JP3697546B2 - Link-type oblique punching slide structure in injection mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold for performing injection molding, and in particular, when an undercut portion that is caught in the mold separation direction (drawing direction) is present in a product to be molded. This is related to a structure that smoothly moves out of the undercut portion as the mold is released.
[0002]
BACKGROUND OF THE INVENTION
For example, injection molding is generally widely known as a technique for processing a large amount of plastic products, and is applied to various products. In this method, a molten resin material is injected at a high pressure into a mold that usually includes a pair of a fixed mold plate and a movable mold plate, and is molded into an appropriate shape. Here, when taking out the product from the mold, if there is a protruding or retracted part on the side surface of the product with respect to the take-out direction, that is, the mold separating direction, the product may not be taken out from the mold. In this way, it is impossible to take out in the normal separation direction (extraction direction) of the fixed mold plate and the movable mold plate, and the hooked portion is a portion called an undercut in the product. Examples include holes to be formed and cup handles.
[0003]
When such an undercut portion is present in a product to be molded, for example, if an elastic material such as polyethylene or polypropylene is applied to the material of the product, the product is called a forcible die. However, in many cases, the undercut portion is formed by a sliding block called a slide core, and this slide core is slidably provided on a movable mold plate. The undercut portion is configured to escape as the mold is released. As an example, as shown in FIG. 3, this slide core structure is formed so that the angular pins AP provided on the fixed mold plate 2 ′ have an appropriate angle with respect to the separation direction of the mold 1 ′. . In the molded state, the angular pin AP is configured to be fitted into the slide core SC as shown in FIG. 3A, and in the mold-released state as shown in FIG. 3B. As the movable mold plate 3 'is moved away, the slide core SC is guided by the angular pin AP to avoid the undercut portion UC. Incidentally, in the structure shown in the figure, the slide core SC is guided downward by the angular pin AP and moves downward.
[0004]
However, such a slide core structure has a problem in the following points. That is, in such a method, the slide core SC normally slides on the mold dividing surface (parting line) PL that forms an angle of about 90 ° with the withdrawal direction as the movable mold plate 3 ′ moves away. It is inevitable that the mold 1 'itself is complicated or enlarged to some extent, resulting in an increase in the manufacturing cost of the mold 1'. In addition to the above, in an actual injection mold, around the cavity portion having an appropriate shape, not only the slide core SC but also, for example, a molten resin is filled in the mold 1 ′, A cooling hole for cooling this, and an ejector pin that protrudes the product A stuck to the movable mold plate 3 'after the mold 1' is separated must be constructed. The arrangement of the cooling holes, the ejector pins, and the like are restricted by the number or securing the moving space, and the degree of freedom is also reduced.
[0005]
[Technical issues for which development was attempted]
The present invention has been made in view of such a background. When a product having an undercut portion is injection-molded, a part of a mold member is smoothly withdrawn from the undercut portion, and the retreat is performed. This is an attempt to develop a new link-type diagonally-extracted slide structure that has a simpler structure and reduces the manufacturing and maintenance costs of the mold.
[0006]
[Means for Solving the Problems]
That is, the link-type oblique punching slide structure in the injection mold according to claim 1 forms a cavity portion having an appropriate shape inside the mold by a fixed mold plate having an appropriate shape and a movable mold plate. Injection molding that molds a product having an undercut portion that becomes caught in the mold release direction when the product is taken out from the mold when the molten resin is injected into the cavity portion. In the mold for
On the retreat side of the movable template, a retreat setting member is provided, and a slide unit that can be bent and protrudes to the undercut portion while being rotatably held by the retreat setting member is incorporated.
At the time of molding, the slide unit that was set to protrude to the undercut part in a substantially straight state is bent into a half-folded state when the product is taken out, with the relative separation between the movable template and the set-out member. by, those comprising as a feature that it has a so that dismissed slide unit from the undercut portion.
According to the present invention, the slide unit that retreats from the undercut portion as the mold is released can be simply configured, so that the operation is smooth and the mold cost can be reduced. In addition, since the slide unit can be arranged in a relatively narrow space, the degree of freedom of ejector pins and the like for projecting a product immediately after molding is high, and a retreat stroke can be ensured relatively long compared to the conventional structure.
[0007]
Further, in addition to the requirement of the first aspect, the link-type oblique punching slide structure in the injection mold according to the second aspect is characterized in that the slide unit has a two-bar link structure.
