Anti-slip device for a wheel excavator

Abstract

The application provides an anti-slip device of a wheel excavator, and relates to the technical field of excavator control. The anti-slip device comprises a brake valve and a parking electromagnetic valve. The brake valve has a main brake spool, a first oil inlet, a first oil outlet and a first control end. The main brake spool is used to control the first oil inlet and the first oil outlet to be communicated when the brake pedal transmits a brake signal to the first control end. The parking electromagnetic valve has an auxiliary locking spool, a second oil inlet, a second oil outlet and a second control end. The auxiliary locking spool is used to control the second oil inlet and the second oil outlet to be disconnected when the vehicle controller transmits a parking brake signal to the second control end. The rear axle of the wheel excavator is a wet brake axle, which comprises brake oil chambers and parking oil chambers that are independent of each other. The first oil outlet and the brake oil chambers are communicated, and the second oil outlet and the parking oil chambers are communicated. The application can improve the reliability of the anti-slip effect of the wheel excavator.

Description

Technical Field

[0001] This application relates to the field of excavator control technology, and in particular to an anti-slip device for a wheeled excavator. Background Technology

[0002] When a wheeled excavator releases the brake pedal and depresses the accelerator pedal on a slope, it is prone to slipping due to the force of gravity caused by the slope and the response delay of the hydraulic system. This phenomenon not only threatens the safety of the operator but may also lead to damage to the wheeled excavator or reduced construction efficiency.

[0003] Existing slope protection technology for wheeled excavators uses hardware such as slope angle sensors and speed sensors to monitor the excavator's status in real time. When the excavator is detected to be braking on a slope, the brake pedal depth is increased. A proportional-integral-derivative (PIC) control algorithm calculates the braking force based on the brake pedal depth, and the excavator's built-in brakes further generate the corresponding braking force based on the calculation results, thereby preventing the excavator from sliding down the slope while braking.

[0004] However, existing technologies require additional sensors, and the process of generating braking force is relatively complex, making it difficult to achieve a stable and reliable anti-slip effect. Summary of the Invention

[0005] The anti-slippage device for wheeled excavators provided in this application is used to solve the technical problem that the anti-slippage effect of wheeled excavators in the prior art is unreliable.

[0006] In a first aspect, this application provides an anti-slip device for a wheeled excavator, comprising:

[0007] Brake valve and parking solenoid valve; the brake valve is used to control the service brake of the wheeled excavator, and the parking solenoid valve is used to control the parking brake of the wheeled excavator.

[0008] The brake valve has a first oil inlet, a first oil outlet, and a first control terminal, and a main brake valve core is provided inside the brake valve; the main brake valve core is used to control the first oil inlet and the first oil outlet to connect when the first control terminal receives a brake signal from the brake pedal of the wheeled excavator.

[0009] The parking solenoid valve has a second oil inlet, a second oil outlet, and a second control terminal, and an auxiliary locking valve core is provided inside the parking solenoid valve; the auxiliary locking valve core is used to control the second oil inlet and the second oil outlet to disconnect when the second control terminal receives the parking brake signal from the vehicle controller of the wheeled excavator.

[0010] The rear axle of the wheeled excavator is a wet brake axle. The first oil outlet is connected to the brake fluid chamber in the wet brake axle, and the second oil outlet is connected to the parking fluid chamber in the wet brake axle. The brake fluid chamber and the parking fluid chamber are independent of each other.

[0011] In one possible design, the wet brake axle is coaxially mounted on the tire axle of the wheeled excavator.

[0012] The wet brake axle includes an outer axle housing, and friction pad assembly, brake piston, brake disc spring, brake fluid chamber, parking piston, parking spring, and parking fluid chamber disposed inside the outer axle housing.

[0013] In one possible design, the friction pad assembly is an annular component for generating braking force, and the friction pad assembly is coaxially sleeved on the tire half-shaft.

[0014] The brake piston and the parking piston are both coaxially sleeved on the periphery of the friction plate assembly, and the brake piston and the parking piston are arranged side by side along the axial direction and are independent of each other;

[0015] The brake fluid chamber is coaxially sleeved around the brake piston, and the parking fluid chamber is coaxially sleeved around the parking piston; the brake fluid chamber and the parking fluid chamber are arranged side by side along the axial direction and are independent of each other;

[0016] The outer axle housing is coaxially sleeved around the brake fluid chamber and the parking fluid chamber;

[0017] The brake disc spring is disposed between the brake piston and the outer axle housing, and the parking spring is disposed between the parking piston and the outer axle housing.

[0018] In one possible design, the friction pad assembly includes alternating fixed and rotating pads;

[0019] The fixed plate is connected to the outer axle housing via a first spline, and the rotating plate is connected to the tire half-shaft via a second spline.

[0020] In one possible design, the first oil inlet is connected to an accumulator of the wheeled excavator; the accumulator is mounted on the frame of the wheeled excavator and is used to store hydraulic oil and maintain high pressure.

[0021] The first oil outlet is connected to the first oil inlet and outlet of the brake oil chamber in the wet brake axle. The first oil inlet and outlet are used for the entry and exit of hydraulic oil in the brake oil chamber.

[0022] The first control terminal is connected to the brake pedal of the wheeled excavator.

[0023] In one possible design, the accumulator includes a third oil inlet and a third oil outlet. The third oil inlet passes sequentially through a brake filling valve and a gear pump, and is connected to the oil tank of the wheeled excavator. The third oil outlet is connected to the first oil inlet.

[0024] The brake filling valve is used to fill the accumulator with fluid when the pressure of the accumulator is less than a preset threshold, and to stop filling the accumulator with fluid when the pressure of the accumulator is greater than or equal to the preset threshold.

[0025] The gear pump, driven by the engine of the wheeled excavator, is used to draw hydraulic oil from the oil tank.

[0026] In one possible design, the gear pump includes a fourth oil inlet and a fourth oil outlet, and the brake filling valve includes a fifth oil inlet and a fifth oil outlet.

