JP7366657B2 - Vehicle lighting parts and their manufacturing method - Google Patents

Description

The present invention relates to a vehicle lamp part and a method for manufacturing the same, and more particularly to a vehicle lamp part by injection molding and a method for manufacturing the same.

Conventionally, in order to reduce the weight of vehicle lamp components, it has been proposed to manufacture vehicle lamp components as injection foam molded articles using a resin material containing a foaming agent (for example, see Patent Document 1). ).

Japanese Patent Application Publication No. 2011-194853

However, if the foaming rate of the resin, that is, the rate of increase in volume due to foaming is increased in order to reduce the weight, the rigidity of the molded product will decrease. In particular, there is a risk of damage occurring at the vehicle mounting portion where the entire weight of the lamp is applied.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle lamp component and a method for manufacturing the same, which can ensure the strength of the vehicle mounting portion while making it possible to reduce the weight of the component body. With the goal.

In order to achieve the above object, a vehicle lamp component according to a first aspect of the present invention is a vehicle lamp component comprising a foamable resin, wherein the vehicle lamp component includes at least a main body portion. and a vehicle attachment part for attaching the main body part to the vehicle body, and the foaming rate of the resin constituting the vehicle attachment part is lower than the foaming rate of the resin constituting the main body part. .

In the above aspect, the average radius of the foamable resin cells may be smaller than 50 μm in the vehicle mounting portion, and the average radius of the foamable resin cells may be larger than 50 μm in the main body portion.

Further, in the above aspect, the foaming rate of the foamable resin in the vehicle attachment portion may be lower than 5%.

Further, a method of manufacturing a vehicle lamp part according to another aspect of the present invention is a method of manufacturing a vehicle lamp part by injecting a foamable resin material into a molding space of a mold, the method comprising: (a) ) injecting the foamable resin material into a molding space corresponding to the main body of the vehicle lamp component; (b) molding the foamable resin material to a molding space corresponding to the vehicle mounting portion of the vehicle lamp component; and a step of injecting into a space, the foaming rate of the resin constituting the vehicle attachment part in the molded product being smaller than the foaming rate of the resin constituting the main body part.

In the above aspect, in step (a), the foamable resin material is filled up to the vicinity of the molding space corresponding to the vehicle mounting part, and in step (b), gas is injected into the molding space corresponding to the vehicle mounting part. You can do it like this.

In the above aspect, in step (a), the foamable resin material is injected from a main body side gate provided in a molding space corresponding to the main body of the mold; After filling the resin material beyond the attachment part side gate provided in the molding space corresponding to the vehicle attachment part of the mold, in step (b), the foamable resin material is injected from the attachment part side gate. You may also do so.

Further, in the above aspect, a plurality of gates are provided in a molding space corresponding to the main body portion of the mold, and in step (a), gates are provided in a region of the mold where the filling speed of the foamable resin material is slow. The timing of opening the gates may be controlled so that the gates provided in the mold are opened earlier, and the gates provided in the region of the mold where the filling speed of the foamable resin material is faster are opened later.

In addition, in this specification, the term "foaming rate" means the ratio of weight change per volume of a molded product between the unfoamed state and the foamed state, and is expressed by the following formula for the same volume. .
Foaming rate (%) = 100 x {(Weight of molded product when unfoamed) - (Weight of molded product when foamed)}/(Weight of molded product when unfoamed)
For example, if the weight of the unfoamed molded product is 100 g and the weight of the foamed molded product is 95 g, the foaming rate (%) is 100×{(100-95)}/100=5%.

According to the above aspect, it is possible to provide a vehicle lamp part and a method for manufacturing the same, which can reduce the weight of the main body part and ensure the strength of the vehicle mounting part.

