JP2014113769A - Resin molding and vehicle lighting fixture component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve moldability.SOLUTION: A cavity 103 of a mold 100 having a first die 101 and a second die 102 is filled with a molten resin. The molten resin is cooled, molded and bent in a predetermined direction to form bent parts 5, 5. Engaging parts 6, 6... project from the bent parts. An engaging part is engaged with at least one of the first die and the second die when cooling the molten resin. The engaging part is inclined in a direction of deformation due to shrinkage when the bent parts are cooled.

Description

  The present invention relates to a technical field of a resin molded product having a bent portion that is molded by a mold and bent in a predetermined direction, and a vehicular lamp part.

JP 2009-102581 A

  Examples of vehicle lamp parts used as parts for vehicle lamps include a lamp housing in which a light source is disposed, a reflector that reflects light emitted from the light source, and an extension for improving the appearance by shielding the internal structure. There are various things such as.

  Among such vehicle lamp parts, there is one in which a molten resin filled in a cavity of a mold having a first mold and a second mold is cooled and molded as a resin molded product (for example, Patent Documents). 1).

  Patent Document 1 discloses a technique in which vehicle lamp parts such as a reflector and an extension are molded from a resin material such as polybutylene terephthalate (PBT).

  By the way, the vehicular lamp part molded as a resin molded article as described above is molded by cooling the molten resin filled in the cavity of the mold, and thus is likely to shrink during cooling. In particular, when a crystalline resin material such as polybutylene terephthalate is used as the resin material, there is a risk of significant shrinkage during cooling.

  On the other hand, since the vehicular lamp part has various functions and is formed in various shapes, it is often provided as a bent part in which a part is bent in a predetermined direction.

  Accordingly, when shrinkage occurs during cooling of the molten resin, a force in a direction in which the curvature increases in the bent portion due to the shrinkage occurs. At this time, in the state where the mold is not opened, the vehicle lamp component to be molded is not deformed by the force generated in the bent portion, but the first mold (core mold) and the second mold (cavity mold). ) When the mold is opened, deformation causes deformation of the bent portion in a direction in which the curvature increases, and the second mold rubs against the vehicle lamp component when the mold is opened. There is a risk that the lamp parts are damaged and the formability is lowered.

  Accordingly, it is an object of the resin molded product and vehicle lamp part of the present invention to overcome the above-described problems and improve moldability.

  In order to solve the above-described problems, the resin molded product is a bent portion in which a molten resin filled in a cavity of a mold having a first mold and a second mold is cooled and molded and bent in a predetermined direction. A resin molded product having an engagement portion that is engaged with at least one of the first mold and the second mold when the molten resin is cooled and protrudes from the bent portion. The portion is inclined with respect to the deformation direction of the deformation caused by the contraction during cooling of the bent portion.

  In order to solve the above-described problem, a vehicular lamp component is a bent product in which a molten resin filled in a cavity of a mold having a first mold and a second mold is cooled and molded and bent in a predetermined direction. A vehicle lamp part that is used as a part of a vehicle lamp having a portion and engages with at least one of the first mold or the second mold when the molten resin is cooled and protrudes from the bent part. Engaging portions are provided, and the engaging portions are inclined with respect to the deformation direction of the deformation caused by the contraction during cooling of the bent portion.

  Therefore, in the resin molded product and the vehicle lamp part, the bent portion is caused by the engagement of the engaging portion with at least one of the first die and the second die when the molten resin is cooled, and due to the shrinkage of the molten resin. Is prevented from being deformed.

  The resin molded product of the present invention is a resin molded product having a bent portion that is formed by cooling and molding a molten resin filled in a cavity of a mold having a first mold and a second mold and bending it in a predetermined direction. An engaging portion that is engaged with at least one of the first mold and the second mold and protrudes from the bent portion when the molten resin is cooled is provided, and the engaging portion cools the bent portion. It is characterized by being inclined with respect to the deformation direction of the deformation caused by the shrinkage at the time.

  Therefore, since the deformation of the bent portion at the time of cooling the molten resin is prevented by the engaging portion, the deformation of the bent portion due to the shrinkage of the molten resin when the first mold and the second mold are opened is prevented. Scratching due to contact of the bent portion with the mold is prevented, and the moldability of the resin molded product can be improved.

  In the invention described in claim 2, the surface of the molten resin that is in contact with the second mold is formed as a design surface, and the engaging portion is provided on the surface opposite to the design surface. Features.

  Therefore, the moldability of the resin molded product can be improved without impairing the good design of the resin molded product.

  In the invention described in claim 3, a recess is formed in the first mold, and the first mold and the second mold are closed or opened by being engaged with the recess during the cooling. The present invention is characterized in that a floating prevention protrusion is provided that protrudes in a direction different from the direction of separation at the time.

  Therefore, since the floating prevention protrusion prevents the resin molded product from being separated from the second die, the engagement state of the engagement portion with the mold is not released, and the good function of the engagement portion is exhibited. Scratches due to contact of the resin molded product with the mold can be prevented, and the moldability of the resin molded product can be improved.

  In the invention described in claim 4, the mold moves in the direction of contact with the first mold when the first mold and the second mold are closed or opened. A possible protrusion mold is provided, and an engagement recess for engaging the engagement portion is formed in the protrusion mold.

  Accordingly, the protruding die can be used as an eject pin, and a dedicated eject pin is not required, and the mold structure can be simplified while ensuring good moldability of the resin molded product.

  The vehicular lamp component of the present invention has a bent portion in which a molten resin filled in a cavity of a mold having a first mold and a second mold is cooled and molded and bent in a predetermined direction. A vehicle lamp part used as a part of the vehicle is provided with an engaging part that is engaged with at least one of the first mold or the second mold and protrudes from the bent part when the molten resin is cooled. The engaging portion is inclined with respect to a deformation direction of deformation caused by contraction of the bent portion during cooling.

  Therefore, since the deformation of the bent portion during cooling of the molten resin is prevented by the engaging portion, the bent portion is not deformed when the first mold and the second mold are opened, and the bent portion comes into contact with the mold. Scratching is prevented, and the moldability of the resin molded product can be improved.

2 to 7 show an embodiment of the present invention, and this figure is a schematic perspective view of a resin molded product. It is an expanded sectional view which follows the II-II line of FIG. It is a conceptual diagram which shows the engaging part provided in the bending part. The structure of a metal mold | die is shown with FIG.5 and FIG.6, This figure is a schematic sectional drawing in alignment with the IV-IV line | wire of FIG. It is a schematic sectional drawing in alignment with the VV line of FIG. It is a schematic sectional drawing which follows the VI-VI line of FIG. It is a schematic sectional drawing which shows the modification of a metal mold | die.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated with reference to an accompanying drawing.

<Structure of resin molded product (vehicle lamp parts)>
First, the structure of the resin molded product 1 molded as a vehicle lamp part will be described (see FIGS. 1 to 3).

  The resin molded product 1 is formed by injection molding, for example, from a crystalline resin material such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyacetal (POM), or a synthetic resin material thereof. The resin molded product 1 is, for example, a vehicle lamp part used as a part of a vehicle lamp, and is molded as an extension for, for example, improving the appearance by shielding the internal structure of the vehicle headlamp. .

  The resin molded product 1 has a horizontally long outer frame portion 2, a shielding surface portion 3 positioned inside the outer frame portion 2, and an annular projecting portion 4 positioned inside the shielding surface portion 3 (FIG. 1). reference).

  The outer frame portion 2 is inclined so as to be gradually displaced outward as it goes forward (see FIG. 2). A part of the outer frame part 2, for example, the left and right side parts located on the lower side are provided as bent parts 5 and 5, respectively, and the bent parts 5 and 5 are formed in a gently curved surface convex outward. .

  Engagement portions 6, 6, and 6 are provided on the outer surface of the bent portion 5 so as to protrude outward (see FIGS. 1 and 3). The engaging portion 6 protrudes from the outer peripheral surface of the bent portion 5, is formed in a shape extending in the front-rear direction, and is spaced apart in the circumferential direction of the outer frame portion 2. The engaging portion 6 protrudes in a direction inclined at a predetermined angle with respect to the thickness direction (H shown in FIG. 3) of the continuous portion 5 a continuous with the engaging portion 6 in the bent portion 5.

  The inclination angle θ with respect to the thickness direction H of the engaging portion 6 is, for example, about 10 °. As will be described later, the engaging portion 6 has a function of preventing deformation of the bent portions 5 and 5 due to the shrinkage of the molten resin. However, if the inclination angle θ is smaller than 5 °, the molten resin The deformation of the bent portions 5 and 5 due to the shrinkage of the resin cannot be prevented, and if the inclination angle θ is larger than 60 °, the flow of the molten resin becomes complicated and the quality of the resin molded product 1 cannot be improved. . Therefore, it is desirable that the inclination angle θ of the engaging portion 6 with respect to the thickness direction H is 5 ° or more and 60 ° or less.

  The shielding surface portion 3 faces substantially in the front-rear direction, and both upper and lower ends are continuous with each part of the inner periphery of the outer frame portion 2 (see FIGS. 1 and 2). The shielding surface portion 3 is positioned in the middle portion in the left-right direction inside the outer frame portion 2, and the left and right side portions of the shielding surface portion 3 in the resin molded product 1 are formed as transmission holes 1a and 1a, respectively. In a state where the resin molded product 1 is arranged inside the vehicle headlamp, lamp units (not shown) are arranged behind the transmission holes 1a and 1a, respectively, and light emitted from these lamp units is transmitted through the transmission hole 1a. 1a is transmitted and irradiated forward.

  As shown in FIGS. 1 and 2, the projecting portion 4 includes an outer peripheral surface portion 7 that protrudes forward from the inner peripheral edge of the shielding surface portion 3 and an inner peripheral surface portion 8 that is positioned inside the front end portion of the outer peripheral surface portion 7. The front edge of the outer peripheral surface portion 7 and the front edge of the inner peripheral surface portion 8 are connected by connecting portions 9, 9,. The connecting portions 9, 9,... Are spaced apart in the circumferential direction, and the protrusion 4 has slits 4a, 4a,... Extending in the circumferential direction between the connecting portions 9, 9,. Is formed.

  The outer peripheral surface portion 7 is inclined so as to be gradually displaced inward as going forward, and the inner peripheral surface portion 8 is inclined so as to be gradually displaced outward as going forward.

  A part of the outer peripheral portion at the rear end portion of the inner peripheral surface portion 8 is provided as an engaging portion 8a protruding rearward. At the position near the rear end on the outer peripheral surface of the inner peripheral surface portion 8, a floating prevention protrusion 10 that protrudes outward is provided. A space inside the inner peripheral surface portion 8 in the projecting portion 4 is formed as a transmission space 4b.

  In a state where the resin molded product 1 is arranged inside the vehicle headlamp, a lamp unit (not shown) is arranged behind the projecting portion 4, and the light emitted from the lamp unit is slits 4a, 4a,. -And it permeate | transmits the transmission space 4b and is irradiated ahead.

  The resin molded product 1 is formed as a design surface 1b in which the inner peripheral surface of the outer frame portion 2, the front surface of the shielding surface portion 3, and the outer surface of the protruding portion 4 are mirror surfaces, and the resin molded product 1 is the interior of the vehicle headlamp. The design surface 1b is a surface that can be visually recognized from the outside in the state of being disposed on the surface.

<Die structure>
Next, a mold 100 for molding the resin molded product 1 by injection molding will be described (see FIGS. 4 to 6).

  4 to 6 show the respective cross sections of the mold 100 together with the resin molded product 1, and the respective states of the resin molded product 1 are molded by the mold 100 at the respective cross-section indicating lines shown in FIG. FIG.

  The mold 100 has a first mold 101 used as a movable mold and a second mold 102 used as a fixed mold. The first mold 101 is a core mold used as a movable mold, for example, and the second mold 102 is a mold mold used as a fixed mold, for example. The first mold 101 and the second mold 102 are abutted to form a cavity 103 filled with molten resin. In the mold 100, the direction of separation when the first mold 101 and the second mold 102 are closed or opened is, for example, the front-rear direction.

  A part of the inner surface of the first mold 101, that is, the cavity forming surface 104 that forms the cavity 103, is formed as curved surfaces 104a and 104a, respectively (see FIG. 5). Further, the inner surface of the second mold 102, that is, the cavity forming surface 105 that forms the cavity 103, is partially formed as the curved surface portions 105 a and 105 a, and the curved surface portions 104 a and 104 a of the first mold 101 and the second surface are formed. The bent portions 5 and 5 are formed by the curved surface portions 105a and 105a of the mold 101, respectively.

  The first mold 101 has formation concave portions 104b, 104b,... Opened in the curved portions 104a, 104a (see FIGS. 4 and 5). The engaging portion 6 is formed by the forming recess 104b.

  The first mold 101 and the second mold 102 are provided with projecting portions 106 and 107 for forming the annular projecting portion 4 (see FIG. 6). An engagement recess 106a that opens forward is formed in the protrusion forming portion 106 of the first mold 101, and an engagement portion 8a is formed by the engagement recess 106a. Further, the protrusion forming portion 106 is formed with a concave portion 106b that is opened inward, and the concave portion 106b forms the floating prevention protrusion 10.

<Functions of each part>
Below, the function of the engaging parts 6, 6, ..., the engaging part 8a, and the floating prevention protrusion 10 is demonstrated.

  First, the function of the engaging portion 6 will be described.

  When the cavity 103 of the mold 100 is filled with the molten resin and cooled, a shrinkage force is generated in the molten resin at the time of cooling, and in the outer frame portion 2, the shrinkage force is particularly in the circumferential direction (see FIGS. 1 and 5). It is large in the A direction). When such a contraction force in the A direction is generated, a deformation force is generated in the bending portions 5 and 5 in a direction in which the curvature increases (the B direction shown in FIGS. 3 and 5) due to the contraction force. The B direction (deformation direction) coincides with the thickness direction H of the engaging portion 6.

  However, since the resin molded product 1 is provided with the engaging portions 6, 6,... Inclined at a predetermined angle θ with respect to the deformation direction B, the deformation of the bent portions 5, 5 caused by the contraction force is provided. Deformation in direction B is prevented.

  Therefore, in the resin molded product 1, deformation of the bent portions 5, 5 during cooling of the molten resin is prevented by the engaging portions 6, 6,. When the mold 102 is opened, the bent portions 5 and 5 are not deformed, and the bent portions 5 and 5 are prevented from being damaged due to contact with the second mold 102, so that the moldability of the resin molded product 1 can be improved. .

  Next, the function of the engaging portion 8a will be described.

  When the cavity 103 of the mold 100 is filled with the molten resin and cooled, a contraction force is generated in the melt resin during cooling, and the contraction force is particularly generated in the circumferential direction (see FIG. 1 in the C direction). When the contraction force in the C direction is generated, the curvature is generated in the portions 11, 11,... (See FIG. 1) between the connecting portions 9, 9,. Deformation force is generated in the direction in which the angle increases (D direction shown in FIG. 6).

  However, in the resin molded product 1, since the engaging portion 8a inclined by approximately 90 ° with respect to the deformation direction D is provided, the deformation of the inner peripheral surface portion 8 in the deformation direction D due to the contractile force is prevented. The

  Therefore, in the resin molded product 1, the engagement portion 8 a prevents the deformation of the inner peripheral surface portion 8 when the molten resin is cooled, so that the inner portion is opened when the first die 101 and the second die 102 are opened. The peripheral surface portion 8 is not deformed and the inner peripheral surface portion 8 is prevented from being damaged due to contact with the second mold 102, and the moldability of the resin molded product 1 can be improved.

