JP3247352B2 - Pre-plastic injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a resin melted in a heating cylinder for plasticization into a heating cylinder for filling and measuring the resin by a filling plunger inserted into the heating cylinder for filling. The present invention relates to a pre-plastic injection molding machine in which a molten resin is injected into a cavity of a mold, and more particularly, to a pre-plastic injection molding machine in which a resin discharge port for discharging resin adhering to the filling plunger to the outside is provided in the filling heating cylinder. The present invention relates to an injection molding machine.

[0002]

2. Description of the Related Art Conventionally, as a pre-plastic injection molding machine, resin which adheres to a filling plunger and leaks from the fitting gap between a cylinder hole of a filling heating cylinder and a filling plunger to the rear of a head portion of the filling plunger to the outside. At a position away from the position of the head portion at the retreating end of the filling plunger, a resin discharge port to be discharged is opened downward from the cylinder hole to a filling heating cylinder or a scraper ring connected to the rear portion thereof. In order to scrape the resin adhering around the filling plunger behind the resin discharge port and drop it from the resin discharge port, a scraping sleeve is provided by being inserted into the cylinder hole, or an annular protrusion is provided on the scraper ring. What is provided is known (JP-A-9-857).
87, JP-A-8-156049). Also,
A band heater is wrapped around the outer peripheral surface of the filling heating cylinder behind the resin discharge port to heat the filling heating cylinder to a high temperature, thereby preventing solidification of the resin and preventing the operation failure of the filling plunger from occurring. (Japanese Patent Laid-Open No. Hei 8-
229997).

[0003]

However, in any of the former, the resin outlet is only one place below the heating tube for filling, and the resin may be clogged in a place other than the resin outlet. The filled resin may cause the cylinder hole of the filling plunger or the filling heating cylinder to be eccentric, and may cause biting therebetween. And in what provided the sleeve for scraping in the cylinder hole of the heating cylinder for filling,
Since the scraping sleeve is inserted into the inner side of the cylinder hole, it is difficult to manufacture.When the scraping sleeve and the filling heating cylinder are assembled, misalignment is likely to occur with each other. However, since the gap between the outer circumferential surface of the scraping sleeve and the inner circumferential surface of the cylinder hole is not constant in the circumferential direction, if the gap is clogged with resin, the misalignment of the filling plunger with respect to the filling cylinder is further increased, and There is a possibility that the degree of occurrence of the increase will increase. In the latter case, there is a problem that the resin raked in the resin discharge port hardens in a molten state and does not drop.

Accordingly, the present invention provides a method for discharging resin adhering to the periphery of a charging plunger from the resin discharging port of the filling heating cylinder without clogging the resin discharging port. An object of the present invention is to provide a pre-plastic injection molding machine in which no biting occurs with a filling plunger. Another object of the present invention is that there is no need to insert a sleeve for scraping resin into the cylinder hole of the heating cylinder for filling, and there is no occurrence of misalignment of the filling plunger with respect to the cylinder hole at the time of assembly, and production is also possible. An object of the present invention is to provide an easy pre-plastic injection molding machine.

[0005]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 comprises a plasticizing heating cylinder for plasticizing a resin material, and a resin melted in the plasticizing heating cylinder. A filling heating cylinder for measuring a resin reservoir of a cylinder hole, and a filling plunger having a head portion inserted into the cylinder hole of the filling heating cylinder so as to be able to move forward and backward, and injecting the measured molten resin into a mold cavity. And a resin discharge port for discharging resin adhering around the filling plunger is provided at a position behind the head at the retreating end position of the filling plunger. In the injection molding machine, the resin discharge port intersects a vertical discharge port penetrating vertically through the entire length of the diameter of the heating tube for filling and communicating the cylinder hole to the outside, and the vertical discharge port. Directed countercurrent to have a structure consisting of a lateral discharge port in communication with the cylinder bore to the outside.

