JP2009214478A - Injection moulding apparatus and method for molding injection-molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding apparatus which is simple in structure and can increase a mold closing speed by smoothing the movement of a sliding mold by adopting a new composition for moving the sliding mold in relation to the injection molding apparatus having a movable mold, a fixed mold, and the sliding mold. <P>SOLUTION: The injection molding apparatus comprises the movable mold 3 which can move between a mold closing position and a mold opening position, the fixed mold 4 arranged at a position opposite to the movable mold 3, and the sliding mold 5 which is set slidably in relation to the movable mold, takes a retreat position retreating from a cavity in a mold opening state, and takes an advance position entering the cavity in a mold closing state. Electromagnets 6 and 7 for moving the sliding mold to the retreat position and the advance position are installed in the movable mold. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an injection molding apparatus that includes a movable mold, a fixed mold, and a slide mold, and that relates to an injection molding apparatus that can smoothly move the slide mold and increase the mold closing speed, and a method for molding an injection molded product. .

  Usually, an injection molding apparatus used for injection molding is basically configured by including a movable mold and a fixed mold which are arranged to face each other. In addition, depending on the shape of the injection-molded product to be molded, a slide mold or a insert is required. And the structure of the conventional injection molding apparatus 101 provided with a movable mold | type, a fixed mold | type, and a slide mold | type was comprised as shown in FIGS. That is, the guide rail 105 is provided on the movable mold 103, and the slide mold 107 that slides along the guide rail 105 is provided on the guide rail 105. Further, the fixed mold 109 is provided with an inclined pin called an angular pin 111 as shown in the figure, and the slide mold 107 is provided with an inclined guide surface on which the tip end portion 111a of the angular pin 111 abuts. 113 and a pin receiving hole 115 for receiving the angular pin 111 is provided.

  In the injection molding apparatus 101 having such a structure, the slide mold 107 is located at the retracted position retracted from the core 117 of the movable mold 103 as shown in FIG. Then, when the movable mold 103 is moved toward the fixed mold 109, as shown in FIG. 17, the tip end portion 111 a of the angular pin 111 comes into contact with the inclined guide surface 113 of the slide mold 107, and the slide mold 107. Is made to advance toward the core 117 side. When the injection molding apparatus 101 shifts to the mold closed state, as shown in FIG. 18, a part of the slide mold 107 enters the cavity 119 formed between the fixed mold 109 and the core 117, and the slide mold 107. Reaches the forward position. An angular pin 111 enters the pin receiving hole 115 to form an engaged state, and the forward position of the slide mold 107 is held and fixed.

However, the injection molding apparatus 101 having such a structure using the angular pin 111 cannot increase the mold closing speed for safety so that an excessive force is not applied to the angular pin 111. On the other hand, as shown in Patent Documents 1 and 2 below, for an injection molding apparatus having a basic configuration including only a movable mold and a stationary mold that are not provided with a slide mold, a large amount is required by using magnetic force. A mold opening / closing mechanism or a mold clamping device that can increase the mold closing speed without providing a hydraulic device or the like has been developed.
JP-A-6-63554 JP-A-7-186215

  However, even if the mold opening / closing mechanism or the mold clamping device is applied to the injection molding apparatus 101 having a structure in which the slide mold 107 is slid by using the angular pin 111 as described above, there is a problem in safety. The mold closing speed cannot be increased immediately.

  An object of the present invention is to smooth the movement of a slide mold and increase the mold closing speed by adopting a new configuration for moving the slide mold for an injection molding apparatus including a movable mold, a fixed mold and a slide mold. An object of the present invention is to provide an injection molding apparatus having a simple structure and a method for molding an injection molded product.

  An injection molding apparatus according to a first aspect of the present invention includes a movable mold that can move between a mold closing position and a mold opening position, a fixed mold that is disposed at a position facing the movable mold, and the movable mold. And a slide mold that takes a retracted position retracted from the cavity when the mold is open, and takes a forward position that enters the cavity when the mold is closed, and the movable mold includes the slide mold. An electromagnet that moves to the retreat position and the advance position is provided.

