JP5895776B2 - Resin parts for vehicles and manufacturing method thereof - Google Patents

Description

  The present invention relates to a vehicle resin part used for an interior / exterior part of an automobile and a method for manufacturing the same.

Generally, interior and exterior parts of automobiles (for example, bumpers and quarter trims) are provided with a panel body having a design surface that emphasizes the appearance of the design, and reinforcing ribs for ensuring the rigidity of the panel body. Yes. In addition, automobile interior / exterior parts are often resin parts for vehicles manufactured by an injection molding method in order to integrally mold a panel body and reinforcing ribs and to increase the degree of freedom of the design surface.
In order to cope with recent global environmental problems, the resin parts for vehicles are required to be further thinned and highly rigid.
For this reason, a technique has been developed that achieves a reduction in thickness and rigidity while ensuring the appearance of the design of the resin component for a vehicle (see, for example, Patent Documents 1-3).

  The technology of Patent Document 1 relates to an automobile door that is lightweight and exhibits high strength. Specifically, the vehicle exterior portion of the door body portion is configured, and the first door structure body, which is substantially entirely formed of a honeycomb structure, and the vehicle interior portion of the door body portion is configured, and substantially the entire structure is a honeycomb structure. And each honeycomb structure is sealed with a sealing plate portion from the inside and outside of the vehicle, and at least one part of the sealing plate portion includes the first door structure and the second door. It is characterized in that the structure is joined. The honeycomb structure is sealed with a sealing plate portion from the inside and outside of the vehicle, so that the rigidity can be improved by using the reinforcing rib as a closed cross section.

  Further, the technique of Patent Document 2 is an injection molded part (a cowl top cover) and an injection mold that prevent or reduce molding defects such as weld lines and flow marks, which are likely to occur in the plane portion downstream of the lattice during injection molding. It is about. Specifically, the width of the vertical beam provided in parallel with the resin flow among the horizontal beam and the vertical beam forming the lattice portion is narrower than the width of the horizontal beam. By making the width of the vertical beam narrower than the width of the horizontal beam, the flow rate of the molten resin flowing in the vertical beam cavity can be made slower than the flow rate of the molten resin flowing in the horizontal beam cavity. Therefore, the molten resin easily flows from the flat plate cavity into the vertical beam cavity and into the horizontal beam cavity, so that the molten resin flows from the vertical beam cavity and the horizontal beam cavity into the flat plate cavity. It becomes difficult to leak. As a result, it is possible to prevent molding defects such as weld lines and flow marks due to the fusion of the molten resin flowing out of the vertical beam cavity on the back side of the lattice portion and the molten resin flowing through the flat plate cavity. Can be reduced.

  The technique of Patent Document 3 is a method in which a molded product injection-molded by a fixed mold and a movable mold is released by an extrusion pin provided on the movable mold, and the molded product is fixed by the extrusion pin before the mold is opened. The release force when releasing the molded product from the movable mold matches the release force when releasing the molded product from the fixed mold while maintaining pressure contact toward the cavity surface. Open the mold until just before. Then, the mold opening is completed with the molded product attached to the movable mold, and the molded product is released from the movable mold with an extrusion pin. By reducing the mold release force of the molded product in the resin mold, it is possible to improve the mold release speed and reduce whitening due to the extrusion pin at the time of mold release.

JP 2009-262916 A JP 2008-213593 A Japanese Patent Laid-Open No. 7-323445

However, Patent Documents 1-3 have the following problems.
That is, in the technology of Patent Document 1, for example, in the first door structure, since the honeycomb structure is sealed with the sealing plate portion from the inside and outside of the vehicle, the sealing plate portion (panel) on the outside of the vehicle having a design surface. At least one of the partition wall (corresponding to the reinforcing rib) of the honeycomb structure and the sealing plate portion on the inside of the vehicle must be molded separately and then joined after molding. Therefore, in order to manufacture the 1st door structure of patent document 1, two or more shaping | molding die and a joining apparatus are needed, and an installation cost and a process man-hour increase. In addition, the weight of the sealing plate portion that seals the honeycomb structure from the inside of the vehicle increases, and it is not possible to sufficiently meet the demand for weight reduction.

  Moreover, in the technique of patent document 2, since the thickness of the other rib (horizontal beam) is made thicker than the thickness of one rib (vertical beam) among the ribs (vertical beam and horizontal beam) forming the lattice portion. The weight is increased by increasing the thickness of the other rib (horizontal crosspiece), and the request for weight reduction cannot be sufficiently met.

In the technique of Patent Document 3, a measurement detection mechanism for measuring a movable mold opening stroke is provided in the vicinity of the movable mold. The measurement detection mechanism measures the movable mold opening stroke, and this measurement. The operation of the clamping cylinder unit is controlled based on the value. In addition, another measurement detection mechanism for measuring the movement stroke of the push pin is provided in the vicinity of the push rod, and the operation of the push cylinder unit is controlled based on the measurement value measured by the measurement detection mechanism. ing. In this way, a plurality of measurement detection mechanisms and control devices are required, leading to an increase in complexity and cost of the injection molding apparatus.
In the technique of Patent Document 3, a molded product attached to a movable mold by molding shrinkage is pressed with an extrusion pin. Therefore, if the thickness of the molded product (corresponding to the panel body) is reduced, deformation or whitening due to pressing force is caused. The possibility of increased fear remains. Therefore, there is a limit to further thinning the panel body.

