High dynamic response injection oil cylinder and injection molding machine thereof

Abstract

The utility model relates to a high dynamic response injection oil cylinder and an injection molding machine thereof, for the high dynamic response injection oil cylinder, the high dynamic response injection oil cylinder comprises a piston and a piston rod, and one end of the piston rod facing a rodless cavity is provided with an axially arranged oil hole; the oil hole is a blind hole; an oil supply pipe is inserted into the oil hole; the hole wall of the oil hole and the outer wall of the oil supply pipe are sealed through an inner sealing ring; hydraulic oil is injected into the oil hole through the oil supply pipe to drive the piston rod to stretch out. The axial oil hole and the built-in oil supply pipe are arranged at the end of the piston rod, hydraulic oil directly acts on the interior of the oil hole, and the initial oil filling volume of a hydraulic system is effectively reduced; compared with a traditional rodless cavity large-area oil supply mode, the structure has the advantages that the influence of oil compressibility and pipeline pressure loss is greatly reduced, and the response time of the injection oil cylinder is shorter.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine technology, and in particular to injection cylinders in injection molding machines, specifically a high dynamic response injection cylinder and an injection molding machine thereof. Background Technology

[0002] In the injection system of an injection molding machine, the injection cylinder is a key actuator for achieving precise injection of molten plastic. Traditional injection cylinder drive structures typically use a method of supplying oil to the rodless chamber to extend the piston rod, with the return oil from the rod chamber completing the motion cycle. In this structure, because the effective working area of ​​the rodless chamber is relatively large, the hydraulic system needs to provide a large oil flow rate to meet the piston rod's movement requirements. Especially under high-speed injection conditions, the system must overcome greater hydraulic resistance and inertia, leading to a prolonged piston rod extension response time.

[0003] Furthermore, high-flow-rate oil supply not only increases the load and energy consumption of the hydraulic pump, but may also further affect dynamic response performance due to factors such as oil compressibility and pipeline pressure loss. For high-precision injection molding processes, this delay may lead to a decrease in speed control accuracy during the injection stage, thereby affecting product molding quality and consistency.

[0004] While existing technologies exist to improve response speed by increasing system pressure or optimizing valve control response, these methods are often limited by the inherent structure of the rodless chamber with its large operating area. Improving response speed often comes at the cost of significantly increased energy consumption or increased system complexity. Therefore, there is an urgent need for a novel injection cylinder drive structure that, while ensuring injection force, can shorten the piston rod extension response time by optimizing the hydraulic operating area or oil supply path, while simultaneously considering energy efficiency and system reliability. Utility Model Content

[0005] To address the technical problems in the background art, this utility model discloses a high dynamic response injection cylinder and its injection molding machine.

[0006] This utility model provides a high dynamic response injection cylinder, including a piston and a piston rod, wherein an axially arranged oil hole is provided at the end of the piston rod facing the rodless cavity;

[0007] The oil hole is a blind hole;

[0008] An oil supply pipe is inserted into the oil hole;

[0009] The wall of the oil hole is sealed to the outer wall of the oil supply pipe by an inner sealing ring;

[0010] Hydraulic oil is injected into the oil hole through the oil supply pipe, driving the piston rod to extend.

[0011] Furthermore, as the piston rod retracts, the oil supply pipe inserts into the bottom of the oil hole.

[0012] Furthermore, a connecting sleeve is installed at the open end of the oil hole; the inner wall of the connecting sleeve is sealed to the outer wall of the oil supply pipe by an inner sealing ring; the inner diameter of the oil hole is larger than the inner diameter of the connecting sleeve.

[0013] Furthermore, the connecting sleeve is threadedly connected to the piston rod.

[0014] Furthermore, the connecting sleeve is composed of a limiting part, an external threaded connecting part, and an external sealing part that are connected in sequence with decreasing diameters; the piston rod is provided with an internal threaded connecting hole, an internal sealing hole, and an oil hole that are connected in sequence with decreasing diameters; the limiting part abuts against the end of the piston rod; the external threaded connecting part is threadedly connected to the internal threaded connecting hole; the external sealing part is inserted into the internal sealing hole and is sealed to the wall of the internal sealing hole by an external sealing ring.

[0015] Furthermore, the outer wall of the limiting part is also provided with external threads, and a locking nut is threadedly connected to it; the locking nut abuts against the piston.

[0016] This utility model also provides an injection molding machine, including a high dynamic response injection cylinder.

[0017] The beneficial effects of this utility model are:

[0018] 1. By setting an axial oil hole and an internal oil supply pipe at the end of the piston rod, the hydraulic oil acts directly on the inside of the oil hole, effectively reducing the initial oil filling volume of the hydraulic system. Compared with the traditional rodless chamber large-area oil supply method, this structure greatly reduces the impact of oil compressibility and pipeline pressure loss, resulting in a shorter response time of the injection cylinder.

[0019] 2. By adopting a small-diameter oil orifice for oil supply instead of the traditional rodless chamber high-flow oil supply mode, the required output oil flow rate of the hydraulic pump is significantly reduced. At the same injection speed, energy consumption is reduced while avoiding the problem of increased hydraulic resistance caused by high-flow oil supply in the traditional solution, thus achieving a synergistic improvement in energy saving and dynamic performance. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a front sectional view of the injection cylinder in this utility model;

[0022] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0023] In the diagram: 1. Piston; 2. Piston rod; 3. Oil hole; 4. Oil supply pipe; 5. Inner sealing ring; 6. Connecting sleeve; 7. Locking nut; 8. Cylinder body; 9. Front cover; 10. Rear cover; 11. Oil hole in rod chamber; 12. Oil hole in rodless chamber; 13. Outer sealing ring; 21. Internal threaded connection hole; 22. Inner sealing hole; 61. Limiting part; 62. External threaded connection part; 63. External sealing part. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0025] Example 1:

[0026] like Figure 1 As shown, and with Figure 1 For reference, this utility model discloses a high dynamic response injection cylinder, including a cylinder body 8, a piston 1, and a piston rod 2. A front cover 9 is provided at the right end of the cylinder body 8, and the right end of the piston rod 2 extends to the right from the front cover 9. A radially extending rod-side oil hole 11 is provided on the cylinder body 8, which drives the piston rod 2 to retract to the left during oil injection. A rear cover 10 is provided at the left end of the cylinder body 8, and a radially extending rodless-side oil hole 12 is provided on the rear cover 10, which drives the piston rod 2 to extend to the right during oil injection.

[0027] The left end of the piston rod 2 is provided with an axially extending oil hole 3. The oil hole 3 is a blind hole, and an oil supply pipe 4 is inserted inside it. The left end of the oil supply pipe 4 is connected to and communicates with the inner end of the rodless chamber oil hole 12.

[0028] When piston rod 2 needs to extend, hydraulic oil acts directly on the bottom of oil hole 3 through oil supply pipe 4, driving piston rod 2 to extend. The advantages of this design are: 1. By setting an axial oil hole 3 and an internal oil supply pipe 4 at the end of piston rod 2, hydraulic oil acts directly on the inside of oil hole 3, effectively reducing the initial oil filling volume of the hydraulic system; compared with the traditional rodless chamber large-area oil supply method, this structure significantly reduces the impact of oil compressibility and pipeline pressure loss, resulting in a shorter response time of the injection cylinder.

[0029] 2. By adopting a small-diameter oil orifice 3-way oil supply instead of the traditional rodless chamber high-flow oil supply mode, the required output oil flow of the hydraulic pump is significantly reduced. At the same injection speed, energy consumption is reduced while avoiding the problem of increased hydraulic resistance caused by high-flow oil supply in the traditional solution, thus achieving a synergistic improvement in energy saving and dynamic performance.

[0030] The right end of the oil supply pipe 4 is close to the bottom of the oil hole 3, so that the area between the oil supply pipe 4 and the bottom of the oil hole 3 is minimized, which can further improve the response time of the injection cylinder.

[0031] A connecting sleeve 6 is installed at the left end of the piston rod 2. The inner wall of the connecting sleeve 6 is sealed to the outer wall of the oil supply pipe 4 by an inner sealing ring 5. Figure 2 As shown, the connecting sleeve 6 consists of a limiting part 61, an externally threaded connecting part 62, and an externally sealing part 63, which are connected in sequence with decreasing diameters. The left end of the oil hole 3 is sequentially connected to an internally sealing hole 22 and an internally threaded connecting hole 21, both with increasing inner diameters. The limiting part 61 abuts against the end of the piston rod 2; the externally threaded connecting part 62 is threadedly connected to the internally threaded connecting hole 21; the externally sealing part 63 is inserted into the internally sealing hole 22 and is sealed to the hole wall of the internally sealing hole 22 by an external sealing ring 13. The design of the connecting sleeve 6 allows the inner diameter of the oil hole 3 to be designed to be larger than the inner diameter of the connecting sleeve 6, thus reducing the weight of the piston rod 2, making its extension and retraction more stable, and also reducing costs.

[0032] The outer wall of the limiting part 61 is also provided with external threads, and a locking nut 7 is threadedly connected to it; the locking nut 7 abuts against the piston 1. The locking nut 7 is used to lock the connecting sleeve 6 to prevent the connecting sleeve 6 from being misaligned due to loose threads, which would affect the performance of the injection cylinder.

[0033] Example 2:

[0034] This utility model also discloses an injection molding machine, including the high dynamic response injection cylinder in Embodiment 1.

[0035] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high dynamic response injection cylinder, comprising a piston (1) and a piston rod (2), characterized in that: The piston rod (2) has an axially arranged oil hole (3) at one end facing the rodless cavity; The oil hole (3) is a blind hole; An oil supply pipe (4) is inserted into the oil hole (3); The wall of the oil hole (3) is sealed to the outer wall of the oil supply pipe (4) by an inner sealing ring (5); Hydraulic oil is injected into the oil hole (3) through the oil supply pipe (4), driving the piston rod (2) to extend.

2. The high dynamic response injection ram as set forth in claim 1, wherein: When the piston rod (2) retracts, the oil supply pipe (4) is inserted into the bottom of the oil hole (3).

3. The high dynamic response injection ram as set forth in claim 2, wherein: A connecting sleeve (6) is installed at the open end of the oil hole (3); The inner wall of the connecting sleeve (6) and the outer wall of the oil supply pipe (4) are sealed together by an inner sealing ring (5); The inner diameter of the oil hole (3) is larger than the inner diameter of the connecting sleeve (6).

4. The high dynamic response injection ram as set forth in claim 3, wherein: The connecting sleeve (6) is threadedly connected to the piston rod (2).

5. The high dynamic response injection ram as set forth in claim 4, wherein: The connecting sleeve (6) is composed of a limiting part (61), an external threaded connecting part (62), and an external sealing part (63) that are connected in sequence and whose diameters decrease in sequence; The piston rod (2) is provided with an internal threaded connection hole (21), an internal sealing hole (22) and an oil hole (3) that are connected in sequence with decreasing diameters; The limiting part (61) abuts against the end of the piston rod (2); The external threaded connection part (62) is threadedly connected to the internal threaded connection hole (21); The outer sealing part (63) is inserted into the inner sealing hole (22) and is sealed to the inner sealing hole (22) by an outer sealing ring (13).

6. The high dynamic response injection ram as set forth in claim 5, wherein: The outer wall of the limiting part (61) is also provided with an external thread, and a locking nut (7) is threadedly connected to it; The locking nut (7) abuts against the piston (1).

7. An injection molding machine characterized by: Including the high dynamic response injection cylinder as described in any one of claims 1-6.

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