JP2019062794A - Work vehicle - Google Patents

Abstract

To provide a work vehicle which enables providing a work vehicle capable of quickly coping even at an emergency in stationing work.SOLUTION: A work vehicle includes: a PTO shaft 3 for outputting the power of an engine 2 to the outside via a PTO clutch 3a controlled with a control device C; a PTO operation tool 3e for operating the PTO clutch 3a in a state of being seated on a driver seat 5; and a stationary PTO operation tool 3b for operating the PTO clutch 3a in a state of leaving from the driver seat 5. The control device C stops the drive of the PTO shaft 3 in the case of detecting the operation of the other operation tool when the PTO shaft 3 is driven by the stationary PTO operation tool 3b.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a work vehicle.

  In the work vehicle described in Patent Document 1, a seating sensor is provided in the driver's seat, and control for stopping the engine when the operator leaves the seat is ensured to ensure equipment operation by the operator's operation in the driver's seat. In the case of leaving the seat, it is possible to prevent the unmanned movement of the vehicle due to forgetting to turn off the engine or the like to ensure safety.

  Also, when operating a stationary work machine such as a water pump or a wood crusher by supplying power from the PTO shaft of the work vehicle, operating the stationary work switch provided in the vicinity of the PTO shaft cuts off the transmission system transmission. By sending a seating signal together with the operation of the PTO shaft under the condition that the parking brake is activated, engine operation can be performed while preventing unmanned movement of the vehicle under engine operation and ensuring safety even when the operator leaves the seat. Ground work including stationary operation of the PTO shaft is possible.

  The work vehicle described in Patent Document 2 includes a stationary PTO operating tool for operating the PTO clutch and a seating sensor for detecting the presence or absence of the driver's seat, and the control device is a seating sensor before the stationary PTO operating tool is operated. When the detection of leaving the seat by continues for a predetermined time, the engine is stopped, and when the detection of leaving by the seating sensor provided at the driver's seat continues for a predetermined time, the stationary PTO operation tool is operated Allowing safe work travel by a control system that operates on the premise of seating at the driver's seat by engaging the PTO clutch and operating the PTO shaft, and leaving the seat only with a simple operation It is possible to ensure the safety at the same time and the stable stationary operation of the PTO device.

Unexamined-Japanese-Patent No. 1-155037 JP, 2017-7377, A

  However, in the above-mentioned technology, a problem occurs during stationary operation and there is no effective method when it is desired to immediately stop driving the PTO. In addition, it is conceivable to provide a stop switch somewhere on the vehicle body, but in order to stop quickly in an emergency, conditions such as the operator correctly grasping the position of the switch were necessary.

  An object of the present invention is to provide a work vehicle capable of quickly dealing with an emergency in a stationary operation.

  The present invention has the following features in order to solve the above problems.

  The first feature is to drive the PTO shaft (3) for outputting the power of the engine (2) to the outside through the PTO clutch (3a) controlled by the control device (C), and the PTO clutch (3a) A PTO operating tool (3e) operated with the seat (5) seated, and a stationary PTO operating tool (3b) operated with the PTO clutch (3a) removed from the driver seat (5) The control device (C) stops the drive of the PTO shaft (3) when detecting the operation of another control device while the PTO shaft (3) is being driven by the stationary PTO operation tool (3b). It is characterized by

  As a result, since driving of the PTO can be stopped by operating the other operation tool during stationary work, it is possible to cope with urgent cases quickly.

  The second feature is that the work vehicle having the first feature is provided with a PTO revolution number sensor (24) for detecting the number of revolutions of the PTO, and the PTO control unit drives the PTO by a stationary PTO operation tool (3b) And a safety mode for stopping the PTO when the fluctuation of the rotational speed of the PTO exceeds a predetermined value.

  As a result, when the PTO rotational speed is monitored and the rotational speed fluctuates beyond the assumption due to an abnormal load, the drive of the PTO can be automatically stopped, so that it is possible to promptly cope with an emergency.

  A third feature is that, in the work vehicle having the second feature, a safety mode switch (S) for switching on and off of the safety mode is provided in the vicinity of the stationary PTO operation tool (3b).

  As a result, when performing work where load fluctuation is originally expected, the PTO drive is stopped one by one by operating the safety mode switch (S) when operating the stationary PTO operation tool (3b) and releasing the safety mode. Can be prevented.

  A fourth feature is that, in the work vehicle having the second or third feature, the PTO control unit causes the stationary PTO operation tool (3b) to start driving after a predetermined time has elapsed after the PTO starts driving. Automatically turn on.

  Thus, it is possible to prevent the safety mode from being left after the start of the stationary work.

  A fifth feature relates to the working vehicle having the first to fourth features, wherein the other operation tool is a forward / backward advancing lever (3d) for switching forward / backward of the working vehicle (1), and a main transmission portion (4e) The main shift lever (3g) that switches the shift of), the auxiliary shift lever (3h) that switches the shift of the auxiliary transmission unit (4g), and the seating sensor (5a) that detects the seating of the driver's seat (5) It features.

  As a result, the rotational drive of the PTO shaft 3 can be stopped by a lever or seating that is easy to operate, so that it is possible to quickly cope with an emergency.

  According to the work vehicle having the above features, in stationary work, it is possible to quickly cope with an emergency.

PTO control flowchart Transmission system development of the tractor Input / output block diagram of transmission control system Tractor side view PTO safety control flowchart

  An embodiment of a work vehicle of the present invention will be described based on the drawings.

  The power output mechanism PTO (Power Take Off) of the work vehicle 1 is a mechanism that outputs power from the PTO shaft 3 to move the connected work machine. The rotational drive force of the engine 2 is transmitted to the PTO transmission 3f via the PTO clutch 3a in the transmission case T, as shown in FIG. 2, according to the combination of the gears of the transmission 3f, as shown in FIG. The rotational driving force appropriately reduced is output from the PTO shaft 3 at the rear of the vehicle to the outside.

  The transmission case T is divided into a traveling system of traveling wheels 4 a and 4 b and a working system of the PTO axis 3 from an input shaft 2 a receiving engine power and transmitted. One traveling system is transmitted to the rear wheel differential 4h and the front wheel differential 4j through the main transmission 4e, the high / low switching 4f, and the auxiliary transmission 4g in addition to the forward / reverse switching 4c. Left and right brakes 4d, 4d are provided on the rear wheel differential portion 4h. The other working system transmits power from the PTO clutch 3 a to the PTO shaft 3.

  Forward / reverse switching unit 4c for adjusting transmission, main transmission unit 4e, elevation switching unit 4f, left and right brakes 4d and 4d for traveling wheel braking, and PTO clutch 3a are respectively a forward / reverse switching solenoid valve v1 and a main shift first solenoid The hydraulic pressure can be controlled by the control device C via the valve v2, the main transmission second solenoid valve v3, the high / low switching solenoid valve v4, the right brake solenoid valve v5, the left brake solenoid valve v5, and the PTO clutch solenoid valve v6.

  In the forward / reverse switching unit 4c, the forward / backward lever position sensor 21 connected to the control device C constituted by a microcomputer or the like detects the operation position of the forward / backward movement lever 3d, and according to the operation position By passing an electric current through the forward and reverse solenoid valve v1, the oil passage is switched and the forward and reverse clutch 11 is operated to switch between forward rotation and reverse rotation of the drive wheel.

  The main transmission lever position sensor 22 detects the operation position of the main transmission lever 3g, and the main transmission first solenoid valve v2 and the main transmission from the control device C according to the operation position The first main transmission cylinder 18 and the second main transmission cylinder 19 that operate the first main transmission clutch 12 and the second main transmission clutch 13 by supplying current to the second solenoid valve v3 and the high / low switching solenoid valve v4, respectively When the high-low switching clutch 14 is operated, the main transmission unit 4 e performs 4 speeds, and the high-low switching unit 4 f performs 2 × 4 = 8 = 8 speed change.

  When the auxiliary transmission lever 4h operates the auxiliary transmission lever 3h, the first auxiliary transmission clutch 15 and the second auxiliary transmission clutch 16 connected by the link mechanism are operated to perform four-speed shifting. Further, the operation position of the auxiliary transmission lever 3 h is detected by the auxiliary transmission lever position sensor 23 and is input to the control device C.

  The left and right brakes 17d are operated by the current flowing from the control device C to the left and right brake solenoid valves v5 and v5, in addition to the operation system for directly operating the brake pedal 3i to brake the rear wheel. It has an electric control system that is operated to brake the rear wheel.

  The PTO clutch 3a is a PTO shaft 3 as a current is supplied to the PTO clutch solenoid valve v6 from the control device C that recognizes the input of the PTO switch 3e described later or the stationary PTO switch 3b as an example of the stationary PTO operation tool. Transmission / shutoff of power to the vehicle is operated.

  As shown in the control block diagram of FIG. 3, the control device C is an on / off signal from the stationary PTO switch 3b for turning on / off the rotation of the PTO shaft 3 from the outside of the work vehicle 1, the driver's seat 5 (see FIG. 3). The driver sitting on the on / off signal from the PTO switch 3e which turns on / off the rotation of the PTO shaft 3, the operation position signal of the forward / reverse lever 3d from the forward / reverse lever operation position sensor 21, the main shift lever operation position sensor 21 Position signal of the main shift lever 3g from the control position signal of the sub shift lever 3h from the sub shift lever operation position sensor 21, seating presence / absence signal from the seat switch 5a for detecting seating of the driver, safety of stationary PTO work A safety mode on / off signal from the safety mode switch S that switches on / off the mode is input.

  Further, the control device C is a first main shift cylinder for shifting the current to the forward / reverse switching solenoid valve v1 electrically operating the forward / backward clutch 11 switching the forward / rearward movement of the work vehicle 1 and the traveling speed of the work vehicle 1 To the main shift second solenoid valve v3 electrically operating the second main shift cylinder shifting the traveling speed of the work vehicle 1 together with the current to the electrically operated main shift first solenoid valve v2 and the first main shift cylinder Current to the high / low switching solenoid valve v4 that electrically switches the high / low switching clutch 14 of the high / low switching unit 4f that shifts the rotational power shifted by the main transmission unit 4e into two stages in , 4d, the current to the left and right brake solenoid valves v5, v5 that electrically operate the left and right brake cylinders 17, 17 and the rotation of the PTO shaft 3 Electrically current to PTO clutch solenoid valve v6 operating is outputted controlled hydraulic PTO clutch 3a which Nyusetsu a.

  Further, the control device C transmits and receives signals to and from the engine control device 2c, and the engine control device 2c controls a fuel supply valve v7 to the engine 2.

  Regarding the operation of the PTO shaft 3, in addition to the PTO switch 3e for traveling and driving the coupled work machine, the stationary PTO switch 3b is separately provided as a stationary PTO operation tool for stationaryly driving the stationary work machine 40. The stationary PTO switch 3b is disposed in the vicinity of the PTO shaft 3 such as a rear wheel fender F as shown in FIG. In addition, if the rotational speed of the PTO shaft 3 is detected and monitored by the PTO rotational speed sensor 24 in the vicinity of the stationary PTO switch 3b and there is a fluctuation (for example, 10%) of the predetermined rotational speed, the PTO shaft 3 is driven. A safety mode switch S is provided to switch on and off the safety mode to be stopped.

  Further, the stationary work machine 40 is a wood crusher, a PTO input generator or a pump, etc., and it is connected to the work vehicle 1 without taking the work vehicle 1 to travel and only the driving force is taken out from the PTO shaft 3 , It is a working machine of the type that performs work. When working using such a working machine, the driver often gets off the working vehicle 1 and works.

  The other seat switch 5a is installed at the lower part of the driver's seat 5, the main shift lever 3g and the sub shift lever 3h are installed near the driver's seat 5, and the forward / backward lever 3d near the lower part of the steering wheel 6 ahead of the driver's seat 5, A PTO switch 3e is provided to drive the PTO shaft 3 when traveling.

  The operation control of the PTO shaft 3 will be described with reference to the processing in the control device C. As shown in the flowchart of FIG. 1, a first control processing step (hereinafter referred to as "S1") for determining the operation of the stationary PTO switch 3b. If the fixed PTO switch 3b is on, both the left and right brakes 4d are operated (S2), and at the same time the PTO clutch 3a is connected (S3) to drive the PTO shaft 3.

  If the stationary PTO switch 3b is not on, the operation of both the left and right brakes 4d is released (S4), and the operation of the PTO switch 3e is determined (S5). If the PTO switch 3e is on, the PTO shaft 3 is driven by connecting only the PTO clutch 3a without operating the both brakes 4d (S6). If the PTO switch 3e is off, a signal to shut off the PTO clutch 3a is transmitted, and the process is ended (S7).

  In addition, in the control system that enables stationary PTO operation on condition that the parking brake is operated at the time of stationary PTO operation, control processing of attachment of lever position sensor of parking brake and lever position determination is required. By securing the vehicle body by the operation, the control configuration can be simplified, and furthermore, a reliable braking action can be obtained from a parking brake whose braking force varies depending on the degree of operation.

  FIG. 5 is a PTO safety control flowchart as an example of the embodiment of the work vehicle 1. When the control device C detects the absence state from the seat switch 5a provided at the lower part of the driver's seat 5, the timer in the control device C starts measurement of the absence state continuation time. It is determined whether the absence state continues for a predetermined time (for example, 10 seconds) (S8). When the absence state continues for a predetermined time, the engine 2 is stopped (S9) to prevent the engine 2 from being turned off and the work vehicle 1 from traveling with the driver absent.

  It is determined whether the stationary PTO switch 3b is turned on until the absence state continues for a predetermined time (S10). When the stationary PTO switch 3b is not turned on, the determination is repeated until the on operation is performed or the absence state continues for a predetermined time.

  If the stationary PTO switch 3b is turned on before the absence state continues for a predetermined time, the PTO clutch 3a is connected, and the drive of the PTO shaft 3 is started (S11). At this time, the control device C starts measuring the time from the start of driving of the PTO shaft 3 using an internal timer.

  When the PTO shaft 3 is driven by the stationary PTO switch 3b, it is determined whether the operation of any other operation tool other than the stationary PTO switch 3b has been detected (S5). When the operation of another operating tool is detected, the PTO clutch 3a is immediately shut off to stop the drive of the PTO shaft 3 (S6). The other operating tool mentioned here may be anything that can electrically detect that the control device C has operated. For example, the operation of the forward / reverse lever 3d detected by the change of the input value of the forward / reverse lever position sensor 21, the operation of the main shift lever 3g detected by the change of the input value of the main shift lever position sensor 22, an auxiliary shift lever position sensor The operation of the auxiliary shift lever 3h detected by the change of the input value of 23 corresponds to the above.

  In addition, the drive of the PTO shaft 3 may be stopped by detecting the operation of the operation device or horn of the lighting device (not shown) or the operation of the steering wheel 6, or even if the drive of the PTO shaft 3 is stopped when the seat switch 5a changes. good. As described above, by stopping the drive of the PTO shaft 3 during stationary work by operating any operation tool, the operator can use the stop switch when an emergency requiring situation such as abnormal vibration or malfunction of the stationary work machine 40 occurs. Even if you do not know the location and stop operation method of, it is possible to cope quickly by moving any of the operation tools nearby.

  When the PTO shaft 3 is driven by the stationary PTO switch 3b, the other operating devices have a role as an emergency PTO stop operating device, so it is better not to operate the normal function when operating under this condition. For example, even if the forward / reverse lever 3d is operated in the forward direction during the stationary operation, it is preferable for safety to keep the neutral state without the forward / backward clutch 11 being connected.

  When the operation of the other operation tool is not particularly detected, the control device C determines whether the safety mode switch S has been turned OFF after the start of driving of the PTO shaft 3. When the OFF operation is performed, the drive of the PTO shaft 3 is continued as it is, and the monitoring (S5) whether or not there is an operation of another operation tool is continued.

  If the safety mode switch S is not turned OFF, it is determined whether a predetermined time (for example, 10 seconds) has elapsed since the start of driving the PTO shaft 3 (S8). When the predetermined time has elapsed, the safety mode is automatically turned on (S9) to prevent the safety mode from being forgotten. In addition, it is determined whether or not the safety mode switch S10 is turned on even before the predetermined time has passed (S10), and when it is turned on, the safety mode is immediately turned on (S9).

  Until the predetermined time has elapsed from the start of driving the PTO shaft 3 or until the safety mode switch S is turned on, the driving of the PTO shaft 3 is continued and monitoring of whether or not there is an operation of another operating tool Continue (S5).

  When the safety mode is turned on (S9), the controller C monitors the amount of change of the rotational speed of the PTO shaft 3 from the detection value of the PTO rotation sensor 24 (S11), and the change amount is a predetermined value (for example, rated rotational speed) When the PTO clutch 3a is shut off immediately, the drive of the PTO shaft 3 is stopped (S6). If the amount of change does not exceed the predetermined value, the drive of the PTO shaft 3 is continued as it is, and the monitoring (S5) whether or not there is an operation of another operating tool is continued.

  When the safety mode is turned on, the driving of the PTO shaft 3 is automatically stopped when an abnormal load is applied to the stationary work machine 40, etc., so that the stationary work can be performed safely. Specifically, it is possible to quickly cope with a case where metal or the like is mixed in the input to the stationary work machine 40 such as a wood crusher or a case where the stationary work machine 40 is broken.

  If a post-load operation is assumed from the beginning, the safety mode switch S should be turned off beforehand (S7), and the operation will stop one by one due to the fluctuation of the PTO shaft 3 speed. It can prevent the occurrence.

  Moreover, although the example which performs monitoring of the load in stationary PTO operation | work by the rotation speed detection of PTO axis | shaft 3 was shown in the present Example, you may monitor engine rotation speed. Besides, abnormal vibration may be detected by a tilt sensor or the like to control the drive of the PTO shaft 3.

C Control device S Safety mode switch 1 Work vehicle 2 Engine 3 PTO shaft 3a PTO clutch 3b Stationary PTO switch (stationary PTO operation tool)
3d back and forth lever (other operation tool)
3g Main shift lever (other operation tool)
3h Secondary shift lever (other operation tool)
5 driver's seat 5a seating sensor 24 PTO speed sensor

Claims (5)

A PTO shaft (3) for outputting the power of the engine (2) to the outside through a PTO clutch (3a) controlled by the control device (C);
A PTO operation tool (3e) for operating the PTO clutch (3a) in a state of being seated on a driver's seat (5);
A stationary PTO operation tool (3b) for operating the PTO clutch (3a) in a state of leaving the driver's seat (5);
The control device (C) stops the driving of the PTO shaft (3) when detecting the operation of another operating tool while the PTO shaft (3) is being driven by the stationary PTO operation tool (3b).
Work vehicle. It has a PTO speed sensor (24) that detects the speed of the PTO,
The PTO control unit has a safety mode for stopping the PTO when the fluctuation of the rotational speed of the PTO shaft (3) exceeds a predetermined value when the PTO is driven by the stationary PTO operation tool (3b).
The work vehicle according to claim 1. A safety mode switch (S) for switching the safety mode on and off is provided in the vicinity of the stationary PTO operation tool (3b),
The work vehicle according to claim 2. The PTO control unit automatically turns on the safety mode when a predetermined time has elapsed after the PTO starts to be driven by the stationary PTO operation tool (3b).
A work vehicle according to claim 2 or 3. The other operation tools include a forward / reverse lever (3d) that switches forward and backward movement of the work vehicle (1), a main transmission lever (3g) that switches the shift of the main transmission unit (4e), and an auxiliary transmission unit (4g) And a seating sensor (5a) for detecting the seating of the driver's seat (5).
The work vehicle according to any one of claims 1 to 4.

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