  The present invention has been made to solve the above-mentioned problems, and achieves thinning and high rigidity of the entire panel body and reinforcing rib with a simple structure and method while maintaining the appearance of the design surface. An object of the present invention is to provide a vehicular resin part and a method for manufacturing the same.

In order to solve the above problems, the resin component for a vehicle and the manufacturing method thereof according to the present invention have the following configurations.
(1) A resin component for a vehicle comprising a panel body having a design surface on the front surface side, and reinforcing ribs projecting from each other on the back surface side of the panel body,
The reinforcing rib has inner ribs that intersect each other, and outer ribs that are connected to the outer peripheral side end portions of the inner ribs and surround the inner ribs,
The rib height of the outer rib is lower than the rib height of the inner rib.

  In the present invention, the reinforcing rib has inner ribs that intersect with each other and outer ribs that are connected to the outer peripheral side end portions of the inner ribs and surround the inner ribs. Since the height is lower than the rib height, the outer rib can be removed from the cavity earlier than the inner rib when the vehicle resin component is taken out of the mold. Therefore, it is possible to reduce the releasing force of the reinforcing rib and to prevent the deformation of the panel body due to the releasing. As a result, in the resin component for a vehicle, it is possible to realize thinning and high rigidity of the entire panel body and the reinforcing rib.

  In the present invention, the inner rib and the outer rib constituting the reinforcing rib have a simple structure in which the rib height of the outer rib is lower than the rib height of the inner rib. As described above, two or more molds and a joining device are not required, the equipment cost and the processing man-hour are not increased, and the weight of the sealing plate portion for sealing the honeycomb structure is not increased.

  Further, in the present invention, the inner rib and the outer rib constituting the reinforcing rib have a rib height of the outer rib that is lower than the rib height of the inner rib. The molten resin is filled and solidified earlier than in the cavity. Therefore, the molten resin does not flow out from the outer rib cavity into the panel body cavity. Therefore, molding defects such as weld lines and flow marks generated by the molten resin flowing in the panel body cavity on the outer peripheral side of the outer rib and the molten resin flowing out of the outer rib cavity are prevented or reduced. Can do. Therefore, as in the technique of Patent Document 2, in order to prevent or reduce molding defects such as weld lines and flow marks in the flat plate portion (corresponding to the panel main body), the thickness of one rib (vertical beam) is the other. The thickness of the rib (horizontal crosspiece) is not increased, and the weight of the other rib (horizontal crosspiece) is not increased.

(2) In the vehicle resin part described in (1),
The rib height of the outer peripheral side end portion of the inner rib is gradually lowered toward the outer rib to be connected.

  In the present invention, since the rib height of the outer peripheral side end portion of the inner rib gradually decreases toward the outer rib to be connected, when the vehicle resin component is taken out from the mold, the outer peripheral end portion of the inner rib. Can be gradually detached from the outer rib side. Therefore, even if the inner rib is in a state of biting into the cavity, the biting state of the inner rib can be easily released by gradually separating the outer peripheral side end portion of the inner rib from the outer rib side. Therefore, sink deformation of the panel main body accompanying mold release can be more easily prevented. As a result, in the resin component for a vehicle, it is possible to further reduce the thickness and increase the rigidity of the entire panel body and the reinforcing rib.

(3) In the resin component for vehicles described in (1) or (2),
The inner rib is provided in a flat portion of the panel main body, and the outer rib is provided in the vicinity of a boundary where the panel main body changes from a flat portion to a curved portion.

In the present invention, the inner rib is provided on the flat portion of the panel body, and the outer rib is provided along the vicinity of the boundary where the panel main body changes from the flat portion to the curved portion. The tension rigidity of the panel body can be secured by the reinforcing rib. Specifically, for the flat part of the panel main body, since the rigidity of the panel main body is low, it is reinforced with an inner rib with a high rib height, and the vicinity of the boundary where the panel main body changes from the flat part to the curved part, Since the rigidity of the panel body is increased, it is sufficient to reinforce it with outer ribs having a low rib height. Therefore, with a simple structure, high rigidity can be realized by the minimum necessary reinforcing ribs according to the degree of curvature of the panel body.
In addition, by gradually lowering the rib height of the outer peripheral side end portion of the inner rib toward the outer rib to be connected, the tension rigidity of the entire panel body is made uniform. Local sink deformation can be prevented.

(4) A method for manufacturing a resin component for a vehicle according to any one of (1) to (3),
A first extrusion device for extruding the panel body on the outer peripheral side of the outer rib, and a second extrusion device for extruding the inner rib,
The first extruding device is characterized in that the resin component for a vehicle is released prior to the second extruding device.

In the present invention, a first extrusion device for extruding the panel main body on the outer peripheral side of the outer rib and a second extrusion device for extruding the inner rib are provided. The first extrusion device is more than the second extrusion device. Since the vehicle resin part is released in advance, the biting of the outer rib into the cavity is canceled by the first pushing device in advance, and then the biting of the inner rib into the cavity is set to the second pushing device. Can be released by. Therefore, the mold release force of the second extrusion device can be reduced, and the sink deformation of the panel body accompanying the mold release can be easily prevented.
Here, it is preferable that the pushing contact portion of the panel body in the first pushing device is arranged so as to surround substantially the entire circumference in the vicinity of the outer circumference of the outer rib. The biting of the outer rib into the cavity can be released substantially evenly, the release force of the second extrusion device can be further reduced, and the sink deformation of the panel body accompanying the release can be more easily prevented. Because it can. Moreover, it is preferable that a 2nd extrusion apparatus extrudes the cylindrical part formed in the intersection part of an inner rib, or the intersection part of an inner rib. By extruding the intersecting portion of the inner ribs or the cylindrical portion formed at the intersecting portion of the inner ribs, it is possible to reduce the pushing force per unit area to the panel body by dispersing the pushing force to the adjacent inner ribs. . Therefore, sink deformation of the panel main body accompanying mold release can be further prevented or reduced.

