JP2002355861A - Method for molding resin continuous body and molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for molding a resin continuous body by which the precision of a molded product can be upgraded by equalizing the flow speed of a molten resin inside a mold during injection molding and a molding device. SOLUTION: This molding device comprises the mold 1 which forms a longitudinally long space part 3, a piston mounted, in a freely sliding manner, in the space part 3 and a supply channel 6 which guides the molten resin to be supplied from an injection molding machine 7 to the space part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for molding a long resin body.

[0002]

2. Description of the Related Art Conventionally, in order to produce, for example, a hollow elongated body by injection molding of a molten resin, a multipoint pin gate or a film gate is provided at one end of a mold having a shaft therein, and a metal gate is provided. BACKGROUND ART A molding apparatus and a molding method for supplying a thermoplastic molten resin into a mold are widely used.

[0003]

As shown in FIG. 10, the molten resin R supplied to the inside of the mold 41 depends on the flow rate of the resin inside the mold 41 due to the arrangement of the gate 44 and the balance of the molten resin supply. The inside of the mold 41 becomes uneven. At this time, at the place where the molten resin R precedes, as shown by the two-dot chain line in FIG.
The problem that the molded product is bent in the opposite direction because the bent shaft 42 tends to return when the molded product is removed from the mold 41 when the molded product is removed from the mold 41 when the shaft 42 is bent by the pressure of the molten resin R. There is a point.

Further, as molded products, there are rollers used in OA equipment such as copiers and printers. At present, these tend to be capable of high-speed processing and large-size paper, and long and high-precision ones are particularly preferred. Has been requested. In the case where the product has a long and narrow shape, the flow path of the molten resin R in the mold 41 becomes narrow, and the flow resistance of the molten resin R increases. There is a problem that the size of the shaft 42 is increased, and as a result, the deformation of the shaft 42 is promoted.

Accordingly, the present invention provides a method and apparatus for molding a long resin body, which can improve the accuracy of a molded product by making the flow rate of a molten resin in a mold uniform during injection molding. The purpose is to do.

[0006]

In order to achieve the above-mentioned object, a method for molding a long resin body according to the present invention comprises supplying molten resin from a gate to a linear space in a mold, and The space is filled while a piston previously mounted near the gate in the space is pushed by the molten resin in the axial direction of the space.

Further, a linear space portion is arranged vertically in a vertical direction, molten resin is supplied to the space portion from a gate at a lower end side of the space portion, and a piston previously mounted on a lower end side of the space portion is provided. The space is filled with the molten resin while pushing up the space vertically upward.

[0008] Further, the apparatus for molding a long resin body according to the present invention comprises a mold for forming a linear space, a molten resin which is slidably mounted in the space and supplied to the space. And a supply path for guiding the molten resin supplied from the injection molding machine to the space.

A mold for forming a linear space;
A piston slidably mounted in the space to provide flow resistance to the molten resin supplied to the space, a circumferential film gate communicating with one axial end of the space, and And a supply path having an enlarged vacant resin reservoir communicating with the film gate.

[0010] Further, a mold provided around a shaft to form an annular space portion, and a ring slidably mounted in the space portion to provide flow resistance to the molten resin supplied to the space portion. And a supply path for guiding the molten resin supplied from the injection molding machine to the space.

A mold provided around a shaft to form an annular space, and a ring mounted slidably in the space to apply flow resistance to the molten resin supplied to the space. A supply path comprising a ring-shaped piston, an annular film gate communicating with one end of the space in the axial direction, and an enlarged annular chamber-shaped resin reservoir communicating with the film gate.
It has.

