JPH07110177B2 - Vehicle speed control device for work vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vehicle speed control device for a work vehicle,
More specifically, the transmission provided in the traveling system is interlocked with the engine, vehicle speed control means for decelerating the transmission is provided, and engine rotation detection means for detecting the engine speed of the work vehicle is provided. The present invention relates to a vehicle speed control device for a work vehicle in which the vehicle speed control means operates when the engine speed becomes lower than a deceleration processing set value.

[Prior Art] Two types of vehicle speed control methods that have been conventionally used in this type of vehicle speed control device are known. That is, the first control method is to decelerate at the time when the work vehicle enters the turning traveling state and to perform the turning traveling in the generally decelerated traveling state, and the second control method includes the turning traveling state. In any running state, the deceleration control is performed when the engine speed drops to the deceleration processing set value due to an increase in load accompanying the running.

[Problems to be Solved by the Invention] In the above-mentioned conventional technique, when the first method is adopted, even if the condition of the traveling surface, which is the main cause of the load fluctuation during turning traveling, changes, unconditionally during turning traveling. Since deceleration is performed, for example, in the case of asphalt with a smooth running surface, deceleration operation is performed even though the running load during turning is only slightly increased, and engine power cannot be used well. was there. Moreover, when the second method is adopted, the following drawbacks occur. That is, generally, in a traveling system in a traveling state, the engine speed pulsates. The deceleration processing set value as the limit value for performing the deceleration control is set to this fluctuation minimum value, but even when the engine speed falls below the deceleration processing set value in the straight traveling state, it is usually In the traveling state (straight traveling state), the rotation speed often recovers when this value is slightly divided. Therefore, in such a state, deceleration control is not always required. On the other hand, when the traveling state is not straight traveling but turning traveling, the traveling load increases with time, and as a result, if the vehicle continues to turn without gear shifting, the engine speed will drop significantly, which is a suitable engine operating range. It will be greatly deviated from. in this way,
Although the traveling load state is obviously different between straight traveling and turning traveling, conventionally, turning traveling is treated uniquely as in the first method, or as in the second method. The vehicle speed control was performed only under the condition that the two driving states were treated under the same condition and the traveling load was taken into consideration.

Therefore, an object of the present invention is to distinguish a working vehicle in a turning traveling state from that in a straight traveling state, and to accurately control the vehicle speed of the working vehicle in accordance with an increase in traveling load accompanying the turning traveling so that the working vehicle is always in a good state. To obtain a vehicle speed control device for a work vehicle that can use an engine.

[Means for Solving the Problem] In order to achieve this object, the vehicle speed control device for a working vehicle according to the present invention is provided with a turning traveling detection means for determining whether or not the working vehicle is in a turning traveling state, and the vehicle speed control is performed. The means is operated when the turning traveling state is detected by the turning traveling detecting means.

[Operation] The vehicle speed control device for a work vehicle according to the above-described characteristic configuration includes the turning traveling detection means. Then, the turning traveling detection means determines whether the work vehicle is in the turning traveling state. Here, the vehicle speed control means is configured to operate depending on the engine speed detected by the engine speed detection means, and the value of this engine speed is compared with the deceleration processing set value input in advance. To be done. The vehicle speed control means operates when the working vehicle is in the turning traveling state and the engine speed becomes lower than the deceleration processing set value. In this way, the deceleration operation is performed only when both conditions are satisfied.

[Advantages of the Invention] In this configuration, as is conventionally taken, when the vehicle is decelerated uniquely during turning, or when the engine speed drops below a predetermined value in any running state, Since the vehicle is not always decelerated and the deceleration operation is performed only when the engine speed drops below a predetermined value in the turning traveling state, the traveling load during the turning, such as on an asphalt traveling surface, is used. Avoid unnecessary deceleration operation when the increase is small, avoiding the inconvenience of wasting engine power, and conversely, if the increase in running load during turning is large, surely perform the deceleration operation to increase the load. Prevents the engine speed from deviating significantly from the suitable operating range, and at the same time, due to mere pulsation in a straight traveling state other than turning traveling When the engine rotational speed drops, the engine power can be used without waste without unnecessary deceleration operation.

[Embodiment] Hereinafter, a case where the present invention is applied to a combine vehicle speed control device as an example of a work vehicle will be described with reference to the drawings.

As shown in FIG. 5, the combine is provided with a crawler traveling device (1) and a threshing device (2) as a working device in the machine body (V), and a mowing part (3) is provided at the front part of the machine body (V). )
And a control section (4) is provided.

