WO2018218394A1

WO2018218394A1 - High-performance electric injection molding device

Info

Publication number: WO2018218394A1
Application number: PCT/CN2017/086247
Authority: WO
Inventors: 陈明华
Original assignee: 苏州锦珂塑胶科技有限公司
Priority date: 2017-05-27
Filing date: 2017-05-27
Publication date: 2018-12-06
Also published as: CN108927966B; CN108927966A; WO2018218768A1

Abstract

A high-performance electric injection molding mechanism and an injection molding machine. The high-performance electric injection molding mechanism comprises a screw rod (1), a screw rod drive shaft (10), a ball lead-screw (12), and an axial guiding mechanism (11). The screw rod drive shaft (10) comprises a ball spline and a ball nut. In the injection molding system and the injection molding machine, when an injection action is performed, the number of components needing to make movement is small; only the screw rod (1), the screw rod drive shaft (10) and other mechanisms need to make movement, and other drive and transmission components do not make axial movement along with injection actions, the mass of the system is light during the injection actions, the movement inertia is greatly reduced, accordingly, the response speed and the precision of the injection actions are greatly improved, and the drive power is also greatly reduced.

Description

High-performance electric injection molding device

Technical field

The invention belongs to the field of plastics and relates to an electric injection molding mechanism used in an injection molding machine or the like.

Background technique

The consumption rate of the plastics industry has been increasing. Therefore, the improvement of the overall technical level of injection molding machines is crucial to enhance the competitiveness of the plastics industry.

At present, the injection molding machine mainly includes motors, reduction transmission systems, screws, screw nut pairs and other components. Among them, the screw is an important part of the injection molding machine, used for conveying, compacting, melting, stirring and pressing the plastic. The action is accomplished by the rotation of the screw within the barrel and the movement in the axial direction. When the screw rotates, the plastic will rub against each other on the inner wall of the barrel, the bottom surface of the screw groove, the screw advance surface, and between the plastic and the plastic.

The injection time is crucial for the shaping of the plastic, and it is necessary to ensure that the injection system has sufficient response speed (ie screw acceleration) to ensure that the melt can be injected into the cavity of the mold in a short time. In the conventional injection molding apparatus, the amount of components that need to be moved during the injection process is large and complicated (for example, including a screw, a servo motor, a pre-plasticized transmission system, a bearing set, an injection nut, and an injection slide seat). According to Newton's second law, when the injection pressure is constant, if the total mass of the injection motion system is large, the acceleration obtained by the screw will decrease, that is, the injection response speed is greatly reduced, and the required speed cannot be achieved in a very short time. The injection speed has a great influence on the working conditions required for high-speed injection. In addition, the linear guide of the moving parts in the conventional injection system is realized by sliding friction, and the contact surface wears quickly, the heat is high, the lubrication requirement is high, the lubrication phenomenon occurs when the lubrication is insufficient, and the power consumed by the drive motor is also increased. .

In view of this, how to design a new electric injection molding system and an injection molding machine including the same to eliminate the above-mentioned defects and deficiencies in the prior art is an urgent problem to be solved by those skilled in the art.

Summary of the invention

In order to overcome the technical problems in the prior art, the present invention provides an electric injection molding system and an injection molding machine including the same, which requires less moving parts than conventional conventional injection molding machines when performing an injection operation. The inertia is greatly reduced, and the effect speed and injection accuracy of the injection system are greatly improved.

In a first aspect of the invention, an injection molding system for an injection molding machine is provided, comprising:

a screw

a screw drive shaft, the screw drive shaft includes a ball spline and a ball nut, the screw is mounted on the screw drive shaft;

a ball screw, the ball screw being mounted in cooperation with the ball nut of the screw drive shaft, the ball screw moving the screw drive shaft and the screw back and forth in an axial direction; and

An axial guiding mechanism is mounted with the ball spline of the screw drive shaft.

Preferably, in the injection molding system, the screw and the screw drive shaft are axially moved back and forth, and the ball screw and the axial guiding mechanism do not move axially back and forth.

Preferably, the screw drive shaft is provided in one piece.

Preferably, the injection molding system further includes an elastic energy storage device and a retaining ring, wherein the retaining ring is fitted to one end of the screw drive shaft of the screw, so that the movement state of the retaining ring and the screw Similarly, one end of the elastic energy storage device is mounted on the retaining ring, and the other end is fixed.

