JP6710593B2 - Extrusion mold - Google Patents

Description

The present invention relates to an extrusion molding die used for extrusion molding a long molded product.

Conventionally, as a method for continuously molding synthetic resins such as ultra high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), and polyimide, for example, ram extrusion as described in Patent Documents 1 to 3 There is molding.

In the ram extrusion molding described above, the resin melted in the heating area passes through the cooling area in the resin passage formed in the mold connected to the extruder. At that time, the molten resin is a surface solidified region (a region on the upstream side of the cooling region where only the surface of the resin is solidified), a completely solidified region (a region on the downstream side of the cooling region and a region solidified to the inside of the resin). ), it solidifies one by one and a continuous molded product is formed.

Japanese Patent Laid-Open No. 6-155555 Japanese Patent Laid-Open No. 10-193433 Japanese Patent No. 5087621

By the way, among the extrusion molded products formed as described above, it is difficult to adjust predetermined dimensions and appearance properties by post-processing such as cutting (for example, T-shaped or U-shaped cross-sectional shape). Deformed extrusion molded articles and the like). In this case, since the dimensions and appearance properties formed by molding become the dimensions and appearance properties of the product as they are, high dimensional accuracy and appearance quality are required.

As described above, in order to obtain good dimensional accuracy and appearance quality, it is important to reduce shrinkage when the resin is cooled and solidified, and in order to do so, the internal resin pressure is large in the surface solidified region. It is necessary to maintain the pressure so that

With respect to this point, for example, the resin passage of the mold is lengthened, or molding conditions (cylinder temperature, extrusion temperature, mold temperature, cooling water temperature, cooling water amount, etc.) are adjusted, and It is conceivable that the internal resin is retained in the surface solidified region by increasing the sliding resistance with the resin. However, if the resin passage of the mold is lengthened, the mold becomes large, which is not preferable in terms of cost and installation space. Further, when trying to increase the sliding resistance by adjusting the molding conditions, it is difficult to control it.

The present invention is to solve the above problems, and an object thereof is an extrusion molding die which can relatively easily form an extrusion molded article having desired dimensional accuracy and appearance properties, and is cost-effective. Another object of the present invention is to provide an extrusion molding die that is excellent in terms of installation space.

(1) In order to solve the above problems, an extrusion molding die according to an aspect of the present invention includes an upper die and a lower die, and the extruder is used with the upper die and the lower die clamped to each other. A resin passage through which the extruded molten resin passes is formed, and the elongated resin member is formed by cooling the molten resin and flowing out from the resin passage outlet formed at the downstream end of the resin passage. An extrusion molding die, wherein the upper mold and the lower mold are a heating region where the molten resin extruded by the extruder is heated, and the molten resin after passing through the heating region. And a cooling region for cooling the resin passage, the resin passage being provided at a portion of the resin passage on the resin passage outlet side so as to be movable back and forth with respect to one of the upper die and the lower die. Further, there is further provided a pressing portion that presses the elongated resin member passing through the portion on the resin passage outlet side in the direction toward a direction intersecting the traveling direction of the elongated resin member.

In this structure, the molten resin extruded by the extruder is cooled and solidified by the cooling region provided on the downstream side of the resin passage while passing through the resin passage, thereby forming a long resin member. It The long resin member thus formed is sequentially discharged from the resin passage outlet and cut into a desired length to produce an extruded product.

Further, in this configuration, the pressing portion provided in one of the upper mold and the lower mold is pressed against the elongated resin member passing through the resin passage outlet side portion of the resin passage, Frictional force can be applied to the resin member passing through the downstream side of the cooling region (the resin passage outlet side). Then, since the frictional force when the resin member passes through the resin passage becomes large, the internal resin of the resin member (the resin member whose surface is solidified and the inside is in a molten state) which passes through the upstream side of the cooling region. The pressure increases. As a result, it is possible to prevent the inner resin from significantly contracting when it is cooled and solidified.

Further, according to this configuration, since it is not necessary to lengthen the resin passage in order to increase the frictional force when the long resin member passes through the resin passage, it is possible to suppress an increase in size and cost of the mold. .. Further, according to this configuration, the frictional force when the long resin member passes through the resin passage is easily adjusted by moving the pressing part forward and backward with respect to the mold having the pressing part. be able to.

Therefore, according to this configuration, the extrusion molding die is capable of relatively easily forming an extrusion molding product having desired dimensional accuracy and appearance characteristics, and is excellent in terms of cost and installation space. We can provide the mold.

(2) Preferably, a through hole is formed in the pressing portion side die as the one die, and the pressing portion is a rod-shaped portion inserted into the through hole.

In this configuration, the pressing portion for applying the frictional force to the long resin member passing on the downstream side of the resin passage can be formed by the rod-shaped portion whose overall shape is rod-shaped. The structure of the part can be simplified.

(3) More preferably, the rod-shaped portion includes a brake pin that advances and retreats with respect to the through hole and a female screw portion formed in the through hole so that the tip portion can press the elongated resin member. A male screw portion that is screwed is formed, and a push bolt that presses the brake pin toward the elongated resin member side at the tip portion is provided.

In this configuration, the pressing force of the brake pin against the long resin member passing through the resin passage is obtained by tightening the push bolt to advance it toward the brake pin or loosening the push bolt and retracting it from the brake pin. Can be easily adjusted.

(4) Preferably, the rod-shaped portion is provided so as to be movable back and forth along a direction perpendicular to the traveling direction of the elongated resin member.

With this configuration, since the pressing force of the rod-shaped portion can be applied in the direction perpendicular to the traveling direction of the long resin member, the pressing force of the rod-shaped portion does not disperse in the traveling direction of the long resin member. The pressing force can be efficiently transmitted to the long resin member.

(5) Preferably, the portion of the pressing portion that presses the elongated resin member presses the flat portion of the elongated resin member.

For example, when the pressing portion presses a corner portion of the elongated resin member, the pressing force of the pressing portion may not be stably transmitted to the elongated resin member. On the other hand, as in this configuration, the pressing portion presses the flat portion of the elongated resin member, so that the pressing portion reliably presses the desired position on the elongated resin member. be able to. Then, the pressing force of the pressing portion with respect to the long resin member can be stabilized, and by extension, the dimensional accuracy and appearance of the long resin member can be stabilized.

(6) Preferably, the extrusion molding die is formed with a plurality of the resin passages, and the extrusion molding die is provided with a plurality of the resin passages respectively corresponding to the plurality of resin passages. It further comprises a pressing portion.

With this configuration, by individually adjusting the pressing amount of each pressing portion, it is possible to individually adjust the frictional force with respect to the long resin member that advances in each of the plurality of resin passages. As a result, the dimensional accuracy and appearance of each long resin member can be adjusted individually.

According to the present invention, there is provided an extrusion molding die capable of relatively easily forming an extrusion molding product having desired dimensional accuracy and appearance properties, which is excellent in terms of cost and installation space. Can be provided.

It is the schematic diagram which looked at the extruder, the metal mold|die for extrusion molding, and the elongate resin member shape|molded by these from the side. It is a cross-sectional perspective view of a long resin member. It is the figure which looked at the metal mold for extrusion molding from the upper part. It is the figure which looked at the metal mold for extrusion molding from the lower part. FIG. 5 is a sectional view taken along line VV of FIG. 3. FIG. 6 is a sectional view taken along line VI-VI of FIG. 3. It is sectional drawing of the metal mold|die for extrusion molding which concerns on an Example, Comprising: It is a figure shown corresponding to FIG. 9 is a table showing the length per unit time of each molded product when the pressing amount of the brake pin is changed from condition 1 to condition 4.

Below, the metal mold|die 1 for extrusion molding which concerns on embodiment of this invention is demonstrated. FIG. 1 is a schematic view of an extruder 50, an extrusion molding die 1, and an elongated resin member 55 molded by these, as viewed from the side.

In each of the drawings described below, for convenience of description, the direction indicated by the arrow described as front is referred to as the front side, the front, or the front side, and the direction indicated by the arrow described as rear is the rear side, the rear side. , Or the back side, the direction indicated by the arrow described as right is referred to as the right side, the direction indicated by the arrow described as left is referred to as the left side, and the direction indicated by the arrow described as above is the upper side or The direction indicated by the arrow described as "upper" and "lower" is referred to as "lower side" or "lower side".

In the extrusion molding die 1, pelletized resin material M extruded sequentially by the piston 51 (also called ram) of the extruder 50 is heated by the plasticizing cylinder 52 of the extruder 50 and the extrusion molding die 1. While being heated and melted by the region HZ, it passes through the resin passage 18 formed in the extrusion molding die 1. The molten resin passing through the resin passage 18 is cooled and solidified by the cooling zone CZ provided on the downstream side of the extrusion molding die 1. As a result, a continuous long resin member 55 is sequentially formed. The long resin member 55 is sequentially discharged from the resin passage outlet 19 of the resin passage 18 and then cut into a desired length to form an extruded product.

[Shape of long resin member]
FIG. 2 is a cross-sectional perspective view of the elongated resin member 55. In the extrusion molding die 1 according to the present embodiment, a long and slender resin member 55 is formed in the front-rear direction. As shown in FIG. 2, the elongated resin member 55 is a so-called profile extrusion molded product formed so that a cross section perpendicular to the longitudinal direction has a substantially T shape. The elongated resin member 55 includes a first portion 56 having a flat lower surface 56a and extending in the front-rear direction, and a second portion 57 extending in the front-rear direction at a center portion of the upper surface 56b of the first portion 56 in the left-right direction. And these are integrally formed.

[Structure of extrusion mold]
FIG. 3 is a view of the extrusion molding die 1 as viewed from above. FIG. 4 is a view of the extrusion molding die 1 as viewed from below. 5 is a sectional view taken along line VV in FIG. 3, and FIG. 6 is a sectional view taken along line VI-VI in FIG.

