JP6300863B2 - Injection machine and injection mechanism - Google Patents

Description

  The present invention relates to the technical field of injection molding, and more particularly to an injection machine injection mechanism. The present invention further relates to an injection machine including the injection machine injection mechanism.

  The injection machine is known as an injection molding machine or a syringe. It is a main molding facility for producing thermoplastic or thermosetting plastic into plastic products of various shapes using a plastic molding die. In the plastic injection molding process, control of injection pressure is the key to improving product quality. For example, metered back pressure is one of the important parameters that actually control the material melt quality and product quality in the parameters of the injection molding process. The presence of the back pressure contributes to compactness of the raw material in the groove of the screw, elimination of gas in the raw material, and acceleration of heat transfer between the raw material particles.

  FIG. 1 shows a schematic diagram of the structure of an injection mechanism of a prior art injection machine. The injection mechanism of the injection machine includes a hopper 05, a feed cylinder 06, a screw 07 (screw) that adjusts the rotation of the injection base, an injection base 01, a ball screw 04, and a ball including a nut 03. Including a screw set. Further, the rotation of the ball screw 04 moves the nut 03 and moves forward to inject the molten material into the molding die.

  Conventionally, the injection pressure of the injection mechanism (-that is, the injection pressure and the metering back) is mainly obtained by using a disk-type pressure sensor 02 provided mainly between the screw 07 and the injection base or between the injection base and the ball screw. Pressure). When the disk-type pressure sensor 02 is provided between the injection base and the ball screw set, the injection base (specifically, the structure within the dotted frame in FIG. 1) is provided between the bearing 01 and the bearing 01. And a connecting body 08 provided at the end on the ball screw set side. The coupling body 08 is provided with a hollow sbase as a receiving space for receiving a part of the ball screw 04 after the screw 07 is retreated by injection so as to match the length of the injection stroke, thereby completing the entire injection process. Further, the bearing 01 and the coupling body 08 generally use an injection base cast directly in an integral molding or an injection base welded in an integral molding by welding.

  This increases the overall axial thickness of the injection base, increases the size and weight of the injection base, makes the overall injection machine heavier, less flexible, and increases the cost of the required space. Invite you.

  Further, when the disk-type pressure sensor 02 is provided between the screw 07 and the injection base, the temperature of the screw 07 is transmitted to the disk-type pressure sensor 02 in the injection process of the injection machine. As the temperature of 02 increases, the measurement error increases. In the measuring process, since the center screw 07 rotates, the housing of the disk-type pressure sensor 02 causes an error in the measured value due to the disturbance of the rotational torque and the thrust of the measured back pressure, and the pressure measurement accuracy and This will affect the control accuracy.

  Further, the cross-sectional area of the disk-type pressure sensor 02 is large, and similarly, the overall load of the injection machine is large and heavy, and the required space is increased.

  As described above, it is a problem to avoid a measurement error caused by a temperature rise due to the pressure-sensitive element, reduce the necessary space of the injector, and reduce the weight of the injector.

  In view of the above, an object of the present invention is to provide an injection mechanism of an injection machine capable of avoiding a measurement error in which a temperature rise due to a pressure-sensitive element has occurred, reducing a necessary space, and reducing weight. There is.

  Another object of the present invention is to provide an injection machine capable of avoiding a measurement error caused by a temperature rise due to a pressure-sensitive element, reducing a necessary space, and reducing a weight.

  To achieve the above object, the present invention includes an injection base, a ball screw set having a ball screw and a nut, and a through hole for rotating in accordance with the ball screw set. An injection mechanism for an injection machine comprising: a tubular pressure sensor having one end fixedly connected to the injection base and the other end fixedly connected to the nut.

  In the injection mechanism of the injection machine, the length of the tube of the tubular pressure sensor is preferably the same as the length of the injection stroke of the injection mechanism of the injection machine.

  In the injection mechanism of the injection machine, it is preferable that the injection base includes a bearing rotationally connected to a screw in the injection mechanism of the injection machine, and the tubular pressure sensor is fixedly connected to the bearing.

  In the injection mechanism of the injection machine, the tubular pressure sensor is fixedly connected to the injection base in accordance with a first bolt by a first flange, and is aligned with the second bolt by a second flange. It is preferable that the nut is fixedly connected to the nut.

  In the injection mechanism of the injection machine, the outer diameter of the first flange and the outer diameter of the second flange are preferably the same as the outer diameter of one end of the nut on the tubular pressure sensor side.

  In the injection mechanism of the injection machine, it is preferable that an annular thin tank is provided on the outer wall of the central portion of the tubular pressure sensor.

  In the injection mechanism of the injection machine, it is preferable that the tubular pressure sensor is a circular tube, and a tube length of the tubular pressure sensor is longer than an outer diameter of the tubular pressure sensor.

  According to the above technical features, the injection mechanism of the injection machine provided by the present invention includes an injection base, a ball screw set, and a tubular pressure sensor, and the through hole of the tubular pressure sensor is a ball of the ball screw set. As the screw rotates, one end of the tubular pressure sensor is fixedly connected to the injection base, and the other end is fixedly connected to the nut of the ball screw set.

In the present invention, the operation principle of measuring the injection pressure of the injection machine using a tubular pressure sensor is as follows.
That is, “When measuring the injection pressure in the injection process of the injection machine, the ball screw of the ball screw set is driven and rotated by an external force, and the nut of the ball screw set is fixed to one end of the tubular pressure sensor. By pushing forward the screw to be injected in the feed cylinder in the front, the molten plastic is injected through the nozzle toward the mold cavity, and the injection operation of injection molding is performed. The sensor measures the magnitude of the firing power and keeps the injection pressure constant by the closed loop control of the controller.After the injection is completed, it enters the metering step. It is driven and rotated by the external power of the electrical equipment of the The raw material in the cylinder is transported forward along the groove of the screw and compressed, the raw material is heated via external heat, and the double action of the shearing force of the screw causes the molten raw material to reach the screw head At the same time, the screw is retracted by the action of the pressure increase caused by the raw material that has been filled and melted in the space, and this retracting force is transmitted to the rotation transmission part, and this force is transmitted via the thrust bearing. Is transmitted to the tubular pressure sensor, which causes torsional deformation and further measures the backward force of the metering, and also controls the reverse force of the ball screw at a low speed by the controller. The operating principle is that the screw controls the stable back pressure when the nut is pulled back and further metered.

  The present invention realizes that the injection pressure of the injection machine and the pressure in the metering back pressure process are accurately measured and controlled by combining the tubular pressure sensor and the current pressure closed loop control. In addition, the present invention can guarantee not only a simple structure but also a dynamic response speed, thereby reducing system errors and having functions of immediate pressure control and precise pressure control, which greatly improves product quality. It is possible to improve.

  In addition, the present invention accepts the ball screw of the ball screw set by the through hole of the tubular pressure sensor, and the length of the ball screw protruding from the nut can be put into the through hole of the tubular pressure sensor, so that it needs to occupy extra space. And the injection base does not need to be increased in thickness due to the installation of a connecting body that provides a receiving space for the ball screw, so the overall axial thickness of the injection base is reduced. By reducing the size and weight, the required space of the injection machine can be reduced, the weight of the injection machine can be reduced, the flexibility can be further improved, and the cost can be reduced.

  Furthermore, the tubular pressure sensor is provided between the injection base and the ball screw set. On the other hand, the heat transfer of the temperature when the temperature of the screw and the feed cylinder becomes high is avoided, and the tubular pressure sensor is stabilized. The temperature is guaranteed, and on the other hand, the rotational torque when weighing is all in front of the injection base, so that obstruction of the rotational torque when weighing is removed, and all values measured by the tubular pressure sensor are This realizes a tubular pressure sensor with high accuracy, high stability, high overlap pressure measurement and control.

  The tubular pressure sensor has a small cross section and a small outer diameter, which can also reduce the overall load on the injection machine, reduce the weight, reduce the required space, and improve the space utilization rate. It is.

  The present invention further provides an injection machine including the injection mechanism of any of the above injection machines. In addition, since the injection mechanism of the injection machine has the above-described effect, the injection machine having the injection mechanism of the above-described injection machine also has the same effect, and thus the description thereof will not be repeated.

FIG. 1 is a schematic diagram of the structure of an injection mechanism of an injection machine in the prior art. FIG. 2 is a schematic diagram of the structure of the injection mechanism of the injection machine according to the embodiment of the present invention. FIG. 3 is an enlarged view of a partial structure of the injection mechanism of the injection machine according to the embodiment of the present invention. FIG. 4 is a front view of the tubular pressure sensor according to the embodiment of the present invention. FIG. 5 is a left side view of the tubular pressure sensor according to the embodiment of the present invention.

  Hereinafter, in order to more specifically describe the technical features of the embodiments of the present invention, drawings that must be used by the embodiments will be described. It is also apparent that the drawings disclose several embodiments of the invention. Further, those skilled in the art can understand the present invention based on these drawings only by their ordinary knowledge and routine experimentation.

  The embodiment of the present invention provides an injection mechanism of an injection machine that can avoid a measurement error caused by a temperature rise due to a pressure-sensitive element, reduce a required space, and reduce a weight.

  Hereinafter, in order to clarify the objects, technical features, and advantages of the embodiments of the present invention, the technical features of the embodiments of the present invention will be described clearly and sufficiently with reference to the drawings of the embodiments of the present invention. . It is also apparent that the examples describe some embodiments of the invention and not all examples. In addition, all other embodiments obtained by a person skilled in the art based on the embodiments of the present invention based only on the general knowledge and routine experimentation are within the scope of the present invention.

  2 to 5, the injection mechanism of the injection machine provided with the embodiment of the present invention includes a hopper 5, a feed cylinder 6, a screw 7, an injection base, a ball screw set, and a tubular pressure sensor 2. The hopper 5 provides raw material in the feed cylinder 6, the screw 7 is rotatably installed in the feed cylinder 6 and is rotatably connected to the injection base, and the ball screw set includes the ball screw 4 and the nut 3. The through hole of the tubular pressure sensor 2 is synchronized with the rotation of the ball screw 4 of the ball screw set, one end of the tubular pressure sensor 2 is fixedly connected to the injection base, and the other end is fixedly connected to the nut 3 of the ball screw set. ing.

The operating principle of the present invention for measuring the injection pressure of the injection machine using the tubular pressure sensor 2 is as follows.
That is, “when measuring the injection pressure in the injection process of the injection machine, the ball screw 4 of the ball screw set is driven and rotated by an external force, while the nut 3 of the ball screw set is fixed to one end of the tubular pressure sensor 2, By thrusting the screw 7 to be injected in the feed cylinder 6 with the ball screw set forward, the molten plastic is injected through the nozzle toward the mold cavity, and the injection operation of injection molding is performed. At this time, the magnitude of the radiant power is measured by the tubular pressure sensor 2, and the injection pressure is kept constant by the closed loop control of the controller. The screw 7 in the feed cylinder 6 is driven by the external power of other electrical equipment and rotated to With the action of -7, the raw material in the feed cylinder 6 is transported forward along the groove of the screw and compressed, the raw material is heated via external heat, and the double action of the shear force of the screw 7 The melted raw material is pressed down to the head portion of the screw 7, and at the same time, the screw 7 is moved back by the action of the pressure generated by the melted raw material filled in the space, and this retracting force is transmitted to the rotation transmission portion. And this force is transmitted to the tubular pressure sensor 2 through the thrust bearing, the tubular pressure sensor 2 generates a torsional deformation, and further, the measuring backward force is measured immediately. By controlling the reverse rotation of the screw 4 at low speed, the screw 7 controls the stable back pressure when the nut 3 is pulled back and further metered so that the retracting force decreases. Is a sense.

  In the present invention, the tubular pressure sensor 2 and the pressure closed loop control at the present stage are combined, so that the injection pressure of the injector and the pressure in the metering back pressure process can be accurately measured and controlled. In addition, the present invention can guarantee not only a simple structure but also a dynamic response speed, thereby reducing system errors, having functions of immediate pressure control and precise pressure control, and greatly improving product quality. To improve.

  Further, according to the present invention, the ball screw 4 of the ball screw set can be received by the through hole of the tubular pressure sensor 2, and the length that the ball screw 4 protrudes from the nut 3 can be put in the through hole of the tubular pressure sensor 2. Since the injection base does not need to occupy a large space and there is no need to increase the thickness due to the installation of the coupling body that provides the receiving space for the ball screw 4, the overall axial thickness of the injection base By reducing the size and weight of the injection base, the required space of the injection machine can be reduced, the weight of the injection machine can be reduced, the flexibility can be further improved, and the cost can be reduced.

  Furthermore, since the tubular pressure sensor 2 is provided between the injection base and the ball screw set, on the other hand, heat transfer at a temperature when the temperature of the screw 7 and the feed cylinder 6 becomes high is avoided, and the tubular pressure sensor 2 that guarantees a stable temperature of 2, and on the other hand, the rotational torque at the time of metering is all in front of the injection base, so that obstruction of the rotational torque at the time of metering is eliminated, and the value measured from the tubular pressure sensor 2 Are the pressures of the metering back pressure, thereby realizing the tubular pressure sensor 2 having high accuracy, high stability, high overlap pressure measurement and control.

  The tubular pressure sensor 2 has a small cross section and a small outer diameter, which can similarly reduce the overall load on the injection machine, reduce the weight, reduce the required space, and improve the space utilization rate. Is possible.

  The length of the tube of the tubular pressure sensor 2 is preferably equal to the length of the injection stroke of the injection mechanism of the injection machine. In the present invention, the length of the tube of the tubular pressure sensor 2 is the same as the length of the injection stroke of the injection mechanism of the injection machine. In this way, when the injection base is retreated, the nut 3 causes the injection base to back in accordance with the rotational movement of the ball screw 4 in one direction. At this time, the ball protruding from the nut 3 A part of the screw 4 is in the through hole of the tubular pressure sensor 2. In addition, when the injection base is moved forward by the injection operation, the nut 3 moves the injection base forward according to the rotational movement of the ball screw 4 in the other direction. At this time, the ball screw 4 is as if it is tubular. The fact that the pressure sensor 2 is flush with the end of the nut 3 that is in close proximity reduces the length of the tube of the tubular pressure sensor 2 to the maximum on the premise of satisfying the movement of the ball screw set. And further reduce the overall load and weight of the injector. Further, it can be understood that the length of the tube of the tubular pressure sensor 2 may be shorter or longer than the length of the injection stroke of the injection mechanism of the injection machine. In this regard, the present invention is not specifically limited. Further, as shown in FIGS. 4 and 5, the tubular pressure sensor 2 is fixedly connected to the injection base so as to be aligned with the first bolt by the first flange 21 so that the tubular pressure sensor 2 can be installed. At the same time, the second flange 22 is fixedly connected to the nut 3 in alignment with the second bolt. In the present invention, since both ends of the tubular pressure sensor 2 are fixed by the flange, the fixing strength is good and the attachment is detachable. Even if the outer diameter of the tubular pressure sensor 2 is small, the tubular pressure sensor 2 can be effectively fixed. The tubular pressure sensor 2 can be fixed by welding or other fixing methods.

  In a preferred embodiment of the present invention, the injection base includes a bearing 1 that is rotationally connected to a screw 7 in an injection mechanism of the injection machine, and the tubular pressure sensor 2 is fixedly connected to the bearing 1. The comparison between the dotted line frame in FIG. 1 and the inside of the dotted line frame in FIG. 2 is a structural comparison between the injection base of the prior art and the injection base of the present invention. The injection base of the present invention includes a bearing 1 and uses a tubular pressure sensor 2 instead of the connecting body 08 in the injection base which is a conventional technique. Further, since the hollow portion and the entire length of the tubular pressure sensor 2 are matched to the length of the injection stroke, the overall load and weight of the apparatus can be reduced.

  Furthermore, the outer diameter of the first flange 21 and the outer diameter of the second flange 22 are the same as the outer diameter of the end of the nut 3 on the tubular pressure sensor 2 side. Moreover, the said 1st flange 21 and the 2nd flange 22 do not occupy the extra outer diameter which protruded from the nut 3, and reduce a required space. It can be understood that the first flange 21 and the second flange 22 may protrude from the end of the nut 3 on the tubular pressure sensor 2 side.

  Further, in order to further reduce the weight of the injection machine, the injection mechanism of the injection machine according to the above embodiment is provided with the annular thin tank 23 on the outer wall of the central portion of the tubular pressure sensor 2, so that the tubular pressure sensor 2 Reduced the weight. Moreover, said annular thin tank 23 is easy to process. It goes without saying that weight reduction can be realized in the same manner by adopting a plurality of circular thin tanks or other thin tanks.

In a specific embodiment, the tubular pressure sensor 2 is a circular tube. In this embodiment, the tubular pressure sensor 2 has an annular shape in cross section, its inner hole is a circular hole in accordance with the rotation of the ball screw 4, and its outer wall is circular. Further, from the viewpoint of easy manufacture, the shape of the inner wall of the tubular pressure sensor 2 having the above shape is the same as the shape of the outer wall. At the same time, since the length of the tube of the tubular pressure sensor 2 is longer than the outer diameter of the tubular pressure sensor 2, it can be ensured that the tubular pressure sensor 2 exhibits an elongated type, and the required space is reduced. , Reduce weight. Moreover, the cross-sectional shape of the tubular pressure sensor 2 may be rectangular. In this case, the outer wall is also rectangular, and the length of the tube of the tubular pressure sensor 2 is the cross-sectional shape of the tubular pressure sensor 2. It can be understood that it is longer than the long side (which may be the short side). Further, the cross-sectional shape of the tubular pressure sensor 2 may be a square shape, an oval shape, or another irregular shape. Further, the length of the tube of the tubular pressure sensor 2 may be shorter than or equal to the outer diameter of the tubular pressure sensor 2. In this regard, the present invention is not specifically limited.

  The present invention is an injection machine including an injection mechanism, and has the advantages that a measurement error caused by a temperature rise due to a pressure-sensitive element can be avoided, a necessary space can be reduced, and a weight can be reduced. An injection mechanism of an injection machine according to any one embodiment is provided. Further, the above-mentioned advantages are brought about by the injection mechanism of the injection machine, and specifically, refer to related portions in the above-described embodiments.

  Each example in this specification has been described step by step. Each embodiment has been described as being different from the other embodiments. In each embodiment, the same or similar parts should be referred to each other.

  The description of the above disclosed embodiments will enable those skilled in the art to implement or use the present invention. It will be apparent to those skilled in the art that various changes and modifications may be made to these embodiments, and they may be applied to other embodiments without departing from the scope or spirit of the invention. Accordingly, the invention is not to be limited by these examples shown herein, but is to be embraced by the broadest claims consistent with the principles and novel features disclosed herein.

01, 1 bearing 02 disc type pressure sensor 03, 3 nut 04, 4 ball screw 05, 5 hopper 06, 6 feed cylinder 07, 7 screw 08 connection body 2 tubular pressure sensor 21 first flange 22 second flange 23 Annular thin tank

Claims (7)

An injection base;
A ball screw set having a ball screw and a nut; and
A tubular pressure sensor having a through hole for rotating in accordance with the ball screw set, one end fixedly connected to the injection base and the other end fixedly connected to the nut; An injection mechanism of an injection machine including
The tubular pressure sensor receives the ball screw in the through hole;
The injection base includes a bearing that is rotationally connected to a screw in an injection mechanism of the injection machine,
The tubular pressure sensor is an injection mechanism of an injection machine fixedly connected to the bearing.   The injection mechanism of the injection machine according to claim 1, wherein the length of the tube of the tubular pressure sensor is the same as the length of the injection stroke of the injection mechanism of the injection machine. The pipe-like pressure sensor, the first flange being fixed connected to the injection base in accordance with the first bolt is fixed connected to the nut in accordance with the second bolt by a second flange, The injection mechanism of the injection machine according to claim 1.   The injection mechanism of the injection machine according to claim 3, wherein an outer diameter of the first flange and an outer diameter of the second flange are the same as an outer diameter of an end of the nut on the tubular pressure sensor side.   The injection mechanism of the injection machine according to any one of claims 1 to 4, wherein an annular thin tank is provided on an outer wall of a central portion of the tubular pressure sensor. The tubular pressure sensor is a circular tube,
The injection mechanism of the injection machine according to claim 5, wherein a length of the tube of the tubular pressure sensor is longer than an outer diameter of the tubular pressure sensor. The injection machine containing the injection mechanism of the injection machine as described in any one of Claims 1 thru | or 6.