WO2018218767A1

WO2018218767A1 - High performance electric injection device

Info

Publication number: WO2018218767A1
Application number: PCT/CN2017/094479
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: 2017-07-26
Publication date: 2018-12-06
Also published as: CN108943625B; CN108943625A; WO2018218431A1

Abstract

An injection system of an injection molding machine and an injection molding machine. The injection system of an injection molding machine comprises a screw (1); a transmission shaft (10), the transmission shaft (10) comprising a ball spline section and a ball screw section, or the transmission shaft (10) comprising a ball spline section and a planetary roller screw section; and a nut mechanism and an axial guide mechanism (11). The injection molding machine comprises the injection system and a mold closing system. When the injection system and the injection molding machine perform an injection action, except the screw (1) and the transmission shaft (10), there are few components required to move, i.e., other driving and transmission components do not make axial motion along the injection action. During an injection action, the system has a light mass and the motion inertia is decreased, such that the response speed and precision of the injection action is improved, and the driving efficiency is reduced.

Description

High performance electric injection unit

Technical field

The present invention belongs to the field of plastics and relates to an electric injection molding apparatus 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 drive shaft, the drive shaft includes a ball spline segment and a ball screw segment, or the drive shaft includes a ball spline a segment and a planetary roller screw segment, the screw being mounted on the drive shaft;

a nut mechanism, the nut mechanism being mounted in cooperation with the ball screw segment or the planetary roller screw segment, the nut mechanism moving the drive shaft and the screw forward and backward in an axial direction; and

An axial guiding mechanism is mounted in cooperation with a ball spline segment of the drive shaft, the axial guiding mechanism rotating the drive shaft and the screw about an axis of the drive shaft.

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

Preferably, the 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 proximal drive shaft of the screw such that the movement state of the retaining ring is the same as the screw 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 device and the transmission shaft are coaxially disposed.

Preferably, the nut mechanism is a ball nut.

Preferably, the inner cavity of the axial guiding mechanism and the ball spline segment are mounted by ball cooperation, so that the axial guiding mechanism guides the transmission shaft to move axially forward and backward, and also provides the transmission Limit of the circumference of the shaft.

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 solutions of the injection molding system and the injection molding machine provided by the invention have the following advantages:

1. In the injection molding system and the injection molding machine provided by the present invention, the transmission shaft includes a ball spline segment and a ball screw segment, or the transmission shaft includes a ball spline segment and a planetary roller screw segment, and the transmission shaft is integrally provided. The dual functions of ball spline and ball screw, or ball spline and planetary roller screw are realized on the same drive shaft, which provides guiding effect and greatly reduces the friction coefficient during the operation of the injection molding system. Shoot the acceleration.

2. In the injection molding system and the injection molding machine provided by the present invention, when the injection operation is performed, few parts need to be moved, and only the screw and the transmission shaft (and the selectively arranged elastic energy storage device, including but not limited to a spring, etc.) are used as the shaft. Moving forward and backward, and the motor, gear/belt drive, bearing set, nut mechanism, 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 mass is very light. When the injection pressure is constant, 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 of the injection molding system of the invention is directly assembled with the drive shaft, and no additional installation process is required, so that the injection screw and the drive shaft can maintain synchronous movement, and the drive shaft is also designed for integral processing, and the stability of the injection molding system. Greatly improve.

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 on the screw to effectively increase the injection pressure and speed; and the elastic energy storage device and the transmission 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. Transmission shaft: The transmission shaft of the invention is an integral arrangement, which refers to processing one section of the same shaft into a ball spline, and the other section into a ball screw or a planetary roller screw, a ball screw/plane rolling The column screw and the ball spline are integrated, that is, they have the characteristics and functions of the screw and the spline on the same shaft.

2. Axial guiding mechanism: It is matched with the spline shaft part of the transmission shaft to guide the axial movement and provide the limit in the circumferential direction.

3. Nut mechanism: It is installed with the ball screw segment of the drive shaft or the planetary roller screw segment. Through the rotation of the nut, the drive shaft can be driven to move linearly, and the drive shaft can also provide partial axial 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 during the operation of the injection molding system, improve the response speed and accuracy of the injection molding system, and reduce the driving power of the injection molding system and improve the driving power of the injection molding system. Performance reduces 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, drive shaft 10, axial The guide mechanism 11, the nut 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, the use of hollow shaft motor direct drives, and the like, which are 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 of completing the function of the injection drive mechanism, including but not limited to the use of a hollow shaft motor direct drive, etc., is well known to those skilled in the art, for example, by directly attaching the hollow shaft motor to the nut at the end; or The injection motor is fixed to the end of the nut 12, the first injection gear 14 and the second injection gear 15 are omitted, and the nut 12 is driven to rotate in a direct drive manner.

In an embodiment of the invention, preferably, the injection molding system includes a cooperating drive shaft and an axial guiding mechanism, the axial guiding mechanism provides axial guidance of the transmission shaft, and simultaneously rotates the transmission shaft and the screw about the axis of the transmission shaft, Those skilled in the art can employ other alternative configurations to achieve the function of transmitting the rotation of the drive mechanism to the screw and axially moving the screw.

In the embodiment of the present invention, the position at which the force transmitting portion functions is not limited to the embodiment of the present invention. For example, depending on the driving method, the nut can be rotated by a drive motor or the like, and the relative rotation of the nut causes the drive shaft to advance and retreat in the axial direction, and the position at which the thrust generated by the relative rotation of the nut is transmitted is used as the force. Delivery department. In short, the position at which the thrust generated by the relative rotation between the drive shaft and the nut is transmitted can be used as the force transmitting portion.

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

The transmission shaft 10 is integrally provided, that is, the transmission shaft 10 is a single shaft integrally processed, the transmission shaft 10 includes a ball spline segment and a ball screw segment, or the transmission shaft 10 includes a ball spline segment and a planetary roller screw segment. Wherein, the ball spline segment uses the ball spline pair to drive the pre-plasticizing action, and provides guidance for the screw 1, and the ball screw segment or the planetary roller screw segment drives the injection action while assisting the screw guiding.

The tail end of the screw 1 is fixedly coupled to the front end of the transmission shaft 10 to ensure that the movement state of the screw 1 is the same as that of the transmission shaft 10.

The inner cavity of the axial guiding mechanism 11 and the ball spline section of the transmission shaft 10 are mounted by ball cooperation, so that the axial guiding mechanism 11 provides the guiding of the driving shaft 10 for axial movement before and after, and also performs the circumferential limit. .

Preferably, the length of the ball spline section of the transmission shaft 10 in the direction of the central axis of the screw 1 is greater than the length of the axial guiding mechanism 11 in the direction of the central axis of the screw 1, so that the transmission shaft 10 and the screw 1 are in the axial direction. In the linear motion, the axial guiding mechanism 11 and the ball spline segment of the transmission shaft 10 are always fitted.

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 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 inner cavity of the nut 12 is fitted with the ball screw segment of the transmission shaft 10 or the planetary roller screw segment, and the outer ring of the nut 12 is mounted to the rear end of the fixed frame 3 through the second bearing set 16, thereby performing the nut 12 The axial limit is fixed, but the nut 12 is rotatable along the axis. Preferably, the nut 12 is a ball nut.

The second injection gear 15 is fixedly coupled to the end surface of the nut 12. The rotation of the second injection gear 15 can drive the nut 12 to rotate, thereby driving the ball screw segment of the transmission shaft 10 or the planetary roller screw segment to perform axial movement.

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, the operation of the injection molding system 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 to be 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 passing the balls of the axial guiding mechanism 11 and the transmission shaft 10. The spline segment cooperates to drive the transmission shaft 10 to rotate about the axis, and the driving screw 1 rotates to perform a pre-plasticizing 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 A, and the injection motor 13 rotates, so that the nut 12 rotates and the transmission shaft 10 retreats. 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 stage is completed, the pre-molding motor 6 is locked, the injection motor 13 is powered, the nut 12 is driven to rotate by the first injection gear 14 and the second injection gear 15, and the transmission is driven by the cooperation of the nut 12 and the transmission shaft 10. The shaft 10 is retracted 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, the injection motor 13 provides power, the nut 12 is driven to rotate by the first injection gear 14 and the second injection gear 15, and the nut 12 and the transmission shaft 10 are engaged to drive the ball screw of the transmission shaft 10. The segment or planetary roller screw segment advances linearly, thereby directly pushing the drive shaft 10 and the screw 1 linearly along the axis A with respect to the barrel 2, completing the injection action of the screw 1, during which the spring 5 is extended and the spring force is released. Provide partial pressure for the injection action.

Therefore, during the operation of the above injection molding system, only the screw 1, the retaining ring 4, the spring 5, and the transmission shaft 10 are linearly moved forward or backward, and other power components and transmission components are not axially moved. The injection acceleration of the whole injection device is greatly improved, thereby improving the response acceleration and speed of the injection molding system, ensuring the control precision of the injection action, and the back pressure compensation and injection pressure provided by the spring are also enhanced, thereby reducing the driving power of the injection system. Improve the overall process of the injection molding system, improve efficiency and reduce costs.

The invention also provides an injection molding machine which adopts the above-mentioned injection molding system 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 injection molding system and the injection molding machine provided by the present invention achieve the following technical effects:

1. The integrated design of the transmission shaft realizes the dual functions of the ball spline and the ball screw/planetary roller screw, which provides 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 the drive shaft move axially back and forth, and the motor, gear/belt transmission part, bearing set, nut mechanism, axial guiding mechanism, and injection slide seat, etc. The other components are kept fixed and do not move axially back and forth with the injection action. The moving part of the injection molding system is light in weight, and when the injection pressure is constant, 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 drive shaft are directly assembled, no additional installation process is required, so that the injection screw and the drive shaft can maintain synchronous movement, and the drive shaft is also designed for integral processing, and the stability of the injection molding system is greatly improved.

4. The elastic energy storage device is connected with the tail of the injection screw. During the pre-plasticization process, the back pressure compensation can be performed, and the energy storage is compressed, and the elastic energy storage device is released during the injection process, and the thrust can be directly applied to the screw, effectively The injection pressure and speed are increased; and the elastic energy storage device and the 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 such as "about" and "approximately" which are used in the context of the word "a" or "an" 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:

2. When performing the injection action, there are few parts that need to be moved. Only the screw and the drive shaft move axially back and forth, and the motor, gear/belt drive part, bearing set, ball nut mechanism, axial guide mechanism, and injection slide base When other components are kept fixed, do not move axially back and forth with the injection action, the moving part of the injection molding system is light in weight, and the total mass of the injection movement system is greatly reduced and the motion inertia is greatly reduced when the injection pressure is constant. The acceleration obtained is greatly increased, so the effect speed and injection accuracy of the injection system are greatly improved.

4. The elastic energy storage device is connected with the tail of the injection screw, and the back pressure can be compensated during the pre-plasticizing process, and the pressure is applied. The energy storage device can release the elastic energy storage device during the injection process, and the thrust can be directly applied to the screw to effectively increase the injection pressure and speed; and the elastic energy storage mechanism and the transmission shaft are coaxially arranged to improve the stability of the injection molding system. Sex.

Claims

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

a screw

a drive shaft, the drive shaft includes a ball spline segment and a ball screw segment, or the drive shaft includes a ball spline segment and a planetary roller screw segment, the screw is mounted on the drive shaft;

a nut mechanism that is mounted in cooperation with the ball screw segment of the transmission shaft or the planetary roller screw segment, the nut mechanism moving the transmission shaft and the screw back and forth in the axial direction ;with

An axial guiding mechanism is mounted in cooperation with a ball spline segment of the drive shaft, the axial guiding mechanism rotating the drive shaft and the screw about an axis of the drive shaft.
The injection molding system according to claim 1, wherein in the injection molding system, the screw and the transmission shaft are axially moved back and forth, and the nut mechanism and the axial guiding mechanism are not axially front and rear. mobile.
The injection molding system of claim 1 wherein said 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 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 kept fixed.
The injection molding system of claim 4 wherein said resilient energy storage device and said drive shaft are coaxially disposed.
The injection molding system according to claim 1, wherein the inner cavity of the axial guiding mechanism and the ball spline segment are mounted by ball cooperation such that the axial guiding mechanism makes a front and rear axle to the transmission shaft The guiding to the movement also provides a limit in the circumferential direction of the drive shaft.
The injection molding system of claim 1 wherein said nut mechanism is a ball nut.
An injection molding machine comprising the injection molding system and the mold clamping system according to any one of claims 1-6.