In the invention having the above structure, the resin melted in the plasticizing heating cylinder is sent into the filling heating cylinder and is measured in the resin reservoir in front of the filling plunger which moves backward by the resin pressure. Thereafter, it is injected into the mold cavity by the advancing filling plunger. As described above, the molten resin leaking backward from the fitting gap between the cylinder hole of the heating cylinder for filling and the filling plunger while the filling plunger moves forward and backward and the weighing and injection operations are repeatedly performed is the filling plunger. The resin adheres to the outer periphery of the shaft portion behind the head portion, reaches the resin discharge port, and is discharged to the outside from both the vertical discharge port and the horizontal discharge port of the resin discharge port.

[0007] According to the apparatus having the above-mentioned structure, it is not necessary to attach a special member to the heating tube for filling. The resin can be discharged, and the molten resin does not clog the cylinder hole of the filling heating cylinder near the resin discharge port. Therefore, the misalignment between the cylinder hole and the filling plunger due to the resin, that is, the occurrence of biting between them does not occur. further,
The state of adhesion of the resin to the filling plunger can be easily confirmed from the resin outlet.

In the apparatus having the above-described structure, the resin discharge port may be formed symmetrically with respect to a plane along a vertical direction passing through a center of a cylinder hole of the filling heating cylinder. ). According to this configuration, the filling heating cylinder does not become thermally asymmetric, and the filling heating cylinder bends due to thermal deformation, and the cylinder hole and the filling plunger move when the filling plunger moves forward and backward. Accidents such as the occurrence of a bite in between are prevented.

In the apparatus having the above-mentioned structure, at least one of a vertical discharge port and a horizontal discharge port of the resin discharge port is provided with an inner peripheral portion in the axial direction of the filling plunger.
At least one of the rear surfaces may be provided with a projection directed in the axial direction. According to this configuration, when the filling plunger moves forward and backward,
The resin adhering to the outer periphery of the filling plunger is broken by the protrusion on the inner peripheral portion of the resin outlet, and easily peels off from the filling plunger and falls from the resin outlet.

Further, in the apparatus having the above structure, the resin discharge port may be provided such that an inner peripheral front surface thereof is provided forward of a rear end position of a head portion at a rear end position of the filling plunger ( (Claim 4) The vertical discharge port may be formed to have a diameter larger than the diameter of the cylinder hole (Claim 5). According to these configurations, when the filling plunger moves forward and backward, the adhered resin at the rear end side of the cylinder hole of the filling heating cylinder is scraped out to the resin discharge port by the head portion of the filling plunger projecting into the resin discharge port. At the same time, the resin adhering to the rear side of the head portion of the filling plunger is easily scraped off by the periphery of the resin discharge port. The scraped or scraped resin is easily dropped from the large-diameter resin outlet.

Further, in the apparatus having the above-described structure, the filling heating cylinder may be provided with a cooling device for cooling the filling heating cylinder behind the resin discharge port. 6). According to this configuration, the filling heating cylinder behind the resin discharge port is cooled by the cooling device, and the temperature of the filling plunger is maintained at a constant temperature at which the resin does not melt, thereby further removing the resin from the filling plunger. It can be done easily.

In the apparatus having the above structure, the diameter of the shaft hole through which the filling plunger of the filling heating cylinder is inserted is smaller than the diameter of the cylinder hole in which the head of the filling plunger of the filling heating cylinder slides. It is possible to adopt a configuration that is formed to be larger by 0.5 to 0.5 mm (claim 7). According to this configuration, the resin portion is favorably scraped from the cylinder hole of the filling heating cylinder to the resin outlet by the head portion of the filling plunger, and the resin is scraped from the head portion of the filling plunger by the inner peripheral edge of the resin outlet. Can be done.

In the apparatus having the above-mentioned structure, the filling plunger may have a structure in which a shaft portion behind the head portion is subjected to a resin adhesion preventing process. According to this configuration, the resin does not adhere to the filling plunger, so that the resin can be peeled off at the resin outlet very smoothly, and the peeled resin is easily dropped from the resin outlet.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows a screw prepra type injection molding machine 1. This screw prepra injection molding machine 1
On one side (right side in the figure) of the base 2 is a plasticizing measuring mechanism 3
An injection device 5 including an injection mechanism 4 is provided.
The plasticizing measuring mechanism 3 has a base end side fixed on a base 6 of the injection device 5 and a plasticizing heating cylinder 7 inclined so that a distal end side is downward, and an inside of the plasticizing heating cylinder 7. Screw 8, which is rotatably inserted in the plasticizing screw, a hydraulic motor 9 for rotating the plasticizing screw 8, and the plasticizing heating cylinder 7.
And a hopper 10 for supplying a resin material to the material receiving port 7a.

The injection mechanism 4 is provided with a gantry 6 of the injection device 5.
A horizontal filling heating cylinder 11 having a base end fixed to the front surface and a nozzle 12 provided at the tip, and a filling inserted in a cylinder hole 11b of the filling heating cylinder 11 so as to be able to move back and forth in the axial direction. A plunger 13 and a filling cylinder 15 fixed to the rear surface of the gantry 6 of the injection device 5 and having a ram 14 inside and connected to the rear end of the filling plunger 13 for moving the filling plunger 13 forward and backward. Have. The tip of the plasticizing heating cylinder 7 is connected to the distal end of the heating cylinder for filling 11, and the resin reservoir 11 a inside the distal end of the heating cylinder for filling 11 is connected to the distal end of the heating cylinder 7 for plasticizing. The inside and the resin supply path 7b communicate with each other. At the base end side of the filling heating cylinder 11, a resin discharge port 16 for discharging resin leaking backward from the fitting gap between the cylinder hole 11b of the filling heating cylinder 11 and the filling plunger 13 is provided.

In the figure, reference numeral 17 denotes a fixing plate of a mold clamping device for clamping a mold, and the injection device 5 is controlled by a nozzle touch cylinder 18 provided between the fixing plate 17 and the gantry 6. The nozzle 12 of the heating tube for filling 11 is moved forward and backward with respect to the fixed platen 17 to abut against the clamped mold,
It is designed to be separated. Reference numeral 19 denotes a hydraulic electric control unit, which is connected to the hydraulic motor 9, the filling cylinder 15, the nozzle touch cylinder 18, and the like, and a hydraulic sensor 20 provided on the filling cylinder 15 and various other parts provided on other operation units. The injection device 5 is operated in response to a signal from the sensor or the control device.

Next, the main part of the injection mechanism 4 is shown in FIG.
This will be described in detail with reference to FIG. The filling heating cylinder 11 is provided with a shaft hole 21 on the center line thereof. The front half of the shaft hole 21 is formed as a sleeve hole 21a larger in diameter than the shaft hole 21 and a nozzle mounting hole 21b in front of the sleeve hole 21a and larger than that. The cylinder sleeve 22 having the cylinder hole 11b and the base end of the nozzle 12 are fitted respectively. A passage 21c is formed in the tip of the heating cylinder 11 for filling and the cylinder sleeve 22 so as to penetrate them in the radial direction and communicate with the cylinder hole 11b of the cylinder sleeve 22. The passage 21c constitutes a part of a resin supply passage 7b that communicates the resin reservoir 11a formed in the front of the cylinder hole 11b with the plasticizing heating cylinder 7.

The resin discharge port 16 is provided in front of the latter half of the filling heating cylinder 11 so as to penetrate the filling heating cylinder 11 across the shaft hole 21. The resin discharge port 16 is formed so that the width of the filling heating cylinder 11 in the diameter direction is
1 and has a rectangular cross section that is longer in the axial direction of the heating tube 11 for filling and has a vertical discharge port 16a that is opened in a vertical direction (vertical direction) passing through the center of the heating tube 11 for filling.
The diameter is substantially the same as the diameter of the shaft hole 21, or the diameter of the shaft hole 21 is larger than that of the shaft hole 21. And a lateral discharge port 16b opened toward the cylinder hole 11b through the shaft hole 21. Inside the vertical discharge port 16a, front and rear surfaces 16d, 16e in the axial direction of the heating tube 11 for filling are provided.
Are provided with acute-angled projections 16c protruding in the axial direction of the heating tube 11 for filling. The projections 16c are generally provided on both the upper part and the lower part of the shaft hole 21 of the filling heating cylinder 11, but any one of them may be provided.

