JP2887890B2 - Degassing method in the extrusion container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of extruding a billet by an extrusion press of an aluminum alloy or the like, wherein air between the container and the billet is discharged before the billet is extruded from a container through a die. The present invention relates to a method for degassing inside an extrusion container, which is discharged outside so as to prevent 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 a container is placed in the container, the billet is pushed by a stem at the back of the billet and pressed against a die in a container. The air between them is compressed. In order to release the compressed air, the stem and the container are slightly retracted, the compressed air is removed from the gap between the die and the container, and the container and the stem are advanced again to start extrusion. The degassing step of removing the compressed air in this way is called a burp cycle, but the presence of this step causes wasted time in the extrusion cycle.

[0003]

However, in order to eliminate the dead time due to the conventional burp cycle, if an attempt is made to remove residual air from the tip of the container on the die side by means of 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-mentioned problems, and an object of the present invention is to provide a method for degassing an inside of an extrusion container in which the inside of the container is completely evacuated before starting the billet extrusion. It is in.

[0005]

DISCLOSURE 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 billet extrusion, the container is temporarily suspended. A deaeration method in an extruding container for sucking and discharging air stored in the container from a gap formed by temporarily stopping the container by a stop mechanism so that the die end surface does not contact the die side end surface of the container. In the middle of a pipe for sucking and discharging the air stored in the container by a vacuum pump, a spring is elastically mounted between the lower end of the piston which engages with a cylinder forming a vacuum assist valve and moves up and down and the cylinder. An opening is provided in the upper region of the piston so that the upper end of the piston is always exposed to the outside air, and a first hydraulic switching valve is connected to the upper end of the piston, and When the inside of the container reaches a vicinity of vacuum, a pressure difference between the piston and the outside air acting on an upper end portion of the piston is pushed downward to switch the first hydraulic switching valve, so that the pressure oil moves to the rod side of the container cylinder. Simultaneously switching a second hydraulic switching valve for supplying and discharging hydraulic fluid and a third hydraulic switching valve for supplying and discharging hydraulic oil on the head side of the container cylinder,
The container is moved forward again from the temporary stop state of the container to perform the closing operation of the container.

[0006]

According to the above construction, when the air between the extrusion container and the billet is degassed before starting the billet extrusion, the container is temporarily stopped by the temporary stop mechanism. A first hydraulic switching valve integrally formed with a vacuum assist valve is provided in the middle of the pipe from the container to the vacuum pump, and the first hydraulic switching valve is switched when the inside of the pipe becomes vacuum, and at the same time, the temporary stop is performed. The second hydraulic switching valve and the third hydraulic switching valve are operated so that the state is released and the container is brought into contact with the die, so that the container can be completely degassed under vacuum, and a product without a blister can be easily obtained. Can be

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a cross-sectional view showing one embodiment of an extrusion container degassing apparatus according to the present invention, FIG. 2 is an explanatory view showing a state before the start of billet extrusion, and FIG. FIG. 4 is an explanatory diagram showing a state immediately before the completion of deaeration in the container, and FIG. 5 is a conceptual diagram showing how a billet pressurized in the container is crushed.

A main part of a part B on the piston head side of a container cylinder 33 which is mounted on the end platen 32 of FIG. 1 and slides the container tire 2 and the container 1 is a moving stopper block 34 and a head block 35 also serving as a stopper.
At the maximum distance within the range in which the movement stopper block 34 moves, the piston 37 is temporarily stopped so that the end surface of the container 1 on the die 3 side can be rapidly stopped with a gap of, for example, about 2 to 3 mm from the die 3 surface. Mechanism 30
It has a structure having. In FIG. 1, reference numeral 36 denotes a cylinder tube constituting a part of the cylinder body, 35 denotes a head block at the rear of the cylinder body, 37 denotes a piston, 3
8 is a piston rod.

Reference numeral 3 denotes 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. Numeral 6 is a gap, and a gap 6 of, for example, 2 to 3 mm is provided between the container 1 and the die 3 or the 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 degassing space.

On the other hand, the extrusion stem 1 for pushing the billet 13
A fixed dam block 15 that can be in close contact with the inner surface of the container 1 is provided at the tip of the container 4. The fixed damage block 15 is a rear member 17 of a dummy block which is fixed to a distal end of a tubular member 16 fixedly provided on a shaft portion in the extrusion stem 14 by screws, and an outer peripheral portion of the distal end of the rear member 17 is screwed. An outer ring 18 that is attached and whose distal end portion can expand in the outer diameter direction and can come into close contact with the inner peripheral surface of the container 1. 14a is a stem holder, 14b
Is a crosshead.

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

The seal ring 11 is pressed against the die 3 by the forward / backward movement of the piston 25b, and is formed so as to open and close a deaeration port outlet 40 communicating with the deaeration space 31. The residual air in the container 1 sucked through the deaeration port outlet 40 is sucked and discharged from a deaeration duct 8 provided on 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 concave portion 24, and is configured to constantly extend the seal ring 11 toward the die 3.

Above the seal ring 11, there are two slit-shaped deaeration holes 7 as shown in FIG. 2, which are connected to a vacuum tank 20 and a vacuum pump 21 through 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 at the end of the air vent pipe 41, an automatic extrusion container closing device is provided.

The vacuum assisting valve 42, which is one of the devices for automatically closing 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 lowering limit of the piston 44 is provided.
A spring 45 is elastically mounted between them.

At the center of the upper end of the piston 44, a rod 46 is provided.
The first hydraulic pressure changeover valve 47 is fixed through the valve. Also,
The upper portion of the cylinder 43 has an opening 48 having a diameter larger than that of the rod 46 so as to exhibit a sufficient loose fit with the rod 46, and the opening 48 is always exposed to the outside air (atmospheric pressure). ing.

An opening 48 is provided at the upper end of the piston 44.
At all times, the atmospheric pressure is applied, and the lower end of the piston 44 is changed from the atmospheric pressure to a vacuum state by the vacuum action of the vacuum pump 21. With such a structure, when the lower end of the piston 44 is near the vacuum, the atmospheric pressure acting on the upper end side of the piston 44
Is configured to overcome the extension force of the spring 45 and be pushed downward.

When the piston 44 overcomes the extension force of the spring 45 and descends to a position where it comes into contact with the projection 43a of the cylinder 43, the first hydraulic switching valve 47 switches to the state shown in FIG. ing.

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

Numerals 52, 53, 54, 55 and 56 are tanks, 57 is a hydraulic pump, 58 is a relief valve,
Numeral 59 indicates an electromagnetic switching valve.

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

First, the die-side end surface of the container 1 is stopped in a state where there is a gap 6 of, for example, about 2 to 3 mm from the die ring 5 surface. In this state, the electromagnetic switching valve 9 and the electromagnetic switching valve 59 are kept OFF (demagnetized state). Note that the piston 44 of the vacuum assist valve 42 is at the upper limit position,
The hydraulic switching valve 49 and the third hydraulic switching valve 50 are set in a blocked state.

In this state, the billet 13 is put into the container 1.
Is charged 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 degassing space 31 between the container 1 and the billet 13.

At the same time, as shown in FIG. 2, for example, compressed air or the like is introduced into the head side of the piston 25b of the air actuator 25 to advance the piston 25b to separate the seal ring 11 from the end face of the container tire 2 to release the air. The outlet 40 is left open.

When this operation is completed, the billet 13
The billet loader (not shown) rises with
When the extrusion stem 14 is advanced, the billet 13 is pushed into the container 1 and the billet 13 comes into contact with the die 3 side end surface. Further, the extrusion stem 14 advances to start upset. When this state is continued, the air in the degassing 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, passes through the deaeration hole 7 provided in a part of the seal ring 11 attached to the container 1, and then passes through the duct 8 to the upper surface of the container 1 through the duct 8. It is led to the electromagnetic switching valve 9.

The piping between the vacuum tank 20 and the electromagnetic switching valve 9 is previously evacuated to, for example, 5 to 10 torr. When the billet 13 comes into contact with the die 3, the electromagnetic switching valve 9 opens and the seal ring 11 is closed. The degassing space 31 is quickly and sufficiently degassed through the degassing hole 7.

Thereafter, the extrusion stem 14 continues to move without rest, and the billet 13 is crushed. FIG. 5 shows the crushed state. In these figures, the container 1 and hopefully billet 13 in the die direction degassing space 31 is extrusion stem 14 between the billet 13 is pressed sequentially pressurized from S ₁ to S _3, the degassing space 31 is die-side It can be seen from FIG. Deaeration is, for example, about 10 to 50 to
It can be performed in about 0.5 seconds at a vacuum of rr.

After the suction and deaeration starts, the extrusion stem 14
Keeps moving forward without a break and crushes billet 13. 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.

From the atmospheric pressure state before vacuum deaeration in the duct 8, the air vent pipe 41 and the vacuum assist valve 42, the zero t
piston 44 when degassed by vacuum suction to orr
Is pressed downward overcoming the tension of the spring 45 by the atmospheric pressure acting on the opening 48.

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

Second hydraulic switching valve 49 and third hydraulic switching valve 50
As a result, the hydraulic 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
The pressure oil on the 9 side is discharged to the tank 52.

By supplying the pressurized oil to the piston rod 38 of the container cylinder 33 in this manner, the container 1 is drawn to the die 3 side, and the end face of the die 3 and the end face of the container 1 come into contact with each other, and the vacuum pump 21 deaerates. The suction of the residual air from the outlet 40 is stopped. At this time, the electromagnetic switching valve 9 is demagnetized. Next, extrusion is continued, and a product without blister is extruded from the die 3.

When the extrusion of the desired product without the blister from the die 3 is completed, the extruding stem 14 is retracted by the side cylinder (not shown).
The pressure oil from a hydraulic pump (not shown) is introduced into the piston head 39 of the container 3 and the container 1 is retracted and separated from the die 3.

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

[0037]

As is apparent from the above description, according to 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 temporarily stopped by the temporary stop mechanism. A deaeration method in an extrusion container for sucking and discharging air stored in the container from a gap formed by temporarily stopping the die end surface and the die side end surface of the container so as not to contact the container. In the middle of the pipe that sucks and discharges the air stored in the 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-assisting valve and the cylinder. With an opening that always exposes the upper end of the piston to the outside air,
A first hydraulic pressure switching valve is connected to an upper end of the piston, and when the inside of the container reaches a vicinity of vacuum, a pressure difference between the piston and the outside air acting on the upper end of the piston causes the piston to be pushed downward to lower the piston. (1) By switching the hydraulic switching valve, a second oil supply / discharge to the rod side of the container cylinder is performed.
The hydraulic switching valve and the third hydraulic switching valve for supplying and discharging the pressure oil on the head side of the container cylinder are simultaneously switched, and the container is moved forward again from the temporary stop state of the container to perform the closing operation of the container. Accordingly, the degree of degassing vacuum in the container is reliably detected, so that the timing of the container closing operation can be reliably and efficiently performed. Further, the reliability of the degassing and extruding operation in the container is improved, and the product without blister can be reliably extruded.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an extrusion container deaerator according to the present invention.

FIG. 2 is an explanatory view showing a state before the start of billet extrusion.

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

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

FIG. 5 is a conceptual diagram showing how a billet pressed in a container is crushed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Container tire 3 Die 6 Gap 7 Deaeration hole 8 Duct 9 Solenoid switching valve 11 Seal ring 13 Billet 14 Extrusion stem 14b Cross head 15 Fixed dam block 20 Vacuum tank 21 Vacuum pump 25 Air actuator 25a Rod 25b Piston 26 Spring Reference Signs List 30 Temporary stop mechanism 31 Deaeration space 32 End platen 33 Container cylinder 37 Piston 40 Deaeration port outlet 41 Air vent pipe 42 Vacuum assist 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 Solenoid switching valve

Claims (1)

(57) [Claims] When the air between the extrusion container and the billet is degassed before starting the billet extrusion, the container is temporarily stopped by a temporary stop mechanism so that the die end face and the die side end face of the container are moved. A deaeration method in an extrusion container for sucking and discharging air stored in the container from a gap formed so as not to be in contact with the container, wherein the air stored in the container is suctioned and discharged by a vacuum pump. A spring is mounted between the lower end of the piston that moves up and down by engaging with the cylinder forming the vacuum assist valve and the cylinder, and an opening is provided in the upper region of the cylinder to always expose the upper end of the piston to the outside air. In addition, a first hydraulic switching valve is connected to an upper end portion of the piston, and the outside air acting on the upper end portion of the piston when the inside of the container reaches a vicinity of vacuum. The pressure difference between the first hydraulic switching valve and the first hydraulic switching valve is switched downward by pressing the piston downward, thereby supplying and discharging pressure oil to the head side of the container cylinder.
The hydraulic switching valve and the third hydraulic switching valve for supplying and discharging the pressure oil on the rod side of the container cylinder are simultaneously switched to perform the closing operation of the container by moving the container forward again from the temporarily stopped state of the container. A degassing method in an extrusion container.