JPH07275927A - Deaerating method inside extrusion container - Google Patents

Abstract

PURPOSE:To contrive complete deaeration inside a container before starting extrusion by providing a vacuum assisting valve integrally with a hydraulic switching valve in the middle of piping between a container and a vacuum pump and abutting the container on a die through the detection of a vacuum state. CONSTITUTION:An end face of a container 1 is stopped with a clearance 6 between the end face and a die ring 5, a billet 13 is inserted with an extruding stem 14 with a tip end abutted on a die 3. Simultaneously, an exit of a vent is opened by an air actuator 25. In addition, when the extruding stem 14 is advanced to start upsetting, and a billet 13 on the side of the extruding stem 14 enters into close contact to the container 1, the air in a deaerating space 31 is sucked from a die 3 side. When the inside of the container 1 is filled with the billet 13 with the degree of the vacuum approaching 0Torr, a spring 45 is pressed downward by the piston 44 of a vacuum assisting valve 42. When the piston 44 is lowered to a protrusion part 43a, a hydraulic switching valve 47 is switched, and the container 1 is pulled to the die 3 side by a cylinder 33, closing the clearance 6 and stopping the suction of the remaining air. Then, successively, extruding is commenced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extruding a billet by an extrusion press of aluminum alloy or the like. Before the billet is extruded from inside the container through a die, air between the container and the billet of the container is discharged. The present invention relates to a degassing method in an extruding container for discharging blisters in an extruded product.

[0002]

2. Description of the Related Art After a billet having a diameter slightly smaller than the inner diameter of the container is put in the container, the billet is pushed by the stem behind the billet and pressed against the die in the container. The air in between is compressed. In order to release this 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, but this process causes a waste of time in the extrusion cycle.

[0003]

However, in order to eliminate the dead time due to the conventional barp cycle, when an attempt is made to remove residual air from the die end of the container by a vacuum pump, the space between the inner surface of the container and the outer surface of the billet is reduced. However, there is a problem that air remains at atmospheric pressure in a thin state of about one skin, and it is difficult to perform sufficient deaeration.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a degassing method in an extrusion container in which the inside of the container is completely vacuum degassed before starting the billet extrusion. Especially.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and when the air between the extrusion container and the billet is degassed before starting the extrusion of the billet, the container is temporarily suspended. This is a degassing method in the extrusion container in which the container is temporarily stopped by the stop mechanism so that the end face of the die and the end face of the die on the die side do not come into contact with each other, and the air stored in the container is sucked and discharged from the gap. Then, in the middle of the pipe for sucking and discharging the air stored in the container by the vacuum pump, a spring is mounted between the lower end of the piston that is engaged with the cylinder forming the vacuum assist valve and moves up and down, and the cylinder. An opening for exposing the upper end of the piston to the outside air at all times is provided in the upper region of the piston, and a first hydraulic pressure switching valve is connected to the upper end of the piston, When the inside of the container reaches near vacuum, the piston is pushed downward due to the pressure difference between the piston and the outside air acting on the upper end of the piston to switch the first hydraulic pressure switching valve, so that the pressure oil is transferred to the rod side of the container cylinder. A second hydraulic pressure switching valve for supplying / discharging and a third hydraulic pressure switching valve for supplying / discharging pressure oil on the head side of the container cylinder at the same time,
The container is closed again by advancing the container again from the paused state of the container.

[0006]

According to the above construction, when the air between the extrusion container and the billet is degassed before the extrusion of the billet is started, the container is temporarily stopped by the temporary stop mechanism. A first hydraulic pressure switching valve that is integrally formed with the vacuum assist valve is provided in the middle of the piping from the container to the vacuum pump, and when the inside of the piping becomes a vacuum, the first hydraulic pressure switching valve is switched and at the same time the suspension is performed. Since the second hydraulic pressure switching valve and the third hydraulic pressure switching valve are operated so as to release the state and bring the container into contact with the die, the container can be completely degassed in vacuum and a product without blisters can be easily obtained. To be

[0007]

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 sectional view showing an embodiment of an extruding container degassing apparatus according to the present invention, FIG. 2 is an explanatory view showing a state before the extrusion of a billet is started, and FIG. 3 is a diagram immediately after starting degassing in a container. FIG. 4 is an explanatory view showing a state, FIG. 4 is an explanatory view showing a state immediately before the completion of degassing in the container, and FIG. 5 is a conceptual diagram showing how the billet pressed in the container is crushed.