With reference to FIGS. 3 to 6, the extrusion molding die 1 includes a die body 2 having an upper die 3 and a lower die 4, a plurality of die clamping bolts 27, and a plurality of surface pressure adjusting bolts 28. , And a plurality of rod-shaped portions 26. Each rod-shaped portion 26 has a push bolt 29 and a brake pin 30.

[Upper mold configuration]
The upper die 3 has an upper outer die 5 and an upper middle die 6 with reference to FIGS. 5 and 6.

The upper outer die 5 is provided as an upper portion of the upper die 3. As shown in FIG. 5, the upper outer mold 5 includes an upper outer mold main body 11 formed in a block shape that is long in the front-rear direction and has a predetermined thickness in the vertical direction, and a rear side of the upper outer mold main body 11. And an extending portion 12 that extends further rearward from the portion of, and these are integrally formed. The extending portion 12 is formed in a semi-arcuate shape that bulges upward when viewed from the rear side. The extension portion 12 constitutes the extruder connecting portion 20 together with the extension portion 32 formed in the lower die 4 described later in detail in a state where the upper die 3 and the lower die 4 are clamped to each other.

On the lower side of the upper outer die body 11, a recess 11a into which the upper middle die 6 is fitted is formed. The upper middle mold 6 is fitted into the recess 11a. That is, the upper outer mold 5 and the upper middle mold 6 have a nested structure.

A plurality of screw holes for mold clamping bolts (not shown) and a plurality of screw holes for surface pressure adjusting bolts (not shown) are formed in the upper outer mold body 11. Each screw hole is formed by a screw hole penetrating through the upper outer die main body 11 in the vertical direction.

With reference to FIG. 3, 35 mold clamping bolt screw holes are formed corresponding to the positions of the mold clamping bolts 27. That is, the screw holes for mold clamping bolts are formed substantially uniformly over the entire upper outer mold body 11 (over both the heating region HZ and the cooling region CZ). A female screw to which the mold clamping bolt 27 can be screwed is formed on the inner peripheral surface of each screw hole for the mold clamping bolt.

The screw holes for the surface pressure adjusting bolt are formed corresponding to the positions on the surface pressure adjusting bolt 28 with reference to FIG. That is, the surface pressure adjusting bolt screw hole is formed in a part of the heating region HZ and the cooling region CZ of the upper outer die body 11. A female screw to which the surface pressure adjusting bolt 28 can be screwed is formed on the inner peripheral surface of each screw hole for the surface pressure adjusting bolt.

In addition, referring to FIG. 5, a plurality of (three in the present embodiment) cooling water pipes 16 are formed in the cooling region CZ of the upper outer mold body 11. Each cooling water pipe 16 is formed by a through hole that penetrates the cooling region CZ of the upper outer mold body 11 in the left-right direction. Cooling water flows through the cooling water pipe 16. Thereby, the molten resin conveyed sequentially from the heating zone HZ of the extrusion molding die 1 can be cooled and solidified.

Further, with reference to FIG. 5, in the heating region HZ of the upper outer mold main body 11, a heating mechanism 9 including, for example, a heater for a mold is provided. Thereby, the resin flowing in the heating region HZ of the extrusion molding die 1 can be melted.

The upper middle mold 6 is a nest fitted in the recess 11a formed in the upper outer mold 5, as shown in FIG. The upper middle mold 6 is composed of an upper middle mold body 21 that is formed in a block shape that is long in the front-rear direction and has a predetermined thickness in the up-down direction.

A plurality of through holes (not shown) for mold clamping bolts are formed in the upper middle mold body portion 21. The mold clamping bolt through holes are formed in correspondence with the positions of the mold clamping bolts 27 in FIG. Each mold clamping bolt through hole 23 is formed at a position overlapping with each mold clamping bolt screw hole when viewed from above when the upper middle mold 6 is fitted in the upper outer mold 5. Each of the mold clamping bolt through holes is formed in a size that allows the mold clamping bolt 27 to be inserted therethrough.

[Lower mold configuration]
The lower die 4 has a lower outer die 7 and a lower middle die 8 with reference to FIGS. 5 and 6. The lower die 4 is provided as a pressing portion side die provided with a rod-shaped portion 26 as a pressing portion which will be described later in detail.

The lower outer die 7 is provided as a lower portion of the lower die 4. Referring to FIG. 5, the lower outer die 7 includes a lower outer die body 31 formed in a block shape that is long in the front-rear direction and has a predetermined thickness in the up-down direction, and a rear side of the lower outer die body 31. And an extending portion 32 that extends further rearward from the portion of, and these are integrally formed. The extending portion 32 is formed in a semi-arcuate shape that bulges downward when viewed from the rear side. As described above, the extending portion 32 constitutes the extruder connecting portion 20 together with the extending portion 12 formed in the upper outer die 5 in the state where the upper die 3 and the lower die 4 are clamped to each other. Inside the extruder connecting portion 20, an extruder-side resin passage (not shown) through which the molten resin extruded by the extruder 50 passes is formed.

A recess 31a into which the lower middle mold 8 is fitted is formed on the upper side of the lower outer mold body 31. The lower middle mold 8 is fitted into the recess 31a. That is, the lower outer mold 7 and the lower middle mold 8 have a nested structure like the upper outer mold 5 and the upper middle mold 6.

