Crawler tractor

Abstract

The purpose of the invention is to enable a crawler tractor to brake and stop certainly without applying a load to an engine and a driving mechanism, and without complicated operation. An operation link links a conic linkage (53) which links a steering wheel (7) with a main speed change lever (55) of the crawler tractor, and with an operation mechanism of a brake pedal (54). A neutral return mechanism for the operation link is provided. The operation link neutral return mechanism comprises a hook-like cam lever (61). When the brake pedal is depressed, the main speed change lever is moved to its neutral position before braking force occurs, and then, the brake is actuated. Accordingly, engine brake is used effectively, and the brake can be miniaturized.

Description

[0001] The application for the present invention is a divisional application of the invention application whose international filing date is April 3, 2002, the international application number is PCT / JP02 / 03361, and the national application number is 02807467.X. Technical field [0002] The invention relates to a crawler tractor used for agricultural work. More specifically, it is about the drive mechanism, HST and brake mechanism of the speed change, travel and manipulation of the crawler tractor. Background technique [0003] As an existing hydraulic traveling agricultural machine with independent left and right crawler-type traveling parts, there is known a working vehicle (crawler tractor) provided with a hydraulic continuously variable transmission mechanism for traveling and a hydraulic continuously variable transmission mechanism for operation. ). [0004] In order to improve the operability of such a crawler tractor, it is important to reliably transmit, cut off, and brake...

AI Technical Summary

Problems solved by technology

Therefore, the driving HST is full of pressure, the output shaft is difficult to rotate, and a large power is required for starting, and the auxiliary transmission and gear switching may not be smoothly performed.

[0012] Regarding the cooling of the hydraulic oil, if the oil cooler for cooling the hydraulic oil used in the transmission mechanism is installed side by side with the condenser for the air conditioner and the radiator of the engine, the cooling effect may be reduced.

Moreover, sometimes the maintenance operation is complicated

[0013] Regarding the existing hydraulic piping configuration, it takes time to assemble, and it is necessary to close the hydraulic hole on the unused side every time when the hydraulic pressure is discharged forward and backward.

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