JPH056096Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a resin molded product such as a front lens used in an automobile lamp.

[Prior art]

As shown in FIG. 9, the front lens, which is a conventional resin molded product, has a container shape in which a leg region 4 that is substantially perpendicular to the outer periphery of a wide design surface region 2 is formed, as shown in FIG. 10. It is molded using mold equipment such as The mold device mainly includes upper and lower molds 12,
14, between the molds 12 and 14,
A cavity C that matches the shape of the front lens 1 is formed, and a resin supply path 16 extends into this cavity C, and molten resin is supplied from this resin supply path 16 into the cavity C to be solidified and molded. There is. A small diameter gate 17 is formed at the entrance of the resin supply path 16 to the cavity C, and the molded product is cut at this gate position to form the front lens 1. Therefore, as shown in FIG. 9, gate marks 5 remain on the surface of the leg region 4 of the front lens 1. In addition, in order to make the parting line PL, which is the mold separation surface, less noticeable, a stepped portion 6 is formed in the leg region 4, and the parting line PL is formed at the position of this stepped portion 6. .

[Problem that the invention attempts to solve]

However, in the case of the front lens, which is a conventional resin molded product, considering the flow of resin within cavity C,
The molten resin injected from the gate 17 heads in various directions as shown by arrows a, b, and c in FIG. However, since the design surface region 2 is far from the gate 17 position and is thinner than the leg region 4, the flow of resin in the design surface region 2 is weaker than the flow of resin in the leg region 4. It is becoming difficult to flow. For this reason, molding defects such as underfilling, welds, and sink marks may occur in the design surface area 2 after molding, resulting in the problem that a high-quality front lens cannot be obtained.

The present invention was devised in view of the problems of the prior art, and its purpose is to provide a high-quality resin molded product for a vehicle lamp.

[Means to solve the problem]

In order to achieve the above object, in the resin molded product of the vehicle lamp according to the present invention, a leg region that is substantially perpendicular to the designed surface region is formed on the outer periphery of the wide designed surface region, and the designed surface of the leg region is A step part transitioning from a thick part to a thin part is formed at a position away from the area, and the resin in the vehicle lamp is molded so that the gate mark of the molding die and the parting line are located at this step part. In molded products,
First, the molding is performed so that the gate trace of the molding die and the parting line around the gate are offset from the step position toward the design surface area.

As a second method, a part of the thick part of the stepped part is cut out toward the design surface area, and the gate trace of the molding die and the parting line around the gate are located in the stepped part of this notched part. It was molded by

Further, as a third means, the stepped portion is formed in a shape close to the design surface area.

[Effect]

The gate position is close to a wide design surface area, and the flow of molten resin injected from the gate tends to flow into the design surface area, so the flow of molten resin in the design surface area becomes active.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

Figures 1 to 4 show an embodiment of the present invention. Figure 1 is a perspective view of a resin front lens for a headlamp, and Figure 2 is a mold for molding the front lens shown in Figure 1. FIG. 3 is a sectional view of the device, FIG. 3 is an enlarged perspective view of the main part of the mold device, and FIG. 4 is an explanatory diagram illustrating the flow of molten resin within the cavity.

In these figures, the front lens 20 is composed of a wide thin design surface region 22 and a leg region 24 extending substantially perpendicularly from the outer periphery thereof. The leg region 24 is thicker than the design surface region 22, but a stepped portion 25 is provided around the substantially center of the leg region 24 in the height direction, and the lower region of this stepped portion 25 is on the side of the lamp body. A thin-walled seal leg region 26 is engaged with a seal groove (not shown). Further, the thickness d of the thick portion 24a is made smaller toward the stepped portion 25 (d ₁ <d ₂ ), and the outer surface of the thick portion 24 a of the leg region 24 has an inward slope as shown in FIG. It is said to be a face. The position of the stepped portion 25 corresponds to a mold separation surface of a mold device, which will be described later, that is, a parting line PL. Furthermore, there is a parting line on the surface of the thick portion 24a of the leg region 24.
Part of PL PL ₁ is formed. The parting line PL ₁ exposed on the surface is formed in a trapezoidal shape that rises from the step portion 25 position toward the vicinity of the design surface area ₂₂ . Gate ruins 2
There are 8 left.

FIG. 2 shows a mold device for molding the front lens 20 shown in FIG. 1, and this mold device mainly includes an upper mold 32, a lower mold 34, and a resin supply device 38. It consists of

A front lens-shaped cavity C ₁ and a resin passage 36 communicating with the cavity C ₁ via a gate 36 a are formed on the abutting surfaces of the upper and lower molds 32 and 34 . And resin supply device (nozzle) 3
The molten resin is supplied from 8 to the resin passage 36, and is injected into the cavity C1 through the gate _36a . Then, the molds 32 and 34 are cooled, and the molten resin in the cavity _C1 is solidified and molded.
The reference numeral 34a is a nest that is assembled and integrated as a lower mold, the reference numeral 40 is a protrusion mechanism for the molded product, and the reference numeral 42 is a spool lock pin.

A part of the abutment surface 35 of the lower mold 34 is projected upward, and a gate 36 is formed on this projection 35a.
a is formed, and this gate 36a is in the design surface area 2.
It is located near 2. For this reason, the arrow in Figure 4
As shown in a ₁ , the flow of the molten resin injected from the gate 36a reaches the design surface area 22 of the front lens.
The flow of the resin in this design surface area 22 becomes sufficiently active, a sufficient amount of molten resin is supplied, and the pressure during molding is also sufficiently high. Of course, since the thick portion 24a is thick, the thickness of the thick portion 24a gradually becomes thinner toward the step portion 25, and the flow of resin b ₁ and c ₁ in this portion is active as in the conventional case. . For this reason, the front lens 20, which is a molded product, does not suffer from defects such as underfilling, welds, sink marks, etc., unlike conventional lenses, and is of high quality.

