JPH0415367A - Vehicle speed controller for working vehicle - Google Patents

Abstract

PURPOSE:To carry out the proper deceleration by operating an actuator with a previously set operation quantity when the detected car speed is the speed for the operation of an elastic versatility part, while obtaining the operation quantity from the difference between the detected car speed and the target car speed when the detected car speed is not sufficient for the operation of the elastic versatility part. CONSTITUTION:It can be judged from the value of the detected car speed if a speed change device 3 reaches the limit on the high speed side of the speed change range or not. Accordingly, it can be judged from the detected car speed if the speed change range reaches the limit on the high speed range, and an elastic versatility part 11 is in operation or not. Accordingly, when the elastic versatility part 11 is in operation, a speed change actuator 8 is operated with the previously set operation quantity, and the actual deceleration quantity is not proportional to the operation quantity, and deceleration is carried out surely, and the load can be lightened. When the detected car speed is the speed which does not operate the elastic versatility part 11, the operation quantity of the actuator 8 is obtained according to the difference between the detected car speed and the target car speed for deceleration, similarly as conventional.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a mechanism for linking a speed change operation tool that can be held at any position within a speed change operation range and a continuously variable transmission for traveling.
An elastic flexible portion is provided that allows the shift operating tool to shift to the high speed side when the continuously variable transmission is at the high speed limit of the speed change range, and the shift actuator is located at the higher end of the elastic flexible portion than the elastic flexible portion. A load detection means for detecting engine load, a vehicle speed detection means for detecting vehicle speed, and a load detection means for detecting the engine load, which is provided to operate a member on the gear shift operation tool side, and a vehicle speed detection means for detecting the vehicle speed; When the load becomes larger than the set value, the transmission actuator is operated to automatically decelerate the transmission by an amount of operation 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 work vehicle that is provided with a control means for operation.

[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 in accordance with 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. Therefore, although transmissions are designed to be able to automatically shift gears using an actuator, work vehicles usually have a gearshift operation that can be held at any position within the shift operation range so that it can also be operated manually. The gear is connected to the transmission.

However, since it is difficult to completely match the operating range of the gear shift operating tool and the operating range of the transmission,
An elastic flexible portion is provided in the linkage mechanism between the speed change operating tool and the transmission device to allow the speed change operating tool to shift to the high speed side even when the speed change device is at the high speed side limit of the speed change range.

[Problem to be solved by the invention] During the linkage mechanism between the speed change operation tool and the continuously variable transmission for driving,
If an elastic flexibility portion is provided that allows the shift operating tool to shift to the high speed side when the continuously variable transmission is at the high speed limit of the speed change range, in a state where the elastic flexibility portion is activated, Even if the shift actuator is operated at an amount corresponding to the difference between the detected vehicle speed and the target vehicle speed to be decelerated,
There is a possibility that the speed cannot actually be decelerated.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an elastic flexible portion that allows the shift operation tool to shift to the high speed side when the speed change range of the transmission device is at the high speed side limit. The purpose is to be able to accurately decelerate even when the device is in operation.

[Means to solve the problem]

In the vehicle speed control device for a work vehicle according to the present invention, in a linkage mechanism between a speed change operation tool that can be held at any position within a speed change operation range and a continuously variable transmission for traveling, the continuously variable transmission is connected to a speed change range. An elastic flexible portion is provided that allows the shift operating tool to shift to the high speed side -1 in a state where the shift operating tool is at the high speed side limit of a load detection means for detecting engine load; a vehicle speed detection means for detecting vehicle speed; control means for automatically decelerating the transmission by operating the transmission actuator with an actuation amount determined according to the difference between the detected vehicle speed and a preset target vehicle speed to be decelerated; The features and configuration are as follows.

That is, the control means operates the actuator by a preset amount of operation when the detected vehicle speed is the speed at which the elastic flexibility section is actuated when the engine load becomes higher than a set value. and when the detected vehicle speed is a speed at which the elastic flexibility section is not actuated, the actuation amount of the actuator is determined according to the difference between the detected vehicle speed and the target vehicle speed. be.

[Operation] Whether or not the transmission has reached the high speed limit of its transmission range can be determined from the value of the detected vehicle speed.

Therefore, it can be determined based on the detected vehicle speed whether or not the speed change range has reached the high speed limit and the elastic flexibility section is operating.

Therefore, when the elastic flexible section is operating, by operating the shift actuator at a preset operating amount, the actual deceleration amount will not be proportional to the operating amount, but it will ensure deceleration. This makes it possible to reduce the load. Incidentally, when the detected vehicle speed is a speed at which the elastic flexibility section is not activated, the actuation amount of the braking actuator is determined in accordance with the difference between the detected vehicle speed and the target vehicle speed to be decelerated, as in the conventional case.

