Title of invention: device for opening and closing
Technical field
[0001]
　The present invention relates to an opening / closing device for opening / closing an opening / closing portion of a sliding nozzle device used for controlling the flow rate of molten metal.
Background technology
[0002]
　Two or three refractory plates are used in the sliding nozzle device used for ladle and tundish, and each plate is attached to each plate storage metal frame. When this plate is worn and has reached the end of its life, the sliding nozzle device must be opened to remove the old plate from each plate storage frame and replace it with a new plate. This replacement work must be performed at a high temperature, and if the weight of the plate is heavy, it will be close to 30 kg, which imposes a heavy burden on the operator.
[0003]
　Therefore, in recent years, it has been studied to replace the plate by using a robot arm. For example, the present inventors have disclosed in Patent Document 1 a plate holding device that can be attached to a balancer or a robot arm to hold a plate. When this plate holding device is attached to the robot arm and the plate is replaced, the slide metal frame in which the slide plate is housed, the slide metal frame holding portion for holding the slide metal frame, or the surface pressure of the sliding nozzle device is applied. It is desired from the viewpoint of further reducing the burden on the operator that the robot arm is used to open and close the opening and closing part of the spring box and the like.
[0004]
　By the way, in the steelworks, the sliding nozzle device is attached to the bottom of the molten steel pot such as a ladle or a tundish, so when removing the plate after use, the molten steel pot is laid down sideways on the bottom side of the molten steel pot. The plate attached to the sliding nozzle device must be removed from. At this time, the molten steel pan is tilted sideways by the operation of the crane, but since the crane is operated by a person, the position where the molten steel pan is tilted changes every time, for example, by several centimeters.
[0005]
　Therefore, in order to perform the opening / closing operation of the opening / closing portion of the sliding nozzle device described above by the position control of the robot arm, the position of the sliding nozzle device must be accurately measured every time. In recent years, in the position measurement of an object when using a robot arm, a method of correcting the position coordinates by photographing the object with a camera and performing image processing is generally used. However, regarding the sludging nozzle device, it has been found that in this image processing, although the measurement accuracy in the vertical and horizontal directions is at a practical level, there is a problem that the measurement accuracy in the front-rear direction (distance) deteriorates.
[0006]
　This is because the image is taken while the temperature of the sliding nozzle device is decreasing immediately after being used at a high temperature, and the size of the image reference portion of the sliding nozzle device changes with each image due to thermal expansion. This is because an error in the position coordinates of (distance) is likely to occur. Further, unevenness, scratches, or foreign matter adhere to the photographing reference portion during use, which also causes an error due to image processing.
[0007]
　If a measurement error occurs in the distance between the sliding nozzle device and the robot arm, the opening / closing part of the sliding nozzle device cannot be opened / closed correctly, for example, if the slide metal frame cannot be opened to a predetermined position, the following When the plate is taken out by the robot arm in the above step, the slide metal frame is pushed and moved, which causes a problem that the robot arm cannot grip the plate. Further, if the slide metal frame is not completely closed, there is a problem that the surface pressure load, which is the next step, cannot be applied.
[0008]
　In this way, the sludging nozzle device is used under extremely harsh conditions in which it receives radiant heat from molten steel of 1500 ° C. or higher, holds a plate through which high-temperature molten steel passes, and is further exposed to molten steel splash and dust. Therefore, it has been found that the conventional position measurement method has a problem that the measurement accuracy of the distance is deteriorated.
Prior art literature
Patent documents
[0009]
Patent Document 1: International Publication No. 2018/0744424
Outline of the invention
Problems to be solved by the invention
[0010]
　An object to be solved by the present invention is to provide an opening / closing device capable of reliably opening / closing an opening / closing portion of a sliding nozzle device to a predetermined position.
Means to solve problems
[0011]
　According to the present invention, the following opening / closing device is provided.
1. 1.
　An opening / closing device for opening / closing the opening / closing part of the
　sliding nozzle device. A hand tip that engages with the opening / closing part of the sliding nozzle device and a force sensor that detects the force received by the hand tip are attached to the robot arm. A device for opening and closing.
2. 2. 3.
　The opening / closing device according to 1 above, wherein the hand tip is loosely fitted and engaged with the opening / closing portion with a horizontal gap with respect to the opening / closing portion of the sliding nozzle device
.
　The opening / closing device according to 1 or 2 above, wherein the hand tip is detachably held by a plate holding device capable of holding a plate for a sliding nozzle device.
4.
　When the plate holding device holds a plurality of holding portions for holding the tip portion of the hand, an expansion / contraction means for expanding / contracting the interval between the plurality of holding portions, and the tip portion of the hand by the plurality of holding portions, the hand The opening / closing device according to any one of 1 to 3 above, which has a pressing portion for pushing the tip portion.
5.
　It has a control unit that controls the operation of the robot arm, and the control unit
　moves the tip of the hand toward the opening / closing part of the sliding nozzle device by controlling the operation of the robot arm, and the tip of the hand moves to the opening / closing part of the sliding nozzle device. The parts are engaged, and the
　tip of the hand is moved to move the opening / closing part under the condition that the absolute value of the force detected by the force sensor is equal to or less than a predetermined threshold value.
　The opening / closing device according to any one of 1 to 4 above, wherein the movement of the tip of the hand is terminated when the absolute value of the force detected by the force sensor reaches a predetermined threshold value.
Effect of the invention
[0012]
　According to the present invention, the opening / closing portion of the sliding nozzle device can be reliably opened / closed to a predetermined position.
A brief description of the drawing
[0013]
FIG. 1 is a side view of a main part of an opening / closing device according to an embodiment of the present invention.
FIG. 2 is a plan view of a hand tip portion in the opening / closing device shown in FIG.
FIG. 3 is a perspective view of the tip of the hand shown in FIG.
FIG. 4 is a side view of the plate holding device in the opening / closing device shown in FIG.
FIG. 5 is an overall configuration diagram of an opening / closing device according to an embodiment of the present invention.
FIG. 6 is an operation explanatory view of the opening / closing device shown in FIG.
[Fig. 7] Same as above.
[Fig. 8] Same as above.
Mode for carrying out the invention
[0014]
　As shown in FIG. 1, the opening / closing device 1 according to an embodiment of the present invention includes a hand tip 2, a plate holding device 101 that detachably holds the hand tip 2, and a hand tip of the plate holding device 101. It has a force sensor 10 attached to the side opposite to the portion 2, and these are provided on the robot arm 15 as shown in FIG. 5, for example.
[0015]
　As shown in FIGS. 2 and 3, the hand tip portion 2 includes a ring 21 as an engaging portion, a holding rod 22 for holding the ring 21, and a base plate 23 in which the holding rod 22 is fixed to the central portion thereof. It is composed of and. The base plate 23 is a rectangular metal plate, and two protrusions 24 are provided on the surface opposite to the ring 21.
[0016]
　As the plate holding device 101, the one disclosed in Patent Document 1 is used, and the hand tip portion 2 of the opening / closing device 1 and the plate for the sliding nozzle device according to the embodiment of the present invention are detachably held. be able to.
[0017]
　As shown in FIG. 4, in the plate holding device 101 of Patent Document 1, a force sensor 10 is provided on the side opposite to the pressing portion 9 of the parallel hand 3 as an expansion / contraction means. That is, the plate holding device 101 is provided on the front portion of the parallel hand 3 as the scaling means, the pair (two) holding portions 4 provided on the parallel claws 31 of the parallel hand 3, and the main body portion 32 of the parallel hand 3. It has a pressing portion 9 and a force sensor 10 provided on the side opposite to the pressing portion 9 of the parallel hand 3. Further, each of the tip portions on both sides of the holding portion 4 has two engaging grooves 41.
[0018]
　The scaling means is not limited to the parallel hand 3, and for example, a parallel chuck can be used, and a hydraulic cylinder, an air cylinder, or the like can also be manufactured. Further, the expansion / contraction means is not necessarily limited to a configuration in which the pair of holding portions 4 are expanded / contracted while remaining parallel. It is also possible to expand or contract the distance between the tips of the portions.
[0019]
　As shown in FIG. 1, the plate holding device 101 holds the four corners of the base plate 23 of the hand tip portion 2 by the holding portion 4, and at the same time brings the pressing portion 9 into contact with the protrusion 24 of the base plate 23. As a result, the hand tip portion 2 can be reliably held without wobbling.
[0020]
　As the pressing portion 9, seven bolts 93 penetrate the seven through holes of the holding plate 91 and the seven coil springs 94, respectively, and are fixed to the substrate 95. The board 95 is attached to the main body 32 of the parallel hand 3. The pressing plate 92 is fixed to the holding plate 91 with a gap, and the holding plate 91 and the pressing plate 92 are integrated. Then, the pressing plate 92 can move to the substrate 95 side to bend the coil spring 94. At this time, by providing a gap between the through hole of the holding plate 91 and the bolt 93, the pressing plate 92 can move even in an inclined state. The position of the pressing plate 92 is set to a position where the coil spring 94 bends when the base plate 23 of the hand tip 2 is held by the holding portion 4 (engagement groove 41), and as a result, the hand tip 2 The base plate 23 is in a state of being pressed against the inner wall surface of the engaging groove 41 on the side opposite to the pressing portion 9.
[0021]
　The force sensor 10 is bolted to the flange portion 102 on the side opposite to the pressing portion 9 of the main body portion 32 of the parallel hand 3. That is, the force sensor 10 is a force sensor that detects the force received by the holding portion 4 and / or the pressing portion 9 from the hand tip portion 2. As the force sensor that detects the force in this way, a force sensor that is also called a force sensor and is generally used for a robot arm or the like can be used. In this embodiment, a 6-axis force sensor is used as the force sensor 10.
[0022]
　Next, with reference to FIG. 5, the overall configuration and the usage state of the opening / closing device according to the embodiment of the present invention will be described. In FIG. 5 and FIGS. 6 to 8 described later, the configuration of the plate holding device 101 including the force sensor 10 is shown in an appropriately simplified manner.
[0023]
　In FIG. 5, the ladle 11 immediately after the casting is finished is laid down sideways on the ladle receiving portion 13 installed on the floor 12. A sliding nozzle device 14 is attached to the bottom 111 of the ladle, and the sliding direction is substantially vertical in the state of FIG.
[0024]
　On the other hand, the base end of the robot arm 15 is fixed to a pedestal 18 for the robot arm installed on the floor 12, and the flange portion of the force sensor 10 of the plate holding device 101 is attached to the tip of the robot arm 15 with bolts. Has been done. Further, the plate holding device 101 holds the hand tip portion 2. At this time, the force sensor 10 and the tip of the robot arm 15 are arranged in series so that their central axes coincide with each other. The force sensor 10 can also be provided on the robot arm 15 side independently of the plate holding device 101. Also in this case, the force sensor 10 and the tip of the robot arm 15 are arranged in series so that the central axes coincide with each other.
　The robot arm 15 is a 6-axis vertical articulated robot arm, and the posture and position of the hand tip 2 attached to the tip of the robot arm 15 can be freely moved.
[0025]
　A three-dimensional sensor 16 having a camera 16a and a laser irradiator 16b is attached to the tip of the robot arm 15. The image taken by the camera 16a is input to the image processing device, and the three-dimensional position coordinates are corrected by the image processing method. By inputting this coordinate information to the control unit 17, the robot arm 15 can move the plate holding device 101 to the opening / closing part of the sliding nozzle device 14. On the other hand, the information of the force sensor 10 is always input to the control unit 17. Then, the control unit 17 controls the operation of the hand tip portion 2 via the robot arm 15 based on the information of the force sensor 10 and the like.
[0026]
　Next, a method of opening the slide metal frame holding portion 143, which is one of the opening / closing portions of the sliding nozzle device 14 attached to the bottom 111 of the ladle 11 after casting, will be described with reference to FIGS. 6 to 8. To do.
[0027]
　First, in FIG. 6, the slide metal frame holding portion 143 of the sliding nozzle device 14 is irradiated with a laser from the laser irradiator 16b, photographed by the camera 16a, and image-processed to obtain the reference position of the slide metal frame holding portion. The deviation is calculated to correct the three-dimensional position coordinates of the slide metal frame holding portion 143. By inputting the three-dimensional position coordinates of the corrected slide metal frame holding unit 143 to the control unit 17 (see FIG. 5; the same applies hereinafter), the robot arm 15 operates and the tip of the hand attached to the robot arm 15 operates. The part 2 is moved to the position shown in FIG.
　In the present embodiment, the slide metal frame holding portion 143 is provided with an engaging rod 145 as an engaged portion for engaging with the hand tip portion 2. The ring 21 at the tip of the hand can be loosely fitted and engaged with the engaging rod 145 with a gap.
