Plasticizing Power and Injection Power Synergistic High-Efficiency Injection Molding Machine

Abstract

The present invention discloses a plasticizing power and injection power collaborative high-efficiency injection molding machine, which includes a machine shell, a barrel, a screw, a pressure sensor and a power system. The power system includes a sleeve, a plasticizing driving member, a transmission member, a connecting member, a nut and an injection driving member. The transmission member is a double-headed screw with opposite thread directions. One thread section of the double-headed screw is matched with the internal thread pair of the sleeve, and the other thread section is matched with the internal thread pair of the nut, and the end of the other thread section protrudes out of the outer end of the nut. Through the joint cooperation of different rotation speeds and directions of the sleeve and the nut, the present invention drives the double-headed screw to move linearly or rotationally to drive the screw to move synchronously. Therefore, the rated power of the motor of the injection molding unit is greatly reduced compared with the existing injection molding machine. At the same time, the structure is compact, the inertia of the moving parts is small, the response is fast, the injection molding process window can be effectively expanded, and the stability and yield rate of the products can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of injection molding machines, and particularly relates to a plasticizing power and injection power collaborative high-efficiency injection molding machine. Background Art

[0002] An injection molding machine, also known as an injection molding machine or an injection machine. It is the main molding equipment for making various shaped plastic products from thermoplastic or thermosetting plastics using plastic molding dies. The injection molding machine can heat the plastic, apply high pressure to the molten plastic, and inject it to fill the mold cavity.

[0003] Therefore, the process of plastic injection mainly includes a plasticizing process, a cushioning process, and an injection process. In the plasticizing process, mainly the screw retreats backward and rotates around its own axis to push the molten material to the discharge end of the barrel; the cushioning process mainly involves retreating and releasing pressure to ensure that the molten material does not leak from the nozzle; the injection process mainly involves pushing the screw forward to extrude the molten material from the nozzle. That is to say, in the plasticizing process, the screw moves backward while rotating; in the cushioning process, the screw moves straight backward (without rotating); in the injection process, the screw moves straight forward (without rotating).

[0004] However, in the current injection molding machine equipment in the industry, during the injection process and the plasticizing process, the utilization rate of the motor is relatively low, and the power for plasticizing and the power for injection work independently of each other. When plasticizing, the plasticizing motor is basically in a high-load or even full-load working state, while at this time, the injection motor only provides a small back pressure and is basically in a no-load working state; when injecting, the injection motor is in a full-load working state, while the plasticizing motor is basically in a no-load working state. Therefore, in order to achieve the above-mentioned plastic injection, the rated power required for the selected plasticizing motor and injection motor is relatively high, so the cost of the injection molding machine is also relatively high. For this reason, some manufacturers have already thought of collaborating the plasticizing power and the injection power to jointly complete the entire injection molding process, thereby reducing the rated power of the power output and reducing the cost. However, in actual operation, it is often complex in structure, difficult to control, and unable to meet the market demand. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an improved plasticizing power and injection power collaborative high-efficiency injection molding machine.

[0006] To solve the above technical problem, the technical solution adopted by the present invention is as follows:

[0007] A plasticizing power and injection power collaborative high-efficiency injection molding machine, which includes:

[0008] A machine shell;

[0009] A barrel, which includes a cylinder body with a cavity inside and communicating with the machine housing from one end, and a nozzle located at the other end of the cylinder body, wherein a plastic raw material inlet is provided on the cylinder body;

[0010] A screw, which extends along the length direction of the barrel;

[0011] A pressure sensor;

[0012] A power system, which is used to drive the screw to rotate around its own axis and move linearly along its own length direction,

[0013] In particular, the power system includes a sleeve whose center line coincides with the axis line of the screw and is arranged in the machine housing through a rotating connecting piece, a plasticizing driving piece for driving the sleeve to rotate around its own axis line, a transmission component passing through the inside of the sleeve, a connecting component for connecting the transmission component to the end of the screw far from the extrusion end, a nut rotatably arranged in the machine housing through a rotating connecting piece and with one end protruding from the end of the machine housing far from the barrel, and an injection driving piece arranged at the outer end of the nut and driving the nut to rotate around its own axis line. Wherein the transmission component is a double-headed screw with opposite thread directions. One thread section of the double-headed screw is matched with the internal thread pair of the sleeve, and the other thread section is matched with the internal thread pair of the nut and the end of the other thread section protrudes from the outer end of the nut. Under the cooperation of the opposite rotation of the sleeve and the nut, the double-headed screw is driven to move linearly or / and rotate backward towards the outer end of the nut.