The B block on the piston head side of the container cylinder 33 for sliding the container tire 2 and the container 1 installed on the end platen 32 of FIG. 1 is a moving stopper block 34 and a head block 35 also serving as a stopper.
The piston 37 temporarily stops the end surface of the container 1 on the side of the die 3 on the side of the die 3 with a gap of, for example, about 2 to 3 mm at a maximum distance within a range in which the movement stopper block 34 moves. Mechanism 30
It has a structure with. In FIG. 1, 36 is a cylinder tube which constitutes a part of the cylinder body, 35 is a head block at the rear of the cylinder body, 37 is a piston, 3
8 is a piston rod.

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, the extrusion stem 1 for pushing the billet 13
A fixed damy block 15 which can be brought into close contact with the inner surface of the container 1 is provided at the tip of the container 4. The fixed damy block 15 is a damy block rear member 17 fixed to the tip of a tubular member 16 fixedly provided on the shaft core of the extruding 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, 14b
Is a crosshead.

In the present embodiment, as shown in FIG. 2, an annular concave portion 24 which is concentric with the container 1 is formed on the end surface of the container tire 2 on the side of the die 3, and an air actuator 25 is provided in the outer peripheral direction of the annular concave portion 24. Are arranged at equal intervals (16 in this embodiment). A seal ring 11 concentric with the container 1 is fixed to a rod 25a of the air actuator 25, and the seal ring 1 is moved forward and backward as the piston 25b of the air actuator 25 moves forward and backward.
1 is provided so as to be able to move forward and backward in the extrusion direction.

By moving the piston 25b forward and backward, the seal ring 11 is pressed against the die 3 side to open and close the degassing port outlet 40 which communicates with the degassing space 31. The residual air in the container 1 sucked through the degassing outlet 40 is sucked and discharged from the degassing duct 8 arranged in the seal ring 11.

On the container 1 side of the annular recess 24,
A spring 26 is elastically mounted between the seal ring 11 and the annular recess 24 so as to constantly extend the seal ring 11 toward the die 3.

There are two slit-shaped deaeration holes 7 as shown in FIG. 2 above the seal ring 11, and they are connected to a vacuum tank 20 and a vacuum pump 21 via a duct 8 and an electromagnetic switching valve 9. ing. 22 is a motor.

In the embodiment according to the present invention, another air vent pipe 41 is connected to the duct 8 and an extrusion container automatic closing operation device is arranged at an end of the air vent pipe 41.

The vacuum assist valve 42, which is one of the automatic closing devices for the extrusion container, comprises a cylinder 43, a piston 44 and a spring 45. On the inner wall surface of the cylinder 43, a convex portion 43a for restricting the lower limit of the piston 44 is provided, and the lower end portion of the piston 44 and the cylinder 43 are arranged.
A spring 45 is mounted in between.

A rod 46 is provided at the center of the upper end of the piston 44.
The first hydraulic pressure switching valve 47 is fixed via the. Also,
An opening portion 48 having a diameter larger than that of the rod 46 is provided on the upper portion of the cylinder 43 so as to be sufficiently loosely fitted to the rod 46, and the opening portion 48 is always exposed to the outside air (atmospheric pressure). ing.

An opening 48 is formed at the upper end of the piston 44.
The atmospheric pressure always acts on the piston 44, and the lower end portion of the piston 44 is changed from the atmospheric pressure to the vacuum state by the vacuum action of the vacuum pump 21. With such a structure, when the lower end portion of the piston 44 becomes close to a vacuum, the atmospheric pressure acting on the upper end portion side of the piston 44 causes the piston 44 to move.
Is configured to overcome the extension force of the spring 45 and be pushed downward.

Thus, when the piston 44 overcomes the extension force of the spring 45 and moves down to the position where it abuts on the convex portion 43a of the cylinder 43, the first hydraulic pressure switching valve 47 is configured to switch to the state shown in FIG. ing.

When the first hydraulic pressure switching valve 47 is switched, a second hydraulic pressure switching valve 49 for supplying / discharging pressure oil to / from the piston rod 38 side of the container cylinder 33, and a piston head 39.
The third hydraulic pressure switching valve 50 for supplying and discharging the pressure oil on the side is also configured to switch at the same time.

Reference numerals 52, 53, 54, 55 and 56 are tanks, 57 is a hydraulic pump, 58 is a relief valve,
Reference numerals 59 respectively indicate electromagnetic switching valves.

Next, a method of degassing the inside of the extrusion container using the extrusion press will be described.

First, the end surface of the container 1 on the die side is stopped with the die ring 5 surface having a gap 6 of, for example, about 2 to 3 mm. Under this condition, the electromagnetic switching valve 9 and the electromagnetic switching valve 59 are turned off (demagnetized state). The piston 44 of the vacuum assist valve 42 is at the upper limit position, and the second
The hydraulic pressure switching valve 49 and the third hydraulic pressure switching valve 50 are blocked.

In this state, the billet 13 is placed in the container 1.
Is loaded by the forward movement of the extrusion stem 14, and the tip end surface of the billet 13 is applied to the die 3. This state is shown in FIG. At this time, air is present in the deaeration space 31 between the container 1 and the billet 13.

At the same time, as shown in FIG. 2, compressed air or the like is introduced to the head side of the piston 25b of the air actuator 25 to move the piston 25b forward so that the seal ring 11 is separated from the end surface of the container tire 2 and the deaeration port is opened. The outlet 40 is left open.

When this operation ends, 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 to start upset. 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 20 when the billet 13 on the extrusion stem 14 side comes into close contact with the container 1. At this time, the sucked air on the side of the die 3 passes through the gap 6 and the deaeration hole 7 provided in a part of the seal ring 11 attached to the container 1, and from there, the duct 8 is provided on the upper surface of the container 1. It is led to the electromagnetic switching valve 9.

The inside of the piping up to the vacuum tank 20 and the electromagnetic switching valve 9 is evacuated to, for example, 5 to 10 torr, and the electromagnetic switching valve 9 is opened at the same time when the billet 13 and the die 3 come into contact with each other and the seal ring 11 is closed. The deaeration space 31 is quickly and sufficiently deaerated through the deaeration hole 7.

After this, the extrusion stem 14 continues to move forward without rest, and the billet 13 is crushed. The crushed state is shown in FIG. In these drawings, if the degassing space 31 between the container 1 and the billet 13 is sequentially pressurized by the extrusion stem 14 in the die direction from S ₁ to S ₃ , the degassing space 31 will be the degassing space 31. It can be seen from Fig. 5 that it is pushed in. Deaeration is, for example, about 10 to 50 to
It can be performed in about 0.5 seconds with a vacuum degree of rr.

Even after the start of degassing by suction, the extrusion stem 14
Continues to move forward, crushing the billet 13. Then, when the billet 13 is filled in the container 1 and the upset is completed, the degree of vacuum becomes a value close to zero torr.

The duct 8, the air bleeding pipe 41, and the vacuum assist valve 42 are set to the above-mentioned zero t from the atmospheric pressure state before vacuum deaeration.
When degassed by vacuum suction to orr, piston 44
Is overcome by the atmospheric pressure acting on the opening 48 and is pressed downward by overcoming the extension force of the spring 45.

Cylinder 43 with piston 44 at the lower limit
When pushed down to the convex portion 43a, the first hydraulic pressure switching valve 47 switches (state of FIG. 4). Therefore, the pressure oil (PP) from the hydraulic pump (not shown) moves on the spools of the second hydraulic pressure switching valve 49 and the third hydraulic pressure switching valve 50, and switches to the state shown in FIG.

Second hydraulic pressure switching valve 49 and third hydraulic pressure switching valve 50
By the switching of the above, pressure oil is supplied from the hydraulic pump 57 to the piston rod 38 side of the container cylinder 33, and at the same time, the piston head 3 of the container cylinder 33 is changed.
The pressure oil on the 9 side is discharged to the tank 52.

By supplying the pressure oil to the piston rod 38 side of the container cylinder 33 in this way, the container 1 is drawn toward the die 3 side and the end surface of the die 3 and the end surface of the container 1 come into contact with each other, and the vacuum pump 21 degasses them. The suction of the residual air from the mouth outlet 40 is stopped. At this time, the electromagnetic switching valve 9 is demagnetized. Next, the extrusion is continued, and the blister-free product is extruded from the die 3.

When the extrusion of the desired product without blisters from the die 3 is completed, the extrusion stem 14 is retracted by a side cylinder (not shown), and the container cylinder 3 is continued.
The pressure oil from a hydraulic pump (not shown) is introduced to the piston head 39 side of 3 to retract the container 1 and separate it from the die 3.

