Specification
Title of invention: Surface-following nozzle, moving object surface observing device, and moving object surface observing method
Technical field
[0001]
　The present invention relates to a surface following nozzle, a moving object surface observing device, and a moving object surface observing method.
Background technology
[0002]
　In order to manufacture a rolled steel sheet having a good surface and shape in a steel sheet rolling mill, the surface condition of the rolling roll is grasped, and the profile, that is, the radius distribution in the roll axis direction is accurately grasped. Therefore, it is important to be able to determine the replacement timing of the rolling rolls and to be able to control by feeding back to the rolling conditions and cooling conditions.
[0003]
　For example, the rolling roll during hot rolling, the material temperature to be rolled is a high temperature of about 1000 ℃, with the passage of rolling time, even if the rolling roll is cooled, it is subjected to severe thermal influence, The surface becomes rough and rough. When rolling is performed with a rolling roll having such rough skin, the scale formed on the convex portion is pressed by the rolling roll and is pushed into the rolled material, and the scale is scratched on the surface of the steel sheet and scale flaws occur. For this reason, the rolling amount up to roll exchange is decided in advance, and rolls are systematically changed.However, this method requires setting the rolling amount on the safe side. Was becoming.
[0004]
　In a rolling roll during hot rolling, when the rolled material is stretched with a high load, the roll expands in the radial direction due to heat, or the roll diameter decreases only in a portion through which the rolled material has passed due to wear. If the diameter variation in the roll axis direction, that is, the profile cannot be accurately grasped, it becomes a factor that causes a thickness defect or a shape defect of the rolled material. Therefore, conventionally, the expansion and wear amount due to heat were estimated by a computer from data such as the actual condition of the rolled material and the amount of roll cooling water, and the rolling roll profile was obtained, but this method is not accurate, so the shape There was a defect.
[0005]
　As a measure against such a problem, a roll surface observation method in which a roll surface is photographed by a camera, or a roll radius is calculated by measuring a distance from a predetermined position to a roll outer peripheral surface with an ultrasonic distance meter, and the calculation is performed. A method of measuring the roll profile based on the value has been proposed.
[0006]
　The rolling roll surface observing apparatus described in Patent Document 1 supplies water to the rolling roll from a nozzle, forms a water column between the rolling roll and the nozzle, and photographs the roll surface with a camera through the formed water column. ..
[0007]
　The roll profile measuring method described in Patent Document 2 generates a water column between a probe incorporating an ultrasonic distance meter and a rolling roll, and pulsed ultrasonic waves emitted from the distance meter travel back and forth between the probe and the roll surface. The distance is obtained from the distance meter, and the distance meter is scanned along the guide rail in the roll axis direction to measure the roll profile.
[0008]
　The surface inspection apparatus described in Patent Document 3 includes an inspection apparatus including a light source and a light receiving unit, a cylindrical nozzle provided along the axis of a light beam emitted from the light source, and a movable nozzle provided in the cylindrical nozzle. And a nozzle. Water passing through the movable nozzle from the cylindrical nozzle pushes the movable nozzle toward the rolling roll, and the gap between the movable nozzle and the rolling roll is adjusted by the flow rate of water.
Prior art documents
Patent literature
[0009]
Patent Document 1: Japanese Patent Laid-Open No. 2009-85843
Patent Document 2: Japanese Patent Laid-Open No. 7-229733
Patent Document 3: Japanese Patent Publication No. 2004-517324
Summary of the invention
Problems to be Solved by the Invention
[0010]
　In any of the methods described in Patent Documents 1 to 3, in order to secure a measurement route under a large amount of cooling water, it is necessary to form a water column between the rolling roll and the observation camera or range finder. .. In such a water column, air bubbles are generated inside due to the interference between the roll and the cooling water. The bubbles may interfere with observation or may cause noise in the ultrasonic range finder and interfere with measurement. Further, a high-precision optical sensor such as a laser rangefinder cannot be applied to the measurement using water as a medium, which is likely to cause uneven refractive index due to flow rate or temperature.
[0011]
　The present invention provides a surface following nozzle capable of removing water in the vicinity of a nozzle while following changes in the shape and distance of a moving object, a moving object surface observing device, and a moving object surface observing method. The purpose is to
Means for solving the problem
[0012]
　The surface-following nozzle according to the present invention is a nozzle that injects gas from the tip, a partition portion that closes the base end of the nozzle, and is provided behind the nozzle via the partition portion, and in the axial direction of the nozzle. It includes an elastic body that expands and contracts along the nozzle, and the elastic body has an elastic body that applies a force to the nozzle in the forward direction.
