JP4825509B2 - Molding method of resin parts - Google Patents

Description

  The present invention relates to a resin component molding apparatus that molds a resin component such as an automobile fender panel, and a resin component molding method that molds a resin component such as an automobile fender panel.

  Generally, a front fender panel of an automobile is bent downward from the mating portion of the front fender panel with the engine hood. The front fender panel has a flange portion located under the engine hood. As described above, the flange portion is provided at a portion of the front fender panel that is bent below the engine hood. Since the front part of the front fender panel is located below the engine hood, it is difficult to see from outside the vehicle.

  The front fender panel may be molded with resin. This type of front fender panel is formed by a pair of molds. Specifically, the front fender panel is molded by a first mold and a second mold movable in a direction away from and approaching the first mold.

  A cavity space corresponding to the shape of the front fender panel to be molded is formed between the first mold and the second mold. This space is filled with molten resin. The filled resin is released after the resin parts are hardened.

  In such a case, the portion protruding in the direction intersecting the relative movement direction of the first mold with the second mold on the front fender panel is the first mold so that the resin parts are smoothly released. The cavity space is formed so as to be located on the partition line with the second mold.

  That is, when the front fender panel is released from the first mold and the second mold, the front fender panel is not caught by the first mold and the second mold.

  On the other hand, the mating part of the front fender panel with the engine hood is a protruding part as described above.

  Therefore, the cavity space is formed so that the mating portion is located on the part tension line.

  However, the part corresponding to the partition line in the resin molded part tends to generate a step and tends to be difficult to paint. Therefore, in the front fender panel molded so that the mating portion is positioned on the partition line, a step is generated in the mating portion and the coating is not applied, so that the appearance is deteriorated. In particular, the mating portion can be seen from the outside of the vehicle, which is not preferable in terms of the vehicle body appearance.

  In order to eliminate the above problems, the cavity space is formed such that a location shifted from the mating portion, specifically, a location hidden by the engine hood is positioned on the part tension line.

  However, in the first mold and the second mold formed as described above, the mating portion is accommodated in the first mold and the second mold, and therefore when the front fender panel is released. In addition, it is conceivable that the mating portion is caught by the mold. That is, an undercut state is established.

Therefore, an injection molding apparatus having an end part release means has been proposed. The end part releasing means deforms the end part of the resin part such as the mating part so that the resin part can be released. As a result, the front fender panel is released (see, for example, Patent Document 1).
JP 2001-225367 A

  However, since the injection device disclosed in Patent Document 1 includes end part release means, the structure becomes complicated.

  Accordingly, an object of the present invention is to provide a resin part molding apparatus capable of molding a resin part that is in an undercut state with a simple structure, and an apparatus having a complicated structure when molding a resin part that is in an undercut state. It is an object of the present invention to provide a method for molding a resin component that does not require the use of a resin.

The method for molding a resin component according to the present invention has a protrusion and is molded in a cavity space formed by a plurality of molds, and the protrusion is in any one of the plurality of molds. Mold resin parts that will be undercut. The resin component molding method includes : a first mold that is one of the plurality of molds that accommodates the protrusion in an undercut state; and a protrusion molding cavity that molds a tip of the protrusion in the cavity space A slide block that is one of the plurality of molds that forms a space between the first mold and is movable in a direction relatively away from the first mold, and overlaps the first mold. the distance relative to the first mold in a direction perpendicular to the moving direction of the slide block relative to the first mold to form a cavity space other than the protrusion molding cavity out of the cavity space by the The cavity block formed by the mold 2 is filled with a heated material, and the slide block is moved when the resin component is in a contractible state as the temperature decreases. And, releasing the undercut of the protrusion relative to the first mold by the contraction of the resin component due to the temperature drop.

  In a preferred embodiment of the present invention, when the resin part has an undercut portion that is in an undercut state with respect to the slide block, the undercut state of the resin part with respect to the first mold is released and the resin part After the contraction of the slide block stops, the slide block is moved relative to the resin component such that the undercut state of the undercut portion with respect to the slide block is released.