With reference to FIG. 4, a plurality of screw holes 33 for mold clamping bolts and a plurality of screw holes 34 for push bolts are formed in the lower outer mold main body 31. Each of the screw holes 33 and 34 is formed by a screw hole that vertically penetrates the lower outer die main body 31. The push bolt screw hole 34 is not shown in FIG. 4 and is shown in FIGS. 5 and 6.

As shown in FIG. 4, the mold clamping bolt screw holes 33 are formed substantially uniformly (over both the heating region HZ and the cooling region CZ) over the entire upper outer mold body 11. The mold clamping bolt screw hole 33 is formed with a mold clamping bolt screw hole formed in the upper outer mold main body portion 11 when viewed from above and below when the upper mold 3 and the lower mold 4 are clamped together. It is formed at a position corresponding to the open position. A female screw to which the mold clamping bolt 27 can be screwed is formed on the inner peripheral surface of each screw hole for the mold clamping bolt.

Referring to FIG. 4, the push bolt screw hole 34 is a through hole formed corresponding to the position of the push bolt 29, and the push bolt 29 can be screwed into the inner peripheral surface of the through hole. The screw is formed. The push bolt screw hole 34 is formed near the resin passage outlet 19 in the cooling region CZ. In the case of the present embodiment, four push bolt screw holes 34 are formed at intervals in the left-right direction with reference to FIG.

Further, with reference to FIG. 5, a plurality of (three in the present embodiment) cooling water pipes 36 are formed in the cooling region CZ of the lower outer die main body 31. Each cooling water pipe 36 is formed by a through hole that penetrates the cooling region CZ of the lower outer die body 31 in the left-right direction. Cooling water flows through the cooling water pipe 36. Thereby, the molten resin conveyed sequentially from the heating zone HZ of the extrusion molding die 1 can be cooled and solidified.

Further, referring to FIG. 5, in the heating region HZ of the lower outer die main body portion 31, as in the case of the upper outer die main body portion 11, a heating mechanism 9 including a heater for a die is provided. .. Thereby, the resin flowing in the heating region HZ of the extrusion molding die 1 can be melted.

Referring to FIG. 5, the lower middle mold 8 is a nest fitted in the recess 31 a formed in the lower outer mold 7. The lower middle mold 8 is composed of a lower middle mold body 41 that is formed in a block shape having a long length in the front-rear direction and a predetermined thickness in the vertical direction.

A plurality of through holes (not shown) for mold clamping bolts and a plurality of through holes 44 for brake pins are formed in the lower middle mold body portion 41. Each through hole penetrates the lower middle-sized main body portion 41 in the vertical direction.

The mold clamping bolt through holes are formed in correspondence with the positions of the mold clamping bolts 27 in FIG. The through holes for the mold clamping bolts are formed with screw holes for the mold clamping bolts formed in the upper outer mold body 11 when viewed from above and below in a state where the upper mold 3 and the lower mold 4 are clamped together. It is formed at a position corresponding to the open position. The through hole for the mold clamping bolt formed in the lower middle mold body portion 41 is formed to have a size through which the mold clamping bolt 27 can be inserted, like the through hole for the mold clamp bolt formed in the upper middle mold body portion 21. ing.

The brake pin through hole 44 is formed corresponding to the position of the push bolt 29 with reference to FIG. 4. That is, the brake pin through hole 44 is formed near the resin passage outlet 19 in the cooling region CZ. In the case of this embodiment, four brake pin through holes 44 are formed at intervals in the left-right direction. Referring to FIG. 6, each brake pin through hole 44 is formed at a position where it overlaps with a corresponding push bolt screw hole 34 when viewed from above and below. Each brake pin through hole 44 is formed in a size that allows the brake pin 30 to be inserted therethrough.

[Construction of resin passage]
A resin passage 18 is formed on the PL surface of the extrusion molding die 1 (specifically, the lower surface of the upper die 3 and the upper surface of the lower die 4) with reference to FIG. The resin passage 18 includes an upstream resin passage 18a composed of groove-shaped portions formed in the upper outer die 5 and the lower outer die 7, and a groove-shaped portion formed in the upper middle die 6 and the lower middle die 8 respectively. And a downstream resin passage 18b (see FIGS. 5 and 6) formed by the upper surface of the. Since FIG. 5 is a vertical cross-sectional view of the extrusion molding die at a predetermined position, it seems that the upstream resin passage 18a does not communicate with the extruder 50 side. 18a communicates with the resin passage on the extruder 50 side.

The upstream resin passage 18a has the above-mentioned extruder-side resin passage and four branch passages (not shown) branched from the downstream end of the extruder-side resin passage.

With reference to FIG. 6, four downstream resin passages 18b are formed between the upper middle mold 6 and the lower middle mold 8 in the state where the upper mold 3 and the lower mold 4 are clamped to each other. The upstream end of each downstream resin passage 18b communicates with the downstream end of each branch passage of the upstream resin passage 18a. As a result, the molten resin extruded from the extruder 50 flows through the extruder-side resin passage and then branches into each branch passage, and the molten resin flowing through each branch passage communicates with the downstream end of each branch passage. It will flow through each downstream resin passage 18b.

The four downstream resin passages 18b are formed so as to be spaced from each other in the left-right direction and extend in the front-rear direction. Each of the downstream resin passages 18b is formed in a cross-sectional shape such that the elongated resin member 55 solidified while passing through the downstream resin passage 18b has a substantially T-shaped cross section shown in FIG. Has been done. With reference to FIG. 6, each push bolt 29 and each brake pin 30 are correspondingly arranged below each downstream resin passage 18b arranged in the left-right direction of the extrusion molding die 1.

[Structure of each bolt and brake pin]
The mold clamping bolt 27 is a bolt for clamping the extrusion molding die 1. In the extrusion molding die 1, the upper die 3 is superposed on the lower die 4, and the die clamping bolts 27 are screwed with the die clamping bolt screw holes and the die clamping bolt through holes overlapping in the vertical direction. It As a result, the extrusion molding die 1 is clamped.

The surface pressure adjusting bolt 28 is a bolt for adjusting the surface pressure of the PL surface (mold dividing surface) between the upper middle mold 6 and the lower middle mold 8 in the extrusion molding die 1. Specifically, the surface pressure adjusting bolt 28 is used for the surface pressure adjusting bolt so that the tip of the surface pressure adjusting bolt 28 presses the upper middle mold 6 in a state where the upper mold 3 is placed on the lower mold 4. It is screwed into the screw hole 14. At this time, the surface pressure of the PL surface between the upper middle mold 6 and the lower middle mold 8 can be adjusted by adjusting the degree of tightening of the surface pressure adjusting bolt 28.

The push bolt 29 is screwed into the screw hole 34 for the push bolt. Each push bolt 29 is for pushing the corresponding brake pin 30 upward by its tip portion. As shown in FIGS. 5 and 6, each of the push bolts 29 is perpendicular to the direction in which the resin passage 18 extends (that is, the traveling direction of the elongated resin member 55 passing through the resin passage 18). It is provided in.

The brake pin 30 is inserted into the brake pin through hole 44, and a portion opposite to the tip portion (lower portion in FIG. 6) is supported by the tip portion of the push bolt 29. As shown in FIGS. 5 and 6, each brake pin 30 is provided so as to be perpendicular to the traveling direction of the elongated resin member 55 passing through the resin passage 18, as in the case of the push bolt 29. Has been.

The tip of the brake pin 30 is exposed in the downstream resin passage 18b, and the tip of the brake pin 30 presses the lower surface 56a (see FIG. 2) of the elongated resin member 55 passing through the downstream resin passage 18b. You can Specifically, by adjusting the tightening amount of the push bolt 29, the pressing force of the brake pin 30 against the elongated resin member 55 can be adjusted. The reason for adjusting the pressing force applied to the elongated resin member 55 in this manner will be described in detail below along with the molding process of the elongated resin member 55.

[Molding process of long resin member]
With reference to FIGS. 1 to 6, in the extrusion molding die 1 according to the present embodiment, the upper mold 3 and the lower mold 4 are clamped by the mold clamping bolts 27, and the upper middle mold 6 and the lower mold 6 are fixed by the surface pressure adjusting bolts 28. Surface pressure adjustment with the middle mold 8, tightening amount of the push bolt 29 (that is, pressing force of the push bolt 29 against the long resin member 55 passing through the resin passage 18), other molding conditions (mold temperature, etc.) ) Is appropriately set, the resin material M is extruded by the extruder 50. The resin material M extruded by the piston 51 passes through the upstream resin passage 18a (that is, the extruder-side resin passage and the branch passage) while being heated and melted, and from the downstream end of each branch passage to each downstream resin. It flows into the passage 18b.

The molten resin flowing into each downstream resin passage 18b flows into the cooling zone CZ while being heated by the heating mechanism 9 provided in the heating zone HZ. In the upstream portion (surface solidified region) in the cooling region CZ, the molten resin is cooled by the cooling water flowing through the cooling water pipes 16 and 36, so that the surface portion of the molten resin flowing through the downstream resin passage 18b is solidified. It Then, in the downstream side portion (completely solidified region) in the cooling region CZ, the inside of the resin is solidified as well. As a result, the elongated resin member 55 in which the surface and the inside of the resin are solidified is generated. The elongated resin member 55 thus generated is sequentially discharged from the resin passage outlet 19 to the outside of the mold.

[About the function of the brake pin]
By the way, the elongate resin member 55 produced by the extrusion molding die 1 according to the present embodiment is a so-called deformed extrusion molded product, and has a complicated shape as compared with a round bar-shaped or plate-shaped extrusion molded product. Therefore, post-processing after extrusion molding is very difficult. That is, in a profile extrusion-molded product, the dimensions and appearance properties obtained by extrusion molding are the same as the product dimensions and appearance properties.