[0013]
　An apparatus for observing a moving object surface according to the present invention comprises the surface following nozzle, an environment box provided behind the surface following nozzle, and an optical observation unit housed in the environment box, An observation optical path is provided from the optical observation section to the tip of the nozzle.
[0014]
　The method for observing the surface of a moving object according to the present invention includes a nozzle that injects gas from the tip, a partition that closes the base end of the nozzle, and a shaft of the nozzle that is provided behind the nozzle via the partition. A stretchable portion that stretches along a direction, wherein the stretchable portion includes a surface-following nozzle including an elastic body that applies a forward force to the nozzle, and an environmental box provided behind the surface-following nozzle. The movement is performed by using an optical observation unit housed in the environment box, and an observation device for the surface of a moving object provided with an observation light path from the optical observation unit to the tip of the nozzle. The method comprises the steps of monitoring an object, determining the timing of exchanging the moving object, or controlling the usage conditions of the moving object.
Effect of the invention
[0015]
　According to the surface following nozzle of the present invention, it is possible to follow the change in the shape and the change in the distance of the moving object due to the expansion and contraction of the expansion and contraction portion. By injecting gas from the nozzle at a predetermined flow rate, water near the tip of the nozzle can be removed. Therefore, by using the surface following nozzle, the surface of the moving object can be observed without being affected by water.
Brief description of the drawings
[0016]
FIG. 1 is a schematic diagram showing a hot rolling mill to which an observation device according to this embodiment is applied.
FIG. 2 is a cross-sectional view showing an observation device according to the present embodiment.
FIG. 3 is a partial cross-sectional view of a nozzle according to the present embodiment.
FIG. 4 is a graph showing the relationship between the gap between the tip of the nozzle and the surface of a moving object and the back pressure of the nozzle.
FIG. 5 is a schematic diagram showing an apparatus used in experiment (1).
FIG. 6 is a graph showing the results of experiment (1), FIG. 6A is a relationship between the gap and the flow rate, and FIG. 6B is a view illustrating the relationship between the nozzle back pressure and the flow rate.
FIG. 7 is a graph obtained by extracting an experimental result at a flow rate of 1000 L/min, FIG. 7A is a diagram showing a relationship between a pushing amount and a nozzle back pressure, and FIG. 7B is a diagram showing a relationship between a gap and a nozzle back pressure.
FIG. 8 is a schematic diagram showing an apparatus used in the experiment (2).
FIG. 9 is a graph showing the results of experiment (2), where FIG. 9A shows the result of a push amount of 0 mm, FIG. 9B shows the result of a push amount of 6 mm, and FIG. 9C shows the result of a push amount of 12 mm.
MODE FOR CARRYING OUT THE INVENTION
[0017]
　Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
(Overall configuration) The
　hot rolling mill 10 shown in FIG. 1 includes a heating furnace 12 and a rolling mill 13 on the downstream side of the heating furnace 12. The heating furnace 12 heats the rolled material 18 by blowing a flame onto the rolled material 18 as a moving object carried in from the upstream side. The rolled material 18 is heated in the heating furnace 12 and then conveyed to the downstream side, whereupon the rolled material is transferred to the rolling process by the rolling mill 13.
[0019]
　The rolling mill 13 allows the conveyed rolling material 18 to pass between a pair of cylindrical hot rolling rolls (hereinafter referred to as rolling rolls) 14 and roll it to a predetermined thickness. The actual hot rolling mill 10 includes a plurality of rolling mills 13. The rolling mill 13 is provided with a cooling water supply unit 16. The cooling water supply unit 16 is arranged upstream of the rolling mill 13 and supplies cooling water to the rolling roll 14 from the upstream side.
[0020]
　An observation device 20 is arranged closer to the rolled material 18 than the cooling water supply unit 16. The observation device 20 observes the surface of the rolling roll 14 immediately before coming into contact with the surface of the rolled material 18.
[0021]
　As shown in FIG. 2, the observation device 20 includes a surface following nozzle 22, an environment box 24, and an optical observation unit 26. The surface-following nozzle 22 has a nozzle 28, an expansion / contraction portion 30, and a partition portion 32. In this specification, the front end (rolling roll side) of the surface following nozzle 22 is the front, and the base end (environment box side) is the rear.
[0022]
　The nozzle 28 injects gas from the nozzle tip toward the surface of the rolling roll 14 to remove the cooling water near the nozzle tip. In the case of the present embodiment, the nozzle 28 has an inner nozzle 34 and an outer nozzle 36 arranged outside the inner nozzle 34. The inner nozzle 34 is a tubular member, the inner cavity of which is narrowed toward the distal end, and the flange portion 35 protruding outward is provided at the base end of the inner nozzle 34. The outer nozzle 36 is a tubular member having an inner diameter larger than that of the inner nozzle 34, and has an edge portion 37 protruding inwardly provided at the tip. The inner nozzle 34 can be retracted into the outer nozzle 36 and can be advanced to the outer nozzle 36 as long as the collar portion 35 comes into contact with the edge portion 37.
[0023]
　The tip of the nozzle has a flat surface 29 facing the surface of the rolling roll 14. The flat surface 29 is a surface parallel to the direction orthogonal to the axial direction of the nozzle 28. In particular, in the case of the rolling roll 14 that is a cylindrical rotating body, even if there is a deviation between the normal line passing through the center of the measurement point on the roll surface and the nozzle center axis (observation optical path L), the flat surface 29 at the tip of the nozzle It is necessary to secure the area of ​​the flat part so that the roll surfaces face each other. Since the inner cavity of the inner nozzle 34 is narrowed toward the tip, a pressure loss occurs and the inner nozzle 34 advances toward the outer nozzle 36. If the outer diameter of the tip of the nozzle is too large, the weight increases and it becomes difficult to perform the expansion and contraction operation. Therefore, the outer diameter of the flat surface 29 is preferably about 2 to 4 times the nozzle diameter d (FIG. 3). The term “orthogonal” is not limited to the case of being strictly orthogonal, but also includes the case of being slightly deviated.
[0024]
　Nozzle 28 need not have inner nozzle 34 and outer nozzle 36 formed of the same material. At least the inner nozzle 34 is formed of a material softer than the rolling roll 14. The inner nozzle 34 is preferably made of a material having a small coefficient of friction, for example, a material containing a solid lubricant. Specifically, the inner nozzle 34 is preferably formed of a material in which a phenol resin is mixed with a solid lubricant that improves lubrication performance and glass fiber as reinforcing fiber. As the solid lubricant, graphite, molybdenum disulfide and the like can be used. By forming the inner nozzle 34 with such a soft material, when the tip of the inner nozzle 34 comes into contact with the rolling roll 14, the rolling roll 14 is not damaged, which is preferable.
[0025]
　The outer nozzle 36 is provided with a first gas introduction port 38 and a second gas introduction port 40. The first gas introduction port 38 leads into the outer nozzle 36. The gas supplied to the first gas introduction port 38 is ejected from the tip of the inner nozzle 34 to the outside through the inside of the outer nozzle 36. The back pressure of the nozzle is increased by the gas, so that the inner nozzle 34 advances toward the outer nozzle 36. The second gas introduction port 40 communicates between the flange portion 35 and the edge portion 37. The gas supplied to the second gas introduction port 40 retracts the inner nozzle 34, which has advanced from the outer nozzle 36, into the outer nozzle 36.
[0026]
　The expansion/contraction part 30 is provided behind the nozzle 28 via the partition part 32. The partition portion 32 closes the base end of the nozzle 28. The partition section 32 is kept airtight so that the gas supplied to the nozzle 28 does not flow to the expansion/contraction section 30. An optical window 48 is fitted in the partition portion 32. The optical window 48 is a glass or resin plate capable of transmitting the light emitted from the optical observation unit 26 and the light reflected from the rolling roll 14.
[0027]
　The expandable part 30 has an inner cylinder part 44, an outer cylinder part 46, and a bellows spring 42 as an elastic body. The tip of the inner cylinder portion 44 is connected to the partition portion 32, and the other end is inserted into the tip of the outer cylinder portion 46. The base end of the outer cylinder portion 46 is connected to the front end side surface of the environment box 24. The base end side of the inner cylinder portion 44 can enter and exit the outer cylinder portion 46. The inner cylinder portion 44 and the outer cylinder portion 46 are arranged in the bellows spring 42. The bellows spring 42 has one end in contact with the surface of the partition portion 32 and the other end in contact with the front end side surface of the environment box 24, and applies a forward force to the nozzle 28 via the partition portion 32. The telescopic portion 30 expands and contracts along the axial direction of the nozzle 28 as the inner cylinder portion 44 moves in and out of the outer cylinder portion 46 as the bellows spring 42 expands and contracts.
[0028]
　The environment box 24 has an opening 25 on the front end side surface, and an optical observation unit 26 is housed therein. The base end of the outer tubular portion 46 is connected so as to surround the opening 25. The observation optical path L is formed in a straight line from the opening 25 to the tip of the inner nozzle 34. As the optical observation unit 26, an illumination and a two-dimensional camera, an optical range finder, a laser Doppler speedometer, a radiation thermometer, and the like can be used.