Preferably, the elastic energy storage mechanism and the screw drive shaft are coaxially disposed.

Preferably, the inner cavity of the axial guiding mechanism and the ball spline of the screw drive shaft are mounted by ball cooperation, so that the axial guiding mechanism guides the screw drive shaft to move axially forward and backward, and also A limit of the circumferential direction of the screw drive shaft is provided.

According to a second aspect of the invention, there is provided an injection molding machine comprising the injection molding system and the mold clamping system according to the first aspect of the invention.

Compared with the prior art, the technical solution provided by the present invention has the following advantages:

1. In the injection molding system and the injection molding machine provided by the invention, the screw drive shaft comprises a ball spline and a ball nut, and is integrated, and realizes the dual functions of the ball spline and the ball nut, and provides a guiding effect while greatly reducing the guide. The coefficient of friction during the operation of the injection molding system increases the injection acceleration.

2. In the injection molding system and the injection molding machine provided by the present invention, when the injection operation is performed, there are few parts that need to be moved, and only the screw and the screw drive shaft (and the selectively arranged elastic energy storage device, including but not limited to springs) are used. The axis moves back and forth, and the motor, gear/belt drive, bearing set, ball screw, axial guide mechanism and injection slide seat remain fixed, do not move axially back and forth with the injection action, the moving part of the injection molding system The quality is very light. When the injection pressure is constant, the total mass of the injection movement system is greatly reduced, the exercise inertia is greatly reduced, and the acceleration obtained by the screw is greatly improved, so the injection is performed. The system's effect speed and injection accuracy are greatly improved.

3. The injection screw of the injection molding system of the invention is directly assembled with the screw drive shaft, and no additional installation process is required, so that the injection screw and the screw drive shaft can maintain synchronous movement, and the screw drive shaft is also designed for integral processing, and the injection molding system The stability is greatly improved.

4. The injection molding system and the injection molding machine provided by the invention are provided with an elastic energy storage device, and are connected with the tail of the injection screw, can perform back pressure compensation during the pre-plasticization process, and compress energy storage, and release elastic energy storage during the injection process. The device can directly and accurately apply the thrust to the screw to effectively increase the injection pressure and speed; and the elastic energy storage mechanism and the screw drive shaft are coaxially arranged to improve the stability of the injection molding system.

5. The application of the elastic energy storage device in the invention, the back pressure pressure compensation can be performed in the pre-plasticizing process, and the compression energy storage can effectively reduce the rated power of the injection driving motor and reduce the cost of the injection system.

DRAWINGS

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of the principle of a first embodiment of an injection molding system provided by the present invention.

2 is a top plan view showing the structure of a first embodiment of the injection molding system provided by the present invention.

3 is a top plan view of the drive/drive process of the first embodiment of the injection molding system provided by the present invention.

Best embodiment

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention should be construed as being not limited to the embodiments described below, and the technical idea of the present invention can be implemented in combination with other known techniques or other techniques having the same functions as those of the known art.

In the following description of the specific embodiments, in order to clearly illustrate the structure and the mode of operation of the present invention, it will be described by a plurality of directional words, but should be "front", "back", "left", "right", "outside" Words such as "inner", "outward", "inward", "axial", "radial" and the like are understood to be convenience words and should not be construed as limiting words.

Terminology

1. Screw drive shaft: The screw drive shaft of the present invention is integrally arranged, which refers to the ball spline and the ball nut as a whole, that is, the outer surface of the same hollow shaft is processed into a spline, and the inner cavity is processed into a ball screw. The mother, as the screw drive shaft, is axially guided by the ball nut of the inner ring and the ball screw (the screw drive shaft and the ball screw are not integrally processed) while the shaft and the drive are connected, This ensures that the direction of the driving force of the ball screw always coincides with the axis of the entire injection portion (including the screw + screw drive shaft + ball screw).

2. Axial guiding mechanism: It is matched with the ball spline part of the screw drive shaft, which is axially constrained, and provides axial and forward movement guidance.

The object of the present invention is to provide a high-performance injection molding system and an injection molding machine equipped with the injection molding system, which can reduce the load of the injection molding system during operation, improve the response speed and accuracy of the injection molding system, and reduce the driving power of the injection molding system and improve the efficiency. cut costs.

Specific embodiments of the present invention are described in detail below with reference to Figures 1-3.

The injection molding system provided by the invention comprises:

Screw 1, barrel 2, fixed frame 3, retaining ring 4, spring 5, pre-plastic motor 6, first pre-plastic gear 7, second pre-plastic gear 8, first bearing set 9, screw drive shaft 10, shaft The guide mechanism 11, the ball screw 12, the injection motor 13, the first injection gear 14, the second injection gear 15, the second bearing group 16, and the nozzle 17.

In the present specification, "forward" of the moving member means moving toward the nozzle 17, and "reverse" means moving in a direction away from the nozzle 17.

In the present specification, the "rear end" and "rear side" are ends that extend away from the direction of the screw.

In the present specification, the "moving back and forth in the axial direction" and "the axial movement in the front and rear direction" mean moving back and forth with respect to the fixed frame.

In an embodiment of the invention, a preferred pre-molding drive mechanism comprises a pre-plastic motor 6, a first pre-plastic gear 7 and a second pre-plastic gear 8, it being noted that one skilled in the art may take other An alternative drive to accomplish the function of the pre-drive drive mechanism includes, but is not limited to, a hollow shaft motor drive or the like well known to those skilled in the art.

In an embodiment of the present invention, a preferred driving mechanism during the injection process includes an injection motor 13, a first injection gear 14, and a second injection gear 15. It should be noted that those skilled in the art may adopt other alternative drives. The manner in which the function of the injection drive mechanism is accomplished includes, but is not limited to, the use of motor direct drive, and the like, which is well known to those skilled in the art.

In an embodiment of the present invention, preferably, the injection molding system includes a screw drive shaft and an axial guiding mechanism that are fitted and mounted, and is axially constrained while providing axial forward and backward movement guidance. The person can use other alternative structures to achieve the function of transmitting the rotation of the drive mechanism to the screw and moving the screw axially.

Embodiment 1:

Hereinafter, the structure of an injection molding system according to a first embodiment of the present invention will be described with reference to Figs.

Fig. 1 is a schematic view showing the principle of an injection molding system of a first embodiment of the present invention.

Fig. 2 is a plan view showing the injection molding system of the first embodiment in a cross section.

The barrel is 2 and the fixed frame is 3, and the fixed frame 3 is used to support the injection molding system. The barrel 2 is fixedly coupled to the front end of the fixed frame 3 by bolts, and a nozzle 17 is provided at the front end of the barrel 2, and a mold clamping system (not shown) may be disposed in front of the nozzle 17.

The screw 1 functions as a push-out member, and the main body of the screw 1 is fitted with the inner cavity of the cylinder 2, and the screw 1 can be moved forward and backward or along the axis of the cylinder 2.

The trailing end of the screw 1 is fixed to the front end of the screw drive shaft 10 to ensure that the movement state of the screw 1 is the same as that of the screw drive shaft 10.

The screw drive shaft 10 is an integral arrangement, including a ball spline and a ball nut, that is, the ball spline and the ball nut are processed as a whole, that is, the outer surface of the same hollow shaft is processed into a spline, and the inner cavity is processed into a ball nut. , to play the role of the shaft. The screw drive shaft 10 is fitted by the ball nut of the inner ring and the ball screw 12 while the shaft and the drive are being driven.

The ball spline of the screw drive shaft 10 is hollow near one end of the ball screw 12, and the inner cavity of the hollow portion is processed into a ball nut. The inner cavity of the ball nut is fitted with one end of the ball screw 12, and the ball screw 12 is mounted. The other end is mounted on the rear end of the fixed frame 3 through the second bearing set 16, thereby axially fixing the ball screw 12, and the ball screw 12 is rotatable about the axis.

The inner cavity of the axial guiding mechanism 11 and the ball spline of the screw drive shaft 10 are mounted by ball cooperation, so that the axial guiding mechanism 11 guides the screw driving shaft 10 in front and rear axial movement, and also performs the circumferential direction limit. .

The outer ring of the axial guiding mechanism 11 is mounted to the middle of the fixed frame 3 by the first bearing set 9, so that the axial direction of the axial guiding mechanism 11 is fixed in position, but it can be rotated along the axis.

