Flexible cavity variable damping structure for reducing pressure impact of discrete digital brake valve

Abstract

The invention belongs to the technical field of brake systems of aviation aircrafts, and particularly relates to a flexible cavity variable damping structure for reducing pressure impact of a discrete digital brake valve, which comprises a pipe joint body, a sealing stopper and a limiting sleeve fixed in the pipe joint body, and a rotor movably arranged between the sealing stopper and the limiting sleeve, a first oil passing hole and a pressure passing hole are formed in the rotor; a second oil passing hole and a communicating hole are formed in the sealing stopper; a reset cavity is formed between the sealing blocking piece and the rotor, the pressure through hole and the communicating hole are both communicated with the reset cavity, an overflow piece matched with the second oil passing hole is further movably arranged in the pipe connector, the first end of the pipe connector body is connected with a brake valve through a hose, and the second end of the pipe connector body is connected with a brake cavity through a hard pipe. By means of the structural arrangement of the damping assembly in the pipe connector body, damping self-adaptive adjustment can be achieved according to the differential pressure of the two sides, the phenomenon of brake pressure overshoot caused by pressure impact is reduced, and then the possibility that an airplane wheel is locked due to brake overshoot is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of the braking system of aircraft, and particularly relates to a flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve. Background Art

[0002] As the core control unit for the safe takeoff and landing of an aircraft, the pressure control accuracy and dynamic response performance of the aircraft braking system are directly related to the braking efficiency and the safety of the airframe. Conventional aircraft braking systems generally use a pressure servo valve as the core component for pressure regulation, and achieve pressure control by adjusting the opening degree of the valve core. However, this technology has significant defects: firstly, the precision throttling structure inside the pressure servo valve is extremely sensitive to hydraulic oil pollution, and micron-sized particles can cause the valve core to get stuck, resulting in a significant reduction in reliability under long-term service conditions; secondly, this type of valve body requires a complex feedback control loop, resulting in problems such as high system complexity and high maintenance costs.

[0003] In recent years, in the field of digital hydraulic technology, a discrete digital brake valve composed of a high-speed discrete digital brake valve array to form a hydraulic bridge has been proposed. The pressure rise and fall of the brake pressure chamber are controlled by controlling the on-off time of the discrete digital brake valves before and after the hydraulic bridge, and the precise control of the brake pressure is achieved by utilizing the fast response characteristics of the high-speed discrete digital brake valve. However, the mechanical structure response of the discrete digital brake valve cannot achieve the effect of linear control, and the mechanical structure of the high-speed discrete digital brake valve cannot immediately respond to the change of the control signal either. When the discrete digital brake valve receives the closing signal, the pressure in the control chamber is still changing, and the continuous rise of the brake pressure will cause the phenomenon of overshoot of the control pressure.

[0004] Therefore, there is an urgent need to develop a variable damping structure applied to the discrete digital brake valve to reduce the overshoot of the brake pressure caused by the untimely closing of the discrete digital brake valve, so as to meet the strict technical requirements of the aircraft for the braking system of "high reliability and fast response". Summary of the Invention

[0005] In order to solve the problems in the above background art, the present invention provides a flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve. The flexible cavity variable damping structure is installed between the output port of the brake valve and the brake pressure control chamber, and can achieve adaptive damping adjustment, thereby reducing the phenomenon of overshoot of the brake pressure caused by the untimely closing of the discrete digital brake valve.

[0006] The technical solution of the present invention is as follows:

[0007] A flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve, comprising a pipe joint body and a hose. The pipe joint body has a first end and a second end. The hose is installed on the first end and is used to connect the brake valve, and the second end is used to connect the brake cavity. A damping component is installed in the pipe joint body;

[0008] The damping component includes a sealing stopper and a limiting sleeve that are axially spaced and fixed in the pipe joint body, and a mover that is axially movable and disposed between the sealing stopper and the limiting sleeve. The limiting sleeve is close to the first end, and the sealing stopper is close to the second end; a first oil passage hole is provided on the mover, and a second oil passage hole is provided on the sealing stopper; when the mover contacts the sealing stopper, the first oil passage hole communicates with the second oil passage hole, and a reset cavity is formed between the sealing stopper and the mover. A communication hole and a pressure passage hole are provided on the side wall of the reset cavity. The communication hole and the second oil passage hole communicate with the brake cavity, and the pressure passage hole and the first oil passage hole communicate with the hose;

[0009] An overflow member is also movably provided in the sealing stopper, and the overflow member can block or move away from the second oil passage hole; when the pressure at the first end is equal to the pressure at the second end, the mover moves away from the sealing stopper, and the overflow member blocks the second oil passage hole; when the pressure at the first end is greater than the pressure at the second end, the mover moves to contact the sealing stopper, and when the pressure difference between the first end and the second end is less than a preset pressure difference, the overflow member blocks the second oil passage hole, and when the pressure difference between the first end and the second end is greater than the preset pressure difference, the overflow member moves away from the second oil passage hole.

[0010] Further, there is at least one communication hole provided on the sealing stopper, and at least one pressure passage hole provided on the mover, and the diameter of the communication hole is greater than the diameter of the pressure passage hole.

[0011] Further, an installation hole section is formed in the pipe joint body, the damping component is disposed in the installation hole section, and a limiting portion is provided on one side of the installation hole section close to the second end;

[0012] A first elastic member is provided between the overflow member and the limiting portion. When the pressure difference between the first end and the second end is less than the preset pressure difference, the first elastic member pushes the overflow member to block the second oil passage hole.

[0013] Further, a second elastic member is provided between the sealing stopper and the mover, and the second elastic member can push the mover to move between the sealing stopper and the limiting sleeve;

[0014] When the pressure at the first end is the same as the pressure at the second end, the mover is in an initial steady state and contacts the limiting sleeve. A gap is formed between the mover and the sealing stopper, and the oil fluid enters the reset cavity from the gap after passing through the first oil passage hole and flows out through the communication hole;

[0015] When the pressure difference between the first end and the second end is less than the preset pressure difference, the hydraulic oil enters the reset cavity from the pressure - through hole, reducing the pressure difference between both ends of the pipe joint body, and the second elastic member pushes the mover to reset to the initial steady state;

[0016] When the pressure difference between the first end and the second end is greater than the preset pressure difference, the hydraulic oil enters the second oil - through hole from the first oil - through hole and flows out. A part of the flowing - out hydraulic oil enters the reset cavity from the communication hole, reducing the pressure difference between both ends of the pipe joint body, and pushing the mover to reset to the initial steady state through the second elastic member.

[0017] Further, the overflow member is of a top - cone structure. The overflow member includes a conical member that cooperates with the second oil - through hole and a guiding column fixed to the large - diameter end of the conical member. One end of the first elastic member abuts against the limiting portion, and the other end is sleeved on the outer periphery of the guiding column.

[0018] Further, the outer peripheral surface of the large - diameter end of the conical member is configured to have at least two symmetrically arranged planes, and an oil - through channel is formed between the plane and the inner cavity of the sealing stopper.

[0019] Further, the pre - tightening force of the first elastic member is greater than the pre - tightening force of the second elastic member.

[0020] Further, the sealing stopper includes coaxially arranged first and second cylindrical portions. The first cylindrical portion is connected to the second cylindrical portion. The outer diameter of the first cylindrical portion is the same as the inner diameter of the installation hole section. The outer diameter of the second cylindrical portion is smaller than the outer diameter of the first cylindrical portion. The second oil - through hole is opened on the second cylindrical portion, and the communication hole is opened on the outer periphery of the second oil - through hole.

[0021] Further, the mover includes coaxially arranged third and fourth cylindrical portions. The third cylindrical portion is connected to the fourth cylindrical portion. The outer diameter of the third cylindrical portion is the same as the inner diameter of the installation hole section. The outer diameter of the fourth cylindrical portion is smaller than the outer diameter of the third cylindrical portion. The first oil - through hole is opened on the fourth cylindrical portion, and the pressure - through hole is opened on the outer periphery of the first oil - through hole.

[0022] Further, the sealing stopper is fixed in the pipe joint body by interference fit with the pipe joint body, and the limiting sleeve is fixedly welded to the pipe joint body.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The flexible cavity variable damping structure of the present invention comprises a pipe joint body and a damping assembly installed in the pipe joint body, the damping assembly comprising a sealing stopper and a limit sleeve axially fixed in the pipe joint body, and an axially movable mover arranged between the sealing stopper and the limit sleeve, the mover is provided with a first oil through hole and a pressure through hole, and the sealing stopper is provided with a second oil through hole and a connecting hole; a reset chamber is formed between the sealing stopper and the mover, the pressure through hole and the connecting hole are both connected to the reset chamber, and an overflow member cooperating with the second oil through hole is also movably arranged in the sealing stopper, the first end of the pipe joint body is connected to the brake valve through a hose, and the second end of the pipe joint body is connected to the brake chamber through a hard pipe, and the structural arrangement of the damping assembly in the pipe joint body can realize adaptive adjustment of the damping according to the pressure difference between the first end and the second end, thereby reducing the brake pressure overshoot caused by pressure shock, and further reducing the possibility of wheel locking caused by brake overshoot.