[0029]
　When an illumination and a two-dimensional camera are used as the optical observation unit 26, the surface of the rolling roll 14 is illuminated and an image of the surface is captured by the two-dimensional camera. The roughened state of the surface of the rolling roll 14 can be grasped based on the captured image, and the timing of roll replacement and surface maintenance can be accurately determined.
[0030]
　When an optical rangefinder is used as the optical observation unit 26, the surface of the rolling roll 14 is irradiated with laser light, and the time until the scattered light from the rolling roll 14 is received and the position are measured, The distance to the surface of the roll 14 is measured.
[0031]
　When a laser Doppler velocimeter is used as the optical observation unit 26, the surface of the rolling roll 14 is irradiated with laser light, and the frequency of the scattered light from the rolling roll 14 shifts by the Doppler effect. 14 The moving speed of the surface is measured. The distance to the surface of the rolling roll 14 measured by the optical observation unit 26, or the moving speed of the surface of the rolling roll 14 is output to a computing device (not shown). The arithmetic unit calculates the fluctuation of the outer diameter due to the expansion and wear of the rolling roll 14 based on the distance to the roll surface and the moving speed of the roll surface. Based on the calculated variation of the outer diameter due to expansion and wear of the rolling roll 14, it is possible to accurately determine the timing of roll replacement and surface maintenance.
[0032]
　When a radiation thermometer is used as the optical observation unit 26, the temperature of the surface of the rolling roll 14 is measured by measuring the intensity of infrared rays emitted from the rolling roll 14. Based on the measured temperature, it is possible to identify the cause of the thermal expansion that changes the roll profile and the surface temperature rise that causes the surface of the rolling roll 14 to become rough.
[0033]
　The gap G between the nozzle tip and the surface of the rolling roll 14 will be described with reference to FIG. In order to inject the gas and remove the cooling water W near the nozzle tip, it is necessary to inject a gas having a momentum exceeding the momentum of the cooling water W. In the case of the present embodiment, by controlling the size of the gap G within a predetermined range, the flow velocity of the gas to be injected is increased and a gas having a momentum exceeding the momentum of the cooling water W is obtained.
[0034]
　The conditional expression for increasing the flow velocity of the gas to be injected by narrowing the gap G will be derived below. Assuming that the nozzle diameter is d [m], the nozzle discharge area SN [m 2 ] can be expressed by the following equation (6).
　　S N =π(d/2) 2 (6)
[0035]
　Further, assuming that the gap is G [m], the area SG [m 2 ] of the gap G at the tip of the nozzle is as shown in the following equation (7). The area S G of the gap G at the nozzle tip refers to the area of ​​the opening portion of the gap G between the nozzle tip and the surface of the rolling roll 14 that is orthogonal to the gas flow direction.
　　S G =πdG (7)
[0036]
　In order to increase the flow velocity of the gas to be injected by controlling the size of the gap G within a predetermined range, the area S G of the gap G needs to be smaller than the nozzle discharge area S N. It is necessary to meet the condition of.
　　S G p W
　　ρ A V A 2 S>ρ W V 2 S
　　(ρ W /ρ A ) 1/2 >V A /V (12)
[0041]
　On the other hand, since the pressure loss increases as the gap G becomes narrower, the lower limit of the selectable gap G is determined by the maximum pressure of the supplied gas. Generally, a compressor is used to supply the compressed gas, and the maximum pressure is 0.7 MPa, but the flow rate can be dealt with by selecting the size of the compressor. If the gas flow rate Q [m 3 /s] is the area S G [m 2 ] of the gap G at the nozzle tip and the nozzle back pressure P [Pa], then according to Bernoulli's theorem, the following equation (13) holds. ..
　　Q=S G (2/ρ A ) 1/2 P 1/2 (13) When the
　flow rate is constant, the gap G is inversely proportional to the square root of the nozzle back pressure P.
　　Since Q=πdG(2/ρ A ) 1/2 P 1/2
　　V A =Q/S G ,
　　V(ρ W /ρ is obtained from the equations (12) and (13). A ) 1/2 > (2 / ρ A ) 1/2 P 1/2
　　P> (ρ W V 2 ) / 2 Since the above equation must be satisfied even when the
　maximum speed V max , the minimum acceptable minimum. The pressure P min can be expressed as follows.
　P min = [rho W V max 2 /2 where,
V max = 15 m / s, [rho W = 997Kg / m 3 when, P min is = 0.11 MPa. That is, it is necessary to narrow the gap G so that the nozzle back pressure becomes 0.11 MPa or more.
