JP7493447B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle.

Some work vehicles are equipped with a traveling body supported by a pair of left and right crawler traveling devices, a working unit provided at the front of the traveling body, and an engine provided on the traveling body. An example of this type of work vehicle is the grass cutter shown in Patent Document 1. The grass cutter is equipped with a grass cutting device as the working unit.

In the grass cutter shown in Patent Document 1, each of the pair of left and right crawler travel devices is provided with a hydraulic motor that drives the crawler travel device, and a hydraulic pump that is driven by the engine and supplies hydraulic oil to the hydraulic motor.

Japanese Patent Application Laid-Open No. 4-197104

Instead of the system shown in Patent Document 1, there is a demand for a configuration that allows the crawler travel device to be driven in a state where the engine power is efficiently transmitted to the crawler travel device.

The present invention provides a work vehicle that can not only efficiently transmit engine power to the crawler travel device, but also makes it easy to assemble the power transmission system.

The work vehicle according to the present invention comprises:
A traveling body supported by a pair of left and right crawler traveling devices, a working unit provided at the front of the traveling body, an engine provided on the traveling body, a transmission provided in front of or behind the engine and drivably supporting the drive wheels of the pair of left and right crawler traveling devices, a transmission case provided between the engine and the transmission and housing a gear interlocking mechanism that interlocks and connects an output shaft provided on the engine and an input shaft provided on the transmission, and a transmission case supported by the engine. a connecting mechanism, which has a connecting member formed as a separate member from the engine and the transmission case and interposed between the engine and the transmission case, a first fastener that fastens the connecting member to the engine, and a second fastener that fastens the transmission case to the connecting member , the connecting member being plate-shaped and having a through hole through which the output shaft is inserted, and the connecting member being configured so that the first fastener is attached to the edge of the through hole and the second fastener is attached to a portion of the connecting member closer to the outer periphery than the first fastener .

With this configuration, the power of the engine's output shaft is transmitted to the input shaft by the gear interlocking mechanism and input to the transmission, and the drive wheels of the left and right crawler traveling devices are driven by the transmission, so the engine's power can be efficiently transmitted to the left and right crawler traveling devices.

The transmission case can be assembled to the engine by adopting an assembly method in which the connecting member is connected to the engine with a first fastener, and then the transmission case is connected to the connecting member with a second fastener, making it easy to assemble the transmission case to the engine.
According to this configuration, when connecting the transmission case to the connecting member which is connected to the engine, the second fastener is attached to a portion of the connecting member which is located closer to the outer periphery of the connecting member than the first fastener which is already attached. Therefore, the second fastener can be attached without the first fastener interfering with the attachment of the second fastener, making it easier to connect the transmission case to the connecting member.

Another work vehicle according to the present invention includes:
The vehicle comprises a traveling body supported by a pair of left and right crawler traveling devices, a working unit provided at the front of the traveling body, an engine provided on the traveling body, a transmission provided in front of or behind the engine and drivably supporting drive wheels of the pair of left and right crawler traveling devices, a transmission case provided between the engine and the transmission and accommodating a gear interlocking mechanism that interlocks and connects an output shaft provided on the engine and an input shaft provided on the transmission, and a connecting mechanism that supports the transmission case on the engine, the connecting mechanism being different from the engine and the transmission case. The transmission case has a connecting member formed as a separate member and interposed between the engine and the transmission case, a first fastener for fastening the connecting member to the engine, and a second fastener for fastening the transmission case to the connecting member, wherein the input shaft is positioned at a higher position than the output shaft, and the transmission case has an engine side portion formed on a lower portion of the transmission case to which the output shaft is connected, and a transmission side portion formed on an upper portion of the transmission case to which the input shaft is connected, and the connection between the transmission case and the connecting member by the second fastener is made only on the engine side portion of the engine side portion and the transmission side portion.

With this configuration, the transmission case can be quickly assembled to the engine by simply connecting only the engine side of the transmission case to the connecting member.

In the present invention,
It is preferable that the transmission case is divided into two split cases in a direction along the axis of the output shaft, and that the two split cases are configured to be connected by a third fastener that is different from the first fastener and the second fastener.

With this configuration, the transmission case can be connected to the connecting member while in an assembled state in which the two split cases are connected by the third fastener, making it easy to connect the transmission case to the connecting member.

In the present invention,
The gear interlocking mechanism is preferably configured to reverse the power of the output shaft and transmit it to the input shaft.

With this configuration, the power of the output shaft can be converted by the gear interlocking mechanism into power with the appropriate rotational direction to be input to the transmission, and then transmitted to the transmission.

FIG. 2 is a left side view showing the entire grass mower. FIG. 2 is a right side view showing the entire grass mower. FIG. 2 is a plan view showing the entire grass cutter. FIG. FIG. 2 is a right side view showing the prime mover and the traveling transmission device. FIG. 2 is a plan view showing the prime mover and the traveling transmission device. FIG. 4 is a left side view showing the cooling air intake portion. FIG. 2 is a front view of the engine with a connecting member and a transmission case removed. FIG. 2 is a front view of the engine with the connecting member attached. FIG. FIG. 2 is a front view of the engine with the connecting member and the transmission case attached. FIG. 2 is a schematic diagram showing a traveling transmission device and a working transmission device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the following description, with regard to the running body of a grass cutter (an example of a work vehicle), the direction of arrow F shown in Figures 1, 2 and 3 is referred to as the "forward direction of the body", the direction of arrow B is referred to as the "rearward direction of the body", the direction of arrow U shown in Figures 1, 2 and 4 is referred to as the "upward direction of the body", the direction of arrow D is referred to as the "downward direction of the body", the direction of arrow L shown in Figures 3 and 4 is referred to as the "leftward direction of the body", and the direction of arrow R is referred to as the "rightward direction of the body".

[Overall configuration of the grass cutter]
As shown in Figs. 1, 2 and 3, the grass cutter includes a traveling body 2 supported by a pair of left and right crawler traveling devices 1. A grass cutter 3 is provided as a working unit at the front of the traveling body 2. A motive power unit 5 having an engine 4 is provided at the rear of the traveling body 2. The left and right crawler traveling devices 1 are driven by power transmitted from the engine 4 through a traveling transmission device 6 provided across the crawler traveling devices 1 and the engine 4. The grass cutter 3 is driven by power transmitted from the engine 4 through a work transmission device 7 connected to the side of the grass cutter 3. The traveling body 2 is equipped with a control device (not shown) that controls the crawler traveling device 1 and the grass cutter 3. The control device is configured to receive control commands from a radio control device (not shown) and to perform operations such as steering the traveling body 2 and driving and stopping the grass cutter 3 based on the received control commands. The grass cutter is configured to be remotely controlled by the radio control device. The grass cutter is configured as a so-called radio-controlled grass cutter.

[Configuration of the crawler traveling device]
As shown in Figs. 1 and 2, the left and right crawler traveling devices 1 are provided with track frames 10 extending in the front-rear direction of the traveling machine body 2. The track frames 10 are supported on the lower part of the machine body frame 8. Ground contact wheels 11 are rotatably supported at three locations aligned in the front-rear direction of the track frame 10. A tension wheel 12 is provided behind the rearmost ground contact wheel 11 of the three ground contact wheels 11. The tension wheel 12 is rotatably supported at the rear of the track frame 10. A drive wheel 13 is provided above the center of the track frame 10 in the front-rear direction. The drive wheel 13 is drivably supported by a transmission 20 provided in the traveling transmission device 6. A crawler belt 14 is wound around the three ground contact wheels 11, the tension wheel 12, and the drive wheel 13.

[Configuration of the grass cutting device]
1, 2 and 3, the grass cutting device 3 is connected to the machine body frame 8 via a lifting connection mechanism 30, and is provided on the traveling machine body 2 in a state in which it can swing up and down around a lifting axis P extending in the width direction of the traveling machine body 2 as a swing fulcrum. A lifting cylinder 35 is connected to a rear frame 40 provided at the rear of the grass cutting device 3 and a cylinder support part 8a provided on the machine body frame 8. The grass cutting device 3 is raised and lowered by the extension and contraction of the lifting cylinder 35.

As shown in Figures 1, 2, and 3, the lifting connection mechanism 30 includes a connection link 31 that connects the right side of the grass cutting device 3 to the machine frame 8, and a left connection part 32 that connects the left side of the grass cutting device 3 to the machine frame 8.