[0014] Preferably, the double-headed screw includes a first thread section matched with the sleeve and a second thread section matched with the nut. Wherein the first thread section and the second thread section are fixedly connected from one end, the axis lines of the first thread section and the second thread section are collinear and coincide with the axis line of the screw. That is to say, the first thread section and the second thread section are located on the same component.

[0015] Furthermore, the pitch of the first thread section is greater than the pitch of the second thread section, and the pitch of the first thread section is N times the pitch of the second thread section, where N≥2 and is an integer. Such a setting is applicable to injection molding machines of different models. At different pitches, different rotation speeds of the nut and the sleeve are used to adjust the motion state of the double-headed screw.

[0016] According to a specific implementation and preferred aspect of the present invention, a connecting flange connected to the plasticizing driving piece is further provided on the outer periphery of the sleeve. The power system further includes an elastic member with both ends connected between the connecting flange and the connecting component and sleeved on the outer periphery of the double-headed screw. Wherein when the connecting component rotates and retreats towards the inside of the machine housing or moves linearly towards the inside of the machine housing, the elastic member is in a compressed deformation state; when the connecting component moves towards the outside of the machine housing, the elastic member is in a restored deformation state.

[0017] Preferably, the elastic member is a spring, and both ends are fixed on the connecting cap and the flange of the sleeve, wherein the spring is arranged to be compressible and / or twistable.

[0018] Specifically, the connecting component is a fixed flange, and the inner end of the double-headed screw is fixedly connected to the end of the screw away from the injection end.

[0019] According to another specific implementation and preferred aspect of the present invention, a casing lining is detachably arranged inside the casing, and the sleeve and the nut are respectively rotatably arranged on the casing lining through rotating connectors, wherein the rotating connectors are bearings.

[0020] Preferably, the pressure sensor is arranged between the end of the casing lining away from the barrel and the end of the casing close to the injection driving member.

[0021] Specifically, the end of the casing away from the barrel forms a stepped cavity, the casing lining is inserted into the stepped cavity, and a first inner cavity and a second inner cavity matching therewith are formed inside the casing lining, wherein the diameter of the first inner cavity is larger than that of the second inner cavity, and the bearings are respectively arranged in the first inner cavity and the second inner cavity, and the sleeve and the nut are rotatably arranged relative to the casing lining.

[0022] Preferably, the plasticizing driving member includes a plasticizing gear concentrically arranged with the sleeve, a plasticizing transmission member for driving the plasticizing gear, and a plasticizing motor.

[0023] Preferably, the injection driving member includes an injection gear sleeved on the outer end of the nut and concentrically arranged with the nut, an injection transmission member for driving the injection gear, and an injection motor.

[0024] In addition, a cooling sleeve is also provided on the outer periphery of the barrel at the end of the casing, and a feeding hole communicating with the plastic raw material inlet is opened on the cooling sleeve.

[0025] Due to the implementation of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0026] The present invention drives the linear or rotational movement of the double-headed screw to drive the screw to move synchronously through the combined cooperation of different rotation speeds and directions of the sleeve and the nut. Therefore, the rated power of the motor of the injection unit is greatly reduced compared with the existing injection molding machine. At the same time, the structure is compact, the inertia of the moving parts is small, the response is fast, the injection molding process window can be effectively expanded, and the stability and yield rate of the products can be improved. Description of the Drawings

[0027] Figure 1 It is a schematic cross-sectional view of the structure of the injection molding machine of the present invention (during the plasticizing or retracting process);

[0028] Figure 2 It is a schematic cross-sectional view of the structure of the injection molding machine of the present invention (during the injection process);

[0029] Wherein: 1. Machine housing;

[0030] 2. Barrel; 20. Cylinder body; 20a. Plastic raw material inlet; 200. Cavity; 21. Nozzle;

[0031] 3. Screw;

