JP6494945B2 - Injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine that injects a thermoplastic resin melted by a heating cylinder into a mold cavity, and in particular, after kneading the thermoplastic resin in the heating cylinder, the kneaded thermoplastic resin The present invention relates to an injection molding machine in which the mixture is further kneaded in an injection nozzle and then injected into a mold cavity.

  In a general injection molding machine that has been used in the past, a granular thermoplastic resin as a raw material is fed into a heating cylinder, and the nozzle at the tip of the screw is melted by the rotation of a screw provided in the heating cylinder. The molten resin is injected into the mold cavity closed from the injection nozzle provided on the tip side of the screw by feeding out to the side and the mold is cooled and solidified by cooling the molten resin in the cavity. The molded product is manufactured by opening the plate and taking out the molded product stuck to the inner surface of the mold with a protruding pin or the like.

  The resin injected into the mold cavity must be thoroughly kneaded before being injected into the mold cavity. If the resin is not sufficiently kneaded, a good-quality molded product cannot be obtained. In Patent Document 1, in order to promote resin kneading, a torpedo having a plurality of resin passages arranged in a ring at a predetermined pitch is accommodated in a heating cylinder, and the resin is effectively kneaded by the torpedo. Is disclosed. Further, Patent Document 2 filed by the applicant of the present application discloses that a rectifying chip for kneading molten resin is provided in a connecting portion that connects an injection portion and a heating cylinder.

JP 2006-297670 A JP 2013-237227 A

  In Patent Document 1, in order to improve the kneadability of the resin, the torpedo is accommodated in the heating cylinder through which the resin passes. However, when taking out the torpedo from the heating cylinder for maintenance or the like, it is injected from the heating cylinder. After removing the nozzle, the torpedo must be taken out from the inside of the heating cylinder that is fixed to the frame or the like. For example, if residual resin adheres to the surface of the torpedo or the heating cylinder, the torpedo is taken out. It will be difficult to work.

  Moreover, in patent document 2, the rectification | straightening chip which knead | mixes molten resin is provided in the connection part which connects an injection | pouring part and a heating cylinder, and when taking out a rectification | straightening chip from the inside of a connection part, it injects from a connection part. The rectification chip is taken out from the inside of the heating cylinder that is fixed to the frame or the like only by removing the portion, which makes it difficult to take out the rectification chip. Therefore, in order to eliminate such problems, it is possible to improve the workability of taking out the rectifying chip from the connecting portion by further removing the connecting portion from the heating cylinder after removing the injection portion from the connecting portion. However, in such a case, it takes time and effort to take out the rectifying chip.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an injection molding machine capable of easily attaching and detaching a mixing element for kneading a thermoplastic resin by turbulent flow in a short time. .

The invention of this injection molding machine
A heating cylinder to which a thermoplastic resin is supplied; a screw rotatably provided in the heating cylinder; and an injection nozzle attached to a tip of the heating cylinder. The rotation of the screw causes the heating cylinder to enter the heating cylinder. An injection molding machine in which, after the supplied thermoplastic resin is kneaded, the kneaded thermoplastic resin is injected into a mold cavity closed through a resin path formed in the injection nozzle,
The injection nozzle, an injection unit for injecting the thermoplastic resin into the mold closed the mold cavity, is composed of a connecting portion for detachably connecting the injection-section to said heating cylinder,
In the inside of the injection part, a removable mixing element that is held so as not to move in the front-rear direction by being sandwiched between the injection part and the connecting part is provided,
The mixing element has a cylindrical cylindrical portion having a resin path formed therein, and the thermoplastic resin supplied to the injection portion is distributed into the cylindrical portion by a disturbance. With a turbulent flow plate
A plurality of the turbulent flow plates are provided in the direction in which the thermoplastic resin flows. The turbulent plates are formed so as to extend from the inner wall surface of the cylindrical portion, and span the inner wall surface of the cylindrical portion. It is formed integrally with the cylindrical portion, and is characterized in that it is formed in a cross shape that partitions the resin path into a plurality of parts .

The invention of this injection molding machine
A plurality of the turbulent flow plates provided in the direction in which the thermoplastic resin flows are arranged from the upstream side to the downstream side in the direction in which the thermoplastic resin flows with respect to the plurality of turbulent plates arranged in the direction in which the thermoplastic resin flows. When numbers are assigned in order of integer numbers 1, 2, 3,..., Odd-numbered turbulent plates are arranged so as to face each other, while even-numbered turbulent plates are also opposed to each other. Further, the odd-numbered turbulent flow plate and the even-numbered turbulent flow plate are arranged so as not to face each other, and the odd-numbered turbulent flow plate and the even-numbered turbulent flow plate are arranged. The position shift angle with is 45 degrees,
When provided with the mixing element inside the injection unit, and wherein the Rukoto comprising a rotation restricting means for preventing rotation of said mixing element.

  According to the present invention, the mixing element provided inside the injection unit is provided with the turbulent flow plate that generates turbulent flow by diverting the thermoplastic resin supplied to the injection unit of the injection nozzle. In addition to kneading the thermoplastic resin accompanying the rotation of the screw, the thermoplastic resin can be kneaded by the turbulent flow plate even in the injection nozzle, so that the thermoplastic resin can be sufficiently kneaded. As a result, a high-quality molded product can be obtained.

  Furthermore, according to the present invention, when taking out the mixing element provided with the turbulent flow plate to the outside of the injection molding machine for maintenance or the like, just remove the injection part from the connecting part that connects the injection part and the heating cylinder, It becomes possible to take out the mixing element to the outside of the injection molding machine. Therefore, the mixing element can be easily attached and detached in a short time.

  Furthermore, since the plurality of turbulent plates arranged in the direction in which the thermoplastic resin flows are arranged so as not to face each other in the adjacent relationship, between the turbulent plates displaced from each other, etc. A turbulent flow can be effectively generated with respect to the passing thermoplastic resin. Therefore, kneading of the thermoplastic resin can be effectively performed.

  Furthermore, the turbulent flow plate formed in the mixing element has a complicated structure because the odd-numbered turbulent flow plate and the even-numbered turbulent flow plate are arranged so as not to face each other. ing. Therefore, it is difficult to form a mixing element having a complicated internal structure by a general cutting process, but the mixing element of the present invention having a complicated internal structure can be obtained by applying a 3D printer capable of laminating. Even it can be molded.

  Furthermore, since the rotation restricting means for preventing the rotation of the mixing element is provided, the mixing element can be prevented from rotating when the thermoplastic resin is kneaded while passing through the injection nozzle.

1 is a schematic configuration diagram illustrating an injection molding machine according to Embodiment 1. FIG. It is sectional drawing which shows the principal part of the injection molding machine of Example 1. It is a disassembled perspective view which shows the injection part of the injection nozzle in the injection molding machine of Example 1, and the mixing element which can be inserted or removed to this injection part. It is a perspective view which shows the mixing element comprised by the injection nozzle in the injection molding machine of Example 1. FIG. It is a perspective view which shows the cross section of the mixing element comprised by the injection nozzle in the injection molding machine of Example 1. FIG. It is a perspective view which shows the mixing element comprised by the injection nozzle in the injection molding machine of Example 1. FIG. It is a perspective view which shows the mixing element comprised by the injection nozzle in the injection molding machine of Example 2. FIG. It is a perspective view which shows the cross section of the mixing element comprised by the injection nozzle in the injection molding machine of Example 2. FIG. It is a perspective view which shows the mixing element comprised by the injection nozzle in the injection molding machine of Example 3. FIG. It is sectional drawing which shows the mixing element comprised by the injection nozzle in the injection molding machine of Example 3. FIG. It is a perspective view which shows the mixing element comprised by the injection nozzle in the injection molding machine of Example 4. FIG. It is a perspective view which shows the cross section of the mixing element comprised by the injection nozzle in the injection molding machine of Example 4. FIG.

  Embodiments of the present invention will be described below with reference to FIGS. Needless to say, the present invention can be easily applied to configurations other than those described in the embodiments without departing from the spirit of the invention.

  An injection molding machine 1 according to an example of the present invention shown in FIG. 1 manufactures a molded body using pellets as a granular thermoplastic resin as a raw material. The injection molding machine 1 includes a machine base 2 and a machine base 2. An injection unit 3 and a mold clamping unit 4 are disposed on the top.

  The mold clamping unit 4 is provided with a mold opening / closing mechanism for moving the movable mold 6 forward and backward with respect to the fixed mold 5 to perform mold clamping (mold closing) and mold opening. The movable die plate 9 is advanced and retracted by bending the toggle link mechanism 7 using the driving force of the motor as a drive source, and the movable die plate 9 fixed to the fixed die plate 8 is fixed to the movable die plate 9. The mold 6 is opened and closed repeatedly.

  The injection unit 3 includes a cylindrical heating cylinder 10, an injection nozzle 11 provided at the tip of the heating cylinder 10, and a screw 12 provided in the heating cylinder 10 for kneading a thermoplastic resin supplied into the heating cylinder. A support member 13 that rotatably supports the screw 12, a hopper 14 into which pellets made of thermoplastic resin are charged, a hopper block 15 provided with the hopper 14, and the like are configured.

  When the screw 12 provided in the heating cylinder 10 is rotated, the thermoplastic resin supplied from the supply port 16 to the rear side of the heating cylinder 10 is kneaded to the tip side of the heating cylinder 10 provided with the injection nozzle 11. The thermoplastic resin supplied into the heating cylinder 10 and heated and melted in the heating cylinder 10 is supplied to the screw 12 by a rotational driving means (not shown) composed of a metering motor or the like. After being measured by the measuring unit by being rotated, the screw 12 is advanced by an advancing / retreating drive means including an injection motor, a ball screw mechanism, etc., so that a predetermined amount is melted into the mold-closed cavity. The thermoplastic resin thus injected is injected through the injection nozzle 11. As shown in FIG. 1, a heater 17 is provided outside the heating cylinder 10, and the heater 17 is heated to a high temperature so that the thermoplastic resin supplied to the inside of the heating cylinder 10 is used. Some pellets are melted.

  Here, the injection nozzle 11 attached to the tip of the heating cylinder 10 will be described below with reference to FIGS.

  As shown in FIG. 2, the injection nozzle 11 has an injection part 20 for injecting thermoplastic resin from the tip into the mold cavity, and the injection part 20 is detachably attached to the tip of the heating cylinder 10. A connecting portion 21 to be connected is configured.

  As shown in FIGS. 3 to 6, a mixing element 23 including a plurality of turbulent plates 22 can be inserted into and removed from the inside of the injection unit 20. As shown in FIG. 2, the mixing element 23 inserted into the injection unit 20 is mounted with the injection nozzle 11 at the tip of the heating cylinder 10, so that when the injection unit 20 is screwed to the connecting unit 21. The front and rear of the mixing element 23 are held between the injection part 20 and the connecting part 21 so as not to move back and forth. In this state, the rotation restriction provided at the rear part of the mixing element 23 By means 24, the mixing element 23 is prevented from rotating inside the injection part 20.

  As shown in FIGS. 4 to 6, the mixing element 23 includes a cylindrical cylindrical portion having a resin path 25 formed therein, and the turbulent flow plate 22 included in the cylindrical portion is an inner wall surface of the cylindrical portion. Are formed in a cross shape extending in the radial direction from the four locations and intersecting at the center. In other words, the turbulent flow plate 22 is formed in a cross shape so as to span the inner wall surface of the cylindrical portion. A plurality of turbulent flow plates 22 are arranged in the direction in which the thermoplastic resin flows. Specifically, as shown in FIG. 6, six turbulent flow plates 22 are intermittently arranged in the direction in which the thermoplastic resin flows. Has been.

  The plurality of turbulent flow plates 22 formed in a cross shape when viewed from the resin flow direction are numbered in the order of integers 1, 2, 3,... In the order from the upstream side to the downstream side in the flow direction of the thermoplastic resin. Then, the odd-numbered turbulent plates 22 of Nos. 1, 3, and 5 are arranged so as to face each other, and the even-numbered turbulent plates 22 of Nos. 2, 4, and 6 are also mutually connected. It arrange | positions so that it may oppose. The odd numbered turbulent flow plate 22 and the even numbered turbulent flow plate 22 are set to be 45 degrees so that the odd numbered turbulent flow plate 22 and the even numbered turbulent flow plate 22 do not face each other. When the thermoplastic resin passes through the resin path 25 in the cylindrical portion of the mixing element 23, the turbulent flow is caused by the turbulent flow plates 22 to be divided into the turbulent flow. The kneading of the plastic resin is sufficiently performed before being injected into the mold cavity. In addition, a plurality of cross-shaped turbulent flow plates 22 are provided, and the plurality of turbulent flow plates 22 have a complicated shape arranged so as to be alternately displaced at an angle of 45 degrees in the direction in which the thermoplastic resin flows. The mixing element 23 according to the present embodiment is difficult to be formed only by a generally known cutting process, and is therefore integrally formed using a 3D printer capable of laminating.

  According to the injection molding machine 1 of Example 1 as described above, the turbulent flow plate 22 that causes turbulent flow by diverting the thermoplastic resin supplied into the cylindrical portion of the injection portion 20 of the injection nozzle 11 is provided. Since the mixing element 23 provided in the injection portion is provided, the thermoplastic resin is kneaded by the turbulent flow plate 22 in the injection nozzle 11 in addition to the kneading of the thermoplastic resin accompanying the rotation of the screw 12 in the heating cylinder 10. Therefore, it is possible to sufficiently knead the thermoplastic resin. As a result, a high-quality molded product can be obtained.

  Further, when the mixing element 23 is taken out of the injection molding machine 1 for maintenance or the like, the injection part 20 is simply removed from the connecting part 21 that connects the injection part 20 and the heating cylinder 10 to the outside of the injection molding machine 1. The mixing element 23 can be taken out. Therefore, in addition to the work of taking out the mixing element 23, the work of attaching the mixing element 23 can be easily performed in a short time.

  Furthermore, since the plurality of turbulent flow plates 22 arranged in the direction in which the thermoplastic resin flows are arranged so as not to face each other in the adjacent relationship, the turbulent flow plates 22 shifted in position are arranged. A turbulent flow can be effectively generated with respect to the thermoplastic resin passing between the two. Therefore, kneading of the thermoplastic resin can be effectively performed.

  Furthermore, since the turbulent flow plate 22 formed in the mixing element 23 is arranged so that the odd-numbered turbulent flow plate 22 and the even-numbered turbulent flow plate 22 do not face each other, the turbulent flow plate 22 is complicated. It has a structure. Therefore, although the mixing element 23 having a complicated internal structure according to the present embodiment is difficult to be formed by a general cutting process, the mixing element 23 has a complicated internal structure by applying a 3D printer capable of laminating. Even the mixing element 23 can be molded.

  Further, since the rotation restricting means 24 for preventing the mixing element 23 from rotating is provided, when the thermoplastic resin is kneaded while passing through the mixing element, which is the resin path 25 in the injection nozzle 11, the mixing element 23 is It is possible to prevent the rotation.

  FIGS. 7 and 8 show the mixing element 33 of the second embodiment. Since the second embodiment has the same structure except that the shape of the mixing element is different from that of the first embodiment, the same parts are shown. The same reference numerals are given to the components, detailed description thereof is omitted, and different points will be described below.

  As shown in FIGS. 7 and 8, the turbulent flow plate is not provided in the cylindrical portion of the mixing element 33 of the second embodiment as in the mixing element of the first embodiment. In order for the thermoplastic resin to be kneaded when passing through the inside of the mixing element 33, the resin path 25 in the mixing element 33 is intermittently formed in the direction in which the plurality of narrow portions 34 having a small cross-sectional area flow in the thermoplastic resin. Is formed. With this configuration, in addition to the kneading of the thermoplastic resin accompanying the rotation of the screw 12 in the heating cylinder 10, it is possible to generate turbulent flow in the injection nozzle 11, and the kneading of the thermoplastic resin is sufficiently performed. It can be carried out.

  FIGS. 9 and 10 show the mixing element 43 of the third embodiment. Since the third embodiment has the same structure except that the shape of the mixing element is different from that of the first embodiment, the same parts are shown. The same reference numerals are given to the components, detailed description thereof is omitted, and different points will be described below.

  As shown in FIGS. 9 and 10, a plurality of spiral spiral turbulent plates 44 are formed on the inner wall surface inside the mixing element 43 of the third embodiment with the direction of flow of the thermoplastic resin as the axial direction. The spiral turbulent plate 44 is intermittently formed in the direction in which the thermoplastic resin flows. With this configuration, in addition to the kneading of the thermoplastic resin accompanying the rotation of the screw 12 in the heating cylinder 10, it is possible to generate turbulent flow in the injection nozzle 11, and the kneading of the thermoplastic resin is sufficiently performed. It can be carried out.

  FIGS. 11 and 12 show the mixing element 53 of the fourth embodiment. Since the third embodiment has the same structure except that the shape of the mixing element is different from that of the first embodiment, the same parts are shown. The same reference numerals are given to the components, detailed description thereof is omitted, and different points will be described below.

  As shown in FIGS. 11 and 12, a resin path 25 in the mixing element 53 is formed in the mixing element 53 of the fourth embodiment so that the thermoplastic resin can be kneaded when passing through the mixing element 53. A plurality of uneven turbulent uneven portions 54 are formed on the inner wall surface. With this configuration, in addition to the kneading of the thermoplastic resin accompanying the rotation of the screw 12 in the heating cylinder 10, it is possible to generate turbulent flow in the injection nozzle 11, and the kneading of the thermoplastic resin is sufficiently performed. It can be carried out.

DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Machine stand 3 Injection unit 4 Clamping unit 5 Fixed mold (mold)
6 Movable mold (mold)
7 Toggle Link Mechanism 8 Fixed Die Plate 9 Movable Die Plate 10 Heating Cylinder 11 Injection Nozzle 12 Screw 13 Support Member 14 Hopper 15 Hopper Block 16 Supply Port 17 Heating Heater 20 Injection Portion 21 Connection Portion 22 Turbulence Plate 23 Mixing of Embodiment 1 Element 24 Rotation restricting means 25 Resin path 33 Mixing element of Example 2 34 Narrow part 43 Mixing element of Example 3 44 Spiral turbulent flow plate 53 Mixing element of Example 4 54 Turbulent uneven part 54

Claims (2)

A heating cylinder to which a thermoplastic resin is supplied; a screw rotatably provided in the heating cylinder; and an injection nozzle attached to a tip of the heating cylinder. The rotation of the screw causes the heating cylinder to enter the heating cylinder. An injection molding machine in which, after the supplied thermoplastic resin is kneaded, the kneaded thermoplastic resin is injected into a mold cavity closed through a resin path formed in the injection nozzle,
The injection nozzle, an injection unit for injecting the thermoplastic resin into the mold closed the mold cavity, is composed of a connecting portion for detachably connecting the injection-section to said heating cylinder,
In the inside of the injection part, a removable mixing element that is held so as not to move in the front-rear direction by being sandwiched between the injection part and the connecting part is provided,
The mixing element has a cylindrical cylindrical portion having a resin path formed therein, and the thermoplastic resin supplied to the injection portion is distributed into the cylindrical portion by a disturbance. comprising a turbulence plate causing the flow,
A plurality of the turbulent flow plates are provided in the direction in which the thermoplastic resin flows. The turbulent plates are formed so as to extend from the inner wall surface of the cylindrical portion, and span the inner wall surface of the cylindrical portion. The injection molding machine is formed integrally with the cylindrical portion and formed into a cross shape that partitions the resin path into a plurality of sections . A plurality of the turbulent flow plates provided in the direction in which the thermoplastic resin flows are arranged from the upstream side to the downstream side in the direction in which the thermoplastic resin flows with respect to the plurality of turbulent plates arranged in the direction in which the thermoplastic resin flows. When numbers are assigned in order of integer numbers 1, 2, 3,..., Odd-numbered turbulent plates are arranged so as to face each other, while even-numbered turbulent plates are also opposed to each other. Further, the odd-numbered turbulent flow plate and the even-numbered turbulent flow plate are arranged so as not to face each other, and the odd-numbered turbulent flow plate and the even-numbered turbulent flow plate are arranged. The position shift angle with is 45 degrees,
  The injection molding machine according to claim 1, further comprising a rotation restricting unit that prevents rotation of the mixing element when the mixing element is provided inside the injection unit.

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