Underwater trencher system

Abstract

The invention belongs to the technical field of hydraulic pressure, and discloses an underwater trencher system which comprises a jetting cutter, a reversing valve, a valve, a working oil cylinder and an energy accumulator, the valve and the reversing valve are connected with an oil tank, the driving end of the working oil cylinder is connected with the jetting cutter, the reversing valve comprises an oil inlet, a working end and an oil return opening, the oil return opening is connected with the oil inlet and the oil tank, and the energy accumulator is connected with the working end of the working oil cylinder. The working oil cylinder is connected with the working end, the energy accumulator is connected with the working oil cylinder, and a first one-way valve is arranged on an oil way of the energy accumulator and the working oil cylinder; when the valve is powered on, the two ends of the working end are communicated with or disconnected from the working end and the oil return opening respectively, and the spraying knife ascends or descends or maintains the height. And when the valve is powered off, the energy accumulator is communicated with the lower cavity of the working oil cylinder, and the jetting knife is reset. By means of the design, automatic reset of the jetting knife can be achieved under the condition of power failure or faults of the device, and the device has the advantages that system reliability is improved, the service life of the device is prolonged, and operation safety is enhanced.

Description

Technical Field

[0001] The invention relates to the field of hydraulic technology, and in particular to an underwater trenching machine system. Background Art

[0002] With the increasing demand for submarine resource development and submarine communication cable laying, underwater trenching robots, as a highly efficient operating equipment, have been widely used in submarine cable laying, pipeline trenching and maintenance projects. Such equipment usually uses a hydraulic system to drive trenching knives to cut and dig the seabed soil, and provides power through hydraulic pumps to achieve the actions of raising, lowering and maintaining the working position of the trenching knives. However, in the existing technology, the reliability and service life of underwater trenching robots in certain extreme situations still face many challenges.

[0003] When existing underwater trenching equipment is performing underwater operations, if the equipment suddenly loses power or fails, the trenching cutter will often remain in its original working position (for example, embedded in the seabed mud bed, etc.). This situation causes additional load and potential damage to the trenching cutter and other key components, causing the trenching cutter to wear more, deform, or even be damaged, thereby shortening its service life. This problem not only increases the maintenance cost of the equipment, but also affects the overall operating efficiency, posing a greater safety hazard to deep-sea engineering operations.

[0004] Therefore, an underwater trencher system is proposed to solve the above problems. Summary of the invention

[0005] The main purpose of the present invention is to provide an underwater trenching machine system, aiming to solve the problem that when the existing underwater operating equipment suddenly loses power or fails, the trenching knife will remain in the original working position, shortening the service life of the equipment.

[0006] In order to achieve the above-mentioned invention object, the present invention proposes an underwater trenching machine system, including a jet cutter, a reversing valve, a valve, a working oil cylinder and an accumulator, the valve and the reversing valve are connected to an oil tank, the driving end of the working oil cylinder is connected to the jet cutter, the reversing valve includes an oil inlet, a working end and an oil return port, the oil return port is respectively connected to the oil inlet and the oil tank, the working oil cylinder is connected to the working end, the accumulator is connected to the working oil cylinder, and a first one-way valve is provided on the oil path of the accumulator and the working oil cylinder;

[0007] Among them, when the valve is energized, the two ends of the working end are connected / disconnected with the oil inlet and the oil return port respectively, and the jet cutter is lifted / lowered / maintained in height; when the valve is de-energized, the accumulator is connected with the lower chamber of the working oil cylinder, and the jet cutter is reset.

[0008] Furthermore, the reversing valve is connected to the accumulator via an energy storage circuit. When the valve is energized, the energy storage circuit is connected and the accumulator stores pressurized oil.

[0009] Furthermore, a flow regulating valve is provided between the first one-way valve and the working oil cylinder for adjusting and controlling the speed of lifting / lowering / resetting the jet punch.

[0010] Furthermore, the working end includes a first oil port and a second oil port, the oil inlet is connected to the first oil port, the oil return port is connected to the second oil port, the other end of the first oil port is connected to the lower chamber of the working cylinder, the upper chamber of the working cylinder is connected to the oil return port through the second oil port, and the working cylinder drives the jet punch to lift.

[0011] Furthermore, the oil inlet is connected to the second oil port, the oil return port is connected to the first oil port, the other end of the second oil port is connected to the upper chamber of the working cylinder, the lower chamber of the working cylinder is connected to the oil return port through the first oil port, and the working cylinder drives the jet punch to descend.

[0012] Furthermore, the first oil port is connected to the second oil port, the other end of the first oil port is connected to the lower chamber of the working cylinder, and the other end of the second oil port is connected to the upper chamber of the working cylinder, and the working cylinder drives the jet punch to maintain the working height.

[0013] Furthermore, a second one-way valve is provided between the accumulator and the reversing valve.

[0014] Furthermore, the accumulator is provided with a maintenance pressure relief valve for maintenance of the accumulator.

[0015] Beneficial effects:

[0016] An underwater trenching machine system of the present invention includes a jet cutter, a reversing valve, a valve, a working oil cylinder and an accumulator. The valve and the reversing valve are connected to an oil tank. The driving end of the working oil cylinder is connected to the jet cutter. The reversing valve includes an oil inlet, a working end and an oil return port. The oil return port is respectively connected to the oil inlet and the oil tank. The working oil cylinder is connected to the working end. The accumulator is connected to the working oil cylinder. A first one-way valve is provided on the oil circuit between the accumulator and the working oil cylinder. When the valve is powered on, the two ends of the working end are respectively connected / disconnected with the working end and the oil return port, and the jet cutter is lifted / lowered / maintained in height. When the valve is powered off, the accumulator is connected to the lower chamber of the working oil cylinder, and the jet cutter is reset. Through the above design, the equipment can realize automatic resetting of the jet cutter in the event of power failure or malfunction, which has the advantages of improving system reliability, extending equipment service life, and enhancing operation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a working principle diagram of an underwater trenching machine system according to an embodiment of the present invention;

[0018] Figure 2 This is a working principle diagram of power-off recovery of an underwater trenching machine system according to an embodiment of the present invention;

[0019] Figure 3 This is a working principle diagram of the jetting blade lifting of the underwater trenching machine system according to one embodiment of the present invention;

[0020] Figure 4 1 is a schematic diagram of an underwater trenching machine according to an embodiment of the present invention;

[0021] in:

[0022] 100, reversing valve; 110, oil tank; 120, hydraulic pump;

[0023] 200, valve;

[0024] 400, working cylinder; 410, jet punch;

[0025] 500, accumulator; 510, first one-way valve; 520, second one-way valve; 530, flow regulating valve; 540, maintenance pressure relief valve; 550, energy storage circuit;

[0026] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] Reference Figure 1 The present invention discloses an underwater trenching machine system, including a jet cutter 410, characterized in that it includes a reversing valve 100, a valve 200, a working oil cylinder 400 and an accumulator 500, wherein the valve 200 and the reversing valve 100 are connected with an oil tank 110, the driving end of the working oil cylinder 400 is connected with the jet cutter 410, the reversing valve 100 includes an oil inlet, a working end and an oil return port, the oil return port is respectively connected with the oil inlet and the oil tank 110, the working oil cylinder 400 is connected with the working end, the accumulator 500 is connected with the working oil cylinder 400, and a first one-way valve 510 is provided on the oil path of the accumulator 500 and the working oil cylinder 400;

[0032] Among them, when the valve 200 is energized, the two ends of the working end are connected / disconnected with the oil inlet and the oil return port respectively, and the jet cutter 410 is lifted / lowered / maintains height; when the valve 200 is de-energized, the accumulator 500 is connected with the lower chamber of the working oil cylinder 400, and the jet cutter 410 is reset.