When the container 1 is separated from the die 3, outside air enters the duct 8, the air vent pipe 41, and the vacuum assisting valve 42, and the degree of vacuum is lost. Therefore, the piston 44
Is pushed up to the upper limit of the cylinder 43 by the extension force of the spring 45, the first hydraulic pressure switching valve 47 is switched, and the second hydraulic pressure switching valve 49 and the third hydraulic pressure switching valve 50 return to the original state shown in FIG. Of.

[0037]

As is apparent from the above description, in the present invention, when the air between the extrusion container and the billet is degassed before the extrusion of the billet is started, the container is stopped by the temporary stop mechanism. Is a degassing method in an extrusion container in which the air stored in the container is sucked and discharged from a gap formed by temporarily stopping the die end surface and the die side end surface of the container to be in contact with each other. In the middle of the pipe that sucks and discharges the air stored in it by a vacuum pump, a spring is mounted between the lower end of the piston that goes up and down by engaging a cylinder that forms a vacuum assist valve and the cylinder, and is installed in the upper area of the cylinder. While providing an opening that always exposes the upper end of the piston to the outside air,
A first hydraulic pressure switching valve is connected to the upper end of the piston, and when the inside of the container reaches near vacuum, the piston is pushed downward due to a pressure difference from the outside air that acts on the upper end of the piston. 1) By switching the hydraulic pressure switching valve, the pressure oil is supplied to and discharged from the rod side of the container cylinder.
The hydraulic pressure switching valve and the third hydraulic pressure switching valve for supplying and discharging the pressure oil on the head side of the container cylinder are switched at the same time, and the container is closed again by advancing the container again from the temporarily stopped state. As a result, the degassing vacuum degree in the container is reliably detected, so that the timing of the container closing operation can be performed reliably and efficiently. Further, the reliability of the degassing / extruding operation in the container is improved, and the extruding of the product without blister can be surely performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an extrusion container deaerating device according to the present invention.

FIG. 2 is an explanatory diagram showing a state before the extrusion of the billet is started.

FIG. 3 is an explanatory view showing a state immediately after the start of deaeration in the container.

FIG. 4 is an explanatory diagram showing a state immediately before the completion of deaeration in the container.

FIG. 5 is a conceptual diagram showing how to collapse a billet pressurized in a container.

[Explanation of symbols]

 1 Container 2 Container Tire 3 Dice 6 Gap 7 Degassing Hole 8 Duct 9 Electromagnetic Switching Valve 11 Seal Ring 13 Billet 14 Extrusion Stem 14b Crosshead 15 Fixed Damy Block 20 Vacuum Tank 21 Vacuum Pump 25 Air Actuator 25a Rod 25b Piston 26 Spring 30 Temporary Stop Mechanism 31 Deaeration Space 32 End Platen 33 Container Cylinder 37 Piston 40 Deaeration Port Outlet 41 Air Vent Piping 42 Vacuum Assistance Valve 43 Cylinder 44 Piston 45 Spring 47 First Hydraulic Switching Valve 48 Opening 49 Second Hydraulic Switching Valve 50 Third hydraulic switching valve 57 Hydraulic pump 59 Electromagnetic switching valve

Claims (1)

[Claims] 1. When deaerating the air between the extrusion container and the billet before starting the extrusion of the billet, the container is temporarily stopped by a temporary stop mechanism so that the die end surface and the die side end surface of the container are A degassing method in an extrusion container that sucks and discharges the air stored in the container through a gap made so that it does not come into contact, and a pipe that sucks and discharges the air stored in the container by a vacuum pump A spring is mounted between the lower end of the piston that moves up and down by engaging with a cylinder that forms a vacuum assist valve and the cylinder, and an opening is provided in the upper region of the cylinder that constantly exposes the upper end of the piston to the outside air. At the same time, a first hydraulic pressure switching valve is connected to the upper end of the piston so that the outside air that acts on the upper end of the piston when the inside of the container reaches near vacuum. A second pressure-supplying / discharging pressure oil to / from the head side of the container cylinder by pushing down the piston by the pressure difference between
The hydraulic pressure switching valve and the third hydraulic pressure switching valve that supplies and discharges the pressure oil on the rod side of the container cylinder are switched at the same time, and the container is closed again by advancing the container again from the temporarily stopped state. A degassing method in an extrusion container characterized by: