JP2006082707A - Semi-crawler type working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semi-crawler type working vehicle which dose not damage a field and enables small radius turning and has excellent steerability. <P>SOLUTION: The semi-crawler type working vehicle has a crawler frame 5 for longitudinally swingably supporting a crawler type running device 7 of a rear part of a vehicle body with respect to the vehicle body. The semi-crawler type working vehicle has a steering angle sensor 81 for detecting turning operation of the vehicle body, reversely rotating mechanism 73 for independently reversely rotating a pair of left and right crawler type running devices 7, respectively, and a front wheel accelerating driving mechanism 55 for changing over a front wheel 14 into a driving state and a non-driving state. When a detection value of the sensor 81 for detecting the steering angle of a steering wheel 17 exceeds a specified value, (a) the crawler type running device 7 on the inside of turning is reversely rotated and the front wheel 14 is shifted into a nondriving state or (b)the crawler type running device 7 on the inside of turning is reversely rotated and the front wheel 14 is accelerated. Accordingly, the field is not damaged and small radius turning is made possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semi-crawler type work vehicle having excellent steering performance in a field.

   In the tractor, which is a semi-crawler type work vehicle, the present applicant has developed a tractor having the following configuration in order to reliably steer the vehicle body with respect to the steering operation even when the front wheel is lifted. A patent application (Japanese Patent Laid-Open No. 2001-206239) has been filed.

In other words, the invention determines that the front wheel is lifted when the front wheel load sensor that detects the shared load of the front wheel detects that the shared load of the front wheel has decreased to a predetermined value or less, and controls the left or right brake solenoid. This is a semi-crawler type tractor that sends a signal to actuate the left and right brakes separately to reduce the rotation speed of the crawler inside the turn and turn the vehicle body in the steering direction.
In this specification, the left and right directions in the forward direction of the vehicle are referred to as left and right, respectively.
JP 2001-206239 A

In the semi-crawler type tractor as described above, a four-wheel drive is used to drive the field. They will not fit and will push the soil on the side of the tire and drag the tire to roughen the field.
An object of the present invention is to provide a semi-crawler type work vehicle that is capable of making a small turn without causing the field to be rough and having excellent steering performance.

The problems of the present invention are solved by the following means.
According to the first aspect of the present invention, a pair of left and right crawler type traveling devices (7) having a substantially triangular shape having a pair of left and right front wheels (14) at the front part of the vehicle body and a crawler drive sprocket (2) at the rear part of the vehicle body. And a steering angle sensor (81) for detecting a turning operation of the vehicle body in a semi-crawler type work vehicle including a crawler frame (5) that supports the crawler type traveling device (7) so as to be swingable back and forth with respect to the vehicle body. ), A reverse rotation mechanism (73) that independently reverses the pair of left and right crawler type traveling devices (7), and a front wheel acceleration drive mechanism (55) that operates by switching the front wheel (14) between a driving state and a non-driving state. ) And the detected value of the steering angle sensor (81) exceed a certain value, the reversing mechanism (73) reverses the crawler type traveling device (7) inside the turning, and the front wheels (14) are not driven. A Semikurora work vehicle provided with a controller (100) to be migrated.

  According to the second aspect of the present invention, a pair of left and right crawler type traveling devices (7) having a substantially triangular shape having a pair of left and right front wheels (14) at the front part of the vehicle body and a crawler drive sprocket (2) at the rear of the vehicle body. In a semi-crawler type work vehicle provided with a crawler frame (5) that supports the crawler type traveling device (7) so as to be able to swing back and forth with respect to the vehicle body, a steering angle sensor ( 81), a reverse rotation mechanism (73) that independently reverses the pair of left and right crawler type traveling devices (7), a front wheel acceleration drive mechanism (55) that can drive the front wheels at an increased speed, and a steering angle sensor When the detected value of (81) exceeds a certain value, the reverse rotation mechanism (73) reverses the crawler type traveling device (7) on the inside of the turn and the controller (100) for driving the front wheels at a higher speed. A Semikurora work vehicle equipped.

