JPH0415364Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a rolling mill that is characterized by the shape of a key that fixes a screw nut or hydraulic cylinder for rolling down a rolling roll to a housing of a rolling mill that rolls metal sheets. It is something.

<Prior Art> Conventionally, as shown in FIGS. 4 and 5, a housing 2 is provided with a storage hole 2b in the upper and lower surfaces of the housing 2 in a direction perpendicular to the traveling direction of the rolled material 10. Two key grooves 2a are provided in each. 6 is a back-up roll, 7 is a work roll, and 8 and 9 are a pair of bearing boxes that pivotally support both ends of these rolls 6 and 7, which are respectively fitted into the housing 2 so as to be movable up and down. 3 is inserted into the storage hole 2b with a nut, has a keyway 3a continuous with the keyway 2a of the housing 2, and is fixed to the housing 2 with a key 11.

4 is a reduction screw that passes through the upper part of the housing 2 and is screwed into the nut 3, and is rotated by an upper driving device (not shown) to lower the back-up roll 6 and the work roll 7 through the upper bearing box 8. do.

As shown in FIG. 6, the corner portion 11 of the key 11
In a, the key 1 is attached to the corner rounded part 2c of the keyway 2a.
In order to prevent the two surfaces from coming into contact with each other, a straight surface is provided along the entire length in the longitudinal direction at an angle of approximately 45 degrees in cross-sectional shape. Although not shown in the drawings, a hydraulic type lowering device is also used in addition to the screw type lowering device as described above.

<Problems to be solved by the invention> However, according to a three-dimensional analysis of the structural deformation of the housing 2 when a rolling reaction force is applied during rolling of the rolled material 10, the lower part of the storage hole 2b is caused by the rolling reaction force of the housing 2. Due to the upward deflection of the upper part, the keyway 2a is deformed into an oval shape as shown by the two-dot chain line in FIG.
The peripheral edge (inner end) side of b is particularly significantly deformed.

Furthermore, the keyway 2 of the housing 2 shown in FIG.
Due to the space between a and the key 11, the force that is no longer transmitted to the key 11 bypasses the corner radius portion 2c, causing stress concentration in the corner radius portion 2c. Therefore, when analyzed using the three-dimensional finite element method, the corner radius portion 2c of the keyway 2a is exposed to higher stress than expected, as shown in Figure 8, and in some cases, cracks may occur. The problem is that it can cause unexpected trouble.

The present invention has been developed in view of the current situation, and it is an object of the present invention to provide a rolling mill that can significantly reduce the maximum stress generated at the corner radius of the keyway.

<Means for Solving the Problems> In order to achieve the above object, the present invention has a structure in which, in a key for fixing a rolling roll reduction device to a storage hole of a rolling mill housing, the key is fitted into the rolling mill housing. It is characterized by having a contact surface that connects not only to the flat part of the keyway but also to both corner rounded parts of the keyway.

<Function> With the above configuration, the corner part of the key is joined to the corner round part of the keyway, and the height of the space between the housing and the key is reduced.
Stress concentration can be reduced.

<Embodiment> An embodiment of the present invention will be described below with reference to FIG. 1, which is a partial cross-sectional view of the upper part of the housing as viewed from the bottom side thereof, and FIG. 2, which is a partially enlarged side view taken from the line - in FIG. This will be explained based on FIG. 3, which is a principle diagram showing the shape and stress distribution of the corner portion of the key.

In FIGS. 1 to 3, the same members as those in the conventional device are denoted by the same reference numerals, and redundant explanation will be omitted.

As shown in Figure 1, 1 is a key and housing 2
A keyway 2a is provided continuously between the lower surface of the upper part and the lower surface of the nut 3 inserted into the storage hole 2b.
3a, and fixes the nut 3 to the housing 2.

As shown in FIG. 2, the corner portion 1a of the key 1 is provided with a curved surface in its cross-sectional shape over the entire length in the longitudinal direction, and partially contacts the corner radius portion 2c of the keyway 2a. A height h of the space at the joint between the keyway 2a and the key 1 is formed.
When a back-up roll and a work roll (not shown) are rolled down by a rolling screw 4 and a material to be rolled (not shown) is passed through and rolled, a rolling screw 4 and a nut 3 are attached to the cross beam section of the upper part of the housing 2. The rolling reaction force acts on the housing hole 2b, thereby bending upward and deforming the storage hole 2b into an oval shape, so that the keyway 2a also tends to narrow in width, especially on the peripheral edge side of the storage hole 2b, and the key groove 2a is bent on both sides of the key 1. However, the corner portion 1a of the key 1 contacts the lower part of the corner rounded portion 2c of the keyway 2a, reducing the height h of the space at the joint between the keyway 2a and the key 1.
As a result, the load bearing rate of the key 1 is increased compared to the conventional shape, and the corner radius portion 2c of the keyway 2a is increased.
Since the flow of force detouring around the corner portion 2c is reduced and the stress concentration rate is reduced, the stress generated in the corner radius portion 2c is also reduced.

These were calculated using the three-dimensional finite element method and verified using an actual machine.

In this embodiment, the maximum stress generated in the corner radius portion 2c of the keyway 2a can be reduced to 65% of that of the conventional device, which is 100%.

Note that the key of the present invention is used not only for the above-mentioned embodiments but also for fixing the hydraulic pressure reduction cylinder to the housing.

<Effects of the invention> As described above, according to the invention, the key for fixing the screw nut of the reduction device or the hydraulic cylinder to the housing hole of the housing is also joined to the corner radius of the keyway. The maximum stress generated at the corner radius of the keyway can be significantly reduced, making it possible to rationally design the housing.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of the upper part of the housing of a rolling mill, which is an embodiment of the present invention, seen from the bottom side, Fig. 2 is a partially enlarged side view taken from the - line in Fig. 1, and Fig. 3 is A principle diagram showing the shape and stress distribution of the corner part of the key according to the present invention, FIG. 4 is a side view showing an example of a conventional device, and FIG.
6 is an enlarged partial side view of the main part of FIG. 4, FIG. 7 is a principle diagram showing the deformation of the housing hole and keyway, and FIG. 8 is a corner part of a conventional key. FIG. 2 is a principle diagram showing the shape and stress distribution of FIG. Further, in the figures, 1 is a key, 1a is a corner part, 2 is a housing, 2a is a keyway, 2b is a storage hole, 2c is a corner radius part, 3 is a nut, and 4 is a screwdriver.

Claims (1)

[Scope of utility model registration request] In a key for fixing a rolling roll lowering device to a storage hole of a rolling mill housing, a contact that joins not only the flat part of the key groove of the rolling mill housing into which the key is fitted but also both corner rounded parts of the key groove. A rolling mill characterized by having a surface.