Crawler hydraulic tensioning system, control method thereof and engineering machine

Abstract

The application discloses a caterpillar hydraulic tensioning system, a control method thereof and an engineering machine, and relates to the technical field of engineering machines. The tensioning system detects the running state of the whole machine through a running state detection unit, and performs logical switching according to the running state of the whole machine by a logic control unit, so that when the whole machine has no running action, the hydraulic tensioning system is pre-tensioned at low pressure and the accumulator is cut off, and when the whole machine is in a running state, the hydraulic tensioning system is lifted to a higher range and the accumulator is connected, thereby providing dynamic buffering for caterpillar tensioning. Thus, the problems of poor working condition adaptability of the tensioning system, fast component wear and potential safety hazards caused by the control mode of tensioning control of the engineering machine by using fixed tensioning force or manual adjustment of tensioning force are solved.

Description

Technical Field

[0001] This application relates to the field of engineering machinery technology, and more specifically, to a tracked hydraulic tensioning system and its control method, and engineering machinery. Background Technology

[0002] In the field of construction machinery, especially for ultra-large hydraulic excavators and other construction machinery, the hydraulic tensioning system mostly adopts a control method of fixed tension force or manual adjustment of tension force.

[0003] It is known that using a fixed tension control method makes it difficult for construction machinery to handle low-load impacts during movement, leading to a sharp increase in tension as the load increases and the possibility of tooth skipping under extreme conditions. When not moving, maintaining a consistently high tension exacerbates wear on drive wheel teeth and increases track pitch, thus shortening the service life of the tensioning system. Furthermore, when disassembling and transporting construction machinery, high-pressure tension can cause tracks, track rollers, idlers, and tensioning cylinders to be under high load for extended periods, potentially causing track deformation and posing safety hazards. While manual tension adjustment allows for tension control compared to a fixed tension method, it lacks the ability to quickly switch pressures and is cumbersome to operate. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide a tracked hydraulic tensioning system and its control method and engineering machinery, so as to solve the problems of poor adaptability of the tensioning system, rapid wear of components and safety hazards caused by using a fixed tensioning force or manually adjustable tensioning force control method to control the tensioning of engineering machinery.

[0005] In a first aspect, the present invention provides a tracked hydraulic tensioning system, comprising: At least one tensioning actuator is used to provide tension to the tracks; A hydraulic supply and regulation circuit, connected to the tensioning actuator, is used to change the pressure transmitted to the tensioning actuator. The hydraulic supply and regulation circuit includes at least one accumulator. The walking status detection unit is used to detect the overall walking status of the machine; and A logic control unit is connected to the walking state detection unit and the hydraulic supply and regulation circuit. The logic control unit is configured to: when the whole machine is not moving, control the hydraulic supply and regulation circuit to supply and maintain a first working pressure to the tensioning actuator, and at the same time cut off the oil circuit between the at least one accumulator and the tensioning actuator. When the machine is in motion, the hydraulic supply and regulation circuit is controlled to increase the pressure of the tensioning actuator to a second working pressure range higher than the first working pressure, and the at least one accumulator is connected to the tensioning actuator.

[0006] In one possible implementation, the hydraulic supply and regulation circuit includes a pressure pre-charge circuit; The pressure pre-charge circuit is configured to guide a pilot hydraulic oil source, independent of the main travel oil circuit, to the tensioning execution unit when a pre-tensioning command is received, so that the tensioning execution unit performs pre-tensioning when the whole machine is not traveling. The pressure pre-charge circuit includes a hydraulically controlled check valve; The pilot port of the hydraulic check valve is controlled by pilot pressure, and the hydraulic check valve is configured to remain open under pre-tension.

[0007] In one possible implementation, the tensioning actuator is a tensioning cylinder, and an explosion-proof valve is integrated at the rodless chamber port of the tensioning cylinder. The explosion-proof valve is configured to close when a sudden drop in downstream pipeline pressure is detected, thereby locking the hydraulic oil in the rodless chamber of the tensioning cylinder.

[0008] In one possible implementation, the at least one energy storage device includes a first energy storage device and a second energy storage device connected in parallel in the energy storage circuit; A pressure reducing valve is connected in series on the charging and discharging path of the second accumulator, and the pressure reducing valve is used to limit the maximum operating pressure of the second accumulator.

[0009] In one possible implementation, the charging pressure or minimum operating pressure of the first accumulator is set to be higher than the set pressure of the pressure reducing valve, and the minimum operating pressure of the second accumulator is higher than its charging pressure and lower than the set pressure of the pressure reducing valve.

[0010] In one possible implementation, the hydraulic supply and regulation circuit includes a relief valve; The overflow valve has a switchable first overflow pressure setting value and a second overflow pressure setting value; The logic control unit is further configured to: when receiving a signal indicating the driving status, switch the overflow valve to the first overflow pressure setting value; when not receiving a signal indicating the driving status, switch the overflow valve to the second overflow pressure setting value; wherein the first overflow pressure setting value is higher than the second overflow pressure setting value.

[0011] In one possible implementation, the first overflow pressure setting value is greater than the first preset tension force and less than the second preset tension force; the second overflow pressure setting value is greater than the first working pressure; the first preset tension force is the tension force corresponding to the maximum traction force of the whole machine; and the second preset tension force is the tension force that causes the track teeth to skip.

[0012] In one possible implementation, the hydraulic supply and regulation circuit includes an adjustable flow valve; The adjustable flow valve is configured to completely unload the at least one accumulator when the machine is not moving and the adjustable flow valve is open.

