Multi-material in-mold forming mold and forming preparation method

Abstract

The invention belongs to the technical field of in-mold forming, and particularly relates to a multi-material in-mold forming mold and a forming preparation method.The multi-material in-mold forming mold comprises an injection rod, an upper mold body and a lower mold body, the upper mold body and the lower mold body are matched with each other, an opening of the lower mold body faces upwards, an opening of the upper mold body faces downwards, at least three through holes are formed in the bottom wall of the lower mold body, a lifting device is arranged outside the lower mold body, and the execution end of the lifting device is connected with the injection rod; a first sealing ring matched with the injection rod is coaxially arranged at each through hole in the lower mold, the top end of the injection rod penetrates through the through hole and extends into the lower mold, an injection hole is radially formed in the circumferential surface of the injection rod and is close to the top end, an opening is formed in one end, outside the lower mold, of the injection rod, and a switch door is arranged at the injection hole in a matched manner on the injection rod; according to the mold, the situation that the part needing to be wrapped sinks in the mold due to the gravity of the part, and the included silica gel is thin is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of in-mold forming, and specifically relates to a multi-material in-mold forming mold and a forming preparation method. Background Art

[0002] Multi-material molding is a special part that can be molded into one piece in a mold by silicone-wrapped silver-plated bronze or silicone-wrapped ceramics through a specific process. This part is mainly used in refrigeration equipment for base stations and large servers. However, when making it, if it is fully wrapped, that is, the silicone completely covers the entire silver-plated bronze or ceramic part, it needs to be done in two steps. First, half of the surface of the entire silver-plated bronze or ceramic part is wrapped in the mold, and then the other half is included after solidification. In the process of wrapping, liquid silicone needs to be injected into the mold first, and then the entire silver-plated bronze or ceramic part is placed in the mold filled with liquid silicone, and then heated to solidify the liquid silicone. However, since the entire silver-plated bronze or ceramic part has weight, it is easy to cause the thickness of the silicone wrap to be insufficient. Summary of the invention

[0003] The purpose of this application is mainly to address the shortcomings of the prior art. By inserting an injection rod for supporting the parts to be wrapped on the bottom wall of the lower mold, a multi-material in-mold molding mold and a molding preparation method are designed, so that the parts to be wrapped will not sink in the mold due to their own gravity, resulting in a relatively thin silicone.

[0004] In order to achieve the above purpose, the technical solution adopted in this application is:

[0005] A multi-material in-mold forming mold comprises an injection rod, an upper mold and a lower mold that cooperate with each other, the opening of the lower mold is upward, the opening of the upper mold is downward, at least three through holes are provided on the bottom wall of the lower mold, a lifting device is provided outside the lower mold, the execution end of the lifting device is connected to the injection rod, a first sealing ring coaxially provided at each through hole on the lower mold and cooperating with the injection rod, the top end of the injection rod passes through the through hole and extends into the lower mold, an injection hole is radially provided on the circumferential surface of the injection rod near the top end, the injection rod opens at one end outside the lower mold, and a switch door is provided on the injection rod at the injection hole.

[0006] Preferably, the upper end of the switch door is rotatably connected to the injection rod, and a torsion spring is provided at the rotatable connection.

[0007] Preferably, a melt cleaning mechanism is provided in the injection rod.

[0008] Preferably, the melt cleaning mechanism includes a plug body, an air channel, and an air pump. The air channel is arranged on the side wall of the injection rod, one end of the air channel opens at the open end of the injection rod, and the other end is on the inner top wall of the injection rod. The plug body is located inside the injection rod, and the circumferential surface of the plug body is tightly slidably connected to the inner side wall of the injection rod. The air outlet of the air pump is connected to the opening on the air channel located at the open end of the injection rod through a switching valve.

[0009] Preferably, the length of the plug body is greater than the distance from the upper edge of the injection hole to the opening of the injection rod.

[0010] Preferably, the lifting device includes a bracket, a hoop, and a cylinder, the lower mold is fixed on the bracket, the cylinder parallel to the injection rod is fixedly arranged on the bracket, the outer circumferential surface of the hoop is fixedly connected to the free end of the piston rod of the cylinder, the hoop is coaxially fixedly sleeved on the end of the injection rod located outside the lower mold, when the piston rod is fully retracted into the cylinder, the distance between the free end of the piston rod and the outer bottom wall of the lower mold is greater than the depth of the injection rod extending into the lower mold; when the piston rod is fully extended, the free end of the piston rod can hit the outer bottom wall of the lower mold.

[0011] Preferably, a second sealing ring cooperating with the switch door is provided at the injection hole.

[0012] A multi-material in-mold molding preparation method, comprising the above-mentioned multi-material in-mold molding mold, further comprising the following steps:

[0013] 1) First, adjust the length of the injection rod extending into the lower mold through the lifting device according to the required thickness of the unwrapped material, and open the switch door;

[0014] 2) placing the unwrapped material on the injection rod;

[0015] 3) Injecting liquid silicone into the mold through the opening of the injection rod, and stopping injecting liquid silicone into the mold after the liquid silicone in the mold reaches a preset amount;

[0016] 4) Close the injection hole with the switch door, then clean the liquid silicone in the injection rod, and finally heat the mold. After the liquid silicone in the mold solidifies, withdraw the injection rod to the outside of the lower mold through the lifting device, and then open the mold to take out the wrapped material.

[0017] Compared with the prior art, this application has the following beneficial effects:

[0018] 1. We designed a multi-material in-mold molding mold and a molding preparation method by inserting an injection rod for supporting the parts to be wrapped on the bottom wall of the lower mold, so that the parts to be wrapped will not sink in the mold due to their own gravity, resulting in a relatively thin silicone.

[0019] 2. In the present application, a torsion spring is provided at the rotational connection between the switch door and the injection rod, so that when the liquid silicone source sprays liquid silicone, the pressure will push the switch door open, thereby allowing the liquid silicone to enter the mold; and when the liquid silicone source stops, the switch door can automatically close under the action of its own gravity and the action of the torsion spring.

[0020] 3. The present application sets an air channel and a plug body in the injection rod so that when cleaning the injection rod, it is only necessary to switch the air pump to a positive pressure state so that there is a positive pressure between the plug body and the inner top wall of the injection rod, and the plug body will then drop to scrape clean the liquid silicone remaining in the injection rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure in this application;

[0022] Figure 2 This is a schematic diagram showing the structure inside the lower mold after removing the upper mold in this application;

[0023] Figure 3 It is a schematic diagram of the structure of the injection rod in this application;

[0024] Figure 4 is a cross-sectional view of the injection rod in this application;

[0025] Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0026] Among them, 1. injection body; 2. upper mold; 3. lower mold; 4. first sealing ring; 5. injection hole; 6. switch door; 7. plug body; 8. airway; 9. air pump; 10. switching valve; 11. bracket; 12. ferrule; 13. cylinder; 14. second sealing ring. DETAILED DESCRIPTION

[0027] like Figure 1-5As shown, a multi-material in-mold forming mold includes an injection rod 1, an upper mold 2 and a lower mold 3 that cooperate with each other, the opening of the lower mold 3 is upward, the opening of the upper mold 2 is downward, at least three through holes are provided on the bottom wall of the lower mold 3, a lifting device is provided outside the lower mold 3, the execution end of the lifting device is connected to the injection rod 1, and a first sealing ring 4 coaxially provided at each through hole on the lower mold 3 to cooperate with the injection rod 1, the top end of the injection rod 1 passes through the through hole and extends into the lower mold 3, an injection hole 5 is radially provided on the circumferential surface of the injection rod 1 near the top end, the injection rod 1 is opened at one end outside the lower mold 3, and a switch door 6 is provided on the injection rod 1 to cooperate with the injection hole 5.

[0028] In this embodiment, when in use, the end of the injection rod 1 located outside the lower mold 3 is connected to the outlet of the liquid silicone source. Then, the depth of the injection rod 1 inserted into the lower mold 3 is adjusted by the lifting device according to the thickness of the part to be wrapped. The depth greater than the depth of the injection rod 1 inserted into the lower mold 3 is equal to the thickness of the part to be wrapped. Then, the part is placed on the injection rod 1, and the injection rod 1 plays a supporting role. Preferably, the top of the injection rod 1 is flat, which is convenient for supporting the part (that is, the entire silver-plated bronze or ceramic part mentioned in the background technology). Then, liquid silicone is injected into the injection rod 1 through the liquid silicone source, so as to push the switch door 6 open, so that the liquid silicone enters the mold composed of the lower mold 3 and the upper mold 2 from the injection hole 5, until the liquid silicone overflows the upper surface of the part, and then the injection of liquid silicone into the injection rod 1 is stopped. At the same time, the switch door 6 is closed, and then the entire mold is heated. After the liquid silicone becomes fixed, the injection rod 1 is pulled out of the lower mold 3. At this time, the surface of the part is completely wrapped by silicone except for the part in contact with the top of the injection rod 1. Injecting liquid silicone from bottom to top in this way can make the liquid silicone completely contact the lower surface of the part. Compared with pouring liquid silicone from top to bottom, it can avoid the situation where the lower surface of the part is not covered by silicone due to bubbles and other reasons. The function of the first sealing ring 4 is to ensure that the airtightness of the mold composed of the lower mold 3 and the upper mold 2 will not be damaged during the expansion and contraction of the injection rod 1 on the lower mold 3. The switch door 6 is set so that after the liquid silicone is injected into the mold, the switch door 6 is closed so that the liquid silicone in the mold will not flow out of the mold through the injection rod 1.

[0029] As a preferred embodiment, the upper end of the switch door 6 is rotatably connected to the injection rod 1, and a torsion spring is provided at the rotatable connection. With this arrangement, when the liquid silicone source sprays liquid silicone, the pressure pushes the switch door 6 open, so that the liquid silicone enters the mold; and when the liquid silicone source stops, the switch door 6 can be automatically closed under the action of its own gravity and the torsion spring.

[0030] As a preferred embodiment, a melt cleaning mechanism is provided in the injection rod 1. By providing the cleaning mechanism, the liquid silicone is prevented from solidifying in the injection rod 1.

[0031] As a preferred mode, the melt cleaning mechanism comprises a plug body 7, an air channel 8, and an air pump 9. The air channel 8 is arranged on the side wall of the injection rod 1, one end of the air channel 8 opens at the open end of the injection rod 1, and the other end is at the inner top wall of the injection rod 1. The plug body 7 is located in the injection rod 1, and the circumferential surface of the plug body 7 is tightly slidably connected with the inner side wall of the injection rod 1. The air outlet of the air pump 9 is connected to the opening of the air channel 8 at the open end of the injection rod 1 through the switching valve 10. After such arrangement, in the process of injecting liquid silicone into the mold, the liquid silicone enters the injection rod 1 and first pushes the plug body 7 upward, so that the top of the plug body 7 presses against the inner top wall of the injection rod 1, and then the negative pressure state of the air pump 9 is started, so that the space between the plug body 7 and the inner top wall of the injection rod 1 becomes a vacuum state, thereby preventing the plug body 7 from blocking the injection hole 5. After the injection is completed, when cleaning the injection rod 1, it is only necessary to switch the air pump 9 to a positive pressure state so that there is a positive pressure between the plug body 7 and the inner top wall of the injection rod 1, and the plug body 7 will descend to scrape off the liquid silicone remaining in the injection rod 1.

[0032] As a preferred mode, the length of the plug body 7 is greater than the position from the upper edge of the injection hole 5 to the opening of the injection rod 1. With this arrangement, when the plug body 7 descends, the pressure applied by the air pump 9 between the plug body 7 and the inner top wall of the injection rod 1 will not be released at the injection hole 5, so that the pressure applied by the air pump 9 between the plug body 7 and the inner top wall of the injection rod 1 will not affect the closing of the switch door 6. When the lower end of the plug body 7 is exposed at the opening of the injection rod 1, the worker can handle it, and the work of the air pump 9 will be stopped at this time. Of course, the output port of the air pump 9 is connected to one end of the airway 8 located at the opening of the injection rod 1 (the lower end face of the injection rod 1) through the air pipe.

[0033] As a preferred mode, the lifting device includes a bracket 11, a hoop 12, and a cylinder 13. The lower mold 3 is fixedly arranged on the bracket 11. The cylinder 13 parallel to the injection rod 1 is fixedly arranged on the bracket 11. The outer circumferential surface of the hoop 12 is fixedly connected to the free end of the piston rod of the cylinder 13. The hoop 12 is coaxially fixedly sleeved on one end of the injection rod 1 located outside the lower mold 3. When the piston rod is fully retracted into the cylinder 13, the distance between the free end of the piston rod and the outer bottom wall of the lower mold 3 is greater than the depth of the injection rod 1 extending into the lower mold 3; when the piston rod is fully extended, the free end of the piston rod can reach the outer bottom wall of the lower mold 3. After such arrangement, the injection rod 1 is controlled to extend into or out of the lower mold 3 by the cylinder 13.

[0034] As a preferred embodiment, the injection hole 1 is provided with a second sealing ring 14 that cooperates with the switch door 6. The second sealing ring 14 is provided to prevent the switch door 6 from affecting the airtightness inside the mold.

[0035] 8. A method for preparing a multi-material in-mold molding, characterized in that it comprises the above-mentioned multi-material in-mold molding mold, and further comprises the following steps:

[0036] 1) First, the length of the injection rod 1 extending into the lower mold is adjusted by the lifting device according to the required thickness of the unwrapped material, and the switch door 6 is opened; so that the liquid silicone can be injected into the mold through the injection rod 1.

[0037] 2) Place the unwrapped material on the injection rod 1; support the part through the injection rod 1.

[0038] 3) Injecting liquid silicone into the mold through the opening of the injection rod 1, and stopping injecting liquid silicone into the mold after the liquid silicone in the mold reaches a preset amount;

[0039] 4) The switch door (6) is used to close the injection hole 5, and then the liquid silicone in the injection rod 1 is cleaned. Finally, the mold is heated. After the liquid silicone in the mold solidifies, the injection rod 1 is withdrawn to the outside of the lower mold through the lifting device, and then the mold is opened to take out the wrapped material.

Claims

1. A multi-material in-mold forming mold, characterized in that: The invention comprises an injection rod (1), an upper die (2) and a lower die (3) which cooperate with each other, the opening of the lower die (3) faces upward, the opening of the upper die (2) faces downward, at least three through holes are arranged on the bottom wall of the lower die (3), a lifting device is arranged outside the lower die (3), the execution end of the lifting device is connected to the injection rod (1), a first sealing ring (4) coaxially arranged at each through hole on the lower die (3) and cooperating with the injection rod (1), the top end of the injection rod (1) passes through the through hole and extends into the lower die (3), an injection hole (5) is radially arranged on the circumferential surface of the injection rod (1) near the top end, the injection rod (1) is opened at one end outside the lower die (3), and a switch door (6) is arranged on the injection rod (1) at the injection hole (5).

2. A multi-material in-mold forming mold according to claim 1, characterized in that: The upper end of the switch door (6) is rotatably connected to the injection rod (1), and a torsion spring is provided at the rotatable connection.

3. A multi-material in-mold forming mold according to claim 1, characterized in that: A melt cleaning mechanism is provided inside the injection rod (1).

4. A multi-material in-mold forming mold according to claim 3, characterized in that: The melt cleaning mechanism comprises a plug body (7), an air channel (8), and an air pump (9); the air channel (8) is arranged on the side wall of the injection rod (1); one end of the air channel (8) opens at the open end of the injection rod (1), and the other end is on the inner top wall of the injection rod (1); the plug body (7) is located inside the injection rod (1); the circumferential surface of the plug body (7) is tightly slidably connected to the inner side wall of the injection rod (1); the air outlet of the air pump (9) is connected to the opening of the air channel (8) located at the open end of the injection rod (1) through a switching valve (10).

5. A multi-material in-mold forming mold according to claim 4, characterized in that: The length of the plug body (7) is greater than the distance from the upper edge of the injection hole (5) to the opening of the injection rod (1).

6. A multi-material in-mold forming mold according to claim 4, characterized in that: The lifting device comprises a bracket (11), a hoop (12), and a cylinder (13); the lower mold (3) is fixedly arranged on the bracket (11); the cylinder (13) is fixedly arranged on the bracket (11) and is parallel to the injection rod (1); the outer circumferential surface of the hoop (12) is fixedly connected to the free end of the piston rod of the cylinder (13); the hoop (12) is coaxially fixedly sleeved on one end of the injection rod (1) located outside the lower mold (3); when the piston rod is fully retracted into the cylinder (13), the distance between the free end of the piston rod and the outer bottom wall of the lower mold (3) is greater than the depth of the injection rod (1) extending into the lower mold (3); when the piston rod is fully extended, the free end of the piston rod can reach the outer bottom wall of the lower mold (3).

7. The multi-material in-mold forming mold according to claim 1, characterized in that: The injection hole (1) is provided with a second sealing ring (14) which cooperates with the switch door (6).

8. A multi-material in-mold molding preparation method, characterized in that: The multi-material in-mold forming mold according to claim 1 further comprises the following steps: 1) First, adjust the length of the injection rod extending into the lower mold through the lifting device according to the required thickness of the unwrapped material, and open the switch door; 2) placing the unwrapped material on the injection rod; 3) Injecting liquid silicone into the mold through the opening of the injection rod, and stopping injecting liquid silicone into the mold after the liquid silicone in the mold reaches a preset amount; 4) The switch door (6) is closed to close the injection hole, and then the liquid silicone in the injection rod is cleaned. Finally, the mold is heated. After the liquid silicone in the mold solidifies, the injection rod is withdrawn to the outside of the lower mold through the lifting device, and then the mold is opened to take out the wrapped material.

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