JP2008044214A - Mold release method of molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold release method of a molded product capable of efficiently and well releasing a molded product by controlling cracking width small with high precision. <P>SOLUTION: The mold release method of the molded product includes a first process for introducing compressed air to the steam chamber 32 of a fixed mold 3 while forming a mold release cracking width W, which is 3-30% of the height of the molding, between the fixed mold 3 and a movable mold 4 by positively rotating a ball screw 6 to release the molding from the fixed mold 3, a second process for performing mold clamping up to a mold clamping limit or the midway of the mold clamping limit by forwardly/reversely rotating the ball screw and a third process for introducing compressed air into the steam chamber 42 of the movable mold 4 to remove a molding from the removable mold while forming a mold release cracking width W, which is 3-30% of the height of the molding between the fixed mold and the movable mold by positively rotating the ball screw. Further, a fourth process for again performing mold clamping after the third process is added and the operation returned to the first process is repeated a plurality of times after the fourth process is performed to repeatedly apply high pressure to the interface of the molding. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for releasing a molded product for removing the molded product from a mold.

  As a foam molding machine, for example, a hydraulic cylinder system disclosed in Patent Documents 1 and 2 is known. The foam molding method using the foam molding machine of such a system is as follows: (1) A mold is clamped to form a cavity, and a raw material bead filling step of filling a raw material bead such as polystyrene in the cavity; 2) Heating step of heating the raw material beads with heating steam to melt and foam, (3) Cooling step of cooling and solidifying the foam, and (4) Opening the mold after cooling to form a molded product having a predetermined shape. A mold release step to remove from the mold. Mold release refers to introducing compressed air into a contact surface between a mold and a molded product (hereinafter referred to as a molded product interface) to pull the molded product away from the mold.

  For example, as shown in Patent Document 3, the mold includes a fixed mold that is a concave mold and a movable mold that is a convex mold. The fixed type and the movable type have a vapor chamber inside, and a vent hole for the core vent is provided on the surface constituting the cavity. The fixed mold is provided with a raw material supply machine and an eject pin which are not shown.

  When a molded product is taken out in the mold release process, a mold cracking width (hereinafter referred to as mold release crack width) is formed between the fixed mold and the movable mold, and then the molded product is floated from the mold. The compressed air was sent from the steam chamber through the vent hole to the molded product interface. However, in the hydraulic cylinder type foam molding machine, the setting accuracy of the cracking width is inferior, and the cracking width fluctuates widely by blowing compressed air, so the height of the molded product (the thickness of the molded product with respect to the mold opening / closing direction) ), It was necessary to set a large release cracking width of more than 30% to 50%.

However, such a large mold release cracking width makes it easy for the compressed air to escape, making it difficult to apply a high pressure to the interface of the molded product, resulting in the occurrence of mold release defects and waste of compressed air. . If the mold release is insufficient, the molded product will be deformed, broken, or pierced by the eject pin.
Therefore, development of a technique capable of efficiently and satisfactorily releasing a molded product with compressed air by controlling the mold release cracking width with a small and high accuracy has been awaited.
JP-A-5-154930 (FIG. 1) JP-A-6-182888 (FIG. 1) Japanese Patent Laid-Open No. 10-180884 (FIG. 2)

  In view of the above-described conventional problems, the present invention provides a mold release method capable of efficiently and satisfactorily releasing a molded article by controlling the mold release cracking width to be small and highly accurate. This is the issue.

The mold release method of the present invention made to solve the above problem is a mold release method in a foam molding machine that is clamped and opened by forward rotation and reverse rotation of a ball screw,
After molding the molded product, the ball screw is reversed to form a release cracking width of 3 to 30% of the molded product height between the fixed mold and the movable mold, and compressed air is introduced into the movable steam chamber Then, after the molded product is released from the movable mold and deposited in the fixed mold, the molded product is released from the fixed mold. In this specification, forward rotation of the ball screw refers to rotation in a direction in which the movable mold is clamped, and reverse rotation of the ball screw refers to rotation in a direction in which the movable mold is opened.

  In the above-described invention, the movable mold is moved at a predetermined pitch to open the mold stepwise up to the mold release cracking width, and compressed air can be introduced into the movable steam chamber for each movable movement.

  In addition, the movable mold opening is performed while reducing the speed to the mold release cracking width, and the compressed air can be continuously introduced into the movable steam chamber.

Further, the mold release method of the present invention is a mold release method in a foam molding machine that is clamped and opened by normal rotation and reverse rotation of a ball screw, and after molding the molded product,
Reversing the ball screw to form a release cracking width of 3 to 30% of the molded product height between the fixed mold and movable mold, and fixing the molded product by introducing compressed air into the steam chamber of the fixed mold A first step of releasing from the mold and depositing in the movable mold;
A second step of rotating the ball screw forward to clamp the mold to the mold clamping limit or to the mold clamping limit;
The ball screw is reversed to form a mold release crack width of 3 to 30% of the molded product height between the fixed mold and the movable mold, and the molded article is moved by introducing compressed air into the movable steam chamber. And a third step of releasing from the mold and depositing in a fixed mold.

  In the above-described invention, after the third step, after adding the fourth step of rotating the ball screw forward and clamping the mold to the mold clamping limit or to the middle of the mold clamping limit, By repeating the returning operation a plurality of times, it is possible to release the mold by applying a high pressure due to air pulsation to the molded product interface.

  In addition, the movable mold is moved at a predetermined pitch, and the mold is opened stepwise up to the mold release cracking width, and compressed air is introduced into the stationary steam chamber or the movable steam chamber for each movement of the movable mold. It can be carried out.

  In addition, the movable mold opening can be performed while reducing the speed to the release cracking width, and the compressed air can be introduced into the fixed steam chamber or the movable steam chamber.

  In the invention according to claim 1, since the cracking width is set by the ball screw mechanism, the cracking width can be set with high accuracy by the position holding function of the ball screw. Therefore, the cracking width is made smaller than before, and a high pressure can be easily applied to the molded product interface on the movable mold side (hereinafter referred to as the molded product front surface, and the molded product interface on the fixed mold side is referred to as the molded product back surface). As a result, the amount of compressed air consumed can be reduced and the molded product can be released from the movable mold.

  In the inventions according to claims 2 and 3, in the invention according to claim 1, since compressed air is introduced from a narrow cracking width, the molded product is effectively moved by staying and filling the compressed air in front of the molded product. Can be released from the mold.

  According to the fourth aspect of the present invention, the molded product can be released from the first to third steps by setting the cracking width to be small with high accuracy by the position holding function of the ball screw. Therefore, the consumption of compressed air can be reduced and the molded product can be released from the mold well.

  According to the fifth aspect of the present invention, by repeatedly performing mold opening and mold clamping, a high pressure can be alternately applied to the back surface and the front surface of the molded product, so that the molded product can be favorably released.

  The invention according to claims 6 and 7 is the invention according to claim 4 or 5, wherein the compressed air is introduced from the narrow cracking width, so that the molded product is retained and filled on the back or front of the molded product. The mold can be effectively released from the mold.

The present invention will be described below with reference to the drawings.
1 and 2 show a ball screw type foamed resin molding machine for carrying out the method of the present invention. In the figure, a movable die plate 2 is disposed opposite to the fixed die plate 1. Each die plate 1, 2 has a fixed mold 3 and a movable mold 4. In the center of the fixed mold 3, a raw material supply machine 50 for sending raw material beads by injection air is disposed. In addition, two ball screws 5 and 6 are mounted via nuts 7 at positions facing each other across the movable die 4.