Further, the shaft is hollow, and is integrated with the molten resin and taken out of a mold as a molded product. Further, the piston has resistance adding means. Further, the piston is formed by coating metal with plastic. Further, the space portion is disposed vertically in a vertical direction.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 1 shows an embodiment of an apparatus for molding a long resin body according to the present invention.
And a molten resin supply path main body 8 and a molten resin injection molding machine 7. The mold 1 has a circular hole 9 for molding a long body, and a shaft 2 is inserted in the center of the hole 9 to form an annular space (in a longitudinally elongated linear shape) inside the mold 1. A part 3 {cavity} is formed. The mold 1 and the shaft 2 are detachably fixed to a supply path main body 8 to which an injection molding machine 7 is connected. FIG. 2 shows another embodiment of the present invention, in which the annular space 3 (the mold 1) is disposed vertically in the vertical direction, and the supply path main body 8 is provided at the lower end of the space 3. Is an apparatus for molding a long resin body. Further, the annular space portion 3 may be not only an annular shape but also an annular shape having another cross-sectional shape such as an ellipse or a rectangle.

As will be described in detail later, FIG. 9 shows still another embodiment of the molding apparatus. The mold 1 of the resin elongated body molding apparatus of FIG. 9 has a solid elongated body molding hole 9 ′,
Space part 3 {cavity} which is elongated in the longitudinal direction
─ is formed. The long resin body molded by the mold 1 has a solid cylinder, prism, or other cross-sectional shape.

The molding apparatus of the present invention shown in FIG.
This is a molding apparatus for forming a roller by coating the outer periphery of a metal shaft 2 with molten resin R by injection molding, and having a protruding shaft 10 at both ends of the shaft 2. The shaft 2 is inserted into a holding hole 11 provided in the main body 8.
Holding. The molded product obtained by coating the molten resin R on the shaft 2 is sequentially taken out of the mold 1, so that the shaft 2 corresponds to a component supplied into the mold 1 one after another.

The rollers manufactured by the molding apparatus shown in FIGS. 1, 2 and 9 are used for OA equipment such as copiers and printers. The rollers to be used are particularly required to be long and highly accurate.

The molding apparatus shown in FIG. 1 and FIG.
As shown in FIG. 1, a ring-shaped piston 5 is slidably mounted in the annular space 3 in the mold 1. That is, the piston 5 is inserted into the mold 1 such that the outer peripheral surface of the piston 5 can slide on the inner peripheral surface of the mold 1 and the inner peripheral surface of the piston 5 can slide on the outer peripheral surface of the shaft 2. The ring-shaped piston 5 is arranged in advance so as to contact the vicinity of the gate 4 of the supply path main body 8 or the end of the annular space 3.

In the apparatus shown in FIG. 9, a short cylindrical piston 5 having no center hole is slidably inserted into a cylindrical space 3 in a mold 1. That is, the piston 5 is provided on the inner peripheral surface of the mold 1.
The piston 5 is inserted into the mold 1 such that the outer peripheral surface of the piston 5 can slide. The piston 5 is arranged in advance so as to contact the vicinity of the gate 4 of the supply path main body 8 or the end of the space 3.

The supply path main body 8 includes a gate 4 for injecting the molten resin R into the mold 1 and a supply path 6. Is done. In the above configuration, by the operation of the injection molding machine 7, the thermoplastic molten resin R is injected from the gate 4 through the supply path 6, filled in the space 3 in the mold 1, and solidified by cooling. A finished product roller 36 externally fitted to the shaft 2 as shown in FIG. 1 and a solid long pillar-shaped product (roller), not shown, are obtained. The cross-sectional shape of the formed roller can be elliptical or polygonal depending on the cross-sectional shape of the mold.

In the molding apparatus of the present invention, since the piston 5 is slidably mounted in the space 3, the molten resin R is injected from the gate 4 into the space 3 through the supply path 6, and When the space 3 is filled (injection molding), a piston 5 exists immediately before (near) the gate 4, and the molten resin R pushes the piston 5 while opposing the sliding resistance W of the piston 5. 4 and 9, the tip (upper end) of the molten resin R fills the space 3 at the same height (in the axial direction c of the mold 1). That is, non-uniformity of the flow velocity distribution caused by the gate shape and the flow rate difference of the molten resin R is not generated or at least reduced by the movement suppressing effect of the piston 5 which gives the molten resin R a flow resistance. . That is, the difference in the flow velocity distribution of the molten resin R in the same cross section of the space 3 can be eliminated or reduced (reduced) by the sliding resistance W of the piston 5.

As described above, by the flow velocity control function of the molten resin R by the sliding resistance W of the piston 5, the molten resin R is placed in the mold 1 at the same height in the axial direction c in the mold 1. 1 is filled in the space 3 and then cooled, so that the deformation of the shaft 36 due to the pressure difference of the molten resin R or the injection pressure causes the deformation of the roller 36 after molding, and the cooling rate due to the difference in the injection speed. Due to the difference, it is possible to significantly prevent unevenness of the outer diameter of the roller 36 after molding and deterioration of the surface roughness such as streaks and patterns on the roller surface.

Further, according to the molding method of the present invention, the shaft 2 does not curve, and the flow of the molten resin R is uniform, or at least the non-uniformity is reduced as compared with the conventional method shown in FIG. , The internal distortion hardly occurs in the shaft 2,
Also, since the residual stress is hardly generated, the finished roller 36
When the roller 36 is used for a long period of time, especially in the case of the roller 36 which is long and has a large slenderness ratio, it is possible to reduce the aging change such as the runout of the axis of the roller 36.

The flow rate control function of the piston 5 is, as shown in FIG. 2 and FIG. 9, more effective than injection molding with the die 1 arranged horizontally and horizontally as shown in FIG. The effect is greater when the mold 1 is arranged vertically in the vertical direction. This is because of the speed control function of the sliding resistance W due to the weight of the piston 5 and the equalization of the potential energy in the space 3 of the molten resin R itself. This is because it is more preferable in terms of properties.

As shown in FIGS. 1, 2 and 9,
At one end (the lower end in FIGS. 2 and 9) of the space 3 of the mold 1 in the axial direction c, an annular (circumferential) film gate 14 is provided in the radial direction of the space 3. Have been. On the other end side of the film gate 14, a resin reservoir 13 having an enlarged annular cavity cross-sectional shape is continuously provided. This resin reservoir
Reference numeral 13 denotes a space having a space in the axial direction c and the radial direction of the space portion 3, and has an annular short cylindrical shape. Also,
A plurality of sprues 12 are arranged in the resin reservoir 13 in the axial direction c of the inner space 3 of the mold 1. Further, the connection position of the sprue 12 with the resin reservoir 13 is desirably at a position apart from the film gate 14 communicating with the resin reservoir 13. The film gate 14 and the resin reservoir 13 are not limited to an annular shape, but may be a circumferential shape (a continuous shape corresponding to the cross-sectional shape of the space 3).

The molten resin supplied from the injection molding machine 7 is sent to a plurality of sprues 12, and
Flows into the resin reservoir 13 having the enlarged annular cavity cross-sectional shape. Subsequently, the molten resin R is once filled in the resin reservoir 13 and immediately flushed to the film gate 14 and flows into the space 3 in the mold 1.

When the molten resin R is ejected from the film gate 14 into the space 3 through the resin reservoir 13 and fills the space 3 in the mold 1 (at the time of injection molding), the molten resin R is once discharged. Since the resin reservoir 13 is full, the injection pressure of the molten resin R from the film gate 14 becomes uniform in the resin reservoir 13. In other words, the molten resin R injected from the film gate 14 causes the annular space 3
It can be injected with the same injection speed at all circumferential positions.

The molten resin R having the same injection speed flows out from the film gate 14 having the same opening area (same thickness) in the circumferential direction by the pressure control function of the resin reservoir 13, and its flow rate is controlled. Since the difference can be eliminated, the molten resin R has a function of uniformly filling the space 3 in the height direction of the mold 1 (axial direction c). That is, depending on the gate shape and the flow rate difference of the molten resin R,
The resulting nonuniform flow velocity distribution is not generated by the equal pressure control action of the resin reservoir 13. That is, the difference in the flow velocity distribution of the molten resin R in the same cross section of the annular space 3 can be almost eliminated.