The filling heating cylinder 11 behind the resin discharge port 16 is provided with cooling water holes 23 which penetrate the filling heating cylinder 11 horizontally above and below the shaft hole 21. Although not shown, the cooling water hole 23 is connected by a pipe to a cooling water supply source whose temperature and supply flow rate are controlled by a control device. Further, a band heater 23 is attached to an outer periphery of the filling heating cylinder 11 in front of the resin discharge port 16.

The filling plunger 13 is inserted through the shaft hole 21 from the rear side, and the head portion 13a of the filling plunger 13 is slidably fitted in the cylinder hole 11b of the cylinder sleeve 22. 13 is movable forward and backward in the axial direction. If the fitting gap due to the diameter difference between the cylinder hole 11b and the head 13a of the filling plunger 13 is too small, the filling plunger 13
If the movement of the resin is hindered, escape of gas generated in the plasticizing step or escape of the resin staying at the tip of the filling plunger 13 becomes worse, discoloration or burning occurs in the molded product. Since resin leakage to the rear of the filling plunger 13 increases and molding becomes unstable, it is appropriately determined in consideration of the resin material and molding conditions. Usually, the diameter d1 of the head 13a of the filling plunger 13 is smaller by 0.01 to 0.2 mm than the diameter D1 of the cylinder hole 11b, and the diameter d2 of the shaft 13b behind the head 13a is the diameter d2 of the cylinder hole 11b. It is formed 0.1 to 1 mm smaller than the diameter D1.

When the charging plunger 13 moves backward and reaches the rearward end, the rear end of the head portion 13a is inserted into the cylinder hole 11b of the cylinder sleeve 22.
And the relative position between the filling plunger 13 and the resin discharge port 16 is set such that the inner peripheral front surface 16d of the resin discharge port 16 is located forward of the rear end 13c of the head portion 13a. Have been. The diameter D2 of the shaft hole 21 is equal to the diameter D1 of the cylinder hole 11b.
However, even if the diameter difference is too large or too small, the resin adhering to them from the cylinder hole 11b or the head portion 13a of the filling plunger 13 is formed. Cannot be expected to have a scraping effect on the rear of the vehicle. The diameter D2 is the resin outlet 16
The size of the front part may be different from that of the rear part.

The surface of the cylinder hole 11b of the cylinder sleeve 22 and the outer peripheral surface of the head portion 13a of the filling plunger 13 are subjected to a surface treatment for increasing hardness. Can be subjected to a conventionally known surface treatment to which chromium plating or other resin hardly adheres. The chrome plating can prevent a bite from occurring between the surface of the cylinder hole 11b and the shaft portion 13b of the filling plunger 13.

Next, the operation of the apparatus configured as described above will be described. When the mold is clamped by the mold clamping device, the nozzle touch cylinder 18 is operated by the operation of the hydraulic electric control means 19, and the injection device 5 advances to move the nozzle 12 of the heating cylinder 11 for filling to the mold. At the same time, the hydraulic motor 9 is driven to rotate the plasticizing screw 8, and the resin material supplied from the hopper 10 through the material receiving port 7 a is melt-kneaded inside the plasticizing heating cylinder 7. The molten resin is supplied from the tip of the plasticizing heating cylinder 7 to the resin supply path 7b.
The resin plunger 13, which is introduced into the resin reservoir 11 a of the filling heating cylinder 11 via the filling cylinder 15 and back-pressed by the filling cylinder 15, is retracted while the resin plunger 13 is retracted.
a (weighing step). When a predetermined amount of the molten resin is measured in the resin reservoir 11a, the hydraulic electric control means 19
The pressure oil is supplied to the filling plunger 13 by the operation described above, and the filling ram 14 is advanced. Thereby, the filling plunger 13 moves forward, and the molten resin measured in the resin reservoir 11a is injected into the mold via the nozzle 12 (injection step).

While the operations in the above steps are being performed, cooling water is supplied from the cooling water supply source to the cooling water holes 23, and the vicinity of the resin discharge port 16 of the charging heating cylinder 11 and the charging plunger 13 The shaft portions 13b are cooled, and their temperatures are maintained so that the resin does not melt. The control of the filling pressure and the holding pressure in the injection step and the back pressure in the measuring step are performed by the hydraulic electric control means 19 controlling the operating oil pressure to the filling cylinder 15 while monitoring the signal from the oil pressure sensor 20. Will be

In the step of measuring or injecting the molten resin, a resin pressure acts on the filling plunger 13, and a head portion 13 a of the filling plunger 13 receiving the resin pressure and a cylinder hole 11 b of the cylinder sleeve 22. As described above, since there is a fitting gap due to the difference in diameter between them, a part of the molten resin leaks from the fitting gap to the rear of the head portion 13a of the filling plunger 13 and the filling plunger The solidification is started by attaching to the front side of the shaft portion 13b of the thirteen. The adhered resin gradually adheres to the rear side of the shaft portion 13b, and comes into contact with the edge of the inner rear surface 16e of the resin discharge port 16 when the filling plunger 13 moves backward, so that the filling plunger 13 moves forward. Resin outlet 1 when moving
6 comes into contact with the edge of the inner front surface 16d and is peeled off.

At this time, as described above, the filling heating cylinder 11
The cooling water supplied to the cooling water hole 23 cools the periphery of the resin discharge opening 16 and the shaft portion 13b of the filling plunger 13, so that the adhered resin on the shaft portion 13b is released from the adhesive state and is appropriately cured. In this state, peeling from the shaft portion 13b is easily performed. The release resin does not adhere to the resin discharge port 16, and most of the release resin does not adhere to the vertical discharge port 16.
a to the outside and a part of the side discharge port 16b
Is discharged to The lateral discharge port 16b is used not only for discharging the adhered resin but also for the shaft portion 13b of the plunger 13 for filling the resin.
It also helps to prevent accidents in advance by observing the state of adhesion to the surroundings.

Since the resin outlet 16 is provided with sharp projections 16c on the inner front and rear surfaces 16d and 16e, the resin adhering to the shaft portion 13b is moved forward by the filling plunger 13. When the filling plunger 13 moves backward, the projection 16c on the inside rear surface 16e of the resin discharge port 16 causes the filling plunger 1 to move.
3 is cracked in the axial direction,
Easily peeled off. If the shaft portion 13b is subjected to a surface treatment that makes it difficult for the resin to adhere, the separation becomes easier, and the separated resin is smoothly discharged to the outside of the resin discharge port 16.

Since the diameter D2 of the shaft hole 21 of the filling heating cylinder 11 is set to an appropriate value larger than the diameter D1 of the cylinder hole 11b, the filling plunger 13 moves forward and backward when the filling plunger 13 moves forward and backward. 13 head part 13a
The scraping of the resin from the cylinder hole 11b to the shaft hole 21 side by the trailing edge and the scraping of the adhered resin of the head portion 13a by the boundary between the cylinder hole 11b and the shaft hole 21 are effectively performed. The scraped resin adheres to the filling plunger 13 and is peeled off as described above.

In the above embodiment, one horizontal discharge port 16b of the resin discharge port 16 penetrates the entire length of the diameter of the filling heating cylinder 11 in a horizontal direction perpendicular to the vertical discharge port 16a. However, instead of this, as shown in FIG.
1 may be provided so as to penetrate the entire length of the diameter of the heating tube 11 for filling in a direction obliquely intersecting the vertical discharge port 16a through the center of the cylinder. With such a configuration, it is possible to better observe the state of adhesion of the resin to the shaft portion 13b of the filling plunger 13 and discharge the release resin from the lateral discharge ports 16f around the heating tube 11 for charging.

In each of the above embodiments, the resin discharge port 16 is formed symmetrically with respect to the center line of the vertical discharge port 16a in the cross section of the heating cylinder 11 for filling. The heating cylinder 11 is thermally symmetrical, so that thermal distortion of itself and the cylinder sleeve 22 is suppressed, and it is possible to prevent the occurrence of biting between the cylinder hole 11b of the cylinder sleeve 22 and the filling plunger 13. However, the horizontal discharge ports 16b and 16f do not necessarily penetrate the entire length of the diameter of the heating tube 11 for filling. 11
May have a length corresponding to the radius of the filling heating cylinder 11 penetrating through the shaft hole 21 from the outer periphery of the heating hole.
It may be formed at a position off the vertical line passing through the center.

