JP2006131229A - Traveling vehicle driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling vehicle driving device with a speed change mechanism thereof separated from a reduction gear. <P>SOLUTION: In the traveling vehicle driving device to transmit the power from an engine to a crawler type traveling device via an HST transmission and a reduction gear, the power from the engine is transmitted for speed change to an HST pump Pa of the HST transmission fixed to a rear part of the engine E, and the hydraulic pressure of the HST pump Pa is transmitted to a HST motor M added to the reduction gear G via working fluid pipes 78, 79. In addition, the power of the HST motor M is transmitted to the reduction gear G. Right and left side clutch gears 65L, 65R, side brakes 66L, 66R, a pivotal brake turning clutch 71 which is a reversing mechanism for pivotal brake turn and a reduction gear train are provided on the reduction gear G, the power is output from the reduction gear G through right and left output shafts 68L, 68R, and final reduction gears FG, FG are added to right and left ends of the output shafts 68L, 68R. The power is transmitted from the final reduction gears FG, FG to driving sprockets 24, 24 of right and left crawlers 29, 29. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a body frame having a front portion as a power unit and a rear portion as a cargo box mounting portion is disposed on a crawler type traveling device, and drives an HST transmission and a cargo box that drive the crawler type traveling device. The present invention relates to a configuration of a hydraulic drive unit that supplies oil to a hydraulic cylinder.

  Conventionally, on a crawler type traveling apparatus, a main body part having a front part as a power part and an operating part and a rear part as a cargo box mounting part is disposed, and the crawler type traveling apparatus is connected to the internal combustion engine via an HST transmission and a reduction gear. A transport vehicle that transmits power to the drive shaft is known. This known example will be described. First, the main body portion disposed on the left and right crawler (crawler type) traveling devices is formed of a main body frame, and the front portion of the main body frame supports the power portion, and at the upper portion thereof, a headlamp is provided at the front end. Etc., a front column is mounted, an engine cover is mounted behind the front column, and a control panel including various control devices is disposed behind the front cover. There is also a seat on the side of the control panel. As described above, an operating unit is formed above the power unit, and a cargo box is mounted behind the driving unit so as to be vertically rotatable.

The HST transmission is one of the components of a hydraulic pump connected to the rear part of the engine, which is an internal combustion engine. The HST motor sends pressure oil generated by the HST pump to the HST motor. The drive shaft is used as the input shaft of the reducer. Further, the hydraulic pump is provided with a working pump for a fixed displacement pump having an engine output shaft as a pump shaft, separately from the HST pump of the HST transmission. Connect hydraulic piping to the working pump, branch in the middle of the hydraulic piping, connect one side to the hydraulic cylinder for lifting the platform and connect the hydraulic piping to the side clutch actuator on the other side of the speed reducer Switching operation of the side clutch arranged in
Japanese Utility Model Publication No. 5-66259 Japanese Utility Model Publication No. 5-54158

  The internal structure of the speed reducer includes a brake clutch mechanism that brakes the left and right axles (output shaft of the speed reducer) for steering (or stopping), a brake mechanism that brakes the HST motor shaft itself, Since a gear mechanism for shifting the gear is arranged and has a plurality of mechanisms, a configuration in which the speed change mechanism is separated from the reduction gear has been desired.

The present invention uses the following means in order to solve the above problems.

  In a transport vehicle that transmits power from the engine E to the crawler type traveling device via the HST transmission and the speed reducer G, the power from the engine is supplied to the HST pump Pa of the HST transmission fixed at the rear of the engine E. The hydraulic pressure of the HST pump Pa is transmitted to the HST motor M attached to the speed reducer G via the hydraulic oil pipes 78 and 79, the output of the HST motor M is transmitted to the speed reducer G, and the speed reduction is performed. Machine G is provided with left and right side clutch gears 65L and 65R, side brakes 66L and 66R, a center turning clutch 71 that is a reverse mechanism for turning the center, and a reduction gear train. Output from the output shafts 68L and 68R, and terminal reduction gears FG and FG are attached to the left and right ends of the output shafts 68L and 68R. Rocket 24, 24 is intended to power transmission.

Since the present invention is configured as described above, the following effects can be obtained.
In a transport vehicle that transmits power from the engine E to the crawler type traveling device via the HST transmission and the speed reducer G, the power from the engine is supplied to the HST pump Pa of the HST transmission fixed at the rear of the engine E. The hydraulic pressure of the HST pump Pa is transmitted to the HST motor M attached to the speed reducer G via the hydraulic oil pipes 78 and 79, the output of the HST motor M is transmitted to the speed reducer G, and the speed reduction is performed. Machine G is provided with left and right side clutch gears 65L and 65R, side brakes 66L and 66R, a center turning clutch 71 that is a reversing mechanism for turning the center, and a reduction gear train. Output from the output shafts 68L and 68R, and terminal reduction gears FG and FG are attached to the left and right ends of the output shafts 68L and 68R, and drive claw of the left and right crawlers 29 and 29 are connected from the terminal reduction gears FG and FG. Since power transmission to the rocket 24, 24, change of the traveling speed of the traveling vehicle can be configured simple transmission mechanism capable of shifting by changing the oil feeding quantity of the pressure oil by the HST transmission steplessly.
In addition, the speed reducer is separated from the speed change mechanism, and the speed reducer is provided with a side clutch, a side clutch brake, and a reverse rotation mechanism. The operation links on the speed reducer can be reduced, the operation links of the side clutch gear can be arranged with a margin, and the side clutch can be operated stably.

Embodiments of the present invention will be described with reference to the accompanying drawings.
1 is a left side view of a transport vehicle according to the present invention, FIG. 2 is a partial right side view, FIG. 3 is a plan view, FIG. 4 is a front view, and FIG. 5 is a main body frame 1 and a front frame 2. It is a top view which shows the frame structure of a transport vehicle.

  6 is a side view showing the power unit arrangement structure of the transport vehicle, FIG. 7 is also a plan view, FIG. 8 is also a front view, FIG. 9 is an internal plan view of the reducer G, FIG. 10 is a hydraulic system diagram of the transport vehicle, FIG. 11 is a side view showing a link mechanism of levers arranged in the driving part, and FIG. 12 is a left side view showing the arrangement structure of the operation pedal in the driving part of the transport vehicle.

First, a schematic configuration of a transport vehicle to which the present invention is applied will be described with reference to FIGS.
A crawler traveling device is supported on the left and right of the main body frame 1, and a front frame 2 is attached to the front end of the main body frame 1, and a front column 5 is erected on the front frame 2, and thereafter On the other hand, an engine cover 6 is mounted on the main body frame 1, and a control panel 7 is formed on the upper right portion thereof.

  On the right side of the engine cover 6, a driver's seat 12 that can be reversed is mounted. As described above, the cargo box 22 is mounted on the main body frame 1 so as to be movable up and down behind the driving unit on which the engine cover 6 and the driver's seat 12 are mounted.

  As shown in FIG. 5, the main body frame 1 has a front plate frame 1a in the left-right direction at the front end, and a left-side plate frame 1b and a right-side plate frame 1c parallel in the front-rear direction are arranged from the front plate frame 1a. In addition, side frames 1d and 1e are arranged on the outer sides of both side plate frames 1b and 1c. A portion surrounded by the front plate frame 1a and the side frames 1d and 1e is used as a power unit, and related parts of the power engine are disposed. Also, crawler frames 1f and 1f are extended behind both side frames 1d and 1e, a connecting frame 1g in the left-right direction is provided between the middle portions of both crawler frames 1f and 1f, and a rear end frame 1h is provided between the rear ends. Is installed side by side.

  Further, the side plate frames 1b and 1c extend rearward from the rear ends of the side frames 1c and 1d, and the rear ends thereof are connected to the packing box receiving columns 1j and 1j provided upright on the connection frame 1g. On the rear end frame 1h, a cylinder bracket 1k for pivotally supporting the load box elevating cylinder 23 and a load box bracket 1m and 1m for pivotally supporting the load box 22 are erected.