The flow rate of the molten resin R flowing into the resin reservoir 13 from the plurality of sprues 12 is large, and the flow velocity from each sprue 12 is not uniform depending on the position of the sprue 12. Therefore, when the molten resin R is directly injected from the sprue 12 (without the resin reservoir 13) into the space 3, a difference occurs in the flow velocity distribution of the molten resin R, and the filling speed varies depending on the position in the annular space 3. Becomes However, the molten resin R flowing out from the plurality of sprues 12 once collides with the inner wall of the resin reservoir 13 and is then charged into the resin reservoir 13. Therefore, as described above, the flow velocity from each sprue 12 is
Even if it is uneven depending on the position 12, the flow rate of the molten resin R injected into the space 3 is not affected. That is, the injection speed to the space 3 has a configuration that affects only the internal pressure (injection pressure of the injection molding machine 7) in the resin reservoir 13. And the molten resin R can be uniformly filled therein. in this way,
The resin reservoir 13 has a function of suppressing the difference in the inflow speed of the molten resin R from the sprue 12 and adjusting the outflow speed to the film gate 14.

As described above, the function of controlling the flow speed of the molten resin R by the resin reservoir 13 allows the molten resin R to be further reduced as compared with the case where the molding is performed with the piston 5 alone.
It is possible to significantly prevent distortion of the roller 36 after forming, unevenness of the outer diameter of the roller 36, and deterioration of the surface roughness.

As shown in FIG. 9, a resistance adding means 26 for adjusting the moving speed of the piston 5 and controlling the flow of the resin R is provided.
May be provided on the piston 5. This actively operates the piston 5 in accordance with the injection speed (filling speed) of the molten resin R. That is, at the beginning of molding, if the flow resistance of the resin R itself is large, the piston 5 may be moved in the resin flow direction faster than the filling speed of the molten resin R (negative load), or the moving speed of the piston 5 may be reduced during molding. By making it slow, apparent sliding resistance W (positive load)
Can be controlled so as to give

To explain the resistance adding means 26 in detail, as shown in FIG. 9, for example, a connecting rod 27 is connected to the piston 5, and the connecting rod 27 has an upward moving speed of the connecting rod 27. The braking (drive) device 28 to be controlled is connected. The braking (driving) device 28 pulls up the connecting rod 27 or pushes the piston 5 (the connecting rod 2
7) It is something that brakes. The speed of the connecting rod 27 (piston 5) can be changed during the molding process.
What is necessary is just to set in advance by the control means 29 corresponding to the stroke position of (piston 5). Alternatively, the braking (driving) device 28 may be linked to the injection molding machine 7 and controlled by the operation of the injection molding machine 7 (the molten resin R injection speed).

As a simple structure of the resistance adding means 26, the mold 1 is arranged vertically in the vertical direction,
There is a method in which the sliding resistance W is secured and the flow resistance is added to the molten resin R to control the flow speed. That is, the piston 5
A connecting rod 27 is connected to the connecting rod 27, and although not shown, a resistance due to its own weight is added as a sliding resistance W by connecting a mass adding body to the tip of the connecting rod 27. Further, by connecting the piston 5 with other various sliding additional members via the connecting rod 27, resistance may be given to the movement of the piston 5 and the sliding resistance W may be added. By the resistance adding means 26 having the speed control function, the piston 5 does not suddenly move due to the injection pressure of the molten resin R, and the production efficiency can be increased.

In other words, the sliding resistance W caused by the friction between the sliding surfaces of the mold 1 and the shaft 2 and the piston 5 is difficult to control the precision of the production of the shaft and the hole. Is provided, the sliding resistance W can be adjusted.

The piston 5 is made of plastic,
Moreover, its material withstands injection temperature and injection pressure, and
It is preferable to use an engineering plastic having slidability so as not to damage the mold 1 and the shaft 2. Note that other materials such as copper which does not damage the mold 1 and the shaft 2 may be used.

As a configuration for providing an additional mechanism for giving the piston 5 a simple sliding resistance W, a metal ring 16 coated with a plastic 17 may be used as shown in FIG. By using the piston 5, the resistance due to its own weight of the piston 5 is added as the sliding resistance W. That is, by changing the material of the piston 5, its weight can be changed, and the sliding resistance W can be changed. The piston 5 may be a long cylinder or a cylinder whose one end is closed depending on the type of the mold 1 as described above, in addition to the ring.

As described above, by providing the piston 5 with the additional mechanism as described above, the sliding resistance W thereof can be easily changed. Alternatively, even when the size and length of a molded product are changed, the configuration is such that it can be easily coped with.

When the piston 5 is ring-shaped, and particularly when the diameter of the shaft 2 in the mold 1 is small, the outer peripheral surface of the shaft 2 is slid and the molten resin R Is filled and solidified, so that not only does the shaft 2 not be deformed by the injection pressure, but also the ring-shaped piston 5 has the function of forming the shaft 2 while aligning it. When the shaft 2 is held only by the supply path main body 8 with the protruding shaft 10 at the end thereof, it is somewhat unstable, but since the piston 5 supports the shaft 2, it is more accurate. High finished products can be obtained.

Thus, the molded product does not bend the shaft 2 and has no unevenness such as unevenness on the surface of the molded product.
The injection molding can be completed as shown in FIG.

Next, as shown in an enlarged sectional view of the gate 4 shown in FIG. 7, a method of taking out the molded product formed according to FIG. 2 is to use a metal having a molded product obtained by coating the shaft 2 with the resin R '. The mold 1 and the supply path main body 8 are separated. At this time, the unnecessary portion 31 remaining at the lower part of the molded product is cut by a cutting tool (not shown) at the gate 4 where the supply path 6 of the molten resin R is thinned, as shown by an arrow S in FIG. .
Thereafter, the finished product is taken out of the mold 1 together with the shaft 2 and taken out. Further, when the gate 4 is formed as a thin flat plate as shown in FIG. 7, the unnecessary portion 31 can be easily cut and removed by a cutting tool having a circular blade.

Next, the molded product has a roller outer diameter of φ12 and a length of 35.
In the case of 0 mm and a shaft 2 outer diameter of φ8, the hollow molded product according to the present invention (only the piston 5 and the piston 5 and the resin reservoir 13 are provided) and the conventional hollow molded product (the piston 5,
Table 1 shows the results of the dimensional inspection with the resin reservoir 13). In addition, as shown in FIG. 2, the molding device has a space portion 3 arranged vertically in a vertical direction. In addition, the outer diameter difference d in Table 1
Means the difference between the maximum outer shape and the minimum outer shape of the roller, and the total runout ε means the difference between the maximum position and the minimum position of the surface height in the radial direction when the roller is rotated.

[0042]

[Table 1]

As shown in Table 1, the embodiment according to the present invention is as follows.
Both the outer diameter difference d and the total runout ε can be formed with extremely high precision in the case of the first embodiment, ie, 60% as compared with the conventional product, and in the case of the second embodiment, approximately 30% as compared with the conventional product. . In addition, the condition of the surface of the molded product is also improved with respect to the streak pattern due to the cooling difference of the molten resin R. Therefore, the flow velocity control function by the piston 5 and the flow velocity control function by the resin reservoir 13 of the present invention can be achieved by a very simple configuration in improving the dimensional accuracy of the molded article of the resin long body. It can be seen that it is possible and exhibits a very effective effect.

In the above-described embodiment, the long resin body molded according to the present invention has the shaft 2 at the center and the roller 36 having the outer periphery coated with the resin R '. However, as shown in FIG. 8, the shaft 2 is made hollow (not solid), and the shaft 2 is covered with a resin R 'to form a very accurate hollow resin long body. (Composite material pipe). This makes it possible to manufacture a very long composite material pipe with extremely high strength and high precision.

Alternatively, the shaft 2 provided in the mold 1 may be used repeatedly as a part of the manufacturing apparatus (the mold 1). That is, the shaft 2 can be extracted from the molded product, and a highly accurate resin pipe can be manufactured. As another embodiment, a composite pipe in which a metal pipe is inserted into a resin pipe from which the shaft 2 is extracted may be used. Alternatively, a metal shaft having a predetermined length may be inserted. These make it possible to produce a long resin pipe and shaft having a metal core using a metal pipe and a metal shaft as a reinforcing material.

