JPH07266344A - Molds - Google Patents

Abstract

PURPOSE:To provide molds in which a molded form having a protrusion can be preferably released without damaging the protrusion protruding in a direction for preventing releasing from the molds after molding. CONSTITUTION:The molds comprise an upper mold 13 for molding an upper surface of a molded form to be molded, a lower mold 23 for molding a lower surface of the form, and an auxiliary mold 31 contained in a hole 23a vertically passed through the mold 23 to advance or retract in a separating or touching direction of the molds 13 and 23 by vertical movement of a driving cylinder 35, wherein a molding position for molding a protrusion of the form is provided at a head 31c of the mold 31. The mold 31 is formed in a leaf spring shape to be bent at a specific angle toward a surface opposed to the surface provided with the molding position, and at the time of rising, it is reset to an original shape, while at the time of falling, in the case of engaging with the hole 23a, a pressing force is applied by the wall of the hole 23a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die, and more particularly to a resin molding having a protrusion protruding in a direction that prevents the molding from being released from the mold after molding. The present invention relates to a molding die capable of releasing a molded article such as a rubber molded article without any trouble.

[0002]

2. Description of the Related Art Generally, when molding a thermoplastic material such as synthetic resin or rubber into a product having a desired shape,
Use a molding die to inject molten resin into the cavity that is configured during mold clamping, or clamp a rubber material between the molds and clamp and heat to match the shape of the cavity. Manufacture products.

For example, in the injection molding of resin molded products,
Using a pair of dies that are arranged opposite to each other and are capable of contacting and separating from each other, a molten resin is injected and injected into a cavity formed when the two dies are clamped, and this cavity is A molded product having a shape matching the shape of the cavity is manufactured by curing the inside.

After the resin is cured, the two molds are separated from each other to open the mold, and the molded product remaining on one of the molds is removed from the mold. If the portion projects in a direction that prevents the molded product from being released, the molded product cannot be released, or the molded product is distorted and removed, which is not preferable.

Therefore, conventionally, an improvement has been added to the mold in order to release the molded product having the above-mentioned protrusion without any trouble.

For example, since the molded product X6 shown in FIG. 6 has a protrusion Y6 projecting inwardly on its inner surface, when molding is performed using a mold corresponding to the inner surface having such a shape, the molded product X6 is moved upward from the mold in the figure. Mold release in the direction is blocked by the protrusion Y6, and the molded product X6 must be distorted and removed.

Therefore, as shown in the drawing, an upper mold A6 which is a movable mold, a lower mold B6 which is a fixed mold and has no molding portion for molding the above-mentioned protrusion Y6, and a lower mold B6 are provided on the side surfaces of the lower mold B6. Slide type C6 that fits in the recess and slides laterally
It is known that the slide die C6 is provided with a molding portion for molding the protrusion Y6 by using and.

During molding, the upper mold A6 is lowered and clamped to move the slide mold C6 to the right through the guide portion D6 provided on the upper mold A6.
The protrusion forming portion of 6 is positioned at a predetermined position with respect to the lower mold B6, whereby the cavity for molding the molded product X6 having the protrusion Y6 has three molds A6, B.
6 and C6.

On the other hand, at the time of mold release, as shown in the figure, the upper mold A6
When the mold is lifted and the mold is opened, the slide mold C6 moves to the left, and as a result, a space is created in the inner surface of the inner surface where the molded protrusion Y6 projects, so that the molded product X6 can be separated from the lower mold B6 without any trouble. Can be molded.

Further, in the case of the molded product X7 shown in FIG. 7, two protrusions Y which hang down from the upper portion of the inner surface and project laterally
7 and Y7 'are the protrusions Y6 in the above-mentioned molded product X6.
Similarly to the above, the molded product X7 is prevented from being released from the mold for molding the protrusions Y7 and Y7 ′ in the upward direction.

Therefore, as shown in the figure, the upper mold A7 which is a movable mold, the lower mold B7 which is a fixed mold and has no molding portion for molding the above-mentioned protrusions Y7 and Y7 ', and the lower mold B7 are respectively provided. Two slide dies C7 and C7 'that fit in the holes penetrating at an inclination angle of and slide in the vertical direction;
Slide block D attached to the bottom of 7, C7 '
7, D7 'are housed so as to be slidable in the lateral direction, and the protrusions Y7 and Y7' corresponding to the slide molds C7 and C7 'are respectively used by using the driving member E7 which is driven in the vertical direction. It is also known to provide molding sites for molding.

In this case, the upper die A7 is lowered at the time of molding, and the driving member E7 is lowered until the upper surfaces of the slide dies C7 and C7 'are aligned with the convex surface of the lower die B7. Molds A7, B7, C7 and C
7'constitutes a cavity for molding the molded product X7 having the protrusions Y7, Y7 '.

After the resin is cured, the upper die A7 is raised to open the die as shown in the figure, and the driving member E7 is raised to push up the two slide dies C7 and C7 '.
The molded product X7 is released from the lower mold B7. At this time, since the slide molds C7 and C7 'are to be raised obliquely upward along the inclination of the through holes, they are naturally separated from the protrusions Y7 and Y7' and damage the protrusions Y7, Y7 '. The molded product X7 can be released from the mold.

[0014]

However, in the example shown in FIG. 6, the slide die C6 and the guide portion D6 are worn due to long-term use, and as a result, the positioning accuracy of the slide die C6 is deteriorated and the lower die B6 is used. Concave part and slide type C6
However, there is a problem that a gap is generated between the two and the resulting molded product has burrs. Further, since the slide die C6 is positioned indirectly through the guide portion D6 by the lowering of the upper die A6, there is a limit to the dimensional accuracy of the molded product. Further, for example, as shown by the chain line in FIG. 6, the protrusion Z6 that hangs from the upper surface of the molded product X6 in the inward direction of the molding surface of the protrusion Y6, in other words, in the direction in which the slide mold C6 moves during mold release. In the case of molding, the back surface of the slide die C6 must be thin, but the back surface of the slide die C6 must be thin.
Is also a portion for receiving the moving force in the lateral direction of the mold, and considering the strength of the mold C6, there is a limit to making it thinner, and when the protrusion Z6 is close to the molding surface of the protrusion Y6, this type of slide mold is used. C6 cannot be used.

On the other hand, in the example shown in FIG. 7, since the slide dies C7 and C7 'slide in the oblique direction along the inclination of the through hole as the drive member E7 moves up and down, each of these slide dies C7. , C7 'attached to the slide blocks D7, D7' move left and right inside the driving member E7, but the slide blocks D7, D7 'move to convert vertical movement into horizontal movement. May not be performed smoothly, and as a result, the vertical movement of the drive member E7 may be delayed, or excessive force may be applied to the slide molds C7, C7 ′ or the lower mold B7 to damage the mold itself.

Therefore, according to the present invention, when a synthetic resin, rubber, or the like is molded into a desired shape and then the mold is opened and the molded product is released from the mold, it is projected in a direction that prevents the release. A molding die capable of satisfactorily releasing a molded product having such a protrusion without damaging the protrusion, which has a small and simple movement movement of the die at the time of releasing, and is used for a long period of time. An object of the present invention is to provide a molding die capable of withstanding the temperature.

[0017]

That is, the invention according to claim 1 of the present application (hereinafter referred to as the "present invention") is a molded article having a protrusion protruding in a direction that prevents release from the mold. A mold for molding, which is provided with an upper mold and a lower mold which are arranged to face each other and can be brought into contact with each other, and an auxiliary mold for molding the protrusion of the molded article, and the auxiliary mold is
The upper mold is formed of a spring material and is provided in one of the upper mold and the lower mold so as to be able to move back and forth in the separating and contacting directions. When the mold is clamped, the upper mold is retracted while deforming into the one mold. And a lower mold, which constitutes a cavity for molding the molded product, and is configured to project from the inside of the one mold when the mold is opened and to separate from the protrusion of the molded product by its elastic restoring force. The present invention relates to a mold for molding.

[0018]

According to the present invention, three types of molds for molding a molded article having a protrusion for preventing the mold from being released from the mold,
That is, the upper mold, the lower mold and the auxiliary mold are provided.

Of these, the upper die and the lower die are disposed so as to face each other and can be brought into contact with each other, so that they can be contacted with each other when the mold is clamped or separated from each other when the mold is opened.

On the other hand, the auxiliary mold is a mold for molding the protrusions of the molded product, and is provided on either the upper mold or the lower mold so as to be movable back and forth in the direction in which they come in contact with or separate from each other. Therefore, when the upper mold and the lower mold are in contact with each other when the mold is clamped, the auxiliary mold can be retracted to form a cavity for molding the molded product together with the upper mold and the lower mold. A molten resin is injected and injected, or a rubber material is sandwiched, and then cured to form a resin molded product or a rubber molded product having the above-mentioned protrusion.

Further, since the auxiliary mold is made of a spring material and is deformed when retracting during the mold clamping, the auxiliary mold is retracted into one of the molds. The auxiliary mold is deformed under the stress.

When the upper mold and the lower mold separate from each other when the mold is opened, the auxiliary mold projects from the one mold and separates from the projection of the molded product by its elastic restoring force. Therefore, the stress is released by the auxiliary mold protruding from one of the molds, and the above-mentioned deformation disappears due to the elastic restoring force of the spring material itself.As a result, the protrusion of the molded product separates from the auxiliary mold when the mold is opened. Will be typed.

Therefore, it becomes possible to release the molded product from the mold without damaging the protrusion.

[0024]

Embodiments of the present invention will now be described with reference to the drawings. In FIGS. 1, 4 and 5, the auxiliary mold 31, which is a characteristic part of the present application, is shown in a slightly enlarged manner in view of the drawings.

As shown in FIG. 1, the injection molding machine in this embodiment has an upper mold unit 10 and a lower mold unit 20 which are arranged to face each other, and an auxiliary mold unit which is vertically driven inside the lower mold unit 20. 30 and 30.

The upper die unit 10 has an upper die 1 in which a mating surface 11 is provided with a recess 12 which constitutes a cavity.
3 is attached to the support board 14, and the support board 14
The upper mold unit 10 as a whole is driven up and down by a cylinder (not shown) provided in the upper part of the above, and is brought into contact with or separated from the lower mold unit 20.

The lower mold unit 20 has a mating surface 21.
A lower mold 23 having a convex portion 22 forming a cavity is attached to a support board 24, and the support board 24 is attached to the side wall 2
It is configured to be fixedly mounted on a fixed base 26 via 5, 25, and a molten resin injection nozzle 2 is provided on the back of the lower mold 23.
7, 27 'are provided, and an injection passage 28 communicating from the nozzle 27, 27' to the convex surface 22a of the lower mold 23 is provided,
The injection gate 28a at the tip is exposed to the center of the convex surface 22a. Further, the lower mold 23 and the support board 2
Two holes 23a, 23a and 24a, 24a each having a quadrangular cross-section are formed so as to pass through each other in the vertical direction so that the axial centers in the vertical direction are aligned with each other. The support board 24
The holes 24a and 24a provided in the lower mold 23 have larger cross-sectional dimensions than the holes 23a and 23a provided in the lower mold 23.

On the other hand, the auxiliary mold unit 30 includes two auxiliary molds 31 and 31 respectively housed in the pair of upper and lower holes 23a, 24a and 23a, 24a, and a circular hole 31a provided in the lower part of the auxiliary mold 31. A support plate 33 for supporting the auxiliary mold 31 by a pin 32 penetrating the support plate 3 and the support plate 3
3 and a supporting board 34 for supporting the auxiliary molds 31 and 31 so as not to fall downward. The auxiliary mold unit 30 is a fixed supporting board 24 of the lower mold unit 20 and side walls. 25, 25 and fixed base 26
It is housed in an internal space 29 surrounded by. Further, a cylinder 35 for driving the auxiliary type unit which penetrates the fixed base 26 is provided on the back surface of the support board 34, and the vertical movement of the cylinder 35 causes the auxiliary type unit 30 to move up and down in the internal space 29. Driven in the direction.

At this time, as shown in the figure, when the support plate 34 contacts the fixed base 26 and the auxiliary mold unit 30 is lowered most, the upper surfaces of the auxiliary molds 31 and 31 become the convex surface 22a of the lower mold 23. The lengths of the respective constituent members in the vertical direction are set so as to coincide with each other. In addition, the holes 33a and 33a of the support plate 33, through which the lower parts of the auxiliary molds 31 and 31 penetrate, are formed by
4 as well as the holes 24a, 24a provided in the lower mold 23, the sectional size of the holes 23a, 23a provided in the lower mold 23 or the auxiliary mold 3
It is set larger than the cross-sectional dimensions of 1, 31.

Here, the auxiliary mold 31 is made of a metal material generally used for a resin molding die, and has a rectangular cross section and a vertical shape as shown in the right side view and front view of FIGS. 2 and 3, respectively. It is a long rod. The thickness of the intermediate portion 31b is reduced, and the intermediate portion 31b is bent from the predetermined portion of the intermediate portion 31b to the right in FIG. The whole 31 has a function as a leaf spring.

Therefore, even if a lateral stress acts on the auxiliary die 31 in FIG. 2, when the stress is released, the auxiliary die 31 returns to the original shape shown in FIG. 2 having the bending angle θ. It will be.

The lower part of the auxiliary die 31 is provided with the above-mentioned round hole 31a penetrating from the front surface to the back surface, and the auxiliary die 31 is supported by the support plate 33 by a pin 32 penetrating the round hole 31a. In addition, a molding portion 31d forming a cavity is provided on the front surface of the head portion 31c in a shape curving in the back direction.

A hole 23a provided in the lower mold 23
Has a quadrangular shape having substantially the same size as the cross-sectional dimension of the head 31c so that the head 31c can be fitted without a gap when the auxiliary mold 31 descends.

Therefore, when the auxiliary mold 31 is lowered as shown in FIG. 1 and the head 31c of the auxiliary mold 31 is fitted into the hole 23a, the stress that presses the head 31c from the back surface to the front surface is applied to the hole. Will be added by the side wall of 23a,
The lateral stress described above acts on the auxiliary mold 31.

On the other hand, when the auxiliary die unit 30 is moved upward by driving the auxiliary die unit 30, the head portion 31c is pushed out of the hole 23a.
The stress due to the side wall of a is released, and the auxiliary mold 31 returns to the original shape having the bending angle θ again. At this time, since the lower portion of the auxiliary mold 31 is fixed by the support plate 33, the head 31c moves rearward by the bending angle θ from the position when the head 31c was housed in the hole 23a.

As shown in FIG. 1, the two auxiliary molds 31, 31 in this embodiment are provided with their rear surfaces opposed to each other, and when the stress is released, the auxiliary mold 3 on the left side in the figure is provided.
The heads 31c and 31c of the auxiliary mold 31 on the right side of FIG.

Next, the operation of this embodiment will be described with reference to FIGS. 4 and 5. First, when the mold is clamped, as shown in FIG. 4, the convex portion 22 of the lower mold 23, which is the fixed mold, is the movable mold. Entering the concave portion 12 of the mold 13, the mating surface 1 of both molds 13 and 23
The upper mold unit 10 is lowered until the 1, 21 are in close contact with each other, and the auxiliary mold unit 30 is lowered until the supporting plate 34 thereof comes into contact with the fixed base 26 of the lower mold unit 20.

Here, the supporting plate 33 of the auxiliary type unit 30.
Since the auxiliary mold 31 which is attached so as to project upward from the lower part of the auxiliary mold 31 is fixed to the supporting plate 33 by the pin 32, the head 31c originally has a shape bent rightward in the figure by an angle θ. As the auxiliary mold unit 30 descends, the auxiliary mold unit 30 is pulled down in the holes 23a and 24a of the lower mold unit 20, and the head 31c is fitted into the hole 23a of the lower mold 23 without any gap. The whole extends in a straight line in the axial direction of the holes 23a, 24a.

At this time, the wall surface on the right side of the hole 23a in the drawing presses the surface of the auxiliary mold 31 in the bending direction, that is, the rear surface, in the front direction, and the auxiliary mold 31 is lowered while receiving the pressing force. It will be. Here, in the intermediate portion 31b where the thickness of the auxiliary mold 31 is reduced below the head portion 31c, if the wall thickness is cut so as to be smoothly curved on the back surface side that receives the pressing force, the auxiliary mold 31 is reduced. Is preferable because it can be smoothly lowered.

Further, by setting the cross-sectional size of both the hole 24a and the hole 33a of the support plate 33 to be larger than the cross-sectional size of the hole 23a in which the head 31c is fitted without a gap, the head 31c is Since the intermediate portion 31b or the lower portion of the auxiliary mold 31 can freely move in the left-right direction in the drawing as a reaction force when receiving the pressing force, the descending can be smoothly performed while receiving the pressing force. .

Here, a cavity is formed by the concave portion 12 of the upper die 13, the convex portion 22 of the lower die 23, and the molding portion 31d of the auxiliary die 31, and the molten resin is injected from the injection gate 28a through the injection passage 28 described above. By injecting and hardening it, a molded product X having a shape of the cavity can be obtained.

Since the molded product X obtained at this time is molded in a shape that matches the molded portion 31d that is curved to the right in the figure, it has a protruding portion Y that protrudes in the back direction of the auxiliary mold 31. This means that the projection Y prevents the molded product X from being released from the mold.

Next, when the mold is opened, as shown in FIG. 5, the upper mold unit 10 is raised to separate the upper mold 13 from the lower mold 23, and then the auxiliary mold unit 30 is raised to a predetermined position.

As described above, in this molding machine, since the molten resin is injected and injected from the lower mold 23 side, the cured molded product X remains in the lower mold 23. Then, first, the upper mold unit 10 is lifted to form a space above the lower mold 23 for releasing the molded product X, and then the auxiliary mold unit 30 is lifted to direct the auxiliary mold 31 to the space. Push it up. As a result, the molded product X remaining in the lower mold 23 is pushed upward by the auxiliary mold 31 and released from the lower mold 23 without bearing.

Further, as described above, since the auxiliary mold 31 is originally bent in the right direction in the drawing by the angle θ and has a function similar to that of a leaf spring having elasticity, its head portion 31c is lifted. When it is pushed out from the hole 23a and the pressing force is released, the shape returns to the original shape, and as a result, the head 31c moves to the right in the figure.
That is, the head 31c or the auxiliary mold 31 is separated from the protrusion Y, and the molded product X can be released from the auxiliary mold 31 without damaging the protrusion Y.

Further, at the time of this mold release, the head 31c of the auxiliary mold 31 is pushed out toward the space formed above the lower mold 23, so that when it moves away from the protrusion Y, its rear surface. Does not collide with any member. Therefore, the slide type C6 shown in FIG.
In the above, the thickness of the back surface portion could not be reduced from the viewpoint of strength and the like, and as a result, the protrusion Z6 could not be formed in the vicinity of the protrusion, but in the auxiliary mold 31 of the present invention, the thickness of the head portion 31c of the auxiliary mold 31. Because it is possible to thin
In addition, as described above, since the auxiliary mold 31 is designed to have a function as a leaf spring, the overall thickness is reduced, so that the protrusion Z as shown in FIGS. In addition, the back surface of the auxiliary mold head 31c does not press the protruding portion Z even when the mold is released.