[0032] 4. Power system; 40. Sleeve; 41. Plasticizing drive member; 410. Plasticizing gear; 42. Transmission component; 421. First thread section; 422. Second thread section; 43. Connecting component; 44. Nut; 45. Injection drive member; 450. Injection molding gear; 46. Connecting flange; 47. Elastic member (spring); z. Rotating connecting member (bearing);

[0033] 5. Pressure sensor;

[0034] 6. Inner lining of the machine housing; q1. First inner cavity; q2. Second inner cavity;

[0035] 7. Cooling sleeve; 7a. Feeding hole. Detailed implementation manners

[0036] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0037] In the description of the present application, it should be understood that the orientation or positional relationship indicated by 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. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application 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 therefore should not be construed as a limitation of the present application.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number 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 application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0039] In this application, unless otherwise clearly specified or limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it 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 it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In this application, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature in terms of horizontal height. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature in terms of horizontal height.

[0041] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0042] As Figure 1 shown, the plasticizing power and injection power collaborative high-efficiency injection molding machine of this embodiment includes a machine shell 1, a barrel 2, a screw 3, a power system 4 and a pressure sensor 5.

[0043] Specifically, the barrel 2 includes a barrel body 20 with a cavity 200 inside and communicating with the machine shell 1 from one end, and a nozzle 21 located at the other end of the barrel body 20, wherein a plastic raw material inlet 20a is provided on the barrel body 20.

[0044] The screw 3 extends along the length direction of the barrel 2 and is arranged to match the cavity 200 of the barrel body 20.

[0045] The power system 4 is used to drive the screw 3 to rotate around its own axis and move linearly along its own length direction.

[0046] In this example, the power system 4 includes a sleeve 40 whose center line coincides with the axis line of the screw 3 and is arranged in the casing 1 through a rotating connecting member z, a plasticizing driving member 41 for driving the sleeve 40 to rotate around its own axis line, a transmission member 42 passing through the inside of the sleeve 40, a connecting member 43 for connecting the transmission member 42 to the end of the screw 3 away from the extrusion end, a nut 44 rotatably arranged in the casing 1 through the rotating connecting member z and with one end protruding from the end of the casing 1 away from the barrel 2, and an injection driving member 45 arranged at the outer end of the nut 44 for driving the nut to rotate around its own axis line.

[0047] The transmission member 42 is a double-headed screw with opposite thread directions. The double-headed screw includes a first thread section 421 that mates with the internal thread pair of the sleeve 40 and a second thread section 422 that mates with the internal thread pair of the nut 44. The first thread section 421 and the second thread section 422 are fixedly connected from one end, and the axis lines of the first thread section 421 and the second thread section 422 are collinear and coincide with the axis line of the screw 3. That is to say, the first thread section 421 and the second thread section 422 are arranged on the same component.

[0048] In this example, the pitch of the first thread section 421 is 4 times the pitch of the second thread section 422. In this way, at different pitches, different rotational speeds of the nut 44 and the sleeve 40 are realized to adjust the motion state of the double-headed screw.

[0049] A connecting flange 46 connected to the plasticizing driving member 41 is also arranged on the outer periphery of the sleeve 40. The power system further includes an elastic member 47 with both ends connected between the connecting flange 46 and the connecting member 43 and sleeved on the outer periphery of the double-headed screw. When the connecting member 43 rotates and retreats towards the inside of the casing 1 or moves linearly towards the inside of the casing 1, the elastic member 47 is in a compressed deformation state; when the connecting member 43 moves towards the outside of the casing 1, the elastic member 47 is in a restored deformation state.

[0050] In this example, the elastic member 47 is a spring, and both ends are fixed on the connecting member 43 and the connecting flange 46, and the spring is arranged to be compressible and / or twistable.

[0051] Specifically, the connecting member 43 is a fixed flange, and the inner end of the double-headed screw is fixedly connected to the end of the screw 3 away from the injection end.

[0052] A casing lining 6 is detachably arranged inside the casing 1. The sleeve 40 and the nut 44 are respectively rotatably arranged on the casing lining 6 through the rotating connecting member z, and the rotating connecting member z is a bearing.

