Glue injection device of injection molding machine

Abstract

The invention relates to the technical field of injection molding and glue injection devices, and particularly discloses a glue injection device of an injection molding machine. The pushing seat is slidably arranged on the base, an injection molding barrel is arranged on the base, and an extrusion molding rod is arranged in the injection molding barrel; the multiple oil cylinders are arranged on the base, piston rods are arranged in the oil cylinders in a sealed and sliding mode, one ends of the piston rods are connected with the pushing base, oil return barrels are arranged in the oil cylinders in the axial direction, second piston cavities are formed in the piston rods, and the oil return barrels are in sealed and sliding fit with the second piston cavities in the piston rods. The force storage buffer cylinder is elastically arranged in the piston cavity II; the limiting assembly is arranged in the second piston cavity, and an ejector rod is slidably arranged in the force storage buffer cylinder. According to the glue injection device of the injection molding machine, buffering force is converted into impact force, the oil return barrel is pushed at the moment of oil return, and therefore high-speed extrusion molding can be achieved, and meanwhile the service life of the oil cylinder can be guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of plastic injection devices, and in particular to a plastic injection device of an injection molding machine. Background Art

[0002] The injection device of the injection molding machine is mainly used to make thermoplastic plastics or thermosetting plastics into plastic products of various shapes through plastic molding molds. The working principle of the injection molding machine is similar to that of a syringe. It uses the thrust of a screw or a plunger to inject the plasticized molten plastic into a closed mold cavity at high pressure and speed. After cooling and solidification, a plastic product with a shape almost consistent with that of the mold is obtained. The injection molding device is mainly composed of an injection system, a clamping mechanism, and a hydraulic and control system.

[0003] In the Chinese patent with the announcement number CN117885308B, a glue injection control device, a glue injection system for an injection molding machine and an injection molding machine are disclosed, including a glue injection control device that changes the glue injection push rod driven by the oil pump to the glue injection control device. The first piston is driven by the oil pump to move and drive the second piston to move, and the hydraulic oil in the fourth cavity is driven by the second piston to enter the glue injection drive oil circuit and drive the glue injection push rod, and the material is injected into the mold by the glue injection push rod. Since the piston area of ​​the second piston is larger than the area of ​​the first piston, the first cavity can be injected with hydraulic oil according to the working power of the crude oil pump, and the amount of hydraulic oil in the fourth cavity that is pressed into the glue injection drive oil circuit is greater than the amount of hydraulic oil in the first cavity. Thus, the purpose of rapid glue injection can be achieved, the working power of the crude oil pump motor group is not changed or the power is reduced, and the same power consumption as the original is maintained, and the processing cost is not increased.

[0004] The above patent document achieves the purpose of rapid injection by pressing the hydraulic oil in the fourth cavity into the injection drive oil circuit in an amount greater than the amount of hydraulic oil in the first cavity. The existing injection device realizes injection molding by pushing the screw through the cylinder. However, in order to realize high-speed injection molding, the existing injection device is prone to damage the seals or moving components inside the cylinder, thereby reducing the service life of the cylinder, making it difficult to ensure the high-speed injection molding of the cylinder while ensuring the service life of the cylinder. Summary of the invention

[0005] The present invention provides a glue injection device for an injection molding machine, aiming to solve the problem in the related art that high-speed injection molding easily causes damage to the seals or moving components inside the oil cylinder, thereby reducing the service life of the oil cylinder, making it difficult to ensure the high-speed injection molding of the oil cylinder while ensuring the service life of the oil cylinder.

[0006] A glue injection device for an injection molding machine of the present invention comprises: Base; The push seat is slidably arranged on the base, an injection molding cylinder is arranged on the base, an extrusion rod is arranged inside the injection molding cylinder, and a side wall of the push seat is connected to one end of the extrusion rod; A plurality of oil cylinders are arranged on the base, a piston rod is provided inside the oil cylinder in a sealing and sliding manner, one end of the piston rod is connected to the push seat, so that the movement of the piston rod can drive the push seat to move, an oil return cylinder is provided inside the oil cylinder along the axial direction, a piston chamber 2 is provided inside the piston rod, and the oil return cylinder and the piston chamber 2 in the piston rod are in sealing and sliding cooperation; A force storage buffer cylinder is elastically arranged inside the second piston chamber, and is used to buffer and store force when the piston rod collides with the oil return cylinder; The limit assembly is arranged inside the second piston chamber, and the limit assembly can limit the buffering force of the collision between the force storage buffer cylinder and the oil return cylinder. A push rod is slidably arranged inside the force storage buffer cylinder, and the return oil of the oil return cylinder can drive the push rod to move so that the limit assembly releases the limit on the force storage buffer cylinder.

