JP2020103112A - Transmission for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably stop traveling by applying a parking brake to a traveling device when the traveling device is neutrally moving forward and backward in a work vehicle in which the power of an engine is transmitted to the traveling device via the stepless speed change device. The challenge is to let them do it. SOLUTION: In a transmission of a work vehicle in which a traveling device 3 is made capable of forward / backward shifting by a continuously variable transmission 2, a main shifting means 4 for switching the continuously variable transmission 2 to forward / backward shifting is shifted to a neutral position. The neutral detecting means 6 is provided, and when the neutral detecting means 6 detects the neutrality, the parking brake 8 is activated. [Selection diagram] Fig. 1

Description

The present invention relates to a transmission of a work vehicle equipped with a work machine such as a seedling transplanting device.

Patent Document 1 describes a brake operating mechanism of a work vehicle equipped with a seedling transplanter.

This brake operating mechanism is made operable by a hand brake provided outside the machine, which is provided with a brake pedal that is depressed in the cockpit to operate the brake.

The work vehicle drives the work machine and the traveling device by the power of the engine mounted on the machine body, and drives the work machine while traveling.

Japanese Unexamined Patent Publication No. 2018-130098

However, when the traveling device is driven from the engine through the hydraulic continuously variable transmission and the work machine is driven by power transmission different from that of the hydraulic continuously variable transmission, the longitudinal shift of the hydraulic continuously variable transmission is set to neutral. Although it is possible to drive the work machine and perform a trial run while stopping the travel, the brake is applied to the travel device because the power transmission between the travel device and the engine is cut off in the neutral position of the hydraulic continuously variable transmission. If you stop on a slope without taking this, the aircraft will descend down the slope due to its own weight, so it is necessary to operate the parking brake in a timely manner.

The present invention relates to a work vehicle in which the power of an engine is transmitted to a traveling device via a continuously variable transmission, and a parking brake is applied to the traveling device to reliably stop traveling when the continuously variable transmission is moving forward and backward. It is an issue.

The problems of the present invention are solved by the following technical means.

According to the invention of claim 1, in a transmission of a work vehicle in which the traveling device 3 can be moved forward and backward by the continuously variable transmission 2, the main transmission means 4 for switching the continuously variable transmission 2 to forward and backward transmission is shifted to the neutral position. The work vehicle transmission is characterized in that neutral detection means 6 for detecting that the vehicle has been operated is provided, and when the neutral detection means 6 detects neutral, the parking brake 8 is activated.

According to the second aspect of the present invention, the sub-transmission means 5 for switching the traveling speed between high and low is provided subsequent to the main transmission means 4, and when the parking brake 8 is actuated, the sub-gear stage 5 is forcibly returned to the neutral state and gear shifting is disabled. The work vehicle transmission according to claim 1.

The invention of claim 3 provides the transmission of a work vehicle according to claim 1, wherein the main transmission means 4 can release the parking brake 8 only in the neutral position.

In the invention of claim 1, since the parking brake 8 is activated when the main transmission means 4 is shifted to the neutral position, the operation of the main transmission means 4 to the neutral position brings the work vehicle into a reliable stopped state in which the parking brake 8 is effective. It can be done, and the trial run of the work machine can be safely performed without moving the vehicle body even when the vehicle is stopped on a slope.

According to the invention of claim 2, in addition to the effect of claim 1, the auxiliary transmission means 5 becomes neutral when the parking brake 8 is applied and the parking is stopped, so that the parking brake 8 is released and the vehicle suddenly starts. There is nothing.

According to the invention of claim 3, in addition to the effect of claim 1, since the main transmission means 4 is at the neutral position when the parking brake 8 is released, the traveling device 3 does not start traveling, which is safe.

It is a control block diagram of power transmission. It is a top perspective view of a main shift lever. It is a top view of an auxiliary shift lever.

Embodiments of the present invention will be described below with reference to the examples shown in the drawings.

FIG. 1 is a block diagram of a power transmission and an operation system.

The power of the engine 1 is transmitted to the traveling device 3 via the main transmission unit 4, the auxiliary transmission unit 5, and the continuously variable transmission unit 2 to travel, and the power branched from the engine 1 is transmitted to the working unit 10 via the clutch 9. Be done and work.

Further, in the continuously variable transmission 2, the main transmission means 4 performs forward/backward switching and the traveling speed is changed, the auxiliary transmission means 5 switches the traveling speed between high and low, and the neutral sensor 6 of the main transmission means 4 performs the main transmission. It is detected that the means 4 has been shifted to the neutral position.

Further, the traveling device 3 is provided with a parking brake 8 operated by the control unit 7.

FIG. 2 shows the operation portion of the main transmission lever 4 which is the main transmission means, and moves the transmission groove 11 from the neutral position to the front and rear to shift forward and backward and the traveling speed. A neutral sensor 6 is provided at the neutral position to detect that the main transmission lever 4 has been shifted to the neutral position.

FIG. 3 shows the operation portion of the auxiliary transmission lever 5, which is the auxiliary transmission means, so that the transmission groove 13 is moved to the neutral position 13A, the pita planting speed position 13B, the planting speed position 13C, and the road speed position 13D. Further, the lock solenoid 12 is provided at the neutral position 13A so that the control section 7 operates the lock solenoid 12 when the parking brake 8 is activated to restrict the shift of the auxiliary shift lever 5 to a position other than the neutral position 13A. There is. Further, when the parking brake 8 is operated, the control unit 7 operates an electric cylinder (not shown) that moves the auxiliary transmission lever 5 to return the auxiliary transmission lever 5 to the neutral position 13A.

Then, the main shift lever 4 can be pushed down in the neutral position, and when the neutral sensor 6 pushes down the main shift lever 4 in a detected state, the control unit 7 outputs the brake 8 to brake. At the same time, the lock solenoid 12 fixes the auxiliary transmission lever 5 at the neutral position 13A.

Further, if the auxiliary gear shift lever 5 is not in the neutral position 13A, the main gear shift lever 4 can be shifted back and forth, but conversely, if the main gear shift lever 4 is not in the neutral position, the auxiliary gear shift lever 5 locks the solenoid 12 It does not return to the neutral position 13A.

Alternatively, the auxiliary transmission lever 5 may be allowed to return to the neutral position 13A, and when the auxiliary transmission lever 5 is set to the neutral position 13A, the main transmission lever 4 may be forcibly returned to the neutral position.

Further, the parking brake 8 may be activated when the auxiliary transmission lever 5 is pushed or pulled at the neutral position 13A.

A brake lever that can be used only at the neutral position 13A of the auxiliary transmission lever 5 is provided instead of the control unit 7, and the work machine 10 can be driven by inserting the clutch 9 while the parking brake 8 is being applied to the traveling device 3. You may do it.

1 engine 2 continuously variable transmission 3 traveling device 4 main transmission means (main transmission lever)
5 Sub-transmission means (sub-transmission lever)
6 Neutral detection means (neutral sensor)
8 parking brake

Claims (3)

In a transmission of a work vehicle in which a traveling device (3) can be moved forward and backward by a continuously variable transmission (2),
A neutral detecting means (6) for detecting that the main transmission means (4) for switching the continuously variable transmission (2) to the forward and backward shifting is shifted to the neutral position is provided, and the neutral detecting means (6) is used to set the neutral position. A transmission for a work vehicle, characterized by activating a parking brake (8) when detected. Sub-transmission means (5) for switching the traveling speed between high and low is provided subsequent to the main transmission means (4), and when the parking brake (8) is operated, the sub-gear (5) is forcibly returned to neutral and no shifting is possible. The transmission for a work vehicle according to claim 1, wherein: 2. The transmission system for a work vehicle according to claim 1, wherein the main transmission means (4) can release the parking brake (8) only in a neutral position.

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