CN211165037U - Mobile phone rear cover blank forming die with hydraulic device and comprising middle frame - Google Patents

Abstract

The utility model provides a mobile phone back cover blank forming mold with a self-contained hydraulic device and including a middle frame, which comprises a movable mold and a fixed mold. The movable mold core has five molding surfaces, and the surrounding four molding surfaces are The included angle between the middle molding surfaces is greater than or equal to 90 degrees, the fixed mold core has five molding surfaces, and the included angle between the four surrounding molding surfaces and the middle molding surface is greater than or equal to 90 degrees. The utility model has its own hydraulic device and includes a middle frame for the mobile phone back cover blank forming mold, which improves the production performance of the injection molding machine because the hydraulic device is provided. The back cover of the mobile phone and the middle frame of the mobile phone are integrated to reduce costs. Due to the cold material cavity, the cold material can be prevented from affecting the quality of the formed product. Because of the movable cavity, the volume of the movable cavity before the compression stops is larger than the volume of the product, the liquid material in the movable cavity flows evenly, and it is easy to form, and the product has good internal stress, beautiful appearance, uniform thickness, and the composite materials are not easy to interact with each other. separation.

Description

A mobile phone back cover blank forming die including a middle frame with a self-contained hydraulic device

technical field

The utility model relates to a blank forming die, in particular to a mobile phone back cover blank forming die with a hydraulic device and a middle frame.

Background technique

Injection mold is a tool for producing plastic products, and it is also a tool for giving plastic products complete structure and precise dimensions. Injection molding is a processing method used in the mass production of some complex-shaped parts. Specifically, it refers to the injection of the heated and melted plastic into the cavity of the injection molding machine at high pressure, and after cooling and solidification, a molded product is obtained.

The injection mold consists of a movable mold and a fixed mold. The movable mold is installed on the moving template of the injection molding machine, and the fixed mold is installed on the fixed template of the injection molding machine. Both the movable mold and the fixed mold form a fixed cavity. The size cannot be changed. During injection molding, the movable mold and the fixed mold are closed to form a gating system and a cavity. When the mold is opened, the movable mold and the fixed mold are separated to take out the plastic product. In order to reduce the heavy workload of mold design and manufacturing, most of the injection molds use standard mold bases.

At present, the molds for product molding in the mold industry all use glue injection into a fixed cavity. The volume of the fixed cavity is the same as the volume of the product. During the molding process, the fixed cavity is too small, which leads to the flow of raw materials. The resistance is large and it is not easy to form. In order to achieve product forming, the injection pressure and injection speed must be increased, which leads to large internal stress of the formed product, poor appearance, uneven thickness, and easy separation of composite materials, resulting in poor product quality. , Low yield.

Utility model content

Based on the deficiencies of the prior art, the purpose of the present invention is to provide a mobile phone back cover blank forming mold with a hydraulic device and a middle frame. Because the hydraulic device is provided, the production performance of the injection molding machine is improved; Both the mold core and the fixed mold core are provided with five molding surfaces, and the maximum distance between the four molding surfaces around the movable mold core and the combination of the inserts ≥ the distance between the movable mold core and the fixed mold core The minimum distance between the back cover of the mobile phone and the middle frame of the mobile phone is integrated, which is very natural and reduces the cost, and the appearance of the blank of the mobile phone back cover of the middle frame integrated mobile phone is more beautiful than that of the non-integrated one; due to the cold material cavity, the cooling liquid The raw material easily flows to the cold material cavity, so as to avoid the cold material affecting the quality of the molded product; because of the movable cavity, the volume of the movable cavity before the compression stops is larger than the volume of the product, and the back cover and the middle frame of the molded mobile phone outside the cold material cavity The liquid raw material in the movable cavity flows evenly, the back cover and the middle frame of the mobile phone are easy to form at low speed or low pressure, and the product has good internal stress, beautiful appearance, uniform thickness, and the composite materials are not easy to separate from each other.

In order to achieve the above purpose, the present invention provides a mobile phone back cover blank forming mold with a hydraulic device and a middle frame, which includes a movable mold, a fixed mold and a guide assembly, and the movable mold is provided with a movable mold support device. , the fixed mold is provided with a fixed mold support device, the moving mold and the fixed mold cooperate with each other through the guide assembly, the moving mold is provided with a moving mold core, and the moving mold includes a second moving mechanism and a limiting device, and also includes a hydraulic device, a connecting piece, a guiding device, a water channel device, a cold material cavity and a positioning structure, and the moving mold core is movably connected to the moving mold through the connecting piece and the hydraulic device, A second moving mechanism is composed of the hydraulic device, the guiding device, the moving mold core and the connecting piece, and the second moving mechanism passes through the guiding device, the limiting device and the The movable mold is movably connected, the mold core of the movable mold is positioned on the support device through the positioning structure, the mold core of the fixed mold is positioned on the support device through the positioning structure, and the water channel device is distributed In the movable mold and the fixed mold, the movable mold core has five molding surfaces, and the included angle between the four surrounding molding surfaces and the middle molding surface is greater than or equal to 90 degrees, and the fixed mold core has five molding surfaces. The mold core has five molding surfaces, and the included angle between the four surrounding molding surfaces and the middle molding surface is greater than or equal to 90 degrees.

As an improvement of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device, the mobile phone back cover blank forming mold with its own hydraulic device and including the middle frame also includes an exhaust device. The second moving mechanism includes a moving carrying device, an insert assembly and a connecting piece, the inserting assembly is fixed on the moving carrying device through the connecting piece, the inserting assembly, the moving mold core and the connecting piece. The fixed mold core forms a movable cavity, the exhaust device is arranged around the movable cavity, and the insert assembly is directly or indirectly positioned on the support device through the positioning structure, and the positioning structure is located on one side of the movable cavity, the cold material cavity is located on the other side of the movable cavity and communicates with the movable cavity, there are one or two cold material cavities, and the moving mold The maximum distance between the four molding surfaces around the core and the insert combination is T3, and the maximum distance between the four molding surfaces of the fixed mold core and the four molding surfaces around the adjacent moving mold core is T4. The distance between the mold core and the fixed mold core is T5, and T4=T3≥T5.

As an improvement of the mobile phone back cover blank forming mold including a middle frame with its own hydraulic device in the present invention, the exhaust device of the mobile phone back cover blank forming mold with a self-contained hydraulic device and including a middle frame includes a gas a groove, an exhaust gap and an exhaust channel, the exhaust gap communicates with the air groove, the exhaust gap is divided into two or more, and the size of each exhaust gap is based on the exhaust The gap is set according to the position of the mold where the gap is located. A triangle, an isosceles triangle or an equilateral triangle is formed between one of the positioning structures and the two cold material cavities, and the cold material cavity is located in the fixed mold. Between the mold core and the insert assembly, the cavity of the cold material cavity is mainly located in the fixed mold core or the insert assembly.

As an improvement of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention, the size of the exhaust gap of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device The size of the exhaust gap varies sequentially from the closest end from the feed port of the mold to the farthest end from the feed port of the mold, or the size of the exhaust gap varies sequentially from the position where the mold is the easiest to form to the most difficult position for the mold to form.

As an improvement of the mobile phone back cover blank forming die including the middle frame with its own hydraulic device of the present invention, the positioning of the mobile phone back cover blank forming die with its own hydraulic device and including the middle frame includes a nozzle insert. The nozzle insert is installed at the center position of the fixed mold through the positioning pin, and the feed port insert is installed at the center position of the movable mold through the positioning pin.

As an improvement of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention, the movable cavity of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device is a or more than one.

As an improvement of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention, the size of the exhaust gap of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device For L, 0.005mm≤L≤0.08mm.

As an improvement of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention, the size of the exhaust gap of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device For L, 0.005mm≤L≤0.05mm.

Compared with the prior art, the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention has the following beneficial effects: the production performance of the injection molding machine is improved due to the hydraulic device; and the fixed mold core are provided with five molding surfaces, and the maximum distance between the four molding surfaces around the movable mold core and the combination of the inserts ≥ the minimum distance between the movable mold core and the fixed mold core , the back cover of the mobile phone and the middle frame of the mobile phone are integrated, which is excessively natural and reduces the cost, and the appearance of the blank of the mobile phone back cover of the middle frame integrated mobile phone is more beautiful than that of the non-integrated one; due to the cold material cavity, the cooled liquid material is easy to flow. To the cold material cavity, to prevent the cold material from affecting the quality of the molded product; because of the movable cavity, the volume of the movable cavity before it stops compressing is greater than the volume of the product. The liquid raw material in the cavity flows evenly, the back cover and the middle frame of the mobile phone are easy to form at low speed or low pressure, and the product has good internal stress, beautiful appearance, uniform thickness, and the composite materials are not easy to separate from each other.

Description of drawings

FIG. 1 is a schematic structural diagram of a movable mold in a preferred embodiment of a mobile phone back cover blank forming mold with a self-contained hydraulic device including a middle frame of the present invention.

FIG. 2 is a schematic structural diagram of a fixed mold in a preferred embodiment of a mobile phone back cover blank forming mold with a self-contained hydraulic device including a middle frame of the present invention.

FIG. 3 is a schematic structural diagram of step 1 in a preferred embodiment of a mobile phone back cover blank forming die with a self-contained hydraulic device including a middle frame of the present invention.

4 is a schematic structural diagram of step 3 in the preferred embodiment of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device according to the present invention.

FIG. 5 is a schematic structural diagram of step 4 in the preferred embodiment of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device according to the present invention.

6 is an enlarged view of W in step 4 in the preferred embodiment of the mobile phone back cover blank forming die including the middle frame with its own hydraulic device of the present invention.

7 is a schematic structural diagram of step 5 in the preferred embodiment of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device according to the present invention.

8 is a schematic structural diagram of step 6 in the preferred embodiment of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device according to the present invention.

9 is a schematic structural diagram of step 7 in the preferred embodiment of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention.

FIG. 10 is a schematic structural diagram of step 8 in the preferred embodiment of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention.

11 is a transverse cross-sectional view of the molding die in the preferred embodiment of the mobile phone back cover blank molding die including the middle frame with its own hydraulic device according to the present invention.

12 is an enlarged view of H in the transverse cross-sectional view of the forming die in the preferred embodiment of the mobile phone back cover blank forming die including the middle frame with its own hydraulic device of the present invention.

13 is a vertical cross-sectional view of the molding die in the preferred embodiment of the mobile phone back cover blank molding die including the middle frame with its own hydraulic device according to the present invention.

Detailed ways

The mobile phone back cover blank forming mold including the middle frame and the self-contained hydraulic device of the utility model is suitable for producing thin-walled products, battery back covers, mobile phone cases or optical products, and the materials used are high-viscosity materials or low-viscosity materials. Composite materials that are easily separated from each other or composite materials that are easily separated from each other.

Referring to Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 10, Figure 11, Figure 12 and Figure 13, the utility model self-contained hydraulic device is described in detail. The preferred embodiment and other embodiments of the blank forming mold for the back cover of the mobile phone including the middle frame.

The utility model provides a mobile phone back cover blank forming die with a hydraulic device and a middle frame, which is characterized in that it comprises a movable die 1, a fixed die 2 and a guide assembly 3, and the movable die 1 is provided with a movable die Support device 1.10, the fixed mold 2 is provided with a fixed mold support device 2.4, the movable mold 1 and the fixed mold 2 cooperate with each other through the guide assembly 3, and the movable mold 1 is provided with a movable mold core 1.4, The fixed mold 2 is provided with a fixed mold core 2.1, and the movable mold 1 includes a second moving mechanism 1.1 and a limiting device 1.2, as well as a hydraulic device 1.1.1, a connector 1.1.3, and a guide device 1.1. 4. The water channel device 5, the cold material cavity F and the positioning structure 6, the core of the moving mold 1 is movably connected to the moving mold 1 through the connecting piece 1.1.3 and the hydraulic device 1.1.1. The device 1.1.1, the guiding device 1.1.4, the moving die 1 core and the connecting piece 1.1.3 constitute a second moving mechanism 1.1, and the second moving mechanism 1.1 passes through the guiding device 1.1. 4. The limiting device 1.2 is movably connected with the movable mold 1, the mold core 1.4 of the movable mold 1 is positioned on the support device 1.10 through the positioning structure 6, and the mold core 2.1 of the fixed mold 2 is positioned on the supporting device 1.10. The positioning structure 6 is positioned on the support device 2.4, the water channel device 5 is distributed in the movable mold 1 and the fixed mold 2, and the mold core 1.4 of the movable mold 1 has five molding surfaces, The angle between the four surrounding molding surfaces 1.4.1 and the middle molding surface 1.4.2 is greater than or equal to 90 degrees, the fixed mold 2 core 2.1 has five molding surfaces, and the surrounding four molding surfaces 2.1. The angle between 1 and the middle molding surface 2.1.2 is greater than or equal to 90 degrees.

In this embodiment, the mobile phone back cover blank forming mold with its own hydraulic device and including the middle frame also includes an exhaust device (not marked in the drawings), and the second moving mechanism 1.1 includes the The hydraulic device 1.1.1, the guide device 1.1.4, the moving mold core 1.4 and the connecting piece 1.1.3 are fixed on the moving carrying device 1.10, the insert combination 9, the moving mold 1. The mold core 1.4 and the fixed mold 2. The mold core 2.1 form a movable cavity, the exhaust device is arranged around the movable cavity, and the insert combination 9 is directly or indirectly positioned through the positioning structure 6 on the movable cavity. On the support device, the positioning structure 6 is located on one side of the movable cavity, and the cold material cavity F is located on the other side of the movable cavity and communicates with the movable cavity. There are one or two cavities F, the maximum distance between the four molding surfaces 1.4.1 around the movable mold core 1.4 and the insert combination 9 is T3, and the four molding surfaces 2.1 of the fixed mold core 2.1. The maximum distance between 1 and the four molding surfaces 1.4.1 around the adjacent movable mold core 1.4 is T4, and the distance between the movable mold core 1.4 and the fixed mold core 2.1 is T5, T4 =T3≥T5.

In the present embodiment, the exhaust device (not marked in the drawings) of the mobile phone back cover blank forming mold including the middle frame of the present invention with its own hydraulic device includes an air groove (not marked in the drawings) , an exhaust gap (not marked in the drawings) and an exhaust channel (not marked in the drawings), the exhaust gap is communicated with the air groove, and the exhaust gap is divided into two or more , the size of each exhaust gap is set according to the position of the mold where the exhaust gap is located, and a triangle, an isosceles triangle, or a triangle between one of the positioning structures 6.2 and the two cold material cavities F is presented. Close to the shape of an equilateral triangle, the cold material cavity is located between the fixed mold 2 core and the insert assembly 9, and the cavity of the cold material cavity is mainly located in the fixed mold 2 core or the Inside the insert combination 9.

In this embodiment, the size of the exhaust gap of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention is from the nearest end from the feed port of the mold to the most from the feed port of the mold. The distal end is changed sequentially or the size of the vent gap is changed sequentially from the position where the mold is the easiest to mold to the position where the mold is the most difficult.

In this embodiment, the positioning structure 6 of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention includes a nozzle insert 6.1, a feed port insert 6.2 and a positioning pin 6.3. The nozzle insert 6.2 is installed at the center position of the fixed mold 2 through the positioning pin 6.3, and the feed port insert 6.2 is installed at the center position of the movable mold 1 through the positioning pin 6.3.

In the present embodiment, there are two movable cavities of the mobile phone back cover blank forming mold including the middle frame of the present invention with its own hydraulic device.

In other embodiments, the movable cavity of the mobile phone back cover blank forming mold including the middle frame with the hydraulic device of the present invention is one.

In other embodiments, there are more than two movable cavities of the mobile phone back cover blank forming mold including the middle frame with its own hydraulic device of the present invention.

In the present embodiment, the size of the exhaust gap of the mobile phone back cover blank forming mold including the middle frame with the hydraulic device of the present invention is L, 0.005mm≤L≤0.05mm.

In other embodiments, the size of the exhaust gap of the mobile phone back cover blank forming mold including the middle frame with the hydraulic device of the present invention is L, 0.005mm≤L≤0.08mm.

The working process of the mobile phone back cover blank forming mold including the middle frame and the self-contained hydraulic device of the utility model uses the easily separable composite material to produce the mobile phone back cover as follows:

The back cover of the mobile phone needs to have the performance of high hardness and high strength at the same time.

Polymethyl methacrylate, or poly methyl methacrylate, referred to as PMMA, also known as acrylic, acrylic or plexiglass, has high transparency and brightness, good heat resistance, and has the characteristics of toughness, hardness and rigidity. As the molding material for the back cover of the mobile phone, it can meet the use effect of wear resistance and less scratches of the back cover of the mobile phone.

Polycarbonate, referred to as PC, is a high molecular polymer containing carbonate groups in the molecular chain. It is a tough thermoplastic resin with good impact resistance. It can be used as a raw material for mobile phone back covers to meet the requirements of drop and crack resistance of mobile phone back covers. use effect.

In order to meet the high hardness and strength of the mobile phone back cover at the same time, PMMA+PC composite material can be used to form the mobile phone back cover. However, in the traditional PMMA+PC composite material molding process, the injection speed range is above 500mm/s, and the pressure range is 2800-3000kgf/cm ² , due to the fast injection speed and high pressure, PMMA and PC are easily separated from each other, forming difficulty and low yield.

The mobile phone back cover blank forming die including the middle frame of the utility model with its own hydraulic device can be formed under the condition of low speed and low pressure compared with the traditional forming process due to the use of the movable cavity. Smaller, PMMA and PC are not easy to be separated from each other, the molding difficulty becomes smaller, and the yield rate is greatly improved.

The process of producing the mobile phone back cover by using the PMMA+PC composite material for the mobile phone back cover blank forming mold including the middle frame and the utility model with its own hydraulic device is as follows:

The first step is to dry the PMMA+PC composite material and transport it to the injection molding machine to convert the PMMA+PC composite material from a solid state to a liquid state.

The second step is to adjust the temperature of the corresponding parts of the mold to achieve the best molding conditions for the mobile phone back cover blank in the middle frame. .2, the temperature of the surrounding molding surface 2.1.1 of the fixed mold core 2.1 is lower than the temperature of the intermediate molding surface 2.1.2 of the fixed mold core 2.1, and the temperature of the insert combination 9 is lower than that of the movable mold core 1.4 The intermediate molding surface The temperature of 1.4.2 or lower than the temperature of the intermediate molding surface 2.1.2 of the fixed mold core 2.1.

The third step is to move the moving mold 1 to the fixed mold 2 to start mold clamping.

The fourth step consists of the fixed mold 2, the insert combination 9 and the second moving mechanism 1.1 to form the movable cavity A, the fixed mold core 2.1 and the insert combination 9 to form the cold material cavity F, and the movable cavity has the largest volume at this time. , the maximum distance between the four molding surfaces 1.4.1 around the moving mold core 1.4 and the insert combination 9 is T3, the four molding surfaces 2.1.1 of the fixed mold core 2.1 and the adjacent moving mold core 1.4 around The maximum distance between the four molding surfaces 1.4.1 is T4.

(5) Inject liquid raw material into the movable cavity A, start the hydraulic device 1.1.1, and start compression. At this time, the movable cavity is C, the feeding speed is 300mm/s, and the feeding pressure is 1800kgf/cm ² .

(6) The volume of the movable cavity changes from large to small to the required volume of the mobile phone back cover blank including the middle frame to form the movable cavity E. At this time, the distance between the movable mold core 1.4 and the fixed mold core 2.1 is T5, T4=T3≥T5.

(7) The product is cooled and formed, the moving mold 1 is moved back, the second moving mechanism 1.1 is moved back, the mold is opened, and the product is taken out.

(8) The moving mold core 1.4 retreats under the action of the spring, pneumatic or electric device 10, and the hydraulic device 1.1.1 returns to its original position.

The volume of the movable cavity A>the volume of the movable cavity C>the volume of the movable cavity E.

Compared with the prior art, the utility model has the following beneficial effects: because the hydraulic device is provided, the production performance of the injection molding machine is improved; The maximum distance between the four molding surfaces around the mold core and the combination of the inserts ≥ the minimum distance between the moving mold core and the fixed mold core, so that the back cover of the mobile phone and the middle frame of the mobile phone are integrated, which is excessively natural. Costs are reduced, and the appearance of the blanks for the back cover of the middle-frame integrated mobile phone is more beautiful than that of the non-integrated ones; due to the cold material cavity, the cooled liquid raw material can easily flow to the cold material cavity, so as to avoid the cold material affecting the quality of the molded product; There is a movable cavity, so that the volume of the movable cavity before it stops compressing is larger than the volume of the product. The liquid raw material in the movable cavity of the mobile phone back cover and the middle frame outside the cold material cavity flows evenly, and the mobile phone back cover and the middle frame are formed at low speed. Or easy to form under low pressure, and the product has good internal stress, beautiful appearance, uniform thickness, and composite materials are not easy to separate from each other.

What is disclosed above is only the preferred embodiment of the present invention, of course, it cannot limit the scope of rights of the present invention. Therefore, the equivalent changes made according to the scope of the present invention are still covered by the present invention. scope.

Claims (11)

