JP2020098008A - Tractor - Google Patents

Abstract

To provide a tractor capable of reducing the number of components by eliminating a lever position detection switch which detects operation positions of main transmission shift lever and an auxiliary transmission shift lever.SOLUTION: A tractor T comprises: a control device 28 which moves a traveling machine body 1 in a forward or reverse direction through pressure control of a forward travel hydraulic clutch 12 or a reverse travel hydraulic clutch 13 according to operation of a forward-and-reverse travel switching lever 20; a forward-and-reverse operation detection switch 29 which detects the operation of the forward-and-reverse travel switching lever 20; a neutral operation detection switch 30; a reverse operation detection switch 31; and a speed sensor 35 which detects a speed of the traveling machine body 1. When the forward-and-reverse travel switching lever 20 undergoes travel direction switching operation, the control device 28 performs the pressure control of the forward travel hydraulic clutch 12 or the reverse travel hydraulic clutch 13 with a predetermined boosting pattern regardless of shift stages of a main transmission mechanism 9 and an auxiliary transmission mechanism 11.SELECTED DRAWING: Figure 5

Description

The present invention relates to a tractor including a forward hydraulic clutch and a reverse hydraulic clutch.

Control for moving forward or backward of the traveling machine by boosting the forward hydraulic clutch and reverse hydraulic clutch for switching between forward and backward traveling of the traveling machine body and boosting control of the forward traveling hydraulic clutch and reverse hydraulic clutch according to the operation of the forward/reverse traveling switching operation tool. A tractor including a device is known (for example, see Patent Documents 1 and 2).

Japanese Patent No. 4098903 JP-A-2002-81539

However, the tractors described in Patent Documents 1 and 2 include a main gear shift detecting unit that detects the operating position of the main gear shift lever and an auxiliary gear shift detecting unit that detects the operating position of the sub gear shift lever, and the control device is Since the pressure rising patterns of the forward hydraulic clutch and the reverse hydraulic clutch are changed according to the operation positions of the main shift lever and the sub shift lever, not only the number of detection components such as the lever position detection switch increase but also the control becomes complicated. There was a risk of becoming.

The present invention has been made in view of the above circumstances in order to solve these problems. The invention of claim 1 shifts the traveling machine body and the traveling power of the traveling machine body in stages. And a forward hydraulic clutch for switching between forward and backward travel of the traveling machine body, and a reverse hydraulic clutch for controlling the pressure increase of the forward hydraulic clutch or the reverse hydraulic clutch according to the operation of the forward/reverse switching operation tool. A forward/backward movement detecting means for detecting an operation of the forward/backward movement switching operation tool, and a vehicle speed detecting means for detecting a vehicle speed of the traveling body. When the forward/reverse switching operation tool is operated to move forward or backward, the control device boosts the forward hydraulic clutch or the reverse hydraulic clutch to a predetermined pressure regardless of the shift speed of the traveling transmission mechanism. If the acceleration of the traveling machine body is determined based on the clutch connection control means for controlling the pressure increase in a pattern and the detected vehicle speed during the pressure increase control, and it is determined that the acceleration has changed in the increasing direction, the forward hydraulic clutch or the forward hydraulic clutch is used. Pressure increase suppressing means for suppressing an increase in pressure of the reverse hydraulic clutch.
The invention according to claim 2 is the tractor according to claim 1, wherein the control device determines that the vehicle speed of the traveling machine body has reached a target speed based on the detected vehicle speed during the boost control. It is characterized in that it further comprises a pressure increase promoting means for promoting pressure increase of the forward hydraulic clutch or the reverse hydraulic clutch.
Further, the invention of claim 3 is the tractor according to claim 2, wherein when the boosting acceleration means determines that the vehicle speed of the traveling machine body is stable based on the detected vehicle speed during the boosting control, It is characterized in that it is determined that the vehicle speed of the traveling body has reached a target speed.