[0033] The design concept of the underwater trenching machine system aims to achieve various state switching of the jet cutter 410 through precise control of the hydraulic system, including lifting, lowering, maintaining height and automatic resetting when power is off, so as to improve the reliability and operational flexibility of the system. The entire system realizes the motion control and energy management of the jet cutter 410 through the coordinated design of the reversing valve 100, the valve 200, the working cylinder 400, the accumulator 500 and the first one-way valve 510, so as to meet the needs of complex underwater working environment.

[0034] As shown in the figure, P is the oil inlet, T is the oil return port, A is the first oil port, B is the second oil port, the oil circuit between the first oil port and the lower chamber of the working cylinder 400 is the first oil circuit, the oil circuit between the second oil port and the upper chamber of the working cylinder 400 is the second oil circuit, the connecting oil circuit between the accumulator 500 and the reversing valve 100 is the energy storage circuit 550; the oil circuit between the accumulator 500 and the lower chamber of the working cylinder 400 is the reset circuit; its working principle is as follows: the core of the system is the reversing valve 100, its oil inlet is connected to the pressure oil provided by the hydraulic pump 120, the oil return port is connected to the oil tank 110 for low-pressure oil flow back, the working end is connected to the working cylinder 400, so as to transmit the hydraulic power to the jet cutter 410, the valve 200 switches the channel of the reversing valve 100 through electromagnetic control, and when powered on, the oil inlet and the working end are connected, the pressure oil enters the specific cavity of the working cylinder 400, and pushes the working cylinder 400. The piston moves upward or downward to drive the jet cutter 410 to rise or fall, and at the same time, the oil in the other chamber flows back to the oil tank 110 through the oil return port. When the height of the jet cutter 410 needs to be maintained, the valve 200 switches to the neutral locking state to block the flow of hydraulic oil to the circuit. The pressure in the chamber of the working cylinder 400 remains unchanged through the flow of hydraulic oil in the circuit, thereby stabilizing the jet cutter 410 in the specified position. In the power-off state, the valve 200 and the reversing valve 100 switch to the power-off reset position. At this time, the accumulator 500 is connected to the lower chamber of the working cylinder 400, and the hydraulic oil can only flow from the accumulator 500 to the lower chamber of the working cylinder 400 through the first one-way valve 510, preventing the hydraulic oil from flowing back, releasing the accumulated hydraulic oil to push the jet cutter 410 to automatically reset, and completing the reset protection in an emergency. In this embodiment, the valve is a normally open valve when power is off and normally closed valve when power is on.

[0035] The beneficial effects of this embodiment are reflected in the following aspects: First, through the combined design of the reversing valve 100 and the solenoid valve, flexible control of the action of the jet cutter 410 is achieved, including operating states such as lifting, lowering, and maintaining height, to meet the operating requirements under different working conditions; secondly, the configuration of the accumulator 500 not only improves the energy utilization efficiency of the system, but also provides a reliable reset function in the event of power failure or accidents, ensuring that the jet cutter 410 will not be stuck or damaged due to power failure, greatly improving the safety and stability of the system; the reasonable arrangement of the first one-way valve 510 of the circuit between the accumulator 500 and the working cylinder 400 further ensures the one-way flow of the hydraulic oil, avoiding the interference of pressure fluctuations and backflow phenomena on the operation of the system. In addition, the system is driven by hydraulics, has a high power density and operating accuracy, and is particularly suitable for working requirements in complex underwater environments; the hydraulic system can realize automatic reset of the jet cutter 410 in the event of power failure or emergency through the combined design of the accumulator 500 and the one-way valve. This design not only ensures that the equipment will not get stuck or damaged in the event of a power outage or sudden failure, but also avoids complex manual intervention by operators under dangerous conditions, greatly improving the safety of operations. In addition, the closed nature of the hydraulic system allows it to remain stable in deepwater high-pressure environments and will not be significantly affected by external pressure fluctuations.

[0036] On the basis of the above embodiment, the reversing valve 100 is connected to the accumulator 500 through the energy storage circuit 550. When the valve 200 is energized, the energy storage circuit 550 is connected, and the accumulator 500 stores pressure oil.

[0037] When the valve 200 is energized, the energy storage circuit 550 is in a connected state. The hydraulic oil can not only flow to the working end through the oil inlet to drive the working cylinder 400 to perform the operation, but also flow into the accumulator 500 through the energy storage circuit 550 to store the pressure oil. This design ensures that during the normal operation of the system, the accumulator 500 can continuously store a certain amount of pressure oil to provide the system with backup power for subsequent actions or emergency situations.

[0038] When the equipment is powered off, since the valve 200 is in the disconnected state, the reversing valve 100 switches to the default closed position, and the hydraulic oil in the oil tank 110 cannot flow into the circuit through the normal circuit. At this time, the system cannot directly obtain power from the hydraulic pump 120. At this time, the accumulator 500 stores the pressure oil in the powered state. When the power is off, the accumulator 500 releases the stored pressure oil through the connecting circuit with the working cylinder 400, providing hydraulic power for the lower chamber of the working cylinder 400, pushing the piston upward to return to the initial position, and driving the jet cutter 410 to automatically reset, thereby ensuring that the equipment can safely return to the initial state in the event of a sudden power outage or emergency, and avoiding the jet cutter 410 from staying in the working position and causing mechanical damage or affecting the next operation; in this embodiment, the initial position of the piston of the working cylinder 400 is the top of the cylinder barrel.

[0039] Based on the above embodiment, a flow control valve 530 is provided between the first one-way valve 510 and the working cylinder 400 to adjust the speed of the jet punch 410 to lift / lower / reset.

[0040] This embodiment controls the movement speed of the jet cutter 410 through the flow control valve 530, which can effectively solve the speed control problem of the jet cutter 410 under different working conditions, ensure that its speed is moderate during the lifting, lowering and resetting process, and avoid equipment damage or low efficiency caused by too fast lifting, lowering or resetting speed; the flow control valve 530 can be in various forms, such as a needle valve, a throttle valve or a proportional flow valve. Specifically, the needle valve controls the flow by adjusting the position of the valve core, the throttle valve adjusts the flow by changing the cross-sectional area of ​​the flow channel, and the proportional flow valve can accurately adjust the flow according to the input control signal. In addition, in this embodiment, the flow control valve 530 is arranged on the circuit between the first one-way valve 510 and the working cylinder 400, that is, it is arranged on the side close to the working cylinder 400. Such a design can respond to the action requirements of the jet cutter 410 more quickly and accurately.

[0041] Specifically, the working end includes a first oil port and a second oil port, the oil inlet is connected to the first oil port, the oil return port is connected to the second oil port, the other end of the first oil port is connected to the lower chamber of the working cylinder 400, and the upper chamber of the working cylinder 400 is connected to the oil return port through the second oil port, and the working cylinder 400 drives the jet punch 410 to lift.

[0042] When the reversing valve 100 is switched to the right position, high-pressure oil enters from the oil inlet and is transported to the lower chamber of the working cylinder 400 through the first oil circuit. At this time, the high-pressure oil acts on the lower side of the piston of the working cylinder 400, pushing the piston upward, thereby driving the jet cutter 410 to lift. At the same time, the low-pressure oil in the upper chamber of the working cylinder 400 flows back to the oil return port through the second oil circuit and the second oil port, and finally returns to the oil tank 110, realizing the circulation of the hydraulic oil. This design makes full use of the high power density and high-precision control characteristics of the hydraulic system, so that the lifting action of the jet cutter 410 is smooth and precise.

[0043] Specifically, the oil inlet is connected to the second oil port, the oil return port is connected to the first oil port, the other end of the second oil port is connected to the upper chamber of the working cylinder 400, the lower chamber of the working cylinder 400 is connected to the oil return port through the first oil port, and the working cylinder 400 drives the jet punch 410 to descend.

[0044] The oil inlet is connected to the second oil port, the oil return port is connected to the first oil port, the other end of the second oil port is connected to the upper chamber of the working oil cylinder 400, and the lower chamber of the working oil cylinder 400 is connected to the oil return port through the first oil port. This technical solution ensures that the oil can flow smoothly during the descent of the jet punching knife 410 through a reasonable oil circuit design, thereby realizing effective control of the descent process of the jet punching knife 410. At this time, the reversing valve 100 is hit in the left position, and the high-pressure oil enters from the oil inlet, and the oil inlet is connected to the second oil port. The high-pressure oil enters the second oil circuit from the second oil port and reaches the upper chamber of the working oil cylinder 400. The high-pressure oil pushes the piston downward, and the low-pressure oil goes from the lower chamber of the working oil cylinder 400 through the first oil circuit to the first oil port. The first oil port is connected to the oil return port, and the oil return port is connected to the oil tank 110. The low-pressure oil enters the first oil port and is connected to the oil return port and finally returns to the oil tank 110, so that the working oil cylinder 400 can drive the jet punching knife 410 to descend.

[0045] The first oil port is connected to the second oil port, the other end of the first oil port is connected to the lower chamber of the working cylinder 400, and the other end of the second oil port is connected to the upper chamber of the working cylinder 400. The working cylinder 400 drives the jet punch 410 to maintain the working height.

[0046] The system achieves pressure balance in the hydraulic circuit through the interconnected design of the upper chamber and the lower chamber, the first oil port and the second oil port of the working cylinder 400, combined with the mid-position locking function of the reversing valve 100, ensuring that the jet cutter 410 can stably maintain the set height, thereby improving the operation accuracy and meeting the requirements of complex underwater environments.

[0047] Specifically, the upper chamber and the lower chamber of the working oil cylinder 400 are connected to the first oil port and the second oil port through the oil circuit respectively. When the power is turned on, the reversing valve 100 switches to different positions as needed to control the flow direction of the pressure oil to realize the lifting or lowering action of the jet cutter 410. When the jet cutter 410 reaches the required working height, the reversing valve 100 switches to the middle position. At this time, the connection between the oil inlet and the oil tank 110 is closed, and the entire hydraulic circuit enters a closed state. Due to the formation of the first oil circuit and the second oil circuit, the upper chamber and the lower chamber of the working oil cylinder 400, the first oil port and the second oil port A closed cycle is formed in which the oil circulates in the loop without high-pressure oil flowing in or out of the loop, so the pressure in the system remains balanced, and the jet cutter 410 can be stably maintained at the set height without position change due to pressure fluctuations or oil leakage; through the neutral locking function of the reversing valve 100 and the closed design of the loop, the system can effectively maintain the stability of the jet cutter 410 during operation and avoid height deviation problems caused by external pressure fluctuations or internal pressure imbalance, which helps to improve the accuracy and quality of underwater operations.

[0048] A second one-way valve 520 is provided between the accumulator 500 and the reversing valve 100 .

[0049] When the system is powered on and the oil tank 110 is supplied with oil, part of the hydraulic oil flows to the working end, and the other part flows to the accumulator 500 through the energy storage circuit 550 for energy storage. The setting of the second one-way valve 520 allows the hydraulic oil to only reach the accumulator 500 from the oil tank 110, while the hydraulic oil in the accumulator 500 cannot flow back into the oil tank 110 through the energy storage circuit 550. The purpose of such a design is to prevent the hydraulic oil in the accumulator 500 from flowing back into the oil tank 110 when the pressures of the accumulator 500 and the oil tank 110 are different.

[0050] The accumulator 500 is provided with a maintenance pressure relief valve 540 for maintenance of the accumulator 500 .

[0051] In the hydraulic system of the underwater trencher, the accumulator 500 is used as a storage unit for pressure oil, and high-pressure liquid and pre-charged air are usually stored inside it. If the accumulator 500 is directly disassembled or operated during maintenance without releasing the internal pressure first, it will cause high-speed spraying of hydraulic oil or other dangerous situations, threatening the safety of the operator. Therefore, the maintenance pressure relief valve 540 is set on the accumulator 500 to provide a special pressure relief channel, which can safely release the high-pressure oil inside the accumulator 500 to the oil tank 110 or other safe receiving containers before maintenance. In this way, while ensuring the safety of the system, it also avoids damage to the equipment caused by sudden pressure release; further, the maintenance pressure relief valve 540 is manual. The implementation method of the manual maintenance pressure relief valve 540 includes installing a manually operated pressure relief valve at an appropriate position of the accumulator 500, and controlling the pressure relief process through manual operation. This method is simple and easy, has high reliability, and is suitable for various working environments. As a preferred implementation, the manual maintenance pressure relief valve 540 can adopt a knob-type design, and the operator only needs to rotate the knob to achieve the pressure relief operation, which is convenient and safe to operate.

[0052] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An underwater trenching machine system, comprising a jet cutter (410), characterized in that: The invention comprises a reversing valve (100), a valve (200), a working oil cylinder (400) and an accumulator (500), wherein the valve (200) and the reversing valve (100) are connected to an oil tank (110), the driving end of the working oil cylinder (400) is connected to the jet punching knife (410), the reversing valve (100) comprises an oil inlet, a working end and an oil return port, the oil return port is respectively connected to the oil inlet and the oil tank (110), the working oil cylinder (400) is connected to the working end, the accumulator (500) is connected to the working oil cylinder (400), and a first check valve (510) is provided on the oil path between the accumulator (500) and the working oil cylinder (400); When the valve (200) is powered on, the two ends of the working end are connected / disconnected with the oil inlet and the oil return port respectively, and the jet cutter (410) is lifted / lowered / maintained in height; when the valve (200) is powered off, the accumulator (500) is connected with the lower chamber of the working oil cylinder (400), and the jet cutter (410) is reset.

2. The underwater trenching machine system according to claim 1, characterized in that: The reversing valve (100) is connected to the accumulator (500) via an energy storage circuit (550); when the valve (200) is energized, the energy storage circuit (550) is connected, and the accumulator (500) stores pressurized oil.

3. The underwater trenching machine system according to claim 1, characterized in that: A flow regulating valve (530) is provided between the first one-way valve (510) and the working oil cylinder (400) for regulating and controlling the speed of lifting / lowering / resetting the jet punch (410).

4. The underwater trenching machine system according to claim 1, characterized in that: The working end includes a first oil port and a second oil port, the oil inlet is connected to the first oil port, the oil return port is connected to the second oil port, the other end of the first oil port is connected to the lower chamber of the working cylinder (400), the upper chamber of the working cylinder (400) is connected to the oil return port through the second oil port, and the working cylinder (400) drives the jet punch (410) to lift.

5. The underwater trenching machine system according to claim 4, characterized in that: The oil inlet is connected to the second oil port, the oil return port is connected to the first oil port, the other end of the second oil port is connected to the upper chamber of the working cylinder (400), the lower chamber of the working cylinder (400) is connected to the oil return port through the first oil port, and the working cylinder (400) drives the jet punch (410) to descend.

6. The underwater trenching machine system according to claim 4, characterized in that: The first oil port is connected to the second oil port, the other end of the first oil port is connected to the lower chamber of the working oil cylinder (400), and the other end of the second oil port is connected to the upper chamber of the working oil cylinder (400), and the working oil cylinder (400) drives the jet punch (410) to maintain a working height.

7. The underwater trencher system according to claim 1, characterized in that: A second one-way valve (520) is provided between the accumulator (500) and the reversing valve (100).

8. The underwater trencher system according to claim 7, characterized in that: The accumulator (500) is provided with a maintenance pressure relief valve (540) for maintenance of the accumulator (500).

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