JP6068926B2 - Injection molding nozzle - Google Patents

Description

  The present invention relates to an injection molding nozzle.

  Conventionally, as an injection molding nozzle, a nozzle body that is formed in a cylindrical shape and is provided with an introduction port through which fluid is introduced at one end side and a discharge port through which the fluid introduced at the other end side is led out, and the nozzle A fluid mixing element as a plurality of elements arranged between the inlet and outlet of the main body and introducing and kneading the fluid introduced into the nozzle body from the inlet through a fluid passage as a plurality of element holes; Are known (for example, see Patent Document 1).

  In this injection molding nozzle, the element has a structure in which two fluid passages each having a spiral blade provided therein are communicated with each other upstream and downstream of one fluid passage. The two upstream fluid passages and the two downstream fluid passages are arranged out of phase with respect to the center of one fluid passage. By disposing a plurality of elements configured in this manner in the nozzle body, the fluid flowing through the nozzle body is kneaded by repeatedly performing aggregation and division.

Japanese Patent Publication No.53-36182

  By the way, the injection molding nozzle as described above is arranged between the injection molding machine and the mold, introduces the fluid injected from the injection molding machine from the introduction port, kneads the fluid with a plurality of elements, and guides the fluid. Inject from the outlet into the mold.

  However, when molding at an injection peak pressure close to the maximum injection pressure of the injection molding machine, the injection molding nozzle as in Patent Document 1 has a large pressure loss, so that the necessary injection pressure increases. Therefore, there is a possibility that the same injection molding machine cannot be used. Therefore, it has been necessary to increase the size of the injection molding machine in order to obtain the necessary injection pressure.

  Then, this invention aims at provision of the nozzle for injection molding which can suppress the enlargement of an injection molding machine.

According to the first aspect of the present invention, there is provided a nozzle body provided with an introduction port through which a fluid is introduced at one end side and a discharge port through which the fluid introduced at the other end side is led out. An injection molding nozzle provided with a plurality of elements disposed between the inlet and the outlet and introduced into the nozzle body from the inlet through a plurality of element holes. In the nozzle body, there is provided pressure increase suppression means for suppressing an increase in the injection pressure of the fluid introduced from the introduction port, and the pressure increase suppression means has a length of the element in the element hole. 0.64 times or more and 1.6 times or less with respect to the diameter of the pressure increase suppression means, the pressure rise suppression means, the injection pressure of the fluid circulated from the introduction port to the outlet through the plurality of elements, the introduction Directly from the mouth It is characterized by being substantially equal to the injection pressure of the fluid flowing through the outlet .

  In this injection molding nozzle, since the pressure increase suppression means for suppressing the increase in the injection pressure of the fluid introduced from the introduction port is provided in the nozzle body, the fluid introduced from the introduction port by the pressure increase suppression means is provided. The rise in injection pressure can be suppressed, and the pressure loss of the fluid flowing through the nozzle body can be reduced. Therefore, in such an injection molding nozzle, an increase in the injection pressure can be suppressed by the pressure increase suppression means, so that an increase in the size of the injection molding machine can be suppressed.

  Further, in this injection molding nozzle, the pressure rise suppression means is set such that the length of the element is not less than 0.64 times and not more than 1.6 times the diameter of the element hole. The cross-sectional area of the flow path can be increased efficiently, and the pressure loss of the fluid flowing through the nozzle body can be reduced (the element length is 0.64 times or more and 1.1 times the element hole diameter) It is more preferable to set it below.

  In this injection molding nozzle, the pressure rise suppression means makes the injection pressure of the fluid flowing from the inlet port through the plurality of elements to the outlet port substantially equal to the injection pressure of the fluid flowing from the inlet port directly to the outlet port. Therefore, the pressure loss can be made substantially equal to that of an open nozzle in which a plurality of elements are not provided in the nozzle body by the pressure increase suppressing means. In addition, the fluid can be kneaded in the nozzle body while having a pressure loss substantially equal to that of the open nozzle.

According to a second aspect of the present invention, there is provided a nozzle main body formed in a cylindrical shape and provided with an introduction port through which fluid is introduced at one end side and a discharge port through which the fluid introduced at the other end side is led out. An injection molding nozzle provided with a plurality of elements disposed between the inlet and the outlet and introduced into the nozzle body from the inlet through a plurality of element holes. In the nozzle body, there is provided pressure increase suppression means for suppressing an increase in the injection pressure of the fluid introduced from the introduction port, and the pressure increase suppression means has a length of the element in the element hole. The diameter of the element is set to be 2.5 times or more of the diameter of the introduction port.

  In this injection molding nozzle, the pressure rise suppression means is set to have a diameter of the element that is 2.5 times or more the diameter of the inlet, so that the flow passage cross-sectional area of the element when the fluid flows through the element is increased. The pressure loss of the fluid flowing through the nozzle body can be reduced.

  According to the present invention, it is possible to provide an injection molding nozzle capable of suppressing an increase in size of an injection molding machine.

It is sectional drawing of the nozzle for injection molding which concerns on 1st Embodiment of this invention. It is a front view of the element of the nozzle for injection molding concerning a 1st embodiment of the present invention. It is a table | surface which shows the injection pressure of the Example in the nozzle for injection molding which concerns on 1st Embodiment of this invention, and a comparative example. It is a side view of the nozzle for injection molding which concerns on 2nd Embodiment of this invention. It is a front view of the element of the nozzle for injection molding concerning a 2nd embodiment of the present invention. It is a table | surface which shows the injection pressure per element of the Example in the nozzle for injection molding which concerns on 2nd Embodiment of this invention, and a comparative example. It is a figure which shows the range which can reduce the injection pressure, showing the relationship between the nozzle for injection molding, the ratio of element length and element diameter. It is sectional drawing of the nozzle for injection molding which concerns on the 1st reference example of this invention. It is a front view of the element of the nozzle for injection molding concerning the 1st reference example of the present invention. It is a table | surface which shows the injection pressure of the Example in the nozzle for injection molding which concerns on the 1st reference example of this invention, and a comparative example. It is a figure which shows the relationship between the element hole number and flow-path cross-sectional area of the Example and comparative example in the nozzle for injection molding which concern on the 1st reference example of this invention. It is a table | surface of the 2nd reference example which shows the change of the pressure loss per element by the change of element length and element diameter. It is a table | surface of the 2nd reference example which shows the change of the pressure loss per element by the change of land length.

  The injection molding nozzle according to the embodiment of the present invention will be described with reference to FIGS. 8 to 13 are reference examples of the present invention.

(First embodiment)
1st Embodiment is described using FIGS. 1-3.

  The injection molding nozzle 1 according to the present embodiment is provided with an introduction port 3 that is formed in a cylindrical shape and into which fluid is introduced on one end side, and an outlet port 5 that leads out the fluid introduced on the other end side. A fluid that is disposed in the nozzle body 7 and between the inlet 3 and outlet 5 of the nozzle body 7 and is introduced into the nozzle body 7 from the inlet 3 is introduced from a plurality of element holes 9 and kneaded. A plurality of elements 11 are provided.

  In the nozzle body 7, pressure increase suppression means 13 that suppresses an increase in the injection pressure of the fluid introduced from the inlet 3 is provided.

  In the present embodiment, the pressure rise suppressing means 13 has two element holes 9.

  Further, the pressure rise suppressing means 13 is configured to cause the injection pressure of the fluid that is circulated from the inlet 3 to the outlet 5 via the plurality of elements 11, and the open nozzle that is circulated directly from the inlet 3 to the outlet 5. It should be approximately the same as the injection pressure of the fluid to be circulated.

  As shown in FIGS. 1 and 2, the nozzle body 7 is formed in a cylindrical shape and includes an inlet 3 and an outlet 5. The introduction port 3 is provided on one end side of the nozzle body 7, and the outside of the nozzle body 7 is opened so as to communicate the outside and the inside of the nozzle body 7. An injection molding machine (not shown) for injecting a heat-melted molding resin material as a fluid is disposed on the introduction port 3 side. The molding resin material injected from this injection molding machine is introduced into the nozzle body 7 from the inlet 3 at a predetermined injection pressure, and is led out from the outlet 5. The flow path extending from the introduction port 3 to the inside of the nozzle body 7 is formed in a taper shape so as to expand toward the inside of the nozzle body 7, and is a molded resin material introduced from the introduction port 3. The pressure loss is reduced.

  The outlet port 5 is provided on the other end side of the nozzle body 7 and communicates the outside and the inside of the nozzle body 7. A nozzle chip 15 is assembled on the outlet 5 side, and a molding resin material is injected into the mold 17 through the nozzle chip 15. In addition, the pressure loss of the molding resin material is further reduced by shortening the length of the tip of the nozzle chip 15 on the mold 17 side.

