JPH03138062A - Apparatus and method for pressurized casting - Google Patents

Abstract

PURPOSE:To miniaturize the whole casting apparatus including a casting die by penetrating secondary pressurizing hole arranged in a fixed die in the die to a fixed die plate besides the above fixed die and setting secondary pressurizing cylinder to outside of the fixed die plate. CONSTITUTION:In the fixed die 3 side, the secondary pressurizing hole 12 assembling the secondary pressurizing plunger 8 besides an injection sleeve 18 is arranged and the hole 12 is penetrated to the fixed die 3 and the fixed die plate 1 fitting the fixed die. Then, the end part thereof are opened to cavity C and the other end part thereof to outside of the fixed die plate 1 and the secondary pressurizing cylinder 10 for driving the secondary pressurizing plunger 8 is set as fixing at the outside of this fixed die plate. Therefore, space for stroke movement of the secondary pressurizing plunger 8 is extended and secured to the outside of fixed die plate 1, and further, as the secondary pressurizing cylinder 10 is set to the outside of fixed die plate 1, too, space between the fixed die and the movable die can be reduced, and the whole casting apparatus can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pressure casting apparatus and method suitable for die casting, low pressure casting, plastic casting, etc.

[Conventional technology]

BACKGROUND ART Conventionally, in the field of casting technology, a technique of injecting a molten material (hereinafter referred to as molten metal) into a cavity of a mold using an injection plunger is well known.

In such a casting process, the generation of shrinkage cavities during solidification of the molten metal and the entrainment of air, gas, etc. during casting are factors that cause quality deterioration, so various countermeasures have been conventionally taken.

For example, as a countermeasure against sinkholes,
As disclosed in Japanese Unexamined Patent Publication No. 64-53750, in addition to filling the mold cavity with pressure using an injection plunger, a plunger for secondary pressurization is used to fill the molten metal into the mold cavity. A method of secondary pressure casting of molten metal has been proposed.

In addition, as a countermeasure against air and gas entrainment, JP-A-60
As disclosed in Japanese Patent No. 210347, etc., there is one provided with a gas exhaust hole that communicates the cavity with the atmosphere, and a gas vent valve that opens and closes this gas exhaust hole at an appropriate timing.

Furthermore, as a method that takes both of the above measures, as disclosed in Japanese Patent Application Laid-Open No. 61-38770, a partial pressure piston sliding hole (secondary pressure hole) is provided in a movable type or a fixed type.
In addition to providing a gas vent hole and communicating with this sliding hole,
Secondary pressurizing piston (plunger) that also serves as a gas vent valve
There are some that incorporate.

[Problem to be solved by the invention]

By the way, in the conventional secondary pressure casting method, in order to incorporate the secondary pressurized parts inside the movable mold of the mold,
A device for secondary pressurization was required for each mold (eg, casting mold). Further, since the space required for the stroke operation of the secondary pressurizing plunger and the cylinder that is the source of the movement are installed inside the movable mold, it has been difficult to downsize the casting mold due to the installation space.

Furthermore, when the cavity is filled with molten metal and the casting is taken out after solidification is completed, a movable mold (for example, a movable mold) is created from a fixed mold (for example, a fixed mold), but in this case,
In order to achieve mass production, when the movable mold is removed from the fixed mold, the cast product follows the movable mold, and then an extrusion bottle installed in the movable mold is used to take out the cast product that has arrived at the movable mold.

In this case, the mold release force that separates the casting from the fixed mold is the force of the casting to the movable mold when the movable mold is separated from the fixed mold, and
The injection plunger installed in the fixed mold was the only force that pushed out the cast product. Therefore, if the force of the cast product against the fixed mold is large, the movable mold cannot pull out the cast product from the fixed mold.
Since the extrusion force of the injection plunger alone cannot extrude the cast product in a well-balanced manner, there have been cases where the cast product is divided and a portion remains in the fixed mold.

Furthermore, in the conventional degassing method, the rod for stroking the degassing valve and the parts that act as its drive source are provided in the movable mold, so a degassing device type is required for each mold, and the above-mentioned 2. Similar to the secondary pressurization method, there were cases in which it was not possible to properly separate the cast product from the fixed mold due to the spacing of the arrangement space.

Among the above-mentioned conventional techniques, the conventional technique disclosed in Japanese Patent Application Laid-Open No. 61-38770 suggests that the secondary pressurizing device may be provided as a fixed type instead of a movable type, but the installation space is limited. No concrete measures have been proposed as to how to improve this.

The present invention has been made in view of the above points, and its objectives are (a) to improve the installation space when installing a secondary pressurizing device and a degassing device, and to downsize the casting device; At the same time, we have improved the operating rate of secondary pressurization equipment, degassing equipment, etc., reducing the number of secondary pressurization and degassing equipment required, and further improving the mold releasability of cast products from fixed molds. and (b) to achieve effective degassing by rationally utilizing the operation of the plunger for secondary pressurization in a casting device using a secondary pressurization device. It's about satisfying.

[Means to solve the problem]

The present invention proposes the following problem-solving means to achieve the above object (a).

That is, the first problem-solving means includes a fixed mold and a movable mold that comes into contact with the fixed mold to form a cavity, and the fixed mold includes an injection sleeve that communicates with the cavity, and an injection mold that reciprocates within the injection sleeve. In the pressure casting apparatus provided with a plunger, the fixed mold side is provided with a hole for secondary pressurization incorporating a plunger for secondary pressurization in addition to the injection sleeve, and,
This secondary pressurizing hole is passed through the fixed mold and the fixed die plate to which the fixed mold is attached, and one end thereof is opened into the cavity and the other end is opened outside the fixed die plate,
A secondary pressurizing cylinder for driving the secondary pressurizing plunger is fixedly arranged outside the fixed die plate.

A second means for solving the problem is a pressurizing method which is provided with a fixed mold and a movable mold as described above, and the fixed mold is provided with an injection sleeve communicating with the cavity and an injection plunger that reciprocates within the injection sleeve. In the casting apparatus, in addition to the injection sleeve, a gas venting valve hole is provided on the fixed mold side through the fixed mold and a fixed die plate attached to the fixed mold, and one end of the hole is inserted into the cavity. The end is opened outside the fixed die plate, a rod with a gas vent valve is inserted into this valve hole, and a cylinder for driving the gas vent valve and the rod is fixedly arranged outside the fixed die plate. Become.

In addition, as a means to achieve the objective (b), we propose the following pressure casting method (this will be treated as the third means for solving the problem).

In other words, a cavity formed by combining a fixed mold and a movable mold is filled with molten material under pressure using an injection plunger that moves back and forth within the injection sleeve, and in this state, the molten material is solidified to form a cast product. In the pressure casting method.

A secondary pressurizing hole whose one end communicates with the cavity and a secondary pressurizing plunger that is driven by a cylinder and reciprocates in the secondary pressurizing hole are incorporated into either the fixed type or the movable type, and the injection In the step of pressurizing and filling the cavity with the molten material supplied from the sleeve by the forward movement of the injection plunger, before the cavity is filled with the molten material, the injection plunger is filled with the molten material at the same time as the forward movement of the injection plunger. The plunger for secondary pressurization is moved backward, and the air and gas in the cavity are moved to the side of the hole for secondary pressurization by the backward movement of the plunger for secondary pressurization, and then the cavity is filled with molten material. When the secondary pressurizing plunger is about to be pressed, the secondary pressurizing plunger is advanced toward the cavity.

[Effect]

According to the first means for solving the problem, the secondary pressurizing device type is transferred from the movable mold to the fixed mold, and the secondary pressurizing hole is passed through the fixed die plate in addition to the fixed mold. Therefore, it becomes possible to arrange the secondary pressurizing cylinder outside the fixed die plate.

In this way, the space for the stroke movement of the secondary pressurizing plunger can be extended to the outside of the fixed die plate, and the secondary pressurizing cylinder can also be placed outside the fixed die plate. The space between the fixed mold and the movable mold can be significantly reduced compared to the conventional method, and the entire casting apparatus including the casting mold can be downsized.

The fixed die plate on which the secondary pressure cylinder is placed is
Since there is sufficient installation space, restrictions on the size of the secondary pressurizing device are relaxed.

■Since the secondary pressurizing device is placed in the fixed mold, one secondary pressurizing device can be used in common for many molds, improving the operating rate of the secondary pressurizing device, The number of machines required will be reduced.

■In the process of removing the cast product after the molten metal has solidified,
When the movable mold is separated from the fixed mold, the cavity surface on the fixed mold side can be pushed out by at least two locations, the injection plunger and the secondary pressurizing plunger, and the extrusion balance is improved. Therefore, the cast product can be easily removed from the fixed mold, and continuous casting work can be carried out smoothly.

In addition, the second problem solving means is the second problem solving means of the first problem solving means.
Although the degassing device is moved to the fixed mold side instead of the next pressurizing device, the same effect as described in ■■■■ can be expected in this case as well.

In this case, especially in regard to (1), the injection plunger and the gas vent valve apply an extrusion force to the cavity surface on the fixed mold side.

Next, according to the third problem-solving means, pressure casting is performed using an injection plunger and a secondary pressure plunger, and at this time, a shaft-like action is performed.

That is, according to the present pressure casting method, ffi! is supplied from the injection sleeve. In step 1, in the process of pressurizing and filling the material into the cavity by the forward movement of the injection plunger, before the molten material is filled into the cavity, the secondary pressurizing plunger moves backward in synchronization with the forward movement of the injection plunger. do. Therefore, due to the backward movement of the plunger for secondary pressurization, the suction force increases by 1, and the air and gas in the cavity increase by 2.
Next, move to the pressure hole side. Therefore, the amount of gas and air contained in the molten material within the cavity can be significantly reduced.

After that, the plunger for secondary pressurization moves forward to perform secondary pressurization. In this case, gas (including air) is added to the secondary pressurization hole.
Even if the gas remains (part of the gas escapes from the small gap between the secondary pressurization plunger and the secondary pressurization hole), the secondary pressurization plunger pressurizes the molten material via this gas retention layer. Therefore, two-stroke pressurization can be performed without any problem.

In addition, in the conventional secondary pressure casting method, when moving the injection plunger forward to fill the cavity with molten material,
Next, the pressurizing plunger was moved back. Therefore, since the cavity is filled with the molten material while the maximum amount of gas, etc. is contained in the cavity, there is a tendency that the rate of gas, etc. being dragged into the cavity during filling with the molten material is higher than in the present problem-solving means.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical cross-sectional view showing a casting apparatus according to a first embodiment of the present invention in a state immediately before starting casting, and FIG. 2 is a vertical cross-sectional view showing a mold release state after the molten metal has solidified.

The illustrated apparatus is a horizontal cold chamber type casting apparatus, in which 1 is a fixed die plate and 2 is a movable die plate.

A fixed die plate 1 is fixed to a base B, and a fixed die 3 is attached to this fixed die plate 1. On the other hand, the movable die plate 2 is disposed on the base B so as to be able to reciprocate in the lateral direction in FIG. 1 by a hydraulic mechanism (not shown).

The movable die plate 2 includes a mounting plate 5a and a connecting member 5b.
The movable mold 4 is installed in a state facing the fixed mold 3 via the movable mold 4. Note that the fixed mold 3 and the movable mold 4 of this embodiment are made of metal molds.

A mold surface that becomes a mold manufacturing cavity C when the fixed mold 3 and the movable mold 4 are brought together is formed on each opposing surface. This cavity C includes a runner part 19, a product part 20,
Overflow 21. It is composed of a casting gate 22 that connects the runner section 19 and the product section 20, a gate 23 that connects the product section 20 and the overflow 21, and the like.

