JPH0360563B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cold pilger mill that cold-rolls a raw pipe as a material to be rolled into a perfect circle with the same diameter and the same wall thickness in the axial direction, and further relates to More specifically, it relates to the Pilger Mill, which has a simple structure, low equipment cost, easy maintenance, and is excellent in terms of accuracy.

[Conventional technology]

As shown in FIG. 1, a cold pilger mill of the type used for manufacturing seamless pipes passes material 23 fed along a mandrel 22 into a tapered section at the tip of the mandrel 22. Rolling is performed by the forward and backward movement of a pair of upper and lower rolling rolls 4, 4 with special calibers, and compared to other pipe-making machines, it is possible to achieve a greater degree of processing, and has a high pipe-manufacturing capacity, with uneven thickness. It is said that cold-rolled pipes with excellent dimensional accuracy can be manufactured with a low degree of occurrence.

As mentioned above, this type of mill is not so difficult in principle, but in actual machines, the material 23 and the mandrel 22 are heated to a certain level each time the rolling rolls 4, 4 make one reciprocation, that is, each time one rolling process is completed. Since it is necessary to provide angular rotation in the circumferential direction, the structure becomes extremely complex. FIG. 2 schematically shows the overall structure of a conventional cold pilger mill of this type in a perspective view.

Although the mandrel 22 and the material 23 are not shown in FIG. 2, the tip of the mandrel 22 is positioned between the rolling rolls 4, 4, and the tail end is fixed with a mandrel chuck 15. The movement of the material 23 in the circumferential direction is regulated by the inlet chuck 16 and the outlet chuck 17 before and after the rolling rolls 4, 4, and the tail end is connected to the feed carriage 10.
engage with.

Now, to explain the overall structure of a conventional cold pilger mill of this type with reference to FIG. 2, 1 is a main electric motor that rotates a crankshaft 2 at a constant speed and rotates a roll stand 3 connected to the crankshaft 2 at a constant cycle. A pair of upper and lower rolling rolls 4, 4, which are pivotally supported by a roll stand 3 which is moved back and forth, are rotated by a rack and pinion 5 as the roll stand 3 moves back and forth, thereby rolling the material. This is the rolling mechanism.

The rotation of the crankshaft 2 is also transmitted to the feed cam 9 via the bevel gear 6, line shaft 7, and bevel gear 8, and the feed carriage 10 is advanced every time the roll stand 3 makes one reciprocation, that is, every time one rolling process is completed. to move the material. When the movement of the material is finished, the transmission 11 of the line shaft 7 is returned to its original position in preparation for the next movement of the material. The above is the material feeding mechanism.

The line shaft 7 also drives the rotation cam 13, and rotates the second line shaft 14 every time one rolling process is completed. The rotation of the line shaft 14 is transmitted to a mandrel chuck 15, a material inlet chuck 16 and an outlet chuck 17, causing the material and the mandrel to rotate in the circumferential direction after each rolling process. This is the material rotation mechanism and mandrel rotation mechanism.

[Problem that the invention seeks to solve]

By the way, the reason why the conventional cold pilger mill adopts the above-mentioned complicated structure is to precisely synchronize the material feeding, material rotation, and mandrel rotation during material rolling. However, the parts indicated by thick lines in FIG. 2 directly perform material rolling, material feeding, material rotation, and mandrel rotation, and the remaining parts indicated by thin lines are merely power transmission mechanisms. That is, most cold pilger mills have ancillary power transmission mechanisms, and their structures are complex, which complicates the overall structure and causes various problems.

The present invention focuses on the unique structure of this type of cold pilger mill, and divides the entire mill into four mechanisms: a rolling mechanism, a material feeding mechanism, a material rotation mechanism, and a mandrel rotation mechanism, and each mechanism is equipped with a dedicated motor. By independently and centrally controlling the dedicated motors of other mechanisms based on the rolling phase of the rolling mechanism, the mechanical interlocking mechanism, which occupies a large proportion of the mill structure, is replaced with an electrical interlocking mechanism, and the overall structure is improved. The purpose of the present invention is to provide a cold pilger mill that has a significantly simplified width and improved rolling accuracy, operating efficiency, and roll durability.

[Means for solving problems]

That is, in the cold pilger mill of the present invention, as shown in FIG.
A rolling mechanism that rolls the material at a constant cycle by a pair of upper and lower tapered carrier hole circumferential rolls 4, 4 driven by a roller, a rolling phase detector 18 built into the rolling mechanism, and a carriage 10 and a dedicated drive motor. At 19, a material feeding mechanism feeds the material in the axial direction, and the material and the mandrel are transferred to the inlet chuck 1.
6. A material rotation mechanism and a mandrel rotation mechanism that rotate the material in the circumferential direction using the outlet chuck 17 and the mandrel chuck 15 and dedicated drive motors 20 ₁ to 20 ₃ , and the material rotation mechanism based on the signal from the rolling phase detector 18 . This cold pilger mill has an extremely simple structure and includes a drive motor 19 of the feed mechanism and a controller 21 that sends operation command signals to each of the drive motors 20 ₁ to 20 ₃ of the material rotation mechanism and the mandrel rotation mechanism.

[Effect]

Driven by the main electric motor 1, the rolling rolls 4, 4 rotate and reciprocate between the forward limit [Fig. 1 (X)] and the backward limit [Fig. 1 (Y)], rolling the material at a constant cycle. do. The controller 21 controls the drive motor 19 of the material feeding mechanism and the drive motors 20 ₁ of the material rotation mechanism and the mandrel rotation mechanism during a so-called idle period from the end of one rolling process to the start of the next rolling process.
~20 ₃ and send the operation command signal to the carriage 1.
0 is advanced a predetermined distance and at the same time the mandrel chuck 15, inlet chuck 16 and outlet chuck 17 are rotated by a predetermined angle. During the idle period, that is, the rolling rolls 4, 4 are at their forward limit [Fig. 1 (X)]
When folding back the material, the material is released from the restraint by the rolling rolls 4, 4. Therefore, the movement of the carriage 10 advances the material a predetermined distance, and the rotation of the chucks 15, 16, 17 moves the material. Rotates a predetermined angle together with the mandrel. In this way, the material is rolled to a predetermined length at a time while changing the rolling direction.

Dedicated motors 1, 1 for all of the rolling mechanism, material feeding mechanism, material rotation mechanism, and mandrel rotation mechanism
The cold pilger mill of the present invention, which is equipped with 9,20 ₁ to 20 ₃ , is not inferior in terms of functionality compared to conventional mills as described above, but also has low equipment costs and is easy to maintain, as will be described later. In addition to being good in performance, it is also excellent in precision, and it is also significantly superior in terms of operating efficiency and roll life.

〔Example〕

The present invention will be explained below based on the embodiment shown in FIG.

The rolling mechanism includes a main motor 1, a crankshaft 2 connected to the main motor 1, and a roll stand 3 connected to the crankshaft 2 and movable back and forth. A pinion gear ₅₁ is coupled to the rotating shafts of the pair of upper and lower rolling rolls 4, 4 incorporated in the roll stand 3, and this is coupled to a fixed rack ₅₂ to control the rolling rolls 4, 4 in the forward and backward movement of the roll stand 3. and advance limit [Fig. 1 (X)]
and the retraction limit [Fig. 1 (Y)].

A rotation angle detector 18, which is a rolling phase detector, is attached to the crankshaft 2, and detects the rolling phase from the rotation angle of the crankshaft 2, that is, which stage of one rolling process the rolling is currently in. In other words, this rolling phase is the position of the roll stand 3 or the rotational position of the rolls 4, so it can also be detected from the roll stand position or the rotation angle of the rolls. It is possible.

The material feed mechanism includes a feed carriage 10 provided on the material input side of the roll stand 3, a carriage feed screw 12 screwed into the feed carriage 10, and a drive motor 19 (further connected to the carriage feed screw 12 via a gear). It consists of a servo motor).
The carriage feed screw 12 is movable only in the circumferential direction,
It is designed not to move in the axial direction.

The mandrel rotation mechanism consists of a rotatable mandrel chuck 15 and a drive motor 20 (servo motor) connected to this via a gear, and the material rotation mechanism is provided on the material input side and the material output side of the roll stand 3. It consists of a rotatable inlet chuck 16 and an outlet chuck 17, and drive motors 20 ₁ and 20 ₃ (both servo motors) connected to these through gears. mandrel chuck 15
completely fixes the mandrel, whereas the inlet chuck 16 and the outlet chuck 17 restrict only the circumferential movement of the material, i.e. rotational movement, and allow axial movement of the material in order to allow material feeding. It is becoming more and more common.

The controller 21 that sends operation command signals to the drive motor 19 of the material feeding mechanism and the drive motors 20 ₁ to 20 ₃ of the material rotation mechanism and the mandrel rotation mechanism is configured as follows. That is, the controller 21 receives a rolling phase signal from the rotation angle detector 18 connected to the crankshaft 2, and based on this input signal, the controller 21 determines whether one rolling process is completed (the rolling rolls 4, 4
During the so-called idle period up to the forward limit (immediately after returning to the forward limit (X) in FIG. sending,
At the same time, the mandrel chuck 1 is transferred to the drive motors 20 ₁ to 20 ₃ of the material rotation mechanism and the mandrel rotation mechanism.
5. It is designed to send a rotation angle command or rotation speed command necessary to rotate the inlet chuck 16 and the outlet chuck 17 by a predetermined angle. The controller 21 is also configured to be able to freely move the carriage 10 in response to an external command.

According to the cold pilger mill configured as described above, pipe production is carried out as follows.

Prior to pipe making, the tail end of the mandrel (FIG. 1, 22) is fixed to the mandrel chuck 15, and its tip is positioned between the rolling rolls 4, 4. The feed carriage 10 is returned to the backward limit by giving an external command to the controller 21. The tail end of the material is fixed to the feed carriage 10, and the leading end is connected to the inlet chuck 16, the rolling rolls 4, 4 and the outlet chuck 1.
7, the inlet chuck 16 and the outlet chuck 1
Hold it at 7.

When the above preparations are completed, the main motor 1 is driven. Driven by the main electric motor 1, the rolling rolls 4, 4 rotate and reciprocate between the forward limit [Fig. 1 (X)] and the backward limit [Fig. 1 (Y)] as described above, and keep the material constant. Roll in cycles. The controller 21 controls the drive motor 19 of the material feeding mechanism and the drive motors 20 ₁ to 20 ₃ of the material rotation mechanism and the mandrel rotation mechanism during the so-called idle period from the end of one rolling process to the start of the next rolling process. An operation command signal is sent to the mandrel chuck 15, the inlet chuck 16, and the outlet chuck 17 at a predetermined angle at the same time as the carriage 10 is advanced a predetermined distance. During the idle period, i.e. the rolling roll 4,
Since the material is released from the restraint by the rolling rolls 4, 4 when the roller 4 turns back from the forward limit (FIG. 1 (X)), the material advances a predetermined distance by the movement of the carriage 10, and The rotation of the chucks 15, 16 and 17 rotates the material together with the mandrel by a predetermined angle. As a result, the material is rolled to a predetermined length at a time while changing the rolling direction.

When the rolling is nearing the end, an external command is sent to the controller 21 to move the carriage 10 to the backward limit and set a new material, thereby continuously rolling a plurality of materials.

〔Effect of the invention〕

As is clear from the above description, in the cold pilger mill of the present invention, the rolling mechanism, material feeding mechanism, material rotation mechanism, and mandrel rotation mechanism are operated by dedicated drive motors without mechanically linking them, and are driven by electric signals. Since each mechanism is linked to each other, the power transmission mechanism, which traditionally occupied a large proportion of the structure of mills, is eliminated, and the overall structure is significantly simplified, resulting in low equipment costs and extremely easy maintenance. Become something.

_For example, when comparing _the conventional mill shown in FIG. 2 with the mill of the present invention shown in FIG. The power transmission mechanism shown by thin lines in FIG. 2, that is, the bevel gear 6, line shaft 7, bevel gear 8, feed cam 9, transmission 10, rotating cam 13, line shaft 14, and many other gears are omitted, and the structure The effect of simplification is enormous, and the associated cost reduction and maintainability improvement effects are also enormous.

In particular, in conventional mills, the material feed mechanism advances the carriage 10 using the feed cam 9, so the carriage feed screw 11 must be returned to its original position each time it moves forward.Structurally, it has two functions: forward movement and return. Although a mechanism is required, in the mill of the present invention, the carriage 10 can be moved only by rotating the feed screw 11, making it possible to greatly simplify the structure.

Furthermore, in the cold pilger mill of the present invention, since the material feeding mechanism, material rotation mechanism, and mandrel rotation mechanism are directly driven by a dedicated drive motor, it is expected that the synchronization accuracy between each mechanism will be improved.

In other words, the purpose of mechanically connecting each mechanism in a conventional mill is to accurately synchronize the operations of each mechanism, but in reality, the connection mechanism becomes complicated and mechanical backlash such as backlash increases. Therefore, the expected effect was not obtained, and instead, each mechanism was separated and each mechanism was provided with an independent drive motor.
By electrically synchronizing the operations of each mechanism, improved synchronization accuracy can be expected.

In addition, the cold pilger mill of the present invention eliminates the power transmission mechanism, eliminates the need for the power used to drive the power transmission mechanism, and allows the power to be used more effectively, resulting in savings in power costs. .

Additionally, cold pilger mills generally roll tubes of various materials and sizes. In this case, in order to improve product dimensional accuracy, product quality, and rolling efficiency, it is desirable to change the feed rate and rotation angle of the material depending on the material and size. However, in conventional mills, material is fed and rotated by each cam,
The feed amount and rotation angle are determined by the shape of each cam, so if you try to change the feed amount and rotation angle depending on the material and dimensions, the cam will need to be replaced each time, resulting in a significant decrease in mill operating efficiency. It turns out. Therefore, conventionally, it has been customary to share cams even if it means sacrificing the dimensional accuracy and quality of the finished product.

However, in the mill of the present invention, dedicated drive motors are provided for each of the material feed mechanism and material rotation mechanism, so stepless setting changes for the material feed amount and rotation angle can be made easily and in a very short time using an operation panel, etc. You can do it. As a result, it is possible to set the optimal feed amount and rotation angle each time the material or dimensions are changed without being restricted by the cam, resulting in significant improvements in product dimensional accuracy and product quality. Moreover, since there is no need to replace the cam at all, mill operating efficiency is also improved.

Furthermore, in cold pilger mills, strict control of the pore size and profile of the pore roll is required in order to impart high dimensional accuracy to the finished product. In conventional mills, the rotation angle of the material is uniquely determined by the shape of the cam, and since the cam is not replaced frequently, a concentrated load is repeatedly applied to a part of the hole mold, resulting in uneven wear on the hole mold. However, roll life was becoming a problem.

However, in the mill of the present invention, the rotation angle of the material can be changed steplessly at any time, so the rotation angle can be changed cyclically around the optimum rotation angle determined by the material and dimensions. The wear of the mold rolls can be dispersed, making it possible to greatly extend the life of the rolls.

Furthermore, in the mill of the present invention, since the material rotation mechanism and the mandrel rotation mechanism are independent, it is possible to improve product dimensional accuracy and product quality.

In other words, the material rotation mechanism and the mandrel rotation mechanism have conventionally been mechanically connected in series to the main motor as shown in Figure 2, and the relative movement between them is virtually non-existent except for play. not exist. As a result, uneven wear occurred on the mandrel, reducing the roundness of the finished product. However, in the mill of the present invention, material rotation and mandrel rotation are performed by a dedicated drive motor, so relative rotation can be applied between the material and the mandrel, and uneven wear of the mandrel can be prevented. Moreover, the material is rotated relative to the mandrel between forward rolling and return rolling,
Since it is possible to prevent both from seizing, the dimensional accuracy and quality of the finished product can be further improved.

In addition, in the mill of the present invention, both the front and rear chucks in the material rotation mechanism are driven by dedicated motors, so that no twist occurs in the material during rolling, which also effectively contributes to improving product dimensional accuracy and product quality.

As described above, in the cold pilger mill of the present invention, the rolling mechanism, material feeding mechanism, material rotation mechanism, and mandrel rotation mechanism are all independently driven by dedicated motors, so that the cold pilger mill of the present invention is improved in terms of equipment by eliminating the power transmission mechanism. The overall structure is greatly simplified, resulting in significant advantages in terms of equipment costs and maintainability.

In terms of power cost, the power used to drive the power transmission mechanism is unnecessary.

Mechanical play is eliminated in terms of product dimensional accuracy and product quality, material twisting during rolling is prevented, and material feed rate and rotation angle that are optimal for the material and dimensions can be set at will without being restricted by a cam. can,
A synergistic effect such as prevention of uneven wear of the mandrel and seizure between the material and the mandrel provides an extremely large gain.

Furthermore, the need for cam replacement improves mill operation efficiency.
Also, not being constrained by a cam brings about a significant gain in terms of roll life, and the effect is enormous over a wide range.

[Brief explanation of drawings]

Figure 1 is a diagram of the operating principle of a cold pilger mill.
FIG. 2 is a perspective view illustrating the overall structure of a conventional cold pilger mill, and FIG. 3 is a perspective view illustrating the overall structure of the cold pilger mill of the present invention. In the diagram, 1...main electric motor, 2...crankshaft,
3... Roll stand, 4... Rolling roll, 10... Feed carriage, 12... Carriage feed screw, 15
...Mandrel chuck, 16...Inlet chuck, 1
7... Outlet chuck, 19... Drive motor of material feeding mechanism, 20 ₁ - 20 ₃ ... Drive motor of material rotation mechanism and mandrel rotation mechanism, 21... Controller, 22
...Mandrel, 23...Materials.

Claims (1)

[Claims] 1 A cold pilger mill that cold-rolls a raw pipe as a material to be rolled into a perfect circle with the same diameter and the same wall thickness in the direction of the pipe axis, and is connected to a crankshaft 2 driven by a motor 1 to reciprocate Moving stand 3
is provided with a pair of upper and lower tapered carrier hole surrounding rolls 4, 4 that rotate forward and backward in accordance with the reciprocating movement,
a rolling mechanism that rolls the material at a constant cycle using the rolls 4, 4; a rolling phase detector 18 incorporated in the rolling mechanism; and a rolling phase detector 18 located upstream of the rolling mechanism;
A carriage 10 that feeds the material in the axial direction by a screw feeding mechanism and its dedicated drive motor 19
cylindrical chucks 16 and 17 arranged before and after the rolling mechanism to allow movement of the material in the axial direction and prevent rotation in the circumferential direction, and motors 20 ₂ and 20 ₃ dedicated to rotating the material in the circumferential direction. The proximal end of a mandrel, which is fixedly installed upstream of the material rotation mechanism and the material feeding mechanism and whose tapered tip faces the reciprocating movement area between the rolling mechanism rolls 4, 4, is moved in the axial direction. a mandrel rotation mechanism comprising a mandrel chuck 15 that is fixed immovably and rotates in the circumferential direction and a dedicated drive motor 20 ₁ for the mandrel chuck 15; and the material feeding mechanism during the idle period of the rolling phase detected by the rolling phase detector 18;
A cold pilger mill characterized in that it is equipped with a controller 21 that outputs required operation command signals for rolling to motors 19, 20 ₂ , 20 ₃ and 20 ₁ dedicated to the material rotation mechanism and the mandrel rotation mechanism.