The cutting unit (3) is a device (5) for causing a grain rod in the field, a cutting blade (6) for cutting off the root of the raised rod, and a rear side of the machine body while changing the posture of the harvested rod into a sideways posture. Each of the transport devices (7) transports toward the threshing feed chain (8) on the side. The mowing section (3) is provided so as to be movable up and down with respect to the machine body (V).

Then, a stock origin sensor (So) which is turned on by contacting the stock origin of the grain rod to be carried at the carrying start end portion of the carrying device (7).
Is provided.

If the explanation is added, the grain rod whose stock is cut by the cutting blade (6) comes into contact with the stock sensor (So) along with the start of the cutting operation, and the stock sensor (So). Turns on,
Moreover, as the harvesting work is completed, the supply of grain rods is stopped and the stock origin sensor (So) is turned off. That is, this stock source sensor (So) functions as a work state detecting means.

As shown in FIG. 1, the engine (E) and the crawler traveling device (1) include a hydraulic continuously variable transmission (9) as a transmission and a pair of left and right steering clutch brakes (16). The engine (E) and the handling cylinder (10) of the threshing device (2) are linked together via a belt tension type threshing clutch (11).

And, the engine (E) is
A rotation speed sensor (S2) is provided as rotation detection means for detecting the rotation speed of the.

The speed change device (9) is interlockingly connected to a speed change lever (13) that is manually operated via a link mechanism (12).
A speed change motor (14) as a speed change actuator is interlockingly connected to the link mechanism (12) via a friction type transmission mechanism (15). That is, while the gear shift lever (13) can be artificially operated for gear shift, the gear shift motor (14) can also be used for gear shift operation automatically. The pair of steering clutch brakes (16) can be switched in four stages by a control valve (17). That is, there are four stages of "normal rotation", "clutch disengagement", "clutch disengagement and braking", and "reverse rotation".

The control valve (17) is connected to the operation lever (18) so that it can be artificially operated. The operating lever (18) is also connected to the elevating control valve (19) of the mowing section (3).

Although not described in detail, the operation lever (18) is of a cross swing type and is biased to return to the neutral position (N). Then, it can swing to the left and right in three steps. For example, 1 to the right
When swinging in stages, the power to the right traveling device (1) is shut off. When the vehicle is swung up to two steps, the braking force is further applied to the traveling device (1) on the right side. Then, in the third stage, reverse power is applied to the right traveling device (1). When it is swung to the left side, it also acts on the traveling device (1) on the left side. When the operating lever (18) is swung rearward, the mowing section (3) is raised, and when it is swung forward, the mowing section (3) is lowered so that the mowing section (3) is lowered. It is configured to operate the lifting cylinder (20).

In the vicinity of the base of the operation lever (18), a turning sensor (S1) as a turning running detection means (S1), a neutral sensor (Sn) for detecting whether the operation state is neutral, and a backward running state are also provided. There is a back sensor (Sb) that detects whether there is one. Here, the turning sensor (S1) is for detecting whether or not the work vehicle is in a turning traveling state, and the turning lever (1
When 8) is held at the machine base turning position for a certain time, this is detected as a turning signal. All the detection information of these three types of sensors (S1) (Sn) (Sb) is collected in the vehicle speed control means (100) provided in the vehicle speed control device.

The vehicle speed control means (100) using a microcomputer for operating the speed change motor (14) to control the vehicle speed will be described below. This vehicle speed control means (100)
FIG. 2 shows the operation flow of the above.

This flow is a flow for determining whether or not to perform the deceleration control process as the process operation in step 3, and has two determination steps. First, in the first step, it is determined whether or not the traveling state of the work vehicle satisfies the starting condition. As a criterion for this,
Information from the above-mentioned sensors (S0) (S1) (Sn) (Sb) is judged. That is, the neutral sensor (Sn) and the back sensor (Sb) are in the off state because the work vehicle is traveling forward, and the root sensor (S0) is in the off state because the mowing operation is not performed. It is determined that the turning sensor (S1) is in the ON state from the fact that the work vehicle is turning and that the work vehicle is turning. When these conditions are satisfied, the operation flow moves to step 2. If the condition is not satisfied, the deceleration control will not be performed. Now, in step 2, the current engine speed (R) of the engine (E) detected by the speed sensor (S2) is determined. That is, this engine speed (R) is compared with the preset deceleration processing set value (X). Then, when the engine speed (R) is lower than the deceleration processing set value (X), the operation proceeds to step 3 which is the operation flow of the deceleration control processing, and when it is high, the same processing as described above is not performed. Now, here is the property of the deceleration processing set value (X), which is the number of revolutions that requires deceleration processing when the engine is under load as described above.

In this way, the vehicle speed control means (100) performs the deceleration control only when the engine speed (R) becomes equal to or less than the deceleration processing set value (X) in the turning traveling state.

[Other Embodiment] Next, a second embodiment of the vehicle speed control means (100) will be described based on the operation flow shown in FIG. This example is also a flow for determining whether or not to perform the deceleration control process in step 3, and steps 2 and 3 are the same as those in the above-described first embodiment. Now, in this example, step 1 is determined by the duration of the turning traveling state. That is, the turning sensor (S1) is configured as a mechanism that detects only the position of the operation lever (18), and this has a timer and detects the time when the operation lever (18) is in the turning position. Then, when the turning operation is continuously performed for a certain period of time or longer, it is determined that the turning traveling is accompanied by an increase in running load, and the deceleration control process is executed.

Further, a third embodiment of the vehicle speed control means (100) will be described based on the operation flow shown in FIG. This embodiment is also a flow for determining whether or not to execute the deceleration control process, but in this example, the deceleration process setting value (X) set in advance as described above is not used. Instead of this value, the working state engine speed (Rt) in the traveling state selected and selected by the driver during the cutting and threshing process is used as a reference. For this purpose, in this embodiment, a storage means (M) for averaging and storing the number of revolutions at that time is provided in association with the engine rotation detecting means (S2) shown by the two-dot chain line in FIG. Now, this operation flow will be described below.

In this flow, when the work vehicle is in the mowing and threshing work state, the operation shifts to step 1a by step 1 which is the determination step. Then, in step 1a, the engine speeds from the speed sensor (S2) are averaged, and the averaged engine speeds (R
It is stored as t). Moreover, this process is continuously performed as long as the work vehicle cutting operation is continued. Therefore, working condition engine speed (Rt)
As for, the number of revolutions of the work state at the end of the work state is stored. As shown in the figure, this step 1a is completed by this, and the deceleration control process is not performed here. Now, once the mowing state is over,
This operation flow is configured to shift from step 1 to step 2. Such a state corresponds to a state in which the combine in the actual field finishes the cutting up to the edge of the field and enters the turning state. Here, in step 2, it is determined whether or not the combine is turning. If the combine is turning, the process proceeds to step 3, otherwise, the deceleration control process is not performed. Now, in step 3, the engine speed (R) at this time is compared with the value obtained by subtracting the margin value (I) from the working state engine speed (R1). Then, as a result, when the engine speed (R) is low, the deceleration control process of step 4 is performed. Here, the above-mentioned margin value (I) is a positive value, and in general, the engine speed (Rt) determined by the operator based on the engine sound, the operation sound of the threshing device (2), etc., during the mowing work is the engine speed (Rt). This is an empirical value that is determined with the intention of effectively utilizing this margin area by utilizing the fact that it is higher than the allowable minimum operating speed of. And
In this embodiment, the value obtained by subtracting the margin value (I) from the working state engine speed (Rt) is the deceleration processing set value (X).
To work as. Also in this example, the deceleration control process is performed only when the combine is in a turning state and the engine speed (R) at that time is equal to or less than the deceleration process set value (X).

In the above-described first to third embodiments, the turning sensor (S1) as the turning traveling detection means (S1) is provided at the base of the operation lever (18), and the turning state is detected by detecting the position thereof. However, this may be manually operated by the operator.

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

[Brief description of drawings]

The drawings show an embodiment of the present application, FIG. 1 is a mechanism diagram of a traveling system and a control system, FIG. 2 is a diagram showing an operation flow of vehicle speed control means in the first embodiment, and FIG. 3 is a view in the second embodiment. FIG. 4 is a diagram showing an operation flow of the vehicle speed control means, FIG. 4 is a diagram showing an operation flow of the vehicle speed control means in the third embodiment, and FIG. 5 is a side view of the combine. (9) …… Transmission, (E) …… Engine, (S1) ……
Turning traveling detection means, (S2) ... Engine rotation detection means,
(100) …… Vehicle speed control means.

Claims (1)

[Claims] 1. A vehicle speed control means (100) for decelerating and controlling the transmission (9) is provided while interlockingly connecting a transmission (9) equipped to a traveling system to an engine (E). The engine speed detection means (S2) for detecting the engine speed (R) is provided, and when the engine speed (R) becomes lower than the deceleration processing set value (X), the vehicle speed control means (100) In a vehicle speed control device for an operating work vehicle, a turning traveling detection means (S1) for determining whether or not the working vehicle is in a turning traveling state is provided, and the vehicle speed control means (100) is
A vehicle speed control device for a working vehicle, which operates when the turning traveling state is detected by the turning traveling detecting means (S1).