A double screw drive mechanism for the injection device of a fully electric injection molding machine

Abstract

The present invention discloses a double-screw drive mechanism for an injection device of a fully electric injection molding machine, comprising an injection seat, a pre-molding seat, and a lead screw. The injection seat is provided with an injection barrel, the pre-molding seat is connected to an injection screw, the rear end of the injection screw is rotatably disposed within the pre-molding seat, a lead screw nut is disposed within the injection seat, and the front end of the lead screw is threadedly mounted to the lead screw nut. The invention is characterized in that the injection seat has a first mounting cavity that is through-and-through, the lead screw nut is fixedly disposed within the first mounting cavity, the front end of the first mounting cavity is provided with a protective sleeve with a closed front end, the inner cavity of the protective sleeve forms a travel chamber for the lead screw to move forward and backward; a protective cylinder is provided between the pre-molding seat and the injection seat, and the protective cylinder is sleeved on the outside of the lead screw. The advantages of the double-screw drive mechanism are that the structure is simple, the lead screw is effectively protected, thereby effectively ensuring the service life of the lead screw and achieving controllable manufacturing costs.

Description

Technical Field

[0001] The present invention relates to the field of all-electric injection molding machines, in particular to a double-screw driving mechanism for an injection device of an all-electric injection molding machine. Background Art

[0002] Injection and melt molding in all-electric injection molding machines are typically accomplished by a motor-driven lead screw that pushes the screw. The lead screw bears almost the entire injection force throughout the injection process. Current lead screw manufacturing technology can only meet the injection force requirements of small and medium-sized all-electric injection molding machines. As technology advances, all-electric injection molding machines are gradually becoming larger, and injection force is also increasing. However, due to the relatively slow development of lead screw manufacturing technology, large all-electric injection molding machines often use a dual lead screw drive mechanism to drive the screw injection. The double-screw drive mechanism on the existing all-electric injection molding machine usually includes two screws, one end of the screw is rotatably mounted on the pre-molding seat of the injection molding machine, the pre-molding seat is connected to the injection screw, and the injection seat of the injection molding machine for supporting the injection barrel is provided with a screw nut that matches the screw, and the other end of the screw is screwed on the screw nut. The screw is driven to rotate by a driving component (such as a driving motor) to realize the movement of the pre-molding seat on the frame of the injection molding machine and drive the injection screw to perform the injection action. The screw in this double-screw drive mechanism is usually directly exposed to the outside, so the screw is easily affected by the external environment (such as dust, air humidity, etc.), which will reduce the service life of the screw and is not conducive to the control of manufacturing costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a double-screw drive mechanism for an injection device of a full-electric injection molding machine, which can effectively ensure the service life of the screw and make the manufacturing cost controllable.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A double-screw drive mechanism for the injection device of a fully electric injection molding machine comprises an injection seat fixedly arranged on the frame of the injection molding machine, a pre-molding seat movably arranged on the frame of the injection molding machine, and two parallel screws, wherein the injection seat is provided with an injection barrel, the pre-molding seat is connected to an injection screw, the injection screw is rotatable and can be moved forward and backward to extend into the injection barrel, the rear end of the screw is rotatably arranged in the pre-molding seat, a screw nut matching the screw is arranged in the injection seat, the front end of the screw is screwed with the corresponding screw nut, and the injection The shooting seat has a first mounting cavity that passes through from front to back, and the screw nut is fixedly arranged in the first mounting cavity. The front port of the first mounting cavity is provided with a protective sleeve with a closed front end, and the inner cavity of the protective sleeve forms a travel chamber for the screw to move back and forth; a protective cylinder is provided between the pre-molding seat and the injection seat, and the protective cylinder is sleeved on the outside of the screw. The rear end of the protective cylinder is fixedly installed on the pre-molding seat, and the front end of the protective cylinder is extended into the first mounting cavity and can move back and forth in the first mounting cavity driven by the pre-molding seat.

[0006] The front end of the first mounting cavity is provided with a mounting seat for mounting the lead screw nut. The mounting seat has a central movable hole that is coaxial with the lead screw and can be passed through. The lead screw nut is coaxially fixedly mounted at the rear end of the mounting seat and located within the first mounting cavity. The protective sleeve is coaxially mounted at the front end of the mounting seat. The mounting seat ensures stable installation of the protective sleeve and lead screw nut.

[0007] The front end of the lead screw has a coaxial limit end, onto which is threaded an anti-collision limit ring. The anti-collision limit ring comprises a limit portion and a mounting portion coaxially arranged from front to back. The outer diameter of the limit portion is larger than the inner diameter of the central movable hole, while the outer diameter of the mounting portion is smaller than the inner diameter of the central movable hole. The cooperation between the limit end and the anti-collision limit ring limits the position of the lead screw in its backward movement.

[0008] The pre-molding seat is provided with a second mounting cavity that extends from front to back. The rear end of the protective cylinder is fixedly mounted at the front end of the second mounting cavity. A bearing seat is disposed within the second mounting cavity. The rear end of the lead screw is rotatably connected to the bearing seat via a bearing disposed within the bearing seat. This structure allows for stable, rotatable mounting of the lead screw within the pre-molding seat, resulting in a simple, stable, and low-cost structure.

[0009] The rear end of the lead screw extends rearwardly from the bearing seat and is locked and fixed by a nut assembly. The nut assembly includes a first locking nut and a second locking nut arranged in sequence from front to back. The rear end of the bearing seat has a bearing retaining ring for limiting the bearing. The first locking nut is threaded onto the rear end of the lead screw and abuts against the rear of the bearing retaining ring. The second locking nut is threaded onto the rear end of the lead screw and abuts against the rear of the first locking nut. The above structure locks the installation position of the rear end of the lead screw within the second installation cavity.

[0010] The rear end of the first mounting cavity is provided with a rear end cover with a mounting hole in the center that passes through the front and back for the front end of the protective cylinder to extend into the first mounting cavity. The front end of the rear end cover is provided with an insertion mounting portion that extends into and is installed in the first mounting cavity. A sealing member is provided between the outer wall of the insertion mounting portion and the inner wall of the first mounting cavity. The front end of the protective cylinder passes through the mounting hole and extends into the first mounting cavity. A sealing member is provided between the outer wall of the protective cylinder and the inner wall of the mounting hole. A sealing member is provided between the outer wall of the bearing seat and the inner wall of the second mounting cavity. The mounting seat is sealed and connected to the first mounting cavity to form a sealed space between the first mounting cavity, the inner cavity of the protective cylinder and the second mounting cavity. The injection seat is provided with an oil filling port connected to the first mounting cavity. Cooling oil can be injected into the sealed space through the oil filling port so that the screw is immersed in the cooling oil. This can effectively reduce the impact of the heat generated during work on the screw. Secondly, the oil can be used as a lubricant to effectively ensure the service life of the screw and improve the working efficiency of the screw.

[0011] The oil filling port is detachably provided with a sealing plug. After the cooling oil is injected, the sealing plug is covered to seal the oil filling port.

[0012] The lead screw is driven to rotate by a drive assembly, which includes a drive motor, a small pulley, and a large pulley. The small pulley is coaxially fixedly connected to the output shaft of the drive motor, and the large pulley is coaxially fixedly mounted on the rear end of the lead screw. The large pulley and the small pulley are connected by a belt. The drive assembly has a simple structure and stable drive. The cooperation between the large and small pulleys achieves deceleration.

[0013] The mounting base has a pressure sensor that feeds back pressure signals to the controller in real time. The controller adjusts the output torque of the injection motor to achieve precise control of injection pressure and holding pressure.

[0014] Compared with the existing technology, the advantages of the present invention are: by combining the protective sleeve, injection seat, protective cylinder and pre-plastic seat together, the screw is completely enclosed in a complete closed space, effectively avoiding the shortening of the service life of the screw due to being exposed to the external environment. The structure is simple and effectively protects the screw, thereby effectively ensuring the service life of the screw and achieving controllable manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic cross-sectional view of the present invention applied to an injection molding machine;

[0016] Figure 2 for Figure 1 Schematic diagram of the enlarged structure at A in the middle;

[0017] Figure 3 This is a side structural schematic diagram of the present invention applied to an injection molding machine;

[0018] Figure 4 It is a side structural schematic diagram of the present invention applied to an injection molding machine. DETAILED DESCRIPTION

[0019] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0020] like Figures 1 to 4 As shown, a double-screw drive mechanism for the injection device of a fully electric injection molding machine includes an injection seat 2 fixedly arranged on the injection molding machine frame 1, a pre-molding seat 3 movably arranged on the injection molding machine frame 1, and two parallel screws 4. An injection barrel 21 is arranged on the injection seat 2, and an injection screw 31 is connected to the pre-molding seat 3. The injection screw 31 is rotatable and can be moved forward and backward to extend into the injection barrel 21. The rear end of the screw 4 is rotatably arranged in the pre-molding seat 3. A screw nut 5 that cooperates with the screw 4 is arranged in the injection seat 2, and the front end of the screw 4 is screwed and installed with the corresponding screw nut 5. The injection seat 2 has a first installation cavity 201 that passes through from front to back, the screw nut 5 is fixedly arranged in the first installation cavity 201, and the front end of the first installation cavity 201 is provided with a protective sleeve 6 with a closed front end, and the inner cavity of the protective sleeve 6 forms a stroke chamber 61 for the screw 4 to move back and forth; a protective cylinder 7 is provided between the pre-molding seat 3 and the injection seat 2, and the protective cylinder 7 is sleeved on the outside of the screw 4, and the rear end of the protective cylinder 7 is fixedly installed on the pre-molding seat 3, and the front end of the protective cylinder 7 is extended into the first installation cavity 201 and can move back and forth in the first installation cavity 201 driven by the pre-molding seat 3.

[0021] In this specific embodiment, a mounting seat 8 for mounting the lead screw nut 5 is provided at the front end of the first mounting cavity 201. The mounting seat 8 has a central movable hole 81 that is coaxial with the lead screw 4 and can be passed through by the lead screw 4. The lead screw nut 5 is coaxially fixedly mounted at the rear end of the mounting seat 8 and located within the first mounting cavity 201. The protective sleeve 6 is coaxially mounted at the front end of the mounting seat 8. The mounting seat 8 ensures stable installation of the protective sleeve 6 and the lead screw nut 5.

[0022] In this specific embodiment, the front end of the lead screw 4 has a coaxial limit end 41, on which an anti-collision limit ring 9 is screwed. The anti-collision limit ring 9 includes a limit portion 91 and a mounting portion 92 coaxially arranged from front to back. The outer diameter of the limit portion 91 is larger than the inner diameter of the central movable hole 81, and the outer diameter of the mounting portion 92 is smaller than the inner diameter of the central movable hole 81. The cooperation between the limit end 41 and the anti-collision limit ring 9 realizes the positional limitation of the backward position of the lead screw 4.

[0023] In this embodiment, the pre-molding seat 3 is provided with a second mounting cavity 32 that extends from front to back. The rear end of the protective cylinder 7 is fixedly mounted at the front end of the second mounting cavity 32. A bearing seat 10 is disposed within the second mounting cavity 32. The rear end of the lead screw 4 is rotatably connected to the bearing seat 10 via a bearing 101 disposed within the bearing seat 10. This structure ensures stable, rotatable mounting of the lead screw 4 within the pre-molding seat 3, resulting in a simple, stable, and low-cost structure.

[0024] In this specific embodiment, the rear end of the lead screw 4 extends rearwardly out of the bearing seat 10 and is locked and fixed by a nut assembly. The nut assembly includes a first locking nut 42 and a second locking nut 43 arranged in sequence from front to back. The rear end of the bearing seat 10 has a bearing retaining ring 102 for limiting the bearing 101. The first locking nut 42 is screwed onto the rear end of the lead screw 4 and abuts against the rear of the bearing retaining ring 102. The second locking nut 43 is screwed onto the rear end of the lead screw 4 and abuts against the rear of the first locking nut 42. The above structure locks the rear end of the lead screw 4 in the installation position within the second installation cavity 32.

[0025] In this specific embodiment, a rear end cover 11 is provided in the rear port of the first mounting cavity 201, and the center has a mounting hole (not shown in the figure) that passes through from front to back for the front end of the protective cylinder 7 to extend into the first mounting cavity 201. The front end of the rear end cover 11 is provided with an inserting mounting portion 112 that extends and is installed in the first mounting cavity 201. A sealing member 13 is provided between the outer wall of the inserting mounting portion 112 and the inner wall of the first mounting cavity 201. The front end of the protective cylinder 7 passes through the mounting hole and extends into the first mounting cavity 201. A sealing member 13 is provided between the outer wall of the protective cylinder 7 and the inner wall of the mounting hole. A sealing member 13 is provided between the outer wall of the bearing seat 10 and the inner wall of the second mounting cavity 32. The mounting seat 8 is sealedly connected to the first mounting cavity 201, so that a sealed space is formed between the first mounting cavity 201, the inner cavity of the protective cylinder 7 and the second mounting cavity 32. The injection seat 2 is provided with an oil filling port (not shown in the figure) connected to the first mounting cavity 201. Cooling oil can be injected into the sealed space through the oil filling port, so that the screw 4 is immersed in the cooling oil. This can effectively reduce the impact of the heat generated during the working process on the screw 4. Secondly, the oil can be used as a lubricating oil, effectively ensuring the service life of the screw 4 and improving the working efficiency of the screw 4.

[0026] In this embodiment, the oil filling port is detachably provided with a sealing plug 23. After the cooling oil is injected, the sealing plug 23 is covered to seal the oil filling port.

[0027] In this specific embodiment, the lead screw 4 is driven to rotate by a drive assembly, which includes a drive motor 14, a small pulley 15, and a large pulley 16. The small pulley 15 is coaxially fixedly connected to the output shaft 141 of the drive motor 14, and the large pulley 16 is coaxially fixedly mounted on the rear end of the lead screw 4. The large pulley 16 and the small pulley 15 are connected by a belt 17. The above drive assembly has a simple structure and stable drive. The cooperation between the large pulley 16 and the small pulley 15 achieves deceleration.

[0028] In this embodiment, the mounting base 8 has a pressure sensor. The pressure sensor feeds back the pressure signal to the controller in real time, and the controller adjusts the output torque of the injection motor to achieve precise control of the injection pressure and the holding pressure.

Claims

1. A double-screw drive mechanism for an injection device of a fully electric injection molding machine, comprising an injection seat fixedly mounted on a frame of the injection molding machine, a pre-molding seat movably mounted on the frame of the injection molding machine, and two parallel screws, wherein an injection barrel is mounted on the injection seat, an injection screw is connected to the pre-molding seat, the injection screw is rotatable and can be moved forward and backward into the injection barrel, the rear end of the screw is rotatably mounted in the pre-molding seat, a screw nut cooperating with the screw is mounted in the injection seat, and the front end of the screw is threadedly mounted with the corresponding screw nut, characterized in that The injection seat has a first mounting cavity that passes through from front to back, the lead screw nut is fixedly arranged in the first mounting cavity, the front end of the first mounting cavity is provided with a protective sleeve with a closed front end, and the inner cavity of the protective sleeve forms a stroke chamber for the lead screw to move back and forth; a protective cylinder is provided between the pre-molding seat and the injection seat, the protective cylinder is sleeved on the outside of the lead screw, the rear end of the protective cylinder is fixedly installed on the pre-molding seat, the front end of the protective cylinder is extended into the first mounting cavity and can move back and forth in the first mounting cavity driven by the pre-molding seat; The front end of the first mounting cavity is provided with a mounting seat for mounting the lead screw nut, the mounting seat having a central movable hole that is coaxial with the lead screw and can be passed through by the lead screw, the lead screw nut is coaxially fixedly mounted at the rear end of the mounting seat and located in the first mounting cavity, and the protective sleeve is coaxially mounted at the front end of the mounting seat; The pre-molding seat is provided with a second mounting cavity which is continuous from front to back. The rear end of the protective cylinder is fixedly mounted on the front end of the second mounting cavity. A bearing seat is provided in the second mounting cavity. The rear end of the lead screw is rotatably connected to the bearing seat via a bearing, and the bearing is provided in the bearing seat. The rear end of the first mounting cavity is provided with a rear end cover with a mounting hole in the center that passes through the front and back for the front end of the protective cylinder to extend into the first mounting cavity. The front end of the rear end cover is provided with an insertion mounting portion that extends into and is installed in the first mounting cavity. A sealing member is provided between the outer wall of the insertion mounting portion and the inner wall of the first mounting cavity. The front end of the protective cylinder passes through the mounting hole and extends into the first mounting cavity. A sealing member is provided between the outer wall of the protective cylinder and the inner wall of the mounting hole. A sealing member is provided between the outer wall of the bearing seat and the inner wall of the second mounting cavity. The mounting seat is sealed and connected to the first mounting cavity, so that a sealed space is formed between the first mounting cavity, the inner cavity of the protective cylinder and the second mounting cavity. The injection seat is provided with an oil filling port connected to the first mounting cavity. The mounting seat has a pressure sensor.

2. A double screw drive mechanism for an injection device of a fully electric injection molding machine according to claim 1, characterized in that The front end of the screw has a coaxial limiting end, and an anti-collision limiting ring is screwed on the limiting end. The anti-collision limiting ring includes a limiting part and an installation part coaxially arranged from front to back. The outer diameter of the limiting part is larger than the inner diameter of the central movable hole, and the outer diameter of the installation part is smaller than the inner diameter of the central movable hole.

3. A double screw drive mechanism for an injection device of a fully electric injection molding machine according to claim 1, characterized in that The rear end head of the screw extends backward and the bearing seat is locked and fixed by a nut assembly. The nut assembly includes a first locking nut and a second locking nut arranged in sequence from front to back. The rear end of the bearing seat has a bearing retaining ring for limiting the bearing. The first locking nut is screwed to the rear end of the screw and is abutted against the rear of the bearing retaining ring. The second locking nut is screwed to the rear end of the screw and is abutted against the rear of the first locking nut.

4. A double screw drive mechanism for an injection device of a fully electric injection molding machine according to claim 1, characterized in that A sealing plug is detachably provided on the oil filling port.

5. A double screw drive mechanism for an injection device of a fully electric injection molding machine according to claim 1, characterized in that The screw is driven to rotate by a driving assembly, which includes a driving motor, a small pulley and a large pulley. The small pulley is coaxially fixedly connected to the output shaft of the driving motor, and the large pulley is coaxially fixedly installed on the rear end head of the screw. The large pulley and the small pulley are connected by a belt.

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