JP2015147343A - Injection molding die, resin molding, and optical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adherence defect of a molding to a fixed side die upon mold opening, and facilitate release of the molding from a movable side die after the mold opening, when a molding having such a structure as to easily cause an adherence defect is molded by an injection molding method.SOLUTION: An injection molding die includes: a movable side die member 50 which has a movable side molding surface 61a forming a cavity 100 between itself and a fixed side molding surface 15a of a fixed side die member 10, and approaches to and separates from the fixed side die member; and an ejector pin 75 appearing and disappearing from an insertion hole 90. On the movable side molding surface, a fine uneven region 110 for holding the molding on the movable side molding surface is provided, when the movable side die member is separated from the fixed side die member after a molten resin has been cooled and solidified, and the fine uneven region is arranged locally on an outer peripheral edge of the insertion hole 90.

Description

  The present invention molds a resin optical element used in various optical devices, particularly a plastic optical element having a fine uneven shape on the surface (incident surface or outgoing surface, or both surfaces thereof) to prevent a trail phenomenon. The present invention relates to an injection mold for molding, a molded resin molded product, or an optical element, and an optical system and an optical apparatus having the same.

Conventionally, various optical devices such as in-vehicle view cameras, backlight light guide plates, projectors, scanners, etc. have specific optical characteristics, durability and weather resistance (durability characteristics) according to the purpose of use and environment of each device. An optical element having the following is required.
A transparent optical element such as a lens has a large refractive index and thus has a high reflectance. On the other hand, ghosts and flares are caused due to the large reflectance and optical characteristics such as image quality deterioration. May be adversely affected. For this reason, it is necessary to impart an antireflection function to an optical element made of a transparent material.
As a technique for imparting an antireflection function, multilayer coating by a vapor deposition method or a sputtering method is known. However, the multilayer coating has various problems such as poor heat resistance, high production cost, and large wavelength dependency.
For this reason, in recent years, it has been proposed to form a fine structure having a wavelength of visible light or less by an injection molding method and to use it for antireflection.

By the way, it has been performed in various fields to form fine irregularities on the surface of a plastic element (molded product) using injection molding or the like, and to obtain a function of plus α by the fine irregularities. Specific examples of plastic molded products that give fine irregularities include, for example, optical lenses used in digital cameras and optical pickup lenses and optical pickup lenses in order to achieve various objectives such as miniaturization and weight reduction and improvement of aberration characteristics. The Fresnel lens used can be mentioned. In addition to optical applications, micro-channels used in the bio field, water-repellent sheets that use the Lotus effect, etc. can be used to make fine irregularities on the surface of plastic molded articles using injection molding, etc. There is an example of adding the function of α.
However, the following problems arise when a molded product having fine irregularities on its surface is manufactured by an injection molding method.

FIG. 14 and FIG. 15 are explanatory diagrams of molded products each having fine irregularities on the transfer surface.
The molded product 200 in FIG. 14 has a fixed-side fine unevenness transfer surface 201a on a fixed-side transfer surface 201 that has been transferred from a molding surface of a fixed-side mold member (not shown). The movable transfer surface 202 that has received the transfer from the molding surface of the movable mold member (not shown) is a smooth surface 202a.
The molded product 200 of FIG. 15 has a fixed side fine unevenness transfer surface 201a and a movable side fine unevenness transfer surface 202b on both the fixed side transfer surface 201 and the movable side transfer surface 202. In this case, if the contact area between the molded product transfer surfaces 201 and 202 and the mold is “fixed side contact area> movable side contact area”, the adhesion between each molded product transfer surface and the mold is “fixed side contact area”. Since “mold> movable mold”, there is a problem that when the mold is opened, a molded product is raised from the parting surface.

That is, the trail phenomenon is a phenomenon in which the molded product is taken up by the fixed molding surface when the mold is opened, and is lifted from the movable molding surface, and the molded product is ejected from the movable molding surface by the ejector pin for removal. Previously, the molded product moves with respect to the movable molding surface and causes a problem that the molded product is separated from the movable molding surface.
Even in a molded product in which both the fixed-side transfer surface and the movable-side transfer surface are smooth surfaces, the contact phenomenon between the molded product transfer surface and the mold molding surface is “fixed-side contact area> In the case of “movable side contact area”, the contact force between the molded product transfer surface and the mold forming surface may be generated by “fixed side mold> movable side mold”.
As a measure for preventing this trail phenomenon, a method is known in which a molded product is not left in a fixed mold by a Z pin or a cross pin provided in a sprue portion. In addition, the molding surface with many irregularities is intentionally designed on the movable mold side so that the adhesion between the molded product transfer surface and the mold molding surface is "fixed mold <movable mold". Thus, a method for preventing the trailer to the fixed mold is known.

However, in the former case, since the tip shape of the Z pin or the cross pin is transferred to the molded product, it cannot be used for the product portion. For this reason, when the release property of the cavity corresponding to the product part is poor, only the sprue part is released from the mold, and the molded product may remain in the cavity.
In the latter case, due to restrictions in terms of product performance and functions, the adhesion between the molded product transfer surface and the mold molding surface cannot be designed to be "fixed side mold <movable side mold". There were many. Furthermore, excessive adhesion of the molded product to the movable side mold causes the molded product to be released from the mold by the ejector operation (demolding failure), which causes the molded product to have poor appearance and the automatic take-out machine. There were problems such as.
As a solution to such mold release defects, a coating-type mold release agent may be used to reduce the adhesion between the molded product transfer surface and the fixed mold molding surface. There has been a problem that the released release agent is transferred and adhered to the molded product, resulting in poor appearance, or the release agent needs to be reapplied periodically in order to maintain releasability.

Patent Document 1 discloses a method of releasing air by injecting air into a molded product after the mold is opened, and Patent Document 2 discloses a method of releasing the entire nesting of a movable side mold that is a molding transfer surface. It is disclosed.
However, in the case of Patent Document 1, there is a problem that the molded product is warped when the flow rate of the jet air is uneven, or the internal quality (for example, birefringence) of the molded product is deteriorated due to local cooling of the air injection unit. There are challenges. In the case of Patent Document 2, there is a problem that the mold structure becomes complicated.

Patent Document 3 proposes a method for preventing a trail by applying a water-repellent surface treatment to the surface of a fixed mold and improving the releasability from the fixed mold.
However, it is difficult to perform a water-repellent surface treatment on the mold molding surface that forms the functional surface (for example, optical surface) of the molded product. In the case of a molded product with poor moldability, the release effect due to the water-repellent surface treatment cannot be exhibited.

An object of the present invention is to provide a molded product having a structure that is easy to generate a trail, particularly when a molded product having fine irregularities on the surface is molded by an injection molding method. It is an object of the present invention to provide an injection mold for preventing the mold and releasing the molded product from the movable mold after the mold is opened.
Moreover, it aims at suppressing the characteristic defect of the molded product by a tray or a mold release defect.

  In order to achieve the above object, an injection mold according to the present invention is an injection mold used in an injection molding method for obtaining a molded product by cooling and solidifying a molten resin filled in an internal cavity. A fixed-side mold member having a fixed-side molding surface and a movable-side molding surface that forms the cavity between the fixed-side molding surface and approaching and separating from the fixed-side mold member A movable mold member to be moved, and a movable mold member to be moved forward and backward in an insertion hole formed through the movable mold member so that one end is open to the movable mold surface, and the tip portion protrudes and retracts from the movable mold surface An ejector pin, and when the movable mold member is separated from the fixed mold member after the molten resin is cooled and solidified, the molded product is moved to the movable mold surface. Fine irregularities for holding The provided, the fine irregular region, characterized by being arranged on the outer periphery of the insertion hole.

According to the present invention, the presence of the fine uneven region in a part of the cavity prevents the so-called “trailer” in which the molded product (product part) remains on the fixed side molding surface of the fixed side mold when the mold is opened. It becomes possible.
In addition, since the tip surface of the ejector pin is positioned in the immediate vicinity of the fine unevenness region, the portion having the strongest adhesive force can be directly pressed by the ejector pin and released. For this reason, the fine uneven | corrugated area | region where the adhesive force with a product part becomes high can be removed effectively.

It is a longitudinal cross-sectional view which shows the internal structure of the principal part of the injection mold which concerns on the 1st Embodiment of this invention, (a) shows the time of a mold closing, (b) has shown the time of mold opening. . (A) is a longitudinal cross-sectional view of the principal part including the molded product in a cavity, (b) is an expanded sectional view of the principal part of the molded product. (A) (b) And (c) is an expanded sectional view which shows the structural example of a fine uneven | corrugated shaped part. It is a longitudinal cross-sectional view which shows the structure of the injection mold concerning the 2nd Embodiment of this invention, (a) shows the time of mold closing, (b) has shown the time of mold opening. It is a perspective view which shows the structure of embodiment of an ejector sleeve. It is a perspective view which shows the structural example of other embodiment of an ejector sleeve. FIG. 7 is a perspective view when an ejector pin is inserted into the ejector sleeve of FIG. 6, where (a) shows the ejector pin retracted and (b) shows the advancement. It is sectional drawing which shows the movement path | route of the hot air in an ejector sleeve. It is a longitudinal cross-sectional view which shows the structure of the ejector sleeve which concerns on the 4th Embodiment of this invention. (A) And (b) is sectional drawing which shows the optical component as a plastic molded product (resin molded product) manufactured by the injection molding die concerning each embodiment, and an important section expanded sectional view. It is a principal part expanded sectional view which shows the attachment affection of a plastic molded product. It is explanatory drawing of the image projection system using the projector apparatus as an example of the optical apparatus using the plastic molding (optical element) manufactured using the injection mold of this invention. It is a figure explaining an example of a structure of the image projection part of a projector apparatus. It is explanatory drawing of the molded article provided with the fine unevenness | corrugation in the transfer surface. It is explanatory drawing of the molded article provided with the fine unevenness | corrugation in the transfer surface.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 is a longitudinal sectional view showing an internal structure of a main part of an injection mold according to a first embodiment of the present invention, where (a) shows when the mold is closed and (b) shows when the mold is opened. Show. FIG. 2A is a longitudinal sectional view of the main part including the molded product in the cavity, and FIG. 2B is an enlarged cross-sectional view of the main part of the molded product. FIGS. 3A, 3B, and 3C are enlarged cross-sectional views showing examples of the configuration of the fine concavo-convex shape portion.
The injection mold 1 of the present invention is used in an injection molding method for obtaining a molded product by cooling and solidifying a molten resin filled in a cavity 100 inside a mold.

The schematic configuration of the injection mold 1 is as follows.
That is, the injection mold 1 includes a fixed mold member 10 having a fixed molding surface 15a on the inner surface and a movable molding surface 61a that forms a cavity between the fixed molding surface and is fixed. The movable mold member 50 that approaches and separates from the side mold member 10 and the insertion hole 90 that penetrates the movable mold member 50 so that one end of the movable mold surface 61a is open can be moved forward and backward. And an ejector pin 75 that is disposed and protrudes and retracts from the movable molding surface. The movable side molding surface 61a has a fine uneven region for holding the molded product 105 on the movable side molding surface when the movable side mold member 50 is separated from the fixed side mold member 10 after the molten resin is cooled and solidified. 110, and the fine uneven region is locally disposed on the outer peripheral edge of the insertion hole (arranged in the vicinity of the tip surface of the ejector pin).
The fixed-side mold member 10 is generally composed of a fixed-side mounting plate 11, a fixed-side mold plate 13, and a fixed-side insert 15.

The movable mold member 50 is generally composed of a movable mold plate 51, a back plate 53, a spacer block 55, an ejector plate 57, a movable attachment plate 59, and a movable insert 61.
Further, a locating ring 20, a sprue bush 22, and a guide pin bush 24 are disposed on the fixed mold member 10.
The movable mold member 50 includes a protruding rod 70, a return spring 72, an ejector pin 75, a sprue lock pin 80, a return pin 82, and a guide pin 85.

The fixed-side mounting plate 11 and the fixed-side template 13 are fixed and integrated, and a fixed-side insert 15 is housed and fixed in a recess 13 a provided on the inner surface of the fixed-side template 13. A cavity 100 is formed between the molding surface 15 a of the fixed side insert 15 and the molding surface 61 a of the movable side insert 61.
A guide pin bush 24 that slidably receives a guide pin 85 provided on the movable mold member is fixedly disposed in a through hole provided in another part of the fixed mold 13. By moving the guide pin 85 forward and backward in the guide pin bush 24, the movable mold member 50 can advance and retract in the front-rear direction along a stable linear track with respect to the fixed mold member 10. Here, the front direction is a direction toward the fixed mold, and the rear direction is a direction away from the fixed mold.

The sprue bushing 22 is disposed in a hole that penetrates the center portion of the fixed-side mounting plate 11 and the fixed-side mold plate to form the sprue 30. The sprue 30 communicates with the cavity 100 via the runner 31 and the gate 32 (FIG. 2A). The molten resin supplied from the sprue is filled in the cavity. Reference numeral 33 denotes a sprue lock pin transfer portion.
In addition, since the insert is used in this example, the inner surface of each insert is provided with a molding surface. However, this is only an example, and the present invention is also applied to a type in which the inner surface of each mold member is provided with a molding surface. Is applicable. That is, in the illustrated embodiment, the movable-side molding surface 61 a is formed in the movable-side insert 61 disposed in the movable-side mold member, and at least a part of the insertion hole 90 is formed through the insert 61. But this is just an example. It is sufficient that the movable-side molding surface 61a is formed on a part of the movable-side mold member.

The movable side mold plate 51, the back plate 53, the spacer block 55, and the movable side mounting plate 59 are integrated.
A movable side insert 61 is housed and fixed in a recess 51 b provided on the inner side surface of the movable side template 51. A cavity 100 is formed between the molding surface 61 a of the fixed side insert 61 and the molding surface 15 a of the fixed side insert 15.

The ejector plate 57 is disposed in a space formed between the back plate 53 and the movable side mounting plate 59 and is configured to be able to advance and retract in the front-rear direction. The ejector plate 57 is driven forward and backward by a protruding rod 70 supported so as to be movable forward and backward in a guide hole 59a formed through the movable side mounting plate 59.
Each ejector pin 75 has a rear portion fixed by an ejector plate 57, and other portions including the front end portion are inserted through holes 90 formed in a straight line extending over the back plate 53, the movable side mold plate 51, and the movable side nest 61. It is slidably inserted (movable forward and backward). Each ejector pin 75 is moved forward and backward by the longitudinal movement of the ejector plate 57. In the forward movement, the tip of the ejector pin 75 protrudes into the cavity 100 from the molding surface 61 a of the movable side insert 61. In the reverse operation, the ejector pin 75 protruding into the cavity from the molding surface 61a of the movable side insert 61 is pulled back to the movable side mold member 50 side.
The guide pin 85 has a rear portion fixed in a support hole 51a formed in the movable side mold plate 51. When the mold is closed in FIG. 1A, the guide pin 85 is placed in the guide pin bush 24 arranged on the fixed side mold plate 13. The front part is detached from the guide pin bush 24 when the mold shown in FIG.

The return pin 82 has a rear portion fixed to the ejector plate 57 and a front portion slidably disposed in a guide hole 92 formed so as to penetrate the back plate 53 and the movable side mold plate 51. Since the ejector plate 57 is in the retracted position when the mold shown in FIG. 1A is closed, the tip of the return pin 82 is in contact with the movable mold (the inner surface of the fixed mold 13).
The return spring 72 wound around the outer periphery of the return pin 82 acts so as to push the ejector plate 57 back backward by the force of expansion.

Since the ejector plate 57 moves forward when the mold shown in FIG. 1B is opened, the tip of the return pin 82 protrudes from the inner surface of the movable side mold plate 51.
The fixed-side mold member 10 and the movable-side mold member 50 are paired. When the movable-side mold member 50 is closed as shown in FIG. A cavity 100 is formed between the mold member 50 (along the parting line PL), and a plastic molded product (resin molded product) 105 is molded by injection filling the cavity 100 with molten resin. After the resin is sufficiently cooled inside the cavity 100, the movable mold member 50 is opened (when the mold is opened in FIG. 1B), so that the plastic molded product 105 is released from the fixed mold member 10. The movable mold member 50 remains.
Finally, when the ejector pin 75 moves forward and its tip protrudes from the movable mold member 50 (the molding surface 61a of the movable insert 61) toward the cavity 100, the plastic molded product 105 is moved to the movable mold member. The plastic molded product is released from the movable mold member 50 by being pushed in the direction of releasing from 50.

In the present invention, on the surface surrounding the ejector pin end surface 75a of the molding surface 61a of the movable side insert 61 supported by the movable side mold member 50 (locally on the movable side molding surface corresponding to the outer periphery of the insertion hole). A fine uneven region 110 is arranged. Since the fine uneven region 110 constitutes a part of the movable side molding surface 61 a of the cavity 100, it is located at a corresponding position on the movable side transfer surface 105 a of the plastic molded product 105 molded using the main molding die 1. As shown in FIG. 2B, the fine unevenness transfer surface 105b of FIG. The fine unevenness transfer surface 105b of this example is annularly developed on the outer periphery of the ejector pin transfer surface 105c.
In this example, the fine uneven region 110 is formed on the molding surface of the movable side insert 61. However, when the insert is not used, it is arranged on the inner surface (molding surface) of the movable side mold member.

