problem even if it is slightly deviated from the spherical shape. Therefore, the shape of the top of the convex portion 3a is the shoulder portion R as shown in FIG. The same effect can be obtained even in a substantially cylindrical shape having a large shape or a shape having a small top portion R (such as the tip of a pencil) shown in FIG.

  The distance between the centers of the protrusions 3a is 1.3 to 3.0 times the diameter of the protrusions 3a, that is, the diameter of the protrusions 3a of the present invention is 2 to 6 mm, as is the distance between the centers of the recesses 4a described later. Since it is preferable, it is preferable that it is the range of 2.6-18 mm. For example, when the diameter of the convex portion 3a is 4 mm, it is preferably 5.2 to 12 mm. Since the diameter of the convex portion 3a is 2.0 to 2.5 times, that is, the diameter of the convex portion 3a is 2 to 6 mm, it is 4 to 15 mm, and when the diameter of the convex portion 3a is 4 mm, it is further 8 to 10 mm. preferable.

4 (a) and 4 (b) are explanatory diagrams showing the shape of the recess 4a, and FIG. 5 is an explanatory diagram showing a method for determining the hole diameter of the recess 4a.
The concave portion 4a has a shape such that the convex portion 3a is approximately offset to the outside by the thickness of the blank 5, and the radius of curvature of the Rd portion is about 1.3 mm. The distance between the center points of the recess 4a is 8.8 mm.

  As shown in FIG. 5, the lower limit of the hole diameter of the recess 4 a is preferably a shape in which the recess 4 a comes into contact with the blank 5 when the blank 5 is wound around the protrusion 3 a. On the other hand, the upper limit may be expanded to the extent that the blank 5 does not flow.

  For example, the appropriate hole diameter of the concave portion 4 a varies depending on the shape of the convex portion 3 a and the thickness of the blank 5. For example, as shown in FIG. If it is a convex part which consists of a hemisphere and a cylinder like 1, the suitable hole diameter of the recessed part 4a is the range which added 3-4 times the plate | board thickness of the blank 5 to the outer diameter of the convex part 3a. However, if the height of the convex part 3a is high, a large hole diameter is preferable beyond this range, and the shape of the convex part 3a is No. in Table 3 described later. If the apex has a small diameter such as 6, it may be preferable to have a small hole diameter exceeding this range. Therefore, an appropriate hole diameter may be obtained by appropriately selecting as shown in FIG.

  The radius of section of the corner R of the concave side 4a is ¼ to ½ times the diameter of the convex portion 3a in order to prevent the blank from cracking and to reduce the binding force. Since the diameter of the convex portion 3a is preferably 2 to 6 mm, the range of 0.5 to 3.0 mm, for example, when the diameter of the convex portion 3a is 4 mm, may be set to 1.0 to 2.0 mm. preferable.

  Moreover, since the space | interval of the adjacent recessed parts 4a is a center point space | interval and is 1.3 to 3.0 times the diameter of the convex part 3a, and the diameter of the convex part 3a of this invention is 2-6 mm, it is 2.6. When the diameter of the convex portion 3a is 4 mm, it is preferably 5.2 to 12 mm. The diameter of the convex portion 3a of the present invention is 2.0 to 2.5 times the diameter of the convex portion 3a. Is in the range of 4 to 15 mm, for example, when the diameter of the convex portion 3a is 4 mm, it is more preferably 8 to 10 mm.

  In order to prevent the blank 5 between the adjacent concave portions 4a from flowing in, the center point interval is 3.0 times or less the diameter of the convex portion 3a, and the diameter of the convex portion 3a of the present invention is 2 to 6 mm. 18 mm or less at the maximum, for example, when the diameter of the convex portion 3 a is 4 mm, it is preferable to set it to 12 mm or less, and considering the load of the general press (blank hold load), the center point interval is set to the diameter of the convex portion 3 a. Since the diameter of the projection 3a of the present invention is 2 to 6 mm at least 1.3 times, the minimum is set to 2.6 mm or more. For example, when the diameter of the projection 3a is 4 mm, it is preferably set to 5.2 mm or more.