[0013] Secondly, the present invention provides a control method for a tracked hydraulic tensioning system, comprising: Acquire signals indicating the overall operating status of the machine; When the signal indicates that the whole machine is not moving, the hydraulic supply and regulation circuit of the control hydraulic tensioning system provides and maintains the first working pressure to the tensioning actuator, and cuts off the oil circuit between all accumulators in the hydraulic supply and regulation circuit and the tensioning actuator. When the signal indicates that the machine is in a driving state, the hydraulic supply and regulation circuit is controlled to provide a second working pressure higher than the first working pressure to the tensioning actuator, and at least one accumulator in the hydraulic supply and regulation circuit is connected to the tensioning actuator.

[0014] Thirdly, the present invention provides an engineering machine, including a frame and tracks, and a tracked hydraulic tensioning system provided in the first aspect of the present invention, wherein the tensioning execution unit of the tracked hydraulic tensioning system is connected to the track drive.

[0015] The tracked hydraulic tensioning system provided by this invention detects the overall machine's travel status through a travel status detection unit. A logic control unit then performs logical switching based on this travel status. When the machine is not traveling (i.e., in a non-traveling state), the hydraulic tensioning system pre-tensions at low pressure and disconnects the accumulator, thus preventing accelerated wear of components due to prolonged high pressure during stationary operations such as fixed-point work, dismantling, and transportation. When the machine is traveling, the hydraulic tensioning system increases the pressure to a higher range and connects the accumulator, providing dynamic buffering for track tensioning. This ensures smooth operation under low loads and effectively prevents tooth skipping under high loads. In essence, it eliminates the conflicting requirements of non-traveling and traveling operations regarding hydraulic tensioning strategies, achieving adaptive tensioning control under both traveling and non-traveling conditions, significantly improving the service life and reliability of the track tensioning system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 The diagram shown is a structural schematic of the tracked hydraulic tensioning system provided in an embodiment of the present invention.

[0018] Figure 2 The diagram shown is a hydraulic circuit schematic of an example of the tracked hydraulic tensioning system provided in this embodiment.

[0019] Figure 3 The diagram shown is a modular operation logic diagram of an example of applying the tracked hydraulic tensioning system provided in the embodiment of the present invention to tracked engineering machinery.

[0020] Figure 4 The diagram shown is a schematic representation of the tracked hydraulic tensioning system under assembly line conditions, as provided in an embodiment of the present invention.

[0021] Figure 5 The diagram shown is a schematic representation of the tracked hydraulic tensioning system under non-traveling conditions, as provided in an embodiment of the present invention.

[0022] Figure 6 The diagram shown is a schematic representation of the tracked hydraulic tensioning system under low-load walking conditions, as provided in an embodiment of the present invention.

[0023] Figure 7 The diagram shown is a schematic representation of the tracked hydraulic tensioning system under high-load walking conditions, as provided in an embodiment of the present invention.

[0024] Figure 8 The diagram shown is a schematic representation of the tracked hydraulic tensioning system under extreme tooth skipping conditions, as provided in an embodiment of the present invention.

[0025] Figure 9 The diagram shows a flowchart of a control method for a tracked hydraulic tensioning system provided in an embodiment of the present invention.

[0026] Figure 10 The diagram shown is a structural schematic of an electronic device provided in an embodiment of the present invention.

[0027] Figure label: 1: Tensioning cylinder; 2: Shut-off valve; 3: Adjustable flow valve; 4: First check valve; 5: Hydraulic directional valve; 6: Relief valve; 7: Hydraulic check valve; 8: First accumulator; 9: Second accumulator; 10: First pressure reducing valve; 11: Second check valve; 12: Shuttle valve; 13: Second pressure reducing valve; 14: Third check valve. Detailed Implementation

[0028] Unless otherwise defined, the technical or scientific terms used in the embodiments of this specification shall have the ordinary meaning understood by one of ordinary skill in the art to which this specification pertains. The terms "first," "second," and similar terms used in the embodiments of this specification do not indicate any order, quantity, or importance, but are merely used to avoid confusion of constituent elements.

[0029] Unless the context otherwise requires, throughout this specification, "a plurality of" means "at least two," and "including" is interpreted as open-ended or encompassing, that is, "including, but not limited to." In the description of this specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this specification. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example.

[0030] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification.

[0031] Understandably, in the field of engineering machinery technology, the common practice for tensioning tracks and providing cushioning is to install tensioning cylinders in a hydraulic tensioning system. Pressure is then supplied to the tensioning cylinders via a hydraulic circuit, and an accumulator is installed in the circuit to absorb the impact loads generated during movement. In related technologies, to overcome the problems of control methods using fixed tension or manual tension adjustment, automatic tension adjustment control methods have also emerged. This control method switches the system pressure based on the detected hydraulic circuit pressure value. For example, when the pressure reaches a certain threshold, it switches to different pressure modes or activates the accumulator. In other words, it adjusts the system pressure to adapt to different loads and maintain track tension.

