JPH07101264A - Work vehicle accelerator operation structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an accelerator operating structure of a work vehicle capable of maintaining an engine speed at a predetermined speed even when a load fluctuates during work traveling in a state where engine noise is low. [Structure] An actuator 21 that links a speed governing device 13 of an engine 5 and an artificial accelerator setting tool 10 and speed-controls the speed governing device 13 up to a predetermined rotation speed for work based on an operation command of a work device 4. In an accelerator operating structure of a work vehicle including the above, a rotation speed sensor 28 for detecting the rotation speed of the engine 5 is provided, and the rotation speed sensor 2
Control means 26 is provided for controlling the actuator 21 based on the detection result of No. 8 so that the engine speed during operation of the work device 4 is maintained at a predetermined working speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention links an engine speed control device and an artificial accelerator setting tool, and controls the speed control device to a predetermined rotational speed for work based on an operation command of a work device. The present invention relates to an accelerator operating structure for a work vehicle including an actuator that operates.

[0002]

2. Description of the Related Art Conventionally, in the accelerator operating structure of this type of work vehicle, for example, as shown in Japanese Patent Application No. 4-102726 previously filed by the applicant of the present invention, when operating the work device, The speed control device is operated in a constant speed control state so that the engine speed automatically corresponds to the work traveling.

[0003]

By the way, in a work vehicle, since the vehicle body travels while operating the work device,
The engine speed during work traveling is also set to a predetermined position near the maximum speed position. For this reason, engine noise is increased during work traveling, which causes an unpleasant feeling to the operator and lowers fuel consumption. Further, in the above-described conventional structure, the speed governor is simply operated so that the speed governor is maintained only in a predetermined speed governing state during work traveling, so that the engine speed fluctuates as the work load fluctuates. In this case, it is not possible to change and adjust the engine speed so as to maintain the operating speed of the work device at a constant value. Could not be corrected to the proper working condition. The present invention has been made in view of the above circumstances, and is for a work vehicle capable of maintaining the engine speed at a predetermined speed even when there is a change in load during work traveling in a state where engine noise is low. The purpose is to provide an accelerator operation structure.

[0004]

In order to achieve the above-mentioned object, an accelerator operating structure for a work vehicle according to the present invention is provided with a rotation speed sensor for detecting the rotation speed of the engine in the structure described above. A control means is provided for controlling the actuator based on a detection result of the rotation speed sensor so as to maintain the engine rotation speed at a predetermined rotation speed for work during operation of the work device. And The operation and effect of this characteristic configuration are as follows.

[0005]

That is, based on the detection result of the rotation speed sensor for detecting the rotation speed of the engine, the engine rotation speed during the operation of the work device is maintained at a predetermined rotation speed, that is, the engine rotation speed at which the work can be favorably performed. As described above, since the actuator for operating the speed governor can be controlled, even if the work load fluctuates and the engine speed fluctuates, the fluctuation can be corrected and the work device maintains a good operating state. You can do it.

[0006]

Therefore, the engine speed at the time of operating the work device is set in advance so as to allow the work device to work well, and the engine speed is adjusted so that engine noise does not occur much in that state. By setting the engine speed with good fuel consumption in advance, you can perform fuel-efficient work with less discomfort, and maintain a constant engine speed regardless of changes in the load on the work equipment. I was able to do such work.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 7 shows a riding type lawnmower work vehicle as an example of the work vehicle. This riding lawn mowing work vehicle is configured as a mid-mount type equipped with a mower 4 as a working device between front and rear wheels 2 and 3 of a riding traveling vehicle body 1, and an output of a vertical axis type engine 5 mounted on the rear portion of the vehicle body. A part of the belt transmission device 6, the hydrostatic continuously variable transmission 7 and the mission case 8
It is configured to be transmitted to the rear wheel 3 via the motor and a portion of the engine output to the mower 4 via the belt transmission device 9. The hydrostatic continuously variable transmission 7 which is a traveling transmission is capable of forward or backward continuously variable transmission by stepping forward or backward of a transmission pedal 10 as an artificial accelerator setting tool. The tension type PTO clutch 11 provided in the belt transmission 9 can be turned on and off by a PTO clutch lever 12 at the driver's hand.

