JPS6255926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extrusion press apparatus having a function of matching machine alignments of dies, containers, stems, etc. to optimal conditions in order to prevent uneven thickness of pipes.

It is said that the uneven thickness of a tube material extruded by an extrusion press cannot be improved by using a reducer or drawing in the subsequent process, and there is a strong demand for improving the accuracy of the uneven thickness in an extrusion press.

Conventionally, the alignment of machines such as dies, containers, stems, etc. has only been adjusted in a static state, but the alignment in a dynamic state, that is, during extrusion, has actually been measured.
Furthermore, it was not possible to adjust the optimum machine alignment under dynamic conditions. However, as will be understood from the reasons described below, the core tends to become distorted during extrusion or over time, so there is a strong demand for a method for adjusting centering in a dynamic state.

Hydraulic pressure applied to the main cylinder 2 fixed to the base 1 is applied to the counter platen 10 via the main crosshead 3, the stem 4, the dummy block 5, the billet 6, the die 7, the bolster plate 8, and the pressure plate 9. and is canceled out by the reaction force by the column 11. Therefore, an elongation of λ occurs in the column 11. In this case column 1
The hydraulic pressure transmitted to 1 varies greatly according to the extrusion process, that is, upsetting → pressure relief → piercing → pressure relief → completion of extrusion. For this reason, the elongation of the column 11 also changes in response to changes in hydraulic pressure. Therefore, when the counter platen 10 slides due to the expansion and contraction of the column 11, the container 12 needs to follow the movement of the counter platen 10. The container holder 13 is supported by X and is attracted by a container shift cylinder 14 assembled to the counter platen 10.

However _, since there is a frictional force on the sliding _surface 12 and die 7 and container 12 and stem 4,
The core L of the die 7 and the mandrel 15 are misaligned, and as a result, the die 7 and the mandrel 15 are misaligned. Other factors that may cause the alignment L of the container 12 and the dice 7 to be out of alignment include the difference in the attractive force of the container shift cylinders 14 (i.e., the difference in the sliding resistance of the cylinders), which causes the dice 7,
Bolster plate 8, pressure plate 9
(The amount of compressive deformation during extrusion cannot be translated in parallel) etc., which occur along with the expansion and contraction of the column 11, further increasing the deviation of the thread center L.

In this way, when the container 12 tilts, the container 12
This causes the stem 4, mandrel 15, and die 7 to be misaligned, causing an uneven load on the stem 4 and mandrel 15. Furthermore, the behavior of the dummy block 5 during upsetting also causes an uneven load on the stem 4 and mandrel 15.

The unbalanced load generated on the stem 4 and mandrel 15 is
When the billet 6 undergoes plastic deformation during extrusion, the deformation resistance becomes non-uniform, and this non-uniform deformation resistance is also one of the causes of the uneven wall thickness of the tube. Furthermore, the unbalanced loads on the stem 4 and mandrel 15 also apply unbalanced loads to the main crosshead 3 that supports the stem 4 and mandrel 15. As a result, the sliding surface of the main crosshead 3 wears unevenly, the alignment between the stem 4 and the container 12 becomes misaligned over time, and uneven wall thickness tubes are more likely to occur.

In view of the above circumstances, the present invention was made with the aim of always maintaining the machine alignment of the extrusion press die 7, container 12, stem 4, etc. in an optimal state and preventing the occurrence of uneven wall thickness tubes. A die position detection device detects the position of the die through the movement of a probe brought into contact with the die, and the tilt of the container is detected through the load condition acting on a lever brought into contact with the container. A displacement detection lever, a load detector provided on at least one of the stem or the mandrel holder, and a posture control cylinder provided on each sliding surface of the container holder supporting the container, the stem, and the main crosshead supporting the mandrel holder. The machine is characterized in that the machine axis can be corrected by driving the both posture control cylinders based on the detection results from the die position detection device, the displacement detection lever, and the load detector. be.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 9.

The die 7 and the bolster plate 8 are provided so that they can be dropped into the receiving portion of the die slide 16 from above, and the die slide 16 is passed through the counter platen 10 by a slide guide 17 and a saw die 19 so as to be perpendicular and horizontal to the core L. It is attached so as to be slidable in the direction, and passes through the die 7 and the bolster plate 8 so that it can be attached and detached at a position away from the core L.

Container holder 13 into which container 12 is fitted
The main crosshead 3 supporting the stem 4 and mandrel 15 has legs 20,
21 are provided, each leg 20,2
A required number of cylinders 22 and 23 for attitude control are provided at the lower end of the base 1, and the container holder 13 and the main crosshead 3 are slidably mounted on the centripetal guide 24 of the base 1 via the cylinders 22 and 23.

A pressure plate 25 is fitted to the end of the main crosshead 3 on the side of the container 12, and the base of the stem 4 is brought into contact with the pressure plate 25, and a tightening fitting is attached via a holding fitting 26. 27 fixes the stem 4 to the main crosshead 3.
Further, a piercer crosshead 29 is provided in the hollow portion 28 of the main crosshead 3 so as to be slidable in the direction of the thread line L, and is moved by a mandrel cylinder 30 connected to the piercer crosshead 29. There is. A mandrel holder 31 through which the stem 4 is inserted is fixed to a piercer crosshead 29, and a mandrel 15 is provided at the tip of the mandrel holder 31. The main crosshead 3 is connected to the main cylinder, and the mandrel cylinder 30 cooperates with the main cylinder to extrude the pipe.

The die slide 16 is provided with a die position detection device 32, and the tips of the saw die 19 and slide guide 17 are brought into contact with predetermined locations on the die side end face of the container 12 as shown in FIG. A displacement detection lever 33 is installed so that a change in load corresponding to the change in load occurs, so that a change in the position of the dice 7 and an inclination of the container 12 can be detected. In addition, strain gauges 34 and 35 are attached to required locations on the outer peripheral surface of the base of the stem 4 and the mandrel holder 31, respectively.
Detecting the load and load state acting on the stem 4 and the mandrel 15 through the elastic strain generated in the portion,
The misalignment of the stem 4, mandrel 15, and container 12 can be detected through the detection results.

The position detection device 32 has a plunger 37 fitted into a guide hole 39 formed in a die holder 36 fixed to the die slide 16 so as to be slidable in a vertical direction passing through the center of the die 7, and inserted into the guide hole 39. The spring 38 is provided in a compressed state, and the plunger 3
7 is always urged toward the center of the die 7, the tip of the plunger 37 is brought into contact with the die 7, a stopper 41 is screwed to the rear end, and an appropriate device such as Magnescale, differential pressure, etc. It is formed by combining a displacement meter 42.

Further, as shown in FIG. 8, the displacement detection lever 33 is provided with a contact terminal 43 made of a bolt or the like and whose protrusion amount can be adjusted, and the tip is connected to the container 12 via the contact terminal 43. A strain gauge 44 is attached to the required position of the displacement detection lever 33 so that the amount of displacement of the contact terminal 43 can be detected through the amount of strain detected by the strain gauge 44.

Therefore, the die position detection device 32, the displacement detection lever 33, and the strain gauge 34 attached to the stem 4,
Strain gauge 35 attached to mandrel holder 31
Accordingly, it is possible to detect whether or not the respective threads of the die 7, container 12, stem 4, and mandrel 15 are out of alignment with the proper thread L.

Next, in FIG. 7, the attitude control cylinders 22 and 23 are driven based on the values detected by the various detection devices described above, and the container 12 and the main crosshead 3 are corrected to match the proper center line L. A control device 50 is shown.

Dice position detection device 32, displacement detection lever 33,
The comparators 45, 46, 47 attached to the stem 4 or the mandrel holder 31 and connected to either one of the strain gauges 34, 35 are connected in advance to each comparator 4.
Appropriate center line L set at 5, 46, 47
The amount of misalignment or correction amount of each of the dice 7, container 12, and stem 4 (or mandrel 15) is calculated, and the calculation results are input to the controller 48.

The controller 48 inputs the calculation results of the respective comparators 45, 46, and 47 into a preset attitude control program, and performs the respective attitude control in order to obtain the optimum attitude of the container 12 and the attitude of the main crosshead 3. The stroke settings of the control cylinders 22 and 23 are calculated, and the respective servo valves 51 and 52 are actuated based on the calculation results.
2 and 23.

As a method of attitude control, first, the attitude control cylinder 23 of the main crosshead 3 is driven so as to correct the misalignment between the die 7 and the mandrel 15, and the stem 4 or the mandrel holder 31 is driven.
The attitude control cylinder 22 of the container holder 13 is driven to correct the inclination so that the unbalanced load acting on the container holder 13 is reduced, but the amount by which these attitude control cylinders 22 and 23 are driven is constant during the extrusion process. The current posture is detected and outputted from the controller 48 for each extrusion stroke. In this way, dice 7, container 12, stem 4,
The core of the mandrel 15 can be matched with the die 7 as a reference. Moreover, the strain gauge 3
4 and 35 can detect an abnormal load acting on the stem 4 and mandrel 15, and if an abnormal load acts, it is possible to take safety measures such as stopping the extrusion operation.

It should be noted that various means for detecting the deviation of the core, such as the die position detecting device 32 described above, can be considered, and a plurality of die position detecting devices 32 may be provided, and the plunger 37 may be replaced with a probe such as a rotatable lever. may be provided to detect the rotational displacement of the lever.
Regarding the displacement detection lever 33, as shown in FIG. 9, a lever 33' is rotatably mounted at the base end, and a load cell 49 is provided at the base, and the rotational displacement of the lever 33' is used as the load displacement generated on the load cell 49. It may also be made detectable. Furthermore, instead of the strain gauge 34 attached to the stem 4, a load cell may be used, and in this case, the load cell may be embedded at positions equally divided into the circumference of the pressure plate 25.

As described above, according to the present invention, (i) it is possible to detect the misalignment of the machine alignment of an extrusion press device, which was impossible in the past; (ii) it is possible to detect the misalignment of the machine alignment of an extrusion press device, which was impossible in the past; It exhibits excellent effects such as being able to maintain the core in an optimal condition and preventing the core from becoming misaligned over time; and (iii) therefore preventing uneven thickness of the pipe and manufacturing highly accurate pipes. obtain.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional extrusion press device;
The figure is an explanatory diagram of the container and die portion of the same device, FIG. 3 is a partial explanatory diagram of an extrusion press device equipped with a machine alignment control device according to the present invention, and FIG. 4 is a view taken in the direction of arrow A in FIG. 3. 5 is a view in the direction of arrow B in FIG. 3, FIG. 6 is a view in the direction of arrow C in FIG. 3, and FIG. 7 is an explanatory diagram of the control device.
8A and 8B are explanatory diagrams of the displacement detection lever, and FIG. 9 is an explanatory diagram showing another example of the displacement detection lever. 3 is the main crosshead, 4 is the stem, 7 is the die, 15 is the mandrel, 16 is the die slide,
22, 23 are cylinders for attitude control, 32 is a die position detection device, 33 is a displacement detection lever, 34, 35
indicates strain gauge.

Claims (1)

[Claims] 1. A die position detection device that detects the position of the die through the movement of a probe brought into contact with the die;
a displacement detection lever that detects the inclination of the container through a load state acting on a lever that is brought into contact with the container; a load detector provided on at least one of the stem or the mandrel holder; a container holder and the stem that support the container; and a posture control cylinder provided on each sliding surface of the main crosshead that supports the mandrel holder, and the two posture control cylinders are configured based on the detection results from the die position detection device, the displacement detection lever, and the load detector. An extrusion press device characterized in that the machine alignment can be corrected by driving the.