Further, as shown in FIG.
In the case of a cylindrical control cylinder (disk) without a central hole,
That is, in FIG. 1 and FIG. 2, the shaft 2 is not provided in the mold 1 and the cylindrical control cylinder (piston 5) is replaced with the mold 1.
Slidably inserted into the hole 9 ′, a high-precision solid resin shaft can be manufactured. This is because when the shape of the gate 4 for ejecting the molten resin R is a pin gate in particular, the inflow / filling / cooling speed of the molten resin R is not uniform in the same cross section of the solid shaft, and the outer diameter of the finished product is different. Although there is a possibility that a stripe pattern may be formed, the use of the control disk makes it possible to keep the flow velocity distribution uniform, and to prevent such defects and defects.

[0047]

According to the present invention, the following effects can be obtained by the above configuration.

According to the first aspect, the flow velocity distribution of the molten resin R supplied into the mold 1 in the space 3 is determined by the
Can be made uniform at all positions in the cross section. In addition, due to the flow speed control function of the piston 5, a long resin body to be molded is long, and
Even in the case of a thin shape, it is possible to improve the dimensional accuracy of the molded product by a simple method and obtain a molded product having a predetermined cross section.

According to the second aspect, the potential energy due to the weight of the piston 5 can be added to the sliding resistance W, and the flow velocity distribution of the molten resin R supplied into the mold 1 in the space 3 can be obtained. At the position in each cross section of the mold 1 can be made more uniform. Also,
The flow rate control function of the piston 5 is further enhanced,
Even when the long resin body to be molded is long and thin, the dimensional accuracy of the molded article can be significantly improved by a simple method, and a molded article having a predetermined cross section can be obtained.

According to the third aspect, the flow velocity distribution of the molten resin R supplied to the inside of the mold 1 in the space 3 is determined by the
Can be uniformly approached at the position in each cross section. Further, the piston 5 having the function of controlling the flow speed of the molten resin R enables a highly accurate molded product having a predetermined cross section to be obtained even when the molded resin long body is long and thin.

According to the fourth aspect, the flow velocity distribution of the molten resin R supplied into the mold 1 in the space 3 is determined by the
Can be made more uniform at the position in each cross section. In addition, the long body to be molded is long and has a high-precision predetermined cross section even when it is long and thin due to the piston 5 having a flow rate control function of the molten resin R and the resin reservoir 13 having a pressure control function. It is possible to obtain molded articles.

(According to claim 5) The flow velocity distribution of the molten resin R supplied into the mold 1 in the annular space 3 is represented by
The position in each cross section of the mold 1 can be approached uniformly. In addition, the piston 5 having the function of controlling the flow speed of the molten resin R can improve the dimensional accuracy of the molded article with a simple configuration even when the long body to be molded is long and has a thin shape, thereby achieving high precision. It is possible to obtain hollow (predetermined cross-section) moldings. Further, the hole of the ring-shaped piston 5 produces a centering action of the shaft 2, and it is possible to obtain a more accurate molded product.

According to claim 6, the flow velocity distribution of the molten resin R supplied into the mold 1 in the annular space 3 is represented by
The position in each cross section of the mold 1 can be made more uniform. In addition, the piston 5 having the function of controlling the flow rate of the molten resin R and the resin reservoir 13 having the pressure control function can simplify the dimensional accuracy of the molded product even when the elongated body to be molded is long and thin. Significantly improved with a simple structure, high-precision hollow (predetermined cross section)
It is possible to obtain molded articles. Further, the hole of the ring-shaped piston 5 produces a centering action of the shaft 2, and it is possible to obtain a more accurate molded product.

(According to claim 7) very high strength and
A highly accurate long composite material pipe can be manufactured with a simple configuration.

According to claim 8, the piston 5 is prevented from projecting due to the injection pressure of the molten resin R, and the sliding resistance W of the piston 5 can be easily changed. Can be increased, and even when the injection pressure and filling speed of the molten resin R at the time of injection molding, and the size and length of the molded product are changed, it is possible to easily cope with the change.

According to the ninth aspect, the sliding resistance W of the piston 5 can be increased and changed with a simple configuration, and the piston 5 is prevented from projecting due to the injection pressure of the molten resin R, and the injection resistance is reduced. It is possible to easily make the mold 1 and the shaft 2 slidable enough to withstand the temperature and the injection pressure and not to damage the mold 1 and the shaft 2.

