JP2670089B2 - Mold for resin molding - Google Patents

Description

Description: [Industrial field of use] The present invention relates to a resin molding die having a gate cut function. More specifically, the present invention relates to a resin molding die capable of cutting a gate from an injection-molded product before opening the mold.

[Prior Art] In injection molding in which a mold cavity is filled with molten resin through a gate of a mold to manufacture a molded product, the molded product taken out of the mold inevitably has a gate. Therefore, in general, after removing the molded product from the mold, the gate is cut with a tool such as a nipper, but this has the drawback that it takes time and the cut surface cannot be treated beautifully, and the quality of the molded product deteriorates. Had been the cause of inviting.

In view of the above situation, as shown in Japanese Patent Application Laid-Open No. 60-68922, there is known one in which a molded article ejecting pin can perform gate cutting in a mold open state.

Further, as disclosed in Japanese Patent Laid-Open No. 60-68922, there is also provided a structure in which a cutter for advancing and retreating on the parting surface to cut the gate portion is provided after the mold is opened.

[Problems to be Solved by the Invention] Since the former ejector pin has a structure in which the ejector pin protrudes at the time of mold release in the mold opening process, there is nothing to press on the mold opening side, and a special mold structure is excluded. It was not possible to make a sufficient cut.

Further, the latter cutter cutting structure is not practical because it requires a large amount of cutter sliding equipment for advancing and retreating from outside the die along the batting surface.

By the way, in the present day when there is a demand for a high cycle (high speed) of the injection type, even the structure of the above-mentioned conventional technology is not suitable because it is a technology on the premise that the mold is opened. That is, in the former ejector pin structure, in addition to the predetermined time until the mold is opened, the disadvantage that the time required for the ejector pin's ejecting stroke is inevitable.

In the latter cutter structure, in addition to the time required for opening the mold as described above, it takes a long stroke for the cutter to slide from the outside of the mold to the gate position on the parting surface. Met.

In view of the above situation, the present applicant has provided in Japanese Patent Application No. 62-178654 a resin molding die capable of performing gate cutting immediately before the die opening without being affected by the die opening process. The present invention relates to this improvement. That is, according to the present invention, positioning means and a ring-shaped bearing are provided on the outer surface of the rotating piece having the gate portion along the outer periphery so that the rotation in the mold closed state can be facilitated and a reliable gate cut can be performed. , Its main purpose.

[Means for Solving the Problems] A resin molding die according to the present invention for achieving the above object is to open and close a mold with either a movable mold plate or a fixed mold plate with a parting surface closed. A rotatable rotating piece is mounted so as to intersect the direction, and the rotating piece has a runner portion and a gate portion on the end face located on the parting surface and a positioning means on the outer surface, and a ring shape along the outer periphery. The feature is that the bearing is mounted.

[Operation] Since the rotating piece has the same surface as the parting line, it forms the gate of the resin passage in the mold closing step. Therefore, the molten resin is shaped into the cavity from the runner portion of the rotating piece through the gate portion.
Since the rotating piece is rotated via the bearing with the movement of the other template while the parting surface is closed, this rotation cuts the gate portion. Other objects and features of the present invention will be clarified in the following description with reference to the accompanying drawings.

[Embodiment of the Invention] FIGS. 1 to 5 show a first embodiment of a resin molding die according to the present invention.

In the drawing, 1 is a fixed mold plate, 2 is a movable mold plate, 3 is a parting surface, and the movable mold plate 2 as one of the mold plates is provided with 20 rotating pieces.

The rotating piece 20 has a columnar portion 21 and a collar portion 22, and has a movable mold plate 2
It is rotatably housed in a housing hole 4 formed in. The end surface 23 of the rotating piece 20 has a substantially circular shape and has a parting surface 3
In this embodiment, a sprue lock hole 24 facing the sprue 5 of the fixed mold plate 2 is provided along the axis of the sprue lock hole 24. The sprue locker pin 6 can be moved back and forth in the sprue lock hole 24. Has been inserted into.

In addition, runners 25, 2 are parallel to the end surface 23 of the rotating piece 20.
5 is extended, and the gate portions 26, 26 are formed at the outer peripheral portion communicating with the runner portions 25, 25. The gate spaces 26, 26 communicate with the cavity spaces 7, 7 through a narrow passage. Further, spiral grooves 27, 27 are formed on the outer peripheral surface of the cylindrical portion 21 of the rotary piece 20.

Further, the flange 22 of the rotating piece 20 is configured by mounting a ring-shaped bearing 30 as shown in the figure along the outer periphery of the small diameter portion 29 of the neck 28. Reference numeral 31 denotes a fixing flange for fixing the bearing 30 after the fitting, and has a diameter substantially equal to or smaller than that of the rotating flange 32 of the bearing 30.

Furthermore, positioning means 33 can be provided on the outer surface of the rotating piece 20. A concave groove 34 as a positioning means 33 is formed in the fixed collar 31, and a click mechanism 35 is provided on the template. The click mechanism 35 can be configured by pressing the ball so that it can be retracted and retracted by the spring 36.

A pair of rotary operation bodies 40, 40 as means for engaging the spiral grooves 27, 27 and applying a rotational force are provided on the fixed side. That is, the rotation operation body 40 is installed in a state in which the locking arm portion 41 at the base end is attached to the fixed side mounting plate 8 and the projection 43 of the arm portion 42 at the tip is engaged with the spiral groove 27. by this,
When the rotary operation body 40 is moved up and down, the projection 43 is moved into the spiral groove 27.
The rotary piece 20 is rotated.

The fixed side mounting plate 8 is provided with a restriction pin 9 with respect to the fixed mold plate 1.
It is configured so that it can be separated via the. In the illustrated embodiment, two gate portions 26, two cavities 7 and two spiral grooves 27 are provided, but the number is not particularly limited.

In the figure, 10 is a rocket ring, 11 is a sprue bush, and 12 is a movable side holding plate. 13 is a spacer block, 14 is an ejector plate, and 15 is a movable side mounting plate.

According to the above configuration, in the mold closed state shown in FIGS. 2 and 3, the protrusions 43, 43 of the rotary operation members 40, 40 are engaged at predetermined positions of the spiral grooves 27, 27 of the rotary piece 20, The rotating piece 20 is in the initial position. In the initial position, the resin passage is sprue 5
-> Since the sprue lock hole 24-> the runner portion 25-> the gate portion 26 communicates with the cavity space 7, the cavity space 7 is filled by the above-mentioned route to the molding.

Next, at the timing of gate seal or pressure holding completion,
The fixed side mounting plate or the stripper plate (not shown) is separated as shown in FIG. 4 with the parting surface 3 kept closed. Along with such separation, the rotary operation body 40 having the locking arm portion 41 locked to the fixed-side mounting plate 8 moves, so that the rotary piece 20 has the spiral groove 27, guided by the projections 43, 43. By 27, it is forced to rotate in a direction intersecting the opening / closing direction. At this time, since the rotating piece 20 is mounted in the storage hole 4 while being surrounded by the bearing 30, the rotating piece 20 can be smoothly rotated.

As a result, the gate portion 26 and the runner portion 25 on the surface 23 of the rotating piece 20 are displaced to different positions, so that a gate cut is made. Since the sprue pin 6 is located at the center, it is rotated about this as the central axis.
At the position where the protrusion 43 is removed from the spiral groove 27, the click mechanism 45 is engaged with the concave groove 34 and positioned.

Thereafter, as shown in FIG. 5, when the parting surface 3 is opened, the molded product P, which has already been gate-cut, is released in a separated state. The passage portion molded product G is pushed out from the sprue lock hole 15 by the forward movement of the sprue-foller pin 6.

