A rotational molding processing mold

Abstract

The present application relates to rotational moulding processing technical field, specifically to a kind of rotational moulding processing mould, including mould, support, power unit, transfer unit, heating unit, cooling unit, power supply unit and control unit;The mould is cuboid structure;The support is inverted L type structure;And the support is made of multiple different sizes steel frame;Power unit is rotatably installed above the support;Heating unit and cooling unit are fixedly installed on the same side below the support respectively;Transfer unit is movably installed below power unit;Power supply unit is fixedly installed above transfer unit;The mould includes mould box and mould cover;Mould box is rotatably installed in the bottom of transfer unit on both sides;Power unit, transfer unit, heating unit, cooling unit and power supply unit are electrically connected with control unit respectively, the present application not only can realize the effective use of excess heat, shorten the time of rotational moulding heating and cooling simultaneously, improve production efficiency.

Description

Technical Field

[0001] This invention relates to the field of rotational molding technology, and more specifically to a rotational molding mold. Background Technology

[0002] In the rotational molding process, molds are used to shape the product. During the molding process, the mold needs to be heated and cooled. If the heating time of the mold is insufficient or uneven, or if the cooling time is too short or uneven, it will affect the product, resulting in reduced product quality, lower production efficiency, and higher scrap rate. The molds used in the current rotational molding process have certain drawbacks. During long-term production, the heat dissipation capacity of the mold itself is insufficient to achieve good heat dissipation, and external water tower cooling is not convenient and costly.

[0003] In the rotational molding process, heating is a crucial step. The heating method and the temperature of the mold are important factors affecting the rotational molding process. Therefore, there are various heating methods for rotational molding, each with different heating effects. Based on different heating devices, existing technology discloses a rotational molding heating device. For example, Chinese Invention Patent CN104354255A (publication date: 2015-02-18) discloses a rotational molding oven and rotational molding mold heating device, including a shell, a burner, and a gas cylinder. The shell has a vortex chamber, an air inlet channel, and an air outlet channel; the vortex chamber is equipped with... The fan impeller has its shaft extending out of the housing. The burner and gas cylinder are both fixed to the housing, with the gas cylinder located inside the air inlet channel. The burner's nozzle is connected to one end of the gas cylinder, while the other end of the gas cylinder faces the vortex chamber. Several parallel guide plates are installed at the air outlet of the air outlet channel, and the guide plates are hinged to the housing. This allows the mold temperature to be raised through the rotational molding oven, resulting in uniform heating. However, this heating device requires a certain amount of time to raise the temperature each time the mold is heated. Using fuel heating results in excess heat not being effectively utilized, and a certain amount of fuel needs to be burned each time the mold is heated.

[0004] Regarding the aforementioned gas cylinder heating method, existing technology also discloses another rotational molding heating device, such as Chinese invention patent CN103264473B (publication date: 2015-04-22), which discloses a portable, temperature-precisely controllable all-plastic storage tank rotational molding device, including a shell, insulation layer, electric heating network, heat-conducting layer, mold body, etc. It uses an electric heating network for heating, with the outer layer of the electric heating network covered with insulation material, and the outer layer of the mold covered with a high thermal conductivity material. The electric heating network is divided into six modules along the circumference of the mold, using an independent power supply method, with the power supply sequence and current controlled by the power distribution system. The insulation layer outside the electric heating network is processed with serpentine channels. This device has the advantages of precise temperature control, uniform temperature, and convenient mobility, and also has the characteristics of energy saving and cleanliness. However, this device also requires a certain preheating time during heating, which increases the rotational molding heating time and reduces the efficiency of rotational molding.

[0005] In rotational molding production, each product needs to be manufactured in large quantities. This places higher demands on the rotational molding equipment, requiring both high quality and efficient production. Therefore, existing technologies offer several solutions for rotational molding. For example, Chinese invention patent CN106827338B (publication date: 2018-12-11) discloses a comprehensive and efficient rotational molding platform, including a support frame, a control console, and a rotating system, heating system, cooling system, and mold connected to the console. The rotating system includes several rotating devices of different sizes. The rotating devices are sequentially fixed to each other in a ring-like arrangement according to their relative size, and each rotating device can rotate 360 ​​degrees. The rotating system is rotatably fixed to the support frame. The mold is rotatably fixed inside the rotating system. The heating system is fixed to the mold. The cooling system is fixed to the rotating device closest to the mold. This breaks the original situation where the mold of the rotational molding machine can only rotate in one direction, improves the rotational molding efficiency of the rotational molding platform and the quality of the products. Direct heating makes the rotational molding process easy to control. However, the device requires a certain heating time, can only heat a single rotational molding mold, and needs to be reheated each time, resulting in low production efficiency.

[0006] In view of this, and in response to the above-mentioned shortcomings, the present invention has improved and optimized existing rotational molding dies to develop a rotational molding die. Summary of the Invention

[0007] The technical problem to be solved by the present invention is as follows: The present invention provides a rotational molding die, which not only enables the effective utilization of excess heat, but also improves the utilization rate of fuel, saves energy consumption, shortens the heating and cooling time of rotational molding, and improves production efficiency.

[0008] This invention provides the following technical solution: a rotational molding die, comprising a die, a support, a power unit, a transfer unit, a heating unit, a cooling unit, a power supply unit, and a control unit; the die is a cuboid structure; the support is an inverted L-shaped structure; and the support is composed of multiple steel frames of different sizes; a power unit is rotatably mounted on top of the support; the power unit is used to drive the die to move; a heating unit and a cooling unit are fixedly mounted on the same side below the support; the heating unit and cooling unit are used for heating and cooling the die, respectively; a transfer unit is movably mounted below the power unit; the transfer unit is used to control the rotation of the die; a power supply unit is fixedly mounted above the transfer unit; the power supply unit is used to provide power to the transfer unit; the die includes a die box and a die cover; the die box is rotatably mounted on both sides at the bottom of the transfer unit; the die cover and the die box are sealed and fixedly connected by bolts; the power unit, transfer unit, heating unit, cooling unit, and power supply unit are electrically connected to the control unit; the control unit is used to control the rotation speed of the power unit, and simultaneously control the operation of the air pump, rotating motor, electric telescopic rod, and high-temperature resistant motor within the transfer unit.

[0009] Preferably, a permanent magnet is fixedly installed on the top of the mold cover; and the permanent magnet has a conical frustum structure; the permanent magnet is fixedly installed on the mold cover for mutual attraction with the electromagnet. The mold cover is opened by an electric telescopic rod. The permanent magnet is a neodymium iron boron magnet. The conical frustum structure of the permanent magnet is to better ensure mutual attraction between the permanent magnet and the electromagnet, and can also achieve automatic centering.

[0010] Preferably, grooves are respectively formed at the center of both sides of the mold box, and the two grooves are connected to the vent holes inside the mold box; the vent holes are arranged according to the product model to be processed; ball bearings are fixedly installed in the two grooves, and the ball bearings are fixedly installed in the grooves for the rotation of the mold.

[0011] Preferably, the power unit includes a cable, a rotating wheel, and a direct-drive motor; multiple rotating wheels are vertically rotatably mounted on the tops of multiple supports; the supports are used to support the movement of the transfer unit and the mold; the cable is rotatably mounted on the rotating wheel of the direct-drive motor; and the cable is simultaneously rotatably mounted on other multiple rotating wheels; the rotation of the direct-drive motor drives the cable to rotate on the direct-drive motor; the cable is connected end to end; the connection of the cable ends is to enable the entire system to operate in a cyclical manner.

[0012] Preferably, the transfer unit includes a rotating frame, an electric telescopic rod, an electromagnet, a rotary motor, a high-temperature resistant motor, and an air pump; the top of the rotating frame is fixedly mounted on a cable; an air pump is fixedly mounted below the top of the rotating frame; the air pump is used to pressurize the inside of the mold during demolding; the middle part of the rotating frame has an arc-shaped structure; the arc-shaped structure in the middle is to keep the center of gravity of the rotating frame and the mold directly below the cable; a rotary motor is fixedly mounted below the arc-shaped structure in the middle of the rotating frame; the rotary motor is used to control the rotation of the bottom of the rotating frame and the mold on the bottom; the bottom of the rotating frame has a U-shaped structure; an electric telescopic rod is fixedly mounted at the center position above the U-shaped structure at the bottom of the rotating frame; an electromagnet is fixedly mounted at the top of the electric telescopic rod; the electromagnet has a conical groove structure; the electric telescopic rod is used to control the opening and closing of the mold cover; A high-temperature resistant motor is fixedly installed inside one end of the U-shaped structure at the bottom of the rotating frame; both ends of the U-shaped structure at the bottom of the rotating frame are respectively sealed and rotatably mounted on both sides of the mold; the high-temperature resistant motor is used to drive the mold to rotate; a heat insulation layer is fixedly installed on the inner wall of the bottom of the rotating frame; the heat insulation layer is fixedly installed on the inner wall of the bottom of the rotating frame to prevent damage to other internal mechanisms or air pipes under high temperature; an air pipe is fixedly installed inside from the bottom end of the rotating frame to the top end of the arc-shaped structure; one end of the air pipe inside the bottom end of the rotating frame is connected to the grooves on both sides of the mold box; the other end of the air pipe inside the top end of the arc-shaped structure of the rotating frame is connected to an air pump; the air pipe is used for venting the mold and pressurizing the mold during demolding; a signal receiving device is fixedly installed inside the arc-shaped structure in the middle of the rotating frame, and the signal receiving device is used to receive signals sent by the control unit.

[0013] Preferably, the heating unit includes an oil tank and heat transfer oil; the oil tank contains heat transfer oil; the heat transfer oil is hydrogenated terphenyl; the temperature of the heat transfer oil is maintained at approximately 220°C; an insulation layer is fixedly installed on the outer surface of the oil tank; the insulation layer is used to maintain the temperature of the heat transfer oil in the oil tank, and maintaining the temperature of the heat transfer oil in the oil tank at 220°C is to enable rapid heating of the mold.

[0014] Preferably, the cooling unit includes a water tank and coolant; the water tank contains coolant; a level gauge is fixedly installed inside the water tank; the level gauge is used to detect the level of the coolant in the water tank.

[0015] Preferably, the power supply unit includes a contact wire and a pantograph; the contact wire is fixedly installed above the bracket; and the contact wire is located directly above the cable; the pantograph is fixedly installed on the top of the rotating frame of the transfer unit; the pantograph is located below the contact wire, and the two slide in contact with each other; the power supply unit is used to supply power to the air pump, electric telescopic rod, rotating motor and high-temperature resistant motor on the rotating frame unit.

[0016] Preferably, multiple temperature sensors are fixedly installed on the bracket, and the multiple temperature sensors are electrically connected to the control unit; the temperature sensors are used to detect the temperature of the heat transfer oil and coolant, and can also detect the temperature of the outer surface of the mold after cooling; multiple preset values ​​are set in the control unit; when the temperature sensor detects the temperature, it sends a signal to the control unit in real time.

[0017] Preferably, a sealing gasket is fixedly installed between the mold cover and the mold box; an oil-proof coating is applied to the outer surface of the bottom of the rotating frame; the sealing gasket fixedly installed between the mold cover and the mold box is used to prevent heat transfer oil from entering the mold; the oil-proof coating is applied to the outer surface of the bottom of the rotating frame to prevent the mold from carrying oil on its outer surface when it comes out of the heat transfer oil.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. This invention features a power unit rotatably mounted above a support frame, and a heating unit and a cooling unit fixedly mounted on the same side below the support frame. A transfer unit is movably mounted below the power unit, and mold boxes are rotatably mounted on both sides of the transfer unit at its bottom. A power supply unit is fixedly mounted above the transfer unit. This allows multiple molds to be heated and cooled by the power unit and transfer unit, respectively, through the heating and cooling units. Simultaneously, during the heating and cooling process, the transfer unit rotates the molds, ensuring uniform heating and allowing the molten plastic to adhere evenly to the inner wall of the mold. This improves production efficiency and quality, effectively utilizes heat, and reduces energy consumption.