[0027] The oil tank is connected to the fourth oil inlet, the fourth oil outlet is connected to the fifth oil inlet, and the fifth oil outlet is connected to the third oil inlet.

[0028] In one possible design, the second oil inlet is connected to the third oil outlet via a pressure reducing valve, which is used to reduce the high pressure of the accumulator to the low pressure required for parking brake.

[0029] The second oil outlet is connected to the second oil inlet and outlet of the parking oil chamber in the wet brake axle. The second oil inlet and outlet are used for the entry and exit of hydraulic oil in the parking oil chamber.

[0030] The second control terminal is communicatively connected to the vehicle controller of the wheeled excavator.

[0031] In one possible design, the anti-slip device further includes a proportional pilot solenoid valve and a travel solenoid valve; the proportional pilot solenoid valve includes a forward pilot solenoid valve and a reverse pilot solenoid valve, the forward pilot solenoid valve having a sixth oil inlet, a sixth oil outlet and a third control terminal, and the reverse pilot solenoid valve having a seventh oil inlet, a seventh oil outlet and a fourth control terminal; the travel solenoid valve has a pilot port;

[0032] The third control terminal and the fourth control terminal are communicatively connected to the vehicle controller of the wheeled excavator, and the vehicle controller is electrically connected to the throttle pedal of the wheeled excavator.

[0033] The sixth oil inlet and the seventh oil inlet are both connected to the pressure reducing valve, and the sixth oil outlet and the seventh oil outlet are both connected to the pilot port.

[0034] The proportional pilot solenoid valve is used to output a pilot pressure that is proportional to the driving signal when the vehicle controller receives the driving signal from the accelerator pedal; the pilot pressure acts on the pilot port of the travel solenoid valve.

[0035] The solenoid valve is used to control the flow rate and direction of hydraulic oil flowing into and out of the travel motor of the wheeled excavator according to the pilot pressure.

[0036] Secondly, embodiments of this application provide a wheeled excavator, including: an anti-slip device for the wheeled excavator as described in the first aspect above and various possible designs.

[0037] The anti-slip device for a wheeled excavator provided in this application includes a brake valve for service braking and a parking solenoid valve for parking braking. The brake valve has a first inlet, a first outlet, and a first control terminal, and a main brake valve core is internally disposed therein. This main brake valve core is used to control the connection between the first inlet and the first outlet when the first control terminal receives a brake braking signal from the wheeled excavator's brake pedal. The parking solenoid valve has a second inlet, a second outlet, and a second control terminal, and an auxiliary locking valve core is internally disposed therein. This auxiliary locking valve core is used to control the disconnection of the second inlet and the second outlet when the second control terminal receives a parking brake signal from the wheeled excavator's vehicle controller. Furthermore, the rear axle of the wheeled excavator is a wet brake axle; the first outlet is connected to the brake fluid chamber in the wet brake axle, and the second outlet is connected to the parking fluid chamber in the wet brake axle, but the brake fluid chamber and the parking fluid chamber are independent of each other. The independent brake fluid chambers and parking fluid chambers within the wet brake axle form a separate hydraulic control structure, preventing crosstalk between the service brake and parking brake. Therefore, when parking on a slope, the service brake can be used for timely deceleration, while the parking brake maintains rear axle lock. This facilitates a clearer braking control relationship, providing a foundation for improving the stability and reliability of slope anti-slip control. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0039] Figure 1 A cross-sectional view of the wet brake axle of the anti-slip device for a wheeled excavator provided in an embodiment of this application;

[0040] Figure 2 A schematic diagram of the hydraulic oil flow path of the anti-slip device for a wheeled excavator provided in an embodiment of this application;

[0041] Figure 3A partial structural schematic diagram of the parking brake system of the anti-slip device for a wheeled excavator provided in an embodiment of this application;

[0042] Figure 4 A schematic diagram of the driving principle of the anti-slip device for a wheeled excavator provided in an embodiment of this application;

[0043] Figure 5 A flowchart illustrating the trolley drive process of the anti-slip device for a wheeled excavator provided in an embodiment of this application;

[0044] Figure 6 A schematic diagram of the structure of a wheeled excavator with an anti-slip device provided in an embodiment of this application;

[0045] Figure 7 This is a schematic diagram of a scenario for an anti-slip device for a wheeled excavator provided in an embodiment of this application.

[0046] Figure label:

[0047] 11-Brake valve; 12-Parking solenoid valve; 13-Proportional pilot solenoid valve; 131-Forward pilot solenoid valve; 132-Reverse pilot solenoid valve; 14-Travel solenoid valve; 15-Tire half-shaft; 16-Friction pad assembly; 17-Brake piston; 18-Brake disc spring; 19-Brake fluid chamber; 20-Parking piston; 21-Parking spring; 22-Parking fluid chamber; 23-Accumulator; 24-Brake filling valve; 25-Gear pump; 26-Pilot fuel supply valve; 27-Check valve; 28-Pressure reducing valve; 29-Travel motor; 30-Transmission; 31-Steering mechanism; 32-Rotating shaft; 33-Universal joint; 34-Differential.

[0048] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0049] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0050] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0051] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0052] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with relevant laws, regulations and standards, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0053] Wheeled excavators are a type of engineering machinery widely used in complex terrain environments such as construction sites, mining, and road construction. Their core functions include excavation, loading, and transportation. Especially when operating on slopes, extremely high demands are placed on the stability and safety of wheeled excavators.

[0054] In slope operation scenarios, wheeled excavators typically need to frequently start, stop, and turn. For example, when a wheeled excavator depresses the brake pedal and engages the handbrake on a slope, it is prone to rolling backward due to the gravity of the slope and the response delay of the hydraulic system; that is, the wheeled excavator rolls backward before fully establishing braking force.

[0055] This slippage phenomenon not only threatens the safety of operators but can also damage wheeled excavators or reduce construction efficiency. Therefore, it is essential to design anti-slippage features for wheeled excavators.

[0056] Existing slope protection technology for wheeled excavators uses hardware such as slope angle sensors and speed sensors to monitor the excavator's status in real time. When the excavator is detected to be braking on a slope, the brake pedal depth is increased. A proportional-integral-derivative (PIC) control algorithm calculates the braking force based on the brake pedal depth, and the excavator's built-in brakes further generate the corresponding braking force based on the calculation results, thereby preventing the excavator from sliding down the slope while braking.

[0057] Existing technologies often rely on a large amount of sensor information and multi-stage linkage control. On the one hand, additional sensors are needed to identify the slope status, the motion status of the wheeled excavator, and the braking status. On the other hand, the proportional-integral-derivative control algorithm and the response timing of the brake must also be taken into account.

[0058] Because hydraulic systems inherently have pressure build-up and release lag, a brief gap can easily form between pressing the brake pedal and generating driving force, causing the wheeled excavator to roll backward. Meanwhile, adding extra sensors complicates the system structure, increasing assembly and maintenance costs and the number of potential failure points. If relevant sensor information drifts, is delayed, or becomes abnormal, it can lead to insufficient braking accuracy and unstable parking.

[0059] Therefore, existing technologies are insufficient to achieve stable and reliable slope protection.

[0060] Starting from the limitations of existing technology, the inventors first analyzed the root cause of wheeled excavators slipping on slopes: the hydraulic paths of the braking force generated by the brake pedal and the parking brake generated by the brake system are coupled. Based on this, the inventors designed independent brake and parking oil chambers, and relied on the main brake valve core built into the wheeled excavator's own brake valve and the auxiliary lock-up valve core built into the parking solenoid valve to enable the braking and parking brake to be executed independently, thereby improving the reliability of the wheeled excavator's anti-slip-off effect.

[0061] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0062] This application provides an anti-slip device for a wheeled excavator. The anti-slip device for the wheeled excavator includes: a brake valve 11, a parking solenoid valve 12, a proportional pilot solenoid valve 13, and a travel solenoid valve 14.

[0063] The brake valve 11 controls the service brake of the wheeled excavator. Specifically, it converts the driver's braking operation into pressure control of the wheeled excavator's service brake circuit, thus maintaining stability when the excavator is working on a slope or during brief stops. The parking solenoid valve 12 controls the parking brake of the wheeled excavator. Specifically, when the wheeled excavator is parked on a slope, its parking brake circuit is independently controlled to prevent the excavator from rolling backward due to pressure decay after the service brake is released.

[0064] The proportional pilot solenoid valve 13 is a control valve assembly that converts electrical signals into proportional hydraulic pilot pressure. It is used to convert the driver's driving intention into a continuously adjustable pilot control quantity, thereby avoiding abrupt responses during vehicle start-up. The travel solenoid valve 14 is used to change the oil inlet and return channels of the travel motor under the action of pilot pressure, realizing the forward, reverse, and speed regulation of the wheeled excavator.

[0065] It should be understood that the final implementers of the anti-slip function are the front and rear axles of the wheeled excavator. It should be noted that, for the wheeled excavator in this embodiment, the front axle is only connected to the travel (brake) circuit, while the rear axle is connected to both the travel brake circuit and the parking brake circuit.

[0066] Next, we will provide a detailed description of each component involved in the coordinated work of preventing landslides.

[0067] For the front axle of a wheeled excavator, since it only connects to the service brake circuit, a standard dry brake axle is sufficient. However, for the rear axle of a wheeled excavator, a wet brake axle is typically used to achieve dual circuit connection for both the service brake and parking brake.

[0068] Explained, a wet brake axle is a housing-type brake assembly used to carry and transmit braking torque. It is defined as an assembly arranged coaxially with the tire half-shaft 15, allowing the braking function to act directly on the tire half-shaft 15 and further transmit it to the wheels, thereby integrating service braking and parking braking.

[0069] Detailed Figure 1 A cross-sectional view of the wet brake axle of the anti-slip device for a wheeled excavator provided in this application embodiment, as shown below. Figure 1 As shown, the wet brake axle is coaxially mounted on the tire half-shaft 15. The wet brake axle includes an outer axle housing, and friction pad assembly 16, brake piston 17, brake disc spring 18, brake oil chamber 19, parking piston 20, parking spring 21 and parking oil chamber 22 disposed inside the outer axle housing.

[0070] In terms of structural form, the outer axle housing can be an integral cast housing, a split housing, or a welded assembly housing. Materials can include ductile iron, high-strength cast steel, or high-strength aluminum alloy to balance strength, rigidity, and heat dissipation. The friction plate assembly 16 can be formed by alternating arrangements of multiple fixed and rotating plates. The materials for the fixed and rotating plates can be sintered metal matrix composites, paper-based friction materials, or carbon-based friction materials. The brake piston 17 and parking piston 20 can be annular pistons, cup-shaped pistons, or stepped pistons. Materials can include chrome-plated steel parts, aluminum alloy parts, or composite wear-resistant materials. The brake disc spring 18 and parking spring 21 can be disc springs, wave springs, or helical compression springs. Materials can include spring steel, stainless spring steel, or alloy spring steel. It should be understood that the above structural forms and material selections are merely illustrative and not limiting. Any structure that can achieve an equivalent structure forming independent service brake and parking brake cavities within the outer axle housing should fall within the protection scope of this application.

[0071] In terms of connection and fit, the friction pad assembly 16, used to generate braking force, is coaxially sleeved on the tire half-shaft 15. The brake piston 17 and parking piston 20 are both coaxially sleeved around the friction pad assembly 16, and are arranged side-by-side axially and independently. The brake fluid chamber 19 is coaxially sleeved around the brake piston 17, and the parking fluid chamber 22 is coaxially sleeved around the parking piston 20. The brake fluid chamber 19 and parking fluid chamber 22 are arranged side-by-side axially and independently; a partition, sealing ring, or independent wall is typically provided between them to prevent fluid cross-contamination or pressure interference. The outer axle housing is coaxially sleeved around the brake fluid chamber 19 and parking fluid chamber 22.

[0072] As can be seen, the wet brake axle exhibits a coaxial nesting relationship from the inside out. In this coaxial nesting relationship, the first layer is the friction pad assembly 16, the second layer is the brake piston 17 and the parking piston 20, the third layer is the brake fluid chamber 19 and the parking fluid chamber 22, and the outermost layer is the outer axle housing. It should be noted that the brake disc spring 18 is located between the brake piston 17 and the outer axle housing, and the parking spring 21 is located between the parking piston 20 and the outer axle housing.

[0073] Functionally, the friction pad assembly 16 converts the axial force applied by the brake piston 17 or parking piston 20 into normal pressure between the friction pads, and further into a resisting torque on the rotation of the tire half-shaft 15. The brake piston 17 functions to act quickly upon receiving pressure from the brake fluid chamber 19 to establish and release the service brake. The parking piston 20 functions to achieve a more stable locking and clamping action upon receiving pressure from the parking fluid chamber 22, ensuring that the wheeled excavator does not roll backward when parked on a slope.

[0074] The brake valve 11 has a first control end and a main brake valve core inside. The main brake valve core is arranged axially along the valve cavity of the brake valve 11 and works in conjunction with the return spring, the sealing ring, the limiting part, and the flow channel inside the valve body.

[0075] The first control terminal is connected to the brake pedal of the wheeled excavator via a transmission connection, which can be a mechanical linkage, a hydraulic pilot, or an electrical signal conversion type. Explained, the first control terminal is connected to the force-receiving end of the main brake valve core, used to convert the driver's pedal displacement, pedal force, or pedal switching quantity into control input to the main brake valve core, enabling the service brake to be applied or released according to the operator's intention.

[0076] The brake valve 11 also has a first oil inlet and a first oil outlet. The first oil outlet communicates with the first oil inlet / outlet of the brake fluid chamber 19, and is used to control the entry and exit of hydraulic oil within the brake fluid chamber. Illustratively, the oil inlet and outlet of the brake fluid chamber 19 are the same port, namely the first oil inlet / outlet. The hydraulic oil in the brake fluid chamber 19 comes from an accumulator 23 that communicates with the first oil inlet. This accumulator 23 is mounted on the frame of the wheeled excavator and is used to store the hydraulic oil in a high-pressure form.

[0077] When the driver presses the brake pedal, the brake pedal generates a braking signal and transmits it to the first control terminal. After receiving the braking signal, the first control terminal controls the first oil inlet and the first oil outlet to connect, and the accumulator 23 instantly releases the stored high-pressure hydraulic oil into the brake fluid chamber 19.

[0078] Illustratively, the final source of the hydraulic oil in accumulator 23 is the wheeled excavator's oil tank. It should be understood that the oil tank is the "headquarters" of the entire machine's hydraulic oil, storing all the hydraulic oil in the wheeled excavator.

[0079] In this embodiment, the accumulator 23 includes a third oil inlet and a third oil outlet. Figure 2 This is a schematic diagram of the hydraulic oil flow path of the anti-slip device for a wheeled excavator provided in the embodiments of this application, as shown below. Figure 2 As shown, the third oil outlet is connected to the first oil inlet, which in turn passes through the brake filling valve 24 and the gear pump 25 before connecting to the oil tank. The gear pump 25 is driven by the engine and is used to draw hydraulic oil from the oil tank.

[0080] Understandably, the third inlet and the third outlet can be located at different ends or sides of the accumulator housing to facilitate piping layout and assembly. Furthermore, in actual installations, the third inlet and the third outlet are typically connected to the external hydraulic circuit via high-pressure hoses, rigid pipe fittings, or flange fittings.

[0081] In detail, the gear pump 25 includes a fourth oil inlet and a fourth oil outlet, and the brake filling valve 24 includes a fifth oil inlet and a fifth oil outlet. The oil tank is connected to the fourth oil inlet, the fourth oil outlet is connected to the fifth oil inlet, and the fifth oil outlet is connected to the third oil inlet.

[0082] Thus, the gear pump 25 can continuously draw hydraulic oil from the oil tank through the fourth oil inlet. After the drawn hydraulic oil is output from the fourth oil outlet, it is introduced into the brake filling valve 24 through the fifth oil inlet. The fifth oil inlet is connected to the third oil inlet, so that the hydraulic oil regulated by the brake filling valve 24 flows further into the accumulator 23 to complete the replenishment.

[0083] Explaining this, the function of the brake fluid filling valve 24 is to replenish hydraulic oil to the accumulator 23 when the pressure of the accumulator 23 is less than a preset threshold, and to stop filling the accumulator 23 when the pressure of the accumulator 23 is greater than or equal to the preset threshold.

[0084] In this embodiment, the accumulator 23 can be filled with fluid via the path of "oil tank → gear pump 25 → brake filling valve 24 → accumulator 23". However, when the pressure of the accumulator 23 is greater than or equal to a preset threshold, the hydraulic oil output by the gear pump 25 has nowhere to go and can only flow back to the oil tank.

[0085] Therefore, to avoid the gear pump 25 performing useless work when the accumulator 23 is not filled with fluid, in one possible implementation, a pilot oil supply valve 26 can be installed between the gear pump 25 and the brake filling valve 24 to form a priority oil supply system. That is, when the pressure of the accumulator 23 is less than a preset threshold, the pilot oil supply valve 26 prioritizes supplying all or most of the hydraulic oil from the gear pump 25 to the brake filling valve 24 to fill the accumulator 23. When the pressure of the accumulator 23 reaches the preset threshold, the brake filling valve 24 cuts off the oil passage to the accumulator 23. At this time, the pilot oil supply valve 26 automatically switches all the hydraulic oil from the gear pump 25 to other systems that require oil supply, such as the cooling system. It should be understood that the above implementation is only illustrative and not limiting.