  According to the first aspect of the present invention, when the detected value of the steering angle sensor (81) exceeds a certain value, the crawler type traveling device (7) inside the turn is reversed and the front wheels (14) are brought into a non-driven state. Since it shifts, the front wheel rotates according to the turning radius, and the small turn is possible without damaging the field.

  According to the second aspect of the present invention, when the detected value of the steering angle sensor (81) exceeds a certain value, the crawler type traveling device (7) inside the turn is reversed and the front wheel (14) is accelerated. Thus, the front part of the vehicle body can be quickly moved in the turning direction, and a small turn is possible without damaging the field.

Embodiments of the present invention will be described below with reference to the drawings.
An embodiment of the present invention will be described below with respect to a semi-crawler type agricultural tractor (hereinafter referred to as a tractor) which is an example of a work vehicle. FIG. 1 shows a side view of a tractor according to an embodiment of the present invention.

  The tractor 10 mounts an engine 12 inside a hood 11 at the front of the vehicle body, and a clutch housing (not shown), a transmission case 13 and the like are integrally connected to the engine 12 to form a main frame of the vehicle body. A pair of wheel-type front wheels 14 are provided on both the left and right sides of the bonnet 11 so as to be rotatable about a center pivot 15. A steering post 16 is provided in the cabin 8 at the rear of the bonnet 11, and a steering handle is provided on the upper part. The front wheel 14 is steered by rotating the steering handle 17.

  The interior of the cabin 8 of the tractor 10 will be described. A traveling speed change lever 20 and a work equipment elevating lever 21 are provided on the side of the cockpit 19. A potentiometer (not shown) for detecting the operation angle is provided at the rotation base of the lever 21, and the height of the work machine R is adjusted so that the lever operation angle and a set angle of a lift arm 31 described later coincide with each other. The configuration is changed.

  Although not shown, the crawler frame 5 is a substantially “H” -shaped iron frame in a top view, and has a configuration in which left and right side portions have roller support portions 5 a provided in the front-rear direction. The front end of the roller support portion 5a has a cylindrical configuration so as to receive the support portion of the front driven wheel 3F. The front end of the roller support portion 5a is configured such that the support portion of the front driven wheel 3F is fitted in the cylinder by sliding it back and forth so that the front and rear position can be adjusted. Further, the first wheel 4a, the second wheel 4b, and the third wheel 4c are provided in order from the front on the wheel support portion 5a between the front and rear driven wheels 3F and 3R.

  The crawler drive sprocket 2 is provided at the tip of a pair of crawler drive sprocket shafts 1 projecting outward from left and right extending portions (not shown) of the rear portion of the transmission case 13, A large number of sprocket-shaped protrusions that mesh with a large number of engagement holes (not shown) of the crawler 6 are provided, and the crawler 6 is driven by these meshing.

  Next, the rear part of the mission case 13 of the tractor 10 will be described with reference to FIG. At the rear of the mission case 13, a lifting hydraulic cylinder 35A and an assist cylinder 35B are provided as actuators for lifting the work implement, and the lift arm 31 connected to the pistons of these cylinders (35A, 35B) is rotated up and down. The work machine R is lifted and lowered via the link mechanism 32. A lift arm angle sensor 33 is provided at the rotation base of the lift arm 31 so that the height of the work implement R can be indirectly detected.

  The controller (not shown) of the tractor 10 detects the output of the lift arm angle sensor 33 at regular intervals, and measures the lift speed dθ / dt of the lift arm 31. When the ascending speed dθ / dt is less than or equal to a certain value, the controller determines that the work implement R is heavy and activates the assist cylinder 35B.

  When the work machine R is not attached or when the light work machine R that does not require the assist cylinder 35B is attached, the tractor 10 is configured not to drive the assist cylinder 35B. And improve durability.