Next, the operation structure of the speed control mechanism provided in the engine 5 will be described. As shown in FIGS. 1 to 3, the speed control lever 13 a of the speed control device 13 provided in the engine 5
Is biased to the minimum rotation position (idling position) MIN, and the wire 14 led out from the speed control lever 13a is
The first rotating member 15 in which the rotatably supported around the axis P.
Is attached to. The support shaft 16 for supporting the first rotating member 15 is provided on a sheet metal supporting case member 17 provided on the riding vehicle body 1. Then, the first rotating member 15 is provided with a step portion 17a formed on the support case member 17 with an engaging portion 15a which is engaged with the step portion 17a so as to be restricted at the lowest rotation position. On both sides of the first rotating member 15, a fourth rotating member 18 and a third rotating member 19 are respectively supported by a support shaft 16 so as to be rotatable around an axis P. An operation wire 20 led out from the speed change pedal 10 is attached to the fourth rotating member 18 while being urged by a neutral wire. An end portion of an operation wire 22 that is pushed and pulled by an electric servomotor 21 as an actuator is attached to the third rotation member 19. A second rotating member 23, which is adjacent to the third rotating member 19 at the opposite side to the first rotating member 15, is pivotally supported on the support shaft 16 about the axis P. Then, the second rotating member 23
Is configured to be held by friction by being pressed against the support case member 17 by a disc spring 24, and a hand accelerator lever 25 as an artificial accelerator setting tool is continuously provided. Further, the electric servomotor 21 is drive-controlled by a signal from a control device 26 as a control means.
Further, whether or not the PTO clutch lever 12 is in the clutch-engaged operation state is detected by a lever operation position detection sensor 27 including a limit switch that can detect the operation position of the lever 12, and the detection signal is input to the control device 26. I am trying to do it. Further, a signal from an engine speed sensor 28, which will be described later, is also input to the control device 26.

As shown in FIG. 1, on the opposite side of the first rotating member 15 with the engaging portion 15a sandwiching the support shaft 16, a pin 29 is provided on both left and right sides in parallel with the axis P. Is protruding. Then, the pin 29 is inserted into the long holes 23A, 19A, 18A formed in the second rotating member 23, the third rotating member 19, and the fourth rotating member 18, respectively. These elongated holes 23A, 19A, 18A are formed in an arc shape with the axis P as the center, and are flexible so as to accelerate the first rotating member 15 but allow the movement of the barb 29. The upper ends of the rotations of the elongated holes 23A, 19A, 18A to the speed-increasing girders are abutting parts 23a, 19a, 18a that abut the pin 29. The contact portion 23a of the elongated hole 23A of the second rotating member 23 is set by swinging the hand accelerator lever 25 when the PTO clutch lever 12 is in the off operation state and the speed change pedal 10 is in the neutral state. The pin 29 is pressed and moved to an arbitrary operation position, and the first rotating member 15 is rotationally operated to operate the speed control lever 13a in an arbitrary state to hold the frictional position by the disc spring 24. It will be. Further, when the PTO clutch lever 12 is turned on, the third rotation member 19 is rotated by the drive of the electric servomotor 21 in response to a signal from the control device 26, which is set by the hand accelerator lever 24 and set in the middle of the long hole 19A. The abutting portion 19a abuts and presses the positioned pin 29 to rotate the first rotating member 15 to a predetermined rotational position at which a preset working rotational speed is reached. On the other hand, in the contact portion 18a when the speed change pedal 10 is in the neutral state, the first rotation member 15 has the lowest rotation position MIN.
The pin 29 is brought into contact with the shift pedal 10 when the shift pedal 10 is in the position Although the speed control lever 13a is not operated with, the pin 29 is pressed by the abutment portion 18a when the abutment portion 18a abuts the pin 25 and then the speed-increasing gutter is operated. High-speed rotation will be operated from the speed-adjusting position set in. Then, when the speed change pedal 10 is operated at the highest speed, the speed control lever 3a is also operated to the maximum rotation position MAX.

The engine 5 is provided with an engine rotation speed sensor 28 for detecting the rotation speed of the engine 5, and a detection signal from the engine rotation speed sensor 28 is input to a control device 26 to Based on the detection signal, the rotation speed of the engine 5 during driving of the mower 4 is controlled to be maintained at a preset rotation speed. In order to preset the rotational speed of the engine 5, as shown in FIG. 4, a control panel 30 is provided in the control section of the passenger traveling vehicle body 1, and the operation panel 30 includes a control panel for the mower 4. A rotation speed setting dial 31 for setting the blade rotation speed (working rotation speed) is provided, and the engine rotation speed during work is artificially set in advance by the rotation speed setting dial 31. And the control device 2
In No. 6, even if the actual engine speed detected by the engine speed sensor 28 fluctuates around the predetermined engine speed set by the speed setting dial 31, the fluctuation is corrected. The signal for driving the electric servomotor 21 is output so that the engine speed becomes the predetermined value, and the speed governor 13 is operated by the electric servomotor 21.

Next, the switches and the like provided on the operation panel 30 will be described. In addition to the rotation speed setting dial 31, the operation panel 30 is provided with a mode switch 32 for mode selection and a manual switch 33. The mode switch 32 is a neutral return type two-point operation switch, and when the switch is operated upward, the control mode in the control device 26 becomes the automatic control mode, and the mode is controlled automatically in the automatic control mode state, and the switch is operated downward. Then, the control unit 26 enters a rotation speed setting mode in which the engine rotation speed (working rotation speed) set by the rotation speed setting dial 31 is read and the engine rotation speed at the time of work is set as the set engine rotation speed. In addition, after setting the rotation speed setting mode, the operation is once switched on to the automatic control mode. When the control mode of the control device 26 is the automatic control mode, the mode selection switch 32
The monitor lamp 34 disposed above the lamp is turned on, and the monitor lamp 34 is turned off when not in the automatic control mode. The manual switch 33 is for finely adjusting the engine speed (working speed). When the switch is operated upward, the engine speed gradually increases while the switch is operated, and the switch downward. When operated, the controller 26 adjusts the engine speed so that the engine speed gradually decreases while the switch is operated. That is, the manual switch 33 is used when the operator himself appropriately sets an appropriate engine speed during work.
It will be decided by the operation of. Incidentally, FIG. 6 shows a flow of control based on the operation of the switch or the like as a flowchart.

Further, as shown in FIGS. 5 and 7, an automatic control mode for automatically maintaining the cutting height of the mower 4 at a preset cutting height is provided beside the steering handle 35 of the control section. , A cutting height setting mode in which the cutting height in this automatic control mode is set to a value set by the cutting height setting dial 36, an up mode in which the mower 4 is manually operated to raise, and a mower 4 in manual operation. There is provided a mower operating lever 37 that can be operated in a cross mode in a down mode for lowering the lever and that automatically returns to the neutral position when not operated.
The mower operating lever 37 is swung forward in the up mode, swung backward in the down mode, and swung upward when the automatic control mode is set. When the height set mode is set, the swing operation is performed downward. The control corresponding to each mode of the mower operating lever 37 is the same as the control in each mode of the engine speed described above, and the automatic control mode and the cutting height setting mode are temporarily operated and the mode state is maintained thereafter. In addition, in the up mode and the down mode, the mower 4 is moved up and down while the mode operation is continued. In the figure, reference numeral 38 denotes a monitor lamp which is turned on in the automatic control mode and turned off in the non-automatic control mode. Further, when adjusting the correspondence between the cutting height sensor (not shown) and the mower 4, P
This can be done even with the TO clutch 11 turned off so that the cutting height set is not affected by the adjustment.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an accelerator operation structure.

FIG. 2 is a perspective view showing an external appearance of a linkage mechanism that relays accelerator operation and the like.

FIG. 3 is an exploded vertical cross-sectional side view showing an internal structure of a linkage mechanism that relays accelerator operation and the like.

FIG. 4 is a front view showing an operation panel.

FIG. 5 is a side view showing an operating lever or the like for adjusting the cutting height, which is provided on the side of the steering handle.

FIG. 6 is a flowchart showing an outline of a control flow.

FIG. 7 is an overall side view showing a riding lawn mower as an example of a work vehicle.

[Explanation of symbols]

 4 Working Device 5 Engine 13 Speed Control Device 21 Actuator 26 Control Means 28 Revolution Sensor

Claims (1)

[Claims] 1. A speed control device (1) for an engine (5) is linked to a manual accelerator setting tool (10), and the speed control device (1) is operated based on an operation command of a working device (4).
In an accelerator operating structure of a work vehicle including an actuator (21) for speed-controlling 3) up to a predetermined rotational speed for work, a rotational speed sensor (28) for detecting the rotational speed of the engine (5) is provided, and This rotation speed sensor (28)
A control means (26) for controlling the actuator (21) so as to maintain the engine rotation speed at a predetermined rotation speed for work based on the detection result of (1). Work vehicle accelerator operation structure.