Electric injection molding machine with hydraulic pressure cylinder high-pressure mold locking

Abstract

The utility model belongs to the field of injection molding machines, and relates to an electric injection molding machine with a hydraulic pressurizing cylinder high-pressure mold locking, which comprises an injection molding device, a mold, a mold closing device and a pressurizing device, the pressurizing device comprises a mold opening and closing oil cylinder, a piston rod is arranged in an oil cavity and divides the oil cavity into a liquid inlet cavity and a liquid outlet cavity, the electric injection molding machine further comprises a pressurizing cylinder, and the pressurizing cavity is divided into an oil return cavity and a pressurizing cavity. The oil return cavity is communicated with a liquid outlet cavity of the mold opening and closing oil cylinder, the pressurizing cavity is communicated with a liquid inlet cavity of the mold opening and closing oil cylinder, a pressurizing push rod is arranged in the pressurizing cavity, a circulation section is arranged at the front end of the pressurizing push rod, an oil groove is formed in the circulation section, the oil groove is opened towards the front end and communicated with the pressurizing cavity, and a plurality of circulation through holes are formed in the peripheral side of the rear end of the circulation section. The pressure maintaining device has the advantages that the pressure maintaining is realized through the pressure cylinder, the occupied volume can be reduced, and the mold clamping force can be ensured.

Description

Technical Field

[0001] This utility model belongs to the field of injection molding machines and relates to an electric injection molding machine with a hydraulic booster cylinder for high-pressure mold locking. Background Technology

[0002] Traditional injection molding machines typically consist of an injection system, a mold, a clamping system, and a hydraulic transmission system. The hydraulic system mainly relies on hydraulic cylinders, whose primary function is to maintain pressure during injection, ensuring sufficient clamping force during mold closing. However, hydraulic systems occupy a large area and are expensive. If a hydraulic system is not used for pressure maintenance and only an electric motor is used, the motor cannot withstand such a large clamping force and is easily worn out and damaged. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides an electric injection molding machine with a hydraulic booster cylinder for high-pressure clamping. This device has the advantages of achieving pressure holding through the booster cylinder, which reduces the occupied volume while ensuring clamping force.

[0004] The objective of this invention is achieved as follows:

[0005] An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking includes an injection unit, a mold, a mold closing unit, and a booster unit. The mold is provided with an upper mold fixing plate, an upper mold, a lower mold, a lower mold fixing plate, a floating base plate, and a lower mold base from top to bottom. The lower mold base is fixed on the machine frame. The injection unit is fixed at the upper end of the upper mold fixing plate.

[0006] The pressurizing device includes an opening and closing mold cylinder fixed to the lower end of the lower mold base. The opening and closing mold cylinder has an oil chamber, and a piston rod is installed within the oil chamber. The lower end of the piston rod extends from the lower end of the cylinder, dividing the oil chamber into an inlet chamber and an outlet chamber. The inlet chamber is located above the piston rod, and the outlet chamber is located below the piston rod. It also includes a pressurizing cylinder, which has a pressurizing chamber formed within it. The pressurizing chamber is divided into a return oil chamber and a pressurizing chamber. The return oil chamber communicates with the outlet chamber of the opening and closing mold cylinder, and the pressurizing chamber communicates with the inlet chamber of the opening and closing mold cylinder. The device includes a booster push rod that passes through the oil return chamber and enters the pressurization chamber. The front end of the booster push rod has a circulation section containing an oil groove. The oil groove opens towards the front end and communicates with the pressurization chamber. The rear end of the circulation section has several circulation through holes formed around its periphery. The inner end of each circulation through hole communicates with the oil groove, and the outer end communicates with either the oil return chamber or the pressurization chamber. A sealing ring is provided between the oil return chamber and the pressurization chamber, and the booster push rod passes through the sealing ring. The booster device also includes a front and rear drive mechanism for the booster push rod.