  The molding resin material introduced from the inlet 3 and led out from the outlet 5 may be colored by mixing with other coloring materials. In such a case, there is a possibility that an appearance defect such as color unevenness may occur in an open nozzle in which nothing is interposed between the inlet 3 and the outlet 5 of the nozzle body 7. Therefore, a plurality of elements 11 for kneading a plurality of molten molding resin materials are arranged between the inlet 3 and the outlet 5 of the nozzle body 7.

  The element 11 is arranged in parallel (in this case, six) between the inlet 3 and the outlet 5 and includes a flow dividing section 19 and a mixing section 21. The flow dividing portion 19 is composed of a plurality of element holes 9 communicating from the inlet 3 side to the outlet 5 side of the element body 23. Inside the element hole 9, a torsion blade 25 in which the base end on the introduction port 3 side and the base end on the lead-out port 5 side are twisted by 180 ° is disposed. For this reason, the molding resin material which distribute | circulates the one element hole 9 is divided into two. The molding resin material that has circulated through the plurality of element holes 9 is mixed in the mixing unit 21.

  Further, a plurality (six in this case) of elements 11 are arranged in parallel between the inlet 3 and the outlet 5, and two element holes 9 are provided in the element body 23. The two element holes 9 are arranged at equal intervals from the center of the element main body 23 with an outer diameter inscribed in the inner diameter of the element main body 23 and at an interval of 180 ° in the circumferential direction of the element main body 23. In addition, the element holes 9 and 9 provided in the adjacent elements 11 and 11 are arranged so as to be shifted by 90 ° in the rotation direction when the center of the element body 23 is the rotation axis. By arranging the element holes 9 in this manner, the kneading efficiency of the molded resin material can be improved.

  The mixing portions 21 are provided on the inlet 3 side and the outlet 5 side of the element body 23, respectively, and communicate with the inlet and outlet of the element hole 9. The mixing unit 21 joins and mixes the molding resin material that has circulated through the plurality of element holes 9 (the molding resin material introduced from the introduction port 3 in the element 11 closest to the introduction port 3), and mixes the mixture to the outlet port 5 side. The molded resin material mixed into the plurality of element holes 9 of the element 11 positioned (the outlet 11 in the element 11 closest to the outlet 5) is led out.

  The molded resin material is kneaded by repeatedly flowing the molded resin material through the flow dividing section 19 and the mixing section 21. The division number N of the molding resin material flowing through the plurality of elements 11 is one when the number of elements is n, the first inflow layer (mixing portion 21 closest to the inlet 3) is N0, and the number of element holes is H. Since the element hole 9 is divided into two, N = N0 × (2 × H) n. For this reason, in the conventional injection molding nozzle with a large pressure loss, two element holes 9 are provided in one element 11, and the number of divisions per element is two.

  Therefore, the pressure increase suppression means 13 for suppressing the increase in the injection pressure of the molding resin material introduced from the introduction port 3 provided in the nozzle body 7 is set to the number of element holes 9 in one element 11. . The number of element holes 9 in this one element 11 is set to two. In the number of the element holes 9, the kneading efficiency is improved by increasing the number of divisions, and the pressure loss is reduced by increasing the flow path cross-sectional area of the molded resin material.

  Further, in the injection molding nozzle 1 according to the present embodiment, the pressure rise suppression means 13 is set such that the diameter D1 of the element 11 is 2.5 times or more the diameter D2 of the inlet 3.

  In such an injection molding nozzle 1, the pressure increase suppression means 13 that suppresses the increase in the injection pressure of the molding resin material introduced from the introduction port 3 provided in the nozzle body 7 includes the element 11 in one element 11. The diameter D1 is set. The diameter D1 of the element 11 is set to 2.5 times or more the diameter D2 of the introduction port 3. With such a diameter D1 of the element 11, the flow passage cross-sectional area of the molded resin material is increased, and the injection pressure can be made substantially equal to the injection pressure of the open nozzle.

  In order to reduce the pressure loss of the injection pressure of the molding resin material, it is effective to reduce the length L1 of one element 11 and the land lengths L2 and L3 of the inlet 3 and outlet 5. This is because when the molding resin material flows through the nozzle body 7, the contact distance between the molding resin material and each member is shortened, and the resistance to the molding resin material is reduced. For this reason, in the injection molding nozzle 1, the length L1 of the element 11 and the land lengths L2 and L3 of the inlet 3 and outlet 5 are reduced to such an extent that the kneadability is not lowered.

  In such an injection molding nozzle 1, the pressure rise suppression means 13 is set so that the diameter D 1 of the element 11 is 2.5 times or more than the diameter D 2 of the introduction port 3. 11 can be increased, and the pressure loss of the fluid flowing through the nozzle body 7 can be reduced.

  The injection molding nozzle according to the first embodiment of the present invention will be described in detail using the following examples.

(Example)
In each example and comparative example 1, the number of element holes for one element was 2, and the number of elements to be arranged in the nozzle body was 6.

  Comparative Example 2 is an open nozzle in which no element is arranged between the inlet and the outlet.

  Furthermore, the diameter D2 of the inlet is 8 (mm), the element diameter D1 is 19 (mm) in Examples 1 to 3, 20 (mm) in Example 4, and 16 (mm) in Comparative Example 1. It was.

  The length L1 of the element was 10 (mm) in Examples 1, 2, and 4, 30 (mm) in Example 3, and 15.5 (mm) in Comparative Example 1.

  Further, the total land length L2, L3 of the inlet and outlet is 25 (mm) in Examples 1, 3, and 4, 30 (mm) in Example 2, and 50 (mm) in Comparative Example 1. In Comparative Example 2, it was 95 (mm).

  In each example and each comparative example, the injection pressure (MPa) was measured when the injection speed of the injection molding machine was 20, 50, 80 (mm / sec). The results are shown in the table of FIG.

  As is apparent from the table, each of the examples according to the present invention had an injection pressure substantially equivalent to that of the comparative example 2 which is an open nozzle.

  On the other hand, in Comparative Example 1 having an element diameter D1 less than 2.5 times the inlet diameter D2, the injection pressure was much higher than that of Comparative Example 2 by about 60%.

  From this, it can be seen that by increasing the diameter D1 of the element, it is possible to increase the flow passage cross-sectional area of the fluid in the element and to suppress the increase in injection pressure.

  Therefore, by setting the element diameter D1 to be 2.5 times or more the introduction port diameter D2, the injection molding nozzle can be made substantially equal to the injection pressure of the open nozzle and can sufficiently knead the fluid. It can be seen that it can be obtained.

  From the above results, in the case of the present invention (Example), it is possible to obtain an injection molding nozzle that can suppress an increase in the injection pressure of the fluid introduced from the introduction port. On the other hand, when the present invention is not satisfied (comparative example), an injection molding nozzle that is not very attractive is obtained.

(Second Embodiment)
A second embodiment will be described with reference to FIGS.

  In the injection molding nozzle 101 according to the present embodiment, the pressure rise suppression means 103 is set such that the length L1 of the element 105 (see FIG. 1) is 0.64 times or more and 1.6 times or less than the diameter D3 of the element hole 9. (As described later, it is more preferable that the length of the element is set to 0.64 times or more and 1.1 times or less with respect to the diameter of the element hole).

  It should be noted that the same components as those of the first embodiment are denoted by the same reference numerals, and the description of the configuration and function will be omitted with reference to the other embodiments. The effect achieved is the same.

  As shown in FIGS. 4 and 5, a plurality (six in this case) of the elements 105 are arranged in parallel between the inlet 3 (see FIG. 1) and the outlet 5 (see FIG. 1). The element 105 is provided with two element holes 9. The two element holes 9 have an outer diameter inscribed in the inner diameter of the element 105 at equal intervals from the center of the element 105, and are arranged at intervals of 180 ° in the circumferential direction of the element 105. In addition, the element holes 9 and 9 provided in the adjacent elements 105 and 105 are arranged so as to be shifted by 90 ° in the rotation direction when the center of the element 105 is the rotation axis. The inner diameter of the element 105 is the diameter D1 of the element 105.

  The injection molding nozzle 101 having such an element 105 is disposed on the inner peripheral side of a locating ring insertion port 211 provided in a fixed plate 209 of the injection molding machine. The locating ring insertion port 211 is arranged with the central part of the nozzle body 207 aligned with the central part, and the mold 17 (see FIG. 1) fixed to the fixed plate 209 of the injection molding machine on the outlet port 5 side. A mold member such as is inserted and fixed. By inserting the mold member into such a locating ring insertion port 211, the center position of the mold member and the nozzle body 207 is aligned, and the molding resin material injected by the cylinder 213 of the injection molding machine is used for injection molding. It is kneaded through the nozzle 201 and injected into the mold member.

