JP2009214599A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working vehicle capable of providing stable electric power, without requiring to switch the connection of an apparatus connected to a PTO shaft or the like. <P>SOLUTION: This working vehicle is mounted with an engine, and travels by rotating wheels by its rotational driving force, and is constituted so that the PTO shaft 16 is arranged for taking out the rotational driving force of the engine except for rotation of the wheels, and the PTO shaft 16 is connected with an input shaft of AC generators 22a and b via a first speed increaser 21, and output of the AC generators 22a and b is converted into AC electric power by inverter devices 32a and b after being converted into a direct current by rectifiers 31a and b, and its AC electric power is outputted to an external part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a working vehicle that is equipped with an engine and travels by rotating wheels by its rotational driving force.

  Traditionally, working vehicles such as tank trucks, ladder cars, rescue work vehicles, and work vehicles including fire pumps are used for tasks such as fire fighting and rescue in the field of accidents, fires, and other disasters. It is utilized. These work vehicles are rushed to the site with high capacity, and after arriving at the site, they can be used in a stationary state to achieve the maximum objectives.

  Such a working vehicle is provided with one or a plurality of PTO shafts for taking out the rotational driving force of the engine other than the rotational driving of the wheels.

  Conventionally, these PTO shafts are equipped with a 4-pole AC generator, a hydraulic pump, etc., rotating these AC generators and hydraulic pumps by the rotational driving force of the engine, and taking out AC power of 50 Hz or 60 Hz, The pressure oil is taken out. In that case, if the engine speed fluctuates, the frequency of the AC power fluctuates, and the pump discharge amount, discharge pressure, etc. fluctuate, so the engine is operated at a constant speed. There is a need.

  On the other hand, in Patent Document 1, the priority device to be preferentially operated and other devices are driven by the PTO shaft attached to the traveling engine, and the engine is adjusted by voltage adjustment of a voltage regulator provided for each device. An apparatus is disclosed in which the engine speed is controlled via a control unit, and the connection of the voltage regulator for priority equipment and the voltage regulator for other equipment to the engine control unit can be switched alternately.

Further, in Patent Document 2, in a work vehicle that is driven by controlling the rotational speed of a traveling engine by a voltage signal output from an ECU, a crane transmits a voltage signal proportional to a throttle amount from an accelerator sensor to the ECU. On the other hand, the generator and the winch send a voltage signal preset in the voltage control circuit to the ECU to control the rated rotation, and the connection of the voltage control circuit to the ECU is connected to the accelerator sensor via the switching relay. And the generator is preferentially connected to other devices.
JP2003-24461 JP-A-2004-68728

  However, according to the above-mentioned conventional documents, it is necessary to switch and disconnect the devices alternately, which is troublesome and the frequency of generated power fluctuates if the operation is wrong. In addition, the hydraulic pressure may fluctuate.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a working vehicle that can obtain stable power without the need to switch the connection of devices connected to a PTO shaft or the like. And

  A working vehicle according to the present invention is a working vehicle that is equipped with an engine and travels by rotating a wheel with its rotational driving force, and a PTO shaft for taking out the rotational driving force of the engine other than the rotation of the wheel An input shaft of an alternator is connected to the PTO shaft through a speed increaser, and the output of the alternator is converted into direct current by a rectifier and then converted into direct current by an inverter device. It is converted into AC power and the AC power is output to the outside.

  In another embodiment, a main PTO shaft and a side PTO shaft for taking out the rotational driving force of the engine other than the rotation of the wheel are provided, and a first speed increaser is provided on the main PTO shaft. The input shaft of the AC generator is connected to the AC generator, and the output of the AC generator is converted to DC power by a rectifier and then converted to AC power by an inverter device so that the AC power is output to the outside. An input shaft of a variable displacement hydraulic pump is connected to the side PTO shaft via a second speed increaser, and pressure oil discharged from the hydraulic pump is output to the outside. And the discharge flow rate of the hydraulic pump is controlled to be constant with respect to fluctuations in the rotational speed of the engine.

  Preferably, the first gearbox and the AC generator are unitized.

  Preferably, the lower limit of the rotational speed of the engine is set to 1000 RPM or more, the speed increase ratio of the first speed increaser is 2.5 times or more, and the speed increase speed of the second speed increaser is increased. The ratio is 1.6 times or more.