  In a preferred embodiment of the present invention, the resin component is formed with a base point when the resin component contracts.

In a preferred embodiment of the present invention, the resin component is a front fender having a through hole through which a vehicle width lamp passes, and the base point portion is the through hole.
In a preferred embodiment of the present invention, the second mold moves away from the second mold, so that the second mold is separated from the first mold.

  Further, in the method for molding a resin component according to the present invention, it is not necessary to use an apparatus having a complicated structure when molding a resin component that is in an undercut state.

  A resin component molding apparatus 40 according to an embodiment of the present invention will be described with reference to FIGS. The resin component molding apparatus 40 of the present embodiment molds the front fender 20 of the automobile 10 as an example of a resin component.

  FIG. 1 shows an automobile 10 including a front fender 20 molded by a resin component molding apparatus 40. As shown in FIG. 1, the automobile 10 includes an engine hood 12, a front fender 20, and the like. The engine hood 12 covers an engine room (not shown) of the vehicle body 11 of the automobile 10 from above. One front fender 20 is provided on each side in the vehicle width direction with the engine hood 12 in between.

  FIG. 2 is a sectional view taken along line F2-F2 shown in FIG. FIG. 2 shows a cross section of the front fender 20 provided on the left side in the vehicle width direction in the vicinity of the mating portion 21 with the engine hood 12. FIG. 3 is a side view of the front fender 20 provided on the left side of the vehicle body.

  2 shows the vicinity of the mating portion 21 with the engine hood 12 in the front fender 20 provided on the left side of the vehicle body. The front fender 20 provided on the right side of the vehicle body may be symmetrical to the front fender 20 provided on the left side of the vehicle body in the vehicle width direction. Therefore, the front fender 20 provided on the left side of the vehicle body will be described as a representative.

  As shown in FIG. 2, the front fender 20 includes a mating portion 21, a first portion 22 that can be seen from the outside, and a second portion 23 that becomes invisible from the outside when covered by the engine hood 12. ing.

  As described above, the mating portion 21 is a portion adjacent to the edge 13 of the engine hood 12 when the engine hood 12 is closed. The first portion 22 is exposed to the outside of the vehicle body with the mating portion 21 as a boundary. The second portion 23 enters the inside of the vehicle body 11 with the mating portion 21 as a boundary. The mating portion 21 is chamfered.

  The second portion 23 extends from the mating portion 21 to the inside of the vehicle body 11. For example, a flange portion 24 is formed at the tip of the second portion 23. The flange portion 24 extends inward in the vehicle width direction, for example. The flange portion 24 extends inward in the vehicle width direction so as to face the engine hood 12.

  Since the front fender 20 is formed as described above, the shape is such that the mating portion 21 protrudes.

  Further, in the vicinity of the mating portion 21, the thickness of the front fender 20 is substantially constant. Therefore, a recessed portion 25 that is recessed corresponding to the mating portion 21 is formed inside the mating portion 21. That is, the mating portion 21 protrudes as if it is folded back.

  In other words, the front fender 20 has a shape that is folded back with the mating portion 21 as a base point. Therefore, in the front fender 20, the mating portion 21 is a protruding portion referred to in the present invention.

  As shown in FIG. 1, a vehicle width lamp 14 is provided on the side of the vehicle body 11. The vehicle width lamp 14 is exposed to the outside from the front fender 20. FIG. 3 shows the front fender 20. As shown in FIG. 3, a through hole 26 through which the vehicle width lamp 14 passes is formed in the first portion 22 of the front fender 20.

  The front fender 20 is molded by the resin component molding apparatus 40. FIG. 4 is a cross-sectional view showing the resin component molding apparatus 40. As shown in FIG. 4, the resin component molding apparatus 40 includes a base 41, a guide rail 42, a first mold 43, a slide block 44, a second mold 45, and a moving mechanism 60. Yes.

  A cavity space 50 for molding the front fender 20 is formed by the first mold 43, the slide block 44, and the second mold 45.