[0032] However, because this control method relies on system pressure as the switching basis, it is difficult to distinguish whether the machine is currently in a stationary, non-walking state or a walking state. For construction machinery with frequent alternation of working conditions, such as ultra-large tracked excavators, during non-walking operations (such as excavation, transportation, and dismantling), the hydraulic circuit often maintains a high pressure and keeps the accumulator and tension cylinder connected, causing the tension cylinder, idler wheel, and drive wheel teeth to bear high loads for a long time, resulting in accelerated static wear. During walking operations, a single buffering strategy is difficult to simultaneously absorb low-load impacts (such as periodic small impacts caused by the track polygon effect) and prevent tooth skipping during high-load impacts (such as climbing slopes and overcoming obstacles).

[0033] This application aims to solve the aforementioned problems by introducing a walking state detection unit to detect the overall machine's walking state. A logic control unit then executes a binary logic switch based on this state. Specifically, when the machine is not moving, the hydraulic supply and regulation circuit provides and maintains a first working pressure sufficient to prevent track slippage to the tensioning actuator, while cutting off the oil circuit between the accumulator and the tensioning actuator. This eliminates static wear caused by continuous high-pressure oil supply to the accumulator when the machine is not moving. Conversely, when the machine is moving, the pressure of the tensioning actuator is increased to a second working pressure range higher than the first working pressure, and the accumulator and tensioning actuator are connected, providing dynamic buffering for the walking process. Thus, by providing a hydraulic tensioning control method based on an active pressure switching strategy and buffering intervention according to the machine's walking state, the problem of the track tensioning system's inability to automatically adapt pressure and buffering between non-walking and walking conditions is solved, achieving the technical effect of optimizing component wear and walking buffering performance at different operating stages.

[0034] Figure 1 This is a schematic diagram of the tracked hydraulic tensioning system provided in an embodiment of the present invention. This hydraulic tensioning system is built onto tracked construction machinery to provide variable tension and cushioning to the tracks under various operating conditions. Figure 1 As shown, the hydraulic tensioning system mainly includes: at least one tensioning execution unit 101, a hydraulic supply and adjustment circuit 201, a travel status detection unit 301, and a logic control unit 401.

[0035] At least one tensioning actuator 101 is used to provide tension force to the track; The hydraulic supply and regulation circuit 201 is connected to the tensioning actuator 101 and is used to change the pressure transmitted to the tensioning actuator 101. The hydraulic supply and regulation circuit 201 includes at least one accumulator. The walking status detection unit 301 is used to detect the overall walking status of the machine; and The logic control unit 401 is connected to the walking state detection unit 301 and the hydraulic supply and regulation circuit 201. The logic control unit 401 is configured to: when the whole machine is not moving, control the hydraulic supply and regulation circuit 201 to supply and maintain a first working pressure to the tensioning execution unit 101, and at the same time cut off the oil circuit between at least one accumulator and the tensioning execution unit 101. When the machine is in motion, the hydraulic supply and regulation circuit 201 controls the pressure of the tensioning actuator 101 to a second working pressure range higher than the first working pressure, and connects at least one accumulator to the tensioning actuator 101.

[0036] In some possible embodiments, the tensioning actuator 101 employs a single-acting piston cylinder, with its cylinder body hinged to the track frame of the working machinery and its piston rod rigidly connected to the idler wheel bracket, thereby applying tension force directly to the track by driving the idler wheel to move. The hydraulic supply and regulation circuit 201 is hydraulically connected to the rodless chamber of the single-acting piston cylinder. This circuit integrates a hydraulic power source, a pressure regulating valve assembly, and an energy storage circuit consisting of at least one accumulator. The hydraulic power source provides stable hydraulic oil, and the pressure regulating valve assembly transmits different working pressures to the single-acting piston cylinder by changing the flow path and pressure setpoint. The energy storage circuit absorbs pressure shocks and provides auxiliary tension force when in the on state.

[0037] The walking status detection unit 301 is installed in the overall machine control network to detect whether the machine is in a walking state. The logic control unit 401 is electrically or hydraulically pilot-connected to the walking status detection unit 301 and the controlled components of the hydraulic supply and regulation circuit 201. This allows the logic control unit 401 to receive signals from the walking status detection unit and, based on the signal content, switch the valves inside the hydraulic supply and regulation circuit 201 to change the pressure supply state transmitted to the tensioning actuator 101 and the accumulator's engagement state. For example, in the non-walking state, the system maintains a relatively low first working pressure, and the accumulator circuit is isolated from the tensioning actuator 101 under valve group control; while in the walking state, the system pressure is increased to a higher second working pressure range, and the accumulator circuit is activated to provide dynamic buffering capability for the system.

[0038] Figure 2 This is a schematic diagram of the hydraulic circuit for an example of the tracked hydraulic tensioning system provided in this embodiment. See also... Figure 2 In this example, the tensioning actuator is specifically a single-acting piston tensioning cylinder 1. Its cylinder body is hinged to the track frame of the construction machinery, and the piston rod is rigidly connected to the guide wheel bracket, allowing the displacement of the drive guide wheel to directly apply tension to the track. The extension and retraction of the tensioning cylinder 1 changes the track tension, thereby achieving continuous adjustment of the tension.

[0039] A hydraulic supply and regulation circuit is connected to the tensioning actuator to change the pressure transmitted to the tensioning actuator. This circuit includes at least one accumulator. Figure 2 In the example shown, the hydraulic supply and regulation circuit integrates a hydraulic power source (not shown), a pressure regulating valve group, and an accumulator circuit consisting of a first accumulator 8 and a second accumulator 9 connected in parallel. The hydraulic power source provides stable hydraulic oil, while the pressure regulating valve group transmits different working pressures to the rodless chamber of the tensioning cylinder 1 by changing the internal oil circuit on / off state and the overflow setpoint. The accumulator circuit is connected to or disconnected from the tensioning cylinder 1 through a hydraulically controlled directional valve 5, thereby absorbing impact pressure and assisting in providing tension force in the connected state, and isolating the accumulator's influence on the system in the disconnected state. It can be understood that the number of accumulators can be increased or decreased according to actual needs, for example, by setting a single accumulator or multiple accumulators connected in parallel.

[0040] The travel status detection unit is used to detect the overall travel status of the machine. This unit is located within the overall control network and may include, but is not limited to, a travel pilot pressure sensor, a vehicle speed sensor, an electric control handle switch signal, or a travel flag bit obtained from the vehicle controller bus. It generates a clear binary signal or status word; for example, a high level indicates the machine is in a traveling state, and a low level indicates the machine is not traveling (i.e., in a non-traveling state).

[0041] The logic control unit is connected to the walking status detection unit and the hydraulic supply and regulation circuit, and performs logic switching based on the received signals. Specifically, the logic control unit can be a controller capable of receiving walking pilot pressure signals or electrical signals; it drives the system by outputting control current or pilot pressure. Figure 2 The controlled components, such as the hydraulic directional valve 5 and the relief valve 6, are activated. The logic control unit is configured to: when receiving a signal indicating that the machine is not moving (i.e., in a non-moving state), control the hydraulic supply and regulation circuit to supply and maintain a first working pressure to the tensioning actuator, and simultaneously disconnect the oil circuit between at least one accumulator and the tensioning actuator; and when receiving a signal indicating that the machine is in a moving state, control the hydraulic supply and regulation circuit to increase the pressure of the tensioning actuator to a second working pressure range higher than the first working pressure, and connect at least one accumulator and the tensioning actuator.

[0042] The following is combined with Figure 2The control logic of the logic control unit is described in detail. Taking a super-large excavator as an example, in a non-traveling state, such as when the excavator is stationary or in dismantling and transportation conditions, the travel status detection unit detects that the entire machine is not moving. Based on this, the logic control unit switches the overflow valve 6 to a lower second overflow pressure setting value Ps1 and controls the hydraulic control directional valve 5 to the left position, thus cutting off the oil circuit between the accumulators 8 and 9 and the tensioning cylinder 1. At this time, low-pressure oil from the pressure pre-charge circuit can enter the rodless chamber of the tensioning cylinder 1 through the first check valve 4, the shut-off valve 2, and the hydraulic control check valve 7, establishing and maintaining a relatively low first working pressure. The first working pressure is the pressure value that only prevents track sagging, while the accumulator does not intervene, thereby avoiding static wear and ineffective accumulator charging and discharging caused by long-term high pressure maintenance. In addition, when the logic control unit detects that the system pressure drops due to internal leakage, the pressure pre-charge circuit can replenish oil in time to keep the first working pressure above the preset threshold.

[0043] When the machine is in motion, the travel status detection unit generates a travel signal. Upon receiving this signal, the logic control unit switches the overflow valve 6 to a higher first overflow pressure setting value Ps2, and simultaneously outputs a control signal to switch the hydraulic directional valve 5 to the right position, connecting the oil circuits of accumulators 8 and 9 with the tensioning cylinder 1. High-pressure oil from the main oil circuit is supplied to the tensioning cylinder 1 via shuttle valve 12, second pressure reducing valve 13, third check valve 14, directional valve 5, and shut-off valve 2, raising the system pressure to a second working pressure range higher than the first working pressure. At this time, the accumulator circuit is connected, and the first accumulator 8 and the second accumulator 9 can work with the first pressure reducing valve 10 on the low-pressure side to form a graded buffer mechanism, absorbing the impact caused by the track polygon effect or sudden load changes during travel, and providing dynamic tension force to the tensioning actuator, thus balancing low-load smoothness and high-load anti-tooth skipping requirements.

[0044] It should be noted that the signal provided by the aforementioned walking status detection unit serves as the trigger source for switching the system pressure strategy, directly acting on the logic control unit rather than passively relying on changes in system pressure. This allows the binary control logic, which employs low-pressure holding without buffering for static conditions and high-pressure supply with graded buffering for walking conditions, to be executed accurately and quickly. This fundamentally resolves the contradiction between long-term static wear and dynamic condition adaptation caused by a single high-pressure strategy.

[0045] To further optimize the initial assembly and oil replenishment process under non-walking conditions, in a preferred embodiment, the hydraulic supply and regulation circuit also includes a pressure pre-charge circuit. For example... Figure 2As shown, the pressure pre-charge circuit has a first check valve 4, whose hydraulic port is controlled by pilot pressure. It is configured to, upon receiving a pre-tensioning command, guide a pilot hydraulic oil source independent of the main travel oil circuit to the tensioning cylinder 1 of the tensioning actuator, so that the tensioning cylinder 1 performs pre-tensioning when the machine is not traveling. This first check valve 4 is further limited to remaining open under the pre-tensioning pressure P0.

[0046] Specifically, when the newly assembled construction machinery is started for the first time, the driver turns on the pilot switch, and the pilot pressure oil opens the first check valve 4. The oil then enters the tensioning cylinder 1 through the shut-off valve 2 and the hydraulic control check valve 7 installed at the oil port of the rodless chamber of the tensioning cylinder 1, pushing the piston rod to slowly extend and press the guide wheel onto the track track, so that the track obtains a pre-tension pressure P0 without relying on the travel motor to establish tension, thereby avoiding the risk of derailment that may occur when the track travels in a loose state.

