Variable compression ratio hydraulic device and control method

Abstract

The application provides a variable compression ratio hydraulic device and a control method. The variable compression ratio hydraulic device comprises a transmission module, an extension assembly, a clamping and locking mechanism, a hydraulic module and a control module. The extension assembly comprises a sliding core and a piston rod, the sliding core is provided with a concave cavity, the concave cavity is used for dividing the hydraulic oil cavity into a low-pressure oil cavity and a high-pressure oil cavity, and the high-pressure oil cavity is provided with a self-locking mechanism. By arranging the double-acting hydraulic oil cavity, the self-locking mechanism and the clamping and locking mechanism, the variable compression ratio hydraulic device can be effectively controlled and adjusted, and the performance of the device is improved.

Description

Technical Field

[0001] This application relates to the field of variable compression ratio hydraulic devices, and more specifically, to a variable compression ratio hydraulic device and control method for marine low-speed engines. Background Technology

[0002] In the traditional mechanical structure of an engine, the piston can only work between fixed top dead center and bottom dead center, and the engine compression ratio is a fixed geometric compression ratio. When using the traditional fixed geometric compression ratio (CR), the ignition pressure of the engine will decrease when running under partial load, resulting in reduced engine efficiency and poor fuel economy.

[0003] To improve engine performance under various operating conditions and fuel combustion scenarios, variable compression ratio (VCR) systems represent a promising alternative technology. However, marine low-speed engines employ a fixed geometric compression ratio, resulting in poor overall performance in terms of output torque, combustion economy, and emissions under partial load and multi-fuel mixed conditions. This makes it difficult to meet the demands of multi-fuel mixed combustion and national environmental protection requirements. For marine low-speed engines, due to their structural differences from medium- and high-speed engines and their long-term heavy-load operation, altering their compression ratio using methods similar to those used for medium- and high-speed engines would lead to complex mechanisms, poor load-bearing capacity, and severe wear. Therefore, there is an urgent need to develop a highly reliable, low-cost, and fuel-efficient variable compression ratio (VCR) system for marine low-speed engines, ensuring that engine output torque, combustion economy, and emissions meet requirements without reducing power, thus optimizing engine performance. Summary of the Invention

[0004] This application addresses the shortcomings of existing methods by proposing a variable compression ratio hydraulic device and control method for marine low-speed engines, thereby solving the technical problems of unsatisfactory compression ratio and working performance of existing hydraulic devices.

[0005] This application provides a variable compression ratio hydraulic device, including: The transmission module includes at least a hydraulic oil chamber; A telescopic assembly, at least a portion of which is disposed within the hydraulic oil chamber, the telescopic assembly including a sliding core and a piston rod slidable relative to the hydraulic oil chamber, the sliding core having a recessed cavity for dividing the hydraulic oil chamber into a low-pressure oil chamber and a high-pressure oil chamber, and the high-pressure oil chamber having a self-locking mechanism; A clamping and locking mechanism engages with the piston rod. The clamping and locking mechanism includes multiple guide rail slider groups, multiple clamping plates, and multiple actuating cylinders. The clamping plates are disposed on the guide rail slider groups. The actuating cylinders are disposed correspondingly to the clamping plates and are used to drive the clamping plates to move. The clamping and locking mechanism and the self-locking mechanism are used to control the self-locking and unlocking of the telescopic component. A hydraulic module, connected to the telescopic assembly and used to drive the telescopic assembly to move; and, A control module, which is used to control the hydraulic module.

[0006] According to one embodiment of this application, the transmission module further includes a pin, a housing, an end cap, a first seal, and a second seal; The pin has an inner cavity, which together with the housing and end cap forms the hydraulic oil chamber. The housing is located at the upper end of the pin. The first seal is located in the area where the pin contacts the housing, and the second seal is located in the area where the end cap contacts the housing.

[0007] According to one embodiment of this application, an oil inlet groove is further provided at the bottom of the inner cavity.

[0008] According to one embodiment of this application, the self-locking mechanism includes a stop post, and ball joints and a return spring respectively disposed on both sides of the stop post.

[0009] According to one embodiment of this application, the sliding core further includes a first protrusion and a second protrusion; The first protrusion is provided with a locking groove, the second protrusion is connected to the piston rod, and the cavity is provided with a sealing ring, which is used to divide the hydraulic oil chamber into the low-pressure oil chamber and the high-pressure oil chamber.

[0010] According to one embodiment of this application, the low-pressure oil chamber is provided with a first oil inlet and a first oil outlet; the high-pressure oil chamber is provided with a second oil inlet and a second oil outlet; the upper end of the piston rod is connected to the engine piston, a convex ring is provided in the middle part of the piston rod, and a groove is also provided on the convex ring, the groove engaging with the clamping and locking mechanism.

[0011] According to one embodiment of this application, the clamping and locking mechanism further includes a support base, a first guide rail slider group, a second guide rail slider group, a first clamping piece, a second clamping piece, a first actuating cylinder, a second actuating cylinder, a proximity sensor, and a sensor bracket. The support base is disposed on the end cover. The first guide rail slider group and the second guide rail slider group are both disposed on the support base. The first guide rail slider group includes a first guide rail, a first slider, and a second slider. The second guide rail slider group includes a second guide rail, a third slider, and a fourth slider. The first slider and the third slider are bridged with a first clamping piece. The second slider and the fourth slider are bridged with a second clamping piece. The first clamping piece and the second clamping piece are provided with a first actuating cylinder and a second actuating cylinder. One end of the first actuating cylinder is fixed to the first end of the first clamping piece and the second clamping piece. One end of the second actuating cylinder is fixed to the second end of the first clamping piece and the second clamping piece.

[0012] According to one embodiment of this application, both the first actuating cylinder and the second actuating cylinder are configured as normally closed spring-reset single-acting finger hydraulic cylinders.

[0013] According to one embodiment of this application, the control module includes a collector, a processor, a controller, and a signal output device; The signal collector is used to collect the pressure values ​​in the oil circuit where the first pressure sensor, the third pressure sensor, the second pressure sensor, and the fourth pressure sensor are located. The processor converts the signals collected by the collector into current signals and sends them to the controller, and transmits them to each solenoid valve through the signal output device. Specifically, when the oil pressure collected by the pressure sensor is lower than a set threshold, the signal value collected by the signal collector is 0; when the oil pressure collected by the pressure sensor is within the set threshold range, the signal value collected by the signal collector is 1.

[0014] According to a second aspect of the embodiments of this application, a control method for a variable compression ratio hydraulic device is also provided, comprising the following steps: The hydraulic module and control module are activated, and the signal collector collects signal values ​​from different pressure sensors; The controller in the control module outputs control signals to different directional valves in the hydraulic module. The directional valves control the hydraulic oil to enter different actuating cylinders. The actuating cylinders drive the first clamping plate and the second clamping plate to move. The controller controls the solenoid directional valve and the relief valve to be in the corresponding positions, and controls the hydraulic oil to enter the low-pressure oil chamber or the high-pressure oil chamber, so that the engine is in different compression ratio states and works.

[0015] The beneficial technical effects of the technical solution provided in this application include: changing the structure of different modules in the hydraulic device and setting a double-acting hydraulic oil chamber at the piston rod, thereby changing the working volume of the cylinder by hydraulically driving the extension and retraction of the piston rod, realizing the variable adjustment of the engine compression ratio, meeting the pressure adjustment requirements of the engine under partial load, and improving fuel economy; at the same time, it can be used in multi-fuel mixed combustion engines to realize multi-stage compression ratio distribution of different fuels, replacing a single fixed geometric compression ratio, ensuring complete combustion of multiple fuels, reducing cylinder knocking, and effectively improving the overall performance of the variable compression ratio hydraulic device.

[0016] The hydraulic oil chamber is equipped with multiple self-locking mechanisms. When hydraulic oil is flowing through the chamber, the ball joint connecting rod of the self-locking structure is subjected to oil pressure, and the ball joint connecting rod and the slider are in an unlocked state. When hydraulic oil is not flowing through the chamber, the ball joint connecting rod of the self-locking structure is not subjected to oil pressure and extends under the action of the elastic element. The ball joint connecting rod is locked in the locking groove of the slider, and the slider is in a self-locking state. This effectively solves the problems of piston rod falling off when the engine starts and piston rod moving erratically when the hydraulic system fails due to loss of pressure in the oil chamber.

[0017] Based on the fact that the piston rod needs to overcome the thrust generated by fuel combustion during its upward movement, resulting in a force required for the piston rod to rise much greater than that required for its downward movement, a two-stage high- and low-pressure oil chamber is adopted to solve the problem of hydraulic energy consumption. At the same time, an energy recovery circuit is set up between the high- and low-pressure oil circuits, allowing the oil in the high-pressure oil chamber to flow back into the low-pressure oil chamber, thus recycling the high-pressure oil and further reducing the working energy consumption of the hydraulic system.

[0018] A clamping and locking mechanism is adopted, which is installed at the piston rod. The first and second clamping plates are hydraulically driven and engage with each other in the groove provided on the piston rod, so that the piston rod is at a fixed geometric compression ratio length. The retaining ring is provided with at least one ball-head plunger. When the first and second clamping plates are closed, the ball-head plunger is located in the locking socket provided on the first and second clamping plates, so as to ensure that the first and second clamping plates remain in a clamping and self-locking state in the event of a hydraulic system failure. This prevents the piston rod from moving up and down erratically, which would aggravate piston wear and knocking, and thus effectively ensures that the engine does not stop.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a partial structural diagram of a variable compression ratio hydraulic device for a marine low-speed engine provided in an embodiment of this application. Figure 2 Provided in the embodiments of this application Figure 1 The axonometric view in the middle; Figure 3 This is a schematic diagram of the variable compression ratio hydraulic device provided in the embodiments of this application; Figures 4-5 This is a schematic diagram of another part of the hydraulic device provided in the embodiments of this application; Figures 6-7 This is a schematic diagram of the clamping and locking structure provided in the embodiments of this application; Figure 8 This is a circuit diagram corresponding to the hydraulic device provided in the embodiments of this application. Detailed Implementation The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0021] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application's specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by this art. It should be understood that when we say an element is “connected” to another element, the element may be directly connected to the other element, or it may mean that the element and the other element are connected through an intermediate element. Furthermore, the term “connected” as used herein may include wireless connections.

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be noted that the following embodiments can be referenced, borrowed, or combined with each other, and the same terms, similar features, and similar implementation steps in different embodiments will not be described again.

[0023] This application provides a variable compression ratio hydraulic device and control method. The variable compression ratio hydraulic device provided in this application is based on an engine performance optimization system.

[0024] Specifically, the variable compression ratio hydraulic device includes: a transmission module 1, a telescopic component 2, a clamping and locking mechanism 3, a control module, and a hydraulic module.

[0025] like Figures 1-3 As shown, Figure 1This is a partial structural diagram of the variable compression ratio hydraulic device for a marine low-speed engine provided in an embodiment of this application. Figure 2 Provided in the embodiments of this application Figure 1 The axonometric view in the middle, Figure 3 This is a schematic diagram of the variable compression ratio hydraulic device provided in the embodiments of this application. Specifically, the telescopic component 2 is disposed within the transmission module 1, and the telescopic component 2 is provided with a self-locking mechanism 21. The self-locking mechanism 21 and the clamping and locking mechanism 4 are used to control the self-locking and unlocking of the telescopic component 2. The hydraulic module is connected to the telescopic component 2 and is used to drive the movement of the telescopic component 2. The control module is used to control the movement of the hydraulic module.

[0026] See details Figure 3 In the transmission module 1, a connecting rod, a pin 12, a cross slider 13, a housing 14, an end cap 15, and a first seal 16 are provided. The connecting rod is movably connected to the pin 12. The housing 14 is provided on the flat surface of the upper end of the pin 12. The first seal 16 is provided in the contact area between the flat surface and the housing 14. The end cap 15 is provided on the upper end surface of the housing. The second seal 17 is provided in the contact area between the upper end surface of the housing 14 and the end cap 15. An inner cavity 18 is provided inside the pin. The inner cavity 18, the housing 14, and the end cap 15 form a sealed hydraulic oil chamber 19. The hydraulic oil chamber 19 is provided with a telescopic component 2. An oil inlet groove 18a is provided at the bottom of the inner cavity 18.

[0027] like Figures 4-5 As shown, Figures 4-5 This is a schematic diagram of another part of the hydraulic device provided in the embodiments of this application. (In conjunction with...) Figures 1-2 The telescopic assembly 2 includes a self-locking mechanism 21, a sliding core 22, a sealing ring 23, and a piston rod 24.

[0028] In this embodiment, the self-locking mechanism 21 consists of a cover 211, a ball joint connecting rod 212, a return spring 213, and a stop post 214. The stop post 214 has a ball joint connecting rod 212 and a return spring 213 on both sides. The ball joint connecting rod 212, the return spring 213, and the stop post 214 are located inside the cover 211. The sliding core 22 consists of a first protrusion 221, a cavity 222, and a second protrusion 223. The first protrusion 221 of the sliding core 22 has a locking groove 22a. The second protrusion 223 of the sliding core 22 has a piston rod 24. A sealing ring 23 is provided at the cavity 222. The sealing ring 23 divides the hydraulic oil chamber 19 into a low-pressure oil chamber 191 and a high-pressure oil chamber 192. The high-pressure oil chamber 192 is fixed with at least one self-locking mechanism 21. The low-pressure oil chamber 191 has a first oil inlet 191a and a first oil outlet 191b.

[0029] In this embodiment, the hydraulic oil chamber is equipped with multiple self-locking mechanisms. When hydraulic oil is flowing through the hydraulic oil chamber, the ball joint connecting rod of the self-locking structure is subjected to oil pressure, and the ball joint connecting rod and the slider are in an unlocked state. When hydraulic oil is not flowing through the hydraulic oil chamber, the ball joint connecting rod of the self-locking structure is not subjected to oil pressure and extends under the action of the elastic element. The ball joint connecting rod is locked in the locking groove of the slider, and the slider is in a self-locking state. This effectively solves the problem of piston rod falling off when the engine starts and the problem of piston rod running around when the hydraulic system fails due to oil chamber pressure loss.

[0030] Specifically, the high-pressure oil chamber 192 is provided with a second oil inlet 192a and a second oil outlet 192b; the upper end of the piston rod 24 is connected to the engine piston, the middle part of the piston rod 24 is provided with a convex ring 241, the convex ring 241 is provided with a groove 242, and a clamping and locking mechanism 3 is provided at the groove 242.

[0031] In this embodiment, a double-acting hydraulic oil chamber is provided at the piston rod. The piston rod is hydraulically driven to extend and retract, thereby changing the working volume of the cylinder and realizing variable adjustment of the engine compression ratio. This meets the pressure adjustment requirements of the engine under partial load and improves fuel economy. At the same time, it can be used in multi-fuel mixed combustion engines to realize multi-stage compression ratio distribution of different fuels, replacing a single fixed geometric compression ratio, ensuring complete combustion of multiple fuels and reducing cylinder knock and other problems.

[0032] Meanwhile, considering that the piston rod needs to overcome the thrust generated by fuel combustion during its upward movement, resulting in a force required for the piston rod to rise much greater than that required for its downward movement, a two-stage high- and low-pressure oil chamber is adopted to solve the problem of hydraulic energy consumption. Furthermore, an energy recovery circuit is set up between the high- and low-pressure oil circuits, allowing oil from the high-pressure oil chamber to flow back into the low-pressure oil chamber, thus reusing the high-pressure oil and further reducing the operating energy consumption of the hydraulic system.

[0033] Furthermore, such as Figures 6-7 , Figures 6-7 This is a schematic diagram of the clamping and locking structure provided in the embodiments of this application. Figure 6 This is a schematic diagram of the structure after the clamping piece is removed. The clamping and locking mechanism 3 consists of a support base 31, a first guide rail slider group 32, a second guide rail slider group 33, a first clamping piece 34, a second clamping piece 35, a first actuating cylinder 36, a second actuating cylinder 37, a proximity sensor 38, and a sensor bracket 39. The support base 31 is fixed to the end cover 15. The support base 31 is provided with the first guide rail slider group 32 and the second guide rail slider group 33. The first guide rail slider group 32 consists of a first guide rail 321, a first slider 322, and a second slider 323.

[0034] Furthermore, the second guide rail slider group 33 is composed of a second guide rail 331, a third slider 332, and a fourth slider 333. The first slider 322 and the third slider 332 are provided with a first clamping piece 34, and the second slider 323 and the fourth slider 333 are provided with a second clamping piece 35. The first clamping piece 34 and the second clamping piece 35 are provided with a first actuating cylinder 36 and a second actuating cylinder 37. The first actuating cylinder 36 has two fingers fixed to the first end of the first clamping piece 34 and the second clamping piece 35, and the second actuating cylinder 37 has two fingers fixed to the second end of the first clamping piece 34 and the second clamping piece 35. The first actuating cylinder 36 and the second actuating cylinder 37 are normally closed spring-return single-acting finger hydraulic cylinders with the same structural parameters. When the hydraulic pressure is not applied, the fingers are clamped. The first clamping piece 34 and the second clamping piece 35 are provided with concave rings 340, and the outer contours of the concave rings 340 are chamfered.

[0035] In this embodiment, a clamping and locking mechanism is employed. A clamping and locking mechanism is provided at the piston rod, and a first and second clamping plate are hydraulically driven. These two plates cooperate and embed into a groove provided on the piston rod, thereby maintaining the piston rod at a fixed geometric compression ratio length. The retaining ring is provided with at least one ball-head plunger. When the first and second clamping plates close, the ball-head plunger is positioned within a locking socket provided on the first and second clamping plates. This ensures that even in the event of a hydraulic system failure, the first and second clamping plates remain in a clamped and self-locking state, preventing the piston rod from moving erratically and aggravating piston wear and detonation, thus effectively ensuring that the engine does not stop.

[0036] like Figure 8 As shown, Figure 8 This is a circuit diagram corresponding to the hydraulic device provided in the embodiments of this application. Referring to the structures in other accompanying drawings, in the embodiments of this application, the control module includes a signal collector, a processor, a controller, and a signal output device.

[0037] Specifically, the signal collector is used to collect the pressure values ​​in the oil circuit where the first pressure sensor 55, the third pressure sensor 587, the second pressure sensor 58c, and the fourth pressure sensor 596 are located.

[0038] When the oil pressure collected by the pressure sensor is lower than the set threshold, the signal value collected by the signal collector is 0; when the oil pressure collected by the pressure sensor is within the set threshold, the signal value collected by the signal collector is 1. The processor processes the signal collected by the algorithm signal collector, converts it into a current signal, and sends it to the controller. The signal is then transmitted to each solenoid valve through the signal output device to control the movement of the valve. See details Figure 6The hydraulic module includes an oil tank 51, a filter 52, a hydraulic pump 53, a first relief valve 54, a first pressure sensor 55, an accumulator 56, a flow divider 57, a telescopic circuit 58, and a clamping circuit 59. The oil tank 51 is connected to the filter 52 and the first relief valve 54. The hydraulic pump 53 is provided at the outlet of the filter 52. The hydraulic pump 53 is connected to the first relief valve 54, the first pressure sensor 55, the flow divider 57, the telescopic circuit 58, and the clamping circuit 59 at its oil pressure output port.

[0039] Meanwhile, an accumulator 56 is provided at the oil inlet of the distributor 57, and multiple telescopic circuits 58 are provided at the oil distribution port of the distributor 57. Each telescopic circuit 58 includes a solenoid directional valve 581, a first proportional valve 58a, a first check valve 58b, a second pressure sensor 58c, a first throttle valve 58d, a first temperature sensor 58e, a first relief valve 58f, a flow accumulator 582, a second throttle valve 583, a second check valve 584, a second temperature sensor 585, a second relief valve 586, a third pressure sensor 587, a two-position directional valve 588, and a third check valve. Valve 589; The electromagnetic directional valve 581 is provided with a left working position, a middle working position and a right working position. The left working position of the electromagnetic directional valve 581 is provided with a first proportional valve 58a. The oil outlet of the first proportional valve 58a is provided with a first check valve 58b, a first pressure sensor 55 and a first throttle valve 58d in sequence. The first throttle valve 58d is provided with a first oil inlet 191a in the low-pressure oil chamber 191. The first oil outlet 191b in the low-pressure oil chamber 191 is provided with a first temperature sensor 58e and a first relief valve 58f in sequence. The first relief valve 58f is connected to the oil tank 51.

[0040] Correspondingly, the right position of the electromagnetic directional valve 581 is sequentially equipped with a flow accumulator 582, a second throttle valve 583, a second check valve 584, and a third pressure sensor 587. The oil outlet of the second check valve 584 is connected to the second oil inlet 192a of the high-pressure oil chamber 192. The second oil outlet 192b of the high-pressure oil chamber 192 is sequentially connected to a second temperature sensor 585 and a second relief valve 586. A two-position directional valve 588 is provided at the oil outlet of the second relief valve 586. The oil outlet of the two-position directional valve 588 at the left position is connected to the oil tank 51. The oil outlet of the right position is connected to the third check valve 589. The oil outlet of the third check valve 589 is connected in parallel to the oil outlet of the left position of the electromagnetic directional valve 581.

[0041] In this embodiment, the clamping circuit 59 includes a second proportional valve 591, a second directional valve 592, a third directional valve 593, and a fourth pressure sensor 596. The second directional valve 592 is connected to the oil inlet of the first actuating cylinder 36, and the third directional valve 593 is connected to the oil inlet of the second actuating cylinder 37. The second directional valve 592, the fourth pressure sensor 596, and the third directional valve 593 are connected in parallel at the oil outlet of the second proportional valve 591.

[0042] Furthermore, this application embodiment also provides a control method for a hydraulic device with a variable compression ratio, including the following steps: The hydraulic module and control module are activated, and the signal collector collects signal values ​​from different pressure sensors; The controller in the control module outputs control signals to different directional valves in the hydraulic module. The directional valves control the hydraulic oil to enter different actuating cylinders. The actuating cylinders drive the first clamping plate and the second clamping plate to move. The controller controls the solenoid directional valve and the relief valve to be in the corresponding positions, and controls the hydraulic oil to enter the low-pressure oil chamber or the high-pressure oil chamber, so that the engine is in different compression ratio states and works.

[0043] Specifically, when controlling a hydraulic device with a variable compression ratio, the compression ratio of the hydraulic device can be adjusted differently according to the usage requirements.

[0044] In the first control method, the hydraulic device can achieve the maximum compression ratio, see details. Figure 5 At this time, the variable compression ratio device is in the maximum compression ratio state: the hydraulic pump 53 and control module are started. When the signal collector collects the signal values ​​of the four pressure sensors and they are all 1, the controller outputs signals to the second reversing valve 592 and the third reversing valve 593 provided in the clamping circuit 59, controlling the second reversing valve 592 and the third reversing valve 593 to be in the left position. The hydraulic oil enters the first and second acting cylinders. The first and second acting cylinders drive the first and second clamping plates to make a spreading movement away from the piston rod. The controller 43 controls the solenoid reversing valve 581 to be in the left position, the second relief valve 586 to be in the open state, and the first relief valve 58f to be in the closed state. The hydraulic oil enters the low-pressure oil chamber through the first oil inlet. The piston rod moves downward under the action of oil pressure. The high-pressure oil chamber is in a depressurized state. The piston rod is self-locked in the high-pressure oil chamber. At this time, the working volume of the engine is the largest and the engine is in the maximum compression ratio stage.

[0045] Simultaneously, the hydraulic system can be adjusted to maintain its minimum compression ratio. See details. Figure 4At this time, the variable compression ratio device is in the minimum compression ratio state: the hydraulic pump 53 and control module are started. When the signal collector collects the signal values ​​of the four pressure sensors and they are all 1, the controller outputs signals to the second reversing valve 592 and the third reversing valve 593 provided in the clamping circuit 59, controlling the second reversing valve 592 and the third reversing valve 593 to be in the left position. Hydraulic oil enters the first and second acting cylinders. The first and second acting cylinders drive the first and second clamping plates to make a spreading movement away from the piston rod. The controller 43 controls the solenoid reversing valve 581 to be in the right position, the second relief valve 586 to be in the closed state, and the first relief valve 58f to be in the open state. Hydraulic oil enters the high-pressure oil chamber through the second oil inlet. The piston rod moves upward under the action of oil pressure. The first oil chamber is in a depressurized state. The piston rod is self-locked in the low-pressure oil chamber. At this time, the working volume of the engine is the smallest and the engine is in the minimum compression ratio position.

[0046] Furthermore, the hydraulic system can be adjusted to operate at a continuous compression ratio: When the hydraulic pump 53 and control module are activated, and the signal collector collects signals from the four pressure sensors all equal to 1, the control module controls the solenoid directional valve 581 and the two-position directional valve 588 to be in the right position based on the crankshaft angle. Simultaneously, it controls the operation of the first relief valve 58f, achieving continuous compression ratio switching between the maximum and minimum compression ratios of the engine. Thus, a continuous compression ratio operating mode is achieved based on the above control actions.

[0047] Furthermore, the hydraulic device can be adjusted to achieve a geometric compression ratio: when the hydraulic pump 53 and control module are started, and the signal collector collects the signal values ​​of the four pressure sensors, all of which are 1, the control module controls the solenoid directional valve 581 to be in the middle position, the clamping circuit is in the open circuit state, and at the same time, the proximity sensor 38 of the clamping and locking mechanism 3 is powered on to make it work.

[0048] When the proximity sensor 38 detects the protruding ring 241 on the piston rod 24, the control module controls the second reversing valve 592 and the third reversing valve to be in the right position. The first actuating cylinder 36 and the second actuating cylinder 37 are in a depressurized state. Under the action of the return spring in the cylinder body, the first actuating cylinder 36 and the second actuating cylinder 37 make a clamping movement towards the piston rod. A clamping plate 34 and a second clamping plate 35 are locked and embedded in the piston rod 24, which has a groove 242, so that the piston rod is in a geometric compression ratio state.

[0049] In this embodiment of the application, when controlling the hydraulic device, when hydraulic and mechanical failures occur, there is also a corresponding failure mode: the signal collector uses the pressure values ​​displayed by the first pressure sensor 55, the third pressure sensor 587, the second pressure sensor 58c, and the fourth pressure sensor 596. If one or more of the signal values ​​collected by the signal collector are 0, the control module determines that the hydraulic module is faulty, the hydraulic pump 53 stops working, and the control module clamps the first clamping plate 34 and the second clamping plate 35 of the clamping and locking mechanism 3 into the groove 242 of the piston rod 24, so that the piston rod is in a geometric compression ratio state, and the engine is in a geometric compression ratio state mode.

[0050] In this embodiment of the application, when controlling the above-mentioned hydraulic device, the oil pressure P1 in the high-pressure oil chamber is greater than the pressure P exerted by the return spring on the ball joint rod in the self-locking mechanism. 自 .

[0051] Meanwhile, the oil pressure P1 in the high-pressure oil chamber is greater than the oil pressure P2 in the low-pressure oil chamber. A return oil circulation circuit consisting of a two-position reversing valve 588 and a third one-way valve 589 is provided between the high-pressure and low-pressure oil chambers. The piston rod 24 has a convex ring 241 positioned at the engine's geometric compression ratio position.

[0052] Furthermore, in the embodiments of this application, the variable compression ratio hydraulic device and control method provided are applied to marine low-speed engines.

[0053] Optionally, this device can also be applied to other engineering fields, such as low-speed engines for other large mining machinery, all of which are within the scope of protection of this application. The variable compression ratio hydraulic device provided in this application effectively reduces wear within the mechanism and improves the load-bearing capacity and reliability of the device. Simultaneously, while ensuring the output torque of the device, it improves combustion efficiency, effectively enhancing the overall performance of the engine.

[0054] The above description is only a partial implementation of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application, without departing from the technical concept of this application, also fall within the protection scope of the embodiments of this application.

Claims

1. A hydraulic device with a variable compression ratio, characterized in that, include: The transmission module has a hydraulic oil chamber; A telescopic assembly, at least a portion of which is disposed within the hydraulic oil chamber, the telescopic assembly including a sliding core and a piston rod slidable relative to the hydraulic oil chamber, the sliding core having a recessed cavity that divides the hydraulic oil chamber into a low-pressure oil chamber and a high-pressure oil chamber, and the high-pressure oil chamber having a self-locking mechanism; A clamping and locking mechanism engages with the piston rod. The clamping and locking mechanism includes multiple guide rail slider groups, multiple clamping plates, and multiple actuating cylinders. The clamping plates are disposed on the guide rail slider groups, and the actuating cylinders are disposed corresponding to the clamping plates. A hydraulic module is connected to the telescopic assembly; A control module, which is used to control the hydraulic module.

2. The variable compression ratio hydraulic device according to claim 1, characterized in that, The transmission module also includes a pin, a housing, an end cap, a first seal, and a second seal. The pin has an inner cavity, which together with the housing and end cap forms the hydraulic oil chamber. The housing is located at the upper end of the pin. The first seal is located in the area where the pin contacts the housing, and the second seal is located in the area where the end cap contacts the housing.

3. The variable compression ratio hydraulic device according to claim 2, characterized in that, An oil inlet groove is also provided at the bottom of the inner cavity.

4. The variable compression ratio hydraulic device according to claim 1, characterized in that, The self-locking mechanism includes a stop post, and ball joints and a return spring respectively disposed on both sides of the stop post.

5. The variable compression ratio hydraulic device according to claim 1, characterized in that, The sliding core also includes a first protrusion and a second protrusion; The first protrusion is provided with a locking groove, the second protrusion is connected to the piston rod, and the cavity is provided with a sealing ring, which is used to divide the hydraulic oil chamber into the low-pressure oil chamber and the high-pressure oil chamber.

6. The variable compression ratio hydraulic device according to claim 5, characterized in that, The low-pressure oil chamber is provided with a first oil inlet and a first oil outlet; the high-pressure oil chamber is provided with a second oil inlet and a second oil outlet; the upper end of the piston rod is connected to the engine piston, and a convex ring is provided in the middle part of the piston rod. A groove is also provided on the convex ring, and the groove engages with the clamping and locking mechanism.

7. The variable compression ratio hydraulic device according to claim 1, characterized in that, The clamping and locking mechanism also includes a support base, a first guide rail slider group, a second guide rail slider group, a first clamping plate, a second clamping plate, a first actuating cylinder, a second actuating cylinder, a proximity sensor, and a sensor bracket; The support base is disposed on the end cover. The first guide rail slider group and the second guide rail slider group are both disposed on the support base. The first guide rail slider group includes a first guide rail, a first slider, and a second slider. The second guide rail slider group includes a second guide rail, a third slider, and a fourth slider. The first slider and the third slider are provided with a first clamping piece. The second slider and the fourth slider are provided with a second clamping piece. The first clamping piece and the second clamping piece are provided with a first actuating cylinder and a second actuating cylinder. One end of the first actuating cylinder is fixed to the first end of the first clamping piece and the second clamping piece. One end of the second actuating cylinder is fixed to the second end of the first clamping piece and the second clamping piece.

8. The variable compression ratio hydraulic device according to claim 7, characterized in that, Both the first and second actuating cylinders are configured as normally closed spring-reset single-acting finger hydraulic cylinders.

9. The variable compression ratio hydraulic device according to claim 1, characterized in that, The control module includes a signal collector, a processor, a controller, and a signal output device; The signal collector is used to collect the pressure values ​​in the oil circuit where the first pressure sensor, the third pressure sensor, the second pressure sensor, and the fourth pressure sensor are located. The processor converts the signals collected by the signal collector into current signals and sends them to the controller, and transmits them to each solenoid valve through the signal output device. Specifically, when the oil pressure collected by the pressure sensor is lower than a set threshold, the signal value collected by the signal collector is 0; when the oil pressure collected by the pressure sensor is within the set threshold range, the signal value collected by the signal collector is 1.

10. A control method for a variable compression ratio hydraulic device, employing a variable compression ratio hydraulic device as described in any one of claims 1-9, characterized in that, Includes the following steps: The hydraulic module and control module are activated, and the signal collector collects signal values ​​from different pressure sensors; The controller in the control module outputs control signals to different directional valves in the hydraulic module. The directional valves control the hydraulic oil to enter different actuating cylinders. The actuating cylinders drive the first clamping plate and the second clamping plate to move. The controller controls the solenoid directional valve and the relief valve to be in the corresponding positions, and controls the hydraulic oil to enter the low-pressure oil chamber or the high-pressure oil chamber, so that the engine is in different compression ratio states and works.

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