JP3616540B2 - Management work vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a management work vehicle for raising and managing turf in golf courses, parks, etc., and more particularly to a management work vehicle that is hydraulically driven and capable of switching safely and easily between high-speed movement during movement and low-speed movement during work. is there.
[0002]
[Prior art]
This type of conventional management work vehicle is designed to work at a speed of about 6 to 7 Km / h during work such as lawn mowing, and to move at a speed of about 15 Km / h during moving forward. For this purpose, at least a high-speed and low-speed switching was necessary.
[0003]
[Problems to be solved by the invention]
However, since the conventional management work vehicle can always change the speed, there is a risk that the speed is suddenly reduced if the speed is changed from high speed to low speed during traveling. On the other hand, if it is possible to switch the speed only when the management work vehicle is stopped for safety reasons, there is a problem in work efficiency because it must be stopped once.
[0004]
The present invention has been made to solve the problems of the prior art, and its object is to provide a management work vehicle that can be easily switched to a desired speed while ensuring safety and work efficiency. is there.
[0005]
[Means for Solving the Problems]
That is, the present invention is a management vehicle including a traveling carriage having traveling wheels, an engine mounted on the traveling carriage, a hydraulic pump driven by the engine, and a hydraulic motor that drives the traveling wheels, The hydraulic motor is a hydraulic motor that can be switched to at least two large and small capacities, and the switching is a management work vehicle that can be switched when the speed of the management work vehicle becomes lower than the slow speed.
[0006]
The management work vehicle according to the present invention is configured so that the capacity of the hydraulic motor that drives the traveling wheel can be switched when the management work vehicle becomes lower than the slow speed, so that the safety and work efficiency can be easily reduced. A traveling state at a desired speed can always be ensured.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be specifically described below with reference to the drawings, but the present invention is not limited thereto.
[0008]
FIG. 1 is a hydraulic circuit diagram of a management work vehicle according to the present invention, FIGS. 2 and 3 are electrical circuit diagrams, and FIG. 4 is a cross-sectional view of an essential part showing an example of a speed sensing unit.
In FIG. 1, reference numeral 1 denotes an engine which is mounted on a traveling carriage (not shown) such as a lawn mower, a sweeper, or a herbicide sprayer. Reference numeral 2 denotes a hydraulic variable pump, which is driven by the engine 1 and increases the flow rate of oil when the swash plate 3 tilts. Reference numeral 4 denotes a hydraulic motor that rotates traveling wheels (drive wheels) 21 of the traveling carriage. The hydraulic pump 2 and the two hydraulic motors 4 are connected in parallel to form a closed circuit. S. T. T. et al. It is a circuit. That is, when the swash plate 3 tilts, the oil flow rate increases, and the hydraulic motor 4 is driven to travel forward. On the other hand, when the swash plate 3 tilts in the reverse direction, the hydraulic motor 4 reverses and moves backward. It has become. The hydraulic motor 4 is a two-speed motor whose capacity is switched between two levels depending on the pilot pressure. For example, a two-speed motor disclosed in Japanese Patent Laid-Open Nos. 59-138780 and 63-205402 is adopted. Can do. A charge pump 5 replenishes the amount of oil leaked in the closed circuit. 6 is a relief valve which controls the pressure in the closed circuit. 7 is an electromagnetic valve that supplies or blocks the charge pressure from the charge pump 5 to the pilot port for high-speed / low-speed switching of the hydraulic motor 4.
[0009]
In FIG. 2, reference numeral 8 denotes a power generator that performs rotational power generation in conjunction with the rotation of the drive wheel 21 of the traveling carriage. As the number of rotations increases, the amount of power generation increases. Reference numeral 9 denotes a comparator (voltage comparator) that detects the voltage from the power generator 8 and is displayed on the speedometer 22 according to the amount of power generated. The comparator 9 is configured to output an output signal when the voltage is below a certain voltage. 10 is an A contact relay, 11 is a changeover switch for the two-speed motor 4, 12 is a self-holding relay, and when the changeover switch 11 is switched to the high speed a side, the coil 13 is excited and the main contact 15 is turned on (energization) On the contrary, when the changeover switch 11 is set to the low speed b side, the coil 14 is excited and the main contact 15 is turned off (cut off), and the state can be maintained. Reference numeral 16 denotes a solenoid of the solenoid valve 7, which supplies the charge pressure of the charge pump 5 to the hydraulic motor 4 when energized, and shuts off the current when the energization is stopped.
[0010]
FIG. 3 shows another electric circuit diagram of the management work vehicle according to the present invention. Reference numeral 19 denotes a pulse meter which detects the rotation of the driving wheel 21 of the traveling carriage and generates a pulse. Reference numeral 20 denotes an FV converter which can convert a pulse generated by the pulse meter 19 into a voltage, and this FV converter 20 is connected to the comparator 9. As shown in the speed sensing section of FIG. 4, the pulse meter 19 detects the magnet 24 attached to the wheel 23 by a proximity sensor 25 and calculates the number of pulses.
[0011]
Next, the actual operation of the management work vehicle of the present invention will be described.
When the engine 1 is driven to rotate the hydraulic pump 2 and the swash plate 3 is tilted, the oil from the hydraulic pump 2 is supplied to the hydraulic motor 4, and the driving wheels 21 connected by the rotation of the hydraulic motor 4. Rotates and the carriage moves forward. The larger the tilt angle of the swash plate 3, the higher the flow rate and the higher the speed. At this time, when the solenoid 16 of the solenoid valve 7 is not energized, the charge pressure from the charge pump 5 is not supplied to the pilot port for high-speed / low-speed switching of the hydraulic motor 4, so the hydraulic motor 4 becomes a large capacity motor, It becomes a motor with low rotation and high torque. On the contrary, when the solenoid 16 of the solenoid valve 7 is energized and excited, the hydraulic motor 4 becomes a small capacity motor, and becomes a motor with high rotation and low torque. When switching the capacity of the hydraulic motor 4, when the speed of the traveling carriage becomes lower than the traveling speed (6 Km / h or less, preferably 4 Km / h or less, more preferably 3 Km / h or less), the driving wheel is linked. Then, the comparator 9 detects that the power generation amount of the generator 8 for rotating power generation has decreased and the voltage has decreased, an output signal is output, the coil 10a of the relay 10 is excited, and the contact 10b of the relay 10 is energized. Next, when the changeover switch 11 is turned to the low speed b side, the coil 14 is excited and the main contact 15 is cut off, the solenoid 16 is not excited and the hydraulic motor becomes a large capacity motor. At this time, the energization of the main circuit 18 is held as it is by the self-holding relay 12. The changeover switch 11 is not changed unless the speed of the traveling carriage is lower than the slow speed.
[0012]
【The invention's effect】
According to the present invention, the speed changeover switch is activated when the traveling carriage becomes lower than the slow speed, so that the speed is erroneously switched to a low speed during a high speed movement, and a sudden speed change is not caused. There is no need to switch speeds. Therefore, it is possible to easily switch to a desired speed while ensuring safety and work efficiency.
[Brief description of the drawings]
FIG. 1 shows an example of a hydraulic circuit diagram of a management work vehicle according to the present invention.
FIG. 2 shows an example of an electric circuit diagram of a management work vehicle according to the present invention.
FIG. 3 shows an example of an electric circuit diagram of a management work vehicle according to the present invention.
FIG. 4 shows an example of a speed sensing unit used in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 Hydraulic pump 3 Swash plate 4 Hydraulic motor 5 Charge pump 6 Relief valve 7 Electromagnetic valve 8 Generator 9 Comparator 10 A contact relay 11 Changeover switch 12 Self-holding relay 13 Coil 14 Coil 15 Main contact 16 Solenoid 18 Main circuit 19 Pulse meter 20 FV converter 21 Drive wheel 22 Speed meter 23 Wheel 24 Magnet 25 Proximity sensor

Claims (2)

A traveling carriage having traveling wheels, an engine mounted on the traveling carriage, a hydraulic pump driven by the engine, a hydraulic motor that drives the traveling wheels, a charge pump that replenishes the amount of oil leaked in a closed circuit, and a closed circuit A control work vehicle equipped with a relief valve for controlling the internal pressure, and an electromagnetic valve for supplying or shutting off the charge pressure from the charge pump to the pilot port for high-speed / low-speed switching of the hydraulic motor, wherein the hydraulic motor has two stages of large and small This is a hydraulic motor that can be switched to the capacity of the vehicle, and that switching can be performed when the speed of the management work vehicle becomes lower than the slow speed. If the number of revolutions increases, the generator that increases the amount of power generation, the voltage from the generator is detected, and it corresponds to the slow speed of the traveling carriage When the comparator, A contact relay, hydraulic motor changeover switch, and changeover switch are switched to the high speed side, the first coil is energized and the main contact is energized and switched in reverse. When the switch is turned to the low speed side, the second coil is excited, the main contact is shut off and the state is maintained, a self-holding relay that supplies the charge pump charge pressure to the hydraulic motor when energized and shuts off when energization is stopped A management work vehicle characterized by further comprising a solenoid of a solenoid valve that performs the switching in the following procedure: power generation that generates rotational power in conjunction with a traveling wheel when the speed of the traveling carriage is lower than the slow speed The comparator senses that the amount of power generated by the device has dropped and the voltage has dropped, and an output signal is output, and the coil of the A contact relay is excited, Energized contacts of laser is then put a changeover switch to the low speed side, the second coil is interrupted main contact is energized, the solenoid hydraulic motor not excited becomes large motor. A traveling carriage having traveling wheels, an engine mounted on the traveling carriage, a hydraulic pump driven by the engine, a hydraulic motor that drives the traveling wheels, a charge pump that replenishes the amount of oil leaked in a closed circuit, and a closed circuit A control work vehicle equipped with a relief valve for controlling the internal pressure, and an electromagnetic valve for supplying or shutting off the charge pressure from the charge pump to the pilot port for high-speed / low-speed switching of the hydraulic motor, wherein the hydraulic motor has two stages of large and small This is a hydraulic motor that can be switched to the capacity of the vehicle. In the management work vehicle that can be switched when the speed of the management work vehicle becomes lower than the slow speed, the rotation of the traveling wheel 21 of the traveling carriage is sensed and a pulse is generated. The pulse meter to be generated, the FV converter that can convert the pulse generated by the pulse meter into a voltage, and the voltage from the FV converter The first coil is energized when the comparator, A contact relay, hydraulic motor changeover switch, and changeover switch are switched to the high speed side. When the main contact is energized and the changeover switch is turned to the low speed side, the second coil is energized, the main contact is cut off and the self-holding relay that can maintain this state is supplied. When energized, the charge pressure of the charge pump is supplied to the hydraulic motor. And further comprising a solenoid of a solenoid valve that shuts off the energization when the power is turned off, and the switching is performed according to the following procedure: when the speed of the traveling carriage is lower than the slow speed, the traveling The pulse generated in conjunction with the rotation of the wheel decreases, so the voltage converted by the FV converter decreases and the voltage decreases. The sensor senses, the output signal is output, the coil of the A contact relay is excited, the contact of the A contact relay is energized, and then when the changeover switch is turned to the low speed side, the second coil is excited and the main contact is cut off, The solenoid is not excited and the hydraulic motor becomes a large capacity motor.

Images