JP4559663B2 - Drive control device for cooling fan - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling fan mounted on a vehicle, and more particularly to an arrangement relationship with other devices when switching the rotation direction of the cooling fan.
[0002]
[Prior art]
Heat generated by the engine of a vehicle such as a construction machine is dissipated by the radiator. The radiator is cooled by being blown by a hydraulic drive fan. The hydraulic drive fan is driven to rotate by a hydraulic motor. The fan used for cooling the radiator only needs to be able to rotate in one direction.
[0003]
The direction of rotation differs depending on the type of fan. Therefore, conventionally, a switching valve that switches the rotation direction of the hydraulic motor and switches the rotation direction of the fan according to the type of fan is provided.
[0004]
Therefore, if the fan can be rotated reversely using this switching valve, the clogging of the radiator can be prevented by blowing off the dust clogged in the radiator.
[0005]
Other techniques for preventing clogging of the radiator include the following.
[0006]
1) Stop the engine and clean the garbage stuck in the radiator with a washer.
[0007]
2) A mechanism for changing the mounting angle of the fan is provided, and the blowing direction is reversed by changing the mounting angle of the fan, so that the dust stuck in the radiator is blown away (JP-A-8-303199, JP-A-8-312588). Gazette).
[0008]
However, when the technique of 1) is employed, the engine must be stopped and the washing machine must be handled, so that there is a problem that the worker can take a lot of time and effort.
[0009]
Further, when the technique 2) is adopted, a complicated mechanism must be mounted on the fan, so that the cost increases and the reliability decreases due to insufficient strength.
[0010]
For this reason, a technique using a switching valve for switching the rotation direction of the hydraulic motor has been adopted.
[0011]
[Problems to be solved by the invention]
In recent years, vehicles such as construction machines are required to be compact in size, and the installation space for hydraulic equipment is greatly limited accordingly. Therefore, it is required to arrange hydraulic equipment without taking up space in a limited installation space within the vehicle body. Further, when providing the switching valve, it is required to simplify the structure, reduce the number of parts such as piping, and keep the apparatus cost low.
[0012]
Therefore, according to the present invention, when the rotation direction of the cooling fan is switched by the switching valve, the device can be installed without taking up space in a narrow installation space in the vehicle body, the structure is simplified, and the number of parts such as piping is reduced. The problem to be solved is to reduce the cost of the apparatus.
[0013]
[Means, actions and effects for solving the problems]
The first invention is
A cab (21), an engine (5), a radiator (23), and a cooling fan (36) are arranged in the vehicle (20), and the rotation of the cooling fan (36) is driven and controlled. In the cooling fan drive control apparatus configured to cool the radiator (23),
An engine (5), a radiator (23), and a cooling fan (36) are sequentially arranged on one side with respect to the cab (21),
A switching valve (12, 120) for switching the rotation direction of the cooling fan (36) is provided;
The switching valve (12, 120) is disposed close to the cooling fan (36);
Switching the direction of rotation of the cooling fan (36) by switching the switching valve (12, 120).
It is characterized by.
[0014]
The first invention will be described with reference to FIGS.
[0015]
As shown in FIG. 1, the engine 5, the radiator 23, and the cooling fan 36 are sequentially arranged on one side with respect to the cab 21.
[0016]
As shown in FIG. 4, the switching valve 12 that switches the rotation direction of the cooling fan 36 is disposed in the vicinity of the cooling fan 36.
[0017]
As shown in FIG. 1A, when the switching valve 12 is switched to the normal rotation position and the cooling fan 36 rotates in the normal rotation direction, the radiator 23 is cooled. Further, as shown in FIG. 1B, when the switching valve 12 is switched to the reverse rotation position and the cooling fan 36 rotates in the reverse rotation direction, the dust stuck in the radiator 23 can be blown off. Since the cooling fan 36 rotates in the reverse direction, warm air in the engine compartment 22 is blown to the cab 21 side, so that the cab 21 can be heated without providing a heater or the like.
[0018]
According to the first aspect of the invention, the switching valve 12 is arranged in the vicinity of the cooling fan 36, so that the motor body 11 that houses the cooling fan 36 and the switching valve 12, as shown in FIG. Thus, the length in the vehicle longitudinal direction X can be shortened, and equipment can be installed in a small installation space in the vehicle 20 without taking up space.
[0019]
Further, since the switching valve 12 is arranged close to the cooling fan 36, the structure is simplified, the number of parts such as pipes and joints can be reduced, and the apparatus cost can be reduced.
[0020]
The second invention is
A cab (21), an engine (5), a radiator (23), and a cooling fan (36) are disposed in the vehicle (20), and the cooling fan (36) is provided by a hydraulic motor (1). In the drive control device for the cooling fan, wherein the radiator (23) is cooled by controlling the rotation of the fan.
An engine (5), a radiator (23), and a cooling fan (36) are sequentially arranged on one side with respect to the cab (21),
A switching valve (12, 120) for switching the rotational direction of the hydraulic motor (1) is provided;
The switching valve (12, 120) is built in the body (11) of the hydraulic motor (1),
Switching the direction of rotation of the cooling fan (36) by switching the switching valve (12, 120).
It is characterized by.
[0021]
The second invention will be described with reference to FIGS.
[0022]
As shown in FIG. 1, the engine 5, the radiator 23, and the cooling fan 36 are sequentially arranged on one side with respect to the cab 21.
[0023]
As shown in FIG. 4, the switching valve 12 that switches the rotation direction of the cooling fan 36 is built in the motor body 11 of the hydraulic motor 1 that rotationally drives the cooling fan 36.
[0024]
As shown in FIG. 1A, when the switching valve 12 is switched to the normal rotation position and the cooling fan 36 rotates in the normal rotation direction, the radiator 23 is cooled. Further, as shown in FIG. 1B, when the switching valve 12 is switched to the reverse rotation position and the cooling fan 36 rotates in the reverse rotation direction, the dust stuck in the radiator 23 can be blown off. Since the cooling fan 36 rotates in the reverse direction, warm air in the engine compartment 22 is blown to the cab 21 side, so that the cab 21 can be heated without providing a heater or the like. Further, warming up of the engine 5 can be accelerated.
[0025]
According to the second invention, since the switching valve 12 is built in the motor body 11 of the hydraulic motor 1, as shown in FIG. 4, the motor body 11 including the cooling fan 36 and the switching valve 12. Thus, the length in the vehicle longitudinal direction X can be shortened, and equipment can be installed in a small installation space in the vehicle 20 without taking up space.
[0026]
Further, since the switching valve 12 is built in the motor body 11 of the hydraulic motor 1, the structure is simpler than the case where the switching valve 12 and the hydraulic motor 1 are separate, and the number of parts such as pipes and joints is reduced. Can be reduced, and the apparatus cost can be kept low.
[0027]
The third invention is the first invention or the second invention,
The engine (5) is arranged so that its longitudinal direction coincides with the vehicle width direction
It is characterized by.
[0028]
According to the third invention, as shown in FIG. 2, since the engine 5 is arranged so that its longitudinal direction coincides with the vehicle width direction Y, the length in the vehicle longitudinal direction X can be further shortened. Equipment can be installed without taking up space in a small installation space.
[0029]
4th invention is 1st invention or 2nd invention,
The center of rotation (32) of the cooling fan (36) is formed in a recess, and the drive unit (11) including the switching valve (12, 120) is accommodated in the recess.
It is characterized by.
[0030]
According to the fourth invention, as shown in FIG. 4, the boss portion 32 as the rotation center portion of the cooling fan 36 is formed in the recess, and the motor body 11 including the switching valve 12 is accommodated in the recess. The total length in the vehicle longitudinal direction X of the cooling fan 36 and the motor body 11 is shorter than the conventional one by ΔX, and the device is installed without taking up space in a small installation space in the vehicle 20. It becomes possible.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a cooling fan drive control device according to the present invention will be described below. In the present embodiment, it is assumed that a cooling fan is mounted on a construction machine such as a bulldozer, a wheel loader, a dump truck, or a hydraulic excavator. However, the present invention is not limited to a construction machine, and can also be applied to a case where a cooling fan is mounted on a vehicle such as another work machine or a general automobile. In the present embodiment, a hydraulically driven fan that is hydraulically driven is assumed as the cooling fan. However, the present invention is not limited to a hydraulically driven fan, but can be applied to an electric fan.
[0032]
FIG. 1 shows the arrangement relationship of each device mounted on the vehicle 20 of the embodiment.
[0033]
In FIG. 1, the longitudinal direction of the vehicle 20 is X, and the vehicle width direction is Y. The vehicle 20 includes a crawler belt 24, and the crawler belt 24 rotates to travel in the longitudinal direction X.
[0034]
That is, as shown in FIG. 1, the engine 5, the radiator 23, and the cooling fan 36 are sequentially arranged on one side with respect to the cab 21 of the vehicle 20.
[0035]
FIG. 4 shows an arrangement relationship between the cooling fan 36 and the motor body 11 as a drive unit that drives the cooling fan 36.
[0036]
As shown in FIG. 4, the cooling fan 36 is mainly composed of a boss portion 32 as a rotation center portion and a blade portion 30. The boss part 32 and the blade part 30 are connected by being fastened by a bolt 31.
[0037]
The boss part 30 is formed in a concave part. The motor body 11 is accommodated in the boss 30 formed in the recess. A hydraulic motor 1 is built in the motor body 11 and a switching valve 12 described later is built in. The switching valve 12 is a control valve that switches the rotation direction of the hydraulic motor 1 between a normal rotation direction and a reverse rotation direction.
[0038]
The rotating shaft of the hydraulic motor 1 is fixed to the boss portion 32 of the cooling fan 36.
[0039]
For this reason, the cooling fan 36 rotates when the hydraulic motor 1 is driven to rotate. Further, the rotation direction of the cooling fan 36 is switched by switching the rotation direction of the hydraulic motor 1 by the switching valve 12.
[0040]
A pipe 33 that supplies pressure oil to the switching valve 12 and discharges the pressure oil from the switching valve 12 is connected to the motor body 11.
[0041]
Thus, the switching valve 12 is provided in the vicinity of the cooling fan 36. Moreover, a switching valve 12 is built in the motor body 11.
[0042]
For this reason, the drive unit which drives the cooling fan 36 can be made compact, and a simple structure can be achieved. Furthermore, since the motor body 11 incorporating the switching valve 12 is accommodated in the boss portion 32 of the cooling fan 36, the total length of the cooling fan 36 and the motor body 11 can be shortened. .
[0043]
Comparison is made with the conventional apparatus configuration using FIG. According to the conventional configuration, the boss portion 32 of the cooling fan 36 is not formed in the recess. For this reason, the total length in the vehicle longitudinal direction X of the cooling fan 36 and the motor body 11 ′ is long. Moreover, since the motor body 11 ′ and the switching valve 12 are separate bodies, an extra space is provided by the amount corresponding to the switching valve 12.
[0044]
On the other hand, according to the present embodiment, since the motor body 11 is accommodated in the boss portion 32 of the cooling fan 36, the cooling fan 36 and the motor body 11 are added in the vehicle longitudinal direction X. The length is shorter by ΔX than the conventional one. Further, since the switching valve 12 is built in the motor body 11, no further space is required.
[0045]
Thus, according to the present embodiment, the cooling fan 36, the hydraulic motor 1, and the switching valve 12 can be installed in a small installation space in the vehicle 20 without taking up space.
[0046]
Further, since the switching valve 12 is built in the motor body 11, the structure is simpler than the case where the switching valve 12 and the hydraulic motor 1 are separate, and the number of parts such as pipes and joints can be reduced. Cost can be kept low.
[0047]
The rotation switching control of the cooling fan 36 can be performed by either open loop control or closed control (feedback control).
[0048]
When switching control is performed by open loop control, a timer such as a timer is provided. The contents of the control for switching the rotation direction of the cooling fan 36 will be described with reference to FIG.
[0049]
FIG. 10 shows a time chart of the embodiment. In FIG. 10, the horizontal axis indicates time, and the vertical axis indicates “forward rotation”, “rotation stop”, and “reverse rotation”.
[0050]
That is, until the time T1 (for example, 15 minutes) is counted by the timer, the switching valve 12 is positioned in the forward rotation position, and the cooling fan 36 rotates forward for the time T1. When T1 is timed by the timer, the rotational drive of the hydraulic motor 1 is stopped as will be described later. The rotation drive of the hydraulic motor 1 is stopped until T2 (for example, 10 seconds to 10 and several seconds) is counted by the timer, and the rotation of the cooling fan 36 is stopped for the time T2. When T2 is counted by the timer, the switching valve 12 is switched to the reverse rotation position. Until the time T3 (for example, 2 to 3 minutes) is counted by the timer, the switching valve 12 is positioned in the reverse rotation position, and the cooling fan 36 rotates reversely for the time T3.
[0051]
The above process is repeatedly executed.
[0052]
Here, when the cooling fan 36 is switched from the normal rotation to the reverse rotation or from the reverse rotation to the normal rotation, the rotational drive of the hydraulic motor 1 is stopped only for a predetermined time T2 to prevent cavitation. This is to prevent the generation of abnormal noise.
[0053]
When switching control is performed by feedback control, an air volume detection sensor that detects the passing air volume that passes through the radiator 23 is provided. Therefore, a threshold value is set for the detection value of the air volume detection sensor. This threshold value is set to a value that can determine whether or not the radiator 23 is clogged with dust.
[0054]
If the air volume detected by the air volume detection sensor is equal to or greater than the above threshold value, it is determined that the radiator 23 is not clogged with dust, and the switching position of the switching valve 12 is maintained at the normal rotation position and cooling is performed. The fan 36 maintains a normal rotation.
[0055]
However, when the air volume detected by the air volume detection sensor becomes smaller than the above threshold value, it is determined that the radiator 23 is clogged with dust, and the rotational driving of the hydraulic motor 1 is stopped for a predetermined time T2. After that, the switching position of the switching valve 12 is switched to the reverse rotation position, and the cooling fan 36 rotates reversely.
[0056]
Therefore, when the air volume detected by the air volume detection sensor is equal to or greater than the threshold value, the rotational drive of the hydraulic motor 1 is stopped for a predetermined time T2, and then the switching position of the switching valve 12 is switched to the normal rotation position. The cooling fan 36 rotates forward.
[0057]
When switching control is performed by feedback control, the cooling fan 36 rotates in the reverse direction for the minimum necessary time, so that the cooling efficiency of the radiator 23 is improved as compared with the open loop control.
[0058]
FIG. 1 shows the flow of wind accompanying the rotation of the cooling fan 36.
[0059]
As shown in FIG. 1A, when the switching valve 12 is switched to the forward rotation position and the cooling fan 36 rotates in the forward rotation direction, the air passing through the radiator 23 is sucked into the cooling fan 36 as indicated by the arrows. The air is discharged in front of the vehicle 20. Thereby, the radiator 23 is cooled.
[0060]
As shown in FIG. 1B, when the switching valve 12 is switched to the reverse rotation position and the cooling fan 36 rotates in the reverse rotation direction, the air in front of the vehicle 20 is transferred to the cooling fan 36 as indicated by the arrow. The air is sucked and discharged toward the radiator 23. As a result, it is possible to blow away the dust stuck in the radiator 23. At this time, warm air in the engine compartment 22 is blown toward the cab 21 side. For this reason, the warm air in the engine compartment 22 can be introduced into the cab 21 by providing a vent hole in the wall 25 that partitions the engine compartment 22 and the cab 21. For this reason, the inside of the cab 21 can be heated without providing a heater or the like. Further, warming up of the engine 5 can be accelerated.
[0061]
In FIG. 1, the engine 5 is arranged so that its longitudinal direction coincides with the vehicle longitudinal direction X. However, as shown in FIG. 2, the engine 5 is arranged so that its longitudinal direction coincides with the vehicle width direction Y. May be. When such an arrangement is taken, the length of the engine compartment 22 in the vehicle longitudinal direction X can be further shortened, and various devices can be installed in a small installation space in the vehicle 20 without taking up space. It becomes possible.
[0062]
Further, as shown in FIG. 3, the engine chamber 22, the radiator chamber 27, and the wall 26 may be used for partitioning. The engine 5 is disposed in the engine chamber 22, and the radiator 23 and the cooling fan 36 are disposed in the radiator chamber 27.
[0063]
FIG. 5 shows the hydraulic circuit of the first embodiment.
[0064]
As shown in FIG. 5, the apparatus of the embodiment is largely controlled to switch the rotational direction of the pump body 110 of the hydraulic pump 2, the motor body 11 of the hydraulic motor 1, the cooling fan 36, and the cooling fan 36. And a controller 37.
[0065]
The hydraulic pump 2 is a variable displacement hydraulic pump. However, implementation using a constant displacement hydraulic pump is also possible.
[0066]
The hydraulic pump 2 is driven by the engine 5 and discharges the pressure oil to the pump discharge oil passage 7. The electromagnetic proportional control valve 38 guides the pilot pressure corresponding to the electrical command signal output from the controller 37 to the swash plate drive unit 39. The swash plate drive unit 39 drives the swash plate 2 a of the hydraulic pump 2 in accordance with the pilot pressure introduced from the electromagnetic proportional control valve 38 to change the capacity of the hydraulic pump 2.
[0067]
The pump discharge oil passage 7 is connected to the pump port P of the switching valve 12 via the switching valve 40.
[0068]
The switching valve 40 is a two-position switching valve having a pressure oil supply position 40a and a pressure oil cutoff position 40b. The switching valve 40 is built in the pump body 110.
[0069]
The electromagnetic proportional control valve 41 guides the pilot pressure corresponding to the electrical command signal output from the controller 37 to the pilot port 40 c of the switching valve 40.
[0070]
The valve position of the switching valve 40 changes according to the pilot pressure acting on the pilot port 40c. When the switching valve 40 is switched to the pressure oil supply position 40a, the pressure oil discharged from the hydraulic pump 2 passes through the switching valve 40 and is supplied to the pump port P of the switching valve 12. When the switching valve 40 is switched to the pressure oil cutoff position 40b, the pressure oil discharged from the hydraulic pump 2 is shut off by the switching valve 40 and discharged to the tank 3 without being supplied to the pump port P of the switching valve 12.
[0071]
The switching valve 12 and the pressure oil supply / discharge ports MA and MB of the hydraulic motor 1 are connected by oil passages 74 and 75, respectively.
[0072]
The switching valve 12 inputs the pump discharge pressure oil through the oil passage 7, controls the direction of the pressure oil, and supplies the pressure oil to the port MA or the port MB of the hydraulic motor 1.
[0073]
The switching valve 12 is a two-position switching valve having a forward rotation position A and a reverse rotation position B. The switching valve 12 is built in the motor body 11 as described above.
[0074]
The electromagnetic proportional control valve 42 is a two-position switching valve having a low pressure position 42a and a high pressure position 42b. The electromagnetic proportional control valve 42 is switched in valve position in accordance with an electrical command signal output from the controller 37. When the electromagnetic proportional control valve 42 is switched to the high pressure position 42b, the high pump discharge pressure in the pump discharge oil passage 7 is guided to the pilot port 12c of the changeover valve 12 through the oil passage 44 as a pilot pressure. When the electromagnetic proportional control valve 42 is switched to the low pressure position 42a, the pilot port 12c of the switching valve 12 communicates with the tank 3 and a low pressure pilot pressure acts on the pilot port 12c of the switching valve 12.
[0075]
The switching valve 12 is positioned at the forward rotation position A when a low pilot pressure is applied to the pilot port 12c, and is positioned at the reverse rotation position B when a high pilot pressure is applied to the pilot port 12c.
[0076]
When the switching valve 12 is positioned at the normal rotation position A, pressure oil is supplied to the port MA of the hydraulic motor 1 and the hydraulic motor 1 rotates in the forward direction. When the switching valve 12 is positioned at the reverse rotation position B, pressure oil is supplied to the port MB of the hydraulic motor 1 and the hydraulic motor 1 rotates in the reverse direction.
[0077]
A suction valve 13 and a safety valve 4 are arranged on the upstream side of the switching valve 12.
[0078]
The suction valve 13 is built in the motor body 11. The safety valve 4 is built in the pump body 110.
[0079]
The tank port T of the switching valve 12 communicates with the oil passage 6. The oil passage 6 and the pump discharge oil passage 7 are communicated with each other by an oil passage 8.
[0080]
A suction valve 13 is provided in the oil passage 8, and the suction valve 13 guides the pressure oil discharged from the tank port T of the switching valve 12 only in the direction from the oil passage 6 to the pump discharge oil passage 7.
[0081]
The pump discharge oil passage 7 is branched into an oil passage 9, and a safety valve 4 is provided on the oil passage 9. The safety valve 4 guides the pressure oil to the tank 3 when the hydraulic pressure in the pump discharge oil passage 7 becomes equal to or higher than a set pressure.
[0082]
Next, operations performed in the first embodiment shown in FIG. 5 will be described.
[0083]
When switching the cooling fan 36 in the forward rotation direction, an electrical command signal for positioning the switching valve 40 at the pressure oil supply position 40a is output from the controller 37 to the electromagnetic proportional control valve 41, and the electromagnetic proportional control valve 42 is set to a low pressure. An electric command signal for positioning the switching valve 12 to the normal rotation position A by positioning it at the position 42 a is output to the electromagnetic proportional control valve 42.
[0084]
When the switching valve 40 is positioned at the pressure oil supply position 40a and the switching valve 12 is positioned at the normal rotation position A, the pressure oil discharged from the hydraulic pump 2 passes through the pump discharge oil passage 7, the switching valve 40, and the switching valve 12. Then, the oil is supplied to the port MA of the hydraulic motor 1 through the oil passage 74.
As a result, the hydraulic motor 1 rotates forward and the cooling fan 36 rotates in the forward direction.
[0085]
When stopping the rotational drive of the hydraulic motor 1, an electrical command signal for causing the switching valve 40 to be positioned at the pressure oil cutoff position 40 b is output from the controller 37 to the electromagnetic proportional control valve 41.
[0086]
When the switching valve 40 is positioned at the pressure oil shut-off position 40b, the pressure oil discharged from the hydraulic pump 2 is shut off by the switch valve 40, and no pressure oil is supplied to the pump port P of the switch valve 12. For this reason, no pressure oil is supplied to any of the ports MA and MB of the hydraulic motor 1.
[0087]
The hydraulic motor 1 continues to rotate due to the driving force received from the load and the inertia of the hydraulic motor 1 itself. At this time, the hydraulic motor 1 performs a pumping action for discharging pressure oil from the port MB. For this reason, the pressure oil in the oil passage 6 communicating with the port MB is higher than that in the pump discharge oil passage 7. At this time, the high pressure oil in the oil passage 6 is led to the pump discharge oil passage 7 via the suction valve 13 on the oil passage 8. For this reason, the high pressure oil is sucked into the port MA of the hydraulic motor 1.
[0088]
When switching the cooling fan 36 in the reverse rotation direction, an electrical command signal for positioning the switching valve 40 at the pressure oil supply position 40a is output from the controller 37 to the electromagnetic proportional control valve 41, and the electromagnetic proportional control valve 42 is set to high pressure. An electric command signal for positioning the switching valve 12 in the reverse rotation position B by positioning it at the position 42 b is output to the electromagnetic proportional control valve 42.
[0089]
When the switching valve 40 is positioned at the pressure oil supply position 40a and the switching valve 12 is positioned at the reverse rotation position B, the pressure oil discharged from the hydraulic pump 2 passes through the pump discharge oil passage 7, the switching valve 40, and the switching valve 12. Then, the oil is supplied to the port MB of the hydraulic motor 1 through the oil passage 75.
As a result, the hydraulic motor 1 rotates in the reverse direction, and the cooling fan 36 rotates in the reverse direction.
[0090]
Next, a structural example of the hydraulic motor 1 according to the first embodiment will be described with reference to FIGS.
[0091]
FIG. 6 is a cross-sectional view of the motor body 11 of the hydraulic motor 1.
[0092]
7 is a cross-sectional view of the motor body 11 shown in FIG.
[0093]
As shown in FIG. 7, the spool 10 of the switching valve 12 is slidably accommodated in the motor body 11. A pilot pressure acts on the pilot port 12 c on the right side of the spool 10 in the drawing via an electromagnetic proportional control valve 42.
[0094]
The operation of FIG. 7 will be described.
[0095]
When a low pilot pressure is acting on the pilot port 12c of the spool 10 via the electromagnetic proportional control valve 42, the spool 10 is positioned on the right side as shown. In this position, the pump port P communicates with the port MA and the port MB communicates with the tank port T. Therefore, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MA of the hydraulic motor 1 through the pump discharge oil passage 7 and the opening of the spool 10. As a result, the hydraulic motor 1 rotates forward.
[0096]
When high pilot pressure in the oil passage 7 is acting on the pilot port 12c of the spool 10 via the electromagnetic proportional control valve 42, the spool 10 moves to the left from the illustrated position. When the spool 10 is located on the left side in the figure, the pump port P communicates with the port MB, and the port MA communicates with the tank port T. Therefore, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MB of the hydraulic motor 1 through the pump discharge oil passage 7 and the opening of the spool 10. As a result, the hydraulic motor 1 rotates in the reverse direction.
[0097]
As described above, according to the first embodiment, the switching valve 40 is controlled to be switched to the pressure oil supply position 40a and the pressure oil cutoff position 40b, and the switching valve 12 is switched to the normal rotation position A and the reverse rotation position B. Thus, when the forward / reverse rotation of the cooling fan 36 is switched, the rotation drive of the hydraulic motor 1 can be stopped without stopping the engine 5 and the rotation of the cooling fan 36 can be stopped. For this reason, when the forward / reverse rotation of the cooling fan 36 is switched, a troublesome operation of temporarily stopping the engine 5 and starting the engine 5 again becomes unnecessary, and work efficiency can be improved.
In the first embodiment described above, the switching valve 40 is provided separately from the switching valve 12 in the motor body 11. Next, a second embodiment in which the switching valve 40 is unnecessary will be described.
[0098]
FIG. 8 shows a hydraulic circuit according to the second embodiment. Hereinafter, in FIG. 8, the same reference numerals as those in the first embodiment of FIG.
[0099]
As shown in FIG. 8, the pump discharge oil passage 7 is connected to the pump port P of the switching valve 120.
[0100]
The switching valve 120 corresponds to the switching valve 12 described above, and similarly to the switching valve 12, the pump discharge pressure oil is input via the oil passage 7 to control the direction of the pressure oil and the port MA of the hydraulic motor 1. Or pressure oil is supplied to port MB.
[0101]
The switching valve 120 is a three-position switching valve having a stop position C in addition to a forward rotation position A and a reverse rotation position B.
[0102]
The electromagnetic proportional control valve 42 is a two-position switching valve having a low pressure position 42a and a high pressure position 42b. The electromagnetic proportional control valve 42 is switched in valve position in accordance with an electrical command signal output from the controller 37. When the electromagnetic proportional control valve 42 is switched to the high pressure position 42b, the high pump discharge pressure in the pump discharge oil passage 7 is guided to the pilot port 120c of the changeover valve 120 via the oil passage 44 as a pilot pressure. When the electromagnetic proportional control valve 42 is switched to the low pressure position 42a, the pilot port 120c of the switching valve 120 communicates with the tank 3 and a low pressure pilot pressure acts on the pilot port 120c of the switching valve 120.
[0103]
A rod 45 is provided on the side of the switching valve 120 facing the pilot port 120c. The rod 45 operates according to the pilot pressure acting on the pilot port 45c, and applies a force opposed to the pilot pressure acting on the pilot port 120c to the switching valve 120.
[0104]
The electromagnetic proportional control valve 43 is a two-position switching valve having a low pressure position 43a and a high pressure position 43b. The electromagnetic proportional control valve 43 is switched in valve position in accordance with an electrical command signal output from the controller 37. When the electromagnetic proportional control valve 43 is switched to the high pressure position 43b, the high pump discharge pressure in the pump discharge oil passage 7 is guided to the pilot port 45c of the rod 45 as a pilot pressure. When the electromagnetic proportional control valve 43 is switched to the low pressure position 43a, the pilot port 45c of the rod 45 communicates with the tank 3, and a low pressure pilot pressure acts on the pilot port 45c of the rod 45.
[0105]
The switching valve 120 is positioned in the forward rotation position A when a low pilot pressure acts on the pilot port 120 c and a high pilot pressure acts on the pilot port 45 c of the rod 45. The switching valve 120 is positioned at the reverse rotation position B when a high pilot pressure acts on the pilot port 120c and a low pilot pressure acts on the pilot port 45c of the rod 45. The switching valve 120 is positioned at the stop position C when a high pilot pressure acts on the pilot port 120c and a high pilot pressure acts on the pilot port 45c of the rod 45.
[0106]
When the switching valve 120 is positioned at the normal rotation position A, pressure oil is supplied to the port MA of the hydraulic motor 1 and the hydraulic motor 1 rotates in the positive direction. When the switching valve 120 is located at the reverse rotation position B, pressure oil is supplied to the port MB of the hydraulic motor 1 and the hydraulic motor 1 rotates in the reverse direction.
[0107]
When the switching valve 120 is located at the stop position C, pressure oil is supplied to both the ports MA and MB of the hydraulic motor 1. At this time, the ports MA and MB both communicate with the tank 3.
[0108]
Next, operations performed in the second embodiment shown in FIG. 8 will be described.
[0109]
When switching the cooling fan 36 in the forward rotation direction, the controller 37 causes the electromagnetic proportional control valve 42 to be positioned at the low pressure position 42a, the electromagnetic proportional control valve 43 is positioned at the high pressure position 43b, and the switching valve 120 is moved to the normal rotation position. An electric command signal for positioning A is output to the electromagnetic proportional control valves 42 and 43.
[0110]
When the switching valve 120 is positioned at the normal rotation position A, the pressure oil discharged from the hydraulic pump 2 passes through the pump discharge oil passage 7 and the switching valve 120 and is supplied to the port MA of the hydraulic motor 1 through the oil passage 74. The As a result, the hydraulic motor 1 rotates forward and the cooling fan 36 rotates in the forward direction.
[0111]
When stopping the rotational driving of the hydraulic motor 1, the controller 37 causes the electromagnetic proportional control valve 42 to be positioned at the high pressure position 42b, the electromagnetic proportional control valve 43 to be positioned at the high pressure position 43b, and the switching valve 120 to the stop position C. An electrical command signal to be positioned is output to the electromagnetic proportional control valves 42 and 43.
[0112]
When the switching valve 120 is located at the stop position C, the pressure oil discharged from the hydraulic pump 2 is supplied to both ports MA and MB of the hydraulic motor 1. At this time, the ports MA and MB of the hydraulic motor 1 communicate with the tank 3. As a result, the rotational drive of the hydraulic motor 1 is stopped, and the rotation of the cooling fan 3 is stopped.
[0113]
When switching the cooling fan 36 to the reverse rotation direction, the controller 37 causes the electromagnetic proportional control valve 42 to be positioned at the high pressure position 42b, the electromagnetic proportional control valve 43 to be positioned at the low pressure position 43a, and the switching valve 120 to be reverse rotation position. An electric command signal for positioning B is output to the electromagnetic proportional control valves 42 and 43.
[0114]
When the switching valve 120 is positioned at the reverse rotation position B, the pressure oil discharged from the hydraulic pump 2 passes through the pump discharge oil passage 7 and the switching valve 120 and is supplied to the port MB of the hydraulic motor 1 through the oil passage 75. The As a result, the hydraulic motor 1 rotates in the reverse direction and the cooling fan 36 rotates in the reverse direction.
[0115]
Next, a structural example of the hydraulic motor 1 according to the second embodiment will be described with reference to FIG.
[0116]
FIG. 9 is a cross-sectional view of the motor body 11 shown in FIG.
[0117]
As shown in FIG. 9, the spool 100 of the switching valve 120 is slidably accommodated in the motor body 11. A pilot pressure is applied to the pilot port 120 c on the right side of the spool 100 in the drawing via the electromagnetic proportional control valve 42. A pilot pressure acts on the pilot port 45 c of the rod 45 on the left side of the spool 100 in the drawing via an electromagnetic proportional control valve 43.
[0118]
The operation of FIG. 9 will be described.
[0119]
A low pilot pressure acts on the pilot port 120c of the spool 100 via the electromagnetic proportional control valve 42, and a high pilot pressure in the oil passage 7 acts on the pilot port 45c of the rod 45 via the electromagnetic proportional control valve 43. Is acting, the spool 100 is positioned on the right side as shown. In this position, the pump port P communicates with the port MA and the port MB communicates with the tank port T. Accordingly, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MA of the hydraulic motor 1 through the pump discharge oil passage 7 and the opening of the spool 100. As a result, the hydraulic motor 1 rotates forward.
[0120]
The high pilot pressure in the oil passage 7 acts on the pilot port 120c of the spool 100 via the electromagnetic proportional control valve 42, and the high pilot pressure in the oil passage 7 acts also on the pilot port 45c of the rod 45. In this case, the spool 100 moves from the position shown in the drawing to the left and is positioned at the neutral position. When the spool 100 is positioned at the neutral position on the left side in the figure, the pump port P communicates with both the ports MA and MB, and both the ports MA and MB communicate with the tank port T. Thereby, the rotational drive of the hydraulic motor 1 stops.
[0121]
When the high pilot pressure in the oil passage 7 acts on the pilot port 120c of the spool 100 and the low pilot pressure acts on the pilot port 45c of the rod 45 via the electromagnetic proportional control valve 42, the spool 100 moves further to the left from the neutral position described above. When the spool 100 is located further to the left than the neutral position, the pump port P communicates with the port MB and the port MA communicates with the tank port T. Therefore, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MB of the hydraulic motor 1 through the pump discharge oil passage 7 and the opening of the spool 100. As a result, the hydraulic motor 1 rotates in the reverse direction.
[0122]
As described above, according to the second embodiment, the switching valve 120 is controlled to be switched to the normal rotation position A, the stop position C, and the reverse rotation position B, so that the engine 5 Without stopping the rotation of the hydraulic motor 1, the rotation of the cooling fan 36 can be stopped. For this reason, when the forward / reverse rotation of the cooling fan 36 is switched, a troublesome operation of temporarily stopping the engine 5 and starting the engine 5 again becomes unnecessary, and work efficiency can be improved. In addition, according to the second embodiment, the switching valve 40 of the first embodiment is not necessary when switching control is performed, and the structure is further simplified.
[0123]
In the embodiment described above, the description has been made assuming the switching valves 12 and 120 whose valve positions are switched when the spools 10 and 100 are linearly moved. However, a so-called rotary type switching valve in which the valve position is switched by rotating the spool may be used.
[0124]
FIG. 11 shows a hydraulic circuit of a third embodiment in which the switching valve 12 in the first embodiment shown in FIG. 5 is replaced with a rotary type switching valve 121.
[0125]
That is, as shown in FIG. 11, a stepping motor 113 is provided instead of the electromagnetic proportional control valve 42 shown in FIG. A rotating shaft 113 a of the stepping motor 113 is connected to the spool 130 of the switching valve 121.
[0126]
The rotation shaft 113 a of the stepping motor 113 rotates in accordance with an electrical command signal output from the controller 37. As the rotary shaft 113a rotates, the spool 130 of the switching valve 121 rotates. As the spool 130 is positioned at each predetermined rotation angle, the switching valve 121 is located at the forward rotation position A and the reverse rotation position B.
[0127]
When the switching valve 121 is positioned at the normal rotation position A, pressure oil is supplied to the port MA of the hydraulic motor 1 and the hydraulic motor 1 rotates in the positive direction. When the switching valve 121 is located at the reverse rotation position B, pressure oil is supplied to the port MB of the hydraulic motor 1 and the hydraulic motor 1 rotates in the reverse direction.
[0128]
12 is a cross-sectional view of the motor body 11 shown in FIG. FIG. 12A shows a state where the switching valve 121 is located at the normal rotation position A, and FIG. 12B shows a main part where the switching valve 121 is located at the reverse rotation position B.
[0129]
As shown in FIG. 12, the spool 130 of the switching valve 121 is accommodated in the motor body 11 so as to rotate automatically around the axis. The spool 130 is formed with notches 131 and 132.
[0130]
The operation of FIG. 12 will be described.
[0131]
When an electrical command signal for causing the stepping motor 113 to the normal rotation position A is given from the controller 37, the spool 130 is positioned at a rotation angle as shown in FIG. When the spool 130 is positioned at this rotational angle, the pump port P communicates with the port MA via the notch 131 and the port MB communicates with the tank port T via the notch 132. Accordingly, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MA of the hydraulic motor 1 through the pump discharge oil passage 7, the pump port P of the switching valve 121, and the notch 131. As a result, the hydraulic motor 1 rotates forward.
[0132]
When an electrical command signal for causing the stepping motor 113 to move to the reverse rotation position B is given from the controller 37, the spool 130 further rotates clockwise by 90 ° in the drawing from the rotation angle of FIG. It is positioned at a rotation angle as shown in FIG. When the spool 130 is positioned at this rotational angle, the pump port P communicates with the port MB via the notch 131 and the port MA communicates with the tank port T via the notch 132. Accordingly, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MB of the hydraulic motor 1 through the pump discharge oil passage 7, the pump port P of the switching valve 121, and the notch 131. As a result, the hydraulic motor 1 rotates in the reverse direction.
[0133]
The switching valve 12 in the first embodiment shown in FIG. 5 has been described above assuming the case where the rotary type switching valve 121 is replaced. However, the switching valve 120 in the second embodiment shown in FIG. It is possible to replace it with a rotary type switching valve.
[0134]
1 to 3, the engine 5 is arranged on one side with respect to the cab 21. In this case, the arrangement direction of the driver's seat in the cab 21 is arbitrary. The driver's seat may be arranged so that the engine is arranged in front of the operator's line of sight, or the driver's seat may be arranged so that the engine is arranged behind the operator's line of sight.
[Brief description of the drawings]
1A and 1B are layout diagrams of cooling fans.
FIG. 2 is a layout view of cooling fans.
FIG. 3 is a layout view of cooling fans.
FIG. 4 is a cross-sectional view of a cooling fan.
FIG. 5 is a hydraulic circuit diagram of the first embodiment.
FIG. 6 is a cross-sectional view of a hydraulic motor.
7 is a cross-sectional view of the hydraulic motor according to the first embodiment, and is a cross-sectional view taken along the line AA in FIG. 6;
FIG. 8 is a hydraulic circuit diagram of a second embodiment.
FIG. 9 is a cross-sectional view of the hydraulic motor according to the second embodiment, and is a cross-sectional view taken along the line AA of FIG.
FIG. 10 is a diagram illustrating forward / reverse switching control.
FIG. 11 is a hydraulic circuit diagram of a third embodiment.
FIGS. 12A and 12B are cross-sectional views of a hydraulic motor according to a third embodiment.
[Explanation of symbols]
1 Hydraulic motor
5 Engine
11 Motor body
12, 120, 121 selector valve
20 vehicles
21 cab
23 Radiator
32 Boss
36 Cooling fan

Claims (8)

A cab (21), an engine (5), a radiator (23), and a cooling fan (36) are disposed in the vehicle (20), and the cooling fan (36) is provided by a hydraulic motor (1). In the drive control device for the cooling fan, wherein the radiator (23) is cooled by controlling the rotation of the fan.
An engine (5), a radiator (23), and a cooling fan (36) are sequentially arranged on one side with respect to the cab (21),
A hydraulic pump (2) driven by an engine (5);
A two-position switching valve (12) for switching the rotation of the hydraulic motor (1) between two positions of forward rotation and reverse rotation;
A switching valve (40) for switching between a pressure oil supply position for supplying pressure oil supplied from the hydraulic pump (5) to the two-position switching valve (12) and a pressure oil cutoff position for blocking supply of the pressure oil;
With the engine (5) in operation, the switching valve (40) is set to the pressure oil supply position, the two-position switching valve (12) is set to the normal rotation position, the cooling fan (36) is rotated forward, and then the switching valve ( 40) is set to the pressure oil shut-off position to stop the rotation of the cooling fan (36), then the switching valve (40) is set to the pressure oil supply position and the two-position switching valve (12) is set to the reverse rotation position to set the cooling fan ( 36) A cooling fan drive control device comprising control means (41, 42) for reversely rotating 36). A cab (21), an engine (5), a radiator (23), and a cooling fan (36) are disposed in the vehicle (20), and the cooling fan (36) is provided by a hydraulic motor (1). In the drive control device for the cooling fan, wherein the radiator (23) is cooled by controlling the rotation of the fan.
An engine (5), a radiator (23), and a cooling fan (36) are sequentially arranged on one side with respect to the cab (21),
A hydraulic pump (2) driven by an engine (5);
A three-position switching valve (120) for switching the rotation of the hydraulic motor (1) to three positions of forward rotation, reverse rotation and stop;
With the engine (5) in operation, the three-position switching valve (120) is set to the normal rotation position, the cooling fan (36) is rotated forward, and then the three-position switching valve (120) is set to the stop position for cooling. Control means (42, 43) for stopping the rotation of the fan (36) and then reversely rotating the cooling fan (36) with the three-position switching valve (120) in the reverse rotation position. Drive control device for cooling fan. The cooling fan (36) is normally rotated for a predetermined time by a timer, the rotation of the cooling fan (36) is stopped for a predetermined time, and then the cooling fan (36) is reversely rotated for a predetermined time. The cooling fan drive control device according to claim 1 or 2. An air volume detection sensor for detecting an air volume passing through the radiator (23) is provided;
When the detected air volume of the air volume detection sensor becomes smaller than the threshold value while the cooling fan (36) is rotating forward, the cooling fan (36) stops rotating for a predetermined time, and then the cooling fan The drive control device for a cooling fan according to claim 1 or 2, wherein (36) is reversely rotated. 3. The cooling according to claim 1 or 2, wherein the two-position switching valve (12) according to claim 1 or the three-position switching valve (120) according to claim 2 is arranged close to the cooling fan (36). Fan drive control device. The two-position switching valve (12) according to claim 1 or the three-position switching valve (120) according to claim 2 is built in the body (11) of the hydraulic motor (1). Drive control device for cooling fan. 3. The cooling fan drive control device according to claim 1, wherein the engine (5) is arranged such that its longitudinal direction coincides with the vehicle width direction. The rotation center (32) of the cooling fan (36) is formed in a recess, and the drive includes the two-position switching valve (12) of claim 1 or the three-position switching valve (120) of claim 2 in the recess. 3. The cooling fan drive control device according to claim 1, wherein the unit (11) is accommodated.

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