A shot molding device for an injection molding machine

Abstract

The invention relates to the technical field of injection molding and glue injection device, and specifically discloses a glue injection device of an injection molding machine, comprising: a base; a push seat slidably arranged on the base, an injection molding cylinder is arranged on the base, and an extrusion rod is arranged inside the injection molding cylinder; a plurality of oil cylinders are arranged on the base, a piston rod is sealingly and slidably arranged inside the oil cylinder, one end of the piston rod is connected to the push seat, an oil return cylinder is arranged inside the oil cylinder along the axial direction, a piston chamber 2 is opened inside the piston rod, and the oil return cylinder and the piston chamber 2 in the piston rod are sealed and slidably matched; a force storage buffer cylinder is elastically arranged inside the piston chamber 2; a limit assembly is arranged inside the piston chamber 2, and a push rod is slidably arranged inside the force storage buffer cylinder; the glue injection device of an injection molding machine of the invention converts the buffer force into an impact force, and pushes the oil return cylinder at the moment of oil return, so as to realize high-speed extrusion and ensure the service life of the oil cylinder at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molding and injection devices, and particularly relates to an injection device for an injection molding machine. Background Art

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

[0003] In the Chinese patent with the publication number CN117885308B, an injection control device, an injection system of an injection molding machine, and an injection molding machine are disclosed, including that the injection control device drives the injection push rod by driving the first piston to move through an oil pump and driving the second piston to move, and the hydraulic oil in the fourth cavity is driven by the second piston to enter the injection drive oil circuit and drive the injection push rod, and the material is injected into the mold by the injection push rod. Since the piston area of the second piston is larger than that of the first piston, therefore, hydraulic oil can be injected into the first cavity according to the working power of the original oil pump, and the amount of hydraulic oil pressed into the injection drive oil circuit in the fourth cavity is larger than the amount of hydraulic oil in the first cavity. Thus, the purpose of rapid injection can be achieved, and the working power of the original oil pump motor set remains unchanged or becomes smaller, maintaining the same power consumption as before, without increasing the processing cost.

[0004] The above patent document can achieve the purpose of rapid injection by the fact that the amount of hydraulic oil pressed into the injection drive oil circuit in the fourth cavity is larger than the amount of hydraulic oil in the first cavity. The existing injection device realizes injection by pushing the screw with an oil cylinder. However, in order to achieve high-speed injection, the existing injection device is likely to damage the seals or moving components inside the oil cylinder, reducing the service life of the oil cylinder. Therefore, it is difficult to ensure both high-speed injection of the oil cylinder and its service life. Summary of the Invention

[0005] The present invention provides an injection device for an injection molding machine, aiming to solve the problem that high-speed injection in related technologies is likely to damage the seals or moving components inside the oil cylinder, reducing the service life of the oil cylinder, and it is difficult to ensure both high-speed injection of the oil cylinder and its service life.

[0006] An injection device for an injection molding machine according to the present invention includes:

[0007] A base;

[0008] The pushing seat is slidably arranged on the base. An injection barrel is arranged on the base. An extrusion rod is arranged inside the injection barrel, and one side wall of the pushing seat is connected to one end of the extrusion rod.

[0009] A plurality of oil cylinders are arranged on the base. A piston rod is hermetically and slidably arranged inside the oil cylinder. One end of the piston rod is connected to the pushing seat, so that the movement of the piston rod can drive the movement of the pushing seat. An oil return cylinder is arranged inside the oil cylinder along the axial direction. A second piston cavity is formed inside the piston rod, and the oil return cylinder is hermetically and slidably matched with the second piston cavity inside the piston rod.

[0010] The energy storage and buffer cylinder is elastically arranged inside the second piston cavity. The energy storage and buffer cylinder is used for buffering and storing energy when the piston rod collides with the oil return cylinder.

[0011] The limiting component is arranged inside the second piston cavity, and the limiting component can limit the buffering force of the collision between the energy storage and buffer cylinder and the oil return cylinder. A push rod is slidably arranged inside the energy storage and buffer cylinder. The oil return of the oil return cylinder can drive the movement of the push rod so that the limiting component releases the limit on the energy storage and buffer cylinder.

[0012] Preferably, a first piston cavity is formed inside the oil cylinder, and the first piston cavity is arranged along the axial direction of the oil cylinder. The piston rod is slidably and hermetically arranged inside the first piston cavity. 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 pushing seat. An oil inlet hole is arranged at the top of the oil cylinder, and the oil inlet hole is connected to an external oil pumping device.

[0013] Preferably, the oil return cylinder is arranged inside the first piston cavity along the axial direction, and an oil return cavity is formed inside the oil return cylinder. The internal space of the oil return cavity is smaller than the internal space of the first piston cavity.

[0014] Preferably, a first elastic member is arranged inside the second piston cavity. A baffle is arranged on one side wall of one end of the energy storage and buffer cylinder, and one end of the first elastic member is fixedly connected to the baffle. The other end of the first elastic member is connected to the inner wall of the right end of the second piston cavity, so that the energy storage and buffer cylinder is elastically arranged at the right end of the second piston cavity. A slide way is axially formed inside the energy storage and buffer cylinder, and the push rod is slidably arranged in the slide way inside the energy storage and buffer cylinder.

[0015] Preferably, the limiting component includes: a limiting rod, a limiting groove, a U-shaped air duct, a first T-shaped valve, a second T-shaped valve and a third push rod. The limiting rod is elastically arranged on two opposite side walls of the energy storage and buffer cylinder. A concave cavity is formed inside the piston rod. The U-shaped air duct is arranged on the opposite side walls of the concave cavity, and the openings of the U-shaped air duct all face the concave cavity and are communicated with the concave cavity.

[0016] Preferably, a first T-shaped valve and a second T-shaped valve are slidably and sealingly arranged inside the U-shaped air duct, and the first T-shaped valve and the second T-shaped valve respectively correspond to an opening. The first T-shaped valve is elastically arranged inside the U-shaped air duct, and the bottom end of the first T-shaped valve extends out of the opening of the U-shaped air duct, and the bottom end of the second T-shaped valve is located above the limiting groove.

[0017] Preferably, a support plate is arranged on the right end face of the energy storage and buffer cylinder, and a third ejecting rod is elastically arranged on the support plate. The third ejecting rod is perpendicular to the support plate. The bottom end of the third ejecting rod extends out of the support plate, and an inclined surface is arranged at the bottom end of the third ejecting rod. The right end of the ejector rod extends into the cavity, and an elastic member II is arranged inside the cavity. The elastic member II is connected to the right end of the ejector rod to elastically support the ejector rod by the elastic member II. The diameter of the ejector rod is smaller than the diameter of the oil return cavity, so that the ejector rod can be inserted into the oil return cavity. Fixed rods are symmetrically arranged on the outer wall of the ejector rod.

[0018] Preferably, a Laval tube is arranged on the side wall of one end of the oil cylinder, one end of the Laval tube is connected to the oil return pump, and the other end of the Laval tube is communicated with the left end of the oil return cylinder.

[0019] The beneficial effects of the present invention are as follows:

[0020] When high-speed injection molding is carried out on the mold, the oil cylinder is filled with oil to drive the piston rod to move. The movement of the piston rod drives the top push seat to move, and the movement of the top push seat drives the extrusion rod to move in the injection barrel, so that the extrusion rod extrudes the plastic liquid required for injection molding into the mold. At the same time, when the piston rod moves, the oil return cylinder will be inserted into the second piston cavity. When the top of the oil return cylinder abuts against the energy storage and buffer cylinder inside the second piston cavity, at this time, the extrusion rod extrudes all the plastic liquid into the mold. At the same time, the energy storage and buffer cylinder can elastically support the oil return cylinder to avoid violent collision between the piston rod and the oil return cylinder, improve the service life of the internal seal of the oil cylinder. At the same time, the limiting component limits the buffering force of the energy storage and buffer cylinder. When the oil return cylinder returns oil to drive the piston rod to move in the opposite direction, the oil pressure will first impact the ejector rod to cause the ejector rod to move. The movement of the ejector rod drives the limiting component to release the limit on the energy storage and buffer cylinder, so that the energy storage and buffer cylinder forms a reaction force to push the oil return cylinder away from the piston rod, thereby further improving the injection molding efficiency of the injection molding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the overall structural schematic diagram of the present invention.

[0022] Figure 2 is the structural schematic diagram of the injection barrel of the present invention.

[0023] Figure 3 is the structural schematic diagram of the oil cylinder of the present invention.

[0024] Figure 4 is the structural schematic diagram of the piston rod of the present invention.

[0025] Figure 5 is the enlarged view of part A in the present invention Figure 4 in the present invention

[0026] Figure 6 is the schematic diagram of the U-shaped air passage structure of the present invention

[0027] Reference numerals:

[0028] 10, base; 20, pushing seat; 30, injection barrel; 40, oil cylinder; 41, piston rod; 42, second piston chamber; 43, oil return barrel; 44, first piston chamber; 45, oil inlet hole; 46, oil return chamber; 48, Laval tube; 50, energy storage buffer barrel; 51, ejector rod; 52, baffle; 53, first elastic member; 60, limiting rod; 61, limiting groove; 62, U-shaped air passage; 63, first T-shaped valve; 64, second T-shaped valve; 65, support plate; 66, third ejecting rod; 67, inclined surface; 70, concave cavity; 71, second elastic member; 72, fixing rod Detailed implementation manners

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention

[0030] As Figures 1 to 6 shown, an injection device of an injection molding machine of the present invention includes a base 10, an injection barrel 30 and a pushing seat 20. The pushing seat 20 is slidably arranged on the top of the base 10. The injection barrel 30 is arranged along the length direction of the base 10. An extrusion rod is arranged inside the injection barrel 30, and the pushing seat 20 can drive the extrusion rod to move back and forth. The injection device further includes: an oil cylinder 40, a piston rod 41, an oil return barrel 43, an energy storage buffer barrel 50, an ejector rod 51 and a limiting component. The oil cylinders 40 are symmetrically arranged on the top of the base 10, and there are two oil cylinders 40. The piston rod 41 is hermetically and slidably arranged inside the oil cylinder 40. One end of the piston rod 41 is connected to the pushing seat 20 so that the movement of the piston rod 41 can drive the movement of the pushing seat 20. The oil return barrel 43 is arranged axially inside the oil cylinder 40. A second piston chamber 42 is formed inside the piston rod 41, and the oil return barrel 43 is hermetically and slidably engaged with the second piston chamber 42 inside the piston rod 41. The energy storage buffer barrel 50 is elastically arranged inside the second piston chamber 42. The energy storage buffer barrel 50 is used for buffering when the piston rod 41 collides. The limiting component is arranged inside the second piston chamber 42, and the limiting component can store the buffering force of the collision. The ejector rod 51 is slidably arranged inside the energy storage buffer barrel 50, and the ejector rod 51 can release the limit on the limiting component

[0031] When the model is subjected to high-speed injection molding, the oil cylinder 40 is filled with oil to drive the piston rod 41 to move. The movement of the piston rod 41 drives the pushing seat 20 to move, and the movement of the pushing seat 20 drives the extrusion rod to move within the injection barrel 30, so that the extrusion rod extrudes the plastic liquid required for injection molding into the mold. At the same time, when the piston rod 41 moves, the oil return cylinder 43 will be inserted into the interior of the second piston chamber 42. When the top of the oil return cylinder 43 abuts against the energy storage buffer cylinder 50 inside the second piston chamber 42, at this time, the extrusion rod extrudes all the plastic liquid into the mold. At the same time, the energy storage buffer cylinder 50 can elastically support the oil return cylinder 43, avoiding violent collision between the piston rod 41 and the oil return cylinder 43, improving the service life of the seals inside the oil cylinder 40. At the same time, the limit assembly limits the buffering force of the energy 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 ejector rod 51 to cause the ejector rod 51 to move. The movement of the ejector rod 51 drives the limit assembly to release the limit on the energy storage buffer cylinder 50, so that the energy storage buffer cylinder 50 forms a counter-thrust to push the oil return cylinder 43 away from the piston rod 41, thereby further improving the injection molding efficiency of the injection molding device.

[0032] To further illustrate how to avoid reducing the service life of the seals inside the oil cylinder 40 during high-speed injection molding and improve the injection molding efficiency at the same time, the following will be described in detail.

[0033] As Figures 2 to 5 shown, the oil cylinders 40 are symmetrically arranged on the top of the base 10, and a first piston chamber 44 is opened inside the oil cylinder 40. The first piston chamber 44 is opened along the axial direction of the oil cylinder 40. In this embodiment, there are two oil cylinders 40 to make the extrusion rod more stable when being pushed, and at the same time, sufficient power can be achieved for high-speed extrusion. The piston rod 41 is slidably and sealingly arranged inside the first piston chamber 44, and the piston rod 41 is composed of a disc and a cross bar. The outer peripheral surface of the disc abuts against the inner ring surface of the first piston chamber 44. The right end of the cross bar extends outside the oil cylinder 40, and the right end of the cross bar is connected to the outer wall of one side of the pushing seat 20, so that the left and right movement of the piston rod 41 can drive the pushing seat 20 to move. An oil inlet hole 45 is arranged at 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 is pushed through the oil inlet hole 45 to move the piston rod 41 to the left. The movement of the piston rod 41 drives the pushing seat 20 to move, so that the pushing seat 20 pushes the extrusion rod to perform injection molding.

[0034] As Figure 4 shown, the oil return cylinder 43 is arranged inside the first piston chamber 44 along the axial direction, and an oil return chamber 46 is opened inside the oil return cylinder 43. The internal space of the oil return chamber 46 is smaller than the internal space of the first piston chamber 44. Thus, when returning oil to drive the piston rod 41 to move in the opposite direction, returning oil through the oil return chamber 46 can improve the efficiency of the entire oil return and enable high-speed pushing of the piston rod 41 to achieve high-speed injection molding.

[0035] As Figures 4 to 6 shown, there is a first elastic member 53 at the right end inside the second piston chamber 42. A baffle 52 is provided on the side wall of one end of the energy storage buffer cylinder 50, and one end of the first elastic member 53 is fixedly connected to the baffle 52. The other end of the first elastic member 53 is connected to the inner wall of the right end of the second piston chamber 42, so that the energy storage buffer cylinder 50 is elastically arranged at the right end of the second piston chamber 42. An axial slideway is opened inside the energy storage buffer cylinder 50, and the ejector rod 51 is slidably arranged in the slideway inside the energy storage buffer cylinder 50.

[0036] As Figures 5 to 6 shown, the limiting assembly includes: a limiting rod 60, a limiting groove 61, a U-shaped air passage 62, a first T-shaped valve 63, a second T-shaped valve 64 and a third ejector rod 66. The energy storage buffer cylinder 50 is in a rectangular column shape. The limiting rod 60 is elastically arranged on two opposite side walls of the energy storage buffer cylinder 50. A concave cavity 70 is opened inside the piston rod 41. The U-shaped air passage 62 is opened on the opposite side walls of the concave cavity 70, and the openings of the U-shaped air passage 62 all face the concave cavity 70 and are communicated with the concave cavity 70. A first T-shaped valve 63 and a second T-shaped valve 64 are slidably and sealingly arranged inside the U-shaped air passage 62, and the first T-shaped valve 63 and the second T-shaped valve 64 respectively correspond to one opening. The first T-shaped valve 63 is elastically arranged inside the U-shaped air passage 62. The bottom end of the first T-shaped valve 63 extends out of the opening of the U-shaped air passage 62, and the bottom end of the second T-shaped valve 64 is located above the limiting groove 61.

[0037] A support plate 65 is provided on the right end face of the energy storage buffer cylinder 50, and a third ejector rod 66 is elastically arranged on the support plate 65. The third ejector rod 66 is perpendicular to the support plate 65. The bottom end of the third ejector rod 66 extends out of the support plate 65, and an inclined surface 67 is opened at the bottom end of the third ejector rod 66. The right end of the ejector rod 51 extends into the concave cavity 70, and an elastic member 71 is arranged inside the concave cavity 70. The elastic member 71 is connected to the right end of the ejector rod 51, so that the elastic member 71 elastically supports the ejector rod 51. The diameter of the ejector rod 51 is smaller than the diameter of the oil return cavity 46, so that the ejector rod 51 can be inserted into the oil return cavity 46. Fixed rods 72 are symmetrically arranged on the outer wall of the ejector rod 51.

[0038] When the piston rod 41 moves inside the first piston chamber 44 so that the oil return cylinder 43 is inserted into the second piston chamber 42, when the oil return cylinder 43 moves to the bottom end of the second piston chamber 42, the end of the oil return cylinder 43 will push against the energy storage buffer cylinder 50, thereby buffering the oil return cylinder 43, so as to avoid the collision between the oil return cylinder 43 and the second piston chamber 42 during high-speed injection molding, and thus avoid damaging the seals inside the oil cylinder 40. When the energy storage buffer cylinder 50 moves to the right after being pushed, the energy storage buffer cylinder 50 drives the limit rod 60 to move. When the limit rod 60 moves below the limit groove 61, due to the elastic setting of the limit rod 60, the limit rod 60 will be stuck inside the limit groove 61.

[0039] When returning oil, the hydraulic oil will return from left to right through the oil return cavity 46 inside the oil return cylinder 43. When the high-speed hydraulic oil moves to the right end of the oil return cylinder 43, it will first push against the push rod 51. The movement of the push rod 51 drives the fixed rod 72 to move. The movement of the fixed rod 72 thus pushes against the inclined surface 67 at the bottom end of the third push rod 66, so that the third push rod 66 moves upward. The upward movement of the third push rod 66 drives the first T-shaped valve 63 to move upward, so that the first T-shaped valve 63 squeezes the gas inside the U-shaped air passage 62, thereby pushing the second T-shaped valve 64 downward. The downward movement of the second T-shaped valve 64 squeezes the limit rod 60 downward, so that the limit rod 60 leaves the limit groove 61, thus realizing the release of the limit on the energy storage buffer cylinder 50, so that the first elastic member 53 pushes the energy storage buffer cylinder 50 to the left, so that the energy storage buffer cylinder 50 pushes the oil return cylinder 43, thereby converting the buffering force into an impact force and pushing the oil return cylinder 43 at the moment of returning oil, improving the working efficiency of the oil cylinder 40, and thus enabling high-speed extrusion molding.

[0040] During reset, the first T-shaped valve 63 will move downward for reset due to its elastic setting. There is a connecting member between the first T-shaped valve 63 and the second T-shaped valve 64. In this embodiment, the connecting member is a steel wire rope. Therefore, the downward movement of the first T-shaped valve 63 drives the second T-shaped valve 64 to move upward, so that the first T-shaped valve 63 and the second T-shaped valve 64 are reset.

[0041] It should be noted that the limit components are symmetrically arranged on the opposite side walls of the concave cavity 70, so as to ensure stable limiting or release of the limit on the energy storage buffer cylinder 50, so that the energy storage buffer cylinder 50 can buffer the seals inside the oil cylinder 40 while ensuring the performance of the oil cylinder 40.

[0042] Such as Figures 1 to 3As shown, a Laval tube 48 is provided on one end side wall 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 communicated with the left end of the oil return cylinder 43, so that the returned oil first passes through the Laval tube 48 and then enters the interior of the oil return 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 ejector rod 51, thereby ensuring stable pushing of the limit component. And the Laval tube 48 is a prior art and will not be described in detail here.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention.

[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0045] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as a limitation of the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to 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 force storage buffer cylinder (50) and the oil return cylinder (43). A push rod (51) is slidably arranged inside the force storage buffer cylinder (50), and the oil return of the oil return cylinder (43) can drive the push rod (51) to move so that the limiting assembly releases the limit on the force storage buffer cylinder (50); The oil cylinder (40) has a piston chamber (44) formed inside, and the piston chamber (44) is formed along the axial direction of the oil cylinder (40). A piston rod (41) is slidingly sealed and arranged inside 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 outside the oil cylinder (40) and is connected to an outer wall of a side of the push seat (20). An oil inlet hole (45) is formed at the top of the oil cylinder (40). The oil inlet hole (45) is connected to an external oil pump device. An oil return cylinder (43) is formed inside the piston chamber (44) along the axial direction and has a piston rod (41) formed inside. An oil return chamber (46) is provided, wherein the internal space of the oil return chamber (46) is smaller than the internal space of the piston chamber 1 (44); an elastic member 1 (53) is provided inside the piston chamber 2 (42); a baffle (52) is provided on the side wall at one end of the force storage buffer cylinder (50); one end of the elastic member 1 (53) is fixedly connected to the baffle (52); the other end of the elastic member 1 (53) is connected to the inner wall of the right end of the piston chamber 2 (42), so that the force storage buffer cylinder (50) is elastically arranged at the right end of the piston chamber 2 (42); a slideway is axially opened inside the force storage buffer cylinder (50); and a push rod (51) is slidably arranged on the slideway inside the force storage buffer cylinder (50).

2. The injection molding device of an injection molding machine according to claim 1, 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).

3. The injection device of an injection molding machine according to claim 2, 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).

4. The injection device of an injection molding machine according to claim 3, 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).

5. The injection device of an injection molding machine according to claim 4, 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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