The second injection gear 15 is coupled to the trailing end of the ball screw 12, and the rotation of the second injection gear 15 drives the ball screw 12 to rotate, and drives the ball nut of the screw drive shaft 10 to move axially, thereby driving the screw 1 to move back and forth.

The retaining ring 4 is mounted at the rear end of the screw 1 (i.e., the moving state of the retaining ring 4 is the same as that of the screw 1), and one end of the spring 5 is fixed to the end surface of the retaining ring 4, and the other end is fixed to the end surface of the second pre-plastic gear 8.

The pre-molded motor 6 is fixed on the fixed frame 3, the first pre-plastic gear 7 is mounted on the shaft of the pre-plastic motor 6, and the second pre-molded gear 8 is fixedly coupled to the end surface of the axial guiding mechanism 11, the first pre-plastic gear 7 and the second pre-plastic gear 8 are directly meshed or driven by a belt (or a chain or the like).

The injection motor 13 is fixed to the fixed frame 3, and the first injection gear 14 is mounted on the shaft of the injection motor 13, and is directly meshed with the second injection gear 15 or driven by a belt (or a chain or the like).

The pre-molding motor 6 and the injection motor 13 cause the screw 1 to complete rotation or axial back and forth movement.

Hereinafter, an operation of the injection molding apparatus according to the first embodiment of the present invention will be described with reference to Figs.

1. Pre-plastic stage:

The pre-molding motor 6 is powered, transmitted to the second pre-plastic gear 8 through the first pre-plastic gear 7, and the second pre-molding gear 8 drives the axial guiding mechanism 11 to rotate, thereby driving the shaft 10 through the axial guiding mechanism 11 and the screw. The ball spline cooperates to drive the screw drive shaft 10 to rotate about the axis, and the drive screw 1 rotates to perform a pre-plastic action.

In the pre-molding process, the screw 1 rotates in the cylinder 2 while receding linearly with respect to the cylinder 2 in the direction of the axis B, and the injection motor 15 rotates, causing the ball screw 12 to rotate and the screw drive shaft 10 to retreat. At this time, the retaining ring 4 follows the screw 1 linearly backwards, and the compression spring 5 provides back pressure compensation for the pre-plastic phase; the other back pressure is generated by the slip of the injection motor 13 and the pre-molding motor 6, preferably through a pressure sensor or the like. The device is used in conjunction with closed-loop control to adjust the back pressure.

The pre-molding phase is completed, the pre-molding motor 6 is locked, the injection motor 13 is powered, the ball screw 12 is driven to rotate by the first injection gear 14 and the second injection gear 15, and the ball nut and the ball of the shaft 10 are driven by the screw. When the screw 12 is engaged, the screw drive shaft 10 is driven to retreat linearly, and the screw 1 is retracted to complete the retraction of the screw 1.

2. Injection stage:

The pre-molding motor 6 is locked and does not rotate, and the injection motor 13 supplies power, and the ball screw 12 is driven to rotate by the first injection gear 14 and the second injection gear 15, and then the ball nut of the screw drive shaft 10 is engaged with the ball screw 12. The screw drive shaft 10 and the screw 1 are directly pushed forward along the axis B with respect to the barrel 2, and the injection action of the screw 1 is completed. During this process, the spring 5 is extended, and the released spring force provides partial pressure for the injection action.

Therefore, in the above process, only the screw 1, the retaining ring 4, the spring 5, and the screw drive shaft 10 are axially advanced or retracted, and linear movement is performed, and other power components and transmission components are not axially moved. The injection acceleration of the entire injection device is greatly improved, thereby improving the response acceleration and speed of the injection molding system, and ensuring The control precision of the injection action, while the back pressure compensation and injection pressure provided by the spring are also enhanced, the driving power of the injection system is reduced, the overall process of the injection molding system is improved, the efficiency is improved, and the cost is reduced.

The invention also provides an injection molding machine which adopts the above-mentioned injection molding device of the invention, has a small load during the injection molding process, and the acceleration is greatly improved, which helps to improve the process quality of the injection molded product.

In summary, the technical solutions of the injection molding system and the injection molding machine provided by the present invention have the following technical effects:

1. The screw drive shaft is integrated, and the double function of the ball spline and the ball nut is realized at the same time, which provides the guiding effect and greatly reduces the friction coefficient during the operation of the injection molding system and improves the injection acceleration.