[0053] The end of the housing 1 away from the barrel 2 forms a stepped cavity. The inner lining 6 of the housing is inserted into the stepped cavity, and a first inner cavity q1 and a second inner cavity q2 that match it are formed inside the inner lining 6 of the housing. The diameter of the first inner cavity q1 is greater than that of the second inner cavity q2. Bearings are respectively arranged in the first inner cavity q1 and the second inner cavity q2. The sleeve 40 and the nut 44 are rotatably arranged relative to the inner lining 6 of the housing.

[0054] The plasticizing drive member 41 includes a plasticizing gear 410 concentrically arranged with the sleeve 40, a plasticizing transmission member (not shown in the figure but not difficult to imagine) for driving the plasticizing gear 410, and a plasticizing motor (not shown in the figure but not difficult to imagine).

[0055] In this example, the plasticizing gear 410 and the sleeve 40 are rigidly connected (fixed connection) through a connecting flange 46.

[0056] The injection drive member 45 includes an injection gear 450 sleeved on the outer end of the nut 44 and concentrically arranged with the nut 44, an injection transmission member (not shown in the figure but not difficult to imagine) for driving the injection gear 450, and an injection motor (not shown in the figure but not difficult to imagine).

[0057] The pressure sensor 5 is arranged between the end of the inner lining 6 of the housing away from the barrel 2 and the end of the housing 1 close to the injection drive member 45. Among them, the pressure sensor 5 can control the motion states of the plasticizing motor and the injection motor according to the set value.

[0058] In addition, a cooling sleeve 7 is provided on the outer periphery of the end of the housing 1 and the barrel 2. An inlet hole 7a communicating with the plastic raw material inlet 20a is opened on the cooling sleeve 7.

[0059] The implementation process of this implementation is as follows:

[0060] I. Plasticizing process:

[0061] Combined with Figure 1 As shown, the molten material is injected into the barrel 2 from the inlet hole 7a and the plastic raw material inlet 20a. The plasticizing motor drives the plasticizing gear 410 to rotate, thereby driving the sleeve 40 to rotate. At the same time, the injection motor drives the injection gear 450 to rotate, thereby driving the nut 44 to rotate. When the rotation directions of the sleeve 40 and the nut 44 are opposite and the rotation speeds are different, the acting force formed by the double-headed screw in the axial direction is zero. The acting force in the radial direction drives the outer end of the double-headed screw to retreat and rotate outward from the nut 44. That is, at this time, the double-headed screw generates a rotational motion under the synergistic action of the sleeve 40 and the nut 44, and at the same time retreats along the axis of the screw 3 (moves to the right). In this way, the molten material moves towards the front end of the barrel 2 under the reverse push of the screw 3. The spring is compressed and deformed to store pressure, and at the same time, the torsional deformation recovers to provide a part of the plasticizing torque.

[0062] II. Retraction process (its state is the same asFigure 1 Similar (the attached drawings are omitted here):

[0063] After the above plasticizing step is completed, the plasticizing motor drives the plasticizing gear 410 to rotate, thereby driving the sleeve 40 to rotate; at the same time, the injection motor drives the injection gear 450 to rotate, thereby driving the nut 44 to rotate. Under the state where the sleeve 40 and the nut 44 rotate in opposite directions and at different rotational speeds, the acting force of the double-headed screw in the radial direction is zero. Driven by the acting force formed in the axial direction, the double-headed screw moves backward along the straight line direction, that is, at this time, the double-headed screw does not rotate under the synergistic action of the sleeve 40 and the nut 44, but retreats along the axial direction (moving to the right in the figure), thereby driving the screw 3 to retreat linearly, realizing the loosening and retreating. At the same time, the spring is further compressed.

[0064] III. Injection process:

[0065] Combined with Figure 2 As shown, after the above-mentioned loosening and retreating is completed, by reversing the rotation of the injection gear 450 driven by the injection motor, the nut 44 is driven to reverse. At the same time, the plasticizing motor drives the plasticizing gear 410 to reverse, thereby driving the sleeve 40 to reverse. Under the state where the sleeve 40 and the nut 44 rotate in opposite directions and at different rotational speeds, the acting force of the double-headed screw in the radial direction is zero, and the acting forces formed in the axial direction are all to the left. The double-headed screw does not rotate under the synergistic action of the sleeve 40 and the nut 44, but moves to the left along the axial direction, thereby injecting the molten material out of the nozzle. At this time, the spring restores its deformation to provide a part of the injection pressure and is torsionally deformed to store torque.

