JP2915760B2 - Local pressurized 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 local pressurized injection molding machine.

[0002]

2. Description of the Related Art Conventionally, various processes are performed on a molded product by pressurizing a local portion of a resin in a cavity, and a local pressurizing method which does not require drilling of a thin plate after molding and finishing of a cut surface. Is provided. FIG. 2 is a view showing a main part of a conventional local pressurization type injection molding machine.
In the figure, (a) shows a molding state, (b) shows a punch vibration state,
(C) shows a vibration punching state.

In the drawing, reference numeral 1 denotes a fixed mold attached to a fixed platen (not shown), 2 denotes a movable mold attached to a movable platen (not shown), and 3 denotes a mold formed between the fixed mold 1 and the movable mold 2. 4 is a sprue to which resin injected from an injection nozzle (not shown) is fed.
Is a gate formed between the sprue 4 and the cavity 3, 6 is a fixed side punch disposed on the fixed mold 1 side,
Reference numeral 7 denotes a movable punch provided on the movable mold 2 side.

The fixed punch 6 and the movable punch 7
Is vibrated by a vibration device (not shown) disposed in the fixed mold 1 and the movable mold 2 during a cooling step after the pressure holding step of the injection molding cycle is completed. Since the fixed-side punch 6 and the movable-side punch 7 are provided in advance at a location to be processed, as shown in FIG.
When the movable-side punch 7 is vibrated, heat is generated by shearing stress in a processing portion (a hole or a gate 5) sandwiched between the fixed-side punch 6 and the movable-side punch 7, and the resin is softened. I do.

When the movable punch 7 is projected in one direction as shown in FIG. 2B while the fixed punch 6 and the movable punch 7 are vibrated, the softened resin is shown in FIG. To be cut off. In this case, the portion cut along the movable-side punch 7 is finished by vibration and cooled, so that a glossy and highly-accurate processed surface can be obtained.

[0006]

However, in the above-mentioned conventional local pressurized injection molding machine, an actuator which is a fixed side punch 6 in a fixed mold 1 is provided with a movable mold 2.
Since the actuator serving as the movable-side punch 7 is provided in the inside, the cost increases. The present invention solves the problems of the conventional local pressurized injection molding machine, and places the actuator outside the fixed mold and the movable mold to reduce the cost. The purpose is to provide.

[0007]

For this purpose, in a local pressurized injection molding machine according to the present invention, a fixed mold and a fixed mold are disposed so as to be able to freely contact with and separate from the fixed mold, and a cavity is formed between the two. And a movable mold. Then, a pressure pin extends through the movable mold and makes the tip face at least one of the resin flow path and the cavity. Further, a pressing cylinder is disposed behind the pressing pin, and the pressing cylinder moves the pressing pin via a pressing rod.

[0008] On the other hand, an ejector pin extends through the movable mold so that the tip faces the cavity. An ejector cylinder is disposed behind the ejector pin, and the ejector cylinder moves the ejector pin via an ejector rod. Further, the pressure rod and the ejector rod can be arranged coaxially.

Further, a plurality of the pressure rods are provided,
Each pressure rod can be synchronized by a pressure crosshead. Then, a plate is provided on the mold mounting surface of the movable platen, and a pressing cylinder is provided behind the plate and the pressing pin, and the pressing cylinder moves the pressing pin via a pressing rod. Let it. An ejector cylinder is disposed behind the movable platen, the plate, and the ejector pin, and the ejector cylinder moves the ejector pin via an ejector rod.

The pressure rod and the ejector rod are coaxially arranged.

[0011]

According to the present invention, as described above, the injection molding machine of the local pressurization type is provided with a fixed mold and a movable mold which is disposed so as to be able to contact and separate from the fixed mold and forms a cavity between the two. And A molded article can be formed by filling the resin with the cavity.

Then, a pressure pin extends through the movable mold and makes the tip face at least one of the resin flow path and the cavity. Further, a pressing cylinder is disposed behind the pressing pin, and the pressing cylinder moves the pressing pin via a pressing rod. Therefore, the resin after filling can be pressurized by advancing the pressure pin into a resin flow path such as a gate or a cavity,
Not only can a very thin molded product be obtained, but also the occurrence of sink marks can be prevented.

[0013] An ejector pin extends through the movable mold so that the tip faces the cavity. An ejector cylinder is disposed behind the ejector pin, and the ejector cylinder moves the ejector pin via an ejector rod. Therefore, the actuators of the pressure pin and the ejector pin can be disposed outside the fixed mold or the movable mold.

The use area of the movable platen can be reduced by arranging the pressure rod and the ejector rod coaxially. Further, since a plurality of the pressure rods are provided and the pressure rods are synchronized by the pressure crosshead, it is possible to prevent the pressure plate from falling down.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of a local pressurized injection molding machine showing a first embodiment of the present invention. FIG. 3 is a side view of a local pressurized injection molding machine showing a first embodiment of the present invention.
4 is a sectional view taken along line BB of FIG. 1, and FIG. 5 is an enlarged view of a main part of FIG. FIG. 1 is a sectional view taken along line AA of FIG.

In FIG. 1, reference numeral 12 denotes a fixed die, which is attached to a fixed platen (not shown). Reference numeral 13 denotes a movable die which is disposed to face the fixed die 12, is moved forward and backward (moves in the left-right direction in the figure) by a mold clamping device (not shown), and is brought into and away from the fixed die 12. The movable mold 13
Is fixed to the movable platen 15 via the spacer block 14. Here, for convenience, the spacer block 14 is used.
Is drawn integrally with the movable mold 13. The movable platen 15 is advanced and retracted along four tie bars 40 by a mold opening / closing device (not shown).

In the injection step, the resin injected from the injection nozzle of the injection device (not shown)
From 8, a runner 19 is passed through a gate 20 such as a submarine gate to fill a cavity 21 formed between the fixed mold 12 and the movable mold 13. When the injection step is completed, a pressure-holding step is started, and the pressure inside the cavity 21 is increased to prevent the molded product from sinking due to cooling of the resin. Subsequently, a cooling step is started, and cooling of the resin in the cavity 21 is started.

In the meantime, the same number of the pressing pins 33 as the gates 20 are provided in order to cut the gate during the pressure-holding step or at the initial stage of the cooling step. The pressure pin 33 has an area corresponding to the end of the gate 20 at the tip end, and is disposed at a position where the gate is cut by the pressure pin 33 itself when it advances. Therefore, since the pressure pin 33 itself has a structure for gate cutting, the fixed mold 12
In addition, the structure of the movable mold 13 can be simplified. The pressing pin 33 has its rear end sandwiched and fixed by the pressing plate 36, and the pressing pin 33 is moved forward and backward by moving the pressing plate 36 forward and backward.

The spacer block 14 has a regulating member so that the pressing plate 36 moves only within a predetermined range. In the figure, the solid line indicates the retreat limit of the pressure plate 36 and the two-dot chain line indicates the limit of advance of the pressure plate 36. As shown in FIGS. 1 and 3, the movable platen 15 is provided with two pressurizing cylinders 41 on a diagonal line connecting the two tie bars 40, and the pressurizing cylinder 41 is operated by operating the pressurizing cylinders 41. The pin 33 is moved forward and backward. Therefore, the piston rod 42 of the pressurizing cylinder 41
Are fixed to the pressing crosshead 43 by bolts 44, and four sleeve-shaped pressing rods 46 are fixed to the pressing crosshead 43, and project forward (to the right in the drawing). On the other hand, a sleeve-like projection 47 is formed on the pressure plate 36 at a portion corresponding to the end surface of the pressure rod 46, and extends rearward (to the left in the drawing). Incidentally, it is not always necessary to dispose the four pressure rods 46, and the pressure rods 46 can be increased or decreased as necessary.

Accordingly, when the piston rod 42 is moved forward by operating the pressure cylinder 41, the pressure rod 46 is moved forward via the pressure crosshead 43.
The tip of the pressure rod 46 is the sleeve-like projection 4.
When the piston rod 42 is further advanced by further operating the pressurizing cylinder 41 after that, the pressurizing pin 33 is advanced through the pressurizing plate 36.

Since the pressing rod 46 is sandwiched and fixed by the pressing crosshead 43, the four pressing rods 46 can be moved forward in synchronization by operating the pressing cylinder 41. it can.
In this way, the pressure plate 36 can be prevented from falling down, and the pressure plate 36 and the pressure pins 33 can be prevented from being damaged. In addition, it is possible to reduce the variation in the movement stroke of each pressing pin 33 and make the pressing force uniform.

One ejector pin 51 has a tip facing the sprue 18, and a plurality of ejector pins 52 have a tip facing a predetermined portion of the cavity 21.
Are disposed, and the rear ends of the ejector pins 51 and 52 are sandwiched and fixed by the ejector plate 53. The spacer block 14 has a regulating member such that the ejector plate 53 moves only within a predetermined range. As in the case of the pressure plate 36, the solid line in the figure indicates the retreat limit of the ejector plate 53, and the two-dot chain line indicates the limit of advance of the ejector plate 53.

An ejector cylinder 55 is provided at the center of the movable platen 15. The ejector pins 51, 5 are operated by operating the ejector cylinder 55.
2 is advanced and retreated. Therefore, an ejector crosshead 57 is fixed to the piston rod 56 of the ejector cylinder 55, and one ejector rod 5 is provided at the center of the ejector crosshead 57 as shown in FIG.
8 is also located at a position corresponding to the pressure rod 46.
The ejector rod 59 is fixed and protrudes forward. The ejector rod 59 is connected to the pressurizing rod 4.
6 is provided.

On the other hand, the ejector plate 53 has
As shown in FIG. 5, protrusions 60 and 61 are formed to project from portions corresponding to the ejector rods 58 and 59,
Extends backwards. Therefore, when the ejector cylinder 55 is operated to advance the piston rod 56,
The ejector rods 58, 59 advance through the ejector crosshead 57. Then, when the tip ends of the ejector rods 58, 59 abut against the protrusions 60, 61, and thereafter the ejector cylinder 55 is further operated to advance the piston rod 56, the ejector plate 53
The ejector pins 51 and 52 are moved forward through.

The ejector cylinder 55 has a flange portion 55a projecting radially outward, and the pressurizing cylinder 41 is fixed to the flange portion 55a. The pressurizing cylinder 41 and the ejector cylinder 55 are operated by hydraulic pressure, and the pressurizing cylinder 41 and the hydraulic source 71 are connected via an electromagnetic switching valve 73, and the ejector cylinder 55 and the hydraulic source 71 are connected via an electromagnetic switching valve 74. Connected. Each of the electromagnetic switching valves 73 and 74 can take the A position, the B position and the neutral position, and moves the piston rods 42 and 56 forward at the A position and retracts at the B position.

When the ejector rods 58, 59 are retracted by a predetermined amount by retracting the piston rod 56, the distal ends of the ejector rods 58, 59 are separated from the ejector plate 53, and the ejector plate 53 is further retracted. Can not do. Also,
Similarly, when the pressing rod 46 is retracted by a predetermined amount by retracting the piston rod 42, the tip of the pressing rod 46 is separated from the pressing plate 36, and the pressing plate 36 cannot be further retracted.

Therefore, a return pin 65 and a return spring 66 are provided between the ejector plate 53 and the fixed mold 12. Accordingly, the ejector plate 53 is guided by the return pin 65 as the ejector rods 58, 59 are retracted, and is forcibly retracted by the return spring 66.

A return pin 67 and a return spring 68 are also provided between the pressure plate 36 and the fixed mold 12. Therefore, the pressure plate 36 is guided by the return pin 67 as the pressure rod 46 retreats, and is forcibly retracted by the return spring 68. In the locally pressurized injection molding machine having the above-described configuration, the movable platen 15 moves forward to close and close the mold, and the resin is injected from an injection nozzle (not shown). The resin is filled into the cavity 21 via the sprue 18, the runner 19 and the gate 20.

Next, when the solenoid a of the electromagnetic switching valve 73 is energized during the pressure holding step in which the pressure of the resin is held or in the initial stage of the cooling step of cooling the resin in the cavity 21, The piston rod 42 of the pressure cylinder 41 moves forward. At this time, the pressure crosshead 43 and the pressure rod 46 fixed to the piston rod 42 also advance, and the pressure rod 46 pushes the pressure plate 36. The pressing pin 33 attached to the pressing plate 36
Pushes the resin in the gate 20 and the gate is cut.

After the cooling step is completed and the mold is opened,
The solenoid a of the electromagnetic switching valve 74 is excited, and the piston rod 56 of the ejector cylinder 55 moves forward. At this time, the ejector crosshead 57 fixed to the piston rod 56 and the ejector rods 58, 59 also move forward, and the ejector rods 58, 59 push the ejector plate 53. Then, the ejector plate 53
The ejector pins 51 and 52 attached to the sprue push the sprue 18 and a molded product (not shown), and
8 and the runner 19 are protruded.

The runner 19 and the molded product can be separated from each other by projecting the sprue 18 and the runner 19 and projecting the molded product at different timings. Can be simplified. As described above, the pressing rod 46
Is shaped like a sleeve, and an ejector rod 59 extends through the inside of the pressure rod 46. Therefore, in the movable platen 15, the pressing rod 4
6 and the ejector rod 59 are coaxially arranged, so that the space for the pressure rod 46 can be easily secured.

In general, in a direct pressure type mold clamping device in which the mold is opened and closed by a hydraulic cylinder, a column (not shown) for transmitting a mold clamping force is provided behind the mold mounting surface of the movable platen 15. Therefore, it is extremely difficult to newly provide a pressurizing device in addition to the normal ejecting device. In the present invention, in the movable platen 15, the ejector rod 59 of the projecting device and the pressing rod 46 of the pressing device are coaxially arranged. Therefore, the pressurizing device can be easily provided.

Since the resin after filling can be pressurized by the pressurizing device, not only a very thin molded product can be obtained, but also the occurrence of sink marks can be prevented. Next, a second embodiment of the present invention will be described. FIG. 6 is a cross-sectional view of a main part of a locally pressurized injection molding machine showing a second embodiment of the present invention, and FIG. 7 is a cross-sectional view taken along line CC of FIG.

In the drawing, 15 is a movable platen, 40 is a tie bar, 71 is an ejector cylinder, and 72 is a guide post for supporting the ejector cylinder 71.
A crosshead 74 is fixed to the piston rod 73 of the ejector cylinder 71, and ejector pins 75 and 76 are fixed to the crosshead 74 and project forward (to the right in the drawing).

On the other hand, a plate 77 is fixed by bolts 78 to the movable platen 15 on the side of a mold mounting plate (not shown). A hole 79 through which the ejector pin 75 passes is formed in the center of the plate 77, and pressurizing cylinders 81 are disposed at four places around the hole 79. The pressurizing cylinder 81 has a sleeve-like piston 82 having a large diameter at a central portion, and a front end face of the piston 82 comes into contact with a pressurizing pin (not shown). Further, the ejector pin 76 penetrates through the piston 82.

The oil chamber of the pressurizing cylinder 81 is connected to an electromagnetic switching valve 83. By switching the electromagnetic switching valve 83, the piston 82 and the pressure pin can be moved forward and backward. Reference numeral 84 denotes an oil passage for supplying and discharging oil to and from the oil chamber of the pressurizing cylinder 81. Next, a third embodiment of the present invention will be described.

FIG. 8 is a front view of a movable platen of a locally pressurized injection molding machine showing a third embodiment of the present invention. FIG. 9 is a locally pressurized injection molding machine showing a third embodiment of the present invention. FIG. 10 is a cross-sectional view of the movable platen taken along line DD in FIG. 10, and FIG.
FIG. 11 is a sectional view of an ejector pin and a pressure pin in a locally pressurized injection molding machine showing a third embodiment of the present invention.

In the drawing, 15 is a movable platen, 40 is a tie bar, 85 is an ejector cylinder, 86 is a pressurizing cylinder, 87 is a guide post that supports the ejector cylinder 85, and 88 is a pressurizing cylinder that supports the pressurizing cylinder 86. It is a guide post. As shown in FIG. 10, a crosshead 89 is fixed to the piston rod of the ejector cylinder 85, and an ejector rod 90 is fixed to the crosshead 89 and protrudes forward (to the right in the drawing). Further, as shown in FIG.
The crosshead 91 is fixed to the piston rod of No. 6,
A pressure rod 92 is fixed to the crosshead 91 and protrudes forward.

In this case, the ejector rod 90 and the pressure rod 92 are not coaxial but are arranged at different positions. In this embodiment, the pressing pin 33 is used.
(FIG. 1) is disposed facing the gate 20, and the pressing pin 33 is provided.
Although the gate is cut by the method, when the resin is simply pressed, the resin can be exposed to another resin flow path such as the runner 19 and the cavity 21.

Next, a fourth embodiment of the present invention will be described. FIG. 12 is a sectional view of a main part of a locally pressurized injection molding machine showing a fourth embodiment of the present invention. In the figure, reference numeral 15 denotes a movable platen, 59 denotes an ejector rod, and 101 denotes a plurality of pressurizing cylinders provided on the movable platen 15.

