JP2871512B2 - Material supply method to pipe cutting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying a material to a tube cutting machine when a plurality of materials are cut in parallel by using a plurality of tube cutting machines arranged in parallel.

[0002]

2. Description of the Related Art In cold tube rolling by a cold pilger mill, a so-called extruded tube manufactured by a hot extrusion method is used as a raw tube. This extruded tube is manufactured as a long tube longer than the raw tube length in terms of efficiency and the like, and is cut into a short tube having a length convenient for rolling before being subjected to cold tube rolling.

In the cutting of such an extruded tube, a plurality of materials are often cut in parallel using a plurality of tube cutters in terms of efficiency. Such a simultaneous and parallel cutting and a method of transporting the material in the cutting will be described with reference to FIG.
In the simultaneous and parallel cutting, a plurality of pipe cutting machines 1 arranged in parallel are used. Each pipe cutting machine 1 cuts a raw material one by one using a rotary grindstone. The raw material sent from the upper process line is supplied in parallel to the plurality of pipe cutting machines 1 by the inlet side transport equipment 2, and is simultaneously cut by the plurality of pipe cutting machines 1. The cut material is carried out to the lower process line by the delivery equipment 3.

In such simultaneous and parallel cutting, what is called a lot management is very important so that a raw material sent in lots is not mixed with another lot after cutting. For this reason, a method called “first-in first-out” is generally adopted as a method for controlling the transport of the material. This means that the material supplied first to the pipe cutting machine is always carried out of the pipe cutting machine first. For example, it is assumed that the materials are sequentially supplied to the pipe cutting machines No. 1 to No. 3. In that case, No. 1
After unloading of the material with the pipe cutting machine of No. 2, the material is unloaded with the pipe cutting machine of No. 2, and after that, the unloading of the material is started with the pipe cutting machine of No. 3.

JP-A-59-97917 discloses a method of flexibly selecting and using a plurality of pipe cutting machines in order to improve the distribution efficiency in simultaneous and parallel cutting. Management is treated as the most important item.

[0006]

However, whether the first-in first-out method or the other method, the conventional transport control method giving priority to lot management has the following problems.

In a plurality of pipe cutting machines used for simultaneous and parallel cutting, as described above, a rotary grindstone is used for pipe cutting. The rotating grindstone wears with use and is replaced with a new one when the amount of wear reaches a limit value. Normally, this exchange is performed when there is no material in the tube cutting machine. However, when cutting extruded tubes, the thickness of the tube is large, the amount of wear per cut is large, and one material is cut into multiple pieces. Despite the recent tendency of multiple picking, the amount of wear reaches a limit during cutting.

When the wear amount of the rotary grindstone reaches a limit value during the cutting of the pipe, the pipe cutting machine is temporarily stopped, the material being cut is taken out from the cutting machine, and the material is set again after replacing the rotary grindstone. Then, a procedure of restarting the disconnection is required. Therefore, it takes much longer time to replace the rotating grindstone than normal replacement.

[0009] When such a situation occurs in simultaneous and parallel cutting, in the case of first-in first-out material, the exchanging operation is completed by a tube cutting machine for exchanging a rotating grindstone, and until the re-cutting and discharging of the material is completed, another cutting is performed. No material is discharged from the tube cutting machine. Therefore, despite the existence of a plurality of pipe cutting machines, all the pipe cutting machines are stopped for a long time, resulting in a significant decrease in the transfer rate.

[0010] When the rotary grindstone is replaced with a specific tube cutting machine whose life has reached the end of its life, even if the control of first-in first-out material is interrupted and cutting is continued by another pipe cutting machine, the specific pipe is cut. Since the material of the previous lot remains in the cutting machine, it is impossible to process the material of the next lot until the replacement of the grindstone is completed and the material is discharged. Therefore, a decrease in the transfer rate due to the waiting time is inevitable.

In the method disclosed in Japanese Patent Application Laid-Open No. 59-97917, it is considered that the same problem occurs because the exchange of the rotating grindstone during the cutting is not considered.
Since the requirements other than the lot management are also taken into consideration, it is not possible to deny the risk that the lot management will be incomplete when an unexpected situation occurs, such as replacing the grindstone during cutting.

An object of the present invention is to provide a method of supplying a material to a pipe cutting machine which can completely perform lot management and can minimize a decrease in a moving rate due to replacement of a rotary grindstone.

[0013]

According to the present invention, there is provided a method for supplying a material, comprising supplying a material in parallel to a plurality of tube cutting machines which are arranged in parallel and each of which cuts one tube at a time using a rotary grindstone. When a plurality of materials are cut by a cutting machine simultaneously in parallel, the amount of wear of the rotary grindstone assuming that each tube cutting machine cuts the material before loading the material into each tube cutting machine To determine whether the wear amount reaches the service limit during the assumed cutting, and if the usage limit is found to be reached during the assumed cutting, supply the material to the applicable pipe cutting machine. It stops and supplies the material only to other pipe cutting machines.

[0014]

According to the material supply method of the present invention, if it is predicted that the rotating whetstone will reach the service limit during cutting, no material is loaded into the tube cutting machine. By continuing to supply the material to other tube cutting machines, the cutting operation continues. In a pipe cutting machine in which it is predicted that the rotating grindstone will reach the service limit during cutting, the rotating grindstone is replaced, but since there is no material here, the replacement can be completed in a short time. If the processing of the current lot is completed by another pipe cutting machine during the replacement of the rotary grindstone, the material of the previous lot is transferred to the pipe cutting machine being replaced even if the next lot of material is processed by another pipe cutting machine. Since there is no remaining, there is no possibility that lot management will be incomplete.

That is, in the material supply method of the present invention, the decrease in the transfer rate due to the replacement of the rotary grindstone is caused only by the loss time required for the normal replacement, and the situation where the transfer rate is further reduced is avoided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the case where the present invention is carried out on the cutting line shown in FIG. FIG. 2 is a flowchart showing the processing process.

In this embodiment, the material is basically conveyed in parallel to the three pipe cutting machines 1 by the first-in first-out method. In addition, the wear amount (unit wear amount) of the rotating grindstone when one material is cut by the pipe cutting machine 1 before the operation is empirically obtained according to the material dimensions of the material.

When the work is started, it is checked whether or not the material can be supplied before the material is loaded in each pipe cutting machine 1, and when the supply is possible, the cumulative wear of the rotary grindstone when it is assumed that the material has been cut. The amount is predicted based on the unit wear amount. Then, the predicted cumulative wear amount is compared with the limit value, and the material is supplied to the pipe cutting machine 1 only when it is determined that the cumulative wear amount does not reach the limit value.

When this state continues in any of the three pipe cutting machines 1, the material is conveyed to these pipe cutting machines 1 by the first-in first-out method. That is, No. 1,
When the material is supplied in the order of 2 and 3, after the material is discharged from No. 1, the material is supplied to the tube cutting machine and the material is discharged from No. 2. After discharging the material from No. 2, supply the material to the tube cutting machine and
o. Discharge material from 3.

One of the three tube cutters 1, for example N
o. When the cutting and discharging of the material is completed in 1 and it is determined that the cumulative wear amount of the rotary grindstone reaches the limit value for the next material, the material is not supplied to No. 1 and No. 2 or Turn to 3. If it is determined in Nos. 2 and 3 that the accumulated wear amount does not reach the limit value, the processing of the material is continued by the first-in, first-out method using the two pipe cutting machines. And No.
In step 1, the replacement work of the rotary grindstone is performed.

Thus, even during the replacement of the rotary grindstone, the cutting of the material is continued by means other than the tube cutting machine, and the transfer rate is improved. In addition, in No. 1 where the rotating whetstone is replaced, charging of the material is stopped beforehand and no material remains, so the replacement work can be completed in the same short time as normal replacement, which also improves the transfer rate. To contribute.

When the processing of the material in the current lot is continued when the replacement of the rotary grindstone is completed in No. 1, the processing of the remaining material is continued using three tube cutting machines. If the processing of the current lot material has been completed during the replacement of the grinding wheel, the other two pipe cutting machines, namely N
o Start cutting the next lot of material using steps 2 and 3.
Even so, there is no possibility that the lot management will be incomplete because no material of the previous lot remains in No. 1. By doing so, the processing of the next lot material is continuously started in Nos. 2 and 3 without waiting for the completion of the replacement work in No. 1 and the transfer rate is further improved.

[0023]

As described above, according to the material supply method of the present invention, when simultaneous and parallel cutting is performed using a plurality of tube cutters arranged in parallel, the material of the current lot can be replaced even during the replacement work of the rotary grindstone. Enables economic processing. Further, it is possible to continuously process the material of the next lot as well as the current lot. In addition, the replacement time of the rotating grindstone can be reduced. Therefore, the moving rate of the pipe cutting machine can be greatly improved. Further, when the next lot material is continuously processed, there is no possibility that the lot management becomes incomplete.

[Brief description of the drawings]

FIG. 1 is a layout diagram illustrating a configuration example of a pipe cutting facility that performs simultaneous and parallel cutting.

FIG. 2 is a flowchart showing a processing process according to the embodiment of the present invention.

[Explanation of symbols]

 1 Pipe cutting machine 2 Inlet transport equipment 3 Outlet transport equipment

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B24B 27/06 B24B 41/06

Claims (1)

(57) [Claims] 1. A material is supplied in parallel to a plurality of tube cutting machines which are arranged in parallel and each of which cuts a tube one by one using a rotary grindstone, and a plurality of materials are simultaneously and concurrently processed by the plurality of tube cutting machines. When cutting, predict the amount of wear of the rotating grindstone when assuming that the material was cut by each pipe cutting machine before loading the material into each pipe cutting machine, and wear it during the assumed cutting. Judge whether the amount reaches the usage limit.If it becomes clear that the usage limit will be reached during the assumed cutting, stop supplying the material to the corresponding pipe cutting machine and supply the material only to other pipe cutting machines. Material supply method to a pipe cutting machine, characterized by continuing.