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(11) | EP 1 308 241 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Brushing apparatus with reciprocating roll |
| (57) The invention provides a brushing apparatus hardly affected by metal powder and the
cleaning water during the brushing operation and free from damage caused by the contact
with the metal strip (P). The brushing apparatus of the invention reciprocates in the width direction of the metal strip (P) with its brush roll stand being controlled by a control unit. The brushing apparatus comprises position sensors (100) for detecting the width direction edges of the metal strip (P), wherein the position sensors (100) are provided with emitting portions (101) each located in a position corresponding to an end of the brush roll for emitting linear flows of water or air, etc. from a side above or below the metal strip (P) to the other side and receiving portions (102) for receiving the linear flows and outputting detection signals to the control unit. |
TECHNICAL FIELD
[0001] The present invention relates to a brushing apparatus with a reciprocating-roll, and more particularly, to a brushing apparatus with a reciprocating-roll provided with position sensors for detecting the width direction edges of a belt-shaped metal sheet (hereinafter referred to as "metal strip"), which is to be brushed, traveling in the longitudinal direction.
BACKGROUND ART
[0002] In the metal strip manufacturing lines of steel mills, etc., brushing of metal strips is conducted using brushing apparatuses. Usually, a brush roll having a length greater than the width of the metal strip is used. The brush roll is worn down in a manner that the areas beyond the side edges defining the width of the metal strip remains unworn because they are free from frictional contact with the metal strip. This makes it difficult to use the same brush roll for a wider metal strip, and therefore the range of widths for which the brush roll can be used decreases.
[0003] To prevent such uneven frictional wear, a brush roll apparatus has been proposed, in which brushing is conducted while making the brush roll reciprocate at a predetermined stroke in the width direction of the metal strip. The brushing operation performed with a predetermined stroke cannot satisfactorily prevent this uneven frictional wear as metal strips move in a zigzag direction to some degree. Therefore, the applicant has developed a brushing apparatus in which a brush roll reciprocates in the direction of the metal strip width (Japanese Unexamined Patent Publication No. 1993-208359). This apparatus is usable for a metal strip having a variable width. This apparatus is also usable even in the case where another metal strip having a different width is welded to the metal strip. When the brush roll reaches the longitudinal end portion of a metal strip, the apparatus continues the brushing operation of the welded next metal strip and thereby improving efficiency of the operation.
[0004] Fig. 8 shows a plan view and a front view illustrating a prior art brushing apparatus. Figs. 9(a) and 9(b) are perspective views showing a position sensor 900 which is used in a brushing apparatus and detects side edges of a metal strip.
[0005] In Fig. 8, a brush roll stand 1 is provided with two brush rolls 2 for brushing a metal strip P and the brush rolls 2 are rotated by two motors 5. These elements compose a brushing section. Beneath the brush roll stand 1, guide rails 3 and linear bearings 4 are provided for guiding the movement of the brushing section. The brush roll stand 1 and the motors 5 are made to reciprocate in the width direction of the metal strip P by a driving member 7 comprising a variable speed servo-motor 6, a feed screw and a ball screw (both screws are not shown). A base 910 of a position sensor 900 is fixed to the brush roll stand 1.
[0006] As shown in Figs. 9(a) and 9(b), the position sensor 900 is composed of a stopper 901, an arm 902, a rod 903, a slit plate 904 having a slit 906, and a switch fixing unit 905. In the switch fixing unit 905, an emitting member 907 and a receiving member 908 of a photoelectric switch are arranged facing each other. As the light emitted from the emitting member 907 of the photoelectric switch, a directional light ray, such as a laser beam exhibiting little diffusion, is suitably used. The receiving member 908 receives the light emitted from the emitting member 907 and transmits a receiving signal via a cable (not shown) to a control unit (not shown) controlling the servo-motor 6.
[0007] The arm 902 can rotate around an axis 909. The arm 902 is equipped with a returning means (not shown) such as a spring, etc., which allows the arm to return to its initial position when released from an external force after being shifted by the external force. In the initial state, the stopper 901 is disposed in a position closer to the metal strip side than the axis 909. It is arranged so that the path of the light emitted from the emitting member 907 of the photoelectric switch is a predetermined distance away from the slit 906 and the slit plate 904 blocks the light. When the brushing operation is started, the brush rolls perform a reciprocating motion in the axial direction by the reciprocating movement of the brush roll stand 1, and the two position sensors 900 also reciprocate.
[0008] In order to prevent uneven frictional wear of the brush rolls, the position sensors 900 are mounted on the brush roll stand 1 so that the stoppers 901 are located at the ends of the brush rolls. During the brushing operation, due to the reciprocating motion of the brush roll stand 1 and the zigzag movement of the metal strip P, the stoppers 901 of the position sensors 900 and the side edges of the metal strip P come into contact with each other. The metal strip P presses the stopper 901 to move the slit plate 904. On the other hand, the switch fixing unit 905 is fixed to the brush roll stand 1. Thereby, when the stopper 901 and the slit plate 904 are moved a predetermined distance by the metal strip P, the slit 906 reaches the position where the light transmitted from the emitting member 907 of the photoelectric switch passes through the slit 906. Accordingly, the receiving member 908 outputs the received signals to the control unit. When the control unit determines that the metal strip P is in contact with the stopper 901, it shifts the traveling direction of the brush roll stand 1 to the direction to which the stopper 901 was pressed. In this manner, the brush roll 2 performs a reciprocating motion within the width of the metal strip P.
[0009] The metal strip to be brushed may be thin and have very sharp side edges like a cutter or it may be thick and have untreated serrate side edges. In these cases, even a slight contact with the metal strip P causes damage to the position sensor 900 and wobbling which adversely affects the accuracy of position detection. In order to prevent an excessive pressure of contact with the metal strip P, the position sensor 900 is provided with a retracting system (not shown) for promptly pulling back the stopper 901 when even a slight contact with the metal strip P is defected. The control unit, upon receiving signals from the receiving member 908, reverses the brush roll 2 and, at the same time, promptly detaches the stopper 901 from the metal strip by operating the retracting system.
[0010] In the above described position sensor usable for detecting the side edges of a metal strip, the photoelectric switch portion must be located away from the stopper to keep its electric circuit portion away from metal powder and the cleaning water directed to the metal strip during the brushing operation, leading to a complicated structure thereof.
[0011] The mechanical portion of the above position sensor has drawbacks such as a less smooth movement affected by the cleaning water and the metal powder and play caused by contact with the metal strip, resulting in lowered detection accuracy.
[0012] Furthermore, the above position sensor requires a mechanism for preventing damage caused by contact with the metal strip, high detection accuracy for promptly retracting the stopper thereof and frequent maintenance of the position sensor.
DISCLOSURE OF THE INVENTION
[0013] An object of the present invention is to overcome the foregoing prior art drawbacks. More specifically, the object of the present invention is to provide a brushing apparatus with a reciprocating-roll equipped with position sensors detecting side edges of a metal strip which are hardly affected by metal powder and the cleaning water during the brushing operation and free from damage caused by the contact with the metal strip.
[0015] A brushing apparatus with a reciprocating-roll of the present invention comprises a brushing section provided with a brush roll for brushing a metal strip, a driving device for rotating the brush roll, and a brush roll stand for supporting the brush roll and the driving device; a transfer device for shifting the brush roll stand; a control unit for controlling the transfer device in a manner that the brush roll stand performs a reciprocating motion in the metal strip width direction; and position sensors mounted on the brush roll stand at positions corresponding to both ends of the brush rolls for detecting the side edges of the metal strip, each of which position sensors being provided with an emitting portion located in a position corresponding to an end of the brush roll for emitting a linear flow of liquid including water or gas including air from a side above or below the metal strip to the other side, and a receiving portion located on the opposite side of the metal strip from the emitting portion for receiving the linear flow of liquid including water or gas including air and outputting a detection signal toward the control unit based on the presence or absence of the linear flow.
[0016] The receiving portion can be provided with a casing having an aperture in one end thereof for receiving the incident linear flow and a detection piece held in the casing, wherein the detection piece is movable in the casing, and when the linear flow does not enter thereinto the detection piece is located on the aperture side of the casing, and when the linear flow enters thereinto the detection piece is shifted to the other end of the casing by the linear flow.
[0017] The detection piece can be held so as to vertically move in the casing when struck by the linear flow.
[0018] It is also possible to hold the detection piece so as to rotate in the casing when struck by the linear flow.
[0019] The receiving portions can incorporate a switch for outputting the detection signals to the control unit based on the movement of the detection piece.
BRIEF DESCRIPTION OF THE DRAWING
[0020] Fig. 1 is a front view showing the area around the position sensor of a brushing apparatus with a reciprocating-roll according to one embodiment of the present invention.
[0021] Figs. 2(a) and 2(b) are longitudinal sectional views of the receiving portion of the position sensor of Fig. 1. Fig. 2(a) shows a condition where a water jet is entering and Fig. 2(b) shows a condition where a water jet is not entering.
[0022] Figs. 3(a) and 3(b) are cross-sectional views showing the shape of a flange mounted on a detection piece.
[0023] Figs. 4(a) to 4(c) are schematic diagrams illustrating an operation for detecting side edges of a metal strip.
[0024] Fig. 5 is a longitudinal sectional view showing the position sensor according to another embodiment of the invention.
[0025] Figs. 6(a) and 6(b) are longitudinal sectional views of the receiving portion of the position sensor of Fig. 5. Fig. 6(a) shows a condition where a water jet is entering and Fig. 6(b) shows a condition where a water jet is not entering.
[0026] Figs. 7(a) and 7(b) are longitudinal sectional views of the receiving portion of the position sensor according to still another embodiment of the invention. Fig. 7(a) shows a condition where a water jet is entering and Fig. 7(b) shows a condition where a water jet is not entering.
[0027] Fig. 8 shows a plan view and a front view of a prior art brushing apparatus with a reciprocating-roll.
[0028] Fig. 9(a) is a perspective view showing a prior art position sensor and Fig. 9(b) is a perspective view illustrating the positional relationship between a photoelectric switch and a slit.
BEST MODE OF CARRING OUT THE INVENTION
[0029] Hereinafter, embodiments of the invention will be described with reference to the drawings. Fig. 1 is a front view of a brushing apparatus with a reciprocating-roll according to one embodiment of the invention. The figure illustrates the portion where a position sensor is mounted and the area therearound.
[0030] The brushing apparatus body has the same structure as shown in Fig. 8, which comprises a brushing section, a transfer device for shifting a brush roll stand and a control unit for controlling the transfer device. At a predetermined interval, two position sensors 100 are attached to positions near the ends of a supporting means 120 via positioning means 110 which can adjust the attaching positions in the horizontal direction on the brush roll stand 1. The position sensor 100 comprises an emitting portion 101, a receiving portion 102 and a pipe 103. Water pressurized by a pump (not shown) is supplied through the pipe 103 and discharged from the emitting portion 101 toward the receiving portion 102, i.e., from bottom to top, as a linear flow.
[0031] Figs. 2(a) and 2(b) are longitudinal sectional views showing the receiving portion 102. Fig. 2(a) shows a condition where a water jet is entering and Fig. 2(b) shows a condition where a water jet is not entering. The receiving portion 102 is provided with a high-frequency induction type proximity switch 201, a tubular body 204 having an open bottom end and a release hole 205 formed on its upper end, a detection piece 202 comprising a supporting body made of resin or like non-conductive materials and a conductive part 203 made of metal, etc. held in the supporting body, and a U-tube 206 connected to the release hole 205. When the receiving portion 102 is receiving the water jet W emitted from the emitting portion 101, the detection piece 202 is pressed up by the water jet W and the conductive part 203 is mounted away from the proximity switch 201 (Fig. 2(a)). When the receiving portion 102 is not receiving the water jet W, the detection piece 202 is located at the bottom of the tubular body 204 owing to the gravity and the conductive part 203 of the detection piece 202 is located in the vicinity of the proximity switch 201 (Fig. 2(b)).
[0032] The high-frequency induction type proximity switch 201 generates a high-frequency magnetic field therearound by an oscillator (not shown) held in the switch. If a conductive part exists therearound, the high-frequency magnetic field generates an eddy current on the surface of the conductive part. It is possible to detect the presence of the conductive part by the variance of the oscillation levels of the oscillator caused by the energy loss from the eddy current. Therefore, as shown in Figs. 2(a) and 2(b), by the detection of the positional change of the conductive part 203 disposed in the detection piece 202 by the proximity switch 201, it is possible to determine if the water jet from the emitting portion 101 is reaching the receiving portion 102.
[0033] The release hole 205 helps the detection piece 202, which is pressed against the upper end of the tubular body 204 by the water jet W, to promptly come down when the water jet W stops entering into the tubular body 204. The U-tube 206 prevents the cleaning water sprayed during the brushing operation from entering into the inside of the tubular body 204. The top and bottom ends of the detection piece 202 are flanged for making its vertical motion in the tubular body 204 smooth. In order to promptly remove the water in the gap between the tubular body 204 and the detection piece 202, it is preferable that the flanges be shaped so that, for example, their circumferences partly touch the inner side of the tubular body 204 (Fig. 3(a)) with circumferentially repeated gaps or release holes are formed therein (Fig. 3(b)), etc. Figs. 3(a) and 3(b) are cross-sectional views of the receiving portion of Fig. 2(b) taken along the line III-III.
[0034] Next, a process detecting the side edges of a metal strip using the position sensor 100 shown in Figs. 1, 2(a) and 2(b) will be explained.
[0035] Figs. 4(a) to 4(c) show the positional relationship of the brush roll 2 (the bottom brush roll is not shown), the metal strip P and the two position sensors 100 (the emitting portions 101 and the receiving portions 102). Fig. 4(a) shows the initial state before starting brushing operation in which the emitting portions 101 and the receiving portions 102 are disposed in positions corresponding to the ends of the brush roll 2.
[0036] Upon starting the brushing operation, the brush roll stand 1 begins brushing while reciprocating in the longitudinal direction thereof. Water is ejected from the emitting portion 101 to the receiving portion 102 and the detection piece 202 is maintained in the pressed up position by the water. Here, it is assumed that the brush roll stand 1 shifts to the right from the position shown in Fig. 4(a). The brush roll 2 and the position sensors 100 fixed to the brush roll stand 1 also shift to the right. Therefore, as shown in Fig. 4(b), the left end of the metal strip P reaches a position which blocks the water ejected from the left side emitting portion 101. Thereby, the water jet W does not reach the receiving portion 102 and the detection piece 202 comes down (Fig. 2(b)). In this case, as described above, the proximity switch 201 outputs detection signals indicating that the left end of the metal strip P is in the predetermined position, i.e., the left end of the brush roll 2. The control unit (not shown) receives the detection signals transmitted from the proximity switch 201 via a signal cable 207 and shifts the traveling direction of the brush roll stand 1 to the left in order to make the brush roll 2 move to the left.
[0037] Fig. 4(c) shows the condition where the right position sensor 100 detects that the right end of the metal strip P has reached the right end of the brush as the roll stand 1 has shifted to the left. In this case, the control unit receives detection signals from the proximity switch 201 and shifts the traveling direction of the brush roll stand 1 to the right.
[0038] As explained above, uneven frictional wear of a brush roll can be prevented by providing the position sensors 100 at positions corresponding to the ends of the brush roll 2 which is wider than the metal strip P and by reversing the moving direction of the brush roll stand 1 when one of the position sensors 100 detects the arrival of the end of the metal strip P. Even when a right-and-left zigzag motion of the metal strip P is added, it is possible to detect the ends of the metal strip P. Furthermore, the detection of the ends of the metal strip can be performed when the width of the metal strip P varies.
[0039] Fig. 5 is a cross-sectional view showing the position sensor 500 according to another embodiment of the invention. Similar to the position sensor 100 shown in Fig. 1, the position sensor 500 is equipped with an emitting portion 501 and a receiving portion 502. However, they are disposed in the positions opposite to those of the emitting portion 101 and the receiving portion 102 shown in Fig. 1. Figs. 6(a) and 6(b) are cross-sectional views showing the position sensor 500 in Fig. 5. Fig. 6(a) shows the condition where water jet W is entering and Fig. 6(b) shows the condition where water jet W is not entering.
[0040] Like that shown in Figs. 2(a) and 2(b), the position sensor shown in Figs. 6(a) and 6(b) comprises a proximity switch 601, a tubular body 604, a detection piece 602 holding a conductive part 603 therein, and a release hole 605 and further comprises a spring 606. In the structure shown in Fig. 6(a), the detection piece 602 is pressed down by a water jet W exerting a water pressure stronger than the resilience of the spring 606. Therefore, the conductive part 603 is moved away from the proximity switch 601. In Fig. 6(b), the spring 606 expands so as to move the detection piece 602 to the upper part of the tubular body 604, causing the conductive part 603 to move close to the proximity switch 601.
[0041] Figs. 7(a) and 7(b) are cross-sectional views showing the position sensor 700 according to still another embodiment of the invention. The position sensor 700 shown in Figs. 7(a) and 7(b) differs from the position sensor 100 shown in Fig. 1 in the structure of the receiving portion 102. A receiving portion 702 shown in Figs. 7(a) and 7(b) comprises a proximity switch 711 and a detection piece 712. The detection piece 712 is provided with a disk 713 at one end for receiving a water jet W and rotatably arranged around a pin 714. The pin 714 is arranged so that the position of the center of gravity of the united structure of the detection piece 712 and the disk 713 is located between the disk 713 and the pin 714. Like the embodiment shown in Fig. 1, the proximity switch 711 is an electromagnetic induction type switch and the detection piece 712 is made of a conductive material. In Fig. 7(a), a water jet W strikes the disk 713, the right side of the detection piece 712 is pressed up, and the detection piece 712 moves away from the proximity switch 711. On the other hand, as shown in Fig. 7(b), when the water jet W does not strike the disk 713, the right side of the detection piece 712 comes down and the left end of the detection piece 712 moves near to the proximity switch 711.
[0042] The receiving portions 502 and 702 shown in Figs. 6(a), 6(b), 7(a) and 7(b), serve the same function as the receiving portion 102 of the position sensor 100 shown in Fig. 1 and are usable for detecting the ends of the metal strip P.
[0043] In the explanation of Fig. 4, it is described that the position sensors 100 are disposed in positions corresponding to the ends of the brush roll 2. However, considering the motion of the detection piece 202 and the control delay, it is preferable that the positions thereof be adjusted by the positioning unit 110 to be slightly inside of the positions exactly corresponding to the ends of the brush roll 2 so that the end of the metal strip P can be detected a little before the metal strip P reaches the end of the brush roll 2. "Positions corresponding to ends of the brush roll" include slightly shifted positions which improve the control or are not disadvantageous.
[0044] The structure shown in Figs. 2(a), 2(b), 6(a) and 6(b), when water jets W do not reach the receiving portions 102 and 502, the conductive parts 203 and 603 move close to the proximity switches 201 and 601. However, it is also possible to detect the ends of the metal strip P by changing the positions of the conductive parts held in the detection pieces 202 and 602 so that the conductive parts 203 and 603 approach to the proximity switches 201 and 601 when water jets W reach the detection pieces 202 and 602, and are disconnected from the proximity switches 201 and 601 when water jets W does not reach them. Likewise, in Fig. 7, the end of the detection piece 712 made of a conductive material moves close to the proximity switch 711 when water jet W does not enter the receiving portion 702. However, it is also possible to arrange it so that the end of the detection piece 712 approaches the proximity switch 711 when water jet W enters the receiving portion 702.
[0045] Regarding the structure of the receiving portion, as long as the proximity switch can detect the displacement of the detection piece, various arrangements are possible including a change in the shape of the detection piece, a shift in the moving direction of the detection piece, an alteration of the positional relationship between the proximity switch and the detection piece, and incorporation of a returning means other than gravity or a spring force.
[0046] In the above explanation, a high-frequency induction type switch is used as the proximity switch. However, it is also possible to use an electrostatic capacity type proximity switch equipped with an L-C resonance circuit which detects an object by means of the change in resonance condition brought about by the change in the capacity of the capacitor induced by an access of a dielectric substance. In this case, the detection piece can be made of only a dielectric substance without necessitating use of a conductive material. As an alternative, various kinds of contact or non-contact type switches can be used which serve as a switch operated by the movement of the detection piece.
[0047] The receiving portion of the detection piece can also be formed by a propeller or an impeller rotated by the incident water and a mechanism for detecting the rotation. Further, the receiving portion of the detection piece can also be formed by a pressure sensor which detects the pressure of the water.
[0048] It is also possible to eject a liquid other than water, or to use a compressed gas such as compressed air, etc.
[0049] It is further understood by those skilled in the art that the foregoing description is a preferred embodiment of the disclosed apparatus and that various changes and modifications may be made in the invention without departing from the spirit and scope thereof.
(Effect of the Invention)
[0050] A brushing apparatus with a reciprocating-roll according to the invention comprises two position sensors having emitting portions for emitting linear flows of water or air and receiving portions for receiving the emitted linear flows of water or air and transmitting the detection signals toward a control unit in line with the presence or absence of the linear flow. The brushing apparatus with a reciprocating-roll of the invention is simply structured such that each of the position sensors described above is mounted on the brush roll stand in positions corresponding to the ends of the brush roll. This simple structure prevents lowered position detection accuracy caused by the adverse effect of metal powder or the cleaning water, and therefore brushing of the metal strip can be conducted in an accurate manner.
1. A brushing apparatus with a reciprocating-roll comprising:
a brushing section provided with
brush rolls (2) for brushing a metal strip (P),
driving devices for rotating the brush rolls, and
a brush roll stand (1) for supporting the brush rolls (2) and the driving devices;
a transfer device for shifting the brush roll stand;
a control unit for controlling the transfer device in a manner that the brush roll stand (1) performs a reciprocating motion in the metal strip (P) width direction; and
position sensors (100;500;700) (1) mounted on the brush roll stand (1) at positions corresponding to both ends of the brush rolls (2) for detecting the side edges of the metal strip (P), each of which position sensors (100;500;700) being provided with:
an emitting portion (101; 501; 701) located in a position corresponding to an end of the brush roll (2) for emitting a linear flow of liquid including water or gas including air from a side above or below the metal strip (P) to the other side, and
a receiving portion (102; 502; 702) located on the opposite side of the metal strip (P) from the emitting portion (101; 501; 701) for receiving the linear flow of liquid including water or gas including air and outputting a detection signal toward the control unit based on the presence or absence of the linear flow.
2. The brushing apparatus with a reciprocating-roll according to Claim 1, wherein the
receiving portion is provided with:
a casing having an aperture in one end thereof
for receiving the incident linear flow; and
a detection piece (202; 602) held in the casing,
wherein the detection piece (202; 602) is movable in the casing in such a manner that the detection piece is located on the aperture side of the casing when the linear flow does not enter thereinto, and the detection piece is moved toward the other end of the casing by the linear flow when the linear flow enters thereinto.3. The brushing apparatus with a reciprocating-roll according to Claim 2, wherein the
detection piece (202; 602) is held so as to vertically move in the casing when struck
by the linear flow.
4. The brushing apparatus with a reciprocating-roll according to Claim 2, wherein the
detection piece (202; 602) is held so as to rotate in the casing when struck by the
linear flow.
5. The brushing apparatus with a reciprocating-roll (102;502;702) according to Claim
2, wherein the receiving portion incorporates a switch for outputting the detection
signal to the control unit based on the movement of the detection piece. (202; 602)