According to the tenth aspect, the potential energy due to the weight of the piston 5 can be added to the sliding resistance W, and the flow velocity distribution of the molten resin R supplied into the mold 1 in the space 3 is obtained. Can be made uniform at the position in each cross section of the mold 1.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of a molding apparatus according to the present invention.

FIG. 2 is a side sectional view showing another embodiment of the molding apparatus of the present invention.

FIG. 3 is a cross-sectional view in FIGS. 1 and 2;

FIG. 4 is a side sectional view of a molding apparatus showing a state in the middle of molding.

FIG. 5 is a side sectional view of the molding apparatus showing a molding completed state.

FIG. 6 is a partial cross-sectional perspective view showing components.

FIG. 7 is an enlarged sectional view of a main part showing components.

FIG. 8 is a side sectional view showing another embodiment of the molding apparatus of the present invention.

FIG. 9 is a side sectional view showing still another embodiment of the molding apparatus of the present invention.

FIG. 10 is a side sectional view of a molding apparatus showing a molding state in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die 2 Shaft 3 Space part 4 Gate 5 Piston 6 Supply path 7 Injection molding machine 13 Resin reservoir 14 Film gate 26 Resistance adding means c Axis direction R Melted resin

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Ohori 663 Minoshima, Arita-shi, Wakayama Prefecture F-term (reference) 4F202 AD03 AD18 AH04 CA11 CB01 CB12 CK06 CK15 CK42 CK52 4F206 AD03 AD18 AH04 JA07 JB12 JN14 JN25 JQ81

Claims (10)

[Claims] 1. A molten resin (R) is supplied from a gate (4) to a linear space (3) in a mold (1), and a piston (5) previously mounted near the gate (4) in the space (3) is removed by the molten resin (R). A method for molding a long resin body, wherein the space is filled while being pressed in the axial direction c of the space. 2. A linear space portion 3 is disposed vertically in a vertical direction, and molten resin R is supplied to the space portion 3 from a gate 4 at a lower end side of the space portion 3, and a lower end in the space portion 3 is provided. A method for molding a long resin body, wherein the space 3 is filled while the piston 5 previously mounted on the side is pushed up vertically inside the space 3 by the molten resin R. 3. A mold 1 forming a linear space 3;
A piston 5 that is slidably mounted in the space 3 to provide flow resistance to the molten resin R supplied to the space 3
And a supply path 6 for guiding the molten resin R supplied from the injection molding machine 7 to the space 3. 4. A mold 1 forming a linear space 3;
A piston 5 that is slidably mounted in the space 3 to provide flow resistance to the molten resin R supplied to the space 3
And a supply path 6 having a peripheral film gate 14 communicating with one end of the space portion 3 in the axial direction c and an enlarged empty resin reservoir 13 communicating with the film gate 14. An apparatus for molding a long resin body. 5. A mold 1 provided around a shaft 2 to form an annular space 3, and a molten resin R which is slidably mounted in the space 3 and supplied to the space 3. A ring-shaped piston 5 for giving resistance, a supply path 6 for guiding the molten resin R supplied from the injection molding machine 7 to the space 3,
An apparatus for molding a long resin body, comprising: 6. A mold 1 provided around a shaft 2 to form an annular space 3 and a molten resin R which is slidably mounted in the space 3 and supplied to the space 3. A ring-shaped piston 5 for providing resistance, an annular film gate 14 communicating with one end of the space 3 in the axial direction c, and an enlarged annular vacant resin reservoir 13 communicating with the film gate 14
And a supply path 6 comprising: a resin long body molding apparatus. 7. The apparatus for molding a long resin body according to claim 5, wherein the shaft 2 is hollow, and is integrated with the molten resin R and taken out of the mold 1 as a molded product. 8. The apparatus for molding a long resin body according to claim 3, wherein said piston 5 has resistance adding means 26. 9. The apparatus for molding a long resin body according to claim 3, wherein the piston 5 is formed by coating a metal with a plastic. 10. The resin elongated body molding apparatus according to claim 3, wherein the space portion 3 is disposed vertically in a vertical direction.