  FIG. 5 is an enlarged cross-sectional view showing a cavity space 50 formed by the first mold 43, the slide block 44, and the second mold 45.

  As shown in FIG. 5, the 1st type | mold 43 is located in the upper part in the figure. The second mold 45 is located below the first mold 43. The first mold 43 and the second mold 45 are stacked in the vertical direction in the figure.

  As shown in FIG. 4, a guide rail 42 is provided on the base 41. The guide rail 42 extends in the vertical direction in the drawing. The guide rail 42 passes through the first mold 43 and the second mold 45. The position of the second mold 45 with respect to the guide rail 42 is fixed by a fixing means (not shown). That is, the second mold 45 does not move.

  FIG. 6 shows a state in which the first mold 43, the second mold 45, and the slide block 44 are separated from each other. As shown in FIG. 6, relative movement of the first mold 43 along the vertical direction in the figure with respect to the second mold 45 is guided by the guide rail 42.

  As shown in FIG. 5, the slide block 44 is accommodated between the first mold 43 and the second mold 45. The cavity space 50 is a space defined between the first mold 43, the slide block 44, and the second mold 45 when they are combined with each other.

  The cavity space 50 includes a first cavity space 51, a second cavity space 52, and a third cavity space 53.

  The first cavity space 51 is a space for molding the vicinity of the mating portion 21 of the front fender 20. The first cavity space 51 is a protrusion molding cavity space as referred to in the present invention. The first cavity space 51 is formed between the first mold 43 and the slide block 44.

  The first cavity space 51 will be described in detail. The first cavity space 51 molds the mating portion 21, a range adjacent to the mating portion 21 in the first portion 22, and a range adjacent to the mating portion 21 in the second portion 23. That is, the first cavity space 51 is molded with both a part of the first part 22 and a part of the second part 23.

  As described above, the mating portion 21 is gently chamfered. Therefore, in the first mold 43, a recessed portion 54 that is recessed corresponding to the tip 27 is formed at a portion where the tip 27 of the mating portion 21 is molded. The recess 54 is formed in a substantially U-shaped cross section so as to be folded back.

  The slide block 44 has a protrusion 46 that forms the recess 25 inside the front fender 20.

  As described above, when the tip 27 of the mating portion 21 of the front fender 20 is accommodated in the first die 43, the tip 27 is caught by the first die 43. That is, the front fender 20 is in an undercut state with respect to the first mold 43.

  Further, since the slide block 44 has the protrusion 46, the front fender 20 is caught with respect to the slide block 44. That is, the front fender 20 is in an undercut state with respect to the slide block 44. The dent 25 formed by the protrusion 46 is caught on the protrusion 46 of the slide block 44. Therefore, the recessed portion 25 is an undercut portion referred to in the present invention.

  The second cavity space 52 molds the other part of the first part 22. The second cavity space 52 is formed between the first mold 43 and the second mold 45. The second mold 45 is formed with a protrusion 47 that forms the through hole 26. The protrusion 47 is located in the second cavity space 52.

  The third cavity space 53 is a space for molding the other portion of the second portion 23 and the flange portion 24. The third cavity space 53 is formed between the second mold 45 and the slide block 44.

  As shown in FIG. 4, the moving mechanism 60 includes a rod 61, a guide portion 62, and a push-up mechanism 63.

  The rod 61 is connected to the slide block. The guide part 62 is formed on the second mold 45. The guide part 62 has a guide hole 62 a that passes through the second mold 45. The rod 61 is movably accommodated in the guide hole 62a. The guide part 62 is a concept including a guide hole 62a and an edge part 62b of the guide hole 62a.

  The push-up mechanism 63 includes a push-up member 64, a support member 65, and a connecting member 66. The push-up material 64 is provided so as to be movable in the vertical direction in the drawing along the guide rail 42. The push-up material 64 is disposed below the second mold 45. A through hole 67 through which the lower end of the rod 61 passes is formed in the push-up material 64. The rod 61 passes through the through hole 67.