A sleeve-like pressurizing piston 102 is slidably disposed in the pressurizing cylinder 101, and a sleeve-like pressurizing piston 102 is provided in front of the pressurizing piston 102 (to the right in the figure). The rod 103 is formed integrally. In this case, the pressing crosshead 43 (FIG. 1) as in the first embodiment is not required. Further, each pressurizing cylinder 101 can be independently controlled, and can be operated with different operation timings and pressurization programs.

Next, a fifth embodiment of the present invention will be described. FIG. 13 is a sectional view of a main part of a locally pressurized injection molding machine showing a fifth embodiment of the present invention. In the drawing, reference numeral 15 denotes a movable platen, 59 denotes an ejector rod, and 111 denotes a plurality of pressurizing cylinders provided on the movable platen 15.

In the pressurizing cylinder 111, a pressurizing piston 112 is slidably disposed.
A pressure rod 113 is integrally formed in front of (to the right in the figure) 12. In this case, the pressing crosshead 43 (FIG. 1) as in the first embodiment is not required. Also,
Each pressurizing cylinder 111 can be independently controlled, and can be operated with different operation timings and pressurization programs.

Next, a sixth embodiment of the present invention will be described. FIG. 14 is a sectional view of a main part of an injection molding machine of a local pressurization type showing a sixth embodiment of the present invention. In the figure, 15 is a movable platen, 55 is an ejector cylinder, 56 is a piston rod, 57 is an ejector crosshead, 5
8, 59 are ejector rods.

Reference numeral 121 denotes a plurality of pressurizing cylinders provided on the movable platen 15. A pressurizing piston 122 is slidably disposed in the pressurizing cylinder 121, and a piston rod 123 is integrally formed behind (to the left in the figure) the pressurizing piston 122. At the rear end of the piston rod 123, a pressurizing crosshead 125 is disposed. By operating the pressurizing cylinder 121, the pressurizing crosshead 125 can be moved forward and backward.

On the other hand, in front of the movable platen 15 (to the right in the figure), a pressing plate 127 is disposed so as to be able to advance and retreat, and the rear end of the pressing pin 128 is fixed to the pressing plate 127. The pressure plate 127 and the pressure crosshead 125 are connected by a pressure rod 130. In this case, the pressure rod 130 is provided outside the periphery of the movable platen 15 without penetrating the movable platen 15.

Next, a seventh embodiment of the present invention will be described. FIG. 15 is a sectional view of a main part of a locally pressurized injection molding machine showing a seventh embodiment of the present invention. In the figure, 15 is a movable platen, 55 is an ejector cylinder, 56 is a piston rod, 57 is an ejector crosshead, 59
Is an ejector rod.

Reference numeral 131 denotes a plurality of pressurizing cylinders arranged on the periphery of the movable platen 15. A pressurizing piston (not shown) is slidably disposed in the pressurizing cylinder 131, and a pressurizing rod 133 is integrally formed in front of the pressurizing piston (to the right in the drawing). A pressure plate 127 is fixed to a front end of the pressure rod 133, and a rear end of the pressure pin 128 is fixed to the pressure plate 127. In this case, the pressure rod 133 does not penetrate the movable platen 15.

The pressing rods 46, 92, 103, 113, 130, and 133 in the above embodiments can be used for core tractors, core rotation, and the like. FIG. 16 is a diagram showing an application example of the pressure rod. In the figure, 1
50 is a movable platen, 151 is a pressure rod, 152 is a pressure plate, 153 is an angular pin, 154 is a slide core, and 156 is a molded product.

In this case, the angular pin 153 is moved forward and backward by the pressing rod 151, and
4 can be moved. Therefore, a special mechanism for moving the slide core 154 becomes unnecessary,
The structure can be simplified. It should be noted that the present invention is not limited to the above-described embodiments, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0051]

As described above in detail, according to the present invention, the local pressurizing type injection molding machine is provided with a fixed mold and a fixed mold so as to be able to freely contact with and separate from the fixed mold. And a movable mold for forming the same. A molded article can be formed by filling the cavity with a resin.

Then, a pressure pin extends through the movable mold and makes the tip face at least one of the resin flow path and the cavity. Further, a pressing cylinder is disposed behind the pressing pin, and the pressing cylinder moves the pressing pin via a pressing rod. Therefore, the resin after filling can be pressurized by advancing the pressure pin into a resin flow path such as a gate or a cavity,
Not only can a very thin molded product be obtained, but also sink marks can be prevented.

