JPH05212435A - Extrusion press and its method - Google Patents

Abstract

PURPOSE: To provide an extrusion press and a method therefor capable of efficiently ejecting air while extrusing a billet. CONSTITUTION: This invention relates to an extrusion press to carry out an ejection cycle of the air accumulated between an extrusion die M and a slab b in a slab extrusion press. This extrusion press is equipped with a carrier 5 for the slab b, a plunger 2 having hydraulic cylinder/piston assembly 3, 4, and a first and a second hydraulic pressure pneumatic pressure accumulator 11, 15 to supply oil to an auxiliary hydraulic cylinder/piston assembly 6, 4 under a pressure to regulate a thrust force of the carrier 5 for the extrusion die M and a thrust force of the plunger 2 for the slab b.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method of performing a jetting cycle of air accumulated between a die and a billet in a billet extrusion press.

[0002]

2. Description of the Related Art A billet extrusion press is provided with a billet carrier which is reciprocable along the longitudinal direction of the extrusion axis of the billet extrusion press so as to come into contact with and separate from a die. And a plunger configured to reciprocate along the extrusion shaft so as to come into contact with and separate from the plunger. The billet carrier comprises an auxiliary hydraulic cylinder / piston assembly and the plunger comprises a main hydraulic cylinder / piston assembly in combination with a hydraulic cylinder / piston assembly. The billet extrusion press is also provided with a hydraulic oil transfer system extending between the pump means and the hydraulic cylinder / piston assembly.

A plunger is advanced relative to the billet to deform the metallic material forming the billet to extrude the billet into the billet carrier during the extrusion process of common metals, especially aluminum. It is necessary to eject the air trapped between the held metal billet and the extrusion die.

This is necessary because the trapped air reaches a very high pressure level such that the deformed metal does not pass through the die, leaving the extrusion press shut down overall.

The entire working cycle of an extrusion press is equipped with a conventional, auxiliary air jetting cycle, which continuously comprises stopping the extrusion press, interrupting the extrusion process,
It consists of depressurizing the hydraulic oil to the plunger, retracting the plunger, and retracting the carrier.

Such a cycle process includes a plunger,
And a suitable valve in the oil supply line to the hydraulic cylinder / piston assembly that drives the billet carrier and the plunger to be reversed.

The reverse motion of the plunger and carrier actually occurs over a distance of a few millimeters, and when the extrusion operation is restarted after the air ejection or similar vent cycle has begun, the carrier and plunger will It returns to the position before the stop.

[0008]

As a result, the operating time of the extrusion press for extrusion is the time it takes to return the extrusion press to the same conditions set for the air vent cycle before stopping the extrusion process. Increase with

This means that the predetermined configuration of the hydraulic system,
For example, a series of down times and operating transients in an extrusion press may extend the air vent cycle, including encouraging and reversing the actuation of shutoff valves, pumping means, etc.
As a whole, the productivity of the extrusion press is lost.

The technical problem underlying the present invention is to carry out an air ejection cycle during the extrusion of billets, as well as a method of extrusion having functional and structural features to overcome the drawbacks present in the prior art. And to provide an extrusion press.

[0011]

In order to solve such a problem, the method of the present invention uses a thrust force of a carrier against an extrusion die so that air is ejected from between a billet and the die. In addition, it includes a step of temporarily controlling the thrust force of the plunger against the billet during the extrusion process.

The present invention also provides temporary control of the thrust force produced by the extrusion of at least one source of pressurized oil, ie, billet, connected to an auxiliary hydraulic cylinder / piston assembly for the carrier and plunger. And a press characterized in that it comprises a source of pressurized oil effective to provide a predetermined pressure to both the carrier and the plunger by means of a suitable auxiliary hydraulic cylinder / piston assembly.

[0013]

EXAMPLE An extrusion method and an extrusion press according to an example of the present invention will be described below with reference to FIG.

As shown in FIG. 1, an extrusion press 1 according to this embodiment comprises a plunger 2 having a main hydraulic cylinder / piston assembly 3 and two auxiliary hydraulic cylinder / piston assemblies 4. The auxiliary hydraulic cylinder / piston assembly 4 each comprises a double-acting piston 4a movable in the cylinder 4b, which double-acting piston 4a defines a filling chamber 4c and an annular chamber 4d.

The filling chamber 4 means the volume enclosed between the wall of the cylinder 4b and the wall of the double-acting piston 4a, which is filled with oil. The annular chamber 4d includes the cylinder 4
It means the volume enclosed between the wall of b and the wall of the piston 4a partly occupied by the piston rod (not shown).

The extrusion press 1 also comprises a carrier 5 for the steel slab (b). The carrier 5 is connected to a pair of auxiliary hydraulic cylinder / piston assemblies 6, respectively. These auxiliary hydraulic cylinder / piston assemblies 6
Includes a double-acting piston 6a movable in the cylinder 6b. The double-acting piston 6a includes a filling chamber 6c.
And an annular chamber 6d.

Fill chamber 6c and annular chamber 6d
Is configured similarly to the chamber of the hydraulic cylinder / piston assembly 4 described above.

The plunger 2 can reciprocate with respect to the carrier 5 so that it can come into contact with and separate from the carrier 5, and in turn can reciprocate with respect to the extrusion die M so as to come into contact with and separate from it. The plunger 2 and the carrier 5 move along a direction coinciding with the extrusion axis of the extrusion press 1.

The extrusion press 1 comprises a hydraulic cylinder /
It comprises a hydraulic system 7 which circulates oil through a piston assembly.

The first branch 8 of the hydraulic system 7 connects the filling chambers 4c of the main hydraulic cylinder / piston assembly 3 and the auxiliary hydraulic cylinder / piston assembly 4 and a set of main supply and discharge pumps 9,10. ..

The second branch 8a of the hydraulic system 7 connects the first hydropneumatic pressure accumulator 11 and the annular chamber 4d of the auxiliary hydraulic cylinder / piston assembly 4 for the plunger 2. The first hydropneumatic pressure accumulator 11 comprises a pilot solenoid valve 12 for a cartridge valve 13.

The third branch 14 of the hydraulic system 7 comprises an auxiliary hydraulic cylinder / piston assembly 6 for the carrier 5.
From the filling chamber 6c to the main supply and discharge pumps 9 and 10. The fourth branch 14a connects the second hydraulic / pneumatic pressure accumulator 15 to the annular chamber 6d of the auxiliary hydraulic cylinder / piston assembly 6. The second hydropneumatic pressure accumulator 15 comprises a pilot solenoid valve 16 for a cartridge valve 17.

A prefill valve 19 having a pressure regulating valve 20 is arranged at the oil inlet 18 of the main hydraulic cylinder / piston assembly 3 for the plunger 2. The main supply / exhaust pumps 9 and 10 are respectively the bypass blocks 2 described later.
1, 22 are provided.

A third hydropneumatic accumulator 23 with a hold-up solenoid valve 24 is connected to the filling chamber 6c of the auxiliary hydraulic cylinder / piston assembly 6 which drives the carrier 5.

The delivery side 25a of the additional pump is connected to the first to third hydropneumatic pressure accumulators 11, 15, 23. The pair of check valves 26, 27, 28 are provided on the distribution side 25a.
The first to third hydropneumatic pressure accumulators 11, 15, 23
In addition, it has a function of connecting independently from the other two pressure accumulators.

A pressure converter 29 is incorporated in the prefill valve 19.

The operation of the extrusion press of this embodiment will be described below.

The state during extrusion of the steel slab b placed on the carrier 5 is assumed as the initial reference state of the extrusion press 1.

In this state, when the steel slab b of the carrier 5 is compressed by the plunger 2 which moves in the carrier direction and presses the steel slab b, the carrier 5 moves and is juxtaposed with the extrusion die M. Press the extrusion die in position.

Under initial conditions, the solenoid valve 24 is energized and the main hydraulic cylinder / piston assembly 3 and the fill chambers 4c, 6c supply pressurized oil from pumps 9, 10, respectively.

Starting from this initial state, the pressure regulating valve 20 is released and the pressure in the filling chamber 4c and the main hydraulic cylinder / piston assembly 3 is reduced. At this time, the power of the holdup solenoid valve 24 is turned off. The pressure transducer 29 is the main hydraulic cylinder / piston assembly 3
When the pressure drop of the oil supplied to is detected, and when a predetermined pressure level is reached, the solenoid valves 12 and 16 are excited and the corresponding valves 13 and 17 are activated.

At this time, the main supply and discharge pumps 9 and 10 are
They are respectively detoured by the corresponding bypass blocks 21 and 22, and the distribution of oil to the two branches 8 and 14 of the hydraulic system 7 is suppressed. During the extrusion process,
Such a constant operating state is maintained.

First and second hydropneumatic pressure accumulators 11, 1
5 is arranged, at this time, the plunger 2 and the carrier 5
Valve 1 in communication with the annular chambers 4d, 6d of the auxiliary hydraulic cylinder / piston assemblies 4 and 6 of
3, 17 are released.

First and second hydropneumatic pressure accumulators 11, 1
In 5, the oil maintains a certain pressure and flows into the annular chambers 4d, 6d via the released valves 13, 17.

First and second hydropneumatic pressure accumulators 11, 1
Due to the oil contained in 5, double-acting pistons 4a, 6a
The pressure exerted on is due to the force generated in the double-acting pistons 4a, 6a by the pressure exerted by the oil present in the filling chambers 4c, 6c via the previous extrusion process initially performed by the extrusion press 1. It is suitable to make up for.

Such a compensating force maintains the carrier 5 and the plunger 2 in a balanced state. The carrier 5 and the plunger 2 move in the direction of the extrusion die M and come into contact with each other, and the carrier is stopped. In fact, by appropriate time adjustment of the excitation of the solenoid valves 12, 16, the plunger 2 and the carrier 5
The pressures acting in the auxiliary hydraulic cylinder / piston assemblies 4 and 6 can be maintained in balance without inducing back movement in the carrier 5 and the plunger 2.

When the pressure regulating valve 20 is released, the filling chamber 4c and the main hydraulic cylinder / piston assembly 3
The internal pressure immediately decreases due to the action of the oil pressurized from the first hydropneumatic pressure accumulator 11.

This pressure reduction is performed by continuously reducing the valve within a cycle set by the user. In fact
The degree of the cycle and the amount of pressure decrease correspond not only to the holding pressure of the oil in the first hydropneumatic pressure accumulator 11, but also to the ratio of the filling chamber 4c and the main hydraulic cylinder / piston assembly 3. When the pressure in the first hydropneumatic pressure accumulator 11 is high, oil flows from the first hydropneumatic pressure accumulator 11 into the annular chamber 4d.

The pressure of the air trapped between the steel slab b and the extrusion die M causes the carrier 5 to stop pressing against the die, and when the plunger no longer presses the steel slab in the carrier, it leaves the gap. Can be extruded.

At the same time when such air is ejected, the solenoid valve 2
By turning off the power of No. 4, the additional pump 25
The hydraulic / pneumatic pressure accumulator 23 is replenished.

After venting the air, the solenoid valve 12
And 16 are turned off. The pressure regulating valve 20 is closed and the pumps 9 and 10 are once again in the first position of the hydraulic system 7.
And the third branch 8, 14. Then, the hold-up solenoid valve 24 is activated and the third hydropneumatic pressure accumulator 23 is connected to the filling chamber 6c of the auxiliary hydraulic cylinder / piston assembly 6 for the carrier 5.

As a result, the extrusion press 1, together with the carrier 5 and the plunger 2, is at a position that does not change from the initial state,
That is, at the position located during the extrusion process prior to the air vent cycle, the billet b is ready for resumption of extrusion.

When the extrusion process of the billet is restarted, the valves 24 and 2 are
The additional pump 25 is returned with the assistance of 6, 27, 28, and the first to third hydropneumatic pressure accumulators 11, 15, 2
The pressure inside 3 returns to their set width in preparation for successive cycles of air ejection from the extrusion press 1.

The extrusion press 1 according to this embodiment has a number of advantages.

The first to third hydropneumatic pressure accumulators 11,
The oils pressurized in 15, 23 are respectively in the annular chamber 4
In the d, 6d and the filling chamber 6c, the pressure becomes a predetermined high level and is immediately available without being excessive. By using a hydropneumatic pressure accumulator instead of the pump, optimum control of the operation process of the extrusion press 1 and the driving of the plunger and the carrier becomes possible.

As described above, such control is efficiently performed by adjusting the timing, and the annular chambers 4d and 6d and the filling chambers 4c and 6c in the auxiliary hydraulic cylinder / piston assemblies 4 and 6 for the plunger 2 and the carrier 5 are efficiently controlled. The balance of pressure acting on the
It can be kept constant.

The hydropneumatic pressure accumulator is composed of pumps 9, 1
There is no activation of transient conditions such as 0,25 and the duration of the air ejection cycle is even shorter. Therefore, the productivity of the extrusion press is improved.

Further, since the hydropneumatic pressure accumulator and the bypass block are provided, after the completion of the air ejection cycle,
When the extrusion process is restarted, the main feed evacuator pump does not require various adjustments and associated operating time,
Already, the optimum stable operating state can be achieved.

Finally, in order to carry out the air ejection cycle, the prefill valve 19 does not have to be opened, only the pressure regulating valve 20 is activated. Therefore, the additional time required to complete the entire ejection cycle can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of an extrusion press according to an embodiment of the present invention.

