JPH0367763B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a wire drawing apparatus using a roll bending method. In the conventional general wire drawing process, the material was first descaled through a pickling process, then subjected to a lubrication base treatment, sent to a pre-die lubrication process, and then wire drawn using a hole die. . In recent years, a method of simultaneously performing descaling and wire drawing using roll bending wire drawing has been developed. For example, Utility Model Application No. 53-101036, Utility Model Application No. 54-
In the straightening device disclosed in No. 33439, etc., or the scale peeling device disclosed in Utility Model Application Publication No. 110017, etc., the purpose is straightening or peeling off scale, so the wire rod's yield point is exceeded. It is sufficient to give the wire an elongation of
The maximum growth rate will not exceed 10%. Therefore, the roll diameter is usually larger than the roll pitch. Even when the roll diameter is smaller than the roll pitch, the roll diameter is at least 20 times the wire diameter. On the other hand, since the main purpose of roll bending wire drawing is wire drawing, the elongation can exceed 60% at most. Therefore, the roll diameter and roll pitch are also reduced as will be described later. As shown in FIG. 1, in a conventional roll bending wire drawing device, for example, five grooved rolls R arranged in a staggered manner on the same plane are assembled into a housing H as one unit. The roll axis of each unit is oriented alternately in the vertical and horizontal directions, and the wire material W is repeatedly stretched and bent to peel off and remove surface scale, while at the same time utilizing the elongation at that time. The device also allows wire drawing to be performed. However, such conventional roll bending wire drawing apparatuses have relatively large roll diameters and roll pitches, and a large number of rolls, so that the entire apparatus is large and requires a large amount of installation space. In addition, in terms of the quality of the finished product, the wire rod tends to twist when passing through the rolls, and the wire rod surface is prone to scratches due to the influence of the grooved rolls. Furthermore, in terms of efficiency, the amount of elongation per roll is small, and the manufacturing cost of the rolls is also high. An object of the present invention is to provide a roll bending wire drawing device that eliminates the various drawbacks of such conventional wire drawing devices, and to improve the quality of the product and economically construct the device. Generally, when bending wire drawing is performed, if the roll pitch is constant, the wire will be twisted and hit the groove walls of each roll, causing scratches. This tendency becomes even greater when the roll diameter is large or the roll pitch is large, since the restraint force on the wire is weakened, which promotes twisting of the wire. The reason for this will be explained below. When bending a plate material up and down, the plate material is restrained from above and below in the width direction by the rolls, so no twisting of the plate material occurs, and effectively the wavy bending is repeated. However, in the case of a wire rod, since its lateral surface is circular, no horizontal restraint by the upper and lower rolls occurs when vertical bending is performed. The X and Y axes of an arbitrary wire cross section when the wire is first bent upwards and the X' and Y' axes of the same wire cross section when the wire is then bent downward are determined by the errors of each roll and wire. Therefore, they do not match exactly. This discrepancy between the X and Y axes causes a discrepancy in the residual stress in each bend, resulting in twisting in the circumferential direction of the wire. This twist occurs in a spiral in the longitudinal direction of the wire, causing the wire to meander. This meandering causes the wire to come into irregular contact with the groove wall portion of the grooved roll, causing scratches on the surface of the wire and scratches due to the difference in mutual circumferential speed. The present invention focuses on this point and is characterized by a structure in which the roll diameter and roll pitch of the apparatus are reduced, and the apparatus is mainly composed of flat rolls without groove walls. As shown in FIG. 2, the apparatus of the present invention combines a pair of small-diameter flat rolls 2a, 2b and one roll-down roll 3 and houses them as one unit in a housing 1, and this housing is arranged in two or two units. Two or more wires are connected in series to form a wire drawing process. The flat rolls 2a and 2b have a relatively small roll diameter D, and only the roll-down roll 3 is a grooved roll and is placed at an intermediate position between the flat rolls 2a and 2b, so that it can be adjusted and moved in the rolling direction. . The valley diameter of the reduction roll 3 is approximately the same as the roll diameter D of the flat rolls 2a and 2b. As shown in FIG. 2, the pitches P between the roll axes (hereinafter referred to as roll pitches) of these roll groups 2a, 3, and 2b are arranged substantially on a straight line. However, the maximum amount of movement e (FIG. 2) of the reduction roll 3 in the direction of reduction of the wire rod W is set to be approximately equal to the roll diameter D. These three rolls are arranged in a straight line with a relatively small pitch. In the present invention, in order to effectively perform the wire drawing action and to prevent the device from increasing in size, the roll diameter D of the fixed rolls 2a and 2b is set to 7 times or less the wire diameter d, and 3 The roll pitch P of the book roll is set to be 8 times or less the wire diameter d. If the roll diameter D exceeds 7d, there is a drawback that the wire drawing effect decreases and the entire device becomes larger. The roll pitch P becomes P=8d when the reduction roll 3 is moved to the maximum, so P is 8d (=D
+d). Note that specific examples that meet the above conditions are shown in Table 1, which will be described later. When connecting the housings 1 containing these rolls, as shown in FIGS. 2 and 3, they are connected in series with an angular difference of 90° from each other.
The passing wire W is bent in the vertical direction and in the horizontal direction so as to be uniformly drawn. In addition to the method shown in FIG. 2, as a method of connecting three or more housings, there is also a method of connecting them in series with an angular difference of 120 degrees from each other. Guide rolls 4 are fixedly arranged on the entrance and exit sides of the wire drawing line introduced into the housing 1. As shown in FIG. 3, this guide roll consists of two horizontal rolls 41 arranged in parallel and two horizontal rolls 41 arranged in parallel
The vertical rolls 42 of books are combined in a grid pattern, and a guiding space is formed in the center to allow the wire rod W to fall, and small-diameter idle rolls are used. Generally, guide rolls are installed at the entrance and exit sides of the device to ensure that the wire progresses toward the pass line. Since the apparatus of the present invention uses flat rolls 2a and 2b on the entry and exit sides, it is necessary to guide the guide more reliably than usual, and also to take measures against scratches and the like into consideration. Therefore, parallel guide rolls are essential. The wire drawing mechanism A configured in this manner is fixedly installed on the main body base B as shown in FIG. form the entire device. Note that the wire drawing device may have a configuration other than that shown in Fig. 4, in which a correction mechanism is provided on the entry side of the wire drawing mechanism, or in cases where correction mechanisms are provided on both the entry side and the exit side of the wire drawing mechanism. , or only a wire drawing mechanism without a straightening mechanism, and various forms are selected depending on the required degree of straightness of the finished product. Next, the operation of this device will be explained. In this device, the wire rod W is first introduced into a horizontal bending mechanism by guide rolls 4, and then introduced one after another into a vertical bending mechanism, where it is bent in the vertical and horizontal directions, and descaling and wire drawing are performed simultaneously. be exposed. In each bending mechanism, the grooved reduction roll 3 has the primary function of applying tension to the wire rod W, but its function as a guide roll is also emphasized, preventing the pass line from slipping and keeping the wire rod. Effectively acts to prevent waviness. The wire rod that has undergone the wire drawing process passes through a straightening mechanism to improve its straightness, and is then led out of the apparatus. Table 1 shows a performance comparison between the wire drawing apparatus according to the present invention and a conventional roll bending type wire drawing apparatus. The processing conditions in the example shown in Table 1 are as follows. Conventional roll pitch device: P=240mm Inventive device: P=80mm Wire drawing speed V≒50m/min

[Table] As described above, the bending wire drawing device according to the present invention can reduce the size of the entire device by setting D≦7d and P≦8d, and by mainly using flat rolls, the bending wire drawing device according to the present invention can be made smaller due to twisting of the wire. Since the occurrence of scratches and scratches can be reduced, the quality of finished products can be significantly improved. Furthermore, since the center of the roll configuration is a flat roll, the cost of manufacturing the roll can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a side view of the main parts of a conventional roll bending wire drawing device. FIG. 2 is a side view of the main parts of the bending wire drawing apparatus according to the present invention. FIG. 3 is a perspective view showing the roll configuration of the apparatus of the present invention. FIG. 4 is an overall side view of the device of the present invention. 1: Housing, 2a, 2b: Flat roll, 3:
Reduction roll, 4: Guide roll, W: Wire rod.

Claims (1)

[Claims] 1. In an apparatus for drawing wire rod W using the roll bending method, a pair of small diameter flat rolls 2a, 2
b are arranged in parallel at a predetermined interval, and a small-diameter grooved reduction roll 3 is arranged between the two rolls 2a and 2b so that the reduction movement can be freely adjusted, and the three roll groups 2a,
3 and 2b are housed in a housing 1 as one unit, at least two of the housings are connected in series with the axes of each roll group having an angular difference of at least 90 degrees, and the wire rod is passed between the roll groups. A pair of horizontal rolls 41 and a pair of vertical rolls 4 are arranged in parallel at intervals of the same size as the diameter of the wire.
Each housing 1 has a guide roll 4 in which a wire guide space is formed in the center by combining 2 and 2 in a grid pattern.
The groove diameter of the roll-down roll 3 is set to be approximately equal to the roll diameter D of the flat rolls 2a, 2b, and the maximum rolling movement amount of the roll-down roll is set to be approximately equal to the valley diameter. Set the same, the flat roll 2
The diameter D of the rolls a and 2b is 7 times or less the diameter d of the wire rod, and the pitch P between the shafts of the roll groups 2a, 3, 2b is
A bending wire drawing device characterized in that the wire diameter d is set to 8 times or less the wire diameter d.