[0001] The present invention relates generally to rolling apparatus including a plurality
of rolling mills arranged in series for progressive rolling of wire rods, steel sections,
steel bars or the like stock materials. In such rolling mill arrangement, twist roller
guide devices are employed in a continuous rolling operation in which the stock being
rolled is properly twisted between each two adjacent rolling mills from its state
as extended out'of the preceding mill so as to run into the following mill in a state
raised in transverse cross section vertically or, as with the case of a stock of rectangular
cross section, at an angle of inclination of 45 degrees and the guide devices are
each arranged adjacent to the exit of the preceding rolling mill to receive the stock
as extended therefrom and impart-to the stock an angle of twist required.- The present
invention relates particularly to twist roller guide devices of the kind described.
[0002] Generally, in the continuous rolling operation of a set of horizontal rolling mills,
it is requisite that the stock bar extended from between the working rolls of the
preceding rolling mill (which will be referred to hereinafter as the first rolling
mill) and having a longitudinal axis of cross section char is horizontal is twisted
in order that it may be introduced into the roll nip of the second or following rolling
mill with the cross-sectional axis raised to the vertical or at an angle of 45 degrees.
[0003] An advanced form of twist a roller guide device for rolling mill use includes a pair
of adjustable top and bottom twist rollers which receives the stock as extended from
the first rolling mill and having the longitudinal axis of cross section horizontally
directed and gives to the stock a definite angle of twist to place the cross-sectional
axis at a predetermined angle of inclination to the horizontal.
[0004] In operation, the steel bar or other stock received in the twist roller guide continues
to advance while turning gradually in accordance with the exact angle of twist given
by the paired twist rollers of the guide device and reaches the roll groove of the
second rolling mill, assuming a state raised as described above at the roll nip point.
With such guide devices arranged between the successive rolling mills, the stock is
rolled progressively, entering each of the rolling mills stably in a definite cross-sectional
attitude. This makes it possible at all times to obtain a desired high quality product
having an exact reduced cross-sectional shape and area.
[0005] Such technique of twisting a stock being rolled into a raised state of cross section
by use of a pair of twist rollers is generally considered highly reliable but involves
some problems as described below.
[0006] In the twist roller guide device, the paired twist rollers are set an angle corresponding
to the predetermined angle of twist to be given to the stock and, because of this,
if the stock as extended out of the first rolling mill in a state having a horizontally
directed longitudinal axis of cross section be introduced in that state into the paired
twist rollers, the forward end of the stock must come into collision with the twist
rollers and hence both the stock end portion and the twist rollers be heavily damaged.
[0007] To overcome this situation, it has been common practice to employ twist guide means
having a guide aperture or bore defined therein to receive the stock as extended out
of the first rolling mill. The guide bore has its wall surface twisted so that the
stock received therein is gradually preliminarily twisted before entering into engagement
with the twist rollers. As will be readily noted, a distance of stock travel exceeding
a definite length is necessary for the stock to be twisted to such an extent that
there is no excessive impact occuring between the twist rollers and the stock reaching
the latter. On the other hand, the paired twist rollers are supported by a rigid framework
so as to be able to grippingly hold the strip passing at high speed therebetween thereby
to impart to the stock a predetermined amount of twist, overcoming the rigidity of
the stock material. The framework is of a substantial size, including a centering
grip mechanism needed for fine adjustment of the distance between the twist rollers
to impart an optimum angle of twist to the stock, and is arranged to support the twist
rollers at its end adjacent to the second or next following rolling mill. The framework
itself is fixed on top of a firm rest far or support bed. Since the twist guide described
above and the framework supporting the paired twist rollers are arranged in series
with each other, the distance between the stock exit of the first rolling mill and
the paired twist rollers, that is, the axial length.of the twist roller guide device
used between the rolling mills tends to be considerably large.
[0008] Accordingly, in the past any rolling apparatus including a plurality of rolling mills
arranged in series must as a whole have a substantially large axial length as long
as if includes guide devices of the type described interposed between the rolling
mills. Contrariwise, where such rolling apparatus is installed in limited space, sometimes
it has been impossible to obtain between each two adjacent mills an axial distance
enough to accomodate a guide device of the type described and friction guide means
must be resorted to at the sacrifice of the rolling accuracy of the apparatus.
