JPH01141260A - Speed change structure for working vehicle - Google Patents

Abstract

PURPOSE:To switch speed change smoothly and to shorten decelerating time by setting an intermediate speed change position through a decelerating position setting means corresponding to decelerating rate when decelerating position is skipped more than one stage. CONSTITUTION:When decelerating position is skipped more than one stage through a speed setter 14, control means C in a controller 13 determines an intermediate speed change position, i.e. a decelerated vehicle speed, at a time point when a time necessary for a speed change system for reaching to a transmitting state has elapsed based on a vehicle speed and a deceleration rate under a state where a travel system has reached to a non-drive state. If it is higher than a vehicle speed at a target speed change position, a decelerating position selecting means D brings a transmission 3 temporarily to an intermediate speed change position through a solenoid valve V and an actuator A then brings to a target speed change position. If the vehicle speed at the intermediate speed change position is lower than the vehicle speed at the target speed change position, the transmission 3 is brought directly to the target speed change position. In such a manner, speed change is performed smoothly and decelerating time can be shortened.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a transmission structure for a working vehicle, and more specifically, the present invention relates to a transmission structure for a working vehicle, and more specifically, the transmission is operated by the operation of an actuator, and the transmission is performed by jumping from a predetermined transmission position to an arbitrary transmission position. The present invention relates to a technology for automatically changing speeds using a speed change structure configured to be able to change speeds to a state in which the speed changes.

[Conventional technology]

Conventionally, as an automatic shift technology configured as described above, there is one disclosed in Japanese Patent Application Laid-Open No. 55-1229, and in this reference, an arbitrary shift position is selected by operating a switch, and, for example, If you attempt to shift to a jump state, such as when changing from 1st forward gear to 3rd forward gear, the automatic transmission system will change the gear in stages from 1st forward gear to 2nd forward gear and then to 3rd forward gear. It is configured.

[Problem that the invention seeks to solve]

However, when a shift is performed that skips the shift position as in the above reference, the shift to the increasing speed side is performed smoothly. When the load on the system is large, if you attempt to shift to the deceleration side by skipping one or more gear positions, the vehicle speed will be significantly reduced when the drive system reaches the non-drive state to perform the shift. During the gear shifting operation,
The vehicle speed may be lower than the speed of the intermediate gear.

Under such a situation where the vehicle speed decreases significantly, performing the gear shift in stages is likely to lead to the occurrence of swaying and rolling, and there is room for improvement.

An object of the present invention is to configure a transmission structure that makes it difficult to generate a shock as much as possible even when a shift that skips one or more gear positions in the direction of deceleration is selected in a situation where the vehicle speed significantly decreases. .

[Means for Solving the Problems] The present invention is characterized by: a gear-type transmission that is operated to change gears by actuating an actuator; a control means that operates the actuator to a target shift position in response to a selection signal from a speed setting device; Each sensor is provided to detect the ground running speed of the vehicle body, and when a shift that skips one or more shift positions in the deceleration direction is selected by the speed setting device, the traveling system is in a non-driving state in order to perform deceleration. The attenuation rate of the vehicle speed in the state in which the shift position is reached is determined by the signal from the sensor, and the vehicle speed after the activation time of the actuator required to reach the shift position from this non-driving state is determined by calculation, and the vehicle speed determined in this way is If the vehicle speed determined is higher than the target shift position, priority is given to the operation of the control means, and the gear shift is temporarily set to a shift position that substantially matches this vehicle speed; The present invention is comprised of a deceleration position selection means that allows the speed change setting to the target speed change position, and its functions and effects are as follows.

[For production]

If the above characteristics are configured as shown in FIG. 1, for example, when the speed setting device (14) is selected to skip one or more gear positions in the deceleration direction, the flowchart shown in FIG. (, calculate the vehicle speed when the driving system reaches the non-driving state to perform deceleration, and the reduced vehicle speed after the time required for the transmission system to reach the transmission state from the vehicle speed attenuation rate, and calculate this vehicle speed. is temporarily set as an intermediate shift position, and if the vehicle speed at this intermediate shift position is higher than the vehicle speed at the target shift position, the gear is first shifted to this intermediate shift position, then the gear is shifted to the target shift position, and the vehicle speed is If the vehicle speed at the target shift position is smaller than the vehicle speed at the target shift position, such as in a situation where the damping of

In other words, when a selection is made to skip one or more gear positions in the direction of deceleration, instead of always changing gears in stages,
Since the deceleration position setting means (D) sets the intermediate shift position according to the attenuation rate of the vehicle speed, the shift can be smoothly performed.

〔Effect of the invention〕

Therefore, even when a shift that skips one or more gear positions in the direction of deceleration is selected in a situation where the vehicle speed decreases significantly, such as in a paddy field, a shift structure has been constructed that does not easily cause sluggishness.

In particular, in the present invention, when the intermediate shift position is formed in a skip state, the deceleration time can be shortened compared to a structure in which deceleration is performed in stages.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figures 1 to 3 show the transmission system, speed change control system, etc. of an agricultural tractor as an example of a working vehicle. (2) to the mission case (3), and after the power transmitted to the mission case (3) is shifted inside the mission case (3), the front and rear wheels (4), (5), A transmission system is configured so that the transmission is transmitted to the PTO shaft (6), and the speed change for traveling is performed by electrical control.

That is, the power transmitted from the main clutch (2) to the transmission case (3) is transmitted via the input shaft (7) to the gear transmission mechanism (8) for the PTO shaft (6) and the main transmission for the traveling system ( 9), and this main transmission (9) has two hydraulic actuators (Av), (
A9) is configured to be shifted to four speeds by the operation of
This main transmission (9) is transmitted to a forward/reverse transmission (11) and a sub-transmission (12) through a hydraulic clutch (10).The forward/reverse transmission (11) is also connected to a hydraulic actuator (A,). The auxiliary transmission (12) is configured to be able to switch between two gears, front and rear, by the operation of the hydraulic actuator (Lx
), and the power from this sub-transmission device (12) is transmitted to the differential device (4a) for the front wheels (4) and the differential device (4a) for the rear wheels (5). 5
a).

In addition, when shifting, this transmission system first disengages and operates the hydraulic clutch (10), then operates the necessary hydraulic actuator (A), and then operates the hydraulic clutch (10).
The sequence of operations is determined so that the operation starts when the signal enters 0).

Furthermore, the four hydraulic actuators (A9).

(A9), (All), and (Act) operate with hydraulic oil supplied via a solenoid valve (V) that is controlled by a signal from a control means (13) incorporating a microprocessor (not shown). As shown in FIG. 2, a signal system is formed in the control means (13) to receive signals from a speed setting device (14) having a large number of push-operated switches (14a). ) includes a control means (C) for operating the hydraulic actuator (^) to a target shift position in response to a selection signal from the speed setting device (14), and a speed setting device (14).
When a shift that skips one or more shift positions in the deceleration direction is selected by the selection signal from 4), the control means (C
>, the hydraulic actuator (A9), (A
v) , (A t +) + (A t □), and a deceleration position selection means (D) that can operate , (A t +) + (A t □) is stored in a program state.

The traveling transmission system is also provided with a sensor (15) for detecting the ground running speed of the vehicle body from the rotational speed of the transmission shaft, and the automatic transmission system operates according to the flowchart shown in FIG.

In other words, when the gear shift position is selected by the speed setter (14), the gear shift direction is determined.III, #2. I13 step)
If the shift is in the direction of speed increase, it is determined whether it is a jump shift or not (4 steps).If the shift is a jump shift, the intermediate shift position is set in stages, and finally the target shift position is set. (115.116 steps).

Also, if it is determined in step #4 that only one gear is to be shifted, the target shift position is directly set (step #7).
Similarly, when the gear shift direction is neutral in step #3, the gear is directly set to the neutral position (heating step 8).

In addition, even if the gear shift direction is the deceleration direction in step #3, it is necessary to determine whether or not it is a jump shift (step 19).
If it is determined that the shift is to be performed by only one gear, the target shift position is directly set (steps of $10).

Then, when it is determined in step 9 that it is a jump shift, an intermediate shift position is determined, and after operations such as determining whether or not this intermediate shift position can be selected, the target shift position is set (step #11). ).

The 1110 steps of the 1110 step are collectively referred to as control means (C), and the 119 and 111 steps are collectively referred to as deceleration position selection means (D).The details of the operation of step #11 are as shown in the flowchart of FIG. be.

In other words, the operation of the intermediate position selection routine in step #11 is to disengage and operate the hydraulic clutch (lO) and operate the hydraulic actuator (A) in the neutral direction (lt21).
．． Step #22), Next, based on the signal from the sensor (15), calculate the vehicle speed of the vehicle that has reached the non-driving state and the attenuation rate of the vehicle speed in this state (+
Based on this vehicle speed and damping rate, calculate and estimate the vehicle speed after the elapse of the time required for the transmission system to reach the transmission state by operating the hydraulic actuator (A) (Step 123), and approximately match this vehicle speed. Find the shift position (#25 step).

This shift position is called the intermediate shift position. For example, when the load on the driving system is large, such as when working in rice fields, the vehicle speed attenuation is extremely large (the estimated vehicle speed or the target shift position (selected with the speed setting device) is Since the vehicle speed may be lower than the vehicle speed at the gear shift position), it is necessary to determine this by calculation.1126.1
Step 127), if the vehicle speed is not lower than the target shift position, set the vehicle speed to the intermediate shift position (Step 28), and engage the hydraulic clutch (IO) to operate #2.
9 steps), set time weight #30 steps)
Furthermore, by repeating the operation from step 1121, smooth deceleration is achieved.

or,! 21. In step 1127, if the intermediate shift position is lower than or coincides with the target shift position, the hydraulic actuator (A) corresponding to the target shift position is actuated (#31 step), and the hydraulic clutch (10) is activated. By turning on and operating (#32 step), the gear shifting operation is completed.

[Another example]

In addition to the embodiments described above, the present invention may also be configured such that the control means and the deceleration position selection means are configured as hardware using logic gates, comparators, etc., the transmission device may be configured as a hydraulic clutch type transmission system, or , the present invention may be implemented in various ways, such as by applying it to a transport vehicle.

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 transmission structure for a working vehicle according to the present invention, and FIG. 1 is a block diagram showing the configuration of the transmission structure, FIG. 2 is a perspective view showing the arrangement of the push operation switch of the vehicle speed setting device, and FIG. 3
This figure is a diagram of the transmission system of an agricultural tractor, FIG. 4 is a flowchart showing an intermediate shift position control routine, and FIG. 5 is a flowchart showing an automatic shift routine. (14)... Speed setting device, (15)...
・Sensor, (A)... Actuator, (C)
...control means, (D) ...deceleration position selection means.

Claims (1)

[Claims] A gear type transmission device that is operated to change speed by actuation of an actuator (A), a control means (C) that operates the actuator (A) to a target shift position in response to a selection signal from a speed setting device (14), and ground running of the vehicle body. Each sensor (15) that detects the speed is provided, and when the speed setting device (14) selects a shift that skips one or more shift positions in the deceleration direction, the traveling system is disabled to perform deceleration. The attenuation rate of the vehicle speed when the drive state is reached is determined by the signal from the sensor (15), and the vehicle speed after the actuation time of the actuator (A) required to reach the shift position from the non-drive state is determined by calculation. , and if the vehicle speed determined in this way is higher than the target shift position, priority is given to the operation of the control means (C), and the shift is once set to a shift position that substantially matches this vehicle speed, and then the determined vehicle speed is set. A shift structure for a work vehicle, comprising a deceleration position selection means (D) that allows a shift setting to a target shift position if the vehicle speed is lower than the target shift position.