(5) In the method for manufacturing a resin component for a vehicle described in (4),
The first extrusion device and the second extrusion device are driven by the same driving body.

In the present invention, since the first extrusion device and the second extrusion device are driven by the same driving body, the difference in the extrusion timing between the first extrusion device and the second extrusion device can be kept constant. . Moreover, since the drive body of a 1st extrusion apparatus and a 2nd extrusion apparatus is common, an extrusion apparatus can also be simplified as a whole. For example, the extruding pin in the second extruding device is separated from the extruding pin abutting portion of the driving body, and the extruding timing of the extruding pin in the second extruding device is set to the extruding timing of the extruding portion in the first extruding device. Can be made slower.
Further, the first inclined block is fixed to the lower end of the base connected to the extruding pin in the second extruding device, and the second inclined block (extrusion block) is located at a position facing the first inclined block with a predetermined gap at the upper end of the driving body. It is preferable that the pin contact portion is provided so as to be movable left and right, and the first inclined block and the second inclined block are separated from each other by an inclined surface. This is because fine adjustment of the push-out timing of the push-out pin in the second push-out apparatus can be easily performed by adjusting the left / right position of the second inclined block.

  According to the present invention, there are provided a resin component for a vehicle and a method for manufacturing the same that can achieve thinning and high rigidity of the panel body and the entire reinforcing rib with a simple structure and method while maintaining the appearance of the design surface. be able to.

1 is a perspective view of a vehicle including a vehicle resin component to which an embodiment according to the present invention is applied. It is a perspective view of the semi-finished product which carried out the injection molding of the resin component for vehicles of FIG. It is a back surface perspective view in the reinforcement rib of FIG. FIG. 4 is a detailed view of part B in FIG. 3. FIG. 4 is a perspective view of an inner rib in FIG. 3. FIG. 4 is a perspective view of an intersecting portion of inner ribs in FIG. 3. It is a perspective view of the thin cylindrical body formed in the crossing part of the inner rib in FIG. It is sectional drawing of the general part of the inner rib in FIG. 3, and a panel main body. It is typical sectional drawing of the injection molding apparatus of the resin component for vehicles to which embodiment which concerns on this invention is applied. It is a top view (1 part) of the core type | mold in FIG. It is a fragmentary perspective view of the extrusion pin of the inner rib in FIG. It is typical sectional drawing in the middle of mold release in the injection molding apparatus shown in FIG. It is typical sectional drawing in the middle of mold release in the injection molding apparatus shown in FIG. FIG. 10 is a schematic cross-sectional view of mold release completion in the injection molding apparatus shown in FIG. 9.

  Next, a vehicle resin part and a method for manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the drawings.

<Structure of resin parts for vehicles>
First, the structure of a resin component for a vehicle that is an embodiment according to the present invention will be described with an example of a bumper. FIG. 1 is a perspective view of a vehicle including a vehicle resin component to which an embodiment according to the present invention is applied. FIG. 2 is a perspective view of a semi-finished product obtained by injection molding of the vehicle resin component of FIG.

  As shown in FIGS. 1 and 2, a vehicular resin part (bumper) 10 indicated by hatching surrounded by a thick line has a substantially U-shape in which both left and right ends are curved in the vehicle side surface direction. The upper end 16 of the vehicle resin component (bumper) 10 is formed with a parting portion for a radiator grille, a headlight, a fender or the like. In addition, a number plate mounting seat (near the center) and fog lamp mounting holes (both sides) are formed in the panel body 1 of the vehicle resin component (bumper) 10. Except for the mounting seats and mounting holes for these other parts, the outer surface (surface side 11 of the panel body) along the outside of the vehicle serves as a design surface, and is molded with emphasis on appearance quality (appearance). Reinforcing ribs A1, A2, A3, and A4 are formed on the back surface side 12 of the flat portion, which is a portion having a small cross-sectional curvature and low rigidity in the design surface, in a range indicated by dots surrounded by virtual lines. ing. The outer edges of the reinforcing ribs A1, A2, A3, A4 are formed in a substantially rectangular shape along the vicinity of the boundary where the panel body 1 changes from a flat portion to a curved portion. A polypropylene resin material is used for the resin material used for the vehicle resin component (bumper) 10 in view of injection moldability and cost. Further, a filler such as talc or an elastomer may be added to the polypropylene resin material in accordance with the requirements for rigidity and impact resistance. Further, the resin material may contain glass fiber or carbon fiber, or may contain a reprocessing material.

As shown in Fig. 2, the resin fluidity during injection molding is used to ensure the appearance of the design surface, reduce the thickness of the component plate, increase the rigidity of the entire component, and prevent molding defects such as flow marks. For example, a plurality of resin injection portions R1 to R6 are provided in the upper end 16, the lower end 14 and the fog lamp mounting hole 15 of the panel body. And resin injection | pouring part R1-R6 is removed after injection molding.
Further, in the panel body 1, since the flat part from the left and right ends of the license plate mounting seat to the side of the vehicle side surface and the flat part of the vehicle side surface are portions having a small cross-sectional curvature and low tension rigidity, A plurality of reinforcing ribs A1, A2, A3, and A4 described below are formed on the rear surface side 12 of the rear surface.