[0025] (2) The flexible cavity variable damping structure of the present invention is provided with a first oil hole and a pressure hole on the mover, and a second oil hole and a connecting hole are provided on the sealing baffle. When the pressure difference between the brake valve and the brake chamber exceeds a preset value (such as 18 MPa), the flow rate is relatively large during the initial impact process. By setting the connecting hole, the oil passing through the connecting hole will quickly adjust the oil pressure in the brake chamber. The oil pressure in the brake chamber can rise quickly, and the response speed is fast. Therefore, the present application has the dual effects of taking into account the pressure response speed and overshoot suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the three-dimensional structure of a flexible cavity variable damping structure provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the front structure of a flexible cavity variable damping structure provided in an embodiment of the present application;

[0029] Figure 3 for Figure 2 AA section diagram in;

[0030] Figure 4 A structural diagram of an overflow component of a flexible cavity variable damping structure provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram of the three-dimensional structure of a flexible cavity variable damping structure provided in another embodiment of the present application;

[0032] Figure 6 Schematic three - dimensional structure diagram of the flexible cavity variable damping structure provided for other embodiments of the present application;

[0033] Figure 7 Schematic three - dimensional structure diagram of the flexible cavity variable damping structure provided for another embodiment of the present application;

[0034] Figure 8 Schematic diagram of the flexible cavity variable damping structure provided for an embodiment of the present application in the initial steady state;

[0035] Figure 9 Schematic diagram of the flexible cavity variable damping structure provided for an embodiment of the present application in the boosting state;

[0036] Figure 10 Schematic diagram of state 1 of the flexible cavity variable damping structure provided for an embodiment of the present application;

[0037] Figure 11 Schematic diagram of state 2 of the flexible cavity variable damping structure provided for an embodiment of the present application;

[0038] Figure 12 Schematic diagram of the flexible cavity variable damping structure provided for an embodiment of the present application returning to the steady state;

[0039] Figure 13 It is the oil pressure regulation curve leading to the brake cavity (the curve of pressure change with time).

[0040] Wherein: 1 - pipe joint body, 11 - first end, 12 - second end, 13 - limiting part, 2 - hose, 3 - sealing stopper, 31 - second oil - passing hole, 32 - communication hole, 33 - first cylindrical part, 34 - second cylindrical part, 35 - inner cavity of the sealing stopper, 4 - limiting sleeve, 5 - rotor, 51 - first oil - passing hole, 52 - pressure - passing hole, 53 - third cylindrical part, 54 - fourth cylindrical part, 55 - inner cavity of the rotor, 6 - reset cavity, 7 - overflow part, 71 - conical part, 72 - guiding column, 73 - plane, 8 - first elastic part, 9 - second elastic part. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] Next, the present invention will be elaborated in detail in conjunction with the attached Figure 1 to the attached Figure 13 and specific embodiments.

[0043] Refer to Figures 1 to 13 , the present invention provides a flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve, which is installed between the brake valve outlet and the brake cavity to reduce the pressure impact in a high-speed switch. The flexible cavity variable damping structure of the present application includes a pipe joint body 1 and a hose 2. The pipe joint body 1 has an axially through structure and allows hydraulic oil to pass through during braking. The pipe joint body 1 has a first end 11 and a second end 12. The hose 2 is installed on the first end 11. A damping component is installed inside the pipe joint body 1. In the present application, the first end 11 of the pipe joint body 1 is connected to the brake valve outlet through the hose 2, and the second end 12 of the pipe joint body 1 is connected to the brake cavity through a rigid pipe. The damping component inside the pipe joint body 1 can achieve adaptive adjustment of damping according to the pressure difference between the first end 11 and the second end 12, so as to reduce the overshoot of the brake pressure caused by the pressure impact, and further reduce the possibility of wheel lock caused by brake overshoot. It should be noted that the hose 2 in the present application forms a flexible cavity, which can play a role in reducing hydraulic impact under the condition of large hydraulic pressure impact and play an auxiliary role in the process of variable damping.

[0044] The damping component includes a sealing stopper 3 and a limiting sleeve 4 that are axially and fixedly arranged within the pipe joint body 1, and a mover 5 that is axially movable and arranged between the sealing stopper 3 and the limiting sleeve 4. The limiting sleeve 4 is arranged close to the first end 11, and the sealing stopper 3 is arranged close to the second end 12. The axial distance between the limiting sleeve 4 and the sealing stopper 3 is the moving range of the mover 5. The mover 5 is provided with a first oil passage hole 51 and a pressure passage hole 52. The sealing stopper 3 is provided with a second oil passage hole 31 and a communication hole 32. The first oil passage hole 51 and the second oil passage hole 31 are arranged opposite to each other. The first oil passage hole 51 is communicated with the hose 2 through the inner cavity 55 of the mover and the inner cavity of the limiting sleeve 4. The second oil passage hole 31 is communicated with the brake cavity through the inner cavity 35 of the sealing stopper. When the mover 5 moves to the extreme position and contacts the sealing stopper 3, a reset cavity 6 is formed between the sealing stopper 3 and the mover 5. Both the pressure passage hole 52 and the communication hole 32 are communicated with the reset cavity 6. At the same time, the first oil passage hole 51 and the second oil passage hole 31 are butt-connected and communicated. It can be understood that when the pressure at the first end 11 is greater than the pressure at the second end 12, after the mover 5 axially moves to the extreme position and contacts the sealing stopper 3, there is still a cavity between the mover 5 and the sealing stopper 3, and this cavity is the reset cavity 6. The setting of the reset cavity 6 is an important part of the self-adaptive damping adjustment realized in this application. During the hydraulic impact process, through the design of the communication hole 32, the pressure passage hole 52 and the reset cavity 6 being communicated, the oil pressure leading to the reset cavity 6 is adjusted to quickly reset the mover 5, thereby reducing the overshoot caused by the oil impact. It should be noted that this application does not limit the shapes of the sealing stopper 3 and the mover 5, as long as when the sealing stopper 3 and the mover 5 are in contact, the first oil passage hole 51 and the second oil passage hole 31 are communicated, and the reset cavity 6 can be formed. Usually, the first oil passage hole 51 and the second oil passage hole 31 are coaxially arranged, and the pressure passage hole 52 is located on the outer periphery of the first oil passage hole 51, and the communication hole 32 is located on the outer periphery of the second oil passage hole 31.

[0045] An overflow member 7 that cooperates with the second oil passage hole 31 is also movably arranged inside the sealing member 3. The overflow member 7 can block or move away from the second oil passage hole 31. When the pressure at the first end 11 of the pipe joint body 1 is equal to the pressure at the second end 12, the rotor 5 moves away from the sealing member 3, and the overflow member 7 blocks the second oil passage hole 31. When the pressure at the first end 11 of the pipe joint body 1 is greater than the pressure at the second end 12, the rotor 5 moves to the limit position and contacts the sealing member 3, causing the first oil passage hole 51 to be aligned with the second oil passage hole 31. After alignment, the rotor 5 is in sealing contact with the sealing member 3, that is, the first oil passage hole 51 communicates with the second oil passage hole 31. And when the pressure difference between the first end 11 and the second end 12 is less than the preset pressure difference, the pressure at the first end 11 is not sufficient to push the overflow member 7, and the overflow member 7 blocks the second oil passage hole 31, and the oil fluid cannot flow out from the second oil passage hole 31, but can only enter the reset cavity 6 through the pressure equalizing hole 52, so that after the pressure difference between the first end 11 and the second end 12 is reduced, the rotor 5 is pushed back to the initial steady state. When the pressure difference between the first end 11 and the second end 12 is greater than the preset pressure difference, the overflow member 7 is pushed away from the second oil passage hole 31, the oil fluid enters the second oil passage hole 31 from the first oil passage hole 51, a part of the oil fluid flowing out from the second oil passage hole 31 enters the brake cavity, and another part of the oil fluid enters the reset cavity 6 from the communication hole 32. The pressure in the reset cavity 6 increases, so that the hydraulic pressure generated by the pressure difference at both ends of the rotor 5 decreases, and the rotor 5 is pushed back to the initial steady state. It should be noted that the shape of the overflow member 7 in this application is not limited, and it can be selected as spherical, conical, etc., but not limited to this.

[0046] The flexible cavity formed by the hose 2 of this application plays a role in reducing hydraulic shock. However, the space for the flexible cavity formed by the hose 2 to become larger is limited, and the role of reducing shock is also limited. Through the cooperation of the hose 2 and the damping assembly, the "variable damping" characteristic of this application is better.

[0047] It is worth noting that the specific setting position of the pressure equalizing hole 52 is not limited in this application. The above setting of the pressure equalizing hole 52 on the rotor 5 is only one embodiment. In other embodiments, such as Figure 7 shown, the pressure equalizing hole 52 can also be arranged on the sealing member 3, such as on the side wall of the second cylindrical portion 34 of the sealing member 3, that is, a pressure equalizing hole 52 is opened on the side wall of the second cylindrical portion 34 to communicate the second oil passage hole 31 and the reset cavity 6, and it can communicate the reset cavity 6 and the second oil passage hole 31, and the oil fluid can also enter the reset cavity 6 from the pressure equalizing hole 52.

[0048] Specifically, refer to Figure 6, when the pressure at the first end 11 is the same as the pressure at the second end 12, the mover 5 is in the initial steady state and contacts the limit sleeve 4. A gap is formed between the mover 5 and the sealing member 3. The oil fluid enters the reset cavity 6 from the gap after passing through the first oil passage hole 51 and flows out through the communication hole 32. Of course, in the initial steady state, a small amount of oil fluid will also communicate the pressures on both sides through the pressure passage hole 52.

[0049] Specifically, referring to Figure 3 , in some embodiments, an installation hole section is formed in the pipe joint body 1. The damping assembly is arranged in the installation hole section. A limiting portion 13 is provided on one side of the installation hole section close to the second end 12. A through hole is formed in the limiting portion 13, so that the oil fluid can flow from the through hole to the brake cavity; a first elastic member 8 is provided between the overflow member 7 and the limiting portion 13. When the pressure difference between the first end 11 and the second end 12 is less than the preset pressure difference, the first elastic member 8 pushes the overflow member 7 to block the second oil passage hole 31. Exemplarily, the installation hole section is a cylindrical hole, and the parts of the sealing member 3, the mover 5 and the limit sleeve 4 in sealing contact with the installation hole section are also cylindrical sections. Of course, in other embodiments, the installation hole section can also be polygonal, trapezoidal, rhombic, etc., but not limited thereto. The first elastic member 8 in the present application is preferably a spring that can be purchased on the market.

[0050] In some embodiments, referring to Figure 3 , both the first elastic member 8 and the overflow member 7 are located inside the sealing member 3. One end of the sealing member 3 far from the mover 5 abuts against the limiting portion 13. A sealing member inner cavity 35 is formed in the sealing member 3. The sealing member inner cavity 35 communicates with the second oil passage hole 31. Both the overflow member 7 and the first elastic member 8 are located in the sealing member inner cavity 35. In other embodiments, referring to Figure 5 , both the first elastic member 8 and the overflow member 7 are located between the sealing member 3 and the limiting portion 13. The sealing member 3 is fixed in the pipe joint body 1 by interference connection or welding. A cavity for the oil fluid to pass through is formed between the sealing member 3 and the limiting portion 13, realizing the communication of the oil fluid between the brake cavity and the brake valve.

[0051] In some embodiments, referring to Figure 6 , only the first oil passage hole 51 and the pressure passage hole 52 are provided on the mover 5, and no mover inner cavity 55 is provided. Both the first oil passage hole 51 and the pressure passage hole 52 communicate with the inner cavity of the limit sleeve 4, and the purpose of oil passing can also be achieved.

[0052] Specifically, a second elastic member 9 is provided between the sealing member 3 and the mover 5. The second elastic member 9 can push the mover 5 to move between the sealing member 3 and the limit sleeve 4; the second elastic member 9 is preferably a spring that can be purchased on the market;

[0053] When the pressure difference between the first end 11 and the second end 12 is less than the preset pressure difference, the oil fluid enters the reset cavity 6 from the pressure - through hole 52, reducing the pressure difference between the two ends of the pipe joint body 1, and the second elastic member 9 pushes the mover 5 to reset to the initial steady state;

[0054] When the pressure difference between the first end 11 and the second end 12 is greater than the preset pressure difference, the oil fluid enters the second oil - through hole 31 from the first oil - through hole 51 and flows out. A part of the flowing - out oil fluid enters the reset cavity 6 from the communication hole 32, reducing the pressure difference between the two ends of the pipe joint body 1 until the second elastic member 9 pushes the mover 5 to reset to the initial steady state. In this application, when the mover 5 moves towards the sealing stopper 3, the second elastic member 9 is in a compressed state. During the reset process of the mover 5, the second elastic member 9 and the pressure in the reset cavity 6 jointly act to push the mover 5 to reset.

[0055] Specifically, the diameter of the communication hole 32 is greater than the diameter of the pressure - through hole 52. It can be known that the greater the flow rate of the oil fluid entering the reset cavity 6, the faster the reset speed of the mover 5. Therefore, the diameter of the communication hole 32 being greater than that of the pressure - through hole 52 can ensure that when the pressure difference between the two ends is large, the oil fluid can quickly enter the reset cavity 6 through the communication hole 32 to quickly reset the mover 5. This application does not limit the quantity, shape, and positional relationship of the pressure - through hole 52 and the communication hole 32, and those skilled in the art can design according to specific usage scenarios.