During the mold closing process, the movable piece 2 is moved forward so that the rotary piece 20 and the rotary operation body 40 relatively come close to each other. At that time, since the upper portion 27a of the spiral groove 27 is set at a fixed position by the positioning means 33, the projections 43, 43 project to the spiral grooves 27, 27.
43,43 can be accurately engaged. With the subsequent mold closing transition, the rotating piece 20 is rotated in the opposite direction to return to the initial position.

As described above, according to the above-described embodiment, since the rotating piece 20 is configured by mounting the bearing 30 on the small-diameter portion 29 of the neck portion 28, it is easy to manufacture, and the rotating operation body 40 enables smooth rotation. To be

The torque applying means can be implemented as in the second embodiment of FIG. In addition, the same parts are indicated by the same reference numerals.

That is, the rotary operation body 52 is extended from the slide core 51 of the angular pin 50, and the protrusion 43 of the rotary operation body 52 has a cylindrical portion.
It is engaged with the concave grooves 54 of 21.

According to the above configuration, in the mold closed state, the angular pin 50
Is engaged with the slide core 51, so that the rotating piece
20 is in a state where the runner portion 25 and the gate portion 26 communicate with the cavity space 7. With the retreat of the angular pin 50 due to the movement of the fixed side mounting plate 8 after molding,
When the slide core 51 is detached laterally, the rotating piece 20 is rotated counterclockwise in the figure via the bearing 30. As a result, the gate portion 26 is cut with the parting surface 3 kept closed. Although not shown, a pair of springs are urged from the opposite direction on the outer periphery of the cylindrical portion 21,
Circumferential positioning can be performed.

As described in each of the above embodiments, it is apparent that the rotating piece 20 can be connected to various kinds of rotational force applying means and can be applied to various types of mold structures. Moreover, it is possible if at least the surface 23 of the rotating piece 20 has a gate portion.

Further, in the above embodiment, the rotary piece 20 is housed in the movable mold plate 2, but as shown in FIGS. 7 to 9, the fixed mold plate 1 is used.
The above-mentioned rotating piece 20 can be fitted therein. That is, the storage hole 70 is formed in the fixed mold plate 1 and the rotary piece 20 is mounted. Rotating piece
Bearings in storage holes 70 to facilitate rotational movement of 20
It is advisable to insert 71 so as to rotatably support the rotary piece 20. Here, since the mounting plate 8 need only hold the flange portion 22 of the rotary piece 20, the rotary plate 20 may be housed in the fixed mold plate 1 and then the mount plate 8 may be fixed to the fixed mold plate 1. . Further, according to this structure, the sprue 5 can be formed along the axis of the rotating piece 20.

On the other hand, the rotary operation bodies 30, 30 for rotating the rotating piece 20 when the template is opened and closed are fixed to a mounting plate 73 slidably provided on the rotary template 2. The engaging structure of the rotating piece 20 and the rotating operation bodies 30, 30 here is the spiral grooves 27, 27 provided on the peripheral surface of the rotating piece 20 and the rotating operation body 30 fitted into this, as in the above embodiment. , 30 projections 43, 33. Therefore, when the fixed mold plate 1 and the movable mold plate 2 are in the mold closed state, the mounting plate 73 is moved back and forth with respect to the movable plate 2 to rotate the rotating piece 20.
Can be rotated. As a result, when the gate sealing or pressure holding is completed after the molding process by filling the resin, the gate cutting is performed as in the above embodiment.

As described above, the rotating piece 20 in the mold of the present invention can be arbitrarily provided on either the movable mold plate or the fixed mold plate, thereby increasing the degree of freedom in design.

Further, in any of the above-described embodiments, the one-to-two rotary operation body 30 is used to rotate the rotary piece 20,
If the rotating piece 20 can be rotated under the above conditions, only one rotating operation is required.

As described above, the rotating piece 20 in the mold of the present invention can be arbitrarily provided on either the movable mold plate or the fixed mold plate, thereby increasing the degree of freedom in design.

Further, in any of the above-described embodiments, the one-to-two rotary operation body 30 is used to rotate the rotary piece 20,
If the rotating piece 20 can be rotated under the above conditions, only one rotating operation is required.

In the embodiment shown in FIGS. 7 to 8, the spiral grooves 27, 27 are formed on the peripheral surface of the cylindrical portion 21 of the rotary piece 20, but as shown in FIG. 9, the spiral groove is formed on the peripheral surface of the collar portion 22. May be formed. As a result, the rotational torque for rotationally driving the rotary piece 20 increases, and the rotary piece 20 can be reliably rotated. Further, according to this structure, since the interval between the rotary operation bodies 30 and 30 is widened, restrictions due to the rotary operation bodies in designing the cavity shape can be somewhat reduced. In this embodiment, after the rotary piece 20 is fitted into the storage hole 81 formed in the fixed mold plate 1, the rotary piece 20 is held by the pressing ring 82 so that it cannot be pulled out.

In addition, a sprue push 83 that is coupled to the rotary piece 20 is attached to the fixed side mounting plate, and the sprue 5 is attached along the axis of these.
Is formed. The rotary operation bodies 30, 30 are connected to the movable side mounting plate 84, and other configurations including this are almost the same as those in the above-described embodiment. The elements having the same signs as those in the above-mentioned embodiment are the elements having the same or the same structure and function, and therefore the description thereof will be omitted.

[Effects of the Invention] As described above, according to the present invention, since a ring-shaped bearing is mounted along the outer periphery of the rotating piece, a large torque is not required at the time of rotation start, so the rotating torque of the rotating piece is large. Can be used for gate cutting without waste, and gate cutting can be made beautiful. In addition, even if the insertion clearance of the rotating piece exists, the rotation deviation can be suppressed to be small, so that the gate portion is not displaced even if the rotating piece rotates. Furthermore, the gate can be always returned to the same position by the positioning means. From these things, in the mold closed state, the cavity space and the gate part can always be in the same position without eccentricity, so the flow of the molten resin becomes smooth even if a rotating piece is used, and the molded product becomes defective. Has the effect of decreasing.

Further, by adopting the structure adopted by the present invention, manufacturing can be facilitated and equipment can be simplified.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of the main part of the resin molding die according to the first embodiment of the present invention. FIG. 2 is a sectional view of the mold closed state, and a front sectional view is shown in the left half. FIG. 3 is an enlarged side sectional view of a main part. FIG. 4 is a sectional view of the same gate cut state, and FIG. 5 is a sectional view of the mold open state, and a front sectional view is shown in the left half. FIG. 6 is a side sectional view of the second embodiment. FIG. 7 is a partially cutaway perspective view of the embodiment of FIG. FIG. 8 is a cross-sectional view of the mold closed state of FIG. 7, in which the left half is a side sectional view and the right half is a front sectional view. FIG. 9 is a partially cutaway sectional view of the fourth embodiment. 1 ... Fixed mold plate, 2 ... Movable mold plate, 3 ... Parting surface, 40,70,81 ... Storage hole, 5 ... Sprue, 7 ... Cavity space, 11,83 ... Sprue bush, 20 …… Rotating piece, 21 …… Cylindrical part, 22 …… Bill part, 25 …… Runner part, 26 …… Gate part, 27 …… Spiral groove, 30,71 …… Bearing, 33 …… Positioning means, 34 ...... Concave groove, 35 …… Click mechanism, 40,52 …… Rotating operation body, 43 …… Protrusion.

Claims (2)

(57) [Claims] 1. A rotating piece that is rotatable in the mold opening / closing direction in a closed state of the parting surface is mounted on one of the movable template and the fixed template, and the rotating piece is a parting surface. A mold for resin molding, in which a runner portion and a gate portion are provided on the end surface located at, the positioning means is provided on the outer surface, and a ring-shaped bearing is mounted along the outer circumference. 2. A rotating operation body engaged with an outer surface of a rotating piece, and a groove for moving the rotating operation body to rotate the rotating piece when any one of the mold plates is opened and closed. 1
Mold for resin molding.