  The support member 65 supports the lower end of the rod 61. The support member 65 supports the rod 61 so that the rod 61 can tilt with respect to the support member 65. The support member 65 is attached to the lower surface of the push-up material 64 so as to be movable with respect to the push-up material 64.

  The connecting material 66 is connected to the first mold 43 and the push-up material 64. Therefore, when the first mold 43 moves along the guide rail 42, the push-up material 64 also moves along the guide rail 42 as the first mold 43 moves.

  That is, when the first die 43 moves in the upward direction in the figure, the push-up material 64 also moves upward. When the first mold 43 moves downward, the push-up material 64 also moves downward. As the push-up member 64 moves in the vertical direction, the rod 61 connected to the support member 65 also moves in the guide hole 62a. That is, the slide block 44 also moves.

  Here, the guide hole 62a will be described in detail. The guide hole 62a is inclined with respect to the moving direction of the first mold 43 relative to the second mold 45 (in this embodiment, the vertical direction in the figure).

  The guide hole 62a is inclined so that a space larger than the first cavity space 51 is formed between the first mold 43 and the slide block 44 as the slide block 44 moves upward. Yes. That is, the guide hole 62 a is inclined so that the slide block 44 is separated from the recessed portion 54 formed in the first mold 43.

  Specifically, the rod 61 is inclined so that the slide block 44 can move from the first position P1 to the third position P3 via the second position P2.

  As shown in FIGS. 4 and 5, the first position P <b> 1 is a position where the first cavity space 51 is formed with the first mold 43. FIG. 9 is a cross-sectional view showing a state in which the slide block 44 is at the second position P2. As shown in FIG. 9, the second position P2 is a direction perpendicular to the moving direction of the first mold 43 from the first position P1, and the tip 48 of the protrusion 46 of the slide block 44 is the first position 48. It is the position which moved the 1st distance L1 to the direction away from the dent part 54 of the type | mold 43 of FIG.

  The first distance L1 is a view from the most recessed position P4 of the recessed portion 54 of the first mold 43 (a position corresponding to the tip 27 of the mating portion 21 of the front fender 20) to the lower end edge P5 of the recessed portion 54. It is longer than the length along the middle left and right direction. That is, the length along the left-right direction in the drawing from the position P4 to the lower edge P5 is the length along the left-right direction of the portion of the front fender 20 that is undercut with respect to the first mold 43. It is. In addition, the left-right direction in the figure is a direction perpendicular to the relative movement direction of the first mold 43 and the second mold 45.

  The through hole 67 formed in the push-up material 64 has a size that allows the rod 61 to move along the moving direction of the support member 65 so as not to prevent the rod 61 from moving in the vertical direction.

  Next, a method for manufacturing the front fender 20 using the resin component molding apparatus 40 will be described.

  First, as shown in FIG. 4, the first mold 43, the second mold 45, and the slide block 44 are closed to form a cavity space 50.

  Next, the heated material is filled into the cavity space 50 by injection means (not shown). FIG. 7 shows an enlarged view of the vicinity of the mating portion 21 in the state where the cavity space 50 is filled with the material.

  While the material is warm, the first mold 43 is moved upward. In addition, a warm state is a state in which there is room for shrinkage with a decrease in temperature.

  FIG. 8 shows a state in which the first mold 43 has moved until the slide block 44 reaches the second position P2. FIG. 9 shows the moment when the slide block 44 reaches the second position P2.

  The first mold 43 stops moving at least for a predetermined time when the slide block 44 reaches the second position P2. The predetermined time is a time until the contraction of the material (front fender 20) stops as the temperature decreases.

  FIG. 10 is a cross-sectional view showing the vicinity of the mating portion 21 in a state where a predetermined time has elapsed after the slide block 44 has reached the second position P2. As shown in FIG. 10, the material (front fender 20) contracts so as to be in close contact with the slide block 44 moved to the second position P2. At this time, the material (front fender 20) contracts with the through hole 26 as a base point. The through hole 26 functions as a base point portion referred to in the present invention. The protrusion 47 functions as a base portion forming portion referred to in the present invention.

