Device and method for applying gas force to engine motion mechanism

Abstract

The present invention provides a device and method for applying gas force to an engine motion mechanism. The device includes: a force transmission piston connected to the engine motion mechanism directly or through a transmission mechanism; a force regulating piston and the force transmission piston simultaneously reciprocating within an oil chamber housing to form a main oil chamber for providing gas force; a piston return spring is provided on the force regulating piston to provide spring force to maintain constant contact between the various transmission components between the force regulating piston and the force regulating cam; the oil storage chamber is connected to the main oil chamber via a dual oil circuit, each of which is provided with a control unit and a safety unit; the target pressure of the main oil chamber is set according to different working conditions, and the gas force applied to the engine motion mechanism is obtained through the coordinated control of the force transmission piston, the force regulating piston, and the control unit and safety unit on the dual oil circuits. The present invention has a simple structure and can achieve the application of gas force to the tested component during the component testing phase, shortening the development cycle and investment.

Description

Technical Field

[0001] The present invention relates to the field of engines, and in particular to a device and method for applying gas force to an engine motion mechanism. Background Art

[0002] The application of new engine technologies significantly impacts the forces acting on the engine's motion mechanisms. For example, in decompression and two-stroke brake mechanisms, the exhaust valves must open near top dead center, resulting in significant forces exerted by the high-pressure compressed gas within the cylinder on the valves, with these forces varying dramatically and complexly. Furthermore, the implementation of various new combustion and high-strength engine technologies results in significant forces exerted by the high-pressure gas within the cylinder on the valve train and connecting rod crankshaft mechanism, with these forces varying dramatically and complexly. At the same time, engine lightweighting technologies require streamlined designs for the valve train and connecting rod crankshaft mechanism, posing a development challenge in ensuring their reliability and longevity. Currently, during early component testing of these mechanisms, gas forces such as in-cylinder pressure cannot be applied to the mechanisms. Consequently, component test results differ significantly from those obtained during engine testing, requiring reliability and other performance verification to be performed on an engine test bench. This results in lengthy component development cycles and significant human and material investment. There is an urgent need to develop testing equipment that can apply gas forces such as in-cylinder pressure to engine motion mechanisms to shorten development cycles and investment. Summary of the Invention

[0003] In response to the aforementioned shortcomings in testing components during the early stages of engine motion mechanism development, a device and method for applying gas force to an engine motion mechanism are provided. The present invention sets a target pressure in the main oil chamber according to different operating conditions. Through the coordination of a force transmission piston, a force adjustment piston, a control unit, and a safety unit on the dual oil circuits, the gas force applied to the engine motion mechanism is generated. This allows for real-time adjustment of the pressure within the control chamber to meet the gas force requirements for the test conditions, completing the test.

[0004] The technical means adopted in the present invention are as follows:

[0005] A device for applying gas force to an engine motion mechanism, characterized by comprising:

[0006] A force transmission piston, at least one of which is connected to the engine movement mechanism directly or through a transmission mechanism;

[0007] At least one force regulating piston is provided, which is driven directly or through a transmission component via a force regulating cam; the force regulating piston and the force transmission piston simultaneously reciprocate within the oil chamber housing, forming a main oil chamber for providing gas force therebetween; a piston return spring is provided on the force regulating piston to provide spring force to maintain constant contact between the force regulating piston and the transmission components between the force regulating cam;

[0008] The oil storage chamber is connected to the main oil chamber through a dual oil circuit, wherein a control unit is provided on the first oil circuit, and the flow direction of the hydraulic oil flowing through the control unit is determined by the pressure difference, and a safety unit is provided on the second oil circuit for draining oil to ensure safety;

[0009] During operation, the target pressure of the main oil chamber is set according to different working conditions, and the gas force applied to the engine movement mechanism is obtained through the cooperation between the force transmission piston, the force regulating piston, and the control unit and the safety unit on the dual oil circuits.

[0010] Furthermore, the engine movement mechanism is a valve mechanism and / or a connecting rod crankshaft mechanism.

[0011] Furthermore, at least one oil source chamber is set in the oil storage chamber. When more than one oil source chamber is set, the first oil circuit has at least two branch oil circuits corresponding to the oil source chamber. Accordingly, the control unit uses a multi-position multi-directional valve or multiple solenoid valves to control the oil circuit to achieve real-time pressure regulation of the main oil chamber.

[0012] Furthermore, the pressure of the oil storage chamber is adjustable, and the difference in target gas force caused by different working conditions can be controlled by adjusting the pressure of the oil storage chamber in coordination with the opening and closing state of the control unit.

[0013] Furthermore, the target pressure of the main oil chamber is determined at least by the pressure in the cylinder, the ambient pressure, the area of the force transmission piston, the volume of the main oil chamber and the hydraulic oil characteristics, as well as parameters related to the engine motion mechanism. The parameters related to the engine motion mechanism vary depending on the engine motion mechanism. Accordingly, when the engine motion mechanism is a valve mechanism, the parameters related to the engine motion mechanism refer to the valve disc area, valve stem area, airway pressure and valve cover chamber pressure; when the engine motion mechanism is a connecting rod crankshaft mechanism, the parameters related to the engine motion mechanism refer to the piston area and crankcase pressure.

[0014] Furthermore, the profile of the force regulating cam is designed based on the target pressure of the main oil chamber, the area of the force transmitting piston, the area of the force regulating piston and the stroke curve of the force transmitting piston determined by the engine motion mechanism;

[0015] When the target force adjustment cam meets the strength requirements, the target force adjustment cam is used as the actual force adjustment cam:

[0016] When the target force-adjusting cam does not meet the strength requirement, a cam that meets the strength requirement and is close to the target force-adjusting cam profile is adopted as the actual force-adjusting cam.

[0017] The present invention also provides a method for using the above-mentioned device for applying gas force to an engine motion mechanism, which is characterized by comprising the following steps:

[0018] The target pressure of the main oil chamber is set according to the working conditions, and the device is started, so that the force regulating piston and the force transmitting piston simultaneously reciprocate in the oil chamber housing to form a preset real-time pressure in the main oil chamber;

[0019] Compare the target pressure and the real-time pressure. If they are within the preset safety pressure range,

[0020] When the real-time pressure is equal to the target pressure, keeping the control unit closed;

[0021] When the real-time pressure is not equal to the target pressure, the real-time pressure in the main oil chamber is adjusted in real time by a control unit on a dual oil circuit connected to the main oil chamber so as to be equal to the target pressure;

[0022] When the preset safety pressure is exceeded, the safety unit automatically and quickly releases the pressure.

[0023] Furthermore, when the real-time pressure is not equal to the target pressure, adjustments should also be made to the situation where the target force adjustment cam does not meet the strength requirements, and to the situation where small changes in the gas force and / or the movement law of the engine movement mechanism caused by changes in working conditions.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The device provided by the present invention serves as a component for simplifying the simulation of movement in an engine cylinder. While each component meets the design standards, it accurately captures pressure changes and responds in a timely manner.

[0026] Specifically, the present invention rationalizes and improves existing methods of applying gas force. Because actual engine cylinder pressure and other values are extremely large and vary dramatically and complexly, the gas force acting on moving parts is also extremely large and varies correspondingly dramatically and complexly. Therefore, existing methods of applying gas force to moving parts using a cam plus a spring, relying solely on the cam to simulate realistic gas force, require the cam to have multiple lobes, each with extremely steep ascending and descending sections. Furthermore, the cam follower must be prevented from flying off, and the strength of each component must meet the required requirements. However, cam design often struggles to meet these requirements.

[0027] This invention utilizes a force-transmitting piston and a force-regulating piston for hydraulic amplification, and in conjunction with a control unit, reduces the requirements for the force-regulating cam's rising speed during its ascending section and its descending speed during its descending section. The control unit also simulates multiple variations in applied gas force, reducing the number of cam bumps. This reduces the design complexity of the force-regulating cam, making it easier to obtain a force-regulating cam profile that meets design requirements such as strength, adapts to extreme operating conditions, and applies a force to the moving parts that closely approximates actual gas force.

[0028] The device provided by the present invention can adjust the pressure in the main oil chamber in accordance with the setting of different working conditions by only coordinating the control unit and the safety unit without changing the hardware conditions of each component, thereby obtaining the gas force applied to the engine movement mechanism.

[0029] Based on the above reasons, the present invention can be widely promoted in the test stage of the engine movement mechanism which requires the application of gas force. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 This is a structural schematic diagram of the device of the present invention for testing the valve mechanism.

[0032] Figure 2 This is a structural schematic diagram of the device of the present invention for testing a connecting rod crankshaft mechanism.

[0033] Figure 3 Figure 1 is a schematic diagram of the design principle of the force regulating cam profile under the two-stroke braking condition of the present invention, wherein (a) is a schematic diagram of the exhaust valve lift curve during the two-stroke braking process of the engine; (b) is a schematic diagram of the gas force curve during the corresponding two-stroke braking process; and (c) is a schematic diagram of the contour line of the force regulating cam.

[0034] Figure 4 The following is a schematic diagram of the design principle of the force regulating cam profile under the decompression braking condition of the present invention, wherein (a) is a schematic diagram of the decompression braking exhaust valve lift curve; (b) is a schematic diagram of the contour line of the force regulating cam.

[0035] Figure 5 This is a schematic diagram of the design principle of the force-adjusting cam profile in the connecting rod crankshaft mechanism drive mode of the present invention, where (a) is a schematic diagram of the piston lift curve; (b) is a schematic diagram of the cylinder pressure curve under the corresponding drive mode; and (c) is a schematic diagram of the contour line of the force-adjusting cam.

[0036] In the figure: 1. Transmission mechanism; 2. Force transmission piston; 3. Main oil chamber; 4. Force regulating piston; 5. Force regulating cam; 6. Oil storage chamber; 7. Safety unit; 8. Control unit; 9. Piston return spring; 10. Valve mechanism; 11. Connecting rod crankshaft mechanism. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0040] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0041] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0042] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0043] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0044] like Figure 1 、 Figure 2 As shown, the present invention provides a device for applying gas force to an engine moving mechanism, wherein the engine moving mechanism is a valve train and / or a connecting rod crankshaft mechanism. The gas force may include in-cylinder pressure, airway pressure, valve cover chamber pressure, crankcase pressure, etc. The type of gas force and calculation formula vary depending on the engine moving mechanism being tested.

[0045] The device of the present invention comprises:

[0046] At least one force transmission piston 2 is provided, which is connected to the engine motion mechanism directly or through a transmission mechanism. For example, if the valve train 10 and the connecting rod crankshaft mechanism 11 are measured together, two force transmission pistons 2 are required. Alternatively, if the valve train 10 has two valves, at least two force transmission pistons 2 are also required. The force transmission piston 2 can be part of the engine motion mechanism, or it can be directly pushed by the engine motion mechanism or pushed through a common transmission mechanism such as a rocker arm. Figure 1 As shown, the valve mechanism 10 pushes the power transmission piston 2 through the transmission mechanism 1; Figure 2 As shown, the engine piston is equivalently designed as a power transmission piston 2.

[0047] At least one force regulating piston 4 is provided. For situations where the pressure in the cylinder changes drastically or complexly, multiple force regulating pistons 4 and a force regulating cam 5 can be used together to provide gas force. After being driven directly by the force regulating cam 5 or through a transmission component, the force regulating piston 4 and the force transmission piston 2 simultaneously reciprocate in the oil chamber housing, forming a main oil chamber 3 for providing gas force therebetween; a piston return spring 9 is provided on the force regulating piston 4 to provide a spring force to keep the various transmission components between the force regulating piston 4 and the force regulating cam 5 in constant contact; the arrangement of the piston return spring 9 is conventional and can be arranged inside or outside the main oil chamber housing; the profile of the force regulating cam 5 is designed based on the target pressure of the main oil chamber 3, the area of the force transmission piston, the area of the force regulating piston, and the stroke curve of the force transmission piston determined by the engine movement mechanism;

[0048] When the target force adjustment cam meets the strength requirements, the target force adjustment cam is used as the actual force adjustment cam:

[0049] When the target force-adjusting cam does not meet the strength requirement, a cam that meets the strength requirement and is close to the target force-adjusting cam profile is adopted as the actual force-adjusting cam.

[0050] The oil storage chamber 6 is connected to the main oil chamber 5 through a dual oil circuit. A control unit 8 is provided on the first oil circuit. The control unit 8 has at least one control valve. The control valve is adjusted in real time. The flow direction of the hydraulic oil flowing through the control unit 8 is determined by the pressure difference. A safety unit 7 is provided on the second oil circuit for oil leakage to ensure safety. The safety unit 7 has at least one safety valve. The safety valve only quickly releases pressure when the pressure exceeds a preset safety pressure. The preset safety pressure value can be modified under different working conditions to adjust the actual pressure of the main oil chamber 3 to always be within a safe range.

