JP2007030777A - Deceleration pedal device of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deceleration pedal device of a working vehicle capable of two operations in a conventional system in one operation of stepping in a deceleration pedal (7). <P>SOLUTION: A front wheel steering mechanism (4) and a four-wheel steering mechanism (5) are equipped on a working vehicle (3) to transmit drive wheels (2) by a static hydraulic continuously variable transmission (1) in a steerable manner. The static hydraulic continuously variable transmission (1) is speed-change operable by the deceleration pedal (7) provided at a steerable position from a steering seat (6), and the deceleration pedal (7) is capable of performing the changing operation from the front wheel steering mechanism (4) to the four-wheel steering mechanism (5) together with the decelerating operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deceleration pedal device for a work vehicle that transmits wheels with a continuously variable transmission such as HST.

  Conventionally, this type of work vehicle is equipped with a front wheel steering mechanism, a rear wheel steering mechanism, and a four-wheel steering mechanism that allows these two steering mechanisms to function simultaneously. Depending on the type (work content), etc., any one of the steering mechanisms is selected, and the vehicle is quickly and safely steered.

On the other hand, the hydrostatic continuously variable transmission is characterized by its ability to change the vehicle's running speed steplessly and easily switch between forward and reverse by switching between forward and reverse rotation, and is widely used for this type of work vehicle. Has been. For example, Japanese Patent Application Laid-Open No. 9-13428 discloses a technique in which a hydrostatic continuously variable transmission is mounted and equipped with a deceleration pedal that performs a deceleration operation.
Japanese Patent Laid-Open No. 9-13428

  When a conventional tractor equipped with a hydrostatic continuously variable transmission is equipped with a front wheel steering mechanism, a rear wheel steering mechanism, and a four-wheel steering mechanism that causes both steering mechanisms to act simultaneously, and travels and turns, The shifting operation and the switching operation of the steering mechanism are configured to be performed individually, and there is a problem that the operator is burdened with a troublesome operation.

  A conventional tractor referred to as a passenger management machine is configured to perform switching between a reduction pedal of a hydrostatic continuously variable transmission (see Patent Document 1 presented by the applicant) and each steering mechanism by a button operation, Even between the traveling speed and the steering mechanism that is extremely related, a separate switching operation is required.

  The invention described in claim 1 of the present application is directed to a work vehicle (3) that transmits drive wheels (2) by means of a continuously variable transmission (1), a front wheel steering mechanism (4), a four-wheel steering mechanism (5), The continuously variable transmission (1) is provided with a speed reduction pedal (7) provided at a position operable from the control seat (6) of the work vehicle (3). ), The speed reduction pedal (7) can be operated by shifting the front output steering mechanism (4) from the front wheel steering mechanism (4) together with the deceleration operation of the continuously variable transmission (1). A reduction pedal device for a work vehicle configured to be switched to a steering mechanism (5), wherein a deceleration operation and a switching operation of a steering mechanism can be performed by a single stepping operation of the deceleration pedal (7). is there.

Therefore, according to the present invention, the troublesomeness of separately performing the two conventional operations can be simultaneously performed by a single depressing operation of the deceleration pedal (7).
In particular, when the work vehicle (3) is decelerated by stepping on the deceleration pedal (7) during work, the work vehicle (3) is switched to four-wheel steering, which is frequently used during low-speed traveling, so that the operational burden on the operator can be reduced, The work can be done easily in a narrow field with limited turning places while continuing low-speed running.

  Next, in the invention described in claim 2, when the speed reduction pedal (7) decelerates the continuously variable transmission (1) by a depressing operation, the speed reduction ratio at the initial depressing step is lowered during traveling at a working speed. The speed reduction pedal device for a work vehicle according to claim 1, wherein the speed reduction device is configured to reduce the speed reduction ratio at the end of the stepping down while traveling at a travel speed. It is possible to adjust the vehicle speed slowly, and during traveling on the road, it is effective to increase the traveling safety to reduce the deceleration ratio at the end of the stepping-down in order to avoid a sudden stop.

  First of all, the invention described in claim 1 has a configuration in which two operations that have been conventionally performed individually can be performed by a single operation of depressing the deceleration pedal (7), thereby greatly reducing the operation burden on the operator. There are features.

  In the present invention, when the vehicle is decelerated by depressing the deceleration pedal (7), the four-wheel steering mechanism is switched to a frequently used four-wheel steering mechanism at the same time. It has the feature that it can turn with a small turn.

