JP2005161344A - Automatic molten metal supplying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply always a fixed quantity of molten metal into a molding apparatus, even in the case of varying the leaked quantity of molten metal leaked from sliding surface of a molten metal cylinder. <P>SOLUTION: The leaked quantity of the molten metal leaked from the molten metal supplying cylinder is calculated with a leaked quantity calculating part 36 by using the relation between the height detected with a molten metal surface height measuring instrument 33 and the molten metal supplied quantity based on a stroke amount of a molten metal supporting piston. A correcting quantity of the stroke amount of the molten metal supplying piston is calculated with a correcting part 37 so as to supply the fixed quantity of the molten metal into the molding apparatus based on the value of the leaked quantity calculating part 36. The stroke amount of the molten metal supplying piston is controlled with a controlling part 38 based on a signal from a correcting part 37. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic molten metal supply apparatus that automatically supplies a molten metal of non-ferrous metal such as an aluminum alloy from a holding furnace for melting metal to a forming apparatus by a hot water supply apparatus through a hot water supply pipe.

2. Description of the Related Art Conventionally, as an automatic molten metal supply apparatus that automatically supplies molten metal from a holding furnace to a molding apparatus, an electromagnetic type or a float type is known. In these automatic molten metal supply apparatuses, in order to supply the molten metal from the holding furnace to the molding apparatus, the hot water supply apparatus in the holding furnace and the molding apparatus are connected by a hot water supply pipe made of metal, ceramic, or the like. By the way, when the hot water supply apparatus is configured with a hot water supply cylinder and a hot water supply piston as in Patent Document 1, the amount of hot water varies depending on the height of the hot water surface in the holding furnace. The hot water level is detected by a hot water level detection device, and the stroke amount of the hot water supply piston is corrected according to the hot water level to keep the hot water level constant.
Japanese Patent Laid-Open No. 05-123848

  However, even if it is attempted to quantify the amount of hot water supply as described above, the hot water supply piston moves forward and backward without sliding the hot water supply cylinder, so that a slight amount of molten metal leaks from the sliding surface of the hot water supply cylinder. However, in Patent Document 1 in which measures for this are not taken, the amount of hot water supply still fluctuates.

  The present invention has been made in view of such a point, and an object of the present invention is to change the leakage amount of the molten metal leaking from the sliding surface of the hot water supply cylinder due to the fluctuation of the molten metal surface height in the holding furnace. However, it is always to supply a certain amount of molten metal to the molding apparatus.

  In order to achieve the above object, the present invention is characterized in that the stroke amount of the hot water supply piston is corrected and controlled in accordance with the amount of molten metal leakage from the hot water supply cylinder sliding surface.

  Specifically, the present invention is directed to an automatic molten metal supply device that automatically supplies a molten metal in a holding furnace through a hot water supply pipe to a forming device through a hot water supply pipe, and has taken the following solution. .

  That is, the present invention provides a hot water supply device having a hot water supply cylinder immersed in the molten metal in the holding furnace and a hot water supply piston inserted into the hot water supply cylinder so as to be able to advance and retreat, and the hot water in the furnace provided in the holding furnace. A leak level calculating device that detects the surface height, and a leak amount that calculates the amount of molten metal leaking from the hot water supply cylinder based on the relationship between the hot water level detected by the hot water level detection device and the hot water supply amount based on the stroke amount of the hot water supply piston. A correction unit for calculating a correction value for the stroke amount of the hot water supply piston so that a fixed amount of hot water is supplied to the molding apparatus based on the value of the leakage amount calculation unit, and a signal from the correction unit And a controller having a controller for controlling the stroke amount of the hot water supply piston.

  According to the present invention, a fixed amount of molten metal is always stably supplied to the molding device by correcting and controlling the piston stroke amount in consideration of the hot water supply amount that changes due to the fluctuation of the leakage amount due to the molten metal surface height. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show an automatic melt feeder A according to an embodiment of the present invention. 1-3, 1 is a holding furnace for holding a molten metal M of a non-ferrous metal such as an aluminum alloy, and 2 is a hot water supply apparatus. The holding furnace 1 is provided with an upper lid 3 having an opening 3 a, and the hot water supply device 2 is connected to a first support frame 4 erected on the upper lid 3 via a shaft 5, a universal joint 6 and a spring member 7. The lower hot water supply unit 8 that is the main body of the hot water supply device 2 is always dipped in the molten metal M in the holding furnace 1.

  Therefore, even if the vibration of the forming apparatus B is transmitted to the hot water supply device 2 through the hot water supply pipe 22 described later, the vibration is efficiently absorbed by the movement of the hot water supply device 2 in the three-dimensional direction, so that the hot water supply pipe 22 and the hot water supply device 2 are It can be prevented from being damaged, and the molten metal M can be reliably prevented from leaking to the outside. Moreover, since only the hot water supply device 2 is suspended, the installation of a large horizontal movement device is eliminated, and a relatively compact facility is sufficient, and the facility cost can be reduced.

  The hot water supply device 2 includes the hot water supply unit 8 and an upper drive unit 9, and the drive unit 9 is disposed on the plate 10 disposed corresponding to the opening 3 a of the upper lid 3, and the upper surface of the plate 10. The second support frame 11 is connected, and the shaft 5 is fitted into the second support frame 11 so that the second support frame 11 is suspended and supported by the first support frame 4. The second support frame 11 is provided with a hot water supply piston drive device 12 and a tap valve drive device 13. The hot water supply piston drive device 12 includes an electric cylinder 14 having a rod 14a extending downward, and an upper end of a shaft 15 is connected to the lower end of the rod 14a. The shaft 15 passes through the first through hole 10a of the plate 10. Then, it is immersed in the molten metal M in the holding furnace 1, and a ceramic hot water supply piston 16 is integrally attached to the lower end. Thereby, the hot water supply piston 16 is connected to the electric cylinder 14 of the hot water supply piston drive device 12 via the shaft 15. On the other hand, the tap valve driving device 13 also includes a fluid pressure cylinder 17 having a rod 17a extending downward, shafts 18 and 19 are connected to the lower end of the rod 17a, and the lower shaft 19 is the second of the plate 10. The ceramic tap valve 20 is integrally attached to the lower end through the through hole 10b and immersed in the molten metal M in the holding furnace 1.

  On the other hand, as shown in FIG. 3, the hot water supply section 8 has a substantially pentagonal shape in plan view and is made of graphite. Ceramic pillars 21 made of pipe material are erected at three corners, respectively. The upper end of the column 21 passes through the third through hole 10 c of the plate 10 and is fixed to the upper surface of the plate 10, and the hot water supply unit 8 is supported by the plate 10 as a support unit by the three columns 21. One end of a hot water supply pipe 22 is connected to the hot water supply section 8. The connecting point is a position that forms a rectangular apex with the three columns 21, and the hot water supply pipe 22 penetrates the fourth through hole 10 d of the plate 10 and is fixed to the upper surface of the plate 10, and also functions as a column. The three water columns 21 and the hot water supply pipe 22 support the hot water supply unit 8.

  Thereby, since one support | pillar can be abbreviate | omitted, it can be set as a compact layout. In addition, since the hot water supply section 8 is made of graphite, a molten metal passage 24, a molten metal introduction path 26, a remaining molten metal discharge section 30, and the like described later can be easily formed. Furthermore, since the support column 21 that supports the hot water supply unit 8 is made of ceramic, durability against the molten metal M can be improved.

  A hot water supply cylinder 23 that is constantly immersed in the molten metal M in the holding furnace 1 is provided at the approximate center surrounded by the three support columns 21 and the hot water supply pipe 22 of the hot water supply unit 8. The hot water supply piston 16 is inserted so as to be able to advance and retract in the vertical direction by the operation of the hot water supply piston drive device 12 (electric cylinder 14).

  As described above, by arranging the hot water supply cylinder 23 and the hot water supply piston 16 at substantially the center of the hot water supply portion 8, the hot water supply portion 8 can be stably supported against pressurization by the advance operation of the hot water supply piston 16.

  The hot water supply piston 16 can be removed from the hot water supply cylinder 23 by increasing the amount of operation of the hot water supply piston drive device 12 (electric cylinder 14) during maintenance or the like.

  Therefore, when removing the hot water supply unit 8 from the holding furnace 1 for maintenance or the like, the hot water supply piston 16 can be easily and smoothly removed from the hot water supply unit 8 first, so that the hot water supply piston 16 and the hot water supply unit 8 are different in material and the like. Even if the thermal contraction rate differs, it is possible to prevent the hot water supply piston 16 and the hot water supply section 8 from being damaged by the difference in contraction.

  The hot water supply section 8 is formed with a molten metal passage 24 having one end connected to the hot water supply pipe 22 and the other end connected to the hot water supply cylinder 23. In the middle of the molten metal passage 24, the valve cylinder 25 is inserted extending in the vertical direction at a position corresponding to the apex of the pentagonal shape of the hot water supply section 8, and a communication hole 25 a is formed in the middle of the valve cylinder 25. And a valve seat 25b on which the tap valve 20 is seated are formed at the lower end. Thus, the upper half of the inside of the valve cylinder 25 is used as a molten metal introduction path 26 that guides the molten metal M in the holding furnace 1 to the molten metal path 24, and the molten metal introduction path 26 is connected to the molten metal path 24. The molten metal passage 24 includes a first passage 27 extending obliquely downward from the connecting end of the hot water supply pipe 22, and a second passage 28 extending upward from the lower end of the first passage 27 and connected to the lower end of the molten metal introduction passage 26. And a third passage 29 extending obliquely upward from the upper end of the second passage 28 and connected to the hot water supply cylinder 23. Therefore, the second passage 28 is constituted by the lower half portion of the cylindrical member 25. In addition, a remaining hot water discharge unit 30 communicating with the inside of the holding furnace 1 is opened at a lower end portion of the first passage 27 corresponding to the lower side of the second passage 28, and the remaining hot water discharge unit 30 is normally closed by a plug 31. ing. The remaining hot water discharge portion 30 may not be opened from the beginning, and may be closed by a plug after being drilled during maintenance or the like to discharge the molten metal.

  Thus, since the molten metal channel | path 24 and the hot water supply cylinder 23 are always immersed in the molten metal M, the molten metal M can be supplied stably. In particular, if the upper end portion of the hot water supply cylinder 23 protrudes from the hot water surface and comes into contact with the atmosphere, oxides accumulate on the boundary portion between the molten metal M and the air, which may be an obstacle when the hot water supply piston 16 is pulled out for maintenance or the like. However, since the hot water supply cylinder 23 is always immersed in the molten metal M, the hot water supply piston 16 can be smoothly pulled out without the accumulation of oxide as described above. Moreover, since the molten metal introduction path 26 is always immersed in the molten metal M, it is possible to prevent a situation in which foreign matters such as oxides in the upper layer portion of the molten metal and deposits in the lower layer portion of the molten metal are sucked. Further, when the hot water supply unit 8 is taken out of the holding furnace 1 for maintenance of the hot water supply device 2 or the like, the molten metal M in the hot water supply unit 8 (first to third passages 27 to 29) is transferred to the remaining hot water discharge portion at the lower end of the first passage 27. Since it can discharge | emit into the holding furnace 1 from 30, the situation where the molten metal M remains in the hot water supply part 8 and solidifies can be prevented. Further, the structure can be simplified by using the second passage 28 and the molten metal introduction passage 26 as one passage.

  A shaft 19 that connects the tap valve driving device 13 (fluid pressure cylinder 17) and the tap valve 20 passes through the molten metal introduction passage 26, and the tap valve 20 enters the second passage 28 in the tap valve driving device 13 (fluid pressure). The cylinder 17) is arranged so that it can be moved up and down. Then, the tap valve 20 is lowered to connect the molten metal introduction passage 26 and the third passage 29 and to shut off the first passage 27 and the third passage 29, while the tap valve driving device 13 is raised to raise the first passage. The first passage 27 and the third passage 29 are communicated with each other, and the molten metal introduction passage 26 and the third passage 29 are blocked. The tap valve 20 can also be removed from the second passage 28 by increasing the operation amount of the tap valve driving device 13 (fluid pressure cylinder 17) during maintenance or the like.

  Therefore, the communication state of the first to third passages 27 to 29 can be switched by a simple operation of moving the tap valve 20 up and down. Furthermore, since the tap valve 20 can be removed from the second passage 28 by largely moving the tap valve 20 upward, the tap valve 20 can be easily and smoothly removed from the hot water supply unit 8. Therefore, when removing the hot water supply unit 8 from the holding furnace 1 for maintenance or the like, the tap valve 20 can be easily removed from the hot water supply unit 8 first, so that the tap valve 20 and the hot water supply unit 8 are heated due to a difference in material or the like. Even if the shrinkage rates are different, it is possible to prevent the tap valve 20 and the hot water supply unit 8 from being damaged by the shrinkage difference.

  The lower end of a ceramic cylindrical filter 32 is connected to the molten metal introduction path 26 so that the upper end protrudes upward from the molten metal surface in the holding furnace 1, and the shaft 19 is surrounded by the filter 32. It is inserted and arranged with a gap. The upper end of the filter 32 is supported by the plate 10 on the support portion side.

  Therefore, foreign matters such as impurities adhering to the filter 32 can be removed by the molten metal backflow generated with the upward movement of the tap valve 20 and the advance operation of the hot water supply piston 16, so the number of replacements of the filter 32 due to clogging can be reduced. This can reduce the running cost. Furthermore, since the lower end of the filter 32 is held by the hot water supply unit 8 and the upper end is held by the plate 10, the mounting posture of the filter 32 can be stabilized. Moreover, since the filter 32 can be removed from the hot water supply unit 8 by removing the upper end of the filter 32 from the plate 10, the filter 32 can be easily replaced while the hot water supply unit 8 remains in the holding furnace 1. Further, since the filter 32 protrudes upward from the molten metal surface in the holding furnace 1, the molten metal M in the holding furnace 1 always passes through the filter 32 and is sucked into the hot water supply cylinder 23, and oxides and impurities in the molten metal M are present. It is possible to reliably prevent a foreign matter such as the like from being sucked into the hot water supply cylinder 23.

  The other end of the hot water supply pipe 22 protrudes upward from the plate 10 and is connected to the injection sleeve b1 of the molding apparatus B. Thereby, the hot water supply unit 8 of the hot water supply apparatus 2 is connected to the molding apparatus B through the hot water supply pipe 22, and the molten metal M in the holding furnace 1 is fixed to the injection sleeve b 1 of the molding apparatus B through the hot water supply pipe 22 by the hot water supply apparatus 2. The injection plunger b2 is advanced by an operating device (not shown) and injected into a cavity b6 of a mold b5 composed of a fixed mold b3 and a movable mold b4.

The molten metal M in the holding furnace 1 decreases as the number of shots increases, and the molten metal level decreases. To monitor this, the upper surface of the upper lid 3 of the holding furnace 1 detects the molten metal level in the furnace. A hot water surface height measuring device 33 as a hot water surface detecting device is inserted and installed in the through hole 3b of the upper lid 3, and the hot water surface height measuring device 33 has a lower end detection rod 33a in the through hole 3b. The tip is inserted into the furnace. The hot water surface height measuring device 33 is connected to the control device 34 together with the hot water supply piston driving device 12 and the tap valve driving device 13. The control device 34 controls the operation of the hot water supply piston drive device 12 (electric cylinder 14) and the tap valve drive device 13 (fluid pressure cylinder 17) and makes the amount of hot water supply constant. That is, it is unavoidable that the molten metal M leaks slightly from the piston sliding surface in the hot water supply cylinder 23, and it is necessary to control the stroke amount of the hot water supply piston 16 according to the leakage amount because it is necessary to compensate for this leakage amount. This amount of leakage has a correlation with the molten metal surface height. As shown in FIG. 7, the control device 34 includes a reference data storage unit 35 that stores reference data necessary for calculating the leakage amount. The reference data is data representing the relationship between the hot water surface height X in the holding furnace 1 and the hot water supply amount Q, which is shown in FIG. With this reference data,
Q = aX + b (a and b are constants)... (1)
The following relational expression holds. It should be noted that this equation (1) is, from a physical logic point of view,

However, Expression (1) is obtained by approximating Expression (1 ′) to a linear form, and there is no problem even if Expression (1) is substituted.

In addition, the control device 34 includes a leakage amount calculation unit 36 that calculates the leakage amount of the molten metal M leaking from the hot water supply unit 8. By this leak amount calculation unit 36, an arbitrary hot water level can be determined depending on the relationship (formula (1)) between the hot water surface height X detected by the hot water surface height measuring device 33 and the hot water supply piston 16 stroke amount. The leakage amount r with respect to the reference hot water supply amount Q _{0 at the surface} height X is expressed by the following equation (2)
r = a (X ₀ −X) (2)
More calculated.

Further, the control device 34 includes a correction unit 37 and a control unit 38. The correction unit 37 sets a correction value for the stroke amount of the hot water supply piston 16 based on the value (leakage amount r) of the leakage amount calculation unit 36 so that a fixed amount of hot water is supplied to the molding apparatus B, using the following equation (3).
S _x = r / q ₀ = a (X ₀ −X) / q ₀ Formula (3)
a: Leakage rate constant
X ₀ : Standard hot water surface height
X: Hot water surface height
q ₀ : Unit stroke hot water supply
S _x : It is calculated from the stroke correction amount.

The control unit 38 controls the overall operation of the automatic molten metal supply apparatus A such as the advance / retreat operation of the hot water supply piston 16 and the timing thereof, the up / down operation of the tap valve 20 and the timing thereof, and based on the signal from the correction unit 37. The stroke amount of the hot water supply piston 16 is corrected and controlled. That is, the stroke amount of the hot water supply piston 16 to change in response to the leakage amount r of the molten metal M by adding the stroke correction amount S _x calculated by the above formula (3) to the reference stroke S _0, hot water supply piston driven based on this The device 12 (electric cylinder 14) is actuated.

  As described above, since the amount of hot water supplied to the hot water supply cylinder 23 is corrected and controlled in accordance with the amount of leakage of the molten metal M, the molten metal M can be stably supplied to the molding apparatus B while keeping the amount of hot water supplied constant. it can.

  Next, the operation of the automatic molten metal supply apparatus A configured as described above will be described with reference to the operation process diagram of FIG. 4 and the control flowchart of FIG.

  (1) As shown in FIG. 4A, the tap valve 20 is in the lower end position, the molten metal introduction path 26 and the third path 29 are communicated, and the first path 27 and the third path 29 are blocked. . In this state, the electric cylinder 14 of the hot water supply piston driving device 12 is contracted to raise the hot water supply piston 16. By this operation, the molten metal M in the holding furnace 1 is sucked into the hot water supply cylinder 23 through the filter 32, the molten metal introduction path 26, the second passage 28 and the third passage 29. At this time, the stroke amount of the hot water supply piston 16 is set so as to be retracted to an upper position where the molten metal M is supplied to the molding apparatus B so as to be sucked into the hot water supply cylinder 23.

  (2) As shown in FIG. 4B, the electric cylinder 14 is extended, and the hot water supply piston 16 is lowered to a predetermined position so as to supply a set amount of hot water 5 to the molding apparatus B. Is returned to the holding furnace 1. By this operation, the molten metal M corresponding to the capacity of the cavity b6 is stably secured without variation. Thereby, the hot water supply system of the hot water supply piston 16 is prepared.

At this stage, the control device 34 performs correction control of the hot water supply amount. The procedure is as follows. In the control flowchart of FIG. 6, it is first determined in step S1 whether or not the hot water supply state of the hot water supply piston 16 is in place. If the hot water supply system is ready, the number of hot water supply after the previous correction is confirmed in step S2, and it is determined whether or not the hot water supply frequency is in the correction cycle (n = n ₀ ). If it is in the correction period, the process proceeds to step S3, where the molten metal surface height X is measured by the molten metal surface height measuring device 33, and this measured value is input to the leakage amount calculating unit 36 and compared with the reference data storage unit 35. Thus, the leakage amount of the molten metal M leaking from the hot water supply unit 8 is calculated. This calculated value is transmitted to the correction unit 37, and in step S4, the stroke correction amount _Sx of the hot water supply piston 16 is expressed by the above equation (3), that is,
S _x = r / q ₀ = a (X ₀ −X) / q ₀
Is required. This correction signal is transmitted to the control unit 38, the stroke amount of the hot water supply piston 16 is corrected as S ← S ₀ + S _x in step S5, and the stroke amount of the electric cylinder 14 (hot water supply piston 16) is determined according to the leakage amount of the molten metal M. Changed. This changed stroke amount is maintained until the next correction cycle. Then, the count of the hot water supply count is returned to zero in step S6, and the hot water supply count is counted in step S7.

  (3) As shown in FIG. 4C, the second fluid pressure cylinder 17 is contracted to move the tap valve 20 upward. Thereby, the molten metal introduction path 26 and the 3rd channel | path 29 are interrupted | blocked, the 1st-3rd channel | paths 27-29 are connected, and the hot water supply system of a molten metal channel | path is prepared.

  (4) As shown in FIG. 4 (d), the electric cylinder 14 is extended to lower the hot water supply piston 16. Thereby, the molten metal M is supplied to the injection sleeve b1 of the molding apparatus B through the hot water supply pipe 22.

  (5) As shown in FIGS. 4E and 4F, the injection plunger b2 is advanced to inject the molten metal M in the injection sleeve b1 into the cavity b6 of the mold b5. Further, when the injection plunger b2 passes through the hot water supply pipe connection portion (melt supply port) of the injection sleeve b1, the electric cylinder 14 is contracted to raise the hot water supply piston 16 slightly, and the molten metal M in the hot water pipe 22 is A part is returned to the hot water supply unit 8. This operation is for ensuring the volume of the volume when the tap valve 20 moves downward and the molten metal M in the second passage 28 is pushed out to the hot water supply pipe 22 in the next stroke.

  (6) As shown in FIG. 4 (f), the second fluid pressure cylinder 17 is extended to move the tap valve 20 downward. As a result, the first passage 27 and the third passage 29 are shut off, the molten metal introduction passage 26 and the third passage 29 communicate with each other, and the molten metal suction state prepared for the next molding is restored. In the cavity b6 of the mold b5, the filled molten metal M is solidified to become a casting C, and one shot is completed.

  The present invention is useful when casting a casting using a non-ferrous metal such as an aluminum alloy, a magnesium alloy, a zinc alloy, and a copper alloy.

It is a block diagram of the automatic molten metal supply apparatus which concerns on embodiment, and a hot-water supply part is a cross section corresponded to the XX line of FIG. It is an enlarged view of the hot water supply part in FIG. It is sectional drawing in the YY line of FIG. The operation process of the automatic molten metal supply apparatus which concerns on embodiment is shown, (a) is a molten metal suction process, (b) is a molten metal amount adjustment process, (c) is a hot water supply preparation process, (d) is a hot water supply start process, ( e) is a molten metal injection step, and (f) is a molten metal suction state returning step. It is a graph which shows the relationship between the amount of hot water supply of an automatic molten metal supply apparatus, and the hot_water | molten_metal surface height in a holding furnace. It is a flowchart which carries out correction | amendment control of the stroke amount of a hot water supply piston. It is a control block diagram of an automatic molten metal supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Holding furnace 2 Hot-water supply apparatus 16 Hot-water supply piston 22 Hot-water supply pipe 23 Hot-water supply cylinder 33 Hot-water surface height measuring device (hot-water surface detection apparatus)
34 Control device 36 Leakage amount calculation unit 37 Correction unit 38 Control unit A Automatic molten metal supply device B Molding device M Molten metal

Claims (1)

An automatic molten metal supply device that automatically supplies a fixed amount of molten metal in a holding furnace to a molding device through a hot water supply pipe by a hot water supply device,
A hot water supply apparatus having a hot water supply cylinder immersed in the molten metal in the holding furnace, and a hot water supply piston inserted into the hot water supply cylinder so as to be able to advance and retreat;
A hot water level detection device that is provided in the holding furnace and detects the hot water level in the furnace;
A leakage amount calculation unit that calculates the leakage amount of the molten metal that leaks from the hot water supply cylinder based on the relationship between the hot water surface level detected by the hot water level detection device and the hot water supply amount based on the stroke amount of the hot water supply piston, and the value of the leakage amount calculation unit A correction unit that calculates a correction value of the stroke amount of the hot water supply piston so that a fixed amount of hot water is supplied to the molding apparatus based on the control, and a control that controls the stroke amount of the hot water supply piston based on a signal from the correction unit An automatic molten metal supply apparatus comprising a control device having a section.

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