JP2010089677A - Four crawler type vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work vehicle having high traveling performance in a place having a soft ground such as an ill-drained paddy field. <P>SOLUTION: The four crawler type vehicle 1 is supported by pairs 10, 11 of right and left crawler traveling devices respectively arranged before/behind a traveling machine body 2. The front crawler traveling devices 10 arranged on the machine body front side are configured by bending a front side of a truck frame 21, and disposes a front idler wheel 23 at height not less than a half of the whole height of the front crawler traveling device 10 (H<SB>2</SB>≥H<SB>1</SB>/2). The rear crawler traveling devices 11 dispose a front idler wheel 26 at the generally same height as the front idler wheel 23 of the front crawler traveling devices 10 (H<SB>2</SB>≈H<SB>4</SB>), and makes a distance between the front idler wheel 26 and a rolling wheel 30a longer than the front crawler traveling device 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a four-crawler type vehicle, for example, a four-crawler type tractor provided with a pair of left and right crawler traveling devices on the front and rear of the machine body, and more particularly to a configuration of the crawler traveling device.

  Conventionally, a track frame (frame) capable of rotating relative to the airframe is provided, and idler wheels (first and second wheels) are provided at the front and rear ends of the track frame via two link mechanisms, respectively. A triangular crawler traveling device that is disposed and has a distance from the front idler wheel (first wheel) to the axle center that is longer than the distance from the rear idler wheel (second wheel) to the axle center. A 4-crawler type vehicle has been devised that includes a pair of left and right front and rear sides of the airframe (see Patent Document 1).

Japanese Patent Laid-Open No. 9-109947

  When the crawler traveling device is configured to be asymmetrical like the four-crawler type vehicle described in Patent Document 1, the load applied to the rear side of the crawler traveling device is larger than the load applied to the front side, and there are obstacles and irregularities. Although it can travel easily in the field, in the case of a wetland that travels while being buried to a certain depth, if there is no elevation angle at the front of the crawler traveling device, it will push mud and it will act as a resistance and go straight It was difficult to drive with a large loss of horsepower as well as poor performance. In particular, when running on a super wet field where the ground is soft, the front end of the crawler running device is often insufficient and stats.

  Accordingly, the present invention provides the front idler wheel of the front crawler device at a height that is at least half of the total height of the front crawler travel device, and the front idler wheel of the rear crawler travel device at the front. It is an object of the present invention to provide a 4-crawler type vehicle that solves the above-mentioned problems by being disposed at substantially the same height as the front idler wheel of the crawler traveling device.

According to the first aspect of the present invention, a drive sprocket (19, 20) mounted on an axle (16, 17) and a front idler wheel (23 disposed at the front end of a track frame (21, 22) provided below the sprocket (23). 26), the rear idler wheel (25, 27) disposed at the rear end of the track frame (21, 22), and the front and rear idler wheels (23, 25, 26, 27), A crawler traveling device (10, 11) in which a crawler (31, 32) is wound around a rolling wheel (29, 30) rotatably attached to the track frame (21, 22) is respectively provided in front of and behind the airframe. In the 4-crawler type vehicle (1) provided with a pair of left and right,
The front idler wheel (23) of the front crawler traveling device (10) provided in front of the airframe (2) is disposed at a half or more of the total height of the front crawler traveling device (10) ( H ₂ ≧ H _1/2 ), increasing the elevation angle (α) formed by the front idler wheel (23) and the lower rolling wheel (29a),
The front idler wheel (26) is disposed at substantially the same height as the front idler wheel (23) of the front crawler traveling device (10) (H ₂ ≈H ₄ ), and the rear crawler traveling device (11). With
The four-crawler type vehicle (1) is characterized by the above.

The invention according to claim 2 is that the rear crawler traveling device (11) is configured such that a front-rear direction distance (b) between the front idler wheel (26) and the wheel (30a) is the front crawler traveling device. Compared with (10), it is formed longer forward (b> a), and its elevation angle (γ) is smaller than the elevation angle (α) of the front crawler travel device (10) (γ < α),
The four-crawler type vehicle according to claim 1.

  In addition, although the code | symbol etc. in a parenthesis is for contrast with drawing, it does not have any influence on a claim by this.

  According to the first aspect of the present invention, the front idler wheel of the front crawler traveling device is disposed at a height position that is at least half of the total height, and the front idler wheel of the rear crawler traveling device is disposed in front. In combination with the front idler wheel of the front crawler traveling device, the mud at the front end of the crawler traveling device, even if it is a super wet field with a large amount of subsidence, Since the running resistance is greatly reduced without pressing, the running performance in the wetland is improved and the vehicle can run smoothly. Furthermore, the mud pushed away by the front idler wheel does not collect at the front of the rear crawler travel device.

  According to the invention according to claim 2, when the elevation angle of the rear crawler traveling device is made smaller than the elevation angle of the front crawler traveling device, when the crawler traveling device travels in a wetland or the like buried to a certain depth, The lower part (upward rising part) becomes an effective ground plane, and the ground pressure can be lowered.

  Embodiments according to the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, a tractor 1 as a working vehicle according to the present invention has an engine 41 (see FIG. 5) covered with a bonnet 3 in front of a traveling machine body 2 and behind the engine 41. The cabin 5 is provided with a driving operation unit 7 and a driving seat 9 including a steering handle 6 and the like.

  The traveling machine body 2 is supported by front crawler traveling apparatuses 10 and 10 and rear crawler traveling apparatuses 11 and 11, and the tractor 1 is provided with a pair of left and right crawler traveling apparatuses 10, front and rear. This is a 4-crawler type tractor driven by 10, 11, 11.

[Outline of crawler travel device]
These crawler traveling devices 10, 10, 11, and 11 are supported by final cases 15 connected to the left and right sides of a transmission case 13 as a front axle housing and a rear axle housing (see FIG. 3). Drive sprockets 19 and 20 attached to the axles 16 and 17 at the front ends, front and rear idler wheels 23, 25, 26, and 27 provided at front and rear ends of the track frames 21 and 22, and front and rear idler wheels 23 and 25, respectively. , 26 and 27, crawlers 31 and 32 are wound around a plurality of rollers 29... 30 which are rotatably mounted below the track frames 21 and 22.

  The track frames 21 and 22 are fitted to the outer periphery of the final cases 15 and 15 on the front end side, and attached to a holder 33 that swings back and forth about the axles 16 and 17 via connecting brackets 35 and 36. Thus, the crawler traveling devices 10, 10, 11, and 11 are configured to be swingable back and forth within a predetermined range about the axles 16 and 17 (see the two-dot chain line portions in FIGS. 1 and 2). .

  Further, below the track frames 21 and 22, crawler guides 38 and 37 for preventing the crawlers 31 and 32 from being detached from the rollers 29 and 30 are provided. The idler wheels 23, 25, 26, and 27 are oriented in the axial direction.

[Description of front crawler travel device]
Next, the front crawler traveling device 10 will be described in detail. As shown in FIG. 1, the track frame 21 of the front crawler traveling device 10 is formed to bend toward the upper side of the machine body in the vicinity of the upper side of the wheel 29a disposed at the front end of the machine body. A front idler wheel 23 is rotatably attached to the front end of the frame 21.

Since the front idler wheel 23 is attached to the tip of the track frame 21 bent upward, the front idler wheel 23 is positioned at a height H ₂ that is more than one half of the total height H ₁ of the front crawler traveling device 10. and _{(H 2 ≧ H 1/2} ), the elevation of the crawler front formed by the rolling wheel 29a disposed on the front idler wheel 23 and the vehicle body front α becomes large.