[0007] With the above setup, when the circulation through-hole of the booster push rod advances into the pressure chamber, the oil in the return oil chamber cannot enter the pressure chamber due to the sealing ring. As the booster push rod continues to advance and compress the space in the pressure chamber, the oil pressure in the pressure chamber increases, and at the same time, the oil pressure in the inlet chamber of the mold opening and closing cylinder increases, causing the piston rod to generate a clamping force on the mold. When the circulation through-hole of the booster push rod retracts into the return oil chamber, since the oil groove of the circulation section is connected to the pressure chamber, and the circulation through-hole is connected to the oil groove, and the circulation through-hole retracts into the return oil chamber and connects with the return oil chamber, the pressure chamber and the return oil chamber are connected at this time, and no longer produce a boosting effect. The oil can circulate freely, thereby allowing the piston rod of the mold opening and closing cylinder to reset, facilitating mold opening. Therefore, this device has the effect of achieving pressure maintenance through the booster cylinder, which can reduce the occupied volume and ensure the clamping force.

[0008] The invention is further configured such that: the pressurizing device includes two mold opening and closing cylinders, and two pressurizing ports are provided in the pressurizing chamber. The two pressurizing ports are respectively connected to the liquid inlet chambers of the two mold opening and closing cylinders through pressurizing oil pipes.

[0009] By using two opening and closing mold cylinders, the force is more evenly distributed, and the pressure holding is more stable.

[0010] The present invention is further configured such that: an oil return port is provided in the oil return chamber, a three-way pipe is connected to the oil return port, one end of the three-way pipe is connected to a nitrogen tank, and the other end of the three-way pipe is connected to the liquid outlet chamber of the mold opening and closing cylinder through the oil return pipe.

[0011] The nitrogen tank acts as a buffer during charging, protecting the oil circuit.

[0012] The present invention is further configured such that: the booster push rod front and rear drive device includes a front bearing seat and a rear bearing seat, at least four guide pillars are provided between the front bearing seat and the rear bearing seat, a booster nut seat is provided and sleeved on the four guide pillars and can slide back and forth relative to the guide pillars, a booster screw nut is fixedly connected to the middle of the booster nut seat, a booster screw is also screwed into the booster screw nut, one end of the booster screw extends outward and is fixedly connected to the output end of the booster servo motor, the rear end of the booster push rod is fixedly connected to the booster nut seat, and the front end of the booster push rod extends into the booster cylinder.

[0013] With the above settings, the operation of the booster cylinder can be controlled by driving the booster rod to move via the booster servo motor, thus cooperating with the mold closing system and the injection molding system.

[0014] The invention is further configured such that: the booster cylinder includes a pressurizing section and a pressure cover; a pressurizing chamber is formed in the pressurizing section; an oil return chamber is formed in the pressure cover; the pressurizing section is fixed to the front end of the front bearing housing; the pressure cover is fixed to the rear end of the front bearing housing; a through hole is provided in the front bearing housing to connect the pressurizing chamber and the oil return chamber; a sealing ring is fixed in the through hole; and the booster push rod passes sequentially through the oil return chamber of the pressure cover and the sealing ring of the front bearing housing to reach the pressurizing chamber of the pressurizing section.

[0015] With the above settings, the through hole of the front bearing housing can be directly integrated into the booster cylinder, which makes the booster cylinder more stable and secure, and saves materials and reduces costs.