<Structure of reinforcing rib>
Next, the structure of the reinforcing ribs A1, A2, A3, and A4 projecting from the back side 12 of the panel body 1 will be described. FIG. 3 shows a rear perspective view of the reinforcing rib of FIG. FIG. 4 shows a detailed view of a portion B in FIG. FIG. 5 shows a perspective view of the inner rib in FIG. FIG. 6 shows a perspective view of the intersection of the inner ribs in FIG. FIG. 7 shows a perspective view of a thin cylindrical body formed at the intersection of the inner ribs in FIG. FIG. 8 is a sectional view of the general portion of the inner rib and the panel body in FIG.

  As shown in FIG. 3, on the back surface side 12 of the panel body 1, there are inner ribs 2 that intersect each other, and a substantially rectangular outer rib that is connected to the outer peripheral side end 24 of the inner rib 2 and surrounds the inner rib 2. 3 are projectingly provided. Reinforcing ribs A1, A2, A3, and A4 are provided. The inner rib 2 includes a general portion 21, a crossing portion 22, a cylindrical portion 23, and an outer peripheral side end portion 24. The inner ribs 2 radially intersect on the inner peripheral side of the outer ribs 3 to form a plurality of honeycomb shapes. The honeycomb shape of the inner rib 2 is regularly formed on the back surface side 12 of the panel body 1 over a predetermined range. The general part 21 is a basic rib constituting a honeycomb shape. The intersecting portion 22 has a rib height lower than that of the general portion 21 at a location where three adjacent general portions 21 intersect. The cylindrical part 23 is an intersection part which has the cylindrical body provided in the position spaced apart by predetermined distance among the intersection parts 22 of a honeycomb shape. Extrusion pins in a first extrusion device to be described later abut on the cylindrical portion 23. Therefore, the predetermined distance at which the cylindrical portion 23 is provided is set to a length that does not cause deformation, whitening or the like on the surface side 11 of the panel body 1 due to the pushing force of the pushing pin. The outer peripheral side end 24 is a rib that connects the intersecting portion 22 or the cylindrical portion 23 and the outer rib 3. As for the inner rib 2 and the outer rib 3, the base end part is connected to the panel main body 1, and the front-end | tip part is open | released.

  As shown in FIG. 4, the rib height of the outer peripheral side end portion 24 is formed so as to gradually decrease toward the outer rib 3 connected from the intersecting portion 22 or the cylindrical portion 23. The rib height at the connection point with the outer rib 3 at the outer peripheral side end 24 is equal to the rib height H4 of the outer rib 3. The rib height H4 of the outer rib 3 is preferably set to ½ or less of the rib height H1 of the general portion 21. For example, if the rib height H1 of the general portion 21 is about 5 mm, the rib height H4 of the outer rib 3 is preferably about 2 mm. Thus, by making the rib height H4 of the outer rib 3 lower than the rib height H1 of the general portion 21, it is easy to release the biting of the inner rib 2 into the cavity at the time of mold release after injection molding. ing. Further, by forming the rib height of the outer peripheral side end portion 24 so as to gradually decrease toward the outer rib 3 connected from the intersecting portion 22 or the cylindrical portion 23, at the time of mold release after injection molding, The panel body 1 on the outer peripheral side of the outer rib 3 is not easily deformed locally. Here, the outer rib 3 is formed in a linear shape, but is not necessarily limited to a linear shape. The outer rib 3 may be provided along the vicinity of the boundary where the panel body 1 changes from a flat portion to a curved portion (including a ridge line), and may be formed in a stepped shape or a curved shape. In short, the flat portion of the panel body 1 is low in tension rigidity, so it is reinforced by the inner rib 2 having a high rib height, and the vicinity of the boundary where the panel body 1 changes from a flat portion to a curved portion (including a ridgeline). Since the tension rigidity of the panel body 1 is increased, it is sufficient to reinforce with the outer rib 3 having a low rib height.

  As shown in FIG. 5, bending portions C and D are formed in the intersecting portion 22 and the tubular portion 23 where the inner ribs 2 intersect. At the location of the bent portion C, the general portions 21 of the three inner ribs 2 intersect at one location where the rib height is lowered to form an intersecting portion 22. Moreover, in the location of the bending part D, the general part 21 of the three inner ribs 2 intersects with the thin cylindrical body 22 </ b> B whose rib height is lowered to form a cylindrical part 23. Therefore, on the back surface side 12 of the panel body, the bent portion C formed at the intersection 22 where the general portion 21 of the inner rib 2 directly intersects, or the general portion 21 of the inner rib 2 is formed with the thin cylindrical body 22B. A loop shape (here, a honeycomb shape) is formed that is closed via a bending portion D formed at an intersecting portion. By forming the bent portions C and D in the intersecting portion 22 and the cylindrical portion 23 where the inner ribs 2 intersect, the load acting on one place of the panel body 1 is distributed to the entire reinforcing ribs through the surrounding inner ribs 2. Can be made. Therefore, the panel body 1 and the reinforcing rib can be thinned and highly rigid at the same time. Further, by forming the bent portions C and D in the intersecting portion 22 and the cylindrical portion 23 where the inner ribs 2 intersect, the biting force acting on the panel body 1 at the time of mold release is dispersed throughout the reinforcing ribs. You can also. Therefore, sink deformation of the panel body at the time of mold release can be effectively prevented.

