Injection feeding system and injection molding machine

Abstract

The invention provides an injection feeding system and an injection molding machine, and belongs to the technical field of injection molding equipment. The feeding screw rod is located in the feeding cavity, and the feeding screw rod can move relative to the feeding cavity; a fine injection cavity is formed in the feeding screw rod and is communicated with the feeding cavity; the injection driving part comprises a screw driving part and a plunger driving part, the screw driving part is in driving connection with the feeding screw, and the plunger driving part is in driving connection with the fine injection plunger; the precise injection device has the advantages that after preliminary filling is completed, if the remaining space needs to be further precisely filled, the feeding screw maintains the injection action, the precise injection plunger independently acts, a small amount of materials in the precise injection cavity are precisely supplemented into the forming cavity, and due to the fact that the driving force needed by the precise injection plunger is small and the injection amount of the precise injection plunger is more precisely controlled, the precise injection effect is achieved. Therefore, higher injection precision can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of injection molding equipment, and particularly relates to an injection feeding system and an injection molding machine. Background Art

[0002] In the fields of plastic processing, metal powder injection molding, and other manufacturing fields that require precise control of material supply, the injection feeding system is one of the key equipment for achieving efficient and high-quality molding. The traditional injection molding process usually relies on a single screw or plunger to complete the conveying and filling of materials, and the molten material is pushed into the molding cavity by driving the linear movement of the screw or plunger. However, this structure has the following technical problems: in the large-batch feeding stage, the movement of the screw or plunger needs to overcome a large frictional resistance and material viscosity, resulting in a large driving force requirement and making it difficult to achieve precise control of micro-feeding. Especially when the molding cavity is nearly filled, the traditional system is prone to product defects (such as flash, sink marks, etc.) due to overpressure or underpressure. Summary of the Invention

[0003] The object of the present invention is to address the above problems existing in the prior art and propose an injection feeding system with high-precision shot filling.

[0004] The object of the present invention can be achieved by the following technical solutions: An injection feeding system, comprising:

[0005] An injection barrel, in which a feeding cavity is provided;

[0006] A feeding screw, which is located in the feeding cavity and can move relative to the feeding cavity;

[0007] A precision injection plunger, in which a precision injection cavity is provided and is connected to the feeding cavity;

[0008] An injection driving member, which includes a screw driving member and a plunger driving member, the screw driving member is drivingly connected to the feeding screw, and the plunger driving member is drivingly connected to the precision injection plunger;

[0009] Wherein, when the feeding screw makes a linear movement in the feeding cavity, the precision injection plunger moves synchronously therewith, and the relative position between the feeding screw and the precision injection plunger remains unchanged;

[0010] After the feeding screw conveys a set amount of material into the molding cavity, the feeding screw maintains the injection action while the precision injection plunger moves in the precision injection cavity to send the material in the precision injection cavity into the molding cavity for supplementation.

[0011] In the above-mentioned injection feeding system, the precision injection cavity extends along the axial direction of the feeding screw, and a through discharge hole is provided at the screw head of the feeding screw to achieve the communication between the precision injection cavity and the feeding cavity.

[0012] In the above-mentioned injection feeding system, there are multiple discharge holes, and along the radial direction of the screw head, the multiple discharge holes are distributed in an annular manner.

[0013] In the above-mentioned injection feeding system, a check ring is arranged on the screw head, and the discharge hole is located in the annular space of the check ring.

[0014] In the above-mentioned injection feeding system, it also includes a shooting platform frame, the screw driving component is fixedly arranged on the shooting platform frame, the screw driving component includes a first driving shaft capable of moving along a linear direction, the first driving shaft is connected to the feeding screw to realize the movement of the feeding screw in a linear direction; and the plunger driving component is located on the first driving shaft.

[0015] In the above-mentioned injection feeding system, the plunger driving component includes a precision injection hydraulic chamber arranged in the first driving shaft, a second driving shaft moving along a linear direction is arranged in the precision injection hydraulic chamber, a precision injection piston is arranged in the precision injection hydraulic chamber and is fixed to the second driving shaft; the precision injection hydraulic chamber is connected to a hydraulic control system.

[0016] In the above-mentioned injection feeding system, the screw drive also includes a feeding hydraulic chamber, a feeding piston is arranged in the feeding hydraulic chamber, the first driving shaft extends into the feeding hydraulic chamber and is fixed to the feeding piston; the feeding hydraulic chamber is connected to a hydraulic control system.

[0017] In the above-mentioned injection feeding system, it also includes a feeding module, and a quantitative output cylinder is arranged between the feeding module and the injection cylinder, a quantitative output roller is rotatably arranged in the quantitative output cylinder, a quantitative output cavity is formed between the quantitative output roller and the quantitative output cylinder, and the quantitative output cavity is connected to the feeding module and the injection cylinder.

[0018] In the above-mentioned injection feeding system, the quantitative output roller has an input end and an output end, and the outer wall of the quantitative output roller is provided with at least one output recess extending in a spiral line from the input end to the output end along the axial direction of the quantitative output roller, and the spiral direction from the input end to the output end is opposite to the rotation direction of the quantitative output roller, and the quantitative output roller is also spirally provided with a counterflow recess, and the spiral direction of the counterflow recess is opposite to the spiral direction of the output recess, and the material holding capacity of the counterflow recess is smaller than the material holding capacity of the output recess.

[0019] An injection molding machine includes the above-mentioned injection feeding system.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The precision injection plunger is located inside the feeding screw, making the volume of the precision injection cavity smaller than that of the feeding cavity. Then, the amount of material ejected each time the feeding screw moves will significantly exceed the amount ejected by the precision injection plunger. When filling the molding cavity, first, the feeding screw is used for feeding, and a large amount of material is sent into the molding cavity. After the initial filling is completed, if further precise filling of the remaining space is required, the feeding screw maintains the injection action, while the precision injection plunger acts independently to accurately supplement a small amount of material in the precision injection cavity into the molding cavity. Since the driving force required for the precision injection plunger is smaller and its injection amount control is more precise, higher injection accuracy can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional structural schematic diagram of the present invention;

[0022] Figure 2 is Figure 1 the cross-sectional structural schematic diagram of

[0023] Figure 3 is Figure 2 the partial enlarged schematic diagram at A in

[0024] Figure 4 is Figure 2 the partial enlarged schematic diagram at B in

[0025] Figure 5 is Figure 2 the partial enlarged schematic diagram at C in

[0026] Figure 6 is the three-dimensional structural schematic diagram of the feeding screw;

[0027] Figure 7 is the three-dimensional structural schematic diagram of the quantitative output roller.

[0028] In the figure, 100, injection barrel; 101, feeding cavity; 102, feeding screw; 103, discharge hole; 104, check ring; 200, precision injection plunger; 201, precision injection cavity; 202, connection hole; 300, injection platform frame; 301, first drive shaft; 302, precision injection hydraulic cavity; 303, second drive shaft; 304, precision injection piston; 305, feeding hydraulic cavity; 306, feeding piston; 307, oil passage shaft; 308, injection moving plate; 309, rotation drive member; 310, screw drive wheel; 400, quantitative output barrel; 401, quantitative output roller; 402, output recess; 403, backflow recess; 404, connection shaft; 405, temporary storage cavity; 406, communication hole. Detailed Implementation Modes

[0029] The following are specific embodiments of the present invention. In combination with the accompanying drawings, the technical solutions of the present invention will be further described, but the present invention is not limited to these embodiments.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, the directional indications will also change accordingly.

[0031] As Figures 1 - 7 shown, an injection feeding system includes:

[0032] An injection cylinder 100, in which a feeding cavity 101 is provided;

[0033] A feeding screw 102, which is located in the feeding cavity 101 and can move relative to the feeding cavity 101;

[0034] A precision injection plunger 200, in which a precision injection cavity 201 is provided in the feeding screw 102 and is connected to the feeding cavity 101;

[0035] An injection driving member, which includes a screw driving member and a plunger driving member. The screw driving member is drivingly connected to the feeding screw 102, and the plunger driving member is drivingly connected to the precision injection plunger 200;

[0036] Among them, when the feeding screw 102 moves linearly in the feeding cavity 101, the precision injection plunger 200 moves synchronously, and the relative position between the feeding screw 102 and the precision injection plunger 200 remains unchanged;

[0037] After the feeding screw 102 conveys a set amount of material into the molding cavity, the feeding screw 102 maintains the injection action while the precision injection plunger 200 moves in the precision injection cavity 201 to send the material in the precision injection cavity 201 into the molding cavity for supplementation.

[0038] In this embodiment, the precision injection plunger 200 is located inside the feeding screw 102, so that the volume of the precision injection cavity 201 is smaller than the volume of the feeding cavity 101. Then, the amount of material ejected each time the feeding screw 102 moves will be significantly more than the amount ejected by the precision injection plunger 200. When filling the molding cavity, first, the feeding screw 102 is used for feeding, and a large amount of material is sent into the molding cavity. After the initial filling is completed, if further precise filling of the remaining space is required, the feeding screw 102 maintains the injection action while the precision injection plunger 200 acts alone to accurately supplement a small amount of material in the precision injection cavity 201 into the molding cavity. Since the driving force required for the precision injection plunger 200 is smaller and its injection amount control is more precise, higher injection accuracy can be achieved.

[0039] Preferably, the fine injection cavity 201 extends along the axial direction of the feeding screw 102, and a through discharge hole 103 is provided at the screw head of the feeding screw 102 to achieve the communication between the fine injection cavity 201 and the feeding cavity 101.

[0040] In this embodiment, the material enters the feeding cavity 101 from the fine injection cavity 201 through the discharge hole 103 at the screw head. This flow path reduces the resistance during material transmission and helps improve the material conveying efficiency; since the fine injection plunger 200 is located inside the feeding screw 102 and moves along its axis, it enables more precise control of the amount of material in the fine injection cavity 201, especially when fine adjustment is required, and can more accurately control the molding quality of the final product.

[0041] More preferably, the number of the discharge holes 103 is multiple, and the multiple discharge holes 103 are annularly and spacedly distributed along the radial direction of the screw head.

[0042] In this embodiment, the annular and spaced distribution of the multiple discharge holes 103 along the radial direction of the screw head helps ensure the uniform distribution of the material when it enters the feeding cavity 101 from the fine injection cavity 201. This can avoid the problem of material concentration in a certain area, resulting in uneven filling, thereby improving the quality of the final product. It also increases the total area through which the material passes, which can improve the flow speed and efficiency of the material, especially important in the case of rapid filling; moreover, the design of the multiple discharge holes 103 can balance the reaction force received by the screw head to a certain extent, helping to extend the service life of the equipment and maintain stable operation.

[0043] It is worth mentioning that along the axial direction of the screw head, a connection hole 202 is provided on the screw head, and both ends of the connection hole 202 are respectively communicated with the fine injection cavity 201 and the discharge hole 103.

[0044] More preferably, a check ring 104 is provided on the screw head, and the discharge hole 103 is located in the annular space of the check ring 104.

[0045] In this embodiment, the existence of the check ring 104 is mainly to prevent the material in the feeding cavity 101 from flowing back when the feeding screw 102 moves in the reverse direction or stops. Setting the discharge hole 103 in the annular space of the check ring 104 can also ensure that the material flowing out of the fine injection cavity 201 will not flow back into the fine injection cavity 201, ensuring that the material can only flow unidirectionally, from the fine injection cavity 201 through the discharge hole 103 into the feeding cavity 101, and then be pushed into the molding cavity.

[0046] Preferably, it further includes a shooting platform frame 300. The screw driving member is fixedly arranged on the shooting platform frame 300. The screw driving member includes a first driving shaft 301 capable of moving along a straight line direction. The first driving shaft 301 is connected to the feeding screw 102 to realize the movement of the feeding screw 102 in the straight line direction; and the plunger driving member is located on the first driving shaft 301.

[0047] In this embodiment, the shooting platform frame 300 provides structural support to ensure the stability and rigidity of the entire injection feeding system. Components such as the screw driving member and the plunger driving member are all installed on this frame. The screw driving member is fixedly arranged on the shooting platform frame 300 and is responsible for driving the feeding screw 102 to move in a straight line direction. As the output part of the screw driving member, the first driving shaft 301 is directly connected to the feeding screw 102. By driving of the first driving shaft 301, the feeding screw 102 moves back and forth in the feeding cavity 101 to realize the pushing action of the material. And the plunger driving member is located on the first driving shaft 301, which means it is not directly installed on the shooting platform frame 300 but is indirectly connected through the first driving shaft 301.

[0048] When filling the molding cavity with materials, first, the screw driving member is started. The feeding screw 102 is driven forward by the first driving shaft 301 to push a large amount of materials into the molding cavity. After the initial filling is completed, if further precise filling of the remaining space is required, the operation state of the screw driving member is maintained, and at the same time, the plunger driving member starts to work. Since the plunger driving member is located on the first driving shaft 301, it can independently fine-tune the precision injection plunger 200 relative to the screw driving member, enabling a small amount of materials to enter the feeding cavity 101 from the precision injection cavity 201 through the discharge hole 103 and finally be sent into the molding cavity to complete the precise filling.

[0049] More preferably, the plunger driving member includes a precision injection hydraulic cavity 302 arranged inside the first driving shaft 301. A second driving shaft 303 capable of moving along a straight line direction is arranged inside the precision injection hydraulic cavity 302. A precision injection piston 304 is arranged inside the precision injection hydraulic cavity 302 and is fixed to the second driving shaft 303; the precision injection hydraulic cavity 302 is communicated with a hydraulic control system.

[0050] In this embodiment, as a part of the screw driving member, the first driving shaft 301 is responsible for driving the feeding screw 102 to move in a straight line direction. A precision injection hydraulic cavity 302 is arranged inside it to accommodate hydraulic oil or other working media. A second driving shaft 303 capable of moving along a straight line direction and a precision injection piston 304 fixed thereto are arranged inside this cavity. The movement of the second driving shaft 303 is pushed by a piston installed on it, and the piston moves in response to the pressure change inside the precision injection hydraulic cavity 302.

[0051] Further preferably, the screw driving member further includes a feeding hydraulic chamber 305, in which a feeding piston 306 is arranged. The second driving shaft 303 extends into the feeding hydraulic chamber 305 and is fixed to the feeding piston 306. The feeding hydraulic chamber 305 is communicated with a hydraulic control system.

[0052] In this embodiment, a feeding oil cylinder is fixedly arranged on the injection table frame 300. The feeding hydraulic chamber 305 is located in the feeding oil cylinder. A feeding piston 306 is arranged in the feeding hydraulic chamber 305. The feeding piston 306 is fixed to the first driving shaft 301 to realize the linear driving of the first driving shaft 301. It should be noted that the precision injection hydraulic chamber 302 and the feeding hydraulic chamber 305 respectively utilize two sets of independent hydraulic control systems.

[0053] It is worth mentioning that an oil passing shaft 307 is fixedly arranged on the first driving shaft 301. The oil passing shaft 307 extends along the axial direction. The first end of the oil passing shaft 307 is communicated with the precision injection hydraulic chamber 302, and the second end of the oil passing shaft 307 extends out of the feeding oil cylinder and can slide relative to the feeding oil cylinder. In this application, it is necessary to change the hydraulic oil pressure at both ends of the precision injection piston 304 to realize the movement of the piston in the precision injection hydraulic chamber 302. Since the precision injection hydraulic chamber 302 is located in the first driving shaft 301 and the first driving shaft 301 is also hydraulically driven, one end of the first driving shaft 301 will extend into the feeding hydraulic chamber 305, and the existence of the oil passing shaft 307 can change the oil pressure at the end of the precision injection piston 304 located in the feeding hydraulic chamber 305.

[0054] Such as Figure 1 、 Figure 5 、 Figure 7 As shown in the figures, preferably, a feeding module is further included, and a quantitative output cylinder 400 is arranged between the feeding module and the injection cylinder 100. A quantitative output roller 401 is rotatably arranged in the quantitative output cylinder 400. A quantitative output chamber is formed between the quantitative output roller 401 and the quantitative output cylinder 400. The quantitative output chamber is communicated with the feeding module and the injection cylinder 100.

[0055] In this embodiment, the material is fed into the quantitative output cylinder 400 through the feeding module. The feeding module can adjust the feeding rate of the material as needed to meet different production speed requirements. When the material enters the quantitative output cylinder 400, with the rotation of the quantitative output roller 401, the material is captured and moves in the quantitative output chamber. Since the volume of the quantitative output chamber is fixed, the amount of material that can be provided to the injection cylinder 100 each time is also fixed, realizing the precise control of the material supply. Through the design of the quantitative output cylinder 400 and the quantitative output roller 401, the precise control of the amount of material supplied each time is realized, improving the quality and consistency of the molded products.

[0056] The working parameters of the feeding module and the speed of the metering output roller 401 can be adjusted according to actual production requirements, so as to flexibly adapt to different types of materials and production requirements.

[0057] Further preferably, the metering output roller 401 has an input end and an output end. At least one output recess 402 extending in a spiral shape along the axis direction of the metering output roller 401 from the input end to the output end is provided on the outer wall of the metering output roller 401. The spiral direction from the input end to the output end is opposite to the rotation direction of the metering output roller 401. And a countercurrent recess 403 is also spirally provided on the metering output roller 401. The spiral direction of the countercurrent recess 403 is opposite to the spiral direction of the output recess 402. The material capacity that the countercurrent recess 403 can accommodate is less than the material capacity that the output recess 402 can accommodate.

[0058] In this embodiment, the metering output roller 401 has a clear input end and an output end, which are respectively used to receive materials and feed the materials into the injection cylinder 100. At least one output recess 402 extending in a spiral shape along the axis direction is provided on the outer wall of the metering output roller 401. The spiral extends from the input end to the output end, and its spiral direction is opposite to the rotation direction of the metering output roller 401. The material is pushed forward more stably under the reverse thrust during rotation; the existence of the countercurrent recess 403 enables the materials exceeding the fixed output amount to flow back to the input end along the countercurrent recess 403, ensuring that the output recess 402 can output materials quantitatively.

[0059] It should be noted that the material capacity that the countercurrent recess 403 can accommodate being less than the material capacity that the output recess 402 can accommodate means that, along the spiral direction, the cross-sectional area of the countercurrent recess 403 is less than the cross-sectional area of the output recess 402.

[0060] It is worth mentioning that a connecting shaft 404 is provided at the output end of the metering output roller 401. The connecting shaft 404 is rotatably connected to the metering output cylinder 400. A gap is formed between the end face of the output end of the metering output roller 401 and the cylinder wall of the metering output cylinder 400 to form a temporary storage cavity 405. Along the radial direction of the connecting shaft 404, a communication hole 406 is provided on the connecting shaft 404 and is connected to the temporary storage cavity 405. Along the axial direction of the connecting shaft 404, a transmission hole is provided on the connecting shaft 404 and is connected to the communication hole 406 and the feeding cavity 101.

[0061] Specifically, a moving injection plate 308 is slidably arranged on the injection platform frame 300. A rotation driving member 309 is fixedly arranged on the moving injection plate 308. The output shaft of the rotation driving member 309 is connected to the input end of the metering output roller 401 through a coupling. The output shaft is a spline shaft, enabling the output shaft to drive the metering output roller 401 to rotate while being able to move linearly relative to the metering output roller 401. The output shaft and the screw driving wheel 310 are driven by a belt, so that the metering output roller 401 and the feeding screw 102 are driven by the same power source.

[0062] An injection molding machine includes the above-mentioned injection feeding system.

[0063] It should be noted that in the present invention, descriptions such as "first", "second", "one", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. 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. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0065] The specific embodiments described herein are only illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An injection feeding system, characterized in that: include: A syringe, wherein a feeding cavity is provided in the syringe; A feeding screw, the feeding screw is located in the feeding cavity and can move relative to the feeding cavity; A precision-ejection plunger, wherein a precision-ejection cavity is arranged in the feeding screw and is in communication with the feeding cavity; An injection driving member, the injection driving member comprises a screw driving member and a plunger driving member, the screw driving member is drivingly connected to the feeding screw, and the plunger driving member is drivingly connected to the precision injection plunger; Wherein, when the feeding screw moves linearly in the feeding cavity, the precision-ejection plunger moves synchronously therewith, and the relative positions of the feeding screw and the precision-ejection plunger remain unchanged; After the feeding screw delivers a set amount of material into the molding cavity, the feeding screw maintains the injection action and the precision injection plunger moves in the precision injection cavity to deliver the material in the precision injection cavity to the molding cavity for replenishment.

2. An injection feeding system according to claim 1, characterized in that: The precision injection cavity extends along the axial direction of the feeding screw, and a through discharge hole is arranged at the screw head of the feeding screw to realize the communication between the precision injection cavity and the feeding cavity.

3. An injection feeding system according to claim 2, characterized in that: There are multiple discharge holes, and along the radial direction of the screw head, the multiple discharge holes are distributed in an annular manner.

4. An injection feeding system according to claim 2, characterized in that: A check ring is arranged on the screw head, and the discharge hole is located in the annular space of the check ring.

5. The injection feeding system according to claim 1, characterized in that: It also includes a shooting platform frame, the screw driving member is fixedly arranged on the shooting platform frame, the screw driving member includes a first driving shaft that can move along a linear direction, the first driving shaft is connected to the feeding screw to realize the movement of the feeding screw in the linear direction; and the plunger driving member is located on the first driving shaft.

6. An injection feeding system according to claim 5, characterized in that: The plunger driving member includes a precision injection hydraulic chamber arranged in the first driving shaft, a second driving shaft moving along a straight line is arranged in the precision injection hydraulic chamber, a precision injection piston is arranged in the precision injection hydraulic chamber and fixed to the second driving shaft; the precision injection hydraulic chamber is connected to a hydraulic control system.

7. An injection feeding system according to claim 5, characterized in that: The screw drive also includes a feeding hydraulic chamber, in which a feeding piston is arranged, and the first driving shaft extends into the feeding hydraulic chamber and is fixed to the feeding piston; the feeding hydraulic chamber is connected to a hydraulic control system.

8. An injection feeding system according to claim 1, characterized in that: It also includes a feeding module, and a quantitative output cylinder is arranged between the feeding module and the injection cylinder, a quantitative output roller is rotatably arranged in the quantitative output cylinder, a quantitative output cavity is formed between the quantitative output roller and the quantitative output cylinder, and the quantitative output cavity is connected with the feeding module and the injection cylinder.

9. An injection feeding system according to claim 8, characterized in that: The quantitative output roller has an input end and an output end. The outer wall of the quantitative output roller is provided with at least one output recess extending in a spiral line from the input end to the output end along the axial direction of the quantitative output roller. The spiral direction from the input end to the output end is opposite to the rotation direction of the quantitative output roller. The quantitative output roller is also spirally provided with a counterflow recess. The spiral direction of the counterflow recess is opposite to the spiral direction of the output recess. The material holding capacity of the counterflow recess is smaller than the material holding capacity of the output recess.

10. An injection molding machine, characterized in that: Comprising the injection feeding system as described in any one of claims 1-9.

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