Water gate opening / closing device and hydraulic drive unit

Abstract

To provide a water gate open / close device which can ensure safety even when a motor for lifting a door body has a failure.SOLUTION: A water gate open / close device 1 is provided with: a hydraulic motor 15 connected to a door body 3 and lifting the door body 3; hydraulic sources 16a and 16b including pumps 33a and 33b and motors 34a and 34b driving the pumps to allow control of a discharge rate and a discharge direction; a first close circuit 17 connecting the hydraulic motor 15 and the pumps 33a and 33b; and fail-safe means 23 for limiting fall of the door body 3 by its own weight when the hydraulic sources 16a and 16b are inoperable and limitation of a rotating shaft 15 of the hydraulic motor 15 is released. Consequently, safety is ensured by limiting rapid fall of the door body 3 by its own weight even when the motors 34a and 34b for lifting the door body have failure.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gate opening / closing device for opening and closing a gate and a hydraulic drive unit.

Background Art

[0002] Normally, to open and close the door body of a gate facility provided in a river, canal, or dam, the door body is raised and lowered by driving an electric motor connected to the door body in the opening and closing directions. Also, in the event of a large-scale disaster, for example, when floods occur due to high tides, local heavy rains, etc., or when tsunamis occur due to earthquakes, etc., it is necessary to quickly close the gate. Here, the gate means not only the gate provided in a river, but also all gates such as a drain gate, a weir, a floodgate, a sluice gate, or the intake or discharge facility of a dam, a water control facility, etc.

[0003] As such a device for quickly closing a gate, a gate opening / closing device that raises and lowers a door body by the rotational drive of a hydraulic motor is known (see, for example, Patent Document 1). Also, while using a hydraulic motor to raise and lower the door body, in a state where the power supply is lost due to a power outage caused by a disaster, etc., a gate opening / closing device with a self-weight lowering function that uses the hydraulic motor as a hydraulic pump to adjust the self-weight lowering speed of the door body (see, for example, Patent Document 2) is known.

[0004] In the hydraulic drive system of the gate according to Patent Document 1, the electric motor for driving the hydraulic motor and the electric motor for driving the auxiliary pump for charging are shared by one electric motor, but in a conventional gate opening / closing device, there are those in which the electric motor for driving the hydraulic motor and the electric motor for driving the auxiliary pump for charging are provided separately.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] In the conventional gate opening / closing device described above, when one of the electric motors for driving the hydraulic motor that raises and lowers the gate body fails, if a command for opening / closing the gate is issued in a state where the failure is not recognized, and the one electric motor is not energized, the mechanical brake that restrains the rotating shaft of the hydraulic motor is released by the hydraulic pressure from the auxiliary pump for charge pressure accompanying the driving of the other electric motor. Therefore, if each electromagnetic switching valve etc. of the hydraulic circuit is in an open state, the rotating shaft of the one electric motor may rotate freely and idle, and there is a risk that the gate body may drop suddenly, and there is room for improvement.

[0007] Also, in the conventional gate opening / closing device described above, when the auxiliary pump for charge pressure fails, hydraulic pressure cannot be applied to the mechanical brake that restrains the rotating shaft of the hydraulic motor, and the opening / closing operation of the gate, that is, the raising / lowering operation of the gate body cannot be performed. As a result, until the repair of the auxiliary pump for charge pressure is completed, the raising / lowering operation of the gate body becomes completely impossible. In short, even when the hydraulic pressure of the hydraulic circuit is normal, if the auxiliary pump for charge pressure, which is an auxiliary function, is not in a normal state, the raising / lowering operation of the gate body becomes impossible, causing inconvenience.

[0008] Furthermore, in the hydraulic drive system of the gate described in Patent Document 1, by connecting the hydraulic source and the hydraulic motor by a closed circuit in a hydraulic drive system placed separately from the hydraulic motor, the number of components in the circuit is reduced, so heat generation due to resistance is suppressed. However, in facilities such as gates installed in dams where the height (lift) at which the gate body rises and falls is high, when continuously opening and closing the gate body, the operating time of the gate opening / closing device becomes long, and the hydraulic oil continuously circulates in the closed circuit, causing the temperature of the hydraulic oil to rise and heat to accumulate. For this reason, in order to cool the inside of the closed circuit, for example, a flushing circuit is provided.

[0009] However, in this case, a large-capacity tank is required to store the hydraulic oil necessary for cooling. Also, since the tank has an open structure and there is a risk of leakage from the open part, a gap is required to provide a margin for the required amount of oil, resulting in an even larger-capacity tank. Furthermore, in order to prevent the hydraulic oil from flowing out and contaminating rivers, dam lakes, etc., oil spill countermeasures such as an oil pan and an oil dike corresponding to the capacity of the open-structured tank are required, increasing the space required for installation.

[0010] Furthermore, in the sluice gate opening / closing device described in Patent Document 2, when the weight causes it to descend, the hydraulic oil is temporarily returned to an open-structured tank for cooling, and in order to prevent chattering (abnormal noise, vibration) of the hydraulic motor, the hydraulic pressure generated by the rotation of the hydraulic motor is used to rotate a boost-pressure hydraulic motor, and due to this rotation, a boost-pressure hydraulic pump connected to the boost-pressure hydraulic motor is driven to supply hydraulic oil with a charge pressure to the input side (low-pressure side) of the hydraulic motor. In this case, since the hydraulic oil is temporarily returned to an open-structured tank, in order to supply hydraulic oil with a charge pressure to the input side (low-pressure side) of the hydraulic motor, if the flow rate is not greater than the hydraulic oil flowing into the tank due to the weight-driven descent of the door body, no pressure will be generated in the circuit, so the boost-pressure hydraulic pump needs to discharge more hydraulic oil than the inflow volume, resulting in a larger capacity.

[0011] Furthermore, in a gate opening / closing device with a self-weight lowering function that uses a hydraulic circuit as a closed circuit, when the gate body, which is a heavy object, is lowered at high speed, usually, a flow control valve is used to restrict the flow rate so that the gate body can be lowered by its own weight at a stable speed. However, the falling energy is converted into heat energy by the throttle of the flow control valve, and as the hydraulic oil continues to circulate within the closed circuit, the temperature of the hydraulic oil rises rapidly. For this reason, it is necessary to once return the hydraulic oil to the tank and circulate it for cooling, or to have cooling equipment such as an oil cooler or a flushing circuit. On the other hand, without providing a flow control valve, by the flow rate of the hydraulic oil flowing through the closed circuit, the hydraulic pump and the servo motor for opening / closing operation are rotated, and the servo motor can be used as a generator to lower the weight by the regenerative resistance (dynamic brake) by the regenerative current. However, since the self-weight lowering speed is high compared to the opening / closing speed of the gate body, the required output becomes large, and a resistor for the regenerative current connected to the servo motor and the servo amplifier with an output greater than the output generated during self-weight lowering is required. As a result, the equipment becomes large and costly.

[0012] Furthermore, due to the aging of existing gate facilities and requests for adding self-weight lowering functions, etc., when replacing the gate opening / closing device, there is also a requirement for downsizing the gate opening / closing device due to installation space limitations.

[0013] The present invention has been made in view of such points, and even when the motor for raising and lowering the gate body or the pump for charge pressure fails, it ensures safety and enables the raising and lowering operation of the gate body. Also, while adopting a closed circuit as the hydraulic circuit, it suppresses the temperature rise of the working fluid and aims to provide a gate opening / closing device and a hydraulic drive unit that enable miniaturization and weight reduction.

Means for Solving the Problems

[0014] As a means for solving the above problems, the invention according to the gate opening / closing device of claim 1 is a gate opening / closing device for opening and closing a gate, which is connected to a gate body for opening and closing the gate, and includes a hydraulic motor for raising and lowering the gate body by hydraulic pressure, a pump, and an electric motor for driving the pump, a hydraulic source capable of controlling the discharge amount and discharge direction, a closed circuit in which the hydraulic motor and the pump communicate with each other and the working fluid circulates,A sealed tank that is communicated so as to straddle the closed circuit, a charge pressure source that supplies the working fluid in the storage tank to the sealed tank and supplies the brake mechanism to release the rotating shaft of the hydraulic motor, when the hydraulic source is inoperable and By supplying the working fluid from the charge pressure source to the brake mechanism, a fail-safe means for restricting the self-weight fall of the door body when the restraint of the rotating shaft of the hydraulic motor is released, the fail-safe means is provided in the closed circuit, and includes an emergency shut-off valve that closes when the flow rate of the hydraulic fluid passing through per unit time exceeds a predetermined flow rate, thereby blocking the flow of the hydraulic fluid in the closed circuit. The water gate opening and closing device is characterized by this.

[0015] In the invention of claim 1, when the hydraulic source is inoperable, for example, when two hydraulic sources are provided, either one or both of the two hydraulic sources are inoperable, and even if the restraint of the rotating shaft of the hydraulic motor is unintentionally released, the fail-safe means can restrict the self-weight fall of the door body. As a result, the safety of the water gate opening and closing device can be ensured. Specifically, the fail-safe means is configured to include an emergency shut-off valve in the closed circuit. And when the hydraulic source is inoperable and the electromagnetic switching valve provided in the closed circuit is energized and in the open state, if the restraint of the rotating shaft of the hydraulic motor is unintentionally released, the door body will tend to fall by its own weight. Then, although the flow of the hydraulic fluid in the closed circuit suddenly speeds up, when the flow rate of the hydraulic fluid passing through per unit exceeds the predetermined flow rate, the emergency shut-off valve closes, so that the flow of the hydraulic fluid in the closed circuit is blocked. As a result, the subsequent rapid fall of the door body can be restricted. Also, by adopting the emergency shut-off valve, the pressure loss in the closed circuit can be minimized.

[0016] Further, in the invention according to the gate opening / closing device of claim 1, in particular, the a sealed tank communicated so as to straddle the closed circuit, and supplying the hydraulic fluid in the storage tank to the sealed tank together with a charge pressure source that supplies the brake mechanism to release the rotating shaft of the hydraulic motor, is provided.

[0017] With this configuration,The following effects are achieved. That is, the hydraulic fluid leaked from a hydraulic motor, a hydraulic source, etc. is stored in a storage tank, and in the sealed tank, hydraulic fluid that has not been preheated is stored. By connecting this sealed tank to the suction side when the door body descends from the hydraulic motor, the charge pressure source sucks in more hydraulic fluid from the storage tank than the amount of hydraulic fluid leaked from the pumps of the hydraulic motor and the hydraulic source, and discharges it into the sealed tank where the hydraulic fluid that has not been preheated is stored. From within this sealed tank, the hydraulic fluid that has not been preheated is supplied to the suction side of the hydraulic motor.

[0018] And it is possible to cool the hydraulic fluid in the closed circuit at a low flow rate and maintain that flow rate. As a result, the discharge volume by the charge pressure source (such as an electric motor and a pump) is suppressed, and the charge pressure source can be miniaturized. Also, by configuring it as a sealed tank, no space is required compared to a tank with an open structure, and it can be configured compactly. Furthermore, by configuring it as a sealed tank, even if leakage occurs from the piping, only a slight amount of leakage that causes the pressure to drop is sufficient, and a large amount of hydraulic fluid in the sealed tank will not leak out. Also, since the amount of hydraulic fluid stored in the storage tank only needs to be a small amount because the closed circuit is cooled by the hydraulic fluid in the sealed tank, the storage tank can be made smaller.

[0019] Since the storage tank is a tank with an open structure, there is a possibility that a considerable amount of the hydraulic fluid in the tank may leak out. However, even in the case of providing an oil retaining dike to prevent the outflow of the hydraulic fluid in the tank, a structure for storing only a small amount of hydraulic fluid is sufficient, and it becomes compact. Moreover, this can suppress the outflow of the hydraulic fluid into rivers and dam lakes and prevent contamination. As a result, the entire gate opening and closing device can be miniaturized. Furthermore, by miniaturizing the entire gate opening and closing device, weight reduction of the entire gate opening and closing device is achieved, and since there is no weight increase due to the expansion of the operation room due to miniaturization, even if the gate opening and closing device is installed in an existing gate facility, seismic reinforcement of the gate facility due to weight increase is not required, and costs can be suppressed.

[0020] Claim 2The invention related to the gate opening and closing device is defined in claim 1 In the invention of 1 , it is characterized by comprising a self-weight lowering circuit communicated with the closed circuit and the sealed tank, and a flow control valve provided in the self-weight lowering circuit. Claim 2 In the invention of 2 , since the flow rate of the hydraulic oil flowing through the self-weight lowering circuit is throttled by the flow control valve, the door body can be stably lowered by its own weight at an appropriate self-weight lowering speed. Further, the hydraulic motor and the sealed tank can be communicated in a closed circuit by the self-weight lowering circuit. As a result, the hydraulic fluid flowing along the self-weight lowering circuit flows into the sealed tank, and the hydraulic fluid stored in the sealed tank and not heated circulates in the closed circuit, so that the replacement of the hydraulic fluid is easy, and the cooling effect of the closed circuit can be obtained by the hydraulic fluid stored in the sealed tank and not heated. Further, when the door body is lowered by its own weight, a pressure (charge pressure) equal to or higher than a certain value can be applied to the suction side of the hydraulic motor by applying an amount of hydraulic fluid greater than the amount of hydraulic fluid leaked from the hydraulic motor by the charge pressure source, thereby preventing the occurrence of cavitation.

[0021] Claim 3 The invention related to the gate opening and closing device is a gate opening and closing device for opening and closing a gate, comprising a hydraulic motor connected to a door body for opening and closing the gate and lifting and lowering the door body by hydraulic pressure, a hydraulic source including a pump and an electric motor for driving the pump and capable of controlling the discharge amount and discharge direction, a closed circuit in which a hydraulic fluid circulates by communicating the hydraulic motor and the pump, a sealed tank that is communicated so as to straddle the closed circuit, a charge pressure source for supplying the hydraulic fluid in the storage tank to the sealed tank and supplying it to the the brake mechanism to release the rotating shaft of the hydraulic motor, and an emergency door body lifting and lowering means for making the door body liftable and lowerable by releasing the restraint of the rotating shaft of the hydraulic motor by the brake mechanism when the charge pressure source becomes inoperative. Claim 3 In the invention of 3 , even when the charge pressure source is inoperative, the restraint of the rotating shaft of the hydraulic motor by the brake mechanism can be released by the emergency door body lifting and lowering means, and the lifting and lowering operation of the door body can be enabled.

[0022] Claim 4 In the invention related to the gate opening and closing device of Claim 3 In the invention of Claim Claim 4 In the invention of Claim

[0023] Claim 5 The invention related to the gate opening and closing device of Claim 3 or 4 In the invention of Claim Claim 5 In the invention of Claim 1 and 2 The same effects as those of the invention of Claim

[0024] Claim 6 In the invention related to the gate opening and closing device of Claim 5In any of the inventions, it is characterized by comprising a braking circuit provided in the closed circuit, which, when the hydraulic pressure in the closed circuit exceeds a predetermined pressure, releases the hydraulic pressure from the high-pressure side to the low-pressure side of the closed circuit. Claim 6 In the invention of claim, with the braking circuit, even when the hydraulic pressure in the closed circuit exceeds a predetermined pressure, instead of simply releasing the hydraulic pressure into the storage tank by the relief valve, the hydraulic pressure can be released from the high-pressure side to the low-pressure side of the closed circuit. In other words, when the hydraulic motor (pump function) that was rotating at high speed during free fall is stopped, the braking circuit can release the abnormal hydraulic pressure on the discharge side from the hydraulic motor to the suction side.

[0025] Claim 7 The invention related to the hydraulic drive unit of claim is a hydraulic drive unit for moving a body to be moved, comprising a hydraulic motor for moving the body to be moved by hydraulic pressure, a speed reducer connected to the hydraulic motor, a pump and an electric motor for driving the pump, a hydraulic source capable of controlling the discharge amount and discharge direction, a closed circuit in which the working fluid circulates by communicating the hydraulic motor and the pump, a sealed tank communicated so as to straddle the closed circuit, and a charge pressure source for supplying the working fluid in the storage tank to the sealed tank and the characterized by comprising a charge pressure source for supplying to the braking mechanism to release the rotating shaft of the hydraulic motor. Claim 7 In the invention of claim, a sufficient cooling effect of the working fluid circulating in the closed circuit can be obtained, and the charge pressure source, storage tank, etc. can be made smaller and lighter, and thus the entire hydraulic drive unit can be made smaller and lighter. Thereby, the entire device equipped with the hydraulic drive unit can be made smaller and lighter.

[0026] Claim 8 The invention related to the hydraulic drive unit of claim is, in the invention of claim 7 characterized in that the hydraulic motor, the speed reducer, the hydraulic source, the closed circuit, the sealed tank, the charge pressure source, and the storage tank are integrated. Claim 8In the invention, it is possible to make the installation space for installing the device equipped with the hydraulic drive unit compact.

Effect of the Invention

[0027] According to the water gate opening and closing device of the present invention, in particular, even when the motor for raising and lowering the door body fails, it is possible to suppress the sudden free fall of the door body due to its own weight and ensure safety. Further, according to the water gate opening and closing device of the present invention, even when the charge pressure source fails, it is possible to perform the raising and lowering operation of the door body. Furthermore, according to the water gate opening and closing device of the present invention, it is possible to suppress the temperature rise of the working fluid and achieve miniaturization and weight reduction. Moreover, according to the hydraulic drive unit of the present invention, it is possible to obtain the cooling effect of the working fluid circulating in the closed circuit, and moreover, it is possible to achieve miniaturization and weight reduction of the entire hydraulic drive unit.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0029] Hereinafter, the water gate opening and closing device 1 according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. The floodgate opening / closing device 1 according to an embodiment of the present invention is for opening and closing a floodgate installed in a river, a canal, a dam, etc. Even when the power supply is lost due to a power outage caused by a disaster or the like, the door body 3 can be lowered by its own weight at a safe appropriate lowering speed. In the following description, as an example, a wire rope type floodgate opening / closing device of the 1-motor·1-drum type will be described, but it can be similarly applied to other types of floodgate opening / closing devices such as the 1-motor·2-drum type or the 2-motor·2-drum type.

[0030] In the floodgate opening / closing device 1 according to the present embodiment, as shown in FIG. 1, a door body 3 is supported between a pair of left and right gateposts (not shown) constituting a floodgate (not shown) so as to be movable up and down. The floodgate opening / closing device 1 according to the present embodiment is provided with a drum 6 for winding and pulling out a wire rope 4 connected to the door body 3. An output shaft 8 of a speed reducer 7 is non-rotatably connected to a rotation shaft 6a (see FIG. 2) of the drum 6 via a torque transmission member 6b (see FIG. 2). A rotation shaft 15a of a hydraulic motor 15 is non-rotatably connected to an input shaft 9 of the speed reducer 7. Then, as the rotation shaft 15a of the hydraulic motor 15 rotates, the speed reducer 7 and the drum 6 rotate, and the door body 3 moves up and down by winding or pulling out the wire rope 4. Note that reference numeral 5 in FIG. 2 is a sheave provided in plurality on the upper part of the door body 3 around which a wire rope 13 is wound.

[0031] The water gate opening / closing device 1 according to this embodiment includes a hydraulic drive unit 10 with reference to FIGS. 1 to 3. The hydraulic drive unit 10 includes a hydraulic motor 15, hydraulic sources 16a and 16b, a first closed circuit 17, a second closed circuit 18 including a self-weight lowering circuit 20, a charge pressure source 19, sealed tanks 21a and 21b, a storage tank 22, fail-safe means 23, and emergency door lifting / lowering means 24. In this embodiment, the hydraulic drive unit 10 is adopted in the water gate opening / closing device 1, and the object to be moved corresponds to the door body 3. With reference to FIG. 1, a brake mechanism 30 is attached to the hydraulic motor 15. The brake mechanism 30 is a mechanical brake. The brake mechanism 30 always restrains the rotating shaft 15a of the hydraulic motor 15 by the biasing force of a spring, and the restraint of the rotating shaft 15a of the hydraulic motor 15 is released against the biasing force of the spring by the hydraulic pressure supplied from the charge pressure source 19.

[0032] With reference to FIG. 1, the hydraulic sources 16a and 16b include pumps 33a and 33b and electric motors 34a and 34b, which are arranged in parallel with the first closed circuit 17 to be described in detail later. The pumps 33a and 33b can discharge hydraulic oil in two directions and are fixed-displacement pumps capable of controlling the discharge amount of hydraulic oil by varying the rotational speed of the electric motors 34a and 34b. The pumps 33a and 33b communicate with the storage tank 22 via drain lines 36a and 36b.

[0033] The electric motors 34a and 34b are AC servo motors capable of forward and reverse rotation and are connected to the pumps 33a and 33b. The electric motors 34a and 34b are operated by a three-phase power supply, are electrically connected to an operation panel (not shown), and are operationally controlled by the operation panel. In this embodiment, as the hydraulic sources 16a and 16b, an AC servo motor as the electric motors 34a and 34b and a fixed-displacement pump as the pumps 33a and 33b, which can control the discharge amount and discharge direction, are adopted. In addition, as the hydraulic sources 16a and 16b, those composed of a three-phase induction motor and an inverter and a fixed-displacement pump, or those composed of a three-phase induction motor and a variable-displacement pump can be adopted.

[0034] The hydraulic motor 15 and the pumps 33a and 33b of the hydraulic sources 16a and 16b are communicated with each other by a first closed circuit 17. Specifically, one port of the hydraulic motor 15 (the left side of the paper surface in FIG. 1) and one port of the pumps 33a and 33b of the hydraulic sources 16a and 16b (the left side of the paper surface in FIG. 1) are communicated with each other through a communication path 38a and connection paths 40a and 41a. The other port of the hydraulic motor 15 (the right side of the paper surface in FIG. 1) and the other port of the pumps 33a and 33b of the hydraulic sources 16a and 16b (the right side of the paper surface in FIG. 1) are communicated with each other through a communication path 38b and connection paths 40b and 41b. The communication path 38a and the connection paths 40a and 41a are communicated with each other. The communication path 38b and the connection paths 40b and 41b are communicated with each other.

[0035] The communication paths 38a and 38b are located on the hydraulic motor 15 side, and the connection paths 40a, 40b, 41a, and 41b are located on the hydraulic sources 16a and 16b side. The first closed circuit 17 is configured such that the communication path 38a and the connection paths 40a and 41a communicate with the communication path 38b and the connection paths 40b and 41b across the hydraulic motor 15 and the pumps 33a and 33b of the hydraulic sources 16a and 16b. In other words, the first closed circuit 17 communicates the hydraulic motor 15 with the pumps 33a and 33b of the hydraulic sources 16a and 16b. And the hydraulic oil is configured to circulate through the first closed circuit 17.

[0036] The first closed circuit 17 is provided with a flushing function circuit 44 arranged to straddle the communication path 38a and the communication path 38b. The flushing function circuit 44 is for returning the surplus hydraulic oil above the charge pressure to the storage tank 22. The flushing function circuit 44 includes a flushing valve 45 and a flushing relief valve 46. The flushing valve 45 is communicated with the communication path 38a and the communication path 38b of the first closed circuit 17. The flushing relief valve 46 is communicated with the flushing valve 45. The flushing relief valve 46 is communicated with the storage tank 22. Note that the flushing function circuit 44 is provided to suppress the cavitation generated in the hydraulic motor 15 when the door body 3 descends by its own weight and to cool the heat generation of the hydraulic oil.

[0037] In the connection paths 40a and 41a of the first closed circuit 17, electromagnetic switching valves 48 and 48 are respectively arranged. Each of the electromagnetic switching valves 48 and 48 is energized and opened under the control of the operation panel. On the other hand, when the energization from the operation panel is canceled, the electromagnetic switching valves 48 and 48 are in a closed state. The charge pressure source 19 supplies hydraulic oil from the storage tank 22 to the first closed circuit 17 and the brake mechanism 30. The charge pressure source 19 includes a charge pump 51 and an electric motor 52. The electric motor 52 is non-rotatably connected to the shaft portion of the charge pump 51. The charge pump 51 is rotationally driven by the rotational drive of the electric motor 52. The storage tank 22 is an open-type or sealed-type tank and is communicated with the charge pump 51 via a suction path 54. A filter 55 is provided in the suction path 54.

[0038] The hydraulic oil leaked from the hydraulic motor 15 returns to the storage tank 22 via a communication path 58. A check valve 63 is provided in the communication path 58. The hydraulic oil from the brake mechanism 30 returns to the storage tank 22 via a communication path 59 (including an electromagnetic switching valve 108 and an electromagnetic switching valve 72). The hydraulic oil leaked from the pumps 33a and 33b of the hydraulic pressure sources 16a and 16b returns to the storage tank 22 via drain lines 36a and 36b.

[0039] On the downstream side of the charge pressure source 19 (the left side of the charge pressure source 19 in FIG. 1), a communication path 60 communicating with the storage tank 22 is communicated. A relief valve 65 is provided in the communication path 60. The charge pump 51 of the charge pressure source 19 is communicated with the brake mechanism 30 via a first discharge path 68. A check valve 73, an electromagnetic switching valve 72, and an electromagnetic switching valve 108 are provided in the first discharge path 68. Further, the charge pump 51 is communicated with a sealed tank 21a described later via a second discharge path 69. A check valve 75 and a flow rate adjustment valve 76 are provided in the second discharge path 69.

[0040] The motor 52 can operate with the control power supply (single-phase power supply) of the operation panel in the normal state. On the other hand, the motor 52 can operate with the uninterruptible power supply device (single-phase power supply), the single-phase power supply of a small portable generator, or the DC power supply of a battery during a power outage. The motor 52 is electrically connected to the operation panel and is controlled by the operation panel. The electromagnetic switching valve 72 can operate with the control power supply (single-phase power supply) of the operation panel in the normal state. The electromagnetic switching valve 72 can operate with the uninterruptible power supply device (single-phase power supply), the single-phase power supply of a small portable generator, or the DC power supply of a battery during a power outage. The electromagnetic switching valve 72 is electrically connected to the operation panel and is controlled by the operation panel.

[0041] The sealed tanks 21a and 21b store a predetermined amount of hydraulic oil to send the hydraulic oil to the suction side (communication path 38b of the first closed circuit 17) of the hydraulic motor 15 when the door body 3 descends by its own weight. The sealed tanks 21a and 21b are hermetically sealed. The sealed tanks 21a and 21b communicate with each other. The sealed tanks 21a and 21b communicate with the first closed circuit 17. Specifically, the sealed tank 21a communicates with the discharge side (communication path 38a of the first closed circuit 17) when the door body 3 descends by its own weight via the self-weight descent circuit 20. The sealed tank 21b communicates with the suction side (communication path 38b of the first closed circuit 17) when the door body 3 descends by its own weight via the communication path 78. And with this configuration, when the door body 3 descends by its own weight, the sealed tanks 21a and 21b, and the hydraulic motor 15 are communicated through the second closed circuit 18 including the self-weight descent circuit 20 and the communication path 78.

[0042] The self-weight lowering circuit 20 is provided with a self-weight lowering path 83. The self-weight lowering path 83 communicates the sealed tank 21a with the communication path 38a of the first closed circuit 17. The self-weight lowering path 83 is provided with a flow rate adjustment valve (flow control valve) 85, a partition valve 86, a relief valve 87, an electromagnetic switching valve 88, and a check valve 89. The flow rate adjustment valve 85 can appropriately change the lowering speed of the door body 3 by controlling its opening degree when the door body 3 is lowered by its own weight. Note that the self-weight lowering path 83 is provided with a flow rate adjustment valve 90 and a shut-off valve 91 in parallel with the flow rate adjustment valve 85. When used in the 2-motor·2-drum type, by turning on and off the shut-off valve 91 and the action of the flow rate adjustment valves 85 and 90 to change the discharge amount of the hydraulic oil to the hydraulic motor 15, the lowering speed difference between both ends in the width direction of the door body 3 can be controlled during self-weight lowering. The electromagnetic switching valve 88 can be actuated by an uninterruptible power supply device (single-phase power supply), the single-phase power supply of a small portable generator, or the DC power supply of a battery during a power failure. The electromagnetic switching valve 88 is electrically connected to the operation panel and is controlled by the operation panel.

[0043] A partition valve 92 and a check valve 93 are provided in the communication path 78. Due to the check valve 93, the circuit configuration is such that the hydraulic pressure from the first closed circuit 17 does not act on the sealed tank 21b. The sealed tank 21b is communicated with the storage tank 22 via the discharge path 80. A relief valve 81 is provided in the discharge path 80. Note that in each of the sealed tanks 21a and 21b, during the self-weight lowering of the door body 3, until the door body 3 is completely lowered by its own weight, the working oil required for cooling is stored by circulating through the second closed circuit 18 that communicates the hydraulic motor 15 with the sealed tanks 21a and 21b. Also, since a relief valve 81 is provided in the discharge path 80 and constitutes the second closed circuit 18, air does not flow into the second closed circuit 18 unless the sealed tanks 21a and 21b and the pipes communicating therewith are damaged. Therefore, even if a leak occurs between the pipes, it will be a slight leak that causes the hydraulic pressure to drop.

[0044] In addition, the first closed circuit 17 is provided with fail-safe means 23 and emergency door body lifting / lowering means 24. The fail-safe means 23 restricts the self-weight fall of the door body 3 when the hydraulic pressure sources 16a and 16b are inoperable and the rotation shaft 15a of the hydraulic motor 15 is released from restraint by the hydraulic pressure from the charge pressure source 19. The fail-safe means 23 is composed of an emergency shut-off valve 95a provided in the connection path 40a of the first closed circuit 17 to one of the hydraulic pressure sources 16a and an emergency shut-off valve 95b provided in the connection path 41a of the first closed circuit 17 to the other hydraulic pressure source 16b. The emergency shut-off valve 95a may be provided in the connection path 40b of the first closed circuit 17 to one of the hydraulic pressure sources 16a, and the emergency shut-off valve 95b may be provided in the connection path 41b of the first closed circuit 17 to the other hydraulic pressure source 16b. Each of the emergency shut-off valves 95a and 95b closes when the flow rate per unit time passing through it exceeds a predetermined flow rate, shutting off the flow of the hydraulic oil in the first closed circuit 17.

[0045] On the other hand, the emergency door body lifting / lowering means 24 enables the door body 3 to be lifted and lowered by releasing the restraint of the rotation shaft 15a of the hydraulic motor 15 by the brake mechanism 30 when the charge pressure source 19 becomes inoperable. The emergency door body lifting / lowering means 24 includes check valves 100a and 100b for returning the hydraulic oil in the storage tank 22 to the first closed circuit 17, and a brake release circuit 101 for supplying the hydraulic oil in the first closed circuit 17 to the brake mechanism 30 by the operation of an operator when the charge pressure source 19 becomes inoperable. The connection paths 40a and 40b extending from the suction port and the discharge port of the pump 33a constituting one of the hydraulic pressure sources 16a and the storage tank 22 are communicated with each other by the respective suction paths 103a and 103a.

[0046] Check valves 100a, 100a that allow the flow of hydraulic oil from the storage tank 22 to the first closed circuit 17 are respectively arranged in the respective suction paths 103a, 103a. Further, each connection path 41a, 41b extending from the suction port and the discharge port of the pump 33b constituting the other hydraulic source 16b communicates with the storage tank 22 through the respective suction paths 103b, 103b. Check valves 100b, 100b that allow the flow of hydraulic oil from the storage tank 22 to the first closed circuit 17 are respectively arranged in the respective suction paths 103b, 103b.

[0047] The brake release circuit 101 includes a bypass path 106 that communicates across the communication path 38a and the communication path 38b of the first closed circuit 17, a shuttle valve 107 provided in the bypass path 106, and an electromagnetic switching valve 108 that can communicate with the shuttle valve 107. The shuttle valve 107 has one inlet that communicates with the communication path 38a through the bypass path 106, the other inlet that communicates with the communication path 38b through the bypass path 106, and an outlet that can communicate with both inlets, and the outlet is configured to be automatically connected to the inlet on the higher hydraulic pressure side of the pair of inlets. The electromagnetic switching valve 108 normally communicates the first discharge path 68 and the brake mechanism 30 when the charge pressure source 19 is operable. On the other hand, when the charge pressure source 19 is inoperable, it is energized and opened under the control of the operation panel, and is configured to communicate the shuttle valve 107 (the first closed circuit 17) and the brake mechanism 30.

[0048] Furthermore, the first closed circuit 17 is provided with a braking circuit 110 that releases the hydraulic pressure of the first closed circuit 17 from the high-pressure side to the low-pressure side when the hydraulic pressure of the first closed circuit 17 exceeds a predetermined pressure. The braking circuit 110 is located on the side of the hydraulic motor 15 further away from the electromagnetic switching valves 48, 48. The braking circuit 110 includes a pair of main bypass paths 111a, 111b that communicate across the communication path 38a and the communication path 38b of the first closed circuit 17, a sub-bypass path 112 that communicates between the pair of main bypass paths 111a, 111b, a pair of check valves 113, 113 provided in one of the main bypass paths 111a that allow the flow of hydraulic oil from the communication path 38a and the communication path 38b to the sub-bypass path 112, a brake valve 115 provided in the sub-bypass path 112, and a pair of check valves 114, 114 provided in the other main bypass path 111b that allow the flow of hydraulic oil from the sub-bypass path 112 to the communication path 38a and the communication path 38b.

[0049] The brake valve 115 is configured to open when the hydraulic pressure of the first closed circuit 17 exceeds a predetermined pressure, and release the hydraulic oil in the sub-bypass path 112 from one main bypass path 111a side to the other main bypass path 111b side. Specifically, even when the hydraulic pressure of the first closed circuit 17 exceeds a predetermined pressure, the hydraulic oil does not return to the storage tank 22, and the braking circuit 110 applies the hydraulic pressure from the high-pressure side to the low-pressure side of the first closed circuit 17.

[0050] Referring to FIGS. 2 and 3, the hydraulic motor 15 is arranged adjacent to the speed reducer 7. The two sealed tanks 21a, 21b are arranged adjacent to each other above the speed reducer 7. Above each of the sealed tanks 21a, 21b, the respective hydraulic pressure sources 16a, 16b are arranged adjacent to each other. Above the longitudinal ends of each of the sealed tanks 21a, 21b, a charge pressure source 19 is arranged so as to span the two sealed tanks 21a, 21b. A storage tank 22 is arranged adjacent to the charge pressure source 19. Thus, the hydraulic motor 15, the speed reducer 7, the hydraulic pressure sources 16a, 16b, the charge pressure source 19, the sealed tanks 21a, 21b, and the storage tank 22 are configured as a hydraulic drive unit 7 integrated with the first closed circuit 17 and the second closed circuit 18.

[0051] Next, a method for raising and lowering the door body 3 in a normal state where the power supply has not been lost will be described based on FIG. 1 using the water gate opening / closing device 1 according to the present embodiment. First, in a normal state where the power supply has not been lost, when the door body 3 is not to be raised and lowered, the rotating shaft 15a of the hydraulic motor 15 is restrained by the brake mechanism 30, and the door body 3 cannot be raised and lowered. When raising and lowering the door body 3, an operator operates the operation panel to rotationally drive the electric motor 52 of the charge pressure source 19. Then, due to the rotational drive of the electric motor 52, the charge pump 51 is rotationally driven to suck hydraulic oil from the storage tank 22. Thereafter, the hydraulic oil passes through the second discharge path 69, passes through the sealed tanks 21a and 21b, and is supplied to the communication path 38b of the first closed circuit 17, and a charge pressure is supplied to the first closed circuit 17.

[0052] Next, by energizing the electric motors 34a (34b) of the hydraulic pressure sources 16a (16b) under the control of the operation panel, a servo lock state is achieved. Subsequently, under the control of the operation panel, each electromagnetic switching valve 48, 48 of the first closed circuit 17 is controlled to be in an open state, and the rotational speed of the electric motors 34a (34b) gradually increases. Subsequently, under the control of the operation panel, the electromagnetic switching valve 72 provided in the first discharge path 68 is controlled to be in an open state, and the hydraulic pressure from the charge pressure source 19 (the electric motor 52 and the charge pump 51) is applied to the brake mechanism 30 via the first discharge path 68. As a result, the restraint on the rotating shaft 15a of the hydraulic motor 15 is released, and the rotating shaft 15a of the hydraulic motor 15 becomes rotatable.

[0053] When the door body 3 is raised, the pumps 33a (33b) are rotationally driven by the rotational drive of the electric motors 34a (34b) of the hydraulic pressure sources 16a (16b), and the hydraulic oil in the first closed circuit 17 is in the rising direction of the door body 3 (see the arrow in FIG. 1), that is, from one side (the left side of the paper surface in FIG. 1) of the pumps 33a (33b) to one port (the left side of the paper surface in FIG. 1) of the hydraulic motor 15 via the connection path 40a (41a) and the communication path 38a. Then, the rotation (rotation in the rising direction) of the hydraulic motor 15 is transmitted to the speed reducer 7 and the drum 6, and the door body 3 rises.

[0054] On the other hand, when the door body 3 descends, the hydraulic oil of the first closed circuit 17 is supplied to the other port (the right side of the paper surface in FIG. 1) of the hydraulic motor 15 from the other side (the right side of the paper surface in FIG. 1) of the pumps 33a (33b) of the hydraulic pressure sources 16a (16b) through the connection path 40b (41b) and the communication path 38b in the descending direction of the door body 3 (refer to the arrow in FIG. 1). Then, the rotation (rotation in the descending direction) of the hydraulic motor 15 is transmitted to the speed reducer 7 and the drum 6, and the door body 3 descends. Here, when the hydraulic oil flows into the hydraulic motor 15, the hydraulic oil leaking from the hydraulic motor 15 returns to the storage tank 22 of the charge pressure source 19 through the communication path 58. Also, the hydraulic oil leaking from the pumps 33a, 33b of the hydraulic pressure sources 16a, 16b returns to the storage tank 22 through the drain lines 36a, 36b. As a result, the flow rate of the hydraulic oil circulating in the first closed circuit 17 decreases.

[0055] However, the reduced amount of this hydraulic oil is replenished to the first closed circuit 17 through the storage tank 22 → the second discharge path 69 → the sealed tank 21a → the sealed tank 21b → the communication path 78 because the charge pump 51 of the charge pressure source 19 is driven. Thereby, the reduced amount of the hydraulic oil by the hydraulic motor 15 can be compensated. At this time, since the hydraulic oil whose temperature has not risen is replenished to the first closed circuit 17 from the sealed tanks 21a, 21b, it can contribute to the cooling of the hydraulic oil circulating in the first closed circuit 17. Note that during normal times when the power supply has not been lost, since the electromagnetic switching valve 88 of the self-weight descent circuit 20 (self-weight descent path 83) is in the closed state, the hydraulic oil does not flow into the self-weight descent circuit 20.

[0056] Note that when the door body 3 ascends or descends, when the hydraulic pressure of the first closed circuit 17 exceeds a predetermined pressure by the brake circuit 110, the hydraulic pressure is applied from the high-pressure side to the low-pressure side of the first closed circuit 17. That is, when the hydraulic pressure of the first closed circuit 17 exceeds a predetermined pressure, the hydraulic pressure of the first closed circuit 17 is applied to the low-pressure side of the first closed circuit 17 through the one main bypass path 111a to the brake valve 115 of the sub-bypass path 112 and the other main bypass path 11b.

[0057] Next, based on FIG. 1, a method of causing the door body 3 in the upper limit position to drop by its own weight in a state where the power supply is lost (during a power outage) using the water gate opening / closing device 1 according to the present embodiment will be described. When the power supply is lost due to a power outage caused by a disaster or the like, the hydraulic pressure sources 16a and 16b cannot be rotationally driven. However, since the rotating shaft 15a of the hydraulic motor 15 is restrained by the brake mechanism 30, the door body 3 in the upper limit position does not start to drop by its own weight unintentionally. When the three-phase power supply is lost due to a power outage during a disaster or the like, the operation panel, the electromagnetic switching valve 72 of the first discharge path 68, the electromagnetic switching valve 88 of the self-weight drop circuit 20, and the motor 52 of the charge pressure source 19 can be operated by using a single-phase power supply such as an uninterruptible power supply device or a small portable generator. Here, when causing the door body 3 to drop by its own weight, the hydraulic motor 15 functions as a hydraulic pump as a hydraulic braking device that appropriately adjusts the self-weight drop speed of the door body 3.

[0058] Then, the operator operates the operation panel to cause the door body 3 to drop by its own weight. Then, the electromagnetic switching valves 48, 48 of the first closed circuit 17 are maintained in the closed state. Further, under the control of the operation panel, the electromagnetic switching valve 88 of the self-weight drop circuit 20 (self-weight drop path 83) is controlled to be in the open state. Further, the electromagnetic switching valve 72 provided in the first discharge path 68 is controlled to be in the open state by the operation panel. Furthermore, the electromagnetic switching valve 108 of the brake release circuit 101 maintains a state in which the flow of the hydraulic oil in a predetermined direction is allowed. As a result, a second closed circuit 18 is formed by a part of the communication paths 38a, 38b of the first closed circuit 17, the self-weight drop path 83 of the self-weight drop circuit 20, the sealed tanks 21a, 21b, and the communication path 78.

[0059] Subsequently, by controlling the operation panel, the motor 52 of the charge pressure source 19 is rotationally driven, and by this rotational drive, the charge pump 51 connected to the motor 52 is rotationally driven. By the rotational drive of this charge pump 51, the hydraulic oil is supplied to the communication path 38b of the first closed circuit 17 via the storage tank 22 → the second discharge path 69 → the sealed tank 21a → the sealed tank 21b → the communication path 78, and a charge pressure is supplied to the first closed circuit 17. Also, since the electromagnetic switching valve 72 provided in the first discharge path 68 and the electromagnetic switching valve 108 of the brake release circuit 101 are in the open state (the open state in which the hydraulic oil flows in a predetermined direction), by the rotational drive of the charge pump 51, the hydraulic oil is supplied to the brake mechanism 30 via the storage tank 22 and the first discharge path 68. Thereby, the restraint of the brake mechanism 30 on the rotating shaft 15a of the hydraulic motor 15 is released, and the self-weight descent of the door body 3 is started.

[0060] Subsequently, as the door body 3 descends under its own weight, the rotating shaft 15a of the hydraulic motor 15 that functions as a hydraulic pump rotates via the drum 6 and the speed reducer 7. As the rotating shaft 15a of the hydraulic motor 15 rotates, the hydraulic oil is sucked into the hydraulic motor 15 from the communication path 38b of the first closed circuit 17 and discharged from the hydraulic motor 15 to the communication path 38a. Then, the hydraulic oil discharged to the communication path 38a flows into the self-weight descent path 83 of the self-weight descent circuit 20. At this time, the first closed circuit 17 becomes negative pressure, and the hydraulic oil is applied to the communication path 38b of the first closed circuit 17 via the storage tank 22 → the first discharge path 69 → the sealed tank 21a → the sealed tank 21b → the communication path 78 by the charge pressure source 19 (charge pump 51) at a hydraulic pressure (charge pressure) of a certain level or more and is replenished to the first closed circuit 17. Also, when the door body 3 descends under its own weight, by applying an amount of hydraulic oil more than the amount of the hydraulic oil leaked from the hydraulic motor 15 etc. by the charge pressure source 19, a pressure (charge pressure) of a certain level or more can be applied to the suction side of the hydraulic motor 15 (the communication path 38b of the first closed circuit 17), and the occurrence of cavitation can be prevented.

[0061] Subsequently, the hydraulic oil that has flowed from the communication path 38a of the first closed circuit 17 to the self-weight lowering path 83 will circulate along the second closed circuit 18 as the door body 3 descends under its own weight. That is, the hydraulic oil that has flowed into the self-weight lowering path 83 flows into the sealed tank 21a via the flow rate adjustment valve 85 and the electromagnetic switching valve 88. At this time, since the flow rate of the hydraulic oil flowing into the self-weight lowering path 83 is restricted by the flow rate adjustment valve 85, the rotation of the rotating shaft 15a of the hydraulic motor 15 is appropriately restricted to a certain rotational speed. As a result, the door body 3 can be stably lowered under its own weight at an appropriate self-weight lowering speed. When the hydraulic pressure of the self-weight lowering path 83 exceeds a preset hydraulic pressure, the relief valve 87 of the self-weight lowering circuit 20 can release the hydraulic oil in the self-weight lowering path 83 into the sealed tank 21a.

[0062] Subsequently, the hydraulic oil that has flowed into the sealed tank 21a causes the hydraulic oil that has been pre-stored in the sealed tank 21a and has not had its temperature increased to flow into the sealed tank 21b. Then, the hydraulic oil that has flowed into the sealed tank 21b causes the hydraulic oil that has been pre-stored in the sealed tank 21b and has not had its temperature increased to flow into the communication path 38b of the first closed circuit 17 via the communication path 78. In this way, when the door body 3 descends under its own weight, the hydraulic oil circulates through the second closed circuit 18 (including a part of the first closed circuit 17), and the hydraulic oil in a part of the first closed circuit 17 and the second closed circuit 18 can be cooled by the hydraulic oil in the sealed tanks 21a and 21b that has not had its temperature increased, and the door body 3 can be lowered under its own weight until the end. Also, when the hydraulic motor 15 (pump function) that was rotating at high speed is stopped during the self-weight lowering of the door body 3, the brake circuit 110 can release the abnormal hydraulic pressure on the discharge side (communication path 38a of the first closed circuit 17) from the hydraulic motor 15 to the suction side (communication path 38b of the first closed circuit 17).

[0063] Next, based on the basic operation of the sluice gate opening and closing device 1 according to the above-described embodiment, first, the operation of the sluice gate opening and closing device 1 when either one of the hydraulic pressure sources 16a and 16b becomes inoperative will be described. The operator, due to a failure in a controller or the like of the electric motor 34a or 34b, the controller does not show an error and the failure is not recognized. The operator operates the operation panel and, for example, performs an operation to lower the door body 3 in the upper limit position with respect to the operation panel. Then, by the control of the operation panel, each electromagnetic switching valve 48, 48 of the first closed circuit 17 is controlled to be in an open state. Also, by the control of the operation panel, the electromagnetic switching valve 72 provided in the first discharge path 68 is controlled to be in an open state.

[0064] Furthermore, by the control of the operation panel, the charge pressure source 19 (the electric motor 52 and the charge pump 51) is driven. Then, the hydraulic pressure from the charge pressure source 19 is applied to the brake mechanism 30 via the first discharge path 68. As a result, the restraint on the rotary shaft 15a of the hydraulic motor 15 is released, and the rotary shaft 15a of the hydraulic motor 15 becomes rotatable. At this time, the electric motor 34a or 34b of the hydraulic pressure source 16a or 16b is in a state where the servo lock is released because the controller or the like has failed, and the rotary shaft of the electric motor 34a or 34b is in a free state.

[0065] Next, in the first closed circuit 17, although hydraulic pressure is being applied by the charge pressure source 19, since the rotating shaft 15a of the hydraulic motor 15 is rotatable, the door body 3 begins to fall by its own weight at a speed exceeding a predetermined speed. And at the moment when it begins to fall by its own weight, the flow of the hydraulic oil in the first closed circuit 17 suddenly speeds up, and the rotating shafts of the rotating shaft 15a of the hydraulic motor 15, the electric motors 34a or 34b, and the pumps 33a or 33b rotate idly. However, since either one or both of the emergency shut-off valves 95a, 95b of the fail-safe means 23 provided in the first closed circuit 17 become closed when the flow rate of the hydraulic oil passing through per unit time exceeds a predetermined flow rate, the flow of the hydraulic oil in the first closed circuit 17 is blocked by the action of either one or both of the emergency shut-off valves 95a, 95b. As a result, the door body 3 stops and does not fall further by its own weight. After that, the operator checks for failures in the controllers of the electric motors 34a, 34b, etc., switches to a predetermined manual operation, and drives either one of the other hydraulic pressure sources 16a or 16b that is not faulty to raise and lower the door body 3. In this embodiment, as described above, the operation of the sluice gate opening and closing device 1 when either one of the hydraulic pressure sources 16a, 16b becomes inoperable has been described, but the same operation also occurs when both of the hydraulic pressure sources 16a, 16b become inoperable.

[0066] Next, the operation of the sluice gate opening and closing device 1 when the charge pressure source 19 (such as the charge pump 51 and the electric motor 52, etc.) becomes inoperable will be described. Normally, hydraulic oil leaks from the hydraulic motor 15 and the hydraulic pumps 33a, 33b of the hydraulic pressure sources 16a, 16b to the storage tank 22, and when the charge pressure source 19 becomes inoperable, the first closed circuit 17 becomes negative pressure. Therefore, the check valves 100a, 100b of the emergency door body lifting and lowering means 24 replenish (suck in) the hydraulic oil from the storage tank 22 to the first closed circuit 17.

[0067] Subsequently, when the operator operates the control panel, the electromagnetic switching valve 108 of the emergency door body lifting means 24 is switched so that the hydraulic oil flows in a predetermined direction. That is, in FIG. 1, the electromagnetic switching valve 108 moves to the left side. Then, the hydraulic oil in the first closed circuit 17 is applied to the brake mechanism 30 via the shuttle valve 107 and the electromagnetic switching valve 108. As a result, the restraint of the hydraulic motor 15 on the rotating shaft 15a by the brake mechanism 30 is released. And by releasing the restraint of the brake mechanism 30 on the rotating shaft 15a of the hydraulic motor 15, the door body 3 can be lifted and lowered. Thereafter, depending on the circumstances at that time, the operator can lift and lower the door body 3 by manual operation or the like. At this time, the charge pressure for preventing cavitation of the hydraulic motor 15, which was necessary when the door body 3 descended by its own weight, is not necessarily required because the rotational speed of the hydraulic motor 15 is low during the lifting and lowering operation.

[0068] When the door body 3 is at the upper limit position, when the door body 3 becomes capable of descending, although the first closed circuit 17 is in a state where the hydraulic oil is replenished from the storage tank 22 by the check valves 100a and 100b and slightly holds the hydraulic pressure, the door body 3 may start to fall by its own weight at a speed exceeding a predetermined speed because the restraint of the brake mechanism 30 on the rotating shaft 15a of the hydraulic motor 15 is released. Therefore, the operator needs to control the descending operation of the door body 3 using a manual handle or other braking means. Also, when the charge pressure source 19 (such as the charge pump 51 and the electric motor 52) becomes inoperable, it becomes impossible to operate the self-weight descent of the door body 3 in a state where the power supply is lost (during a power outage) as described above.

[0069] The sluice opening and closing device 1 according to the present embodiment described above includes a fail-safe means 23 for restricting the self-weight fall of the door body 3 when the hydraulic pressure sources 16a and 16b are inoperable and the restraint of the rotating shaft 15a of the hydraulic motor 15 is released. The fail-safe means 23 is provided in the first closed circuit 17 and includes emergency shut-off valves 95a and 95b that close when the flow rate per unit time passing through exceeds a predetermined flow rate and cut off the flow of the hydraulic oil in the first closed circuit 17.

[0070] As a result, when the hydraulic pressure sources 16a and 16b are inoperable and the restraint of the rotating shaft 15a of the hydraulic motor 15 by the brake mechanism 30 is released by the hydraulic pressure from the charge pressure source 19, the door body 3 begins to fall by its own weight. Then, due to the free fall of the door body 3 by its own weight, the flow rate of the hydraulic oil in the first closed circuit 17 suddenly increases. When the flow rate of the hydraulic oil per unit passing through exceeds a predetermined flow rate, either one or both of the emergency shut-off valves 95a and 95b close, so that the flow of the hydraulic oil in the first closed circuit 17 is blocked. As a result, it is possible to regulate the subsequent rapid fall of the door body 3. Further, by adopting the emergency shut-off valves 95a and 95b, the pressure loss in the first closed circuit 17 can be minimized.

[0071] In addition, the sluice gate opening and closing device 1 according to the present embodiment includes an emergency door body lifting / lowering means 24 that enables the door body 3 to be lifted and lowered when the charge pressure source 19 becomes inoperable. The emergency door body lifting / lowering means 24 is provided in the first closed circuit 17 and includes check valves 100a and 100b that return the hydraulic oil in the storage tank 22 to the first closed circuit 17, and an electromagnetic switching valve 108 that opens by the operation of an operator when the charge pressure source 19 becomes inoperable and supplies the hydraulic oil in the first closed circuit 17 to the brake mechanism 30.

[0072] As a result, hydraulic oil is constantly leaking from the hydraulic motor 15 and the pumps 33a and 33b of the hydraulic pressure sources 16a and 16b into the storage tank 22. When the charge pressure source 19 becomes inoperable and the first closed circuit 17 becomes negative pressure, the check valves 100a and 100b can replenish (suction) the hydraulic oil from the storage tank 22 to the closed circuit. Further, when the operator operates the operation panel, the electromagnetic switching valve 108 is switched so that the hydraulic oil flows in a predetermined direction. By switching the electromagnetic switching valve 108, the hydraulic pressure of the first closed circuit 17 is applied to the brake mechanism 30, so that the restraint on the rotating shaft 15a of the hydraulic motor 15 can be released. Even when the charge pressure source 19 fails and becomes inoperable, the operator can temporarily raise and lower the door body 3.

[0073] Furthermore, the floodgate opening / closing device 1 according to the present embodiment is provided with a brake circuit 110 that is arranged so as to straddle the first closed circuit 17 and releases the hydraulic pressure of the first closed circuit 17 from the high-pressure side to the low-pressure side when the hydraulic pressure of the first closed circuit 17 exceeds a predetermined pressure. By means of the brake circuit 110, even when the hydraulic pressure of the first closed circuit 17 exceeds the predetermined pressure, it can be released from the high-pressure side to the low-pressure side of the first closed circuit 17. And, as described above, when the hydraulic motor (pump function) 15 that was rotating at high speed during self-weight lowering is stopped, the brake circuit 110 can release the abnormal hydraulic pressure on the discharge side (communication path 38a of the first closed circuit 17) from the hydraulic motor 15 to the suction side (communication path 38b of the first closed circuit 17).

[0074] Furthermore, the floodgate opening / closing device 1 according to the present embodiment includes sealed tanks 21a and 21b that are communicated so as to straddle the first closed circuit 17, and a charge pressure source 19 that supplies the hydraulic oil in the storage tank 22 to the sealed tanks 21a and 21b. Thereby, the charge pressure source 19 sucks in from the storage tank 22 an amount of hydraulic oil that is not less than the amount of hydraulic oil leaked from the hydraulic motor 15 and the pumps 33a and 33b of the hydraulic pressure sources 16a and 16b, discharges it to the sealed tanks 21a and 21b, and supplies the hydraulic oil that has not been heated in temperature from the sealed tank 21b to the communication path 38b (suction side of the hydraulic motor 15) of the first closed circuit 17. As a result, it is possible to cool the hydraulic oil in the first closed circuit 17 with a small flow rate and maintain that flow rate. Thereby, the discharge amount by the charge pressure source 19 (the electric motor 52, the charge pump 51, etc.) can be suppressed, and the charge pressure source 19 can be miniaturized.

[0075] In addition, since the closed tanks 21a and 21b are provided, it is possible to configure the system compactly without the need for a gap compared to an open-structured tank, and the storage amount of the hydraulic oil can be maximized. Further, since the closed tanks 21a and 21b are provided, even if a leak occurs from the piping, only a slight leak that causes the pressure to decrease is sufficient, and much of the hydraulic oil in the closed tanks 21a and 21b will not leak out. Also, the storage amount of the hydraulic oil in the storage tank 22 can be small because only a small amount of hydraulic oil is required since the first closed circuit 17 is cooled by the hydraulic oil in the closed tanks 21a and 21b. As a result, the hydraulic drive unit 10 can be made smaller and lighter, and thus the entire gate opening / closing device 1 can be made smaller and lighter.

[0076] Furthermore, in the gate opening / closing device 1 according to the present embodiment, a self-weight lowering circuit 20 communicating with the first closed circuit 17 and the closed tanks 21a and 21b, and a flow control valve 85 provided in the self-weight lowering circuit 20 are provided. Thereby, since the flow rate of the hydraulic oil flowing through the self-weight lowering circuit 20 is throttled and restricted by the flow control valve 85, the door body 3 can be stably self-weight lowered at an appropriate self-weight lowering speed.

[0077] Also, when the door body 3 is self-weight lowered, the hydraulic oil flowing along the self-weight lowering circuit 20 flows into the closed tanks 21a and 21b, so that the hydraulic oil stored in the closed tanks 21a and 21b and not having its temperature increased flows into and circulates through a second closed circuit 18 including a part of the first closed circuit 17. As a result, the cooling effect of the second closed circuit 18 including a part of the first closed circuit 17 can be obtained by the hydraulic oil stored in the closed tanks 21a and 21b and not having its temperature increased. Also, when the door body 3 is self-weight lowered, by applying an amount of hydraulic oil greater than the amount of the hydraulic oil leaked from the hydraulic motor 15 or the like by the charge pressure source 19, a pressure (charge pressure) equal to or higher than a certain level can be applied to the suction side of the hydraulic motor 15 (the communication path 38b of the first closed circuit 17), and the occurrence of cavitation can be prevented.

[0078] Furthermore, the floodgate opening / closing device 1 according to the present embodiment includes a hydraulic drive unit 10, which is integrally configured by integrating a hydraulic motor 15, a speed reducer 7, hydraulic sources 16a and 16b, first and second closed circuits 17 and 18, sealed tanks 21a and 21b, a charge pressure source 19, and a storage tank 22. Thereby, a sufficient cooling effect of the hydraulic oil circulating through the first and second closed circuits 17 and 18 can be obtained, the charge pressure source 19, the storage tank 22, etc. can be miniaturized, and thus the entire hydraulic drive unit 10 can be miniaturized. As a result, the entire floodgate opening / closing device 1 equipped with the hydraulic drive unit can be miniaturized, and its installation space can be made compact.

[0079] In the floodgate opening / closing device 1 according to the above-described present embodiment, a wire rope type is adopted, but other lifting means such as a chain type or a rack type may be adopted.

[0080] Also, in the floodgate opening / closing device 1 according to the above-described present embodiment, hydraulic pressure is used, but other hydraulic pressures may be used. Further, in the present embodiment, the above-described hydraulic drive unit 10 is mounted on the floodgate opening / closing device 1, but it may be mounted on other devices.

Description of Reference Numerals

[0081] 1 floodgate opening / closing device, 3 door body (movable body), 10 hydraulic drive unit (hydraulic drive unit), 15 hydraulic motor (hydraulic motor), 16a, 16b hydraulic source (hydraulic source), 17 first closed circuit (closed circuit), 18 second closed circuit, 19 charge pressure source, 20 self-weight lowering circuit, 21a, 21b sealed tank, 22 storage tank, 23 fail-safe means, 24 emergency door body lifting means, 30 brake mechanism, 33a, 33b pump, 34a, 34b motor, 85 flow control valve, 95a, 95b emergency shut-off valve, 100a, 100b check valve, 108 electromagnetic switching valve, 110 brake circuit

Claims

1. A gate opening and closing device for opening and closing a gate, comprising: a hydraulic motor connected to a door body for opening and closing the gate, and configured to raise and lower the door body by hydraulic pressure; a hydraulic source including a pump and an electric motor for driving the pump, and capable of controlling the discharge amount and discharge direction; a closed circuit in which hydraulic fluid circulates by communicating the hydraulic motor and the pump; a sealed tank communicated across the closed circuit; a charge pressure source for supplying the hydraulic fluid in the storage tank to the sealed tank and supplying it to a brake mechanism to release the rotation shaft of the hydraulic motor; a fail-safe means for restricting the self-weight fall of the door body when the hydraulic source becomes inoperable and the supply of the hydraulic fluid from the charge pressure source to the brake mechanism releases the restraint of the rotation shaft of the hydraulic motor; the fail-safe means is provided in the closed circuit; An emergency shut-off valve that closes when the flow rate of the hydraulic fluid passing through per unit time exceeds a predetermined flow rate, and shuts off the flow of the hydraulic fluid in the closed circuit. The gate opening and closing device is characterized by comprising the emergency shut-off valve.

2. A self-weight lowering circuit communicated with the closed circuit and the sealed tank; a flow control valve provided in the self-weight lowering circuit; The gate opening and closing device according to claim 1, further comprising the flow control valve.

3. A gate opening and closing device for opening and closing a gate, comprising: a hydraulic motor connected to a door body for opening and closing the gate, and configured to raise and lower the door body by hydraulic pressure; a hydraulic source including a pump and an electric motor for driving the pump, and capable of controlling the discharge amount and discharge direction; a closed circuit in which hydraulic fluid circulates by communicating the hydraulic motor and the pump; a sealed tank communicated across the closed circuit; a charge pressure source for supplying the hydraulic fluid in the storage tank to the sealed tank and supplying it to a brake mechanism to release the rotation shaft of the hydraulic motor; an emergency door body lifting and lowering means for making the door body liftable and lowerable by releasing the restraint of the rotation shaft of the hydraulic motor by the brake mechanism when the charge pressure source becomes inoperable; The gate opening and closing device is characterized by comprising the emergency door body lifting and lowering means.

4. The emergency door body lifting and lowering means is provided in the closed circuit; a check valve for returning the hydraulic fluid in the storage tank to the closed circuit; an electromagnetic switching valve that opens by an operator's operation when the charge pressure source becomes inoperable, and supplies the hydraulic fluid in the closed circuit to the brake mechanism; The gate opening and closing device according to claim 3, further comprising the electromagnetic switching valve and the check valve.

5. A self-weight lowering circuit communicated with the closed circuit and the sealed tank; A flow control valve provided in the circuit for self-weight lowering, and The gate opening / closing device according to claim 3 or 4, characterized by comprising the same.

6. The gate opening / closing device according to any one of claims 1 to 5, further comprising a braking circuit provided in the closed circuit and configured to release the hydraulic pressure of the closed circuit from the high-pressure side to the low-pressure side when the hydraulic pressure of the closed circuit exceeds a predetermined pressure.

7. A hydraulic drive unit for moving a body to be moved, comprising: A hydraulic motor for moving the body to be moved by hydraulic pressure; A speed reducer connected to the hydraulic motor; A hydraulic pressure source including a pump and an electric motor for driving the pump, and capable of controlling the discharge amount and the discharge direction; A closed circuit in which the hydraulic motor and the pump communicate with each other and the working fluid circulates; A sealed tank communicated so as to straddle the closed circuit; A charge pressure source for supplying the working fluid in the storage tank to the sealed tank and supplying it to a braking mechanism to release the rotating shaft of the hydraulic motor; A hydraulic drive unit characterized by comprising the same.

8. The hydraulic drive unit according to claim 7, characterized in that the hydraulic motor, the speed reducer, the hydraulic pressure source, the closed circuit, the sealed tank, the charge pressure source, and the storage tank are integrated.

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