[0016] The present invention is further configured such that: the mold closing device includes at least four columns, the four columns are slidably connected to the lower mold base, the four columns can slide up and down relative to the lower mold base, the upper mold fixing plate is fixedly connected to the columns, and the lower ends of the four columns are also fixedly connected to a base plate; the lower end of the lower mold base is fixedly connected to a nut fixing seat, a mold closing nut is fixedly connected inside the nut fixing seat, a mold closing screw is rotatably connected to the middle of the base plate, the mold closing screw is axially fixed to the base plate, and the upper end of the mold closing screw extends into the nut fixing seat and is connected to the mold closing nut. The mold nut is screwed in, and the lower end of the mold closing screw is located below the base plate and is fixedly connected to a synchronous pulley. The lower end of the base plate is fixed with a mold closing servo motor, and the output end of the mold closing servo motor is connected to an output wheel. The output wheel and the synchronous pulley are connected by a synchronous belt. The rotation of the mold closing servo motor drives the mold closing screw to rotate. The mold closing screw rotates inside the mold closing nut, which generates up and down movement, thereby driving the base plate to move up and down. The up and down movement of the base plate drives the column to move up and down, and the up and down movement of the column drives the upper mold fixing plate to move up and down, thereby realizing the mold closing and mold opening movements.

[0017] With the above settings, the mold closing device can be driven by a mold closing servo motor, making mold opening and closing more agile. Furthermore, the mold opening and closing time and holding pressure time can be controlled by modifying the parameters of the servo motor. In conjunction with the booster servo motor, it can better adapt to various injection molding scenarios, making the injection molding machine more flexible and adaptable to a wider range of scenarios.

[0018] The present invention is further configured such that: the nut fixing seat is a hollow cylindrical structure, the lower end of the mold closing nut is fixedly connected to the lower end of the nut fixing seat, the upper end of the mold closing nut extends into the nut fixing seat, and a locking ring is also fixed to the lower end of the mold closing nut.

[0019] The present invention is further configured such that: the ejection mechanism includes a top block disposed in the floating base plate, and an ejection cylinder is fixed in the upper end of the hollow cavity of the nut fixing seat, and the output end of the ejection cylinder extends upward through the lower mold base and is fixedly connected to the top block.

[0020] With the above settings, the nut holder not only serves to fix the nut, but also to fix the ejector cylinder, thereby maximizing the function of the parts and making better use of space.

[0021] The present invention is further configured such that the mold clamping screw is axially fixed and rotatably connected to the base plate through two screw bearings.

[0022] The invention is further configured such that the lower end of the piston rod extends from the lower end of the oil cylinder and is fixedly connected to the base plate.

[0023] With the above settings, during pressurization, the piston rod can press downward against the base plate, thereby generating a downward clamping force on the upper mold fixing plate through the column. Furthermore, during mold opening, the piston rod automatically rises and resets along with the base plate.

[0024] The significant and beneficial technical effects of this invention compared to existing technologies are as follows: When the circulation through-hole of the booster push rod advances into the pressure chamber, the oil in the return oil chamber cannot enter the pressure chamber due to the sealing ring. As the booster push rod continues to advance and compress the space in the pressure chamber, the oil pressure in the pressure chamber increases, and simultaneously, the oil pressure in the inlet chamber of the mold opening and closing cylinder increases, causing the lower end of the piston rod to extend downwards and act on the mold to generate a clamping force. When the circulation through-hole of the booster push rod retracts into the return oil chamber, since the oil groove of the circulation section is connected to the pressure chamber, and the circulation through-hole is connected to the oil groove, and the circulation through-hole retracts into the return oil chamber, the pressure chamber and the return oil chamber are connected at this time, and no longer produce a boosting effect. The oil can circulate freely, thereby allowing the piston rod of the mold opening and closing cylinder to reset, facilitating mold opening. Therefore, this device has the effect of achieving pressure maintenance through the booster cylinder, which can reduce the occupied volume while ensuring the clamping force. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the present invention.

[0027] Figure 2 This is one of the structural schematic diagrams of the mold, mold closing device, and pressurizing device.

[0028] Figure 3 This is the second structural schematic diagram of the mold, mold closing device, and pressurizing device.

[0029] Figure 4 This is a schematic diagram of the booster device.

[0030] Figure 5 This is a schematic diagram of the internal structure of the booster cylinder.

[0031] Figure 6 for Figure 5 Enlarged view of point A.

[0032] Figure 7 This is a schematic diagram of the pressure booster push rod.

[0033] Figure 8 This is a schematic diagram of the internal structure of the mold opening and closing cylinder.

[0034] Figure 9 This is a schematic diagram of the mold and the mold closing device.

[0035] Figure 10 for Figure 9 Sectional view at BB.

[0036] 1-Injection molding device; 2-Mold; 3-Mold closing device; 4-Pressure boosting device; 5-Upper mold fixing plate; 6-Upper mold; 7-Lower mold; 8-Lower mold fixing plate; 9-Floating base plate; 10-Lower mold base; 11-Mold opening and closing cylinder; 12-Piston rod; 13-Inlet chamber; 14-Outlet chamber; 15-Pressure boosting cylinder; 16-Return oil chamber; 17-Pressure chamber; 18-Pressure boosting push rod; 19-Circulation section; 20-Oil tank; 21-Circulation through hole; 22-Sealing ring; 23-Pressure boosting port; 24-Pressure boosting oil pipe; 25-Return oil port; 26-Tee pipe; 2 7-Nitrogen tank; 28-Front bearing seat; 29-Rear bearing seat; 30-Guide post; 31-Pressure booster nut seat; 32-Pressure booster screw nut; 33-Pressure booster screw; 34-Pressure booster servo motor; 35-Pressure section; 36-Pressure cap; 37-Through hole; 38-Column; 39-Base plate; 40-Nut fixing seat; 41-Mold closing nut; 42-Mold closing screw; 43-Synchronous pulley; 44-Mold closing servo motor; 45-Output wheel; 46-Locking ring; 47-Ejector block; 48-Ejection cylinder; 49-Screw bearing; 50-Lower end of piston rod. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] An electric injection molding machine with a hydraulic booster cylinder and high-pressure clamping includes an injection molding device 1 (the injection molding device is prior art), a mold 2, a mold closing device 3, and a booster device 4. The mold 2 is provided with an upper mold fixing plate 5, an upper mold 6, a lower mold 7, a lower mold fixing plate 8, a floating base plate 9, and a lower mold base 10 from top to bottom. The lower mold base 10 is fixed on the machine frame. The injection molding device 1 is fixed at the upper end of the upper mold fixing plate 5.

[0039] The pressurizing device includes an opening and closing mold cylinder 11 fixed to the lower end of the lower mold base 10. The opening and closing mold cylinder 11 has an oil chamber, and a piston rod 12 is located within the oil chamber. The lower end of the piston rod 12 extends from the lower end of the cylinder, dividing the oil chamber into an inlet chamber 13 and an outlet chamber 14. The inlet chamber 13 is located above the piston rod 12, and the outlet chamber 14 is located below the piston rod 12. It also includes a pressurizing cylinder 15, which has a pressurizing chamber formed within it. The pressurizing chamber is divided into a return oil chamber 16 and a pressurizing chamber 17. The return oil chamber 16 communicates with the outlet chamber 14 of the opening and closing mold cylinder, and the pressurizing chamber 17 communicates with the inlet chamber 13 of the opening and closing mold cylinder. A booster push rod 18 is provided, which passes through the oil return chamber 16 and enters the pressurization chamber 17. The front end of the booster push rod 18 is provided with a circulation section 19, and an oil groove 20 is provided in the circulation section. The oil groove 20 opens towards the front end and communicates with the pressurization chamber 17. The rear end of the circulation section 19 is formed with a plurality of circulation through holes 21. The inner end of the circulation through holes 21 communicates with the oil groove 20, and the outer end of the circulation through holes 21 communicates with the oil return chamber 16 or the pressurization chamber 17. A sealing ring 22 is provided between the oil return chamber 16 and the pressurization chamber 17, and the booster push rod 18 passes through the sealing ring 22. The pressurization device also includes a booster push rod front and rear drive device.