According to the invention of claim 1, when the forward/reverse switching operation tool is operated to move forward or backward, the control device presses the forward hydraulic clutch or the reverse hydraulic clutch to a predetermined pressure regardless of the shift speed of the traveling transmission mechanism. Since the clutch connection control means for controlling the pressure increase by the pattern is provided, the lever position detection switch for detecting the operation position of the main speed change lever or the auxiliary speed change lever is not required, so that the number of parts can be reduced and the control can be simplified. Further, the control device determines the acceleration of the traveling machine body based on the detected vehicle speed during the boost control, and when it determines that the acceleration has changed in the increasing direction, suppresses the boost of the forward hydraulic clutch or the reverse hydraulic clutch. Since the pressurization suppressing means is provided, it is possible to prevent the traveling body from suddenly starting due to excessive pressure.
Further, according to the invention of claim 2, when the control device determines that the vehicle speed of the traveling machine body has reached the target speed based on the detected vehicle speed during the boost control, the control device boosts the forward hydraulic clutch or the reverse hydraulic clutch. Since the boosting promotion means for promoting the boosting is provided, not only the time required for boosting control can be shortened, but also the vehicle speed can be prevented from dropping due to the load after reaching the target speed.
Further, according to the invention of claim 3, when the boosting promoting means determines that the vehicle speed of the traveling machine body is stable based on the detected vehicle speed during the boosting control, it determines that the vehicle speed of the traveling machine body has reached the target speed. Therefore, the arrival at the target speed can be determined without calculating the target speed based on the operation positions of the main speed change lever and the auxiliary speed change lever.

It is a side view of the tractor concerning one embodiment of the present invention. It is a block diagram showing a traveling power transmission path. It is the perspective view which looked at the operation part from the upper part. It is a block diagram which shows the input/output of a control part. It is explanatory drawing of a clutch connection control means. It is explanatory drawing of a pressure|voltage rise suppression means, (a) is explanatory drawing which shows the case without pressure increase suppression, (b) is explanatory drawing which shows the case with pressure increase suppression. It is explanatory drawing of a pressure|voltage rise promotion means. It is a flow chart which shows a processing procedure of clutch connection control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a traveling machine body of a tractor T. The traveling machine body 1 includes an engine 2 (see FIG. 2) mounted on a front portion of the machine body, a transmission case 3 for changing power of the engine 2, and a transmission. A front wheel 4 and a rear wheel 5 which are rotationally driven by the traveling power supplied from the case 3, a work machine connecting portion 6 which connects a work machine (not shown) so as to be able to move up and down, and a driving portion 7 on which a worker rides. ..

As shown in FIG. 2, in addition to the main clutch mechanism 8, a transmission mechanism such as a main transmission mechanism 9, a forward/reverse transmission mechanism 10, and an auxiliary transmission mechanism 11 is provided in the transmission case 3. The forward-reverse speed change mechanism 10 includes a forward hydraulic clutch 12 and a reverse hydraulic clutch 13 that switch between forward and backward movements of the traveling vehicle body 1. It is switched between a forward drive state in which the hydraulic oil clutch 12 is connected and the reverse hydraulic clutch 13 is disconnected, and a reverse drive state in which the forward hydraulic clutch 12 is disconnected and the reverse hydraulic clutch 13 is connected.

The forward hydraulic clutch 12 and the reverse hydraulic clutch 13 are connected/disconnected according to the operation of the forward hydraulic valve 14 (see FIG. 4) and the reverse hydraulic valve 15 (see FIG. 4), which are proportional pressure reducing valves, respectively. It

As shown in FIG. 3, in addition to a driver's seat 16 on which a worker sits, a steering wheel 17 for steering the front wheels 4, a main speed change lever 18 for operating the main speed change mechanism 9, and an auxiliary speed change mechanism 11 are provided in the driver 7. An auxiliary shift lever 19 to be operated, a forward/reverse switching lever 20 (forward/reverse switching operation tool) to operate the forward/reverse shifting mechanism 10, a clutch pedal 21 to operate the main clutch mechanism 8, and left and right brake mechanisms (not shown) are individually provided. The left and right brake pedals 22 and 23, the connecting operation tool 24 that connects the left and right brake pedals 22 and 23, the parking brake lever 25 that holds the brake pedals 22 and 23 in the depressed position, and various other tools. A monitor panel 26 for displaying the status is provided.

