JPH0732425A - Molding die - Google Patents

Abstract

PURPOSE:To lower a cost, raise a dimensional accuracy of a molded product, and prevent a fatigue failure of a component part of an inclinedly sliding mechanism with respect to a molding die for producing a molded product having an undercut part erected inclinedly to a mold opening/closing direction. CONSTITUTION:When a mold closing force is released after highpressure injection of a melt resin, first mold parts 1, 2, 6 are parted from second mold parts 3, 7 at a parting face PL1. Simultaneously, the second mold parts 3, 7 are parted from third mold parts 4, 5, 10 at a parting face PL2 by a pressing force of contacting/separating means 13, 14. The separation allows an inclined core 9 to move in a direction of an arrow 12. The inclined core 9 moves by a pressing force of a pressing means 11. Therefore, simultaneously with a mold opening, a mold part provided on one end of the inclined core 9 can be inclinedly removed from an undercut part 8a of a molded product 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die for producing a molding product having an undercut portion which is inclined in an opening / closing direction.

In recent years, a mold die has been proposed in which an ejecting problem does not occur even if it has an undercut portion by an inclined slide mechanism that moves a part of the die obliquely to the die opening direction when the die is opened. Being developed. The undercut portion is a shape portion of a product that cannot be ejected from the mold as it is.

[0003]

2. Description of the Related Art FIG. 6 is a sectional view showing a schematic structure of a conventional molding die. In the figure, reference numeral 101 is a fixed side mounting plate, 102 is a movable side mounting plate, 103 is a locate ring,
104 is a cavity support plate, 105 is a core support plate, 10
6 is a receiving plate, 107 is a spacer block, 108 is a sprue bush, 109 is an ejector pin, 110 is an ejector plate upper plate, 111 is an ejector plate lower plate,
112 is a return pin, 113 is a cavity block,
Reference numeral 114 is a core block, 115 is a guide pin, and 116 is a guide pin bush.

Of the above, the fixed side mounting plate 101, the locate ring 103, the cavity support plate 104, the sprue bush 108, the cavity block 113, and the guide pin bush 116 constitute the fixed side mold, and the rest are the moving side molds. Make up. The boundary surface between both molds is a parting surface (mold opening surface).

When the fixed mold and the movable mold are in contact with each other and the mold is closed, the molten resin is injected into the space between the molds through the sprue portion 117 and the gate portion 118.
A molded product 119 is manufactured. Reference numeral 120 is an undercut portion of the molded product 119.

The undercut portion 120 is engaged with one end of an inclined core 125 which constitutes a part of the mold. The inclined core 125 is movably supported by the core block 114 and moves in an oblique direction with respect to the mold opening / closing direction. One end of the slide cam 124 is slidably engaged with the other end of the inclined core 125. A cam surface is formed on the contact surface between the other end of the inclined core 125 and the one end of the slide cam 124. One end of a slide core 123 is fixed to the other end of the slide cam 124, and the slide core 123 is held by a cavity support plate 104 and a core support plate 105 so as to be slidable in a direction perpendicular to the mold opening / closing direction. One end of the angular pin 121 is slidably engaged with the slide core 123. The angular pin 121 has a rod shape extending obliquely with respect to the mold opening / closing direction, and the other end is fixed to the fixed side mounting plate 101. Slide core 123
A cam surface is formed on the contact surface between the and the one end side of the angular pin 121. A cam surface is formed at the other end of the slide core 123, and a cam surface formed at the other end of the locking block 122, one end of which is fixed to the fixed side mounting plate 101, is formed at the other end of the slide core 123. Engage a face. These inclined core 125 and slide cam 1
24, the slide core 123, the angular pin 121, and the locking block 122 constitute an inclined slide mechanism.

FIG. 7 is an enlarged view of this tilt slide mechanism portion. The operation of the tilt slide mechanism portion will be described with reference to this figure. Although the fixed side mold does not actually move when opening and closing the mold, the movement of the moving side mold is relative to the fixed side mold, and as long as both molds are considered, the moving side mold is not moved. There is no problem in thinking that the fixed side mold moves with respect to the mold. In the following explanation of operation, for convenience of explanation,
The description will be made assuming that the fixed-side mold, that is, the fixed-side mounting plate 101 moves to the right in the drawing when the mold is opened.

After the molten resin is injected in the mold closed state shown in FIG. 7, the mold is opened and the fixed side mounting plate 101 moves to the right in the figure (direction of arrow 126). With this movement, the angular pin 1 fixed to the fixed side mounting plate 101
21 and the locking block 122 move in the direction of arrow 126. With the movement of the angular pin 121, the slide core 123 engaged with the cam surface moves in the arrow 127 direction. Therefore, the slide cam 124 that moves integrally with the slide core 123 also moves in the direction of the arrow 127. With the movement of the slide cam 124, the inclined core 125 engaged with the cam surface moves in the arrow 128 direction. As a result, simultaneously with the mold opening, the mold part provided at one end of the inclined core 125 is removed from the undercut part 120 of the molded product 119 in the direction of arrow 128.

On the other hand, when the mold is closed, the fixed side mounting plate 101
Moves to the left in the figure (the direction opposite to arrow 126). With this movement, the angular pin 121 and the locking block 122 move in the direction opposite to the arrow 126, and the slide core 123 moves with the movement of the angular pin 121.
Moves in the direction opposite to arrow 127. Therefore, the slide cam 124 that moves integrally with the slide core 123 also moves in the direction opposite to the arrow 127. This slide cam 1
With the movement of 24, the inclined core 125 moves in the direction opposite to the arrow 128. As a result, the mold part provided at one end of the inclined core 125 is moved to a predetermined position, and is ready for injection of the molten resin. It should be noted that the locking block 122 moves in the direction opposite to the arrow 126 and reaches the position shown in FIG. 7, whereby the return of the slide core 123 in the direction of the arrow 127 is suppressed, so that the inclined core accompanying the high-pressure injection of the molten resin is suppressed. The return of 125 in the direction of arrow 128 is suppressed.

[0010]

However, in the conventional molding die, the structure of the tilt slide mechanism portion is complicated, so that the number of parts is increased and the structure of each individual part is also complicated. There is a problem that the die manufacturing cost becomes relatively high because of the adjustment man-hours required for the tilt slide mechanism portion.

Further, as shown in FIG. 8, when the molten resin is injected at a high pressure, the inclined core 125 receives a strong molding pressure P (for example, 300 to 400 kgf / cm ² ) in the direction of the arrow 128, but the inclined core 125 slides. It is only held by 124. That is, at the end opposite to the mold portion of the inclined core 125 (the left end of the inclined core 125 in the figure), there is nothing to abut in order to secure a moving space. Therefore, the slide cam 124 receives a repeated load F (for example, 300 tons f every 50 seconds) from the inclined core 125 each time the molten resin is injected with high pressure. As a result, the deflection ε is generated in the slide cam 124.

Due to the occurrence of this deflection ε, the inclined core 12
5 retreats from the predetermined position in the direction of arrow 128, and as a result, the t dimension (plate thickness) and h dimension (boss height) of the molded product 119 determined by the inclined core 125 and the cavity block 113 vary in the positive direction. become. Further, a concentrated stress σ is generated in the bent portion of the slide cam 124,
As a result, a crack C is generated, and there is a risk that the slide cam 124 may be damaged by fatigue.

The present invention has been made in view of the above points, and is provided with a tilt slide mechanism for reducing the cost, improving the dimensional accuracy of the molded product, and preventing fatigue damage of the tilt slide mechanism components. It is an object of the present invention to provide a molding die.

[0014]

In the present invention, in order to achieve the above object, as shown in FIG. 1, a first mold part (1, 2, 6) located on one side of a molded product 8, A second mold part (3, 7) located on the other side of the molded product 8 and for joining and separating from each other with respect to the first mold part (1, 2, 6).
And a third mold part (4, 5, 1) movable in the mold opening / closing direction.
0), the first die part (1, 2, 6) and the second die part (3, 3
7) and the third mold part (4,5,1)
0) for separating and approaching the second mold part (3, 7) to and from the second mold part (3, 7) and a mold whose one end engages with the undercut part 8a of the molded product 8, The mold part (3, 7) is movably supported, and the other end is a third part.
Inclined core 9 arranged at a position where it abuts against the mold part (10) of
And the inclined core 9 to the undercut portion 8a of the molded product 8.
And a biasing means 11 for constantly biasing in the direction of coming into contact with the third mold part (10).

Further, as shown in FIG. 4, the molded product 2
8 and a first die part (21, 22, 26, 33) having a first cam surface and a second die part (21, 22, 26, 33) located on the other side of the molded product 28. 22, 26, 33)
To the second mold part (23,
24, 27) and a second mold part (23) movably supported in a direction perpendicular to the mold opening / closing direction, and the first mold part (3
3) A slide cam means 34 having a second cam surface that engages with the first cam surface and a third cam surface at the other end, and one end that engages with the undercut portion 28a of the molded product 28. And the slide cam means 34 and the inclined core 29 that is movably supported by the second die part (27) and has the other end engaged with the third cam surface of the slide cam means 34. First urging means 35 which is provided between the second mold part (23) and urges the slide cam means 34 in a direction of abutting the first cam surface of the first mold part (33). Second urging means 31 provided between the inclined core 29 and the second mold part (27) for urging the inclined core 29 in a direction in which the inclined core 29 is always in contact with the third cam surface of the slide cam means 34; Equipped with.

[0016]

With the above construction, in FIG. 1, when the mold closing force is released after the molten resin is injected at a high pressure, the first mold part (1, 2, 6) and the second mold part are released. At the same time as (3, 7) is separated on the parting surface PL1, the approach separation means (1
The third mold part (3, 7) and the third mold part
The mold parts (4, 5, 10) are separated by the parting surface PL2. Due to this separation, the inclined core 9 becomes movable in the direction of the arrow 12 and is moved by the urging force of the urging means 11. Therefore, at the same time when the mold is opened, the mold part provided at one end of the inclined core 9 is moved to the undercut part 8a of the molded product 8.
The mold will be cut diagonally from.

Further, in FIG. 4, when the mold closing force is released after the molten resin is injected at high pressure, the first mold part (21,
22, 26, 33) and the second mold part (23, 24, 27)
And are separated. Due to this separation, the slide cam means 34 abutting on the first cam surface of the first die part (33) moves in the direction of arrow 36 by the urging force of the first urging means 35, and in conjunction with this, The inclined core 29 moves in the direction of arrow 32 by the urging force of the second urging means 31. Therefore, at the same time when the mold is opened, the mold part provided at one end of the inclined core 29 is removed from the undercut part 28 a of the molded product 28 in an oblique direction.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an inclined slide mechanism of a molding die of the first embodiment, FIG. 1 shows a mold closed state, and FIG. 2 shows a mold opened state. In the figure, reference numeral 1 is a fixed side mounting plate, 2
Is a cavity support plate, 3 is a core support plate, 4 is a receiving plate, 5 is a spacer block, 6 is a cavity block, 7 is a core block, and 8 is a molded product. Of these, the fixed-side mounting plate 1, the cavity support plate 2, and the cavity block 6 form a fixed-side mold, and PL1 serves as a parting surface. Further, as will be described later, the core support plate 3 and the receiving plate 4 are not in a fixed relationship as in the conventional case, and the link pin 13
Are separated in the mold opening direction, and there is another parting surface PL2 between them.

The undercut portion 8 of the molded product 8
One end of a tilted core 9 forming a part of the mold is engaged with a. The inclined core 9 is movably supported by the core block 7 and the core support plate 3, and moves in an oblique direction with respect to the mold opening / closing direction. The other end of the inclined core 9 has a flat surface inclined with respect to the axial direction of the inclined core 9. A flat inclined core holding plate 10 is provided on the receiving plate 4. The tilted core holding plate 10 is provided at a position where the other end of the tilted core 9 abuts regardless of the moving position of the tilted core 9. A spring 11 is provided between the flange portion 9a of the inclined core 9 and the core block 7, and the biasing force of the spring 11 causes
The tilted core 9 is always biased in the direction of the arrow 12 and is in contact with the tilted core holding plate 10.

A link pin 13 is held on the core supporting plate 3 and the receiving plate 4 slidably in the mold opening / closing direction. Collar-shaped stopper portions 13a and 13b are provided at both ends of the link pin 13, and these stopper portions 13a and 13b are separated from each other when the core support plate 3 and the receiving plate 4 are separated as described later. The stroke is stopped at the predetermined stroke amount S1.
A spring 14 is provided at the center of the link pin 13 between the core support plate 3 and the receiving plate 4. The spring 14 constantly biases the core support plate 3 and the receiving plate 4 in the direction of separating them. Although not shown in the figure,
Also in the upper part of the figure, the same components as the link pin 13 and the spring 14 are present in pairs.

Next, the operation of the tilt slide mechanism constructed as described above will be described. In the following description of the operation, for convenience of explanation, it is assumed that the fixed-side mold, that is, the fixed-side mounting plate 1 moves to the right in the drawing when the mold is opened.

After the molten resin is injected in the mold closed state shown in FIG. 1, the mold is opened and the mold closing force is released. As a result, as shown in FIG. 2, the fixed side mounting plate 1, the cavity supporting plate 2, and the cavity block 6 move to the right in the figure, and the urging force of the spring 14 causes the core supporting plate 3 and the receiving plate to move. 4 and 4 are separated by a predetermined stroke amount S1 along the link pin 13. As a result of this separation, the other end of the tilted core 9 becomes free, so that the tilted core 9 is tilted in the direction of the arrow 12 by the biasing force of the spring 11 to move the tilted amount S2.
The mold part provided at one end of the inclined core 9 is removed from the undercut part 8a of the molded product 8 by moving only.
That is, the undercut portion 8a is also punched at the same time when the die is opened.

On the other hand, the mold closing operation is the opposite of the above mold opening operation. When the mold is closed as shown in FIG. 1, the other end of the tilted core 9 is in contact with the tilted core holding plate 10, so that the tilted core 9 is in the direction of the arrow 12 accompanying the high-pressure injection of the molten resin. It does not return even if it receives the power to.

FIG. 3 is a diagram showing a molding process using a molding die having such an inclined slide mechanism. P1 to P5 in the figure represent process numbers. That is, the mold die is closed, and at the same time, the tilt slide mechanism operates to move the mold part provided at one end of the tilt core 9 forward to a predetermined position of the undercut part 8a (P1).

Molten resin is injected into the mold,
As it is, pressure is maintained to increase the density of the molten resin (P
2). The mold is cooled with water or the like at a predetermined temperature, and the resin material to be injected is weighed in preparation for the next injection of the molten resin in the apparatus for supplying the molten resin (P
3).

The mold is opened, the tilt slide mechanism is operated at the same time, and the mold part provided at one end of the tilt core 9 is moved backward from the undercut part 8a in an oblique direction to remove the mold ( P4).

The molded product 8 is ejected by the ejection of an eject pin (not shown) (P5). Then, the process returns to process P1.

4 and 5 are views showing an inclined slide mechanism of the molding die of the second embodiment. FIG. 4 shows the mold closed state and FIG. 5 shows the mold opened state. The second embodiment separates the receiving plate 4 and the core support plate 3 from each other by separating the receiving plate 4 and the core supporting plate 3 as in the first embodiment because of the structure of the mold (securing the eject stroke, constraint of the die height, securing the cooling water route, etc.). Surface PL
This is an effective embodiment when it is impossible to provide 2.

In the figure, reference numeral 21 is a fixed side mounting plate, 22 is a cavity supporting plate, 23 is a core supporting plate, 24 is a receiving plate, and 26 is a receiving plate.
Is a cavity block, 27 is a core block, and 28 is a molded product. Of these, the fixed side mounting plate 21,
The cavity support plate 22, the cavity block 26, and a slide cam 33, which will be described later, constitute a fixed-side mold, and PL
3 is the parting surface.

The undercut portion 28a of the molded product 28 is engaged with one end of an inclined core 29 forming a part of the mold. The inclined core 29 is movably supported by the core block 27 and moves in an oblique direction with respect to the mold opening / closing direction. A cam surface is formed on the other end of the inclined core 29.
A spring 31 is provided between the flange portion 29a of the tilted core 29 and the core block 27, and the biasing force of the spring 31 constantly biases the tilted core 29 in the direction of the arrow 32.

The other end of the slide cam 33 having a cam surface at one end is fixed to the fixed side mounting plate 21. Also,
The core support plate 23 holds a slide cam 34 slidably in the vertical direction of FIG. Cam surfaces are provided at both ends of the slide cam 34. One cam surface is constantly engaged with the cam surface at the other end of the inclined core 29, and the other cam surface is engaged with the cam surface at one end of the slide cam 33. Is arranged to get. A spring 35 is provided between the slide cam 34 and the core support plate 23.
Always biases the slide cam 34 in the direction of arrow 36.

Next, the operation of the tilt slide mechanism of the second embodiment constructed as described above will be explained. In the following description of the operation, for convenience of explanation, it is assumed that the fixed-side mold, that is, the fixed-side mounting plate 21 moves rightward in the drawing when the mold is opened.

After the molten resin is injected in the mold closed state shown in FIG. 4, the mold is opened and the mold closing force is released. As a result, as shown in FIG. 5, the fixed-side mounting plate 21, the cavity support plate 22, the cavity block 26, and the slide cam 33 move to the right in the figure, and the slide cam 33 moves to the right in the figure. As a result, the slide cam 34 engaged with the cam surface moves in the direction of arrow 36 according to the urging force of the spring 35. By the movement of the slide cam 34 in the direction of the arrow 36, the inclined cores 29 which are engaged with each other on the slide cam 34 on the cam surfaces are moved to the spring 31.
It moves in the direction of arrow 32 according to the urging force of. Therefore,
The die portion provided at one end of the inclined core 29 is die-cut from the undercut portion 28 a of the molded product 28. That is, at the same time when the mold is opened, the undercut portion 28a is also removed.

On the other hand, the mold closing operation is the reverse of the mold opening operation. When the mold is closed as shown in FIG. 4, the other end of the inclined core 29 contacts the slide cam 34,
The slide cam 34 contacts the slide cam 33, and the slide cam 33 is firmly fixed by the mold closing force.
It does not return even if it receives a force in the direction.

[0035]

As described above, according to the present invention, two parting surfaces are provided or two slide cams are provided. As a result, the structure of the tilt slide mechanism is greatly simplified and the number of parts is reduced. Therefore, it is possible to reduce the manufacturing cost of the molding die including the tilt slide mechanism.

Further, it has become possible to prevent the dimensional variation of the molded product and the fatigue failure of the inclined slide mechanism parts due to the conventional molding pressure.

[Brief description of drawings]

FIG. 1 is a view showing a tilt slide mechanism of a molding die of a first embodiment, showing a mold closed state.

FIG. 2 is a view showing a tilt slide mechanism of the molding die of the first embodiment, showing a die open state.

FIG. 3 is a diagram showing a molding process.

FIG. 4 is a view showing a tilt slide mechanism of a molding die of a second embodiment, showing a mold closed state.

FIG. 5 is a view showing a tilt slide mechanism of a molding die of a second embodiment, showing a mold open state.

FIG. 6 is a cross-sectional view showing a schematic structure of a conventional molding die.

FIG. 7 is an enlarged view of a tilt slide mechanism portion.

FIG. 8 is a diagram showing bending and concentrated stress generated in a slide cam.

[Explanation of reference numerals] 1 fixed side attachment plate (first mold part) 2 cavity support plate (first mold part) 3 core support plate (second mold part) 4 receiving plate (third mold part) 5 Spacer block (3rd mold part) 6 Cavity block (1st mold part) 7 Core block (2nd mold part) 8 Molded product 8a Undercut part 9 Inclined core 10 Inclined core holding plate (3rd mold part) ) 11 spring (biasing means) 13 link pin (approach separating means) 14 spring (approach separating means) PL1 parting surface PL2 parting surface

Claims (4)

[Claims] 1. A molding die for producing a molded product (8) having an undercut portion (8a) standing obliquely with respect to the mold opening / closing direction, the first mold being located on one side of the molded product (8). Mold part (1,2,6) and a second mold located on the other side of the molded product (8) for joining and separating from each other with respect to the first mold part (1,2,6). Part (3, 7) and third mold part (4,5, 10) movable in the mold opening / closing direction
And the first mold part (1, 2, 6) and the second mold part (3, 3
7) and the third mold part (4, 5, 5)
An approach separating means (13, 14) for separating and approaching the second mold part (3, 7) from the second mold part (3, 7); and an undercut part (8) of the molded product (8) at one end.
a) which is engaged with the second mold part (3, 7) and is movably supported by the second mold part (3) and has the other end of the third mold part (1).
0) and the inclined core (9) arranged at a position where it abuts against the undercut portion (8a) of the molded product (8), and the third mold portion (10) is separated.
And a biasing means (11) for constantly biasing in a direction of abutting against the mold. 2. When the mold is closed, the tilt core (9) has a mold part provided at one end of the tilt core (9) at a predetermined position of an undercut part (8a) of the molded product (8). The mold die according to claim 1, wherein the other end of the mold die is in contact with the third die part (10). 3. The approaching and separating means (14) comprises the third
Is provided between the mold part (4) and the second mold part (3), and is always attached in a direction separating the third mold part (4) and the second mold part (3). The molding die according to claim 1, comprising a biasing spring. 4. A mold die for producing a molded product (28) having an undercut portion (28a) standing diagonally with respect to the mold opening and closing direction, which is located on one side of the molded product (28), First mold part (21, 22, 26, 33) with one cam surface
And located on the other side of the molded product (28),
Second mold parts (23, 24, 27) for joining and separating the mold parts (21, 22, 26, 33) from each other, and to the second mold part (23) in a direction perpendicular to the mold opening / closing direction. Is movably supported by the first mold part (33) at one end thereof.
Slide cam means (34) having a second cam surface for engaging with the cam surface of the molded product (28) and having a third cam surface at the other end.
8a), which is a mold that is movably supported by the second mold part (27) and whose other end engages with the third cam surface of the slide cam means (34). (29)
And the slide cam means (34) and the second mold part (2
3) provided between the slide cam means (34)
A first biasing means (35) for biasing the first mold part (33) in the direction of abutting the first cam surface of the first mold part (33), the inclined core (29) and the second mold part (27). ), And second biasing means (31) for biasing the inclined core (29) in the direction of always contacting the third cam surface of the slide cam means (34). A mold die characterized in that.