  A high-speed moving mechanism 8 of the moving die plate 2 is disposed at the end of one ball screw 5, and a low-speed moving mechanism 9 of the moving die plate 2 is disposed at the end of the other ball screw 6. Yes. Between these ball screws 5 and 6, a power transmission member 11, such as a belt or a chain, for transmitting the rotation of one ball screw 5 or 6 to the other is interposed.

  The high-speed moving mechanism 8 includes a motor 13 in which a motor shaft 12 is directly connected to the ball screw 5. The high-speed moving mechanism 8 is used when the movable die 4 is moved to the cracking position at the time of raw material filling, or when the movable die 4 is moved backward from the cracking position at the time of releasing in order to take out the molded product after releasing.

  The low-speed moving mechanism 9 is used at the time of mold clamping after raw material filling or at the time of mold opening after molding. The low-speed moving mechanism 9 is configured to rotate the motor 21, the speed reducer 22 connected to the motor 21, and the speed reducer 22. The gear 24 is transmitted to the ball screw 6. That is, the rotation of the motor 21 is decelerated by the speed reducer 22 to rotate the gear 24, whereby the ball screw 6 can be rotated at a low speed. The reduction gear 22 and the gear 24 can be engaged and disengaged by air. Further, the rotation speed of the motor 21 is increased or decreased as necessary.

  FIG. 3 is a diagram showing a schematic configuration of the mold opening mechanism. The motor 21 is provided with a movable type 4 position detecting device 51 such as a rotary encoder. The controller 52 connected to the position detecting device 51 drives the motor 21 based on the detected position of the movable mold 4 and gradually decreases the speed of the movable mold 4 to the mold release crack width W. It is moved by a ball screw mechanism. The interiors of the fixed mold 3 and the movable mold 4 are steam chambers 32 and 42, which communicate with the cavity 60 through a vent hole of a core vent (not shown). In the figure, P1 is a high-pressure air source, P2 is a vacuum pump, and V1 to V4 are valves provided in piping. Reference numeral 62 denotes an eject pin.

<Release method 1>
After the molded product is molded, when the mold 4 is opened from the mold clamping limit (a state where the movable mold is in contact with the fixed mold with the required pressure) to the mold release crack width W, a low-speed moving mechanism is instructed by a command from the controller 51. The motor 21 is driven in the direction opposite to that at the time of clamping. As a result, the ball screws 6 and 5 are reversed at a low speed to move the movable die 4 away from the fixed die 3, and the movable die 4 can be positioned with the set cracking width W.

  In the above mold opening, the cracking width W needs to be 3 to 30% of the height of the molded product. This is because if the cracking width W is less than 3%, the molded product cannot be sufficiently separated from the mold. On the other hand, if it exceeds 30%, the cracking width W is widened and the compressed air escapes from this gap, effectively forming the molded product. This is because the mold cannot be released. Therefore, the cracking width W needs to be 3 to 30%. Such a setting of the narrow cracking width W cannot be achieved by a hydraulic cylinder type mold opening mechanism, but can be achieved only by a ball screw mechanism that can hold the position with high accuracy and without fluctuation.

  The mold opening can be performed stepwise up to the cracking width W by moving the movable mold 4 at a predetermined pitch. The pitch can be 1 mm to 10 mm corresponding to the height of the molded product. The mold opening can be performed up to the cracking width W by gradually reducing the initial speed to a high speed thereafter. The cracking width W can be set to 150 mm at maximum corresponding to the height of the molded product.

  When the mold is opened, the valve V2 is opened to introduce the compressed air into the steam chamber 42 of the movable mold 4. However, the compressed air can be introduced before the mold opening starts or after the mold opening starts. . When compressed air is introduced into the steam chamber 42 before the mold opening is started, a high pressure can be loaded and retained in front of the molded product as the mold opening starts. When compressed air is introduced into the steam chamber 42 immediately after the mold opening, the compressed air can be introduced from the stage where the mold opening is narrow and a high pressure can be applied to the front of the molded product. In either case, the release of compressed air from the cracking gap can be reduced, and release can be performed effectively. Further, during mold opening, compressed air can be introduced into the steam chamber 42 for every predetermined pitch movement of the movable mold 4. Further, the compressed air can be continuously introduced regardless of the movement mode of the movable mold 4.

  When the mold is opened, if the valve V3 is opened and the vapor chamber 32 of the fixed mold 3 is set to a negative pressure, the molded product is sucked into the fixed mold 3, so that the mold can be released more easily. As described above, the molded product is floated from the movable mold 4 and deposited in the fixed mold 3.

  After depositing the molded product in the fixed mold 3, the molded product is released from the fixed mold 3. That is, the valve V1 is opened, compressed air is introduced into the steam chamber 32, and a high pressure is applied to the rear surface of the molded product. When the valve V4 is opened and a negative pressure is applied to the steam chamber 42, the molded product is sucked to the movable mold 4 through the vent hole of the core vent, so that the molded product can be released from the fixed mold 3. . Thereafter, when the movable die 4 is retracted at a high speed and the molded product is pushed out by the eject pin 62, the molded product can be taken out.

[Example 1]
Raw material beads were filled into the cavity to form a molded product having a height of 100 mm. Then, after cooling and solidifying, first, when releasing the mold, compressed air was introduced into the steam chamber 42 of the movable mold 4 to fill it. Subsequently, the movable mold was moved twice at a pitch of 5 mm to form a cracking width W of 10 mm. Each time the mobile type was moved, the molded product was released by introducing and filling compressed air so that the required pressure was secured in the steam chamber 42. At this time, a negative pressure was applied to the steam chamber 32 of the fixed mold 3 by the pump P <b> 1 so that the molded product was sucked into the fixed mold 3.

  After releasing the molded product from the movable mold 4, compressed air was introduced into the steam chamber 32 of the fixed mold 3, and negative pressure was applied to the steam chamber 42 of the movable mold 4 to release the molded product from the fixed mold 3. After that, the movable mold 4 was further opened to drop the molded product. As described above, it was possible to release the molded product effectively by narrowing the large mold release cracking width W, which conventionally required to exceed 30 mm, to 10 mm.

<Release method 2>
Similar to Method 1, after molding the molded product, the ball screw is reversed to form a cracking width W of 3 to 30% of the molded product height between the fixed mold 3 and the movable mold 4. The mold opening can be performed stepwise at a predetermined pitch up to the cracking width W by moving the movable mold 4 at a predetermined pitch. The mold opening can be performed by setting the initial speed to a high speed and then gradually decreasing it to the cracking width W.

  At this time, the valve V1 is opened to introduce the compressed air into the steam chamber 32 of the fixed mold 3. The introduction of the compressed air can be performed before the mold opening is started, and the mold opening is started. It can be done later. In any case, since a high pressure can be applied to the back of the molded product from a narrow cracking gap, mold release can be performed effectively. The compressed air may be introduced for every pitch movement of the movable mold 4 or may be introduced continuously. Further, when the valve V1 is opened and the valve V4 is opened to apply a negative pressure to the steam chamber 42 of the movable mold 4, the molded product can be effectively floated from the fixed mold 3 and deposited in the movable mold 4.

  After depositing the molded product in the movable mold 4, the process proceeds to the second step. That is, the ball screw is rotated forward to clamp the mold to the mold clamping limit or to the middle of the mold clamping limit.

  Next, the process proceeds to the third step. That is, the ball screw is reversed after clamping to form a cracking width W of 3 to 30% of the height of the molded product between the fixed mold 3 and the movable mold 4. The mold opening can be performed stepwise up to the cracking width W by moving the movable mold 4 at a predetermined pitch. Alternatively, the initial speed can be increased and then gradually reduced to the cracking width W. At this time, the valve V2 is opened to introduce the compressed air into the steam chamber 42 of the movable mold 4, but the introduction of the compressed air can be performed before the mold opening is started or can be performed immediately after the mold opening is started. . The introduction of the compressed air may be performed every pitch movement of the movable mold 4, or may be performed continuously regardless of the movable movement mode. When the valve V2 is opened and the valve V3 is opened to apply a negative pressure to the steam chamber 32 of the fixed mold 3, the molded product can be effectively floated from the movable mold 4 and deposited in the fixed mold 3.

  After performing the above first to third steps, the molded product can be taken out by largely opening the mold with the high-speed moving mechanism 8 and pushing it out with the eject pin 62.

  In addition, after the third step, a fourth step can be added in which the ball screw is rotated forward again to clamp the mold to the mold clamping limit or to the middle of the mold clamping limit. And by repeating the operation of returning to the first step after performing the fourth step a plurality of times, high pressure can be repeatedly applied to the back or front of the molded product due to the pulsation of the air accompanying mold opening and clamping, which is small. With the mold release cracking width, the molded product can be released without causing deformation or damage. After the molded product is completely separated from the mold, the molded product can be taken out by largely opening the mold and pushing it out with the eject pin 62.

  As described above, according to the present invention, the mold release cracking width can be set narrowly and with high precision, so that a high pressure can be efficiently applied to the molded product interface. Therefore, it is possible to release the molded product satisfactorily without generating a defective product with a small amount of compressed air.

It is a top view of the foam molding machine for implementing this invention. It is a front view of the foam molding machine of FIG. It is a schematic block diagram of the foam molding machine which shows a control system and an air supply / intake system together.

Explanation of symbols

  3 fixed type, 4 mobile type, 6 ball screw, 32 fixed type steam chamber, 42 mobile type steam chamber, W cracking width

Claims (7)

A mold release method in a foam molding machine in which a die is clamped and opened by forward and reverse rotation of a ball screw,
After molding the molded product, the ball screw is reversed to form a release cracking width of 3 to 30% of the molded product height between the fixed mold and the movable mold, and compressed air is introduced into the movable steam chamber After the molded product is released from the movable mold and deposited in the fixed mold,
A method for releasing a molded product, wherein the molded product is released from a fixed mold.   The movable mold is moved at a predetermined pitch to open the mold stepwise up to the mold release crack width, and compressed air is introduced into the movable steam chamber for each movement of the movable mold. A method for releasing the described molded product.   2. The mold release method according to claim 1, wherein the movable mold opening is performed while reducing the speed to the mold release cracking width, and the compressed air is continuously introduced into the movable steam chamber. . A mold release method in a foam molding machine that is clamped and opened by forward and reverse rotation of a ball screw, after molding the molded product,
Reversing the ball screw to form a release cracking width of 3 to 30% of the molded product height between the fixed mold and movable mold, and fixing the molded product by introducing compressed air into the steam chamber of the fixed mold A first step of releasing from the mold and depositing in the movable mold;
A second step of rotating the ball screw forward to clamp the mold to the mold clamping limit or to the mold clamping limit;
The ball screw is reversed to form a mold release crack width of 3 to 30% of the molded product height between the fixed mold and the movable mold, and the molded article is moved by introducing compressed air into the movable steam chamber. And a third step of releasing from the mold and depositing in a fixed mold.   After the third step, a fourth step is performed in which the ball screw is rotated forward and the mold is clamped to the mold clamping limit or to the middle of the mold clamping limit, and the operation of returning to the first process after performing the fourth process is performed a plurality of times. 5. The mold release method according to claim 4, wherein the mold release is performed by applying a high pressure due to air pulsation to the interface of the mold by repeating.   Move the movable mold at a predetermined pitch, open the mold step by step to the release cracking width, and introduce the compressed air into the fixed steam chamber or the movable steam chamber for each movement of the movable mold The method for releasing a molded product according to claim 4 or 5, wherein: 6. The movable mold opening is performed while reducing the speed to the mold release cracking width, and the compressed air is continuously introduced into the fixed steam chamber or the movable steam chamber. The mold release method of the molded product described in 1.

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