JPH09206909A - Die for forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a formed product having large undercut shape in a simple and compact mold structure by shaking core so as to separate from the undercut shape in the formed product. SOLUTION: At the time of completing cooling, an upper die 1 is relatively shifted upward to a lower die 16 to start the die opening. Since the shaking core is freely shakably fixed to a first supporting pin 12 in a through-hole 11 for the core arranged in the upper die 1, a force for shifting upward is applied to the shaking core 13 the same time of starting the rising of the upper die 1. This force is transmitted to the end part 13c of the shaking core 13, but a slide core 15 is not linked with the upper die 1 at the initial stage of the die opening and the slide core 15 is not shifted. Therefore, the end part 13c of the shaking core 13 is shifted along the inclining surface 15c of the slide core 15 (Fig. 3(b)). At the time of further advancing the rising of the upper die 1, a second supporting pin 14 is abutted on the upper end of a slotted hole arranged in the slide core 15, and the slide core 15 is risen by linking with the rising of the upper die 1 (Fig. 3(c)).

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 molding a molded product having an undercut portion.

[0002]

2. Description of the Related Art When a product molded by a die has an undercut portion, it is necessary to open the die so as not to interfere with the undercut portion.
No. 169225, a slide core is provided in an undercut portion in a mold to form a molded product, and the slide core is slid by an inclined pin or hydraulic drive after molding to form an undercut portion. It is common to mold from the mold. This will be described with reference to FIGS.

The die forming apparatus shown in the figure is for casting a product W having an undercut portion A. In the figure, 101 is a fixed die, 102 is a movable die, and 103 is an undercut molding core. Is. The cavity 104 is formed by the fixed die 101, the movable die 102, and the core 103. The fixed die 101 is provided with a guide pin 105 that is inclined downward at a predetermined angle in the drawing. Movable type 10
2 is formed with a pin escape hole 106. The pin escape hole 106 is formed by the guide pin 1 in the mold clamping state.
05 is loosely inserted. The core 103 has a protrusion 108, which is an undercut forming portion, formed on the tip end side, and an inclined hole 109 formed on the base end side so as to have the same inclination as the guide pin 105. When is moved, the guide pin 105 is slidably fitted into the inclined hole 109.

In the mold forming apparatus having the above structure, the molten metal is supplied to the cavity 104 in the mold clamping state shown in FIG. 4 and is cooled and solidified. Thereafter, the mold opening is started as shown in FIG.
It moves downward in the figure along the inclination of 5. In this way, the core 103 and the product formed in the cavity 104 are released from the mold, and the product can be taken out.

[0005]

In the above prior art,
Since the core is driven by the tilted guide pin provided in the movable die, when molding a product with a large undercut, a large sliding stroke by the guide pin must be taken. The length of the apparatus itself becomes large, the apparatus becomes large in size, the mold structure becomes complicated, and the operation becomes unstable due to prying or the like. The degree of instability becomes more remarkable when the mold is heated and expansion strain occurs.

The present invention has been made in view of the above circumstances, and a technique for forming a molding product having an undercut portion has a simple structure, is compact, and stabilizes the operation. It is a specific subject.

[0007]

In order to solve the above technical problems, the technical means taken in claim 1 of the present invention comprises a fixed mold and a movable mold which can be opened and closed with respect to the fixed mold. A molding die for molding a molded product having an undercut portion in the opening / closing direction of the movable die, wherein the molding die is in a through hole provided in the fixed die or the movable die. A first support member arranged and a swing core supported by the first support member and swingable about the first support member, and the swing core has the undercut portion in a mold clamping state. An undercut abutting portion that abuts against the undercut abutting portion, and the swing core moves in the die opening direction as the die is opened, and swings around the support member in a direction of releasing from the undercut portion. Is characterized by It is that you have a mold.

According to the above technical means, in the mold opening step, the rocking core moves in the mold opening direction and rocks around the supporting member, and this rocking movement causes the mold to be released from the undercut portion of the molded product. To be done. In the case of using a conventional tilt pin, when molding a molded product having a large undercut shape, a large sliding stroke of the tilt pin had to be taken, which necessitated a large-scale and complicated equipment. By releasing from the undercut portion of the molded product by the swinging motion as in the present invention, a molded product having a large undercut portion can be molded with a simple and compact equipment configuration.

In order to solve the above technical problems, the technical means taken in claim 2 of the present invention is that the molding die is inside the through hole provided in the fixed die or the movable die. A second support member arranged and a slide core movable along the mold opening / closing direction and having a slot formed in the mold opening / closing direction to loosely fit the second supporting member, wherein the slide core is in the mold opening / closing direction. With an inclined surface inclined with respect to
The swing core has an end portion at an end opposite to the undercut portion with respect to the first support member, and the end portion of the swing core and the inclined surface of the slide core are engaged with each other. Wherein the end portion swings along the inclined surface as the mold is opened, and the undercut contact portion swings in a direction of releasing from the undercut portion. 1 is the molding die described in 1.

According to the above technical means, when the mold opening is started, a force for moving in the mold opening direction is generated in the oscillating core supported by the first supporting member, and this force is applied at the end portion thereof. It is transmitted to the inclined surface of the mating slide core. Therefore, the end portion of the oscillating core also generates a force to rotate along the inclined surface. This force acts as a driving force for the rocking to start the rocking of the rocking core, and the undercut contact portion of the rocking core also rocks to be released from the undercut portion of the product. In this way, the molded product and the oscillating core are released from the mold.

In order to solve the above-mentioned technical problem, the technical means taken in claim 3 of the present invention is the swing when the undercut contact portion of the swing core is released from the undercut portion. The dynamic speed is higher than the mold opening speed in the mold opening, which is the molding die according to claim 1 or 2.

In the present invention, when the oscillating core is opened, the oscillating core moves in the dies opening direction and oscillates about the first supporting member. Therefore, when the moving speed in the mold opening direction exceeds the swinging speed, the swinging core may be galled at the contact point between the swinging core and the product. According to the above technical means, the rocking speed of the rocking core is set to be higher than the mold opening speed in order to prevent galling on the product.

In order to solve the above technical problems, the technical means taken in claim 4 of the present invention is characterized in that the slide core is biased in a mold clamping direction by a biasing member. The molding die according to claim 2 or 3.

According to the above technical means, the slide core is biased in the mold clamping direction by the biasing member. This prevents the slide core from moving in the mold opening direction due to the force transmitted from the swing core when the movable die is raised.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As an example, a casting mold for casting an intake manifold will be described.

FIG. 1 is a diagram showing an entire mold in an embodiment of the present invention.

In the figure, a movable upper die 1 is connected to an upper die base 2, and a fixed lower die 16 is connected.
Is connected to the lower die base 17. In the upper mold 1,
Extrusion through-holes 3a and 3b are formed from the upper surface of the upper die 1 to the cavity space 21, and the upper die-extruding pins 5a and 5b fixed to the upper die-extruding plate 4 are formed in the extrusion through-holes 3a and 3b. Has been inserted. Further, the lower die 16 is formed with through holes 6a, 6b, 6c from the lower surface of the lower die 16 to the cavity space 21, and is fixed to the lower die pushing plate 7 in the through holes 6a, 6b, 6c. The lower die extruding pins 8a, 8b, 8c are inserted. The sprue flock 9 is disposed on the left side of the drawing at the boundary between the upper mold 1 and the lower mold 16, and the hot water supplied from the sprue flock 9 passes through the runner 10 and the cavity space 21.
Communicate with Further, the upper die 1 is provided with a core through hole 11 extending from the upper surface of the upper die 1 in the drawing to the cavity space 21. A first support pin 12 is attached in the middle of the core through hole 11, and the first support pin 1
An oscillating core 13 is swingably supported by 2. Further, a second support pin 14 is further attached in the middle of the core through hole 11, and a slide core 15 is slidably fitted in the second support pin 14 through a long hole 18 so as to be slidable. The cavity space 21 includes an upper die 1, a lower die 16,
Although it is formed in a space surrounded by the swing core 13 and the slide core 15, an undercut portion in the mold opening / closing direction is formed by an undercut contact portion 13a of the swing core. On the other hand, the cavity contact portion 15 a of the slide core 15 contacts the non-undercut portion of the cavity space 21.

A slide core push-out pin 19 is arranged above the slide core 15 in the figure. A stopper 20 is fixedly arranged on the upper surface of the fixing portion 21 provided on the upper die base 2 in the figure above the push pin 19 for the slide core in the figure. A flange portion 19a is formed in the circumferential direction in the middle of the slide core push-out pin 19, and a spring 22 is arranged between the flange portion 19a and the upper surface of the fixed portion 21. Therefore, push pin 1 for slide core
9 is always urged downward by a spring 22.

FIG. 2 shows the swing core 1 in the mold clamped state.
3 is an enlarged layout view of 3 and a slide core 15. FIG.

In FIG. 2, the oscillating core 13 has a tip portion 13
b, the tip portion 13b is in contact with a further tip portion of the tip surface 15b of the slide core 15. Further, the swing core 13 has a tip portion 13b centered on the first support pin 12.
It has an end portion 13c which is an end located on the side opposite to the end portion 13c, and the end portion 13c is in contact with the approximate center of the inclined surface 15c of the slide core 15. The inclined surface 15c is inclined by a predetermined angle θ with respect to the mold opening / closing direction (the vertical direction in the present embodiment). A central surface 15d is formed between the tip surface 15b of the slide core 15 and the inclined surface 15c.
Therefore, when the oscillating core 13 oscillates to the right in the figure with the first support pin 12 as the center, the facing surface 13d of the oscillating core 13 enters and faces the inclined surface 15c and the central surface 15d of the slide core. At this time, the maximum diameter of the swing core 13 and the slide core 15 in the horizontal cross section is smaller than the diameter of the through hole 11 provided in the upper die 1, so that the swing core 13 has a maximum diameter.
Also, the dimensions of the slide core 15 are determined. Further, in the mold clamped state, the second support pin 14 is
It abuts on the end (the lower end in the figure) of the mold clamping direction of the elongated hole 18 formed in the. Therefore, even if the movable mold starts to open,
At the initial stage, the second support pin 14 only moves in the elongated hole in the upward direction in the drawing, and the slide core 15 does not move in conjunction with the movable die. When the mold opening for the stroke of the elongated hole 18 is performed, the second support pin 14 comes into contact with the end (the upper end in the drawing) of the elongated hole 18 in the mold opening direction. Therefore, at this time, the slide core 15 moves in conjunction with the movable mold. To do.

The operation of the casting mold having the above structure will be described below.

Hot Water Supply / Cooling Process The molten metal is poured from the sprue block 9, and the molten metal is run 10
Hot water is supplied to the cavity space 21 through the. Cooling and holding for a certain period of time, the molten metal is solidified in the cavity to solidify the molten metal. The state at this time is the state shown in FIG.

Mold Opening Step Upon completion of cooling, as shown in FIG. 3 (b), the upper mold 1 moves relative to the lower mold 16 upward in the drawing, and the mold opening is started. At the same time when the mold opening is started, the upper mold extruding pins 3a and 3b are extruded through the upper mold extruding plate 4 by an extruding mechanism (not shown). Further, the slide core 15, which is urged downward in the drawing by the spring 22 via the push pin 19 for the slide core, is similarly pushed out. Here, the push-out pins 3a and 3b and the slide core 15 are pushed out in the direction of the lower die 16 when viewed from the upper die 1, and when seen from the lower die 16 or an operator who works externally, The pins 3a, 3b and the slide core 15 remain in that position, and only the upper mold 1 moves relatively upward. On the other hand, the swing core 13
Is swingably fixed to the first support pin 12 in the core through-hole 11 provided in the upper die 1, so that the upper die 1 starts to move up, and at the same time, moves to the swing core 13 upward. It takes force to do. At this time, as shown in FIG. 2, both ends of the swing core 13 are in contact with the tip surface 15b and the inclined surface 15c of the slide core 15. Therefore, when a force that moves upward is applied to the swing core 13, the force is transmitted to the end portion 13c of the swing core 13. However, as described above, the slide core 15 is not interlocked with the upper mold 1 in the initial stage of mold opening, and is biased in the mold clamping direction (downward direction in the drawing) by the spring 22. The core 15 does not move. Therefore, the end portion 13c of the swing core 13 moves along the inclined surface 15c of the slide core 15. This movement is seen from the first support pin 12.
This is an operation of swinging counterclockwise in the drawing. Therefore, the tip portion 13b of the swing core 13 and the undercut contact portion 13 are
a also swings counterclockwise. This swinging direction is a direction in which the undercut contact portion 13a is released from the product.
Then, the release of the product and the swing core 13 is started.
It should be noted that the above-described operation is performed at a speed higher than the ascending speed of the oscillating core 13, that is, the mold opening speed, than the undercut contact portion 13 of the oscillating core 13.
It is performed so that the rocking speed of a is faster. This is because the shapes of the swing core 13 and the slide core 15 are determined in the design drawings so that the swing stroke is larger than the lift stroke of the swing core 13. Fig. 6 shows the factors that affect the design
At the tilt angle θ of the slide core 15 and the swing core 13
Are the distance AB, the distance AC, the distance BC, and the inclination angle φ of the swing core 13 in the mold clamping state. Here, the point A in the swing core 13 is the swing center, the point B is the end portion 13c,
A point C is an intersection of a straight line connecting the points A and B and a horizontal line 1 (a straight line orthogonal to the mold opening direction) from the undercut contact portion 13a.

As shown in FIG. 3 (c), when the upper die 1 is further raised, the tip portion 13b of the swing core 13 swings further counterclockwise until the facing surface 13d of the swing core 13 slides. To be faced with.

When the upper mold 1 further rises, the second support pin 14 comes into contact with the upper end of the elongated hole 18 formed in the slide core 15 in the figure. In such a state, the slide core 15 rises in conjunction with the rise of the upper die 1. At this time, since the maximum diameter of the horizontal cross sections of the swing core 13 and the slide core 15 is designed to be smaller than the diameter of the core through hole 11, the swing core 13 and the slide core 15 have the maximum diameter of the core through hole 11. Rise without interfering with. In this way, the mold opening process is completed.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. The present invention relates to, in a molding die for molding a product having an undercut portion, the core contacting the undercut is rocked to release from the product, or the inclination angle and the mold opening direction provided in the mold. Is used to swing the core that abuts against the undercut to release the product, and the present invention can be applied within a range not departing from these points.

[0027]

The invention of claim 1 has the following effects.

Since the oscillating core oscillates so as to separate from the undercut shape of the molded product, it has a simple and compact mold structure and a large undercut as compared with those using a conventional inclined pin or the like. A molded product having a cut shape can be molded.

The invention of claim 2 has the following effects.

In addition to the oscillating core, a slide core is provided in the movable die, and the oscillating core is oscillated by utilizing the mold opening force and the inclined surface of the slide core. It is possible to form a molded product having a large undercut shape with a simple and compact mold structure that does not require a driving force such as hydraulic pressure.

The invention of claim 3 has the following effects.

Since the rocking speed when the rocking core rocks is set to be higher than the mold opening speed, the rocking core does not bite the product and the product and the core are smoothly separated. It is possible to mold and take out the product with stable operation.

The invention of claim 4 has the following effects.

By urging the slide core in the mold clamping direction by the urging member, the relative position of the oscillating core and the slide core at the time of mold opening is surely changed, and the oscillating core is surely oscillated. You can

[Brief description of drawings]

FIG. 1 is an overall view of a molding die according to an embodiment of the present invention.

FIG. 2 is a layout view of the swing core and the slide core during mold clamping according to the embodiment of the present invention.

3A and 3B are diagrams showing the operation of the molding die in the embodiment of the present invention, in which FIG. 3A is a mold clamping state, and FIG. 3B is a mold opening state and a swing core is swinging. (C) shows a state in which the swing of the swing core is completed during mold opening.

FIG. 4 is a diagram showing a mold clamping state of a mold according to a conventional technique.

FIG. 5 is a diagram showing a mold opening state of a mold according to a conventional technique.

FIG. 6 is a diagram illustrating a factor for designing the swing stroke to be larger than the stroke in the mold opening direction of the swing core in the embodiment of the present invention.

[Explanation of symbols]

 1 Upper Die (Movable) 2 Upper Die Base 11 Core Through Hole (Through Hole) 12 First Support Pin (First Support Member) 13 Swing Core 13a Undercut Abutment 13b Tip 13c End 13d Opposed Face 14 Second Support Pin (Second Support Member) 15 Slide Core 15a Cavity Abutting Part 15b Tip Surface 15c Inclined Surface 15d Center Surface 16 Lower Die (Fixed) 17 Lower Die Base 18 Long Hole 19 Slide Core Extrusion Pin ( Biasing member) 19a Collar part (biasing member) 20 Stopper 21 Fixed part (biasing member) 22 Spring (biasing member)

Claims (4)

[Claims] 1. A molding die for molding a molded article having a fixed die and a movable die that can be opened and closed with respect to the fixed die and having an undercut portion in the opening and closing direction of the movable die, The molding die includes a first support member arranged in a through hole provided in the fixed die or the movable die, and the first die.
A swing core supported by a support member and swingable about the first support member, and the swing core has an undercut contact portion that contacts the undercut portion in a mold clamping state, A mold for molding, wherein the swing core moves in a mold opening direction as the mold is opened, and swings in a direction of releasing from the undercut portion around the support member. 2. The molding die includes a second support member arranged in the through hole provided in the fixed die or the movable die, and the second support member formed along a die opening / closing direction. A slide core movable in the mold opening / closing direction having an elongated hole for loosely fitting the slide core, the slide core having an inclined surface inclined with respect to the mold opening / closing direction, and the rocking core with respect to the first support member. Has an end portion at the end opposite to the undercut portion, the end portion of the oscillating core and the inclined surface of the slide core are engaged with each other, and as the mold opening is performed, the end portion is The molding die according to claim 1, wherein the undercut contact portion swings along the inclined surface and swings in a direction of releasing from the undercut portion. 3. The swing speed when the undercut contact portion of the swing core is released from the undercut portion is faster than the mold opening speed in mold opening. Alternatively, the molding die according to 2. 4. The slide core is biased in a mold clamping direction by a biasing member.
Alternatively, the molding die according to item 3.