[0056] In a preferred embodiment, refer to Figure 4 , the overflow member 7 is of a top - cone structure. The overflow member 7 includes a conical member 71 that mates with the second oil - through hole 31 and a guide post 72 fixed to the large - diameter end of the conical member 71. One end of the first elastic member 8 abuts against the limiting portion 13, and the other end is sleeved on the outer periphery of the guide post 72 to ensure the reasonable working direction of the first elastic member 8. In this application, the outer peripheral surface of the large - diameter end of the conical member 71 is configured to have at least two symmetrically arranged planes 73. An oil - through channel is formed between the plane 73 and the inner cavity 35 of the sealing stopper. By cutting part of the outer peripheral surface into the plane 73, it is more convenient for the oil fluid to enter the brake cavity through the inner cavity 35 of the sealing stopper.

[0057] Specifically, in this application, the pre - tightening force of the first elastic member 8 is greater than the pre - tightening force of the second elastic member 9, so that when the pressure difference between the first end 11 and the second end 12 is less than the preset pressure difference, the oil fluid can also push the mover 5 to move, but cannot push the overflow member 7 to move.

[0058] In a preferred embodiment, refer to Figure 8The sealing stopper 3 includes a first cylindrical portion 33 and a second cylindrical portion 34 which are coaxially arranged. The first cylindrical portion 33 and the second cylindrical portion 34 are connected. The outer diameter of the first cylindrical portion 33 is the same as the inner diameter of the mounting hole section. The sealing stopper inner cavity 35 is arranged in the first cylindrical portion 33. The outer diameter of the second cylindrical portion 34 is smaller than the outer diameter of the first cylindrical portion 33. The second oil hole 31 is opened on the second cylindrical portion 34. The connecting hole 32 is opened on the outer periphery of the second oil hole 31. The mover 5 includes a third cylindrical portion 53 and a fourth cylindrical portion 54 which are coaxially arranged. The third cylindrical portion 53 is connected to the fourth cylindrical portion 54. The outer diameter of the third cylindrical portion 53 is the same as the inner diameter of the mounting hole section. The mover inner cavity 55 is arranged in the third cylindrical portion 53. The outer diameter of the fourth cylindrical portion 54 is smaller than the outer diameter of the third cylindrical portion 53. The first oil hole 51 is opened on the fourth cylindrical portion 54. The pressure hole 52 is opened on the outer periphery of the first oil hole 51. The arrangement of the second cylindrical portion 34 and the fourth cylindrical portion 54 creates conditions for the formation of the reset cavity 6 , and at the same time, the second elastic member 9 is sleeved on the fourth cylindrical portion 54 to ensure that the working direction of the second elastic member 9 is reasonable.

[0059] In some embodiments, the sealing stopper 3 is fixed in the pipe joint body 1 by interference fit with the pipe joint body 1 , and the limiting sleeve 4 is fixed to the pipe joint body 1 by welding.

[0060] The flexible cavity variable damping structure of the present application is simple and reliable, and can realize adaptive adjustment of damping according to the pressure difference at both ends of the pipe joint body 1, has the effect of taking into account both pressure response speed and overshoot suppression, and can effectively reduce the possibility of wheel locking due to brake overshoot.

[0061] The present application is described in more detail below in conjunction with the working state of the flexible cavity variable damping structure.

[0062] Initial steady state (e.g. Figure 8 As shown): In the initial steady state, the output pressure of the brake valve is the same as the pressure in the brake chamber, the mover 5 is in contact with the limit sleeve 4, and is in a separated state from the sealing blocker 3, and the overflow member 7 blocks the second oil hole 31. The oil flowing out of the brake valve passes through the hose 2, the limit sleeve 4, the mover inner cavity 55, the first oil hole 51, the reset cavity 6 and the connecting hole 32 in turn and flows into the sealing blocker inner cavity 35 and finally flows into the brake chamber. Of course, a small amount of oil will also pass through the pressure-passing hole 52 to communicate the pressure on both sides. At this time, the pressure on both sides is the same, and the mover 5 and the overflow member 7 are both in the initial position.

[0063] Hydraulic shock state (such as Figure 9As shown in the figure: When the actuator needs to boost the pressure, the discrete digital brake valve is energized and opened, and the brake valve is connected to the oil source pressure. At this time, due to the impact of the oil, the mover 5 moves to the extreme left position and seals in contact with the sealing member 3. The change in the pressure difference between the two sides of the brake valve and the brake chamber will cause the flexible cavity variable damping structure to have two different states, state 1 and state 2. Adaptive damping adjustment can be achieved through differential pressure feedback.

[0064] State 1 (as Figure 10 shown): The pressure difference between the two sides of the brake valve and the brake chamber does not exceed 18 MPa (18 MPa is the preset pressure difference). At this time, the oil pressure cannot push the overflow member 7 and the first elastic member 8. The oil in the brake valve flows through the hose 2, the limit sleeve 4, the inner cavity 55 of the mover, and the pressure hole 52 into the reset cavity 6 in sequence to reduce the pressure mutation caused by hydraulic shock. When the pressure difference between the two sides decreases, the second elastic member 9 pushes the mover 5 back to the initial steady state. It should be noted that because the pressure difference between the two sides of the brake valve and the brake chamber does not exceed 18 MPa, the hydraulic pressure cannot overcome the pre-tightening force of the first elastic member 8, and the overflow member 7 blocks the second oil passage hole 31.

[0065] State 2 (as Figure 11 shown): If the pressure difference between the two sides of the brake valve and the brake chamber exceeds 18 MPa, at this time, the hydraulic pressure generated by the pressure difference is greater than the pre-tightening force of the first elastic member 8, and the overflow member 7 is pushed to the left. The oil flowing out of the brake valve flows through the hose 2, the limit sleeve 4, the inner cavity 55 of the mover, the first oil passage hole 51, and the second oil passage hole 31 into the inner cavity 35 of the sealing member. Part of the oil flowing into the inner cavity 35 of the sealing member flows into the brake chamber, and another part of the oil flows into the reset cavity 6. At this time, the pressure in the reset cavity 6 increases, and the hydraulic pressure generated by the pressure difference at both ends of the mover 5 decreases. Under the combined action of the hydraulic pressure and the pre-tightening force of the second elastic member 9, the mover 5 is pushed to reset (move to the right). At this time, compared with state 1, the mover 5 can be reset faster.

[0066] It can be known that in state 1, the pressure difference between the two sides of the brake valve and the brake chamber is small, the impact of the oil is small, and the oil can flow through the pressure hole 52 into the brake chamber to reduce the overshoot caused by the hydraulic oil impact. In state 2, the pressure difference between the two sides of the brake valve and the brake chamber is large, the impact of the oil is large, and the mover 5 needs to be quickly reset to reduce the overshoot caused by the large oil impact; in this application, the diameter of the communication hole 32 is larger than the diameter of the pressure hole 52, so that the oil can quickly enter the reset cavity 6 from the communication hole 32, and then the mover 5 can be quickly reset.

[0067] In addition, since the flow rate is larger during the initial impact process of state 2, the reduction in the response speed caused by damping can be avoided. Specifically, it is shown that: if only the oil passes through the small-diameter pressure hole 52 (state 1), the oil pressure leading to the brake chamber will rise slowly, and the response speed is slow (as Figure 13In the medium adjustment curve (shown by the blue curve); if the oil fluid enters the brake chamber from the second oil passage hole 31 (state 2), it will quickly adjust the oil pressure leading to the brake chamber, and the oil pressure leading to the brake chamber can quickly rise, with a fast response speed (as shown by the red curve in the medium adjustment curve). Figure 13 as shown by the red curve in the medium adjustment curve).

[0068] Return to the state (as shown by Figure 12 shown): When the hydraulic shock ends, the mover 5 resets, and the oil continues to pass through the gap between the mover 5 and the sealing member 3 on both sides, the damping ends, and finally the two chambers return to the steady state.

[0069] The above further describes the present invention with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as a limitation on the essence and scope of the present invention. Various modifications made by those of ordinary skill in the art to the above embodiments after reading this specification all fall within the scope protected by the present invention.

Claims

1. A flexible cavity variable damping structure for reducing pressure shock of a discrete digital brake valve, characterized in that It includes a pipe joint body and a hose. The pipe joint body has a first end and a second end. The hose is installed on the first end and is used to connect to a brake valve. The second end is used to connect to a brake chamber. A damping component is installed inside the pipe joint body. The damping component includes a sealing stopper and a limiting sleeve that are axially spaced and fixed inside the pipe joint body, and a mover that is axially movably arranged between the sealing stopper and the limiting sleeve. The limiting sleeve is close to the first end, and the sealing stopper is close to the second end. The mover is provided with a first oil passage hole, and the sealing stopper is provided with a second oil passage hole. When the mover contacts the sealing stopper, the first oil passage hole communicates with the second oil passage hole, and a reset cavity is formed between the sealing stopper and the mover. A communication hole and a pressure passage hole are provided on the side wall of the reset cavity. The communication hole and the second oil passage hole both communicate with the brake chamber, and the pressure passage hole and the first oil passage hole communicate with the hose. An overflow component is also movably arranged inside the pipe joint body, and the overflow component can block or move away from the second oil passage hole. When the pressure at the first end is equal to the pressure at the second end, the mover moves away from the sealing stopper, and the overflow component blocks the second oil passage hole. When the pressure at the first end is greater than the pressure at the second end, the mover moves to contact the sealing stopper. When the pressure difference between the first end and the second end is less than a preset pressure difference, the overflow component blocks the second oil passage hole. When the pressure difference between the first end and the second end is greater than the preset pressure difference, the overflow component moves away from the second oil passage hole.

2. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 1, characterized in that There is at least one communication hole and it is provided on the sealing stopper. There is at least one pressure passage hole and it is provided on the mover. The diameter of the communication hole is greater than the diameter of the pressure passage hole.

3. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 1, characterized in that An installation hole section is formed inside the pipe joint body. The damping component is arranged inside the installation hole section. A limiting portion is provided on one side of the installation hole section close to the second end. A first elastic member is provided between the overflow component and the limiting portion. When the pressure difference between the first end and the second end is less than the preset pressure difference, the first elastic member pushes the overflow component to block the second oil passage hole.

4. The flexible cavity variable damping structure for reducing the pressure shock of a discrete digital brake valve according to claim 3, wherein A second elastic member is provided between the sealing stopper and the mover, and the second elastic member can push the mover to move between the sealing stopper and the limiting sleeve. When the pressure at the first end is the same as the pressure at the second end, the mover is in an initial steady state and contacts the limiting sleeve. A gap is formed between the mover and the sealing stopper. The oil fluid enters the reset cavity from the gap after passing through the first oil passage hole and flows out through the communication hole. When the pressure difference between the first end and the second end is less than the preset pressure difference, the oil fluid enters the reset cavity from the pressure passage hole, reducing the pressure difference between the two ends of the pipe joint body, and the second elastic member pushes the mover to reset to the initial steady state. When the pressure difference between the first end and the second end is greater than a preset pressure difference, the hydraulic oil enters the second oil passage hole from the first oil passage hole and flows out. A part of the flowing-out hydraulic oil enters the reset cavity from the communication hole, reducing the pressure difference between both ends of the pipe joint body, and pushing the mover to reset to the initial steady state through the second elastic member.

5. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 3, characterized in that, The overflow member is of a top cone structure. The overflow member includes a conical member that cooperates with the second oil passage hole and a guide post fixed to the large-diameter end of the conical member. One end of the first elastic member abuts against the limiting portion, and the other end is sleeved on the outer periphery of the guide post.

6. The flexible cavity variable damping structure for reducing the pressure shock of a discrete digital brake valve according to claim 5, characterized in that The outer peripheral surface of the large-diameter end of the conical member is configured to have at least two symmetrically arranged planes, and an oil passage is formed between the plane and the inner cavity of the sealing baffle.

7. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 4, characterized in that, The pre-tightening force of the first elastic member is greater than the pre-tightening force of the second elastic member.

8. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 3, characterized in that, The sealing baffle includes a first cylindrical portion and a second cylindrical portion arranged coaxially. The first cylindrical portion is connected to the second cylindrical portion. The outer diameter of the first cylindrical portion is the same as the inner diameter of the installation hole section. The outer diameter of the second cylindrical portion is smaller than the outer diameter of the first cylindrical portion. The second oil passage hole is opened on the second cylindrical portion, and the communication hole is opened on the outer periphery of the second oil passage hole.

9. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 3, wherein, The mover includes a third cylindrical portion and a fourth cylindrical portion arranged coaxially. The third cylindrical portion is connected to the fourth cylindrical portion. The outer diameter of the third cylindrical portion is the same as the inner diameter of the installation hole section. The outer diameter of the fourth cylindrical portion is smaller than the outer diameter of the third cylindrical portion. The first oil passage hole is opened on the fourth cylindrical portion, and the pressure communication hole is opened on the outer periphery of the first oil passage hole.

10. The flexible cavity variable damping structure for reducing the pressure impact of a discrete digital brake valve according to claim 1, characterized in that, The sealing baffle is fixed in the pipe joint body by interference fit with the pipe joint body, and the limit sleeve is fixedly welded to the pipe joint body.

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