A brake control system and method for a multi-functional excavator implement trailer

Abstract

The application discloses a brake control system and method for a multifunctional excavator accessory trailer, which comprises a conventional double-release valve parking brake system, an electromagnetic proportional valve, a vehicle controller, a walking pressure sensor and a hand brake button; the electromagnetic proportional valve is connected in parallel to the air circuit of the double-release valve parking brake system, the flow and speed of air release of the air circuit of the brake system are controlled by adjusting the valve opening, the air release time is further controlled, and finally the multifunctional excavator and the accessory trailer can keep the actions consistent as far as possible during driving; the vehicle controller is pre-configured with the function relationship among the PWM current of the electromagnetic proportional valve, the total mass of the trailer and the accessories and the walking pressure value, the PWM current of the electromagnetic proportional valve is calculated based on real-time data, and the valve opening is further controlled. By adding the electromagnetic proportional valve, the synchronous braking of the excavator and the accessory trailer during driving is realized by the vehicle controller, the modification cost is low, and the structure is simple and easy to operate.

Description

TECHNICAL FIELD

[0001] The application discloses a brake control system and method of a multifunctional excavator accessory trailer and relates to the technical field of engineering machinery. BACKGROUND

[0002] The multifunctional excavator can complete road obstacle removal, dangerous source removal, cofferdam construction, rescue and other operations by installing various operation accessories such as a bucket, a block-shaped grab bucket, a pile driver, a rock drill, a hydraulic clamp and a milling head. The accessory trailer with a trailing rod can realize storage and transportation of all accessories, auxiliary equipment, tools, spare parts and the like.

[0003] During transportation and transfer, the accessory trailer can be driven by a heavy truck, and the excavator can be transported by a trailer truck, so that the excavator can quickly arrive at a construction or rescue site. After arriving at the site, the excavator drives the accessory trailer.

[0004] Due to limitations of procurement cost, maintenance and resource matching, the accessory trailer is usually designed as a general automobile trailer, and the brake needs to be a pneumatic valve of a towing vehicle brake valve. However, the multifunctional excavator does not have a brake pedal, a parking hand brake, a corresponding pneumatic system and an interface, and the structures and principles of the two brake systems are incompatible. At present, the accessory trailer can manually realize two states of brake opening and brake closing through an additional parking brake system, and the excavator cannot realize synchronous braking when driving the accessory trailer, and can only slowly tow.

[0005] When the multifunctional excavator drives the accessory trailer, especially when the mass of the accessory trailer is too large or the driving surface has a longitudinal slope, the driver cannot synchronously brake the accessory trailer, and accidents such as collision of the accessory trailer with the main vehicle or folding of the main trailer towing rod are prone to occur. In addition, the accessory trailer will have a large impact on the towing hook, the towing ring and the safety pin due to inertia, causing damage to the towing rod assembly and a large safety hazard. SUMMARY

[0006] The application aims to provide a brake control system and method of a multifunctional excavator accessory trailer, which retains the original trailer pneumatic system and manual brake function, adds an electromagnetic proportional valve and realizes synchronous braking of the excavator and the accessory trailer during driving through a vehicle controller.

[0007] To achieve the above object, the application adopts the following technical scheme:

[0008] The application provides a brake control system of a multifunctional excavator accessory trailer, which comprises a double-release-valve parking brake system and further comprises an electromagnetic proportional valve, a vehicle controller, a walking pressure sensor and a hand brake button.

[0009] The electromagnetic proportional valve is connected in parallel to the air circuit of the dual release valve parking brake system.

[0010] Both the walking pressure sensor and the manual brake button are electrically connected to the vehicle controller.

[0011] The walking pressure sensor is installed on the foot valve and is used to detect walking pressure signals;

[0012] The manual brake button is used to send a braking signal to the vehicle controller;

[0013] The vehicle controller is used to obtain the total mass of the attachment trailer, collect the pressure analog signal from the walking pressure sensor, receive the switching braking signal sent by the handbrake button, and calculate the PWM current of the electromagnetic proportional valve and send it to the electromagnetic proportional valve so that the attachment trailer stops completely within a preset time.

