JP4693952B2 - Hydraulic drive device using hydraulic motor and hydraulic motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic drive device using a hydraulic motor. The present invention also relates to the structure of a hydraulic motor.
[0002]
[Prior art]
An engine radiator such as a construction machine is cooled by a hydraulic drive fan. The hydraulic drive fan rotates the fan by rotating the hydraulic motor. The fan used for cooling the radiator only needs to be able to rotate in one direction.
[0003]
However, if the fan can be rotated in the reverse direction, the radiator can be blown away to prevent the radiator from being clogged. For this reason, there is a request to rotate the fan in both directions.
[0004]
Thus, as a hydraulically driven fan device in which the rotation direction of the hydraulic motor is switched between forward and reverse to rotate the fan in both directions, means using a conventional motor drive circuit can be considered.
[0005]
As an example, a hydraulically driven fan device shown in FIG. 10 is assumed.
[0006]
A pump discharge line 56 of the hydraulic pump 58 is connected to the switching valve 51. The switching valve 51 and the check valves 48 and 49 are connected by pipelines 54 and 55, respectively. The check valve 48 is disposed between the pipeline 54 and the pipeline 52 so as to guide the pressure oil discharged from the hydraulic pump 58 only in the direction from the pipeline 54 to the pipeline 52. The check valve 49 is disposed between the pipe line 55 and the pipe line 53 so as to guide the pressure oil discharged from the hydraulic pump 58 only in the direction from the pipe line 55 to the pipe line 53. The check valves 48 and 49 and the pressure oil supply / discharge ports MA and MB of the hydraulic motor 45 are connected by pipes 52 and 53, respectively.
[0007]
The hydraulic motor 45 is equipped with a fan 73 for cooling a radiator (not shown). The fan 73 is rotationally driven according to the rotational driving of the hydraulic motor 45. The switching valve 51 is a valve that controls the direction of the pressure oil discharged from the hydraulic pump 58 and supplies the pressure oil to the port MA or the port MB of the hydraulic motor 45. The switching valve 51 is operated by an operating lever (not shown), and the valve positions A, C, and B of the switching valve 51 are changed. When the switching valve 51 is at the valve position A, pressure oil is supplied to the port MA of the hydraulic motor 45 and the hydraulic motor 45 is rotated (this is defined as normal rotation). When the switching valve 51 is at the valve position B, pressure oil is supplied to the port MB of the hydraulic motor 45 and the hydraulic motor 45 rotates in the reverse direction (this is defined as reverse rotation). When the switching valve 51 is positioned at the valve position C (neutral position), the pressure oil supplied from the hydraulic pump 58 to the hydraulic motor 45 is shut off.
[0008]
Note that the pressure oil discharged from the switching valve 51 is discharged to the tank 59 through the pipe 57.
[0009]
The pipeline 52 and the pipeline 53 are communicated by pipelines 71 and 72.
[0010]
The pipe 71 is provided with a safety valve 46 that guides the pressure oil to the pipe 53 when the hydraulic pressure in the pipe 52 becomes equal to or higher than the set pressure. The pipe 72 is provided with a safety valve 47 that guides the pressure oil to the pipe 52 when the hydraulic pressure of the pipe 53 becomes equal to or higher than the set pressure.
[0011]
The counter balance valve 50 is positioned at the valve position L when the hydraulic pressure in the pipe line 54 becomes higher than the hydraulic pressure in the pipe line 55, and guides the pressure oil in the pipe line 53 to the pipe line 55. On the other hand, the counter balance valve 50 is positioned at the valve position N when the hydraulic pressure in the pipeline 55 becomes higher than the hydraulic pressure in the pipeline 54, and guides the pressurized oil in the pipeline 52 to the pipeline 54. The counter balance valve 50 is positioned at the valve position C (neutral position) when the hydraulic pressure in the pipeline 54 and the hydraulic pressure in the pipeline 55 are the same, and the pressure oil and the pipeline 53 led from the pipeline 52 to the pipeline 54. The pressure oil led to the pipeline 55 from the outside is shut off.
[0012]
The operation performed in the hydraulic circuit shown in FIG. 9 will be described below.
[0013]
Now, the switching valve 51 is assumed to be at the valve position A. Therefore, the pressure oil discharged from the hydraulic pump 58 is supplied to the port MA of the hydraulic motor 45 through the switching valve 51, the pipe 54, the check valve 48, and the pipe 52. At this time, the pressure oil in the pipe line 54 becomes higher than the pressure oil in the pipe line 55. Accordingly, the counter balance valve 50 is positioned at the valve position L. As a result, the pressure oil discharged from the port MB of the hydraulic motor 45 is discharged to the tank 59 via the pipe 53, the counter balance valve 50, the pipe 55, the switching valve 51, and the pipe 57. Thus, the hydraulic motor 45 is rotated forward.
[0014]
Next, it is assumed that the operation lever is operated to stop the rotation of the hydraulic motor 45 from this state, and the switching valve 51 is set to the valve position C (neutral position).
[0015]
Then, the hydraulic motor 45 continues to rotate due to the driving force received from the load and the inertia of the hydraulic motor 45 itself. At this time, the hydraulic motor 45 performs a pumping action for discharging the pressure oil from the port MB. For this reason, the pressure oil in the pipelines 53 and 55 communicating with the port MB becomes higher than the pipelines 52 and 54.
[0016]
The pressurized oil in the pipe line 53 that has become high pressure is guided to the pipe line 52 via the safety valve 47 on the pipe line 72. On the other hand, since the pipe line 55 is high pressure and the pipe line 54 is low pressure, the counter balance valve 50 is set to the valve position N.
[0017]
When the counter balance valve 50 is at the valve position N, the pressure oil in the pipe line 53 is blocked by the suction valve 49 and the counter balance valve 50 at the valve position N. This causes a braking action on the hydraulic motor 45. On the other hand, since the switching valve 51 is at the valve position C, no pressure oil is supplied from the switching valve 51 to any of the ports MA and MB.
[0018]
Therefore, the hydraulic motor 45 stops without rotating in the reverse direction.
[0019]
The same applies to the case where the switching valve 53 is set to the neutral position P while the hydraulic motor 45 is rotated in the reverse direction. A brake force acts on the hydraulic motor 45, and the hydraulic motor 45 stops.
[0020]
As described above, in the conventional hydraulic motor driving apparatus, each auxiliary machine of the hydraulic motor such as the safety valve, the counter balance valve, and the check valve is provided on the downstream side of the switching valve 51.
[0021]
Next, a conventional hydraulically driven fan device constructed using a safety valve and a suction valve will be described with reference to FIG.
[0022]
As shown in FIG. 11, the pressure oil discharge passage 219 of the pump 58 is connected to the switching valve 51. The switching valve 51 and the pressure oil supply / discharge ports MA and MB of the hydraulic motor 45 are connected by a pipe line 205 and a pipe line 206, respectively. The switching valve 51 is a valve that controls the direction of the pressure oil discharged from the pump 58 and supplies it to the pressure oil supply / discharge port MA or the pressure oil supply / discharge port MB of the hydraulic motor 45. When the switching valve 51 is positioned at the valve position A, pressure oil is supplied to the pressure oil supply / discharge port MA of the hydraulic motor 45, and the hydraulic motor 45 rotates in the forward direction (this is defined as forward rotation). When the switching valve 51 is positioned at the valve position B, pressure oil is supplied to the pressure oil supply / discharge port MB of the hydraulic motor 45, and the hydraulic motor 45 rotates in the reverse direction (this is defined as reverse rotation). When the switching valve 51 is positioned at the valve position C (neutral position), the pressure oil supplied from the pump 58 to the hydraulic motor 45 is shut off.
[0023]
The pressure oil supply / discharge port MA of the hydraulic motor 45 and the supply port 212 a of the safety valve 212 are communicated with each other by a pipe line 205 and a pipe line 211. Similarly, the pressure oil supply / discharge port MB of the hydraulic motor 45 and the supply port 212 a of the safety valve 212 are communicated with each other by a pipe line 206 and a pipe line 213. Check valves 207 and 208 for guiding the pressure oil discharged from the hydraulic motor 45 only in the direction on the supply port 212a side of the safety valve 212 are disposed on the pipe lines 211 and 213, respectively. The check valves 207 and 208 are provided to face each other, and the outlets of the check valves 207 and 208 communicate with the supply port 212 a of the safety valve 212. Accordingly, the check valves 207 and 208 select the pressure oil on the high pressure side from the pressure oil supply / discharge ports MA and MB of the hydraulic motor 45 and guide the pressure oil to the inflow port 212 a of the safety valve 212.
[0024]
A spring force by a spring 216 is applied to the safety valve 212. The set pressure of the safety valve 212 is set by the spring force of the spring 216. The discharge port 212 b of the safety valve 212 communicates with the tank 59 via the pressure oil discharge pipe 218.
[0025]
The tank 59 and the pressure oil supply / discharge port MA of the hydraulic motor 45 are communicated with each other by a pipe 218, a suction pipe 215, and a pipe 205. Similarly, the tank 59 and the pressure oil supply / discharge port MB of the hydraulic motor 45 are communicated with each other by a pipe 218, a suction pipe 214, and a pipe 206.
[0026]
Suction valves 210 and 209 are disposed on the suction pipes 215 and 214, respectively, for sucking the pressure oil from the tank 59 and guiding it in the direction of the pressure oil supply / discharge ports MA and MB of the hydraulic motor 45, respectively. The suction valves 210 and 209 are provided to face each other, and downstream sides of the respective suction valves 210 and 209 communicate with the pressure oil supply / discharge ports MA and MB of the hydraulic motor 45. Therefore, the suction valves 210 and 209 select the pressure oil supply / discharge ports MA and MB of the hydraulic motor 45 that have a lower pressure and guide the pressure oil to the hydraulic motor 45.
[0027]
Hereinafter, the operation performed in the hydraulic circuit shown in FIG. 11 will be described.
[0028]
Assume that the pressure oil is supplied to the pressure oil inflow / outflow port MA of the hydraulic motor 45 and the hydraulic motor 45 is rotating forward. In this state, the operation lever is operated to stop the rotation of the hydraulic motor 45 and the switching valve 51 is positioned at the valve position (neutral position) C.
[0029]
Then, the hydraulic motor 45 continues to rotate due to the driving force received from the load and the inertia of the hydraulic motor 45 itself. At this time, the hydraulic motor 45 performs a pumping action for discharging the pressure oil from the pressure oil supply / discharge port MB. For this reason, the pressure oil has a high pressure in the conduit 206 communicating with the pressure oil supply / discharge port MB. The high pressure oil in the pipe line 206 is led to the supply port 212 a of the safety valve 212 through the check valve 208 on the pipe line 213.
[0030]
The hydraulic motor 45 generates a driving force in the reverse rotation direction when the pipe line 206 becomes high pressure and the pipe line 205 becomes low pressure by the pump action. This driving force acts as a brake against positive rotation due to load and inertia.
[0031]
The safety valve 212 returns the pressure oil in the pipe line 206 that is about to exceed the set pressure to the tank 59. In other words, the safety valve 212 has a function of preventing a brake action on the hydraulic motor 45 and an abnormal high pressure of the pipe line 206 by limiting the pressure of the pipe line 206.
[0032]
Since the switching valve 51 is at the valve position C, no pressure oil is supplied from the switching valve 51 to any of the pressure oil supply / discharge ports MA and MB. Therefore, the hydraulic motor 45 stops without rotating backward.
[0033]
The pressure oil supply / discharge port MA of the hydraulic motor 45 is at a low pressure due to the suction action. Therefore, when the pressure in the pipe line 205 becomes lower than the pressure in the tank 59, the pressure oil in the tank 59 is sucked and supplied to the pressure oil supply / discharge port MA via the suction valve 210 on the suction pipe line 215. For this reason, it is possible to prevent the occurrence of cavitation mainly due to the generation of negative pressure due to insufficient flow.
[0034]
The same applies to the case where the switching valve 51 is positioned at the neutral position C from the state where the hydraulic motor 45 in which the switching valve 51 is at the B position is rotated in the reverse direction. A braking force corresponding to the set pressure of the safety valve 212 acts on the hydraulic motor 45, and the hydraulic motor 45 stops.
[0035]
As described above, in the conventional hydraulically driven fan device shown in FIG. 12, each auxiliary device of the hydraulic motor such as the safety valve 212, the check valves 207 and 208, and the suction valves 209 and 210 is provided on the downstream side of the switching valve 51.
[0036]
Now, in the hydraulic drive fan device, control is performed to increase the rotational speed of the fan when the temperature of the radiator cooling water or pressure oil becomes high, and to decrease the rotational speed of the fan when the temperature becomes low.
[0037]
FIG. 11 is a diagram showing a conventional hydraulically driven fan device that controls the rotational speed.
[0038]
The hydraulic pump 64 is driven by the engine 79 and supplies pressure oil to the hydraulic motor 61 via the pump discharge line 70.
[0039]
The pump discharge line 70 is provided with a throttle 76. A safety valve 78 is connected to the pump discharge line 70. The safety valve 78 discharges to the tank 66 when the pressure oil in the pipe line 70 exceeds the set pressure.
[0040]
A pressure oil supply port 61 a of the hydraulic motor 61 communicates with the pump discharge pipe 70. The hydraulic oil discharge port 61 b of the hydraulic motor 61 communicates with the discharge pipe 69.
[0041]
A fan 68 that cools the radiator 62 is mounted on the hydraulic motor 61.