  As shown in FIG. 6, the rib height H <b> 2 of the wall portion 222 in the intersecting portion 22 is lower than the rib height H <b> 1 of the wall portion 213 in the general portion 21. Therefore, an inclined portion 212 that is inclined from the distal end portion 211 of the general portion 21 toward the distal end portion 221 of the intersecting portion 22 is formed on the inner rib 2. And the notch shape is comprised between the general part 21 and the crossing part 22 of the inner rib 2 by forming the inclination part 212 extended in 3 directions centering | focusing on the front-end | tip part 221 of the crossing part 22. FIG. Yes. This notch shape is a flexible portion C that can be elastically deformed. The length j1 and the notch depth (H1-H2) of the inclined portion 212 are set to such an extent that the stress is excessively concentrated in the notch shape and the bending portion C is not plastically deformed under the load condition set on the basis of the component strength. For example, the length j1 of the inclined portion 212 is preferably about 1.4 times or more the notch depth (H1-H2). At this time, the inner rib 2 has a thickness t of about 0.5 mm and a rib height H1 of the tip end portion 211 of about 5.0 mm. In addition, since the thickness of the intersection part 22 becomes thicker than the thickness of the general part 21, even if stress concentrates on the notch shape, it tends to be difficult to break.

As shown in FIG. 7, in the cylindrical part 23, the general part 21 of the inner rib 2 is connected to the thin-walled cylindrical body 22B. The tip 221B of the thin cylindrical body 22B is open. Further, the hollow portion 223 </ b> B on the inner peripheral side of the thin cylindrical body 22 </ b> B reaches the back surface side 12 of the panel body 1. The thickness q of the thin cylindrical body 22B is thinner than the thickness t of the general portion 21 of the reinforcing rib.
Further, the rib height H3 of the tip portion 221B in the thin cylindrical body 22B is lower than the rib height H1 of the tip portion 211 in the general portion 21. Therefore, an inclined portion 212B that is inclined from the distal end portion 211 of the general portion 21 toward the distal end portion 221B of the thin cylindrical body 22B is formed. And the notch shape is comprised between the general part 21 of the inner rib 2, and the thin cylindrical body 22B by the inclination part 212B extending in 3 directions centering on the thin cylindrical body 22B. This notch shape is a flexible portion D that can be elastically deformed. The bending part D can be bent by elastic deformation in the radial direction of the thin cylindrical body 22B and elastic deformation by expansion of the inclined part 212B. The thickness q of the thin-walled cylindrical body 22B, the length j2 of the inclined portion 212B, and the notch so that the stress is excessively concentrated in the notch shape under the load conditions set on the basis of the component strength and the bent portion D is not plastically deformed. Set the depth (H1-H3). For example, the thickness q of the thin cylindrical body 22B is preferably about ½ of the thickness t of the general portion 21 of the inner rib 2. The length j2 of the inclined portion 212B is preferably about 1.2 times or more the notch depth (H1-H3). At this time, the inner rib 2 has a thickness t of about 0.5 mm, and the rib height H1 of the distal end portion 211 of the general portion 21 is about 5.0 mm.

  As shown in FIG. 8, the base end portion 214 of the general portion 21 of the inner rib 2 is connected to the back surface side 12 of the panel main body 1, and the panel main body 1 and the inner rib 2 are integrally formed. The wall thickness T of the main body 13 in the panel main body 1 is preferably at least three times the wall thickness t of the wall 213 in the general portion 21 of the inner rib 2. This is because sink marks are less likely to occur on the surface side 11 of the panel body 1 corresponding to the general portion 21 of the inner rib 2 during injection molding. When the wall thickness T of the main body 13 is reduced, the tension rigidity of the panel main body 1 is lowered, so that the rib height H1 of the inner rib 2 needs to be increased.

<Overall structure of injection molding device>
Next, the overall structure and function of the injection molding apparatus 100 for manufacturing the vehicle resin component according to the present embodiment will be described. FIG. 9 is a schematic cross-sectional view of an injection molding apparatus for resin parts for vehicles applied to the embodiment according to the present invention. FIG. 10 shows a top view (part 1) of the core type in FIG. FIG. 11 is a partial perspective view of the inner rib push pin in FIG.

As shown in FIG. 9, the injection molding apparatus 100 includes a mold cavity 4, a core mold 5, a reinforcing rib cavity mold 6, and an extrusion device 7. Here, the extrusion device 7 includes a first extrusion device 71, a second extrusion device 72, and a driving body 74 common to them.
The mold 4 includes a cavity 41 and a cooling pipe 42 on the panel body surface side 11 of the vehicle resin component 10. The core mold 5 includes a molding surface 51 on the panel main body back side 12 of the vehicle resin component 10 and a cooling pipe 52. A recess 53 is formed at the upper end of the core mold 5, and the reinforcing rib mold 6 is nested. In addition, an extruding portion 71A of the first extruding device 71 is inserted in the upper end of the core die 5 so as to be movable up and down, adjacent to the left and right ends of the reinforcing rib cabinet 6. The reinforcing rib mold 6 includes a molding surface 61 on the back surface 12 of the panel body of the vehicle resin component 10, a cavity 62 for the general portion 21 and the intersecting portion 22 of the inner rib 2, and a cylindrical portion 23 of the inner rib 2. For the outer rib 3, and a cooling pipe 65. An extrusion pin 72A of the second extrusion device 72 is inserted into the reinforcing rib cabinet 6 at a position corresponding to the cylindrical portion 23 so as to be movable up and down. At the lower end of the core mold 5, an escape portion 54 that allows the second extrusion device 72 to move up and down is formed. The 2nd extrusion apparatus 72 is provided with the base 72B which connects the extrusion pin 72A, and the 1st inclination block 72C is being fixed to the lower end of the base 72B. A first inclined surface 72D is formed at the lower end of the first inclined block 72C. On the other hand, a leg portion 71 </ b> B connected to the driving body 74 is extended below the pushing contact portion 71 </ b> A of the first pushing device 71. A second inclined block 73 is fastened to the upper end of the driving body 74 so as to be capable of adjusting the position so as to face the first inclined block 72C. At the upper end of the second inclined block 73, a first inclined surface 72D formed at the lower end of the first inclined block 72C and a second inclined surface having a predetermined gap are formed. The predetermined gap can be changed by adjusting the left and right positions of the second inclined block 73.

