Hydraulic hoist double-cylinder synchronization device

Abstract

This application relates to a dual-cylinder synchronous device for a hydraulic gate hoist, comprising one oil inlet, two oil outlets, twin cylinders, an electromagnetic directional valve, a check valve, a limit switch, a PLC, and oil pipes. The twin cylinders consist of two parallel, identically structured oil cylinders; each cylinder contains a piston and piston rod; the two piston rods are rigidly connected. The device uses the energization and de-energization of the electromagnetic directional valve to ensure that oil enters the two upper chambers while oil exits the two lower chambers, and vice versa; the rigidly connected piston rods allow the two pistons to move synchronously within the twin cylinders. This device can divide the hydraulic oil from the inlet into two equal portions, which flow out from the two outlets. The beneficial effect of this application is that the oil inlet is connected to the hydraulic gate hoist's oil pump, and the two outlets are respectively connected to the dual cylinders of the hydraulic gate hoist, achieving synchronization of the two cylinders by supplying equal amounts of oil to both cylinders.

Description

Technical Field

[0001] This application relates to the field of gate hoists for water conservancy projects, and in particular to a dual-cylinder synchronous device for a hydraulic gate hoist. Background Technology

[0002] In water conservancy projects, hydraulic gate hoists, compared to fixed winch gate hoists, have a later start but many advantages and are gradually being promoted and used. However, the technical challenge of asynchronous operation of the two cylinders in hydraulic gate hoists has been hindering their further promotion.

[0003] For double-lift gates, the hydraulic hoist has two hydraulic cylinders, one on the left and one on the right. The hydraulic pump of the hoist supplies hydraulic oil to the cylinders, causing them to contract and open the gate. The gate closes by its own weight, and the hydraulic oil automatically flows back to the tank. During the opening process, if the resistance on both sides of the gate is unbalanced, the cylinder with less resistance will receive more oil, causing its piston rod to contract faster. This results in the two cylinders of the hydraulic hoist being out of sync, leading to gate tilting, jamming, and twisting deformation, affecting normal gate opening and closing. If the synchronization problem of the two cylinders in the hydraulic hoist is not resolved, the equipment will pose a serious safety hazard. A schematic diagram of the relationship between the hydraulic hoist and the gate without any correction device is shown below. Figure 1 .

[0004] Currently, there is ongoing research into the synchronous operation of dual-cylinder hydraulic gate hoists in water conservancy projects.

[0005] Method 1: Increase gate rigidity. Use more steel in gate manufacturing to prevent twisting and deformation. Disadvantage 1: Increased gate weight, wasting steel and increasing investment; Disadvantage 2: Increased opening force of the hydraulic hoist. The hydraulic cylinder, oil pump, and motor must also be correspondingly larger, increasing investment.

[0006] Method 2: Symmetrical arrangement of oil pipes. The length and path of the oil pipes flowing to the left and right hydraulic cylinders of the hydraulic hoist are exactly the same, arranged symmetrically to ensure that the pressure loss along the flow of hydraulic oil is the same. Disadvantage 1: Increased oil pipe length, wasting pipe materials and increasing investment; Disadvantage 2: Increased risk of oil leakage in the pipeline.

[0007] Method 3: Install speed control valves. Install speed control valves on the oil pipes flowing to the left and right hydraulic cylinders of the hydraulic gate hoist, respectively, to regulate the amount of oil flowing into the left and right cylinders. Disadvantage 1: The speed control valves can only roughly adjust the hydraulic oil flow, roughly achieving synchronization between the two cylinders of the hydraulic gate hoist. Disadvantage 2: Installing speed control valves cannot solve the problem of uneven resistance between the left and right sides during gate opening, causing asynchrony between the two cylinders. See the diagram showing the relationship between the hydraulic gate hoist and the gate with speed control valves installed. Figure 2 .

[0008] Method 4: Install a normally closed 2-position 2-way solenoid directional valve.

[0009] Normally closed two-position two-way solenoid directional valves are installed on the oil pipes flowing to the left and right hydraulic cylinders of the hydraulic hoist. The solenoid valves close the drain channel when de-energized and open the drain channel when energized. The working principle of the normally closed two-position two-way solenoid directional valve is as follows: The PLC of the hydraulic hoist continuously receives displacement information from the left and right hydraulic cylinders. When the displacement deviation between the left and right hydraulic cylinders exceeds a set value, the PLC issues a command to open the drain channel of one of the two-position two-way solenoid directional valves, draining oil to the oil tank. When the displacement of both cylinders returns to balance, the PLC issues a command to close the drain channel of the solenoid directional valve.

[0010] Disadvantage 1: The required hydraulic cylinder displacement measuring device is high-precision, expensive, and has a short service life. To achieve precise oil discharge from the solenoid directional valve, two sets of hydraulic cylinder displacement measuring devices with millimeter-level accuracy are needed. If only the gate opening needs to be measured, only one ordinary hydraulic cylinder displacement measuring device with centimeter-level accuracy is required.

[0011] Disadvantage 2: Upgrading and modifying ordinary hydraulic gate hoists is difficult and costly. The hydraulic cylinders require major overhaul at the factory, involving significant modifications to the piston rods. This includes removing the chrome plating of the anti-corrosion layer, engraving graduations on the piston rods, and applying ceramic corrosion protection. Converting two hydraulic cylinder piston rods with a pulling force of 1000KN and a stroke of 7m into ceramic piston rods with graduations, plus two sets of displacement sensors, requires an additional investment of over ten thousand yuan.

[0012] Disadvantage 3: Safety hazards exist. If one of the hydraulic cylinder displacement measuring devices malfunctions, the following fault will occur: the displacement information of one hydraulic cylinder is correct, while the displacement information of the other hydraulic cylinder is incorrect. In the actual case where the two cylinders are synchronized, the PLC will misjudge that the two cylinders are not synchronized and issue an incorrect command, causing one of the two-position two-way solenoid directional valves to open the oil drain channel and drain oil into the oil tank, resulting in the gate being unable to open and close normally.

[0013] A schematic diagram showing the relationship between the hydraulic hoist and the gate for installing a normally closed 2-position 2-way solenoid directional valve is shown below. Figure 3 . Utility Model Content

[0014] To overcome the above deficiencies, this application aims to provide a dual-cylinder synchronizing device for a hydraulic gate hoist, which achieves synchronization of the two cylinders by supplying equal amounts of hydraulic oil to both cylinders of the hydraulic gate hoist.

[0015] To achieve the above objectives, this application adopts the following technical solution: A hydraulic gate hoist dual-cylinder synchronous device includes one oil inlet, two oil outlets, twin cylinders, a two-position three-way solenoid directional valve, a check valve, a limit switch, a PLC, and oil pipes.

[0016] Furthermore, the twin cylinders include two cylinders arranged side by side with identical structures, each cylinder containing a piston and a piston rod; the two piston rods are fixedly connected by a rigid connecting member.

[0017] Furthermore, an upper limit limit switch is provided at the top dead center of the twin cylinder piston rod's stroke; a lower limit limit switch is provided at the bottom dead center of the twin cylinder piston rod's stroke.

[0018] Furthermore, the upper limit limit switch and the lower limit limit switch are electrically connected to the PLC.

[0019] Furthermore, the PLC is electrically connected to the two-position three-way solenoid valve.

[0020] Furthermore, the two-position three-way solenoid directional valve is connected to the two upper chambers and two lower chambers of the twin cylinder via oil pipes; the two-position three-way solenoid directional valve is connected to one oil inlet and two oil outlets via oil pipes.

[0021] This application has the following beneficial effects: Advantage 1: This application can divide the hydraulic oil at the inlet into two equal parts, which flow out from two outlets. The inlet is connected to the oil pump of the hydraulic gate hoist, and the two outlets are respectively connected to the two cylinders of the hydraulic gate hoist. By supplying equal amounts of oil to the two cylinders of the hydraulic gate hoist, the synchronization of the two cylinders of the hydraulic gate hoist is achieved.

[0022] Advantage 2: This device has a simple structure, reliable function, and is easy to install, disassemble, and maintain. Ordinary hydraulic gate hoists do not require major overhauls at the factory; they can be easily upgraded and retrofitted on-site at hydraulic structures to achieve synchronous operation of the dual cylinders of the hydraulic gate hoist.