[0020] 2. This invention achieves automatic opening of the mold cover by fixing a permanent magnet to the top of the mold cover, an electric telescopic rod to the bottom of the rotating frame, and an electromagnet to the top of the electric telescopic rod. The mutual attraction between the permanent magnet and the electromagnet, along with the air pump fixedly installed below the top of the rotating frame and an air pipe fixedly installed inside the rotating frame from the bottom to the top of the arc-shaped structure, prevents burns to operators caused by insufficient cooling or residual cooling heat. The air pipe allows for effective venting of the mold during rotational molding, preventing air bubbles. Simultaneously, the air pump can be used to pressurize the mold through the vent during demolding, making demolding more efficient.

[0021] 3. This invention enables real-time detection of the heating unit temperature during heating by fixing multiple temperature sensors on the bracket, preventing situations such as excessively low or high heating temperatures. It can also detect the temperature of the mold after cooling, preventing operators from being burned. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0024] Figure 2 This is the front view of the present invention.

[0025] Figure 3 This is a top view of the present invention.

[0026] Figure 4 This is a side view of the present invention.

[0027] Figure 5 This is a three-dimensional structural diagram of the mold of the present invention.

[0028] Figure 6 This is a front view of the mold of the present invention.

[0029] Figure 7 This is a partial cross-sectional view of the rotating frame and mold of the present invention.

[0030] Figure 8 This is a three-dimensional structural diagram of the pantograph, rotating frame, and mold of the present invention.

[0031] Figure 9 This is a three-dimensional structural diagram of the bracket and the rotating wheel of the present invention.

[0032] Figure 10 This is a three-dimensional structural diagram of the direct drive motor and rotor of the present invention.

[0033] In the diagram: Mold 1, Mold box 11, Mold cover 12, Bolt 13, Permanent magnet 14, Ball bearing 15, Groove 16, Bracket 2, Power unit 3, Rope 31, Rotary wheel 32, Direct drive motor 33, Transfer unit 4, Rotating frame 41, Electric telescopic rod 42, Electromagnet 43, Rotating motor 44, High temperature resistant motor 45, Air pump 46, Heating unit 5, Oil tank 51, Cooling unit 6, Water tank 61, Power supply unit 7, Contact line 71, Pantograph 72. Detailed Implementation

[0034] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0035] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 6 and Figure 7 As shown, a rotational molding die includes a die 1, a support 2, a power unit 3, a transfer unit 4, a heating unit 5, a cooling unit 6, a power supply unit 7, and a control unit. The die 1 has a rectangular parallelepiped structure. The support 2 has an inverted L-shaped structure and is composed of multiple steel frames of different sizes. The power unit 3 is rotatably mounted on top of the support 2 and is used to move the die 1. The heating unit 5 and cooling unit 6 are fixedly mounted on the same side below the support 2 and are used for heating and cooling the die 1, respectively. The transfer unit 4 is movably mounted below the power unit 3 and is used to control the rotation of the die 1. The power supply unit 7 is fixedly mounted on top of the transfer unit 4 and provides power to the transfer unit 4. The die 1 includes a die box 11 and a die cover 12. The die box 11 is rotatably mounted on both sides at the bottom of the transfer unit 4. The cover 12 and the mold box 11 are sealed and fixedly connected by bolts 13; the power unit 3, the transfer unit 4, the heating unit 5, the cooling unit 6 and the power supply unit 7 are electrically connected to the control unit; the control unit is used to control the rotation speed of the power unit 3, thereby controlling the movement speed of the mold 1 on the transfer unit 4, so that the mold 1 is fully heated in the heat transfer oil of the heating unit 5, and also fully cooled in the coolant of the cooling unit 6; and the control unit controls the operation of the air pump 46, the rotating motor 44, the electric telescopic rod 42 and the high temperature resistant motor 45 in the transfer unit 4, by controlling the air pressure of the air pump 46 to inflate the mold 1, so that the mold 1 can be demolded better, by controlling the rotation speed of the rotating motor 44 and the rotation speed of the high temperature resistant motor 45, so that the plastic melt inside the mold 1 can be evenly attached to the inner wall of the mold 1, and by controlling the electric telescopic rod 42, the opening and closing of the mold cover 12 is controlled.

[0036] like Figures 5 to 7 As shown, a permanent magnet 14 is fixedly installed on the top of the mold cover 12; and the permanent magnet 14 has a conical frustum structure; the permanent magnet 14 is fixedly installed on the mold cover 12 for mutual attraction with the electromagnet 43. The mold cover 12 is opened by an electric telescopic rod 42. The permanent magnet 14 is a neodymium iron boron magnet because neodymium iron boron magnets will not demagnetize within 300℃, ensuring mutual attraction between the permanent magnet 14 and the electromagnet 43. The conical frustum structure of the permanent magnet 14 is to better ensure mutual attraction between the permanent magnet 14 and the electromagnet 43, and can also achieve automatic centering.

[0037] like Figure 7As shown, grooves 16 are respectively provided at the center of both sides of the mold box 11, and the two grooves 16 are connected to the venting holes inside the mold box 11; the venting holes are arranged according to the product model to be processed; ball bearings 15 are fixedly installed in the two grooves 16, and the ball bearings 15 are fixedly installed in the grooves 16 for the rotation of the mold 1. Because the rotation of the mold 1 should not affect the venting and inflation demolding effect of the mold 1, the hollow part of the outer side of the ball bearing 15 is connected to the air pipe to avoid the rotation of the mold 1 from affecting the air pipe.

[0038] like Figure 1 , Figure 2 , Figure 3 and Figure 10 As shown, the power unit 3 includes a cable 31, a rotating wheel 32, and a direct drive motor 33; multiple rotating wheels 32 are vertically rotatably mounted on the tops of multiple brackets 2; the brackets 2 are used to support the movement of the transfer unit 4 and the mold 1; the cable 31 is rotatably mounted on the rotating wheel 32 of the direct drive motor 33; and the cable 31 is simultaneously rotatably mounted on other multiple rotating wheels 32; the rotation of the direct drive motor 33 drives the cable 31 to rotate on the direct drive motor 33, and through the rotation of the cable 31, the cable 31 drives the transfer unit 4 to move, and the cable 31 is connected end to end; the connection of the cable 31 end to end is to enable the entire system to operate in a cyclical manner, thereby improving the efficiency of rotational molding.

[0039] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 7 and Figure 8As shown, the transfer unit 4 includes a rotating frame 41, an electric telescopic rod 42, an electromagnet 43, a rotary motor 44, a high-temperature resistant motor 45, and an air pump 46. The top of the rotating frame 41 is fixedly mounted on the cable 31. The air pump 46 is fixedly mounted below the top of the rotating frame 41. The air pump 46 is used to pressurize the inside of the mold 1 when the mold 1 is demolded, so that the mold 1 can be demolded quickly. The middle part of the rotating frame 41 has an arc-shaped structure. The arc-shaped structure in the middle is to keep the center of gravity of the rotating frame 41 and the mold 1 directly below the cable 31, preventing the entire device from tilting due to the shift of the center of gravity. The rotary motor 44 is fixedly mounted below the arc-shaped structure in the middle of the rotating frame 41. The rotating motor 44 controls the rotation of the bottom of the rotating frame 41 and the mold 1 on the bottom. The bottom of the rotating frame 41 has a U-shaped structure. An electric telescopic rod 42 is fixedly installed at the center of the upper part of the U-shaped structure at the bottom of the rotating frame 41. An electromagnet 43 is fixedly installed at the top of the electric telescopic rod 42. The electromagnet 43 has a conical groove structure. The electric telescopic rod 42 controls the opening and closing of the mold cover 12. When the electromagnet 43 is energized, it attracts the permanent magnet 14 on the mold cover 12, thus opening the mold cover 12. The conical groove structure of the electromagnet 43 is for better connection and attraction with the permanent magnet 14, and also enables automatic centering.

[0040] A high-temperature resistant motor 45 is fixedly installed inside one end of the U-shaped structure at the bottom of the rotating frame 41; the two ends of the U-shaped structure at the bottom of the rotating frame 41 are respectively sealed and rotatably mounted on both sides of the mold 1; the high-temperature resistant motor 45 is used to drive the mold 1 to rotate. Because the mold 1 is in the heat transfer oil, the surrounding temperature rise may have a certain impact on the motor, so a high-temperature resistant motor 45 is required. A heat insulation layer is fixedly installed on the inner wall at the bottom of the rotating frame 41; the heat insulation layer is fixedly installed on the inner wall at the bottom of the rotating frame 41 to prevent damage to other internal mechanisms or air pipes under high temperature, which could lead to substandard quality of the rotational molding product. An air pipe is fixedly installed inside the bottom end of the rotating frame 41 and the top end of the arc-shaped structure; one end of the air pipe inside the bottom end of the rotating frame 41 is connected to the grooves on both sides of the mold box 11; the other end of the air pipe inside the top end of the arc-shaped structure of the rotating frame 41 is connected to the air pump 46; the air pipe is used for venting the mold 1 and pressurizing the mold 1 during demolding, so that the mold 1 can be demolded quickly; a signal receiving device is fixedly installed inside the arc-shaped structure in the middle of the rotating frame 41; the signal receiving device is used to receive the signal sent by the control unit, and control the operation of the air pump 46, the rotating motor 44, the electric telescopic rod 42 and the high-temperature resistant motor 45 inside the rotating frame 41 through the signal sent by the control unit.

[0041] like Figures 1 to 3As shown, the heating unit 5 includes an oil tank 51 and heat transfer oil; the oil tank 51 is filled with heat transfer oil; the heat transfer oil is hydrogenated terphenyl; the temperature of the heat transfer oil is maintained at about 220°C; an insulation layer is fixedly installed on the outer surface of the oil tank 51; the insulation layer is used to maintain the temperature of the heat transfer oil in the oil tank 51. Maintaining the temperature of the heat transfer oil in the oil tank 51 at 220°C is to enable rapid heating of the mold 1, and also to ensure that the mold 1 is heated evenly, reducing the preheating step. The heat transfer oil uses hydrogenated terphenyl because it has a boiling point as high as 352°C, and has advantages such as good thermal conductivity, good high-temperature stability, low permeability, and non-toxicity.

[0042] like Figures 1 to 3 As shown, the cooling unit 6 includes a water tank 61 and coolant; the water tank 61 is filled with coolant; a liquid level gauge is fixedly installed inside the water tank 61; the liquid level gauge is used to detect the liquid level in the water tank 61. During long-term operation, the mold 1 will carry some coolant out of the water tank 61, causing the liquid level to drop. If the coolant is not replenished in time, the mold 1 cannot be completely immersed in the coolant, which will result in poor cooling effect.

[0043] like Figure 1 , Figure 2 , Figure 4 and Figure 8 As shown, the power supply unit 7 includes a contact wire 71 and a contact wire 72; the contact wire 71 is fixedly installed above the bracket 2; and the contact wire 71 is located directly above the cable 31; the contact wire 72 is fixedly installed on the top of the rotating frame 41 of the transfer unit 4; the power receiver is located below the contact wire 71, and the two slide in contact with each other; the power supply unit 7 is used to supply power to the air pump 46, electric telescopic rod 42, rotating motor 44 and high temperature resistant motor 45 on the rotating frame 41 unit to maintain the normal operation of the mold 1; the contact wire 71 is fixedly installed from the loading position of the mold 1 to the unloading position of the mold 1. When the unloading position of the mold 1 returns to its original position, the contact wire 72 does not contact the contact wire 71, and the entire rotating frame 41 will not have any power, which saves both electricity and materials.

[0044] Multiple temperature sensors are fixedly installed on the bracket 2, and these sensors are electrically connected to the control unit. The temperature sensors detect the temperature of the heat transfer oil and coolant, and also the temperature of the outer surface of the mold 1 after cooling. The control unit has multiple preset values. When a temperature sensor detects a temperature, it sends a signal to the control unit in real time. When the temperature sensor detects that the temperature of the heat transfer oil is lower than the preset value set in the control unit, the control unit controls the heating device to heat the heat transfer oil. When the temperature sensor detects that the temperature of the heat transfer oil exceeds the preset value set in the control unit, the control unit controls the heating device to stop heating. When the temperature sensor detects that the temperature of the coolant in the water tank 61 exceeds the preset value set in the control unit, the control unit controls the cooling device to cool the coolant in the water tank 61. After the mold 1 has cooled, the temperature sensor detects the temperature of the outer surface of the mold 1, and sends the detected signal to the control unit. When the temperature is too high, an alarm is issued through the control unit to prevent operators from being burned when opening the mold 1.

[0045] A sealing gasket is fixedly installed between the mold cover 12 and the mold box 11; an oil-proof coating is applied to the bottom outer surface of the rotating frame 41; the sealing gasket is fixedly installed between the mold cover 12 and the mold box 11 to prevent heat transfer oil from entering the mold 1, causing damage to the rotational molding product, and also to prevent leakage of molten plastic inside the mold 1; the oil-proof coating is applied to the bottom outer surface of the rotating frame 41 to prevent the mold 1 from carrying oil on its outer surface when it comes out of the heat transfer oil, which would cause waste of heat transfer oil under long-term working conditions, and also cause a large amount of heat transfer oil to be mixed in the coolant, resulting in a decrease in cooling effect.

[0046] During operation, the switch button is turned on, and controlled by the control unit, the force-bearing bow and contact wire 71 come into contact, providing power to the rotating frame 41. The electric push rod under the rotating frame 41 extends, and the electromagnet 43 at the top of the electric push rod is energized and attracts the permanent magnet 14 above the mold cover 12. The electric telescopic rod 42 retracts, causing the mold cover 12 to rise and open. The operator pours plastic material into the mold box 11 and presses the control button. The electric push rod extends, causing the mold cover 12 to fall. When the mold cover 12 contacts the mold box 11, the electromagnet 43 is de-energized, and the electric telescopic rod 42 causes the electromagnet 43 to retract. The operator uses an electric gun to drive the bolts 13 on the mold cover 12 into the mold box 11, sealing and fixing the mold box 11 and the mold cover 12. At this time, the control unit controls the direct drive motor 33 to rotate, driving... The cable 31 rotates on the wheel 32 on the support 2, and the cable 31 drives the rotating frame 41 to move. The rotating motor 44 and the high-temperature motor 45 on the rotating frame 41 rotate simultaneously, driving the mold 1 to rotate axially and radially at the same time. The cable 31 drives the mold 1 to one end of the heating oil tank 51. As the direct drive motor 33 slowly rotates, the mold 1 slowly moves to the other end of the oil tank 51 and also moves downwards until the mold 1 is completely immersed in the heat transfer oil. The mold 1 moves slowly in the heat transfer oil. At the same time, the temperature sensor detects the temperature of the heat transfer oil in real time to prevent the temperature of the heat transfer oil from being too high or too low. When the temperature is too low, the temperature sensor will send a signal to the control unit. The control unit controls the heating device to heat the heat transfer oil in the oil tank 51. At the same time, the mold box 11 discharges gas from the gas pipe through the exhaust port.

[0047] As mold 1 slowly moves to the other end of oil tank 51, heating is completed. Direct drive motor 33 slowly rotates, driving cable 31 to rotate. Cable 31 drives mold 1 to slowly rise from the heat transfer oil. When mold 1 reaches its highest position, it begins to move slowly horizontally. Upon reaching cooling unit 6, it slowly enters the coolant in water tank 61. Mold 1 moves slowly in coolant, while temperature sensor monitors the coolant temperature in real time. If the temperature is too high, it sends a signal to control unit to adjust the coolant temperature. When cooling is complete, mold 1 slowly rises from the coolant. At this time, temperature sensor detects the surface temperature of mold 1. When the temperature is within the specified range, rotating motor 44 and high-temperature motor 45 on rotating frame 41 stop rotating simultaneously in the specified direction. Mold 1 stops rotating, electric telescopic rod 42 extends, electromagnet 43 is energized, and electromagnet 43 is connected to the permanent magnet on mold cover 12. Magnets 14 attract each other. At this time, the operator uses an electric gun to loosen the bolts 13 on the mold cover 12, presses the control button, the electric telescopic rod 42 retracts, driving the mold cover 12 to rise, the mold cover 12 separates from the mold box 11, the high-temperature motor 45 rotates 180°, the mold box 11 opens downwards, the air pump 46 starts, and air is injected into the mold box 11 through the air pipe. The mold 1 is demolded faster by its own weight and air pressure. After demolding, the high-temperature motor 45 returns to its original position, and the mold 1 moves slowly until the mold 1 returns to the feeding position by the rope 31. During the process of returning to the original position, the contact wire 72 separates from the contact wire 71 and no longer provides power to the transfer unit 4. When it returns to the feeding position, the contact wire 72 contacts the contact wire 71 and provides power to the transfer unit 4. During this process, the heating unit 5 and the cooling unit 6 heat and cool multiple molds 1 respectively, and repeat the cycle.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rotational molding die, comprising a die, a support, a power unit, a transfer unit, a heating unit, a cooling unit, a power supply unit, and a control unit; characterized in that: The mold has a rectangular structure; the support has an inverted L-shaped structure and is composed of multiple steel frames of different sizes; a power unit is rotatably mounted on top of the support, which drives the mold to move; a heating unit and a cooling unit are fixedly mounted on the same side below the support, which are used for heating and cooling the mold, respectively; a transfer unit is movably mounted below the power unit, which controls the rotation of the mold; a power supply unit is fixedly mounted above the transfer unit, which provides power to the transfer unit; the mold includes a mold box and a mold cover; the mold box is rotatably mounted on both sides at the bottom of the transfer unit; the mold cover and the mold box are sealed and fixedly connected by bolts; the power unit, transfer unit, heating unit, cooling unit, and power supply unit are all electrically connected to the control unit. A permanent magnet is fixedly installed on the top of the mold cover; and the permanent magnet has a conical frustum structure. The mold box has grooves at the center of each side, and the two grooves are connected to the vents inside the mold box; the vents are arranged according to the product model to be processed; ball bearings are fixedly installed in the two grooves. The power unit includes a cable, a reel, and a direct drive motor; multiple reels are vertically rotatably mounted on the top of multiple brackets; the cable is rotatably mounted on the reel of the direct drive motor; and the cable is simultaneously rotatably mounted on multiple other reels. The ropes are connected end to end; The transfer unit includes a rotating frame, an electric telescopic rod, an electromagnet, a rotary motor, a high-temperature resistant motor, and an air pump. The top of the rotating frame is fixedly installed on a cable. An air pump is fixedly installed below the top of the rotating frame. The middle of the rotating frame has an arc-shaped structure. A rotary motor is fixedly installed below the arc-shaped structure in the middle of the rotating frame. The bottom of the rotating frame has a U-shaped structure. An electric telescopic rod is fixedly installed at the center of the top of the U-shaped structure at the bottom of the rotating frame. An electromagnet is fixedly installed at the top of the electric telescopic rod. The electromagnet has a conical groove structure. A high-temperature resistant motor is fixedly installed inside one end of the U-shaped structure at the bottom of the rotating frame; both ends of the U-shaped structure at the bottom of the rotating frame are sealed and rotatably mounted on both sides of the mold; a heat insulation layer is fixedly installed on the inner wall of the bottom of the rotating frame; an air pipe is fixedly installed inside from the bottom of the rotating frame to the top of the arc-shaped structure; one end of the air pipe inside the bottom of the rotating frame is connected to the grooves on both sides of the mold box; the other end of the air pipe inside the top of the arc-shaped structure of the rotating frame is connected to an air pump; a signal receiving device is fixedly installed inside the arc-shaped structure in the middle of the rotating frame. The power supply unit includes a contact wire and a pantograph; the contact wire is fixedly installed above the bracket and is located directly above the cable; the pantograph is fixedly installed on the top of the transfer unit's rotating frame and is located below the contact wire, with the two sliding in contact with each other.

2. The rotational molding die according to claim 1, characterized in that: The heating unit includes an oil tank and heat transfer oil; the oil tank contains heat transfer oil; the heat transfer oil is hydrogenated terphenyl; the temperature of the heat transfer oil is maintained at 220℃.

3. The rotational molding die according to claim 2, characterized in that: The cooling unit includes a water tank and coolant; the water tank contains coolant.

4. The rotational molding die according to claim 1, characterized in that: Multiple temperature sensors are fixedly mounted on the bracket, and these temperature sensors are electrically connected to the control unit.

5. A rotational molding die according to claim 4, characterized in that: A sealing gasket is fixedly installed between the mold cover and the mold box; the outer surface of the bottom of the rotating frame is coated with an oil-proof coating.

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