[0014] The electromagnetic proportional valve is used to control the valve opening based on the acquired PWM current, and to control the time from when the spring chamber of the dual release valve parking brake system starts to release air until the wheel locks up.

[0015] Furthermore, the dual-release valve parking brake system includes an air pump, an air circuit triplet, a pressure switch, a ball valve, a brake chamber spring cavity, an air reservoir, and a dual-release valve parking brake manual control switch, with the air circuit connected in a conventional manner.

[0016] Furthermore, the positive terminal of the electromagnetic coil of the electromagnetic proportional valve is electrically connected to the PWM1 port of the vehicle controller, and the negative terminal is electrically connected to the vehicle ground.

[0017] Furthermore, the walking pressure sensor includes a left walking pressure sensor and a right walking pressure sensor, which are respectively installed on the left and right foot valves.

[0018] Furthermore, the signal lines of the left travel pressure sensor and the right travel pressure sensor are respectively connected to the analog input ports AIN1 and AIN2 of the vehicle controller.

[0019] Furthermore, the handbrake button is electrically connected to the switch input port DI1 of the vehicle controller.

[0020] Furthermore, the handbrake button is located on the travel control lever of the multi-functional excavator attachment trailer.

[0021] Furthermore, the vehicle controller is specifically used for,

[0022] The pre-configured parameters include the time from the start of deflation of the attachment trailer to its complete stop, the PWM current of the electromagnetic proportional valve, the total mass of the trailer and attachments, and the pressure value of the travel pressure sensor; the pressure value of the travel pressure sensor is the average value of the pressure signals collected by the left and right travel pressure sensors.

[0023] Get the total mass of the trailer and attachments in the current configuration;

[0024] Upon receiving the braking signal from the manual brake button, the system acquires the pressure signals collected by the left and right walking pressure sensors in real time, calculates the PWM current of the electromagnetic proportional valve based on the functional relationship, and sends it to the electromagnetic proportional valve.

[0025] Furthermore, the braking control system also includes instruments.

[0026] The instrument is equipped with a visual human-machine interface, which is used to select trailer attachments to obtain the total mass of the trailer and attachments, and then feeds it back to the vehicle controller.

[0027] Furthermore, the vehicle controller and the instrument cluster communicate via a CAN bus connection.

[0028] Furthermore, the instrument is also equipped with a parking countdown reminder function.

[0029] This invention also provides a braking control method for a braking control system of a multi-functional excavator attachment trailer, comprising:

[0030] The pre-configured time from the start of deflation to complete stop of the attachment trailer, the PWM current of the electromagnetic proportional valve, and the functional relationship between the total mass of the trailer and attachments and the pressure value of the walking pressure sensor are as follows:

[0031] Calculate the total mass of the trailer and its attachments based on the configuration of the trailer and its attachments;

[0032] When a braking signal is received, the pressure signals collected by the left and right walking pressure sensors are read, and the average value of the pressure signals is calculated as the pressure value of the walking pressure sensor.

[0033] Based on the aforementioned functional relationship, the PWM current of the electromagnetic proportional valve is calculated and sent to the electromagnetic proportional valve;

[0034] The opening degree of the electromagnetic proportional valve is controlled based on the PWM current, and the time from when the spring chamber of the dual release valve parking brake system starts to release air to when the wheel locks up is controlled.

[0035] After the preset time has elapsed, the control lever returns to the neutral position, causing the multi-functional excavator and the attachment trailer to stop synchronously.

[0036] Furthermore, the functional relationship between the pre-configured attachment trailer's time from the start of deflation to complete stop, the PWM current of the electromagnetic proportional valve, the total mass of the trailer and attachments, and the pressure value of the walking pressure sensor includes:

[0037] The preset time for the attachment trailer to come to a complete stop from the start of deflation is a constant t. Z The relation t is obtained. Z =t D +t H ,

[0038] Among them, t D The time from when the trailer spring chamber begins to deflate after the handbrake button is pressed until the wheels lock up, t H The coasting time after the wheels lock up;

[0039] t D It is a function of the PWM current i of the electromagnetic proportional valve, let t D =f D (i),

[0040] t H It is a function of the total mass m of the trailer and attachments and the initial speed v0 of the attachment trailer, and the initial speed v0 of the attachment trailer is positively correlated with the pressure value p0 of the travel pressure sensor. Let t H =f H (m,p0),

[0041] Obtain historical data for t Z =f D (i)+f H By fitting (m,p0), the functional relationships between the time from the start of deflation to complete stop of the attachment trailer, the PWM current of the electromagnetic proportional valve, the total mass of the trailer and attachments, and the pressure value of the walking pressure sensor are obtained.

[0042] The beneficial effects of this invention are as follows:

[0043] (1) The present invention retains the original air circuit system and manual braking function of the trailer, and adds an electromagnetic proportional valve to realize the synchronous braking of the excavator and the attachment trailer during driving through the vehicle controller. The modification cost is low and the structure is simple and easy to operate.

[0044] (2) This invention solves the problem that the attachment trailer cannot brake during driving, effectively avoids collision and folding accidents between the main and trailer when parking, and improves driving safety.

[0045] (3) With the braking control system designed in this invention, the operator can control the trailer brake from the cab, improving the convenience of operation. Attached Figure Description

[0046] Figure 1A general layout diagram of a multi-functional excavator attachment trailer and working attachments;

[0047] Figure 2 A schematic diagram of the braking control system of a multi-functional excavator attachment trailer provided by the present invention;

[0048] Figure 3 A flowchart of a braking control method for a multi-functional excavator attachment trailer provided by the present invention;

[0049] Figure 4 This is the operation interface for "attachment settings" in the touch screen instrument of this invention. Detailed Implementation

[0050] The present invention will now be further described. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0051] The overall layout of the multi-functional excavator's attached tow bar trailer and various work attachments is as follows: Figure 1 As shown, the vehicle can be equipped with various attachments such as excavator buckets, block grab buckets, pile drivers, rock drills, hydraulic shears, and milling heads to meet the basic needs of multi-tool operations in disaster relief and rescue. Regarding the reasonable requirements for the fixed positions of the attachments and their auxiliary equipment on the attachment trailer, based on the size and weight parameters of each attachment, the arrangement ensures that the center of gravity of the entire vehicle is close to the middle of the central axle when the attachment trailer is fully loaded.

[0052] Regarding the aforementioned multi-functional excavator with a tow bar attachment trailer, this invention provides a braking control system for the multi-functional excavator attachment trailer, such as... Figure 2 As shown, it includes:

[0053] 1. Air pump, 2. Air circuit triple unit, 3. Pressure switch, 4. Ball valve, 5. Brake air chamber spring cavity, 6. Air tank, 7. Double release valve, 8. Parking brake manual control switch, 9. Electromagnetic proportional valve, 10. Vehicle controller, 11. R1 left travel pressure sensor, 12. R2 right travel pressure sensor, 13. Hand brake button, 14. Instrument panel.

[0054] Specifically, the air pump 1, air circuit triplet 2, pressure switch 3, ball valve 4, brake air chamber spring cavity 5, air reservoir 6, and dual release valve parking brake manual control switch 7 are connected in the air circuit according to the existing technical solution (conventional method).