FIG. 1 is a rear perspective view of a vehicle lamp component according to a first embodiment of the present invention. It is a graph showing the relationship between the foaming rate and the physical property maintenance rate of the foamable resin that is the material of the vehicle lamp part. FIG. 2 is a schematic cross-sectional view of an injection molding apparatus used for manufacturing the vehicle lamp part. It is a schematic diagram explaining the process of the manufacturing method of the same vehicle lamp part. FIG. 2 is a schematic cross-sectional view of an injection molding apparatus used in a method for manufacturing vehicle lamp parts according to a second embodiment of the present invention. It is a schematic diagram explaining the process of the same manufacturing method. FIG. 2 is a schematic diagram illustrating a method for manufacturing a vehicle lamp component according to a first implementation according to a comparative example. It is a figure explaining the manufacturing method of the vehicle lamp part based on the 3rd Embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. Furthermore, in each embodiment, members having the same function are given the same name, the same configurations are given the same reference numerals, and overlapping explanations are omitted as appropriate.

(First embodiment)
(Configuration of vehicle lighting parts)
FIG. 1 is a rear perspective view of a vehicle lamp component (hereinafter simply referred to as "lamp component") 10 according to an embodiment of the present invention. The lamp body component 10 is one in which the present invention is applied to a lamp body of a headlamp (lamp body). Inside the lamp component 10, other parts (not shown) constituting the lamp are arranged, such as a lamp unit including a light source, a reflector, and an extension. The lamp component 10 has a container-like shape with an open front, and a light chamber for the headlamp is defined by closing the front opening with a translucent front cover (not shown). .

The lamp component 10 has a main body portion 12 and a vehicle attachment portion 14. The main body portion 12 accommodates the other components that constitute the lamp body, as described above. The vehicle mounting portion 14 is a so-called bracket, and is a portion that is coupled to a mounting portion on the vehicle body side. In the illustrated lamp component 10 , the vehicle mounting portions 14 are provided at three locations on the peripheral edge of the main body portion 12 .

The lamp part 10 is made of foamable resin. As the main component of the foamable resin, it is preferable to use a polypropylene resin, but it is not limited thereto, and any known thermoplastic resin can be used. The foamable resin may also contain a certain amount (for example, 30%) of talc as an additive for imparting rigidity.

The foamable resin is, for example, a thermoplastic resin that is given foamability by encapsulating (press-fitting) a physical foaming agent. Alternatively, a thermoplastic resin may be added with foaming properties by mixing a chemical foaming agent.

As the physical foaming agent, any known physical foaming agent can be used, and it is preferable to use nitrogen, carbon dioxide, or the like. When nitrogen or carbon dioxide is used, for example, pellets of thermoplastic resin material are impregnated with nitrogen or carbon dioxide in a supercritical state in a pressure-resistant container to form a foamable resin material.

As the chemical blowing agent, any known chemical blowing agent can be used, and polystyrene is preferably used. When using a chemical foaming agent, the thermoplastic resin pellets and the chemical foaming agent are dry blended to form a foamable resin material.

Circles A and B in FIG. 1 schematically show cross-sectional structures of the resin in the main body portion 12 and the vehicle mounting portion 14, respectively. As shown in FIG. 1, the foaming rate is high in the main body portion 12, and the foaming rate is low in the vehicle mounting portion 14.

Generally, the higher the foaming rate of the resin, the higher the weight reduction effect, but the lower the retention rate of physical properties (strength, impact resistance, etc.). The vehicle mounting portion 14 supports the weight of the entire lamp, and is required to have strength because it is loaded by the impact when the vehicle collides with an obstacle. On the other hand, like other automobile parts, there is a strong demand for light body parts 10 to be lighter in order to improve fuel efficiency.

In this way, by making the foaming rate of the vehicle mounting portion 14 lower than that of the resin constituting the component body, it is possible to reduce the weight of the main body portion 12 while ensuring the strength of the vehicle mounting portion 14. Can be done.

Specifically, it is also preferable that the average radius d ₂ of the cells of the foamable resin in the vehicle mounting portion 14 is smaller than 50 μm, and that the average radius d ₁ of the cells in the main body portion 12 is larger than 50 μm.

