JPH0919951A - Injection molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To thoroughly clean a groove-like gas vent on the parting faces of molds. SOLUTION: A brush 41 is provided on a vertically movable arm 32 of a take-out device 31. When the arm 32 enters the gap between a stationary mold 12 and a movable mold 14, the brush 41 wipes and cleans the stationary mold 12. All the groove-like gas vents formed on the parting face 12a of the stationary mold 12 which face abuts against the movable mold 14, extend linearly in vertical directions agreeing with the moving directions of the brush 41. Thus it is ensured that the brush 41 will not be caught by a side face of a gas vent but will remove from the gas vents dust such as resin residue.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine, and more particularly to an injection molding machine equipped with a cleaner.

[0002]

2. Description of the Related Art For example, in injection molding of a thermoplastic resin, a fixed mold and a movable mold of a mold are closed to form a product-shaped cavity between the fixed mold and the movable mold, and the cavity is heated. After filling the melted thermoplastic resin,
This resin is cooled and solidified to form a product. When filling the resin in the cavity, air and resin gas must be released from the cavity.
A shallow concave groove-shaped gas vent extending from the cavity to the outside air is formed on the abutting surfaces of the fixed die and the movable die. Conventionally,
This gas vent is normally provided radially to the cavity. This is based on the design principle that the gas vent should be as short as possible and that it should be installed in a place where gas can easily accumulate.

As described above, resin gas is generated during molding, but this gas pollutes the mold. This dirt is highly viscous and adheres to the mold. It should be noted that the abutting surfaces of the fixed die and the movable die, including the gas vent, are more easily soiled than the product forming surface of the die for forming the product. Further, when the contamination by the gas progresses, the filling balance of the resin may be deteriorated, or defective molding such as burning or warping may occur. Therefore, it is necessary to stop the molding and clean the mold from time to time in order to remove the dirt of the resin due to the gas.

Conventionally, this cleaning is performed manually by using a rag or a brush or a whetstone. Therefore, it is labor intensive and, at that time, the molding must be stopped, which deteriorates the productivity.
Particularly, when attempting to automate and unmanner the entire molding process, cleaning the mold is a major obstacle.

On the other hand, in automation, such as a resin sealing device for an IC, after the transfer molding of the resin sealing part, the resin sealing part is cleaned by a cleaner equipped with a brush and an air blow device. Automatic cleaning of molding dies is also performed. However, if these cleaning steps are separately incorporated, the molding cycle becomes long.

Further, in the conventional resin sealing device, the moving direction of the brush and the directivity of the gas vent are not particularly associated with each other, and some gas vents have a directivity intersecting with the moving direction of the brush. However, if the moving direction of the brush and the direction of the gas vent intersect, dusts such as resin slag are easily caught on the side surface of the gas vent and remain on the gas vent during cleaning with the brush.

[0007]

As described above, in the conventional injection molding, the cleaning of the mold is carried out manually after the molding is stopped, so that the efficiency is poor and the productivity is deteriorated. was there. Further, some ICs have a cleaner such as a brush that automatically cleans a mold, such as a resin sealing device. However, conventionally, the moving direction of the brush and the direction of the gas vent are particularly associated with each other. Therefore, in the gas vent having a direction intersecting with the moving direction of the brush, there is a problem that dust such as resin slag tends to remain even after cleaning with the brush.

The present invention is intended to solve such a problem, and the mold can be cleaned efficiently, and
An object of the present invention is to provide an injection molding device that can cleanly clean a groove-shaped gas vent on a divided surface of a mold.

[0009]

In order to achieve the above object, the injection molding apparatus of the present invention has a plurality of mold bodies which are opened and closed to form a product-shaped cavity between them when the molds are closed. And a cleaner having a cleaning body that is inserted between these mold bodies that have been opened so as to be able to be inserted into and removed from the mold bodies and that sweeps the dividing surfaces of the mold bodies, and the mold body has a groove-shaped gas vent that connects the cavity to the outside of the mold body. The gas vents of the divided surface which are provided on the divided surface and swept by the cleaning body are all provided in the same direction as the moving direction of the cleaning body.