[0086] In another possible implementation, when the pressure of the accumulator 23 reaches a preset threshold, in order to prevent the hydraulic oil in the accumulator 23 from flowing back to the brake filling valve 24, a one-way valve 27 can be provided between the brake filling valve 24 and the accumulator 23. Since some brake filling valves 24 have a built-in check function, it means that it is not necessary to provide a one-way valve 27. Therefore, this embodiment does not specifically limit whether to provide a one-way valve 27.

[0087] In summary, the "oil tank → gear pump 25 → brake filling valve 24 → accumulator 23 → brake valve 11 → brake oil chamber 19 → brake piston 17 → brake disc spring 18" together constitute the service braking system of the wheeled excavator in this embodiment.

[0088] In practice, after the wheeled excavator starts, the engine drives the gear pump 25 to rotate synchronously. The gear pump 25 draws hydraulic oil from the oil tank and establishes oil supply pressure at the outlet side (fourth oil outlet). The hydraulic oil enters the third oil inlet of the accumulator 23 through the brake filling valve 24, replenishing the fluid and increasing the pressure inside the accumulator 23.

[0089] Subsequently, when the driver stops on the slope, they depress the brake pedal. The brake signal from the brake pedal is transmitted through the transmission mechanism to the first control end, causing the main brake valve core to move within the valve body of the brake valve 11 and establishing a connection between the first oil inlet and the first oil outlet. The high-pressure hydraulic oil in the accumulator 23 then flows into the brake oil chamber 19 through the first oil outlet. After the hydraulic oil flows into the brake oil chamber 19, the brake oil chamber 19 pushes the brake piston 17, causing the brake piston 17 to press against the friction plate assembly 16 to generate braking force, thereby achieving the service braking of the wheeled excavator. It is worth noting that during the process of the brake oil chamber 19 pushing the brake piston 17, the brake disc spring 18 is compressed as the brake oil chamber 19 moves.

[0090] Explained, the fixed plate in the friction plate assembly 16 is connected to the outer axle housing via a first spline, forming a relatively static connection between the fixed plate and the outer axle housing. The rotating plate in the friction plate assembly 16 is connected to the tire half-shaft 15 via a second spline and rotates synchronously with the tire half-shaft 15. When the brake piston 17 presses against the friction plate assembly 16, the relative slippage between the fixed plate and the rotating plate is quickly suppressed, the torque borne by the rotating plate is transmitted to the fixed plate, and ultimately borne by the outer axle housing, thereby achieving braking of the tire half-shaft 15.

[0091] When the driver releases the brake pedal, the force at the first control end is released, and the main brake valve core returns to its initial position under the action of the reset spring or oil pressure balance. The hydraulic oil in the brake oil chamber 19 flows back to the oil tank through the return port, and the service brake is released.

[0092] Since the wheeled excavator is parked on a slope, if the operator releases the brake pedal directly, thus disengaging the service brake, the excavator will inevitably roll back down the slope. Therefore, the parking brake should be engaged before releasing the service brake.

[0093] To activate the parking brake, the parking solenoid valve 12, included in the anti-slip device of the wheeled excavator in this embodiment, is required. In this embodiment, the parking solenoid valve 12 has a second control terminal and an auxiliary locking valve core is internally provided. The second control terminal is communicatively connected to the vehicle controller of the wheeled excavator. The vehicle controller can output a parking brake signal to the second control terminal according to the driver's operation and the working condition of the wheeled excavator, thereby causing the wheeled excavator to enter the parking brake process.

[0094] The parking solenoid valve 12 also has a second oil inlet and a second oil outlet. The second oil outlet is connected to the second oil inlet / outlet of the parking oil chamber 22, and is used to control the entry and exit of hydraulic oil within the parking oil chamber 22. For illustrative purposes, the oil inlet and outlet of the parking oil chamber 22 are the same port, namely the second oil inlet / outlet.

[0095] It is worth noting that the parking hydraulic chamber 22 and the brake hydraulic chamber 19 are logically completely opposite. The presence of hydraulic oil in the parking hydraulic chamber 22 means that the parking brake is not engaged, while the absence of hydraulic oil in the parking hydraulic chamber 22 means that the parking brake is engaged.

[0096] When the parking brake is not engaged, the hydraulic oil in the parking oil chamber 22 originates from the same source as the hydraulic oil in the brake oil chamber 19: the accumulator 23. However, Figure 3 This is a partial structural diagram of the parking brake system of the anti-slip device for a wheeled excavator provided in an embodiment of this application, as shown below. Figure 3 As shown, the second oil inlet of the parking solenoid valve 12 needs to be connected to the third oil outlet of the accumulator 23 through the pressure reducing valve 28.

[0097] This is because the hydraulic oil required for the parking oil chamber 22 is usually low-pressure hydraulic oil, while the accumulator 23 provides high-pressure hydraulic oil. Therefore, a pressure reducing valve 28 needs to be installed between the accumulator 23 and the parking solenoid valve 12. This pressure reducing valve 28 is used to reduce the high-pressure hydraulic oil in the accumulator 23 to the low-pressure hydraulic oil required for the parking oil chamber 22.

[0098] Considering that the accumulator 23 is mainly used for supplying oil to the service brake and that its capacity is limited, in one possible implementation, the second oil inlet of the parking solenoid valve 12 is connected to the pilot oil supply valve 26 via the pressure reducing valve 28. This allows for continuous oil supply from the gear pump 25, avoiding the depletion of the energy stored in the accumulator 23. This implementation is only intended to provide a possibility, and the specific connection relationship of the parking solenoid valve 12 is not limited here.

[0099] Thus, the vehicle controller outputs a parking brake signal to the second control terminal based on the driver's operation and the working conditions of the wheeled excavator. Upon receiving the parking brake signal at the second control terminal, the auxiliary lock-up valve core controls the second oil inlet and the second oil outlet to disconnect, thereby quickly releasing the hydraulic oil in the parking oil chamber 22 and executing the parking brake.

[0100] In this embodiment, the "oil tank → gear pump 25 → brake fluid filling valve 24 → accumulator 23 → pressure reducing valve 28 → parking solenoid valve 12 → parking oil chamber 22 → parking spring 21 → parking piston 20" together constitute the parking brake system of the wheeled excavator in this embodiment. It should be understood that the oil tank, gear pump 25, brake fluid filling valve 24, and accumulator 23 are shared components for both the brake braking and parking brake systems.

[0101] In practical implementation, the parking brake signal from the vehicle controller acts on the second control terminal, at which point the parking solenoid valve 12 is de-energized. The auxiliary locking valve core moves under the force of the spring inside the parking solenoid valve 12, mechanically cutting off the second oil inlet and outlet, allowing the hydraulic oil in the parking oil chamber 22 to be rapidly released. After the hydraulic oil is completely released, the parking spring 21 rebounds from its hydraulically compressed state, returning to its natural length. At this time, the elastic force of the parking spring 21 is entirely used to push the parking piston 20 to press against the friction plate assembly 16, thereby achieving the parking brake of the wheeled excavator.

[0102] Understandably, after applying the parking brake and then releasing the brake, although the brake piston 17 no longer presses against the friction plate assembly 16, the parking piston 20 still presses against the friction plate assembly 16, thus preventing the wheeled excavator from slipping. Furthermore, since the brake oil chamber 19 and the parking oil chamber 22 are independent of each other, there is no crosstalk between the brake and parking brakes, eliminating the need to wait for the brake to be released before applying the parking brake, thereby improving the stability and reliability of the slope anti-slip control.

[0103] When the wheeled excavator is in parking brake mode, if the operator wants to drive the excavator, they must first release the parking brake by operating an operation such as pressing the handbrake release button or shifting into D gear. At this time, the parking solenoid valve 12 is energized, hydraulic oil flows into the parking oil chamber 22, the parking spring 21 is compressed, and the parking piston 20 no longer presses against the friction plate assembly 16.

[0104] After releasing the parking brake, the wheeled excavator is put into traction drive. Illustratively, the traction drive of the wheeled excavator relies on proportional pilot solenoid valve 13 and travel solenoid valve 14.

[0105] Detailed Figure 4 The schematic diagram of the trolley drive principle of the anti-slip device for a wheeled excavator provided in the embodiments of this application is as follows: Figure 4As shown, the proportional pilot solenoid valve 13 includes a forward pilot solenoid valve 131 and a reverse pilot solenoid valve 132. The forward pilot solenoid valve 131 has a third control terminal, and the reverse pilot solenoid valve 132 has a fourth control terminal.

[0106] Both the third and fourth control terminals are communicatively connected to the vehicle controller, which in turn is electrically connected to the throttle pedal of the wheeled excavator. In one possible implementation, the vehicle controller can also be electrically connected to a cruise control switch installed in the wheeled excavator to enable cruise control functionality.

[0107] When the driver presses the accelerator pedal, the accelerator pedal generates a corresponding driving signal, which is transmitted to the vehicle controller. After the vehicle controller receives the driving signal, the proportional pilot solenoid valve 13 outputs a pilot pressure that is proportional to the driving signal.

[0108] It is worth noting that the driving drive signal includes the driving direction, i.e., forward or reverse. If it is a driving drive signal indicating forward movement, the forward pilot solenoid valve 131 is responsible for generating pilot pressure. Conversely, if it is a driving drive signal indicating reverse movement, the reverse pilot solenoid valve 132 is responsible for generating pilot pressure.

[0109] It should be noted that the pilot pressure generated by the forward pilot solenoid valve 131 / reverse pilot solenoid valve 132 acts on the pilot port of the travel solenoid valve 14. Based on this pilot pressure, the travel solenoid valve 14 controls the flow rate and direction of hydraulic oil entering and exiting the travel motor 29 of the wheeled excavator. The pilot pressure is essentially the pressure of the hydraulic oil. The pilot pressure enters the pilot chamber of the travel solenoid valve 14 and then acts on the valve core, pushing the valve core to move.

[0110] In this embodiment, the hydraulic oil used to generate the pilot pressure comes from the accumulator 23. Specifically, the forward pilot solenoid valve 131 also has a sixth inlet and a sixth outlet, and the reverse pilot solenoid valve 132 also has a seventh inlet and a seventh outlet. Both the sixth and seventh inlets are connected to the pressure reducing valve 28. The travel solenoid valve 14 has a pilot port, to which both the sixth and seventh outlets are connected.

[0111] As can be seen, the high-pressure hydraulic oil in the accumulator 23 flows through the pressure reducing valve 28 and then into the forward pilot solenoid valve 131 / reverse pilot solenoid valve 132 in the form of low-pressure hydraulic oil, and then flows into the travel solenoid valve 14.

[0112] In addition, the travel solenoid valve 14 has an eighth oil inlet, an eighth oil outlet, and a ninth oil outlet, and the travel motor 29 has a first oil port and a second oil port. The eighth oil inlet is connected to the hydraulic pump of the wheeled excavator, the eighth oil outlet is connected to the first oil port, and the ninth oil outlet is connected to the second oil port.

[0113] Explaining this further, for the first and second oil ports of the travel motor 29, when oil is entering through one port, the other port is used for oil return, thereby enabling the travel motor 29 to rotate forward or reverse, and thus controlling the wheeled excavator to move forward or backward. For example, when oil is entering through the first port and returning through the second port, the travel motor 29 rotates forward, and the wheeled excavator moves forward. When oil is entering through the second port and returning through the first port, the travel motor 29 rotates in reverse, and the wheeled excavator moves backward.

[0114] Explanatory Figure 5 The vehicular drive flowchart of the anti-slip device for a wheeled excavator provided in the embodiments of this application is as follows: Figure 5 As shown, the specific driving process of a wheeled excavator is as follows:

[0115] S11. When the wheeled excavator is in gear and out of gear, set the mapping relationship between the throttle opening and the pilot pressure output by the proportional pilot solenoid valve for different states.

[0116] It should be understood that these mapping relationships will be integrated into a single table and stored.

[0117] S12. Using the current throttle opening of the wheeled excavator as input, calculate the target pilot pressure that the proportional pilot solenoid valve should output at present by looking up a table and linear interpolation.

[0118] Explained, a proportional pilot solenoid valve contains a proportional electromagnet. The vehicle controller, based on the received driving signal, outputs a variable current to the proportional electromagnet. This current generates an electromagnetic force on the electromagnet, which pushes the valve core of the proportional pilot solenoid valve, thereby outputting a target pilot pressure proportional to the variable current.

[0119] S13. By using the proportional-integral-derivative control algorithm built into the wheeled excavator, adjust the proportional pilot solenoid valve so that its actual output pilot pressure is the target pilot pressure.

[0120] S14. The target pilot pressure acts on the travel solenoid valve, which controls the travel motor to rotate, thus driving the wheeled excavator to travel.

[0121] It should be noted that, Figure 6 A schematic diagram of the structure of a wheeled excavator with an anti-slip device provided in an embodiment of this application is shown below. Figure 6As shown, the wheeled excavator's frame houses a travel drive assembly, which includes a transmission 30 and a travel motor 29. Additionally, the frame also includes a steering mechanism 31, a drive shaft 32, and multiple universal joints 33. Differentials 34 are installed on the corresponding wheel axles 15 of both the front and rear axles. Since the travel motor 29, transmission 30, steering mechanism 31, drive shaft 32, universal joints 33, and differentials 34 are common components applicable to various vehicles, they will not be described in detail here.

[0122] It should be understood that through the joint cooperation of the proportional pilot solenoid valve 13 and the travel solenoid valve 14, driving force can be established before the parking brake is released, thereby avoiding the wheeled excavator from slipping downhill due to insufficient driving force when the parking brake is released.

[0123] In one possible implementation, the brake valve 11, parking solenoid valve 12, proportional pilot solenoid valve 13, travel solenoid valve 14, brake filling valve 24, and pressure reducing valve 28 in this embodiment are all integrated into the same hydraulic valve group, and the integrated hydraulic valve group is installed on the frame of the wheeled excavator.

[0124] In addition, this embodiment also designs corresponding safe driving strategies for different driving scenarios of wheeled excavators. Figure 7 This is a schematic diagram of a scenario for an anti-slip device for a wheeled excavator provided in an embodiment of this application, as shown below. Figure 7 As shown, the safe driving strategy designed in this embodiment includes, but is not limited to: (1) When the pilot lock of the wheeled excavator is opened or the parking (P) gear is activated, the parking solenoid valve is de-energized. (2) When the pressure of the brake pedal is greater than the preset pressure threshold (e.g., 36 bar) and the duration of the pressure reaches the preset duration (e.g., 1 s), the parking solenoid valve is de-energized. This safe driving strategy is not executed when the brake pedal fails. (3) When the current controlling the opening of the travel solenoid valve is greater than the preset current threshold (e.g., 600 mA), the parking solenoid valve is energized. (4) When the pilot lock is closed and the parking (P) gear is not activated, if the parking solenoid valve is de-energized, the parking solenoid valve is opened after the brake pedal is released for a certain period of time (e.g., 3 s).

[0125] The anti-slip device for a wheeled excavator provided in this application includes a brake valve for service braking and a parking solenoid valve for parking braking. The rear axle of the wheeled excavator is a wet brake axle, including independent brake fluid chambers and parking fluid chambers. The brake valve has a first inlet, a first outlet, and a first control terminal, and a main brake valve core is installed inside the brake valve. The first inlet is connected to the accumulator of the wheeled excavator, and the first outlet is connected to the first inlet and outlet of the brake fluid chamber. The first inlet and outlet are used for the entry and exit of hydraulic oil in the brake fluid chamber, and the first control terminal is kinetically connected to the brake pedal. The main brake valve core is used to control the connection between the first inlet and the first outlet when the first control terminal receives a brake signal from the brake pedal of the wheeled excavator. The parking solenoid valve has a second inlet, a second outlet, and a second control terminal, and an auxiliary lock-up valve core is installed inside the parking solenoid valve. The second oil inlet is connected to the accumulator via a pressure reducing valve, which reduces the high pressure of the accumulator to the low pressure required for parking brake operation. The second oil outlet is connected to the second inlet / outlet of the parking oil chamber, allowing hydraulic oil to enter and exit the chamber. The second control terminal is connected to the vehicle controller. An auxiliary locking valve core, upon receiving a parking brake signal from the wheeled excavator's vehicle controller at the second control terminal, controls the second oil inlet and outlet to disconnect. The independent brake and parking oil chambers within the wet brake axle form a separate hydraulic control structure, preventing crosstalk between the service brake and parking brake. Therefore, when parking on a slope, the service brake can be used for timely deceleration, while the parking brake maintains rear axle locking, resulting in a clearer braking control relationship and providing a foundation for improving the stability and reliability of slope anti-slip control.

[0126] This application also provides a wheeled excavator, which includes the anti-slip device of the wheeled excavator provided in the above embodiments.

[0127] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.

[0128] Furthermore, unless otherwise specified, the functional units / modules in the various embodiments of this application can be integrated into one unit / module, or each unit / module can exist physically separately, or two or more units / modules can be integrated together. The integrated units / modules described above can be implemented in hardware or as software program modules.

[0129] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as these combinations of technical features do not contradict each other, they should be considered within the scope of this specification.

[0130] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

Claims

1. A slope-prevention device for a wheeled excavator, characterized in that, include: Brake valve, parking solenoid valve; The brake valve is used to control the service brake of the wheeled excavator, and the parking solenoid valve is used to control the parking brake of the wheeled excavator. The brake valve has a first oil inlet, a first oil outlet, and a first control terminal, and a main brake valve core is provided inside the brake valve; the main brake valve core is used to control the first oil inlet and the first oil outlet to connect when the first control terminal receives a brake signal from the brake pedal of the wheeled excavator. The parking solenoid valve has a second oil inlet, a second oil outlet, and a second control terminal, and an auxiliary locking valve core is provided inside the parking solenoid valve; the auxiliary locking valve core is used to control the second oil inlet and the second oil outlet to disconnect when the second control terminal receives the parking brake signal from the vehicle controller of the wheeled excavator. The rear axle of the wheeled excavator is a wet brake axle. The first oil outlet is connected to the brake fluid chamber in the wet brake axle, and the second oil outlet is connected to the parking fluid chamber in the wet brake axle. The brake fluid chamber and the parking fluid chamber are independent of each other.

2. The anti-slip device for a wheeled excavator according to claim 1, characterized in that, The wet brake axle is coaxially mounted on the tire half-shaft of the wheeled excavator. The wet brake axle includes an outer axle housing, and friction pad assembly, brake piston, brake disc spring, brake fluid chamber, parking piston, parking spring, and parking fluid chamber disposed inside the outer axle housing.

3. The anti-slip device for a wheeled excavator according to claim 2, characterized in that, The friction pad assembly is an annular component used to generate braking force, and the friction pad assembly is coaxially sleeved on the tire half shaft. The brake piston and the parking piston are both coaxially sleeved on the periphery of the friction plate assembly, and the brake piston and the parking piston are arranged side by side along the axial direction and are independent of each other; The brake fluid chamber is coaxially sleeved around the brake piston, and the parking fluid chamber is coaxially sleeved around the parking piston; the brake fluid chamber and the parking fluid chamber are arranged side by side along the axial direction and are independent of each other; The outer axle housing is coaxially sleeved around the brake fluid chamber and the parking fluid chamber; The brake disc spring is disposed between the brake piston and the outer axle housing, and the parking spring is disposed between the parking piston and the outer axle housing.

4. The anti-slip device for a wheeled excavator according to claim 2, characterized in that, The friction plate assembly includes alternating fixed plates and rotating plates; The fixed plate is connected to the outer axle housing via a first spline, and the rotating plate is connected to the tire half-shaft via a second spline.

5. The anti-slip device for a wheeled excavator according to claim 1, characterized in that, The first oil inlet is connected to the accumulator of the wheeled excavator; the accumulator is installed on the frame of the wheeled excavator and is used to store hydraulic oil and maintain high pressure. The first oil outlet is connected to the first oil inlet and outlet of the brake oil chamber in the wet brake axle. The first oil inlet and outlet are used for the entry and exit of hydraulic oil in the brake oil chamber. The first control terminal is connected to the brake pedal of the wheeled excavator.

6. The anti-slip device for a wheeled excavator according to claim 5, characterized in that, The accumulator includes a third oil inlet and a third oil outlet. The third oil inlet passes through a brake filling valve and a gear pump in sequence and is connected to the oil tank of the wheeled excavator. The third oil outlet is connected to the first oil inlet. The brake filling valve is used to fill the accumulator with fluid when the pressure of the accumulator is less than a preset threshold, and to stop filling the accumulator with fluid when the pressure of the accumulator is greater than or equal to the preset threshold. The gear pump, driven by the engine of the wheeled excavator, is used to draw hydraulic oil from the oil tank.

7. The anti-slip device for a wheeled excavator according to claim 6, characterized in that, The gear pump includes a fourth oil inlet and a fourth oil outlet, and the brake filling valve includes a fifth oil inlet and a fifth oil outlet. The oil tank is connected to the fourth oil inlet, the fourth oil outlet is connected to the fifth oil inlet, and the fifth oil outlet is connected to the third oil inlet.

8. The anti-slip device for a wheeled excavator according to claim 6, characterized in that, The second oil inlet is connected to the third oil outlet through a pressure reducing valve, which is used to reduce the high pressure of the accumulator to the low pressure required for parking brake. The second oil outlet is connected to the second oil inlet and outlet of the parking oil chamber in the wet brake axle. The second oil inlet and outlet are used for the entry and exit of hydraulic oil in the parking oil chamber. The second control terminal is communicatively connected to the vehicle controller of the wheeled excavator.

9. The anti-slip device for a wheeled excavator according to claim 8, characterized in that, The anti-slip device also includes a proportional pilot solenoid valve and a traveling solenoid valve; the proportional pilot solenoid valve includes a forward pilot solenoid valve and a reverse pilot solenoid valve, the forward pilot solenoid valve has a sixth oil inlet, a sixth oil outlet and a third control terminal, the reverse pilot solenoid valve has a seventh oil inlet, a seventh oil outlet and a fourth control terminal; the traveling solenoid valve has a pilot port. The third control terminal and the fourth control terminal are communicatively connected to the vehicle controller of the wheeled excavator, and the vehicle controller is electrically connected to the throttle pedal of the wheeled excavator. The sixth oil inlet and the seventh oil inlet are both connected to the pressure reducing valve, and the sixth oil outlet and the seventh oil outlet are both connected to the pilot port. The proportional pilot solenoid valve is used to output a pilot pressure that is proportional to the driving signal when the vehicle controller receives the driving signal from the accelerator pedal; the pilot pressure acts on the pilot port of the travel solenoid valve. The solenoid valve is used to control the flow rate and direction of hydraulic oil flowing into and out of the travel motor of the wheeled excavator according to the pilot pressure.

10. A wheeled excavator, characterized in that, The wheeled excavator includes: an anti-slip device for the wheeled excavator as described in any one of claims 1 to 9.

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