As shown in Figures 2 and 3, the connecting link 31 is connected to the rear frame 40 provided at the rear of the grass cutting device 3 and the link support part 8b provided on the machine frame 8. The connecting link 31 is supported by the link support part 8b in a state in which it can swing up and down with the lifting axis P as the swing fulcrum.

The left connecting part 32 includes a transmission tube 33 supported on the front part of the machine frame 8 while extending in the width direction of the traveling machine body 2, and a transmission case 34 connected to the left end part of the transmission tube 33 and the left side part of the grass cutting device 3. The transmission case 34 is supported by the transmission tube 33 in a state in which it can swing up and down with the lifting axis P as a swing fulcrum.

As shown in Figs. 1, 2 and 3, the grass cutting device 3 has a blade housing 41. Inside the blade housing 41, a blade 43 having a support shaft 42 extending in a direction along the width direction of the traveling body 2 is provided. Ground gauge wheels 44 are provided at two locations on the left and right of the front part of the blade housing 41. The two left and right ground gauge wheels 44 are provided in a state in which they are in contact with the ground forward of the blade housing 41. The blade 43 is provided in a state in which it can rotate around the axis of the support shaft 42. A knife blade 45 is provided on the outer periphery of the support shaft 42. The knife blades 45 are arranged in a direction along the axis of the support shaft 42 and in a circumferential direction of the support shaft 42. The grass cutting device 3 is configured as a flail mower, and cuts grass and crushes the cut grass using the knife blades 45.

[Configuration of the driving part]
As shown in Figures 1, 2 and 3, the prime mover 5 includes an engine 4, a fuel tank 9a for the engine provided above the engine 4, an air cleaner 9b for the engine provided on the side of the fuel tank 9a, and an exhaust muffler 9c for the engine provided on the side of the fuel tank 9a and forward of the air cleaner 9b.

The engine 4 is provided at the rear end of the traveling vehicle body 2. The engine 4 has a crankcase section 4a and a cylinder section 4b that extends laterally outward and diagonally upward from the crankcase section 4a. The crankcase section 4a has a flywheel section 4c formed at the rear of the crankcase section 4a. The engine 4 is supported by the vehicle frame 8 by connecting the lower part of the crankcase section 4a to an engine mounting section 8c provided on the vehicle frame 8.

[Configuration of cooling air introduction section]
The engine 4 is configured as an air-cooled type, and has a cooling air introduction section 50 that introduces engine cooling air. The cooling air introduction section 50 is provided in a state where it protrudes rearward from the traveling body 2 from the crankcase section 4a, which is the engine main body, as shown in Figures 5 and 7.

Specifically, as shown in FIG. 7, the cooling air introduction section 50 has a rotating fan 51, an air guide cover 52 positioned around the outer periphery of the rotating fan 51, and an intake cover 53 protruding rearward from the air guide cover 52.

The rotary fan 51 is integrally formed at the rear of the flywheel 54 of the engine 4 and is driven by the crankshaft 55. The air guide cover 52 is formed by a flywheel case. In this embodiment, the rotary fan 51 is integrally formed with the flywheel 54, but a rotary fan formed as a separate member from the flywheel 54 may also be used.

As shown in Figures 4, 5, and 7, the cooling air introduction section 50 is covered by a dustproof case 56. More specifically, the portion of the cooling air introduction section 50 where the intake cover 53 is located is covered by the dustproof case 56. The dustproof case 56 is provided with a number of ventilation holes 56a that allow the cooling air introduced by the cooling air introduction section 50 to flow into the dustproof case and prevent dust such as grass clippings that are mixed into the cooling air from flowing into the dustproof case. The dustproof case 56 removes dust from the cooling air introduced by the cooling air introduction section 50.

As shown in FIG. 7, a recoil starter device 57 that starts the engine 4 is provided inside the dustproof case 56. The recoil starter device 57 has a starter device main body 57a that is connected to the crankshaft 55 and is provided with a starting cable 58, and a starter case 59 that covers the starter device main body 57a. The intake cover 53 is formed by the starter case 59.