  If the interval between the adjacent recesses 4a is too narrow, the pressing force required to sandwich the blank 5 increases, so that the mechanical capacity is insufficient, the upper and lower molds cannot be pressed down, and the blank 5 flows in. . On the other hand, if this interval is too wide, the restraining force is reduced, and the pressing force required to prevent the blank 5 from flowing in increases.

The thickness of the blank 5 is preferably 0.6 to 0.8 mm, which is a general thickness of the drawing material.
Assuming a gap between the mass production molds, in order to prevent the blank 5 between the adjacent recesses 4a from flowing in, the center point interval is 2.5 times or less the diameter of the protrusion 3a, and the protrusion of the present invention. Since the diameter of 3a is 2 to 6 mm, it is preferably set to 15 mm or less at the maximum. For example, when the diameter of the convex portion 3a is 4 mm, it is preferably set to 10 mm or less. In consideration of the press load (blank hold load), the center point interval is 2.0 times or more the diameter of the convex portion 3a, and the diameter of the convex 3a of the present invention is 2 to 6 mm. When the diameter of the convex portion 3a is 4 mm or more, for example, it is preferably set to 8.0 mm or more.

  The above ranges are summarized as shown in Table 1.

  Next, the operation of this embodiment will be described. First, the blank 5 is put on the die 3. Next, the blank holder 4 is lowered, and the blank 5 is sandwiched between the die 3 and the blank holder 4. At this time, the bead portion of the blank 5 is protruded small by the hemispherical convex portion 3a to form a bead shape. Next, the punch 2 is lowered and pressed to the inside of the convex portion 3a of the blank 5 constrained by the convex portion 3a, whereby molding is performed.

  At this time, the bead portion of the blank 5 receives a tensile force that is pulled inward. In addition to bending and bending deformation resistance according to the cross section in the inflow direction of the blank 5 and the surface pressure of the straight side portion, the convex portion 3a generates expansion and contraction deformation resistance of the blank 5 according to the cross sectional shape in the bead line direction. For this reason, it has a restraining force superior to the above-described tensile force, and restrains without causing the blank material to flow during molding, and press molding (extrusion molding) is performed.

The present embodiment has the following effects.
(1) The blank 5 has a small cross-sectional line length, and as described above, the blank 5 is stretched to form a bead. Therefore, the amount of inflow at the end of the blank 5 is the same as that during blank holding and molding. Is a small value of about 2 mm or less. Furthermore, the bead width in the inflow direction is also small. Therefore, for example, the material yield can be improved by about 5 to 15 mm on one side as compared with the corrugated bead.

(2) As described above, since the restraining force is larger than that of a normal trapezoidal bead, the blank material can be restrained even if a slight gap exists between the upper and lower molds. For example, in this embodiment, even if a gap of about 0.4 mm exists, the blank material can be constrained, and strict face-to-face alignment work is not required.

(3) The interval from the ring profile to the bead is short. In the conventional bead, in order to prevent the occurrence of mold cracks at the corners of the recess 4a, the distance from the ring profile to the bead is set to be as wide as 7 to 10 mm, for example. However, in the present invention, the depth of the concave portion 4a can be set shallow because the convex portion 3a is low, and since it is discontinuous, the crack at the corner portion of the concave portion 4a, which becomes a neck for shortening the interval from the ring profile to the bead. The bending moment, which is the cause of the occurrence of The interval from the ring profile to the bead can be shortened to 5 mm.

(4) The length in the tensile direction of the convex portion 3a itself is short. The depth of the convex part 3a and the concave part 4a of the present invention can be reduced because the restraining force is higher than that of the conventional bead. Further, when the blank material is sandwiched (= when blank holding), the pull-in of the blank 5 is minimal. Since the convex portion 3a and the concave portion 4a of the present invention are discontinuous, the pull-in of the blank 5 is small, but the conventional bead is bent continuously, so the pull-in amount is large. As a result, the material yield was improved by 7 mm. Since the 9 to 12 mm base material can be made smaller on one side, the entire base material can be made 18 to 24 mm in length and width.

