JPH0415366A - Work vehicle speed control device - Google Patents

Abstract

PURPOSE:To properly lighten the load in accordance with the operation state of a sub speed change gear by automatically set-changing the target car speed to the high speed side when the sub speed change gear is operated to the high speed side in comparison with the case where the sub speed change gear is operated to the low speed side. CONSTITUTION:When the number of revolution detected by a revolution speed sensor S1 reduces less than the set revolution speed corresponding to a set value, a speed change gears 3 is automatically deceleration-operated by an electric motor 9, and the engine load as a whole is kept less than a set value. Even if the deceleration quantity of the main speed change gear 3 is equal, the deceleration quantity for the actual car speed becomes larger in case of 'traveling' of a sub speed change gear 6 than that in case of 'standard'. Accordingly, the aimed deceleration car speed value in the case where the sub speed change gear 6 is in 'traveling' on the high speed side is set to the high speed side than the target car speed value in the case where the sub speed change gear 6 is in the 'standard' on the low speed side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a main transmission device for traveling and a sub-transmission device for traveling connected in series to an engine, and a load detection means for detecting the load of the engine. , vehicle speed detection means for detecting vehicle speed;
Based on the information of the load detection means and the vehicle speed detection means, when the load becomes larger than a set value, the amount of deceleration determined according to the difference between the detected vehicle speed and a preset target vehicle speed to be decelerated. The present invention relates to a vehicle speed control device for a working vehicle, which is provided with a control means for automatically decelerating the main transmission device.

[Prior Art] The vehicle speed control device for this type of work vehicle described above performs feedback control to reduce the speed to a target vehicle speed set corresponding to the detected vehicle speed, for example, when the engine is overloaded. By decelerating the vehicle by a preset amount of deceleration, the response delay of the control system can be reduced.

In addition, since work vehicles are often driven at a low, almost constant speed during work, if they are driven on the road while not working, for example, the vehicle speed will drop. If it is too low, there is a disadvantage that movement efficiency will be poor.

However, although it is possible to change the vehicle speed between working and non-working by operating the transmission, the operation is cumbersome.

Therefore, conventionally, it has been considered to provide a sub-transmission device that can change the vehicle speed without changing the speed of the main transmission device.

[Problems to be Solved by the Invention] However, when a sub-transmission is provided in addition to the main transmission, the following disadvantages occur.

In other words, the gear ratio is different when the sub-transmission is operated to a low speed side and when it is operated to a high speed side, so even if the amount of operation of the main transmission is the same, the vehicle speed will be different depending on the amount of operation. The amount of change is smaller on the low speed side than on the high speed side.

Therefore, even if the target vehicle speed that should be reduced when the engine becomes overloaded is set to the same value regardless of the operating state of the sub-transmission device, there is a risk that the overload condition will not be resolved. be.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to enable accurate load reduction depending on the operating state of the sub-transmission device.

[Means to solve the problem]

A vehicle speed control device for a work vehicle according to the present invention includes a main transmission for traveling and a sub-transmission for traveling connected in series with an engine, a load detection means for detecting the load of the engine, and a vehicle speed detection means for detecting the vehicle speed. and based on the information of the load detection means and the vehicle speed detection means, if the load becomes larger than a set value, the vehicle speed is determined according to the difference between the detected vehicle speed and a preset target vehicle speed to be decelerated. A control means for automatically decelerating the main transmission by a required deceleration amount is provided, and its characteristic configuration is as follows.

A first characteristic configuration is that a shift state detection means is provided for detecting an operating state of the auxiliary transmission, and the control means is configured to control the auxiliary transmission to be operated to a low speed side when the auxiliary transmission is operated to a high speed side. The present invention is configured to automatically change the setting of the target vehicle speed based on information from the shift state detecting means so that the target vehicle speed is higher than when the target vehicle speed is set.

A second characteristic configuration is that, when the engine load becomes higher than a set value, the speed change state detecting means sets the detected vehicle speed to a high speed when the detected vehicle speed is higher than the set vehicle speed, and the detected vehicle speed is lower than or equal to the set vehicle speed. The structure is configured to determine that the speed is low if the speed is low.

A third characteristic configuration is that the vehicle speed detecting means is configured to detect the vehicle speed based on the amount of rotation per unit time of a rotating body located on the downstream side of transmission from the main transmission and the auxiliary transmission. , the control means is configured to perform a deceleration operation using a preset initial deceleration amount, and then calculate a later deceleration amount based on the detection information of the shift state detection means, and perform a deceleration operation by determining a later deceleration amount based on the detection information of the shift state detection means. , the speed change state is determined based on the amount of vehicle speed deceleration when a deceleration operation is performed using the initial deceleration amount.

[Function] As mentioned above (even if the main transmission is operated with the same amount of operation, when the sub-transmission is on the high-speed side, the gear ratio is smaller than on the low-speed side, so the amount of change with respect to the actual vehicle speed is It is larger on the high speed side than on the low speed side.However, since the auxiliary transmission is operated to the high speed side because you originally want to drive at high speed, even if you decelerate to reduce the load, if you decelerate too much, the transmission will be damaged. There is a risk that it will become unnatural in response to manipulation.

Therefore, in the first characteristic configuration, for example, as shown in FIG. 3, when the sub-transmission is on the high-speed side, the value of the target vehicle speed to be decelerated is set to a value on the high-speed side rather than when it is on the low-speed side. I am trying to set it to . In addition, in Fig. 3, in order to correspond to the embodiment, the low speed side is expressed as "'standard".
The high speed side is written as "driving".

By the way, when configuring the gear change state detection means for detecting the gear change state of the sub-transmission device, it is usually configured as a sensor using a switch, a potentiometer, etc. that physically detects the operating state of the sub-transmission device. Even if the main transmission is operated with the same amount of operation, the gear ratio will be smaller when the sub-transmission is on the high-speed side than on the low-speed side, so the amount of change in actual vehicle speed will be greater on the high-speed side than on the low-speed side. It is possible to detect the gear change state of the sub-transmission device without using a sensor or the like by utilizing the characteristic that the value increases.

Therefore, in the second characteristic configuration, when the engine load is higher than the set value, the gear change state detecting means is set to a high speed if the vehicle speed detected by the vehicle speed detecting means is higher than the set vehicle speed, and the detected vehicle speed is set to high speed. If the vehicle speed is less than the set vehicle speed, it is determined to be low speed.

Further, in the third characteristic configuration, the vehicle speed is detected on the lower transmission side than the main transmission and the auxiliary transmission, and the control means is configured to:
Preset first! After decelerating at a speed of 1111,
By configuring the vehicle to perform a deceleration operation by determining a late deceleration amount based on the detection information of the shift state detection means, it is possible to detect a change in vehicle speed when a deceleration operation is performed using an initial deceleration amount that is not affected by the detected vehicle speed. In this way, the speed change state is determined based on the amount of vehicle speed deceleration when a deceleration operation is performed using the initial deceleration amount.

[As a result of the invention, in the first characteristic configuration, it has become possible to accurately reduce the load according to the operating state of the sub-transmission device.

In addition, in the second and third characteristic configurations, the speed change state detection means for detecting the speed change state of the auxiliary transmission device is not provided as a physical device using a sensor or the like, but the vehicle speed detection means originally provided in the device can be used. Since the information can be effectively used to determine the gear change state, the device configuration can be simplified and the cost can be reduced.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, a first embodiment in which the present invention is applied to a vehicle speed control device for a combine harvester will be described based on the drawings.

As shown in Fig. 1, the output of the engine (E) is transmitted to the threshing device (1) and the reaping section (2) as working devices, and is also transmitted to the main transmission (3) for traveling. transmitted,
The output of the main transmission (3) is
) Sub-transmission device (6) installed in the mission section (5) of
It is designed to be transmitted to In other words, the main transmission for traveling (3) and the auxiliary transmission for traveling (6) are connected in series to the engine (E). Although not described in detail, power transmission between each part is performed by a heald or the like.

The main transmission (3) is configured as a hydraulic continuously variable transmission, and the I transmission (6) has a low speed "standard" for use during work and a "standard" speed for use during non-work such as road driving for transportation. The auxiliary transmission (6) is configured to be manually switched to the high-speed side "driving mode" used.
By switching between "travel" and "normal" mode, the vehicle speed can be switched between high and low speeds without operating the main transmission (3).

