Hydraulic load-sensing proportional valve and brake system for vehicles

Abstract

The present invention relates to the field of vehicle control technology, and more specifically, to a hydraulic load-sensing proportional valve and brake system for a vehicle. The valve comprises a housing, a front piston, a front piston elastic member, a one-way valve elastic member, and a one-way valve ball; the front piston is disposed in a front chamber via the front piston elastic member; the one-way valve elastic member provides an elastic force that moves the one-way valve ball toward a valve port to seal the valve port; and a rear piston, a rear piston elastic member, an adjusting screw, an adjusting screw elastic member, a load-sensing elastic member seat, and a load-sensing compression elastic member. The rear piston comprises a body and a piston rod; the piston rod passes through a mating channel and is capable of moving the one-way valve ball away from the valve port; the end of the adjusting screw passes through a rear chamber to abut against the body of the rear piston; the adjusting screw elastic member provides an elastic force that moves the adjusting screw toward the rear piston; and the load-sensing compression elastic member provides an elastic force that moves the adjusting screw and the load-sensing elastic member seat away from each other. This allows for dynamic distribution of hydraulic pressure in the front and rear wheel brake systems.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a hydraulic load-sensing proportional valve and a braking system for a vehicle. Background Art

[0002] With the development of braking technology, most two-wheeled motorcycles on the market are equipped with a linked braking system, which means that the front and rear wheel brakes are driven simultaneously by separately operating the front brake master cylinder or the rear brake master cylinder, thereby achieving a greater deceleration.

[0003] During the actual braking process, as the vehicle load changes, the weight borne by the front and rear wheels will gradually change, and the braking force provided by the ground to the rear wheels will gradually change, thereby limiting the maximum deceleration that the vehicle can achieve.

[0004] However, existing linked braking systems mostly have fixed ratios and do not dynamically distribute the front and rear wheel braking forces as the weight of the front and rear wheels changes, so they cannot achieve a large deceleration under any working condition. Summary of the Invention

[0005] The objects of the present invention include, for example, providing a hydraulic load-sensing proportional valve and brake system for a vehicle, which can dynamically distribute the hydraulic pressure of the front and rear wheel brake systems as the load on the front and rear wheels of the vehicle changes, thereby achieving a larger deceleration under any working condition.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] In a first aspect, the present invention provides a hydraulic load-sensing proportional valve for a vehicle, comprising:

[0008] a housing having a front chamber and a rear chamber communicating with each other;

[0009] A front piston, a front piston elastic member, a one-way valve elastic member and a one-way valve ball; the front piston is movably arranged in the front chamber; the front chamber, the side wall of the front piston away from the rear chamber, and the input port on the shell together enclose a closed input chamber; the front piston is arranged in the front chamber through the front piston elastic member, and the front piston elastic member provides an elastic force to move the front piston toward the rear chamber; the front piston has a matching channel running through the axis, and the matching channel forms a valve port on the side away from the rear chamber; the one-way valve ball is arranged in the front chamber through the one-way valve elastic member, and the one-way valve elastic member provides an elastic force to move the one-way valve ball toward the valve port to seal the valve port;

[0010] and a rear piston, a rear piston elastic member, an adjusting screw, an adjusting screw elastic member, a load-sensing elastic member seat, and a load-sensing compression elastic member; the rear chamber, the side wall of the rear piston against the front chamber, and the output port on the shell together enclose a closed output chamber; the rear piston includes a body and a piston column connected in sequence; the piston column passes through the matching channel and can abut the one-way valve ball to keep the one-way valve ball away from the valve port; the body is abutted against the inner wall of the rear chamber away from the front chamber by the rear piston elastic member, and the rear piston elastic member provides an elastic force to move the body away from the rear chamber toward the front chamber;

[0011] The end of the adjusting screw passes through the rear chamber to abut against the body of the rear piston; the end of the adjusting screw close to the rear piston is arranged on the housing through the adjusting screw elastic member, and the adjusting screw elastic member provides elastic force to move the adjusting screw toward the rear piston;

[0012] The other end of the adjusting screw away from the rear piston is connected to the load-sensing elastic member seat through the load-sensing compression elastic member; the adjusting screw can movably pass through the load-sensing elastic member seat, and the load-sensing compression elastic member provides an elastic force to move the adjusting screw and the load-sensing elastic member seat away from each other.

[0013] In an optional embodiment, an adjusting gasket is further included; the load-sensing compression elastic member is arranged between the load-sensing elastic member seat and the adjusting gasket;

[0014] The adjusting washer is movably arranged on the adjusting screw along the axial direction of the adjusting screw to adjust the pre-compression elastic force of the load-sensing compression elastic member.

[0015] In an optional embodiment, an adjustment member is further included;

[0016] The adjusting member is threadedly connected to the adjusting screw to move away from or closer to the load-sensing elastic member seat;

[0017] The adjusting gasket is arranged on the adjusting member.

[0018] In an optional embodiment, a limit pin is further included, and the limit pin is arranged on a side of the rear chamber away from the output chamber;

[0019] A waist-shaped hole is provided on the body of the rear piston, and the limiting pin passes through the waist-shaped hole.

[0020] In an optional embodiment, a matching hole is provided on the surface of the shell and penetrates at least to the rear chamber, and one end of the limiting pin passes through the matching hole and is inserted into the waist-shaped hole.

[0021] In an optional embodiment, the side of the limiting pin away from the waist-shaped hole is threadedly connected to the matching hole.

[0022] In an optional embodiment, a dust cover is further included;

[0023] The dustproof sleeve is arranged between the load-sensing elastic member seat and the housing, and the adjusting screw, the adjusting screw elastic member and the load-sensing compression elastic member are all located in the dustproof sleeve.

[0024] In an optional embodiment, a stopper and an adjusting screw elastic member seat are further included;

[0025] The adjusting screw elastic member seat is arranged on a side of the housing away from the front chamber and the rear chamber, and the adjusting screw elastic member seat and the housing are enclosed to form an accommodating cavity; the limiter and the adjusting screw elastic member are both located in the accommodating cavity;

[0026] The adjusting screw passes through the adjusting screw elastic member seat;

[0027] The limiter is fixedly arranged on the adjusting screw, and the adjusting screw elastic member is arranged between the inner wall of the adjusting screw elastic member seat and the limiter.

[0028] In an optional embodiment, it further includes an open retaining ring;

[0029] The open retaining ring is located in the accommodating cavity, the adjusting screw is provided with a circumferentially extending slot, and the open retaining ring is inserted into the slot; the limiter is supported on a side of the open retaining ring away from the shell.

[0030] In a second aspect, the present invention provides a braking system, comprising the vehicle hydraulic load-sensing proportional valve according to any one of the aforementioned embodiments.

[0031] The beneficial effects of the embodiments of the present invention include, for example:

[0032] The hydraulic load-sensing proportional valve for vehicles in this embodiment includes a housing, a front piston, a front piston elastic member, a check valve elastic member, a check valve ball, a rear piston, a rear piston elastic member, an adjusting screw, an adjusting screw elastic member, a load-sensing elastic member seat, and a load-sensing compression elastic member. The front piston, front piston elastic member, check valve elastic member, and check valve ball form a first-stage piston structure, while the rear piston, rear piston elastic member, adjusting screw, adjusting screw elastic member, load-sensing elastic member seat, and load-sensing compression elastic member form a second-stage piston structure. This split, two-stage piston arrangement ensures that the hydraulic input and output chambers are connected when the valve body is not in operation. When in operation, the hydraulic input and output chambers are disconnected, limiting the maximum output hydraulic pressure. Furthermore, the load-sensing compression elastic member has a spring force that varies with vehicle load, thereby adjusting the maximum output hydraulic pressure under different vehicle conditions. This allows for dynamic distribution of front and rear wheel brake system hydraulic pressure as the front and rear wheel loads change, achieving a high deceleration rate under all operating conditions. In summary, such a hydraulic load-sensing proportional valve for vehicles is easy to operate and easy to control, and can be improved based on the existing valve body, so it has outstanding economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a schematic diagram of the assembly of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic structural diagram of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic structural diagram of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention at the initial state of light load;

[0037] Figure 4 This is a schematic structural diagram of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention at a late light-load stage;

[0038] Figure 5 This is a schematic structural diagram of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention at the initial stage of heavy load;

[0039] Figure 6 This is a schematic structural diagram of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention at a late heavy load stage;

[0040] Figure 7An output-output hydraulic pressure distribution curve diagram of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention;

[0041] Figure 8 A schematic structural diagram of a specific example of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention;

[0042] Figure 9 This is a front and rear wheel braking force curve diagram of a specific example of a hydraulic load-sensing proportional valve for a vehicle according to an embodiment of the present invention.

[0043] Icon: 1-housing; 1a-front chamber; 1b-rear chamber; 2-front piston elastic part; 3-O-ring; 4-front end cover; 5-hexagonal screw plug; 6-one-way valve elastic part; 7-one-way valve ball; 8-front piston; 9-inner Y-ring; 10-outer Y-ring; 11-rear piston; 12-rear piston elastic part; 13-opening retaining ring; 14-limiter; 15-adjusting screw elastic part; 16-adjusting part; 17-gasket; 18-load-sensing compression elastic part; 19-load-sensing elastic part seat gasket; 20-load-sensing elastic part seat; 21-adjusting screw; 22-dust cover; 23-screw; 24-adjusting screw elastic part seat; 25-hexagonal screw socket; 26-limit pin; 27-waist-shaped hole; 28-matching channel; 29-valve port; A-input chamber; B-output chamber. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0047] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0048] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0049] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0050] With the development of braking technology, most two-wheeled motorcycles on the market are equipped with a linked braking system, which means that the front and rear wheel brakes are driven simultaneously by separately operating the front brake master cylinder or the rear brake master cylinder, thereby achieving a greater deceleration.

[0051] During the actual braking process, as the vehicle load changes, the weight borne by the front and rear wheels will gradually change, and the braking force provided by the ground to the rear wheels will gradually change, thereby limiting the maximum deceleration that the vehicle can achieve.

[0052] However, existing linked braking systems mostly have fixed ratios and do not dynamically distribute the front and rear wheel braking forces as the weight of the front and rear wheels changes, so they cannot achieve a large deceleration under any working condition.

[0053] To improve the above technical problems, a hydraulic load-sensing proportional valve and a braking system for a vehicle are provided in the following embodiments.

[0054] Please refer to Figure 1 This embodiment provides a hydraulic load-sensing proportional valve for a vehicle. The hydraulic load-sensing proportional valve is assembled between the vehicle frame and the rear wheel fork according to the design state, and includes:

[0055] The housing 1 has a front chamber 1a and a rear chamber 1b that are interconnected;

[0056] Front piston 8, front piston elastic member 2, one-way valve elastic member 6 and one-way valve ball 7; the front piston 8 is movably arranged in the front chamber 1a; the front chamber 1a, the side wall of the front piston 8 away from the rear chamber 1b, and the input port on the housing 1 together enclose a closed input chamber A; the front piston 8 is arranged in the front chamber 1a through the front piston elastic member 2, and the front piston elastic member 2 provides an elastic force to move the front piston 8 toward the rear chamber 1b; the front piston 8 has a matching channel 28 running through the axis, and the matching channel 28 forms a valve port 29 on the side away from the rear chamber 1b; the one-way valve ball 7 is arranged in the front chamber 1a through the one-way valve elastic member 6, and the one-way valve elastic member 6 provides an elastic force to move the one-way valve ball 7 toward the valve port 29 to seal the valve port 29;

[0057] and the rear piston 11, the rear piston elastic member 12, the adjusting screw 21, the adjusting screw elastic member 15, the load-sensing elastic member seat 20, and the load-sensing compression elastic member 18; the rear chamber 1b, the side wall of the rear piston 11 close to the front chamber 1a, and the output port on the housing 1 together enclose a closed output chamber B; the rear piston 11 includes a body and a piston rod connected in sequence; the piston rod is penetrated by a matching channel 28 and can abut the one-way valve ball 7 to keep the one-way valve ball 7 away from the valve port 29; the body is abutted against the inner wall of the rear chamber 1b away from the front chamber 1a by the rear piston elastic member 12, and the rear piston elastic member 12 provides an elastic force to move the body away from the rear chamber 1b toward the front chamber 1a;

[0058] The end of the adjusting screw 21 passes through the rear chamber 1b to abut against the body of the rear piston 11. The end of the adjusting screw 21 close to the rear piston 11 is arranged on the housing 1 through the adjusting screw elastic member 15. The adjusting screw elastic member 15 provides elastic force to move the adjusting screw 21 toward the rear piston 11.

[0059] The other end of the adjusting screw 21 away from the rear piston 11 is connected to the load-sensing elastic member seat 20 through the load-sensing compression elastic member 18; the adjusting screw 21 can movably pass through the load-sensing elastic member seat 20, and the load-sensing compression elastic member 18 provides an elastic force to move the adjusting screw 21 and the load-sensing elastic member seat 20 away from each other.

[0060] During use, the front piston 8, front piston elastic member 2, one-way valve elastic member 6, and one-way valve ball 7 form a first-stage piston structure, while the rear piston 11, rear piston elastic member 12, adjusting screw 21, adjusting screw elastic member 15, load-sensing elastic member seat 20, and load-sensing compression elastic member 18 form another-stage piston structure. This split two-stage piston arrangement allows the hydraulic input chamber A to communicate with the output chamber B when the valve body is not in operation, and the hydraulic input chamber A and output chamber B to be disconnected when in operation, limiting the maximum output hydraulic pressure. Furthermore, the load-sensing compression elastic member 18 is provided, and its elastic force changes with vehicle load, thereby varying the maximum output hydraulic pressure under different vehicle conditions. This allows the front and rear wheel brake system hydraulic pressure to be dynamically distributed as the front and rear wheel loads change, resulting in a greater deceleration under any operating condition.

[0061] Please continue reading Figures 1 to 6 , to learn more structural details of the hydraulic load-sensing proportional valve for vehicles.

[0062] As can be seen from the figure, the end of the adjusting screw 21 is a round convex head, and the end of the rear piston 11 body away from the front piston 8 has a round groove. The round convex head can be embedded in the round groove.

[0063] During installation, the hydraulic load-sensing proportional valve is assembled between the frame and the rear wheel fork according to the design state. When the vehicle load changes, causing the distance between the frame and the rear wheel fork to change, the compression length of the load-sensing compression elastic member 18 in the hydraulic load-sensing proportional valve changes accordingly.

[0064] Specifically, the housing 1 and the load-sensing elastic member seat 20 are mounted on the vehicle frame and the rear wheel fork, respectively. Therefore, when the vehicle load changes, the force on the housing 1 increases, causing the adjusting screw 21 to move away from the housing 1 and extend out of the load-sensing elastic member seat 20, thereby reducing the elastic force on the rear piston 11.

[0065] Furthermore, in this embodiment, the front piston elastic member 2, the one-way valve elastic member 6, the rear piston elastic member 12, the adjusting screw 21, the adjusting screw elastic member 15, and the load-sensing compression elastic member 18 are all elastic members. The one-way valve ball 7 is a one-way valve ball 7.

[0066] Optionally, the shell 1 is a PVC structure, that is, a PVC shell 1.

[0067] The front chamber 1a has a removably connected front cover 4 on the side away from the rear chamber 1b. This cover 4 is tightly connected to the inner wall of the front chamber 1a via an O-ring 3. One end of the front piston elastic member 2 abuts against a one-way valve ball 7, while the other end abuts against the inner wall of the front cover 4 via a hexagon socket screw 5.

[0068] Specifically, the load-sensing elastic member is arranged on the edge of the load-sensing elastic member seat 20 through the load-sensing elastic member seat gasket 19 , so as to ensure that the load-sensing elastic member and the load-sensing elastic member seat 20 are stably supported.

[0069] As can be seen from the figure, the hydraulic load-sensing proportional valve for vehicles also includes an adjusting gasket 17; the load-sensing compression elastic member 18 is arranged between the load-sensing elastic member seat 20 and the adjusting gasket 17; along the axial direction of the adjusting screw 21, the adjusting gasket 17 is movably arranged on the adjusting screw 21 to adjust the pre-compression elastic force of the load-sensing compression elastic member 18.

[0070] Furthermore, in this embodiment, the vehicle hydraulic load-sensing proportional valve further includes an adjusting member 16; the adjusting member 16 is threadedly connected to the adjusting screw 21 to move away from or closer to the load-sensing elastic member seat 20; and an adjusting washer 17 is disposed on the adjusting member 16. Optionally, the adjusting member 16 comprises two nuts disposed on the adjusting screw 21. The two nuts abut to form a locked state, thereby ensuring that the adjusting member 16 and the adjusting washer 17 are fixed to the adjusting screw 21.

[0071] As can also be seen from the figure, in this embodiment of the present invention, the vehicle hydraulic load-sensing proportional valve also includes a stop pin 26, which is located on the side of the rear chamber 1b away from the output chamber B. The body of the rear piston 11 is provided with a waist-shaped hole 27, through which the stop pin 26 passes. The stop pin 26 cooperates with the waist-shaped hole 27 to prevent axial movement of the rear piston 11 when not in operation.

[0072] Optionally, a matching hole is provided on the surface of the housing 1 at least extending through the rear chamber 1b, and one end of the limiting pin 26 passes through the matching hole and is inserted into the waist-shaped hole 27. The side of the limiting pin 26 away from the waist-shaped hole 27 is threadedly connected to the matching hole.

[0073] Furthermore, a hexagonal screw thread 25 is provided on the top of the limiting pin 26 to facilitate the disassembly of the limiting pin 26 and the matching hole.

[0074] It can also be seen from the figure that in this embodiment of the present invention, the hydraulic load-sensing proportional valve for vehicles also includes a dust cover 22; the dust cover 22 is arranged between the load-sensing elastic member seat 20 and the housing 1, and the adjusting screw 21, the adjusting screw elastic member 15 and the load-sensing compression elastic member 18 are all located in the dust cover 22.

[0075] Furthermore, the hydraulic load-sensing proportional valve for vehicles also includes a limiter 14 and an adjusting screw elastic member seat 24; the adjusting screw elastic member seat 24 is arranged on the side of the shell 1 away from the front chamber 1a and the rear chamber 1b, and the adjusting screw elastic member seat 24 and the shell 1 are enclosed to form an accommodating cavity; the limiter 14 and the adjusting screw elastic member 15 are both located in the accommodating cavity; the adjusting screw 21 passes through the adjusting screw elastic member seat 24; the limiter 14 is fixed on the adjusting screw 21, and the adjusting screw elastic member 15 is arranged between the inner wall of the adjusting screw elastic member seat 24 and the limiter 14.

[0076] In this embodiment, the adjusting screw elastic member seat 24 is in the shape of a cap, and the edge of the adjusting screw elastic member seat 24 is connected to the housing 1 via a screw 23 .

[0077] Optionally, the vehicle hydraulic load-sensing proportional valve further includes an open retaining ring 13 ; the open retaining ring 13 is located in the accommodating cavity, and the adjusting screw 21 is provided with a circumferentially extending slot into which the open retaining ring 13 is engaged; and the limiter 14 abuts against the side of the open retaining ring 13 away from the housing 1 . The open retaining ring 13 is an elastic retaining ring, which facilitates removal and installation of the limiter 14 and the adjusting screw 21 .

[0078] Specifically, the front piston 8 is pressed against the rear piston 11 under the action of the front piston elastic member 2, so that the front piston 8 does not move axially in the non-operating state; two inner Y-shaped rings 9 installed in opposite directions are provided on the front piston 8, which are used to seal the hydraulic chamber of the front piston 8 and the hydraulic chamber of the rear piston 11 respectively; a one-way valve structure is formed on the front piston 8 by providing a hexagonal screw plug 5, a one-way valve elastic member 6, and a one-way valve ball 7;

[0079] When not in operation, the one-way valve ball 7 is separated from the conical sealing surface (i.e., valve port 29) on the front piston 8 by the action of the rear piston 11, that is, the one-way valve remains in a normally open state when not in operation;

[0080] Under the action of the rear piston elastic member 12, the rear piston 11 contacts the limit pin 26 fixed on the PCV housing 1, so that the rear piston 11 has no axial movement when not in operation; and an outer Y-shaped ring 10 is provided on the rear piston 11 to form a sealed structure for the output chamber B.

[0081] The adjusting screw 21 contacts the rear piston 11 under the action of the adjusting screw elastic member 15, and the elastic force of the load-sensing compression elastic member 18 is transmitted to the rear piston 11 through the adjusting screw 21;

[0082] One end of the load-sensing compression elastic member 18 contacts the load-sensing elastic member seat 20, and the other end contacts the gasket 17. By adjusting the position of the nut on the adjusting screw 21, the pre-compression elastic force of the load-sensing compression elastic member 18 can be adjusted;

[0083] The working principle of the hydraulic load-sensing proportional valve for vehicles is as follows:

[0084] ① Non-working state

[0085] In the non-working state, the one-way valve ball 7 in the one-way valve structure is separated from the conical sealing surface on the front piston 8 under the action of the rear piston 11, so that chambers A and B are connected, that is, the hydraulic input chamber A is connected to the output chamber B, see Figure 2 .

[0086] ②Working status——light load condition

[0087] like Figure 3 、 Figure 4 As shown, the hydraulic load-sensing proportional valve is assembled between the vehicle frame and the rear wheel fork according to the design state. When the vehicle load changes, resulting in a change in the distance between the frame and the rear wheel fork, the compression length of the load-sensing compression elastic member 18 in the hydraulic load-sensing proportional valve changes accordingly;

[0088] When the load is light (one person riding), the hydraulic load-sensing proportional valve is in the state shown in the figure. In the initial state, the one-way valve formed by the front piston 8, the hexagon socket screw plug 5, the one-way valve elastic member 6, and the one-way valve ball 7 is in a normally open state. Before the one-way valve closes, the hydraulic pressure in the output chamber B of the hydraulic load-sensing proportional valve is equal to the input hydraulic pressure.

[0089] Please refer to 3 and Figure 4 As the hydraulic pressure in the valve input chamber A increases, the rear piston 11 begins to move rightward, overcoming the elastic forces of the load-sensing compression elastic member 18, the rear piston elastic member 12, and the adjusting screw elastic member 15, until the rear piston 11 contacts the bottom of the rear piston 11 cavity in the PCV housing 1. During this process, the front piston 8 moves rightward under the action of the front piston elastic member 2 until it contacts the bottom of the front piston 8 cavity in the PCV housing 1.

[0090] Because the movement distance of the rear piston 11 is greater than that of the front piston 8, the one-way valve formed by the front piston 8, the hexagonal screw plug 5, the one-way valve elastic member 6, and the one-way valve ball 7 will eventually be in a closed state; when the one-way valve is closed, the output hydraulic value will remain constant and will no longer increase with the hydraulic pressure of the input chamber A, thus achieving constant pressure output.

[0091] ③Working status——heavy load condition

[0092] like Figure 5 and Figure 6 As shown, when the vehicle load increases further, the load-sensing compression elastic member 18 in the hydraulic load-sensing proportional valve is further compressed, as shown in FIG. Figure 6 As shown, in the initial state, the one-way valve formed by the front piston 8, the hexagon socket screw plug 5, the one-way valve elastic member 6, and the one-way valve ball 7 is in a normally open state. Before the one-way valve is closed, the hydraulic pressure in the output chamber B of the hydraulic load-sensing proportional valve is equal to the input hydraulic pressure;

[0093] As the hydraulic pressure in the valve input chamber A increases, the rear piston 11 begins to move rightward, overcoming the elastic forces of the load-sensing compression elastic member 18, the rear piston elastic member 12, and the adjusting screw elastic member 15, until the rear piston 11 contacts the bottom of the rear piston 11 cavity in the PCV housing 1. During this process, the front piston 8 moves rightward under the action of the front piston elastic member 2 until it contacts the bottom of the front piston 8 cavity in the PCV housing 1.

[0094] Because the rear piston 11 moves farther than the front piston 8, the one-way valve formed by the front piston 8, hexagon socket screw 5, one-way valve elastic member 6, and one-way valve ball 7 is ultimately closed. Once the one-way valve is closed, the output hydraulic pressure remains constant and no longer increases with the hydraulic pressure in the input chamber A, achieving a constant-pressure output. Because the load-sensing compression elastic member 18 is further compressed, the output constant-pressure hydraulic pressure under heavy loads is greater than that under light loads.

[0095] contrast Figures 3 to 6 It can be seen that, compared with the light load, the length of the portion of the adjusting screw 21 extending away from the housing 1 from the load-sensing elastic member seat 20 is longer under heavy load.

[0096] The above light load and heavy load working states are only examples. Affected by factors such as load, driver posture, road conditions, etc., the actual braking working state will be very different. In theory, this hydraulic load sensing proportional valve will have countless output-output hydraulic distribution curves, such as Figure 7 shown.

[0097] See also Figure 8 and Figure 9 , shows an example of a vehicle hydraulic load-sensing proportional valve actually being used in a motorcycle brake system. Figure 8 It can be seen that the motorcycle's foot brake master pump is connected to the input chamber A of the vehicle's hydraulic load-sensing proportional valve and the front caliper respectively; the output chamber B of the vehicle's hydraulic load-sensing proportional valve is connected to the rear caliper.

[0098] Figure 9 The figure shows the braking force distribution of the aforementioned braking system. As can be seen from the figure, regardless of whether the load is light or heavy, and regardless of ideal distribution or actual braking distribution, the vehicle's hydraulic load-sensing proportional valve ensures stable and continuous rear wheel braking force. At the same time, the rear wheel braking force under heavy load is greater than that under light load. The overall curve shows that in the initial braking phase, the rear wheel braking force is greater than the front wheel braking force, and the braking force value increases faster. When the braking force output by the vehicle's hydraulic load-sensing proportional valve remains balanced and does not increase, the front wheel braking force begins to remain greater than the rear wheel braking force.

[0099] In a second aspect, the present invention provides a braking system, comprising the vehicle hydraulic load-sensing proportional valve according to any one of the aforementioned embodiments.

[0100] In summary, the embodiments of the present invention provide a hydraulic load-sensing proportional valve and a braking system for a vehicle, which have at least the following advantages:

[0101] 1. A split two-stage piston is provided. A one-way valve structure is formed by setting a hexagonal screw plug 5, a one-way valve elastic member 6, and a one-way valve ball 7 on the front piston 8. When the valve body is in the non-operating state, the hydraulic input chamber A and the output chamber B are connected. When in the operating state, the hydraulic input chamber A and the output chamber B are not connected, thereby limiting the maximum output hydraulic pressure.

[0102] 2. A load-sensing compression elastic member 18 is provided, the elastic force of which changes with the vehicle load, thereby changing the maximum output hydraulic pressure under different vehicle conditions;

[0103] 3. One end of the load-sensing compression elastic member 18 contacts the load-sensing elastic member seat 20 , and the other end contacts the gasket 17 . The pre-compression elastic force of the load-sensing compression elastic member 18 can be adjusted by adjusting the position of the nut on the adjusting screw 21 .

[0104] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A hydraulic load-sensing proportional valve for a vehicle, characterized in that: include: A housing (1), wherein the housing (1) comprises a front chamber (1a) and a rear chamber (1b) that are communicated with each other; A front piston (8), a front piston elastic member (2), a one-way valve elastic member (6) and a one-way valve ball (7); the front piston (8) is movably arranged in the front chamber (1a); the front chamber (1a), the side wall of the front piston (8) away from the rear chamber (1b), and the input port on the housing (1) together form a closed input chamber (A); the front piston (8) is arranged in the front chamber (1a) through the front piston elastic member (2), and the front piston elastic member (2) provides elastic The front piston (8) has a matching channel (28) extending along an axis, and the matching channel (28) forms a valve port (29) on a side away from the rear chamber (1b); the one-way valve ball (7) is arranged in the front chamber (1a) through the one-way valve elastic member (6), and the one-way valve elastic member (6) provides an elastic force for moving the one-way valve ball (7) toward the valve port (29) to seal the valve port (29); and a rear piston (11), a rear piston elastic member (12), an adjusting screw (21), an adjusting screw elastic member (15), a load-sensing elastic member seat (20), and a load-sensing compression elastic member (18); the rear chamber (1b), the rear piston (11) against the side wall of the front chamber (1a), and the output port on the housing (1) together enclose a closed output chamber (B); the rear piston (11) includes a body and a piston column connected in sequence; the piston column passes through the matching channel (28) and can abut against the one-way valve ball (7) to move the one-way valve ball (7) away from the valve port (29); the body abuts against the inner wall of the rear chamber (1b) away from the front chamber (1a) through the rear piston elastic member (12), and the rear piston elastic member (12) provides an elastic force to move the body away from the rear chamber (1b) toward the front chamber (1a); The end of the adjusting screw (21) passes through the rear chamber (1b) to abut against the body of the rear piston (11); one end of the adjusting screw (21) close to the rear piston (11) is arranged on the housing (1) through the adjusting screw elastic member (15), and the adjusting screw elastic member (15) provides elastic force to move the adjusting screw (21) toward the rear piston (11); The other end of the adjusting screw (21) away from the rear piston (11) is connected to the load-sensing elastic member seat (20) through the load-sensing compression elastic member (18); the adjusting screw (21) can movably pass through the load-sensing elastic member seat (20), and the load-sensing compression elastic member (18) provides an elastic force to move the adjusting screw (21) and the load-sensing elastic member seat (20) away from each other; During installation, the hydraulic load-sensing proportional valve is assembled between the vehicle frame and the rear wheel fork according to the design state. When the vehicle load changes, causing the distance between the frame and the rear wheel fork to change, the compression length of the load-sensing compression elastic member (18) in the hydraulic load-sensing proportional valve changes accordingly. The housing (1) and the load-sensing elastic member seat (20) are respectively arranged on the vehicle frame and the rear wheel flat fork; therefore, when the vehicle load changes, the force on the housing (1) increases, causing the adjusting screw (21) to move away from the housing (1) and extend out of the load-sensing elastic member seat (20), thereby reducing the elastic force at the rear piston (11).

2. The vehicle hydraulic load-sensing proportional valve according to claim 1, characterized in that: It also includes an adjusting gasket (17); the load-sensing compression elastic member (18) is arranged between the load-sensing elastic member seat (20) and the adjusting gasket (17); The adjusting washer (17) is movably arranged on the adjusting screw (21) along the axial direction of the adjusting screw (21) to adjust the pre-compression elastic force of the load-sensing compression elastic member (18).

3. The vehicle hydraulic load-sensing proportional valve according to claim 2, characterized in that: Also included is an adjustment member (16); The adjusting member (16) is threadedly connected to the adjusting screw (21) to move away from or closer to the load-sensing elastic member seat (20); The adjusting gasket (17) is arranged on the adjusting member (16).

4. The vehicle hydraulic load-sensing proportional valve according to claim 1, characterized in that: It also includes a limit pin (26), wherein the limit pin (26) is arranged on a side of the rear chamber (1b) away from the output chamber (B); A waist-shaped hole (27) is provided on the body of the rear piston (11), and the limiting pin (26) passes through the waist-shaped hole (27).

5. The vehicle hydraulic load-sensing proportional valve according to claim 4, characterized in that: The surface of the shell (1) is provided with a matching hole that at least penetrates to the rear chamber (1b), and one end of the limiting pin (26) passes through the matching hole and is inserted into the waist-shaped hole (27).

6. The vehicle hydraulic load-sensing proportional valve according to claim 5, characterized in that: The side of the limiting pin (26) away from the waist-shaped hole (27) is threadedly connected to the matching hole.

7. The vehicle hydraulic load-sensing proportional valve according to claim 1, characterized in that: Also included is a dust cover (22); The dustproof sleeve (22) is arranged between the load-sensing elastic member seat (20) and the housing (1), and the adjusting screw (21), the adjusting screw elastic member (15) and the load-sensing compression elastic member (18) are all located in the dustproof sleeve (22).

8. The vehicle hydraulic load-sensing proportional valve according to claim 1, characterized in that: It also includes a stopper (14) and an adjusting screw elastic member seat (24); The adjusting screw elastic member seat (24) is arranged on a side of the housing (1) away from the front chamber (1a) and the rear chamber (1b), and the adjusting screw elastic member seat (24) and the housing (1) are enclosed to form an accommodating cavity; the limiter (14) and the adjusting screw elastic member (15) are both located in the accommodating cavity; The adjusting screw (21) passes through the adjusting screw elastic member seat (24); The limiter (14) is fixedly arranged on the adjusting screw (21), and the adjusting screw elastic member (15) is arranged between the inner wall of the adjusting screw elastic member seat (24) and the limiter (14).

9. The vehicle hydraulic load-sensing proportional valve according to claim 8, characterized in that: Also includes an open retaining ring (13); The opening retaining ring (13) is located in the accommodating cavity, and a circumferentially extending slot is provided on the adjusting screw (21), and the opening retaining ring (13) is inserted into the slot; the limiter (14) abuts against a side of the opening retaining ring (13) away from the housing (1).

10. A braking system, characterized in that: The braking system comprises the vehicle hydraulic load-sensing proportional valve according to any one of claims 1 to 9.

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