[0055] The compressed air generated by the air pump 1 first enters the air filter in the air circuit triplet 2. After purification, it enters the pressure reducing valve, and after pressure reduction, the gas pressure is controlled to meet the requirements of the pneumatic system. The output regulated gas enters the lubricating oil mist lubricator, where it atomizes the lubricating oil and mixes with the compressed air. Then, it flows into the air reservoir 6 through the pressure switch 3 and the ball valve 4 for storage. The compressed air in the air reservoir 6 enters the trailer brake air chamber spring cavity 5. The strong spring compression releases the wheel brakes. When parking or on a slope, the manual control switch 7 for the parking brake on the trailer's double release valve is pulled out, causing the pressure in the brake air chamber spring cavity 5 to drop below 0.4 MPa. The restoring force of the spring automatically activates the parking brake.

[0056] In this invention, the electromagnetic proportional valve 8 is connected in parallel to the air circuit of the original dual release valve. The positive terminal of the electromagnetic coil of the electromagnetic proportional valve 8 is electrically connected to the PWM1 port of the vehicle controller 9, and the negative terminal is electrically connected to the vehicle ground. When the trailer needs to stop during driving, the valve opening of the electromagnetic proportional valve 8 is adjusted by the vehicle controller.

[0057] The left travel pressure sensor 10 and the right travel pressure sensor 11 on the foot valve are electrically connected to the vehicle controller 9. Specifically, the signal lines of the left travel pressure sensor 10 and the right travel pressure sensor 11 are respectively connected to the analog input ports AIN1 and AIN2 of the vehicle controller 9.

[0058] The handbrake button 12 is electrically connected to the switch input port DI1 of the vehicle controller 9 and is used to send a braking signal to the vehicle controller 9. It should be noted that the handbrake button 12 can be located on the travel control lever for easy operation.

[0059] The vehicle controller 9 is used to collect the analog pressure signals from the left travel pressure sensor 10 and the right travel pressure sensor 11, receive the switching braking signal sent by the handbrake button 12 and the CAN signal sent by the instrument 13, and when the switching braking signal is received, calculate the PWM current of the electromagnetic proportional valve based on the functional relationship between the analog pressure signal, the total mass of the trailer and attachments and the PWM current of the electromagnetic proportional valve and send it to the electromagnetic proportional valve 8. The PWM current controls the opening of the electromagnetic proportional valve, controls the flow rate and speed of the air release in the air circuit system, and then controls the release time. Ultimately, it enables the multi-functional excavator and the attachment trailer to maintain consistent movements as much as possible during the driving process, avoiding accidents such as the attachment trailer colliding with the main vehicle or the main trailer collapsing.

[0060] Instrument 13 is equipped with a visual human-machine interface for selecting trailer attachments to obtain the total mass of the trailer and attachments, and then feeding back the information to the vehicle controller 9.

[0061] In this invention, the time from when the air supply to the trailer is cut off (the air begins to be released) to when it comes to a complete stop is a constant t. ZThis value is stored in the vehicle controller for constructing function relationships. It should be noted that this value can be modified via the instrument panel according to actual needs.

[0062] In this invention, the vehicle controller 9 and the instrument cluster 13 are connected and communicate via a CAN bus.

[0063] Preferably, the instrument cluster 13 is equipped with a parking countdown reminder function, thereby improving the operability of the system and the user experience.

[0064] Based on the above-described braking control system, another aspect of the present invention provides a braking control method for a multi-functional excavator trailer, see [link to relevant documentation]. Figure 3 The method includes:

[0065] S1. After calculation and on-site measurement correction, the function relating the electromagnetic proportional valve PWM current i, the total mass m of the trailer and attachments, and the pressure value p0 of the travel pressure sensor is obtained, and this function is read into the vehicle controller. The specific implementation process is as follows:

[0066] The preset time for the attachment trailer to come to a complete stop from the moment the air is deflated (start of deflation) is a constant t. Z The relation t is obtained. Z =t D +t H ,

[0067] Among them, t D The time from when the trailer spring chamber begins to deflate after the handbrake button is pressed until the wheels lock up, t H This refers to the coasting time after the wheels lock up.