In the actually manufactured lamp parts, the average radius of the bubbles in the foamable resin that maintained the physical properties (strength, impact resistance, etc.) required for the vehicle mounting portion 14 was 50 μm. The larger the average radius of the bubbles, the greater the weight reduction effect, but the retention rate of physical properties (strength, impact resistance) decreases. By making the average radius d ₂ of the bubbles 42 in the vehicle mounting portion 14 smaller than 50 μm and the average radius d ₁ of the bubbles in the main body 12 larger than 50 μm, the weight of the main body 12 can be reduced and the vehicle mounting can be easily achieved. The strength of the portion 14 can be ensured.

Alternatively, it is also preferable that the foaming rate of the foamable resin in the vehicle mounting portion 14 is lower than 5%.

FIG. 2 is a graph showing the relationship between foaming rate and physical property maintenance rate of a foamable resin molded product. Specifically, we used a polypropylene foamable resin molded product with 30% talc added, unfoamed (foaming rate 0%), and foamed molded products with foaming rates of 5%, 10%, and 15%. The product was subjected to a Charpy impact test, and the impact resistance retention ratio of the foamed molded product with each foaming ratio was plotted against the molded product with a foaming ratio of 0%.

From Figure 2, the retention rate of physical properties decreases linearly until the foaming rate reaches 5%, and at a foaming rate of 5%, the retention rate is approximately 40%, and when the expansion rate exceeds 5%, the retention rate of physical properties gradually decreases. However, it has remained almost flat. The physical property maintenance rate required for the vehicle attachment part 14 is about 40% or more, and the physical property maintenance rate for the main body part 12 only needs to be about 30%. Therefore, if the foaming rate of the foamable resin in the vehicle attachment part 14 is lower than 5%, the vehicle attachment part 14 can secure the necessary strength, and the main body part 12 can increase the foaming rate as necessary. Therefore, the weight of the main body portion 12 can be reduced.

(Method for manufacturing lamp parts)
Next, a method for manufacturing the lamp component 10 according to the present embodiment will be described. First, the injection molding apparatus 20 for manufacturing the lamp body part 10 will be described.

FIG. 3 is a schematic cross-sectional view showing a schematic configuration of the injection molding apparatus 20. As shown in FIG. For convenience of illustration, FIG. 3 does not reflect the exact shape of injection molding apparatus 20. Further, as shown in FIG. 1, the lamp component 10 has three vehicle attachment portions 14, but FIG. 3 shows an arbitrary one of them. The following description with reference to FIG. 3 is applicable to all vehicle mounting portions 14.

The injection molding apparatus 20 includes a mold 22 and a cylinder 24 for injecting a foamable resin material 40, which is a molding material, into the mold 22. The mold 22 includes a fixed mold 26 and a movable mold 28. Since the movable mold 28 is configured to be movable in the direction of the double arrow X, the mold 22 can be opened and closed. A cavity formed between the fixed mold 26 and the movable mold 28 of the mold 22 constitutes a molding space 32 corresponding to the lamp component 10.

Further, the molding space 32 includes a first portion 32 a corresponding to the main body portion 12 of the lamp component 10 and a second portion 32 b corresponding to the vehicle mounting portion 14 . A first portion 32a of the molding space 32 is provided with a gate 23 that is inserted into the cylinder 24. The cylinder 24 includes a hopper 34 for introducing a foamable resin material 40 as a molding material.

A gas inlet 36 and a gas outlet 38 are provided in a portion of the mold 22 corresponding to the second portion 32b. A cylinder (not shown) capable of supplying a gas G such as nitrogen or carbon dioxide is connected to the gas injection port 36, and the injection of the gas G can be controlled by a valve 37 that can be opened and closed. . Further, a valve 39 that can be opened and closed is also provided at the gas discharge port 38, so that the discharge of gas can be controlled.

Note that the actual lamp component 10 has a complicated shape as shown in FIG. For this reason, the mold may have a so-called undercut portion that cannot be opened (released). In this case, a core mold (not shown) separate from the fixed mold and movable mold is used to mold the undercut portion. Since such a method is well known, its explanation will be omitted.

Next, a method for manufacturing the lamp component 10 according to the first embodiment will be described with reference to FIG. 4.

In FIG. 4(a), a foamable resin material 40 is put into the cylinder 24 from the hopper 34, melted and stirred in the cylinder 24, and formed into a molding space 32 corresponding to the main body 12 of the lamp part 10 from the cylinder 24. Inject into the first portion 32a. Due to the high pressure inside the cylinder, the bubbles 42 caused by the foaming agent are small (or almost eliminated).

Next, in FIG. 4(b), the foamable resin material 40 is filled up to the vicinity of the second portion 32b of the molding space 32 corresponding to the vehicle mounting portion 14. At this time, since the pressure inside the mold 22 is lower than that inside the cylinder, the bubbles 42 gradually grow and become larger.

Next, in FIG. 4(c), after filling the foamable resin material 40 to the vicinity of the second portion 32b corresponding to the vehicle mounting portion 14, the valve 37 of the gas inlet 36 is opened and the second portion 32b is filled with the foamable resin material 40. Gas G is injected into the portion 32b. At this time, the foamable resin material 40 continues to flow toward the second portion 32b, but the pressure in the second portion 32b inside the mold is increased by the injection of gas G from the gas injection port 36. Rise. For this reason, the cells of the foamable resin material 40 contract, and foaming is suppressed.

Next, in FIG. 4(d), as the foamable resin material 40 is filled, the valve 37 of the gas inlet 36 is closed, the valve 39 of the gas outlet 38 is opened, and the inside of the mold 22 is Gas G is discharged, and filling of the second portion 32b of the foamable resin material 40 is completed. Note that the reason for discharging the gas in the mold 22 is to prevent the gas G from interfering with filling the second portion 32b with the foamable resin material 40.

Thereafter, the mold 22 is opened to obtain a molded product, which is the lamp component 10. In this manner, it is possible to obtain the lamp component 10 configured such that the foaming rate of the foamable resin is high in the main body portion 12 and the foaming rate is low in the vehicle mounting portion 14. Note that the foaming rate of the foamable resin in the main body part 12 and the vehicle mounting part 14 can be determined by, for example, providing an internal pressure sensor (not shown) inside the mold 22 and determining the pressure of the injected resin detected by the internal pressure sensor. It is controlled by adjusting the injection pressure of the foamable resin material 40 so that the desired foaming rate can be achieved. For example, when filling a foamable resin in which supercritical nitrogen gas is dissolved, if injection control is performed so that the filling pressure is 40 MPa or more, a foaming ratio of 5% or less can be achieved.

Further, as shown in FIG. 4(d), the portion with a low foaming rate does not necessarily include only the vehicle mounting portion 14, but also includes the vicinity of the vehicle mounting portion 14 in the main body portion 12, that is, the base of the vehicle mounting portion 14. Good too. That is, in this specification, the statement that "the foaming rate of the foamable resin is high in the main body part 12, and the foaming rate is low in the vehicle attachment part 14" refers to a comparison of the entire body, and This does not prevent the foaming rate from decreasing in the vicinity of the attachment portion 14.

(Second embodiment)
Next, a method for manufacturing a lamp body component according to a second embodiment will be described. FIG. 5 is a schematic cross-sectional view showing a schematic configuration of an injection molding apparatus 120 for manufacturing the same lamp component 10 as in the first embodiment.

As shown in FIG. 5, the injection molding apparatus 120 includes a mold 122 and a first cylinder 124 for injecting a foamable resin material 40, which is a molding material, into the mold 122 from a main body side gate 123.

The mold 122 includes a fixed mold 126 and a movable mold 28. Since the movable mold 28 is configured to be movable in the direction of the double arrow X, the mold 122 can be opened and closed. A cavity formed between the fixed mold 126 and the movable mold 28 of the mold 122 constitutes a molding space 32 corresponding to the lamp component 10.

In addition to the main body side gate 123, a mounting part side gate 43 is provided in a part of the fixed mold 126, which is close to the first part 32a of the second part 32b of the molding space 32, for injecting the molding material. A second cylinder 44 is provided. The first cylinder 124 and the second cylinder 44 each include a hopper 34 and a hopper 46 for introducing foamable resin material 40, which is a molding material, into the cylinders.

Next, a method for manufacturing the lamp component 10 according to the second embodiment will be described with reference to FIG. 6.

In FIG. 6(a), first, the foamable resin material 40 prepared in the same manner as in the first embodiment by being charged into the main body cylinder 124 from the hopper 34 and melted and stirred in the main body cylinder 124 is transferred to the main body side cylinder 124. The gate 123 is opened and the liquid is injected from the main body side cylinder 124 into the first portion 32a of the molding space 32 corresponding to the main body portion 12 of the lamp component 10. Due to the high pressure inside the cylinder, the bubbles 42 caused by the foaming agent are small (or almost eliminated).

Next, in FIG. 6(b), the foamable resin material 40 is filled up to the vicinity of the second portion 32b of the molding space 32 corresponding to the vehicle mounting portion 14. At this time, the pressure inside the mold 122 is lower than that inside the cylinder, so the bubbles 42 gradually grow and become larger.

Next, in FIG. 6(c), after filling the foamable resin material 40 from the main body side gate 123 until it exceeds the mounting part side gate 43, the mounting part side gate 43 is opened, and the mounting part side cylinder 44 is filled with the foamable resin material 40. The foamable resin material 40 is injected into the second portion 32b of the molding space 32 from the inside.

Next, in FIG. 6(d), filling of the second portion 32b is completed . In addition to the foamable resin material 40 flowing from the main body side gate 123, the foamable resin material 40 also flows into the second portion 32b from the attachment part side gate 43 , so that the pressure inside the foamable resin material 40 is reduced. The air bubbles shrink and foaming is suppressed, resulting in smaller (or almost no) air bubbles.

Thereafter, the mold 122 is opened to obtain a molded product, which is the lamp component 10. Even in this case, it is possible to obtain a lamp part 10 configured such that the foaming rate of the foamable resin is high in the main body part 12 and low in the vehicle mounting part 14, and the main body part 12 is lightweight. The strength of the vehicle mounting portion 14 can be ensured while making it possible to Note that the foaming rate of the foamable resin 40 in the main body part 12 and the vehicle mounting part 14 is determined by providing an internal pressure sensor (not shown) inside the mold 122, as in the method according to the first embodiment. The pressure of the injected resin detected by the internal pressure sensor is controlled by adjusting the injection pressure of the foamable resin 40 so that the pressure can achieve a desired foaming rate.

(Third embodiment)
Next, a method for manufacturing a lamp body component according to a third embodiment will be described. The manufacturing method according to the third embodiment is also a method for manufacturing the same lamp body component 10 as in the first embodiment. The method according to the third embodiment is a molding process of the first portion 32a of the molding space 32, which is related to the methods according to the first embodiment and the second embodiment, that is, FIG. 4(b), and a modification of the process corresponding to FIGS. 6(a) and 6(b).

As shown in FIG. 1, the lamp component 10 has a complicated shape. Further, the lamp body component 10 is a relatively large molded product. Therefore, the first portion 32a is a large molding space that occupies most of the lamp body component 10. As described above, in the manufacturing method of complicated and large-sized injection molded products, a multi-point gate method is used in which a plurality of gates are provided and resin is injected from the plurality of gates. However, when this multi-gate injection molding is applied to the main body of a lamp part that is a foamed resin molded product, there are problems such as those that occur in the following comparative example.

(Comparative example)
Here, as a comparative example of the method of manufacturing a lamp body component according to the third embodiment, a conventional molding process of the first portion 32a will be described with reference to FIG. FIGS. 7A to 7C are schematic diagrams showing how resin flows within the first portion 32a of the molding space 32 in an injection molding apparatus 920 of a comparative example. A portion of the injection molding device 920 corresponding to the first portion 32a has approximately the same configuration as the injection molding device 20 and the injection molding device 120 except for the number of gates and cylinders.

That is, the injection molding apparatus 920 includes three gates 23a, 23b, and 23c in a portion corresponding to the first portion 32a. Note that in FIG. 7, the shape of the first portion 32a is shown in a simplified manner for convenience of explanation. That is, the first portion 32a has a shape corresponding to the main body portion 12 in FIG. The first portion 32a is provided with filling ends 48a, 48b, 48c corresponding to the three gates 23a, 23b, 23c, respectively.

However, since the actual lamp part 10 has a complicated shape as shown in FIG. Due to differences, etc., non-uniformity may occur in filling speed and foaming rate.

Specifically, in FIG. 7(a), the foamable resin material 40 injected under the same conditions from the first gate 23a, the second gate 23b, and the third gate 23c is applied to the first region 32a1 and the third gate 23c. The filling speed may be fast in the second region 32a2, and the flow speed may be slow in the third region 32a3.

In this case, as shown in FIG. 7(b), the filling ends 48a and 48b are filled quickly, but the filling end 48c is delayed.

In injection molding, a holding pressure is generally applied to completely fill the mold with molten resin to the filling end, and to prevent the resin from flowing back through the gate. In order to completely fill the filling end 48c, the pressure from the third gate 23c is higher than the holding pressure at the first and second gates 23a and 23b, as shown in FIG. It is necessary to apply a holding pressure P.

Then, the internal pressure also increases in the first region 32a1 and the second region 32a2 that communicate with the third region 32a3, and the air bubbles 42 contract in the first region 32a1 and the second region 32a2, causing the expansion of the foamable resin. A problem arises in that foaming is inhibited. As a result, there is a possibility that the desired effect of reducing the weight of the main body portion 12 may not be obtained.

(Example)
Next, a process for forming the first portion 32a according to the third embodiment will be described with reference to FIG. 8. FIGS. 8(a) to 8(c) are schematic diagrams showing how resin flows within the first portion 32a of the molding space 32 in the injection molding apparatus 220 of this embodiment. A portion of the injection molding device 220 corresponding to the first portion 32a has approximately the same configuration as the injection molding device 920 of the comparative example.

That is, the injection molding apparatus 220 includes three gates 223a, 223b, and 223c in a portion corresponding to the first portion 32a. Note that in FIG. 8 as well, the shape of the first portion 32a is illustrated in a simplified manner for convenience of explanation, as in FIG. 7. However, the injection molding apparatus 220 is different from the injection molding apparatus 920 in that the three gates 223a, 223b, and 223c of the injection molding apparatus 220 are controlled so that the opening and closing timings thereof can be staggered.

Specifically, when resin filling is started, first, in FIG. 8A, the third gate 223c is opened and the foamable resin material 40 is injected into the third region 32a3.

Next, in FIG. 8(b), the first and second gates 223a and 223b are opened, and injection of the foamable resin material 40 into the first region 32a1 and the second region 32a2 is started. In the first and second regions 32a1 and 32a2, the filling speed of the foamable resin material 40 is fast, and in the third region 32a3, the filling speed is slow.

Then, in FIG. 8(c), the foamable resin material 40 simultaneously reaches the filling ends 48a, 48b, 48c in respective regions. In this case, there is no region where filling is delayed, so there is no need to apply high holding pressure. As a result, the internal pressure within the mold does not increase excessively, and the foaming of the foamable resin material 40 is not inhibited. Therefore, the foamable resin material 40 can be appropriately foamed, and sufficient weight reduction can be achieved.

As described above, according to the method for manufacturing a lamp body component according to the present embodiment, the first and second regions 32a1 and 32a2 provided in the first and second regions 32a1 and 32a2, which increase the filling speed of the foamable resin material 40, The timing of opening the gates is controlled by shifting so that the second gates 223a and 223b are opened earlier and the third gate provided in the third region 32a3 where the filling speed is slower is opened later.

