Lifting axle control method with locking function

Abstract

The present invention relates to a lifting axle control method with a locking function. The method comprises the following steps: after the vehicle is powered on and in a stationary state or when the vehicle speed is less than V, the ECAS collects height information collected by the suspension height sensor, converts it into vehicle load information, and sends the vehicle load information to the vehicle control unit (VECU) via the CAN bus. The VECU compares the load information with the set light-load and heavy-load suspension height values ​​to independently determine the vehicle's current load condition. At this time, the lifting airbag circuit is connected, and the lifting inflation valve or lowering deflation valve is energized to inflate or deflate the lifting airbag, completing the lifting or lowering of the lifting axle. If the vehicle speed exceeds V, the VECU locks the logic of the ECAS lifting airbag and switch control, preventing the lifting or lowering of the lifting axle to maintain vehicle stability. The suspension height information from the ECAS is shared with the vehicle control unit (VECU), which uses the suspension height to determine the vehicle load condition, implements the vehicle automatic weighing function, and executes the automatic lifting and lowering of the lifting axle.

Description

Technical Field

[0001] The present invention relates to the field of chassis suspension control, and in particular to a lifting bridge control method with a locking function. Background Art

[0002] Lifting axles are a common feature on multi-axle heavy-duty commercial vehicles, allowing the driver to select between light and heavy loads. They often also feature adaptive steering, which can be locked and unlocked in forward gear but must be locked in reverse to prevent tire or axle collisions. The lifting / lowering and locking / unlocking functions are controlled by switches and status indicators in the cab, allowing the driver to select these functions.

[0003] Most lifting axles currently on the market use manual control, with the driver making judgments based on actual driving conditions. The controller receives control signals from the cab switches to adjust the vehicle's chassis height. This control method is greatly affected by the driver's subjective factors and cannot respond accurately and promptly to various working conditions. Summary of the Invention

[0004] To solve the above problems, the present invention provides a lifting axle control method with a locking function, which determines the vehicle load condition by the suspension height, realizes the vehicle automatic weighing function, and performs automatic lifting and lowering of the lifting axle.

[0005] The technical solution adopted by the present invention is: a lifting axle control method with a locking function, characterized by comprising the following steps: after the vehicle is powered on and in a stationary state or when the vehicle speed is less than V, the ECAS (Electronic-Controlled Air Suspension) system collects height information collected by the suspension height sensor, converts it into vehicle load information, and sends the vehicle load information to the vehicle controller (VECU) (Vehicle Electronic Control Unit) via the CAN bus. The VECU compares the load information with the set light load and heavy load suspension height values ​​to independently determine the current vehicle load condition; at this time, the lifting airbag circuit is connected, and the lifting inflation valve or the lowering deflation valve is energized to inflate or deflate the lifting airbag, completing the lifting or lowering of the lifting axle; if the vehicle speed exceeds V, the VECU locks the logic of the ECAS lifting airbag and switch control, thereby preventing the lifting or lowering of the lifting axle to maintain vehicle stability.

[0006] As a preferred option, the lifting axle gear control mode is: when engaging reverse gear, no matter what state the follow-up steering control switch is in, the vehicle controller VECU pin connected to the locking relay control end only outputs a low-level pulse to activate the locking inflation valve, complete the inflation, and lock the lifting axle lifting function; when exiting reverse gear, the vehicle controller VECU pin connected to the unlocking relay automatically outputs a low-level pulse to activate the unlocking exhaust valve, complete the exhaust, and unlock the lifting axle lifting function.

[0007] As a preference, the manual control mode of the lifting axle is activated when the gear is in neutral, and the vehicle controller VECU reads the status signal of the follow-up steering control switch in real time; the manual operation switch locks the gear, and the vehicle controller VECU reads the high-level signal of the switch lock, and then outputs a high-level pulse to the locking relay control end, activates the locking inflation valve, completes the inflation, and locks the lifting axle lifting function; the manual operation switch unlocks the gear, and the vehicle controller VECU reads the high-level signal of the switch unlock, and then outputs a high-level pulse to the unlocking relay control end, activates the unlocking exhaust valve, completes the exhaust, and unlocks the lifting axle lifting function.

[0008] Preferably, the lifting inflation valve, the lowering deflation valve, the locking inflation valve and the unlocking deflation valve are all two-position three-way solenoid valves, and the working medium is compressed air.

[0009] Preferably, the lifting inflation valve, the lowering deflation valve, the locking inflation valve and the unlocking exhaust valve are all controlled by high-level pulse signals with a duration of less than 30ms. They take action after receiving the electrical signal and maintain the state after the action.

[0010] Preferably, the two coils of the lifting inflation valve, the lowering deflation valve, the locking inflation valve and the unlocking exhaust valve are driven independently and do not work at the same time. The coils are driven by pulse signals and matched with non-self-locking self-resetting switches.

[0011] Preferably, an on-off air pressure alarm is installed on the lifting airbag to sense the inflation and deflation status of the airbag. The alarm is connected to the instrument cluster, and the instrument lights up the status indicator light corresponding to the airbag according to the level change.

[0012] Preferably, V is 15 km / h.

[0013] Preferably, the vehicle controller VECU reads the transmission gear status through the CAN bus and monitors two hard-wired signals of the follow-up steering control switch status; the vehicle controller VECU has two outputs to separately drive the follow-up unlocking relay and the follow-up locking relay control terminals.

[0014] The beneficial effects achieved by the present invention are as follows: suspension height information from the ECAS is shared with the vehicle control unit (VECU), and the vehicle load condition is determined by the suspension height, thereby realizing the vehicle automatic weighing function and executing the automatic raising and lowering of the lifting axle; a vehicle speed signal-enabled switch control circuit is designed, and a switch and relay adapted for triggering a solenoid valve with a high-level pulse are selected (a circuit consisting of a non-self-locking, non-self-resetting rocker switch and an electronic relay is selected to drive the solenoid valve); the logical relationship between the gear position and the switch-controlled follow-up steering unlocking and locking is identified, and a hardware circuit and driver are designed to enter the automatic gear control mode only in reverse gear and not interfere with switch control in non-reverse gear. The present invention has the following advantages:

[0015] 1. The vehicle is equipped with a built-in weighing function to identify the load condition and realize automatic raising and lowering of the lifting axle;

[0016] 2. The pneumatic actuator that realizes the lifting of the lifting axle and the follow-up steering lock has a memory function. It can keep the function activated after a short-term output of the electric drive, so as to avoid the electric drive unit being energized all the time.

[0017] 3. The follow-up steering function of the lifting axle in the lowered state when the vehicle is in reverse gear must be in the locked state, regardless of whether the driver manually presses the lock switch;

[0018] 4. The reverse gear has a higher priority than manual control. The vehicle will automatically lock when the reverse gear is engaged and automatically unlock when the reverse gear is finished, thus realizing the gear control follow-up steering mode.

[0019] 5. The vehicle does not enter the gear control follow-up steering mode when it is not in reverse gear, and the switch must be manually operated to lock or unlock;

[0020] 6. When the lifting axle is in the lifting or steering lock state, the instrument provides sound and light signals to remind the driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the lifting bridge lifting and steering locking control circuit of the present invention;

[0022] Figure 2 It is a schematic diagram of the solenoid valve structure;

[0023] Figure 3 Schematic diagram of switch positions;

[0024] Figure 4 This is a schematic diagram of the lifting bridge status indicator circuit;

[0025] In the figure: 1. VECU; 2. ECAS; 3. Lifting inflation valve; 4. Lowering deflation valve; 5. Lifting relay; 6. Lowering relay; 7. Lifting axle lifting control switch; 8. Locking inflation valve; 9. Unlocking exhaust valve; 10. Unlocking relay; 11. Locking relay; 12. Active steering control switch; 13. Instrument cluster; s1. Lifting axle lifting airbag pressure switch; s2. Lifting axle lowering airbag pressure switch; s3. Active steering locking airbag pressure switch; s4. Active steering unlocking airbag pressure switch; L1. Lifting axle lifting indicator light; L2. Lifting axle lowering indicator light; L3. Active steering locking indicator light; L4. Active steering unlocking indicator light. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] like Figure 1-4As shown, a lifting axle control method with a locking function of the present invention is as follows: after the vehicle is powered on, in a stationary state or when the vehicle speed is less than V, the ECAS (Electronic-controlled air suspension) collects height information collected by the suspension height sensor, converts it into vehicle load information, and sends the vehicle load information to the vehicle controller VECU (Vehicle Electronic Control Unit) via the CAN bus. The VECU compares the load information with the set light load and heavy load suspension height values ​​to independently determine the current load condition of the vehicle; at this time, the lifting airbag circuit is connected, and the lifting inflation valve 3 or the lowering deflation valve 4 is energized to inflate or deflate the lifting airbag, completing the lifting or lowering of the lifting axle; if the vehicle speed exceeds V, the VECU locks the logic of the ECAS lifting airbag and switch control, and the lifting or lowering of the lifting axle cannot be achieved at this time to maintain the stability of the vehicle.

[0030] In this embodiment, the lifting axle gear control mode is: when engaging reverse gear, no matter what state the follow-up steering control switch 12 is in, the vehicle controller VECU pin connected to the control end of the locking relay 11 only outputs a low-level pulse, activates the locking inflation valve 8, completes the inflation, and locks the lifting axle lifting function; when exiting reverse gear, the vehicle controller VECU pin connected to the unlocking relay 10 automatically outputs a low-level pulse, activates the unlocking exhaust valve 9, completes the exhaust, and unlocks the lifting axle lifting function.

[0031] In this embodiment, the manual control mode of the lifting axle is activated when the gear is in neutral, and the vehicle controller VECU reads the status signal of the follow-up steering control switch 12 in real time; the manual operation switch locks the gear, and the vehicle controller VECU reads the high-level signal of the switch lock and outputs a high-level pulse to the control end of the locking relay 11, activates the locking inflation valve 8, completes the inflation, and locks the lifting axle lifting function; the manual operation switch unlocks the gear, and the vehicle controller VECU reads the high-level signal of the switch unlock, and outputs a high-level pulse to the control end of the unlocking relay 10, activates the unlocking exhaust valve 9, completes the exhaust, and unlocks the lifting axle lifting function.

[0032] In this embodiment, the lifting inflation valve 3, the lowering deflation valve 4, the locking inflation valve 8 and the unlocking deflation valve 9 are all two-position three-way solenoid valves, and the working medium is compressed air.

[0033] In this embodiment, the lifting inflation valve 3, the lowering deflation valve 4, the locking inflation valve 8 and the unlocking exhaust valve 9 are all controlled by high-level pulse signals with a duration of less than 30ms. After receiving the electrical signal, they generate an action and maintain the state after the action.

[0034] In this embodiment, the two coils of the lifting inflation valve 3, the lowering deflation valve 4, the locking inflation valve 8 and the unlocking exhaust valve 9 are driven independently and do not work at the same time. The coils are driven by pulse signals and matched with non-self-locking self-resetting switches.

[0035] Combine Figure 4 As shown, in this embodiment, an on-off air pressure alarm is installed on the lifting airbag to sense the inflation and deflation status of the airbag. The alarm is connected to the instrument cluster 13, and the instrument cluster 13 lights up the status indicator light corresponding to the airbag according to the level change.

[0036] In this embodiment, a lifting bridge control method with a locking function includes the following steps:

[0037] After the vehicle is powered on and at rest or traveling at speeds below 15 km / h (calibratable), the ECAS collects height information from the suspension height sensor, converts it into vehicle load information, and transmits this load information to the vehicle control unit (VECU) via the CAN bus. The VECU compares the signal with the set light and heavy suspension height values ​​to determine the vehicle's current load and automatically raise or lower the lifting axle. At this point, the VECU connects the circuit controlled by the lifting axle lift control switch 7. Alternatively, the VECU can manually energize the lifting airbag's lift valve 3 or lowering valve 4 by operating a single-pole, double-throw, three-state switch, inflating or deflating the airbag and raising or lowering the lifting axle.

[0038] If the vehicle speed exceeds the calibrated value (15km / h), the EVCU will lock the logic of the ECAS automatic airbag lifting and lowering control switch 7. At this time, the airbag cannot be raised or lowered to maintain the stability of the vehicle.

[0039] Since the airbag only has two states, lifting and lowering, it is only necessary to install an on-off air pressure alarm on the airbag to sense the inflation and deflation state of the airbag. The alarm is connected to the instrument cluster 13. The instrument cluster 13 lights up the status indicator light corresponding to the airbag according to the level change.

[0040] The steering lock function is divided into gear control mode and manual control mode. The specific implementation methods are as follows:

[0041] Reverse gear has the highest priority. When reverse gear is engaged at any speed, regardless of the state of the follow-up steering control switch 12, the vehicle controller pin connected to the control end of the lock relay 11 only outputs a low-level pulse to activate the lock inflation valve 8 to complete inflation. When exiting reverse gear, the vehicle controller pin connected to the unlock relay 10 automatically outputs a low-level pulse to activate the unlock exhaust valve 9 to exhaust air. This is the gear control mode.