An ejector pin extends through the movable mold so that the tip faces the cavity. An ejector cylinder is disposed behind the ejector pin, and the ejector cylinder moves the ejector pin via an ejector rod. Therefore, since the actuators of the pressure pin and the ejector pin can be disposed outside the fixed mold and the movable mold, the cost of the fixed mold and the movable mold can be reduced.

By arranging the pressure rod and the ejector rod coaxially, the use area of the movable platen can be reduced, and the mountability is improved.
Further, since a plurality of the pressure rods are provided and each pressure rod is synchronized by the pressure crosshead, it is possible to prevent the pressure plate from falling down, Pins and the like can be prevented from being damaged. In addition, it is possible to reduce the variation in the movement stroke of each pressure pin and make the pressing force uniform.

[Brief description of the drawings]

FIG. 1 is a sectional view of a locally pressurized injection molding machine showing a first embodiment of the present invention.

FIG. 2 is a view showing a main part of a conventional local pressurization type injection molding machine.

FIG. 3 is a side view of a locally pressurized injection molding machine showing the first embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is an enlarged view of a main part of FIG. 1;

FIG. 6 is a sectional view of a main part of a locally pressurized injection molding machine showing a second embodiment of the present invention.

FIG. 7 is a sectional view taken along the line CC of FIG. 6;

FIG. 8 is a front view of a movable platen of a locally pressurized injection molding machine according to a third embodiment of the present invention.

FIG. 9 is a cross-sectional view of the movable platen of the injection molding machine of the third embodiment of the present invention, taken along the line DD.

FIG. 10 is an EE cross-sectional view of a movable platen of a locally pressurized injection molding machine showing a third embodiment of the present invention.

FIG. 11 is an arrangement diagram of ejector pins and pressure pins in a locally pressurized injection molding machine showing a third embodiment of the present invention.

FIG. 12 is a sectional view of a main part of a locally pressurized injection molding machine showing a fourth embodiment of the present invention.

FIG. 13 is a sectional view of a main part of a locally pressurized injection molding machine showing a fifth embodiment of the present invention.

FIG. 14 is a sectional view of a main part of a locally pressurized injection molding machine showing a sixth embodiment of the present invention.

FIG. 15 is a sectional view of a main part of a locally pressurized injection molding machine showing a seventh embodiment of the present invention.

FIG. 16 is a diagram showing an application example of a pressure rod.

[Explanation of symbols]

12 Fixed mold 13 Movable mold 15, 150 Movable platen 21 Cavity 33, 128 Pressure pin 41, 81, 86, 101, 111, 121, 131
Cylinder for pressurization 43,125 Crosshead for pressurization 46,92,103,113,130,133,151
Pressing rod 51, 52, 75, 76 Ejector pin 55, 71, 85 Ejector cylinder 58, 59, 90 Ejector rod 77 Plate

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-151013 (JP, A) Japanese Utility Model Application No. 5-58248 (JP, U) Japanese Utility Model Application Model No. 5-192976 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) B29C 45/56-45/58 B29C 45/26-45/40 B29C 33/42-33/44

Claims (4)

(57) [Claims] 1. A fixed mold, (b) a movable mold which is disposed so as to be able to contact and separate from the fixed mold and forms a cavity therebetween, and (c) penetrates the movable mold. And (d) a pressure pin disposed behind the pressure pin and moving the pressure pin via a pressure rod. A cylinder, (e) an ejector pin extending through the movable mold and having a tip facing the cavity, and (f) disposed behind the ejector pin, and moving the ejector pin via an ejector rod. An injection molding machine of a local pressurization type, comprising an ejector cylinder. 2. The injection molding machine according to claim 1, wherein the pressure rod and the ejector rod are arranged coaxially. 3. The injection molding machine according to claim 1, wherein a plurality of the pressure rods are provided, and each of the pressure rods is synchronized by a pressure crosshead. 4. A fixed mold, (b) a movable mold that is disposed so as to be able to contact and separate from the fixed mold and forms a cavity therebetween, and (c) penetrates the movable mold. (D) a plate disposed on the mold mounting surface of the movable platen, (e) a plate and the pressure pin. A pressurizing cylinder disposed behind the pressurizing rod for moving a pressurizing pin via a pressurizing rod; and (f) an ejector pin extending through the movable mold and having a tip facing the cavity.
(G) an ejector cylinder that is disposed behind the movable platen, the plate, and the ejector pin and moves the ejector pin through an ejector rod; and (h) the pressurizing rod and the ejector rod are coaxial. A locally pressurized injection molding machine, which is disposed above.