[0068] t D It is a function of the PWM current i of the electromagnetic proportional valve, t H It is a function of the total mass m of the trailer and attachments and the initial speed v0 of the attachment trailer, and the initial speed v0 of the attachment trailer is positively correlated with the pressure value p0 of the travel pressure sensor; it should be noted that the pressure value p0 is the average value of the pressure signals collected by the left and right travel pressure sensors.

[0069] By acquiring a large amount of historical data and correcting it through calculations and on-site measurements, t can be obtained. Z =f D (i)+f H (m,p0),

[0070] This yields the matching relationship between the PWM current i of the electromagnetic proportional valve, the total mass m of the trailer and attachments, and the pressure value p0 of the walking pressure sensor.

[0071] S2. The mass of the trailer and each attachment is pre-written into the vehicle controller. The vehicle controller selects the vehicle attachments on the instrument interface and calculates the total mass m of the trailer and attachments.

[0072] For example, attachment icons can be set on the main interface of the instrument. After the operator clicks the icon, they can enter... Figure 4 The "Attachment Settings" interface shown allows you to select attachments.

[0073] S3. When you need to stop, press the handbrake button.

[0074] S4. Read the pressure value p0 from the walking pressure sensor through the vehicle controller.

[0075] S5. Calculate the PWM current i of the electromagnetic proportional valve according to the preset function in step S1 and send it to the electromagnetic proportional valve.

[0076] S6, after t Z When the time control travel lever returns to the neutral position, the multi-functional excavator and the attachment trailer stop simultaneously.

[0077] It should be noted that it can be set so that pressing the handbrake button displays "t" on the instrument panel. Z A countdown to 0, accompanied by a buzzer, reminds the operator to release the travel control lever.

[0078] The total mass of the attachments transported by the attachment trailer and the initial speed at the time of parking are different, and the time of coasting after the wheels lock up are different. This invention controls the opening of the electromagnetic proportional valve through the vehicle controller, and controls the time from the start of air release in the trailer spring chamber to the time of wheel lockup, so that the preset time from air cut-off to complete stop of the attachment trailer is consistent, and realizes synchronous parking of the multi-functional excavator and the attachment trailer.

[0079] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A braking control system for a multi-functional excavator attachment trailer, characterized in that, The system includes a dual-release valve parking brake system, as well as an electromagnetic proportional valve, vehicle controller, travel pressure sensor, and handbrake button. The electromagnetic proportional valve is connected in parallel to the air circuit of the dual release valve parking brake system. Both the walking pressure sensor and the handbrake button are electrically connected to the vehicle controller. The walking pressure sensor is installed on the foot valve and is used to detect walking pressure signals; The handbrake button is used to send a braking signal to the vehicle controller; The vehicle controller is used to obtain the total mass of the attachment trailer, collect the pressure analog signal from the walking pressure sensor, receive the switching braking signal sent by the handbrake button, and calculate the PWM current of the electromagnetic proportional valve and send it to the electromagnetic proportional valve so that the attachment trailer stops completely within a preset time. The vehicle controller is specifically used for: The pre-configured parameters include the time from the start of deflation of the attachment trailer to its complete stop, the PWM current of the electromagnetic proportional valve, the total mass of the trailer and attachments, and the pressure value of the travel pressure sensor; the pressure value of the travel pressure sensor is the average value of the pressure signals collected by the left and right travel pressure sensors. Get the total mass of the trailer and attachments in the current configuration; When the braking signal sent by the handbrake button is received, the pressure signal collected by the left and right walking pressure sensors is acquired in real time, and the electromagnetic proportional valve PWM current is calculated based on the function relationship and sent to the electromagnetic proportional valve. The electromagnetic proportional valve is used to control the valve opening based on the acquired PWM current, and to control the time from when the spring chamber of the dual release valve parking brake system starts to release air until the wheel locks up.