[0042] Manual control mode is only activated when the vehicle is in neutral gear, and the vehicle controller reads the status signal of the follow-up steering control switch 12 in real time. When the vehicle is in neutral gear (no speed limit), when the switch is manually operated to lock the gear, the vehicle controller reads the high-level signal of the switch lock and outputs a high-level pulse to the control terminal of the lock relay 11, activating the lock inflation valve 8 to complete inflation. When the switch is manually operated to unlock the gear, the vehicle controller reads the high-level signal of the switch unlock and outputs a high-level pulse to the control terminal of the unlock relay 10, activating the unlock exhaust valve 9 to complete exhaust - this is manual control mode.

[0043] The present invention has the following functions:

[0044] 1. Automatic weighing function

[0045] The air suspension control unit ECAS sends the collected suspension height sensor position signal to the vehicle controller VECU via the CAN bus. The VECU compares the signal with the set light-load and heavy-load suspension height values, independently determines the current load condition of the vehicle, and automatically raises and lowers the lifting axle.

[0046] 2. Solenoid valve with memory function (combined with Figure 2 shown)

[0047] The solenoid valve is a two-position, three-way structure, and its working medium is compressed air. It consists of an inflation solenoid valve and an exhaust solenoid valve. It is controlled by a high-level pulse signal with a duration of less than 30ms. The solenoid valve activates and maintains its activated state upon receiving the electrical signal.

[0048] 3. Selection of control switch (combined with Figure 3 shown)

[0049] The two coils of the solenoid valve are driven independently and will not work at the same time, so a three-state switch is selected with a single-pole double-throw contact structure; the coil is driven by a pulse signal, that is, inching control, and needs to be matched with a non-self-locking self-reset switch.

[0050] 4. Vehicle speed signal enables lifting and lowering circuit of lifting bridge

[0051] The lifting axle lifting control switch 7 is enabled only when the vehicle speed reaches the set value, otherwise it will not respond to the driver's switch operation; this solution uses relays (lifting relay 5 and lowering relay 6) in series to connect the lifting axle lifting and lowering switch circuit. The control ends of the two relays are driven by the high side of the same pin of the vehicle controller. When the vehicle speed is lower than the set value (which can be calibrated), a high-level pulse is output to enable the switch control circuit; when the vehicle speed is higher than the set value, the switch control circuit is cut off, making the switch invalid.

[0052] 5. Gear position and manual steering lock circuit

[0053] The vehicle controller reads the transmission gear status via the CAN bus and monitors two hard-wired signals for the status of the follow-up steering control switch 12. The vehicle controller has two outputs that independently drive the control terminals of the unlock relay 10 and the lock relay 11.

[0054] 6. Lifting and steering lock state sensing element of lifting axle (combined with Figure 4 shown)

[0055] The lifting / lowering and unlocking / locking airbags of the lifting axle use compressed air as the working medium. A pressure sensor or pressure switch can be used to sense the airbag pressure. Since it is only necessary to sense the pressure change after the airbag is inflated and deflated, and there is no need to continuously monitor the airbag pressure, a pressure switch is more appropriate and has advantages in terms of cost and technical difficulty. The normal air pressure value of the vehicle is greater than 8Mpa, and the time it takes for the airbag to inflate or deflate is less than 10 seconds. Consider using a normally open pressure switch with an alarm value of 7Mpa. The pressure switch signal is directly connected to the warning light pin of the instrument cluster. When it is open, the road light is off. When it is closed, the pin is grounded and the light is on.

[0056] The above illustrates and describes the basic principles and main structural features of the present invention. The present invention is not limited to the above examples. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

[0057] It should be noted that the description of the above technical solutions is illustrative only. This specification may be embodied in various forms and should not be construed as limiting the technical solutions set forth herein. Rather, these descriptions are provided to ensure that the disclosure of the present invention is thorough and complete and to fully convey the scope of the disclosure to those skilled in the art. Furthermore, the technical solutions of the present invention are limited only by the scope of the claims.

[0058] The shapes, sizes, ratios, angles, and numbers disclosed for describing various aspects of the present specification and claims are merely examples, and therefore, the present specification and claims are not limited to the details shown. In the following description, when a detailed description of a related known function or configuration is determined to be unnecessary to obscure the key points of the present specification and claims, the detailed description will be omitted.

[0059] When “including,” “having,” and “comprising” are used in this specification, unless otherwise used, there may also be another part or other parts, and the terms used may generally be singular but may also represent plural forms.

[0060] It should be noted that although the terms "first," "second," "top," "bottom," "one side," "the other side," "one end," "the other end," etc. may appear and be used in this specification to describe various components, these components and parts should not be limited by these terms. These terms are only used to distinguish one component or part from another. For example, without departing from the scope of this specification, a first component can be referred to as a second component, and similarly, a second component can be referred to as a first component. In certain circumstances, the components at the top and bottom can also be interchanged or switched with each other; the components at one end and the other end can have the same or different properties.

[0061] When describing positional relationships, for example, when the position sequence is described as "on," "above," "below," and "next," unless words or terms such as "just" or "directly" are used, situations where they are not in contact or in contact can also be included. If a first element is mentioned as being "on" a second element, it does not mean that the first element must be above the second element in the figure. The upper and lower parts of the components will change depending on the angle and orientation of observation. Therefore, in the drawings or in actual constructions, if it is mentioned that the first element is "on" a second element, it can include situations where the first element is "below" the second element as well as situations where the first element is "above" the second element. When describing temporal relationships, unless "just" or "directly" is used, situations where steps are not continuous can be included when describing "after," "subsequently," "followed," and "before." The features of the various embodiments of the present invention can be combined or spliced ​​with each other in part or in whole, and can be implemented in various different configurations as can be fully understood by those skilled in the art. The embodiments of the present invention can be implemented independently of each other, or can be implemented together in a mutually dependent relationship.

[0062] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and is susceptible to numerous variations. Any simple modifications, equivalent variations, and modifications to the above embodiments based on the technical essence of the present invention shall be deemed to fall within the scope of protection of the present invention.

Claims

1. A lifting axle control method with a locking function, characterized in that: The following steps are involved: After the vehicle is powered on, at rest or when traveling at a speed less than V, ECAS collects height information from the suspension height sensor, converts it into vehicle load information, and sends it to the vehicle controller (VECU) via the CAN bus. The VECU compares the load information with the set light-load and heavy-load suspension height values ​​to independently determine the vehicle's current load condition. At this time, the lift airbag circuit is connected, and the lift inflation valve or lowering deflation valve is energized to inflate or deflate the lift airbag, completing the lifting or lowering of the lifting axle. If the vehicle speed exceeds V, the VECU locks the ECAS lifting airbag and switch control logic, preventing the lifting axle from being raised or lowered to maintain vehicle stability. The manual control mode of the lifting axle is activated when the gear is in neutral. The vehicle controller VECU reads the status signal of the follow-up steering control switch in real time. When the switch is manually operated to lock the gear, the vehicle controller VECU reads the high-level signal of the switch lock and outputs a high-level pulse to the lock relay control end, activating the lock inflation valve to complete the inflation and lock the lifting axle lifting function. When the switch is manually operated to unlock the gear, the vehicle controller VECU reads the high-level signal of the switch unlock and outputs a high-level pulse to the unlock relay control end to activate the unlock exhaust valve to complete the exhaust and unlock the lifting axle lifting function. The lifting inflation valve, lowering deflation valve, locking inflation valve and unlocking deflation valve are all two-position three-way solenoid valves, and the working medium is compressed air; The two coils of the lifting inflation valve, lowering deflation valve, locking inflation valve and unlocking exhaust valve are driven independently and do not work at the same time. The coils are driven by pulse signals and matched with non-self-locking self-resetting switches.

2. The lifting axle control method with locking function according to claim 1, characterized in that: Lifting axle gear control mode: When engaging reverse gear, no matter what state the follow-up steering control switch is in, the vehicle controller VECU pin connected to the locking relay control end only outputs a low-level pulse to activate the locking inflation valve, complete the inflation, and lock the lifting axle lifting function; when exiting reverse gear, the vehicle controller VECU pin connected to the unlocking relay automatically outputs a low-level pulse to activate the unlocking exhaust valve, complete the exhaust, and unlock the lifting axle lifting function.

3. The lifting axle control method with locking function according to claim 1, characterized in that: The lifting inflation valve, lowering deflation valve, locking inflation valve and unlocking exhaust valve are all controlled by high-level pulse signals with a duration of less than 30ms. They will take action after receiving the electrical signal and maintain the state after the action.

4. The lifting axle control method with locking function according to claim 1, characterized in that: An on-off air pressure alarm is installed on the lifting airbag to sense the inflation and deflation status of the airbag. The alarm is connected to the instrument cluster, which lights up the status indicator light corresponding to the airbag according to the changes in the electrical level.

5. The lifting axle control method with locking function according to claim 1, characterized in that: V is 15km / h.

6. The lifting axle control method with locking function according to claim 1, characterized in that: The vehicle controller VECU reads the transmission gear status through the CAN bus and monitors two hard-wired signals of the follow-up steering control switch status; the vehicle controller VECU has two outputs to separately drive the follow-up unlocking relay and the follow-up locking relay control terminals.

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