As shown in FIG. 4, the traveling machine body 1 is provided with a control device 28 that performs forward/reverse switching control. On the input side of the control device 28, a forward operation detection switch 29 (forward/reverse operation detection means) for detecting a forward operation of the forward/reverse switching lever 20 and a neutral operation detection switch 30 for detecting a neutral operation of the forward/reverse switching lever 20. (Forward/reverse operation detecting means), a reverse operation detecting switch 31 (forward/reverse operation detecting means) for detecting a reverse operation of the forward/reverse switching lever 20, and a parking brake switch 32 for detecting an entering operation of the parking brake lever 25, An oil temperature sensor 33 that detects the oil temperature of hydraulic oil that operates the forward hydraulic clutch 12 and the reverse hydraulic clutch 13, an engine rotation sensor 34 that detects the rotation of the engine 2, and a vehicle speed that detects the vehicle speed of the traveling machine body 1. While the sensor 35 (vehicle speed detecting means) is connected to the output side of the control device 28, the forward hydraulic valve 14 and the reverse hydraulic valve 15 are connected.

The control device 28 has a functional configuration realized by the cooperation of hardware and software, and when the forward/reverse switching lever 20 is operated to move forward or backward, the gear position of the main transmission mechanism 9 or the auxiliary transmission mechanism 11 is changed. Regardless of this, the clutch connection control means for boosting control of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 in a predetermined boosting pattern, and the acceleration of the traveling machine body 1 are determined based on the detected vehicle speed during the boosting control, and the acceleration is determined. If it is determined that the vehicle speed has changed in the increasing direction, the vehicle speed of the traveling machine body 1 reaches the target speed on the basis of the boost suppressing means for suppressing the boost of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 and the detected vehicle speed during the boost control. If it is determined that the pressure has been increased, the pressure increase promoting unit that accelerates the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is provided.

As shown in FIG. 5, in the predetermined pressurization pattern used by the clutch connection control means, the forward hydraulic clutch 12 or the reverse hydraulic clutch 12 to be connected is filled with hydraulic oil at a predetermined pressure for a predetermined time. After the process and the oil filling process, the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 to be connected is filled with hydraulic oil while increasing the pressure at a predetermined first rising inclination, and a meat process. After completion of the above, a step of increasing the pressure of the hydraulic oil for forward movement 12 or the hydraulic clutch for reverse movement 13 to be connected while filling the hydraulic oil while increasing the pressure at a predetermined second rising inclination is included.

The clutch connection control means fills the hydraulic oil until just before the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 meets (starts clutch connection) in the oil filling process, and in the meet process, the forward hydraulic clutch 12 or the reverse hydraulic clutch. Meet 13 The first ascending slope and the hydraulic oil filling time in the meet process cover the shift load from the lowest shift stage (SL) to the highest shift stage (H) of the main transmission mechanism 9 and the auxiliary transmission mechanism 11, and which shift It is set so that a large shift shock does not occur even in a gear. After the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 has met, the clutch connection control means fills the hydraulic oil while increasing the pressure at a predetermined second rising inclination in the step-up process, thereby advancing the forward hydraulic clutch. 12 or the reverse hydraulic clutch 13 is shifted to a stable connected state. According to such a clutch connection control means, not only the lever position detection switch for detecting the operation position of the main speed change lever 18 and the auxiliary speed change lever 19 is not required, but the number of parts can be reduced and the control can be simplified.

As shown in (a) of FIG. 6, when the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is connected in a predetermined pressure increase pattern regardless of the traveling gear, the pressure increase after clutch meet may be excessive depending on the traveling gear. Therefore, a phenomenon in which the traveling vehicle body 1 rapidly accelerates may occur. As shown in (b) of FIG. 6, in order to avoid such a sudden acceleration phenomenon, the boost suppressing means determines the acceleration of the traveling vehicle body 1 based on the detected vehicle speed during the boosting process, and the acceleration increases. When it is determined that the hydraulic pressure has changed in the direction, the second rising inclination is reduced to suppress the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13. With such a boost suppressing means, it is possible to prevent the traveling vehicle body 1 from suddenly starting due to excessive clutch boosting. In the present embodiment, the boosting suppression process according to the increase in acceleration is executed only during the boosting step, but even during the meeting step, the acceleration of the traveling machine body 1 is determined based on the detected vehicle speed, and the acceleration When it is determined that has increased in the increasing direction, the first rising inclination may be reduced to suppress the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13.

On the other hand, as shown in FIG. 7, when the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is connected in a predetermined pressure increase pattern regardless of the traveling gear, the pressure increase after the clutch meet is insufficient depending on the traveling gear, and the vehicle travels. Even after the aircraft 1 reaches the target speed, the clutch engagement may not be completed for a long time. In order to avoid such a phenomenon, the pressure boosting means increases the second ascending slope by increasing the second ascending slope when it is determined that the vehicle speed of the traveling vehicle body 1 has reached the target speed based on the detected vehicle speed during the pressure boosting process. The pressurization of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is promoted. According to such boosting means, not only the time required for the boosting step can be shortened but also the vehicle speed can be prevented from dropping due to the load after reaching the target speed.

Further, the booster accelerating means determines that the vehicle speed of the traveling vehicle body 1 has reached the target speed when determining that the vehicle speed of the traveling vehicle body 1 is stable based on the detected vehicle speed during the boosting process. Specifically, the rate of change of the vehicle speed is detected, and when the rate of change becomes equal to or less than a predetermined value, it is determined that the vehicle speed is stable and that the vehicle speed has reached the target speed. According to such a boost promoting means, it is possible to determine whether the target speed is reached without calculating the target speed based on the operation positions of the main speed change lever 18 and the auxiliary speed change lever 19.

Next, clutch connection control including the processing procedures of the clutch connection control means, the pressure increase suppression means, and the pressure increase promotion means will be described with reference to FIG.

As shown in FIG. 8, in the clutch connection control, the control device 28 first determines the forward movement operation or the backward movement operation of the forward/reverse movement switching lever 20 (S1). The process proceeds to an oil filling step of filling the hydraulic clutch 12 or the reverse hydraulic clutch 12 with hydraulic oil at a predetermined pressure for a predetermined time (S2).

The control device 28 determines the completion of the oil filling process (elapse of a predetermined time) while executing the oil filling process (S3), and if the result of this determination is YES, the forward hydraulic clutch 12 to be connected or the reverse hydraulic clutch The hydraulic clutch 13 is shifted to a meet process of filling hydraulic oil while increasing the pressure at a predetermined first rising inclination (S4).

The control device 28 determines the completion of the meet process (elapse of a predetermined time) while executing the meet process (S5), and if the result of this determination is YES, the forward hydraulic clutch 12 or the reverse hydraulic clutch to be connected. With respect to No. 13, the process proceeds to the pressurization process of filling the hydraulic oil while increasing the pressure at the predetermined second rising inclination (S6).

While executing the boosting process, the control device 28 determines that the acceleration is increased (S7), the target speed is reached (S9), and the boosting process is completed (S11: the target current value is reached), and the acceleration is increased. When it is determined that there is a tendency, the second rising inclination is reduced to suppress the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 (S8), and when it is determined that the target speed is reached, By increasing the second rising inclination, the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is promoted (S10), and when it is determined that the pressure increasing process is completed, the present clutch connection control is ended.

According to the present embodiment configured as described above, the traveling machine body 1, the main transmission mechanism 9 and the sub transmission mechanism 11 that gradually change the traveling power of the traveling machine body 1, and the forward movement that switches the traveling machine body 1 between forward and backward movements. A hydraulic pressure clutch 12 and a reverse hydraulic clutch 13, and a control device 28 for increasing the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 according to the operation of the forward/reverse switching lever 20 to move the traveling machine body 1 forward or backward. A forward operation detection switch 29 for detecting the operation of the forward/reverse switching lever 20, a neutral operation detection switch 30 and a reverse operation detection switch 31, and a vehicle speed sensor 35 for detecting the vehicle speed of the traveling machine body 1. When the forward/reverse switching lever 20 is operated to move forward or backward, the control device 28 controls the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 regardless of the gear positions of the main transmission mechanism 9 and the auxiliary transmission mechanism 11. Since the clutch connection control means for controlling the pressure increase in a predetermined pressure increase pattern is provided, not only the lever position detection switch for detecting the operation position of the main speed change lever 18 and the auxiliary speed change lever 19 is not required, but the number of parts can be reduced and the control can be performed. Can be simplified.

In addition, the control device 28 determines the acceleration of the traveling machine body 1 based on the detected vehicle speed during the boost control, and when it determines that the acceleration has changed in the increasing direction, the forward movement hydraulic clutch 12 or the reverse movement hydraulic clutch 13 is detected. Since the boost suppressing means for suppressing the boost is provided, it is possible to prevent the traveling vehicle body 1 from suddenly starting due to excessive pressure.

In addition, when the control device 28 determines that the vehicle speed of the traveling vehicle body 1 has reached the target speed based on the detected vehicle speed during the boost control, the control device 28 promotes the boost of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13. Since the means is provided, not only the time required for boosting control can be shortened but also the vehicle speed can be prevented from dropping due to the load after reaching the target speed.

Further, the pressure boosting means determines that the vehicle speed of the traveling vehicle body 1 has reached the target speed when it determines that the vehicle speed of the traveling vehicle body 1 is stable based on the detected vehicle speed during the pressure boosting control. The arrival at the target speed can be determined without calculating the target speed based on the operation position of the auxiliary transmission lever 19.

T tractor 1 traveling machine body 9 main speed change mechanism 10 forward and backward speed change mechanism 11 auxiliary speed change mechanism 12 forward hydraulic clutch 13 reverse hydraulic clutch 14 forward hydraulic valve 15 reverse hydraulic valve 18 main speed change lever 19 auxiliary speed change lever 20 forward and backward switching Lever 28 Control device 29 Forward operation detection switch 30 Neutral operation detection switch 31 Reverse operation detection switch 35 Vehicle speed sensor

Claims (3)

A traveling aircraft,
A traveling speed change mechanism for stepwise changing the traveling power of the traveling machine body,
A forward hydraulic clutch and a reverse hydraulic clutch that switch between forward and backward travel of the traveling body,
A tractor comprising: a controller for increasing or decreasing the forward hydraulic clutch or the reverse hydraulic clutch according to the operation of the forward/reverse switching operation tool to advance or reverse the traveling machine body,
A forward/reverse operation detecting means for detecting an operation of the forward/reverse switching operation tool,
A vehicle speed detecting means for detecting a vehicle speed of the traveling machine body,
The control device is
Clutch connection control means for boosting control of the forward hydraulic clutch or the reverse hydraulic clutch in a predetermined boosting pattern regardless of the shift stage of the traveling speed change mechanism when the forward/reverse switching operation tool is operated forward or backward. When,
When the acceleration of the traveling machine body is determined based on the detected vehicle speed during the boost control and it is determined that the acceleration has changed in the increasing direction, the boost suppression that suppresses the boost of the forward hydraulic clutch or the reverse hydraulic clutch is suppressed. A tractor. When the control device determines that the vehicle speed of the traveling machine body has reached a target speed based on the detected vehicle speed during the boost control, boost control means for promoting boost of the forward hydraulic clutch or the reverse hydraulic clutch. The tractor according to claim 1, further comprising: The boosting means determines that the vehicle speed of the traveling vehicle body has reached a target speed when it is determined that the vehicle speed of the traveling vehicle body is stable based on the detected vehicle speed during the boosting control. The tractor described in 2.

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