An injection sleeve 18 and a secondary pressurizing sleeve 12 are installed in parallel to the fixed die plate 1 and the fixed mold 3 so as to pass through them so as to communicate with the cavity C.

Among these, the injection sleeve 18 has one end facing the runner part 19 of the cavity C, and the other end protruding from the fixed die plate 1, and a molten metal inlet 18a is arranged in this protruding part. Also, inside the injection sleeve 18.

An injection plunger 14 is installed. Injection plunger 1
4 is driven by a hydraulic mechanism (not shown). 15,
16.17 is a limit switch, limit switch 1
5 detects the position where the injection plunger 14 advances the most (moves to the left in the figure), the limit switch 16 detects the displacement point for changing the moving speed of the plunger 14, and the limit switch 17 detects the position where the injection plunger 14 moves the most forward (leftward movement in the figure). Detects the position to retreat (move to the right in the figure).

The secondary pressurizing sleeve 12 is located above the injection sleeve 18, and has one end facing the overflow portion 21 and the other end opening to the outside of the fixed die plate 1, that is, the surface opposite to the fixed mold mounting surface. A secondary pressurizing plunger 8 is reciprocatably incorporated therein. A plunger 8 for secondary pressurization is connected to a cylinder 10 via a rod 8a and a coupling 9.
It is connected to the side rod 11. The cylinder 10 is attached to the end of a cylinder support 13 provided on the outer surface of the fixed die plate 1.

Moreover, since the rod 11 slides within the cylinder 10 by hydraulic pressure, this movement also causes the secondary pressurization plunger 8 to slide within the secondary pressurization sleeve 12.

Next, the extrusion pin mechanism mounted on the movable mold 4 side will be explained.

The push-out bottle mechanism includes a push-out plate 6 and pins 7a, 7b, and 7c.
It consists of These pins 7a, 7b, and 7c pass through the movable mold 4, and one end is fixed to the extrusion plate 6 outside the movable mold 4, and the other end of the pin 7a is attached to the runner part 19, and the other end of the pin 7a is fixed to the extrusion plate 6 on the outside of the movable mold 4. The other end faces the product section 20, and the other end of the pin 7c faces the overflow part 21. This extrusion bonding is
It is driven by a hydraulic cylinder (not shown).

24 is a timer.

Next, two operational examples of this embodiment will be explained.

(Operation example 1) First, before starting the casting process, move the movable die plate 2 and the movable mold 4 to the right using a hydraulic mechanism as shown in FIG. Close the mold by bringing them into contact. This forms a cavity C. At this time, the tips of the push-out pins 78 to 7c are at appropriate positions, for example, at positions that are substantially flush with the wall surfaces of the cavities of the runner section 19, the product section 2o, and the overflow section 21.

Further, the rod 11 for secondary pressurization is moved to the right as shown in FIG. 1, and the plunger 8 for secondary pressurization is retreated in advance, thereby maximizing the volume inside the cavity C.

Then, with the injection plunger 14 moved to the right, molten metal is injected from the molten metal injection port 18a, and the injection plunger 14 is advanced leftward in the figure at a low speed.

In this state, the injection sleeve 18 is filled with molten metal, and then, when the injection plunger 14 moves forward by a predetermined distance,
The limit switch 16 detects this, and based on this detection signal, the moving speed of the injection plunger 14 is switched from low speed to high speed, and the timer 24 is activated.

Then, after a certain period of time has elapsed, the gate 2 including the runner section 19fg
2. Product Department 20. Each cavity element of the overflow gate 23 and the overflow portion 21 is filled with molten metal. Also, at an appropriate time corresponding to that time, the cylinder 10 of the secondary pressurizing mechanism is operated to the left in the figure by the timer 24, the secondary pressurizing plunger 8 pressurizes the molten metal, and then the molten metal solidifies. Complete.

When the solidification of the molten metal is completed, as shown in FIG. 2, the movable die plate 2 and the movable die 4 are moved to the left in the figure to separate the movable die 4 from the fixed die 3.

At the same time, a force is applied to the injection plunger 14 and the secondary pressure plunger 8 in the left direction in the figure, and these elements 14 and 8 apply an extrusion force to the cavity surface of the cast product from the fixed mold 3 side, By this operation, the cast product is pushed out from the fixed mold 3 and follows the movable mold 4 side.

Next, the cast product is taken out from the movable mold 4 by pushing out the push-out pin 7 incorporated into the movable mold 4 in the right direction in the figure.

During mass production, casting is performed by repeating one or more operations in sequence.

In this embodiment, the molten metal is subjected to secondary pressure at the overflow portion 21, but the molten metal in the product section 20 may be directly subjected to secondary pressure.

(Operation Example-2) Next, another operation example will be explained. This operation example embodies claim 6 and will be explained with reference to the drawings in FIGS. 3 to 8.

When casting, first, as shown in FIG. 3, the movable mold 4 is brought into contact with the fixed mold 3 and the molds are clamped. Further, the secondary pressurizing plunger 8 is preliminarily moved toward the left (advanced) in the drawing, and the injection plunger 14 is moved toward the right (retracted) in the drawing.

In this state, the molten metal P is injected from the molten metal inlet 18a of the injection sleeve 18, and the injection plunger 14 is advanced at a low speed. As a result, the injection sleeve 1 as shown in FIG.
8 is filled with molten metal P.

Furthermore, the injection plunger 14 moves forward, but the secondary pressurizing plunger is moved back at the same time as this forward movement (
(shown in Figure 5). At this time, the volumetric flow rate at which the injection plunger 14 pushes the molten material into the cavity C (the displacement volume per unit time due to plunger movement) is always larger than the volumetric flow rate drawn by the secondary pressurizing plunger 8.
This is preferable in order to maintain the primary pressurization. Then, due to the retraction force caused by the backward movement of the plunger 8 for secondary pressurization, the gas, etc. in the cavity C moves toward the sleeve 12 for secondary pressurization.

Further, when the injection plunger 14 moves forward by a predetermined amount after the injection sleeve 18 is filled with molten metal, the limit switch 16 detects this and switches the moving speed of the injection plunger 14 from low speed to high speed. is activated.

In the step in which the secondary pressurizing plunger 8 moves backward, the runner section 19 of the cavity C is moved as shown in FIGS. 5 to 7. Cast gate 22. #20. Overflow gate 23. A portion of the secondary pressurizing sleeve 12 is sequentially filled with molten material from the overflow portion 21 . Then, looking at the timing for this filling, as shown in Figure 8,
The cylinder 10 is driven by the timer 24, the 8 plungers for secondary pressurization shift to Σ forward movement, and the secondary pressurization is executed.
In this state, solidification of the molten metal is completed.

The process of taking out the cast product after solidification is performed in the same manner as in Operation Example 1, so the explanation will be omitted.

Note that the retreating operation of the secondary pressurizing plunger 8 in this embodiment may be performed using the injection pressure from the injection plunger 14, in addition to being performed by the active operation of the cylinder 10.

According to the above embodiment, the following effects can be achieved.

(1) Since the secondary pressurizing device type was moved to the fixed die 3 side and its cylinder was placed outside the fixed die plate 1, the fixed die 3. It is possible to reduce the space between the movable molds 4 and thereby downsize the device.

(2) One secondary pressurizing device can be used in common for a large number of casting molds, the movability of the secondary pressurizing device is improved, and the number of required devices can be reduced.

(3) Also, the outer surface of the fixed die plate 1 (
Since there is sufficient space on the surface opposite to the casting mold installation surface, restrictions on the size of the secondary pressurizing device are relaxed.

(4) Furthermore, when the movable mold 4 is separated from the fixed mold 3 after the molten metal has solidified, the casting product is injected into the injection plunger 1 from the fixed mold 3 side.
4 and the secondary pressurizing plunger 8, the extrusion balance is improved and the releasability of the cast product from the fixed mold is improved.

(5) Furthermore, when the casting method of operation example 2 above is adopted, the gas contained in the molten material of the product part (
By reducing the amount (including air) and using secondary pressurization, it is possible to obtain high-quality cast products with fewer defects.

Next, another embodiment of the present invention will be described.

Figures 9 and 10 show an example in which the present invention is applied to a casting equipment equipped with a degassing device, of which Figure 9 shows the process before filling the cavity with molten metal, and Figure 10 shows the process after filling and solidification. It is a figure which shows the mold release state.

In the drawings, the same reference numerals as in other embodiments indicate the same or common elements.

This embodiment differs from the first embodiment in the following points. That is,
A valve hole 31 is inserted through the fixed mold 3 and the fixed die plate 1.
, and the gas vent valve 3Q and its rod 30a are passed through the valve hole 31.

One end of the valve hole 31 faces the overflow portion 21 of the cavity C, and the other end faces the outside of the fixed die plate 1. A cylinder 10 is arranged on the outside of the fixed die plate 1 via a support stand 13 in the same arrangement structure as in the first embodiment. Then, the rod 30a is the rod 1 on the cylinder 10 side.
1.

In this embodiment, the valve head of the gas vent valve 30 is located in the overflow part 21 to open and close one end opening (cavity side opening) of the valve hole 31.

Further, a portion 31a of the valve hole 31 from the cavity also serves as an exhaust passage. Reference numeral 32 denotes an exhaust passage formed in the fixed mold 3, one end of which branches off from the exhaust passage 31a, and the other end facing the atmosphere.

Next, the operation of this embodiment will be explained.

The clamping of the movable mold 4 with respect to the fixed mold 3 during casting and the initial setting of the extrusion pins 78 to 7c are the same as in the other embodiments described above.

After that, the gas vent valve 30 is connected to the rod 11 and the rod 30.
By advancing a in advance using the cylinder 10, it advances into the cavity C and opens the valve as shown in FIG.

In this state, the injection plunger 14 is moved backward as shown in FIG. 9, molten metal is injected from the molten metal inlet 18a of the injection sleeve 18, and the injection plunger 14 is advanced at a low speed.

In this state, the injection sleeve 18 is filled with molten metal.

Thereafter, when the injection plunger 14 moves forward by a predetermined amount.

The limit switch 16 detects this and switches the moving speed of the injection plunger 14 from low speed to high speed, and at this time, the timer 24 is activated.

Then, the molten metal flows into the runner section 19. Casting gate 22゜'A
part 20, overflow gate 23, and overflow part 21, the timer 24 controls the cylinder 10 at an appropriate timing during the flow of the molten metal.
operates in the right direction in the figure, and the gas vent valve 30 closes the valve hole 31. Here, the appropriate timing means that the molten metal reaches the valve hole 31.
This is the time when as much gas as possible can be discharged from the cavity C without ejecting to the side. Most of this gas is exhausted to the atmosphere through the valve hole 31 and the exhaust passage 32 before the gas vent valve 30 closes.

After the gas vent valve 31 is closed, filling of the cavity C with the molten metal is completed, and the molten metal solidifies under pressure.

Thereafter, the movable mold 4 is released from the fixed mold 3, but at that time, a force is applied to not only the injection plunger 14 but also the gas vent valve 31 in the left direction in the figure, so that these elements are released from the cast product. Provides extrusion force. As a result, as shown in FIG. 10, the cast product follows the movable mold 4 and leaves the fixed mold 3. Next, the cast product is separated from the movable mold 4 by pushing out the push-out pins 78 to 7C on the movable mold 4 side to the right in the figure.

During mass production, the above operations are repeated to perform casting.

According to this embodiment, in addition to producing the same effects as the first embodiment, there is an advantage that degassing can be performed effectively.

Next, a third embodiment of the present invention will be described based on FIGS. 11 to 15.

This embodiment shows an example of a casting apparatus having a secondary pressurizing function in addition to a gas venting valve function.

That is, in this embodiment, the valve hole 31A is penetrated through the fixed mold 3 and the fixed plate 1 as in the second embodiment, but this valve hole 31A is similar to the secondary pressure sleeve shown in the first embodiment. A gas vent valve 40 which also serves as a plunger for secondary pressurization is provided inside the cylinder. This valve 40 is connected via a rod 40a and a rod 11 to a rod 11 on the cylinder 10 side, which is disposed outside the fixed plate 1.

A second exhaust passage 32A communicating with the atmosphere is branched and connected to the valve hole 31A.

Next, the operation of this embodiment will be explained.

In this embodiment as well, first, the movable mold 4 is clamped to the fixed mold 3, and the push-out pins 78 to 7c are set at initial positions.

Next, the gas vent valve (
The plunger) 40 is moved back to open the exhaust passage 32A.

Thereafter, as in the previous example, the injection plunger 14 is retreated, molten metal is injected from the molten metal inlet 18a of the injection sleeve 18, and the injection plunger 14 is advanced at a low speed. In this state, the injection sleeve 12 is filled with molten metal, and then the injection plunger 14 is switched to a high-speed forward movement in response to a detection signal from the limit switch 16. At this time, timers 24 and 25 operate.

Then, the molten metal flows through the runner section 19. Casting gate 22° Product section 20. It passes through the overflow gate 23 and reaches the overflow part 21, but on the way, the limit switch 26 is activated at an appropriate timing by the timer 24 so that the cylinder 10
to the left by an appropriate distance. As a result, the gas vent valve 4o moves to point a as shown in FIG.
The gas exhaust passage 32A is closed. In this state, cavity C
is filled with molten metal. Note that in a process before the valve 40 closes, the gas in the cavity is exhausted to the atmosphere via the exhaust passage 32A.

Immediately after the cavity C is filled with molten metal, the timer 25
As a result, the cylinder 10 operates to the left in the figure, the valve 40 performs a forward movement, a secondary pressurizing operation is performed, and the solidification of the molten metal in the cavity is completed (FIGS. 13 and 14). Thereafter, in the mold release process, as shown in FIG. 15, the cast product is separated from the fixed mold 4 by the extrusion force of the valve 40 and injection plunger 14.
After that.

The cast product is removed in the same manner as in the other embodiments described above.

In addition, the second. In the third embodiment, the exhaust passages 32A are connected to the atmosphere, but it is also possible to connect these exhaust passages with a vacuum pump and apply it to vacuum die casting.

Therefore, this embodiment also has the same effects as the other embodiments.

In addition, although the above embodiment illustrated a horizontal casting apparatus, it is also applicable to a vertical casting apparatus.

〔Effect of the invention〕

As described above, according to the first problem-solving means and the second problem-solving means of the present invention, the size of the casting device can be reduced by improving the arrangement of the secondary pressure casting device or the degassing device. This makes it possible to improve the operating rate of the secondary pressurizing device, degassing device, etc., reduce the number of these devices required, and further improve the releasability of the cast product from the fixed mold.

Furthermore, according to the third means for solving the problem, by utilizing the retraction force caused by the backward movement of the plunger for secondary pressurization, effective degassing can be performed at the same time as the secondary pressurization, thereby improving the quality of the cast product.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the state of the casting apparatus according to the first embodiment of the present invention immediately before starting casting, FIG. 2 is a longitudinal cross-sectional view showing the mold release state after the molten metal has solidified, and FIG. From Figure 8,
An explanatory diagram showing an example of operation using the above-mentioned casting apparatus, FIG. 9 is a vertical cross-sectional view showing the state of the casting apparatus according to the second embodiment of the present invention immediately before starting casting, and FIG. 10 is a diagram showing the completion of solidification of the molten metal. 11 to 15, which are longitudinal sectional views showing the subsequent mold release state, are explanatory diagrams showing an example of the operation of the casting apparatus according to the third embodiment of the present invention. . 1... Fixed die plate, 2... Movable die plate, 8a... Rod, 10... Secondary pressure cylinder,
12... Secondary pressurizing hole, 14... Injection plunger,
18... Injection sleeve, 30... Gas vent valve, 30
a...Rod, 31...Valve hole, 32...Exhaust passage, 4o...Gas vent valve that also serves as secondary pressurizing plunger, 40
a...Rod. Figure 4 Figure 8 Figure 12 Figure 13

Claims (1)

[Claims] 1. A fixed mold and a movable mold that abuts against the movable mold to form a cavity, and the fixed mold includes an injection sleeve that communicates with the cavity, and an injection plunger that reciprocates within the injection sleeve. In the pressure casting apparatus, the fixed mold side is provided with a secondary pressurizing hole incorporating a secondary pressurizing plunger in addition to the injection sleeve, and
This secondary pressurizing hole is passed through the fixed mold and the fixed die plate to which the fixed mold is attached, and one end thereof is opened into the cavity and the other end is opened outside the fixed die plate,
A pressure casting apparatus characterized in that a secondary pressurizing cylinder for driving the secondary pressurizing plunger is fixedly disposed outside the fixed die plate. 2. In the first aspect, the secondary pressurizing plunger temporarily expands the volume inside the cavity by retreating before or when the injection plunger pressure-fills the molten material into the cavity, When the molten material is almost completely filled into the cavity, the secondary pressurizing plunger moves forward to apply a secondary pressure to the molten material, and when the mold is opened after the molten material solidifies, the secondary pressurizing plunger A pressure casting apparatus, wherein the operation mode is set so that a plunger and the injection plunger apply an extrusion force from the fixed mold side. 3. A pressurizing device comprising a fixed mold and a movable mold that comes into contact with the fixed mold to form a cavity, and the fixed mold is provided with an injection sleeve that communicates with the cavity and an injection plunger that reciprocates within the injection sleeve. In the casting apparatus, in addition to the injection sleeve, a gas venting valve hole is provided on the fixed mold side through the fixed mold and the fixed die plate to which the fixed mold is attached, and one end of the hole is inserted into the cavity. The end is opened outside the fixed die plate, a rod with a gas vent valve is inserted into this valve hole, and a cylinder for driving the gas vent valve and the rod is fixedly arranged outside the fixed die plate. Pressure casting equipment characterized by: 4. In the third aspect of the present invention, the pressure casting is configured such that a gas exhaust passage is branched and connected in the middle of the valve hole disposed in the fixed mold, one end of which connects to the valve hole and the other end of which connects to the atmosphere. Device. 5. The pressure casting apparatus according to claim 3 or 4, wherein the gas vent valve has a plunger shape and is set to also serve as a plunger for secondary pressurization. 6. The cavity formed by combining the fixed mold and the movable mold is filled with molten material under pressure using an injection plunger that moves back and forth within the injection sleeve, and in this state the molten material is solidified to form a cast product. In the pressure casting method, either the fixed mold or the movable mold has a secondary pressurizing hole whose one end communicates with the cavity, and a secondary pressurizing hole that is driven by a cylinder and reciprocates in the secondary pressurizing hole. In the step of incorporating a pressure plunger and pressurizing and filling the cavity with the molten material supplied from the injection sleeve by the forward movement of the injection plunger, the forward movement of the injection plunger is performed before the molten material is filled into the cavity. The plunger for secondary pressurization is moved backward at the same time as the plunger for secondary pressurization, and the air and gas in the cavity are moved to the hole side for secondary pressurization by the backward movement of the plunger for secondary pressurization. A pressure casting method characterized in that the secondary pressure plunger is advanced toward the cavity side when the molten material is about to be filled. 7. In claim 6, when the forward motion of the injection plunger and the backward motion of the secondary pressurizing plunger are performed at the same time, the displacement per unit time due to the advance of the injection plunger is A pressure casting method in which the displacement is set to be larger than the displacement per unit time due to retraction of the plunger for subsequent pressurization.