The engine (E) is attached with a rotation speed sensor (S1) that detects its output rotation speed.

Further, the transmission section (5) includes a vehicle speed sensor (S) as a vehicle speed detection means for detecting the vehicle speed based on the output rotation speed of the auxiliary transmission (6) that is transmitted to the traveling device (4).
2) is provided. In other words, although not shown, the vehicle speed sensor (S2) is connected to the auxiliary transmission (6), which is a rotating body located on the lower transmission side than the main transmission (3) and the auxiliary transmission (6). The vehicle speed is detected based on the amount of rotation per unit time of the output shaft (6A) of the vehicle or the input shaft of the traveling device (4).

Then, the load state of the engine (E) is determined based on the information of the rotation speed sensor (S1), and if the engine load becomes greater than a set value, the vehicle speed sensor (S1) determines the load state of the engine (E).
2) as a control means for automatically decelerating the transmission (3) by an amount of deceleration determined according to the difference between the detected vehicle speed (V) and a preset target vehicle speed (ν.) to be decelerated; A control device (7) is provided.

In FIG. 1, (8) is the main gear shift lever for manually operating the main gearbox (3), and (9) is the main gear lever for manually operating the main gearbox (3).
3) as an operating actuator for automatically decelerating the motor, the electric motor is frictionally held with respect to the linkage mechanism (10) between the manual operating brake 8) and the main transmission (3). They are linked via a mechanism (11). In other words, the electric motor (9)
This allows the automatic gear shifting operation to be performed automatically while giving priority to the gear shifting operation performed by the driver. Further, (12) is a sub-shift lever (S) for manually operating the sub-transmission device (6).
3) is a switch-type sub-shift sensor as a shift state detection means for detecting the operation state of the sub-shift lever (12).

By the way, the rotational speed of the engine (E) is inversely proportional to the load, so that it decreases as the load becomes heavier. Therefore,
Basically, when the rotation speed detected by the rotation speed sensor (S1) becomes equal to or less than a set rotation speed corresponding to a set value for determining the magnitude of the engine load, the engine load is greater than the set value. This is done so that it can be determined that there is. In other words, the rotation speed sensor (S1) corresponds to the load detection means for detecting the engine load.

Then, the rotation speed (N) detected by the rotation speed sensor (S1) corresponds to the set rotation speed (N1
), the transmission (3) is automatically decelerated by the electric motor (8).
The overall engine load is maintained below the set value.

As shown in FIG. 3, the amount of deceleration of the transmission (3) is determined by the difference between the detected vehicle speed (V) detected by the vehicle speed sensor (S2) and a preset target vehicle speed to be decelerated. Please set it based on the following.

However, even if the amount of deceleration of the main transmission (3) is the same, the amount of deceleration relative to the actual vehicle speed is the same as that of the auxiliary transmission (6).
is larger in the case of ``Pa-run'' than in the case of ``Standard''.

Therefore, the value of the target vehicle speed (sh, ) should be set to a value on the higher speed side.

It should be noted that the detected vehicle speed (V) and the target vehicle speed (S, ゛) (V
The amount of deceleration to be set based on the difference between T).

T=to+, (v−v,') −−−−−−”Standard PaT
=kz, (V-Vz') --- "Traveling" However, in the above formula, + and kz are constants.

Next, the operation of the control device (7) will be explained based on the flowchart shown in FIG.

Based on the information of the rotation speed sensor (S3), it is determined whether the detected rotation speed (N) is below a preset set rotation speed (N1), and if it is below the set rotation speed (N3). This is to cause the system to determine that it is in an overload condition.

When it is determined that there is an overload state, the auxiliary transmission device (6
) is determined whether the operation state is "Standard Pa" or "Driving", the target vehicle speed is automatically changed according to the determination result, the corresponding deceleration amount is determined, and the Output processing for decelerating the main transmission (3) will be executed.

[Another example]

In the above embodiment, the shift state detection means for detecting the operating state of the sub-transmission device (6) is replaced with the sub-shift sensor (S□
), but the vehicle speed sensor (S2
) can also be configured to be indirectly determined based on the information.

First, a second example will be explained.

However, in this second embodiment and the third embodiment described later, the configuration of the unintended hardware that does not use the auxiliary shift sensor (S3) as a shift state detection means is different from the first embodiment. As such, the explanation will be omitted.

As shown in FIGS. 4 and 5, in the first embodiment, the value of the maximum vehicle speed when the auxiliary transmission (6) is switched to "standard" (target vehicle speed when Vυ is "driving") V2”
) By setting the value smaller than the value of the detected vehicle speed (
If V) is larger than the maximum vehicle speed value (V+) at the time of the "standard", the sub-transmission device (6) shifts to the high-speed "
' If the vehicle is running at the "normal" speed and the detected vehicle speed (V) is less than or equal to the maximum vehicle speed (v1), it can be determined that the vehicle is at the "standard" speed. In other words, the value of the maximum vehicle speed (v1)
corresponds to the set vehicle speed.

Incidentally, as shown in FIG. 5, the sub-transmission device (6) is
It may be possible to switch between three stages, or a plurality of three or more stages: high-speed "running", low-speed "standard", and "lowering", which is slower than the "standard" speed. , by setting the maximum vehicle speed value (ν3) of the vehicle lodging ゛′ to be smaller than the target vehicle speed ν′) at “Standard”.
Based on the detected vehicle speed ν), the operating state of the sub-transmission device (6) can be determined.

However, in the case of "lowering", the vehicle speed is originally low, so there is no risk of overloading.Therefore, automatic deceleration operation may not be performed.Next, regarding the third embodiment, explain.

In the second embodiment, the detected vehicle speed
The target vehicle speed for "driving"(vz') and the target vehicle speed for "standard" (
v, '), the auxiliary transmission (6
) is the same value both in "driving" and "standard", in this case, the sub-transmission device (6
) cannot be determined.

Therefore, as shown in FIG.
) becomes below the set rotation speed (N3) and an overload condition occurs, the current vehicle speed (v1) is read based on the information from the vehicle speed sensor (S2) and
During this period, the electric motor (8) for deceleration is driven. In other words, since the amount of deceleration is set as the drive time (T) of the electric motor (8), the drive time is set as the constant time (1).
By doing so, a state is established in which deceleration operation is performed with a constant initial deceleration amount.

After a certain period of time (1) has elapsed, the current vehicle speed (ν2
), the change in vehicle speed before and after the deceleration operation, that is, the amount of vehicle speed deceleration, is determined based on the formula below, and based on the magnitude of this value, it is determined whether the auxiliary transmission (6) is "traveling" on the high speed side or at low speed. This is to determine whether it is the "standard" of the other side.

In other words, the shift state detection means is configured to determine the shift state based on the amount of vehicle speed deceleration when the vehicle is decelerated by the initial 'M deceleration amount.

After determining the speed change state of the sub-transmission device (6), the electric motor (8)
From the value of the deceleration amount set as the output time to drive the
By outputting the time obtained by subtracting the predetermined time (1) as the latter deceleration amount, it is finally possible to perform deceleration operation with the deceleration amount corresponding to each of the "driving" and "product standards". -ing

Hereinafter, other embodiments of each of the other parts will be described.

In each of the above embodiments, the shift state of the sub-transmission device (6) is directly detected by the sensor (S3) or determined from the value of the detected vehicle speed (V). Even if the operation status of 3) is the same, the auxiliary transmission (6)
By utilizing the fact that when is on the high speed side, the detected vehicle speed (ν) is higher than when it is on the low speed side, the detected vehicle speed (
It is also possible to determine the gear change state of the auxiliary transmission (6) based on the operating state of the main transmission (3) and the operating state of the main transmission (3).

To explain, for example, the operating state of the main transmission (3) is configured to be detected as absolute position information by a potentiometer, etc., and the detected value and detected vehicle speed (V) are
The gear change state of the sub-transmission device (6) can be determined based on the magnitude of the ratio. Therefore, the specific configuration of the gear shift state detection means can be modified in various ways.

Furthermore, in each of the above embodiments, the engine load is expressed as engine (E).
Although the case where the detection is performed based on the rotational speed of the engine (E) has been exemplified, the detection may be performed based on, for example, fluctuations in the output torque of the engine (E), and the specific configuration of the load detection means can be changed in various ways.

Further, in each of the above embodiments, the vehicle speed detection means is connected to the traveling device (4).
), the case where the vehicle speed is detected based on the output rotation speed of the sub-transmission device (6) that drives the vehicle is illustrated, but for example,
The operation state of the main transmission (3) and the sub-transmission bag W (6) may be detected and converted into vehicle speed, and the specific speed or various changes can be made.

Further, in each of the above embodiments, the case where the deceleration amount is set as the operating time (T) of the electric motor (8) as an actuator for deceleration operation of the transmission (3) is exemplified, but for example, A sensor is provided that directly detects the operation position and operation amount of the transmission (3), and the target operation position is set by adding the deceleration amount to the current operation position, and the target deceleration amount is changed so that the deceleration operation is performed. It may be set as the actual operation amount of the device (3).

Further, in the above embodiment, the present invention is applied to a combine harvester, but the present invention can be applied to vehicle speed control devices for various work vehicles, and the specific configuration of each part can be modified in various ways.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the vehicle speed control device for a working vehicle according to the present invention, FIG. 1 is a block diagram of the control configuration, FIG. 2 is a flowchart of the control operation in the first embodiment, and FIG. 3 is the first implementation thereof. It is an explanatory view of the relationship between detected vehicle speed and target vehicle speed in an example. 4 to 6 are drawings showing another embodiment, in which the fourth part is a flowchart showing the processing in the second embodiment corresponding to the gear shift state detection means, and the fifth part is a flowchart showing the detected vehicle speed in the second embodiment. FIG. 6 is a flow chart showing the processing in the third embodiment. (S1) Load detection means, (s2) Old...
Vehicle speed detection means, (S3)...Shift state detection means, (E)...Engine, (3)...Main transmission, (6)...・Sub-transmission device, (7)...
...control means.

Claims (1)

[Claims] 1. Main transmission for traveling (3) and auxiliary transmission for traveling (
6) are connected in series to the engine (E), a load detection means (S_1) for detecting the load of the engine (E), a vehicle speed detection means (S_2) for detecting the vehicle speed, and the load detection means (S_1). Based on the information of the vehicle speed detection means (S_2), if the load becomes larger than the set value, the deceleration amount is calculated according to the difference between the detected vehicle speed and a preset target vehicle speed to be decelerated. A vehicle speed control device for a work vehicle, which is provided with a control means (7) for automatically decelerating the main transmission (3), and detects a shift state of the sub-transmission (6). Detection means (S_3) is provided, and the control means (7) is configured to control the target vehicle speed when the auxiliary transmission (6) is operated to the high speed side than when it is operated to the low speed side. so that is on the high speed side,
A vehicle speed control device for a work vehicle configured to automatically change the setting of the target vehicle speed based on information from the shift state detection means (S_3). 2. The vehicle speed control device for a work vehicle according to claim 1, wherein the shift state detection means (S_3) detects that when the engine load becomes higher than the set value, the detected vehicle speed is higher than the set vehicle speed. A vehicle speed control device for a work vehicle configured to determine that the vehicle speed is high if the vehicle speed is detected, and to determine the vehicle speed to be low if the detected vehicle speed is less than or equal to a set vehicle speed. 3. The vehicle speed control device for a work vehicle according to claim 1, wherein the vehicle speed detection means (S_2) is a rotational speed control device located on a lower transmission side than the main transmission (3) and the auxiliary transmission (6). The control means (7) is configured to detect the vehicle speed based on the amount of rotation of the body per unit time, and the control means (7) performs a deceleration operation by a preset initial deceleration amount, and then controls the speed change state detection means (S_3). The vehicle is configured to perform a deceleration operation by determining a later deceleration amount based on the detection information, and the shift state detection means (S_3) is configured to determine the shift state based on the amount of vehicle speed deceleration when a deceleration operation is performed using the initial deceleration amount. A vehicle speed control device for a work vehicle consisting of: