JPH0544111Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an injection mold, and more specifically, when opening the injection mold or retracting the injection nozzle, there is a gap between the molded product and the injection nozzle. The present invention relates to an injection mold that can prevent the stringy phenomenon of resin that occurs in the process.

(Prior art) When molding is performed using an injection molding machine, as shown in FIG. The molding cavity 13 is formed in the mold by being brought into contact with the injection nozzle 7 of the injection device 27.
is filled with molten resin.

Such a mold includes a fixed platen 1, a fixed side mounting plate 2,
The fixed side template 3, the movable side template 4, the spacer block 21, and the movable side mounting plate 22 are assembled in this order, and the molding cavity 13 is attached to the fixed side template 3.
and the movable mold plate 4.

Further, the molding cavity 13 is provided with a resin injection passage 8, and the injection nozzle 7 comes into contact with one end of this resin injection passage 8.

After the resin injected into the molding cavity 13 is cooled and solidified, as shown in FIG.
6, the movable platen 23 moves back, and the gap between the stationary mold plate 3 and the movable mold plate 4 opens.

At this time, the molded product 130 that is attached to the movable mold plate 4 and taken out is connected to protruding plates 24 and 25 that are extruded by ejecting pins (not shown) from a product ejecting device of the injection molding machine main body. It is ejected by the molded product ejecting pin 28, and the molded product can be automatically taken out from the injection molding machine.

However, when the mold is opened, the resin filled in the sprue 38 connected to the bottom of the molded product 130, that is, the resin injection passage 8, cools down and
A stringing phenomenon may occur in which the tip of the solidified sprue 38 and the injection nozzle 7 are connected by a filament made of resin.

This stringing phenomenon is caused by the temperature of the mold being kept below the softening point of the resin in order to cool and solidify the molded product, while the injection nozzle 7 is kept at a temperature lower than the softening point of the resin to prevent the nozzle from clogging due to solidification of the resin. This is caused by the temperature being maintained above the melting temperature of the resin. This stringy phenomenon can be avoided by adjusting the mold temperature, nozzle temperature, etc., but depending on the molding material and the shape of the molded product, it is necessary to mold under conditions that cause the stringy phenomenon. You may not get it.

In such a case, the filamentous material generated by the stringing phenomenon may prevent the automatic removal of the molded product 130 from the injection molding machine, or may cause damage to the inside of the molding cavity of the mold or between the stationary template and the movable template. If the mold is closed with thread-like materials remaining on the parting line surface, it may cause poor appearance of the resulting molded product, generation of burrs, or damage to the mold.

Therefore, if filaments are generated during mold opening, it is necessary to completely remove the filaments, which lengthens the molding cycle time and deteriorates molding workability.

In order to improve the deterioration of workability caused by such thread-like materials, Japanese Patent Laid-Open No. 60-67120 proposes a method shown in FIG. 6.

This method involves retracting the injection nozzle 7 in advance before opening the regulation side mold plate 3 and the movable side mold plate 4, and removes the filamentous material generated between the end of the sprue and the injection nozzle 7 from the air nozzle 28. After cooling and solidifying the material by blowing cooling air onto it and cutting it, the mold is opened.

(Problem to be solved by the invention) According to this method, after the filamentous material is cut, the fixed side mold plate 3 and the movable side mold plate 4 are opened to form the molded product 1.
30 is taken out, molded product 1 made of filamentous material
It is possible to avoid situations such as poor ejection of the molded product, poor appearance of the molded product, occurrence of burrs, or damage to the mold.

However, according to the above method, the injection nozzle 7 must be moved backward before the mold is opened, and the molding cycle time for each shot is shorter than when the mold is opened while the injection nozzle is in contact with the mold. Moreover, since the cooling air is also blown onto the injection nozzle 7, the temperature of the injection nozzle fluctuates, making stable molding impossible.