As described above, in order to obtain good dimensional accuracy and appearance quality, it is important to reduce shrinkage when the molten resin is cooled and solidified, and in order to do so, in the surface solidified region (in the resin passage 18). It is necessary to maintain the internal resin pressure so that the internal resin pressure becomes large in the upstream side portion of the cooling zone CZ).

In this regard, in the extrusion molding die 1 according to the present embodiment, by adjusting the tightening amount of the push bolt 29, the brake pin 30 is pushed against the long resin member 55 passing through the downstream resin passage 18b. The pressure can be adjusted. For example, referring to FIGS. 5 and 6, when the push bolt 29 is tightened, the pressing force of the brake pin 30 against the elongated resin member 55 passing through the portion of the downstream resin passage 18b on the resin passage outlet 19 side is reduced. growing. Then, the frictional force when the long resin member 55 passes through the surface solidification region in the downstream resin passage 18b becomes large. This makes it possible to maintain the internal resin pressure in the surface solidified region so as to increase. In this way, by adjusting the tightening amount of the push bolt 29 and adjusting the pressing force of the brake pin 30 against the elongated resin member 55, the elongated resin member 55 having desired dimensional accuracy and appearance characteristics. Can be generated.

[Example]
Next, the extrusion molding die according to the embodiment of the present invention will be described. FIG. 7 is a cross-sectional view of the extrusion molding die 1a according to the embodiment, and is a view corresponding to FIG.

The extrusion molding die 1a according to the present embodiment is different from the extrusion molding die 1 according to the above-described embodiment in the configuration of the upper middle die 6a in the die body 2a. Specifically, in the upper middle mold 6 of the above-described embodiment, the long-sided resin member 55 formed by the upper middle mold 6 has a substantially T-shaped cross-section in the downstream resin passage 18b in the cross-section. The shape of the part is substantially T-shaped. On the other hand, in the upper middle mold 6a of the present embodiment, the shape of the downstream resin passage 18c in the cross section is a horizontally long rectangular shape.

Also in the extrusion molding die 1a according to the present embodiment, four downstream resin passages 18c are formed, as in the case of the above embodiment. Also in this embodiment, as in the case of the above-described embodiment, the push bolt 29 and the brake pin 30 are provided corresponding to each downstream resin passage 18c. In the following, the length of each long resin member per unit time is adjusted by individually adjusting the pressing amount of the brake pin 30 by the push bolt 29 (that is, the pressing force of the long resin member 55 by the brake pin 30). It was verified whether or not the same level can be achieved. In addition, hereinafter, with reference to FIG. 7, each of the four downstream resin passages 18c is referred to as a passage PA, a passage PB, a passage PC, and a passage PD in order from the left side. Further, each of the molded products generated through the passages PA, PB, PC, PD is referred to as a molded product SA, SB, SC, SD.

[Evaluation method]
The molten resin was passed through each of the four passages PA to PD using an extruder having a plasticizing cylinder of about 160 degrees and a mold heating area of about 140 degrees, and was cooled and solidified by cooling water. Thereby, molded products SA to SD having a width of 12 mm and a thickness of 3 mm were simultaneously molded.

At that time, at first, the molded products SA to SD are not pressed by the brake pin 30, and the molded products SA to SD are simultaneously discharged from the four resin passage outlets, and after a certain period of time, the four molded products become the same. The location was marked, and the length from that position to the tip of the molded product was measured to confirm the variation in the molded product length per unit time. Based on the result, the pushing amount of the brake pin 30 is individually adjusted by the push bolt 29 to change the extrusion speed to determine whether or not the lengths of the molded products SA to SD per unit time are about the same. Verified. As the resin, powdery ultra high molecular weight polyethylene (UHMW-PE) was used.

[Evaluation results]
FIG. 8 is a table showing the length per unit time of each of the molded products SA to SD when the pressing amount of the brake pin 30 is changed from Condition 1 to Condition 4. In Condition 1 in FIG. 8, the brake pins 30 do not press the molded products SA to SD. Under the condition 2, only the brake pins 30 of the passages PB and PC were pressed. In Condition 3, as compared with Condition 2, the pressing amounts of the brake pins 30 in the passages PB and PC are slightly reduced and the brake pins 30 in the passages PA and PD are pressed. In Condition 4, as compared with Condition 3, the pressing amount of the brake pin 30 in the passages PB and PC is further reduced and the pressing amount of the brake pin 30 in the passages PA and PD is further increased.

In condition 1, the lengths of the molded products SB and SC were longer than the lengths of the molded products SA and SD. Therefore, in condition 2, by pressing only the brake pins 30 of the passages PB and PC, four molded products SA to Attempts were made to make all SDs the same length. As a result, referring to FIG. 8, since the extrusion speeds of the passages PB and PC are extremely reduced, the lengths of the molded products SB and SC are extremely shorter than the lengths of the molded products SA and SD. It was

Under the condition 3, in order to match the lengths of the molded products SB and SC, which have become extremely short as described above, with the lengths of the molded products SA and SD, the brake pins of the passages PB and PC are different from those of the condition 2. The pressing amount of 30 is slightly reduced and the brake pins 30 of the passages PA and PD are pressed. As a result, as shown in FIG. 8, the lengths of the molded products SB and SC became closer to the lengths of the molded products SA and SD.

In condition 4, in order to make the lengths of all the molded products SA to SD more uniform, the pressing amount of the brake pin 30 of the passages PB and PC is further reduced and the brake pin 30 of the passages PA and PD is made different from the condition 3. The pressing amount was further increased. As a result, as shown in FIG. 8, the lengths of all the molded products SA to SD could be made almost uniform.

As described above, by individually adjusting the pressing amount of the brake pin 30 provided in each of the passages PA to PD of the extrusion molding die 1a according to the present embodiment, each molded product SA to SD per unit time. It was confirmed that the lengths of can be made uniform. It is considered that the same effect can be obtained also in the extrusion molding die 1 in which the cross-sectional shape of the downstream resin passage is different.

The lengths of the molded products SA to SD can be further made uniform by further finely adjusting the pressing amount of each brake pin 30 under the above-mentioned Condition 4. Alternatively, by adjusting only the pressing amount of the brake pin 30 of the passages PB and PC under the above-mentioned condition 2, it is possible to further align the lengths of the molded products SA to SD.

[effect]
As described above, in the extrusion-molding die 1 according to the above-described embodiment, the molten resin extruded by the extruder 50 passes through the resin passage 18 and the cooling region provided on the downstream side of the resin passage 18. The long resin member 55 is formed by being cooled and solidified by the CZ. The long resin member 55 thus formed is sequentially flown out from the resin passage outlet 19 and cut into a desired length to produce an extruded product.

In addition, in the extrusion molding die 1, the pressing portion (bar shape in the case of the present embodiment) provided in one of the upper die 3 and the lower die 4 (the lower die 4 in the case of the present embodiment). By pressing the portion 26) against the elongated resin member 55 passing through the portion of the resin passage 18 on the resin passage outlet 19 side, the elongated resin member passing through the cooling region downstream side (resin passage outlet 19 side). A frictional force can be applied to 55. Then, since the frictional force when the resin member passes through the resin passage 18 becomes large, the resin member passing through the upstream side of the cooling region CZ (the resin member whose surface is solidified and the inside is in a molten state) Internal resin pressure increases. As a result, it is possible to prevent the inner resin from significantly contracting when it is cooled and solidified.

Further, according to the extrusion molding die 1, since it is not necessary to lengthen the resin passage in order to increase the frictional force when the long resin member 55 passes through the resin passage 18, it is possible to increase the size of the die and Higher costs can be suppressed. Further, according to the extrusion molding die 1, the rod-shaped portion 26 is advanced and retracted with respect to the die having the rod-shaped portion 26 (the lower die 4 in the case of the present embodiment), so that the elongated shape is obtained. The frictional force when the resin member 55 passes through the resin passage 18 can be easily adjusted.

Therefore, the extrusion molding die 1 is an extrusion molding die that can relatively easily form an extrusion molded article having desired dimensional accuracy and appearance, and is excellent in terms of cost and installation space. A molding die can be provided.

In addition, in the extrusion molding die 1, the pressing portion for applying a frictional force to the elongated resin member 55 passing on the downstream side of the resin passage 18 has a rod-shaped portion 26 having a rod-shaped overall shape. Therefore, the structure of the pressing portion can be simplified.

Further, in the extrusion molding die 1, the push bolt 29 is tightened to advance toward the brake pin 30, or the push bolt 29 is loosened and retracted from the brake pin 30 to pass through the resin passage 18. The pressing force of the brake pin 30 against the elongated resin member 55 can be easily adjusted.

Further, in the extrusion molding die 1, the rod-shaped portion 26 (the push bolt 29 and the brake pin 30) is provided so as to be perpendicular to the traveling direction of the long resin member 55 passing through the resin passage 18. ing. By doing so, the pressing force of the rod-shaped portion 26 can be applied in the direction perpendicular to the traveling direction of the elongated resin member 55, so that the pressing force of the rod-shaped portion 26 is dispersed in the traveling direction of the elongated resin member 55. Without pressing, the pressing force can be efficiently transmitted to the elongated resin member 55.

Further, in the extrusion molding die 1, since the brake pin 30 presses the flat portion (the lower surface 56a) of the long resin member 55, the desired position on the long resin member 55 is surely pressed. can do. Then, the pressing force of the brake pin 30 against the elongated resin member 55 can be stabilized, and the dimensional accuracy and appearance of the elongated resin member 55 can be stabilized.

In addition, in the extrusion molding die 1, by individually adjusting the pressing amount of each rod-shaped portion 26 (that is, the tightening amount of each push bolt 29), the length of advancing in each of the plurality of downstream resin passages 18b is increased. The frictional force on the lengthy resin member 55 can be adjusted individually. As a result, the dimensional accuracy and appearance of each long resin member 55 can be adjusted individually.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are set forth in the claims. For example, the following modified examples may be implemented.

(1) In the above-described embodiment, the rod-shaped portion 26 (the push bolt 29 and the brake pin 30) is provided on the lower die 4 side, but the invention is not limited to this and may be provided on the upper die side.

(2) In the above-described embodiment, the configuration of the pressing portion that presses the elongated resin member 55 is formed in a rod shape, but the configuration is not limited to this, and other shapes may be used.

(3) In the above-described embodiment, the rod-shaped portion 26 that presses the elongated resin member 55 is configured by the push bolt 29 and the brake pin 30, but the configuration is not limited to this, and other configurations may be used. For example, as an example, the rod-shaped portion 26 may be configured by only the push bolt 29. In this case, the long resin member 55 may be pressed by the tip of the push bolt 29.

(4) In the above-described embodiment, the rod-shaped portion 26 is provided so as to be movable back and forth along the direction perpendicular to the advancing direction of the elongated resin member 55, but the invention is not limited to this, and the elongated resin member 55 is not limited thereto. The rod-shaped portion 26 may be advanced or retracted in any direction as long as it intersects with the advancing direction.

(5) In the above-described embodiment, the flat portion of the long resin member 55 is pressed by the brake pin 30, but the present invention is not limited to this, and the friction force is applied to the long resin member 55 by the brake pin 30. Any portion may be pressed as long as it can be applied. Specifically, for example, the angular portion of the long resin member 55 may be pressed by the brake pin 30 as an example.

(6) In the above-described embodiment, an example in which the extrusion molding die 1 according to the present embodiment is applied to a profile extrusion molded product has been described, but the present invention is not limited to this, and an extrusion molded product other than the profile extrusion molded product. (For example, a round bar or a plate-shaped molded product) can be applied.

(7) In the embodiment described above, the extrusion mold having the upper mold and the lower mold having the nesting structure has been described as an example, but the present invention is not limited to this, and the present invention is formed integrally. It can also be applied to an extrusion molding die having an upper die and a lower die.

(8) In the above-described embodiment, the configuration in which the rod-shaped portions 26 provided corresponding to the resin passages 18 advance and retreat independently of each other has been described as an example, but the present invention is not limited to this, and as an example, By fixing or integrating the rod-shaped portions provided corresponding to the resin passages, the plurality of rod-shaped portions may be interlocked to advance and retreat.

INDUSTRIAL APPLICABILITY The present invention can be widely applied to extrusion molding dies used when extrusion molding a long molded product.

DESCRIPTION OF SYMBOLS 1 Extrusion mold 3 Upper mold 4 Lower mold 18 Resin passage 19 Resin passage outlet 26 Rod-shaped part (pressing part)
50 Extruder 55 Long resin member CZ cooling area HZ heating area

Claims (6)

A resin passage having an upper die and a lower die, through which the molten resin extruded by the extruder in a state where the upper die and the lower die are clamped with each other is formed, and the molten resin is cooled, the resin passage A die for extrusion molding in which a long resin member is formed by flowing out from a resin passage outlet formed at the downstream end of
The upper mold and the lower mold have a heating region that is a region in which the molten resin extruded by the extruder is heated, and a cooling region in which the molten resin is cooled after passing through the heating region. Including,
A portion of the resin passage on the resin passage outlet side is provided so as to be able to move forward and backward with respect to one of the upper die and the lower die, and passes through a portion of the resin passage on the resin passage outlet side. The elongated resin member is further provided with a pressing portion that presses in a direction intersecting the traveling direction of the elongated resin member ,
A through hole is formed in the pressing part side mold as the one mold,
The pressing portion is a rod-shaped portion that is inserted into the through hole,
The rod-shaped portion,
A brake pin that advances and retreats with respect to the through hole so that the tip portion can press the elongated resin member,
A male screw portion that is screwed into the female screw portion formed in the through hole is formed, and a push bolt that presses the brake pin at the tip portion toward the long resin member side,
Has
The brake pin has a tip end portion exposed to the resin passage, and is capable of contacting the elongated resin member passing through the resin passage to directly press the elongated resin member. And the extrusion mold. The extrusion mold according to claim 1,
The through hole is provided with a push bolt screw hole into which the push bolt is screwed, and a brake pin insertion hole that is formed in a state of communicating with the push bolt screw hole and into which the brake pin is inserted. The extrusion molding die is characterized in that the push bolt screw hole and the brake pin insertion hole are provided at positions overlapping in the vertical direction. The extrusion molding die according to claim 2,
The extrusion mold, wherein the brake pin inserted into the through hole for the brake pin has a portion opposite to the tip portion thereof supported by the tip portion of the push bolt. The extrusion mold according to any one of claims 1 to 3 ,
The extrusion-molding die is characterized in that the rod-shaped portion is provided so as to be capable of advancing and retracting along a direction perpendicular to the traveling direction of the elongated resin member. The extrusion mold according to any one of claims 1 to 4,
An extrusion molding die, wherein a portion of the pressing portion that presses the long resin member presses a flat portion of the long resin member. The extrusion mold according to any one of claims 1 to 5,
A plurality of the resin passages are formed,
The extrusion molding die, further comprising a plurality of pressing portions provided corresponding to the plurality of resin passages, respectively.

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