JP3658799B2 - Sub-transmission operation device for tractor - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a sub-transmission operation device that operates a sub-transmission device in traveling transmission of a tractor.
[0002]
[Background Art and Problems to be Solved by the Invention]
In the tractor drive transmission, especially in the sub-low speed position (creep) of the auxiliary transmission, the gear operating load is large and difficult to operate. It is difficult to smoothly remove the gear from the low speed position.
[0003]
[Means for Solving the Problems]
The present invention has been proposed in view of the above-mentioned problems, and has taken the following technical means.
That is, the tractor is provided with a main clutch 4 and a clutch pedal 18 for turning the main clutch 4 on and off, and at the rear end of the transmission of the main clutch 4, the reverser shaft 25 is linked from the neutral state to the forward / reverse side. The main transmission 3 that is electrically controlled and switched by the actuators 31 and 32 in conjunction with the clutch 20 and the reverser shaft 25 and the auxiliary transmission 2 that is switched by the operation of the auxiliary transmission lever 1 are provided to transmit in this order. The sub-transmission device is configured to be capable of four-stage shifting between an ultra-low speed position LL with a large reduction ratio and a low-speed position L, a medium-speed position M, and a high-speed position H with a smaller reduction ratio, and the rotation base of the clutch pedal 18 the switch 19 for detecting a cut in the main clutch 4 provided on the when the switch 19 clutch pedal 18 is depressed is oN, the River cherry Tsu 20 is a neutral state, when the switch 19 is turned ON and auxiliary shift lever 1 is in the ultra-low speed position LL is characterized in that the main speed change device 3 is provided with a neutral position relay circuit 5 so that the neutral state It is set as the structure of the subtransmission operating device of a tractor.
[0004]
[Action]
Transmission of the traveling wheels by the engine is performed through the main clutch 4, the reverser shaft 25, the main transmission 3, the auxiliary transmission 2, and the like. The sub-transmission device 2 causes each sub-transmission transmission from the ultra-low speed position LL to the low-speed position L, the medium-speed position M, the high-speed position H, etc. by selecting the sub-transmission gears G11 to G14 by operating the sub-transmission lever 1. be able to. Based on the selection of the auxiliary transmission gears G11 to G14, the main transmission 3 selects the main transmission gears G1 to G4 by electronic output from the controller based on the set traveling speed of the steering, and the set traveling speed. The traveling transmission that suits is performed.
[0005]
【The invention's effect】
And depression-free clutch pedal 18 to switch the auxiliary speed change device 2, the main clutch 4 reverser clutch 24 with is cut is to reduce the interlocked load reverser shaft 25 is in the neutral position, the congestion of the main speed change device 3, cut When the sub-shift lever 1 is in the ultra-low speed position LL, not only the main clutch 4 and the reverser clutch 24 but also the main transmission 3 is simultaneously returned to the neutral position by the neutral position relay circuit 5 when the sub-shift lever 1 is in the ultra-low speed position LL. The clutch 35 of the transmission 2 is smoothly disengaged.
In addition, this configuration can be simplified because the neutral position relay circuit 5 is incorporated in the electronic operation circuit portion of the main transmission 3.
[0006]
【Example】
The tractor vehicle body integrally connects the clutch housing 6 and the transmission case 7 from the front engine E. The front axle housing 8 supports the front axle housing on the front part of the engine E. A front wheel 10 that can be steered by a steering handle 9 is mounted on the left and right sides, and a rear axle housing is provided on the left and right sides at the rear of the transmission case 7 to mount a rear wheel 12. 14 fenders, 15 is a cockpit, and 16 is a lift arm, which is connected to a three-point link mechanism or the like to raise and lower a working machine connected to the rear part of the vehicle body.
[0007]
This tractor has a four-wheel drive traveling configuration in which the engine E is driven to travel by transmitting the front wheel 10 and the rear wheel 12, and has a PTO shaft 17 that interlocks the work machine at the rear end of the transmission case 7. The main clutch 4 has a wet single plate type or a wet multi-plate type that can be cut by stepping on the clutch petal 18, and a clutch switch 19 to a sensor for detecting the stepping on the clutch petal 18 are provided. .
[0008]
The reverser clutch 20 driven through the main clutch 4 is a wet multi-plate form, and a forward clutch gear G21 that is linked from a clutch shaft 21 rotated from the main clutch 4 via a forward rotation gear 22 and a reverse rotation gear 23. And the reverse clutch gear G22, and the hydraulic clutch 24 is connected to the forward clutch gear G21 from the neutral position N on the reverser shaft 25 so that the forward position F is interlocked and connected to the reverse clutch gear G22. To interlock the reverse position R.
[0009]
The main transmission 3 linked with the reverser shaft 25 of the reverser clutch 20 includes a countershaft 27 having counter gears 26, and a gearshift having meshing main transmission gears G1 to G4 and clutches 28 and 29 in each counter gear 26. A shaft 30 is provided in parallel, and the clutch 28 is engaged with the main transmission gear G1 from the neutral position to be the first speed, and is engaged with the gear G2 to be the second speed, and the clutch 29 is moved from the neutral position to the main transmission gear G3. It can be meshed to the third speed and meshed with the gear G4 to be the fourth speed.
[0010]
The shifter actuators 31 and 32 of the clutches 28 and 29 are composed of electromagnetic solenoids, electromagnetic solenoid valves or the like, and are configured to be electronically switched and controlled by an output from a controller CPU having a microcomputer. Sub-transmission shafts 33 and 34 are provided in parallel behind the transmission shaft 30. Sub-transmission gears G 2 and G 4 and a clutch 35 for switching between them are provided on the sub-transmission shaft 33. Are provided with auxiliary transmission gears G1, G3 and a clutch 35 for switching between them. By switching the auxiliary transmission clutches 35 and 36 by operating the auxiliary transmission lever 1, the high speed position H of the auxiliary transmission is engaged with the clutch 36 from the neutral position to the auxiliary transmission gear G4 side, and the transmission shaft 30 It is linked to the sub-transmission shaft 34 via the sub-transmission shaft 33, the gear 37, etc., and becomes a transmission system path to the pinion gear 38. Further, the intermediate speed position M is transmitted from the transmission shaft 30 through the gear 39 to the auxiliary transmission shaft 34 from the auxiliary transmission gear G3 and the clutch 35 by engaging the clutch 35 from the neutral position to the auxiliary transmission gear G3 side. It becomes a system.
[0011]
Further, the low speed position L of the auxiliary transmission is engaged from the transmission shaft 30 to the transmission shaft 34 through the gears 39, G2, the clutch 36, the transmission shaft 33, the gear 37, etc. by engaging the clutch 36 toward the auxiliary transmission gear G2. Be transmitted. The ultra-low speed position LL is transmitted from the transmission shaft 30 to the transmission shaft 34 via the gear 39, the gears G2 and G1, the clutch 35, and the like by engaging the clutch 35 to the gear G1 side.
[0012]
Reference numeral 40 denotes a rear differential device, which receives a transmission from the pinion gear 38 and differentially transmits it to the left and right axles 13. 41 and 42 are clutches that can be switched between normal four-WD transmission and double-speed four-WD transmission that transmits the front wheel 10 to twice the speed of the rear wheel 12. Reference numeral 43 denotes a front wheel transmission shaft that is transmitted to the axle 11 of the front wheel 10 via a front differential device.
[0013]
A switch 19 for detecting depression of the main clutch petal 18 is input to the controller CPU, and an actuator 44 for turning on and off the reverser clutch 24 on the output side, and actuators 31 and 32 for turning on and off the clutches 28 and 29 of the main transmission 3. Etc. are provided to output solenoids 45F, 45R, 46-49. Further, shift position switches 50 to 53 by the sub-shift lever 1 are provided, and among these, an input circuit of the ultra-low speed position switch 50 is a relay switch R2 that is operated by turning on the clutch switch 19 when the main clutch petal 18 is depressed. Provided, the relays R2 and the ultra-low speed position switch 50 are turned on to turn off the outputs of the solenoids 46 to 49, and the clutches 28 and 29 in the main shift position are operated to the neutral position N. It has become.
[0014]
The relay switch R1 is provided in a circuit of reverser solenoids 45F (forward) and 45R (reverse), and the reverser clutch 24 is set to a neutral position when the main clutch 4 is disengaged. If the traveling speed adapted to the work is set in advance during the tractor work travel, the main transmission 3 can be operated by manually operating the sub-shift lever 1 and selecting the appropriate shift positions LL, L, M, H. The first to fourth gears are automatically shifted by the output from the controller CPU. At this time, when the sub-shift lever 1 is operated to shift, the main clutch 4 is disengaged by the depression of the main clutch petal 18 and the clutch switch 19 is turned on. When the relay switch R1 is turned off, the forward reverser solenoid 45F and the reverse drive Due to the reverser solenoid 45R, the reverser clutch 24 is in a neutral position, and the interlocking load of the reverser shaft 25 is reduced, so that the auxiliary transmission device 2, the main transmission device 3 and the like are smoothly turned on and off.
[0015]
At this time, in the sub-shift operation at the ultra-low speed position LL, the solenoids 46 to 49 of the main transmission 3 from the controller CPU are not energized by turning off the main clutch 4 and turning off the relay switch R2 together with the relay switch R1. The main transmission clutches 28 and 29 are in the neutral position N. Therefore, the interlocking load of the transmission shaft 30 is reduced, so that the auxiliary transmission clutch 35 is smoothly detached from the auxiliary transmission gear G11, and the auxiliary transmission at the ultra-low speed position LL is achieved. The return operation to the neutral position N of the lever 1 can be easily performed.
[0016]
In FIG. 4, the difference from the above example is that a switch or a sensor for detecting that the transmission clutches 28 and 29 by the transmission solenoids 46 to 49 of the main transmission 3 have entered any of the main transmission gears G1 to G4. 54, 55, 56, 57 are provided, the switch 50 for detecting the ultra-low speed position LL is turned ON, and the main transmission 3 is shifted to the first speed position or the second speed position, and these sensors 54 or 55 detect it. Only when the clutch switch 19 is turned on by stepping on the main clutch petal 18, the output signals of the main transmission solenoids 46 and 47 are stopped and the main transmission clutch 28 is set to the neutral position. This facilitates removal of the auxiliary transmission lever 1 at LL.
[0017]
In FIG. 5 and FIG. 1, after the differential lock with the differential lock petal 58 is performed, if the differential lock claw 60 is not cut even if the differential lock petal 58 is released, the steering brake 59 is automatically operated to automatically activate the differential lock 59. Is to be released. In a tractor having an automatic lift brake control that automatically raises the lift arm 16 to raise the work machine to the non-working position and applies the steering brake 59 by steering the steering handle 9. When the differential lock claw 60 provided in the rear differential device 40 interlocked with the rear wheel 12 is used during straight traveling and the left and right rear wheels 12 are rotated integrally, the driver steps on the differential lock petal 58 to perform the differential lock. If the diff lock claw 60 is lifted for steering turning and the like, the diff lock claw 60 may not come back because the thrust load is received, and the diff lock may not be released.
[0018]
At such time, the petal sensor 61 for detecting that the depression of the differential lock petal 58 has been released and the differential lock sensor 62 for detecting the differential lock position of the differential lock pawl 60 are used to release the brake of the steering brake 59 at the time of detection. It is designed to work intermittently at intervals of T seconds. As a result, the differential lock claw 60 can easily return to the differential lock release. At this time, the diff lock can be released earlier by controlling the output so that the left and right steering brakes 59 are alternately applied. If the diff lock is not released even if the steering brake 59 is applied lightly, an automatic alarm may be issued with a buzzer or a ramp to automatically decelerate the traveling shift to a low speed range or to automatically stop traveling.
[Brief description of the drawings]
FIG. 1 is a relay circuit diagram.
FIG. 2 is a transmission mechanism diagram.
FIG. 3 is a side view of a tractor.
FIG. 4 is a control circuit diagram showing a partially different embodiment and a flowchart thereof.
FIG. 5 is a flowchart of differential lock release control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sub transmission lever 2 Sub transmission 3 Main transmission 4 Main clutch 5 Neutral position relay circuit LL Very low speed position L Low speed position M Medium speed position H High speed positions G1-G4 Main transmission gears G11-G14 Sub transmission gear

Claims (1)

A tractor including a main clutch 4 and a clutch pedal 18 for turning the main clutch 4 on and off. A reverser clutch 20 that interlocks the reverser shaft 25 from the neutral state to the forward / reverse side after the transmission of the main clutch 4. A main transmission 3 that is electrically switched and controlled by actuators 31 and 32 in conjunction with the reverser shaft 25, and a sub-transmission 2 that is switched by the operation of the sub-transmission lever 1 are provided to transmit in this order. The device is configured to be capable of four-speed shifting, an ultra-low speed position LL with a large reduction ratio, and a low speed position L, a medium speed position M, and a high speed position H with a smaller reduction ratio. the switch 19 for detecting a cut in the main clutch 4 provided, wherein when the switch 19 clutch pedal 18 is depressed is ON, the reversal clutch 20 Becomes a neutral state, when the switch 19 is turned ON and auxiliary shift lever 1 is in the ultra-low speed position LL in the tractor, characterized in that the main speed change device 3 is provided with a neutral position relay circuit 5 so that the neutral state Sub-shift operation device.

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