As a result, the foamable resin material 40 is simultaneously filled in all regions up to the filling end. Therefore, it is not necessary to apply high holding pressure to some areas where filling is delayed, and the holding pressure can be reduced as a whole. As a result, it is possible to prevent the internal pressure from increasing in each region, so that the foaming of the foamable resin material 40 is not inhibited, and the weight of the main body portion 12 can be reduced.

Further, the gate 23 (23a, 23b, 23c) is positioned at a position away from the second portion 32b, for example, at the lower front of the lamp part 10 that is farthest from the two vehicle attachment parts 14 in FIG. If it is set in this region, the flow distance of the foamable resin material 40 becomes longer, the foaming rate in the main body part 12 can be adjusted, and the weight can be easily reduced.

By combining the manufacturing method of lamp parts according to the present embodiment with the manufacturing method according to the first or second embodiment, the foaming rate of the foamable resin is high in the main body part 12, and the foaming rate of the foamable resin is high in the main body part 12. Now, in the lamp component 10 configured to have a low foaming rate, the effect of reducing the weight of the main body 12 can be further enhanced.

As described above, as an embodiment of the present invention, an example has been given in which the present invention is applied to a lamp body of a vehicle headlamp. Needless to say, it can be applied. Furthermore, the present invention is not limited to the embodiments, and various modifications or modifications based on the present disclosure are included within the scope of the present invention.

10 Vehicle lighting parts (lighting parts)
12 Main body part 14 Vehicle mounting part 22 Mold 32 Molding space 32a First part (molding space corresponding to the main body part)
32b Second part (molding space corresponding to vehicle mounting part)
23 Gate 123 Main body side gate 43 Mounting part side gate 23a First gate 23b Second gate 23c Third gate

Claims (7)

A vehicle lamp part comprising a foamable resin,
The vehicle lamp component has at least a main body portion and a vehicle mounting portion for attaching the main body portion to the vehicle body,
The foaming rate of the resin constituting the vehicle attachment part is lower than the foaming rate of the resin constituting the main body part,
A vehicle lamp component , wherein the foaming rate of the foamable resin in the vehicle mounting portion is lower than 5% . According to claim 1, wherein in the vehicle attachment portion, the average radius of the foamable resin cells is smaller than 50 μm, and in the main body portion, the average radius of the foamable resin cells is larger than 50 μm. vehicle lighting parts. 3. The vehicle lamp component according to claim 1, wherein the vehicle mounting portion is a small piece member provided so as to protrude from a peripheral edge of the main body portion. A method for manufacturing vehicle lamp parts by injecting a foamable resin material into a molding space of a mold, the method comprising:
(a) injecting the foamable resin material into a molding space corresponding to the main body of the vehicle lamp component;
(b) injecting the foamable resin material into a molding space corresponding to a vehicle mounting portion of a vehicle lamp component;
The foaming rate of the resin constituting the vehicle attachment part in the molded product is lower than the foaming rate of the resin constituting the main body part,
A method for manufacturing a vehicle lamp component , wherein the foaming rate of the foamable resin in the vehicle mounting portion is lower than 5% . In step (a), a foamable resin material is filled up to the vicinity of the molding space corresponding to the vehicle attachment part,
5. The method for manufacturing a vehicle lamp component according to claim 4, wherein in step (b), gas is injected into a molding space corresponding to the vehicle mounting portion. In step (a), the foamable resin material is injected from a main body side gate provided in a molding space corresponding to the main body part of the mold,
In step (a), after filling the foamable resin material beyond the attachment part side gate provided in the molding space corresponding to the vehicle attachment part of the mold,
5. The method of manufacturing a vehicle lamp component according to claim 4, wherein in step (b), the foamable resin material is injected from the mounting portion side gate. A plurality of gates are provided in a molding space corresponding to the main body of the mold,
In step (a),
quickly opening a gate provided in a region of the mold where the filling speed of the foamable resin material is slow;
7. A method for a vehicle according to claim 4, wherein the gate opening timing is controlled so that a gate provided in a region of the mold where the filling speed of the foamable resin material is faster is opened later. Method of manufacturing light body parts.