[0047] Furthermore, in the subsequent walking state, the main oil circuit pressure oil is reduced by the second pressure reducing valve 13 and then provides tension force to the tensioning cylinder 1 to meet the track suspension requirements.

[0048] In this embodiment, by setting up a pressure pre-charge circuit, the drawback of the initial tensioning in related technologies that must rely on walking motion is solved, and the system can automatically replenish oil for pressure drop caused by internal leakage in non-walking conditions, thereby further ensuring the reliability of the system.

[0049] It should be noted that the hydraulic oil source for the pressure pre-charge circuit can be from the travel pilot system or from the low-pressure pilot oil circuit of other parts of the construction machinery, as long as it is a pilot hydraulic oil source independent of the main travel oil circuit. No specific limitation is made here.

[0050] To ensure system safety under extreme operating conditions, in another preferred embodiment, the tensioning actuator is a tensioning cylinder, and an explosion-proof valve is integrated at the rodless chamber port of the tensioning cylinder. This explosion-proof valve is configured to close upon detecting a sudden drop in downstream pipeline pressure, thereby locking the hydraulic oil within the rodless chamber of the tensioning cylinder.

[0051] Specifically, the implementation of explosion-proof valves can be as follows: Figure 2 The hydraulically controlled check valve 7 is shown. (As shown...) Figure 2As shown, the hydraulically controlled check valve 7 is directly installed at the rodless chamber port of the tensioning cylinder 1, and its hydraulic control port is connected to the downstream working pipeline through an oil circuit. During normal operation, under the working pressure or pilot pressure from the system, the hydraulically controlled check valve 7 remains open, allowing hydraulic oil to flow in both directions. However, if the pipeline connecting to the tensioning cylinder 1 unexpectedly bursts, causing a sudden drop in downstream pressure, the pressure at the hydraulic control port disappears, and the hydraulically controlled check valve 7 quickly closes under the action of the internal spring force and the pressure within the cylinder chamber, locking the hydraulic oil in the rodless chamber, thereby maintaining the track tension and preventing track slippage that could lead to a safety accident.

[0052] It should be noted that, Figure 2 The hydraulically controlled check valve shown is only one specific implementation of the explosion-proof valve. Differential pressure controlled two-position two-way valves, diaphragm explosion-proof valves, etc. can also be used, and no specific limitation is made here.

[0053] To further refine the accumulator's buffering characteristics, in a preferred embodiment, the aforementioned at least one accumulator includes a first accumulator and a second accumulator connected in parallel in the accumulator circuit, wherein a pressure reducing valve is connected in series on the charging / discharging path of the second accumulator, the pressure reducing valve being used to limit the maximum operating pressure of the second accumulator.

[0054] Specifically, by setting such as Figure 2 The first accumulator 8 and the second accumulator 9 are connected in parallel in the accumulator circuit, and a first pressure reducing valve 10 is connected in series in the charging and discharging path of the second accumulator 9, forming a graded buffer structure composed of a high-pressure accumulator and a low-pressure accumulator. This allows the low-pressure second accumulator 9 to flexibly absorb shocks in a lower pressure range, while the first accumulator 8 rigidly resists higher pressure shocks.

[0055] Specifically, in combination Figure 2Under low-load traveling conditions, the periodic small impacts generated by the polygonal effect of the track cause the piston rod of the tensioning cylinder 1 to extend and retract within a small range. The hydraulic oil in its rodless chamber flows to the second accumulator 9 via the hydraulically controlled check valve 7, the shut-off valve 2, the reversing valve 5, and the first pressure reducing valve 10. The second accumulator 9 operates within a pressure range lower than that set by the first pressure reducing valve 10, absorbing impacts and regulating tension. When an occasional large impact causes the system pressure to exceed the set pressure of the first pressure reducing valve 10, the high-pressure first accumulator 8 automatically intervenes, instantly providing higher tension to prevent track skipping. Under high-load traveling conditions, the driving force is greater, and the greater the pressure F on the piston rod of the tensioning cylinder 1, the greater the compression stroke of the piston rod. At this time, the accumulator 9 is already at its maximum working pressure P3 under the action of the first pressure reducing valve 10, and stops working after reaching the maximum compression. The hydraulic oil in the rodless chamber of tension cylinder 1 mainly flows to the first accumulator 8. After the first accumulator 8 is filled with fluid, the pressure rises further, providing a greater tension force to tension cylinder 1 to ensure that the track teeth do not skip. When the first accumulator 8 reaches a certain compression, the tension force provided to the tension cylinder satisfies the load F on the cylinder under the maximum driving force limit climbing state of the engineering machinery. At this time, the stroke of tension cylinder 1 being compressed is less than the stroke required for the track teeth to skip.

[0056] Furthermore, under extreme tooth skipping conditions, if the track teeth are blocked by hard objects, preventing the drive wheel teeth from engaging, the piston rod of tension cylinder 1 is compressed to its limit, further increasing the system pressure. This pressure has not yet reached the rated pressure of the first accumulator 8, but it is higher than the set pressure Ps2 of the relief valve 6. Therefore, the relief valve 6 opens to overflow, and the system pressure no longer rises further. Once the tooth skipping phase ends, due to the high filling pressure of the first accumulator 8, the hydraulic oil in the rodless chamber of tension cylinder 1 pushes the piston rod to the right, and the main oil circuit replenishes the system with oil in a timely manner. This staged buffering allows for seamless transitions without active control, balancing low-load smoothness with high-load anti-tooth skipping requirements.

[0057] Based on this, a preferred parameter coordination relationship is: the charging pressure or minimum working pressure of the first accumulator is set to be higher than the set pressure of the pressure reducing valve, and the minimum working pressure of the second accumulator is higher than its charging pressure and lower than the set pressure of the pressure reducing valve.

[0058] Specifically, by setting these pressure parameters, the second accumulator 9 absorbs small impacts such as polygon effects only in its dedicated low-pressure operating range. When the pressure exceeds the threshold of the first pressure reducing valve 10, the path is restricted. At this time, the first accumulator 8, i.e. the high-pressure accumulator, will automatically take over the subsequent high-pressure impact, thus achieving seamless, sequential, graded buffering from low pressure to high pressure.

[0059] It should be noted that the specific values ​​of the inflation pressure and the pressure reducing valve setting can be adjusted according to the model of the construction machinery and the expected working conditions. For example, the inflation pressure P02 of the first accumulator 8 can be set to be much greater than the setting pressure P3 of the first pressure reducing valve 10, while the minimum working pressure P1 of the second accumulator 9 satisfies P1>P01 and P1 <P3。

[0060] To reliably switch the system overflow protection level between walking and non-walking operating conditions, the hydraulic supply and regulation circuit also includes, for example: Figure 2 The overflow valve 6 is shown.

[0061] The overflow valve 6 has a switchable first overflow pressure setting and a second overflow pressure setting.

[0062] The logic control unit is further configured to: when receiving a signal indicating the driving status, switch the overflow valve 6 to a higher first overflow pressure setting value; when not receiving a signal indicating the driving status, switch the overflow valve 6 to a lower second overflow pressure setting value, wherein the first overflow pressure setting value is higher than the second overflow pressure setting value.

[0063] See Figure 2 The overflow valve 6 can be switched by pilot pressure or electromagnet. When the travel status detection unit outputs a travel signal, the logic control unit outputs control pressure or electrical signal to switch the overflow valve 6 to the high pressure limit, ensuring that the system can build up a sufficiently high tension force under travel conditions to cope with drive wheel tooth cutting and anti-tooth skipping; while under non-travel conditions, it switches to the low pressure limit, and the system pressure is limited to near the lower second overflow pressure setting value. In conjunction with the reversing valve 5 to cut off the accumulator circuit, the tensioning system maintains only low pressure pretension for a long time, thereby reducing the static load and wear of components.

[0064] Furthermore, in a preferred embodiment, the first overflow pressure setting value Ps2 is set to be greater than the first preset tension force and less than the second preset tension force; the second overflow pressure setting value Ps1 is greater than the first working pressure.

[0065] Specifically, the first preset tension is the tension corresponding to the maximum traction force of the entire machine, and the second preset tension is the tension that causes the track teeth to skip. With this parameter setting, the system overflow pressure is sufficient to support the maximum driving force during travel without causing pressure leakage due to overflow malfunction, while also limiting the system pressure to not exceed the critical point of tooth skipping, thus avoiding damage to the traveling mechanism due to over-tensioning; while during non-travel, the second overflow pressure setting can both maintain the minimum tension in conjunction with the pressure pre-charge circuit and provide an upper limit for safe pressure relief.

[0066] It should be noted that the specific values ​​of the first and second preset tension forces can be obtained through calculation or calibration, and can be adjusted within an appropriate range according to the specific model in practical applications.

[0067] To meet the requirement of complete unloading under extreme working conditions such as transportation and dismantling, in a preferred embodiment, the hydraulic supply and regulation circuit includes, as follows: Figure 2 The adjustable flow valve 3 is shown. This adjustable flow valve 3 is configured to completely unload at least one accumulator when the entire machine is not moving and the adjustable flow valve is open.

[0068] Specifically, such as Figure 2 As shown, the adjustable flow valve 3 is connected in parallel to the circuit containing the overflow valve 6, or it can be connected to the passage between the reversing valve 5 and the accumulators 8 and 9. When the construction machinery needs to be transported and dismantled, after stopping, the shut-off valve 2 can be closed first, at which time the tension cylinder 1 maintains a low-pressure pre-tension force; then, by opening the adjustable flow valve 3, the high-pressure oil in the accumulators 8 and 9 is slowly discharged to the oil tank through the reversing valve 5 and the throttle valve 3, as well as the second check valve 11, the reversing valve 5 and the throttle valve 3, thereby achieving complete unloading of the system and eliminating the safety hazards of high-pressure oil to dismantling and transportation operations.

[0069] In this embodiment, the automatic switching function of the logic control unit is supplemented by the setting of the adjustable flow valve, which enables the system to automatically switch pressure under normal operating conditions, and to release pressure under special operating conditions such as maintenance and transportation, thereby further improving the system safety.

[0070] Figure 3 This is a modular operation logic diagram illustrating an example of applying the tracked hydraulic tensioning system provided in the above embodiments to tracked construction machinery. Figure 3 As can be seen, the system may include a working condition detection module, a control module, a pressure regulation module, a hydraulic tensioning cylinder, a high and low pressure accumulator module, an explosion-proof protection module, and a tracked walking mechanism. Firstly, the working condition detection module detects whether the construction machinery is in a walking state, then sends the detection signal to the control module. Based on this signal, the control module sends control commands to the pressure regulation module, which then applies control actions to the pressure reducing valve, relief valve, and accumulator to the hydraulic tensioning cylinder, thereby controlling the tracked walking mechanism, including the idler wheels and track rollers. Secondly, the high and low pressure accumulator module, composed of a high-pressure accumulator, a low-pressure accumulator, and a pressure reducing valve, provides tiered buffering for the hydraulic tensioning system of the construction machinery during walking operations. Thirdly, the explosion-proof protection module, composed of a hydraulically controlled check valve and a shut-off valve, closes when a sudden drop in downstream pipeline pressure is detected, locking the hydraulic oil in the rodless chamber of the tensioning cylinder to maintain track tension and prevent track slippage, thus ensuring system safety.

[0071] Therefore, the tracked hydraulic tensioning system provided in the above embodiments can achieve adaptive pressure adjustment for different working conditions. That is, as... Figures 4 to 8As shown, under assembly line conditions, the track is kept pre-tensioned at pressure P0. Under no-travel conditions, the accumulator circuit is disconnected, the accumulator does not work, the overflow valve pressurization is ineffective, and the track maintains the minimum tension, such as the pre-tension pressure P0, and the pressure pre-charge circuit replenishes oil and pressure to the tensioning actuator. Under low-load travel conditions, the track is kept tensioned at pressure P1, the low-pressure accumulator absorbs the polygonal effect impact of the track during travel, and the high-pressure accumulator absorbs the impact load of sudden impacts. Under high-load travel conditions, the low-pressure accumulator reaches the maximum liquid level, and the high-pressure accumulator provides tension and absorbs impact loads. Under extreme tooth skipping conditions, the overflow valve opens to overflow, preventing the system pressure from rising further.

[0072] Figure 9 This is a schematic flowchart of a control method for a tracked hydraulic tensioning system according to the above embodiments of the present invention. The method can be executed by the aforementioned logic control unit alone, or by multiple control modules working together, and mainly includes the following steps: S100: Obtain a signal indicating the overall operating status of the machine.

[0073] S110. When the signal indicates that the whole machine is not moving, the hydraulic supply and regulation circuit of the hydraulic tensioning system is controlled to supply and maintain the first working pressure to the tensioning actuator, and the oil circuits of all accumulators and tensioning actuators in the hydraulic supply and regulation circuit are cut off. S120. When the signal indicates that the whole machine is in the driving state, the control hydraulic supply and regulation circuit provides a second working pressure higher than the first working pressure to the tensioning actuator, and connects at least one accumulator in the hydraulic supply and regulation circuit to the tensioning actuator.

[0074] Specifically, see Figure 2 When the signal indicates that the machine is not moving, the logic control unit can output a command to switch the overflow valve 6 to the second overflow pressure setting value Ps1, and activate the hydraulic control directional valve 5 to cut off the oil circuit of accumulator 8 and accumulator 9. At the same time, the pressure pre-charge circuit is activated to replenish oil to the tension cylinder 1 to maintain the first working pressure, ensuring that the track maintains the minimum tension to prevent sagging. When the signal indicates that the machine is in motion, the logic control unit switches the overflow valve 6 to the first overflow pressure setting value Ps2, and activates the hydraulic control directional valve 5 to connect accumulator 8 and accumulator 9 to the oil circuit of tension cylinder 1. The main oil circuit pressure oil enters the system through the second pressure reducing valve 13, etc., raising the tension pressure to the second working pressure range, achieving dynamic buffering through the accumulator circuit.

[0075] In this embodiment, the binary control logic is directly driven by the driving status signal, achieving low-pressure maintenance and accumulator isolation to reduce wear when not driving, and high-pressure oil supply and accumulator activation during driving to balance low-load impact absorption and high-load anti-tooth skipping. This addresses the contradiction of working condition adaptation in coordination with the aforementioned system embodiments at the control level. The method can further include control methods corresponding to the tracked hydraulic tensioning system provided in any of the aforementioned embodiments. Examples include: control of the pressure pre-charge circuit start / stop, graded pressure management of the dual accumulators, switching management of the overflow valve, and safety unloading logic for the adjustable flow valve.

[0076] This invention also provides an engineering machine, which includes a chassis and tracks, and further includes, for example, Figure 2 The tracked hydraulic tensioning system shown and provided in any of the foregoing embodiments, wherein the tensioning execution unit of the tracked hydraulic tensioning system is connected to the track drive.

[0077] Specifically, the cylinder body of tensioning cylinder 1 is fixed to the rear of the track frame of the vehicle frame, and the piston rod end abuts against the track track via a guide wheel bracket. The tension of the track is indirectly changed by adjusting the position of the guide wheel. Thanks to the aforementioned hydraulic tensioning system with binary control logic and graded buffering function, this construction machinery can achieve adaptive adjustment of tension and buffering characteristics under various working conditions such as excavation, travel, dismantling, and transportation. This significantly reduces wear on the traveling mechanism and improves driving safety and smoothness.

[0078] Below, for reference Figure 10 The electronic device provided in the embodiments of this application can be described as follows: at least one processor 100, at least one communication interface 200, at least one memory 300 and at least one communication bus 400; In this embodiment of the invention, the number of processor 100, communication interface 200, memory 300, and communication bus 400 is at least one, and the processor 100, communication interface 200, and memory 300 communicate with each other through communication bus 400; obviously, Figure 10 The communication connections shown for the processor 100, communication interface 200, memory 300, and communication bus 400 are optional. Optionally, the communication interface 200 can be an interface of a communication module, such as the interface of a GSM module; the processor 100 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0079] The memory 300 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0080] Specifically, the processor 100 is used to execute the application program in the memory to implement the steps of the control method for track hydraulic tensioning described above.

