JPS6149764A - Method and device for forging molten metal - Google Patents

Abstract

PURPOSE:To obtain a casting having excellent mechanical properties by filling a molten metal into a die cavity and lowering a lower punch to increase the cavity volume then lowering an upper punch to pressurize the molten metal and escaping the excess molten metal to a prescribed space. CONSTITUTION:The molten metal is filled into the cavity 10 formed of a lower die 1, the lower punch 8 and a counter balance piston 9. The punch 8 is then lowered to increase the cavity volume and thereafter the corresponding punch 16 is pushed into the cavity 10 to pressurize the molten metal in the cavity 10. On the other hand, the excess molten metal is escaped into the space formed when the piston 10 is lowered. The lower die 1 is lowered to expose the solidified metal when the molten metal solidifies. The exposed forging product is thereafter taken out by the upper punch 16. The molten metal is supplied always at the specified rate into the cavity according to the above-mentioned method and therefore the molten metal is surely pressurized to the intended pressure, by which the generation of defects in the product is thoroughly effectively prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a molten metal forging method and method for solidifying a secondary casting with excellent mechanical properties by solidifying the molten metal in a mold cavity by reducing the pressure at the cutting edge. This is related to the device.

[Conventional technology]

As a conventional molten metal forging method of this type, for example, JP-A No. 56-186270 (Japanese Patent Application No. 138982-1982)
I have a friend who was disclosed in issue].

In this molten metal forging method, molten metal is supplied into a cavity formed by an upper mold and a lower mold by an injection cylinder provided in the lower mold, and then into the injection cylinder! In addition to pressuring the molten metal in the cavity, it is also installed in a part of the upper mold.
When supplying molten metal to the cavity, the movable part located in the retracted position is advanced, and the molten metal in the cavity is also pressurized by the movable part until it takes the shape of the product, and belongs to the so-called plunger pressure indirect pushing method. It is something.

[Problem that the invention seeks to solve]

However, in this conventional technology, since it is an indirect pushing method, when the movable part moves forward and presses the molten metal in the cavity, the chill solidified in the molten metal pool is destroyed and enters the cavity. .

There are nine problems that reduce the mechanical properties of the product: Local pressurization of the molten metal by the injection cylinder and moving parts makes it impossible to pressurize the entire molten metal at a sufficiently high pressure.
As a result, the problem often arises that cavities and other casting defects within the product cannot be adequately removed. Moreover, in this prior art, although a certain amount of molten metal is supplied into the cavity with the negative stroke of the injection cylinder, there is no means for quantifying the molten metal, so the amount of molten metal supplied into the cavity cannot be controlled. It is not possible to make the molten metal uniform at all times, and as a result, especially when the amount of hot water supplied is insufficient, the molten metal cannot be pressurized to the required pressure, which further promotes the occurrence of casting defects. Problems The present invention has been made by focusing on the problems of the prior art, and it is possible to effectively prevent chill from entering the cavity and to pressurize the molten metal in the cavity FE3 at a sufficiently high pressure. Yes, even more.

It is an object of the present invention to provide a molten metal forging method and an apparatus for implementing the same, which can always keep the amount of molten metal supplied into a cavity constant.

[Friendly means and effects for solving the problem] The molten metal forging method of the present invention supplies molten metal into the cavity formed by the lower mold, the lower punch, and the force-intervalance piston until the cavity is filled. a second step of lowering the lower punch to increase the cavity volume; and a second step of lowering the lower punch to increase the cavity volume. After the molten metal is solidified, the molten metal is pressurized at a predetermined pressure, the excess molten metal is released into the space formed by the descent of the counterbalance piston, and the molten metal is solidified.

This method combines the fourth step of lowering the lower mold to expose the product therefrom, and the fifth step of lifting the product using an upper punch.

In this molten metal forging method, in the first step, the molten metal is supplied until the cavity is completely filled to ensure a constant and uniform supply of molten metal. By increasing the volume of the cavity by the amount equivalent to the volume entering the cavity, spilling of the molten metal inside the cavity is prevented, and furthermore, by pushing the upper punch in the eighth step, the entire molten metal is uniformly distributed under a sufficiently large predetermined pressure. Pressure is applied to reliably prevent pressure generation from casting defects, and while ensuring that surplus molten metal escapes in the first and second processes and CCF product dimensions are always at specified values, in relation to the constant supply of molten metal in the first process. In this way, the amount of molten metal that escapes is sufficiently reduced to allow the post-processing of the product to be finished, and by lowering the lower die in the fourth step, less power is consumed.

Prepare for the intended removal of the product and then
In the process, the product is removed from the bottom/(inch) and counterbalance piston, which reduces the strength of the product without casting defects and significantly reduces the amount of machine labor required for the product. will be done.

The apparatus of the present invention used for carrying out the molten metal forging method for octopuses is provided with a lower mold having a through hole with a predetermined contour, and is also provided with means for lifting and lowering the cylinder for reciprocating the lower mold. In addition, a counterbalance piston that is normally positioned at the upper limit position and backed up by a predetermined force is placed in the upper mold and the lower mold, which is driven up and down within a certain range. It has a through hole and a corresponding contour.

・At the same time, the upper punch, which moves up and down with respect to the cavity formed by the lower mold, the lower bunch, and the counterbalance piston, is fixed, and a stopper is provided to specify the lowering position of the upper punch. According to the device:
The first to fifth steps described above are also simplified.

〔Example〕

The present invention will be explained below based on illustrated examples.

FIG. 1 is a cross-sectional view illustrating the device of the present invention. In the figure, 1 indicates a lower mold, 2 indicates nine through holes provided in the lower mold 1, and the through holes 2 in this example are connected to the piston of the engine. It has a contour that corresponds to the plane #l of the connecting rod that connects it to the crankshaft.

In the illustrated example, the lower end of the lower die 1 is fixed to the pace plate 8 and connected to a replica cylinder number, which is an example of an elevating drive means, thereby causing the lower die 1 to move up and down. Of course, this double-acting cylinder 4 can be a hydraulic or pneumatic cylinder, but here, in order to particularly increase the force in the downward direction of the lower mold l, the double-acting cylinder 4 has a rond side cylinder located at the upper part thereof. A liquid chamber 4a is used, and a cylinder side chamber is used as an air chamber 4b.

In this example, the lifting and lowering of the lower mold 1 based on the operation of the double-acting cylinder 4 is guided by the guide post 6 in which the pace plate 81C is installed, and its lowering limit position is determined.

This is also set in the pace plate 8 by the L7j lower limit stopper 6, and its upper limit position is set to 1. Each is specified by an upper limit stopper 7 which is screwed onto the lower limit stopper 6 and penetrates through the side end portion of the lower mold l. ,.

Here, a lower bunch 8 having a contour corresponding to the contour of the lower punch 8 is arranged in the through hole of the lower mold 1 so as to be movable up and down within a certain range, and a lower punch 80 is placed in the through hole of the lower die 1. arranging a counterbalance piston 9 that operates;
These lower mold 1, lower ζ punch 8, and counterbalance piston 9 form a required cavity IO. The vertical movement of the lower bunch 8 is also reduced by the relative displacement of the lower punch 8 with respect to the rod member 12 based on the supply and discharge of compressed air to the air chamber 11 provided therein, and its upper limit position is at the punch grade 1B. The setting is provided by the stopper pin 14, and the fc lower limit position is provided by the punch plate 18 itself which fixes the rod member 12 to the pace plate 8. Note that the downward movement of the lower punch 8 is
Of course, this can be brought about by modifying the exhaust air from the air chamber 11, but as will be described later, the upward force exerted by the air chamber pressure on the lower punch 8 can also cause a large downward force to be exerted on it. You can also do it. Further, the counterbalance piston 9 is normally positioned at its upper limit position backed up by a predetermined force such as hydraulic pressure, and the force acting on its top surface exceeds a predetermined value. It moves downward only when c.

- 10,000, an upper punch 16 having a contour corresponding to the through hole 2 of the lower mold 1 and moving back and forth into the cavity 10 is provided on the upper mold 15 which is moved up and down with respect to the F lower pump 1 by a reciprocating drive means (not shown). This makes it possible to directly pressurize the molten metal within the cavity. Also, here, the upper die 15 and the upper punch 16
An ejector turbine 17 is provided which extends through the punch and is capable of being ejected from the upper punch surface by means of a known ejector mechanism. In addition, upper bunch 16
Furthermore, the lower limit position of the upper die 15 is specified. In this example, the upper die 15 is provided with a spacer 18, and this spacer 18 is positioned so as to abut against the top surface of the guide post 5 which also acts as a stopper 19.

Furthermore, in the illustrated example, in order to lower the lower punch 8 against the pressure in the air chamber in conjunction with the lowering operation of the upper edge 16, the air chamber 11 in the upper die 15 is also an air chamber filled with high-pressure air. 20 is provided, and the lower end surface of the bushing rod z1, which is slidably housed in the air chamber zO, is
It is made to be able to come into contact with the upper end surface of a rod 2B that projects upward from the flange portion and passes through the lower mold 1.

Molten metal forging using the apparatus configured as described above is performed as follows.

First, as shown in FIG. 1, the upper and lower molds 15.1 are set to the open state, and the upper molds 1 and 5, the lower punch 8, the counter balance, and the spring piston 9 are set to their upper limit positions.
A cavity 10 with a required volume is formed by them.

Note that this cavity volume can be adjusted to v! by changing the position of the upper limit stopper 7 of the lower mold 1. Of course, you can do all four.

Here, the required volume of the cavity lO is generally set so that the molten metal supplied thereto is large enough to compensate for the solidification shrinkage and still make it sufficiently easy to rework the product. For example, the volume is selected so that it can accommodate a somewhat larger amount of molten metal than the required amount.

Next, a constant amount of molten metal is supplied into the cavity 10 until it is filled to the top, and then, when the upper mold 15 starts descending, the lower punch 8 is pressed into contact between the bushing rod 21 and the rod z2. For example, it is gradually lowered to its lower limit position against the internal pressure of the air chamber 11. Due to this,
The cavity volume is determined by the upper punch 16 as shown in FIG.
When the molten metal continues to enter the cavity lo, the molten metal inside the j is increased to the extent that it does not spill out. Note that the lower bunch 8 is at its lower limit position when the upper bunch 16 completely enters the cavity IO, so the upper punch 16
As a result, when the upper ff115 is further lowered, the bushing rod z1 will retreat into the air chamber 20 against the internal pressure of the bushing rod z1, as shown in FIG.

The upper bunch 16 is placed on the spacer 18 provided on the upper die 15.
is lowered until it contacts the stopper 19, so that it completely enters the cavity 10 without spilling the molten metal, and the molten metal in the cavity is spread over its entirety and is sufficiently high. Pressurized directly.

Note that the amount of molten metal in the cavity 10 is preselected to be somewhat larger than the required amount, so when the upper bunch 16 completely enters, the molten metal pressure will be higher than the required value, and this In this case, the piston 9, to which the molten metal at the required pressure has been pulled up counter-loaded (with a force equal to the force exerted on the lance piston 9), is moved downward to a position where the force exerted on it by the molten metal and the back-up force are balanced. The excess molten metal flows out into the space of the lower bunch 8 formed by this downward movement, as shown in FIG. 8.

Due to this outflow of the molten metal, the internal pressure of the molten metal becomes the predetermined value again, so by solidifying the molten metal in this state, an excellent casting without casting defects can be obtained. Here, the volume shrinkage due to solidification of the molten metal is compensated for by the outflowing molten metal 1 which is pressurized with a predetermined force by the counterbalance piston 9.

After that, the product W, in which the process 9 is also reduced by solidifying the molten metal under such a neutral pressure state, is produced in the liquid chamber 4a of the double-acting cylinder number, as shown in FIG. 8 and the left half of FIG. For example, by supplying pressure oil to the lower mold 1.

By lowering it until it contacts the lower limit stopper 6, the lower bunch 8 and the counterbalance piston 9
It is exposed from the cavity 10 while being supported by. The exposure process for the product WO involves exposing the periphery of the lower die through hole 20 and the product W.
This is done by moving the lower mold 1 in the direction of gravity acting on it against the contact resistance, so the power consumption for this is small and the product W is not damaged. .

Finally, the product W is produced based on the rise of the upper mold 15.
Lifted while attached to the upper punch 16・172-
In this example, due to the action of the ejector turbine 17 operated near the upper limit of its rise, it is separated from the upper punch 1G.
7 completes the removal of the product from the device. Here, during this lifting process of the product W, since the product W has been exposed from the cavity 10 in advance in the previous process, it is possible to significantly reduce the power consumption. As the damage is reduced, the damage will also be effectively prevented.

On the other hand, the lower mold 1, the lower bunch 8 and the counterbalance piston 9 are returned to their initial positions while the upper punch 16 is rising, and there they wait for the next hot water supply.

Therefore, when it comes to molten metal forging using this device, it is possible to supply a constant amount of molten metal into the cavity, and the high pressure and pressure of the molten metal is effective, there are no casting defects, and the amount of machining required for the product is small. Cast iron was introduced,
Furthermore, the power consumption when taking out the product W is low,
Further, the product W will not be damaged when it is taken out.

FIG. 5 is a sectional view showing another embodiment of the device of the present invention,
In this example, an overflow groove 23 for molten metal is provided adjacent to and around the through hole 2 of the lower mold l.

By causing the molten metal supplied into the cavity 10 to overflow there, the molten metal in the over 70-groove 28 heats and keeps the lower part 1 warm, and effectively prevents the molten metal in the cavity from solidifying halfway. be.

As a result, the upper punch 16 can always reliably apply the desired pressing force to the entire molten metal before it starts to solidify. Then, the molten metal solidified in the groove z8 is taken out from there during the star rotation of the upper and lower molds 15, 1 by the action of the ejector turbine 24, which penetrates the downward swing 1 and whose upper end reaches the over 70-groove 28. It turns out.

Other operations in this example are similar to those of the previously described device. - Although the present invention has been described above based on the illustrated examples, the shapes and dimensions of the cavity 10 and the upper punch 16 can be changed depending on the product, and the configurations of the various stoppers in the figures can be changed depending on the device. It can be changed as appropriate depending on the configuration. Furthermore, the means for lifting and lowering the lower bunch 2 is replaced by a gear mechanism or other reciprocating means, and the air chambers 11 and 20 are replaced by elastic means such as rubber, rubber-like elastic bodies, air springs, etc. It is also possible to do this.

〔Effect of the invention〕

Therefore, according to the method of the present invention, the amount of molten metal supplied into the cavity is always constant, so that the desired molten metal pressurization pressure can be applied reliably, and the occurrence of defects in the product can be sufficiently effectively prevented. become. On the one hand, this constant supply of molten metal
It is possible to reduce the amount of machining required for the product and to improve the yield of the molten metal. Here, the molten metal in the cavity is pressurized entirely and directly with a sufficiently large force by the lowering of the upper punch, so that the quality of the product can be made homogeneous throughout, and the melt can be chilled. Contamination can be reliably prevented. Furthermore, by taking out the product by lowering the lower die and raising the upper punch, the product can be easily taken out with less power consumption and without damaging the product.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the device of the present invention. 2 to 4 are process diagrams showing the operating state of the apparatus shown in FIG. 1, respectively. FIG. 5 is a sectional view showing another embodiment of the device of the present invention. 1... Lower cover 2... Through hole 4... Reciprocating drive means 8... Lower punch 9... Counter balance piston 10... Cavity 15... Saturn 162
- Upper bunch 18... Spacer 19... Stopper. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A step of supplying molten metal into a cavity formed by a lower mold, a lower punch, and a counterbalance piston until the cavity is filled, and lowering the lower punch to reduce the cavity volume. and pressurizing the molten metal in the cavity at a predetermined pressure by pushing an upper punch having a contour corresponding to the planar contour of the cavity into the cavity, while forming excess molten metal by lowering the counterbalance piston. A molten metal forging method that sequentially combines the steps of releasing the molten metal into a space where the molten metal is solidified, lowering the lower mold to expose the product after solidifying the molten metal, and removing the product with an upper punch. 2. A lower mold (1) having a through hole (2) with a predetermined contour, a lifting means (4) for driving the lower mold (1), and a through hole (2)
), and a lower punch (8) that is driven up and down within a certain range, and a counterbalance piston (9) that is backed up by a predetermined force and positioned at the upper limit position;
A cavity (10) is fixed to the upper die (15), has a contour corresponding to the through hole (2), and is formed by the lower die (1), the lower punch (8) and the counterbalance piston (9). Upper punch raised and lowered against the opponent (16)
and a stopper (19) for specifying the lower limit position of the upper punch (16).