[0066] In summary, through the common synergy of different rotational speeds and directions of the sleeve and the nut, the present invention drives the screw to move synchronously by driving the double-headed screw to move linearly or rotate, so that the rated power of the motor of the injection unit is greatly reduced compared with the existing injection molding machine. At the same time, the structure is compact, the inertia of the moving parts is small, the response is fast, the injection molding process window can be effectively expanded, and the stability and yield rate of the products can be improved.

[0067] The above has made a detailed description of the present invention, aiming to enable those skilled in this field to understand the content of the present invention and implement it. However, it should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-efficiency injection molding machine with coordinated plasticizing power and injection power, comprising: A machine shell; A barrel, which includes a barrel body with a cavity inside and communicating with the machine shell from one end, and a nozzle located at the other end of the barrel body. A plastic raw material inlet is provided on the barrel body; A screw, which extends along the length direction of the barrel; A pressure sensor; A power system for driving the screw to rotate about its own axis and move linearly along its own length direction, characterized in that: The power system includes a sleeve whose central axis coincides with the axis of the screw and is arranged in the machine shell through a rotating connecting piece, a plasticizing driving piece for driving the sleeve to rotate around its own axis, a transmission component passing through the inside of the sleeve, a connecting component for connecting the transmission component to the end of the screw away from the extrusion end, a nut rotatably arranged in the machine shell through a rotating connecting piece and with one end protruding from the end of the machine shell away from the barrel, and an injection driving piece arranged at the outer end of the nut and driving the nut to rotate around its own axis. The transmission component is a double-headed screw with opposite thread directions. The double-headed screw includes a first thread section engaged with the internal thread pair of the sleeve, and a second thread section engaged with the internal thread pair of the nut and with the end of the thread section protruding from the outer end of the nut. The central axes of the first thread section and the second thread section are collinear and coincide with the axis of the screw; the pitch of the first thread section is greater than the pitch of the second thread section, and the pitch of the first thread section is N times the pitch of the second thread section, where N≥2 and is an integer; under the coordination of the states of opposite rotation directions and different rotation speeds of the sleeve and the nut, the acting force of the double-headed screw in the radial direction is zero, and the acting force in the axial or radial direction is used to drive the double-headed screw to move linearly or / and rotate backward toward the outer end of the nut; The plasticizing driving piece includes a plasticizing gear concentrically arranged with the sleeve, a plasticizing transmission piece for driving the plasticizing gear, and a plasticizing motor.

2. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 1, wherein: An inner lining of the machine shell is detachably arranged inside the machine shell. The sleeve and the nut are respectively rotatably arranged on the inner lining of the machine shell through rotating connecting pieces, and the sleeve and the nut are rotatably arranged relative to the inner lining of the machine shell.

3. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 2, characterized in that: The rotating connecting piece is a bearing.

4. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 3, characterized in that: A stepped cavity is formed at the end of the machine shell away from the barrel. The inner lining of the machine shell is inserted into the stepped cavity, and a first inner cavity and a second inner cavity matching it are formed inside the inner lining of the machine shell. The diameter of the first inner cavity is greater than the diameter of the second inner cavity, and the bearings are respectively arranged in the first inner cavity and the second inner cavity.

5. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 1, characterized in that: A connecting flange connected to the plasticizing driving piece is also provided on the outer periphery of the sleeve. The power system further includes an elastic member with both ends connected between the connecting flange and the connecting component and sleeved on the outer periphery of the double-headed screw. When the connecting component rotates and retreats into the machine shell or moves linearly into the machine shell, the elastic member is in a compressed deformation state; when the connecting component moves out of the machine shell, the elastic member is in a state of restoring deformation.

6. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 5, characterized in that: The connecting component is a fixed flange, and the inner end of the double-headed screw is fixedly connected to the end of the screw away from the injection end.

7. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 2, characterized in that: The pressure sensor is arranged between the end of the inner lining of the machine shell away from the barrel and the end of the machine shell close to the injection driving piece.

8. The plasticizing power and injection power collaborative high-efficiency injection molding machine according to claim 1, characterized in that: The injection driving piece includes an injection gear sleeved on the outer end of the nut and concentrically arranged with the nut, an injection transmission piece for driving the injection gear, and an injection motor.

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