JP5899909B2 - PTO control device for work vehicle - Google Patents

Description

  The present invention relates to a PTO control device for a work vehicle in which driving of a PTO output shaft can be controlled by an internal switch provided near a cockpit and an external switch provided outside a fuselage.

  In a work vehicle such as a tractor, a PTO control device for a work vehicle is known that includes an internal switch 0 that is operated at a cockpit and an external switch that is operated outside the aircraft, and performs drive control of the PTO device. The internal switch is for turning on / off the PTO device at the cockpit, and the external switch is used to stop the PTO output shaft being driven from the outside.

  This two-system PTO control device uses the external switch to stop the PTO output shaft and work around the work machine, so that another operator accidentally operates the internal switch to drive the PTO output shaft. If this happens, an operator working near the work machine will be in a dangerous state. To prevent this, Japanese Patent Application Laid-Open No. 2008-94245 discloses a stop state after the PTO output shaft is stopped by an external switch. Thus, it is considered that the PTO output shaft cannot be driven even if the internal switch is operated so as to make the operator safe.

JP 2008-94245 A

  In the PTO control device for a work vehicle provided with the internal switch and the external switch in the above-described prior art, when the engine is stopped and the supply of current is stopped, the forced stop state of the PTO output shaft at the external switch is released. When the engine is restarted after the engine is stopped, the PTO device can be driven with an internal switch, and the PTO output shaft may be driven by turning on the internal switch without paying attention to an outside operator. The worker near the work machine may be in a dangerous state.

  Therefore, according to the present invention, when the engine is stopped and restarted to perform work or inspection, the PTO output shaft is driven by an erroneous operation of the internal switch so that a person near the work machine is not put in a dangerous state. An object is to provide a PTO control device for a vehicle.

The problems of the present invention are solved by the following technical means.
The invention according to claim 1 is an external switch for detecting ON / OFF of the external switch 56 in the PTO control device of the work vehicle provided with the internal switch 20 for turning ON / OFF the drive of the PTO output shaft 19 and the external switch 56. the detecting means 56a is provided, by detecting the external switch detecting unit 56a is oN when starting the engine 4, controlled not perform the driving of the PTO output shaft 19, ignoring the oN operation by the internal switch 20, an external The ON operation of the external switch 56 after detecting the OFF state of the switch 56 for a predetermined time by the external switch detecting means 56a is determined as a normal ON operation, and the PTO output shaft 19 is driven. The PTO control device for a work vehicle starts counting at the start .

  With this configuration, even when the engine 4 is restarted after being stopped, if the external switch detecting means 56a detects the ON state of the external switch 56 by the ON operation before the restart or the ON state due to a failure, the internal switch 20 is turned ON. Even if the operation is performed, unless the external switch 56 is turned off, the PTO output shaft 19 is not driven, so that the worker around the work implement is safe.

Also, since the PTO output shaft 19 is not driven by an instantaneous ON / OFF signal caused by an operator touching the external switch 56 unexpectedly or the vehicle body vibrating, it is safe.

In addition, by ignoring the OFF time before driving the engine and counting the OFF time from the start of the engine, the ON signal due to a large vibration at the start is ignored and the PTO device is not driven, which is safe.

The invention according to claim 2 is an external switch for detecting ON / OFF of the external switch 56 in the PTO control device of the work vehicle provided with the internal switch 20 for turning ON / OFF the drive of the PTO output shaft 19 and the external switch 56. If detecting means 56a is provided and the external switch detecting means 56a detects the ON state when the engine 4 is started, the PTO output shaft 19 is controlled so as not to be driven by ignoring the ON operation by the internal switch 20. A monitor 50 is provided in the vicinity of the switch 56, and the reason why the PTO output shaft 19 cannot be turned ON / OFF by the external switch 56 is displayed on the monitor 50.

With this configuration, the operator can quickly know on the monitor 50 whether or not the reason why the external switch 56 does not work is due to the OFF state of the internal switch 20 or a failure.

  In the invention according to claim 1, even when the engine 4 is restarted after being stopped, when the external switch detecting unit 56a detects the ON state of the external switch 56 by the ON operation before restart or the ON state due to failure, Even if the internal switch 20 is turned on, the PTO output shaft 19 is not driven unless the external switch 56 is turned off, so that the workers around the work machine are safe.

Also, since the PTO output shaft 19 is not driven by an instantaneous ON / OFF signal caused by an operator touching the external switch 56 unexpectedly or the vehicle body vibrating, it is safe.

Also, by measuring the OFF time from the start of the engine while ignoring the OFF time before driving the engine, the PTO device is not driven by ignoring the ON signal due to large vibrations at the start, so that it is safe.

According to the second aspect of the present invention, the operator can quickly know on the monitor 50 whether or not the reason why the external switch 56 does not work is due to the OFF state of the internal switch 20 or a failure.

1 is an overall side view of an agricultural tractor. It is a principal part perspective view of a cockpit. It is a sketch of a switch box. It is a sketch of a meter panel. It is a principal part perspective view of a fender. It is a control block diagram of automatic control.

Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.
An agricultural tractor as an example of a work vehicle to which the present invention is applied will be described.
As shown in FIG. 1, the agricultural tractor 1 is a hood that includes a front cabin 2, 2, rear wheels 3, and 3, and includes a steering cabin 7 that covers the front of the aircraft. 10, the engine 4 is mounted, the rotational power of the engine 4 is transmitted to the transmission gear 5 a in the transmission case 5, and the power appropriately decelerated by the transmission gear 5 a is transmitted to the front wheels 2, 2 and the rear wheels 3, 3, and a driving force is output via a PTO output shaft 19 to a working machine (not shown) connected to a 3P link that can be raised and lowered at the rear of the machine body.
(cabin)
In the cabin 7, as shown in the perspective view of FIG. 2, a pilot seat 7s is disposed at an upper position of the mission case 5, and an armrest 21 on one side of the pilot seat 7s and an operation panel device 22 described later on the outer side thereof. In addition, a parking brake 7b, PTO change levers 7c, 7d, etc. are arranged on the other side of the cockpit 7s to constitute an operation unit, and a forward / reverse switching lever 11a is provided in the vicinity of the steering handle 11, and a base part is provided. Traveling operation tools such as a clutch pedal 11b, left and right brake pedals 11c and 11d, and an accelerator pedal 11e are arranged. The steering post is provided with a meter panel M (described later) for displaying device information including a speedometer, and the armrest 21 is provided with a work implement lift lever 21a, a work implement lift switch 21b, and travel shift switches 21c, 21d. An operation tool for work traveling such as is arranged.
(Operation panel device)
The operation panel device 22 is a device in which operating means such as a work machine, a traveling system, and an engine speed are concentrated on one side of the cockpit 7s (right side in the example) in order to improve operability. An operating tool for controlling and operating the traveling system and working system equipment to be configured, and an operating console that supports these operating tools and is concentrated on one side of the cockpit 7s, and further includes a switch box 26a described later. Prepare.

  The console is composed of a flat base stage operating section 23 adjacent to the cockpit 7s, a middle stage operating section 24 standing up at a steep slope from the back side, and an upper stage operating section 25 tilting gently from the upper end to the back height. The operation tool is arranged in each. That is, it is configured to cover the upper surface with an integral lever guide, and a flat base stage operation unit 23 is formed near the cockpit 7s, and far from the seat on the back side from the base stage operation unit 23, An upper stage operation unit 25 is provided with an inclined surface that is slightly inclined and is higher than the base stage operation unit 23, and the upper stage operation unit 25 and the base stage operation unit 23 are arranged at a middle stage operation unit with an inclined surface that is tighter than the tilt. The arrangement surface is configured so as to be connected at 24, and operation tools such as operation switches and levers are arranged on all the surfaces.

In particular, the base stage operation unit 23 and the middle stage operation unit 24 that are close to the cockpit 7s are provided with electrical operation tools such as switches, and the upper operation unit 25 that is relatively far away is provided with an operation tool using levers that perform a stroke operation. By arranging, operability according to the operation tool can be secured.
(Base section)
The specific description of each operation tool of the operation panel device 22 is as follows.

In the base stage operation unit 23, operation switches for directly performing transmission and interruption of transmission power such as an internal switch 20 for turning on / off the drive of the PTO output shaft 19, a PTO manual automatic changeover switch, and a differential lock switch are arranged. Since these switches are simple on / off operations, the switches can be easily operated even in a relatively cramped posture with the arm bent.
(Middle section)
The middle stage operation unit 24 is provided with two engine speed storage switches, a draft ratio adjustment dial, a raising adjustment dial, a tilt adjustment dial, a 4WD changeover switch, a horizontal cylinder manual raising / lowering switch, and the like.
(Upper part)
A throttle lever 25a, sub-transmission lever 25b, sub-con levers 25c and 25d, an optional sub-con lever 25e, and a switch box 26a are arranged at the rear of the console.
(Switch box)
As shown in FIG. 3, the switch box 26a is configured such that a cover can be opened and closed on a switch panel 31 containing a plurality of switches. This is arranged to be inclined toward the operator of the cockpit 7s at the rear position of the console. The switch box 26a is configured to be compact with a small operation unit for functions that are used infrequently. The switch box 26a is located outside the operator's field of view when not used, and is disposed at a close position that can be operated from the cockpit 7s when used. By doing so, all functions can be operated from the cockpit seat 7s as needed by the user or by the work without hindering the normal work.

  The switch panel 31 has a comparatively large adjustment operation portion including two monitor lamps L and L, an AT shift work sensitivity dial 32b, a lowering speed dial 32c, and a brake adjustment dial 32d as work implement up / down display portions 32a. In addition, the return type switch buttons by the momentary switches 33a to 33e and 34a to 34e of the control setting including the electrohydraulic control are arranged relatively closely together with the monitor lamp L.

  The work implement ascending / descending monitor lamp 32a is displayed as a monitor in conjunction with the work implement raising / lowering output by lamps L, L such as two LEDs arranged vertically. A cover is formed of translucent resin, and the cover can be displayed as a monitor with the cover closed. This monitor display is convenient for seeing the effect during drafting and the like, and can be constructed at low cost by putting the LED on the substrate.

  The AT shift work sensitivity dial 32b is a dial that automatically changes the sensitivity to increase or decrease the vehicle speed. When the AT shift work switch 33b disposed below is set to “ON”, automatic shift (ored drive) control is applied with the set sensitivity.

  The lowering speed dial 32c adjusts the work implement lowering speed. Applicable when operating on the “fast” side (clockwise), the work equipment descends faster and the work equipment weight is light. Applicable when the work implement descends slowly when operated to the “slow” side (counterclockwise) and the work implement weight is heavy. The brake adjustment dial 32d adjusts the braking force that is applied when the auto brake switch 33e is “ON” (the left is weak and the right is strong).

In addition, for each of the control setting switches 33a to 33e, 34a to 34e such as electrohydraulic control, the switch button B and the monitor lamp L thereof are arranged correspondingly.
When the AT shift road switch 33a is set to “ON”, it automatically shifts (auto-drives) when traveling on the road.

When the AT shift work switch 33b is set to “ON”, it automatically shifts (auto-drives) during work travel.
When the backup on / off switch 33c is set to “ON”, the work implement rises in conjunction with the reverse operation.

When the auto-lift on / off switch 33d is set to “ON”, the work implement is raised in conjunction with the steering wheel operation when the machine is turning.
When the auto brake on / off switch 33e is set to “ON”, only the rear wheel on the inside of the turn is braked in conjunction with the operation of the steering wheel during turning.

  The connection sensitivity shift switch 34a changes connection feeling when the main shift is shifted by turning on and off. “On” (monitor lit) makes a gentle shift, and “Off” (monitor off) makes a quick connection. When used in a traction system such as a plow, the connection time during the main speed change operation is shortened.

  The connection sensitivity PTO switch 34b switches how PTOs are connected. “Rotary” speeds up PTO connections. When the PTO begins to rotate, it immediately turns with a rotational force that does not lose the resistance of the soil, so it is mainly used with tillage machines such as rotary. “Grass 1” and “Grass 2” have a slow PTO connection (two shifts). Mainly used for work machines that slowly connect PTO, such as pasture work machines and snow blowers.

The horizontal sensitivity switch 34c switches the operation sensitivity of the automatic horizontal control device. Pressing the switch slows down the automatic horizontal control, and pressing it again restores it.
The horizontal changeover switch 34d performs horizontal control of the work machine. “Auto level” automatically maintains level by a level sensor. “Manual” is for manual adjustment by the tilt adjustment dial 24e. “Parallel” always makes the 3P link parallel to this machine. “Slope” gives a certain angle to the ground.

  The 3P changeover switch 34e selects 3P changeover of the electrohydraulic operation box by selecting a lift cylinder mounting hole. “1” is selected for category 1 work machines (when attached to the front hole of the lower link), and “2” is selected for category 2 work machines (when attached to the rear hole of the lower link).

  Each of the above control setting switches 33a to 33e and 34a to 34e can easily grasp the failure (short circuit) of the switch by controlling the lighting of the monitor only when the switch is on during the check mode state in the equipment operation maintenance. can do.

  For example, during normal control, the monitor is turned on and off in response to the switch operation. If the monitor does not turn on even when the switch is pressed, it cannot be determined whether the switch or the monitor is faulty. By making the light-up only when is on, it is easy to determine the site of failure (switch, monitor). Further, only the change of the switch can be confirmed on the meter panel M.

  Also, the transition to the check mode is made on condition that the predetermined fuse is removed.In this machine, the control is performed by the setting of the operation panel before the transition to the check mode. By adopting a control configuration that does not switch the traveling system, it is possible to prevent unexpected movement of the device.

In this case, if the setting state is stored in the non-volatile memory of the control system controller, that value is used. If the setting state is stored in the non-volatile memory of the operation panel itself, that value is used. By doing so, it is possible to prevent unexpected movement of the device.
(Meter panel)
As shown in the sketch diagram of FIG. 4, the meter panel M displays the operation status of various devices in addition to the engine tachometer 41 at the center position.

Specifically, left and right blinker lamps 42a and 42b at the upper edge, warning lights 42c and diff lock indicator lights 42d following the right side thereof, AT shift work indicator lamps 43a and road indicator lamps 43b as left-side work machine indicators, Auto lift indicator light 44a, auto brake indicator light 44b, backup indicator light 44c, PTO indicator light 44d, lift lamp 44e, auto accelerator indicator light 44f, accelerator memory work A indicator light 44g, work B indicator light 44h, right side As the main shift position, vehicle speed, fuel and water temperature display by the composite display liquid crystal display 45, and the travel system display below the main shift position, the 2WD lamp 46a, the 4WD lamp 46b, the sudden turn indicator lamp 46c, the parking brake indicator lamp 46d, the brake pedal An unconnected warning light 46e and the like are arranged.
(Fender)
Next, the fender outside the fuselage will be described.

  As shown in FIG. 5, the left and right fenders 51 are curved so as to cover the upper part of the rear wheel, as shown in FIG. 5. In addition to a composite taillight 53 including a brake light, direction indicator light, etc., a monitor 50 indicating the driving state of the PTO output shaft 19, and a reflector 54, an external switch 56 for stopping the PTO and a switch for adjusting the vehicle height are arranged. The external operation unit 55 is provided. The external switch 56 for stopping the PTO of the external operation unit 55 turns on / off the driving of the PTO output shaft 19 together with the internal switch 20 for turning on / off the PTO.

Although the left fender is shown in the embodiment, a similar switch may be provided for the right fender.
(PTO controller)
As shown in the control block diagram of FIG. 6, the PTO control device includes an internal switch sensor 20 a and a fender 51 of the internal switch 20 arranged in the base operation unit 23 of the operation panel device 22 on the input side of the control unit 61. The external switch sensor 56a of the external switch 56 for stopping the PTO and the PTO rotation sensor 57 are connected to the PTO solenoid 62 for transmission control of the PTO device, the monitor display meter panel M and the fender 51 on the output side. A monitor 50 to be provided is connected.

Control related to driving of the PTO output shaft 19 in the control unit 61 is performed as follows.
ON / OFF of the external switch 56 is detected by the external switch sensor 56a and input to the control unit 61. If the external switch 56 is in the ON state when the engine 4 is started, the ON operation by the internal switch 20 is ignored and the PTO output shaft It controls so that drive of 19 cannot be performed. If the external switch 56 is in an OFF state when the engine 4 is started, the OFF time is measured, and the PTO output shaft 19 is not driven even if the external switch 56 is turned on unless a predetermined time has elapsed. .

  The external switch detection means referred to in the present invention is the external switch sensor 56a, but it may be a non-volatile storage circuit that stores the ON state immediately before the engine 4 is stopped. In this case, the control unit Even if the power supply 61 is turned off, the PTO output shaft 19 can be controlled as described above.

  Further, the external switch detection unit 56a determines that the ON operation of the external switch 56 after detecting the OFF state of the external switch 56 for a predetermined time is a normal ON operation, and controls the PTO output shaft 19 to be driven, Even if the external switch 56 is turned on due to vibration of the airframe, the PTO output shaft 19 is not driven by a malfunction.

  In addition, when the PTO output shaft 19 is driven by the ON operation of the internal switch 20, if the external switch 56 is turned OFF for a predetermined time, the PTO output shaft 19 is controlled to stop driving, so that work outside the machine is performed. When the person feels danger, the drive of the work machine can be stopped.

  Also, a monitor 50 is provided in the vicinity of the external switch 56, and the monitor 50 displays whether the reason why the PTO output shaft 19 cannot be turned ON / OFF by the external switch 56 is due to a failure or whether the OFF time is too short.

  Even if the external switch 56 is turned on while the internal switch 20 is turned off, the ON operation of the external switch 56 is ignored and the stopped state of the PTO output shaft 19 is maintained.

Even if the internal switch 20 is OFF, the PTO output shaft 19 may not be driven by the external switch 56 unless the parking brake is operated.
In addition, while the stop by the external switch 56 is continued, a display different from that during PTO rotation is displayed on a display such as a monitor or a liquid crystal display that displays the rotation state of the PTO, for example, a blinking monitor lamp, a liquid crystal display, etc. By displaying a message such as “Needs engine stop operation”, it is possible to easily recognize that the PTO output shaft 19 cannot be rotated as it is.

Next, an automatic management system for hydraulic equipment such as a hydraulic clutch that operates in the mission case 5 will be described.
First, as the operating state of the hydraulic device, the ultimate pressure of each device at a predetermined oil temperature is measured and stored every predetermined recording time. This allows us to know that the ultimate pressure has dropped and the crisis has deteriorated, so that repairs and replacements can be made at the appropriate time. The ultimate pressure of each device does not activate a crisis when the recording time comes, but the ultimate pressure of each device is recorded during work use, and the record closest to the predetermined recording time is left as data. Also, the recorded data is cleared when it is delivered to the user, and the user's usage record is left.

  If the ultimate pressure fluctuates even if it is within the normal range or is gradually decreasing, the oil temperature, the total use time, the number of operations, etc. are displayed on the meter panel M as an abnormal state, Notify the administrator using a communication device. This abnormality history (abnormality code, occurrence time, abnormality duration, etc.) and maintenance history are recorded so that they can be confirmed later. Also, the adjustment values (factory connection pressure, piston stroke to clutch meet, etc.) at the time of factory shipment and maintenance are recorded.

With a fully automatic tractor using the GPS function, a sudden turning operation by one brake is made possible by confirming that the aircraft is in a predetermined field.
In addition, it is convenient for the cabin tractor to provide an atmospheric pressure sensor on the fuselage to predict sudden changes in weather due to fluctuations in atmospheric pressure and to light the warning light to notify the operator. At that time, the sensitivity of the atmospheric pressure sensor can be changed with an adjustment dial or the like provided near the cockpit 7s.

4 Engine 19 PTO output shaft 20 Internal switch 50 Monitor 56 External switch 56a External switch detection means

Claims (2)

External switch detection for detecting ON / OFF of the external switch (56) in the PTO control device of the work vehicle provided with the internal switch (20) and the external switch (56) for turning ON / OFF the drive of the PTO output shaft (19) If a means (56a) is provided and the external switch detection means (56a) detects the ON state when the engine (4) is started, the ON operation by the internal switch (20) is ignored and the PTO output shaft (19) is driven. The external switch (56) is determined to be a normal ON operation after the external switch detection means (56a) detects the OFF state of the external switch (56) for a predetermined time by the external switch detection means (56a). driven shaft (19), PTO control of the work vehicle OFF time measuring external switch (56), characterized in that starts counting when the engine is started Location. External switch detection for detecting ON / OFF of the external switch (56) in the PTO control device of the work vehicle provided with the internal switch (20) and the external switch (56) for turning ON / OFF the drive of the PTO output shaft (19) If a means (56a) is provided and the external switch detection means (56a) detects the ON state when the engine (4) is started, the ON operation by the internal switch (20) is ignored and the PTO output shaft (19) is driven. The monitor (50) is provided near the external switch (56), and the reason why the PTO output shaft (19) cannot be turned ON / OFF by the external switch (56) is displayed on this monitor (50). PTO control system of work vehicle shall be the feature to be.

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