  Here, the cavity mold 6 for reinforcing ribs is made of a zinc alloy casting (for example, ZAS (Mitsui Metals) with high thermal conductivity and good machinability as compared with the cavity mold 4 and the core mold 5 made of high-strength alloy steel. The product name of Mining Co., Ltd.)) The composition of the zinc alloy is, for example, about 4% Al, about 3% Cu, about 0.05% Mg, and the balance Zn. The thermal conductivity is about 2.5 to 4 times higher than that of ordinary alloy steel. By increasing the thermal conductivity of the reinforcing rib mold 6, the solidification timing of the reinforcing ribs can be advanced to prevent sinking on the panel main body surface side. Further, by forming the reinforcing rib cavity mold 6 made of cast zinc alloy having good machinability, the processing conditions of the reinforcing rib cavity groove are improved, and the reinforcing ribs (inner rib 2 and outer rib 3) are made thinner. Easy to do. The rib cavity has a tapered draft angle (for example, about 30 minutes).

  Further, the cooling circuit of the reinforcing rib cabinet 6 is preferably controlled independently of the cabinet 4 and core 5 cooling circuits. Specifically, the releasability can be improved by controlling the cooling temperature of the reinforcing rib mold 6 so as to suppress the molding shrinkage of the reinforcing ribs (the inner rib 2 and the outer rib 3). For example, the mold shrinkage amount of the reinforcement ribs (inner rib 2 and outer rib 3) is compared with the mold shrinkage amount of the panel body 1 by making the temperature of the reinforcement rib side higher than the temperature of the panel body side at the time of mold release. Can be relatively reduced. By providing a difference in molding shrinkage between the reinforcing ribs (inner ribs 2 and outer ribs 3) and the panel body 1, mold biting of the reinforcing ribs (inner ribs 2 and outer ribs 3) is reduced, and the mold release property is reduced. Can be improved.

  As shown in FIG. 10, the first extrusion device is inserted into the core mold 5 so that a substantially rectangular reinforcing rib mold 6 is inserted and surrounds substantially the entire circumference in the vicinity of the outer periphery of the reinforcing rib mold 6. The pushing contact portion 71A (71A1, 71A2, 71A3, 71A4) in 71 is arranged in four parts. Each of the pushing contact portions 71A is formed in a substantially L shape and is arranged symmetrically. Further, as shown in FIG. 11, the cavities 63 for the cylindrical portion are arranged in a staggered manner at a predetermined interval. An extruding pin 72A (71A1, 71A2, 71A3, 71A4, 71A5, 71A6, 71A7) of the second extruding device 72 that extrudes the cylindrical portion is in contact with the tip of the cavity 63 for each cylindrical portion. Here, the extrusion contact portion 71A (71A1, 71A2, 71A3, 71A4) in the first extrusion device 71 is from the extrusion pin 72A (71A1, 71A2, 71A3, 71A4, 71A5, 71A6, 71A7) of the second extrusion device 72. Since it rises in advance, the biting of the outer rib 3 into the cavity 64 can first be released substantially evenly, and the mold release force of the second extruding device 72 thereafter can be reduced. As a result, the sink deformation of the panel body 1 due to mold release can be easily prevented.

<Operation method of extrusion device>
Next, in the injection molding apparatus 100 for manufacturing the resin component 10 for a vehicle, an operation method for releasing from the core mold 5 and the reinforcing rib mold 6 after the injection molding will be described. 12 and 13 are schematic cross-sectional views in the middle of mold release in the injection molding apparatus shown in FIG. FIG. 14 is a schematic cross-sectional view of completion of mold release in the injection molding apparatus shown in FIG.

  As shown in FIG. 12, after injection molding of the vehicle resin component 10, the mold 4 and the core mold 5 are separated by a predetermined distance in order to take out the vehicle resin component from the injection molding apparatus 100. After the cavity mold 4 and the core mold 5 are separated from each other, the drive body 74 in the extrusion device 7 is raised in the direction of the arrow S1. As the driving body 74 rises, the pushing portion 71A in the first pushing device 71 rises. The amount of rise at that time is such that the outer rib 3 is detached from the cavity 64 for the outer rib. At this stage, since the second extrusion device 72 does not rise, the general portion 21, the intersecting portion 22, and the tubular portion 23 of the inner rib 2 remain fitted in the cavities 62 and 63. At this time, in the vicinity of the outer rib 3, a slight back-slip phenomenon occurs in the panel body 1.

