JP4298008B2 - Pressure vessel retightening device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is a pressure vessel such as a beer barrel.IncreaseThe present invention relates to a clamping device.
[0002]
[Prior art]
Pressure vessels such as beer barrels are collected from the market and used repeatedly. Before these pressure vessels are reused, the performance of the vessel is checked to see if the lid is loose and the sealing performance of the lid valve has not deteriorated.
[0003]
In the current barrel beer filling line, a residual pressure inspection device and a lid tightening device are installed before and after the outer washing machine and the inner washing machine in order to check the performance of the pressure vessel. In the residual pressure inspection device, the residual pressure of the pressure vessel returned from the market is taken out and monitored by a sensor, and the residual pressure is inspected. Search the market for lids that have been opened once and that there may be foreign objects (such as cigarette butts) in the pressure vessel. Pressure vessels that do not generate pressure during the residual pressure inspection are rejected and re-inspected because there is a risk of any of the above abnormalities.
[0004]
In the retightening device, the engaging portion (rotating body) fitted to the lid is rotated by using a rotational driving force such as a nut runner or a motor, and a torque limiter, a powder clutch, or the like that can control the rotational torque. Retightened. The lid that is loose when recovered from the market is retightened to a specified strength in the retightening process.
[0005]
[Problems to be solved by the invention]
However, when it was on the market, the store's server sometimes vented the gas because it thought that the beer and juice in the pressure vessel (keg) remained empty. Such a pressure vessel is rejected at the time of residual pressure inspection because the residual pressure is low even if it is not opened. The rejected pressure vessel is re-inspected by the operator, but the residual pressure is low due to abnormalities such as packing, or the residual pressure is low because the lid is opened in the market, or the gas is simply vented. The cause is not clear. Therefore, the re-inspection work was troublesome. For this reason, it has been desired that the factor when the pressure vessel is determined to be abnormal can be roughly grasped.
[0006]
In addition, there is a possibility that some of the pressure vessels in the market where the lid is once opened and hand-tightened have a high residual pressure due to carbon dioxide gas generated from the remaining liquid of the carbonated beverage. . In this case, the residual pressure test may be overlooked and determined to be normal.
[0007]
The present invention has been made to solve the above-mentioned problems, and its purpose is to enable a pressure vessel whose lid may have been opened once in the market to be found by a method other than a residual pressure test.IncreaseThe object is to provide a clamping device.
[0008]
[Means for Solving the Problems]
[0009]
  Claim1In the invention described in the above, the engaging portion that engages and rotates with the lid, the rotation drive means that applies a rotational force to the engagement portion, the control means that controls the rotation of the rotation drive means, and the engagement portion Detecting means for detecting the presence or absence of rotation, and the control means is weaker than that at the time of retightening first in the loosening direction to the lid engaged by the engaging portion before retightening the lid.A lid that has a high torque and is hand-tightened is opened and cannot be opened if the lid is tightened with a specified force.In the process of controlling the rotation driving means so as to apply torque and applying a set torque in the loosening direction to the lid, if the rotation of the lid is not detected by the detection means, it is determined that the lid is normal. If a rotation is detected, there is provided determination means for determining that there is an abnormality.
[0010]
  Claim2In the invention described in claim1In the invention described in claim 2, after the end of the looseness confirmation step of applying a set torque in the loosening direction to the lid to check whether the lid rotates, the control means engages with the lid. In the retightening process of controlling the rotation driving means so as to apply a tightening torque in the retightening direction, the determination means is configured to perform the engagement by the detection means when the cover should be completed. The gist is that it is determined to be abnormal when rotation of the part is detected.
[0011]
  Claim3In the invention described in claim1Or claim2The control means controls the torque of the rotation driving means so as to rotate the engagement portion at a constant rotational speed, and the detection means detects the rotation torque of the engagement portion in the rotation direction. The gist is to detect the rotation stop state of the engaging portion when the set torque is reached.
[0012]
  Claim4In the invention described in claim1Or claim2The control means controls the rotation driving means for applying a constant torque to the engagement portion, and the detection means detects a rotation speed of the engagement portion, The gist is to detect the rotation stop state of the engagement portion when the rotation speed of the engagement portion becomes zero.
[0014]
(Function)
  Therefore,Claim1According to the invention described in the above, before retightening the lid, the engaging portion engaged with the lid is weaker than when tightening in the loosening direction of the lid.A lid that is torque and is only hand-tightened is opened and cannot be opened if the lid is tightened with a specified force.Torque is applied. If the lid does not loosen in this process and the rotation of the lid is not detected by the detection means, the judgment means judges that the pressure vessel is normal. If the lid is loosened during this process and the rotation of the lid is detected by the detection means, the determination means determines that the pressure vessel is abnormal.
[0015]
  Claim2According to the invention described in the above, after the looseness confirmation step of applying the set torque in the loosening direction to the lid and confirming whether the lid is loose or not is finished, the tightening torque is applied to the engaging portion that engages the lid in the tightening direction. Is granted. In the retightening process, when the rotation of the engaging portion is detected by the detecting means at the time when the retightening of the lid is supposed to be completed, the determining means determines that the pressure vessel is abnormal.
[0016]
  Claim3According to the invention described in (2), the torque of the rotation driving means is controlled so as to rotate the engagement portion at a constant rotation speed. When the lid does not loosen, the torque applied to the engaging portion reaches the set torque. Therefore, when the detection means does not detect that the torque has reached the set torque, it is determined that the pressure vessel is abnormal.
[0017]
Also, in the tightening process, when tightening torque is applied to the engagement part engaged with the lid, if the pressure vessel has an abnormality in the screw or packing of the lid, the tightening of the lid should be completed Even at this point, it is not detected by the detection means that the torque has reached the tightening torque. At this time, it is determined that the pressure vessel is abnormal.
[0018]
  Claim4According to the invention described in (3), the rotation driving means is controlled so as to rotate the engaging portion with a constant torque. Since the lid that has been hand-tightened loosens when a constant torque is applied, if the rotational speed of the engaging portion detected by the detecting means is not zero, the lid may be opened in the market. It is determined that the pressure vessel is abnormal.
[0019]
Further, in the tightening process, if the pressure vessel has no abnormality in the lid, packing, etc., the lid is tightened by applying a constant torque to the lid and rotating the lid in the tightening direction. When the tightening of the lid is finished, the rotation speed of the engaging portion becomes zero. Even when the tightening should be completed, if the detection means detects that the rotational speed of the engaging portion is not zero, it is determined that the pressure vessel is abnormal.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment embodying the present invention will be described below with reference to FIGS. 6 and 7 are a plan sectional view and a side sectional view, respectively, of the tightening device. The retightening device 1 includes a head unit 2, a carry-in conveyor 3, an inspection line 4, a carry-out conveyor 5, and a defective product discharge line 6.
Consists of
[0021]
A cutting device 7 is disposed at the exit of the carry-in conveyor 3. The cutting device 7 opens and closes the tips of the two arms 8 to cut out one pressure vessel (in this example, a beer barrel) 9 in a row on the carry-in conveyor 3 one by one, and four pressure vessels 9 Carry in with a certain interval. On the conveyor 4a of the inspection line 4, four inspection positions are set in the longitudinal direction, and four gripping devices 10 for gripping the pressure vessel 9 are disposed at the four inspection positions. The gripping device 10 includes four arms (8 in total) for gripping the pressure vessel 9 from both sides.
[0022]
As shown in FIG. 7, the arm 8 of the cutting device 7 is driven to open and close by driving an air cylinder (none of which is shown) with the respective rotary shafts 12 connected via a link mechanism. In the arm 11 of the gripping device 10, gears 14 attached to the lower ends of the four rotating shafts 13 mesh with each other on the left and right sides (vertical direction in FIG. 6), and each of the left and right rotating shafts 13 is linked to each other (see FIG. The eight arms 11 are opened and closed synchronously by driving the air cylinder 15. In FIG. 7, only two of the four air cylinders 15 are shown. In FIG. 6, for convenience of explanation, a state in which the arm 11 grips the pressure vessel 9 and an open state in which the pressure vessel 9 is not gripped are depicted on one drawing. Actually, the arms 11 of the four gripping devices 10 are driven synchronously.
[0023]
A support bar 17 is guided by two linear guides 18 and can be moved up and down on a gate-shaped frame 16 surrounding the inspection line 4. The support bar 17 moves up and down along the linear guide 18 when the two screw shafts 20 and 21 screwed to the two nut bodies 19 rotate forward and backward based on the drive of the motor 22. The two screw shafts 20 and 21 are operatively connected by a chain 23, and the rotational force of the driving-side screw shaft 20 is transmitted to the driven-side screw shaft 21 through the chain 23.
[0024]
Four head units 2 are disposed on the support bar 17 at positions corresponding to the positions immediately above the respective inspection positions. The pressure vessel 9 to be inspected has a plurality of types according to its capacity, and the height of the four head units 2 is adjusted according to the height of the pressure vessel by raising and lowering the support bar 17.
[0025]
As shown in FIG. 6, a defective product discharge conveyor 6 is connected to the entrance portion of the carry-out conveyor 5 so as to be orthogonal. An extrusion device 24 is disposed at a position facing the defective product discharge conveyor 6 across the carry-out conveyor 5. The extruding device 24 includes an extruding bar 26 that is driven back and forth by an air cylinder 25, and the pressure vessel 9 determined to be defective in the inspection line 4 is pushed out by the extruding bar 26 onto the defective product discharge conveyor 6 and rejected. The pressure vessel 9 determined to be a non-defective product in the inspection line 4 flows straight from the inspection line 4 through the carry-out conveyor 5 and is sent to the next process.
[0026]
The pressure vessel (beer barrel in this example) 9 targeted by the retightening device 1 includes a lid 27 as shown in FIG. 4 in this embodiment. The lid 27 has a valve structure and is screwed to the mouth portion 9a of the pressure vessel 9 so that the upper surface thereof is substantially flush with the upper surface of the mouth portion 9a. There is a recess in the center of the lid 27, and two claw portions 28 are formed at a position of 180 ° on the inner peripheral surface side of the upper end. When the annular projection 29 at the center of the bottom of the dent is pushed from above, the internal pressure of the pressure vessel 9 is released.
[0027]
  FIG.FIG. 2 shows a side sectional view of the head unit 2. The head unit 2 is moved along the linear rail 31 by engaging the movable block 32 provided on the side of the linear rail 31 fixed to the support plate 30 extending downward from the support bar 17. It is arranged so that it can be raised and lowered. An air cylinder 33 is disposed on the support plate 30, and the tip end of the rod 33 a is connected to a support portion 32 a extending from the movable block 32.
[0028]
A cylindrical body 36 is rotatably supported inside a cylindrical housing 34 supported by the movable block 32 via a pair of upper and lower bearings 35. A drive shaft 37a of a servo motor 37 serving as a rotational drive means is connected to a speed reducer 38, and a cylindrical body 36 is fixed to a ring 36a fixed to be rotatable integrally with an output shaft of the speed reducer 38 so as to be integrally rotatable. A rotating shaft 39 is inserted into the cylindrical body 36 by spline coupling. The rotating shaft 39 is slidable in the axial direction and integrally rotatable with respect to the cylindrical body 36.
[0029]
A housing 42 of the head 41 is connected to the lower end of the rotating shaft 39 via a coupling 40. The coupling 40 is a cruciform joint and is composed of three parts: a fixed piece 43, an intermediate connecting member 44, and a movable piece 45.
[0030]
Two extending portions that extend downward from both ends of the fixed piece 43 (both ends in the direction orthogonal to the paper surface in the figure), and 2 that extend upward from both ends of the movable piece 45 (both left and right ends in the figure). The three parts 43 to 45 are connected to each other by inserting a pin 46 protruding in a cross shape from the intermediate connecting member 44 into each hole with the one extending portion. The movable piece 43 can be displaced in the X / Y horizontal plane along the axial direction of the pin 46 with respect to the fixed piece 45 and can be relatively rotated about the X / Y axis around the pin 46.
[0031]
A substantially cylindrical skirt portion 48 is fixed to the lower surface of the ring 47 fixed to the lower end of the cylindrical body 36 so as to be rotatable integrally with the rotary shaft 39. The lower portion of the skirt portion 48 expands in a trumpet shape, and the head 41 is in a state where the slanted upper surface is in contact with the slanted inner peripheral surface of the upper member 42a of the housing 42. 48 is engaged in a state of being capable of relative displacement.
[0032]
The fixed piece 43 of the coupling 40 is connected to the rotary shaft 39 so as to be integrally rotatable. The head 41 is biased downward by a biasing force of a spring (coil spring) 49 disposed between the ring 47 and the fixed piece 43. Therefore, when the head 41 receives a force from below when the head unit 2 is lowered, the rotary shaft 39 slides upward in the cylindrical body 36 against the biasing force of the spring 49, so that the head 41 moves upward. It can be evacuated.
[0033]
An annular pressing portion 50 is fixed to the lower surface of the housing 42, and a tapered surface 50a capable of guiding the lid 27 of the pressure vessel 9 is formed on the inner peripheral surface of the lower portion made of resin. An engaging portion 51 is formed on the lower surface of the housing 42 so as to protrude downward so as to be positioned on the same axis as the rotation shaft 39. Concave portions 51 a are formed on the lower end surface of the engaging portion 51 at four positions where the two claw portions 28 of the lid 27 can be engaged.
[0034]
As shown in FIG. 3, a servo motor (hereinafter simply referred to as a motor) 37 is connected to a controller 53 (for example, a programmable controller) as a determination means via a servo driver 52 as a detection means. The servo driver 52 can select torque limit control or torque control setting as a method of applying a constant rotational torque to the lid 27. The servo driver inputs control information such as voltage, current value, and rotation speed when controlling the motor as a signal from the motor 37, and the motor 37 is controlled by a preset control method based on the feedback signal information. Rotation control. The rotational speed is detected by a rotary encoder assembled to the motor 37. The motor 37 generates a torque substantially proportional to the current under a constant voltage. The servo driver 52 and the controller 53 constitute a control means.
[0035]
As shown in FIG. 1, in this embodiment, a looseness confirmation step of rotating the lid in the loosening direction (opening direction) is added before the tightening step. In the loosening confirmation step, the lid 27 that is only hand-tightened is opened, and the normal lid 27 that is tightened with a specified torque is rotated in a loosening direction with a torque that is not opened. In this example, as shown in FIG. 1, the torque in the tightening process is set to 2 kgf · m, whereas the torque in the loosening confirmation process is set to 0.5 kgf · m. The pressure vessel 9 whose lid 27 is opened in the loosening confirmation process is rejected as being likely to have been opened in the market.
[0036]
In the present embodiment, torque limit control is employed as a control method of the motor 37 for applying a prescribed torque (0.5 or 2 kgf · m) to the lid 27. The torque limit control is a current value control that compensates the current value so that the motor 37 can be maintained at a constant rotational speed. When the current value reaches a preset torque limit value, the current beyond that is cut. It is a control method. The servo driver 52 drives the motor 37 in the reverse direction when the reverse rotation command is input from the controller 53, and drives the motor in the normal direction when the normal rotation command is input. When the current value reaches the torque limit value and the current is cut, a cut signal is input from the servo driver 52 to the controller 53. When the controller 53 receives the cut signal, it issues a stop command for stopping the driving of the motor 37. For this reason, the motor 37 can be stopped when the specified torque is applied to the lid 27.
[0037]
As shown in FIG. 2, the setting data of the servo driver 52 is set to the constant rotational speed N1 and the torque limit value It1 in the loosening confirmation process, and to the constant rotational speed N2 and the torque limit value It2 in the tightening process. Is set. The torque limit value It1 is a current value that can generate a torque of 0.5 kgf · m, and the torque limit value It2 is a current value that can generate a torque of 2 kgf · m (see FIG. 1).
[0038]
As shown in FIG. 3, the controller 53 includes a memory 54 and a timer 55. The memory 54 stores program data for controlling the looseness confirmation process and the tightening process. In the program data, a setting is made to first issue a reverse rotation command to execute the loosening confirmation process, and then issue a normal rotation command to execute the retightening process. In the loosening confirmation process, when a cut signal is input or when a predetermined time t1 has elapsed from the reverse rotation command without input of the cut signal, a stop command is issued to the servo driver 52. In the retightening process, when the cut signal is input or when the predetermined time t2 has elapsed from the forward rotation command without the input of the cut signal, the servo driver 52 is instructed to stop. The predetermined times t1 and t2 are measured by the timer 55.
[0039]
Since four concave portions 51a are formed at the 90 ° position at the tip of the engaging portion 51, the positional relationship between the claw portion 28 of the lid 27 and the concave portion 51a does not match when the head unit 2 is lowered. Even if the concave portion 51a of the portion 51 does not fit into the claw portion 28, the engaging portion 51 engages with the lid 27 until it rotates 90 °. As described above, the set time t1 is set to a time that allows a little margin for the time required for the engagement portion 51 to be fitted into the lid 27. For example, a setting time t1 of 1 to 2 seconds is sufficient, and in this example, it is set to about 1 second.
[0040]
Further, some beer barrels have a substantially triangular lid, and in the case of such a pressure vessel, the engagement portion of the head unit 2 has three positions of 120 ° that can be engaged with the cut surface of the lid. The nail is formed on. Also in this case, the claw of the engaging portion fits into the lid after 120 ° rotation, so that the set time t1 is sufficient, for example, 1 to 2 seconds. In either case, for example, the time required for the engaging portion to rotate 180 ° may be set to the set time t1.
[0041]
Further, the set time t2 is a time required for the engaging portion 51 to rotate until it engages with the lid 27, and a time required for the rotation only to tighten the lid 27 even if the lid 27 is loosened. The total time is set to a time with some allowance. For example, 1.5 to 3 seconds is sufficient as the set time t2, and is set to about 1.5 seconds in this example.
[0042]
The controller 53 makes a normal determination when a cut signal is input in the looseness confirmation process, and makes an abnormality determination when a predetermined time t1 has elapsed without the input of the cut signal. If the determination result in the loosening confirmation process is abnormal, the next retightening is not performed. In addition, when a cut signal is input in the tightening process, a normal determination is made, and when a predetermined time t2 has passed without a cut signal being input, an abnormality is determined. The pressure vessel 9 that has been determined to be abnormal in the loosening confirmation process or the tightening process is stored in the controller 53 as a rejection target. The pressure vessel 9 determined to be normal in both the loosening confirmation process and the tightening process is sent to the next process.
[0043]
Next, the operation of the retightening device 1 will be described.
The four pressure vessels 9 cut out one by one by the cutting device 7 are gripped and positioned by the arm 11 of each gripping device 10 at each inspection position. Next, the air cylinder 33 is driven, the head unit 2 is lowered, and the pressing portion 50 is pressed against the upper end portion of the pressure vessel 9. In this case, in most cases, the concave portion 51a of the engaging portion 51 does not fit into the claw portion 28 of the lid 27 only once when the head unit 2 is lowered.
[0044]
The controller 53 executes program data stored in the memory 54. First, a reverse rotation command is issued to the servo driver 52. As a result, the motor 37 is driven in reverse and current value control is performed so that the motor 37 is rotated at a constant rotational speed N1. If the pressure vessel 9 is not opened in the market and the lid 27 is tightened with a specified torque, the current value immediately becomes the torque limit value It1 when the engaging portion 51 starts to rotate and engages the lid 27. A cut signal is output immediately after reaching (see FIG. 2). When the cut signal is output, a stop command is issued to the servo driver 52, and the drive of the motor 37 is stopped. In this case, the controller 53 determines that the lid 27 is a normal pressure vessel 9 that has been tightened with a specified torque and has no fear of being opened in the market.
[0045]
On the other hand, the pressure vessel 9 whose lid 27 has been opened even once in the market is 0.5 kgf before the current value reaches the torque limit value It1 after the engaging portion 51 rotates and engages with the lid 27. -The lid 27 is loosened with a torque of less than m. Therefore, as shown in FIG. 2, the engaging portion 51 continues to rotate with a small torque, and the predetermined time t1 elapses without the cut signal being input. When the predetermined time t1 has elapsed, a stop command is issued from the controller 53 to the servo driver 52, and the drive of the motor 37 is stopped. In this case, the controller 53 determines that the lid 27 is an abnormal pressure vessel 9 that may have been opened in the market. If an abnormality is determined, the process does not proceed to the next tightening process.
[0046]
For the pressure vessel 9 determined to be normal in the loosening confirmation process, the process proceeds to the next tightening process. In the retightening process, the controller 53 outputs a forward rotation command to the servo driver 52 when confirming that the motor 37 is stopped. As a result, the motor 37 is driven to rotate forward, and the current value is controlled so that the motor 37 rotates at a constant rotational speed N2.
[0047]
When the engaging portion 51 starts to rotate and engages with the lid 27, a rotational torque is applied to the lid 27 and the lid 27 is tightened. In the case of the pressure vessel 9 with no damage to the screw, packing, etc. of the lid 27, the load increases as the lid 27 is tightened, so that the rotational speed decreases, and the current value increases to compensate for this. Then, when the lid 27 is tightened with a prescribed torque (for example, 2 kgf · m), the current value reaches the torque limit value It2 and a cut signal is output (see FIG. 2). When the cut signal is output, a stop command is issued from the controller 53 to the servo driver 52. In this case, the controller 53 determines that the lid 27 is a normal pressure vessel 9 tightened with a specified torque.
[0048]
On the other hand, if the pressure vessel 9 has an abnormality in the screw or packing of the lid, the engaging portion 51 continues to rotate with a small torque before the current value reaches the torque limit value It2, as shown in FIG. That is, the cut signal is not input even if the predetermined time t2 has elapsed after the engaging portion 51 starts to rotate. When the predetermined time t2 has elapsed, a stop command is issued from the controller 53 to the servo driver 52, and the drive of the motor 37 is stopped. In this case, the controller 53 determines that the pressure vessel 9 has an abnormality in the lid 27, packing, or the like. The determination result is stored in the controller 53.
[0049]
When the loosening confirmation process and the tightening process by the head unit 2 are completed, the head unit 2 is raised and returned to the standby position, and the arm 11 of the gripping device 10 is opened. Then, the conveyor 4a of the inspection line 4 is driven, and the four pressure vessels 9 are carried out of the inspection line 4. The abnormality-determined pressure vessel 9 determined to be rejected in this unloading process is pushed out to the defective product discharge conveyor 6 by the push-out bar 26 of the push-out device 24. On the other hand, the pressure vessel 9 determined to be normal is sent straight from the inspection line 4 to the next process through the carry-out conveyor 5.
[0050]
As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) Since the rotational torque in the loosening direction is once applied to the lid 27 in the tightening stage and it is detected whether or not the lid 27 is loosened at that time, there is a possibility that the lid 27 may be opened in the market. The container 9 can be found by methods other than the residual pressure test. For example, after the lid 27 is hand-tightened, the pressure vessel 9 that is likely to be missed in the residual pressure inspection due to the carbon dioxide gas generated from the remaining liquid of the carbonated beverage can be reliably detected. In addition, since the pressure vessel 9 rejected by the retightening device 1 is roughly understood to be a pressure vessel 9 that may have the lid 27 opened in the market, the work of re-inspection by the worker is not time-consuming. .
[0051]
(2) In the line where the tightening device 1 is installed on the upstream side of the residual pressure inspection device, the pressure vessel 9 with the lid 27 opened in the market can be rejected at the tightening stage. By reducing the number of pressure vessels 9 to be provided, the work load of the residual pressure inspection device can be reduced. Further, since the pressure vessel 9 rejected by the residual pressure inspection device is roughly known to have a high possibility of being caused by an abnormality such as a screw or packing of the lid 27, re-inspection work is easy.
[0052]
(3) Since the tightening device 1 is used and the method of adding the looseness confirmation process before the tightening process is adopted, the time required for raising and lowering the head unit 2 does not increase, and the maximum is about 1 to 2 seconds. In addition, since the number of steps for confirming the loosening in a short time is increased, the work efficiency of the tightening device 1 is not reduced so much.
[0053]
(4) Since the torque limit control is employed and the motor 37 is controlled to rotate at a constant rotational speed, the lid 27 is loose in the loosening confirmation process or the screw of the lid 27 is damaged in the tightening process. Even in the case of the abnormal pressure vessel 9, it is possible to avoid the lid 27 from spinning idly (by high speed rotation).
[0054]
(5) It is torque limit control, and when the rotational torque of the engaging portion 51 reaches the set torque for loosening, it is immediately found that it is normal, and at that point, the loosening confirmation process is terminated and the next tightening is performed. Since the process proceeds, the inspection time that is excessively increased when the normal pressure vessel 9 is inspected is further shorter than the predetermined time t1, for example, a fraction thereof.
[0055]
(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIGS. In this embodiment, the motor control method is different from that of the first embodiment. The structures of the tightening device 1 and the head unit 2 are the same as those in the first embodiment. Therefore, the same portions are denoted by the same reference numerals and the description thereof is omitted, and only different control methods are particularly described. do.
[0056]
The concept for finding a pressure vessel 9 that may have been opened once in the market is based on the concept shown in FIG. 1, and similarly, a loosening confirmation process is performed first and then a tightening process is performed. The torque in the tightening process is set to 2 kgf · m, and the torque in the loosening confirmation process is set to 0.5 kgf · m, which is considerably smaller than the torque in the tightening process.
[0057]
In this embodiment, torque control is adopted as a control method set in the servo driver 52 as a method of applying a constant rotational torque to the lid 27. Torque control is current value control for rotating the motor 37 with a constant rotational torque. The servo driver 52 detects the rotational speed of the motor from the rotational signal input from the rotary encoder assembled to the motor 37. When the rotational speed becomes zero as shown in FIG. Output to the controller 53.
[0058]
As shown in FIG. 9, the data setting for torque control includes the constant current value It1 corresponding to the torque of 0.5 kgf · m in the loosening confirmation process, and the current value of the motor 37 in the tightening process. A constant current value It2 corresponding to a torque of 2 kgf · m is set.
[0059]
The controller 53 stores program data for control in the loosening confirmation process and the tightening process in the memory 54. In the program data, first, a reverse rotation command is issued and a looseness confirmation process is executed. After confirming that the motor 37 is stopped, a forward rotation command is issued and then a retightening process is executed. In the loosening confirmation process, the servo driver 52 is instructed to stop when a zero speed signal is input or when a predetermined time t1 has elapsed from the reverse rotation instruction without the input of the zero speed signal. Further, in the retightening process, when the zero speed signal is input or when a predetermined time t2 has elapsed from the forward rotation command without the input of the zero speed signal, the servo driver 52 is instructed to stop. The predetermined times t1 and t2 are measured by the timer 55.
[0060]
When a zero speed signal is input in the loosening confirmation process, a normal determination is made, and when a predetermined time t1 has passed without inputting the zero speed signal, an abnormality is determined. If an abnormality is determined, it does not proceed to the next tightening process. Further, when a zero speed signal is input in the tightening process, a normal determination is made, and when a predetermined time t2 has passed without inputting the zero speed signal, an abnormality determination is made. The pressure vessel 9 that has been determined to be abnormal in the loosening confirmation process or the tightening process is to be rejected. The pressure vessel 9 determined to be normal in both the loosening confirmation process and the tightening process is sent to the next process.
[0061]
The set times t1 and t2 are set based on the same concept as in the first embodiment. For example, the set time t1 may be set with some allowance for the time required for the engaging portion 51 to rotate 180 °. For example, the set time t1 is in the range of 1 to 2 seconds, and is set to about 1 second in this example. As for the set time t2, the time required for the engagement portion 51 to rotate until it engages with the lid 27, and the time required for the rotation to be tightened even if the lid 27 is loose, The total time is set to a time that allows a little margin. In this example, the set time t2 is, for example, in the range of 1.5 to 3 seconds, and is particularly set to about 1.5 seconds.
[0062]
According to the retightening device 1, the motor 37 is subjected to current value control with a constant rotational torque. First, in the loosening confirmation process, the motor 37 is driven in reverse, and the rotation is controlled at a constant current value It1, that is, a constant torque of 0.5 kgf · m, as shown in FIG. If the pressure vessel 9 is closed with a specified torque, the rotation is stopped when the engaging portion starts to rotate and engages with the lid 27, and a zero speed signal is immediately output to drive the motor 37. Is stopped. In this case, the controller 53 determines that the lid 27 is a normal pressure vessel 9 that is tightened with a specified torque.
[0063]
On the other hand, the pressure vessel 9 whose lid 27 is once opened in the market is loosened with a constant torque of 0.5 kgf · m applied when the engaging portion 51 is engaged with the lid 27, and thus continues to rotate as it is. . Then, when the predetermined time t1 elapses without the output of the zero speed signal, and when the predetermined time t1 elapses, a stop command is issued from the controller 53 to the servo driver 52, and the driving of the motor 37 is stopped. In this case, the controller 53 determines that the lid 27 is an abnormal pressure vessel 9 that may have been opened in the market. If an abnormality is determined, the process does not proceed to the next tightening process.
[0064]
For the pressure vessel 9 determined to be normal in the loosening confirmation process, after the motor 37 is stopped, the process continues to the tightening process. In the retightening process, the motor 37 is driven to rotate in the forward direction, and the rotation is controlled at a constant current value It2, that is, a constant torque of 2 kgf · m, as shown in FIG. When the engaging portion 51 starts to rotate and engages with the lid 27, a rotational torque of 2 kgf · m is applied to the lid 27.
[0065]
If the pressure vessel 9 has no abnormality in the screw, packing, etc. of the lid 27, the rotational speed drops due to a load that increases as the lid 27 is tightened, and the clutch is engaged when tightened with a torque of 2 kgf · m. The rotation of the unit 51 stops and a zero speed signal is output. When the zero speed signal is output, a stop command is issued from the controller 53 to the servo driver 52, and the drive of the motor 37 is stopped. In this case, the controller 53 determines that the lid 27 is a normal pressure vessel 9 that is tightened with a prescribed torque and that there is no abnormality in the screws and packing of the lid 27.
[0066]
On the other hand, if the pressure vessel 9 has an abnormality in the screw or packing of the lid 27, the 2 kgf · m of 2 kgf · m added to the lid 27 when the engaging portion 51 is engaged with the lid 27 as shown in FIG. Due to the torque, the lid 27 continues to rotate, and tightening does not end indefinitely, and the lid 27 continues to rotate. As a result, the predetermined time t2 elapses without the zero speed signal being input, and the driving of the motor 37 is stopped. In this case, the controller 53 determines that the pressure vessel 9 is abnormal in which the screw or packing of the lid 27 is abnormal. The determination result is stored in the controller 53.
[0067]
After the looseness confirmation process and the tightening process by the head unit 2 are finished, the pressure vessel 9 that has been determined to be abnormal is transferred to the defective product discharge conveyor 6 by the extrusion bar 26 of the extrusion device 24 when being unloaded from the inspection line 4. Extruded. On the other hand, the pressure vessel 9 determined to be normal is sent straight from the inspection line 4 to the next process through the carry-out conveyor 5.
[0068]
As described above in detail, according to this embodiment, the effects (1) to (3) described in the first embodiment can be obtained in the same manner. In addition, the following effects can be obtained.
(6) In the torque control, it can be seen that it is normal immediately when it is detected that the rotation speed of the engaging portion 51 is zero after the driving of the motor 37 is started. The inspection time which is excessively increased at the time of the inspection of 9 is further shorter than the predetermined time t1, for example, a fraction thereof.
[0069]
In addition, embodiment is not limited above, You may change as follows.
○ Instead of watching the timer 55 after a predetermined time t1, t2, the rotation amount of the engaging portion 51 (that is, the head 41) is detected based on the signal from the rotary encoder. It may be detected that the predetermined time after the joint portion 51 is fitted, or that the predetermined time at which the tightening of the lid 27 should be completed is reached in the tightening process. For example, if the cut signal or the zero speed signal is not input before the predetermined time is reached, it may be determined that the pressure vessel 9 is abnormal. In short, if it is a looseness confirmation process, it has reached a predetermined time after the engaging portion 51 is fitted into the lid 27, and if it is an tightening process, it has reached a predetermined time when the tightening of the lid 27 should be completed. If it can be detected, it can be replaced with other methods. For example, in the loosening confirmation step, it is possible to employ a method of determining abnormality when there is no input of a cut signal or a zero speed signal before the engaging portion 51 rotates 180 °.
[0070]
In the loosening confirmation process and the tightening process, the method for determining whether the engaging portion 51 (head 41) has rotated may be based on a signal from the rotary encoder. According to this configuration, even when a driver that is not configured to output a cut signal or a zero speed signal is used, the presence or absence of rotation of the engaging portion 51 can be detected based on a signal from the rotor encoder.
[0071]
It can also be determined whether it is abnormal from the rotation angle of the engaging part 51 (or motor). The servo driver 52 is set to output a signal when the engaging portion 51 is rotated by the set rotation angle, and a program is set that it is abnormal if the engaging portion 51 inputs a signal rotated by the set rotation angle. Leave in. In the loosening confirmation process, for example, 180 ° may be set as the set rotation angle.
[0072]
○ The rotation driving means is not limited to a motor (electric motor). For example, a fluid rotary drive device such as a nut runner that generates a rotational force by air pressure may be used. When using a fluid rotary drive device such as a nut runner, the generated torque is controlled by controlling the electro-pneumatic proportional valve based on the signal from the torque sensor and the signal obtained by feeding back the air pressure. can do. For example, control for compensating the air pressure so as to maintain a constant rotational speed may be adopted, and abnormality determination may be performed when the air pressure does not reach the set pressure before the predetermined time t1, t2. Alternatively, the nut runner may be driven with an air pressure that provides a constant torque, and the abnormality determination may be made when the rotation speed of the nut runner does not reach zero speed before the predetermined time t1, t2. Further, when using a motor, the present invention is not limited to a servo motor, and torque limiting control or torque control may be performed using a general-purpose motor by taking current feedback.
[0073]
○ The retightening device may be installed either upstream or downstream of the residual pressure inspection device in the filling line.
○ In the equipment other than the retightening equipment, inspection of the looseness confirmation process may be incorporated. Moreover, it can also be set as the test | inspection apparatus which implements only the test | inspection of a loosening confirmation process.
[0074]
○ The target pressure vessel is not limited to a barrel vessel filled with beer, juice, or the like, and may be for filling other liquids or gases. Any pressure vessel may be used as long as it has a lid (valve) that is screwed.
[0075]
Next, technical ideas other than the invention described in the claims that can be grasped from the respective embodiments and other examples will be described below together with their effects.
(1) In the pressure vessel inspection method, a weak torque that does not open if the lid is tightened with a specified force is applied to the lid at once or gradually, and information such as the rotational speed or torque at that time is taken in, Detecting lid abnormalities. According to this method, a pressure vessel in which the lid may be opened in the market can be found by a method other than the residual pressure test.
[0076]
(2) In claim 1 or (1), the retightening device is used to rotate the lid in the loosening direction before retightening. According to this method, a pressure vessel opened in the market can be found by a method other than the residual pressure test using a tightening device.
[0077]
(3) In claim 1 and any one of (1) and (2), if the torque is applied to the lid in the loosening direction and the rotation of the lid is not detected within the set time (t1), it is determined as normal. If the rotation of the lid is not detected even after the set time has elapsed, it is determined that there is an abnormality. According to this method or apparatus, it is possible to determine whether it is normal or abnormal before the set time elapses.
[0078]
(4) In Claims 2 to 5, the set torque in the loosening direction is a torque that does not open if the lid is tightened with a specified force. According to this configuration, the same effects as in the second to fifth aspects can be obtained.
[0079]
(5) In any one of claims 2 to 5 and (4), when the torque is applied to the lid in the loosening direction, if the rotation of the lid is not detected within the set time (t1) by the detection means, it is normal. If the rotation of the lid is not detected even after the set time has elapsed, it is determined that there is an abnormality. According to this configuration, it is possible to determine whether normal or abnormal before the set time elapses.
[0080]
(6) In the above (5), the set time when the torque in the loosening direction is applied is such that the engaging portion rotates by a predetermined rotation amount required to fit the engaging portion to the lid. It is longer than the required time and within 2 seconds. According to this configuration, since the inspection is completed in a short time, it is not necessary to reduce the retightening work capability so much.
[0081]
(7) In any one of claims 2 to 5 and (4) to (6), the fastening portion includes the engaging portion, the rotation driving means, the control means, and the detection means. Head unit. According to this head unit, the same effect as any one of claims 2 to 5 and (4) to (6) can be obtained.
[0082]
【The invention's effect】
[0083]
  As detailed aboveClaim1According to the invention described in the above, before retightening the lid, before retightening the lid, it is weaker than at the time of retightening.A lid that is torque and is only hand-tightened is opened and cannot be opened if the lid is tightened with a specified force.Torque is applied to the lid in the loosening direction, and it is determined that there is an abnormality when the lid is loose and rotation is detected, so that it is possible to find a pressure vessel that may have been opened in the market.
[0084]
  Claim2According to the invention described in (4), after the loosening confirmation process is completed, additional tightening is performed, and when the rotation of the engaging portion is detected at the time when the additional tightening of the lid is supposed to be completed, Can detect abnormalities such as packing.
[0085]
  Claim3According to the invention described in (4), the engagement portion is rotated at a constant rotation speed, and when the rotation torque of the engagement portion reaches the set torque in the rotation direction, it is determined that the pressure vessel is a normal pressure vessel. It is possible to find an abnormal pressure vessel that may have been opened or an abnormal pressure vessel that was not tightened.
[0086]
  Claim4According to the invention described in (4), the lid is opened in the market by rotating the engagement portion with a constant torque and determining that the pressure vessel is normal when the rotation speed of the engagement portion becomes zero. This makes it possible to detect abnormal pressure vessels that may have been damaged or to detect abnormal pressure vessels that have not been tightened.
[Brief description of the drawings]
FIG. 1 is a graph showing an inspection method in a first embodiment.
FIG. 2 is a graph illustrating an abnormality determination method using torque limit control.
FIG. 3 is a block diagram showing an electrical configuration of a retightening device.
FIG. 4 is a plan view showing a lid portion of the pressure vessel.
FIG. 5 is a side sectional view of the head unit.
FIG. 6 is a plan sectional view of a retightening device.
FIG. 7 is a side sectional view of the tightening device.
FIG. 8 is a block diagram showing an electrical configuration of a retightening device according to the second embodiment.
FIG. 9 is a graph for explaining an abnormality determination method by torque control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Retightening device, 2 ... Head unit, 9 ... Pressure vessel, 27 ... Lid, 37 ... Servo motor as rotation drive means, 51 ... Engagement part, 52 ... Servo driver as a detection means while comprising a control means 53. A controller that constitutes a control means and serves as a determination means.

Claims (4)

An engagement portion that rotates by engaging with the lid, a rotation drive unit that applies a rotational force to the engagement unit, a control unit that controls the rotation of the rotation drive unit, and the presence or absence of rotation of the engagement unit is detected. Detecting means for
  Prior to retightening the lid, the control means first opens the lid that is weaker than the tightening in the loosening direction to the lid engaged by the engaging portion, and the lid that is only hand-tightened is opened. Control the rotational drive means to give a torque that does not open if the lid is capped and tightened with a specified force,
  In the process of applying a set torque in the loosening direction to the lid, the detection unit includes a determination unit that determines that the rotation is normal if the rotation of the lid is not detected and determines that the rotation is abnormal if the rotation of the lid is detected. A pressure vessel retightening device. After the end of the looseness confirmation step of applying a set torque in the loosening direction to the lid and checking whether or not the lid rotates, the control means tightens in the tightening direction on the engaging portion that engages with the lid. In the retightening process for controlling the rotation driving means to apply torque, the determination means detects the rotation of the engaging portion by the detecting means at the time when the cover should be retightened. The pressure vessel retightening device according to claim 1, wherein the pressure vessel is determined to be abnormal. The control means controls the torque of the rotation driving means so as to rotate the engagement portion at a constant rotation speed, and the detection means has detected that the rotation torque of the engagement portion has reached a set torque in the rotation direction. 3. The pressure vessel retightening device according to claim 1, wherein the rotation stop state of the engaging portion is detected. The control means controls the rotation driving means for applying a constant torque to the engagement portion, and the detection means detects the rotation speed of the engagement portion, and the rotation speed of the engagement portion. 3. The pressure vessel retightening device according to claim 1, wherein the rotation stop state of the engaging portion is detected when the zero speed is reached. 4.

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