JP3932627B2 - Steering shift control device for agricultural vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steering shift control device for an agricultural vehicle, and allows a steering shift to be performed when turning, and can be used for agricultural tractors, rice transplanters, lawn mowers, and the like.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, farm vehicles such as tractors often return and reciprocate during field work, and in order to facilitate the steering operation at the time of turning, the speed ratio of the steering angle of the front wheel to the steering angle of the steering wheel, That is, a device equipped with a steering shift control device that increases or decreases the steering shift is known.
[0003]
However, when the steering shift control device is operated according to the steering operation speed of the vehicle, the operation start position varies depending on various conditions during the work and the skill level of the operator. Therefore, if the steering shift start and end positions fluctuate, for example, if the control is canceled at the neutral return position of the front wheels, the wheel steering end position is not constant. Correction operation is required, and operability becomes difficult.
[0004]
[Means for Solving the Problems]
According to the present invention, a steering shift control device for an agricultural vehicle is configured as follows to solve the above-described problems. That is, in a steering shift control device for a farm vehicle configured such that the steering speed of the steering wheels 5 and 5 can be changed according to the steering operation speed of the vehicle body 1, the steering position detection for detecting the steering position in the vehicle body 1. Means S1 is provided, and the steering position detection means S1 detects the steering angle and the steering speed of the steering wheels 5 and 5, and storage means M1 for storing the detected values is provided to start steering shift control. A control start angle setting dial D1 for the steered wheels 5 and 5 for setting the possible region and a cut angular speed setting dial D2 for setting the cut angular speed of the steered wheels 5 and 5 for starting the steering shift control are provided. The steering position A at the start of the shift control is detected by the steering position detection means S1 every time steering is performed, and the detected value is stored in the storage means M1 as a start position. Manipulate the start position stored in the storage means M1 It is configured to be stored in the steering gear releasing means M2 as the shift release position, when each Ru is provided neutral dead zone in the release position and the start position of the steering gear control, the steering gear control a time of turning start The neutral dead zone area of the steering wheel 4 when the acceleration output is started from the state where the acceleration output is not performed is set to a neutral ± 1/8 rotation range, and the steering handle 4 exceeds the neutral ± 1/8 rotation range. If the control is operated, the output of the steering shift control is increased and the neutral dead zone region of the steering shift control is widely changed to the neutral ± 1/4 rotation range. When the vehicle returns to the neutral ± 1/4 rotation range of the neutral dead zone, the output of the steering shift control is stopped and the neutral dead zone region of the steering shift control is changed to the neutral ± 1/8 rotation range. You Was agricultural vehicle steering transmission control apparatus characterized by being configured so.
[0005]
【The invention's effect】
The steering shift start position changes depending on the control start angle setting dial D1 and the cutting angular speed setting dial D2, but also changes depending on the state of the traveling ground.
In the turning operation of the vehicle body, the steering speed of the steering wheels 5 and 5 is changed by the steering shift control device 2 when the steering speed by the steering operation becomes a certain level or more. At this time, every time steering is performed, the steering position A is detected by the steering position detection means S1, and this detected value is stored in the storage means M1 as the start position, and at the same time, the start position stored in the storage means M1 is controlled. It is also stored in the steering shift canceling means M2 as the direction shift canceling position.
[0006]
A neutral dead zone region is provided at the start position and the release position of the steering shift control, respectively, but the neutral dead zone region is different between the start position and the release position of the steering shift control. That is, the neutral dead zone region of the steering handle 4 when starting the turning from the state where the turning output of the steering shift control is not performed at the start of turning is set to a neutral ± 1/8 rotation region. When the steering handle 4 is operated beyond the neutral ± 1/8 rotation range, the speed increasing output of the steering shift control is performed and the neutral dead zone region of the steering shift control is widely changed to the neutral ± 1/4 rotation range. Set.
When the steering handle 4 returns to the neutral ± 1/4 rotation range of the neutral dead zone where the steering wheel 4 is widely changed, the speed increasing output of the steering shift control is stopped and the neutral dead zone of the steering shift control is neutral ± 1 / Change the setting narrowly to 8 rotations.
As a result, the steering handle 4 becomes neutral after the acceleration output of the steering shift control stops with respect to the time from when the steering handle 4 leaves neutral until the acceleration output of the steering shift control is started. The time to become longer. That is, since the speed-increasing output of the steering gear control at positions remote steering handle 4 from the neutral is stopped, when the strip together for pivoting after the end agricultural vehicles, by stopping the output early conditions combined performs It becomes easy.
Further, the acceleration output of the steering shift control is started after the steering handle 4 leaves the neutral position with respect to the time from when the acceleration output of the steering shift control stops until the steering handle 4 becomes neutral. Since the time until the time is shortened, a quick steering turn can be performed by increasing the speed output early.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described for an agricultural tractor.
The vehicle body 1 is in the form of a riding tractor and has a four-wheel drive configuration in which a front wheel 5 and a rear wheel that can be steered by a steering handle 4 can be transmitted by an engine mounted on the front. The steering of the front wheel 5 is a turning operation of the steering handle 4, the power steering hydraulic circuit 6, the steering transmission hydraulic circuit 7, etc., and the double-acting steering cylinder 8 and piston 9 are operated. The steering rod 10 integrated with the steering wheel 9 is connected to the steering arm 11 so that the front wheel 5 is steered and linked.
[0008]
T is a tank port, P is a hydraulic pump, and 12 is a front axle housing. Steering cases that can be steered by a steering arm 11 are provided on both the left and right sides, and the front wheels 5 are mounted so as to be capable of transmission. The steering speed change hydraulic circuit 7 is provided with a switching control valve 13 that switches between a total pressure circuit V2 and a pressure reducing circuit V1 that discharges to the tank port T by an electromagnetic solenoid SL1, and normally the pressure reducing circuit V1. This reduces the amount of oil supplied to the steering cylinder 8 and lowers the steering shift, but the steering shift can be increased by switching to the full pressure circuit V2 by the output of the electromagnetic solenoid SL1. it can.
[0009]
A turning portion of the steering arm 11 that steers the front wheel 5 is provided with a front wheel turning angle sensor (steering position detecting means) S1 including a potentiometer, and the steering angle (cutting angle) of the front wheel 5 The steering speed (cutting angle speed) is detected.
The controller 14 includes storage means such as a CPU for processing various signals, a RAM (storage means) (M1) for temporarily storing detection values, and a ROM (steering shift release means) (M2) for storing control programs. On the input side, in addition to the turning angle sensor S1, a control on / off switch SW1, which is a power switch for control, and a control of the front wheel 5 for setting a steering shift control startable region, that is, a control check region, are set. Start angle setting dial D1, front wheel cutting angular speed setting dial D2 for setting the cutting angular speed of the front wheel 5 for starting the steering shifting control, and traveling speed shift for setting a region where steering shifting control is possible by the traveling speed A position switch SW2 and the like are included. On the output side of the controller 14, an electromagnetic solenoid SL1 for switching the switching control valve 13 of the steering shift hydraulic circuit 7 is provided.
[0010]
The steering start angle setting dial D1, the front wheel turning angular speed setting dial D2, the front wheel turning angle sensor S1, and the like as the steering shift control conditions are a steering wheel turning angle sensor S2 that detects a turning angle of the steering handle 4. It is good also as a structure which replaces these by providing. However, in a configuration that requires detecting the steering speed of the front wheel 5 after the steering shift, that is, the cutting angle speed, the front wheel cutting angle sensor S1 is provided together.
[0011]
The graph of FIG. 4 shows the relationship with the front wheel turning angle detected by the front wheel turning angle sensor S1 when the turning angle of the steering wheel 4 is detected by the steering wheel turning angle sensor S2, and the front wheel turning angular velocity is set on the setting dial D2. When the value is less than a predetermined value, the switching control valve 13 is in the pressure reducing circuit V1, and the front wheel is steered according to a constant gentle gradient straight line L1. On the other hand, when the front wheel turning angular velocity is equal to or greater than a certain value, the switching control valve 13 is switched to the total pressure circuit V2, and the front wheel steering is performed from this position according to the steep straight line L2. That is, the steering shift is performed.
[0012]
The steering shift start position P1 varies depending on the shift position of the vehicle body traveling speed, the state of the traveling ground, and the like in addition to the setting conditions by the control start angle setting dial D1, the front wheel turning angular speed setting dial D2, and the like. To do. Here, the steering position A at the start of the steering shift control is detected by the front wheel turning angle sensor S1 and stored in the RAM (M1) of the controller 14 as the start position P1 or P2, and the steering is performed. The shift release position is stored in the ROM (M2), and when the turning in the vehicle traveling direction by the steering shift is finished and the stored start position P1 or P2 is restored as shown in FIG. It is the structure which cancels | releases.
[0013]
In this way, even if the steering position A at which the steering shift control by the steering shift control device 2 starts is changed to the start positions P1 and P2 depending on the traveling conditions, the steering shift canceling device 3 of this control changes. Since the release position also follows these start positions P1 or P2, even if the driving conditions change from these start positions to the return of steering by the shift control, this shift position is not affected. The control release position is already determined at the start position P1 or P2, and stable steering control and steering operation can be performed.
[0014]
In addition, although the case where the release position of the shift control is made coincident with the start positions P1 and P2 is shown, the start positions P1 and P2 may be released in a substantially constant region near the reference position. The soil steering angle area may be set, or may be set to an area appropriately delayed by a delay timer.
In FIG. 5, the difference from the above example is that in the steering shift control, the front wheel turning angle shift by the front wheel turning angle sensor S1 or the steering wheel turning angle speed by the steering wheel turning angle sensor S2 is greater than or equal to a certain value set by the setting dial D2. The steering shift control is started when it is detected that the neutral dead zone region ± α is provided for the detected value of the cut angular velocity above a certain level.
[0015]
For example, when the steering handle 4 is taken on an uneven surface or the like of a field when working with a tractor tillage device, the switching control valve 13 of the power steering hydraulic circuit 6 is not switched rapidly so that the operation is uncomfortable. Do not give. When this operation speed exceeds the neutral dead zone region ± α, the power steering speed is increased.
In addition, the neutral dead zone region may be configured to be changed in a wide and narrow manner with an adjustment dial or the like according to traveling conditions and the like.
[0016]
In FIG. 6, the difference from the above example is that a neutral dead zone region for turning on and off the electromagnetic solenoid SL1 of the steering shift control output is provided separately so that the ON timing and the OFF timing can be appropriately shifted. It is a thing. For example, when the speed increasing output of the power steering is ON, the dead zone is set to the neutral ± 1/4 rotation range, and when the speed increasing output is OFF, the dead zone is set to the neutral ± 1/8 rotation range.
[0017]
In this way, the speed increase output of the steering shift control is performed early, and a quick steering turn is performed. When adjusting the tractor work strip after the turn, the output is stopped early to facilitate the alignment. If this is performed at exactly the same position A as described above, the operation is adjusted after the neutral position at the time of return from turning, and the alignment becomes difficult.
[Brief description of the drawings]
FIG. 1 is a power steering hydraulic circuit diagram of a tractor.
FIG. 2 is a block diagram of a steering shift control unit.
FIG. 3 is a flowchart thereof.
FIG. 4 is a steering shift control graph.
FIG. 5 is a flowchart of part of steering shift control showing another embodiment.
FIG. 6 is a flowchart of part of the steering shift control showing another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Car body 2 Steering speed change control apparatus 4 Steering handle 5 Front wheel (steering wheel)
14 Controller A Steering position D1 Control start angle setting dial D2 Cutting angular speed setting dial M1 RAM (storage means)
M2 ROM (steering shift release means)
S1 Front wheel turning angle sensor (steering position detection means)

Claims (1)

In a steering shift control device for a farm vehicle configured such that the steering speed of the steering wheel (5, 5) can be changed according to the steering operation speed of the vehicle body (1), the steering position is detected in the vehicle body (1). Steering position detection means (S1) is provided, and the steering position detection means (S1) detects the steering angle and steering speed of the steering wheel (5, 5) and stores the detected values. (M1) is provided, and a control start angle setting dial (D1) of the steered wheel (5, 5) for setting the startable region of the steered shift control and the steered wheel (5, 5) for starting the steered shift control are provided. 5) A cutting speed setting dial (D2) for setting the cutting speed is provided, and the steering position detection means (S1) is used to determine the steering position (A) at the start of the steering shift control every time steering is performed. And detecting the detected value as a start position in the storage means (M1) In addition, the start position stored in the storage means (M1) is also stored in the steering shift release means (M2) as the steering shift release position, and the steering shift control start position and release position are respectively upon Ru provided neutral dead zone, the neutral dead zone of the steering wheel (4) when a time of turning start starts accelerating output from the state of not being the accelerated output of the steering shift control, neutral ± 1 When the steering handle (4) is operated beyond the neutral ± 1/8 rotation range, the steering shift control speed increasing output is generated and the steering shift control neutral dead zone region is set. The configuration is such that the neutral ± 1/4 rotation range is widely changed, and the steering shift control speed increases when the steering handle (4) returns to the neutral ± 1/4 rotation range of the widely changed neutral dead zone region. Stop output A steering shift control device for a farm vehicle characterized in that the neutral dead zone region of the steering shift control is narrowly changed to a neutral ± 1/8 rotation range .

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