JPH0857567A - Ring rolling mill with damping device - Google Patents

Abstract

PURPOSE: To work a ring in a cold roll where an overload of a rolling tool due to a variation of a thickness caused by an eccentricity of a hole of a ring- shaped half-finished workpiece is avoided by enabling a slider supporting a mandrel roll to advance according to a predetermined characteristic curve by a speed controller when the cold roll of a ring is carried out by using a ring-shaped half-finished workpiece having a large variation in thickness. CONSTITUTION: A damper type fastening and fixing device 10 of a type operated by a pressure medium is provided between each upright supporting column 9 and a bracket 7. This fastening and fixing device 10 has a single-acting type working piston 12 connected with a piston rod 13 which is axially movable in a cylinder 11. This working piston 12 is connected to the bracket 7 by the cylinder 11 and to the upright supporting column 9 by the piston rod 13, respectively. A working chamber 30 in front of the working piston 12 is filled with an incompressible pressure medium and a pressure medium connection port 33 leading to a medium pressure source 34 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mandrel roll supported by a payable slider and a driving roll for rolling the outer peripheral surface of a ring (work), which are vertically arranged in the form of a structural group. , Ring rolling machine with damping device for cold rolling rings in which the shaped roll is rotatably supported on a horizontal, stationary bracket supported by vertical uprights.

[0002]

2. Description of the Related Art A method in which a ring is cold-rolled between a shape roll and a mandrel roll shaped according to the inner peripheral surface of a work is particularly economical and can increase the material utilization rate. The rolling tool made with high precision transfers its profile shape to the ring-shaped semi-finished product which is automatically fed to the ring rolling mill. The ring-shaped semi-finished product is received by the mandrel rolls supported on both sides by the slider in the working space of the ring rolling mill, and by the deforming force generated hydraulically, it is supported by the vertical upright columns and driven to rotate in the horizontal bracket. The shaped roll is pressed by reducing the roll gap in the radial direction. In that case the wall thickness of the ring is reduced and the diameter is increased considerably since the ring width is practically constant. After the desired final diameter is reached, the deformation process is terminated and the roll return is initiated after a corresponding end of the calibration time.

Since the roll gap is generally continuously adjusted during cold rolling of the ring, the shape and movement of the roll gap are not stable. For this reason, the thickness and height of the ring entering the roll gap at that moment are also not constant and depend on the respective roll gap and the geometry of the tool. Since the behavior of the material cannot be accurately detected during the rolling process and the deformation resistance of the ring material changes, the tool cannot be well controlled and paid out, so there is an urgent risk of impeding production. . For that reason, when cold rolling the ring, a large safty zone is required to prevent overloading of the very elongated mandrel rolls. Further, during the cold rolling process in which a large rolling force causes combustion on the surfaces in contact with each other, the rolling force must be accurately controlled by feeding the slider. For the above-mentioned reasons, in the past, when cold rolling a ring, a ring-shaped semi-finished product that has been previously lathe-processed or polished is used, and its wall thickness is within a very narrow tolerance range.

The dimensions of the starting shape of the ring must be determined so that the entire profile of the ring is rolled with a minimum of deformation work, given the constant volume. Accurate determination of the starting shape of the ring is essential because the flow of material during deformation and thus the growth of the ring is uncontrollable. When the holes of the ring-shaped semi-finished product are eccentric, the thickness of the holes is different in the circumferential direction, so that the positions of the holes must be closely watched. This different wall thickness causes a very rapid overload of the rolling tool. On the other hand, a very large noise load occurs due to the deformation noise increased by the different wall thicknesses. For this reason, the selection and utilization of starting materials for ring-shaped semi-finished products is within narrow limits. This goes against increasing the economics of the method of manufacturing the ring by cold rolling.

German Patent DE 907765 discloses a ring rolling mill in which a hydraulically generated rolling pressure is applied to an inner roll supported by a slider. The inner roll can move radially towards the stationary outer roll with a reduced roll gap. The ring-shaped workpiece is rolled between the outer and inner rolls until it becomes thin and thus a ring of large diameter results. The rolling pressure is applied to the work by the inner roll. The inner roll is therefore the pressure roll and is arranged on the slider for this purpose. This slider is guided in a fixed frame of the rolling mill so that it can be moved towards and away from the outer roll. The slider is driven by a hydraulic piston that produces rolling pressure.

In order to eliminate the defects caused when the hole of the work is eccentric, pressure transmitting means for constantly pressing the pressing roll against the work is provided. This pressure transmitting means comprises a rod which contacts and supports the housing of the outer bearing of the inner roll. This rod is supported in contact with the block via a lever supported by a bolt. The block itself is connected to the hydraulic piston by a push rod and an upper beam. A buffer spring is connected in advance to the block. The buffer spring constantly presses the inner roll against the work, even if the work has a non-uniform wall thickness.

The buffer spring acting against the hydraulic piston reduces the deformation force not only when the hole of the workpiece is eccentric, but also when the ring material has a high deformation resistance.
This is especially undesirable if the slider is moved out in a speed control device or according to a predetermined characteristic curve. In the above-mentioned case, a ring rolling machine formed as a rigid system is required, which, on the other hand, requires a ring-shaped workpiece which is previously ground or turned and has a small wall thickness variation. Therefore, the above-mentioned buffer spring method serves exclusively for guiding and rolling thin-walled rings over a long period of time.

[0008]

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to make use of ring-shaped semi-finished products which are made to a large tolerance and in some cases have a large variation in wall thickness. The purpose is to improve the economical efficiency when cold rolling a ring.

Therefore, an object of the present invention is to provide a rolling tool for a rolling tool due to a variation in wall thickness caused by a slider supporting a mandrel roll being drawn out by a speed control device in accordance with a predetermined characteristic curve and the holes of a ring-shaped semi-finished product being eccentric. The purpose is to make a ring rolling machine for cold rolling a ring that avoids overload.

[0010]

SUMMARY OF THE INVENTION According to the invention, the object of the invention is to provide a pressure-medium-actuated damper-type clamping device between the respective uprights and the bracket, which clamping device is arranged in the housing. It has a single-acting working piston with a piston rod that can move in the axial direction.The working piston is connected to the bracket by the cylinder and the upright column by the piston rod, and the working chamber in front of the working piston is incompressible. This is achieved by providing a pressure medium connection port which is filled with a pressure medium and communicates with a hydraulic pressure source.

According to the damper type tightening and fixing device of the ring rolling mill according to the present invention, even when the thickness of the ring-shaped semi-finished product is changed, the impact generated during rolling is absorbed, so that the rolling Impact loads are avoided in this case, which makes operation of the ring mill quiet. Semi-finished products with even worse dimensional accuracy can be utilized, which further increases the economics of producing rings by cold rolling.

In another embodiment of the present invention, the ring rolling mill is arranged such that the pressure medium contained in the working chamber of the cylinder is brought to a high pressure state to clamp and fix the bracket to the upright column, and the working piston is at least subjected to rolling force. Characterized by being urged with the same or greater clamping force. For this reason, for example, the ring rolling mill can be made as a rigid system whenever exclusively linear payout of the slider is useful.

Further within the framework of the invention, in order to limit the clamping force in addition to the hydraulic pressure source acting on the working piston, a pressure medium as a pressure control device is provided in the pressure medium pipe between the hydraulic pressure source and the working chamber. A variable adjusting element for controlling the passage is provided, which variable element is controlled when the deformation resistance of the ring to be rolled exceeds the rolling force and is reset when the deformation resistance becomes smaller than the rolling force. To propose. This allows the rolling force and roll gap to be adapted to changing rolling processes.

Furthermore, it is advantageous if the pressure control device is a direct control type pressure limiting valve or, if a computer assists the clamping force control, an electronically controlled proportional pressure limiting valve. This makes it possible to force-roll up the roll gap when the deformation resistance in the roll gap increases significantly when rolling a ring using a ring-shaped semi-finished product with eccentric holes. .

Nevertheless, the great advantage of the present invention is that
In most cases still when rolling the ring, the slider can be moved according to a predetermined characteristic curve by means of a speed control device, maintaining exactly the predetermined conditions required by the deformation technology with regard to deformation speed and cross-section reduction. There is something that can be done. First of all, rings with greatly different wall thicknesses can be rolled without problems. Splitting has the important advantage of significantly reducing the risk of mandrel roll breakage. The long service life of the rolling mill greatly reduces the downtime required for tool changes and significantly increases the economics of the cold rolling process.

[0016]

The present invention will be described in detail with reference to the embodiments shown in the drawings.

In FIG. 1, the first structural group of the ring product rolling mill comprises a machine body 1 having a payout slider 2 on which a mandrel roll 4 is rotatably supported. Ring 3 to be manufactured from ring-shaped semi-finished product 3 '
The mandrel rolls 4 present inside the ring act radially on the ring 3 and transfer its outer profile to the ring 3 to be manufactured during cold rolling. According to the inner diameter of the ring-shaped semi-finished product 3 ′ to be rolled, the mandrel roll 4 is line-contacted and supported by the supporting roller 6 arranged laterally for strength reasons. The diameter is chosen to be more or less large.

On the mandrel roll 4, a shaped roll 8 is rotatably supported by a horizontal bracket 7 in the form of a second structure group. This shape roll 8 has the shape of the outer peripheral surface of the ring 3 to be manufactured from the ring-shaped semi-finished product 3'in a negative shape. Both rolls, the mandrel roll 4 and the shaping roll 8, are rotary drives (not shown)
The mandrel roll 4 is driven to rotate by the slider 2 in order to reduce the roll gap (roll opening).
Can be extended in the radial direction.

The horizontal brackets 7 are supported by upright stanchions 9 arranged in pairs with the rotationally driven profiled rolls 8 of the second group of structures. These columns 9 mainly strengthen the strength of the machine frame of the ring rolling machine formed of the bracket 7 and the machine body 1 against the rolling force required in the rolling process and the deformation force generated in the cold rolling. Enough to receive. A pressure-medium-actuated damper-like clamping device 10 is provided above the brackets 7 for clamping the horizontal brackets 7 on the respective columns 9 or on the machine body 1.

As shown in FIG. 2, the pressure medium actuated damper-like clamping and fixing device 10 has a piston rod 13
It has an upright cylinder 11 with a working piston 12 attached thereto. The piston rod 13 is connected to the upper end of the column 9 via a shaft rod 14. The cylinder 11 is rigidly connected to the horizontal bracket 7 by a bolt 16 via a mounting plate 15. The piston rod 13 and the column 9 are rigidly connected to each other by the shaft rod 14 described above. For this purpose, this shaft 14 has a threaded shank 18 with a screw 17. The threaded shaft portion 18 is just screwed into an axial threaded hole 19 provided corresponding to the piston rod 13. After the threaded shaft 18 is screwed into the piston rod 13 and connected, a radial pin 20 is provided as a screw lock.

There is a screw hole 21 at the lower end of the shaft rod 14, and a threaded shaft portion 22 provided on the support column 9 is screwed into the screw hole 21, whereby the support column 9 is screwed to the shaft rod 14, and the bracket 7 A tight bond is made with.

Further, a guide shaft 23 extending in the axial direction is provided at the lower end of the shaft rod 14. The guide shaft 23 is guided in a hole 24 of a guide bush 25 so as to be movable in the axial direction. The guide bush 25 is concentrically screwed to the bracket 7 by a mounting bolt 27 with respect to a column guide 26 existing on the bracket 7. An adjusting screw portion 28 with an adjusting nut 29 is provided axially following the area of the guide shaft 23 of the shaft rod 14.

The shaft 14 is used to tightly connect the working piston 12 to the piston rod 13, or the column 9 and the shaft 14.
After the hard connection with the bracket 7 is performed, by adjusting the adjustment nut 29 with the bracket 7 placed on the column 9,
The working piston 12 is positioned horizontally with respect to the cylinder 11, and the cylinder 11 has a working chamber 30 on the front surface of the working piston 12 and an exhaust hole 32 on the back surface of the working piston 11.
And an exhaust chamber 31 with

Further, the cylinder 11 is provided with a pressure medium connection port 33 opening to the working chamber 30 on the front surface of the working piston 12. The pressure medium connection port 33 is connected to a pressure medium pipe 35 that communicates with a hydraulic pressure source 34. In parallel with the hydraulic pressure source 34, a pressure regulating device 36 in the form of a variable regulating element for controlling the pressure medium passage is provided. As a result, the hydraulic pressure generated by the hydraulic pressure source 34 can be adjusted. In a special embodiment of the invention, the hydraulic pressure source 34, which consists of a high-pressure pump, supplies pressure oil which is arranged to generate the rolling pressure and to pay out the slider 2.

The operation of the ring rolling mill according to the present invention is such that the working chamber 30 in front of the working piston 12 has the hydraulic pressure source 34.
The hydraulic pressure generated by the high pressure causes the tightening force to be generated. In the state where the tightening force is guided to the support column 9 via the piston rod 13 and the cylinder 11 is in contact with and supported by the bracket 7, the bracket 7 and the machine body 1 are firmly tightened and fixed. The clamping force produced by the hydraulic pressure source 34 is determined so that it is greater than the rolling forces produced simultaneously, thus making the ring mill a rigid profile subject to any deformation forces. In the normal case this results in the shape shown in FIG. 3 and a relatively uniform wall thickness D.
Any ring known per se can be molded. The wall thickness D thereof decreases by a value twice as large as ΔD and linearly corresponding to the payout of the slider 2 each time the ring 3 rotates between the shaping roll 8 and the mandrel roll 4. When the holes of the ring-shaped semi-finished product 3'are deviated by .DELTA.x as shown in FIG. 4, the deformation force shocks the sum of .DELTA.x and .DELTA.D during linear feeding of the slider 2. Increase to the value formed by. Therefore, the load of the ring rolling mill is shocked and the deformation noise is also sharply increased.

In this case, according to the pressure medium actuated damper type clamping and fixing device 10, rolling of the ring caused by maintaining the linear payout of the slider 2 and the hole eccentric by Δx of the ring-shaped semifinished product 3 '. It is possible to avoid disadvantages during processing. The bracket 7 is lifted by the shape roll 8 due to the load generated by the impact, whereby the working chamber 30 on the front side of the working piston 12 is contracted,
This simultaneously causes a pressure increase of the incompressible pressurized liquid. This rise in pressure of the pressurized liquid immediately causes the pressure medium pipe 3
5, acting on the pressure control device 36, which is adjusted to a predetermined hydraulic pressure in order to limit the clamping force applied when the bracket 7 is clamped. When the deforming force is high, the pressure control device 36 uses
It is designed as a pressure limiting valve for limiting the maximum clamping force between the machine and the machine body 1. Initially, the pressure limiting valve opens each time the ring-shaped semi-finished product 3'rotates, when a large wall portion generated when the hole is eccentric enters into the roll gap, the wall thickness decreases, and the deformation force decreases. Closes when dropped.

When the ring-shaped semi-finished products have different thicknesses, the bracket 7 can be vibrated with respect to the mandrel roll 4 together with the shaping roll 8. The advantage is that even if the ring thickness is changed significantly due to the rigidity of the ring rolling machine, which can be rolled only under the harmful vibration of the rolling machine or the generation of loud noise, the ring can be rolled without any problem. There is something that can be done.

A particularly effective adjustment is achieved by utilizing an electronically controlled proportional pressure limiting valve as the pressure control device 36. In that case, at the same time, by means of a computer-aided control of the clamping force, the bracket 7 can be firmly clamped together with the profiled roll 8 or vibrated in accordance with a predetermined characteristic curve at all times.

[0029]

According to the present invention, since the ring-shaped semi-finished product having a considerably large variation in wall thickness can be used, the economical efficiency in cold rolling the ring is enhanced. Further, the slider supporting the mandrel roll can be fed out by the speed control device according to a predetermined characteristic curve, and even if the hole of the ring-shaped semi-finished product is eccentric, the rolling tool is not overloaded.

[Brief description of drawings]

FIG. 1 is a front view of a ring rolling mill.

FIG. 2 is a cross-sectional view of a horizontally fixed bracket and a clamped fixing portion of a vertical column.

FIG. 3 is a schematic view of a partially rolled ring-shaped semi-finished product having concentric holes.

FIG. 4 is a schematic view of a partially rolled ring-shaped semi-finished product having eccentric holes.

[Explanation of symbols]

 1 Machine body 2 Slider 3 Ring to be rolled 3'Ring-shaped semi-finished product (work) 4 Mandrel roll 7 Bracket 9 Strut 11 Cylinder 12 Working piston 13 Piston rod 14 Shaft rod 21 Screw hole 22 Screw 23 Guide shaft 24 Hole 25 Guide Bushing 26 Strut guide 27 Mounting bolt 28 Adjustment screw 29 Adjustment nut 30 Working chamber 33 Pressure medium connection port 34 Liquid pressure source 35 Pressure medium piping 36 Pressure control device

Front Page Continuation (72) Inventor Wilfried, Lehmann Germany, Bad, Duben, Heidering, 18

Claims (7)

[Claims] 1. A mandrel roll supported by a retractable slider and a shape roll rotatably driven by a bracket supported by a vertical upright column are vertically arranged in the form of a structure group. In a ring rolling machine with a damping device for cold rolling a ring that can be rolled out in a radial direction according to a predetermined curve characteristic toward a rotationally driven shape roll, each upright column (9) A pressure medium actuated damper type clamping and fixing device (10) is provided between the bracket and the bracket (7), and the clamping and fixing device (10) is installed in the cylinder (1).
1) It has a single-acting working piston (12) with a piston rod (13) that can move in the axial direction, and this working piston (12) is a cylinder (11) and a bracket (7).
And the working chambers (30) at the front of the working piston (12) are respectively connected to the upright columns (9) by piston rods (13) and filled with an incompressible pressure medium, leading to a hydraulic pressure source (34). A ring mill with a damping device, characterized in that it is provided with a pressure medium connection (33). 2. The pressure medium contained in the working chamber (30) of the cylinder (11) is brought to a high pressure to clamp and fix the bracket (7) to the upright column (9) and the working piston (12). The rolling mill with a damping device according to claim 1, characterized in that the rolling mill is urged with a clamping force that is at least equal to or greater than the rolling force. 3. A hydraulic pressure source (3) for limiting the clamping force in addition to the hydraulic pressure source (34) acting on the working piston (12).
A variable adjusting element for controlling a pressure medium passage is provided as a pressure control device (36) in the pressure medium pipe (35) between the working chamber (30) and the ring (4) and the variable element is a ring to be rolled. 3. The ring rolling machine with a damping device according to claim 1, wherein the deformation resistance of (3) is controlled when the rolling resistance exceeds the rolling force, and is restored when the deformation resistance becomes smaller than the rolling force. 4. The pressure control device (36) is a direct control type pressure limiting valve, or an electronically controlled proportional pressure limiting valve when a tightening force is controlled by a computer. The ring rolling machine with a damping device according to any one of claims 1 to 3. 5. A piston rod (13) of an actuating piston (12) is connected to an upper end of an upright support column (9) via a shaft rod (14), and the upright support column (9) is screwed to the shaft rod (14). A screw hole (21) is provided in the lower end of the shaft rod (14) corresponding to the screw (22) provided in the upright support column (9) in order to perform a tight connection with the bracket (7). The ring rolling machine with a damping device according to any one of claims 1 to 4, characterized in that: 6. A guide shaft (23) extending in the axial direction is arranged at the lower end of the shaft rod (14), and the guide shaft (23) moves in the hole (24) of the guide bush (25) in the axial direction. The guide bush (25) is movably guided and is concentrically bolted to the column guide (26) provided on the bracket (7) by a mounting bolt (27), so that the guide shaft (23) of the shaft rod (14) is Following the range axially, adjust nut (2
8) A ring mill with a damping device according to any one of claims 1 to 5, characterized in that it is provided with an adjusting screw part (28) with. 7. The working piston (12) is positioned horizontally with respect to the cylinder (11) by adjusting the adjusting nut (29) with the bracket (7) resting on the upright column (9). , The inside of the cylinder (11) inside the working chamber (3
0) and the exhaust chamber (31) are divided into a ring rolling machine with a damping device according to any one of claims 1 to 6.