  According to this aspect, the slide mold is moved to the forward movement position or the backward movement position by appropriately switching between a state in which the electromagnet acts on the slide mold and a state in which the magnetic force for the forward movement is applied. Is possible. Further, since it is not necessary to provide a slide structure by the angular pin provided in the conventional injection molding apparatus and the pin receiving hole for receiving the angular pin, there is no problem in terms of safety even if the mold closing speed is increased. Therefore, the mold closing speed can be increased, and the molding cycle of the injection molded product can be shortened with a simple structure in which only an electromagnet is provided.

  According to a second aspect of the present invention, in the injection molding apparatus according to the first aspect, the start to the forward movement position of the slide type which is located in the backward position in one or both of the movable mold and the fixed mold. An assist device for assisting the operation is provided.

  According to this aspect, in addition to the magnetic force generated when the forward electromagnet is turned on when the slide mold located at the reverse position needs the maximum force to start starting toward the forward position. Thus, since the force assisting the start-up operation by the assist device is applied, the movement of the slide type to the forward movement position is started smoothly.

  According to a third aspect of the present invention, in the injection molding apparatus according to the first aspect or the second aspect, the slide mold is provided with an inclination guide action surface, and the fixed mold is provided with the inclination guide action. A locking block having a holding action surface that contacts the surface and holds the slide-type advance position is provided.

  According to this aspect, even when the holding pressure by the forward electromagnet is smaller than the injection pressure of the resin raw material injected into the cavity, the slide mold can be reliably held by the locking block, so that a desired holding pressure can be secured. it can. Further, as the movable mold is moved to the mold closing position, the slide-type tilt guiding action surface comes into contact with and presses the holding action surface of the locking block, and a force that firmly holds the slide mold at the forward position acts. Therefore, the holding of the slide type in the advanced position is also strong.

  According to a fourth aspect of the present invention, in the injection molding apparatus according to the second aspect, the assist device is an extrusion cylinder that pushes the slide mold toward the forward movement position.

  According to this aspect, the push-out force (assist force) for moving the slide mold toward the forward movement position is directly applied by the push-out cylinder, so that the starting operation of the slide mold to the forward movement position is surely executed. . Further, since the assist device can be configured only by providing the extrusion cylinder, an increase in equipment cost can be prevented.

  According to a fifth aspect of the present invention, in the injection molding apparatus according to the second aspect, the assist device is a compressed fluid supply device that floats the slide mold from a ground contact surface with respect to the movable mold. It is.

  According to this aspect, a compressed fluid such as compressed air supplied by the compressed fluid supply device acts on the bottom surface of the slide mold, and a force for floating the slide mold upward is generated. Accordingly, the frictional force between the bottom surface of the slide mold and the movable grounding surface is reduced, so that the start operation to the forward movement position of the slide mold is surely started and executed. Moreover, if a compressed air supply apparatus is comprised using the compressed air equipment in a factory, the increase in equipment cost can be suppressed.

  According to a sixth aspect of the present invention, in the injection molding apparatus according to the second aspect, the assist device is constituted by an electromagnet that floats the slide mold from a ground surface with respect to the movable mold. It is.

  According to this aspect, the magnetic force of the electromagnet provided separately acts on the slide mold, and a force for floating the slide mold upward is generated. Accordingly, the frictional force between the bottom surface of the slide mold and the movable grounding surface is reduced, so that the start operation to the forward movement position of the slide mold is surely started and executed. Moreover, since an assist device can be configured by adding only one type of electromagnet, an increase in equipment cost can be prevented.

  The injection molding product molding method according to the seventh aspect of the present invention is executed at the time of mold opening to hold the slide mold in the retracted position with the retracting electromagnet ON and the forward electromagnet OFF. Slide-type retraction process, slide-type advance process executed when the mold is closed to move the slide mold from the retreat position to the advance position with the retreat electromagnet OFF and the advance electromagnet ON, and then retreat And a pressure holding step executed in a mold closing state in which pressure is maintained in a state where the electromagnet for turning off and the electromagnet for advancement are turned on and the slide mold is positioned at the forward movement position.

  According to this aspect, the slide mold can be moved and held by simply switching the electromagnet ON / OFF in accordance with the position of the movable mold and the timing of the movement start. It will be possible to safely respond to higher speeds. Furthermore, it can contribute to shortening of the molding cycle of the injection molded product.

  Hereinafter, an injection molding apparatus 1 and an injection molded product molding method according to the present invention will be described with reference to the drawings. In the following description, the injection molding apparatus 1 including the movable mold 3, the fixed mold 4, and the slide mold 5 is taken as an example, and the present invention will be described based on four embodiments of the first to fourth embodiments.

[Example 1]
1 is an exploded perspective view showing an injection molding apparatus according to a first embodiment and a plastic molded product molded by the injection molding apparatus, and FIG. 2 is a side sectional view showing the injection molding apparatus according to the first embodiment when the mold is opened. It is. FIG. 3 is a side sectional view showing the injection molding apparatus according to the first embodiment at the start of mold closing, and FIG. 4 is a side sectional view showing the injection molding apparatus according to the first embodiment when the mold closing is completed. FIG. 5 is a plan view showing a movable mold and a slide mold of the injection molding apparatus according to the first embodiment when the mold is opened.

  The injection molding apparatus 1 according to the present embodiment is disposed at a position facing the movable mold 3 and a movable mold 3 that can move between a mold closing position L (FIG. 4) and a mold opening position N (FIG. 2). The fixed mold 4 is slidable with respect to the movable mold 3 and takes a retracted position R retracted from the cavity 20 when the mold is open, and a part of the cavity 20 enters when the mold is closed. And a slide mold 5 that takes a position F. As a characteristic configuration of the present embodiment, the movable mold 3 is provided with electromagnets 6 and 7 that generate magnetic force for the backward movement and the forward movement for moving the slide mold 5 to the backward position R and the forward position F, respectively. It has been.

  The movable mold 3 is made of a metal material, and is a rectangular step block-shaped member as shown. In the present embodiment, the movable mold 3 is formed such that the front side (left side in FIGS. 2 to 5) is the lowest and becomes higher stepwise toward the back (right side in FIGS. 2 to 5). ing. The upper surface 3a of the movable mold 3 includes a fixed block mounting base 8 on which the electromagnet fixing blocks 21 are installed in order from the front side, a slide type mounting base 9 serving as a sliding contact surface with the slide mold 5, and a core (male) 14 And a split surface 11 that is in close contact with the lower surface 4 a of the fixed mold 4.

  The electromagnet fixing block 21 installed on the fixing block installation base 8 is a square bar-like member as shown in the figure as an example, and in the concave portion 22 formed through the upper surface and part of the rear surface near the middle. The retraction electromagnet 6 described above is embedded. Further, a slide mold 5 is provided in the vicinity of the center of the slide mold installation base 9 so as to be slidable in the front-rear direction B, and is provided so as to protrude sideways at the base of the slide mold 5. Two guide rails 24, 24 that engage with the ridges 23, 23 are provided so as to sandwich the slide mold 5. In addition, a recess 22 is formed on the upper surface and the front surface in the vicinity of the middle of the core mounting base 10 so as to penetrate a part thereof. The forward electromagnet 7 described above is embedded in the recess 22.

  And the core 14 for shape | molding the external appearance except the upper surface of the plastic molding A is installed in the upper surface of the core installation base 10 in which the electromagnet 7 for advance is embedded. The core 14 is a metal block-shaped member as shown in the figure, and a molding space 26 for pouring the molten resin material C is formed on the upper surface thereof. Further, the center of the front wall 27 of the core 14 is cut out in a rectangular shape, and the cut-out portion serves as a slide receiver 29 that receives a mold component 28 projecting forward of the slide mold 5.

  The fixed mold 4 is made of a metal material and is a rectangular flat plate member as shown. A cavity (female mold) 20 that also becomes a molding space 26 is formed on the lower surface 4 a serving as a split surface of the fixed mold 4 at a position corresponding to the molding space 26 of the core 14 installed on the core mounting base 10 of the movable mold 3. Is provided. Above the cavity 20, a sprue 25 for supplying a molten resin material C injected from an injection molding machine (not shown) into the cavity 20 or the molding space 26 penetrates the upper and lower surfaces of the fixed mold 4. Is provided.

  In addition, a locking block 12 is attached to the front center portion of the lower surface 4 a of the fixed mold 4. The locking block 12 is a member provided to increase the holding pressure in the injection molding apparatus 1 in the mold closed state, and the end portion on the back side of the locking block 12 is cut obliquely to form the holding action surface 30. . The holding action surface 30 plays a role of firmly holding the slide mold 5 that has reached the forward movement position F by contacting and pressing an inclined guide action surface 31 formed on the slide mold 5 described below. Have.

  The slide mold 5 is made of a metal magnetic material, and is a block-shaped member as shown in the figure. The rectangular block-shaped main body 15 and the pair of left and right engagements formed at the lower end of the main body 15 are described above. It is formed by obliquely cutting out the joint ridges 23, 23, the mold component 28 formed so as to protrude forward from the upper front surface of the main body portion 15, and the corner portion at the upper rear of the main body portion 15. The inclined guide action surface 31 is provided. Further, a round bar-shaped shaft portion 32 is provided in the vicinity of the center of the front surface of the mold component portion 28 so as to extend further forward. The plastic molded product A molded by the injection molding apparatus 1 according to the present embodiment configured as described above has a rectangular cap shape with a small hole 33 formed on the front surface as shown in FIG. Product.

  Next, a method for molding a plastic molded product according to the present embodiment, which is executed by using the injection molding apparatus 1 configured as described above, will be described. The molding method of the plastic molded product of the present embodiment is basically configured by including (1) a slide mold retracting process, (2) a slide mold advancing process, and (3) a pressure holding process.

(1) Slide type retraction process (see FIGS. 2 and 5)
The slide mold retreating process is a process executed when the mold is opened in which the retracting electromagnet 6 is turned on and the forward electromagnet 7 is turned off and the slide mold 5 is held in the retracted position R.
In this case, as shown in the figure, the movable mold 3 is located at the mold opening position N, and the slide mold 5 has the rear surface of the main body 15 in contact with the electromagnet fixing block 21 and the retracting electromagnet 6 so that the slide mold 5 Are all held out of the molding space 26 of the core 14.

(2) Slide type advance process (see Fig. 3)
In the slide mold advancement process, the retractable electromagnet 6 is turned off and the forward electromagnet 7 is turned on in conjunction with the start of movement of the movable mold 3 to the mold closing position L, and the slide mold 5 is moved from the retracted position R. This is a process executed at the start of mold closing.

  That is, as shown in the figure, when the movable mold 3 starts moving toward the mold closing position L, the two types of electromagnets 6 and 7 are switched between ON and OFF states, the reverse electromagnet 6 is turned off, and the forward electromagnet 6 is moved forward. The electromagnet 7 is turned on. Then, the front surface of the lower end portion of the main body portion 15 of the slide mold 5 is pulled by the magnetic force of the forward electromagnet 7, and the slide mold 5 moves toward the advance position F along the guide rails 24, 24 like a lever. To start.

  The scale of the electromagnet is such that the frictional force between the bottom surface of the main body 15 of the slide mold 5 and the grounding surface 9a of the slide mold mounting base 9 of the movable mold 3 does not become larger than the magnetic force generated by the forward electromagnet 7. Alternatively, it is necessary to set the friction coefficient of the ground contact surface 9a. However, when the movement of the movable mold 3 toward the mold closing position L starts, the slide mold 5 moves to the forward movement position F even with a small force, and the forward electromagnet 7 is accompanied by the movement. Since the magnetic force due to is gradually increased, smooth movement of the slide mold 5 to the forward position F is executed.

(3) Pressure holding process (see FIG. 4)
The pressure-holding step is a step that is executed in a closed mold state in which pressure is maintained in a state where the reverse electromagnet 6 is turned off and the forward electromagnet 7 is turned on and the slide die 5 is positioned at the forward position F.

  That is, in the slide mold 5 that has moved along the guide rails 24 and 24 by the magnetic force of the forward electromagnet 7, the front surface of the lower end portion of the main body portion 15 contacts the core mounting base 10 and the forward electromagnet 7. It contacts and reaches the forward position F. In this state, the mold component 28 of the slide mold 5 enters the molding space 26 of the core 14, and the slide mold 5 functions as a forming member that forms the molding space 26 together with the core 14.

  On the other hand, the dividing surface 11 of the movable mold 3 comes into contact with the lower surface 4 a that becomes the dividing surface of the fixed mold 4, and the movable mold 3 reaches the mold closing position L. Accordingly, the cavity 20 is connected to the upper side of the molding space 26 formed by the core 14 and the slide mold 5, and the whole including the cavity 20 is the molding space 26 (this molding space 26 is called the cavity 20. In some cases). A predetermined amount of resin raw material C injected from an injection molding machine (not shown) is injected into the molding space 26 through the sprue 25, and is released as a plastic molded product A after cooling and solidification.

[Example 2]
6 is a side sectional view showing the injection molding apparatus according to the second embodiment when the mold is opened, and FIG. 7 is a side sectional view showing the injection molding apparatus according to the second embodiment when the mold closing is started. FIG. 8 is a side sectional view showing the injection molding apparatus according to the second embodiment when the mold closing is completed.

  The injection molding apparatus 1A according to the present embodiment includes all the configurations of the injection molding apparatus 1 according to the first embodiment illustrated in FIGS. 1 to 5, and includes an extrusion cylinder 34 as the assist device 16 in addition to the configurations. Is different. Therefore, the description of the same configuration as that of the first embodiment is omitted here, and the description will focus on the configuration of the extrusion cylinder 34 added in the second embodiment.

  The assist device 16 is a device that assists the starting operation of the slide mold 5 positioned at the retreat position R to the advance position F. As described above, the slide mold 5 can be smoothly moved only by the magnetic force of the forward electromagnet 7. Applicable when starting operation is difficult. In this embodiment, an extrusion cylinder 34 is provided as the assist device 16 to push the slide mold 5 toward the forward position F.

  The push-out cylinder 34 includes a cylinder body 35 and a rod 36, and the cylinder body 35 is attached using the electromagnet fixing block 21. Further, the cylinder body 35 is attached in such a direction that the rod 36 presses the rear surface of the body portion 15 of the slide mold 5.

  The stroke of the rod 36 is basically sufficient to assist the starting operation of the slide mold 5, but in this embodiment, even when the slide mold 5 has reached the forward position F as shown in FIG. The stroke is set so that the rear surface of the lower end of the main body 15 of the slide mold 5 can be pressed. Accordingly, it is configured to have an action of increasing the holding force of the slide mold 5 in the mold closed state together with the locking block 12.

  Next, a method for molding a plastic molded product according to this embodiment, which is executed by using the injection molding apparatus 1A configured as described above, will be described. As in the case of the first embodiment, the molding method of the plastic molded product of the present embodiment includes (1) a slide mold retracting process, (2) a slide mold advancing process, and (3) a pressure holding process. Basically composed. The contents in these steps are the same as those in the first embodiment except for the operation of the extrusion cylinder 34. Therefore, the description will focus on the operations of the extrusion cylinder 34 in the respective steps.

(1) Slide type retraction process (see FIG. 6)
In the slide type retraction process, the push cylinder 34 is in a state where the rod 36 is most contracted. Accordingly, the slide mold 5 is held at the retracted position R without being pressed by the push-out cylinder 34.

(2) Slide type advance process (see FIG. 7)
In the slide mold advance process, the push cylinder 34 gradually expands in conjunction with the movement of the movable mold 3 to the mold closing position L, and the slide mold 5 moves from the retracted position R in response to the pressing force from the rod 36. Move a little away. Therefore, the slide mold 5 is easily affected by the magnetic force generated when the forward electromagnet 7 is turned on, and a smooth starting operation is performed.

(3) Pressure holding process (see FIG. 8)
In the pressure-holding process, the push-out cylinder 34 is in a state where the rod 36 is most extended. Therefore, the slide die 5 that has reached the forward movement position F is held in a state where the rear surface is pressed by the push-out cylinder 34. Then, after injection, cooling, and solidification, the extrusion cylinder 34 contracts again at the time of mold opening transition to release the pressing force, and the slide mold 5 can be moved to the retracted position R.

[Example 3]
FIG. 9 is a side sectional view showing the injection molding apparatus according to the third embodiment when the mold is opened, and FIG. 10 is a side sectional view showing the injection molding apparatus according to the third embodiment at the start of mold closing. FIG. 11 is a side sectional view showing the injection molding apparatus according to the third embodiment when the mold closing is completed.

  The injection molding apparatus 1B according to the present embodiment includes all the configurations of the injection molding apparatus 1 according to the first embodiment shown in FIGS. 1 to 5, and in addition to the configuration, as an assist device 16 as a compressed fluid supply device. The point which is provided with the following compressed air supply device 37 differs. Therefore, the description of the same configuration as that of the first embodiment is omitted here, and the description will focus on the configuration of the compressed air supply device 37 added in the third embodiment.

  The compressed air supply device 37 is a compressed air supply formed between a compressed air generating device 38 such as an air compressor and the front surface of the fixed block installation table 8 of the movable mold 3 to the grounding surface 9 a of the slide type installation table 9. It is configured by providing a flow path 39 and a connection pipe (not shown) that connects the compressed air generator 38 and the compressed air supply flow path 39.

  Further, the plastic molding product molding method of the present embodiment, which is executed by using the injection molding apparatus 1B configured as described above, is similar to the case of the first embodiment. (2) A slide type advance process and (3) a pressure holding process are basically provided. The contents in these steps are the same as those in the first embodiment except for the operation of the compressed air supply device 37, and therefore the operation of the compressed air supply device 37 is exhibited here (2) Slide type The description will focus on the operation of the compressed air supply device 37 during the forward movement process.

  That is, as shown in FIG. 10, the compressed air generator 38 is started in conjunction with the operation in which the movable mold 3 starts moving toward the mold closing position L. The compressed air G generated by the compressed air generator 38 is guided to the compressed air supply passage 39 through a connection pipe (not shown), and the opening 40 formed in the grounding surface 9a of the slide type installation base 9. To the bottom surface of the main body 15 of the slide mold 5. Along with this, the slide mold 5 receives a force in a floating direction from the ground contact surface 9a, so that a frictional force generated between both is reduced. Accordingly, the movement of the slide mold 5 during the start-up operation by the magnetic force of the forward electromagnet 7 becomes smooth.

[Example 4]
FIG. 12 is a side sectional view showing the injection molding apparatus according to the fourth embodiment when the mold opening is completed, and FIG. 13 is a side sectional view showing the injection molding apparatus according to the fourth embodiment at the start of mold closing. FIG. 14 is a side sectional view showing the injection molding apparatus according to the fourth embodiment when the mold closing is completed, and FIG. 15 is a side sectional view showing the injection molding apparatus according to the fourth embodiment when the mold opening is started.

  The injection molding apparatus 1C according to the present embodiment includes all of the remaining parts except for the locking block 12 in the configuration of the injection molding apparatus 1 according to the first embodiment shown in FIGS. In addition, a separate electromagnet 41 is provided as the assist device 16. Therefore, the description of the same configuration as that of the first embodiment is omitted here, and the description will focus on the arrangement and operation mode of the electromagnet 41 added in the fourth embodiment.

  In this embodiment, a concave portion 42 is formed by penetrating a part of the lower surface 4 a of the fixed die 4 located above the slide die 5, and a separate electromagnet 41 is embedded in the concave portion 42. Then, by utilizing the magnetic force of the electromagnet 41, the slide mold 5 receives a force in a floating direction from the ground surface 9 a of the movable mold 3, so that the gap between the bottom surface of the main body 15 of the slide mold 5 and the ground surface 9 a is obtained. The sliding force of the slide mold 5 is made smooth by reducing the frictional force.

  Further, the plastic molding product molding method of the present embodiment, which is executed by using the injection molding apparatus 1C configured as described above, is similar to the case of the first embodiment. (2) A slide type advance process and (3) a pressure holding process are basically provided. The contents of these steps are the same as those of the first embodiment except for the operation of the separate electromagnet 41. Therefore, here, only the operations of the separate electromagnet 41 during the respective steps will be described.

(1) Slide type retraction process (see FIG. 12)
In the slide type retreat process, the separate electromagnet 41 is in an OFF state. Therefore, the slide mold 5 is held at the retracted position R by receiving the magnetic force of the retracting electromagnet 6 while being grounded to the grounding surface 9a.

(2) Slide type advance (see Fig. 13)
In the slide mold advancement process, the separate electromagnet 41 is turned on in conjunction with the movement of the movable mold 3 to the mold closing position L. Then, as the movable mold 3 moves, the upper surface of the main body portion 15 of the slide mold 5 approaches the separate electromagnet 41, and the magnetic force of the separate electromagnet 41 increases so that the slide mold 5 is placed in the slide mold installation base in the movable mold 3. A force is applied in the direction of floating from the ground contact surface 9a. Along with this, the frictional force between the bottom surface of the main body 15 of the slide mold 5 and the grounding surface 9a is reduced, so that the slide mold 5 is affected by the magnetic force generated when the forward electromagnet 7 is turned on. This facilitates a smooth starting operation.

(3) Pressure holding step (see FIGS. 14 and 15)
And if the starting operation | movement to the advance position F of the slide type | mold 5 is confirmed, the separate electromagnet 41 will be made into an OFF state. This is because there is a possibility that the injection molding apparatus 1C may be damaged if the slide mold 5 is floated and the mold is closed. Further, when the injection, cooling, and solidification of the resin raw material C progress and the transition is made at the start of mold opening, the forward electromagnet 7 is turned off and the backward electromagnet 6 is turned on as shown in FIG. A smooth starting operation is performed by applying a force floating from the ground surface 9a to the slide die 5 in the ON state. When the start operation of the slide mold 5 to the backward position R is confirmed, the separate electromagnet 41 is turned off again.

[Other embodiments]
The injection molding apparatus 1 and the method of molding a plastic molded product according to the present invention are based on the configuration as described above, but the partial configuration is changed or omitted without departing from the gist of the present invention. Of course, it is also possible to perform.

  For example, the arrangement of the reversing and advancing electromagnets 6 and 7 is not limited to the arrangement of the first to fourth embodiments described above, and may be arranged at an appropriate position where the same action and effect are exhibited. Is possible. Specifically, in FIGS. 2 to 4, the backward and forward electromagnets 6 and 7 can be arranged at positions as indicated by phantom lines.

  In the second embodiment, the locking block 12 can be omitted when the holding pressure in the mold closed state is sufficiently secured by the magnetic force of the forward electromagnet 7 and the pressing force of the pushing cylinder 34. . In the third embodiment, when it is desired to obtain a smoother movement of the slide mold 5, the installation area between the main body 15 of the slide mold 5 and the grounding surface 9 a of the movable mold 3 is reduced. In addition, a plurality of grooves and protrusions (not shown) can be provided on the ground contact surface 9a.

  Further, in the fourth embodiment, the locking block 12 is not provided, but this is due to the installation space, and a concave portion can be formed in a part of the holding action surface 30 of the locking block 12, and a separate electromagnet 41 is attached. In the case where it can be embedded in the recess, the locking block 12 can be provided. In addition, the assist device 16 is not limited to those shown in the above-described embodiments 2 to 4, and various configurations capable of exhibiting the same operation and effect can be adopted, and each assist device 16 is used alone. In addition, they can be used in combination as appropriate.

1 is an exploded perspective view showing an injection molding apparatus and a plastic molded product according to Embodiment 1. FIG. The side sectional view showing the injection molding device at the time of mold opening. The sectional side view which shows the injection molding apparatus at the time of a mold closing start. The side sectional view showing the injection molding device at the time of mold closing completion. The top view which shows the movable mold | type at the time of mold opening and a slide mold | type with the same injection molding apparatus. FIG. 5 is a side sectional view showing an injection molding apparatus at the time of mold opening according to a second embodiment. The sectional side view which shows the injection molding apparatus at the time of a mold closing start. The side sectional view showing the injection molding device at the time of mold closing completion. FIG. 6 is a side sectional view showing an injection molding apparatus at the time of mold opening according to a third embodiment. The sectional side view which shows the injection molding apparatus at the time of a mold closing start. The side sectional view showing the injection molding device at the time of mold closing completion. The sectional side view which shows the injection molding apparatus at the time of completion | finish of the mold opening which concerns on Example 4. FIG. The sectional side view which shows the injection molding apparatus at the time of a mold closing start. The side sectional view showing the injection molding device at the time of mold closing completion. The sectional side view which shows the injection molding apparatus at the time of a mold opening start. The sectional side view which shows the same injection molding apparatus at the time of the conventional mold opening. The sectional side view which shows the same injection molding apparatus at the time of the conventional mold closing start. The sectional side view which shows the same injection molding apparatus at the time of the conventional mold closing completion.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Injection molding apparatus (for plastic molded products), 3 movable type, 3a upper surface, 4 fixed type, 4a lower surface (divided surface), 5 slide type, 6 (for backward movement) electromagnet, 7 (for forward movement) electromagnet, 8 Fixed block installation base, 9 slide type installation base, 9a grounding surface, 10 core installation base, 11 split surface, 12 locking block, 14 core (male), 15 body, 16 assist device, 20 cavity (female), 21 Electromagnet fixing block, 22 recess, 23 engaging projection, 24 guide rail, 25 sprue, 26 molding space, 27 front wall, 28 mold component, 29 slide receiver, 30 holding action surface, 31 inclined guide action surface, 32 Shaft, 33 Small hole, 34 Extrusion cylinder, 35 Cylinder body, 36 Rod, 37 Compressed air supply device, 38 Compressed air generator, 39 Compressed air supply flow path, 40 opening, 41 (separate) electromagnet, 42 recess, A plastic molded product, C resin raw material, L mold closing position, N mold opening position, F forward position, R backward position, B front and rear direction, G Compressed air

Claims (7)

A movable mold that can move between a mold closing position and a mold opening position;
A fixed mold disposed at a position facing the movable mold;
A slide mold that is slidable with respect to the movable mold, takes a retracted position retracted from the cavity when the mold is open, and takes a forward position that enters the cavity when the mold is closed;
An injection molding apparatus, wherein the movable mold is provided with an electromagnet that moves the slide mold to the retracted position and the advanced position. The injection molding apparatus according to claim 1,
One or both of the movable type and the fixed type are provided with an assist device for assisting a starting operation of the slide type positioned at the retracted position to the forward position. The injection molding apparatus according to claim 1 or 2,
The slide mold is provided with an inclined guide working surface,
An injection molding apparatus, wherein the fixed die is provided with a locking block having a holding action surface that contacts the inclined guide action surface and holds the forward movement position of the slide mold. The injection molding apparatus according to claim 2,
2. The injection molding apparatus according to claim 1, wherein the assist device is an extrusion cylinder that pushes the slide mold toward a forward position. The injection molding apparatus according to claim 2,
The injection molding apparatus according to claim 1, wherein the assist device is a compressed fluid supply device that floats the slide mold from a contact surface with respect to the movable mold. The injection molding apparatus according to claim 2,
The assist device is constituted by an electromagnet that floats the slide mold from a ground surface with respect to the movable mold. A slide type retraction process executed at the time of mold opening for holding the electromagnet for retraction ON and the electromagnet for retraction OFF and holding the slide mold in the retreat position;
A slide type forward step executed at the time of closing the mold, in which the reverse electromagnet is turned off and the forward electromagnet is turned on to move the slide mold from the backward position to the forward position;
And a pressure holding step that is executed in a mold closing state in which the pressure is maintained in a state in which the back electromagnet is turned off and the forward electromagnet is turned on and the slide mold is positioned at the forward movement position. Molding method for injection molded products.

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