On the other hand, the rear idler wheel 25 is attached to the rear end portion of the track frame 21 extending in parallel in the longitudinal direction of the machine body, and its height H ₃ is less than half of the total height H ₁ of the front crawler traveling device 10. becomes _{(H 1/2> H 3} ) are arranged as a rear upper inclined surface B of the crawler 31 which is formed by the rear idler wheel 25, the angle β between the field plane, the elevation angle The angle is almost the same as α. Therefore, the inclined surface (rising portion) A below the front portion of the crawler 31 and the inclined surface B above the rear portion are in a substantially parallel relationship, and the front crawler traveling device 10 has a generally rhombus (substantially parallel sides) as a whole. Shape).

  Next, the support structure of the front crawler traveling device 10 will be described in detail. The front crawler traveling device 10 is supported by the final case 15 as described above, and the final case 15 is connected to the front axle housing 13 via a kingpin case 39 as shown in FIGS. ing.

  The track frame 21 is connected to a holder 33 fitted to the tip of the final case 15 via a connection bracket 35. An attachment portion between the connection bracket 35 and the track frame 21 is made of rubber or the like. A vibration isolator 40 made of an elastic member is interposed.

  The front crawler traveling device 10 has a large ground contact area due to the fact that the front crawler traveling device 10 is steered to the left and right and the elevation angle α is large so as not to be stacked in the wet field, and therefore travels on a paved road surface or the like. In this case, a plurality of crawler lugs are grounded at the same time, or only one crawler lug is grounded, and a vertical movement phenomenon occurs, resulting in running vibration. The vibration isolator 40 includes a damper that cushions the running vibration. It has become.

  In addition, the vibration isolator 40 may be disposed at an attachment portion between the holder 33 and the connecting bracket 35 in order to buffer the traveling vibration, or a suspension may be provided on the front axle from the viewpoint of buffering the traveling vibration. good.

[Description of rear crawler travel device]
Next, the rear crawler traveling device 11 will be described in detail. Similarly to the front crawler traveling device 10, the rear crawler traveling device 11 is configured by winding a crawler 32 around the drive sprocket 20, the front idler wheel 26, the rear idler wheel 27, and the rollers 30. The front idler wheel 26 is disposed above the rollers 30 to form an elevation angle γ at the front part of the crawler.

As shown in FIGS. 1 and 2, the front idler wheel 26 of the rear crawler traveling device 11 is disposed at substantially the same height as the front idler wheel 23 of the front crawler traveling device 10 (H ₄ ≒ _H 2), is located in one or more of the height of half the total height _{H 1} of the front crawler traveling units _{10 (H 4 ≧ H 1/} 2).

  Further, the rear crawler traveling device 11 has an axle center (rear axle 17) located on the rear side of a half of its front and rear length, and the front idler wheel 26 and the front end side of the plurality of wheels 30. The front-rear direction distance b between the wheel 30a and the wheel 30a is longer than the front crawler traveling device 10 (b> a). Therefore, the elevation angle γ of the rear crawler traveling device 11 is smaller than the elevation angle α of the front crawler traveling device 10 (γ> α), and the front lower inclined surface (rising up) of the crawler 32 that rises upward from the ground. Part) C is formed longer than the inclined surface A at the front lower side of the front crawler traveling device 10.

On the other hand, the rear idler wheel 27 is mounted to the rear end portion of the track frame 22 extending parallel to the body longitudinal direction, a height H ₅ is disposed below the front idler wheel 26 (H _4> H _5).

[Description of power transmission mechanism of tractor]
Next, the power transmission mechanism of the tractor will be described. As shown in FIG. 5, the power output from the engine 41 is input to the transmission 42. The power input to the transmission 42 is output to the main shaft 45 via the main clutch 43 and is shifted by the main transmission 46 and the sub-transmission 47 including a plurality of transmission gears and clutches.

  The power shifted by the main transmission 46 and the sub-transmission 47 is divided into two crawler drives that output power to the rear crawler travel device 11 and four crawler drives that output power to the front and rear crawler travel devices 10 and 11. The power output to the 2-crawler-4 crawler drive switching unit 49 to be switched and branched to the rear crawler travel device 11 side in the 2-crawler-4 crawler drive switch unit 49 is transmitted to the rear crawler travel device via the differential device 50. 11 is output.

  On the other hand, the power branched to the front crawler travel device 10 side in the 2 crawler-4 crawler drive switching unit 49 is equal to the standard state where the drive speeds of the front crawler travel device 10 and the rear crawler travel device 11 are substantially the same. Then, the front crawler traveling device 10 is output to an acceleration switching mechanism (transmission mechanism) 51 that switches between an increasing state (acceleration state) for driving the front crawler traveling device 10 faster than the rear crawler traveling device 11. The power shifted to the standard state or the increased speed state by the speed increasing / changing speed changing mechanism (transmission mechanism) 51 is output to the front crawler traveling device 10 via the differential device 52.

  The power output to the main shaft 45 is also output to the PTO shaft 56 via the PTO transmission unit 53, and the power is transmitted to various working machines.

  As shown in FIG. 6, the speed increasing / changing speed change mechanism 51 uses the switching clutch mechanism 60 to transfer the power from either the standard gear 57 or the speed increasing gear 59 having a different number of teeth to the front crawler traveling device 10. The standard state and the speed-up state are switched by outputting to the 4-crawler drive shaft 61 that transmits power, and the speed-up gear 59 is formed with a gear having fewer teeth than the standard gear 57.

  The switching clutch mechanism 60 includes a ball clutch 62 for connecting / disconnecting power from the standard gear 57 and a wet multi-plate clutch 63 for connecting / disconnecting power from the speed increasing gear 59. These two clutches 62, 63 are The piston member 65 fitted to the 4-crawler drive shaft 61 and movable in the axial direction is engaged and disengaged by moving to the left and right by the hydraulic pressure from the speed increasing control valve 64 (see FIG. 7).

  The wet multi-plate clutch 63 includes a hub member 66 that is spline-fitted to the 4-crawler drive shaft 61, a drum member 67 that is freely loosely fitted on the outer periphery of the hub member, and the piston member 65. The drum member 67 is formed with a gear 67 a that meshes with the speed increasing gear 59.

  The drum member 67 and the hub member 66 are provided with a large number of friction engagement plates, and hydraulic pressure is supplied to the oil chamber l of the piston member 65 through the oil path m and the orifice n of the 4-crawler drive shaft 61. Then, the piston member 65 presses the friction engagement plate against the urging force of the spring 69, and the drum member 67 and the hub member 66 rotate integrally, so that the power from the speed increasing gear 59 is transferred to the 4-crawler drive shaft. 61 (state shown in FIG. 6B).

  On the other hand, the ball clutch 62 is provided to face the wet multi-plate clutch 63 with the piston member 65 interposed therebetween, and a gear 70 that meshes with the standard gear 57 and a ball hole provided at the base of the gear 70. It is comprised from the ball | bowl 71 arrange | positioned and the extension part 65a of the piston member 65 extended along the 4 crawler drive shaft 61 toward the gear 70 side.

  The 4-crawler drive shaft 61 is formed with a tapered recess 61a at a position corresponding to the ball 71. The ball 71 is included in the extension 65a, and the piston member 65 is connected to the spring 69. When the urging force is applied to the gear 70 side, the ball 71 is pressed against the recess 61a by the extension portion 65a, and the gear 70 and the four crawler drive shaft 61 rotate together (the state shown in FIG. 6A). ).

  In addition, the distal end portion (the gear 70 side) of the extension portion 65a of the piston member 65 has an inner peripheral surface that is in contact with the ball 71 having a certain thickness, and hydraulic pressure is supplied to the oil chamber l so that the piston member 65 is wet multiplate. When moving to the clutch 63 side, the ball 71 contacts the thin portion of the extension portion 65a. Therefore, the ball 71 moves to the outer peripheral side and comes out of the concave portion 61a of the four crawler driving shaft 61, and the fixation between the four crawler driving shaft 61 and the gear 70 is released (state shown in FIG. 6B).

[Explanation about speed increase control]
Next, the speed increase control will be described. As described above, the speed change device 42 has the speed increasing switching speed change mechanism 51, and the speed increasing speed change speed changing mechanism 51 is a hydraulic pressure from the speed increasing control valve 64 of the hydraulic pressure control device (not shown) of the speed change device 42. Thus, the standard state and the acceleration state are switched. As shown in FIG. 7, the speed increasing control valve 64 controls the hydraulic pressure by a control signal from the hydraulic pressure command means 73 of the control unit (microcomputer unit) 72. The control unit 72 includes the hydraulic pressure command means 73, An acceleration switching execution means 75 and an acceleration instruction means 76 are provided.

  In addition, the control unit 72 is in a state where it cannot travel when traveling in a wet field such as the one shown in FIG. 2 or when at least one of the front and rear crawler travel devices 10 and 11 is idle in the wet field. A speed increasing function switch 77 operated by an operator in the case of (stat), an engine speed sensor 79 for detecting the engine speed, a vehicle speed sensor 80 for detecting the vehicle speed from the output shaft speed of the transmission 42, etc. Is connected.

  The speed increasing command means 76 is a control signal for switching the speed increasing switching transmission mechanism 51 to the speed increasing side to the speed increasing switching executing means 75 based on the speed increasing signal input when the speed increasing function switch 77 is turned ON. Is output. The speed increase switching execution means 75 to which the control signal from the speed increase command means 76 is input supplies the hydraulic pressure from the speed increase control valve 64 to the oil chamber l of the switching clutch mechanism 60 via the oil pressure command means 73, so The plate clutch 63 is engaged, and the speed increasing / changing speed changing mechanism 51 is switched to the speed increasing state.

  When the speed increasing function switch 77 is turned on, the speed increasing command means 76 is automatically in a stacked state (or running on soft ground) depending on the difference between the engine speed from the engine speed sensor 79 and the vehicle speed from the vehicle speed sensor 80. (State) may be determined, and a switching signal may be automatically output to the acceleration switching execution means 75.

  Next, the operation of the 4-crawler type tractor 1 according to this embodiment will be described. When the operator gets into the cabin 5, the engine is started, power is transmitted to the drive sprockets 19, 20 of the front and rear crawler travel devices 10, 11, and the tractor 1 is traveled by these four crawler travel devices 10, 11. .

  As shown in FIG. 2, the tractor 1 is submerged to a certain depth when entering a soft paddy field for plowing and plowing, but the rising parts A and C of the front and rear crawler traveling devices 10 and 11 are depressed. Touches the field and becomes an effective contact surface, reducing the contact pressure, and sinking the aircraft to a minimum. In particular, since the rear crawler traveling device 11 has a smaller elevation angle γ than the front crawler traveling device 10, the rising portion C is easily grounded due to the sinking of the rear crawler traveling device 11 and is newly grounded and effective. Since there are many lower portions C ′ serving as the ground contact surface, the ground contact pressure is low, and the tractor 1 travels smoothly.

  Further, when the crawler traveling devices 10 and 11 are driven in a state where they are submerged to a certain depth, in the case of a normal four crawler type tractor, the front end portions of the front and rear crawler traveling devices are submerged in the mud. The mud is pushed by the inclined surface above the front part of the front and receives a large running resistance, and the crawler running devices 10 and 11 of the front and rear are swung forward by the mud resistance, and the bottom of the field is further shaved. Although the crawler traveling devices 10 and 11 of the tractor 1 are disposed so as to sink, the front idler wheels 23 and 26 are disposed at a height that is more than half of the total height of the front crawler traveling device 10. In addition, since the rising portions A and C of the crawlers 31 and 32 are configured to become longer upward, the front portions of the crawler traveling devices 10 and 11 are not pushed and mud is pushed forward. Smoothly driven without oscillating.

By configuring the tractor 1 as described above, and to the arrangement of the front idler wheel 23 of the front crawler traveling units 10 to one or more of the height of half of the total height _{(H 2 ≧ H 1/2} ) The front idler wheel 26 of the rear crawler traveling device 11 is arranged at substantially the same height as the front idler wheel 23 of the front crawler traveling device 10 (H ₂ ≈H ₄ ). Even in a wet field that travels while sinking to a depth, mud is not pushed in front of the crawler travel devices 10 and 11. Therefore, the tractor 1 can run smoothly with less running resistance while the crawler running devices 10 and 11 are not swung forward and stuck even in a place where the ground is soft, such as a wet paddy field.

  Moreover, since the distance b between the front idler wheel 26 and the wheel 30 is longer than the front crawler traveling device 10 (b> a), the rear crawler traveling device 11 has the crawler traveling devices 10, 11. When sinking, the lower part C ′ of the rising part C is easily in contact with the farm scene, and the rising part C (C ′) that is in contact with the farm scene becomes an effective grounding surface, so that the contact pressure becomes low and the Can be reduced. Thereby, the driving performance of the tractor 1 in the wetland can be significantly improved in combination with the reduction of the driving resistance due to mud pushing.

A side view of a tractor concerning an embodiment of the invention. The side view which shows the wet field running state of the tractor which concerns on embodiment of this invention. The front view which shows the attaching part of the front part crawler traveling apparatus which concerns on embodiment of this invention. The side view of the front part crawler traveling device concerning an embodiment of the invention. The power transmission figure of the tractor concerning an embodiment of the invention. (A) Sectional drawing which shows the standard state of the speed-change switching transmission mechanism which concerns on this invention, (b) Sectional drawing which shows the speed-up state of the speed-change switching transmission mechanism which concerns on this invention. The block diagram of the tractor which concerns on embodiment of this invention.

Explanation of symbols

1 Tractor (4 crawler type vehicle)
2 traveling machine body 10 front crawler traveling device 11 rear crawler traveling device 16, 17 axle 19, 20 drive sprocket 21, 22 track frame 23, 26 front idler wheel 25, 27 rear idler wheel 29, 30 wheel 31, 32 crawler a Front-rear direction distance between the front idler wheel and the wheel of the front crawler traveling apparatus b b Front-rear direction distance between the front idler wheel and the wheel of the rear crawler traveling apparatus H ₁ Overall height H _{2 of the} front crawler traveling apparatus Front crawler travel device front idler wheel height H ₄ Rear crawler travel device front idler wheel height α Front crawler travel device crawler front elevation angle γ Rear crawler travel device crawler front elevation angle

Claims (2)

A drive sprocket mounted on the axle, a front idler wheel disposed at the front end of the track frame provided below, a rear idler wheel disposed at the rear end of the track frame, and a front idler wheel disposed between the front and rear idler wheels. In a four-crawler type vehicle provided with a pair of left and right crawler traveling devices each having a crawler wound around a roller wheel installed rotatably on the track frame,
The front idler wheel of the front crawler traveling device provided in front of the fuselage is disposed at a half or more of the total height of the front crawler traveling device, and the front idler wheel and the lower rolling wheel While increasing the elevation angle formed by
The rear crawler travel device provided with the front idler wheel at substantially the same height as the front idler wheel of the front crawler travel device,
4 crawler type vehicle characterized by the above. In the rear crawler traveling device, the front-rear direction distance between the front idler wheel and the wheel is longer than the front crawler traveling device, and the elevation angle thereof is the front crawler traveling device. Configured to be smaller than the elevation angle of the device,
The four-crawler type vehicle according to claim 1.

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