[0023] Advantage 3: This device overcomes the technical challenge of asynchronous operation of the two cylinders in hydraulic gate hoists at a lower cost, has practical market value, and provides a broad prospect for the promotion and application of hydraulic gate hoists in water conservancy projects. Attached Figure Description

[0024] Figure 1 A schematic diagram showing the relationship between a hydraulic hoist and a gate without any correction device installed. Figure 2 A schematic diagram showing the relationship between a hydraulic hoist with a speed control valve installed and the gate. Figure 3 A schematic diagram showing the relationship between a hydraulic hoist and a gate with a normally closed two-position two-way solenoid directional valve installed. Figure 4 A schematic diagram showing the relationship between the hydraulic hoist and the gate as described in this application.

[0025] Legend: 1-Twin cylinder, 2-Piston, 3-Piston rod, 4-Rigid connecting piece, 5-Two-position three-way solenoid directional valve, 6-Oil inlet, 7-Oil outlet, 8-Check valve, 9-Oil pump, 10-Hydraulic cylinder of hydraulic gate hoist, 11-Gate. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] Example like Figure 4 As shown.

[0028] A dual-cylinder synchronous device for a hydraulic gate hoist is installed in the hydraulic gate hoist. The oil inlet 6 of the device is connected to the oil pump 9 of the hydraulic gate hoist via an oil pipe; the two oil outlets 7 of the device are respectively connected to the left and right hydraulic cylinders 10 of the hydraulic gate hoist via oil pipes.

[0029] A dual-cylinder synchronizing device for a hydraulic gate hoist includes one oil inlet 6, two oil outlets 7, twin cylinders 1, a two-position three-way solenoid directional valve 5, a check valve 8, a limit switch, a PLC, and oil pipes. An oil pump 9 is connected to the twin cylinders 1 via the oil inlet 6 and one two-position three-way solenoid directional valve 5. The twin cylinders 1 are connected to the left and right cylinders 10 of the hydraulic gate hoist via the two two-position three-way solenoid directional valves 5 and the oil outlets 7, respectively. The limit switch controls the stroke of the twin cylinder pistons 2, and the PLC controls the operation of the synchronizing device.

[0030] The detailed structure is as follows: The twin cylinder 1 includes two oil cylinders arranged side by side and having the same structure. Each of the two oil cylinders is provided with a piston 2 and a piston rod 3. The two piston rods 3 are fixedly connected by a rigid connecting member 4.

[0031] The upper limit limit switch is set at the upper dead point of the twin cylinder piston rod 3; the lower limit limit switch is set at the lower dead point of the twin cylinder piston rod 3.

[0032] Both the upper and lower limit limit switches are electrically connected to the PLC. The PLC is electrically connected to the two-position three-way solenoid valve 5. The two limit switches collect displacement information of the piston reaching the upper and lower dead centers and feed it back to the PLC. After receiving the information from the limit switches, the PLC issues commands to control the energization and de-energization of the three two-position three-way solenoid valves.

[0033] Two of the aforementioned two-position three-way solenoid directional valves 5 are respectively connected to the two upper chambers and two lower chambers of the twin cylinder via oil pipes; one of the aforementioned two-position three-way solenoid directional valves 5 is respectively connected to one oil inlet 6 and two oil outlets 7 via oil pipes. When the three two-position three-way solenoid directional valves are de-energized, the oil inlet of the upper chamber and the oil outlet of the lower chamber of the twin cylinder are both open; the oil outlet of the upper chamber and the oil inlet of the lower chamber of the twin cylinder are both closed. When the three two-position three-way solenoid directional valves 5 are energized, the oil outlet of the upper chamber and the oil inlet of the lower chamber of the twin cylinder 1 are both open; the oil inlet of the upper chamber and the oil outlet of the lower chamber of the twin cylinder are both closed. Four check valves 8, such as... Figure 4 This setting is to prevent hydraulic oil backflow.

[0034] The PLC of this device receives feedback information from the limit switch and controls the energization and de-energization of the solenoid directional valve, so that when oil enters the two upper chambers of the twin cylinder, oil exits the two lower chambers, and when oil enters the two lower chambers, oil exits the two upper chambers. The two piston rods 3 of this device are fixedly connected by a rigid connector 4, so that the piston 2 moves synchronously in a reciprocating motion within the twin cylinder.

[0035] The beneficial effect of this application is that the hydraulic oil flowing into this device from the hydraulic gate hoist oil pump 9 can be divided into two equal parts, which flow into the left and right hydraulic cylinders 10 of the hydraulic gate hoist respectively, so as to realize the synchronization of the two cylinders of the hydraulic gate hoist, and thus control the synchronous rise of both sides of the gate 11.