  The optimum shape (height H of the convex portion) of the mold 1 having the convex portion 3a and the concave portion 4a of the present invention shown in FIG. It examined from two viewpoints of the danger that the blank 5 of the top part of 3a will fracture | rupture.

  The blank 5 which is a material to be tested is a cold-rolled alloyed hot-dip galvanized steel sheet having a tensile strength of 340 MPa and having a thickness of 0.75 mm, which is very common for use in outer panels such as doors. The test method is a test in which the end of a blank 5 having a width of 40 mm is sandwiched with a predetermined pressing force with the mold 1 of the manufacturing apparatus according to the present invention shown in FIG. 1 and pulled out until somewhere in the blank 5 breaks. . When the blank 5 can be locked (in this specification, “lock” means prevention of the flow of the test target material), the inflow amount of the blank 5 becomes a small value of less than 1 mm, and the blank 5 Fracture occurs at the outer portion of the mold 1 having the recess 4a. The pressing force of the blank 5 was set to 40 kgf / mm (load per 1 mm in the lengthwise direction of the uneven shape).

(1) Experimental method 1-1 Gap margin quantification The maximum gap that does not exceed 1 mm during molding after blank holding after the blank 5 inflow (evaluated by the average value of the sliding trace length at the center three points) is defined as the gap margin. Defined and quantified the effect of the height of the protrusion 3a on the gap margin. For comparison, the gap margin was also quantified in the conventional wave beads. Table 2 shows the experimental conditions.

(2) Blank fracture risk assessment near emboss <Condition 1: Blank hold only>
By applying a pressing force until there is no gap between the upper and lower molds 1 having the convex portion 3a and the concave portion 4a (until the distance between the convex portion 3a and the concave portion 4a matches the plate thickness of the blank 5), the complete hold state is achieved. Simulated. The plate thickness (thinnest portion) in the vicinity of the convex portion 3a and the rough skin state during complete holding were evaluated.
<Condition 2: Blank hold->Pull>
As shown in Table 3, the molding process was simulated by blank-holding to a set pressing force of 40 kgf / mm and withdrawing as it is. The plate thickness (thinnest portion) in the vicinity of the convex portion 3a after drawing and the rough skin state were evaluated. FIG. 6 shows a photograph of an example of the evaluation result.

(3) Experimental results The experimental results are summarized in the graphs of FIGS. In addition, when the inflow amount of the test object material was less than 1 mm, it was determined that the test object was locked. As shown in FIG. 6, in the blank 5 after the test, a sliding trace corresponding to the length of the flowed in remains in a portion where the contact surface pressure with the mold 1 is strong. Therefore, the amount of inflow was judged from the length of the sliding trace with the mold 1 in contact with the blank 5.

  As shown in FIG. 7, the inflow amount (sliding trace length) increased with an increase in the gap setting in both the wave beads of the comparative example and the inventive example. Further, as shown in the graph of FIG. 8, the inflow amount in the gap between the same upper and lower molds 1 was reduced and the gap margin was increased as the height of the convex portion 3a was increased from 2.0 to 3.3 mm. .

  Furthermore, as shown in the graph of FIG. 9, it was possible to secure a gap margin equal to or greater than that of the wave bead at the height of the convex portion 3a of about 2.9 mm.

  1-4, various dimensions of the mold having the convex portion 3a and the concave portion 4a shown in FIGS. 1 to 4 are produced to produce an overhang molded product from a 340 MPa class cold-rolled galvannealed steel plate having a thickness of 0.75 mm, Appearance and required pressing force were measured. Table 4 summarizes the test conditions and test results. It should be noted that the setting condition of the gap between the upper and lower molds 1 of this embodiment is that the gap between the upper and lower molds 1 is often about 0.1 mm at the time of mass production. The pressure was 40 kgf / mm, and the gap between the upper and lower molds was 0.1 mm.

