JPH0313216A - Housing for cluster mill and its manufacture - Google Patents

Abstract

PURPOSE:To realize a long service life by constituting the housing by dividing it into blocks placed so that the rolling direction of a steel plate becomes perpendicular to the load direction at the time of operation, welding them by multi- electrode electroslag, and bringing a necessary part to build-up by a wear resistance metal. CONSTITUTION:An element block made of a rolled plate is placed so that the rolling direction of the rolled plate becomes the direction being roughly perpendicular to a rolling load at the time of operation. In this state, a center block 7 is assembled so that the rolling direction of the rolled plate becomes perpendicular to the direction of a rolling load 20A, side face blocks 5, 6 are assembled so that the rolling direction of the rolled plate becomes perpendicular to the direction of a rolling load 20B, and welding is executed by multi-electrode electroslag welding suitable for welding of a large cross section. Subsequently, a high strength and/or wear resistant metallic layer 12 is formed by executing buildup welding to the bore surface 13. In such a way, an excellent internal quality can be secured, a long service life is realized, and the manufacturing process can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a housing for a cluster mill and a method for manufacturing the same, and more particularly to a housing for a cluster mill having a welded steel plate structure and a method for manufacturing the same.

[Conventional technology]

The cluster mill housing has a shape in which a pair of rolling rolls and a plurality of backup rolls are incorporated,
It also has a structure in which each of the back rolls is supported on the bore surface via a bear link. Conventionally, the housing for this cluster mill has been made of a highly adjustable one-piece housing in order to obtain rigidity, as described in Japanese Patent Application Laid-Open No. 50-46544.

[Problem to be solved by the invention]

In conventional housings for cluster mills, since they are made of BM, defects unique to castings such as cavities occur on the bore surface and corners, making it difficult to maintain internal quality. .

In addition, the wear resistance of the bore surface affects the life of the cluster mill housing, and in order to improve it, it was necessary to adjust the cast steel composition by controlling the chemical composition. However, this involves upgrading the material in order to improve wear resistance only on the bore surface, which poses a problem in terms of economy.

A first object of the present invention is to provide a high-quality housing for a cluster mill that has improved internal quality by using a rolled steel plate, and a method for manufacturing the same.

A second object of the present invention is to provide a housing for a raster mill that is long-life and inexpensive by adding wear resistance by performing tactile welding to the bore surface, and a method for manufacturing the same.

[Means to solve the problem]

The first object is to have upper and lower mill blocks each having an inner surface serving as a bore surface, and each of the upper and lower mill blocks is divided into a plurality of element blocks made of rolled steel plates, and At least some of these plurality of element blocks are arranged so that the rolling direction of the rolled steel plate constituting them is approximately perpendicular to the direction of the rolling load acting on these element blocks during rolling, and the plurality of element blocks are The blocks are closely related to the cluster mill housing, which is characterized in that the blocks are joined by welding.

The welding of a plurality of element blocks is preferably carried out by a number t [
y Electroslag welding is used.

In addition, the first objective is to prepare a central block made of rolled steel plate placed in the area that provides the bore surface and two side blocks made of rolled steel plate placed on both sides of the central block, and weld these together. to form a mill block, prepare two of these mill blocks, perform i-machining on each to form a surface that will become a bore surface, and make the two mill blocks into upper and lower mill blocks, respectively. This is achieved by a method of manufacturing a housing for a cluster mill, which is characterized in that the upper and lower mill blocks are joined by welding to form an integral structure.

The central block is preferably constructed by preparing a main block and two intermediate pieces disposed at opposing positions on the side surface of the main block that provides the bore surface, and joining these by welding.

The second object is to have at least one mill block made of rolled steel plate, and to have 8! The surface obtained by machining has high strength and/or
Alternatively, there is provided a housing for a cluster mill, characterized in that the bore surface is formed by overlay welding a wear-resistant metal.

The second object is to provide, in the above-described method for manufacturing a housing for a cluster mill, after subjecting the rolled steel plates constituting the two mill blocks to pre-processing with an FI machine to form a surface that will become the basis of the bore surface. This is achieved by a method for manufacturing a housing for a cluster mill, which is characterized in that a bore surface is formed by overlay welding a metal having high strength and/or I11 abrasion resistance on this surface.

[Effect]

By arranging the element blocks made of rolled steel plates so that the rolling direction of the rolled steel plates is almost perpendicular to the rolling load, the rolling load due to the anisotropic rolled steel plates is appropriately supported, making it easy to cluster. The housing for the mill can be made of a welded steel plate structure, which eliminates the defects peculiar to cast steel and guarantees excellent internal quality.2 The multiple element blocks are welded using multi-electrode electroslag welding. This facilitates welding of joints of relatively large cross-sectional areas of element blocks made of rolled steel plates.

The center block and two side blocks are joined by welding to form a mill block, which is machined to join the upper and lower mill blocks, and then both are welded together to form a mill block. Blocks are assembled and welded in an orderly manner, reducing the length of the manufacturing process for cluster mill housings. In addition, by welding the center block and two side blocks to form a mill block, for example, the center block is joined by welding two intermediate pieces at opposing positions on the side surface that provides the bore surface of the main block. The shape of the element block can be selected arbitrarily, such as configuring it as a mill block, so the machining allowance can be adjusted during the process of making it into a mill block.
The machining allowance for the mill block can be minimized, and since the mill block is machined, installation and setup on the processing machine are easy, and the housing for the raster mill can be manufactured economically.

A major factor determining the lifespan of a housing for a cluster mill is the corrosion resistance of the bore surface. By constructing the cluster mill housing with a mill block made of rolled steel plate, the rolled steel plate is a carbon AN plate, so welding workability is good, and the machined mill block has a high surface area on the bore surface. By welding a metal having strength and/or wear resistance, the wear resistance of the bore surface is improved, and the life of the cluster mill housing can be extended.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A housing for a cluster mill according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

1 and 2, a cluster mill housing 1 includes a pair of rolling rolls 17, a plurality of intermediate rolls 18 for reinforcing the deflection of the rolling rolls 17, and a plurality of intermediate rolls 18 for supporting the intermediate rolls 18. backup roll 19
(see Fig. 2, J3), and the portions where the backup rolls 19 come into contact with the cluster mill housing 1 via bearings (not shown) are called bore surfaces 13.

A cluster mill housing 1 includes an upper mill block 2 and a lower mill block 3 joined by a welded joint 16.
and two mill pieces 11 that fill the gap between the bore surfaces 13 formed by the upper and lower mill blocks 2°3. The upper mill block 2 consists of a central block 7 that provides a bore surface 13, and side blocks 5.6 that are joined to the central block 7 by welded joints 15 and reinforced from both sides. Block 8
and two intermediate pieces 9 joined by welded joints 14 at opposing positions on the surface of the main block 8 on the side of the bore surface 13.
．． It consists of 10. All of these element blocks are made of rolled steel plates, and the bore surface 13 is a surface obtained by machining the main block 8 and intermediate pieces 9 and 10 that constitute the central block 7. It is formed by applying

The lower mill block 3 is also constructed in substantially the same way as the upper mill block 2.

Next, the method of manufacturing the cluster mill housing 1 of this embodiment will be further explained with reference to FIGS. 3 to 5.

To manufacture the housing 1 for the cluster mill, first, a rolled steel plate is cut into a predetermined shape, and each element block, that is, the side blocks 5, 6, the main block 8, and the intermediate piece 9, 10
, a mill piece 11 is created.

At this time, the main block 8 and the side blocks 5,6 are arranged in the cluster mill housing 1, and as will be described later, the rolling direction of the rolled steel plate that constitutes them acts on these element blocks during rolling in the cluster mill. The orientation of the rolled steel plate is selected so that it is approximately perpendicular to the direction of the rolling load applied. Incidentally, since the side blocks 5 and 6 and the intermediate pieces 9 and 10 have the same or symmetrical shapes, the same block can be shared.

Next, as shown in FIG. 3, the bore surface 1 of the main block 8 is
Intermediate piece 9.1 in the opposite position of the side surface providing 3
0 and perform multi-electrode electroslag welding on the joint between the two to form a welded joint 14, thereby obtaining the central block 7.

Next, as shown in FIG. 4, the side blocks 5 and 6 are placed on both sides of the center block 7, and multi-electrode electroslag welding is performed on the joints between the two to form molten Mu joints 15. Let's call it block 4.

Next, by performing machining on the mill block 4 obtained in this way, the surface that becomes the basis of the bore surface 13 and the shape necessary for the underground mill block 2 are formed, and the upper part shown in FIG. A semi-finished product of a mill block 2 without overlay welding 12 is obtained. Similarly, another mill block 4 is subjected to R machining to form a surface that is the basis of the bore surface 13 and a shape necessary for the underground mill block 3, thereby obtaining a semi-finished product of the lower mill block 3. As shown in FIG. 5, these semi-finished products of the upper and lower mill blocks 2.3 have a metal layer formed by welding a high-strength and/or wear-resistant metal onto the base surface of the bore surface 13. 12 and bore surface 1
Get 3.

Next, the upper and lower mill blocks 2.3 thus obtained are stacked one on top of the other as shown in FIG. By forming, the two are integrated. Thereafter, the mill pieces 11 are assembled and welded, and the bore surface 13 provided by the metal layer 12 is finished polished to obtain the cluster mill housing 1 of this embodiment.

Next, the above manufacturing method will be explained in more detail, including its effects.

Conventional housings for cluster mills are made of N-steel, but due to the complex shape of the housing, the riser effect, which is carried out to ensure quality, does not work on the details and does not pull on the bore surface etc. Defects specific to MJ steel, such as cavities, are likely to occur,
Furthermore, in order to improve this defect, the cluster mill housing l of the sixth embodiment, in which defects are likely to occur inside the cast steel,
Compared to cast steel, internal defects are eliminated by rolling, and the structure is welded using rolled steel sheets, which have superior internal quality.

By the way, in the case of a steel plate structure, unless the block division of the rolled steel plates constituting the structure is made simple, it will be a problem in terms of economy. On the other hand, rolled steel plates have anisotropy in strength, and exhibit particularly high strength against loads in a direction perpendicular to the rolling direction. Therefore, as shown in FIG. 6, the housing 1 for the cluster mill is designed to accommodate rolling loads during rolling. ! (Rolling reaction force) 20 is received from the backup roll 19 through the bore surface 13, and each Divide the element blocks and select the orientation of the rolled steel plate when creating each element block.

Specifically, the rolling load (rolling reaction force) 20 is applied to the bore surface 13 in a direction passing through the axial center of the intermediate roll 18 and the axial center of the backup roll 19, as shown in FIG. It is effective to divide the block into blocks so that the direction of the rolling load (rolling reaction force) 20 and the rolling direction of the rolled steel plate are perpendicular to each other in this state. Therefore, as shown in Figure 7,
With respect to the cluster mill housing 1, the vertical direction is the Y axis and the horizontal direction is the X axis, and all directions of the rolling load (rolling reaction force) 20 are divided into two axial directions of X-Y, and the same rolling FT is heavily rolled. In the rolling reaction force (reaction force) 20, the direction of the larger component of the rolling reaction force Y-axis component force 21 and the rolling reaction force X-axis component force 22 is defined as the direction of the rolling load (rolling reaction force) 20 at that position. As a result, the rolling load (rolling reaction force) 20 acting on the cluster mill housing 1 is simplified as shown in FIG. The part in which the rolling direction of the rolled steel plate is perpendicular to the direction of 2OA, that is, the center block 7, and the part in which the rolling direction of the rolled steel plate is perpendicular to the direction of 120B20C, that is, the side surface of the rolling load represented by the rolling reaction force X-axis component force. Block 5.6
It is broadly divided into

The center block 7 is further divided into a main block 8 and an intermediate piece 9°10 for reasons described later, so that the rolling direction of the main block 7 is the same as the rolling load f.
112 perpendicular to the direction of the OA. Also, the direction perpendicular to the rolling load 20A is the direction perpendicular to the paper surface of Figure 7,
Since there are two horizontal directions, left and right on the paper of FIG. 7, in this embodiment, the former direction perpendicular to the paper of FIG. and the rolling cross direction are both perpendicular to the rolling load IE2 OA! ,It is configured.

Similarly, in the side block 5.6, both the rolling pass direction and the rolling cross direction of the rolled steel plate constituting the side block 5.6 are subject to the rolling load f! 2
They are arranged and configured to be perpendicular to 0B and 20C, respectively.

In addition, in the cluster mill housing 1, the axes of the backup rolls 19 are arranged on the same circumference, and the bore surface 13 is also arranged so as to follow this, so the center block 7 is made of a single rolled steel plate. If this configuration is adopted, extra machining costs will increase, resulting in poor economic efficiency. Therefore, the central block 7 is divided into the main block 8 and the two intermediate pieces 8.1.
0 and forming the bore surface 13 thereon, the machining allowance can be minimized.

In the cluster mill housing 1 of this embodiment, not only the central block 7 providing the bore surface 13 but also the side blocks 5.6 are made of rolled steel plates. This is the result of considering maintenance of internal quality and weldability. In other words, in rolled steel sheets, cavities and the like are compressed by rolling, making it possible to obtain a relatively uniform structure.
Normally, the strength of cast steel is controlled by controlling the amount of carbon to increase its strength, but as the amount of carbon increases, there is a problem that weldability deteriorates. In rolled steel sheets, the crystal grains are small and the crystal growth direction is the same, and the rolling effect makes it possible to increase the strength without increasing the carbon content. By using rolled steel plates for the curved blocks except for the central block 7, it is possible to divide the cluster mill housing 1 and ensure stable internal quality.

Regarding the lifespan of the cluster mill housing 1, the wear resistance of the bore surface 13 is an important factor.

The wear resistance of the bore surface 13 has been improved by controlling the chemical composition of the cast steel in conventional g-steel products, but the increase in additive components makes it less economical. -For surface 13, this is formed by overlaying a high-strength and/or wear-resistant metal layer 2.

Since the material of the overlay weld metal can be freely selected according to the specifications and application for the bore surface 13, it is easy to provide the high strength and/or wear-resistant metal layer 12 with the necessary properties. .

When the cluster mill housing 1 has a steel plate structure as described above, the problem arises as to how to join each element block.

That is, in the housing 1 for a cluster mill, since the joint area of each element block is large, the economical efficiency of the ordinary welding method is poor.

Therefore, by performing welding by multi-electrode electroslag welding, which is a highly efficient large cross-sectional area welding method, it becomes more economical.In addition, in terms of the quality of the weld, multi-electrode electroslag welding produces a uniform structure. Furthermore, defects can be easily prevented by controlling the welding conditions even when defects occur.

In the manufacturing method of the cluster mill housing 1, in the case of conventional cast steel, a mold of the same shape must be made and a sand mold must be made, so the more complex the shape, the longer the manufacturing process. Become. Furthermore, after the casting is completed and the entire body is solidified, rough machining is performed, but at this time, defects such as cavities, which occur during solidification of the cast steel, are detected on the surface and the base machining surface. Repair welding will be required.

According to this embodiment, a rolled steel plate is cut into element blocks,
Since each element block is assembled and welded in an orderly manner, the length of the manufacturing process is shortened. Furthermore, since the electroslag welding method, which is easy to control, is used, the defect occurrence rate is low and no repair work is required.

In addition, in terms of economy, the material cost of conventional cast steel is relatively high; however, in this embodiment, low-carbon rolled steel plate, which is inexpensive, is used as the material. & By performing weekly board cutting and improving yield, material costs can be reduced.

Furthermore, in terms of economic efficiency, processing costs are a problem for welding and machining, but for welding, highly efficient
By using the ffi electroslag welding method, welding can be performed at low processing costs.1 Regarding machining, since it is a welded structure, the central block 7 is further welded to the main block 8 and the intermediate pieces 9, 10 as described above. It is easy to adjust the machining allowance, such as by dividing it into two parts, and by selecting the optimal shape before machining, it is possible to perform machining at low machining costs. Furthermore, machining costs include
Processing 11 in addition to machining fee! This includes ease of installation on the machine (separation) and machining, but in this example, the mill block 4 which is a living body shape of the housing 1 for a cluster mill is included.
Since machining is carried out in this condition, installation and machining are easy, and the cost of machining is also low in this respect.

As described above, the cluster mill housing 1 of this embodiment can be optimally designed in consideration of economic efficiency, and can also improve economic efficiency in manufacturing.

Therefore, according to this embodiment, it is possible to provide a housing 1 for a raster mill that has superior internal quality, has a longer life, and is less expensive than the conventional IA product.

〔Effect of the invention〕

According to the present invention, since the housing for the cluster mill is made of steel plate welded and refined, defects peculiar to cast steel do not occur, and excellent internal quality can be guaranteed.

Since multiple element blocks were welded by multi-electrode electroslag welding, element blocks with large joint cross-sectional areas can be welded stably and with high quality.

In addition, since the bore surface is overlaid with a metal having high strength and/or wear resistance, the IIT abrasion resistance of the bore surface is improved, and the life of the cluster mill housing can be extended.

Furthermore, since each element block is properly divided and assembled and welded in an orderly manner, the manufacturing process length of the cluster mill housing is shortened, and the center block and two side blocks are welded to form a mill block. Mill Block's [i! Processing costs can be minimized, installation on processing machines and setup are easy, and economical manufacturing is possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the entire housing for a cluster mill according to an embodiment of the present invention, and FIG. 2 is a front view of the housing for the cluster mill, showing how the rolling load (rolling reaction force) during rolling can be controlled. Fig. 3 is a perspective view of the central block made in one step of the manufacturing method for housings for cluster mills, and Fig. 4 is a perspective view of the central block made in a later step of the same manufacturing method. FIG. 5 is a perspective view of the mill block before machining allowance adjustment; FIG.
Fig. 6 is an explanatory diagram showing the component force of rolling load (pressure reaction force), and Fig. 7U:jJ shows the relationship between the simplified direction of rolling load applied to the bore surface and the division of the cluster mill housing. It is an explanatory diagram. Explanation of symbols 1... Cluster mill housing 2... Upper mill block 3... Lower mill block 4... Mill block 5.6... Side block 7... Center block 8... Main Block 9.10... Intermediate piece 12... Metal layer for overlay welding 13... Bore surface

Claims (7)

[Claims] (1) A housing for a cluster mill having a shape in which a pair of rolling rolls and a plurality of backup rolls are incorporated, the shape including a bore surface for supporting each of the back rolls via a bearing, wherein the bore It has upper and lower mill blocks each having an inner surface that is a surface, and each of the upper and lower mill blocks is divided into a plurality of element blocks made of rolled steel plate, and at least one of the plurality of element blocks is Some of these are arranged so that the rolling direction of the rolled steel plates constituting them is approximately perpendicular to the direction of the rolling load that acts on these element blocks during rolling, and the plurality of element blocks are joined by welding. Housing for cluster mills. (2) A housing for a cluster mill according to claim 1, wherein the plurality of element blocks are welded by multi-electrode electroslag welding. (3) A housing for a cluster mill having a shape in which a pair of rolling rolls and a plurality of backup rolls are incorporated, and the shape includes a bore surface for supporting each of the back rolls via a bearing, a rolled steel plate. The bore surface is obtained by machining a rolled steel plate constituting the mill block, and is overlaid with a metal having high strength and/or wear resistance. A housing for a cluster mill characterized by being constructed by welding. (4) In a method for manufacturing a housing for a cluster mill, the housing has a shape in which a pair of rolling rolls and a plurality of backup rolls are incorporated, and the shape includes a bore surface for supporting each of the back rolls via a bearing. A mill block is prepared by preparing a central block made of rolled steel plate placed at a portion that provides the bore surface and two side blocks made of rolled steel plate placed on both sides of the central block, and joining these by welding to form a mill block. The two mill blocks are prepared and each is machined to form a surface that becomes the bore surface, and the two mill blocks are formed into upper and lower mill blocks, respectively. A method for manufacturing a housing for a cluster mill, characterized by joining blocks by welding to form an integral structure. (5) The method for manufacturing a housing for a cluster mill according to claim 4, wherein the central block is a main block;
Manufacture of a housing for a cluster mill, characterized in that it is constructed by preparing two intermediate pieces arranged at opposite positions on the side of the main block that provides the bore surface, and joining these together by welding. Method. (6) In the method for manufacturing a housing for a cluster mill according to claim 4, the center block and the side blocks include:
The rolling direction of the rolled steel plates constituting the main part of the central block and the rolling direction of the rolled steel plates constituting the side blocks are respectively arranged almost perpendicular to the direction of the rolling load acting on these element blocks during rolling. A method for manufacturing a housing for a cluster mill, characterized by: (7) In the method for manufacturing a housing for a cluster mill according to claim 4, after machining the rolled steel plate material constituting the two mill blocks to form a surface that becomes the basis of the bore surface, the surface is A method for manufacturing a housing for a cluster mill, characterized in that the bore surface is formed by overlay welding a metal having high strength and/or wear resistance.