　That is, the above-mentioned position in FIG. 6 is a state in which the ring 21 of the hand tip portion 2 is engaged with the engaging rod 145 of the slide metal frame holding portion 143. By loosely fitting and engaging the engaging rod 145 and the ring 21 with a gap in the horizontal direction in this way, some errors occur in the three-dimensional position coordinates of the slide metal frame holding portion 143 described above. However, the engagement rod 145 and the ring 21 can be engaged with each other. In the present embodiment, the outer diameter of the engaging rod 145 is 12 mm, the inner diameter of the ring 21 is 40 mm, and there is a gap of 14 mm on one side in the horizontal direction. This gap can be determined according to the measurement accuracy of the position measuring device such as the three-dimensional sensor 16 described above, and can be, for example, 5 mm to 20 mm on one side.
[0028]
　From the state of FIG. 6, the hand tip portion 2 starts moving in the direction of opening the slide metal frame holding portion 143 by the operation control of the robot arm 15 by the control unit 17. At this time, the hand tip 2 receives a force in the pulling direction, and this force is detected by the force sensor 10. In this embodiment, this force in the tensile direction is detected as a negative value. Then, in the present embodiment, the hand tip portion 2 is moved under the condition that the absolute value of the force in the pulling direction is equal to or less than a predetermined threshold value to open the slide metal frame holding portion 143.
[0029]
　Here, since the sliding nozzle device is used to control the flow rate of molten steel at a high temperature, the opening / closing portion such as the slide metal frame holding portion 143 may be seized, or the molten steel or slag may stick to the opening / closing portion. It may require a great deal of force to open or it may be difficult to open. In such a case, if the robot arm 15 is forcibly driven, the hand tip 2, the plate holding device 101, the robot arm 15 itself, or the like may be damaged. In order to prevent such damage, the hand tip portion 2 is moved under the condition that the absolute value of the force detected by the force sensor 10 is equal to or less than a predetermined threshold value.
[0030]
　In order to detect the case where the ring 21 of the hand tip 2 is not engaged with the engaging rod 145 of the slide metal frame holding portion 143, the lower limit of the absolute value of the force detected by the force sensor 10 is set. You can also decide. That is, when the absolute value of the force detected by the force sensor 10 when the hand tip 2 is moved is smaller than a predetermined value (the lower limit), the ring 21 of the hand tip 2 is the slide metal frame holding portion. It can be determined that the engagement rod 145 of 143 cannot be engaged. Based on this, in the present embodiment, the movement of the hand tip portion 2 may be performed under the condition that the absolute value of the force detected by the force sensor 10 is within a predetermined range (above the lower limit value or less than the predetermined threshold value). it can.
[0031]
　When the slide metal frame holding portion 143 is opened, the state shown in FIG. 7 is obtained, and when the slide metal frame holding portion 143 is fully opened, the state shown in FIG. 8 is obtained. The state of FIG. 8 is a state in which the slide metal frame holding portion 143 cannot be opened any more, and the absolute value of the force detected by the force sensor 10 reaches a predetermined threshold value. In the present embodiment, the movement of the hand tip 2 ends when the absolute value of the force detected by the force sensor 10 reaches a predetermined threshold value.
[0032]
　Here, the three-dimensional position coordinates of the slide metal frame holding portion 143 are measured by the three-dimensional sensor 16, but an error may occur in these position coordinates for the reason described above. Therefore, when the robot arm 15 is driven by position control, the slide metal frame holding portion 143 may not be opened to a predetermined position due to this error. Then, the operation of removing the plate by the robot arm 15 in the next step. Will cause a problem. Alternatively, when the hand tip 2 moves to further open the slide metal frame holding portion 143 even though the slide metal frame holding portion 143 is opened to a predetermined position, the hand tip 2, the plate holding device 101, the robot arm 15, etc. May be damaged. In order to prevent these, the movement of the hand tip portion 2 is terminated when the absolute value of the force detected by the force sensor 10 reaches a predetermined threshold value.
[0033]
　The slide metal frame holding portions 143 are located on both sides of the slide metal frame 142, respectively, but in the present embodiment, the two slide metal frame holding portions 143 are connected by a link, and one slide metal frame holding portion 143 is connected. When you open and close the other, the other also opens and closes in tandem.
[0034]
　Next, the operation of closing the slide metal frame holding portion 143 will be described. Since this operation is the opposite of the operation of opening the slide metal frame holding portion 143, it will be described from the state of FIG.
[0035]
　In FIG. 8, the hand tip 2 is moved by the robot arm 15 based on the position coordinate information of the slide metal frame holding unit 143 from the control unit 17, and the hand tip is attached to the engaging rod 145 of the slide metal frame holding unit 143. The ring 21 of the part 2 is engaged.
[0036]
　After that, the hand tip portion 2 is moved in the direction in which the slide metal frame holding portion 143 closes. At this time, the hand tip 2 receives a force in the pulling direction, and this force is detected by the force sensor 10. In the present embodiment, the force in the tensile direction is detected as a negative value as described above. Then, in the present embodiment, the hand tip portion 2 is moved and the slide metal frame holding portion 143 is closed under the condition that the absolute value of the force in the pulling direction is equal to or less than a predetermined threshold value. When the slide metal frame holding portion 143 is closed, the state shown in FIG. 7 is obtained, and when the slide metal frame holding portion 143 is completely closed, the state shown in FIG. 6 is obtained. The state of FIG. 6 is a state in which the slide metal frame holding portion 143 cannot be closed any more, and the absolute value of the force detected by the force sensor 10 reaches a predetermined threshold value. In the present embodiment, the movement of the hand tip 2 ends when the absolute value of the force detected by the force sensor 10 reaches a predetermined threshold value.
[0037]
　In the embodiment described above, the engaging rod 145 is provided as the engaged portion of the sliding nozzle device and the ring 21 is provided as the engaging portion of the tip of the hand, but conversely, as the engaged portion of the sliding nozzle device. A ring may be provided and an engaging rod may be provided as an engaging portion at the tip of the hand. Further, the shapes of the engaged portion and the engaging portion are not limited to the rod and the ring. In short, the shape may be such that the engaged portion of the sliding nozzle device and the engaging portion of the tip of the hand are engaged (engaged) with each other.
Code description
[0038]
　1 Opening and closing device
　101 Plate holding device
　102 Flange part
　2 Hand tip part
　　21 Ring
　　22 Holding rod
　　23 Base plate
　　24 Protrusion
　3 Parallel hand (expansion / contraction means)
　　31 Parallel claw
　　32 Main body part
　4 Holding part
　　41 Engagement groove
　9 Pressing part
　　91 plate
　　92 pressing plate
　　93 bolt
　　94 spring
　　95 substrate
　10 force sensor
　11 ladle
　　111 ladle bottom
　12 floor
　13 ladle receiving
　14 sliding nozzle device
　　141 fixed metal frame
　　142 slide metal frame
　　143 slide metal frame holding section
　　145 engaging rod
　15 Robot arm
　16 Solid sensor
　　16a Camera
　　16b Laser irradiator
　17 Control unit
　18 Stand for robot arm
The scope of the claims
[Claim 1]
　An opening / closing device for opening / closing the opening / closing part of the
　sliding nozzle device. A hand tip that engages with the opening / closing part of the sliding nozzle device and a force sensor that detects the force received by the hand tip are attached to the robot arm. A device for opening and closing.
[Claim 2]
　The opening / closing device according to claim 1, wherein the hand tip is loosely fitted and engaged with the opening / closing part with a horizontal gap with respect to the opening / closing part of the sliding nozzle device.
[Claim 3]
　The opening / closing device according to claim 1 or 2, wherein the tip of the hand is detachably held by a plate holding device capable of holding a plate for the sliding nozzle device.
[Claim 4]
　When the plate holding device holds a plurality of holding portions for holding the tip portion of the hand, a scaling means for expanding or contracting the distance between the plurality of holding portions, and the tip portion of the hand by the plurality of holding portions, the hand The opening / closing device according to any one of claims 1 to 3, further comprising a pressing portion for pushing the tip portion.
[Claim 5]
　It has a control unit that controls the operation of the robot arm, and the control unit
　moves the tip of the hand toward the opening / closing part of the sliding nozzle device by controlling the operation of the robot arm, and the tip of the hand moves to the opening / closing part of the sliding nozzle device. The parts are engaged, the
　tip of the hand is moved to move the opening / closing part under the condition that the absolute value of the force detected by the force sensor is equal to or less than a predetermined threshold
　value, and the absolute value of the force detected by the force sensor is predetermined. The opening / closing device according to any one of claims 1 to 4, wherein the movement of the tip of the hand is terminated when the threshold value is reached.