JPH0311846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for inserting a mandrel into a hollow body and positioning the tip of the mandrel in preparation for the start of rolling of the hollow body, in a continuous pipe rolling mill in which the mandrel is operated with speed control. The present invention relates to a charging device with means for longitudinal feeding to the rolling position and for holding the mandrel against the longitudinal forces acting on the mandrel.

The "charging device" here is responsible for operating mandrels and hollow bodies, and forms part of continuous tube rolling equipment that operates using mandrels. Common challenges for charging equipment include: inserting the mandrel into the hollow body and positioning the tip of the mandrel in preparation for the start of rolling the hollow body, joint longitudinal feeding of the hollow body and mandrel to the rolling position, and Includes individual or joint delivery to rolling lines.

The method of controlling the speed of the mandrel further includes coupling the mandrel to a correspondingly advancing holding device;
Receiving the longitudinal force acting on the mandrel and uncoupling for free flow of the mandrel or after returning the mandrel for replacing the mandrel are added.

Fundamentally, therefore, the working cycle time and productivity of the installation are essentially determined by the functionality of the charging device. Its function also becomes related to the rolling method employed. The conventional continuous tube rolling method does not take mandrel speed control into consideration, and the insertion, positioning, and longitudinal feeding of the hollow body and mandrel are performed by a chain-type feeding device on the rolling line.

Another known method controls the mandrel speed, creating a longitudinal pull on the mandrel holder. After the rolling process is completed, the mandrel is returned to its original position, with the mandrel connected to the rack-rod drive in the same manner as during forward movement. Insertion and positioning on the rolling line also take place with the stroke of the lever. As a result, the cycle time of the work is two to three times longer than with other methods.

Another method also operates with a controlled mandrel speed and a corresponding longitudinal pulling force, but the mandrel is released from the pulling force after the end of the rolling process and flows out with the rolled product.

The mandrel in controlled forward movement is connected to a chain drive and insertion and positioning takes place outside the rolling line.

It has also been proposed to control the mandrel speed to cause a similar longitudinal pull on the mandrel retainer. At the end of the rolling process, the longitudinal pull ceases and the mandrel is released to pass through the rolling mill. This mandrel is connected to a chain drive and insertion and positioning takes place outside the rolling line.

Two further systems, which are particularly suitable for implementing the invention, are characterized by controlling the mandrel speed in such a way that a longitudinal push and pull (load alternation) is exerted on the mandrel holder. The mandrel is connected to a rack-rod drive, and the insertion and positioning takes place outside the rolling line in a separate device parallel to the rolling line. In these systems, the release of the mandrel (or the stopping of the mandrel movement prior to reversing) takes place during the rolling process under longitudinal pulling force, in particular when the tip of the hollow body reaches the fourth roll stand. In such a system, compared to other systems, the demands on the performance of the charging device are the greatest and the difficulties associated with the load change and the release of the mandrel under pull load, which occur particularly in the rolling stage, are great.

However, the latter two methods have significant operational advantages, such as the ability to produce relatively long tubes with minimal cycle times, and are therefore desirable.

Already, mandrel holding means have been proposed for these methods to meet the requirements necessary for their implementation, but the chosen technical method requires significantly greater construction costs, especially in view of the original mandrel holding devices. In need of. This stems from the formal requirement to accept mandrel loading changes without choice and to release the mandrel at a given point under longitudinal tension. A known solution to this problem is to provide a toggle device on the trolley-shaped mandrel pushing block, which cooperates with the fork-shaped actual holding device. The movement of the holding device takes place via a rack rod which is journalled alongside the rolling line and whose speed is controlled by a direct current drive. When the mandrel is released, the fork-shaped cage is released and accelerated in the rolling direction by the folding of the toggle device to eliminate the peripheral pressure on the contact surface. Disengagement of the toggle device occurs progressively by overcoming the control curve. This method has the disadvantage that, as mentioned above, the construction cost is high, and the insertion and positioning of the mandrel must be performed outside the rolling line using a separate device.

In view of these problems and shortcomings, the present invention substantially simplifies and reduces the construction cost of a charging device for a continuous tube rolling mill that operates a mandrel at controlled speed, and also improves the insertion and positioning of the mandrel into the rolling line. The object of the present invention is to realize a charging device that accepts unloading, and the various means specified in the claims are used to solve the problem.

Here, the invention is based on the idea that the pushing force to be transmitted to the mandrel during the rolling engagement phase can also be exerted using the device which is necessary anyway for the insertion of the mandrel. This problem does not pose a problem for the actual holding device, which only absorbs the attractive forces that occur during the rolling process. Depending on the working method, the change in load from push to pull on the mandrel can occur as early as the first roll stand or at the latest when the hollow body head is gripped by the second roll stand, depending on the mandrel speed. . Therefore, the stroke required by the insertion locating device is not much larger than the net insertion locating stroke. If the pushing and pulling loads are shared between two independent chain devices, there is no need to incorporate a complicated holding device combined with a rack rod, and it is possible to send two chain drives, each of which takes on a load that only works in one direction. and can be used as a force transmission element.

Another feature of the present invention is that the chain is constructed as a double chain drive device, and a supporting roller having a feed diameter matching the mandrel or hollow body is mounted between both chain chains and is supported perpendicularly to the rolling line. We propose that the chain itself take over the function of the side roll table.

The inventors also propose a holding device in which two or more holding crossbeams arranged around the chain are each fitted with a cage in a fork-shaped configuration open to the mandrel side. The forks of the retainer surround the mandrel in the area of a reduced cross-section provided in front of its rear end, and the step formed by the transition of the reduced cross-section into the mandrel cross-section can abut the fork with its front side. be. With mandrels that are already designed in a similar manner in known holding devices, it is possible to connect and release the mandrels with this holding device without any problems. Upon release of the mandrel, the forked retaining chain is accelerated to a speed above that of the unobstructed run of the mandrel. This frees the holding device from the pulling force, so that the fork can be pivoted out of the area of the mandrel with a deflection of the holding chain.

The forward feeding of the mandrel for insertion, positioning and pushing is effected by pushers fixed to the chain crossbeams of the other chain.

Another feature of the invention is that the front face of the pushing end of the pusher is formed in the shape of an obtuse cone and engages concentrically with the correspondingly shaped front face of the mandrel head during pushing. In this case, the weight of the long pusher is supported by the carrier rollers of the double chain drive.

Finally, it is proposed that a hollow body stopper that can be raised and lowered to fix the position of the hollow body for mandrel positioning be installed between the mandrel holding chain and the first roll stand.

Hereinafter, the functions of the charging device of the present invention will be explained with reference to the accompanying drawings showing one embodiment.

The function of this charging device is the same whether the mandrel is released and passes through the roll stand or the mandrel is moved back up to stage 5 in FIG.

Reference numeral 1 in FIG. 1 denotes a mandrel insertion and positioning device consisting of a reversible chain 4 running around guide rollers 2, 3;
Moreover, a pusher 6 is attached to the chain crossbeam 5 on the running side so as to be concentric with the rolling line. The pusher 6 is a cylindrical rod, and can be concentrically engaged with a corresponding conical protrusion on the end surface of the mandrel head 9 through an obtuse conical recess 8 formed at its front end 7.

The mandrel 19 and the device for holding and longitudinally feeding the hollow body are designated by 10 in FIG.
It consists of an endless chain 13 running around 1 and 12. Two holding devices 14 and 15 are mounted at equal intervals around the chain 13 of the holding device, and travel together with the chain 13. holding device 14,
15, as shown in FIG. 2, comprises a fork-shaped retainer 16 that is open on the mandrel side and is attached to a retaining cross beam 27. In the opening 17 of the fork-shaped retainer,
The dimensions are such that the reduced cross-section end 18 of the mandrel 19 is accommodated, but the mandrel head 9 and the normal mandrel diameter are not accommodated. The end face 20 of the fork-shaped retainer 16 can thus abut against a stepped surface 21 formed between the reduced section 18 of the mandrel 19 and the mandrel head 9.

Hereinafter, the operating conditions will be explained step by step (Fig. 1).

In the first stage, the hollow body 22 and the mandrel 19 are transferred from the feeding device to the rolling line.

In the second stage, the mandrel 19 is
is pushed into the hollow body, and the reduced cross-section end 1 of the mandrel
8 is in a position that allows the fork-shaped retainer 16 to swing in as the chain 13 travels in the rolling direction.

In the third stage, the retainer 16 has already completed its rotation, and the hollow body 22 advances in the direction of the rolling mill 23 due to the advancement of the chain 13 and is stopped by the hollow body stopper 24 that has been raised in front of the rolling mill 23. The end 7 of the pusher in the rolling direction contacts the end surface of the mandrel head 9 and presses the stepped surface 21 of the mandrel head 9 against the end surface 20 of the cage 16. At this time, the pusher 6 passes over the end of its drive chain 4 and connects it to the chain 13 of the holding device.
has reached the area of Further, in the third stage, in preparation for the start of rolling of the hollow body 22, the mandrel tip 25 is positioned to a certain degree depending on the method, as shown in the figure.

In the fourth stage, the hollow body stopper 24 has already been lowered, and the hollow body 22 and the mandrel 19 are being rolled and fed synchronously by the progress of the chains 4 and 13. At this time, the mandrel head 9 is held between the retainer 16 and the pusher 6, and a pressing force is applied from the pusher 6 to the mandrel. However, at the latest when the leading end of the hollow body is gripped by the second stand of the rolling mill 23, the load changes from pushing to pulling depending on the method. The pusher 6 is stopped at its forwardmost end position, which corresponds to the position shown in the fourth stage, and its end 7 leaves the mandrel head 9.

In the fifth stage, the chain 13 continues to advance at a controlled speed, and the longitudinal pull exerted on the mandrel 19 is such that the end face 20 remains on the step face 2 of the mandrel head 9.
It is received by a retainer 16 which is in contact with the retainer 16. If the chain 13 and cage 16 continue to advance in a controlled manner so that the end of the hollow body 22 reaches the fourth stand of the rolling mill 23, then, depending on the implementation, the chain 13
The forward movement of the cage 16 and the chain 13 is stopped.
The reversal of the movement causes the mandrel to be pulled back or the chain 13 to be accelerated as shown in step 6 of FIG. In the latter case, the retainer 16 separates from the mandrel head 9 and the mandrel 19 continues to advance without speed control. The cage 16, which has increased in speed and moved away from the mandrel head 9 in the rolling direction, can be pivoted downward and removed from the reduced cross-section section 18 of the mandrel 19 at the changeover position of the chain 13, as shown in the seventh stage. . The mandrel then advances unhindered through the rolling mill 23.

When the holding device performs a reversing operation, that is, when the mandrel is moved backwards, one holder 16 is sufficient, but its movement range is limited to both guide rollers 1.
Must be limited to between 1 and 12. In addition,
If a device for laterally discharging the returned mandrels is required, it is possible, for example, to use a liftable element that stands between the carrier rollers of the existing holding chain 13.

In the case of a working method in which the mandrel passes through a rolling mill, it is preferable to provide the chain 13 with another cage 16a that enters the upper running side when the cage 16 rotates to the lower running side of the chain 13. This allows the charging device to charge hollow bodies with particularly high efficiency.

In principle, the charging device according to the invention can be equipped to selectively carry out the two aforementioned methods. This is desirable, for example, when it is desired to roll different sizes of tubular stock.

Next, the detailed structure of FIGS. 2 and 3 showing the cross section of the chain 13 of the holding device will be explained. Second
Reference numeral 26 in the figure indicates a chain of chains 13 running on both sides of the rolling line, and cages 16 are attached to cross beams 27 between both chains.
In FIG. 3, the chains of the chain 13 are designated by the same reference numeral 26, but here, instead of the crossbeam 27, a support roller 28 is pivotally supported between both chains 26. In the region shown, the carrier roller 2
8 is matched to the diameter of the hollow body 22 (dashed line). In the region of the chain 4 of the insertion device, the dimensions of the rollers 28 are large enough to support the pushers 6 in the direction of the rolling line.

[Brief explanation of the drawing]

In the accompanying drawings showing embodiments of the present invention, the first
The figure shows the operating process of the charging device according to the invention in six stages. FIG. 2 is a sectional view of one of the two holding crossbeams installed in the chain drive of the holding device, and FIG. 3 is a sectional view of one of the carrier rollers installed in the chain drive. FIG. 4 shows the configuration of the mandrel with the mandrel holder in the mandrel holding position and the pusher in the retracted position. FIG. 5 is a cross-sectional view across the mandrel taken along line A--B of FIG. 1, 4: Mandrel insertion positioning device and its reciprocating chain, 5, 6: Chain crossbeam and pusher,
7, 8: Push end of pusher and obtuse conical recess on its end surface,
9: Mandrel head (rear end), 10, 13: Mandrel and hollow body holding and longitudinal feeding device and its continuous running chain, 14, 15: Holding cross beam, 1
6: Fork type cage installed on the holding crossbeam, 19,
18: Mandrel and its reduced cross-section end, 20: Cage end face, 21: Step surface of mandrel head, 22: Hollow body, 23: Continuous rolling mill, 24: Hollow body stopper, 26, 28: Chain chain and between Pivotally supported carrier rollers.

Claims (1)

[Claims] 1. Positioning of the tip of the mandrel in preparation for inserting the mandrel into the hollow body and starting rolling of the hollow body in a continuous pipe rolling mill in which the mandrel is operated with speed control;
A charging device comprising means for longitudinally feeding a hollow body and a mandrel to a rolling position and for holding the mandrel against longitudinal forces acting on the mandrel, comprising: a) means for inserting and positioning the mandrel 19 on the rolling line; , a pusher 6 that cooperates with the rear end of the mandrel is attached via a chain crossbeam 5 to the upper running side of the chain 4 whose running direction can be reversed; b) means for holding and longitudinally feeding the mandrel 19 and the hollow body; , at least one mandrel rear end 18 holding device 14, 15 is attached to the chain 13 that runs continuously in the rolling direction; c. both chains 13, 4 are capable of speed control independently of each other and the rolling line is The chain 13 for holding the mandrel is located on the side of the rolling mill 23, and the pusher 6 is made of a cylindrical rod located concentrically with the rolling line, Charging device, characterized in that the body is provided with such a length that when the chain crossbeam 5 reaches its end position, the front end of the bar enters the region of the chain 13 for holding the mandrel 19. 2 The chain 13 for holding the mandrel is configured as a series chain drive device, and both chain series 2
2. Charging device according to claim 1, characterized in that the carrier rollers (28), which are journalled at right angles to the rolling line, have a feed diameter matched to the mandrel (19) or the hollow body. 3. The holding means 10 consists of two or more holding crossbeams 14, 15 arranged around the chain 13, to which a retainer 16 of fork-shaped configuration open on the mandrel 19 side is attached and The retainer forks surround the mandrel 19 at a reduced cross-section section 18 provided in front of the mandrel rear end 9;
The step portion 21 formed by the transition of the reduced cross-section portion to the mandrel cross-section is the end surface 2 of the fork 16.
The charging device according to claim 1, characterized in that it can come into contact with zero. 4. The pushing end 7 of the pusher 6 has an obtuse conical shape 8 on the front surface, and can engage concentrically with the correspondingly shaped opposing end surface of the mandrel head 9 during pushing. Charging equipment as described in section. 5. A patent claim characterized in that a liftable hollow body stopper 24 is provided between the chain 13 for holding the mandrel 19 and the first roll stand and can fix the position of the hollow body for positioning the mandrel. Range 1st term 2nd term 3rd term
The charging device according to item 1 or 4.