JPH0753399B2 - Product ejection device in injection molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a molded product is removed from the mold, to a projecting equipment products in an injection molding machine.

[0002]

2. Description of the Related Art In an injection molding machine, one or more projecting pins are provided in a mold so as to be movable in the axial direction, and the projecting pins are moved in the axial direction by a projecting driving device such as a cylinder to push a product. , The product is separated from the mold. In this conventional product ejecting device, when a projecting pin having a large diameter (product pressing surface) is used, the projecting drive device for the projecting pin and the entire die become large, and therefore the projecting pin is as thin as possible and has a small product pressing surface. Are using.

[0003]

However, if the product pressing surface of the projecting pin is small, the surface pressure applied to the product becomes large, so that, for example, as in the case of a gear, the external shape is complicated and the mold having a surface parallel to the projecting direction is used. In the case of a product with a large contact area with the mold and a large frictional force against the mold, if the product is not hardened enough and you try to stick it out with a pin, the product may be deformed or damaged. . If the product is made to stick out after it has been sufficiently cured, the above problems will be alleviated, but the molding cycle time will be long and the work efficiency will be reduced.

[0004] The present invention, in a short molding cycle times, without or corrupted deform the product, can be removed from the mold, the product projecting equipment in the structure is simple implementation and easy injection molding machine The purpose is to provide.

[0005]

In order to achieve the above object, the present invention has a hollow chamber and is provided movably in a mold.
The protruding member with a large pressed surface of the product and the mold
The first cylinder chamber formed on the attached moving platen and the protrusion
It has a hollow first piston rod that pushes the lever member at the front end.
A hollow first piston inserted in the first cylinder chamber,
Equipped with one or more protruding pins on the front that have a small product pressing surface
And the axial direction of the above-mentioned protrusion pin of the above-mentioned protrusion member.
Projects movably in those axial directions in line with the moving direction
The inner wall of the rear side of the hollow chamber inserted into the hollow chamber
The rearward movement is regulated by the
Keeps the product pressing surface of the pin protruding against the surface
Of the protruding plate and the first piston rod of the first piston
A second sheet cylinder chamber provided in the rear end portion, the hollow of the first
It is inserted into the piston rod and the first piston, and the protrusion
It is equipped with a second piston rod that pushes the plate at the front end.
The second piston inserted in the binder chamber and the first cylinder
The first chamber is installed on the pipe connecting the chamber to the hydraulic pump.
The first solenoid control valve for controlling the operation of the
Installed in the piping that connects the Linda chamber to the hydraulic pump
A second electromagnetic switching valve for controlling the operation of the two pistons,
It has a different configuration.

[0006]

[Function] The first pre-projection uses two electromagnetic switching valves at the same time.
And the first piston and the second piston are moved forward.
By doing so, the projecting member and the projecting pin are moved together with the mold to push the product against a wide and large product pressing surface, so that the product adheres to the mold and is deformed or damaged even if the frictional force is increased. There is nothing to do. Subsequent to the pre-projection , the projecting pin is moved by the switching of the second electromagnetic switching valve to move the projecting pin with respect to the projecting member by the second piston to perform the main projecting, and the product is released from the mold. In this case, the pre-projection reduces the frictional force between the mold and the product, and the hardening of the product progresses over time, so even if the product pressing surface of the projecting pin is small, the product will not be deformed or damaged. To be done.

Since the diameter of the projecting member is large, but the stroke of the preliminary projecting is small, it is possible to prevent the first cylinder chamber and the like and the entire die from becoming large.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention applied to an injection compression molding machine, in which reference numeral 1 is a fixed platen. A tie rod 2 is attached to the fixed platen 1 and slidably supports a movable platen 3. Molds 4 and 5 are attached to the stationary platen 1 and the movable platen 3. The mold 5 has a compression core (projecting member) 6. Cylinder chamber 3 on the moving board 3
a is formed, and a piston 8 having a piston rod 7 is inserted into the cylinder chamber 3a. The cylinder chamber 3a, the piston 8 and the like constitute a cylinder device 9 that moves the compression core 6. The piston rod 7 has its front end (in FIG. 1)
The right end ) is joined to the compression core 6 by bolts or the like (not shown). The cylinder device 9 is the cylinder
Are connected by a pipe to the chamber 3a to a hydraulic pump (not shown), said
The operation is controlled by the electromagnetic switching valve 10 provided in the pipe .

Reference numeral 11 is an injection device, which is a nozzle 1.
Molten resin from 2 is injected into the cavities of the molds 4 and 5 through the sprue 4a. The resin injected into the cavity is finally compressed by the action of the compression core 6 by the cylinder device 9 and hardened as it is to become a product. The basic structure of the above injection compression molding machine is well known.

A hollow chamber 6a is formed in the compression core 6, and a projecting plate 15 in which a plurality of projecting pins 14 are planted is inserted into the hollow chamber 6a. Each protruding pin 14
Has its axial direction aligned with the moving direction of the compression core 6 and is fitted into the compression core 6 so as to be movable along with the axially protruding plate 15. The protruding plate 15 has a rear surface (left side in FIG. 1).
The inner surface of the hollow chamber 6a against the inner wall on the rear side,
With the movement stopped, the product pressing surface of the projecting pin 14
Is aligned with the product pressing surface of the compression core 6 as shown in the figure.
Has become.

The piston rod 7 and the piston 8 are formed hollow, and the rear end portion of the piston rod 7 (the left end portion in the figure )
Is provided with a cylinder chamber 7a. A piston 17 having a piston rod 16 is inserted in the cylinder chamber 7a. The piston rod 16 of the other piston rod 7
It is fitted to the piston 8 are coupled to the front end to the convex portion 15a of the ejector plate 15. Cylinder device 1 in which cylinder chamber 7a, piston rod 16 and the like project to move pin 14
8 and the two cylinder devices 9 and 18 form a projecting drive device. Cylinder device 18, the sheet
Are connected Linda chamber 7a by a pipe to the hydraulic pump, the
The operation is controlled by an electromagnetic switching valve 19 provided in the pipe .

The cylinder device 9 has a pulse encoder (not shown) for detecting the position of the compression core 6, and the other cylinder device 18 has a pulse encoder (not shown) for detecting the position of the protruding pin 14. Each is attached, and each position is displayed on the display. The forward limit position and the backward limit position of each cylinder device 9 and 18 are set by operating a keyboard (not shown) and displayed on the display.

Next, a method of projecting a product in the injection molding machine configured as described above will be described with reference to the flowchart of FIG. When the molding cycle is started, the mold is first closed, and the nozzle 12 advances when the mold is completely closed. When the advance of the nozzle 12 is completed, the injection is started, and the cylinder device 9 operates at the same time as the start of the injection or when the filling is completed, and the compression core 6 is compressed and advanced to a predetermined position. This
At this time, the projecting pin 14 projects the force of the compression core 6 and projects the plate 15.
Then, it moves forward together with the compression core 6.

When the injection is completed after the lapse of the time set by the injection timer, the cooling process starts, the resin is measured in the injection device 11, and the nozzle 12 retracts. When the time set by the cooling timer has elapsed, the compression core 6 retracts or stops, and the injection compression process ends. Then type opening is Ru is carried out.

After the mold opening is completed, the cylinder device 9 is actuated again, and the compression core 6 is advanced to the forward limit to preliminarily project the product. At this time, the projecting pin 14 moves together with the compression core 6 with respect to the mold 5. Then, when the time set in the compression advance timer elapses, the cylinder device 18 is activated this time, and the ejection pin 14 is moved to the set advance position with respect to the compression core 6 to perform the main ejection of the product, Separate from the mold 5. Finally, the cylinder device 18 causes the projecting pin 14 to retract to the retracted limit, and the cylinder device 9
Then, the compression core 6 is returned to the backward limit and one molding cycle is completed.

Reference numeral 20 is a spring, which biases the protruding plate 15 in the returning direction. This spring 20 projects the pin 14
Can be moved back, and in such a case, the rod side port of the cylinder chamber 7a can be omitted.

Although the cylinder chamber 3a in FIG. 1 is formed directly on the movable platen 3, the member forming the cylinder chamber is replaced by the movable platen 3a.
It can also be carried out by attaching to. Further, the present invention can be applied not only to the injection compression molding machine having the compression core 6 but also to a general injection molding machine having no compression core 6. In this case, in the example of FIG. 1, the compression core 6 does not compress the resin, but functions as a projecting member and only pre-projects the product.

[0018]

As described above, the present invention provides a hollow chamber.
Has a large product pressing surface that is provided in the mold
Formed on the moving plate with the protruding member and the mold attached.
The first cylinder chamber and the hollow that pushes the protruding member at the front end
Equipped with the first piston rod, and inserted into the first cylinder chamber
Hollow first piston and one small product pressing surface
The above-mentioned protruding pin is provided on the front surface and
Align the axial direction of the projection with the moving direction of the protruding member.
Inserted in the hollow chamber of the protruding member so that it can move in the axial direction.
The inner wall on the rear side of the hollow chamber regulates the backward movement.
Of the protruding pin against the product pressing surface of the protruding member.
The protruding plate that keeps the product pressing surface in a predetermined state, and the first pin
Second on the rear end of the first piston rod of Ston
The cylinder chamber, the hollow first piston rod and the first piston.
Second pis that is inserted into the stone and pushes the protruding plate at the front end
Ton rod, which is inserted into the second cylinder chamber.
Connect two pistons and the first cylinder chamber to a hydraulic pump
Is installed in the pipe to control the operation of the first piston.
The first electromagnetic switching valve and the second cylinder chamber are used as hydraulic pumps.
It is provided in the connected pipe and controls the operation of the second piston.
Since it is configured to include the second electromagnetic switching valve , the following effects can be obtained.

(1) It is possible to prevent deformation and damage of the product due to excessive surface pressure when the product is projected.

(2) At the time of protrusion, even if the product strength is small, no damage or the like occurs. Therefore, the long cooling time required to completely cure the product is not necessary, and the molding cycle time can be shortened. (3) When the resin is injected into the mold cavity to the extent that it is overfilled and the shrinkage of the product due to curing is to be canceled out, the frictional force increases due to overfilling and it is easy to take out the product. According to this, the product can be taken out smoothly without damaging it.

(4) Use a protruding member with a large product pressing surface.
While the moving cylinder device requires a strong force, it does not
Roke can be short, but small protrusions on the product pressing surface
Cylinder device that moves the output pin does not require strong force
However, it usually requires a long stroke and the functions are in conflict with each other.
Is required. However, in the present invention, moving the protruding member
A small-diameter cylinder that moves a protruding pin to a large-diameter cylinder device.
And the small diameter cylinder device is installed concentrically.
After pre-projection by the large diameter cylinder device, its position
In this case, it is configured to operate independently to perform the main protrusion.
Therefore, the required functions described above are reasonably and sufficiently satisfied.
Therefore, it is not necessary to increase the wall thickness of the moving board and the mold.
In addition, it is possible to prevent the size of the entire mold apparatus from increasing.

(5) Cylinder device for moving the protruding member
The relationship between the hollow piston and piston rod is
Although the structure of the cylinder device of the
To install a cylinder device for
Since no special processing is required, the strength of the moving board is impaired.
Without it, the overall structure is simple. In addition,
The delivery timing can be set arbitrarily, and maintenance is easy.
Besides being easy, it has the advantage of being simple in structure and easy to implement.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a product projecting device in an injection molding machine of the present invention applied to an injection compression molding machine.

FIG. 2 is a flow chart of the product ejecting apparatus of FIG.

[Explanation of symbols]

 4, 5 Mold 6 Compression core (projection member) 9, 18 Cylinder device (projection drive device) 14 Projection pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 59-79324 (JP, U) Rikai 62-189118 (JP, U) Rikai 58-104624 (JP, U) Japanese Patent Sho 60- 23969 (JP, B2) JP 62-16213 (JP, B2) JP 62-17219 (JP, Y2)

Claims (1)

[Claims] 1. A hollow chamber (6a) having a hollow chamber (6a) is moved to a mold (5).
A projecting member (6) with a large product pressing surface that is freely provided
And the movable platen (3) with the mold (5) attached.
First cylinder chamber (3a) and the protruding member (6)
Is equipped with a hollow first piston rod (7) that pushes the
Hollow first piston inserted in the first cylinder chamber (3a)
Ton (8) and one or more protruding pins with a small product pressing surface.
(14) on the front side and the protruding pin (1
The axial direction of 4) matches the moving direction of the protruding member (6).
Of the protruding member (6) so as to be movable in the axial direction thereof.
After the hollow chamber (6a) is inserted into the hollow chamber (6a),
The inner wall on the side limits the rearward movement of the protruding member.
Product with protruding pin (14) against product pressing surface of (6)
A protruding plate (15) for keeping the pressing surface in a predetermined state;
Rear end of first piston rod (7) of one piston (8)
The second cylinder chamber (7a) provided in the
Inserted into the 1 piston rod (7) and the 1st piston (8)
The second piston rod that pushes the protruding plate (15) at the front end
Equipped with a pad (16) and inserted into the second cylinder chamber (7a).
The inserted second piston (17) and the first cylinder chamber
(3a) is provided in the pipe connected to the hydraulic pump, and
A first solenoid operated directional control valve (1) for controlling the operation of one piston (8).
0) and the second cylinder chamber (7a) to the hydraulic pump.
Operation of the second piston (17) provided in the continuous pipe
And a second electromagnetic switching valve (19) for controlling the
Product ejection device in the characteristic injection molding machine.