  The upper part from the connecting frame 1g to the rear end frame 1h is a packing box mounting portion. That is, the rear end of the packing box 22 is pivotally supported on the packing box brackets 1m and 1m, and the base end of the packing box elevating cylinder 23 is pivotally supported on the cylinder bracket 1k. , Pivotally connected to the substantially central portion of the bottom of the packing box 22. The packing box 22 is in a state where the front end portion is placed on the packing box receiving column 1j and 1j in the normal lowered position, and when the packing box lifting / lowering cylinder 23 is driven to extend, the packing box 22 rotates upward. is there.

  A front frame 2 is fixed to the front end of the main body frame 1. A headlamp is disposed in the front frame 2. Further, a bumper 4 is attached to the front portion of the front frame 2 and a front column 5 is mounted on the upper portion thereof.

Based on such a frame configuration, the power unit structure of the transport vehicle will be described with reference to FIGS.
Between the side plate frames 1b and 1c in the power section A, hydraulic system members such as an engine E, a reduction gear G, and an HST transmission are arranged. That is, an engine support frame 1i is formed inside the right side plate frame 1c, and the engine support frame 1i is located on the right side in the power section A, and further, a distance from the front plate frame 1a. It is located on the back side.

  The engine support frame 1i (near the right side plate frame 1c) surrounds an oil pan Ea suspended from the lower end of the engine E, and supports the engine E from below. The rear end of the engine E is on the output side, and a hydraulic pump P is continuously provided via a flywheel housing Eb. The hydraulic pump P extends rearward from the rear end of the power unit and is disposed in the cargo box mounting unit. A cargo box 22 is mounted above this. Further, a radiator R is disposed at the front of the engine E, a certain space is opened behind the front plate frame 1a, and an HST motor M is disposed in this space.

  Further, on the left side of the engine E, a portion near the left side plate frame 1b is provided with a reduction gear G that is long in the front-rear direction and substantially horizontal. An HST motor M is attached to the front end of the reduction gear G in the left-right direction. These HST motor M, reduction gear G, and hydraulic pump P surround the engine E in a U shape in plan view, and the upper end of the HST motor M, the speed reducer G, and the hydraulic pump P are arranged to be substantially flat in side view, and protrude upward from the upper end of the main body frame 1. It arrange | positions so that it may not happen, and arrange | positions as low as possible, and has a favorable side view.

  The hydraulic piping connecting the HST motor M and the HST pump Pa is disposed in the space between the speed reducer G and the front-rear chassis, that is, the left side plate frame 1b, as shown in a plan view in FIG. Since the piping is provided between the two, the hydraulic piping can be protected. Further, since the HST motor M and the HST pump Pa are arranged on substantially the same horizontal plane, the height of the pressure oil to be fed is substantially the same, and the piping configuration is configured to reduce hydraulic loss. In addition, since the HST motor M is disposed in front of the radiator R, the hydraulic oil including the hydraulic pipe piped to the HST motor M is confronted with the radiator R, so that the hydraulic oil is cooled and the cooling effect is enhanced. it can.

  The upper part of the power part A is a driving part, and the engine E and the driver's seat 12 are arranged side by side. The engine cover 6 and the control panel 7 are arranged on the left and right as shown in FIG. 3 to widen the arrangement space of the operating part at the upper part of the left and right side plate frames 1b and 1c. Further, the HST motor M described above is arranged in a space provided between the front column 5 mounted on the front frame 2 and the engine E, and between the front column 5 and the engine cover 6 above the space. The passage plate 8 is arranged in accordance with the height of the step 9 and the HST motor M is mounted thereon, and the upper left and right sides are open floors.

  The passage plate 8 is pivotally supported at the front portion or the rear portion, and the passage plate 8 is configured to be pivotable upward so that the floor surface is opened upward, thereby maintaining the HST motor M. Making it easy. Further, a step plate 9 is attached to the left side of the control panel 7, and the step plate 9 extends horizontally behind the front column 5 on the left side of the control panel 7 and is juxtaposed with the engine E. The upper part of the reduction gear G is covered.

  Furthermore, a driver's seat 12 is arranged on the step plate 9. The driver's seat 12 protrudes from the driver's seat lower base 10 from above the step plate 9, the driver's seat upper base 11 is rotatably attached to the driver's seat lower base 10, and the lower surface of the driver's seat 12 is fixed to the upper portion of the driver's seat upper base 11. The driver's seat 12 can be reversed back and forth. A driver seat lower base 10 and a driver seat upper base 11 which are pivotal support points of the driver seat 12 are arranged in the front and rear central portions of the step plate 9, and when the driver seat 12 is reversed, it is involved in forward operation and backward operation. An operation space on the same flat surface is provided. The rotation fulcrum is located substantially above the output shaft 68R of the speed reducer G, which will be described later, and is housed within the longitudinal length of the crawler traveling device, so that the user gets on the driver's seat 12 when performing a turning operation. The operator is not swung in the direction opposite to the turning direction.

Next, the internal structure of the reduction gear G will be described with reference to FIG.
The HST motor M is supplied with pressure oil from the HST pump Pa, and its motor shaft is used as an input shaft 60 in the speed reducer G. A service brake 61 is provided around the left end of the input shaft 60. A service brake arm 62 of the service brake 61 protrudes on the left side of the reduction gear G, and the service brake arm 62 is rotated by an operation of a brake pedal 21 or a parking brake lever 19 described later in the driving unit, The service brake 61 is pressed to brake the input shaft 60, and the drive sprockets 24, 24 of both the left and right crawler travel devices are braked via the output shafts 68L, 68R protruding from the left and right side surfaces of the speed reducer G. is there.

  Behind the input shaft 60, a counter shaft 63, a side clutch shaft 64, output shafts 68L and 68R, a counter shaft 69, and an interlining pivot clutch shaft 70 are supported in parallel. A gear 60 a is engraved on the input shaft 60 and meshes with a gear 63 a fixed on the counter shaft 63, and the gear 63 b fixed on the counter shaft 63 is fixed on the side clutch shaft 64. The transmission gear 64a meshes with the transmission gear 64a, and tooth portions are provided on both sides of the transmission gear 64a, and are provided on the inner surfaces of the side clutch gears 65L and 65R slidably fitted on the side clutch shaft 64. It can mesh with the teeth.

  The side clutch gears 65L and 65R are configured to slide by the rotation of the side clutch arms 67L and 67R pivotally supported on the upper part of the speed reducer G, and are engaged with the transmission gear 64a by this sliding. break away. Further, side brakes 66L and 66R are provided outside the left and right side clutch gears 65L and 65R, respectively, and the side clutch gear 65 (65L and 65R) separates from the transmission gear 64a and slides outward by a certain amount or more. When moved, the friction plates of the side brakes 66 (66L and 66R) are pressed against each other to be braked.

  The left and right output shafts 68L and 68R are supported behind the side clutch shaft 64, and the output gears 68La and 68Ra attached to the output shafts 68 mesh with the side clutch gears 65L and 65R, respectively. The output shafts 68L and 68R protrude in the left-right direction from the left and right of the speed reducer G. Since the speed reducer G is located on the left side of the machine body, a joint 68Rb is connected to the right output shaft 68R. It is extended. The right output shaft 68R and the joint 68Rb pass in front of the oil pan Ea below the engine E.

  On the other hand, terminal reduction gears FG and FG are fixed to the front ends of the crawler frames 1f and 1f below the side frames 1d and 1e, and the drive sprocket 24 is pivoted outward from each terminal reduction gear FG. I support. At the rear upper position of each drive sprocket 24, the outer ends of the output shaft 68L and the joint 68Rb are connected to the input shaft FGa of each terminal reduction gear FG, and the rotation of the output shaft 68 (68L / 68R) It is transmitted to the drive sprocket 24 through a gear mechanism in the terminal reduction gear FG.

  A joint member 68a is interposed in a connecting portion between the right output shaft 68R and the joint 68Rb, and a connecting portion between the left output shaft 68L and the joint 68Rb to each input shaft FGa of the left and right terminal reduction gears FG. ing. The input shaft 60, the output shaft 68, and the sprocket shaft 3, which are drive shafts that connect the devices to transmit power, are arranged in a substantially inverted triangular shape in a side view as shown in FIG. Transmission parts are arranged on both the front and rear sides of the sprocket shaft 3 to improve the front and rear weight balance. The input shaft 60, the output shaft 68, and the sprocket shaft 3 are disposed at a position between the crawler traveling devices, and are disposed below the upper end of the crawler traveling device, so that the center of gravity is lowered to maintain stability. .

  Further, in the reduction gear G, a gear mechanism for interlining turning (spin turn) is provided behind the shaft support portions of the output shafts 68L and 68R. That is, the interlining swivel clutch shaft 70 is pivotally supported at the rear end, and two series of reverse rotation gears 70a and 70b are provided around this. The reverse rotation gear 70 a is fixed to the interlining turning clutch shaft 70. On the other hand, the reverse rotation gear 70 b can be engaged with and disengaged from the interlining turning clutch shaft 70 via the interlining turning clutch 71. A counter gear 69a provided with a counter shaft 69 is interposed and engaged between the reverse gear 70a and the output gear 68Ra of the right output shaft 68R.

  On the other hand, the reverse rotation gear 70b is directly meshed with the output gear 68La on the left output shaft 68L. Normally, the interlining swivel clutch 71 is disengaged, and transmission from the right output shaft 68R to the interlining revolving clutch shaft 70 via the gears 68Ra, 69a, and 70a, and reverse rotation from the output gear 68La of the left output shaft 68L. The transmission to the gear 70b is independent.

  For example, when the interlining pivot clutch 71 is engaged with the left side clutch gear 65L disengaged to turn the interlining to the right side, the right transmission shaft is meshed with the engaged right side clutch gear 65R. 68R is transmitted to the left output shaft 68L that meshes with the left side clutch gear 65L in the disengaged state via the interlining turning gear mechanism, so that the left output shaft 68L is opposite to the rotation direction of the right output shaft 68R. It is rotated.

  As described above, the speed reducer G is configured to include a turning mechanism using a side clutch, a side brake, and the like, and a gear mechanism for turning the interlining, and the turning mechanism at a position forward of the output shaft 68. Is arranged, and a gear mechanism for turning the interlining is arranged at the rear position of the output shaft 68, so that the speed reducer G has an excellent weight balance in the horizontal front-rear direction. The speed reducer G is configured to perform a steering mechanism for switching the rotation direction between the engagement and disengagement of rotation of the left and right output shafts 68L and 68R, and the rotation speeds of the output shafts 68L and 68R are the HST pump Pa and the HST motor. A simple speed change mechanism that changes continuously by adjusting the amount of pressure oil supplied by H is configured. Further, the speed change mechanism is separated from the speed reducer G, the operation links on the speed reducer G are reduced, and the operation links of the side clutch gear 65 are arranged with a margin.

  As shown in FIG. 6, a steering valve bracket 72 is fixed to the front plate frame 1 a of the main body frame 1 and a steering valve case 73 is mounted above the speed reducer G. The steering valve case 73 has two hydraulically driven side clutch actuators 74L and 74R protruding rearward and pivotally connected to the side clutch arms 67L and 67R. The side clutch arm 67 (67L / 67R) is rotated by the extension / contraction drive of the side clutch actuator 74 (74L / 74R). For example, when making a left turn from straight ahead, the left side clutch actuator 74L is actuated to rotate the left side clutch arm 67L to the braking side, disengage the left side clutch gear 65L, and further brake the left side brake 66L. It is in a state.

  The steering valve case 73 is provided with a variable relief valve 75 for controlling the relief pressure from the side clutch actuator 74, and an electromagnetic pilot hydraulic pressure for controlling the supply of pressure oil to the side clutch actuator 74. A steering valve 76 as a valve is additionally provided. The steering valve 76 is controlled to switch to three positions of neutral, left turn, and right turn by the operation of the steering lever 15 described later. For example, when turning left, the steering valve 76 is set to the left turn position and operates the left side clutch actuator 74L. Will be allowed to. The variable relief valve 75 changes in valve opening degree (that is, the relief pressure) in proportion to the tilt angle of the steering lever 15 described later, and the expansion / contraction amount of the side clutch actuator 74 that is operated by the set of the steering valve 76 is adjusted. The function of making it proportional to the tilt angle of the steering lever 15 is provided.

  Further, an interlining swivel valve 77 that is an electromagnetic pilot hydraulic valve is provided in the steering valve case 73. The interlining swivel valve 77 is set to interpolate based on the switch mechanism (see FIGS. 20 to 23) described later, and when the pilot voltage is turned on (the interlining swivel valve solenoid 77a is operated), the hydraulic core described later is used. The ground turning clutch 71 is engaged (when the pilot voltage of the interlining turning valve 77 is OFF, it is in the disengaged state), and the left and right output shafts 68L and 68R are rotated reversely to each other.

Here, the hydraulic system will be described with reference to FIG.
From the HST pump Pa of the hydraulic pump P, hydraulic oil pipes 78 and 79 are connected to the HST motor M to form a closed circuit. The HST pump Pa has a movable swash plate, and a swash plate control valve 80, which is an electromagnetic pilot valve, is switched in three stages by a forward / reverse switching lever 15 to be described later. Based on this, a hydraulic swash plate control actuator 81 is provided. Can be switched to three positions, and the movable swash plate can be switched to three positions: neutral position, forward position, and reverse position. The HST motor M is a variable capacity motor and can change the motor shaft. Also, when the HST pump Pa is set to neutral (with the swash plate control actuator 40 set to the neutral position) and the hydraulic oil flow through the hydraulic oil pipes 78 and 79 is stopped, a hydraulic mechanism is provided so that the motor shaft is automatically braked. Yes.

  By the way, the pressure oil supplied from the swash plate control valve 80 to the swash plate control actuator 81 is supplied to the hydraulic pump P from the fixed capacity boost pump Pc having the output shaft of the engine E as the pump shaft (through the line filter LF). ) Extraction is performed via an inching valve 82 from an oil passage R3 that supplements hydraulic fluid to the communication oil passages R1 and R2 to the hydraulic oil pipes 78 and 79 in the HST pump Pa. By passing through the inching valve 82, the flow rate is adjusted and the pressure oil is supplied to the swash plate control actuator 81 at a constant flow rate regardless of the fluctuation of the engine speed. The forward / reverse switching by the operation of the forward / reverse switching lever 15 and the reaction speed of stopping are constant.

  The inching valve 82 closes the oil path from the oil path R3 to the swash plate control valve 39 when the service brake 61 is pressed (braking the input shaft 60) by depressing the brake pedal 21, which will be described later. It will be in the state which returns oil. As a result, the pressure oil supply to the swash plate control actuator 81 is stopped regardless of the position where the swash plate control valve 39 is set, and the swash plate control actuator 81 is neutralized by the force of the return spring. Return. As a result, the HST pump Pa becomes neutral, the working oil circulation of the working oil pipes 78 and 79 is stopped, and the motor shaft drive of the HST motor M is also stopped. In this way, the service brake 61 enters the braking state with the motor shaft and the input shaft 60 connected to the motor shaft stopped.

  As a hydraulic drive device other than the HST motor M, the transport vehicle of the present embodiment includes an actuator 74 that operates the side clutch and the side clutch brake, and a cargo box elevating cylinder 23 as a working machine. As described above, the steering valve 76 is provided in the steering valve case 73, and the cargo box elevating control valve 84 is provided for the cargo box elevating cylinder 23. The hydraulic pump P is also provided with a working pump Pb of a fixed displacement pump having the engine output shaft as a pump shaft, and a discharge oil passage from the working pump Pb is connected to the steering valve 76 via the flow divider 83. And an oil path to the cargo box elevating control valve 84. In the flow divider 83, a throttle valve for adjusting the flow rate is provided in each branch oil passage, and pressure oil is supplied at a constant flow rate to any branch oil passage. Since it is important for the pressure oil to keep the steering property constant, in order to make the flow rate constant, a relief valve 83a is connected to the branch oil passage to the steering valve 76, and an excess to the steering valve 76 is obtained. The oil is supplied to the cargo box elevating control valve 84.

Next, each operation lever arranged in the operation unit will be described with reference to FIG.
The control panel 7 is provided with a steering lever 15 for operating a side clutch, a forward / reverse switching lever 17 and a cargo box elevating lever 18, and a parking brake lever 19 is provided on the upper seat 11. ing. In FIG. 11, the steering lever 15 is disposed on the vertical center line SL of the seat base 10 in the left side view so that the driver's seat 12 can be operated at the same operation interval regardless of whether the driver's seat 12 is directed forward or backward. The steering switches 44 and 44 at the base end of the steering lever 15 are electromagnetic solenoid switches of a hydraulic valve for controlling the side clutch actuator 43 that is turned ON / OFF by tilting the steering lever 15 left and right. When the direction lever 15 is ON at the stroke end and when the interlining turning setting switch 16 is also ON, the interlining turning clutch 40 is engaged and the interlining turns. Further, the forward / reverse selector switches 46F and 46R at the base end of the forward / reverse selector lever 17 are switches for switching the inclination of the movable swash plate of the HST pump Pa.

  Before and after the step plate 9, as shown in FIG. 12, in front of the seat 12, the shift operation and the brake operation can be performed with the feet in both the forward-facing state and the backward-facing state of the seat 12. Are provided with a front accelerator pedal 20F and a front brake pedal 21F, and a rear accelerator pedal 20R and a rear brake pedal 21R on the rear side. The accelerator pedal 20 (20F / 20R) controls the engine speed in proportion to the stroke, and the drive sprocket 24 is transmitted from the engine output shaft via the HST mechanism and the reduction gear G (and the final reduction gear FG). Control the number of revolutions.

  Further, as described above, the brake pedal 21 (21R / 21R) operates the service brake 61 to brake the input shaft 60 of the speed reducer G, and switches the inching valve 82 to neutralize the HST pump Pa. The rotation of the motor shaft of the motor M is stopped. Further, a parking brake lever 19 for operating the service brake arm 31a is disposed on the driver's seat upper base 11.

  Finally, the crawler traveling device will be described with reference to FIGS. As described above, the left and right crawler travel devices are each provided with the terminal reduction gear FG at the front end of the crawler frame 1f and pivotally supporting the drive sprocket 24. The idler 28 is movably supported. Under the crawler frame 1f, six front and rear wheels 25 are supported, but are supported by equalizers 26F and 26R except for the front and last wheels 25. A tension roller 27 is pivotally supported on the upper portion of the crawler frame 1f, and a crawler 29 is wound around these to form a crawler traveling device.

It is a left view of the transport vehicle which concerns on this invention. It is a partial right view similarly. It is also a plan view. It is also a front view. 2 is a plan view showing a frame structure of a transport vehicle including a main body frame 1 and a front frame 2. FIG. It is a side view which shows the motive power part arrangement | positioning structure of a transport vehicle. It is also a plan view. It is also a front view. 3 is an internal plan view of a reduction gear G. FIG. It is a hydraulic system diagram of a transport vehicle. It is a side view which shows the link mechanism of the levers arrange | positioned at a driving | running part. It is a left view which shows the arrangement structure of the operation pedal in the driving | running | working part of a transport vehicle.

Explanation of symbols

A Power unit E Engine Pa HST pump M HST motor G Reducer 1 Body frame 23 Cargo box lifting cylinder 65 Side clutch gear 74 Side clutch actuator 83 Flow divider

Claims (1)

  In a transport vehicle that transmits power from the engine E to the crawler type traveling device via the HST transmission and the speed reducer G, the power from the engine is supplied to the HST pump Pa of the HST transmission fixed at the rear of the engine E. Then, the hydraulic pressure of the HST pump Pa is transmitted to the HST motor M attached to the speed reducer G via the hydraulic oil pipes 78 and 79, and the output of the HST motor M is transmitted to the speed reducer G, and the speed reduction is performed. Machine G is provided with left and right side clutch gears 65L and 65R, side brakes 66L and 66R, a center turning clutch 71 that is a reverse mechanism for turning the center, and a reduction gear train. Output from the output shafts 68L and 68R, and terminal reduction gears FG and FG are attached to the left and right ends of the output shafts 68L and 68R. Drive of the traveling vehicle, characterized in that the power transmission to the rocket 24, 24.

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