Therefore, the purpose of the present invention is that even if the mold is opened with the injection nozzle in contact with the mold under molding conditions where the stringing phenomenon occurs, the ejection of the molded product will result in thread-like material extending from the molded product in the direction of the injection nozzle. Therefore, it is an object of the present invention to provide an injection molding die that allows stable molding to be performed easily without being hindered.

(Means for Solving the Problem) The inventor of the present invention has proposed that in order to achieve the above object, a cutting plate is provided in the mold for cutting the filamentous material extending from the sprue connected to the molded product in the direction of the injection nozzle when the mold is opened. As a result of considering that it might be advantageous, we arrived at this idea.

That is, the present invention includes a fixed side mounting plate that is attached to the fixed platen side of an injection molding machine and that the injection nozzle comes into contact with, a fixed side mold plate that is provided so as to be openable and closable with respect to the fixed side mounting plate, and a movable platen. An injection mold comprising a movable side mold plate attached to the side,
When the mold is opened, it is located on the side of the resin injection passage that passes through the fixed side mounting plate and the fixed side mold plate and reaches the molding cavity, and when the mold is opened, When the space between the fixed-side mounting plate and the fixed-side mold plate opens, and the sprue formed by cooling and solidifying the molten resin filled in the resin injection passage escapes from the fixed-side mounting plate, the sprue A cutting plate is provided that moves along the fixed side mounting plate from the side of the resin injection passage in a direction across the resin injection passage so as to cut the filamentous material extending from the resin injection nozzle toward the injection nozzle. In the injection mold.

In the present invention having such a configuration, the fact that the cutting plate is passed through the angular pin that runs diagonally within the recess provided in the contact surface of the fixed side template with the fixed side mounting plate allows the cutting plate to be moved. The cutting plate can be easily moved in accordance with the movement of the stationary template without the need for an external power mechanism.

(Function) According to the present invention, there is no need to use cooling air to cool and solidify the filamentous material, so the injection nozzle can be easily maintained at an optimal temperature.

Furthermore, since the cutting plate can reliably cut the filamentous material extending from the sprue that connects to the molded product, the temperature of the injection nozzle can be maintained at the optimum temperature, and stable injection molding can be achieved even under conditions where stringiness occurs. It can be performed.

(Example) The present invention will be explained in more detail using the drawings.

FIG. 1 is a partial sectional view showing an embodiment of the present invention, in which mold A consists of a fixed side mounting plate 2 and a fixed side template 3 attached to a fixed platen 1, and a movable side template attached to a movable platen. 4.

In this mold A, a molding cavity 13 is formed by a fixed side template 3 and a movable side template 4,
A resin injection passage 8 for injecting molten resin into the molding cavity 13 is provided in the stationary mold plate 3 and the stationary mounting plate 2.

In such a mold A, the fixed side mold plate 3 and the movable side mold plate 4 are provided so as to be movable on the guide pins 12.

One end of the pin 9, which is inserted through the counterbore holes 11 and 42 formed in each of the mutually opposing end surfaces of the fixed side template 3, is screwed to the fixed side mounting plate 2, and is provided on the fixed side mounting plate 2 side. A spring 10 is inserted into the counterbore hole 42 and biases the stationary mold plate 3.

In addition, the pin 9 inserted into the countersunk hole 11
A flange is provided at the other end of the fixed side mold plate 3 to restrict the distance the fixed side mold plate 3 can move.

In this mold A, a recess 40 is provided on the contact surface of the fixed side mold plate 3 with the fixed side mounting plate 2, into which a convex portion of the cutting plate 6 is fitted.

This cutting plate 6 is located on the side of the resin injection passage 8, and is passed through the angular pin 5 which runs obliquely inside the recess 40 and whose tip reaches into the recess 41 of the fixed side mounting plate 2. .

As shown in FIG. 2, the cutting plate 6 moves on the angular pin 5 in accordance with the opening and closing of the fixed side template 3, which is provided so as to be openable and closable with respect to the fixed side mounting plate 2.

That is, when the stationary template 3 biased by the spring 10 moves on the guide pin 12 and opens by a distance L with respect to the stationary mounting plate 2, the cutting plate 6 moves away from the stationary template 3. The sprue is moved on the angular pin 5 in a direction substantially perpendicular to the resin injection passage 8, thereby cutting off the filament near the end of the sprue adhering to the molded product while blocking the resin injection passage 8.

As shown in FIGS. 3a and 3b, the cutting plate 6 is a substantially rectangular plate-like body, and has a convex part 61 that fits into the concave part 40 of the movable template 3 and a resin injection passage 8 below the convex part 61. Both sides of the cutting plate 6 are guided by slide guide rails 37 that are fixed to the fixed side mounting plate 2 with bolts 38, and the cutting plate 6 is guided by the slide guide rail 37 that is fixed to the fixed side mounting plate 2 with bolts 38.
It is regulated to move along 7.

In addition, a convex portion 6 provided above the cutting plate 6
1 has a shaft through hole 3 through which the angular pin 5 is passed.
6 is drilled.

3a shows the cutting plate 6 seen from the direction of arrow a in FIG. 2, and FIG. 3b shows the cutting plate 6 seen from the direction of arrow b in FIG. 2.

The moving distance L of the stationary template 3 is the moving distance of the flanged body of the pin 9 in the counterbore hole 11, that is, the distance until the flanged body abuts the bottom surface of the counterbore hole 11.

Movement distance L of fixed side template 3, angular pin 5
The relationship between the inclination angle α and the moving distance H of the cutting plate 6 can be expressed as H=Ltanα. The moving distance L of the stationary template 3 and the inclination angle α of the angular pin 5 are adjusted so that the distance can be achieved.

Next, the operation of the mold according to this example will be described.

As shown in FIG. 1, while the molding cavity 13 is filled with molten resin from the injection nozzle 7 that is in contact with the mold A and is cooled and solidified, the cutting plate 6 is placed on the side of the resin injection passage 8. It is located at a position separated from the resin injection passage 8.

As described above, in the mold according to this embodiment, when the molding cavity 13 is filled with molten resin from the injection nozzle 7, the cutting plate 6 is separated from the resin injection passage 8, so that the resin injection passage 8 The molten resin will not enter in the direction of the cutting plate 6 and cause burrs.

Next, after the resin injected into the molding cavity is cooled and solidified, the injection nozzle 7 is brought into contact with the mold and the mold is opened, as shown in FIG.

First, the fixed side mold plate 3 moves on the guide pin 12 by the biasing force of the spring 10 until the brim of the pin 9 comes into contact with the bottom of the counterbore hole 11, and the distance between it and the fixed side mounting plate 2 increases. Open only L. At this time, the angular pin 5 also moves together with the stationary mold plate 3, and the cutting plate 6 also moves along the stationary mounting plate 2 by a distance H while moving on the angular pin 5, blocking the resin injection passage 8 and molding. Cut the thread near the end of the sprue that is connected to the product.

In this way, first, by opening the space between the fixed side mounting plate 2 and the fixed side mold plate 3 and cutting off the resin injection passage 8 while cutting off the filamentous substance near the end of the sprue, the filamentous substance can be opened from the mold. Since the filament can be cut before it is fully stretched by the progress of the process, cutting is easy.

As the mold opening progresses further, the parting line between the fixed side mold plate 3 and the movable side mold plate 4 opens, and the molded product 130 is removed from the fixed side mold plate 3 while adhering to the movable side mold plate 4, as shown in FIG. 5.

At this time, in the mold of this embodiment, since the thread-like material connected to the sprue 38 is cut in advance before the parting line is opened, the molded product 130 attached to the movable template 4 is In this case, the threads reaching the injection nozzle are not connected, and the molded product 1
30 can be easily dropped from the movable mold plate 4 by the protrusion of the protrusion pin 28.