Accordingly, the fan 68 is rotationally driven in accordance with the rotational driving of the hydraulic motor 61.
[0042]
A suction valve 63 that guides the pressure oil only from the pipe 69 to the pipe 70 is provided. For this reason, when the pipe line 69 becomes higher in pressure than the pipe line 70, the pressure oil in the pipe line 69 is guided to the pipe line 70.
[0043]
The unload valve 65 is a valve that changes the flow rate of the pressure oil supplied to the hydraulic motor 61 by discharging the pressure oil upstream of the throttle 76 passing through the pump discharge pipe 70 to the tank 66.
[0044]
That is, the spring force of the spring 77 acts on one end of the unload valve 65 in a direction to reduce the opening area of the unload valve 65, and the pressure oil supplied from the electromagnetic on / off control valve 80 increases the opening area on the other end. It is acting in the direction to do. Further, a differential pressure generated in the throttle 76 acts on the unload valve 65.
[0045]
When the unload valve 65 is at the position R, the flow rate of the pressure oil discharged to the tank 66 through the unload valve 65 is reduced. On the other hand, at the position S, the flow rate of the pressure oil discharged to the tank 66 increases. When the differential pressure across the throttle 76 increases, the unload valve 65 moves to the position S side and the discharge amount to the tank 66 increases, and when the differential pressure across the throttle 76 decreases, the unload valve 65 moves to the position R side and the tank. The amount discharged to 66 is reduced. Therefore, the differential pressure across the throttle 76 is kept constant. Therefore, the flow rate supplied to the hydraulic motor 61 is made constant and the rotation speed of the fan 68 is made constant.
[0046]
The electromagnetic on / off control valve 80 supplies pressure oil to the other end of the unload valve 65 when an on command signal is applied from the controller 67. As a result, the unload valve 65 moves to the valve position S side, the opening area increases, and the flow rate discharged to the tank 66 increases. Accordingly, the flow rate supplied to the hydraulic motor 61 is reduced and the rotational speed of the fan 68 is reduced.
[0047]
Next, control performed by the hydraulically driven fan device shown in FIG. 11 will be described.
[0048]
When the command signal output from the controller 67 is off, no pressure oil is supplied from the electromagnetic on / off control valve 80 to the other end of the unload valve 65. For this reason, the differential pressure across the throttle 76 is maintained at a constant value. Therefore, the flow rate supplied to the hydraulic motor 61 is held at a constant value, and the rotation speed of the fan 68 is held at a constant value.
[0049]
When an ON command signal is applied from the controller 67 to the electromagnetic on / off control valve 80, pressure oil is supplied to the other end of the unload valve 65. As a result, the unload valve 65 moves to the valve position S side, and the flow rate passing through the throttle 76 is reduced as described above. Therefore, the flow rate supplied to the hydraulic motor 61 is reduced and the rotational speed of the fan 68 is reduced.
[0050]
As described above, in the conventional hydraulically driven fan device, the flow rate supplied to the hydraulic motor is controlled using the unload valve.
[0051]
[Problems to be solved by the invention]
As described above, in the hydraulic circuit assumed in FIG. 9, the rotation direction of the hydraulic motor 45 is switched by using the switching valve 51.
Further, auxiliary equipment for the hydraulic motor 45 such as the counter balance valve 50, safety valves 46 and 47, check valves 48 and 49, and the like is provided on the downstream side of the switching valve 51. That is, a pipe line for connecting an auxiliary machine such as the safety valve 45 is provided between the hydraulic motor 45 and the switching valve 51.
[0052]
This causes a problem that the field of the hydraulic motor becomes large. Furthermore, since the switching valve 51 and the hydraulic motor 45 are separate bodies, a large number of joints that connect the pipes are required, resulting in a complicated structure.
[0053]
Further, in the hydraulically driven fan device shown in FIG. 12, auxiliary equipment for the hydraulic motor 45 such as the safety valve 212 and the check valves 207, 208, 209, and 210 is provided on the downstream side of the switching valve 51. That is, a conduit for connecting auxiliary machines such as the safety valve 212 and the check valves 207, 208, 209, and 210 is provided between the hydraulic motor 45 and the switching valve 51.
[0054]
This causes a problem that the space of the hydraulically driven fan device increases. Furthermore, since the switching valve 51 and the hydraulic motor 45 are separate bodies, a large number of joints that connect the pipes are required, resulting in a complicated structure.
[0055]
This also causes the problem that the space of the hydraulically driven fan device becomes large and the structure becomes complicated.
[0056]
Further, if the switching valve 51 shown in FIG. 10 is provided in the hydraulically driven fan device shown in FIG. 11, the switching valve 51 and the unloading valve 65 must be configured separately. As a result, a problem arises that the space of the hydraulically driven fan device becomes large and the structure becomes complicated.
[0057]
An object of the present invention is to provide a hydraulic motor and a switching valve close to each other, thereby reducing the space of the hydraulic drive device and simplifying the structure.
[0058]
Another object of the present invention is to reduce the space of the hydraulic drive device and to simplify the structure by integrating the switching valve and the unload valve.
[0059]
[Means, functions and effects for solving the problems]
The first invention of the present invention is:
The hydraulic oil (1) that is driven by the pressure oil discharged from the hydraulic pump (2) being supplied via the pump discharge line (7), and the pressure oil is supplied via the pump discharge line (7). A switching valve (12) for switching the supply direction of the pressure oil that is input and supplied to the hydraulic motor (1), and a suction valve (13) that sucks the pressure oil into the pressure oil supply side port of the hydraulic motor (1). In the hydraulic drive device using the provided hydraulic motor,
The suction valve (13) is disposed upstream of the switching valve (12), and pressure oil is guided only in the direction of the pump discharge line (7) by the suction valve (13).
It is characterized by.
[0060]
The first invention will be described with reference to FIG.
[0061]
According to the first aspect of the invention, the suction valve 13 is disposed on the upstream side of the switching valve 12, and the pressure oil is guided only in the direction of the pump discharge pipe 7 by the suction valve 13. Since the suction valve 13 can be arranged upstream of the switching valve 12, other auxiliary machines (safety valve 4) other than the suction valve 13 can be arranged upstream of the switching valve 12 at the same time. Since each auxiliary machine that has been downstream of the conventional switching valve can be arranged upstream of the switching valve 12, the hydraulic motor 1 and the switching valve 12 can be arranged close to each other. As a result, the space of the hydraulic drive device is reduced and the structure of the hydraulic drive device is simplified.
[0062]
The second invention of the present invention is:
In the hydraulic motor that is driven by the supply of the pressure oil discharged from the hydraulic pump (2) and the supply direction of the pressure oil is switched by the switching valve (12),
The switching valve (12) is provided in the body (11) of the hydraulic motor (1).
It is characterized by.
[0063]
The second invention will be described with reference to FIG.
[0064]
According to the second aspect of the invention, the switching valve 12 is built in the body 11 of the hydraulic motor 1. As a result, the space of the hydraulic drive device is reduced and the structure of the hydraulic drive device is simplified.
[0065]
The third invention of the present invention is
Driven by the supply of pressure oil discharged from the hydraulic pump (2), the supply direction of the pressure oil is switched by the switching valve (12), and the pressure oil feeds the suction valve (13) to the pressure oil supply side port. In the hydraulic motor sucked through
The switching valve (12) and the suction valve (13) are provided in the body (11) of the hydraulic motor (1).
It is characterized by.
[0066]
The third invention will be described with reference to FIGS.
[0067]
According to the third aspect of the invention, the suction valve 13 is disposed on the upstream side of the switching valve 12, and the pressure oil is guided only in the direction of the pump discharge pipe 7 by the suction valve 13. Since the suction valve 13 can be arranged upstream of the switching valve 12, other auxiliary machines (safety valve 4) other than the suction valve 13 can be arranged upstream of the switching valve 12 at the same time. Each auxiliary machine that has conventionally been downstream of the switching valve can be arranged upstream of the switching valve 12. For this reason, the hydraulic motor 1 and the switching valve 12 can be provided close to each other, and the switching valve 12 can be built in the body 11 of the hydraulic motor 1. As a result, the space of the hydraulic drive device is reduced and the structure of the hydraulic drive device is simplified.
[0068]
According to a fourth aspect of the present invention, in the third aspect,
The switching valve (12) is constituted by a spool (10), and the spool (10) of the switching valve (12) and the suction valve (13) are provided on substantially the same plane in the body (11). thing
It is characterized by.
[0069]
The fourth invention will be described with reference to FIG.
[0070]
According to the fourth invention, the switching valve 12 is constituted by the spool 10, and the spool 10 of the switching valve 12 and the suction valve 13 are provided on substantially the same plane in the body 11. Thereby, the field area of the body 11 can be further reduced.
[0071]
The fifth invention of the present invention is
A hydraulic motor (1 ′) that is driven by the supply of pressure oil discharged from the hydraulic pump (2), and a switching position for supplying the pressure oil to one port (MA) of the hydraulic motor (1 ′) ( In a hydraulic drive apparatus using a hydraulic motor having A) and a switching valve having a switching position (B) for supplying pressure oil to the other port (MB),
The switching valve (12c) includes a switching position (C ′) for reducing the flow rate of the pressure oil supplied to the one port (MA).
Supplying pilot pressure to both end faces (103, 104) of the switching valve (12c);
Switching the valve position of the switching valve (12c) by reducing the pilot pressure supplied to one end face (104) of the switching valve (12c).
It is characterized by.
[0072]
The fifth invention will be described with reference to FIG.
[0073]
According to the fifth aspect of the present invention, the switching valve 12c includes the switching position C ′ for reducing the flow rate of the pressure oil supplied to one port MA of the hydraulic motor 1 ′. Then, pilot pressure is supplied to both end faces 103 and 104 of the switching valve 12c, and the pilot pressure supplied to one end face 104 of the switching valve 12c is controlled to be reduced, whereby the valve position of the switching valve 12c is switched. Thereby, the function of the switching valve and the unloading valve is realized by one switching valve 12c, and it is not necessary to arrange the switching valve and the unloading valve separately.
[0074]
Therefore, according to the present invention, the space of the hydraulic drive device is reduced, and the structure of the hydraulic drive device is simplified.
[0075]
The sixth invention of the present invention is:
The hydraulic oil (1 ') that is driven by the pressure oil discharged from the hydraulic pump (2) being supplied via the pump discharge line (7a), and the pressure oil via the pump discharge line (7a) The switch position (A) for supplying pressure oil to one port (MA) of the hydraulic motor (1 ') and the switch position (B) for supplying pressure oil to the other port (MB) are provided. In a hydraulic drive apparatus using a hydraulic motor, comprising a switching valve and a suction valve (13) for sucking pressure oil into a pressure oil supply side port of the hydraulic motor (1 ′),
The switching valve (12c) includes a switching position (C ′) for reducing the flow rate of the pressure oil supplied to the one port (MA).
As long as the discharge pressure of the hydraulic pump (2) is not substantially affected, the pump discharge pipe (7a) is branched and the pilot pressure is supplied to both end faces (103, 104) of the switching valve (12c). And
Switching the valve position of the switching valve (12c) by reducing the pilot pressure supplied to one end face (104) of the switching valve (12c).
It is characterized by.
[0076]
The sixth invention will be described with reference to FIG.
[0077]
According to the sixth aspect, the functions of the switching valve and the unloading valve are realized by the single switching valve 12c, and it is not necessary to arrange the switching valve and the unloading valve separately. Further, so as not to affect the discharge pressure of the hydraulic pump 2, the pump discharge pipe 7a is branched and the pilot pressure is supplied to both end faces 103 and 104 of the switching valve 12c. Therefore, the switching valve 12c can be switched without affecting the discharge pressure of the hydraulic pump 2.
[0078]
The seventh invention of the present invention is
Driven by the supply of pressure oil discharged from the hydraulic pump (2), the pressure oil is supplied to the switching position (A) for supplying the pressure oil to one port (MA) and the other port (MB). In a hydraulic motor that is switched between whether pressure oil is supplied to the one port (MA) or pressure oil to the other port (MB) by a switching valve having a switching position (B),
The switching valve (12c) includes a switching position (C ′) for reducing the flow rate of the pressure oil supplied to the one port (MA).
Supplying pilot pressure to both end faces (103, 104) of the switching valve (12c);
The valve position of the switching valve (12c) is switched by reducing the pilot pressure supplied to one end face (104) of the switching valve (12c),
The switching valve (12c) is provided in the body (11 ') of the hydraulic motor (1').
It is characterized by.
[0079]
The seventh invention will be described with reference to FIG.
[0080]
The function of the switching valve and the unloading valve is realized by one switching valve 12c, and it is not necessary to arrange the switching valve and the unloading valve separately. The switching valve 12c is built in the body 11 'of the hydraulic motor 1'. As a result, the space of the hydraulic drive device is reduced and the structure of the hydraulic drive device is simplified.
[0081]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the structure of a hydraulic drive device and a hydraulic motor using the hydraulic motor according to the present invention will be described below.
[0082]
In the present embodiment, a hydraulic drive fan device is assumed as the hydraulic drive device.
[0083]
FIG. 1 is a hydraulic circuit diagram of the first embodiment. The hydraulic motor 1 in FIG. 1 corresponds to the hydraulic motor 45 in FIG. 9 or the hydraulic motor 61 in FIG. The switching valve 12 in FIG. 1 corresponds to the switching valve 51 in FIGS. 9 and 11. 1 corresponds to the safety valves 46 and 47 in FIG. 9, the safety valve 78 in FIG. 10, or the safety valve 212 in FIG. The suction valve 13 in FIG. 1 corresponds to the suction valve 63 in FIG. 10 or the suction valves 209 and 210 in FIG.