2. The braking control system for a multi-functional excavator attachment trailer according to claim 1, characterized in that, The dual-release valve parking brake system includes an air pump, an air circuit triplet, a pressure switch, a ball valve, a brake chamber spring cavity, an air reservoir, and a manual control switch for the dual-release valve parking brake.

3. The braking control system for a multi-functional excavator attachment trailer according to claim 1, characterized in that, The positive terminal of the electromagnetic coil of the electromagnetic proportional valve is electrically connected to the PWM1 port of the vehicle controller, and the negative terminal is connected to the vehicle ground.

4. The braking control system for a multi-functional excavator attachment trailer according to claim 1, characterized in that, The walking pressure sensor includes a left walking pressure sensor and a right walking pressure sensor, which are respectively installed on the left and right foot valves.

5. The braking control system for a multi-functional excavator attachment trailer according to claim 4, characterized in that, The signal lines of the left and right travel pressure sensors are respectively connected to the analog input ports AIN1 and AIN2 of the vehicle controller.

6. The braking control system for a multi-functional excavator attachment trailer according to claim 1, characterized in that, The handbrake button is electrically connected to the switch input port DI1 of the vehicle controller.

7. The braking control system for a multi-functional excavator attachment trailer according to claim 1, characterized in that, The handbrake button is located on the travel control lever of the multi-functional excavator attachment trailer.

8. The braking control system for a multi-functional excavator attachment trailer according to claim 1, characterized in that, The braking control system also includes instruments. The instrument is equipped with a visual human-machine interface, which is used to select trailer attachments to obtain the total mass of the trailer and attachments, and then feeds it back to the vehicle controller.

9. The braking control system for a multi-functional excavator attachment trailer according to claim 8, characterized in that, The vehicle controller and the instrument cluster communicate via a CAN bus.

10. The braking control system for a multi-functional excavator attachment trailer according to claim 8, characterized in that, The instrument panel is also equipped with a parking countdown reminder function.

11. A braking control method based on the braking control system of a multi-functional excavator attachment trailer according to any one of claims 1 to 10, characterized in that, include: The pre-configured time from the start of deflation to complete stop of the attachment trailer, the PWM current of the electromagnetic proportional valve, and the functional relationship between the total mass of the trailer and attachments and the pressure value of the walking pressure sensor are as follows: Calculate the total mass of the trailer and its attachments based on the configuration of the trailer and its attachments; When a braking signal is received, the pressure signals collected by the left and right walking pressure sensors are read, and the average value of the pressure signals is calculated as the pressure value of the walking pressure sensor. Based on the aforementioned functional relationship, the PWM current of the electromagnetic proportional valve is calculated and sent to the electromagnetic proportional valve; The opening degree of the electromagnetic proportional valve is controlled based on the PWM current, and the time from when the spring chamber of the dual release valve parking brake system starts to release air to when the wheel locks up is controlled. After the preset time has elapsed, the control lever returns to the neutral position, causing the multi-functional excavator and the attachment trailer to stop synchronously.

12. The braking control method according to claim 11, characterized in that, The functional relationship between the pre-configured attachment trailer's time from the start of deflation to complete stop, the PWM current of the electromagnetic proportional valve, the total mass of the trailer and attachments, and the pressure value of the walking pressure sensor includes: The preset time for the attachment trailer to come to a complete stop from the start of deflation is a constant. The relation is obtained as follows: , in, The time from when the trailer spring chamber begins to deflate after the handbrake button is pressed until the wheels lock up. The coasting time after the wheels lock up; It's about the PWM current of the electromagnetic proportional valve. The function, let , It concerns the total mass of the trailer and its attachments. Initial speed of attachment trailer The function, and the initial speed of the attachment trailer. Pressure value of walking pressure sensor Positive correlation, making , Obtain historical data, for By fitting the data, we obtained the functional relationship between the time it takes for the attachment trailer to stop completely after deflation, the PWM current of the electromagnetic proportional valve, the total mass of the trailer and attachments, and the pressure value of the walking pressure sensor.

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