The fine uneven region 110 increases the contact area between the movable mold member 50 (movable side nest 61) and the plastic molded product 105 and improves the adhesion between them, so that the plastic molded product 105 is opened when the mold is opened. It functions to prevent so-called “trailing” remaining on the fixed-side mold member 10. In addition, since the ejector pin end surface 75a is in the vicinity of the inner surface of the fine concavo-convex region 110, the fine concavo-convex transfer surface 105b, which has a strong adhesion, can be directly released when the plastic molded product is ejected by the ejector pin. Become.
As a result, it becomes possible to prevent a mold release failure without causing a warp due to a mold release resistance caused by the adhesion between the plastic molded product 105 and the fine uneven region 110.

The cross-sectional shape of the fine concavo-convex region 110 in FIG. 3A is a continuum of a sharp angled convex shape and a concave shape, and the cross-sectional shape of the fine concavo-convex region 110 in FIG. The cross-sectional shape of the fine concavo-convex region 110 in FIG. 3C is an arcuate concave continuum.
The configuration examples shown in FIG. 3 are merely examples, and may be, for example, a shape obtained by combining the shapes shown in FIGS. 3A, 3B, and 3C, or other shapes.
There are many possible shapes for the fine uneven region 110, but in consideration of the durability of the mold and the adhesion to a plastic molded product, the maximum uneven height max in FIGS. 3 (a), 3 (b) and 3 (c). Is 50 μm or less, and the average height of the irregularities ave. And the uneven average width ave. The aspect ratio is preferably 0.5-2.

In addition, as a method for producing the fine uneven region 110, there are WPC processing, etching processing, laser processing, surface embossing by sandblasting, etc., but any production method may be used.
According to the present embodiment, since the fine uneven region 110 exists in a part of the cavity, a so-called “trailer” in which a molded product (product part) remains on the fixed side molding surface 15a of the fixed side mold when the mold is opened. It becomes possible to prevent.
In other words, in the case of molding a molded product having a structure that is likely to generate a trail, particularly a molded product having fine irregularities on the surface by an injection molding method, the trail of the molded product to the fixed side mold when the mold is opened is prevented. It is possible to easily release the molded product from the movable mold after the mold is opened, and it is possible to suppress a defective characteristic of the molded product due to a tray or a defective mold release.

In addition, since the tip surface 75a of the ejector pin 75 is located inside the fine uneven region 110, the portion having strong adhesive force can be directly pressed and released, and the product portion and the fine uneven region are in close contact with each other. It is possible to prevent mold release defects without causing warpage due to mold release resistance caused by force. As a result, it becomes possible to prevent the appearance defect of the molded product due to a tray or a mold release failure.
Further, by preventing the warpage of the molded product, it becomes possible to suppress the deterioration of the surface shape of the molded product and the internal distortion.

Furthermore, if a tray or mold release failure occurs during continuous molding, it is necessary to stop the molding machine operation and remove the molded product remaining in the mold, and the next molding can be performed with the molded product remaining. If it starts, it can damage the mold surface that forms the function of the product, and repairs are costly and time consuming.
On the other hand, according to the present invention, it is possible to maintain stable mass production and reduce maintenance costs such as maintenance by preventing a tray or mold release failure.

[Embodiment 2]
4A and 4B are longitudinal sectional views showing the configuration of an injection mold according to the second embodiment of the present invention. FIG. 4A shows a state when the mold is closed, and FIG. 4B shows a state when the mold is opened. FIG. 5 is a perspective view showing the configuration of the embodiment of the ejector sleeve.
In addition, the same code | symbol is attached | subjected to FIG. 1 and an identical part, and description of the overlapping structure is abbreviate | omitted.

The injection mold 1 according to the embodiment of FIG. 5 has fine uneven regions 110 provided in the movable mold member 50 in the movable mold member, specifically, the back plate 53 and the movable mold plate 51. The structure provided in the front end surface 120a of the ejector sleeve 120 fixedly disposed in the insertion hole 90 formed linearly through the movable side insert 61 is different from that of the first embodiment. In this example, the ejector sleeve 120 is disposed in the insertion hole 90 located in the movable side template 51 and the movable side insert 61.
Since the front end surface 120a of the ejector sleeve 120 is exposed in the cavity 100, the fine uneven region 110 can be transferred to the molded product.

In the first embodiment, the insertion hole 90 in which the ejector sleeve 120 is disposed is sufficient if the inner diameter is such that the ejector pin 75 can be slidably advanced and retracted. However, the insertion hole 90 of the present embodiment is not limited to the ejector pin. The ejector sleeve 120, which is a cylindrical body having a larger diameter than the diameter, is made large enough to be disposed. The ejector sleeve 120 includes a long small diameter portion 121 and a short large diameter portion 122 fixed to one end of the long small diameter portion, and a shaft hole (an axial through hole) that supports the ejector pin 75 so as to be able to advance and retract. ) 123 is formed. A part of the insertion hole 90 is stepped so that the insertion hole 90 can be supported in close contact with the outer surface of the ejector sleeve 120 having such an outer shape.
The fine concavo-convex region 110 is formed on the annular tip surface 120 a of the ejector sleeve 120, and the ejector pin protrudes from the shaft hole 123 into the cavity 100.

The configuration of the present embodiment is effective when it is difficult to restrict the fine uneven region 110 to the movable side insert 61 in a limited manner.
For example, when the distance between the functional surface on the molded product side that is not allowed to form an uneven shape and the fine uneven region 110 is short, or when the material of the movable side nest 61 is difficult to form fine unevenness, the movable side By forming the fine uneven region 110 on the tip surface 120a of the ejector sleeve 120 instead of the molding surface 61a of the insert 61, there is an advantage that the processing of the fine uneven region and the mirror surface processing on the movable side insert 61 are facilitated.

  Further, since the mirror processing of the movable side insert 61 and the processing of the fine uneven region 110 on the tip surface of the ejector plate can be performed separately, the mirror surface processing is performed on the movable side insert, and then the fine unevenness is formed on the tip surface of the ejector sleeve. When the region is processed and formed, work steps such as masking can be shortened, and as a result, there is an advantage that the processing cost is reduced.