[Effects of the Invention] As a result, it is now possible to accurately decelerate even when the elastic flexible portion provided in the linkage mechanism between the transmission and the speed change operating tool is in an operating state.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, an 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 Figure 1, the output of the engine (E) is a threshing machine as a working device! (1) and the reaping section (2), and is also transmitted to a hydraulic continuously variable transmission (3) for traveling, and the output of the transmission (3) is transmitted to the crawler traveling device (4). The power is transmitted to the transmission section (5). However, although not described in detail, transmission between each part is performed by a heald or the like.

and a rotation speed sensor (S+) that detects the rotation speed of the engine (E), and a vehicle speed sensor that detects the vehicle speed based on the output rotation speed of the transmission (3) that is transmitted to the transmission section (4). The load state of the engine (E) is determined based on information from a vehicle speed sensor (S2) as a means, the rotation speed sensor (s1), and the vehicle speed sensor (S2), and the engine load is larger than a set value. In this case, the detected vehicle speed (V) and the preset target vehicle speed (V) to be decelerated.

), the transmission W(3
) as a control device that automatically decelerates the
6) is provided.

The transmission device (3) is configured so that the electric motor (8) can perform a speed change operation using either a manually operated speed change lever (7) as a speed change operation tool or an electric motor (8) as a speed change actuator. ) is the gear shift lever (7)
and a rod (9) serving as a linkage mechanism with the transmission (3).
) via a friction type retention mechanism (10). In other words, the electric motor (
8), the gear shifting operation can be performed automatically without giving priority to the gear shifting operation.

By using the friction type holding mechanism (10), the shift lever (7) is held at any position within the shift operation range.

Also, in the linkage mechanism between the speed change lever (7) and the speed change device (3), the speed change lever (7) may
An elastic flexible portion (11) is provided that allows the shift to a high speed side, and the shift lever (7) is moved to an upper operating end (B) which is a higher speed side than the high speed limit (A) of the shift range. It can be operated. In addition, in Figure 1, (12)
is the guy F plate of the speed change lever (7).

To further explain the elastic flexible portion (11), the second
As shown in the figure, a cylinder (14) containing an initially compressed coil spring (13) is interposed in the middle portion of the rod (9) serving as the linkage mechanism. However, the rod (9) is divided into a cylinder-side rod (9a) connected to the speed change lever (7) and a piston-side rod (9b) connected to the speed change device (3). It is divided and connected to the cylinder (14) with the piston-side rod (9b) housed therein.

Said coil ha? , (13) is weaker than the holding force of the speed change lever (7) by the friction type holding mechanism (10), and the pressure of the speed change device (3) is lower than the high speed limit (A). It is set larger than the operating force required when changing gears at low speeds.

That is, at a speed lower than the high speed limit (A) of the speed change range of the transmission (3), the coil spring (I3) is not compressed, and the rod (9a) on the cylinder side and the rod (9a) on the piston side ( 9b) is configured to act as a rigid body without being shortened, and the elastic flexible portion (11) is in a non-operating state. Thus, while the operating force of the shift lever (7) can be transmitted to the shift device (3), even after the shift device (3) reaches the high speed limit (A), the shift lever ( 7) can be operated further to the high speed side until it reaches its upper operating end (B).

Therefore, as shown in FIG. 4, the gear shift lever (7)
While the operating position of the shift lever (7) is between the high speed limit (A) and the upper operating end (B), the elastic flexible portion (11) operates to absorb the operation of the shift lever (7), and the shift lever (7) is operated. The transmission (3) is maintained at the high speed limit (A) of the speed change range, and the vehicle speed remains unchanged at the maximum vehicle speed (V1) that can be changed.

In the following description, the operating position of the gear shift lever (7) will vary from the high-speed limit (A) to the upper operating end (B).
Control in a state between the two is referred to as mode 2, and control in a state in which the operating position of the shift lever (7) is on the lower speed side than the high speed limit (A) is referred to as mode 1.
It is called.

Next, engine load detection will be explained.

The rotation speed of the engine (E) is inversely proportional to the load, as the load becomes heavier.
The rotation speed detected by the rotation speed sensor (S1) (
When N) becomes lower than a set rotational speed (N, ) corresponding to a set value for determining the magnitude of the engine load, it is determined that the engine load is greater than the set value. In other words, the rotation speed sensor (S,) corresponds to load detection means for detecting the engine load.

When the engine load becomes larger than a set value and the engine speed (N) falls below the set speed (N+), the electric motor (8) operates to decelerate the transmission (3). By doing so, the running load is directly reduced, and the working load is indirectly reduced by reducing the working speed, so that the engine load is maintained below the set value.

In addition, in this embodiment, the operating amount of the electric motor (8) is
- times of deceleration operation to continuously drive the electric motor (8), that is, the actuator operation time (T) is set.

Then, as shown in the formula below, the operating time (T) is
If the vehicle speed detected by the vehicle speed sensor (S2) is fast, the deceleration is set according to the detected vehicle speed (V) and is calculated according to the difference between the target vehicle speed (V+') (see Fig. 4). It's Nishide.

′l”=k・(V-v,') In the above formula, k is a constant.

However, as mentioned above, when the speed change lever (7) is between the high speed limit (A) and the upper operating end (B),
Even when the electric motor (8) is operated, the elastic flexible portion (11
) is in effect, the gear cannot be changed.

Therefore, in this case, by operating the electric motor (8) at a preset constant operating amount (T = '), the speed change lever (7) is moved beyond the high speed limit (B). The elastic flexible portion (11) is returned to the non-operating state by operating the vehicle toward a low speed side, and the vehicle is then operated close to the target vehicle speed (V, ). The above-mentioned constant operation amount is generally set as an amount that allows the gear shift to the target vehicle speed (V1) even if the gear shift lever (7) has reached the high speed limit (B). When the shift lever (7) is located at the center position between B) and the high speed limit (8), set it as the amount by which the gear can be shifted to the target vehicle speed (V1), etc.
Various changes can be made.

Hereinafter, the operation of the control device (6) will be explained based on flowchart 1 shown in FIG.

When the control operation is started, it is determined whether the engine load is greater than the set value based on whether the engine speed (N) has become equal to or less than the set speed (+J,). .

When the engine load exceeds the set value and is in an overload state, the electric motor (8)
is activated to automatically perform a deceleration operation, but only when the detected vehicle speed (V) is in mode 1, which is between the target vehicle speed (Vi') and the maximum vehicle speed (V1). , the operating amount of the electric motor (8) is determined by the above formula as a value corresponding to the difference between the detected vehicle speed (V) and the target vehicle speed (V + '), and the detected vehicle speed (V)
is the maximum vehicle speed (V,) or more, the electric motor (8) is operated by the constant operating amount (T=
It is made to operate with ').

[Another example]

By the way, if the engine speed (N) decreases as the load increases, the actual vehicle speed will decrease even if the transmission (3) is not operated.

When the actual vehicle speed decreases, the detected vehicle speed (V) will be detected as a vehicle speed lower than the vehicle speed corresponding to the current shift operation state of the transmission (3), and as a result, the target vehicle speed (V+") There is a risk that the difference between the speed and speed will become smaller and the deceleration amount will be insufficient.

Therefore, the operating time (T) of the electric motor (8) as the operating amount of the speed change actuator in mode 1
If the value of is determined based on the ratio of the detected vehicle speed (V) and the engine rotation speed (N) as shown in the following formula, the detected vehicle speed (V
) decreases, the amount of deceleration can be prevented from becoming insufficient.

Further, in the above embodiment, the engine load is detected based on the rotational speed of the engine (E), but it may also be detected based on, for example, fluctuations in the output torque of the engine (E). Often, the specific configuration of the load detection means can be modified in various ways.

Further, in the above embodiment, the case where the present invention is applied to the Conhi>02 was illustrated, but the present invention can be applied to vehicle speed control devices of various types of work vehicles. can.

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 an enlarged sectional view of the elastic flexible part, and FIG. 3 is a flowchart of the control operation.
FIG. 4 is an explanatory diagram of the relationship between the vehicle speed and the operating position of the gear shift operating tool. (S1)...Load detection means, (S2)...
...Vehicle speed detection means, (V)...Detection vehicle speed, (V
+')...Target vehicle speed, (3)...Continuously variable transmission, (6)...Control means, (7)...
...speed change operation tool 1, (8) ... speed change actuator, (11) ... elastic flexibility part. Figure 1

Claims (1)

[Scope of Claims] The continuously variable transmission (3) is connected to the continuously variable transmission (3) for traveling and the gear change operating tool (7) which can be held at any position within the gear change operation range. ) is at the high speed limit of the speed change range, an elastic flexible portion (11) is provided that allows the speed change operating tool (7) to shift to the high speed side, and the speed change actuator (8) provided to operate a member closer to the speed change operating tool than the flexible portion (11);
A load detection means (S_1) detects the engine load, a vehicle speed detection means (S_2) detects the vehicle speed, and the engine load is determined based on the information of the load detection means (S_1) and the vehicle speed detection means (S_2). If the speed is higher than the set value, the shift actuator (8) is actuated with an actuation amount determined according to the difference between the detected vehicle speed (V) and a preset target vehicle speed (V_1') to be decelerated. A vehicle speed control device for a work vehicle, comprising: a control means (6) for automatically decelerating the transmission (3) when the engine load is lower than a set value. If the detected vehicle speed (V) is a speed at which the elastic flexible portion (11) is actuated, the actuator (8) is actuated by a preset actuation amount, and the detected vehicle speed is When the vehicle speed (V) is
), the operating amount of the actuator (8) is determined according to the difference between the detected vehicle speed (V) and the target vehicle speed (V_1'). Vehicle speed control device.