JPS6219487B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an impeller for a continuous steel plate quenching apparatus that continuously quenches a steel plate by passing the steel plate into a cooling tank.

In order to increase the cooling rate of the steel plate and perform quenching work efficiently, it is necessary to increase the relative speed between the surface of the steel plate and the cooling water. For this reason, conventionally, a cooling means has been employed in which pressurized cooling water is injected from a nozzle and collides with the surface of the steel plate.

However, when using this cooling means, the equipment for pressurizing the cooling water becomes large and the amount of cooling water used becomes enormous, resulting in the disadvantage that the quenching equipment is expensive and the operating cost increases. Furthermore, as the water supply piping becomes thicker, the space occupied by the piping increases, which not only necessitates an increase in the height and length of the quenching equipment, but also increases the weight of the piping and its interior, requiring reinforcement of the frame, etc. There is. In addition to this, the pitch of the parallel piping becomes large, making it difficult to increase the jet water flow density, and the cooling capacity must be reduced. Further, clogging of the cooling water nozzle causes uneven quenching, which has the drawback of increasing the time and cost required to repair the clogging.

On the other hand, the present inventors previously proposed ``a water storage tank through which a steel plate passes to be cooled, and a cooling water tank provided in this water storage tank to move cooling water in the direction of movement of the steel plate or in the opposite direction to the direction of movement of the steel plate. He invented a continuous hardening device for steel plates with an impeller and put it into practical use.

As shown in FIGS. 1 to 3, this steel plate continuous quenching apparatus includes rollers 1 for holding a steel plate 12 from above and below in a water storage tank 10 and transporting it in the direction of arrow C.
6, 18, and the rollers 16, 18
are configured to be rotated in the directions of arrows A and B by drive devices 28 and 30, and cooling water 42 supplied from main water supply pipes 64 and 66 is provided in the water storage tank 10.
is filled with. Further, the rollers 16,1
Between 8 and 8 are impellers 32 and 3 having blade plates 40.
4 is provided, and the impellers 32, 34 are driven by a drive device 5.
2 and 54 to rotate in the directions of arrows D and E, thereby stirring the cooling water 42. Note that reference numerals 56 and 58 are impeller boxes for efficiently stirring.

Here, the blade plates 40 of the impellers 32 and 34 extend from the outer peripheries of the rotation shafts 36 and 38 of the impellers in a radial direction along a virtual plane including the axes of the rotation shafts at regular intervals. Therefore, by rotating the impellers 32 and 34, the cooling water around the impellers is stirred, and in particular, the cooling water on the surface of the steel plate 12 is moved, for example, in the opposite direction to the moving direction of the steel plate 12, and the cooling water is moved to a predetermined level. Efficiently cools steel plates given relative speed. According to such a structure of the impellers 32 and 34, the flow of cooling water does not occur at all in the direction perpendicular to the moving direction of the steel plate 12, that is, in the width direction of the steel plate, and therefore the quenching in the width direction of the steel plate is prevented. This is extremely advantageous in preventing non-uniformity.

However, according to experiments conducted by the inventors, when the impellers 32 and 34 having the above structure are used, the cooling water around the radial tips of the blade plates 40 is effectively mixed and replaced with newly supplied cooling water. However, it is difficult to mix the cooling water around the root of the blade plate 40, that is, the joint between the blade plate and the rotating shafts 36 and 38, with the newly supplied cooling water, and the high temperature cooling water is always used. The rotating shafts 36, 38 in the retained state
It was confirmed that it was being rotated as the . Furthermore, the supplied cooling water contains air bubbles,
Once the air bubbles have entered the vicinity of the joint of the vane plate 40 to the outer periphery of the rotating shaft, the cooling water containing the air bubbles will accumulate around the joint of the vane plate 40, causing the air bubbles and the water storage tank 10 to stagnate. It becomes difficult to discharge to the outside. When such a phenomenon occurs, the temperature of the cooling water increases, and the cooling capacity decreases significantly.
In addition, there is a risk that air bubbles remaining around the joints of the vane plates 40 may reduce the efficiency of cooling water usage, increase the rotational resistance of the impeller and thus increase the rotational driving force, and further increase corrosion of the impeller. There is.

The present invention was made in view of these problems, and its purpose is to cool the steel plate in the rotational direction of the impeller by rotation of the impeller within a range that does not cause non-uniform hardening in the width direction of the steel plate. Not only does it move water, but it also moves cooling water in the width direction of the steel plate.
This prevents cooling water and air bubbles from accumulating around the rotational shaft of the impeller, that is, around the joint of the vane plate to the rotational shaft.

In order to achieve this object, the present invention provides vane plates arranged along the longitudinal direction of the rotation shaft of the impeller at approximately equal intervals around the outer periphery of the rotation shaft of the impeller. It is attached to the outer periphery of the rotating shaft along a virtual plane that intersects at an angle of 10 degrees or less when viewed in a direction perpendicular to the axis, thereby allowing cooling water to flow also in the axial direction of the vane. It is designed to create a flow of

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

4 to 6 show an enlarged view of an embodiment of the impeller according to the present invention. Here, on the outer periphery of the rotating shaft 136 of the impeller 132, a plurality of blade plates 140, for example, four blade plates 140, are arranged at approximately equal intervals when viewed in the radial direction of the rotating shaft along the longitudinal direction of the rotating shaft. There is. The blade plate 140 is attached to the rotating shaft 136 so that the torsional angle α, more specifically, the torsional angle α is 30 degrees or less when viewed in a direction perpendicular to the axis of the rotating shaft 136 with respect to a virtual plane containing the axis of the rotating shaft 136. It is attached in a spiral shape. Therefore, as shown in FIG. 6 in particular, the cross section perpendicular to the axis of the rotating shaft 136 of the impeller 132 is such that the center line l of each blade plate 140 always intersects with the axis of the rotating shaft 136. It's summery. In this way, when the spiral blade plate 140 is used, the twist angle α is 2.
If the helix angle α exceeds 15 degrees, the cooling water moves significantly in the longitudinal direction of the impeller, that is, in the width direction of the steel plate, causing quenching distortion in the width direction of the steel plate. Therefore, this twist angle α is preferably in the range of 2 degrees to 15 degrees.

Further, as another embodiment, when the twist angle α is 10 degrees or less, the blade plate does not need to have a spiral curved surface, and for example, as shown in FIG. 7, a flat blade plate 240 may be used. It may be provided along a virtual plane that intersects a virtual plane including the axis of the rotating shaft 136 at an angle of 10 degrees or less when viewed in a direction perpendicular to the axis. In this case, the cross section perpendicular to the axis of the rotating shaft 136 is as shown in FIG. 6 at the longitudinal center of the impeller 132, but at other locations, as shown in FIG. The center line l' does not intersect with the axis of the rotating shaft 136. However, since the angle at which the blade plates 140 intersect is less than 10 degrees,
This will not cause any disturbance to the cooling water.

In the continuous steel plate hardening apparatus using the impellers 140 and 240 configured in this way, the impeller 1
By the rotation of 32, the cooling water is moved at a predetermined relative speed in the transfer direction of the steel plate or in the opposite direction to the transfer direction, and also moves slowly in the width direction of the steel plate within a range that does not cause non-uniform hardening. . As a result, the cooling water around the joint of the blade plates 140, 240 to the outer periphery of the rotating shaft 136 and the air bubbles mixed in the cooling water do not stay there, but flow out in the axial direction of the impeller, and the water storage tank is discharged and circulated to the outside.

As explained above, according to the present invention, the cooling water around the rotating shaft of the impeller and the air bubbles in the cooling water flow out without causing uneven quenching in the width direction of the steel plate, and are combined with newly supplied cooling water. This has the excellent effect of preventing harmful effects caused by cooling water and air bubbles remaining around the impeller rotation shaft, such as a decrease in cooling efficiency and an increase in rotational resistance to the impeller.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional continuous steel sheet hardening apparatus equipped with an impeller, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a sectional view taken along the - line in Fig. 1. FIG. 4 is an enlarged front view showing one embodiment of the impeller of the continuous steel sheet hardening apparatus according to the present invention, FIG. 5 is a side view of the same, and FIG. 7 is a sectional view taken along the same position as FIG. 6 showing another embodiment of the present invention. 10... Water tank, 12... Steel plate, 32, 34, 13
2... Impeller, 36, 38, 136... Rotating shaft, 4
0,140,240... Vane plate, α... Torsion angle.

Claims (1)

[Scope of Claims] 1. A steel plate in which a steel plate is passed through a water storage tank, an impeller is provided in the water tank, and the rotation of the impeller moves cooling water on the surface of the steel plate at a constant relative speed to the steel plate. In the continuous quenching device, the impeller has a plurality of blade plates arranged at approximately equal intervals on the outer periphery of the impeller rotation shaft along the longitudinal direction of the impeller rotation shaft. An impeller of a continuous steel sheet hardening apparatus that is attached to the outer periphery of the impeller rotating shaft along a virtual plane that intersects at an angle of 30 degrees or less when viewed in a direction perpendicular to the axis. 2 The vane plate has an angle of 2 degrees to a virtual plane including the axis of the impeller rotating shaft when viewed in a direction perpendicular to the axis.
Claim 1: The impeller is attached to the outer periphery of the impeller rotation shaft in a spiral shape having a helix angle of 15 degrees.
The impeller of the steel plate continuous quenching equipment described in 2. 3. The vane plate is along a virtual plane that intersects an imaginary plane including the axis of the impeller rotating shaft at an angle of 10 degrees or less when viewed in a direction perpendicular to the axis. The impeller of the steel plate continuous quenching equipment described in 2.