JPH0755094B2 - 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, a transmission equipped in a traveling system is interlocked with an engine, vehicle speed control means for decelerating the transmission is provided, and a turning vehicle for determining whether or not the work vehicle is in a turning traveling state. When the work vehicle is in the turning traveling state and the engine speed becomes lower than the deceleration processing set value, the vehicle is provided with a traveling detection means and an engine rotation detection means for detecting an engine speed of the work vehicle. The present invention relates to a vehicle speed control device for a work vehicle in which the vehicle speed control means operates.

[Prior Art] Conventionally, in this type of vehicle speed control device, mainly two types of vehicle speed control methods when turning are known. That is, the first control method is to perform deceleration control at the time when the work vehicle enters the turning traveling state and try to perform the turning traveling in the traveling state in which the work vehicle is decelerated by one step. In any running state including the above, when the engine speed decreases to the deceleration processing set value due to an increase in load accompanying traveling, the deceleration control is performed to shift gears.

These methods have a drawback that the engine power cannot be effectively used depending on the condition of the road surface or the running condition. Therefore, it is proposed that the deceleration control process is performed only when the work vehicle is in a turning traveling state and the engine speed is lower than the deceleration processing set value due to the load accompanying the turning traveling.

[Problems to be Solved by the Invention] When the control method having the above-mentioned structure is adopted, the conventional deceleration processing set value is set regardless of the engine speed in the straight traveling state before the turning traveling. It has been determined in advance as an engine speed that requires a deceleration process due to a running load in a state where the engine is used at the maximum output.
Therefore, the necessity of the deceleration control process has not been determined based on the actual engine speed as an accurate representation of the actual engine usage. In such a device, for example, a combine harvester will be described as an example.After finishing the mowing and threshing work, the driver simply goes straight ahead and the operator changes the accelerator setting to a low rotation side, and then tries to make a turning run. In this case, the engine speed may be set below the deceleration processing set value, which satisfies the condition that the deceleration processing is performed only during turning. The required deceleration control was to be performed.

Therefore, an object of the present invention is to eliminate the above-mentioned conventional drawbacks, and when decelerating control of a work vehicle in a turning traveling state, the state of the engine at the time of straight traveling before turning is taken into consideration, whereby the deceleration control is performed. The object is to obtain a vehicle speed control device for a work vehicle that can properly determine necessity and can always use an engine in good condition without waste.

[Means for Solving the Problems] In order to achieve this object, the first invention of the present application is a vehicle speed control device for a work vehicle, wherein the vehicle speed control means sets the deceleration processing set value according to an engine speed before turning. Further, the second invention of the present application, in the above configuration,
When the engine speed during turning is lower than a value obtained by adding a margin value to the reference target value, the vehicle speed control means sets a value obtained by subtracting the allowance value from the engine speed before turning as the deceleration processing set value. If the engine speed during turning is higher than the value obtained by adding the reference target value and the margin value, the reference target value is selected as the deceleration processing set value. That is.

[Operation] This vehicle speed control device of the work vehicle has a vehicle speed control means, and the vehicle speed control means operates when the work vehicle is in the turning traveling state and the engine speed becomes lower than the deceleration processing set value. .

Then, according to the first characteristic configuration of the present application, the deceleration processing set value is determined based on the engine speed before turning.
That is, for example, when the engine speed before turning is a relatively high value and the engine is used in a good condition, the deceleration processing set value is determined as a standard value, and the engine speed before turning is low. When the engine is used in a state that deviates from the ideal state, the deceleration processing set value suitable for this state is determined from the engine speed before turning, and the deceleration control processing is performed based on this criterion. Is to

According to the second characteristic configuration, the engine speed before turning and the value obtained by adding a margin value to the reference target value as the deceleration processing value when the engine is used in an ideal state are compared, and the accelerator A state where the setting is appropriate and the engine is used at the maximum output and there is a margin is distinguished from a state where the accelerator setting is lower than the ideal state and the engine output is used without the margin. Then, in the former case, the reference target value is selected as the deceleration processing set value, thereby determining whether to execute the deceleration control processing, and in the latter case, a value obtained by subtracting the margin value from the actual engine speed before turning is used. It is selected as the deceleration processing set value, and it is determined whether or not to execute the deceleration control processing based on this selection value.

[Effects of the Invention] Therefore, in the configuration of the first invention of the present application, the actual use state of the engine is judged from the engine speed before turning,
In addition, the optimum deceleration control processing is performed according to the turning load at the time of turning, so unnecessary deceleration processing is avoided while preventing problems such as engine stalls and efficient engine output is achieved without waste. Can be used.

Further, since the deceleration processing set value is not a fixed value as the deceleration control value in the maximum output state as in the conventional case, but the engine speed before turning is used to determine the deceleration processing set value, for example, in a combine, at the beginning of cutting, The deceleration process during turning is not affected by changes in the accelerator settings of the work vehicle during mowing, etc., and avoids a situation where engine stalls even when the traveling load increases significantly due to super-textile turning. can do.

In the configuration of the second invention, the engine speed before turning and the value obtained by adding the margin value to the reference target value are compared,
Since the deceleration process set value is determined as a value suitable for each state, the deceleration control is performed in consideration of the margin value rather than the deceleration control that is determined only by the reference target value as in the conventional case. It was possible to obtain a control device suitable for the above purpose.

[Example] 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. 3, 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 section (3) is provided at the front part of the machine body (V). )
And a control section (4) is provided.

The reaping unit (3) is a device for causing a grain culm in the field (5), a cutting blade (6) for cutting the root of the grain culm that has been caused, a rearward of the machine body while changing the posture of the harvested grain culm to 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).

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).

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

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).

Further, a turning sensor (S1) as a turning traveling detection means (S1) is provided near the base of the operation lever (18). Here, the turning sensor (S1) is for detecting whether or not the work vehicle is in a turning traveling state, and when the operating lever (18) is kept in the turning position of the machine base for a certain period of time, the turning signal is given. Is detected as. The detection information of the turning traveling detection means (S1) and the engine rotation detection means (S2) described above is used as the vehicle speed control means (10) provided in the vehicle speed control device.
0).

The vehicle speed control means (100) using a microcomputer for operating the speed changing motor (14) to decelerate 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 the deceleration control process as the processing operation in step 5 is performed, and also has a function of determining what reference value the deceleration control should be performed on.

The steps will be described step by step.

In this flow, when the work vehicle is in the non-turning state,
The process proceeds from step 1a, which is a determination step, to step 1a. In this step 1a, the engine speed (R) from the speed sensor (S2) is averaged and stored as the straight running engine speed (Rx). And this process is continuously continued as long as the straight traveling of the work vehicle continues. Therefore, the rotation speed at the end of the straight travel state is stored as the straight travel engine rotation speed (Rx). As shown in the figure, this step 1a is completed by this, and the deceleration control process is not performed. Now, such a straight traveling state is performed during the cutting operation or during simple traveling, but when this is finished and the vehicle enters the turning traveling state, the operation flow shifts 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 end of the field and enters the turning state. Prior to entering this turning state, a skilled worker such as a weeding contractor has conventionally performed work by lowering the accelerator setting of a work vehicle that is still traveling straight ahead at the stage when the combine comes out to the headland. As a result, the engine speed was greatly reduced when turning, which caused a problem. Therefore, in the present application, in step 2, the straight traveling engine speed (Rx) of the combine is compared with a value obtained by adding a margin value (I) to the reference target value (Ri). If the rotation speed (Rx) is low, the process proceeds to step 3, and if it is high, the process proceeds to step 4. Here, the above-mentioned reference target value (Ri) is
When the engine is in the maximum output state, it is considered that decelerating traveling is required when a load is applied. The above-mentioned margin value (I) indicates that the operator is in good operating condition due to engine noise when traveling straight ahead. It is an empirical speed that is a margin between the engine speed in consideration and the speed allowed for the actual engine. In this state, the straight running engine speed (Rx) that causes the transition to step 3
Means that the accelerator setting was low in the straight running state, and the straight running engine speed (Rx) causing the transition to step 4 has a good accelerator setting in the straight running state. It means that the engine was used with sufficient power. Therefore, in order to avoid unnecessary deceleration control processing at the time of turning, the reference value as the deceleration processing set value (X) for whether to perform the deceleration control processing is changed according to the situation.
That is, in step 3, a value obtained by subtracting the margin value (I) from the straight traveling engine speed (Rx) is selected as the deceleration processing set value (X), and when the current engine speed (R) is lower than this value. First, the deceleration control process of step 5 is performed, and if it is high, this process is not performed. Further, in step 4, the above-mentioned reference target value (Ri) which is normally used is selected as the deceleration processing set value (X), and when the current engine speed (R) is lower than this, the step 5 The deceleration control process is performed,
If it is higher, the processing is not performed.
Therefore, in this control system, the deceleration control process at the time of turning traveling is to be performed based on the two values determined based on the engine speed in the normal traveling state.

[Other Embodiments] In the above-described embodiment, the turning sensor 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 of the turning sensor. 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, and FIG. 3 is a side view of a combine. (9) …… Transmission, (E) …… Engine, (S1) ……
Turning traveling detection means, (S2) ... Engine rotation detection means,
(100) …… Vehicle speed control means.

Claims (2)

[Claims] 1. A vehicle speed control means (100) for decelerating and controlling the transmission (9) is provided while interlockingly connecting a transmission (9) mounted on a traveling system to an engine (E). The vehicle includes the turning traveling detection means (S1) for determining whether or not the vehicle is in a turning traveling state and the engine rotation detection means (S2) for detecting an engine speed (R) of the working vehicle, and the working vehicle is for the turning traveling. In the vehicle speed control device for a working vehicle, the vehicle speed control means (100) operates when the engine speed (R) is lower than the deceleration processing set value (X) in the state. (100) is a vehicle speed control device for a work vehicle, which determines the deceleration processing set value (X) based on the engine speed (Rx) before turning. 2. The vehicle speed control means (100) is configured so that an engine speed (R) during turning is a reference target value (Ri).
If the value is lower than the value obtained by adding the allowance value (I) to, the value obtained by subtracting the allowance value (I) from the engine speed (Rx) before turning is selected as the deceleration processing set value (X). Yes, when the engine speed (R) during turning is higher than a value obtained by adding the reference target value (Ri) and the margin value (I), the reference target value (Ri) is set to the deceleration processing set value ( X)
The vehicle speed control device for a work vehicle according to claim 1, which is selected as.