[0081] In addition to the methods, systems, and devices described above, embodiments of this disclosure may also be computer program products, including computer program instructions that, when executed by a processor, cause the processor to perform various steps of the control methods for the tracked hydraulic tensioning system provided in the various embodiments of this disclosure.

[0082] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this disclosure. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on a user's computing device, partially on a user's computing device, as a standalone software package, partially on a user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0083] Furthermore, embodiments of this disclosure may also be storage media (e.g., computer-readable storage media) storing a computer program (or instructions) thereon, which, when run by a processor, causes the processor to execute the various steps of the control method for the tracked hydraulic tensioning system provided in the various embodiments of this disclosure.

[0084] The storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0085] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0086] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0087] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0088] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0089] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0090] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A tracked hydraulic tensioning system, characterized in that, include: At least one tensioning actuator is used to provide tension to the tracks; A hydraulic supply and regulation circuit, connected to the tensioning actuator, is used to change the pressure transmitted to the tensioning actuator. The hydraulic supply and regulation circuit includes at least one accumulator. The walking status detection unit is used to detect the overall walking status of the machine; as well as A logic control unit is connected to the walking state detection unit and the hydraulic supply and regulation circuit. The logic control unit is configured to: when the whole machine is not moving, control the hydraulic supply and regulation circuit to supply and maintain a first working pressure to the tensioning actuator, and at the same time cut off the oil circuit between the at least one accumulator and the tensioning actuator. When the machine is in motion, the hydraulic supply and regulation circuit is controlled to increase the pressure of the tensioning actuator to a second working pressure range higher than the first working pressure, and the at least one accumulator is connected to the tensioning actuator.

2. The system according to claim 1, characterized in that, The hydraulic supply and regulation circuit includes a pressure pre-charge circuit; The pressure pre-charge circuit is configured to guide a pilot hydraulic oil source, independent of the main travel oil circuit, to the tensioning execution unit when a pre-tensioning command is received, so that the tensioning execution unit performs pre-tensioning when the whole machine is not traveling. The pressure pre-charge circuit includes a hydraulically controlled check valve; The pilot port of the hydraulic check valve is controlled by pilot pressure, and the hydraulic check valve is configured to remain open under pre-tension.

3. The system according to claim 1, characterized in that, The tensioning actuator is a tensioning cylinder, and an explosion-proof valve is integrated at the oil port of the rodless chamber of the tensioning cylinder; The explosion-proof valve is configured to close when a sudden drop in downstream pipeline pressure is detected, thereby locking the hydraulic oil in the rodless chamber of the tensioning cylinder.

4. The system according to claim 1, characterized in that, The at least one energy storage device includes a first energy storage device and a second energy storage device connected in parallel in the energy storage device circuit; A pressure reducing valve is connected in series on the charging and discharging path of the second accumulator, and the pressure reducing valve is used to limit the maximum operating pressure of the second accumulator.

5. The system according to claim 4, characterized in that, The charging pressure or minimum operating pressure of the first accumulator is set to be higher than the set pressure of the pressure reducing valve, and the minimum operating pressure of the second accumulator is higher than its charging pressure and lower than the set pressure of the pressure reducing valve.

6. The system according to claim 1, characterized in that, The hydraulic supply and regulation circuit includes a relief valve; The overflow valve has a switchable first overflow pressure setting value and a second overflow pressure setting value; The logic control unit is further configured to: when receiving a signal indicating the driving status, switch the overflow valve to the first overflow pressure setting value; when not receiving a signal indicating the driving status, switch the overflow valve to the second overflow pressure setting value; wherein the first overflow pressure setting value is higher than the second overflow pressure setting value.

7. The system according to claim 6, characterized in that, The first overflow pressure setting value is greater than the first preset tension force and less than the second preset tension force; the second overflow pressure setting value is greater than the first working pressure; the first preset tension force is the tension force corresponding to the maximum traction force of the whole machine; and the second preset tension force is the tension force that causes the track teeth to skip.

8. The system according to claim 1, characterized in that, The hydraulic supply and regulation circuit includes an adjustable flow valve; The adjustable flow valve is configured to completely unload the at least one accumulator when the machine is not moving and the adjustable flow valve is open.

9. A control method for a tracked hydraulic tensioning system, characterized in that, include: Acquire signals indicating the overall operating status of the machine; When the signal indicates that the whole machine is not moving, the hydraulic supply and regulation circuit of the control hydraulic tensioning system provides and maintains the first working pressure to the tensioning actuator, and cuts off the oil circuit between all accumulators in the hydraulic supply and regulation circuit and the tensioning actuator. When the signal indicates that the machine is in a driving state, the hydraulic supply and regulation circuit is controlled to provide a second working pressure higher than the first working pressure to the tensioning actuator, and at least one accumulator in the hydraulic supply and regulation circuit is connected to the tensioning actuator.

10. An engineering machine, comprising a frame and tracks, characterized in that, It also includes a tracked hydraulic tensioning system as described in any one of claims 1 to 8, wherein the tensioning actuation unit of the tracked hydraulic tensioning system is connected to the track drive.

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