[Explanation of symbols]

M ... Extrusion die, b ... Steel piece, 2 ... Plunger, 3 ... Hydraulic cylinder / piston assembly, 4 ... Hydraulic cylinder / piston assembly, 5 ... Carrier, 6 ... Auxiliary hydraulic cylinder / piston assembly, 11 ... First hydraulic air pressure Accumulator, 15 ... A second hydropneumatic accumulator.

Claims (7)

[Claims] 1. A method for performing a jetting cycle of air accumulated between a die (M) and a billet (b) in a billet extrusion press, said extrusion press comprising: ), A carrier (5) reciprocating along the longitudinal extrusion axis of the extrusion press so as to come into contact with and separate from the die (M), and a carrier (5) contacting the carrier (5) along the longitudinal extrusion axis. And a plunger (2) capable of reciprocating so as to be separated from each other, and the carrier (5) is
With an auxiliary hydraulic cylinder / piston assembly (6),
And the plunger (2) has a main hydraulic cylinder / piston assembly (3) and associated auxiliary hydraulic cylinder / piston assembly (4), said extrusion press also comprising pump means (9,10). A method comprising a hydraulic oil transfer system (7) extending between a hydraulic cylinder / piston assembly (6, 3, 4), comprising: collecting air accumulated between a billet (b) and a die (M). Carrier (5) to the extrusion die (M), so as to eject
The thrust force of the plunger (5) against the billet (b) during the extrusion process, as well as the thrust forces of the method. 2. An extrusion press for executing a jetting cycle of air accumulated between a die (M) and a steel billet (b) in a billet extrusion press, wherein the extrusion press is a steel billet ( a carrier (5) supporting b) and capable of reciprocating so as to come into contact with and separate from the die (M) along the longitudinal extrusion axis of the extrusion press; and a carrier (5) along the longitudinal extrusion axis. A plunger (2) reciprocally movable to and from the carrier (5), the carrier (5) having an auxiliary hydraulic cylinder / piston assembly (6), and the plunger (2) It has a main hydraulic cylinder / piston assembly (3) and an associated auxiliary hydraulic cylinder / piston assembly (4), said extrusion press also comprising pump means (9,10) and hydraulic cylinder / piston assembly (6,6). Three 4) In an extrusion press equipped with a hydraulic oil transfer system (7) extending between it and an auxiliary hydraulic cylinder / piston assembly (6, 4) for carrier (5) and plunger (2) A pressurized oil source (11, 15), i.e. an auxiliary hydraulic cylinder / piston assembly (6, 4) suitable for temporarily limiting the thrust force generated by the extrusion of the billet (b), by means of the carrier and An extrusion press comprising a pressurized oil source (11, 15) capable of supplying a predetermined pressure to both plungers. 3. An auxiliary hydraulic cylinder / piston assembly for a plunger (2) and a carrier (5), wherein the source of pressurized oil extends over the second and fourth branches (8a, 14a) of the hydraulic system (7). Extrusion press according to claim 2, characterized in that it comprises first and second hydropneumatic pressure accumulators (11, 15) connected to (4, 6). 4. A pumping means (9, 10) extending from the main hydraulic cylinder / piston assembly (3) to the filling chamber (4c) of the auxiliary hydraulic cylinder / piston assembly (4) for the plunger (2), respectively. A first branch (8) forming an outcoming hydraulic circuit and a hydraulic system extending from a pump means (9, 10) into a filling chamber (16) of an auxiliary hydraulic cylinder / piston assembly (6) for a carrier (5) Associated with the third branch (14) of (7), the first valve device (12, 13) associated with the first hydropneumatic pressure accumulator (11), and the second hydropneumatic pressure accumulator (15). A second valve device (16, 17), an additional pump (25) for supplying oil to the first and second hydropneumatic pressure accumulators (11, 15), and a plunger (2) for supplying the oil, And the first and second Extrusion press according to claim 3, characterized in that it comprises a device (12, 13, 16, 17) is connected to a pressure transducer (29), the. 5. Pumping means (9, 10) each have a first
The extrusion press according to claim 4, further comprising a bypass block (21, 22) distributed in the third branch (8, 14). 6. The extrusion press comprises a hold-up solenoid valve (2) connected to a filling chamber (6c) of an auxiliary hydraulic cylinder / piston assembly (6) for a carrier (5).
Extrusion press according to claim 5, characterized in that it comprises a third hydropneumatic pressure accumulator (23) with 4). 7. A first and a second valve device (12, 13, 1).
6, 17) are pilot solenoid valves (12, 16), respectively.
7. An extrusion press according to claim 6, characterized in that it comprises a cartridge solenoid valve (13, 17).