JP2005305747A - Flow channel changeover device of injection machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the flow channel changeover device of an injection machine capable of easily changing over a plurality of flow channels in at least three flow channels to various forms and reducing leakage of a molten material. <P>SOLUTION: The flow channel changeover device 11 is provided to the injection machine 10 for plasticizing a molding material to inject the same as the molten material 51 and has a valve stem 15 for allowing a plurality of the flow channels to communicate with each other in at least three flow channels of the molten material 51 or cutting off them, a moving means 48 for reciprocating the valve stem 15 in the center axis direction thereof and a revolving means 49 for revolving the valve stem 15 around its center axis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molten material flow path switching device provided in an injection device that plasticizes a molding material to form a molten material and injects the molten material.

  Patent Document 1 discloses a technique in which a resin material is selectively connected to a connection passage from a screw device to a plunger device or from a plunger device to an injection nozzle by a rotary valve in a preliminary plasticizing type injection device. However, the connection of the connection passage of the resin material in Patent Document 1 is executed only by the rotation of the rotary valve, and the connection passage is formed by a groove extending in the circumferential direction provided on the outer peripheral surface of the rotary valve. . Therefore, when there are more than three connection passages or when a plurality of connection passages are simultaneously communicated or blocked, it is necessary to reduce the rotation angle of the rotary valve or to make the concave groove complicated. For this purpose, the diameter of the rotary valve has to be increased, the injection apparatus becomes larger, and the staying portion of the resin material increases, resulting in molding defects such as resin burning.

Further, Patent Document 2 discloses a technology in a pre-plasticization type injection device in which molten resin is selectively switched from a screw device to a plunger device or from a plunger device to an injection nozzle by a slide valve. . However, the switching / connection of the molten resin connecting resin passage in Patent Document 2 is executed only by reciprocating movement of the slide valve. The connecting resin passage opens to the outer peripheral surface of the slide valve and is approximately 1/3 in the circumferential direction. It is formed by a valve groove extending in the circumferential length and a valve hole extending through in the radial direction. Therefore, when there are more than three connection resin passages or when a plurality of connection resin passages are simultaneously communicated or blocked, it is necessary to extend the length of the slide valve in accordance with the increasing number of connection resin passages and connection forms. . In this case, since the slide valve is provided with a large number of valve grooves and valve holes, the slide valve is irregularly deformed as the temperature rises, so that the reciprocating movement becomes impossible or the punching occurs. In order to prevent this, the gap between the valve mounting hole of the tip block and the slide valve has to be increased, and as a result, molten resin leakage from the gap cannot be avoided.
JP-A-10-286849 (page 7-9, Fig. 1-3) Japanese Patent No. 3459214 (pages 7-8, FIGS. 2 and 6)

  The present invention has been made to solve the above-described problem, and an injection apparatus that can easily switch a plurality of flow paths in three or more flow paths in various forms and reduces leakage of molten material. An object of the present invention is to provide a flow path switching device.

  That is, the invention of claim 1 is a flow path switching device provided in an injection apparatus that plasticizes a molding material to form a molten material and injects the molten material, and includes a plurality of flow paths in three or more flow paths of the molten material. An injection comprising: a valve stem for communicating or blocking; a moving means for reciprocating the valve stem in the direction of its central axis; and a rotating means for rotating the valve stem about its central axis. The present invention relates to a flow path switching device of the apparatus.

  A second aspect of the present invention relates to the flow path switching device of the injection apparatus according to the first aspect, wherein the moving means is prevented from rotating when the valve rod is rotated by the rotating means.

  A third aspect of the present invention provides the valve stem according to the first aspect, wherein the switching of the flow path directly required for the injection molding operation is performed by driving only by either the moving means or the rotating means. The present invention relates to a flow path switching device of an injection apparatus in which both or any one of the flow path holes and the flow path grooves are formed.

  The invention according to claim 1 is a flow path switching device provided in an injection device that plasticizes a molding material to form a molten material and injects the molten material, and communicates a plurality of flow paths in three or more flow paths of the molten material. Or a shutoff valve rod, a moving means for reciprocating the valve stem in the direction of its central axis, and a rotating means for rotating the valve stem about its central axis. A plurality of flow paths can be easily switched in various forms, and leakage of the molten material can be reduced.

  According to the second aspect of the present invention, since the moving means is configured not to rotate when the valve rod is rotated by the rotating means, damage to the moving means can be prevented.

  According to a third aspect of the present invention, the flow path hole of the valve stem is arranged so that the flow path switching directly required for the injection molding operation is executed by driving only by either the moving means or the rotating means. Since both or one of the flow channel grooves is formed, the operation time for switching the flow channel can be shortened and the life of the injection device can be prolonged.

  Embodiments of the present invention will be described in detail with reference to the drawings. 1 is a front view of an injection apparatus provided with the flow path switching device of the present invention, FIG. 2 is a longitudinal sectional view of FIG. 1, and FIG. 3 is a bottom view of the injection apparatus provided with the flow path switching device of the present invention. 4 is a cross-sectional view of the state immediately before injection in FIG. 3, FIG. 5 is a perspective view of the valve rod, FIG. 6 is a vertical cross-sectional view of the injection device immediately after injection, and FIG. FIG. 8 is a longitudinal sectional view of the injection apparatus in a state where the material is changed, and FIG. 9 is a longitudinal sectional view of the injection apparatus in a state where the plasticizing means and the injection means are adjusted.

  The injection device 10 is a preliminary plasticizing type injection device that includes a flow path switching device 11, a plasticizing means 12, an injection means 13, and a nozzle portion 14. The plasticizing means 12 is supplied from the plasticizing cylinder 37 whose outer periphery is heated by a heater and the rear side (right side in FIG. 2) of the plasticizing cylinder 37 which is fitted into the inner hole of the plasticizing cylinder 37 so as to be able to rotate and reciprocate. The molding material to be kneaded while being melted in cooperation with the plasticizing cylinder 37 and conveyed forward to become the molten material 51, and the conical shape of the tip of the screw 38 fixed to the front end surface of the plasticizing cylinder 37 And a cylinder head 39 having a similar inner hole shape. The screw 38 is rotationally driven by a driving device (not shown) for plasticizing the molding material, and is driven forward for extruding the molten material. The molten material 51 is a material in which a molding material, such as a single resin or metal, or a mixture thereof, melts and has fluidity.

  The injection means 13 includes an injection cylinder 42 whose outer periphery is heated by a heater, and a molten material 51 that is removably fitted into the inner hole of the injection cylinder 42 and is supplied from the plasticizing cylinder 37 via the flow path switching device 11. And a plunger 43 for storing the same in the front thereof. The plunger 43 is driven forward by a drive device (not shown) to inject the molten material 51.

  The nozzle portion 14 is a cylindrical body that includes a hemispherical nozzle tip portion 44 and a flow path 47 that is a through hole, and a heater is attached to the outer periphery thereof. The nozzle tip 44 abuts against a mold (not shown) and guides the injected molten material 51 to the mold cavity.

  The flow path switching device 11 includes a valve body 41, a valve rod 15 fitted in a through-hole 50 provided on two opposing surfaces of the valve body 41 so as to be able to rotate and reciprocate, and the valve rod 15 in the direction of its central axis. Moving means 48 for reciprocally moving the valve rod 15 at a predetermined distance, and rotating means 49 for rotating the valve rod 15 around the central axis at a predetermined rotation angle. The valve body 41 is a parallelepiped, and the through holes 50 are drilled on the two opposite faces thereof, and the flow paths 45, 46, 47 are drilled on the other three surfaces parallel to the through holes 50 so as to communicate with the through holes 50. Has been. The plasticizing means 12 is fixed to the surface of the flow path 45 of the valve body 41 via the connecting portion 40, and the flow path 45 is extended to communicate with the plasticizing means 12. The injection means 13 is fixed to the surface of the flow path 46 of the valve body 41, and the flow path 46 is extended in diameter and communicated with the injection means 13. Further, the nozzle portion 14 is fixed to the surface of the flow path 47 of the valve body 41, and the flow path 47 extends to the nozzle tip portion 44 and opens. A heater is attached to the remaining surface facing downward of the valve body 41.

  The valve rod 15 is a round bar slightly longer than the distance between two opposing surfaces of the valve body 41, as shown in FIGS. On the outer peripheral surface of the central position in the central axis direction (length direction) of the valve stem 15, a flow channel groove 17 corresponding to approximately ¼ of the outer periphery extends and is engraved. The other end of the channel groove 17 is configured to communicate with the channel 46 when one end of the channel groove 17 communicates with the channel 45. In addition, the diameter direction is a predetermined distance away from the flow path groove 17 in the central axis direction of the valve rod 15, and the other end of the flow path groove 17 and the valve rod 15 have the same angular position on the circumference. A channel hole 16 is drilled. The gap between the valve stem 15 and the through hole 50 is 25 to 30 μm, which can be made smaller than the conventional 80 μm, and reduces the leakage of the molten material 51 from the gap within a range where no warpage occurs. I was able to. However, since there is no leakage of the molten material 51, the annular groove 18 is provided between the flow channel groove 17 and the flow channel hole 16 and in the vicinity of both end portions of the valve rod 15. The molten material 51 leaking from the flow channel groove 17 and the flow channel hole 16 is introduced into the annular groove 18, and the molten material 51 communicates with each annular groove 18 on the flow channel hole 16 side of the valve rod 15. It is discharged outward through a passage (not shown) that opens at the end face.

  As shown in FIGS. 3 and 4, the moving means 48 includes a rotating box 19 fixed to the end face of the valve stem 15 and a recess 21 of the rotating box 19 that is not movable in the axial direction by a bearing 22 and is rotatable around the axis. The engagement shaft 23 engaged with the engagement shaft 23, the double nut 24 screwed into a predetermined position of the engagement shaft 23, the rod 29 extended and fixed to the engagement shaft 23, and the penetrating rod 29 are driven reciprocally. The cylinder portion 30 to be engaged, the double nut 52 screwed to the rod 29 protruding from the cylinder portion 30, and the cylinder portion 30 supported via the intermediate seat 28 and fixed to the surface of the valve body 41 with the through hole 50. It comprises a letter-shaped mounting seat 27. The rotating box 19 has a lever 20 protruding from the side surface. The oil seal 26 inserted into the extension shaft protruding portion of the mounting seat 27 seals the hydraulic oil leaking to the rod 29 of the cylinder portion 30.

  Since the moving means 48 is configured as described above, by supplying pressure oil to the hydraulic cylinder or the like of the cylinder portion 30, the valve rod 15 is moved to a predetermined distance corresponding to the distance between the flow path groove 17 and the flow path hole 16. The distance can be reciprocated. The state shown in FIG. 4 is when the valve stem 15 is pushed into the valve body 41, and the positioning of the push-in movement of the valve stem 15 is performed by the double nut 52 screwed to the outer end of the rod 29 by the cylinder part 30. This is performed by abutting on the end face. In the state shown in the drawing, the flow channel 17 of the valve rod 15 communicates the flow channel 45 and the flow channel 46.

  On the other hand, if pressure oil or the like is supplied to the hydraulic cylinder or the like of the cylinder portion 30 on the opposite side, the valve rod 15 can be moved in the direction of pulling out from the valve body 41. At this time, the valve stem 15 is positioned in the pulling direction by the end surface of the double nut 24 on the cylinder portion 30 side coming into contact with the end surface of the mounting seat 27. Then, as shown in FIGS. 6 and 7, the flow path hole 16 of the valve rod 15 connects the flow path 46 and the flow path 47. In addition, although the positioning of the reciprocating movement of the valve rod 15 has been described as being performed by the double nuts 24 and 52, it may be performed by a stopper or a piston provided in the cylinder 30 itself.

  The rotating means 49 includes a ball joint 31 provided at the tip of the lever 20, a joint 32 connected via the ball joint 31, a rod 33 fixed to the joint 32, and a cylinder portion that drives the rod 33 forward and backward. 34, a ball joint 35 provided at the end of the cylinder portion 34 on the side without the rod 33, and a mounting seat 36 for fixing the ball joint 35 to the injection means 13.

  When the pressure oil or the like is supplied to the cylinder portion 34 and the rod 33 is advanced and retracted, the lever 20 rotates the rotation box 19 and the valve rod 15 is within an angle defined by a predetermined driving distance of the cylinder portion 34. Rotate. In this embodiment, as shown in FIGS. 1 and 2, the valve rod 15 is pushed into the forward limit position of the rod 33, so that the flow channel 45 and the flow channel 46 communicate with each other through the flow channel groove 17. doing. Further, when the rod 33 reaches the retreat limit position at the position where the valve rod 15 is pushed in, the valve rod 15 rotates counterclockwise by 90 degrees. Therefore, as shown in FIG. The flow path 47 communicates. At this time, since the engaging shaft 23 is engaged with the recess 21 of the rotating box 19 via the bearing 22, even if the rotating box 19 rotates, the moving means 48 does not rotate but only reciprocates. Can be executed. Thereby, damage to the cylinder part 30 and the oil seal 26 can be prevented.

  Further, as the moving means 48 reciprocates, the rotating box 19 approaches and separates from the valve body 41, so that the rotating means 49 connected to the lever 20 of the rotating box 19 is also displaced. The ball joint 31 and the ball joint 35 effectively act on the displacement to cause the rotation means 49 to follow.

  Next, the molding operation based on the injection apparatus 10 provided with the flow path switching device 11 of the present invention will be described. First, the rotating means 49 is set in a state where the rod 33 remains at the forward limit position (FIGS. 1 to 3). Then, when the moving means 48 is driven and the valve rod 15 is pulled out, the state becomes as shown in FIG. At this time, since the flow path 45 is blocked by the valve rod 15, a predetermined amount of the molten material 51 plasticized by the plasticizing means 12 is stored in front of the screw 38 inside the plasticizing cylinder 37. Thereafter, the moving means 48 is driven so that the valve rod 15 is pushed in, and the flow path 45 communicates with the flow path 46. Then, the screw 38 is driven forward to convey the molten material 51 by a predetermined amount forward of the plunger 43 inside the injection cylinder 42. FIG. 2 shows the situation when this process is completed.

  Subsequently, after the moving means 48 is driven and the valve rod 15 is pulled out again so that the flow path 46 communicates with the flow path 47, the plunger 43 is driven forward so that the inside of the plasticizing cylinder 37 is The molten material 51 stored in front of the screw 38 is injected and filled into a mold (not shown) in contact with the nozzle tip 44. FIG. 7 shows the situation where this process is completed.

  By repeating the above steps, an injection molding operation from plasticization to injection is directly executed. That is, the operation of the flow path switching device 11 related to this injection molding operation is performed only by the moving means 48 because the valve rod 15 has the flow path hole 16 and the flow path groove 17 configured as described above. As a result, the rotation means 49 remains fixed on one rotation side and does not operate. If the shape of either or both of the flow path hole 16 and the flow path groove 17 is changed, the operation of the flow path switching device 11 related to the injection molding operation is executed only by the rotating means 49, and the moving means 48. Can also be implemented in such a way that it remains fixed on one of its moving sides and does not operate. By being configured in this way, it is possible to shorten the operation time of the flow path switching and to prolong the life of the injection device.

  By the way, in the injection device 10, various operations are required in addition to the operation of the flow path switching device 11 directly related to the injection molding. For example, when the type or color of the molding material is changed, the unmodified molten material 51 remaining inside the plasticizing means 12 must be discharged. For this purpose, as shown in FIG. 8, the moving means 48 is driven to the position where the valve rod 15 is pushed in, the turning means 49 is driven to bring the rod 33 to the retreat limit position, and the flow channel groove 17 flows. The channel 45 and the channel 47 are communicated. This mode is also applicable when normal injection molding is performed only by the plasticizing means 12.

  Further, as another operation, in order to adjust the drive control system of the plasticizing means 12 and the injection means 13, it is necessary to block the respective flow paths. For this purpose, as shown in FIG. 9, the moving means 48 is driven to bring the valve rod 15 into the extracted position, the turning means 49 is driven to bring the rod 33 to the retreat limit position, and the flow path hole 16 flows. The channel 45 and the channel 46 are blocked. As described above, the flow path switching device 11 of the present invention can easily obtain many switching modes as compared with the flow path switching device based only on the conventional moving means or rotating means, The leakage of the molten material 51 can be reduced.

  In addition, this invention includes what can be implemented in the aspect which added various change, correction, improvement, etc. based on the knowledge of those skilled in the art. Further, it goes without saying that any of the embodiments to which the above-mentioned changes are added is included in the scope of the present invention without departing from the gist of the present invention. For example, although three channels are illustrated as communicating with the valve stem, three or more channels may be used. In addition, although the flow path communicating with the valve stem is illustrated as being at the same position with respect to the central axis direction of the valve stem, the flow paths may be provided at different positions. Furthermore, the channel hole and the channel groove provided in the valve stem may be provided with only one or both of them or the shape thereof may be changed according to the form of communication or blocking of the plurality of channels. May be. Furthermore, although the flow path switching device of the present invention is applied to a preliminary plasticizing type injection device, it is needless to say that it can be applied to other types of injection devices (such as multicolor molding machines).

It is a front view of the injection device provided with the flow path switching device of the present invention. It is a longitudinal cross-sectional view in FIG. It is a bottom view of the injection device provided with the flow path switching device of the present invention. It is a cross-sectional view of the state immediately before injection in FIG. It is a perspective view of a valve stem. It is a longitudinal cross-sectional view of the injection apparatus in the state immediately after injection. It is a longitudinal cross-sectional view of the injection apparatus in the state after the end of plasticization. It is a longitudinal cross-sectional view of the injection apparatus of the state of material change. It is a longitudinal cross-sectional view of the injection apparatus in the state at the time of adjustment of the plasticizing means and the injection means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Injection apparatus 11 Flow path switching device 12 Plasticizing means 13 Injection means 14 Nozzle part 15 Valve rod 16 Channel hole 17 Channel grooves 45, 46, 47 Channel 48 Moving means 49 Turning means 51 Molten material

Claims (3)

A flow path switching device provided in an injection device for plasticizing a molding material to form a molten material and injecting it,
A valve rod for communicating or blocking a plurality of flow paths in three or more flow paths of the molten material; a moving means for reciprocating the valve stem in the direction of its central axis; and the valve stem is rotated about its central axis. A flow path switching device for an injection device, characterized by having a rotating means for moving.   The flow path switching device for an injection apparatus according to claim 1, wherein the moving means is not rotated when the valve rod is rotated by the rotating means.   Either or both of the channel hole and the channel groove of the valve rod are so configured that the switching of the channel directly required for the injection molding operation is performed by driving only one of the moving unit and the rotating unit. The flow path switching device for an injection apparatus according to claim 1, wherein one of the two is formed.

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