As described above, the two auxiliary molds 31,
31 is provided in the opposite direction, the molded product X having the two inwardly projecting projections Y, Y can be favorably released from the mold, and the auxiliary mold 31 is simply used. Since the mold is moved up and down, the movement of the mold is easy, and the work is smooth and reliable. Also,
Since there are few wear parts in the mold, it can withstand long-term use, and there is no problem such as positional deviation and deterioration of dimensional accuracy. Further, since the thickness of the auxiliary mold 31 can be reduced, another protrusion can be provided in close proximity, and the protrusion is not damaged at the time of mold release.

Although the molded product X remains in the lower mold 23 in this embodiment, the molded product X remains in the concave portion 12 of the upper mold 13 and the upper mold unit 10 rises when the mold is opened. In the case where the upper mold unit 10 and the auxiliary mold unit 30 are simultaneously raised at the same speed in the case where they are raised together with the upper mold 13, the molded product X is released from the lower mold 23 without any trouble and the protrusion Y is formed. It is possible to remove from the auxiliary mold 31 and perform good mold release.

Further, the protrusion forming portion 31d of the auxiliary mold 31
By providing the auxiliary mold 31 on the surface facing the bending direction, the auxiliary mold 31 is separated from the protrusion Y without damaging the protrusion Y.

Further, the bending angle θ is set on the basis of the protruding length of the protruding portion Y to be molded, and the bending angle θ is increased as the protruding length is increased, so that the bending angle θ from the protruding portion Y of the auxiliary mold 31 is increased. Separation becomes reliable, and good mold release can be performed.

In the above embodiment, the case of resin molding by injection molding is shown, but not limited to this, when a rubber material is sandwiched and clamped, and heating and releasing are performed to manufacture a rubber molded product, etc. It can be used as a mold widely used for general molding.

[0052]

As described above, according to the present invention,
An auxiliary mold that includes an upper mold, a lower mold, and an auxiliary mold, and that molds the protrusion even when a molded product having a protrusion that prevents release from the mold is molded by these three molds. By driving itself, the molded product can be released from the mold without any trouble.

Further, the auxiliary mold is made of a spring material, and when the mold is opened, the stress is released to return to the original shape, so that the auxiliary mold is separated from the above-mentioned protrusion. Can be released.

Further, since the auxiliary type moving operation is simple, smooth and reliable work is guaranteed, and it is possible to endure long-term use.

Since the thickness of the auxiliary mold is thin and the moving distance is short, another protrusion can be formed close to the protrusion, and the molded product can be released from the protrusion without damaging the protrusion. Is possible.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a resin molding machine equipped with a molding die according to an embodiment of the present invention.

FIG. 2 is a right side view showing an auxiliary mold in the above embodiment.

FIG. 3 is a front view of the auxiliary mold.

FIG. 4 is an enlarged sectional view of a main part of the molding machine.

FIG. 5 is an enlarged cross-sectional view of an essential part of the molding machine.

FIG. 6 is an explanatory diagram of a problem that a conventional molding die has.

FIG. 7 is an explanatory diagram of a problem that another conventional molding die has.

[Explanation of symbols]

 10 Upper mold unit 13 Upper mold 20 Lower mold unit 23 Lower mold 23a, 24a Hole 30 Auxiliary unit 31 Auxiliary mold 31c Auxiliary mold head 31d Projection part molding part 33 Bearing plate 35 Auxiliary unit drive cylinder

Claims (1)

[Claims] 1. A mold for molding a molded article having a protrusion projecting in a direction for preventing the mold from being separated from the mold, and an upper mold and a lower mold which are arranged to face each other and can be contacted and separated from each other. , An auxiliary mold for molding the protrusion of the molded product is provided, and the auxiliary mold is formed of a spring material and is provided in either one of the upper mold and the lower mold in the direction of separation and contact thereof. It is provided so that it can move forward and backward, and when it is clamped, it retreats while deforming into the one mold and forms a cavity for molding the molded product together with the upper mold and the lower mold.When the mold is opened, it projects from the one mold. A molding die, which is configured to separate from a protrusion of a molded product by its own elastic restoring force.