[0051] At least one oil source chamber is set in the oil storage chamber 6. The control unit 8 can be set as an inlet and outlet pressure regulating valve, such as a pressure relief valve, which can drain oil and supply oil to the main oil chamber. This is determined by the pressure difference between the main oil chamber 3 and the oil storage chamber 6.

[0052] When more than one oil source cavity is set in the oil storage cavity 6, such as a high-pressure oil source and a low-pressure oil source; the first oil circuit has at least two branch oil circuits corresponding to the oil source cavity. Accordingly, the control unit 8 uses a multi-position multi-directional valve or multiple solenoid valves to control the oil circuit, such as a two-position three-way valve, a three-position three-way valve, two two-position two-way valves, a combination of two two-position two-way valves and a one-way valve, etc. to achieve the adjustment of the target pressure of the main oil cavity.

[0053] The safety unit 7 may be a safety valve that allows inlet but not outlet, and is mainly used to quickly release the surged pressure in the cavity and control the pressure of the entire device within a safe range.

[0054] During operation, the target pressure of the main oil chamber 3 is set according to different working conditions, and the gas force applied to the engine movement mechanism is obtained through the coordinated control of the force transmission piston 2, the force regulating piston 4 and the control valves on the dual oil circuits.

[0055] The target pressure of the main oil chamber 4 is determined by at least the in-cylinder pressure, ambient pressure, the area of the force-transmitting piston, the volume of the main oil chamber, hydraulic oil properties, and parameters related to the engine's motion mechanism. These parameters vary depending on the engine's motion mechanism. For a valve train, these parameters include valve disc area, valve stem area, airway pressure, and valve cover chamber pressure. For a connecting rod-crankshaft mechanism, these parameters include piston area and crankcase pressure. When a valve train and connecting rod-crankshaft mechanism are used together, the pressure-influencing factors are compounded.

[0056] The gas force is equal to the target pressure of the main oil chamber 3 that the power transmission piston 2 should be subjected to, that is, the product of the target pressure of the main oil chamber 3 and the area of the power transmission piston 2 .

[0057] The present invention also provides a method for using the above-mentioned device for applying gas force to an engine motion mechanism, comprising the following steps:

[0058] The target pressure of the main oil chamber 3 is set according to the working conditions, and the device is started. The force regulating piston 4 and the force transmitting piston 2 simultaneously reciprocate in the oil chamber housing to form a preset real-time pressure in the main oil chamber 3;

[0059] Compare the target pressure and the real-time pressure. If they are within the preset safety pressure range,

[0060] When the real-time pressure is equal to the target pressure, keeping the control unit 8 closed;

[0061] When the real-time pressure is not equal to the target pressure, the real-time pressure in the main oil chamber 3 is adjusted in real time by the control unit 8 on the dual oil circuit connected to the main oil chamber 3 so as to be equal to the target pressure;

[0062] When the preset safety pressure is exceeded, the safety unit 7 automatically and quickly releases the pressure.

[0063] When the real-time pressure is not equal to the target pressure, it should also include adjustments for situations where the target force-adjusting cam does not meet the strength requirements, and adjustments for small changes in the gas force and / or the motion law of the engine motion mechanism caused by changes in working conditions.

[0064] Example 1

[0065] like Figure 3 As shown, Figure 3 (a) shows the exhaust valve lift curve during two-stroke braking. Within a four-stroke engine cycle, two-stroke braking involves two braking cycles. When the engine reaches compression top dead center (CTDC), the exhaust valve opens with a small lift, venting high-pressure gas from the cylinder. When the piston reaches bottom dead center, the exhaust valve opens again with a larger lift, allowing more gas to enter the cylinder and increasing engine braking power. Figure 3 (b) shows the corresponding gas force curve during two-stroke braking, obtained through simulation analysis or experiments. When the engine is at top dead center (TDC), the in-cylinder pressure is high, and the gas force significantly affects the force applied to the valve train. Figure 3 (c) is a schematic diagram of the outline of the force regulating cam 5 under this working condition. The force regulating cam 5 rotates synchronously with the camshaft of the valve mechanism. By rationally designing the force regulating cam 5 profile and controlling the opening and closing states of the control unit 8, the pressure in the main oil chamber 3 is adjusted to the same value as the pressure in the main oil chamber 3. Figure 3 The gas force curve of (b) is consistent.

[0066] Example 2

[0067] like Figure 4 As shown, Figure 4 (a) shows the exhaust valve lift curve for decompression braking. During a four-stroke engine cycle, decompression braking performs negative work only once. When the piston reaches compression top dead center (CTDC), the exhaust valve opens with a small lift, venting the high-pressure gas in the cylinder. The exhaust valve then opens normally during the subsequent exhaust stroke. Unlike two-stroke braking, significant changes in cylinder pressure during decompression braking occur only near compression top dead center within a four-stroke cycle. Figure 4 (b) shows the contour of force cam 5 during decompression braking. Force cam 5 rotates synchronously with the valve train camshaft. Similarly, the gas force curve during decompression braking is obtained through simulation analysis or experimentation. By properly designing the contour of force cam 5 and controlling the opening and closing states of control unit 8, the pressure in main oil chamber 3 is aligned with the gas force curve during decompression braking.

[0068] Example 3

[0069] like Figure 5 As shown, Figure 5 (a) is a schematic diagram of the piston lift curve. In one engine cycle, the engine piston reciprocates twice. Figure 5 (b) is a schematic diagram of the in-cylinder pressure curve obtained through measurement or simulation analysis. To test the connecting rod crankshaft mechanism, the force transmission piston 2 is connected to the engine connecting rod to obtain the actual piston lift. By rationally designing the profile of the force adjustment cam 5 and controlling the opening and closing states of the control unit 8, the pressure in the main oil chamber 3 is aligned with the cylinder pressure curve. Figure 5 (c) shows the contour line of the designed force-adjusting cam 5.

[0070] Depend on Figure 3 (b) It can be seen that when the engine is near the top dead center (intake and exhaust top dead center or compression top dead center), the pressure in the cylinder increases rapidly and then decreases rapidly. Figure 5 (b) It can be seen that when the engine is near the compression top dead center, the pressure in the cylinder increases rapidly and then decreases rapidly. In order to make the pressure in the main oil chamber 3 achieve the effect of rapid increase and then rapid decrease required in these situations, if only relying on the force regulating cam 5, the contour line of the force regulating cam 5 will rise with a great acceleration and then fall with a great acceleration, which can easily cause the various transmission components between the force regulating cam 5 and the force regulating piston 4 to be subjected to great force, or even fly off, and the design of the force regulating cam 5 is extremely difficult. In order to reduce the design difficulty of the force regulating cam 5, the force transmission piston and the force regulating piston are used for hydraulic amplification to reduce the requirements for the rising speed of the rising section and the falling speed of the falling section of the force regulating cam. When the hydraulic amplification is performed, the design of the force regulating cam still cannot meet the requirements of strength and the like. It is also possible to control the opening and closing state of the control unit 8 so that part of the hydraulic oil in the main oil chamber 3 flows in or out through the control unit 8, so that the pressure in the main oil chamber 3 can achieve the purpose of rapid increase or decrease. Therefore, under the joint action of the control unit 8 and the force regulating cam 5, the pressure of the main oil chamber 3 and Figure 3 (b) Figure 5 (b) and the required gas force curve.

[0071] In addition to controlling the opening and closing states of the control unit 8 to meet the target gas force when the force adjustment cam fails to meet the strength requirements, as described above, the opening and closing states of the control unit 8 can also be used to achieve consistency between the real-time gas force and the target gas force, even in the case of minor changes in the gas force and / or the motion pattern of the engine's motion mechanism due to varying operating conditions, in order to minimize changes to the hardware structure of the various components of the present device. For example, the gas force exerted on the motion mechanism and / or the motion pattern of the motion mechanism vary slightly under different engine operating conditions. Therefore, the force adjustment cam can be shaped to meet the maximum gas force requirement, and the hydraulic oil in the main oil chamber 3 can be depressurized by controlling the opening and closing states of the control unit 8 to ensure that the gas force under other operating conditions meets the corresponding requirements. If controlling the control unit 8 alone still fails to meet the gas force requirements under other operating conditions, other methods can be used, such as adjusting the pressure of the oil reservoir, using multiple oil sources with different pressures and corresponding control units, to cooperate with the control unit 8 to achieve the desired gas force under different operating conditions. For example, increasing the pressure of the oil reservoir can achieve a higher overall gas force. By setting up two oil sources with different pressures, different oil inlet / outlet speeds of the main oil chamber can be obtained by controlling the connection state of the two oil sources with the main oil chamber, thereby obtaining different gas force changes.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for applying gas force to an engine motion mechanism, characterized in that: It is suitable for testing components in the early stages of engine motion mechanism development. The target pressure of the main oil chamber is set according to different working conditions. The gas force applied to the engine motion mechanism is obtained through the cooperation of the force transmission piston, the force adjustment piston, the control unit and the safety unit on the dual oil circuit, thereby playing a role in real-time adjustment of the pressure in the control chamber to meet the gas force required by the test conditions. include: A force transmission piston, at least one of which is connected to the engine movement mechanism directly or through a transmission mechanism; At least one force regulating piston is provided, which is driven directly or through a transmission component via a force regulating cam; the force regulating piston and the force transmission piston simultaneously reciprocate within the oil chamber housing, forming a main oil chamber for providing gas force therebetween; a piston return spring is provided on the force regulating piston to provide spring force to maintain constant contact between the force regulating piston and the transmission components between the force regulating cam; The oil storage chamber is connected to the main oil chamber through a dual oil circuit, wherein a control unit is provided on the first oil circuit, and the flow direction of the hydraulic oil flowing through the control unit is determined by the pressure difference; a safety unit is provided on the second oil circuit for draining oil to ensure safety, and the actual pressure of the main oil chamber is always adjusted to be within a safe range; During operation, the target pressure of the main oil chamber is set according to different working conditions, and the gas force applied to the engine movement mechanism is obtained through the cooperation between the force transmission piston, the force regulating piston, and the control unit and the safety unit on the dual oil circuits; The profile of the force regulating cam is designed according to the target pressure of the main oil chamber, the area of the force transmitting piston, the area of the force regulating piston and the stroke curve of the force transmitting piston determined by the engine movement mechanism; The target pressure of the main oil chamber is determined by at least the pressure in the cylinder, the ambient pressure, the area of the force transmission piston, the volume of the main oil chamber, the hydraulic oil characteristics, and parameters related to the engine motion mechanism. The parameters related to the engine motion mechanism vary depending on the engine motion mechanism. Accordingly, when the engine motion mechanism is a valve train, the parameters related to the engine motion mechanism refer to the valve disc area, the valve stem area, the airway pressure, and the valve cover chamber pressure; when the engine motion mechanism is a connecting rod crankshaft mechanism, the parameters related to the engine motion mechanism refer to the piston area and the crankcase pressure. The specific usage method includes the following steps: The target pressure of the main oil chamber is set according to the working conditions, and the device is started, and the force regulating piston and the force transmitting piston simultaneously reciprocate in the oil chamber housing to form a preset real-time pressure in the main oil chamber; The target pressure and the real-time pressure are compared. If they are within the preset safety pressure range, When the real-time pressure is equal to the target pressure, keeping the control unit closed; When the real-time pressure is not equal to the target pressure, the real-time pressure in the main oil chamber is adjusted in real time by a control unit on a dual oil circuit connected to the main oil chamber so as to be equal to the target pressure; When the preset safety pressure is exceeded, the safety unit automatically and quickly releases the pressure.

2. The device for applying gas force to an engine motion mechanism according to claim 1, characterized in that: The engine movement mechanism is a valve mechanism and / or a connecting rod crankshaft mechanism.

3. The device for applying gas force to an engine motion mechanism according to claim 1, characterized in that: At least one oil source chamber is set in the oil storage chamber. When more than one oil source chamber is set, the first oil circuit has at least two branch oil circuits corresponding to the oil source chamber. Accordingly, the control unit uses a multi-position multi-directional valve or multiple solenoid valves to control the oil circuit to achieve real-time pressure regulation of the main oil chamber.

4. The device for applying gas force to an engine motion mechanism according to claim 3, characterized in that: The pressure of the oil storage chamber is adjustable, and the difference in target gas force caused by different working conditions can be controlled by adjusting the pressure of the oil storage chamber in conjunction with the opening and closing state of the control unit.

5. The device for applying gas force to an engine motion mechanism according to claim 1, characterized in that: When the target force adjustment cam meets the strength requirements, the target force adjustment cam is used as the actual force adjustment cam: When the target force-adjusting cam does not meet the strength requirement, a cam that meets the strength requirement and is close to the target force-adjusting cam profile is adopted as the actual force-adjusting cam.

6. The device for applying gas force to an engine motion mechanism according to claim 1, characterized in that: When the real-time pressure is not equal to the target pressure, it should also include adjustments for situations where the target force-adjusting cam does not meet strength requirements, and adjustments for changes in gas force and / or engine motion mechanism motion laws caused by changes in working conditions.

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