[0040] With the above settings, when the circulation through-hole 21 of the booster push rod 18 advances into the pressure chamber 17, the oil in the return oil chamber 16 cannot enter the pressure chamber 17 due to the action of the sealing ring 22. When the booster push rod 18 continues to advance and compress the space of the pressure chamber 17, the oil pressure in the pressure chamber 17 will increase, and at the same time, the oil pressure in the liquid inlet chamber 13 of the mold opening and closing cylinder 11 will increase, causing the piston rod 12 to generate a clamping force acting on the mold. When the circulation through-hole 21 of the booster push rod 18 retracts into the return oil chamber 16, since the oil groove 20 of the circulation section 19 is connected to the pressure chamber 17, and the circulation through-hole 21 is connected to the oil groove 20, and the circulation through-hole retracts into the return oil chamber 16 and connects with the return oil chamber 16, the pressure chamber 17 and the return oil chamber 16 are connected at this time, and no longer produce a boosting effect. The oil can circulate freely, thereby allowing the piston rod 12 of the mold opening and closing cylinder to reset, facilitating mold opening. Therefore, this device can achieve pressure holding through a booster cylinder, which can reduce the occupied volume while ensuring the clamping force.

[0041] The pressurizing device includes two mold-opening and closing hydraulic cylinders 11. Two pressurizing ports 23 are provided within the pressurizing chamber 17, and the two pressurizing ports 23 are respectively connected to the inlet chambers 13 of the two mold-opening and closing hydraulic cylinders via pressurizing oil pipes 24. The use of two mold-opening and closing hydraulic cylinders ensures a more even distribution of force and more stable pressure holding.

[0042] The oil return chamber 16 is provided with an oil return port 25, and a three-way pipe 26 is connected to the oil return port 25. One end of the three-way pipe 26 is connected to a nitrogen tank 27, and the other end of the three-way pipe 26 is connected to the liquid outlet chamber 14 of the mold opening and closing cylinder through the oil return pipe. The nitrogen tank 27 serves as a buffer for energy charging and can protect the oil circuit.

[0043] The booster push rod front and rear drive device includes a front bearing seat 28 and a rear bearing seat 29. At least four guide pillars 30 are arranged between the front bearing seat 28 and the rear bearing seat 29. A booster nut seat 31 is provided and is sleeved on the four guide pillars 30 and can slide back and forth relative to the guide pillars. A booster screw nut 32 is fixedly connected to the middle of the booster nut seat 31. A booster screw 33 is also screwed into the booster screw nut 32. One end of the booster screw 33 extends outward and is fixedly connected to the output end of the booster servo motor 34. The rear end of the booster push rod 18 is fixedly connected to the booster nut seat 31, and the front end of the booster push rod 18 extends into the booster cylinder 15. With the above configuration, the movement of the booster rod can be driven by the booster servo motor 34 to control the operation of the booster cylinder to cooperate with the mold closing system and the injection molding system.

[0044] The booster cylinder 15 includes a pressurizing section 35 and a pressure cap 36. A pressurizing chamber 17 is formed within the pressurizing section 35, and an oil return chamber 16 is formed within the pressure cap 36. The pressurizing section 35 is fixed to the front end of the front bearing housing 28, and the pressure cap 36 is fixed to the rear end of the front bearing housing 28. A through hole 37 is provided in the front bearing housing 28, connecting the pressurizing chamber 17 and the oil return chamber 16. A sealing ring 22 is fixed within the through hole 37. The booster push rod 18 passes sequentially through the oil return chamber 16 of the pressure cap 36 and the sealing ring 22 of the front bearing housing to reach the pressurizing chamber 17 of the pressurizing section 35. This design allows the through hole 37 of the front bearing housing to directly become part of the booster cylinder 15, resulting in a more stable and secure fixation of the booster cylinder, while also saving materials and reducing costs.

[0045] The mold clamping device 3 includes at least four columns 38, which are slidably connected to the lower mold base 10 and can slide up and down relative to the lower mold base 10. The upper mold fixing plate 5 is fixedly connected to the columns 38, and the lower ends of the four columns 38 are also fixedly connected to a base plate 39. The lower end of the lower mold base 10 is fixedly connected to a nut fixing seat 40, and a mold clamping nut 41 is fixedly connected inside the nut fixing seat 40. A mold clamping screw 42 is rotatably connected to the middle of the base plate 39. The mold clamping screw 42 is axially fixed to the base plate 39, and the upper end of the mold clamping screw 42 extends into the nut fixing seat 40 and is screwed to the mold clamping nut 41. The lower end of the mold closing screw 42 is located below the base plate 39 and is fixedly connected to a synchronous wheel 43. The lower end of the base plate 39 is fixedly connected to a mold closing servo motor 44. The output end of the mold closing servo motor 44 is connected to an output wheel 45. The output wheel 45 and the synchronous wheel 43 are connected by a synchronous belt (not shown). The rotation of the mold closing servo motor 44 drives the mold closing screw 42 to rotate. The mold closing screw 42 rotates in the mold closing nut 41 and moves up and down, thereby driving the base plate 39 to move up and down. The up and down movement of the base plate 39 drives the column 38 to move up and down. The up and down movement of the column 38 drives the upper mold fixing plate 5 to move up and down, thereby realizing the mold closing and mold opening movements.

[0046] With the above settings, the mold closing device can be driven by the mold closing servo motor 44, making the mold opening and closing more agile. The mold opening and closing time and holding pressure time can be controlled by modifying the parameters of the servo motor. In addition, in conjunction with the booster servo motor 34, it can better adapt to various injection molding scenarios, making the injection molding machine more flexible and adaptable to a wider range of scenarios.

[0047] The nut fixing seat 40 is a hollow cylindrical structure. The lower end of the mold closing nut 41 is fixedly connected to the lower end of the nut fixing seat 40. The upper end of the mold closing nut 41 extends into the nut fixing seat 40. A locking ring 46 is also fixed to the lower end of the mold closing nut 41.

[0048] The floating base plate 9 is also equipped with an ejection mechanism, which includes a top block 47 disposed within the floating base plate. An ejection cylinder 48 is fixed within the upper end of the hollow cavity of the nut fixing seat 40. The output end of the ejection cylinder 48 extends upward through the lower mold base 10 and is fixedly connected to the top block 47. Through this arrangement, the nut fixing seat 40 not only serves to fix the mold closing nut 41 but also to fix the ejection cylinder 48, thereby maximizing the functionality of the part and increasing space utilization.

[0049] The mold clamping screw 42 is axially fixed and rotatably connected to the base plate 39 via two screw bearings 49.

[0050] The lower end 50 of the piston rod extends from the lower end of the oil cylinder and is fixedly connected to the base plate 39. With this configuration, when pressurized, the piston rod 12 can press downward against the base plate 39, thereby generating a downward clamping force on the upper mold fixing plate 5 through the column 38. Furthermore, when the mold is opened, the piston rod 12 automatically rises and resets along with the base plate 39.

[0051] Working principle:

[0052] During mold closing and pressure holding: The mold closing servo motor 44 rotates, driving the mold closing screw 42 to rotate. The mold closing screw 42 rotates within the mold closing nut 41, causing it to move downwards, thereby driving the base plate 39 to move downwards. The downward movement of the base plate 39 drives the column 38 to move downwards. The downward movement of the column 38 drives the upper mold fixing plate 5 to move downwards until the upper mold 6 and lower mold 7 under the upper mold fixing plate 5 complete the mold closing. Then, the booster servo motor 34 drives the booster push rod 18 forward, causing the circulation through hole 21 of the booster push rod 18 to advance into the pressurizing chamber 17. Due to the effect of the sealing ring 22, the oil in the return oil chamber 16 cannot enter the pressurizing chamber 17. When the booster push rod 18 continues to advance and squeezes the space of the pressurizing chamber 17, the oil pressure in the pressurizing chamber 17 will increase. At the same time, the oil pressure in the liquid inlet chamber 13 in the mold opening and closing cylinder 11 will increase, causing the lower end of the piston rod 12 to press down against the bottom plate 39, causing the bottom plate 39 to generate a downward force. Since the bottom plate 39 and the column 38 are fixedly connected, and the column 38 is fixedly connected to the upper mold fixing plate 5, the upper mold fixing plate 5 generates a downward clamping force.

[0053] During mold opening: First, the booster servo motor 34 controls the booster push rod 18 to retract. When the circulation through hole 21 of the booster push rod 18 retracts to the oil return chamber 16, since the oil groove 20 of the circulation section 19 is connected to the pressurization chamber 17, and the circulation through hole 21 is connected to the oil groove 20, and the circulation through hole 21 retracts to the oil return chamber 16 and is connected to the oil return chamber 16, the pressurization chamber 17 and the oil return chamber 16 are connected at this time, and no longer produce a boosting effect. The oil can circulate freely. Then, the mold closing servo motor 44 drives the rotation to drive the mold closing screw 42 to rotate in the opposite direction. The mold closing screw 42 rotates in the opposite direction in the mold closing nut 41 and moves upward, thereby driving the base plate 39 to move upward. The upward movement of the base plate 39 drives the piston rod 12 of the mold opening and closing cylinder to reset, and drives the column 38 to move upward. The upward movement of the column 38 drives the upper mold fixing plate 5 to move upward to complete the mold opening.

[0054] This invention features pressure holding achieved through a booster cylinder, which reduces the occupied volume while ensuring clamping force.

[0055] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking, comprising an injection unit, a mold, a mold clamping unit, and a booster unit, characterized in that, The mold is provided from top to bottom as follows: upper mold fixing plate, upper mold, lower mold, lower mold fixing plate, floating base plate and lower mold base, with the lower mold base fixed on the frame; the injection molding device is fixed at the upper end of the upper mold fixing plate. The pressurizing device includes an opening and closing mold cylinder fixed to the lower end of the lower mold base. The opening and closing mold cylinder has an oil chamber, and a piston rod is installed within the oil chamber. The lower end of the piston rod extends from the lower end of the cylinder, dividing the oil chamber into an inlet chamber and an outlet chamber. The inlet chamber is located above the piston rod, and the outlet chamber is located below the piston rod. It also includes a pressurizing cylinder, which has a pressurizing chamber formed within it. The pressurizing chamber is divided into a return oil chamber and a pressurizing chamber. The return oil chamber communicates with the outlet chamber of the opening and closing mold cylinder, and the pressurizing chamber communicates with the inlet chamber of the opening and closing mold cylinder. The device includes a booster push rod that passes through the oil return chamber and enters the pressurization chamber. The front end of the booster push rod has a circulation section containing an oil groove. The oil groove opens towards the front end and communicates with the pressurization chamber. The rear end of the circulation section has several circulation through holes formed around its periphery. The inner end of each circulation through hole communicates with the oil groove, and the outer end communicates with either the oil return chamber or the pressurization chamber. A sealing ring is provided between the oil return chamber and the pressurization chamber, and the booster push rod passes through the sealing ring. The booster device also includes a front and rear drive mechanism for the booster push rod.

2. The electric injection molding machine with high-pressure mold locking and hydraulic booster cylinder according to claim 1, characterized in that: The pressurizing device includes two mold opening and closing cylinders, and two pressurizing ports are provided in the pressurizing chamber. The two pressurizing ports are respectively connected to the liquid inlet chambers of the two mold opening and closing cylinders through pressurizing oil pipes.

3. The electric injection molding machine with high-pressure mold locking and hydraulic booster cylinder according to claim 1, characterized in that: The oil return chamber is equipped with an oil return port, and a three-way pipe is connected to the oil return port. One end of the three-way pipe is connected to a nitrogen tank, and the other end of the three-way pipe is connected to the liquid outlet chamber of the mold opening and closing cylinder through the oil return pipe.

4. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking as described in claim 1, characterized in that: The booster push rod front and rear drive device includes a front bearing seat and a rear bearing seat. At least four guide pillars are arranged between the front bearing seat and the rear bearing seat. A booster nut seat is provided and is sleeved on the four guide pillars and can slide back and forth relative to the guide pillars. A booster screw nut is fixedly connected to the middle of the booster nut seat. A booster screw is also screwed into the booster screw nut. One end of the booster screw extends outward and is fixedly connected to the output end of the booster servo motor. The rear end of the booster push rod is fixedly connected to the booster nut seat, and the front end of the booster push rod extends into the booster cylinder.

5. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking as described in claim 4, characterized in that: The booster cylinder includes a pressurizing section and a pressure cover. The pressurizing section has a pressurizing chamber formed inside, and the pressure cover has an oil return chamber formed inside. The pressurizing section is fixed to the front end of the front bearing housing, and the pressure cover is fixed to the rear end of the front bearing housing. The front bearing housing has a through hole connecting the pressurizing chamber and the oil return chamber. A sealing ring is fixed inside the through hole. The booster push rod passes through the oil return chamber of the pressure cover and the sealing ring of the front bearing housing in sequence to reach the pressurizing chamber of the pressurizing section.

6. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking according to claim 1, characterized in that: The mold closing device includes at least four columns, which are slidably connected to the lower mold base and can slide up and down relative to the lower mold base. The upper mold fixing plate is fixedly connected to the columns, and the lower ends of the four columns are also fixedly connected to a base plate. The lower end of the lower mold base is fixedly connected to a nut fixing seat, and a mold closing nut is fixedly connected inside the nut fixing seat. A mold closing screw is rotatably connected to the middle of the base plate. The mold closing screw is axially fixed to the base plate. The upper end of the mold closing screw extends into the nut fixing seat and is screwed to the mold closing nut. The lower end of the mold closing screw is located below the base plate and is fixedly connected to a synchronous wheel. A mold closing servo motor is fixed to the lower end of the base plate. The output end of the mold closing servo motor is connected to an output wheel, and the output wheel and the synchronous wheel are connected by a synchronous belt. The rotation of the mold closing servo motor drives the mold closing screw to rotate. The rotation of the mold closing screw inside the mold closing nut generates up and down movement, thereby driving the base plate to move up and down. The up and down movement of the base plate drives the columns to move up and down, and the up and down movement of the columns drives the upper mold fixing plate to move up and down, thereby realizing the mold closing and mold opening movements.

7. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking according to claim 6, characterized in that: The nut fixing seat is a hollow cylindrical structure. The lower end of the mold closing nut is fixedly connected to the lower end of the nut fixing seat. The upper end of the mold closing nut extends into the nut fixing seat. A locking ring is also fixed to the lower end of the mold closing nut.

8. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking according to claim 7, characterized in that: The floating base plate is also equipped with an ejection mechanism, which includes a top block disposed in the floating base plate. An ejection cylinder is fixed in the upper end of the hollow cavity of the nut fixing seat. The output end of the ejection cylinder extends upward through the lower mold base and is fixedly connected to the top block.

9. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking according to claim 6, characterized in that: The mold clamping screw is axially fixed and rotatably connected to the base plate through two screw bearings.

10. An electric injection molding machine with a hydraulic booster cylinder and high-pressure mold locking according to claim 6, characterized in that: The lower end of the piston rod extends from the lower end of the oil cylinder and is fixedly connected to the base plate.

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