JPH0732370A - Loose core ejector for resin mold - Google Patents

Abstract

PURPOSE:To form a large undercut without entirely generate a moment at a loose core when the core is raised and lowered in resin molds by relatively increasing its oblique angle and protruding stroke. CONSTITUTION:An ejector plate 16 is vertically movably disposed between a core 11b and a pedestal plate 13 disposed at an interval from its lower part, and a slide passage 22 is formed at the plate 16 by extending its lower end in a relatively laterally moving direction at the time of raising and lowering a loose core 18. A slide base 23 is movably disposed on the passage 22, a lower end of the core 18 is coupled, and a lower end 18c of the core is positively laterally moved by laterally moving force applying means 34 at the time of raising and lowering the plate 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loose core ejector device for a resin molding die, and more specifically, it penetrates a core forming one part of the resin molding die to form an undercut portion in the resin molding. , A device for moving a loose core that is installed obliquely with respect to its surface and movable in the longitudinal direction.

[0002]

2. Description of the Related Art Conventionally, a device for moving a loose core that obliquely penetrates a core forming one part of a resin molding die to form an undercut portion in a resin molded product and is movable in a longitudinal direction is an ejector device. And was constructed as shown in FIG.

That is, the conventional loose core ejector device includes a loose core 4 extending obliquely downward through the through holes 3 of a plurality of cores 2a constituting one part of the mold in the resin molding die 1. The through hole 3 is an angle setting hole 3a for setting an angle of the loose core 4 with respect to the core 2a and a passage 3 for penetrating the loose core 4 in a non-contact state.
b.

The upper end of the loose core 4 functions as a mold portion 4a for molding the resin molded product 5 in cooperation with the core 2, and the side surface thereof has a protruding portion for forming an undercut portion in the resin molded product 5. A groove portion 4b for forming is formed. A lower end portion 4c of the loose core 4 is connected to a movable body 6 called an ejector plate that is vertically movable below the core 2a and is spaced from the core 2a.

As shown in FIG. 11, the connecting structure of the lower end 4c of the loose core 4 and the ejector plate 6 is formed by closely contacting the upper plate 7a and the lower plate 7b, and the upper plate 7a has a convex cross section. Holes 8 are formed. The lower end of the loose core 4 is inserted into the hole 8, and the lower end surface of the loose core 4 is in contact with the lower plate 7b. Further, a pin 9 which extends across the lower end of the loose core 4 and is longer than the diameter of the small-diameter hole portion 8a is attached so as to be located in the large-diameter hole portion 8b.

In this loose core ejector device, when the resin molded product 5 molded by the resin molding mold 1 is removed from the mold 1, the mold which is one part of the mold 1 is first formed. The main body 2b is removed, and then the ejector plate 6 is lifted vertically upward. As a result, the loose core 4 is pushed up and lifted by the lower plate 7b with which the lower end surface is in contact.

However, as is apparent from FIG. 10, the loose core 4 is composed of a plurality of cores 2 constituting the resin molding die 1.
Since it passes through the loose core angle setting hole 3a formed in a, it is guided by this setting hole 3a and moves in its longitudinal direction. As a result, the upper and lower ends of the loose core 4 move laterally in position, whereby the protrusions integrally formed on the resin molded product 5 are relatively moved from the groove 4b of the mold portion 4a, which is the upper end of the loose core 4. Get out.

When the loose core 4 is returned to its original position again, the ejector plate 6 is lowered and the hole 8
The pin 9 is engaged with the inner step portion and pulled down vertically. As a result, a downward pulling force is applied to the lower end of the loose core 4 in the vertical downward direction. As a result, the loose core 4 moves in the longitudinal direction due to the regulation of the angle setting hole 3a of the core 2a, and is drawn to the original position.

[0009]

However, in such a conventional loose core ejector device, when the loose core 4 is returned to its original position after being lifted, the pin 9 and the ejector plate 6 attached to the lower end of the loose core 4 as described above. The lower end of the loose core 4 is pulled down vertically by the engagement with the stepped portion in the hole 8.

However, the loose core 4 has a core 2a.
When the downward pulling force in the vertical downward direction is applied to the lower end of the loose core 4 as described above, it is apparent from the configuration explanatory view of FIG. 12. As described above, a component force F in the lateral direction is generated, and this component force F acts as a bending force and a moment on the loose core 4.

When the loose core 4 is lifted, a similar component force is generated, but since the entire lower end face receives the lifting force in the vertical direction, the frictional force in the horizontal direction is small. However, when the loose core 4 is pulled back downward, the pin 9 and the stepped portion of the hole 8 come into line contact with each other, so that the generated lateral frictional force is relatively large, and therefore the bending force and the moment are not generated. It is remarkable. The difference between the bending force and the magnitude of the moment is that the force R ′ in the vertically upward direction at the time of rising is determined by the insertion hole 3
It is also clear that the force R on the inside of or near the slope 7 of a and on the vertical downward direction when descending acts on the outside of the slope 8.

As described above, the bending force and the moment generated in the loose core 4 during the movement generate a particularly large contact force with the portion indicated by P in FIG. 12 at the peripheral edge of the lower end opening of the insertion hole 3a, and as a result, the loose core 4 Also, the core 2a is subject to wear and fatigue. Therefore, in this conventional loose core ejector device, the durability of the loose core 4 and the core 2a cannot be obtained, and there is a problem that reliability is lacking.

Further, in the conventional loose core ejector device, since the problem as described above occurs, the inclination angle of the loose core 4 is set as upright as possible (about 10 degrees or less), and the loose core 4 has a protruding stroke. Was small (even if the inclination angle is the same, if the protruding stroke is large, the operating condition becomes worse). for that reason,
The amount of undercut that can be processed is naturally limited.

Various improved loose core ejector devices have been proposed in an attempt to solve the above conventional problems, but all of them have a basic structure, that is, a pulling force in a vertically downward direction at the lower end when the loose core is pulled back. There is no significant change in the structure for moving the loose core in the longitudinal direction by providing the above, and the problem described above has not been solved even though there is a difference in degree.

The object of the present invention is to solve the above-mentioned conventional problems. When the loose core is raised or lowered, no moment is generated in the loose core, and the inclination angle and the protruding stroke thereof are not generated. It is an object of the present invention to provide a loose core ejector device of a resin molding die capable of forming a relatively large size and forming a large undercut.

[0016]

The present invention is a loose core ejector device for a resin molding die, which has the following constitution in order to solve the above-mentioned technical problems. That is, according to the present invention, the core 11b, which is a constituent part of the resin molding die A, is formed so as to form an undercut portion in the resin molded product, and is installed obliquely with respect to the surface and movable in the longitudinal direction. In the ejector device 10 for moving the loose core 18, the ejector plate 16 arranged to be movable up and down between the core 11b and the pedestal plate 13 arranged at a lower portion of the loose core 18, and the loose core 18 rising and falling. Sometimes, a slide path 22 formed on the ejector plate 16 is extended at a lower end of the slide path 22, and the slide path 22 is movably arranged on the slide path 22.
It comprises a slide base 23 connected to the lower end of the loose core 18, and a means 34 for positively applying a lateral movement force to the lower end 18c of the loose core when the ejector plate 16 is moved up and down. And

Further, in the loose core ejector device of the resin molding die of the present invention, the ejector plate 16 is used.
Means 34 for positively applying a lateral movement force to the lower end portion 18c of the loose core when the core 11 moves up and down.
b and the pedestal plate 13 between the loose core 18
And a guide rod 25 extending in parallel with the slide base 23, one end of which is locked to the core 11b and the other end of which is locked to the pedestal plate 13. The slide base 23 is opposed to the guide rod 25. It is characterized in that it is slidably connected.

Further, in the loose core ejector device of the resin molding die of the present invention, the slide base 23 is provided with a guide bush 28 rotatably attached to the slide base 23, and the guide bush 28 is rotated. Insertion hole 28 formed along an axis orthogonal to the moving axis
The guide rod 25 is slidably inserted into a.

[0019]

According to the loose core ejector device for the resin molding die according to the present invention, when the ejector plate 16 is raised, the slide base 23 arranged in the slide path 22 formed on the ejector plate 16 is also raised. Loose core 1 whose lower end is connected to this slide base 23
A vertical upward movement force is applied to the position 8.

At this time, the loose core 18 is simultaneously given a lateral movement force by the means 34 for moving the lower end portion thereof in the lateral direction, so that the loose core 18 is combined with the ascending force given to the slide base 23, thereby This will result in an upward movement in the longitudinal direction. On the other hand, when the ejector plate 16 is lowered, a vertical downward pulling force is applied to the loose core lower end portion 18c via the slide base 23, and at the same time, the lateral movement direction at the time of rising is determined by the lateral movement means 34. A lateral movement force in the opposite direction is positively applied, and as a result, the loose core 18 is pulled down in its longitudinal direction by the resultant force.

Therefore, the loose core 18 does not generate a bending force and a moment when the loose core 18 is moved up and down, so that the loose core 18 does not rub against the end opening peripheral edge portion of the insertion hole 17 of the core 11b and is stable for a long time. Operation is guaranteed and extremely high reliability is obtained.

[0022]

EXAMPLES The loose core ejector device for a resin molding die according to the present invention will be described in more detail with reference to the examples shown in the drawings. FIG. 1 shows a loose core ejector device 10 for a resin molding die according to an embodiment of the present invention.

First, a resin molding die A equipped with the loose core ejector device 10 will be described. The overall shape of this resin molding die A is shown in FIG. 2, and the overall configuration is as follows: the core 11b is provided at the bottom of the die body 11a.
Are arranged, and a resin molding space 12 (FIG. 1) is defined by the mold body 11a and the core 11b.

A pedestal plate 13 is arranged below the core 11b, and the core 11b and the pedestal plate 13 are arranged.
The spacers 14 are arranged on both sides between the two, and thus a chamber 15 is formed between the spacers 14 below the core 11b. An ejector plate 16 is vertically movable in the chamber 15. 1 is shown in FIG.
2 is a partial view showing a state where the resin molding die A shown in FIG. 1 is broken along the line 1-1.

In this resin molding die A, the angle setting hole 17 (inclined) of the core 11b constituting the resin molding die A is formed to form an undercut portion in the resin molding formed in the resin molding space 12 described above. There is provided a loose core 18 which is inserted at an angle K), extends obliquely, and is movable in the longitudinal direction. The upper end of the loose core 18 functions as a mold part 18a for molding a resin molded product in cooperation with the core 11b,
A protrusion 18b for integrally forming an L-shaped flange portion (also a part of the undercut) on the resin molded product is formed on the side surface thereof.

The loose core 18 is fitted in a recess 19 formed in the lower surface of the core 11b, and a guide plate 21 fixed to the core 11b by a bolt 20 is inserted through a guide hole 21a formed obliquely to the core 11b. Extending downward. The entire guide plate 21 is shown in FIG. The guide plate 21 functions as a bearing because the loose core 18 can be smoothly slid in the longitudinal direction by the guide hole 21a formed at a predetermined inclination angle.

The loose core 18 as described above is formed by the loose core ejector device 10 by the angle setting hole 1 of the core 11b.
7 can be slid vertically. The loose-core ejector device 10 for this purpose comprises two plates 16a, 1
It includes an ejector plate 16 formed by stacking 6b. The upper plate 16a of the ejector plate 16 has a slide path 22 extending in the relative lateral movement direction of the lower end of the loose core 18 when the loose core 18 is raised and lowered.

A slide base 23 is slidably arranged on the slide path 22, and a lower end 18c of the loose core 18 is received in a recess 23a formed in the slide base 23 and fixed by a pin 24. The entire slide base 23 is shown in FIG.

Furthermore, the loose core ejector device 10
Is an angular guide rod (hereinafter simply referred to as a guide rod) 25 adjacent to and parallel to the loose core 18.
Are arranged. At both ends of this guide rod 25, V
A notch 26 having a shape is formed. The upper end portion of the guide rod 25 is supported by engaging a notch portion 26 with a pin 27 attached across the through opening 21b formed in the guide plate 21.

By the way, as shown in FIG. 4, the slide base 23 slidably provided on the ejector plate 16 has a U-shape when viewed in plan, on the side opposite to the recess 23a in the moving direction. The portion 23b is formed. A guide bush 28 is attached to the U-shaped portion 23b of the slide base 23 as shown in FIGS.

The guide rod 25, the upper end of which is supported and fixed to the guide plate 21, passes through the insertion hole 28a formed in the guide bush 28 attached to the slide base 23, and the escape formed in the lower plate 16b. It extends to the pedestal plate 13 through the hole 29, and the lower end portion thereof is supported and fixed by engaging the notch portion 26 with the pin 31 of the holder bush 30 attached to the pedestal plate 13.

As shown in FIG. 5, the holder bush 30 has forked portions 30a and 30b formed in the upper portion thereof, and a pin 31 is attached across the forked portions 30a and 30b. The holder bush 30 is inserted into the opening 32 formed in the pedestal plate 13 and is inserted into the bolt 33.
It is fixed by.

This guide rod 25 is used for the loose core 18
It has been described that the guide rods 25 are arranged in parallel with each other, that is, at the same inclination angle. (Spacer 14 height),
It depends on the lateral position of the pin 27 provided on the guide plate 21 and the pin 31 provided on the holder bush 30.

Next, the operation of the loose core ejector device 10 of the resin molding die A in this embodiment will be described. After molding the resin molded product with the main mold A, the ejector plate 16 is raised. When the ejector plate 16 rises, a vertically upward lifting force acts on the lower end of the loose core 18 via the slide base 23 arranged in the slide path 22 of the upper plate 16a.

However, since the guide bush 28 attached to the slide base 23 is slidably mounted on the guide rod 25, the slide base 23 rises and moves laterally along the guide rod 25 at the same time. It is forced to move in the direction. The lateral movement distance at this time is that the inclination angle of the guide rod 25 is equal to that of the loose core 1.
Since it is the same K degree as that of 8, when the vertical moving height of the slide base 23 is y, it becomes y / tank °.

As a result, the slide base 23 receives the upward and lateral movement forces at the same time and is forced to move in the direction along the guide rod 25. Therefore, the loose core 18 having the lower end portion 18c fixed to the slide base 23 is given a moving force in the longitudinal direction thereof, which causes friction with respect to the angle setting hole 17 of the core 11b. No bending force or moment is applied.

On the other hand, when the ejector plate 16 descends, the slide base 2 is moved in the opposite manner to the above-described ascending.
3 is forcibly moved along the guide rod 23,
As a result, the loose core 18 is given a pulling force in the longitudinal direction. As a result, the ejector plate 16
Bending force and moment are not generated in the loose core 18 even when is lowered, so that friction with the angle setting hole 17 can be completely avoided.

As is clear from such an operation, the slide base 23 slidably installed on the ejector plate 16 and the guide rod 25 installed at the same inclination angle as the loose core 18 include the ejector plate 16.
A means 34 for positively moving the lower end portion 18c of the loose core 18 in the lateral direction at the time of ascending and descending is constituted.

Next, the structure adopted for the ease of assembling this loose core ejector device will be described. The guide rod 25 is inserted into the escape hole 29 of the ejector plate 16 and the insertion hole 28 a of the guide bush 28 from the opening 32 for mounting the holder bush 30 in the pedestal plate 13 after the loose core 18 and the slide base 23 are arranged at predetermined positions. And the pin 27 of the guide plate 21 is inserted into the notch 26 at the upper end of the guide plate 21 for engagement.

As described above, the engagement between the notch 26 and the pin 27 at the upper end of the guide rod 25 causes no problem because the guide rod 25 is inserted along the longitudinal axis thereof, but at the lower end. Engagement of the notch 26 and the pin 31 of the holder bush 30 is somewhat difficult. The reason is as follows.

That is, the guide rod 25 is provisionally positioned at a predetermined inclination angle by inserting the upper end portion thereof into the lower surface side of the core 11b as described above. After that, the holder bush 30 is put into the opening 32 of the pedestal plate 13, and at this time, the pin 31 of the bush 30 is inserted into the notch 26 at the lower end of the guide rod 23 to support and fix the lower end of the rod 23. become.

However, as is apparent from the insertion state of the holder bush 30 into the opening 32 of the pedestal plate 13, the pin 31 attached to this bush 30 is shown.
Approaches toward the lower end surface of the inclined guide rod 25 as shown in FIG. 7 from vertically below.

Therefore, in order for the pin 31 to smoothly enter the V-shaped notch portion 26, the notch portion 26 has an angle between the central axis of the rod 25 in the longitudinal direction and the inclined surface on one side. Must be formed to be equal to or larger than the inclination angle K ° of.

Further, in the slide base 23, a guide bush 28 slidably connected to the guide rod 25 is, as shown in FIGS. 1 and 6, an outer side portion thereof which is orthogonal to the axis of the insertion hole 28a. If it is rotatably attached to the slide base 23 by a pin 35 provided on the axis, the slide base is used also for a loose core ejector device having a guide rod whose angle is different from that of this embodiment. Therefore, the applicable range can be expanded.

This means that if the slide base can be used, for example, only for the loose core ejector device 10 of one embodiment, it is not necessary to use the guide bush 28 as described above, and it is shown in FIG. It also means that a slide base 37 in which an inclined hole 36 for directly inserting the guide rod is formed as described above may be used. As shown in FIG. 8, as a method for connecting the loose core 18 and the slide base 37, a bolt 38 is inserted from the lower surface side of the slide base 37 to lower the lower end portion 18c of the loose core 18.
May be screwed on.

Furthermore, in the loose core ejector device of the above-described embodiment, the guide hole 21a is formed in the guide plate 21 so that the loose core 18 can be inserted therethrough. However, as in the guide plate 41 shown in FIG. The portion through which the 18 is inserted may be the groove 41a.
With this guide plate 41, the portion through which the loose core 18 is inserted at a predetermined inclination angle can be manufactured accurately and easily.

[0047]

As described above, according to the loose core ejector device for the resin molding die of the present invention, when the moving force in the longitudinal direction is applied to the loose cores which are arranged at an inclination, the loose core ejector device has a conventional structure. Unlike the structure that obtains the moving force in the longitudinal direction only by the component force of the lifting or pulling force that is exerted in the vertical direction, the lower end of the loose core is positively moved in the lateral direction when the ejector plate is raised and lowered, and lifted. The loose core is positively moved in the longitudinal direction by obtaining a combined force of the force and the lateral movement force.

Therefore, when the loose core is moved up and down, the bending force and the moment, which have been exerted conventionally, are not applied. Therefore, it is possible to prevent the loose core from rubbing against the edge of the insertion hole of the core, and to prevent the loose core from moving. It is possible to prevent the occurrence of wear and improve its reliability.

In addition, according to the loose core ejector device of the present invention, since the loose core directly receives the moving force in the longitudinal direction thereof as described above, even if the inclination angle or the protruding stroke is increased, the loose core is not rubbed against the insertion hole. There is no problem, and as a result, the degree of freedom in setting the loose core, and by extension, the degree of freedom in resin mold design and product design, that is, the degree of freedom obtained from the fact that the undercut amount can be made larger than before, is achieved. It also has an excellent effect of improving.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a loose core ejector device for a resin molding die according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the entire resin molding die including the loose core ejector device shown in FIG.

3 is a perspective view showing an entire guide plate that constitutes the loose core ejector device shown in FIG. 1. FIG.

4 is a perspective view showing the entire slide base that constitutes the loose core ejector device shown in FIG. 1. FIG.

5 is a perspective view showing an entire holder bush that constitutes the loose core ejector device shown in FIG. 1. FIG.

6 is a cross-sectional view of the loose core ejector device shown in FIG. 1 as viewed from the right side of FIG. 1 in which an angular guide rod is attached.

7 is a structural explanatory view showing an assembled state when the lower end portion of the angular guide rod is engaged with the pin of the holder bush in the loose core ejector device shown in FIG. 1. FIG.

FIG. 8 is a cross-sectional view showing a modified example of the guide base that constitutes the loose core ejector device according to the present invention.

FIG. 9 is a perspective view showing a modified example of the guide plate constituting the loose core ejector device according to the present invention.

FIG. 10 is a cross-sectional view showing a loose core ejector device used in a conventional resin molding die.

11 is a partial cross-sectional view of a conventional loose core ejector device taken along line 10-10 of FIG.

FIG. 12 is a schematic configuration explanatory view for explaining a state of a force exerted on the loose core when the loose core descends in the conventional loose core ejector device shown in FIG. 9.

[Explanation of Codes] 10 Loose core ejector device of resin molding die 11a Mold body 11b Core 12 Resin molding space 13 Pedestal plate 14 Spacer 15 Chamber 16 Ejector plate 16a Upper plate 16b Lower plate 17 Loose core insertion hole 18 Loose core 18a type part 18b Projection 18c Lower end 19 Recess 20 Bolt 21 Guide plate 21a Guide hole 21b Through opening 22 Sliding path 23 Slide base 23a Recess 23b U-shaped portion 24 Pin 25 Guide rod 26 Notch 27 pin 28 Guide bush 28a Insertion hole 29 Escape hole 30 Holder bush 30a Bifurcated part 30b Bifurcated part 31 Pin 32 Opening 33 Bolt 34 Loose core lower end lateral moving means 35 Pin 36 Tilt hole 37 Slide base 38 Bolt 41 guide plate 41a insertion groove

Claims (3)

[Claims] 1. A loose core, which penetrates a core which is a constituent part of a resin molding die to form an undercut portion in a resin molded product, and which is installed obliquely with respect to the surface and movable in the longitudinal direction. In the ejector device to
An ejector plate vertically movable between the core and a pedestal plate disposed at a lower portion of the core, and the lower end of the ejector plate extending in a relative lateral movement direction when the loose core is moved up and down. A sliding path formed on the ejector plate, a slide base movably arranged on the sliding path, and connected to a lower end of the loose core, and a lower end of the loose core positively when the ejector plate is moved up and down. A loose core ejector device for a resin molding die, comprising: a means for applying a lateral movement force. 2. Means for positively applying a lateral movement force to the lower end of the loose core when the ejector plate is raised and lowered is configured to move the slide base between the core and the pedestal plate in parallel with the loose core. A guide rod extending through the guide rod, one end of which is locked to the core and the other end of which is locked to the base plate, and the slide base is slidably connected to the guide rod. The loose core ejector device for the resin molding die according to claim 1. 3. The slide base includes a guide bush rotatably attached to the slide base, and the guide rod is inserted in an insertion hole formed along an axis orthogonal to a rotation axis of the guide bush. The loose core ejector device for the resin molding die according to claim 2, wherein the resin is inserted so as to be relatively slidable.