  Next, as shown in FIG. 13, the drive body 74 in the extrusion apparatus 7 is further raised in the direction of the arrow S2. When the first inclined block 72C fixed to the lower end of the base 72B of the second push-out device 72 and the second inclined block 73 fastened to the upper end of the driving body 74 abut on the respective inclined surfaces 72D and 73A. As the drive body 74 rises in the direction of the arrow S2, the push pin 72A in the second push device 72 rises. The pushing contact portion 71A in the first pushing device 71 and the pushing pin 72A in the second pushing device 72 rise in synchronization. As the push-out pin 72 </ b> A rises in the second push-out device 72, the general portion 21, the intersecting portion 22, and the tubular portion 23 of the inner rib 2 are pushed out from the cavities 62 and 63 together with the panel body 1. At this time, the extruding force for extruding the cylindrical portion 23 of the inner rib 2 by the extruding pin 72A in the second extruding device 72 is such that the outer rib 3 and its outer peripheral side are separated from the cavity 64 and the molding surface 61 for the outer rib in advance. Since it is molded, it is less than when it is extruded at once. Therefore, sink deformation of the panel body 1 due to extrusion can be prevented or reduced.

  Next, as shown in FIG. 14, the drive body 74 in the extrusion apparatus 7 is further raised in the direction of the arrow S3. As the drive body 74 rises, the pushing portion 71A in the first pushing device 71 and the pushing pin 72A in the second pushing device 72 further rise in synchronization. The amount of rise at that time is such that the general portion 21 of the inner rib 2 is disengaged from each cavity 62. As a result, the panel body 1, the inner rib 2 and the outer rib 3 are released from the cavities 62, 63, 64 and the molding surfaces 61, 51. In the extrusion process, the panel body 1 is slightly reversely slid in the vicinity of the outer rib 3, but there is a curved portion (including a ridgeline) of the panel body 1 in the vicinity of the outer peripheral side of the outer rib 3. Since the rigidity is high, the panel body 1 after releasing the mold is free from the back-sliding phenomenon and has no sink deformation.

<Effect>
As described above in detail, according to the resin component for a vehicle that is the embodiment of the present invention, the reinforcing ribs A1, A2, A3, and A4 include the inner rib 2 that intersects each other and the outer periphery of the inner rib 2. The outer rib 3 is connected to the side end portion 24 and surrounds the inner rib 2, and the rib height H 4 of the outer rib 3 is lower than the rib height H 1 of the inner rib 2. When taking out from the mold, the outer rib 3 can be separated from the outer rib cavity 64 earlier than the inner rib 2. Therefore, the mold release force of the reinforcing rib can be reduced, and the sink deformation of the panel body 1 accompanying the mold release can be prevented. As a result, in the vehicle resin component 10, it is possible to reduce the thickness and increase the rigidity of the entire panel body 1 and the reinforcing ribs A1, A2, A3, and A4.

  Further, according to the present embodiment, the rib height H4 of the outer rib 3 out of the inner rib 2 and the outer rib 3 constituting the reinforcing ribs A1, A2, A3, A4 is set to be higher than the rib height H1 of the inner rib 2. Since it has a simple structure of lowering, it does not require two or more molds and a joining device as in the technique of Patent Document 1, and the honeycomb structure is not increased in equipment cost and processing man-hours. There is no increase in weight due to the sealing plate portion to be sealed.

  Further, according to the present embodiment, the rib height H4 of the outer rib 3 out of the inner rib 2 and the outer rib 3 constituting the reinforcing ribs A1, A2, A3, A4 is set to be higher than the rib height H1 of the inner rib 2. By making it lower, the outer rib cavity 64 is filled with the molten resin and solidified earlier than the inner rib cavity 62. Therefore, the molten resin does not flow out from the outer rib cavity 64 into the panel body cavity 41. Therefore, it is possible to prevent molding defects such as weld lines and flow marks generated when the molten resin flowing through the panel body cavity 41 on the outer peripheral side of the outer rib 3 joins with the molten resin flowing out of the outer rib cavity 64 or Can be reduced. Therefore, as in the technique of Patent Document 2, in order to prevent or reduce molding defects such as weld lines and flow marks in the flat plate portion (corresponding to the panel main body), the thickness of one rib (vertical beam) is the other. The thickness of the rib (horizontal crosspiece) is not increased, and the weight of the other rib (horizontal crosspiece) is not increased.

  Further, according to the present embodiment, the rib height of the outer peripheral side end portion 24 of the inner rib 2 gradually decreases toward the outer rib 3 to be connected, and therefore when the vehicle resin component 10 is taken out from the mold. The outer peripheral side end 24 of the inner rib 2 can be gradually detached from the outer rib 3 side. Therefore, even if the inner rib 2 is biting into the cavity 62, the biting state of the inner rib 2 can be easily achieved by gradually separating the outer peripheral end 24 of the inner rib 2 from the outer rib 3 side. It can be released. Therefore, sink deformation of the panel main body 1 due to mold release can be more easily prevented. As a result, in the vehicle resin component 10, it is possible to further reduce the thickness and increase the rigidity of the entire panel body 1 and the reinforcing ribs A1, A2, A3, and A4.

Further, according to the present embodiment, the inner rib 2 is provided in the flat portion of the panel body 1 and the outer rib 3 is provided along the vicinity of the boundary where the panel body 1 changes from the flat portion to the curved portion. In the resin part 10 for use, the rigidity of the panel body 1 can be secured with the minimum necessary reinforcing ribs. Specifically, the flat portion of the panel main body 1 is reinforced by the inner rib 2 having a high rib height H1 because the tension rigidity of the panel main body 1 is low, and the panel main body 1 changes from the flat portion to the curved portion. In the vicinity of the boundary, since the tension rigidity of the panel main body 1 is increased, it is sufficient to reinforce with the outer rib 3 having a low rib height H4. Therefore, with a simple structure, high rigidity can be realized by the minimum necessary reinforcing ribs according to the degree of curvature of the panel body.
Further, by gradually lowering the rib height of the outer peripheral side end 24 of the inner rib 2 toward the outer rib 3 to be connected, the tension rigidity of the entire panel body 1 is made uniform. It is possible to prevent local sink deformation of the panel main body 1.

  Moreover, according to the manufacturing method of the resin component 10 for vehicles which is other embodiment, the 1st extrusion apparatus 71 which extrudes the panel main body 1 on the outer peripheral side of the outer rib 3, and the cylindrical part 23 of the inner rib 2 are provided. A first extruding device 72 for extruding, and the first extruding device 71 releases the resin component 10 for the vehicle prior to the second extruding device 72, so that it enters the cavity 64 of the outer rib 3 in advance. After the biting of the inner rib 2 is released by the first pushing device 71, the biting of the inner rib 2 into the cavity 62 can be released by the second pushing device 72. Further, by extruding the cylindrical portion 23 formed at the intersecting portion of the inner ribs 2, the pushing force can be distributed to the adjacent inner ribs 2 to reduce the pushing force per unit area on the panel body 1. . Therefore, the sink deformation of the panel main body 1 accompanying mold release can be further prevented or reduced. Therefore, the mold release force of the second extrusion device 72 can be reduced, and the sink deformation of the panel body 1 accompanying the mold release can be easily prevented. Further, since the pushing portion 71A of the panel body 1 in the first pushing device 71 is arranged so as to surround substantially the entire circumference in the vicinity of the outer circumference of the outer rib 3, the biting of the outer rib 3 into the cavity 64 is performed. Can be released substantially evenly, the releasing force of the second extrusion device 72 can be further reduced, and the sink deformation of the panel body 1 accompanying the releasing can be more easily prevented.

According to another embodiment, since the first extrusion device 71 and the second extrusion device 72 are driven by the same driving body 74, the extrusion of the first extrusion device 71 and the second extrusion device 72 is performed. The timing difference can be kept constant. Moreover, since the drive body 74 of the 1st extrusion apparatus 71 and the 2nd extrusion apparatus 72 is common, the extrusion apparatus 7 can also be simplified as a whole. For example, the pushing pin 72A in the second pushing device 72 is separated from the pushing pin abutting portion of the driving body 74, and the pushing timing of the pushing pin 72A in the second pushing device 72 is set in the first pushing device 71. It can be made later than the extrusion timing of the extrusion contact portion 71A.
Further, the first inclined block 72C is fixed to the lower end of the base 72B connected to the extruding pin 72A in the second extruding device 72, and the upper end of the driving body 74 is opposed to the first inclined block 72C with a predetermined gap. The second inclined block 73 (pushing pin contact portion) is movably provided, and the first inclined block 72C and the second inclined block 73 are separated from each other by the inclined surfaces 72D and 73A. Fine adjustment of the push-out timing of the push-out pin 72A at 72 can be easily performed by adjusting the left and right position of the second inclined block 73.

The embodiment described above can be changed without changing the gist of the present invention.
In the above embodiment, the vehicle resin component is applied to the bumper, but the present invention is not limited to this. For example, the present invention can be applied to various resin parts such as a fender panel that is an exterior part and a quarter trim that is an interior part.
Moreover, in the said embodiment, although the extrusion pin of the 2nd extrusion apparatus was provided so that it might contact | abut to the cylindrical part of an inner rib, it is not restricted to this. For example, you may provide so that it may contact | abut the cross | intersection part and internal part of an inner rib.

  INDUSTRIAL APPLICABILITY The present invention can be used particularly as a vehicle resin part used for an interior / exterior part of an automobile and a manufacturing method thereof.

DESCRIPTION OF SYMBOLS 1 Panel main body 2 Inner rib 3 Outer rib 4 Cavity type 5 Core type 6 Reinforcement rib Cavity type 7 Extruder 10 Vehicle resin part 11 Panel main body surface 12 Back side of panel main body 21 Inner rib general part 22 Inner rib 23 of the inner rib 24 outer peripheral side end portion of the inner rib 71 first extrusion device 72 second extrusion device 74 driving body 100 injection molding device A1 to A4 reinforcing rib

Claims (5)

A vehicle resin component comprising a panel body having a design surface on the front surface side, and reinforcing ribs protruding while crossing each other on the back surface side of the panel body,
The reinforcing rib has an inner rib in which a notch shape is formed between a general part and an intersection where the general part intersects each other, and the notch shape is a flexible part that can be elastically deformed, and the inner rib An outer rib connected to the outer peripheral end of the inner rib to surround the inner rib,
A vehicle resin component, wherein a rib height of the outer rib is lower than a rib height of a general portion of the inner rib. In the resin component for vehicles according to claim 1,
A resin component for a vehicle, wherein a rib height at an outer peripheral side end portion of the inner rib gradually decreases toward the outer rib to be connected. In the resin component for vehicles described in Claim 1 or Claim 2,
The vehicular resin part, wherein the inner rib is provided in a flat portion of the panel main body, and the outer rib is provided along a vicinity of a boundary where the panel main body changes from a flat portion to a curved portion. A method for manufacturing a resin component for a vehicle according to any one of claims 1 to 3,
A first extrusion device for extruding the panel body on the outer peripheral side of the outer rib, and a second extrusion device for extruding the inner rib,
The method for producing a resin component for a vehicle, wherein the first extrusion device releases the resin component for a vehicle prior to the second extrusion device. In the manufacturing method of the resin component for vehicles described in Claim 4,
The method of manufacturing a resin component for a vehicle, wherein the first extrusion device and the second extrusion device are driven by the same driving body.

Images