  In the invention described in claim 2, during the work (running at the work speed), the deceleration ratio at the initial step of the deceleration pedal (7) is lowered, so that the vehicle speed can be adjusted slowly in the high speed range. , It has the feature that the field work can be performed efficiently.

  Also, while driving on the road, by reducing the deceleration ratio at the end of the depression of the deceleration pedal (7), it is possible to avoid a sudden stop and prevent the body from turning in front of the vehicle just before stopping, so that it can be stopped in a natural state. There is a feature that can ensure the safety of traveling.

  The invention of the present application includes a front wheel steering mechanism 4, a rear wheel steering mechanism 16, and a four-wheel steering mechanism 5 that can simultaneously steer both the work vehicle 3 that transmits the drive wheels 2 by the hydrostatic continuously variable transmission 1. It is configured to be switched to any one and steer. The hydrostatic continuously variable transmission 1 is configured such that a traveling output can be shifted by a speed reduction pedal 7 provided at a position operable from the control seat 6 of the work vehicle 3. The decelerating pedal 7 can be switched from the front wheel steering mechanism 4 to the four-wheel steering mechanism 5 together with the decelerating operation of the hydrostatic continuously variable transmission 1 by depressing the pedal.

  Therefore, the present invention can perform two operations that were conventionally performed by depressing the deceleration pedal, so that the operation burden on the operator is greatly reduced and the operation is performed at a low speed. By switching to the high-speed four-wheel steering mechanism 5, the work efficiency can be improved while improving the work efficiency.

Hereinafter, the present invention will be specifically described with reference to the drawings.
As shown in FIGS. 2 and 3, the passenger management machine 3 corresponds to the work vehicle 3 of the present application, and is provided with a steering seat 6 disposed on a body frame 10 and a steering handle 11 provided at a front position thereof. It is configured to be steerable. The passenger management machine 3 is electrically connected to the front wheel steering mechanism 4 and the 4WS changeover switch 14 that are electrically connected to the FWS changeover switch 13 disposed on the operation panel 12 of FIG. A four-wheel steering mechanism (both the front wheel steering mechanism 4 and the rear wheel steering mechanism 16) 5 and a rear wheel steering mechanism 16 electrically connected to the RWS changeover switch 15 are provided. When each of the steering mechanisms 4, 5, and 16 is selected and operated by switching one of the changeover switches 13, 14, and 15, the corresponding steering mechanism becomes operable, and the steering handle is operated. It is configured to be able to turn.

  As shown in FIG. 2, the passenger management machine 3 is provided with a pair of left and right front wheels 19 and 19 and a pair of left and right rear wheels 20 and 20 on the front and rear portions of the vehicle body frame 10 for four-wheel drive. The front wheels 19 and 19 are configured such that the left and right wheels 19 and 19 are coupled to each other in the same direction by the interlocking rod 21, and the steering force is transmitted by the steering rod 22 connected to the power steering mechanism. The rear wheels 20 and 20 are coupled to each other so that the left and right wheels can be interlocked with an interlocking rod 23, and the steering force is transmitted with a steering rod 24 connected to a power steering mechanism on the rear wheel side. .

  The two steering rods 22 and 24 are connected to the steering handle 11 via the steering mechanism and the power steering mechanism, respectively, and transmit the steering force to the individually connected wheels. The steering rod 22 on the front wheels 19 and 19 side transmits a steering force based on the turning angle of the handle 11 to the front wheels when the front wheel steering or the four-wheel steering is selected and the changeover switch 13 or 14 is turned on. It is configured. The rear wheel side steering rod 24 is configured to transmit the steering force of the handle 11 to the rear wheel when the rear wheel steering or the four wheel steering is selected and the changeover switch 14 or 15 is turned on.

  As shown in FIG. 2 and FIG. 3, the engine 27 is mounted in an engine room covered with a bonnet cover 28 disposed in front of the steering handle 11, and rotational power is supplied to the lower hydrostatic continuously variable transmission 1 below. It is configured to transmit to the traveling mission device 29 via (HST).

  As shown in FIG. 4, the hydrostatic continuously variable transmission 1 is configured to receive rotational power from the output shaft 30 of the engine 27 described above via the main clutch 31. The hydrostatic continuously variable transmission 1 is composed of a hydraulic pump and a hydraulic motor as is well known in the art, and the rotational power is input to the hydraulic pump side to drive the pump and pump the operation. In the process in which oil is sent to the motor side and circulated, forward / reverse switching and speed increasing / decreasing are performed and output from the hydraulic motor to the traveling mission device 29.

  In this case, the hydrostatic continuously variable transmission 1 is controlled by the swash plate whose inclination angle is adjusted by the trunnion shaft 32 operated from the outside of the machine. The rotational power thus output is output to the traveling mission device 29 side.

  As shown in FIG. 5, the electric cylinder 33 is connected to the controller 34 and is electromagnetically operated to expand and contract based on a control signal output from the controller 34, and the tip of the piston 35 is connected to the trunnion arm 36. It is configured to be connected to the trunnion shaft 32 via a rotation operation. The deceleration pedal 7 is configured such that the depression amount detected by the position sensor 37 provided on the base side is input to the controller 34 as detection information.

  Further, the controller 34 outputs a control signal to the electric cylinder 33 in accordance with the depression amount of the deceleration pedal 7 input from the position sensor 37, and rotates the trunnion shaft 32 via the trunnion arm 36. Yes.

  The electric cylinder 33 is provided with a position sensor for detecting the movement position of the piston 35. As shown in FIG. 1, the speed reduction pedal 7 is provided with a limit switch 38 at a position where it can be switched ON and OFF by a stepping operation. From the limit switch 38 to the FWS switch 13 and the 4WS switch 14. Connected to send a switching signal.

  As described above, when the deceleration pedal 7 is depressed to operate the hydrostatic continuously variable transmission 1 to the deceleration side, the 4WS changeover switch 14 can be turned on simultaneously and the FWS changeover switch 13 can be turned off. It has become. Accordingly, the riding management machine 3 continues to decelerate while the depressing pedal 7 is depressed, and at the same time, a four-wheel steering mechanism (a state in which both the front wheel steering mechanism 4 and the rear wheel steering mechanism 16 work) 5. Is always steerable.

In the riding management machine 3, when the foot is released from the deceleration pedal 7, the speed is returned to the speed before the stepping on, and the steering mechanism is activated by returning to the front wheel steering mechanism 4.
Further, as shown in FIG. 4, the traveling mission device 29 is capable of switching between a main transmission device 40 capable of four-stage shifting and two stages of high speed (traveling speed) and low speed (working speed). The sub-transmission device 41 is built in.

  When the controller 34 decelerates the hydrostatic continuously variable transmission 1 by depressing the decelerating pedal 7, the controller 34 reduces the initial depressing ratio and decreases the traveling speed ( During traveling in B), the vehicle is decelerated while reducing the deceleration ratio at the end of the step. As shown in the graph of FIG. 6, the deceleration ratio in this case is reduced at a work speed (in the case of traveling with the auxiliary transmission 41 switched to a low speed) (A) by gradually reducing the initial deceleration change rate at the start of stepping. In the traveling speed (when traveling with the auxiliary transmission 41 at a high speed) (B), the vehicle is configured to decelerate with a moderate deceleration change rate in the range immediately before the stepping.

  If comprised as mentioned above, the riding management machine 3 will be able to adjust a vehicle speed in the speed range of the fast side with a high frequency of use within the range of work speed (A) during work. There is a special feature. The passenger management machine 3 can adjust the vehicle speed in a limited range immediately before the position where the decelerating pedal 7 is depressed (immediately before stopping) while traveling on the road at the traveling speed (A). There is a feature that can be avoided and ensure safety during high-speed driving.

  The above configuration can be expected to have the same operation and effect even when the speed reduction pedal 7 is replaced with a speed change lever. That is, a position sensor that can detect the shift position is provided on both the shift lever and the trunnion shaft 32, and sensors that detect the work speed and the traveling speed are further arranged and connected to the controller 34.

Then, the controller 34 is configured to take the same shift pattern as the work speed (A) and the travel speed (B) of FIG. 6 based on the operation of the shift lever.
As described above, when the speed change lever is replaced with the deceleration pedal 7, the riding management machine 3 has a feature that the front speed of the vehicle body is reduced because the speed reduction ratio immediately before the stop is low at the traveling speed (B), and the working speed ( Even in A), the same operation and effect as the deceleration pedal 7 can be expected.

Next, an embodiment in which the neutral position of the transmission lever of the hydrostatic continuously variable transmission 1 can be reliably maintained will be described.
In general, it is known that this type of hydrostatic continuously variable transmission 1 is extremely difficult to accurately hold the shift lever at the neutral position, and after a while in the state of being operated and held at the neutral position, In many cases, passenger management machines move naturally. This is because the operating lever is held away from the neutral position, but in reality, it is difficult to accurately operate and hold the operating lever at the neutral position.

  Therefore, in this embodiment, as shown in FIG. 7, the speed reduction pedal 7 and the unload valve operation unit 45 of the hydrostatic continuously variable transmission 1 are connected to each other by an operation wire 46 so as to be interlocked and operable. Yes. Therefore, in this embodiment, when the deceleration pedal 7 is depressed to the maximum, it is operated via the operation wire 46, and the unload valve operating unit 45 forcibly pushes the valve and becomes the same as the clutch is disengaged.

  In this way, when the hydrostatic continuously variable transmission 1 is operated to the neutral position to stop the output, the unload valve is forcibly related when the operation lever is operated to the neutral position as in the prior art. The output is stopped by pushing in to stop the circulation of hydraulic oil. Therefore, since the hydrostatic continuously variable transmission 1 is forced to be neutral when operated to the neutral position, the riding management machine has moved from its original position after a while after the operation lever is neutral. The danger is eliminated.

  Next, in the case where the passenger management machine is a control work vehicle, when a spraying error occurs, the hydrostatic continuously variable transmission 1 is automatically decelerated and the vehicle speed is slowed down so that the range of abnormal spraying can be reduced as much as possible. A description will be given of an embodiment in which the operator narrows down and immediately warns the operator that the spray is abnormal.

  First, as shown in FIG. 8, the controller 48 is configured to connect a flow rate sensor provided in the piping path of the sprayed chemical solution to the input side and to input it when the flow rate sensor detects an abnormality. The controller 48 is configured to be connected so that a control signal is output to the solenoid valve 50 that switches the oil passage of the hydraulic oil to be sent to the operation cylinder 49 so that the switching operation can be performed. In the hydrostatic continuously variable transmission 1, the trunnion shaft 52 is operated from the operation cylinder 49 via the trunnion lever 51 to the deceleration side.

The alarm display lamp 53 is provided on the operation panel 54 of the vehicle body and blinks in response to a control signal from the controller 48.
As described above, in the control work vehicle, when a spray error is detected by the flow rate sensor and is input to the controller 48 during the work, the hydrostatic continuously variable transmission 1 is decelerated and the vehicle speed is automatically increased. The alarm display lamp 53 on the operation panel 54 blinks and the operator can be warned of an abnormality. In this way, when the spraying error occurs and the spraying amount decreases rapidly, the control work machine immediately detects the flow rate sensor and inputs the detection information to the controller 48 to set the hydrostatic continuously variable transmission 1. Decelerate to significantly reduce vehicle speed. Therefore, the control work vehicle has an advantage that the distance traveled with the spray error becomes short and the range through which the error passes is narrowed, and the actual damage is reduced until the operator notices and stops.

The side view of the speed-reduction pedal electrically connected with the operation panel. The top view of a passenger management machine. The side view of a passenger management machine. The side view of a hydrostatic continuously variable transmission and a transmission mechanism. FIG. 3 is a route diagram in which an operating force is transmitted from a deceleration pedal to a hydrostatic continuously variable transmission. The graph which shows the deceleration curve of working speed and traveling speed. The side view which connected the deceleration pedal and the hydrostatic continuously variable transmission so that operation was possible. Exploded view for explaining the embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrostatic continuously variable transmission 2 Drive wheel 3 Riding management machine 4 Front wheel steering mechanism 5 Four wheel steering mechanism 6 Steering seat 7 Deceleration pedal

Claims (2)

The work vehicle (3) that transmits the drive wheels (2) by the continuously variable transmission (1) is equipped with a front wheel steering mechanism (4) and a four-wheel steering mechanism (5), and can be switched to either one for steering. The continuously variable transmission (1) is configured such that a traveling output can be changed by a deceleration pedal (7) provided at a position operable from a control seat (6) of the work vehicle (3), The decelerating pedal (7) is configured to switch from the front wheel steering mechanism (4) to the four-wheel steering mechanism (5) together with the decelerating operation of the continuously variable transmission (1) by depressing the depressing pedal. A deceleration pedal device for a vehicle. When decelerating the continuously variable transmission (1) by depressing operation, the decelerating pedal (7) reduces the initial depressing ratio while traveling at the working speed (A) and travels at the traveling speed (B). 2. The deceleration pedal device for a work vehicle according to claim 1, wherein the deceleration pedal device is configured to decelerate while reducing the deceleration ratio at the end of the step.

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