1. a mobile phone back cover blank forming mold comprising a middle frame with a self-contained hydraulic device is characterized in that, it comprises a moving mold, a fixed mold and a guide assembly, and the moving mold is provided with a moving mold supporting device, and the fixed The mold is provided with a fixed mold support device, the moving mold and the fixed mold cooperate with each other through the guide assembly, the moving mold is provided with a moving mold core, and the moving mold includes a second moving mechanism and a limiting device , and also includes a hydraulic device, a connecting piece, a guiding device, a water channel device, a cold material cavity and a positioning structure, the moving mold core is movably connected with the moving mold through the connecting piece, the hydraulic device, and the hydraulic The device, the guiding device, the moving mold core and the connecting piece form a second moving mechanism, and the second moving mechanism is movably connected to the moving mold through the guiding device and the limiting device , the mold core of the moving mold is positioned on the support device through the positioning structure, the mold core of the fixed mold is positioned on the support device through the positioning structure, and the water channel device is distributed in the moving In the mold and in the fixed mold, the movable mold core has five molding surfaces, and the angle between the four surrounding molding surfaces and the middle molding surface is greater than or equal to 90 degrees, and the fixed mold core has Five molding surfaces, the angle between the four surrounding molding surfaces and the middle molding surface is greater than or equal to 90 degrees. 2. The mobile phone back cover blank molding die comprising a middle frame with a self-contained hydraulic device according to claim 1, characterized in that: further comprising an exhaust device, and the second moving mechanism comprises a mobile carrying device, an insert combination and a connecting piece, the insert assembly is fixed on the moving carrying device through the connecting piece, the insert assembly, the moving mold core and the fixed mold core form a movable cavity, and the row The air device is arranged around the movable cavity, the insert assembly is directly or indirectly positioned on the support device through the positioning structure, the positioning structure is located on one side of the movable cavity, and the cooling The material cavity is located on the other side of the movable mold cavity and communicates with the movable mold cavity. There are one or two cold material cavities, and the four molding surfaces around the movable mold core and the insert combination are between The maximum distance is T3, the maximum distance between the four molding surfaces of the fixed mold core and the four molding surfaces around the adjacent moving mold core is T4, and the distance between the moving mold core and the fixed mold core is T5, T4=T3≥T5. 3. The mobile phone back cover blank molding die including the middle frame with the self-contained hydraulic device according to claim 2 is characterized in that: the exhaust device comprises an air groove, an exhaust gap and an exhaust channel, and the exhaust The gap is communicated with the air groove, the exhaust gap is divided into two or more, and the size of each exhaust gap is set according to the position of the mold where the exhaust gap is located. The structure and the two cold material cavities are in the shape of triangle, close to isosceles triangle or close to equilateral triangle, the cold material cavity is located between the fixed mold core and the combination of the inserts, the cold material cavity is The cavity of the material cavity is mainly located in the fixed mold core or the insert assembly. 4. The mobile phone back cover blank forming mould comprising the middle frame with the self-contained hydraulic device according to claim 3, is characterized in that: the size of the exhaust gap is from the nearest end of the feed port of the mould to the inlet of the mould. The farthest end of the material port changes sequentially or the size of the exhaust gap changes sequentially from the position where the mold is the easiest to form to the position where the mold is the most difficult. 5. The mobile phone back cover blank molding die comprising a middle frame with a self-contained hydraulic device according to claim 1, characterized in that: the positioning structure comprises a nozzle insert, a feed port insert and a positioning pin, the The nozzle insert is installed at the center position of the fixed mold through the positioning pin, and the feed port insert is installed at the center position of the movable mold through the positioning pin. 6. The mobile phone back cover blank molding die comprising a middle frame with a self-contained hydraulic device according to claim 2, characterized in that: the positioning structure comprises a nozzle insert, a feed port insert and a positioning pin, the The nozzle insert is installed at the center position of the fixed mold through the positioning pin, and the feed port insert is installed at the center position of the movable mold through the positioning pin. 7. The mobile phone back cover blank forming die comprising a middle frame with a self-contained hydraulic device according to claim 3, characterized in that: the positioning structure comprises a nozzle insert, a feed port insert and a positioning pin, the The nozzle insert is installed at the center position of the fixed mold through the positioning pin, and the feed port insert is installed at the center position of the movable mold through the positioning pin. 8. The mobile phone back cover blank forming die including a middle frame with a self-contained hydraulic device according to claim 4, characterized in that: the positioning structure comprises a nozzle insert, a feed port insert and a positioning pin, the The nozzle insert is installed at the center position of the fixed mold through the positioning pin, and the feed port insert is installed at the center position of the movable mold through the positioning pin. 9 . The mobile phone back cover blank forming mold with a self-contained hydraulic device and including a middle frame according to claim 8 , wherein the movable cavity is one or more than one. 10 . 10 . The mobile phone back cover blank forming die with a self-contained hydraulic device and a middle frame according to claim 9 , wherein the size of the exhaust gap is L, and 0.005mm≦L≦0.08mm. 11 . 11 . The mobile phone back cover blank forming die with a self-contained hydraulic device and a middle frame according to claim 10 , wherein the size of the exhaust gap is L, and 0.005mm≦L≦0.05mm. 12 .

Images