[0009] The present invention relates to twist roller guide devices of the type described
and is intended to overcome the difficulties previously encountered as described above.
[0010] The present invention has for its object the provision of a twist roller guide device
for rolling mill use the whole length of which is reduced to a minimum.
[0011] This object is attained by a twist roller guide device comprising the features of
claim 1.
[0012] The present invention provides a twist roller guide device of the character described
which is capable of twisting the stock being passed therethrough so as to impart thereto
a predetermined angle of twist without strain.
[0013] The present invention further provides a twist roller guide device which-has a minimized
overall length and is capable of giving an extremely accurate angle of twist to the
stock thereby to enable the associated rolling apparatus to operate with increased
smoothness and rolling accuracy so that products improved in quality are obtained.
[0014] To attain these features, the twist roller guide device of the present invention
is constructed and arranged as described below.
[0015] In the guide device, the twist guide member, which is arranged close to the exit
of the first rolling mill and has a guide bore defined therein to receive the stock
as extended out of the rolling mill, is formed in the following configuration, for
example, for stocks of elliptic cross section. Specifically, the lower half of the
wall surface of the guide bore consists of two laterally neighboring regions both
formed arcuate in transverse cross section, one side region serving as a twisting
surface slidingly engaging one half portion of the bottom surface of the stock having
an elongate elliptic or convex lens-like cross section. The other side region of the
lower wall surface of the guide bore is recessed more deeply than the stock-engaging
region to be clear of the stock. The top half of the wall surface of the guide bore
is formed in symmetry with the bottom half thereof with respect to the center line
of the guide bore. The top and bottom stock-engaging surfaces of the guide bore, which
are diametrally opposite to each other, are arcuate surfaces generally inclined, at
the stock-receiving end thereof, at the same angle as the corresponding regions of
the top and bottom surfaces of the stock of elliptic cross section now having a horizontal
major axis but extend helically about the bore axis, being twisted increasingly toward
the exit end of the guide bore, to serve as working surfaces effective to twist the
stock as it proceeds thereon. Obviously, the clearance surfaces are also helical along
the bore axis in .the same fashion as the stock-engaging surfaces. In this manner,
the guide bore forms along the major part of its length a twisted hole having smooth
wall surfaces gradually twisted along the bore axis. The stock once received in such
twisted hole obviously proceeds along the twisted-wall surfaces thereof while being
twisted thereby. That is to say, the stock is given a definite amount of preliminary
twist during its passage through the guide bore. The amount of twist imparted to the
stock by the twist guide is selected at a value slightly smaller than the angle of
twist ordinarily imparted by a pair of twist rollers.
[0016] The guide bore has a cross-sectional size varying along its longitudinal axis. Specifically,
it has an inlet end portion widely enlarged adjacent to a guide piece provided to
guidingly receive-the stock as extended from between the working rolls of the first
rolling mill and, inside of the enlarged end portion, is reduced in cross-section
size to such an extent as to approximately correspond to the cross section of the
stock to merge into the twisted hole region, which remains practically unchanged in
cross sectional area along its length reaching the exit end of the guide bore. As
described hereinbefore, in this last region are formed the twisting and clearance
surfaces of the twist guide. In most cases, the twist guide is of the structure divided
into two, top and bottom members, which are assembled into an integral tubular body
with the aid of an appropriate frame structure.
[0017] On the other hand, the paired top and bottom twist rollers are rotatably supported
on a guide box at its forward end portion by means of a pair of spaced bearing bracket
plates provided on the opposite sides of a roller holder, which is supported by the
guide box, which in turn is mounted on a rest bar. The paired twist rollers are each
of the previously known type consisting of a cylindrical-shaped section and a frustoconical-shaped
section and are arranged one over the other symmetrically in axially opposite directions.
[0018] According to a characteristic feature of the present invention, the roller holder
is made in the form of a hollow cylindrical member to fittingly receive the exit side
portion of the tubular body of the twist guide whereby the exit end of the latter
is held in closely spaced opposite relation to the paired top and bottom twist rollers.
[0019] The guide box is extended at its end adjacent to the first rolling mill toward the
latter and is formed on the extended end portion with a support base adapted to receive
the adjacent, inlet end portion of the twist guide whereby not only the twist guide
is supported with increased stability but the whole device can readily be made compact.
[0020] Further, in the device, the paired twist rollers are mounted on a pair of top and
bottom eccentric shafts extending between the bearing bracket plates and each supported
at one end on the respective bearing bracket plate by means of a bearing sleeve or
bushing rotatably fitted therein. In order to enable the two bearing sleeves to be
adjusted in angular position symmetrically with each other, a self-centering grip
control mechanism is provided. The hollow cylindrical portion of the roller holder,
having a cylindrical outer peripheral surface, is rotatably supported in a cylindrical
bore formed in the guide box and a worm gear plate is provided on a flange formed
on the hollow cylindrical holder portion for meshing engagement with a worm rotatably
mounted on the guide box. With such additional arrangement, not only the distance
between the axis of the paired twist rollers can be changed but also the angle of
inclination of the bearing bracket plates is adjustable and the angle of twist to
be given to the stock by the twist rollers can be finely adjusted with increased ease.
[0021] The above and other objects, features and advantages of the present invention will
become apparent from the following description when taken in conjunction with the
accompanying drawings, which illustrate a preferred embodiment of the invention.
[0022] In the drawings:
Fig. 1 is a side elevational view of a twist roller guide device embodying the principles
of the present invention, as employed in combination with an entrance roller guide
of a rolling mill;
Fig. 2 is a plan view of the twist roller guide device;
Fig. 3 is a fragmentary front view, partly in cross section, of the same;
Fig. 4 is a longitudinal cross-sectional view of the twist guide of the guide device
shown in Figs. 1 to 3, taken along the line IV-IV in Figs. 1, 5, 6 and 7;
Fig. 5 is a rear view of the twist guide, taken on the plane of the chain-dotted line
V-V of Fig. 4 looking in the direction indicated by the arrows;
Fig. 6 is a cross-sectional view of the same, taken along the chain-dotted line VI-VI
in Fig. 4; and
Fig. 7 is a front elevational view of the twist guide, taken on the plane of the chain-dotted
line VII-VII of Fig. 4, looking in the direction indicated by the arrows.
[0023] In Fig. 1, reference numeral 50 indicates a pair of working rolls of the first rolling
mill and the stock steel W as delivered therefrom, shown in this embodiment as having
a flattened, elongate elliptic cross section, is received first in a twist guide I
and, passing through a pair of top and bottom twist rollers 34, shown in chain-dotted
lines, is directed to an inlet roller guide 60 provided to guide the stock into the
second rolling mill not shown. The stock W rolled by the working rolls 50 is received
in the twist guide 1 in the state as delivered with the major axis of the elliptic
cross section held horizontal and is given a predetermined angle of twist by the paired
twist rollers 34, as indicated by the broken lines, before entering the inlet roller
guide 60. In the latter, the stock is progressively twisted, as it proceeds, in accordance
with the angle of twist of the inlet roller guide 60 so that when leaving the guide
60 the stock has its major cross-sectional axis directed substantially vertical, as
indicated in the right-hand end of Fig. 1. That is to say, the stock is twisted so
as to assumes a vertical attitude at its forward end at the instant when it reaches
the roll groove of the second rolling mill.
[0024] Referring to Figs. 1, 2 and 4, the twist guide 1 has a guide bore 10 formed therein
which extends axially through its body in the direction of the pass line.
[0025] Provided on the twist guide I at its inlet end are a pair of upper and lower guide
pieces 11, which together difine a guide opening effective to catch the incoming stock
W, and a pair of upper and lower guide projections 2, which serve to prevent the stock
from being withdrawn out of the guide bore as when it remains more or less closely
stuck in the roll groove of working rolls 50. As illustrated, the guide projections
are each extended into the roll groove in the adjacent one of the working rolls 50
and formed with a guide surface extending along the wall surface of the roll groove
in a direction tangential thereto and with a minimum spacing therefrom.