Further, in the above-described embodiment, the vertical discharge ports 16a of the resin discharge ports 16 are provided with the front and rear surfaces 16 of the inner circumference thereof.
Since projections 16c are provided on both d and 16e,
It is preferable that the resin adhering to the shaft portion 13a of the filling plunger 13 can be peeled very well.
May be omitted. In addition, the horizontal discharge port 16
A protrusion 16c may be provided on one or both of the front and rear surfaces of b and 16f. By doing so, the filling plunger 13
The resin adhering to the shaft portion 13a has a large number of cracks, and the separation is further facilitated. The cross-sectional shapes of the vertical discharge port 16a and the horizontal discharge ports 16b and 16f of the resin discharge port 16 are not limited to those of the above-described embodiment, and are arbitrary.

In the above-described embodiment, the cylinder hole 21a is formed in the cylinder sleeve 22 inserted into the sleeve hole 21a of the heating cylinder 11 for filling.
1a may be formed directly on the filling heating cylinder 11 by making the front of the shaft hole 21 smaller than that. Further, in the above-described embodiment, the present invention is applied to the screw prepra-type injection molding machine in which the plasticizing screw 8 is rotatably provided in the filling heating cylinder 11, but the present invention is not limited to this. It goes without saying that the present invention can be applied to other types of pre-plastic injection molding machines.

[0033]

As described above, according to the first aspect of the present invention, the resin discharge port of the heating tube for filling penetrates vertically over the entire length of the diameter of the heating tube for filling, and the resin discharge port extends vertically. Since the vertical discharge port that communicates with the outside of the cylinder hole of the heating cylinder and the horizontal discharge port that is oriented in a direction intersecting the vertical discharge port and communicates with the outside of the cylinder hole, the configuration is made up of these. The resin adhering to the shaft of the filling plunger can be smoothly discharged from the plurality of resin discharge ports. In addition, the side discharge port not only serves to discharge the resin,
Since the state of adhesion of the resin to the shaft portion of the filling plunger can be observed from the outside, it is possible for the operator to see the state of adhesion and to help prevent an accident or the like beforehand.

According to the second aspect of the present invention, the resin discharge port is formed symmetrically with respect to a plane along the vertical direction passing through the center of the cylinder hole of the heating cylinder for filling. The heating cylinder is thermally symmetric, the bending of the cylinder hole of the filling heating cylinder due to thermal deformation is suppressed, and the occurrence of biting between the cylinder hole and the filling plunger can be prevented.

According to the third aspect of the present invention, at least one of a vertical discharge port and a horizontal discharge port of the resin discharge port has an inner peripheral portion which is located in front of the filling plunger in the axial direction.
Since at least one of the rear surfaces is provided with a projection directed in the axial direction, the resin adhered to the outer periphery of the filling plunger by the projection on the inner peripheral portion of the resin discharge port when the filling plunger moves forward and backward. Is cracked and cracked, and is easily separated from the filling plunger, so that the release resin can be reliably discharged from the resin discharge port.

According to the fourth and fifth aspects of the present invention, the resin discharge port has an inner peripheral front surface located forward of a rear end surface position of the head of the filling plunger at a rearward end position of the filling plunger. Since the vertical discharge port is formed to have a diameter larger than the diameter of the cylinder hole, the resin adhering at the rear end side of the cylinder hole of the filling heating cylinder is projected into the resin discharge port. The resin plunger is scraped out to the resin outlet by the head of the filling plunger, and the resin adhering to the shaft of the filling plunger can be easily scraped off by the periphery of the resin outlet, and the scraped or scraped resin has a large diameter. From the resin outlet.

According to the sixth aspect of the present invention, since the cooling device for cooling the heating tube for filling is provided behind the resin outlet in the heating tube for filling, the cooling device for the resin outlet is provided. Since the periphery and the shaft of the filling plunger are cooled, the resin adhered to the shaft is in an appropriately cured state and can be easily separated from the shaft.

According to the invention described in claim 7, the diameter of the shaft hole through which the filling plunger of the filling heating cylinder is inserted is set to the diameter of the cylinder hole in which the head of the filling plunger of the filling heating cylinder slides. Therefore, the resin can be appropriately set, and the resin can be reliably scraped from the cylinder hole and the head of the filling plunger. According to the eighth aspect of the present invention, the resin adhered to the shaft portion of the filling plunger can be easily peeled off and discharged to the resin outlet by the resin adhesion preventing process performed on the shaft portion of the filling plunger.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a filling heating cylinder in a pre-plastic injection molding machine of the present invention.

FIG. 2 is a plan view showing an embodiment of a filling heating cylinder in the pre-plastic injection molding machine of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a cross-sectional view showing another embodiment of the filling heating cylinder in the pre-plastic injection molding machine of the present invention.

FIG. 5 is a cross-sectional view of an injection device according to an embodiment in which the present invention is applied to a screw pre-plastic injection molding machine.

[Explanation of symbols]

Reference Signs List 3 plasticization measuring mechanism 4 injection mechanism 5 injection device 7 heating cylinder for plasticization 8 plasticizing screw 11 heating cylinder for filling 11a resin reservoir 11b cylinder hole 13 filling plunger 13a head 13b shaft 15 filling cylinder 16 resin outlet 16a Vertical discharge port 16b, 16f Horizontal discharge port 16c Projection 21 Shaft hole 22 Cylinder sleeve

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kiichi Shimada 1300, Okayama, Niigata City, Niigata Prefecture Inside the Niigata Iron Works, Ltd.Niigata Seiki Factory (72) Inventor Yukio Yoshizawa 1300, Okayama, Niigata City, Niigata Prefecture Niigata Technica Co., Ltd. (72) Inventor Masakazu Ohno 2-11-14 Kugahara, Ota-ku, Tokyo Sankyo Chemical Co., Ltd. (56) References JP-A-8-138078 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) B29C 45/46-45/54

Claims (8)

(57) [Claims] 1. A plasticizing heating cylinder for plasticizing a resin material, a filling heating cylinder for measuring a resin melted in the plasticizing heating cylinder into a resin reservoir of a cylinder hole, and a filling heating cylinder. A filling plunger in which a head portion is inserted into the cylinder hole of the cylinder so as to be able to move back and forth, and injects the measured molten resin into a cavity of a mold; In a pre-plastic injection molding machine provided with a resin outlet for discharging the resin attached around the filling plunger at a position behind the head portion at the position, the resin outlet is a diameter of the filling heating cylinder. A vertical discharge port penetrating vertically through the entire length of the cylinder hole and leading to the outside of the cylinder hole, and a horizontal discharge port directed to a direction intersecting the vertical discharge port and leading to the outside of the cylinder hole. Pre-plasticization type injection molding machine, characterized in that Ranaru. 2. The pre-plastic injection according to claim 1, wherein the resin discharge port is formed symmetrically with respect to a plane along a vertical direction passing through the center of a cylinder hole of the filling heating cylinder. Molding machine. 3. An inner peripheral portion of at least one of a vertical discharge port and a horizontal discharge port in the resin discharge port has at least one of a front surface and a rear surface in an axial direction of the filling plunger,
3. The pre-plastic injection molding machine according to claim 1, wherein the projection is provided in the axial direction. 4. The resin discharge port according to claim 1, wherein an inner peripheral front surface of the resin discharge port is provided in front of a rear end position of the head portion at a rear end position of the filling plunger. Item 4. A pre-plastic injection molding machine according to any one of Items 3. 5. The pre-plasticizing method according to claim 1, wherein the resin discharge port has a vertical discharge port formed to have a diameter larger than the diameter of the cylinder hole. Injection molding machine. 6. A cooling device for cooling the heating tube for filling, which is provided behind the resin outlet, in the heating tube for filling.
A prepra-type injection molding machine according to item 1. 7. A diameter of a shaft hole through which a filling plunger of the filling heating cylinder is inserted is larger by 0.05 to 0.5 mm than a diameter of a cylinder hole in which a head portion of the filling plunger of the filling heating cylinder slides. The pre-plastic injection molding machine according to any one of claims 1 to 6, wherein the injection molding machine is formed. 8. A pre-plastic injection according to claim 1, wherein the filling plunger is subjected to a resin adhesion preventing treatment on a shaft portion behind a head portion. Molding machine.