JPH043769Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an injection molding apparatus that simultaneously performs injection molding using a mold clamping pressure device.

[Prior art] Traditionally, rubber injection molding involves clamping a split mold with a mold clamping device that uses a drive device such as a hydraulic cylinder device, then putting rubber molding material into a transfer chamber, and then pouring another molding material into a transfer chamber. This is done by press-fitting the molding material into the cavity using a plunger connected to a hydraulic cylinder device or the like. Therefore, two types of pressure equipment such as hydraulic cylinder equipment are required, one for mold clamping and one for press fitting, which makes the equipment larger and more complex, and requires two processes: mold clamping and press fitting, resulting in a large number of processes. I was getting used to it.

[Problems to be solved by the invention] In order to solve the above-mentioned problems, the inventors of the present invention planned to construct a device that performs mold clamping and injection molding using one pressure device, and as a result of intensive research, they developed the present invention. This is the completed injection molding device.

[Means for Solving the Problems] In other words, the injection molding apparatus of the present invention has a substantially C-shape in side view, having a lower base portion and an upper base portion facing the lower base portion, and a lower mold is held on the upper surface of the lower base portion. At the same time, a base body having a driving device fixed to the upper surface of the upper stage, a flat injection plate disposed below the upper stage so as to be movable in the vertical direction by the drive of the driving device, and a base body provided on the lower surface of the injection plate and arranged downwardly. a plunger protruding from the base; a flat intermediate plate that is movable only in the vertical direction along a guide rod provided on the base and disposed below the injection plate so as to be able to come into contact with the injection plate; an upper mold having a cylinder part held on the lower surface of the plate and communicating with a hole in the intermediate plate, into which a molding material is placed and into which a plunger is inserted; The shaft protruding from above is inserted into a through hole provided in the injection plate, and a locking member provided at a portion protruding upward from the through hole restricts the distance of downward movement under its own weight and allows the shaft to move upwardly from the injection plate. It is connected to the injection plate so as to move in conjunction with the movement of the injection plate, and is inserted into the through hole of the injection plate so as to be able to move up and down, protrudes downward, and urges the knock rod that is locked on the upper surface side of the injection plate and the knock rod downward. The present invention is characterized in that it is provided with a biasing member that provides a force for separating the plunger from the cylinder portion when the mold is opened, and biases the intermediate plate in a direction away from the injection plate.

The drive device consists of a hydraulic cylinder, a pneumatic cylinder, etc., and by lowering the injection plate fixed to the driving part of the drive device such as a piston rod, the molding material is forced into the cavity with a plunger fixed to the lower surface of the injection plate. It also has the function of clamping the upper mold fixed to the lower surface of the intermediate plate and the lower mold held on the upper surface of the lower part of the base.

In the molding apparatus of the present invention, the intermediate plate is disposed below the injection plate so as to be able to come into contact with the injection plate and to be movable only in the vertical direction along a guide rod provided on the base body. The injection plate is provided with a through hole that penetrates in the vertical direction, the intermediate plate is provided with a shaft that projects upward, the shaft is inserted into the through hole of the injection plate, and a locking member is provided at the tip of the shaft. With this configuration, the intermediate plate automatically moves downward due to its own weight and the weight of the upper mold held by the intermediate plate, and the distance of downward movement is regulated by the contact between the locking member and the injection plate. has been done. Further, when opening the mold, after the locking member and the injection plate come into contact with each other, the intermediate plate moves upward in conjunction with the upward movement of the injection plate.

During mold clamping, when the injection plate is lowered by the drive of the drive device, the intermediate plate is lowered together with the upper mold due to its own weight, and the upper mold and the lower mold come into contact with each other to align the molds. When the injection plate descends even after the biasing member comes into contact with the intermediate plate, the plunger is inserted into the cylinder part provided in the upper mold through the hole in the intermediate plate and pours the molding material that was previously put into the cylinder part. While being press-fitted into the cavity, the upper and lower molds are further clamped together.

When the injection plate rises after completion of rubber injection molding and vulcanization molding (when the mold opens), the intermediate plate is urged downward by its own weight and the upper mold's own weight, so the injection plate moves away from the intermediate plate. Only the injection plate moves upward so that the plunger is pulled out from the cylinder part.
However, the clearance between the cylinder section and the plunger is generally extremely small, and if the axial direction of the cylinder section and the axial direction of the plunger deviate due to manufacturing errors, the molding material will flow back into the gap and close the gap. It is conceivable that the injection plate and the intermediate plate may move together, with the cylinder part and the plunger being fixed together.
Such a problem is likely to occur, for example, when the cylinder portion is not located at the center of the upper mold but is eccentric. In such a case, the next molding process cannot be performed,
Furthermore, the intermediate plate may suddenly separate from the injection plate during the ascent, which poses a safety problem.

Therefore, in the molding device of the present invention, the intermediate plate is arranged to be movable up and down and moved downward by its own weight, and at the same time, when the mold is opened, a force is provided to separate the plunger from the inside of the cylinder, thereby separating the intermediate plate from the injection plate. The device is equipped with a biasing member that biases in the direction. In other words, at the initial stage when the injection plate starts to rise,
This biasing member urges the injection plate in a direction away from the intermediate plate to raise only the injection plate, and the plunger is pulled out from the cylinder portion before the upper mold and the lower mold are separated.

[Operation] In the injection molding apparatus of the present invention, the drive device is first driven to lower the injection plate during molding. At this time, the intermediate plate is located at a lower position due to its own weight, and since the locking member and the injection plate are locked, the intermediate plate also descends as the injection plate descends. Then, the upper mold and the lower mold are matched, and the molds are clamped by the weight of the upper mold and the weight of the intermediate plate. In addition, a plunger fixed to the lower surface of the injection plate is inserted into a cylinder provided in the upper mold through a hole in the intermediate plate, and the molding material that has been previously charged into the cylinder is press-fitted into the cavity by the plunger. do. Then, the injection plate further descends against the biasing force of the biasing member, press-fits the molding material, and clamps the mold, completing the injection molding.

After injection molding and vulcanization molding are completed, the injection plate is raised by driving the drive device. At this time, the biasing member biases the intermediate plate in a direction away from the injection plate, providing a tight trigger to pull out the plunger from within the cylinder portion. After that, first only the injection plate rises, the plunger is pulled out from the cylinder part, and after the upper surface of the injection plate and the locking member come into contact, the intermediate plate also rises, and the upper and lower molds are opened. , the molded body is taken out and the next molding is performed.

[Effects of the invention] According to the injection molding device of the present invention, mold clamping and injection molding can be performed with a single driving device such as a cylinder, so the device can be downsized, saving installation space and cost. It is advantageous. The plunger and cylinder part are reliably separated by the biasing member before the upper mold and lower mold open, and then the upper mold and lower mold open, so that the plunger and the cylinder part are fixed and integrated. This prevents the intermediate plate from rising and causes problems such as the intermediate plate falling during mold opening, resulting in excellent maintainability and safety.

[Example] The following is a concrete explanation using Examples. FIG. 1 shows a front view of the injection molding apparatus of this embodiment, and FIG. 2 shows a side view thereof. Note that in order to show the main parts, lines that hide the main parts are omitted.

The apparatus of this embodiment has a lower mold 1 on the upper surface of the lower base part 1a.
A base body 1 having a substantially C-shape in side view has a hydraulic cylinder 2 as a drive device fixed to the upper surface of the upper base part 1b, and a lower end of the piston rod 21 of the hydraulic cylinder 2 below the upper base part 1b. a flat injection plate 3 which is fixed and movable in the vertical direction by driving the hydraulic cylinder 2;
2 fixed to the lower surface of the injection plate 3 and protruding downward
The plunger 4 is movable only in the vertical direction along a guide rod 11 provided on the base body 1 to extend in the vertical direction, and is disposed below the injection plate 3 so as to be able to come into contact with the injection plate 3. The cylinder part 103 is held on the lower surface of the intermediate plate 5, communicates with a hole in the intermediate plate 5, contains a molding material therein, and into which the plunger 4 is inserted. The upper mold 102 has an upper mold 102, and the biasing member 6 is provided at the lower part of the injection plate 3 and is composed of a spring 62 and a knock rod 61.

The intermediate plate 5 is supported so as to be movable only in the vertical direction by inserting a guide rod 11 provided in the base body 1 into a through hole (not shown) provided at one end thereof. Further, a shaft 51 that projects upward is fixed to the intermediate plate 5,
This shaft 51 is inserted into a through hole 31 provided in the injection plate 3 from below. The shaft 51 that protrudes upward from the through hole 31 has a
A locking member 52 having a diameter larger than the diameter of the through hole 31 is screwed by a nut 53. That is, the intermediate plate 5 is restricted from moving downward due to its own weight by the locking member 52 .

The biasing member 6 includes a knock rod 61 that is inserted into a through hole 32 provided in the injection plate 3 and is locked on the upper surface side of the injection plate 3, and a knock rod 61 that has one end locked in the through hole 32 and the other end. The springs 62 are fixed to the lower ends of the springs 62 and urge the knock rods 61 downward, and are provided at each of the four corners of the injection plate 3, which has a rectangular cross section.

(Operation of the embodiment device) The operation of the device of this embodiment will be explained below.

During molding, the hydraulic cylinder 2 is driven, and as the piston rod 21 is lowered, the injection plate 3 is lowered. Further, since the locking member 52 of the intermediate plate 5 is locked with the injection plate 3 at the upper end of the shaft 51, the intermediate plate 5 and the upper mold are locked until the upper mold 102 held on the lower surface comes into contact with the lower mold 101. 102 descends together with the injection plate 3 due to its own weight.

When the upper mold 102 comes into contact with the lower mold 101 and the molds are matched, the intermediate plate 5 stops lowering, the locking member 52 is released, and the upper mold 102 and the lower mold 101
The mold is substantially clamped by the weight of the intermediate plate 5 and the upper mold 102, and the injection plate 3 continues to descend further.

When the plunger 4 protruding from the lower surface of the injection plate 3 is inserted into the cylinder part 103 provided in the upper mold 102 through the hole in the intermediate plate 5, the plunger 4 is inserted into the cylinder part 103 by hand in advance. The molding material 200 is plasticized and is about to be press-fitted into the cavity 104. As shown in FIG. 3, the stopper 33 provided on the lower surface of the injection plate 3 comes into contact with the intermediate plate 5 to complete press-fitting, and at the same time, the intermediate plate 5 is further pressed through the biasing member 6. The mold is clamped. At this time, the tip of the knock rod 61 of the biasing member 6 comes into contact with the intermediate plate 5 and is pressed upward, and the spring 62 is compressed.

After injection molding and vulcanization molding are completed, the piston rod 21 is raised. At this time, the biasing member 6 has a spring 62.
A force that urges the intermediate plate 5 downward is generated by the compression force of It is biased in the direction away from 3. Therefore, due to that force, the plunger 4
As the injection plate 3 rises, the cylinder part 10
3, only the injection plate 3 rises, and the intermediate plate 5 remains stopped at that position due to its own weight and the weight of the upper mold 102.

Then, the injection plate 3 rises and its upper surface comes into contact with the locking member 52, the rising force is transmitted to the shaft 51, the intermediate plate 5 also rises, the mold is opened, and the molded body is taken out.

That is, according to the device of this embodiment, since only one hydraulic cylinder 2 is required, the device can be downsized, which is advantageous in terms of installation space and cost. In addition, the plunger 4 is pushed into the cylinder portion 10 by the biasing member 6.
Since the mold is opened after being separated from the injection plate 3, the intermediate plate 5 does not rise together with the injection plate 3, and a problem in which the intermediate plate 5 descends while the injection plate 3 is rising is reliably prevented.

[Brief explanation of drawings]

Figures 1 to 3 relate to an injection molding apparatus according to an embodiment of the present invention; Figure 1 is a schematic front view thereof, Figure 2 is a schematic side view thereof, and Figure 3 is a schematic front view when press-fitting is completed. be. 1... Base body, 2... Cylinder, 3... Injection plate, 4... Plunger, 5... Intermediate plate,
6...Biasing member, 11...Guide rod, 21...Piston, 33...Stopper, 51...Shaft,
52... Locking member, 61... Knock bar, 62...
Spring, 101...Lower mold, 102...Upper mold, 103
...Cylinder part.

Claims (1)

[Claims for Utility Model Registration] Lower stand portion 1a and upper stand portion 1 facing the lower stand portion 1a
b, and has a substantially C-shape in side view, and the lower base portion 1
a base 1 which holds a lower mold 101 on the upper surface of the upper surface of the upper platform 1b and has a driving device 2 fixed to the upper surface of the upper platform 1b; a flat injection plate 3; a plunger 4 provided on the lower surface of the injection plate 3 and protruding downward; a flat intermediate plate 5 disposed below the injection plate 3 so as to be able to come into contact with the injection plate 3; an upper mold 102 having a cylinder portion 103 into which a molding material is placed and into which the plunger 4 is inserted; The through hole 3 is inserted into the through hole 31 provided in the through hole 3.
A locking member 52 provided at a portion protruding upward from 1 restricts the distance of downward movement under its own weight, and is connected to the injection plate 3 so as to move in conjunction with the upward movement of the injection plate 3. A knock rod 61 is inserted into the through hole 32 of the injection plate 3 so as to be movable up and down, protrudes downward, and is locked on the upper surface side of the injection plate 3;
a spring 62 that urges the plunger 4 downward, and provides a force for separating the plunger 4 from the cylinder portion 103 when the mold is opened, and urges the intermediate plate 5 in a direction away from the injection plate 3; 6. An injection molding device characterized by comprising: