JP6164474B2 - Injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine that molds a molded body by opening and closing a mold, and particularly relates to an injection molding machine capable of suppressing a positional deviation of a mold that is opened and closed.

  In a general injection molding machine that has been used in the past, a granular thermoplastic resin as a raw material is fed into a heating cylinder, and the resin at the tip of the screw is melted by a reciprocating screw provided in the heating cylinder. Send to the nozzle side, inject the molten resin into the mold cavity from the nozzle provided on the tip of the screw, cool the molten resin in the cavity and solidify, then open the mold and mold with the protruding pin etc. The molded product is molded by removing the molded product attached to the mold from the mold.

  Such an injection molding machine that molds a molded body such as plastic is roughly composed of a mold clamping unit and an injection unit, and the mold clamping unit generally includes a fixed mold. A mold apparatus having a movable mold is provided, and the movable mold is moved forward and backward with respect to the fixed mold by a movable means such as a toggle link mechanism including a plurality of connecting arms, and the mold is closed (clamping). Or perform mold opening.

  By the way, in the toggle link mechanism used when the movable mold is clamped with respect to the fixed mold, a plurality of link arms are connected, and the movable die plate is moved along with the extension / bending operation of the connected link arms. The movable mold attached to the base is advanced and retracted. However, since there are clearances at the connecting parts of the link arms, the fixed mold and the movable mold are affected by the clearance at these multiple locations. It is known that the parallelism with the mold deteriorates. In particular, when a movable mold is clamped with respect to a fixed mold, the accumulation of clearances at the multiple locations has an adverse effect, and the parallelism between the fixed mold and the movable mold is distorted, which causes the mold to open and close. In this case, mold deviation occurs, so that the molding accuracy of the molded body to be molded is lowered, which may cause deformation, distortion, burrs, etc. in the molded body that can be a product. For the purpose of eliminating such problems, for example, in Patent Document 1, preload means applies preload in the same direction as the mold clamping force direction at the time of mold clamping, and between the pin and the bush at the time of mold clamping and at the start of mold opening. It is disclosed that the clearance generation position is not changed and the parallelism between the fixed platen and the movable platen is maintained.

  Patent Document 2 describes that the parallelism between the fixed die plate to which the fixed mold is attached and the movable plate to which the movable mold is attached is maintained so that the clamping force is uniformly transmitted to the mold. As an object, it is disclosed that the toggle mechanism is attached to the moving plate with the connecting plate and the sealing hydraulic cylinder interposed therebetween.

JP 2005-231081 A Japanese Patent Laid-Open No. 10-258451

  In conventional injection molding machines such as those disclosed in Patent Document 1 and Patent Document 2, the link arm connecting portion of the toggle link mechanism is inevitably worn with continuous operation of the injection molding machine. Therefore, if the clearance of the connecting portion becomes relatively large, when the movable mold clamped to the fixed mold is opened, mold deviation occurs, resulting in a molded product that can be a product. Deformation, distortion, burrs and the like are generated, which adversely affects the molding quality.

  The present invention solves the above-described problems, and an injection molding machine capable of improving the quality of a molded body molded by a mold by suppressing mold deviation of the mold that is opened and closed. The purpose is to provide.

The invention related to this injection molding machine
An injection molding machine comprising: a fixed die plate to which a fixed mold is mounted; and a toggle link mechanism that opens and closes the mold as the moving die plate moves forward and backward with respect to the fixed die plate.
A mold mounting plate on which a movable mold is mounted, which is secured in parallel with the fixed die plate,
The mold mounting plate is configured to be advanced and retracted together with a movable die plate that is advanced and retracted by extension and bending operations of a plurality of link arms configured in the toggle link mechanism, and the mold mounting plate and the movable die A fluid damper device is provided between the plate and the fluid, and a fluid damper device is provided to advance the mold mounting plate in the mold closing direction when fluid is supplied.

Furthermore, the invention relating to this injection molding machine
The fluid damper device includes a holding plate fixed to a moving die plate;
A fluid supply hole that is slidably provided on the holding plate and supplies the fluid to a piston portion to which the mold mounting plate is fixed, and a fluid supply portion provided between the holding plate and the piston portion. And are configured,
The fluid is supplied to the fluid supply part through the fluid supply hole, and the piston part is advanced to advance the mold mounting plate in the mold closing direction. When the clamping process of clamping the movable mold to the fixed mold is performed by the extension operation of the link arm, the fixed mold and the movable mold are kept in contact with each other while maintaining parallelism. It is characterized by.

Furthermore, the invention relating to this injection molding machine
The fluid supply part is provided as a single space part between the holding plate and the piston part, and by supplying the fluid to the fluid supply part as the space part, the mold mounting plate Is characterized in that it can be advanced in the mold closing direction with high accuracy.

  Furthermore, the invention according to the injection molding machine is characterized in that the fluid supplied to the fluid supply unit is a gas.

  Furthermore, the invention according to the present injection molding machine is characterized in that the gas is air.

  Furthermore, the invention according to the injection molding machine is characterized in that the fluid supplied to the fluid supply unit is a liquid.

  According to the invention of the present injection molding machine, before extending the link arm composed of a plurality of toggle link mechanisms and performing the mold clamping process by the toggle link mechanism, the fluid damper device is supplied with a fluid (a gas such as air or oil). The mold mounting plate is moved together with the moving die plate in the mold closing direction by extending multiple arms of the toggle link mechanism while maintaining the parallelism of the mold mounting plate to the fixed die plate. As a result, the movable mold can be brought into contact with the fixed mold. Therefore, when performing the mold clamping process, it is possible to maintain the parallelism between the fixed mold and the movable mold. That is, in the conventional case, when the mold is closed with the movable mold contacting the fixed mold, the mold clamping process is executed almost simultaneously with the mold closing. Molding that can be a product because the operation and the cumulative clearance of the connecting parts of the multiple link arms of the toggle link mechanism have an adverse effect, and these cause a positional shift of the movable mold relative to the fixed mold. However, the present invention eliminates such problems and makes it possible to obtain a high-quality molded product.

  Furthermore, according to the present invention of the injection molding machine, since the fluid supply part as a space part between the holding plate and the piston part is single, for example, when there are a plurality of fluid supply parts, the fluid is fluidized. When supplying to each of the supply units, if the supply amount to each fluid supply unit is different, it becomes difficult to maintain the parallelism of the mold mounting plate with respect to the fixed die plate, and the movable relative to the fixed mold is movable. Although there is a deviation in the parallelism of the mold, it is possible to obtain a molded article with good quality without causing such problems.

It is a block diagram which shows the metal mold | die apparatus comprised by the injection molding machine of an example of this invention. It is an important section expanded sectional view of a metallic mold device. It is explanatory drawing which shows the operation | movement order when performing a mold-clamping process, (a) shows the mold closing start of the metal mold | die opened, (b) supplies compressed air to the air supply part of an air damper apparatus. The state in which the movable mold is advanced by the toggle link mechanism in the state where the mold mounting plate is advanced in the mold closing direction and the movable mold is brought into contact with the fixed mold is shown in FIG. (D) shows a state in which the movable die plate is tilted due to the reaction force generated when the movable mold is further advanced than the influence of the clearance of the connecting portion of the link arms configured in the toggle link mechanism. Shows a state in which the link arm of the toggle link mechanism is linearly extended to perform the mold clamping process. It is explanatory drawing which shows the operation | movement order when performing a mold opening process, (a) shows the mold opening start of the metal mold | die clamped, (b) supplies compressed air to the air supply part of an air damper apparatus. (C) shows the state where the link arm of the toggle link mechanism is slightly bent, and (c) further bends the link arm of the toggle link mechanism than the state of (b) to release the mold clamping force by the toggle link mechanism. The reaction force of the air damper device affects the clearance of the connecting parts of the link arms configured in the toggle link mechanism, and the movable die plate is tilted. (D) shows the link arm of the toggle link mechanism bent. As a result, the movable mold is moved to the retreat limit, and the mold opening process is completed.

  Embodiments for carrying out the present invention will be described below with reference to FIGS. Of course, it goes without saying that the present invention can be easily applied to configurations other than those described in the embodiments without departing from the spirit of the invention.

  The injection molding machine according to the present invention is roughly classified into a mold clamping unit 3 that opens and closes a movable mold 2 with respect to a fixed mold 1 and an injection unit that injects molten resin into a cavity of a closed mold (not shown). ).

  Since the gist of the present invention relates to the mold clamping unit 3, description of the injection unit is omitted, and the mold clamping unit 3 will be described below.

  The mold clamping unit 3 is provided with a toggle link mechanism 4 that uses a non-illustrated electric motor as a drive source to move the movable mold 2 forward and backward relative to the fixed mold 1 to perform mold clamping (mold closing) and mold opening. A plurality of link arms 5 are connected to the link mechanism 4 so as to be adjacent to each other, and the movable die plate 6, the air damper device 7, The movable mold 2 is moved back and forth through the mold mounting plate 8.

  Further, a tail stock 9, a movable die plate 6 that is advanced and retracted along with an extension / bending operation of the link arm 5 of the toggle link mechanism 4, and a mold mounting plate on which the movable mold 2 is mounted, are configured in the mold clamping unit 3. 8 and a fixed die plate 11 on which the fixed mold 1 is mounted are provided on the machine base 12, and the tailstock 9 and the fixed die plate 11 fixed on the machine base 12 include a plurality of cylindrical molds. A tie rod 13 is installed, and one end of the plurality of link arms 5 of the toggle link mechanism 4 is attached to the tailstock 9 and the other end is attached to the movable die plate 6. The mold mounting plate 8 is supported by the linear motion guide 10, and by adjusting the angle of the linear motion guide 10, the parallelism between the mold mounting plate 8 and the fixed die plate 11 can be ensured.

  An air damper device 7, which is a fluid damper device, disposed between the moving die plate 6 and the mold mounting plate 8, has a holding plate 14 fixed to the moving die plate 6, and slides on the holding plate 14. A freely provided piston part 15 to which the mold mounting plate 8 is fixed, an air supply part 16 as a space provided between the holding plate 14 and the piston part 15, and air supplied from the outside An air supply hole (fluid supply hole) 17 for supplying (fluid) to the air supply part (fluid supply part) 16 is configured, and when the air is supplied to the air supply part 16 through the air supply hole 17, the piston part 15 is advanced in the mold closing direction, whereby the mold mounting plate 8 fixed to the piston portion 15 is advanced in the mold closing direction. In addition, the air supply part 16 of this embodiment is provided as a single space part instead of a plurality, and the shape of the air supply part 16 is ring-shaped, and the position of the ring-shaped air supply part 16 is Are arranged so as to face the movable mold 2 mounted on the mold mounting plate 8 and the fixed mold 1 which is opened and closed.

  Next, the operation sequence when performing the mold clamping process will be described below with reference to FIG. Note that the operation order is the order of (a) to (d).

  As shown in (a) of FIG. 3, when the mold closing is started in a state where the link arm 5 including the plurality of toggle link mechanisms 4 is bent and the movable mold 2 is retracted to the mold opening completion position, As shown in (b), the compressed air is supplied from the outside to the air supply part 16 through the air supply hole 17, whereby the piston part 15 is advanced, and accordingly, the movable mold attached to the mold attachment plate 8. 2 is advanced in the mold closing direction, and the movable arm is brought into contact with the fixed mold by extending the link arm 5 of the toggle link mechanism 4 by a predetermined amount while maintaining the state. In the state of (b), since the movable mold 2 is not pressed against the fixed mold 1, the movable die plate 6 and the piston portion 15 are slightly as shown in (b). Are separated from each other.

  Next, after the operation (b) in which the movable mold 2 is brought into contact with the fixed mold 1, as shown in (c), when the link arm 5 of the toggle link mechanism 4 is further extended, the fixed mold The movable mold 2 is pressed against the mold 1. Then, since there is a clearance in the connecting portion of the plurality of link arms 5, the moving die plate 6 is inclined due to the reaction force when the movable mold 2 is pressed against the fixed mold 1.

  Next, as shown in (d), a plurality of link arms 5 of the toggle link mechanism 4 are linearly extended, and the mold is clamped against the reaction force in (c) (the force that tilts the movable die plate 6). When the process is performed, the movable die plate 6 is further advanced in the mold closing direction, and the movable die plate 6 presses the piston portion 15 along with this, so that the movable die plate 6 tilted in FIG. The misalignment is corrected so as to be parallel to the mounting plate 8, and the mold clamping process can be executed in a state where the fixed mold 1 and the movable mold 2 maintain parallelism.

  Next, the operation sequence of the mold opening process performed after completion of the mold clamping process will be described below with reference to FIG. Note that the operation order is the order of (a) to (d).

  As shown in FIG. 4A, the mold opening start is started in the mold clamping completion state in which the plurality of link arms 5 of the toggle link mechanism 4 are linearly extended and the movable mold 2 is advanced to the advance limit. Then, as shown in (b), the link arm 5 of the toggle link mechanism 4 is bent while maintaining a state in which compressed air is supplied from the outside to the air supply unit 16 through the air supply hole 17. To go.

  Subsequently, as shown in (c), when the link arm 5 of the toggle link mechanism 4 is further bent than in the state of (b), the clamping force by the toggle link mechanism is almost released. Then, the reaction force generated when the movable mold 2 is pressed against the fixed mold 1 by the air damper device 7 affects the clearance of the connecting portions of the link arms 5 of the toggle link mechanism 4, and the movable die plate 6 It will be tilted. At this time, the movable die plate 6 is inclined, but since the compressed air of the air damper device 7 is supplied to the air supply unit 16, the movable die 2 is in relation to the fixed die 1. Parallelism is maintained without displacement.

  Next, after the operation of (c), when the plurality of link arms 5 of the toggle link mechanism 4 are further bent, the compressed air is supplied to the air supply unit 16, thereby The movable mold 2 that has been in contact with the mold is opened while maintaining parallelism, and before the movable mold 2 and the fixed mold 1 are separated from each other, the supply of compressed air to the air supply unit 16 is released (to the atmosphere). As a result, the link arm 5 of the toggle link mechanism 4 is completely bent as shown in (d) in a state in which it is not easily affected by the moving die plate 6 tilted in (c). Thereby, the movable mold 2 is retracted to the mold opening completion position, and the mold opening process is completed.

  According to the injection molding machine in the present embodiment, the movable die plate 6 that is advanced and retracted by the extension / bending operation of the plurality of link arms 5 that are configured in the toggle link mechanism 4 and the movable die 2 are attached to the movable die plate. 6 is moved between the mold mounting plate 8 and the mold mounting plate 8 and the movable die plate 6, and the mold mounting is performed by supplying air (more specifically, compressed air). An air damper device for advancing the plate 8 in the mold closing direction and bringing the movable die 2 into contact with the stationary die 1. The air damper device 7 includes a holding plate 14 fixed to the movable die plate 6. A piston portion 15 slidably provided on the holding plate 14 and capable of moving back and forth in the mold closing direction; an air supply portion 16 provided between the holding plate 14 and the piston portion 15; An air supply hole 17 for supplying the air to the air supply unit 16 is configured, and the air is supplied to the air supply unit 16 through an air supply hole 17 from an external air supply unit (not shown), and the piston unit 15 is moved forward, the mold mounting plate 8 is moved forward in the mold closing direction, and fixed before performing the mold clamping process of clamping the movable mold 2 to the fixed mold 1 mounted on the fixed die plate 11. The movable mold 2 is elastically brought into contact with the mold 1.

  Thereby, by extending the link arm 5 composed of a plurality of toggle link mechanisms 4 and supplying the air to the air supply unit 16 of the air damper device 7 before executing the mold clamping process by the toggle link mechanism 4, Since the mold mounting plate 8 can be advanced in the mold closing direction and the movable mold 2 can be elastically contacted with the fixed mold 1, the fixed die plate can be used when performing the mold clamping process. 11 and the mold mounting plate 8 can be maintained in parallel, that is, the fixed mold 1 mounted on the fixed die plate 11 and the movable mold 2 mounted on the mold mounting plate 8. Parallelism can be maintained. Therefore, in the conventional case, when the mold is closed with the movable mold contacting the fixed mold, the mold clamping process is executed almost simultaneously with the mold closing. Molding that can be a product because the operation and the cumulative clearance of the connecting parts of the multiple link arms of the toggle link mechanism have an adverse effect, and these cause a positional shift of the movable mold relative to the fixed mold. However, the present invention eliminates such problems and makes it possible to obtain a high-quality molded product.

  Furthermore, according to this injection molding machine, since the air supply part 16 as a space part between the holding plate 14 and the piston part 15 is single, for example, when there are a plurality of air supply parts, air is supplied. When supplying to each of the air supply units, if the supply amount to each air supply unit is different, it becomes difficult to advance the mold mounting plate uniformly in the mold closing direction, and the movable mold to the fixed mold However, it is possible to obtain a molded article of good quality without causing such a problem.

  Although one embodiment of the present embodiment has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the present invention. In the present embodiment, air is supplied to an air supply unit 16 as a fluid supply unit of the air damper device 7, but the air may be a gas (fluid) other than air, or a liquid such as oil ( Fluid).

DESCRIPTION OF SYMBOLS 1 Fixed metal mold 2 Movable metal mold 3 Clamping unit 4 Toggle link mechanism 5 Link arm 6 Moving die plate 7 Air damper device (fluid damper device)
8 Die mounting plate 9 Tail stock 11 Fixed die plate 12 Machine base 13 Tie rod 14 Holding plate 15 Piston part 16 Air supply part (fluid supply part)
17 Air supply hole (fluid supply hole)

Claims (5)

An injection molding machine comprising: a fixed die plate to which a fixed mold is mounted; and a toggle link mechanism that opens and closes the mold as the moving die plate moves forward and backward with respect to the fixed die plate.
A mold mounting plate on which a movable mold is mounted, which is secured in parallel with the fixed die plate,
The mold mounting plate is configured to be advanced and retracted together with a movable die plate that is advanced and retracted by an extension / bending operation of a plurality of link arms configured in the toggle link mechanism,
A fluid damper device is provided between the mold mounting plate and the movable die plate and advances the mold mounting plate in the mold closing direction when a fluid is supplied.
The fluid damper device includes a holding plate fixed to a moving die plate;
A piston portion slidably provided on the holding plate, to which the mold mounting plate is fixed;
A fluid supply hole configured to supply the fluid to a fluid supply portion provided between the holding plate and the piston portion; and
The fluid is supplied to the fluid supply part through the fluid supply hole, and the piston part is advanced to advance the mold mounting plate in the mold closing direction. When the clamping process of clamping the movable mold to the fixed mold is performed by the extension operation of the link arm, the fixed mold and the movable mold are kept in contact with each other while maintaining parallelism. molding machine out morphism characterized. The fluid supply part is provided as a single space part between the holding plate and the piston part, and by supplying the fluid to the fluid supply part as the space part, the mold mounting plate 2. The injection molding machine according to claim 1 , wherein the machine can be advanced in the mold closing direction with high accuracy. The injection molding machine according to claim 2 , wherein the fluid supplied to the fluid supply unit is a gas. The injection molding machine according to claim 3 , wherein the gas is air. The injection molding machine according to claim 2 , wherein the fluid supplied to the fluid supply unit is a liquid.

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