According to a second aspect of the present invention, in the injection molding apparatus according to the first aspect of the present invention, the gas vent communicating with the side surface along the moving direction of the cleaning body in the cavity on the dividing surface swept by the cleaning body is the above-mentioned. It is provided across the dividing surface along the lateral surface.

[0011]

According to the injection molding apparatus of the first aspect of the present invention,
A plurality of mold bodies are closed and resin is filled in the cavity formed between these mold bodies. At this time, air or resin gas is discharged from the inside of the cavity through the gas vent. After the resin filled in the cavity is solidified, the mold is opened to take out the solidified resin in the cavity, that is, the molded product. Also, when the molds are opened, a cleaner is inserted between these molds and then comes out again. Along with the movement of the cleaner, the cleaning body sweeps the divided surfaces of the molds and cleans the divided surfaces. The gas vent is a portion where dirt due to the gas of the resin is likely to adhere and accumulate, but the groove-like gas vents of the divided surface swept by the cleaning body are all in the same direction as the moving direction of the cleaning body, The cleaning body is not caught on the side surface of the groove-shaped gas vent, and dust such as resin slag is reliably removed from the gas vent.

Further, in the injection molding apparatus according to the second aspect of the present invention, when the cavity is filled with resin, the side surface of the cavity along the moving direction of the cleaning body is divided along the side surface with the dividing surface of the mold body. The gas in the cavity and the gas of the resin flow out through the gas vent provided across. At the time of cleaning with a cleaner, the cavities along the lateral surfaces of the cavities also have the same directionality as the moving direction of the cleaning body, so that dust such as resin slag can be reliably removed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the injection molding apparatus of the present invention will be described below with reference to the drawings. In the drawing,
1 is a fixed side platen of the injection molding machine, 2 is the same movable side platen, 3 is the same tie bar, and the movable side platen 2 moves back and forth along the tie bar 3. The molding die is a fixed die 12 which is a die body attached to the fixed side platen 1 via a fixed side attachment plate 11, and a die body attached to the movable side platen 2 via a movable side attachment plate 13. It consists of the movable type 14 which is. These fixed type 12
The movable mold 14 is opened and closed with the movement of the movable platen 2 to form four cavities in the shape of the product P when the mold is closed. in this way,
The mold of this embodiment has four dies, but the number of dies is not limited to that. It should be noted that 12a and 14a indicate mutual dividing surfaces (parting line surfaces) of the fixed die 12 and the movable die 14, and 12b and 14b indicate product forming surfaces that form cavities among them.

A plurality of shallow concave groove-shaped gas vents 16 and 17 for communicating the cavity to the outside air outside the mold are formed on the surface of the fixed surface 12a of the fixed mold 12 that abuts the movable mold 14. These gas vents 16 and 17 are all linear in the vertical direction. In addition, an air passage 18 is provided in the fixed mold 12.
Is formed, and the tip of the air passage 18 opens to the gas vents 16 and 17 as an air outlet 19. The other end of the air passage 18 has a connecting portion 20 provided on the side surface of the fixed mold 12.
And an air supply source (not shown) is connected to the connection portion 20. Although the air passage 18 is thin, many air vents 19 of the gas vents 16 and 17 are provided so that the air can be blown out sufficiently strongly from the air blowout port 19.
Is divided into several groups, and an air passage 18 of a different system is provided for each group. On the other hand, the dividing surface 14a of the movable mold 14
The gas vent is not formed as much as possible. That is, preferably, no gas vent is formed on the dividing surface 14a of the movable mold 14.

Although not shown, the fixed mold 12 is provided with sprues and runners for allowing the resin injected from the nozzle of the injection molding machine to flow into each cavity. On the other hand, in the movable mold 14, an ejection plate 22 to which an ejection pin 21 for ejecting the molded product P is fixed.
Is movably provided in the front and back. This protruding plate 22 is
It is pushed and driven by an ejection rod 23 provided on the injection molding machine side.

Denoted at 31 is a take-out device comprising a robot or the like for automatically taking out the molded product P from the mold. The take-out device 31 moves vertically to open the fixed mold 12.
And an arm 32 which is inserted between the movable molds 14 so as to be insertable and removable. At the lower end of the arm 32, a vacuum pad 34 that is rotationally driven around a support shaft 33 in the left-right direction.
The vacuum pad 34 is provided with a plurality of suction elements 35 for vacuum-sucking the product P. These suction elements 35 are movable in the thickness direction of the vacuum pad 34.