According to the present invention, the slide unit can be configured more simply and the mold can be easily maintained.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below based on the illustrated embodiments. In description, after demonstrating roughly the metal mold | die 1 to which this invention is applied, the link type diagonal extraction slide structure of this invention is demonstrated substantially, describing the operation | movement aspect of this metal mold | die 1. FIG. The mold 1 is for molding a product A having an appropriate shape by injecting molten resin into the inside. As an example, as shown in FIG. 1, a fixed mold plate 2 and a movable mold plate 3 are used as main members. In this case, the retreat setting member 4 and the slide unit 5 are incorporated. In the mold 1, a fixed mold plate 2 as a main member and a movable mold plate 3 are precisely molded by an NC (numerical control) machine or the like, and combined with each other to form a cavity portion where molten resin is injected. To do. At this time, it is possible to directly mold each template, but many adopt a structure in which a separately molded block member is fitted into each template.
[0009]
In the present invention, the target product A is premised on the presence of an undercut portion UC that is caught in the separating direction of the mold 1 when the product A is taken out. In addition to the above-described components, the mold 1 is formed with cooling holes for cooling the injected resin material, or ejector pins that project the molded product A from the mold 1 at appropriate positions. . In the embodiment shown in FIG. 1, the form in which the mold 1 is separated in the substantially horizontal direction is shown, but various forms such as the form in which the mold 1 is separated in the substantially vertical direction can be adopted. Each component will be described below.
[0010]
The fixed mold plate 2 is provided in a fixed state with respect to a heating cylinder that heats and melts a resin material at the time of molding, and molten resin is injected from the heating cylinder. Sprues, runners, gates, and the like are formed, and molten resin is injected into the cavity through these.
[0011]
On the other hand, the movable mold plate 3 is configured to be withdrawn from the fixed mold plate 2 so that the product A immediately after the molding can be taken out with the mold 1 being released. In addition, a guide portion 31 for guiding a slide unit 5 described later is formed. Therefore, the guide portion 31 is formed in the same direction as the undercut portion UC, and is provided so as to have an appropriate angle with respect to the moving direction of the movable mold plate 3, that is, the mold moving direction. As an example, a guide cylinder 32 and a guide hole 33 are applied to the guide portion 31 as shown in FIG. Further, in the normal mold structure, when the mold 1 is opened after cooling is finished, the product A is first left on the movable mold 3 and is ejected from the movable mold 3 by an ejector pin or the like while maintaining the relation with the mold opening operation. I am doing so.
[0012]
Next, the retreat setting member 4 will be described. This is provided on the retreat side of the movable mold plate 3, and substantially moves the slide unit 5 away from the undercut portion UC by moving away from the movable mold plate 3. The rotation base end side of the slide unit 5 is held by a separately formed mounting block 41, and the mounting block 41 is fixed to the retreat setting member 4 by a hexagon socket bolt B or the like. For this reason, an open space 42 that allows the slide unit 5 to rotate at an appropriate angle is formed at the rotation base end of the slide unit 5 in the retreat setting member 4.
[0013]
Next, the slide unit 5 will be described. This is configured to retreat from the undercut portion UC as the mold 1 is released, and as an example, a link that is rotatably held by the retreat setting member 4 as shown in FIG. 51 and a link shaft 52 having one end rotatably connected to the link 51 and the other tip protruding to the undercut portion UC. Here, a portion that is formed at the distal end portion of the link shaft 52 and projects to the undercut portion UC is labeled with a projecting portion 52a, and more clearly with respect to the substantial undercut portion UC formed in the product A. It is something to distinguish. Further, a connection portion between the retreat setting member 4 and the link 51 is distinguished as a base end portion 53, and a connection portion between the link 51 and the link shaft 52 is distinguished as a connection portion 54. The slide unit 5 is slidably fitted into the guide cylinder 32 and the guide hole 33 described above, and the link 51 and the link shaft 52 are configured to be foldable at the connecting portion 54, whereby the projection of the link shaft 52 is achieved. The portion 52a is moved away from the undercut portion UC. In this embodiment, the slide unit 5 adopts a two-bar link structure formed by connecting the link 51 and the link shaft 52, but it is also possible to adopt a three-bar link structure or the like.
[0014]
Next, the link type oblique punching structure of the present invention will be described substantially while describing the operation mode of the mold 1 configured as described above.
(1) Molding state First, prior to substantial molding, the movable mold plate 3 is moved until it is aligned with the fixed mold plate 2 by a clamping device such as a clamping cylinder, and the mold 1 is as shown in FIG. After the molding state is set, the mold 1 is further tightened by the resin material injected into the mold 1 so that the mold 1 does not open. At this time , an appropriate cavity portion is formed by the fixed mold plate 2 and the movable mold plate 3 in the mold 1. Thereafter , a certain amount of molten resin is injected from the heating cylinder into the cavity portion through a raw material injection portion such as a sprue, a runner, and a gate. Then, the molten resin is deprived of heat by the coolant inside the mold 1 and is gradually cured to complete the substantial molding.
[0015]
(2) Mold Release State Next, in order to take out the molded product A from the mold 1, the mold 1 is set to a mold release state as shown in FIG. At that time , the operation of moving the movable mold plate 3 away from the fixed mold plate 2 and the operation of moving the retreat setting member 4 relatively away from the movable mold plate 3 will be described separately.
(I) Operation for moving the movable mold plate away from the fixed mold plate The movable mold plate 3 is moved away from the fixed mold plate 2 by a clamping device such as a clamping cylinder. At least the retreated dimension is secured so that the molded product A can be reliably taken out without hitting the fixed mold 2 or the like.
[0016]
(Ii) Operation for moving the retreat setting member away from the movable mold plate The retreat setting member 4 is moved away from the movable mold plate 3 with or before or after the mold release operation between the movable mold plate 3 and the fixed mold plate 2 described above. A relatively separating operation is performed. In the description, the mode in which only the retreat setting member 4 is separated in the mold retreat direction while the movable mold plate 3 is stopped is basically described. FIG. 2A shows the close contact state, and FIG. 2B shows both separated states. Then, by moving the retraction setting member 4 away from the mold retreating direction, the base end portion 53 of the slide unit 5 moves along the retreating direction along the mold retreating direction, while the connecting portion 54 is restricted by the guide portion 31. Therefore, it moves in the forming direction of the guide part 31, that is, the undercut direction, and the protruding part 52a is moved away from the undercut part UC.
[0017]
Further, by such an operation, the link 51 rotates in the open space 42 around the base end portion 53, the link shaft 52 slides while being regulated by the guide portion 31, and the link unit 51 and the link shaft are formed as the entire slide unit 5. 52 is in a state of being bent at the connecting portion 54. In this embodiment, as described above, while the movable mold plate 3 is stopped, only the retreat setting member 4 is separated in the mold retreat direction. For example, the retreat setting member 4 is stopped on the contrary. Various forms such as a form in which the movable mold plate 3 is moved away from the fixed mold plate 2 can be adopted, and the retreat setting member 4 and the movable mold plate 3 are relatively separated from each other in any form. Any form can be used as long as it can be used.
[0018]
(3) Product removal After the operation of moving the movable mold plate 3 away from the fixed mold plate 2 and the operation of moving the move-out setting member 4 relatively away from the movable mold plate 3 are completed as described above, it is necessary as appropriate. The product A is ejected by an ejector pin or the like formed at the position, taken out from the mold 1, and one-shot molding is completed.
[0019]
【The invention's effect】
First, according to the link-type obliquely-extracted slide structure in the injection mold according to claim 1, the slide unit 5 that retreats from the undercut portion UC as the mold 1 is released can be simply configured, and therefore the operation thereof is performed. It is smooth and can reduce the mold cost. Further, since the slide unit 5 can be arranged in a relatively narrow space, the degree of freedom of the ejector pin or the like that projects the product A immediately after molding is high, and the retreat stroke can be secured relatively longer than the conventional structure.
[0020]
Moreover, according to the link type diagonally-extracted slide structure in the injection mold according to claim 2, the slide unit 5 can be configured more simply and the maintenance of the mold 1 can be easily performed.
[Brief description of the drawings]
FIG. 1 is an explanatory view (a) showing a molding state of a mold to which the present invention is applied, an explanatory view (b) showing a releasing state, and a slide unit withdraws from an undercut portion in accordance with such a state change. It is a perspective view (c) which shows the state to do.
FIG. 2 is an explanatory diagram (a) showing an initial state of the slide unit, and an explanatory diagram (b) showing an operating state.
FIG. 3 is an explanatory view (a) showing a molding state of a mold to which a conventional slide core structure is applied, and an explanatory view (b) showing a release state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mold 2 Fixed mold plate 3 Movable mold plate 4 Retraction setting member 5 Slide unit 31 Guide part 32 Guide cylinder 33 Guide hole 41 Mounting block 42 Open space 51 Link 52 Link shaft 52a Projection part 53 Base end part 54 Connection part A Product B Hexagon socket head cap bolt AP Angular pin PL Mold parting surface (parting line)
SC Slide core UC Undercut part

Claims (2)

A cavity part having an appropriate shape is formed inside a mold by a fixed mold plate having an appropriate shape and a movable mold plate, and a product is molded by injecting molten resin into the cavity part for molding. In the mold for injection molding that molds a product having an undercut portion that is caught in the mold release direction that is the take-out direction when taking out from
On the retreat side of the movable template, a retreat setting member is provided, and a slide unit that can be bent and protrudes to the undercut portion while being rotatably held by the retreat setting member is incorporated.
At the time of molding, the slide unit that was set to protrude to the undercut part in a substantially straight state is bent into a half-folded state when the product is taken out, with the relative separation between the movable template and the set-out member. is allowed, the link type oblique vent sliding structure in an injection mold, characterized in that the so that dismissed slide unit from the undercut portion.   The link type oblique punching slide structure in an injection mold according to claim 1, wherein the slide unit has a two-bar link structure.

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