  More preferably, a plurality of alternators are provided as the alternator, and the outputs of the respective alternators are combined after being converted into direct current by a rectifier.

  According to the present invention, it is not necessary to switch the connection of devices connected to a PTO shaft or the like, and stable power can be obtained.

  FIG. 1 is a view showing the appearance of a working vehicle 1 according to the present invention, FIG. 2 is a view showing the periphery of the engine 11, FIG. 3 is a block diagram showing an electric circuit of a power generation system 30, and FIG. It is a block diagram which shows the hydraulic circuit.

  In FIG. 1, the working vehicle 1 travels by rotating wheels 13 via a propulsion shaft 15 by the rotational driving force of an engine 12 mounted on a body 11.

  Referring also to FIGS. 2 to 4, the engine 12 is provided with a main PTO shaft 16 and a side PTO shaft 17 for taking out the rotational driving force other than the rotation of the wheel 13.

  An input shaft of an AC generator 22 is connected to the main PTO shaft 16 via a first speed increaser 21. A plurality of AC generators can be provided as the AC generator 22. In the present embodiment, two AC generators 22 a and 22 b are provided as the AC generator 22. Then, the outputs of the respective AC generators 22a and 22b are combined after being converted into direct current by a rectifier.

  That is, the outputs PV1a and b of the AC generators 22a and 22b are synthesized after being converted into DC power PV2 by the rectifiers 31a and b, and the synthesized DC power PV2 is synthesized by the inverter devices 32a and b. It is converted into b and the AC power PV3 is output to the outside.

  An input shaft of a variable displacement hydraulic pump 24 is connected to the side PTO shaft 17 via a second speed increaser 23. A plurality of hydraulic pumps can be provided as the hydraulic pump 24. In the present embodiment, two hydraulic pumps 24 a and 24 b are provided as the hydraulic pump 24. The pressure oil discharged from the hydraulic pumps 24a and 24b is output to the outside through a hydro unit 41 having various valves and manifolds. The discharge flow rate of the hydraulic pumps 24a and 24b is controlled by feedback from the hydro unit 41, so that the discharge flow rate or discharge pressure of the hydraulic pumps 24a and 24b becomes constant with respect to fluctuations in the rotational speed of the engine 12. Is controlled.

  The first speed increaser 21 has a speed increase ratio of 2.5 times or more, for example, 2.5 times or 3 times. The second speed increaser 23 has a speed increase ratio of 1.6 times or more, for example, 1.6 times or more, and may be 2 times.

  When the working vehicle 1 is working, the lower limit of the rotational speed SV1 of the engine 12 is set to 1000 RPM or more.

  Further, the first speed increaser 21 and the AC generators 22a and 22b are unitized and integrated. The second speed increaser 23 and the hydraulic pumps 24a and 24b are also unitized and integrated. By making such a unit, it becomes easy to provide a necessary number of necessary units in the work vehicle 1. For example, it is easy to use these units in a manner such as solo (single), multi (multiple), and mixing (mixed), and an optimum system according to the use and scale of the work vehicle 1. Can be built.

  As described above, the power generation system 30 including the AC generator 22 is an alternator system, and the hydraulic system 40 including the hydraulic pump 24 is a load sensing system, and an AC generator is used for the rotational driving force of the engine 12. 22 and hydraulic pump 24 operate most efficiently.

  Further, even if the load of the engine 12 is multiple, a lower limit is provided for the rotational speed SV1 of the engine 12 so that the load priority problem does not occur, so that the rotational speed SV1 of the engine 12 does not fall below the lower limit. Acceleration control or throttle control corresponding to load is performed. That is, in the present embodiment, as described above, the lower limit of the rotational speed SV1 of the engine 12 is set to 1000 RPM, and control is performed so that the rotational speed SV1 is higher than this.

  At the lower limit rotational speed SV1, the AC generator 22 can supply the minimum necessary electric power to the load, and the hydraulic pump 24 can supply the pressure oil of the minimum necessary pressure to the load. Moreover, the AC generator 22 is actually increased by using the first speed increaser 21 and the hydraulic pump 24 by using the second speed increaser 23 to increase the rotation speed. The AC generator 22 rotates at a minimum of 2500 RPM, and the hydraulic pump 24 rotates at a minimum of 1600 RPM. Therefore, when the rotational speed of the engine 12 increases, for example, doubles, the AC generator 22 rotates in the range of 2500 to 5000 RPM, and the hydraulic pump 24 rotates in the range of 1600 to 3200 RPM. For this reason, the AC generator 22 and the hydraulic pump 24 are operated at the most efficient rotational speed, and efficient outputs can be obtained respectively.

  Incidentally, in the past, for example, when a 4-pole AC generator is used, the AC output is used as it is, so the rotational speed of the AC generator is 1500 RPM (in the case of 50 Hz) or 1800 RPM (in the case of 60 Hz). It was necessary to give priority to this even in the case of multiple loads, and the rotational speed of the engine 12 had to be adjusted to this.

  In the present embodiment, it is not necessary to determine priority (designated rotational speed) for the rotational speed between the AC generator 22 and the hydraulic pump 24.

  Moreover, in this embodiment, by using two AC generators 22a and 22b as the AC generator 22, the required power can be obtained by the two small and light AC generators 22a and 22b. It is possible to reduce the overall shape and size and reduce the weight. Therefore, it is possible to reduce the required space for the power generation system 30 and the hydraulic system 40 in the work vehicle 1 and to load more fire fighting equipment and the like on the work vehicle 1 by the amount of space saving.

  Further, since energy saving is achieved by improving the efficiency of the power generation system 30 and the hydraulic system 40, it can be said that these are environment-friendly systems as a whole.

  The work vehicle 1 can be roughly divided into a work vehicle such as a tank car, a ladder car, a rescue work car, and a pump car such as a fire fighting pump car. In the case of a work vehicle, both the main PTO shaft 16 and the side PTO shaft 17 are used as load distribution, and the system shown in FIGS. 3 and 4 is configured, for example. In the case of a pump car, the main PTO shaft 16 is used for missions as a pump car, so the side PTO shaft 17 is used for power generation and hydraulic pressure. In this case, for example, the system shown in FIG.

  For example, when the work vehicle 1 is a firefighting pump car, the rotational speed SV1 of the engine 12 is varied according to the amount of water discharged so that the maximum capability can be exhibited in the fire fighting mission activity. Accordingly, the rotational speed SV1 of the engine 12 is constantly changing during the fire fighting mission activity. Under such conditions, in order to obtain a stable output of, for example, 5.5 KVA as the AC power PV3, the lower limit of the rotational speed SV1 of the engine 12 is set to 1000RP, thereby ensuring the power generation capability. Keep it. The alternator type power generation system 30 absorbs the fluctuation of the rotational speed SV1 of the engine 12 according to the fire fighting mission activity, and always supplies an appropriate AC power PV3 to the load.

  In FIG. 2, a rotational driving force is transmitted between the main PTO shaft 16 and the first speed increaser 21 by a connecting shaft 25 using a universal joint or the like. Similarly, a rotational driving force is transmitted to and from the speed increaser 23 by a connecting shaft 26 using a universal joint.

  The power generation system 30 will be described in more detail.

  In FIG. 3, each of the rectifiers 31a and 31b of the power generation system 30 is a three-phase full-wave rectifier by, for example, a bridge connection of six diodes, and a capacitor C1 is provided for smoothing the output. The rectifiers 31a and 31b are each provided with an IC regulator for stabilizing the output voltage as necessary. The DC power PV2 output from the rectifiers 31a and 31b is, for example, DC 280V. Even if there is a difference between the outputs of the two rectifiers 31a and 31b, there is no backflow due to the nature of the rectifiers 31a and 31b.

  The inverter devices 32a and 32b output 50V or 60Hz single-phase or three-phase 200V AC power PV3a and b by DC 280V input. The single-phase AC power PV3a is supplied to an igniter 34 of a lighting device 35 such as a discharge lamp via a ballast 33, and the voltage is lowered to 100V by a transformer 36 and supplied to various electric devices. The three-phase AC power PV3b is supplied to the AC motor 37, and the compressor 38 and the like are driven by the rotational driving force to obtain compressed air and the like.

  The output of the inverter devices 32a and 32b is about 5 to 10KVA. The inverter devices 32a, b can be turned on or off by switches SW1a, b, respectively. The output frequency can also be switched.

  By the way, the alternating current generators 22a and 22b of the power generation system 30 of the present embodiment are of an alternator system (ATG) as described above. The power generation system 30 converts the rotational kinetic energy of the engine 12 into alternating electrical energy. The AC generators 22a and 22b and the rectifiers 31a and 31b used here may be referred to as “alternators” including IC regulators and the like. Further, as the AC generators 22a and 22b, it is possible to use a rotary field type electromagnetic synchronous generator that uses a magnetic field as a rotor and extracts three-phase AC power from a stator armature. Stable DC power PV2 is obtained by the combination of the AC generators 22a, 22b and the rectifiers 31a, 31b. That is, even when the rotational speed of the main PTO shaft 16 fluctuates, stable DC power PV2 can be obtained. By converting this DC power PV2 into AC power PV3a, b using inverter devices 32a, b, AC power PV3a, b having a stable frequency and voltage can be obtained.

  In such an alternator type power generation system 30, the overall size (volume) and weight can be greatly reduced as compared with other types. Since it is converted to DC power PV2 by the rectifiers 31a and 31b, it is hardly affected by the output quality of the AC generators 22a and 22b. That is, the tolerance of voltage, voltage waveform, frequency, etc. is large, and efficiency is achieved even by random power generation. Good power can be obtained.

Moreover, since the direct-current power PV2 is converted into the alternating-current power PV3a, b using the inverter devices 32a, b, the following effects are obtained.
(1) Switching between 50 Hz and 60 Hz is easy.
(2) A good voltage waveform is obtained as the AC power PV3.
(3) Less affected by system mechanical noise.
(4) At the stage of the DC power PV2, the plurality of inverter devices 32a and 32b can be easily operated in parallel (pararun) only by combining the plus and minus phases and the voltage.
(5) Moreover, optimal AC power PV3a, b can be supplied by arranging inverter devices 32a, b for each type of load for a plurality of types of loads for AC.
(6) Stable power can be supplied by incorporating a backup circuit against sudden load fluctuations and instantaneous disconnection.
(7) As long as the minimum power (horsepower) is ensured, the engine 12 does not interfere with the operation of the power generation system 30 and the hydraulic system 40 even when the rotational speed SV1 fluctuates greatly. It is possible.
(8) When the load is a discharge lamp (discharge lamp), flicker (flicker) is likely to occur due to the influence of noise, but it is difficult to generate flicker by using the inverter devices 32a and 32b.

  Next, the hydraulic system 40 will be described in detail.

  In FIG. 4, the pressure oil output from the hydro unit 41 is supplied to a crane unit 42, an auto lucas 43, a rocker winch 44, and a super spray 45. In addition, you may supply pressure oil to units or apparatuses other than these.

  In FIG. 4, the hydraulic pumps 24 a and 24 b of the hydraulic system 40 are a load sensing type (load balance type) oil hydraulics power matching system.

  When the load sensing type hydraulic system 40 of the present embodiment uses, for example, a hydraulic motor or a hydraulic cylinder as a load, the actual working pressure at the load is fed back to the variable displacement hydraulic pumps 24a, 24b. The hydraulic pumps 24a and 24b discharge and supply only the amount of oil used in the hydraulic actuator. That is, the hydraulic system 40 is a closed circuit as a whole, and is a total energy-saving hydraulic system that supplies pressure oil at a flow rate necessary for a load and does not cause pressure oil to be wasted.

  That is, for example, the pressure of one point where the highest pressure is applied among the used hydraulic actuators is fed back to the hydraulic pumps 24a and 24b. Accordingly, the hydraulic pumps 24a and 24b use the feedback pressure to discharge the pressure oil having the pressure PH1 (Pf + PA) obtained by adding the predetermined pressure PA to the feedback pressure Pf. The hydraulic pumps 24a and 24b discharge an oil amount equivalent to the oil amount used on the hydraulic actuator side. As such hydraulic pumps 24a and 24b, for example, swash plate type variable displacement plunger pumps or the like are used.

  As described above, the hydraulic system 40 is the best energy-saving hydraulic system when the simultaneous use conditions of a plurality of hydraulic actuators that are loads cannot be determined or when the combination thereof is complicated. it can.