[Embodiment 3]
FIG. 6 is a perspective view showing a configuration example of another embodiment of the ejector sleeve, FIG. 7 is a perspective view when the ejector pin 75 is inserted into the ejector sleeve of FIG. 6, and (a) is a backward movement of the ejector pin. (B) shows the forward time. FIG. 8 is a cross-sectional view showing a moving path of hot air in the ejector sleeve.
The ejector sleeve 120 according to the present embodiment is different from the second embodiment in that an air injection port 124 communicating with the shaft hole 123 is formed on the side surface of the long small diameter portion 121 of the ejector sleeve.

The air inlet 124 is an opening for flowing hot air into the shaft hole 123. With the ejector sleeve 120 positioned in the insertion hole 90, the air inlet 124 is supplied with hot air via an air introduction path (not shown) formed in the movable side mold 51.
The shaft hole 123 has the maximum inner diameter in the inside 123a of the short large diameter portion 122, the inside 123b of the long small diameter portion 121 corresponding to the air inlet 124 has a medium diameter, and further, the inside 123c of the tip portion. Has a small diameter.
The ejector pin 75 inserted into the shaft hole 123 moves back and forth between the retracted position in FIG. 7A and the advanced position in FIG.

As shown in FIGS. 7A and 7B, an O-ring 130 is disposed in the shaft hole portion of the inside 123 a of the short large diameter portion 122. The O-ring 130 is injected from the air injection port 124 by being in close contact with the inner wall of the short large-diameter portion 122 at its outer peripheral surface and slidably (air-tightly) supporting the outer peripheral surface of the ejector pin 75 by the center hole. Block the flow of hot air behind.
As shown in FIG. 7, there is a minute gap 125 for ventilation extending in the axial direction between the ejector pin 75 and the inner wall of the shaft hole 123 of the ejector sleeve, and the width of the minute gap 125 is 0.02 mm or less. is there.

The hot air introduced from the air inlet 124 is jetted into the ejector sleeve 120, moves forward through the inside of the ejector sleeve 120 (inside 123 b of the small diameter portion 121), and finally moves through the minute gap 125. It discharges | emits to the line L side, and the fine uneven | corrugated area | region 110 is heated with a hot air simultaneously.
The gas used as hot air is, for example, air, carbon dioxide, nitrogen or the like.

In actual molding, hot air is previously poured into the ejector sleeve 120 from the air inlet 124 with the movable mold member closed with respect to the fixed mold member 10 as shown in FIG. The fine uneven region 110 is heated to a certain temperature, and then the molten resin is injected and filled into the cavity 100.
Prior to the filling of the molten resin, the fine uneven region 110 is heated to a predetermined temperature by hot air, so that the fluidity of the molten resin does not deteriorate and the fine uneven region 110 is likely to enter. For this reason, the contact area between the plastic molded product 105 and the movable mold member 50 is increased, the adhesion between the plastic molded product 105 and the movable mold member 50 is increased, and the transferability is improved.

As a result, it is possible to further enhance the effect of preventing the plastic molded product 105 from being moved to the stationary mold member 10.
In addition, it is preferable that the surface temperature of the fine uneven | corrugated area | region 110 at the time of a heating is more than the glass transition temperature of resin to be used.
In addition, since only the surface of the fine uneven area is heated by hot air, the influence on the molding tact is small, and there is only a mechanism for injecting air, so the mold structure is not complicated and the cartridge heater No complicated wiring is required.

[Embodiment 4]
FIG. 9 is a longitudinal sectional view showing a configuration of an ejector sleeve according to the fourth embodiment of the present invention.
The ejector sleeve 120 according to the present embodiment is characterized in that a roughened region 127 made of fine irregularities is formed in the interior 123c of the tip.
In the ejector sleeve of the third embodiment, by blowing hot air from the air inlet 124, the ejector sleeve 120 and the ejector pin 75 are thermally expanded, the width of the minute gap 125 is reduced, and the ejector pin 75 moves forward and backward. Sliding resistance (frictional force) increases. For this reason, a problem such as galling may occur between the ejector pin 75 and the inner wall of the ejector sleeve 120.

On the other hand, in this embodiment, by providing the rough machining region 127 in the inside 123c of the tip end portion of the shaft hole 123 of the ejector sleeve 120, the contact area between the ejector sleeve 120 and the ejector pin 75 when thermally expanded is increased. The frictional resistance between the ejector sleeve 120 and the ejector pin 75 can be reduced. As a result, it becomes possible to prevent galling.
The rough processing region 127 can be easily formed by performing WPC processing or etching processing.
Further, when the uneven shape of the fine uneven region 110 and the rough processed region may be functionally the same shape, the fine uneven region and the rough processed region are manufactured by processing in the same process as the fine uneven region 110. Shortening of period and cost reduction can be expected.

[Embodiment 5]
10 (a) and 10 (b) are a cross-sectional view and an enlarged cross-sectional view showing a main part of an optical component as a plastic molded product (resin molded product) manufactured by the injection mold according to each of the above embodiments. . FIG. 11 is an enlarged cross-sectional view of a main part showing an attached state of the plastic molded product.
10 includes a fixed-side optical functional surface 106 formed by receiving the transfer of the fixed-side molding surface 15a of the fixed-side mold member 10, and a movable-side molding surface 61a of the movable-side mold member 50. A movable-side optical functional surface 107 formed by receiving the transfer, an adhesive surface 108 positioned annularly on the outer peripheral edge side of each functional surface, an annular attachment reference surface 109 positioned on the outer peripheral edge side of the adhesive surface, It has roughly.
FIG. 10B is an enlarged view of the vicinity of the adhesive surface of FIG. 10A, and the adhesive surface 108 includes a fine unevenness transfer region 108a and an ejector pin transfer region 108b. The fine unevenness transfer region 108a is a portion to which the fine unevenness region 110 in the first or second embodiment is transferred, and the ejector pin transfer region 108b is a portion to which the tip surface of the ejector sleep 120 is transferred.

  In the first embodiment, an annular fine uneven region 110 is formed on the movable side molding surface 61 a, and the fine uneven region is transferred to a portion corresponding to the adhesive surface 108 of the plastic molded product 105. An uneven transfer region 108a is formed. In the second embodiment, the fine uneven region 110 is formed on the annular tip surface of the ejector sleep 120, and the fine uneven region is transferred to a portion corresponding to the adhesive surface 108 of the plastic molded product 105, so An uneven transfer region 108a is formed.

FIG. 11 is an enlarged cross-sectional view showing a state in which an optical element (lens) as a plastic molded product is attached to an optical device.
In this example, the UV curable resin 142 and other adhesives are used when the bonding surface 108 of the plastic molded product 105 is bonded to the attachment site 140 of the optical device.
When the UV curable resin 142 or the like is applied between the adhesive surface 108 of the plastic molded product 105 and the attachment site 140, and the UV curable resin 142 is cured by UV irradiation to adhere the plastic molded product 105 to the attachment site 142. In addition, when the adhesive surface 108 is in the vicinity of the attachment reference surface 109, the UV curable resin 142 may enter between the attachment reference surface 109 and the attachment portion 140, and the reference may be shifted.

In addition, when the adhesive surface 108 exists in the vicinity of the movable optical functional surface 107, the UV curable resin 142 adheres to the movable optical functional surface 107 and has a serious adverse effect on the product function (for example, image defect or insufficient light quantity). , Ghost, flare).
On the other hand, in the plastic molded product 105 according to the present embodiment, there is a fine unevenness transfer region 108 a on the bonding surface 108. For this reason, when the adhesive surface 108 of the plastic molded product 105 and the attachment portion 140 are bonded using an adhesive such as a UV curable resin 142, the fine uneven transfer region 108a works as a hydrophilic surface, so that the adhesive is Protruding from the bonding surface 108 can be prevented. Therefore, the above-mentioned various problems caused by the adhesive entering and attaching to the attachment reference surface 109 and the movable optical function surface 107 can be solved.
As described above, since the optical element can be positioned with high accuracy when the optical element is bonded to the mounting portion of the optical device, and the adhesive is not attached to the movable optical function surface, the in-vehicle view camera, It is possible to maintain high performance of various optical devices such as a backlight light guide plate, a projector, and a scanner.

[Optical apparatus using the optical element of the present invention]
FIG. 12 is an explanatory diagram of an image projection system using a projector device as an example of an optical apparatus using a plastic molded product (optical element) manufactured using the injection mold of the present invention, and FIG. It is a figure explaining an example of a structure of the image projection part of an apparatus.
The image projection system 150 includes a projector device 151 that can project an image onto a screen (projection surface) S, a PC terminal 152 that can input image data for projection to the projector device 151, and a multi-function printer (MFP). ) 153.
The projector device 151, the PC terminal 152, and the multifunction device 153 are communicably connected via a network NW.
Further, the image projection system 150 captures the projection surface S, and acquires dirt detection image data for detecting the position of a region on the projection surface S that affects the visibility of the projection image, such as dirt or a pattern. A digital camera (imaging means) 154 is provided.

The projector device 1 performs an image process optimal for image projection on the projection image data input from the external device, and then projects a projection image based on the projection image data onto the projection plane S.
The liquid crystal projector device 151 shown in FIG. 13 includes, as an image projection unit, a first lens array 162 arranged to face an emission surface of a lamp L as a light source, and a superimposing lens 164 arranged on the emission side. It is equipped with.
The light emitted from the superimposing lens 164 is reflected by the reflection mirror 165 and is incident on the color light separation optical system 179 including the dichroic mirrors 170 and 171 and the reflection mirror 178.

The image projection unit further includes an incident side lens 180, a relay lens 181, reflection mirrors 182, 183, three field lenses 184, 185, 186, three liquid crystal panels 187R, 187G, 187B, and a cross dichroic. And a prism 188.
The reflection mirror 165 has a function of reflecting the light emitted from the superimposing lens 164 in the direction of the color light separation optical system 179. The color light separation optical system 179 has a function of separating light emitted from the superimposing lens 164 into three color lights of red, green, and blue by the two dichroic mirrors 171 and 170.

The first dichroic mirror 171 transmits the red light component of the light emitted from the superimposing lens 164 and reflects the blue light component and the green light component. The red light transmitted through the first dichroic mirror 171 is reflected by the reflection mirror 178, passes through the field lens 186, and reaches the liquid crystal panel 187R for red light. The field lens 186 converts each partial light beam emitted from the superimposing lens 164 into a light beam parallel to the central axis (principal light beam). The same applies to the field lenses 184 and 185 provided in front of other liquid crystal panels.
Of the blue light and green light reflected by the first dichroic mirror 171, the green light is reflected by the second dichroic mirror 170, passes through the field lens 185, and reaches the liquid crystal panel 187G for green light. On the other hand, the blue light passes through the second dichroic mirror 170, passes through the light guide optical system, that is, the incident side lens 180, is reflected by the reflection mirror 182, passes through the relay lens 181, and is reflected by the reflection mirror 183. To do.

Further, the blue light passes through the field lens 184 and reaches the liquid crystal panel 187B for blue light.
The three liquid crystal panels 187R, 187G, and 187B have a function as light modulation means for modulating incident light according to image information (image signal) given from the controller.
As a result, each color light incident on the three liquid crystal panels 187R, 187G, and 187B is modulated according to the given image information to form an image of each color light. The three colors of modulated light emitted from the three liquid crystal panels 187R, 187G, and 187B are incident on the cross dichroic prism 188.