[0042]
　Assuming that the spring constant k [N/m] of the bellows spring 42, the contraction amount x [m], the nozzle back pressure P [Pa], and the nozzle discharge area S N [m 2 ] are the following equations from the hook law and force balance (14) is established.
　　kx = PS N · · · (14)
　, where the maximum pressure P which can be supplied max contraction amount x at max
　　When, kx max = P max S N
　and the minimum pressure P min during contraction amount x min When ,
　　Kx min =P min S N From
　these two expressions,
　　k(x max −x min )=(P max −P Min ) S N
becomes.
[0043]
Assuming that the 　required follow-up distance change amount is x r , in order to secure the momentum and the gap G in which the cooling water can be eliminated within this x r range, it is necessary to push back the bellows spring 42 by the nozzle back pressure and contract it. , X r <(x max −x min ), the spring constant k needs to satisfy the following expression (15).
　　kx r <(P max −P min )S N
　　k<(P max −P min )S N /x r (15)
[0044]
　FIG. 4 shows the relationship between the gap G and the nozzle back pressure obtained by the experiment. In the experiment, the size of the gap G between the tip of the nozzle 28 and the surface of the rolling roll 14 was changed so that the bellows spring 42 was fixed and did not expand and contract, and the relationship with the nozzle back pressure was investigated. The nozzle diameter d was φ15 mm, and the flow rate Q was 1000 L / min (constant). The gap G was set to zero when the tip of the nozzle was in contact with the surface of the rolling roll 14. The nozzle back pressure was measured by measuring the pressure inside the nozzle with a pressure gauge. It was confirmed that the gap G of 0.3 mm or more can be maintained in the range of the nozzle back pressure change of 0.5 MPa (0.1 to 0.6 MPa).
[0045]
　If the nozzle diameter is φ15 mm and the maximum pressure is 0.5 MPa and the shrinkage amount is 17 mm, k = 5.19 N / mm. That is, by selecting a bellows spring having a spring constant k of 5.19 N/mm or less, even if the position of the rolling roll 14 changes by 17 mm in a gas pressure change width of 0.5 MPa, it can follow. The amount of expansion and contraction of the surface following nozzle that matches the position of the rolling roll 14 is called the amount of change in the following distance. In this case, the following distance change amount is 17 mm.
[0046]
(Operation and Effect) The operation and effect of the
　observation device 20 will be described. First, the inner nozzle 34 is pulled out from the outer nozzle 36, and the tip of the inner nozzle 34 is brought into contact with the rolling roll 14 in the stopped state. At this time, the collar portion 35 of the nozzle 28 is not in contact with the edge portion 37 and is not completely extended.
[0047]
　Next, the compressed gas is supplied to the first gas introduction port 38. The gas is controlled so that the flow rate is constant. The gas supplied to the first gas inlet 38 increases the pressure inside the nozzle 28 (nozzle back pressure). A force in the rear direction is generated in the partition portion 32 due to the back pressure of the nozzle. When the force becomes larger than the forward force of the bellows spring 42, the expansion/contraction part 30 contracts. When the expandable/contractible part 30 contracts, the outer nozzle 36 moves rearward integrally with the expandable part 30 because the inner cavity of the inner nozzle 34 is constricted toward the tip, and the flange part 35 contacts the edge part 37. Until then, the inner nozzle 34 advances from the outer nozzle 36. In this way, the nozzle 28 is completely extended.
[0048]
　As the nozzle back pressure further increases, the expansion/contraction part 30 further contracts, and a gap G is formed between the nozzle tip and the rolling roll 14. The compressed gas inside the nozzle is jetted to the outside from the nozzle tip through the gap G. In fact, the expansion of the gap G moderates the rise of the nozzle back pressure, and the force of pushing the partition portion 32 backward by the nozzle back pressure and the force of the bellows spring 42 pushing the nozzle 28 forward are balanced. At some time, the rise of the nozzle back pressure and the contraction of the expansion/contraction part 30 stop. The gap G at this time is called an initial gap.
[0049]
　The inner nozzle 34 is held in a state of being advanced from the outer nozzle 36 by the injected gas. Since the base end of the nozzle 28 is closed by the partition part 32 and is partitioned from the expansion/contraction part 30, the inner nozzle 34 maintains the protruding state even when the expansion/contraction part 30 expands/contracts, and the volume inside the nozzle 28 is Holds constant. As shown in FIG. 4, since the nozzle back pressure and the gap G have a correlation, the size of the gap G can be estimated by measuring the nozzle back pressure when the flow rate is constant.