  Next, the function of the floating prevention protrusion 10 will be described.

  When the cavity 103 of the mold 100 is filled with the molten resin and cooled, a shrinkage force is generated in the molten resin at the time of cooling, and the inner peripheral surface portion 8 of the protrusion 4 has a width direction ( A contracting force in the direction E shown in FIG. 6 is also generated. When such a contraction force in the E direction is generated, the contraction force is a force in a direction in which the engagement portion 8a is pulled out from the engagement recess 106a, that is, an engagement state of the engagement portion 8a with respect to the first mold 101. It becomes a force in the direction to be released.

  However, since the resin molded product 1 is provided with the anti-floating protrusion 10 that protrudes in a direction substantially orthogonal to the contraction direction E, the inner peripheral surface portion 8 is prevented from contracting in the E direction.

  Therefore, in the resin molded product 1, the float prevention protrusion 10 prevents the inner peripheral surface portion 8 from contracting in the E direction when the molten resin is cooled. The engagement state is not released, the above-described good function of the engagement portion 8a is exhibited, the inner peripheral surface portion 8 is prevented from being damaged by contact with the second mold 102, and the moldability of the resin molded product 1 is improved. Improvements can be made.

  The floating prevention projection 10 is undercut when the resin molded product 1 is ejected from the first mold 101 by an unillustrated eject pin, and the resin molded product 1 is forcibly removed from the first mold 101. Although it is removed from the first mold 101 by so-called forcible removal from the mold 101, the resin molded product 1 is scratched by forcibly removing because the anti-floating protrusion 10 is provided on the surface opposite to the design surface 1b. Even in the case of the occurrence of the problem, the good design of the resin molded product 1 is not hindered.

<Modification of mold>
Below, the metal mold | die 100A which concerns on a modification is demonstrated (refer FIG. 7).

  In the above, an example in which the engagement recess 106a for forming the engagement portion 8a is formed in the first mold 101 is shown. However, as the mold 100A, the first mold 101 is compared with the first mold 101. A protruding die 108 that can move in the direction of separating the 101 and the second die 102 may be provided, and an engaging recess 108 a for forming the engaging portion 8 a may be formed in the protruding die 108.

  Since the protruding mold 108 is movable with respect to the first mold 101, the protruding mold 108 is used as an eject pin that ejects the resin molded product 1 formed by cooling the molten resin from the first mold 101. It is possible.

  By forming the engaging recess 108a in the protruding die 108 and using the protruding die 108 as an eject pin in this way, a dedicated eject pin is not required, and the mold is obtained while ensuring good moldability of the resin molded product 1. The structure of 100A can be simplified.

<Others>
In the above example, the engaging portion 6 is provided on the bent portion 5, the engaging portion 8 a is provided on the inner peripheral surface portion 8, and the floating prevention protrusion 10 is provided on the inner peripheral surface portion 8. The joint portions 6 and 8a and the anti-floating protrusion 10 can be provided in each portion where deformation may occur due to contraction other than the bent portion 5 or the inner peripheral surface portion 8.

  Moreover, although the engaging parts 6 and 8a and the floating prevention protrusion 10 were all provided in the 1st type | mold 101 side above, the engaging parts 6 and 8a and the floating prevention protrusion 10 were shown. It may be provided on either the first mold 101 side or the second mold 102 side. When the engaging portions 6 and 8 a and the anti-floating projection 10 are provided on the second mold 102 side, the respective portions for forming the engaging portions 6 and 8 a and the anti-floating protrusion 10 on the second die 102 are provided. What is necessary is just to form a recessed part.

  However, by providing the engaging portions 6 and 8a and the anti-floating protrusion 10 on the first die 101 side, the engaging portions 6 and 8a are provided on the surface side opposite to the design surface 1b formed by the second die 102. Therefore, the moldability of the resin molded product 1 can be improved without impairing the good design of the resin molded product 1.

  Moreover, in the resin molded product 1, vapor deposition by aluminum etc. may be performed to each required part from a viewpoint, such as an improvement of design property.

  The shapes and structures of the respective parts shown in the best mode for carrying out the invention described above are merely examples of the embodiments performed in practicing the present invention. The range should not be interpreted in a limited way.

  DESCRIPTION OF SYMBOLS 1 ... Resin molded product (vehicle lamp components), 1b ... Design surface, 5 ... Bending part, 6 ... Engagement part, 10 ... Lifting prevention protrusion, 100 ... Mold, 101 ... 1st type | mold, 102 ... 1st 2 mold, 103 ... cavity, 106 a ... engaging recess, 106 b ... recess, 100 A ... mold, 108 ... protruding mold

Therefore, when shrinkage occurs during the cooling of the molten resin, a force in the direction in which the radius of curvature increases at the bent portion due to the shrinkage. At this time, in the state where the mold is not opened, the vehicle lamp component to be molded is not deformed by the force generated in the bent portion, but the first mold (core mold) and the second mold (cavity mold). ) When the mold is opened, the bending causes deformation of the bent portion in the direction of increasing the radius of curvature, and the second mold rubs against the vehicle lamp component when the mold is opened. There is a risk that the lamp parts will be damaged and formability will be reduced.

When the cavity 103 of the mold 100 is filled with the molten resin and cooled, a shrinkage force is generated in the molten resin at the time of cooling, and in the outer frame portion 2, the shrinkage force is particularly in the circumferential direction (see FIGS. 1 and 5). It is large in the A direction). When the contraction force in the A direction is generated, a deformation force is generated in the bending portions 5 and 5 in the direction in which the radius of curvature increases (the B direction shown in FIGS. 3 and 5) due to the contraction force. The B direction (deformation direction) coincides with the thickness direction H of the engaging portion 6.

When the cavity 103 of the mold 100 is filled with the molten resin and cooled, a contraction force is generated in the melt resin during cooling, and the contraction force is particularly generated in the circumferential direction (see FIG. 1 in the C direction). When the contraction force in the C direction is generated, the curvature is generated in the portions 11, 11,... (See FIG. 1) between the connecting portions 9, 9,. Deformation force is generated in the direction in which the radius increases (direction D shown in FIG. 6).

Claims (5)

A resin molded product having a bent portion in which a molten resin filled in a cavity of a mold having a first mold and a second mold is cooled and molded and bent in a predetermined direction,
An engagement portion that is engaged with at least one of the first mold or the second mold and protrudes from the bent portion when the molten resin is cooled is provided,
The resin molded product, wherein the engagement portion is inclined with respect to a deformation direction of deformation caused by contraction of the bent portion during cooling. A surface in contact with the second mold of the molten resin is formed as a design surface,
The resin-molded product according to claim 1, wherein the engaging portion is provided on a surface opposite to the design surface. A recess is formed in the first mold;
There is provided a floating prevention protrusion that is engaged with the recess during the cooling and protrudes in a direction different from the contact / separation direction when the first mold and the second mold are closed or opened. The resin molded product according to claim 1 or 2. The mold is provided with a protruding mold that is movable with respect to the first mold in the direction of separation when the first mold and the second mold are closed or opened.
The resin molded product according to claim 1, wherein the protruding portion is formed with an engaging recess in which the engaging portion is engaged. A vehicular lamp used as a part of a vehicular lamp having a bent portion that is formed by cooling a molten resin filled in a cavity of a mold having a first mold and a second mold and being bent in a predetermined direction. Parts,
An engagement portion that is engaged with at least one of the first mold or the second mold and protrudes from the bent portion when the molten resin is cooled is provided,
The vehicle lamp component according to claim 1, wherein the engaging portion is inclined with respect to a deformation direction of deformation caused by contraction of the bent portion during cooling.

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