  Specifically, the oil flow rate to the assist cylinder 35B is controlled by a flow rate control valve (not shown), and when the work implement R is light or when the work implement R is not attached, the cylinder case of the lifting hydraulic cylinder 35A The oil is fed only (not shown) and the assist cylinder 35B is not operated, and the assist cylinder 35B is operated only when the work implement R is heavy.

FIG. 2 is a diagram showing a traveling transmission system of the tractor 1 having the transmission according to the embodiment of the present invention, and FIG. 3 is a flowchart when the turning control mode of the tractor 1 is set.
The power of the engine 12 is transmitted to the hydraulic two-stage switchable high / low speed switching device 40 via the main clutch 38 and further to the reverser mechanism 42. The reverser mechanism 42 switches the advancing direction of the airframe, and includes a forward clutch 42F and a reverse clutch 42R. When the forward clutch 42F is connected, the aircraft moves forward. Conversely, when the reverse clutch 42R is connected, the aircraft moves backward. By appropriately operating a reverse lever (not shown) provided on the side of the handle post 16 that supports the steering handle 17 in the front-rear direction, the reverser mechanism 42 is switched so that the aircraft can be moved forward or backward. Yes. The transmission 43 comprises a synchromesh gear type main transmission 43a capable of shifting in four stages and a constant mesh gear type auxiliary transmission 43b capable of shifting in three stages.

  The main transmission 43a has a conventionally well-known structure in which a shift is made by a hydraulic actuator (not shown), and the sub-transmission 43b moves the traveling shift (sub-shift) lever 20 in the front-rear direction and the left-right direction, for example. By operating along the mold lever guide, it is switched to three stages.

  More specifically, when the sub shift lever 20 is operated to move the front shifter 45 rearward, L speed (low speed) is obtained, and when the front shifter 45 is moved frontward, H speed (high speed) is obtained, and the rear shifter 46 is moved rearward. LL speed (ultra-low speed) is obtained, and the decelerated rotation is transmitted to the drive pinion shaft 47.

  The handle portion of the auxiliary transmission lever 20 is provided with two button switches (not shown) for acceleration / deceleration. When the acceleration switch is pressed, a hydraulic actuator (not shown) is operated to operate the main transmission. 43a is increased step by step, and conversely, when the deceleration switch is pressed, it is decelerated step by step.

  When switching the main transmission 43a, the reverser mechanism 42 is once returned to neutral by a command from the controller 100, and the reverser mechanism 42 is connected again after the shift is completed.

  The output from the transmission 43 is transmitted into a rear mission case (not shown) via a drive pinion shaft 47 that is an auxiliary transmission output shaft. In this rear transmission case, a support shaft 50 is provided between the left and right side walls, and a bevel gear 54 that meshes with a bevel gear 53 fixed to the pinion shaft 47 is fixedly provided at a position slightly deviated from the center of the support shaft 50. A brake device 51 is provided at a position substantially opposite to the left and right sides of 54.

  Then, a brake pedal (not shown) and the brake device 51 are connected by a link mechanism (not shown), and the disc of the brake device 51 is crimped by depressing the brake pedal, whereby the support shaft 50 rotates, that is, the left and right crawler type travel. It is comprised so that rotation of the apparatuses 7 and 7 may be braked. Further, a reduction gear set 71 is provided at both left and right ends of the support shaft 50, and the rotation of the bevel gear 54 is transmitted to the input shaft 72 in the rear axle case via the reduction gear set 71.

  A crawler reversing mechanism 73 is disposed inside the rear axle case. The crawler reversing mechanism 73 is configured to have the input shaft 72 and an output pivotally mounted coaxially with the input shaft 72 on one end side of the input shaft 72. Shaft 74, planetary gear mechanism 75 interposed between input shaft 72 and output shaft 74, and forward / reverse clutch portion 79 (wet multi-plate type forward rotation clutch) provided on carrier 76 of planetary gear mechanism 75. 77 (vehicle body outer side) and reverse clutch 78 (vehicle body inner side).

  The rotation of the carrier 76 of the planetary gear mechanism 75 is stopped and the rotation of the input shaft 72 is gradually decelerated to the output shaft 74 by pressing the internal piston of the reverse clutch 78 toward the vehicle body in response to an energization command from the controller 100. Then, the output shaft 74 is stopped and then reversely rotated.

  More specifically, the forward rotation clutch 77 is normally connected to the carrier 76 by its internal spring. In this case, the rotation of the input shaft 72 is rotated via the forward rotation clutch 77 to the planetary gear mechanism 75. And is transmitted to the input side sun gear S1 of the planetary gear mechanism 75 that rotates through the clutch portion 79 and rotates together with the input shaft 72.

  As a result, there is no rotational difference between the input side sun gear S1 and the carrier 76 in the planetary gear mechanism 75, so the forward / reverse clutch portion 79 and the planetary gear mechanism 75 rotate together. That is, the rotation of the input shaft 72 is transmitted to the output shaft 74 as it is.

  Further, when the internal piston of the reverse clutch 78 is operated to the inside of the vehicle body, the forward clutch 77 enters a half-clutch state against the urging force of the spring in the forward clutch 77.

  As a result, a difference occurs between the rotation speed of the carrier 76 of the planetary gear mechanism 75 and the rotation speed of the input sun gear S1 (this difference in rotation speed is compensated by the rotation of the counter gear C). Therefore, the rotation of the input shaft 72 gradually increases. The speed is reduced, and the rotation of the carrier 76 is transmitted to the output shaft 74 via the output-side sun gear S2.

  Further, when the internal piston of the reverse rotation clutch 78 is moved to the inside of the vehicle body, the normal rotation clutch 77 is completely inactivated. Thereby, the rotation of the carrier 76 of the planetary gear mechanism 75 and the rotation of the input side sun gear S1 are offset by the rotation of the counter gear C, and the output shaft 74 is not rotated.

Further, when the internal piston of the reverse rotation clutch 78 is further moved to the inside of the vehicle body, the reverse rotation clutch 78 is brought into a completely connected state through the connection in the half clutch state. Since the drive disk of the reverse clutch 78 is integrally engaged with the rear axle case, the rotation of the carrier 76 of the planetary gear mechanism 75 gradually stops as the reverse clutch 78 changes from the half-clutch state to the connected state. The rotation of the side sun gear S <b> 1 is transmitted to the output shaft 74 through the counter gear C while being reversely rotated and gradually increased in speed.
The driving force from the output shaft 74 is transmitted to the crawler driving sprocket shaft 1 through the reduction planetary gear mechanism 80.

  Further, the power branched immediately before the drive pinion shaft 47 is transmitted to a front wheel speed increasing device 55 incorporated in the front wheel drive system, and the front wheel speed increasing device 55 can rotate the front wheel 14 at a high speed when turning. it can.

  The front wheel speed increasing device 55 includes a speed increasing clutch 56 and a constant speed clutch 57, and both the clutches are normally in a disconnected state, and the tractor travels in 2WD. Further, during 4WD traveling, the constant speed clutch 57 is connected, and the front wheel 14 and the crawler traveling device 7 are in a 4WD traveling state in which the peripheral speeds are substantially equal, and the speed is increased only when the steering handle 17 is rotated more than a predetermined angle in the field. The clutch 56 is connected so that the front wheel 14 rotates faster than the crawler type traveling device 7.

  The output of the front wheel speed increasing device 55 is transmitted from the output shaft 59 to the front wheel drive shaft 60, and a tire-crawler switching device 61 is provided between the output shaft 59 and the wheel drive shaft 60. When the crawler is used (the left side of the drawing), the tire-crawler switching device 61 increases the peripheral speed of the crawler compared to the case where the tire is used for the front wheel 14 (the right side of the drawing). Therefore, to prevent this, when using a crawler, the number of revolutions of the front wheels is reduced compared to when using a tire. This switching is performed manually.