[0050]
　Then, the operation of the rolling mill 13 is started. That is, the rolling roll 14 is rotated and the cooling water W is supplied to the rolling roll 14. The cooling water W adheres to the surface of the rolling roll 14 and rotates integrally with the rolling roll 14.
[0051]
　In the vicinity of the nozzle tip of the observation device 20, the cooling water W is removed by the gas ejected from the nozzle tip. The cooling water W flows on the surface of the rolling roll 14 so as to avoid the tip of the nozzle. The light emitted from the optical observation unit 26 travels along the observation optical path L. Since the cooling water W near the tip of the nozzle is removed, the light emitted from the optical observation unit 26 reaches the surface of the rolling roll 14 without being blocked by the cooling water W. Similarly, the light reflected from the rolling roll 14 also reaches the optical observation unit 26. Therefore, the observation device 20 can observe the surface of the rolling roll 14 by the optical observation unit 26 without being affected by the cooling water W.
[0052]
　In addition, the optical observation part cannot be applied to the conventional observation apparatus using a water column. That is, in the conventional observation device using a water column, bubbles are generated inside due to the interference between the roll and the cooling water. The bubbles may interfere with observation or may cause noise in the ultrasonic range finder and interfere with measurement. In addition, since water is likely to cause unevenness in the refractive index due to the flow rate and temperature, the accuracy is significantly reduced when an optical observation unit such as a laser rangefinder is used. Therefore, in the conventional observation apparatus using the water column, the surface of the rolling roll cannot be observed by applying the optical observation section.
[0053]
　When the rolling roll 14 that is rolling the rolled material 18 expands due to the heat of the rolled material 18, the gap G becomes smaller. When the gap G becomes smaller, the nozzle back pressure increases (FIG. 4). The expansion/contraction portion 30 contracts until the bellows spring 42 pushes the partition portion 32 forward and the force of pushing the partition portion 32 backward by the increased nozzle back pressure balances. The expansion/contraction part 30 contracts so that the gap G returns to the same level as the initial gap, and gas having a predetermined flow velocity is ejected from the tip of the nozzle.
[0054]
　When the rolling roll 14 that is rolling the rolled material 18 contracts in the radial direction due to wear, the gap G becomes large. As the gap G increases, the nozzle back pressure decreases (FIG. 4). The telescopic portion 30 extends until the force by which the bellows spring 42 pushes the partition portion 32 forward is balanced with the force pushing the partition portion 32 backward by the reduced nozzle back pressure. By the expansion/contraction part 30 extending, the gap G returns to the same level as the initial gap, and gas having a predetermined flow velocity is jetted from the nozzle tip.
[0055]
　As described above, the surface-following nozzle 22 controls the gap G to approach the initial gap by expanding and contracting the expansion/contraction portion 30 in accordance with the position of the surface of the rolling roll 14 that has changed due to the expansion and contraction of the rolling roll 14. .. Therefore, even if the position of the rolling roll 14 changes, the observation device 20 can remove the cooling water W near the tip of the nozzle by injecting gas at a predetermined flow rate, and is not affected by the cooling water W. In addition, the surface of the rolling roll 14 can be observed. Since the expansion / contraction portion 30 is provided between the partition portion 32 and the environment box 24, the environment box 24 does not move even if the surface following nozzle 22 expands / contracts following the rolling roll 14. The surface-following nozzle 22 follows the change in the shape of the rolling roll 14 and the change in the distance due to the balance between the force generated by the nozzle back pressure acting on the partition section 32 and the force generated by the bellows spring 42, so that the gas flow rate is controlled. You don't have to.
[0056]
　When replacing the rolling roll 14, the rotation of the rolling roll 14, the supply of the cooling water W, and the supply of the gas to the first gas introduction port 38 are stopped. Then, the compressed gas is supplied between the flange portion 35 and the edge portion 37 via the second gas inlet 40. The gas causes the inner nozzle 34 to retract into the outer nozzle 36, causing the nozzle 28 to contract. By contracting the nozzle 28, the rolling roll 14 can be easily replaced. The radius of the rolling roll 14 may change due to the replacement of the rolling roll 14, but if the amount of change in radius is within the amount of change in the following distance of the following nozzle, it follows the roll surface and the optical observation unit 26 The field of view can be secured.