[0036] The detailed working principle and process of this application are as follows.

[0037] Operating State 1: All three 2-position 3-way solenoid directional valves are de-energized. The upper chamber inlet and lower chamber outlet of twin cylinder 1 are both open, while the upper chamber outlet and lower chamber inlet of twin cylinder 1 are both closed. Oil pump 9 simultaneously supplies oil to the two upper chambers of twin cylinder 1. The hydraulic oil pushes the two pistons 2 of twin cylinder 1 downward synchronously. Under the pressure of piston 2, the two lower chambers of twin cylinder 1 simultaneously discharge an equal amount of hydraulic oil, which flows into the left and right hydraulic cylinders 10 of the hydraulic hoist, respectively.

[0038] Operating State 2: When the two pistons 2 of twin cylinder 1 descend to their lower dead center, they trigger the lower limit travel switch. Upon receiving this information, the PLC energizes all three 2-position 3-way solenoid valves 5, closing both the upper chamber inlet and lower chamber outlet of twin cylinder 1, and opening both the upper chamber outlet and lower chamber inlet. Simultaneously, oil pump 9 supplies oil to the two lower chambers of twin cylinder 1. The hydraulic oil pushes the two pistons 2 upward synchronously. Under the pressure of the pistons 2, the two upper chambers of the twin cylinder simultaneously discharge equal amounts of hydraulic oil, which flow into the left and right hydraulic cylinders 10 of the hydraulic hoist, respectively.

[0039] Operating State 3: When the two pistons 2 of twin cylinder 1 reach the upper limit stop, the upper limit limit switch is triggered. After receiving the information, the PLC de-energizes all three two-position three-way solenoid valves 5, repeating operating state 1, and so on. Piston 2 moves from the upper limit stop to the lower limit stop, and then moves from the lower limit stop to the upper limit stop, completing one working cycle. The two pistons 2 of twin cylinder 1 move synchronously in a reciprocating manner. When oil enters the two upper chambers of twin cylinder 1, oil is discharged from the two lower chambers; when oil enters the two lower chambers, oil is discharged from the two upper chambers. Twin cylinder 1 continuously discharges an equal amount of hydraulic oil, which flows into the left and right hydraulic cylinders 10 of the hydraulic gate hoist, respectively, realizing the synchronous operation of the two cylinders of the hydraulic gate hoist, thereby controlling the synchronous rise of both sides of the gate 11.

[0040] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dual-cylinder synchronous device for a hydraulic gate hoist, characterized in that: It includes one oil inlet (6), two oil outlets (7), twin cylinders (1), two-position three-way solenoid directional valves (5), check valves (8), limit switches, PLC and oil pipes. The oil pump (9) is connected to the twin cylinders (1) through the oil inlet (6) and one two-position three-way solenoid directional valve (5). The twin cylinders (1) are connected to the two cylinders (10) of the hydraulic hoist through two two-position three-way solenoid directional valves (5) and the oil outlets (7). The limit switches are used to control the stroke of the piston (2) of the twin cylinders (1), and the PLC is used to control the operation of the synchronization device. The twin cylinder (1) includes two cylinders arranged side by side with the same structure. Each cylinder is equipped with a piston (2) and a piston rod (3). The two piston rods (3) are fixedly connected by a rigid connector (4).

2. The hydraulic gate hoist dual-cylinder synchronous device according to claim 1, characterized in that: The upper limit limit switch is set at the upper dead point of the twin cylinder piston rod (3); the lower limit limit switch is set at the lower dead point of the twin cylinder piston rod (3).

3. The hydraulic gate hoist dual-cylinder synchronous device according to claim 2, characterized in that: Both the upper limit limit switch and the lower limit limit switch are electrically connected to the PLC.

4. The hydraulic gate hoist dual-cylinder synchronous device according to claim 3, characterized in that: The PLC is electrically connected to three two-position three-way solenoid directional valves (5).

5. A hydraulic gate hoist dual-cylinder synchronous device according to claim 4, characterized in that: The two-position three-way solenoid directional valve (5) is connected to the upper and lower chambers of the twin cylinder (1) through oil pipes; the two-position three-way solenoid directional valve (5) is connected to one oil inlet (6) and two oil outlets (7) through oil pipes.

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