  When the material (front fender 20) contracts so as to be in close contact with the slide block 44 at the second position P2, the tip 27 of the mating portion 21 of the front fender 20 also moves to the right by a first distance L1.

  Therefore, the tip 27 does not overlap with the lower end edge P5 of the recessed portion 54 of the first mold 43 in the vertical direction. That is, since the tip 27 is not caught by the first die 43, the undercut state of the front fender 20 with respect to the first die 43 is released.

  When the predetermined time elapses, the first mold 43 is moved further upward as shown in FIG. At this time, since the material (front fender 20) is sufficiently cooled, it does not shrink any more. As the first mold 43 moves upward, the slide block 44 further moves to the right in the figure from the second position P2.

  When the slide block 44 moves further to the right in the drawing from the second position P2, the protrusion 46 of the slide block 44 moves away from the inside of the recess 25 inside the front fender 20.

  FIG. 12 is a cross-sectional view of the vicinity of the mating portion 21 in a state where the slide block 44 has reached the third position P3. The third position P <b> 3 is a position at which the protrusion 46 completely exits from the inside of the recessed portion 25 inside the front fender 20 as the slide block 44 moves. When the protrusion 46 completely comes out of the recess 25, the undercut state of the front fender 20 with respect to the slide block 44 is released.

  As described above, when the undercut state of the front fender 20 with respect to the first mold 43 and the slide block 44 is released, the front fender 20 is released.

  The cavity space 50 is formed in consideration of the shrinkage of the material (front fender 20).

  In the resin component molding apparatus 40 configured as described above, when the material (front fender 20) is in a contractible state, the slide block 44 is moved to the second position P2 to contract the front fender 20. Therefore, the undercut state of the front fender 20 with respect to the first mold 43 is released.

  That is, since the undercut state of the front fender 20 with respect to the first mold 43 is released by controlling the slide distance of the slide block 44, it is not necessary to make the mold structure complicated, and the structure of the resin component molding apparatus 40 is Be simple. Furthermore, since the production cost of the mold is reduced, the cost of the resin component molding apparatus 40 is also reduced.

  The undercut state of the front fender 20 relative to the slide block 44 is such that the slide block 44 is moved to the third position P3 after the shape of the front fender 20 is determined (after the contraction of the front fender 20 is stopped). It is canceled by.

  That is, by controlling the sliding distance and sliding timing of the slide block 44, the undercut state of the front fender 20 with respect to the slide block 44 is released, so that it is not necessary to complicate the mold structure and the structure of the resin component molding apparatus 40 Becomes simple. Furthermore, since the production cost of the mold is reduced, the cost of the resin component molding apparatus 40 is also reduced.

  Further, by using the through hole 26 as a base point for contraction of the front fender 20, the front fender 20 can be contracted efficiently and evenly.

  Further, when the front fender 20 is molded as a resin component, the partition line between the first mold 43 and the second mold 45 can be positioned in the second portion 23.

  In general, in a resin part, a position corresponding to a partition line of a mold tends to cause a step, and it tends to be difficult to be painted. For this reason, the partition lines of the first mold 43 and the second mold 45 are located in the second portion 23 as in the present embodiment, so that even if the front fender 20 has a step at a position corresponding to the partition line. Even if this occurs or is not painted, the location is not visible from the outside of the vehicle body, so the appearance of the automobile 10 is not impaired.

  Furthermore, since the through hole 26 through which the vehicle width lamp 14 passes can be used as a base point for contraction of the front fender 20, the mold structure is further simplified.

  In the present embodiment, the protrusion 47 is formed on the second mold 45, but the present invention is not limited to this. For example, the protrusion 47 may be formed on the first mold 43. Alternatively, the protrusion 47 may be formed by being divided into first and second molds 43 and 45. FIG. 13 is a cross-sectional view showing a state in which the protrusion 47 is formed on the first mold 43. FIG. 14 is a cross-sectional view showing a state in which the protrusion 47 is formed by being divided into first and second molds 43 and 45. 13 and 14, the structure other than the protrusion 47 may be the same as that in which the protrusion 47 is formed on the second mold 45.

The perspective view of a motor vehicle provided with the front fender shape | molded by the resin component molding apparatus which concerns on one Embodiment of this invention. Sectional drawing which follows the F2-F2 line | wire shown by FIG. The side view of the front fender provided in the vehicle body left side of the motor vehicle shown in FIG. Sectional drawing of the resin component molding apparatus which concerns on one Embodiment of this invention. Sectional drawing which expands and shows the cavity space shown by FIG. FIG. 6 is a cross-sectional view illustrating a state where the first mold, the second mold, and the slide block illustrated in FIG. 5 are separated from each other. FIG. 6 is an enlarged cross-sectional view showing the vicinity of a mating portion in a state where a material is filled in the cavity space shown in FIG. 5. Sectional drawing which shows the state which the 1st type | mold moved until the slide block shown by FIG. 4 reached the 2nd position. FIG. 5 is a cross-sectional view showing the vicinity of a mating portion at the moment when the slide block shown in FIG. 4 reaches a second position. Sectional drawing which shows the vicinity of the fitting part in the state which predetermined time passed after the slide block reached the 2nd position. Sectional drawing which shows the state which the 1st type | mold further moved after the slide block reached the 2nd position. Sectional drawing of the vicinity of the fitting part in the state in which the slide block reached the 3rd position. Sectional drawing which shows the state in which the protrusion was formed in the 1st type | mold. Sectional drawing which shows the state by which the protrusion was divided | segmented into the 1st, 2nd type | mold.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 14 ... Vehicle width lamp, 20 ... Front fender (resin part), 21 ... Matching part (protrusion part), 25 ... Depression part (undercut part), 26 ... Through-hole (base point part), 27 ... Tip, 40 ... Resin Component molding apparatus, 43 ... first mold, 44 ... slide block, 45 ... second mold, 47 ... projection (base point forming portion), 50 ... cavity space, 51 ... first cavity space (projection molding) Cavity space), 60 ... moving mechanism, P2 ... second position (position where the undercut state of the protrusion relative to the first mold is released), P3 ... third position (undercut state of the resin part with respect to the slide block) Is released).

Claims (5)

A resin part having a protrusion and molded in a cavity space formed by a plurality of molds and molding the resin part in which the protrusion is undercut with respect to any of the plurality of molds. A resin part molding method,
A first mold that is one of the plurality of molds that accommodates the protrusion in an undercut state, and a protrusion molding cavity space that molds the tip of the protrusion of the cavity space is the first mold. And a slide block that is one of the plurality of molds and is movable in a direction relatively away from the first mold, and overlaps with the first mold to thereby form the protrusion in the cavity space. And a second mold that forms a cavity space other than the part molding cavity space and that is relatively separated from the first mold in a direction perpendicular to the moving direction of the slide block with respect to the first mold. Filling the cavity space with heated material,
A resin component that moves the slide block when the resin component is in a contractible state due to a temperature decrease, and releases the undercut state of the protrusion with respect to the first mold by the contraction of the resin component due to the temperature decrease. the method of molding. When the resin part has an undercut portion that becomes an undercut state with respect to the slide block,
After the undercut state of the resin part with respect to the first mold is released and the shrinkage of the resin part stops, the undercut state of the undercut part with respect to the slide block is released to the resin part. 2. The method for molding a resin part according to claim 1, wherein the slide block is moved relative to the resin block. The method for molding a resin part according to claim 1, wherein a base point portion when the resin part contracts is formed on the resin part. The resin component is an automobile fender having a through hole through which a vehicle width lamp passes,
The method for molding a resin component according to claim 3, wherein the base point portion is the through hole. The method of molding a resin part according to claim 1, wherein the second mold is moved away from the second mold by moving the first mold from the second mold. .

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