[0026] As observed from Figs. 4 and 5, the guide bore has an inlet opening 101 of substantial
size which is horizontally elongate and extends into the somewhat enlarged head portion
la of the twist guide, while rapidly and smoothly converging to merge into a twisted
portion of the guide bore, which will be described below. The twisted bore portion,
constituting the most part of the guide bore 10, is a through hole having a transverse
cross section elongated generally in a horizontal direction, as shown in Figs. 5,
6 and 7. Specifically, about one half (in Fig. 5, the right-hand half) of the lower
half portion of the twisted through hole is defined by an arcuate wall surface 10a,
corresponding to the right-hand lower half portion of the cross section of the-stock
W, while the other half of the lower half hole portion is defined by an arcuate clearance
surface 10b, which is set more deeply than the surface 10a. The upper half portion
of the twisted hole is formed in symmetrical relation to the lower half portion with
respect to the longitudinal axis of the twisted hole, the left-hand and right-hand
halves of the upper half hole portion being respectively defined by an arcuate surface
10a and a clearance surface lOb.
[0027] As shown in Fig. 5, the upper and lower arcuate wall surfaces 10a of the twisted
hole, which are diametrally opposite to each other, are generally inclined at the
inlet end thereof at the same angle as that of the corresponding surface regions of
the stock W as entering the twisted hole with its major cross-sectional axis horizontally
directed and are increasingly twisted along the hole axis toward the exit end 12 of
the twisted hole, as seen in Figs. 4 and 7, their angle of inclination varying increasingly
to attain a definite value at the hole exit end 12, to serve the purpose of gradually
twist the stock coming into sliding engagement with such hole wall surfaces. It goes
without saying that the clearance surfaces 10b are also increasingly twisted in accordance
with the twist of the working surfaces 10a to complete the twisted hole. In this manner,
the twisted hole is as a whole gradually and smoothly twisted, forming a major portion
of the guide bore 10 extending adjacent to the exit end thereof. As illustrated, there
is provided a laterally extending groove on each side of the twisted hole between
the adjacent working and clearance surfaces 10a and 10b. The side grooves are formed,
in cases where the twist guide is made as by casting in a form divided into two separate
top and bottom halves, as in this example, substantially in the plane in which the
two halves abut on each other. These grooves, are intended to serve the purpose of
preventing the formation of a sharp- edged shoulder on each hole side at the junction
of the adjacent twisting and clearance surfaces 10a and 10b which may impair the stock
or the wall surfaces of the twisted hole.
[0028] The two half sections of the twist guide 1 are assembled together in properly adjusted
relative positions to define a guide bore 10 exactly in specified configuration. For
example, as seen in Figs. 5, 6 and 7, a rectangular clamp frame is fitted over the
front end of the head portion of the twist guide 1 to fix four support beams 41 in
place, which are held previously against the body of the twist guide at four corners
thereof, so that the guide body is assembled into an integral tubular unit.
[0029] The tubular body of twist guide 1 is, as seen in . Figs. 1 and 7, beveled at the
exit end 12 at least at the top and bottom of the end face so that the exit of the
guide bore 10 (that is, of the twisted hole) may be placed fully close to a pair of
top and bottom twist rollers 34, which will be described below. The major portion
1b of the body of twist guide 1, which lies adjacent to the exit end thereof, is made
smaller in outside diameter than the head portion la of the twist guide for convenience
of fitting connection with the twist roller assembly.
[0030] Specifically, referring to Figs. 1, 2 and 3, the paired twist rollers 34 are supported
by a roller holder 14 which in turn is supported on a guide box of sturdy structure,
5. On the underside of the guide box 5 is firmly secured a bed plate of trapezoidial
cross section, 6, which is firmly secured to the top of a rest bar 20 with one of
the opposite side edge portions of the bed plate 6 tightly fitted in a recessed groove
24 formed at the top of rest bar 20 on one side thereof, the other side edge portion
of bed plate 6 being clamped against the rest-bar 20 by means-of a U-shaped clamp
piece 21. Reference numeral 22 indicates a clamp- tightening nut and 23 a side groove
formed in the adjacent side of rest bar 20 to receive one of the two legs of clamp
piece 21.
[0031] Referring again to Figs. 1, 2 and 3, the roller holder 14 is provided on the opposite
sides of its forward stock exit end portion with a pair of flat bearing plates 33
that extend in parallel longitudinally of the roller holder 14 to define a vertical
space therebetween in which the paired top and bottom twist rollers 34 are rotatably
supported. The twist rollers 34 are each of the known form consisting of two axial
half sections, one cylindrical in shape and the other flaring or diverging therefrom
in frustoconical shape. As seen in Figs. 2 and 3, the twist rollers 34 are arranged
one over the other in axially opposite directions, that is, in axial orientation opposite
to each other so that the frustoconical sections of the respective twist rollers 34
effectively cooperate to twist the stock W.
[0032] In the embodiment illustrated, the paired twist rollers 34 are rotatably mounted
on a pair of eccentric shafts 32, which are fixed at one end to respective bearing
sleeves or bushings 38 (only one of which is shown in fig. 3)in radially oppositely
offset relation thereto. The two bearing sleeves 38 are rotatably fitted in the respective
bearing plates 33 at different vertical locations'thereon. A pair of right-handed
and left-handed worm wheels 35 (Figs. 2 and 3) are fixedly secured to the outer ends
of upper and lower bearing sleeves 38, respectively, and are held in mesh respectively
with right-handed and left-handed worms 36 fixed by mounted on a common mandrel 37,
which is journaled in a bracket 39 provided therefor. With this arrangement, it will
be readily noted that the shafts of two twist rollers 34 can be vertically displaced
symmetrically with each other, by turning the mandrel 37 about its axis, for example,
by applying a tool such as a wrench to the square head of the mandrel 37 formed at
one end thereof.
[0033] The present invention is characterized in that the roller holder 14, serving to support
the paired twist rollers 34, has a body portion formed in hollow cylindrical shape
to fittingly receive the axially forward portion of the tubular body of twist guide
1.
[0034] As illustrated in Fig. 1, the hollow cylindrical portion of the roller holder 14
has a cylindrical outer peripheral surface and is rotatable supported by a bored support
bracket 65 formed integrally on the guide box 5 adjacent to the forward end thereof.
The roller holder body is formed at the forward end thereof with a radial flange 140,
which is held on the front end face of the support bracket 65, and carries stop screws
19 set to engage the rear end face of the bracket 65 so that the roller holder 14
is securely held in place against axial dislocation relative to the support bracket.
[0035] The flange portion 140 of roller holder 14 is extended upwardly at its top to form
a worm wheel segment 141 thereon, which is placed in mesh with a worm 16 fixedly mounted
on a shaft journaled at its opposite ends in respective bearing brackets 15, which
are provided on top of the support bracket 65. As will readily be noted, when the
worm shaft is turned, the roller holder 14 rotates about the axis of the cylindrical
outer peripheral surface of its hollow cylindrical body portion. Reference numeral
17 indicates the square- headed oppcsite ends of the worm shaft and 18, positioning
nuts thereon.
[0036] The guide box 5 is rearwardly extended to form a U-shaped bracket portion designed
to support the enlarged head portion la of the twist guide described above. Reference
numeral 55 indicates retainer plate means secured to the top of the U-shaped bracket
portion by bolts 7.
[0037] In the device described, the twist guide 1, supported together with the roller holder
14 on the guide box 5 secured to the top of rest bar 20, is apparently held with the
axis of its guide bore 10 coinciding with the pass line of the rolling mills, with
which also the axis of the hollow cylindrical portion of the roller holder 14 coincides.
