JPH0739925A - Extrusion method - Google Patents

Abstract

PURPOSE:To greatly improve the yield of extruded products by starting to bring a container into contact with a die just before completion of upset. CONSTITUTION:Container cylinders 33 are provided on an end platen 32 and a container tire 2 and container 1 are slid with the cylinders. Air between the container 2 and a billet 13 is evacuated before starting the extrusion of the billet 13. At this time, before the container 1 is brought into contact with the die 3, the container 1 is temporarily stopped by a temporarily stopping mechanism A. And the air which remains on the side of the die 3 in the container 1 is discharged from a gap 6 which is made by without bringing the end face of the die 3 into contact with the end face of the container 1 on the side of the die 3 and also the container 1 is started to contact with the die 3 just before completion of upset. In this way, the air which remains in the evacuating space in the container is almost completly discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention discharges air between a container and a billet to the outside of the container before extrusion of the billet from inside the container through a die during extrusion molding of an aluminum alloy or the like by an extrusion press. The present invention relates to an improved degassing method in an extrusion container for effectively extruding a billet without containing air.

[0002]

2. Description of the Related Art After a billet having a diameter slightly smaller than the inner diameter of the container is placed in the container, the billet is pressed against the die with the stem at the rear in the container, so-called upsetting, the billet is crushed and the air between the container and the billet is crushed. Is compressed. In order to release the compressed air, the stem and the container are slightly retracted, the compressed air is discharged from the gap between the die and the container, and the container and the stem are advanced again to start extrusion. The degassing process for removing the compressed air in this way is called a burp cycle, and the existence of this process causes wasteful time in the extrusion cycle.

Further, according to this method, when deaeration is carried out by the barp cycle and the container is pressed against the die, air remains at atmospheric pressure between the inner surface of the container and the outer surface of the billet in a thin state of about one skin. However, sufficient deaeration has not been performed. Further, aluminum dust often adheres to the container liner end surface and the die end surface. If it adheres in a uniform film shape, there should be no air intrusion when it is sealed, but generally, the residue adheres unevenly. For this reason, even if the inside of the container was degassed, even if air entered again and a burp cycle was carried out by the time the upsetting of the billet was completed, the blister was generated.

Therefore, recently, for example, Japanese Laid-Open Patent Publication No. 3-4.
As described in Japanese Patent Publication No. 13, a pressure pad and a hollow extrusion stem are used at the tip of the stem in order to remove air from the stem side, and it is also considered to remove air during billet extrusion.

[0005]

However, in the air venting described above, even if the air on the stem side is released during pressurization of the billet, most of the air in the container and the billet, especially on the die side, is difficult to escape.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to discharge all the air in the container before extruding the billet in the container. The purpose of the present invention is to provide a container sealing and to provide an extrusion cycle that does not require the above-mentioned degassing step called a burp cycle before extruding a billet from a die.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and when the air between the extruding container and the billet is degassed before starting the extrusion of the billet, the container is removed. Before contacting the die, the container is temporarily stopped by the temporary stop mechanism, and the air accumulated on the die side in the container is released from the gap created by not contacting the die end surface and the die side end surface of the container, Immediately before the upset is completed, the container should start contacting the die.

[0008]

When the billet in the container is pushed by the stem behind the billet and the billet is pressed against the die, the billet is crushed and the air between the container and the billet is compressed. This compressed air must be released to the outside before the billet is pushed out of the die. When air is discharged from the die side of the container, air is discharged through a minute gap between the die and the container during the upset process by advancing the extrusion stem, and the container and die are brought into contact (container seal) immediately before the upset is completed. .
This minute interval is maintained by temporarily stopping the container cylinder.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a vertical cross-sectional view showing an embodiment of an apparatus for carrying out a degassing method in an extrusion container according to the present invention, FIG. 2 is an operation explanatory view of a temporary stop mechanism provided in a container cylinder, and FIG. Is a conceptual diagram showing how the billet crushed in the container collapses, and FIG. 4 shows the billet pushing pressure and extrusion stem velocity curve from the start to the end of upset.

As shown in FIG. 2, a portion A on the piston head side of the container cylinder 33, which is installed on the end platen 32 of FIG. 1 and slides the container tire 2 and the container 1, has a moving stopper block 34 as its main portion. The head block 35 also serves as a stopper, and the piston 37 can be rapidly stopped at the maximum distance S within the range in which the movement stopper block 34 moves. In FIG. 2, 36 is a cylinder tube forming a part of the cylinder body, 35 is a head block at the rear of the cylinder body, 37 is a piston, and 38 is a piston rod. Piston rod 3
A hollow rod 40 having a plurality of oil passage holes 39 arranged in a zigzag pattern in the axial direction is integrally attached to the rear shaft center portion of the rear piston 8 on the head side of the piston 8 by screws or the like.

Inside the head block 35 of the cylinder, there is a stopper block 34 which can move in the S-axis direction in the cylinder axis direction.
Is provided slidably, and a hole 41 is provided in the shaft center portion of the stopper block 34 so that the hollow rod 40 can be slidably inserted. The stopper block 34 includes a piston portion 34a and a rod portion 34b facing the piston 37 side.
The oil passage 42 is provided in a part of the piston portion 34a, the oil passage 42 penetrating in the radial direction and communicating with the rear portion of the hole 41.

Reference numeral 43 designates a piston 37 and a head block 35.
And the oil chamber 43 between the stopper block 34 and the oil chamber 43.
Oil inlet / outlet to the oil chamber, 45 is an oil chamber between the front surface of the rear wall formed by the plug of the head block 35 and the rear surface of the stopper block 34, 46 is a passage in the head block 35 communicating with the oil chamber 45, 47 Is a passage in the head block 35 that communicates with the passage 42.

Hydraulic oil can be supplied to or discharged from the oil inlet / outlet 44 to the oil chamber 43, the passage 46 communicating with the oil chamber 45, and the passage 47 communicating with the passage 42, respectively, through conduits 48, 49, 50. I did it. Reference numeral 51 is a valve having a flow rate adjusting valve 52 and a check valve 53 provided in parallel in the pipe 50, and 54 is a solenoid SOL. An electromagnetic switching valve having A,
55 is a pilot check valve provided in the pipeline 49, 56
Is a solenoid SOL. B is an electromagnetic switching valve, 57 is a relief valve provided in the conduit 48, and 58 is a solenoid SO
L. An electromagnetic switching valve having C, 59 is a tank, which are connected as shown in FIG. 2, and one of the conduits 48 is connected to the container cylinder 33 via an electromagnetic switching valve for forward / backward movement (not shown). It is connected to a pump not shown.

Reference numeral 3 is a die, and the outer periphery of the die 3 is slidably fitted and held on the inner peripheral surface of the die ring 5. Reference numeral 6 denotes a gap, and a gap 6 of, for example, 2 to 3 mm is formed between the container 1 and the die 3 or die ring 5 by a temporary stop mechanism provided in the container cylinder 33. Reference numeral 31 denotes a gap between the inner peripheral surface of the container and the outer peripheral surface of the billet 13, which is also a deaeration space.

On the other hand, an extruding stem 14 for pushing the billet 13
A fixed damy block 15 that can be brought into close contact with the inner surface of the container 1 is provided at the tip of the container. The fixed damy block 15 is a dami block rear member 17 fixed to the tip of a rod-like member 16 fixedly provided on the axial center of the extrusion stem 14 by a screw, and the outer periphery of the tip of the rear member 17 is screwed. It is an outer ring 18 which is attached and whose front end portion can spread in the outer diameter direction and come into close contact with the inner peripheral surface of the container 1. In addition, 14a is a stem holder and 14b is a crosshead.

Next, the operation of the device will be described.
First, the container 1 is moved forward to raise a billet loader (not shown) with a gap 6 of 2 to 3 mm between the container 1 and the die ring 5. Next, the billet 13 is put into the container 1 by the action of the extrusion stem 14, and hydraulic oil is applied to the front surface of the piston 37 through a hydraulic circuit (not shown) to retract the piston 37 (FIG. 2).
(1)). At this time, the extrusion stem 14 is also advanced at the same time. At this time, the hollow rod 40 attached to the piston 37
When the front end E of the SOL. B is ON, SOL. A is OFF, S
OL. C is OFF, and the retreating speed of the piston 37 is relatively high. At this time, since the pilot check valve 55 acts as a check valve, the stopper block 34 is at the forward limit position as shown in FIG. When the piston 37 retreats at high speed, most of the oil in the oil chamber 43 is discharged through the pipe line 48, but a part of the oil is discharged through the hole 41, the passages 42, 4 and 4.
It can be discharged to the tank 59 through the pipe line 50, the flow rate adjusting valve 52, and the electromagnetic switching valve 54.

When the tip E of the hollow rod 40 reaches the tip F of the stopper block 34, SOL. B is O
N, SOL. A remains OFF and SO
L. Switch C to ON. Then, the relief valve 57
Is activated and a little pressure is generated in the pipe 48, and the piston 3
Since 7 becomes a little low speed, pressure starts to be applied to the discharge from the inlet / outlet port 44.

While the hollow rod 40 begins to enter the hole 41 and the tip surface portion D of the piston 37 moves to the tip portion F of the stopper block 34, the SOL. B is ON,
SOL. C is ON, SOL. A is off. Then, the communication holes 39 for oil passage are closed one after another, and the hydraulic pressure in the oil chamber 43 is smoothly increased, so that the piston 37
The reverse speed of is also reduced. In this state, the piston 37 continues to retreat, and the tip surface portion D of the piston 37 contacts the tip portion F of the stopper block 34. At this time, the piston 37
The action of the stopper block 34 completes the halfway stop. Then, due to the action of the stopper block 34, the accuracy of the stop position during the stroke is sufficiently ensured. At this time, the gap 6 between the container 1 and the die 3 is, for example,
It is 2-3 mm. The state at this time is shown in FIG. At this time, as shown in FIG. 1, there is air in the deaeration space 31 between the container 1 and the billet 13.

When this operation is completed, the billet 13
The billet loader (not shown) rises with the
When the extrusion stem 14 is moved forward, the billet 13 is pushed into the container 1 and the billet 13 comes into contact with the end surface of the die 3 side. Further, the extrusion stem 14 advances and the upset is started (FIG. 3 (1)). If this state is continued, the air in the deaeration space 31 is sucked from the die 3 side by the action of the vacuum tank 10 when the billet 13 on the extrusion stem 14 side comes into close contact with the container 1. As shown in FIGS. 3 (1), (2), and (3), the degassing space 31 between the container 1 and the billet 13 is extruded by the extrusion stem 14 so that the billet 13 is sequentially pressed in the die 3 direction from S ₁ to S _3. If it is done, it can be seen that this deaeration space 31 is pushed into the die 3 side. This state will be described in more detail with reference to FIG. 4. At the start of upset, pressure oil is supplied to a side cylinder (not shown) to crush the billet 13 while advancing the extrusion stem 14 at a constant speed (V ₁ ), and the billet 13 is pushed in. When the pressure reaches P ₁ , the side cylinder is switched to the main cylinder (not shown), and the extrusion stem 14 is decelerated and advanced.

After that, the extrusion stem 14 is moved forward again at a constant velocity (V ₂ ) without rest, and when the pushing pressure of the billet 13 reaches P ₂ , the extrusion stem 14 is further decelerated and then at a constant velocity (V ₃ ) Move forward. Billet 1 after upset starts
The pushing pressure of 3 continues to increase gradually, and when the pushing pressure reaches P ₃ , the container seal (contacting the die 3 and the container 1) is started, and when it reaches P ₄ , the upset is completed and the container seal is also completed. Allow (Fig. 3
(4)). After completion of the upset, the product is extruded from the die 3 at the extrusion speed (V ₄ ).

In this way, immediately before the completion of upsetting, the container 1 advances toward the die 3 side and the container 1 and the die 3
The gap 6 becomes zero. The reduction of the gap 6 is due to the backward movement of the movement stopper block 34 shown in FIG. That is, when the piston 37 is further retracted, the SOL. SOL. B and S
OL. C is also turned off. Then, the solenoid switching valve 56
Is switched, and pilot pressure PP is passed through the electromagnetic switching valve 56.
Acts on the pilot check valve 55 and the check function disappears, so that the working oil in the oil chamber 45 is discharged through the pilot check valve 55. Further, the electromagnetic switching valve 58 is also switched, and the set pressure of the relief valve 57 becomes 0 kg / cm ² and communicates with the tank 59, so that the hydraulic oil in the oil chamber 43 is easily discharged. Therefore, the stopper block 34 is pushed by the piston 37 and retracts. Then, as the stopper block 34 moves rearward, the tip end surface portion D of the piston 37 moves from the tip end portion F of the stopper block 34 to G,
The piston 37 completes the backward movement.

When advancing the piston 37,
SOL. B remains OFF, and SOL. A is ON,
SOL. Turn on C. SOL. B to ON, SOL.
A OFF, SAOL. When C is turned off, the stopper block 34 returns by hydraulic pressure and returns to the position shown in FIG. In this embodiment, as a result of repeating various repeated experiments using an extrusion press device for an aluminum sash, an idle time of about 4 seconds can be shortened, and there is an advantage of adopting a high speed double head puller. Further, in this example, the occurrence of blisters in the extruded product could be reduced to almost zero without performing the burp cycle.

[0023]

As is apparent from the above description, according to the extrusion molding method of the present invention, when the air between the extrusion container and the billet is degassed before the extrusion of the billet is started. Before the container is brought into contact with the die, the container is temporarily stopped with a container cylinder that has a temporary stop mechanism so that the end face of the die and the end face of the die side of the container do not come into contact with each other and accumulate on the die side in the container. Air is released and the container is brought into contact with the die immediately before the upset is completed, so that the air remaining in the degassing space inside the container is almost completely removed from the die until the billet is upset in the container. Can be discharged. And
In addition to the reduction of burp cycles, the high-speed extrusion press can be achieved by establishing a technology to quickly stop the container using a container cylinder. Further, since the vacuum device is not used for deaeration of the air staying in the deaeration space, the device is simplified and it is easy to approach the device. Further, since the air staying in the degassing space can be almost completely discharged naturally and the occurrence of blisters can be suppressed to a low level, the yield of extruded products is greatly improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of an apparatus for carrying out a degassing method in an extrusion container according to the present invention.

FIG. 2 is an operation explanatory view of a temporary stop mechanism provided in the container cylinder.

FIG. 3 is a conceptual diagram showing how to collapse a billet pressurized in a container.

FIG. 4 is a push-in pressure and extrusion stem velocity curve of a billet from the start to the end of upsetting.

[Explanation of symbols]

 1 Container 3 Dice 4 Die Ring Seal Ring 5 Die Ring 6 Gap 13 Billet 14 Extrusion Stem 15 Fixed Damy Block 18 Outer Diameter Ring 31 Deaeration Space 33 Container Cylinder 34 Movement Stopper Block 35 Head Block 37 Piston 39 Connecting Hole 40 Hollow Rod 41 holes 48, 49, 50 pipeline 51 valve 52 flow rate adjustment valve 53 check valve 54, 56, 58 electromagnetic switching valve

Claims (1)

[Claims] 1. Air between the extrusion container and the billet,
When degassing before starting the billet extrusion, a gap created by temporarily stopping the container with the temporary stop mechanism before contacting the container with the die so that the die end face and the die side end face of the container do not contact The extrusion molding method is characterized in that the air accumulated on the die side in the container is discharged from the container and the container is started to contact with the die immediately before the upset is completed.