  Moreover, in Table 4, the yield with respect to the conventional example is a case where the reduction width of the trimmed portion is 5 mm or more under the condition that does not consider the reduction allowance of the interval between the ring profile and the blank restraint portion (bead portion or uneven shape). In the appearance inspection, a case where there was no crack or plating peeling was evaluated as a case where it was less than 5 mm, and a case where it was less than 5 mm was evaluated as ×. Furthermore, the case where the lock | rock of the blank 5 was able to be achieved was set as (circle), and the case where it cannot be achieved was set as x.

  In Table 4, “tapered shape” means that the radius of curvature at the top of the convex portion is smaller than the radius of the convex portion, and the base has a substantially cylindrical shape of the convex portion with a slope whose cross-sectional shape is substantially straight. “Dome” means a shape having a hemispherical shape in which the radius of curvature at the top of the convex portion is the same as the radius of the convex portion.

  10A shows the specific dimensions of the “dome shape” in Table 4. 1 is an explanatory diagram showing an example of FIG. 1, and FIG. It is explanatory drawing which shows 6 as an example.

  As shown in FIG. 10A, the “dome shape” is a shape in which the hemisphere 11 is placed on the columnar body 10. No. in Table 4 1, a hemisphere 11 having a radius of 2.0 mm is placed on a cylinder 10 having an outer diameter of 4.0 mm. Although omitted in FIG. 10A, the height of the convex portion 12 can be arbitrarily adjusted by cutting a thread at the root of the component of the convex portion 12. Moreover, when the convex part 12 is damaged, only the damaged part can be replaced | exchanged. No. in Table 4 1, the height of the convex portion 12 was adjusted to 3.0 mm, and the height of the cylindrical body 10 exposed from the mold was set to 1.0 mm.

  On the other hand, as shown in FIG. 10B, the “tapered shape” is a shape in which the hemisphere 14 is placed on the truncated cone 13. Moreover, you may make the truncated cone 13 into a cylinder as needed. No. in Table 4 6, the top is a hemisphere 14 having a radius of 1.0 mm. Below the hemisphere 14 is a truncated cone 13, and the boundary between the hemisphere 14 and the truncated cone 13 is 2.0 mm. A portion of the truncated cone 13 expands toward the root with a diameter of 2 mm per height of 1 mm, and when the diameter reaches 4.0 mm, a portion below it becomes a cylindrical body. Of the parts of the convex part 15 and the parts of the convex part 15, the part buried in the mold is formed into a cylindrical shape. 1, the height of the convex portion 15 can be arbitrarily adjusted by cutting a thread at the root of the component of the convex portion 15. No. in Table 4 6, the height of the convex portion 15 is adjusted to 3.0 mm, the height of the cylindrical body exposed from the mold is 1.0 mm, the height of the truncated cone 13 is 1.0 mm, and the height of the hemispherical body 14 is The height was 1.0 mm.

  From the results shown in Table 4, the effect of the present invention is clear.

1 Mold 2 Punch 3 Die 3a Convex 4 Blank holder 4a Concave 5 Blank

Claims (2)

A first mold having a first blank restraining portion at a position abutting on the periphery of the blank, and a second mold having a second blank restraining portion abuts located on the periphery of the blank, the In a production apparatus for an overhang molded product comprising a first mold and a third mold for performing overhang molding on the blank by moving relative to the blank constrained by the second mold,
At least a part of the first blank restraint portion is constituted by a plurality of convex portions arranged side by side,
At least a part of the second blank restraint portion is constituted by a plurality of recessed portions arranged in parallel to accommodate the plurality of protruding portions arranged in parallel with a gap, respectively. Manufacturing equipment for overhang molded products. The first mold, provided the contact is located at the periphery of the blank, and the first blank restraint portion constituted by a plurality of projections at least part of which is arranged the peripheral edge portion of the blank And at least a part of each of the plurality of juxtaposed portions provided with a gap between the second mold and the peripheral edge of the blank. The blank which restrained the blank by the convex part and the concave part, and was restrained by contacting the peripheral part of the blank with the 2nd blank restraint part constituted by a plurality of concave parts arranged in parallel A method for producing an overhang molded product, wherein the blank is overmolded by moving a third mold.