[0084]
The hydraulic motor 1 is a hydraulic actuator that rotationally drives the fan 36.
[0085]
The hydraulic pump 2 is driven by the engine 5 to discharge the pressure oil to the pump discharge line 7. The pump discharge line 7 is connected to the upstream port C of the switching valve 12.
[0086]
The switching valve 12 and the pressure oil supply / discharge ports MA and MB of the hydraulic motor 1 are connected by pipe lines 74 and 75, respectively.
[0087]
The switching valve 12 inputs pressure oil through the pump discharge line 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. The switching valve 12 is operated by an operation lever (not shown).
[0088]
When the switching valve 12 is positioned at the valve 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 (this is defined as forward rotation). When the switching valve 12 is located at the valve 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 (this is defined as reverse rotation). When the switching valve 12 is positioned at the valve position C (neutral position), the pressure oil supplied from the hydraulic pump 2 to the hydraulic motor 1 is shut off. Note that the pressure oil discharged from the tank port T of the switching valve 12 is discharged to the tank 3 through the pipe 6.
[0089]
A suction valve 13 and a safety valve 4 are arranged on the upstream side of the switching valve 12.
[0090]
The pipeline 6 and the pump discharge pipeline 7 are communicated by pipelines 8 and 9.
[0091]
The pipe 8 is provided with a suction valve 13 that guides the pressure oil discharged from the tank port T of the switching valve 12 only in the direction from the pipe 6 to the pump discharge pipe 7.
[0092]
The pipe 9 is provided with a safety valve 4 that guides the pressure oil to the tank 3 when the hydraulic pressure of the pump discharge pipe 7 exceeds a set pressure.
[0093]
As described above, according to the first embodiment, since the suction valve 13 can be disposed upstream of the switching valve 12, the suction valve 13 and another auxiliary machine (safety valve 4) can be simultaneously disposed upstream of the switching valve 12. The auxiliary machines such as the suction valve 13 and the safety valve 4 which are downstream of the conventional switching valve are reduced as compared with the prior art shown in FIGS. Moreover, since it can arrange | position to the upstream of the switching valve 12, the hydraulic motor 1 and the switching valve 12 can be arrange | positioned closely. Therefore, the switching valve 12 and the suction valve 13 can be built in the body 11 of the hydraulic motor 1 as indicated by a broken line in FIG. Note that a safety valve 4 may be incorporated in the body 11 of the hydraulic motor 1 as indicated by a one-dot chain line in FIG. Thereby, the space of the hydraulically driven fan device is reduced, and the structure of the hydraulically driven fan device is simplified.
[0094]
Next, operations performed in the first embodiment shown in FIG. 1 will be described.
[0095]
Assume that the switching valve 12 is at the valve position A. The pressure oil discharged from the hydraulic pump 2 is supplied to the port MA of the hydraulic motor 1 through the pump discharge pipe 7, the switching valve 12, and the pipe 74. As a result, the hydraulic motor 1 is rotated forward. For this reason, the fan 36 rotates in the forward direction.
[0096]
Here, an operation lever (not shown) is operated to stop the rotation of the hydraulic motor 1 and the switching valve 12 is set to the valve position C (neutral position).
[0097]
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 pipe line 6 communicating with the port MB is higher than that in the pipe line 7. At this time, the pressure oil in the pipe line 6, which has become a high pressure, is guided to the pump discharge pipe line 7 through the suction valve 13 on the pipe line 8. For this reason, the high pressure oil is sucked into the port MA of the hydraulic motor 1.
[0098]
When the switching valve 12 is positioned at the valve position B, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MB of the hydraulic motor 1 through the pump discharge pipe 7, the switching valve 12, and the pipe 75. As a result, the hydraulic motor 1 is reversely rotated. For this reason, the fan 36 rotates in the reverse direction.
[0099]
When the switching valve 12 is positioned at the neutral position C, the pressure oil discharged from the hydraulic pump 2 is blocked by the switching valve 12 and no pressure oil is supplied to any of the ports MA and MB of the hydraulic motor 1.
[0100]
Although the switching valve 12 provided with the valve position C is used in the first embodiment shown in FIG. 1, a switching valve having only the valve positions A and B may be used.
[0101]
Next, a structural example of the hydraulic motor 1 according to the first embodiment will be described with reference to FIG.
[0102]
FIG. 2 is an external view of the hydraulic motor 1.
[0103]
As shown in FIG. 2, the body 11 of the hydraulic motor 1 includes an end cover 1a and a casing 1b.
[0104]
3 is a cross-sectional view of the hydraulic motor 1 shown in FIG. The same components as those in FIG. 1 described above are denoted by the same reference numerals, and description of these components will be omitted as appropriate.
[0105]
As shown in FIG. 3, the spool 10 of the switching valve 12 and the suction valve 13 are provided on the substantially same plane in the end cover 1a. Thus, since the spool 10 of the switching valve 12 and the suction valve 13 are provided on substantially the same plane of the end cover 1a, the volume of the hydraulic motor 1 can be reduced.
[0106]
A screw 24 is provided at one end of the spool 10. The spool 10 moves according to the screwing amount of the screw 24. That is, a screw 24 is provided instead of the operation lever.
[0107]
The sleeve 26 is fixed to the end cover 1a with screws. The screw 24 is screwed into the sleeve 26. The screw 24 is screwed into the sleeve 26 and then fixed to the sleeve 26 by a lock nut 25.
[0108]
A plug 27 is provided at a position facing the sleeve 26 across the spool 10.
[0109]
In accordance with the movement of the spool 10, the conduit 7 and the port MA or the conduit 7 and the port MB communicate with each other. Accordingly, the discharge pressure oil of the hydraulic pump 2 is supplied to the port MA or the port MB of the hydraulic motor 1 through the pump discharge line 7 and the spool 10.
[0110]
FIG. 4 shows a second embodiment.
[0111]
In the first embodiment shown in FIG. 3, the valve position of the switching valve 12 is switched by the screw 24. However, the valve position of the switching valve 12 may be switched using the electromagnetic proportional control valve 28 as in the second embodiment shown in FIG.
[0112]
The end cover 1c corresponds to the end cover 1a of FIG. The spool 10a corresponds to the spool 10 in FIG.
[0113]
A pipe line 29 communicating with the pump discharge pipe 7 is formed in the end cover 1c.
[0114]
A spring 31 is in contact with one end surface 100 of the spool 10a. The other end of the spring 31 is supported by a plug 32. As a result, the spring force of the spring 31 is applied to the one end 100 of the spool 10a.
[0115]
A support member 33 is provided at a position facing the plug 32 with the spool 10a interposed therebetween. The support member 33 is attached to the end cover 1c. An electromagnetic proportional control valve 28 is attached to the support member 33. Further, the port T communicates with the tank 3 through the pipe 6.
[0116]
A pipe line 29 a communicating with the pipe line 29 is formed in the support member 33. Further, a pipe line 30 communicating with the pipe line 29 a via the electromagnetic proportional control valve 28 is formed in the support member 33. The pipe line 30 communicates with the other end surface 101 of the spool 10a.
[0117]
The electromagnetic proportional control valve 28 is a valve that reduces the hydraulic pressure in the pipe 29 a in accordance with a command signal and guides it to the pipe 30.
[0118]
The operation of the second embodiment will be described below.
[0119]
The pump discharge pressure oil supplied from the pump discharge line 7 to the line 29 a via the line 29 is reduced to a pressure corresponding to the command signal by the electromagnetic proportional control valve 28 and guided to the line 30.
[0120]
The pressure oil guided to the pipe line 30 is supplied to the end surface 101 of the spool 10 a and presses the spool 10 a against the spring 31. As a result, the spool 10a moves in a direction to retract the spring 31 to a position corresponding to the command signal given to the electromagnetic proportional control valve 28.
[0121]
FIG. 5 shows a third embodiment.
[0122]
In the second embodiment shown in FIG. 4, the position of the spool is switched by the electromagnetic proportional control valve 28. However, the position may be switched using the direct acting motor 35 as in the third embodiment shown in FIG.
[0123]
The spool 10b corresponds to the spool 10 in FIG. 3 and the spool 10a in FIG.
[0124]
A support member 81 is provided at a position facing the plug 32 with the spool 10b interposed therebetween. The support member 81 is attached to the end cover 1a. A direct acting motor 35 is attached to the support member 81.
[0125]
In the direct acting motor 35, the rod 34 expands and contracts in response to an input of a command signal.
[0126]
The rod 34 of the direct acting motor 35 is in contact with the end 102 of the spool 10b opposite to the side where the spring 31 is provided.
[0127]
According to the structure of FIG. 5, when a command signal is input to the direct acting motor 35, the rod 34 expands and contracts and the spool 10b moves.
[0128]
In the third embodiment shown in FIG. 5 described above, the suction valve 13 is provided on the surface of the pump discharge pipe 7 where the opening 700 is formed. However, as shown in FIG. 6, the suction valve 13 may be provided on the surface to which the direct acting motor 35 is attached.
[0129]
FIG. 6 shows a fourth embodiment.
[0130]
According to the configuration of FIG. 6, when the work for removing the suction valve 13 is performed, the work efficiency can be improved without removing the housing.
[0131]
Next, a hydraulically driven fan device in which fan speed control is performed will be described with reference to FIG.
[0132]
FIG. 7 is a hydraulic circuit diagram of the fifth embodiment. The same components as those in FIG. 1 described above are denoted by the same reference numerals, and description of these components will be omitted as appropriate. The pipelines 6a and 7a correspond to the pipelines 6 and 7 in FIG. The pipes 74a and 75a correspond to the pipes 74 and 75 in FIG. A body 11 'indicated by a broken line corresponds to the body 11 indicated by a broken line in FIG. The hydraulic motor 1 'corresponds to the hydraulic motor 1 shown in FIG. The switching valve 12c with an unload function corresponds to the switching valve 12 in FIG.
[0133]
As shown in FIG. 7, the hydraulic pump 2 discharges pressure oil to the pump discharge line 7a. The pump discharge pipe 7a is branched into a pressure oil supply path 41a and a pressure oil supply path 41c. The pump discharge line 7a is connected to the upstream port P of the switching valve 12c with an unload function.
[0134]
In other words, the pilot pressure can be supplied to both end faces 103 and 104 of the switching valve 12c by branching the pump discharge pipe 7a so as not to affect the discharge pressure of the hydraulic pump 2. Therefore, the switching valve 12c can be switched without affecting the discharge pressure of the hydraulic pump 2.
[0135]
The pressure oil supply passage 41a supplies pressure oil to one end face 103 of the switching valve 12c with an unload function. The pressure oil supply path 41c is further connected to the pressure oil supply path 41d. The pressure oil supply passage 41d supplies pressure oil to the other end face 104 of the spool 10c of the switching valve 12c with an unload function. A spring 42 is provided on the same side as the other end face 104. Further, a throttle 40 is provided on the pressure oil supply path 41c.
[0136]
The switching valve 12c with an unload function and the pressure oil supply / discharge ports MA and MB of the hydraulic motor 1 'are connected to each other by pipe lines 74a and 75a.
[0137]
The switching valve 12c with an unload function controls the direction of the pressure oil discharged from the hydraulic pump 2 in accordance with the positions A, C ′, B and supplies the pressure oil to the port MA or the port MB of the hydraulic motor 1 ′. It is a switching valve. The switching valve 12c with an unload function has a switching position for reducing the flow rate of the pressure oil supplied to the one port MA, in addition to the switching position A for supplying the pressure oil to the one port MA of the hydraulic motor 1 '. C 'is provided. Then, pilot pressure is supplied to both end faces 103 and 104 of the switching valve 12c, and the pilot pressure supplied to one end face 104 of the switching valve 12c is controlled to be reduced, whereby the valve position of the switching valve 12c is switched. Thereby, the function of the switching valve and the unloading valve is realized by one switching valve 12c. That is, it is not necessary to arrange the switching valve and the unloading valve separately as in the prior art. According to this embodiment, the space of the hydraulically driven fan device is reduced, and the structure of the hydraulically driven fan device is simplified.
[0138]
That is, when the switching valve 12c with the unload function is located at the position A, the pressure oil is supplied to the port MA of the hydraulic motor 1 ', and the hydraulic motor 1' rotates in the forward direction (this is defined as forward rotation). When the spool 10c is located at the 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 (this is defined as reverse rotation). When located at position C ′, pressure oil is supplied to the port MA of the hydraulic motor 1 ′ and the hydraulic motor 1 ′ is rotated in the forward direction as in the position A. However, when located at position C ′, the upstream port P and the tank port T communicate with each other through the throttle 12e inside the switching valve 12c, so that the port MA of the hydraulic motor 1 ′ is compared with the position A. The flow rate of the supplied pressure oil decreases.
Therefore, by displacing from the position C ′ to the position A, the flow rate of the pressure oil supplied to the hydraulic motor 1 can be changed, and the rotation speed of the fan 36 can be controlled.
[0139]
A pipe line 38 is connected to the pressure oil supply path 41d. This pipe line 38 communicates with the downstream side of the throttle 40.
[0140]
The pipe 38 is provided with an electromagnetic proportional control valve 14 for reducing the pressure oil supplied to the end face 104 of the switching valve 12c via the pressure oil supply path 41d. The electromagnetic proportional control valve 14 controls the flow rate according to the command signals X and X ′ output from the controller 37.
[0141]
The controller 37 outputs a command signal X to the electromagnetic proportional control valve 14 so that the pressure oil corresponding to the temperature of the radiator cooling water or the pressure oil is supplied to the hydraulic motor 1 '.
[0142]
The controller 37 outputs a command signal X ′ for switching the rotation direction of the fan 36.
[0143]
Further, the pressure oil discharged from the electromagnetic proportional control valve 14 is discharged to the tank 3 through the pipe line 39 and the pipe line 6a.
[0144]
That is, by controlling the flow rate of the pressure oil by the electromagnetic proportional control valve 14, as a result, the pressure of the pressure oil supply path 41d is controlled.
[0145]
As a result, the valve positions A, C ′ and B of the switching valve 12c are switched.
[0146]
Further, the pressure oil discharged from the tank port T of the switching valve 12c with the unload function is discharged to the tank 3 through the pipe line 39b and the pipe line 6a.
[0147]
A suction valve 13 and a safety valve 4 are arranged upstream of the switching valve 12c with an unload function, as in FIG.
[0148]
That is, the pipe line 6 a and the pump discharge pipe line 7 a are communicated by the pipe lines 8 and 9.
[0149]
The pipe 8 is provided with a suction valve 13 that guides the pressure oil discharged from the tank port T of the switching valve 12c only in the direction from the pipe 6a to the pump discharge pipe 7a.
[0150]
The pipe 9 is provided with a safety valve 4 that guides the pressure oil to the pipe 6a when the hydraulic pressure of the pump discharge pipe 7a exceeds the set pressure.
[0151]
As described above, according to the fifth embodiment, since the suction valve 13 can be arranged upstream of the switching valve 12c with an unload function, the suction valve 13 and another auxiliary machine (safety valve 4) are simultaneously switched with the switching valve 12c with an unload function. Can be placed upstream of The auxiliary machines such as the suction valve 13 and the safety valve 4 which are downstream of the conventional switching valve are reduced as compared with the prior art shown in FIGS. Further, since it can be arranged upstream of the unload switching valve 12c, the hydraulic motor 1 'and the switching valve 12c can be arranged close to each other. Therefore, as shown by the broken line in FIG. 7, the switching valve 12c with an unload function and the suction valve 13 can be built in the body 11 ′ of the hydraulic motor 1 ′. In addition, as shown with the dashed-dotted line of FIG. 7, you may incorporate the safety valve 4 in the body 11 'of hydraulic motor 1'. Thereby, the space of the hydraulically driven fan device is reduced, and the structure of the hydraulically driven fan device is simplified.
[0152]
Next, operations performed in the fifth embodiment shown in FIG. 7 will be described.
[0153]
When the command signal X ′ for switching the rotation direction of the fan 36 to the normal rotation direction is output from the controller 37, the electromagnetic proportional control valve 14 supplies the pressure oil supplied to the end face 104 of the switching valve 12c via the pressure oil supply path 41d. Do not decompress. In this state, the hydraulic pressure applied to both end faces 103 and 104 of the switching valve 12c is substantially equal. Further, a spring force by the spring 42 is applied to the same side as the end face 104. For this reason, it moves to the left in the figure and the switching valve 12c with the unload function is located at the valve position A. The pressure oil discharged from the hydraulic pump 2 is supplied to the port MA of the hydraulic motor 1 'through the pump discharge pipe 7a, the change valve 12c with an unload function, and the pipe 74a. As a result, the hydraulic motor 1 'is rotated forward. For this reason, the fan 36 rotates in the forward direction.
[0154]
When the command signal X for decreasing the rotational speed is output from the controller 37 while keeping the rotational direction of the fan 36 in the positive rotational direction, the electromagnetic proportional control valve 14 is connected to the end face 104 of the switching valve 12c via the pressure oil supply passage 41d. The pressure oil to be supplied is reduced to an intermediate size. Therefore, the switching valve 12c with an unload function is located at the valve position C ′. The pressure oil discharged from the hydraulic pump 2 is input to the upstream port P of the exchange valve 12c with an unload function through the pump discharge line 7a. When the switching valve 12c is located at the position C ', the upstream port P and the tank port T communicate with each other via a throttle 12e inside the switching valve 12c. As a result, the pressure oil is discharged from the tank port T to the tank 3. For this reason, the flow rate of the pressure oil supplied to the port MA of the hydraulic motor 1 ′ is reduced as compared with when the switching valve 12 c is positioned at the position A. For this reason, the rotation speed of the fan 36 falls. In this way, the unload function is realized by the switching valve 12c.
[0155]
When the command signal X ′ for switching the rotation direction of the fan 36 to the reverse rotation direction is output from the controller 37, the electromagnetic proportional control valve 14 is supplied with the pressure oil supplied to the end face 104 of the switching valve 12c through the pressure oil supply path 41d. The pressure is reduced. In this state, the hydraulic pressure applied to the end surface 103 of the switching valve 12 c is larger than the hydraulic pressure applied to the end surface 104. For this reason, the switching valve 12c moves to the B position. At this time, the pressure oil discharged from the hydraulic pump 2 is supplied to the port MB of the hydraulic motor 1 ′ via the pump discharge pipe 7a, the switching valve 12c with an unload function, and the pipe 75a. As a result, the hydraulic motor 1 'rotates in the reverse direction. For this reason, the fan 36 rotates in the reverse direction.
[0156]
FIG. 8 is a view showing a specific structure in the body 11 ′ of the hydraulic motor 1 ′ of FIG. The same components as those in FIG. 7 described above are denoted by the same reference numerals, and description of these components will be omitted as appropriate. The end cover 1e corresponds to the end cover 1c in FIG. The plug 44 corresponds to the plug 32 of FIG. The support member 43 corresponds to the support member 33 in FIG. The electromagnetic proportional control valve 14 corresponds to the electromagnetic proportional control valve 28 of FIG.
[0157]
As shown in FIG. 8, in the end cover 1e, the spool 10c and the suction valve 13 are provided on substantially the same plane. Accordingly, the field area of the hydraulic motor 1 'can be reduced.
[0158]
A spring 42 abuts on the same side as the end face 104 of the spool 10c. The other end of the spring 42 is supported by a support member 43. As a result, the spring force of the spring 42 is applied to the same side as the end face 104 of the spool 10c.
[0159]
The support member 43 is attached to the end cover 1e. An electromagnetic proportional control valve 14 is attached to the support member 43.
[0160]
A plug 44 is provided at a position facing the support member 43 across the spool 10c. The plug 44 is attached to the end cover 1e.
[0161]
A pump discharge line 7a is formed in the end cover 1e.
[0162]
The pipeline 41c corresponds to the diaphragm 40 in FIG. The pipe 41c has no restriction effect statically. The pipe 41c may have any diameter that is substantially unaffected by the flow rate of the pressure oil supplied from the pipe 7a to the port MA. In FIG. 7, the diaphragm 40 is provided for the sake of convenience, but it is not necessary to actively provide an orifice or the like.
[0163]
A pressure oil supply passage 41c is formed in the spool 10c to connect the pump discharge pipe 7a and the end face 104. The throttle diameter of the throttle 40 is determined according to the passage diameter of the pressure oil supply path 41c. The pressure oil supply path 41 c communicates with the pressure oil supply path 41 d at the end face 104. The pressure oil supply path 41 d is formed in the support member 43.
[0164]
In addition, a pressure oil supply passage 41a that connects the pump discharge pipe 7a and the end face 103 is formed in the spool 10c.
[0165]
A pipe line 38 communicating with the pressure oil supply path 41d is formed in the support member 43. A pipe 39 is formed in the support member 43 to communicate with the pipe 38 via the electromagnetic proportional control valve 14.
[0166]
FIG. 8 operates as follows.
[0167]
That is, FIG. 8 shows a state where the pressure oil supplied to the end face 104 of the spool 10c by the electromagnetic proportional control valve 14 is not reduced.
[0168]
In this state, the hydraulic pressure applied to the end face 104 of the spool 10c via the pump discharge pipe 7a and the pressure oil supply paths 41c and 41d and the end face 103 of the spool 10c via the pump discharge pipe 7a and the pressure oil supply path 41a. The applied hydraulic pressure is almost equal. A spring force by the spring 42 is applied to the same side as the end face 104 of the spool 10c. Therefore, the spool 10c is at the position shown in FIG. 8, and the pipe line 7a and the port MA are in communication. The pressure oil discharged from the hydraulic pump 2 outside the end cover 1e is supplied to the port MA through the pump discharge pipe 7a, the pump side port P, and the spool 10c. As a result, the hydraulic motor 1 'is rotated forward. For this reason, the fan 36 rotates in the forward direction.
[0169]
On the other hand, the pressure oil discharged from the port MB of the hydraulic motor 1 'flows into the tank port T via the spool 10c. For this reason, the pressure oil is discharged from the tank port T to the tank 3 outside the end cover 1e through the pipeline 39b and the pipeline 6a.
[0170]
When the command signal X ′ is input to the electromagnetic proportional control valve 14 from this state, the pressure oil discharged from the outlet of the electromagnetic proportional control valve 14 is supplied to the tank 3 on the end cover 1 e side via the pipe line 39 and the pipe line 6 a. Discharged.
[0171]
The pressure oil depressurized by the electromagnetic proportional control valve 14 acts on the end surface 104 of the spool 10c via the pipe line 38 and the pressure oil supply path 41d.
[0172]
Therefore, the spool 10c moves from the position shown in FIG. 8 to the left in the figure. As a result, the conduit 7a communicates with the port MB. The pressure oil discharged from the hydraulic pump 2 outside the end cover 1e is supplied to the port MB via the pump discharge pipe 7a, the pump side port P, and the spool 10c. Accordingly, the hydraulic motor 1 'is rotated in the reverse direction. For this reason, the fan 36 rotates in the reverse direction.
[0173]
In the above-described embodiment, the case where the present invention is applied to a hydraulically driven fan device has been described. However, the present invention can be applied to any target as long as it is a hydraulic drive device that requires switching of the rotation direction of the hydraulic motor.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a first embodiment.
FIG. 2 is an external view of a hydraulic motor according to the present embodiment.
3 is a cross-sectional view taken along the line BB in FIG. 2. FIG.
FIG. 4 is a diagram illustrating a second embodiment.
FIG. 5 is a diagram showing a third embodiment.
FIG. 6 is a diagram illustrating a fourth embodiment.
FIG. 7 is a hydraulic circuit diagram of a fifth embodiment.
FIG. 8 is a diagram showing a configuration inside an end cover of the hydraulic motor of FIG. 7;
FIG. 9 is a diagram showing a prior art.
FIG. 10 is a diagram showing a prior art different from FIG. 9;
FIG. 11 is a diagram showing a conventional technique different from FIG. 9;
[Explanation of symbols]
1, 1 '... Hydraulic motor
2 ... Hydraulic motor
11, 11 '... Body
12 ... Switching valve
12c ... Switching valve with unload function
13 ... Suction valve

Claims (2)

A hydraulic motor (1 ') that is driven by pressure oil discharged from a fixed displacement hydraulic pump (2) being supplied via a pump discharge line (7a), and the pump discharge line (7a) A switching position (A) for supplying pressure oil to one port (MA) of the hydraulic motor (1 ') and a switching position (B) for supplying pressure oil to the other port (MB) A hydraulic drive device using a hydraulic motor comprising a switching valve provided with a suction valve (13) for sucking pressure oil into a pressure oil supply side port of the hydraulic motor (1 ′),
The switching valve (12c) includes a switching position (C ′) for reducing the flow rate of the pressure oil supplied to the one port (MA).
The pump discharge pipe (7a) is branched within a range that does not substantially affect the discharge pressure of the hydraulic pump (2), and pilot pressure is supplied to both end faces (103, 104) of the switching valve (12c). ,
Hydraulic pressure characterized by switching the valve position of the switching valve (12c) by performing pressure-reducing control for discharging the pilot pressure supplied to one end face (104) of the switching valve (12c) to the tank (3). Hydraulic drive device using a motor. A hydraulic motor (1 ') that is driven by pressure oil discharged from a fixed displacement hydraulic pump (2) being supplied through a pump discharge line (7a), and the pump discharge line (7a) A switching position (A) for supplying pressure oil to one port (MA) of the hydraulic motor (1 ') and a switching position (B) for supplying pressure oil to the other port (MB) A switching valve for switching the supply direction of the pressure oil supplied to the hydraulic motor (1 ′), and a suction valve (13) for sucking the pressure oil into the pressure oil supply side port of the hydraulic motor (1 ′). In the hydraulic drive device using the provided hydraulic motor,
The suction valve (13) is arranged on the upstream side of the switching valve (12c), and the suction valve (13) is configured to guide pressure oil only in the direction of the pump discharge line (7a),
The switching valve (12c) includes a switching position (C ′) for reducing the flow rate of the pressure oil supplied to the one port (MA).
The pump discharge pipe (7a) is branched within a range that does not substantially affect the discharge pressure of the hydraulic pump (2), and pilot pressure is supplied to both end faces (103, 104) of the switching valve (12c). ,
Hydraulic pressure characterized by switching the valve position of the switching valve (12c) by performing pressure-reducing control for discharging the pilot pressure supplied to one end face (104) of the switching valve (12c) to the tank (3). Hydraulic drive device using a motor.

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