JP2000314327A - Governor device for farm tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a governor characteristic which is suitable for plowing-down work and plowing-up work by changing first and second governor characteristics on the basis of an acceleration set value which is set by an acceleration regulator, and controlling a fuel supplying quantity regulating mechanism, while selectively using the first and second governor characteristics. SOLUTION: In the base where an automatic position and a switching-off position are selected by a work mode selecting switch 16, a first governor characteristic Gb, which is suitable for plowing-down work, is selected. When a draft position is selected, a second governor characteristic Gc which is suitable for traction work is selected. When high speed movement by lifting up a work device, namely, that it is decided as road traveling, a third governor characteristic Ga for traveling on a road is selected regardless of a selecting condition of a work mode selecting mode 16. A control rack 31 is drivingly controlled by a solenoid 33 according to the selected first and second governor characteristics Gb, Gc, and a fuel supplying quantity is regulated so as to obtain engine rotation which is suitable for plowing-down work and plowing-up work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a governor device for an engine mounted on an agricultural tractor.

[0002]

2. Description of the Related Art As a governor device for an engine mounted on an agricultural tractor, an all-speed governor capable of regulating a speed in an entire engine rotation range from an idling rotation to a maximum rotation is used. The all-speed governor suppresses fluctuations in engine speed by increasing or decreasing engine torque according to fluctuations in engine load, and can stabilize work traveling speed and operating speed of work equipment regardless of engine load. It has characteristics and is used as a thing suitable for not only agricultural tractors but also many other agricultural working machines and earth moving machines.

[0003]

The most important tillage work performed using the agricultural tractor includes a tillage work using a rotary tillage device and a tillage work using a plow device. In this case, since the work forms of the tilling operation and the tilling operation are greatly different from each other, if the tilling operation and the tilling operation are handled by a governor device having one kind of governor characteristic, the response is insufficient. turn into.

For example, in tilling work, it is desirable to drive a rotary tilling device at a stable rotation speed in order to perform uniform crushed soil tilling. For this purpose, a torque curve having a large torque variation rate with respect to a change in engine speed is set. It is necessary that the governor characteristics be used. On the other hand, in plowing work, when the work load (traction load) increases, it is desirable to exert sufficient propulsive force without stopping the engine even if the engine speed slightly decreases. It is required that the governor characteristics be set to a sticky torque curve in a high load region.

[0005] As described above, there is a difference in desirable governor characteristics between the tilling operation and the plowing operation. If the tilling operation is mainly considered when a single governor characteristic is set, the operation is always performed with the preferable characteristics during the tilling operation. When the tilling work is mainly considered, on the other hand, it is not always possible to work with suitable characteristics during the tilling work. SUMMARY OF THE INVENTION It is an object of the present invention to provide a governor device for an agricultural tractor in which a tilling operation and a plowing operation can be performed based on desirable governor characteristics.

[0006]

Means for Solving the Problems [Structure of Claim 1] The structure of Claim 1 is to configure the governor device of the agricultural tractor as follows. Automatic tillage depth control mode, in which a rotary tillage device that is connected to the tractor can be raised and lowered automatically based on the detection result of the tillage depth detection means, and a tow-type working device that is connected to the tractor can be moved up and down tow load. A draft control mode for automatically moving up and down based on the detection result of the detection means, a work mode selection means for selecting an automatic plowing depth control mode or a draft control mode, and electricity for operating a fuel supply amount adjustment mechanism of an engine mounted on the tractor main unit. An actuator and an accelerator adjuster that is set artificially by setting the accelerator set value of the engine, and is set for the automatic cultivation depth control mode, and is set to the accelerator set value set by the accelerator adjuster. A first governor characteristic whose characteristics are changed based on the first governor characteristics and a draft control mode, which are set by an accelerator adjuster. And a second governor characteristic whose characteristic is changed based on the accelerator setting value to be selected, the first or second governor characteristic is configured to be selectable, and based on the selected first or second governor characteristic, The fuel supply amount adjusting mechanism is operated by an actuator.

According to the configuration of the first aspect, the first and second governor characteristics suitable for the tilling operation and the tilling operation can be set, respectively. In tilling work, it was possible to perform good crushed soil tilling with a stable rotation speed, and in tilling work, it became possible to perform good traction running by exerting a sufficient propulsive force.

According to the first aspect of the present invention, there is provided an accelerator adjusting device which is used to set an accelerator setting value of the engine and is manually operated, and based on the accelerator setting value set by the accelerator adjusting device, The characteristic of the first governor characteristic is changed, and the characteristic of the second governor characteristic is changed based on the accelerator setting value set by the accelerator adjuster.

According to a second aspect of the present invention, in the configuration of the first aspect, the first governor characteristic is such that the maximum torque point is on the high-speed side, and the accelerator setting is set by an accelerator adjuster. As the value is lower, the maximum torque point is shifted to the lower speed side, and the second governor characteristic is
The maximum torque point is shifted to the lower speed side, and the maximum torque point is shifted to the lower speed side as the accelerator setting value set by the accelerator adjuster is lower.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS.
Diesel engine 2 mounted on tractor unit 1
Is transmitted to the rear transmission case 4 via the main clutch 3, and the transmission power is branched into the traveling system and the PTO system in the transmission case 4. In the traveling system, power is shifted by the traveling transmission mechanism 5 and transmitted to the front wheels 6 and the rear wheels 7,
In the PTO system, power is transmitted via a PTO transmission mechanism 8 and a PTO clutch 9 to a rear PTO shaft 10 as work power at a desired rotational speed.

As shown in FIG. 1 and FIG.
A lift arm 12 driven by a hydraulic cylinder 11 and a three-point link mechanism 13 driven to move up and down by the lift arm 12 are provided at the rear part. At the rear of the three-point link mechanism 13, various drive-type working devices including a rotary tillage device 14 (see FIG. 1), tow-type working devices including a plow device 15 (see FIG. 2), and other various types The non-drive type working device is configured to be connectable, and the drive type working device such as the rotary tilling device 14 is configured to be driven by the power of the PTO shaft 10.

The work device connected to the three-point link mechanism 13 is a work mode selection switch 16 (see FIG.
(See Reference), the elevator is driven up and down in one of the automatic plowing depth control mode, the draft control mode, and the position control mode. Next, the automatic plowing depth control mode, the draft control mode, and the position control mode will be described.

[Automatic tillage depth control mode] When the "auto" position is selected by the work mode selection switch 16, the automatic tillage depth control mode is set. The automatic tillage depth control mode is mainly used during tillage work using the rotary tillage device 14, and the rotary tillage device 14 is automatically raised and lowered so that the tillage depth d is maintained constant.

As shown in FIG. 1, the rotary tilling device 14
In addition, a rotary cover 17 that swings up and down in contact with a field scene and a cover sensor 18 that detects an angle of the rotary cover 17 are provided. As shown in FIG. The tillage depth adjuster 19 is provided. As shown in FIG. 8, the target tillage depth d ₀ set by the tillage depth adjuster 19 (target angle of the rotary cover 17)
And the tillage depth d (the actual angle of the rotary cover 17) detected by the cover sensor 18 are compared and calculated by the control device 20 using a microcomputer, and the operation angle (control amount) of the lift arm 12 is determined. Is done.

[0015] As shown in FIG.
The change in the engine load is detected based on the engine speed n detected in step 7, and the operation angle (control amount) of the lift arm 12 is finally determined based on the fuzzy inference or the like based on the change in the engine load, and the determined lift arm A control signal corresponding to the operation angle (control amount) of the lift arm 12 is output to the electromagnetic proportional control valve 21 to operate the hydraulic cylinder 11 for driving the lift arm 12. The operation angle (control amount) of the lift arm 12 is detected by a lift arm sensor 26 provided at the base of the lift arm 12.

[Draft control mode] When the "draft" position is selected by the work mode selection switch 16, the draft control mode is set. The draft control mode is used during plowing work using the plow device 15, and the plow device 15 is automatically moved up and down so that the traction load r is maintained constant.

As shown in FIG. 2, at the base end of the lower link 13a of the three-point link mechanism 13, a draft sensor 22 for detecting the traction load r acting on the fulcrum of the lower link 13a using a differential transformer or a strain gauge. As shown in FIG. 8, a draft setting device 23 for arbitrarily adjusting and setting the traction load r is provided in the control section. As shown in FIG. 8, the target traction load r ₀ set by the draft setting device 23 and the traction load r detected by the draft sensor 22 are input to the control device 20 and are compared and calculated. The electromagnetic proportional control valve 21 is operated based on the fluctuation of the traction load r so that the target traction load r ₀ is maintained.

[Position control mode] When the "OFF" position is selected by the work mode selection switch 16, the position control mode is set. In the position control mode, the working device can be moved up and down and held at a position corresponding to the operation position of the position lever 24 (see FIGS. 1 and 2) provided on the control unit. As shown in FIG. 8, the operation position of the position lever 24 is detected by a position setting device 25 provided at the base of the position lever 24, and the lift arm angle p detected by the lift arm sensor 26 is detected by the position setting device 25. to match the target lift arm angle p ₀ which is set, the electromagnetic proportional solenoid valve 21 is operated.

As shown in FIG. 4, a control rack 31 which is a fuel supply amount adjusting mechanism of a fuel injection pump 30 mounted on the engine 2 is configured to be operated by an electronic governor 32. The control rack 31 is a solenoid 3 displaced with a stroke proportional to the exciting current.
3 and the position of the control rack 31 is detected by a stroke sensor 34 using a differential transformer or the like. The engine rotation speed n is detected by a coil-type engine rotation sensor 37 facing a gear 36 fixed to a driving cam shaft 35 of the fuel injection pump 30, and the detected value of the engine rotation sensor 37 and artificially The position of the control rack 31 is controlled based on the set accelerator setting value.

The electronic governor 32 shown in FIG.
Controlled via 0. As shown in FIGS. 1, 2, and 8, a hand accelerator lever 38 that can be frictionally held at an arbitrary operation position in an entire range from an idling position to a maximum speed position as an artificially operated accelerator adjusting tool. , And a foot accelerator pedal 39 which automatically returns to the idling position side, and outputs an operation position to the hand accelerator lever 38 and the foot accelerator pedal 39 as an analog signal.
And an accelerator pedal sensor 41.

In the electronic governor 32 shown in FIG. 4, roughly two types of governor characteristics are stored and set in the control device 20 in advance. One of them is a third governor characteristic Ga set to a torque curve having a relatively small torque variation rate with respect to a variation in the engine speed n, as shown in FIG. 5, which is suitable for road running. . The other is Fig. 6 (a) (b)
As shown in FIG. 3, the first and second torque curves set to have a large torque variation rate with respect to the variation of the engine speed n.
The governor characteristics Gb and Gc are suitable for work traveling.

As shown in FIG. 6 (a), a torque curve having a particularly large torque variation rate with respect to a change in the engine speed n, in other words, a torque having a small change in the engine speed n with respect to a change in the engine load. The first governor characteristic Gb suitable for the tilling work set on the curve is set. FIG.
As shown in (b), the torque fluctuation rate is not as large as the first governor characteristic Gb with respect to the fluctuation of the engine speed n.
The second torque suitable for traction work in which the maximum torque point is deviated to the low-speed side and a sticky torque curve is set in a high load region.
The governor characteristic Gc is set.

In this case, as shown in FIGS. 9A and 9B, the first and second governor characteristics Gb and Gc are set such that the maximum torque point decreases as the accelerator set by the hand accelerator lever 38 rotates at a lower speed. It is preferable to set the torque curve to be deviated to have a more sticky characteristic in a high load region.

As shown in FIG. 7, the first, second, and third governor characteristics Gb, Gc, and Ga are configured to be automatically selected according to selection by the work mode selection switch 16 and predetermined conditions. . Basically, when the "auto" position and the "cut" position are selected by the work mode selection switch 16, the first governor characteristic Gb suitable for tilling work is selected, and the "draft" position is set by the work mode selection switch 16. Is selected, the second governor characteristic Gc suitable for towing work is selected. However, regardless of the selection state of the work mode selection switch 16, the third governor for road running is automatically set under the following conditions. The governor characteristic Ga is selected.

A traveling speed sensor 27 (which detects a traveling speed v of the tractor 1) is provided on a rotating shaft (not shown) (for example, an input bevel pinion shaft of a rear wheel differential mechanism) on which a final shift of the traveling system has been performed. 3 and 8) are provided.
The reference angle P set in advance to a value (for example, in the vicinity of the upper limit position) in which the lift arm angle p (work device height) detected by the lift arm sensor 26 is sufficiently higher than the angle at the time of normal use work. When it is detected that the detected traveling speed v is equal to or higher than the preset set speed V (steps # 3 and # 6), the working device is lifted at a high speed, that is, traveling on the road. Is determined, and the third governor characteristic Ga for road running is automatically selected regardless of the selection state of the work mode selection switch 16 (step # 8).

The set speed V is controlled by the work mode selection switch 16
When the "auto" position and the "off" position are selected by the work mode selection switch 16, the set speed V is set to, for example, 6 km / h. Select switch 16
When the "draft" position is selected by the operator, the set speed V is set to, for example, 10 km / h (step #)
2, # 6).

When the first, second, and third governor characteristics Gb, Gc, and Ga are set as described above, the following control is performed. On the road using the third governor characteristic Ga,
The torque curve of the third governor characteristic Ga is stored and set in advance as map data as a relationship between the engine speed n and the position (torque) of the control rack 31 for each accelerator setting value, and is obtained from the accelerator pedal sensor 41. The target position of the control rack 31 with respect to the detected engine speed n is calculated based on the map data corresponding to the accelerator setting value, and the detected position of the control rack 31 is brought closer to the target position of the control rack 31. Then, the solenoid 33 is controlled.

In the automatic plowing depth control mode and the draft control mode using the first and second governor characteristics Gb and Gc, the predetermined torque curve is determined by the engine speed n and the position (torque) of the control rack 31 for each accelerator setting value. The target position of the control rack 31 is determined based on the detected fluctuation of the engine speed n, and the detected position of the control rack 31 is stored in the control rack. The solenoid 33 is controlled so as to approach the target position 31.

[Another Embodiment of the Invention] As means for selecting the first governor characteristic Gb, a PTO
A PTO clutch sensor 28 (see FIGS. 3 and 8) for detecting the on / off state of the clutch 9 is provided, and when the “clutch engagement” of the PTO clutch 9 is detected, the traveling speed v detected by the traveling speed sensor 27 changes the set speed V ( For example, 5k
m / h) or less, the first governor characteristic Gb suitable for the tilling operation is automatically selected by judging that the cultivating operation is the tilling operation.

The automatic tillage depth control mode includes a tillage depth adjuster 19, a cover sensor 18, and an engine rotation sensor 3.
In addition to the mode in which the rotary tillage device 14 is automatically raised and lowered based on the detected value of 7, the present invention can be implemented in the following mode. The target tillage depth d ₀ (target lift arm angle p) is set by the tillage depth adjuster 19 and the lift arm sensor 2
6 detects the tilling depth d (the actual lift arm angle p) by, determining the operating angle of the lift arm 12 is compared with the set target tilling depth d ₀ and Kofuka d (control amount). In parallel with this, a change in the engine load (engine speed n) is detected by the engine rotation sensor 37, and the lift arm 12
Is finally determined. A signal corresponding to the determined operating angle (control amount) of the lift arm 12 is output to the electromagnetic proportional control valve 21 to operate the lift arm 12. In this embodiment, the rotary tilling apparatus 14 can be automatically moved up and down while the rotary cover 17 is lifted, and roughing work, inner cultivation tillage, ridge work, and the like are performed at a constant cultivation depth d in a wet or semi-wet field. be able to.

In the above embodiment, the governor characteristics in the position control mode are shared with the first governor characteristics Gb in the automatic plowing depth control mode, but are different from the first and second governor characteristics Gb and Gc. The governor characteristics may be stored and set, and the governor characteristics may be selected.

As the electric actuator 33 for operating the fuel supply amount adjusting mechanism 31, various DC servo motors can be used.

In the invention according to the first aspect, the present invention may be implemented in such a form that a dedicated switch for selecting a governor characteristic is provided, and the driver performs an operation of selecting the governor characteristic in response to work traveling and traveling on the road. It is possible.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings.

[Brief description of the drawings]

FIG. 1 is a side view showing an agricultural tractor with a rotary tillage device connected thereto.

FIG. 2 is a side view showing the agricultural tractor with the plow device connected thereto.

FIG. 3 is a block diagram of a transmission system.

FIG. 4 is a configuration diagram of a governor device.

FIG. 5 is a diagram showing a third governor characteristic for traveling on a road;

FIG. 6 is a diagram showing first and second governor characteristics in an automatic tilling control mode and a draft control mode.

FIG. 7 is a diagram showing a flow of selection of first, second, and third governor characteristics;

FIG. 8 is a block diagram of a lifting control system and a governor control system of the working device.

FIG. 9 is a diagram showing first and second governor characteristics in an automatic tilling control mode and a draft control mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tractor main body 2 Engine 14 Rotary tilling device 15 Traction type working device 31 Fuel supply amount adjustment mechanism 33 Electric actuator 38 Accelerator adjustment tool Gb First governor characteristic Gc Second governor characteristic n Engine speed

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B60K 25/00 B60K 25/00 A F02D 29/00 F02D 29/00 B

Claims (2)

[Claims] An automatic plowing depth control mode for automatically raising and lowering a rotary tillage device (14) connected to the tractor main unit (1) so as to be able to move up and down based on a detection result of a tillage depth detecting means. ), A draft control mode for automatically raising and lowering a tow-type working device (15) connected to the vertical movement based on the detection result of the towing load detecting means, and a work mode selection for selecting the automatic plowing depth control mode or the draft control mode. Means and a fuel supply amount adjusting mechanism (31) for an engine (2) mounted on the tractor main unit (1).
And an accelerator adjuster (38) for setting an accelerator set value of the engine (2), which is manually operated, for controlling the automatic plowing depth control mode. A first governor characteristic (Gb) whose characteristic is changed based on an accelerator setting value set by the accelerator adjuster (38); and the accelerator adjuster set for the draft control mode. A second governor characteristic (Gc) whose characteristic is changed based on the accelerator setting value set by (38), wherein the first or second governor characteristic (Gb), (G
c) is selectable, and the selected first or second governor characteristic (Gb), (G
A governor device for an agricultural tractor, wherein the electric actuator (33) operates the fuel supply amount adjusting mechanism (31) based on c). 2. The accelerator control device according to claim 1, wherein the first governor characteristic (Gb) has a maximum torque point on a high-speed side.
As the accelerator setting value set in 8) is lower, the maximum torque point is shifted to the lower speed side, and the second governor characteristic (Gc) indicates that the maximum torque point is shifted to the lower speed side. The governor for an agricultural tractor according to claim 1, wherein the maximum torque point is shifted to the lower speed side as the accelerator setting value set by the accelerator adjuster (38) is lower. apparatus.