1, the starting rope 58 is pulled out to the outside of the dustproof case 56 through a through hole provided in the intake cover 53 and a through hole 56b provided in the dustproof case 56, and a starter grip 58a is provided at the end of the starting rope 58 located outside the dustproof case 56. As shown in FIG. 7, the dustproof case 56 has a vertical wall portion 56c and a side wall portion 56d extending forward from the periphery of the vertical wall portion 56c. The side wall portion 56d is provided around the entire circumference of the vertical wall portion 56c. The through hole 56b provided in the dustproof case 56 so that the starting rope 58 can be inserted is opened in the side wall portion 56d of the dustproof case 56. As shown in FIG. 1, the through hole 56b is configured as a notch hole so that the starting rope 58 naturally comes out of the through hole 56b to the notch opening side (front side) when the dustproof case 56 is removed. The cutout hole extends from the edge of the side wall 56d on the opening side of the dustproof case 56 toward the bottom side of the dustproof case 56.

As shown in FIG. 7, the dustproof case 56 is configured to be detachably supported by the support member 60. The support member 60 is attached to the air guide cover 52. The dustproof case 56 is detachably supported by the support member 60 by a connecting bolt that inserts the dustproof case 56 from the outside of the dustproof case 56 and engages it with the support member 60. The support member 60 has a base portion 60a onto which the side wall portion 56d of the dustproof case 56 is fitted, and an arm portion 60b that extends rearward from the base portion 60a and against which the inner side of the vertical wall portion 56c is abutted. The support member 60 is configured so that, when the dustproof case 56 is attached, the base portion 60a blocks the portion of the opening of the dustproof case 56 formed by the side wall portion 56d that is located outside the intake cover 53.

In the cooling air introduction section 50, the rotating fan 51 is driven by the crankshaft 55, and the air outside the dustproof case 56 is removed from the dustproof case 56 through the ventilation holes 56a and introduced into the dustproof case 56 by the blowing action of the driven rotating fan 51, and is further introduced into the intake cover 53 through the ventilation holes of the intake cover 53 to generate cooling air, which is then introduced into the engine 4 by the rotating fan 51 through the flywheel 54.

[Configuration of the travel transmission device]
As shown in Figures 5 and 6, the traveling transmission device 6 includes a transmission 20 provided in front of the engine 4, and a transmission case 21 provided between the engine 4 and the transmission 20. As shown in Figure 6, the pair of driving wheels 13 of the left and right crawler traveling devices 1 are drivably supported by the transmission 20. As shown in Figures 10 and 12, the transmission case 21 houses a gear interlocking mechanism 22 that interlocks and connects an output shaft 4d of the engine 4 and an input shaft 20a of the transmission 20. The output shaft 4d protrudes forward from the front of the engine 4. The input shaft 20a protrudes rearward from the rear of the transmission 20.

In the traveling transmission device 6, power from the output shaft 4d of the engine 4 is transmitted to the input shaft 20a by the gear interlocking mechanism 22 and input to the transmission 20, and is then transmitted to the left and right driving wheels 13 by the transmission 20.

Specifically, as shown in Figs. 10 and 12, the gear interlocking mechanism 22 includes an output shaft side gear 23 that is interlocked with the output shaft 4d and rotates together with the output shaft 4d, and an input shaft side gear 24 that is interlocked with the input shaft 20a and rotates together with the input shaft 20a. The output shaft side gear 23 is interlocked with the output shaft 4d by interlocking the support shaft 23a of the output shaft side gear 23 with the output shaft 4d. The input shaft side gear 24 is interlocked with the input shaft 20a by interlocking the support shaft 24a of the input shaft side gear 24 with the input shaft 20a via the intermediate shaft 25. The output shaft side gear 23 and the input shaft side gear 24 are meshed, and the gear interlocking mechanism 22 reverses the power of the output shaft 4d and transmits it to the input shaft 20a.

As shown in Figures 6 and 12, the transmission 20 includes an input distribution section 20X having an input shaft 20a, a left running drive section 20L connected to the left side of the input distribution section 20X and capable of driving the left driving wheel 13, and a right running drive section 20R connected to the right side of the input distribution section 20X and capable of driving the right driving wheel 13.

As shown in FIG. 12, the input distribution unit 20X has an input shaft 20a, and also has a distribution transmission shaft 26 to which the power of the input shaft 20a is transmitted via a gear mechanism 26a, and which distributes and transmits the transmitted power to the left driving unit 20L and the right driving unit 20R.

As shown in FIG. 12, the left driving unit 20L and the right driving unit 20R have a continuously variable transmission unit 27 to which the power of the distribution transmission shaft 26 is input, and a gear transmission mechanism 28 that transmits the power changed in speed by the continuously variable transmission unit 27 to the driving wheels 13. The continuously variable transmission unit 27 is composed of a hydrostatic continuously variable transmission device.

As shown in Figures 5 and 6, the transmission case 21 is connected to the engine 4 by a connecting mechanism 65 and is configured to be supported by the engine 4 via the connecting mechanism 65.

As shown in Figures 5, 6, 9, and 11, the connecting mechanism 65 includes a connecting member 66 interposed between the engine 4 and the transmission case 21, a first connecting bolt 67 as a first fastener for fastening the connecting member 66 to the engine 4, and a second connecting bolt 68 as a second fastener for fastening the transmission case 21 to the connecting member 66.

9, a through hole 69 through which the output shaft 4d is inserted is provided in the center of the connecting member 66. The diameter of the through hole 69 is set to a size that allows a circular projection formed at the front of the engine 4 to fit in the through hole 69. A first bolt hole 67a for attaching the first connecting bolt 67 is provided at the edge of the through hole 69 in the connecting member 66, and a second bolt hole 68a for attaching the second connecting bolt 68 is provided at a portion located on the outer periphery side of the connecting member 66 from the first bolt hole 67a. The first connecting bolt 67 in the connecting member 66 is configured to be attached to the edge of the through hole 69, and the second connecting bolt 68 in the connecting member 66 is configured to be attached to a portion located on the outer periphery side of the connecting member 66 from the first connecting bolt 67. The first connecting bolt 67 and the second connecting bolt 68 are configured to be attached at multiple locations.

As shown in Figures 10, 11, and 12, the transmission case 21 is divided into two separate cases 21A in the direction along the axis of the output shaft 4d. The two separate cases 21A are connected by a third connecting bolt 70, which serves as a third fastener separate from the first connecting bolt 67 and the second connecting bolt 68.

The input shaft 20a and the output shaft 4d are arranged so as to be located at different positions in the vertical direction of the vehicle body and in the lateral direction of the vehicle body. Specifically, the input shaft 20a is arranged at a higher position than the output shaft 4d. In a plan view, the input shaft 20a is arranged so as to be located above the center line CL in the left-right direction of the traveling vehicle body 2. The output shaft 4d is arranged so as to be located laterally of the vehicle body than the input shaft 20a. As shown in Figures 10 and 11, the transmission case 21 has an engine side part 21E formed at the lower part of the transmission case 21 so as to connect the output shaft 4d, and a transmission side part 21M formed at the upper part of the transmission case 21 so as to connect the input shaft 20a. The transmission case 21 and the connecting member 66 are connected by the second connecting bolt 68 only at the engine side part 21E of the engine side part 21E and the transmission side part 21M, as shown in Figure 10.

As shown in Figures 10 and 11, a breather valve 71 is connected to the transmission case 21. As shown in Figure 10, a breather port 72 that connects the breather valve 71 is opened in the flange portion 21f of one of the two separate cases 21A. A wall portion 73 that prevents the flow of lubricating oil toward the breather port 72 protrudes into the inside of the separate case 21A. The wall portion 73 prevents the lubricating oil located inside the transmission case 21 from leaking into the breather valve 71 due to tilting or rocking of the traveling machine body.

The transmission case 21 can be supported on the engine 4 based on the following mounting method.
The transmission case 21 is left in an assembled state with the two split cases 21A connected by the third connecting bolt 70. As shown in Fig. 9, the connecting member 66 is connected to the engine 4 by the first connecting bolt 67. Next, as shown in Fig. 11, the engine side portion 21E of the transmission case 21 is connected to the connecting member 66 by the second connecting bolt 68.

[Configuration of the work transmission device]
As shown in Figure 12, the work transmission device 7 includes a work clutch 74 provided inside the transmission case of the transmission 20, an intermediate transmission device 75 provided forward of the transmission 20, a transmission case 34 whose front part is connected to the side part of the grass cutting device 3, and a transmission tube 33 provided between the rear part of the transmission case 34 and the intermediate transmission device 75.

The working clutch 74 is configured so that the power transmitted from the engine 4 to the input shaft 20a of the transmission 20 is input via a gear interlocking mechanism 76 and a transmission shaft 77. The relay transmission device 75 is configured so that the output of the working clutch 74 is input via a transmission shaft 78, and the input power is transmitted to the transmission shaft 80 by a gear interlocking mechanism 79. The transmission case 34 is configured so that the power of the transmission shaft 80 is input, and the input power is transmitted to the cutting blade 43 by a belt transmission mechanism 81.

[Another embodiment]
(1) In the above embodiment, the transmission 20 is provided in front of the engine 4 . However, the transmission 20 may be provided behind the engine 4 .

(2) In the above embodiment, an example was shown in which the input shaft 20a and the output shaft 4d are positioned at different positions in the vertical direction of the aircraft and in the lateral direction of the aircraft, but the output shaft 4d and the input shaft 20a may be positioned at different positions in the vertical direction of the aircraft and at the same position in the lateral direction of the aircraft, or the output shaft 4d and the input shaft 20a may be positioned at the same position in the vertical direction of the aircraft and at different positions in the lateral direction of the aircraft.

(3) In the above embodiment, an example was shown in which the grass cutting device 3 was provided as the working unit, but various working devices such as a snow removal device may also be provided as the working unit.

The present invention can be applied to a work vehicle equipped with a traveling body supported by a pair of left and right crawler traveling devices, a working unit provided at the front of the traveling body, and an engine provided on the traveling body.

1 Crawler traveling device 2 Traveling machine body 3 Working unit (grass cutting device)
Reference Signs List 4 engine 4d output shaft 13 driving wheel body 20 transmission 20a input shaft 21 transmission case 21A split case 21E engine side portion 21M transmission side portion 22 gear interlocking mechanism 65 connecting mechanism 66 connecting member 67 first fastener (first connecting bolt)
68 Second fastener (second connecting bolt)
69 Through hole 70 Third fastener (third connecting bolt)

Claims (4)

A traveling machine body supported by a pair of left and right crawler traveling devices;
A working unit provided at the front of the traveling body;
An engine provided on the traveling body;
a transmission provided in front of or behind the engine and drivably supporting drive wheels of the pair of left and right crawler traveling devices;
a transmission case that is provided between the engine and the transmission and that accommodates a gear interlocking mechanism that interlocks an output shaft of the engine and an input shaft of the transmission;
a coupling mechanism for supporting the transmission case on the engine,
the connecting mechanism includes a connecting member formed as a separate member from the engine and the transmission case and interposed between the engine and the transmission case, a first fastener that fastens the connecting member to the engine, and a second fastener that fastens the transmission case to the connecting member ,
the connecting member is plate-shaped and has a through hole through which the output shaft is inserted,
The connecting member is configured so that the first fastener is attached to the edge of the through hole, and the second fastener is attached to a portion of the connecting member that is closer to the outer periphery than the first fastener . A traveling machine body supported by a pair of left and right crawler traveling devices;
A working unit provided at the front of the traveling body;
An engine provided on the traveling body;
a transmission provided in front of or behind the engine and drivably supporting drive wheels of the pair of left and right crawler traveling devices;
a transmission case that is provided between the engine and the transmission and that accommodates a gear interlocking mechanism that interlocks an output shaft of the engine and an input shaft of the transmission;
a coupling mechanism for supporting the transmission case on the engine,
the connecting mechanism includes a connecting member formed as a separate member from the engine and the transmission case and interposed between the engine and the transmission case, a first fastener that fastens the connecting member to the engine, and a second fastener that fastens the transmission case to the connecting member,
The input shaft is disposed at a higher position than the output shaft,
the transmission case includes an engine side portion formed on a lower portion of the transmission case to which the output shaft is connected, and a transmission side portion formed on an upper portion of the transmission case to which the input shaft is connected,
A work vehicle in which the transmission case and the connecting member are connected by the second fastener only at the engine side portion of the engine side portion and the transmission side portion. The transmission case is divided into two separate cases in a direction along an axis of the output shaft,
3. The work vehicle according to claim 1, wherein the two separate cases are configured to be connected by a third fastener that is different from the first fastener and the second fastener. 4. The work vehicle according to claim 1, wherein the gear interlocking mechanism is configured to reverse the power of the output shaft and transmit the power to the input shaft.

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