JPH04286522A - Method for preventing overturn of h-shape steel in skid carrying - Google Patents

Abstract

PURPOSE:To obtain a method for carrying H-shape steel at high speed without overturning at the time of sliding for carrying H-type steel, which is placed on a skid at I-position, with a transfer with claw. CONSTITUTION:A skid 1 is divided into three blocks of an empty block L, an initial carrying block L, a latter carrying block L in the carrying direction. Carrying speed V in the initial carrying block L and acceleration in the latter carrying block L are obtained on the basis of a ratio of web height A and flange width B of an H-shape steel 3 and other carrying condition, and carrying speed of a transfer 2 is controlled in response to size of the H-shape steel 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing overturning of H-section steel products when the H-section steel products are transported across a skid by a transfer with claws.

0002

[Prior Art] In a section steel rolling mill, a transfer with claws is used when taking products after rolling from the rolling line to a cooling bed, or when moving products laterally on sorting shelves to sort and organize them. ing.

FIG. 5 shows a conventional conveying means using a transfer with claws, in which a transfer with claws 2 is provided along a plurality of skids 1 laid in the transport direction of the arrow.
is pulled laterally by a wire rope or the like (not shown).

[0004] The H-shaped steel 3 placed on the skid 1 has its flange lower end 3a connected to the claw 2 of the claw-equipped transfer 2.
a, and is transported while sliding from a position on a roller table 4 connected to a rolling line to a predetermined position on the skid 1, for example.

[0005]

[Problem to be solved by the invention] By the way, skid 1
The web part of the H-beam 3 placed on top was erected vertically in order to maximize the number of H-beams that can be stored on the skid, or to prepare for the simultaneous installation of multiple H-beams in the next process. Placed in I position. However, if the product size is such that the flange width B is relatively small with respect to the web height A of the H-section steel 3, the product may fall over immediately after the claw 2a contacts the flange lower end 3a or during acceleration.

[0006] As a means of preventing the above-mentioned conventional conveyance equipment from falling over, a so-called inching operation that repeats low-speed advance and stop in small increments until the pawl 2a abuts against the lower end 3a of the flange, or There was a method of setting constant low acceleration and low conveyance speed according to the size of the product that is likely to tip over. However, these means have the disadvantage that the amount of transport throughput within a certain period of time is limited, leading to a decrease in efficiency.

[0007] Furthermore, Japanese Utility Model Application No. 63-144920 discloses a method in which a cart is reciprocated along a skid using the power of a transfer with claws, and an electromagnet that is detachable from the web of a section steel is attached to the cart. A new structure has been proposed.

[0008] However, this electromagnetic method requires the installation of a new trolley, and installation space is a problem when adding to existing transfer equipment, or a large number of trolleys are required depending on the length of the product, resulting in equipment costs. There was a problem with the increase in

[0009] The present invention enables rapid transfer without fear of overturning and increases the transfer ability by controlling the transfer speed according to the product size of the H-section steel without making any special modifications to the existing transfer device with claws. The purpose is to improve

0010

[Means for Solving the Problems] The gist of the present invention is to transport the lower end of the flange of an H-section steel placed in the I position on a skid laid in the transport direction while sliding it by a transfer with claws. , the skid is divided into three sections in advance in the conveyance direction: an air conveyance section, an initial conveyance section, and a latter conveyance section;
The transport speed in the initial transport section and the acceleration in the latter transport section are determined according to the ratio of the web height and flange width of the H-beam to be transported, and the transfer speed is controlled based on the transport speed and acceleration. This is a method for preventing overturning during skid conveyance of shaped steel.

[0011]

[Operation, Examples] The operation of the present invention will be explained in detail below based on the illustrated embodiment.

FIG. 1 is a schematic diagram of a transfer for carrying out the method of the present invention, and the same members as those in FIG. 5 are designated by the same reference numerals, and detailed explanation thereof will be omitted. The skid 1 laid in the transport direction of the arrow is divided into three sections in advance in its length direction: an air transport section L1, an initial transport period L2, and a latter transport section L3.

[0013] Air transportation section L1 is a transfer with claws 2.
This is the distance from the standby position P1 to the starting point P2 where the transfer of the H-shaped steel 3, which is the material to be conveyed, is started, and since this section L1 is the section where the claw 2a of the transfer with claws 2 is fed empty, it is not It is defined as section L1.

[0014] The initial conveyance section L2 is the roller table 4.
The range is from P2 to P3, which corresponds to both the left and right ends of
The H-shaped steel transported from the previous process by the roller table 4 in the direction perpendicular to the drawing is in this initial transport section L2.
Wait inside. That is, the H-shaped steel transported by the roller table 4 is located somewhere within this initial conveyance section L2, and for example, the H-shaped steel 31 shown by the imaginary line is located at the farthest left side.

[0015] The latter conveyance section L3 is the initial conveyance section L2.
This is the section from the end point P3 to the transport end point P4, which is set at an arbitrary transport distance, and shows the section in which the H-shaped steel on the skid 1 is substantially transported while sliding.

Now, as shown in FIG.
The lower end 3a of the flange of the H-shaped steel 3 placed in this position is held by the claw 2.
The conditions under which the H-shaped steel does not fall when it is pushed forward and transported while sliding are the overturning moment M1 and the stabilizing moment M.
2 must have the relationship M2 > M1 ·K. However, K is a coefficient determined by equipment conditions and product conditions.

The overturning moment M1 and the stabilizing moment M2 have the following relationship:

[0018]

[Math. 1] M2 = W・B/2
…■Formula M1 =F・A/2

…■Formula F=α・W/g
…■Formula v=α・t

…■Formula where, W: Weight of H-section steel (kgf) B: Flange width of H-section steel (m) A: Web height of H-section steel (m) F: Inertial force (kgf) α: Conveyance acceleration (m/s2) g: Acceleration of gravity (m/s2) v: Conveyance speed (m/s) t: Acceleration/deceleration time (sec)

[0019] The conditions for not falling are as described above: M2 > M
1 ・K, so by substituting ■ and ■ into this equation, we get
The number becomes 2.

[0020]

[Math 2]

[0021] Substituting the formula (2) into the formula (2) results in the following equation 3.

[0022]

[Math 3]

[0023] Therefore, the equation 4 is obtained.

[0024]

[Math 4]

Next, since α=v/t in equation (2), substituting this equation into equation (2) yields Equation 5.

[0026]

[Math 5]

[0027] Therefore, the equation 6 is obtained.

[0028]

[Math 6]

That is, once the ratio of the web height A to the flange width B of the H-section steel and the acceleration/deceleration time t are determined, the acceleration α and the acceleration that can transport the H-section steel on the skid without overturning can be determined by equations (1) and (2). The conveyance speed v is determined.

FIG. 2 is a graph showing elapsed conveyance time and changes in transfer speed in the present invention. The origin of the graph is when the transfer stops and the claw 2a is at the standby position P1.
Indicates the state in which In the following description, since the transfer and the claw 2a move together, the movement of the transfer will be described as the movement of the claw 2a.

When the H-shaped steel to be transported arrives within the initial transport section L2 and transport is started, the claw 2a first moves from a stopped state (velocity v0 = 0) to the air transport section L1 with an acceleration α1.
Accelerate to the end point P2. Acceleration α1 in this case
is not the acceleration α expressed by equation (2), but is an acceleration that can be set arbitrarily. In other words, the claws 2a within the air-feeding section L1 are merely air-feeded and do not come into contact with the H-shaped steel of the material to be conveyed.

When reaching point P2, the claw 2a is maintained at a constant conveyance speed v1, and moves within the initial conveyance section L2 at this conveyance speed v1. During the movement, the claw 2a comes into contact with the lower end of the flange of the H-beam placed on the skid, and slides the H-beam at the conveyance speed v1 until the claw 2a reaches the end point P3 of the initial conveyance section L2. transport. The conveyance speed v1 in this initial conveyance section L2 is the speed determined by formula (■), which is less than the speed determined by the ratio B/A of web height and flange width, the coefficient K determined by equipment conditions and product conditions, and the acceleration/deceleration time t. If so, the initial transport section L
2, it can be transported without fear of falling. Here, the acceleration/deceleration time t is a minute time from when the H-section steel in a stationary state begins to move until it reaches a constant speed v1, but in practice it may be determined empirically depending on the actual condition of the equipment.

Subsequently, when the claw 2a reaches the end point P3 of the initial conveyance section L2, that is, the start point of the latter conveyance section L3, it starts accelerating at an acceleration α2. Acceleration α2 is the acceleration determined by formula (2), and if the acceleration is less than this, the bicycle will not fall during acceleration.

Acceleration is continued until point P5, at which a predetermined late conveyance speed v2 is reached. The latter conveyance speed v2 is the speed at which the H-section steel is conveyed the longest distance within the latter conveyance section L3, and can be set, for example, to the maximum speed of the transfer equipment capacity.

When stopping the H-beam at a position P4 on an arbitrary skid within the latter transport section L3, deceleration is started from a point P6. The degree of deceleration at this time is the acceleration α
2 and the same absolute value as the negative acceleration α3 may be used. Note that since the acceleration α3 is fixed, once the stopping position of the H-beam is determined, the deceleration starting point P6 is automatically determined by back calculation.

FIG. 4 compares an example of the conveyance speed pattern by the conventional inching operation (FIG. 4(a)) and the conveyance speed pattern by the method of the present invention (FIG. 4(b)), both of which are shown at the start of idle running. The same conditions were used: the total distance from the point P1 to the conveyance end point P4 was 5.4 m, and the latter conveyance speed v2 was 1.0 m/s. In the conventional method, the entire process took 15 seconds, but according to the method of the present invention, the process could be completed in 9 seconds.

Speed control in the method of the present invention is easily possible by changing the speed of the drive motor of the transfer. For example, by inputting the dimensional data of the H-shaped steel into a programmable controller in advance, the H-shaped steel to be actually transferred can be controlled. Depending on the arrival of steel, a speed command may be given to the transfer drive motor via the thyristor conversion device. Of course, it is also possible to give a speed instruction each time depending on the H-beam to be transported by manual operation.

[0038]

[Effects of the Invention] The present invention enables high-speed transfer according to the size of the H-beam without fear of overturning when transferring the H-beam on a skid, thereby improving efficiency by shortening process time. This has the effect that a certain skid area can be used widely. In addition, the equipment cost is low because it can be carried out without making any special modifications to existing transport equipment.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an example of a transfer conveyance facility implementing the method of the present invention.

FIG. 2 is a diagram illustrating a conveyance speed pattern in the method of the present invention.

FIG. 3 is a diagram showing the positional relationship between the transfer claw and the H-section steel.

FIG. 4 is a diagram showing a conveyance speed pattern of a conventional method and a conveyance speed pattern of a method of the present invention.

FIG. 5 is a schematic side view illustrating a conventional transfer conveyance means.

[Explanation of symbols]

1 Skid 2 Transfer 2a Nail 3 H-beam steel 3a Lower end of flange 4 Roller table L1 Dry running section L2 Initial transport section L3 Late transport section

Claims (1)

[Claims] [Claim 1] I
When the lower end of the flange of an H-shaped steel placed in a posture is transported while being slid by a transfer with claws, the skid is divided in advance into three sections in the transport direction: an air transport section, an initial transport section, and a latter transport section. , the transport speed in the initial transport section and the acceleration in the latter transport section are determined according to the ratio of the web height and flange width of the H-beam to be transported, and the transfer speed is controlled based on the transport speed and acceleration. H
Method for preventing falls during skid conveyance of shaped steel.