  In addition, the example of the specification of the apparatus used as a load with the hydraulic system 40 is given next.

Front winch ... 6MPa, 15L / min
Crane: 8MPa, 20L / min
Hydraulic pump ...... 9MPa, 35L / min (8ps)
Maximum output 21.5MPa, 85L / min (45ps)
Next, an example of unitization with the first speed increaser 21 and the AC generators 22a and 22b will be described.

  5 is a front view of the power generation unit UG1, FIG. 6 is a plan view of the power generation unit UG1, and FIG. 7 is a right side view of the power generation unit UG1. In addition, these figures are figures which show schematic structure, and there is also a part with which illustration was abbreviate | omitted.

  5 to 7, in the power generation unit UG <b> 1, a shaft 53 is rotatably attached to a bearing 52 attached to a base 51. A pulley 54 is attached to the shaft 53, and one end of the shaft 53 is connected to the connecting shaft 25 described above by a universal joint (not shown).

  Two AC generators 22a and 22b are attached to the bracket 55 attached to the base 51, and pulleys 56a and 56b are attached to the input shafts of the AC generators 22a and 22b. Belts 57a and 57b are stretched between the pulley 54 and the pulleys 56a and 56b, respectively. The ratio of the diameters of the pulley 54 and the pulleys 56a and 56b is 2.5 to 1, and thereby the rotational speed of the shaft 53 is increased by 2.5 times. The shaft 53, the pulley 54, the pulleys 56a and 56b, the belts 57a and 57b, and the like constitute the first speed increaser 21. By changing the ratio of the diameters of the pulley 54 and the pulleys 56a and 56b, a speed increaser with an arbitrary magnification can be obtained.

  The power generation unit UG1 is directly attached to the chassis or the like of the body 11 of the work vehicle 1 with bolts or the like, and is connected to the connection shaft 25 described above.

  Next, an example in which the power generation system 30B and the hydraulic system 40B are configured using only the side PTO shaft 17 when the work vehicle 1 is, for example, a fire pump car will be described.

  FIG. 8 is a block diagram showing an electric circuit of the power generation system 30B and a hydraulic circuit of the hydraulic system 40B. In FIG. 8, the same functions as those of the power generation system 30 or the hydraulic system 40 shown in FIGS. 3 and 4 may be denoted by the same reference numerals, or “B” may be added to the end of the same reference numerals. .

  In FIG. 8, an AC generator 22B and a variable displacement hydraulic pump 24B are connected to a speed increaser 23B to which a rotational driving force is transmitted by a connecting shaft 26. The speed increase ratio of the speed increaser 23B is, for example, 3 times on the AC generator 22B side and 2 times on the hydraulic pump 24B side. These speed increasing ratios may be values other than this value, or may be the same as each other.

  The output PV1 of the AC generator 22B is converted into DC power PV2 by the rectifier 31B, and the DC power PV2 is converted into AC power PV3a, b by the inverter devices 32a, b. The AC power PV3a is supplied to the lighting devices 35Ba, b via the ballasts 33Ba, b and the igniters 34Ba, b. The AC power PV3b is supplied to the AC motor 37B, and drives the compressor 38B by its rotational driving force.

  The pressure oil discharged from the hydraulic pump 24B is supplied to the front winch 46 through the hydro unit 41B. The discharge flow rate of the hydraulic pump 24B is controlled by feedback from the hydro unit 41B, and thereby the discharge flow rate or discharge pressure from the hydro unit 41B is controlled to be constant with respect to fluctuations in the rotational speed of the engine 12. ing.

  As described above, according to the working vehicle 1, the power generation systems 30, 30B, and the hydraulic systems 40, 40B of the present embodiment, it is necessary to switch the connection of devices connected to the main PTO shaft 16, the side PTO shaft 17, and the like. And stable power and stable pressure oil can be obtained.