[0007] Preferably, a piston chamber is opened inside the oil cylinder, and the piston chamber is opened along the axial direction of the oil cylinder. The piston rod sliding seal is arranged inside the piston chamber, and the piston rod is composed of a disc and a cross bar. The right end of the cross bar extends out of the oil cylinder, and the right end of the cross bar is connected to the outer wall of one side of the push seat. An oil inlet hole is arranged on the top of the oil cylinder, and the oil inlet hole is connected to an external oil pumping device.

[0008] Preferably, the oil return cylinder is arranged inside the piston chamber one along the axial direction, and an oil return chamber is opened inside the oil return cylinder, and the internal space of the oil return chamber is smaller than the space inside the piston chamber one.

[0009] Preferably, an elastic member 1 is provided inside the piston chamber 2, a baffle is provided on the side wall of one end of the force storage buffer cylinder, and one end of the elastic member 1 is fixedly connected to the baffle, and the other end of the elastic member 1 is connected to the inner wall of the right end portion of the piston chamber 2, so that the force storage buffer cylinder is elastically arranged at the right end of the piston chamber 2, a slideway is axially opened inside the force storage buffer cylinder, and the push rod is slidably arranged on the slideway inside the force storage buffer cylinder.

[0010] Preferably, the limit assembly includes: a limit rod, a limit groove, a U-shaped air channel, a first T-type valve, a second T-type valve and a third extension rod, the limit rod is elastically arranged on two opposite side walls of the power storage buffer cylinder, a concave cavity is opened inside the piston rod, the U-shaped air channel is opened on the opposite side walls of the concave cavity, and the openings of the U-shaped air channel are all facing the concave cavity and connected to the concave cavity.

[0011] Preferably, the internal sliding seal of the U-shaped airway is provided with a first T-shaped valve and a second T-shaped valve, and the first T-shaped valve and the second T-shaped valve respectively correspond to an opening, and the first T-shaped valve is elastically arranged inside the U-shaped airway, the bottom end of the first T-shaped valve extends to the opening of the U-shaped airway, and the bottom end of the second T-shaped valve is located above the limiting groove.

[0012] Preferably, a support plate is provided on the right end face of the force storage buffer cylinder, and a third extension rod is elastically provided on the support plate, and the third extension rod is perpendicular to the support plate, the bottom end of the third extension rod extends out of the support plate, and the bottom end of the third extension rod is provided with an inclined surface, the right end of the extension rod extends to the interior of the concave cavity, and an elastic member 2 is provided inside the concave cavity, the elastic member 2 is connected to the right end of the extension rod, so that the elastic member 2 elastically supports the extension rod, and the diameter of the extension rod is smaller than the diameter of the return oil chamber, so that the extension rod can be inserted into the interior of the return oil chamber, and the outer wall of the extension rod is symmetrically provided with fixing rods.

[0013] Preferably, a Laval tube is provided on the side wall of one end of the oil cylinder, and one end of the Laval tube is connected to the oil return pump, and the other end of the Laval tube is connected to the left end of the oil return cylinder.

[0014] The beneficial effects of the present invention are: When the model is subjected to high-speed injection molding, the oil inlet of the cylinder drives the piston rod to move, and the movement of the piston rod drives the push seat to move, and the movement of the push seat drives the extrusion rod to move in the injection cylinder, so that the extrusion rod squeezes the plastic liquid required for injection molding into the mold, and at the same time, the return oil cylinder will be inserted into the interior of the piston chamber 2 when the piston rod moves. When the top of the return oil cylinder is pressed against the force storage buffer cylinder inside the piston chamber 2, the extrusion rod will extrude all the plastic liquid into the mold. At the same time, the force storage buffer cylinder can elastically support the return oil cylinder to avoid violent collision between the piston rod and the return oil cylinder, thereby improving the service life of the internal seal of the oil cylinder. At the same time, the limit assembly limits the buffering force of the force storage buffer cylinder. When the return oil cylinder returns oil to drive the piston rod to move in the opposite direction, the oil pressure will first impact the push rod to cause the push rod to move. The movement of the push rod drives the limit assembly to release the limit of the force storage buffer cylinder, so that the force storage buffer cylinder forms a reverse thrust to move the return oil cylinder away from the piston rod, thereby further improving the injection molding efficiency of the injection molding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is a schematic structural diagram of an injection molding cylinder of the present invention.