The cross dichroic prism 188 combines the three colors of modulated light to form a color image. In the cross dichroic prism 188, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a substantially X shape at the interface of four right-angle prisms. These dielectric multilayer films combine three colors of modulated light to form combined light for projecting a color image. The combined light generated by the cross dichroic prism 188 is emitted in the direction of the projection lens 156.
The projector device is merely an example of an optical device, and the optical element of the present invention can be applied to a vehicle-mounted view camera, a backlight light guide plate, a scanner, and other various optical devices.

[Summary of Configuration, Action, and Effect of the Present Invention]
The injection mold according to the first aspect of the present invention is an injection mold 1 used in an injection molding method for obtaining a molded product 105 by cooling and solidifying a molten resin filled in an internal cavity 100. The fixed-side mold member 10 having the fixed-side molding surface 15a and the movable-side molding surface 61a that forms a cavity between the fixed-side molding surface and approaching and separating from the fixed-side mold member. A movable mold member 50 and an ejector that is movably disposed in an insertion hole 90 that is formed through the movable mold member so that one end of the movable mold surface is open, and causes the tip portion to protrude and retract from the movable mold surface. And a pin 75 for holding the molded product on the movable-side molding surface when the movable-side mold member is separated from the fixed-side mold member after the molten resin is cooled and solidified. Provided with a fine uneven region 110, fine uneven Pass a (locally) the outer peripheral edge of the insertion hole, characterized in that disposed.
According to this, the presence of the fine uneven region 110 in a part of the cavity prevents the so-called “trailer” in which the molded product (product part) remains on the fixed molding surface 15a of the fixed mold when the mold is opened. It becomes possible to do.

In addition, since the tip end surface 75a of the ejector pin 75 is positioned in the immediate vicinity of the minute uneven region 110, the portion having the strongest adhesion can be directly pressed and released from the ejector pin. For this reason, the fine uneven | corrugated area | region where the adhesive force with a product part becomes high can be removed effectively. Therefore, it is possible to prevent a mold release failure without causing a warp due to a mold release resistance due to a high adhesion force with the product portion. As a result, it becomes possible to prevent the appearance defect of the molded product due to the tray or the mold release failure.
Further, by preventing the warpage of the molded product, it is possible to suppress the deterioration of the surface shape and appearance of the molded product and the internal distortion.

In addition, if there is a trace or mold release failure during continuous molding, the operation of the molding machine must be stopped and the molded product remaining in the mold must be removed. In such a case, the surface of the mold that forms the function of the product may be damaged, and the repair requires enormous costs and time.
On the other hand, according to the present invention, it is possible to maintain stable mass production and reduce maintenance costs such as maintenance by preventing a tray or mold release failure.

In the injection mold according to the second aspect of the present invention, the movable-side molding surface 61a is formed in the movable-side insert 61 disposed in the movable-side mold member, and at least a part of the insertion hole 90 is the insert 61. It is characterized by being formed through.
The present invention can also be applied to an injection mold having a nest. That is, the movable-side molding surface may be provided directly on the movable-side mold member, or may be provided on a movable-side insert (which constitutes a part of the movable-side mold member) incorporated in the movable-side mold member. good.

In the injection mold according to the third aspect of the present invention, the ejector pin 75 is inserted into the shaft hole 123 of the ejector sleeve 120 disposed in the insertion hole 90, and the tip end surface 120a of the ejector sleeve is moved to the movable side. A part of the molding surface 61a is formed, and the fine uneven region 110 is disposed on at least a part of the tip surface of the ejector sleeve.
According to this, the fine concavo-convex region 110 was formed not on the movable mold member (or the movable nesting) but on the surface (tip surface 120a) constituting the cavity of the ejector sleeve. For this reason, when it is difficult to form a fine uneven region limitedly in the nest, for example, when the functional surface where the formation of the fine uneven region is not allowed and the distance between the surface on which the fine uneven region is formed are short, When the material is difficult to give fine unevenness, there is an advantage that the processing of the fine unevenness region becomes easy.
In addition, since the mirror surface processing for the nesting and the processing of the fine uneven area on the tip surface of the ejector sleeve can be performed separately, the work process such as masking can be shortened when performing the fine uneven area processing after the mirror surface processing. There is an advantage that the processing cost is low.

The injection mold according to the fourth aspect of the present invention is characterized in that hot air is supplied to the fine uneven region 110 on the front end surface of the ejector sleeve via the gap 125 between the ejector pin 75 and the ejector sleeve 120. .
According to this, hot air is poured into the ejector sleeve in advance to heat the minute uneven area to a certain temperature, and then the cavity 100 is injected and filled with molten resin, thereby heating the fine uneven area in advance. For this reason, it becomes easy for molten resin to enter the fine uneven region 110, the contact area between the product part and the movable side mold (movable side molding surface) increases, and the adhesion between the product part and the movable side mold increases, Transferability of the movable mold member to the product part is improved. As a result, it is possible to further enhance the effect of preventing the trail to the movable mold of the product part.
In addition, since only the surface of the fine uneven region is to be heated by hot air, the influence on the molding tact is small, and a mechanism for injecting air is sufficient. Therefore, the mold structure is not complicated, and complicated wiring such as a cartridge heater is not necessary.

The injection mold according to the fifth aspect of the present invention is characterized in that a roughing region 127 is provided on the inner surface of the ejector sleeve in contact with the ejector pin.
When hot air is blown into the minute gap between the shaft hole inner surface of the ejector sleeve and the outer surface of the ejector pin, the ejector sleeve and ejector pin thermally expand, the width of the minute gap becomes smaller, and the ejector pin slides when moving forward and backward. Resistance (frictional force) increases, and a malfunction such as galling may occur between the ejector pin and the ejector sleeve.
According to the present invention, by providing the rough machining region 127 on the inner diameter minimum surface of the ejector sleeve, the contact area between the ejector sleeve and the ejector pin can be reduced, and the friction generated between the ejector sleeve and the ejector pin. The force can be reduced. As a result, it is possible to prevent galling that occurs between the ejector pin and the ejector sleeve.
In addition, by reducing the contact area between the ejector sleeve and the ejector pin, it is possible to prevent adhesion between the metals, and it is possible to operate smoothly even when the ejector pin suddenly protrudes. As a result, the ejector pin can be prevented from being bent, bent, or damaged due to an excessive load applied to the ejector pin.

The resin molded product according to the sixth aspect of the present invention is a resin molded product molded using the injection mold, and the fine unevenness transfer region transferred to the resin molded product is a hydrophilic surface. It is characterized by.
When an adhesive 142 such as a UV curable resin is applied to adhere the adhesive surface 108 of the molded product (product part) 105 to another member, for example, an attachment site of an optical device, the adhesive surface is attached to the molded product. If it exists in the vicinity of the reference surface 109, the adhesive may enter between the attachment reference surface and the attachment part of the molded product, and the attachment reference may be shifted.

According to the present invention, by using the fine uneven region 110 as a hydrophilic surface, it is possible to prevent the adhesive from protruding when the molded product and the attachment site are bonded, and as a result, positioning is performed with high accuracy. It becomes possible.
Further, when the adhesive surface is present in the vicinity of the movable optical functional surface 107 of the molded product, the adhesive adheres to the movable optical functional surface, and has a serious adverse effect on the product function (for example, image defect or insufficient light quantity, (Ghost, flare, poor appearance). According to the present invention, by using the fine uneven region 110 as a hydrophilic surface, it is possible to prevent the adhesive from protruding when the molded product is bonded to other components, and as a result, high-quality plastic molding It becomes possible to provide goods.

In the optical apparatus according to the seventh aspect of the present invention, the resin molded product is an optical element, and the optical element is provided.
When this optical element is bonded to the mounting site of an optical device, positioning with high accuracy becomes possible, and adhesive is not attached to the movable optical function surface. The performance of various optical devices such as an optical plate, a projector, and a scanner can be maintained high.

DESCRIPTION OF SYMBOLS 1 ... Injection mold, 10 ... Fixed side mold member, 11 ... Fixed side mounting plate, 13 ... Fixed side mold plate, 13a ... Recess, 15a ... Fixed side molding surface, 15a ... Molding surface, 20 ... Locate Ring, 22 ... sprue bush, 24 ... guide pin bush, 30 ... sprue, 31 ... runner, 32 ... gate, 50 ... movable side mold member, 51 ... movable side mold plate, 51a ... support hole, 51b ... recess, 53 ... back plate, 55 ... spacer block, 57 ... ejector plate, 59 ... movable side mounting plate, 59a ... guide hole, 61 ... movable side insert, 61a ... movable side molding surface (molding surface), 70 ... rod, 72 ... Return spring, 75 ... ejector pin, 75a ... ejector pin end face (tip face), 80 ... sprue lock pin, 82 ... return pin, 85 ... guide pin, 90 ... insertion hole, 92 ... guide hole, 100 ... , 105 ... plastic molded product, 105 a ... movable side transfer surface, 105 b ... fine uneven transfer surface, 105 c ... ejector pin transfer surface, 106 ... fixed side optical functional surface, 107 ... movable side optical functional surface, 108 ... adhesion Surface 108a ... fine unevenness transfer area 108b ... ejector pin transfer area 109 109 reference surface 109 ... mounting reference surface 110 ... fine unevenness area 120 ... ejector sleeve 120a ... tip face 121 121 long small diameter part, 122 ... Short large diameter part, 123 ... Shaft hole, 123a ... Inside (inner wall), 123b ... Inside (inner wall), 123c ... Inside (inner wall), 124 ... Air inlet, 125 ... Micro gap, 127 ... Rough processing region, 130 ... O-ring, 140 ... part, 142 ... UV curable resin, 142 ... adhesive, 142 ... attachment part, 200 ... molded article, 201 ... fixed side roll Surface, 201,202 ... moldings transfer surface 201a ... fixed side fine unevenness transfer surface, 202 ... movable transfer surface, 202a ... smooth surface, 202b ... movable-side fine unevenness transfer surface.

JP2000-235742A JP2007-253459 JP2009-160795

Claims (7)

An injection mold used in an injection molding method for obtaining a molded product by cooling and solidifying a molten resin filled in an internal cavity,
A movable side having a fixed mold member having a fixed mold surface and a movable mold surface forming the cavity between the fixed mold surface and moving toward and away from the fixed mold member A mold member, an ejector pin that is disposed so as to freely advance and retreat in an insertion hole formed through the movable side mold member so that one end of the movable side molding surface opens, and a tip portion protrudes and retracts from the movable side molding surface; With
The movable side molding surface has a fine structure for holding the molded product on the movable side molding surface when the movable side mold member is separated from the fixed side mold member after the molten resin is cooled and solidified. With uneven areas,
An injection mold, wherein the fine uneven region is arranged on an outer peripheral edge of the insertion hole.   2. The movable side molding surface is formed in a nest disposed in the movable side mold member, and at least a part of the insertion hole is formed to penetrate the nest. Mold for injection molding. The ejector pin is inserted into the shaft hole of the ejector sleeve disposed in the insertion hole,
The tip surface of the ejector sleeve forms part of the movable side molding surface,
The injection mold according to claim 1 or 2, wherein the fine uneven region is disposed on at least a part of a front end surface of the ejector sleeve.   The injection mold according to claim 3, wherein hot air is supplied to the fine uneven region via a gap between the ejector pin and the ejector sleeve.   The injection mold according to claim 3 or 4, wherein a rough processing region is provided on an inner surface of the ejector sleeve that is in contact with the ejector pin.   A resin molded product molded using the injection mold according to any one of claims 1 to 5, wherein the fine unevenness transfer region transferred to the resin molded product is a hydrophilic surface. A resin molded product characterized by The resin molded product according to claim 6 is an optical element,
An optical apparatus comprising the optical element.

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