  In the embodiment described above, the lower limit of the rotational speed SV1 of the engine 12 is 1000 RPM, the speed increase ratio of the first speed increaser 21 is 2.5 times or more, and the speed increase of the second speed increaser 23 is increased. The ratio was 1.6 times or more. Thereby, the AC generator 22 rotates at 2500 RPM or more, and the hydraulic pump 24 rotates at 1600 RPM or more. For example, when the engine 12 rotates in the range of 1000 to 3000 RPM, the AC generator 22 rotates in the range of 2500 to 7500 RPM, and the hydraulic pump 24 rotates in the range of 1600 to 4800 RPM. Thereby, all of the engine 12, the AC generator 22, and the hydraulic pump 24 operate efficiently.

  However, the speed increasing ratios of the speed increasers 21, 23, and 23B can be variously changed according to the specifications of each device. For example, the speed increase ratio of the speed increaser 21 can be 2 times or more, the speed increase ratio of the speed increaser 23 can be 1.4 times or more, and the rotation speed of the engine 12 can be 1250 RPM. In this case, the AC generator 22 rotates at 2500 RPM or more, and the hydraulic pump 24 rotates at 1750 RPM or more. It is also possible to transmit the rotational speed of the engine 12 as it is to the AC generator 22 and the hydraulic pump 24 without using the speed increasers 21, 23, 23B, that is, without increasing the speed.

  Further, the number of AC generators 22a, 22b, the number of hydraulic pumps 24a, 24b, and the like can be variously changed in addition to those described above. Instead of the hydraulic pump 24, a hydraulic pump or other various fluid pressure devices can be used. Various devices other than those described above can be used as the load of the power generation system 30 or the hydraulic system 40. The power generation unit UG1 is not limited to the one described above, and can have various shapes and structures.

  In addition, the structure, shape, dimensions, number, material, power value, specifications, etc. of the whole or each part of the power generation unit UG1, the power generation system 30, the hydraulic system 40, or the work vehicle 1 are appropriately changed in accordance with the spirit of the present invention. can do.

It is a figure which shows the external appearance of the working vehicle which concerns on this invention. It is a figure which takes out and shows the circumference of an engine. It is a block diagram which shows the electric circuit of an electric power generation system. It is a block diagram which shows the hydraulic circuit of a hydraulic system. It is a front view of a power generation unit. It is a top view of a power generation unit. It is a right view of a power generation unit. It is a block diagram which shows the electric circuit of an electric power generation system, and the hydraulic circuit of the hydraulic system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Work vehicle 12 Engine 13 Wheel 16 Main PTO shaft 17 Side PTO shaft 21 1st speed-up gear 22a, b AC generator 23 2nd speed-up gear 24a, b Hydraulic pump 30,30B Power generation system 31 Rectifier 32 Inverter Devices 40, 40B Hydraulic system 41 Hydro unit 53 Shaft 54 Pulley 56 Pulley 57 Belt UG1 Power generation unit

Claims (5)

A working vehicle equipped with an engine and running by rotating wheels by its rotational driving force,
A PTO shaft for taking out the rotational driving force of the engine other than the rotation of the wheel is provided,
An input shaft of an alternator is connected to the PTO shaft through a speed increaser,
The output of the AC generator is converted to AC power by an inverter device after being converted to DC by a rectifier, and the AC power is output to the outside.
A working vehicle characterized by that. A working vehicle equipped with an engine and running by rotating wheels by its rotational driving force,
A main PTO shaft and a side PTO shaft for taking out the rotational driving force of the engine other than the rotation of the wheel are provided,
An input shaft of an alternator is connected to the main PTO shaft via a first speed increaser,
The output of the AC generator is converted to AC power by an inverter device after being converted to DC by a rectifier, and the AC power is output to the outside.
An input shaft of a variable displacement hydraulic pump is connected to the side PTO shaft via a second speed increaser, and the hydraulic oil discharged from the hydraulic pump is output to the outside. The pump discharge flow rate is controlled to be constant with respect to fluctuations in the rotational speed of the engine,
A working vehicle characterized by that. The first gearbox and the AC generator are unitized.
The work vehicle according to claim 2. The lower limit of the rotation speed of the engine is set to 1000 RPM or more,
The first speed increaser has a speed increase ratio of 2.5 times or more,
The second speed increaser has a speed increase ratio of 1.6 times or more.
The working vehicle according to claim 3. A plurality of alternating current generators are provided as the alternating current generator, and the outputs of the respective alternating current generators are synthesized after being converted into direct current by a rectifier,
The work vehicle according to claim 4.

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