  A front wheel differential device 62 is provided at the front portion of the front wheel drive shaft 60, and the front wheels 14 and 14 are driven through front wheel final reduction gear mechanisms 63 and 63 provided on the left and right sides of the front wheel differential device 62.

  In FIG. 2, a PTO clutch 64, a PTO drive shaft 65, a PTO transmission 66 capable of switching between high and low, a PTO shaft 67, and a PTO forward / reverse switching device 68 are provided for PTO operation.

  Rotational power from the engine 12 is constantly transmitted to the PTO clutch 64. When the PTO clutch 64 is connected, the PTO drive shaft 65 is rotated, and when the PTO clutch 64 is disconnected, the PTO drive shaft 65 stops rotating.

  In the semi-crawler type tractor provided with the gear transmission mechanism shown in FIG. 2, the crawler type traveling device 7 can turn sharply (a turn in which the crawler type traveling device 7 on the inside of the turn reverses) when the semi-crawler is mounted. And durability of the crawler part can be improved.

  As shown in FIG. 2, a front wheel turning angle sensor 81 is provided in the front wheel steering section, a sensor 82 for detecting a tire-crawler switching operation is disposed in the vicinity of the tire-crawler switching device 61, and a switching lever of the reverser mechanism 42. A forward / reverse lever position sensor 83 is provided in the vicinity. The output signals of these sensors 81, 82, 83 are transmitted to the controller 100. The controller 100 controls the operation of the clutch of the front wheel speed increasing device 55 and the operation of the clutch of the forward / reverse clutch portion 79, so that the crawler is in the rapid turning mode. Thus, the front wheel speed increasing device 55 is switched to the front wheel speed increasing mode.

  In this way, the rapid turning mechanism of the crawler type traveling device 7 and the speed increasing mechanism of the front wheel 14 can be controlled together, and a new turning system can be configured, and a small turn can be made without damaging the field. This is because if the crawler type traveling device 7 on the inner side of the turning is reversed, the peripheral speed of the front wheel 14 may be insufficient and the field may be roughened. Therefore, by cutting the driving force of the front wheel 14, the front wheel is set according to the turning radius. Rotating, the vehicle can turn slightly, and the headland can be prevented from becoming rough.

In general, it has already been described that the crawler type traveling device 7 tends to move forward while traveling on a soft field. FIG. 4 and FIG. Show.
The crawler type traveling device 7 shown in the side view of FIG. 4 and the rear view of FIG. 5 is provided with an arm 84 having a fulcrum 84a directly below the shaft 1 of the drive sprocket 2 connecting the crawler frame 5 and the vehicle body. A piston-type damper 87 having a spring 85 in the forward direction from 84 a is provided, and the front-up swing of the crawler 7 is suppressed by a spring 85 inside the damper 87 provided on the frame 5.

  With the above configuration, it is possible to prevent the front side of the frame 5 from being raised and the traction force from being lowered during normal work. Further, when the vehicle is over the heel or the like, the damper 87 is subjected to its own weight, and the spring 85 is compressed and swings.

  The crawler type traveling device 7 is also provided with an adjusting screw 86 capable of adjusting the spring load, so that the spring force of the crawler frame 5 during the work is adjusted according to the field conditions. Can be adjusted.

  In adjusting the spring load, the length L between the tip of the wheel frame 5d and the swing fulcrum 84a is expanded and contracted in a state where the swing fulcrum 84a is not connected by the adjusting screw 86. When the swing fulcrum 84a is connected, the length L is always constant in the horizontal state, so that the set load of the spring 86 can be changed.

  Further, the rearward swing of the vehicle is restricted by a stopper 89 provided behind the wheel frame 5.

  The present invention can be applied to a work vehicle such as a semi-crawler type tractor that can perform a small turn without roughening the field but has excellent steering performance.

It is a left view of the tractor of the Example of this invention. It is a power diagram of the tractor of FIG. It is a flowchart of the operation control of the tractor of FIG. It is a side view of the crawler traveling device of the tractor of FIG. It is a rear view of the crawler traveling apparatus of the tractor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crawler drive sprocket shaft 2 Crawler drive sprocket 3F, 3R Front and rear driven wheels 4a, 4b, 4c Roller 5 Crawler frame (support member) 5a Roller support 6 Crawler 7 Crawler type traveling device 8 Cabin 10 Tractor 11 Bonnet 12 Engine 13 Mission case 14 Front wheel 15 Center pivot 16 Steering post 17 Steering handle 19 Pilot seat 20 Shifting lever 21 Lifting lever 31 Lift arm 32 Link mechanism 33 Lift arm angle sensor 35A Lifting hydraulic cylinder 35B Assist cylinder 38 Main clutch 40 High / low speed switching device 42 Reverser mechanism 42F Forward clutch 42R Reverse clutch 43 Transmission 43a Main transmission 43b Subtransmission 45, 46 Shifter 47 Drive pinion shaft 0 Support shaft 51 Brake device 53, 54 Bevel gear 55 Front wheel speed increasing device 56 Speed increasing clutch 57 Constant speed clutch 59 Output shaft 60 Front wheel drive shaft 61 Tire-crawler switching device 62 Front wheel differential device 63 Front wheel final reduction gear mechanism 64 PTO clutch 65 PTO drive shaft 66 PTO transmission device 67 PTO shaft 68 PTO forward / reverse switching device 71 Reduction gear set 72 Input shaft 73 Crawler reversing mechanism 74 Output shaft 75 Planetary gear mechanism 76 Carrier 79 Forward / reverse clutch portion 77 Forward clutch 78 Reverse clutch 80 Deceleration planetary gear mechanism 81 Front wheel turning angle sensor 82 Tire-crawler switching sensor 83 Forward / reverse lever position sensor 84 Arm 85 Spring 86 Adjustment screw 87 Damper 89 Stopper 100 Controller R Work machine S1, S2 Sun gear

Claims (2)

A pair of left and right front wheels (14) are provided at the front of the vehicle body, and a pair of left and right crawler type traveling devices (7) having a crawler driving sprocket (2) at the apex are provided at the rear of the vehicle body. In a semi-crawler type work vehicle including a crawler frame (5) that supports the device (7) so as to be swingable back and forth with respect to the vehicle body,
A steering angle sensor (81) for detecting a turning operation of the vehicle body;
A reversing mechanism (73) for independently reversing the pair of left and right crawler type traveling devices (7);
A front wheel acceleration drive mechanism (55) that operates by switching the front wheel (14) between a driving state and a non-driving state;
When the detected value of the steering angle sensor (81) exceeds a certain value, the reversing mechanism (73) reverses the crawler type traveling device (7) inside the turn and the front wheel (14) shifts to a non-driven state. (100). A semi-crawler type work vehicle. A pair of left and right front wheels (14) are provided at the front of the vehicle body, and a pair of left and right crawler type traveling devices (7) having a crawler driving sprocket (2) at the apex are provided at the rear of the vehicle body. In a semi-crawler type work vehicle including a crawler frame (5) that supports a device (7) so as to be swingable back and forth with respect to the vehicle body,
A steering angle sensor (81) for detecting a turning operation of the vehicle body;
A reversing mechanism (73) for independently reversing the pair of left and right crawler type traveling devices (7);
A front wheel acceleration drive mechanism (55) capable of increasing the speed of the front wheels;
When the detected value of the steering angle sensor (81) exceeds a certain value, the reverse rotation mechanism (73) reverses the crawler type traveling device (7) inside the turn and the controller (100) for driving the front wheels at a higher speed. A semi-crawler type work vehicle characterized by comprising.

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