  Here, the size of the injection molding machine generally applied is 300 tons or less, and the maximum value of the diameter D4 of the locating ring insertion port 211 at this time is 120 (mm). For this reason, the maximum value of the diameter D1 of the element 203 is set to 50.5 (mm).

  This means that the outer diameter of the nozzle body 207 is at most twice the diameter D1 of the element 105 (2 × 50.5 = 101 (mm)), and the thickness of the heater disposed on the outer periphery of the nozzle body 207 is 8 (mm). ) Is required, and the clearance between the nozzle body 207 and the locating ring insertion port 211 is 10 mm, and all the total values (101 + 8 + 10 = 119 (mm)) are the maximum value of the diameter D4 of the locating ring insertion port 211 This is so as not to exceed 120 (mm).

  The maximum value of the diameter D3 of the element hole 9 is set to 25 (mm) with respect to the diameter D1 of the element 105 of 50.5 (mm). This is because two element holes 9 are provided for the element 105 and the clearance between the element holes 9 and 9 is at least 0.5 (mm), so that 25 × 2 + 0.5 = 50.5 (mm). It is.

  On the other hand, when the size of the injection molding machine is 300 tons, the maximum length of the nozzle body 207 that can be installed is 200 (mm). Six elements 105 are accommodated in the nozzle body 207. For this reason, the maximum value of the length L1 (see FIG. 5) per element 105 takes into account the inlet 3 (see FIG. 1), the outlet 5 (see FIG. 1), or other clearances. , 20 (mm) is set.

  In consideration of these maximum values, the pressure increase suppressing means 103 for suppressing the increase in the injection pressure of the molding resin material introduced from the introduction port 3 provided in the nozzle body 207 includes the length L1 of the element 105 and the element hole. The ratio (L1 / D3) with the diameter D3 of 9 is set.

  Specifically, in the pressure rise suppression means 103, the length L1 of the element 105 is set to be not less than 0.64 times and not more than 1.6 times (L1 / D3 = 0.64 to 1.60) with respect to the diameter D3 of the element hole 9. By setting the ratio (L1 / D3) between the length L1 of the element 105 and the diameter D3 of the element hole 9 as described above, the flow passage cross-sectional area of the molding resin material in the element 105 is efficiently increased, and the inside of the nozzle body 207 is increased. The pressure loss of the molding resin material that circulates can be reduced.

  In such an injection molding nozzle 101, the pressure rise suppression means 103 is set such that the length L1 of the element 105 is set to 0.64 times or more and 1.6 times or less with respect to the diameter D3 of the element hole 9, so that the inside of the element 105 is fluidized. Can be efficiently increased, and the pressure loss of the fluid flowing through the nozzle body 207 can be reduced.

  It is more preferable that the length of the element is set to be 0.64 times or more and 1.1 times or less with respect to the diameter of the element hole.

  The injection molding nozzle according to the second embodiment of the present invention will be described in detail using the following examples.

(Example)
In each example and each comparative example, the number of element holes for one element was 2, and the number of elements arranged in the nozzle body was 6.

  In each example and each comparative example, the length L1 of the element was 16 (mm).

  Further, the diameter D3 of the element hole is set to 10 (mm) in the first embodiment, 11 (mm) in the second embodiment, 12 (mm) in the third embodiment, and 13 (mm) in the fourth embodiment. In Example 5, 14.5 (mm), in Example 6, 15 (mm), in Example 7, 20 (mm), in Example 8, 25 (mm), and in Comparative Example 1, 8 (mm). In Example 2, it was 9 (mm), and in Comparative Example 3, it was 35 (mm).

  In each Example and each Comparative Example, PBT resin was used as the resin, and the injection pressure (MPa) per element when the injection rate was 26.5 (cm 3 / sec) was measured. The results are shown in the table of FIG. FIG. 6 also shows the ratio (L1 / D3) between the element length L1 and the element hole diameter D3 and the element diameter D1.

Example 8 according to the present invention has a very small injection pressure together with Comparative Example 3, but the locating ring insertion port having a diameter D4 of the maximum value 120 (mm) in the diameter of the element hole of Comparative Example 3 In Example 8, which can be arranged, was set as the upper limit value of the diameter of the element hole. (Please confirm.)
Example 1 according to the present invention has a diameter of an element hole (element) that can be disposed in a locating ring insertion port having a diameter D4 of 120 mm or less at the maximum value together with Comparative Examples 1 and 2. However, in the case of Comparative Examples 1 and 2, there is a risk of exceeding the maximum injection pressure, which is the upper limit of the performance of the injection molding machine, depending on the shape of the molded product and the resin, and molding is impossible at the upper limit of the performance of the injection molding machine. . For this reason, Example 1 in which the injection pressure per element was 2.9 (MPa) or less was set as the lower limit.

  As can be seen from the above, each of the examples according to the present invention can be arranged in the locating ring insertion port, and the injection pressure is reduced as compared with the conventional comparative examples 1 and 2.

  On the other hand, in each comparative example in which the element length L1 is not set to be not less than 0.64 times and not more than 1.6 times (L1 / D3 = 0.64 to 1.60) with respect to the element hole diameter D3, The injection pressure per element exceeds 2.9 (MPa), and in Comparative Example 3, it cannot be disposed at the locating ring insertion port.

  Therefore, by setting the element length L1 to be not less than 0.64 times and not more than 1.6 times (L1 / D3 = 0.64 to 1.60) with respect to the element hole diameter D3, the fluid cross-sectional area of the fluid in the element can be efficiently It can be seen that the increase in injection pressure can be suppressed.

  It is more preferable that the length of the element is set to be 0.64 times or more and 1.1 times or less with respect to the diameter of the element hole.

  From the above results, in the case of the present invention (Example), it is possible to obtain an injection molding nozzle that can suppress an increase in the injection pressure of the fluid introduced from the introduction port. On the other hand, when the present invention is not satisfied (comparative example), an injection molding nozzle that is not very attractive is obtained.

  Next, with reference to FIG. 7, a description will be given of the injection pressure distribution in which the injection pressure when the ratio L / D between the element length L and the element diameter D is changed, with the flow path diameter d of the element as the horizontal axis.

  In the figure, the range of the ratio L / D of the flow path diameter φ8 is 0, 30 to 21, 21, the range of the ratio L / D of the flow path diameter φ10 is 0, 98 to 0, 24, and the flow path diameter φ14,5. The range of the ratio L / D is 1,00 to 0,20, and the range of the ratio L / D of the flow path diameter φ25 is 0,99 to 0,20.

  Here, the range in which the injection pressure per element satisfies 2.9 MPa or less is such that the ratio L / D is 1,21 (point a) when the flow path diameter is φ8, and the flow path diameter is φ10. When the ratio L / D is 0,78-0,88 (b1 point to b2 point) and the flow path diameter is φ14,5, the ratio L / D is 0,40-0,67 (c1 point to c2 point), In the case of the channel diameter 25, the ratio L / D is 0, 20 to 0, 40 (e1 point to e2 point).

  Therefore, it can be seen that the range in which the injection pressure can be reduced is a range (shaded portion in FIG. 7) surrounded by the above a, b1, b2, c1, c2, e1, and e2.

(First Reference Example)
Next, the pressure rise suppression means 13 in which the element holes 9 are set to 3 or more and 9 or less will be described below with reference to FIGS. 8 to 11. In this reference example, four element holes 9 are provided. In addition, about the same component as the said 1st, 2nd embodiment, the same code | symbol is attached | subjected to drawing, a structure and functional description shall be abbreviate | omitted and referred to 1st Embodiment, but the same as 1st Embodiment Since it is a structure, the effect obtained is the same.

  In the first reference example, the most suitable range of the number of element holes 9 is when four element holes 9 are provided for one element 11. When four element holes 9 are provided in one element 11 in this way, the injection pressure of the molding resin material introduced from the introduction port 3 becomes substantially equal to the injection pressure of the molding resin material flowing through the open nozzle. Moreover, the molding resin material cannot be sufficiently kneaded with the open nozzle, but the molding resin material can be sufficiently kneaded with the injection molding nozzle 1 in which the element 11 is arranged.

  The four element holes 9 are arranged at equal intervals in the circumferential direction of the element main body 23 with the outer diameter inscribed in the inner diameter of the element main body 23 at equal intervals from the center of the element main body 23. In addition, the element holes 9 and 9 provided in the adjacent elements 11 and 11 are arranged so as to be displaced by 45 ° in the rotation direction when the center of the element body 23 is the rotation axis. By arranging the element holes 9 in this manner, the kneading efficiency of the molded resin material can be improved.

  In such an injection molding nozzle 1, the pressure increase suppressing means 13 for suppressing the increase in the injection pressure of the fluid introduced from the introduction port 3 is provided in the nozzle body 7. An increase in the injection pressure of the fluid introduced from the port 3 can be suppressed, and the pressure loss of the fluid flowing through the nozzle body 7 can be reduced.

  Therefore, in such an injection molding nozzle 1, since the increase in injection pressure can be suppressed by the pressure increase suppression means 13, the increase in size of the injection molding machine can be suppressed.

  Moreover, since the pressure increase suppression means 13 is set to 3 or more and 9 or less of the element holes 9, the number of divisions of the fluid when flowing through the element 11 can be increased, and the kneading efficiency of the fluid is improved. can do. In addition, the flow path cross-sectional area of the element 11 when the fluid flows through the element 11 can be increased, and the pressure loss of the fluid flowing through the nozzle body 7 can be reduced.

  Further, the pressure rise suppression means 13 is substantially equal to the injection pressure of the fluid flowing from the inlet 3 to the outlet 5 via the plurality of elements 11 and the injection pressure of the fluid flowing directly from the inlet 3 to the outlet 5. Therefore, the pressure loss suppression means 13 can make the pressure loss substantially equivalent to that of an open nozzle in which the plurality of elements 11 are not provided in the nozzle body 7. In addition, the fluid can be kneaded in the nozzle body 7 with a pressure loss substantially equal to that of the open nozzle.

  Further, since the pressure increase suppression means 13 is set to four element holes 9, it is opened by increasing the flow sectional area of the element 11 while increasing the number of fluid divisions when flowing through the element 11. The pressure loss can be made substantially equal to that of the nozzle.

  The injection molding nozzle according to the first reference example of the present invention will be described in detail using the following examples.

(Example)
The number of element holes for one element was 3 to 9 in each example, and 2 and 10 in Comparative Examples 1 and 2. The plurality of element holes are arranged at equal intervals in the circumferential direction of the element with the outer diameter inscribed in the inner diameter of the element at equal intervals from the center of the element.

  In each example and comparative examples 1 and 2, the number of elements arranged in the nozzle body was set to six.

  Furthermore, Comparative Example 3 was an open nozzle in which no element was disposed between the inlet and the outlet and the diameter from the inlet to the outlet was constant. For this reason, the flow path cross-sectional area of the comparative example 3 is a smaller value than the other examples and comparative examples.

  In each example and each comparative example, the injection pressure (MPa) was measured when the injection speed of the injection molding machine was 20, 50, 80 (mm / sec).

  The results are shown in the table of FIG. The table in FIG. 3 also shows the flow path cross-sectional area and the number of divisions in each example and each comparative example. FIG. 4 shows the relationship between the element hole and the channel cross-sectional area.

  As is apparent from the table and FIG. 4, each of the examples according to the present invention had a lower injection pressure than the comparative example 1 having two element holes per element.

  On the other hand, in Comparative Example 2 having 10 element holes per element, the injection pressure was increased as compared with Comparative Example 1.

  Further, in Example 2 having four element holes per element, the injection pressure was substantially equivalent to the injection pressure of Comparative Example 3 which is an open nozzle.

  Further, the number of divisions 46656 (times) or more of each embodiment (minimum element hole 3, element number 6) of the present invention is about the number of divisions 4096 (times) of Comparative Example 1 (element hole 2, element number 6). The injection molding nozzle according to each embodiment of the present invention has a kneadability that is at least about 11 times that of the conventional injection molding nozzle. In addition, the channel cross-sectional area of 103.8 (mm2) or more in each example of the present invention is larger than the channel cross-sectional area of 100.5 (mm2) of Comparative Example 1.

  From this, it can be seen that by increasing the number of element holes per element, the number of divisions can be increased and kneadability can be improved.

  However, if 10 or more element holes are provided per element, the cross-sectional area of the flow path becomes small and the injection pressure increases, and the injection pressure cannot be reduced.

  Therefore, when the element holes are provided in the range of 3 to 9 per element, the kneadability is improved and the injection pressure is reduced as compared with the conventional injection molding nozzle having two element holes per element. It can be seen that an injection molding nozzle can be obtained. In addition, it can be seen that when four element holes are provided per element, an injection molding nozzle can be obtained that can be substantially equivalent to the injection pressure of the open nozzle.

  From the above results, in the case of the present invention (Example), it is possible to obtain an injection molding nozzle that can suppress an increase in the injection pressure of the fluid introduced from the introduction port. On the other hand, when the present invention is not satisfied (comparative example), an injection molding nozzle that is not very attractive is obtained.

(Second reference example)
As a reference example showing the relationship between the length of the injection molding nozzle and the pressure loss per element, the change in pressure loss due to the element length is shown in the table of FIG. Further, changes in pressure loss due to land lengths of the inlet and outlet are shown in the table of FIG.

  In the table of FIG. 12, the element diameter is the radius, and the element length at each element diameter of 10, 16, 20, 30, 40 (mm) is changed to 5, 10, 15.5, 20 (mm). The pressure loss (MPa) per element when the injection speed is 20, 50, 80 (mm / sec) is shown.

  As is apparent from this table, the pressure loss increases as the element length increases. For this reason, it turns out that resistance of a fluid is reduced and injection pressure can be reduced by shortening element length.

  In the table of FIG. 13, the total land length of the inlet and outlet is changed to 10, 15, 20, 25, 30, 35, 40, 45 (mm), and the injection speed is 20, 50, 80 (mm / The pressure loss per element (MPa) is shown.

  As is apparent from this table, the pressure loss increases as the land length increases. For this reason, it can be seen that by shortening the land length, the resistance of the fluid is reduced and the injection pressure can be reduced.

  From the above results, it is possible to reduce the resistance of the fluid flowing through the nozzle body by reducing the element length and the land length of the inlet and outlet, and the injection pressure of the fluid introduced from the inlet is reduced. An injection molding nozzle capable of suppressing the rise can be obtained.

  In the injection molding nozzle according to the second embodiment of the present invention, the element diameter is set to 2.5 times or more the diameter of the inlet, but this indicates a lower limit, and the upper limit is the element. Depends on the nozzle body to be accommodated. For this reason, the diameter of the nozzle body is set to a size that can accommodate an element in which the diameter of the element is at least 2.5 times the diameter of the inlet.

  The present invention can be used for an injection molding nozzle.

DESCRIPTION OF SYMBOLS 1,101,201 ... Injection molding nozzle 3 ... Introduction port 5 ... Outlet port 7,207 ... Nozzle body 9 ... Element hole 11, 105, 203 ... Element 13, 103, 205 ... Pressure rise suppression means

Claims (2)

A nozzle body that is formed in a cylindrical shape and is provided with an introduction port through which fluid is introduced on one end side, and a discharge port that leads out the fluid introduced on the other end side, and the introduction port and the discharge port of the nozzle body An injection molding nozzle comprising a plurality of elements that are arranged between and introduced from the introduction port into the nozzle body through a plurality of element holes and kneaded.
In the nozzle body, there is provided pressure increase suppression means for suppressing an increase in the injection pressure of the fluid introduced from the introduction port, and the pressure increase suppression means is configured such that the length of the element is equal to the diameter of the element hole. On the other hand, it is set to 0.64 times or more and 1.6 times or less ,
The pressure rise suppression means is substantially equivalent to the injection pressure of fluid flowing from the inlet to the outlet through the plurality of elements, and substantially equal to the injection pressure of fluid flowing directly from the inlet to the outlet. nozzle for injection molding, which comprises the. A nozzle body that is formed in a cylindrical shape and is provided with an introduction port through which fluid is introduced on one end side, and a discharge port that leads out the fluid introduced on the other end side, and the introduction port and the discharge port of the nozzle body An injection molding nozzle comprising a plurality of elements that are arranged between and introduced from the introduction port into the nozzle body through a plurality of element holes and kneaded.
In the nozzle body, there is provided pressure increase suppression means for suppressing an increase in the injection pressure of the fluid introduced from the introduction port, and the pressure increase suppression means is configured such that the length of the element is equal to the diameter of the element hole. On the other hand, it is set to 0.64 times or more and 1.6 times or less,
The nozzle for injection molding, wherein the pressure increase suppression means is set such that the diameter of the element is at least 2.5 times the diameter of the inlet.

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