Further, it is to be noted that the top and bottom bearing sleeves 38 fitted to respective
bearing plates 33 are held in positions symmetrical with each other with respect to
the pass line. ,
[0038] Accordingly, as long as the twist guide 1 is axially positioned with its beveled
exit end 12 held as closely as possible to the paired twist rollers 34, the exit end
opening of guide bore 10 is centered on the pass line extending through the twist
roller set and at a point fully close thereto. On the other hand, the inlet end region
of twist guide 1 is arranged, as described previously, with its guide projections
20 held extremely close to the working rolls 50 of the first rolling mill. It will
be apparent that the rest arm 20 serves to support the whole assembly of the twist
roller guide device of the present invention.
[0039] In operation, the stock W as extended from between the working rolls 50 is immediately
received in the twist guide 1, is preliminarily twisted as it proceeds therethrough
slidingly engaging the twisted surfaces 10a, and then is fed out of the exit end 12
of twist guide 1 into the pair of twist rollers 34, which are positioned extremely
close to the exit end 12. As stated before, the angle of twist given to the stock
W by the twist guide is smaller than that ordinarily given thereto by twist rollers
34.
[0040] The paired twist roller 34 give the stock W a predetermined angle of twist that can
be finely adjusted, for example, by turning the bearing sleeves 38 and/or the roller
holder 14.
[0041] As the angle of twist given to the stock W by the twist rollers is larger than that
preliminarily given thereto by the twist guide 1, the stock once reaching the twist
rollers 34 remains no longer in the state tightly engaging the twisted, working surfaces
of the twist guide. The stock, leaving the twist rollers, proceeds while turning in
accordance with the angle of twist finally given thereto and reaches the entrance
of the second rolling mill with the major axis of its cross section held vertical
as long as the given angle of twist is correct.
[0042] In conventional twist roller guide devices, a twist guide has been provided which
takes the form of a separate part having a required length and supported adjacent
to the exit of the first rolling mill and, next to such twist guide, a roller support
has been arranged which supports a pair of twist rollers on its forward end portion.
With this arrangement, it is required that the roller support and the first rolling
mill be spaced from each other substantially by a distance enough to accommodate the
whole length of the twist guide therebetween. In addition, the distance between the
twist guide and the twist rollers must be of a length enabling arrangement of the
support frame.
[0043] In contrast to this, in the device of the present invention, there is no need for
any extra space between the exit of the first rolling mill and the paired twist rollers
34 beyond the net length required for the twisted surfaces of twist guide I to impart
a desired preliminary twist to the stock. Accordingly, the whole of the device can
be assembled in a length much reduced compared with conventional devices.
[0044] Further, in the device of the present invention, since the twist guide 1 has a length
enough to impart to the stock a desired preliminary twist and the stock leaving the
exit end of its twisted hole is immediately fed to the paired twist rollers, there
is no danger that the stock be undesirably deformed on its way or its introduction
to the paired twist rollers fail.
[0045] It will be apparent that the twist roller guide device of the present invention enables,
because of its reduced length, a substantial reduction in distance between the first
and second rolling mills and thus makes it possible to minimize the total length of
the pass line in any number of rolling mills arranged in series.
[0046] A further advantage of the present invention is that it enables use of a highly accurate
stock guide, of the twist roller type, between two rolling mills arranged rather closely
to each other.
[0047] Though one preferred embodiment of the present invention has been shown and described,
it will be apparent to those skilled in the art that various changes and modifications
may be made therein without departing from the spirit of the invention or the scope
of the appended claims.
[0048] Shortly summarized the invention comprises a twist roller guide having a minimized
overall length, including a guide box, a twist guide member having a twisted through
bore for giving preliminary twist to the stock passing therethrough, and a roller
holder consisting of a hollow cylindrical body portion and a pair of bearing plates
extending forwardly therefrom to support a pair of twist rollers therebetween. The
twist guide member consists of an enlarged head portion defining an inlet opening
therein and a tubular body portion, the head portion being fitted in a bracket portion
of the guide box formed adjacent to the rear end thereof. The body portion of the
twist guide is fitted in the hollow cylindrical body portion of the roller holder,
which is firmly supported in another bracket portion of the guide box formed adjacent
to the front end thereof. The twist guide is beveled at the top and bottom of its
exit end face so that it may be placed fully close to the twist rollers.