CN101015838B - Large-scale heavy and medium plate mill roll-gap-regulation non-uniform sickness screw-tooth pressure down screw-pairs - Google Patents

Abstract

The invention relates to the field of metallurgical machinery, in particular to a large-scale medium and heavy plate mill roll gap adjustment screw thread pair for pressing down unequal-thickness threads. It is characterized in that: the thread pitch and tooth side clearance of the screw thread pair of unequal-thickness screw tooth pressing and equal-thickness screw tooth pressing are unchanged, and the thickness of the screw thread of the pressing nut (2) is greater than that of the pressing screw (1 ) thread thickness, the thickness of the pressed nut (2) thread is equal to the thickness of the original equal-thickness thread plus the thread thickness difference δ, and the thickness of the pressed screw (1) thread is equal to the original equal-thickness thread thickness minus the thread Thickness difference δ, thread thickness difference δ = 2.5 ~ 3.5mm. An arc groove is opened at the bottom of the screw teeth of the depressed screw (1), the arc groove is tangent to the contour lines of two adjacent screw teeth, and the arc radius R=8-12mm. The roll gap adjustment of the large medium and heavy plate rolling mill has a reasonable design and reliable operation of the thread pair for pressing the unequal-thickness thread, and its service life can be increased by more than 3 years compared with the thread pair for pressing the thread with the equal-thickness thread.

Description

Roll Gap Adjustment of Large Medium and Heavy Plate Mill

technical field

The invention relates to the field of metallurgical machinery, in particular to an auxiliary device for adjusting the roll gap and pressing down the thread of a large medium and thick plate rolling mill.

Background technique

There are about 29 sets of medium and heavy plate rolling mills and steckel rolling mills specializing in the production of medium and heavy plates in my country, with a total production capacity of about 20 million tons. In 2005, with the commissioning of Baosteel's 5000mm rolling mill and the commissioning of a batch of reformed and newly built equipment, the output will increase to a certain extent. Among them, the typical ones are the 3500mm plate rolling mill of Jinan Iron and Steel Co., Ltd. and the 3500mm medium plate rolling mill of Shougang Iron and Steel Co., Ltd.

The roll gap adjustment and pressing screw pair of large medium and heavy plate mills is the core component of the electric pressing device of the rolling mill. Its life and reliability are related to the stable production of the whole rolling mill. However, in the actual use process, the depressing thread pair wears seriously, the life is short, and the downtime replacement time is increased, which seriously affects the production process and brings huge economic losses.

The 2800mm medium plate rolling mill of a medium plate factory had a serious problem of wear and tear on the screw and nut on both sides of the rolling mill at the initial stage of production. When the thread pair was started to adjust the roll gap, copper scraps were discharged from the screw nut, and the working current of the screw motor was constant. exceed the design normal value. After shutting down, disassemble and press down the screws and nuts for inspection and found that the copper alloy nuts are severely worn. A ring-shaped partial groove has appeared on the zigzag tooth shape, and the root wear is more serious, while Copper shavings and burn marks are bonded to the partial surface of the steel pressing screw profile. The convex spherical pair of the thrust bearing is severely damaged, and the edge of the rolling body of the bearing is partially fractured or peeled off. According to on-site investigation, the annual wear of the threaded auxiliary nut of a 3500mm medium and heavy plate rolling mill in a medium plate factory exceeds 1mm.

Contents of the invention

螺母寿命低等问题，本发明提供一种大型中厚板轧机辊缝调节不等厚螺牙压下螺纹副，这种不等厚螺牙压下螺纹副设计合理、工作可靠，与等厚螺牙压下螺纹副相比其使用寿命可提高3年以上。In order to solve the existing medium and heavy plate rolling mill to press down the thread auxiliary copper

In order to solve the problem of low nut life, the present invention provides a large-scale medium and heavy plate rolling mill roll gap adjustment unequal-thickness thread pressing thread pair, this unequal-thickness thread pressing thread pair is reasonable in design and reliable in operation The service life of the screw thread pair under the tooth pressure can be increased by more than 3 years.

The technical solution adopted by the present invention to solve the technical problem is: the roll gap adjustment of the large-scale medium and heavy plate rolling mills does not change the thread pitch and the tooth side clearance of the screw thread pair of the unequal-thickness thread pressing and the equal-thickness thread pressing thread pair, The thickness of the thread of the pressed nut is greater than the thickness of the thread of the pressed screw. The thickness of the thread of the pressed nut is equal to the thickness of the thread of the original equal thickness plus the thread thickness difference δ. The thickness of the screw thread is equal to the thickness of the original equal-thickness thread minus the thread thickness difference δ, and the thread thickness difference δ=2.5-3.5mm. Open an arc groove at the bottom of the screw thread valley of the pressed screw, the arc groove is tangent to the contour lines of two adjacent thread teeth, and the arc radius R=8～12mm.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the thread pair for adjusting and pressing the roll gap of a large medium and heavy plate rolling mill;

Fig. 2 is a partial enlarged view of the thread pair of the large-scale medium and heavy plate rolling mill for roll gap adjustment and equal thickness thread pressing;

Figure 3 is the effect of the stiffness of the thread pair material on the pressure distribution of the thread contact surface;

Fig. 4 is a partial enlarged view of the screw thread pair of the large medium and heavy plate rolling mill for adjusting the roll gap of unequal thickness;

Figure 5 is a pressure distribution diagram of the second layer of thread contact surface;

Fig. 6 is a pressure distribution diagram of the contact surface of the thread on the eighth layer;

Fig. 7 is a pressure distribution diagram of the thread contact surface of the 21st layer.

In Figure 1, 1. Press down the screw, 2. Press down the nut.

Detailed ways

Example

Fig. 1 is a schematic diagram of the structure of a large-scale plate rolling mill for pressing down threads, part 1 is a pressing screw, part 2 is a nut, and the thread of the thread adopts a wolf tooth shape (see Fig. 2). The pressing screw is made of steel, and the nut is made of copper. The modulus of elasticity of the two differs by a factor of two. Under the action of rolling force, the thread of the high-rigidity screw 1 undergoes a nearly rigid displacement, and the thread of the nut 2 with low rigidity undergoes elastic bending deformation similar to a cantilever beam. The deformation of the contact area of the nut thread 2 is extremely uneven, the elastic flattening deformation at the root of the thread is large, and the bending deformation at the top of the thread is large. As a result, the peak contact pressure of the thread of the nut 2 tends to be at the thread root, but the pressure at the top of the thread is extremely small or even out of contact (see Figure 3 for the copper nut thread pair pressure distribution curve).

The materials of screw 1 and nut 2 are respectively steel and copper or The thread surface pressure distribution obtained when steel and steel are matched (see Figure 3), the crossed line is steel and copper materials, and the dotted line corresponds to steel and steel materials. The two simulations were performed under the same conditions except for the nut material. Obviously, when the elastic modulus of the screw and the nut are the same, the contact pressure distribution is basically symmetrical, and the peak value is in the middle; when the difference between the elastic modulus of the screw and the nut material is greater, the contact pressure distribution is slope-shaped, and the peak value is At the root of the nut that favors soft materials.

Roll gap adjustment of large medium and heavy plate rolling mills. Pitch P=40mm (see Figure 4) of screw thread pair with unequal thickness. In order to meet the sliding function conditions, the manufacturing materials of screw and nut are steel and copper respectively. The thread of the thread adopts a wolf tooth shape, and the pitch and backlash of the teeth remain the same as that of the equal-thickness thread pressing thread pair, and the thread thickness difference of the pressing screw is δ=3mm. The thread thickness of unequal-thick thread sub-nut 2 is equal to the original equal-thickness thread thickness plus the thread thickness difference δ, and the unequal-thickness thread is pressed down. Thread thickness minus thread thickness difference δ. Open an arc groove at the valley bottom of thread pair pressing screw 1 with unequal thickness threads, the arc groove is tangent to the contour lines of two adjacent threads, and the radius of the arc is R=10mm. The thickness of the original equal-thickness thread is 10mm, and the thread pair is pressed down by the unequal-thickness thread. The thickness of the screw 1 thread is thinned: b1=10mm-3mm=7mm, and the thickness of the unequal-thickness thread is pressed by the threaded auxiliary nut 2. Increase: b2=10mm+3mm=13mm.

A circular arc groove tangent to the contour lines of two adjacent screw teeth is formed at the valley of the screw teeth of the pressing screw 1 to ensure the same stiffness conditions as the bending of the nut screw teeth. Figure 5, Figure 6, and Figure 7 show the comparative pressure distribution diagrams of the 2nd, 8th, and 21st-layer threads from bottom to top for nuts with 22 layers of threads and unequal-thickness threads.

The working life of the thread pair under the reduction of the unequal thickness thread is adjusted by the roll gap adjustment of the large medium and heavy plate rolling mill with a pitch of 40mm and the thread thickness difference of 3mm, and the working life of the thread pair under the equal thickness reduction is increased by more than 3 years.

Claims (1)

1. one kind large-scale heavy and medium plate mill roll-gap-regulation non-uniform sickness screw-tooth pressure down screw-pairs, comprise (2) two parts of housing screw (1) and screw box, it is characterized in that: large-scale heavy and medium plate mill roll-gap-regulation non-uniform sickness screw-tooth pressure down screw-pairs is compared constant with the pitch that the uniform thickness thread is depressed screw thread pair with backlash, the thickness of its screw box (2) thread is greater than the thickness of housing screw (1) thread, the thickness of screw box (2) thread equals former uniform thickness thread thickness and adds the thick poor δ of thread, the thickness of housing screw (1) thread equals former uniform thickness thread thickness and subtracts the thick poor δ of thread, the thick poor δ of thread=2.5～3.5mm; The material of described housing screw (1) and screw box (2) is respectively steel and copper material; The place opens arc groove in housing screw (1) thread the lowest point, and the outline line of arc groove and two adjacent threads is tangent, arc radius R=8～12mm.

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