CN109571916B

CN109571916B - Molding device

Info

Publication number: CN109571916B
Application number: CN201811442599.9A
Authority: CN
Inventors: 周佩吟
Original assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Current assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Priority date: 2018-11-29
Filing date: 2018-11-29
Publication date: 2021-01-29
Anticipated expiration: 2038-11-29
Also published as: TW202019662A; CN109571916A; TWI706851B

Abstract

The present invention provides a molding apparatus comprising: the bearing part is provided with a groove, and the groove is provided with a bottom wall and a side wall connected with the bottom wall; the forming part is arranged on the bottom wall and is spaced from the side wall, the forming part is provided with a top surface far away from the bottom wall, and the top surface is used for bearing a product to be formed; the contour of the opening of the groove is the same as the contour of the edge of the top surface. According to the forming device provided by the invention, the outline of the opening of the groove of the forming part is set to be the same as the outline of the edge of the top surface of the forming part, so that the problem that the optical characteristics and the like of a film material are influenced due to stress on the film material in a thermoplastic forming process is favorably solved.

Description

Molding device

Technical Field

The invention relates to the field of tool fixtures, in particular to a forming device.

Background

At present, no matter VR (Virtual Reality) equipment, AR (Augmented Reality) equipment, wearable computers and the like generally need to be attached with optical films, and the optical films are generally finished by hot-press molding. Taking the process of forming an optical film by hot pressing molding as an example, especially when forming a curved optical film, in the hot pressing molding process, a film material needs to be placed on a hot pressing molding jig, the jig includes a molding area, and the contour of the molding area is the same as the contour of a target product. And applying pressure to the film material from the side of the film material far away from the jig, so that the film material finally forms a target product.

In the existing jig, when pressure is applied to the film material from a side of the film material away from the jig, the stress of the film material corresponding to the edge of the molding area is strong, so that the film material is stretched to generate deformation, and changes in optical characteristics and material thickness of the film material are further derived from the deformation, such as poor optical performance, uneven thickness of the film material, and the like.

Disclosure of Invention

The present invention provides a molding apparatus comprising:

the bearing part is provided with a groove, and the groove is provided with a bottom wall and a side wall connected with the bottom wall; and

the forming part is arranged on the bottom wall and is spaced from the side wall, the forming part is provided with a top surface far away from the bottom wall, and the top surface is used for bearing a product to be formed;

the contour of the opening of the groove is the same as the contour of the edge of the top surface.

According to the forming device provided by the embodiment of the invention, the outline of the opening of the groove of the bearing part is set to be the same as the outline of the edge of the top surface of the forming part, so that the edge stress of a film material is relatively small when pressure is applied to the film material in a thermoplastic forming process, and the problem that the optical property and the like of the film material are influenced due to the stress on the film material in the thermoplastic forming process is favorably solved.

Drawings

Fig. 1 is a schematic perspective view of a molding apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic sectional view along the direction ii-ii in fig. 1.

Fig. 3 is a projected pattern of the recess opening and the top surface of the molding.

Fig. 4 is a schematic sectional view showing a state of use of the molding apparatus.

Fig. 5 is another schematic sectional view of the molding apparatus in use.

Description of the main elements

Molding device	10
		Bearing part	11
Forming section	12
		Groove	111
Bottom wall	112
		Side wall	113
Opening of the container	114
		Top surface	121
Depth of field	d1
		Height	d2
Pole of the motor	O
		First ray	M
Second ray	N
		Intersection point	P、Q
Curve line	X、Y
		Film material
	20
		Diameter of opening	D1、D2

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

Example one

Referring to fig. 1, a molding apparatus 10 provided in this embodiment includes a bearing portion 11 and a molding portion 12 combined on the bearing portion 11.

As shown in fig. 1, the carrying portion 11 is provided with a groove 111, and the groove 111 is used for accommodating a product to be formed. The groove 111 has a bottom wall 112, a side wall 113 connected to the bottom wall 112, and an opening 114 away from the bottom wall 112. The forming portion 12 is disposed on the bottom wall 112 of the groove 111, and the forming portion 12 is accommodated in the groove 111. The profile 12 is spaced from the side wall 113 of the recess 111.

In this embodiment, the bearing portion 11 and the forming portion 12 are integrally formed, and the integrally forming manner may include but is not limited to: 3D prints, injection moulding, and it is higher to adopt integrated into one piece's mode efficiency. In another embodiment, the forming portion 12 is detachably coupled to the bottom wall 112 of the recess 111, and the detachable manner includes but is not limited to: sticky, locked with fasteners (e.g., bolts). When the device is arranged in a detachable mode, the bearing part 11 or the forming part 12 in one forming device can be replaced, different bearing parts 11 and different forming parts 12 can be matched and combined, and the utilization flexibility of parts is improved.

As shown in fig. 1, the forming portion 12 has a top surface 121 away from the bottom wall 112 of the recess 111. When the molding apparatus 10 is used to process a product to be molded, the top surface 121 is used to carry the product to be molded, and the product to be molded is attached to the top surface 121 and pressed. The contour of the edge of the top surface 121 is the same as the contour of the opening 114 of the groove 111.

As shown in fig. 1, in the molding apparatus 10 of the present embodiment, the top surface 121 of the molding part 12 has an irregular shape, and the contour of the opening 114 of the groove 111 is set to be the same as the edge contour of the top surface 121. In this embodiment, the bearing part 11 is provided in a hollow cylindrical shape, and in order to keep the contour of the opening 114 of the groove 111 the same as the contour of the edge of the top surface 121 and an irregular contour, the wall thickness of the bearing part 11 is not uniform. The present invention is not limited to the overall shape of the carrying portion 11, and in other embodiments, it is considered to adjust the outer appearance of the forming device 10 so that the wall thickness of the carrying portion 11 can be set to be equal.

Referring to fig. 2, the top surface 121 is a curved surface. In this embodiment, the top surface 121 is a curved surface that is recessed toward the bottom wall 112 of the groove 111. In other embodiments, the top surface 121 may be a curved surface protruding away from the bottom wall 112 of the groove 111, and in another embodiment, the top surface 121 may also be a plane. The shape of the top surface 121 is determined according to the shape of the target molded article, the outline of the opening 114 of the groove 111 is determined by the outline of the edge of the top surface 121, and the size of the opening of the groove 111 is larger than the area of the top surface 121.

The relationship between the profile of the opening 114 of the groove 111 and the profile of the edge of the top surface 121 of the profile 12 will be further explained below:

referring to fig. 2 and 3, the outline of the opening 114 and the outline of the edge of the top surface 121 are orthographically projected on the bottom wall 112 of the groove 111 to form a projection pattern as shown in fig. 3, there are a curve X and a curve Y respectively, where the curve X is the projection pattern of the outline of the opening 114 on the bottom wall 112, and the curve Y is the projection pattern of the outline of the edge of the top surface 121 on the bottom wall 112.

Referring to fig. 3, a polar coordinate system is established on a plane where the projection pattern is located, a geometric center of the pattern surrounded by the curve Y is taken as a pole, the pole is represented as O, a first ray M is led out from any direction of the pole O as a polar axis, a second ray N is led out from any direction of the pole O, and the second ray N has an intersection with the curve X and the curve Y. The intersection point of the second ray N and the curve X is represented as P, the coordinate of the point P is represented as (rho 1, theta 1), wherein rho 1 represents the distance between the pole O and the point P, and theta 1 represents the included angle between the connecting line of the point P and the pole O and the first ray M; the intersection point of the second ray N and the curve Y is Q, and the coordinate of the point Q is represented by (ρ 2, θ 2), where ρ 2 represents the distance between the pole O and the point Q, and θ 2 represents the angle between the connecting line of the point Q and the pole O and the first ray M. The coordinates of the point P and the point Q satisfy the following relationship:

θ 1 is the angle between the first ray M and the second ray N, ρ 1 is sxρ 2, and S > 1, that is, ρ 1 is greater than ρ 2.

That is, the profile of the opening 114 of the groove 111 is the same as the profile of the edge of the top surface 121, and is enlarged on the basis of the top surface 121.

In one embodiment, the profile of the opening 114 of the groove 111 is the same as the profile of the edge of the top surface 121, and S ≧ 1.5; in another embodiment, S is 1.5 ≦ 1.75.

Referring to fig. 4, the molding apparatus 10 of the present embodiment is used for thermoforming to form a target molded object (not shown), which is an optical film. In the forming process, the film material 20 is first placed on the carrier portion 11, and the film material 20 does not enter the groove 111, and then pressure is applied to a side (in the direction indicated by the parallel arrows in fig. 4) of the film material 20 away from the forming portion 12, so that the film material 20 enters the groove 111 and finally abuts against the top surface 121 of the forming portion 12. The film material 20 may be softened by heating before entering the groove 111, or may be softened by heating after entering the groove 111, so that the softened film material 20 is pressed against the top surface 121 of the forming part 12 and is pressed to form the shape of the top surface 121. In this embodiment, the pressure is applied by applying pressure directly to the film material 20 with a mechanical ram.

In order to provide a space for accommodating the mechanical ram, in the present embodiment, the side wall 113 of the groove 111 is perpendicular to the plane of the bottom wall 112, and the height of the side wall 113 is equal at all positions. The depth d1 of the groove (i.e., the height of the side wall 113) is greater than the maximum height d2 of the forming section 12 (the forming section 12 is a curved surface, and has different heights at different places, and thus has the maximum height).

In other embodiments, the pressure may be applied by air pressure, hydraulic pressure, or the like, and the present invention is not limited thereto.

Referring to fig. 5, the film material 20 is pressed against the top surface 121 of the molding portion 12 while the pressure is kept. The portion of the film material 20 that is closely attached to the top surface 121 of the molding portion 12 is the target molded object, and the rest is the waste material. To form a target shaped article of a desired shape, the top surface 121 of the mold section 12 is configured to conform to the shape of the target shaped article. In this embodiment, the top surface 121 of the molding portion 12 is a curved surface, and the target molded object is a curved optical film.

In the molding apparatus 10 provided by the present embodiment, by setting the contour of the opening 114 of the groove 111 to be the same as the contour of the edge of the top surface 121 of the molding portion 12, when the film material 20 is extruded in the thermoplastic molding process, the stress at the edge of the film material 20 is relatively small, and the stress on the entire stress-bearing surface is relatively balanced, which helps to keep the structure of the film material 20 unchanged, so that the film material 20 maintains the original characteristics. Therefore, it is beneficial to improve the problem that the film material 20 is pulled due to too strong stress during the thermoplastic forming process, and the structure changes, so that the optical characteristics are affected.

The following is a comparison of the effect of the molding apparatus of the comparative example and the molding apparatus 10 in the present case:

please refer to table one: table one shows the relationship between the pressure applied to the film material and the stress at the edge of the film material, using the molding apparatus of the comparative example (the opening of the groove of the carrier part is circular, the molding part is identical to the above-described molding part 12, and the top surface is irregularly shaped). In the table i, taking the opening of the forming device as a cylinder as an example, two sets of data of 65mm and 70mm opening diameters are shown:

watch 1

Please refer to table two: table two shows the relationship between the pressure applied to the film material 20 and the stress at the edge of the film material 20 by using the molding apparatus 10 of the present embodiment. Table two shows two sets of data at the enlarged scale of 1.5 (i.e., S ═ 1.5) and 1.75 (i.e., S ═ 1.75) of the opening 114 of the groove 111 relative to the top surface 121 of the mold 12:

watch two

Referring to the fifth set of data in table one, the first set of data in table two, and the sixth set of data in table two, the stress applied to the edge of the film material 20 was 0.3, and when the stress applied to the film material 20 was 0.3, the stress at the edge of the film material was 4.4141% (the first set of data in table one) using the comparative example forming apparatus, whereas when the forming apparatus 10 in this case was used, the stress at the edge of the film material 20 was 2.4588% (the first set of data in table two) and 2.5087% (the sixth set of data in table two), it was shown that when the same pressure was applied to the film material, the stress at the edge of the film material was smaller using the forming apparatus 10 in this case than using the comparative example forming apparatus.

Further, referring to the first set of data in table one and the first set of data in table two, the edge stress of the film material reached 2.4588% when the forming apparatus of the comparative example was used to apply a pressure of 0.138 to the film material, whereas the edge stress of the film material 20 was consistent with that of the comparative example when the forming apparatus 10 of the present application was used to apply a pressure of 0.3 to the film material 20. It is noted that if the edge of the film material can withstand 2.4588% stress in one embodiment, the film material can withstand a greater range of pressures using the forming apparatus 10 of the present application than using the forming apparatus of the comparative example.

According to the above analysis, the molding apparatus 10 of the present embodiment can effectively improve the problem that the optical characteristics of the film material are affected by the stress on the film material 20 in the thermoplastic molding process by setting the profile of the opening 114 of the groove 111 to be the same as the profile of the edge of the top surface 121 of the molding portion 12.

It will be appreciated by those skilled in the art that the above embodiments are illustrative only and not intended to be limiting, and that suitable modifications and variations may be made to the above embodiments without departing from the true spirit and scope of the invention.

Claims

1. A molding apparatus, comprising:

the bearing part is used for bearing a product to be molded, a groove is arranged on the bearing part, and the groove is provided with a bottom wall and a side wall connected with the bottom wall; and

the forming part is arranged on the bottom wall and is spaced from the side wall, the depth of the groove is greater than the height of the forming part, the forming part is provided with a top surface far away from the bottom wall, the contour of the top surface is consistent with that of a target formed object, and the top surface is used for bearing the product to be formed and forming the product to be formed into the target formed object under the action of pressure;

the contour of the opening of the groove and the projection pattern of the top surface formed on the bottom wall of the groove satisfy the following relationship:

establishing a polar coordinate system on the projection plane, taking the geometric center of the projection graph of the top surface as a pole, expressing the coordinates of the points of the projection graph of the outline of the opening as (rho 1, theta 1), expressing the coordinates of the points of the projection graph of the outline of the top surface as (rho 2, theta 2), expressing the distances between the points and the pole, and expressing the theta 1 and the theta 2 as included angles between a connecting line between the points and the pole and a polar axis;

when θ 1 is θ 2, ρ 1 is sxρ 2, and S > 1.

2. The molding apparatus as defined in claim 1, wherein:

S≥1.5。

3. the molding apparatus as defined in claim 1, wherein:

1.5≤S≤1.75。

4. the molding apparatus as defined in claim 1, wherein said top surface of said molding portion is a curved surface.

5. The molding apparatus as defined in claim 1, wherein said top surface of said molding section is a flat surface.

6. The molding apparatus as defined in claim 1, wherein said carrier portion and said molding portion are integrally molded.

7. The molding apparatus as defined in claim 1, wherein said molding portion is detachably provided to a bottom wall of said recess.