The take-out device 31 also serves as a cleaner, and the arm 32 is fixed to the fixed mold 12 side as the arm 32 is inserted into and removed from the fixed mold 12 and the movable mold 14. A brush 41 is provided as a cleaning body for sweeping and cleaning the divided surface 12a of the die 12 with the movable die 14. This brush 41 includes a brush base 42 supported by an arm 32.
It was planted in. And, as mentioned above, the fixed type
The gap between the fixed die 12 and the movable die 14 when the die is opened is set so that the brush 41 sweeps the 12 divided surfaces 12a with an appropriate force. Further, the brush 41 is adjustable with respect to the arm 32 in the front-back direction, that is, the position in the direction in which the fixed die 12 is suppressed from the divided surface 12a. Then, by moving the brush 41 in the front-back direction, it is possible to adjust the degree of hanging of the brush 41 on the divided surface 12a. Further, the length of the brush 41 in the left-right direction is equal to or longer than the length of the divided surface 12a in the left-right direction so that the entire divided surface 12a of the fixed die 12 can be swept. Further, the vertical movement (stroke) of the brush 41, that is, the vertical movement of the arm 32 can be changed.
The timing can be selected between the case where the vacuum pad 34 captures the product P when the arm 32 descends and the case where the vacuum pad 34 captures the product P when the arm 32 ascends.

Next, the operation of the above configuration will be described. At the time of molding, as shown in FIG. 1, with the fixed mold 12 and the movable mold 14 closed, the thermoplastic resin melted by heating is heated in the cavity formed between the fixed mold 12 and the movable mold 14. Fill. At this time, gas of air and resin flows out from the inside of the cavity through the gas vents 16 and 17. After the resin filled in the cavity is cooled and solidified, as shown in FIG. 2 and FIG.
14 and the mold are opened. With this mold opening, the resin in the cavity, that is, the molded product P, first separates from the fixed mold 12 due to the difference in the mold release resistance. Then stick out rod
When the pushing plate 23 is pushed by 23, the pushing plate 22 moves relatively to the movable die 14 toward the fixed die 12, and accordingly, the pushing pin 21 pushes out the product P to move the die 14.
Release from.

When the fixed mold 12 and the movable mold 14 are opened as described above, the arm 32 of the take-out device 31 descends and enters between the fixed mold 12 and the movable mold 14. At this time, the vacuum pad 34 stands vertically and faces the movable mold 14. Then, as described above, the product P ejected by the ejecting pin 21 is pressed against the vacuum pad 34. here,
As shown in FIG. 2, the suction element 35 holds the product P by vacuum suction. Then, with the vacuum pad 34 holding the product P, the arm 32 of the take-out device 31 rises and comes out from between the fixed die 12 and the movable die 14. The product P taken out from the mold in this manner is further conveyed by the take-out device 31 to a product accommodating portion (not shown) and accommodated therein.

After the product P is taken out in this way, the mold is closed again and the molding is repeated. That is, the above series of steps is regarded as one cycle, and this is sequentially repeated.

By the way, during molding, a gas of resin is generated, but this gas condenses and adheres to the mold, thus contaminating the mold. This dirt is the split surface of the fixed mold 12 and the movable mold 14.
12a, 14a, especially near the gas vents 16, 17 are likely to occur.
On the other hand, as described above, the arm 32 of the take-out device 31
When the brush moves up and down to enter between the fixed mold 12 and the movable mold 14 and to come out again, the brush 41 provided on the arm 32 moves the fixed mold 12
Sweep and clean the split surface 12a. At this time, this division plane
To clean 12a from top to bottom, as shown in Fig. 3,
The arm 32 descends further below the position when the product P is received from the movable mold 14. The product P can be received when the arm 32 descends, or can be received when the arm 32 rises. However, when the vacuum pad 34 receives the product P from the movable mold 14,
The arm 32 stops once.

It should be noted that the brush 41 sweeps the abutment surface of the split surface 12a against the movable die 14 and does not sweep the product forming surface 12b, but it is difficult for gas condensate to adhere to the product forming surface 12b as well as the problem. Absent. Conversely, if the brush 41 is forcibly inserted up to the product forming surface 12b, the brush bristles may be broken by the edge portion of the product forming surface 12b and may remain in the mold.

In addition to the cleaning with the brush 41,
The air supplied to the air passage 18 is blown from the air blowing port 19 to the gas vents 16 and 17, and dusts such as resin slag are scattered and removed from the dividing surface 12a of the fixed mold 12 including the gas vents 16 and 17. . The air can be blown from the air blowing port 19 until just before the resin is injected into the cavity. Further, by passing the air through the air passage 18, the cooling efficiency of the mold can be improved.

As described above, according to the configuration of the above-described embodiment, the brush 41 is provided in the device 31 for taking out the product P, so that the mold can be automatically cleaned during the molding cycle, and the product P can be cleaned. Since it can be cleaned at the same time as the taking-out process, it is efficient and can improve productivity. Further, since the mold can be automatically cleaned, it becomes possible to cope with automation of the entire molding process. Moreover, since the cleaning is performed during each molding cycle, the mold can be kept clean.

Further, while the arm 32 of the take-out device 31 provided with the brush 41 moves linearly in the vertical direction, all the air vents 16 and 17 have the same linear shape in the vertical direction. The brush 41 can sweep the air vents 16 and 17 over the whole smoothly without being caught on the side surfaces of the air vents 16 and 17. Therefore, the air vents 16 and 17 can be cleaned cleanly,
It is possible to prevent dust such as resin slag from accumulating in 17.

The brush 41 cleans only the fixed mold 12, not the movable mold 14, but the gas vents 16 and 17 are fixed as much as possible.
Since it is provided on 12 and not on the movable mold 14,
Dirt on the movable mold 14 side is less of a problem than on the fixed mold 12. That is, since more gas vents 16 and 17 are provided in the fixed mold 12 than in the movable mold 14, effective cleaning can be achieved by cleaning only the fixed mold 12.

When the arm 32 of the take-out device 31 is movable in the mold opening / closing direction, the brush 41 may sweep the fixed mold 12 only when the arm 32 descends or when it rises. Particularly in this case, the relationship between the timing when the brush 41 sweeps the fixed die 12 and the timing when the vacuum pad 34 holds the product P can be set arbitrarily.

Next, a second embodiment of the injection molding apparatus of the present invention will be described with reference to FIG. In the following description, the same parts as those in the first embodiment will be designated by the same reference numerals, and the description thereof will be omitted. The same applies to the third and subsequent embodiments described later. In the second embodiment, the split surface 12a of the fixed mold 12 swept by the brush 41 is formed with a groove-shaped gas vent 51 communicating with the lateral surface on the left or right side of the cavity, that is, the lateral surface along the moving direction of the brush 41. It is a thing. These gas vents 51 are linear in the vertical direction, which is also the moving direction of the brush 41, and cross the dividing surface 12a from the top to the bottom along the lateral surface of the cavity. The gas vents 51 are also provided with air outlets 19 communicating with the air passages 18.

At the time of molding, as the resin is filled in the cavity, in addition to the gas vents 16 and 17 above and below the cavity, the gas vent 51 on the left side or the right side of the cavity is also passed through to allow the air and resin inside the cavity to pass through. Gas goes out of the mold.

As described above, when it is desired to provide the gas vent 51 communicating with the lateral surface along the moving direction of the brush 41 in the cavity in the dividing surface 12a swept by the brush 41, the dividing surface 12a is traversed along the lateral surface. The gas vent 51 may be provided. Thereby, even in the gas vent 51 communicating with the side surface of the cavity, since the gas vent 51 has the same directionality as the moving direction of the brush 41,
With this brush 41, dust such as resin slag can be reliably removed, and cleaning can be performed cleanly.

Although the brush 41 is moved in the vertical direction in both of the above-mentioned embodiments, the brush may be moved in the left-right direction or in another direction to move in and out between the fixed mold and the movable mold. . Further, the movement of the brush is not limited to linear movement, and may be curvilinear movement as in the third embodiment shown in FIG. In the injection molding apparatus of the third embodiment, the brush 56, which is the cleaning body of the cleaner 55, makes a circular motion around a rotation axis (not shown) in the front-rear direction outside the mold. On the other hand, the dividing surface 12 of the fixed die 12 swept by the brush 56
The groove-shaped gas vents 57 and 58 formed in a are formed in an arc shape centering on the rotation axis. That is, the directions of the gas vents 57 and 58 are the same as the moving direction of the brush 56.

As described above, even when the brush 56 does not move linearly, by forming the gas vents 57 and 58 in a curved shape in conformity with the moving direction of the brush 56, the brush 56 can have side faces. It is possible to reliably remove dusts such as resin slag from the gas vents 57 and 58 without being caught on.

FIG. 7 shows a fourth embodiment of the injection molding apparatus of the present invention. In the fourth embodiment, the arm 32 of the take-out device 31 in the first or second embodiment is used.
In addition to the brush 41, an air nozzle 61 for blowing out air is added. Then, when the molded product P is taken out, the brush 41 sweeps the dividing surface 12a of the fixed die 12, and air is blown from the air nozzle 61 to the dividing surface 12a of the fixed die 12, so that the resin residue on the dividing surface 12a is blown. Are blown away and removed. By thus providing the air nozzle 61 in addition to the brush 41, cleaning can be performed more effectively.

Besides, the present invention can be variously modified. For example, the cleaning body is not limited to the brushes 41 and 56.
Further, in the first and second embodiments, the take-out device 31 and the cleaner are combined, but the take-out device and the cleaner may be separate. In fact, in the third embodiment, it is assumed that the take-out device and the cleaner are separately provided. When the take-out device and the cleaner are separately provided, cleaning may be continuously performed when the mold is opened, for example, after taking out the product by the take-out device. When the take-out device and the cleaner are separately provided, not only the fixed type but also the movable type can be cleaned by the cleaner.

[0035]

According to the first aspect of the present invention, there is provided a cleaner having a cleaning body which is removably inserted between the opened mold bodies and sweeps the division surface between the mold bodies, and the division surface swept by the cleaning body. Since all the grooved gas vents are provided in the same direction as the moving direction of the cleaning body, the mold can be cleaned efficiently and the grooved gas vents on the divided surfaces can be cleaned cleanly.

When it is desired to provide a gas vent on the divided surface swept by the cleaning body, the gas vent communicating with the side surface along the moving direction of the cleaning body in the cavity, as in the invention of claim 2, It is sufficient to provide a gas vent across the dividing surface so that the gas vent leading to the side surface can be cleaned cleanly.

[Brief description of the drawings]

FIG. 1 is a partially sectional side view showing a first embodiment of an injection molding apparatus of the present invention, showing a state when a mold is closed.

FIG. 2 is a side view in which a part of the same is shown in section, showing the state when the mold is opened.

FIG. 3 is a side view in which a part of the same is shown in section, showing a state when the mold is opened.

4A and 4B show the same fixed type, wherein FIG. 4A is a front view and FIG. 4B is a sectional view taken along line bb of FIG.

FIG. 5 is a front view of a fixed mold showing a second embodiment of the injection molding apparatus of the present invention.

FIG. 6 is a front view of a fixed mold showing a third embodiment of the injection molding apparatus of the present invention.

FIG. 7 is a partial cross-sectional side view showing a fourth embodiment of the injection molding apparatus of the present invention.

[Explanation of symbols]

 12 Fixed type (mold body) 12a Dividing surface swept by the cleaning body 14 Movable type (mold body) 16, 17 Gas vent 31 Extraction device (cleaner) 41 Brush (cleaning body) 51 Gas vent 55 leading to the side surface of the cavity 55 Cleaner 56 Brush (Cleaning body) 57, 58 Gas vent

Claims (2)

[Claims] 1. A plurality of molds which are opened and closed to form product-shaped cavities between them when the molds are closed, and a cleaning which is removably inserted between the opened molds and sweeps a dividing surface between the molds. A cleaner having a body, the mold body has a concave groove-shaped gas vent for communicating the cavity to the outside of the mold body, and all the gas vents of the division surface swept by the cleaning body are the cleaning body. An injection molding device, which is provided in the same direction as the moving direction of. 2. A gas vent, which is located on a divisional surface swept by the cleaning body and communicates with a side surface of the cavity along the moving direction of the cleaning body, is provided across the divisional surface along the side surface. The injection molding apparatus according to claim 1.