[0017] Figure 3 It is a schematic diagram of the oil cylinder structure of the present invention.

[0018] Figure 4 It is a schematic diagram of the piston rod structure of the present invention.

[0019] Figure 5 The present invention Figure 4 Enlarged view of point A in the middle.

[0020] Figure 6 It is a schematic diagram of the U-shaped airway structure of the present invention.

[0021] Reference numerals: 10. Base; 20. Push seat; 30. Injection cylinder; 40. Oil cylinder; 41. Piston rod; 42. Piston chamber 2; 43. Oil return cylinder; 44. Piston chamber 1; 45. Oil inlet hole; 46. Oil return chamber; 48. Laval tube; 50. Power storage buffer cylinder; 51. Push rod; 52. Baffle; 53. Elastic part 1; 60. Limit rod; 61. Limit groove; 62. U-shaped airway; 63. First T-type valve; 64. Second T-type valve; 65. Support plate; 66. Third push rod; 67. Inclined surface; 70. Concave cavity; 71. Elastic part 2; 72. Fixed rod. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0023] like Figures 1 to 6 As shown, a glue injection device of an injection molding machine of the present invention comprises a base 10, an injection cylinder 30 and a push seat 20, wherein the push seat 20 is slidably arranged on the top of the base 10, the injection cylinder 30 is arranged along the length direction of the base 10, an extrusion rod is arranged inside the injection cylinder 30, and the push seat 20 can drive the extrusion rod to move back and forth, and further comprises: an oil cylinder 40, a piston rod 41, an oil return cylinder 43, a power storage buffer cylinder 50, a push rod 51 and a limit assembly, wherein the oil cylinder 40 is symmetrically arranged on the top of the base 10, and the oil cylinder 40 has two, the piston rod 41 is sealed and slidably arranged inside the oil cylinder 40, and one end of the piston rod 41 is connected to the push seat 20 They are connected so that the movement of the piston rod 41 can drive the push seat 20 to move, the oil return cylinder 43 is arranged inside the oil cylinder 40 along the axial direction, a piston chamber 2 42 is opened inside the piston rod 41, and the oil return cylinder 43 and the piston chamber 2 42 in the piston rod 41 are sealed and slidably matched, the force storage buffer cylinder 50 is elastically arranged inside the piston chamber 2 42, the force storage buffer cylinder 50 is used for buffering when the piston rod 41 collides, the limit assembly is arranged inside the piston chamber 2 42, and the limit assembly can store energy for the buffering force of the collision, and the push rod 51 is slidably arranged inside the force storage buffer cylinder 50, and the push rod 51 can release the limit of the limit assembly.

[0024] When the model is subjected to high-speed injection molding, the oil cylinder 40 enters the oil cylinder 40 to drive the piston rod 41 to move, the movement of the piston rod 41 drives the push seat 20 to move, and the movement of the push seat 20 drives the extrusion rod to move in the injection cylinder 30, so that the extrusion rod squeezes the plastic liquid required for injection molding into the mold, and at the same time, when the piston rod 41 moves, the return oil cylinder 43 will be inserted into the interior of the piston chamber 42, and when the top end of the return oil cylinder 43 is pressed against the storage buffer cylinder 50 in the piston chamber 42, the extrusion rod squeezes all the plastic liquid into the mold, and at the same time, the storage buffer cylinder 50 can The oil cylinder 43 is elastically supported to avoid violent collision between the piston rod 41 and the oil return cylinder 43, thereby increasing the service life of the internal seal of the oil cylinder 40. At the same time, the limiting assembly limits the buffer force of the force storage buffer cylinder 50. When the oil return cylinder 43 returns oil to drive the piston rod 41 to move in the opposite direction, the oil pressure will first impact the push rod 51 to cause the push rod 51 to move. The movement of the push rod 51 drives the limiting assembly to release the limit of the force storage buffer cylinder 50, so that the force storage buffer cylinder 50 forms a reverse thrust to move the oil return cylinder 43 away from the piston rod 41, thereby further improving the injection molding efficiency of the injection molding device.

[0025] To further explain how to avoid reducing the service life of the internal seal of the oil cylinder 40 during high-speed injection molding and improve the injection molding efficiency, a detailed description will be given below.

[0026] like Figures 2 to 5 As shown, the oil cylinder 40 is symmetrically arranged on the top of the base 10, and a piston chamber 44 is opened inside the oil cylinder 40, and the piston chamber 44 is opened along the axial direction of the oil cylinder 40, and in this embodiment, there are two oil cylinders 40, so that the top push extrusion rod is more stable, and sufficient power can be achieved for high-speed extrusion. The piston rod 41 is slidingly sealed and arranged inside the piston chamber 44, and the piston rod 41 is composed of a disc and a cross bar, the outer circumferential surface of the disc is against the inner annular surface of the piston chamber 44, and the right end of the cross bar extends out The outside of the oil cylinder 40 and the right end of the cross bar are connected to the outer wall of one side of the push seat 20, so that the left and right movement of the piston rod 41 can drive the push seat 20 to move. An oil inlet hole 45 is provided on the top of the oil cylinder 40, and the oil inlet hole 45 is connected to an external oil pumping device so that the oil pumping device can pump hydraulic oil into the oil inlet hole 45. The hydraulic oil pushes the piston rod 41 to move to the left through the oil inlet hole 45. The movement of the piston rod 41 drives the push seat 20 to move, so that the push seat 20 pushes the extrusion rod for extrusion injection molding.

[0027] like Figure 4 As shown, the oil return cylinder 43 is arranged inside the piston cavity 44 along the axial direction, and an oil return cavity 46 is opened inside the oil return cylinder 43. The internal space of the oil return cavity 46 is smaller than the space inside the piston cavity 44. Therefore, when the oil return is performed to drive the piston rod 41 to move in the opposite direction, the oil return through the oil return cavity 46 can improve the efficiency of the entire oil return, and enable the piston rod 41 to be pushed and moved at a high speed to achieve high-speed injection molding.

[0028] like Figures 4 to 6 As shown, there is an elastic member 53 at the right end of the piston chamber 42, a baffle 52 is provided on the side wall of one end of the force storage buffer cylinder 50, and one end of the elastic member 53 is fixedly connected to the baffle 52, and the other end of the elastic member 53 is connected to the inner wall of the right end of the piston chamber 42, so that the force storage buffer cylinder 50 is elastically arranged at the right end of the piston chamber 42, a slideway is axially opened inside the force storage buffer cylinder 50, and the push rod 51 is slidably arranged on the slideway inside the force storage buffer cylinder 50.

[0029] like Figure 5 to Figure 6 As shown, the limiting assembly includes: a limiting rod 60, a limiting groove 61, a U-shaped air channel 62, a first T-type valve 63, a second T-type valve 64 and a third extension rod 66. The force storage buffer cylinder 50 is in the shape of a rectangular column. The limiting rod 60 is elastically arranged on two opposite side walls of the force storage buffer cylinder 50. A concave cavity 70 is opened inside the piston rod 41. The U-shaped air channel 62 is opened on the opposite side walls of the concave cavity 70, and the openings of the U-shaped air channel 62 are all facing the concave cavity 70 and connected with the concave cavity 70. The internal sliding seal of the U-shaped air channel 62 is provided with a first T-type valve 63 and a second T-type valve 64, and the first T-type valve 63 and the second T-type valve 64 correspond to an opening respectively, and the first T-type valve 63 is elastically arranged inside the U-shaped air channel 62, the bottom end of the first T-type valve 63 extends to the opening of the U-shaped air channel 62, and the bottom end of the second T-type valve 64 is located above the limiting groove 61.

[0030] A support plate 65 is provided on the right end face of the power storage buffer cylinder 50, and a third extension rod 66 is elastically provided on the support plate 65, and the third extension rod 66 is perpendicular to the support plate 65, the bottom end of the third extension rod 66 extends out of the support plate 65, and the bottom end of the third extension rod 66 is provided with an inclined surface 67, the right end of the push rod 51 extends to the interior of the concave cavity 70, and an elastic member 2 71 is provided inside the concave cavity 70, the elastic member 2 71 is connected to the right end of the push rod 51, so that the elastic member 2 71 elastically supports the push rod 51, and the diameter of the push rod 51 is smaller than the diameter of the oil return chamber 46, so that the push rod 51 can be inserted into the interior of the oil return chamber 46, and the outer wall of the push rod 51 is symmetrically provided with fixing rods 72.

[0031] When the piston rod 41 moves inside the piston chamber 1 44, the oil return cylinder 43 is inserted into the piston chamber 2 42. When the oil return cylinder 43 moves to the bottom end of the piston chamber 2 42, the end of the oil return cylinder 43 will push the force storage buffer cylinder 50, thereby buffering the oil return cylinder 43, thereby avoiding the collision between the oil return cylinder 43 and the piston chamber 2 42 during high-speed injection molding, thereby avoiding damage to the seal inside the oil cylinder 40. When the force storage buffer cylinder 50 moves to the right after being pushed, the force storage buffer cylinder 50 drives the limit rod 60 to move. When the limit rod 60 moves to the bottom of the limit groove 61, due to the elastic setting of the limit rod 60, the limit rod 60 will be stuck in the limit groove 61.

[0032] When returning oil, the hydraulic oil will return oil from left to right through the return oil chamber 46 inside the return oil cylinder 43. When the high-speed hydraulic oil moves to the right end of the return oil cylinder 43, it will first push the push rod 51. The movement of the push rod 51 drives the fixed rod 72 to move. The fixed rod 72 moves to push the inclined surface 67 on the bottom end of the third extension rod 66, so that the third extension rod 66 moves upward. The upward movement of the third extension rod 66 drives the first T-type valve 63 to move upward, so that the first T-type valve 63 squeezes the U-shaped air passage 62. The gas in the part pushes the second T-type valve 64 to move downward, and the second T-type valve 64 moves downward to squeeze the limit rod 60 to move downward, so that the limit rod 60 leaves the limit groove 61, thereby realizing the release of the limit of the force storage buffer cylinder 50, so that the elastic member 53 pushes the force storage buffer cylinder 50 to the left, so that the force storage buffer cylinder 50 pushes the oil return cylinder 43, thereby converting the buffering force into impact force, and pushing the oil return cylinder 43 at the moment of oil return, thereby improving the working efficiency of the oil cylinder 40, thereby realizing high-speed extrusion.

[0033] When resetting, the first T-type valve 63 will reset downward due to its elastic setting. A connecting piece is provided between the first T-type valve 63 and the second T-type valve 64. In this embodiment, the connecting piece is a wire rope. Therefore, the downward movement of the first T-type valve 63 drives the second T-type valve 64 to move upward, so that the first T-type valve 63 and the second T-type valve 64 are reset.

[0034] It should be noted that the limiting assembly is symmetrically arranged on the opposite side walls of the cavity 70, so as to ensure stable limiting or releasing of the force storage buffer cylinder 50, so that the force storage buffer cylinder 50 can buffer the seal inside the oil cylinder 40 while ensuring the performance of the oil cylinder 40.

[0035] like Figures 1 to 3As shown, a Laval tube 48 is provided on the side wall of one end of the oil cylinder 40, and one end of the Laval tube 48 is connected to the return oil pump, and the other end of the Laval tube 48 is connected to the left end of the return oil cylinder 43, so that the return oil first passes through the Laval tube 48 and then enters the interior of the return oil cylinder 43. The hydraulic oil can increase the flow rate through the Laval tube 48, so that the hydraulic oil can better collide with the push rod 51, thereby ensuring the stable pushing of the limit assembly, and the Laval tube 48 is a prior art and is not described in detail.

[0036] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A glue injection device for an injection molding machine, characterized in that: include: Base (10); A push seat (20) is slidably disposed on the base (10); an injection molding cylinder (30) is disposed on the base (10); an extrusion rod is disposed inside the injection molding cylinder (30); and a side wall of the push seat (20) is connected to one end of the extrusion rod; A plurality of oil cylinders (40) are arranged on the base (10), a piston rod (41) is provided inside the oil cylinder (40) in a sealing and slidable manner, one end of the piston rod (41) is connected to the push seat (20), so that the movement of the piston rod (41) can drive the push seat (20) to move, an oil return cylinder (43) is provided inside the oil cylinder (40) along the axial direction, a second piston chamber (42) is provided inside the piston rod (41), and the oil return cylinder (43) and the second piston chamber (42) in the piston rod (41) are sealingly slidably matched; A force storage buffer cylinder (50) is elastically arranged inside the second piston chamber (42), and the force storage buffer cylinder (50) is used to buffer and store force when the piston rod (41) collides with the oil return cylinder (43); The limiting assembly is arranged inside the second piston chamber (42), and the limiting assembly can limit the buffer force of the collision between the power storage buffer cylinder (50) and the oil return cylinder (43). A push rod (51) is slidably arranged inside the power storage buffer cylinder (50), and the return oil of the oil return cylinder (43) can drive the push rod (51) to move so that the limiting assembly releases the limit on the power storage buffer cylinder (50).

2. The injection molding device of an injection molding machine according to claim 1, characterized in that: The oil cylinder (40) is provided with a piston chamber (44) in the interior thereof, and the piston chamber (44) is provided along the axial direction of the oil cylinder (40). A piston rod (41) is slidingly sealed and arranged in the interior of the piston chamber (44). The piston rod (41) is composed of a disc and a cross bar. The right end of the cross bar extends out of the oil cylinder (40), and the right end of the cross bar is connected to an outer wall of one side of the push seat (20). An oil inlet hole (45) is provided at the top of the oil cylinder (40), and the oil inlet hole (45) is connected to an external oil pump device.

3. The injection device of an injection molding machine according to claim 2, characterized in that: The oil return cylinder (43) is arranged inside the piston chamber one (44) along the axial direction, and an oil return chamber (46) is provided inside the oil return cylinder (43), wherein the internal space of the oil return chamber (46) is smaller than the space inside the piston chamber one (44).

4. The injection device of an injection molding machine according to claim 3, characterized in that: An elastic member 1 (53) is arranged inside the second piston chamber (42), a baffle (52) is arranged on the side wall of one end of the force storage buffer cylinder (50), one end of the elastic member 1 (53) is fixedly connected to the baffle (52), and the other end of the elastic member 1 (53) is connected to the inner wall of the right end of the second piston chamber (42), so that the force storage buffer cylinder (50) is elastically arranged at the right end of the second piston chamber (42), a slideway is axially opened inside the force storage buffer cylinder (50), and the push rod (51) is slidably arranged on the slideway inside the force storage buffer cylinder (50).

5. The injection device of an injection molding machine according to claim 4, characterized in that: The limiting assembly comprises: a limiting rod (60), a limiting groove (61), a U-shaped air channel (62), a first T-shaped valve (63), a second T-shaped valve (64) and a third extension rod (66); the limiting rod (60) is elastically arranged on two opposite side walls of the power storage buffer cylinder (50); a concave cavity (70) is provided inside the piston rod (41); the U-shaped air channel (62) is provided on the opposite side walls of the concave cavity (70); and the openings of the U-shaped air channel (62) are all oriented toward the concave cavity (70) and are in communication with the concave cavity (70).

6. The injection device of an injection molding machine according to claim 5, characterized in that: The internal sliding seal of the U-shaped air channel (62) is provided with a first T-shaped valve (63) and a second T-shaped valve (64), and the first T-shaped valve (63) and the second T-shaped valve (64) respectively correspond to an opening, and the first T-shaped valve (63) is elastically arranged inside the U-shaped air channel (62), the bottom end of the first T-shaped valve (63) extends to the opening of the U-shaped air channel (62), and the bottom end of the second T-shaped valve (64) is located above the limiting groove (61).

7. The injection device of an injection molding machine according to claim 6, characterized in that: The right end surface of the power storage buffer cylinder (50) is provided with a support plate (65), and a third extension rod (66) is elastically provided on the support plate (65), and the third extension rod (66) is perpendicular to the support plate (65). The bottom end of the third extension rod (66) extends out of the support plate (65), and the bottom end of the third extension rod (66) is provided with an inclined surface (67). The right end of the push rod (51) extends to the inside of the concave cavity (70), and the inside of the concave cavity (70) is provided with a second elastic member (71), and the second elastic member (71) is connected to the right end of the push rod (51), so that the second elastic member (71) elastically supports the push rod (51), and the diameter of the push rod (51) is smaller than the diameter of the oil return cavity (46), so that the push rod (51) can be inserted into the inside of the oil return cavity (46), and the outer wall of the push rod (51) is symmetrically provided with fixing rods (72).

8. The injection device of an injection molding machine according to claim 7, characterized in that: A Laval tube (48) is provided on a side wall at one end of the oil cylinder (40), one end of the Laval tube (48) is connected to the oil return pump, and the other end of the Laval tube (48) is connected to the left end of the oil return cylinder (43).

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