In addition, the filamentous material falls from the mold together with the molded product 130, and the filamentous material does not remain in the molding cavity of the mold or on the parting line surface, resulting in poor ejection of the molded product, poor appearance of the molded product, Concerns about the occurrence of burrs or damage to the mold due to residual threads on the parting line surface of the mold can be eliminated.

To explain how to clamp the mold opened in this way using FIG. 5, the movable platen 23 is moved in the mold clamping direction on the tie bars by the mold clamping device of the injection molding machine main body. Then, the movable mold plate 4 and the fixed mold plate 3 of the mold come into contact with each other, and the mold plates move on the guide pin 12 while compressing the spring 10 until they come into contact with the fixed mounting plate 2.

Until both of the templates come into contact with the fixed mounting plate 2, the cutting plate 6 moves on the angular pin 5 that moves together with the movable template 3, and the convex part of the cutting plate 6 fits into the concave part 40. At this time, the resin injection passage 8 is opened.

In the present embodiment described above, the cutting plate 6 is moved on the angular pin 5 when the mold is opened, but it may be moved by a cylinder or the like located outside the mold.

Further, although this embodiment has been described with respect to a horizontal injection mold, it can also be sufficiently applied to a vertical injection mold.

Furthermore, even when the injection nozzle is retracted after each shot, by using the mold of the present invention, it is not necessary to cool and cut the filamentous material with cooling air, so the temperature of the injection nozzle can be controlled. Stable molding can be performed without fluctuations.

(Effect of the invention) According to the invention, even in molding under conditions where stringiness occurs, the mold is opened while the injection nozzle is in contact with the mold, and when the molded product is taken out, the molded product is connected in advance. Since the molded product can be taken out after cutting the filament extending from the sprue in the direction of the injection nozzle, the molding cycle time can be shortened compared to the case where the injection nozzle is retracted for each shot.

Furthermore, even during continuous molding, you can perform molding work with peace of mind because you can eliminate concerns about problems such as falling of the molded product due to filamentous objects, occurrence of burrs, or damage to the mold. can.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention;
FIG. 2 is a partial sectional view showing the state in which the cutting plate 6 in FIG. 1 is in operation, and FIG. 3 is an arrow a or arrow b in FIG. 2.
4 is a front view of the mold installed in the injection molding machine, FIG. 5 is an explanatory diagram illustrating the stringing phenomenon when the mold is opened, and FIG. FIG. 6 shows explanatory diagrams each illustrating a conventional method of cutting generated filamentous materials. In the figure, 1... Fixed plate, 2... Fixed side mounting plate, 3... Fixed side template, 4... Movable side template, 5...
... Anguilla pin, 6 ... Cutting plate (blocking plate), 7
... Injection nozzle, 8 ... Resin injection passage, 9 ... Pin, 10 ... Spring, 11, 42 ... Counterbored hole, 12 ... Guide pin, 13 ... Molding cavity, 23 ... Movable platen.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A fixed-side mounting plate that is attached to the fixed platen side of an injection molding machine and to which an injection nozzle abuts, and a fixed-side mold plate that is provided to be openable and closable with respect to the fixed-side mounting plate. , in an injection molding mold comprising a movable mold plate attached to a movable platen side, when the mold is closed, molding passes through the fixed side mounting plate and the fixed side mold plate. It is located on the side of the resin injection passage leading to the mold cavity, and when the mold is opened, the space between the fixed side mounting plate and the fixed side mold plate opens, and the resin injection passage filled with the resin is When the sprue formed by cooling and solidifying the molten resin comes out of the fixed-side mounting plate, the resin injection passage is inserted along the fixed-side mounting plate so as to cut the filamentous material extending from the sprue toward the injection nozzle. A mold for injection molding, characterized in that a cutting plate is provided that moves in a direction across a resin injection passage. 2. The injection molding die according to claim 1, wherein the cutting plate is passed through an angular pin that runs obliquely in a recess provided in the contact surface of the fixed side template with the fixed side mounting plate.