JP7430462B2 - work vehicle - Google Patents

Description

The present invention relates to a work vehicle.

BACKGROUND ART Conventionally, work vehicles equipped with a wash water tank for convenient washing have been known (for example, see Patent Document 1). In this suction vehicle (work vehicle), water from a wash water tank is used to collect, load, transport, and extract materials to be treated such as sewage, sludge, and earth and sand.

Conventionally, water in such wash water tanks was pumped by a hydraulically driven water pump. However, there is a possibility that the temperature of the hydraulic oil in the hydraulic actuator that drives the water pump may rise due to continuous use of cleaning water, and there is a risk that hydraulic equipment and other equipment may malfunction due to the temperature rise.

JP2015-224422A

The present invention has been made in view of the above-mentioned circumstances, and provides a work vehicle capable of suppressing the temperature rise of hydraulic oil of a hydraulic actuator that drives a water pump with a compact and low-cost configuration. The purpose is to

The present invention constitutes means for solving the above-mentioned problems as follows. That is, the present invention provides a cleaning water tank, a water flow path for ejecting water from the cleaning water tank from a nozzle, a water pump that is interposed in the water flow path to pump water, and a water pump that drives the water pump. A work vehicle comprising a hydraulic actuator, a hydraulic oil tank for storing hydraulic oil for the hydraulic actuator, and an oil cooler for suppressing a temperature rise of the hydraulic oil, the working vehicle for flowing the working fluid for the oil cooler. A working fluid flow path is formed by a part of the water flow path, and the oil cooler is interposed between the washing water tank and the water pump in the water flow path. The fluid is water that is pumped from the wash water tank to the nozzle by driving the water pump .

According to the above configuration, it is possible to suppress the temperature rise of the hydraulic oil of the hydraulic actuator that drives the water pump with a compact and low-cost configuration. Specifically, since the oil cooler can cool the hydraulic oil of the hydraulic actuator that drives the water pump, it is possible to prevent equipment failure due to an increase in the temperature of the hydraulic oil. In addition, since the oil cooler uses water that is pumped from the wash water tank to the nozzle as the working fluid, the equipment surrounding the oil cooler can be simplified compared to the case where a dedicated working fluid is used. As a result, the entire device can be made compact, and the cost of the device can also be reduced. In addition, the unused, low-temperature water in the wash water tank can be used as the working fluid for the oil cooler before passing through the hot water pump, further increasing the cooling effect of the oil cooler. .

In the work vehicle configured as described above, the oil cooler is attached to the hydraulic oil tank such that one longitudinal end thereof projects inward of the hydraulic oil tank, and the oil cooler and the hydraulic oil tank are connected to each other. Preferably, it is provided integrally.

According to the above configuration, since the oil cooler is integrated with the hydraulic oil tank, compared to the case where the oil cooler and the hydraulic oil tank are arranged separately on the chassis, the piping connecting the oil cooler and the hydraulic oil tank is Installation space can be reduced. This makes it possible to provide a compact and low-cost work vehicle.

According to the work vehicle of the present invention, a temperature rise in the hydraulic oil of the hydraulic actuator that drives the water pump can be suppressed with a compact and low-cost configuration.

1 is a side view showing a schematic configuration of a suction wheel according to an embodiment of the present invention. FIG. 2 is a plan view of the suction wheel of FIG. 1; FIG. 2 is an air piping diagram of the suction device mounted on the suction wheel of FIG. 1, showing the flow of air during suction. In the air piping diagram of FIG. 3, it is a diagram showing the flow of air during pressurization. FIG. 2 is a perspective view of the water ring pump, tertiary catcher, quaternary catcher, etc. of the suction device mounted on the suction wheel of FIG. 1, viewed from the front left. FIG. 2 is a perspective view of the water ring pump, tertiary catcher, quaternary catcher, etc. of the suction device mounted on the suction wheel of FIG. 1, viewed from the rear left. FIG. 2 is a diagram showing a schematic configuration of a hydraulic circuit and the like for driving a water pump.

An embodiment in which the present invention is applied to a suction wheel will be described with reference to the drawings. That is, a case will be described in which the work vehicle according to the present invention is a suction vehicle equipped with a hydraulically driven water pump that pumps water from a wash water tank.

1 and 2 show a suction wheel 2 according to an embodiment of the present invention. A suction device 1 is provided on a subframe 4 on a chassis 3 of this suction wheel 2. Specifically, a receiver tank 5 is mounted at the rear of the subframe 4 to collect objects to be collected, such as sludge, earth and sand, waste liquid, and the like.

The receiver tank 5 includes, for example, a tank body 5a having a circular cross-sectional container shape and a rear end opening, and a tail gate 5c that opens and closes the rear end opening. The tailgate 5c is rotatably supported, for example, at the upper rear end of the tank body 5a via a hinge pin 5b. An opening/closing cylinder 5d is provided between the tank body 5a and the tailgate 5c, and by expanding and contracting the opening/closing cylinder 5d, the tailgate 5c can open and close the rear end opening of the tank body 5a. There is.

At the bottom of the tailgate 5c, there are provided a suction port 8 with an on-off valve that serves as a suction port for objects to be collected, and a discharge port 9 with an on-off valve that serves as an outlet for discharging objects to be collected. The receiver tank 5 is pivotally supported so as to be tiltable relative to the subframe 4 via a tilting shaft 10 provided at the rear of the subframe 4. That is, a tilting cylinder 11 is provided between the subframe 4 and the receiver tank 5. By expanding and contracting the tilting cylinder 11, the receiver tank 5 is rotated upright or down around the tilting shaft 10.

As will be described in detail later, when the suction device 1 sucks and collects the object into the receiver tank 5, the reduced pressure inside the receiver tank 5 and the flow of air cause the object to be collected from the outside through a suction hose (not shown) connected to the suction port 8. The object to be collected is sucked into the receiver tank 5. On the other hand, when the suction device 1 discharges the material to be recovered in the receiver tank 5 to a sludge treatment plant, for example, the air in the receiver tank 5 is pressurized and the air is passed through the receiver tank 5 through a discharge hose (not shown) connected to the discharge port 9. The items to be collected inside are discharged to the outside. Furthermore, by opening the tailgate 5c and rotating the receiver tank 5 in an upright position, it is also possible to discharge the objects to be collected in the receiver tank 5.

Further, on the subframe 4 between the driver's cab 13 and the receiver tank 5, a water ring pump 25, an oil reservoir 31, etc., which increase and decrease the pressure of the air in the receiver tank 5 to generate an air flow are provided. ing. Although not shown in detail, the water ring pump 25 is rotatably driven by the driving force of an engine E (see FIG. 7) connected to the PTO drive shaft of the suction wheel 2. Further, a hydraulic pump 26 is provided on the subframe 4 (see FIG. 7). The hydraulic pump 26 allows the hydraulic oil stored in the oil reservoir 31 to pass through the hydraulic control circuit C1 (see FIG. 7) to the hydraulic motor 32 (which drives the opening/closing cylinder 5d, the tilting cylinder 11, and the water pump 33 (described later)). (see Figure 7), etc. The hydraulic control circuit C1 is provided with various valves and the like for controlling the operating states of the opening/closing cylinder 5d, the tilting cylinder 11, the hydraulic motor 32, and the like. Arranged around the water ring pump 25 are piping connected to the water ring pump 25, various valves, an operation panel 15, and the like. For example, one end of the water suction hose 28 (see FIG. 5) is connected to the water suction port 25c of the water ring pump 25, and the water stored inside the quaternary catcher 22 is transferred to the water ring pump 25 through the water suction hose 28. It can be supplied into the pump 25.

As shown in FIGS. 3 to 6, the suction device 1 includes a receiver tank 5 as a primary catcher, a secondary catcher 20 and a tertiary catcher 21 consisting of a cyclone type dust collector, and a 4 A secondary catcher 22 and the like are provided, and these devices are connected via a receiver tank pressurization and depressurization piping 7 made of, for example, a metal round steel pipe. In this embodiment, the tertiary catcher 21 and the quaternary catcher 22 are provided integrally. The specific configurations of the tertiary catcher 21 and the quaternary catcher 22 will be described later.

The receiver tank 5 is connected to the secondary catcher 20 by a first pipe 7a. Further, the secondary catcher 20 is connected to the tertiary catcher 21 by a second pipe 7b. Although the secondary catcher 20 is shown in FIGS. 3 and 4, it is not shown in FIGS. 1, 2, 5, and 6.

The water ring pump 25, tertiary catcher 21, quaternary catcher 22, and integrated silencer 23 are connected to an air switching type four-way valve 24 via piping. Specifically, the water ring pump 25 has a suction port 25a and a discharge port 25b. The tertiary catcher 21 and the air switching type four-way valve 24 are connected by a third pipe 7c. Further, the suction port 25a of the water ring pump 25 and the air switching type four-way valve 24 are connected by a fourth pipe 7d. Further, the quaternary catcher 22 and the air switching type four-way valve 24 are connected by a fifth pipe 7e. Further, the integrated silencer 23 and the air switching type four-way valve 24 are connected by a sixth pipe 7f. The discharge port 25b of the water ring pump 25 is connected to the quaternary catcher 22 by a seventh pipe 7g.

During suction, the tertiary catcher 21 and the suction port 25a of the water ring pump 25 are connected via the air switching type four-way valve 24, while the quaternary catcher 22 and the integrated silencer 23 are connected via the air switching type four-way valve 24. It is designed to be connected via. Furthermore, by switching the air switching type four-way valve 24, during pressurization, the integrated silencer 23 and the suction port 25a of the water ring pump 25 are connected via the air switching type four-way valve 24, while the fourth catcher 22 and the tertiary catcher 21 are connected via an air switching type four-way valve 24.

An ejector 30 is installed in a pipe connecting the receiver tank 5 and the water ring pump 25 to introduce air at a higher pressure than the upstream side of the pipe as driving air. Specifically, the ejector 30 is interposed in the fourth pipe 7d between the air switching type four-way valve 24 and the water ring type pump 25. Note that the fourth pipe 7d may be provided with a bypass passage (not shown) that passes from the air switching type four-way valve 24 to the suction port 25a without passing through the ejector 30. Driving air for the ejector 30 is supplied through piping from an air tank (not shown). The air tank is provided, for example, on the side of the vehicle chassis 3 and stores pressurized air used when braking the vehicle. For example, pressurized air of 0.7 MPa is supplied from the air tank.

A four-way valve switching valve unit (not shown) is connected to the air switching type four-way valve 24, and pressurized air from an air tank can be supplied thereto. Pressurized air is supplied from the air tank to the air switching type four-way valve 24 based on pressing any one of the suction button 15a, the neutralization button 15b, and the pressurization button 15c provided on the operation panel 15 (see FIG. 1). The air switching type four-way valve 24 is switched and controlled by the pressure of this pressurized air.

The operation of the suction device 1 having the above configuration will be explained.

First, with the suction wheel 2 stopped running, a PTO switch provided in the driver's cab 13 or the like is turned on. Then, the driving force of the engine for driving the vehicle is supplied to the water ring pump 25.

Next, the operator presses the suction button 15a on the operation panel 15 to start suction. Then, the spool of the air switching type four-way valve 24 moves to the suction side due to the pressure of the pressurized air in the air tank.

Next, the air switching type four-way valve 24 is switched to the state shown in FIG. Air passes through the receiver tank 5, the secondary catcher 20, and the tertiary catcher 21, passes through the air switching type four-way valve 24, and is sucked in from the suction port 25a of the water ring pump 25. At this time, air from the air switching type four-way valve 24 passes through the ejector 30.

At the start of suction, the negative pressure inside the receiver tank 5 is not higher than the predetermined value (pressure is higher than the predetermined value), so external air (atmosphere) is suctioned through the external air introduction pipe. As a result, the atmosphere is introduced into the ejector 30. In this way, when the differential pressure between the atmosphere and the inside of the receiver tank 5 is small, such as when the water ring pump 25 is driven, the water ring pump 25 does not easily generate heat, so even if atmospheric pressure is used, the cooling capacity is not sufficient. can be demonstrated. Since external air having a lower temperature than the seal water is sent to the water ring pump 25, the temperature rise of the water ring pump 25 and the seal water is suppressed.

On the other hand, when the negative pressure inside the receiver tank 5 increases, the load on the water ring pump 25 increases, heat generation increases, and the water temperature tends to rise. As the negative pressure increases, the sealed water becomes more likely to evaporate, making cavitation more likely to occur. Therefore, when the negative pressure inside the receiver tank 5 becomes higher than a predetermined value, the pressurized air in the air tank is sent to the ejector 30. Thereby, the negative pressure within the receiver tank 5 is further increased due to the ejector effect. Further, a large amount of air is supplied to the water ring pump 25 from the ejector 30. Since the pressurized air ejected from the ejector 30 expands and its temperature drops when the pressure decreases, a large amount of cold air is supplied to the water ring pump 25. This makes it possible to suppress an increase in the temperature of the seal water in the water ring pump 25, and eliminates concerns about cavitation.

The air sucked into the water ring pump 25 is discharged from the discharge port 25b, passes through the quaternary catcher 22, returns to the air switching type four-way valve 24, passes through the integrated silencer 23, and is exhausted to the outside.

On the other hand, when switching from suction to centering, the operator presses the centering button 15b on the operation panel 15. Then, the spool of the air switching type four-way valve 24 returns to the center side due to the pressure of the pressurized air in the air tank.

When switching from medium pressure to pressure, the operator presses the pressure button 15c on the operation panel 15. Then, the spool of the air switching type four-way valve 24 moves from the center side to the pressurizing side due to the pressure of the pressurized air in the air tank.

Next, the air switching type four-way valve 24 is switched to the state shown in FIG. It passes through the four-way valve 24, passes through the tertiary catcher 21 and the secondary catcher 20, reaches the receiver tank 5, and is discharged from the discharge port 9 together with the recovered object.

As shown in FIGS. 5 and 6, the tertiary catcher 21 and the quaternary catcher 22 of the suction device 1 are integrally provided. Specifically, the quaternary catcher 22 has a horizontal extension part 22b that partially extends in the horizontal direction, and the tertiary catcher 21 is provided inside the horizontal extension part 22b so as to penetrate in the vertical direction. There is.

Specifically, the quaternary catcher 22 has a cylindrical main body 22a extending in the vertical direction, communicates with the main body 22a internally, and protrudes in the left-right direction (vehicle width direction) from the side surface of the upper end of the main body 22a. It has a cylindrical horizontal extension part 22b. A cylindrical wash water tank 22c is integrally provided at the upper end of the main body 22a. Washing water stored in the washing water tank 22c can be sprayed onto the suction device 1 and its surroundings by a water pump 33 (see FIG. 7) for washing.

An air outlet (not shown) is provided on the upper end surface of the main body portion 22a, and this outlet is connected to one end of a fifth pipe 7e housed inside the wash water tank 22c. The fifth pipe 7e is cut off from the cleaning water storage section of the cleaning water tank 22c. The air inside the main body portion 22a is discharged to the air switching type four-way valve 24 side via the fifth pipe 7e.

Water is stored inside the main body portion 22a and the horizontal extension portion 22b, and the main body portion 22a and the horizontal extension portion 22b serve as a water tank for removing dust from the air that has passed through the water ring pump 25. An overflow port (not shown) is provided on the side surface of the main body portion 22a, and a portion from the bottom wall of the main body portion 22a and the horizontal extension portion 22b to the overflow port serves as a water storage portion. The height position of the overflow port is set to the maximum water level, and water is drained from the overflow port to prevent water from accumulating above this maximum water level. Note that a valve is attached to the overflow port to keep the interior of the quaternary catcher 22 airtight when the water is not drained.

A recessed portion 22h extending in the vertical direction is formed in the middle portion of the horizontally extending portion 22b in the left-right direction. A fourth pipe 7d connecting the air switching type four-way valve 24 and the water ring type pump 25 is disposed within this recess 22h.

A tertiary catcher 21 having a cylindrical outer circumferential wall extending in the vertical direction is inserted into the end of the horizontal extension 22b that is not connected to the main body 22a (the left end in FIG. 6, etc.). The tertiary catcher 21 is disposed vertically penetrating inside the horizontal extension portion 22b. Specifically, a pair of upper and lower through holes 22i are formed at the left end of the horizontal extension 22b, and the intermediate portion 21a of the tertiary catcher 21 is inserted into the upper and lower through holes 22i. The outer diameter of the intermediate part 21a of the tertiary catcher 21 and the inner diameter of the upper and lower through holes 22i substantially match, and the outer peripheral wall of the intermediate part 21a of the tertiary catcher 21 is welded to the inner peripheral edge of the upper and lower through holes 22i. They are connected by means such as In this way, the intermediate portion 21a of the tertiary catcher 21 is fixed to the horizontally extending portion 22b of the quaternary catcher 22, and the tertiary catcher 21 and the quaternary catcher 22 are integrated. The inside of the tertiary catcher 21 and the inside of the horizontal extension part 22b are cut off, so that water does not flow between the tertiary catcher 21 and the quaternary catcher 22. A cyclone type dust collection mechanism is provided inside the tertiary catcher 21. Note that a base portion 22l is provided at an intermediate portion of the upper portion of the horizontal extension portion 22b in the left-right direction. The integrated silencer 23 has its lower end attached to the base portion 22l of the horizontal extension 22b. The integrated silencer 23 is cut off from the inside of the horizontal extension portion 22b.

A space S1 is formed by the lower side surface of the main body portion 22a of the quaternary catcher 22, the bottom surface of the horizontal extension portion 22b, and the side surface of the lower portion 21b of the tertiary catcher 21 that projects downward from the horizontal extension portion 22b. A water ring pump 25 is arranged in this space S1.

The horizontal extension 22b is provided with an inlet (not shown) into which air sent from the discharge port 25b of the water ring pump 25 flows. The air entering from this inlet is sent to the inside of the main body part 22a through the inside of the horizontal extension part 22b, and is sent to the air switching type four-way valve 24 side through the above-mentioned fifth pipe 7e.

As shown in FIG. 7, the water pump 33 allows the cleaning water in the cleaning water tank 22c to be jetted out from the nozzle 33a. The water pump 33 is driven by a hydraulic motor 32 as a hydraulic actuator. The water flow path 34 from the wash water tank 22c to the nozzle 33a is provided with a filter, an unload valve, a shutoff valve, etc. in addition to the water pump 33. Further, the water flow path 34 is connected to an oil cooler 35.

The hydraulic motor 32 is connected to a hydraulic control circuit C1. By driving the hydraulic pump 26 by the engine E, hydraulic oil in the oil reservoir 31 can be supplied to the hydraulic motor 32 via the hydraulic control circuit C1. Moreover, the hydraulic oil of the hydraulic motor 32 can be discharged to the oil reservoir 31 via the hydraulic control circuit C1. An oil cooler 35 for suppressing a rise in temperature of the hydraulic oil is provided in a discharge oil path 36 that returns the hydraulic oil from the hydraulic control circuit C1 to the oil reservoir 31.

In this embodiment, the oil cooler 35 is provided integrally with the oil reservoir 31. A cylindrical body portion 35a (see FIG. 1) extending in the longitudinal direction of the oil cooler 35 is inserted into the oil reservoir 31. One end of the main body 35a of the oil cooler 35 is directly attached to the oil reservoir 31 so as to protrude inward from the oil reservoir 31.

A discharge oil path 36 is connected to the oil cooler 35, so that the hydraulic oil returned from the hydraulic control circuit C1 flows into the main body portion 35a of the oil cooler 35. Note that the hydraulic oil can be directly discharged from the oil cooler 35 to the oil reservoir 31, and no piping is provided for discharging the hydraulic oil from the oil cooler 35 to the oil reservoir 31.

The oil cooler 35 is also connected to the water passage 34 described above, so that the wash water in the wash water tank 22c flows into the main body 35a of the oil cooler 35. The oil cooler 35 is interposed in the water flow path 34 between the wash water tank 22c and the water pump 33. Cleaning water sucked up from the cleaning water tank 22c by the water pump 33 can be supplied into the main body 35a of the oil cooler 35. Thereby, heat exchange is performed between the wash water supplied from the wash water tank 22c and the hydraulic oil returned from the hydraulic control circuit C1. The hydraulic oil returned from the hydraulic control circuit C1 is cooled by the cleaning water supplied from the cleaning water tank 22c, and the cooled hydraulic oil is returned to the oil reservoir 31. On the other hand, the wash water after the heat exchange is sent to the water pump 33, then is pumped by the water pump 33, and is injected from the nozzle 33a.

In this embodiment, as described above, the working fluid for heat exchange supplied to the oil cooler 35 is the wash water in the wash water tank 22c. A working fluid passage formed inside the oil cooler 35 through which the working fluid flows is constituted by a part of the water passage 34.

According to this embodiment, the temperature rise of the hydraulic oil of the hydraulic motor 32 that drives the water pump 33 can be suppressed with a compact and low-cost configuration. Specifically, since the oil cooler 35 can cool the hydraulic oil of the hydraulic motor 32 that drives the water pump 33, it is possible to prevent equipment failure due to an increase in the temperature of the hydraulic oil. In addition, since the cleaning water that is force-fed from the cleaning water tank 22c to the nozzle 33a is used as the working fluid for the oil cooler 35, compared to the case where a dedicated working fluid is used, the equipment around the oil cooler 35 is Simplification can be achieved, and as a result, the entire apparatus can be made compact, and the cost of the apparatus can also be reduced.

Further, the oil cooler 35 is attached to the oil reservoir 31 in such a way that one longitudinal end thereof protrudes inward of the oil reservoir 31, so that the oil cooler 35 and the oil reservoir 31 are integrated. It is set in. By integrating the oil cooler 35 and the oil reservoir 31 in this way, the oil cooler 35 and the oil reservoir 31 can be arranged separately on the chassis 3. Connecting piping and installation space can be reduced. This makes it possible to provide a compact and low-cost suction wheel 2.

In addition, the oil cooler 35 is interposed between the wash water tank 22c and the water pump 33 in the water flow path 34, so that the unused low-temperature wash water in the wash water tank 22c is heated to a high temperature. It can be used as a working fluid for the oil cooler 35 before passing through the water pump 33, which can further enhance the cooling effect of the oil cooler 35.

The embodiments disclosed this time are illustrative in all respects and are not the basis for restrictive interpretation. The technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the claims. Further, the technical scope of the present invention includes all changes within the meaning and scope equivalent to the scope of the claims.

In the embodiment described above, the wash water tank 22c is provided integrally with the quaternary catcher 22, but the wash water tank may be provided separately from the quaternary catcher 22.

In the above embodiment, the water ring pump 25 is used as the vacuum pump, but other vacuum pumps may be used. Note that when the water ring pump 25 is used as the vacuum pump, since water forms a part of the pump, it has many advantages such as being clean and quiet, having no metal contact, and not requiring oil. Furthermore, since there is a large gap between the impeller and the casing, it has the advantage of being resistant to foreign objects, and it also has the advantage of being less likely to seize because it will no longer function as a pump when water runs out.

In the above embodiment, the tertiary catcher 21 and the quaternary catcher 22 are provided integrally, but the tertiary catcher 21 and the quaternary catcher 22 may be provided separately. Further, although the integrated silencer 23 is provided integrally with the tertiary catcher 21 and the quaternary catcher 22, the silencer may be provided separately from the tertiary catcher 21 and the quaternary catcher 22.

Although the present invention has been described above for a case where it is applied to a suction vehicle, the present invention can also be applied to various work vehicles as long as they are equipped with a hydraulically driven water pump that pumps water from a wash water tank. is possible.

INDUSTRIAL APPLICATION This invention can be utilized for the work vehicle equipped with the hydraulically driven water pump which pumps the water of a wash water tank.

1 Suction device 2 Suction vehicle (work vehicle)
22c Cleaning water tank 31 Oil reservoir (hydraulic oil tank)
32 Hydraulic motor (hydraulic actuator)
33 Water pump 34 Water flow path 35 Oil cooler 35a Main body

Claims (2)

wash water tank,
a water flow path for spouting water from the cleaning water tank from a nozzle;
a water pump that is installed in the water flow path and pumps water;
a hydraulic actuator that drives the water pump;
a hydraulic oil tank that stores hydraulic oil for the hydraulic actuator;
A work vehicle comprising an oil cooler for suppressing a temperature rise of the hydraulic oil,
A working fluid flow path for flowing the working fluid of the oil cooler is constituted by a part of the water flow path ,
The oil cooler is interposed between the wash water tank and the water pump in the water flow path,
The working vehicle is characterized in that the working fluid is water that is pumped from the wash water tank to the nozzle by driving the water pump . The work vehicle according to claim 1,
The oil cooler is attached to the hydraulic oil tank with one longitudinal end thereof protruding inward of the hydraulic oil tank, and the oil cooler and the hydraulic oil tank are integrally provided. A work vehicle characterized by:

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