Further, the parting line PL ₁ appears on the surface of the thick portion 24a in the leg region of the front lens, and this parting line PL ₁
If you set it so that it is on the lower wall side of 0, this parting line will be visible when the lamp is assembled to the vehicle.
PL ₁ is not visible from the outside and does not spoil the appearance.

5 and 6 show other embodiments of the present invention. FIG. 5 is an enlarged perspective view of the main part of the front lens, and FIG. 6 is a mold for molding the front lens shown in FIG. 5. FIG. 3 is an enlarged perspective view of the main part of the lower mold of the device.

In the first embodiment described above, the parting line PL of the mold device is the front lens 2 which is the molded product.
The parting line PL 1 is formed so as to be located at the stepped portion 25 formed in the leg region 24 of 0, and only the parting line PL ₁ including the gate mark 28 is formed on the surface of the thick portion 24a. However, in the front lens 20A in this embodiment, the parting line
A stepped portion 25 connected to the stepped portion 25 is provided at the PL ₁ forming position.
It has a structure in which a is formed. In addition, code 29
is the remains of the gate. That is, the thick portion 2 of the stepped portion 25
A part of 4a is cut out, and a stepped part 2 is formed in this cutout.
5a. The rest is the same as the embodiment described above, and the explanation thereof will be omitted by giving the same reference numerals.

The mold structure for molding such a front lens 20A includes a lower mold 3 as shown in FIG.
A protruding portion 35 protruding from the abutting surface 35 of No. 4
b extends to the position of the seal leg region molding surface 34b. The rest is the same as the mold device in the embodiment described above, and the explanation thereof will be omitted by giving the same reference numerals.

7 and 8 show still another embodiment of the present invention, in which FIG. 7 is a perspective view of the front lens;
FIG. 8 is a perspective view of a main part of the lower mold of the mold apparatus for molding the front lens shown in FIG. 7.

In the front lens 20B of this embodiment, the leg region 2
A step portion 25 formed in the design surface area 22 is provided around the step portion 25 at a position close to the design surface area 22, and the parting line PL and the gate trace 29 are located at this step portion 25. Side edge 22
A has a shape that protrudes outward. The rest is the same as the embodiment described above, and the explanation thereof will be omitted by giving the same reference numerals.

[Effect of idea]

As is clear from the above explanation, according to the resin molded product of the vehicle lamp according to the present invention, the gate position is close to a wide design surface area, and the flow of molten resin injected from the gate flows into the design surface area. Since it is easy to use, the flow of the molten resin becomes active in the design surface area, resulting in a high-quality resin molded product without molding defects such as underfilling, welds, and sink marks.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a front lens according to an embodiment of the present invention, Fig. 2 is a sectional view of the mold device for molding the lens shown in Fig. 1, and Fig. 3 is a cross-sectional view of the lower mold of the mold device. FIG. 4 is an explanatory diagram illustrating the flow of resin in the front lens. FIG. 5 is an enlarged perspective view of the main portion of the front lens according to another embodiment. FIG. 6 is the same as FIG. 5. FIG. 7 is a perspective view of a front lens according to another embodiment, and FIG. 8 is an enlarged perspective view of the lower mold of the lens molding device shown in FIG. FIG. 9 is a partially cutaway perspective view of a conventional front lens, and FIG. 10 is a sectional view of a conventional mold apparatus for molding a front lens. 20, 20A, 20B... Front lens which is a resin molded product, 22... Design surface area, 24... Leg area, 24a... Thick part, 25, 25a... Step part, 28, 29... Gate trace. , 35...Mold butt surface, 35a, 35b...Protrusion, 36a...Gate, PL, PL ₁ ...Parting line.

Claims (1)

[Claims for Utility Model Registration] (1) A leg region that is substantially perpendicular to the design surface area is formed on the outer periphery of a wide design surface area, and a leg area that is away from the design surface area of the leg area is formed from a thick wall portion. In a resin molded product for a vehicle lamp, in which a stepped portion transitioning to the thin wall portion is formed, and the gate mark of the molding die and the parting line are located in the stepped portion, the gate of the molding die is formed. 1. A resin molded product for a vehicle lamp, characterized in that the parting line around the mark and the gate is formed at a position offset toward the design surface area from the step position. (2) A leg region that is substantially orthogonal to the design surface area is formed on the outer periphery of the wide design surface area, and a stepped portion that transitions from the thick part to the thin part is formed in the leg area at a position away from the design surface area. In a resin molded product for a vehicle lamp that is formed such that the gate mark of the molding die and the parting line are located at this stepped portion, a part of the thick portion of the stepped portion is on the design surface area side. 1. A resin molded product for a vehicle lamp, characterized in that the resin molded product is formed such that a gate mark of a molding die and a parting line around the gate are located in a stepped portion of the notch. (3) A leg region that is substantially perpendicular to the design surface area is formed on the outer periphery of the wide design surface area, and a stepped portion that transitions from the thick part to the thin part is formed in the leg area at a position away from the design surface area. In a resin molded product for a vehicle lamp that is formed such that the gate mark of the molding die and the parting line are located at the stepped portion, the stepped portion is formed at a position close to the design surface area. A resin molded product for vehicle lighting, which is characterized by: