JP4779007B2 - Injection device screw - Google Patents

Description

  The present invention relates to a screw of an injection device, and more specifically, a plurality of grooves are formed around a screw flight to smoothly transfer and inject a resin containing long fibers (glass fibers). The present invention relates to the screw of the injection device.

  In general, an injection apparatus is an apparatus for injecting a resin into a mold manufactured according to the shape of a product to be molded. The injection device melts the solid resin in a solid state by mechanical energy generated by the rotation of a screw disposed in the barrel and thermal energy generated by a heater attached to the outside of the barrel. A molten resin is poured into a mold manufactured together and solidified to obtain a product having a desired shape.

  At this time, the screw disposed in the barrel prevents the backflow of the resin that is caused when the molten resin is injected into the mold and the screw portion for transferring and melting the solid resin in the solid state. And a screw head portion.

  As a result, the particulate resin supplied from the hopper is put into a barrel equipped with a heater, and in the barrel, the shear heat generated by the rotation of the screw while the screw connected to the hydraulic motor or the electric motor rotates. The resin is melted by the heat of the heater. Thereafter, the molten resin passes through the screw head and accumulates on the front stage of the head.

  At this time, the screw moves the resin supplied from the hopper toward the screw head while moving backward when the molten resin is pushed in, so that the resin continuously accumulates on the front stage of the screw head. The molten resin is continuously piled up to a predetermined amount in the front part of the screw head, and when the measurement is completed, the screw stops rotating and is advanced in the axial direction at a pressure and speed suitable for the molding conditions, The molten resin is pushed into the mold from the outlet of the barrel.

  The conventional injection apparatus will be described in more detail with reference to FIG. 1 schematically showing the following.

  As shown in FIG. 1, the conventional injection device (1) basically includes a barrel (10) and a screw (20) rotatably disposed inside the barrel (10).

  One side of the barrel (10) is provided with a hopper (11) that allows solid resin particles to be introduced into the barrel (10).

  The screw (20) includes a screw head (21) positioned on the front side, a body part (22) coupled to the screw head (21), and a distance along the longitudinal direction of the body part (22). A plurality of spiral flights (23) are formed.

  Further, a check ring (24) as a movable backflow preventing member is coupled to the front of the body portion (22), that is, the screw head (21) side.

  Further, as shown in FIG. 2, the body part (22) includes a supply part (L1) for receiving and transferring a solid resin having a relatively small diameter in order from the place where the resin is transferred; Inclined upward in the direction of pushing the resin through the supply part (L1), and formed so as to have the same diameter as the compression part (L2) whose diameter increases and the end of the compression part (L2) It is divided into three areas of the measuring section (L3).

  Further, the distance (gap) between the flight (23) and the inner surface of the barrel (10) is set to about 1 mm, and the particulate resin in a solid state is charged into the barrel (10) from the hopper (11), In the process of passing through the supply section (L1), the compression section (L2), and the measurement section (L3) of the body section (22) of the screw (20) in order, the helical flight (23) of the body section (22) and It is transferred through a passage formed by a gap with the inner surface of the barrel (10). However, when the resin to be added is, for example, a synthetic resin containing long fibers, the inner surface of the screw (20) and the barrel (10) due to the properties of the long fibers, i.e., the insoluble and soft and hard properties. Or clogged into the gap, and a high torque was generated when the screw (20) was rotated, which caused a failure.

  The frequency of such failures increases in proportion to the amount of long fibers.

  Here, the above-mentioned long fiber means a glass fiber, and a fiber having a diameter of 0.005 mm to 0.015 mm and a length of 10 mm or more is usually referred to as a long fiber.

  The technology for producing such long fibers without breaking along the way is advancing, and the length of the fiber material is becoming longer and longer. This has the advantage of greatly improving the physical properties of the synthetic resin itself.

  The strength of the synthetic resin product molded using the long fiber-containing resin may exceed the strength of the metal.

  However, as described above, the molding of the synthetic resin using long fibers shortens the life of the screw (20) and the barrel (10), and deteriorates the fluidity of the molten resin at the time of molding, resulting in a large load. There is a problem of generating.

  Therefore, the present invention has been made to solve the problems of the prior art as described above, and its purpose is to inject the resin containing long fibers in the longitudinal direction of the screw. It is an object of the present invention to provide a screw for an injection device that can smoothly perform an injection operation without being loaded by a long fiber when being transported by a flight along the line.

  The screw of the injection device according to the present invention for achieving the above-described object is rotatably disposed inside the barrel into which the resin is charged, and is moved along the longitudinal direction so as to transfer the charged resin. A screw of an injection device having a plurality of spiral flights, wherein a plurality of grooves are formed at intervals along the periphery of the flight.

  The groove may be at least one of a horizontal groove and an inclined groove.

  The horizontal groove and the inclined groove may have at least one cross-sectional shape selected from a quadrangle, a semicircle, and a triangle.

  Further, the groove is formed by alternately forming horizontal grooves and inclined grooves.

  The length of the groove may be in the range of 1 to 5 times the flight width.

  The height of the groove may be in the range of 0.3 to 0.7 times the height from the body of the screw to the upper end of the flight.

  The length of the groove may be in the range of 0.5 to 4 times the height from the body of the screw to the upper end of the flight.

  In this way, in the present invention, by forming a plurality of grooves around the flight of the screw constituting the injection device, the resin is smoothly transferred without applying a load when the resin containing long fibers is injected. It has the effect of preventing carbonization of the resin due to residence.

  Hereinafter, the screw of the injection device according to the embodiment of the present invention will be described in detail with reference to the drawings.

  In this embodiment, the same reference numerals are used for the same components as those in the above-described prior art, and the detailed description thereof is omitted, and new components are assigned new symbols. The configuration will be described.

  FIG. 3 is a perspective view showing an example of a flight formed in a spiral shape on the body of the screw according to the embodiment of the present invention.

  As shown in the figure, an injection apparatus according to an embodiment of the present invention basically includes a barrel (10) for transferring charged resin, like the conventional injection apparatus (1) shown in FIG. It has a screw (20) that is rotatably disposed inside the barrel (10) and that transfers the charged resin.

  The screw (20) is formed in a spiral shape along the longitudinal direction of the screw head (21), a body part (22) coupled to the screw head (21) for transferring resin, and the body part (22). Flight (23).

  Here, as shown in FIG. 3, the flight (23) according to the embodiment of the present invention has a structure in which a plurality of grooves (30) are formed at intervals in the circumferential direction along the periphery thereof.

  The groove (30) includes a horizontal groove (31, see FIG. 3) parallel to the axial direction of the body part (22) and an inclined groove (32 inclined with respect to the axial direction of the body part (22). , See FIG. 5). FIG. 3 shows a configuration in which all the grooves (30) formed in the flight (23) are horizontal grooves (31).

  Meanwhile, the cross-sectional shapes of the horizontal groove (31) and the inclined groove (32) can be variously changed, and the horizontal groove (31) according to the embodiment of the present invention is shown in FIGS. 6 (a) and 6 (b), a quadrangular groove (31a), a semicircular groove (31b), and a triangular groove (31c) (here, the triangle is a groove that preferably forms a fan shape from the shape on the drawing). It is sufficient if it has a cross-sectional shape.

  However, the cross-sectional shape of the groove is not limited thereto, and can be deformed into various shapes.

  Also, the arrangement state of the grooves (30) according to the embodiment of the present invention can be variously modified. That is, other forms of grooves can be formed alternately. For example, as shown in FIG. 5, square grooves (31a) and inclined grooves (32) can be formed alternately.

  Further, as shown in FIG. 2, the groove (30) has a flight (23) formed in the compression part (L2) of the body part (22) and a flight (23) formed in the weighing part (L3). What is necessary is just to form a part.

  Moreover, as shown in FIG. 7, the length (d1) (d2) of the said groove | channel (30) should just have the length of the range of 1-5 times with respect to the width (W) of a flight (23). .

  More specifically, as shown in FIG. 7, in the case of the horizontal groove (31), the length (d1) of the horizontal groove (31) and the width (W) of the flight (23) ) And the inclined groove (32) has a length (d2) up to five times the width (W) of the flight (23), and the inclined groove It can be formed to incline long.

  Further, as shown in FIG. 4, the height of the groove (30) with respect to the height (or the depth) (H) from the screw body (22) to the upper end of the flight (23) can be reduced. The depth (H1) may have a range of 0.3 times to 0.7 times.

  The length (d1) (d2) as the width of the groove (30) is 0.5 times to the height (H) from the screw body (22) to the upper end of the flight (23). What is necessary is just to have the range of 4 times.

  The number of grooves (30) is preferably in the range of 4 to 24 per pitch of the flight (23).

  Further, as shown in FIG. 6A of the attached exemplary view, when the semicircular groove (31b) is formed, the same as the rectangular groove (31a) as shown in FIG. 4 above. In addition, the height (or depth) (H1) of the groove (30) with respect to the height (H) from the screw body (22) to the upper end of the flight (23) is 0.3 times to 0. It suffices to have a range of 7 times.

  Further, the length as the width of the semicircular groove (31b) is also 0.5 times the height (H) up to the upper end of the flight (23), as is the case with the square groove (31a). It is preferable to be in the range of 4 times.

  The conditions for the square groove (31a) and the semicircular groove (31b) (relative standard between height (H) and (H1)) are triangular grooves (31c) as shown in FIG. 6 (b). The same applies to.

  According to the present invention having such a configuration, since the plurality of grooves (30) are formed in the screw flight (23), the long fibers are smoothly transferred without being accumulated.

  Note that if the height (H1) of the groove (30) is too large, the resin may flow backward or generate gas or the like, so it is desirable to form the groove under the above conditions.

  Thus, according to the present invention, the groove (30) formed in the screw flight (23) causes damage to the screw (20) and the barrel (10) due to long fibers (that is, wear due to long fibers, overload, coating surface damage). Damage) and the like, and an excessive load on the injection device can be prevented.

  The screw of the injection device according to the present invention can be used for an injection device such as resin molding.

It is sectional drawing which shows the conventional injection apparatus. It is a figure which shows the structure of the screw of the conventional injection device. FIG. 3 is an enlarged perspective view of a portion of a flight structure according to an embodiment of the present invention shown as A in FIG. 2. It is a longitudinal cross-sectional view which shows the structure of the flight concerning one Example of this invention. It is an expansion perspective view which shows the structure of the screw flight concerning the other Example of this invention. (A), (b) is a longitudinal cross-sectional view which shows the other structure of the groove | channel of the screw flight concerning the Example of this invention. It is a figure for demonstrating the relationship between the groove length of the screw flight concerning the Example of this invention, and the width of a flight, Comprising: It is the figure which looked at the flight shown in FIG. 5 from the front.

Explanation of symbols

d1, d2: Length H, H1: Height W: Width 1: Injection device 10: Barrel 20: Screw 21: Screw head 22: Body part 23: Flight 30: Groove 31: Horizontal groove 32: Inclined groove 31a : Square groove 31b: Semi-circular groove 31c: Triangular groove

Claims (5)

A screw of an injection device that is rotatably arranged inside a barrel into which resin is charged and has a plurality of helical flights along the longitudinal direction so as to transfer the charged resin,
A plurality of grooves are formed at intervals along the periphery of the flight ,
A screw for an injection apparatus, wherein the groove is formed by alternately forming a horizontal groove and an inclined groove . The screw of the injection apparatus according to claim 1 , wherein the horizontal groove and the inclined groove have at least one cross-sectional shape selected from a square, a semicircle, and a triangle.   The screw of the injection device according to claim 1, wherein the length of the groove is in the range of 1 to 5 times the width of the flight.   2. The injection device according to claim 1, wherein the height of the groove is in a range of 0.3 to 0.7 times the height from the body of the screw to the upper end of the flight. Screw.   The screw of the injection device according to claim 1, wherein the length of the groove is in the range of 0.5 to 4 times the height from the body of the screw to the upper end of the flight. .

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