JP3368597B2 - Traveling gear for mobile agricultural machines - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling transmission device such as a combine, and can be used for a tractor having a transmission device in the form of a steering clutch, and other mobile agricultural machines. 2. Description of the Related Art In a steering transmission in which a steering clutch is disengaged to apply a steering brake, a steering brake is provided outside each of the left and right steering clutches. The steering brakes for the respective steering clutches are individually braked to perform steering or turning, and the left and right steering brakes are simultaneously braked to form a parking brake. In such an embodiment, the steering brake has a pair of left and right sides, which is complicated and heavy. SUMMARY OF THE INVENTION An object of the present invention is to provide a traveling transmission device which has a simple structure, can be reduced in size, and can perform a soft turning without damaging the field. The following technical measures were taken. That is, a working unit is provided at the front of the traveling chassis 7, and the rotational power from the engine is
The transmission is shifted by a hydraulic continuously variable transmission HST attached to the outside of the traveling transmission case 15 and the mechanical auxiliary transmissions 23 and 24 incorporated in the traveling transmission case 15, and the shifted rotational power is transmitted by the differential gear 3 and the steering clutch. In a mobile agricultural machine configured to transmit the left and right traveling axles 34L and 34R via the first and the first differential 1, the differential device 3 is incorporated in a traveling transmission case 15, and the differential shaft projects laterally from the left and right of the differential device 3. 2L and 2R have the same diameter gears 35L and 35R
The gears 35L, 35R are always meshed with the steering clutch gears 1L, 1R, and the rotation of the differential case 4 sandwiched between the gears 35L, 35R during the turning operation is shaken.
The traveling transmission device for a mobile agricultural machine is characterized in that the rotation ratio of the left and right traveling axles 34L, 34R is changed by braking with a brake . When the steering clutches 1, 1 are in a straight running state, the rotational power transmitted by the hydraulic continuously variable transmission HST and the mechanical auxiliary transmissions 23, 24 is transmitted to the left and right traveling devices. Then, the aircraft runs straight. When steering to one of the left and right sides, for example, when steering to the left or turning, the transmission to the left traveling device is cut off by disengaging the left steering clutch 1 and the left steering can be performed. it can. At this time, since the rotation of the differential case 4 is braked by the brake and the rotation of the differential case 4 is gradually reduced, the rotation of the left differential shaft 2L is also reduced. The traveling device on the left side is reversely driven. Therefore, the aircraft turns left. Further, the power is transmitted by the same operation in right-hand steering or turning. As described above, the present invention provides a hydraulic continuously variable transmission HST in which the working unit is provided at the front of the traveling chassis 7 and the rotational power from the engine is attached to the outside of the traveling transmission case 15.
And the mechanical auxiliary transmissions 23 and 24 incorporated in the traveling transmission case 15, and transmits the shifted rotational power to the left and right traveling axles 34 L and 34 R via the differential device 3 and the steering clutch 1. In the mobile agricultural machine configured to cause the differential device 3, the differential device 3 is incorporated in a traveling transmission case 15, and differential shafts 2L, 2R protruding laterally from right and left sides of the differential device 3 are provided with gears 35L, 35R having the same diameter.
These gears 35L, 35R are connected to the steering clutch gear 1L,
1R, and the gear 35L,
The rotation of the differential case 4 sandwiched between 35Rs is
Since the rotation ratio of the left and right traveling axles 34L, 34R is changed by braking, the shifting operation from the forward range to the reverse range can be performed easily and smoothly when the vehicle is going straight ahead. , Regardless of whether the aircraft is turned in the left or right direction, turn freely from the pivot turn to the large turn slowly, or the super pivot turn that turns one side in the opposite direction freely Can be. The differential case 4 that causes the left and right traveling axles 34L and 34R to generate a differential is provided with gears 35L and 35L in the traveling transmission case 15.
Since the steering clutches 1 and 1 are provided in a narrow space sandwiched between the 35Rs and are provided in close proximity to the differential case 4, these steering mechanisms can be compactly integrated in the traveling transmission case 15. It can contribute to downsizing of the mobile agricultural machine and can be manufactured at low cost. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A traveling transmission for a combine is exemplified. The combine is mounted on a chassis 7 having a pair of right and left crawler-type traveling devices 6, a threshing device 8, a Glen tank, and a steering device 9.
The cutting frame 14 having the grain stalk raising device 10, the feeding device 11, the cutting blade device 12, the grain stalk transport device 13 and the like is mounted on the shaft 1 above the transmission case 15 in front of the threshing device 8.
The lift cylinder 17 is provided so as to be rotatable up and down around 6, and the up and down movement is performed by expansion and contraction of a lift cylinder 17 by hydraulic pressure between the cutting frame 14 and the chassis 7. The grain stalks cut by the cutting device configured as described above can be transported and supplied to the feed chain 18 of the rear threshing device 8 for threshing. The traveling transmission case 15 has a hydraulic continuously variable transmission HST on one upper side, and transmits power from a drive shaft 19 of the engine to the input shaft 20. This hydraulic continuously variable transmission HS
T can continuously change the speed from the neutral position to the forward high-speed position or the reverse high-speed position by operating the transmission lever 21 of the control device 9. The output shaft of the hydraulic continuously variable transmission HST is connected to the transmission shaft 22 of the traveling transmission case 15 and meshes with the gear 27 of the steering clutch shaft 26 via the auxiliary transmission gear 23 and the counter shaft 25 of the counter gear 24. I do.
The clutch body 28 at the center of the steering clutch shaft 26 is provided with clutch claws 29 of a pair of left and right steering clutch gears 1L, 1R so as to engage with the tension of the springs 30L, 30R. The clutch pawls 29L, 2R are moved by moving the clutch gears 1L, 1R left and right against the springs 30L, 30R by operating a clutch shifter.
9R is separated from the clutch body 28 and the clutch shaft 2
6 to the steering clutch gears 1L, 1R. Each of the steering clutch gears 1L, 1R has counter gears 32L, 3 rotatable with respect to the counter shaft 31.
2R are always meshed with each other, and these counter gears 32L, 32
The sprocket shafts 34L, 34R of the right and left crawler traveling devices 6 are transmitted from the wheel gears 33L, 33R meshed with R. In such a traveling transmission device, the gears 35L, 35R are always meshed with the left and right steering clutch gears 1L, 1R, and a differential shaft 2L integrated with the gear 35L, and a gear 3L.
A differential (differential) device 3 is formed between the 5R and the integral differential shaft 2R. A disk brake 5 is provided on the outer periphery of a differential case 4 bearing the differential shafts 2L and 2R along the rotation direction.
The rotation of the differential case 4 is braked by clamping the disc brake 5 from both left and right sides with a brake shoe 37 by a brake cylinder 36. Reference numeral 38 denotes a brake unit having the brake cylinder 36, the brake shoe 37, and the like, which also serves as a case cover for opening and closing the opening 39 of the traveling transmission case 15. When the steering clutch 29L is disengaged, the transmission from the clutch body 28 to the left steering clutch 29L is cut off, so that the steering can be steered to the left by the transmission of the left traveling device 6. When the disc brake 5 is braked in this state, the rotation of the differential case 4 is stopped in accordance with the braking force, and the rotation of the differential shaft 2R driven from the steering clutch gear 1R through the gear 35R causes the differential device 3 to rotate. The reverse rotation of the left differential shaft 2L is transmitted by the action of
L, via the steering clutch gear 1L, etc.,
Can be transmitted and rotated in the direction opposite to the right side, and can turn sharply to the left side. In the hydraulic circuit 40 for operating the steering clutch and the disc brake, P is a hydraulic pump, T is a tank port, 41 is a lily valve, 42 is a steering control valve,
43 is a steering sensor; 44L and 44R are steering clutch cylinders for shifting the steering clutch gears 1L and 1R;
Reference numeral 5 denotes a brake cylinder that brakes the disc brake 5, 46 denotes an electromagnetic proportional solenoid valve, and 47 denotes a power steering valve that is manually operated. The operation of the electromagnetic proportional solenoid valve 46 is appropriately controlled to a degree of throttle, a speed, and the like by an output from the controller CPU based on detection of various conditions by sensors. While the cutting sensor 43 detects the cutting grain stalk, the cutting direction is controlled by switching the steering control valve 42 to actuate the steering clutch cylinder 44L or 44R to change the cutting stalk. Run along. At this time, the power steering valve 47 and the electromagnetic proportional solenoid valve 46 are open. Here, at the time of the steering turn, the power steering valve 47 or the electromagnetic proportional solenoid valve 46 is operated in the closing direction, so that the steering clutch cylinder 44 is operated.
The oil overflowing from L or 44R is sent to the brake cylinder 45, and the brake shooter 37 is operated to clamp the disc brake 5 to perform braking. Thus, the rotation of the differential case 4 is braked, and the differential between the differential shafts 2L and 2R is performed. In the electromagnetic proportional solenoid valve 46, an initial set pressure is changed by a change in current under the conditions detected by each sensor (FIG. 4). When the power steering lever is manually operated, the output pressure of the power steering valve 47 is controlled for each set initial pressure (FIG. 5). Therefore, even if the operating angle of the power steering lever is the same, the control pressure of the disc brake can be arbitrarily selected according to the current value of the proportional solenoid, and the turning radius under each condition can be made substantially the same. Can also be restored.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a transmission mechanism of a traveling transmission unit. FIG. 2 is a side view thereof. FIG. 3 is a hydraulic circuit diagram of a steering clutch and a brake. FIG. 4 is a graph showing a relationship between current and initial pressure of an electromagnetic proportional solenoid valve. FIG. 5 is a graph showing a relationship between an operation angle of a power steering lever and a disc brake control pressure in the controller. FIG. 6 is a side view of the combine. [Description of Signs] 1 Steering clutch 2 Differential shaft 3 Differential device 4 Differential case 5 Disc brake

Claims (1)

(1) A traveling unit is provided with a working unit at the front of the traveling chassis, and a hydraulic continuously variable transmission (HST) mounted on the outside of the traveling transmission case for traveling with the rotational power from the engine. Transmission case 15
The shift is configured to be shifted by the mechanical sub-transmissions 23 and 24 incorporated therein and to transmit the shifted rotational power to the left and right traveling axles 34L and 34R via the differential device 3 and the steering clutches 1 and 1. In the agricultural machine, the differential device 3 is incorporated in a traveling transmission case 15, and differential shafts 2L, 2R protruding laterally from left and right of the differential device 3 are provided with gears 35L, 35R having the same diameter.
35R always meshes with the steering clutch gears 1L, 1R,
A travel transmission device for a mobile agricultural machine, wherein during rotation operation, the rotation of the differential case 4 sandwiched between the gears 35L, 35R is braked to change the rotation ratio of the left and right traveling axles 34L, 34R. .