[0057]
(Example)
　The effect of the surface following nozzle 22 was verified by actually using the experimental apparatus shown in FIG. A pipe provided with a flow meter 50, a valve 54, and a pressure gauge 52 is connected to the first gas inlet 38. Compressed air is supplied to the pipe as a gas from a compressed gas supply device (not shown). The nozzle diameter was φ15 mm. The bellows spring 42 is made of SUS (spring constant k: 5 N/mm, 14 peaks, natural length: 67 mm, expansion/contraction amount: 17 mm or more). The flow meter 50 measures the flow rate of compressed air passing through the pipe between the compressed gas supply device and the nozzle 28. The pressure gauge 52 measures the nozzle back pressure. A simulated roll 14 having a diameter of 400 mm was used as a moving object. The gap G was measured from an image obtained by macro photography between the nozzle tip and the simulated roll 14. In the experimental device shown in this figure, when the observation device 20 is moved toward the simulated roll 14 with the nozzle 28 being completely extended, the position where the tip of the nozzle contacts the surface of the simulated roll 14 is set to 0 mm. The change in the gap G and the flow rate were measured. The result is shown in FIG. In FIG. 6A, the horizontal axis represents the gap (mm) and the vertical axis represents the flow rate (L/min). In FIG. 6B, the horizontal axis represents the nozzle back pressure (MPa) and the vertical axis represents the flow rate (L/min). In each pushing amount, the gap G and the flow rate have a substantially proportional relationship, and the larger the pushing amount, the more difficult the gap G is to open. On the other hand, it was found that the nozzle back pressure gradually rises as the flow rate increases, and increases as the pushing amount increases.
[0058]
　FIG. 7A shows the relationship between the amount of pushing and the nozzle back pressure when the flow rate Q is 1000 L/min, and FIG. 7B shows the relationship between the nozzle back pressure and the gap G. It was confirmed that the bellows used this time can maintain a gap G of 0.3 mm even with a pushing amount of 15 mm by a nozzle back pressure of 0.5 MPa, almost as designed. The pushing amount and the nozzle back pressure match the relational expression (the above expression (13)) when the bellows is not used. Therefore, it was found that the pushing amount can be estimated by measuring the nozzle back pressure. Further, there is a correlation between the nozzle back pressure and the size of the gap G, and the size of the gap G can be estimated from the nozzle back pressure. The maximum gap is 0.8 mm when the pushing amount is 0 mm. The velocity V of the moving object capable of removing the cooling water at this time is 15.9 m / m according to equation (12) (ρ A : 1.293 kg / m 3 (using compressed air), ρ W : 997 kg / m 3 ). s. That is, under the above conditions, the cooling water can be eliminated if the rotation speed of the roll is 15.9 m/s or less.
[0059]
　Next, the effect of the observation device 20 was verified using the experimental device shown in FIG. A disk 14 was used as a moving object. Compressed air having a flow rate of 1000 L/min (constant) was supplied to the first gas inlet 38. With the nozzle 28 extended, the state in which the tip of the nozzle was in contact with the surface of the disk 14 was set to 0 mm, and the visibility was confirmed when the observation device 20 was moved toward the disk 14 by 6 mm or 12 mm. The surface speed of the disk 14 was 95, 300, and 730 mpm (1.6 m/s, 5 m/s, and 12.2 m/s, respectively). When water is supplied to the disk 14 (with water) and when water is not supplied (without water), the moving object surface is irradiated with light by the optical observation unit 26 housed in the environment box 24, The scattered light from was received and the signal intensity of the scattered light was measured. The result is shown in FIG. In FIG. 9, the horizontal axis represents the speed (mpm) and the vertical axis represents the signal intensity (dB). FIG. 9A shows the result of the pushing amount of 0 mm, FIG. 9B shows the pushing amount of 6 mm, and FIG. 9C shows the pushing amount of 12 mm. There was no difference in signal intensity between with and without water. Therefore, the water is removed by the surface following nozzle 22, and the observation device 20 can observe the surface of the moving object without being affected by the water.
[0060]
(Modification) The
　present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the gist of the present invention.
[0061]
　Although the case where the present invention is applied to a rolling roll as a moving object has been described, the present invention is not limited to this and can be applied to an axisymmetric object such as a pipe or a machine part. Further, not limited to the axisymmetric object, even a planar moving object such as a steel plate being cooled can be applied as long as the range of distance variation to the surface is within the following distance change of the following nozzle, It is possible to perform surface observation, temperature measurement, length measurement, etc. of the target moving object. Although the case where the present invention is applied to a hot rolling roll as a moving object has been described, the present invention is not limited to this and may be applied to a cold rolling roll.
[0062]
　Although the case where the bellows spring 42 is used as the elastic body has been described, the present invention is not limited to this, and for example, a coil spring or rubber may be used.
Explanation of symbols
[0063]
14 Rolling roll (moving object)
20 Observation device
22 Surface tracking nozzle
24 Environmental box
26 Optical observation unit
28 Nozzle
29 Flat surface
30 Telescopic part
32 Partition
34 Inner nozzle
36 Outer nozzle
42 Bellows spring (elastic body)
48 Optical window
50 Flow rate a total of
52 pressure gauge
The scope of the claims
[Claim 1]
　A nozzle for injecting the gas from the tip,
　and a partition portion for closing the proximal end of the nozzle,
　provided through the partition portion in the rear of the nozzle, and a stretchable part that expands and contracts along the axial direction of the nozzle
provided with The
　telescopic portion is a
surface-following nozzle having an elastic body that applies a force to the nozzle in the forward direction .
[Claim 2]
　The spring constant of the elastic body is k [N / m], the required follow-up distance change amount is xr [m], the maximum pressure of the gas that can be supplied is P max [Pa], and the minimum pressure of the acceptable gas is P. min [Pa], nozzle discharge area S N [m 2 ], maximum velocity of cooling water around the nozzle tip is V max , and cooling water density is ρ W [kg/m 3 ] The spring constant k of the
　body satisfies the following equations (1) and (2), and the contraction amount x[m] of the elastic body is in the range of x min to x max represented by the following equations (3) and (4). The surface-following nozzle according to claim 1.
　k<(P max −P min )S N /x r ... (1)
　P min =ρ WV max 2
　/2 · · · (2) x min = P 　min S N / k · · · (3) x max = P max S N / k · · · (4)
[Claim 3]
　Wherein a flow meter is provided the gas is connected to the pipe for supplying to the nozzle nozzle,
　and a pressure gauge for measuring the pressure in the nozzle
comprises a
surface tracking nozzle according to claim 1 or 2.
[Claim 4]
　The surface-following nozzle according to any one of claims 1 to 3, wherein the elastic body is a bellows.
[Claim 5]
　The nozzle has an inner nozzle and an outer nozzle provided coaxially with the inner nozzle, and the inner nozzle projects from the outer nozzle by the pressure of the gas to be jetted. 5. The surface following nozzle according to any one of 4 to 4.
[Claim 6]
　The surface following nozzle according to claim 5, wherein the material of the inner nozzle contains a phenol resin, a solid lubricant, and a reinforcing fiber.
[Claim 7]
　The surface follower according to any one of claims 1 to 6, wherein the nozzle tip has a flat surface parallel to a direction orthogonal to the axial direction, and the outer diameter of the nozzle tip is 2 to 4 times the inner diameter. nozzle.
[Claim 8]
　The surface-following nozzle according to any one of claims 1 to 7, wherein the lumen of the nozzle is narrowed toward the tip.
[Claim 9]
　The surface-following nozzle according to claim 1, wherein the partition portion has an optical window.
[Claim 10]
　And surface tracking nozzle according to claim 9,
　and environmental box provided behind the surface following the nozzle,
　and an optical observation section housed within the environment box,
provided with,
　said nozzle from said optical observation unit An observation device for the surface of a moving object that is provided with an observation optical path across the tip.
[Claim 11]
　It has a nozzle that injects gas from the tip,
　a partitioning part that closes the base end of the
　nozzle, and a stretchable part that
is provided behind the nozzle through the partitioning part and that expands and contracts in the axial direction of the nozzle. The expandable portion includes a surface-following nozzle including an elastic body that applies a force to the nozzle in a forward direction,
an environment box provided behind the surface-following nozzle,
　and an optical type housed in the environment box. an observation unit,
comprising a viewing device, the moving object surface observation light path across the nozzle tip from the optical observation unit is provided
comprising the steps of: monitoring the moving object using a
　replacing the moving object
Observing the surface of the moving object , or deciding the timing to perform, or controlling the use condition of the moving object.
[Claim 12]
　The nozzle diameter is d [m], the gas density is ρ A [kg/m 3 ], the density of cooling water is ρ W [kg/m 3 ], the velocity of the moving object is V [m/s], and jetting is performed. 12. The moving object surface according to claim 11, wherein the following formula (5) is satisfied , where Q [m 3 /s] is the flow rate of the gas and G [m] is the gap between the moving object surface and the nozzle tip. Observation method.
　(Ρ A / ρ W ) 1/2 Q / (πdV)> G ... (5)
[Claim 13]
　Based on the flow rate of the gas flowing through the pipe supplying the gas to the nozzle and the nozzle back pressure, at least one of the pushing amount of the elastic body and the size of the gap between the nozzle tip and the surface of the moving object. The method for observing the surface of a moving object according to claim 11 or 12, wherein one is estimated.