2. When performing the injection action, there are few parts that need to be moved. Only the screw and screw drive shaft (and the selectively configured elastic energy storage device, including but not limited to springs, etc.) do axial forward and backward movement, while the motor, gear/belt The transmission part, the bearing set, the ball screw, the axial guiding mechanism and the injection slide seat are kept fixed, and do not move axially back and forth with the injection action. The moving part of the injection molding system is very light, and the injection pressure is constant. Under the hood, the total mass of the injection motion system is greatly reduced, the motion inertia is greatly reduced, and the acceleration obtained by the screw is greatly improved, so the effect speed and injection precision of the injection system are greatly improved.

3. The injection screw and the screw drive shaft are directly assembled, no additional installation process is required, so that the injection screw and the screw drive shaft can maintain synchronous movement, and the screw drive shaft is also designed for integral processing, and the stability of the injection molding system is greatly improved.

4. It is equipped with elastic energy storage device and is connected with the tail of the injection screw. It can compensate the back pressure during the pre-plasticization process, compress the energy storage, release the elastic energy storage device during the injection process, and directly and accurately push the thrust. The ground acts on the screw to effectively increase the injection pressure and speed; and the elastic energy storage mechanism and the screw drive shaft are coaxially arranged to improve the stability of the injection molding system.

5. The elastic energy storage device can perform back pressure compensation during the pre-plasticization process, and compresses the energy storage, effectively reducing the rated power of the injection drive motor and reducing the cost of the injection system.

Unless otherwise stated, the qualifiers similar to "first" and "second" appearing in this document do not refer to the limitation of chronological order, quantity, or importance, but merely to be a technique in the technical solution. Features are distinguished from another technical feature. Similarly, the qualifiers similar to "one" appearing herein are not intended to limit the quantity, but rather to describe the technical features that have not appeared in the foregoing. Similarly, modifiers similar to "about" and "approximately" appearing before a numeral in this document usually include the number and its specific The meaning should be understood in conjunction with the context. Similarly, unless a noun is modified by a particular quantity, it should be considered as including the singular and the plural. In the technical solution, the singular number of the technical features may be included, and the plural may also be included. Technical characteristics.

The description of the present invention is only a preferred embodiment of the present invention, and the above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit the present invention. Any technical solution that can be obtained by a person skilled in the art according to the concept of the present invention by logic analysis, reasoning or limited experimentation should be within the scope of the present invention.

Industrial applicability

In summary, the injection molding system and the injection molding machine provided by the present invention achieve the following technical effects and have industrial applicability:

1. The integrated design of the screw drive shaft realizes the dual function of the ball spline and the ball nut, which provides the guiding effect and greatly reduces the friction coefficient during the operation of the injection molding system and improves the injection acceleration.

Claims

An injection molding system for an injection molding machine, comprising:

a screw

a screw drive shaft, the screw drive shaft includes a ball spline and a ball nut, the screw is mounted on the screw drive shaft;

a ball screw, the ball screw being mounted in cooperation with the ball nut of the screw drive shaft, the ball screw moving the screw drive shaft and the screw back and forth in an axial direction; and

An axial guiding mechanism is mounted with the ball spline of the screw drive shaft.
The injection molding system according to claim 1, wherein in the injection molding system, the screw and the screw drive shaft are axially moved back and forth, and the ball screw and the axial guide mechanism are not used as an axis. Move back and forth.
The injection molding system of claim 1 wherein said screw drive shaft is integrally provided.
The injection molding system of claim 1 wherein said injection molding system further comprises an elastic energy storage device and a retaining ring, wherein said retaining ring is fitted to one end of said proximal screw drive shaft of said screw such that The movement state of the retaining ring is the same as that of the screw, and one end of the elastic energy storage device is mounted on the retaining ring, and the other end is fixed.
The injection molding system of claim 4 wherein said resilient energy storage mechanism and said screw drive shaft are coaxially disposed.
The injection molding system of claim 1 wherein the inner cavity of the axial guide mechanism and the ball spline of the screw drive shaft are mounted by ball fit such that the axial guide mechanism drives the screw The shaft is guided by the axial movement of the front and rear, and also provides the limit of the circumferential direction of the screw drive shaft.
An injection molding machine comprising the injection molding system and the mold clamping system according to any one of claims 1-6.